Sources of Biased Inference in Alcohol and Drug Services Research: An Instrumental Variable Approach

PubMed Central

Schmidt, Laura A.; Tam, Tammy W.; Larson, Mary Jo

2012-01-01

Objective: This study examined the potential for biased inference due to endogeneity when using standard approaches for modeling the utilization of alcohol and drug treatment. Method: Results from standard regression analysis were compared with those that controlled for endogeneity using instrumental variables estimation. Comparable models predicted the likelihood of receiving alcohol treatment based on the widely used Aday and Andersen medical care–seeking model. Data were from the National Epidemiologic Survey on Alcohol and Related Conditions and included a representative sample of adults in households and group quarters throughout the contiguous United States. Results: Findings suggested that standard approaches for modeling treatment utilization are prone to bias because of uncontrolled reverse causation and omitted variables. Compared with instrumental variables estimation, standard regression analyses produced downwardly biased estimates of the impact of alcohol problem severity on the likelihood of receiving care. Conclusions: Standard approaches for modeling service utilization are prone to underestimating the true effects of problem severity on service use. Biased inference could lead to inaccurate policy recommendations, for example, by suggesting that people with milder forms of substance use disorder are more likely to receive care than is actually the case. PMID:22152672

Literature review of some selected types of results and statistical analyses of total-ozone data. [for the ozonosphere

NASA Technical Reports Server (NTRS)

Myers, R. H.

1976-01-01

The depletion of ozone in the stratosphere is examined, and causes for the depletion are cited. Ground station and satellite measurements of ozone, which are taken on a worldwide basis, are discussed. Instruments used in ozone measurement are discussed, such as the Dobson spectrophotometer, which is credited with providing the longest and most extensive series of observations for ground based observation of stratospheric ozone. Other ground based instruments used to measure ozone are also discussed. The statistical differences of ground based measurements of ozone from these different instruments are compared to each other, and to satellite measurements. Mathematical methods (i.e., trend analysis or linear regression analysis) of analyzing the variability of ozone concentration with respect to time and lattitude are described. Various time series models which can be employed in accounting for ozone concentration variability are examined.

Cross-cultural validation of instruments measuring health beliefs about colorectal cancer screening among Korean Americans.

PubMed

Lee, Shin-Young; Lee, Eunice E

2015-02-01

The purpose of this study was to report the instrument modification and validation processes to make existing health belief model scales culturally appropriate for Korean Americans (KAs) regarding colorectal cancer (CRC) screening utilization. Instrument translation, individual interviews using cognitive interviewing, and expert reviews were conducted during the instrument modification phase, and a pilot test and a cross-sectional survey were conducted during the instrument validation phase. Data analyses of the cross-sectional survey included internal consistency and construct validity using exploratory and confirmatory factor analysis. The main issues identified during the instrument modification phase were (a) cultural and linguistic translation issues and (b) newly developed items reflecting Korean cultural barriers. Cross-sectional survey analyses during the instrument validation phase revealed that all scales demonstrate good internal consistency reliability (Cronbach's alpha=.72~.88). Exploratory factor analysis showed that susceptibility and severity loaded on the same factor, which may indicate a threat variable. Items with low factor loadings in the confirmatory factor analysis may relate to (a) lack of knowledge about fecal occult blood testing and (b) multiple dimensions of the subscales. Methodological, sequential processes of instrument modification and validation, including translation, individual interviews, expert reviews, pilot testing and a cross-sectional survey, were provided in this study. The findings indicate that existing instruments need to be examined for CRC screening research involving KAs.

Utility-Based Instruments for People with Dementia: A Systematic Review and Meta-Regression Analysis.

PubMed

Li, Li; Nguyen, Kim-Huong; Comans, Tracy; Scuffham, Paul

2018-04-01

Several utility-based instruments have been applied in cost-utility analysis to assess health state values for people with dementia. Nevertheless, concerns and uncertainty regarding their performance for people with dementia have been raised. To assess the performance of available utility-based instruments for people with dementia by comparing their psychometric properties and to explore factors that cause variations in the reported health state values generated from those instruments by conducting meta-regression analyses. A literature search was conducted and psychometric properties were synthesized to demonstrate the overall performance of each instrument. When available, health state values and variables such as the type of instrument and cognitive impairment levels were extracted from each article. A meta-regression analysis was undertaken and available covariates were included in the models. A total of 64 studies providing preference-based values were identified and included. The EuroQol five-dimension questionnaire demonstrated the best combination of feasibility, reliability, and validity. Meta-regression analyses suggested that significant differences exist between instruments, type of respondents, and mode of administration and the variations in estimated utility values had influences on incremental quality-adjusted life-year calculation. This review finds that the EuroQol five-dimension questionnaire is the most valid utility-based instrument for people with dementia, but should be replaced by others under certain circumstances. Although no utility estimates were reported in the article, the meta-regression analyses that examined variations in utility estimates produced by different instruments impact on cost-utility analysis, potentially altering the decision-making process in some circumstances. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Performance evaluation of the microINR® point-of-care INR-testing system.

PubMed

Joubert, J; van Zyl, M C; Raubenheimer, J

2018-04-01

Point-of-care International Normalised Ratio (INR) testing is used frequently. We evaluated the microINR ® POC system for accuracy, precision and measurement repeatability, and investigated instrument and test chip variability and error rates. Venous blood INRs of 210 patients on warfarin were obtained with Thromborel ® S on the Sysmex CS-2100i ® analyser and compared with capillary blood microINR ® values. Precision was assessed using control materials. Measurement repeatability was calculated on 51 duplicate finger-prick INRs. Triplicate finger-prick INRs using three different instruments (30 patients) and three different test chip lots (29 patients) were used to evaluate instrument and test chip variability. Linear regression analysis of microINR ® and Sysmex CS2100i ® values showed a correlation coefficient of 0.96 (P < .0001) and a positive proportional bias of 4.4%. Dosage concordance was 93.8% and clinical agreement 95.7%. All acceptance criteria based on ISO standard 17593:2007 system accuracy requirements were met. Control material coefficients of variation (CV) varied from 6.2% to 16.7%. The capillary blood measurement repeatability CV was 7.5%. No significant instrument (P = .93) or test chip (P = .81) variability was found, and the error rate was low (2.8%). The microINR ® instrument is accurate and precise for monitoring warfarin therapy. © 2017 John Wiley & Sons Ltd.

Satisfaction and adherence in patients with iron overload receiving iron chelation therapy as assessed by a newly developed patient instrument.

PubMed

Rofail, Diana; Abetz, Linda; Viala, Muriel; Gait, Claire; Baladi, Jean-Francois; Payne, Krista

2009-01-01

This study assesses satisfaction with iron chelation therapy (ICT) based on a reliable and valid instrument, and explores the relationship between satisfaction and adherence to ICT. Patients in the USA and UK completed a new "Satisfaction with ICT" (SICT) instrument consisting of 28 items, three pertaining to adherence. Simple and multivariate regression analyses assessed the relationship between satisfaction with different aspects of ICT and adherence. First assessments of the SICT instrument indicate its validity and reliability. Recommended thresholds for internal consistency, convergent validity, discriminant validity, and floor and ceiling effects were met. A number of variables were identified in the simple linear regression analyses as significant predictors of "never thinking about stopping ICT," a proxy for adherence. These significant variables were entered into the multivariate model to assess the combined factor effects, explaining 42% of the total variance of "never thinking about stopping ICT." A significant and positive relationship was demonstrated between "never thinking about stopping ICT" and age (P = 0.04), Perceived Effectiveness of ICT (P = 0.003), low Burden of ICT (P = 0.002), and low Side Effects of ICT (P = 0.01). The SICT is a reliable and valid instrument which will be useful in ICT clinical trials. Furthermore, the administration of ICT by slow subcutaneous infusion negatively impacts on satisfaction with ICT which was shown to be a determinant of adherence. This points to the need for new more convenient and less burdensome oral iron chelators to increase adherence, and ultimately to improve patient outcomes.

Sources of Variability in Chlorophyll Analysis by Fluorometry and by High Performance Liquid Chromatography. Chapter 22

NASA Technical Reports Server (NTRS)

VanHeukelem, Laurie; Thomas, Crystal S.; Glibert, Patricia M.

2001-01-01

The need for accurate determination of chlorophyll a (chl a) is of interest for numerous reasons. From the need for ground-truth data for remote sensing to pigment detection for laboratory experimentation, it is essential to know the accuracy of the analyses and the factors potentially contributing to variability and error. Numerous methods and instrument techniques are currently employed in the analyses of chl a. These methods range from spectrophotometric quantification, to fluorometric analysis and determination by high performance liquid chromatography. Even within the application of HPLC techniques, methods vary. Here we provide the results of a comparison among methods and provide some guidance for improving the accuracy of these analyses. These results are based on a round-robin conducted among numerous investigators, including several in the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) and HyCODE Programs. Our purpose here is not to present the full results of the laboratory intercalibration; those results will be presented elsewhere. Rather, here we highlight some of the major factors that may contribute to the variability observed. Specifically, we aim to assess the comparability of chl a analyses performed by fluorometry and HPLC, and we identify several factors in the analyses which may contribute disproportionately to this variability.

The impact of sub-skills and item content on students' skills with regard to the control-of-variables strategy

NASA Astrophysics Data System (ADS)

Schwichow, Martin; Christoph, Simon; Boone, William J.; Härtig, Hendrik

2016-01-01

The so-called control-of-variables strategy (CVS) incorporates the important scientific reasoning skills of designing controlled experiments and interpreting experimental outcomes. As CVS is a prominent component of science standards appropriate assessment instruments are required to measure these scientific reasoning skills and to evaluate the impact of instruction on CVS development. A detailed review of existing CVS instruments suggests that they utilize different, and only a few of the four, critical CVS sub-skills in the item development. This study presents a new CVS assessment instrument (CVS Inventory, CVSI) and investigates the validity of student measures derived from this instrument utilizing Rasch analyses. The results indicate that the CVSI produces reliable and valid student measures with regard to CVS. Furthermore, the results show that the item difficulty depends on the CVS sub-skills utilized in item development, but not on the item content. Accordingly, previous instruments that are restricted to a few CVS sub-skills tend to over- or underestimate students' CVS skills. In addition, these results indicate that students are able to use CVS as a domain general strategy in multiple content areas. Consequences for science instruction and assessment are discussed.

How adolescents construct their future: the effect of loneliness on future orientation.

PubMed

Seginer, Rachel; Lilach, Efrat

2004-12-01

This study examined the effect of loneliness, gender, and two dimensions of prospective life domains on adolescent future orientation. Future orientation was studied in four prospective domains: social relations, marriage and family, higher education and work and career. These domains are described in terms of two dimensions: theme (relational vs. instrumental) and distance (near vs. distant future). Data collected from Israeli Jewish adolescents (11th graders) were analysed by repeated measures ANOVAs and ANCOVAs (covariate: depressive experiences) for seven future orientation variables: value, expectance, control (motivational variables), hopes, fears (cognitive representation variables), exploration, commitment (behavioural variables). As predicted, lonely adolescents scored lower than socially embedded adolescents on future orientation variables applied to the relational and near future domains and lonely boys scored lower than lonely girls. However, effects were found only on the three future orientation motivational variables and not on the cognitive representation and behavioural variables. Contrary to prediction controlling for the effect of depressive experiences did not reduce the effect of loneliness on the future orientation variables, but reduced the tendency of adolescents to score higher on all future orientation variables in the instrumental than in the relational prospective domains. The contribution of these findings to the understanding of adolescent loneliness and future orientation was discussed and directions for future research were suggested.

Information content of MOPITT CO profile retrievals: Temporal and geographical variability

NASA Astrophysics Data System (ADS)

Deeter, M. N.; Edwards, D. P.; Gille, J. C.; Worden, H. M.

2015-12-01

Satellite measurements of tropospheric carbon monoxide (CO) enable a wide array of applications including studies of air quality and pollution transport. The MOPITT (Measurements of Pollution in the Troposphere) instrument on the Earth Observing System Terra platform has been measuring CO concentrations globally since March 2000. As indicated by the Degrees of Freedom for Signal (DFS), the standard metric for trace-gas retrieval information content, MOPITT retrieval performance varies over a wide range. We show that both instrumental and geophysical effects yield significant geographical and temporal variability in MOPITT DFS values. Instrumental radiance uncertainties, which describe random errors (or "noise") in the calibrated radiances, vary over long time scales (e.g., months to years) and vary between the four detector elements of MOPITT's linear detector array. MOPITT retrieval performance depends on several factors including thermal contrast, fine-scale variability of surface properties, and CO loading. The relative importance of these various effects is highly variable, as demonstrated by analyses of monthly mean DFS values for the United States and the Amazon Basin. An understanding of the geographical and temporal variability of MOPITT retrieval performance is potentially valuable to data users seeking to limit the influence of the a priori through data filtering. To illustrate, it is demonstrated that calculated regional-average CO mixing ratios may be improved by excluding observations from a subset of pixels in MOPITT's linear detector array.

Internalized HIV Stigma and Disclosure Concerns: Development and Validation of Two Scales in Spanish-Speaking Populations.

PubMed

Hernansaiz-Garrido, Helena; Alonso-Tapia, Jesús

2017-01-01

Internalized stigma and disclosure concerns are key elements for the study of mental health in people living with HIV. Since no measures of these constructs were available for Spanish population, this study sought to develop such instruments, to analyze their reliability and validity and to provide a short version. A heterogeneous sample of 458 adults from different Spanish-speaking countries completed the HIV-Internalized Stigma Scale and the HIV-Disclosure Concerns Scale, along with the Hospital Anxiety and Depression Scale, Rosenberg's Self-esteem Scale and other socio-demographic variables. Reliability and correlation analyses, exploratory factor analyses, path analyses with latent variables, and ANOVAs were conducted to test the scales' psychometric properties. The scales showed good reliability in terms of internal consistency and temporal stability, as well as good sensitivity and factorial and criterion validity. The HIV-Internalized Stigma Scale and the HIV-Disclosure Concerns Scale are reliable and valid means to assess these variables in several contexts.

The Use of Linear Instrumental Variables Methods in Health Services Research and Health Economics: A Cautionary Note

PubMed Central

Terza, Joseph V; Bradford, W David; Dismuke, Clara E

2008-01-01

Objective To investigate potential bias in the use of the conventional linear instrumental variables (IV) method for the estimation of causal effects in inherently nonlinear regression settings. Data Sources Smoking Supplement to the 1979 National Health Interview Survey, National Longitudinal Alcohol Epidemiologic Survey, and simulated data. Study Design Potential bias from the use of the linear IV method in nonlinear models is assessed via simulation studies and real world data analyses in two commonly encountered regression setting: (1) models with a nonnegative outcome (e.g., a count) and a continuous endogenous regressor; and (2) models with a binary outcome and a binary endogenous regressor. Principle Findings The simulation analyses show that substantial bias in the estimation of causal effects can result from applying the conventional IV method in inherently nonlinear regression settings. Moreover, the bias is not attenuated as the sample size increases. This point is further illustrated in the survey data analyses in which IV-based estimates of the relevant causal effects diverge substantially from those obtained with appropriate nonlinear estimation methods. Conclusions We offer this research as a cautionary note to those who would opt for the use of linear specifications in inherently nonlinear settings involving endogeneity. PMID:18546544

Evidence for a possible modern and mid-Holocene solar influence on climate from Lake Titicaca, South America

NASA Astrophysics Data System (ADS)

Theissen, K. M.; Dunbar, R. B.

2005-12-01

In tropical regions, there are few paleoclimate archives with the necessary resolution to investigate climate variability at interannual-to-decadal timescales prior to the onset of the instrumental record. Interannual variability associated with the El Niño Southern Oscillation (ENSO) is well documented in the instrumental record and the importance of the precessional forcing of millennial variability has been established in studies of tropical paleoclimate records. In contrast, decade-to-century variability is still poorly understood. Here, we examine interannual to decadal variability in the northern Altiplano of South America using digital image analysis of a floating interval of varved sediments of middle Holocene age (~6160-6310 yr BP) from Lake Titicaca. Multi-taper method (MTM) and wavelet frequency-domain analyses were performed on a time series generated from a gray-scaled digital image of the mm-thick laminations. Our results indicate significant power at a decadal periodicity (10-12 years) associated with the Schwabe cycle of solar activity. Frequency-domain analysis also indicates power at 2-2.5 year periodicities associated with ENSO. Similarly, spectral analysis of a 75 year instrumental record of Titicaca lake level shows significant power at both solar and ENSO periodicities. Although both of the examined records are short, our results imply that during both the mid-Holocene and modern times, solar and ENSO variability may have contributed to high frequency climate fluctuations over the northern Altiplano. We suspect that solar influence on large-scale atmospheric circulation features may account for the decadal variability in the mid-Holocene and present-day water balance of the Altiplano.

Comparing surgical trays with redundant instruments with trays with reduced instruments: a cost analysis

PubMed Central

John-Baptiste, A.; Sowerby, L.J.; Chin, C.J.; Martin, J.; Rotenberg, B.W.

2016-01-01

Background: When prearranged standard surgical trays contain instruments that are repeatedly unused, the redundancy can result in unnecessary health care costs. Our objective was to estimate potential savings by performing an economic evaluation comparing the cost of surgical trays with redundant instruments with surgical trays with reduced instruments ("reduced trays"). Methods: We performed a cost-analysis from the hospital perspective over a 1-year period. Using a mathematical model, we compared the direct costs of trays containing redundant instruments to reduced trays for 5 otolaryngology procedures. We incorporated data from several sources including local hospital data on surgical volume, the number of instruments on redundant and reduced trays, wages of personnel and time required to pack instruments. From the literature, we incorporated instrument depreciation costs and the time required to decontaminate an instrument. We performed 1-way sensitivity analyses on all variables, including surgical volume. Costs were estimated in 2013 Canadian dollars. Results: The cost of redundant trays was $21 806 and the cost of reduced trays was $8803, for a 1-year cost saving of $13 003. In sensitivity analyses, cost savings ranged from $3262 to $21 395, based on the surgical volume at the institution. Variation in surgical volume resulted in a wider range of estimates, with a minimum of $3253 for low-volume to a maximum of $52 012 for high-volume institutions. Interpretation: Our study suggests moderate savings may be achieved by reducing surgical tray redundancy and, if applied to other surgical specialties, may result in savings to Canadian health care systems. PMID:27975045

Comparing surgical trays with redundant instruments with trays with reduced instruments: a cost analysis.

PubMed

John-Baptiste, A; Sowerby, L J; Chin, C J; Martin, J; Rotenberg, B W

2016-01-01

When prearranged standard surgical trays contain instruments that are repeatedly unused, the redundancy can result in unnecessary health care costs. Our objective was to estimate potential savings by performing an economic evaluation comparing the cost of surgical trays with redundant instruments with surgical trays with reduced instruments ("reduced trays"). We performed a cost-analysis from the hospital perspective over a 1-year period. Using a mathematical model, we compared the direct costs of trays containing redundant instruments to reduced trays for 5 otolaryngology procedures. We incorporated data from several sources including local hospital data on surgical volume, the number of instruments on redundant and reduced trays, wages of personnel and time required to pack instruments. From the literature, we incorporated instrument depreciation costs and the time required to decontaminate an instrument. We performed 1-way sensitivity analyses on all variables, including surgical volume. Costs were estimated in 2013 Canadian dollars. The cost of redundant trays was $21 806 and the cost of reduced trays was $8803, for a 1-year cost saving of $13 003. In sensitivity analyses, cost savings ranged from $3262 to $21 395, based on the surgical volume at the institution. Variation in surgical volume resulted in a wider range of estimates, with a minimum of $3253 for low-volume to a maximum of $52 012 for high-volume institutions. Our study suggests moderate savings may be achieved by reducing surgical tray redundancy and, if applied to other surgical specialties, may result in savings to Canadian health care systems.

Information-theoretic approach to lead-lag effect on financial markets

NASA Astrophysics Data System (ADS)

Fiedor, Paweł

2014-08-01

Recently the interest of researchers has shifted from the analysis of synchronous relationships of financial instruments to the analysis of more meaningful asynchronous relationships. Both types of analysis are concentrated mostly on Pearson's correlation coefficient and consequently intraday lead-lag relationships (where one of the variables in a pair is time-lagged) are also associated with them. Under the Efficient-Market Hypothesis such relationships are not possible as all information is embedded in the prices, but in real markets we find such dependencies. In this paper we analyse lead-lag relationships of financial instruments and extend known methodology by using mutual information instead of Pearson's correlation coefficient. Mutual information is not only a more general measure, sensitive to non-linear dependencies, but also can lead to a simpler procedure of statistical validation of links between financial instruments. We analyse lagged relationships using New York Stock Exchange 100 data not only on an intraday level, but also for daily stock returns, which have usually been ignored.

Instrumental variable applications using nursing home prescribing preferences in comparative effectiveness research.

PubMed

Huybrechts, Krista F; Gerhard, Tobias; Franklin, Jessica M; Levin, Raisa; Crystal, Stephen; Schneeweiss, Sebastian

2014-08-01

Nursing home residents are of particular interest for comparative effectiveness research given their susceptibility to adverse treatment effects and systematic exclusion from trials. However, the risk of residual confounding because of unmeasured markers of declining health using conventional analytic methods is high. We evaluated the validity of instrumental variable (IV) methods based on nursing home prescribing preference to mitigate such confounding, using psychotropic medications to manage behavioral problems in dementia as a case study. A cohort using linked data from Medicaid, Medicare, Minimum Data Set, and Online Survey, Certification and Reporting for 2001-2004 was established. Dual-eligible patients ≥65 years who initiated psychotropic medication use after admission were selected. Nursing home prescribing preference was characterized using mixed-effects logistic regression models. The plausibility of IV assumptions was explored, and the association between psychotropic medication class and 180-day mortality was estimated. High-prescribing and low-prescribing nursing homes differed by a factor of 2. Each preference-based IV measure described a substantial proportion of variation in psychotropic medication choice (β(IV → treatment): 0.22-0.36). Measured patient characteristics were well balanced across patient groups based on instrument status (52% average reduction in Mahalanobis distance). There was no evidence that instrument status was associated with markers of nursing home quality of care. Findings indicate that IV analyses using nursing home prescribing preference may be a useful approach in comparative effectiveness studies, and should extend naturally to analyses including untreated comparison groups, which are of great scientific interest but subject to even stronger confounding. Copyright © 2014 John Wiley & Sons, Ltd.

Spatio-Temporal Variability of Water Vapor in the Free Troposphere Investigated by Dial and Ftir Vertical Soundings

NASA Astrophysics Data System (ADS)

Vogelmann, H.; Sussmann, R.; Trickl, T.; Reichert, A.

2016-06-01

We report on the free tropospheric spatio-temporal variability of water vapor investigated by the analysis of a five-year period of water vapor vertical soundings above Mt. Zugspitze (2962 m a.s.l., Germany). Our results are obtained from a combination of measurements of vertically integrated water vapor (IWV), recorded with a solar Fourier Transform InfraRed (FTIR) spectrometer and of water vapor profiles recorded with the nearby differential absorption lidar (DIAL). The special geometrical arrangement of one zenith-viewing and one sun-pointing instrument and the temporal resolution of both optical instruments allow for an investigation of the spatio-temporal variability of IWV on a spatial scale of less than one kilometer and on a time scale of less than one hour. We investigated the short-term variability of both IWV and water vapor profiles from statistical analyses. The latter was also examined by case studies with a clear assignment to certain atmospheric processes as local convection or long-range transport. This study is described in great detail in our recent publication [1].

Incorporating variability in point estimates in risk assessment: bridging the gap between LC50 and population endpoints

USDA-ARS?s Scientific Manuscript database

Historically, the use of point estimates such as the LC50 has been instrumental in assessing the risk associated with toxicants to rare or economically important species. In recent years, growing awareness of the shortcomings of this approach has led to an increased focus on analyses using populatio...

A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for the Surface of Mars: An Instrument for the Planetary Science Community

NASA Technical Reports Server (NTRS)

Edmunson, J.; Gaskin, J. A.; Danilatos, G.; Doloboff, I. J.; Effinger, M. R.; Harvey, R. P.; Jerman, G. A.; Klein-Schoder, R.; Mackie, W.; Magera, B.;

Genetic evidence of a causal effect of insulin resistance on branched-chain amino acid levels.

PubMed

Mahendran, Yuvaraj; Jonsson, Anna; Have, Christian T; Allin, Kristine H; Witte, Daniel R; Jørgensen, Marit E; Grarup, Niels; Pedersen, Oluf; Kilpeläinen, Tuomas O; Hansen, Torben

2017-05-01

Fasting plasma levels of branched-chain amino acids (BCAAs) are associated with insulin resistance, but it remains unclear whether there is a causal relation between the two. We aimed to disentangle the causal relations by performing a Mendelian randomisation study using genetic variants associated with circulating BCAA levels and insulin resistance as instrumental variables. We measured circulating BCAA levels in blood plasma by NMR spectroscopy in 1,321 individuals from the ADDITION-PRO cohort. We complemented our analyses by using previously published genome-wide association study (GWAS) results from the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) (n = 46,186) and from a GWAS of serum BCAA levels (n = 24,925). We used a genetic risk score (GRS), calculated using ten established fasting serum insulin associated variants, as an instrumental variable for insulin resistance. A GRS of three variants increasing circulating BCAA levels was used as an instrumental variable for circulating BCAA levels. Fasting plasma BCAA levels were associated with higher HOMA-IR in ADDITION-PRO (β 0.137 [95% CI 0.08, 0.19] p = 6 × 10 -7 ). However, the GRS for circulating BCAA levels was not associated with fasting insulin levels or HOMA-IR in ADDITION-PRO (β -0.011 [95% CI -0.053, 0.032] p = 0.6 and β -0.011 [95% CI -0.054, 0.031] p = 0.6, respectively) or in GWAS results for HOMA-IR from MAGIC (β for valine-increasing GRS -0.012 [95% CI -0.069, 0.045] p = 0.7). By contrast, the insulin-resistance-increasing GRS was significantly associated with increased BCAA levels in ADDITION-PRO (β 0.027 [95% CI 0.005, 0.048] p = 0.01) and in GWAS results for serum BCAA levels (β 1.22 [95% CI 0.71, 1.73] p = 4 × 10 -6 , β 0.96 [95% CI 0.45, 1.47] p = 3 × 10 -4 , and β 0.67 [95% CI 0.16, 1.18] p = 0.01 for isoleucine, leucine and valine levels, respectively) and instrumental variable analyses in ADDITION-PRO indicated that HOMA-IR is causally related to higher circulating fasting BCAA levels (β 0.73 [95% CI 0.26, 1.19] p = 0.002). Our results suggest that higher BCAA levels do not have a causal effect on insulin resistance while increased insulin resistance drives higher circulating fasting BCAA levels.

Selection of key ambient particulate variables for epidemiological studies - applying cluster and heatmap analyses as tools for data reduction.

PubMed

Gu, Jianwei; Pitz, Mike; Breitner, Susanne; Birmili, Wolfram; von Klot, Stephanie; Schneider, Alexandra; Soentgen, Jens; Reller, Armin; Peters, Annette; Cyrys, Josef

2012-10-01

The success of epidemiological studies depends on the use of appropriate exposure variables. The purpose of this study is to extract a relatively small selection of variables characterizing ambient particulate matter from a large measurement data set. The original data set comprised a total of 96 particulate matter variables that have been continuously measured since 2004 at an urban background aerosol monitoring site in the city of Augsburg, Germany. Many of the original variables were derived from measured particle size distribution (PSD) across the particle diameter range 3 nm to 10 μm, including size-segregated particle number concentration, particle length concentration, particle surface concentration and particle mass concentration. The data set was complemented by integral aerosol variables. These variables were measured by independent instruments, including black carbon, sulfate, particle active surface concentration and particle length concentration. It is obvious that such a large number of measured variables cannot be used in health effect analyses simultaneously. The aim of this study is a pre-screening and a selection of the key variables that will be used as input in forthcoming epidemiological studies. In this study, we present two methods of parameter selection and apply them to data from a two-year period from 2007 to 2008. We used the agglomerative hierarchical cluster method to find groups of similar variables. In total, we selected 15 key variables from 9 clusters which are recommended for epidemiological analyses. We also applied a two-dimensional visualization technique called "heatmap" analysis to the Spearman correlation matrix. 12 key variables were selected using this method. Moreover, the positive matrix factorization (PMF) method was applied to the PSD data to characterize the possible particle sources. Correlations between the variables and PMF factors were used to interpret the meaning of the cluster and the heatmap analyses. Copyright © 2012 Elsevier B.V. All rights reserved.

Instrumental variable specifications and assumptions for longitudinal analysis of mental health cost offsets.

PubMed

O'Malley, A James

2012-12-01

Instrumental variables (IVs) enable causal estimates in observational studies to be obtained in the presence of unmeasured confounders. In practice, a diverse range of models and IV specifications can be brought to bear on a problem, particularly with longitudinal data where treatment effects can be estimated for various functions of current and past treatment. However, in practice the empirical consequences of different assumptions are seldom examined, despite the fact that IV analyses make strong assumptions that cannot be conclusively tested by the data. In this paper, we consider several longitudinal models and specifications of IVs. Methods are applied to data from a 7-year study of mental health costs of atypical and conventional antipsychotics whose purpose was to evaluate whether the newer and more expensive atypical antipsychotic medications lead to a reduction in overall mental health costs.

Musicians, postural quality and musculoskeletal health: A literature's review.

PubMed

Blanco-Piñeiro, Patricia; Díaz-Pereira, M Pino; Martínez, Aurora

2017-01-01

An analysis of the salient characteristics of research papers published between 1989 and 2015 that evaluate the relationship between postural quality during musical performance and various performance quality and health factors, with emphasis on musculoskeletal health variables. Searches of Medline, Scopus and Google Scholar for papers that analysed the subject of the study objective. The following MeSH descriptors were used: posture; postural balance; muscle, skeletal; task performance and analysis; back; and spine and music. A descriptive statistical analysis of their methodology (sample types, temporal design, and postural, health and other variables analysed) and findings has been made. The inclusion criterion was that the body postural quality of the musicians during performance was included among the target study variables. Forty-one relevant empirical studies were found, written in English. Comparison and analysis of their results was hampered by great disparities in measuring instruments and operationalization of variables. Despite the growing interest in the relationships among these variables, the empirical knowledge base still has many limitations, making rigorous comparative analysis difficult. Copyright © 2016 Elsevier Ltd. All rights reserved.

Refining the tobacco dependence phenotype using the Wisconsin Inventory of Smoking Dependence Motives (WISDM)

PubMed Central

Piper, Megan E.; Bolt, Daniel M.; Kim, Su-Young; Japuntich, Sandra J.; Smith, Stevens S.; Niederdeppe, Jeff; Cannon, Dale S.; Baker, Timothy B.

2008-01-01

The construct of tobacco dependence is important from both scientific and public health perspectives, but it is poorly understood. The current research integrates person-centered analyses (e.g., latent profile analysis) and variable-centered analyses (e.g., exploratory factor analysis) to understand better the latent structure of dependence and to guide distillation of the phenotype. Using data from four samples of smokers (including treatment and non-treatment samples), latent profiles were derived using the Wisconsin Inventory of Smoking Dependence Motives (WISDM) subscale scores. Across all four samples, results revealed a unique latent profile that had relative elevations on four dependence motive subscales (Automaticity, Craving, Loss of Control, and Tolerance). Variable-centered analyses supported the uniqueness of these four subscales both as measures of a common factor distinct from that underlying the other nine subscales, and as the strongest predictors of relapse, withdrawal and other dependence criteria. Conversely, the remaining nine motives carried little unique predictive validity regarding dependence. Applications of a factor mixture model further support the presence of a unique class of smokers in relation to a common factor underlying the four subscales. The results illustrate how person-centered analyses may be useful as a supplement to variable-centered analyses for uncovering variables that are necessary and/or sufficient predictors of disorder criteria, as they may uncover small segments of a population in which the variables are uniquely distributed. The results also suggest that severe dependence is associated with a pattern of smoking that is heavy, pervasive, automatic and relatively unresponsive to instrumental contingencies. PMID:19025223

Do genetic risk scores for body mass index predict risk of phobic anxiety? Evidence for a shared genetic risk factor

PubMed Central

Walter, Stefan; Glymour, M. Maria; Koenen, Karestan; Liang, Liming; Tchetgen Tchetgen, Eric J; Cornelis, Marilyn; Chang, Shun-Chiao; Rewak, Marissa; Rimm, Eric; Kawachi, Ichiro; Kubzansky, Laura D.

2015-01-01

Background Obesity and anxiety are often linked but the direction of effects is not clear. Methods Using genetic instrumental variable (IV) analyses in a sample of 5911 female participants from the Nurses´ Health Study (NHS, initiated in 1976) and 3697 male participants from the Health Professional Follow-up Study (HPFS, initiated in 1986), we aim to determine whether obesity increases symptoms of phobic anxiety. FTO, MC4R, and a genetic risk score (GRS) based on 32 single nucleotide polymorphisms that significantly predict body mass index (BMI), were used as instrumental variables. “Functional” GRS corresponding with specific biological pathways that shape BMI (adipogenesis, appetite, and cardio-pulmonary), were considered. Phobic anxiety as measured by the Crown Crisp Experimental Index (CCI) in 2004 in NHS and 2000 in HPFS was the main outcome. Results In observational analysis, a one unit higher BMI was associated with higher phobic anxiety symptoms (women NHS: beta=0.05; 95% Confidence Interval (CI): 0.030 – 0.068 and men, HPFS, beta = 0.04; 95% CI: 0.016 – 0.071). IV analyses showed that BMI instrumented by FTO was associated with higher phobic anxiety symptoms (p = 0.005) but BMI instrumented by GRS was not (p=0.256). Functional GRS scores showed heterogeneous, non-significant effects of BMI on phobic anxiety symptoms. Conclusions Our findings do not provide conclusive evidence in favor of the hypothesis that higher BMI leads to higher levels of phobic anxiety, but rather suggest that genes that influence obesity, in particular FTO, may have direct effects on phobic anxiety, i.e., that obesity and phobic anxiety may share common genetic determinants. PMID:25065638

Do genetic risk scores for body mass index predict risk of phobic anxiety? Evidence for a shared genetic risk factor.

PubMed

Walter, S; Glymour, M M; Koenen, K; Liang, L; Tchetgen Tchetgen, E J; Cornelis, M; Chang, S-C; Rewak, M; Rimm, E; Kawachi, I; Kubzansky, L D

2015-01-01

Obesity and anxiety are often linked but the direction of effects is not clear. Using genetic instrumental variable (IV) analyses in 5911 female participants from the Nurses' Health Study (NHS, initiated 1976) and 3697 male participants from the Health Professional Follow-up Study (HPFS, initiated 1986), we aimed to determine whether obesity increases symptoms of phobic anxiety. As instrumental variables we used the fat mass and obesity-associated (FTO) gene, the melanocortin 4 receptor (MC4R) gene and a genetic risk score (GRS) based on 32 single nucleotide polymorphisms (SNPs) that significantly predict body mass index (BMI). 'Functional' GRSs corresponding with specific biological pathways that shape BMI (adipogenesis, appetite and cardiopulmonary) were considered. The main outcome was phobic anxiety measured by the Crown Crisp Index (CCI) in 2004 in the NHS and in 2000 in the HPFS. In observational analysis, a 1-unit higher BMI was associated with higher phobic anxiety symptoms [women: β = 0.05, 95% confidence interval (CI) 0.030-0.068; men: β = 0.04, 95% CI 0.016-0.071). IV analyses showed that BMI was associated with higher phobic anxiety symptoms in the FTO-instrumented analysis (p = 0.005) but not in the GRS-instrumented analysis (p = 0.256). Functional GRSs showed heterogeneous, non-significant effects of BMI on phobic anxiety symptoms. Our findings do not provide conclusive evidence in favor of the hypothesis that higher BMI leads to higher levels of phobic anxiety, but rather suggest that genes that influence obesity, in particular FTO, may have direct effects on phobic anxiety, and hence that obesity and phobic anxiety may share common genetic determinants.

Poverty and Child Development: A Longitudinal Study of the Impact of the Earned Income Tax Credit

PubMed Central

Hamad, Rita; Rehkopf, David H.

2016-01-01

Although adverse socioeconomic conditions are correlated with worse child health and development, the effects of poverty-alleviation policies are less understood. We examined the associations of the Earned Income Tax Credit (EITC) on child development and used an instrumental variable approach to estimate the potential impacts of income. We used data from the US National Longitudinal Survey of Youth (n = 8,186) during 1986–2000 to examine effects on the Behavioral Problems Index (BPI) and Home Observation Measurement of the Environment inventory (HOME) scores. We conducted 2 analyses. In the first, we used multivariate linear regressions with child-level fixed effects to examine the association of EITC payment size with BPI and HOME scores; in the second, we used EITC payment size as an instrument to estimate the associations of income with BPI and HOME scores. In linear regression models, higher EITC payments were associated with improved short-term BPI scores (per $1,000, β = −0.57; P = 0.04). In instrumental variable analyses, higher income was associated with improved short-term BPI scores (per $1,000, β = −0.47; P = 0.01) and medium-term HOME scores (per $1,000, β = 0.64; P = 0.02). Our results suggest that both EITC benefits and higher income are associated with modest but meaningful improvements in child development. These findings provide valuable information for health researchers and policymakers for improving child health and development. PMID:27056961

Short version of the "instrument for assessment of stress in nursing students" in the Brazilian reality.

PubMed

Costa, Ana Lúcia Siqueira; Silva, Rodrigo Marques da; Mussi, Fernanda Carneiro; Serrano, Patrícia Maria; Graziano, Eliane da Silva; Batista, Karla de Melo

2018-01-08

validate a short version of the Instrument for assessment of stress in nursing students in the Brazilian reality. Methodological study conducted with 1047 nursing students from five Brazilian institutions, who answered the 30 items initially distributed in eight domains. Data were analyzed in the R Statistical Package and in the latent variable analysis, using exploratory and confirmatory factor analyses, Cronbach's alpha and item-total correlation. The short version of the instrument had 19 items distributed into four domains: Environment, Professional Training, Theoretical Activities and Performance of Practical Activities. The confirmatory analysis showed absolute and parsimony fit to the proposed model with satisfactory residual levels. Alpha values ​​per factor ranged from 0.736 (Environment) to 0.842 (Performance of Practical Activities). The short version of the instrument has construct validity and reliability for application to Brazilian nursing undergraduates at any stage of the course.

The precision of wet atmospheric deposition data from national atmospheric deposition program/national trends network sites determined with collocated samplers

USGS Publications Warehouse

Nilles, M.A.; Gordon, J.D.; Schroder, L.J.

1994-01-01

A collocated, wet-deposition sampler program has been operated since October 1988 by the U.S. Geological Survey to estimate the overall sampling precision of wet atmospheric deposition data collected at selected sites in the National Atmospheric Deposition Program and National Trends Network (NADP/NTN). A duplicate set of wet-deposition sampling instruments was installed adjacent to existing sampling instruments at four different NADP/NTN sites for each year of the study. Wet-deposition samples from collocated sites were collected and analysed using standard NADP/NTN procedures. Laboratory analyses included determinations of pH, specific conductance, and concentrations of major cations and anions. The estimates of precision included all variability in the data-collection system, from the point of sample collection through storage in the NADP/NTN database. Sampling precision was determined from the absolute value of differences in the analytical results for the paired samples in terms of median relative and absolute difference. The median relative difference for Mg2+, Na+, K+ and NH4+ concentration and deposition was quite variable between sites and exceeded 10% at most sites. Relative error for analytes whose concentrations typically approached laboratory method detection limits were greater than for analytes that did not typically approach detection limits. The median relative difference for SO42- and NO3- concentration, specific conductance, and sample volume at all sites was less than 7%. Precision for H+ concentration and deposition ranged from less than 10% at sites with typically high levels of H+ concentration to greater than 30% at sites with low H+ concentration. Median difference for analyte concentration and deposition was typically 1.5-2-times greater for samples collected during the winter than during other seasons at two northern sites. Likewise, the median relative difference in sample volume for winter samples was more than double the annual median relative difference at the two northern sites. Bias accounted for less than 25% of the collocated variability in analyte concentration and deposition from weekly collocated precipitation samples at most sites.A collocated, wet-deposition sampler program has been operated since OCtober 1988 by the U.S Geological Survey to estimate the overall sampling precision of wet atmospheric deposition data collected at selected sites in the National Atmospheric Deposition Program and National Trends Network (NADP/NTN). A duplicate set of wet-deposition sampling instruments was installed adjacent to existing sampling instruments four different NADP/NTN sites for each year of the study. Wet-deposition samples from collocated sites were collected and analysed using standard NADP/NTN procedures. Laboratory analyses included determinations of pH, specific conductance, and concentrations of major cations and anions. The estimates of precision included all variability in the data-collection system, from the point of sample collection through storage in the NADP/NTN database.

The Perceptions of Fair Interpersonal Treatment Scale: development and validation of a measure of interpersonal treatment in the workplace.

PubMed

Donovan, M A; Drasgow, F; Munson, L J

1998-10-01

The Perceptions of Fair Interpersonal Treatment (PFIT) scale was designed to assess employees' perceptions of the interpersonal treatment in their work environment. Analyses of the factor structure and reliability of this new instrument indicate that the PFIT scale is a reliable instrument composed of 2 factors: supervisor treatment and coworker treatment. It was hypothesized that the PFIT scale would be positively correlated with job satisfaction variables and negatively correlated with work withdrawal, job withdrawal, experiences of sexual harassment, and an organization's tolerance of sexual harassment. Results based on 509 employees in a private-sector organization and 217 female faculty and staff members at a large midwestern university supported these hypotheses. Arguments that common method variance and employees' dispositions are responsible for the significant correlations between the PFIT scale and other job-related variables were eliminated. The implications of these results are discussed.

CEOS SEO and GISS Meeting

NASA Technical Reports Server (NTRS)

Killough, Brian; Stover, Shelley

2008-01-01

The Committee on Earth Observation Satellites (CEOS) provides a brief to the Goddard Institute for Space Studies (GISS) regarding the CEOS Systems Engineering Office (SEO) and current work on climate requirements and analysis. A "system framework" is provided for the Global Earth Observation System of Systems (GEOSS). SEO climate-related tasks are outlined including the assessment of essential climate variable (ECV) parameters, use of the "systems framework" to determine relevant informational products and science models and the performance of assessments and gap analyses of measurements and missions for each ECV. Climate requirements, including instruments and missions, measurements, knowledge and models, and decision makers, are also outlined. These requirements would establish traceability from instruments to products and services allowing for benefit evaluation of instruments and measurements. Additionally, traceable climate requirements would provide a better understanding of global climate models.

Outcomes after helicopter versus ground emergency medical services for major trauma--propensity score and instrumental variable analyses: a retrospective nationwide cohort study.

PubMed

Tsuchiya, Asuka; Tsutsumi, Yusuke; Yasunaga, Hideo

2016-11-29

Because of a lack of randomized controlled trials and the methodological weakness of currently available observational studies, the benefits of helicopter emergency medical services (HEMS) over ground emergency medical services (GEMS) for major trauma patients remain uncertain. The aim of this retrospective nationwide cohort study was to compare the mortality of adults with serious traumatic injuries who were transported by HEMS and GEMS, and to analyze the effects of HEMS in various subpopulations. Using the Japan Trauma Data Bank, we evaluated all adult patients who had an injury severity score ≥ 16 transported by HEMS or GEMS during the daytime between 2004 and 2014. We compared in-hospital mortality between patients transported by HEMS and GEMS using propensity score matching, inverse probability of treatment weighting and instrumental variable analyses to adjust for measured and unmeasured confounding factors. Eligible patients (n = 21,286) from 192 hospitals included 4128 transported by HEMS and 17,158 transported by GEMS. In the propensity score-matched model, there was a significant difference in the in-hospital mortality between HEMS and GEMS groups (22.2 vs. 24.5%, risk difference -2.3% [95% confidence interval, -4.2 to -0.5]; number needed to treat, 43 [95% confidence interval, 24 to 220]). The inverse probability of treatment weighting (20.8% vs. 23.9%; risk difference, -3.9% [95% confidence interval, -5.7 to -2.1]; number needed to treat, 26 [95% confidence interval, 17 to 48]) and instrumental variable analyses showed similar results (risk difference, -6.5% [95% confidence interval, -9.2 to -3.8]; number needed to treat, 15 [95% confidence interval, 11 to 27]). HEMS transport was significantly associated with lower in-hospital mortality after falls, compression injuries, severe chest injuries, extremity (including pelvic) injuries, and traumatic arrest on arrival to the emergency department. HEMS was associated with a significantly lower mortality than GEMS in adult patients with major traumatic injuries after adjusting for measured and unmeasured confounders.

Liquid Medication Dosing Errors in Children: Role of Provider Counseling Strategies

PubMed Central

Yin, H. Shonna; Dreyer, Benard P.; Moreira, Hannah A.; van Schaick, Linda; Rodriguez, Luis; Boettger, Susanne; Mendelsohn, Alan L.

2014-01-01

Objective To examine the degree to which recommended provider counseling strategies, including advanced communication techniques and dosing instrument provision, are associated with reductions in parent liquid medication dosing errors. Methods Cross-sectional analysis of baseline data on provider communication and dosing instrument provision from a study of a health literacy intervention to reduce medication errors. Parents whose children (<9 years) were seen in two urban public hospital pediatric emergency departments (EDs) and were prescribed daily dose liquid medications self-reported whether they received counseling about their child’s medication, including advanced strategies (teachback, drawings/pictures, demonstration, showback) and receipt of a dosing instrument. Primary dependent variable: observed dosing error (>20% deviation from prescribed). Multivariate logistic regression analyses performed, controlling for: parent age, language, country, ethnicity, socioeconomic status, education, health literacy (Short Test of Functional Health Literacy in Adults); child age, chronic disease status; site. Results Of 287 parents, 41.1% made dosing errors. Advanced counseling and instrument provision in the ED were reported by 33.1% and 19.2%, respectively; 15.0% reported both. Advanced counseling and instrument provision in the ED were associated with decreased errors (30.5 vs. 46.4%, p=0.01; 21.8 vs. 45.7%, p=0.001). In adjusted analyses, ED advanced counseling in combination with instrument provision was associated with a decreased odds of error compared to receiving neither (AOR 0.3; 95% CI 0.1–0.7); advanced counseling alone and instrument alone were not significantly associated with odds of error. Conclusion Provider use of advanced counseling strategies and dosing instrument provision may be especially effective in reducing errors when used together. PMID:24767779

Liquid medication dosing errors in children: role of provider counseling strategies.

PubMed

Yin, H Shonna; Dreyer, Benard P; Moreira, Hannah A; van Schaick, Linda; Rodriguez, Luis; Boettger, Susanne; Mendelsohn, Alan L

2014-01-01

To examine the degree to which recommended provider counseling strategies, including advanced communication techniques and dosing instrument provision, are associated with reductions in parent liquid medication dosing errors. Cross-sectional analysis of baseline data on provider communication and dosing instrument provision from a study of a health literacy intervention to reduce medication errors. Parents whose children (<9 years) were seen in 2 urban public hospital pediatric emergency departments (EDs) and were prescribed daily dose liquid medications self-reported whether they received counseling about their child's medication, including advanced strategies (teachback, drawings/pictures, demonstration, showback) and receipt of a dosing instrument. The primary dependent variable was observed dosing error (>20% deviation from prescribed). Multivariate logistic regression analyses were performed, controlling for parent age, language, country, ethnicity, socioeconomic status, education, health literacy (Short Test of Functional Health Literacy in Adults); child age, chronic disease status; and site. Of 287 parents, 41.1% made dosing errors. Advanced counseling and instrument provision in the ED were reported by 33.1% and 19.2%, respectively; 15.0% reported both. Advanced counseling and instrument provision in the ED were associated with decreased errors (30.5 vs. 46.4%, P = .01; 21.8 vs. 45.7%, P = .001). In adjusted analyses, ED advanced counseling in combination with instrument provision was associated with a decreased odds of error compared to receiving neither (adjusted odds ratio 0.3; 95% confidence interval 0.1-0.7); advanced counseling alone and instrument alone were not significantly associated with odds of error. Provider use of advanced counseling strategies and dosing instrument provision may be especially effective in reducing errors when used together. Copyright © 2014 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Development process and initial validation of the Ethical Conflict in Nursing Questionnaire-Critical Care Version.

PubMed

Falcó-Pegueroles, Anna; Lluch-Canut, Teresa; Guàrdia-Olmos, Joan

2013-06-01

Ethical conflicts are arising as a result of the growing complexity of clinical care, coupled with technological advances. Most studies that have developed instruments for measuring ethical conflict base their measures on the variables 'frequency' and 'degree of conflict'. In our view, however, these variables are insufficient for explaining the root of ethical conflicts. Consequently, the present study formulates a conceptual model that also includes the variable 'exposure to conflict', as well as considering six 'types of ethical conflict'. An instrument was then designed to measure the ethical conflicts experienced by nurses who work with critical care patients. The paper describes the development process and validation of this instrument, the Ethical Conflict in Nursing Questionnaire Critical Care Version (ECNQ-CCV). The sample comprised 205 nursing professionals from the critical care units of two hospitals in Barcelona (Spain). The ECNQ-CCV presents 19 nursing scenarios with the potential to produce ethical conflict in the critical care setting. Exposure to ethical conflict was assessed by means of the Index of Exposure to Ethical Conflict (IEEC), a specific index developed to provide a reference value for each respondent by combining the intensity and frequency of occurrence of each scenario featured in the ECNQ-CCV. Following content validity, construct validity was assessed by means of Exploratory Factor Analysis (EFA), while Cronbach's alpha was used to evaluate the instrument's reliability. All analyses were performed using the statistical software PASW v19. Cronbach's alpha for the ECNQ-CCV as a whole was 0.882, which is higher than the values reported for certain other related instruments. The EFA suggested a unidimensional structure, with one component accounting for 33.41% of the explained variance. The ECNQ-CCV is shown to a valid and reliable instrument for use in critical care units. Its structure is such that the four variables on which our model of ethical conflict is based may be studied separately or in combination. The critical care nurses in this sample present moderate levels of exposure to ethical conflict. This study represents the first evaluation of the ECNQ-CCV.

Integrated Response Time Evaluation Methodology for the Nuclear Safety Instrumentation System

NASA Astrophysics Data System (ADS)

Lee, Chang Jae; Yun, Jae Hee

2017-06-01

Safety analysis for a nuclear power plant establishes not only an analytical limit (AL) in terms of a measured or calculated variable but also an analytical response time (ART) required to complete protective action after the AL is reached. If the two constraints are met, the safety limit selected to maintain the integrity of physical barriers used for preventing uncontrolled radioactivity release will not be exceeded during anticipated operational occurrences and postulated accidents. Setpoint determination methodologies have actively been developed to ensure that the protective action is initiated before the process conditions reach the AL. However, regarding the ART for a nuclear safety instrumentation system, an integrated evaluation methodology considering the whole design process has not been systematically studied. In order to assure the safety of nuclear power plants, this paper proposes a systematic and integrated response time evaluation methodology that covers safety analyses, system designs, response time analyses, and response time tests. This methodology is applied to safety instrumentation systems for the advanced power reactor 1400 and the optimized power reactor 1000 nuclear power plants in South Korea. The quantitative evaluation results are provided herein. The evaluation results using the proposed methodology demonstrate that the nuclear safety instrumentation systems fully satisfy corresponding requirements of the ART.

Falsification Testing of Instrumental Variables Methods for Comparative Effectiveness Research.

PubMed

Pizer, Steven D

2016-04-01

To demonstrate how falsification tests can be used to evaluate instrumental variables methods applicable to a wide variety of comparative effectiveness research questions. Brief conceptual review of instrumental variables and falsification testing principles and techniques accompanied by an empirical application. Sample STATA code related to the empirical application is provided in the Appendix. Comparative long-term risks of sulfonylureas and thiazolidinediones for management of type 2 diabetes. Outcomes include mortality and hospitalization for an ambulatory care-sensitive condition. Prescribing pattern variations are used as instrumental variables. Falsification testing is an easily computed and powerful way to evaluate the validity of the key assumption underlying instrumental variables analysis. If falsification tests are used, instrumental variables techniques can help answer a multitude of important clinical questions. © Health Research and Educational Trust.

Tutorial in Biostatistics: Instrumental Variable Methods for Causal Inference*

PubMed Central

Baiocchi, Michael; Cheng, Jing; Small, Dylan S.

2014-01-01

A goal of many health studies is to determine the causal effect of a treatment or intervention on health outcomes. Often, it is not ethically or practically possible to conduct a perfectly randomized experiment and instead an observational study must be used. A major challenge to the validity of observational studies is the possibility of unmeasured confounding (i.e., unmeasured ways in which the treatment and control groups differ before treatment administration which also affect the outcome). Instrumental variables analysis is a method for controlling for unmeasured confounding. This type of analysis requires the measurement of a valid instrumental variable, which is a variable that (i) is independent of the unmeasured confounding; (ii) affects the treatment; and (iii) affects the outcome only indirectly through its effect on the treatment. This tutorial discusses the types of causal effects that can be estimated by instrumental variables analysis; the assumptions needed for instrumental variables analysis to provide valid estimates of causal effects and sensitivity analysis for those assumptions; methods of estimation of causal effects using instrumental variables; and sources of instrumental variables in health studies. PMID:24599889

[Instruments for quantitative methods of nursing research].

PubMed

Vellone, E

2000-01-01

Instruments for quantitative nursing research are a mean to objectify and measure a variable or a phenomenon in the scientific research. There are direct instruments to measure concrete variables and indirect instruments to measure abstract concepts (Burns, Grove, 1997). Indirect instruments measure the attributes by which a concept is made of. Furthermore, there are instruments for physiologic variables (e.g. for the weight), observational instruments (Check-lists e Rating Scales), interviews, questionnaires, diaries and the scales (Check-lists, Rating Scales, Likert Scales, Semantic Differential Scales e Visual Anologue Scales). The choice to select an instrument or another one depends on the research question and design. Instruments research are very useful in research both to describe the variables and to see statistical significant relationships. Very carefully should be their use in the clinical practice for diagnostic assessment.

The long view: Causes of climate change over the instrumental period

NASA Astrophysics Data System (ADS)

Hegerl, G. C.; Schurer, A. P.; Polson, D.; Iles, C. E.; Bronnimann, S.

2016-12-01

The period of instrumentally recorded data has seen remarkable changes in climate, with periods of rapid warming, and periods of stagnation or cooling. A recent analysis of the observed temperature change from the instrumental record confirms that most of the warming recorded since the middle of the 20rst century has been caused by human influences, but shows large uncertainty in separating greenhouse gas from aerosol response if accounting for model uncertainty. The contribution by natural forcing and internal variability to the recent warming is estimated to be small, but becomes more important when analysing climate change over earlier or shorter time periods. For example, the enigmatic early 20th century warming was a period of strong climate anomalies, including the US dustbowl drought and exceptional heat waves, and pronounced Arctic warming. Attribution results suggests that about half of the global warming 1901-1950 was forced by greenhouse gases increases, with an anomalously strong contribution by climate variability, and contributions by natural forcing. Long term variations in circulation are important for some regional climate anomalies. Precipitation is important for impacts of climate change and precipitation changes are uncertain in models. Analysis of the instrumental record suggests a human influence on mean and heavy precipitation, and supports climate model estimates of the spatial pattern of precipitation sensitivity to warming. Broadly, and particularly over ocean, wet regions are getting wetter and dry regions are getting drier. In conclusion, the historical record provides evidence for a strong response to external forcings, supports climate models, and raises questions about multi-decadal variability.

Robust inference in summary data Mendelian randomization via the zero modal pleiotropy assumption.

PubMed

Hartwig, Fernando Pires; Davey Smith, George; Bowden, Jack

2017-12-01

Mendelian randomization (MR) is being increasingly used to strengthen causal inference in observational studies. Availability of summary data of genetic associations for a variety of phenotypes from large genome-wide association studies (GWAS) allows straightforward application of MR using summary data methods, typically in a two-sample design. In addition to the conventional inverse variance weighting (IVW) method, recently developed summary data MR methods, such as the MR-Egger and weighted median approaches, allow a relaxation of the instrumental variable assumptions. Here, a new method - the mode-based estimate (MBE) - is proposed to obtain a single causal effect estimate from multiple genetic instruments. The MBE is consistent when the largest number of similar (identical in infinite samples) individual-instrument causal effect estimates comes from valid instruments, even if the majority of instruments are invalid. We evaluate the performance of the method in simulations designed to mimic the two-sample summary data setting, and demonstrate its use by investigating the causal effect of plasma lipid fractions and urate levels on coronary heart disease risk. The MBE presented less bias and lower type-I error rates than other methods under the null in many situations. Its power to detect a causal effect was smaller compared with the IVW and weighted median methods, but was larger than that of MR-Egger regression, with sample size requirements typically smaller than those available from GWAS consortia. The MBE relaxes the instrumental variable assumptions, and should be used in combination with other approaches in sensitivity analyses. © The Author 2017. Published by Oxford University Press on behalf of the International Epidemiological Association

Statistical evaluation of control inputs and eye movements in the use of instruments clusters during aircraft landing

NASA Technical Reports Server (NTRS)

Dick, A. O.; Brown, J. L.; Bailey, G.

1977-01-01

Two different types of analyses were done on data from a study in which eye movements and other variables were recorded while four pilots executed landing sequences in a Boeing 737 simulation. Various conditions were manupulated, including changes in turbulence, starting position, and instrumentation. Control inputs were analyzed in the context of the various conditions and compared against ratings of workload obtained using the Cooper-Harper scale. A number of eye-scanning measures including mean dwell time and transition from one instrument to another were entered into a principal components factor analysis. The results show a differentiation between control inputs and eye-scanning behavior. This shows the need for improved definition of workload and experiments to uncover the important differences among control inputs, eye-scanning and cognitive processes of the pilot.

Validation of Spacecraft Active Cavity Radiometer Total Solar Irradiance (TSI) Long Term Measurement Trends Using Proxy TSI Least Squares Analyses

NASA Technical Reports Server (NTRS)

Lee, Robert Benjamin, III; Wilson, Robert S.

2003-01-01

Long-term, incoming total solar irradiance (TSI) measurement trends were validated using proxy TSI values, derived from indices of solar magnetic activity. Spacecraft active cavity radiometers (ACR) are being used to measure longterm TSI variability, which may trigger global climate changes. The TSI, typically referred to as the solar constant, was normalized to the mean earth-sun distance. Studies of spacecraft TSI data sets confirmed the existence of a 0.1 %, long-term TSI variability component within a 10-year period. The 0.1% TSI variability component is clearly present in the spacecraft data sets from the 1984-2004 time frame. Typically, three overlapping spacecraft data sets were used to validate long-term TSI variability trends. However, during the years of 1978-1984, 1989-1991, and 1993-1996, three overlapping spacecraft data sets were not available in order to validate TSI trends. The TSI was found to vary with indices of solar magnetic activity associated with recent 10-year sunspot cycles. Proxy TSI values were derived from least squares analyses of the measured TSI variability with the solar indices of 10.7-cm solar fluxes, and with limb-darked sunspot fluxes. The resulting proxy TSI values were compared to the spacecraft ACR measurements of TSI variability to detect ACR instrument degradation, which may be interpreted as TSI variability. Analyses of ACR measurements and TSI proxies are presented primarily for the 1984-2004, Earth Radiation Budget Experiment (ERBE) ACR solar monitor data set. Differences in proxy and spacecraft measurement data sets suggest the existence of another TSI variability component with an amplitude greater than or equal to 0.5 Wm-2 (0.04%), and with a cycle of 20 years or more.

Is more better than less? An analysis of children's mental health services.

PubMed Central

Foster, E M

2000-01-01

OBJECTIVE: To assess the dose-response relationship for outpatient therapy received by children and adolescents-that is, to determine the impact of added outpatient visits on key mental health outcomes (functioning and symptomatology). DATA SOURCES/STUDY SETTING: The results presented involve analyses of data from the Fort Bragg Demonstration and are based on a sample of 301 individuals using outpatient services. STUDY DESIGN: This article provides estimates of the impact of outpatient therapy based on comparisons of individuals receiving differing treatment doses. Those comparisons involve standard multiple regression analyses as well as instrumental variables estimation. The latter provides a means of adjusting comparisons for unobserved or unmeasured differences among individuals receiving differing doses, differences that would otherwise be confounded with the impact of treatment dose. DATA COLLECTION/EXTRACTION METHODS: Using structured diagnostic interviews and behavior checklists completed by the child and his or her caretaker, detailed data on psychopathology, symptomatology, and psychosocial functioning were collected on individuals included in these analyses. Information on the use of mental health services was taken from insurance claims and a management information system. Services data were used to describe the use of outpatient therapy within the year following entry into the study. PRINCIPAL FINDINGS/CONCLUSIONS: Instrumental variables estimation indicates that added outpatient therapy improves functioning among children and adolescents. The effect is statistically significant and of moderate practical magnitude. These results imply that conventional analyses of the dose-response relationship may understate the impact of additional treatment on functioning. This finding is robust to choice of functional form, length of time over which outcomes are measured, and model specification. Dose does not appear to influence symptomatology. PMID:11130814

Eliminating Survivor Bias in Two-stage Instrumental Variable Estimators.

PubMed

Vansteelandt, Stijn; Walter, Stefan; Tchetgen Tchetgen, Eric

2018-07-01

Mendelian randomization studies commonly focus on elderly populations. This makes the instrumental variables analysis of such studies sensitive to survivor bias, a type of selection bias. A particular concern is that the instrumental variable conditions, even when valid for the source population, may be violated for the selective population of individuals who survive the onset of the study. This is potentially very damaging because Mendelian randomization studies are known to be sensitive to bias due to even minor violations of the instrumental variable conditions. Interestingly, the instrumental variable conditions continue to hold within certain risk sets of individuals who are still alive at a given age when the instrument and unmeasured confounders exert additive effects on the exposure, and moreover, the exposure and unmeasured confounders exert additive effects on the hazard of death. In this article, we will exploit this property to derive a two-stage instrumental variable estimator for the effect of exposure on mortality, which is insulated against the above described selection bias under these additivity assumptions.

[Measuring job satisfaction: development of a multidimensional scale].

PubMed

Faraci, Palmira; Valenti, Giusy

2016-01-01

Although numerous studies have been done on the topic ofjob satisfaction, as regards the Italian research, the construction of specific psychometric instruments is lacking. The present paper is aimed to develop a scale to measure job satisfaction referring to our cultural context. Participants were 222 workers (36.5% males, 63.5% females) with an average age of 38.39 years (SD = 10.91). The formulated items were selected from a large item pool on the basis of the evaluation by a group of expert judges, and the item analysis procedure. In order to establish test validity, the following instruments were also administered: Occupational Stress Indicator, Satisfaction With Life Scale, Rosenberg Self-Esteem Scale, Multidimensional Scale of Perceived Social Support, and Beck Depression Inventory. Both exploratory and confirmatory factor analyses highlighted a 6-factor structure. Those factors were responsible for 51.30% of the total variance. Reliability analyses indicated satisfying internal consistency (ranging from alpha = .73 to alpha = .86). Construct validity was supported by results obtained calculating correlations with the theoretically associated variables. Our findings suggest promising psychometric properties for the presented measure. The instrument could be used in specific programs developed to promote well-being conditions in work settings.

Parental representations in drug-dependent patients and their parents.

PubMed

Torresani, S; Favaretto, E; Zimmermann, C

2000-01-01

The Parental Bonding Instrument (PBI), a measure of perceived parental care and protection, was administered to drug-dependent patients and their parents with the aim to assess the reliability of the instrument in such samples and to compare the parental representations across generations. Ninety drug-dependent patients and 44 mothers and 35 fathers participated. Reliability indices were calculated, and parental representations of parents and their offspring were compared. Linear regression analyses were performed with the patient's PBI score as the dependent variable and the mother's and father's PBI scores as predictor variables. The reliability indices were highly satisfactory and varied between 0.61 and 0.91. The parental bonding of patients, fathers, and mothers was similar. All three groups reported high maternal and paternal control and low maternal care, a pattern characteristic of an "affectionless control" rearing style. Maternal care received by the fathers and paternal protection received by the mothers predicted the care and protection they themselves gave to their drug-dependent offspring.

Implementation of Instrumental Variable Bounds for Data Missing Not at Random.

PubMed

Marden, Jessica R; Wang, Linbo; Tchetgen, Eric J Tchetgen; Walter, Stefan; Glymour, M Maria; Wirth, Kathleen E

2018-05-01

Instrumental variables are routinely used to recover a consistent estimator of an exposure causal effect in the presence of unmeasured confounding. Instrumental variable approaches to account for nonignorable missing data also exist but are less familiar to epidemiologists. Like instrumental variables for exposure causal effects, instrumental variables for missing data rely on exclusion restriction and instrumental variable relevance assumptions. Yet these two conditions alone are insufficient for point identification. For estimation, researchers have invoked a third assumption, typically involving fairly restrictive parametric constraints. Inferences can be sensitive to these parametric assumptions, which are typically not empirically testable. The purpose of our article is to discuss another approach for leveraging a valid instrumental variable. Although the approach is insufficient for nonparametric identification, it can nonetheless provide informative inferences about the presence, direction, and magnitude of selection bias, without invoking a third untestable parametric assumption. An important contribution of this article is an Excel spreadsheet tool that can be used to obtain empirical evidence of selection bias and calculate bounds and corresponding Bayesian 95% credible intervals for a nonidentifiable population proportion. For illustrative purposes, we used the spreadsheet tool to analyze HIV prevalence data collected by the 2007 Zambia Demographic and Health Survey (DHS).

Analysis of intraosseous samples using point of care technology--an experimental study in the anaesthetised pig.

PubMed

Strandberg, Gunnar; Eriksson, Mats; Gustafsson, Mats G; Lipcsey, Miklós; Larsson, Anders

2012-11-01

Intraosseous access is an essential method in emergency medicine when other forms of vascular access are unavailable and there is an urgent need for fluid or drug therapy. A number of publications have discussed the suitability of using intraosseous access for laboratory testing. We aimed to further evaluate this issue and to study the accuracy and precision of intraosseous measurements. Five healthy, anaesthetised pigs were instrumented with bilateral tibial intraosseous cannulae and an arterial catheter. Samples were collected hourly for 6h and analysed for blood gases, acid base status, haemoglobin and electrolytes using an I-Stat point of care analyser. There was no clinically relevant difference between results from left and right intraosseous sites. The variability of the intraosseous sample values, measured as the coefficient of variance (CV), was maximally 11%, and smaller than for the arterial sample values for all variables except SO2. For most variables, there seems to be some degree of systematic difference between intraosseous and arterial results. However, the direction of this difference seems to be predictable. Based on our findings in this animal model, cartridge based point of care instruments appear suitable for the analysis of intraosseous samples. The agreement between intraosseous and arterial analysis seems to be good enough for the method to be clinically useful. The precision, quantified in terms of CV, is at least as good for intraosseous as for arterial analysis. There is no clinically important difference between samples from left and right tibia, indicating a good reproducibility. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Development process and initial validation of the Ethical Conflict in Nursing Questionnaire-Critical Care Version

PubMed Central

2013-01-01

Background Ethical conflicts are arising as a result of the growing complexity of clinical care, coupled with technological advances. Most studies that have developed instruments for measuring ethical conflict base their measures on the variables ‘frequency’ and ‘degree of conflict’. In our view, however, these variables are insufficient for explaining the root of ethical conflicts. Consequently, the present study formulates a conceptual model that also includes the variable ‘exposure to conflict’, as well as considering six ‘types of ethical conflict’. An instrument was then designed to measure the ethical conflicts experienced by nurses who work with critical care patients. The paper describes the development process and validation of this instrument, the Ethical Conflict in Nursing Questionnaire Critical Care Version (ECNQ-CCV). Methods The sample comprised 205 nursing professionals from the critical care units of two hospitals in Barcelona (Spain). The ECNQ-CCV presents 19 nursing scenarios with the potential to produce ethical conflict in the critical care setting. Exposure to ethical conflict was assessed by means of the Index of Exposure to Ethical Conflict (IEEC), a specific index developed to provide a reference value for each respondent by combining the intensity and frequency of occurrence of each scenario featured in the ECNQ-CCV. Following content validity, construct validity was assessed by means of Exploratory Factor Analysis (EFA), while Cronbach’s alpha was used to evaluate the instrument’s reliability. All analyses were performed using the statistical software PASW v19. Results Cronbach’s alpha for the ECNQ-CCV as a whole was 0.882, which is higher than the values reported for certain other related instruments. The EFA suggested a unidimensional structure, with one component accounting for 33.41% of the explained variance. Conclusions The ECNQ-CCV is shown to a valid and reliable instrument for use in critical care units. Its structure is such that the four variables on which our model of ethical conflict is based may be studied separately or in combination. The critical care nurses in this sample present moderate levels of exposure to ethical conflict. This study represents the first evaluation of the ECNQ-CCV. PMID:23725477

Template-Directed Instrumentation Reduces Cost and Improves Efficiency for Total Knee Arthroplasty: An Economic Decision Analysis and Pilot Study.

PubMed

McLawhorn, Alexander S; Carroll, Kaitlin M; Blevins, Jason L; DeNegre, Scott T; Mayman, David J; Jerabek, Seth A

2015-10-01

Template-directed instrumentation (TDI) for total knee arthroplasty (TKA) may streamline operating room (OR) workflow and reduce costs by preselecting implants and minimizing instrument tray burden. A decision model simulated the economics of TDI. Sensitivity analyses determined thresholds for model variables to ensure TDI success. A clinical pilot was reviewed. The accuracy of preoperative templates was validated, and 20 consecutive primary TKAs were performed using TDI. The model determined that preoperative component size estimation should be accurate to ±1 implant size for 50% of TKAs to implement TDI. The pilot showed that preoperative template accuracy exceeded 97%. There were statistically significant improvements in OR turnover time and in-room time for TDI compared to an historical cohort of TKAs. TDI reduces costs and improves OR efficiency. Copyright © 2015 Elsevier Inc. All rights reserved.

The Self-Presentation Motives for Physical Activity Questionnaire: Instrument Development and Preliminary Construct Validity Evidence.

PubMed

Howle, Timothy C; Dimmock, James A; Whipp, Peter R; Jackson, Ben

2015-06-01

With the aim of advancing the literature on impression management in physical activity settings, we developed a theoretically derived 2 by 2 instrument that was designed to measure different types of context-specific self-presentation motives. Following item generation and expert review (Study 1), the instrument was completed by 206 group exercise class attendees (Study 2) and 463 high school physical education students (Study 3). Our analyses supported the intended factor structure (i.e., reflecting acquisitive-agentic, acquisitive-communal, protective-agentic, and protective-communal motives). We found some support for construct validity, and the self-presentation motives were associated with variables of theoretical and applied interest (e.g., impression motivation and construction, social anxiety, social and achievement goals, efficacy beliefs, engagement). Taken together, the results indicate that the Self-presentation Motives for Physical Activity Questionnaire (SMPAQ) may be useful for measuring various types of self-presentation motives in physical activity settings.

Factors explaining children's responses to intravenous needle insertions.

PubMed

McCarthy, Ann Marie; Kleiber, Charmaine; Hanrahan, Kirsten; Zimmerman, M Bridget; Westhus, Nina; Allen, Susan

2010-01-01

Previous research shows that numerous child, parent, and procedural variables affect children's distress responses to procedures. Cognitive-behavioral interventions such as distraction are effective in reducing pain and distress for many children undergoing these procedures. The purpose of this report was to examine child, parent, and procedural variables that explain child distress during a scheduled intravenous insertion when parents are distraction coaches for their children. A total of 542 children, between 4 and 10 years of age, and their parents participated. Child age, gender, diagnosis, and ethnicity were measured by questions developed for this study. Standardized instruments were used to measure child experience with procedures, temperament, ability to attend, anxiety, coping style, and pain sensitivity. Questions were developed to measure parent variables, including ethnicity, gender, previous experiences, and expectations, and procedural variables, including use of topical anesthetics and difficulty of procedure. Standardized instruments were used to measure parenting style and parent anxiety, whereas a new instrument was developed to measure parent performance of distraction. Children's distress responses were measured with the Observation Scale of Behavioral Distress-Revised (behavioral), salivary cortisol (biological), Oucher Pain Scale (self-report), and parent report of child distress (parent report). Regression methods were used for data analyses. Variables explaining behavioral, child-report and parent-report measures include child age, typical coping response, and parent expectation of distress (p < .01). Level of parents' distraction coaching explained a significant portion of behavioral, biological, and parent-report distress measures (p < .05). Child impulsivity and special assistance at school also significantly explained child self-report of pain (p < .05). Additional variables explaining cortisol response were child's distress in the morning before clinic, diagnoses of attention deficit hyperactivity disorder or anxiety disorder, and timing of preparation for the clinic visit. The findings can be used to identify children at risk for high distress during procedures. This is the first study to find a relationship between child behavioral distress and level of parent distraction coaching.

Measuring Food Brand Awareness in Australian Children: Development and Validation of a New Instrument.

PubMed

Turner, Laura; Kelly, Bridget; Boyland, Emma; Bauman, Adrian E

2015-01-01

Children's exposure to food marketing is one environmental determinant of childhood obesity. Measuring the extent to which children are aware of food brands may be one way to estimate relative prior exposures to food marketing. This study aimed to develop and validate an Australian Brand Awareness Instrument (ABAI) to estimate children's food brand awareness. The ABAI incorporated 30 flashcards depicting food/drink logos and their corresponding products. An abbreviated version was also created using 12 flashcards (ABAI-a). The ABAI was presented to 60 primary school aged children (7-11 yrs) attending two Australian after-school centres. A week later, the full-version was repeated on approximately half the sample (n=27) and the abbreviated-version was presented to the remaining half (n=30). The test-retest reliability of the ABAI was analysed using Intra-class correlation coefficients. The concordance of the ABAI-a and full-version was assessed using Bland-Altman plots. The 'nomological' validity of the full tool was investigated by comparing children's brand awareness with food marketing-related variables (e.g. television habits, intake of heavily promoted foods). Brand awareness increased with age (p<0.01) but was not significantly correlated with other variables. Bland-Altman analyses showed good agreement between the ABAI and ABAI-a. Reliability analyses revealed excellent agreement between the two administrations of the full-ABAI. The ABAI was able to differentiate children's varying levels of brand awareness. It was shown to be a valid and reliable tool and may allow quantification of brand awareness as a proxy measure for children's prior food marketing exposure.

Temporary stages and motivational variables: Two complementary perspectives in the help-seeking process for mental disorders.

PubMed

Del Valle Del Valle, Gema; Carrió, Carmen; Belloch, Amparo

2017-10-09

Help-seeking for mental disorders is a complex process, which includes different temporary stages, and in which the motivational variables play an especially relevant role. However, there is a lack of instruments to evaluate in depth both the temporary and motivational variables involved in the help-seeking process. This study aims to analyse in detail these two sets of variables, using a specific instrument designed for the purpose, to gain a better understanding of the process of treatment seeking. A total of 152 patients seeking treatment in mental health outpatient clinics of the NHS were individually interviewed: 71 had Obsessive-Compulsive Disorder, 21 had Agoraphobia, 18 had Major Depressive Disorder), 20 had Anorexia Nervosa, and 22 had Cocaine Dependence. The patients completed a structured interview assessing the help-seeking process. Disorder severity and quality of life was also assessed. The patients with agoraphobia and with major depression took significantly less time in recognising their mental health symptoms. Similarly, patients with major depression were faster in seeking professional help. Motivational variables were grouped in 3 sets: motivators for seeking treatment, related to the negative impact of symptoms on mood and to loss of control over symptoms; motivators for delaying treatment, related to minimisation of the disorder; and stigma-associated variables. The results support the importance of considering the different motivational variables involved in the several stages of the help-seeking process. The interview designed to that end has shown its usefulness in this endeavour. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

The use of a combination of instrumental methods to assess change in sensory crispness during storage of a "Honeycrisp" apple breeding family.

