Sample records for observational studies methods

  1. Studying Triggers for Interest and Engagement Using Observational Methods

    ERIC Educational Resources Information Center

    Renninger, K. Ann; Bachrach, Jessica E.

    2015-01-01

    In this article, we discuss the contribution of observational methods to understanding the processes involved in triggering interest and establishing engagement. We begin by reviewing the literatures on interest and engagement, noting their similarities, differences, and the utility to each of better understanding the triggering process. We then…

  2. The generalizability study as a method of assessing intra- and interobserver reliability in observational research

    Microsoft Academic Search

    Cathryn L. Booth; Sandra K. Mitchell; Frances K. Solin

    1979-01-01

    Most researchers use interobserver agreement percentages to express the quality of their observational data. A better method\\u000a is the generalizability study, which allows the variance in a set of scores to be partitioned among several sources, such\\u000a as observers, occasions, subjects, and error. In this paper the practical application of generalizability theory is described\\u000a and illustrated, using the frequency and

  3. Generalizing Observational Study Results: Applying Propensity Score Methods to Complex Surveys

    PubMed Central

    DuGoff, Eva H; Schuler, Megan; Stuart, Elizabeth A

    2014-01-01

    ObjectiveTo provide a tutorial for using propensity score methods with complex survey data. Data SourcesSimulated data and the 2008 Medical Expenditure Panel Survey. Study DesignUsing simulation, we compared the following methods for estimating the treatment effect: a naïve estimate (ignoring both survey weights and propensity scores), survey weighting, propensity score methods (nearest neighbor matching, weighting, and subclassification), and propensity score methods in combination with survey weighting. Methods are compared in terms of bias and 95 percent confidence interval coverage. In Example 2, we used these methods to estimate the effect on health care spending of having a generalist versus a specialist as a usual source of care. Principal FindingsIn general, combining a propensity score method and survey weighting is necessary to achieve unbiased treatment effect estimates that are generalizable to the original survey target population. ConclusionsPropensity score methods are an essential tool for addressing confounding in observational studies. Ignoring survey weights may lead to results that are not generalizable to the survey target population. This paper clarifies the appropriate inferences for different propensity score methods and suggests guidelines for selecting an appropriate propensity score method based on a researcher’s goal. PMID:23855598

  4. International Halley watch amateur observers' manual for scientific comet studies. Part 1: Methods

    NASA Technical Reports Server (NTRS)

    Edberg, S. J.

    1983-01-01

    The International Halley Watch is described as well as comets and observing techniques. Information on periodic Comet Halley's apparition for its 1986 perihelion passage is provided. Instructions are given for observation projects valuable to the International Halley Watch in six areas of study: (1) visual observations; (2) photography; (3) astrometry; (4) spectroscopic observations; (5) photoelectric photometry; and (6) meteor observations.

  5. A Method for Detection of Residual Confounding in Time-Series and Other Observational Studies

    PubMed Central

    Flanders, W. Dana; Klein, M.; Darrow, L.A.; Strickland, M.J.; Sarnat, S.E.; Sarnat, J.A.; Waller, L.A.; Winquist, A.; Tolbert, P.E.

    2013-01-01

    Background A difficult issue in observational studies is assessment of whether important confounders are omitted or misspecified. Here, we present a method for assessing whether residual confounding is present. Our method depends on availability of an indicator with two key characteristics: first, it is conditionally independent (given measured exposures and covariates) of the outcome in the absence of confounding, misspecification and measurement errors; second, it is associated with the exposure and, like the exposure, with any unmeasured confounders. Methods We demonstrate the method using a time-series study of the effects of ozone on emergency department visits for asthma in Atlanta. We argue that future air pollution may have the characteristics appropriate for an indicator, in part because future ozone cannot have caused yesterday’s health events. Using directed acyclic graphs and specific causal relationships, we show that one can identify residual confounding using an indicator with the stated characteristics. We use simulations to assess the discriminatory ability of future ozone as an indicator of residual confounding in the association of ozone with asthma-related emergency department visits. Parameter choices are informed by observed data for ozone, meteorologic factors and asthma. Results In simulations, we found that ozone concentrations one day after the emergency department visits had excellent discriminatory ability to detect residual confounding by some factors that were intentionally omitted from the model, but weaker ability for others. Although not the primary goal, the indicator can also signal other forms of modeling errors, including substantial measurement error, and does not distinguish between them. Conclusion The simulations illustrate that the indicator based on future air pollution levels can have excellent discriminatory ability for residual confounding, although performance varied by situation. Application of the method should be evaluated by considering causal relationships for the intended application, and should be accompanied by other approaches, including evaluation of a priori knowledge. PMID:21068669

  6. Are Private Schools Better Than Public Schools? Appraisal for Ireland by Methods for Observational Studies

    PubMed Central

    Pfeffermann, Danny; Landsman, Victoria

    2011-01-01

    In observational studies the assignment of units to treatments is not under control. Consequently, the estimation and comparison of treatment effects based on the empirical distribution of the responses can be biased since the units exposed to the various treatments could differ in important unknown pretreatment characteristics, which are related to the response. An important example studied in this article is the question of whether private schools offer better quality of education than public schools. In order to address this question we use data collected in the year 2000 by OECD for the Programme for International Student Assessment (PISA). Focusing for illustration on scores in mathematics of 15-years old pupils in Ireland, we find that the raw average score of pupils in private schools is higher than of pupils in public schools. However, application of a newly proposed method for observational studies suggests that the less able pupils tend to enroll in public schools, such that their lower scores is not necessarily an indication of bad quality of the public schools. Indeed, when comparing the average score in the two types of schools after adjusting for the enrollment effects, we find quite surprisingly that public schools perform better on average. This outcome is supported by the methods of instrumental variables and latent variables, commonly used by econometricians for analyzing and evaluating social programs. PMID:22242110

  7. Validation of the Work Observation Method By Activity Timing (WOMBAT) method of conducting time-motion observations in critical care settings: an observational study

    Microsoft Academic Search

    Mark A Ballermann; Nicola T Shaw; Damon C Mayes; RT Noel Gibney; Johanna I Westbrook

    2011-01-01

    Background  Electronic documentation handling may facilitate information flows in health care settings to support better coordination\\u000a of care among Health Care Providers (HCPs), but evidence is limited. Methods that accurately depict changes to the workflows\\u000a of HCPs are needed to assess whether the introduction of a Critical Care clinical Information System (CCIS) to two Intensive\\u000a Care Units (ICUs) represents a positive

  8. Adaptive list sequential sampling method for population-based observational studies

    PubMed Central

    2014-01-01

    Background In population-based observational studies, non-participation and delayed response to the invitation to participate are complications that often arise during the recruitment of a sample. When both are not properly dealt with, the composition of the sample can be different from the desired composition. Inviting too many individuals or too few individuals from a particular subgroup could lead to unnecessary costs or decreased precision. Another problem is that there is frequently no or only partial information available about the willingness to participate. In this situation, we cannot adjust the recruitment procedure for non-participation before the recruitment period starts. Methods We have developed an adaptive list sequential sampling method that can deal with unknown participation probabilities and delayed responses to the invitation to participate in the study. In a sequential way, we evaluate whether we should invite a person from the population or not. During this evaluation, we correct for the fact that this person could decline to participate using an estimated participation probability. We use the information from all previously invited persons to estimate the participation probabilities for the non-evaluated individuals. Results The simulations showed that the adaptive list sequential sampling method can be used to estimate the participation probability during the recruitment period, and that it can successfully recruit a sample with a specific composition. Conclusions The adaptive list sequential sampling method can successfully recruit a sample with a specific desired composition when we have partial or no information about the willingness to participate before we start the recruitment period and when individuals may have a delayed response to the invitation. PMID:24965316

  9. An Introduction to Propensity Score Methods for Reducing the Effects of Confounding in Observational Studies

    Microsoft Academic Search

    Peter C. Austin

    2011-01-01

    The propensity score is the probability of treatment assignment conditional on observed baseline characteristics. The propensity score allows one to design and analyze an observational (nonrandomized) study so that it mimics some of the particular characteristics of a randomized controlled trial. In particular, the propensity score is a balancing score: conditional on the propensity score, the distribution of observed baseline

  10. Studies of Trace Gas Chemical Cycles Using Observations, Inverse Methods and Global Chemical Transport Models

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald G.

    2001-01-01

    For interpreting observational data, and in particular for use in inverse methods, accurate and realistic chemical transport models are essential. Toward this end we have, in recent years, helped develop and utilize a number of three-dimensional models including the Model for Atmospheric Transport and Chemistry (MATCH).

  11. An observational study of the nightside ionospheres of Mars and Venus with radio occultation methods

    SciTech Connect

    Zhang, M.H.G. (Austrian Academy of Sciences, Graz (Austria)); Luhmann, J.G. (Univ. of California, Los Angeles (United States)); Kliore, A.J. (Jet Propulsion Lab., Pasadena, CA (United States))

    1990-10-01

    An analysis of Mars and Venus nightside electron density profiles obtained with radio occultation methods shows how the nightside ionospheres of both planets vary with solar zenith angle. From previous studies it is known that the dayside peak electron densities at Mars and Venus show a basic similarity in that they both exhibit Chapman layer-like behavior. In contrast, the peak altitudes at mars behave like an ideal Chapman layer on the dayside, whereas the altitude of the peak at Venus is fairly constant up to the terminator. The effect of major dust storms can also be seen in the peak altitudes at Mars. All Venus nightside electron density profiles show a distinct main peak for both solar minimum and maximum, whereas many profiles from the nightside of Mars do not show any peak at all. This suggests that the electron density in the Mars nightside ionosphere is frequently too low to be detected by radio occultation. On the Pioneer Venus orbiter, disappearing ionospheres were observed near solar maximum in the in-situ data when the solar wind dynamic pressure was exceptionally high. This condition occurs because the high solar wind dynamic pressure decreases the altitude of the ionopause near the terminator below {approximately}250 km, thus reducing the normal nightward transport of dayside ionospheric plasma. On the basis of the Venus observations, one might predict that if a positive correlation of nightside peak density with dynamic pressure was found, it could mean that transport from the dayside is the only significant source for the nightside ionosphere of Mars. The lack of a correlation would imply that the precipitation source at Mars is quite variable.

  12. Studying air pollution with kitt peak solar flux atlas — analysis method and results of observation

    Microsoft Academic Search

    Jianguo Niu; Hiroaki Kuze; Nobuo Takeuchi

    2000-01-01

    For the measurement of atmospheric NO2 vertical column density (VCD), Kitt Peak Solar Flux Atlas can be substituted as an extraterrestrial solar radiation. Compared\\u000a with differential analysis method, the Taylor expansion of integrated transfer equation underestimates the VCD. This underestimation\\u000a is as large as 35% when the amount of NO2 is 1 1017 cm?2 and observation is conducted with an

  13. A Method to Detect Residual Confounding in Spatial and Other Observational Studies

    PubMed Central

    Flanders, W. Dana; Klein, M.; Darrow, L.A.; Strickland, M.J.; Sarnat, S.E.; Sarnat, J.A.; Waller, L.A.; Winquist, A.; Tolbert, P.E.

    2011-01-01

    Background Residual confounding is challenging to detect. We recently described a method for detecting confounding and justified it primarily for time-series studies. The method depends on an indicator with two key characteristics: (1) it is conditionally independent (given measured exposures and covariates) of the outcome, in the absence of confounding, misspecification and measurement errors; and (2) like the exposure, it is associated with confounders, possibly unmeasured. We proposed using future exposure levels as the indicator to detect residual confounding. This choice seems natural for time-series studies because future exposure cannot have caused the event, yet they could be spuriously related to it. A related question – addressed here – is whether an analogous indicator can be used to identify residual confounding in a study based on spatial, rather than temporal, contrasts. Methods Using directed acyclic graphs, we show that future air pollution levels may have the characteristics appropriate for an indicator of residual confounding in spatial studies of environmental exposures. We empirically evaluate performance for spatial studies using simulations. Results In simulations based on a spatial study of ambient air pollution levels and birth weight in Atlanta, and using ambient air pollution one year after conception as the indicator, we were able to detect residual confounding. The discriminatory ability approached 100% for some factors intentionally omitted from the model, but was very weak for others. Conclusion The simulations illustrate that an indicator based on future exposures can have excellent ability to detect residual confounding in spatial studies, although performance varied by situation. PMID:21968772

  14. Extension of Kaplan-Meier Methods in Observational Studies with Time-Varying Treatment

    Microsoft Academic Search

    Stanley Xu; Susan Shetterly; David Powers; Marsha A. Raebel; Thomas T. Tsai; P. Michael Ho; David Magid

    ObjectivesInverse probability of treatment weighted Kaplan-Meier estimates have been developed to compare two treatments in the presence of confounders in observational studies. Recently, stabilized weights were developed to reduce the influence of extreme inverse probability of treatment-weighted weights in estimating treatment effects. The objective of this research was to use adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests to

  15. Case Study in the Santa Susana Mountains: Observing Discontinuities Using Non-invasive Surface Wave Methods

    NASA Astrophysics Data System (ADS)

    Morton, S. L. C.; Miller, R. D.; Vander Velde, E. T.; Bower, M. O.; Tsoflias, G. P.

    2014-12-01

    A case study was performed at a former industrial site in the Santa Susana Mountains in Canoga Park, California in order to observe discontinuities such as faults and fractures that potentially affect groundwater flow and contaminant transport within the study area. The active multi-channel analysis of surface waves (MASW) was performed using a landstreamer and weight drop source along a service road spanning approximately 1.4 miles. From previous geologic investigations, it is assumed that at least two faults cross the seismic profile and that one end of the profile is within a shear zone. The subsurface is composed of brittle to competent sandstone with intermittent shale beds that make up the Chatsworth Formation. Collected data were used to construct 2-D shear-wave velocity profiles and for backscatter analyses. Noise tests from an additional reflection survey along the same road was used as passive MASW to supplement the active data where low frequency data was absent. The goal of this case study is to observe the presence and orientation faults and fractures that could not be determined from surface mapping or downhole geophysical logging. Higher mode surface waves contaminated much of the data providing evidence of the complex geologic structure potentially caused by an abundance of faults, fractures, and changing topography throughout the profile. The passive MASW provided low frequency dispersion information which helped dispersion curve picking where the active data was not sufficient. The backscatter analyses observed several events that coincided with geologic features seen in the MASW results as well as in areas where the higher mode contamination was too great for MASW analysis. As a result, the combination of active MASW, passive MASW, and backscatter analyses provided velocity information at depths to 30 m. Several discontinuities were observed in the velocity profiles and backscatter analyses. These low velocity features may provide information regarding the presence and orientation of faults and fractures after further investigation. Only 51% of the stations were used for characterizing the subsurface before the signal-to-noise ratio and the risk of artifacts and aliasing in the data became too great for extracting reliable results.

  16. ACCURACY OF DIETARY RECALL USING THE USDA 5-STEP MULTIPLE PASS METHOD IN MEN: AN OBSERVATIONAL VALIDATION STUDY.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This observational validation study was conducted under controlled conditions to test the accuracy of dietary recall in normal weight, overweight, and obese men using the USDA 5-Step Multiple-Pass Method for dietary recall. This was a Cross-sectional analysis of actual and recalled intake of food du...

  17. Overview of the Epidemiology Methods and Applications: Strengths and Limitations of Observational Study Designs

    Microsoft Academic Search

    Graham A. Colditz

    2010-01-01

    The impact of study design on the results of medical research has long been an area of both substantial debate and a smaller body of empirical research. Examples come from many disciplines within clinical and public health research. Among the early major contributions in the 1970s was work by Mosteller and colleagues (Gilbert et al., 1997), who noted that innovations

  18. Studies That Observe Humans

    MedlinePLUS

    ... Topic Human testing: Clinical trials Studies that observe humans A study that simply looks at people is ... in the past without counting on a person’s memory. And there’s no way to find out what ...

  19. Inverting GPS Radio Occultation Data Using The Canonical Transform Method: Results From Simulation Studies and Champ Observations

    NASA Astrophysics Data System (ADS)

    Beyerle, G.; Gorbunov, M. E.; Marquardt, C.; Reigber, Ch.; Schmidt, T.; Wickert, J.

    Sounding Earth's atmosphere by GPS radio occultation is a key objective of the Chal- lenging Minisatellite Payload (CHAMP) satellite launched in July 2000. First results from CHAMP indicate that temperature profiles with good accuracy (about 1.5 K) and high vertical resolution can be derived from the mid-troposphere to the upper strato- sphere. In the lower troposphere, however, the inversion process is frequently compli- cated by the occurrence of multi-path propagation rendering solutions using retrieval techniques based on single-ray propagation worthless. Recently, the canonical trans- form (CT) method has been introduced by one of us (M.E.G.) to solve the problem of calculating bending angle profiles within sub-caustic zones. The CT method uses the connection between geometrical and wave optics. The geometric optical rays are described by the Hamilton system in the corresponding phase space. In geometrical optics disentangling individual rays in multi-path zones can be performed by means of a canonical transform such that the projection of the ray manifold to the new ge- ometric coordinate is unique. The corresponding asymptotic transform of the wave field to the single ray representation is then given by the Fourier integral operator as- sociated with the canonical transform. Multiple phase screen simulation studies using refractivity profiles derived from radiosonde measurements demonstrate that the CT method accurately reproduces the true refraction angle profile. In contrast, the stan- dard single-ray retrieval yields dry temperatures deviating by more than 10 K from the observed values. About 4000 CHAMP occultation profiles observed between 14 May and 10 June 2001 have been processed with the CT method. We present first results and compare these with corresponding profiles obtained by the standard retrieval.

  20. A rapid method to assess grape rust mites on leaves and observations from case studies in western Oregon vineyards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rapid method for extracting eriophyoid mites was adapted from previous studies to provide growers and IPM consultants with a practical, efficient, and reliable tool to monitor for rust mites in vineyards. The rinse in bag (RIB) method allows quick extraction of mites from collected plant parts (sh...

  1. Parallax correction in collocating CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) observations: Method and application to convection study

    NASA Astrophysics Data System (ADS)

    Wang, Chunpeng; Luo, Zhengzhao Johnny; Huang, Xianglei

    2011-09-01

    Parallax is associated with an apparent shift of the position of an object when viewed from different angles. For satellite observations, especially observations with clouds, it affects collocation of measurements from different platforms. In this study, we investigate how the parallax problem affects the collocation of CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) observations of tropical convective clouds by examining the impact of parallax correction on statistics of convective cloud properties such as cloud top temperature (CTT) and buoyancy. Previous studies circumvented the parallax problem by imposing a "flat-top" condition on the selection of convective clouds, but it inadvertently biases the statistics toward convections at mature or dissipating stages when convective plumes cease to grow but flatten out to form cirrus anvils. The main findings of this study are the following: (1) Parallax correction reduces CTT of convective clouds; the magnitude of the reduction increases with cloud top height (CTH). (2) Parallax correction also reduces the spread of CTT estimates, making it more closely clustered around the corresponding CTH. (3) The fraction of convection with positive buoyancy decreases after the parallax correction. All these changes that are due to parallax correction are most pronounced for convections above 10-12 km, highlighting the importance of parallax correction in satellite-based study of deep convection. With parallax correction applied, we further examine the contrast in convective cloud buoyancy between land and ocean and day and night and the dependence on convective cloud size; results are consistent with our general understanding of tropical convection.

  2. lecture notes for method Observation & Invention

    E-print Network

    Tollmar, Konrad

    . Observation and Invention is a design method that is suitable to a broad range of product and concept and artefacts. #12;Introduction Through numerous of examples has it been shown that traditional design methods design methods neither fully understand nor capture the needs and the situated use of everyday technology

  3. Using observational methods in nursing research.

    PubMed

    Salmon, Jenny

    2015-07-01

    Observation is a research data-collection method used generally to capture the activities of participants as well as when and where things are happening in a given setting. It checks description of the phenomena against what the researcher perceives to be fact in a rich experiential context. The method's main strength is that it provides direct access to the social phenomena under consideration. It can be used quantitatively or qualitatively, depending on the research question. Challenges in using observation relate to adopting the role of participant or non-participant researcher as observer. This article discusses some of the complexities involved when nurse researchers seek to collect observational data on social processes in naturalistic settings using unstructured or structured observational methods in qualitative research methodology. A glossary of research terms is provided. PMID:26153969

  4. A phantom-based JAFROC observer study of two CT reconstruction methods: the search for optimisation of lesion detection and effective dose

    NASA Astrophysics Data System (ADS)

    Thompson, John D.; Chakraborty, Dev P.; Szczepura, Katy; Vamvakas, Ioannis; Tootell, Andrew; Manning, David J.; Hogg, Peter

    2015-03-01

    Purpose: To investigate the dose saving potential of iterative reconstruction (IR) in a computed tomography (CT) examination of the thorax. Materials and Methods: An anthropomorphic chest phantom containing various configurations of simulated lesions (5, 8, 10 and 12mm; +100, -630 and -800 Hounsfield Units, HU) was imaged on a modern CT system over a tube current range (20, 40, 60 and 80mA). Images were reconstructed with (IR) and filtered back projection (FBP). An ATOM 701D (CIRS, Norfolk, VA) dosimetry phantom was used to measure organ dose. Effective dose was calculated. Eleven observers (15.11+/-8.75 years of experience) completed a free response study, localizing lesions in 544 single CT image slices. A modified jackknife alternative free-response receiver operating characteristic (JAFROC) analysis was completed to look for a significant effect of two factors: reconstruction method and tube current. Alpha was set at 0.05 to control the Type I error in this study. Results: For modified JAFROC analysis of reconstruction method there was no statistically significant difference in lesion detection performance between FBP and IR when figures-of-merit were averaged over tube current (F(1,10)=0.08, p = 0.789). For tube current analysis, significant differences were revealed between multiple pairs of tube current settings (F(3,10) = 16.96, p<0.001) when averaged over image reconstruction method. Conclusion: The free-response study suggests that lesion detection can be optimized at 40mA in this phantom model, a measured effective dose of 0.97mSv. In high-contrast regions the diagnostic value of IR, compared to FBP, is less clear.

  5. PM2.5 Characterization for Time Series Studies: Organic Molecular Marker Speciation Methods and Observations from Daily Measurements in Denver

    PubMed Central

    Dutton, Steven J.; Williams, Daniel E.; Garcia, Jessica K.; Vedal, Sverre; Hannigan, Michael P.

    2009-01-01

    Particulate matter less than 2.5 microns in diameter (PM2.5) has been shown to have a wide range of adverse health effects and consequently is regulated in accordance with the US-EPA’s National Ambient Air Quality Standards. PM2.5 originates from multiple primary sources and is also formed through secondary processes in the atmosphere. It is plausible that some sources form PM2.5 that is more toxic than PM2.5 from other sources. Identifying the responsible sources could provide insight into the biological mechanisms causing the observed health effects and provide a more efficient approach to regulation. This is the goal of the Denver Aerosol Sources and Health (DASH) study, a multi-year PM2.5 source apportionment and health study. The first step in apportioning the PM2.5 to different sources is to determine the chemical make-up of the PM2.5. This paper presents the methodology used during the DASH study for organic speciation of PM2.5. Specifically, methods are covered for solvent extraction of non-polar and semi-polar organic molecular markers using gas chromatography-mass spectrometry (GC-MS). Vast reductions in detection limits were obtained through the use of a programmable temperature vaporization (PTV) inlet along with other method improvements. Results are presented for the first 1.5 years of the DASH study revealing seasonal and source-related patterns in the molecular markers and their long-term correlation structure. Preliminary analysis suggests that point sources are not a significant contributor to the organic molecular markers measured at our receptor site. Several motor vehicle emission markers help identify a gasoline/diesel split in the ambient data. Findings show both similarities and differences when compared with other cities where similar measurements and assessments have been made. PMID:20161318

  6. PM 2.5 characterization for time series studies: Organic molecular marker speciation methods and observations from daily measurements in Denver

    NASA Astrophysics Data System (ADS)

    Dutton, Steven J.; Williams, Daniel E.; Garcia, Jessica K.; Vedal, Sverre; Hannigan, Michael P.

    Particulate matter less than 2.5 microns in diameter (PM 2.5) has been shown to have a wide range of adverse health effects and consequently is regulated in accordance with the US-EPA's National Ambient Air Quality Standards. PM 2.5 originates from multiple primary sources and is also formed through secondary processes in the atmosphere. It is plausible that some sources form PM 2.5 that is more toxic than PM 2.5 from other sources. Identifying the responsible sources could provide insight into the biological mechanisms causing the observed health effects and provide a more efficient approach to regulation. This is the goal of the Denver Aerosol Sources and Health (DASH) study, a multi-year PM 2.5 source apportionment and health study. The first step in apportioning the PM 2.5 to different sources is to determine the chemical make-up of the PM 2.5. This paper presents the methodology used during the DASH study for organic speciation of PM 2.5. Specifically, methods are covered for solvent extraction of non-polar and semi-polar organic molecular markers using gas chromatography-mass spectrometry (GC-MS). Vast reductions in detection limits were obtained through the use of a programmable temperature vaporization (PTV) inlet along with other method improvements. Results are presented for the first 1.5 years of the DASH study revealing seasonal and source-related patterns in the molecular markers and their long-term correlation structure. Preliminary analysis suggests that point sources are not a significant contributor to the organic molecular markers measured at our receptor site. Several motor vehicle emission markers help identify a gasoline/diesel split in the ambient data. Findings show both similarities and differences when compared with other cities where similar measurements and assessments have been made.

  7. Determination of the best method to estimate glomerular filtration rate from serum creatinine in adult patients with sickle cell disease: a prospective observational cohort study

    PubMed Central

    2012-01-01

    Background Sickle cell disease (SCD) leads to tissue hypoxia resulting in chronic organ dysfunction including SCD associated nephropathy. The goal of our study was to determine the best equation to estimate glomerular filtration rate (GFR) in SCD adult patients. Methods We conducted a prospective observational cohort study. Since 2007, all adult SCD patients in steady state, followed in two medical departments, have had their GFR measured using iohexol plasma clearance (gold standard). The Cockcroft-Gault, MDRD-v4, CKP-EPI and finally, MDRD and CKD-EPI equations without adjustment for ethnicity were tested to estimate GFR from serum creatinine. Estimated GFRs were compared to measured GFRs according to the graphical Bland and Altman method. Results Sixty-four SCD patients (16 men, median age 27.5?years [range 18.0-67.5], 41 with SS-genotype were studied. They were Sub-Saharan Africa and French West Indies natives and predominantly lean (median body mass index: 22?kg/m2 [16-33]). Hyperfiltration (defined as measured GFR >110?mL/min/1.73?m2) was detected in 53.1% of patients. Urinary albumin/creatinine ratio was higher in patients with hyperfiltration than in patients with normal GFR (4.05?mg/mmol [0.14-60] versus 0.4?mg/mmol [0.7-81], p?=?0.01). The CKD-EPI equation without adjustment for ethnicity had both the lowest bias and the greatest precision. Differences between estimated GFRs using the CKP-EPI equation and measured GFRs decreased with increasing GFR values, whereas it increased with the Cockcroft-Gault and MDRD-v4 equations. Conclusions We confirm that SCD patients have a high rate of glomerular hyperfiltration, which is frequently associated with microalbuminuria or macroalbuminuria. In non-Afro-American SCD patients, the best method for estimating GFR from serum creatinine is the CKD-EPI equation without adjustment for ethnicity. This equation is particularly accurate to estimate high GFR values, including glomerular hyperfiltration, and thus should be recommended to screen SCD adult patients at high risk for SCD nephropathy. PMID:22866669

  8. Methods of Studying Persons.

    ERIC Educational Resources Information Center

    Heinemann, Allen W.; Shontz, Franklin C.

    1985-01-01

    Describes a method that permits answering research questions of general importance by examining individuals in a comprehensive, whole-person manner. Discusses their use in two studies of persons with spinal cord injuries. (LLL)

  9. Occupational stressors and hypertension: a multi-method study using observer-based job analysis and self-reports in urban transit operators

    Microsoft Academic Search

    Birgit A. Greiner; Niklas Krause; David Ragland; J. M. June M. Fisher

    2004-01-01

    This multi-method study aimed to disentangle objective and subjective components of job stressors and determine the role of each for hypertension risk. Because research on job stressors and hypertension has been exclusively based on self-reports of stressors, the tendency of some individuals to use denial and repressive coping might be responsible for the inconclusive results in previous studies. Stressor measures

  10. A Method for Weak Lensing Observations

    E-print Network

    Nick Kaiser; Gordon Squires; Tom Broadhurst

    1994-11-01

    We develop and test a method for measuring the gravitational lensing induced distortion of faint background galaxies. We first describe how we locate the galaxies and measure a 2-component `polarisation' or ellipticity statistic $e_\\alpha$ whose expectation value should be proportional to the gravitational shear $\\gamma_\\alpha$. We then show that an anisotropic instrumental psf perturbs the polarisation by $\\delta e_\\alpha = P^s_{\\alpha\\beta} p_\\beta$, where $p_\\alpha$ is a measure of the psf anisotropy and $P^s_{\\alpha\\beta}$ is the `linearised smear polarisability tensor'. By estimating $P^s_{\\alpha\\beta}$ for each object we can determine $p_\\alpha$ from the foreground stars and apply a correction $-P^s_{\\alpha\\beta}p_\\beta$ to the galaxies. We test this procedure using deep high-resolution images from HST which are smeared with an anisotropic psf and then have noise added to simulate ground-based observations. We find that the procedure works very well. A similar analysis yields a linear shear polarisability tensor $P^\\gamma_{\\alpha\\beta}$ which describes the response to a gravitational shear. This calibrates the polarisation-shear relation, but only for galaxies which are well resolved. To empirically calibrate the effect of seeing on the smaller galaxies we artificially stretch HST images to simulate lensing and then degrade them as before. These experiments provide a rigorous and exacting test of the method under realistic conditions. They show that it is possible to remove the effect of instrumental psf anisotropy, and that the method provides an efficient and quantitative measurement of the gravitational shear.

  11. Evaluation of internal noise methods for Hotelling observer models

    SciTech Connect

    Zhang Yani; Pham, Binh T.; Eckstein, Miguel P. [Vision and Image Understanding Laboratory, Department of Psychology, University of California, Santa Barbara California, 93106 (United States)

    2007-08-15

    The inclusion of internal noise in model observers is a common method to allow for quantitative comparisons between human and model observer performance in visual detection tasks. In this article, we studied two different strategies for inserting internal noise into Hotelling model observers. In the first strategy, internal noise was added to the output of individual channels: (a) Independent nonuniform channel noise, (b) independent uniform channel noise. In the second strategy, internal noise was added to the decision variable arising from the combination of channel responses. The standard deviation of the zero mean internal noise was either constant or proportional to: (a) the decision variable's standard deviation due to the external noise, (b) the decision variable's variance caused by the external noise, (c) the decision variable magnitude on a trial to trial basis. We tested three model observers: square window Hotelling observer (HO), channelized Hotelling observer (CHO), and Laguerre-Gauss Hotelling observer (LGHO) using a four alternative forced choice (4AFC) signal known exactly but variable task with a simulated signal embedded in real x-ray coronary angiogram backgrounds. The results showed that the internal noise method that led to the best prediction of human performance differed across the studied model observers. The CHO model best predicted human observer performance with the channel internal noise. The HO and LGHO best predicted human observer performance with the decision variable internal noise. The present results might guide researchers with the choice of methods to include internal noise into Hotelling model observers when evaluating and optimizing medical image quality.

  12. Methods of Scientific Observation and Analysis in

    E-print Network

    Bremen, Universität

    , errors, ") ! Brain activity (PET, EEG, (f)MRI) 2 Simple Observations ! Simple observing will not tell you factors. 11 Unwanted Influences ! Order of words. ! Properties of words (length, meaning, "). ! Number to be minimized either by control or by randomization. 14 Correlation ! Two properties are correlated

  13. Basic Caenorhabditis elegans Methods: Synchronization and Observation

    PubMed Central

    Porta-de-la-Riva, Montserrat; Fontrodona, Laura; Villanueva, Alberto; Cerón, Julián

    2012-01-01

    Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has since been used extensively as a model organism 1. C. elegans possesses key attributes such as simplicity, transparency and short life cycle that have made it a suitable experimental system for fundamental biological studies for many years 2. Discoveries in this nematode have broad implications because many cellular and molecular processes that control animal development are evolutionary conserved 3. C. elegans life cycle goes through an embryonic stage and four larval stages before animals reach adulthood. Development can take 2 to 4 days depending on the temperature. In each of the stages several characteristic traits can be observed. The knowledge of its complete cell lineage 4,5 together with the deep annotation of its genome turn this nematode into a great model in fields as diverse as the neurobiology 6, aging 7,8, stem cell biology 9 and germ line biology 10. An additional feature that makes C. elegans an attractive model to work with is the possibility of obtaining populations of worms synchronized at a specific stage through a relatively easy protocol. The ease of maintaining and propagating this nematode added to the possibility of synchronization provide a powerful tool to obtain large amounts of worms, which can be used for a wide variety of small or high-throughput experiments such as RNAi screens, microarrays, massive sequencing, immunoblot or in situ hybridization, among others. Because of its transparency, C. elegans structures can be distinguished under the microscope using Differential Interference Contrast microscopy, also known as Nomarski microscopy. The use of a fluorescent DNA binder, DAPI (4',6-diamidino-2-phenylindole), for instance, can lead to the specific identification and localization of individual cells, as well as subcellular structures/defects associated to them. PMID:22710399

  14. Basic Caenorhabditis elegans methods: synchronization and observation.

    PubMed

    Porta-de-la-Riva, Montserrat; Fontrodona, Laura; Villanueva, Alberto; Cerón, Julián

    2012-01-01

    Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has since been used extensively as a model organism. C. elegans possesses key attributes such as simplicity, transparency and short life cycle that have made it a suitable experimental system for fundamental biological studies for many years. Discoveries in this nematode have broad implications because many cellular and molecular processes that control animal development are evolutionary conserved. C. elegans life cycle goes through an embryonic stage and four larval stages before animals reach adulthood. Development can take 2 to 4 days depending on the temperature. In each of the stages several characteristic traits can be observed. The knowledge of its complete cell lineage together with the deep annotation of its genome turn this nematode into a great model in fields as diverse as the neurobiology, aging, stem cell biology and germ line biology. An additional feature that makes C. elegans an attractive model to work with is the possibility of obtaining populations of worms synchronized at a specific stage through a relatively easy protocol. The ease of maintaining and propagating this nematode added to the possibility of synchronization provide a powerful tool to obtain large amounts of worms, which can be used for a wide variety of small or high-throughput experiments such as RNAi screens, microarrays, massive sequencing, immunoblot or in situ hybridization, among others. Because of its transparency, C. elegans structures can be distinguished under the microscope using Differential Interference Contrast microscopy, also known as Nomarski microscopy. The use of a fluorescent DNA binder, DAPI (4',6-diamidino-2-phenylindole), for instance, can lead to the specific identification and localization of individual cells, as well as subcellular structures/defects associated to them. PMID:22710399

  15. A pragmatic method for electronic medical record-based observational studies: developing an electronic medical records retrieval system for clinical research

    PubMed Central

    Yamamoto, Keiichi; Sumi, Eriko; Yamazaki, Toru; Asai, Keita; Yamori, Masashi; Teramukai, Satoshi; Bessho, Kazuhisa; Yokode, Masayuki; Fukushima, Masanori

    2012-01-01

    Objective The use of electronic medical record (EMR) data is necessary to improve clinical research efficiency. However, it is not easy to identify patients who meet research eligibility criteria and collect the necessary information from EMRs because the data collection process must integrate various techniques, including the development of a data warehouse and translation of eligibility criteria into computable criteria. This research aimed to demonstrate an electronic medical records retrieval system (ERS) and an example of a hospital-based cohort study that identified both patients and exposure with an ERS. We also evaluated the feasibility and usefulness of the method. Design The system was developed and evaluated. Participants In total, 800?000 cases of clinical information stored in EMRs at our hospital were used. Primary and secondary outcome measures The feasibility and usefulness of the ERS, the method to convert text from eligible criteria to computable criteria, and a confirmation method to increase research data accuracy. Results To comprehensively and efficiently collect information from patients participating in clinical research, we developed an ERS. To create the ERS database, we designed a multidimensional data model optimised for patient identification. We also devised practical methods to translate narrative eligibility criteria into computable parameters. We applied the system to an actual hospital-based cohort study performed at our hospital and converted the test results into computable criteria. Based on this information, we identified eligible patients and extracted data necessary for confirmation by our investigators and for statistical analyses with our ERS. Conclusions We propose a pragmatic methodology to identify patients from EMRs who meet clinical research eligibility criteria. Our ERS allowed for the efficient collection of information on the eligibility of a given patient, reduced the labour required from the investigators and improved the reliability of the results. PMID:23117567

  16. Computerised lung sound analysis to improve the specificity of paediatric pneumonia diagnosis in resource-poor settings: protocol and methods for an observational study

    PubMed Central

    Gilman, Robert H; Tielsch, James M; Steinhoff, Mark; Figueroa, Dante; Rodriguez, Shalim; Caffo, Brian; Tracey, Brian; Elhilali, Mounya; West, James; Checkley, William

    2012-01-01

    Introduction WHO case management algorithm for paediatric pneumonia relies solely on symptoms of shortness of breath or cough and tachypnoea for treatment and has poor diagnostic specificity, tends to increase antibiotic resistance. Alternatives, including oxygen saturation measurement, chest ultrasound and chest auscultation, exist but with potential disadvantages. Electronic auscultation has potential for improved detection of paediatric pneumonia but has yet to be standardised. The authors aim to investigate the use of electronic auscultation to improve the specificity of the current WHO algorithm in developing countries. Methods This study is designed to test the hypothesis that pulmonary pathology can be differentiated from normal using computerised lung sound analysis (CLSA). The authors will record lung sounds from 600 children aged ?5?years, 100 each with consolidative pneumonia, diffuse interstitial pneumonia, asthma, bronchiolitis, upper respiratory infections and normal lungs at a children's hospital in Lima, Peru. The authors will compare CLSA with the WHO algorithm and other detection approaches, including physical exam findings, chest ultrasound and microbiologic testing to construct an improved algorithm for pneumonia diagnosis. Discussion This study will develop standardised methods for electronic auscultation and chest ultrasound and compare their utility for detection of pneumonia to standard approaches. Utilising signal processing techniques, the authors aim to characterise lung sounds and through machine learning, develop a classification system to distinguish pathologic sounds. Data will allow a better understanding of the benefits and limitations of novel diagnostic techniques in paediatric pneumonia. PMID:22307098

  17. Offering fragile X syndrome carrier screening: a prospective mixed-methods observational study comparing carrier screening of pregnant and non-pregnant women in the general population

    PubMed Central

    Martyn, M; Anderson, V; Archibald, A; Carter, R; Cohen, J; Delatycki, M; Donath, S; Emery, J; Halliday, J; Hill, M; Sheffield, L; Slater, H; Tassone, F; Younie, S; Metcalfe, S

    2013-01-01

    Introduction Fragile X syndrome (FXS) is the leading cause of inherited intellectual and developmental disability. Policy development relating to carrier screening programmes for FXS requires input from large studies examining not only test uptake but also psychosocial aspects. This study will compare carrier screening in pregnant and non-pregnant populations, examining informed decision-making, psychosocial issues and health economics. Methods and Analysis Pregnant and non-pregnant women are being recruited from general practices and obstetric services. Women receive study information either in person or through clinic mail outs. Women are provided pretest counselling by a genetic counsellor and make a decision about testing in their own time. Data are being collected from two questionnaires: one completed at the time of making the decision about testing and the second 1?month later. Additional data are gathered through qualitative interviews conducted at several time points with a subset of participating women, including all women with a positive test result, and with staff from recruiting clinics. A minimum sample size of 500 women/group has been calculated to give us 88% power to detect a 10% difference in test uptake and 87% power to detect a 10% difference in informed choice between the pregnant and non-pregnant groups. Questionnaire data will be analysed using descriptive statistics and multivariate logistic regression models. Interview data will be thematically analysed. Willingness-to-pay and cost effectiveness analyses will also be performed. Recruitment started in July 2009 and data collection will be completed by December 2013. Ethics and Dissemination Ethics approval has been granted by the Universities of Melbourne and Western Australia and by recruiting clinics, where required. Results will be reported in peer-reviewed publications, conference presentations and through a website http://www.fragilexscreening.net.au. The results of this study will make a significant contribution to discussions about the wider introduction of population carrier screening for FXS. PMID:24022395

  18. Parent-Collected Behavioral Observations: An Empirical Comparison of Methods

    ERIC Educational Resources Information Center

    Nadler, Cy B.; Roberts, Mark W.

    2013-01-01

    Treatments for disruptive behaviors are often guided by parent reports on questionnaires, rather than by multiple methods of assessment. Professional observations and clinic analogs exist to complement questionnaires, but parents can also collect useful behavioral observations to inform and guide treatment. Two parent observation methods of child…

  19. Spatial four-alternative forced-choice method is the preferred psychophysical method for naïve observers.

    PubMed

    Jäkel, Frank; Wichmann, Felix A

    2006-01-01

    H. R. Blackwell (1952) investigated the influence of different psychophysical methods and procedures on detection thresholds. He found that the temporal two-interval forced-choice method (2-IFC) combined with feedback, blocked constant stimulus presentation with few different stimulus intensities, and highly trained observers resulted in the "best" threshold estimates. This recommendation is in current practice in many psychophysical laboratories and has entered the psychophysicists' "folk wisdom" of how to run proper psychophysical experiments. However, Blackwell's recommendations explicitly require experienced observers, whereas many psychophysical studies, particularly with children or within a clinical setting, are performed with naïve observers. In a series of psychophysical experiments, we find a striking and consistent discrepancy between naïve observers' behavior and that reported for experienced observers by Blackwell: Naïve observers show the "best" threshold estimates for the spatial four-alternative forced-choice method (4-AFC) and the worst for the commonly employed temporal 2-IFC. We repeated our study with a highly experienced psychophysical observer, and he replicated Blackwell's findings exactly, thus suggesting that it is indeed the difference in psychophysical experience that causes the discrepancy between our findings and those of Blackwell. In addition, we explore the efficiency of different methods and show 4-AFC to be more than 3.5 times more efficient than 2-IFC under realistic conditions. While we have found that 4-AFC consistently gives lower thresholds than 2-IFC in detection tasks, we have found the opposite for discrimination tasks. This discrepancy suggests that there are large extrasensory influences on thresholds--sensory memory for IFC methods and spatial attention for spatial forced-choice methods--that are critical but, alas, not part of theoretical approaches to psychophysics such as signal detection theory. PMID:17209737

  20. RECORDS AND OBSERVATIONS FROM PLANKTON GRID STUDIES OFF BAJA

    E-print Network

    422 RECORDS AND OBSERVATIONS FROM PLANKTON GRID STUDIES OFF BAJA CALIFORNIA, APRIL 1952 SPECIAL AND OBSERVATIONS FROM PLANKTON GRID STUDIES OFF BAJA CALIFORNIA, APRIL 1952 by David Kramer United States Fish;#12;CONTENTS Page Introduction 1 Survey design 2 Methods of sampling 2 Sardine eggs 2 Fish larvae 11 Plankton

  1. Earth Observing System: Global Observations to Study the Earth's Environment

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2003-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During the last couple of years, four EOS science missions were launched, representing observations of (i) total solar irradiance, (ii) Earth radiation budget, (iii) land cover & land use change, (iv) ocean processes (vector wind, sea surface temperature, and ocean color), (v) atmospheric processes (aerosol and cloud properties, water vapor, and temperature and moisture profiles), and (vi) tropospheric chemistry. In succeeding years many more satellites will be launched that will contribute immeasurably to our understanding of the Earth's environment. In this presentation I will describe how scientists are using NASA's Earth science data to examine land use and natural hazards, environmental air quality, including: dust storms over the worlds deserts, cloud and radiation properties, sea surface temperature, and winds over the ocean, with a special emphasis on satellite observations available for studying the southern African environment.

  2. Methods on observation of fluorescence micro-imaging for microalgae

    NASA Astrophysics Data System (ADS)

    Ou, Lin; Zhuang, Hui-ru; Chen, Rong; Lei, Jin-pin; Liao, Xiao-hua; Lin, Wen-suo

    2007-11-01

    Objective: Auto-fluorescence micro-imaging of microalgae are observed by using of laser scanning confocal microscopy (LSCM) and fluorescence microscopy, so as to investigate the effect of auto fluorescence alteration on growth of irradiated microalgae irradiated, meanwhile, the method of microalgae cells stained also to be studied. Methods: Platymonas subcordiformis, Phaeodactylum tricormutum and Isochyrsis zhanjiangensis cells are stained with acridine orange, and observed by fluorescence microscopy; the three types microalgae mentioned above are irradiated by Nd:YAP laser with 10w at 1341nm, irradiating time:12s, 30s, 35s and 55s, than to be cultured 6 days, and the auto fluorescence images and fluorescence spectra of algae cells are obtained by LSCM on lambda scan mode, at excitation 488nm (Ar + laser). Results: It is showed that the shapes and the structural features of microalgae cells stained can be seen clearly, and the cytoplasm and nucleus also can be observed. The chloroplasts in cell is bigger on promoting effects, conversely, it is to be mutilated, deformation and shrink. Contrast to the CK, the peak positions of fluorescence of algae cells irradiated is similar to the whole while the peak light intensity alters. On irradiation of promoting dose, however, the auto fluorescence intensity is enhanced more than control. Conclusions: The method of cell stained can be used to observed genetic material in microalgae. There are obvious effects for laser irradiating to chloroplasts in cells, the bigger chloroplasts the greater fluorescence intensity. Physiological incentive effects of microalgae irradiated can be given expression on fluorescence characteristics and fluorescence intensity alteration of cells.

  3. A Study of the Use of the Three-Minute Classrooom Walk-Through Observation Method for Determining the Implementation of New Instructional Strategies

    ERIC Educational Resources Information Center

    Notgrass, Patty J.

    2012-01-01

    Principals are responsible for ensuring the effectiveness of the instructional programs, including staff development, on their campuses. Instructional leaders must utilize practices that allow them to fulfill this responsibility. This qualitative, collective case study examined the effectiveness of the three-minute classroom walk-through…

  4. Community Engagement in Observational Human Exposure Studies

    EPA Science Inventory

    Although observational human exposure studies do not deliberately expose participants to chemicals or environmental conditions, merely involving people as research participants and conducting research inside homes raises ethical issues. Community engagement offers a promising st...

  5. Measuring agreement between ratings interpretations and binary clinical interpretations of images: a simulation study of methods for quantifying the clinical relevance of an observer performance paradigm

    PubMed Central

    Chakraborty, Dev P.

    2012-01-01

    Laboratory receiver operating characteristic (ROC) studies, that are often used to evaluate medical imaging systems, differ from “live” clinical interpretations in several respects which could compromise their clinical relevance. The aim was to develop methodology for quantifying the clinical relevance of a laboratory ROC study. A simulator was developed to generate ROC ratings data and binary clinical interpretations classified as correct or incorrect for a common set of images interpreted under clinical and laboratory conditions. The area under the trapezoidal ROC curve was used as the laboratory figure-of-merit and the fraction of correct clinical decisions as the clinical figure-of-merit. Conventional agreement measures (Pearson, Spearman, Kendall and kappa) between the bootstrap-induced fluctuations of the two figures-of-merit were estimated. A jackknife pseudovalue transformation applied to the figures-of-merit was also investigated as a way to capture agreement existing at the individual image level that could be lost at the figure-of-merit level. It is shown that the pseudovalues define a relevance ROC curve the area under which (rAUC) measures the ability of the laboratory figure-of-merit based pseudovalues to correctly classify incorrect vs. correct clinical interpretations, and is a measure of the clinical relevance of an ROC study. The conventional measures and rAUC were compared under varying simulator conditions. It was found that design details of the ROC study, namely the number of bins, the difficulty level of the images, the ratio of disease-present to disease-absent images, and the unavoidable difference between laboratory and clinical performance levels, can seriously underestimate the agreement as indicated by conventional agreement measures, even for perfectly correlated data, while rAUC showed high agreement and was relatively immune to these details. At the same time rAUC was sensitive to factors such as intrinsic correlation between the laboratory and clinical decision variables and differences in reporting thresholds that are expected to influence agreement both at the individual image level and at the figure-of-merit level. Suggestions are made for how to conduct relevance ROC studies aimed at assessing agreement between laboratory and clinical interpretations. PMID:22516804

  6. A Numerical Climate Observing Network Design Study

    NASA Technical Reports Server (NTRS)

    Stammer, Detlef

    2003-01-01

    This project was concerned with three related questions of an optimal design of a climate observing system: 1. The spatial sampling characteristics required from an ARGO system. 2. The degree to which surface observations from ARGO can be used to calibrate and test satellite remote sensing observations of sea surface salinity (SSS) as it is anticipated now. 3. The more general design of an climate observing system as it is required in the near future for CLIVAR in the Atlantic. An important question in implementing an observing system is that of the sampling density required to observe climate-related variations in the ocean. For that purpose this project was concerned with the sampling requirements for the ARGO float system, but investigated also other elements of a climate observing system. As part of this project we studied the horizontal and vertical sampling characteristics of a global ARGO system which is required to make it fully complementary to altimeter data with the goal to capture climate related variations on large spatial scales (less thanAttachment: 1000 km). We addressed this question in the framework of a numerical model study in the North Atlantic with an 1/6 horizontal resolution. The advantage of a numerical design study is the knowledge of the full model state. Sampled by a synthetic float array, model results will therefore allow to test and improve existing deployment strategies with the goal to make the system as optimal and cost-efficient as possible. Attachment: "Optimal observations for variational data assimilation".

  7. Parent–child interactions and anxiety disorders: an observational study

    Microsoft Academic Search

    Jennifer L Hudson; Ronald M Rapee

    2001-01-01

    Past research has indicated a potential link between anxiety and parenting styles that are characterised by control and rejection. However, few studies have utilised observational methods to support these findings. In the current study, mother–child interactions were observed while the child completed two difficult cognitive tasks. The sample consisted of clinically anxious children (n=43), oppositional defiant children (n=20) and non-clinical

  8. Concatenation of Observed Grasp Phases with Observer’s Distal Movements: A Behavioural and TMS Study

    PubMed Central

    De Stefani, Elisa; Innocenti, Alessandro; De Marco, Doriana; Gentilucci, Maurizio

    2013-01-01

    The present study aimed at determining how actions executed by two conspecifics can be coordinated with each other, or more specifically, how the observation of different phases of a reaching-grasping action is temporary related to the execution of a movement of the observer. Participants observed postures of initial finger opening, maximal finger aperture, and final finger closing of grasp after observation of an initial hand posture. Then, they opened or closed their right thumb and index finger (experiments 1, 2 and 3). Response times decreased, whereas acceleration and velocity of actual finger movements increased when observing the two late phases of grasp. In addition, the results ruled out the possibility that this effect was due to salience of the visual stimulus when the hand was close to the target and confirmed an effect of even hand postures in addition to hand apparent motion due to the succession of initial hand posture and grasp phase. In experiments 4 and 5, the observation of grasp phases modulated even foot movements and pronunciation of syllables. Finally, in experiment 6, transcranial magnetic stimulation applied to primary motor cortex 300 ms post-stimulus induced an increase in hand motor evoked potentials of opponens pollicis muscle when observing the two late phases of grasp. These data suggest that the observation of grasp phases induced simulation which was stronger during observation of finger closing. This produced shorter response times, greater acceleration and velocity of the successive movement. In general, our data suggest best concatenation between two movements (one observed and the other executed) when the observed (and simulated) movement was to be accomplished. The mechanism joining the observation of a conspecific’s action with our own movement may be precursor of social functions. It may be at the basis for interactions between conspecifics, and related to communication between individuals. PMID:24278395

  9. Observational and interventional study design types; an overview

    PubMed Central

    Thiese, Matthew S.