PubMed

Chang, Hsueh-Yuan; Vickers, Zata M; Tong, Cindy B S

2018-04-01

Loss of crispness in apple fruit during storage reduces the fruit's fresh sensation and consumer acceptance. Apple varieties that maintain crispness thus have higher potential for longer-term consumer appeal. To efficiently phenotype crispness, several instrumental methods have been tested, but variable results were obtained when different apple varieties were assayed. To extend these studies, we assessed the extent to which instrumental measurements correlate to and predict sensory crispness, with a focus on crispness maintenance. We used an apple breeding family derived from a cross between "Honeycrisp" and "MN1764," which segregates for crispness maintenance. Three types of instrumental measurements (puncture, snapping, and mechanical-acoustic tests) and sensory evaluation were performed on fruit at harvest and after 8 weeks of cold storage. Overall, 20 genotypes from the family and the 2 parents were characterized by 19 force and acoustic measures. In general, crispness was more related to force than to acoustic measures. Force linear distance and maximum force as measured by the mechanical-acoustic test were best correlated with sensory crispness and change in crispness, respectively. The correlations varied by apple genotype. The best multiple linear regression model to predict change in sensory crispness between harvest and storage of fruit of this breeding family incorporated both force and acoustic measures. This work compared the abilities of instrumental tests to predict sensory crispness maintenance of apple fruit. The use of an instrumental method that is highly correlated to sensory crispness evaluation can enhance the efficiency and reduce the cost of measuring crispness for breeding purposes. This study showed that sensory crispness and change in crispness after storage of an apple breeding family were reliably predicted with a combination of instrumental measurements and multiple variable analyses. The strategy potentially can be applied to other apple varieties for more accurate interpretation of crispness maintenance measured instrumentally. © 2018 Wiley Periodicals, Inc.

Bias and Bias Correction in Multi-Site Instrumental Variables Analysis of Heterogeneous Mediator Effects

ERIC Educational Resources Information Center

Reardon, Sean F.; Unlu, Faith; Zhu, Pei; Bloom, Howard

2013-01-01

We explore the use of instrumental variables (IV) analysis with a multi-site randomized trial to estimate the effect of a mediating variable on an outcome in cases where it can be assumed that the observed mediator is the only mechanism linking treatment assignment to outcomes, as assumption known in the instrumental variables literature as the…

Predictors of burnout syndrome in intensive care nurses.

PubMed

Vasconcelos, Eduardo Motta de; Martino, Milva Maria Figueiredo De

2018-06-07

To identify the prevalence and analyse the existence of predictors of burnout syndrome in intensive care nurses. The quantitative, descriptive, cross sectional study with 91 intensive care nurses. Two instruments were used to collect data in July 2014: a sociodemographic form and the Maslach Burnout Inventory - Human Services Survey. Pearson's Chi-Square test or Fisher's exact test were applied to verify the association between the occurrence of burnout and the categorical variables. Burnout affected 14.3% of the sample. Of the studied variables, only the duration of holidays had a significant association with the occurrence of burnout (p = 0034/OR = 3.92). The prevalence of burnout in the nurses was 14.3%. Duration of the holidays was the only variable that showed a significant association with the occurrence of burnout.

Validation of a Theory of Planned Behavior-Based Questionnaire to Examine Factors Associated With Milk Expression.

PubMed

Bai, Yeon K; Dinour, Lauren M

2017-11-01

A proper assessment of multidimensional needs for breastfeeding mothers in various settings is crucial to facilitate and support breastfeeding and its exclusivity. The theory of planned behavior (TPB) has been used frequently to measure factors associated with breastfeeding. Full utility of the TPB requires accurate measurement of theory constructs. Research aim: This study aimed to develop and confirm the psychometric properties of an instrument, Milk Expression on Campus, based on the TPB and to establish the reliability and validity of the instrument. In spring 2015, 218 breastfeeding (current or in the recent past) employees and students at one university campus in northern New Jersey completed the online questionnaire containing demography and theory-based items. Internal consistency (α) and split-half reliability ( r) tests and factor analyses established and confirmed the reliability and construct validity of this instrument. Milk Expression on Campus showed strong and significant reliabilities as a full scale (α = .78, r = .74, p < .001) and theory construct subscales. Validity was confirmed as psychometric properties corresponded to the factors extracted from the scale. Four factors extracted from the direct construct subscales accounted for 79.49% of the total variability. Four distinct factors from the indirect construct subscales accounted for 73.68% of the total variability. Milk Expression on Campus can serve as a model TPB-based instrument to examine factors associated with women's milk expression behavior. The utility of this instrument extends to designing effective promotion programs to foster breastfeeding and milk expression behaviors in diverse settings.

Serum titanium, niobium and aluminium levels two years following instrumented spinal fusion in children: does implant surface area predict serum metal ion levels?

PubMed

Cundy, Thomas P; Cundy, William J; Antoniou, Georgia; Sutherland, Leanne M; Freeman, Brian J C; Cundy, Peter J

2014-11-01

Measurement of serum metal ion levels is used to determine systemic exposure to implant-derived metal debris that may be generated by processes of wear and corrosion. The aim of this study is to investigate predictors of serum metal ion levels in children undergoing instrumented spinal arthrodesis using a titanium alloy, focusing on implant characteristics and instrumentation construct design variables. This prospective longitudinal cohort study involved 33 children. Serum samples were obtained preoperatively:and at five defined interval periods over the first:two post-operative years. Samples were analysed using high resolution:inductively coupled plasma mass spectrometry to measure titanium, niobium and aluminium concentrations. Instrumentation characteristics were catalogued and construct surface area (SA) measurements calculated using an implant-specific software algorithm tool. Significantly elevated levels of serum titanium and niobium were observed (p< 0.0001), with >95 % of post-operative levels abnormally elevated. Significant predictors of serum titanium and niobium levels included time since surgery, surgical procedure (posterior or anterior fusion), number of levels fused, number of pedicle screws inserted, total rod length, total metal SA, total exposed metal SA and total metal-on-metal SA. All significant instrumentation variables were highly correlated. There is a strong relationship between implant SA and both serum titanium and niobium levels. The direct clinical implications of these findings for patients are uncertain, but remain of concern. Surgeons should be aware of the strong correlation between implant surface area of the chosen construct and the subsequent serum metal ion levels.

A reply to Zigler and Seitz.

PubMed

Neman, R

1975-03-01

The Zigler and Seitz (1975) critique was carefully examined with respect to the conclusions of the Neman et al. (1975) study. Particular attention was given to the following questions: (a) did experimenter bias or commitment account for the results, (b) were unreliable and invalid psychometric instruments used, (c) were the statistical analyses insufficient or incorrect, (d) did the results reflect no more than the operation of chance, and (e) were the results biased by artifactually inflated profile scores. Experimenter bias and commitment were shown to be insufficient to account for the results; a further review of Buros (1972) showed that there was no need for apprehension about the testing instruments; the statistical analyses were shown to exceed prevailing standards for research reporting; the results were shown to reflect valid findings at the .05 probability level; and the Neman et al. (1975) results for the profile measure were equally significant using either "raw" neurological scores or "scales" neurological age scores. Zigler, Seitz, and I agreed on the needs for (a) using multivariate analyses, where applicable, in studies having more than one dependent variable; (b) defining the population for which sensorimotor training procedures may be appropriately prescribed; and (c) validating the profile measure as a tool to assess neurological disorganization.

Micro-CT analyses of apical enlargement and molar root canal complexity.

PubMed

Markvart, M; Darvann, T A; Larsen, P; Dalstra, M; Kreiborg, S; Bjørndal, L

2012-03-01

To compare the effectiveness of two rotary hybrid instrumentation techniques with focus on apical enlargement in molar teeth and to quantify and visualize spatial details of instrumentation efficacy in root canals of different complexity. Maxillary and mandibular molar teeth were scanned using X-ray microcomputed tomography. Root canals were prepared using either a GT/Profile protocol or a RaCe/NiTi protocol. Variables used for evaluation were the following: distance between root canal surfaces before and after preparation (distance after preparation, DAP), percentage of root canal area remaining unprepared and increase in canal volume after preparation. Root canals were classified according to size and complexity, and consequences of unprepared portions of narrow root canals and intraradicular connections/isthmuses were included in the analyses. One- and two-way anova were used in the statistical analyses. No difference was found between the two techniques: DAP(apical-third) (P = 0.590), area unprepared(apical-third) (P = 0.126) and volume increase(apical-third) (P = 0.821). Unprepared root canal area became larger in relation to root canal size and complexity, irrespective of the technique used. Percentage of root canal area remaining unprepared was significantly lower in small root canals and complex systems compared to large root canals. The isthmus area per se contributed with a mean of 17.6%, and with a mean of 25.7%, when a narrow root canal remained unprepared. The addition of isthmuses did not significantly alter the ratio of instrumented to unprepared areas at total root canal level. Distal and palatal root canals had the highest level of unprepared area irrespective of the two instrumentation techniques examined. © 2011 International Endodontic Journal.

Poverty and Child Development: A Longitudinal Study of the Impact of the Earned Income Tax Credit.

PubMed

Hamad, Rita; Rehkopf, David H

2016-05-01

Although adverse socioeconomic conditions are correlated with worse child health and development, the effects of poverty-alleviation policies are less understood. We examined the associations of the Earned Income Tax Credit (EITC) on child development and used an instrumental variable approach to estimate the potential impacts of income. We used data from the US National Longitudinal Survey of Youth (n = 8,186) during 1986-2000 to examine effects on the Behavioral Problems Index (BPI) and Home Observation Measurement of the Environment inventory (HOME) scores. We conducted 2 analyses. In the first, we used multivariate linear regressions with child-level fixed effects to examine the association of EITC payment size with BPI and HOME scores; in the second, we used EITC payment size as an instrument to estimate the associations of income with BPI and HOME scores. In linear regression models, higher EITC payments were associated with improved short-term BPI scores (per $1,000, β = -0.57; P = 0.04). In instrumental variable analyses, higher income was associated with improved short-term BPI scores (per $1,000, β = -0.47; P = 0.01) and medium-term HOME scores (per $1,000, β = 0.64; P = 0.02). Our results suggest that both EITC benefits and higher income are associated with modest but meaningful improvements in child development. These findings provide valuable information for health researchers and policymakers for improving child health and development. © The Author 2016. 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.

Compliance-Effect Correlation Bias in Instrumental Variables Estimators

ERIC Educational Resources Information Center

Reardon, Sean F.

2010-01-01

Instrumental variable estimators hold the promise of enabling researchers to estimate the effects of educational treatments that are not (or cannot be) randomly assigned but that may be affected by randomly assigned interventions. Examples of the use of instrumental variables in such cases are increasingly common in educational and social science…

Spatial Variability of Trace Gases During DISCOVER-AQ: Planning for Geostationary Observations of Atmospheric Composition

NASA Technical Reports Server (NTRS)

Follette-Cook, Melanie B.; Pickering, K.; Crawford, J.; Appel, W.; Diskin, G.; Fried, A.; Loughner, C.; Pfister, G.; Weinheimer, A.

2015-01-01

Results from an in-depth analysis of trace gas variability in MD indicated that the variability in this region was large enough to be observable by a TEMPO-like instrument. The variability observed in MD is relatively similar to the other three campaigns with a few exceptions: CO variability in CA was much higher than in the other regions; HCHO variability in CA and CO was much lower; MD showed the lowest variability in NO2All model simulations do a reasonable job simulating O3 variability. For CO, the CACO simulations largely under over estimate the variability in the observations. The variability in HCHO is underestimated for every campaign. NO2 variability is slightly overestimated in MD, more so in CO. The TX simulation underestimates the variability in each trace gas. This is most likely due to missing emissions sources (C. Loughner, manuscript in preparation).Future Work: Where reasonable, we will use these model outputs to further explore the resolvability from space of these key trace gases using analyses of tropospheric column amounts relative to satellite precision requirements, similar to Follette-Cook et al. (2015).

Satellite-based Analysis of CO Variability over the Amazon Basin

NASA Astrophysics Data System (ADS)

Deeter, M. N.; Emmons, L. K.; Martinez-Alonso, S.; Tilmes, S.; Wiedinmyer, C.

2017-12-01

Pyrogenic emissions from the Amazon Basin exert significant influence on both climate and air quality but are highly variable from year to year. The ability of models to simulate the impact of biomass burning emissions on downstream atmospheric concentrations depends on (1) the quality of surface flux estimates (i.e., emissions inventories), (2) model dynamics (e.g., horizontal winds, large-scale convection and mixing) and (3) the representation of atmospheric chemical processes. With an atmospheric lifetime of a few months, carbon monoxide (CO) is a commonly used diagnostic for biomass burning. CO products are available from several satellite instruments and allow analyses of CO variability over extended regions such as the Amazon Basin with useful spatial and temporal sampling characteristics. The MOPITT ('Measurements of Pollution in the Troposphere') instrument was launched on the NASA Terra platform near the end of 1999 and is still operational. MOPITT is uniquely capable of measuring tropospheric CO concentrations using both thermal-infrared and near-infrared observations, resulting in the ability to independently retrieve lower- and upper-troposphere CO concentrations. We exploit the 18-year MOPITT record and related datasets to analyze the variability of CO over the Amazon Basin and evaluate simulations performed with the CAM-chem chemical transport model. We demonstrate that observed differences between MOPITT observations and model simulations provide important clues regarding emissions inventories, convective mixing and long-range transport.

A Polychoric Instrumental Variable (PIV) Estimator for Structural Equation Models with Categorical Variables

ERIC Educational Resources Information Center

Bollen, Kenneth A.; Maydeu-Olivares, Albert

2007-01-01

This paper presents a new polychoric instrumental variable (PIV) estimator to use in structural equation models (SEMs) with categorical observed variables. The PIV estimator is a generalization of Bollen's (Psychometrika 61:109-121, 1996) 2SLS/IV estimator for continuous variables to categorical endogenous variables. We derive the PIV estimator…

The Choice of Screening Instrument Matters: The Case of Problematic Cannabis Use Screening in Spanish Population of Adolescents

PubMed Central

Domingo-Salvany, Antónia; Barrio Anta, Gregorio; Sánchez Mañez, Amparo; Llorens Aleixandre, Noelia; Brime Beteta, Begoña; Vicente, Julián

2013-01-01

The aim of this study was to examine the feasibility of problem cannabis use screening instruments administration within wide school surveys, their psychometric properties, overlaps, and relationships with other variables. Students from 7 Spanish regions, aged 14–18, who attended secondary schools were sampled by two-stage cluster sampling (net sample 14,589). Standardized, anonymous questionnaire including DSM-IV cannabis abuse criteria, Cannabis Abuse Screening Test (CAST), and Severity of Dependence Scale (SDS) was self-completed with paper and pencil in the selected classrooms. Data was analysed using classical psychometric theory, bivariate tests, and multinomial logistic regression analysis. Not responding to instruments' items (10.5–12.3%) was associated with reporting less frequent cannabis use. The instruments overlapped partially, with 16.1% of positives being positive on all three. SDS was more likely to identify younger users with lower frequency of use who thought habitual cannabis use posed a considerable problem. CAST positivity was associated with frequent cannabis use and related problems. It is feasible to use short psychometric scales in wide school surveys, but one must carefully choose the screening instrument, as different instruments identify different groups of users. These may correspond to different types of problematic cannabis use; however, measurement bias seems to play a role too. PMID:25969832

Reconstructing Past Seasonal to Multicentennial-Scale Variability in the NE Atlantic Ocean Using the Long-Lived Marine Bivalve Mollusk Glycymeris glycymeris

NASA Astrophysics Data System (ADS)

Reynolds, D. J.; Hall, I. R.; Slater, S. M.; Scourse, J. D.; Halloran, P. R.; Sayer, M. D. J.

2017-11-01

The lack of long-term, highly resolved (annual to subannual) and absolutely dated baseline records of marine variability extending beyond the instrumental period (last 50-100 years) hinders our ability to develop a comprehensive understanding of the role the ocean plays in the climate system. Specifically, without such records, it remains difficult to fully quantify the range of natural climate variability mediated by the ocean and to robustly attribute recent changes to anthropogenic or natural drivers. Here we present a 211 year (1799-2010 C.E.; all dates hereafter are Common Era) seawater temperature (SWT) reconstruction from the northeast Atlantic Ocean derived from absolutely dated, annually resolved, oxygen isotope ratios recorded in the shell carbonate (δ18Oshell) of the long-lived marine bivalve mollusk Glycymeris glycymeris. The annual record was calibrated using subannually resolved δ18Oshell values drilled from multiple shells covering the instrumental period. Calibration verification statistics and spatial correlation analyses indicate that the δ18Oshell record contains significant skill at reconstructing Northeast Atlantic Ocean mean summer SWT variability associated with changes in subpolar gyre dynamics and the North Atlantic Current. Reconciling differences between the δ18Oshell data and corresponding growth increment width chronology demonstrates that 68% of the variability in G. glycymeris shell growth can be explained by the combined influence of biological productivity and SWT variability. These data suggest that G. glycymeris can provide seasonal to multicentennial absolutely dated baseline records of past marine variability that will lead to the development of a quantitative understanding of the role the marine environment plays in the global climate system.

Measuring Food Brand Awareness in Australian Children: Development and Validation of a New Instrument

PubMed Central

Boyland, Emma; Bauman, Adrian E.

2015-01-01

Background Children’s exposure to food marketing is one environmental determinant of childhood obesity. Measuring the extent to which children are aware of food brands may be one way to estimate relative prior exposures to food marketing. This study aimed to develop and validate an Australian Brand Awareness Instrument (ABAI) to estimate children’s food brand awareness. Methods The ABAI incorporated 30 flashcards depicting food/drink logos and their corresponding products. An abbreviated version was also created using 12 flashcards (ABAI-a). The ABAI was presented to 60 primary school aged children (7-11yrs) attending two Australian after-school centres. A week later, the full-version was repeated on approximately half the sample (n=27) and the abbreviated-version was presented to the remaining half (n=30). The test-retest reliability of the ABAI was analysed using Intra-class correlation coefficients. The concordance of the ABAI-a and full-version was assessed using Bland-Altman plots. The ‘nomological’ validity of the full tool was investigated by comparing children’s brand awareness with food marketing-related variables (e.g. television habits, intake of heavily promoted foods). Results Brand awareness increased with age (p<0.01) but was not significantly correlated with other variables. Bland-Altman analyses showed good agreement between the ABAI and ABAI-a. Reliability analyses revealed excellent agreement between the two administrations of the full-ABAI. Conclusions The ABAI was able to differentiate children’s varying levels of brand awareness. It was shown to be a valid and reliable tool and may allow quantification of brand awareness as a proxy measure for children’s prior food marketing exposure. PMID:26222624

The EPIC-MOS Particle-Induced Background Spectra

NASA Technical Reports Server (NTRS)

Kuntz, K. D.; Sowden, S. L.

2007-01-01

In order to analyse diffuse emission that fills the field of view, one must accurately characterize the instrumental backgrounds. For the XMM-Newton EPIC instrument these backgrounds include a temporally variable "quiescent" component. as well as the strongly variable soft proton contamination. We have characterized the spectral and spatial response of the EPIC detectors to these background components and have developed tools to remove these backgrounds from observations. The "quiescent" component was characterized using a combination of the filter-wheel-closed data and a database of unexposed-region data. The soft proton contamination was characterized by differencing images and spectra taken during flared and flare-free intervals. After application of our modeled backgrounds, the differences between independent observations of the same region of "blank sky" are consistent with the statistical uncertainties except when there is clear spectral evidence of solar wind charge exchange emission. Using a large sample of blank sky data, we show that strong magnetospheric SWCX emission requires elevated solar wind fluxes; observations through the densest part of the magnetosheath are not necessarily strongly contaminated with SWCX emission.

Censored Quantile Instrumental Variable Estimates of the Price Elasticity of Expenditure on Medical Care.

PubMed

Kowalski, Amanda

2016-01-02

Efforts to control medical care costs depend critically on how individuals respond to prices. I estimate the price elasticity of expenditure on medical care using a censored quantile instrumental variable (CQIV) estimator. CQIV allows estimates to vary across the conditional expenditure distribution, relaxes traditional censored model assumptions, and addresses endogeneity with an instrumental variable. My instrumental variable strategy uses a family member's injury to induce variation in an individual's own price. Across the conditional deciles of the expenditure distribution, I find elasticities that vary from -0.76 to -1.49, which are an order of magnitude larger than previous estimates.

Variables associated with communicative participation in Parkinson's disease and its relationship to measures of health-related quality-of-life.

PubMed

McAuliffe, Megan J; Baylor, Carolyn R; Yorkston, Kathryn M

2017-08-01

Communication disorders associated with Parkinson's disease (PD) often lead to restricted participation in life roles, yet there is a limited understanding of influencing factors and few quantitative measurement tools available. This study aimed to identify variables associated with communicative participation in PD and to examine the relationship between the Communicative Participation Item Bank (CPIB) and existing health-related quality-of-life (HRQoL) measures. Self-report data from 378 participants with PD from the US and New Zealand were analysed. Data included responses to the CPIB, PD Questionnaire-8, sub-scales of the Global Health instrument from the Patient Reported Outcomes Measurement Information System (PROMIS) and additional self-report instruments. Greater perceived speech disorder, lower levels of speech usage, fatigue, cognitive and emotional problems and swallowing difficulties were associated with lower levels of communicative participation. Participants' age significantly influenced findings, interacting with country of residence, sex and speech usage. Scores on the CPIB were moderately correlated with HRQoL measures. Communicative participation in PD is complex and influenced by both demographic and disease-based variables, necessitating a broader view of the communicative experiences of those with PD. Measurement of communicative participation as a separate construct to existing HRQoL measures is recommended.

Intra-Aortic Balloon Pump Counterpulsation during Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction and Cardiogenic Shock: Insights from the British Columbia Cardiac Registry

PubMed Central

Iqbal, M. Bilal; Robinson, Simon D.; Ding, Lillian; Fung, Anthony; Aymong, Eve; Chan, Albert W.; Hodge, Steven; Della Siega, Anthony; Nadra, Imad J.

2016-01-01

Background Cardiogenic shock complicating ST-elevation myocardial infarction (STEMI) is associated with significant morbidity and mortality. In the primary percutaneous coronary intervention (PPCI) era, randomized trials have not shown a survival benefit with intra-aortic balloon pump (IABP) therapy. This differs to observational data which show a detrimental effect, potentially reflecting bias and confounding. Without robust and valid risk adjustment, findings from non-randomized studies may remain biased. Methods We compared long-term mortality following IABP therapy in patients with cardiogenic shock undergoing PPCI during 2008–2013 from the British Columbia Cardiac Registry. We addressed measured and unmeasured confounding using propensity score and instrumental variable methods. Results A total of 12,105 patients with STEMI were treated with PPCI during the study period. Of these, 700 patients (5.8%) had cardiogenic shock. Of the patients with cardiogenic shock, 255 patients (36%) received IABP therapy. Multivariable analyses identified IABP therapy to be associated with increased mortality up to 3 years (HR = 1.67, 95% CI:1.20–2.67, p<0.001). This association was lost in propensity-matched analyses (HR = 1.23, 95% CI: 0.84–1.80, p = 0.288). When addressing measured and unmeasured confounders, instrumental variable analyses demonstrated that IABP therapy was not associated with mortality at 3 years (Δ = 16.7%, 95% CI: -12.7%, 46.1%, p = 0.281). Subgroup analyses demonstrated IABP was associated with increased mortality in non-diabetics; patients not undergoing multivessel intervention; patients without renal disease and patients not having received prior thrombolysis. Conclusions In this observational analysis of patients with STEMI and cardiogenic shock, when adjusting for confounding, IABP therapy had a neutral effect with no association with long-term mortality. These findings differ to previously reported observational studies, but are in keeping with randomized trial data. PMID:26870950

Outcomes of Basic Versus Advanced Life Support for Out-of-Hospital Medical Emergencies.

PubMed

Sanghavi, Prachi; Jena, Anupam B; Newhouse, Joseph P; Zaslavsky, Alan M

2015-11-03

Most Medicare patients seeking emergency medical transport are treated by ambulance providers trained in advanced life support (ALS). Evidence supporting the superiority of ALS over basic life support (BLS) is limited, but some studies suggest ALS may harm patients. To compare outcomes after ALS and BLS in out-of-hospital medical emergencies. Observational study with adjustment for propensity score weights and instrumental variable analyses based on county-level variations in ALS use. Traditional Medicare. 20% random sample of Medicare beneficiaries from nonrural counties between 2006 and 2011 with major trauma, stroke, acute myocardial infarction (AMI), or respiratory failure. Neurologic functioning and survival to 30 days, 90 days, 1 year, and 2 years. Except in cases of AMI, patients showed superior unadjusted outcomes with BLS despite being older and having more comorbidities. In propensity score analyses, survival to 90 days among patients with trauma, stroke, and respiratory failure was higher with BLS than ALS (6.1 percentage points [95% CI, 5.4 to 6.8 percentage points] for trauma; 7.0 percentage points [CI, 6.2 to 7.7 percentage points] for stroke; and 3.7 percentage points [CI, 2.5 to 4.8 percentage points] for respiratory failure). Patients with AMI did not exhibit differences in survival at 30 days but had better survival at 90 days with ALS (1.0 percentage point [CI, 0.1 to 1.9 percentage points]). Neurologic functioning favored BLS for all diagnoses. Results from instrumental variable analyses were broadly consistent with propensity score analyses for trauma and stroke, showed no survival differences between BLS and ALS for respiratory failure, and showed better survival at all time points with BLS than ALS for patients with AMI. Only Medicare beneficiaries from nonrural counties were studied. Advanced life support is associated with substantially higher mortality for several acute medical emergencies than BLS. National Science Foundation, Agency for Healthcare Research and Quality, and National Institutes of Health.

A Persian version of the parental bonding instrument: factor structure and psychometric properties.

PubMed

Behzadi, Behnaz; Parker, Gordon

2015-02-28

The Parental Bonding Instrument (PBI) is a widely used self-report measure for quantifying key parenting styles as perceived by the child during its first 16 years. While its development study identified two key parental dimensions, subsequent studies have variably confirmed those two or argued for one or more additional parental constructs. We developed a Persian translation of the PBI and administered it to a sample of 340 high school students. The construct validity of the Persian PBI was examined by Exploratory Factor Analysis while Confirmatory Factor Analysis was used to identify the most adequate model. Analyses of the Persian PBI favored a four-factor model for both parental forms. The Persian PBI has a factorial structure consistent with constructs identified in western cultures, as well as high internal consistency and test-retest reliability. Multivariate analyses indicated significant differences between boys and girls across some factors. The PBI appears an acceptable and appropriate measure for quantifying parent-child bonding in Iranian samples. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Meat quality of lamb frozen stored up to 21 months: instrumental analyses on thawed meat during display.

PubMed

Muela, E; Monge, P; Sañudo, C; Campo, M M; Beltrán, J A

2015-04-01

The study analysed the effect of frozen storage duration (FSD: 0, 1, 9, 15 or 21 months) and display duration (DD: 0-24 h post-slaughter-, 3 and 6 days) in modified atmosphere packaging (MAP) on lamb quality. pH, colour, lipid oxidation, water holding capacity and instrumental texture were performed on Longissimus muscle in displayed fresh and thawed meat. FSD affected all the variables showing lower differences between fresh and 1 month storage than among them and longer FSD. Only cooking losses were not affected by DD in thawed meats. It was observed a general decrease in quality (lower redness and water holding capacity; higher yellowness and lipid oxidation) as FSD or DD increased and only texture was improved over DD being thawed meat more tender. In conclusion, lamb storage at -18°C should not exceed 1 month if thawed meat would be later displayed in MAP while meat would have an acceptable quality up to 21 months without subsequent display. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development and testing of an assessment instrument for the formative peer review of significant event analyses.

PubMed

McKay, J; Murphy, D J; Bowie, P; Schmuck, M-L; Lough, M; Eva, K W

2007-04-01

To establish the content validity and specific aspects of reliability for an assessment instrument designed to provide formative feedback to general practitioners (GPs) on the quality of their written analysis of a significant event. Content validity was quantified by application of a content validity index. Reliability testing involved a nested design, with 5 cells, each containing 4 assessors, rating 20 unique significant event analysis (SEA) reports (10 each from experienced GPs and GPs in training) using the assessment instrument. The variance attributable to each identified variable in the study was established by analysis of variance. Generalisability theory was then used to investigate the instrument's ability to discriminate among SEA reports. Content validity was demonstrated with at least 8 of 10 experts endorsing all 10 items of the assessment instrument. The overall G coefficient for the instrument was moderate to good (G>0.70), indicating that the instrument can provide consistent information on the standard achieved by the SEA report. There was moderate inter-rater reliability (G>0.60) when four raters were used to judge the quality of the SEA. This study provides the first steps towards validating an instrument that can provide educational feedback to GPs on their analysis of significant events. The key area identified to improve instrument reliability is variation among peer assessors in their assessment of SEA reports. Further validity and reliability testing should be carried out to provide GPs, their appraisers and contractual bodies with a validated feedback instrument on this aspect of the general practice quality agenda.

Examining the relationship between adolescent sexual risk-taking and perceptions of monitoring, communication, and parenting styles.

PubMed

Huebner, Angela J; Howell, Laurie W

2003-08-01

To examine the relationship between adolescent sexual risk-taking and perception of parental monitoring, frequency of parent-adolescent communication, and parenting style. The influences of gender, age, and ethnicity are also of interest. Data were collected from 7th-12th grade students in six rural, ethnically diverse school located in adjacent counties in a Southeastern state. A 174-item instrument assessed adolescent perceptions, behaviors and attitudes. Youth who had engaged in sexual intercourse (n = 1160) were included in the analyses. Logistic regression analyses were conducted to identify parenting practices that predicted high versus low-risk sex (defined by number of partners and use of condoms). Variables included parental monitoring, parent-adolescent communication, parenting style, parenting process interaction effects and interaction effects among these three parenting processes and gender, age and ethnicity. Analyses included frequencies, cross-tabulations and logistic regression. Parental monitoring, parental monitoring by parent-adolescent communication and parenting style by ethnicity were significant predictors of sexual risk-taking. No gender or age interactions were noted. Parental monitoring, parent-adolescent communication and parenting style are all important variables to consider when examining sexual risk-taking among adolescents.

Cognitive functioning and everyday problem solving in older adults.

PubMed

Burton, Catherine L; Strauss, Esther; Hultsch, David F; Hunter, Michael A

2006-09-01

The relationship between cognitive functioning and a performance-based measure of everyday problem-solving, the Everyday Problems Test (EPT), thought to index instrumental activities of daily living (IADL), was examined in 291 community-dwelling non-demented older adults. Performance on the EPT was found to vary according to age, cognitive status, and education. Hierarchical regression analyses revealed that, after adjusting for demographic and health variables, measures of cognitive functioning accounted for 23.6% of the variance in EPT performance. In particular, measures of global cognitive status, cognitive decline, speed of processing, executive functioning, episodic memory, and verbal ability were significant predictors of EPT performance. These findings suggest that cognitive functioning along with demographic variables are important determinants of everyday problem-solving.

Censored Quantile Instrumental Variable Estimates of the Price Elasticity of Expenditure on Medical Care

PubMed Central

Kowalski, Amanda

2015-01-01

Efforts to control medical care costs depend critically on how individuals respond to prices. I estimate the price elasticity of expenditure on medical care using a censored quantile instrumental variable (CQIV) estimator. CQIV allows estimates to vary across the conditional expenditure distribution, relaxes traditional censored model assumptions, and addresses endogeneity with an instrumental variable. My instrumental variable strategy uses a family member’s injury to induce variation in an individual’s own price. Across the conditional deciles of the expenditure distribution, I find elasticities that vary from −0.76 to −1.49, which are an order of magnitude larger than previous estimates. PMID:26977117

Physicians' prescribing preferences were a potential instrument for patients' actual prescriptions of antidepressants☆

PubMed Central

Davies, Neil M.; Gunnell, David; Thomas, Kyla H.; Metcalfe, Chris; Windmeijer, Frank; Martin, Richard M.

2013-01-01

Objectives To investigate whether physicians' prescribing preferences were valid instrumental variables for the antidepressant prescriptions they issued to their patients. Study Design and Setting We investigated whether physicians' previous prescriptions of (1) tricyclic antidepressants (TCAs) vs. selective serotonin reuptake inhibitors (SSRIs) and (2) paroxetine vs. other SSRIs were valid instruments. We investigated whether the instrumental variable assumptions are likely to hold and whether TCAs (vs. SSRIs) were associated with hospital admission for self-harm or death by suicide using both conventional and instrumental variable regressions. The setting for the study was general practices in the United Kingdom. Results Prior prescriptions were strongly associated with actual prescriptions: physicians who previously prescribed TCAs were 14.9 percentage points (95% confidence interval [CI], 14.4, 15.4) more likely to prescribe TCAs, and those who previously prescribed paroxetine were 27.7 percentage points (95% CI, 26.7, 28.8) more likely to prescribe paroxetine, to their next patient. Physicians' previous prescriptions were less strongly associated with patients' baseline characteristics than actual prescriptions. We found no evidence that the estimated association of TCAs with self-harm/suicide using instrumental variable regression differed from conventional regression estimates (P-value = 0.45). Conclusion The main instrumental variable assumptions held, suggesting that physicians' prescribing preferences are valid instruments for evaluating the short-term effects of antidepressants. PMID:24075596

Potential sources of analytical bias and error in selected trace element data-quality analyses

USGS Publications Warehouse

Paul, Angela P.; Garbarino, John R.; Olsen, Lisa D.; Rosen, Michael R.; Mebane, Christopher A.; Struzeski, Tedmund M.

2016-09-28

Potential sources of analytical bias and error associated with laboratory analyses for selected trace elements where concentrations were greater in filtered samples than in paired unfiltered samples were evaluated by U.S. Geological Survey (USGS) Water Quality Specialists in collaboration with the USGS National Water Quality Laboratory (NWQL) and the Branch of Quality Systems (BQS).Causes for trace-element concentrations in filtered samples to exceed those in associated unfiltered samples have been attributed to variability in analytical measurements, analytical bias, sample contamination either in the field or laboratory, and (or) sample-matrix chemistry. These issues have not only been attributed to data generated by the USGS NWQL but have been observed in data generated by other laboratories. This study continues the evaluation of potential analytical bias and error resulting from matrix chemistry and instrument variability by evaluating the performance of seven selected trace elements in paired filtered and unfiltered surface-water and groundwater samples collected from 23 sampling sites of varying chemistries from six States, matrix spike recoveries, and standard reference materials.Filtered and unfiltered samples have been routinely analyzed on separate inductively coupled plasma-mass spectrometry instruments. Unfiltered samples are treated with hydrochloric acid (HCl) during an in-bottle digestion procedure; filtered samples are not routinely treated with HCl as part of the laboratory analytical procedure. To evaluate the influence of HCl on different sample matrices, an aliquot of the filtered samples was treated with HCl. The addition of HCl did little to differentiate the analytical results between filtered samples treated with HCl from those samples left untreated; however, there was a small, but noticeable, decrease in the number of instances where a particular trace-element concentration was greater in a filtered sample than in the associated unfiltered sample for all trace elements except selenium. Accounting for the small dilution effect (2 percent) from the addition of HCl, as required for the in-bottle digestion procedure for unfiltered samples, may be one step toward decreasing the number of instances where trace-element concentrations are greater in filtered samples than in paired unfiltered samples.The laboratory analyses of arsenic, cadmium, lead, and zinc did not appear to be influenced by instrument biases. These trace elements showed similar results on both instruments used to analyze filtered and unfiltered samples. The results for aluminum and molybdenum tended to be higher on the instrument designated to analyze unfiltered samples; the results for selenium tended to be lower. The matrices used to prepare calibration standards were different for the two instruments. The instrument designated for the analysis of unfiltered samples was calibrated using standards prepared in a nitric:hydrochloric acid (HNO3:HCl) matrix. The instrument designated for the analysis of filtered samples was calibrated using standards prepared in a matrix acidified only with HNO3. Matrix chemistry may have influenced the responses of aluminum, molybdenum, and selenium on the two instruments. The best analytical practice is to calibrate instruments using calibration standards prepared in matrices that reasonably match those of the samples being analyzed.Filtered and unfiltered samples were spiked over a range of trace-element concentrations from less than 1 to 58 times ambient concentrations. The greater the magnitude of the trace-element spike concentration relative to the ambient concentration, the greater the likelihood spike recoveries will be within data control guidelines (80–120 percent). Greater variability in spike recoveries occurred when trace elements were spiked at concentrations less than 10 times the ambient concentration. Spike recoveries that were considerably lower than 90 percent often were associated with spiked concentrations substantially lower than what was present in the ambient sample. Because the main purpose of spiking natural water samples with known quantities of a particular analyte is to assess possible matrix effects on analytical results, the results of this study stress the importance of spiking samples at concentrations that are reasonably close to what is expected but sufficiently high to exceed analytical variability. Generally, differences in spike recovery results between paired filtered and unfiltered samples were minimal when samples were analyzed on the same instrument.Analytical results for trace-element concentrations in ambient filtered and unfiltered samples greater than 10 and 40 μg/L, respectively, were within the data-quality objective for precision of ±25 percent. Ambient trace-element concentrations in filtered samples greater than the long-term method detection limits but less than 10 μg/L failed to meet the data-quality objective for precision for at least one trace element in about 54 percent of the samples. Similarly, trace-element concentrations in unfiltered samples greater than the long-term method detection limits but less than 40 μg/L failed to meet this data-quality objective for at least one trace-element analysis in about 58 percent of the samples. Although, aluminum and zinc were particularly problematic, limited re-analyses of filtered and unfiltered samples appeared to improve otherwise failed analytical precision.The evaluation of analytical bias using standard reference materials indicate a slight low bias for results for arsenic, cadmium, selenium, and zinc. Aluminum and molybdenum show signs of high bias. There was no observed bias, as determined using the standard reference materials, during the analysis of lead.

Instrumentation Failure after Partial Corpectomy with Instrumentation of a Metastatic Spine

PubMed Central

Park, Sung Bae; Kim, Ki Jeong; Han, Sanghyun; Oh, Sohee; Kim, Chi Heon; Chung, Chun Kee

2018-01-01

Objective To identify the perioperative factors associated with instrument failure in patients undergoing a partial corpectomy with instrumentation (PCI) for spinal metastasis. Methods We assessed the one hundred twenty-four patients with who underwent PCI for a metastatic spine from 1987 to 2011. Outcome measure was the risk factor related to implantation failure. The preoperative factors analyzed were age, sex, ambulation, American Spinal Injury Association grade, bone mineral density, use of steroid, primary tumor site, number of vertebrae with metastasis, extra-bone metastasis, preoperative adjuvant chemotherapy, and preoperative spinal radiotherapy. The intraoperative factors were the number of fixed vertebrae, fixation in osteolytic vertebrae, bone grafting, and type of surgical approach. The postoperative factors included postoperative adjuvant chemotherapy and spinal radiotherapy. This study was supported by the National Research Foundation grant funded by government. There were no study-specific biases related to conflicts of interest. Results There were 15 instrumentation failures (15/124, 12.1%). Preoperative ambulatory status and primary tumor site were not significantly related to the development of implant failure. There were no significant associations between insertion of a bone graft into the partial corpectomy site and instrumentation failure. The preoperative and operative factors analyzed were not significantly related to instrumentation failure. In univariable and multivariable analyses, postoperative spinal radiotherapy was the only significant variable related to instrumentation failure (p=0.049 and 0.050, respectively). Conclusion When performing PCI in patients with spinal metastasis followed by postoperative spinal radiotherapy, the surgeon may consider the possibility of instrumentation failure and find other strategies for augmentation than the use of a bone graft for fusion. PMID:29631384

Instrumentation Failure after Partial Corpectomy with Instrumentation of a Metastatic Spine.

PubMed

Park, Sung Bae; Kim, Ki Jeong; Han, Sanghyun; Oh, Sohee; Kim, Chi Heon; Chung, Chun Kee

2018-05-01

To identify the perioperative factors associated with instrument failure in patients undergoing a partial corpectomy with instrumentation (PCI) for spinal metastasis. We assessed the one hundred twenty-four patients with who underwent PCI for a metastatic spine from 1987 to 2011. Outcome measure was the risk factor related to implantation failure. The preoperative factors analyzed were age, sex, ambulation, American Spinal Injury Association grade, bone mineral density, use of steroid, primary tumor site, number of vertebrae with metastasis, extra-bone metastasis, preoperative adjuvant chemotherapy, and preoperative spinal radiotherapy. The intraoperative factors were the number of fixed vertebrae, fixation in osteolytic vertebrae, bone grafting, and type of surgical approach. The postoperative factors included postoperative adjuvant chemotherapy and spinal radiotherapy. This study was supported by the National Research Foundation grant funded by government. There were no study-specific biases related to conflicts of interest. There were 15 instrumentation failures (15/124, 12.1%). Preoperative ambulatory status and primary tumor site were not significantly related to the development of implant failure. There were no significant associations between insertion of a bone graft into the partial corpectomy site and instrumentation failure. The preoperative and operative factors analyzed were not significantly related to instrumentation failure. In univariable and multivariable analyses, postoperative spinal radiotherapy was the only significant variable related to instrumentation failure ( p =0.049 and 0.050, respectively). When performing PCI in patients with spinal metastasis followed by postoperative spinal radiotherapy, the surgeon may consider the possibility of instrumentation failure and find other strategies for augmentation than the use of a bone graft for fusion.

Carcass yield and meat quality in broilers fed with canola meal.

PubMed

Gopinger, E; Xavier, E G; Lemes, J S; Moraes, P O; Elias, M C; Roll, V F B

2014-01-01

1. This study evaluated the effects of canola meal in broiler diets on carcass yield, carcass composition, and instrumental and sensory analyses of meat. 2. A total of 320 one-day-old Cobb broilers were used in a 35-d experiment using a completely randomised design with 5 concentrations of canola meal (0, 10, 20, 30 and 40%) as a dietary substitute for soya bean meal. 3. Polynomial regression at 5% significance was used to evaluate the effects of canola meal content. The following variables were measured: carcass yield, chemical composition of meat, and instrumental and sensorial analyses. 4. The results showed that carcass yield exhibited a quadratic effect that was crescent to the level of 18% of canola meal based on the weight of the leg and a quadratic increase at concentrations up to 8.4% of canola meal based on the weight of the chest. The yield of the chest exhibited a linear behaviour. 5. The chemical composition of leg meat, instrumental analysis of breast meat and sensory characteristics of the breast meat was not significantly affected by the inclusion of canola meal. The chemical composition of the breast meat exhibited an increased linear effect in terms of dry matter and ether extract and a decreased linear behaviour in terms of the ash content. 6. In conclusion, soya bean meal can be substituted with canola meal at concentrations up to 20% of the total diet without affecting carcass yield, composition of meat or the instrumental or sensory characteristics of the meat of broilers.

The clinical learning environment and supervision by staff nurses: developing the instrument.

PubMed

Saarikoski, Mikko; Leino-Kilpi, Helena

2002-03-01

The aims of this study were (1) to describe students' perceptions of the clinical learning environment and clinical supervision and (2) to develop an evaluation scale by using the empirical results of this study. The data were collected using the Clinical Learning Environment and Supervision instrument (CLES). The instrument was based on the literature review of earlier studies. The derived instrument was tested empirically in a study involving nurse students (N=416) from four nursing colleges in Finland. The results demonstrated that the method of supervision, the number of separate supervision sessions and the psychological content of supervisory contact within a positive ward atmosphere are the most important variables in the students' clinical learning. The results also suggest that ward managers can create the conditions of a positive ward culture and a positive attitude towards students and their learning needs. The construct validity of the instrument was analysed by using exploratory factor analysis. The analysis indicated that the most important factor in the students' clinical learning is the supervisory relationship. The two most important factors constituting a 'good' clinical learning environment are the management style of the ward manager and the premises of nursing on the ward. The results of the factor analysis support the theoretical construction of the clinical learning environment modelled by earlier empirical studies.

Multi-Epoch Mid-Infrared Interferometric Observations of the Oxygen-rich Mira Variable Star RR Aql with the VLTI/MIDI Instrument

DTIC Science & Technology

2011-01-01

VLTI/ MIDI Instrument I. Karovicova,1,3 M. Wittkowski,1 D. A. Boboltz,2 E. Fossat,3 K. Ohnaka,4 and M. Scholz5,6 1European Southern Observatory...the oxygen-rich Mira variable RR Aql at 13 epochs covering 4 pulsation cycles with the MIDI instrument at the VLTI. We modeled the observed data...Variable Star RR Aql with the VLTI/ MIDI Instrument 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e

The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease

PubMed Central

Gimeno-Santos, Elena; Raste, Yogini; Demeyer, Heleen; Louvaris, Zafeiris; de Jong, Corina; Rabinovich, Roberto A.; Hopkinson, Nicholas S.; Polkey, Michael I.; Vogiatzis, Ioannis; Tabberer, Maggie; Dobbels, Fabienne; Ivanoff, Nathalie; de Boer, Willem I.; van der Molen, Thys; Kulich, Karoly; Serra, Ignasi; Basagaña, Xavier; Troosters, Thierry; Puhan, Milo A.; Karlsson, Niklas

2015-01-01

No current patient-centred instrument captures all dimensions of physical activity in chronic obstructive pulmonary disease (COPD). Our objective was item reduction and initial validation of two instruments to measure physical activity in COPD. Physical activity was assessed in a 6-week, randomised, two-way cross-over, multicentre study using PROactive draft questionnaires (daily and clinical visit versions) and two activity monitors. Item reduction followed an iterative process including classical and Rasch model analyses, and input from patients and clinical experts. 236 COPD patients from five European centres were included. Results indicated the concept of physical activity in COPD had two domains, labelled “amount” and “difficulty”. After item reduction, the daily PROactive instrument comprised nine items and the clinical visit contained 14. Both demonstrated good model fit (person separation index >0.7). Confirmatory factor analysis supported the bidimensional structure. Both instruments had good internal consistency (Cronbach's α>0.8), test–retest reliability (intraclass correlation coefficient ≥0.9) and exhibited moderate-to-high correlations (r>0.6) with related constructs and very low correlations (r<0.3) with unrelated constructs, providing evidence for construct validity. Daily and clinical visit “PROactive physical activity in COPD” instruments are hybrid tools combining a short patient-reported outcome questionnaire and two activity monitor variables which provide simple, valid and reliable measures of physical activity in COPD patients. PMID:26022965

The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease.

PubMed

Gimeno-Santos, Elena; Raste, Yogini; Demeyer, Heleen; Louvaris, Zafeiris; de Jong, Corina; Rabinovich, Roberto A; Hopkinson, Nicholas S; Polkey, Michael I; Vogiatzis, Ioannis; Tabberer, Maggie; Dobbels, Fabienne; Ivanoff, Nathalie; de Boer, Willem I; van der Molen, Thys; Kulich, Karoly; Serra, Ignasi; Basagaña, Xavier; Troosters, Thierry; Puhan, Milo A; Karlsson, Niklas; Garcia-Aymerich, Judith

2015-10-01

No current patient-centred instrument captures all dimensions of physical activity in chronic obstructive pulmonary disease (COPD). Our objective was item reduction and initial validation of two instruments to measure physical activity in COPD.Physical activity was assessed in a 6-week, randomised, two-way cross-over, multicentre study using PROactive draft questionnaires (daily and clinical visit versions) and two activity monitors. Item reduction followed an iterative process including classical and Rasch model analyses, and input from patients and clinical experts.236 COPD patients from five European centres were included. Results indicated the concept of physical activity in COPD had two domains, labelled "amount" and "difficulty". After item reduction, the daily PROactive instrument comprised nine items and the clinical visit contained 14. Both demonstrated good model fit (person separation index >0.7). Confirmatory factor analysis supported the bidimensional structure. Both instruments had good internal consistency (Cronbach's α>0.8), test-retest reliability (intraclass correlation coefficient ≥0.9) and exhibited moderate-to-high correlations (r>0.6) with related constructs and very low correlations (r<0.3) with unrelated constructs, providing evidence for construct validity.Daily and clinical visit "PROactive physical activity in COPD" instruments are hybrid tools combining a short patient-reported outcome questionnaire and two activity monitor variables which provide simple, valid and reliable measures of physical activity in COPD patients. Copyright ©ERS 2015.

Microprobe studies of microtomed particles of white druse salts in shergottite EETA 79001

NASA Technical Reports Server (NTRS)

Lindstrom, D. J.

1991-01-01

The white druse material in Antarctic shergottite EETA 79001 has attracted much attention as a possible sample fo Martian aqueous deposits. Instrumental Neutron Activation Analysis (INAA) was used to determine trace element analyses of small particles of this material obtained by handpicking of likely grains from broken surfaces of the meteorite. Electron microprobe work was attempted on grain areas as large as 150x120 microns. Backscattered electron images show considerable variations in brightness, and botryoidal structures were observed. Microprobe analyses showed considerable variability both within single particles and between different particles. Microtomed surfaces of small selected particles were shown to be very useful in obtaining information on the texture and composition of rare lithologies like the white druse of EETA 79001. This material is clearly heterogeneous on all distance scales, so a large number of further analyses will be required to characterize it.

Meteorological conditions during the summer 1986 CITE 2 flight series

NASA Technical Reports Server (NTRS)

Shipham, Mark C.; Cahoon, Donald R.; Bachmeier, A. Scott

1990-01-01

An overview of meteorological conditions during the NASA Global Tropospheric Experiment/Chemical Instrumentation Testing and Evaluation (GTE/CITE 2) summer 1986 flight series is presented. Computer-generated isentropic trajectories are used to trace the history of air masses encountered along each aircraft flight path. The synoptic-scale wind fields are depicted based on Montgomery stream function analyses. Time series of aircraft-measured temperature, dew point, ozone, and altitude are shown to depict air mass variability. Observed differences between maritime tropical and maritime polar air masses are discussed.

Students' attitudes towards learning statistics

NASA Astrophysics Data System (ADS)

Ghulami, Hassan Rahnaward; Hamid, Mohd Rashid Ab; Zakaria, Roslinazairimah

2015-05-01

Positive attitude towards learning is vital in order to master the core content of the subject matters under study. This is unexceptional in learning statistics course especially at the university level. Therefore, this study investigates the students' attitude towards learning statistics. Six variables or constructs have been identified such as affect, cognitive competence, value, difficulty, interest, and effort. The instrument used for the study is questionnaire that was adopted and adapted from the reliable instrument of Survey of Attitudes towards Statistics(SATS©). This study is conducted to engineering undergraduate students in one of the university in the East Coast of Malaysia. The respondents consist of students who were taking the applied statistics course from different faculties. The results are analysed in terms of descriptive analysis and it contributes to the descriptive understanding of students' attitude towards the teaching and learning process of statistics.

Is Some Provider Advice on Smoking Cessation Better Than No Advice? An Instrumental Variable Analysis of the 2001 National Health Interview Survey

PubMed Central

Bao, Yuhua; Duan, Naihua; Fox, Sarah A

2006-01-01

Research Objective To estimate the effect of provider advice in routine clinical contacts on patient smoking cessation outcome. Data Source The Sample Adult File from the 2001 National Health Interview Survey. We focus on adult patients who were either current smokers or quit during the last 12 months and had some contact with the health care providers or facilities they most often went to for acute or preventive care. Study Design We estimate a joint model of self-reported smoking cessation and ever receiving advice to quit during medical visits in the past 12 months. Because providers are more likely to advise heavier smokers and/or patients already diagnosed with smoking-related conditions, we use provider advice for diet/nutrition and for physical activity reported by the same patient as instrumental variables for smoking cessation advice to mitigate the selection bias. We conduct additional analyses to examine the robustness of our estimate against the various scenarios by which the exclusion restriction of the instrumental variables may fail. Principal Findings Provider advice doubles the chances of success in (self-reported) smoking cessation by their patients. The probability of quitting by the end of the 12-month reference period increased from 6.9 to 14.7 percent, an effect that is of both statistical (p<.001) and clinical significance. Conclusions Provider advice delivered in routine practice settings has a substantial effect on the success rate of smoking cessation among smoking patients. Providing advice consistently to all smoking patients, compared with routine care, is more effective than doubling the federal excise tax and, in the longer run, likely to outperform some of the other tobacco control policies such as banning smoking in private workplaces. PMID:17116112

Aquatic habitat mapping with an acoustic doppler current profiler: Considerations for data quality

USGS Publications Warehouse

Gaeuman, David; Jacobson, Robert B.

2005-01-01

When mounted on a boat or other moving platform, acoustic Doppler current profilers (ADCPs) can be used to map a wide range of ecologically significant phenomena, including measures of fluid shear, turbulence, vorticity, and near-bed sediment transport. However, the instrument movement necessary for mapping applications can generate significant errors, many of which have not been inadequately described. This report focuses on the mechanisms by which moving-platform errors are generated, and quantifies their magnitudes under typical habitat-mapping conditions. The potential for velocity errors caused by mis-alignment of the instrument?s internal compass are widely recognized, but has not previously been quantified for moving instruments. Numerical analyses show that even relatively minor compass mis-alignments can produce significant velocity errors, depending on the ratio of absolute instrument velocity to the target velocity and on the relative directions of instrument and target motion. A maximum absolute instrument velocity of about 1 m/s is recommended for most mapping applications. Lower velocities are appropriate when making bed velocity measurements, an emerging application that makes use of ADCP bottom-tracking to measure the velocity of sediment particles at the bed. The mechanisms by which heterogeneities in the flow velocity field generate horizontal velocities errors are also quantified, and some basic limitations in the effectiveness of standard error-detection criteria for identifying these errors are described. Bed velocity measurements may be particularly vulnerable to errors caused by spatial variability in the sediment transport field.

An instrumental variable random-coefficients model for binary outcomes

PubMed Central

Chesher, Andrew; Rosen, Adam M

2014-01-01

In this paper, we study a random-coefficients model for a binary outcome. We allow for the possibility that some or even all of the explanatory variables are arbitrarily correlated with the random coefficients, thus permitting endogeneity. We assume the existence of observed instrumental variables Z that are jointly independent with the random coefficients, although we place no structure on the joint determination of the endogenous variable X and instruments Z, as would be required for a control function approach. The model fits within the spectrum of generalized instrumental variable models, and we thus apply identification results from our previous studies of such models to the present context, demonstrating their use. Specifically, we characterize the identified set for the distribution of random coefficients in the binary response model with endogeneity via a collection of conditional moment inequalities, and we investigate the structure of these sets by way of numerical illustration. PMID:25798048

Effect of a community intervention programme promoting social interactions on functional disability prevention for older adults: propensity score matching and instrumental variable analyses, JAGES Taketoyo study.

PubMed

Hikichi, Hiroyuki; Kondo, Naoki; Kondo, Katsunori; Aida, Jun; Takeda, Tokunori; Kawachi, Ichiro

2015-09-01

The efficacy of promoting social interactions to improve the health of older adults is not fully established due to residual confounding and selection bias. The government of Taketoyo town, Aichi Prefecture, Japan, developed a resident-centred community intervention programme called 'community salons', providing opportunities for social interactions among local older residents. To evaluate the impact of the programme, we conducted questionnaire surveys for all older residents of Taketoyo. We carried out a baseline survey in July 2006 (prior to the introduction of the programme) and assessed the onset of functional disability during March 2012. We analysed the data of 2421 older people. In addition to the standard Cox proportional hazard regression, we conducted Cox regression with propensity score matching (PSM) and an instrumental variable (IV) analysis, using the number of community salons within a radius of 350 m from the participant's home as an instrument. In the 5 years after the first salon was launched, the salon participants showed a 6.3% lower incidence of functional disability compared with non-participants. Even adjusting for sex, age, equivalent income, educational attainment, higher level activities of daily living and depression, the Cox adjusted HR for becoming disabled was 0.49 (95% CI 0.33 to 0.72). Similar results were observed using PSM (HR 0.52, 95% CI 0.33 to 0.83) and IV-Cox analysis (HR 0.50, 95% CI 0.34 to 0.74). A community health promotion programme focused on increasing social interactions among older adults may be effective in preventing the onset of disability. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Measuring the Sensitivity and Construct Validity of 6 Utility Instruments in 7 Disease Areas.

PubMed

Richardson, Jeff; Iezzi, Angelo; Khan, Munir A; Chen, Gang; Maxwell, Aimee

2016-02-01

Health services that affect quality of life (QoL) are increasingly evaluated using cost utility analyses (CUA). These commonly employ one of a small number of multiattribute utility instruments (MAUI) to assess the effects of the health service on utility. However, the MAUI differ significantly, and the choice of instrument may alter the outcome of an evaluation. The present article has 2 objectives: 1) to compare the results of 3 measures of the sensitivity of 6 MAUI and the results of 6 tests of construct validity in 7 disease areas and 2) to rank the MAUI by each of the test results in each disease area and by an overall composite index constructed from the tests. Patients and the general public were administered a battery of instruments, which included the 6 MAUI, disease-specific QoL instruments (DSI), and 6 other comparator instruments. In each disease area, instrument sensitivity was measured 3 ways: by the unadjusted mean difference in utility between public and patient groups, by the value of the effect size, and by the correlation between MAUI and DSI scores. Content and convergent validity were tested by comparison of MAUI utilities and scores from the 6 comparator instruments. These included 2 measures of health state preferences, measures of subjective well-being and capabilities, and generic measures of physical and mental QoL derived from the SF-36. The apparent sensitivity of instruments varied significantly with the measurement method and by disease area. Validation test results varied with the comparator instruments. Notwithstanding this variability, the 15D, AQoL-8D, and the SF-6D generally achieved better test results than the QWB and EQ-5D-5L. © The Author(s) 2015.

The accuracy of coin-operated breath analysers installed in licensed premises in the Perth metropolitan area.

PubMed

Hay, Greg; Cercarelli, L Rina

2004-04-01

To examine the accuracy of coin-operated breath analysers installed in licensed premises in the Perth metropolitan area. Two hundred licensed premises were contacted, which resulted in the location of 36 wall-mounted, coin-operated breath analysers. One instrument was removed prior to testing. These premises were then visited and the accuracy of the instruments was tested in situ using National Association of Testing Authorities Australia (NATA) certified 0.080% and 0.100% ethanol in nitrogen gas. The instruments were installed in the licensed premises as follows: 15 in the lounge bar, 10 in the main entrance, six in the public bar, two in the passageway to the toilets, and one in the male toilets. One licensed premise provided a handheld breath instrument. All instruments were accompanied by warning and operating instructions, but only five had any educational material. Only seven of the licensed premises had staff who had received any training in the operation of the wall-mounted instruments. Half of the licensees were unaware of the servicing requirements of the instruments. The testing found that only nine (25%) of the instruments provided acceptable results. The low level of accuracy of coin-operated breath analysers in the Perth metropolitan area is alarming and users should be informed of the potential inaccuracies. This paper, however, does not rule out that some wall-mounted breath analysing instruments may provide accurate results when properly maintained.

Health education literacy in patients with chronic musculoskeletal diseases: development of a new questionnaire and sociodemographic predictors.

PubMed

Farin, Erik; Ullrich, Antje; Nagl, Michaela

2013-12-01

It was our aim to develop a questionnaire for patients with chronic musculoskeletal diseases to self-report their health education literacy, to analyse the psychometric properties of the instrument and to test hypotheses concerning sociodemographic predictors of health education literacy. A total of 577 patients with chronic back pain or osteoarthritis who underwent inpatient rehabilitation were surveyed. The resulting 'HELP questionnaire' (health education literacy of patients with chronic musculoskeletal diseases) consists of 18 items and three scales (comprehension of medical information, applying medical information, communicative competence in provider interactions). The instrument's psychometric properties are good (Cronbach's alpha between 0.88 and 0.95, unidimensionality and Rasch model fit established). Our sample's average level of self-reported health education literacy is quite high. However, 20-30% of the patients admitted to having difficulty understanding important aspects of health education programmes (i.e. comprehending what medical information means in relation to their disease). The variance explained by sociodemographic and basic medical variables is small (4-8%). Greater effort is required to make health education programmes easier to understand. There is a need for more research on interindividual variability of complex aspects of health literacy.

Testing concordance of instrumental variable effects in generalized linear models with application to Mendelian randomization

PubMed Central

Dai, James Y.; Chan, Kwun Chuen Gary; Hsu, Li

2014-01-01

Instrumental variable regression is one way to overcome unmeasured confounding and estimate causal effect in observational studies. Built on structural mean models, there has been considerale work recently developed for consistent estimation of causal relative risk and causal odds ratio. Such models can sometimes suffer from identification issues for weak instruments. This hampered the applicability of Mendelian randomization analysis in genetic epidemiology. When there are multiple genetic variants available as instrumental variables, and causal effect is defined in a generalized linear model in the presence of unmeasured confounders, we propose to test concordance between instrumental variable effects on the intermediate exposure and instrumental variable effects on the disease outcome, as a means to test the causal effect. We show that a class of generalized least squares estimators provide valid and consistent tests of causality. For causal effect of a continuous exposure on a dichotomous outcome in logistic models, the proposed estimators are shown to be asymptotically conservative. When the disease outcome is rare, such estimators are consistent due to the log-linear approximation of the logistic function. Optimality of such estimators relative to the well-known two-stage least squares estimator and the double-logistic structural mean model is further discussed. PMID:24863158

Outcomes of Posterolateral Fusion with and without Instrumentation and of Interbody Fusion for Isthmic Spondylolisthesis: A Prospective Study.

PubMed

Endler, Peter; Ekman, Per; Möller, Hans; Gerdhem, Paul

2017-05-03

Various methods for the treatment of isthmic spondylolisthesis are available. The aim of this study was to compare outcomes after posterolateral fusion without instrumentation, posterolateral fusion with instrumentation, and interbody fusion. The Swedish Spine Register was used to identify 765 patients who had been operated on for isthmic spondylolisthesis and had at least preoperative and 2-year outcome data; 586 of them had longer follow-up (a mean of 6.9 years). The outcome measures were a global assessment of leg and back pain, the Oswestry Disability Index (ODI), the EuroQol-5 Dimensions (EQ-5D) Questionnaire, the Short Form-36 (SF-36), a visual analog scale (VAS) for back and leg pain, and satisfaction with treatment. Data on additional lumbar spine surgery was searched for in the register, with the mean duration of follow-up for this variable being 10.6 years after the index procedure. Statistical analyses were performed with analysis of covariance or competing-risks proportional hazards regression, adjusted for baseline differences in the studied variables, smoking, employment status, and level of fusion. Posterolateral fusion without instrumentation was performed in 102 patients; posterolateral fusion with instrumentation, in 452; and interbody fusion, in 211. At 1 year, improvement was reported in the global assessment for back pain by 54% of the patients who had posterolateral fusion without instrumentation, 68% of those treated with posterolateral fusion with instrumentation, and 70% of those treated with interbody fusion (p = 0.009). The VAS for back pain and reported satisfaction with treatment showed similar patterns (p = 0.003 and p = 0.017, respectively), whereas other outcomes did not differ among the treatment groups at 1 year. At 2 years, the global assessment for back pain indicated improvement in 57% of the patients who had undergone posterolateral fusion without instrumentation, 70% of those who had posterolateral fusion with instrumentation, and 71% of those treated with interbody fusion (p = 0.022). There were no significant outcome differences at the mean 6.9-year follow-up interval. There was an increased hazard ratio for additional lumbar spine surgery after interbody fusion (4.34; 95% confidence interval [CI] = 1.71 to 11.03) and posterolateral fusion with instrumentation (2.56; 95% CI = 1.02 to 6.42) compared with after posterolateral fusion without instrumentation (1.00; reference). Fusion with instrumentation, with or without interbody fusion, was associated with more improvement in back pain scores and higher satisfaction with treatment compared with fusion without instrumentation at 1 year, but the difference was attenuated with longer follow-up. Fusion with instrumentation was associated with a significantly higher risk of additional spine surgery. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A selective review of the first 20 years of instrumental variables models in health-services research and medicine.

PubMed

Cawley, John

2015-01-01

The method of instrumental variables (IV) is useful for estimating causal effects. Intuitively, it exploits exogenous variation in the treatment, sometimes called natural experiments or instruments. This study reviews the literature in health-services research and medical research that applies the method of instrumental variables, documents trends in its use, and offers examples of various types of instruments. A literature search of the PubMed and EconLit research databases for English-language journal articles published after 1990 yielded a total of 522 original research articles. Citations counts for each article were derived from the Web of Science. A selective review was conducted, with articles prioritized based on number of citations, validity and power of the instrument, and type of instrument. The average annual number of papers in health services research and medical research that apply the method of instrumental variables rose from 1.2 in 1991-1995 to 41.8 in 2006-2010. Commonly-used instruments (natural experiments) in health and medicine are relative distance to a medical care provider offering the treatment and the medical care provider's historic tendency to administer the treatment. Less common but still noteworthy instruments include randomization of treatment for reasons other than research, randomized encouragement to undertake the treatment, day of week of admission as an instrument for waiting time for surgery, and genes as an instrument for whether the respondent has a heritable condition. The use of the method of IV has increased dramatically in the past 20 years, and a wide range of instruments have been used. Applications of the method of IV have in several cases upended conventional wisdom that was based on correlations and led to important insights about health and healthcare. Future research should pursue new applications of existing instruments and search for new instruments that are powerful and valid.

Study on bending behaviour of nickel–titanium rotary endodontic instruments by analytical and numerical analyses

PubMed Central

Tsao, C C; Liou, J U; Wen, P H; Peng, C C; Liu, T S

2013-01-01

Aim To develop analytical models and analyse the stress distribution and flexibility of nickel–titanium (NiTi) instruments subject to bending forces. Methodology The analytical method was used to analyse the behaviours of NiTi instruments under bending forces. Two NiTi instruments (RaCe and Mani NRT) with different cross-sections and geometries were considered. Analytical results were derived using Euler–Bernoulli nonlinear differential equations that took into account the screw pitch variation of these NiTi instruments. In addition, the nonlinear deformation analysis based on the analytical model and the finite element nonlinear analysis was carried out. Numerical results are obtained by carrying out a finite element method. Results According to analytical results, the maximum curvature of the instrument occurs near the instrument tip. Results of the finite element analysis revealed that the position of maximum von Mises stress was near the instrument tip. Therefore, the proposed analytical model can be used to predict the position of maximum curvature in the instrument where fracture may occur. Finally, results of analytical and numerical models were compatible. Conclusion The proposed analytical model was validated by numerical results in analysing bending deformation of NiTi instruments. The analytical model is useful in the design and analysis of instruments. The proposed theoretical model is effective in studying the flexibility of NiTi instruments. Compared with the finite element method, the analytical model can deal conveniently and effectively with the subject of bending behaviour of rotary NiTi endodontic instruments. PMID:23173762

Parenting styles and eating disorders.

PubMed

Jáuregui Lobera, I; Bolaños Ríos, P; Garrido Casals, O

2011-10-01

The aim of the study was to analyse the parental bonding profiles in patients with eating disorders (ED), as well as the relationship among the different styles of parenting and some psychological and psychopathological variables. In addition, the association between the perceived parental bonding and different coping strategies was analysed. Perception of parenting styles was analysed in a sample of 70 ED patients. The Parental Bonding Instrument, Self-Esteem Scale of Rosenberg, Coping Strategies Inventory, State-Trait Anxiety Inventory, Beck Depression Inventory and Eating Disorders Inventory-2 were used. Kruskal-Wallis test (comparisons), Spearman correlation coefficients (association among different variables) and χ(2)-test (parental bonding profiles differences) were applied. The stereotyped style among ED patients is low care-high control during the first 16 years, and the same can be said about current styles of the mothers. Between 8.6% and 12.9% of the patients perceive their parents' styles as neglectful. The neglectful parenting is the style mainly involved in the specific ED symptoms as drive for thinness, body dissatisfaction and bulimia. In order to achieve a better balanced parents' role during the treatment, it would be necessary to improve the role of the mothers as caregivers, decreasing their role mainly based on the overprotection. © 2011 Blackwell Publishing.

Determining the Attitudes of Undergraduate Students Having Vocational Music Education towards Individual Instrument Course According to Different Variables

ERIC Educational Resources Information Center

Uluçay, Taner

2017-01-01

This study was carried out in order to determine attitudes of undergraduate students who studied music vocationally towards the individual instrument course according to the variables of grade, gender, individual instrument and graduated high school type. The research data were obtained from 102 undergraduate students studying in Erzincan…

Phonation Quotient in Women: A Measure of Vocal Efficiency Using Three Aerodynamic Instruments.

PubMed

Joshi, Ashwini; Watts, Christopher R

2017-03-01

The purpose of this study was to examine measures of vital capacity and phonation quotient across three age groups in women using three different aerodynamic instruments representing low-tech and high-tech options. This study has a prospective, repeated measures design. Fifteen women in each age group of 25-39 years, 40-59 years, and 60-79 years were assessed using maximum phonation time and vital capacity obtained from three aerodynamic instruments: a handheld analog windmill type spirometer, a handheld digital spirometer, and the Phonatory Aerodynamic System (PAS), Model 6600. Phonation quotient was calculated using vital capacity from each instrument. Analyses of variance were performed to test for main effects of the instruments and age on vital capacity and derived phonation quotient. Pearson product moment correlation was performed to assess measurement reliability (parallel forms) between the instruments. Regression equations, scatterplots, and coefficients of determination were also calculated. Statistically significant differences were found in vital capacity measures for the digital spirometer compared with the windmill-type spirometer and PAS across age groups. Strong positive correlations were present between all three instruments for both vital capacity and derived phonation quotient measurements. Measurement precision for the digital spirometer was lower than the windmill spirometer compared with the PAS. However, all three instruments had strong measurement reliability. Additionally, age did not have an effect on the measurement across instruments. These results are consistent with previous literature reporting data from male speakers and support the use of low-tech options for measurement of basic aerodynamic variables associated with voice production. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Instrumental variables estimation of exposure effects on a time-to-event endpoint using structural cumulative survival models.

PubMed

Martinussen, Torben; Vansteelandt, Stijn; Tchetgen Tchetgen, Eric J; Zucker, David M

2017-12-01

The use of instrumental variables for estimating the effect of an exposure on an outcome is popular in econometrics, and increasingly so in epidemiology. This increasing popularity may be attributed to the natural occurrence of instrumental variables in observational studies that incorporate elements of randomization, either by design or by nature (e.g., random inheritance of genes). Instrumental variables estimation of exposure effects is well established for continuous outcomes and to some extent for binary outcomes. It is, however, largely lacking for time-to-event outcomes because of complications due to censoring and survivorship bias. In this article, we make a novel proposal under a class of structural cumulative survival models which parameterize time-varying effects of a point exposure directly on the scale of the survival function; these models are essentially equivalent with a semi-parametric variant of the instrumental variables additive hazards model. We propose a class of recursive instrumental variable estimators for these exposure effects, and derive their large sample properties along with inferential tools. We examine the performance of the proposed method in simulation studies and illustrate it in a Mendelian randomization study to evaluate the effect of diabetes on mortality using data from the Health and Retirement Study. We further use the proposed method to investigate potential benefit from breast cancer screening on subsequent breast cancer mortality based on the HIP-study. © 2017, The International Biometric Society.

Rural Parents’ Perceived Stigma of Seeking Mental Health Services for their Children: Development and Evaluation of a New Instrument

PubMed Central

Williams, Stacey L.; Polaha, Jodi

2014-01-01

The purpose of this paper was to examine the validity of score interpretations of an instrument developed to measure parents’ perceptions of stigma about seeking mental health services for their children. The validity of the score interpretations of the instrument was tested in two studies. Study 1 examined confirmatory factor analysis (CFA) employing a split half approach, and construct and criterion validity using the entire sample of parents in rural Appalachia whose children were experiencing psychosocial concerns (N=347), while Study 2 further examined CFA, construct and criterion validity, as well as predictive validity of the scores on the new scale using a general sample of parents in rural Appalachia (N=184). Results of exploratory and confirmatory factor analyses revealed support for a two factor model of parents’ perceived stigma, which represented both self and public forms of stigma associated with seeking mental health services for their children, and correlated with existing measures of stigma and other psychosocial variables. Further, the new self and public stigma scale significantly predicted parents’ willingness to seek services for children. PMID:24749752

From nanoparticles to large aerosols: Ultrafast measurement methods for size and concentration

NASA Astrophysics Data System (ADS)

Keck, Lothar; Spielvogel, Jürgen; Grimm, Hans

2009-05-01

A major challenge in aerosol technology is the fast measurement of number size distributions with good accuracy and size resolution. The dedicated instruments are frequently based on particle charging and electric detection. Established fast systems, however, still feature a number of shortcomings. We have developed a new instrument that constitutes of a high flow Differential Mobility Analyser (high flow DMA) and a high sensitivity Faraday Cup Electrometer (FCE). The system enables variable flow rates of up to 150 lpm, and the scan time for size distribution can be shortened considerably due to the short residence time of the particles in the DMA. Three different electrodes can be employed in order to cover a large size range. First test results demonstrate that the scan time can be reduced to less than 1 s for small particles, and that the results from the fast scans feature no significant difference to the results from established slow method. The fields of application for the new instrument comprise the precise monitoring of fast processes with nanoparticles, including monitoring of engine exhaust in automotive research.

Influence of operator experience on canal preparation time when using the rotary Ni-Ti ProFile system in simulated curved canals.

PubMed

Mesgouez, C; Rilliard, F; Matossian, L; Nassiri, K; Mandel, E

2003-03-01

The aim of this study was to determine the influence of operator experience on the time needed for canal preparation when using a rotary nickel-titanium (Ni-Ti) system. A total of 100 simulated curved canals in resin blocks were used. Four operators prepared a total of 25 canals each. The operators included practitioners with prior experience of the preparation technique, and practitioners with no experience. The working length for each instrument was precisely predetermined. All canals were instrumented with rotary Ni-Ti ProFile Variable Taper Series 29 engine-driven instruments using a high-torque handpiece (Maillefer, Ballaigues, Switzerland). The time taken to prepare each canal was recorded. Significant differences between the operators were analysed using the Student's t-test and the Kruskall-Wallis and Dunn nonparametric tests. Comparison of canal preparation times demonstrated a statistically significant difference between the four operators (P < 0.001). In the inexperienced group, a significant linear regression between canal number and preparation time occurred. Time required for canal preparation was inversely related to operator experience.

Automated measurement and monitoring of bioprocesses: key elements of the M(3)C strategy.

PubMed

Sonnleitner, Bernhard

2013-01-01

The state-of-routine monitoring items established in the bioprocess industry as well as some important state-of-the-art methods are briefly described and the potential pitfalls discussed. Among those are physical and chemical variables such as temperature, pressure, weight, volume, mass and volumetric flow rates, pH, redox potential, gas partial pressures in the liquid and molar fractions in the gas phase, infrared spectral analysis of the liquid phase, and calorimetry over an entire reactor. Classical as well as new optical versions are addressed. Biomass and bio-activity monitoring (as opposed to "measurement") via turbidity, permittivity, in situ microscopy, and fluorescence are critically analyzed. Some new(er) instrumental analytical tools, interfaced to bioprocesses, are explained. Among those are chromatographic methods, mass spectrometry, flow and sequential injection analyses, field flow fractionation, capillary electrophoresis, and flow cytometry. This chapter surveys the principles of monitoring rather than compiling instruments.

Vertical profiles of ozone, carbon monoxide, and dew-point temperature obtained during GTE/CITE 1, October-November 1983. [Chemical Instrumentation Test and Evaluation

NASA Technical Reports Server (NTRS)

Fishman, Jack; Gregory, Gerald L.; Sachse, Glen W.; Beck, Sherwin M.; Hill, Gerald F.

1987-01-01

A set of 14 pairs of vertical profiles of ozone and carbon monoxide, obtained with fast-response instrumentation, is presented. Most of these profiles, which were measured in the remote troposphere, also have supporting fast-response dew-point temperature profiles. The data suggest that the continental boundary layer is a source of tropospheric ozone, even in October and November, when photochemical activity should be rather small. In general, the small-scale vertical variability between CO and O3 is in phase. At low latitudes this relationship defines levels in the atmosphere where midlatitude air is being transported to lower latitudes, since lower dew-point temperatures accompany these higher CO and O3 concentrations. A set of profiles which is suggestive of interhemispheric transport is also presented. Independent meteorological analyses support these interpretations.