    2014-01-01

    The appropriate choice in study design is essential for the successful execution of biomedical and public health research. There are many study designs to choose from within two broad categories of observational and interventional studies. Each design has its own strengths and weaknesses, and the need to understand these limitations is necessary to arrive at correct study conclusions. Observational study designs, also called epidemiologic study designs, are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods. Observational study designs include ecological designs, cross sectional, case-control, case-crossover, retrospective and prospective cohorts. An important subset of observational studies is diagnostic study designs, which evaluate the accuracy of diagnostic procedures and tests as compared to other diagnostic measures. These include diagnostic accuracy designs, diagnostic cohort designs, and diagnostic randomized controlled trials. Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease. Each study design has specific outcome measures that rely on the type and quality of data utilized. Additionally, each study design has potential limitations that are more severe and need to be addressed in the design phase of the study. This manuscript is meant to provide an overview of study design types, strengths and weaknesses of common observational and interventional study designs. PMID:24969913

  10. Social Studies: Issues and Methods.

    ERIC Educational Resources Information Center

    Dynneson, Thomas L.

    This competency based workbook in social studies education provides information on developing teaching strategies and instructional materials. Designed for undergraduate students in social studies, student teachers, and methods instructors, it serves as a source of assignments for students, a guide in testing student competencies in social studies

  11. ON THINNING METHODS FOR DATA ASSIMILATION OF SATELLITE OBSERVATIONS

    E-print Network

    Reiterer, Harald

    observational data with a background model to produce initial states of the atmosphere for numerical weather for numer- ical weather forecast. In this work we modify and improve the scheme of so-called estimation the observation density and the resolution of the model grid. Their theoretical study shows that the analysis

  12. Observer ratings of neighborhoods: comparison of two methods

    PubMed Central

    2013-01-01

    Background Although neighborhood characteristics have important relationships with health outcomes, direct observation involves imperfect measurement. The African American Health (AAH) study included two observer neighborhood rating systems (5-item Krause and 18-item AAH Neighborhood Assessment Scale [NAS]), initially fielded at two different waves. Good measurement characteristics were previously shown for both, but there was more rater variability than desired. In 2010 both measures were re-fielded together, with enhanced training and field methods implemented to decrease rater variability while maintaining psychometric properties. Methods AAH included a poor inner city and more heterogeneous suburban areas. Four interviewers rated 483 blocks, with 120 randomly-selected blocks rated by two interviewers. We conducted confirmatory factor analysis of scales and tested the Krause (5-20 points), AAH 18-item NAS (0-28 points), and a previous 7-item and new 5-item versions of the NAS (0-17 points, 0-11 points). Retest reliability for items (kappa) and scales (Intraclass Correlation Coefficient [ICC]) were calculated overall and among pre-specified subgroups. Linear regression assessed interviewer effects on total scale scores and assessed concurrent validity on lung and lower body functions. Mismeasurement effects on self-rated health were also assessed. Results Scale scores were better in the suburbs than in the inner city. ICC was poor for the Krause scale (ICC=0.19), but improved if the retests occurred within 10 days (ICC=0.49). The 7- and 5-item NAS scales had better ICCs (0.56 and 0.62, respectively), and were higher (0.71 and 0.73) within 10 days. Rater variability for the Kraus and 5- and 7-item NAS scales was 1-3 points (compared to the supervising rater). Concurrent validity was modest, with residents living in worse neighborhood conditions having worse function. Unadjusted estimates were biased towards the null compared with measurement-error corrected estimates. Conclusions Enhanced field protocols and rater training did not improve measurement quality. Specifically, retest reliability and interviewer variability remained problematic. Measurement error partially reduced, but did not eliminate concurrent validity, suggesting there are robust associations between neighborhood characteristics and health outcomes. We conclude that the 5-item AAH NAS has sufficient reliability and validity for further use. Additional research on the measurement properties of environmental rating methods is encouraged. PMID:24168373

  13. STRengthening analytical thinking for observational studies: the STRATOS initiative.

    PubMed

    Sauerbrei, Willi; Abrahamowicz, Michal; Altman, Douglas G; le Cessie, Saskia; Carpenter, James

    2014-12-30

    The validity and practical utility of observational medical research depends critically on good study design, excellent data quality, appropriate statistical methods and accurate interpretation of results. Statistical methodology has seen substantial development in recent times. Unfortunately, many of these methodological developments are ignored in practice. Consequently, design and analysis of observational studies often exhibit serious weaknesses. The lack of guidance on vital practical issues discourages many applied researchers from using more sophisticated and possibly more appropriate methods when analyzing observational studies. Furthermore, many analyses are conducted by researchers with a relatively weak statistical background and limited experience in using statistical methodology and software. Consequently, even 'standard' analyses reported in the medical literature are often flawed, casting doubt on their results and conclusions. An efficient way to help researchers to keep up with recent methodological developments is to develop guidance documents that are spread to the research community at large. These observations led to the initiation of the strengthening analytical thinking for observational studies (STRATOS) initiative, a large collaboration of experts in many different areas of biostatistical research. The objective of STRATOS is to provide accessible and accurate guidance in the design and analysis of observational studies. The guidance is intended for applied statisticians and other data analysts with varying levels of statistical education, experience and interests. In this article, we introduce the STRATOS initiative and its main aims, present the need for guidance documents and outline the planned approach and progress so far. We encourage other biostatisticians to become involved. PMID:25074480

  14. Testing Fractal Methods on Observed and Simulated Solar Magnetograms

    NASA Technical Reports Server (NTRS)

    Adams, M.; Falconer, D. A.; Lee, J. K.; Jones, C.

    2003-01-01

    The term "magnetic complexity" has not been sufficiently quantified. To accomplish this, we must understand the relationship between the observed magnetic field of solar active regions and fractal dimension measurements. Using data from the Marshall Space Flight Center's vector magnetograph ranging from December 1991 to July 2001, we compare the results of several methods of calculating a fractal dimension, e.g., Hurst coefficient, the Higuchi method, power spectrum, and 2-D Wavelet Packet Analysis. In addition, we apply these methods to synthetic data, beginning with representations of very simple dipole regions, ending with regions that are magnetically complex.

  15. Method for observing phase objects without halos and directional shadows

    NASA Astrophysics Data System (ADS)

    Suzuki, Yoshimasa; Kajitani, Kazuo; Ohde, Hisashi

    2015-03-01

    A new microscopy method for observing phase objects without halos and directional shadows is proposed. The key optical element is an annular aperture at the front focal plane of a condenser with a larger diameter than those used in standard phase contrast microscopy. The light flux passing through the annular aperture is changed by the specimen's surface profile and then passes through an objective and contributes to image formation. This paper presents essential conditions for realizing the method. In this paper, images of colonies formed by induced pluripotent stem (iPS) cells using this method are compared with the conventional phase contrast method and the bright-field method when the NA of the illumination is small to identify differences among these techniques. The outlines of the iPS cells are clearly visible with this method, whereas they are not clearly visible due to halos when using the phase contrast method or due to weak contrast when using the bright-field method. Other images using this method are also presented to demonstrate a capacity of this method: a mouse ovum and superimposition of several different images of mouse iPS cells.

  16. Earth Observing System: Global Observations to Study the Earth's Environment

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2001-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During the last couple of years, four EOS science missions were launched, representing observations of (1) total solar irradiance, (2) Earth radiation budget, (3) land cover & land use change, (4) ocean processes (vector wind, sea surface temperature, and ocean color), (5) atmospheric processes (aerosol and cloud properties, water vapor, and temperature and moisture profiles), and (6) tropospheric chemistry. In succeeding years many more satellites will be launched that will contribute immeasurably to our understanding of the Earth's environment. In this presentation I will describe how scientists are using NASA's Earth science data to examine land use and natural hazards, environmental air quality, including dust storms over the world's deserts, cloud and radiation properties, sea surface temperature, and winds over the ocean.

  17. Mobile vehicle road and weather observation quality check methods

    NASA Astrophysics Data System (ADS)

    Koller, Daniel Raymond

    Today State Departments of Transportation rely more and more on road weather data to make maintenance decisions. Inaccurate data can result in wrong treatment applications or inadequate staffing levels to maintain the roadway at the desired level of service. Previous methods of road condition data reporting have been limited to static in situ sensor stations. These road weather information systems (RWIS) provide varied data about precipitation, winds, temperature, and more, but their siting does not always provide an accurate representation of weather and road conditions along the roadway. The use of mobile data collection from vehicles travelling the highway corridors may assist in the locations where RWIS sitings are sparse or non-existent. The United States Department of Transporation's "Connected Vehicle" (formally IntelliDrive) research project is designed to create a fully connected transportation system providing road and weather data collection from an extensive array of vehicles. While the implementation of Connected Vehicle is in the future, some of the theories and technologies are already in place today. Several states, as a part of the Pooled Fund Study Maintenance Decision Support System (MDSS), have equipped their winter maintenance vehicles with Mobile Data Collection Automated / Vehicle Location (MDC/AVL) systems. In addition, since 1996, automobiles sold in the United States are required to be equipped with an Onboard Diagnostic Version 2 (OBDII) port that streams live data from sensors located in and around the vehicle. While these sensors were designed for vehicle diagnostics, some of the data can be used to determine weather characteristics around the vehicle. The OBDII data can be collected by a smartphone and sent to a server in real time to be processed. These mobile systems may fill the information gap along the roads that stationary environmental sensor stations are not able to collect. Particular concern and care needs to be focused on data quality and accuracy, requiring the development of quality checks for mobile data collection. Using OBDII-equipped automobiles and mobile collection methods, we can begin to address issues of data quality by understanding, characterizing, and demonstrating the quality of mobile system observations from operational and research environments. Several forms of quality checking can be used, including range checks, Barnes spatial checks, comparing vehicle data to road weather models, and applying Clarus quality check methodologies and algorithms to mobile observations. Development of these quality checks can lead to the future integration of mobile data into the Clarus system, data implementation for improved forecasting, maintenance decision support, and traveler safety. This paper will discuss the benefits and challenges in mobile data collection, along with how the development and implementation of a system of quality checks will improve the quality and accuracy of mobile data collection.

  18. An observational assessment method for aging laboratory rats

    EPA Science Inventory

    The growth of the aging population highlights the need for laboratory animal models to study the basic biological processes ofaging and susceptibility to toxic chemicals and disease. Methods to evaluate health ofaging animals over time are needed, especially efficient methods for...

  19. Computational observers and visualization methods for stereoscopic medical imaging.

    PubMed

    Zafar, Fahad; Yesha, Yaacov; Badano, Aldo

    2014-09-22

    As stereoscopic display devices become common, their image quality assessment evaluation becomes increasingly important. Most studies conducted on 3D displays are based on psychophysics experiments with humans rating their experience based on detection tasks. The physical measurements do not map to effects on signal detection performance. Additionally, human observer study results are often subjective and difficult to generalize. We designed a computational stereoscopic observer approach inspired by the mechanisms of stereopsis in human vision for task-based image assessment that makes binary decisions based on a set of image pairs. The stereo-observer is constrained to a left and a right image generated using a visualization operator to render voxel datasets. We analyze white noise and lumpy backgrounds using volume rendering techniques. Our simulation framework generalizes many different types of model observers including existing 2D and 3D observers as well as providing flexibility to formulate a stereo model observer approach following the principles of stereoscopic viewing. This methodology has the potential to replace human observer studies when exploring issues with stereo display devices to be used in medical imaging. We show results quantifying the changes in performance when varying stereo angle as measured by an ideal linear stereoscopic observer. Our findings indicate that there is an increase in performance of about 13-18% for white noise and 20-46% for lumpy backgrounds, where the stereo angle is varied from 0 to 30. The applicability of this observer extends to stereoscopic displays used for in the areas of medical and entertainment imaging applications. PMID:25321697

  20. The Geyser Observation and Study Association

    NSDL National Science Digital Library

    The Geyser Observation and Study Association is a non-profit scientific and educational corporation who's purpose is the "collection and dissemination of information about geysers and other geothermal phenomena in Yellowstone National Park and elsewhere". The Web site has descriptions and photographs of geysers from around the world with an emphasis on Yellowstone and Old Faithful. Other features include recent and historical geyser activity information, a glossary of geyser terms, an index to geysers described on the site, a "guess the geyser" game, and other interesting links round out the site nicely.

  1. Lagrangian methods for observation of intrathermocline eddies in ocean

    NASA Astrophysics Data System (ADS)

    Filyushkin, B. N.; Sokolovskiy, M. A.; Kozhelupova, N. G.; Vagina, I. M.

    2014-11-01

    Intrathermocline anticyclonic eddies (lenses) of Mediterranean origin are regularly observed in the Eastern part of the Atlantic Ocean. These eddies are identified both from satellites as altimetry and seasurface temperature (SST) changes and according to data of neutral buoyancy floats (NBF) placed in the body of a lens. In this paper, in the framework of a three-layer quasi-geostrophic model, using the contour dynamics method, we consider some theoretical aspects of lens movement observations made by acoustic NBF and freely drifting buoys of the Argo project. Direct experimental observation data on the lenses' drift in the North Atlantic qualitatively confirmed the results of our numerical experiments. In particular, it is shown that the spin of the lens has an advective influence on the behavior of NBF at distances of several lens radii.

  2. Dietary assessment methods in epidemiologic studies

    PubMed Central

    Shim, Jee-Seon; Oh, Kyungwon; Kim, Hyeon Chang

    2014-01-01

    Diet is a major lifestyle-related risk factor of various chronic diseases. Dietary intake can be assessed by subjective report and objective observation. Subjective assessment is possible using open-ended surveys such as dietary recalls or records, or using closed-ended surveys including food frequency questionnaires. Each method has inherent strengths and limitations. Continued efforts to improve the accuracy of dietary intake assessment and enhance its feasibility in epidemiological studies have been made. This article reviews common dietary assessment methods and their feasibility in epidemiological studies. PMID:25078382

  3. Reported Significant Observation (RSO) studies. Revision 1

    SciTech Connect

    Eicher, R.W.

    1992-12-01

    The Reported Significant Observation (RSO) study used in the field of safety is an information-gathering technique where employee-participants describe situations they have personally witnessed involving good and bad practices and safe and unsafe conditions. This information is useful in the risk assessment process because it focuses on hazards and thereby facilitates their elimination. However, RSO cannot be the only component in a risk assessment program. Used by the Air Force in their aviation psychology program and further developed by John C. Flanagan, RSO is more commonly known as the ``Critical Incident Technique.`` However, the words ``Critical`` and ``Incident`` had other connotations in nuclear safety, prompting early users within the Aerojet Nuclear Company to coin the more fitting title of ``Reported Significant Observations.`` The technique spread slowly in the safety field primarily because the majority of users were researchers interested in after-the-fact data, with application to everyday problems and behavioral factors. RSO was formally recognized as a significant hazard reduction tool during the development of the Management Oversight and Risk Tree (MORT) program for the US Atomic Energy Commission. The Department of Energy (DOE) has, in turn, adopted MORT for its system safety program, and this has resulted in RSO being a modern and viable technique for DOE contractor safety programs.

  4. Observational studies of drizzle in marine stratocumulus

    NASA Astrophysics Data System (ADS)

    Rossiter, Dione Lee

    The most expansive and persistent clouds, reducing the net radiation balance on a annually averaged global basis by ˜15 W/m2, are the low-lying marine stratocumulus (MSc) which hover over the eastern subtropical oceans. Despite their climatic importance, key processes and feedbacks within the MSc regime have yet to be fully quantified or understood. The goal of this research is to improve our understanding of MSc processes and their impact on the marine boundary layer (MBL). Specifically, using in situ aircraft cloud microphysical measurements, this research pays particular attention to the process of drizzle, the sedimentation of liquid water. Data utilized in this study primarily come from the Artium Flight Phase Doppler Interferometer (F/PDI) and the Cloud Imaging Probe (CIP) during four days of the Marine Stratus Experiment (MASE) in July 2005 in the northeastern Pacific near Monterey, California. Results presented in this dissertation are especially unique because of the broad and continuous range in which the F/PDI samples (2-100 mum diameter), a size range measured by no other instrument alone with the same resolution and accuracy. The upper portion of this size range, ˜30 to 100 mum, is of particular importance to the initiation and evolution of drizzle but traditionally, has been difficult to measure well. The first goal of this research was to characterize in-cloud drizzle during the four MASE days by exploring the horizontal and vertical structure of drizzle. Drizzle statistics indicate two microphysical regimes exist, a high drizzle regime, associated with patches of heavy drizzle occurring in clusters, and a low drizzle regime, associated with more uniform, light-to-no drizzle. Heavy drizzle regimes exhibit significant drop growth by collision-coalescence while low drizzle regimes exhibit drop growth primarily from condensation. The second goal of this research is to quantify the effects of drizzle on the MBL via the process of evaporation. The observations indicate a large range of BL cooling exists among the four study days. Sub-cloud profiles of evaporative cooling show variability in the location of peak and total depth of cooling. Variability is also found to exist in the horizontal. Lastly, cloud top (CT) processes which may be responsible for the initiation of drizzle during the heavy drizzle days are investigated. We utilize drop size distribution (DSD) measured from CIP/PDI and derived from box model simulations to calculate CT collision rates. We found the observational collision rates follow a power law with the observed slope, m , varying at CT between well-developed and less-developed drizzling MSc. No correlations between m and other observed cloud properties were found. Drop size distributions simulated from a box model of collision-coalescence suggest that while collision rates can be impacted by properties such as turbulence and cloud drop residence time, realistic values were insufficient to reproduce observed CT collision rates.

  5. Using video-based observation research methods in primary care health encounters to evaluate complex interactions

    PubMed Central

    Asan, Onur; Montague, Enid

    2015-01-01

    Objective The purpose of this paper is to describe the use of video-based observation research methods in primary care environment and highlight important methodological considerations and provide practical guidance for primary care and human factors researchers conducting video studies to understand patient-clinician interaction in primary care settings. Methods We reviewed studies in the literature which used video methods in health care research and, we also used our own experience based on the video studies we conducted in primary care settings. Results This paper highlighted the benefits of using video techniques such as multi-channel recording and video coding and compared “unmanned” video recording with the traditional observation method in primary care research. We proposed a list, which can be followed step by step to conduct an effective video study in a primary care setting for a given problem. This paper also described obstacles researchers should anticipate when using video recording methods in future studies. Conclusion With the new technological improvements, video-based observation research is becoming a promising method in primary care and HFE research. Video recording has been under-utilized as a data collection tool because of confidentiality and privacy issues. However, it has many benefits as opposed to traditional observations, and recent studies using video recording methods have introduced new research areas and approaches. PMID:25479346

  6. Five Methods to Score the Teacher Observation of Classroom Adaptation Checklist and to Examine Group Differences

    ERIC Educational Resources Information Center

    Wang, Ze; Rohrer, David; Chuang, Chi-ching; Fujiki, Mayo; Herman, Keith; Reinke, Wendy

    2015-01-01

    This study compared 5 scoring methods in terms of their statistical assumptions. They were then used to score the Teacher Observation of Classroom Adaptation Checklist, a measure consisting of 3 subscales and 21 Likert-type items. The 5 methods used were (a) sum/average scores of items, (b) latent factor scores with continuous indicators, (c)…

  7. Development of acoustic observation method for seafloor hydrothermal flows

    NASA Astrophysics Data System (ADS)

    Mochizuki, M.; Tamura, H.; Asada, A.; Kinoshita, M.; Tamaki, K.

    2012-12-01

    In October 2009, we conducted seafloor reconnaissance using a manned deep-sea submersible Shinkai6500 in Central Indian Ridge 18-20deg.S, where hydrothermal plume signatures were previously perceived. Acoustic video camera "DIDSON" was equipped on the top of Shinkai6500 in order to get acoustic video images of hydrothermal plumes. The acoustic video images of the hydrothermal plumes had been captured in three of seven dives. We could identify shadings inside the acoustic video images of the hydrothermal plumes. Silhouettes of the hydrothermal plumes varied from second to second, and the shadings inside them also varied. These variations corresponded to internal structures and flows of the plumes. DIDSON (Dual-Frequency IDentification SONar) is acoustic lens-based sonar. It has sufficiently high resolution and rapid refresh rate that it can substitute for optical system in turbid or dark water where optical systems fail. Ins. of Industrial Science, University of Tokyo has understood DIDSON's superior performance and tried to develop a new observation method based on DIDSON for hydrothermal discharging from seafloor vent. We expected DIDSON to reveal whole image of hydrothermal plume as well as detail inside the plume. The proposed method to observe and measure hydrothermal flow is the one to utilize a sheet-like acoustic beam. Scanning with concentrated acoustic beam gives distances to the edges of the hydrothermal flows. And then, the shapes of the flows can be identified even in low and zero visibility conditions. Tank experiment was conducted. The purposes of this experiment were to make an attempt at proposed method to delineate underwater hydrothermal flows and to understand relationships among acoustic video image, flow rate and water temperature. Water was heated in the hot tub and pumped to the water tank through the silicon tube. We observed water flows discharging from the tip of the tube with DIDSON. Flow rate had been controlled and temperatures of the discharging water and background water had been measured. 3D images of flows in the tank could be reconstructed with the proposed method. We will report the overview of the tank experiments, and discuss possibility of DIDSON as an observation tool for seafloor hydrothermal activity.

  8. Determination of Reference Catalogs for Meridian Observations Using Statistical Method

    NASA Astrophysics Data System (ADS)

    Li, Z. Y.

    2014-09-01

    The meridian observational data are useful for developing high-precision planetary ephemerides of the solar system. These historical data are provided by the jet propulsion laboratory (JPL) or the Institut De Mecanique Celeste Et De Calcul Des Ephemerides (IMCCE). However, we find that the reference systems (realized by the fundamental catalogs FK3 (Third Fundamental Catalogue), FK4 (Fourth Fundamental Catalogue), and FK5 (Fifth Fundamental Catalogue), or Hipparcos), to which the observations are referred, are not given explicitly for some sets of data. The incompleteness of information prevents us from eliminating the systematic effects due to the different fundamental catalogs. The purpose of this paper is to specify clearly the reference catalogs of these observations with the problems in their records by using the JPL DE421 ephemeris. The data for the corresponding planets in the geocentric celestial reference system (GCRS) obtained from the DE421 are transformed to the apparent places with different hypothesis regarding the reference catalogs. Then the validations of the hypothesis are tested by two kinds of statistical quantities which are used to indicate the significance of difference between the original and transformed data series. As a result, this method is proved to be effective for specifying the reference catalogs, and the missed information is determined unambiguously. Finally these meridian data are transformed to the GCRS for further applications in the development of planetary ephemerides.

  9. BAYESIAN SHRINKAGE METHODS FOR PARTIALLY OBSERVED DATA WITH MANY PREDICTORS*

    PubMed Central

    Boonstra, Philip S.; Mukherjee, Bhramar; Taylor, Jeremy MG

    2013-01-01

    Motivated by the increasing use of and rapid changes in array technologies, we consider the prediction problem of fitting a linear regression relating a continuous outcome Y to a large number of covariates X, eg measurements from current, state-of-the-art technology. For most of the samples, only the outcome Y and surrogate covariates, W, are available. These surrogates may be data from prior studies using older technologies. Owing to the dimension of the problem and the large fraction of missing information, a critical issue is appropriate shrinkage of model parameters for an optimal bias-variance tradeoff. We discuss a variety of fully Bayesian and Empirical Bayes algorithms which account for uncertainty in the missing data and adaptively shrink parameter estimates for superior prediction. These methods are evaluated via a comprehensive simulation study. In addition, we apply our methods to a lung cancer dataset, predicting survival time (Y) using qRT-PCR (X) and microarray (W) measurements. PMID:24436727

  10. Carbon Dioxide Observational Platform System (CO-OPS), feasibility study

    NASA Technical Reports Server (NTRS)

    Bouquet, D. L.; Hall, D. W.; Mcelveen, R. P.

    1987-01-01

    The Carbon Dioxide Observational Platform System (CO-OPS) is a near-space, geostationary, multi-user, unmanned microwave powered monitoring platform system. This systems engineering feasibility study addressed identified existing requirements such as: carbon dioxide observational data requirements, communications requirements, and eye-in-the-sky requirements of other groups like the Defense Department, the Forestry Service, and the Coast Guard. In addition, potential applications in: earth system science, space system sciences, and test and verification (satellite sensors and data management techniques) were considered. The eleven month effort is summarized. Past work and methods of gathering the required observational data were assessed and rough-order-of magnitude cost estimates have shown the CO-OPS system to be most cost effective (less than $30 million within a 10 year lifetime). It was also concluded that there are no technical, schedule, or obstacles that would prevent achieving the objectives of the total 5-year CO-OPS program.

  11. A processing method and results of meteor shower radar observations

    NASA Technical Reports Server (NTRS)

    Belkovich, O. I.; Suleimanov, N. I.; Tokhtasjev, V. S.

    1987-01-01

    Studies of meteor showers permit the solving of some principal problems of meteor astronomy: to obtain the structure of a stream in cross section and along its orbits; to retrace the evolution of particle orbits of the stream taking into account gravitational and nongravitational forces and to discover the orbital elements of its parent body; to find out the total mass of solid particles ejected from the parent body taking into account physical and chemical evolution of meteor bodies; and to use meteor streams as natural probes for investigation of the average characteristics of the meteor complex in the solar system. A simple and effective method of determining the flux density and mass exponent parameter was worked out. This method and its results are discussed.

  12. Observational constraints on well-posed reconstruction methods and the optimization-Grad-Rubin method

    NASA Astrophysics Data System (ADS)

    Amari, T.; Aly, J.-J.

    2010-11-01

    Context. Grad-Rubin type methods are interesting candidates for reconstructing the force-free magnetic field of a solar coronal region. As input these methods, however, require the normal component Bn of the field on the whole boundary of the numerical box and the force-free function ? on the part of the boundary where Bn > 0 (or Bn < 0), while observations provide data only on its lower photospheric part. Moreover, they introduce an unpleasing asymmetry between the opposite polarity parts of the boundary, and certainly do not take full advantage of the available data on ?. Aims: We address these issues resulting from observations. We present a possible way to supply the missing information about Bn and ? on the non-photospheric sides of the box, and to use more effectively the data provided by the measurements. Methods: We introduce the optimization-Grad-Rubin method (OGRM), which is in some sense midway between optimization methods and the standard Grad-Rubin methods. It is based on an iterative scheme in which the ? used as a boundary condition is imposed to take identical values at both footpoints of any field line and to be as close as possible to the ? provided by the measurements on the photosphere. The degree of “closeness” is measured by an “error functional” containing a weight function reflecting the confidence that can be placed on the observational data. Results: The new method is implemented in our code XTRAPOL, along with some technical improvements. It is thus tested for two specific choices of the weight function by reconstructing a force-free field from data obtained by perturbing in either a random or a non-random way boundary values provided by an exact solution.

  13. Alternating Renewal Process Models for Behavioral Observation: Simulation Methods, Software, and Validity Illustrations

    ERIC Educational Resources Information Center

    Pustejovsky, James E.; Runyon, Christopher

    2014-01-01

    Direct observation recording procedures produce reductive summary measurements of an underlying stream of behavior. Previous methodological studies of these recording procedures have employed simulation methods for generating random behavior streams, many of which amount to special cases of a statistical model known as the alternating renewal…

  14. Experimental land observing data system feasibility study

    NASA Technical Reports Server (NTRS)

    Buckley, J. L.; Kraiman, H.

    1982-01-01

    An end-to-end data system to support a Shuttle-based Multispectral Linear Array (MLA) mission in the mid-1980's was defined. The experimental Land Observing System (ELOS) is discussed. A ground system that exploits extensive assets from the LANDSAT-D Program to effectively meet the objectives of the ELOS Mission was defined. The goal of 10 meter pixel precision, the variety of data acquisition capabilities, and the use of Shuttle are key to the mission requirements, Ground mission management functions are met through the use of GSFC's Multi-Satellite Operations Control Center (MSOCC). The MLA Image Generation Facility (MIGF) combines major hardware elements from the Applications Development Data System (ADDS) facility and LANDSAT Assessment System (LAS) with a special purpose MLA interface unit. LANDSAT-D image processing techniques, adapted to MLA characteristics, form the basis for the use of existing software and the definition of new software required.

  15. Field Science Ethnography: Methods For Systematic Observation on an Expedition

    NASA Technical Reports Server (NTRS)

    Clancey, William J.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    The Haughton-Mars expedition is a multidisciplinary project, exploring an impact crater in an extreme environment to determine how people might live and work on Mars. The expedition seeks to understand and field test Mars facilities, crew roles, operations, and computer tools. I combine an ethnographic approach to establish a baseline understanding of how scientists prefer to live and work when relatively unemcumbered, with a participatory design approach of experimenting with procedures and tools in the context of use. This paper focuses on field methods for systematically recording and analyzing the expedition's activities. Systematic photography and time-lapse video are combined with concept mapping to organize and present information. This hybrid approach is generally applicable to the study of modern field expeditions having a dozen or more multidisciplinary participants, spread over a large terrain during multiple field seasons.

  16. Linking Indigenous Knowledge and Observed Climate Change Studies

    NASA Technical Reports Server (NTRS)

    Alexander, Chief Clarence; Bynum, Nora; Johnson, Liz; King, Ursula; Mustonen, Tero; Neofotis, Peter; Oettle, Noel; Rosenzweig, Cynthia; Sakakibara, Chie; Shadrin, Chief Vyacheslav; Vicarelli, Marta; Waterhouse, Jon; Weeks, Brian

    2010-01-01

    We present indigenous knowledge narratives and explore their connections to documented temperature and other climate changes and observed climate change impact studies. We then propose a framework for enhancing integration of these indigenous narratives of observed climate change with global assessments. Our aim is to contribute to the thoughtful and respectful integration of indigenous knowledge with scientific data and analysis, so that this rich body of knowledge can inform science, and so that indigenous and traditional peoples can use the tools and methods of science for the benefit of their communities if they choose to do so. Enhancing ways of understanding such connections are critical as the Intergovernmental Panel on Climate Change Fifth Assessment process gets underway.

  17. Pedagogical strategies used in clinical medical education: an observational study

    PubMed Central

    2010-01-01

    Background Clinical teaching is a complex learning situation influenced by the learning content, the setting and the participants' actions and interactions. Few empirical studies have been conducted in order to explore how clinical supervision is carried out in authentic situations. In this study we explore how clinical teaching is carried out in a clinical environment with medical students. Methods Following an ethnographic approach looking for meaning patterns, similarities and differences in how clinical teachers manage clinical teaching; non-participant observations and informal interviews were conducted during a four month period 2004-2005. The setting was at a teaching hospital in Sweden. The participants were clinical teachers and their 4th year medical students taking a course in surgery. The observations were guided by the aim of the study. Observational notes and notes from informal interviews were transcribed after each observation and all data material was analysed qualitatively. Results Seven pedagogical strategies were found to be applied, namely: 1) Questions and answers, 2) Lecturing, 3) Piloting, 4) Prompting, 5) Supplementing, 6) Demonstrating, and 7) Intervening. Conclusions This study contributes to previous research in describing a repertoire of pedagogical strategies used in clinical education. The findings showed that three superordinate qualitatively different ways of teaching could be identified that fit Ramsden's model. Each of these pedagogical strategies encompass different focus in teaching; either a focus on the teacher's knowledge and behaviour or the student's behaviour and understanding. We suggest that an increased awareness of the strategies in use will increase clinical teachers' teaching skills and the consequences they will have on the students' ability to learn. The pedagogical strategies need to be considered and scrutinized in further research in order to verify their impact on students' learning. PMID:20105340

  18. COMPARATIVE STUDY OF PLUME OPACITY MEASUREMENT METHODS

    EPA Science Inventory

    The opacity of smoke-stack emissions was measured by three methods at thirteen different plants and the results compared. The three opacity measurement methods are trained observer, in-stack transmissometer, and laser radar (lidar). The instrumental methods, lidar and in-stack tr...

  19. An Ergonomic Walkthrough Observation of Carpentry Tasks: A Pilot Study

    Microsoft Academic Search

    Amit Bhattacharya; Lisa Greathouse; James Warren; Yuhua Li; Mina Dimov; Harriet Applegate; Rick Stinson; Grace Lemasters

    1997-01-01

    The purpose of this pilot study was to determine the ergonomic risk factors for cumulative trauma disorders associated with carpentry tasks. Twenty-one union carpenters were observed on 29 occasions at 17 different construction sites. The job specialties observed were ceiling, drywall, and concrete form. A checklist for ergonomic walkthrough surveys was developed for this study. The carpenters were observed and

  20. A Parameter Identification Method to Determine Salinity of Sea Ice Using Temperature and Thickness Observations

    NASA Astrophysics Data System (ADS)

    Lv, Wei; Li, Xiaojiao; Feng, Enmin

    2014-02-01

    This study is intended to provide a parameter identification method to determine the salinity of sea ice using temperature and thickness measurements. This method is particularly effective when field data are sparse and unsatisfactory due to the difficulties associated with fieldwork, especially during the polar winter. The main idea of the method is described. The salinity profile is calculated by the temperature and thickness observations, which were measured at Nella Fjord around Zhongshan Station, Antarctica during the polar night time by the 22nd Chinese Antarctic Research Expedition. Another simulation for temperature profiles during a different measurement period is performed. Results show that better simulations of the salinity and temperature distributions are possible with the estimated parameters than with Eicken's and THESCI's methods. This method will help people to understand the salinity evolution of sea ice more thoroughly.

  1. The impact of consent on observational research: a comparison of outcomes from consenters and non consenters to an observational study

    Microsoft Academic Search

    Una Macleod; Graham CM Watt

    2008-01-01

    BACKGROUND: Public health benefits from research often rely on the use of data from personal medical records. When neither patient consent nor anonymisation is possible, the case for accessing such records for research purposes depends on an assessment of the probabilities of public benefit and individual harm. METHODS: In the late 1990s, we carried out an observational study which compared

  2. Material and Methods -Study sites

    E-print Network

    Hernández, José Carlos

    were always collected at the same lunar phase (after new moon-until full moon). The cellular changes us to study the gametogenic phases by examining sexual and nutritive cell in the tissues (Walker et

  3. OBSERVATIONS ON HABITS AND A METHOD OF TRAPPING

    E-print Network

    to publish the photographs of the channeled and knobbed whelk. STUDY AREA The study was conducted on Oyster Report--Fisheries No. 325 Washington, D. C. May 1960 #12;#12;CXDNTENTS Page Introduction 1 Study area 1 the majority of channeled \\v4ielks from oyster beds was designed and successfully tested on Oyster Pond River

  4. Observations of Epsilon Lyrae by the Video Drift Method

    NASA Astrophysics Data System (ADS)

    Wasson, Rick; Nelson, Nancy; Nelson, Eric; Buehlman, William; Wilson, Earl; Zapata, Deanna

    2015-01-01

    The major components of the famous "double-double" star Epsilon Lyrae, STF2382AB and STF2383CD, were measured by the Video Team at the Apple Valley Double Star Workshop in 2013, using the Video Drift Method. The results are in reasonable agreement with other recent measures and predictions of the latest orbital solutions.

  5. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 29, METHOD 624--PURGEABLES

    EPA Science Inventory

    The work which is described in the report was performed for the purpose of validating, through an interlaboratory study, Method 624 for the analysis of the volatile organic priority pollutants. This method is based on purging and concentration of the various analytes on an adsorb...

  6. Theory, Method, and Triangulation in the Study of Street Children.

    ERIC Educational Resources Information Center

    Lucchini, Riccardo

    1996-01-01

    Describes how a comparative study of street children in Montevideo (Uruguay), Rio de Janeiro, and Mexico City contributes to a synergism between theory and method. Notes how theoretical approaches of symbolic interactionism, genetic structuralism, and habitus theory complement interview, participant observation, and content analysis methods;…

  7. COMPARISON OF METHODS FOR THE ANALYSIS OF PANEL STUDIES

    EPA Science Inventory

    Three different methods of analysis of panels were compared using asthma panel data from a 1970-1971 study done by EPA in Riverhead, New York. The methods were (1) regression analysis using raw attack rates; (2) regression analysis using the ratio of observed attacks to expected ...

  8. The valuable contribution of observational studies to nephrology

    Microsoft Academic Search

    K J Jager; V S Stel; C Wanner; C Zoccali; F W Dekker

    2007-01-01

    In studies on the effects of therapy (or other interventions), the randomized controlled trial (RCT) is an almost unbeatable standard in clinical research. The value of RCTs leaves unabated the valuable contributions of observational studies to medicine. This paper discusses some limitations of RCTs providing examples where these are not possible, inappropriate, inadequate, or unnecessary. Thereafter, it focuses on observational

  9. In-Hospital Recruitment to Observational Studies of Stroke

    ERIC Educational Resources Information Center

    Pickering, Ruth M.; Kunkel, Dorit; Fitton, Carolyn; Ashburn, Ann; Jenkinson, Damian

    2010-01-01

    The objective of this study was to examine recruitment in three observational follow-up studies of patients with stroke, focusing on reasons for nonparticipation and the role of potential factors in explaining recruitment rates. It comprised secondary analysis of the three studies. Recruitment rates varied between the studies. Between 10 and 50%…

  10. Design of a practical model-observer-based image quality assessment method for CT imaging systems

    NASA Astrophysics Data System (ADS)

    Tseng, Hsin-Wu; Fan, Jiahua; Cao, Guangzhi; Kupinski, Matthew A.; Sainath, Paavana

    2014-03-01

    The channelized Hotelling observer (CHO) is a powerful method for quantitative image quality evaluations of CT systems and their image reconstruction algorithms. It has recently been used to validate the dose reduction capability of iterative image-reconstruction algorithms implemented on CT imaging systems. The use of the CHO for routine and frequent system evaluations is desirable both for quality assurance evaluations as well as further system optimizations. The use of channels substantially reduces the amount of data required to achieve accurate estimates of observer performance. However, the number of scans required is still large even with the use of channels. This work explores different data reduction schemes and designs a new approach that requires only a few CT scans of a phantom. For this work, the leave-one-out likelihood (LOOL) method developed by Hoffbeck and Landgrebe is studied as an efficient method of estimating the covariance matrices needed to compute CHO performance. Three different kinds of approaches are included in the study: a conventional CHO estimation technique with a large sample size, a conventional technique with fewer samples, and the new LOOL-based approach with fewer samples. The mean value and standard deviation of area under ROC curve (AUC) is estimated by shuffle method. Both simulation and real data results indicate that an 80% data reduction can be achieved without loss of accuracy. This data reduction makes the proposed approach a practical tool for routine CT system assessment.

  11. Method for analyzing electron spectra observed in solar neutrino experiments

    NASA Astrophysics Data System (ADS)

    Kwong, Waikwok; Rosen, S. P.

    1995-06-01

    The normalized spectral ratio (the ratio of the measured electron spectrum to that of the SSM with both spectra normalized to contain the same number of events) is used to study results from electron scattering and deuterium dissociation experiments. It is found to be a very useful tool for measuring the energy-dependent deviation from the SSM and results can be expressed in terms of a single parameter-its slope. The number of events needed to see a positive slope preferred by current data at the 3? level is about 4000-5000 for electron scattering experiments and about 2000 for deuterium dissociation experiments.

  12. Method for analyzing electron spectra observed in solar neutrino experiments.

    NASA Astrophysics Data System (ADS)

    Waikwok, Kwong; Rosen, S. P.

    1995-06-01

    The normalized spectral ratio (the ratio of the measured electron spectrum to that of the SSM with both spectra normalized to contain the same number of events) is used to study results from electron scattering and deuterium dissociation experiments. It is found to be a very useful tool for measuring the energy-dependent deviation from the SSM and results can be expressed in terms of a single parameter-its slope. The number of events needed to see a positive slope preferred by current data at the 3? level is about 4000 - 5000 for electron scattering experiments and about 2000 for deuterium dissociation experiments.

  13. A passive acoustic monitoring method applied to observation and group size estimation of finless porpoises.

    PubMed

    Wang, Kexiong; Wang, Ding; Akamatsu, Tomonari; Li, Songhai; Xiao, Jianqiang

    2005-08-01

    The present study aimed at determining the detection capabilities of an acoustic observation system to recognize porpoises under local riverine conditions and compare the results with sighting observations. Arrays of three to five acoustic data loggers were stationed across the main channel of the Tian-e-zhou Oxbow of China's Yangtze River at intervals of 100-150 m to record sonar signals of free-ranging finless porpoises (Neophocaena phocaenoides). Acoustic observations, concurrent with visual observations, were conducted at two occasions on 20-22 October 2003 and 17-19 October 2004. During a total of 42 h of observation, 316 finless porpoises were sighted and 7041 sonar signals were recorded by loggers. The acoustic data loggers recorded ultrasonic signals of porpoises clearly, and detected the presence of porpoises with a correct detection level of 77.6% and a false alarm level of 5.8% within an effective distance of 150 m. Results indicated that the stationed passive acoustic observation method was effective in detecting the presence of porpoises and showed potential in estimating the group size. A positive linear correlation between the number of recorded signals and the group size of sighted porpoises was indicated, although it is faced with some uncertainty and requires further investigation. PMID:16158672

  14. Towards an integrated observation and modeling system in the New York Bight using variational methods. Part II: Repressenter-based observing strategy evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Weifeng G.; Wilkin, John L.; Levin, Julia C.

    As part of an effort to build an integrated observation and modeling system for the New York Bight, this study explores observing strategy evaluation using a representer-based method. The representer of a single observation describes the covariance between the observed quantity and ocean state errors at all locations at any time within the assimilation window. It also describes the influence of the observation on control variable correction in a 4D variational data assimilation system. These properties hold for the combination of representers that is associated with a group of observations and functions of model variables that combines model variables (e.g. salt flux). The representer-based method is used here to identify which of a set of proposed tracks for an autonomous coastal glider is better for predicting horizontal salt flux within the Hudson Shelf Valley in a 2-day forecast period. The system is also used to compare different observation strategies. We show that a glider that traverses a regular transect influences a larger area than a continuously profiling mooring, but the mooring carries stronger influence at the observation location. The representer analysis shows how the information provided by observations extends toward the dynamically upstream and how increasing the duration of the analysis window captures more dynamical connections and expands the area of influence of the observations in data assimilation. Overall, the study demonstrates that the representer methodology can quantitatively contrast different observational strategies and determine spatial patterns and temporal extent of the influence of observations, both of which are helpful for evaluating the design of observation networks.

  15. Documenting Observations of Students in Mathematics: A Case Study.

    ERIC Educational Resources Information Center

    Wilson, Linda Dager

    This paper is the report of a year-long study of a mathematics teacher's attempts to document her observations of students. One goal of the project is to determine whether it is feasible for a teacher to keep a record of informal assessments such as observations and interviews. Another goal is to determine how useful such information could be to…

  16. An Observational Study of Skilled Memory in Waitresses.

    ERIC Educational Resources Information Center

    Stevens, Joy

    A two-phase study about skilled memory as it is used by waitresses included a participant-observer phase and an observational phase. Participants were three experienced waitresses who had worked at a midtown Manhattan restaurant for 14, 7, and 3 years respectively and a team of 5 confederate customers. Waitresses and customers wore microphones.…

  17. Learning from Reciprocal Peer Observation: A Collaborative Self-Study

    ERIC Educational Resources Information Center

    Pressick-Kilborn, Kimberley; te Riele, Kitty

    2008-01-01

    Engaging in a self-study is a multi-faceted activity that involves not only autobiography and theory, but also students and colleagues. Learning from and with colleagues can take many forms. This article discusses the authors' experience with reciprocal classroom observation in a teacher education context. Peer observation supported our learning…

  18. Feedback Gain Design Method for the Full-Order Flux Observer in Sensorless Control of Induction Motor

    Microsoft Academic Search

    Abderrahmane Bouhenna; Abdellah Mansouri; Mohammed Chenafa; Abdelkader Belaidi

    This paper deals with a feedback gain design method for the full-order flux observer with adaptive speed loop, which enables the minimizing the unstable operation region of this observer to a line in the torque-speed plane. The stability in regenerating mode is studied using necessary condition of stability based on de- terminant of matrix and a linearized model. Simulations results

  19. “Benchmark” — a large observational study of Ontario beef breeding herds: Study design and collection of data

    PubMed Central

    McDermott, John J.; Alves, David M.; Anderson, Neil G.; Martin, S. Wayne

    1991-01-01

    The methods used in a large field study which investigated the health and productivity of Ontario beef breeding herds are described. Beginning in the calving season of 1986, 180 breeding herds on 170 randomly sampled farms were followed for a two year period, using producer records and annual farm visits. The response (cooperation) rate among the eligible producers initially contacted was 70%. Approximately two-thirds of producers maintained individual animal records, primarily calving season records. Approximately 40% recorded disease occurrences. The advantages, disadvantages, and interpretation of “on-farm” observational studies are discussed. PMID:17423817

  20. Phase microscopy using light-field reconstruction method for cell observation.

    PubMed

    Xiu, Peng; Zhou, Xin; Kuang, Cuifang; Xu, Yingke; Liu, Xu

    2015-08-01

    The refractive index (RI) distribution can serve as a natural label for undyed cell imaging. However, the majority of images obtained through quantitative phase microscopy is integrated along the illumination angle and cannot reflect additional information about the refractive map on a certain plane. Herein, a light-field reconstruction method to image the RI map within a depth of 0.2?m is proposed. It records quantitative phase-delay images using a four-step phase shifting method in different directions and then reconstructs a similar scattered light field for the refractive sample on the focus plane. It can image the RI of samples, transparent cell samples in particular, in a manner similar to the observation of scattering characteristics. The light-field reconstruction method is therefore a powerful tool for use in cytobiology studies. PMID:25980387

  1. On a recursive method for the estimation of unknown parameters of partially observed chaotic systems

    NASA Astrophysics Data System (ADS)

    Mariño, Inés P.; Míguez, Joaquín

    2006-08-01

    We investigate a recently proposed method for on-line parameter estimation and synchronization in chaotic systems. This novel technique has been shown effective to estimate a single unknown parameter of a primary chaotic system with known functional form that is only partially observed through a scalar time series. It works by periodically updating the parameter of interest in a secondary system, with the same functional form as the primary one but no explicit coupling between their dynamic variables, in order to minimize a suitably defined cost function. In this paper, we review the basics of the method, and investigate its robustness and new extensions. In particular, we study the performance of the novel technique in the presence of noise (either observational, i.e., an additive contamination of the observed time series, or dynamical, i.e., a random perturbation of the system dynamics) and when there is a mismatch between the primary and secondary systems. Numerical results, including comparisons with other techniques, are presented. Finally, we investigate the extension of the original method to perform the estimation of two unknown parameters and illustrate its effectiveness by means of computer simulations.

  2. A double-observer method for reducing bias in faecal pellet surveys of forest ungulates

    USGS Publications Warehouse

    Jenkins, K.J.; Manly, B.F.J.

    2008-01-01

    1. Faecal surveys are used widely to study variations in abundance and distribution of forest-dwelling mammals when direct enumeration is not feasible. The utility of faecal indices of abundance is limited, however, by observational bias and variation in faecal disappearance rates that obscure their relationship to population size. We developed methods to reduce variability in faecal surveys and improve reliability of faecal indices. 2. We used double-observer transect sampling to estimate observational bias of faecal surveys of Roosevelt elk Cervus elaphus roosevelti and Columbian black-tailed deer Odocoileus hemionus columbianus in Olympic National Park, Washington, USA. We also modelled differences in counts of faecal groups obtained from paired cleared and uncleared transect segments as a means to adjust standing crop faecal counts for a standard accumulation interval and to reduce bias resulting from variable decay rates. 3. Estimated detection probabilities of faecal groups ranged from < 0.2-1.0 depending upon the observer, whether the faecal group was from elk or deer, faecal group size, distance of the faecal group from the sampling transect, ground vegetation cover, and the interaction between faecal group size and distance from the transect. 4. Models of plot-clearing effects indicated that standing crop counts of deer faecal groups required 34% reduction on flat terrain and 53% reduction on sloping terrain to represent faeces accumulated over a standard 100-day interval, whereas counts of elk faecal groups required 0% and 46% reductions on flat and sloping terrain, respectively. 5. Synthesis and applications. Double-observer transect sampling provides a cost-effective means of reducing observational bias and variation in faecal decay rates that obscure the interpretation of faecal indices of large mammal abundance. Given the variation we observed in observational bias of faecal surveys and persistence of faeces, we emphasize the need for future researchers to account for these comparatively manageable sources of bias before comparing faecal indices spatially or temporally. Double-observer sampling methods are readily adaptable to study variations in faecal indices of large mammals at the scale of the large forest reserve, natural area, or other forested regions when direct estimation of populations is problematic. ?? 2008 The Authors.

  3. Comparing Simulations and Observations of Galaxy Evolution: Methods for Constraining the Nature of Stellar Feedback

    NASA Astrophysics Data System (ADS)

    Hummels, Cameron

    Computational hydrodynamical simulations are a very useful tool for understanding how galaxies form and evolve over cosmological timescales not easily revealed through observations. However, they are only useful if they reproduce the sorts of galaxies that we see in the real universe. One of the ways in which simulations of this sort tend to fail is in the prescription of stellar feedback, the process by which nascent stars return material and energy to their immediate environments. Careful treatment of this interaction in subgrid models, so-called because they operate on scales below the resolution of the simulation, is crucial for the development of realistic galaxy models. Equally important is developing effective methods for comparing simulation data against observations to ensure galaxy models which mimic reality and inform us about natural phenomena. This thesis examines the formation and evolution of galaxies and the observable characteristics of the resulting systems. We employ extensive use of cosmological hydrodynamical simulations in order to simulate and interpret the evolution of massive spiral galaxies like our own Milky Way. First, we create a method for producing synthetic photometric images of grid-based hydrodynamical models for use in a direct comparison against observations in a variety of filter bands. We apply this method to a simulation of a cluster of galaxies to investigate the nature of the red-sequence/blue-cloud dichotomy in the galaxy color-magnitude diagram. Second, we implement several subgrid models governing the complex behavior of gas and stars on small scales in our galaxy models. Several numerical simulations are conducted with similar initial conditions, where we systematically vary the subgrid models, afterward assessing their efficacy through comparisons of their internal kinematics with observed systems. Third, we generate an additional method to compare observations with simulations, focusing on the tenuous circumgalactic medium. Informed by our previous studies, we investigate the sensitivity of this new mode of comparison to hydrodynamical subgrid prescription. Finally, we synthesize the results of these studies and identify future avenues of research.

  4. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 14, METHOD 604-PHENOLS

    EPA Science Inventory

    An interlaboratory study in which 20 laboratories participated was conducted to provide precision and accuracy statements for the proposed EPA Method 604-Phenols for measuring concentrations of the Category 8 chemicals phenol, 2,4-dimethylphenol, 2-chlorophenol, 4-chloro-3-methyl...

  5. Critical Appraisal of Mixed Methods Studies

    ERIC Educational Resources Information Center

    Heyvaert, Mieke; Hannes, Karin; Maes, Bea; Onghena, Patrick

    2013-01-01

    In several subdomains of the social, behavioral, health, and human sciences, research questions are increasingly answered through mixed methods studies, combining qualitative and quantitative evidence and research elements. Accordingly, the importance of including those primary mixed methods research articles in systematic reviews grows. It is…

  6. Teacher Effectiveness and Causal Inference in Observational Studies

    ERIC Educational Resources Information Center

    Rose, Roderick A.

    2013-01-01

    An important target of education policy is to improve overall teacher effectiveness using evidence-based policies. Randomized control trials (RCTs), which randomly assign study participants or groups of participants to treatment and control conditions, are not always practical or possible and observational studies using rigorous quasi-experimental…

  7. Assessing Harm Reduction Strategies: The Dilemma of Observational Studies

    Microsoft Academic Search

    Julie Bruneau; Eduardo Franco; Frangois Lamothe

    Paramount among the contributions of observational epidemiologic studies is the identification of determi- nants of medical and public health outcomes. Cohort and case-control studies are well suited to scan and identify a large spectrum of factors and behaviors potentially associated with human immunodeficiency virus (HIV) infection; and they are, therefore, instru- mental in the design of appropriate selective interven- tions

  8. Driving performance while using cell phones: an observational study

    Microsoft Academic Search

    Tova Rosenbloom

    2006-01-01

    IntroductionThrough spontaneous driving observations, this study sought to examine the impact of using a hands-free cell phone while driving on speed and safe gap keeping behaviors. The study also examined the association between the measure of disturbance created by using a cell phone and the driver's awareness of the disturbance.

  9. An observational study to evaluate micronutrient status during enteral feeding

    PubMed Central

    Johnson, T; Janes, S; MacDonald, A; Elia, M; Booth, I

    2002-01-01

    Background: There are few data on the optimal micronutrient composition of paediatric enteral feeds. The recent European Directive on Foods for Special Medical Purposes (1999/21/EC) did not distinguish between the composition of adult and paediatric feeds. Aims: To evaluate, in an open, observational study, the long term nutritional biochemistry of 12 children aged 1–6 years and/or 8–20 kg. Methods: The children were receiving at least 50% of their estimated average requirement (EAR) for energy from paediatric enteral formulae: 1.0 kcal/ml (Nutrison Paediatric Standard) or 1.5 kcal/ml (Nutrison Paediatric Energy Plus). Venous blood samples for trace elements, vitamins, and minerals were taken at study entry and six months later. Parents kept three day food and feed records every month. Results: Despite a median energy intake of only 75% EAR (range 52–158%), 67% (n = 8) achieved their reference nutrient intake (RNI) for all micronutrients. No significant micronutrient deficiencies were seen on blood analysis after six months. Eighty three per cent (n = 10) had vitamin B12 and 92% (n = 11) had copper intake >150% RNI. Fifty eight per cent (n = 7) had high plasma B12 (>733 µmol/l) and 75% (n = 9) had high serum copper (>22 µmol/l) concentrations. Conclusions: Children without excess losses maintain adequate micronutrient status on long term enteral feeding. Subjects had high blood concentrations of vitamin B12 and copper, and had high dietary intakes of these micronutrients. We suggest that the maximum nutrient guidelines for paediatric enteral feeds should be more clearly defined. PMID:12023170

  10. Evaluation of flow direction methods against field observations of overland flow dispersion

    NASA Astrophysics Data System (ADS)

    Orlandini, S.; Moretti, G.; Corticelli, M. A.; Santangelo, P. E.; Capra, A.; Rivola, R.; Albertson, J. D.

    2012-12-01

    Despite the broad effort made in grid-based distributed catchment modeling to account for planar overland flow dispersion, actual dispersion experienced by overland flow along a natural slope has not been measured so far, and the ability of terrain analysis methods to reproduce this dispersion has not been evaluated. In the present study, the D8, D8-LTD, D? -LTD, D? , MD? , and MD8 flow direction methods are evaluated against field observations of overland flow dispersion obtained from novel experimental methods. Thin flows of cold (2--10oC) water were released at selected points on a warmer (15--30oC) slope and individual overland flow patterns originating from each of these points were observed using a terrestrial laser scanner and a thermal imaging camera. Prior to each experimental water release, a ScanStation C10 terrestrial laser scanner by Leica Geosystems was used to acquire a point cloud having average density of 25~points/cm2. This point cloud was used to generate alternative grid-based digital elevation models having resolution h ranging from 1~cm to 2~m. During the experiments, an Avio Advanced Thermo TVS-500EX camera by Nippon Avionics was used to monitor land surface temperature with resolution better than 0.05oC. The overland flow patterns were also found to be discernible in terrestrial laser scanner reflectance signal acquired immediately following the flow experiments. Overland flow patterns were determined by considering contrasted temperature and reflectance of the dry and wetted land surface portions. Predicted propagation patterns and observed flow patterns were compared by considering the fractions of flow released at the point source that propagates through the grid cells. Predictions of these quantities were directly provided by flow direction methods and by related flow accumulation algorithms. Suitable data for the comparison were derived from observed overland flow patterns by assuming a uniform distribution of flow along each cross section. Planar overland flow dispersion is found to play an important role in the region lying immediately downslope of the point source, but attenuates rapidly as flow propagates downslope displaying a nearly constant width of about 50~cm. In contrast, existing dispersive flow direction methods are found to provide a continued dispersion with distance downslope. Predicted propagation patterns, for all methods considered here, depend critically on h. All methods are found to be poorly sensitive in extremely fine grids (h ? 2~cm), and to be poorly specific in coarse grids (h = 2~m). Satisfactory results are, however, obtained when h approaches the average flow width, with the best performances in terms of Pearson correlation coefficient displayed by the MD8 method in the finest grids (5~cm ? h ? 20~cm), and by the MD? , D? , and D? -LTD methods in the coarsest grids (20~cm < h ? 1~m). The results obtained in this study suggest further testing of terrain analysis methods with longer flow patterns and coarser grids. Scale issues affecting the relation between land surface microtopography, dispersion, and size of grid cells involved need then to be addressed to provide a hydrologic model of flow partitioning along the slope directions identified by terrain analysis methods.

  11. Capturing intraoperative process deviations using a direct observational approach: the glitch method

    PubMed Central

    Morgan, Lauren; Robertson, Eleanor; Hadi, Mohammed; Catchpole, Ken; Pickering, Sharon; New, Steve; Collins, Gary; McCulloch, Peter

    2013-01-01

    Objectives To develop a sensitive, reliable tool for enumerating and evaluating technical process imperfections during surgical operations. Design Prospective cohort study with direct observation. Setting Operating theatres on five sites in three National Health Service Trusts. Participants Staff taking part in elective and emergency surgical procedures in orthopaedics, trauma, vascular and plastic surgery; including anaesthetists, surgeons, nurses and operating department practitioners. Outcome measures Reliability and validity of the glitch count method; frequency, type, temporal pattern and rate of glitches in relation to site and surgical specialty. Results The glitch count has construct and face validity, and category agreement between observers is good (?=0.7). Redundancy between pairs of observers significantly improves the sensitivity over a single observation. In total, 429 operations were observed and 5742 glitches were recorded (mean 14 per operation, range 0–83). Specialty-specific glitch rates varied from 6.9 to 8.3/h of operating (ns). The distribution of glitch categories was strikingly similar across specialties, with distractions the commonest type in all cases. The difference in glitch rate between specialty teams operating at different sites was larger than that between specialties (range 6.3–10.5/h, p<0.001). Forty per cent of glitches occurred in the first quarter of an operation, and only 10% occurred in the final quarter. Conclusions The glitch method allows collection of a rich dataset suitable for analysing the changes following interventions to improve process safety, and appears reliable and sensitive. Glitches occur more frequently in the early stages of an operation. Hospital environment, culture and work systems may influence the operative process more strongly than the specialty. PMID:24282244

  12. Detecting surface runoff location in a small catchment using distributed and simple observation method

    NASA Astrophysics Data System (ADS)

    Dehotin, Judicaël; Breil, Pascal; Braud, Isabelle; de Lavenne, Alban; Lagouy, Mickaël; Sarrazin, Benoît

    2015-06-01

    Surface runoff is one of the hydrological processes involved in floods, pollution transfer, soil erosion and mudslide. Many models allow the simulation and the mapping of surface runoff and erosion hazards. Field observations of this hydrological process are not common although they are crucial to evaluate surface runoff models and to investigate or assess different kinds of hazards linked to this process. In this study, a simple field monitoring network is implemented to assess the relevance of a surface runoff susceptibility mapping method. The network is based on spatially distributed observations (nine different locations in the catchment) of soil water content and rainfall events. These data are analyzed to determine if surface runoff occurs. Two surface runoff mechanisms are considered: surface runoff by saturation of the soil surface horizon and surface runoff by infiltration excess (also called hortonian runoff). The monitoring strategy includes continuous records of soil surface water content and rainfall with a 5 min time step. Soil infiltration capacity time series are calculated using field soil water content and in situ measurements of soil hydraulic conductivity. Comparison of soil infiltration capacity and rainfall intensity time series allows detecting the occurrence of surface runoff by infiltration-excess. Comparison of surface soil water content with saturated water content values allows detecting the occurrence of surface runoff by saturation of the soil surface horizon. Automatic records were complemented with direct field observations of surface runoff in the experimental catchment after each significant rainfall event. The presented observation method allows the identification of fast and short-lived surface runoff processes at a small spatial and temporal resolution in natural conditions. The results also highlight the relationship between surface runoff and factors usually integrated in surface runoff mapping such as topography, rainfall parameters, soil or land cover. This study opens interesting prospects for the use of spatially distributed measurement for surface runoff detection, spatially distributed hydrological models implementation and validation at a reasonable cost.

  13. Development of a new data-processing method for SKYNET sky radiometer observations

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Nakajima, T.; Dubovik, O.; Campanelli, M.; Che, H.; Khatri, P.; Takamura, T.; Pandithurai, G.

    2012-11-01

    In order to reduce uncertainty in the estimation of Direct Aerosol Radiative Forcing (DARF), it is important to improve the estimation of the single scattering albedo (SSA). In this study, we propose a new data processing method to improve SSA retrievals for the SKYNET sky radiometer network, which is one of the growing number of networks of sun-sky photometers, such as NASA AERONET and others. There are several reports that SSA values from SKYNET have a bias compared to those from AERONET, which is regarded to be the most accurate due to its rigorous calibration routines and data quality and cloud screening algorithms. We investigated possible causes of errors in SSA that might explain the known biases through sensitivity experiments using a numerical model, and also using real data at the SKYNET sites at Pune (18.616° N/73.800° E) in India and Beijing (39.586° N/116.229° E) in China. Sensitivity experiments showed that an uncertainty of the order of ±0.03 in the SSA value can be caused by a possible error in the ground surface albedo or solid view angle assumed for each observation site. Another candidate for possible error in the SSA was found in cirrus contamination generated by imperfect cloud screening in the SKYNET data processing. Therefore, we developed a new data quality control method to get rid of low quality or cloud contamination data, and we applied this method to the real observation data at the Pune site in SKYNET. After applying this method to the observation data, we were able to screen out a large amount of cirrus-contaminated data and to reduce the deviation in the SSA value from that of AERONET. We then estimated DARF using data screened by our new method. The result showed that the method significantly reduced the difference of 5 W m-2 that existed between the SKYNET and AERONET values of DARF before screening. The present study also suggests the necessity of preparing suitable a priori information on the distribution of coarse particles ranging in radius between 10 ?m and 30 ?m for the analysis of heavily dust-laden atmospheric cases.

  14. Development of a new data-processing method for SKYNET sky radiometer observations

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Nakajima, T.; Dubovik, O.; Campanelli, M.; Che, H.; Khatri, P.; Takamura, T.; Pandithurai, G.

    2012-06-01

    In order to reduce uncertainty in the estimation of aerosol direct radiative forcing (DARF), it is important to improve the estimation of the single scattering albedo (SSA). In this study, we propose a new data-processing method to improve SSA retrievals for the SKYNET sky radiometer network, which is one of the growing number of networks of sun-sky photometers, such as NASA AERONET and others. There are several reports that SSA values from SKYNET have a bias compared to those from AERONET, which is regarded to be the most accurate due to its rigorous calibration routines. We investigated possible causes of errors in SSA that might explain the known biases through sensitivity experiments using a numerical model, and also using real data at the SKYNET sites at Pune (18.616° N/73.800° E) in India and Beijing (39.586° N/116.229° E) in China. Sensitivity experiments showed that an uncertainty of the order of ±0.03 in the SSA value can be caused by a possible error in the ground surface albedo or solid view angle assumed for each observation site. Another candidate for possible error in the SSA was found in cirrus contamination generated by imperfect cloud screening in the SKYNET data processing. Therefore, we developed a new data quality control method that eliminates these error sources, and we applied this method to the real observation data at the Pune site in SKYNET. After applying this method to the observation data, we were able to screen out a large amount of cirrus-contaminated data and to reduce the deviation in the SSA value from that of AERONET. We then estimated DARF using data screened by our new method. The result showed that the method significantly reduced the difference of 5 W m-2 that existed between the SKYNET and AERONET values of DARF before screening. The present study also suggests the necessity of preparing suitable a priori information on the distribution of coarse particles ranging in radius between 10 ?m and 30 ?m for the analysis of heavily dust-laden atmospheric cases.

  15. Evaluation of interrater reliability for posture observations in a field study.

    PubMed

    Burt, S; Punnett, L

    1999-04-01

    This paper examines the interrater reliability of a quantitative observational method of assessing non-neutral postures required by work tasks. Two observers independently evaluated 70 jobs in an automotive manufacturing facility, using a procedure that included observations of 18 postures of the upper extremities and back. Interrater reliability was evaluated using percent agreement, kappa, intraclass correlation coefficients and generalized linear mixed modeling. Interrater agreement ranged from 26% for right shoulder elevation to 99 for left wrist flexion, but agreement was at best moderate when using kappa. Percent agreement is an inadequate measure, because it does not account for chance, and can lead to inflated measures of reliability. The use of more appropriate statistical methods may lead to greater insight into sources of variability in reliability and validity studies and may help to develop more effective ergonomic exposure assessment methods. Interrater reliability was acceptable for some of the postural observations in this study. PMID:10098805

  16. An Observational Study of Algol-Type Binary System

    NASA Astrophysics Data System (ADS)

    Zhang, J.

    2015-01-01

    The Algol-Type binary systems are a subtype of binary systems. Their unique semi-detached structure leads to have abundant physical phenomena, including the dramatically distorted donor star, strong magnetic activities, various ways of mass transfer, the evolution stage quite different from that of single stars, and specific formation tracks. In this paper, we introduce the fundamental physics of light curves, as well as the models or programs used in the past. We show the influence of different parameters on the light curves, including the inclination, temperature, abundance, surface gravity, the third light, radius, orbital eccentricity, and the argument of periastron. Based on the current catalog of Algols, we investigate their statistic characteristics. We observe three Algols and analyze the data in detail. The results are as follows: (1)Our statistical analyses of Algols support the previous suggestion that most of the detached component stars are main sequence stars. The distribution of the mass ratio agrees to our calculated critical value of the mass ratio for Algols. We suggest that there could be a lower limit of the radius ratio. We also show that there are good correlations among the temperature, luminosity, radius, and the mass of the component stars. (2) The binary FG Gem is observed, and the data are analyzed. Based on the solutions of large combinations of the temperature and luminosity, we use a new age-comparing method to show that the FG Gem is a semi-detached system, and a new temperature-searching method to get a better estimate of the temperature of the detached component star. We suggest that a combination of the intermittent mass flow and the continuous magnetic braking can explain its orbital period change. (3) Taking the VV Vir as an example, we discuss some properties of the mass flow in a semi-detached binary. Some of them can reflect the common characteristics of the mass flows in the Algol systems, e.g., the radius of the mass flow is very small, so is its impact spot. If the mass transfer rate is high, the energy transfer rate can be comparable to the intrinsic luminosity of the detached component star. The position of the impact spot can be determined by the orbital period, mass ratio, and the dimensionless potential. The temperature of the impact spot is very high, and it can be directly reflected by the humps on the light curves. (4) We discover a rare Algol binary V753 Mon, which is just in the process of mass ratio inversion. The mass ratio of this binary is very close to one, and the key evolutional stage provides an important observational source for the theoretical studies of binary evolution. (5) We introduce the light curve models and the related physical factors, including the shape of the orbit, the shape of the stars, gravity brightening, atmosphere model, limb darkening, reflection effect, eclipse effect, the third body and its third light, dark spots and magnetic effect, hot spots, asteroseismology, atmospheric eclipse, and circumstellar matter. The light curve analysis programs are presented. We analyze the parameters and show the relevant results, including the orbital inclination, surface temperature, metal abundance, gravity acceleration, the third light, stellar radius (expressed by the surface potential), the eccentricity of the orbit, and anomaly.

  17. A Conceptual Study of Visual Training Methods.

    ERIC Educational Resources Information Center

    Aik, Chong-Tek

    2003-01-01

    Proposes a research study to investigate the effects of two visual training methods on the productivity of new workers on an assembly line at a wood products plant in Indonesia. Suggests that such a study would be useful to the managers in deciding what types of training would be most appropriate. (Contains 23 references.) (CAK)

  18. Observation impact estimation using a forecast sensitivity to observation (FSO) method in the global and east Asia regions

    NASA Astrophysics Data System (ADS)

    Kim, Sung-Min; Kim, Hyun Mee

    2013-04-01

    This study investigated the observation impact to the forecast for the summer and winter months (i.e., JJA 2011 and DJF 2011-2012) in the global and east Asia regions, using the forecast sensitivity to observation (FSO) tool in the Korea Meteorological Administration (KMA) Unified Model (UM). The SONDE, AIRCRAFT, SURFACE, BOGUS, NOAA ATOVS, MetOp2 ATOVS, IASI, AIRS, GPSRO, SSMIS, Communication, Ocean and Meteorological Satellite (COMS) of KMA, AMV of JMA, ESA, GEOS, MSG, and ASCAT observations were used to estimate the observation impact to the forecast. Overall each observation showed consistent contribution to the forecast error reduction for summer and winter months. In the global region, the observation impact to the forecast error reduction depended on the number of observations assimilated in the numerical model. The contribution of the SONDE to the forecast error reduction is the largest, followed by NOAA / MetOp2 ATOVS and IASI. In satellite sounding observations, the contribution of channel number 5, 6, 7 of NOAA AMSU-A and channel number 56-215, 271-280 of IASI to the forecast error reduction were large. In the east Asia region, the contribution of the SONDE to the forecast error reduction was the largest, similar to that in the global region. However, the contribution of the satellite data to the forecast error reduction was decreased when compared to that in the global region because of exception of millions of satellite observations located the ocean and southern hemisphere. Especially, Atmospheric Motion Vector (AMV) observations of COMS launched in 2009 showed the largest impact among several Imager sensors.

  19. Observational studies of transiting extrasolar planets (invited review)

    E-print Network

    Southworth, John

    2014-01-01

    The study of transiting extrasolar planets is only 15 years old, but has matured into a rich area of research. I review the observational aspects of this work, concentrating on the discovery of transits, the characterisation of planets from photometry and spectroscopy, the Homogeneous Studies project, starspots, orbital obliquities, and the atmospheric properties of the known planets. I begin with historical context and conclude with a glance to a future of TESS, CHEOPS, Gaia and PLATO.

  20. Special Section: Observational Studies Sampling Considerations for Disease Surveillance in

    E-print Network

    Clark, William R.

    chronic wasting disease in free-ranging deer (Odocoileus virginianus) as a simple illustration, we show(1):52­60; 2008) DOI: 10.2193/2007-317 KEY WORDS chronic wasting disease, disease detection, disease prevalenceSpecial Section: Observational Studies Sampling Considerations for Disease Surveillance in Wildlife

  1. Using observational pilot studies to test and improve lab packages

    Microsoft Academic Search

    Manoel G. Mendonça; Daniela Cruzes; Josemeire Dias; Maria Cristina Ferreira De Oliveira

    2006-01-01

    Controlled experiments are a key approach to evalua te and evolve our understanding of software engineering technologies. However, defining and running a controlled experiment is a difficult and error-prone task. This paper argues t hat one can significantly reduce the risks associated with defi ning a new controlled experiment by running a set of well-plan ned observational pilot studies aimed

  2. Studies of the observed and theoretical variations of atmospheric ozone

    NASA Technical Reports Server (NTRS)

    London, Julius

    1990-01-01

    The four related topics covered include: (1) distributions of total and upper atmospheric ozone and their time and space variations; (2) observed and theoretical models of the quasi-biennial oscillation (QBO) ozone variation; (3) radiative processes in the upper atmosphere; and (4) relations between ozone and solar variations. The results of these studies are presented. They come from twenty-three published papers.

  3. SABRE observations of Pi2 pulsations: case studies

    NASA Astrophysics Data System (ADS)

    Bradshaw, E. G.; Lester, M.

    1997-01-01

    The characteristics of substorm-associated Pi2 pulsations observed by the SABRE coherent radar system during three separate case studies are presented. The SABRE field of view is well positioned to observe the differences between the auroral zone pulsation signature and that observed at mid-latitudes. During the first case study the SABRE field of view is initially in the eastward electrojet, equatorward and to the west of the substorm-enhanced electrojet current. As the interval progresses, the western, upward field-aligned current of the substorm current wedge moves westward across the longitudes of the radar field of view. The westward motion of the wedge is apparent in the spatial and temporal signatures of the associated Pi2 pulsation spectra and polarisation sense. During the second case study, the complex field-aligned and ionospheric currents associated with the pulsation generation region move equatorward into the SABRE field of view and then poleward out of it again after the third pulsation in the series. The spectral content of the four pulsations during the interval indicate different auroral zone and mid-latitude signatures. The final case study is from a period of low magnetic activity when SABRE observes a Pi2 pulsation signature from regions equatorward of the enhanced substorm currents. There is an apparent mode change between the signature observed by SABRE in the ionosphere and that on the ground by magnetometers at latitudes slightly equatorward of the radar field of view. The observations are discussed in terms of published theories of the generation mechanisms for this type of pulsation. Different signatures are observed by SABRE depending on the level of magnetic activity and the position of the SABRE field of view relative to the pulsation generation region. A twin source model for Pi2 pulsation generation provides the clearest explanation of the signatures observed Acknowledgements. The authors are grateful to Prof. D. J. Southwood (Imperial College, London), J. C. Samson (University of Alberta, Edmonton), L. J. Lanzerotti (AT&T Bell Laboratories), A. Wolfe (New York City Technical College) and to Dr. M. Vellante (University of LÁquila) for helpful discussions. They also thank Dr. A. Meloni (Istituto Nazionale di Geofisica, Roma) who made available geomagnetic field observations from LÁquila Geomagnetic Observatory. This research activity at LÁquila is supported by MURST (40% and 60% contracts) and by GIFCO/CNR. Topical Editor K.-H. Glaßmeier thanks C. Waters and S. Fujita for their help in evaluating this paper.-> Correspondence to :P. Francia->

  4. An analytical method for predicting surface soil moisture from rainfall observations

    SciTech Connect

    Sale, Michael J [ORNL; Pan, Feifei [Georgia Institute of Technology; Peters-Lidard, C. D. [Georgia Institute of Technology

    2003-11-01

    A simple analytical method for estimating surface soil moisture directly from rainfall data is proposed and studied. Soil moisture dynamics are represented by a linear stochastic partial differential equation ( Entekhabi and Rodriguez-Iturbe, 1994 ). A diagnostic equation is derived from the soil moisture dynamics equation by eliminating the diffusion term. The derived daily soil moisture function is a time-weighted average of previous cumulative rainfall over a given period (e.g., >14 days). The advantage of this method is that information on the initial condition of soil moisture, which is often not available at all times and locations, is not needed. The loss coefficient in the diagnostic equation for soil moisture can be estimated from land surface characteristics and soil properties. The method for determining the averaging window size, the loss coefficient, and the infiltration coefficient are described and demonstrated. The soil moisture data observed during three field experiments, i.e., Monsoon'90, Washita'92, and SGP'97, are compared to the calculated soil moisture. The results indicate that the proposed method is robust and has the potential for useful soil moisture predictions.

  5. Results of Observational Studies: Analysis of Findings from the Nurses’ Health Study

    PubMed Central

    Tai, Vicky; Grey, Andrew; Bolland, Mark J.

    2014-01-01

    Background The role of observational studies in informing clinical practice is debated, and high profile examples of discrepancies between the results of observational studies and randomised controlled trials (RCTs) have intensified that debate. We systematically reviewed findings from the Nurses’ Health Study (NHS), one of the longest and largest observational studies, to assess the number and strength of the associations reported and to determine if they have been confirmed in RCTs. Methods We reviewed NHS publication abstracts from 1978–2012, extracted information on associations tested, and graded the strength of the reported effect sizes. We searched PubMed for RCTs or systematic reviews for 3 health outcomes commonly reported in NHS publications: breast cancer, ischaemic heart disease (IHD) and osteoporosis. NHS results were compared with RCT results and deemed concordant when the difference in effect sizes between studies was ?0.15. Findings 2007 associations between health outcomes and independent variables were reported in 1053 abstracts. 58.0% (1165/2007) were statistically significant, and 22.2% (445/2007) were neutral (no association). Among the statistically significant results that reported a numeric odds ratio (OR) or relative risk (RR), 70.5% (706/1002) reported a weak association (OR/RR 0.5–2.0), 24.5% (246/1002) a moderate association (OR/RR 0.25–0.5 or 2.0–4.0) and 5.0% (50/1002) a strong association (OR/RR ?0.25 or ?4.0). 19 associations reported in NHS publications for breast cancer, IHD and osteoporosis have been tested in RCTs, and the concordance between NHS and RCT results was low (?25%). Conclusions NHS publications contain a large number of analyses, the majority of which reported statistically significant but weak associations. Few of these associations have been tested in RCTs, and where they have, the agreement between NHS results and RCTs is poor. PMID:25330007

  6. Rationale and design of the multinational observational study assessing insulin use: the MOSAIc study

    PubMed Central

    2012-01-01

    Background Although consensus guidelines recommend insulin progression among patients with type 2 diabetes (T2DM) who fail to meet glycemic targets over time, many fewer patients are progressed than may benefit. We describe the rationale and design of the MOSAIc (Multinational Observational Study Assessing Insulin use) study, a multinational observational cohort study to identify patient-, physician, and health care environment-based factors associated with insulin progression for patients with T2DM in real-world practice. Methods/design We will enroll 4,500 patients with T2DM taking initial insulin therapy for ?3?months across 175 physician practice sites in 18 countries. Extensive demographic, clinical, and psychosocial data at the patient and physician level and practice site characteristics will be collected at baseline and regular intervals during a 24-month follow-up period. We will use a multivariable logistic regression model to identify predictors of insulin progression and highlight potential opportunities for health behavior intervention to improve insulin progression rates. Secondary outcomes include evaluating factors associated with glycemic control, hypoglycemia, and treatment adherence among patients who do and do not progress beyond their initial insulin therapy and exploring geographic heterogeneity in treatment. Discussion Practice site and patient recruitment began in 2011 and baseline data will be available in late 2012. The MOSAIC study’s longitudinal observational design as well as the breadth and depth of data will be used to explore and quantify predictors of insulin progression and to identify potential opportunities for health behavior intervention in order to improve T2DM treatment and clinical outcomes. PMID:22999494

  7. Observational and Theoretical Studies of Low-Mass Star Formation

    NASA Technical Reports Server (NTRS)

    Myers, Philip C.

    1998-01-01

    Under this grant we have pursued studies of low-mass star formation with observations of candidate star-forming regions, (1) to determine the incidence of "infall asymmetry" in the spectral lines from very red young stellar objects; (2) to make detailed maps of candidate infall regions to determine the spatial extent of their infall asymmetry; (3) to compare the spatial and velocity structure of candidate infall regions with single dish and interferometer resolution; and (4) to begin a program of observations of starless dense cores to detect the presence or absence of infall motions.

  8. A method for three-dimensional quantitative observation of the microstructure of biological samples

    NASA Astrophysics Data System (ADS)

    Wang, Pengfei; Chen, Dieyan; Ma, Wanyun; Wu, Hongxin; Ji, Liang; Sun, Jialin; Lv, Danyu; Zhang, Lu; Li, Ying; Tian, Ning; Zheng, Jinggao; Zhao, Fengying

    2009-07-01

    Contemporary biology has developed into the era of cell biology and molecular biology, and people try to study the mechanism of all kinds of biological phenomena at the microcosmic level now. Accurate description of the microstructure of biological samples is exigent need from many biomedical experiments. This paper introduces a method for 3-dimensional quantitative observation on the microstructure of vital biological samples based on two photon laser scanning microscopy (TPLSM). TPLSM is a novel kind of fluorescence microscopy, which has excellence in its low optical damage, high resolution, deep penetration depth and suitability for 3-dimensional (3D) imaging. Fluorescent stained samples were observed by TPLSM, and afterward the original shapes of them were obtained through 3D image reconstruction. The spatial distribution of all objects in samples as well as their volumes could be derived by image segmentation and mathematic calculation. Thus the 3-dimensionally and quantitatively depicted microstructure of the samples was finally derived. We applied this method to quantitative analysis of the spatial distribution of chromosomes in meiotic mouse oocytes at metaphase, and wonderful results came out last.

  9. The initial conditions of observed star clusters - I. Method description and validation

    E-print Network

    Pijloo, J T; Alexander, P E R; Gieles, M; Larsen, S S; Groot, P J; Devecchi, B

    2015-01-01

    We have coupled a fast, parametrized star cluster evolution code to a Markov Chain Monte Carlo code to determine the distribution of probable initial conditions of observed star clusters, which may serve as a starting point for future $N$-body calculations. In this paper we validate our method by applying it to a set of star clusters which have been studied in detail numerically with $N$-body simulations and Monte Carlo methods: the Galactic globular clusters M4, 47 Tucanae, NGC 6397, M22, $\\omega$ Centauri, Palomar 14 and Palomar 4, the Galactic open cluster M67, and the M31 globular cluster G1. For each cluster we derive a distribution of initial conditions that, after evolution up to the cluster's current age, evolves to the currently observed conditions. We find that there is a connection between the morphology of the distribution of initial conditions and the dynamical age of a cluster and that a degeneracy in the initial half-mass radius towards small radii is present for clusters which have undergone a...

  10. Inter-Observer Reliability Assessments in Time Motion Studies: The Foundation for Meaningful Clinical Workflow Analysis

    PubMed Central

    Lopetegui, Marcelo A.; Bai, Shasha; Yen, Po-Yin; Lai, Albert; Embi, Peter; Payne, Philip R.O.

    2013-01-01

    Understanding clinical workflow is critical for researchers and healthcare decision makers. Current workflow studies tend to oversimplify and underrepresent the complexity of clinical workflow. Continuous observation time motion studies (TMS) could enhance clinical workflow studies by providing rich quantitative data required for in-depth workflow analyses. However, methodological inconsistencies have been reported in continuous observation TMS, potentially reducing the validity of TMS’ data and limiting their contribution to the general state of knowledge. We believe that a cornerstone in standardizing TMS is to ensure the reliability of the human observers. In this manuscript we review the approaches for inter-observer reliability assessment (IORA) in a representative sample of TMS focusing on clinical workflow. We found that IORA is an uncommon practice, inconsistently reported, and often uses methods that provide partial and overestimated measures of agreement. Since a comprehensive approach to IORA is yet to be proposed and validated, we provide initial recommendations for IORA reporting in continuous observation TMS. PMID:24551381

  11. Comparison of protein expression ratios observed by sixplex and duplex TMT labeling method

    PubMed Central

    Rauniyar, Navin; Gao, Benbo; McClatchy, Daniel B.; Yates, John R.

    2013-01-01

    Stable isotope labeling via isobaric derivatization of peptides is a universally applicable approach that enables concurrent identification and quantification of proteins in different samples using tandem mass spectrometry. In this study, we evaluated the performance of amine-reactive isobaric Tandem Mass Tag (TMT), available as duplex and sixplex sets, with regard to their ability to elucidate protein expression changes. Using rat brain tissue from two different developmental time points, postnatal day 1 (p1) and 45 (p45), as a model system, we compared the protein expression ratios (p45/p1) observed using duplex TMT tags in triplicate measurements versus sixplex tag in a single LC-MS/MS analysis. A correlation of 0.79 in relative protein abundance was observed in the proteins quantified by these two sets of reagents. However, more proteins passed the criteria for significant fold change (-1.0 ? log2 ratio (p45/p1) ? +1.0 and p < 0.05) in the sixplex analysis. Nevertheless, in both methods most proteins showing significant fold change were identified by multiple spectra, increasing their quantification precision. Additionally, the fold change in p45 rats against p1, observed in TMT experiments, was corroborated by a metabolic labeling strategy where relative quantification of differentially expressed proteins was obtained using 15N-labeled p45 rats as an internal standard. PMID:23214967

  12. Personality, Study Methods and Academic Performance

    ERIC Educational Resources Information Center

    Entwistle, N. J.; Wilson, J. D.

    1970-01-01

    A questionnaire measuring four student personality types--stable introvert, unstable introvert, stable extrovert and unstable extrovert--along with the Eysenck Personality Inventory (Form A) were give to 72 graduate students at Aberdeen University and the results showed recognizable interaction between study methods, motivation and personality…

  13. Approximate solution methods for partially observable Markov and semi-Markov decision processes

    E-print Network

    Yu, Huizhen, Ph. D. Massachusetts Institute of Technology

    2006-01-01

    We consider approximation methods for discrete-time infinite-horizon partially observable Markov and semi-Markov decision processes (POMDP and POSMDP). One of the main contributions of this thesis is a lower cost approximation ...

  14. Method for Determining the Radius Vector for a Planet from Two Observations of Position

    ERIC Educational Resources Information Center

    Gainer, Michael Kizinski

    1977-01-01

    Presents a method for determining the approximate radius vector of a planet or asteroid from two closely separated observation positions, using mathematics suitable for lower division college students. (MLH)

  15. Design and implementation of the canadian kidney disease cohort study (CKDCS): A prospective observational study of incident hemodialysis patients

    Microsoft Academic Search

    Aminu K Bello; Ravi Thadhani; Brenda Hemmelgarn; Scott Klarenbach; John Gill; Christopher Chan; Deborah Zimmerman; Daniel Holmes; George Cembrowski; Dawn Opgenorth; Rafael Sibrian; Mohammad Karkhaneh; Sophanny Tiv; Natasha Wiebe; Marcello Tonelli

    2011-01-01

    Background  Many nephrology observational studies use renal registries, which have well known limitations. The Canadian Kidney Disease\\u000a Cohort Study (CKDCS) is a large prospective observational study of patients commencing hemodialysis in five Canadian centers.\\u000a This study focuses on delineating potentially reversible determinants of adverse outcomes that occur in patients receiving\\u000a dialysis for end-stage renal disease (ESRD).\\u000a \\u000a \\u000a \\u000a \\u000a Methods\\/Design  The CKDCS collects information on

  16. Mixing and administration times of bypassing agents: observations from the Dosing Observational Study in Hemophilia (DOSE)

    PubMed Central

    Maahs, Jennifer; Donkin, Jennifer; Recht, Michael; Cooper, David L

    2014-01-01

    DOSE (Dosing Observational Study in Hemophilia) was a prospective, observational diary study designed to evaluate the use of bypassing agents in patients prescribed recombinant activated factor VII (rFVIIa) as first-line treatment in the home setting. Patients with congenital hemophilia with inhibitors and caregivers participated, and as part of the study, the time spent preparing and administering product was recorded for bypassing agent (BPA) infusions. The aim of this manuscript is to present the results of the analysis of the time spent preparing and administering a single dose of either rFVIIa or plasma-derived activated prothrombin complex concentrate (pd-aPCC). Diaries were completed for 18 adult patients and 19 caregivers of 21 children with 176 BPA-treated bleeding episodes and 1,350 BPA infusions (1,270 rFVIIa, 80 pd-aPCC). The median preparation and administration times were 5.0 minutes and 5.0 minutes for rFVIIa and 29.0 minutes and 24.5 minutes for pd-aPCC, respectively. Preparation and administration times were significantly shorter with rFVIIa than pd-aPCC (P<0.0001). The significantly shorter combined preparation and administration time of rFVIIa, taking into consideration the faster-than-recommended aPCC infusion rates, suggests that rFVIIa permits a rapid and safe initiation of treatment once a bleeding episode is identified and a decision is made to treat at home. PMID:25187744

  17. [Methods of psychotherapy case studies: current perspectives].

    PubMed

    Kramer, Ueli

    2011-01-01

    There is a renewal of interest among psychotherapy researchers and psychotherapists towards psychotherapy case studies. This article presents two paradigms that have greatly influenced this increasing interest in psychotherapy case studies : the pragmatic case study and the theory-building case study paradigm. The origins, developments and key-concepts of both paradigms are presented, as well as their methodological and ethical specificities. Examples of case studies, along with models developed, are cited. The differential influence of the post-modern schools on both paradigms are presented, as well as their contribution to the field of methods of psychotherapy case studies discussed and assessed in terms of relevance for the researcher and the psychotherapist. PMID:21983911

  18. Foreshock structures observed by THEMIS: case and statistical studies

    NASA Astrophysics Data System (ADS)

    Urbar, Jaroslav; Jelinek, Karel; Nemecek, Zdenek; Safrankova, Jana; Prech, Lubomir

    The ion foreshock region is typically observed upstream of the Earth’s quasi-parallel bow shocks and is characterized by enhanced ULF waves. These waves are created due to the interaction of the solar wind plasma with the ions reflected at the bow shock. As a result, fast magnetosonic waves are generated with an in-phase relationship between ion flux and magnetic field fluctuations. Using multipoint observations upstream of Earth’s bow shock from the Themis mission, we present statistical maps of modification of upstream parameters due to foreshock processes (solar wind heating and deceleration, enhancements of the magnetic field fluctuation level, etc.). The statistical study is complemented with case studies of transient phenomena in the foreshock like foreshock bubbles, hot flow anomalies, and others. We investigate an influence of foreshock effects on the bow shock and magnetopause motions and discuss a role of energetic particles and magnetic field orientations in these processes.

  19. Formal Methods Case Studies for DO-333

    NASA Technical Reports Server (NTRS)

    Cofer, Darren; Miller, Steven P.

    2014-01-01

    RTCA DO-333, Formal Methods Supplement to DO-178C and DO-278A provides guidance for software developers wishing to use formal methods in the certification of airborne systems and air traffic management systems. The supplement identifies the modifications and additions to DO-178C and DO-278A objectives, activities, and software life cycle data that should be addressed when formal methods are used as part of the software development process. This report presents three case studies describing the use of different classes of formal methods to satisfy certification objectives for a common avionics example - a dual-channel Flight Guidance System. The three case studies illustrate the use of theorem proving, model checking, and abstract interpretation. The material presented is not intended to represent a complete certification effort. Rather, the purpose is to illustrate how formal methods can be used in a realistic avionics software development project, with a focus on the evidence produced that could be used to satisfy the verification objectives found in Section 6 of DO-178C.

  20. Geophysical methods in radon risk studies.

    PubMed

    Wysocka, Malgorzata; Kotyrba, Andrzej; Chalupnik, Stanislaw; Skowronek, Jan

    2005-01-01

    The results of the studies presented in the paper have shown that in the Upper Silesian Region in Poland, radon indoor concentration levels depend first of all on the geological structure of the subsurface layers. The essential factors influencing radon migration ability are the mining-induced transformations of a rock mass. In some cases, significant variations of radon potential have been found at sites featuring similar geological structures and experiencing comparable mining effects. To find out the causes of these variations, studies involving geophysical methods such as electrical resistivity profiling (PE) and electrical resisitivity sounding (VES) were used. These studies have shown that the measurements made using the electrical resistivity method can be helpful in evaluating radon potential of both the tectonically disturbed areas and the mining-transformed ones. PMID:15885380

  1. Gender differences in young children's temperament traits: comparisons across observational and parent-report methods.

    PubMed

    Olino, Thomas M; Durbin, C Emily; Klein, Daniel N; Hayden, Elizabeth P; Dyson, Margaret W

    2013-04-01

    Evidence supporting the continuity between child temperament and adult personality traits is accumulating. One important indicator of continuity is the presence of reliable gender differences in traits across the lifespan. A substantial literature demonstrates gender differences on certain adult personality traits and recent meta-analytic work on child samples suggests similar gender differences for some broad and narrow domains of temperament. However, most existing studies of children rely only on parent-report measures. The present study investigated gender differences in temperament traits assessed by laboratory observation, maternal-report, and paternal-report measures. Across three independent samples, behavioral observations, maternal-report, and paternal-report measures of temperament were collected on 463 boys and 402 girls. Across all three methods, girls demonstrated higher positive affect and fear and lower activity level than boys. For laboratory measures, girls demonstrated higher levels of sociability and lower levels of overall negative emotionality (NE), sadness, anger and impulsivity than boys. However, girls demonstrated higher levels of overall NE and sadness than boys when measured by maternal reports. Finally, girls demonstrated lower levels of sociability based on paternal reports. Results are discussed in relation to past meta-analytic work and developmental implications of the findings. PMID:22924826

  2. Examining Soil Moisture Variability and Field Mean Estimation Methods using Nested Observations

    NASA Astrophysics Data System (ADS)

    Peterson, A.; Helgason, W.; Ireson, A. M.

    2014-12-01

    Information about soil moisture is typically required at the field scale. Direct measurements of soil moisture at this scale are not possible, though there are a number of promising indirect methods (e.g. remote sensing methods and cosmic-ray neutrons). Methods for obtaining point scale measurements of soil moisture are well established. However, variability of soil moisture, in both space and time, makes accurately determining field scale soil moisture from point measurements difficult. Understanding sub-field scale variability is a key step in determining how to upscale point measurements, and in particular to identify the minimum number of point measurements necessary to represent field scale mean soil moisture. Objectives of this study are to: (1) examine the spatial variability of soil moisture with time, and (2) compare field scale soil moisture estimation methods. Nested soil moisture measurements provided observations covering a 5002m2 area within a semi-arid prairie pasture site in southern Saskatchewan, Canada. Complementary measurements of the water balance were measured using meteorological and flux instrumentation. Spatial variability of surface and root zone soil moisture were examined using data from gridded dielectric water content probe surveys and a neutron probe array. Field scale surface soil moisture was measured at the site using a cosmic-ray neutron probe. The field scale estimation methods compared are: (1) water balance, (2) upscaling by averaging point scale measurements, (3) upscaling by identification of average representative time stable sites, and (4) extrapolation of shallow soil moisture measured by cosmic-ray neutron probe. Variability of surface soil moisture was found to be smallest under extreme dry and wet conditions, and largest during intermediate moisture conditions. Large spatial variability was found in the root zone, with soil moisture being most temporally variable closer to the surface.

  3. Handover patterns: an observational study of critical care physicians

    PubMed Central

    2012-01-01

    Background Handover (or 'handoff') is the exchange of information between health professionals that accompanies the transfer of patient care. This process can result in adverse events. Handover 'best practices', with emphasis on standardization, have been widely promoted. However, these recommendations are based mostly on expert opinion and research on medical trainees. By examining handover communication of experienced physicians, we aim to inform future research, education and quality improvement. Thus, our objective is to describe handover communication patterns used by attending critical care physicians in an academic centre and to compare them with currently popular, standardized schemes for handover communication. Methods Prospective, observational study using video recording in an academic intensive care unit in Ontario, Canada. Forty individual patient handovers were randomly selected out of 10 end-of-week handover sessions of attending physicians. Two coders independently reviewed handover transcripts documenting elements of three communication schemes: SBAR (Situation, Background, Assessment, Recommendations); SOAP (Subjective, Objective, Assessment, Plan); and a standard medical admission note. Frequency and extent of questions asked by incoming physicians were measured as well. Analysis consisted of descriptive statistics. Results Mean (± standard deviation) duration of patient-specific handovers was 2 min 58 sec (± 57 sec). The majority of handovers' content consisted of recent and current patient status. The remainder included physicians' interpretations and advice. Questions posed by the incoming physicians accounted for 5.8% (± 3.9%) of the handovers' content. Elements of all three standardized communication schemes appeared repeatedly throughout the handover dialogs with no consistent pattern. For example, blocks of SOAP's Assessment appeared 5.2 (± 3.0) times in patient handovers; they followed Objective blocks in only 45.9% of the opportunities and preceded Plan in just 21.8%. Certain communication elements were occasionally absent. For example, SBAR's Recommendation and admission note information about the patient's Past Medical History were absent from 22 (55.0%) and 20 (50.0%), respectively, of patient handovers. Conclusions Clinical handover practice of faculty-level critical care physicians did not conform to any of the three predefined structuring schemes. Further research is needed to examine whether alternative approaches to handover communication can be identified and to identify features of high-quality handover communication. PMID:22233877

  4. Observational and theoretical studies of rich clusters with multiple subcondensations

    NASA Technical Reports Server (NTRS)

    Geller, M. J.; Huchra, J. P.

    1984-01-01

    Observational and theoretical studies of the formation and evolution of clusters of galaxies are investigated. The relationship between the properties of individual galaxies and their environment is examined. Perphaps the most remarkable physical result derived from these is the apparent substructure in redishift position space. The distribution of spiral galaxies is quite different from the distribution of the ellipticals. The velocity distribution for the spirals is also substantially broader than the distribution for the ellipticals.

  5. Fog forecasting: ``old fashioned'' semi-empirical methods from radio sounding observations versus ``modern'' numerical models

    NASA Astrophysics Data System (ADS)

    Holtslag, M. C.; Steeneveld, G. J.; Holtslag, A. A. M.

    2010-07-01

    Fog forecasting is a very challenging task due to the local and small-scale nature of the relevant physical processes and land surface heterogeneities. Despite the many research efforts, numerical models remain to have difficulties with fog forecasting, and forecast skill from direct model output is relatively poor. In order to put the progress of fog forecasting in the last decades into a historical perspective, we compare the fog forecasting skill of a semi-empirical method based on radio sounding observations (developed in the 60s and 70s) with the forecasting skill of a state-of-the-art numerical weather prediction model (MM5) for The Netherlands. The semi-empirical method under investigation, the Fog Stability Index, depends solely on the temperature difference between the surface and 850 hPa, the surface dew point depression and the wind speed at 850 hPa, and a threshold value to indicate the probability of fog in the coming hours. Using the critical success index (CSI) as a criterion for forecast quality, we find that the Fog Stability Index is a rather successful predictor for fog, with similar performance as MM5. The FSI could even been optimized for different observational stations in the Netherlands. Also, it appears that adding the 10 m wind as a predictor did not increase the CSI score for all stations. The results of the current study clearly indicate that the current state of knowledge requires improvement of the physical insight in different physical processes in order to beat simple semi-empirical methods.

  6. Continuing Studies in Support of Ultraviolet Observations of Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Clark, John

    1997-01-01

    This program was a one-year extension of an earlier Planetary Atmospheres program grant, covering the period 1 August 1996 through 30 September 1997. The grant was for supporting work to complement an active program observing planetary atmospheres with Earth-orbital telescopes, principally the Hubble Space Telescope (HST). The recent concentration of this work has been on HST observations of Jupiter's upper atmosphere and aurora, but it has also included observations of Io, serendipitous observations of asteroids, and observations of the velocity structure in the interplanetary medium. The observations of Jupiter have been at vacuum ultraviolet wavelengths, including imaging and spectroscopy of the auroral and airglow emissions. The most recent HST observations have been at the same time as in situ measurements made by the Galileo orbiter instruments, as reflected in the meeting presentations listed below. Concentrated efforts have been applied in this year to the following projects: The analysis of HST WFPC 2 images of Jupiter's aurora, including the Io footprint emissions. We have performed a comparative analysis of the lo footprint locations with two magnetic field models, studied the statistical properties of the apparent dawn auroral storms on Jupiter, and found various other repeated patterns in Jupiter's aurora. Analysis and modeling of airglow and auroral Ly alpha emission line profiles from Jupiter. This has included modeling the aurora] line profiles, including the energy degradation of precipitating charged particles and radiative transfer of the emerging emissions. Jupiter's auroral emission line profile is self-absorbed, since it is produced by an internal source, and the resulting emission with a deep central absorption from the overlying atmosphere permits modeling of the depth of the emissions, plus the motion of the emitting layer with respect to the overlying atmospheric column from the observed Doppler shift of the central absorption. By contrast the airglow emission line, which is dominated by resonant scattering of solar emission, has no central absorption, but displays rapid time variations and broad wings, indicative of a superthermal component (or corona) in Jupiter's upper atmosphere. Modeling of the observed motions of the plumes produced after the impacts of the fragments of Comet S/L-9 with Jupiter in July 1994, from the HST WFPC 2 imaging series.

  7. Development of a standard method to observe the surface friction of high-strength gels

    NASA Astrophysics Data System (ADS)

    Yamada, Kouhei; Watanabe, Yosuke; Yamada, Naoya; Wada, Masato; Gong, Jin; Makino, Masato; Kabir, M. Hasnat; Furukawa, Hidemitsu

    2014-03-01

    In 2003, the most effective but simple way was proposed to synthesize double network gels, whose compression fracture stress reached about 30MPa, while that of common gels were several tens kPa. Our group has focused on PAMPSPDMAAm DN gel, because it possibly has both biocompatibility and permeability, which are good for developing artificial articular cartilage and artificial blood vessel. It is also possibly used for rapid additive manufacturing with 3D gel printer. Here, we develop a novel apparatus of the ball on disk method to observe the surface friction of the DN gels. We hope to apply this apparatus for various studies about the tribological behavior of the gels, especially about the effect of external electric field on the gel friction.

  8. Asteroid orbital inversion using a virtual-observation Markov-chain Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Muinonen, Karri; Granvik, Mikael; Oszkiewicz, Dagmara; Pieniluoma, Tuomo; Pentikäinen, Hanna

    2012-12-01

    A novel virtual-observation Markov-chain Monte Carlo method (MCMC) is presented for the asteroid orbital inverse problem posed by small to moderate numbers of astrometric observations. In the method, the orbital-element proposal probability density is chosen to mimic the convolution of the a posteriori density by itself: first, random errors are simulated for each observation, resulting in a set of virtual observations; second, least-squares orbital elements are derived for the virtual observations using the Nelder-Mead downhill simplex method; third, repeating the procedure gives a difference between two sets of what can be called virtual least-squares elements; and, fourth, the difference obtained constitutes a symmetric proposal in a random-walk Metropolis-Hastings algorithm, avoiding the explicit computation of the proposal density. In practice, the proposals are based on a large number of pre-computed sets of orbital elements. Virtual-observation MCMC is thus based on the characterization of the phase-space volume of solutions before the actual MCMC sampling. Virtual-observation MCMC is compared to MCMC orbital ranging, a random-walk Metropolis-Hastings algorithm based on sampling with the help of Cartesian positions at two observation dates, in the case of the near-Earth asteroid (85640) 1998 OX4. In the present preliminary comparison, the methods yield similar results for a 9.1-day observational time interval extracted from the full current astrometry of the asteroid. In the future, both of the methods are to be applied to the astrometric observations of the Gaia mission.

  9. Preequating with Empirical Item Characteristic Curves: An Observed-Score Preequating Method

    ERIC Educational Resources Information Center

    Zu, Jiyun; Puhan, Gautam

    2014-01-01

    Preequating is in demand because it reduces score reporting time. In this article, we evaluated an observed-score preequating method: the empirical item characteristic curve (EICC) method, which makes preequating without item response theory (IRT) possible. EICC preequating results were compared with a criterion equating and with IRT true-score…

  10. Method of smoothing laser range observations by corrections of orbital parameters and station coordinates

    NASA Astrophysics Data System (ADS)

    Lala, P.; Thao, Bui Van

    1986-11-01

    The first step in the treatment of satellite laser ranging data is its smoothing and rejection of incorrect points. The proposed method uses the comparison of observations with ephemerides and iterative matching of corresponding parameters. The method of solution and a program for a minicomputer are described. Examples of results for satellite Starlette are given.