The relationship between alexithymia and maladaptive perfectionism in eating disorders: a mediation moderation analysis methodology.

PubMed

Marsero, S; Ruggiero, G M; Scarone, S; Bertelli, S; Sassaroli, S

2011-09-01

This work aimed to explore the relationship between alexithymia and maladaptive perfectionism in the psychological process leading to eating disorders (ED). Forty-nine individuals with ED and 49 controls completed the Concern over Mistakes subscale of the Frost Multidimensional Perfectionism Scale, the Perfectionism subscale of the Eating Disorders Inventory, the total score of the Toronto Alexithymia Scale, and the Drive for Thinness, Bulimia, and Body Dissatisfaction subscales of the Eating Disorders Inventory. We tested a model in which alexythimia is the independent variable and perfectionism is the possible mediator or moderator. Analyses confirmed the assumed model. In addition, it emerged that perfectionism played a mediating or moderating role when measured by different instruments. This result suggested that different instruments measured subtly different aspects of the same construct. Results could suggest that alexithymia is a predisposing factor for perfectionism, which in turn may lead to the development of eating disorders.

Aeolian Dunes: New High-Resolution Archives of Past Wind-Intensity and -Direction

NASA Astrophysics Data System (ADS)

Lindhorst, S.; Betzler, C.

2017-12-01

The understanding of the long-term variability of local wind-fields is most relevant for calibrating climate models and for the prediction of the socio-economic consequences of climate change. Continuous instrumental-based weather observations go back less than two centuries; aeolian dunes, however, contain an archive of past wind-field fluctuations which is basically unread. We present new ways to reconstruct annual to seasonal changes of wind intensity and predominant wind direction from dune-sediment composition and -geometries based on ground-penetrating radar (GPR) data, grain-size analyses and different age-dating approaches. Resulting proxy-based data series on wind are validated against instrumental based weather observations. Our approach can be applied to both recent as well as fossil dunes. Potential applications include the validation of climate models, the reconstruction of past supra-regional wind systems and the monitoring of future shifts in the climate system.

Multitrait-Multimethod Analyses of Two Self-Concept Instruments.

ERIC Educational Resources Information Center

Marsh, Herbert W.; Smith, Ian D.

1982-01-01

The multidimensionality of self-concept and the use of factor analysis in the development of self-concept instruments are supported in multitrait-multimethod analyses of the Sears and Coopersmith instruments. Convergent validity and discriminate validity of subscales in factor analysis and multitrait-multimethod analysis of longitudinal data are…

Comparison of the Cytobrush®, dermatological curette and oral CDx® brush test as methods for obtaining samples of RNA for molecular analysis of oral cytology.

PubMed

Reboiras-López, M D; Pérez-Sayáns, M; Somoza-Martín, J M; Gayoso-Diz, P; Barros-Angueira, F; Gándara-Rey, J M; García-García, A

2012-06-01

Interest in oral exfoliative cytology has increased with the availability of molecular markers that may lead to the earlier diagnosis of oral squamous cell carcinoma. This research aims to compare the efficacy of three different instruments (Cytobrush, curette and Oral CDx brush) in providing adequate material for molecular analysis. One hundred and four cytological samples obtained from volunteer healthy subjects were analysed using all three instruments. The clinical and demographical variables under study were age, sex and smoking habits. The three instruments were compared for their ability to obtain adequate samples and for the amount of RNA obtained using quantitative real-time polymerase chain reaction (PCR-qRT) analysis of the Abelson (ABL) housekeeping gene. RNA of the ABL gene has been quantified by number of copies. Adequate samples were more likely to be obtained with a curette (90.6%) or Oral CDx (80.0%) than a Cytobrush (48.6%); P < 0.001. Similarly, the RNA quantification was 17.64 ± 21.10 with a curette, 16.04 ± 15.81 with Oral CDx and 6.82 ± 6.71 with a Cytobrush. There were statistically significant differences between the Cytobrush and curette (P = 0.008) and between the Cytobrush and OralCDx (P = 0.034). There was no difference according to the demographical variables. Oral exfoliative cytology is a simple, non-invasive technique that provides sufficient RNA to perform studies on gene expression. Although material was obtained with all three instruments, adequate samples were more likely to be obtained with the curette or Oral CDx than with a Cytobrush. The Oral CDx is a less aggressive instrument than the curette, so could be a useful tool in a clinical setting. © 2011 Blackwell Publishing Ltd.

A preliminary validation of a new measure of occupational health and safety.

PubMed

Cadieux, Jean; Roy, Mario; Desmarais, Lise

2006-01-01

This article describes the validation of an instrument designed to conduct an Occupational Health and Safety (OHS) self-diagnosis using workers observations of tangible facts and actions in the workplace. The instrument puts the emphasis on observable factors that make it possible to act proactively before accidents actually occur. Three companies were recruited from the printing sector in Québec based on their OHS performance (low, medium, and high), their interest in the project, and their availability. The master sample was composed of 269 people. Partial least squares (PLS) and vanishing tetrad analyses were used to study the behavior of the formative scales developed. The results indicate that partial revision of the instrument will be necessary to reach a fully satisfying level of validity. With regards to the statistical approach adopted, the use of a macro called CTA-SAS 2.0 developed by Bollen and Ting [Bollen, K.A., & Ting, K.-F. (1993). Confirmatory tetrad analysis. In P.V. Marsden (Ed.), Social methodology.Vol.23 (pp.147-176). Cambridge, MA: Blackwell, 23] has proven to be effective in providing a suitable statistical treatment of the latent formative variables on which our instrument's development is based. The results suggest that the instrument appears to be relatively robust and appropriate to diagnose OHS leading measures. In the long run, this instrument will make it possible for companies to draw a more refined picture of OHS evolution, even in the absence of occupational injuries.

Optimizing use of the structural chemical analyser (variable pressure FESEM-EDX Raman spectroscopy) on micro-size complex historical paintings characterization.

PubMed

Guerra, I; Cardell, C

2015-10-01

The novel Structural Chemical Analyser (hyphenated Raman spectroscopy and scanning electron microscopy equipped with an X-ray detector) is gaining popularity since it allows 3-D morphological studies and elemental, molecular, structural and electronic analyses of a single complex micro-sized sample without transfer between instruments. However, its full potential remains unexploited in painting heritage where simultaneous identification of inorganic and organic materials in paintings is critically yet unresolved. Despite benefits and drawbacks shown in literature, new challenges have to be faced analysing multifaceted paint specimens. SEM-Structural Chemical Analyser systems differ since they are fabricated ad hoc by request. As configuration influences the procedure to optimize analyses, likewise analytical protocols have to be designed ad hoc. This paper deals with the optimization of the analytical procedure of a Variable Pressure Field Emission scanning electron microscopy equipped with an X-ray detector Raman spectroscopy system to analyse historical paint samples. We address essential parameters, technical challenges and limitations raised from analysing paint stratigraphies, archaeological samples and loose pigments. We show that accurate data interpretation requires comprehensive knowledge of factors affecting Raman spectra. We tackled: (i) the in-FESEM-Raman spectroscopy analytical sequence, (ii) correlations between FESEM and Structural Chemical Analyser/laser analytical position, (iii) Raman signal intensity under different VP-FESEM vacuum modes, (iv) carbon deposition on samples under FESEM low-vacuum mode, (v) crystal nature and morphology, (vi) depth of focus and (vii) surface-enhanced Raman scattering effect. We recommend careful planning of analysis strategies prior to research which, although time consuming, guarantees reliable results. The ultimate goal of this paper is to help to guide future users of a FESEM-Structural Chemical Analyser system in order to increase applications. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Econometrics in outcomes research: the use of instrumental variables.

PubMed

Newhouse, J P; McClellan, M

1998-01-01

We describe an econometric technique, instrumental variables, that can be useful in estimating the effectiveness of clinical treatments in situations when a controlled trial has not or cannot be done. This technique relies upon the existence of one or more variables that induce substantial variation in the treatment variable but have no direct effect on the outcome variable of interest. We illustrate the use of the technique with an application to aggressive treatment of acute myocardial infarction in the elderly.

Synthesizing US Colonial Climate: Available Data and a "Proxy Adjustment" Method

NASA Astrophysics Data System (ADS)

Zalzal, K. S.; Munoz-Hernandez, A.; Arrigo, J. S.

2008-12-01

Climate and its variability is a primary driver of hydrologic systems. A paucity of instrumental data makes reconstructing seventeenth- and eighteenth-century climatic conditions along the Northeast corridor difficult, yet this information is necessary if we are to understand the conditions, changes and interactions society had with hydrosystems during this first period of permanent European settlement. For this period (approx. 1600- 1800) there are instrumental records for some regions such as annual temperature and precipitation data for Philadelphia beginning in 1738; Cambridge, Mass., from 1747-1776; and temperature for New Haven, Conn., from 1780 to 1800. There are also paleorecords, including tree-rings analyses and sediment core examinations of pollen and overwash deposits, and historical accounts of extreme weather events. Our analyses of these data show that correlating even the available data is less than straightforward. To produce a "best track" climate record, we introduce a new method of "paleoadjustment" as a means to characterize climate statistical properties as opposed to a strict reconstruction. Combining the instrumented record with the paleorecord, we estimated two sets of climate forcings to use in colonial hydrology study. The first utilized a recent instrumented record (1817-1917) from Baltimore, Md, statistically adjusted in 20-year windows to match trends in the paleorecords and anecdotal evidence from the Middle Colonies and Chesapeake Bay region. The second was a regression reconstruction for New England using climate indices developed from journal records and the Cambridge, Mass., instrumental record. The two climate reconstructions were used to compute the annual potential water yield over the 200-year period of interest. A comparison of these results allowed us to make preliminary conclusions regarding the effect of climate on hydrology during the colonial period. We contend that an understanding of historical hydrology will improve our ability to predict and react to changes in global water resources.

Blood gas analysis as a determinant of occupationally related disability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan, W.K.; Zaldivar, G.L.

1990-05-01

Arterial blood gas analysis is one of the criteria used by the Department of Labor to award total and permanent disability for coal workers' pneumoconiosis (Black Lung). We have observed that Black Lung claimants often undergo several blood gas analyses with widely differing results that sometimes range from complete normality to life-threatening hypoxemia in the same subject. We concluded that blood gas analysis in occupationally related disability determination is unreliable, in that quality control and instrumentation are variable; that severe hypoxemia is rare in coal workers' pneumoconiosis; and that such hypoxemia is nonspecific and correlates poorly with breathlessness.

Statistical methods for biodosimetry in the presence of both Berkson and classical measurement error

NASA Astrophysics Data System (ADS)

Miller, Austin

In radiation epidemiology, the true dose received by those exposed cannot be assessed directly. Physical dosimetry uses a deterministic function of the source term, distance and shielding to estimate dose. For the atomic bomb survivors, the physical dosimetry system is well established. The classical measurement errors plaguing the location and shielding inputs to the physical dosimetry system are well known. Adjusting for the associated biases requires an estimate for the classical measurement error variance, for which no data-driven estimate exists. In this case, an instrumental variable solution is the most viable option to overcome the classical measurement error indeterminacy. Biological indicators of dose may serve as instrumental variables. Specification of the biodosimeter dose-response model requires identification of the radiosensitivity variables, for which we develop statistical definitions and variables. More recently, researchers have recognized Berkson error in the dose estimates, introduced by averaging assumptions for many components in the physical dosimetry system. We show that Berkson error induces a bias in the instrumental variable estimate of the dose-response coefficient, and then address the estimation problem. This model is specified by developing an instrumental variable mixed measurement error likelihood function, which is then maximized using a Monte Carlo EM Algorithm. These methods produce dose estimates that incorporate information from both physical and biological indicators of dose, as well as the first instrumental variable based data-driven estimate for the classical measurement error variance.

MONET, HET and SALT and asteroseismological observations and theory in Göttingen

NASA Astrophysics Data System (ADS)

Schuh, S.; Hessman, F. V.; Dreizler, S.; Kollatschny, W.; Glatzel, W.

2007-06-01

The Göttingen stellar astrophysics group, headed by Stefan Dreizler, conducts research on extrasolar planets and their host stars, on lower-main sequence stars, and on evolved compact objects, in particular hot white dwarfs (including PG 1159 objects, magnetic WDs and cataclysmic variables), and subdwarf B stars. In addition to sophisticated NLTE spectral analyses of these stars, which draw on the extensive stellar atmosphere modelling experience of the group, we actively develop and apply a variety of photometric monitoring and time-resolved spectroscopic techniques to address time-dependent phenomena. With the new instrumentational developments described below, we plan to continue the study of variable white dwarfs (GW Vir, DB and ZZ Ceti variables) and in particular sdB EC 14026 and PG 1617 pulsators which already constitute a main focus, partly within the Whole Earth Telescope (WET/DARC), http://www.physics.udel.edu/~jlp/darc/) collaboration, on a new level. Additional interest is directed towards strange mode instabilities in Wolf Rayet stars.

Annually resolved North Atlantic marine climate over the last millennium

NASA Astrophysics Data System (ADS)

Reynolds, D. J.; Scourse, J. D.; Halloran, P. R.; Nederbragt, A. J.; Wanamaker, A. D.; Butler, P. G.; Richardson, C. A.; Heinemeier, J.; Eiríksson, J.; Knudsen, K. L.; Hall, I. R.

2016-12-01

Owing to the lack of absolutely dated oceanographic information before the modern instrumental period, there is currently significant debate as to the role played by North Atlantic Ocean dynamics in previous climate transitions (for example, Medieval Climate Anomaly-Little Ice Age, MCA-LIA). Here we present analyses of a millennial-length, annually resolved and absolutely dated marine δ18O archive. We interpret our record of oxygen isotope ratios from the shells of the long-lived marine bivalve Arctica islandica (δ18O-shell), from the North Icelandic shelf, in relation to seawater density variability and demonstrate that solar and volcanic forcing coupled with ocean circulation dynamics are key drivers of climate variability over the last millennium. During the pre-industrial period (AD 1000-1800) variability in the sub-polar North Atlantic leads changes in Northern Hemisphere surface air temperatures at multi-decadal timescales, indicating that North Atlantic Ocean dynamics played an active role in modulating the response of the atmosphere to solar and volcanic forcing.

Influence of Strategy of Learning and Achievement Motivation of Learning Achievement Class VIII Students of State Junior High School in District Blitar

ERIC Educational Resources Information Center

Ayundawati, Dyah; Setyosari, Punaji; Susilo, Herawati; Sihkabuden

2016-01-01

This study aims for know influence of problem-based learning strategies and achievement motivation on learning achievement. The method used in this research is quantitative method. The instrument used in this study is two fold instruments to measure moderator variable (achievement motivation) and instruments to measure the dependent variable (the…

Predictors of continued playing or singing--from childhood and adolescence to adult years.

PubMed

Theorell, T; Lennartsson, A-K; Madison, G; Mosing, M A; Ullén, F

2015-03-01

Many individuals play an instrument or sing during childhood, but they often stop later in life. This study surveyed adults representative of the Swedish population about musical activities during childhood. We asked 3820 adults (65% women) aged from 27 to 54 from the Swedish Twin Registry, who took extra music lessons to those provided at school, to fill in a web-based questionnaire. Factors analysed were the age they started studying music, the instrument they played, kind of teaching, institution and educational content, number of lessons and perceived characteristics of the lessons, the music environment during their childhood years and their preferred music genre. All variables were dichotomised. Factors strongly associated with continued playing or singing were male sex, young starting age, cultural family background, self-selected instrument, attending music classes and more than once a week, church-related or private education, pop, rock or classical music, playing by ear and improvisation. Several significant predictors determined whether a child continued to sing or play an instrument as an adult and many could be externally influenced, such as starting at a young age, taking music classes more than once a week, improvisation and the type of music they played. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Psychological Factors Associated with Development of TMD: the OPPERA Prospective Cohort Study

PubMed Central

Fillingim, Roger B.; Ohrbach, Richard; Greenspan, Joel D.; Knott, Charles; Diatchenko, Luda; Dubner, Ronald; Bair, Eric; Baraian, Cristina; Mack, Nicole; Slade, Gary D.; Maixner, William

2013-01-01

Case-control studies have consistently associated psychological factors with chronic pain in general and with temporomandibular disorders (TMD) specifically. However, only a handful of prospective studies has explored whether pre-existing psychological characteristics represent risk factors for first-onset TMD. The current findings derive from the prospective cohort study of the Orofacial Pain Prospective Evaluation and Risk Assessment (OPPERA) cooperative agreement. For this study, 3,263 TMD-free participants completed a battery of psychological instruments assessing general psychological adjustment and personality, affective distress, psychosocial stress, somatic symptoms, and pain coping and catastrophizing. Study participants were then followed prospectively for an average of 2.8 years to ascertain cases of first-onset of TMD, and 2,737 provided follow-up data and were considered in the analyses of TMD onset. In bivariate and demographically-adjusted analyses, several psychological variables predicted increased risk of first-onset TMD, including reported somatic symptoms, psychosocial stress, and affective distress. Principal component analysis of 26 psychological scores was used to identify latent constructs, revealing four components: stress and negative affectivity, global psychological and somatic symptoms, passive pain coping, and active pain coping. In multivariable analyses, global psychological and somatic symptoms emerged as the most robust risk factor for incident TMD. These findings provide evidence that measures of psychological functioning can predict first-onset of TMD. Future analyses in the OPPERA cohort will determine whether these psychological factors interact with other variables to increase risk for TMD onset and persistence. PMID:24275225

Trends and variability in the Hadley circulation over the Last Millennium from the proxy record

NASA Astrophysics Data System (ADS)

Horlick, K. A.; Noone, D.; Hakim, G. J.; Tardif, R.; Anderson, D. M.; Perkins, W. A.; Erb, M. P.; Steig, E. J.

2017-12-01

The Hadley circulation (HC) is the dominant atmospheric overturning circulation controlling variability in precipitation distribution in the tropics and subtropics, affecting agricultural production and water resource allocation, among other human civilizational dependencies. A lack of pre-instrumental data-model synthesis has been cited as the barrier to diagnostic analyses of the variability in width, position, and intensity of the HC and its response to anthropogenic forcing. We analyze the HC, and its rising limb associated with the Intertropical Convergence Zone (ITCZ), over the past 1000 years using the Last Millennium Reanalysis (LMR) (Hakim et al. 2016). The LMR systematically blends the dynamical constraints of climate models with a proxy network of coral, tree ring, and ice core records. It allows for a spatiotemporal analysis with robust uncertainty measures. A three dimensional analysis of LMR wind fields shows an centennial-scale circulatory trend over the last 200 years resembling that which might be expected from an ENSO and PDO-like structure. An observed aridification of both the central equatorial Pacific and the southwest United States, a strengthening of the east-west sea surface temperature and sea level pressure gradient in the equatorial Pacific, and a strengthening of the Walker overturning circulation suggest a more "La Niña-like" mean state. This is compared to our statistical description of the centennial-scale mean circulation and variability of the previous millennia. Similarly, precipitation and relative humidity trends suggest expansion and asymmetric meridional movement of the Hadley circulation as a result of asymmetric shifts in mean ITCZ position and intensity. These observations are then compared to free running model simulations, other instrumental reanalysis products, and late-Holocene aerosol, solar, and greenhouse forcings. This LMR reconstruction improves upon previous work by enabling a proxy-consistent, quantitative analysis of Hadley circulation intensity, structure, and variability rather than relying on simpler empirical reconstructions of variables like surface temperature alone.

Comparison of quartz crystallographic preferred orientations identified with optical fabric analysis, electron backscatter and neutron diffraction techniques.

PubMed

Hunter, N J R; Wilson, C J L; Luzin, V

2017-02-01

Three techniques are used to measure crystallographic preferred orientations (CPO) in a naturally deformed quartz mylonite: transmitted light cross-polarized microscopy using an automated fabric analyser, electron backscatter diffraction (EBSD) and neutron diffraction. Pole figure densities attributable to crystal-plastic deformation are variably recognizable across the techniques, particularly between fabric analyser and diffraction instruments. Although fabric analyser techniques offer rapid acquisition with minimal sample preparation, difficulties may exist when gathering orientation data parallel with the incident beam. Overall, we have found that EBSD and fabric analyser techniques are best suited for studying CPO distributions at the grain scale, where individual orientations can be linked to their source grain or nearest neighbours. Neutron diffraction serves as the best qualitative and quantitative means of estimating the bulk CPO, due to its three-dimensional data acquisition, greater sample area coverage, and larger sample size. However, a number of sampling methods can be applied to FA and EBSD data to make similar approximations. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Bias and Bias Correction in Multisite Instrumental Variables Analysis of Heterogeneous Mediator Effects

ERIC Educational Resources Information Center

Reardon, Sean F.; Unlu, Fatih; Zhu, Pei; Bloom, Howard S.

2014-01-01

We explore the use of instrumental variables (IV) analysis with a multisite randomized trial to estimate the effect of a mediating variable on an outcome in cases where it can be assumed that the observed mediator is the only mechanism linking treatment assignment to outcomes, an assumption known in the IV literature as the exclusion restriction.…

Regression Discontinuity for Causal Effect Estimation in Epidemiology.

PubMed

Oldenburg, Catherine E; Moscoe, Ellen; Bärnighausen, Till

Regression discontinuity analyses can generate estimates of the causal effects of an exposure when a continuously measured variable is used to assign the exposure to individuals based on a threshold rule. Individuals just above the threshold are expected to be similar in their distribution of measured and unmeasured baseline covariates to individuals just below the threshold, resulting in exchangeability. At the threshold exchangeability is guaranteed if there is random variation in the continuous assignment variable, e.g., due to random measurement error. Under exchangeability, causal effects can be identified at the threshold. The regression discontinuity intention-to-treat (RD-ITT) effect on an outcome can be estimated as the difference in the outcome between individuals just above (or below) versus just below (or above) the threshold. This effect is analogous to the ITT effect in a randomized controlled trial. Instrumental variable methods can be used to estimate the effect of exposure itself utilizing the threshold as the instrument. We review the recent epidemiologic literature reporting regression discontinuity studies and find that while regression discontinuity designs are beginning to be utilized in a variety of applications in epidemiology, they are still relatively rare, and analytic and reporting practices vary. Regression discontinuity has the potential to greatly contribute to the evidence base in epidemiology, in particular on the real-life and long-term effects and side-effects of medical treatments that are provided based on threshold rules - such as treatments for low birth weight, hypertension or diabetes.

Adjusted Analyses in Studies Addressing Therapy and Harm: Users' Guides to the Medical Literature.

PubMed

Agoritsas, Thomas; Merglen, Arnaud; Shah, Nilay D; O'Donnell, Martin; Guyatt, Gordon H

2017-02-21

Observational studies almost always have bias because prognostic factors are unequally distributed between patients exposed or not exposed to an intervention. The standard approach to dealing with this problem is adjusted or stratified analysis. Its principle is to use measurement of risk factors to create prognostically homogeneous groups and to combine effect estimates across groups.The purpose of this Users' Guide is to introduce readers to fundamental concepts underlying adjustment as a way of dealing with prognostic imbalance and to the basic principles and relative trustworthiness of various adjustment strategies.One alternative to the standard approach is propensity analysis, in which groups are matched according to the likelihood of membership in exposed or unexposed groups. Propensity methods can deal with multiple prognostic factors, even if there are relatively few patients having outcome events. However, propensity methods do not address other limitations of traditional adjustment: investigators may not have measured all relevant prognostic factors (or not accurately), and unknown factors may bias the results.A second approach, instrumental variable analysis, relies on identifying a variable associated with the likelihood of receiving the intervention but not associated with any prognostic factor or with the outcome (other than through the intervention); this could mimic randomization. However, as with assumptions of other adjustment approaches, it is never certain if an instrumental variable analysis eliminates bias.Although all these approaches can reduce the risk of bias in observational studies, none replace the balance of both known and unknown prognostic factors offered by randomization.

Comparative effectiveness research methodology using secondary data: A starting user's guide.

PubMed

Sun, Maxine; Lipsitz, Stuart R

2018-04-01

The use of secondary data, such as claims or administrative data, in comparative effectiveness research has grown tremendously in recent years. We believe that the current review can help investigators relying on secondary data to (1) gain insight into both the methodologies and statistical methods, (2) better understand the necessity of a rigorous planning before initiating a comparative effectiveness investigation, and (3) optimize the quality of their investigations. Specifically, we review concepts of adjusted analyses and confounders, methods of propensity score analyses, and instrumental variable analyses, risk prediction models (logistic and time-to-event), decision-curve analysis, as well as the interpretation of the P value and hypothesis testing. Overall, we hope that the current review article can help research investigators relying on secondary data to perform comparative effectiveness research better understand the necessity of a rigorous planning before study start, and gain better insight in the choice of statistical methods so as to optimize the quality of the research study. Copyright © 2017 Elsevier Inc. All rights reserved.

Quantifying measurement uncertainty and spatial variability in the context of model evaluation

NASA Astrophysics Data System (ADS)

Choukulkar, A.; Brewer, A.; Pichugina, Y. L.; Bonin, T.; Banta, R. M.; Sandberg, S.; Weickmann, A. M.; Djalalova, I.; McCaffrey, K.; Bianco, L.; Wilczak, J. M.; Newman, J. F.; Draxl, C.; Lundquist, J. K.; Wharton, S.; Olson, J.; Kenyon, J.; Marquis, M.

2017-12-01

In an effort to improve wind forecasts for the wind energy sector, the Department of Energy and the NOAA funded the second Wind Forecast Improvement Project (WFIP2). As part of the WFIP2 field campaign, a large suite of in-situ and remote sensing instrumentation was deployed to the Columbia River Gorge in Oregon and Washington from October 2015 - March 2017. The array of instrumentation deployed included 915-MHz wind profiling radars, sodars, wind- profiling lidars, and scanning lidars. The role of these instruments was to provide wind measurements at high spatial and temporal resolution for model evaluation and improvement of model physics. To properly determine model errors, the uncertainties in instrument-model comparisons need to be quantified accurately. These uncertainties arise from several factors such as measurement uncertainty, spatial variability, and interpolation of model output to instrument locations, to name a few. In this presentation, we will introduce a formalism to quantify measurement uncertainty and spatial variability. The accuracy of this formalism will be tested using existing datasets such as the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign. Finally, the uncertainties in wind measurement and the spatial variability estimates from the WFIP2 field campaign will be discussed to understand the challenges involved in model evaluation.

THAT INSTRUMENT IS LOUSY! IN SEARCH OF AGREEMENT WHEN USING INSTRUMENTAL VARIABLES ESTIMATION IN SUBSTANCE USE RESEARCH

PubMed Central

Popovici, Ioana

2009-01-01

SUMMARY The primary statistical challenge that must be addressed when using cross-sectional data to estimate the consequences of consuming addictive substances is the likely endogeneity of substance use. While economists are in agreement on the need to consider potential endogeneity bias and the value of instrumental variables estimation, the selection of credible instruments is a topic of heated debate in the field. Rather than attempt to resolve this debate, our paper highlights the diversity of judgments about what constitutes appropriate instruments for substance use based on a comprehensive review of the economics literature since 1990. We then offer recommendations related to the selection of reliable instruments in future studies. PMID:20029936

Spillover Effects of Adult Medicaid Expansions on Children's Use of Preventive Services.

PubMed

Venkataramani, Maya; Pollack, Craig Evan; Roberts, Eric T

2017-12-01

Since the passage of the Affordable Care Act, Medicaid enrollment has increased by ∼17 million adults, including many low-income parents. One potentially important, but little studied, consequence of expanding health insurance for parents is its effect on children's receipt of preventive services. By using state Medicaid eligibility thresholds linked to the 2001-2013 Medical Expenditure Panel Surveys, we assessed the relationship between changes in adult Medicaid eligibility and children's likelihood of receiving annual well-child visits (WCVs). In instrumental variable analyses, we used these changes in Medicaid eligibility to estimate the relationship between parental enrollment in Medicaid and children's receipt of WCVs. Our analytic sample consisted of 50 622 parent-child dyads in families with incomes <200% of the federal poverty level, surveyed from 2001 to 2013. On average, a 10-point increase in a state's parental Medicaid eligibility (measured relative to the federal poverty level) was associated with a 0.27 percentage point higher probability that a child received an annual WCV (95% confidence interval: 0.058 to 0.48 percentage points, P = .012). Instrumental variable analyses revealed that parental enrollment in Medicaid was associated with a 29 percentage point higher probability that their child received an annual WCV (95% confidence interval: 11 to 47 percentage points, P = .002). In our study, we demonstrate that Medicaid expansions targeted at low-income adults are associated with increased receipt of recommended pediatric preventive care for their children. This finding reveals an important spillover effect of parental insurance coverage that should be considered in future policy decisions surrounding adult Medicaid eligibility. Copyright © 2017 by the American Academy of Pediatrics.

Network Mendelian randomization: using genetic variants as instrumental variables to investigate mediation in causal pathways

PubMed Central

Burgess, Stephen; Daniel, Rhian M; Butterworth, Adam S; Thompson, Simon G

2015-01-01

Background: Mendelian randomization uses genetic variants, assumed to be instrumental variables for a particular exposure, to estimate the causal effect of that exposure on an outcome. If the instrumental variable criteria are satisfied, the resulting estimator is consistent even in the presence of unmeasured confounding and reverse causation. Methods: We extend the Mendelian randomization paradigm to investigate more complex networks of relationships between variables, in particular where some of the effect of an exposure on the outcome may operate through an intermediate variable (a mediator). If instrumental variables for the exposure and mediator are available, direct and indirect effects of the exposure on the outcome can be estimated, for example using either a regression-based method or structural equation models. The direction of effect between the exposure and a possible mediator can also be assessed. Methods are illustrated in an applied example considering causal relationships between body mass index, C-reactive protein and uric acid. Results: These estimators are consistent in the presence of unmeasured confounding if, in addition to the instrumental variable assumptions, the effects of both the exposure on the mediator and the mediator on the outcome are homogeneous across individuals and linear without interactions. Nevertheless, a simulation study demonstrates that even considerable heterogeneity in these effects does not lead to bias in the estimates. Conclusions: These methods can be used to estimate direct and indirect causal effects in a mediation setting, and have potential for the investigation of more complex networks between multiple interrelated exposures and disease outcomes. PMID:25150977

Instrumental and perceptual phonetic analyses: the case for two-tier transcriptions.

PubMed

Howard, Sara; Heselwood, Barry

2011-11-01

In this article, we discuss the relationship between instrumental and perceptual phonetic analyses. Using data drawn from typical and atypical speech production, we argue that the use of two-tier transcriptions, which can compare and contrast perceptual and instrumental information, is valuable both for our general understanding of the mechanisms of speech production and perception and also for assessment and intervention for individuals with atypical speech production. The central tenet of our case is that instrumental and perceptual analyses are not in competition to give a single 'correct' account of speech data. They take instead perspectives on complementary phonetic domains, which interlock in the speech chain to encompass production, transmission and perception.

Treating pre-instrumental data as "missing" data: using a tree-ring-based paleoclimate record and imputations to reconstruct streamflow in the Missouri River Basin

NASA Astrophysics Data System (ADS)

Ho, M. W.; Lall, U.; Cook, E. R.

2015-12-01

Advances in paleoclimatology in the past few decades have provided opportunities to expand the temporal perspective of the hydrological and climatological variability across the world. The North American region is particularly fortunate in this respect where a relatively dense network of high resolution paleoclimate proxy records have been assembled. One such network is the annually-resolved Living Blended Drought Atlas (LBDA): a paleoclimate reconstruction of the Palmer Drought Severity Index (PDSI) that covers North America on a 0.5° × 0.5° grid based on tree-ring chronologies. However, the use of the LBDA to assess North American streamflow variability requires a model by which streamflow may be reconstructed. Paleoclimate reconstructions have typically used models that first seek to quantify the relationship between the paleoclimate variable and the environmental variable of interest before extrapolating the relationship back in time. In contrast, the pre-instrumental streamflow is here considered as "missing" data. A method of imputing the "missing" streamflow data, prior to the instrumental record, is applied through multiple imputation using chained equations for streamflow in the Missouri River Basin. In this method, the distribution of the instrumental streamflow and LBDA is used to estimate sets of plausible values for the "missing" streamflow data resulting in a ~600 year-long streamflow reconstruction. Past research into external climate forcings, oceanic-atmospheric variability and its teleconnections, and assessments of rare multi-centennial instrumental records demonstrate that large temporal oscillations in hydrological conditions are unlikely to be captured in most instrumental records. The reconstruction of multi-centennial records of streamflow will enable comprehensive assessments of current and future water resource infrastructure and operations under the existing scope of natural climate variability.

The Lebanese Armed Forces Engaging Nahr Al-Bared Palestinian Refugee Camp Using the Instruments of National Power

DTIC Science & Technology

2017-06-09

organization. Then, the study analyses the use of the Diplomatic, Informational, Military, and Economic instruments of national power (DIME) by the LAF in...Then, the study analyses the use of the Diplomatic, Informational, Military, and Economic instruments of national power (DIME) by the LAF in...56 Economic Element of National Power

Automated haematology analysis to diagnose malaria

PubMed Central

2010-01-01

For more than a decade, flow cytometry-based automated haematology analysers have been studied for malaria diagnosis. Although current haematology analysers are not specifically designed to detect malaria-related abnormalities, most studies have found sensitivities that comply with WHO malaria-diagnostic guidelines, i.e. ≥ 95% in samples with > 100 parasites/μl. Establishing a correct and early malaria diagnosis is a prerequisite for an adequate treatment and to minimizing adverse outcomes. Expert light microscopy remains the 'gold standard' for malaria diagnosis in most clinical settings. However, it requires an explicit request from clinicians and has variable accuracy. Malaria diagnosis with flow cytometry-based haematology analysers could become an important adjuvant diagnostic tool in the routine laboratory work-up of febrile patients in or returning from malaria-endemic regions. Haematology analysers so far studied for malaria diagnosis are the Cell-Dyn®, Coulter® GEN·S and LH 750, and the Sysmex XE-2100® analysers. For Cell-Dyn analysers, abnormal depolarization events mainly in the lobularity/granularity and other scatter-plots, and various reticulocyte abnormalities have shown overall sensitivities and specificities of 49% to 97% and 61% to 100%, respectively. For the Coulter analysers, a 'malaria factor' using the monocyte and lymphocyte size standard deviations obtained by impedance detection has shown overall sensitivities and specificities of 82% to 98% and 72% to 94%, respectively. For the XE-2100, abnormal patterns in the DIFF, WBC/BASO, and RET-EXT scatter-plots, and pseudoeosinophilia and other abnormal haematological variables have been described, and multivariate diagnostic models have been designed with overall sensitivities and specificities of 86% to 97% and 81% to 98%, respectively. The accuracy for malaria diagnosis may vary according to species, parasite load, immunity and clinical context where the method is applied. Future developments in new haematology analysers such as considerably simplified, robust and inexpensive devices for malaria detection fitted with an automatically generated alert could improve the detection capacity of these instruments and potentially expand their clinical utility in malaria diagnosis. PMID:21118557

Using naturalistic driving data to identify variables associated with infrequent, occasional, and consistent seat belt use.

PubMed

Reagan, Ian J; McClafferty, Julie A; Berlin, Sharon P; Hankey, Jonathan M

2013-01-01

Seat belt use is one of the most effective countermeasures to reduce traffic fatalities and injuries. The success of efforts to increase use is measured by road side observations and self-report questionnaires. These methods have shortcomings, with the former requiring a binary point estimate and the latter being subjective. The 100-car naturalistic driving study presented a unique opportunity to study seat belt use in that seat belt status was known for every trip each driver made during a 12-month period. Drivers were grouped into infrequent, occasional, or consistent seat belt users based on the frequency of belt use. Analyses were then completed to assess if these groups differed on several measures including personality, demographics, self-reported driving style variables as well as measures from the 100-car study instrumentation suite (average trip speed, trips per day). In addition, detailed analyses of the occasional belt user group were completed to identify factors that were predictive of occasional belt users wearing their belts. The analyses indicated that consistent seat belt users took fewer trips per day, and that increased average trip speed was associated with increased belt use among occasional belt users. The results of this project may help focus messaging efforts to convert occasional and inconsistent seat belt users to consistent users. Copyright © 2012 Elsevier Ltd. All rights reserved.

Adjustment between work demands and health needs: Development of the Work-Health Balance Questionnaire.

PubMed

Gragnano, Andrea; Miglioretti, Massimo; Frings-Dresen, Monique H W; de Boer, Angela G E M

2017-08-01

This study presented the construct of Work-Health Balance (WHB) and the design and validation of the Work-Health Balance Questionnaire (WHBq). More and more workers have a long-standing health problem or disability (LSHPD). The management of health needs and work demands is crucial for the quality of working life and work retention of these workers. However, no instrument exists measuring this process. The WHBq assesses key factors in the process of adjusting between health needs and work demands. We tested the reliability and validity of 38 items with cross-sectional data from a sample of 321 Italian workers (mean age = 45 ± 11 years) using exploratory factor analysis (EFA), Rasch analyses, and the correlations with other relevant variables. The instrument ultimately consisted of 17 items that reliably measured three factors: work-health incompatibility, health climate, and external support. These dimensions were associated with well-being in the workplace, dysfunctional behaviors at work, and general psychological health. A higher level on the WHB index was associated with lower levels of presenteeism, emotional exhaustion, workaholism, and psychological distress and with higher levels of job satisfaction and work engagement, supporting the construct validity of the instrument. The WHBq shows good psychometric characteristics and strong and theoretically consistent relationships with important and well-known variables. These results make the WHBq a promising tool in the study and management of health of employees, especially for the work continuation of employees returning to work with LSHPD. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Instrumental variables I: instrumental variables exploit natural variation in nonexperimental data to estimate causal relationships.

PubMed

Rassen, Jeremy A; Brookhart, M Alan; Glynn, Robert J; Mittleman, Murray A; Schneeweiss, Sebastian

2009-12-01

The gold standard of study design for treatment evaluation is widely acknowledged to be the randomized controlled trial (RCT). Trials allow for the estimation of causal effect by randomly assigning participants either to an intervention or comparison group; through the assumption of "exchangeability" between groups, comparing the outcomes will yield an estimate of causal effect. In the many cases where RCTs are impractical or unethical, instrumental variable (IV) analysis offers a nonexperimental alternative based on many of the same principles. IV analysis relies on finding a naturally varying phenomenon, related to treatment but not to outcome except through the effect of treatment itself, and then using this phenomenon as a proxy for the confounded treatment variable. This article demonstrates how IV analysis arises from an analogous but potentially impossible RCT design, and outlines the assumptions necessary for valid estimation. It gives examples of instruments used in clinical epidemiology and concludes with an outline on estimation of effects.

Instrumental variables I: instrumental variables exploit natural variation in nonexperimental data to estimate causal relationships

PubMed Central

Rassen, Jeremy A.; Brookhart, M. Alan; Glynn, Robert J.; Mittleman, Murray A.; Schneeweiss, Sebastian

2010-01-01

The gold standard of study design for treatment evaluation is widely acknowledged to be the randomized controlled trial (RCT). Trials allow for the estimation of causal effect by randomly assigning participants either to an intervention or comparison group; through the assumption of “exchangeability” between groups, comparing the outcomes will yield an estimate of causal effect. In the many cases where RCTs are impractical or unethical, instrumental variable (IV) analysis offers a nonexperimental alternative based on many of the same principles. IV analysis relies on finding a naturally varying phenomenon, related to treatment but not to outcome except through the effect of treatment itself, and then using this phenomenon as a proxy for the confounded treatment variable. This article demonstrates how IV analysis arises from an analogous but potentially impossible RCT design, and outlines the assumptions necessary for valid estimation. It gives examples of instruments used in clinical epidemiology and concludes with an outline on estimation of effects. PMID:19356901

Quantifying inter-laboratory variability in stable isotope analysis of ancient skeletal remains.

PubMed

Pestle, William J; Crowley, Brooke E; Weirauch, Matthew T

2014-01-01

Over the past forty years, stable isotope analysis of bone (and tooth) collagen and hydroxyapatite has become a mainstay of archaeological and paleoanthropological reconstructions of paleodiet and paleoenvironment. Despite this method's frequent use across anthropological subdisciplines (and beyond), the present work represents the first attempt at gauging the effects of inter-laboratory variability engendered by differences in a) sample preparation, and b) analysis (instrumentation, working standards, and data calibration). Replicate analyses of a 14C-dated ancient human bone by twenty-one archaeological and paleoecological stable isotope laboratories revealed significant inter-laboratory isotopic variation for both collagen and carbonate. For bone collagen, we found a sizeable range of 1.8‰ for δ13Ccol and 1.9‰ for δ15Ncol among laboratories, but an interpretatively insignificant average pairwise difference of 0.2‰ and 0.4‰ for δ13Ccol and δ15Ncol respectively. For bone hydroxyapatite the observed range increased to a troublingly large 3.5‰ for δ13Cap and 6.7‰ for δ18Oap, with average pairwise differences of 0.6‰ for δ13Cap and a disquieting 2.0‰ for δ18Oap. In order to assess the effects of preparation versus analysis on isotopic variability among laboratories, a subset of the samples prepared by the participating laboratories were analyzed a second time on the same instrument. Based on this duplicate analysis, it was determined that roughly half of the isotopic variability among laboratories could be attributed to differences in sample preparation, with the other half resulting from differences in analysis (instrumentation, working standards, and data calibration). These findings have serious implications for choices made in the preparation and extraction of target biomolecules, the comparison of results obtained from different laboratories, and the interpretation of small differences in bone collagen and hydroxyapatite isotope values. To address the issues arising from inter-laboratory comparisons, we devise a novel measure we term the Minimum Meaningful Difference (MMD), and demonstrate its application.

Quantifying Inter-Laboratory Variability in Stable Isotope Analysis of Ancient Skeletal Remains

PubMed Central

Pestle, William J.; Crowley, Brooke E.; Weirauch, Matthew T.

2014-01-01

Over the past forty years, stable isotope analysis of bone (and tooth) collagen and hydroxyapatite has become a mainstay of archaeological and paleoanthropological reconstructions of paleodiet and paleoenvironment. Despite this method's frequent use across anthropological subdisciplines (and beyond), the present work represents the first attempt at gauging the effects of inter-laboratory variability engendered by differences in a) sample preparation, and b) analysis (instrumentation, working standards, and data calibration). Replicate analyses of a 14C-dated ancient human bone by twenty-one archaeological and paleoecological stable isotope laboratories revealed significant inter-laboratory isotopic variation for both collagen and carbonate. For bone collagen, we found a sizeable range of 1.8‰ for δ13Ccol and 1.9‰ for δ15Ncol among laboratories, but an interpretatively insignificant average pairwise difference of 0.2‰ and 0.4‰ for δ13Ccol and δ15Ncol respectively. For bone hydroxyapatite the observed range increased to a troublingly large 3.5‰ for δ13Cap and 6.7‰ for δ18Oap, with average pairwise differences of 0.6‰ for δ13Cap and a disquieting 2.0‰ for δ18Oap. In order to assess the effects of preparation versus analysis on isotopic variability among laboratories, a subset of the samples prepared by the participating laboratories were analyzed a second time on the same instrument. Based on this duplicate analysis, it was determined that roughly half of the isotopic variability among laboratories could be attributed to differences in sample preparation, with the other half resulting from differences in analysis (instrumentation, working standards, and data calibration). These findings have serious implications for choices made in the preparation and extraction of target biomolecules, the comparison of results obtained from different laboratories, and the interpretation of small differences in bone collagen and hydroxyapatite isotope values. To address the issues arising from inter-laboratory comparisons, we devise a novel measure we term the Minimum Meaningful Difference (MMD), and demonstrate its application. PMID:25061843

Propensity-score matching in economic analyses: comparison with regression models, instrumental variables, residual inclusion, differences-in-differences, and decomposition methods.

PubMed

Crown, William H

2014-02-01

This paper examines the use of propensity score matching in economic analyses of observational data. Several excellent papers have previously reviewed practical aspects of propensity score estimation and other aspects of the propensity score literature. The purpose of this paper is to compare the conceptual foundation of propensity score models with alternative estimators of treatment effects. References are provided to empirical comparisons among methods that have appeared in the literature. These comparisons are available for a subset of the methods considered in this paper. However, in some cases, no pairwise comparisons of particular methods are yet available, and there are no examples of comparisons across all of the methods surveyed here. Irrespective of the availability of empirical comparisons, the goal of this paper is to provide some intuition about the relative merits of alternative estimators in health economic evaluations where nonlinearity, sample size, availability of pre/post data, heterogeneity, and missing variables can have important implications for choice of methodology. Also considered is the potential combination of propensity score matching with alternative methods such as differences-in-differences and decomposition methods that have not yet appeared in the empirical literature.

Developing and testing an instrument to measure the presence of conditions for successful implementation of quality improvement collaboratives.

PubMed

Dückers, Michel L A; Wagner, Cordula; Groenewegen, Peter P

2008-08-11

In quality improvement collaboratives (QICs) teams of practitioners from different health care organizations are brought together to systematically improve an aspect of patient care. Teams take part in a series of meetings to learn about relevant best practices, quality methods and change ideas, and share experiences in making changes in their own local setting. The purpose of this study was to develop an instrument for measuring team organization, external change agent support and support from the team's home institution in a Dutch national improvement and dissemination programme for hospitals based on several QICs. The exploratory methodological design included two phases: a) content development and assessment, resulting in an instrument with 15 items, and b) field testing (N = 165). Internal consistency reliability was tested via Cronbach's alpha coefficient. Principal component analyses were used to identify underlying constructs. Tests of scaling assumptions according to the multi trait/multi-item matrix, were used to confirm the component structure. Three components were revealed, explaining 65% of the variability. The components were labelled 'organizational support', 'team organization' and 'external change agent support'. One item not meeting item-scale criteria was removed. This resulted in a 14 item instrument. Scale reliability ranged from 0.77 to 0.91. Internal item consistency and divergent validity were satisfactory. On the whole, the instrument appears to be a promising tool for assessing team organization and internal and external support during QIC implementation. The psychometric properties were good and warrant application of the instrument for the evaluation of the national programme and similar improvement programmes.

Comparison of mid-infrared transmission spectroscopy with biochemical methods for the determination of macronutrients in human milk.

PubMed

Silvestre, Dolores; Fraga, Miriam; Gormaz, María; Torres, Ester; Vento, Máximo

2014-07-01

The variability of human milk (HM) composition renders analysis of its components essential for optimal nutrition of preterm fed either with donor's or own mother's milk. To fulfil this requirement, various analytical instruments have been subjected to scientific and clinical evaluation. The objective of this study was to evaluate the suitability of a rapid method for the analysis of macronutrients in HM as compared with the analytical methods applied by cow's milk industry. Mature milk from 39 donors was analysed using an infrared human milk analyser (HMA) and compared with biochemical reference laboratory methods. The statistical analysis was based on the use of paired data tests. The use of an infrared HMA for the analysis of lipids, proteins and lactose in HM proved satisfactory as regards the rapidity, simplicity and the required sample volume. The instrument afforded good linearity and precision in application to all three nutrients. However, accuracy was not acceptable when compared with the reference methods, with overestimation of the lipid content and underestimation of the amount of proteins and lactose contents. The use of mid-infrared HMA might become the standard for rapid analysis of HM once standardisation and rigorous and systematic calibration is provided. © 2012 John Wiley & Sons Ltd.

Investigating circular patterns in linear polarization observations of Venus

NASA Astrophysics Data System (ADS)

Mahapatra, Gourav; Stam, Daphne; Rossi, Loic; Rodenhuis, Michiel; Snik, Frans

2017-04-01

ESA's Venus Express mission has revealed our neighbouring planet to be a highly dynamic world, with ever-changing cloud properties and structures, wind speeds that increase in time, and variable concentrations of atmospheric trace gases such as SO2. The SPICAV-IR instrument on Venus Express has provided us with close-up linear polarization data of sunlight reflected by Venus's clouds and hazes, that allows a characterisation of their composition and particle sizes. Here, we analyse linear polarization data of the planet at a distance, obtained with the Extreme Polarimeter (ExPo) on the William Herschel Telescope on La Palma. These spatially resolved, high-accuracy polarization observations of Venus show faint circular patterns centered on the sub-solar point that are absent in the flux observations. So far, careful analyses have ruled out instrumental effects which leaves us to wonder about atmospheric properties as the cause of the circular patterns. Using numerical simulations of the flux and polarization of sunlight that is reflected by Venus, we have investigated the relation between the observed patterns and several atmospheric properties, such as variations in particle sizes, composition, density and altitude. We discuss the plausibility of the possible causes in the view of the current knowledge of the composition and dynamical processes in Venus's atmosphere.

Analysis of temperature rise and the use of coolants in the dissipation of ultrasonic heat buildup during post removal.

PubMed

Davis, Stephen; Gluskin, Alan H; Livingood, Philip M; Chambers, David W

2010-11-01

This study was designed to calculate probabilities for tissue injury and to measure effectiveness of various coolant strategies in countering heat buildup produced by dry ultrasonic vibration during post removal. A simulated biological model was used to evaluate the cooling efficacy of a common refrigerant spray, water spray, and air spray in the recovery of post temperatures deep within the root canal space. The data set consisted of cervical and apical measures of temperature increase at 1-second intervals from baseline during continuous ultrasonic instrumentation until a 10 °C increase in temperature at the cervical site was registered, wherein instrumentation ceased, and the teeth were allowed to cool under ambient conditions or with the assistance of 4 coolant methods. Data were analyzed with analysis of variance by using the independent variables of time of ultrasonic application (10, 15, 20 seconds) and cooling method. In addition to the customary means, standard deviations, and analysis of variance tests, analyses were conducted to determine probabilities that procedures would reach or exceed the 10 °C threshold. Both instrumentation time and cooling agent effects were significant at P <.0001. Under the conditions of this study, it was shown that injurious heat transfer occurs in less than 1 minute during dry ultrasonic instrumentation of metallic posts. Cycles of short instrumentation times with active coolants were effective in reducing the probability of tissue damage when teeth were instrumented dry. With as little as 20 seconds of continuous dry ultrasonic instrumentation, the consequences of thermal buildup to an individual tooth might contribute to an injurious clinical outcome. Copyright © 2010 American Association of Endodontists. All rights reserved.

Comparative effectiveness of chemotherapy vs resection of the primary tumour as the initial treatment in older patients with Stage IV colorectal cancer.

PubMed

Mehta, H B; Vargas, G M; Adhikari, D; Dimou, F; Riall, T S

2017-06-01

The objectives were to determine trends in the use of chemotherapy as the initial treatment and to evaluate the comparative effectiveness of initial chemotherapy vs resection of the primary tumour on survival (intention-to-treat analysis) in Stage IV colorectal cancer (CRC). This cohort study used 2000-2011 data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database, including patients ≥ 66 years of age presenting with Stage IV CRC. Cox proportional hazards models and instrumental variable analysis were used to compare the effectiveness of chemotherapy as the initial treatment with resection of the primary tumour as the initial treatment, with 2-year survival as the end point. The use of chemotherapy as the first treatment increased over time, from 26.8% in 2001 to 46.9% in 2009 (P < 0.0001). The traditional Cox model showed that chemotherapy as the initial treatment was associated with a higher risk of mortality [hazard ratio (HR) = 1.35; 95% CI: 1.27-1.44]. When accounting for known and unknown confounders in an instrumental variable analysis, chemotherapy as the initial treatment suggested benefit on 2-year survival (HR = 0.68; 95% CI: 0.44-1.04); however, the association did not reach statistical significance. The study findings were similar in six subgroup analyses. The use of chemotherapy as the initial therapy for CRC increased substantially from 2001 to 2009. Instrumental variable analysis found that, compared with resection, chemotherapy as the initial treatment offers similar or better 2-year survival in patients with Stage IV CRC. Given the morbidity and mortality associated with colorectal resection in elderly patients, chemotherapy provides an option to patients who are not good candidates for resection. Colorectal Disease © 2017 The Association of Coloproctology of Great Britain and Ireland.

Development of an instrument for community-level health related social capital among Japanese older people: The JAGES Project.

PubMed

Saito, Masashige; Kondo, Naoki; Aida, Jun; Kawachi, Ichiro; Koyama, Shihoko; Ojima, Toshiyuki; Kondo, Katsunori

2017-05-01

We developed and validated an instrument to measure community-level social capital based on data derived from older community dwellers in Japan. We used cross-sectional data from the Japan Gerontological Evaluation Study, a nationwide survey involving 123,760 functionally independent older people nested within 702 communities (i.e., school districts). We conducted exploratory and confirmatory factor analyses on survey items to determine the items in a multi-dimensional scale to measure community social capital. Internal consistency was checked with Cronbach's alpha. Convergent construct validity was assessed via correlating the scale with health outcomes. From 53 candidate variables, 11 community-level variables were extracted: participation in volunteer groups, sports groups, hobby activities, study or cultural groups, and activities for teaching specific skills; trust, norms of reciprocity, and attachment to one's community; received emotional support; provided emotional support; and received instrumental support. Using factor analysis, these variables were determined to belong to three sub-scales: civic participation (eigenvalue = 3.317, α = 0.797), social cohesion (eigenvalue = 2.633, α = 0.853), and reciprocity (eigenvalue = 1.424, α = 0.732). Confirmatory factor analysis indicated the goodness of fit of this model. Multilevel Poisson regression analysis revealed that civic participation score was robustly associated with individual subjective health (Self-Rated Health: prevalence ratio [PR] 0.96; 95% confidence interval [CI], 0.94-0.98; Geriatric Depression Scale [GDS]: PR 0.95; 95% CI, 0.93-0.97). Reciprocity score was also associated with individual GDS (PR 0.98; 95% CI, 0.96-1.00). Social cohesion score was not consistently associated with individual health indicators. Our scale for measuring social capital at the community level might be useful for future studies of older community dwellers. Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Analysing Instrument Mixes in Quality Assurance: The Czech and Slovak Accreditation Commissions in the Era of Mass Higher Education

ERIC Educational Resources Information Center

Kohoutek, Jan

2014-01-01

Utilising insights from policy instrument theory, the article analyses the design, functioning and effects of the tools used by the Czech Accreditation Commission (CAC) and the Slovak Accreditation Commission (SAC) in the 2000s. Aside from programme accreditation, the other tools analysed are: institutional approval, institutional evaluations,…

Data Combination and Instrumental Variables in Linear Models

ERIC Educational Resources Information Center

Khawand, Christopher

2012-01-01

Instrumental variables (IV) methods allow for consistent estimation of causal effects, but suffer from poor finite-sample properties and data availability constraints. IV estimates also tend to have relatively large standard errors, often inhibiting the interpretability of differences between IV and non-IV point estimates. Lastly, instrumental…

Measuring organizational and individual factors thought to influence the success of quality improvement in primary care: a systematic review of instruments

PubMed Central

2012-01-01

Background Continuous quality improvement (CQI) methods are widely used in healthcare; however, the effectiveness of the methods is variable, and evidence about the extent to which contextual and other factors modify effects is limited. Investigating the relationship between these factors and CQI outcomes poses challenges for those evaluating CQI, among the most complex of which relate to the measurement of modifying factors. We aimed to provide guidance to support the selection of measurement instruments by systematically collating, categorising, and reviewing quantitative self-report instruments. Methods Data sources: We searched MEDLINE, PsycINFO, and Health and Psychosocial Instruments, reference lists of systematic reviews, and citations and references of the main report of instruments. Study selection: The scope of the review was determined by a conceptual framework developed to capture factors relevant to evaluating CQI in primary care (the InQuIRe framework). Papers reporting development or use of an instrument measuring a construct encompassed by the framework were included. Data extracted included instrument purpose; theoretical basis, constructs measured and definitions; development methods and assessment of measurement properties. Analysis and synthesis: We used qualitative analysis of instrument content and our initial framework to develop a taxonomy for summarising and comparing instruments. Instrument content was categorised using the taxonomy, illustrating coverage of the InQuIRe framework. Methods of development and evidence of measurement properties were reviewed for instruments with potential for use in primary care. Results We identified 186 potentially relevant instruments, 152 of which were analysed to develop the taxonomy. Eighty-four instruments measured constructs relevant to primary care, with content measuring CQI implementation and use (19 instruments), organizational context (51 instruments), and individual factors (21 instruments). Forty-one instruments were included for full review. Development methods were often pragmatic, rather than systematic and theory-based, and evidence supporting measurement properties was limited. Conclusions Many instruments are available for evaluating CQI, but most require further use and testing to establish their measurement properties. Further development and use of these measures in evaluations should increase the contribution made by individual studies to our understanding of CQI and enhance our ability to synthesise evidence for informing policy and practice. PMID:23241168

Critical evaluation of connectivity-based point of care testing systems of glucose in a hospital environment.

PubMed

Floré, Katelijne M J; Fiers, Tom; Delanghe, Joris R

2008-01-01

In recent years a number of point of care testing (POCT) glucometers were introduced on the market. We investigated the analytical variability (lot-to-lot variation, calibration error, inter-instrument and inter-operator variability) of glucose POCT systems in a university hospital environment and compared these results with the analytical needs required for tight glucose monitoring. The reference hexokinase method was compared to different POCT systems based on glucose oxidase (blood gas instruments) or glucose dehydrogenase (handheld glucometers). Based upon daily internal quality control data, total errors were calculated for the various glucose methods and the analytical variability of the glucometers was estimated. The total error of the glucometers exceeded by far the desirable analytical specifications (based on a biological variability model). Lot-to-lot variation, inter-instrument variation and inter-operator variability contributed approximately equally to total variance. As in a hospital environment, distribution of hematocrit values is broad, converting blood glucose into plasma values using a fixed factor further increases variance. The percentage of outliers exceeded the ISO 15197 criteria in a broad glucose concentration range. Total analytical variation of handheld glucometers is larger than expected. Clinicians should be aware that the variability of glucose measurements obtained by blood gas instruments is lower than results obtained with handheld glucometers on capillary blood.

Fire history and fire-climate relationships in upper elevation forests of the southwestern United States

NASA Astrophysics Data System (ADS)

Margolis, Ellis Quinn

Fire history and fire-climate relationships of upper elevation forests of the southwestern United States are imperative for informing management decisions in the face of increased crown fire occurrence and climate change. I used dendroecological techniques to reconstruct fires and stand-replacing fire patch size in the Madrean Sky Islands and Mogollon Plateau. Reconstructed patch size (1685-1904) was compared with contemporary patch size (1996-2004). Reconstructed fires at three sites had stand-replacing patches totaling > 500 ha. No historical stand-replacing fire patches were evident in the mixed conifer/aspen forests of the Sky Islands. Maximum stand-replacing fire patch size of modern fires (1129 ha) was greater than that reconstructed from aspen (286 ha) and spruce-fir (521 ha). Undated spruce-fir patches may be evidence of larger (>2000ha) stand-replacing fire patches. To provide climatological context for fire history I used correlation and regionalization analyses to document spatial and temporal variability in climate regions, and El-Nino Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and the Atlantic Multi-decadal Oscillation (AMO) teleconnections using 273 tree-ring chronologies (1732-1979). Four regions were determined by common variability in annual ring width. The component score time series replicate spatial variability in 20th century droughts (e.g., 1950's) and pluvials (e.g., 1910's). Two regions were significantly correlated with instrumental SOI and AMO, and three with PDO. Sub-regions within the southwestern U.S. varied geographically between the instrumental (1900-1979) and the pre-instrumental periods (1732-1899). Mapped correlations between ENSO, PDO and AMO, and tree-ring indices illustrate detailed sub-regional variability in the teleconnections. I analyzed climate teleconnections, and fire-climate relationships of historical upper elevation fires from 16 sites in 8 mountain ranges. I tested for links between Palmer Drought Severity Index and tree-ring reconstructed ENSO, PDO and AMO phases (1905-1978 and 1700-1904). Upper elevation fires (115 fires, 84 fire years, 1623-1904) were compared with climate indices. ENSO, PDO, and AMO affected regional PDSI, but AMO and PDO teleconnections changed between periods. Fire occurrence was significantly related to inter-annual variability in PDSI, precipitation, ENSO, and phase combinations of ENSO and PDO, but not AMO (1700-1904). Reduced upper elevation fire (1785-1840) was coincident with a cool AMO phase.

Imprint of the Atlantic Multidecadal Oscillation on Tree-Ring Widths in Northeastern Asia since 1568

PubMed Central

Wang, Xiaochun; Brown, Peter M.; Zhang, Yanni; Song, Laiping

2011-01-01

We present a new tree-ring reconstruction of the Atlantic Multidecadal Oscillation (AMO) spanning 1568–2007 CE from northeast Asia. Comparison of the instrumental AMO index, an existing tree-ring based AMO reconstruction, and this new record show strongly similar annual to multidecadal patterns of variation over the last 440 years. Warm phases of the AMO are related to increases in growth of Scots pine trees and moisture availability in northeast China and central eastern Siberia. Multi-tape method (MTM) and cross-wavelet analyses indicate that robust multidecadal (∼64–128 years) variability is present throughout the new proxy record. Our results have important implications concerning the influence of North Atlantic sea surface temperatures on East Asian climate, and provide support for the possibility of an AMO signature on global multidecadal climate variability. PMID:21818380

Rural parents' perceived stigma of seeking mental health services for their children: development and evaluation of a new instrument.

PubMed

Williams, Stacey L; Polaha, Jodi

2014-09-01

The purpose of our research was to examine the validity of score interpretations of an instrument developed to measure parents' perceptions of stigma about seeking mental health services for their children. The validity of the score interpretations of the instrument was tested in 2 studies. Study 1 employed confirmatory factor analysis (CFA), using a split half approach, and construct and criterion validity on data from the entire sample of parents in rural Appalachia whose children were experiencing psychosocial concerns (N = 347), while Study 2 employed CFA, construct and criterion validity, and predictive validity of the scores on data from a general sample of parents in rural Appalachia (N = 184). Results of exploratory and confirmatory factor analyses revealed support for a 2-factor model of parents' perceived stigma, which represented both self and public forms of stigma associated with seeking mental health services for their children, and correlated with existing measures of stigma and other psychosocial variables. Further, the new self and public stigma scale significantly predicted parents' willingness to seek services for children. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Mesoscale Gravity Wave Variances from AMSU-A Radiances

NASA Technical Reports Server (NTRS)

Wu, Dong L.

2004-01-01

A variance analysis technique is developed here to extract gravity wave (GW) induced temperature fluctuations from NOAA AMSU-A (Advanced Microwave Sounding Unit-A) radiance measurements. By carefully removing the instrument/measurement noise, the algorithm can produce reliable GW variances with the minimum detectable value as small as 0.1 K2. Preliminary analyses with AMSU-A data show GW variance maps in the stratosphere have very similar distributions to those found with the UARS MLS (Upper Atmosphere Research Satellite Microwave Limb Sounder). However, the AMSU-A offers better horizontal and temporal resolution for observing regional GW variability, such as activity over sub-Antarctic islands.

Engagement, resilience and empathy in nursing assistants.

PubMed

Navarro-Abal, Yolanda; López-López, M José; Climent-Rodríguez, José A

To analyse the levels of engagement, resilience and empathy, and the relationship between them, in a sample of nursing assistants working in different private institutions in Huelva. A transversal, descriptive study. The sample comprised 128 nursing assistants working in private health centres of Huelva. They were given the following instruments: resilience scale Wagnild and Young, Interpersonal Reactivity Index and Utrech Work Engagement Scale. There is a relationship between the cognitive and emotional components of engagement and empathy. Certain sociodemographic variables associated with the organisation of work and working conditions are associated with level of engagement. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Stable carbon isotope analyses of nanogram quantities of particulate organic carbon (pollen) with laser ablation nano combustion gas chromatography/isotope ratio mass spectrometry

PubMed Central

Sluijs, Appy; Laks, Jelmer J.; Reichart, Gert‐Jan

2016-01-01

Rationale Analyses of stable carbon isotope ratios (δ 13C values) of organic and inorganic matter remains have been instrumental for much of our understanding of present and past environmental and biological processes. Until recently, the analytical window of such analyses has been limited to samples containing at least several μg of carbon. Methods Here we present a setup combining laser ablation, nano combustion gas chromatography and isotope ratio mass spectrometry (LA/nC/GC/IRMS). A deep UV (193 nm) laser is used for optimal fragmentation of organic matter with minimum fractionation effects and an exceptionally small ablation chamber and combustion oven are used to reduce the minimum sample mass requirement compared with previous studies. Results Analyses of the international IAEA CH‐7 polyethylene standard show optimal accuracy, and precision better than 0.5‰, when measuring at least 42 ng C. Application to untreated modern Eucalyptus globulus (C3 plant) and Zea mays (C4 plant) pollen grains shows a ~ 16‰ offset between these species. Within each single Z. mays pollen grain, replicate analyses show almost identical δ 13C values. Conclusions Isotopic offsets between individual pollen grains exceed analytical uncertainties, therefore probably reflecting interspecimen variability of ~0.5–0.9‰. These promising results set the stage for investigating both δ 13C values and natural carbon isotopic variability between single specimens of a single population of all kinds of organic particles yielding tens of nanograms of carbon. © 2016 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd. PMID:27766694

Some Open Issues on Rockfall Hazard Analysis in Fractured Rock Mass: Problems and Prospects

NASA Astrophysics Data System (ADS)

Ferrero, Anna Maria; Migliazza, Maria Rita; Pirulli, Marina; Umili, Gessica

2016-09-01

Risk is part of every sector of engineering design. It is a consequence of the uncertainties connected with the cognitive boundaries and with the natural variability of the relevant variables. In soil and rock engineering, in particular, uncertainties are linked to geometrical and mechanical aspects and the model used for the problem schematization. While the uncertainties due to the cognitive gaps could be filled by improving the quality of numerical codes and measuring instruments, nothing can be done to remove the randomness of natural variables, except defining their variability with stochastic approaches. Probabilistic analyses represent a useful tool to run parametric analyses and to identify the more significant aspects of a given phenomenon: They can be used for a rational quantification and mitigation of risk. The connection between the cognitive level and the probability of failure is at the base of the determination of hazard, which is often quantified through the assignment of safety factors. But these factors suffer from conceptual limits, which can be only overcome by adopting mathematical techniques with sound bases, not so used up to now (Einstein et al. in rock mechanics in civil and environmental engineering, CRC Press, London, 3-13, 2010; Brown in J Rock Mech Geotech Eng 4(3):193-204, 2012). The present paper describes the problems and the more reliable techniques used to quantify the uncertainties that characterize the large number of parameters that are involved in rock slope hazard assessment through a real case specifically related to rockfall. Limits of the existing approaches and future developments of the research are also provided.

Three-factor model of premorbid adjustment in a sample with chronic schizophrenia and first-episode psychosis.

PubMed

Barajas, Ana; Usall, Judith; Baños, Iris; Dolz, Montserrat; Villalta-Gil, Victoria; Vilaplana, Miriam; Autonell, Jaume; Sánchez, Bernardo; Cervilla, Jorge A; Foix, Alexandrina; Obiols, Jordi E; Haro, Josep Maria; Ochoa, Susana

2013-12-01

The dimensionality of premorbid adjustment (PA) has been a debated issue, with attempts to determine whether PA is a unitary construct or composed of several independent domains characterized by a differential deterioration pattern and specific outcome correlates. This study examines the factorial structure of PA, as well as, the course and correlates of its domains. Retrospective study of 84 adult patients experiencing first-episode psychosis (FEP) (n=33) and individuals with schizophrenia (SCH) (n=51). All patients were evaluated with a comprehensive battery of instruments including clinical, functioning and neuropsychological variables. A principal component analysis accompanied by a varimax rotation method was used to examine the factor structure of the PAS-S scale. Paired t tests and Wilcoxon rank tests were used to assess the changes in PAS domains over time. Bivariate correlation analyses were performed to analyse the relationship between PAS factors and clinical, social and cognitive variables. PA was better explained by three factors (71.65% of the variance): Academic PA, Social PA and Socio-sexual PA. The academic domain showed higher scores of PA from childhood. Social and clinical variables were more strongly related to Social PA and Socio-sexual PA domains, and the Academic PA domain was exclusively associated with cognitive variables. This study supports previous evidence, emphasizing the validity of dividing PA into its sub-components. A differential deterioration pattern and specific correlates were observed in each PA domains, suggesting that impairments in each PA domain might predispose individuals to develop different expressions of psychotic dimensions. © 2013.

Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results

NASA Technical Reports Server (NTRS)

Hock, R. A.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Chamberlin, P. C.; Woods, E. C.

2010-01-01

The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. . In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

Eddy-covariance data with low signal-to-noise ratio: time-lag determination, uncertainties and limit of detection

NASA Astrophysics Data System (ADS)

Langford, B.; Acton, W.; Ammann, C.; Valach, A.; Nemitz, E.

2015-10-01

All eddy-covariance flux measurements are associated with random uncertainties which are a combination of sampling error due to natural variability in turbulence and sensor noise. The former is the principal error for systems where the signal-to-noise ratio of the analyser is high, as is usually the case when measuring fluxes of heat, CO2 or H2O. Where signal is limited, which is often the case for measurements of other trace gases and aerosols, instrument uncertainties dominate. Here, we are applying a consistent approach based on auto- and cross-covariance functions to quantify the total random flux error and the random error due to instrument noise separately. As with previous approaches, the random error quantification assumes that the time lag between wind and concentration measurement is known. However, if combined with commonly used automated methods that identify the individual time lag by looking for the maximum in the cross-covariance function of the two entities, analyser noise additionally leads to a systematic bias in the fluxes. Combining data sets from several analysers and using simulations, we show that the method of time-lag determination becomes increasingly important as the magnitude of the instrument error approaches that of the sampling error. The flux bias can be particularly significant for disjunct data, whereas using a prescribed time lag eliminates these effects (provided the time lag does not fluctuate unduly over time). We also demonstrate that when sampling at higher elevations, where low frequency turbulence dominates and covariance peaks are broader, both the probability and magnitude of bias are magnified. We show that the statistical significance of noisy flux data can be increased (limit of detection can be decreased) by appropriate averaging of individual fluxes, but only if systematic biases are avoided by using a prescribed time lag. Finally, we make recommendations for the analysis and reporting of data with low signal-to-noise and their associated errors.

Eddy-covariance data with low signal-to-noise ratio: time-lag determination, uncertainties and limit of detection

NASA Astrophysics Data System (ADS)

Langford, B.; Acton, W.; Ammann, C.; Valach, A.; Nemitz, E.

2015-03-01

All eddy-covariance flux measurements are associated with random uncertainties which are a combination of sampling error due to natural variability in turbulence and sensor noise. The former is the principal error for systems where the signal-to-noise ratio of the analyser is high, as is usually the case when measuring fluxes of heat, CO2 or H2O. Where signal is limited, which is often the case for measurements of other trace gases and aerosols, instrument uncertainties dominate. We are here applying a consistent approach based on auto- and cross-covariance functions to quantifying the total random flux error and the random error due to instrument noise separately. As with previous approaches, the random error quantification assumes that the time-lag between wind and concentration measurement is known. However, if combined with commonly used automated methods that identify the individual time-lag by looking for the maximum in the cross-covariance function of the two entities, analyser noise additionally leads to a systematic bias in the fluxes. Combining datasets from several analysers and using simulations we show that the method of time-lag determination becomes increasingly important as the magnitude of the instrument error approaches that of the sampling error. The flux bias can be particularly significant for disjunct data, whereas using a prescribed time-lag eliminates these effects (provided the time-lag does not fluctuate unduly over time). We also demonstrate that when sampling at higher elevations, where low frequency turbulence dominates and covariance peaks are broader, both the probability and magnitude of bias are magnified. We show that the statistical significance of noisy flux data can be increased (limit of detection can be decreased) by appropriate averaging of individual fluxes, but only if systematic biases are avoided by using a prescribed time-lag. Finally, we make recommendations for the analysis and reporting of data with low signal-to-noise and their associated errors.

[Productive activities and well-being among community-dwelling elderly].

PubMed

Okamoto, Hideaki

2009-10-01

This study examined the association between engagement in productive activities and well-being among community-dwelling elderly. Data for 576 older adults were obtained from a mail survey in Osaka City. The productive activities was measured with reference to three domains (paid work, unpaid work at home, and unpaid work outside the home) and the number of productive roles. Well-being was assessed by two measures: life satisfaction (LSIK) and self-rated health. The author used multivariate analyses with each of the two measures of well-being as dependent variables, and each of the productive activities as independent variables. The analyses were conducted separately for men and women, controlling for sociodemographic variables, IADL(instrumental activities of daily living) and social relationships. Multivariate analyses revealed the following findings. Paid work was positively associated with life satisfaction of women and self-rated health of men and women. Unpaid work at home was not significantly associated with life satisfaction or self-rated health for either men or women. However, unpaid work outside the home was related to higher scores for life satisfaction and self-rated health among women. The numbers of productive roles were positively associated with life satisfaction of women and self-rated health of men and women. Productive engagement was generally beneficial to older women's well-being except for unpaid work at home. Among men, only paid work out of the three activity domains and the number of productive roles were associated with better self-rated health. Public health policies and programs that bring older women into productive engagement outside the home may thus improve their well-being and generate benefits for communities.

Does Foot Anthropometry Predict Metabolic Cost During Running?

PubMed

van Werkhoven, Herman; Piazza, Stephen J

2017-10-01

Several recent investigations have linked running economy to heel length, with shorter heels being associated with less metabolic energy consumption. It has been hypothesized that shorter heels require larger plantar flexor muscle forces, thus increasing tendon energy storage and reducing metabolic cost. The goal of this study was to investigate this possible mechanism for metabolic cost reduction. Fifteen male subjects ran at 16 km⋅h -1 on a treadmill and subsequently on a force-plate instrumented runway. Measurements of oxygen consumption, kinematics, and ground reaction forces were collected. Correlational analyses were performed between oxygen consumption and anthropometric and kinetic variables associated with the ankle and foot. Correlations were also computed between kinetic variables (peak joint moment and peak tendon force) and heel length. Estimated peak Achilles tendon force normalized to body weight was found to be strongly correlated with heel length normalized to body height (r = -.751, p = .003). Neither heel length nor any other measured or calculated variable were correlated with oxygen consumption, however. Subjects with shorter heels experienced larger Achilles tendon forces, but these forces were not associated with reduced metabolic cost. No other anthropometric and kinetic variables considered explained the variance in metabolic cost across individuals.

Reconstructing coastal environmental condition in the eastern Norwegian Sea by means of Arctica islandica sclerochronological records

NASA Astrophysics Data System (ADS)

Trofimova, Tamara; Andersson, Carin

2015-04-01

Paleo archives are fundament in improving our knowledge of the natural climate variability. Established marine proxy records for the ocean, especially for high latitudes, are both sparsely distributed and are poorly resolved in time. The identification and development of new archives and proxies for studying key ocean processes at annual to sub-annual resolution that can extend the marine instrumental record is therefore a clear priority for marine climate science. The bivalve species Arctica islandica is a unique paleoclimatic archive with an exceptional longevity combined with high temporal resolution, due to accretion of annual growth increments. The aim of this study is to use sclerochronological records of A. islandica to extend instrumental hydrographic records and increase our understanding of a variability of a Norwegian Coastal Current (NCC). The NCC transports warm, low-salinity water northwards, which eventually plays role for the Arctic halocline. Moreover, previous investigations showed the connection of properties and variability of the NCC with catches of commercially valuable fishes. The knowledge of the variability of the NCC is also essential for possible future prediction climate conditions and fish stock variability in the region. In this study we use shells of Arctica islandica collected off the coast of Eggum (Lofoten, Norway). The material was obtained from the depth 5-10 m by dredging along the seabed and by means of scuba divers. We examine the growth patterns of living and subfossil shells. Ongoing work mainly focuses on the construction of a composite growth chronology based on increment-width time series. The results we will compare with existing time series of the environment and climatic parameters to determine the controlling factors and test the applicability of growth chronology in a climate reconstruction. Furthermore, we will perform geochemical analyses of the stable isotope composition (δ18O and δ13C) in shell carbonate to identify seasonal signals and reconstruct the surface water temperature on a sub-annual time-scale.

The Faces Symbol Test, a newly developed screening instrument to assess cognitive decline related to multiple sclerosis: first results of the Berlin Multi-Centre FST Validation Study.