  11. Non-market economic valuation in developing countries: Role of participant observation method in CVM analysis

    Microsoft Academic Search

    Pradeep Chaudhry; Bilas Singh; Vindhya P. Tewari

    2007-01-01

    Developing countries have high proportion of black money and related corruption in the society in comparison to the developed ones. This aspect has to be kept in mind while conducting contingent valuation method (CVM) questionnaire survey (in-person) at the site whose economic valuation is being done. Participant observation method (POM) and unstructured interview schedule (UIS) are the two means, which

  12. Medical work Assessment in German hospitals: a Real-time Observation study (MAGRO) – the study protocol

    PubMed Central

    Mache, Stefanie; Groneberg, David A

    2009-01-01

    Background The increasing economic pressure characterizes the current situation in health care and the need to justify medical decisions and organizational processes due to limited financial resources is omnipresent. Physicians tend to interpret this development as a decimation of their own medical influence. This becomes even more obvious after a change in hospital ownership i.e. from a public to a private profit oriented organization. In this case each work procedure is revised. To date, most research studies have focused mainly on differences between hospitals of different ownership regarding financial outcomes and quality of care, leaving important organizational issues unexplored. Little attention has been devoted to the effects of hospital ownership on physicians' working routines. The aim of this observational real time study is to deliver exact data about physicians' work at hospitals of different ownership. Methods The consequences of different management types on the organizational structures of the physicians' work situation and on job satisfaction in the ward situation are monitored by objective real time studies and multi-level psycho diagnostic measurements. Discussion This study is unique in its focus. To date no results have been found for computer-based real time studies on work activity in the clinical field in order to objectively evaluate a physician's work-related stress. After a complete documentation of the physicians' work processes the daily work flow can be estimated and systematically optimized. This can stimulate an overall improvement of health care services in Germany. PMID:19505318

  13. The Museum Structured Group Experience: An Observational Study of Criterion Behaviors and Recommendations for Application.

    ERIC Educational Resources Information Center

    Chen, Jean

    In a 1973 Smithsonian behavioral science project, observational methods were used to record school group behaviors during docent guided tours in the National Museum of History and Technology. The purpose of this exploratory study was to reveal the natural museum habitat and criterion behaviors of visiting fourth through sixth graders. Children's…

  14. Studies on Training Ground Observers to Estimate Range to Aerial Targets.

    ERIC Educational Resources Information Center

    McCluskey, Michael R.; And Others

    Six pilot studies were conducted to determine the effects of training on range estimation performance for aerial targets, and to identify some of the relevant variables. Observers were trained to estimate ranges of 350, 400, 800, 1,500, or 2,500 meters. Several variations of range estimation training methods were used, including immediate…

  15. Success and Failure in Helping SMEs. A Three-Year Observational Study.

    ERIC Educational Resources Information Center

    Stewardson, Dave; Coleman, Shirley

    2003-01-01

    A 3-year observational study of a project to help small and medium-sized enterprises (SMEs) conducted by a British university highlighted initial contacts and working methods that were effective. Results identified why some SMEs do not make full use of facilities offered and reasons for overall success. (Contains 13 references.) (JOW)

  16. The Diagnostic and Therapeutic Impact of MRI: an Observational Multi-centre Study

    Microsoft Academic Search

    WILLIAM HOLLINGWORTH; CHRISTOPHER J. TODD; MATTHEW I. BELL; QAIS ARAFAT; SIMON GIRLING; KANTI R. KARIA; ADRIAN K. DIXON

    2000-01-01

    AIM: To provide information about the diagnostic and therapeutic impact of magnetic resonance imaging (MRI) and to compare the findings across diagnostic groups.MATERIALS AND METHODS: A prospective, observational study of 2017 consecutive referrals for MRI of the head, spine or knee at four imaging centres. Clinicians completed questionnaires before MRI stating initial diagnoses, diagnostic confidence and treatment plans. After imaging,

  17. Methods for studying metabolism in Drosophila.

    PubMed

    Tennessen, Jason M; Barry, William E; Cox, James; Thummel, Carl S

    2014-06-15

    Recent research using Drosophila melanogaster has seen a resurgence in studies of metabolism and physiology. This review focuses on major methods used to conduct this work. These include protocols for dietary interventions, measurements of triglycerides, cholesterol, glucose, trehalose, and glycogen, stains for lipid detection, and the use of gas chromatography-mass spectrometry (GC-MS) to detect major polar metabolites. It is our hope that this will provide a useful framework for both new and current researchers in the field. PMID:24631891

  18. Methods for studying metabolism in Drosophila

    PubMed Central

    Tennessen, Jason M.; Barry, William; Cox, James; Thummel, Carl S.

    2014-01-01

    Recent research using Drosophila melanogaster has seen a resurgence in studies of metabolism and physiology. This review focuses on major methods used to conduct this work. These include protocols for dietary interventions, measurements of triglycerides, cholesterol, glucose, trehalose, and glycogen, stains for lipid detection, and the use of gas chromatography/mass spectrometry (GC/MS) to detect major polar metabolites. It is our hope that this will provide a useful framework for both new and current researchers in the field. PMID:24631891

  19. Microbiota and healthy ageing: observational and nutritional intervention studies

    PubMed Central

    Brüssow, Harald

    2013-01-01

    Summary Hundred years ago Metchnikoff associated human health and particularly healthy ageing with a specific type of gut microbiota. Classical culture methods associated a decrease in bifidobacteria and an increase in enterobacteria with ageing. Modern molecular methods blurred this simple picture and documented a substantial inter-individual variability for the gut microbiome even when stratifying the elderly subjects according to health status. Nutritional interventions with resistant starch showed consistent gut microbiota changes across studies from different geographical areas and prebiotic supplementation induced a 10-fold increase in gut bifidobacteria. However, in the ELDERMET study, microbiota changes do not precede, but follow the changes in health status of elderly subjects possibly as a consequence of diet changes. PMID:23527905

  20. A generic method to constrain the dark matter model parameters from Fermi observations of dwarf spheroids

    SciTech Connect

    Tsai, Yue-Lin Sming [National Center for Nuclear Research, Hoza 69, 00-681 Warsaw (Poland); Yuan, Qiang [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, P.R.China (China); Huang, Xiaoyuan, E-mail: Sming.Tsai@fuw.edu.pl, E-mail: yuanq@ihep.ac.cn, E-mail: x_huang@bao.ac.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, P.R.China (China)

    2013-03-01

    Observation of ?-rays from dwarf galaxies is an effective way to search for particle dark matter. Using 4-year data of Fermi-LAT observations on a series of Milky Way satellites, we develop a general way to search for the signals from dark matter annihilation in such objects. Instead of giving prior information about the energy spectrum of dark matter annihilation, we bin the Fermi-LAT data into several energy bins and build a likelihood map in the ''energy bin - flux'' plane. The final likelihood of any spectrum can be easily derived through combining the likelihood of all the energy bins. It gives consistent result with that directly calculated using the Fermi Scientific Tool. This method is very efficient for the study of any specific dark matter models with ?-rays. We use the new likelihood map with Fermi-LAT 4 year data to fit the parameter space in three representative dark matter models: i) toy dark matter model, ii) effective dark matter operators, and iii) supersymmetric neutralino dark matter.

  1. An observational study of Algol-type binaries

    NASA Astrophysics Data System (ADS)

    Yerli, S. K.

    1999-12-01

    The primary purpose of this thesis is to obtain more accurate orbital parameters for a number of Algol-type binaries. In this study, five systems were observed in two observing runs in 1994 (La Palma, 7 nights) and 1997 (Mexico, 4 nights). The 1994 run consisted of single slit observations of U CrB, TU Mon and TX UMa. In 1997, U CrB was repeated and RS Vul and GU Her were added to the target list; in this case, the observing was carried out with an Echelle spectrograph. Data reduction was done using FIGARO and IRAF for the 1994 and 1997 data sets, respectively. The radial velocity curves of these five systems were analysed to obtain accurate orbital parameters, in particular to try to obtain radial velocity semi-amplitudes, K1 and K2, for both components. For U CrB, a new pair of K1 and K2 was found which leads us to a much more sensible point in the evolutionary sequence of this system. For TX UMa and TU Mon only confirmation of their published K1 values could be achieved because of their low resolution spectra which did not enable the other component to be resolved. For RS Vul, K1 was confirmed. Because of the inadequate phase coverage at one quadrature, the K2 value could not be improved, but a comparison was made with the latest published value. GU Her was defined to be a `cool algol' (i.e. both components are late type sub giants), and the K1 and K2 value of the system was found for the first time. Besides radial velocity studies, magnetic activity in Algol-type binaries and its relation to their evolutionary sequences is also discussed. In this part of study some Algol--type binaries are categorised into four Groups depending on the evolutionary stage of the system. We claim to find that there is a remarkable correlation between evolutionary status and X--ray activity in the mass losing star of the system. In addition to already observed and categorised systems a list of systems is presented as candidates for this categorisation.

  2. Globally Gridded Satellite (GridSat) Observations for Climate Studies

    NASA Technical Reports Server (NTRS)

    Knapp, Kenneth R.; Ansari, Steve; Bain, Caroline L.; Bourassa, Mark A.; Dickinson, Michael J.; Funk, Chris; Helms, Chip N.; Hennon, Christopher C.; Holmes, Christopher D.; Huffman, George J.; Kossin, James P.; Lee, Hai-Tien; Loew, Alexander; Magnusdottir, Gudrun

    2012-01-01

    Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them: there is no central archive of geostationary data for all international satellites, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multi-satellite climate studies. The International Satellite Cloud Climatology Project set the stage for overcoming these issues by archiving a subset of the full resolution geostationary data at approx.10 km resolution at 3 hourly intervals since 1983. Recent efforts at NOAA s National Climatic Data Center to provide convenient access to these data include remapping the data to a standard map projection, recalibrating the data to optimize temporal homogeneity, extending the record of observations back to 1980, and reformatting the data for broad public distribution. The Gridded Satellite (GridSat) dataset includes observations from the visible, infrared window, and infrared water vapor channels. Data are stored in the netCDF format using standards that permit a wide variety of tools and libraries to quickly and easily process the data. A novel data layering approach, together with appropriate satellite and file metadata, allows users to access GridSat data at varying levels of complexity based on their needs. The result is a climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation, and detection and tracking of the intertropical convergence zone.

  3. ADAPTIVE MATCHING IN RANDOMIZED TRIALS AND OBSERVATIONAL STUDIES

    PubMed Central

    van der Laan, Mark J.; Balzer, Laura B.; Petersen, Maya L.

    2014-01-01

    SUMMARY In many randomized and observational studies the allocation of treatment among a sample of n independent and identically distributed units is a function of the covariates of all sampled units. As a result, the treatment labels among the units are possibly dependent, complicating estimation and posing challenges for statistical inference. For example, cluster randomized trials frequently sample communities from some target population, construct matched pairs of communities from those included in the sample based on some metric of similarity in baseline community characteristics, and then randomly allocate a treatment and a control intervention within each matched pair. In this case, the observed data can neither be represented as the realization of n independent random variables, nor, contrary to current practice, as the realization of n/2 independent random variables (treating the matched pair as the independent sampling unit). In this paper we study estimation of the average causal effect of a treatment under experimental designs in which treatment allocation potentially depends on the pre-intervention covariates of all units included in the sample. We define efficient targeted minimum loss based estimators for this general design, present a theorem that establishes the desired asymptotic normality of these estimators and allows for asymptotically valid statistical inference, and discuss implementation of these estimators. We further investigate the relative asymptotic efficiency of this design compared with a design in which unit-specific treatment assignment depends only on the units’ covariates. Our findings have practical implications for the optimal design and analysis of pair matched cluster randomized trials, as well as for observational studies in which treatment decisions may depend on characteristics of the entire sample. PMID:25097298

  4. Combining geophysical methods for the observation of hydrological processes at the hillslope-scale

    NASA Astrophysics Data System (ADS)

    Martini, E.; Kögler, S.; Dierke, C.; Wollschlaeger, U.; Werban, U.; Behrens, T.; Schmidt, K.; Dietrich, P.; Zacharias, S.

    2012-12-01

    Knowledge of soil moisture dynamics beyond the point scale is of crucial importance e.g. for water management, hydrological studies, and for calibration and validation of soil water balance models. There is a clear need for robust and flexible monitoring technologies that are able to capture high resolution information over large areas. Fast, precise, and ideally in-situ, measurements may be obtained from geophysical surveys and distributed in-situ wireless soil moisture sensor networks. In the Harz Mountains (Central Germany), a 2.5 ha hillslope was chosen as study site, to be monitored using a wireless sensor network, consisting of Time-Domain Transmission (TDT) sensors, that are able to measure soil water content and, in addition, soil temperature. Along the hillslope, pedological features are correlated with topography, and lateral flows are expected to be a relevant component of the runoff process. The aim of the work is (i) to test and validate geophysical platforms at the small-catchment scale in terms of technological improvement and suitability for hydrological studies; (ii) to design spatially optimized monitoring strategies using geophysical methods; (iii) to validate soil moisture estimation using geophysical methods. For the preliminary study, a larger area of the catchment (144 ha in size) was investigated using three electromagnetical induction (EMI) sensors (EM38-DD, EM38-MK2 and EM31-MK2, Geonics Ltd., Canada) and a gamma-ray spectrometer (GF Instruments, Czech Republic).On the hillslope, time-lapse EMI data were collected, and measurements will be repeated in future surveys to monitor patterns in electrical conductivity of soil that are related to changes in the soil moisture content. Based on these data, a Latin Hypercube Sampling strategy (LHS) was applied to provide 30 sampling points for the soil moisture monitoring network. In order to intensify the observations at shorter distances, 10 additional points were added to the network. Before the installation, a careful sensor specific calibration was performed, measuring the voltage response in 7 fluids with different dielectric permittivities. Furthermore, an additional temperature calibration was done. In summary, within the study area, 40 network nodes have been installed, comprising 6 sensors each, installed at 3 different depths (two repetitions at 5, 25 and 50 cm). The data collected starting from August 2012 show the variability in the soil moisture patterns with high spatial and temporal resolution. They assist in the comparison and integration of different geophysical methods that are applied at the site to estimate hillslope-scale soil moisture dynamics.

  5. DNA Fingerprinting Validates Seed Dispersal Curves from Observational Studies in the Neotropical Legume Parkia

    PubMed Central

    Heymann, Eckhard W.; Lüttmann, Kathrin; Michalczyk, Inga M.; Saboya, Pedro Pablo Pinedo; Ziegenhagen, Birgit; Bialozyt, Ronald

    2012-01-01

    Background Determining the distances over which seeds are dispersed is a crucial component for examining spatial patterns of seed dispersal and their consequences for plant reproductive success and population structure. However, following the fate of individual seeds after removal from the source tree till deposition at a distant place is generally extremely difficult. Here we provide a comparison of observationally and genetically determined seed dispersal distances and dispersal curves in a Neotropical animal-plant system. Methodology/Principal Findings In a field study on the dispersal of seeds of three Parkia (Fabaceae) species by two Neotropical primate species, Saguinus fuscicollis and Saguinus mystax, in Peruvian Amazonia, we observationally determined dispersal distances. These dispersal distances were then validated through DNA fingerprinting, by matching DNA from the maternally derived seed coat to DNA from potential source trees. We found that dispersal distances are strongly right-skewed, and that distributions obtained through observational and genetic methods and fitted distributions do not differ significantly from each other. Conclusions/Significance Our study showed that seed dispersal distances can be reliably estimated through observational methods when a strict criterion for inclusion of seeds is observed. Furthermore, dispersal distances produced by the two primate species indicated that these primates fulfil one of the criteria for efficient seed dispersers. Finally, our study demonstrated that DNA extraction methods so far employed for temperate plant species can be successfully used for hard-seeded tropical plants. PMID:22514748

  6. An ensemble method for targeted adaptive observations applied to multiphase flows

    NASA Astrophysics Data System (ADS)

    Che, Zhizhao; Fang, Fangxin; Percival, James; Hewitt, Geoffrey; Pain, Christopher; Matar, Omar; Navon, Michael

    2013-11-01

    Many flow problems, such as turbulence and multiphase, are extremely complex due to their strong nonlinearity. It is important to simulate and measure different parameters accurately, such as pressure drops and flow rates, to which flow phenomena are very sensitive. Therefore, it is essential to put the sensors at the locations with larger impact, and to avoid locations with lower impact. Here, we proposed an ensemble method to estimate the impact of observations at different locations. Ensembles were generated by adding perturbations to the initial conditions, say. Different target functions were used to quantify the impact of observations. In comparing with other methods for estimating impact, this ensemble method is very simple to implement, and is independent of the definition of the target functions. This method is demonstrated by applying it to the one-dimensional Burgers equation. The next steps are to extend this method to various complex problems such as multiphase flows. Many flow problems, such as turbulence and multiphase, are extremely complex due to their strong nonlinearity. It is important to simulate and measure different parameters accurately, such as pressure drops and flow rates, to which flow phenomena are very sensitive. Therefore, it is essential to put the sensors at the locations with larger impact, and to avoid locations with lower impact. Here, we proposed an ensemble method to estimate the impact of observations at different locations. Ensembles were generated by adding perturbations to the initial conditions, say. Different target functions were used to quantify the impact of observations. In comparing with other methods for estimating impact, this ensemble method is very simple to implement, and is independent of the definition of the target functions. This method is demonstrated by applying it to the one-dimensional Burgers equation. The next steps are to extend this method to various complex problems such as multiphase flows. EPSRC Programme Grant EP/K003976/1.

  7. An observational study of salt fluxes in Delaware Bay

    NASA Astrophysics Data System (ADS)

    Aristizábal, María. F.; Chant, Robert J.

    2015-04-01

    An observational study was conducted in Delaware Bay during the summer of 2011 aiming to quantify the different mechanisms driving the salt flux in this system. Seven moorings, equipped with bottom-mounted ADCPs and CT sensors at difference depths, were deployed across a section of the estuary. The total area-averaged and tidal-averaged salt flux was decomposed in three different contributions: the advective salt flux that represents the flux caused by river input and meteorological-induced flows, the steady shear dispersion that is the salt flux driven by the estuarine exchange flow, and the tidal oscillatory salt flux that is induced by the tidal currents. The advective salt flux dominated over the steady shear dispersion and tidal oscillatory salt flux, because it was driven mainly by changes in sea surface height associated with wind-driven setup and setdown. The steady shear dispersion was always positive and presented a spring/neap variability that was consistent with a two-layer exchange flow. On the other hand, the tidal oscillatory salt flux fluctuated between positive and negative values, but increased around a strong neap tide and decreased on the following spring tide. This variability is contrary to previous parameterizations, whereby the tidal salt flux is proportional to the amplitude of the tidal currents. The observational estimate was compared to a parameterization that relates tidal salt flux as proportional to tidal current amplitude and stratification. The observational estimate agreed with this new parameterization when the river discharge was relatively constant.

  8. Spacelab Science Results Study. Volume 1; External Observations

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J. (Compiler)

    1999-01-01

    Some of the 36 Spacelab missions were more or less dedicated to specific scientific disciplines, while other carried a eclectic mixture of experiments ranging from astrophysics to life sciences. However, the experiments can be logically classified into two general categories; those that make use of the Shuttle as an observing platform for external phenomena (including those which use the Shuttle in an interactive mode) and those which use the Shuttle as a microgravity laboratory. This first volume of this Spacelab Science Results study will be devoted to experiments of the first category. The disciplines included are Astrophysics, Solar Physics, Space Plasma Physics, Atmospheric Sciences, and Earth Sciences. Because of the large number of microgravity investigations, Volume 2 will be devoted to Microgravity Sciences, which includes Fluid Physics, Combustion Science, Materials Science, and Biotechnology, and Volume 3 will be devoted to Space Life Sciences, which studies the response and adaptability of living organisms to the microgravity environment.

  9. Method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein

    DOEpatents

    Sinha, Dipen N. (Los Alamos, NM); Anthony, Brian W. (Clearfield, PA)

    1997-01-01

    A method for determining the octane rating of gasoline samples by observing corresponding acoustic resonances therein. A direct correlation between the octane rating of gasoline and the frequency of corresponding acoustic resonances therein has been experimentally observed. Therefore, the octane rating of a gasoline sample can be directly determined through speed of sound measurements instead of by the cumbersome process of quantifying the knocking quality of the gasoline. Various receptacle geometries and construction materials may be employed. Moreover, it is anticipated that the measurements can be performed on flowing samples in pipes, thereby rendering the present method useful in refineries and distilleries.

  10. GC/TOF-MS as a new method for halocarbon observation in the atmosphere

    NASA Astrophysics Data System (ADS)

    Obersteiner, Florian; Boenisch, Harald; Hoker, Jesica; Engel, Andreas

    2015-04-01

    The need for halocarbon measurements in the atmosphere arose with the anthropogenic emission of CFCs beginning in the 1950s and the discovery of their ozone depleting potential in the 1980s. CFCs were replaced by HCFCs and are nowadays replaced by HFCs, with new compounds continuously being developed and introduced to the atmosphere. While not being harmful to the ozone layer, HFCs are still greenhouse gases and many tend to be hazardous to human health at high concentration. They can also serve as tracers to study atmospheric transport at low concentration, making high precision measurement interesting to atmospheric studies. Gas chromatography coupled with time-of-flight mass spectrometry (GC/TOF-MS) is still a new method in the field of atmospheric halocarbon measurement compared to the well-established GC/QP(quadrupole)-MS. The QP-MS is indeed a very stable and easy-to-operate instrument but also limited by mass resolution and either mass range or sensitivity. We will present the general applicability of GC/TOF-MS to regular halocarbon observation by a time series of halocarbon measurements from the Taunus Observatory (Kleiner Feldberg, Germany) and the implementation of a second, high-resolution (max. R=4000) TOF-MS system. Both GC/TOF-MS systems are characterized with respect to reproducibility, non-linearity and limits of detection (LOD). Furthermore, the advantages of a higher mass resolution are demonstrated with respect to LOD, substance identification and substance quantification.

  11. [Economic assessment, a field between clinical research and observational studies].

    PubMed

    Launois, Robert

    2003-01-01

    Health technology assessments propose to study the differential impact of health interventions in a complex care system which is characterised by the multitude of individual behaviours and the diverse nature of the institutions involved. Current systems for data collection lend themselves poorly to this rigorous analysis of efficacy of treatments in the actual situations where they are used. Randomised trials endeavour to neutralise any parasitic interference which could compromise testing for a causal relationship between the treatment administered and the result obtained. Their methodology which establishes the term ceteris paribus in the principle of good practice lends itself poorly to an analysis of individual behaviour. Observational studies are start from actual treatment situations to describe them as reliably as possible. By definition, however, these assume that the natural course of events is not deviated by any intervention. The absence of an experimental plan increases the likelihood of bias and makes it more difficult to test for causal relationships. They lend themselves poorly to testing for incremental efficacy. The two instruments to be preferred are decisional analysis and quasi-experimental studies. Decisional analysis help to avoid the problems of external validity associated with randomised clinical trials by associating parameters which are extracted from data obtained from everyday practice. Quasi-experimental studies or pragmatic trials are based on the reality of behaviour of the prescriber and his/her patients; their impact on efficacy, quality of life social costs of the disease and of treatments may be identified under normal conditions of use. PMID:12609811

  12. Mucocutaneous manifestations of acquired hypoparathyroidism: An observational study.

    PubMed

    Sarkar, Somenath; Mondal, Modhuchanda; Das, Kapildev; Shrimal, Arpit

    2012-09-01

    Hypoparathyroidism is a disorder of calcium and phosphorus metabolism due to decreased secretion of parathyroid hormone. Hypoparathyroidism can be hereditary and acquired. Acquired hypoparathyroidism usually occurs following neck surgery (thyroid surgery or parathyroid surgery). Along with systemic manifestations, hypoparathyroidism produces some skin manifestations. Lack of study regarding mucocutaneous manifestations of acquired hypoparathyroidism prompted us to undertake this study. To evaluate the mucocutaneous manifestations of acquired hypoparathyroidism. An observational study done in a tertiary care hospital of Kolkata by comprehensive history taking, through clinical examination and relevant laboratory investigations. Twenty-one patients were included in the study. The commonest form of acquired hypoparathyroidism was neck surgery (thyroidectomy and parathyroidectomy operation). Mucocutaneous manifestations were present in 76.19% of patients. The most frequent mucocutaneous manifestation was found in the hairs like the loss of axillary hair (61.9%), loss of pubic hair (52.38%), coarsening of body hair (47.62%), and alopecia areata (9.52%). The nail changes noted were brittle and ridged nail, followed by onycholysis, onychosezia, and onychomedesis. The most common skin features were xerotic skin in 11 patients (52.38%), followed by pellagra-like skin pigmentation, pustular psoriasis and acne form eruption, bullous impetigo, etc. Mucosa was normal in all the cases excepting the one which showed oral candidiasis. PMID:23087872

  13. Comparison of snow mapping methods over the Weber River Basin, Utah using MODIS observations

    Microsoft Academic Search

    J. Han; V. V. Salomonson

    2008-01-01

    The MODIS instruments on the NASA Terra and Aqua spacecraft provide snow cover observations on a daily basis when cloud cover permits over the globe as well as for regional and local areas. This study reports progress on some work using Terra MODIS snow cover observations centered on the Weber River Basin. The Weber Basin covers 2500 square miles\\/6400 square

  14. Examination of Snow Mapping Methods Over the Weber River Basin, Utah Using MODIS Observations

    Microsoft Academic Search

    J. Han; V. V. Salomonson

    2007-01-01

    The MODIS instruments on the Terra and Aqua spacecraft provide snow cover observations on a daily basis when cloud cover permits over the globe as well as regional and local areas. This study reports some ongoing work using Terra MODIS snow cover observations centered on the Weber River Basin. The basin covers 2500 square miles\\/6400 square kilometers within the Great

  15. Observational methods to measure behaviors of captive cotton-top tamarins (Saguinus oedipus).

    PubMed

    Edwards, Lily N; Sorkin, Andrew E; Rhodes, Richard C; Petersson, Katherine H

    2010-01-01

    The purpose of this study was to identify efficient sampling methods for establishing accurate activity budgets for zoo animals. Seven cotton-top tamarins (Saguinus oedipus) from two zoos were videotaped for multiple 90 min sessions, 3 to 4 days per week for 12 weeks. An activity budget was constructed for each animal using a continuous sampling method to analyze 30 hr of video recording of each animal. These master datasets, reflecting actual behavior, were re-sampled using interval sampling lengths of 0.25, 0.5, 1, 2, 4, 5, 7, 10, 15 and 20 min, and cluster sampling protocols (periodic sessions of continuous sampling) of 10 min x 3, 15 min x 2, 20 min x 1, 15 min x 1 and 10 min x 1 (min x repetitions/90 min sample period) to construct additional activity budgets for each animal. The Canberra similarity index was used to determine the statistical relationship between these activity budgets and those based on the master datasets. As interval length increased, there was a consequent decrease in the accuracy of the associated activity budgets as compared with the master dataset. No cluster sampling protocols yielded activity budgets as accurate as the four shortest interval lengths, but all cluster sampling protocols were more accurate than the three longest interval lengths. All the tested protocols varied in ability to accurately portray animal behavior. Overall, interval sampling provided superior behavioral representations at lower observer input. Results from this study will potentially facilitate the standardization of behavior monitoring protocols at zoos. PMID:19653282

  16. A method for counting roots observed in minirhizotrons and their theoretical conversion to root length density

    Microsoft Academic Search

    S. T. Buckland; C. D. Campbell; L. A. Mackie-Dawson; G. W. Horgan; E. I. Duff

    1993-01-01

    A method for counting root intersections with observation tubes (mini- or micro-rhizotrons) is proposed that allows a theoretical\\u000a conversion of root counts to estimated root length density and which is robust to the effects of tracking along the tubes.\\u000a A field test showed that the method agreed well with measured root length densities in cores for wild cherry roots but

  17. Using direct clinical observation to assess the quality of cesarean delivery in Afghanistan: an exploratory study

    PubMed Central

    2014-01-01

    Background As part of a National Emergency Obstetric and Newborn Care (EmONC) Needs Assessment, a special study was undertaken in July 2010 to examine the quality of cesarean deliveries in Afghanistan and examine the utility of direct clinical observation as an assessment method in low-resource settings. Methods This cross-sectional assessment of the quality of cesareans at 14 facilities in Afghanistan included a survey of surgeons regarding their routine cesarean practices, direct observation of 29 cesarean deliveries and comparison of observations with facility records for 34 additional cesareans conducted during the 3 days prior to the observation period at each facility. For both observed cases and record reviews, we assessed time intervals between specified points of care-arrival to the ward, first evaluation, detection of a complication, decision for cesarean, incision, and birth. Results All time intervals with the exception of “decision to skin incision” were longer in the record reviews than in observed cases. Prior cesarean was the most common primary indication for all cases. All mothers in both groups observed survived through one hour postpartum. Among newborns there were two stillbirths (7%) in observed births and seven (21%) record reviews. Although our sample is too small to show statistical significance, the difference is noteworthy. In six of the reviewed cesareans resulting in stillbirth, a fetal heart rate was recorded in the operating theater, although four were recorded as macerated. For the two fresh stillbirths, the cesarean surgeries were recorded as scheduled and not urgent. Conclusions Direct observation of cesarean deliveries enabled us to assess a number of preoperative, postoperative, and intraoperative procedures that are often not described in medical records in low resource settings. Comparison of observations with findings from provider interviews and facility records allowed us to infer whether observed practices were typical of providers and facilities and detect potential Hawthorne effects. PMID:24886143

  18. 75 FR 17411 - Submission for OMB Review; Comment Request; Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

    ...Comment Request; Women's Health Initiative...Observational Study SUMMARY: Under...Collection: Title: Women's Health Initiative...Observational Study. Type of Information...Respondents: Women, next-of-kin...physician's office staff...Observational Study...

  19. 75 FR 3237 - Proposed Collection; Comment Request; Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-20

    ...Comment Request; Women's Health Initiative...Observational Study SUMMARY: In...Title: The Women's Health Initiative...Observational Study. Type of Information...Respondents: Women, next-of-kin...physician's office staff...Observational Study...

  20. GPS based method of ionospheric study

    NASA Astrophysics Data System (ADS)

    Gwal, A. K.; Sarkar, S.; Malhotra, K.

    The GPS ionospheric sounding is a powerful tool for remote sensing of the ionosphere. The GPS signals have provided an unique opportunity to study the short scale length variations in TEC (Total Electron Content) along the signal path in the presence of ionospheric irregularities and scintillations caused by these irregularities. GPS based ionospheric measurement can measure TEC variations smaller than 10-2 TEC unit. This paper presents the observations of real time TEC and scintillation obtained with dual frequency GPS receiver GSV4004A at Bhopal. The receiver is specially configured to measure amplitude and phase scintillation from the L1 frequency GPS signals and ionospheric TEC from the L1 (1575 MHz) and L2 (1227 MHz) frequency GPS signals. The data for TEC and scintillation have been analyzed and the results for the crest of anomaly region (Bhopal) have been discussed.

  1. Observational study of job satisfaction in hospital pharmacy technicians.

    PubMed

    Sanford, M E; Facchinetti, N J; Broadhead, R S

    1984-12-01

    Intrinsic and extrinsic factors contributing to job satisfaction of pharmacy technicians in two community hospitals were studied. A pharmacy student employed part-time as a pharmacy technician by one of the hospitals observed fellow technicians in a wide range of job activities for 22 months. In a second hospital, the same student conducted similar observations during one summer while posing as a social researcher. Both hospitals had technician training programs providing classroom instruction and on-the-job training. Data were gathered primarily from informal conversations with technicians and pharmacists and by recording activities through notetaking. Formal training programs, praise from pharmacists, opportunities to train other technicians, diversity of job activities, and autonomy in coordinating work with time demands were identified as factors contributing to job satisfaction of technicians. Negative aspects of the job that employers attempted to circumvent or clarify were the unchallenging nature of the work and the limited opportunities for advancement. Technicians' and pharmacists' attitudes toward job enrichment for technicians are discussed, and suggestions for improving technicians' intrinsic and extrinsic job satisfaction are provided. A reliable cadre of pharmacy technicians is necessary for further expansion of clinical pharmacy services under current hospital budgetary restraints. In addition to modifying job activities to promote technicians' intrinsic job satisfaction, pharmacy managers can improve extrinsic satisfaction by providing adequate salaries, job security, and flexible work schedules. PMID:6517083

  2. [Observational study of atmospheric HONO in summer of Beijing].

    PubMed

    Zhu, Yan-Wu; Liu, Wen-Qing; Xie, Pin-Hua; Dou, Ke; Liu, Shi-Sheng; Si, Fu-Qi; Li, Su-Wen; Qin, Min

    2009-06-15

    The concentration of HONO, NO2, O3 and other atmospheric pollutants were observed continuously by using differential optical absorption spectroscopy (DOAS) from 2007-08-14 to 2007-08-24 in Beijing, China. Diurnal variation characteristics of HONO and NO2 were analyzed. The HONO levels originated from the nocturnal direct emission were discussed. And the correlation between the heterogeneous formation of HONO and its related factors (BC, RH, and so on) was studied. The results showed that HONO had two peaks at about 01:00 and 06:00, respectively, while two peaks of NO2 concentrations appeared at about 01:00 and 07:00. The highest HONO(em)/HONO ratio of 31.3% was observed at about 20:00 between 19:00 to 07:00, and the average ratio was 15%. Good correlation of HONO(corr)/NO2 ratio with BC and RH at night was obtained. The correlation suggested that heterogeneous NO2 to HONO conversion processes may occur on BC surfaces by reaction with absorption water, and the average nighttime conversion frequency from NO2 into HONO (HONO/NO2) was calculated about 0.8% x h(-1). At the same time, the results showed that heterogeneous formation of HONO was increased with RH and inhibited at RH > 80%, and the hypothesis was further supported by detailed analysis of selected case. PMID:19662832

  3. Molecular Carbon in the Galaxy: Laboratory and Observational Studies

    NASA Technical Reports Server (NTRS)

    Saykally, Richard James

    2003-01-01

    In a collaboration with the Mats Larsson group from Stockholm, we carried out a new measurement of the rate of dissociative recombination of H(sup *, sub j), using a new pulsed supersonic beam source of rotationally cold H(sup *, sub j). This source was first designed and characterized in our lab by IR cavity ringdown spectroscopy, determining a rotationaYtranslationa1 temperature of 20-60K, depending on conditions. This new source was then taken to Stockholm for the recombination rate studies at the CRYRING storage ring. The recombination rate constant measured against temperature yields values consistent with the most recent calculations, whereas previous experimental measurements varied over a range of 10(exp 4) and were poor agreement with theory. This is a crucial achievement for understanding the ion chemistry of diffuse clouds. Moreover, this result in combination with recent observations implies a greatly enhanced (factor of 40) cosmic ray ionization rate in a diffuse cloud (zeta Persei) relative to previous studies. The implications of this are discussed in our recent Nature paper. An enhanced cosmic-ray flux towards zeta Persei inferred from a laboratory study of the H(sup *, sub j)-e(sup -) recombination rate.

  4. Pediatric fractures through the eyes of parents: an observational study.

    PubMed

    Sofu, Hakan; Gursu, Sarper; Kockara, Nizamettin; Issin, Ahmet; Oner, Ali; Camurcu, Yalkin

    2015-01-01

    The present study is an observational cross-sectional study. The main purpose of this research was to analyze the perception and behaviors of parents in a series of pediatric upper extremity fracture cases. Hundred and seventeen patients younger than 12 years who were conservatively treated for the upper extremity fracture were included in our study. Parents of the patients were requested to answer a family-centered questionnaire related to their child's fracture and its treatment. When the parents were asked whether they believe casting would be sufficient or not as the treatment of their child's fracture, 84.6% answered 'yes', 13.7% answered 'I am not sure,' and 1.7% answered 'no.' Sixty-four of the parents were not worried about any residual defect in joint or extremity functions related to fracture, whereas 21 were worried and 32 were not sure on this. The rate of searching further information about the child's fracture was 34.2% and the mostly used source was the Internet. Twenty-eight of the 117 respondents (23.9%) emphasized that they would reduce the time their child spend outside the home at least for a while after the removal of cast. When conservatively treating a child's fracture, physicians dealing with traumatology should always consider the parents' perception and behaviors as critically important. PMID:25590848

  5. Swarm Observations of Field-Aligned Currents: Case Studies

    NASA Astrophysics Data System (ADS)

    Le, G.; Chi, P. J.; Gjerloev, J. W.; Stolle, C.; Luhr, H.; Park, J.; Rauberg, J.

    2014-12-01

    In this paper, we report the results of a few case studies of multi-point magnetic field measurements of field-aligned currents (FACs) from Swarm constellation mission to understand their temporal and spatial characteristics. During the commissioning phase, the three Swarm spacecraft were in an identical polar orbit with a string-of-pearl configuration with small separations. During the science operational phase (since April, 2014), the three spacecraft were placed in slightly different polar orbits: one spacecraft in a higher altitude orbit (507km x 512km) and two side-by-side in lower altitude orbits (459km x 462km). We analyze a few FAC events in both orbital phases and during periods of active geomagnetic conditions. The multi-point observations enable us to examine the FACs' temporal evolution and separate their temporal and spatial variations.

  6. Observation of pain behavior in the NICU: an exploratory study.

    PubMed

    Bozzette, M

    1993-06-01

    Pain in children has been historically undertreated for a variety of reasons, including the complexity of pain assessment, inadequate research and training, and assumptions concerning pain. Lack of consistency in pain assessment and personal attitudes about pain have been identified as concerns in the NICU population. Some of the factors that are thought to affect caregivers include personal experience with pain and the idea that some procedures are more painful than others. Nurses currently have insufficient assessment tools and limited education about pain assessment in non-verbal infants. Personal beliefs also vary widely as to the nature and intensity of pain. The problem is further compounded by the abstract nature and the possible range of responses to painful stimuli. Behavior is the main source of information in nonverbal infants. However, depletion of an infant's response capacity can occur rapidly with stress, gestational age, and illness. In addition, behavioral responses may also be affected by multiple interventions, intubation, and paralytic drugs. Specific facial and motor behaviors were observed responses to pain in this sample of infants as well as increased heart rate and oxygen desaturation. No one single behavior constitutes an unequivocal measure of infant pain. However, characteristic patterns of distress have emerged from analysis of infant facial expressions, motor responses, and cries. Frequent and prolonged pain may be potentially harmful to the developing nervous system and may threaten the physiologic stability of premature and sick term infants. Whether or not a premature infant has the capacity to perceive pain is not in question, but these infants do have limited abilities to express their pain. Defining common behaviors that consistently appear with painful stimuli will assist in the identification of pain so that appropriate interventions to assess and to relieve pain can be planned. A variety of factors complicates the observation of neonates in an NICU. Premature birth, range of physiologic stability, the level of activity in the environment, and other possible sources of discomfort may confuse or blunt observations. While this observational design was difficult, it succeeded in delineating behaviors associated with a painful stimulus that provides a basis for further study. PMID:8336293

  7. Observational Studies of Pre-Main Sequence Stars

    NASA Astrophysics Data System (ADS)

    Hutchinson, M. G.

    1988-12-01

    This work investigates selected young stars paying particular attention to their photometric and polarimetric characteristics. The stars observed represent particular sub-classes of the Orion Population of young stars: T Tauri stars of about one solar mass (RY Lup, RU Lup, CoD -33o10685 and AK Sco); Herbig Ae/Be stars of a few solar masses (TY CrA, R CrA, T CrA and V856 Sco); a YY Ori star which is thought to be still accreting matter (S CrA); and an 'isolated' T Tauri star which lies away from a star-forming cloud (V4046 Sgr). Data was acquired at ultraviolet, optical and infrared wavelengths, along with optical polarimetric data. The subsequent analysis of data for the well-studied stars can be summarised as follows: the spectroscopic characteristics of the star are defined; possible mechanisms for the photometric variability are discussed; and given the spectral type of the star, the intrinsic flux distribution is determined and the parameters of the optical and infrared emission are thereby determined. The implications of any photometric variability found are also discussed. A possible model of polarisation is discussed and the wavelength dependence of polarisation in eleven young stars is analysed. It is found that the circumstellar environment plays a role in many of the observed characteristics of the stars studied. Several of the stellar spectra show lines which form in a stellar envelope. Each star is found to be affected by circumstellar extinction and to exhibit infrared emission from circumstellar dust. In most cases the circumstellar dust also gives rise to the optical polarisation. The photometric and/or polarimetric variability exhibited by some of the stars is ascribable to changes in the circumstellar dust shell opacity

  8. Estimating climatological planetary boundary layer heights from radiosonde observations: Comparison of methods and uncertainty analysis

    Microsoft Academic Search

    Dian J. Seidel; Chi O. Ao; Kun Li

    2010-01-01

    Planetary boundary layer (PBL) processes control energy, water, and pollutant exchanges between the surface and free atmosphere. However, there is no observation-based global PBL climatology for evaluation of climate, weather, and air quality models or for characterizing PBL variability on large space and time scales. As groundwork for such a climatology, we compute PBL height by seven methods, using temperature,

  9. A study and investigation of human error in time study observations

    E-print Network

    Case, Richard Blanch

    1954-01-01

    the ex~sent? . Hewevei?' due to the. ~- ed. length of 'time 'required for each oj~ativ'e' study: and the limited time eich observex' could devote to the study?. a diverse group of observers had to be used at different intex . vale? . 'fheso observirs...HUHAH EBB OR XH TX NE STUDY LI 8 ftARQ A k jH COLLEGE QF TEXAS A STUDY AItD I?VESTIGATIOS OIA ITUMAN ZBRQR T8 TIT& STUDY OBSERVATIONS Aprkoultural and. Nechauical College of Texas Iu'pargial fulfillment of the" reguiremeute for the Ce...

  10. CMB observations from the CBI and VSA: A comparison of coincident maps and parameter estimation methods

    E-print Network

    N. Rajguru; S. T. Myers; R. A. Battye; J. Richard Bond; K. Cleary; C. R. Contaldi; R. D. Davies; R. J. Davis; C. Dickinson; R. Genova-Santos; K. Grainge; Y. A. Hafez; M. P. Hobson; M. E. Jones; R. Kneissl; K. Lancaster; A. Lasenby; B. S. Mason; T. J. Pearson; G. G. Pooley; A. C. S. Readhead; R. Rebolo; G. Rocha; J. A. Rubino-Martin; R. D. E. Saunders; R. S. Savage; A. Scaife; P. F. Scott; J. L. Sievers; A. Slosar; A. C. Taylor; D. Titterington; E. Waldram; R. A. Watson; A. Wilkinson

    2005-11-04

    We present coincident observations of the Cosmic Microwave Background (CMB) from the Very Small Array (VSA) and Cosmic Background Imager (CBI) telescopes. The consistency of the full datasets is tested in the map plane and the Fourier plane, prior to the usual compression of CMB data into flat bandpowers. Of the three mosaics observed by each group, two are found to be in excellent agreement. In the third mosaic, there is a 2 sigma discrepancy between the correlation of the data and the level expected from Monte Carlo simulations. This is shown to be consistent with increased phase calibration errors on VSA data during summer observations. We also consider the parameter estimation method of each group. The key difference is the use of the variance window function in place of the bandpower window function, an approximation used by the VSA group. A re-evaluation of the VSA parameter estimates, using bandpower windows, shows that the two methods yield consistent results.

  11. 78 FR 24220 - Submission for OMB Review; 30-Day Comment Request: Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ...Comment Request: Women's Health Initiative Observational Study SUMMARY: Under the...Proposed Collection: Women's Health Initiative Observational Study. Revision--OMB...disease among older women by developing...

  12. 78 FR 32406 - Submission for OMB Review; 30-Day Comment Request: Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-30

    ...Comment Request: Women's Health Initiative Observational Study SUMMARY: Under the...Proposed Collection: Women's Health Initiative Observational Study. Revision- OMB No...disease among older women by developing...

  13. A new method for observing the running states of a single-variable nonlinear system.

    PubMed

    Meng, Yu; Chen, Hong; Chen, Cheng

    2015-03-01

    In order to timely grasp a single variable nonlinear system running states, a new method called Scatter Point method is put forward in this paper. It can be used to observe or monitor the running states of a single variable nonlinear system in real-time. In this paper, the definition of the method is given at first, and then its working principle is expounded theoretically, after this, some physical experiments based on Chua's nonlinear system are conducted. At the same time, many scatter point graphs are measured by a general analog oscilloscope. The motion, number, and distribution of these scatter points shown on the oscilloscope screen can directly reflect the current states of the tested system. The experimental results further confirm that the method is effective and practical, in which the system running states are not easily lost. In addition, this method is not only suitable for single variable systems but also for multivariable systems. PMID:25833428

  14. Methods to study chaperone-mediated autophagy.

    PubMed

    Patel, Bindi; Cuervo, Ana Maria

    2015-03-01

    Chaperone-mediated autophagy (CMA) is a multistep process that involves selective degradation and digestion of a pool of soluble cytosolic proteins in lysosomes. Cytosolic substrates are selectively identified and targeted by chaperones to lysosomes where they are subsequently translocated into the organelle lumen through a dedicated CMA-associated lysosomal membrane receptor/translocation complex. CMA contributes to maintaining a functional proteome, through elimination of altered proteins, and participates in the cellular energetic balance through amino acid recycling. Defective or dysfunctional CMA has been associated with human pathologies such as neurodegeneration, cancer, immunodeficiency or diabetes, increasing the overall interest in methods to monitor this selective autophagic pathway. Here, we describe approaches used to study CMA in different experimental models. PMID:25595300

  15. Automatic Method for Identifying Photospheric Bright Points and Granules Observed by Sunrise

    NASA Astrophysics Data System (ADS)

    Javaherian, M.; Safari, H.; Amiri, A.; Ziaei, S.

    2014-10-01

    In this study, we propose methods for the automatic detection of photospheric features (bright points and granules) from ultra-violet (UV) radiation, using a feature-based classifier. The methods use quiet-Sun observations at 214 nm and 525 nm images taken by Sunrise on 9 June 2009. The function of region growing and mean shift procedure are applied to segment the bright points (BPs) and granules, respectively. Zernike moments of each region are computed. The Zernike moments of BPs, granules, and other features are distinctive enough to be separated using a support vector machine (SVM) classifier. The size distribution of BPs can be fitted with a power-law slope -1.5. The peak value of granule sizes is found to be about 0.5 arcsec^2. The mean value of the filling factor of BPs is 0.01, and for granules it is 0.51. There is a critical scale for granules so that small granules with sizes smaller than 2.5 arcsec^2 cover a wide range of brightness, while the brightness of large granules approaches unity. The mean value of BP brightness fluctuations is estimated to be 1.2, while for granules it is 0.22. Mean values of the horizontal velocities of an individual BP and an individual BP within the network were found to be 1.6 km/s and 0.9 km/s, respectively. We conclude that the effect of individual BPs in releasing energy to the photosphere and maybe the upper layers is stronger than what the individual BPs release into the network.

  16. [Institutionalized elderly and depression: a multicenter observational study].

    PubMed

    Storti, Matteo; Braggion, Marco; Dal Santo, Pierluigi; Fanchin, Gianmaria; Zanolin, Maria Elisabetta

    2012-04-01

    Scientific literature recommends nurses to use the Geriatric Depression Scale (GDS) in the assessment of symptoms of depression among elderly with no cognitive deficits. The first purpose of this observational study was to determine the prevalence of depressive symptoms and the related antidepressant therapy in a sample of institutionalized elderly people administering the 30 questions GDS (GDS 30). The second aim was to estimate the time to complete the test. The survey is a cross-sectional multicenter study. 115 cognitively intact elderly residents in 5 retirement houses in the province of Vicenza (Italy) were administered the 30 items GDS by nursing staff: 80 females with a median age of 83 years (Inter Quartile Range RIQ: 80-85) and 35 males with a median age of 79 years (RIQ: 73-85). The prevalence of depression was 46% (95% Confidence Interval: 37-55%). The difference in depression between males and females was not significant (p=0.646). The median of the total answering time was equal to 306 seconds (RIQ: 257-315). The answering time of the GDS in people taking antidepressants is higher with respect to those who do not take them. The GDS 30 is an useful tool for nurses to identify in a fairly short amount of time institutionalised individuals with no cognitive deficit and risk of depression. PMID:22561994

  17. A Method to Simulate the Observed Surface Properties of Proton Irradiated Silicon Strip Sensors

    E-print Network

    Timo Peltola; Ashutosh Bhardwaj; Ranjeet Dalal; Robert Eber; Thomas Eichhorn; Kavita Lalwani; Alberto Messineo; Martin Printz; Kirti Ranjan

    2015-03-10

    During the scheduled high luminosity upgrade of LHC, the world's largest particle physics accelerator at CERN, the position sensitive silicon detectors installed in the vertex and tracking part of the CMS experiment will face more intense radiation environment than the present system was designed for. To upgrade the tracker to required performance level, extensive measurements and simulations studies have already been carried out. A defect model of Synopsys Sentaurus TCAD simulation package for the bulk properties of proton irradiated devices has been producing simulations closely matching with measurements of silicon strip detectors. However, the model does not provide expected behavior due to the fluence increased surface damage. The solution requires an approach that does not affect the accurate bulk properties produced by the proton model, but only adds to it the required radiation induced properties close to the surface. These include the observed position dependency of the strip detector's charge collection efficiency (CCE). In this paper a procedure to find a defect model that reproduces the correct CCE loss, along with other surface properties of a strip detector up to a fluence $1.5\\times10^{15}$ 1 MeV n$_{\\textrm{eq}}$ cm$^{-2}$, will be presented. When applied with CCE loss measurements at different fluences, this method may provide means for the parametrization of the accumulation of oxide charge at the SiO2/Si interface as a function of dose.

  18. Observations on mattress covers: results of a pilot study.

    PubMed

    Thomas, S

    1998-01-01

    Samples of covers from three commercially available mattresses were examined in the laboratory using test methods originally devised for testing surgical dressings. These revealed that although the covers shared many common features, there were differences in the conformability and tensile properties which may be of some clinical relevance. The study also confirmed that with some minor modifications, the experimental techniques used would be suitable for a future, more comprehensive review of mattress performance. In a separate investigation designed to examine the consequences of a failure of a mattress cover, the bioburden of a foam core removed from a damaged cover revealed the presence of very large numbers of microorganism, well in excess of 10(10) per gram of foam which could act as a recevoir of contamination and thus a source of cross infection. PMID:10531919

  19. Observational Study of Spinal Muscular Atrophy Type 2 and 3

    PubMed Central

    Kaufmann, Petra; McDermott, Michael P.; Darras, Basil T.; Finkel, Richard; Kang, Peter; Oskoui, Maryam; Constantinescu, Andrei; Sproule, Douglas Michael; Foley, A. Reghan; Yang, Michele; Tawil, Rabi; Chung, Wendy; Martens, Bill; Montes, Jacqueline; O'Hagen, Jessica; Dunaway, Sally; Flickinger, Jean M.; Quigley, Janet; Riley, Susan; Glanzman, Allan M.; Benton, Maryjane; Ryan, Patricia A.; Irvine, Carrie; Annis, Christine L.; Butler, Hailly; Caracciolo, Jayson; Montgomery, Megan; Marra, Jonathan; Koo, Benjamin; De Vivo, Darryl C.

    2013-01-01

    Objective To characterize the short-term course of spinal muscular atrophy (SMA) in a genetically and clinically well-defined cohort of patients with SMA. Design A comprehensive multicenter, longitudinal, observational study. Setting The Pediatric Neuromuscular Clinical Research Network for SMA, a consortium of clinical investigators at 3 clinical sites. Participants Sixty-five participants with SMA types 2 and 3, aged 20 months to 45 years, were prospectively evaluated. Intervention We collected demographic and medical history information and determined the SMN2 copy number. Main Outcome Measures Clinical outcomes included measures of motor function (Gross Motor Function Measure and expanded Hammersmith Functional Motor Scale), pulmonary function (forced vital capacity), and muscle strength (myometry). Participants were evaluated every 2 months for the initial 6 months and every 3 months for the subsequent 6 months. We evaluated change over 12 months for all clinical outcomes and examined potential correlates of change over time including age, sex, SMA type, ambulatory status, SMN2 copy number, medication use, and baseline function. Results There were no significant changes over 12 months in motor function, pulmonary function, and muscle strength measures. There was evidence of motor function gain in ambulatory patients, especially in those children younger than 5 years. Scoliosis surgery during the observation period led to a subsequent decline in motor function. Conclusions Our results confirm previous clinical reports suggesting that SMA types 2 and 3 represent chronic phenotypes that have relatively stable clinical courses. We did not detect any measurable clinical disease progression in SMA types 2 and 3 over 12 months, suggesting that clinical trials will have to be designed to measure improvement rather than stabilization of disease progression. PMID:21320981

  20. Validation of Satellite-Based Objective Overshooting Cloud-Top Detection Methods Using CloudSat Cloud Profiling Radar Observations

    NASA Technical Reports Server (NTRS)

    Bedka, Kristopher M.; Dworak, Richard; Brunner, Jason; Feltz, Wayne

    2012-01-01

    Two satellite infrared-based overshooting convective cloud-top (OT) detection methods have recently been described in the literature: 1) the 11-mm infrared window channel texture (IRW texture) method, which uses IRW channel brightness temperature (BT) spatial gradients and thresholds, and 2) the water vapor minus IRW BT difference (WV-IRW BTD). While both methods show good performance in published case study examples, it is important to quantitatively validate these methods relative to overshooting top events across the globe. Unfortunately, no overshooting top database currently exists that could be used in such study. This study examines National Aeronautics and Space Administration CloudSat Cloud Profiling Radar data to develop an OT detection validation database that is used to evaluate the IRW-texture and WV-IRW BTD OT detection methods. CloudSat data were manually examined over a 1.5-yr period to identify cases in which the cloud top penetrates above the tropopause height defined by a numerical weather prediction model and the surrounding cirrus anvil cloud top, producing 111 confirmed overshooting top events. When applied to Moderate Resolution Imaging Spectroradiometer (MODIS)-based Geostationary Operational Environmental Satellite-R Series (GOES-R) Advanced Baseline Imager proxy data, the IRW-texture (WV-IRW BTD) method offered a 76% (96%) probability of OT detection (POD) and 16% (81%) false-alarm ratio. Case study examples show that WV-IRW BTD.0 K identifies much of the deep convective cloud top, while the IRW-texture method focuses only on regions with a spatial scale near that of commonly observed OTs. The POD decreases by 20% when IRW-texture is applied to current geostationary imager data, highlighting the importance of imager spatial resolution for observing and detecting OT regions.

  1. Satellite Observation Systems for Polar Climate Change Studies

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.

    2012-01-01

    The key observational tools for detecting large scale changes of various parameters in the polar regions have been satellite sensors. The sensors include passive and active satellite systems in the visible, infrared and microwave frequencies. The monitoring started with Tiros and Nimbus research satellites series in the 1970s but during the period, not much data was stored digitally because of limitations and cost of the needed storage systems. Continuous global data came about starting with the launch of ocean color, passive microwave, and thermal infrared sensors on board Nimbus-7 and Synthetic Aperture Radar, Radar Altimeter and Scatterometer on board SeaSat satellite both launched in 1978. The Nimbus-7 lasted longer than expected and provided about 9 years of useful data while SeaSat quit working after 3 months but provided very useful data that became the baseline for follow-up systems with similar capabilities. Over the years, many new sensors were launched, some from Japan Aeronautics and Space Agency (JAXA), some from the European Space Agency (ESA) and more recently, from RuSSia, China, Korea, Canada and India. For polar studies, among the most useful sensors has been the passive microwave sensor which provides day/night and almost all weather observation of the surface. The sensor provide sea surface temperature, precipitation, wind, water vapor and sea ice concentration data that have been very useful in monitoring the climate of the region. More than 30 years of such data are now available, starting with the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7, the Special Scanning Microwave/Imager (SSM/I) on board a Defense Meteorological Satellite Program (DMSP) and the Advanced Microwave Scanning Radiometer on board the EOS/ Aqua satellite. The techniques that have been developed to derive geophysical parameters from data provided by these and other sensors and associated instrumental and algorithm errors and validation techniques will be discussed. An important issue is the organization and storage of hundreds of terabytes of data collected by even just a few of these satellite sensors. Advances in mass storage and computer technology have made it possible to overcome many of the collection and archival problems and the availability of comprehensive satellite data sets put together by NASA's Earth Observing System project will be discussed.

  2. An Observational Study on Infective Endocarditis: A Single Center Experience

    PubMed Central

    Hosseini, Seyed Mohammad Javad; Bakhshian, Ramezan; Moshkani Farahani, Maryam; Abdar Esfahani, Morteza; Bahrami, Amir; Sate, Ali

    2014-01-01

    Background: Cloning of microorganisms on heart endothelium can lead to infective endocarditis (IE). The prototypic lesion of infective endocarditis, the vegetation is a mass of platelets, fibrin, microcolonies of microorganisms, and scant inflammatory cells. Objectives: The aim of this study was to evaluate patients with IE and also focusing on echocardiographic data and comparison between TTE (transthoracic echocardiography) and TEE (transesophageal echocardiography) of native and prosthetic valve endocarditis and the final impact of IE (infective endocarditis) in these patients with endocarditis. Patients and Methods: All patients with IE admitted to our center between 2007 and 2010 were studied. All echocardiographies were performed by the same echocardiographer. Echocardiography and lab tests were performed for all patients. We used SPSS 16 for data analysis. Results: We studied 35 patients, 45% male and 55% female with a mean age of 56.36 ± 12.44 years. Fever (80%) and chills (65.7%) were the most common symptoms. There was only a positive blood culture and enterococci sensitive to vancomycin and amoxicillin. The most involved valve was mitral (54.2%) and then aortic valve (48.5%) (two patients had vegetation on both aortic and mitral valves). In this study, specificity and sensitivity of TEE were 100% and 88.6%. Six patients (17.1%) died and six patients needed surgery. Conclusions: Endocarditis is an important disease with a high mortality rate if not treated appropriately. Therefore, these patients need more attention. In echocardiography, vegetation and complications of IE such as abscess and paravalvular leakage can be detected. PMID:25785248

  3. Comparison of Observation Impacts in Two Forecast Systems using Adjoint Methods

    NASA Technical Reports Server (NTRS)

    Gelaro, Ronald; Langland, Rolf; Todling, Ricardo

    2009-01-01

    An experiment is being conducted to compare directly the impact of all assimilated observations on short-range forecast errors in different operational forecast systems. We use the adjoint-based method developed by Langland and Baker (2004), which allows these impacts to be efficiently calculated. This presentation describes preliminary results for a "baseline" set of observations, including both satellite radiances and conventional observations, used by the Navy/NOGAPS and NASA/GEOS-5 forecast systems for the month of January 2007. In each system, about 65% of the total reduction in 24-h forecast error is provided by satellite observations, although the impact of rawinsonde, aircraft, land, and ship-based observations remains significant. Only a small majority (50- 55%) of all observations assimilated improves the forecast, while the rest degrade it. It is found that most of the total forecast error reduction comes from observations with moderate-size innovations providing small to moderate impacts, not from outliers with very large positive or negative innovations. In a global context, the relative impacts of the major observation types are fairly similar in each system, although regional differences in observation impact can be significant. Of particular interest is the fact that while satellite radiances have a large positive impact overall, they degrade the forecast in certain locations common to both systems, especially over land and ice surfaces. Ongoing comparisons of this type, with results expected from other operational centers, should lead to more robust conclusions about the impacts of the various components of the observing system as well as about the strengths and weaknesses of the methodologies used to assimilate them.

  4. In situ observation of crystal growth and concentration variation by spatial filtering method

    NASA Astrophysics Data System (ADS)

    Chen, Ya; Hao, Qun; Zhu, Qiudong

    2005-02-01

    A spatial filtering method was developed for in-situ observing crystal growth and concentration variation. We insert a polarizing filter between the growth chamber and objective lens for eliminating the transmitted light through the solution. The dark background introduced by polarizing filtering method is advantaged for observing the sample. Due to the birefringence property, the image of crystal is contributed by extraordinary-ray and ordinary-ray through the crystal and analyzer. Meanwhile, a high pass binary amplitude filter is inserted on the back focal plane of the objective lens for attenuating low-frequency information and transfer phase information of the object to intensity information of the image. The image intensity has become squarely related to the phase shift ? of the crystal and solution. It is possible to observe the phase object and also to inverse the image contrast and strengthen the image edge. The method has been successfully used to observe not only crystal morphology and details but also concentration field variation around the growing crystal.

  5. Creation of an ensemble of simulated cardiac cases and a human observer study: tools for the development of numerical observers for SPECT myocardial perfusion imaging

    NASA Astrophysics Data System (ADS)

    O'Connor, J. Michael; Pretorius, P. Hendrik; Gifford, Howard C.; Licho, Robert; Joffe, Samuel; McGuiness, Matthew; Mehurg, Shannon; Zacharias, Michael; Brankov, Jovan G.

    2012-02-01

    Our previous Single Photon Emission Computed Tomography (SPECT) myocardial perfusion imaging (MPI) research explored the utility of numerical observers. We recently created two hundred and eighty simulated SPECT cardiac cases using Dynamic MCAT (DMCAT) and SIMIND Monte Carlo tools. All simulated cases were then processed with two reconstruction methods: iterative ordered subset expectation maximization (OSEM) and filtered back-projection (FBP). Observer study sets were assembled for both OSEM and FBP methods. Five physicians performed an observer study on one hundred and seventy-nine images from the simulated cases. The observer task was to indicate detection of any myocardial perfusion defect using the American Society of Nuclear Cardiology (ASNC) 17-segment cardiac model and the ASNC five-scale rating guidelines. Human observer Receiver Operating Characteristic (ROC) studies established the guidelines for the subsequent evaluation of numerical model observer (NO) performance. Several NOs were formulated and their performance was compared with the human observer performance. One type of NO was based on evaluation of a cardiac polar map that had been pre-processed using a gradient-magnitude watershed segmentation algorithm. The second type of NO was also based on analysis of a cardiac polar map but with use of a priori calculated average image derived from an ensemble of normal cases.

  6. Validation of SCS CN Method for Runoff Estimation with Field Observed Regression Analysis Results in Venna Basin, Central India.

    NASA Astrophysics Data System (ADS)

    Katpatal, Y. B.; Paranjpe, S. V.; Kadu, M.

    2014-12-01

    Effective Watershed management requires authentic data of surface runoff potential for which several methods and models are in use. Generally, non availability of field data calls for techniques based on remote observations. Soil Conservation Services Curve Number (SCS CN) method is an important method which utilizes information generated from remote sensing for estimation of runoff. Several attempts have been made to validate the runoff values generated from SCS CN method by comparing the results obtained from other methods. In the present study, runoff estimation through SCS CN method has been performed using IRS LISS IV data for the Venna Basin situated in the Central India. The field data was available for Venna Basin. The Land use/land cover and soil layers have been generated for the entire watershed using the satellite data and Geographic Information System (GIS). The Venna basin have been divided into intercepted catchment and free catchment. Run off values have been estimated using field data through regression analysis. The runoff values estimated using SCS CN method have been compared with yield values generated using data collected from the tank gauge stations and data from the discharge stations. The correlation helps in validation of the results obtained from the SCS CN method and its applicability in Indian conditions. Key Words: SCS CN Method, Regression Analysis, Land Use / Land cover, Runoff, Remote Sensing, GIS.

  7. Fracture Risk Among Breast Cancer Survivors Results From the Women's Health Initiative Observational Study

    Microsoft Academic Search

    Zhao Chen; Michael Maricic; Tamsen L. Bassford; Mary Pettinger; Cheryl Ritenbaugh; Ana Maria Lopez; David H. Barad; Margery Gass; Meryl S. LeBoff

    2005-01-01

    Background:Breast cancer and its treatment may com- promise bone health. We tested the hypothesis in the Women'sHealthInitiativeObservationalStudythatpost- menopausal survivors of breast cancer have a higher risk for fractures compared with women who have no can- cer history. Methods: A prospective cohort (5.1 years' follow-up) study design was used. Breast cancer survivors were womenwhoreportedahistoryofbreastcancer(n=5298). A reference group included women who had

  8. An Observational Study on Outgrowing Food Allergy during Non-Birch Pollen-Specific, Subcutaneous Immunotherapy

    Microsoft Academic Search

    R. Alonso; E. Enrique; F. Pineda; M. Basagaña; M. M. San Miguel-Moncín; J. Bartra; R. Palacios; A. Cisteró-Bahíma

    2007-01-01

    Background: Birch pollen-specific immunotherapy (SIT) decreases allergy to foods containing birch pollen-homologous allergens. Cross-reactivity was also observed between plane tree pollen and some vegetable foods. Objective: The aim of this study was to evaluate the outgrowing of food allergy by patients suffering from vegetable food allergy associated with plane tree pollinosis (rhinoconjunctivitis and\\/or asthma) during plane tree pollen SIT. Methods:

  9. An observational study of Yasmin® in the management of women with polycystic ovary syndrome

    Microsoft Academic Search

    Manisha Palep-Singh; Karen Mook; Julian Barth; Adam Balen

    2004-01-01

    BackgroundPolycystic ovary syndrome (PCOS) is the commonest endocrine disturbance affecting women in the reproductive age group and encompasses signs of hyperandrogenism, menstrual cycle disturbances and obesity. Some of the symptoms of PCOS may be ameliorated by the combined oral contraceptive pill (COCP).MethodsA pilot observational study was carried out in a university teaching hospital setting to determine whether the clinical and

  10. Performance evaluation of the channelized Hotelling observer using bootstrap list-mode PET studies

    Microsoft Academic Search

    Corinne J. Groiselle; Y. D'Asseler; H. C. Gifford; S. J. Glick

    2003-01-01

    This study investigated whether list-mode PET data generated using the bootstrap method can be used to predict lesion detectability as assessed by the channelized Hotelling observer (CHO). A Monte-Carlo simulator was used to generate 2D PET list-mode data set acquisitions of a disk object. One of these list-mode sets was then used to create an ensemble of bootstrap list-mode sets.

  11. Methods for environmental change; an exploratory study

    PubMed Central

    2012-01-01

    Background While the interest of health promotion researchers in change methods directed at the target population has a long tradition, interest in change methods directed at the environment is still developing. In this survey, the focus is on methods for environmental change; especially about how these are composed of methods for individual change (‘Bundling’) and how within one environmental level, organizations, methods differ when directed at the management (‘At’) or applied by the management (‘From’). Methods The first part of this online survey dealt with examining the ‘bundling’ of individual level methods to methods at the environmental level. The question asked was to what extent the use of an environmental level method would involve the use of certain individual level methods. In the second part of the survey the question was whether there are differences between applying methods directed ‘at’ an organization (for instance, by a health promoter) versus ‘from’ within an organization itself. All of the 20 respondents are experts in the field of health promotion. Results Methods at the individual level are frequently bundled together as part of a method at a higher ecological level. A number of individual level methods are popular as part of most of the environmental level methods, while others are not chosen very often. Interventions directed at environmental agents often have a strong focus on the motivational part of behavior change. There are different approaches targeting a level or being targeted from a level. The health promoter will use combinations of motivation and facilitation. The manager will use individual level change methods focusing on self-efficacy and skills. Respondents think that any method may be used under the right circumstances, although few endorsed coercive methods. Conclusions Taxonomies of theoretical change methods for environmental change should include combinations of individual level methods that may be bundled and separate suggestions for methods targeting a level or being targeted from a level. Future research needs to cover more methods to rate and to be rated. Qualitative data may explain some of the surprising outcomes, such as the lack of large differences and the avoidance of coercion. Taxonomies should include the theoretical parameters that limit the effectiveness of the method. PMID:23190712

  12. Seismograms of explosions at Regional Distances in the Western U. S. : observations and reflectivity method modeling

    SciTech Connect

    Olsen, K.H.; Braile, L.W.

    1980-01-01

    Seismic energy propagating through vertically and laterally varying structures of the earth's crust and lower lithosphere-uppermost mantle is responsible for the numerous and complex seismic phases observed on short-period seismograms at regional distance ranges (100 to 2000 km). Recent advances in techniques for computing synthetic seismograms make it practical to calculate complete seismograms that realistically model many features of regional phases. A modified reflectivity method program is used to interpret some details of record sections of Nevada Test Site (NTS) underground explosions that were observed 700 to 800 km from the sources.

  13. Active Commuting to Elementary School and Adiposity: An Observational Study

    PubMed Central

    Liu, Yan

    2014-01-01

    Abstract Background: Active commuting to school (ACS; walking or cycling to school) appears promising for decreasing children's obesity risk, although long-term studies are sparse. The aim was to examine whether kindergarten ACS was associated with fifth-grade adiposity. Methods: This study was a secondary analysis of the Early Childhood Longitudinal Study, Kindergarten (n=7938). Enrollment in kindergarten (1998–1999) was nationally representative of the United States and follow-up occurred in 2004. Kindergarten ACS was the main exposure variable and fifth-grade BMI z-score was the main outcome measure. Covariates included (1) neighborhood safety and BMI z-score in kindergarten and (2) demographics (i.e., age, gender, race/ethnicity, socioeconomic status, single- vs. two-parent households, region of country, and urbanicity in fifth grade). Three interactions were included: school travel*neighborhood safety; school travel*BMI z-score (kindergarten); and school travel*socioeconomic status. Analysis of covariance accounted for the complex sampling design. Results: Kindergarten ACS was associated with lower BMI z-score in fifth grade. The interaction of school travel*neighborhood safety indicated that children from less-safe neighborhoods who did ACS in kindergarten had a lower fifth-grade BMI z-score (p<0.05) than their peers who did not do ACS in kindergarten (i.e., in terms of BMI, this difference was ?0.49?kg/m2 for children of average height in less-safe neighborhoods). Conclusion: Among children from less-safe neighborhoods, kindergarten ACS independently predicted lower BMI z-score in fifth grade among a national US cohort. Interventions and policies to increase ACS among young children, especially from unsafe neighborhoods, are warranted and should address parents' safety concerns. PMID:24443901

  14. Observational and numerical studies of extreme frontal scale contraction

    NASA Technical Reports Server (NTRS)

    Koch, Steven E.

    1995-01-01

    The general objective of this effort is to increase understanding of how frontal scale contraction processes may create and sustain intense mesoscale precipitation along intensifying cold fronts. The five-part project (an expansion of the originally proposed two-part project) employed conventional meteorological data, special mesoscale data, remote sensing measurements, and various numerical models. First an idealized hydrostatic modeling study of the scale contraction effects of differential cloud cover on low-level frontal structure and dynamics was completed and published in a peer-reviewed journal. The second objective was to complete and publish the results from a three dimensional numerical model simulation of a cold front in which differential sensible heating related to cloud coverage patterns was apparently crucial in the formation of a severe frontal squall line. The third objective was to use a nonhydrostatic model to examine the nonlinear interactions between the transverse circulation arising from inhomogeneous cloud cover, the adiabatic frontal circulation related to semi-geostrophic forcing, and diabatic effects related to precipitation processes, in the development of a density current-like microstructure at the leading edge of cold fronts. Although the development of a frontal model that could be used to initialize such a primitive equation model was begun, we decided to focus our efforts instead on a project that could be successfully completed in this short time, due to the lack of prospects for continued NASA funding beyond this first year (our proposal was not accepted for future funding). Thus, a fourth task was added, which was to use the nonhydrostatic model to test tentative hypotheses developed from the most detailed observations ever obtained on a density current (primarily sodar and wind profiler data). These simulations were successfully completed, the findings were reported at a scientific conference, and the results have recently been submitted to a peer-reviewed journal. The fifth objective was to complete the analysis of data collected during the Cooperative Oklahoma Profiler Studies (COPS-91) field project, which was supported by NASA. The analysis of the mesoscale surface and sounding data, Doppler radar imagery, and other remote sensing data from multi frequency wind profiler, microwave radiometer, and the Radio Acoustic Sounding System has been completed. This study is a unique investigation of processes that caused the contraction of a cold front to a microscale zone exhibiting an undular bore-like structure. Results were reported at a scientific conference and are being prepared for publication. In summary, considerable progress has been achieved under NASA funding in furthering our understanding of frontal scale contraction and density current - gravity wave interaction processes, and in utilizing models and remotely sensed data in such studies.

  15. Temperament in young adulthood and later mortality: prospective observational study

    PubMed Central

    McCarron, P; Gunnell, D; Harrison, G; Okasha, M; Davey, S

    2003-01-01

    Study objective: To determine the association between a clinician assessment of temperament in early adulthood and cause specific mortality. Design: Prospective observational study. Setting: Glasgow University. Participants: 9239 male former students aged 16–30 (mean 20.5) years who participated in an ongoing health survey from 1948–68. A physician recorded free text assessment of temperament, which seemed to capture aspects of personality (trait) and mental health (state), was coded into: stable, anxious, schizoid, hypomanic, odd, depressed, immature, hypochondriacal, unstable, and obsessive. Associations between temperament and mortality were investigated using Cox proportional hazards models. Main results: There were 878 deaths. Most students—8342 (90.3%)—were assessed as stable, the remaining 897 (9.7%) having at least one, and 103 (1.1%) having more than one, temperament type. The second most common temperament was anxiety, recorded in 520 (5.6%) students. In multivariable analyses, having at least one temperament type was associated with increased all cause and stroke mortality, hazard ratios (95% confidence intervals): 1.23 (1.01 to 1.50) and 1.95 (1.06 to 3.59) respectively, compared with stable students. Students with more than one temperament type had higher risk of death from: all causes, 2.05 (1.36 to 3.09); stroke, 3.26 (1.01 to 10.56); and cancer, 2.90 (1.62 to 5.20). Anxiety was positively associated with all cause and cancer mortality, respective hazard ratios: 1.36 (1.07 to 1.72) and 1.51 (1.04 to 2.20). Men labelled hypomanic had increased cardiovascular mortality risk, 1.90 (1.05 to 3.44). Conclusions: Markers of early adult psychological distress are associated with increased mortality. Mechanisms underlying these associations require investigation. PMID:14600116

  16. Prevalence of postpartum infections: a population-based observational study.

    PubMed

    Axelsson, Daniel; Blomberg, Marie

    2014-10-01

    We investigated the prevalence of postpartum infections among women giving birth during 1 year in a population-based observational/questionnaire study at seven hospitals in the southeast region of Sweden. Of the women >99% (n = 11,124) received a questionnaire to inquire if they had endometritis, mastitis, or wound, urinary tract or any other infection within 2 months postpartum and whether they received antibiotics for this. Prevalence rates for infections and antibiotic treatment were estimated. The response rate was 60.1%. At least one infectious episode was reported by 10.3% of the women and 7.5% had received antibiotics. The prevalence for infections with and without antibiotics were, respectively, mastitis 4.7% and 2.9%, urinary tract infection 3.0% and 2.4%, endometritis 2.0% and 1.7%, wound infection 1.8% and 1.2%. There was no inter-county difference in infection prevalence. Clinical postpartum infections in a high-resource setting are relatively common. PMID:25132521

  17. Paternal Age, Paternal Presence and Children's Health: An Observational Study.

    PubMed

    Gardiner, Julian; Sutcliffe, Alastair G; Melhuish, Edward; Barnes, Jacqueline

    2015-02-24

    In an observational study of 31,257 children we investigated the effects of paternal age at the time of the child's birth, paternal absence and non-biological fathers on children's health. Results are per 5 year change in paternal age. Older fathers were associated with lower rates of unintentional injuries, odds ratio (OR)=0.966, P=0.0027. There was a quadratic association between paternal age and risk of hospital admission, ?=0.0121, P=0.0109, with minimum risk at paternal age 37.7. Absent fathers were associated with increased risk of hospital admission, OR=1.19, P<10(-3), lower rates of complete immunizations to 9 months, OR=0.562, P<10(-3), higher Strength and Difficulties Questionnaire (SDQ) difficulties scores: ?=0.304, P=0.0024 (3 year olds), ?=0.697, P<10(-3) (5 year olds). Non-biological fathers were associated with increased risk of unintentional injury, OR=1.16, P=0.0319 and hospital admission, OR=1.26, P=0.0166; lower rates of complete immunizations to 9 months, OR=0.343, P=0.0309 and higher SDQ difficulties scores: ?=0.908, P<10(-3). PMID:25918623

  18. Trigeminocardiac reflex in neurosurgical practice: An observational prospective study

    PubMed Central

    Etezadi, Farhad; Orandi, Amir Ali; Orandi, Amir Hosein; Najafi, Atabak; Amirjamshidi, Abbas; Pourfakhr, Pejman; Khajavi, Mohammad Reza; Abbassioun, Kazem

    2013-01-01

    Background: Considering wide variations regarding the incidence of trigeminocardiac reflex (TCR) during cranial neurosurgical procedures, and paucity of reliable data, we intended to design a prospective study to determine the incidence of TCR in patients undergoing standard general anesthesia for surgery of supra/infra-tentorial cranial and skull base lesions. Methods: A total of 190 consecutive patients candidate for elective surgery of supra-tentorial, infra-tentorial, and skull base lesions were enrolled. All the patients were operated in the neurosurgical operating room of a university-affiliated teaching hospital. All surgeries were performed using sufficient depth of anesthesia achieved by titration of propofol–alfentanil mixture, adjusted according to target Cerebral State Index (CSI) values (40-60). All episodes of bradycardia and hypotension indicating the occurrence of TCR during the surgery (sudden decrease of more than 20% from the previous level) were recorded. Results: Four patients, two female and two male, developed episodes of TCR during surgery (4/190; 2.1%). Three patients showed one episode of TCR just at the end of operation when the skin sutures were applied while CSI values were 70-77 and in the last case, when small tumor samples were taken from just beneath the lateral wall of the cavernous sinus TCR episode was seen while the CSI value was 51. Conclusion: TCR is a rare phenomenon during brain surgeries when patient is anesthetized using standard techniques. Keeping the adequate depth of anesthesia using CSI monitoring method may be an advisable strategy during whole period of a neurosurgical procedure. PMID:24083052

  19. Retrospective analysis showing the water method increased adenoma detection rate — a hypothesis generating observation

    PubMed Central

    Leung, Joseph W; Do, Lynne D; Siao-Salera, Rodelei M; Ngo, Catherine; Parikh, Dhavan A; Mann, Surinder K

    2011-01-01

    Background A water method developed to attenuate discomfort during colonoscopy enhanced cecal intubation in unsedated patients. Serendipitously a numerically increased adenoma detection rate (ADR) was noted. Objective To explore databases of sedated patients examined by the air and water methods to identify hypothesis-generating findings. Design: Retrospective analysis. Setting: VA endoscopy center. Patients: creening colonoscopy. Interventions: From 1/2000–6/2006 the air method was used - judicious air insufflation to permit visualization of the lumen to aid colonoscope insertion and water spray for washing mucosal surfaces. From 6/2006–11/2009 the water method was adopted - warm water infusion in lieu of air insufflation and suction removal of residual air to aid colonoscope insertion. During colonoscope withdrawal adequate air was insufflated to distend the colonic lumen for inspection, biopsy and polypectomy in a similar fashion in both periods. Main outcome measurements: ADR. Results The air (n=683) vs. water (n=495) method comparisons revealed significant differences in overall ADR 26.8% (183 of 683) vs. 34.9% (173 of 495) and ADR of adenomas >9 mm, 7.2% vs. 13.7%, respectively (both P<0.05, Fisher's exact test). Limitations: Non-randomized data susceptible to bias by unmeasured parameters unrelated to the methods. Conclusion Confirmation of the serendipitous observation of an impact of the water method on ADR provides impetus to call for randomized controlled trials to test hypotheses related to the water method as an approach to improving adenoma detection. Because of recent concerns over missed lesions during colonoscopy, the provocative hypothesis-generating observations warrant presentation. PMID:21686105

  20. Model-based observer: a gas turbine engine case study

    Microsoft Academic Search

    Oliver F. Qi; P. J. Gawthrop; N. R. L. Maccallum

    1992-01-01

    A model-based control approach to synthesizing a nonlinear controller for a single-spool gas turbine engine is described. Since the main control variable, engine thrust, cannot be directly measured, a model-based observer is considered to provide online estimation of the thrust for feedback control. Both proportional and proportional-integral (PI) observers have been used in the model-based observer design. The latter is

  1. A divergence-free method to extract observables from correlation functions

    NASA Astrophysics Data System (ADS)

    Qin, Si-xue

    2015-03-01

    Correlation functions provide information on the properties of mesons in vacuum and of hot nuclear matter. In this work, we present a new method to derive a well-defined spectral representation for correlation functions. Combining this method with the quark gap equation and the inhomogeneous Bethe-Salpeter equation in the rainbow-ladder approximation, we calculate in-vacuum masses of light mesons and the electrical conductivity of the quark-gluon plasma. The analysis can be extended to other observables of strong-interaction systems.

  2. Temperature Variability during Delirium in ICU Patients: An Observational Study

    PubMed Central

    van der Kooi, Arendina W.; Kappen, Teus H.; Raijmakers, Rosa J.; Zaal, Irene J.; Slooter, Arjen J. C.

    2013-01-01

    Introduction Delirium is an acute disturbance of consciousness and cognition. It is a common disorder in the intensive care unit (ICU) and associated with impaired long-term outcome. Despite its frequency and impact, delirium is poorly recognized by ICU-physicians and –nurses using delirium screening tools. A completely new approach to detect delirium is to use monitoring of physiological alterations. Temperature variability, a measure for temperature regulation, could be an interesting component to monitor delirium, but whether temperature regulation is different during ICU delirium has not yet been investigated. The aim of this study was to investigate whether ICU delirium is related to temperature variability. Furthermore, we investigated whether ICU delirium is related to absolute body temperature. Methods We included patients who experienced both delirium and delirium free days during ICU stay, based on the Confusion Assessment method for the ICU conducted by a research- physician or –nurse, in combination with inspection of medical records. We excluded patients with conditions affecting thermal regulation or therapies affecting body temperature. Daily temperature variability was determined by computing the mean absolute second derivative of the temperature signal. Temperature variability (primary outcome) and absolute body temperature (secondary outcome) were compared between delirium- and non-delirium days with a linear mixed model and adjusted for daily mean Richmond Agitation and Sedation Scale scores and daily maximum Sequential Organ Failure Assessment scores. Results Temperature variability was increased during delirium-days compared to days without delirium (?unadjusted=0.007, 95% confidence interval (CI)=0.004 to 0.011, p<0.001). Adjustment for confounders did not alter this result (?adjusted=0.005, 95% CI=0.002 to 0.008, p<0.001). Delirium was not associated with absolute body temperature (?unadjusted=-0.03, 95% CI=-0.17 to 0.10, p=0.61). This did not change after adjusting for confounders (?adjusted=-0.03, 95% CI=-0.17 to 0.10, p=0.63). Conclusions Our study suggests that temperature variability is increased during ICU delirium. PMID:24194955

  3. A Method to Retrieve Rainfall Rate Over Land from TRMM Microwave Imager Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Over tropical land regions, rain rate maxima in mesoscale convective systems revealed by the Precipitation Radar (PR) flown on the Tropical Rainfall Measuring Mission (TRMM) satellite are found to correspond to thunderstorms, i.e., Cbs. These Cbs are reflected as minima in the 85 GHz brightness temperature, T85, observed by the TRMM Microwave Imager (TMI) radiometer. Because the magnitude of TMI observations do not discriminate satisfactorily convective and stratiform rain, we developed here a different TMI discrimination method. In this method, two types of Cbs, strong and weak, are inferred from the Laplacian of T85 at minima. Then, to retrieve rain rate, where T85 is less than 270 K, a weak (background) rain rate is deduced using T85 observations. Furthermore, over a circular area of 10 km radius centered at the location of each T85 minimum, an additional Cb component of rain rate is added to the background rain rate. This Cb component of rain rate is estimated with the help of (T19-T37) and T85 observations. Initially, our algorithm is calibrated with the PR rain rate measurements from 20 MCS rain events. After calibration, this method is applied to TMI data taken from several tropical land regions. With the help of the PR observations, we show that the spatial distribution and intensity of rain rate over land estimated from our algorithm are better than those given by the current TMI-Version-5 Algorithm. For this reason, our algorithm may be used to improve the current state of rain retrievals on land.

  4. A Hilbert transform method for parameter identification of time-varying structures with observer techniques

    Microsoft Academic Search

    Zuo-Cai Wang; Wei-Xin Ren; Gen-Da Chen

    2012-01-01

    This paper presents a recursive Hilbert transform method for the time-varying property identification of large-scale shear-type buildings with limited sensor deployments. An observer technique is introduced to estimate the building responses from limited available measurements. For an n-story shear-type building with l measurements (l ? n), the responses of other stories without measurements can be estimated based on the first

  5. Space charge behavior under ac voltage in water-treed PE observed by the PEA method

    Microsoft Academic Search

    Ying Li; Jiro Kawai; Yasumitsu Ebinuma; Yasutaka Fujiwara; Yoshimichi Ohki; Yasuhiro Tanaka; Tatsuo Takada

    1997-01-01

    The pulsed electroacoustic method (PEA) has been applied to observe space charge formation under ac application (7 kVpk, 50, 0.1 and 0.001 Hz) in water-treed polyethylene samples in order to understand the degradation mechanism of water trees. A system with phase-resolving capability has been developed to measure the space charge distribution at any phase angle of the applied ac voltage.

  6. Improving resolution and depth of astronomical observations via modern mathematical methods for image analysis

    E-print Network

    Castellano, Marco; Fontana, Adriano; Merlin, Emiliano; Pilo, Stefano; Falcone, Maurizio

    2015-01-01

    In the past years modern mathematical methods for image analysis have led to a revolution in many fields, from computer vision to scientific imaging. However, some recently developed image processing techniques successfully exploited by other sectors have been rarely, if ever, experimented on astronomical observations. We present here tests of two classes of variational image enhancement techniques: "structure-texture decomposition" and "super-resolution" showing that they are effective in improving the quality of observations. Structure-texture decomposition allows to recover faint sources previously hidden by the background noise, effectively increasing the depth of available observations. Super-resolution yields an higher-resolution and a better sampled image out of a set of low resolution frames, thus mitigating problematics in data analysis arising from the difference in resolution/sampling between different instruments, as in the case of EUCLID VIS and NIR imagers.

  7. A learning-based method for image super-resolution from zoomed observations.

    PubMed

    Joshi, Manjunath V; Chaudhuri, Subhasis; Panuganti, Rajkiran

    2005-06-01

    We propose a technique for super-resolution imaging of a scene from observations at different camera zooms. Given a sequence of images with different zoom factors of a static scene, we obtain a picture of the entire scene at a resolution corresponding to the most zoomed observation. The high-resolution image is modeled through appropriate parameterization, and the parameters are learned from the most zoomed observation. Assuming a homogeneity of the high-resolution field, the learned model is used as a prior while super-resolving the scene. We suggest the use of either a Markov random field (MRF) or an simultaneous autoregressive (SAR) model to parameterize the field based on the computation one can afford. We substantiate the suitability of the proposed method through a large number of experimentations on both simulated and real data. PMID:15971920

  8. An Evaluation Method of the Effect of Observation Environment on Air Temperature Measurement

    NASA Astrophysics Data System (ADS)

    Kinoshita, Nobuyuki

    2014-07-01

    Near-surface air temperature is the most important variable in the climatic analysis of global warming. The air temperature near the surface is affected by the artificial surface (asphalt, concrete and buildings for example) surrounding the thermometer. However, there is no quantitative method for evaluating the observational environment. Therefore, a practical evaluation method with a scientific basis is required to aid observational network managers and data users. The magnitude of the artificial surface influence on the air temperature and its characteristics are investigated using numerical experiments with various road widths and wind speeds. The results show that the temperature increase in the lee of the road depends on the distance from the road, the road width, the wind speed and the thermal stratification and that the temperature increase can be estimated using an analytical footprint model. In order to estimate the largest value of the temperature increase, a function is developed from the footprint model; it depends on the normalized distance based on the road width, and thus can be calculated easily. A practical method using this function is proposed for the evaluation of the effect of the observational environment.

  9. Interpolation of Superconducting Gravity Observations Using Least-Squares Collocation Method

    NASA Astrophysics Data System (ADS)

    Habel, Branislav; Janak, Juraj

    2014-05-01

    A pre-processing of the gravity data measured by superconducting gravimeter involves removing of spikes, offsets and gaps. Their presence in observations can limit the data analysis and degrades the quality of obtained results. Short data gaps are filling by theoretical signal in order to get continuous records of gravity. It requires the accurate tidal model and eventually atmospheric pressure at the observed site. The poster presents a design of algorithm for interpolation of gravity observations with a sampling rate of 1 min. Novel approach is based on least-squares collocation which combines adjustment of trend parameters, filtering of noise and prediction. It allows the interpolation of missing data up to a few hours without necessity of any other information. Appropriate parameters for covariance function are found using a Bayes' theorem by modified optimization process. Accuracy of method is improved by the rejection of outliers before interpolation. For filling of longer gaps the collocation model is combined with theoretical tidal signal for the rigid Earth. Finally, the proposed method was tested on the superconducting gravity observations at several selected stations of Global Geodynamics Project. Testing demonstrates its reliability and offers results comparable with the standard approach implemented in ETERNA software package without necessity of an accurate tidal model.

  10. Funding sources for continuing medical education: An observational study

    PubMed Central

    Venkataraman, Ramesh; Ranganathan, Lakshmi; Ponnish, Arun S.; Abraham, Babu K.; Ramakrishnan, Nagarajan

    2014-01-01

    Aims: Medical accreditation bodies and licensing authorities are increasingly mandating continuing medical education (CME) credits for maintenance of licensure of healthcare providers. However, the costs involved in participating in these CME activities are often substantial and may be a major deterrent in obtaining these mandatory credits. It is assumed that healthcare providers often obtain sponsorship from their institutions or third party payers (i.e. pharmaceutical-industry) to attend these educational activities. Data currently does not exist exploring the funding sources for CME activities in India. In this study, we examine the relative proportion of CME activities sponsored by self, institution and the pharmaceutical-industry. We also wanted to explore the characteristics of courses that have a high proportion of self-sponsorship. Materials and Methods: This is a retrospective audit of the data during the year 2009 conducted at an autonomous clinical training academy. The details of the sponsor of each CME activity were collected from an existing database. Participants were subsequently categorized as sponsored by self, sponsored by institution or sponsored by pharmaceutical-industry. Results: In the year 2009, a total of 2235 participants attended 40 different CME activities at the training academy. Of the total participants, 881 (39.4%) were sponsored by self, 898 (40.2%) were sponsored by institution and 456 (20.3%) by pharmaceutical-industry. About 47.8% participants attended courses that carried an international accreditation. For the courses that offer international accreditation, 63.3% were sponsored by self, 34.9% were sponsored by institution and 1.6% were sponsored by pharmaceutical-industry. There were 126 participants (5.6%) who returned to the academy for another CME activity during the study period. Self-sponsored (SS) candidates were more likely to sponsor themselves again for subsequent CME activity compared with the other two groups (P < 0.001). Conclusions: In our study, majority of healthcare professionals attending CME activities were either self or institution sponsored. There was a greater inclination for self-sponsoring for activities with international accreditation. SS candidates were more likely to sponsor themselves again for subsequent CME activities. PMID:25136190

  11. Observer assessment of multi-pinhole SPECT geometries for prostate cancer imaging: a simulation study

    NASA Astrophysics Data System (ADS)

    Kalantari, Faraz; Sen, Anando; Gifford, Howard C.

    2014-03-01

    SPECT imaging using In-111 ProstaScint is an FDA-approved method for diagnosing prostate cancer metastases within the pelvis. However, conventional medium-energy parallel-hole (MEPAR) collimators produce poor image quality and we are investigating the use of multipinhole (MPH) imaging as an alternative. This paper presents a method for evaluating MPH designs that makes use of sampling-sensitive (SS) mathematical model observers for tumor detectionlocalization tasks. Key to our approach is the redefinition of a normal (or background) reference image that is used with scanning model observers. We used this approach to compare different MPH configurations for the task of small-tumor detection in the prostate and surrounding lymph nodes. Four configurations used 10, 20, 30, and 60 pinholes evenly spaced over a complete circular orbit. A fixed-count acquisition protocol was assumed. Spherical tumors were placed within a digital anthropomorphic phantom having a realistic Prostascint biodistribution. Imaging data sets were generated with an analytical projector and reconstructed volumes were obtained with the OSEM algorithm. The MPH configurations were compared in a localization ROC (LROC) study with 2D pelvic images and both human and model observers. Regular and SS versions of the scanning channelized nonprewhitening (CNPW) and visual-search (VS) model observers were applied. The SS models demonstrated the highest correlations with the average human-observer results

  12. Study on individual stochastic model of GNSS observations for precise kinematic applications

    NASA Astrophysics Data System (ADS)

    Próchniewicz, Dominik; Szpunar, Ryszard

    2015-04-01

    The proper definition of mathematical positioning model, which is defined by functional and stochastic models, is a prerequisite to obtain the optimal estimation of unknown parameters. Especially important in this definition is realistic modelling of stochastic properties of observations, which are more receiver-dependent and time-varying than deterministic relationships. This is particularly true with respect to precise kinematic applications which are characterized by weakening model strength. In this case, incorrect or simplified definition of stochastic model causes that the performance of ambiguity resolution and accuracy of position estimation can be limited. In this study we investigate the methods of describing the measurement noise of GNSS observations and its impact to derive precise kinematic positioning model. In particular stochastic modelling of individual components of the variance-covariance matrix of observation noise performed using observations from a very short baseline and laboratory GNSS signal generator, is analyzed. Experimental test results indicate that the utilizing the individual stochastic model of observations including elevation dependency and cross-correlation instead of assumption that raw measurements are independent with the same variance improves the performance of ambiguity resolution as well as rover positioning accuracy. This shows that the proposed stochastic assessment method could be a important part in complex calibration procedure of GNSS equipment.

  13. Method of Kinetic Thrust Measurement Using Observer of Linear Oscillatory Actuator

    NASA Astrophysics Data System (ADS)

    Mizuno, Tsutomu; Ohkubo, Mitsunori; Bu, Yinggang; Karasawa, Makoto; Nakagawa, Hiroshi; Muraguchi, Yosuke

    The kinetic thrust of a linear motor (LM) is measured with a load cell connected between the LM and a load motor. The case of linear oscillatory actuator (LOA), the kinetic thrust obtained using this method is not accurate, because the inertial force affects the load cell under the high-speed reciprocating motion of the LOA. In this paper, we propose a novel method of measuring kinetic thrust using an observer-inputted output of the load cell and the displacement of the load motor, and examine the proposed method. The estimated kinetic thrust Fe obtained by the observer agrees with the kinetic thrust obtained by simulation. In the measurement, the ratio of Fe to ?2KfI1 (Kf is the thrust constant of the LOA, I1 is the exciting current) is 0.93 at frequency f = 37.3Hz. Fe decreases with increasing frequency because of the eddy currents in the yokes of the LOA. Therefore, it is considered that the proposed method is appropriate, as ascertained by simulation and measurement. In addition, it is necessary for the leaf spring of the LOA to be light and to have a fixed spring constant for the high-precision measurement of kinetic thrust.

  14. Lateralization in motor facilitation during action observation: a TMS study

    Microsoft Academic Search

    Lisa Aziz-Zadeh; Fumiko Maeda; Eran Zaidel; John Mazziotta; Marco Iacoboni

    2002-01-01

    Action observation facilitates corticospinal excitability. This is presumably due to a premotor neural system that is active\\u000a when we perform actions and when we observe actions performed by others. It has been speculated that this neural system is\\u000a a precursor of neural systems subserving language. If this theory is true, we may expect hemispheric differences in the motor\\u000a facilitation produced

  15. Development and reliability of an observation method to assess food intake of young children in child care.

    PubMed

    Ball, Sarah C; Benjamin, Sara E; Ward, Dianne S

    2007-04-01

    To our knowledge, a direct observation protocol for assessing dietary intake among young children in child care has not been published. This article reviews the development and testing of a diet observation system for child care facilities that occurred during a larger intervention trial. Development of this system was divided into five phases, done in conjunction with a larger intervention study; (a) protocol development, (b) training of field staff, (c) certification of field staff in a laboratory setting, (d) implementation in a child-care setting, and (e) certification of field staff in a child-care setting. During the certification phases, methods were used to assess the accuracy and reliability of all observers at estimating types and amounts of food and beverages commonly served in child care. Tests of agreement show strong agreement among five observers, as well as strong accuracy between the observers and 20 measured portions of foods and beverages with a mean intraclass correlation coefficient value of 0.99. This structured observation system shows promise as a valid and reliable approach for assessing dietary intake of children in child care and makes a valuable contribution to the growing body of literature on the dietary assessment of young children. PMID:17383271

  16. Microscopic methods to observe the distribution of lipids in the cellular membrane.

    PubMed

    Takatori, Sho; Mesman, Rob; Fujimoto, Toyoshi

    2014-02-01

    Membrane lipids not only provide the structural framework of cellular membranes but also influence protein functions in several different ways. In comparison to proteins, however, relatively little is known about distribution of membrane lipids because of the insufficiency of microscopic methods. The difficulty in studying lipid distribution results from several factors, including their unresponsiveness to chemical fixation, fast translational movement, small molecular size, and high packing density. In this Current Topic, we consider the major microscopic methods and discuss whether and to what degree of precision these methods can reveal membrane lipid distribution in situ. We highlight two fixation methods, chemical and physical, and compare the theoretical limitations to their spatial resolution. Recognizing the strengths and weaknesses of each method should help researchers interpret their microscopic results and increase our understanding of the physiological functions of lipids. PMID:24460209

  17. A Method to Retrieve Rainfall Rate over Land from TRMM Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.

    2002-01-01

    Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) observations over mesoscale convective systems (MCSs) reveal that there are localized maxima in the rain rate with a scale of about 10 to 20 km that represent thunderstorms (Cbs). Some of these Cbs are developing or intense, while others are decaying or weak. These Cbs constitute only about 20 % of the rain area of a given MCS. Outside of Cbs, the average rain rate is much weaker than that within Cbs. From an analysis of the PR data, we find that the spatial distribution of rain and its character, convective or stratiform, is highly inhomogeneous. This complex nature of rain exists on a scale comparable to that of a Cb. The 85 GHz brightness temperature, T85, observations of the TRMM Microwave Imager (TMI) radiometer taken over an MCS reflect closely the PR rain rate pattern over land. Local maxima in rain rate shown by PR are observed as local minima in T85. Where there are no minima in T85, PR observations indicate there is light rain. However, the TMI brightness temperature measurements (Tbs) have poor ability to discriminate convective rain from stratiform rain. For this reason, a TMI rain retrieval procedure that depends primarily on the magnitude of Tbs performs poorly. In order to retrieve rain rate from TMI data on land one has to include the spatial distribution information deduced from the T85 data in the retrieval method. Then, quantitative estimation of rain rate can be accomplished. A TMI rain retrieval method developed along these lines can yield estimates of rain rate and its frequency distribution which agree closely with that given by PR. We find the current TRMM project TMI (Version 5) rain retrieval algorithm on land could be improved with the retrieval scheme developed here. To support the conceptual frame work of the rain retrieval method developed here, a theoretical analysis of the TMI brightness temperatures in convective and stratiform regions is presented.

  18. A new method of producing casts for anatomical studies.

    PubMed

    De Sordi, Nadia; Bombardi, Cristiano; Chiocchetti, Roberto; Clavenzani, Paolo; Trerè, Claudio; Canova, Marco; Grandis, Annamaria

    2014-09-01

    The objective of the present study was to verify if polyurethane foam is a suitable material to make accurate casts of vessels and viscera, and to develop a method based on its use for anatomical studies. This new technique has been tested primarily on the lungs of different animals, but also on the renal, intestinal and equine digital vessels. It consisted of three steps: specimen preparation, injection of the foam and corrosion of the cast. All structures injected with foam were properly filled. The bronchial tree and the vessels could be observed up to their finer branches. The method is inexpensive, simple and requires no special equipment. The pre-casting procedure does not require perfusion of the specimens with formalin, or prolonged flushing with carbon dioxide gas or air for drying. The polyurethane foam does not need a catalyst. It is simply diluted with acetone, which does not cause shrinkage of the cast due to evaporation during hardening. The foam naturally expands into the cavities without high pressure of the inoculum, and hardens in just 2 or 3 h at room temperature. Only two drawbacks were observed. The first is the fact that multiple injections cannot be made in the same cavity since the foam solidifies quickly; the second is the slight brittleness of the cast, due to the low elasticity of polyurethane foam. In conclusion, polyurethane foam was a suitable material for producing accurate casts of vessels and viscera. PMID:24788383

  19. A preliminary study on destriping techniques of PLANCK/LFI measurements versus observational strategy

    E-print Network

    C. Burigana; M. Malaspina; N. Mandolesi; L. Danse; D. Maino; M. Bersanelli; M. Maltoni

    1999-06-23

    We present here the basic issues of our simulations of PLANCK/LFI observations focussing on the study of the stripes generated by the 1/f noise, including realistic estimates of the 1/f knee frequency, based on the Seiffert et al. (1997) study of the properties of the PLANCK/LFI radiometers. The destriping method presented in the report on the PLANCK PHASE A study has been implemented to be applied to different scanning strategies with the freedom of choosing more or less stringent crossing conditions. Numerical methods for saving the amount of required RAM in the solution of the destriping linear system are presented. We provide preliminary results of the efficiency of this destriping technique for different scanning strategies. We focus here on methodological aspects and remind the reader to the Maino et al. (1999) paper (astro-ph/9906010) for further analyses and a more complete discussion.

  20. Methods for Composing Tradeoff Studies under Uncertainty 

    E-print Network

    Bily, Christopher

    2012-10-19

    Tradeoff studies are a common part of engineering practice. Designers conduct tradeoff studies in order to improve their understanding of how various design considerations relate to one another. Generally a tradeoff study involves a systematic multi...

  1. [Contrastive study on dynamic spectrum extraction method].

    PubMed

    Li, Gang; Zhou, Mei; Wang, Hui-quan; Xiong, Chan; Lin, Ling

    2012-05-01

    Dynamic spectrum method extracts the absorbance of the artery pulse blood with some wavelengths. The method can reduce some influence such as measurement condition, individual difference and spectrum overlap. It is a new way for noninvasive blood components detection However, how to choose a dynamic spectrum extraction method is one of the key links for the weak ingredient spectrum signal. Now there are two methods to extract the dynamic spectral signal-frequency domain analysis and single-trial estimation in time domain In the present research, comparison analysis and research on the two methods were carrued out completely. Theoretical analysis and experimental results show that the two methods extract the dynamic spectrum from different angles. But they are the same in essence--the basic principle of dynamic spectrum, the signal statistical and average properties. With the pulse wave of relative stable period and amplitude, high precision dynamic spectrum can be obtained by the two methods. With the unstable pulse wave due to the influence of finger shake and contact-pressure change, the dynamic spectrum extracted by single-trial estimation is more accurate than the one by frequecy domain analysis. PMID:22827082

  2. 78 FR 8152 - Proposed Collection; Comment Request: Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ...Comment Request: Women's Health Initiative...Observational Study SUMMARY: In...Title: The Women's Health Initiative...Observational Study. Type of Information...population of aging women. Frequency...Respondents: Study participants...physician's office...