PubMed

Scherer, P; Penner, I K; Rohr, A; Boldt, H; Ringel, I; Wilke-Burger, H; Burger-Deinerth, E; Isakowitsch, K; Zimmermann, M; Zahrnt, S; Hauser, R; Hilbert, K; Tiel-Wilck, K; Anvari, K; Behringer, A; Peglau, I; Friedrich, H; Plenio, A; Benesch, G; Ehret, R; Nippert, I; Finke, G; Schulz, I; Bergtholdt, B; Breitkopf, S; Kaskel, P; Reischies, F; Kugler, J

2007-04-01

Reliable, language-independent, short screening instruments to test for cognitive function in patients with multiple sclerosis (MS) remain rare, despite the high number of patients affected by cognitive decline. We developed a new, short screening instrument, the Faces Symbol Test (FST), and compared its diagnostic test characteristics with a composite of the Digit Symbol Substitution Test (DSST) and the Paced Auditory Serial Addition Test (PASAT), in 108 MS patients and 33 healthy controls. An Informant-Report Questionnaire, a Self-Report Questionnaire, and a neurologist's estimation of the Every Day Life Cognitive Status were also applied to the MS patients. The statistical analyses comprised of a receiver operating characteristic analysis for test accuracy and for confounding variables. The PASAT and DSST composite score estimated that 36.5% of the MS patients had cognitive impairment. The FST estimated that 40.7% of the MS patients were cognitively impaired (sensitivity 84%; specificity 85%). The FST, DSST and PASAT results were significantly correlated with the patients' physical impairment, as measured by the Expanded Disability Status Scale (EDSS). The results suggest that the FST might be a culture-free, sensitive, and practical short screening instrument for the detection of cognitive decline in patients with MS, including those in the early stages.

Analysis of altimeter data jointly with seafloor electric data (vertically integrated velocity) and VCTD-yoyo data (detailed profiles of VCTD)

NASA Technical Reports Server (NTRS)

Tarits, Pascal D.; Menvielle, M.; Provost, C.; Filloux, J. H.

1991-01-01

We propose simultaneous analyses of the TOPEX/POSEIDON altimetry data, in situ data--mainly permanent seafloor electric recordings--and velocity, conductivity, temperature, density (VCTD)-yoyo data at several stations in areas of scientific interest. We are planning experiments in various areas of low and high energy levels. Several complementary and redundant methods will be used to characterize the ocean circulation and its short- and long-term variability. We shall emphasize long-term measurement using permanent stations. Our major initial objectives with the TOPEX/POSEIDON mission are the Confluence area in the Argentine Basin and the Circumpolar Antarctic Current. An early experiment was carried out in the Confluence zone in 1988 and 1990 (Confluence Principal Investigators, 1990) to prepare for an intensive phase later one. This intensive phase will include new types of instrumentation. Preliminary experiments will be carried out in the Mediterranean Sea (in 1991) and in the North Atlantic Ocean (in 1992, north of the Canary Islands) to test the new instrumentation.

Instrumental neutron activation analysis for studying size-fractionated aerosols

NASA Astrophysics Data System (ADS)

Salma, Imre; Zemplén-Papp, Éva

1999-10-01

Instrumental neutron activation analysis (INAA) was utilized for studying aerosol samples collected into a coarse and a fine size fraction on Nuclepore polycarbonate membrane filters. As a result of the panoramic INAA, 49 elements were determined in an amount of about 200-400 μg of particulate matter by two irradiations and four γ-spectrometric measurements. The analytical calculations were performed by the absolute ( k0) standardization method. The calibration procedures, application protocol and the data evaluation process are described and discussed. They make it possible now to analyse a considerable number of samples, with assuring the quality of the results. As a means of demonstrating the system's analytical capabilities, the concentration ranges, median or mean atmospheric concentrations and detection limits are presented for an extensive series of aerosol samples collected within the framework of an urban air pollution study in Budapest. For most elements, the precision of the analysis was found to be beyond the uncertainty represented by the sampling techniques and sample variability.

Effects of rainfall partitioning in the seasonal and spatial variability of soil water content in a Mediterranean downy oak forest

NASA Astrophysics Data System (ADS)

Garcia-Estringana, P.; Latron, J.; Molina, A. J.; Llorens, P.

2012-04-01

Rainfall partitioning fluxes (throughfall and stemflow) have a large degree of temporal and spatial variability and may consequently lead to significant changes in the volume and composition of water that reach the understory and the soil. The objective of this work is to study the effect of rainfall partitioning on the seasonal and spatial variability of the soil water content in a Mediterranean downy oak forest (Quercus pubescens), located in the Vallcebre research catchments (42° 12'N, 1° 49'E). The monitoring design, started on July 2011, consists of a set of 20 automatic rain recorders and 40 automatic soil moisture probes located below the canopy. One hundred hemispheric photographs of the canopy were used to place the instruments at representative locations (in terms of canopy cover) within the plot. Bulk rainfall, stemflow and meteorological conditions above the forest cover are also automatically recorded. Canopy cover, in leaf and leafless periods, as well as biometric characteristics of the plot, are also regularly measured. This work presents the first results describing throughfall and soil moisture spatial variability during both the leaf and leafless periods. The main drivers of throughfall variability, as canopy structure and meteorological conditions are also analysed.

Genetic markers as instrumental variables.

PubMed

von Hinke, Stephanie; Davey Smith, George; Lawlor, Debbie A; Propper, Carol; Windmeijer, Frank

2016-01-01

The use of genetic markers as instrumental variables (IV) is receiving increasing attention from economists, statisticians, epidemiologists and social scientists. Although IV is commonly used in economics, the appropriate conditions for the use of genetic variants as instruments have not been well defined. The increasing availability of biomedical data, however, makes understanding of these conditions crucial to the successful use of genotypes as instruments. We combine the econometric IV literature with that from genetic epidemiology, and discuss the biological conditions and IV assumptions within the statistical potential outcomes framework. We review this in the context of two illustrative applications. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Statistical Analysis for Multisite Trials Using Instrumental Variables with Random Coefficients

ERIC Educational Resources Information Center

Raudenbush, Stephen W.; Reardon, Sean F.; Nomi, Takako

2012-01-01

Multisite trials can clarify the average impact of a new program and the heterogeneity of impacts across sites. Unfortunately, in many applications, compliance with treatment assignment is imperfect. For these applications, we propose an instrumental variable (IV) model with person-specific and site-specific random coefficients. Site-specific IV…

Job demands and job strain as risk factors for employee wellbeing in elderly care: an instrumental-variables analysis.

PubMed

Elovainio, Marko; Heponiemi, Tarja; Kuusio, Hannamaria; Jokela, Markus; Aalto, Anna-Mari; Pekkarinen, Laura; Noro, Anja; Finne-Soveri, Harriet; Kivimäki, Mika; Sinervo, Timo

2015-02-01

The association between psychosocial work environment and employee wellbeing has repeatedly been shown. However, as environmental evaluations have typically been self-reported, the observed associations may be attributable to reporting bias. Applying instrumental-variable regression, we used staffing level (the ratio of staff to residents) as an unconfounded instrument for self-reported job demands and job strain to predict various indicators of wellbeing (perceived stress, psychological distress and sleeping problems) among 1525 registered nurses, practical nurses and nursing assistants working in elderly care wards. In ordinary regression, higher self-reported job demands and job strain were associated with increased risk of perceived stress, psychological distress and sleeping problems. The effect estimates for the associations of these psychosocial factors with perceived stress and psychological distress were greater, but less precisely estimated, in an instrumental-variables analysis which took into account only the variation in self-reported job demands and job strain that was explained by staffing level. No association between psychosocial factors and sleeping problems was observed with the instrumental-variable analysis. These results support a causal interpretation of high self-reported job demands and job strain being risk factors for employee wellbeing. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Pilot testing model to uncover industrial symbiosis in Brazilian industrial clusters.

PubMed

Saraceni, Adriana Valélia; Resende, Luis Mauricio; de Andrade Júnior, Pedro Paulo; Pontes, Joseane

2017-04-01

The main objective of this study was to create a pilot model to uncover industrial symbiosis practices in Brazilian industrial clusters. For this purpose, a systematic revision was conducted in journals selected from two categories of the ISI Web of Knowledge: Engineering, Environmental and Engineering, Industrial. After an in-depth revision of literature, results allowed the creation of an analysis structure. A methodology based on fuzzy logic was applied and used to attribute the weights of industrial symbiosis variables. It was thus possible to extract the intensity indicators of the interrelations required to analyse the development level of each correlation between the variables. Determination of variables and their weights initially resulted in a framework for the theory of industrial symbiosis assessments. Research results allowed the creation of a pilot model that could precisely identify the loopholes or development levels in each sphere. Ontology charts for data analysis were also generated. This study contributes to science by presenting the foundations for building an instrument that enables application and compilation of the pilot model, in order to identify opportunity to symbiotic development, which derives from "uncovering" existing symbioses.

UFO-a multi-analyser option for IN12

NASA Astrophysics Data System (ADS)

Schmidt, Wolfgang; Rheinstädter, Maikel C.; Raymond, Stephane; Ohl, Michael

2004-07-01

The IN12 instrument is operated by FZ Jülich in collaboration with CEA Grenoble as a CRG-B instrument at the Institut Laue Langevin in Grenoble. As a three-axis spectrometer for cold neutrons it is dedicated for high-resolution studies of low-energy excitations. In the past years the instrument has been continuously improved and it has demonstrated its excellent performance for neutron scattering research. To meet further challenges as a state-of-the-art instrument in the next funding period we will propose to upgrade IN12 with a multi-analyser option similar to planned or existing RITA-type instruments. IN12 will then be optionally equipped with an array of individual analyser blades which can be positioned separately in order to map the scattered beam on a user-chosen path in (Q,ω)-space. We refer to this set-up as IN12-UFO (universal focusing option). Both, the feasibility and the scientific case are currently being studied. On the conference we will show details of the planned instrumental set-up and demonstrate its flexibility and multiplex advantages for specific physical applications.

The Early Memories of Warmth and Safeness Scale for adolescents: Cross-Sample Validation of the Complete and Brief Versions.

PubMed

Vagos, Paula; Ribeiro da Silva, Diana; Brazão, Nélio; Rijo, Daniel; Gilbert, Paul

2017-05-01

This work presents psychometric analyses on the Early Memories of Warmth and Safeness Scale, which intends to evaluate the subjective perception of ones' early rearing experiences. Factor structure, measurement invariance, latent mean comparisons and validity in relation to external variables (i.e., forms of self-criticism/self-assurance, experiential avoidance and depressive, anxious and stress symptoms) were investigated. A sample of 1464 adolescents (52.3% male adolescents, mean age = 16.16, standard deviation = 1.51) was used, including 1064 participants recruited from schools, 192 participants recruited from foster care facilities and 208 boys recruited from juvenile justice facilities. A shortened version of the scale was also developed and subjected to the same psychometric analyses. A one-factor measurement model was a good fit for the data taken from both the complete and brief versions of the instrument. Such measures showed to be internally consistent with alpha values higher than 0.89. Evidence for their construct validity in relation to external variables was also found, with correlation values ranging from 0.19 to 0.45 for the complete version and from 0.18 to 0.44 for the brief version of the instrument. The brief version was the only one proving to be gender and sample invariant. Boys and girls scored similarly in their account of early memories, whereas community boys presented significantly higher scores when compared with referred and detained boys. Thus, the brief version of the instrument may be an appropriate alternative for use with diverse adolescent samples and may serve to advance knowledge on how early experiences impact on psychopathological outcomes. Copyright © 2016 John Wiley & Sons, Ltd. The Early Memories of Warmth and Safeness Scale (EMWSS), assessing early memories of warmth and safeness, was studied across community, referred for behavioural problems and detained Portuguese adolescent samples. A brief version of this instrument was also developed and studied in these same samples. Both versions of the EMWSS revealed a one-factor structure, good internal consistency and construct validity in relation to external variables; the brief version was also found to be invariant across gender and groups. Boys and girls were found to report similar levels of experienced warmth and safeness, whereas community boys reported significantly more of those experiences, followed by detained boys, and, lastly, referred boys. The brief version of the EMWSS represents a quick and valid measure to assess early memories of warmth and safeness in youth, providing for insights into the subjective experience of adolescents with diverse rearing experiences. Early memories of warmth and safeness, as assessed by the brief version of the EMWSS, may serve to advance knowledge on how early experiences impact on psychopathological outcomes in diverse youth samples. Copyright © 2016 John Wiley & Sons, Ltd.

SonTek SL3G Side-Looking Doppler Current Meter application in Complex Flow Conditions

NASA Astrophysics Data System (ADS)

Wagenaar, D.

2014-12-01

The SonTek Argonaut SL Side-Looking Doppler Current Meters are well established products in the measurement of real-time water velocity in open channels. With the development of acoustic doppler technology the decision was made to incorporate latest technology in the Argonaut SL and hence the SonTek SL3G was born.The SonTek SL3G Acoustic Doppler instrument incorporates a number of innovations that improves velocity measurements and quality assurance of data for Side-Looking Doppler Current Meters. SmartPulseHD was originally introduced with the launch of the SonTek M9/S5 RiverSurveyor Acoustic Doppler Instruments and the increased accuracy and resolution of velocity measurements made it obvious to include into the new SL3G instruments. SmartPulseHD continuously tracks the water conditions and selects the optimum processing configuration required using multiple ping types and processing techniques. The new SL3G design makes it the smallest Side Looking Acoustic Doppler Velocity Meter on the market reducing flow disturbance caused by the instrument and the distance of first measurement cell from boundary.The application of the SL3G Acoustic Doppler instrument is designed for complex flow conditions where the use of conventional stage-discharge relationships is economically not viable and therefore requires the use of velocity index methodology. The case-study presented in this paper is situated in the Colorado River downstream of Imperial Dam affected by controlled releases, drainage from adjacent irrigation areas and backwater from a weir situated downstream of the monitoring site. The paper analyses the relationship between measured mean velocity and index velocity and if additional variables such as stage and or Y-velocity need to be incorporated in the development of the index velocity rating. In addition, to determine the variables impacting on the index velocity rating, the index velocity applied will be evaluated by the best linear relationship between the multi-cell and integrated cell index velocities and measured mean velocities.The data presented in this paper shows that the physical design and features of the new SonTek SL3G instrument enables the user to accurately measure real time discharge information in complex flow conditions based on index velocity rating principles.

Prediction of future falls in a community dwelling older adult population using instrumented balance and gait analysis.

PubMed

Bauer, C M; Gröger, I; Rupprecht, R; Marcar, V L; Gaßmann, K G

2016-04-01

The role of instrumented balance and gait assessment when screening for prospective fallers is currently a topic of controversial discussion. This study analyzed the association between variables derived from static posturography, instrumented gait analysis and clinical assessments with the occurrence of prospective falls in a sample of community dwelling older people. In this study 84 older people were analyzed. Based on a prospective occurrence of falls, participants were categorized into fallers and non-fallers. Variables derived from clinical assessments, static posturography and instrumented gait analysis were evaluated with respect to the association with the occurrence of prospective falls using a forward stepwise, binary, logistic regression procedure. Fallers displayed a significantly shorter single support time during walking while counting backwards, increased mediolateral to anteroposterior sway amplitude ratio, increased fast mediolateral oscillations and a larger coefficient (Coeff) of sway direction during various static posturography tests. Previous falls were insignificantly associated with the occurrence of prospective falls. Variables derived from posturography and instrumented gait analysis showed significant associations with the occurrence of prospective falls in a sample of community dwelling older adults.

Influence of canopy traits on spatio-temporal variability of throughfall in Mediterranean Downy oak and Scots pine stands

NASA Astrophysics Data System (ADS)

Llorens, Pilar; Garcia-Estringana, Pablo; Latron, Jérôme; Molina, Antonio J.; Gallart, Francesc

2014-05-01

The spatio-temporal variability of throughfall is the result of the interaction of biotic factors, related to the canopy traits, and abiotic factors, linked to the meteorological conditions. This variability may lead to significant differences in the volume of water and solutes that reach the ground in each location, and beyond in the hydrological and biogeochemical dynamics of forest soils. Two forest stands in Mediterranean climatic conditions were studied to analyse the role of biotic and abiotic factors in the temporal and spatial redistribution of throughfall. The monitored stands are a Downy oak forest (Quercus pubescens) and a Scots pine forest (Pinus sylvestris), both located in the Vallcebre research catchments (NE Spain, 42º 12'N, 1º 49'E). The study plots are representative of Mediterranean mountain areas with spontaneous afforestation by Scots pine as a consequence of the abandonment of agricultural terraces, formerly covered by Downy oaks. The monitoring design of each plot consisted of a set of 20 automatic rain recorders and 40 automatic soil moisture probes located below the canopy. 100 hemispheric photographs of the canopy were used to place the instruments at representative locations (in terms of canopy cover) within the plot. Bulk rainfall, stemflow and meteorological conditions above the forest cover were also automatically recorded. Canopy cover as well as biometric characteristics of the plots were also regularly measured. The results indicate a temporal persistence of throughfall in both stands, as observed elsewhere. However, for the oak plot the seasonal evolution of canopy traits added additional variability, with higher variability in summer and different locations of wet and dry spots depending on the season. Furthermore, this work investigates the influence of canopy structure on the spatial variability of throughfall by analysing a large set of forest parameters, from main canopy traits to detailed leaves and wood characteristics. The analysis includes the consideration of the interaction of main abiotic factors with canopy traits.

Development and validation of classifiers and variable subsets for predicting nursing home admission.

PubMed

Nuutinen, Mikko; Leskelä, Riikka-Leena; Suojalehto, Ella; Tirronen, Anniina; Komssi, Vesa

2017-04-13

In previous years a substantial number of studies have identified statistically important predictors of nursing home admission (NHA). However, as far as we know, the analyses have been done at the population-level. No prior research has analysed the prediction accuracy of a NHA model for individuals. This study is an analysis of 3056 longer-term home care customers in the city of Tampere, Finland. Data were collected from the records of social and health service usage and RAI-HC (Resident Assessment Instrument - Home Care) assessment system during January 2011 and September 2015. The aim was to find out the most efficient variable subsets to predict NHA for individuals and validate the accuracy. The variable subsets of predicting NHA were searched by sequential forward selection (SFS) method, a variable ranking metric and the classifiers of logistic regression (LR), support vector machine (SVM) and Gaussian naive Bayes (GNB). The validation of the results was guaranteed using randomly balanced data sets and cross-validation. The primary performance metrics for the classifiers were the prediction accuracy and AUC (average area under the curve). The LR and GNB classifiers achieved 78% accuracy for predicting NHA. The most important variables were RAI MAPLE (Method for Assigning Priority Levels), functional impairment (RAI IADL, Activities of Daily Living), cognitive impairment (RAI CPS, Cognitive Performance Scale), memory disorders (diagnoses G30-G32 and F00-F03) and the use of community-based health-service and prior hospital use (emergency visits and periods of care). The accuracy of the classifier for individuals was high enough to convince the officials of the city of Tampere to integrate the predictive model based on the findings of this study as a part of home care information system. Further work need to be done to evaluate variables that are modifiable and responsive to interventions.

A new model of wheezing severity in young children using the validated ISAAC wheezing module: A latent variable approach with validation in independent cohorts.

PubMed

Brunwasser, Steven M; Gebretsadik, Tebeb; Gold, Diane R; Turi, Kedir N; Stone, Cosby A; Datta, Soma; Gern, James E; Hartert, Tina V

2018-01-01

The International Study of Asthma and Allergies in Children (ISAAC) Wheezing Module is commonly used to characterize pediatric asthma in epidemiological studies, including nearly all airway cohorts participating in the Environmental Influences on Child Health Outcomes (ECHO) consortium. However, there is no consensus model for operationalizing wheezing severity with this instrument in explanatory research studies. Severity is typically measured using coarsely-defined categorical variables, reducing power and potentially underestimating etiological associations. More precise measurement approaches could improve testing of etiological theories of wheezing illness. We evaluated a continuous latent variable model of pediatric wheezing severity based on four ISAAC Wheezing Module items. Analyses included subgroups of children from three independent cohorts whose parents reported past wheezing: infants ages 0-2 in the INSPIRE birth cohort study (Cohort 1; n = 657), 6-7-year-old North American children from Phase One of the ISAAC study (Cohort 2; n = 2,765), and 5-6-year-old children in the EHAAS birth cohort study (Cohort 3; n = 102). Models were estimated using structural equation modeling. In all cohorts, covariance patterns implied by the latent variable model were consistent with the observed data, as indicated by non-significant χ2 goodness of fit tests (no evidence of model misspecification). Cohort 1 analyses showed that the latent factor structure was stable across time points and child sexes. In both cohorts 1 and 3, the latent wheezing severity variable was prospectively associated with wheeze-related clinical outcomes, including physician asthma diagnosis, acute corticosteroid use, and wheeze-related outpatient medical visits when adjusting for confounders. We developed an easily applicable continuous latent variable model of pediatric wheezing severity based on items from the well-validated ISAAC Wheezing Module. This model prospectively associates with asthma morbidity, as demonstrated in two ECHO birth cohort studies, and provides a more statistically powerful method of testing etiologic hypotheses of childhood wheezing illness and asthma.

Post-instrumentation pain after the use of either Mtwo or the SAF system: a randomized controlled clinical trial.

PubMed

Saumya-Rajesh, P; Krithikadatta, J; Velmurugan, N; Sooriaprakas, C

2017-08-01

This randomized controlled trial compared the incidence of post-instrumentation pain associated with Mtwo rotary NiTi files and the self-adjusting file system following canal shaping and cleaning. Following sample size estimation, a total of 130 patients were randomized into two groups based on selection criteria [group Mtwo and group SAF (self-adjusting file)]. Root canal treatment was carried out in two appointments. The teeth were endodontically treated with the appropriate allotted systems following the similar clinical parameters. Patients were asked to rate the intensity of pre-instrumentation and post-instrumentation pain (at 2, 4, 6, 8, 24, 48 h) using the VAS score. The Kruskal-Wallis test was carried out for the overall comparisons of the two systems. The Friedman test was used to compare between time-points with each system. Subgroup analyses for independent variables (gender, pulp status and diagnosis) used the Mann-Whitney test and Wilcoxon signed ranks test (P < 0.05). No significant difference was found between the two groups with respect to post-instrumentation pain. Teeth with pulpal necrosis had significant pain at 8 h compared with teeth with vital pulps (P = 0.04). Teeth with vital pulps in the SAF group had significantly less post-instrumentation pain compared with those in the Mtwo group at 6 h (P = 0.042). Patients who had teeth with nonvital pulps in the SAF group experienced more post-instrumentation pain at 8 h (P = 0.017) and 24 h (P = 0.005). The incidence of post-instrumentation pain at different time intervals in patients undergoing root canal treatment was similar for both the self-adjusting file and Mtwo file systems. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Randomized controlled trial of a messaging intervention to increase fruit and vegetable intake in adolescents: Affective versus instrumental messages.

PubMed

Carfora, Valentina; Caso, Daniela; Conner, Mark

2016-11-01

The present research aimed to test the efficacy of affective and instrumental text messages compared with a no-message control as a strategy to increase fruit and vegetable intake (FVI) in adolescents. A randomized controlled trial was used test impact of different text messages compared with no message on FVI over a 2-week period. A total of 1,065 adolescents (14-19 years) from a high school of the South of Italy completed the baseline questionnaire and were randomly allocated to one of three conditions: instrumental messages (N = 238), affective messages (N = 300), and no messages (N = 521). Students in the message conditions received one message each day over a 2-week period. The messages targeted affective (affective benefits) or instrumental (instrumental benefits) information about FVI. Self-reported FVI at 2 weeks was the key dependent variable. Analyses were based on the N = 634 who completed all aspects of the study. Findings showed that messages significantly increased FVI, particularly in the affective condition and this effect was partially mediated by changes in affective attitude and intentions towards FVI. Text messages can be used to increase FVI in adolescents. Text messages based on affective benefits are more effective than text messages based on instrumental benefits. Statement of contribution What is already known on this subject? Text messages have been shown to promote positive change in health behaviours. However, the most appropriate target for such text messages is less clear although targeting attitudes may be effective. What does this study add? This randomized controlled study shows that text messages targeting instrumental or affective attitudes produce changes in fruit and vegetable intake (FVI) in adolescents. Text messages targeting affective attitudes are shown to be more effective than text messages targeting instrumental attitudes. The effect of affective text messages on FVI was partially mediated by changes in affective attitudes. © 2016 The British Psychological Society.

PACIC Instrument: disentangling dimensions using published validation models.

PubMed

Iglesias, K; Burnand, B; Peytremann-Bridevaux, I

2014-06-01

To better understand the structure of the Patient Assessment of Chronic Illness Care (PACIC) instrument. More specifically to test all published validation models, using one single data set and appropriate statistical tools. Validation study using data from cross-sectional survey. A population-based sample of non-institutionalized adults with diabetes residing in Switzerland (canton of Vaud). French version of the 20-items PACIC instrument (5-point response scale). We conducted validation analyses using confirmatory factor analysis (CFA). The original five-dimension model and other published models were tested with three types of CFA: based on (i) a Pearson estimator of variance-covariance matrix, (ii) a polychoric correlation matrix and (iii) a likelihood estimation with a multinomial distribution for the manifest variables. All models were assessed using loadings and goodness-of-fit measures. The analytical sample included 406 patients. Mean age was 64.4 years and 59% were men. Median of item responses varied between 1 and 4 (range 1-5), and range of missing values was between 5.7 and 12.3%. Strong floor and ceiling effects were present. Even though loadings of the tested models were relatively high, the only model showing acceptable fit was the 11-item single-dimension model. PACIC was associated with the expected variables of the field. Our results showed that the model considering 11 items in a single dimension exhibited the best fit for our data. A single score, in complement to the consideration of single-item results, might be used instead of the five dimensions usually described. © The Author 2014. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

A cross-sectional survey on consequences of nurses' burnout: moderating role of organizational politics.

PubMed

Basar, Ufuk; Basim, Nejat

2016-08-01

The aim of the study was to assess whether perceptions of organizational politics (defined as self-serving behaviours at the expense of others) influence the prospective associations between nurses' burnout and its consequences, namely, intention to quit and neglect of work. Researchers have previously investigated relationships between nurses' burnout, intention to quit, neglect of work and perceptions of organizational politics in different research models and from different perspectives. As far as we know, no studies have considered whether nurses' perceptions of organizational politics moderate the influence of burnout. A cross-sectional survey using self-report questionnaires. Data were collected by questionnaire from a sample of 456 nurses from six private hospitals in Ankara, Turkey in March 2015. Four different previously designed scales were used to measure research variables (burnout, intention to quit, neglect of work and perceptions of organizational politics). Following confirmatory validity and reliability analyses of data collection instruments, descriptive statistics for each research variable were analysed. Structural regression models were created to assess relationships among variables. Burnout resulted in intention to quit and neglect. Intention to quit partially mediated the association between burnout and neglect. Burnout gave rise to intention to quit slightly more strongly in nurses who had greater perceptions of organizational politics. This study uncovers and emphasizes the moderating role of perceptions of organizational politics in consequences of burnout. This may help hospital managers and nurses to improve costs, efficiency, satisfaction and productivity. © 2016 John Wiley & Sons Ltd.

Personality Domains, Duration of Untreated Psychosis, Functioning, and Symptom Severity in First-Episode Psychosis

PubMed Central

Compton, Michael T.; Bakeman, Roger; Alolayan, Yazeed; Balducci, Pierfrancesco Maria; Bernardini, Francesco; Broussard, Beth; Crisafio, Anthony; Cristofaro, Sarah; Amar, Patrick; Johnson, Stephanie; Wan, Claire Ramsay

2015-01-01

Objectives Early-course psychotic disorders have been extensively studied in terms of phenomenology, but little is known about the influence of personality traits on clinical features of first-episode psychosis. The aim of this study was to explore how the “big five” personality domains (neuroticism, extraversion, openness, agreeableness, and conscientiousness) are associated with treatment delay (duration of untreated psychosis, DUP), functioning, and positive and negative symptom severity. Methods Data for these analyses were obtained from 104 participants enrolled from psychiatric inpatient units in Atlanta, Georgia, between August 2008 and March 2011. The NEO Five-Factor Inventory (NEO-FFI) was used to assess personality domains, and all other variables were measured in a standardized and rigorous manner using psychometrically sound instruments. Correlational analyses and multiple linear regressions were carried out to examine the strength of associations between variables of interest. Results Findings indicated that except for openness, all the other personality variables contributed to some extent to the variance in DUP. Conscientiousness was positively correlated with functioning. Agreeableness was independently negatively associated with positive symptom severity and extraversion was independently negatively correlated with negative symptom severity. Conclusions We report the first evidence suggesting that DUP is in part driven by personality domains. Functioning and symptom severity are also associated with those domains. Personality should be taken into account in order to better understand the phenomenology of early-course psychotic disorders as well as treatment-seeking behaviors. PMID:26209478

Robust best linear estimator for Cox regression with instrumental variables in whole cohort and surrogates with additive measurement error in calibration sample

PubMed Central

Wang, Ching-Yun; Song, Xiao

2017-01-01

SUMMARY Biomedical researchers are often interested in estimating the effect of an environmental exposure in relation to a chronic disease endpoint. However, the exposure variable of interest may be measured with errors. In a subset of the whole cohort, a surrogate variable is available for the true unobserved exposure variable. The surrogate variable satisfies an additive measurement error model, but it may not have repeated measurements. The subset in which the surrogate variables are available is called a calibration sample. In addition to the surrogate variables that are available among the subjects in the calibration sample, we consider the situation when there is an instrumental variable available for all study subjects. An instrumental variable is correlated with the unobserved true exposure variable, and hence can be useful in the estimation of the regression coefficients. In this paper, we propose a nonparametric method for Cox regression using the observed data from the whole cohort. The nonparametric estimator is the best linear combination of a nonparametric correction estimator from the calibration sample and the difference of the naive estimators from the calibration sample and the whole cohort. The asymptotic distribution is derived, and the finite sample performance of the proposed estimator is examined via intensive simulation studies. The methods are applied to the Nutritional Biomarkers Study of the Women’s Health Initiative. PMID:27546625

Nonparametric instrumental regression with non-convex constraints

NASA Astrophysics Data System (ADS)

Grasmair, M.; Scherzer, O.; Vanhems, A.

2013-03-01

This paper considers the nonparametric regression model with an additive error that is dependent on the explanatory variables. As is common in empirical studies in epidemiology and economics, it also supposes that valid instrumental variables are observed. A classical example in microeconomics considers the consumer demand function as a function of the price of goods and the income, both variables often considered as endogenous. In this framework, the economic theory also imposes shape restrictions on the demand function, such as integrability conditions. Motivated by this illustration in microeconomics, we study an estimator of a nonparametric constrained regression function using instrumental variables by means of Tikhonov regularization. We derive rates of convergence for the regularized model both in a deterministic and stochastic setting under the assumption that the true regression function satisfies a projected source condition including, because of the non-convexity of the imposed constraints, an additional smallness condition.

Dynamic modal estimation using instrumental variables

NASA Technical Reports Server (NTRS)

Salzwedel, H.

1980-01-01

A method to determine the modes of dynamical systems is described. The inputs and outputs of a system are Fourier transformed and averaged to reduce the error level. An instrumental variable method that estimates modal parameters from multiple correlations between responses of single input, multiple output systems is applied to estimate aircraft, spacecraft, and off-shore platform modal parameters.

Teachers' Pedagogical Management and Instrumental Performance in Students of an Artistic Higher Education School

ERIC Educational Resources Information Center

De La Cruz Bautista, Edwin

2017-01-01

This research aims to know the relationship between the variables teachers' pedagogical management and instrumental performance in students from an Artistic Higher Education School. It is a descriptive and correlational research that seeks to find the relationship between both variables. The sample of the study consisted of 30 students of the…

Polychronometry: The Study of Time Variables in Behavior.

ERIC Educational Resources Information Center

Mackey, William Francis

There is a growing need for instrumentation which can enable us to observe and compute phenomena that take place in time. Although problems of observation, computation, interpretation and categorization vary from field to field and from problem to problem, it is possible to design an instrument for use in any situation where time-variables have to…

Predicting Preservice Music Teachers' Performance Success in Instrumental Courses Using Self-Regulated Study Strategies and Predictor Variables

ERIC Educational Resources Information Center

Ersozlu, Zehra N.; Nietfeld, John L.; Huseynova, Lale

2017-01-01

The purpose of this study was to examine the extent to which self-regulated study strategies and predictor variables predict performance success in instrumental performance college courses. Preservice music teachers (N = 123) from a music education department in two state universities in Turkey completed the Music Self-Regulated Studying…

Can Two Psychotherapy Process Measures Be Dependably Rated Simultaneously? A Generalizability Study

ERIC Educational Resources Information Center

Ulvenes, Pal G.; Berggraf, Lene; Hoffart, Asle; Levy, Raymon A.; Ablon, J. Stuart; McCullough, Leigh; Wampold, Bruce E.

2012-01-01

Observer ratings in psychotherapy are a common way of collecting information in psychotherapy research. However, human observers are imperfect instruments, and their ratings may be subject to variability from several sources. One source of variability can be raters' assessing more than 1 instrument at a time. The purpose of this research is to…

Streamflow variability in the Chilean Temperate-Mediterranean climate transition (35°S-42°S) during the last 400 years inferred from tree-ring records

NASA Astrophysics Data System (ADS)

Muñoz, Ariel A.; González-Reyes, Alvaro; Lara, Antonio; Sauchyn, David; Christie, Duncan; Puchi, Paulina; Urrutia-Jalabert, Rocío; Toledo-Guerrero, Isadora; Aguilera-Betti, Isabella; Mundo, Ignacio; Sheppard, Paul R.; Stahle, Daniel; Villalba, Ricardo; Szejner, Paul; LeQuesne, Carlos; Vanstone, Jessica

2016-12-01

As rainfall in South-Central Chile has decreased in recent decades, local communities and industries have developed an understandable concern about their threatened water supply. Reconstructing streamflows from tree-ring data has been recognized as a useful paleoclimatic tool in providing long-term perspectives on the temporal characteristics of hydroclimate systems. Multi-century long streamflow reconstructions can be compared to relatively short instrumental observations in order to analyze the frequency of low and high water availability through time. In this work, we have developed a Biobío River streamflow reconstruction to explore the long-term hydroclimate variability at the confluence of the Mediterranean-subtropical and the Temperate-humid climate zones, two regions represented by previous reconstructions of the Maule and Puelo Rivers, respectively. In a suite of analyses, the Biobío River reconstruction proves to be more similar to the Puelo River than the Maule River, despite its closer geographic proximity to the latter. This finding corroborates other studies with instrumental data that identify 37.5°S as a latitudinal confluence of two climate zones. The analyzed rivers are affected by climate forcings on interannual and interdecadal time-scales, Tropical (El Niño Southern Oscillation) and Antarctic (Southern Annular Mode; SAM). Longer cycles found, around 80-years, are well correlated only with SAM variation, which explains most of the variance in the Biobío and Puelo rivers. This cycle also has been attributed to orbital forcing by other authors. All three rivers showed an increase in the frequency of extreme high and low flow events in the twentieth century. The most extreme dry and wet years in the instrumental record (1943-2000) were not the most extreme of the past 400-years reconstructed for the three rivers (1600-2000), yet both instrumental record years did rank in the five most extreme of the streamflow reconstructions as a whole. These findings suggest a high level of natural variability in the hydro-climatic conditions of the region, where extremes characterized the twentieth century. This information is particularly useful when evaluating and improving a wide variety of water management models that apply to water resources that are sensitive to agricultural and hydropower industries.

Physical Therapy as the First Point of Care to Treat Low Back Pain: An Instrumental Variables Approach to Estimate Impact on Opioid Prescription, Health Care Utilization, and Costs.

PubMed

Frogner, Bianca K; Harwood, Kenneth; Andrilla, C Holly A; Schwartz, Malaika; Pines, Jesse M

2018-05-23

To compare differences in opioid prescription, health care utilization, and costs among patients with low back pain (LBP) who saw a physical therapist (PT) at the first point of care, at any time during the episode or not at all. Commercial health insurance claims data, 2009-2013. Retrospective analyses using two-stage residual inclusion instrumental variable models to estimate rates for opioid prescriptions, imaging services, emergency department visits, hospitalization, and health care costs. Patients aged 18-64 years with a new primary diagnosis of LBP, living in the northwest United States, were observed over a 1-year period. Compared to patients who saw a PT later or never, patients who saw a PT first had lower probability of having an opioid prescription (89.4 percent), any advanced imaging services (27.9 percent), and an Emergency Department visit (14.7 percent), yet 19.3 percent higher probability of hospitalization (all p < .001). These patients also had significantly lower out-of-pocket costs, and costs appeared to shift away from outpatient and pharmacy toward provider settings. When LBP patients saw a PT first, there was lower utilization of high-cost medical services as well as lower opioid use, and cost shifts reflecting the change in utilization. © Health Research and Educational Trust.

High-Precision Studies of Compact Variable Stars

NASA Astrophysics Data System (ADS)

Bloemen, Steven

2014-10-01

This book, which is a reworked and updated version of Steven Bloemen's original PhD thesis, reports on several high-precision studies of compact variable stars. Its strength lies in the large variety of observational, theoretical and instrumentation techniques that are presented and used and paves the way towards new and detailed asteroseismic applications of single and binary subdwarf stars. Close binary stars are studied using high cadence spectroscopic datasets collected with state of the art electron multiplying CCDs and analysed using Doppler tomography visualization techniques. The work touches upon instrumentation, presenting the calibration of a new fast, multi-colour camera installed at the Mercator Telescope on La Palma. The thesis also includes theoretical work on the computation of the temperature range in which stellar oscillations can be driven in subdwarf B-stars. Finally, the highlight of the thesis is the measurement of velocities of stars using only photometric data from NASA's Kepler satellite. Doppler beaming causes stars to appear slightly brighter when they move towards us in their orbits, and this subtle effect can be seen in Kepler's brightness measurements. The thesis presents the first validation of such velocity measurements using independent spectroscopic measurements. Since the detection and validation of this Doppler beaming effect, it has been used in tens of studies to detect and characterize binary star systems, which are key calibrators in stellar astronomy.

Introduction of a new instrument to measure motivation for gaming: the electronic gaming motives questionnaire.

PubMed

Myrseth, Helga; Notelaers, Guy; Strand, Leif Åge; Borud, Einar Kristian; Olsen, Olav Kjellevold

2017-09-01

To adapt the four-dimensional Gambling Motives Questionnaire-Revised (GMQ-R) to measure the motivation for engaging in electronic gaming, and to validate the internal structure and investigate the criterion validity of the new Electronic Gaming Motives Questionnaire (EGMQ). The GMQ-R was adapted to measure motivation for playing video games and the new instrument was tested on a sample of Norwegian conscripts selected randomly from the pool of conscripts who started their military service between 2013 and 2015. The questionnaire was administered to all those who had played video games during the last 6 months and consisted of 853 gamers (86.8% men, mean age = 19.4 years). All participants completed the EGMQ, as well as other measures of gaming behaviour, gaming problems, boredom, loneliness and depression. The confirmatory factor analyses showed that the proposed EGMQ (measuring enhancement, coping, social and self-gratification motives) displayed satisfactory fit and internal consistency. Hierarchical regression analyses showed that gender emerged as a significant predictor (P < 0.001) of all the dependent variables (variety, hours weekly gaming, loss of control and gaming problems) and the first step explained between 1 and 6.1% of the variance in the gaming behaviours. In the second step the four motivational dimensions explained an additional 5.8-38.8% of the variance. Coping and self-gratification predicted gaming problems (P < 0.001) and coping alone predicted loss of control (P < 0.001). The four motivational dimensions were also predicted differentially by indicators of psychosocial wellbeing, indicating divergent validity of the four motives. The four-dimensional Electronic Gaming Motives Questionnaire is a valid instrument for measuring motives for gaming. © 2017 Society for the Study of Addiction.

Industrial Instrument Mechanic. Occupational Analyses Series.

ERIC Educational Resources Information Center

Dean, Ann; Zagorac, Mike; Bumbaka, Nick

This analysis covers tasks performed by an industrial instrument mechanic, an occupational title some provinces and territories of Canada have also identified as industrial instrumentation and instrument mechanic. A guide to analysis discusses development, structure, and validation method; scope of the occupation; trends; and safety. To facilitate…

Merging Old and New: An Instrumentation-Based Introductory Analytical Laboratory

ERIC Educational Resources Information Center

Jensen, Mark B.

2015-01-01

An instrumentation-based laboratory curriculum combining traditional unknown analyses with student-designed projects has been developed for an introductory analytical chemistry course. In the first half of the course, students develop laboratory skills and instrumental proficiency by rotating through six different instruments performing…

Integrated Data Collection Analysis (IDCA) Program - Statistical Analysis of RDX Standard Data Sets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.

2015-10-30

The Integrated Data Collection Analysis (IDCA) program is conducting a Proficiency Test for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are statistical analyses of the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of the RDX Type II Class 5 standard. The material was tested as a well-characterized standard several times during the proficiency study to assess differences among participants and the range of results that may arise for well-behaved explosive materials. The analyses show that there are detectable differences among the results from IDCA participants. While these differences are statisticallymore » significant, most of them can be disregarded for comparison purposes to assess potential variability when laboratories attempt to measure identical samples using methods assumed to be nominally the same. The results presented in this report include the average sensitivity results for the IDCA participants and the ranges of values obtained. The ranges represent variation about the mean values of the tests of between 26% and 42%. The magnitude of this variation is attributed to differences in operator, method, and environment as well as the use of different instruments that are also of varying age. The results appear to be a good representation of the broader safety testing community based on the range of methods, instruments, and environments included in the IDCA Proficiency Test.« less

[Evaluation of traditional German undergraduate surgical training. An analysis at Heidelberg University].

PubMed

Schürer, S; Schellberg, D; Schmidt, J; Kallinowski, F; Mehrabi, A; Herfarth, Ch; Büchler, M W; Kadmon, M

2006-04-01

The medical faculty of Heidelberg University implemented a new problem-based clinical curriculum (Heidelberg Curriculum Medicinale, or Heicumed) in 2001. The present study analyses the evaluation data of two student cohorts prior to the introduction of Heicumed. Its aim was to specify problems of the traditional training and to draw conclusions for implementation of a new curriculum. The evaluation instrument was the Heidelberg Inventory for the Evaluation of Teaching (HILVE-I). The data were analysed calculating differences in the means between defined groups, with the 13 primary scales of the HILVE I-instrument as dependent variables. Teaching method and subject had no systematic influence on evaluation results. Thus, didactic lecture in orthopedic surgery achieved better results than small group tutorials, while the data on vascular and general surgery showed opposite results. Major factors for success were continuity and didactic training of lecturers and tutors. This is convincingly reflected by the results of the lecture course "Differential diagnosis in general surgery". The good evaluation data on small group tutorials resulted largely from the "participation" and "discussion" scales, which represent interactivity in learning. The results of the present study suggest the importance of two major pedagogic ideas: continuity and didactic training of lecturers and tutors. These principles were widely implemented in Heicumed and have contributed to the success of the new curriculum.

Detection of greenhouse-gas-induced climatic change. Progress report, July 1, 1994--July 31, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, P.D.; Wigley, T.M.L.

1995-07-21

The objective of this research is to assembly and analyze instrumental climate data and to develop and apply climate models as a basis for detecting greenhouse-gas-induced climatic change, and validation of General Circulation Models. In addition to changes due to variations in anthropogenic forcing, including greenhouse gas and aerosol concentration changes, the global climate system exhibits a high degree of internally-generated and externally-forced natural variability. To detect the anthropogenic effect, its signal must be isolated from the ``noise`` of this natural climatic variability. A high quality, spatially extensive data base is required to define the noise and its spatial characteristics.more » To facilitate this, available land and marine data bases will be updated and expanded. The data will be analyzed to determine the potential effects on climate of greenhouse gas and aerosol concentration changes and other factors. Analyses will be guided by a variety of models, from simple energy balance climate models to coupled atmosphere ocean General Circulation Models. These analyses are oriented towards obtaining early evidence of anthropogenic climatic change that would lead either to confirmation, rejection or modification of model projections, and towards the statistical validation of General Circulation Model control runs and perturbation experiments.« less

Thermal Emission Variability of Zamama, Culann and Tupan on Io Using Galileo Near-Infrared Mapping Spectrometer (NIMS) Data

NASA Technical Reports Server (NTRS)

Ennis, M. E.; Davies, A. G.

2005-01-01

The Jovian satellite Io is the most volcanically active body in the Solar System. Previous analyses [e.g., 1-4] indicate the presence of high-temperature silicate volcanism on Io, similar to silicate volcanism occurring on Earth. Instruments onboard the Galileo spacecraft, especially the Near Infrared Mapping Spectrometer (NIMS) and the Solid State Imager (SSI), provided much data of Io s active volcanoes throughout the duration of the Galileo mission (June 1996-September 2003). NIMS data is particularly sensitive to thermal emission from active and cooling lava over cooling times of seconds to a few years. The objective of this ongoing study of Io s volcanism is to determine the variability of thermal emission from volcanoes on Io s surface, in order to better understand the styles of eruption, and to constrain the volumes of material erupted. Ultimately, this will help to constrain the contribution of active volcanism to Io s thermal budget. Data have been analyzed for the volcano Zamama, located at 173 W, 21 N, and the power output of Zamama, the volumes of lava being erupted, and the eruption rate determined. Culann and Tupan have also been analysed in this way. This abstract primarily concentrates on Zamama.

Latent transition analysis of pre-service teachers' efficacy in mathematics and science

NASA Astrophysics Data System (ADS)

Ward, Elizabeth Kennedy

This study modeled changes in pre-service teacher efficacy in mathematics and science over the course of the final year of teacher preparation using latent transition analysis (LTA), a longitudinal form of analysis that builds on two modeling traditions (latent class analysis (LCA) and auto-regressive modeling). Data were collected using the STEBI-B, MTEBI-r, and the ABNTMS instruments. The findings suggest that LTA is a viable technique for use in teacher efficacy research. Teacher efficacy is modeled as a construct with two dimensions: personal teaching efficacy (PTE) and outcome expectancy (OE). Findings suggest that the mathematics and science teaching efficacy (PTE) of pre-service teachers is a multi-class phenomena. The analyses revealed a four-class model of PTE at the beginning and end of the final year of teacher training. Results indicate that when pre-service teachers transition between classes, they tend to move from a lower efficacy class into a higher efficacy class. In addition, the findings suggest that time-varying variables (attitudes and beliefs) and time-invariant variables (previous coursework, previous experiences, and teacher perceptions) are statistically significant predictors of efficacy class membership. Further, analyses suggest that the measures used to assess outcome expectancy are not suitable for LCA and LTA procedures.

[Variables related to the emergence of differential patterns in work motivation].

PubMed

Arrieta, Carlos; Navarro, José; Vicente, Susana

2008-11-01

Several longitudinal studies have shown that motivation at work acts chaotically. In very few cases, it may be linear or random. However, the factors that might explain why these different patterns emerge have not been analysed to date. In this exploratory study, we interviewed 73 employees whose motivational patterns were previously known. The results revealed that chaotic patterns were associated with high levels of motivation, self-efficacy beliefs, and perceptions of instrumentality, and also with intrinsic personal goal orientation and a perception of high work control. Linear patterns were associated with extrinsic goals and a perception of work as difficult, and random patterns were linked to high flexibility at work.

The impact of competition on quality and prices in the English care homes market

PubMed Central

Forder, Julien; Allan, Stephen

2014-01-01

This study assesses the impact of competition on quality and price in the English care/nursing homes market. Considering the key institutional features, we use a theoretical model to assess the conditions under which further competition could increase or reduce quality. A dataset comprising the population of 10,000 care homes was used. We constructed distance/travel-time weighted competition measures. Instrumental variable estimations, used to account for the endogeneity of competition, showed quality and price were reduced by greater competition. Further analyses suggested that the negative quality effect worked through the effect on price – higher competition reduces revenue which pushes down quality. PMID:24487075

The impact of competition on quality and prices in the English care homes market.

PubMed

Forder, Julien; Allan, Stephen

2014-03-01

This study assesses the impact of competition on quality and price in the English care/nursing homes market. Considering the key institutional features, we use a theoretical model to assess the conditions under which further competition could increase or reduce quality. A dataset comprising the population of 10,000 care homes was used. We constructed distance/travel-time weighted competition measures. Instrumental variable estimations, used to account for the endogeneity of competition, showed quality and price were reduced by greater competition. Further analyses suggested that the negative quality effect worked through the effect on price - higher competition reduces revenue which pushes down quality. Copyright © 2013 Elsevier B.V. All rights reserved.

An Assessment of the Need for Standard Variable Names for Airborne Field Campaigns

NASA Astrophysics Data System (ADS)

Beach, A. L., III; Chen, G.; Northup, E. A.; Kusterer, J.; Quam, B. M.

2017-12-01

The NASA Earth Venture Program has led to a dramatic increase in airborne observations, requiring updated data management practices with clearly defined data standards and protocols for metadata. An airborne field campaign can involve multiple aircraft and a variety of instruments. It is quite common to have different instruments/techniques measure the same parameter on one or more aircraft platforms. This creates a need to allow instrument Principal Investigators (PIs) to name their variables in a way that would distinguish them across various data sets. A lack of standardization of variables names presents a challenge for data search tools in enabling discovery of similar data across airborne studies, aircraft platforms, and instruments. This was also identified by data users as one of the top issues in data use. One effective approach for mitigating this problem is to enforce variable name standardization, which can effectively map the unique PI variable names to fixed standard names. In order to ensure consistency amongst the standard names, it will be necessary to choose them from a controlled list. However, no such list currently exists despite a number of previous efforts to establish a sufficient list of atmospheric variable names. The Atmospheric Composition Variable Standard Name Working Group was established under the auspices of NASA's Earth Science Data Systems Working Group (ESDSWG) to solicit research community feedback to create a list of standard names that are acceptable to data providers and data users This presentation will discuss the challenges and recommendations of standard variable names in an effort to demonstrate how airborne metadata curation/management can be improved to streamline data ingest, improve interoperability, and discoverability to a broader user community.

[Stress level assessment of the nursing staff in the Intensive Care Unit of a university hospital].

PubMed

Carrillo-García, C; Ríos-Rísquez, M I; Martínez-Hurtado, R; Noguera-Villaescusa, P

2016-01-01

The objective was to determine the work stress level among nursing staff in the Intensive Care Unit of a university hospital and to analyse its relationship with the various sociodemographic and working variables of the studied sample. A study was designed using a quantitative, descriptive and cross-sectional approach. The target population of the study was the nursing staff selected by non-random sampling. The instrument used was the Job Content Questionnaire. Data analysis was performed using SPSS 20. The mean, ranges and standard deviation for each of the variables were calculated. A bivariate analysis was also performed on the social and occupational variables of the sample. The participation rate was 80.90% (N=89). The mean of the Social support dimension was 3.13±0.397, for the Psychological demands at work dimension it was 3.10±0.384, with a mean of 2.96±0.436 being obtained for the Control over the work dimension. In the analysis of sociodemographic and work variables of the sample, only the professional category was significant, with nurses recording higher values in perception of job demands and control over their work compared to nursing assistants. In conclusion, there is a moderate perception of work stress in the analysed group of professionals. Among the sources of stress in the workplace was the low control in decision-making by practitioners, as well as the need to continually learn new things. On the other hand, the support received from colleagues is valued positively by the sample. Copyright © 2016 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

Multi-year assimilation of IASI and MLS ozone retrievals: variability of tropospheric ozone over the tropics in response to ENSO

NASA Astrophysics Data System (ADS)

Peiro, Hélène; Emili, Emanuele; Cariolle, Daniel; Barret, Brice; Le Flochmoën, Eric

2018-05-01

The Infrared Atmospheric Sounder Instrument (IASI) allows global coverage with very high spatial resolution and its measurements are promising for long-term ozone monitoring. In this study, Microwave Limb Sounder (MLS) O3 profiles and IASI O3 partial columns (1013.25-345 hPa) are assimilated in a chemistry transport model to produce 6-hourly analyses of tropospheric ozone for 6 years (2008-2013). We have compared and evaluated the IASI-MLS analysis and the MLS analysis to assess the added value of IASI measurements. The global chemical transport model MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle) has been used with a linear ozone chemistry scheme and meteorological forcing fields from ERA-Interim (ECMWF global reanalysis) with a horizontal resolution of 2° × 2° and 60 vertical levels. The MLS and IASI O3 retrievals have been assimilated with a 4-D variational algorithm to constrain stratospheric and tropospheric ozone respectively. The ozone analyses are validated against ozone soundings and tropospheric column ozone (TCO) from the OMI-MLS residual method. In addition, an Ozone ENSO Index (OEI) is computed from the analysis to validate the TCO variability during the ENSO events. We show that the assimilation of IASI reproduces the variability of tropospheric ozone well during the period under study. The variability deduced from the IASI-MLS analysis and the OMI-MLS measurements are similar for the period of study. The IASI-MLS analysis can reproduce the extreme oscillation of tropospheric ozone caused by ENSO events over the tropical Pacific Ocean, although a correction is required to reduce a constant bias present in the IASI-MLS analysis.

Spatial and temporal analysis of drought variability at several time scales in Syria during 1961-2012

NASA Astrophysics Data System (ADS)

Mathbout, Shifa; Lopez-Bustins, Joan A.; Martin-Vide, Javier; Bech, Joan; Rodrigo, Fernando S.

2018-02-01

This paper analyses the observed spatiotemporal characteristics of drought phenomenon in Syria using the Standardised Precipitation Index (SPI) and the Standardised Precipitation Evapotranspiration Index (SPEI). Temporal variability of drought is calculated for various time scales (3, 6, 9, 12, and 24 months) for 20 weather stations over the 1961-2012 period. The spatial patterns of drought were identified by applying a Principal Component Analysis (PCA) to the SPI and SPEI values at different time scales. The results revealed three heterogeneous and spatially well-defined regions with different temporal evolution of droughts: 1) Northeastern (inland desert); 2) Southern (mountainous landscape); 3) Northwestern (Mediterranean coast). The evolutionary characteristics of drought during 1961-2012 were analysed including spatial and temporal variability of SPI and SPEI, the frequency distribution, and the drought duration. The results of the non-parametric Mann-Kendall test applied to the SPI and SPEI series indicate prevailing significant negative trends (drought) at all stations. Both drought indices have been correlated both on spatial and temporal scales and they are highly comparable, especially, over a 12 and 24 month accumulation period. We concluded that the temporal and spatial characteristics of the SPI and SPEI can be used for developing a drought intensity - areal extent - and frequency curve that assesses the variability of regional droughts in Syria. The analysis of both indices suggests that all three regions had a severe drought in the 1990s, which had never been observed before in the country. Furthermore, the 2007-2010 drought was the driest period in the instrumental record, happening just before the onset of the recent conflict in Syria.

Characterization of Noise Signatures of Involuntary Head Motion in the Autism Brain Imaging Data Exchange Repository

PubMed Central

Caballero, Carla; Mistry, Sejal; Vero, Joe; Torres, Elizabeth B

2018-01-01

The variability inherently present in biophysical data is partly contributed by disparate sampling resolutions across instrumentations. This poses a potential problem for statistical inference using pooled data in open access repositories. Such repositories combine data collected from multiple research sites using variable sampling resolutions. One example is the Autism Brain Imaging Data Exchange repository containing thousands of imaging and demographic records from participants in the spectrum of autism and age-matched neurotypical controls. Further, statistical analyses of groups from different diagnoses and demographics may be challenging, owing to the disparate number of participants across different clinical subgroups. In this paper, we examine the noise signatures of head motion data extracted from resting state fMRI data harnessed under different sampling resolutions. We characterize the quality of the noise in the variability of the raw linear and angular speeds for different clinical phenotypes in relation to age-matched controls. Further, we use bootstrapping methods to ensure compatible group sizes for statistical comparison and report the ranges of physical involuntary head excursions of these groups. We conclude that different sampling rates do affect the quality of noise in the variability of head motion data and, consequently, the type of random process appropriate to characterize the time series data. Further, given a qualitative range of noise, from pink to brown noise, it is possible to characterize different clinical subtypes and distinguish them in relation to ranges of neurotypical controls. These results may be of relevance to the pre-processing stages of the pipeline of analyses of resting state fMRI data, whereby head motion enters the criteria to clean imaging data from motion artifacts. PMID:29556179

[Instruments for evaluating oral health knowledge, attitudes and practice for parents /caregivers of small children].

PubMed

Martignon, Stefania; Bautista-Mendoza, Gloria; González-Carrera, María; Lafaurie-Villamil, Gloria; Morales, Veicy; Santamaría, Ruth

2008-01-01

Designing three instruments for evaluating oral health knowledge, attitudes and practice in parents/caregivers of low social-economic status 0-5 year-olds. Evaluating the instruments' reliability in terms of internal consistency and analysing items. Three instruments were constructed for evaluating low social-economic status 0-5 year-olds' parents/caregivers' oral health knowledge, attitudes and practice in the municipality of Usaquén , Bogotá , Colombia . 47 parents/caregivers were given a test establishing the instrument's reliability in terms of internal consistency and the adults' level of knowledge, attitudes and practice. A sub-sample was qualitatively analysed (content verification and understanding). Reliability was evaluated using Cronbach's alpha coefficient. Items were analysed for improving constructing and understanding the questions, taking four criteria into account: corrected homogeneity index (CHI), response trend, correlation between items and qualitative analysis. Cronbach's alpha coefficient for knowledge, attitudes and practice was 0,82, 0,80 and 0,62, respectively. Participants' level of knowledge, attitudes and practice was acceptable (60 %, 55 % and 91 %, respectively). This study found two out of the three evaluated instruments to be reliable (knowledge and attitudes); all three of them were then redesigned. The resulting instruments represent a valuable tool which can be used in future studies for describing and evaluating preventative programmes.

Use of allele scores as instrumental variables for Mendelian randomization

PubMed Central

Burgess, Stephen; Thompson, Simon G

2013-01-01

Background An allele score is a single variable summarizing multiple genetic variants associated with a risk factor. It is calculated as the total number of risk factor-increasing alleles for an individual (unweighted score), or the sum of weights for each allele corresponding to estimated genetic effect sizes (weighted score). An allele score can be used in a Mendelian randomization analysis to estimate the causal effect of the risk factor on an outcome. Methods Data were simulated to investigate the use of allele scores in Mendelian randomization where conventional instrumental variable techniques using multiple genetic variants demonstrate ‘weak instrument’ bias. The robustness of estimates using the allele score to misspecification (for example non-linearity, effect modification) and to violations of the instrumental variable assumptions was assessed. Results Causal estimates using a correctly specified allele score were unbiased with appropriate coverage levels. The estimates were generally robust to misspecification of the allele score, but not to instrumental variable violations, even if the majority of variants in the allele score were valid instruments. Using a weighted rather than an unweighted allele score increased power, but the increase was small when genetic variants had similar effect sizes. Naive use of the data under analysis to choose which variants to include in an allele score, or for deriving weights, resulted in substantial biases. Conclusions Allele scores enable valid causal estimates with large numbers of genetic variants. The stringency of criteria for genetic variants in Mendelian randomization should be maintained for all variants in an allele score. PMID:24062299

Do Two or More Multicomponent Instruments Measure the Same Construct? Testing Construct Congruence Using Latent Variable Modeling

ERIC Educational Resources Information Center

Raykov, Tenko; Marcoulides, George A.; Tong, Bing

2016-01-01

A latent variable modeling procedure is discussed that can be used to test if two or more homogeneous multicomponent instruments with distinct components are measuring the same underlying construct. The method is widely applicable in scale construction and development research and can also be of special interest in construct validation studies.…

Cross-cultural adaptation, validity, and reliability of the Parenting Styles and Dimensions Questionnaire - Short Version (PSDQ) for use in Brazil.

PubMed

Oliveira, Thaís D; Costa, Danielle de S; Albuquerque, Maicon R; Malloy-Diniz, Leandro F; Miranda, Débora M; de Paula, Jonas J

2018-06-11

The Parenting Styles and Dimensions Questionnaire (PSDQ) is used worldwide to assess three styles (authoritative, authoritarian, and permissive) and seven dimensions of parenting. In this study, we adapted the short version of the PSDQ for use in Brazil and investigated its validity and reliability. Participants were 451 mothers of children aged 3 to 18 years, though sample size varied with analyses. The translation and adaptation of the PSDQ followed a rigorous methodological approach. Then, we investigated the content, criterion, and construct validity of the adapted instrument. The scale content validity index (S-CVI) was considered adequate (0.97). There was evidence of internal validity, with the PSDQ dimensions showing strong correlations with their higher-order parenting styles. Confirmatory factor analysis endorsed the three-factor, second-order solution (i.e., three styles consisting of seven dimensions). The PSDQ showed convergent validity with the validated Brazilian version of the Parenting Styles Inventory (Inventário de Estilos Parentais - IEP), as well as external validity, as it was associated with several instruments measuring sociodemographic and behavioral/emotional-problem variables. The PSDQ is an effective and reliable psychometric instrument to assess childrearing strategies according to Baumrind's model of parenting styles.

Assessing the heterogeneity of aggressive behavior traits: exploratory and confirmatory analyses of the reactive and instrumental aggression Personality Assessment Inventory (PAI) scales.

PubMed

Antonius, Daniel; Sinclair, Samuel Justin; Shiva, Andrew A; Messinger, Julie W; Maile, Jordan; Siefert, Caleb J; Belfi, Brian; Malaspina, Dolores; Blais, Mark A

2013-01-01

The heterogeneity of violent behavior is often overlooked in risk assessment despite its importance in the management and treatment of psychiatric and forensic patients. In this study, items from the Personality Assessment Inventory (PAI) were first evaluated and rated by experts in terms of how well they assessed personality features associated with reactive and instrumental aggression. Exploratory principal component analyses (PCA) were then conducted on select items using a sample of psychiatric and forensic inpatients (n = 479) to examine the latent structure and construct validity of these reactive and instrumental aggression factors. Finally, a confirmatory factor analysis (CFA) was conducted on a separate sample of psychiatric inpatients (n = 503) to evaluate whether these factors yielded acceptable model fit. Overall, the exploratory and confirmatory analyses supported the existence of two latent PAI factor structures, which delineate personality traits related to reactive and instrumental aggression.

Consumer acceptance of fresh blueberries in bio-based packages.

PubMed

Almenar, Eva; Samsudin, Hayati; Auras, Rafael; Harte, Janice

2010-05-01

Instrumental analyses have shown that non-vented bio-based containers made from poly(lactic acid) (PLA) have the capability to enhance blueberry shelf life as compared with commercial vented petroleum-based clamshell containers. However, consumer preference has not been explored so far. In this study, two sensory evaluations, triangle and paired preference tests, were performed after storing fruit in both containers at 3 and 10 degrees C for 7 and 14 days. In addition, physicochemical analyses were performed after each tasting in order to correlate instrumental findings with consumer preference. The results of the triangle test showed the capability of the consumer to differentiate (P < or = 0.001) between blueberries from different packages at both storage temperatures. A consumer preference for flavour, texture, external appearance and overall quality (P < or = 0.001) of blueberries packaged in PLA containers was observed in the paired comparison test. The instrumental analyses showed that blueberries in the PLA packages exhibited a weight loss below the limit for marketable life, a stable soluble solid content and titratable acidity and no fungal growth during storage. Consumers distinguished between blueberries from different packages and preferred those packaged in the PLA containers. The instrumental analyses showed that the usable life of the berries was extended in the PLA containers. A correlation between consumer preference and instrumental evaluations was found.

Instruments as Empirical Evidence for the Analysis of Higher Education Policies

ERIC Educational Resources Information Center

Reale, Emanuela; Seeber, Marco

2013-01-01

This paper focuses on policy implementation in Higher Education (HE) analysed through the evolution and transformation of policy instruments related to government funding and evaluation. We investigate how steering and governance tools have been put into action, in order to analyse how original policy rationales and justifications have evolved and…

Measurement of factors that negatively influence the outcome of quitting smoking among patients with COPD: psychometric analyses of the Try To Quit Smoking instrument.

PubMed

Lundh, Lena; Alinaghizadeh, Hassan; Törnkvist, Lena; Gilljam, Hans; Galanti, Maria Rosaria

2014-12-01

To test internal consistency and factor structure of a brief instrument called Trying to Quit smoking. The most effective treatment for patients with chronic obstructive pulmonary disease is to quit smoking. Constant thoughts about quitting and repeated quit attempts can generate destructive feelings and make it more difficult to quit. Development and psychometric testing of the Trying to Quit smoking scale. The Trying to Quit smoking, an instrument designed to assess pressure-filled states of mind and corresponding pressure-relief strategies, was tested among 63 Swedish patients with chronic obstructive pulmonary disease. Among these, the psychometric properties of the instrument were analysed by Exploratory Factor Analyses. Fourteen items were included in the factor analyses, loading on three factors labelled: (1) development of pressure-filled mental states; (2) use of destructive pressure-relief strategies; and (3) ambivalent thoughts when trying to quit smoking. These three factors accounted for more than 80% of the variance, performed well on the Kaiser-Meyer-Olkin (KMO) test and had high internal consistency.

Ground-based assessment of the bias and long-term stability of fourteen limb and occultation ozone profile data records.

PubMed

Hubert, D; Lambert, J-C; Verhoelst, T; Granville, J; Keppens, A; Baray, J-L; Cortesi, U; Degenstein, D A; Froidevaux, L; Godin-Beekmann, S; Hoppel, K W; Kyrölä, E; Leblanc, T; Lichtenberg, G; McElroy, C T; Murtagh, D; Nakane, H; Querel, R; Russell, J M; Salvador, J; Smit, H G J; Stebel, K; Steinbrecht, W; Strawbridge, K B; Stübi, R; Swart, D P J; Taha, G; Thompson, A M; Urban, J; van Gijsel, J A E; von der Gathen, P; Walker, K A; Wolfram, E; Zawodny, J M

2016-01-01

The ozone profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of these data sets, especially of their long-term stability and their mutual consistency. To this end, we made a systematic assessment of fourteen limb and occultation sounders that, together, provide more than three decades of global ozone profile measurements. In particular, we considered the latest operational Level-2 records by SAGE II, SAGE III, HALOE, UARS MLS, Aura MLS, POAM II, POAM III, OSIRIS, SMR, GOMOS, MIPAS, SCIAMACHY, ACE-FTS and MAESTRO. Central to our work is a consistent and robust analysis of the comparisons against the ground-based ozonesonde and stratospheric ozone lidar networks. It allowed us to investigate, from the troposphere up to the stratopause, the following main aspects of satellite data quality: long-term stability, overall bias, and short-term variability, together with their dependence on geophysical parameters and profile representation. In addition, it permitted us to quantify the overall consistency between the ozone profilers. Generally, we found that between 20-40 km the satellite ozone measurement biases are smaller than ±5 %, the short-term variabilities are less than 5-12% and the drifts are at most ±5% decade -1 (or even ±3 % decade -1 for a few records). The agreement with ground-based data degrades somewhat towards the stratopause and especially towards the tropopause where natural variability and low ozone abundances impede a more precise analysis. In part of the stratosphere a few records deviate from the preceding general conclusions; we identified biases of 10% and more (POAM II and SCIAMACHY), markedly higher single-profile variability (SMR and SCIAMACHY), and significant long-term drifts (SCIAMACHY, OSIRIS, HALOE, and possibly GOMOS and SMR as well). Furthermore, we reflected on the repercussions of our findings for the construction, analysis and interpretation of merged data records. Most notably, the discrepancies between several recent ozone profile trend assessments can be mostly explained by instrumental drift. This clearly demonstrates the need for systematic comprehensive multi-instrument comparison analyses.

Ground-Based Assessment of the Bias and Long-Term Stability of Fourteen Limb and Occultation Ozone Profile Data Records

NASA Technical Reports Server (NTRS)

Hubert, D.; Lambert, J.-C.; Verhoelst, T.; Granville, J.; Keppens, A.; Baray, J.-L.; Cortesi, U.; Degenstein, D. A.; Froidevaux, L.; Godin-Beekmann, S.;

Ground-based assessment of the bias and long-term stability of fourteen limb and occultation ozone profile data records

PubMed Central

Hubert, D.; Lambert, J.-C.; Verhoelst, T.; Granville, J.; Keppens, A.; Baray, J.-L.; Cortesi, U.; Degenstein, D. A.; Froidevaux, L.; Godin-Beekmann, S.; Hoppel, K. W.; Kyrölä, E.; Leblanc, T.; Lichtenberg, G.; McElroy, C. T.; Murtagh, D.; Nakane, H.; Querel, R.; Russell, J. M.; Salvador, J.; Smit, H. G. J.; Stebel, K.; Steinbrecht, W.; Strawbridge, K. B.; Stübi, R.; Swart, D. P. J.; Taha, G.; Thompson, A. M.; Urban, J.; van Gijsel, J. A. E.; von der Gathen, P.; Walker, K. A.; Wolfram, E.; Zawodny, J. M.

2018-01-01

The ozone profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of these data sets, especially of their long-term stability and their mutual consistency. To this end, we made a systematic assessment of fourteen limb and occultation sounders that, together, provide more than three decades of global ozone profile measurements. In particular, we considered the latest operational Level-2 records by SAGE II, SAGE III, HALOE, UARS MLS, Aura MLS, POAM II, POAM III, OSIRIS, SMR, GOMOS, MIPAS, SCIAMACHY, ACE-FTS and MAESTRO. Central to our work is a consistent and robust analysis of the comparisons against the ground-based ozonesonde and stratospheric ozone lidar networks. It allowed us to investigate, from the troposphere up to the stratopause, the following main aspects of satellite data quality: long-term stability, overall bias, and short-term variability, together with their dependence on geophysical parameters and profile representation. In addition, it permitted us to quantify the overall consistency between the ozone profilers. Generally, we found that between 20–40 km the satellite ozone measurement biases are smaller than ±5 %, the short-term variabilities are less than 5–12% and the drifts are at most ±5% decade−1 (or even ±3 % decade−1 for a few records). The agreement with ground-based data degrades somewhat towards the stratopause and especially towards the tropopause where natural variability and low ozone abundances impede a more precise analysis. In part of the stratosphere a few records deviate from the preceding general conclusions; we identified biases of 10% and more (POAM II and SCIAMACHY), markedly higher single-profile variability (SMR and SCIAMACHY), and significant long-term drifts (SCIAMACHY, OSIRIS, HALOE, and possibly GOMOS and SMR as well). Furthermore, we reflected on the repercussions of our findings for the construction, analysis and interpretation of merged data records. Most notably, the discrepancies between several recent ozone profile trend assessments can be mostly explained by instrumental drift. This clearly demonstrates the need for systematic comprehensive multi-instrument comparison analyses. PMID:29743958

Chemical analyses in the World Coal Quality Inventory

USGS Publications Warehouse

Tewalt, Susan J.; Belkin, Harvey E.; SanFilipo, John R.; Merrill, Matthew D.; Palmer, Curtis A.; Warwick, Peter D.; Karlsen, Alexander W.; Finkelman, Robert B.; Park, Andy J.

2010-01-01

The main objective of the World Coal Quality Inventory (WoCQI) was to collect and analyze a global set of samples of mined coal during a time period from about 1995 to 2006 (Finkelman and Lovern, 2001). Coal samples were collected by foreign collaborators and submitted to country specialists in the U.S. Geological Survey (USGS) Energy Program. However, samples from certain countries, such as Afghanistan, India, and Kyrgyzstan, were collected collaboratively in the field with USGS personnel. Samples were subsequently analyzed at two laboratories: the USGS Inorganic Geochemistry Laboratory located in Denver, CO and a commercial laboratory (Geochemical Testing, Inc.) located in Somerset, PA. Thus the dataset, which is in Excel (2003) format and includes 1,580 samples from 57 countries, does not have the inter-laboratory variability that is present in many compilations. Major-, minor-, and trace-element analyses from the USGS laboratory, calculated to a consistent analytical basis (dry, whole-coal) and presented with available sample identification information, are sorted alphabetically by country name. About 70 percent of the samples also have data from the commercial laboratory, which are presented on an as-received analytical basis. The USGS initiated a laboratory review of quality assurance in 2008, covering quality control and methodology used in inorganic chemical analyses of coal, coal power plant ash, water, and sediment samples. This quality control review found that data generated by the USGS Inorganic Geochemistry Laboratory from 1996 through 2006 were characterized by quality practices that did not meet USGS requirements commonly in use at the time. The most serious shortcomings were (1) the adjustment of raw sample data to standards when the instrument values for those standards exceeded acceptable limits or (2) the insufficient use of multiple standards to provide adequate quality assurance. In general, adjustment of raw data to account for instrument 'drift' is an acceptable practice within strictly defined limits. During the denoted period, USGS required that the maximum adjustment of instrument values, guided by calibration standards, was not allowed to exceed 10 percent. However, in some cases, the Inorganic Geochemistry Laboratory released data that were adjusted by more than 10 percent and (or) were not constrained by an adequate number of control standards. Original instrument values no longer exist for about 80 percent of the analyses during this period; therefore, the acceptability of drift corrections for most of the samples analyzed cannot be determined. For these reasons, the WoCQI data from the USGS Inorganic Geochemistry Laboratory should be used with care. For more information, individuals may contact laboratory management at EnergyLabs@usgs.gov with specific questions about particular datasets or analytical attributes. Standard USGS sampling methods were provided and recommended to collaborators, but the analyzed samples may or may not be representative of their locale; for some samples, only limited information is available concerning sample provenance. Single samples cannot represent spatial or temporal variability within a coal area. Geochemical datasets of U.S. coals can be found in the COALQUAL database (Bragg and others, 1997) and the National Coal Quality Inventory (Hatch and others, 2006), as only non-U.S. sample data are presented in the WoCQI. Although the WoCQI does not contain worldwide coverage of coal deposits, it is truly a unique and valuable compilation. The information in the WoCQI should prove useful for identifying possible areas for future global coal research.

Robust best linear estimator for Cox regression with instrumental variables in whole cohort and surrogates with additive measurement error in calibration sample.

PubMed

Wang, Ching-Yun; Song, Xiao

2016-11-01

Biomedical researchers are often interested in estimating the effect of an environmental exposure in relation to a chronic disease endpoint. However, the exposure variable of interest may be measured with errors. In a subset of the whole cohort, a surrogate variable is available for the true unobserved exposure variable. The surrogate variable satisfies an additive measurement error model, but it may not have repeated measurements. The subset in which the surrogate variables are available is called a calibration sample. In addition to the surrogate variables that are available among the subjects in the calibration sample, we consider the situation when there is an instrumental variable available for all study subjects. An instrumental variable is correlated with the unobserved true exposure variable, and hence can be useful in the estimation of the regression coefficients. In this paper, we propose a nonparametric method for Cox regression using the observed data from the whole cohort. The nonparametric estimator is the best linear combination of a nonparametric correction estimator from the calibration sample and the difference of the naive estimators from the calibration sample and the whole cohort. The asymptotic distribution is derived, and the finite sample performance of the proposed estimator is examined via intensive simulation studies. The methods are applied to the Nutritional Biomarkers Study of the Women's Health Initiative. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of Music Student Efficacy as Influenced by Age, Experience, Gender, Ethnicity, and Type of Instrument Played in South Carolina

ERIC Educational Resources Information Center

White, Norman

2010-01-01

The purpose of this research study was to quantitatively examine South Carolina high school instrumental music students' self-efficacy as measured by the Generalized Self-Efficacy (GSE) instrument (Schwarzer & Jerusalem, 1993). The independent variables of age, experience, gender, ethnicity, and type of instrument played) were correlated with…

Teaching Strategies and Gender in Higher Education Instrumental Studios

ERIC Educational Resources Information Center

Zhukov, Katie

2012-01-01

This study investigates instrumental music teaching strategies in higher education settings, in order to identify those employed and their frequency and context of use. An instrument- and gender-balanced sample of 24 lessons from five institutions was analysed using a researcher-designed observational instrument. The results reveal the…

Parameter de-correlation and model-identification in hybrid-style terrestrial laser scanner self-calibration

NASA Astrophysics Data System (ADS)

Lichti, Derek D.; Chow, Jacky; Lahamy, Hervé

One of the important systematic error parameters identified in terrestrial laser scanners is the collimation axis error, which models the non-orthogonality between two instrumental axes. The quality of this parameter determined by self-calibration, as measured by its estimated precision and its correlation with the tertiary rotation angle κ of the scanner exterior orientation, is strongly dependent on instrument architecture. While the quality is generally very high for panoramic-type scanners, it is comparably poor for hybrid-style instruments. Two methods for improving the quality of the collimation axis error in hybrid instrument self-calibration are proposed herein: (1) the inclusion of independent observations of the tertiary rotation angle κ; and (2) the use of a new collimation axis error model. Five real datasets were captured with two different hybrid-style scanners to test each method's efficacy. While the first method achieves the desired outcome of complete decoupling of the collimation axis error from κ, it is shown that the high correlation is simply transferred to other model variables. The second method achieves partial parameter de-correlation to acceptable levels. Importantly, it does so without any adverse, secondary correlations and is therefore the method recommended for future use. Finally, systematic error model identification has been greatly aided in previous studies by graphical analyses of self-calibration residuals. This paper presents results showing the architecture dependence of this technique, revealing its limitations for hybrid scanners.