  3. Comparison of Pooled Risk Estimates for Adverse Effects from Different Observational Study Designs: Methodological Overview

    PubMed Central

    Golder, Su; Loke, Yoon K.; Bland, Martin

    2013-01-01

    Background A diverse range of study designs (e.g. case-control or cohort) are used in the evaluation of adverse effects. We aimed to ascertain whether the risk estimates from meta-analyses of case-control studies differ from that of other study designs. Methods Searches were carried out in 10 databases in addition to reference checking, contacting experts, and handsearching key journals and conference proceedings. Studies were included where a pooled relative measure of an adverse effect (odds ratio or risk ratio) from case-control studies could be directly compared with the pooled estimate for the same adverse effect arising from other types of observational studies. Results We included 82 meta-analyses. Pooled estimates of harm from the different study designs had 95% confidence intervals that overlapped in 78/82 instances (95%). Of the 23 cases of discrepant findings (significant harm identified in meta-analysis of one type of study design, but not with the other study design), 16 (70%) stemmed from significantly elevated pooled estimates from case-control studies. There was associated evidence of funnel plot asymmetry consistent with higher risk estimates from case-control studies. On average, cohort or cross-sectional studies yielded pooled odds ratios 0.94 (95% CI 0.88–1.00) times lower than that from case-control studies. Interpretation Empirical evidence from this overview indicates that meta-analysis of case-control studies tend to give slightly higher estimates of harm as compared to meta-analyses of other observational studies. However it is impossible to rule out potential confounding from differences in drug dose, duration and populations when comparing between study designs. PMID:23977151

  4. A Comparison of Reconstruction Methods for the Estimation of Coronal Mass Ejections Kinematics Based on SECCHI/HI Observations

    NASA Astrophysics Data System (ADS)

    Mishra, Wageesh; Srivastava, Nandita; Davies, Jackie A.

    2014-04-01

    A study of the kinematics and arrival times of coronal mass ejections (CMEs) at Earth, derived from time-elongation maps (J-maps) constructed from STEREO/heliospheric imager (HI) observations, provides an opportunity to understand the heliospheric evolution of CMEs in general. We implement various reconstruction techniques, based on the use of time-elongation profiles of propagating CMEs viewed from single or multiple vantage points, to estimate the dynamics of three geo-effective CMEs. We use the kinematic properties, derived from analysis of the elongation profiles, as inputs to the Drag Based Model for the distance beyond which the CMEs cannot be tracked unambiguously in the J-maps. The ambient solar wind into which these CMEs, which travel with different speeds, are launched, is different. Therefore, these CMEs will evolve differently throughout their journey from the Sun to 1 AU. We associate the CMEs, identified and tracked in the J-maps, with signatures observed in situ near 1 AU by the WIND spacecraft. By deriving the kinematic properties of each CME, using a variety of existing methods, we assess the relative performance of each method for the purpose of space weather forecasting. We discuss the limitations of each method, and identify the major constraints in predicting the arrival time of CMEs near 1 AU using HI observations.

  5. Intraaortic Balloon Pump Counterpulsation and Cerebral Autoregulation: an observational study

    PubMed Central

    2010-01-01

    Background The use of Intra-aortic counterpulsation is a well established supportive therapy for patients in cardiac failure or after cardiac surgery. Blood pressure variations induced by counterpulsation are transmitted to the cerebral arteries, challenging cerebral autoregulatory mechanisms in order to maintain a stable cerebral blood flow. This study aims to assess the effects on cerebral autoregulation and variability of cerebral blood flow due to intra-aortic balloon pump and inflation ratio weaning. Methods Cerebral blood flow was measured using transcranial Doppler, in a convenience sample of twenty patients requiring balloon counterpulsation for refractory cardiogenic shock (N = 7) or a single inotrope to maintain mean arterial pressure following an elective placement of an intra-aortic balloon pump for cardiac surgery (N = 13). Simultaneous blood pressure at the aortic root was recorded via the intra-aortic balloon pump. Cerebral blood flow velocities were recorded for six minute intervals at a 1:1 balloon inflation-ratio (augmentation of all cardiac beats) and during progressive reductions of the inflation-ratio to 1:3 (augmentation of one every third cardiac beat). Real time comparisons of peak cerebral blood flow velocities with systolic blood pressure were performed using cross-correlation analysis. The primary endpoint was assessment of cerebral autoregulation using the time delay between the peak signals for cerebral blood flow velocity and systolic blood pressure, according to established criteria. The variability of cerebral blood flow was also assessed using non-linear statistics. Results During the 1:1 inflation-ratio, the mean time delay between aortic blood pressure and cerebral blood flow was -0.016 seconds (95% CI: -0.023,-0.011); during 1:3 inflation-ratio mean time delay was significantly longer at -0.010 seconds (95% CI: -0.016, -0.004, P < 0.0001). Finally, upon return to a 1:1 inflation-ratio, time delays recovered to those measured at baseline. During inflation-ratio reduction, cerebral blood flow irregularities reduced over time, whilst cerebral blood flow variability at end-diastole decreased in patients with cardiogenic shock. Conclusions Weaning counterpulsation from 1:1 to 1:3 inflation ratio leads to a progressive reduction in time delays between systolic blood pressure and peak cerebral blood flow velocities suggesting that although preserved, there is a significant delay in the establishment of cerebral autoregulatory mechanisms. In addition, cerebral blood flow irregularities (i.e. surrogate of flow adaptability) decrease and a loss of cerebral blood flow chaotic pattern occurs during the end-diastolic phase of each beat in patients with cardiogenic shock. PMID:20226065

  6. Observational Studies Randomized Controlled Experiments Principles of Experimental Design Random Samples Case Study Producing Data

    E-print Network

    Watkins, Joseph C.

    hemisphere, all Africanized honey bees are descended from this apiary. When the time arrives for replacing of bacteria? 4 / 16 #12;Observational Studies Randomized Controlled Experiments Principles of Experimental or levels that will be used in the treatment. Example. A breeding experiment using African and European bees

  7. Studies of sodar?observed dot echo structures

    Microsoft Academic Search

    S. P. Singal; B. S. Gera; S. K. Aggarwal

    1985-01-01

    During moist weather under stably stratified and light wind conditions very often “dot” shaped echoes, either distributed randomly or arranged in a stratified layer, have been observed on sodar echograms. They last from a couple of hours to ten hours. Their horizontal widths are up to 200 m while their vertical sizes are up to 40 m. It is argued

  8. Taguchi methods in electronics: A case study

    NASA Technical Reports Server (NTRS)

    Kissel, R.

    1992-01-01

    Total Quality Management (TQM) is becoming more important as a way to improve productivity. One of the technical aspects of TQM is a system called the Taguchi method. This is an optimization method that, with a few precautions, can reduce test effort by an order of magnitude over conventional techniques. The Taguchi method is specifically designed to minimize a product's sensitivity to uncontrollable system disturbances such as aging, temperature, voltage variations, etc., by simultaneously varying both design and disturbance parameters. The analysis produces an optimum set of design parameters. A 3-day class on the Taguchi method was held at the Marshall Space Flight Center (MSFC) in May 1991. A project was needed as a follow-up after the class was over, and the motor controller was selected at that time. Exactly how to proceed was the subject of discussion for some months. It was not clear exactly what to measure, and design kept getting mixed with optimization. There was even some discussion about why the Taguchi method should be used at all.

  9. Taguchi methods in electronics: A case study

    NASA Astrophysics Data System (ADS)

    Kissel, R.

    1992-05-01

    Total Quality Management (TQM) is becoming more important as a way to improve productivity. One of the technical aspects of TQM is a system called the Taguchi method. This is an optimization method that, with a few precautions, can reduce test effort by an order of magnitude over conventional techniques. The Taguchi method is specifically designed to minimize a product's sensitivity to uncontrollable system disturbances such as aging, temperature, voltage variations, etc., by simultaneously varying both design and disturbance parameters. The analysis produces an optimum set of design parameters. A 3-day class on the Taguchi method was held at the Marshall Space Flight Center (MSFC) in May 1991. A project was needed as a follow-up after the class was over, and the motor controller was selected at that time. Exactly how to proceed was the subject of discussion for some months. It was not clear exactly what to measure, and design kept getting mixed with optimization. There was even some discussion about why the Taguchi method should be used at all.

  10. Application of GPS radio occultation method for observation of the internal waves in the atmosphere

    Microsoft Academic Search

    Y. A. Liou; A. G. Pavelyev; J. Wickert; S. F. Liu; A. A. Pavelyev; T. Schmidt; K. Igarashi

    2006-01-01

    In this study, we show that the amplitude radio occultation (RO) method, which employs high-precision global positioning system (GPS) signals, allows one to determine the vertical gradients of refractivity and monitor wave structures in the atmosphere on a global scale at altitudes ranging from 10 to 40 km. We show that the sensitivity of the RO amplitude data to the

  11. ICESat Observations of Inland Surface Water Stage, Slope, and Extent: a New Method for Hydrologic Monitoring

    NASA Technical Reports Server (NTRS)

    Harding, David J.; Jasinski, Michael F.

    2004-01-01

    River discharge and changes in lake, reservoir and wetland water storage are critical terms in the global surface water balance, yet they are poorly observed globally and the prospects for adequate observations from in-situ networks are poor (Alsdorf et al., 2003). The NASA-sponsored Surface Water Working Group has established a framework for advancing satellite observations of river discharge and water storage changes which focuses on obtaining measurements of water surface height (stage), slope, and extent. Satellite laser altimetry, which can achieve centimeter-level elevation precision for single, small laser footprints, provides a method to obtain these inland water parameters and contribute to global water balance monitoring. Since its launch in January, 2003 the Ice, Cloud, and land Elevation Satellite (ICESat), a NASA Earth Observing System mission, has achieved over 540 million laser pulse observations of ice sheet, ocean surface, land topography, and inland water elevations and cloud and aerosol height distributions. By recording the laser backscatter from 80 m diameter footprints spaced 175 m along track, ICESat acquires globally-distributed elevation profiles, using a 1064 nm laser altimeter channel, and cloud and aerosol profiles, using a 532 nm atmospheric lidar channel. The ICESat mission has demonstrated the following laser altimeter capabilities relevant to observations of inland water: (1) elevation measurements with a precision of 2 to 3 cm for flat surfaces, suitable for detecting river surface slopes along long river reaches or between multiple crossings of a meandering river channel, (2) from the laser backscatter waveform, detection of water surface elevations beneath vegetation canopies, suitable for measuring water stage in flooded forests, (3) single pulse absolute elevation accuracy of about 50 cm (1 sigma) for 1 degree sloped surfaces, with calibration work in progress indicating that a final accuracy of about 12 cm (1 sigma) will be achieved for clear atmosphere conditions, suitable for detection of stage changes through time, (4) ability to precisely point the spacecraft so as to position the laser profile on the Earth the surface with a cross-track accuracy of 50 m (1 sigma), enabling small water bodies and specific locations to be targeted and re-observed through time, (5) adequate signal levels from specular water surfaces up to 5 degrees off-nadir, enabling complete global access to any location on the Earth's surface from the ICESat repeat orbit by off-nadir pointing, and (6) day and night operation with successful laser ranging to the Earth's surface through thin to moderate cloud cover, enabling more frequent measurements than can be achieved by passive optical sensors. Here we illustrate these capabilities by showing ICESat observations through time for selected river and lake locations.

  12. Image color reduction method for color-defective observers using a color palette composed of 20 particular colors

    NASA Astrophysics Data System (ADS)

    Sakamoto, Takashi

    2015-01-01

    This study describes a color enhancement method that uses a color palette especially designed for protan and deutan defects, commonly known as red-green color blindness. The proposed color reduction method is based on a simple color mapping. Complicated computation and image processing are not required by using the proposed method, and the method can replace protan and deutan confusion (p/d-confusion) colors with protan and deutan safe (p/d-safe) colors. Color palettes for protan and deutan defects proposed by previous studies are composed of few p/d-safe colors. Thus, the colors contained in these palettes are insufficient for replacing colors in photographs. Recently, Ito et al. proposed a p/dsafe color palette composed of 20 particular colors. The author demonstrated that their p/d-safe color palette could be applied to image color reduction in photographs as a means to replace p/d-confusion colors. This study describes the results of the proposed color reduction in photographs that include typical p/d-confusion colors, which can be replaced. After the reduction process is completed, color-defective observers can distinguish these confusion colors.

  13. Cruciferous vegetables intake and the risk of colorectal cancer: a meta-analysis of observational studies

    PubMed Central

    Wu, Q. J.; Yang, Y.; Vogtmann, E.; Wang, J.; Han, L. H.; Li, H. L.; Xiang, Y. B.

    2013-01-01

    Background Epidemiological studies have reported inconsistent associations between cruciferous vegetable (CV) intake and colorectal cancer (CRC) risk. To our knowledge, a comprehensive and quantitative assessment of the association between CV intake and CRC has not been reported. Methods Relevant articles were identified by searching MEDLINE. We pooled the relative risks (RR) from individual studies using a random-effect model and carried out heterogeneity and publication bias analyses. Results Twenty-four case–control and 11 prospective studies were included in our analysis. When all studies were pooled, we yielded a significantly inverse association between CV (RR: 0.82; 95% confidence interval 0.75–0.90) intake and CRC risk. Specific analysis for cabbage and broccoli yielded similar result. When separately analyzed, case–control studies of CV intake yield similar results, and the results from the prospective studies showed borderline statistical significance. Moreover, significant inverse associations were also observed in colon cancer and its distal subsite both among prospective and case–control studies. Conclusions Findings from this meta-analysis provide evidence that high intake of CV was inversely associated with the risk of CRC and colon cancer in humans. Further analysis on other specific CV, food preparation methods, stratified results by anatomic cancer site, and subsite of colon cancer should be extended in future study. PMID:23211939

  14. A Study on Delaunay Terminal Edge Method

    Microsoft Academic Search

    Maria-cecilia Rivara

    2006-01-01

    The Delaunay terminal edge algorithm for triangulation improvement proceeds by iterative Lepp selection of a point M which is midpoint of a Delaunay terminal edge in the mesh. The longest edge bisection of the associated terminal triangles\\u000a (sharing the terminal edge) can be seen as a first step in the Delaunay insertion of M. The method was introduced as a

  15. Automated method for study of drug metabolism

    NASA Technical Reports Server (NTRS)

    Furner, R. L.; Feller, D. D.

    1973-01-01

    Commercially available equipment can be modified to provide automated system for assaying drug metabolism by continuous flow-through. System includes steps and devices for mixing drug with enzyme and cofactor in the presence of pure oxygen, dialyzing resulting metabolite against buffer, and determining amount of metabolite by colorimetric method.

  16. Obstacle Avoidance Method Study of Electric Wheelchair

    Microsoft Academic Search

    Tian Zhihong; Xu Wenhui; Liu Xiuhong

    2009-01-01

    Analyzing the characteristics of various sensors, a method of detecting obstacle and avoiding obstacle used in electric wheelchair is presented based on the requirement of electric wheelchair obstacle avoidance. Transmitting circuit which is composed by 555 timing chip and receiving circuit which is utilized by LM393 are designed for measuring ultrasonic distance. Receiving program with ADuC842 which makes use of

  17. Methods for Studying Tank Armament Materials.

    ERIC Educational Resources Information Center

    Rogov, I. V.

    This translation from the Russian contains discussions on the most expedient sequence for presenting problems in firing training for military tank crews, methods of learning, and the practices and actions which can be recommended to training supervisors. The document is an attempt to summarize and systematize materials; it also presents advice and…

  18. LAT observation of GRBs: Simulations and Sensitivity studies

    SciTech Connect

    Omodei, Nicola [INFN of Pisa, Polo Fibonacci Largo B. Pontecorvo 3, Pisa, 56127 (Italy); Norris, Jay [University of Denver, Denver CO 80208 (United States)

    2007-07-12

    The GLAST Large Area Telescope (LAT) is the next generation satellite experiment for high-energy gamma-ray astronomy. It employs a pair conversion technique to record photons in the energy range from 20 MeV to more than 300 GeV. The LAT will follow the steps from its predecessor EGRET (1991-2000), and will explore the high-energy gamma-ray sky with unprecedented capabilities. The observation of Gamma-Ray Bursts is one of the main science goal of the LAT: in this contribution we compute an estimation of the LAT sensitivity to GRB, adopting a phenomenological description of GRBs, where the high-energy emission in GRB is obtained extrapolating the observed BATSE spectrum up to LAT energies. The effect of the cosmological attenuation is included. We use the BATSE current catalog to build up our statistics.

  19. Using a Two-Staged Propensity Score Matching Strategy and Multilevel Modeling to Estimate Treatment Effects in a Multisite Observational Study

    ERIC Educational Resources Information Center

    Rickles, Jordan H.

    2012-01-01

    The study is designed to demonstrate and test the utility of the proposed two-stage matching method compared to other analytic methods traditionally employed for multisite observational studies. More specifically, the study addresses the following research questions: (1) How do different specifications of the matching method influence covariate…

  20. Cerebral Aneurysm Multicenter European Onyx (CAMEO) Trial: Results of a Prospective Observational Study in 20 European Centers

    Microsoft Academic Search

    Andrew J. Molyneux; Saruhan Cekirge; Isil Saatci; Gyula Gal

    BACKGROUND AND PURPOSE: This study was designed to investigate the safety and efficacy of the Onyx liquid embolic system in treating a selected population of patients with intracranial aneurysms that presented difficulties for surgical or endovascular alternatives. METHODS: A prospective observational study was conducted in 20 European centers enroll- ing a consecutive series of 119 patients with 123 aneurysms judged

  1. A wavelet-based method for extracting intermittent discontinuities observed in human motor behavior.

    PubMed

    Inoue, Yasuyuki; Sakaguchi, Yutaka

    2015-02-01

    Human motor behavior often shows intermittent discontinuities even when people try to follow a continuously moving target. Although most previous studies revealed common characteristics of this "motor intermittency" using frequency analysis, this technique is not always appropriate because the nature of the intermittency is not stationary, i.e., the temporal intervals between the discontinuities may vary irregularly. In the present paper, we propose a novel method for extracting intermittent discontinuities using a continuous wavelet transform (CWT). This method is equivalent to the detection of peak of the jerk profile in principle, but it successfully and stably detects discontinuities using the amplitude and phase information of the complex wavelet transform. More specifically, the singularity point on the time-scale plane plays a key role in detecting the discontinuities. Another important feature is that the proposed method does not require parameter tuning because it is based on the nature of hand movement. In addition, this method does not contain any optimization process, which avoids explosive increase in computational cost for long time-series data. The performance of the proposed method was examined using an artificial trajectory composed of several primitive movements, and an actual hand trajectory in a continuous target-tracking task. The functional rationale of the proposed method is discussed. PMID:24866293

  2. Optical correlation method for studying disperse media

    NASA Astrophysics Data System (ADS)

    Angelsky, O. V.; Maksimyak, P. P.

    1993-10-01

    This paper presents a simple and reproducible optical correlation technique that uses the measurement of the transverse field coherence function in a particle image plane to determine the particle size distribution function of light scattering particles. The method can also be applied to nonspherical particles by using the equivalent particle approximation and the equivalent particle radius in the calculations. Experimental results from characterization of media containing Lycopodium spores, Microcystis aeroginosa cells, and erythrocytes are presented.

  3. Study Methods to Standardize Thermography NDE

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Workman, Gary L.

    1998-01-01

    The purpose of this work is to develop thermographic inspection methods and standards for use in evaluating structural composites and aerospace hardware. Qualification techniques and calibration methods are investigated to standardize the thermographic method for use in the field. Along with the inspections of test standards structural hardware, support hardware is designed and fabricated to aid in the thermographic process. Also, a standard operating procedure is developed for performing inspections with the Bales Thermal Image Processor (TIP). Inspections are performed on a broad range of structural composites. These materials include graphite/epoxies, graphite/cyanide-ester, graphite/silicon-carbide, graphite phenolic and Kevlar/epoxy. Also metal honeycomb (titanium and aluminum faceplates over an aluminum honeycomb core) structures are investigated. Various structural shapes are investigated and the thickness of the structures vary from as few as 3 plies to as many as 80 plies. Special emphasis is placed on characterizing defects in attachment holes and bondlines, in addition to those resulting from impact damage and the inclusion of foreign matter. Image processing through statistical analysis and digital filtering is investigated to enhance the quality and quantify the NDE thermal images when necessary.

  4. Study Methods to Standardize Thermography NDE

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Workman, Gary L.

    1998-01-01

    The purpose of this work is to develop thermographic inspection methods and standards for use in evaluating structural composites and aerospace hardware. Qualification techniques and calibration methods are investigated to standardize the thermographic method for use in the field. Along with the inspections of test standards structural hardware, support hardware is designed and fabricated to aid in the thermographic process. Also, a standard operating procedure is developed for performing inspections with the Bales Thermal Image Processor (TIP). Inspections are performed on a broad range of structural composites. These materials include various graphite/epoxies, graphite/cyanide-ester, graphite/silicon-carbide, graphite phenolic and Keviar/epoxy. Also metal honeycomb (titanium and aluminum faceplates over an aluminum honeycomb core) structures are investigated. Various structural shapes are investigated and the thickness of the structures vary from as few as 3 plies to as many as 80 plies. Special emphasis is placed on characterizing defects in attachment holes and bondlines, in addition to those resulting from impact damage and the inclusion of foreign matter. Image processing through statistical analysis and digital filtering is investigated to enhance the quality and quantify the NDE thermal images when necessary.

  5. A new modelling method for non-convex shapes of asteroids based on photometric observations

    NASA Astrophysics Data System (ADS)

    Bartczak, P.; Santana-Ros, T.; Marciniak, A.; Micha?owski, T.; Pr?tka-Ziomek, H.

    2014-04-01

    We present the new SAGE algorithm (Shaping Asteroids with Genetic Evolution) able to derive 3-D nonconvex shapes of asteroids and solving for their spin parameters using only disk-integrated photometry. A triangular mesh of 62 vertices is used as a seed during the parameters minimization, and the Catmull-Clark method is applied to generate bodies with higher resolution. The subroutines search for the sidereal period of rotation in a given range, and the spin axis orientation on the whole celestial sphere. A step-iterative algorithm is used to make the shape evolve under the minimization constrains between the synthetic generated photometry and the real observations. In order to generate the simulated lightcurves we propose the virtual frames algorithm. The algorithm simulates the pictures visible on hypothetical CCD frames and, using only elementary vector operations or quadratic algebraic equations, it takes into account all phase angle effects. Publicly available lightcurve data has been used to obtain a new non-convex model for (9) Metis and (433) Eros. The resulting body shapes are compared with the ones obtained using other observational techniques, such as adaptive optics and stellar occultations (for Metis) or the NEAR Shoemaker observations of Eros during its rendezvous.

  6. Observation and studies of double J /? production at the Tevatron

    NASA Astrophysics Data System (ADS)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, V. N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Savitskyi, M.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.

    2014-12-01

    We present the observation of doubly produced J /? mesons with the D0 detector at Fermilab in p p ¯ collisions at ?{s }=1.96 TeV . The production cross section for both singly and doubly produced J /? mesons is measured using a sample with an integrated luminosity of 8.1 fb-1 . For the first time, the double J /? production cross section is separated into contributions due to single and double parton scatterings. Using these measurements, we determine the effective cross section ?eff, a parameter characterizing an effective spatial area of the parton-parton interactions and related to the parton spatial density inside the nucleon.

  7. Observational and Modeling Studies of Clouds and the Hydrological Cycle

    NASA Technical Reports Server (NTRS)

    Somerville, Richard C. J.

    1997-01-01

    Our approach involved validating parameterizations directly against measurements from field programs, and using this validation to tune existing parameterizations and to guide the development of new ones. We have used a single-column model (SCM) to make the link between observations and parameterizations of clouds, including explicit cloud microphysics (e.g., prognostic cloud liquid water used to determine cloud radiative properties). Surface and satellite radiation measurements were used to provide an initial evaluation of the performance of the different parameterizations. The results of this evaluation will then used to develop improved cloud and cloud-radiation schemes, which were tested in GCM experiments.

  8. Unbiased Causal Inference from an Observational Study: Results of a Within-Study Comparison

    ERIC Educational Resources Information Center

    Pohl, Steffi; Steiner, Peter M.; Eisermann, Jens; Soellner, Renate; Cook, Thomas D.

    2009-01-01

    Adjustment methods such as propensity scores and analysis of covariance are often used for estimating treatment effects in nonexperimental data. Shadish, Clark, and Steiner used a within-study comparison to test how well these adjustments work in practice. They randomly assigned participating students to a randomized or nonrandomized experiment.…

  9. Association between Dairy Intake and Gastric Cancer: A Meta-Analysis of Observational Studies

    PubMed Central

    Tian, Shu-bo; Yu, Jian-chun; Kang, Wei-ming; Ma, Zhi-qiang; Ye, Xin; Cao, Zhan-jiang

    2014-01-01

    Purpose Observational studies have given inconsistent findings on the relationship between intake of dairy products and gastric cancer. We therefore conducted a systematic review with a meta-analysis of observational studies to summarize available evidence on this point. Methods We searched the electronic literature databases of PubMed (Medline), EMBASE and the Chinese Biomedical Literature Database up until August 30, 2013. All studies were limited to the English language. Random-effects models were used to pool study results between dairy products consumption and the risk of gastric cancer. We also performed subgroup, publication bias and sensitivity analysis. Results Eight prospective studies and 18 case-control studies were included in our analysis, with a total number of 7272 gastric cancer cases and 223,355 controls. Pooled relative risks of all studies showed no significant association between dairy intake and gastric cancer (odds ratio [OR]: 1.09, 95% confidence interval [CI]: 0.96–1.25). When study design was separately analyzed, population-based case-control studies showed a positive association between dairy intake and gastric cancer risk (OR: 1.36; 95% CI: 1.07–1.74), whereas no associations were shown by hospital-based case-control studies (OR: 0.86, 95% CI: 0.72–1.02) or cohort studies (OR?=?1.01, 95% CI?=?0.91–1.13). Conclusions The meta-analysis shows that no clear association apparently exists between consumption of dairy products and gastric cancer risk. Further well-designed cohort and intervention studies should be conducted to verify this lack of association. PMID:25006674

  10. Making the most of LBTI nulling interferometry observations using a statistical data reduction method

    NASA Astrophysics Data System (ADS)

    Marion, L.; Mennesson, B.; Defrère, D.; Hinz, P.; Absil, O.

    2014-03-01

    A unique and completely new statistical reduction method was recently proposed by Hanot et al. (2011) to improve the accuracy on interferometric null measurements. The main idea behind this method is to consider the full statistical distribution of the measured null depth and to reproduce it as the sum of three terms: (i) the astrophysical null, (ii) the backgroundrelated null, and (iii) a random contribution related to all instrumental imperfections (phase difference, intensity mismatch, polarisation errors, etc). For the latter two terms, we assume that we can directly inject the distributions of the measurable quantities (individual beam intensities and background) in the model, and that the phase difference can be modeled by a Gaussian distribution, from which we create random phase sequences. This results in three free parameters in our model: the astrophysical null, the mean phase difference and its standard deviation. We explore a certain range of values for these parameters and for each triplet, we build several random theoretical null histograms that we compare to the observed one using a least squares method. Finally, the best estimators for the three parameters are obtained by minimizing the chi square. In this talk, we will show how this statistical method has been used at the Palomar Fiber Nuller to gain a factor of 10 in the accuracy on the measured astrophysical null, compared to classical data reduction / calibration methods. We will then explain how we plan to adapt it to the LBTI/NOMIC nulling interferometer to reach unprecedented sensitivity levels in terms of detectable exozodiacal disks. First results based on LBTI/NOMIC data will be presented.

  11. Direct Observation, Study, and Control of Molecular Superrotors

    NASA Astrophysics Data System (ADS)

    Korobenko, Aleksey; Milner, Alexander A.; Milner, Valery

    2014-03-01

    Extremely fast rotating molecules whose rotational energy is comparable with the molecular bond strength are known as "superrotors." It has been speculated that superrotors may exhibit a number of unique properties, yet only indirect evidence of these molecular objects has been reported to date. Here we demonstrate the first direct observation of molecular superrotors by detecting coherent unidirectional molecular rotation with extreme frequencies exceeding 10 THz. The technique of an "optical centrifuge" is used to control the degree of rotational excitation in an ultrabroad range of rotational quantum numbers, reaching as high as N =95 in oxygen and N=60 in nitrogen. State-resolved detection enables us to determine the shape of the excited rotational wave packet and quantify the effect of centrifugal distortion on the rotational spectrum. Femtosecond time resolution reveals coherent rotational dynamics with increasing coherence times at higher angular momentum. We demonstrate that molecular superrotors can be created and observed in dense samples under normal conditions where the effects of ultrafast rotation on many-body interactions, intermolecular collisions, and chemical reactions can be readily explored.

  12. Direct observation, study and control of molecular super rotors

    NASA Astrophysics Data System (ADS)

    Korobenko, Aleksey; Milner, Alexander; Hepburn, John; Milner, Valery

    2014-05-01

    Extremely fast rotating molecules whose rotational energy is comparable with or exceeds the molecular bond strength are known as ``super rotors''. It has been speculated that super rotors may exhibit a number of unique properties, yet only indirect evidence of these molecular objects has been reported to date. We demonstrate the first direct observation of molecular super rotors by detecting coherent unidirectional molecular rotation with extreme frequencies exceeding 10 THz. The technique of an ``optical centrifuge'' is used to control the degree of rotational excitation in an ultra-broad range of rotational quantum numbers, reaching as high as N = 95 in oxygen and N = 60 in nitrogen. State-resolved detection enables us to determine the shape of the excited rotational wave packet and quantify the effect of centrifugal distortion on the rotational spectrum. Femtosecond time resolution reveals coherent rotational dynamics with increasing coherence times at higher angular momentum. We demonstrate that molecular super rotors can be created and observed in dense samples under normal conditions where the effects of ultrafast rotation on many-body interactions, inter-molecular collisions and chemical reactions can be readily explored.

  13. Microfabrication methods for the study of chemotaxis

    E-print Network

    Shur, Maiya, 1980-

    2004-01-01

    We have developed a system for studying chemotaxis in a microfabricated system. The goal was to develop a system capable of generating spatially and temporally stable concentration gradients of a chemotactic molecule while ...

  14. AN APPROACH TO METHODS DEVELOPMENT FOR HUMAN EXPOSURE ASSESSMENT STUDIES

    EPA Science Inventory

    Human exposure assessment studies require methods that are rapid, cost-effective and have a high sample through-put. The development of analytical methods for exposure studies should be based on specific information for individual studies. Human exposure studies suggest that di...

  15. Periodontal Disease and Risk of Chronic Obstructive Pulmonary Disease: A Meta-Analysis of Observational Studies

    PubMed Central

    Zeng, Xian-Tao; Tu, Ming-Li; Liu, Dong-Yan; Zheng, Dong; Zhang, Jing; Leng, WeiDong

    2012-01-01

    Background Many epidemiological studies have found a positive association between periodontal disease (PD) and risk of chronic obstructive pulmonary disease (COPD), but this association is varied and even contradictory among studies. We performed a meta-analysis to ascertain the relationship between PD and COPD. Methods PubMed and Embase database were searched up to January 10, 2012, for relevant observational studies on the association between PD and risk of COPD. Data from the studies selected were extracted and analyzed independently by two authors. The meta-analysis was performed using the Comprehensive Meta-Analysis software. Results Fourteen observational studies (one nested case-control, eight case-control, and five cross-sectional) involving 3,988 COPD patients were yielded. Based on random-effects meta-analysis, a significant association between PD and COPD was identified (odds ratio?=?2.08, 95% confidence interval?=?1.48–2.91; P<0.001), with sensitivity analysis showing that the result was robust. Subgroups analyses according to study design, ethnicity, assessment of PD/COPD, and adjusted/unadjusted odds ratios also revealed a significant association. Publication bias was detected. Conclusions Based on current evidence, PD is a significant and independent risk factor of COPD. However, whether a causal relationships exists remains unclear. Morever, we suggest performing randomized controlled trails to explore whether periodontal interventions are beneficial in regulating COPD pathogenesis and progression. PMID:23094025

  16. Experiments offer more reliable evidence on causation than observational studies, which is not to gainsay the contribution to knowledge from observation. Experi-

    E-print Network

    Sekhon, Jasjeet S.

    Experiments offer more reliable evidence on causation than observational studies, which is not to gainsay the contribution to knowledge from observation. Experi- ments should be analyzed as experiments, models, experiments, observational studies, intention-to-treat, per-protocol, treatment

  17. Modified Conditional Merging technique: a new method to estimate a rainfall field combining remote sensed data and raingauge observations

    NASA Astrophysics Data System (ADS)

    Pignone, Flavio; Rebora, Nicola; Silvestro, Francesco

    2015-04-01

    The estimation of the rainfall field, especially its spatial distribution and position, is a crucial task both for rainfall nowcasting and for modeling catchment response to rainfall. Some studies of literature about multisensor datafusion prove that combining data from different sensors (especially raingauges and radar) represents the best way to obtain an enhanced ad more reliable estimation of QPE and of the associated river discharge. Sinclair and Peagram (2004) have proposed the Conditional Merging (CM) technique, a merging algorithm which extract the information content from the observed data and use it within an interpolation method to obtain the rainfall maps. The raingauges provide a punctual measure of the observed "real" rainfall while the remote sensors (radar network or satellite constellation) supply rainfall estimation maps which give an idea of the spatial correlation structure of the observed field. In this work is studied an enhanced algorithm based on CM, called Modified Conditional Merging, which can be used in real-time to produce the optimal rainfall maps. The area of interest, where the CM has been applied, is Italy, where are both available a dense network of raingauge measurements (about 3000 stations) and a QPE estimated by the Italian Radar composite. The main innovation respect to classical CM is to estimate the structure of covariance and the length of spatial correlation ?, for every raingauge, directly from the cumulated radar rainfall fields. The advantages of this method is to estimate the local characteristic of the domain to obtain information at smaller scale, very useful for convective events. A cross-validation of the new method was done and several statistical scores were applied on the results. The validation on a large number of Italian past event along with its operational use are presented and discussed.

  18. Birth weight of offspring and mortality in the Renfrew and Paisley study: prospective observational study

    Microsoft Academic Search

    George Davey Smith; Carole Hart; Catherine Ferrell; Mark Upton; David Hole; Victor Hawthorne; Graham Watt

    1997-01-01

    AbstractObjective: To investigate the association between birth weight of offspring and mortality among fathers and mothers in the west of Scotland.Design: Prospective observational study.Participants: 794 married couples in Renfrew district of the west of Scotland.Main outcome measures: Mortality from all causes and from cardiovascular disease over 15 year follow up.Results: Women who had heavier babies were taller, had higher body

  19. Theoretical and Observational Studies of the Central Engines of AGN

    NASA Technical Reports Server (NTRS)

    Sivron, Ran

    1995-01-01

    In Active Galactic Nuclei (AGN) the luminosity is so intense that the effect of radiation pressure on a particle may exceed the gravitational attraction. It was shown that when such luminosities are reached, relatively cold (not completely ionized) thermal matter clouds may form in the central engines of AGN, where most of the luminosity originates. We show that the spectrum of emission from cold clouds embedded in hot relativistic matter is similar to the observed spectrum. We also show that within the hot relativistic matter, cold matter moves faster than the speed of sound or the Alfven speed, and shocks form. The shocks provide a mechanism by which a localized perturbation can propagate throughout the central engine. The shocked matter can emit the observed luminosity, and can explain the flux and spectral variability. It may also provide an efficient mechanism for the outward transfer of angular momentum and provide the outward flow of winds. With observations from X-ray satellites, emission features from the cold and hot matter may be revealed. Our analysis of X-ray data from the Seyfert 1 galaxy MCG - 6-30-15 over five years using detectors on the Ginga and Rosat satellites, revealed some interesting variable features. A source with hot matter emits non-thermal radiation which is Compton reflected from cold matter and then absorbed by warm (partially ionized) absorbing matter in the first model, which can be fit to the data if both the cold and warm absorbers are near the central engine. An alternative model in which the emission from the hot matter is partially covered by very warm matter (in which all elements except Iron are mostly ionized) is also successful. In this model the cold and warm matter may be at distances of up to 100 times the size of the central engine, well within the region where broad optical lines are produced. The flux variability is more naturally explained by the second model. Our results support the existence of cold matter in, or near, the central engine of MCG -6-30-15. Cold matter in the central engine, and evidence of the effects of shocks, is probably forthcoming with future X-ray satellites.

  20. Numerical spherical aberration correction method using spatial light modulator under deep-part fluorescence observation

    NASA Astrophysics Data System (ADS)

    Takiguchi, Yu; Takamoto, Hisayoshi; Kanada, Masamitsu; Inoue, Takashi; Matsumoto, Naoya; Terakawa, Susumu

    2014-03-01

    We have developed a confocal fluorescence laser scanning microscopy (CFLSM) incorporating a liquid crystal on silicon spatial light modulator (LCOS-SLM). To achieve high-resolution and high-contrast imaging for deeper part of the tissue with CFLSM, high numerical aperture objective lenses are required to tightly focus excitation light to meet Rayleigh limit(criterion) for the specimens. However, mismatch of refractive index at the boundary of interfacing materials, such as atmosphere, glass cover, and biological tissues, causes spherical aberration. Recently, we proposed a numerical method for correcting spherical aberration. In this method a pre-distorted wavefront pattern for aberration correction is calculated by ray tracing from a hypothetical focal point inside a specimen to the pupil plane. The resulting microscope can correct such spherical aberration. We observed 6.0?m fluorescent micro-beads dispersed three-dimensionally in agarose gel to confirm effectiveness of aberration correction. We reconstructed a three-dimensional image by taking 20 images by changing the depth with 1 ?m interval and stacking them. It was apparent that the longitudinal/depth resolution was improved and that the intensity of fluorescence image was increased with aberration correction. While this method is applicable to other laser scanning microscopes, it has potential to enhance the signals for various super-resolution microscopic techniques, such as stimulated- emission-depletion (STED) fluorescence microscopy.

  1. Applying Agile Methods to the Development of a Community-Based Sea Ice Observations Database

    NASA Astrophysics Data System (ADS)

    Pulsifer, P. L.; Collins, J. A.; Kaufman, M.; Eicken, H.; Parsons, M. A.; Gearheard, S.

    2011-12-01

    Local and traditional knowledge and community-based monitoring programs are increasingly being recognized as an important part of establishing an Arctic observing network, and understanding Arctic environmental change. The Seasonal Ice Zone Observing Network (SIZONet, http://www.sizonet.org) project has implemented an integrated program for observing seasonal ice in Alaska. Observation and analysis by local sea ice experts helps track seasonal and inter-annual variability of the ice cover and its use by coastal communities. The ELOKA project (http://eloka-arctic.org) is collaborating with SIZONet on the development of a community accessible, Web-based application for collecting and distributing local observations. The SIZONet project is dealing with complicated qualitative and quantitative data collected from a growing number of observers in different communities while concurrently working to design a system that will serve a wide range of different end users including Arctic residents, scientists, educators, and other stakeholders with a need for sea ice information. The benefits of linking and integrating knowledge from communities and university-based researchers are clear, however, development of an information system in this multidisciplinary, multi-participant context is challenging. Participants are geographically distributed, have different levels of technical expertise, and have varying goals for how the system will be used. As previously reported (Pulsifer et al. 2010), new technologies have been used to deal with some of the challenges presented in this complex development context. In this paper, we report on the challenges and innovations related to working as a multi-disciplinary software development team. Specifically, we discuss how Agile software development methods have been used in defining and refining user needs, developing prototypes, and releasing a production level application. We provide an overview of the production application that includes discussion of a hybrid architecture that combines a traditional relational database, schema-less database, advanced free text search, and the preliminary framework for Semantic Web support. The current version of the SIZONet web application is discussed in relation to the high-value features defined as part of the Agile approach. Preliminary feedback indicates a system that meets the needs of multiple user groups.

  2. A study of Saturn's 3 micron window from ISO observations

    NASA Astrophysics Data System (ADS)

    Lellouch, E.; Kleiner, I.; Fouchet, T.; Bézard, B.

    The infrared spectrum of Jupiter and Saturn displays a 3-micron window extending from 2 6 to 3 2 micron and limited on both sides by strong absorption from CH4 and in Jupiter s case by absorption from NH3 ice High S N observations of this region were obtained in 1996 by the Short-Wavelength Spectrometer of ISO at a spectral resolution of about 1500 In addition to numerous CH4 lines the Saturn spectrum shows several absorption bands due to PH3 notably at 2 92 and 3 02 micron for which molecular parameters have recently become available We will present an analysis of this spectrum hoping to get information on the PH3 abundance and vertical profile and searching for the signatures of other gases and of ammonia ice

  3. An observational and theoretical study of highly supercooled altocumulus

    NASA Technical Reports Server (NTRS)

    Heymsfield, Andrew J.; Miloshevich, Larry M.; Slingo, Anthony; Sassen, Kenneth; Starr, David O'C.

    1991-01-01

    The microphysics of two altocumulus clouds sampled at a temperature of about -30 C through the NCAR King Air aircraft and coincident lidar has been characterized. The clouds are structurally similar to stratocumulus and have extensive cloudtop entrainment, a capping temperature inversion, and a dry layer above. Microphysical and radiative properties of both clouds have been modeled numerically. When entrainment effects are incorporated in the model, calculations of droplet concentration and mean diameter profiles compare favorably with the measurements. Radiative transfer calculations indicate that radiative cooling causes sufficient negative buoyancy in cloudtop parcels for producing convective instability and reproducing the observed downdraft velocities. It is shown that entrainment of warmer, drier air near a cloudtop counteracts the radiatively induced negative buoyancy in the downdrafts.

  4. STACEE observations of Markarian 421 above 100 GeV and a new method for high-energy spectral analysis

    NASA Astrophysics Data System (ADS)

    Carson, Jennifer Elaine

    Markarian 421 is a nearby (z =0.03) blazar that is actively studied to constrain both physical blazar models and models of the extragalactic background light. The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE), a wavefront- sampling detector sensitive to ~ 100 GeV gamma rays, detected Mkn 421 during a multiwavelength campaign in early 2004. This thesis covers the 2004 STACEE observations of Mkn 421 and their analysis. The goal of the project was to measure the gamma-ray spectrum of Mkn 421; such a spectral result would be STACEE's first and one of the first from any detector in STACEE's energy range. Achieving this goal required the development of a new method for reconstructing gamma-ray energies from the STACEE data. The reconstruction method is described in detail, and the resulting spectrum is presented. Finally, the implications of the results for understanding high-energy emission mechanisms in AGN are discussed.

  5. The Study of Observer Variation in the Radiological Classification of Pneumoconiosis

    PubMed Central

    Fay, J. W. J.; Ashford, J. R.

    1960-01-01

    In a long-term investigation such as the National Coal Board's Pneumoconiosis Field Research (P.F.R.), it is essential to establish satisfactory and stable procedures for making the necessary observations and measurements. It is equally important regularly to apply suitable methods of checking the accuracy and consistency of the various observations and measurements. One aspect of vital importance in the P.F.R. is the classification of the series of chest radiographs taken, at intervals, of all the men under observation. This is inevitably a subjective process, and (as with other similar fields of work) it is desirable to obtain some understanding of the basic process behind the operation. This can usefully be done by the help of “models” designed to describe the process, if necessary in simplified terms. The problem of the radiological classification of pneumoconiosis has been studied hitherto in terms of coefficients of disagreement (inter-observer variation) and inconsistency (intra-observer variation), but for various reasons the method was not considered entirely satisfactory. New methods of approach were therefore developed for studying the performance of the two doctors responsible for the film reading in the Research, and two distinct “models” were derived. The advantages and disadvantages of each are described in the paper, together with the applications of the two models to the study of some of the problems arising in the course of the investigation. The first model is based on the assumption that if a film is selected at random from a batch representing a whole colliery population, and that if the film is of “true” category i, the chance of its being read as another category (j) is a constant, Pij, which depends upon the observer concerned, the particular batch of films being read, and the values of i and j. This model enables the performance of the readers to be monitored satisfactorily, and it has also been used to investigate different methods for arriving at an agreed, or “definitive”, assessment of radiological abnormality. The Pij model suffers from the disadvantage of applying only to “average” films, and the assumptions made are such that it manifestly does not provide an entirely realistic representation of the reading process on any particular film. The second “improved” model was therefore developed to overcome this criticism. Briefly, it is considered that each film is representative of a unique degree of abnormality, located on a continuum, or abnormality scale, which covers the whole range of simple pneumoconiosis. The scale of abnormality is then chosen in such a way that, whatever the true degree of abnormality of the film, the observer's readings will be normally distributed about the true value with constant bias and variability at all points along the scale. The very large number of readings available has been analysed to determine the optimum positions of the category boundaries on the abnormality scale and in this way the scale has been unambiguously defined. The model enables the routine reading standards to be monitored, and it has also been used to investigate the underlying distribution of abnormality at individual collieries. Its chief disadvantage is the extensive computational work required. The “fit” of both models to the data collected in the Research is shown to be satisfactory and on balance it appears that both have applications in this field of study. The method chosen in any given circumstance will depend upon the particular requirement and the facilities available for computational work. PMID:13698433

  6. Tongue Inspection in TCM: Observations in a Study Sample of Patients Living with HIV

    PubMed Central

    Chang, Michelle; Quinn, Jessica; Capili, Bernadette

    2014-01-01

    Abstract Background: One of the principal diagnostic methods in Traditional Chinese Medicine (TCM) is the inspection of the tongue. This method involves examination of the shape, size, color, and texture of the tongue body and coat and helps reveal the state of organ functions and progression of conditions. Literature on tongue observations for patients who have human immunodeficiency virus (HIV) is minimal. Objective: The goal of this study was to provide a clinical “snapshot” of initial tongue assessments of 159 patients living with HIV, who participated in an acupuncture clinical trial for chronic nausea. The aim was to explore the similarities and differences observed in tongue assessments. Design: This study was part of a prospective, randomized, controlled, double-blinded (subjects and evaluators), parallel-groups, acupuncture clinical trial for treating chronic nausea. Setting: The study was conducted at a large urban New York City academic health center. Patients: The patients in this study were 159 individuals who had HIV infections and who had histories of chronic nausea for ?3 months. Main Outcome Measures: Initial tongue assessments were recorded for seven basic characteristics: (1) tongue color; (2) tongue shape; (3) tongue body quality; (4) coat color; (5) coat weight; (6) coat surface; and (7) tongue action. Results: The overall tongue picture seen in these patients was that the tongue was swollen and toothmarked, had a pink body with cracks, and had a thick, dry white coat. Conclusions: The HIV disease itself and the use of long term medications affect the Blood, Qi, Yin, and Yang. The observation of the tongue provides a window into the process of the disease and, ultimately, insight for clinical care. This sample population snapshot illustrates the complex processes seen in long-term chronic conditions managed by pharmacologic medications. PMID:24761186

  7. Using Qualitative Methods to Study Friendships

    ERIC Educational Resources Information Center

    Bukowski, William; Lisboa, Carolina

    2005-01-01

    Basic concepts and procedures of qualitative analysis are discussed, especially as they relate to the study of the features, processes, and effects of friendships. The contributions of the previous chapters are presented according to theory and research on friendship as a developmental process.

  8. Method for Studying Helicopter Longitudinal Maneuver Stability

    NASA Technical Reports Server (NTRS)

    Amer, Kenneth B

    1954-01-01

    A theoretical analysis of helicopter maneuver stability is made and the results are compared with experimental results for both a single and a tandem rotor helicopter. Techniques are described for measuring in flight the significant stability derivatives for use with the theory to aid in design studies of means for achieving marginal maneuver stability for a prototype helicopter.

  9. Offshore observations of eastern red bats (Lasiurus borealis) in the Mid-Atlantic United States using multiple survey methods.

    PubMed

    Hatch, Shaylyn K; Connelly, Emily E; Divoll, Timothy J; Stenhouse, Iain J; Williams, Kathryn A

    2013-01-01

    Little is known about the migration and movements of migratory tree-roosting bat species in North America, though anecdotal observations of migrating bats over the Atlantic Ocean have been reported since at least the 1890s. Aerial surveys and boat-based surveys of wildlife off the Atlantic Seaboard detected a possible diurnal migration event of eastern red bats (Lasiurus borealis) in September 2012. One bat was sighted approximately 44 km east of Rehoboth Beach, Delaware during a boat-based survey. Eleven additional bats were observed between 16.9 and 41.8 km east of New Jersey, Delaware, and Virginia in high definition video footage collected during digital aerial surveys. Observations were collected incidentally as part of a large baseline study of seabird, marine mammal, and sea turtle distributions and movements in the offshore environment. Digital survey methods also allowed for altitude estimation for several of these bats at >100 m above sea level. These observations provide new evidence of bat movements offshore, and offer insight into their flight heights above sea level and the times of day at which such migrations may occur. PMID:24367614

  10. Offshore Observations of Eastern Red Bats (Lasiurus borealis) in the Mid-Atlantic United States Using Multiple Survey Methods

    PubMed Central

    Hatch, Shaylyn K.; Connelly, Emily E.; Divoll, Timothy J.; Stenhouse, Iain J.; Williams, Kathryn A.

    2013-01-01

    Little is known about the migration and movements of migratory tree-roosting bat species in North America, though anecdotal observations of migrating bats over the Atlantic Ocean have been reported since at least the 1890s. Aerial surveys and boat-based surveys of wildlife off the Atlantic Seaboard detected a possible diurnal migration event of eastern red bats (Lasiurus borealis) in September 2012. One bat was sighted approximately 44 km east of Rehoboth Beach, Delaware during a boat-based survey. Eleven additional bats were observed between 16.9 and 41.8 km east of New Jersey, Delaware, and Virginia in high definition video footage collected during digital aerial surveys. Observations were collected incidentally as part of a large baseline study of seabird, marine mammal, and sea turtle distributions and movements in the offshore environment. Digital survey methods also allowed for altitude estimation for several of these bats at >100 m above sea level. These observations provide new evidence of bat movements offshore, and offer insight into their flight heights above sea level and the times of day at which such migrations may occur. PMID:24367614

  11. Covariate Balance in Bayesian Propensity Score Approaches for Observational Studies

    ERIC Educational Resources Information Center

    Chen, Jianshen; Kaplan, David

    2015-01-01

    Bayesian alternatives to frequentist propensity score approaches have recently been proposed. However, few studies have investigated their covariate balancing properties. This article compares a recently developed two-step Bayesian propensity score approach to the frequentist approach with respect to covariate balance. The effects of different…

  12. OBSERVATIONS ON THE STATE OF MARINE DISEASE STUDIES

    EPA Science Inventory

    State of marine disease studies is described. erhaps the greatest area of success in the last 20 years has been in the identification and characterization of viruses, bacteria, fungi, protozoan and metazoan disease agents. pening of new areas of investigation such as that of inte...

  13. An Observational Study of Co-Rumination in Adolescent Friendships

    ERIC Educational Resources Information Center

    Rose, Amanda J.; Schwartz-Mette, Rebecca A.; Glick, Gary C.; Smith, Rhiannon L.; Luebbe, Aaron M.

    2014-01-01

    Co-rumination is a dyadic process between relationship partners that refers to excessively discussing problems, rehashing problems, speculating about problems, mutual encouragement of problem talk, and dwelling on negative affect. Although studies have addressed youths' "tendency" to co-ruminate, little is known about the nature of…

  14. Ocean observing satellite study: instrument and satellite constellation architecture options

    NASA Technical Reports Server (NTRS)

    Gerber, A. J.; McGuire, J.; Cunningham, J. D.; Pichel, W. G.

    2002-01-01

    This paper provides: (1) an overview of the set of active and passive instruments identified by the IPO designed to make the ocean measurements including visible and infrared medium and high resolution imagers, radiometers, altimeters, and synthetic aperture radars and (2) the instrument and satellite constellation architecture options studied, and their ability to meet the set of measurement requirements.

  15. Observational study of 14 cases of chronic pancreatitis in dogs

    Microsoft Academic Search

    P. J. Watson; J. Archer; A. J. Roulois; T. J. Scase; M. E. Herrtage

    2010-01-01

    This study reports the clinical, clinicopathological and ultrasonographic findings from dogs with chronic pancreatitis (CP). Fourteen dogs with clinical signs consistent with CP and histological confirmation of the disease were evaluated. Abdominal ultrasound and clinical pathology results were recorded. Sensitivities of pancreatic enzymes for diagnosis of CP were calculated with two different cut-off values. The mean age of affected dogs

  16. Predicting Three Dimensions of Residential Curbside Recycling: An Observational Study.

    ERIC Educational Resources Information Center

    Oskamp, Stuart; Burkhardt, Rachel L.; Schultz, P. Wesley; Hurin, Sharrilyn; Zelezny, Lynnette

    1998-01-01

    Three dependent variables of household recycling behavior were studied in a suburban community over eight weeks, 10 independent variables serving as predictors. Results indicate that many of the independent variables that predicted recycling behavior in past research have weaker relationships in current, more convenient curbside programs.…

  17. Staff Reactions to Challenging Behaviour: An Observation Study

    ERIC Educational Resources Information Center

    Lambrechts, Greet; Van Den Noortgate, Wim; Eeman, Lieve; Maes, Bea

    2010-01-01

    Staff reactions play an important role in the development and maintaining of clients' challenging behaviour. Because there is a paucity of research on staff reactions in naturalistic settings, this study examined sequential associations between challenging behaviour and staff reactions by means of a descriptive analysis. We analysed video…

  18. Observational Study on Initiation and Acceleration of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Zhang, Jie

    2005-01-01

    During the performance period, we have successfully carried out all the tasks and fulfilled all the scientific objectives outlined in the proposal, which are about building a C1 Ch4E catalog and studying CME accelerations in both inner and outer corona.

  19. An efficient method of exploring simulation models by assimilating literature and biological observational data.

    PubMed

    Hasegawa, Takanori; Nagasaki, Masao; Yamaguchi, Rui; Imoto, Seiya; Miyano, Satoru

    2014-07-01

    Recently, several biological simulation models of, e.g., gene regulatory networks and metabolic pathways, have been constructed based on existing knowledge of biomolecular reactions, e.g., DNA-protein and protein-protein interactions. However, since these do not always contain all necessary molecules and reactions, their simulation results can be inconsistent with observational data. Therefore, improvements in such simulation models are urgently required. A previously reported method created multiple candidate simulation models by partially modifying existing models. However, this approach was computationally costly and could not handle a large number of candidates that are required to find models whose simulation results are highly consistent with the data. In order to overcome the problem, we focused on the fact that the qualitative dynamics of simulation models are highly similar if they share a certain amount of regulatory structures. This indicates that better fitting candidates tend to share the basic regulatory structure of the best fitting candidate, which can best predict the data among candidates. Thus, instead of evaluating all candidates, we propose an efficient explorative method that can selectively and sequentially evaluate candidates based on the similarity of their regulatory structures. Furthermore, in estimating the parameter values of a candidate, e.g., synthesis and degradation rates of mRNA, for the data, those of the previously evaluated candidates can be utilized. The method is applied here to the pharmacogenomic pathways for corticosteroids in rats, using time-series microarray expression data. In the performance test, we succeeded in obtaining more than 80% of consistent solutions within 15% of the computational time as compared to the comprehensive evaluation. Then, we applied this approach to 142 literature-recorded simulation models of corticosteroid-induced genes, and consequently selected 134 newly constructed better models. The method described here was found to be capable of efficiently exploring candidate simulation models and obtaining better models within a short span of time. Furthermore, the results suggest that there may be room for improvement in literature recorded pathways and that they can be systematically updated using biological observational data. PMID:24907678

  20. Thermal and nonthermal hard X-ray source sizes in solar flares obtained from RHESSI observations. I. Observations and evaluation of methods

    NASA Astrophysics Data System (ADS)

    Warmuth, A.; Mann, G.

    2013-04-01

    Context. In solar flares, a large amount of thermal and nonthermal energy is released impulsively in the form of heated plasma and accelerated particles. These processes can be studied via hard X-ray (HXR) diagnostics. In addition to spectroscopic observations, a thorough understanding of the thermal and nonthermal particle populations requires the knowledge of the HXR source sizes. Aims: We derive the geometric source parameters of both thermal coronal sources and the nonthermal HXR footpoints in solar flares. We compare and evaluate four different methods for obtaining source sizes, and then derive the most reliable source sizes, as well as the systematic uncertainties. Methods: We obtained time series of HXR images for 24 flares from GOES class C3.4 to X17.2 using the RHESSI instrument. The four imaging techniques employed are CLEAN, Pixon, visibility forward fit, and MEM_NJIT. From this data set, we derived the geometric parameters of the thermal HXR sources and the nonthermal footpoints. Using the different imaging techniques allowed us to quantify systematic measurement uncertainties. Results: We find that the different methods give consistent results on HXR source sizes. The correlations are very good for the thermal sources, and somewhat lower for the footpoints. The MEM_NJIT algorithm gives systematically smaller sizes than the other methods, possibly a result of over-resolution. Thermal source volumes are in the range of 2 × 1025-1.2 × 1028 cm3 (with a median relative uncertainty of 30%), and nonthermal footpoint areas in the range of 2 × 1016-6 × 1017 cm2 (median relative uncertainty: 40%). The thermal volumes of our sample are in the same range as those derived for microflares, which would imply that source size is not an important parameter for flare energetics. Conclusions: Using different imaging algorithms for determining HXR source sizes offers the advantage that uncertainties can be better quantified thus making the derived parameters more reliable. Combined with geometric parameters that were derived as time series in a larger number of flares, this will allow the study of the scaling relations and the temporal evolution of thermal and nonthermal HXR sources.

  1. HEALTHY study rationale, design and methods

    PubMed Central

    2009-01-01

    The HEALTHY primary prevention trial was designed and implemented in response to the growing numbers of children and adolescents being diagnosed with type 2 diabetes. The objective was to moderate risk factors for type 2 diabetes. Modifiable risk factors measured were indicators of adiposity and glycemic dysregulation: body mass index ?85th percentile, fasting glucose ?5.55 mmol l-1 (100 mg per 100 ml) and fasting insulin ?180 pmol l-1 (30 ?U ml-1). A series of pilot studies established the feasibility of performing data collection procedures and tested the development of an intervention consisting of four integrated components: (1) changes in the quantity and nutritional quality of food and beverage offerings throughout the total school food environment; (2) physical education class lesson plans and accompanying equipment to increase both participation and number of minutes spent in moderate-to-vigorous physical activity; (3) brief classroom activities and family outreach vehicles to increase knowledge, enhance decision-making skills and support and reinforce youth in accomplishing goals; and (4) communications and social marketing strategies to enhance and promote changes through messages, images, events and activities. Expert study staff provided training, assistance, materials and guidance for school faculty and staff to implement the intervention components. A cohort of students were enrolled in sixth grade and followed to end of eighth grade. They attended a health screening data collection at baseline and end of study that involved measurement of height, weight, blood pressure, waist circumference and a fasting blood draw. Height and weight were also collected at the end of the seventh grade. The study was conducted in 42 middle schools, six at each of seven locations across the country, with 21 schools randomized to receive the intervention and 21 to act as controls (data collection activities only). Middle school was the unit of sample size and power computation, randomization, intervention and primary analysis. PMID:19623188

  2. Genetic methods for studying lignin degradation

    Microsoft Academic Search

    P. Broda; M. MacDonald; U. Raeder; R. Liwicki; R. Haylock; A. McCarthy; A. Paterson; O. Birch; E. Peace; L. Ramsey; I. Cookson

    1984-01-01

    The white-rot fungiPhanerochaete chrysosporium andSporotrichum pulverulentum are now the classic lignin degrading organisms.P. chrysosporium is the better characterized with respect to the physiology of lignin degradation, whereasS. pulverulentum has been extensively studied to determine the mechanism of cellulose degradation and lignin-related aromatic metabolism.\\u000a The organisms are very similar and some workers consider thatP. chrysosporium is the perfect form of a

  3. Diffusive shock acceleration in oblique MHD shocks comparison with Monte Carlo methods and observations

    E-print Network

    Kang, H; Kang, Hyesung

    1996-01-01

    We report simulations of diffusive particle acceleration in oblique magnetohydrodynamical (MHD) shocks. These calculations are based on extension to oblique shocks of a numerical model for ``thermal leakage'' injection of particles at low energy into the cosmic-ray population. That technique, incorporated into a fully dynamical diffusion-convection formalism, was recently introduced for parallel shocks by Kang \\& Jones (1995). Here, we have compared results of time dependent numerical simulations using our technique with Monte Carlo simulations by Ellison, Baring \\& Jones 1995 and with {\\it in situ} observations from the Ulysses spacecraft of oblique interplanetary shocks discussed by Baring \\etal (1995). Through the success of these comparisons we have demonstrated that our {diffusion-convection} method and injection techniques provide a practical tool to capture essential physics of the injection process and particle acceleration at oblique MHD shocks. In addition to the diffusion-convection simulat...

  4. A novel “sandwich” method for observation of the keyhole in deep penetration laser welding

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Chen, Genyu; Wei, Haiying; Zhang, Jun

    2008-02-01

    A sandwich method was used to observe the keyhole in deep penetration laser welding, which provided an effective way to analyze both the Fresnel and inverse Bremsstrahlung absorption. In the transparent metal-analog system, different densities of metal vapor, ionized atoms, and free electrons in the keyhole can be simulated by changing the thickness of aluminum films. The research results show that inverse Bremsstrahlung absorption exerts a tremendous influence on the energy absorption of the laser beam for CO 2 laser welding. Low density of keyhole plasma benefits the incident laser energy coupling to the materials. However, excess density of keyhole plasma baffles the transmission of the incident laser beam to the interior material. By comparing inflow energy and outflow energy, there exits an energy balance on the keyhole wall by balancing the absorbed laser intensity and heat flux on the wall.

  5. A Dynamic Scheduling Method of Earth-Observing Satellites by Employing Rolling Horizon Strategy

    PubMed Central

    Dishan, Qiu; Chuan, He; Jin, Liu; Manhao, Ma

    2013-01-01

    Focused on the dynamic scheduling problem for earth-observing satellites (EOS), an integer programming model is constructed after analyzing the main constraints. The rolling horizon (RH) strategy is proposed according to the independent arriving time and deadline of the imaging tasks. This strategy is designed with a mixed triggering mode composed of periodical triggering and event triggering, and the scheduling horizon is decomposed into a series of static scheduling intervals. By optimizing the scheduling schemes in each interval, the dynamic scheduling of EOS is realized. We also propose three dynamic scheduling algorithms by the combination of the RH strategy and various heuristic algorithms. Finally, the scheduling results of different algorithms are compared and the presented methods in this paper are demonstrated to be efficient by extensive experiments. PMID:23690742

  6. Physical and dynamical studies of meteors. [radar observation of fragmentation

    NASA Technical Reports Server (NTRS)

    Southworth, R. B.; Sekanina, Z.

    1974-01-01

    Distribution of meteors in streams detected in the synoptic-year meteor sample plus a study of the fragmentation characteristics of the synoptic-year meteor sample are presented. Population coefficients and dispersion coefficients were determined for each meteor stream. These two parameters serve to determine the number of definite members of the stream in the sample used, and to estimate the actual space density of meteor streams. From results of the fragmentation study, it appears that the main body of most radar meteors does not ablate fragments layer by layer, but collapses rather suddenly under dynamic pressures on the order of 0,0002 dynes/cm. Furthermore, it is believed that fragmentation does not cause a serious selection effect in the radar meteor data.

  7. Observational Study and Parameterization of Aerosol-fog Interactions

    NASA Astrophysics Data System (ADS)

    Duan, J.; Guo, X.; Liu, Y.; Fang, C.; Su, Z.; Chen, Y.

    2014-12-01

    Studies have shown that human activities such as increased aerosols affect fog occurrence and properties significantly, and accurate numerical fog forecasting depends on, to a large extent, parameterization of fog microphysics and aerosol-fog interactions. Furthermore, fogs can be considered as clouds near the ground, and enjoy an advantage of permitting comprehensive long-term in-situ measurements that clouds do not. Knowledge learned from studying aerosol-fog interactions will provide useful insights into aerosol-cloud interactions. To serve the twofold objectives of understanding and improving parameterizations of aerosol-fog interactions and aerosol-cloud interactions, this study examines the data collected from fogs, with a focus but not limited to the data collected in Beijing, China. Data examined include aerosol particle size distributions measured by a Passive Cavity Aerosol Spectrometer Probe (PCASP-100X), fog droplet size distributions measured by a Fog Monitor (FM-120), Cloud Condensation Nuclei (CCN), liquid water path measured by radiometers and visibility sensors, along with meteorological variables measured by a Tethered Balloon Sounding System (XLS-?) and Automatic Weather Station (AWS). The results will be compared with low-level clouds for similarities and differences between fogs and clouds.

  8. Comparison of two inversion methods for retrieval of soil moisture and surface roughness from polarimetric radar observation of soil surfaces

    Microsoft Academic Search

    Yisok Oh

    2004-01-01

    This paper presents comparison of the direct inversion method (DIM) and the genetic algorithm-based inversion method (GAIM) for retrieval of soil moisture and surface roughness from polarimetric radar observation of soil surfaces. Those inversion methods are based on the polarimetric semiempirical model (PSEM), which was developed empirically to estimate the backscattering coefficients from the volumetric soil moisture content and the

  9. Integrative methods for studying cardiac energetics.

    PubMed

    Diolez, Philippe; Deschodt-Arsac, Véronique; Calmettes, Guillaume; Gouspillou, Gilles; Arsac, Laurent; Dos Santos, Pierre; Jais, Pierre; Haissaguerre, Michel

    2015-01-01

    The more recent studies of human pathologies have essentially revealed the complexity of the interactions involved at the different levels of integration in organ physiology. Integrated organ thus reveals functional properties not predictable by underlying molecular events. It is therefore obvious that current fine molecular analyses of pathologies should be fruitfully combined with integrative approaches of whole organ function. It follows an important issue in the comprehension of the link between molecular events in pathologies, and whole organ function/dysfunction is the development of new experimental strategies aimed at the study of the integrated organ physiology. Cardiovascular diseases are a good example as heart submitted to ischemic conditions has to cope both with a decreased supply of nutrients and oxygen, and the necessary increased activity required to sustain whole body-including the heart itself-oxygenation.By combining the principles of control analysis with noninvasive (31)P NMR measurement of the energetic intermediates and simultaneous measurement of heart contractile activity, we developed MoCA (for Modular Control and Regulation Analysis), an integrative approach designed to study in situ control and regulation of cardiac energetics during contraction in intact beating perfused isolated heart (Diolez et al., Am J Physiol Regul Integr Comp Physiol 293(1):R13-R19, 2007). Because it gives real access to integrated organ function, MoCA brings out a new type of information-the "elasticities," referring to internal responses to metabolic changes-that may be a key to the understanding of the processes involved in pathologies. MoCA can potentially be used not only to detect the origin of the defects associated with the pathology, but also to provide the quantitative description of the routes by which these defects-or also drugs-modulate global heart function, therefore opening therapeutic perspectives. This review presents selected examples of the applications to isolated intact beating heart and a wider application to cardiac energetics under clinical conditions with the direct study of heart pathologies. PMID:25631023

  10. A new method of observing weak extended x-ray sources with RHESSI

    E-print Network

    Iain G. Hannah; Gordon J. Hurford; Hugh S. Hudson; Robert P. Lin

    2007-02-08

    We present a new method, fan-beam modulation, for observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). This space-based solar x-ray and gamma-ray telescope has much greater sensitivity than previous experiments in the 3-25 keV range, but is normally not well suited to detecting extended sources since their signal is not modulated by RHESSI's rotating grids. When the spacecraft is offpointed from the target source, however, the fan-beam modulation time-modulates the transmission by shadowing resulting from exploiting the finite thickness of the grids. In this paper we detail how the technique is implemented and verify its consistency with sources with clear known signals that have occurred during RHESSI offpointing: microflares and the Crab Nebula. In both cases the results are consistent with previous and complementary measurements. Preliminary work indicates that this new technique allows RHESSI to observe the integrated hard x-ray spectrum of weak extended sources on the quiet Sun.

  11. A graphical algebraic method for analysing shear zone displacements from observations on arbitrarily oriented outcrop surfaces

    NASA Astrophysics Data System (ADS)

    Grigull, Susanne; Little, Timothy A.

    2008-07-01

    We present a practical graphical-algebraic method that enables one to achieve the true displacement and shape of deformed geological markers in fault or shear zones as observed on arbitrarily oriented outcrop surfaces. We use as our natural example deformed quartz veins that have been sheared across brittle-ductile faults in the Southern Alps of New Zealand. The technique is based on the assumption that simple shear has dominated the shear zone formation. For input data we require the strikes and dips of the outcrop surfaces, the offset markers, and the shear zones as well as the pitch of the simple shear vector in the plane of the shear zone. The paper develops a set of algebraic and graphical operations that allow one to convert photographs of faulted or sheared planar markers observed on an arbitrary outcrop surface into an equivalent view that is coincident with the movement ( m) plane of the fault or shear zone. This view displays the true displacement of the offset marker and delineates its deformed shape as seen in a section that is parallel to the slip vector.

  12. Scalable Methods for Electronic Excitations and Optical Responses of Nanostructures: Mathematics to Algorithms to Observables

    SciTech Connect

    Carter, Emily A

    2013-02-02

    Kohn-Sham density functional theory (DFT) is a powerful, well-established tool for the study of condensed phase electronic structure. However, there are still a number of situations where its applicability is limited. The basic theme of our research is the development of first principles electronic structure approaches for condensed matter that goes beyond what can currently be done with standard implementations ofKohn-Sham DFT. Our efforts to this end have focused on two classes or' methods. The first addresses the well-lmown inability of DFT to handle strong, many-body electron correlation effects. Our approach is a DFT -based embedding theory, to treat localized features (e.g. impurity, adsorbate, vacancy, etc.) embedded in a periodic, metallic crystal. A description for the embedded region is provided by explicitly correlated, ab initio wave function methods. DFT, as a fo1n1ally ground state theory, does not give a good description of excited states; an additional feature of our approach is the ability to obtain excitations localized in this region. We apply our method to a first-principles study of the adsorption of a single magnetic Co ada tom on non-magnetic Cu( 111 ), a known Kondo system whose behavior is governed by strong electron correlation. ? The second class of methods that we are developing is an orbital-free density functional theory (OFDFT), which addresses the speed limitations ofKohn-Sham DFT. OFDFT is a powerful, O(N) scaling method for electronic structure calculations. Unlike Kohn-Sham DFT, OFDFT goes back to the original Hohenberg-Kohn idea of directly optimizing an energy functional which is an explicit functional of the density, without invoking an orbital description. This eliminates the need to manipulate orbitals, which leads to O(N{sup 3}) scaling in the Kahn-Sham approach. The speed of OFDFT allows direct electronic structure calculations on large systems on the order of thousands to tens of thousands of atoms, an expensive feat within Kohn-Sham. Due to our incomplete knowledge of the exact, universal energy density functional, this speedup comes at the cost of some accuracy with respect to Kohn-Sham methods. However, OFDFT has been shown to be remarkably accurate with respect to Kohn-Sham when used in the study of nearly-free-electron-like metals, e.g., AI, for which good density functionals have been derived. Examples of past applications of OFDFT include the prediction of properties of bulk crystals, surfaces, vacancies, vacancy clusters, nanoclusters, and dislocations, as well as OFDFT -based multiscale simulations of nanoindentation in AI and Al-Mg alloys.

  13. Patients’ Experience of Tuberculosis Treatment Using Directly Observed Treatment, Short-Course (DOTS): A Qualitative Study

    PubMed Central

    Behzadifar, Masoud; Mirzaei, Masoud; Behzadifar, Meysam; Keshavarzi, Abouzar; Behzadifar, Maryam; Saran, Maryam

    2015-01-01

    Background: Despite effective diagnosis and treatment, prevalence of tuberculosis (TB) is still growing. The directly observed treatment, short-course (DOTS) strategy to treat TB was introduced by the World Health Organization more than a decade ago. Little is known about patients’ experience of TB treatment, according to DOTS, in Iran. Objectives: This study aimed to understand the patients’ experience of tuberculosis treatment according to DOTS in Iran. Patients and Methods: This study is a qualitative study, using content analysis to examine patients’ experience of TB treatment and to understand their compliance during DOTS. In this study, a semi-structured interview with open questions was answered by 40 patients, who had a diagnosis of pulmonary and extrapulmonary tuberculosis, and improved during the course of their treatment. The method of sampling was purposive sample and the interview process lasted until data saturation. Results: Data analysis resulted in the extraction of six themes, which reflect the experiences of the study participants. The themes are: 1) individual factors; 2) change of the attitudes and beliefs of patients on TB treatment; 3) support terms of patients with tuberculosis; 4) the role of health care professionals; 5) social factors and 6) the financial burden. Conclusions: Successful completion of TB treatment requires an effective partnership between the patient and health care professionals, and a harmony between the cultural context, attitude of the patient, family support and health literacy. Future health policies should address these issues to improve patients’ adherence to DOTS. PMID:26023334

  14. Chromatographic methods in the study of autism.

    PubMed

    ?urawicz, Ewa; Ka?u?na-Czapli?ska, Joanna; Rynkowski, Jacek

    2013-10-01

    Research into biomarkers of autism is a new means of medical intervention in this disease. Chromatographic techniques, especially coupled with mass spectrometry, are widely used in determination of biomarkers and assessment of effectiveness of autism therapy owing to their sensitivity and selectivity. Among the chromatographic techniques gas chromatography and liquid chromatography, especially high-performance liquid chromatography, have found application in clinical trials. The high-performance liquid chromatography technique allows an analysis of liquid samples with a wide range of molecules, small and large, providing an opportunity to perform advanced assays within a short time frame. Gas chromatography with the appropriate preparation of samples (gaseous and liquid) and a selection of analysis conditions enables the separation of thermally stable, volatile and non-volatile organic substances in short runtimes. The chromatographic techniques that are currently used in metabolic studies in autism are designed to identify abnormalities in three areas: the metabolism of neurotransmitters, nutritional and metabolic status and manifestations of oxidative stress. This review presents a necessary theoretical introduction and examples of applications of chromatographic studies of disorder markers in autism. PMID:23605782

  15. Evaluating observational methods to quantify snow duration under diverse forest canopies

    NASA Astrophysics Data System (ADS)

    Dickerson-Lange, Susan E.; Lutz, James A.; Martin, Kael A.; Raleigh, Mark S.; Gersonde, Rolf; Lundquist, Jessica D.

    2015-02-01

    Forests cover almost 40% of the seasonally snow-covered regions in North America. However, operational snow networks are located primarily in forest clearings, and optical remote sensing cannot see through tree canopies to detect forest snowpack. Due to the complex influence of the forest on snowpack duration, ground observations in forests are essential. We therefore consider the effectiveness of different strategies to observe snow-covered area under forests. At our study location in the Pacific Northwest, we simultaneously deployed fiber-optic cable, stand-alone ground temperature sensors, and time-lapse digital cameras in three diverse forest treatments: control second-growth forest, thinned forest, and forest gaps (one tree height in diameter). We derived fractional snow-covered area and snow duration metrics from the colocated instruments to assess optimal spatial resolution and sampling configuration, and snow duration differences between forest treatments. The fiber-optic cable and the cameras indicated that mean snow duration was 8 days longer in the gap plots than in the control plots (p < 0.001). We conducted Monte Carlo experiments for observing mean snow duration in a 40 m forest plot, and found the 95% confidence interval was ±5 days for 10 m spacing between instruments and ±3 days for 6 m spacing. We further tested the representativeness of sampling one plot per treatment group by observing snow duration across replicated forest plots at the same elevation, and at a set of forest plots 250 m higher. Relative relationships between snow duration in the forest treatments are consistent between replicated plots, elevation, and two winters of data.

  16. Thermoacoustic CT of the breast: pilot study observations

    NASA Astrophysics Data System (ADS)

    Kruger, Robert A.; Kiser, William L., Jr.; Romilly, A. P.; Scmidt, Phyllis

    2001-06-01

    In order to assess the potential clinical utility of using thermoacoustic computer tomography (TCT) to image the breast, we conducted a retrospective pilot study of 78 patients. We recruited patients in three age groups (<40,40-50,>50 years). The study population was further segregated into normal and suspicious based on the results of the previous x-ray mammography and ultrasound. Image quality was evaluated qualitatively by consensus of two trained mammographers using a 4-point scale. The appearance of normal anatomy, cysts, benign disease and cancer was noted. Patients were also asked to rate the comfort of the TCT exam and to indicate a personal preference for x-ray mammography or TCT. Analysis of the data indicated that TCT image quality was dependent upon both patient age and breast density, improving with both increasing breast density and decreasing patient age. Fibrocystic disease was well seen, cysts appearing as areas of low RF absorption. Fibroadenomas did not demonstrate contrast enhancement with the exception of one patient with associated atypical hyperplasia. Cancer displayed higher RF absorption than surrounding tissues in 4/7 patients in whom cancer was confirmed, including one patient with a 7-mm ductal carcinoma in situ (DCIS).

  17. An observational study of co-rumination in adolescent friendships.

    PubMed

    Rose, Amanda J; Schwartz-Mette, Rebecca A; Glick, Gary C; Smith, Rhiannon L; Luebbe, Aaron M

    2014-09-01

    Co-rumination is a dyadic process between relationship partners that refers to excessively discussing problems, rehashing problems, speculating about problems, mutual encouragement of problem talk, and dwelling on negative affect. Although studies have addressed youths' tendency to co-ruminate, little is known about the nature of co-ruminative conversations. The primary goal of the present study (N = 314 adolescent friend dyads) was to identify microsocial processes that sustain and reinforce problem talk among adolescent co-ruminating friends. Results indicated that co-rumination was characterized by friends responding to each other's statements about problems with engaged statements (e.g., questions, supportive statements) that elicited even more problem talk. Results also indicated that some aspects of co-rumination (i.e., extensively talking about problems, rehashing problems, speculating about problems, and mutual encouragement of problem talk) were associated with positive friendship adjustment, whereas other aspects (i.e., dwelling on negative affect) were associated with internalizing problems. The present research highlights the utility of attending to microsocial processes in friends' conversations and has implications for intervention. PMID:25069053

  18. An observational and theoretical study of Colorado lee cyclogenesis

    NASA Technical Reports Server (NTRS)

    Clark, John H. E.

    1990-01-01

    A cyclogenesis event that occurred over Colorado in early March of 1981 is the focus of this study. Two features that seemed to play a role in storm initiation were a traveling upper troposphere disturbance associated with an undulation on the subtropical front and a warm-cored shallow surface trough that was guided along the eastern slope of the Rockies from Canada to Colorado. The arrival of the latter feature initiated a sudden shift of the surface flow from upslope to downslope on the eastern side of the continental divide. A time-dependent quasi-geostrophic model was used to study the interaction of the traveling short wave and a broad topographic surface ridge in the presence of a baroclinic mainly westerly background flow. Westerly and easterly background surface winds were used to determine whether the surface trough arrival had any influence on the vigor of lee cyclogenesis initiated by the upper troposphere short-wave trough. With surface westerlies rapid cyclogenesis occurred, while with surface easterlies little cyclogenesis was found to the east of the Rockies. Thus, the shallow surface trough's arrival seemed to be crucial to storm initiation. These findings were based on a linear model. It is shown, however, that the height of the Rockies necessitates the inclusion of finite amplitude effects associated with the lower boundary into the model.

  19. An observational study to detect leptospirosis in Mumbai, India, 2000

    PubMed Central

    Karande, S; Bhatt, M; Kelkar, A; Kulkarni, M; De, A; Varaiya, A

    2003-01-01

    Background: Leptospirosis is relatively uncommon in children. Following torrential rains and flooding an outbreak of leptospirosis was suspected in Mumbai. Aims: To investigate the possibility of an outbreak of leptospirosis and describe the clinical illness. Methods: From 24 July to 14 September 2000, children with a history of abrupt onset of high fever (>39°C), who presented to our hospital, were admitted and tested serologically for anti-Leptospira antibodies by a quantitative enzyme linked immunosorbent assay (ELISA) test. An IgM titre of more than 20U/ml confirmed the diagnosis of leptospirosis. Clinical features in the confirmed leptospirosis and leptospirosis negative groups were analysed. Results: Of 53 children screened, 18 (34%) had leptospirosis. In all 18, the disease was anicteric and responded well to intravenous penicillin. Four clinical features present at the time of admission were significantly associated with leptospirosis: a history of contact with flood water (18/18 v 16/35), conjunctival suffusion (5/18 v 1/35), abdominal pain (9/18 v 5/35), and skin rash (5/18 v 1/35). As the number of these four features concomitantly present increased, the chances of the child having leptospirosis also increased significantly. A history of contact with flood water had a sensitivity of 100%, and the presence of conjunctival suffusion, abdominal pain, and skin rash had a specificity of 97%, 86%, and 97%, respectively, for identifying children with leptospirosis. Conclusion: Leptospirosis should be suspected in febrile children with contact with flood water. PMID:14670771

  20. Primary reperfusion in acute right ventricular infarction: An observational study

    PubMed Central

    Lupi-Herrera, Eulo; González-Pacheco, Héctor; Juárez-Herrera, Úrsulo; Espinola-Zavaleta, Nilda; Chuquiure-Valenzuela, Eduardo; Villavicencio-Fernández, Ramón; Peña-Duque, Marco Antonio; Ban-Hayashi, Ernesto; Férez-Santander, Sergio

    2014-01-01

    AIM: To investigate the impact of primary reperfusion therapy (RT) on early and late mortality in acute right ventricular infarction (RVI). METHODS: RVI patients (n = 679) were prospectively classified as without right ventricular failure (RVF) (class A, n = 425, 64%), with RVF (class B, n = 158, 24%) or with cardiogenic shock (CS) (class C, n = 96, 12%). Of the 679 patients, 148 (21.7%) were considered to be eligible for thrombolytic therapy (TT) and 351 (51.6%) for primary percutaneous coronary intervention (PPCI). TIMI 3-flow by TT was achieved for A, B and C RVI class in 65%, 64% and 0%, respectively and with PPCI in 93%, 91% and 87%, respectively. RESULTS: For class A without RT, the mortality rate was 7.9%, with TT was reduced to 4.4% (P < 0.01) and with PPCI to 3.2% (P < 0.01). Considering TT vs PPCI, PPCI was superior (P < 0.05). For class B without RT the mortality was 27%, decreased to 13% with TT (P < 0.01) and to 8.3% with PPCI (P < 0.01). In a TT and PPCI comparison, PPCI was superior (P < 0.01). For class C without RT the in-hospital mortality was 80%, with TT was 100% and with PPCI, the rate decreased to 44% (P < 0.01). At 8 years, the mortality rate without RT for class A was 32%, for class B was 48% and for class C was 85%. When PPCI was successful, the long-term mortality was lower than previously reported for the 3 RVI classes (A: 21%, B: 38%, C: 70%; P < 0.001). CONCLUSION: PPCI is superior to TT and reduces short/long-term mortality for all RVI categories. RVI CS patients should be encouraged to undergo PPCI at a specialized center. PMID:24527184

  1. Variability of linezolid concentrations after standard dosing in critically ill patients: a prospective observational study

    PubMed Central

    2014-01-01

    Introduction Severe infections in intensive care patients show high morbidity and mortality rates. Linezolid is an antimicrobial drug frequently used in critically ill patients. Recent data indicates that there might be high variability of linezolid serum concentrations in intensive care patients receiving standard doses. This study was aimed to evaluate whether standard dosing of linezolid leads to therapeutic serum concentrations in critically ill patients. Methods In this prospective observational study, 30 critically ill adult patients with suspected infections received standard dosing of 600 mg linezolid intravenously twice a day. Over 4 days, multiple serum samples were obtained from each patient, in order to determine the linezolid concentrations by liquid chromatography tandem mass spectrometry. Results A high variability of serum linezolid concentrations was observed (range of area under the linezolid concentration time curve over 24 hours (AUC24) 50.1 to 453.9 mg/L, median 143.3 mg*h/L; range of trough concentrations (Cmin)?observed for 63% and 50% of the patients, respectively. Finally, potentially toxic levels (defined as AUC24?>?400 mg*h/L and Cmin?>?10 mg/L) were observed for 7 of the patients. Conclusions A high variability of linezolid serum concentrations with a substantial percentage of potentially subtherapeutic levels was observed in intensive care patients. The findings suggest that therapeutic drug monitoring of linezolid might be helpful for adequate dosing of linezolid in critically ill patients. Trial registration Clinicaltrials.gov NCT01793012. Registered 24 January 2013. PMID:25011656

  2. A study of linear programming and methods for programming the simplex method

    E-print Network

    Watson, Warren Wallace

    1960-01-01

    A STUDY OF LINEAR PROGRAMMING AND METHODS FOR PROGRAMMING THE SIMPLEX METHOD A Thesis By Warren W. Watson Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 19 60 (month) (year) Major Subject Mathematics A STUDY OF LINEAR PROGRAMMING AND METHODS FOR PROGRAMMING THE SIMPLEX METHOD A Thesis By Warren W. Watson Approved as to style and content by: (Chairman of mmit...

  3. Propensity Score Methods for Analyzing Observational Data Like Randomized Experiments: Challenges and Solutions for Rare Outcomes and Exposures.

    PubMed

    Ross, Michelle E; Kreider, Amanda R; Huang, Yuan-Shung; Matone, Meredith; Rubin, David M; Localio, A Russell

    2015-06-15

    Randomized controlled trials are the "gold standard" for estimating the causal effects of treatments. However, it is often not feasible to conduct such a trial because of ethical concerns or budgetary constraints. We expand upon an approach to the analysis of observational data sets that mimics a sequence of randomized studies by implementing propensity score models within each trial to achieve covariate balance, using weighting and matching. The methods are illustrated using data from a safety study of the relationship between second-generation antipsychotics and type 2 diabetes (outcome) in Medicaid-insured children aged 10-18 years across the United States from 2003 to 2007. Challenges in this data set include a rare outcome, a rare exposure, substantial and important differences between exposure groups, and a very large sample size. PMID:25995287

  4. Statistical analysis of observational study of the influence of radon and other risk factors on lung cancer incidence.

    PubMed

    Zhukovsky, Michael; Varaksin, Anatole; Pakholkina, Olga

    2014-07-01

    An observational study is a type of epidemiological study when the researcher observes the situation but is not able to change the conditions of the experiment. The statistical analysis of the observational study of the population of Lermontov city (North Caucasus) was conducted. In the initial group, there were 121 people with lung cancer diagnosis and 196 people of the control group. Statistical analysis was performed only for men (95 cases and 76 controls). The use of logistic regression with correction on age gives the value of odds ratio 1.95 (0.87÷4.37; 90% CI) per 100 working levels per month of combined (occupational and domestic) radon exposure. It was demonstrated that chronic lung diseases are an additional risk factor for uranium miners but it is not a significant risk factor for general population. Thus, the possibility of obtaining statistically reliable results in the observational studies when using the correct methods of analysis is demonstrated. PMID:24714108

  5. Transesophageal defibrillation: animal studies and preliminary clinical observations.

    PubMed

    Cohen, T J; Chin, M C; Oliver, D G; Scheinman, M M; Griffin, J C

    1993-06-01

    Ventricular fibrillation (VF) that fails to respond to transthoracic defibrillation leaves the clinician with few alternatives. The purpose of this study was to develop a technique of rescue defibrillation by use of transesophageal electrodes. Fourteen anesthetized dogs (20-30 kg) were investigated in this study. Two electrodes (300 mm2) were mounted 8 cm apart on an esophageal probe and inserted approximately 40 cm from the mouth. VF was induced using AC current delivered to the myocardium. Defibrillation was then performed between the distal electrode (anode) and anterior skin patch (cathode). After 15 seconds of induced VF, transesophageal and transthoracic defibrillation thresholds (DFTs) were determined in random order. The esophageal DFT (90 +/- 15 joules) tended to be lower than the transthoracic DFT (115 +/- 35 joules), though this difference was not statistically significant. One dog could not be defibrillated by transthoracic defibrillation but responded to transesophageal defibrillation. Esophageal electrodes were also useful for arrhythmia discrimination and ventricular pacing (pacing threshold of 38 +/- 5 mA at a pulse duration of 2.5 msec). Following transesophageal DFT determination, in ten dogs (total energy of 600 +/- 150 joules), acute esophageal histopathology demonstrated mild to severe focal injury to the mucosa and/or muscular layers. However, esophagi in four chronic dogs (total energy of 470 +/- 110 joules) showed no gross evidence of mucosal damage, perforation, or stricture 4 weeks following defibrillation. Histopathology showed only focal myocyte atrophy and repair. As a last resort, transesophageal defibrillation was performed in the emergency room on four patients with out-of-hospital refractory VF who failed > 6 high energy transthoracic shocks.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7686658

  6. Lung cancer detection with digital chest tomosynthesis: first round results from the SOS observational study

    PubMed Central

    Viti, Andrea; Tavella, Chiara; Priotto, Roberto; Ghirardo, Donatella; Grosso, Maurizio; Terzi, Alberto

    2015-01-01

    Objective Baseline results of the Studio OSservazionale (SOS), observational study, a single-arm observational study of digital chest tomosynthesis for lung cancer detection in an at-risk population demonstrated a detection rate of lung cancer comparable to that of studies that used low dose CT scan (LDCT). We present the results of the first round. Methods Totally 1,703 out of 1,843 (92%) subjects who had a baseline digital chest tomosynthesis underwent a first round reevaluation after 1 year. Results At first round chest digital tomosynthesis, 13 (0.7%) subjects had an indeterminate nodule larger than 5 mm and underwent low-dose CT scan for nodule confirmation. PET/CT study was obtained in 10 (0.5%) subjects and 2 subjects had a low-dose CT follow up. Surgery, either video-assisted thoracoscopic or open surgery for indeterminate pulmonary nodules was performed in 10 (0.2%) subjects. A lung cancer was diagnosed and resected in five patients. The lung cancer detection rate at first round was 0.3% (5/1,703). Conclusions The detection rate of lung cancer at first round for tomosynthesis is comparable to rates reported for CT. In addition, results of first round digital chest tomosynthesis confirm chest tomosynthesis as a possible first-line lung cancer-screening tool. PMID:25992366

  7. Generalizability and Decision Studies to Inform Observational and Experimental Research in Classroom Settings

    ERIC Educational Resources Information Center

    Bottema-Beutel, Kristen; Lloyd, Blair; Carter, Erik W.; Asmus, Jennifer M.

    2014-01-01

    Attaining reliable estimates of observational measures can be challenging in school and classroom settings, as behavior can be influenced by multiple contextual factors. Generalizability (G) studies can enable researchers to estimate the reliability of observational data, and decision (D) studies can inform how many observation sessions are…

  8. A simulation study of methods for constructing confidence intervals for bioaccumulation factors.

    PubMed

    Wheeler, Matthew W; Bailer, A John

    2003-04-01

    Toxicokinetics describe the time course of xenobiotics in an exposed organism. The steady state concentration of the xenobiotic is a characteristic of frequent concern, often summarized in terms of bioaccumulation factors (BAFs). Two experimental protocols are commonly used when estimating BAFs: a continuous exposure experiment and a start-stop exposure experiment. Nonlinear regression is then used for estimating components of the BAF. A variety of methods are available for constructing confidence intervals (CI) for the BAF, including the delta method and Fieller's method. The properties of these CI methods are explored through a simulation study. In particular, the coverage properties of the two CI methods along with their interval widths are examined for a variety of time-course patterns, error distributions, experimental protocols, and sampling designs. Fieller's method is observed to exceed nominal coverage probabilities for all conditions considered (the coverage probability being the probability that a confidence interval contains a parameter it estimates over repeated experiments). The delta method exhibited observed coverage probabilities lower than nominally specified for a number of conditions. For sampling designs in which more of the sampling times are prior to steady state or the stop exposure time, the delta method is observed to provide nominal coverage probabilities with interval widths much narrower than observed with the Fieller's method. Thus, the delta method is preferable when the above sampling time condition is met; however, in all other cases, Fieller's method should be used. PMID:12685730

  9. Depression and Oxidative Stress: Results From a Meta-Analysis of Observational Studies

    PubMed Central

    Palta, Priya; Samuel, Laura J.; Miller, Edgar R.; Szanton, Sarah L.

    2014-01-01

    Objective To perform a systematic review and meta-analysis that quantitatively tests and summarizes the hypothesis that depression results in elevated oxidative stress and lower antioxidant levels. Methods We performed a meta-analysis of studies that reported an association between depression and oxidative stress and/or antioxidant status markers. PubMed and EMBASE databases were searched for articles published from January 1980 through December 2012. A random-effects model, weighted by inverse variance, was performed to pool standard deviation (Cohen’s d) effect size estimates across studies for oxidative stress and antioxidant status measures, separately. Results Twenty-three studies with 4980 participants were included in the meta-analysis. Depression was most commonly measured using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. A Cohen’s d effect size of 0.55 (95% confidence interval = 0.47–0.63) was found for the association between depression and oxidative stress, indicating a roughly 0.55 of 1-standard-deviation increase in oxidative stress among individuals with depression compared with those without depression. The results of the studies displayed significant heterogeneity (I2 = 80.0%, p < .001). A statistically significant effect was also observed for the association between depression and antioxidant status markers (Cohen’s d = ?0.24, 95% confidence interval = ?0.33 to ?0.15). Conclusions This meta-analysis observed an association between depression and oxidative stress and antioxidant status across many different studies. Differences in measures of depression and markers of oxidative stress and antioxidant status markers could account for the observed heterogeneity. These findings suggest that well-established associations between depression and poor heath outcomes may be mediated by high oxidative stress. PMID:24336428

  10. Central venous port-related infection in patients with malignant tumors: An observational study

    PubMed Central

    Sone, Miyuki; Ehara, Shigeru; Kato, Kenichi; Suzuki, Michiko; Tanaka, Ryoichi; Suwabe, Akira; Itabashi, Tetsuya; Masahiro, Kashiwaba

    2012-01-01

    Purpose We evaluated the characteristics of central venous port (CVP)-related infection with microbiological assessments in patients with malignant tumors. Materials and methods In a prospective setting, patients with CVP for the treatment of malignant tumors were enrolled in this study. The incidence of CVP-related infection during three months was determined. Microbiological surveillance from skin swab was performed before and after CVP placement. Results Fifty-nine patients were enrolled in this study, and 60 CVPs were implanted. Thirty-six (61%) patients had head and neck malignancies. Access route was subclavian vein in 43 (71.7%) CVPs and forearm vein in 17 (28.3%). CVP-related infection was observed in three (5.1%) patients: port-pocket infection in one and probable CVP-related infection in two patients, respectively. No definitive CVP-related bloodstream infection was observed. Before the placement of CVP, colonization at the insertion site was observed in ten subclavian CVP patients, while no colonization was observed in the forearm CVP patients. At 1 and 4 weeks, detection rates of colonization were also higher in subclavian CVP patients. No definitive relationship was demonstrated between skin colonization and clinical development of CVP-related infection. Conclusion The rate of CVP-related infection in this prospective evaluation in patients with malignant tumors was comparable to previous studies. Colonization of the skin was more prominent in the subclavian site than in the forearm site. Although skin colonization was not proven to be a risk factor of infection, these results may draw attention to the adequate maintenance of CVP. (Trial registration: UMIN000003664). PMID:22376242

  11. Longitudinal analyses of early lesions by fluorescence: an observational study.

    PubMed

    Ferreira Zandoná, A; Ando, M; Gomez, G F; Garcia-Corretjer, M; Eckert, G J; Santiago, E; Katz, B P; Zero, D T

    2013-07-01

    Previous caries experience correlates to future caries risk; thus, early identification of lesions has importance for risk assessment and management. In this study, we aimed to determine if Quantitative Light-induced Fluorescence (QLF) parameters--area (A [mm(2)]), fluorescence loss (F [%]), and Q [% × mm(2)]--obtained by image analyses can predict lesion progression. We secured consent from 565 children (from 5-13 years old) and their parents/guardians and examined them at baseline and regular intervals over 48 months according to the International Caries Detection Assessment System (ICDAS), yearly radiographs, and QLF. QLF images from surfaces with ICDAS 0/1/2/3/4 at baseline that progressed (N = 2,191) to cavitation (ICDAS 5/6) or fillings and surfaces that did not progress to cavitation/fillings (N = 4,141) were analyzed independently for A, F, and Q. Linear mixed-effects models were used to compare means and slopes (changes over time) between surfaces that progressed and those that did not. QLF A, F, and Q increased at a faster rate for surfaces that progressed than for surfaces that did not progress (p = .0001), regardless of type of surface or baseline ICDAS score. AUC for ICDAS ranged from 0.65 to 0.80, but adding QLF information improved AUC (0.82-0.87, p < .0005). We concluded that faster changes in QLF variables can indicate lesion progression toward cavitation and be more clinically relevant than actual QLF values. PMID:23690351

  12. Heavy metals and neurodegenerative diseases: an observational study.

    PubMed

    Giacoppo, Sabrina; Galuppo, Maria; Calabrò, Rocco Salvatore; D'Aleo, Giangaetano; Marra, Angela; Sessa, Edoardo; Bua, Daniel Giuseppe; Potortì, Angela Giorgia; Dugo, Giacomo; Bramanti, Placido; Mazzon, Emanuela

    2014-11-01

    In this study, we evaluated the levels of some of the most investigated metals (Cu, Se, Zn, Pb, and Hg) in the blood of patients affected by the most common chronic neurodegenerative diseases like Alzheimer's disease (AD) and multiple sclerosis (MS), in order to better clarify their involvement. For the first time, we investigated a Sicilian population living in an area exposed to a potentially contaminated environment from dust and fumes of volcano Etna and consumer of a considerable quantity of fish in their diet, so that this represents a good cohort to demonstrate a possible link between metals levels and development of neurodegenerative disorders. More specifically, 15 patients affected by AD, 41 patients affected by MS, 23 healthy controls, and 10 healthy elderly controls were recruited and subjected to a venous blood sampling. Quantification of heavy metals was performed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This technique has allowed us to establish that there is a concomitance of heavy metal unbalance associated with AD more than in other neurodegenerative pathologies, such as MS. Also, we can assess that the concentration of these elements is independent from the diet, especially from occasional or habitual consumption of fruits and vegetables, prevalence in the diet of meat or fish, possible exposure to contaminated environment due both to the occupation and place of residence. PMID:25107328

  13. [Observation and study on atmospheric VOCs in Changsha city].

    PubMed

    Liu, Quan; Wang, Yue-Si; Wu, Fang-Kun; Sun, Jie

    2011-12-01

    Volatile organic compounds (VOCs) are one of the key precursors of atmospheric ozone (O3), which also contribute to the production of SOA. During 2008, VOCs were measured near Changsha City. Weekly integrated canister samples were collected and analyzed in the morning and afternoon of each Tuesday. Simultaneously, concentration, potential ozone production and sources of VOCs in the atmosphere of Changsha were studied. The results indicated that the total VOCs species had higher concentrations in the morning (38.4 x 10(-9)), and lower in the afternoon (22.7 x 10(-9)), where the concentration of halo carbon was the highest, and alkanes, aromatics and alkenes came next. The m/p-xylene had the highest OH reactivity concentration (10.71 x 10(-9) C), 1,2,4-trimethylbenzene (6.04 x 10(-9) C) and 1,3,5-trimethylbenzene (2.23 x 10(-9) C) came next. Aromatics (66%) had the most significant contribution to the production of O3 in the atmospheric VOCs of Changsha, and alkenes (26%) and alkanes (8%) came next. The highest concentrations of propane and isopentane indicated vehicular exhaust and liquefied petroleum gas (LPG) appear to be the main source of VOCs in Changsha City. Benzene/toluene ratio was higher than 0.5 which was close to 0.8, showing solvent volatilization was also a main source of VOCs. PMID:22468515

  14. Identifying Conditions That Support Causal Inference in Observational Studies in Education: Empirical Evidence from within Study Comparisons

    ERIC Educational Resources Information Center

    Hallberg, Kelly

    2013-01-01

    This dissertation is a collection of three papers that employ empirical within study comparisons (WSCs) to identify conditions that support causal inference in observational studies. WSC studies empirically estimate the extent to which a given observational study reproduces the result of a randomized clinical trial (RCT) when both share the same…

  15. Reliability of Pubertal Self Assessment Method: An Iranian Study

    PubMed Central

    Rabbani, Ali; Noorian, Shahab; Fallah, Javad S.; Setoudeh, Arya; Sayarifard, Fatemeh; Abbasi, Farzaneh

    2013-01-01

    Objective This investigation aims to evaluate the validity of a Persian Tanner Stages Self-Assessment Questionnaire. Methods In this cross sectional study, 190 male students aged 8-16 years selected from three layers of different regions of Tehran (North, Central and South) were enrolled. A Persian questionnaire illustrated with Tanner stages of puberty (genital development and pubic hair distribution) was prepared. Children were asked to select the illustration that best described their pubertal development. Tanner status of the children was also estimated by an independent physician using physical examination. The degree of agreement between subjects’ judgments with assessments made by the rater was compared through the calculation of the weighted kappa statistic coefficient. Findings We found a substantial agreement between self-assessment of pubertal development made by the children and doctor's assessment of genital development (kappa=0.63, P<0.0001) and also the pubic hair distribution (kappa= 0.74, P<0.0001). Although a large proportion of subjects in G4 (89.2%) and G5 (85.7%) were capable of accurately or almost accurately identifying their own Tanner sexual stages, some degree of disagreement was observed in G3 Tanner stage (%46.9). Conclusion Self-assessment of puberty should be used very cautiously and may not be a substitute method for routine evaluation of pubertal state especially for early and mid pubertal groups. PMID:23795257

  16. Ethnographic Methods to Study Context: An Illustration* Michael Evans,

    E-print Network

    Bogaerts, Steven

    Ethnographic Methods to Study Context: An Illustration* Michael Evans, 1 David Leake, 2 Donald F for developing such systems, and ethnographic studies can play an important role in shaping system design. We study (Evans 2004). 2 Design of the Study Ethnographic studies can be conducted with a number

  17. A comparison of methods for smoothing and gap filling time series of remote sensing observations - application to MODIS LAI products

    NASA Astrophysics Data System (ADS)

    Kandasamy, S.; Baret, F.; Verger, A.; Neveux, P.; Weiss, M.