Pathological video-gaming among Singaporean youth.

PubMed

Choo, Hyekyung; Gentile, Douglas A; Sim, Timothy; Li, Dongdong; Khoo, Angeline; Liau, Albert K

2010-11-01

Increase in internet use and video-gaming contributes to public concern on pathological or obsessive play of video games among children and adolescents worldwide. Nevertheless, little is known about the prevalence of pathological symptoms in video-gaming among Singaporean youth and the psychometric properties of instruments measuring pathological symptoms in video-gaming. A total of 2998 children and adolescents from 6 primary and 6 secondary schools in Singapore responded to a comprehensive survey questionnaire on sociodemographic characteristics, video-gaming habits, school performance, somatic symptoms, various psychological traits, social functioning and pathological symptoms of video-gaming. After weighting, the survey data were analysed to determine the prevalence of pathological video-gaming among Singaporean youth and gender differences in the prevalence. The construct validity of instrument used to measure pathological symptoms of video-gaming was tested. Of all the study participants, 8.7% were classified as pathological players with more boys reporting more pathological symptoms than girls. All variables, including impulse control problem, social competence, hostility, academic performance, and damages to social functioning, tested for construct validity, were significantly associated with pathological status, providing good evidence for the construct validity of the instrument used. The prevalence rate of pathological video-gaming among Singaporean youth is comparable with that from other countries studied thus far, and gender differences are also consistent with the findings of prior research. The positive evidence of construct validity supports the potential use of the instrument for future research and clinical screening on Singapore children and adolescents' pathological video-gaming.

Mapping Variables.

ERIC Educational Resources Information Center

Stone, Mark H.; Wright, Benjamin D.; Stenner, A. Jackson

1999-01-01

Describes mapping variables, the principal technique for planning and constructing a test or rating instrument. A variable map is also useful for interpreting results. Provides several maps to show the importance and value of mapping a variable by person and item data. (Author/SLD)

Perceived social support following percutaneous coronary intervention is a crucial factor in patients with coronary heart disease.

PubMed

Kähkönen, Outi; Kankkunen, Päivi; Miettinen, Heikki; Lamidi, Marja-Leena; Saaranen, Terhi

2017-05-01

To describe perceived social support among patients with coronary heart disease following percutaneous coronary intervention. A low level of social support is considered a risk factor for coronary heart disease in healthy individuals and reduces the likelihood that people diagnosed with coronary heart disease will have a good prognosis. A descriptive cross-sectional study. A survey of 416 patients was conducted in 2013. A self-report instrument, Social Support of People with Coronary Heart Disease, was used. The instrument comprises three dimensions of social support: informational, emotional, functional supports and 16 background variables. Data were analysed using descriptive statistics, factor analysis, mean sum variables and multivariate logistic regression. Perceived informational support was primarily high, but respondents' risk factors were not at the target level. The weakest items of informational support were advice on physical activity, continuum of care and rehabilitation. Regarding the items of emotional support, support from other cardiac patients was the weakest. The weakest item of functional support was respondents' sense of the healthcare professionals' care of patients coping with their disease. Background variables associated with perceived social support were gender, marital status, level of formal education, profession, physical activity, duration of coronary heart disease and previous myocardial infarction. Healthcare professionals should pay extra attention to women, single patients, physically inactive patients, those demonstrating a lower level of education, those with a longer duration of CHD, and respondents without previous acute myocardial infarction. Continuum of care and counselling are important to ensure especially among them. This study provides evidence that healthcare professionals should be more aware of the individual needs for social support among patients with coronary heart disease after percutaneous coronary intervention. © 2016 John Wiley & Sons Ltd.

Adapting the academic motivation scale for use in pre-tertiary mathematics classrooms

NASA Astrophysics Data System (ADS)

Lim, Siew Yee; Chapman, Elaine

2015-09-01

The Academic Motivation Scale ( ams) is a comprehensive and widely used instrument for assessing motivation based on the self-determination theory. Currently, no such comprehensive instrument exists to assess the different domains of motivation (stipulated by the self-determination theory) in mathematics education at the pre-tertiary level (grades 11 and 12) in Asia. This study adapted the ams for this use and assessed the properties of the adapted instrument with 1610 students from Singapore. Exploratory and confirmatory factor analyses indicated a five-factor structure for the modified instrument (the three original ams intrinsic subscales collapsed into a single factor). Additionally, the modified instrument exhibited good internal consistency (mean α = .88), and satisfactory test-retest reliability over a 1-month interval (mean r xx = .73). The validity of the modified ams was further demonstrated through correlational analyses among scores on its subscales, and with scores on other instruments measuring mathematics attitudes, anxiety and achievement.

A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for In-Situ Mars Surface Sample Analysis

NASA Technical Reports Server (NTRS)

Edmunson, J.; Gaskin, J. A.; Jerman, G. A.; Harvey, R. P.; Doloboff, I. J.; Neidholdt, E. L.

2016-01-01

The Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Sciences (ROSES), will build upon previous miniaturized SEM designs and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. This project is a collaboration between NASA Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), electron gun and optics manufacturer Applied Physics Technologies, and small vacuum system manufacturer Creare. Dr. Ralph Harvery and environmental SEM (ESEM) inventor Dr. Gerry Danilatos serve as advisors to the team. Variable pressure SEMs allow for fine (nm-scale) resolution imaging and micron-scale chemical study of materials without sample preparation (e.g., carbon or gold coating). Charging of a sample is reduced or eliminated by the gas surrounding the sample. It is this property of ESEMs that make them ideal for locations where sample preparation is not yet feasible, such as the surface of Mars. In addition, the lack of sample preparation needed here will simplify the sample acquisition process and allow caching of the samples for future complementary payload use.

Predicting College Women's Career Plans: Instrumentality, Work, and Family

ERIC Educational Resources Information Center

Savela, Alexandra E.; O'Brien, Karen M.

2016-01-01

This study examined how college women's instrumentality and expectations about combining work and family predicted early career development variables. Specifically, 177 undergraduate women completed measures of instrumentality (i.e., traits such as ambition, assertiveness, and risk taking), willingness to compromise career for family, anticipated…

A critical appraisal of instruments to measure outcomes of interprofessional education.

PubMed

Oates, Matthew; Davidson, Megan

2015-04-01

Interprofessional education (IPE) is believed to prepare health professional graduates for successful collaborative practice. A range of instruments have been developed to measure the outcomes of IPE. An understanding of the psychometric properties of these instruments is important if they are to be used to measure the effectiveness of IPE. This review set out to identify instruments available to measure outcomes of IPE and collaborative practice in pre-qualification health professional students and to critically appraise the psychometric properties of validity, responsiveness and reliability against contemporary standards for instrument design. Instruments were selected from a pool of extant instruments and subjected to critical appraisal to determine whether they satisfied inclusion criteria. The qualitative and psychometric attributes of the included instruments were appraised using a checklist developed for this review. Nine instruments were critically appraised, including the widely adopted Readiness for Interprofessional Learning Scale (RIPLS) and the Interdisciplinary Education Perception Scale (IEPS). Validity evidence for instruments was predominantly based on test content and internal structure. Ceiling effects and lack of scale width contribute to the inability of some instruments to detect change in variables of interest. Limited reliability data were reported for two instruments. Scale development and scoring protocols were generally reported by instrument developers, but the inconsistent application of scoring protocols for some instruments was apparent. A number of instruments have been developed to measure outcomes of IPE in pre-qualification health professional students. Based on reported validity evidence and reliability data, the psychometric integrity of these instruments is limited. The theoretical test construction paradigm on which instruments have been developed may be contributing to the failure of some instruments to detect change in variables of interest following an IPE intervention. These limitations should be considered in any future research on instrument design. © 2015 John Wiley & Sons Ltd.

The effects of types of social networks, perceived social support, and loneliness on the health of older people: accounting for the social context.

PubMed

Stephens, Christine; Alpass, Fiona; Towers, Andy; Stevenson, Brendan

2011-09-01

To use an ecological model of ageing (Berkman, Glass, Brissette, & Seeman, 2000) which includes upstream social context factors and downstream social support factors to examine the effects of social networks on health. Postal survey responses from a representative population sample of New Zealanders aged 55 to 70 years (N = 6,662). Correlations and multiple regression analyses provided support for a model in which social context contributes to social network type, which affects perceived social support and loneliness, and consequent mental and physical health. Ethnicity was related to social networks and health but this was largely accounted for by other contextual variables measuring socioeconomic status. Gender and age were also significant variables in the model. Social network type is a useful way to assess social integration within this model of cascading effects. More detailed information could be gained through the development of our network assessment instruments for older people.

Families at financial risk due to high ratio of out-of-pocket health care expenditures to total income.

PubMed

Bennett, Kevin J; Dismuke, Clara E

2010-05-01

High out-of-pocket expenditures for health care can put individuals and families at financial risk. Several groups, including racial/ethnic minority groups, the uninsured, rural residents, and those in poorer health are at risk for this increased burden. The analysis utilized 2004-2005 MEPS data. The dependent variables were the out-of-pocket health care spending to total income ratios for total spending, office-based visits, and prescription drugs. Multivariate analyses with instrumental variables controlled for respondent characteristics. Gender, age, rurality, insurance coverage, health status, and health care utilization were all associated with higher out-of-pocket to income ratios. Certain groups, such as women, the elderly, those in poor health, and rural residents, are at a greater financial risk due to their higher out-of-pocket to total income spending ratios. Policymakers must be aware of these increased risks in order to provide adequate resources and targeted interventions to alleviate some of this burden.

Biospectral analysis of the bladder channel point in chronic low back pain patients

NASA Astrophysics Data System (ADS)

Vidal, Alberto Espinosa; Nava, Juan José Godina; Segura, Miguel Ángel Rodriguez; Bastida, Albino Villegas

2012-10-01

Chronic pain is the main cause of disability in the productive age people and is a public health problem that affects both the patient and society. On the other hand, there isn't any instrument to measure it; this is only estimated using subjective variables. The healthy cells generate a known membrane potential which is part of a network of biologically closed electric circuits still unstudied. It is proposed a biospectral analysis of a bladder channel point as a diagnosis method for chronic low back pain patients. Materials and methods: We employed a study group with chronic low back pain patients and a control group without low back pain patients. The visual analog scale (VAS) to determine the level of pain was applied. Bioelectric variables were measured for 10 seconds and the respective biostatistical analyses were made. Results: Biospectral analysis on frequency domain shows a depression in the 60-300 Hz frequency range proportional to the chronicity of low back pain compared against healthy patients.

AMBULATORY BLOOD PRESSURE MONITORING: THE NEED OF 7-DAY RECORD

PubMed Central

HALBERG, F.; KATINAS, G.; CORNÉLISSEN, G.; SCHWARTZKOPFF, O.; FIŠER, B.; SIEGELOVÁ, J.; DUŠEK, J.; JANČÍK, J.

2008-01-01

The need for systematic around-the-clock self-measurements of blood pressure (BP) and heart rate (HR), or preferably for automatic monitoring as the need arises and can be met by inexpensive tools, is illustrated in two case reports. Miniaturized unobtrusive, as yet unavailable instrumentation for the automatic measurement of BP and HR should be a high priority for both government and industry. Automatic ambulatorily functioning monitors already represent great progress, enabling us to introduce the concept of eventually continuous or, as yet, intermittent home ABPM. On BP and HR records, gliding spectra aligned with global spectra visualize the changing dynamics involved in health and disease, and can be part of an eventually automated system of therapy adjusted to the ever-present variability of BP. In the interim, with tools already available, chronomics on self- or automatic measurements can be considered, with analyses provided by the Halberg Chronobiology Center, as an alternative to “flying blind”, as an editor put it. Chronomics assessing variability has to be considered. PMID:19018289

Emergency Medical Services Intervals and Survival in Trauma: Assessment of the “Golden Hour” in a North American Prospective Cohort

PubMed Central

Newgard, Craig D.; Schmicker, Robert H.; Hedges, Jerris R.; Trickett, John P.; Davis, Daniel P.; Bulger, Eileen M.; Aufderheide, Tom P.; Minei, Joseph P.; Hata, J. Steven; Gubler, K. Dean; Brown, Todd B.; Yelle, Jean-Denis; Bardarson, Berit; Nichol, Graham

2010-01-01

Study objective The first hour after the onset of out-of-hospital traumatic injury is referred to as the “golden hour,” yet the relationship between time and outcome remains unclear. We evaluate the association between emergency medical services (EMS) intervals and mortality among trauma patients with field-based physiologic abnormality. Methods This was a secondary analysis of an out-of-hospital, prospective cohort registry of adult (aged ≥15 years) trauma patients transported by 146 EMS agencies to 51 Level I and II trauma hospitals in 10 sites across North America from December 1, 2005, through March 31, 2007. Inclusion criteria were systolic blood pressure less than or equal to 90 mm Hg, respiratory rate less than 10 or greater than 29 breaths/min, Glasgow Coma Scale score less than or equal to 12, or advanced airway intervention. The outcome was inhospital mortality. We evaluated EMS intervals (activation, response, on-scene, transport, and total time) with logistic regression and 2-step instrumental variable models, adjusted for field-based confounders. Results There were 3,656 trauma patients available for analysis, of whom 806 (22.0%) died. In multivariable analyses, there was no significant association between time and mortality for any EMS interval: activation (odds ratio [OR] 1.00; 95% confidence interval [CI] 0.95 to 1.05), response (OR 1.00; 95% CI 9.97 to 1.04), on-scene (OR 1.00; 95% CI 0.99 to 1.01), transport (OR 1.00; 95% CI 0.98 to 1.01), or total EMS time (OR 1.00; 95% CI 0.99 to 1.01). Subgroup and instrumental variable analyses did not qualitatively change these findings. Conclusion In this North American sample, there was no association between EMS intervals and mortality among injured patients with physiologic abnormality in the field. PMID:19783323

Spatial and Temporal Variability of Trace Gas Columns Derived from WRF/Chem Regional Model Output: Planning for Geostationary Observations of Atmospheric Composition

NASA Technical Reports Server (NTRS)

Follette-Cook, M. B.; Pickering, K.; Crawford, J.; Duncan, B.; Loughner, C.; Diskin, G.; Fried, A.; Weinheimer, A.

2015-01-01

We quantify both the spatial and temporal variability of column integrated O3, NO2, CO, SO2, and HCHO over the Baltimore / Washington, DC area using output from the Weather Research and Forecasting model with on-line chemistry (WRF/Chem) for the entire month of July 2011, coinciding with the first deployment of the NASA Earth Venture program mission Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ). Using structure function analyses, we find that the model reproduces the spatial variability observed during the campaign reasonably well, especially for O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument will be the first NASA mission to make atmospheric composition observations from geostationary orbit and partially fulfills the goals of the Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission. We relate the simulated variability to the precision requirements defined by the science traceability matrices of these space-borne missions. Results for O3 from 0- 2 km altitude indicate that the TEMPO instrument would be able to observe O3 air quality events over the Mid-Atlantic area, even on days when the violations of the air quality standard are not widespread. The results further indicated that horizontal gradients in CO from 0-2 km would be observable over moderate distances (= 20 km). The spatial and temporal results for tropospheric column NO2 indicate that TEMPO would be able to observe not only the large urban plumes at times of peak production, but also the weaker gradients between rush hours. This suggests that the proposed spatial and temporal resolutions for these satellites as well as their prospective precision requirements are sufficient to answer the science questions they are tasked to address.

Seasonally-resolved trace element concentrations in stalagmites from a shallow cave in New Mexico

NASA Astrophysics Data System (ADS)

Sekhon, N.; Banner, J.; Miller, N. R.; Carlson, P. E.; Breecker, D.

2017-12-01

High-resolution (sub-annual/seasonal) paleoclimate records extending beyond the instrumental period are required to test climate models and better understand how climate warming/cooling and wetting/drying are manifested seasonally. This is particularly the case for areas such as the southwest United States where precipitation and temperature seasonality dictate the regional climate. Study of a 20thcentury stalagmite (Carlson et al., in prep) documented (1) seasonal variation in trace element compositions of a stalagmite from a shallow, well-ventilated cave and (2) demonstrated the seasonal variation in stalagmite Mg to be in agreement with predicted temperature-dependent fractionation between water and calcite. The seasonal nature of variability was constrained by monitoring the cave on a monthly basis (Casteel and Banner, 2015; Carlson et al., in prep). Here we expand on using stalagmites from shallow, well-ventilated caves as archives of seasonally-resolved climate recorders by studying trace element variations in two coeval modern stalagmites (SBFC-1 and SBFC-2) cored from Sitting Bull Falls, southern New Mexico. Seasonal cycles will be confirmed by analyzing Mg, Ba, and Sr in in-situ calcite precipitated on artificial substrates as available (July, Sept., and Nov. 2017). The chronology is constrained by semi-automated peak counting and 14C bomb-peak. In addition, principal component analyses of trace element data identify two primary underlying modes of trace element variability for soil-derived elements (Cu, Zn, and Fe) and bedrock-derived elements (Mg, Sr, and Ba). We hypothesize that the soil-derived elements are transported by seasonal infiltration of organic colloids and the bedrock-derived elements are ­­controlled by variability in cave air temperature, drip water, and calcite growth rate. The two modes of variability will be calibrated against instrumental data over the 20th century. When complete, these new seasonally resolved proxy records will constrain the pattern and mechanism of the regional climate in southwest United States with a focus on drought indicators.

Failure of a systemic lupus erythematosus response index developed from clinical trial data: lessons examined and learned.

PubMed

Forbess, L J; Bresee, C; Wallace, D J; Weisman, M H

2017-08-01

Background Our primary goal was to create an outcome change score index similar to a standard rheumatoid arthritis (RA) model utilizing real-world data in systemic lupus erythematosus (SLE) patients that occurred during their phase 3 trials with a Food and Drug Administration-approved drug. Methods We utilized raw data from trials of belimumab for the treatment of SLE. Data were split 80/20 into training/validation sets. Index variables present in a majority of patients and with face validity were selected. Variables were scored for each patient as percentage improvement from baseline after one year. The percentage of placebo- and drug-treated patients considered improved after the application of various criteria was ascertained. Logistic regression was employed to determine the ability of the new index to predict treatment assignment. Results A total of 1693 subjects had data for analyses. Eight variables were chosen: arthritis, rash, physician global assessment, fatigue, anti-double stranded DNA antibodies, C3, C4 and C-reactive protein. In the training dataset, ≥20% improvement in ≥4 of eight variables produced the largest difference between placebo- and drug-treated patients (22.1%) with an acceptable rate of improved placebo-treated patients (25%). This resulted in an odds ratio for belimumab (10 mg/kg) vs placebo of 2.7 (95% CI: 2.0-3.6; p < 0.001). However, in the validate dataset the odds ratio was not significant at 1.3 (95% CI: 0.8-2.2; p = 0.863). Conclusions The index created from training data did not achieve statistical significance when tested in the validation set. We have speculated why this happened. Is the lack of success of therapeutics for SLE caused by ineffective medications, study design and outcome instruments that fail to inform us, or is the heterogeneity of the disease too daunting? The lessons learned here can help direct future endeavors intended to improve SLE outcome instruments.

Development of a new linearly variable edge filter (LVEF)-based compact slit-less mini-spectrometer

NASA Astrophysics Data System (ADS)

Mahmoud, Khaled; Park, Seongchong; Lee, Dong-Hoon

2018-02-01

This paper presents the development of a compact charge-coupled detector (CCD) spectrometer. We describe the design, concept and characterization of VNIR linear variable edge filter (LVEF)- based mini-spectrometer. The new instrument has been realized for operation in the 300 nm to 850 nm wavelength range. The instrument consists of a linear variable edge filter in front of CCD array. Low-size, light-weight and low-cost could be achieved using the linearly variable filters with no need to use any moving parts for wavelength selection as in the case of commercial spectrometers available in the market. This overview discusses the main components characteristics, the main concept with the main advantages and limitations reported. Experimental characteristics of the LVEFs are described. The mathematical approach to get the position-dependent slit function of the presented prototype spectrometer and its numerical de-convolution solution for a spectrum reconstruction is described. The performance of our prototype instrument is demonstrated by measuring the spectrum of a reference light source.

Exploration of an oculometer-based model of pilot workload

NASA Technical Reports Server (NTRS)

Krebs, M. J.; Wingert, J. W.; Cunningham, T.

1977-01-01

Potential relationships between eye behavior and pilot workload are discussed. A Honeywell Mark IIA oculometer was used to obtain the eye data in a fixed base transport aircraft simulation facility. The data were analyzed to determine those parameters of eye behavior which were related to changes in level of task difficulty of the simulated manual approach and landing on instruments. A number of trends and relationships between eye variables and pilot ratings were found. A preliminary equation was written based on the results of a stepwise linear regression. High variability in time spent on various instruments was related to differences in scanning strategy among pilots. A more detailed analysis of individual runs by individual pilots was performed to investigate the source of this variability more closely. Results indicated a high degree of intra-pilot variability in instrument scanning. No consistent workload related trends were found. Pupil diameter which had demonstrated a strong relationship to task difficulty was extensively re-exmained.

Influence of therapist competence and quantity of cognitive behavioural therapy on suicidal behaviour and inpatient hospitalisation in a randomised controlled trial in borderline personality disorder: further analyses of treatment effects in the BOSCOT study.

PubMed

Norrie, John; Davidson, Kate; Tata, Philip; Gumley, Andrew

2013-09-01

We investigated the treatment effects reported from a high-quality randomized controlled trial of cognitive behavioural therapy (CBT) for 106 people with borderline personality disorder attending community-based clinics in the UK National Health Service - the BOSCOT trial. Specifically, we examined whether the amount of therapy and therapist competence had an impact on our primary outcome, the number of suicidal acts, using instrumental variables regression modelling. Randomized controlled trial. Participants from across three sites (London, Glasgow, and Ayrshire/Arran) were randomized equally to CBT for personality disorders (CBTpd) plus Treatment as Usual or to Treatment as Usual. Treatment as Usual varied between sites and individuals, but was consistent with routine treatment in the UK National Health Service at the time. CBTpd comprised an average 16 sessions (range 0-35) over 12 months. We used instrumental variable regression modelling to estimate the impact of quantity and quality of therapy received (recording activities and behaviours that took place after randomization) on number of suicidal acts and inpatient psychiatric hospitalization. A total of 101 participants provided full outcome data at 2 years post randomization. The previously reported intention-to-treat (ITT) results showed on average a reduction of 0.91 (95% confidence interval 0.15-1.67) suicidal acts over 2 years for those randomized to CBT. By incorporating the influence of quantity of therapy and therapist competence, we show that this estimate of the effect of CBTpd could be approximately two to three times greater for those receiving the right amount of therapy from a competent therapist. Trials should routinely control for and collect data on both quantity of therapy and therapist competence, which can be used, via instrumental variable regression modelling, to estimate treatment effects for optimal delivery of therapy. Such estimates complement rather than replace the ITT results, which are properly the principal analysis results from such trials. © 2013 The British Psychological Society.

Effect of autoclaving on the surfaces of TiN -coated and conventional nickel-titanium rotary instruments.

PubMed

Spagnuolo, G; Ametrano, G; D'Antò, V; Rengo, C; Simeone, M; Riccitiello, F; Amato, M

2012-12-01

To evaluate the effects of repeated autoclave sterilization cycles on surface topography of conventional nickel-titanium ( NiTi ) and titanium nitride ( TiN )-coated rotary instruments. A total of 60 NiTi rotary instruments, 30 ProTaper (Dentsply Maillefer) and 30 TiN -coated AlphaKite (Komet/Gebr. Brasseler), were analysed. Instruments were evaluated in the as-received condition and after 1, 5 and 10 sterilization cycles. After sterilization, the samples were observed using scanning electron microscope (SEM), and surface chemical analysis was performed on each instrument with energy dispersive X-ray spectroscopy (EDS). Moreover, the samples were analysed by atomic force microscopy (AFM), and roughness average (Ra) and the root mean square value (RMS) of the scanned surface profiles were recorded. Data were analysed by means of anova followed by Tukey's test. Scanning electron microscope observations revealed the presence of pitting and deep milling marks in all instruments. EDS analysis confirmed that both types of instruments were composed mainly of nickel and titanium, whilst AlphaKite had additional nitride. After multiple autoclave sterilization cycles, SEM examinations revealed an increase in surface alterations, and EDS values indicated changes in chemical surface composition in all instruments. Ra and RMS values of ProTaper significantly increased after 5 (P = 0.006) and 10 cycles (P = 0.002) with respect to the as-received instruments, whilst AlphaKite showed significant differences compared with the controls after 10 cycles (P = 0.03). Multiple autoclave sterilization cycles modified the surface topography and chemical composition of conventional and TiN -coated NiTi rotary instruments. © 2012 International Endodontic Journal.

Assessment of the wish to hasten death in patients with advanced disease: A systematic review of measurement instruments.

PubMed

Bellido-Pérez, Mercedes; Monforte-Royo, Cristina; Tomás-Sábado, Joaquín; Porta-Sales, Josep; Balaguer, Albert

2017-06-01

Patients with advanced conditions may present a wish to hasten death. Assessing this wish is complex due to the nature of the phenomenon and the difficulty of conceptualising it. To identify and analyse existing instruments for assessing the wish to hasten death and to rate their reported psychometric properties. Systematic review based on PRISMA guidelines. The COnsensus-based Standards for the selection of health Measurement INstruments checklist was used to evaluate the methodological quality of validation studies and the measurement properties of the instrument described. The CINAHL, PsycINFO, Pubmed and Web of Science databases were searched from inception to November 2015. A total of 50 articles involving assessment of the wish to hasten death were included. Eight concerned instrument validation and were evaluated using COnsensus-based Standards for the selection of health Measurement INstruments criteria. They reported data for between two and seven measurement properties, with ratings between fair and excellent. Of the seven instruments identified, the Desire for Death Rating Scale or the Schedule of Attitudes toward Hastened Death feature in 48 of the 50 articles. The Schedule of Attitudes toward Hastened Death is the most widely used and is the instrument whose psychometric properties have been most often analysed. Versions of the Schedule of Attitudes toward Hastened Death are available in five languages other than the original English. This systematic review has analysed existing instruments for assessing the wish to hasten death. It has also explored the methodological quality of studies that have examined the measurement properties of these instruments and offers ratings of the reported properties. These results will be useful to clinicians and researchers with an interest in a phenomenon of considerable relevance to advanced patients.

Assessment of the wish to hasten death in patients with advanced disease: A systematic review of measurement instruments

PubMed Central

Bellido-Pérez, Mercedes; Monforte-Royo, Cristina; Tomás-Sábado, Joaquín; Porta-Sales, Josep; Balaguer, Albert

2016-01-01

Background: Patients with advanced conditions may present a wish to hasten death. Assessing this wish is complex due to the nature of the phenomenon and the difficulty of conceptualising it. Aim: To identify and analyse existing instruments for assessing the wish to hasten death and to rate their reported psychometric properties. Design: Systematic review based on PRISMA guidelines. The COnsensus-based Standards for the selection of health Measurement INstruments checklist was used to evaluate the methodological quality of validation studies and the measurement properties of the instrument described. Data sources: The CINAHL, PsycINFO, Pubmed and Web of Science databases were searched from inception to November 2015. Results: A total of 50 articles involving assessment of the wish to hasten death were included. Eight concerned instrument validation and were evaluated using COnsensus-based Standards for the selection of health Measurement INstruments criteria. They reported data for between two and seven measurement properties, with ratings between fair and excellent. Of the seven instruments identified, the Desire for Death Rating Scale or the Schedule of Attitudes toward Hastened Death feature in 48 of the 50 articles. The Schedule of Attitudes toward Hastened Death is the most widely used and is the instrument whose psychometric properties have been most often analysed. Versions of the Schedule of Attitudes toward Hastened Death are available in five languages other than the original English. Conclusion: This systematic review has analysed existing instruments for assessing the wish to hasten death. It has also explored the methodological quality of studies that have examined the measurement properties of these instruments and offers ratings of the reported properties. These results will be useful to clinicians and researchers with an interest in a phenomenon of considerable relevance to advanced patients. PMID:28124578

The Chinese Family Assessment Instrument (C-FAI): Hierarchical Confirmatory Factor Analyses and Factorial Invariance

ERIC Educational Resources Information Center

Shek, Daniel T. L.; Ma, Cecilia M. S.

2010-01-01

Objective: This paper examines the dimensionality and factorial invariance of the Chinese Family Assessment Instrument (C-FAI) using multigroup confirmatory factor analyses (MCFAs). Method: A total of 3,649 students responded to the C-FAI in a community survey. Results: Results showed that there are five dimensions of the C-FAI (communication,…

Implementation of Head Start Planned Variation: 1970-1971. Part II.

ERIC Educational Resources Information Center

Lukas, Carol Van Deusen; Wohlleb, Cynthia

This volume of appendices is Part II of a study of program implementation in 12 models of Head Start Planned Variation. It presents details of the data analysis, copies of data collection instruments, and additional analyses and statistics. The appendices are: (A) Analysis of Variance Designs, (B) Copies of Instruments, (C) Additional Analyses,…

Effect of cryogenic treatment on nickel-titanium endodontic instruments

PubMed Central

Kim, J. W.; Griggs, J. A.; Regan, J. D.; Ellis, R. A.; Cai, Z.

2005-01-01

Aim To investigate the effects of cryogenic treatment on nickel-titanium endodontic instruments. The null hypothesis was that cryogenic treatment would result in no changes in composition, microhardness or cutting efficiency of nickel-titanium instruments. Methodology Microhardness was measured on 30 nickel-titanium K-files (ISO size 25) using a Vicker’s indenter. Elemental composition was measured on two instruments using X-ray spectroscopy. A nickel-titanium bulk specimen was analysed for crystalline phase composition using X-ray diffraction. Half of the specimens to be used for each analysis were subjected to a cryogenic treatment in liquid nitrogen (−196 °C) for either 3 s (microhardness specimens) or 10 min (other specimens). Cutting efficiency was assessed by recording operator choice using 80 nickel-titanium rotary instruments (ProFile® 20, .06) half of which had been cryogenically treated and had been distributed amongst 14 clinicians. After conditioning by preparing four corresponding canals, each pair of instruments were evaluated for cutting efficiency by a clinician during preparation of one canal system in vitro. A Student’s t-test was used to analyse the microhardness data, and a binomial test was used to analyse the observer choice data. Composition data were analysed qualitatively. Results Cryogenically treated specimens had a significantly higher microhardness than the controls (P < 0.001; β > 0.999). Observers showed a preference for cryogenically treated instruments (61%), but this was not significant (P = 0.21). Both treated and control specimens were composed of 56% Ni, 44% Ti, 0% N (by weight) with a majority in the austenite phase. Conclusions Cryogenic treatment resulted in increased microhardness, but this increase was not detected clinically. There was no measurable change in elemental or crystalline phase composition. PMID:15910471

From Aeolis Palus to the Bagnold Dunes field: Overview of martian soil analyses performed by ChemCam in Gale Crater

NASA Astrophysics Data System (ADS)

Cousin, A.; Meslin, P. Y.; Dehouck, E.; David, G.; Rapin, W.; Schröder, S.; Forni, O.; Gasnault, O.; Williams, A. J.; Lasue, J.; Stein, N.; Ehlmann, B. L.; Payre, V.; Anderson, R. B.; Blaney, D. L.; Bridges, N. T.; Clark, B. C.; Frydenvang, J.; Gasda, P. J.; Johnson, J. R.; Lanza, N.; l'Haridon, J.; Mangold, N.; Maurice, S.; Newsom, H. E.; Ollila, A.; Pinet, P. C.; Sautter, V.; Thomas, N. H.; Wiens, R. C.

2017-12-01

In situ analysis of the chemical and mineralogical composition of the martian soil, and the determination of its volatile inventory, can provide important constraints on the bulk composition of the martian crust, on its igneous diversity, but also on the physical and chemical weathering processes that have altered its primary igneous constituents. Transport processes that have occurred over long geological time scales, however, make this analysis quite complex, as constituents from different unknown sources are mixed together, and may have been sorted according to grain size or density. A meteoritic contribution is also present. Disentangling the influence of each of these processes requires the use of different analytical techniques, at different spatial scales, and at different locations over the planet. We will present an overview of the soil analyses obtained over the past 5 years by the ChemCam instrument on board MSL/Curiosity. Their specificity lies in their small spatial scale ( 300 μm), close to the average grains' size. At this scale, chemical trends are observed, resulting from the mixing of different end-members with different grain sizes: coarse felsic grains of likely local origin, fine grains with a basaltic composition close to soil compositions observed at other landing sites, but distinct from local rocks, and a fine-grained, Si-poor, volatile-rich component probably associated with the XRD-amorphous component detected by the CheMin instrument. The thin ablation depth associated with each laser shot ( 1 μm) enables us to analyse the surface of the grains, which is characterized by a strong, but variable hydrogen signal. These analyses provide constraints on the composition of a possible alteration rind or coating present at their surface. An extensive, multi-instrument investigation of active dunes (barchan and linear dunes) has also been carried out, revealing slight chemical differences with surrounding soils, and a more homogeneous composition, although chemical variations as a function of grain size are observed, with coarser grains enriched in mafic minerals. These results illustrate the still ongoing influence of aeolian transport on the physical sorting of loose, unconsolidated sediments. These results also provide ground truth for orbital IR observations of aeolian bedforms.

Control theory analysis of a three-axis VTOL flight director. M.S. Thesis - Pennsylvania State Univ.

NASA Technical Reports Server (NTRS)

Niessen, F. R.

1971-01-01

A control theory analysis of a VTOL flight director and the results of a fixed-based simulator evaluation of the flight-director commands are discussed. The VTOL configuration selected for this study is a helicopter-type VTOL which controls the direction of the thrust vector by means of vehicle-attitude changes and, furthermore, employs high-gain attitude stabilization. This configuration is the same as one which was simulated in actual instrument flight tests with a variable stability helicopter. Stability analyses are made for each of the flight-director commands, assuming a single input-output, multi-loop system model for each control axis. The analyses proceed from the inner-loops to the outer-loops, using an analytical pilot model selected on the basis of the innermost-loop dynamics. The time response of the analytical model of the system is primarily used to adjust system gains, while root locus plots are used to identify dominant modes and mode interactions.

The impact of Mexico's conditional cash transfer programme, Oportunidades, on birthweight.

PubMed

Barber, Sarah L; Gertler, Paul J

2008-11-01

To evaluate the impact of Oportunidades, a large-scale, conditional cash transfer programme in Mexico, on birthweight. The programme provides cash transfers to low-income, rural households in Mexico, conditional on accepting nutritional supplements health education, and health care. The primary analyses used retrospective reports from 840 women in poor rural communities participating in an effectiveness study and randomly assigned to incorporation into the programme in 1998 or 1999 across seven Mexican states. Pregnant women in participating households received nutrition supplements and health care, and accepted cash transfers. Using multivariate and instrumental variable analyses, we estimated the impact of the programme on birthweight in grams and low birthweight (<2500 g), receipt of any pre-natal care, and number of pre-natal visits. Oportunidades beneficiary status was associated with 127.3 g higher birthweight among participating women and a 4.6 percentage point reduction in low birthweight. The Oportunidades conditional cash transfer programme improved birthweight outcomes. This finding is relevant to countries implementing conditional cash transfer programmes.

Partners or Partners in Crime? The Relationship Between Criminal Associates and Criminogenic Thinking.

PubMed

Whited, William H; Wagar, Laura; Mandracchia, Jon T; Morgan, Robert D

2017-04-01

Meta-analyses examining the risk factors for recidivism have identified the importance of ties with criminal associates as well as thoughts and attitudes conducive to the continuance of criminal behavior (e.g., criminogenic thinking). Criminologists have theorized that a direct relationship exists between the association with criminal peers and the development of criminogenic thinking. The present study empirically explored the relationship between criminal associates and criminogenic thinking in 595 adult male inmates in the United States. It was hypothesized that the proportion of free time spent with and number of criminal associates would be associated with criminogenic thinking, as measured by two self-report instruments, the Measure of Offender Thinking Styles-Revised (MOTS-R) and the Psychological Inventory of Criminal Thinking Styles (PICTS). Hierarchal linear regression analyses demonstrated that the proportion of free time spent with criminal associates statistically predicted criminogenic thinking when controlling for demographic variables. The implications of these findings on correctional practice (including assessment and intervention) as well as future research are discussed.

Social sustainability in healthcare facilities: a rating tool for analysing and improving social aspects in environments of care.

PubMed

Capolongo, Stefano; Gola, Marco; di Noia, Michela; Nickolova, Maria; Nachiero, Dario; Rebecchi, Andrea; Settimo, Gaetano; Vittori, Gail; Buffoli, Maddalena

2016-01-01

Nowadays several rating systems exist for the evaluation of the sustainability of buildings, but often their focus is limited to environmental and efficiency aspects. Hospitals are complex constructions in which many variables affect hospital processes. Therefore, a research group has developed a tool for the evaluation of sustainability in healthcare facilities. The paper analyses social sustainability issues through a tool which evaluates users' perception from a the quality and well-being perspective. It presents a hierarchical structure composed of a criteria and indicators system which is organised through a weighing system calculated by using the Analytic Network Process. The output is the definition of a tool which evaluates how Humanisation, Comfort and Distribution criteria can affect the social sustainability of a building. Starting from its application, it is evident that the instrument enables the improvement of healthcare facilities through several design and organisational suggestions for achieving healing and sustainable architectures.

Reconstructing pre-instrumental streamflow in Eastern Australia using a water balance approach

NASA Astrophysics Data System (ADS)

Tozer, C. R.; Kiem, A. S.; Vance, T. R.; Roberts, J. L.; Curran, M. A. J.; Moy, A. D.

2018-03-01

Streamflow reconstructions based on paleoclimate proxies provide much longer records than the short instrumental period records on which water resource management plans are currently based. In Australia there is a lack of in-situ high resolution paleoclimate proxy records, but remote proxies with teleconnections to Australian climate have utility in producing streamflow reconstructions. Here we investigate, via a case study for a catchment in eastern Australia, the novel use of an Antarctic ice-core based rainfall reconstruction within a Budyko-framework to reconstruct ∼1000 years of annual streamflow. The resulting streamflow reconstruction captures interannual to decadal variability in the instrumental streamflow, validating both the use of the ice core rainfall proxy record and the Budyko-framework method. In the preinstrumental era the streamflow reconstruction shows longer wet and dry epochs and periods of streamflow variability that are higher than observed in the instrumental era. Importantly, for both the instrumental record and preinstrumental reconstructions, the wet (dry) epochs in the rainfall record are shorter (longer) in the streamflow record and this non-linearity must be considered when inferring hydroclimatic risk or historical water availability directly from rainfall proxy records alone. These insights provide a better understanding of present infrastructure vulnerability in the context of past climate variability for eastern Australia. The streamflow reconstruction presented here also provides a better understanding of the range of hydroclimatic variability possible, and therefore represents a more realistic baseline on which to quantify the potential impacts of anthropogenic climate change on water security.

The Use of IMMUs in a Water Environment: Instrument Validation and Application of 3D Multi-Body Kinematic Analysis in Medicine and Sport

PubMed Central

Mangia, Anna Lisa; Cortesi, Matteo; Fantozzi, Silvia; Giovanardi, Andrea; Borra, Davide; Gatta, Giorgio

2017-01-01

The aims of the present study were the instrumental validation of inertial-magnetic measurements units (IMMUs) in water, and the description of their use in clinical and sports aquatic applications applying customized 3D multi-body models. Firstly, several tests were performed to map the magnetic field in the swimming pool and to identify the best volume for experimental test acquisition with a mean dynamic orientation error lower than 5°. Successively, the gait and the swimming analyses were explored in terms of spatiotemporal and joint kinematics variables. The extraction of only spatiotemporal parameters highlighted several critical issues and the joint kinematic information has shown to be an added value for both rehabilitative and sport training purposes. Furthermore, 3D joint kinematics applied using the IMMUs provided similar quantitative information than that of more expensive and bulky systems but with a simpler and faster setup preparation, a lower time consuming processing phase, as well as the possibility to record and analyze a higher number of strides/strokes without limitations imposed by the cameras. PMID:28441739

Effectiveness of unit-based pricing of waste in the Netherlands: applying a general equilibrium model.

PubMed

van Beukering, Pieter J H; Bartelings, Heleen; Linderhof, Vincent G M; Oosterhuis, Frans H

2009-11-01

Differential and variable rates (DVR) in waste collection charging give a price incentive to households to reduce their waste and increase recycling. International empirical evidence confirms the effectiveness of DVR schemes, with limited unwanted side effects. In the Netherlands, currently some 20% of the population is charged at DVR. This is less than in several other countries. Taking into account differences between types of households and dwellings, this study analyses various scenarios for extended use of DVR in the Netherlands. The analysis shows that further penetration of DVR is a cost-effective instrument for waste reduction and more recycling. Moreover, DVR can itself be seen as a necessary condition for the successful implementation of other economic instruments, such as waste taxes. It is therefore recommended to stimulate municipalities to adopt DVR schemes in the Netherlands, accompanied by the provision of adequate facilities for waste separation by households. Before introducing DVR in 'very strongly urbanized' municipalities (i.e. the 12 largest cities in the Netherlands) a pilot experiment in one of them might be useful to test the behavioral response in this category.

The Use of IMMUs in a Water Environment: Instrument Validation and Application of 3D Multi-Body Kinematic Analysis in Medicine and Sport.

PubMed

Mangia, Anna Lisa; Cortesi, Matteo; Fantozzi, Silvia; Giovanardi, Andrea; Borra, Davide; Gatta, Giorgio

2017-04-22

The aims of the present study were the instrumental validation of inertial-magnetic measurements units (IMMUs) in water, and the description of their use in clinical and sports aquatic applications applying customized 3D multi-body models. Firstly, several tests were performed to map the magnetic field in the swimming pool and to identify the best volume for experimental test acquisition with a mean dynamic orientation error lower than 5°. Successively, the gait and the swimming analyses were explored in terms of spatiotemporal and joint kinematics variables. The extraction of only spatiotemporal parameters highlighted several critical issues and the joint kinematic information has shown to be an added value for both rehabilitative and sport training purposes. Furthermore, 3D joint kinematics applied using the IMMUs provided similar quantitative information than that of more expensive and bulky systems but with a simpler and faster setup preparation, a lower time consuming processing phase, as well as the possibility to record and analyze a higher number of strides/strokes without limitations imposed by the cameras.

Development and evaluation of a case group concept for inpatients with mental disorders in Germany: using self-report and expert-rated instruments.

PubMed

Andreas, Sylke; Dirmaier, Jörg; Harfst, Timo; Kawski, Stephan; Koch, Uwe; Schulz, Holger

2009-03-01

The aim of this study was to evaluate a case-mix system to classify inpatients with mental disorders in Germany by means of self-report and expert-rated instruments. The use of case-mix systems enhances the transparency of performance and cost structure and can thus improve the quality of mental health care. We analysed a consecutive sample of 1677 inpatients with mental disorders from 11 hospitals using regression tree analysis. The model assigns patients to 17 groups, accounting for 17% of the variance for duration of stay. Patients with eating disorders had a longer duration of stay than patients with anxiety disorder, duration of mental illness of less than 3-5 years, lower levels of interpersonal problems and higher occupational position. The results showed that besides diagnosis, variables such as duration of illness and interpersonal problems are important for classifying inpatients with mental disorders. The results of the study should be critically reviewed regarding the empirical results of other studies and the appropriateness of case group concepts for inpatients with mental disorders.

Pain after root canal treatment with different instruments: A systematic review and meta-analysis.

PubMed

Sun, Chengjun; Sun, Jicheng; Tan, Minmin; Hu, Bo; Gao, Xiang; Song, Jinlin

2018-03-07

The aims of this systematic review were to compare the incidence and intensity of postoperative pain after single-visit root canal treatment using manual, rotary and reciprocating instruments. An extensive literature search in PubMed, EMBASE, Cochrane Library, and Web of Science was performed to identify investigations that evaluated the effects of different instruments on post-endodontic pain. Meta-analyses and additional analyses, including subgroup and sensitivity analyses, were conducted. We included seventeen trials in this study. Pooled results showed that patients treated with rotary instruments experienced a significantly lower incidence of postoperative pain (RR, 0.32, P = 0.0005) and reduced pain intensity than did patients treated with manual instruments. In addition, patients treated with multiple rotary-file systems experienced a significantly lower incidence of postoperative pain than did those treated with reciprocating systems (RR, 0.73; P < 0.0001). The use of rotary instruments contributed to a lower incidence and intensity of postoperative pain than did the use of hand files in patients who received single-visit root canal treatment. In addition, the use of multiple rotary-file systems contributed to a lower incidence of postoperative pain than did the use of reciprocating systems. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

8 years of Solar Spectral Irradiance Variability Observed from the ISS with the SOLAR/SOLSPEC Instrument

NASA Astrophysics Data System (ADS)

Damé, Luc; Bolsée, David; Meftah, Mustapha; Irbah, Abdenour; Hauchecorne, Alain; Bekki, Slimane; Pereira, Nuno; Cessateur, Marchand; Gäel; , Marion; et al.

2016-10-01

Accurate measurements of Solar Spectral Irradiance (SSI) are of primary importance for a better understanding of solar physics and of the impact of solar variability on climate (via Earth's atmospheric photochemistry). The acquisition of a top of atmosphere reference solar spectrum and of its temporal and spectral variability during the unusual solar cycle 24 is of prime interest for these studies. These measurements are performed since April 2008 with the SOLSPEC spectro-radiometer from the far ultraviolet to the infrared (166 nm to 3088 nm). This instrument, developed under a fruitful LATMOS/BIRA-IASB collaboration, is part of the Solar Monitoring Observatory (SOLAR) payload, externally mounted on the Columbus module of the International Space Station (ISS). The SOLAR mission, with its actual 8 years duration, will cover almost the entire solar cycle 24. We present here the in-flight operations and performances of the SOLSPEC instrument, including the engineering corrections, calibrations and improved know-how procedure for aging corrections. Accordingly, a SSI reference spectrum from the UV to the NIR will be presented, together with its variability in the UV, as measured by SOLAR/SOLSPEC for 8 years. Uncertainties on these measurements and comparisons with other instruments will be briefly discussed.

Towards Student Instrumentation of Computer-Based Algebra Systems in University Courses

ERIC Educational Resources Information Center

Stewart, Sepideh; Thomas, Michael O. J.; Hannah, John

2005-01-01

There are many perceived benefits of using technology, such as computer algebra systems, in undergraduate mathematics courses. However, attaining these benefits sometimes proves elusive. Some of the key variables are the teaching approach and the student instrumentation of the technology. This paper considers the instrumentation of computer-based…

Instructional Interactions of Kindergarten Mathematics Classrooms: Validating a Direct Observation Instrument

ERIC Educational Resources Information Center

Doabler, Christian; Smolkowski, Keith; Fien, Hank; Kosty, Derek B.; Cary, Mari Strand

2010-01-01

In this paper, the authors report research focused directly on the validation of the Coding of Academic Teacher-Student interactions (CATS) direct observation instrument. They use classroom information gathered by the CATS instrument to better understand the potential mediating variables hypothesized to influence student achievement. Their study's…

26 CFR 1.1275-5 - Variable rate debt instruments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... nonpublicly traded property. A debt instrument (other than a tax-exempt obligation) that would otherwise... variations in the cost of newly borrowed funds in the currency in which the debt instrument is denominated... on the yield of actively traded personal property (within the meaning of section 1092(d)(1)). (ii...

Three-dimensional variational assimilation of MODIS aerosol optical depth: Implementation and application to a dust storm over East Asia

NASA Astrophysics Data System (ADS)

Liu, Zhiquan; Liu, Quanhua; Lin, Hui-Chuan; Schwartz, Craig S.; Lee, Yen-Huei; Wang, Tijian

2011-12-01

Assimilation of the Moderate Resolution Imaging Spectroradiometer (MODIS) total aerosol optical depth (AOD) retrieval products (at 550 nm wavelength) from both Terra and Aqua satellites have been developed within the National Centers for Environmental Prediction (NCEP) Gridpoint Statistical Interpolation (GSI) three-dimensional variational (3DVAR) data assimilation system. This newly developed algorithm allows, in a one-step procedure, the analysis of 3-D mass concentration of 14 aerosol variables from the Goddard Chemistry Aerosol Radiation and Transport (GOCART) module. The Community Radiative Transfer Model (CRTM) was extended to calculate AOD using GOCART aerosol variables as input. Both the AOD forward model and corresponding Jacobian model were developed within the CRTM and used in the 3DVAR minimization algorithm to compute the AOD cost function and its gradient with respect to 3-D aerosol mass concentration. The impact of MODIS AOD data assimilation was demonstrated by application to a dust storm from 17 to 24 March 2010 over East Asia. The aerosol analyses initialized Weather Research and Forecasting/Chemistry (WRF/Chem) model forecasts. Results indicate that assimilating MODIS AOD substantially improves aerosol analyses and subsequent forecasts when compared to MODIS AOD, independent AOD observations from the Aerosol Robotic Network (AERONET) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument, and surface PM10 (particulate matter with diameters less than 10 μm) observations. The newly developed AOD data assimilation system can serve as a tool to improve simulations of dust storms and general air quality analyses and forecasts.

When Significant Others Suffer: German Validation of the Burden Assessment Scale (BAS)

PubMed Central

Hunger, Christina; Krause, Lena; Hilzinger, Rebecca; Ditzen, Beate; Schweitzer, Jochen

2016-01-01

There is a need of an economical, reliable, and valid instrument in the German-speaking countries to measure the burden of relatives who care for mentally ill persons. We translated the Burden Assessment Scale (BAS) and conducted a study investigating factor structure, psychometric quality and predictive validity. We used confirmative factor analyses (CFA, maximum-likelihood method) to examine the dimensionality of the German BAS in a sample of 215 relatives (72% women; M = 32 years, SD = 14, range: 18 to 77; 39% employed) of mentally ill persons (50% (ex-)partner or (best) friend; M = 32 years, SD = 13, range 8 to 64; main complaints were depression and/or anxiety). Cronbach’s α determined the internal consistency. We examined predictive validity using regression analyses including the BAS and validated scales of social systems functioning (Experience In Social Systems Questionnaire, EXIS.pers, EXIS.org) and psychopathology (Brief Symptom Inventory, BSI). Variables that might have influenced the dependent variables (e.g. age, gender, education, employment and civil status) were controlled by their introduction in the first step, and the BAS in the second step of the regression analyses. A model with four correlated factors (Disrupted Activities, Personal Distress, Time Perspective, Guilt) showed the best fit. With respect to the number of items included, the internal consistency was very good. The modified German BAS predicted relatives’ social systems functioning and psychopathology. The economical design makes the 19-item BAS promising for practice-oriented research, and for studies under time constraints. Strength, limitations and future directions are discussed. PMID:27764109

Work-related problems in multiple sclerosis: a literature review on its associates and determinants.

PubMed

Raggi, Alberto; Covelli, Venusia; Schiavolin, Silvia; Scaratti, Chiara; Leonardi, Matilde; Willems, Michelle

2016-01-01

To explore which variables are associated to or determinants of work-related difficulties or unemployment in persons with multiple sclerosis (MS). Papers published between 1993 and February 2015 were included. Quality was judged as poor, acceptable, good or excellent. Determinants were extracted from prospective and retrospective data, associated variables from cross-sectional data; variables were grouped by similarity. Evidence was judged as strong if there were at least two good studies reporting the same results; limited if there was only one good and some acceptable studies. Forty-two papers were selected, for a total of 31,192 patients (75% females). Work-related difficulties were referred as unemployment, lower amount of worked hours or job cessation. Strong evidence of impact over work-related difficulties was found for a core set of variables, i.e., expanded disability status scale, MS duration, patients' age, fatigue and walking problems. Little evidence exists on the impact of contextual factors. Most of the variables identified as associated to or determinants of work-related difficulties can be treated through rehabilitative interventions. It is important that future research addresses not only unemployment issues in MS, but also the amount and severity of problems affecting work-related tasks relying on specific assessment instruments. Multiple sclerosis (MS) affects young persons of working age and limitation in work activities is part of MS-related disability, but they are not consistently addressed in MS research: EDSS, MS duration, patients' age, fatigue, walking problems, cognitive and neuropsychological impairments were the factors most commonly found as associated to or determinant of difficulties with work. Evidence exists that rehabilitation interventions are effective for fatigue, cognitive impairment, mobility and walking difficulties. However, research did not address the impact of rehabilitation programmes on vocational outcomes. Rehabilitation researchers should include MS-specific assessment instruments for work-related difficulties to standardised clinical protocols, so that the benefits of rehabilitation on persons' ability to work can be demonstrated directly: in this way, cost-benefit balance analyses can be added to the evaluation of treatment effectiveness.

Multiscale temporal variability and regional patterns in 555 years of conterminous U.S. streamflow

NASA Astrophysics Data System (ADS)

Ho, Michelle; Lall, Upmanu; Sun, Xun; Cook, Edward R.

2017-04-01

The development of paleoclimate streamflow reconstructions in the conterminous United States (CONUS) has provided water resource managers with improved insights into multidecadal and centennial scale variability that cannot be reliably detected using shorter instrumental records. Paleoclimate streamflow reconstructions have largely focused on individual catchments limiting the ability to quantify variability across the CONUS. The Living Blended Drought Atlas (LBDA), a spatially and temporally complete 555 year long paleoclimate record of summer drought across the CONUS, provides an opportunity to reconstruct and characterize streamflow variability at a continental scale. We explore the validity of the first paleoreconstructions of streamflow that span the CONUS informed by the LBDA targeting a set of U.S. Geological Survey streamflow sites. The reconstructions are skillful under cross validation across most of the country, but the variance explained is generally low. Spatial and temporal structures of streamflow variability are analyzed using hierarchical clustering, principal component analysis, and wavelet analyses. Nine spatially coherent clusters are identified. The reconstructions show signals of contemporary droughts such as the Dust Bowl (1930s) and 1950s droughts. Decadal-scale variability was detected in the late 1900s in the western U.S., however, similar modes of temporal variability were rarely present prior to the 1950s. The twentieth century featured longer wet spells and shorter dry spells compared with the preceding 450 years. Streamflows in the Pacific Northwest and Northeast are negatively correlated with the central U.S. suggesting the potential to mitigate some drought impacts by balancing economic activities and insurance pools across these regions during major droughts.

Geophysics From Terrestrial Time-Variable Gravity Measurements

NASA Astrophysics Data System (ADS)

Van Camp, Michel; de Viron, Olivier; Watlet, Arnaud; Meurers, Bruno; Francis, Olivier; Caudron, Corentin

2017-12-01

In a context of global change and increasing anthropic pressure on the environment, monitoring the Earth system and its evolution has become one of the key missions of geosciences. Geodesy is the geoscience that measures the geometric shape of the Earth, its orientation in space, and gravity field. Time-variable gravity, because of its high accuracy, can be used to build an enhanced picture and understanding of the changing Earth. Ground-based gravimetry can determine the change in gravity related to the Earth rotation fluctuation, to celestial body and Earth attractions, to the mass in the direct vicinity of the instruments, and to vertical displacement of the instrument itself on the ground. In this paper, we review the geophysical questions that can be addressed by ground gravimeters used to monitor time-variable gravity. This is done in relation to the instrumental characteristics, noise sources, and good practices. We also discuss the next challenges to be met by ground gravimetry, the place that terrestrial gravimetry should hold in the Earth observation system, and perspectives and recommendations about the future of ground gravity instrumentation.

To justify or excuse?: A meta-analytic review of the effects of explanations.

PubMed

Shaw, John C; Wild, Eric; Colquitt, Jason A

2003-06-01

The authors used R. Folger and R. Cropanzano's (1998, 2001) fairness theory to derive predictions about the effects of explanation provision and explanation adequacy on justice judgments and cooperation, retaliation, and withdrawal responses. The authors also used the theory to identify potential moderators of those effects, including the type of explanation (justification vs. excuse), outcome favorability, and study context. The authors' predictions were tested by using meta-analyses of 54 independent samples. The results showed strong effects of explanations on both the justice and response variables. Moreover, explanations were more beneficial when they took the form of excuses rather than justifications, when they were given after unfavorable outcomes, and when they were given in contexts with instrumental, relational, and moral implications.

An examination of the hexokinase method for serum glucose assay using external quality assessment data.

PubMed

Westwood, A; Bullock, D G; Whitehead, T P

1986-01-01

Hexokinase methods for serum glucose assay appeared to give slightly but consistently higher inter-laboratory coefficients of variation than all methods combined in the UK External Quality Assessment Scheme; their performance over a two-year period was therefore compared with that for three groups of glucose oxidase methods. This assessment showed no intrinsic inferiority in the hexokinase method. The greater variation may be due to the more heterogeneous group of instruments, particularly discrete analysers, on which the method is used. The Beckman Glucose Analyzer and Astra group (using a glucose oxidase method) showed the least inter-laboratory variability but also the lowest mean value. No comment is offered on the absolute accuracy of any of the methods.

Astronomy sortie mission definition study. Addendum: Follow-on analyses

NASA Technical Reports Server (NTRS)

1973-01-01

Results of design analyses, trade studies, and planning data of the Astronomy Sortie Mission Definition Study are presented. An in-depth analysis of UV instruments, nondeployed solar payload, and on-orbit access is presented. Planning data are considered, including the cost and schedules associated with the astronomy instruments and/or support hardware. Costs are presented in a parametric fashion.

Effect of corruption on healthcare satisfaction in post-soviet nations: A cross-country instrumental variable analysis of twelve countries.

PubMed

Habibov, Nazim

2016-03-01

There is the lack of consensus about the effect of corruption on healthcare satisfaction in transitional countries. Interpreting the burgeoning literature on this topic has proven difficult due to reverse causality and omitted variable bias. In this study, the effect of corruption on healthcare satisfaction is investigated in a set of 12 Post-Socialist countries using instrumental variable regression on the sample of 2010 Life in Transition survey (N = 8655). The results indicate that experiencing corruption significantly reduces healthcare satisfaction. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

Influence of multiple clinical use on fatigue resistance of ProTaper rotary nickel-titanium instruments.

PubMed

Vieira, E P; França, E C; Martins, R C; Buono, V T L; Bahia, M G A

2008-02-01

To examine the influence of clinical use on the occurrence of deformation and fracture and on the fatigue resistance of ProTaper rotary instruments. Root canal treatments were performed on patients using the ProTaper rotary system. Ten sets of instruments were used by an experienced endodontist, each set in five molars. Another 10 sets of instruments were used by the same operator, each set in eight molars. In addition, 10 sets of instruments were used, each set in five molars, by undergraduate students with no clinical experience with the system. After clinical use, S1, S2, F1 and F2 instruments were analysed for damage by optical and scanning electron microscopy. The used sets, along with a control group of 12 sets of new instruments, were then tested in a bench device for fatigue resistance. The use of the ProTaper rotary instruments by an experienced endodontist allowed for the cleaning and shaping of the root canal system of up to eight molars without fracture. During the students work, six instruments fractured. Fatigue resistance decreased upon clinical use for all instruments analysed. Fatigue resistance of used instruments was reduced, but no significant change was observed amongst the instruments used for shaping the canals of five and eight molars. Operator experience affected the occurrence of fracture and plastic deformation during shaping.

Using Instruments for Tactical Assessment in Physical Education and Extra-Curricular Sports

ERIC Educational Resources Information Center

Arias-Estero, José; Castejón, Francisco

2014-01-01

The aim was to analyse the features concerning the applicational purpose and strategy of the most common instruments used to assess game tactics both in Physical Education (PE) and in extra-curricular sport contexts. The review focused on two instruments: the Game Performance Assessment Instrument (GPAI) and the Team Sport Assessment Procedure…

Overlooking the obvious: a meta-analytic comparison of digit symbol coding tasks and other cognitive measures in schizophrenia.

PubMed

Dickinson, Dwight; Ramsey, Mary E; Gold, James M

2007-05-01

In focusing on potentially localizable cognitive impairments, the schizophrenia meta-analytic literature has overlooked the largest single impairment: on digit symbol coding tasks. To compare the magnitude of the schizophrenia impairment on coding tasks with impairments on other traditional neuropsychological instruments. MEDLINE and PsycINFO electronic databases and reference lists from identified articles. English-language studies from 1990 to present, comparing performance of patients with schizophrenia and healthy controls on coding tasks and cognitive measures representing at least 2 other cognitive domains. Of 182 studies identified, 40 met all criteria for inclusion in the meta-analysis. Means, standard deviations, and sample sizes were extracted for digit symbol coding and 36 other cognitive variables. In addition, we recorded potential clinical moderator variables, including chronicity/severity, medication status, age, and education, and potential study design moderators, including coding task variant, matching, and study publication date. Main analyses synthesized data from 37 studies comprising 1961 patients with schizophrenia and 1444 comparison subjects. Combination of mean effect sizes across studies by means of a random effects model yielded a weighted mean effect for digit symbol coding of g = -1.57 (95% confidence interval, -1.66 to -1.48). This effect compared with a grand mean effect of g = -0.98 and was significantly larger than effects for widely used measures of episodic memory, executive functioning, and working memory. Moderator variable analyses indicated that clinical and study design differences between studies had little effect on the coding task effect. Comparison with previous meta-analyses suggested that current results were representative of the broader literature. Subsidiary analysis of data from relatives of patients with schizophrenia also suggested prominent coding task impairments in this group. The 5-minute digit symbol coding task, reliable and easy to administer, taps an information processing inefficiency that is a central feature of the cognitive deficit in schizophrenia and deserves systematic investigation.

Regularization Methods for High-Dimensional Instrumental Variables Regression With an Application to Genetical Genomics

PubMed Central

Lin, Wei; Feng, Rui; Li, Hongzhe

2014-01-01

In genetical genomics studies, it is important to jointly analyze gene expression data and genetic variants in exploring their associations with complex traits, where the dimensionality of gene expressions and genetic variants can both be much larger than the sample size. Motivated by such modern applications, we consider the problem of variable selection and estimation in high-dimensional sparse instrumental variables models. To overcome the difficulty of high dimensionality and unknown optimal instruments, we propose a two-stage regularization framework for identifying and estimating important covariate effects while selecting and estimating optimal instruments. The methodology extends the classical two-stage least squares estimator to high dimensions by exploiting sparsity using sparsity-inducing penalty functions in both stages. The resulting procedure is efficiently implemented by coordinate descent optimization. For the representative L1 regularization and a class of concave regularization methods, we establish estimation, prediction, and model selection properties of the two-stage regularized estimators in the high-dimensional setting where the dimensionality of co-variates and instruments are both allowed to grow exponentially with the sample size. The practical performance of the proposed method is evaluated by simulation studies and its usefulness is illustrated by an analysis of mouse obesity data. Supplementary materials for this article are available online. PMID:26392642

[Survey of analytical works for drugs at emergency and critical care centers with high-performance instruments provided by the Ministry of Health and Welfare (at present: Ministry of Health, Labour, and Welfare) in fiscal 1998--continuation of survey with 2008 survey results as point of reference].

PubMed

Saito, Takeshi; Tominaga, Aya; Nozawa, Mayu; Unei, Hiroko; Hatano, Yayoi; Fujita, Yuji; Iseki, Ken; Hori, Yasushi

2013-09-01

In a 2008 survey of the 73 emergency and critical care centers around the nation that were equipped with the drug and chemical analytical instrument provided by the Ministry of Welfare (currently the Ministry of Health, Labour, and Welfare) in 1998, 36 of those facilities were using the analytical instruments. Of these 36 facilities, a follow-up survey of the 17 facilities that recorded 50 or analyses per year. Responses were gained from 16 of the facilities and we learned that of those, 14 facilities (87.5%) were conducting analyses using the instrument. There was a positive mutual correlation between the annual number of cases of the 14 facilities conducting analyses with the instrument and the number of work hours. Depending on the instrument in use, average analytical instrument parts and maintenance expenses were roughly three million yen and consumables required a maximum three million yen for analysis of 51-200 cases per year. From this, we calculate that such expenses can be covered under the allowed budget for advanced emergency and critical care centers of 5,000 NHI points (1 point = 10 yen). We found there were few facilities using the instrument for all 15 of the toxic substances recommended for testing by the Japanese Society for Clinical Toxicology. There tended to be no use of the analytical instrument for compounds with no toxicology cases. However, flexible responses were noted at each facility in relation to frequently analyzed compounds. It is thought that a reevaluation of compounds subject to analysis is required.

Correlates of walking and cycling for transport and recreation: factor structure, reliability and behavioural associations of the perceptions of the environment in the neighbourhood scale (PENS)

PubMed Central

2013-01-01

Background Emerging evidence suggests that walking and cycling for different purposes such as transport or recreation may be associated with different attributes of the physical environment. Few studies to date have examined these behaviour-specific associations, particularly in the UK. This paper reports on the development, factor structure and test-retest reliability of a new scale assessing perceptions of the environment in the neighbourhood (PENS) and the associations between perceptions of the environment and walking and cycling for transport and recreation. Methods A new 13-item scale was developed for assessing adults’ perceptions of the environment in the neighbourhood (PENS). Three sets of analyses were conducted using data from two sources. Exploratory and confirmatory factor analyses were used to identify a set of summary environmental variables using data from the iConnect baseline survey (n = 3494); test-retest reliability of the individual and summary environmental items was established using data collected in a separate reliability study (n = 166); and multivariable logistic regression was used to determine the associations of the environmental variables with walking for transport, walking for recreation, cycling for transport and cycling for recreation, using iConnect baseline survey data (n = 2937). Results Four summary environmental variables (traffic safety, supportive infrastructure, availability of local amenities and social order), one individual environmental item (street connectivity) and a variable encapsulating general environment quality were identified for use in further analyses. Intraclass correlations of these environmental variables ranged from 0.44 to 0.77 and were comparable to those seen in other similar scales. After adjustment for demographic and other environmental factors, walking for transport was associated with supportive infrastructure, availability of local amenities and general environment quality; walking for recreation was associated with supportive infrastructure; and cycling for transport was associated only with street connectivity. There was limited evidence of any associations between environmental attributes and cycling for recreation. Conclusion PENS is acceptable as a short instrument for assessing perceptions of the urban environment. Previous findings that different attributes of the environment may be associated with different behaviours are confirmed. Policy action to create supportive environments may require a combination of environmental improvements to promote walking and cycling for different purposes. PMID:23815872

Reconciling differences in stratospheric ozone composites

NASA Astrophysics Data System (ADS)

Ball, William T.; Alsing, Justin; Mortlock, Daniel J.; Rozanov, Eugene V.; Tummon, Fiona; Haigh, Joanna D.

2017-10-01

Observations of stratospheric ozone from multiple instruments now span three decades; combining these into composite datasets allows long-term ozone trends to be estimated. Recently, several ozone composites have been published, but trends disagree by latitude and altitude, even between composites built upon the same instrument data. We confirm that the main causes of differences in decadal trend estimates lie in (i) steps in the composite time series when the instrument source data changes and (ii) artificial sub-decadal trends in the underlying instrument data. These artefacts introduce features that can alias with regressors in multiple linear regression (MLR) analysis; both can lead to inaccurate trend estimates. Here, we aim to remove these artefacts using Bayesian methods to infer the underlying ozone time series from a set of composites by building a joint-likelihood function using a Gaussian-mixture density to model outliers introduced by data artefacts, together with a data-driven prior on ozone variability that incorporates knowledge of problems during instrument operation. We apply this Bayesian self-calibration approach to stratospheric ozone in 10° bands from 60° S to 60° N and from 46 to 1 hPa (˜ 21-48 km) for 1985-2012. There are two main outcomes: (i) we independently identify and confirm many of the data problems previously identified, but which remain unaccounted for in existing composites; (ii) we construct an ozone composite, with uncertainties, that is free from most of these problems - we call this the BAyeSian Integrated and Consolidated (BASIC) composite. To analyse the new BASIC composite, we use dynamical linear modelling (DLM), which provides a more robust estimate of long-term changes through Bayesian inference than MLR. BASIC and DLM, together, provide a step forward in improving estimates of decadal trends. Our results indicate a significant recovery of ozone since 1998 in the upper stratosphere, of both northern and southern midlatitudes, in all four composites analysed, and particularly in the BASIC composite. The BASIC results also show no hemispheric difference in the recovery at midlatitudes, in contrast to an apparent feature that is present, but not consistent, in the four composites. Our overall conclusion is that it is possible to effectively combine different ozone composites and account for artefacts and drifts, and that this leads to a clear and significant result that upper stratospheric ozone levels have increased since 1998, following an earlier decline.

Expanding the enablement framework and testing an evaluative instrument for diabetes patient education.

PubMed

Leeseberg Stamler, L; Cole, M M; Patrick, L J

2001-08-01

Strategies to delay or prevent complications from diabetes include diabetes patient education. Diabetes educators seek to provide education that meets the needs of clients and influences positive health outcomes. (1) To expand prior research exploring an enablement framework for patient education by examining perceptions of patient education by persons with diabetes and (2) to test the mastery of stress instrument (MSI) as a potential evaluative instrument for patient education. Triangulated data collection with a convenience sample of adults taking diabetes education classes. Half the sample completed audio-taped semi-structured interviews pre, during and posteducation and all completed the MSI posteducation. Qualitative data were analysed using latent content analysis, descriptive statistics were completed. Qualitative analysis revealed content categories similar to previous work with prenatal participants, supporting the enablement framework. Statistical analyses noted congruence with psychometric findings from development of MSI; secondary qualitative analyses revealed congruency between MSI scores and patient perceptions. Mastery is an outcome congruent with the enablement framework for patient education across content areas. Mastery of stress instrument may be a instrument for identification of patients who are coping well with diabetes self-management, as well as those who are not and who require further nursing interventions.

Global Snow-Cover Evolution from Twenty Years of Satellite Passive Microwave Data

USGS Publications Warehouse

Mognard, N.M.; Kouraev, A.V.; Josberger, E.G.

2003-01-01

Starting in 1979 with the SMMR (Scanning Multichannel Microwave Radiometer) instrument onboard the satellite NIMBUS-7 and continuing since 1987 with the SSMI (Special Sensor Microwave Imager) instrument on board the DMSP (Defence Meteorological Satellite Program) series, more then twenty years of satellite passive microwave data are now available. This dataset has been processed to analyse the evolution of the global snow cover. This work is part of the AICSEX project from the 5th Framework Programme of the European Community. The spatio-temporal evolution of the satellite-derived yearly snow maximum extent and the timing of the spring snow melt were estimated and analysed over the Northern Hemisphere. Significant differences between the evolution of the yearly maximum snow extent in Eurasia and in North America were found. A positive correlation between the maximum yearly snow cover extent and the ENSO index was obtained. High interannual spatio-temporal variability characterises the timing of snow melt in the spring. Twenty-year trends in the timing of spring snow melt have been computed and compared with spring air temperature trends for the same period and the same area. In most parts of Eurasia and in the central and western parts of North America the tendency has been for earlier snow melt. In northeastern Canada, a large area of positive trends, where snow melt timing starts later than in the early 1980s, corresponds to a region of positive trends of spring air temperature observed over the same period.

Early meteorological records from Latin-America and the Caribbean during the 18th and 19th centuries

NASA Astrophysics Data System (ADS)

Domínguez-Castro, Fernando; Vaquero, José Manuel; Gallego, María Cruz; Farrona, Ana María Marín; Antuña-Marrero, Juan Carlos; Cevallos, Erika Elizabeth; Herrera, Ricardo García; de La Guía, Cristina; Mejía, Raúl David; Naranjo, José Manuel; Del Rosario Prieto, María; Ramos Guadalupe, Luis Enrique; Seiner, Lizardo; Trigo, Ricardo Machado; Villacís, Marcos

2017-11-01

This paper provides early instrumental data recovered for 20 countries of Latin-America and the Caribbean (Argentina, Bahamas, Belize, Brazil, British Guiana, Chile, Colombia, Costa Rica, Cuba, Ecuador, France (Martinique and Guadalupe), Guatemala, Jamaica, Mexico, Nicaragua, Panama, Peru, Puerto Rico, El Salvador and Suriname) during the 18th and 19th centuries. The main meteorological variables retrieved were air temperature, atmospheric pressure, and precipitation, but other variables, such as humidity, wind direction, and state of the sky were retrieved when possible. In total, more than 300,000 early instrumental data were rescued (96% with daily resolution). Especial effort was made to document all the available metadata in order to allow further post-processing. The compilation is far from being exhaustive, but the dataset will contribute to a better understanding of climate variability in the region, and to enlarging the period of overlap between instrumental data and natural/documentary proxies.

Early meteorological records from Latin-America and the Caribbean during the 18th and 19th centuries.

PubMed

Domínguez-Castro, Fernando; Vaquero, José Manuel; Gallego, María Cruz; Farrona, Ana María Marín; Antuña-Marrero, Juan Carlos; Cevallos, Erika Elizabeth; Herrera, Ricardo García; de la Guía, Cristina; Mejía, Raúl David; Naranjo, José Manuel; Del Rosario Prieto, María; Ramos Guadalupe, Luis Enrique; Seiner, Lizardo; Trigo, Ricardo Machado; Villacís, Marcos

2017-11-14

This paper provides early instrumental data recovered for 20 countries of Latin-America and the Caribbean (Argentina, Bahamas, Belize, Brazil, British Guiana, Chile, Colombia, Costa Rica, Cuba, Ecuador, France (Martinique and Guadalupe), Guatemala, Jamaica, Mexico, Nicaragua, Panama, Peru, Puerto Rico, El Salvador and Suriname) during the 18th and 19th centuries. The main meteorological variables retrieved were air temperature, atmospheric pressure, and precipitation, but other variables, such as humidity, wind direction, and state of the sky were retrieved when possible. In total, more than 300,000 early instrumental data were rescued (96% with daily resolution). Especial effort was made to document all the available metadata in order to allow further post-processing. The compilation is far from being exhaustive, but the dataset will contribute to a better understanding of climate variability in the region, and to enlarging the period of overlap between instrumental data and natural/documentary proxies.

The impact of extracurricular activities participation on youth delinquent behaviors: An instrumental variables approach.

PubMed

Han, Sehee; Lee, Jonathan; Park, Kyung-Gook

2017-07-01

The purpose of this study was to examine the association between extracurricular activities (EA) participation and youth delinquency while tackling an endogeneity problem of EA participation. Using survey data of 12th graders in South Korea (n = 1943), this study employed an instrumental variables approach to address the self-selection problem of EA participation as the data for this study was based on an observational study design. We found a positive association between EA participation and youth delinquency based on conventional regression analysis. By contrast, we found a negative association between EA participation and youth delinquency based on an instrumental variables approach. These results indicate that caution should be exercised when we interpret the effect of EA participation on youth delinquency based on observational study designs. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Analytical techniques and instrumentation: A compilation. [analytical instrumentation, materials performance, and systems analysis

NASA Technical Reports Server (NTRS)

1974-01-01

Technical information is presented covering the areas of: (1) analytical instrumentation useful in the analysis of physical phenomena; (2) analytical techniques used to determine the performance of materials; and (3) systems and component analyses for design and quality control.

An alpha particle instrument with alpha, proton, and X-ray modes for planetary chemical analyses

NASA Technical Reports Server (NTRS)

Economou, T. E.; Turkevich, A. L.

1976-01-01

The interaction of alpha particles with matter is employed in a compact instrument that could provide rather complete in-situ chemical analyses of surfaces and thin atmospheres of extraterrestrial bodies. The instrument is a miniaturized and improved version of the Surveyor lunar instrument. The backscattering of alpha particles and (alpha, p) reactions provide analytical data on the light elements (carbon-iron). An X-ray mode that detects the photons produced by the alpha sources provides sensitivity and resolution for the chemical elements heavier than about silicon. The X-rays are detected by semiconductor detectors having a resolution between 150 and 250 eV at 5.9 keV. Such an instrument can identify and determine with good accuracy 99 percent of the atoms (except hydrogen) in rocks. For many trace elements, the detecting sensitivity is a few ppm. Auxiliary sources could be used to enhance the sensitivities for elements of special interest. The instrument could probably withstand the acceleration involved in semi-hard landings.

Towards more patient centred healthcare: A new Consumer Quality Index instrument to assess patients' experiences with breast care.

PubMed

Damman, Olga C; Hendriks, Michelle; Sixma, Herman J

2009-06-01

To develop a Consumer Quality Index (CQ-index) Breast Care instrument that measures quality of care from the perspective of patients with (suspicion of) breast cancer. To develop a pilot questionnaire, three focus group discussions with breast cancer patients were performed. The questionnaire was sent to 1197 patients. We performed psychometric and descriptive analyses to optimise the new instrument. Focus group discussions revealed nine main themes related to breast care quality. Psychometric analyses resulted in 15 reliable scales. The final instrument consisted of 152 items, of which 118 items regarded patients' experiences. The aspect with the highest need for quality improvement was informing patients about a second opinion. The CQ-index Breast Care (CQI-BC) instrument provides a good starting point for further research on the quality of breast care seen from the perspective of patients. The newly developed instrument can be used by different stakeholders for future quality monitoring.

An Investigation of the Overlap Between the ICECAP-A and Five Preference-Based Health-Related Quality of Life Instruments.

PubMed

Engel, Lidia; Mortimer, Duncan; Bryan, Stirling; Lear, Scott A; Whitehurst, David G T

2017-07-01

The ICEpop CAPability measure for Adults (ICECAP-A) is a measure of capability wellbeing developed for use in economic evaluations. It was designed to overcome perceived limitations associated with existing preference-based instruments, where the explicit focus on health-related aspects of quality of life may result in the failure to capture fully the broader benefits of interventions and treatments that go beyond health. The aim of this study was to investigate the extent to which preference-based health-related quality of life (HRQoL) instruments are able to capture aspects of capability wellbeing, as measured by the ICECAP-A. Using data from the Multi Instrument Comparison project, pairwise exploratory factor analyses were conducted to compare the ICECAP-A with five preference-based HRQoL instruments [15D, Assessment of Quality of Life 8-dimension (AQoL-8D), EQ-5D-5L, Health Utilities Index Mark 3 (HUI-3), and SF-6D]. Data from 6756 individuals were used in the analyses. The ICECAP-A provides information above that garnered from most commonly used preference-based HRQoL instruments. The exception was the AQoL-8D; more common factors were identified between the ICECAP-A and AQoL-8D compared with the other pairwise analyses. Further investigations are needed to explore the extent and potential implications of 'double counting' when applying the ICECAP-A alongside health-related preference-based instruments.

Subjective and psychological well-being of students of a University of the Third Age: Benefits of continuing education for psychological adjustment in the elderly

PubMed Central

Ordonez, Tiago Nascimento; Lima-Silva, Thaís Bento; Cachioni, Meire

2011-01-01

Objectives The present study sought to characterize the degree of general satisfaction with life and degree of satisfaction on four domains: health, physical capacity, mental capacity and social involvement, and to determine the characteristics of self-reports of individuals enrolled on the program in relation to their psychological well-being focusing on the dimensions: autonomy, personal growth, control, positive relationships with others, purpose, personal acceptance and generativity, and to analyse the effect of time studying on level of well-being. Method A total of 140 elderly students of a University for the Third Age took part in the study. The Global Satisfaction With Life Scale and the Self Development Scale (with six psychological well-being subscales) were applied. Continuous variables for the two groups were compared using the Mann-Whitney test. Spearman’s correlation coefficient was used to analyze the relationship among numeric variables. Internal consistency of the instrument scales was analysed by calculating Cronbach’s alpha coefficient. Results Results showed that students who had attended the University of the Third Age for six months or longer had a higher level of satisfaction with life and greater psychological adjustment compared with new entrants to the same institution. Conclusion The study results confirmed the positive effects of continuing education on the well-being of elderly and its contribution to successful aging. PMID:29213747

A comparison of four different blood gas analysers.

PubMed

Kofstad, J

1981-06-01

Four automatic blood gas analysers from four different manufactures were evaluated and compared. The measurements were performed on blood representing respiratory acidosis and hypoxemia, normal conditions, and respiratory alkalosis and hyperoxemia. On each level nine complete runs were carried out, each run consisting of six replicates of each parameter (pH, Pco2 and Po2) on each instrument (six rounds). Only the directly measured parameters (pH, Pco2, Po2) were compared. The main conclusion is that the four instruments can be used alternatively, and that the differences between the values measured by the four instruments are of little clinical significance.

Importance of Intrinsic and Instrumental Value of Education in Pakistan

ERIC Educational Resources Information Center

Kumar, Mahendar

2017-01-01

Normally, effectiveness of any object or thing is judged by two values; intrinsic and instrumental. To compare intrinsic value of education with instrumental value, this study has used the following variables: getting knowledge for its own sake, getting knowledge for social status, getting knowledge for job or business endeavor and getting…

The effect of aircraft control forces on pilot performance during instrument landings in a flight simulator.

PubMed

Hewson, D J; McNair, P J; Marshall, R N

2001-07-01

Pilots may have difficulty controlling aircraft at both high and low force levels due to larger variability in force production at these force levels. The aim of this study was to measure the force variability and landing performance of pilots during an instrument landing in a flight simulator. There were 12 pilots who were tested while performing 5 instrument landings in a flight simulator, each of which required different control force inputs. Pilots can produce the least force when pushing the control column to the right, therefore the force levels for the landings were set relative to each pilot's maximum aileron-right force. The force levels for the landings were 90%, 60%, and 30% of maximal aileron-right force, normal force, and 25% of normal force. Variables recorded included electromyographic activity (EMG), aircraft control forces, aircraft attitude, perceived exertion and deviation from glide slope and heading. Multivariate analysis of variance was used to test for differences between landings. Pilots were least accurate in landing performance during the landing at 90% of maximal force (p < 0.05). There was also a trend toward decreased landing performance during the landing at 25% of normal force. Pilots were more variable in force production during the landings at 60% and 90% of maximal force (p < 0.05). Pilots are less accurate at performing instrument landings when control forces are high due to the increased variability of force production. The increase in variability at high force levels is most likely associated with motor unit recruitment, rather than rate coding. Aircraft designers need to consider the reduction in pilot performance at high force levels, as well as pilot strength limits when specifying new standards.

Spectrophotometers for plutonium monitoring in HB-line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lascola, R. J.; O'Rourke, P. E.; Kyser, E. A.

2016-02-12

This report describes the equipment, control software, calibrations for total plutonium and plutonium oxidation state, and qualification studies for the instrument. It also provides a detailed description of the uncertainty analysis, which includes source terms associated with plutonium calibration standards, instrument drift, and inter-instrument variability. Also included are work instructions for instrument, flow cell, and optical fiber setup, work instructions for routine maintenance, and drawings and schematic diagrams.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garimella, Sarvesh; Rothenberg, Daniel A.; Wolf, Martin J.

This study investigates the measurement of ice nucleating particle (INP) concentrations and sizing of crystals using continuous flow diffusion chambers (CFDCs). CFDCs have been deployed for decades to measure the formation of INPs under controlled humidity and temperature conditions in laboratory studies and by ambient aerosol populations. These measurements have, in turn, been used to construct parameterizations for use in models by relating the formation of ice crystals to state variables such as temperature and humidity as well as aerosol particle properties such as composition and number. We show here that assumptions of ideal instrument behavior are not supported by measurements mademore » with a commercially available CFDC, the SPectrometer for Ice Nucleation (SPIN), and the instrument on which it is based, the Zurich Ice Nucleation Chamber (ZINC). Non-ideal instrument behavior, which is likely inherent to varying degrees in all CFDCs, is caused by exposure of particles to different humidities and/or temperatures than predicated from instrument theory of operation. This can result in a systematic, and variable, underestimation of reported INP concentrations. Here we find here variable correction factors from 1.5 to 9.5, consistent with previous literature values. We use a machine learning approach to show that non-ideality is most likely due to small-scale flow features where the aerosols are combined with sheath flows. Machine learning is also used to minimize the uncertainty in measured INP concentrations. Finally, we suggest that detailed measurement, on an instrument-by-instrument basis, be performed to characterize this uncertainty.« less

Uncertainty in counting ice nucleating particles with continuous flow diffusion chambers

NASA Astrophysics Data System (ADS)

Garimella, Sarvesh; Rothenberg, Daniel A.; Wolf, Martin J.; David, Robert O.; Kanji, Zamin A.; Wang, Chien; Rösch, Michael; Cziczo, Daniel J.

2017-09-01

This study investigates the measurement of ice nucleating particle (INP) concentrations and sizing of crystals using continuous flow diffusion chambers (CFDCs). CFDCs have been deployed for decades to measure the formation of INPs under controlled humidity and temperature conditions in laboratory studies and by ambient aerosol populations. These measurements have, in turn, been used to construct parameterizations for use in models by relating the formation of ice crystals to state variables such as temperature and humidity as well as aerosol particle properties such as composition and number. We show here that assumptions of ideal instrument behavior are not supported by measurements made with a commercially available CFDC, the SPectrometer for Ice Nucleation (SPIN), and the instrument on which it is based, the Zurich Ice Nucleation Chamber (ZINC). Non-ideal instrument behavior, which is likely inherent to varying degrees in all CFDCs, is caused by exposure of particles to different humidities and/or temperatures than predicated from instrument theory of operation. This can result in a systematic, and variable, underestimation of reported INP concentrations. We find here variable correction factors from 1.5 to 9.5, consistent with previous literature values. We use a machine learning approach to show that non-ideality is most likely due to small-scale flow features where the aerosols are combined with sheath flows. Machine learning is also used to minimize the uncertainty in measured INP concentrations. We suggest that detailed measurement, on an instrument-by-instrument basis, be performed to characterize this uncertainty.

High resolution geochemical proxy record of the last 600yr in a speleothem from the northwest Iberian Peninsula

NASA Astrophysics Data System (ADS)

Iglesias González, Miguel; Pisonero, Jorge; Cheng, Hai; Edwards, R. Lawrence; Stoll, Heather

2017-04-01

In meteorology and climatology, the instrumental period is the period where we have measured directly by instrumentation, different meteorological data along the surface which allow us to determinate the evolution of the climate during the last 150 years over the world. At the beginning, the density of this data were very low, so we have to wait until the last 75-100 years to have a good network in most of the parts of the surface. This time period is very small if we want to analyze the relationship between geochemical and instrumental variability in any speleothem. So a very high resolution data is needed to determinate the connection between both of them in the instrumental period, to try to determinate de evolution of climate in the last 600 years. Here we present a high resolution speleothem record from a cave located in the middle of the Cantabrian Mountains without any anthropologic influence and with no CO2 seasonal variability. This 600yr stalagmite, dated with U/Th method with a growth rate from 100 to 200 micrometers/yr calculated with Bchron model, provide us accurate information of the climate conditions near the cave. Trace elements are analyzed at 8 micrometers intervals by Laser Ablation ICP-MS which resolves even monthly resolution during the last 600 years with special attention with Sr, Mg, Al and Si. This data, without seasonal variability and with the presence of a river inside the cave, give us very valuable information about the extreme flood events inside the cave during the whole period, which is related with the precipitations and the snow fusion events outside the cave. We identify more extremely flood events during the Little Ice Age than in the last 100yr. As well, we have trace elements data with spatial resolution of 0.2mm analyzed with ICP-AES which allow us to compare the geochemical variability with both technics. We also analyze stable isotope d13C and d18O with a spatial resolution of 0.2mm, so we are able to identify variations and all possible correlations between them, trace elements and instrumental records from the different weather stations located near the cave. We use instrumental data, and the statistical correlation between our proxy and them, to calibrate and analyze the variability along the 600yr which provide us a lot of information about the climate variability. In spite of the significate global warming during the last 25 years, we have less variability during this period than along the transition between the Medieval Warm Period and the Little Ice Age. We also analyze this variability along the 600 years with wavelet analysis, with special attention in the instrumental period. With this mathematical method, we can identify several cycles both in trace elements and stable isotopes at special scales compatible with the decadal and multidecadal variability with a value similar to very important climate index like AMO.

Long-term infrared monitoring of stellar sources from earth orbit

NASA Technical Reports Server (NTRS)

Maran, S. P.; Heinsheimer, T. F.; Stocker, T. L.; Anand, S. P. S.; Chapman, R. D.; Hobbs, R. W.; Michalitsanos, A. G.; Wright, F. H.; Kipp, S. L.

1976-01-01

A program is discussed which involved monitoring the photometric activity of 18 bright variable IR stars at 2.7 microns with satellite- and rocket-borne instrumentation in the period from 1971 to 1975. The stellar sample includes 3 Lb variables, 8 semiregular variables, 5 Mira-type variables, and 2 previously unknown and unclassified IR variables. Detailed light curves of many of these stars were determined for intervals of 3 yr or more; spectra from 2.7 to 20 microns were constructed for nine of them using data obtained entirely with instruments above the atmosphere. Photometric IR light curves and other data are presented for SW Virginis, R Aquilae, S Scuti, IRC 00265, RT Hydrae, S Orionis, S Canis Minoris, Omicron Ceti, and R Leonis. Several hypotheses concerning the interpretation of the IR data are examined.

A laser desorption ionization/matrix-assisted laser desorption ionization target system applicable for three distinct types of instruments (LinTOF/curved field RTOF, LinTOF/RTOF and QqRTOF) with different performance characteristics from three vendors.

PubMed

Rados, Edita; Pittenauer, Ernst; Frank, Johannes; Varmuza, Kurt; Allmaier, Günter

2018-04-30

We have developed a target system which enables the use of only one target (i.e. target preparation set) for three different laser desorption ionization (LDI)/matrix-assisted laser desorption ionization (MALDI) mass spectrometric instruments. The focus was on analysing small biomolecules with LDI for future use of the system for the study of meteorite samples (carbonaceous chondrites) using devices with different mass spectrometric performance characteristics. Three compounds were selected due to their potential presence in meteoritic chondrites: tryptophan, 2-deoxy-d-ribose and triphenylene. They were prepared (with and without MALDI matrix, i.e. MALDI and LDI) and analysed with three different mass spectrometers (LinTOF/curved field RTOF, LinTOF/RTOF and QqRTOF). The ion sources of two of the instruments were run at high vacuum, and one at intermediate pressure. Two devices used a laser wavelength of 355 nm and one a wavelength of 337 nm. The developed target system operated smoothly with all devices. Tryptophan, 2-deoxy-d-ribose and triphenylene showed similar desorption/ionization behaviour for all instruments using the LDI mode. Interestingly, protonated tryptophan could be observed only with the LinTOF/curved field RTOF device in LDI and MALDI mode, while sodiated molecules were observed with all three instruments (in both ion modes). Deprotonated tryptophan was almost completely obscured by matrix ions in the MALDI mode whereas LDI yielded abundant deprotonated molecules. The presented target system allowed successful analyses of the three compounds using instruments from different vendors with only one preparation showing different analyser performance characteristics. The elemental composition with the QqRTOF analyser and the high-energy 20 keV collision-induced dissociation fragmentation will be important in identifying unknown compounds in chondrites. © 2018 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd.

Relative validation of Block Kids Food Screener for dietary assessment in children and adolescents.

PubMed

Hunsberger, Monica; O'Malley, Jean; Block, Torin; Norris, Jean C

2015-04-01

Food frequency questionnaires (FFQs) are less time consuming and inexpensive instruments for collecting dietary intake when compared with 24-h dietary recalls or double-labelled water; however, the validation of FFQ is important as incorrect information may lead to biased conclusions about associations. Therefore, the relative validity of the Block Kids Food Screener (BKFS) developed for use with children was examined in a convenience sample of 99 youth recruited from the Portland, OR metropolitan area. Three 24-h dietary recalls served as the reference. The relative validity was analysed after natural log transformation of all variables except glycaemic index prior to correlation analysis. Daily cup equivalent totals from the BKFS and 'servings' from 24-h recalls were used to compute average daily intake of fruits, vegetables, potatoes, whole grains, legumes, meat/fish/poultry and dairy. Protein grams (g), total kcalories, glycaemic index (glucose reference), glycaemic load (glucose reference), total saturated fat (g) and added sugar (g) were also calculated by each instrument. The correlation between data obtained from the two instruments was corrected for the within-subject variation in food intake reported by the 24-h recalls using standard nutritional assessment methodology. The de-attenuated correlations in nutritional intake between the two dietary assessment instruments ranged from 0.526 for vegetables, to 0.878 for potatoes. The 24-h recall estimated higher levels of saturated fat and added sugar consumption, higher glycaemic loads and glycaemic indices; the de-attenuatted correlations of these measures ranged from 0.478 to 0.768. Assessment of Bland-Altman plots indicated no systematic difference between the two instruments for vegetable, dairy and meat/fish/poultry fat consumption. BKFS is a useful dietary assessment instrument for the nutrients and food groups it was designed to assess in children age 10-17 years. © 2012 Blackwell Publishing Ltd.

Cryopyrin-associated periodic syndromes: development of a patient-reported outcomes instrument to assess the pattern and severity of clinical disease activity.

PubMed

Hoffman, Hal M; Wolfe, Frederick; Belomestnov, Pavel; Mellis, Scott J

2008-09-01

Development of an instrument for characterization of symptom patterns and severity in patients with cryopyrin-associated periodic syndromes (CAPS). Two generations of daily health assessment forms (DHAFs) were evaluated in this study. The first-generation DHAF queried 11 symptoms. Analyses of results obtained with that instrument identified five symptoms included in a revised second-generation DHAF that was tested for internal consistency and test-retest reliability. This DHAF was also assessed during the initial portion of a phase 3 clinical study of CAPS treatment. Forty-eight CAPS patients provided data for the first-generation DHAFs. Five symptoms (rash, fever, joint pain, eye redness/pain, and fatigue) were included in the revised second-generation DHAF. Symptom severity was highly variable during all study phases with as many as 89% of patients reporting at least one symptom flare, and percentages of days with flares reaching 58% during evaluation of the second-generation instrument. Mean composite key symptom scores (KSSs) computed during evaluation of the second-generation DHAF correlated well with Physician's Global Assessment of Disease Activity (r=0.91, p<0.0001) and patient reports of limitations of daily activities (r=0.68, p<0.0001). Test-retest reliability and Cronbach's alpha's were high (0.93 and 0.94, respectively) for the second-generation DHAF. Further evaluation of this DHAF during a baseline period and placebo treatment in a phase 3 clinical study of CAPS patients indicated strong correlations between baseline KSS and Physician's Global Assessment of Disease Activity. Cronbach's alpha's at baseline and test-retest reliability were also high. Potentially important study limitations include small sample size, the lack of a standard tool for CAPS symptom assessment against which to validate the DHAF, and no assessment of the instrument's responsivity to CAPS therapy. The DHAF is a new instrument that may be useful for capturing symptom patterns and severity in CAPS patients and monitoring responses to therapies for these conditions.

On the signatures of flare-induced global waves in the Sun: GOLF and VIRGO observations

NASA Astrophysics Data System (ADS)

Kumar, Brajesh; Mathur, Savita; García, Rafael A.; Jiménez, Antonio

2017-11-01

Recently, several efforts have been made to identify the seismic signatures of flares and magnetic activity in the Sun and Sun-like stars. In this work, we have analysed the disc-integrated velocity and intensity observations of the Sun obtained from the Global Oscillations at Low Frequencies (GOLF) and Variability of solar IRradiance and Gravity Oscillations/Sun photometers (VIRGO/SPM) instruments, respectively, on board the Solar and Heliospheric Observatory space mission covering several successive flare events, for the period from 2011 February 11 to 2011 February 17, of which 2011 February 11 remained a relatively quiet day and served as a `null test' for the investigation. Application of the spectral analysis to these disc-integrated Sun-as-a-star velocity and intensity signals indicates that there is enhanced power of the global modes of oscillations in the Sun during the flares, as compared to the quiet day. The GOLF instrument obtains velocity observations using the Na I D lines which are formed in the upper solar photosphere, while the intensity data used in our analysis are obtained by VIRGO/SPM instrument at 862 nm, which is formed within the solar photosphere. Despite the fact that the two instruments sample different layers of the solar atmosphere using two different parameters (velocity versus intensity), we have found that both these observations show the signatures of flare-induced global waves in the Sun. These results could suffice in identifying the asteroseismic signatures of stellar flares and magnetic activity in the Sun-like stars.

Psychosocial Assessment of Self-Harm Patients and Risk of Repeat Presentation: An Instrumental Variable Analysis Using Time of Hospital Presentation.

PubMed

Carroll, Robert; Metcalfe, Chris; Steeg, Sarah; Davies, Neil M; Cooper, Jayne; Kapur, Nav; Gunnell, David

2016-01-01

Clinical guidelines have recommended psychosocial assessment of self-harm patients for years, yet estimates of its impact on the risk of repeat self-harm vary. Assessing the association of psychosocial assessment with risk of repeat self-harm is challenging due to the effects of confounding by indication. We analysed data from a cohort study of 15,113 patients presenting to the emergency departments of three UK hospitals to investigate the association of psychosocial assessment with risk of repeat hospital presentation for self-harm. Time of day of hospital presentation was used as an instrument for psychosocial assessment, attempting to control for confounding by indication. Conventional regression analysis suggested psychosocial assessment was not associated with risk of repeat self-harm within 12 months (Risk Difference (RD) 0.00 95% confidence interval (95%CI) -0.01 to 0.02). In contrast, IV analysis suggested risk of repeat self-harm was reduced by 18% (RD -0.18, 95%CI -0.32 to -0.03) in those patients receiving a psychosocial assessment. However, the instrument of time of day did not remove all potential effects of confounding by indication, suggesting the IV effect estimate may be biased. We found that psychosocial assessments reduce risk of repeat self-harm. This is in-line with other non-randomised studies based on populations in which allocation to assessment was less subject to confounding by indication. However, as our instrument did not fully balance important confounders across time of day, the IV effect estimate should be interpreted with caution.

"Fibromyalgia and quality of life: mapping the revised fibromyalgia impact questionnaire to the preference-based instruments".

PubMed

Collado-Mateo, Daniel; Chen, Gang; Garcia-Gordillo, Miguel A; Iezzi, Angelo; Adsuar, José C; Olivares, Pedro R; Gusi, Narcis

2017-05-30

The revised version of the Fibromyalgia Impact Questionnaire (FIQR) is one of the most widely used specific questionnaires in FM studies. However, this questionnaire does not allow calculation of QALYs as it is not a preference-based measure. The aim of this study was to develop mapping algorithm which enable FIQR scores to be transformed into utility scores that can be used in the cost utility analyses. A cross-sectional survey was conducted. One hundred and 92 Spanish women with Fibromyalgia were asked to complete four general quality of life questionnaires, i.e. EQ-5D-5 L, 15D, AQoL-8D and SF-12, and one specific disease instrument, the FIQR. A direct mapping approach was adopted to derive mapping algorithms between the FIQR and each of the four multi-attribute utility (MAU) instruments. Health state utility was treated as the dependent variable in the regression analysis, whilst the FIQR score and age were predictors. The mean utility scores ranged from 0.47 (AQoL-8D) to 0.69 (15D). All correlations between the FIQR total score and MAU instruments utility scores were highly significant (p < 0.0001) with magnitudes larger than 0.5. Although very slight differences in the mean absolute error were found between ordinary least squares (OLS) estimator and generalized linear model (GLM), models based on GLM were better for EQ-5D-5 L, AQoL-8D and 15D. Mapping algorithms developed in this study enable the estimation of utility values from scores in a fibromyalgia specific questionnaire.

Generic patient-reported outcomes in child health research: a review of conceptual content using World Health Organization definitions.

PubMed

Fayed, Nora; de Camargo, Olaf Kraus; Kerr, Elizabeth; Rosenbaum, Peter; Dubey, Ankita; Bostan, Cristina; Faulhaber, Markus; Raina, Parminder; Cieza, Alarcos

2012-12-01

Our aims were to (1) describe the conceptual basis of popular generic instruments according to World Health Organization (WHO) definitions of functioning, disability, and health (FDH), and quality of life (QOL) with health-related quality of life (HRQOL) as a subcomponent of QOL; (2) map the instruments to the International Classification of Functioning, Disability and Health (ICF); and (3) provide information on how the analyzed instruments were used in the literature. This should enable users to make valid choices about which instruments have the desired content for a specific context or purpose. Child health-based literature over a 5-year period was reviewed to find research employing health status and QOL/HRQOL instruments. WHO definitions of FDH and QOL were applied to each item of the 15 most used instruments to differentiate measures of FDH and QOL/HRQOL. The ICF was used to describe the health and health-related content (if any) in those instruments. Additional aspects of instrument use were extracted from these articles. Many instruments that were used to measure QOL/HRQOL did not reflect WHO definitions of QOL. The ICF domains within instruments were highly variable with respect to whether body functions, activities and participation, or environment were emphasized. There is inconsistency among researchers about how to measure HRQOL and QOL. Moreover, when an ICF content analysis is applied, there is variability among instruments in the health components included and emphasized. Reviewing content is important for matching instruments to their intended purpose. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

Age-Related Changes in Bimanual Instrument Playing with Rhythmic Cueing

PubMed Central

Kim, Soo Ji; Cho, Sung-Rae; Yoo, Ga Eul

2017-01-01

Deficits in bimanual coordination of older adults have been demonstrated to significantly limit their functioning in daily life. As a bimanual sensorimotor task, instrument playing has great potential for motor and cognitive training in advanced age. While the process of matching a person’s repetitive movements to auditory rhythmic cueing during instrument playing was documented to involve motor and attentional control, investigation into whether the level of cognitive functioning influences the ability to rhythmically coordinate movement to an external beat in older populations is relatively limited. Therefore, the current study aimed to examine how timing accuracy during bimanual instrument playing with rhythmic cueing differed depending on the degree of participants’ cognitive aging. Twenty one young adults, 20 healthy older adults, and 17 older adults with mild dementia participated in this study. Each participant tapped an electronic drum in time to the rhythmic cueing provided using both hands simultaneously and in alternation. During bimanual instrument playing with rhythmic cueing, mean and variability of synchronization errors were measured and compared across the groups and the tempo of cueing during each type of tapping task. Correlations of such timing parameters with cognitive measures were also analyzed. The results showed that the group factor resulted in significant differences in the synchronization errors-related parameters. During bimanual tapping tasks, cognitive decline resulted in differences in synchronization errors between younger adults and older adults with mild dimentia. Also, in terms of variability of synchronization errors, younger adults showed significant differences in maintaining timing performance from older adults with and without mild dementia, which may be attributed to decreased processing time for bimanual coordination due to aging. Significant correlations were observed between variability of synchronization errors and performance of cognitive tasks involving executive control and cognitive flexibility when asked for bimanual coordination in response to external timing cues at adjusted tempi. Also, significant correlations with cognitive measures were more prevalent in variability of synchronization errors during alternative tapping compared to simultaneous tapping. The current study supports that bimanual tapping may be predictive of cognitive processing of older adults. Also, tempo and type of movement required for instrument playing both involve cognitive and motor loads at different levels, and such variables could be important factors for determining the complexity of the task and the involved task requirements for interventions using instrument playing. PMID:29085309

Validation of the Work-Life Balance Culture Scale (WLBCS).

PubMed

Nitzsche, Anika; Jung, Julia; Kowalski, Christoph; Pfaff, Holger

2014-01-01

The purpose of this paper is to describe the theoretical development and initial validation of the newly developed Work-Life Balance Culture Scale (WLBCS), an instrument for measuring an organizational culture that promotes the work-life balance of employees. In Study 1 (N=498), the scale was developed and its factorial validity tested through exploratory factor analyses. In Study 2 (N=513), confirmatory factor analysis (CFA) was performed to examine model fit and retest the dimensional structure of the instrument. To assess construct validity, a priori hypotheses were formulated and subsequently tested using correlation analyses. Exploratory and confirmatory factor analyses revealed a one-factor model. Results of the bivariate correlation analyses may be interpreted as preliminary evidence of the scale's construct validity. The five-item WLBCS is a new and efficient instrument with good overall quality. Its conciseness makes it particularly suitable for use in employee surveys to gain initial insight into a company's perceived work-life balance culture.

Development of a computer-adaptive physical function instrument for Social Security Administration disability determination.

PubMed

Ni, Pengsheng; McDonough, Christine M; Jette, Alan M; Bogusz, Kara; Marfeo, Elizabeth E; Rasch, Elizabeth K; Brandt, Diane E; Meterko, Mark; Haley, Stephen M; Chan, Leighton

2013-09-01

To develop and test an instrument to assess physical function for Social Security Administration (SSA) disability programs, the SSA-Physical Function (SSA-PF) instrument. Item response theory (IRT) analyses were used to (1) create a calibrated item bank for each of the factors identified in prior factor analyses, (2) assess the fit of the items within each scale, (3) develop separate computer-adaptive testing (CAT) instruments for each scale, and (4) conduct initial psychometric testing. Cross-sectional data collection; IRT analyses; CAT simulation. Telephone and Internet survey. Two samples: SSA claimants (n=1017) and adults from the U.S. general population (n=999). None. Model fit statistics, correlation, and reliability coefficients. IRT analyses resulted in 5 unidimensional SSA-PF scales: Changing & Maintaining Body Position, Whole Body Mobility, Upper Body Function, Upper Extremity Fine Motor, and Wheelchair Mobility for a total of 102 items. High CAT accuracy was demonstrated by strong correlations between simulated CAT scores and those from the full item banks. On comparing the simulated CATs with the full item banks, very little loss of reliability or precision was noted, except at the lower and upper ranges of each scale. No difference in response patterns by age or sex was noted. The distributions of claimant scores were shifted to the lower end of each scale compared with those of a sample of U.S. adults. The SSA-PF instrument contributes important new methodology for measuring the physical function of adults applying to the SSA disability programs. Initial evaluation revealed that the SSA-PF instrument achieved considerable breadth of coverage in each content domain and demonstrated noteworthy psychometric properties. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Intraindividual Variability in Executive Functions but Not Speed of Processing or Conflict Resolution Predicts Performance Differences in Gait Speed in Older Adults

PubMed Central

Mahoney, Jeannette; Verghese, Joe

2014-01-01

Background. The relationship between executive functions (EF) and gait speed is well established. However, with the exception of dual tasking, the key components of EF that predict differences in gait performance have not been determined. Therefore, the current study was designed to determine whether processing speed, conflict resolution, and intraindividual variability in EF predicted variance in gait performance in single- and dual-task conditions. Methods. Participants were 234 nondemented older adults (mean age 76.48 years; 55% women) enrolled in a community-based cohort study. Gait speed was assessed using an instrumented walkway during single- and dual-task conditions. The flanker task was used to assess EF. Results. Results from the linear mixed effects model showed that (a) dual-task interference caused a significant dual-task cost in gait speed (estimate = 35.99; 95% CI = 33.19–38.80) and (b) of the cognitive predictors, only intraindividual variability was associated with gait speed (estimate = −.606; 95% CI = −1.11 to −.10). In unadjusted analyses, the three EF measures were related to gait speed in single- and dual-task conditions. However, in fully adjusted linear regression analysis, only intraindividual variability predicted performance differences in gait speed during dual tasking (B = −.901; 95% CI = −1.557 to −.245). Conclusion. Among the three EF measures assessed, intraindividual variability but not speed of processing or conflict resolution predicted performance differences in gait speed. PMID:24285744

Laboratory comparison of the mechanical properties of TRUShape with several nickel-titanium rotary instruments.

PubMed

Elnaghy, A M; Elsaka, S E

2017-08-01

To assess and compare the mechanical properties of TRUShape (TRS) with several nickel-titanium rotary instruments. Cyclic fatigue, torsional resistance, flexibility and surface microhardness of TRS (size 25, 0.06v taper), ProTaper Next X2 (PTN X2, size 25, 0.06 taper), ProTaper Gold (PTG F2; size 25, 0.08 taper) and ProTaper Universal (PTU F2; size 25, 0.08 taper) instruments were evaluated. The topographical structures of the fracture surfaces of instruments were assessed using a scanning electron microscope. The cyclic fatigue resistance, torsional resistance and microhardness data were analysed using one-way analysis of variance (anova) and Tukey's post hoc tests. The fragment length and bending resistance data were analysed statistically with the Kruskal-Wallis H-test and Mann-Whitney U-tests. The statistical significance level was set at P < 0.05. PTN and PTG instruments revealed significantly higher resistance to cyclic fatigue than TRS and PTU instruments (P < 0.001). PTN instruments revealed significantly higher torsional resistance compared with the other instruments (P < 0.001). PTG instrument had significantly higher flexibility than the other tested brands (P < 0.05). However, for microhardness, the PTU had significantly higher surface microhardness values compared with other tested brands (P < 0.05). TRS instruments had lower resistance to cyclic fatigue and lower flexibility compared with PTG and PTN instruments. TRS, PTG and PTU instruments had lower resistance to torsional stress than PTN instruments. TRS and PTG instruments had comparable surface microhardness. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Surface Meteorological Station - Astoria, OR (AST) - Raw Data

DOE Data Explorer

Gottas, Daniel

2017-10-23

A variety of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Bonneville - Raw Data

DOE Data Explorer

McCaffrey, Katherine

2017-10-23

A diversity of instruments are used to measure various quantities related to meteorology and precipitation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Condon - Reviewed Data

DOE Data Explorer

McCaffrey, Katherine

2017-10-23

A diversity of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Troutdale - Reviewed Data

DOE Data Explorer

Gottas, Daniel

2017-12-11

A diversity of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Prineville - Raw Data

DOE Data Explorer

McCaffrey, Katherine

2017-10-23

A diversity of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Troutdale - Raw Data

DOE Data Explorer

Gottas, Daniel

2017-12-11

A diversity of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Prineville - Reviewed Data

DOE Data Explorer

McCaffrey, Katherine

2017-10-23

A diversity of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Bonneville - Reviewed Data

DOE Data Explorer

McCaffrey, Katherine

2017-10-23

A diversity of instruments are used to measure various quantities related to meteorology and precipitation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - North Bend, OR (OTH) - Raw Data

DOE Data Explorer

Gottas, Daniel

2017-10-23

A variety of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Condon - Raw Data

DOE Data Explorer

McCaffrey, Katherine

2017-10-23

A diversity of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Percentage Energy from Fat Screener: Overview

Cancer.gov

A short assessment instrument to estimate an individual's usual intake of percentage energy from fat. The foods asked about on the instrument were selected because they were the most important predictors of variability in percentage energy.

Surface Meteorological Station - Forks, WA (FKS) - Raw Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gottas, Daniel

A variety of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - Forks, WA (FKS) - Reviewed Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gottas, Daniel

A variety of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Instrumental and Documentational Approaches: From Technology Use to Documentation Systems in University Mathematics Education

ERIC Educational Resources Information Center

Gueudet, Ghislaine; Buteau, Chantal; Mesa, Vilma; Misfeldt, Morten

2014-01-01

In this article we present an "instrumental approach" in mathematics education, which focuses on the interactions between students, teachers, and "artefacts." This approach analyses "mediations" attached to the use of a given artefact and "instruments" developed by the subjects from this artefact along…

Interpersonal Interactions in Instrumental Lessons: Teacher/Student Verbal and Non-Verbal Behaviours

ERIC Educational Resources Information Center

Zhukov, Katie

2013-01-01

This study examined verbal and non-verbal teacher/student interpersonal interactions in higher education instrumental music lessons. Twenty-four lessons were videotaped and teacher/student behaviours were analysed using a researcher-designed instrument. The findings indicate predominance of student and teacher joke among the verbal behaviours with…

Development of an instrument to understand the child protective services decision-making process, with a focus on placement decisions.

PubMed

Dettlaff, Alan J; Christopher Graham, J; Holzman, Jesse; Baumann, Donald J; Fluke, John D

2015-11-01

When children come to the attention of the child welfare system, they become involved in a decision-making process in which decisions are made that have a significant effect on their future and well-being. The decision to remove children from their families is particularly complex; yet surprisingly little is understood about this decision-making process. This paper presents the results of a study to develop an instrument to explore, at the caseworker level, the context of the removal decision, with the objective of understanding the influence of the individual and organizational factors on this decision, drawing from the Decision Making Ecology as the underlying rationale for obtaining the measures. The instrument was based on the development of decision-making scales used in prior decision-making studies and administered to child protection caseworkers in several states. Analyses included reliability analyses, principal components analyses, and inter-correlations among the resulting scales. For one scale regarding removal decisions, a principal components analysis resulted in the extraction of two components, jointly identified as caseworkers' decision-making orientation, described as (1) an internal reference to decision-making and (2) an external reference to decision-making. Reliability analyses demonstrated acceptable to high internal consistency for 9 of the 11 scales. Full details of the reliability analyses, principal components analyses, and inter-correlations among the seven scales are discussed, along with implications for practice and the utility of this instrument to support the understanding of decision-making in child welfare. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genetic instrumental variable regression: Explaining socioeconomic and health outcomes in nonexperimental data

PubMed Central

DiPrete, Thomas A.; Burik, Casper A. P.; Koellinger, Philipp D.

2018-01-01

Identifying causal effects in nonexperimental data is an enduring challenge. One proposed solution that recently gained popularity is the idea to use genes as instrumental variables [i.e., Mendelian randomization (MR)]. However, this approach is problematic because many variables of interest are genetically correlated, which implies the possibility that many genes could affect both the exposure and the outcome directly or via unobserved confounding factors. Thus, pleiotropic effects of genes are themselves a source of bias in nonexperimental data that would also undermine the ability of MR to correct for endogeneity bias from nongenetic sources. Here, we propose an alternative approach, genetic instrumental variable (GIV) regression, that provides estimates for the effect of an exposure on an outcome in the presence of pleiotropy. As a valuable byproduct, GIV regression also provides accurate estimates of the chip heritability of the outcome variable. GIV regression uses polygenic scores (PGSs) for the outcome of interest which can be constructed from genome-wide association study (GWAS) results. By splitting the GWAS sample for the outcome into nonoverlapping subsamples, we obtain multiple indicators of the outcome PGSs that can be used as instruments for each other and, in combination with other methods such as sibling fixed effects, can address endogeneity bias from both pleiotropy and the environment. In two empirical applications, we demonstrate that our approach produces reasonable estimates of the chip heritability of educational attainment (EA) and show that standard regression and MR provide upwardly biased estimates of the effect of body height on EA. PMID:29686100

Genetic instrumental variable regression: Explaining socioeconomic and health outcomes in nonexperimental data.

PubMed

DiPrete, Thomas A; Burik, Casper A P; Koellinger, Philipp D

2018-05-29

Identifying causal effects in nonexperimental data is an enduring challenge. One proposed solution that recently gained popularity is the idea to use genes as instrumental variables [i.e., Mendelian randomization (MR)]. However, this approach is problematic because many variables of interest are genetically correlated, which implies the possibility that many genes could affect both the exposure and the outcome directly or via unobserved confounding factors. Thus, pleiotropic effects of genes are themselves a source of bias in nonexperimental data that would also undermine the ability of MR to correct for endogeneity bias from nongenetic sources. Here, we propose an alternative approach, genetic instrumental variable (GIV) regression, that provides estimates for the effect of an exposure on an outcome in the presence of pleiotropy. As a valuable byproduct, GIV regression also provides accurate estimates of the chip heritability of the outcome variable. GIV regression uses polygenic scores (PGSs) for the outcome of interest which can be constructed from genome-wide association study (GWAS) results. By splitting the GWAS sample for the outcome into nonoverlapping subsamples, we obtain multiple indicators of the outcome PGSs that can be used as instruments for each other and, in combination with other methods such as sibling fixed effects, can address endogeneity bias from both pleiotropy and the environment. In two empirical applications, we demonstrate that our approach produces reasonable estimates of the chip heritability of educational attainment (EA) and show that standard regression and MR provide upwardly biased estimates of the effect of body height on EA. Copyright © 2018 the Author(s). Published by PNAS.

An instrument to measure job satisfaction of nursing home administrators

PubMed Central

Castle, Nicholas G

2006-01-01

Background The psychometric properties of the nursing home administrator job satisfaction questionnaire (NHA-JSQ) are presented, and the steps used to develop this instrument. Methods The NHA-JSQ subscales were developed from pilot survey activities with 93 administrators, content analysis, and a research panel. The resulting survey was sent to 1,000 nursing home administrators. Factor analyses were used to determine the psychometric properties of the instrument. Results Of the 1,000 surveys mailed, 721 usable surveys were returned (72 percent response rate). The factor analyses show that the items were representative of six underlying factors (i.e., coworkers, work demands, work content, work load, work skills, and rewards). Conclusion The NHA-JSQ represents a short, psychometrically sound job satisfaction instrument for use in nursing homes. PMID:17029644

The Role of Initial Attack and Performer Expertise on Instrument Identification

ERIC Educational Resources Information Center

Cassidy, Jane W.; Schlegel, Amanda L.

2016-01-01

The purpose of this study was to examine the role initial attack and expertise play in the identification of instrumental tones. A stimulus CD was made of 32 excerpts of instrumental tones. Sixteen possible combinations of the variables of initial attack (present or absent), expertise (beginner versus professional), and timbre (flute, clarinet,…

Is it feasible to estimate radiosonde biases from interlaced measurements?

NASA Astrophysics Data System (ADS)

Kremser, Stefanie; Tradowsky, Jordis S.; Rust, Henning W.; Bodeker, Greg E.

2018-05-01

Upper-air measurements of essential climate variables (ECVs), such as temperature, are crucial for climate monitoring and climate change detection. Because of the internal variability of the climate system, many decades of measurements are typically required to robustly detect any trend in the climate data record. It is imperative for the records to be temporally homogeneous over many decades to confidently estimate any trend. Historically, records of upper-air measurements were primarily made for short-term weather forecasts and as such are seldom suitable for studying long-term climate change as they lack the required continuity and homogeneity. Recognizing this, the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) has been established to provide reference-quality measurements of climate variables, such as temperature, pressure, and humidity, together with well-characterized and traceable estimates of the measurement uncertainty. To ensure that GRUAN data products are suitable to detect climate change, a scientifically robust instrument replacement strategy must always be adopted whenever there is a change in instrumentation. By fully characterizing any systematic differences between the old and new measurement system a temporally homogeneous data series can be created. One strategy is to operate both the old and new instruments in tandem for some overlap period to characterize any inter-instrument biases. However, this strategy can be prohibitively expensive at measurement sites operated by national weather services or research institutes. An alternative strategy that has been proposed is to alternate between the old and new instruments, so-called interlacing, and then statistically derive the systematic biases between the two instruments. Here we investigate the feasibility of such an approach specifically for radiosondes, i.e. flying the old and new instruments on alternating days. Synthetic data sets are used to explore the applicability of this statistical approach to radiosonde change management.

Decoupling Solar Variability and Instrument Trends Using the Multiple Same-Irradiance-Level (MuSIL) Analysis Technique

NASA Astrophysics Data System (ADS)

Woods, Thomas N.; Eparvier, Francis G.; Harder, Jerald; Snow, Martin

2018-05-01

The solar spectral irradiance (SSI) dataset is a key record for studying and understanding the energetics and radiation balance in Earth's environment. Understanding the long-term variations of the SSI over timescales of the 11-year solar activity cycle and longer is critical for many Sun-Earth research topics. Satellite measurements of the SSI have been made since the 1970s, most of them in the ultraviolet, but recently also in the visible and near-infrared. A limiting factor for the accuracy of previous solar variability results is the uncertainties for the instrument degradation corrections, which need fairly large corrections relative to the amount of solar cycle variability at some wavelengths. The primary objective of this investigation has been to separate out solar cycle variability and any residual uncorrected instrumental trends in the SSI measurements from the Solar Radiation and Climate Experiment (SORCE) mission and the Thermosphere, Mesosphere, Ionosphere, Energetic, and Dynamics (TIMED) mission. A new technique called the Multiple Same-Irradiance-Level (MuSIL) analysis has been developed, which examines an SSI time series at different levels of solar activity to provide long-term trends in an SSI record, and the most common result is a downward trend that most likely stems from uncorrected instrument degradation. This technique has been applied to each wavelength in the SSI records from SORCE (2003 - present) and TIMED (2002 - present) to provide new solar cycle variability results between 27 nm and 1600 nm with a resolution of about 1 nm at most wavelengths. This technique, which was validated with the highly accurate total solar irradiance (TSI) record, has an estimated relative uncertainty of about 5% of the measured solar cycle variability. The MuSIL results are further validated with the comparison of the new solar cycle variability results from different solar cycles.

Thyroid Signaling, Insulin Resistance, and 2 Diabetes Mellitus: A Mendelian Randomization Study.

PubMed

Bos, Maxime M; Smit, Roelof A J; Trompet, Stella; van Heemst, Diana; Noordam, Raymond

2017-06-01

Increasing evidence suggests an association between thyroid-stimulating hormone (TSH), free thyroxine (fT4), and deiodinases with insulin resistance and type 2 diabetes mellitus (T2D). We examined whether TSH and fT4 levels and deiodinases are causally associated with insulin resistance and T2D, using Mendelian randomization. We selected 20 genetic variants for TSH level and four for fT4 level (identified in a genome-wide association study (GWAS) meta-analysis of European-ancestry cohorts) as instrumental variables for TSH and fT4 levels, respectively. We used summary data from GWASs on the outcomes T2D [Diabetes, Genetics Replication and Meta-analysis (DIAGRAM), n = 12,171 cases and n = 56,862 control subjects] and glycemic traits in patients without diabetes [Meta-Analyses of Glucose and Insulin-Related Traits Consortium (MAGIC), n = 46,186 for fasting glucose and insulin and n = 46,368 for hemoglobin A1c]. To examine whether the associations between TSH/fT4 levels and the study outcomes were causal, we combined the effects of the genetic instruments. Furthermore, we examined the associations among 16 variants in DIO1, DIO2, DIO3, and T2D and glycemic traits. We found no evidence for an association between the combined genetic instrumental variables for TSH and fT4 and the study outcomes. For example, we did not observe a genetically determined association between high TSH level and T2D (odds ratio, 0.91 per standard deviation TSH increase; 95% confidence interval, 0.78 to 1.07). Selected genetic variants in DIO1 (e.g., rs7527713) were associated with measures of insulin resistance. We found no evidence for a causal association between circulatory levels of TSH and fT4 with insulin resistance and T2D, but we found suggestive evidence that DIO1 affects glucose metabolism. Copyright © 2017 by the Endocrine Society

Instruments to Explore Blended Learning: Modifying a Method to Analyse Online Communication for the Analysis of Face-to-Face Communication

ERIC Educational Resources Information Center

de Leng, Bas A.; Dolmans, Diana H. J. M.; Donkers, H. H. L. M.; Muijtjens, Arno M. M.; van der Vleuten, Cees P. M.

2010-01-01

In the complex practice of today's blended learning, educators need to be able to evaluate both online and face-to-face communication in order to get the full picture of what is going on in blended learning scenarios. The aim of this study was to investigate the reliability and feasibility of a practical instrument for analysing face-to-face…

Manufacturing challenge: An employee perception of the impact of BEM variables on motivation

NASA Astrophysics Data System (ADS)

Nyaude, Alaster

The study examines the impact of Thomas F. Gilbert's Behavior Engineering Model (BEM) variables on employee perception of motivation at an aerospace equipment manufacturing plant in Georgia. The research process involved literature review, and determination of an appropriate survey instrument for the study. The Hersey-Chevalier modified PROBE instrument (Appendix C) was used with Dr Roger Chevalier's validation. The participants' responses were further examined to determine the influence of demographic control variables of age, gender, length of service with the company and education on employee perception of motivation. The results indicated that the top three highly motivating variables were knowledge and skills, capacity and resources. Knowledge and skills was perceived to be highly motivating, capacity as second highly motivating and resources as the third highly motivating variable. Interestingly, the fourth highly motivating variable was information, the fifth was motives and the sixth was incentives. The results also showed that demographic control variables had no influence on employee perception of motivation. Further research may be required to understand to what extend these BEM variables impact employee perceptions of motivation.

Cardiopulmonary, blood and peritoneal fluid alterations associated with abdominal insufflation of carbon dioxide in standing horses.

PubMed

Latimer, F G; Eades, S C; Pettifer, G; Tetens, J; Hosgood, G; Moore, R M

2003-05-01

Abdominal insufflation is performed routinely during laparoscopy in horses to improve visualisation and facilitate instrument and visceral manipulations during surgery. It has been shown that high-pressure pneumoperitoneum with carbon dioxide (CO2) has deleterious cardiopulmonary effects in dorsally recumbent, mechanically ventilated, halothane-anaesthetised horses. There is no information on the effects of CO2 pneumoperitoneum on cardiopulmonary function and haematology, plasma chemistry and peritoneal fluid (PF) variables in standing sedated horses during laparoscopic surgery. To determine the effects of high pressure CO2 pneumoperitoneum in standing sedated horses on cardiopulmonary function, blood gas, haematology, plasma chemistry and PF variables. Six healthy, mature horses were sedated with an i.v. bolus of detomidine (0.02 mg/kg bwt) and butorphanol (0.02 mg/kg bwt) and instrumented to determine the changes in cardiopulmonary function, haematology, serum chemistry and PF values during and after pneumoperitoneum with CO2 to 15 mmHg pressure for standing laparoscopy. Each horse was assigned at random to either a standing left flank exploratory laparoscopy (LFL) with CO2 pneumoperitoneum or sham procedure (SLFL) without insufflation, and instrumented for measurement of cardiopulmonary variables. Each horse underwent a second procedure in crossover fashion one month later so that all 6 horses had both an LFL and SLFL performed. Cardiopulmonary variables and blood gas analyses were obtained 5 mins after sedation and every 15 mins during 60 mins baseline (BL), insufflation (15 mmHg) and desufflation. Haematology, serum chemistry analysis and PF analysis were performed at BL, insufflation and desufflation, and 24 h after the conclusion of each procedure. Significant decreases in heart rate, cardiac output and cardiac index and significant increases in mean right atrial pressure, systemic vascular resistance and pulmonary vascular resistance were recorded immediately after and during sedation in both groups of horses. Pneumoperitoneum with CO2 at 15 mmHg had no significant effect on cardiopulmonary function during surgery. There were no significant differences in blood gas, haematology or plasma chemistry values within or between groups at any time interval during the study. There was a significant increase in the PF total nucleated cell count 24 h following LFL compared to baseline values for LFL or SLFL at 24 h. There were no differences in PF protein concentrations within or between groups at any time interval. Pneumoperitoneum with CO2 during standing laparoscopy in healthy horses does not cause adverse alterations in cardiopulmonary, haematology or plasma chemistry variables, but does induce a mild inflammatory response within the peritoneal cavity. High pressure (15 mmHg) pneumoperitoneum in standing sedated mature horses for laparoscopic surgery can be performed safely without any short-term or cumulative adverse effects on haemodynamic or cardiopulmonary function.

8 years of Solar Spectral Irradiance Observations from the ISS with the SOLAR/SOLSPEC Instrument

NASA Astrophysics Data System (ADS)

Damé, L.; Bolsée, D.; Meftah, M.; Irbah, A.; Hauchecorne, A.; Bekki, S.; Pereira, N.; Cessateur, G.; Marchand, M.; Thiéblemont, R.; Foujols, T.

2016-12-01

Accurate measurements of Solar Spectral Irradiance (SSI) are of primary importance for a better understanding of solar physics and of the impact of solar variability on climate (via Earth's atmospheric photochemistry). The acquisition of a top of atmosphere reference solar spectrum and of its temporal and spectral variability during the unusual solar cycle 24 is of prime interest for these studies. These measurements are performed since April 2008 with the SOLSPEC spectro-radiometer from the far ultraviolet to the infrared (166 nm to 3088 nm). This instrument, developed under a fruitful LATMOS/BIRA-IASB collaboration, is part of the Solar Monitoring Observatory (SOLAR) payload, externally mounted on the Columbus module of the International Space Station (ISS). The SOLAR mission, with its actual 8 years duration, will cover almost the entire solar cycle 24. We present here the in-flight operations and performances of the SOLSPEC instrument, including the engineering corrections, calibrations and improved know-how procedure for aging corrections. Accordingly, a SSI reference spectrum from the UV to the NIR will be presented, together with its UV variability, as measured by SOLAR/SOLSPEC. Uncertainties on these measurements and comparisons with other instruments will be briefly discussed.

Instrumental colour of Iberian ham subcutaneous fat and lean (biceps femoris): Influence of crossbreeding and rearing system.

PubMed

Carrapiso, Ana I; García, Carmen

2005-10-01

The influence of crossbreeding (Iberian vs Iberian×Duroc 50% pigs) and rearing system (Montanera vs Pienso) on the instrumental colour of Iberian ham (subcutaneous fat and biceps femoris muscle) and the relationships to sensory appearance and chemical composition were researched by using a factorial design. In subcutaneous fat, a significant effect (p<0.05) of crossbreeding and rearing system was found: b* and chroma were larger in hams from Iberian pigs than from Iberian×Duroc (50%) pigs, and L*, a* and chroma were larger in Pienso hams than in Montanera hams. CIEL*a*b* variables of subcutaneous fat were closely related to subcutaneous fatty acid composition, the largest correlationships involving L* (L* and 18:0, 0.652, p<0.001; L* and 18:1, -0.616, p<0.001). Instrumental colour variables and sensory appearance were also correlated (L* and fat pinkness, -0.539, p<0.001). In lean (biceps femoris), instrumental colour data was not affected by crossbreeding and rearing system. CIEL*a*b* variables were not related to chemical composition (moisture, NaCl, intramuscular fat and pigment content), although they were correlated to sensory appearance (L* and marbling, 0.419, p=0.014).

Multivariate evaluation of the cutting performance of rotary instruments with electric and air-turbine handpieces.

PubMed

Funkenbusch, Paul D; Rotella, Mario; Chochlidakis, Konstantinos; Ercoli, Carlo

2016-10-01

Laboratory studies of tooth preparation often involve single values for all variables other than the one being tested. In contrast, in clinical settings, not all variables can be adequately controlled. For example, a new dental rotary cutting instrument may be tested in the laboratory by making a specific cut with a fixed force, but, in clinical practice, the instrument must make different cuts with individual dentists applying different forces. Therefore, the broad applicability of laboratory results to diverse clinical conditions is uncertain and the comparison of effects across studies difficult. The purpose of this in vitro study was to examine the effects of 9 process variables on the dental cutting of rotary cutting instruments used with an electric handpiece and compare them with those of a previous study that used an air-turbine handpiece. The effects of 9 key process variables on the efficiency of a simulated dental cutting operation were measured. A fractional factorial experiment was conducted by using an electric handpiece in a computer-controlled, dedicated testing apparatus to simulate dental cutting procedures with Macor blocks as the cutting substrate. Analysis of variance (ANOVA) was used to assess the statistical significance (α=.05). Four variables (targeted applied load, cut length, diamond grit size, and cut type) consistently produced large, statistically significant effects, whereas 5 variables (rotation per minute, number of cooling ports, rotary cutting instrument diameter, disposability, and water flow rate) produced relatively small, statistically insignificant effects. These results are generally similar to those previously found for an air-turbine handpiece. Regardless of whether an electric or air-turbine handpiece was used, the control exerted by the dentist, simulated in this study by targeting a specific level of applied force, was the single most important factor affecting cutting efficiency. Cutting efficiency was also significantly affected by factors simulating patient/clinical circumstances and hardware choices. These results highlight the greater importance of local clinical conditions (procedure, dentist) in understanding dental cutting as opposed to other hardware-related factors. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Hand-held instrument should relieve hematoma pressure

NASA Technical Reports Server (NTRS)

Raggio, L. J.; Robertson, T. L.

1967-01-01

Portable instrument relieves hematomas beneath fingernails and toenails without surgery. This device simplifies the operative procedure with an instant variable heating tip, adjustable depth settings and interchangeable tip sizes for cauterizing small areas and relieving pressurized clots.

Surface Meteorological Station - ESRL Short Tower, Wasco Airport - Raw Data

DOE Data Explorer

Gottas, Daniel

2017-12-11

A diversity of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Surface Meteorological Station - ESRL Short Tower, Wasco Airport - Reviewed Data

DOE Data Explorer

Gottas, Daniel

2017-12-11

A diversity of instruments are used to measure various quantities related to meteorology, precipitation, and radiation near the Earth’s surface. Typically, a standard suite of instruments is deployed to monitor meteorological state variables.

Identifying Useful Auxiliary Variables for Incomplete Data Analyses: A Note on a Group Difference Examination Approach

ERIC Educational Resources Information Center

Raykov, Tenko; Marcoulides, George A.

2014-01-01

This research note contributes to the discussion of methods that can be used to identify useful auxiliary variables for analyses of incomplete data sets. A latent variable approach is discussed, which is helpful in finding auxiliary variables with the property that if included in subsequent maximum likelihood analyses they may enhance considerably…

The contextual effects of social capital on health: a cross-national instrumental variable analysis.

PubMed

Kim, Daniel; Baum, Christopher F; Ganz, Michael L; Subramanian, S V; Kawachi, Ichiro

2011-12-01

Past research on the associations between area-level/contextual social capital and health has produced conflicting evidence. However, interpreting this rapidly growing literature is difficult because estimates using conventional regression are prone to major sources of bias including residual confounding and reverse causation. Instrumental variable (IV) analysis can reduce such bias. Using data on up to 167,344 adults in 64 nations in the European and World Values Surveys and applying IV and ordinary least squares (OLS) regression, we estimated the contextual effects of country-level social trust on individual self-rated health. We further explored whether these associations varied by gender and individual levels of trust. Using OLS regression, we found higher average country-level trust to be associated with better self-rated health in both women and men. Instrumental variable analysis yielded qualitatively similar results, although the estimates were more than double in size in both sexes when country population density and corruption were used as instruments. The estimated health effects of raising the percentage of a country's population that trusts others by 10 percentage points were at least as large as the estimated health effects of an individual developing trust in others. These findings were robust to alternative model specifications and instruments. Conventional regression and to a lesser extent IV analysis suggested that these associations are more salient in women and in women reporting social trust. In a large cross-national study, our findings, including those using instrumental variables, support the presence of beneficial effects of higher country-level trust on self-rated health. Previous findings for contextual social capital using traditional regression may have underestimated the true associations. Given the close linkages between self-rated health and all-cause mortality, the public health gains from raising social capital within and across countries may be large. Copyright © 2011 Elsevier Ltd. All rights reserved.

The contextual effects of social capital on health: a cross-national instrumental variable analysis

PubMed Central

Kim, Daniel; Baum, Christopher F; Ganz, Michael; Subramanian, S V; Kawachi, Ichiro

2011-01-01

Past observational studies of the associations of area-level/contextual social capital with health have revealed conflicting findings. However, interpreting this rapidly growing literature is difficult because estimates using conventional regression are prone to major sources of bias including residual confounding and reverse causation. Instrumental variable (IV) analysis can reduce such bias. Using data on up to 167 344 adults in 64 nations in the European and World Values Surveys and applying IV and ordinary least squares (OLS) regression, we estimated the contextual effects of country-level social trust on individual self-rated health. We further explored whether these associations varied by gender and individual levels of trust. Using OLS regression, we found higher average country-level trust to be associated with better self-rated health in both women and men. Instrumental variable analysis yielded qualitatively similar results, although the estimates were more than double in size in women and men using country population density and corruption as instruments. The estimated health effects of raising the percentage of a country's population that trusts others by 10 percentage points were at least as large as the estimated health effects of an individual developing trust in others. These findings were robust to alternative model specifications and instruments. Conventional regression and to a lesser extent IV analysis suggested that these associations are more salient in women and in women reporting social trust. In a large cross-national study, our findings, including those using instrumental variables, support the presence of beneficial effects of higher country-level trust on self-rated health. Past findings for contextual social capital using traditional regression may have underestimated the true associations. Given the close linkages between self-rated health and all-cause mortality, the public health gains from raising social capital within countries may be large. PMID:22078106

[Design and validation of a brief questionnaire to assess young´s sexual knowledge].

PubMed

Leon-Larios, Fátima; Gómez-Baya, Diego

2018-06-01

Only very few instruments have been developed to assess sexual knowledge and practices. Most of the research to date has been carried out with adolescent samples, but not with university students, who are also at a particularly risky stage. The aim of this study was to design and validate a brief questionnaire to assess young´s sexual knowledge, practices and behaviors to design health education programs in the university context. We created a specific questionnaire about sexual pattern in university adolescents and a brief questionnaire consisted of 9 items (true/false) about contraception, sexuality and sexual transmission diseases. We carried out a pilot study, reliability (KR-20) and validity analyses using factorial analysis and examining the association with other variables. 566 students from University of Seville participated during 2015/16. One item was eliminated because of comprehension (only 13.9% of correct answers) and weak or non significant associations (p more than 0.05). Finally, the scale was formed by 8 items and had good internal consistency reliability (KR-20 = 0.57), and both factorial and external validity reliability. A three-factor model showed good data fit, χ2 (14, N=566)=17.48, p= 0.232, Comparative Fit Index CFI = 0.97, root mean squared error of prediction RMSEA = 0.02. Participants with less knowledge about sexuality were whose did not receive any information (M=6.82, SD=1.41), without partner (M=6.87, SD=1.35), had an abortion (M=6.43, SD=1.95) and did not use any contraceptive method (M=6.66, SD=0.58) or coitus interruptus (M=6.55, SD=1.39), and had less sexual relationships, e.g., once or twice a year (M=6.49, SD=1.70). This questionnaire is a short instrument to assess students´ practices and knowledge about sexuality and contraception. The analyses of reliability and validity have shown the good psychometric properties of this instrument.

Instrument Suite for Vertical Characterization of the Ionosphere-Thermosphere System

NASA Technical Reports Server (NTRS)

Herrero, Federico; Jones, Hollis; Finne, Theodore; Nicholas, Andrew

2012-01-01

A document describes a suite that provides four simultaneous ion and neutral-atom measurements as a function of altitude, with variable sensitivity for neutral atmospheric species. The variable sensitivity makes it possible to extend the measurements over the altitude range of 100 to more than 700 km. The four instruments in the suite are (1) a neutral wind-temperature spectrometer (WTS), (2) an ion-drift ion-temperature spectrometer (IDTS), (3) a neutral mass spectrometer (NMS), and (4) an ion mass spectrometer (IMS).

Optimised design of a ROTAX-type instrument

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tietze-Jaensch, H.

1997-09-01

The rotating analyser (ROTAX) spectrometer has been devised and installed at ISIS. Practical scans in (Q{h_bar}{omega}) space with a nearly arbitrary scan direction, i.e. polarisation of q vs. Q are possible and feasible with no compromises on the resolution. Valuable technological and methodological knowledge has been compiled for an improved version of such a type of instrument. At present ROTAX lacks competitiveness with other spectrometers from an unexpectedly weak neutron flux of its particular beam-line and an unfavourable adaption of the analyser`s drive power to the time frame or neutron source frequency.

Predictors of unmet needs and psychological distress in adolescent and young adult siblings of people diagnosed with cancer.

PubMed

McDonald, F E J; Patterson, P; White, K J; Butow, P; Bell, M L

2015-03-01

Predictors of psychological distress and unmet needs amongst adolescents and young adults (AYAs) who have a brother or sister diagnosed with cancer were examined. There were 106 AYAs (12-24 years old) who completed questionnaires covering demographics, psychological distress (Kessler 10), unmet needs (Sibling Cancer Needs Instrument) and family relationships (Family Relationship Index; Adult Sibling Relationship Questionnaire; Sibling Perception Questionnaire (SPQ)). Three models were analysed (demographic variables, cancer-specific variables and family functioning variables) using multiple linear regression to determine the role of the variables in predicting psychological distress and unmet needs. Unmet needs were higher for AYA siblings when treatment was current or a relapse had occurred. Higher scores on the SPQ-Interpersonal subscale indicating a perceived decrease in the quality of relationships with parents and others were associated with higher levels of distress and unmet needs. The age and gender of the AYA sibling, whether it was their brother or sister who was diagnosed with cancer, the age difference between them, the number of parents living with the AYA sibling, parental birth country, time since diagnosis, Family Relationship Index, Adult Sibling Relationship Questionnaire and the SPQ-Communication subscale did not significantly impact outcome variables. These results highlight the variables that can assist in identifying AYA siblings of cancer patients who are at risk and have a greater need for psychosocial assistance. Variables that may be associated with increased distress and unmet needs are reported to assist with future research. The results are also useful in informing the development of targeted psychosocial support for AYA siblings of cancer patients. Copyright © 2014 John Wiley & Sons, Ltd.

[A survey instrument for evaluating psychological variables and risky sexual behavior among young adults at two university centers in Mexico].

PubMed

Piña López, Julio A; Robles Montijo, Susana; Rivera Icedo, Blanca M

2007-11-01

To measure the psychometric attributes of a survey instrument designed to evaluate historical and context variables that lead to high-risk sexual behaviors among a sample of university students in Mexico. Cross-sectional study of a sample of 1 346 university students in Mexico: 784 from the Sonora State Center for Higher Education in Hermosillo, Sonora, or 33.2% of its total enrollment; and 562 from the National Autonomous University of Mexico, at Tlalnepantla campus in Mexico State, or 23.5% of its total enrollment. The study took place in Hermosillo during the month of October 2006 and in Tlalnepantla from January to March 2006. The survey had 11 questions on sociodemographics, 7 on risky sexual behaviors, 22 on related motives, 8 on social context, and 6 on physical status prior to sexual relations. The survey was evaluated in terms of how well the questions were understood, its conceptual validity, and reliability. The final version of the survey instrument was composed of 44 questions. The reliability analysis produced an overall Cronbach alpha value of 0.821, taking into account all the variables combined and grouped by factor. Three factors were found that together accounted for 38.36% of the total variance: reasons for not using a condom in the first sexual relationship or throughout life, reasons for inconsistent use of a condom with a casual sex partner, and willingness to become sexually active and to engage in casual sex. The psychometric attributes of this survey instrument were found to be satisfactory. Those interested in using this instrument should become familiar with the theoretical model on which it is based, since understanding the results depends on properly defining the historical and context variables, and their interaction.

Applying Propensity Score Methods in Medical Research: Pitfalls and Prospects

PubMed Central

Luo, Zhehui; Gardiner, Joseph C.; Bradley, Cathy J.

2012-01-01

The authors review experimental and nonexperimental causal inference methods, focusing on assumptions for the validity of instrumental variables and propensity score (PS) methods. They provide guidance in four areas for the analysis and reporting of PS methods in medical research and selectively evaluate mainstream medical journal articles from 2000 to 2005 in the four areas, namely, examination of balance, overlapping support description, use of estimated PS for evaluation of treatment effect, and sensitivity analyses. In spite of the many pitfalls, when appropriately evaluated and applied, PS methods can be powerful tools in assessing average treatment effects in observational studies. Appropriate PS applications can create experimental conditions using observational data when randomized controlled trials are not feasible and, thus, lead researchers to an efficient estimator of the average treatment effect. PMID:20442340

Information security of power enterprises of North-Arctic region

NASA Astrophysics Data System (ADS)

Sushko, O. P.

2018-05-01

The role of information technologies in providing technological security for energy enterprises is a component of the economic security for the northern Arctic region in general. Applying instruments and methods of information protection modelling of the energy enterprises' business process in the northern Arctic region (such as Arkhenergo and Komienergo), the authors analysed and identified most frequent risks of information security. With the analytic hierarchy process based on weighting factor estimations, information risks of energy enterprises' technological processes were ranked. The economic estimation of the information security within an energy enterprise considers weighting factor-adjusted variables (risks). Investments in information security systems of energy enterprises in the northern Arctic region are related to necessary security elements installation; current operating expenses on business process protection systems become materialized economic damage.

Interpretation of the molecular fluxes measured at the periphery of a magnetically confined plasma

NASA Astrophysics Data System (ADS)

Liu-Hinz, C.; Terreault, B.; Martin, F.

1995-04-01

A new instrument ("Variable Geometry Sniffer Probe" or VGSP), allowing one to sample and mass analyse atoms, ions or molecules moving in different directions and at different locations at the periphery of a plasma, has been built and used in plasma edge studies in the TdeV tokamak. Three different regimes of particle sampling have been identified. First, the VGSP can measure the fluxes of hydrogen and impurity molecules issuing from the walls. Second, it has the capability of detecting low energy charge-exchange and Franck-Condon neutrals. Finally, there is a parallel ion flux sampling regime, for which it is shown that both the connection lengths to the divertor plates and the X × B plasma flows induced by edge electric fields play major roles.

Uncertainty in counting ice nucleating particles with continuous flow diffusion chambers

DOE PAGES

Garimella, Sarvesh; Rothenberg, Daniel A.; Wolf, Martin J.; ...

2017-09-14

This study investigates the measurement of ice nucleating particle (INP) concentrations and sizing of crystals using continuous flow diffusion chambers (CFDCs). CFDCs have been deployed for decades to measure the formation of INPs under controlled humidity and temperature conditions in laboratory studies and by ambient aerosol populations. These measurements have, in turn, been used to construct parameterizations for use in models by relating the formation of ice crystals to state variables such as temperature and humidity as well as aerosol particle properties such as composition and number. We show here that assumptions of ideal instrument behavior are not supported by measurements mademore » with a commercially available CFDC, the SPectrometer for Ice Nucleation (SPIN), and the instrument on which it is based, the Zurich Ice Nucleation Chamber (ZINC). Non-ideal instrument behavior, which is likely inherent to varying degrees in all CFDCs, is caused by exposure of particles to different humidities and/or temperatures than predicated from instrument theory of operation. This can result in a systematic, and variable, underestimation of reported INP concentrations. Here we find here variable correction factors from 1.5 to 9.5, consistent with previous literature values. We use a machine learning approach to show that non-ideality is most likely due to small-scale flow features where the aerosols are combined with sheath flows. Machine learning is also used to minimize the uncertainty in measured INP concentrations. Finally, we suggest that detailed measurement, on an instrument-by-instrument basis, be performed to characterize this uncertainty.« less

A study of the effects of gender and different instructional media (computer-assisted instruction tutorials vs. textbook) on student attitudes and achievement in a team-taught integrated science class

NASA Astrophysics Data System (ADS)

Eardley, Julie Anne

The purpose of this study was to determine the effect of different instructional media (computer assisted instruction (CAI) tutorial vs. traditional textbook) on student attitudes toward science and computers and achievement scores in a team-taught integrated science course, ENS 1001, "The Whole Earth Course," which was offered at Florida Institute of Technology during the Fall 2000 term. The effect of gender on student attitudes toward science and computers and achievement scores was also investigated. This study employed a randomized pretest-posttest control group experimental research design with a sample of 30 students (12 males and 18 females). Students had registered for weekly lab sessions that accompanied the course and had been randomly assigned to the treatment or control group. The treatment group used a CAI tutorial for completing homework assignments and the control group used the required textbook for completing homework assignments. The Attitude toward Science and Computers Questionnaire and Achievement Test were the two instruments administered during this study to measure students' attitudes and achievement score changes. A multivariate analysis of covariance (MANCOVA), using hierarchical multiple regression/correlation (MRC), was employed to determine: (1) treatment versus control group attitude and achievement differences; and (2) male versus female attitude and achievement differences. The differences between the treatment group's and control group's homework averages were determined by t test analyses. The overall MANCOVA model was found to be significant at p < .05. Examining research factor set independent variables separately resulted in gender being the only variable that significantly contributed in explaining the variability in a dependent variable, attitudes toward science and computers. T test analyses of the homework averages showed no significant differences. Contradictory to the findings of this study, anecdotal information from personal communication, course evaluations, and homework assignments indicated favorable attitudes and higher achievement scores for a majority of the students in the treatment group.

Direct-to-consumer advertising and the patient-physician relationship.

PubMed

Shah, Mansi B; Bentley, John P; McCaffrey, David J; Kolassa, E Mick

2005-06-01

Differences in attitudes of patients and physicians toward direct-to-consumer advertising (DTCA) of prescription medications may influence the patient-physician relationship, which may in turn influence health care outcomes. The objective of this study was to provide empirical evidence to show how the patient-physician relationship may be influenced by DTCA. The study used a cross-sectional research design. Pharmacists at 71 pharmacies were asked to distribute self-report survey instruments to patients who used either a proton-pump inhibitor or a nonsedating antihistamine by prescription. Data were collected between March and June 2003. Hierarchical multiple regression was used to assess the research propositions. A usable response rate of 7.3% (n=326) was obtained. About 95% of the sample had seen an advertisement for either a proton-pump inhibitor or a nonsedating antihistamine. Response to DTCA was significantly related to the patient's satisfaction with the physician and the patient's evaluation of communication, even after controlling for demographic variables and length of the patient-physician relationship. Other outcome variables (trust, relationship commitment, and average visit time) were not significantly related to DTCA response. Post hoc analyses revealed that DTCA responders, who asked their doctor to prescribe a specific product after seeing its advertisement, rated satisfaction and communication lower than the DTCA nonresponders. Additional follow-up analyses showed that these findings were largely attributed to patients in the proton-pump inhibitor group. The findings suggest that response to DTCA may be significantly related to patients' evaluation of communication quality and their satisfaction with the physician. However, these findings may not generalize to all medical conditions or types of patient. Furthermore, DTCA response does not appear to be related to other patient-physician relationship outcome variables. Given these findings, key variables to explore in future DTCA research with respect to its effect on the patient-physician relationship include patient expectations and disease/condition type.

Variable Stars in the Field of V729 Aql

NASA Astrophysics Data System (ADS)

Cagaš, P.

2017-04-01

Wide field instruments can be used to acquire light curves of tens or even hundreds of variable stars per night, which increases the probability of new discoveries of interesting variable stars and generally increases the efficiency of observations. At the same time, wide field instruments produce a large amount of data, which must be processed using advanced software. The traditional approach, typically used by amateur astronomers, requires an unacceptable amount of time needed to process each data set. New functionality, built into SIPS software package, can shorten the time needed to obtain light curves by several orders of magnitude. Also, newly introduced SILICUPS software is intended for post-processing of stored light curves. It can be used to visualize observations from many nights, to find variable star periods, evaluate types of variability, etc. This work provides an overview of tools used to process data from the large field of view around the variable star V729 Aql. and demonstrates the results.

Evaluating nursing administration instruments.

PubMed

Huber, D L; Maas, M; McCloskey, J; Scherb, C A; Goode, C J; Watson, C

2000-05-01

To identify and evaluate available measures that can be used to examine the effects of management innovations in five important areas: autonomy, conflict, job satisfaction, leadership, and organizational climate. Management interventions target the context in which care is delivered and through which evidence for practice diffuses. These innovations need to be evaluated for their effects on desired outcomes. However, busy nurses may not have the time to locate, evaluate, and select instruments to measure expected nursing administration outcomes without research-based guidance. Multiple and complex important contextual variables need psychometrically sound and easy-to-use measurement instruments identified for use in both practice and research. An expert focus group consensus methodology was used in this evaluation research to review available instruments in the five areas and evaluate which of these instruments are psychometrically sound and easy to use in the practice setting. The result is a portfolio of measures, clustered by concept and displayed on a spreadsheet. Retrieval information is provided. The portfolio includes the expert consensus judgment as well as useful descriptive information. The research reported here identifies psychometrically sound and easy-to-use instruments for measuring five key variables to be included in a portfolio. The results of this study can be used as a beginning for saving time in instrument selection and as an aid for determining the best instrument for measuring outcomes from a clinical or management intervention.

Linear and non-linear analyses of Conner's Continuous Performance Test-II discriminate adult patients with attention deficit hyperactivity disorder from patients with mood and anxiety disorders.

PubMed

Fasmer, Ole Bernt; Mjeldheim, Kristin; Førland, Wenche; Hansen, Anita L; Syrstad, Vigdis Elin Giæver; Oedegaard, Ketil J; Berle, Jan Øystein

2016-08-11

Attention Deficit Hyperactivity Disorder (ADHD) is a heterogeneous disorder. Therefore it is important to look for factors that can contribute to better diagnosis and classification of these patients. The aims of the study were to characterize adult psychiatric out-patients with a mixture of mood, anxiety and attentional problems using an objective neuropsychological test of attention combined with an assessment of mood instability. Newly referred patients (n = 99; aged 18-65 years) requiring diagnostic evaluation of ADHD, mood or anxiety disorders were recruited, and were given a comprehensive diagnostic evaluation including the self-report form of the cyclothymic temperament scale and Conner's Continuous Performance Test II (CPT-II). In addition to the traditional measures from this test we have extracted raw data and analysed time series using linear and non-linear mathematical methods. Fifty patients fulfilled criteria for ADHD, while 49 did not, and were given other psychiatric diagnoses (clinical controls). When compared to the clinical controls the ADHD patients had more omission and commission errors, and higher reaction time variability. Analyses of response times showed higher values for skewness in the ADHD patients, and lower values for sample entropy and symbolic dynamics. Among the ADHD patients 59 % fulfilled criteria for a cyclothymic temperament, and this group had higher reaction time variability and lower scores on complexity than the group without this temperament. The CPT-II is a useful instrument in the assessment of ADHD in adult patients. Additional information from this test was obtained by analyzing response times using linear and non-linear methods, and this showed that ADHD patients with a cyclothymic temperament were different from those without this temperament.

[Integral health provision by two Catalonian health providing entities (Spain)].

PubMed

Henao-Martínez, Diana; Vázquez-Navarrete, María L; Vargas-Lorenzo, Ingrid; Coderch-Lassaletta, Jordi; Llopart-López, Josep R

2008-01-01

Health policies aimed at promoting collaboration amongst providers have led to different initiatives, amongst them integrated healthcare delivery systems (IDS); these have been analysed mainly in the USA but hardly so in Colombia or Spain . This article thus analyses the experience of two IDS in Catalonia for identifying elements for improvement. This was a case-study carried out via individual semi-structured interviews and analysing documents. Two IDS were selected; a sample of documents and reports providing information on analysis variables were selected for each case. Content was analysed via mixed categories and segmentation by cases and topics. Both IDS are health-care providing organisations presenting backward vertical integration, having total internal service production and virtual integration of ownership. BSA is funded by providing services whilst SSIBE relies on shareholding via capitation pilot test. Both have closely coordinated multiple managing bodies and have defined overall strategies orientated towards coordination and efficiency; they differ regarding implementation time. BSA has a divisional structure and SSIBE a functional one, organised by transversal areas. Clinical coordination is based on standardising processes and abilities, having few mechanisms for mutual adaptation and disparity in the number of instruments implemented. Both organisations presented enabling and hindering factors for clinical coordination which would need changes in internal and external components in order to improve overall efficiency and health care continuity.

Thermal design and performance of the REgolith x-ray imaging spectrometer (REXIS) instrument

NASA Astrophysics Data System (ADS)

Stout, Kevin D.; Masterson, Rebecca A.

2014-08-01

The REgolith X-ray Imaging Spectrometer (REXIS) instrument is a student collaboration instrument on the OSIRIS-REx asteroid sample return mission scheduled for launch in September 2016. The REXIS science mission is to characterize the elemental abundances of the asteroid Bennu on a global scale and to search for regions of enhanced elemental abundance. The thermal design of the REXIS instrument is challenging due to both the science requirements and the thermal environment in which it will operate. The REXIS instrument consists of two assemblies: the spectrometer and the solar X-ray monitor (SXM). The spectrometer houses a 2x2 array of back illuminated CCDs that are protected from the radiation environment by a one-time deployable cover and a collimator assembly with coded aperture mask. Cooling the CCDs during operation is the driving thermal design challenge on the spectrometer. The CCDs operate in the vicinity of the electronics box, but a 130 °C thermal gradient is required between the two components to cool the CCDs to -60 °C in order to reduce noise and obtain science data. This large thermal gradient is achieved passively through the use of a copper thermal strap, a large radiator facing deep space, and a two-stage thermal isolation layer between the electronics box and the DAM. The SXM is mechanically mounted to the sun-facing side of the spacecraft separately from the spectrometer and characterizes the highly variable solar X-ray spectrum to properly interpret the data from the asteroid. The driving thermal design challenge on the SXM is cooling the silicon drift detector (SDD) to below -30 °C when operating. A two-stage thermoelectric cooler (TEC) is located directly beneath the detector to provide active cooling, and spacecraft MLI blankets cover all of the SXM except the detector aperture to radiatively decouple the SXM from the flight thermal environment. This paper describes the REXIS thermal system requirements, thermal design, and analyses, with a focus on the driving thermal design challenges for the instrument. It is shown through both analysis and early testing that the REXIS instrument can perform successfully through all phases of its mission.

Feedback control of acoustic musical instruments: collocated control using physical analogs.

PubMed

Berdahl, Edgar; Smith, Julius O; Niemeyer, Günter

2012-01-01

Traditionally, the average professional musician has owned numerous acoustic musical instruments, many of them having distinctive acoustic qualities. However, a modern musician could prefer to have a single musical instrument whose acoustics are programmable by feedback control, where acoustic variables are estimated from sensor measurements in real time and then fed back in order to influence the controlled variables. In this paper, theory is presented that describes stable feedback control of an acoustic musical instrument. The presentation should be accessible to members of the musical acoustics community who may have limited or no experience with feedback control. First, the only control strategy guaranteed to be stable subject to any musical instrument mobility is described: the sensors and actuators must be collocated, and the controller must emulate a physical analog system. Next, the most fundamental feedback controllers and the corresponding physical analog systems are presented. The effects that these controllers have on acoustic musical instruments are described. Finally, practical design challenges are discussed. A proof explains why changing the resonance frequency of a musical resonance requires much more control power than changing the decay time of the resonance. © 2012 Acoustical Society of America.

Ozone Depletion at Mid-Latitudes: Coupling of Volcanic Aerosols and Temperature Variability to Anthropogenic Chlorine

NASA Technical Reports Server (NTRS)

Solomon, S.; Portmann, R. W.; Garcia, R. R.; Randel, W.; Wu, F.; Nagatani, R.; Gleason, J.; Thomason, L.; Poole, L. R.; McCormick, M. P.

1998-01-01

Satellite observations of total ozone at 40-60 deg N are presented from a variety of instruments over the time period 1979-1997. These reveal record low values in 1992-3 (after Pinatubo) followed by partial but incomplete recovery. The largest post-Pinatubo reductions and longer-term trends occur in spring, providing a critical test for chemical theories of ozone depletion. The observations are shown to be consistent with current understanding of the chemistry of ozone depletion when changes in reactive chlorine and stratospheric aerosol abundances are considered along with estimates of wave-driven fluctuations in stratospheric temperatures derived from global temperature analyses. Temperature fluctuations are shown to make significant contributions to model calculated northern mid-latitude ozone depletion due to heterogeneous chlorine activation on liquid sulfate aerosols at temperatures near 200-210 K (depending upon water vapor pressure), particularly after major volcanic eruptions. Future mid-latitude ozone recovery will hence depend not only on chlorine recovery but also on temperature trends and/or variability, volcanic activity, and any trends in stratospheric sulfate aerosol.

Health and labour force participation of older people in Europe: what do objective health indicators add to the analysis?

PubMed

Kalwij, Adriaan; Vermeulen, Frederic

2008-05-01

This paper studies labour force participation of older individuals in 11 European countries. The data are drawn from the new Survey of Health, Ageing and Retirement in Europe (SHARE). We examine the value added of objective health indicators in relation to potentially endogenous self-reported health. We approach the endogeneity of self-reported health as an omitted variables problem. In line with the literature on the reliability of self-reported health ambiguous results are obtained. In some countries self-reported health does a fairly good job and controlling for objective health indicators does not add much to the analysis. In other countries, however, the results show that objective health indicators add significantly to the analysis and that self-reported health is endogenous due to omitted objective health indicators. These latter results illustrate the multi-dimensional nature of health and the need to control for objective health indicators when analysing the relation between health status and labour force participation. This makes an instrumental variables approach to deal with the endogeneity of self-reported health less appropriate.

Developments in Post-marketing Comparative Effectiveness Research

PubMed Central

S, Schneeweiss

2010-01-01

Physicians and insurers need to weigh the effectiveness of new drugs against existing therapeutics in routine care to make decisions about treatment and formularies. Because Food and Drug Administration (FDA) approval of most new drugs requires demonstrating efficacy and safety against placebo, there is limited interest by manufacturers in conducting such head-to-head trials. Comparative effectiveness research seeks to provide head-to-head comparisons of treatment outcomes in routine care. Health-care utilization databases record drug use and selected health outcomes for large populations in a timely way and reflect routine care, and therefore may be the preferred data source for comparative effectiveness research. Confounding caused by selective prescribing based on indication, severity, and prognosis threatens the validity of non-randomized database studies that often have limited details on clinical information. Several recent developments may bring the field closer to acceptable validity, including approaches that exploit the concepts of proxy variables using high-dimensional propensity scores, within-patient variation of drug exposure using crossover designs, and between-provider variation in prescribing preference using instrumental variable (IV) analyses. PMID:17554243

Voluntary Field Data Collection for Landscape Phenology and Surface Water Essential Climate Variable Research

NASA Astrophysics Data System (ADS)

Jones, J. W.; Hudson-Dunn, A.; Aquino, K.; Pasa, M.; Paez, F.

2013-12-01

The U.S. Geological Survey is developing techniques to monitor vegetation and surface water condition for improved resource management. Educational materials and data forms that allow volunteer Citizen Scientists to collect information on vegetation and surface water extent to enhance satellite and web camera data analyses (http://egsc.usgs.gov/shenandoah.html) have been developed, tested, and refined. Collection is focused on supplementing landscape phenology and surface water extent (SWE) essential climate variable (ECV) research. Low cost instrumentation, subject education, and measurement calibration techniques all have utility for multiple remote sensing and biophysical studies. Trials have been conducted with subjects ranging from elementary school-aged summer camp children to science major undergraduate and graduate students. Experiments were replicated in several project study areas in Virginia that are also phenology and SWE-ECV research sites. Analysis of volunteer responses and their narrative feedback have improved the ability to request and assess data from volunteers. Children ages 12 and over were able to provide reliable supplemental information for phenology and aquatic research. Finally, trial observation and subject feedback both confirmed that participation furthered volunteer interest in science.

Evaluating the Vertical Distribution of Ozone and its Relationship to Pollution Events in Air Quality Models using Satellite Data

NASA Astrophysics Data System (ADS)

Osterman, G. B.; Neu, J. L.; Eldering, A.; Pinder, R. W.; Tang, Y.; McQueen, J.

2014-12-01

Most regional scale models that are used for air quality forecasts and ozone source attribution do not adequately capture the distribution of ozone in the mid- and upper troposphere, but it is unclear how this shortcoming relates to their ability to simulate surface ozone. We combine ozone profile data from the NASA Earth Observing System (EOS) Tropospheric Emission Spectrometer (TES) and a new joint product from TES and the Ozone Monitoring Instrument along with ozonesonde measurements and EPA AirNow ground station ozone data to examine air quality events during August 2006 in the Community Multi-Scale Air Quality (CMAQ) and National Air Quality Forecast Capability (NAQFC) models. We present both aggregated statistics and case-study analyses with the goal of assessing the relationship between the models' ability to reproduce surface air quality events and their ability to capture the vertical distribution of ozone. We find that the models lack the mid-tropospheric ozone variability seen in TES and the ozonesonde data, and discuss the conditions under which this variability appears to be important for surface air quality.

Comparing Bilingual to Monolingual Learners on English Spelling: A Meta-analytic Review.

PubMed

Zhao, Jing; Quiroz, Blanca; Dixon, L Quentin; Joshi, R Malatesha

2016-08-01

This study reports on a meta-analysis to examine how bilingual learners compare with English monolingual learners on two English spelling outcomes: real-word spelling and pseudo-word spelling. Eighteen studies published in peer-reviewed journals between 1990 and 2014 were retrieved. The study-level variables and characteristics (e.g. sample size, study design and research instruments) were coded, and 29 independent effect sizes across the 18 retrieved studies were analysed. We found that bilinguals outperformed monolinguals on real-word spelling overall and more so in early grades, but monolinguals outperformed bilinguals on pseudo-word spelling. Further, bilinguals at risk for reading difficulties did better on real-word spelling than monolinguals at risk for reading difficulties. Having investigated systematic sources of variability in effect sizes, we conclude that in comparison with their monolingual peers, bilingual learners, especially those from alphabetic L1 backgrounds, are able to master constrained skills, such as English spelling, in the current instructional context. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Developments in post-marketing comparative effectiveness research.

PubMed

Schneeweiss, S

2007-08-01

Physicians and insurers need to weigh the effectiveness of new drugs against existing therapeutics in routine care to make decisions about treatment and formularies. Because Food and Drug Administration (FDA) approval of most new drugs requires demonstrating efficacy and safety against placebo, there is limited interest by manufacturers in conducting such head-to-head trials. Comparative effectiveness research seeks to provide head-to-head comparisons of treatment outcomes in routine care. Health-care utilization databases record drug use and selected health outcomes for large populations in a timely way and reflect routine care, and therefore may be the preferred data source for comparative effectiveness research. Confounding caused by selective prescribing based on indication, severity, and prognosis threatens the validity of non-randomized database studies that often have limited details on clinical information. Several recent developments may bring the field closer to acceptable validity, including approaches that exploit the concepts of proxy variables using high-dimensional propensity scores, within-patient variation of drug exposure using crossover designs, and between-provider variation in prescribing preference using instrumental variable (IV) analyses.

Instrumentation and Performance Analysis Plans for the HIFiRE Flight 2 Experiment

NASA Technical Reports Server (NTRS)

Gruber, Mark; Barhorst, Todd; Jackson, Kevin; Eklund, Dean; Hass, Neal; Storch, Andrea M.; Liu, Jiwen

2009-01-01

Supersonic combustion performance of a bi-component gaseous hydrocarbon fuel mixture is one of the primary aspects under investigation in the HIFiRE Flight 2 experiment. In-flight instrumentation and post-test analyses will be two key elements used to determine the combustion performance. Pre-flight computational fluid dynamics (CFD) analyses provide valuable information that can be used to optimize the placement of a constrained set of wall pressure instrumentation in the experiment. The simulations also allow pre-flight assessments of performance sensitivities leading to estimates of overall uncertainty in the determination of combustion efficiency. Based on the pre-flight CFD results, 128 wall pressure sensors have been located throughout the isolator/combustor flowpath to minimize the error in determining the wall pressure force at Mach 8 flight conditions. Also, sensitivity analyses show that mass capture and combustor exit stream thrust are the two primary contributors to uncertainty in combustion efficiency.

Further Exploring the Potential for Assimilation of Unmanned Aircraft Observations to Benefit Hurricane Analyses and Forecasts

NASA Technical Reports Server (NTRS)

Sippel, Jason A.; Zhang, Fuqing; Weng, Yonghui; Braun, Scott A.; Cecil, Daniel J.

2015-01-01

This study explores the potential of assimilating data from multiple instruments onboard high-altitude, long-endurance unmanned aircraft to improve hurricane analyses and forecasts. A recent study found a significant positive impact on analyses and forecasts of Hurricane Karl when an ensemble Kalman filter was used to assimilate data from the High-altitude Imaging Wind and Rain Airborne Profiler (HIWRAP), a new Doppler radar onboard the NASA Global Hawk (GH) unmanned airborne system. The GH can also carry other useful instruments, including dropsondes and the Hurricane Imaging Radiometer (HIRAD), which is a new radiometer that estimates large swaths of wind speeds and rainfall at the ocean surface. The primary finding is that simultaneously assimilating data from HIWRAP and the other GH-compatible instruments results in further analysis and forecast improvement for Karl. The greatest improvement comes when HIWRAP, HIRAD, and dropsonde data are simultaneously assimilated.

Star 48 solid rocket motor nozzle analyses and instrumented firings

NASA Technical Reports Server (NTRS)

Porter, R. L.

1986-01-01

The analyses and testing performed by NASA in support of an expanded and improved nozzle design data base for use by the U.S. solid rocket motor industry is presented. A production nozzle with a history of one ground failure and two flight failures was selected for analyses and testing. The stress analysis was performed with the Champion computer code developed by the U.S. Navy. Several improvements were made to the code. Strain predictions were made and compared to test data. Two short duration motor firings were conducted with highly instrumented nozzles. The first nozzle had 58 thermocouples, 66 strain gages, and 8 bondline pressure measurements. The second nozzle had 59 thermocouples, 68 strain measurements, and 8 bondline pressure measurements. Most of this instrumentation was on the nonmetallic parts, and provided significantly more thermal and strain data on the nonmetallic components of a nozzle than has been accumulated in a solid rocket motor test to date.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1990. The ACL has four technical groups -- Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis. The Chemical Analysis Group uses wet-chemical and instrumental methods for elemental, compositional, and isotopic analyses of solid, liquid, and gaseous samples and provides specialized analytical services. The Instrumental Analysis Group uses nuclear counting techniques in radiochemical analyses over a wide range of sample types from low-level environmental samples to samples of high radioactivity. The Organic Analysis Group uses amore » number of complementary techniques to separate and to quantitatively and qualitatively analyze complex organic mixtures and compounds at the trace level, including synthetic fuels, toxic substances, fossil-fuel residues and emissions, pollutants, biologically active compounds, pesticides, and drugs. The Environmental Analysis Group performs analyses of inorganic environmental and hazardous waste and coal samples.« less

Designed experiment evaluation of key variables affecting the cutting performance of rotary instruments.

PubMed

Funkenbusch, Paul D; Rotella, Mario; Ercoli, Carlo

2015-04-01

Laboratory studies of tooth preparation are often performed under a limited range of conditions involving single values for all variables other than the 1 being tested. In contrast, in clinical settings not all variables can be tightly controlled. For example, a new dental rotary cutting instrument may be tested in the laboratory by making a specific cut with a fixed force, but in clinical practice, the instrument must make different cuts with individual dentists applying a range of different forces. Therefore, the broad applicability of laboratory results to diverse clinical conditions is uncertain and the comparison of effects across studies is difficult. The purpose of this study was to examine the effect of 9 process variables on dental cutting in a single experiment, allowing each variable to be robustly tested over a range of values for the other 8 and permitting a direct comparison of the relative importance of each on the cutting process. The effects of 9 key process variables on the efficiency of a simulated dental cutting operation were measured. A fractional factorial experiment was conducted by using a computer-controlled, dedicated testing apparatus to simulate dental cutting procedures and Macor blocks as the cutting substrate. Analysis of Variance (ANOVA) was used to judge the statistical significance (α=.05). Five variables consistently produced large, statistically significant effects (target applied load, cut length, starting rpm, diamond grit size, and cut type), while 4 variables produced relatively small, statistically insignificant effects (number of cooling ports, rotary cutting instrument diameter, disposability, and water flow rate). The control exerted by the dentist, simulated in this study by targeting a specific level of applied force, was the single most important factor affecting cutting efficiency. Cutting efficiency was also significantly affected by factors simulating patient/clinical circumstances as well as hardware choices. These results highlight the importance of local clinical conditions (procedure, dentist) in understanding dental cutting procedures and in designing adequate experimental methodologies for future studies. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

A conceptual design study for a two-dimensional, electronically scanned thinned array radiometer

NASA Technical Reports Server (NTRS)

Mutton, Philip; Chromik, Christopher C.; Dixon, Iain; Statham, Richard B.; Stillwagen, Frederic H.; Vontheumer, Alfred E.; Sasamoto, Washito A.; Garn, Paul A.; Cosgrove, Patrick A.; Ganoe, George G.

1993-01-01

A conceptual design for the Two-Dimensional, Electronically Steered Thinned Array Radiometer (ESTAR) is described. This instrument is a synthetic aperture microwave radiometer that operates in the L-band frequency range for the measurement of soil moisture and ocean salinity. Two auxiliary instruments, an 8-12 micron, scanning infrared radiometer and a 0.4-1.0 micron, charge coupled device (CCD) video camera, are included to provided data for sea surface temperature measurements and spatial registration of targets respectively. The science requirements were defined by Goddard Space Flight Center. Instrument and the spacecraft configurations are described for missions using the Pegasus and Taurus launch vehicles. The analyses and design trades described include: estimations of size, mass and power, instrument viewing coverage, mechanical design trades, structural and thermal analyses, data and communications performance assessments, and cost estimation.

Comparison of the Multiattribute Utility Instruments EQ-5D and SF-6D in a Europe-Wide Population-Based Cohort of Patients with Inflammatory Bowel Disease 10 Years after Diagnosis.

PubMed

Huppertz-Hauss, Gert; Aas, Eline; Lie Høivik, Marte; Langholz, Ebbe; Odes, Selwyn; Småstuen, Milada; Stockbrugger, Reinhold; Hoff, Geir; Moum, Bjørn; Bernklev, Tomm

2016-01-01

Background. The treatment of chronic inflammatory bowel disease (IBD) is costly, and limited resources call for analyses of the cost effectiveness of therapeutic interventions. The present study evaluated the equivalency of the Short Form 6D (SF-6D) and the Euro QoL (EQ-5D), two preference-based HRQoL instruments that are broadly used in cost-effectiveness analyses, in an unselected IBD patient population. Methods. IBD patients from seven European countries were invited to a follow-up visit ten years after their initial diagnosis. Clinical and demographic data were assessed, and the Short Form 36 (SF-36) was employed. Utility scores were obtained by calculating the SF-6D index values from the SF-36 data for comparison with the scores obtained with the EQ-5D questionnaire. Results. The SF-6D and EQ-5D provided good sensitivities for detecting disease activity-dependent utility differences. However, the single-measure intraclass correlation coefficient was 0.58, and the Bland-Altman plot indicated numerous values beyond the limits of agreement. Conclusions. There was poor agreement between the measures retrieved from the EQ-5D and the SF-6D utility instruments. Although both instruments may provide good sensitivity for the detection of disease activity-dependent utility differences, the instruments cannot be used interchangeably. Cost-utility analyses performed with only one utility instrument must be interpreted with caution.

Comparison of the Multiattribute Utility Instruments EQ-5D and SF-6D in a Europe-Wide Population-Based Cohort of Patients with Inflammatory Bowel Disease 10 Years after Diagnosis

PubMed Central

Aas, Eline; Odes, Selwyn; Småstuen, Milada; Stockbrugger, Reinhold; Hoff, Geir; Moum, Bjørn; Bernklev, Tomm

2016-01-01

Background. The treatment of chronic inflammatory bowel disease (IBD) is costly, and limited resources call for analyses of the cost effectiveness of therapeutic interventions. The present study evaluated the equivalency of the Short Form 6D (SF-6D) and the Euro QoL (EQ-5D), two preference-based HRQoL instruments that are broadly used in cost-effectiveness analyses, in an unselected IBD patient population. Methods. IBD patients from seven European countries were invited to a follow-up visit ten years after their initial diagnosis. Clinical and demographic data were assessed, and the Short Form 36 (SF-36) was employed. Utility scores were obtained by calculating the SF-6D index values from the SF-36 data for comparison with the scores obtained with the EQ-5D questionnaire. Results. The SF-6D and EQ-5D provided good sensitivities for detecting disease activity-dependent utility differences. However, the single-measure intraclass correlation coefficient was 0.58, and the Bland-Altman plot indicated numerous values beyond the limits of agreement. Conclusions. There was poor agreement between the measures retrieved from the EQ-5D and the SF-6D utility instruments. Although both instruments may provide good sensitivity for the detection of disease activity-dependent utility differences, the instruments cannot be used interchangeably. Cost-utility analyses performed with only one utility instrument must be interpreted with caution. PMID:27630711

Early meteorological records from Latin-America and the Caribbean during the 18th and 19th centuries

PubMed Central

Domínguez-Castro, Fernando; Vaquero, José Manuel; Gallego, María Cruz; Farrona, Ana María Marín; Antuña-Marrero, Juan Carlos; Cevallos, Erika Elizabeth; Herrera, Ricardo García; de la Guía, Cristina; Mejía, Raúl David; Naranjo, José Manuel; del Rosario Prieto, María; Ramos Guadalupe, Luis Enrique; Seiner, Lizardo; Trigo, Ricardo Machado; Villacís, Marcos

2017-01-01

This paper provides early instrumental data recovered for 20 countries of Latin-America and the Caribbean (Argentina, Bahamas, Belize, Brazil, British Guiana, Chile, Colombia, Costa Rica, Cuba, Ecuador, France (Martinique and Guadalupe), Guatemala, Jamaica, Mexico, Nicaragua, Panama, Peru, Puerto Rico, El Salvador and Suriname) during the 18th and 19th centuries. The main meteorological variables retrieved were air temperature, atmospheric pressure, and precipitation, but other variables, such as humidity, wind direction, and state of the sky were retrieved when possible. In total, more than 300,000 early instrumental data were rescued (96% with daily resolution). Especial effort was made to document all the available metadata in order to allow further post-processing. The compilation is far from being exhaustive, but the dataset will contribute to a better understanding of climate variability in the region, and to enlarging the period of overlap between instrumental data and natural/documentary proxies. PMID:29135974

Investigation on Motorcyclist Riding Behaviour at Curve Entry Using Instrumented Motorcycle

PubMed Central

Yuen, Choon Wah; Karim, Mohamed Rehan; Saifizul, Ahmad

2014-01-01

This paper details the study on the changes in riding behaviour, such as changes in speed as well as the brake force and throttle force applied, when motorcyclists ride over a curve section road using an instrumented motorcycle. In this study, an instrumented motorcycle equipped with various types of sensors, on-board cameras, and data loggers, was developed in order to collect the riding data on the study site. Results from the statistical analysis showed that riding characteristics, such as changes in speed, brake force, and throttle force applied, are influenced by the distance from the curve entry, riding experience, and travel mileage of the riders. A structural equation modeling was used to study the impact of these variables on the change of riding behaviour in curve entry section. Four regression equations are formed to study the relationship between four dependent variables, which are speed, throttle force, front brake force, and rear brake force applied with the independent variables. PMID:24523660

Developing a historical climatology of Wales from Welsh and English language sources

NASA Astrophysics Data System (ADS)

MacDonald, N.; Davies, S. J.; Jones, C. A.; Charnell-White, C.

2009-04-01

Historical documentary records are recognised as valuable in understanding long term climate variability. In the UK, the Central England Temperature Series (1772- ) and the Lamb weather catalogue (1861- ) provide a detailed climate record for England, but the value of these archives in Wales and Scotland is more limited, though some long term instrumental series exist, particularly for cities such as Cardiff. The spatial distance from the central England area and a lower density of instrumental stations in Wales has limited understanding of climate variability during the instrumental period (~1750- ). This paper illustrates that historical documentary records represent a considerable resource, that to date have been underutilised in developing a more complete understanding of past weather and climate within many parts of Western Europe.

Medical decision-making capacity in patients with malignant glioma.

PubMed

Triebel, Kristen L; Martin, Roy C; Nabors, Louis B; Marson, Daniel C

2009-12-15

Patients with malignant glioma (MG) must make ongoing medical treatment decisions concerning a progressive disease that erodes cognition. We prospectively assessed medical decision-making capacity (MDC) in patients with MG using a standardized psychometric instrument. Participants were 22 healthy controls and 26 patients with histologically verified MG. Group performance was compared on the Capacity to Consent to Treatment Instrument (CCTI), a psychometric measure of MDC incorporating 4 standards (choice, understanding, reasoning, and appreciation), and on neuropsychological and demographic variables. Capacity outcomes (capable, marginally capable, or incapable) on the CCTI standards were identified for the MG group. Within the MG group, scores on demographic, clinical, and neuropsychological variables were correlated with scores on each CCTI standard, and significant bivariate correlates were subsequently entered into exploratory stepwise regression analyses to identify multivariate cognitive predictors of the CCTI standards. Patients with MG performed significantly below controls on consent standards of understanding and reasoning, and showed a trend on appreciation. Relative to controls, more than 50% of the patients with MG demonstrated capacity compromise (marginally capable or incapable outcomes) in MDC. In the MG group, cognitive measures of verbal acquisition/recall and, to a lesser extent, semantic fluency predicted performance on the appreciation, reasoning, and understanding standards. Karnofsky score was also associated with CCTI performance. Soon after diagnosis, patients with malignant glioma (MG) have impaired capacity to make treatment decisions relative to controls. Medical decision-making capacity (MDC) impairment in MG seems to be primarily related to the effects of short-term verbal memory deficits. Ongoing assessment of MDC in patients with MG is strongly recommended.

Determination of arsenic, cadmium, cobalt, chromium, lead, molybdenum, nickel, and selenium in fertilizers by microwave digestion and inductively coupled plasma-optical emission spectrometry detection: collaborative study.

PubMed

Kane, Peter F; Hall, William L

2006-01-01

There is increasing regulatory interest in the non-nutritive metals content of fertilizer materials, but at present there is no consensus analytical method for acid digestion and instrument detection of those elements in fertilizer matrixes. This lack of method standardization has resulted in unacceptable variability of results between fertilizer laboratories performing metals analysis. A method has been developed using microwave digestion with nitric acid at 200 degrees C, followed by inductively coupled plasma-optical emission spectrometry instrument detection, for the elements arsenic, cadmium, cobalt, chromium, molybdenum, nickel, lead, and selenium. The method has been collaboratively studied, and statistical results are here reported. Fourteen collaborators were sent 62 sample materials in a blind duplicate design. Materials represented a broad cross section of fertilizer types, including phosphate ore, manufactured phosphate products, N-P-K blends, organic fertilizers, and micro-nutrient materials. As much as possible within the limit of the number of samples, materials were selected from different regions of the United States and the world. Limit of detection (LOD) was determined using synthetic fertilizers consisting of reagent grade chemicals with near zero levels of the non-nutritive elements, analyzed blindly. Samples with high iron content caused the most variability between laboratories. Most samples reasonably above LOD gave HorRat values within the range 0.5 to 2.0, indicating acceptable method performance according to AOAC guidelines for analyses in the mg/kg range. The method is recommended for AOAC Official First Action status.

Snowpack variations since AD 1150 in the Andes of Chile and Argentina (30°-37°S) inferred from rainfall, tree-ring and documentary records

NASA Astrophysics Data System (ADS)

Masiokas, M. H.; Villalba, R.; Christie, D. A.; Betman, E.; Luckman, B. H.; Le Quesne, C.; Prieto, M. R.; Mauget, S.

2012-03-01

The Andean snowpack is the main source of freshwater and arguably the single most important natural resource for the populated, semi-arid regions of central Chile and central-western Argentina. However, apart from recent analyses of instrumental snowpack data, very little is known about the long term variability of this key natural resource. Here we present two complementary, annually-resolved reconstructions of winter snow accumulation in the southern Andes between 30°-37°S. The reconstructions cover the past 850 years and were developed using simple regression models based on snowpack proxies with different inherent limitations. Rainfall data from central Chile (very strongly correlated with snow accumulation values in the adjacent mountains) were used to extend a regional 1951-2010 snowpack record back to AD 1866. Subsequently, snow accumulation variations since AD 1150 were inferred from precipitation-sensitive tree-ring width series. The reconstructed snowpack values were validated with independent historical and instrumental information. An innovative time series analysis approach allowed the identification of the onset, duration and statistical significance of the main intra- to multi-decadal patterns in the reconstructions and indicates that variations observed in the last 60 years are not particularly anomalous when assessed in a multi-century context. In addition to providing new information on past variations for a highly relevant hydroclimatic variable in the southern Andes, the snowpack reconstructions can also be used to improve the understanding and modeling of related, larger-scale atmospheric features such as ENSO and the PDO.

Factors Influencing Physical Activity Behavior among Iranian Women with Type 2 Diabetes Using the Extended Theory of Reasoned Action.

PubMed

Didarloo, Alireza; Shojaeizadeh, Davoud; Ardebili, Hassan Eftekhar; Niknami, Shamsaddin; Hajizadeh, Ebrahim; Alizadeh, Mohammad

2011-10-01

Findings of most studies indicate that the only way to control diabetes and prevent its debilitating effects is through the continuous performance of self-care behaviors. Physical activity is a non-pharmacological method of diabetes treatment and because of its positive effects on diabetic patients, it is being increasingly considered by researchers and practitioners. This study aimed at determining factors influencing physical activity among diabetic women in Iran, using the extended theory of reasoned action in Iran. A sample of 352 women with type 2 diabetes, referring to a Diabetes Clinic in Khoy, Iran, participated in the study. Appropriate instruments were designed to measure the desired variables (knowledge of diabetes, personal beliefs, subjective norms, perceived self-efficacy, behavioral intention and physical activity behavior). The reliability and validity of the instruments were examined and approved. Statistical analyses of the study were conducted by inferential statistical techniques (independent t-test, correlations and regressions) using the SPSS package. The findings of this investigation indicated that among the constructs of the model, self efficacy was the strongest predictor of intentions among women with type 2 diabetes and both directly and indirectly affected physical activity. In addition to self efficacy, diabetic patients' physical activity also was influenced by other variables of the model and sociodemographic factors. Our findings suggest that the high ability of the theory of reasoned action extended by self-efficacy in forecasting and explaining physical activity can be a base for educational intervention. Educational interventions based on the proposed model are necessary for improving diabetics' physical activity behavior and controlling disease.

Adverse childhood experiences and later life adult obesity and smoking in the United States.

PubMed

Rehkopf, David H; Headen, Irene; Hubbard, Alan; Deardorff, Julianna; Kesavan, Yamini; Cohen, Alison K; Patil, Divya; Ritchie, Lorrene D; Abrams, Barbara

2016-07-01

Prior work demonstrates associations between physical abuse, household alcohol abuse, and household mental illness early in life with obesity and smoking. Studies, however, have not generally been in nationally representative samples and have not conducted analyses to account for bias in the exposure. We used data from the 1979 U.S. National Longitudinal Survey of Youth to test associations between measures of adverse childhood experiences with obesity and smoking and used an instrumental variables approach to address potential measurement error of the exposure. Models demonstrated associations between childhood physical abuse and obesity at age 40 years (odds ratio [OR] 1.23; 95% confidence interval [CI], 1.00-1.52) and ever smoking (OR 1.83; 95% CI, 1.56-2.16), as well as associations between household alcohol abuse (OR 1.53; 95% CI, 1.31-1.79) and household mental illness (OR 1.29; 95% CI, 1.04-1.60) with ever smoking. We find no evidence of association modification by gender, socioeconomic position, or race and/or ethnicity. Instrumental variables analysis using a sibling's report of adverse childhood experiences demonstrated a relationship between household alcohol abuse and smoking, with a population attributable fraction of 17% (95% CI, 2.0%-37%) for ever smoking and 6.7% (95% CI, 1.6%-12%) for currently smoking. Findings suggest long-term impacts of childhood exposure to physical abuse, household alcohol abuse, and parental mental illness on obesity and smoking and that the association between household alcohol abuse and smoking is not solely due to measurement error. Copyright © 2016 Elsevier Inc. All rights reserved.

Measurement of Impact Acceleration: Mouthpiece Accelerometer Versus Helmet Accelerometer

PubMed Central

Higgins, Michael; Halstead, P. David; Snyder-Mackler, Lynn; Barlow, David

2007-01-01

Context: Instrumented helmets have been used to estimate impact acceleration imparted to the head during helmet impacts. These instrumented helmets may not accurately measure the actual amount of acceleration experienced by the head due to factors such as helmet-to-head fit. Objective: To determine if an accelerometer attached to a mouthpiece (MP) provides a more accurate representation of headform center of gravity (HFCOG) acceleration during impact than does an accelerometer attached to a helmet fitted on the headform. Design: Single-factor research design in which the independent variable was accelerometer position (HFCOG, helmet, MP) and the dependent variables were g and Severity Index (SI). Setting: Independent impact research laboratory. Intervention(s): The helmeted headform was dropped (n = 168) using a National Operating Committee on Standards for Athletic Equipment (NOCSAE) drop system from the standard heights and impact sites according to NOCSAE test standards. Peak g and SI were measured for each accelerometer position during impact. Main Outcome Measures: Upon impact, the peak g and SI were recorded for each accelerometer location. Results: Strong relationships were noted for HFCOG and MP measures, and significant differences were seen between HFCOG and helmet g measures and HFCOG and helmet SI measures. No statistically significant differences were noted between HFCOG and MP g and SI measures. Regression analyses showed a significant relationship between HFCOG and MP measures but not between HFCOG and helmet measures. Conclusions: Upon impact, MP acceleration (g) and SI measurements were closely related to and more accurate in measuring HFCOG g and SI than helmet measurements. The MP accelerometer is a valid method for measuring head acceleration. PMID:17597937

Drought events in the Czech Republic: past, present, future

NASA Astrophysics Data System (ADS)

Brázdil, Rudolf; Trnka, Miroslav; Mikšovský, Jiří; Tolasz, Radim; Dobrovolný, Petr; Řezníčková, Ladislava; Dolák, Lukáš

2017-04-01

Droughts are, together with floods, the most important natural extremes in the Czech Republic. In the last c. 20 years even some irregular alternations of years with severe droughts on the one hand (2000, 2003, 2007, 2011-2012, 2014-2015) and severe floods on the other (1997, 1998, 2002, 2005, 2009, 2010, 2013), reflecting greater variability of the water cycle, can be observed. Great attention devoted to the study of past, present and future of droughts in the Czech Republic in a few last years allowed to obtain basic knowledge related to long-term spatial-temporal variability of droughts, combining dendrochronological, documentary and instrumental data, synoptic causes and climate forcings of droughts, case studies of important drought anomalies with significant social-economic consequences (like drought of 1947), impacts of droughts in agriculture, forestry or water management, and future droughts according to model estimates. Basic results obtained are summarised and documented by several typical examples. Such level of drought knowledge became a basis for formulation of the new research project, trying to analyse the climate forcings and triggers involved in the occurrence, course and severity of drought events in the Czech Republic in the context of Central Europe and explanations of their physical mechanisms, based on a 515-year series of drought indices reconstructed from documentary and instrumental data. Presentation of this new project for 2017-2019 is included in the second part of the paper. (This work was supported by Czech Science Foundation, project no. 17-10026S "Drought events in the Czech Republic and their causes".)

Extreme Response Style and the Measurement of Intra-Individual Variability

ERIC Educational Resources Information Center

Deng, Sien

2017-01-01

Psychologists have become increasingly interested in the intra-individual variability of psychological measures as a meaningful distinguishing characteristic of persons. Assessments of intra-individual variability are frequently based on the repeated administration of self-report rating scale instruments, and extreme response style (ERS) has the…

The individualistic fallacy, ecological studies and instrumental variables: a causal interpretation.

PubMed

Loney, Tom; Nagelkerke, Nico J

2014-01-01

The validity of ecological studies in epidemiology for inferring causal relationships has been widely challenged as observed associations could be biased by the Ecological Fallacy. We reconsider the important design components of ecological studies, and discuss the conditions that may lead to spurious associations. Ecological associations are useful and valid when the ecological exposures can be interpreted as Instrumental Variables. A suitable example may be a time series analysis of environmental pollution (e.g. particulate matter with an aerodynamic diameter of <10 micrometres; PM10) and health outcomes (e.g. hospital admissions for acute myocardial infarction) as environmental pollution levels are a cause of individual exposure levels and not just an aggregate measurement. Ecological exposures may also be employed in situations (perhaps rare) where individual exposures are known but their associations with health outcomes are confounded by unknown or unquantifiable factors. Ecological associations have a notorious reputation in epidemiology and individualistic associations are considered superior to ecological associations because of the "ecological fallacy". We have argued that this is incorrect in situations in which ecological or aggregate exposures can serve as an instrumental variable and associations between individual exposure and outcome are likely to be confounded by unmeasured variables.

Employment insecurity and employees' health in Denmark.

PubMed

Cottini, Elena; Ghinetti, Paolo

2018-02-01

We use register data for Denmark (IDA) merged with the Danish Work Environment Cohort Survey (1995, 2000, and 2005) to estimate the effect of perceived employment insecurity on perceived health for a sample of Danish employees. We consider two health measures from the SF-36 Health Survey Instrument: a vitality scale for general well-being and a mental health scale. We first analyse a summary measure of employment insecurity. Instrumental variables-fixed effects estimates that use firm workforce changes as a source of exogenous variation show that 1 additional dimension of insecurity causes a shift from the median to the 25th percentile in the mental health scale and to the 30th in that of energy/vitality. It also increases by about 6 percentage points the probability to develop severe mental health problems. Looking at single insecurity dimensions by naïve fixed effects, uncertainty associated with the current job is important for mental health. Employability has a sizeable relationship with health and is the only insecurity dimension that matters for the energy and vitality scale. Danish employees who fear involuntary firm internal mobility experience worse mental health. Copyright © 2017 John Wiley & Sons, Ltd.

Insurance disruption due to spousal Medicare transitions: implications for access to care and health care utilization for women approaching age 65.

PubMed

Schumacher, Jessica R; Smith, Maureen A; Liou, Jinn-Ing; Pandhi, Nancy

2009-06-01

To assess whether a husband's Medicare transition leads to insurance disruptions for his wife that impact her perceived access to care, health care utilization, or health status. Respondents were married women under age 65 from the 2003-2005 round of the Wisconsin Longitudinal Study (N=655). Instrumental variable (IV) linear and IV-probit analyses provided unbiased estimates of the effect of an insurance disruption on study outcomes. The instrument was the husband's age: (1) women with husbands who transitioned to Medicare within the previous year (age 65-66); (2) women with husbands who did not transition (60

Meta-Analysis of Inquiry-Based Instruction Research

NASA Astrophysics Data System (ADS)

Hasanah, N.; Prasetyo, A. P. B.; Rudyatmi, E.

2017-04-01

Inquiry-based instruction in biology has been the focus of educational research conducted by Unnes biology department students in collaboration with their university supervisors. This study aimed to describe the methodological aspects, inquiry teaching methods critically, and to analyse the results claims, of the selected four student research reports, grounded in inquiry, based on the database of Unnes biology department 2014. Four experimental quantitative research of 16 were selected as research objects by purposive sampling technique. Data collected through documentation study was qualitatively analysed regarding methods used, quality of inquiry syntax, and finding claims. Findings showed that the student research was still the lack of relevant aspects of research methodology, namely in appropriate sampling procedures, limited validity tests of all research instruments, and the limited parametric statistic (t-test) not supported previously by data normality tests. Their consistent inquiry syntax supported the four mini-thesis claims that inquiry-based teaching influenced their dependent variables significantly. In other words, the findings indicated that positive claims of the research results were not fully supported by good research methods, and well-defined inquiry procedures implementation.

Combining fixed effects and instrumental variable approaches for estimating the effect of psychosocial job quality on mental health: evidence from 13 waves of a nationally representative cohort study.

PubMed

Milner, Allison; Aitken, Zoe; Kavanagh, Anne; LaMontagne, Anthony D; Pega, Frank; Petrie, Dennis

2017-06-23

Previous studies suggest that poor psychosocial job quality is a risk factor for mental health problems, but they use conventional regression analytic methods that cannot rule out reverse causation, unmeasured time-invariant confounding and reporting bias. This study combines two quasi-experimental approaches to improve causal inference by better accounting for these biases: (i) linear fixed effects regression analysis and (ii) linear instrumental variable analysis. We extract 13 annual waves of national cohort data including 13 260 working-age (18-64 years) employees. The exposure variable is self-reported level of psychosocial job quality. The instruments used are two common workplace entitlements. The outcome variable is the Mental Health Inventory (MHI-5). We adjust for measured time-varying confounders. In the fixed effects regression analysis adjusted for time-varying confounders, a 1-point increase in psychosocial job quality is associated with a 1.28-point improvement in mental health on the MHI-5 scale (95% CI: 1.17, 1.40; P < 0.001). When the fixed effects was combined with the instrumental variable analysis, a 1-point increase psychosocial job quality is related to 1.62-point improvement on the MHI-5 scale (95% CI: -0.24, 3.48; P = 0.088). Our quasi-experimental results provide evidence to confirm job stressors as risk factors for mental ill health using methods that improve causal inference. © The Author 2017. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Influence of therapist competence and quantity of cognitive behavioural therapy on suicidal behaviour and inpatient hospitalisation in a randomised controlled trial in borderline personality disorder: Further analyses of treatment effects in the BOSCOT study

PubMed Central

Norrie, John; Davidson, Kate; Tata, Philip; Gumley, Andrew

2013-01-01

Objectives We investigated the treatment effects reported from a high-quality randomized controlled trial of cognitive behavioural therapy (CBT) for 106 people with borderline personality disorder attending community-based clinics in the UK National Health Service – the BOSCOT trial. Specifically, we examined whether the amount of therapy and therapist competence had an impact on our primary outcome, the number of suicidal acts†, using instrumental variables regression modelling. Design Randomized controlled trial. Participants from across three sites (London, Glasgow, and Ayrshire/Arran) were randomized equally to CBT for personality disorders (CBTpd) plus Treatment as Usual or to Treatment as Usual. Treatment as Usual varied between sites and individuals, but was consistent with routine treatment in the UK National Health Service at the time. CBTpd comprised an average 16 sessions (range 0–35) over 12 months. Method We used instrumental variable regression modelling to estimate the impact of quantity and quality of therapy received (recording activities and behaviours that took place after randomization) on number of suicidal acts and inpatient psychiatric hospitalization. Results A total of 101 participants provided full outcome data at 2 years post randomization. The previously reported intention-to-treat (ITT) results showed on average a reduction of 0.91 (95% confidence interval 0.15–1.67) suicidal acts over 2 years for those randomized to CBT. By incorporating the influence of quantity of therapy and therapist competence, we show that this estimate of the effect of CBTpd could be approximately two to three times greater for those receiving the right amount of therapy from a competent therapist. Conclusions Trials should routinely control for and collect data on both quantity of therapy and therapist competence, which can be used, via instrumental variable regression modelling, to estimate treatment effects for optimal delivery of therapy. Such estimates complement rather than replace the ITT results, which are properly the principal analysis results from such trials. Practitioner points Assessing the impact of the quantity and quality of therapy (competence of therapists) is complex. More competent therapists, trained in CBTpd, may significantly reduce the number of suicidal act in patients with borderline personality disorder. PMID:23420622

Does High Tobacco Consumption Cause Psychological Distress? A Mendelian Randomization Study.

PubMed

Skov-Ettrup, Lise S; Nordestgaard, Børge G; Petersen, Christina B; Tolstrup, Janne S

2017-01-01

Increasing evidence suggests that smoking influences mental health negatively. This study investigated whether high tobacco consumption is causally related to psychological distress in a Mendelian randomization design, using a variant in the nicotine acetylcholine receptor gene CHRNA3-known to influence individual tobacco consumption-as instrumental variable for tobacco consumption. Data from 90 108 participants in the Copenhagen General Population Study was used. Exposures included self-reported cigarettes/day and pack years and the CHRNA3 rs1051730 genotype as instrumental variable for tobacco consumption. Three dimensions of psychological distress were studied: Stress, fatigue, and hopelessness. Analyses with the CHRNA3 genotype were stratified by smoking status. Self-reported amount of smoking was associated with all three dimensions of psychological distress. For instance among participants smoking 30 cigarettes/day or more, the odds ratio (OR) for stress was 1.67 (95% confidence interval [CI] 1.47-1.89) compared to never-smokers. Corresponding ORs for fatigue and hopelessness were 2.18 (95% CI 1.92-2.47) and 3.08 (95% CI 2.62-3.62). Among current smokers, homozygotes and heterozygotes for the CHRNA3 genotype had higher tobacco consumption than noncarriers. Nevertheless, the CHRNA3 genotype was not associated with psychological distress neither in current nor in former or never-smokers. For instance among current smokers, the OR for stress was 1.02 (95% CI 0.91-1.15) among homozygotes compared to noncarriers of the CHRNA3 genotype. Though a strong association between tobacco consumption and psychological distress was found, there was no clear evidence that high tobacco consumption was causally related to psychological distress. Smoking is associated with several mental health outcomes and smoking cessation is associated with improved mental health. Causality in the association between smoking and mental health is difficult to establish using observational data. Using a genotype known to influence tobacco consumption as instrumental variable for amount of smoking, we found no clear evidence of a direct causal path between high tobacco consumption and psychological distress. Whatever causes the strong association between tobacco consumption and psychological distress, the co-occurrence is important to consider both in interventions for smoking prevention and cessation. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Single-breath diffusing capacity for carbon monoxide instrument accuracy across 3 health systems.

PubMed

Hegewald, Matthew J; Markewitz, Boaz A; Wilson, Emily L; Gallo, Heather M; Jensen, Robert L

2015-03-01

Measuring diffusing capacity of the lung for carbon monoxide (DLCO) is complex and associated with wide intra- and inter-laboratory variability. Increased D(LCO) variability may have important clinical consequences. The objective of the study was to assess instrument performance across hospital pulmonary function testing laboratories using a D(LCO) simulator that produces precise and repeatable D(LCO) values. D(LCO) instruments were tested with CO gas concentrations representing medium and high range D(LCO) values. The absolute difference between observed and target D(LCO) value was used to determine measurement accuracy; accuracy was defined as an average deviation from the target value of < 2.0 mL/min/mm Hg. Accuracy of inspired volume measurement and gas sensors were also determined. Twenty-three instruments were tested across 3 healthcare systems. The mean absolute deviation from the target value was 1.80 mL/min/mm Hg (range 0.24-4.23) with 10 of 23 instruments (43%) being inaccurate. High volume laboratories performed better than low volume laboratories, although the difference was not significant. There was no significant difference among the instruments by manufacturers. Inspired volume was not accurate in 48% of devices; mean absolute deviation from target value was 3.7%. Instrument gas analyzers performed adequately in all instruments. D(LCO) instrument accuracy was unacceptable in 43% of devices. Instrument inaccuracy can be primarily attributed to errors in inspired volume measurement and not gas analyzer performance. D(LCO) instrument performance may be improved by regular testing with a simulator. Caution should be used when comparing D(LCO) results reported from different laboratories. Copyright © 2015 by Daedalus Enterprises.

Evaluating the performance of commonly used gas analysers for methane eddy covariance flux measurements: the InGOS inter-comparison field experiment

NASA Astrophysics Data System (ADS)

Peltola, O.; Hensen, A.; Helfter, C.; Belelli Marchesini, L.; Bosveld, F. C.; van den Bulk, W. C. M.; Elbers, J. A.; Haapanala, S.; Holst, J.; Laurila, T.; Lindroth, A.; Nemitz, E.; Röckmann, T.; Vermeulen, A. T.; Mammarella, I.

2014-01-01

The performance of eight fast-response methane (CH4) gas analysers suitable for eddy covariance flux measurements were tested at a grassland site near the Cabauw tall tower (Netherlands) during June 2012. The instruments were positioned close to each other in order to minimize the effect of varying turbulent conditions. The moderate CH4 fluxes observed at the location, of the order of 25 nmol m-2 s-1, provided a suitable signal for testing the instruments' performance. Generally, all analysers tested were able to quantify the concentration fluctuations at the frequency range relevant for turbulent exchange and were able to deliver high-quality data. The tested cavity ring-down spectrometer (CRDS) instruments from Picarro, models G2311-f and G1301-f, were superior to other CH4 analysers with respect to instrumental noise. As an open-path instrument susceptible to the effects of rain, the LI-COR LI-7700 achieved lower data coverage and also required larger density corrections; however, the system is especially useful for remote sites that are restricted in power availability. In this study the open-path LI-7700 results were compromised due to a data acquisition problem in our data-logging setup. Some of the older closed-path analysers tested do not measure H2O vapour concentrations alongside CH4 (i.e. FMA1 and DLT-100 by Los Gatos Research) and this complicates data processing since the required corrections for dilution and spectroscopic interactions have to be based on external information. To overcome this issue, we used H2O mole fractions measured by other gas analysers, adjusted them with different methods and then applied them to correct the CH4 fluxes. Following this procedure we estimated a bias on the order of 0.1 g (CH4) m-2 (8% of the measured mean flux) in the processed and corrected CH4 fluxes on a monthly scale due to missing H2O concentration measurements. Finally, cumulative CH4 fluxes over 14 days from three closed-path gas analysers, G2311-f (Picarro Inc.), FGGA (Los Gatos Research) and FMA2 (Los Gatos Research), which were measuring H2O vapour concentrations in addition to CH4, agreed within 3% (355-367 mg (CH4) m-2) and were not clearly different from each other, whereas the other instruments derived total fluxes which showed small but distinct differences (±10%, 330-399 mg (CH4) m-2).

Evaluating the performance of commonly used gas analysers for methane eddy covariance flux measurements: the InGOS inter-comparison field experiment

NASA Astrophysics Data System (ADS)

Peltola, O.; Hensen, A.; Helfter, C.; Belelli Marchesini, L.; Bosveld, F. C.; van den Bulk, W. C. M.; Elbers, J. A.; Haapanala, S.; Holst, J.; Laurila, T.; Lindroth, A.; Nemitz, E.; Röckmann, T.; Vermeulen, A. T.; Mammarella, I.

2014-06-01

The performance of eight fast-response methane (CH4) gas analysers suitable for eddy covariance flux measurements were tested at a grassland site near the Cabauw tall tower (Netherlands) during June 2012. The instruments were positioned close to each other in order to minimise the effect of varying turbulent conditions. The moderate CH4 fluxes observed at the location, of the order of 25 nmol m-2 s-1, provided a suitable signal for testing the instruments' performance. Generally, all analysers tested were able to quantify the concentration fluctuations at the frequency range relevant for turbulent exchange and were able to deliver high-quality data. The tested cavity ringdown spectrometer (CRDS) instruments from Picarro, models G2311-f and G1301-f, were superior to other CH4 analysers with respect to instrumental noise. As an open-path instrument susceptible to the effects of rain, the LI-COR LI-7700 achieved lower data coverage and also required larger density corrections; however, the system is especially useful for remote sites that are restricted in power availability. In this study the open-path LI-7700 results were compromised due to a data acquisition problem in our data-logging setup. Some of the older closed-path analysers tested do not measure H2O concentrations alongside CH4 (i.e. FMA1 and DLT-100 by Los Gatos Research) and this complicates data processing since the required corrections for dilution and spectroscopic interactions have to be based on external information. To overcome this issue, we used H2O mole fractions measured by other gas analysers, adjusted them with different methods and then applied them to correct the CH4 fluxes. Following this procedure we estimated a bias of the order of 0.1 g (CH4) m-2 (8% of the measured mean flux) in the processed and corrected CH4 fluxes on a monthly scale due to missing H2O concentration measurements. Finally, cumulative CH4 fluxes over 14 days from three closed-path gas analysers, G2311-f (Picarro Inc.), FGGA (Los Gatos Research) and FMA2 (Los Gatos Research), which were measuring H2O concentrations in addition to CH4, agreed within 3% (355-367 mg (CH4) m-2) and were not clearly different from each other, whereas the other instruments derived total fluxes which showed small but distinct differences (±10%, 330-399 mg (CH4) m-2).

Comparison between Pludix and impact/optical disdrometers during rainfall measurement campaigns

NASA Astrophysics Data System (ADS)

Caracciolo, Clelia; Prodi, Franco; Uijlenhoet, Remko

2006-11-01

The performances of two couples of disdrometers based on different measuring principles are compared: a classical Joss-Waldvogel disdrometer and a recently developed device, called the Pludix tested in Ferrara, Italy, and Pludix and the two-dimensional video disdrometer (2DVD) tested in Cabauw, The Netherlands. First, the measuring principles of the different instruments are presented and compared. Secondly, the performances of the two pairs of disdrometers are analysed by comparing their rain amounts with nearby tipping bucket rain gauges and the inferred drop size distributions. The most important rainfall integral parameters (e.g. rain rate and radar reflectivity) and drop size distribution parameters are also analysed and compared. The data set for Ferrara comprises 13 rainfall events, with a total of 20 mm of rainfall and a maximum rain rate of 4 mm h - 1 . The data set for Cabauw consists of 9 events, with 25-50 mm of rainfall and a maximum rain rate of 20-40 mm h - 1 . The Pludix tends to underestimate slightly the bulk rainfall variables in less intense events, whereas it tends to overestimate with respect to the other instruments in heavier events. The correspondence of the inferred drop size distributions with those measured by the other disdrometers is reasonable, particularly with the Joss-Waldvogel disdrometer. Considering that the Pludix is still in a calibration and testing phase, the reported results are encouraging. A new signal inversion algorithm, which will allow the detection of rain drops throughout the entire diameter interval between 0.3 and 7.0 mm, is under development.

Building a QC Database of Meteorological Data from NASA KSC and the United States Air Force's Eastern Range

NASA Technical Reports Server (NTRS)

Brenton, J. C.; Barbre, R. E.; Decker, R. K.; Orcutt, J. M.

2018-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) Natural Environments Branch (EV44) provides atmospheric databases and analysis in support of space vehicle design and day-of-launch operations for NASA and commercial launch vehicle programs launching from the NASA Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station. The ER complex is one of the most heavily instrumented sites in the United States with over 31 towers measuring various atmospheric parameters on a continuous basis. An inherent challenge with large datasets consists of ensuring erroneous data are removed from databases, and thus excluded from launch vehicle design analyses. EV44 has put forth great effort in developing quality control (QC) procedures for individual meteorological instruments, however no standard QC procedures for all databases currently exists resulting in QC databases that have inconsistencies in variables, development methodologies, and periods of record. The goal of this activity is to use the previous efforts to develop a standardized set of QC procedures from which to build meteorological databases from KSC and the ER, while maintaining open communication with end users from the launch community to develop ways to improve, adapt and grow the QC database. Details of the QC procedures will be described. As the rate of launches increases with additional launch vehicle programs, It is becoming more important that weather databases are continually updated and checked for data quality before use in launch vehicle design and certification analyses.

The Pathological Buying Screener: Development and Psychometric Properties of a New Screening Instrument for the Assessment of Pathological Buying Symptoms

PubMed Central

Trotzke, Patrick; Mitchell, James E.; de Zwaan, Martina

2015-01-01

The study was designed to develop a new screening instrument for pathological buying (PB), and to examine its psychometric properties in a large-scale sample. By using a facet theoretical approach and based on literature as well as on clinical experience, a 20-item Pathological Buying Screener (PBS) was developed and administered to a representative German sample (n = 2,539). Valid data were available from 2,403 participants who were subjects for three subsequent empirical studies. The first study explored the factor structure using exploratory factor analyses in a subsample of 498 participants. Based on factor loadings, a 13-item version with the two factors loss of control / consequences and excessive buying behavior was revealed. This two-factor model was confirmed in study 2 by confirmatory factor analysis performed on another subsample (n = 1,905). Study 3 investigated age and gender effects and convergent validity of the PBS using the Compulsive Buying Scale (CBS) in the full sample (N = 2,403). The total PBS score was adequately correlated with the CBS score. Hierarchical regression analyses with the CBS score as the dependent variable and the two PBS factors as the predictors indicated an own incremental validity of the two factors in participants ≤ 65 years. The reliability of the total score as well as of the two subscales was good to excellent. Overall, the PBS represents a useful measure for PB. Future studies are needed to replicate the two-factor structure in clinical samples and to define a valid cutoff for PB. PMID:26488872

The Pathological Buying Screener: Development and Psychometric Properties of a New Screening Instrument for the Assessment of Pathological Buying Symptoms.

PubMed

Müller, Astrid; Trotzke, Patrick; Mitchell, James E; de Zwaan, Martina; Brand, Matthias

2015-01-01

The study was designed to develop a new screening instrument for pathological buying (PB), and to examine its psychometric properties in a large-scale sample. By using a facet theoretical approach and based on literature as well as on clinical experience, a 20-item Pathological Buying Screener (PBS) was developed and administered to a representative German sample (n = 2,539). Valid data were available from 2,403 participants who were subjects for three subsequent empirical studies. The first study explored the factor structure using exploratory factor analyses in a subsample of 498 participants. Based on factor loadings, a 13-item version with the two factors loss of control / consequences and excessive buying behavior was revealed. This two-factor model was confirmed in study 2 by confirmatory factor analysis performed on another subsample (n = 1,905). Study 3 investigated age and gender effects and convergent validity of the PBS using the Compulsive Buying Scale (CBS) in the full sample (N = 2,403). The total PBS score was adequately correlated with the CBS score. Hierarchical regression analyses with the CBS score as the dependent variable and the two PBS factors as the predictors indicated an own incremental validity of the two factors in participants ≤ 65 years. The reliability of the total score as well as of the two subscales was good to excellent. Overall, the PBS represents a useful measure for PB. Future studies are needed to replicate the two-factor structure in clinical samples and to define a valid cutoff for PB.

Two in one: making electron and ion measurements using a single MCP in future top hat instruments.

NASA Astrophysics Data System (ADS)

Bedington, Robert; Saito, Yoshifumi

To allow for the reduced use of spacecraft resources in future missions, we are developing techniques to enable both electrons and ions to be measured in a single top hat instrument. Top hat energy analyser instruments typically analyse charged particles from a few eV to a few tens keV. They consist of an electrostatic, energy-analyser section and a detector. MCPs (micro-channel plates) are the most commonly used detectors, because of their high sensitivity and strong heritage in space instrumentation. To detect the lowest energies of charged particles, a pre-accelerating bias potential is applied to the front surface of the MCP, however this voltage cannot be altered quickly without drastically affecting the detector response. Any instrument that detects both electrons and ions, will therefore typically use two detectors (with fixed voltages)—one for electrons, one for ions, and will often use two separate energy analysers. Significant resource savings are available however if just a single MCP can be used. This can be achieved by having incoming ions (and optionally incoming electrons also) impact a secondary electron emitting material, and thus release secondary electrons to be detected by a positively biased (electron-detecting) MCP. Unlike MCPs, the electrostatic, energy-analyser sections are able to have their voltages cycled extremely rapidly, so that they can be made to sample electrons and then ions in quick succession with minimal design changes required. Two secondary electron conversion methods are being investigated: ultra-thin carbon foils, and dynodes. Using carbon foils in front of the MCPs, incoming ions can be detected by the secondary electrons they release, while incoming electrons pass straight through them. Using dynodes all incoming particles can be converted to secondary electrons before detection. The challenges include finding materials with uniform electron emission responses for the desired energies and particles, managing electric fields and scattered primary electrons. Experiments pertaining to this research will be discussed. These investigations are being pursued as prototype developments for the SCOPE mission for use on the EISA (Electron & Ion Spectrum Analyzer) instrument.

Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO)

NASA Technical Reports Server (NTRS)

McCormick, M. Patrick; Winker, David M.

1998-01-01

This paper will describe the planned 3-year Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO) mission, its instrumentation and implementation. It will use LITE and other data, plus analyses, to show the feasibility of such a mission. PICASSO is being proposed for NASA's Earth System Science Pathfinder (ESSP) program with launch predicted in 2003.

Variables Affecting Preservice Teacher Candidate Identification of Teacher Sexual Misconduct

ERIC Educational Resources Information Center

Haverland, Jeffrey A.

2017-01-01

Using a quantitative research model, this study explored variables affecting pre-service teacher candidate identification of teacher sexual misconduct through a scenario-based survey instrument. Independent variables in this study were respondent gender, student gender, teacher gender, student age-related ambiguity (students depicted were 17),…

Some Variables in Relation to Students' Anxiety in Learning Statistics.

ERIC Educational Resources Information Center

Sutarso, Toto

The purpose of this study was to investigate some variables that relate to students' anxiety in learning statistics. The variables included sex, class level, students' achievement, school, mathematical background, previous statistics courses, and race. The instrument used was the 24-item Students' Attitudes Toward Statistics (STATS), which was…

Variable-Structure Control of a Model Glider Airplane

NASA Technical Reports Server (NTRS)

Waszak, Martin R.; Anderson, Mark R.

2008-01-01

A variable-structure control system designed to enable a fuselage-heavy airplane to recover from spin has been demonstrated in a hand-launched, instrumented model glider airplane. Variable-structure control is a high-speed switching feedback control technique that has been developed for control of nonlinear dynamic systems.

The Impact of a School Loaner-Instrument Program on the Attitudes and Achievement of Low-Income Music Students

ERIC Educational Resources Information Center

Ester, Don; Turner, Kristin

2009-01-01

The purpose of this study was to investigate the impact of a public school loaner-instrument program on the attitudes and achievement of low-income students in an urban environment. Socioeconomic Status (SES) and Instrument Status served as independent variables. Participants (N = 245) completed surveys at the beginning and end of the school year,…

Influence of cyclic torsional preloading on cyclic fatigue resistance of nickel - titanium instruments.

PubMed

Pedullà, E; Lo Savio, F; Boninelli, S; Plotino, G; Grande, N M; Rapisarda, E; La Rosa, G

2015-11-01

To evaluate the effect of different torsional preloads on cyclic fatigue resistance of endodontic rotary instruments constructed from conventional nickel-titanium (NiTi), M-Wire or CM-Wire. Eighty new size 25, 0.06 taper Mtwo instruments (Sweden & Martina), size 25, 0.06 taper HyFlex CM (Coltene/Whaledent, Inc) and X2 ProTaper Next (Dentsply Maillefer) were used. The Torque and distortion angles at failure of new instruments (n = 10) were measured, and 0% (n = 10), 25%, 50% and 75% (n = 20) of the mean ultimate torsional strength as preloading condition were applied according to ISO 3630-1 for each brand. The twenty files tested for every extent of preload were subjected to 20 or 40 torsional cycles (n = 10). After torsional preloading, the number of cycles to failure was evaluated in a simulated canal with 60° angle of curvature and 5 mm of radius of curvature. Data were analysed using two-way analysis of variance. The fracture surface of each fragment was examined with a scanning electron microscope (SEM). Data were analysed by two-way analyses of variance. Preload repetitions did not influence the cyclic fatigue of the three brands; however, the 25%, 50% and 75% torsional preloading significantly reduced the fatigue resistance of all instruments tested (P < 0.01, P < 0.001 and P < 0.0001, respectively) except for the HyFlex CM preloaded with 25% of the maximum torsional strength (P > 0.05). Torsional preloads reduced the cyclic fatigue resistance of conventional and treated (M-wire and CM-wire) NiTi rotary instruments except for size 25, 0.06 taper HyFlex CM instruments with a 25% of torsional preloading. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A Spanish-language patient safety questionnaire to measure medical and nursing students' attitudes and knowledge.

PubMed

Mira, José J; Navarro, Isabel M; Guilabert, Mercedes; Poblete, Rodrigo; Franco, Astolfo L; Jiménez, Pilar; Aquino, Margarita; Fernández-Trujillo, Francisco J; Lorenzo, Susana; Vitaller, Julián; de Valle, Yohana Díaz; Aibar, Carlos; Aranaz, Jesús M; De Pedro, José A

2015-08-01

To design and validate a questionnaire for assessing attitudes and knowledge about patient safety using a sample of medical and nursing students undergoing clinical training in Spain and four countries in Latin America. In this cross-sectional study, a literature review was carried out and total of 786 medical and nursing students were surveyed at eight universities from five countries (Chile, Colombia, El Salvador, Guatemala, and Spain) to develop and refine a Spanish-language questionnaire on knowledge and attitudes about patient safety. The scope of the questionnaire was based on five dimensions (factors) presented in studies related to patient safety culture found in PubMed and Scopus. Based on the five factors, 25 reactive items were developed. Composite reliability indexes and Cronbach's alpha statistics were estimated for each factor, and confirmatory factor analysis was conducted to assess validity. After a pilot test, the questionnaire was refined using confirmatory models, maximum-likelihood estimation, and the variance-covariance matrix (as input). Multiple linear regression models were used to confirm external validity, considering variables related to patient safety culture as dependent variables and the five factors as independent variables. The final instrument was a structured five-point Likert self-administered survey (the "Latino Student Patient Safety Questionnaire") consisting of 21 items grouped into five factors. Compound reliability indexes (Cronbach's alpha statistic) calculated for the five factors were about 0.7 or higher. The results of the multiple linear regression analyses indicated good model fit (goodness-of-fit index: 0.9). Item-total correlations were higher than 0.3 in all cases. The convergent-discriminant validity was adequate. The questionnaire designed and validated in this study assesses nursing and medical students' attitudes and knowledge about patient safety. This instrument could be used to indirectly evaluate whether or not students in health disciplines are acquiring and thus likely to put into practice the professional skills currently considered most appropriate for patient safety.

Cortical thickness maturation and duration of music training: health-promoting activities shape brain development.

PubMed

Hudziak, James J; Albaugh, Matthew D; Ducharme, Simon; Karama, Sherif; Spottswood, Margaret; Crehan, Eileen; Evans, Alan C; Botteron, Kelly N

2014-11-01

To assess the extent to which playing a musical instrument is associated with cortical thickness development among healthy youths. Participants were part of the National Institutes of Health (NIH) Magnetic Resonance Imaging (MRI) Study of Normal Brain Development. This study followed a longitudinal design such that participants underwent MRI scanning and behavioral testing on up to 3 separate visits, occurring at 2-year intervals. MRI, IQ, and music training data were available for 232 youths (334 scans), ranging from 6 to 18 years of age. Cortical thickness was regressed against the number of years that each youth had played a musical instrument. Next, thickness was regressed against an "Age × Years of Playing" interaction term. Age, gender, total brain volume, and scanner were controlled for in analyses. Participant ID was entered as a random effect to account for within-person dependence. False discovery rate correction was applied (p ≤ .05). There was no association between thickness and years playing a musical instrument. The "Age × Years of Playing" interaction was associated with thickness in motor, premotor, and supplementary motor cortices, as well as prefrontal and parietal cortices. Follow-up analysis revealed that music training was associated with an increased rate of thickness maturation. Results were largely unchanged when IQ and handedness were included as covariates. Playing a musical instrument was associated with more rapid cortical thickness maturation within areas implicated in motor planning and coordination, visuospatial ability, and emotion and impulse regulation. However, given the quasi-experimental nature of this study, we cannot rule out the influence of confounding variables. Copyright © 2014 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Shaping ability of reciprocating single-file systems in severely curved canals: WaveOne and Reciproc versus WaveOne Gold and Reciproc blue.

PubMed

Bürklein, Sebastian; Flüch, Stefanie; Schäfer, Edgar

2018-05-18

The aim was to compare the canal straightening of M-wire [Reciproc (VDW, Munich, Germany) and WaveOne (Dentsply Maillefer, Ballaigues, Switzerland)] and gold- and blue-wire heat-treated [Reciproc blue (VDW) and WaveOne Gold (Dentsply Maillefer)] instruments in severely curved root canals. A total of 80 root canals in extracted human teeth with angles of curvatures ranging between 25° and 35° and radii ranging between 3.1 and 8.5 mm were divided into four groups (n = 20). Based on radiographs taken prior to instrumentation, the groups were balanced with respect to the angle and the radius of canal curvature (P = 1.0 and P = 1.0, respectively). All canals were prepared to an apical size 25 according to the manufacturers' instructions. Pre- and post-instrumentation radiographs were superimposed and canal straightening was analysed using a computer imaging programme. Preparation time and instrument failure were also recorded. Data were analysed statistically using ANOVA and Student-Newman-Keuls test. During preparation no instrument fractured. All instruments maintained the original canal curvature well with no significant differences between the instruments (P = 0.278). Regarding preparation time, no significant differences between the four instruments were obtained (P > 0.05). Under the conditions of this study, all instruments respected the original canal curvature well. Instruments were safe to use. The use of the gold- and blue-wire heat-treated instruments was not associated with an improved shaping ability.

Occupational value and relationships to meaning and health: elaborations of the ValMO-model.

PubMed

Erlandsson, Lena-Karin; Eklund, Mona; Persson, Dennis

2011-03-01

This study investigates the theoretical assumption of the Value and Meaning in Occupations model. The aim was to explore the relationship between occupational value, perceived meaning, and subjective health in a sample of individuals of working age, 50 men and 250 women. Frequency of experienced values in occupations was assessed through the Occupational Value instrument with pre-defined items. Perceived meaning was operationalized and assessed by the Sense of Coherence measure. Subjective health was estimated by two questions from the SF-36 questionnaire. The analyses implied descriptive analyses, correlations, and logistic regression analyses in which sociodemographic variables were included. The findings showed highly significant relationships between occupational value and perceived meaning and when belonging to the high group of occupational value the likelihood was tripled of belonging to the high group of perceived meaning. When married or cohabitating there was double the likelihood of belonging to the high group of perceived meaning. Although perceived meaning was found to be positively associated with subjective health, working full time was the most important factor in explaining subjective health, compared with working less than full time. The results confirm assumptions in the ValMO-model, and the importance of focusing on occupational value in clinical practice is highlighted.

Sub-optimal parenting is associated with schizotypic and anxiety personality traits in adulthood.

PubMed

Giakoumaki, S G; Roussos, P; Zouraraki, C; Spanoudakis, E; Mavrikaki, M; Tsapakis, E M; Bitsios, P

2013-05-01

Part of the variation in personality characteristics has been attributed to the child-parent interaction and sub-optimal parenting has been associated with psychiatric morbidity. In the present study, an extensive battery of personality scales (Trait Anxiety Inventory, Behavioural Inhibition/Activation System questionnaire, Eysenck Personality Questionnaire-Revised, Temperament and Character Inventory, Schizotypal Traits Questionnaire, Toronto Alexithymia Scale) and the Parental Bonding Instrument (PBI) were administered in 324 adult healthy males to elucidate the effects of parenting on personality configuration. Personality variables were analysed using Principal Component Analysis (PCA) and the factors "Schizotypy", "Anxiety", "Behavioural activation", "Novelty seeking" and "Reward dependence" were extracted. Associations between personality factors with PBI "care" and "overprotection" scores were examined with regression analyses. Subjects were divided into "parental style" groups and personality factors were subjected to categorical analyses. "Schizotypy" and "Anxiety" were significantly predicted by high maternal overprotection and low paternal care. In addition, the Affectionless control group (low care/high overprotection) had higher "Schizotypy" and "Anxiety" compared with the Optimal Parenting group (high care/low overprotection). These results further validate sub-optimal parenting as an important environmental exposure and extend our understanding on the mechanisms by which it increases risk for psychiatric morbidity. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Predicting critical micelle concentration and micelle molecular weight of polysorbate 80 using compendial methods.

PubMed

Braun, Alexandra C; Ilko, David; Merget, Benjamin; Gieseler, Henning; Germershaus, Oliver; Holzgrabe, Ulrike; Meinel, Lorenz

2015-08-01

This manuscript addresses the capability of compendial methods in controlling polysorbate 80 (PS80) functionality. Based on the analysis of sixteen batches, functionality related characteristics (FRC) including critical micelle concentration (CMC), cloud point, hydrophilic-lipophilic balance (HLB) value and micelle molecular weight were correlated to chemical composition including fatty acids before and after hydrolysis, content of non-esterified polyethylene glycols and sorbitan polyethoxylates, sorbitan- and isosorbide polyethoxylate fatty acid mono- and diesters, polyoxyethylene diesters, and peroxide values. Batches from some suppliers had a high variability in functionality related characteristic (FRC), questioning the ability of the current monograph in controlling these. Interestingly, the combined use of the input parameters oleic acid content and peroxide value - both of which being monographed methods - resulted in a model adequately predicting CMC. Confining the batches to those complying with specifications for peroxide value proved oleic acid content alone as being predictive for CMC. Similarly, a four parameter model based on chemical analyses alone was instrumental in predicting the molecular weight of PS80 micelles. Improved models based on analytical outcome from fingerprint analyses are also presented. A road map controlling PS80 batches with respect to FRC and based on chemical analyses alone is provided for the formulator. Copyright © 2014 Elsevier B.V. All rights reserved.

An Eight-Century High-Resolution Paleoclimate Record From the Cariaco Basin: Baseline Variability and the 20th Century

NASA Astrophysics Data System (ADS)

Black, D. E.; Thunell, R. C.; Kaplan, A.; Tappa, E. J.; Peterson, L. C.

2007-12-01

The Cariaco Basin, Venezuela is well-positioned to record a detailed history of surface ocean changes along the southern margin of the Caribbean and the tropical Atlantic. Varved, high deposition rate sediments deposited under anoxic conditions and an abundance of well-preserved microfossils result in one of the few marine records capable of preserving evidence of interannual- to decadal-scale climate variability in the tropical Atlantic. Here we present Mg/Ca and stable oxygen isotope data with sub-decadal resolution derived from sediments deposited over the last 800 years. Mg/Ca measured on the planktic foraminifer Globigerina bulloides from a Cariaco Basin sediment core strongly correlates with spring (March-May) instrumental SSTs between AD 1870 and 1990. The long-term record displays a surprising amount of variability for a tropical location. The temperature swings are not necessarily related to local upwelling variability, but instead represent wider conditions in the Caribbean and western tropical Atlantic. The Mg/Ca-SST record also captures the decadal and multidecadal variability observed in global land and sea surface temperature anomalies, and correlates with Atlantic tropical storm and hurricane frequency over the late-19th and 20th centuries. On average, 20th century temperatures are not the warmest in the entire record, but they do show the largest increase in magnitude and fastest rate of SST change over the last eight hundred years. Stable oxygen isotope data also correlate well with instrumental SSTs, but not over the full instrumental record. Poor correlations with early instrumental SST data suggest a salinity overprint. However, reconstructing δ- water variability using combined Mg/Ca and δ18O data is not straightforward as the δ- water/salinity relationship varies seasonally in the Cariaco Basin. Comparisons with percent titanium data suggest intervals of both local and regional surface salinity changes over the length of the record.

Are primary care services a substitute or complement for specialty and inpatient services?

PubMed

Fortney, John C; Steffick, Diane E; Burgess, James F; Maciejewski, Matt L; Petersen, Laura A

2005-10-01

To determine whether strategies designed to increase members' use of primary care services result in decreases (substitution) or increases (complementation) in the use and cost of other types of health services. Encounter and cost data were extracted from the Department of Veterans Affairs (VA) administrative data sources for the period 1995-1999. This timeframe captures the VA's natural experiment of increasing geographic access to primary care by establishing new satellite primary care clinics, known as Community-Based Outpatient Clinics (CBOCs). We exploited this natural experiment to estimate the substitutability of primary care for other health services and its impact on cost. Hypotheses were tested using ordinary least squares (OLS) regression, which was potentially subject to endogeneity bias. Endogeneity bias was assessed using a Hausman test. Endogeneity bias was accounted for by using instrumental variables analysis, which capitalized on the establishment of CBOCs to provide an exogenous identifier (change in travel distance to primary care). Demographic, encounter, and cost data were collected for all veterans using VA health services who resided in the catchment areas of new CBOCs and for a matched group of veterans residing outside CBOC catchment areas. Change in distance to primary care was a significant and substantial predictor of change in primary care visits. OLS analyses indicated that an increase in primary care service use was associated with increases in the use of all specialty outpatient services and inpatient services, as well as increases in inpatient and outpatient costs. Hausman tests confirmed that OLS results for specialty mental health encounters and mental health admissions were unbiased, but that results for specialty medical encounters, physical health admissions, and outpatient costs were biased. Instrumental variables analyses indicated that an increase in primary care encounters was associated with a decrease in specialty medical encounters and was not associated with an increase in physical health admissions, or outpatient costs. Results provide evidence that health systems can implement strategies to encourage their members to use more primary care services without driving up physical health costs.

High school students' perceptions of EFL teacher control orientations and their English academic achievement.

PubMed

Kiany, Gholam Reza; Shayestefar, Parvaneh

2011-09-01

BACKGROUND. Theories distinguish between student-initiated and teacher-initiated regulation of students' learning activities, or between strong, shared, or loose teacher control during the completion of learning tasks. Empirical validations for such distinctions are scarce, however. AIM. The present study aimed at (a) investigating students' perceptions of control behaviours exhibited by their English teachers; and (b) exploring the contribution of different types of teacher control behaviours to students' cognitive outcomes (English Achievement). SAMPLE. The sample comprised 732 English as a Foreign Language (EFL) students studying in three major fields of high school (Mathematics, Natural Science, and Humanities). The participants (16-17 years of age) were selected from third-grade classes of 27 EFL teachers working in 25 high schools of 6 main different geographical regions in the Isfahan province, Iran. METHOD. To obtain a comprehensive picture of different control types exhibited by Iranian EFL teachers, the control subscales of the two existing questionnaires, i.e., the Questionnaire on Instructional Behaviours (QIB), adapted by Den Brok et al. (2004) and the Questionnaire on Lesson Activities (QLA) used by Den Brok (2001) were merged to form the Questionnaire of Teacher Control (QTC). The development of this Persian instrument involved several steps: translation and back translation by the researchers, one expert translator, and two EFL teachers; piloting; and a final administration of the questionnaire to the student sample. With respect to the second aim of the study, data regarding students' performances on the Standardized National English Achievement Tests were gathered from local educational offices and schools. RESULTS AND CONCLUSION. Statistical analyses supported acceptable reliability and validity of the instrument. A main factor structure with three types of teacher control (strong/high, shared/mid, and loose/low) was found to underlie students' perceptions. The results of multi-level analyses indicated that a relatively large amount of variance was explained by the control variables and student variables, and teacher control had a statistically significant effect on student outcomes. Students' English achievement was lowest when they felt control was their teachers' prerogative, higher when they themselves exerted their own control (low teacher control), and highest under shared (mid) control behaviours. ©2010 The British Psychological Society.

Satellite oceanography - The instruments

NASA Technical Reports Server (NTRS)

Stewart, R. H.

1981-01-01

It is pointed out that no instrument is sensitive to only one oceanographic variable; rather, each responds to a combination of atmospheric and oceanic phenomena. This complicates data interpretation and usually requires that a number of observations, each sensitive to somewhat different phenomena, be combined to provide unambiguous information. The distinction between active and passive instruments is described. A block diagram illustrating the steps necessary to convert data from satellite instruments into oceanographic information is included, as is a diagram illustrating the operation of a radio-frequency radiometer. Attention is also given to the satellites that carry the various oceanographic instruments.

[Living with achondroplasia- how do young persons with disproportional short stature rate their quality of life and which factors are associated with quality of life?].

PubMed

Rohenkohl, Anja C; Sommer, Rachel; Bestges, Stephanie; Kahrs, Sabine; Klingebiel, Karl-Heinz; Bullinger, Monika; Quitmann, Julia

2015-11-01

Presently, little is known aqout the quality of life (QoL) as well as the strengths and difficulties of young people with achondroplasia. This study describes these patient-reported indicators and identifies possible correlates. At the invitation of a patient organization, a total of 89 short-statured patients aged 8 to 28 years and their parents participated in this study. QoL was assessed cross-sectionally with both generic and disease-specific instruments and the Strengths and Difficulties Questionnaire (SDQ) as a brief behavioral screening. In addition to descriptive analyses, patient data were compared with a reference population. Hierarchical regression analyses reflecting sociodemographic, clinical, and psychological variables were conducted to identify correlates of QoL. QoL and the strengths and difficulties of young patients with achondroplasia did not differ substantially from a healthy norm sample. However, the participants reported more behavioral problems and limitations in their physical and social QoL compared to patients with another short stature diagnosis. Strengths and difficulties, height-related beliefs, and social support correlated significantly with QoL. Adding psychological variables to the regression model increased the proportion of variance explained in QoL. Young persons with achondroplasia did not differ in their QoL and strengths and difficulties from healthy controls. Characteristics such as height appear less important for the self-perceived QoL than are strengths and difficulties and protective psychosocia~factors.

Temporal Variability of Total Ozone in the Asian Region Inferred from Ground-Based and Satellite Measurement Data

NASA Astrophysics Data System (ADS)

Visheratin, K. N.; Nerushev, A. F.; Orozaliev, M. D.; Zheng, Xiangdong; Sun, Shumen; Liu, Li

2017-12-01

This paper reports investigation data on the temporal variability of total ozone content (TOC) in the Central Asian and Tibet Plateau mountain regions obtained by conventional methods, as well as by spectral, cross-wavelet, and composite analyses. The data of ground-based observation stations located at Huang He, Kunming, and Lake Issyk-Kul, along with the satellite data obtained at SBUV/SBUV2 (SBUV merged total and profile ozone data, Version 8.6) for 1980-2013 and OMI (Ozone Monitoring Instrument) and TOU (Total Ozone Unit) for 2009-2013 have been used. The average relative deviation from the SBUV/SBUV2 data is less than 1% in Kunming and Issyk-Kul for the period of 1980-2013, while the Huang He Station is characterized by an excess of the satellite data over the ground-based information at an average deviation of 2%. According to the Fourier analysis results, the distribution of amplitudes and the periods of TOC oscillations within a range of over 14 months is similar for all series analyzed. Meanwhile, according to the cross-wavelet and composite analyses results, the phase relationships between the series may considerably differ, especially in the periods of 5-7 years. The phase of quasi-decennial oscillations in the Kunming Station is close to the 11-year oscillations of the solar cycle, while in the Huang He and Issyk-Kul stations the TOC variations go ahead of the solar cycle.

Continuously-Variable Positive-Mesh Power Transmission

NASA Technical Reports Server (NTRS)

Johnson, J. L.

1982-01-01

Proposed transmission with continuously-variable speed ratio couples two mechanical trigonometric-function generators. Transmission is expected to handle higher loads than conventional variable-pulley drives; and, unlike variable pulley, positive traction through entire drive train with no reliance on friction to transmit power. Able to vary speed continuously through zero and into reverse. Possible applications in instrumentation where drive-train slippage cannot be tolerated.

Estimating QALY gains in applied studies: a review of cost-utility analyses published in 2010.

PubMed

Wisløff, Torbjørn; Hagen, Gunhild; Hamidi, Vida; Movik, Espen; Klemp, Marianne; Olsen, Jan Abel

2014-04-01

Reimbursement agencies in several countries now require health outcomes to be measured in terms of quality-adjusted life-years (QALYs), leading to an immense increase in publications reporting QALY gains. However, there is a growing concern that the various 'multi-attribute utility' (MAU) instruments designed to measure the Q in the QALY yield disparate values, implying that results from different instruments are incommensurable. By reviewing cost-utility analyses published in 2010, we aim to contribute to improved knowledge on how QALYs are currently calculated in applied analyses; how transparently QALY measurement is presented; and how large the expected incremental QALY gains are. We searched Embase, MEDLINE and NHS EED for all cost-utility analyses published in 2010. All analyses that had estimated QALYs gained from health interventions were included. Of the 370 studies included in this review, 48% were pharmacoeconomic evaluations. Active comparators were used in 71% of studies. The median incremental QALY gain was 0.06, which translates to 3 weeks in best imaginable health. The EQ-5D-3L is the dominant instrument used. However, reporting of how QALY gains are estimated is generally inadequate. In 55% of the studies there was no reference to which MAU instrument or direct valuation method QALY data came from. The methods used for estimating expected QALY gains are not transparently reported in published papers. Given the wide variation in utility scores that different methodologies may assign to an identical health state, it is important for journal editors to require a more transparent way of reporting the estimation of incremental QALY gains.

Important variables for parents' postnatal sense of security: evaluating a new Swedish instrument (the PPSS instrument).

PubMed

Persson, Eva K; Dykes, Anna-Karin

2009-08-01

to evaluate dimensions of both parents' postnatal sense of security the first week after childbirth, and to determine associations between the PPSS instrument and different sociodemographic and situational background variables. evaluative, cross-sectional design. 113 mothers and 99 fathers with children live born at term, from five hospitals in southern Sweden. mothers and fathers had similar feelings concerning postnatal sense of security. Of the dimensions in the PPSS instrument, a sense of midwives'/nurses' empowering behaviour, a sense of one's own general well-being and a sense of the mother's well-being as experienced by the father were the most important dimensions for parents' experienced security. A sense of affinity within the family (for both parents) and a sense of manageable breast feeding (for mothers) were not significantly associated with their experienced security. A sense of participation during pregnancy and general anxiety were significantly associated background variables for postnatal sense of security for both parents. For the mothers, parity and a sense that the father was participating during pregnancy were also significantly associated. more focus on parents' participation during pregnancy as well as midwives'/nurses' empowering behaviour during the postnatal period will be beneficial for both parents' postnatal sense of security.

[Validation of a scale of attitudes towards sexuality in a sample of Puerto Rican elderly].

PubMed

Rodríguez Benítez, Rosa Janet; Rodríguez Gómez, José; Sayers Montalvo, Sean

2010-01-01

The literature indicates that elderly population is at high risk that affects their sexual activity; however, this is not the end of sexuality expression in this population. Elderly (people 65 years and older) who are healthy and active has more opportunities of sexual expression and activity in all forms, (including masturbation, and oral sex), and these activities can continue until 74 years or older. This study tries to explore if the Scale of Attitudes towards Sexuality Behavior in the Elderly develop in Puerto Rico, is a valid and reliable instrument to measure attitudes towards the sexuality in an elderly sample. In addition, the research tries to contribute to the progress and development of instruments that measure, and screen, sexuality aspects and risk behaviors that focus in the elderly population. This may help to promote future studies and the development of preventive programs that help to fulfill specific necessities in elderly. The research subjects consist of a secondary database sample of 265 adults of 65 years or older. The design of this study was an ex post facto type. The collected data were analyzed using descriptive statistics and factorial analyses to establish an association between the study variables (i.e., attitudes towards the sexuality and sexuality) using SPSS-X program version 14; also was concluded that the instrument is a valid and reliable (Alpha Cronbach = 0.95), which is considered adequate. It's expected that the scale will be valuable for future research in this area.

Inorganic Salt Interference on CO2+ in Aerodyne AMS and ACSM Organic Aerosol Composition Studies.

PubMed

Pieber, Simone M; El Haddad, Imad; Slowik, Jay G; Canagaratna, Manjula R; Jayne, John T; Platt, Stephen M; Bozzetti, Carlo; Daellenbach, Kaspar R; Fröhlich, Roman; Vlachou, Athanasia; Klein, Felix; Dommen, Josef; Miljevic, Branka; Jiménez, José L; Worsnop, Douglas R; Baltensperger, Urs; Prévôt, André S H

2016-10-04

Aerodyne aerosol mass spectrometer (AMS) and Aerodyne aerosol chemical speciation monitor (ACSM) mass spectra are widely used to quantify organic aerosol (OA) elemental composition, oxidation state, and major environmental sources. The OA CO 2 + fragment is among the most important measurements for such analyses. Here, we show that a non-OA CO 2 + signal can arise from reactions on the particle vaporizer, ion chamber, or both, induced by thermal decomposition products of inorganic salts. In our tests (eight instruments, n = 29), ammonium nitrate (NH 4 NO 3 ) causes a median CO 2 + interference signal of +3.4% relative to nitrate. This interference is highly variable between instruments and with measurement history (percentiles P 10-90 = +0.4 to +10.2%). Other semi-refractory nitrate salts showed 2-10 times enhanced interference compared to that of NH 4 NO 3 , while the ammonium sulfate ((NH 4 ) 2 SO 4 ) induced interference was 3-10 times lower. Propagation of the CO 2 + interference to other ions during standard AMS and ACSM data analysis affects the calculated OA mass, mass spectra, molecular oxygen-to-carbon ratio (O/C), and f 44 . The resulting bias may be trivial for most ambient data sets but can be significant for aerosol with higher inorganic fractions (>50%), e.g., for low ambient temperatures, or laboratory experiments. The large variation between instruments makes it imperative to regularly quantify this effect on individual AMS and ACSM systems.

Muscle Oximetry in Sports Science: A Systematic Review.

PubMed

Perrey, Stephane; Ferrari, Marco

2018-03-01

Since the introduction (in 2006) of commercially available portable wireless muscle oximeters, the use of muscle near-infrared spectroscopy (NIRS) technology is gaining in popularity as an application to observe changes in muscle metabolism and muscle oxygenation during and after exercise or training interventions in both laboratory and applied sports settings. The objectives of this systematic review were to highlight the application of muscle oximetry in evaluating oxidative skeletal muscle performance to sport activities and emphasize how this technology has been applied to exercise and training. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed in a systematic fashion to search, assess and synthesize existing literature on this topic. The Scopus and MEDLINE/PubMed electronic databases were searched to 1 March 2017. Potential inclusions were screened against eligibility criteria relating to recreationally trained to elite athletes, with or without training programs, who must have assessed physiological variables monitored by commercial oximeters or NIRS instrumentation. Of the 14,609 identified records, only 57 studies met the eligibility criteria. This systematic review highlighted a number of key findings in 16 sporting activities. Overall, NIRS information can be used as a marker of skeletal muscle oxidative capacity and for analyzing muscle performance factors. Although NIRS instrumentation is promising in evaluating oxidative skeletal muscle performance when used in sport settings, there is still the need for further instrumental development and randomized/longitudinal trials to support the detailed advantages of muscle oximetry utilization in sports science.

Participant observation of time allocation, direct patient contact and simultaneous activities in hospital physicians.

PubMed

Weigl, Matthias; Müller, Andreas; Zupanc, Andrea; Angerer, Peter

2009-06-29

Hospital physicians' time is a critical resource in medical care. Two aspects are of interest. First, the time spent in direct patient contact - a key principle of effective medical care. Second, simultaneous task performance ('multitasking') which may contribute to medical error, impaired safety behaviour, and stress. There is a call for instruments to assess these aspects. A preliminary study to gain insight into activity patterns, time allocation and simultaneous activities of hospital physicians was carried out. Therefore an observation instrument for time-motion-studies in hospital settings was developed and tested. 35 participant observations of internists and surgeons of a German municipal 300-bed hospital were conducted. Complete day shifts of hospital physicians on wards, emergency ward, intensive care unit, and operating room were continuously observed. Assessed variables of interest were time allocation, share of direct patient contact, and simultaneous activities. Inter-rater agreement of Kappa = .71 points to good reliability of the instrument. Hospital physicians spent 25.5% of their time at work in direct contact with patients. Most time was allocated to documentation and conversation with colleagues and nursing staff. Physicians performed parallel simultaneous activities for 17-20% of their work time. Communication with patients, documentation, and conversation with colleagues and nursing staff were the most frequently observed simultaneous activities. Applying logit-linear analyses, specific primary activities increase the probability of particular simultaneous activities. Patient-related working time in hospitals is limited. The potential detrimental effects of frequently observed simultaneous activities on performance outcomes need further consideration.

Understanding extreme rainfall events in Australia through historical data

NASA Astrophysics Data System (ADS)

Ashcroft, Linden; Karoly, David John

2016-04-01

Historical climate data recovery is still an emerging field in the Australian region. The majority of Australia's instrumental climate analyses begin in 1900 for rainfall and 1910 for temperature, particularly those focussed on extreme event analysis. This data sparsity for the past in turn limits our understanding of long-term climate variability, constraining efforts to predict the impact of future climate change. To address this need for improved historical data in Australia, a new network of recovered climate observations has recently been developed, centred on the highly populated southeastern Australian region (Ashcroft et al., 2014a, 2014b). The dataset includes observations from more than 39 published and unpublished sources and extends from British settlement in 1788 to the formation of the Australian Bureau of Meteorology in 1908. Many of these historical sources provide daily temperature and rainfall information, providing an opportunity to improve understanding of the multidecadal variability of Australia's extreme events. In this study we combine the historical data for three major Australian cities - Melbourne, Sydney and Adelaide - with modern observations to examine extreme rainfall variability over the past 174 years (1839-2013). We first explore two case studies, combining instrumental and documentary evidence to support the occurrence of severe storms in Sydney in 1841 and 1844. These events appear to be at least as extreme as Sydney's modern 24-hour rainfall record. Next we use a suite of rainfall indices to assess the long-term variability of rainfall in southeastern Australia. In particular, we focus on the stationarity of the teleconnection between the El Niño-Southern Oscillation (ENSO) phenomenon and extreme rainfall events. Using ENSO reconstructions derived from both palaeoclimatic and documentary sources, we determine the historical relationship between extreme rainfall in southeastern Australia and ENSO, and examine whether or not this relationship has remained stable since the early to mid-19th century. Ashcroft, L., Gergis, J., Karoly, D.J., 2014a. A historical climate dataset for southeastern Australia, 1788-1859. Geosci. Data J. 1, 158-178. doi:10.1002/gdj3.19 Ashcroft, L., Karoly, D.J., Gergis, J., 2014b. Southeastern Australian climate variability 1860-2009: A multivariate analysis. Int. J. Climatol. 34, 1928-1944. doi:10.1002/joc.3812

Comparative study of mobile Raman instrumentation for art analysis.

PubMed

Vandenabeele, P; Castro, K; Hargreaves, M; Moens, L; Madariaga, J M; Edwards, H G M

2007-04-04

In archaeometry, one of the main concerns is to extract information from an art object, without damaging it. Raman spectroscopy is being applied in this research field with recent developments in mobile instrumentation facilitating more routine analysis. This research paper evaluates the performances of five mobile Raman instruments (Renishaw RA100, Renishaw Portable Raman Analyser RX210, Ocean Optics RSL-1, Delta Nu Inspector Raman, Mobile Art Analyser--MArtA) in three different laboratories. A set of samples were collected, in order to obtain information on the spectral performances of the instruments including: spectral resolution, calibration, laser cut-off, the ability to record spectra of organic and inorganic pigments through varnish layers and on the possibilities to identify biomaterials. Spectra were recorded from predefined regions on a canvas painting to simulate the investigation of artworks and the capabilities to record spectra from hardly accessible areas was evaluated.

Q-SEA – a tool for quality assessment of ethics analyses conducted as part of health technology assessments

PubMed Central

Scott, Anna Mae; Hofmann, Björn; Gutiérrez-Ibarluzea, Iñaki; Bakke Lysdahl, Kristin; Sandman, Lars; Bombard, Yvonne

2017-01-01

Introduction: Assessment of ethics issues is an important part of health technology assessments (HTA). However, in terms of existence of quality assessment tools, ethics for HTA is methodologically underdeveloped in comparison to other areas of HTA, such as clinical or cost effectiveness. Objective: To methodologically advance ethics for HTA by: (1) proposing and elaborating Q-SEA, the first instrument for quality assessment of ethics analyses, and (2) applying Q-SEA to a sample systematic review of ethics for HTA, in order to illustrate and facilitate its use. Methods: To develop a list of items for the Q-SEA instrument, we systematically reviewed the literature on methodology in ethics for HTA, reviewed HTA organizations’ websites, and solicited views from 32 experts in the field of ethics for HTA at two 2-day workshops. We subsequently refined Q-SEA through its application to an ethics analysis conducted for HTA. Results: Q-SEA instrument consists of two domains – the process domain and the output domain. The process domain consists of 5 elements: research question, literature search, inclusion/exclusion criteria, perspective, and ethics framework. The output domain consists of 5 elements: completeness, bias, implications, conceptual clarification, and conflicting values. Conclusion: Q-SEA is the first instrument for quality assessment of ethics analyses in HTA. Further refinements to the instrument to enhance its usability continue. PMID:28326147

Interannual, seasonal and diurnal Mars surface environmental cycles observed from Viking to Curiosity

NASA Astrophysics Data System (ADS)

Martinez, German; Vicente-Retortillo, Álvaro; Kemppinen, Osku; Fischer, Erik; Fairen, Alberto G.; Guzewich, Scott David; Haberle, Robert; Lemmon, Mark T.; Newman, Claire E.; Renno, Nilton O.; Richardson, Mark I.; Smith, Michael D.; De la Torre, Manuel; Vasavada, Ashwin R.

2016-10-01

We analyze in-situ environmental data from the Viking landers to the Curiosity rover to estimate atmospheric pressure, near-surface air and ground temperature, relative humidity, wind speed and dust opacity with the highest confidence possible. We study the interannual, seasonal and diurnal variability of these quantities at the various landing sites over a span of more than twenty Martian years to characterize the climate on Mars and its variability. Additionally, we characterize the radiative environment at the various landing sites by estimating the daily UV irradiation (also called insolation and defined as the total amount of solar UV energy received on flat surface during one sol) and by analyzing its interannual and seasonal variability.In this study we use measurements conducted by the Viking Meteorology Instrument System (VMIS) and Viking lander camera onboard the Viking landers (VL); the Atmospheric Structure Instrument/Meteorology (ASIMET) package and the Imager for Mars Pathfinder (IMP) onboard the Mars Pathfinder (MPF) lander; the Miniature Thermal Emission Spectrometer (Mini-TES) and Pancam instruments onboard the Mars Exploration Rovers (MER); the Meteorological Station (MET), Thermal Electrical Conductivity Probe (TECP) and Phoenix Surface Stereo Imager (SSI) onboard the Phoenix (PHX) lander; and the Rover Environmental Monitoring Station (REMS) and Mastcam instrument onboard the Mars Science Laboratory (MSL) rover.A thorough analysis of in-situ environmental data from past and present missions is important to aid in the selection of the Mars 2020 landing site. We plan to extend our analysis of Mars surface environmental cycles by using upcoming data from the Temperature and Wind sensors (TWINS) instrument onboard the InSight mission and the Mars Environmental Dynamics Analyzer (MEDA) instrument onboard the Mars 2020 mission.

Predicting regime shifts in flow of the Colorado River

USGS Publications Warehouse

Gangopadhyay, Subhrendu; McCabe, Gregory J.

2010-01-01

The effects of continued global warming on water resources are a concern for water managers and stake holders. In the western United States, where the combined climatic demand and consumptive use of water is equal to or greater than the natural supply of water for some locations, there is growing concern regarding the sustainability of future water supplies. In addition to the adverse effects of warming on water supply, another issue for water managers is accounting for, and managing, the effects of natural climatic variability, particularly persistently dry and wet periods. Analyses of paleo-reconstructions of Upper Colorado River basin (UCRB) flow demonstrate that severe sustained droughts, and persistent pluvial periods, are a recurring characteristic of hydroclimate in the Colorado River basin. Shifts between persistently dry and wet regimes (e.g., decadal to multi-decadal variability (D2M)) have important implications for water supply and water management. In this study paleo-reconstructions of UCRB flow are used to compute the risks of shifts between persistently wet and dry regimes given the length of time in a specific regime. Results indicate that low frequency variability of hydro-climatic conditions and the statistics that describe this low frequency variability can be useful to water managers by providing information about the risk of shifting from one hydrologic regime to another. To manage water resources in the future water managers will have to understand the joint hydrologic effects of natural climate variability and global warming. These joint effects may produce future hydrologic conditions that are unprecedented in both the instrumental and paleoclimatic records.

[Study of migratory grief in immigrant patients seen in primary care clinics. Presentation of a migratory grief evaluation questionnaire].

PubMed

de la Revilla, Luis; de los Ríos Álvarez, Ana M; Luna del Castillo, Juan de Dios; Gómez García, Mercedes; Valverde Morillas, Carmen; López Torres, Ginesa

2011-09-01

To validate a questionnaire designed to show the existence of migratory grief (MG) and its dimensions in the immigrant population, and to study its relationship with certain sociodemographic variables. A descriptive, cross-sectional, multicentre study. Consultations in Primary Health Care. The study included 290 Primary Health Care immigrant patients over 18-years old. There were 12 rejections due to, lack of time, absence of a translator, and lack of understanding. An MG questionnaire with 17 questions was employed, carrying out a factor analysis with final extraction of 4 factors explaining 52.1% of overall variance. Sociodemographic variables were collected: gender, age, marital status, nationality, social network, time in Spain, legal and work situation and communication difficulties. Multivariate analysis was performed using the sociodemographic variables. Four factors were found (fear, homesickness, concern and loss of identity), showing that non-communality was < 0.30 and considering that the 4 factors represent the group of variables from the questionnaire. After analysing the correlations between the different factors, it was observed that concern is related to fear and homesickness, this latter being independent from fear. The loss of identity had a low correlation with other factors. Cronbach's alpha showed good consistency in factors 1, 2 and 3. Some sociodemographic variables are associated with the presence of each factor. We present a validated instrument to study and characterise MG, adapted to study the different dimensions of the grief in immigrant population. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Intraindividual variability in executive functions but not speed of processing or conflict resolution predicts performance differences in gait speed in older adults.

PubMed

Holtzer, Roee; Mahoney, Jeannette; Verghese, Joe

2014-08-01

The relationship between executive functions (EF) and gait speed is well established. However, with the exception of dual tasking, the key components of EF that predict differences in gait performance have not been determined. Therefore, the current study was designed to determine whether processing speed, conflict resolution, and intraindividual variability in EF predicted variance in gait performance in single- and dual-task conditions. Participants were 234 nondemented older adults (mean age 76.48 years; 55% women) enrolled in a community-based cohort study. Gait speed was assessed using an instrumented walkway during single- and dual-task conditions. The flanker task was used to assess EF. Results from the linear mixed effects model showed that (a) dual-task interference caused a significant dual-task cost in gait speed (estimate = 35.99; 95% CI = 33.19-38.80) and (b) of the cognitive predictors, only intraindividual variability was associated with gait speed (estimate = -.606; 95% CI = -1.11 to -.10). In unadjusted analyses, the three EF measures were related to gait speed in single- and dual-task conditions. However, in fully adjusted linear regression analysis, only intraindividual variability predicted performance differences in gait speed during dual tasking (B = -.901; 95% CI = -1.557 to -.245). Among the three EF measures assessed, intraindividual variability but not speed of processing or conflict resolution predicted performance differences in gait speed. © The Author 2013. 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.

Quality of integrated chronic care measured by patient survey: identification, selection and application of most appropriate instruments

PubMed Central

Vrijhoef, Hubertus J. M.; Berbee, Rieneke; Wagner, Edward H.; Steuten, Lotte M. G.

2009-01-01

Abstract Objective  To identify the most appropriate generic instrument to measure experience and/or satisfaction of people receiving integrated chronic care. Background  Health care is becoming more user‐centred and, as a result, the experience of users of care and evaluation of their experience and/or satisfaction is taken more seriously. It is unclear to what extent existing instruments are appropriate in measuring the experience and/or satisfaction of people using integrated chronic care. Methods  Instruments were identified by means of a systematic literature review. Appropriateness of instruments was analysed on seven criteria. The two most promising instruments were translated into Dutch, if necessary, and administered to a convenience sample of 109 people with a chronic illness. Data derived from respondents were analysed statistically. Focus‐group interviews were conducted to assess the semantic and technical equivalence as well as opinions of people about the applicability and relevance of the translated instruments. Results  From 37 instruments identified, the Patients’ Assessment of Care for chronIc Conditions (PACIC) and the short form of the Patient Satisfaction Questionnaire III (PSQ‐18) were selected as most promising instruments. Both instruments produced similar median scores across people with different chronic conditions. The overall PACIC and its subscales and the overall PSQ‐18 were highly internally consistent, but not the PSQ‐18 subscales. Overall, the PACIC demonstrated better psychometric characteristics. PACIC and PSQ‐18 scores were found to be moderately correlated. Whereas more respondents preferred the PSQ‐18, focus‐group participants regarded the PACIC to be more applicable and relevant. The technical and semantic equivalence of both instruments were sufficient. Conclusions  Because of its psychometric characteristics, perceived applicability and relevance, the PACIC is the most appropriate instrument to measure the experience of people receiving integrated chronic care. PMID:19709315

Metallurgical characterization of controlled memory wire nickel-titanium rotary instruments.

PubMed

Shen, Ya; Zhou, Hui-Min; Zheng, Yu-Feng; Campbell, Les; Peng, Bin; Haapasalo, Markus

2011-11-01

To improve the fracture resistance of nickel-titanium (NiTi) files, manufacturers have introduced new alloys and developed new manufacturing processes for the fabrication of NiTi files. This study aimed to examine the phase transformation behavior and microstructure of NiTi instruments from a novel controlled memory NiTi wire (CM wire). Instruments of EndoSequence (ES), ProFile (PF), ProFile Vortex (Vortex), Twisted Files (TF), Typhoon (TYP), and Typhoon™ CM (TYP CM), all size 25/.04, were examined by differential scanning calorimetry (DSC) and x-ray diffraction (XRD). Microstructures of etched instruments were observed by optical microscopy and scanning electron microscopy with x-ray energy-dispersive spectrometric (EDS) analyses. The DSC analyses showed that each segment of the TYP CM and Vortex instruments had an austenite transformation completion or austenite-finish (A(f)) temperature exceeding 37°C, whereas the NiTi instruments made from conventional superelastic NiTi wire (ES, PF, and TYP) and TF had A(f) temperatures substantially below mouth temperature. The higher A(f) temperature of TYP CM instruments was consistent with a mixture of austenite and martensite structure, which was observed at room temperature with XRD. All NiTi instruments had room temperature martensite microstructures consisting of colonies of lenticular features with substantial twinning. EDS analysis indicated that the precipitates in all NiTi instruments were titanium-rich, with an approximate composition of Ti(2)Ni. The TYP CM and Vortex instruments with heat treatment contribute to increase austenite transformation temperature. The CM instrument has significant changes in the phase transformation behavior, compared with conventional superelastic NiTi instruments. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Statistical methods used to test for agreement of medical instruments measuring continuous variables in method comparison studies: a systematic review.

PubMed

Zaki, Rafdzah; Bulgiba, Awang; Ismail, Roshidi; Ismail, Noor Azina

2012-01-01

Accurate values are a must in medicine. An important parameter in determining the quality of a medical instrument is agreement with a gold standard. Various statistical methods have been used to test for agreement. Some of these methods have been shown to be inappropriate. This can result in misleading conclusions about the validity of an instrument. The Bland-Altman method is the most popular method judging by the many citations of the article proposing this method. However, the number of citations does not necessarily mean that this method has been applied in agreement research. No previous study has been conducted to look into this. This is the first systematic review to identify statistical methods used to test for agreement of medical instruments. The proportion of various statistical methods found in this review will also reflect the proportion of medical instruments that have been validated using those particular methods in current clinical practice. Five electronic databases were searched between 2007 and 2009 to look for agreement studies. A total of 3,260 titles were initially identified. Only 412 titles were potentially related, and finally 210 fitted the inclusion criteria. The Bland-Altman method is the most popular method with 178 (85%) studies having used this method, followed by the correlation coefficient (27%) and means comparison (18%). Some of the inappropriate methods highlighted by Altman and Bland since the 1980s are still in use. This study finds that the Bland-Altman method is the most popular method used in agreement research. There are still inappropriate applications of statistical methods in some studies. It is important for a clinician or medical researcher to be aware of this issue because misleading conclusions from inappropriate analyses will jeopardize the quality of the evidence, which in turn will influence quality of care given to patients in the future.

Statistical Methods Used to Test for Agreement of Medical Instruments Measuring Continuous Variables in Method Comparison Studies: A Systematic Review

PubMed Central

Zaki, Rafdzah; Bulgiba, Awang; Ismail, Roshidi; Ismail, Noor Azina

2012-01-01

Background Accurate values are a must in medicine. An important parameter in determining the quality of a medical instrument is agreement with a gold standard. Various statistical methods have been used to test for agreement. Some of these methods have been shown to be inappropriate. This can result in misleading conclusions about the validity of an instrument. The Bland-Altman method is the most popular method judging by the many citations of the article proposing this method. However, the number of citations does not necessarily mean that this method has been applied in agreement research. No previous study has been conducted to look into this. This is the first systematic review to identify statistical methods used to test for agreement of medical instruments. The proportion of various statistical methods found in this review will also reflect the proportion of medical instruments that have been validated using those particular methods in current clinical practice. Methodology/Findings Five electronic databases were searched between 2007 and 2009 to look for agreement studies. A total of 3,260 titles were initially identified. Only 412 titles were potentially related, and finally 210 fitted the inclusion criteria. The Bland-Altman method is the most popular method with 178 (85%) studies having used this method, followed by the correlation coefficient (27%) and means comparison (18%). Some of the inappropriate methods highlighted by Altman and Bland since the 1980s are still in use. Conclusions This study finds that the Bland-Altman method is the most popular method used in agreement research. There are still inappropriate applications of statistical methods in some studies. It is important for a clinician or medical researcher to be aware of this issue because misleading conclusions from inappropriate analyses will jeopardize the quality of the evidence, which in turn will influence quality of care given to patients in the future. PMID:22662248

Violent Recidivism: A Long-Time Follow-Up Study of Mentally Disordered Offenders

PubMed Central

Nilsson, Thomas; Wallinius, Märta; Gustavson, Christina; Anckarsäter, Henrik; Kerekes, Nóra

2011-01-01

Background In this prospective study, mentally disordered perpetrators of severe violent and/or sexual crimes were followed through official registers for 59 (range 8 to 73) months. The relapse rate in criminality was assessed, compared between offenders sentenced to prison versus forensic psychiatric care, and the predictive ability of various risk factors (criminological, clinical, and of structured assessment instruments) was investigated. Method One hundred perpetrators were consecutively assessed between 1998 and 2001 by a clinical battery of established instruments covering DSM-IV diagnoses, psychosocial background factors, and structured assessment instruments (HCR-20, PCL-R, and life-time aggression (LHA)). Follow-up data was collected from official registers for: (i) recidivistic crimes, (ii) crimes during ongoing sanction. Results Twenty subjects relapsed in violent criminality during ongoing sanctions (n = 6) or after discharge/parole (n = 14). Individuals in forensic psychiatric care spent significantly more time at liberty after discharge compared to those in prison, but showed significantly fewer relapses. Criminological (age at first conviction), and clinical (conduct disorder and substance abuse/dependence) risk factors, as well as scores on structured assessment instruments, were moderately associated with violent recidivism. Logistic regression analyses showed that the predictive ability of criminological risk factors versus clinical risk factors combined with scores from assessment instruments was comparable, with each set of variables managing to correctly classify about 80% of all individuals, but the only predictors that remained significant in multiple models were criminological (age at first conviction, and a history of substance abuse among primary relatives). Conclusions Only one in five relapsed into serious criminality, with significantly more relapses among subjects sentenced to prison as compared to forensic psychiatric care. Criminological risk factors tended to be the best predictors of violent relapses, while few synergies were seen when the risk factors were combined. Overall, the predictive validity of common risk factors for violent criminality was rather weak. PMID:22022445

ANALYTICAL CHEMISTRY DIVISION ANNUAL PROGRESS REPORT FOR PERIOD ENDING DECEMBER 31, 1961

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1962-02-01

Research and development progress is reported on analytlcal instrumentation, dlssolver-solution analyses, special research problems, reactor projects analyses, x-ray and spectrochemical analyses, mass spectrometry, optical and electron microscopy, radiochemical analyses, nuclear analyses, inorganic preparations, organic preparations, ionic analyses, infrared spectral studies, anodization of sector coils for the Analog II Cyclotron, quality control, process analyses, and the Thermal Breeder Reactor Projects Analytical Chemistry Laboratory. (M.C.G.)

Two Centuries of Climate Variability From a Gulf of Papua Coral Confirms a Coherent, Widespread Multidecadal Signal

NASA Astrophysics Data System (ADS)

Cole, J. E.; Lough, J.; Reed, E. V.; Schrag, D. P.

2016-12-01

The Indo-Pacific warm pool is intimately involved with large-scale climate variability on seasonal to secular time scales. The lack of long instrumental observations in this region has motivated paleoclimatic analyses using diverse proxy data sources. We present here new multicentury paleoclimate records from a Gulf of Papua coral that capture past variability with a Pacific-wide signature. We have developed stable isotope, Sr/Ca, skeletal density, and luminescence data from a coral core recovered at Bramble Cay, Australia (9°S, 144°E). The geochemical records span CE 1775-1993 and are dominated by low-frequency (decade-century scale) variability that is consistent with records from other proxies in the same region, and with other coral records from far-flung sites across the southwest Pacific. Unlike in many Pacific coral records, we observe no strong trend towards warmer conditions. Although skeletal density bands are clearly visible, they show inconsistent seasonal phasing with the geochemical tracers of sea surface temperature (SST; Sr/Ca and oxygen isotope content), and skeletal density does not correlate with these tracers on longer time scales. In this coral, density banding must be controlled by a more complex mix of internal and/or external factors. Luminescent banding and reconstructed salinity provide similar histories, suggesting a common hydroclimatic signal with significant variability at periods of decades and longer. The strong low-frequency behavior in these new climate records of SST and hydroclimate, from a remote region of the Indo-Pacific, confirms an important source of internal climate variability, on a poorly documented time scale, from a region with far-reaching climatic importance.

A critical re-evaluation of the regression model specification in the US D1 EQ-5D value function

PubMed Central

2012-01-01

Background The EQ-5D is a generic health-related quality of life instrument (five dimensions with three levels, 243 health states), used extensively in cost-utility/cost-effectiveness analyses. EQ-5D health states are assigned values on a scale anchored in perfect health (1) and death (0). The dominant procedure for defining values for EQ-5D health states involves regression modeling. These regression models have typically included a constant term, interpreted as the utility loss associated with any movement away from perfect health. The authors of the United States EQ-5D valuation study replaced this constant with a variable, D1, which corresponds to the number of impaired dimensions beyond the first. The aim of this study was to illustrate how the use of the D1 variable in place of a constant is problematic. Methods We compared the original D1 regression model with a mathematically equivalent model with a constant term. Comparisons included implications for the magnitude and statistical significance of the coefficients, multicollinearity (variance inflation factors, or VIFs), number of calculation steps needed to determine tariff values, and consequences for tariff interpretation. Results Using the D1 variable in place of a constant shifted all dummy variable coefficients away from zero by the value of the constant, greatly increased the multicollinearity of the model (maximum VIF of 113.2 vs. 21.2), and increased the mean number of calculation steps required to determine health state values. Discussion Using the D1 variable in place of a constant constitutes an unnecessary complication of the model, obscures the fact that at least two of the main effect dummy variables are statistically nonsignificant, and complicates and biases interpretation of the tariff algorithm. PMID:22244261

A critical re-evaluation of the regression model specification in the US D1 EQ-5D value function.

PubMed

Rand-Hendriksen, Kim; Augestad, Liv A; Dahl, Fredrik A

2012-01-13

The EQ-5D is a generic health-related quality of life instrument (five dimensions with three levels, 243 health states), used extensively in cost-utility/cost-effectiveness analyses. EQ-5D health states are assigned values on a scale anchored in perfect health (1) and death (0).The dominant procedure for defining values for EQ-5D health states involves regression modeling. These regression models have typically included a constant term, interpreted as the utility loss associated with any movement away from perfect health. The authors of the United States EQ-5D valuation study replaced this constant with a variable, D1, which corresponds to the number of impaired dimensions beyond the first. The aim of this study was to illustrate how the use of the D1 variable in place of a constant is problematic. We compared the original D1 regression model with a mathematically equivalent model with a constant term. Comparisons included implications for the magnitude and statistical significance of the coefficients, multicollinearity (variance inflation factors, or VIFs), number of calculation steps needed to determine tariff values, and consequences for tariff interpretation. Using the D1 variable in place of a constant shifted all dummy variable coefficients away from zero by the value of the constant, greatly increased the multicollinearity of the model (maximum VIF of 113.2 vs. 21.2), and increased the mean number of calculation steps required to determine health state values. Using the D1 variable in place of a constant constitutes an unnecessary complication of the model, obscures the fact that at least two of the main effect dummy variables are statistically nonsignificant, and complicates and biases interpretation of the tariff algorithm.

Information transfer across the scales of climate data variability

NASA Astrophysics Data System (ADS)

Palus, Milan; Jajcay, Nikola; Hartman, David; Hlinka, Jaroslav

2015-04-01

Multitude of scales characteristic of the climate system variability requires innovative approaches in analysis of instrumental time series. We present a methodology which starts with a wavelet decomposition of a multi-scale signal into quasi-oscillatory modes of a limited band-with, described using their instantaneous phases and amplitudes. Then their statistical associations are tested in order to search for interactions across time scales. In particular, an information-theoretic formulation of the generalized, nonlinear Granger causality is applied together with surrogate data testing methods [1]. The method [2] uncovers causal influence (in the Granger sense) and information transfer from large-scale modes of climate variability with characteristic time scales from years to almost a decade to regional temperature variability on short time scales. In analyses of daily mean surface air temperature from various European locations an information transfer from larger to smaller scales has been observed as the influence of the phase of slow oscillatory phenomena with periods around 7-8 years on amplitudes of the variability characterized by smaller temporal scales from a few months to annual and quasi-biennial scales [3]. In sea surface temperature data from the tropical Pacific area an influence of quasi-oscillatory phenomena with periods around 4-6 years on the variability on and near the annual scale has been observed. This study is supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Program KONTAKT II, Project No. LH14001. [1] M. Palus, M. Vejmelka, Phys. Rev. E 75, 056211 (2007) [2] M. Palus, Entropy 16(10), 5263-5289 (2014) [3] M. Palus, Phys. Rev. Lett. 112, 078702 (2014)

Instrumental-Music Study and Student Achievement

ERIC Educational Resources Information Center

Heninger, Benjamin Thomas

2017-01-01

This quantitative study explained relationships among independent variables that included instrumental music participation and achievement on a standardized test by participants in the ninth grade at a western Wisconsin high school. The ACT "Aspire" (2017) test is a vertically articulated, standards-based system of assessments. Subtest…

Accounting for standard errors of vision-specific latent trait in regression models.

PubMed

Wong, Wan Ling; Li, Xiang; Li, Jialiang; Wong, Tien Yin; Cheng, Ching-Yu; Lamoureux, Ecosse L

2014-07-11

To demonstrate the effectiveness of Hierarchical Bayesian (HB) approach in a modeling framework for association effects that accounts for SEs of vision-specific latent traits assessed using Rasch analysis. A systematic literature review was conducted in four major ophthalmic journals to evaluate Rasch analysis performed on vision-specific instruments. The HB approach was used to synthesize the Rasch model and multiple linear regression model for the assessment of the association effects related to vision-specific latent traits. The effectiveness of this novel HB one-stage "joint-analysis" approach allows all model parameters to be estimated simultaneously and was compared with the frequently used two-stage "separate-analysis" approach in our simulation study (Rasch analysis followed by traditional statistical analyses without adjustment for SE of latent trait). Sixty-six reviewed articles performed evaluation and validation of vision-specific instruments using Rasch analysis, and 86.4% (n = 57) performed further statistical analyses on the Rasch-scaled data using traditional statistical methods; none took into consideration SEs of the estimated Rasch-scaled scores. The two models on real data differed for effect size estimations and the identification of "independent risk factors." Simulation results showed that our proposed HB one-stage "joint-analysis" approach produces greater accuracy (average of 5-fold decrease in bias) with comparable power and precision in estimation of associations when compared with the frequently used two-stage "separate-analysis" procedure despite accounting for greater uncertainty due to the latent trait. Patient-reported data, using Rasch analysis techniques, do not take into account the SE of latent trait in association analyses. The HB one-stage "joint-analysis" is a better approach, producing accurate effect size estimations and information about the independent association of exposure variables with vision-specific latent traits. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Measuring Medical Housestaff Teamwork Performance Using Multiple Direct Observation Instruments: Comparing Apples and Apples.

PubMed

Weingart, Saul N; Yaghi, Omar; Wetherell, Matthew; Sweeney, Megan

2018-04-10

To examine the composition and concordance of existing instruments used to assess medical teams' performance. A trained observer joined 20 internal medicine housestaff teams for morning work rounds at Tufts Medical Center, a 415-bed Boston teaching hospital, from October through December 2015. The observer rated each team's performance using 9 teamwork observation instruments that examined domains including team structure, leadership, situation monitoring, mutual support, and communication. Observations recorded on paper forms were stored electronically. Scores were normalized from 1 (low) to 5 (high) to account for different rating scales. Overall mean scores were calculated and graphed; weighted scores adjusted for the number of items in each teamwork domain. Teamwork scores were analyzed using t-tests, pair-wise correlations, and the Kruskal-Wallis statistic, and team performance was compared across instruments by domain. The 9 tools incorporated 5 major domains, with 5-35 items per instrument for a total of 161 items per observation session. In weighted and unweighted analyses, the overall teamwork performance score for a given team on a given day varied by instrument. While all of the tools identified the same low outlier, high performers on some instruments were low performers on others. Inconsistent scores for a given team across instruments persisted in domain-level analyses. There was substantial variation in the rating of individual teams assessed concurrently by a single observer using multiple instruments. Since existing teamwork observation tools do not yield concordant assessments, researchers should create better tools for measuring teamwork performance.

Considerations of How to Study Learning Processes when Students Use GIS as an Instrument for Developing Spatial Thinking Skills

ERIC Educational Resources Information Center

Madsen, Lene Moller; Rump, Camilla

2012-01-01

Within the last 30 years, geographical information systems (GIS) have been used increasingly in the training of geographers. On the basis of the philosophy of technology and instrumental genesis, we sketch how the use of instruments interacts with learning processes and outline how this can be studied. We empirically analyse students' learning…

Tools to assess living with a chronic illness: A systematic review.

PubMed

Ambrosio, Leire; Portillo, Mari Carmen

2018-05-16

To analyse the currently available instruments to assess living with a chronic illness and related aspects. A review of the evidence was made using the databases: Medline, CINHAL, PsycINFO, Cochrane Library, Embase and Cuiden. The criteria that limited the search were: the language, English and / or Spanish and studies carried out in an adult population. Years of article publication were not used as a limit. A total of 16 instruments were identified and analysed that apparently measured the concept of living with a chronic illness and/or related aspects. According to the name of the instrument, four seemed to evaluate the concept of living with a chronic illness while the rest of the instruments evaluated aspects intrinsically related to the concept of "living with", such as attributes or the meaning of living with a chronic illness. Different instruments were identified to evaluate daily living for the chronically ill patient, as well as related aspects. According to this review, further validation studies are required in other populations and/or contexts in order to achieve valid and reliable instruments that could be used in clinical practice. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

Development of a Computer-Adaptive Physical Function Instrument for Social Security Administration Disability Determination

PubMed Central

Ni, Pengsheng; McDonough, Christine M.; Jette, Alan M.; Bogusz, Kara; Marfeo, Elizabeth E.; Rasch, Elizabeth K.; Brandt, Diane E.; Meterko, Mark; Chan, Leighton

2014-01-01

Objectives To develop and test an instrument to assess physical function (PF) for Social Security Administration (SSA) disability programs, the SSA-PF. Item Response Theory (IRT) analyses were used to 1) create a calibrated item bank for each of the factors identified in prior factor analyses, 2) assess the fit of the items within each scale, 3) develop separate Computer-Adaptive Test (CAT) instruments for each scale, and 4) conduct initial psychometric testing. Design Cross-sectional data collection; IRT analyses; CAT simulation. Setting Telephone and internet survey. Participants Two samples: 1,017 SSA claimants, and 999 adults from the US general population. Interventions None. Main Outcome Measure Model fit statistics, correlation and reliability coefficients, Results IRT analyses resulted in five unidimensional SSA-PF scales: Changing & Maintaining Body Position, Whole Body Mobility, Upper Body Function, Upper Extremity Fine Motor, and Wheelchair Mobility for a total of 102 items. High CAT accuracy was demonstrated by strong correlations between simulated CAT scores and those from the full item banks. Comparing the simulated CATs to the full item banks, very little loss of reliability or precision was noted, except at the lower and upper ranges of each scale. No difference in response patterns by age or sex was noted. The distributions of claimant scores were shifted to the lower end of each scale compared to those of a sample of US adults. Conclusions The SSA-PF instrument contributes important new methodology for measuring the physical function of adults applying to the SSA disability programs. Initial evaluation revealed that the SSA-PF instrument achieved considerable breadth of coverage in each content domain and demonstrated noteworthy psychometric properties. PMID:23578594

Measuring Medical Students' Empathy: Exploring the Underlying Constructs of and Associations Between Two Widely Used Self-Report Instruments in Five Countries.

PubMed

Costa, Patrício; de Carvalho-Filho, Marco Antonio; Schweller, Marcelo; Thiemann, Pia; Salgueira, Ana; Benson, John; Costa, Manuel João; Quince, Thelma

2017-06-01

Understanding medical student empathy is important to future patient care; however, the definition and development of clinical empathy remain unclear. The authors sought to examine the underlying constructs of two of the most widely used self-report instruments-Davis's Interpersonal Reactivity Index (IRI) and the Jefferson Scale of Empathy version for medical students (JSE-S)-plus, the distinctions and associations between these instruments. Between 2007 and 2014, the authors administered the IRI and JSE-S in three separate studies in five countries, (Brazil, Ireland, New Zealand, Portugal, and the United Kingdom). They collected data from 3,069 undergraduate medical students and performed exploratory factor analyses, correlation analyses, and multiple linear regression analyses. Exploratory factor analysis yielded identical results in each country, confirming the subscale structures of each instrument. Results of correlation analyses indicated significant but weak correlations (r = 0.313) between the total IRI and JSE-S scores. All intercorrelations of IRI and JSE-S subscale scores were statistically significant but weak (range r = -0.040 to 0.306). Multiple linear regression models revealed that the IRI subscales were weak predictors of all JSE-S subscale and total scores. The IRI subscales explained between 9.0% and 15.3% of variance for JSE-S subscales and 19.5% for JSE-S total score. The IRI and JSE-S are only weakly related, suggesting that they may measure different constructs. To better understand this distinction, more studies using both instruments and involving students at different stages in their medical education, as well as more longitudinal and qualitative studies, are needed.

Intrajudge and Interjudge Reliability of the Stuttering Severity Instrument-Fourth Edition.

PubMed

Davidow, Jason H; Scott, Kathleen A

2017-11-08

The Stuttering Severity Instrument (SSI) is a tool used to measure the severity of stuttering. Previous versions of the instrument have known limitations (e.g., Lewis, 1995). The present study examined the intra- and interjudge reliability of the newest version, the Stuttering Severity Instrument-Fourth Edition (SSI-4) (Riley, 2009). Twelve judges who were trained on the SSI-4 protocol participated. Judges collected SSI-4 data while viewing 4 videos of adults who stutter at Time 1 and 4 weeks later at Time 2. Data were analyzed for intra- and interjudge reliability of the SSI-4 subscores (for Frequency, Duration, and Physical Concomitants), total score, and final severity rating. Intra- and interjudge reliability across the subscores and total score concurred with the manual's reported reliability when reliability was calculated using the methods described in the manual. New calculations of judge agreement produced different values from those in the manual-for the 3 subscores, total score, and final severity rating-and provided data absent from the manual. Clinicians and researchers who use the SSI-4 should carefully consider the limitations of the instrument. Investigation into the multitasking demands of the instrument may provide information on whether separating the collection of data for specific variables will improve intra- and interjudge reliability of those variables.

Instrumental variables and Mendelian randomization with invalid instruments

NASA Astrophysics Data System (ADS)

Kang, Hyunseung

Instrumental variables (IV) methods have been widely used to determine the causal effect of a treatment, exposure, policy, or an intervention on an outcome of interest. The IV method relies on having a valid instrument, a variable that is (A1) associated with the exposure, (A2) has no direct effect on the outcome, and (A3) is unrelated to the unmeasured confounders associated with the exposure and the outcome. However, in practice, finding a valid instrument, especially those that satisfy (A2) and (A3), can be challenging. For example, in Mendelian randomization studies where genetic markers are used as instruments, complete knowledge about instruments' validity is equivalent to complete knowledge about the involved genes' functions. The dissertation explores the theory, methods, and application of IV methods when invalid instruments are present. First, when we have multiple candidate instruments, we establish a theoretical bound whereby causal effects are only identified as long as less than 50% of instruments are invalid, without knowing which of the instruments are invalid. We also propose a fast penalized method, called sisVIVE, to estimate the causal effect. We find that sisVIVE outperforms traditional IV methods when invalid instruments are present both in simulation studies as well as in real data analysis. Second, we propose a robust confidence interval under the multiple invalid IV setting. This work is an extension of our work on sisVIVE. However, unlike sisVIVE which is robust to violations of (A2) and (A3), our confidence interval procedure provides honest coverage even if all three assumptions, (A1)-(A3), are violated. Third, we study the single IV setting where the one IV we have may actually be invalid. We propose a nonparametric IV estimation method based on full matching, a technique popular in causal inference for observational data, that leverages observed covariates to make the instrument more valid. We propose an estimator along with inferential results that are robust to mis-specifications of the covariate-outcome model. We also provide a sensitivity analysis should the instrument turn out to be invalid, specifically violate (A3). Fourth, in application work, we study the causal effect of malaria on stunting among children in Ghana. Previous studies on the effect of malaria and stunting were observational and contained various unobserved confounders, most notably nutritional deficiencies. To infer causality, we use the sickle cell genotype, a trait that confers some protection against malaria and was randomly assigned at birth, as an IV and apply our nonparametric IV method. We find that the risk of stunting increases by 0.22 (95% CI: 0.044,1) for every malaria episode and is sensitive to unmeasured confounders.

[Upper extremity kinetics and energy expenditure during walker-assisted gait in children with cerebral palsy].

PubMed

Konop, Katherine A; Strifling, Kelly M B; Wang, Mei; Cao, Kevin; Eastwood, Daniel; Jackson, Scott; Ackman, Jeffrey; Altiok, Haluk; Schwab, Jeffrey; Harris, Gerald F

2009-01-01

We evaluated the relationships between upper extremity (UE) kinetics and the energy expenditure index during anterior and posterior walker-assisted gait in children with spastic diplegic cerebral palsy (CP). Ten children (3 boys, 7 girls; mean age 12.1 years; range 8 to 18 years) with spastic diplegic CP, who ambulated with a walker underwent gait analyses that included UE kinematics and kinetics. Upper extremity kinetics were obtained using instrumented walker handles. Energy expenditure index was obtained using the heart rate method (EEIHR) by subtracting resting heart rate from walking heart rate, and dividing by the walking speed. Correlations were sought between the kinetic variables and the EEIHR and temporal and stride parameters. In general, anterior walker use was associated with a higher EEIHR. Several kinetic variables correlated well with temporal and stride parameters, as well as the EEIHR. All of the significant correlations (r>0.80; p<0.005) occurred during anterior walker use and involved joint reaction forces (JRF) rather than moments. Some variables showed multiple strong correlations during anterior walker use, including the medial JRF in the wrist, the posterior JRF in the elbow, and the inferior and superior JRFs in the shoulder. The observed correlations may indicate a relationship between the force used to advance the body forward within the walker frame and an increased EEIHR. More work is needed to refine the correlations, and to explore relationships with other variables, including the joint kinematics.

Derivation and validation of the Personal Support Algorithm: an evidence-based framework to inform allocation of personal support services in home and community care.

PubMed

Sinn, Chi-Ling Joanna; Jones, Aaron; McMullan, Janet Legge; Ackerman, Nancy; Curtin-Telegdi, Nancy; Eckel, Leslie; Hirdes, John P

2017-11-25

Personal support services enable many individuals to stay in their homes, but there are no standard ways to classify need for functional support in home and community care settings. The goal of this project was to develop an evidence-based clinical tool to inform service planning while allowing for flexibility in care coordinator judgment in response to patient and family circumstances. The sample included 128,169 Ontario home care patients assessed in 2013 and 25,800 Ontario community support clients assessed between 2014 and 2016. Independent variables were drawn from the Resident Assessment Instrument-Home Care and interRAI Community Health Assessment that are standardised, comprehensive, and fully compatible clinical assessments. Clinical expertise and regression analyses identified candidate variables that were entered into decision tree models. The primary dependent variable was the weekly hours of personal support calculated based on the record of billed services. The Personal Support Algorithm classified need for personal support into six groups with a 32-fold difference in average billed hours of personal support services between the highest and lowest group. The algorithm explained 30.8% of the variability in billed personal support services. Care coordinators and managers reported that the guidelines based on the algorithm classification were consistent with their clinical judgment and current practice. The Personal Support Algorithm provides a structured yet flexible decision-support framework that may facilitate a more transparent and equitable approach to the allocation of personal support services.

Combined Effect of Levels in Personal Self-Regulation and Regulatory Teaching on Meta-Cognitive, on Meta-Motivational, and on Academic Achievement Variables in Undergraduate Students.

PubMed

de la Fuente, Jesús; Sander, Paul; Martínez-Vicente, José M; Vera, Mariano; Garzón, Angélica; Fadda, Salvattore

2017-01-01

The Theory of Self- vs . Externally-Regulated Learning™ (SRL vs. ERL) proposed different types of relationships among levels of variables in Personal Self-Regulation (PSR) and Regulatory Teaching (RT) to predict the meta-cognitive, meta-motivational and -emotional variables of learning, and of Academic Achievement in Higher Education. The aim of this investigation was empirical in order to validate the model of the combined effect of low-medium-high levels in PSR and RT on the dependent variables. For the analysis of combinations, a selected sample of 544 undergraduate students from two Spanish universities was used. Data collection was obtained from validated instruments, in Spanish versions. Using an ex-post-facto design, different Univariate and Multivariate Analyses (3 × 1, 3 × 3, and 4 × 1) were conducted. Results provide evidence for a consistent effect of low-medium-high levels of PSR and of RT, thus giving significant partial confirmation of the proposed rational model. As predicted, (1) the levels of PSR and positively and significantly effected the levels of learning approaches, resilience, engagement, academic confidence, test anxiety, and procedural and attitudinal academic achievement; (2) the most favorable type of interaction was a high level of PSR with a high level RT process. The limitations and implications of these results in the design of effective teaching are analyzed, to improve university teaching-learning processes.

Combined Effect of Levels in Personal Self-Regulation and Regulatory Teaching on Meta-Cognitive, on Meta-Motivational, and on Academic Achievement Variables in Undergraduate Students

PubMed Central

de la Fuente, Jesús; Sander, Paul; Martínez-Vicente, José M.; Vera, Mariano; Garzón, Angélica; Fadda, Salvattore

2017-01-01

The Theory of Self- vs. Externally-Regulated Learning™ (SRL vs. ERL) proposed different types of relationships among levels of variables in Personal Self-Regulation (PSR) and Regulatory Teaching (RT) to predict the meta-cognitive, meta-motivational and -emotional variables of learning, and of Academic Achievement in Higher Education. The aim of this investigation was empirical in order to validate the model of the combined effect of low-medium-high levels in PSR and RT on the dependent variables. For the analysis of combinations, a selected sample of 544 undergraduate students from two Spanish universities was used. Data collection was obtained from validated instruments, in Spanish versions. Using an ex-post-facto design, different Univariate and Multivariate Analyses (3 × 1, 3 × 3, and 4 × 1) were conducted. Results provide evidence for a consistent effect of low-medium-high levels of PSR and of RT, thus giving significant partial confirmation of the proposed rational model. As predicted, (1) the levels of PSR and positively and significantly effected the levels of learning approaches, resilience, engagement, academic confidence, test anxiety, and procedural and attitudinal academic achievement; (2) the most favorable type of interaction was a high level of PSR with a high level RT process. The limitations and implications of these results in the design of effective teaching are analyzed, to improve university teaching-learning processes. PMID:28280473

Using SMAP Data to Investigate the Role of Soil Moisture Variability on Realtime Flood Forecasting

NASA Astrophysics Data System (ADS)

Krajewski, W. F.; Jadidoleslam, N.; Mantilla, R.

2017-12-01

The Iowa Flood Center has developed a regional high-resolution flood-forecasting model for the state of Iowa that decomposes the landscape into hillslopes of about 0.1 km2. For the model to benefit, through data assimilation, from SMAP observations of soil moisture (SM) at scales of approximately 100 km2, we are testing a framework to connect SMAP-scale observations to the small-scale SM variability calculated by our rainfall-runoff models. As a step in this direction, we performed data analyses of 15-min point SM observations using a network of about 30 TDR instruments spread throughout the state. We developed a stochastic point-scale SM model that captures 1) SM increases due to rainfall inputs, and 2) SM decay during dry periods. We use a power law model to describe soil moisture decay during dry periods, and a single parameter logistic curve to describe precipitation feedback on soil moisture. We find that the parameters of the models behave as time-independent random variables with stationary distributions. Using data-based simulation, we explore differences in the dynamical range of variability of hillslope and SMAP-scale domains. The simulations allow us to predict the runoff field and streamflow hydrographs for the state of Iowa during the three largest flooding periods (2008, 2014, and 2016). We also use the results to determine the reduction in forecast uncertainty from assimilation of unbiased SMAP-scale soil moisture observations.

The development of a virtual reality training programme for ophthalmology: repeatability and reproducibility (part of the International Forum for Ophthalmic Simulation Studies).

PubMed

Saleh, G M; Theodoraki, K; Gillan, S; Sullivan, P; O'Sullivan, F; Hussain, B; Bunce, C; Athanasiadis, I

2013-11-01

To evaluate the variability of performance among novice ophthalmic trainees in a range of repeated tasks using the Eyesi virtual reality (VR) simulator. Eighteen subjects undertook three attempts of five cataract specific and generic three-dimensional tasks: continuous curvilinear capsulorhexis, cracking and chopping, cataract navigation, bimanual cataract training, anti-tremor. Scores for each attempt were out of a maximum of 100 points. A non-parametric test was used to analyse the data, where a P-value of <0.05 was considered statistically significant. Highly significant differences were found between the scores achieved in the first attempt and that during the second (P<0.0001) and third (P<0.0001) but not between the second and third attempt (P=0.65). There was no significant variability in the overall score between the users (P=0.1104) or in the difference between their highest and lowest score (P=0.3878). Highly significant differences between tasks were shown both in the overall score (P=0.0001) and in the difference between highest and lowest score (P=0.003). This study, which is the first to quantify reproducibility of performance in entry level trainees using a VR tool, demonstrated significant intra-novice variability. The cohort of subjects performed equally overall in the range of tasks (no inter-novice variability) but each showed that performance varies significantly with the complexity of the task when using this high-fidelity instrument.

Individual and organizational factors related to work engagement among home-visiting nurses in Japan.

PubMed

Naruse, Takashi; Sakai, Mahiro; Watai, Izumi; Taguchi, Atsuko; Kuwahara, Yuki; Nagata, Satoko; Murashima, Sachiyo

2013-12-01

The increasing number of elderly people has caused increased demand for home-visiting nurses. Nursing managers should develop healthy workplaces in order to grow their workforce. This study investigated the work engagement of home-visiting nurses as an index of workplace health. The aim of the present study was to reveal factors contributing to work engagement among Japanese home-visiting nurses. An anonymous, self-administered questionnaire was sent to 208 home-visiting nurses from 28 nursing agencies in three districts; 177 (85.1%) returned the questionnaires. The Job Demands-Resources model, which explains the relationship between work environment and employee well-being, was used as a conceptual guide. The authors employed three survey instruments: (i) questions on individual variables; (ii) questions on organizational variables; and (iii) the Utrecht Work Engagement Scale (Japanese version). Multiple regression analyses were performed in order to examine the relationships between individual variables, organizational variables, and work engagement. Nurse managers and nurses who felt that there was a positive relationship between work and family had significantly higher work engagement levels than others. The support of a supervisor was significantly associated with work engagement. Nurses in middle-sized but not large agencies had significantly higher work engagement than nurses in small agencies. Supervisor support and an appropriate number of people reporting to each supervisor are important factors in fostering work engagement among home-visiting nurses. © 2013 The Authors. Japan Journal of Nursing Science © 2013 Japan Academy of Nursing Science.

Design and validation of a standards-based science teacher efficacy instrument

NASA Astrophysics Data System (ADS)

Kerr, Patricia Reda

National standards for K--12 science education address all aspects of science education, with their main emphasis on curriculum---both science subject matter and the process involved in doing science. Standards for science teacher education programs have been developing along a parallel plane, as is self-efficacy research involving classroom teachers. Generally, studies about efficacy have been dichotomous---basing the theoretical underpinnings on the work of either Rotter's Locus of Control theory or on Bandura's explanations of efficacy beliefs and outcome expectancy. This study brings all three threads together---K--12 science standards, teacher education standards, and efficacy beliefs---in an instrument designed to measure science teacher efficacy with items based on identified critical attributes of standards-based science teaching and learning. Based on Bandura's explanation of efficacy being task-specific and having outcome expectancy, a developmental, systematic progression from standards-based strategies and activities to tasks to critical attributes was used to craft items for a standards-based science teacher efficacy instrument. Demographic questions related to school characteristics, teacher characteristics, preservice background, science teaching experience, and post-certification professional development were included in the instrument. The instrument was completed by 102 middle level science teachers, with complete data for 87 teachers. A principal components analysis of the science teachers' responses to the instrument resulted in two components: Standards-Based Science Teacher Efficacy: Beliefs About Teaching (BAT, reliability = .92) and Standards-Based Science Teacher Efficacy: Beliefs About Student Achievement (BASA, reliability = .82). Variables that were characteristic of professional development activities, science content preparation, and school environment were identified as members of the sets of variables predicting the BAT and BASA subscales. Correlations were computed for BAT, BASA, and demographic variables to identify relationships between teacher efficacy, teacher characteristics, and school characteristics. Further research is recommended to refine the instrument and apply its use to a larger sample of science teachers. Its further development also has significance for the enhancement of science teacher education programs.

Personality Traits and Socio-Demographic Variables as Correlates of Counselling Effectiveness of Counsellors in Enugu State, Nigeria

ERIC Educational Resources Information Center

Onyekuru, Bruno U.; Ibegbunam, Josephat

2015-01-01

Quality personality traits and socio-demographic variables are essential elements of effective counselling. This correlational study investigated personality traits and socio-demographic variables as predictors of counselling effectiveness of counsellors in Enugu State. The instruments for data collection were Personality Traits Assessment Scale…

Customisation of an instrument to assess anaesthesiologists' non-technical skills.

PubMed

Jepsen, Rikke M H G; Spanager, Lene; Lyk-Jensen, Helle T; Dieckmann, Peter; Østergaard, Doris

2015-02-22

The objectives of the study were to identify Danish anaesthesiologists' non-technical skills and to customise the Scottish-developed Anaesthetists' Non-Technical Skills instrument for Danish anaesthesiologists. Six semi-structured group interviews were conducted with 31 operating room team members: anaes-thesiologists, nurse anaesthetists, surgeons, and scrub nurses. Interviews were transcribed verbatim and analysed using directed content analysis. Anaesthesiologists' non-technical skills were identified, coded, and sorted using the original instrument as a basis. The resulting prototype instrument was discussed with anaesthesiologists from 17 centres to ensure face validity. Interviews lasted 46-67 minutes. Identified examples of anaesthesiologists' good or poor non-technical skills fit the four categories in the original instrument: situation awareness; decision making; team working; and task management. Anaesthesiologists' leadership role in the operating room was emphasised: the original 'Task Management' category was named 'Leadership'. One new element, 'Demonstrating self-awareness' was added under the category 'Situation Awareness'. Compared with the original instrument, half of the behavioural markers were new, which reflected that being aware of and communicating one's own abilities to the team; working systematically; and speaking up to avoid adverse events were important skills. The Anaesthetists' Non-Technical Skills instrument was customised to a Danish setting using the identified non-technical skills for anaesthesiologists and the original instrument as basis. The customised instrument comprises four categories and 16 underpinning elements supported by multiple behavioural markers. Identifying non-technical skills through semi-structured group interviews and analysing them using direct content analysis proved a useful method for customising an assessment instrument to another setting.

The Effect of Birth Weight on Academic Performance: Instrumental Variable Analysis.

PubMed

Lin, Shi Lin; Leung, Gabriel Matthew; Schooling, C Mary

2017-05-01

Observationally, lower birth weight is usually associated with poorer academic performance; whether this association is causal or the result of confounding is unknown. To investigate this question, we obtained an effect estimate, which can have a causal interpretation under specific assumptions, of birth weight on educational attainment using instrumental variable analysis based on single nucleotide polymorphisms determining birth weight combined with results from the Social Science Genetic Association Consortium study of 126,559 Caucasians. We similarly obtained an estimate of the effect of birth weight on academic performance in 4,067 adolescents from Hong Kong's (Chinese) Children of 1997 birth cohort (1997-2016), using twin status as an instrumental variable. Birth weight was not associated with years of schooling (per 100-g increase in birth weight, -0.006 years, 95% confidence interval (CI): -0.02, 0.01) or college completion (odds ratio = 1.00, 95% CI: 0.96, 1.03). Birth weight was also unrelated to academic performance in adolescents (per 100-g increase in birth weight, -0.004 grade, 95% CI: -0.04, 0.04) using instrumental variable analysis, although conventional regression gave a small positive association (0.02 higher grade, 95% CI: 0.01, 0.03). Observed associations of birth weight with academic performance may not be causal, suggesting that interventions should focus on the contextual factors generating this correlation. © The Author 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.

Categorization of extremely brief auditory stimuli: domain-specific or domain-general processes?

PubMed

Bigand, Emmanuel; Delbé, Charles; Gérard, Yannick; Tillmann, Barbara

2011-01-01

The present study investigated the minimum amount of auditory stimulation that allows differentiation of spoken voices, instrumental music, and environmental sounds. Three new findings were reported. 1) All stimuli were categorized above chance level with 50 ms-segments. 2) When a peak-level normalization was applied, music and voices started to be accurately categorized with 20 ms-segments. When the root-mean-square (RMS) energy of the stimuli was equalized, voice stimuli were better recognized than music and environmental sounds. 3) Further psychoacoustical analyses suggest that the categorization of extremely brief auditory stimuli depends on the variability of their spectral envelope in the used set. These last two findings challenge the interpretation of the voice superiority effect reported in previously published studies and propose a more parsimonious interpretation in terms of an emerging property of auditory categorization processes.

Vacuum variable-angle far-infrared ellipsometer

NASA Astrophysics Data System (ADS)

Friš, Pavel; Dubroka, Adam

2017-11-01

We present the design and performance of a vacuum far-infrared (∼50-680 cm-1) ellipsometer with a rotating analyser. The system is based on a Fourier transform spectrometer, an in-house built ellipsometer chamber and a closed-cycle bolometer. The ellipsometer chamber is equipped with a computer controlled θ-2θ goniometer for automated measurements at various angles of incidence. We compare our measurements on SrTiO3 crystal with the results acquired above 300 cm-1 with a commercially available ellipsometer system. After the calibration of the angle of incidence and after taking into account the finite reflectivity of mirrors in the detector part we obtain a very good agreement between the data from the two instruments. The system can be supplemented with a closed-cycle He cryostat for measurements between 5 and 400 K.

The Relationship between Terrorism and Distress and Drinking: Two Years after September 11, 2001*

PubMed Central

Richman, Judith A.; Shannon, Candice A.; Rospenda, Kathleen M.; Flaherty, Joseph A.; Fendrich, Michael

2014-01-01

This study examined:1) the prevalence of negative beliefs related to terrorism and 2) whether these beliefs were related to distress and drinking. Respondents in a longitudinal cohort study sampled from a United States university workplace were surveyed by mail between 1996 and 2003. Instruments assessed: negative beliefs related to 9/11/01, distress (depression, anxiety, somatization, PTSD-post-traumatic stress disorder), and drinking (frequency, quantity, escapist motives, binge drinking, drinking to intoxication, and problem-related drinking). Regression analyses examined relationships between beliefs and mental health. A sizable percentage of respondents experienced terrorism-related negative beliefs. Higher negative belief scores were related to greater distress and problematic drinking in 2003, controlling for sociodemographic variables and (in most cases) pre-9/11 distress and drinking. Study limitations were noted and future research was recommended. PMID:19895299

Some strategies for quantitative scanning Auger electron microscopy

NASA Technical Reports Server (NTRS)

Browning, R.; Peacock, D. C.; Prutton, M.

1985-01-01

The general applicability of power law forms of the background in electron spectra is pointed out and exploited for background removal from under Auger peaks. This form of B(E) is found to be extremely sensitive to instrumental alignment and to fault-free construction - an observation which can be used to set up analyser configurations in an accurate way. Also, differences between N(E) and B(E) can be used to derive a spectrometer transmission function T(E). The questions of information density in an energy-analysing spatially-resolving instrument are addressed after reliable instrumental characterization has been established. Strategies involving ratio histograms, showing the population distribution of the ratio of a pair of Auger peak heights, composition scatter diagrams and windowed imaging are discussed and illustrated.