    2013-06-01

    Moderate resolution satellite sensors including MODIS (Moderate Resolution Imaging Spectroradiometer) already provide more than 10 yr of observations well suited to describe and understand the dynamics of earth's surface. However, these time series are associated with significant uncertainties and incomplete because of cloud cover. This study compares eight methods designed to improve the continuity by filling gaps and consistency by smoothing the time course. It includes methods exploiting the time series as a whole (iterative caterpillar singular spectrum analysis (ICSSA), empirical mode decomposition (EMD), low pass filtering (LPF) and Whittaker smoother (Whit)) as well as methods working on limited temporal windows of a few weeks to few months (adaptive Savitzky-Golay filter (SGF), temporal smoothing and gap filling (TSGF), and asymmetric Gaussian function (AGF)), in addition to the simple climatological LAI yearly profile (Clim). Methods were applied to the MODIS leaf area index product for the period 2000-2008 and over 25 sites showed a large range of seasonal patterns. Performances were discussed with emphasis on the balance achieved by each method between accuracy and roughness depending on the fraction of missing observations and the length of the gaps. Results demonstrate that the EMD, LPF and AGF methods were failing because of a significant fraction of gaps (more than 20%), while ICSSA, Whit and SGF were always providing estimates for dates with missing data. TSGF (Clim) was able to fill more than 50% of the gaps for sites with more than 60% (80%) fraction of gaps. However, investigation of the accuracy of the reconstructed values shows that it degrades rapidly for sites with more than 20% missing data, particularly for ICSSA, Whit and SGF. In these conditions, TSGF provides the best performances that are significantly better than the simple Clim for gaps shorter than about 100 days. The roughness of the reconstructed temporal profiles shows large differences between the various methods, with a decrease of the roughness with the fraction of missing data, except for ICSSA. TSGF provides the smoothest temporal profiles for sites with a % gap > 30%. Conversely, ICSSA, LPF, Whit, AGF and Clim provide smoother profiles than TSGF for sites with a % gap < 30%. Impact of the accuracy and smoothness of the reconstructed time series were evaluated on the timing of phenological stages. The dates of start, maximum and end of the season are estimated with an accuracy of about 10 days for the sites with a % gap < 10% and increases rapidly with the % gap. TSGF provides more accurate estimates of phenological timing up to a % gap < 60%.

  18. A comparison of methods for smoothing and gap filling time series of remote sensing observations: application to MODIS LAI products

    NASA Astrophysics Data System (ADS)

    Kandasamy, S.; Baret, F.; Verger, A.; Neveux, P.; Weiss, M.

    2012-12-01

    Moderate resolution satellite sensors including MODIS already provide more than 10 yr of observations well suited to describe and understand the dynamics of the Earth surface. However, these time series are incomplete because of cloud cover and associated with significant uncertainties. This study compares eight methods designed to improve the continuity by filling gaps and the consistency by smoothing the time course. It includes methods exploiting the time series as a whole (Iterative caterpillar singular spectrum analysis (ICSSA), empirical mode decomposition (EMD), low pass filtering (LPF) and Whittaker smoother (Whit)) as well as methods working on limited temporal windows of few weeks to few months (Adaptive Savitzky-Golay filter (SGF), temporal smoothing and gap filling (TSGF) and asymmetric Gaussian function (AGF)) in addition to the simple climatological LAI yearly profile (Clim). Methods were applied to MODIS leaf area index product for the period 2000-2008 over 25 sites showing a large range of seasonal patterns. Performances were discussed with emphasis on the balance achieved by each method between accuracy and roughness depending on the fraction of missing observations and the length of the gaps. Results demonstrate that EMD, LPF and AGF methods were failing in case of significant fraction of gaps (%Gap > 20%), while ICSSA, Whit and SGF were always providing estimates for dates with missing data. TSGF (respectively Clim) was able to fill more than 50% of the gaps for sites with more than 60% (resp. 80%) fraction of gaps. However, investigation of the accuracy of the reconstructed values shows that it degrades rapidly for sites with more than 20% missing data, particularly for ICSSA, Whit and SGF. In these conditions, TSGF provides the best performances significantly better than the simple Clim for gaps shorter than about 100 days. The roughness of the reconstructed temporal profiles shows large differences between the several methods, with a decrease of the roughness with the fraction of missing data, except for ICSSA. TSGF provides the smoothest temporal profiles for sites with %Gap > 30%. Conversely, ICSSA, LPF, Whit, AGF and Clim provide smoother profiles than TSGF for sites with %Gap < 30%. Impact of the accuracy and smoothness of the reconstructed time series were evaluated on the timing of phenological stages. The dates of start, maximum and end of the season are estimated with an accuracy of about 10 days for the sites with %Gap < 10% and increases rapidly with %Gap. TSGF provides the more accurate estimates of phenological timing up to %Gap < 60%.

  19. Exploring the mealtime experience in residential care settings for older people: an observational study.

    PubMed

    Barnes, Sarah; Wasielewska, Anna; Raiswell, Christine; Drummond, Barbara

    2013-07-01

    Improving the mealtime experience in residential care can be a major facilitator in improving care, well-being and QoL. Evidence suggests that, despite guidance on the subject of food, nutrition and hydration, there are still concerns. Although there is a range of methods to research and assess the quality of food provision, there is a challenge in capturing the experiences of those residents who are unable or unwilling to describe their feelings and experiences because of frailty, impaired communication or other vulnerability. The aim of this exploratory study was to capture and describe individual residents' mealtime experience. In spring 2011, a small-scale, observational study was carried out in seven dining settings in four residential care homes in Manchester. An adapted dementia care mapping tool was used alongside field notes. Observations showed two major differences in the way the mealtimes were organised: 'pre-plated' and 'family-style' (where either bowls of food are placed in the centre of the table or food is served directly from a hotplate by a chef). These two styles of service are discussed in relation to the emerging themes of 'task versus resident-centred mealtimes', 'fostering resident independence' and 'levels of interaction'. Although improving mealtimes alone is not enough to improve quality of life in care homes, findings showed that relatively small changes to mealtime delivery can potentially have an impact on resident well-being in these homes. Observation is a useful method of engaging residents in care settings for older people who may not otherwise be able to take part in research. PMID:23638872

  20. A performance study of the iterative ADI-FDTD method

    Microsoft Academic Search

    Shumin Wang; J. Chen

    2005-01-01

    The performance of the iterative alternating-direction implicit finite-difference time-domain (ADI-FDTD) method is studied. By interpreting the ADI-FDTD method as an iterative solver for the Crank-Nicolson scheme, we present analytical results of its convergence rate. Numerical examples further to demonstrate the performance of different variants of the iterative ADI-FDTD method.

  1. EXPOSURE ASSESSMENT METHODS DEVELOPMENT PILOTS FOR THE NATIONAL CHILDREN'S STUDY

    EPA Science Inventory

    Accurate exposure classification tools are needed to link exposure with health effects. EPA began methods development pilot studies in 2000 to address general questions about exposures and outcome measures. Selected pilot studies are highlighted in this poster. The ?Literature Re...

  2. The Efficacy of Influenza Vaccination in Healthcare Workers in a Tropical Setting: A Prospective Investigator Blinded Observational Study

    Microsoft Academic Search

    Si Wei Kheok; Chia Yin Chong; Grace McCarthy; Wai Yee Lim; Khean Teik Goh; Lubna Razak; Paul Ananth Tambyah

    Introduction: Influenza vaccine has been shown to be highly effective in temperate regions with well-defined seasonal influenza. Healthcare workers (HCWs) are advised to receive regular influenza vaccination to protect themselves and their patients. However, there are limited data on the efficacy of influenza vaccine in HCWs in the tropics. Materials and Methods: In this observational, investigator blinded cohort study, bi-monthly

  3. Dietary Patterns Predict Subsequent Coronary Heart Disease Risk In Postmenopausal Women : The Women’s Health Initiative Observational Cohort Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Evidence suggests that dietary patterns predispose to the development of coronary heart disease (CHD). The relationship between dietary patterns and CHD risk was assessed in postmenopausal women participating in the Women’s Health Initiative Observational Study (WHI-OS). Methods: Case-co...

  4. Does delay in diagnosing colorectal cancer in symptomatic patients affect tumor stage and survival? A population-based observational study

    Microsoft Academic Search

    Jochim S Terhaar sive Droste; Frank A Oort; René WM van der Hulst; Veerle MH Coupé; Mike E Craanen; Gerrit A Meijer; Linde M Morsink; Otto Visser; Roy LJ van Wanrooij; Chris JJ Mulder

    2010-01-01

    BACKGROUND: Diagnosing colorectal cancer (CRC) at an early stage improves survival. To what extent any delay affects outcome once patients are symptomatic is still unclear. Our objectives were to evaluate the association between diagnostic delay and survival in symptomatic patients with early stage CRC and late stage CRC. METHODS: Prospective population-based observational study evaluating daily clinical practice in Northern Holland.

  5. An Assessment of AKIN Criteria for Hospital-Acquired Acute Kidney Injury: A Prospective Observational Cohort Study

    Microsoft Academic Search

    Soon Hyo Kwon; Hyunjin Noh; Jin Seok Jeon; Yongbae Kim; Dong Cheol Han

    2010-01-01

    Background and Aims: The Acute Kidney Injury Network (AKIN) criteria assert a new definition for acute kidney injury (AKI). We investigated the incidence of hospital-acquired AKI, along with the clinical characteristics and outcomes in hospitalized patients according to AKIN stage. Methods: We performed a prospective, observational, single-center study. We monitored serum creatinine everyday for all patients using a hospital data

  6. Development of observation method for hydrothermal flows with acoustic video camera

    NASA Astrophysics Data System (ADS)

    Mochizuki, M.; Asada, A.; Kinoshita, M.; Tamura, H.; Tamaki, K.

    2011-12-01

    DIDSON (Dual-Frequency IDentification SONar) is acoustic lens-based sonar. It has sufficiently high resolution and rapid refresh rate that it can substitute for optical system in turbid or dark water where optical systems fail. Institute of Industrial Science, University of Tokyo (IIS) has understood DIDSON's superior performance and tried to develop a new observation method based on DIDSON for hydrothermal discharging from seafloor vent. We expected DIDSON to reveal whole image of hydrothermal plume as well as detail inside the plume. In October 2009, we conducted seafloor reconnaissance using a manned deep-sea submersible Shinkai6500 in Central Indian Ridge 18-20deg.S, where hydrothermal plume signatures were previously perceived. DIDSON was equipped on the top of Shinkai6500 in order to get acoustic video images of hydrothermal plumes. The acoustic video images of the hydrothermal plumes had been captured in three of seven dives. These are only a few acoustic video images of the hydrothermal plumes. We could identify shadings inside the acoustic video images of the hydrothermal plumes. Silhouettes of the hydrothermal plumes varied from second to second, and the shadings inside them varied their shapes, too. These variations corresponded to internal structures and flows of the plumes. We are analyzing the acoustic video images in order to deduce information of their internal structures and flows in plumes. On the other hand, we are preparing a tank experiment so that we will have acoustic video images of water flow under the control of flow rate. The purpose of the experiment is to understand relation between flow rate and acoustic video image quantitatively. Results from this experiment will support the aforementioned image analysis of the hydrothermal plume data from Central Indian Ridge. We will report the overview of the image analysis and the tank experiments, and discuss possibility of DIDSON as an observation tool for seafloor hydrothermal activity.

  7. Evaluating Observational Methods to Quantify Snow Duration under Diverse Forest Canopies

    NASA Astrophysics Data System (ADS)

    Dickerson-Lange, S. E.; Lutz, J. A.; Martin, K.; Raleigh, M. S.; Gersonde, R.; Lundquist, J. D.

    2014-12-01

    Forests cover over 40% of the seasonally snow-covered regions in North America. However, operational snow networks are located primarily in forest clearings, and optical remote sensing cannot see through tree canopies to detect forest snowpack. Due to the complex influence of the forest on snowpack duration, ground observations in forests are essential. We therefore consider the effectiveness of different strategies to observe snow covered area under forests. At our study location in the Pacific Northwest, we simultaneously deployed fiber-optic cable, stand-alone ground temperature sensors, and time-lapse digital cameras in three different forest treatments: control second-growth forest, thinned forest, and forest gaps (one tree height in diameter). We derived fractional snow covered area and snow duration metrics from the co-located instruments to assess optimal spatial resolution and sampling configuration. The fiber-optic cable and the camera detected a significant difference of 8 days in mean snow duration between the gap and control plots. Monte Carlo experiments based on our results suggest that 10 m spacing of self-recording ground temperature sensors across a 40 m forest plot will capture mean snow duration to ± 5 days whereas 6 m spacing reduces the 95% confidence interval to ± 3 days. We further tested the representativeness of sampling one plot per treatment group by observing snow duration across replicated forest plots at the same elevation, and at a set of forest plots 250 m higher. Relative relationships between snow duration in the forest treatments are consistent between replicated plots, elevation, and two winters of data.

  8. Observational and modeling studies of heat, moisture, precipitation, and global-scale circulation patterns

    NASA Technical Reports Server (NTRS)

    Vincent, Dayton G.; Robertson, Franklin

    1993-01-01

    The research sponsored by this grant is a continuation and an extension of the work conducted under a previous contract, 'South Pacific Convergence Zone and Global-Scale Circulations'. In the prior work, we conducted a detailed investigation of the South Pacific convergence zone (SPCZ), and documented many of its significant features and characteristics. We also conducted studies of its interaction with global-scale circulation features through the use of both observational and modeling studies. The latter was accomplished toward the end of the contract when Dr. James Hurrell, then a Ph.D. candidate, successfully ported the NASA GLA general circulation model (GCM) to Purdue University. In our present grant, we have expanded our previous research to include studies of other convectively-driven circulation systems in the tropics besides the SPCZ. Furthermore, we have continued to examine the relationship between these convective systems and global-scale circulation patterns. Our recent research efforts have focused on three objectives: (1) determining the periodicity of large-scale bands of organized convection in the tropics, primarily synoptic to intraseasonal time scales in the Southern Hemisphere; (2) examining the relative importance of tropical versus mid-latitude forcing for Southern Hemisphere summertime subtropical jets, particularly over the Pacific Ocean; and (3) estimating tropical precipitation, especially over oceans, using observational and budget methods. A summary list of our most significant accomplishments in the past year is given.

  9. Observing the ocean with different platforms/methods. Advantages, disadvantages and lessons learnt

    NASA Astrophysics Data System (ADS)

    Petihakis, George; Potiris, Manolis; Ntoumas, Manolis; Frangoulis, Kostas; Tsiaras, Kostas; Triantafyllou, George; Pollani, Annika

    2015-04-01

    Methods for observing/measuring the ocean, present remarkable diversity. In situ sampling or remote sensing, automated or not measurements with sensing probes, utilize different measuring principles, sample different parts of the system, are characterized by different accuracy/precision and sample over a large range of spatial and temporal scales with variable resolution. Measurements, quite often are dependent on the platform design and the platform interaction with the highly variable ambient environment. To add to the aforementioned issues that render the combination of data from different sources challenging from a scientific perspective, there are also a number of technical and data issues. These are important for the good operational status of the platforms, the smooth data flow and the collection of appropriate meta-data. Finally the raw data files need to be processed into a user friendly output format so the operator will be able to identify as early as possible sensor drift and failures. In this work, data from different observation platforms/sensors is analysed and compared, while mechanisms and processes responsible for differences are identified. More detailed, temperature, salinity and chlorophyll data from four fixed observing stations, one Ferry Box, satellites and a monthly in situ sampling program, is used. Main results indicate that a) regular calibration according to expected parameter range and well-defined, consistent deployment plan of proven sensors is sufficient for acquiring high quality data in the long term. Better knowledge of site specific response of new instrumentation is required for producing consistent long term data b) duplicate sensors on one platform considerably improve data flow and data quality c) if an area is sampled by multiple platforms, then platform dependent errors can be quantified d) fixed point observatories are efficient tools for assessing regional performance of satellite products. Higher vertical and temporal sampling rate of the upper 20m of the water column increase inter-comparability between the two platforms e) delayed mode, lower processing level data/meta-data should be archived and disseminated in addition to standard formatted files due to analysis artifacts and loss of information during transmission and processing.

  10. Observation and imitation of actions performed by humans, androids, and robots: an EMG study

    PubMed Central

    Hofree, Galit; Urgen, Burcu A.; Winkielman, Piotr; Saygin, Ayse P.

    2015-01-01

    Understanding others’ actions is essential for functioning in the physical and social world. In the past two decades research has shown that action perception involves the motor system, supporting theories that we understand others’ behavior via embodied motor simulation. Recently, empirical approach to action perception has been facilitated by using well-controlled artificial stimuli, such as robots. One broad question this approach can address is what aspects of similarity between the observer and the observed agent facilitate motor simulation. Since humans have evolved among other humans and animals, using artificial stimuli such as robots allows us to probe whether our social perceptual systems are specifically tuned to process other biological entities. In this study, we used humanoid robots with different degrees of human-likeness in appearance and motion along with electromyography (EMG) to measure muscle activity in participants’ arms while they either observed or imitated videos of three agents produce actions with their right arm. The agents were a Human (biological appearance and motion), a Robot (mechanical appearance and motion), and an Android (biological appearance and mechanical motion). Right arm muscle activity increased when participants imitated all agents. Increased muscle activation was found also in the stationary arm both during imitation and observation. Furthermore, muscle activity was sensitive to motion dynamics: activity was significantly stronger for imitation of the human than both mechanical agents. There was also a relationship between the dynamics of the muscle activity and motion dynamics in stimuli. Overall our data indicate that motor simulation is not limited to observation and imitation of agents with a biological appearance, but is also found for robots. However we also found sensitivity to human motion in the EMG responses. Combining data from multiple methods allows us to obtain a more complete picture of action understanding and the underlying neural computations.

  11. A simulation study to assess statistical methods for binary repeated measures data

    Microsoft Academic Search

    Elmabrok Masaoud; Henrik Stryhn

    2010-01-01

    Binary repeated measures data are commonly encountered in both experimental and observational veterinary studies. Among the wide range of statistical methods and software applicable to such data one major distinction is between marginal and random effects procedures. The objective of the study was to review and assess the performance of marginal and random effects estimation procedures for the analysis of

  12. Terrestrial gamma-ray flashes in the Fermi era: Improved observations and analysis methods

    NASA Astrophysics Data System (ADS)

    Briggs, Michael S.; Xiong, Shaolin; Connaughton, Valerie; Tierney, Dave; Fitzpatrick, Gerard; Foley, Suzanne; Grove, J. Eric; Chekhtman, Alexandre; Gibby, Melissa; Fishman, Gerald J.; McBreen, Shelia; Chaplin, Vandiver L.; Guiriec, Sylvain; Layden, Emily; Bhat, P. N.; Hughes, Maximilian; Greiner, Jochen; Kienlin, Andreas; Kippen, R. Marc; Meegan, Charles A.; Paciesas, William S.; Preece, Robert D.; Wilson-Hodge, Colleen; Holzworth, Robert H.; Hutchins, Michael L.

    2013-06-01

    A new data mode and new analysis methods are used to detect Terrestrial Gamma-ray Flashes (TGFs) with the Fermi Gamma-ray Burst Monitor (GBM) 10 times more frequently than previously. In 1037 h of observations at times and over regions for which TGFs are expected, 384 new TGFs were found in addition to the 39 TGFs and two Terrestrial Electron Beam events already detected without the new data mode and methodology. Cosmic ray showers were found to be an important background; they show characteristic signatures in the data of both GBM and the Fermi Large Area Telescope Calorimeter that enable their removal, leaving a sample estimated to consist of ?98% TGFs. The sample includes shorter TGFs than previously found with GBM. The true duration distribution likely contains additional short TGFs because their detection by GBM is limited by detector dead time. One-third of this sample has matches with locations from the World Wide Lightning Location Network (WWLLN)—maps of these locations show the geographic and meteorological features more clearly than maps of spacecraft locations. The intrinsic TGF rate is evaluated using the lightning rate maps of the Lightning Imaging Sensor, accounting for the detection efficiency of GBM as a function of spacecraft-source offset, from which we estimate a global TGF rate of ?400,000 per year. With continuous production of data in the new mode we estimate that GBM will detect ?850 TGFs per year.

  13. New Electrochemical Methods for Studying Nanoparticle Electrocatalysis and Neuronal Exocytosis

    NASA Astrophysics Data System (ADS)

    Cox, Jonathan T.

    This dissertation presents the construction and application of micro and nanoscale electrodes for electroanalytical analysis. The studies presented herein encompass two main areas: electrochemical catalysis, and studies of the dynamics of single cell exocytosis. The first portion of this dissertation engages the use of Pt nanoelectrodes to study the stability and electrocatalytic properties of materials. A single nanoparticle electrode (SNPE) was fabricated by immobilizing a single Au nanoparticle on a Pt disk nanoelectrode via an amine-terminated silane cross linker. In this manner we were able to effectively study the electrochemistry and electrocatalytic activity of single Au nanoparticles and found that the electrocatalytic activity is dependent on nanoparticle size. This study can further the understanding of the structure-function relationship in nanoparticle based electrocatalysis. Further work was conducted to probe the stability of Pt nanoelectrodes under conditions of potential cycling. Pt based catalysts are known to deteriorate under such conditions due to losses in electrochemical surface area and Pt dissolution. By using Pt disk nanoelectrodes we were able to study Pt dissolution via steady-state voltammetry. We observed an enhanced dissolution rate and higher charge density on nanoelectrodes than that previously found on macro scale electrodes. The goal of the second portion of this dissertation is to develop new analytical methods to study the dynamics of exocytosis from single cells. The secretion of neurotransmitters plays a key role in neuronal communication, and our studies highlight how bipolar electrochemistry can be employed to enhance detection of neurotransmitters from single cells. First, we developed a theory to quantitatively characterize the voltammetric behavior of bipolar carbon fiber microelectrodes and secondly applied those principles to single cell detection. We showed that by simply adding an additional redox mediator to the back-fill solution of a carbon fiber microelectrode, there is a significant enhancement in detection. Additionally we used solid state nanopores to detect individual phospholipid vesicles in solution. Vesicles are key cellular components that play essential biological roles especially in neurotransmission. This work represents preliminary studies in detection and size determination from vesicles isolated from individual cells.

  14. A unified Hinfinity adaptive observer synthesis method for a class of systems with both Lipschitz and monotone nonlinearities

    Microsoft Academic Search

    Ali Zemouche; Mohamed Boutayeb

    2009-01-01

    This paper investigates the problem of the H? adaptive observer design for a class of nonlinear dynamical systems. The main contribution consists in providing a unified synthesis method for systems with both Lipschitz and monotone nonlinearities (not necessarily Lipschitz). Thanks to the innovation terms into the nonlinear functions [M. Arcak, P. Kokotovic, Observer-based control of systems with slope-restricted nonlinearities, IEEE

  15. A method for determining the drift velocity of plasma depletions in the equatorial ionosphere using far-ultraviolet spacecraft observations

    Microsoft Academic Search

    S. H. Park; S. L. England; T. J. Immel; H. U. Frey; S. B. Mende

    2007-01-01

    The Far-Ultraviolet Imager (IMAGE-FUV) on board the NASA IMAGE satellite has been used to observe plasma depletions in the nightside equatorial ionosphere. Observations from periods around spacecraft apogee, during which equatorial regions are visible for several hours, have allowed the velocity of these plasma depletions to be determined. A new method for determining the velocity of these depletions using an

  16. A portable ergonomic observation method (PEO) for computerized on-line recording of postures and manual handling

    Microsoft Academic Search

    C Fransson-Hall

    1995-01-01

    A new portable ergonomic observation method (PEO) is presented. It is applicable to most professions and work tasks and requires only moderate human resources for data collection and analysis. Observations are made in real time directly at the workplace using a portable personal or hand-held computer, and data are accessible for immediate analysis and presentation. Duration and number of events

  17. The development of speed sensor observer for induction motor by using adaptive Neuro Fuzzy with back propagation learning method

    Microsoft Academic Search

    Era Purwanto; Sato Yukihiko; P Mauridhi Herry; Gigih Prabowo

    2006-01-01

    This paper proposed the simple method to develop observer for detects the speed of induction motor. Direct field-oriented induction motor drive system need rotor flux observer and rotor angular speed identifier. ANFIS is used for identifying parameter dynamics and system variable estimation, linear either non-linear. ANFIS with back propagation learning algorithm has applied to estimate flux rotor and identify rotor

  18. Peak Bagging of red giant stars observed by Kepler: first results with a new method based on Bayesian nested sampling

    E-print Network

    Corsaro, Enrico

    2015-01-01

    The peak bagging analysis, namely the fitting and identification of single oscillation modes in stars' power spectra, coupled to the very high-quality light curves of red giant stars observed by Kepler, can play a crucial role for studying stellar oscillations of different flavor with an unprecedented level of detail. A thorough study of stellar oscillations would thus allow for deeper testing of stellar structure models and new insights in stellar evolution theory. However, peak bagging inferences are in general very challenging problems due to the large number of observed oscillation modes, hence of free parameters that can be involved in the fitting models. Effciency and robustness in performing the analysis is what may be needed to proceed further. For this purpose, we developed a new code implementing the Nested Sampling Monte Carlo (NSMC) algorithm, a powerful statistical method well suited for Bayesian analyses of complex problems. In this talk we show the peak bagging of a sample of high signal-to-noi...

  19. The Maximum Similarity Shape Matching (MSSM) method applied to oil spill feature tracking observed in SAR imagery

    SciTech Connect

    Yan, Xiao-Hai; Clemente-Colon, P. [Univ. of Delaware, Newark, DE (United States)

    1997-06-01

    In this study, the Maximum Similarity in Shape Matching (MSSM) method was applied to a pair of airborne SAR images and two pairs of spaceborne SAR images in order to observe the small scale features of oil spill. The Gulf Stream front and the coast of Wales, UK, were chosen as the test sites. For the coast of Wales, spaceborne RADARSAT, ERS-1 and ERS-2 SAR images detected the persistence of slick features associated with the Sea Empress tanker massive oil spill, and showed the evolution of these features from February 22 to February 26, 1996. Drift speeds calculated using SAR images and MSSM method were as high as 11 cm/s. Deformation of the slick features was also evident throughout the five day period. The result of the investigation revealed the trajectory of this particular oil spill, and also demonstrated the possible future application of this method to analysis of SAR imagery, in general, and to oil spill monitoring, in particular.

  20. INTERLABORATORY STUDY OF INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROSCOPY METHOD 6010 AND DIGESTION METHOD 3050

    EPA Science Inventory

    The design, execution, and results of an interlaboratory study of Method 6010, 'Inductively Coupled Plasma Atomic Emission Spectroscopy,' are described. The study examined the application of the method to the analysis of solid-waste materials for 23 elements. Part of the interlab...

  1. Compliance with Seat Belt Use in Makurdi, Nigeria: An Observational Study

    PubMed Central

    Popoola, SO; Oluwadiya, KS; Kortor, JN; Denen-Akaa, P; Onyemaechi, NOC

    2013-01-01

    Background: Seat belts are designed to reduce injuries due to road crash among vehicle occupants. Aims: This study aims to determine the availability of seat belt in vehicles and compliance with seat belt use among vehicle occupants. Materials and methods: This was a 24-h direct observational study of seat belt usage among vehicle occupants in Makurdi, Benue State, Nigeria. By direct surveillance and using a datasheet, we observed 500 vehicles and their occupants for seat belt availability and compliance with its use. Chi-square test was used for test of significance between variables. Results: Twenty-five (5.0%) of the observed 500 vehicles had no seat belt at all. Overall, compliance was 277/486 (57.0%). Use of seat belt was highest in the afternoon with 124/194 (64.4%), followed by 111/188 (59.0%) in the morning and 42/95 (44.2%) at night. Compliance was highest among car occupants [209/308 (67.9%)] and private vehicles, and lowest among commercial vehicle occupants. Compliance among female drivers was 77.1% compared with 51.4% among male drivers. Among drivers, the mean age of seat belt users was 38.4 (7.7) years, which was significantly younger than the 41.3 (8.7) years mean age of non-users. Similar figures were obtained among other vehicle occupants. Conclusions: Compared with previous studies, seat belt usage has improved among Nigerian road users, but there is still room for improvement, especially early in the mornings and at nights. Since these were times when law enforcement agencies were not likely to be on the roads, we advocate for improved coverage by enforcement agents to enforce better compliance. PMID:24116327

  2. Survey of robust residual generation and evaluation methods in observer-based fault detection systems

    Microsoft Academic Search

    P. M. Frank; X. Ding

    1997-01-01

    The paper outlines recent advances of the theory of observer-based fault diagnosis in dynamic systems towards the design of robust techniques of residual generation and residual evaluation. Emphasis will be placed upon the latest contributions using frequency domain techniques including H? theory, nonlinear unknown input observer theory, adaptive observer theory, artificial intelligence including fuzzy logic, knowledge-based techniques and the natural

  3. A covariance study to optimize the optical observation strategy for Earth-orbiting objects

    NASA Astrophysics Data System (ADS)

    Cordelli, Emiliano; Schildknecht, Thomas; Vananti, Alessandro

    In the present paper an in-depth study of the covariance matrix obtained from a process of orbit determination is performed to improve the accuracy and maintenance of orbits of discovered space debris objects. Two covariance propagation methods exploiting two different computations of the State Transition Matrix (STM) are compared. The advantages of using an STM obtained from variational equations with respect to the matrix obtained by Taylor expansion are highlighted. The influence on the covariance propagation of empirical parameters during the orbit determination process is shown. Among the empirical parameters the constant forces along radial, along-track, cross-track directions, and the area-to-mass ratio are taken into account. Subsequently a study using simulations and covariance analysis is performed to try to identify the optimal configuration of observations and follow-ups to obtain the most accurate orbit propagation. In this analysis the influence of the orbit shape, of the relative object-observer geometry, and of the interval between discovery and follow-ups is taken into account.

  4. Regression analysis with nested effects in epidemiological studies: Assessment of a method eliminating one level of clustering

    Microsoft Academic Search

    F. Beaudeau; C. Fourichon; K. Frankena

    1996-01-01

    The analysis of binary data originating from clustered observations is often a problem in epidemiological studies. In most epidemiological studies on cattle, clustering occurs at two levels: cows are clustered within herds and lactation records are clustered within cows. This paper proposes and assesses a method of eliminating one level of clustering in regression analysis.Data from an observational study were

  5. SARAL/AltiKa observations for the studies of ice cover on lakes and oceans

    NASA Astrophysics Data System (ADS)

    Kouraev, Alexei; Zakharova, Elena; Remy, Frederique; Fleury, Sara; Guerreiro, Kevin; Willmes, Sascha; Suknev, Andrei

    2015-04-01

    With the launch of SARAL/AltiKa satellite mission scientific community has now a new source of information to study ice cover on water bodies and oceans. AltiKa observations provide a continuity with the previous satellite radar altimetry observations from ERS-1, -2 and ENVISAT mission that have the same orbit. Moreover, with the new Ka-band altimeter it gives new insights into the ice cover structure and properties. We present studies of ice cover on lakes (Lake Baikal) and Arctic ocean (for leads and polynyas detection). For Lake Baikal we use the synergy of simultaneous active (radar altimeter) and passive (radiometer) observations from radar altimetric satellites - SARAL/Altika and also TOPEX/Poseidon, Jason-1, ENVISAT and Geosat Follow-On. We present ice discrimination methodology from different satellite missions and discuss specificity of AltiKa observations. We analyse temporal variability of altimetric waveform parameters over ice-covered and ice-free surface for AltiKa and complement this analysis by satellite imagery (MODIS, Landsat), as well as our dedicated field observations of ice cover properties along the AltiKa tracks in spring 2013 and 2014. For the Arctic ocean we investigate the performance of SARAL/AltiKa to detect the leads and the coastal polynyas as well as its ability to represent spatial and temporal dynamic of water openings. The method consists first in analysis of along-track radar waveforms with collocated high-resolution Landsat images in order to localise ice/water transitions. We discuss the potential of several techniques that could be used for leads and polynya studies and for freeboard estimation. This research has been done in the framework of the Russian-French cooperation GDRI "CAR-WET-SIB", CNES TOSCA AO, ANR "CLASSIQUE", IDEX Transversalité InHERA, CNRS-Russia "Franco-Siberian Center for Research and Education" and PICS BaLaLaICA, ESA Proposal C1P.13132, Russian FZP 1.5 and EU FP7 "MONARCH-A" projects.

  6. Using peer observers to assess the quality of cancer multidisciplinary team meetings: a qualitative proof of concept study

    PubMed Central

    Harris, Jenny; Green, James SA; Sevdalis, Nick; Taylor, Cath

    2014-01-01

    Background Multidisciplinary team (MDT) working is well established as the foundation for providing cancer services in the UK and elsewhere. A core activity is the weekly meeting (or case conference/tumor boards) where the treatment recommendations for individual patients are agreed. Evidence suggests that the quality of team working varies across cancer teams, and this may impact negatively on the decision-making process, and ultimately patient care. Feedback on performance by expert observers may improve performance, but can be resource-intensive to implement. This proof of concept study sought to: develop a structured observational assessment tool for use by peers (managers or clinicians from the local workforce) and explore its usability; assess the feasibility of the principle of observational assessment by peers; and explore the views of MDT members and observers about the utility of feedback from observational assessment. Methods For tool development, the content was informed by national clinical consensus recommendations for best practice in cancer MDTs and developed in collaboration with an expert steering group. It consisted of ten subdomains of team working observable in MDT meetings that were rated on a 10-point scale (very poor to very good). For observational assessment, a total of 19 peer observers used the tool (assessing performance in 20 cancer teams from four hospitals). For evaluation, telephone interviews with 64 team members and all peer observers were analyzed thematically. Results The tool was easy to use and areas for refinement were identified. Peer observers were identified and most indicated that undertaking observation was feasible. MDT members generally reported that observational assessment and feedback was useful, with the potential to facilitate improvements in team working. Conclusion This study suggests that observation and feedback by peers may provide a feasible and acceptable approach to enhance MDT performance. Further tool refinement and validation is required. PMID:25143743

  7. Observational Research in Childhood Infectious Diseases (ORChID): a dynamic birth cohort study

    PubMed Central

    Lambert, Stephen Bernard; Ware, Robert S; Cook, Anne L; Maguire, Frances A; Whiley, David M; Bialasiewicz, Seweryn; Mackay, Ian M; Wang, David; Sloots, Theo P; Nissen, Michael D; Grimwood, Keith

    2012-01-01

    Introduction Even in developed economies infectious diseases remain the most common cause of illness in early childhood. Our current understanding of the epidemiology of these infections is limited by reliance on data from decades ago performed using low-sensitivity laboratory methods, and recent studies reporting severe, hospital-managed disease. Methods and analysis The Observational Research in Childhood Infectious Diseases (ORChID) study is an ongoing study enrolling a dynamic birth cohort to document the community-based epidemiology of viral respiratory and gastrointestinal infections in early childhood. Women are recruited antenatally, and their healthy newborn is followed for the first 2?years of life. Parents keep a daily symptom diary for the study child, collect a weekly anterior nose swab and dirty nappy swab and complete a burden diary when a child meets pre-defined illness criteria. Specimens will be tested for a wide range of viruses by real-time PCR assays. Primary analyses involves calculating incidence rates for acute respiratory illness (ARI) and acute gastroenteritis (AGE) for the cohort by age and seasonality. Control material from children when they are without symptoms will allow us to determine what proportion of ARIs and AGE can be attributed to specific pathogens. Secondary analyses will assess the incidence and shedding duration of specific respiratory and gastrointestinal pathogens. Ethics and dissemination This study is approved by The Human Research Ethics Committees of the Children's Health Queensland Hospital and Health Service, the Royal Brisbane and Women's Hospital and The University of Queensland. Trial registration clinicaltrials.gov NCT01304914. PMID:23117571

  8. Diffusive Shock Acceleration in Oblique MHD Shocks: Comparison with Monte Carlo Methods and Observations

    E-print Network

    Hyesung Kang; T. W. Jones

    1996-07-10

    We report simulations of diffusive particle acceleration in oblique magnetohydrodynamical (MHD) shocks. These calculations are based on extension to oblique shocks of a numerical model for ``thermal leakage'' injection of particles at low energy into the cosmic-ray population. That technique, incorporated into a fully dynamical diffusion-convection formalism, was recently introduced for parallel shocks by Kang \\& Jones (1995). Here, we have compared results of time dependent numerical simulations using our technique with Monte Carlo simulations by Ellison, Baring \\& Jones 1995 and with {\\it in situ} observations from the Ulysses spacecraft of oblique interplanetary shocks discussed by Baring \\etal (1995). Through the success of these comparisons we have demonstrated that our {diffusion-convection} method and injection techniques provide a practical tool to capture essential physics of the injection process and particle acceleration at oblique MHD shocks. In addition to the diffusion-convection simulations, we have included time dependent two-fluid simulations for a couple of the shocks to demonstrate the basic validity of that formalism in the oblique shock context. Using simple models for the two-fluid closure parameters based on test-particle considerations, we find good agreement with the dynamical properties of the more detailed diffusion-convection results. We emphasize, however, that such two-fluid results can be sensitive to the properties of these closure parameters when the flows are not truly steady. Furthermore, we emphasize through example how the validity of the two-fluid formalism does not necessarily mean that {\\it steady-state} two-fluid models provide a reliable tool for predicting the efficiency of particle acceleration in real shocks.

  9. Oxygen diffusion-concentration product in rhodopsin as observed by a pulse ESR spin labeling method.

    PubMed Central

    Subczynski, W K; Renk, G E; Crouch, R K; Hyde, J S; Kusumi, A

    1992-01-01

    Permeation of molecular oxygen in rhodopsin, an integral membrane protein, has been investigated by monitoring the bimolecular collision rate between molecular oxygen and the nitroxide spin label using a pulse electron spin resonance (ESR) T1 method. Rhodopsin was labeled by regeneration with the spin-labeled 9-cis retinal analogue in which the beta-ionone ring of retinal is replaced by the nitroxide tetramethyl-oxypyrrolidine ring. The bimolecular collision rate was evaluated in terms of an experimental parameter W(x), defined as T1(-1)(air,x)--T1(-1)(N2,x) where T1's are the spin-lattice relaxation times of the nitroxide in samples equilibrated with atmospheric air and nitrogen respectively, which is proportional to the product of local oxygen concentration and local diffusion coefficient (transport). W-values at the beta-ionone binding site in spin-labeled rhodopsin are in the range of 0.02-0.13 microseconds-1, which are 10-60 times smaller than W's in water and 1.1-20 times smaller than in model membranes in the gel phase, indicating that membrane proteins create significant permeation resistance to transport of molecular oxygen inside and across the membrane. W(thereby the oxygen diffusion-concentration product) is larger in the meta II-enriched sample than in rhodopsin, indicating light-induced conformational changes of opsin around the beta-ionone binding site. W decreases with increase of temperature for both rhodopsin and meta II-enriched samples, suggesting that temperature-induced conformational changes take place in both samples. These changes were not observable using conventional ESR spectroscopy. It is concluded that W is a sensitive monitor of conformational changes of proteins. PMID:1330032

  10. Does fasting in Ramadan ameliorate Lipid profile? A prospective observational study

    PubMed Central

    Akaberi, Arash; Golshan, Alireza; Moojdekanloo, Maryam; Hashemian, Maryam

    2014-01-01

    Background and Objectives: There are conflicting data on the effects of fasting in Ramadan in Muslim countries on Lipid profile. We aimed to evaluate the effect of fasting on lipid profiles and some ratios which are strong for predicting cardiovascular disease. Methods: This prospective observational study was done in Iran in 2012. Forty three persons were enrolled into the study. Their anthropometric measurement was done. Fasting plasma high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), total cholesterol (TC), and triglyceride (TG) were measured at baseline and after one month fasting during Ramadan by standard methods. Paired t test were used to compare lipid profiles before and after the intervention. Results : High density lipoprotein cholesterol was 33.10±6.53 mg/dL at baseline and increased to 42.49±8.44mg/dL (P <0.001). Fasting in Ramadan decreased serum LDL/HDL and TG/HDL ratios significantly (P <0.001). Triglyceride levels were unaffected. Low density lipoprotein and total cholesterol levels increased (P=0.008). Changes did not differ significantly between men and women. Conclusion: Fasting in Ramadan is effective to ameliorate High density lipoprotein, and LDL/HDL and TG/HDL ratios. Omitting one meal may be considered to control High density lipoprotein level. PMID:25097501

  11. Multiple-case Study Methods in Governance-related Research

    Microsoft Academic Search

    Jenny Stewart

    2011-01-01

    Relative to their single-case counterparts, multiple-case studies add observations for study, without taking the research design into more quantitative terrain. However, questions remain about the exact nature of the value that multi-case studies add to governance research. The present article addresses this gap by reviewing a sample of multiple-case study articles taken from leading public management journals and describing and

  12. Multiple-case Study Methods in Governance-related Research

    Microsoft Academic Search

    Jenny Stewart

    2012-01-01

    Relative to their single-case counterparts, multiple-case studies add observations for study, without taking the research design into more quantitative terrain. However, questions remain about the exact nature of the value that multi-case studies add to governance research. The present article addresses this gap by reviewing a sample of multiple-case study articles taken from leading public management journals and describing and

  13. Unsafe riding practice among electric bikers in Suzhou, China: an observational study

    PubMed Central

    Yang, Jie; Hu, Yihe; Du, Wei; Powis, Brent; Ozanne-Smith, Joan; Liao, Yilan; Li, Ning; Wu, Ming

    2014-01-01

    Background Electric bike (E-bike)-related deaths have been increasing rapidly in China and such injuries may be partly attributable to unsafe riding practice. Objectives To describe potentially unsafe riding behaviours among electric bikers (E-bikers) and to investigate factors influencing these practices in China. Methods In September 2012, a cross-sectional observation study including a speed measurement component was conducted in Wuzhong (an urban district) and Zhangjiagang (a rural district) of Suzhou, Jiangsu Province, China. Hand-held radar speed metres were used to read travelling speeds of E-bikes and a pro forma observation checklist was used to collect data on road riding practice. Mixed-effect logistic regressions were used to calculate adjusted ORs and 95% CIs for the association between speeding, road rule violations and helmet use and their influencing factors. Results Among 800 E-bikes with a speed reading, 70.9% exceeded the designed speed limit of 20?km/h. Among a further 20?647 E-bikers observed, 38.3% did not comply with the road rules when entering intersections; and only 2.2% wore helmets. No regional variation was identified between urban and rural areas. Male E-bikers were associated with more speeding and road rule violations, whereas riding a pedal-equipped E-bike was associated with less road rule violations and less helmet use. Conclusions Unsafe riding practices such as speeding, road rule violations and lack of helmet use were commonplace among E-bikers, especially among men. The study findings indicate that measures aimed at improving E-bike safety are required in China. PMID:24435891

  14. A prospective observational study of the outcome of central venous catheterization in 100 patients

    PubMed Central

    Kumar, Arun H. D.; Srinivasan, Nataraj M.; Thakkar, Jayashree M.; Mathew, Shaji

    2013-01-01

    Context: To Study the outcome following central vein catheterization in patients receiving chemotherapy. Aims: To Study the outcome of central venous catheterization in terms of difficulty during insertion, duration, incidence of infections and other complications and reasons for removal. Settings and Designs: Prospective observational study conducted in 100 patients attending to Gujarat Cancer and Research Institute. Materials and Methods: Both onco-medical and onco-surgical patients who required insertion of central venous catheters were enrolled after ethical approval from June 2008 to November 2010. The study comprised 100 patients. Statistical Analysis Used: Mean and percentage. Results: Mean duration of the indwelling catheter was 109 days for Hickman catheter, 39 days for cavafix and 59 days for certofix. Difficulty in insertion and arrhythmias were common complications. There were no incidences of major life threatening complications. Catheter related infection was 30%. The commonest reason for catheter removal was treatment completion 72%. The next frequent cause was catheter infection 14% and patient death 6%. Conclusions: Even though central venous catheterization is associated with acceptable complications, they serve a useful aid in management of patients on chemotherapy. PMID:25885724

  15. Hyperthermic intraperitoneal chemotherapy with cisplatin and paclitaxel in advanced ovarian cancer: a multicenter prospective observational study

    PubMed Central

    Coccolini, Federico; Campanati, Luca; Catena, Fausto; Ceni, Valentina; Jimenez Cruz, Jorge; Lotti, Marco; Magnone, Stefano; Napoli, Josephine; Rossetti, Diego; De Iaco, Pierandrea; Frigerio, Luigi; Pinna, Antonio; Runnebaum, Ingo; Ansaloni, Luca

    2015-01-01

    Objective Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been recently reported with favorable oncological outcomes as treatment of advanced epithelial ovarian cancer (EOC). The aim of this study was to demonstrate the feasibility of CRS+HIPEC with cisplatin and paclitaxel for the treatment of advanced EOC. Methods This is a prospective observational study of 54 patients, from April 2007 to October 2013, with primary or recurrent peritoneal carcinomatosis due to EOC. The mean age was 54.51±9.34. Thirty patients (59%) had primary EOC, and 24 patients (41%) had recurrent disease. Results Mean peritoneal cancer index was 10.11 (range, 0 to 28), complete cytoreduction (CC0) was achieved for 47 patients (87%), CC1 for seven patients (13%). Patients with suboptimal cytoreduction (CC2 and CC3) were not included in the study. The mean stay in intensive care unit was 4.73±5.51 days and the mean hospitalization time was 24.0±10.03 days. We did not observe any intraoperative death. Seven patients (13%) required additional operations. Three patients (5.6%) died within 30 days from the procedure. Severe complications were seen in 19 patients (35.2%). During the follow-up period, disease recurred in 33 patients (61.1%); the median disease-free survival time was 12.46 months and the median overall survival time was 32.91 months. Conclusion CRS+HIPEC with cisplatin and paclitaxel for advanced EOC is feasible with acceptable morbidity and mortality. Additional follow-up and further studies are needed to determine the effects of HIPEC on long term survival. PMID:25376916

  16. Using the Case Survey Method To Analyze Policy Studies

    ERIC Educational Resources Information Center

    Yin, Robert K.; Heald, Karen A.

    1975-01-01

    Describes a case study survey method that allows an analyst to aggregate (by means of a closed-ended questionnaire) the case study experiences and to assess the quality of each case study in a reliable and replicable manner. (Author/IRT)

  17. Methods For Planning Repeated Measures Degradation Studies Brian P. Weaver

    E-print Network

    Methods For Planning Repeated Measures Degradation Studies Brian P. Weaver Statistical Sciences National Laboratory Los Alamos, New Mexico 87545 April 16, 2012 Abstract Repeated measures degradation expected during a study. Such studies are often used to assess the shelf life of materials, components

  18. Helping Students Soar to Success on Computers: An Investigation of the Soar Study Method for Computer-Based Learning

    ERIC Educational Resources Information Center

    Jairam, Dharmananda; Kiewra, Kenneth A.

    2010-01-01

    This study used self-report and observation techniques to investigate how students study computer-based materials. In addition, it examined if a study method called SOAR can facilitate computer-based learning. SOAR is an acronym that stands for the method's 4 theoretically driven and empirically supported components: select (S), organize (O),…

  19. Detection method and observed data of high-energy gamma rays under the influence of quantum gravity

    SciTech Connect

    Kifune, T. [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan)

    2014-05-20

    The interaction of high-energy particles affected by quantum gravity is argued from the experimental viewpoint of raising a question, 'our detection method for high-energy ?-rays supplies trustworthy observation data and we are now seeing the true image of the universe through high-energy ?-rays?' The modified dispersion relation (MDR) for particles' energy and momentum is applied to the equation of energy-momentum conservation in particle reactions, to study the restriction imposed on the kinematic state of high-energy particles by the Lorentz invariance violation (LIV) due to quantum gravity, as a function of the incident particle energy of the reaction. The result suggests that the interaction utilized for ?-ray detection is not free from the effect of quantum gravity when ?-ray energy is higher than 10{sup 13} ? 10{sup 17} eV depending on models of MDR. Discussion is presented on the prospect of finding clear evidence of the LIV effect from ?-ray observations, as well as on the radiation and propagation mechanism of ?-rays under the influence of the LIV effect.

  20. Engineering Study of 500 ML Sample Bottle Transportation Methods

    SciTech Connect

    BOGER, R.M.

    1999-08-25

    This engineering study reviews and evaluates all available methods for transportation of 500-mL grab sample bottles, reviews and evaluates transportation requirements and schedules and analyzes and recommends the most cost-effective method for transporting 500-mL grab sample bottles.

  1. Information Technology in the Preservice Social Studies Methods Course.

    ERIC Educational Resources Information Center

    White, Charles S.

    1991-01-01

    Describes methods of using technology in a preservice social studies methods course that show how technology can support teacher planning and how technology can increase teacher effectiveness. Knowledge of instructional materials is discussed, and how to demonstrate the integration of technology into the curriculum through simulations for decision…

  2. New methods for in vivo studies of hepatic metabolism

    E-print Network

    Boyer, Edmond

    first glycogenolysis and then gluconeogenesis. In lipid metabolism, the liver oxidizes fatty acids, France (Received 29 November 1995; accepted 6 May 1996) Summary ― In vivo studies of liver dilution method, of the amounts of substrates taken up or produced by liver. New methods have been

  3. A Study of Methods for Estimating Distributions of Test Scores.

    ERIC Educational Resources Information Center

    Cope, Ronald T.; Kolen, Michael J.

    This study compared five density estimation techniques applied to samples from a population of 272,244 examinees' ACT English Usage and Mathematics Usage raw scores. Unsmoothed frequencies, kernel method, negative hypergeometric, four-parameter beta compound binomial, and Cureton-Tukey methods were applied to 500 replications of random samples of…

  4. Culture method to study fungal growth in solid fermentation

    Microsoft Academic Search

    Maurice Raimbault; Didier Alazard

    1980-01-01

    A new culture method is described to study the growth of Aspergillus niger on cassava meal in the solid state. This method uses preparations of the cooked starchy substrate as a homogeneous granulated product containing spores, salts and water. An incubation device aerates the mass with humidified air at a controlled temperature. Homogeneous development of mycelia, without sporulation, occurred in

  5. Comparing 3D Vector Field Visualization Methods: A User Study

    Microsoft Academic Search

    Andrew S. Forsberg; Jian Chen; David H. Laidlaw

    2009-01-01

    In a user study comparing four visualization methods for three-dimensional vector data, participants used visualizations from each method to perform five simple but representative tasks: 1) determining whether a given point was a critical point, 2) determining the type of a critical point, 3) determining whether an integral curve would advect through two points, 4) determining whether swirling movement is

  6. Saturated, Monounsaturated and Polyunsaturated Fatty Acids Intake and Risk of Pancreatic Cancer: Evidence from Observational Studies

    PubMed Central

    Yao, Xu; Tian, Zhong

    2015-01-01

    Background Although the relationship between dietary monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and saturated fatty acids (SFAs) intake and pancreatic cancer risk has been reported by several studies, the evidence is controversial. We firstly conducted this comprehensive meta-analysis to summarize the aforementioned evidence from observational studies. Methods The MEDLINE (PubMed), Embase, and ISI Web of Science databases were used to search for epidemiological studies of dietary SFA, MUFA, and PUFA and pancreatic cancer risk that were published until the end of June 2014. Random- or fixed-effects models were used to estimate the relative risks (RRs) and 95% confidence intervals (CIs). We also carried out subgroup, sensitivity, and publication bias analyses. Results We identified 13 case-control studies and 7 prospective studies which including 6270 pancreatic cancer cases in the meta-analysis of SFA, MUFA, and PUFA and risk of pancreatic cancer. The summary RR was 1.13 (95%CI = 0.94-1.35, I2 = 70.7%) for SFA, 1.00 (95%CI = 0.87-1.14, I2 = 43.4%) for MUFA, and 0.87 (95%CI = 0.75-1.00, I2 = 55.3%) for PUFA for high versus low intake categories. We found no evidence of publication bias. Conclusion In summary, findings of this study supports an inverse association between diets high in PUFA and pancreatic cancer risk. Further large prospective studies are warranted to report the results stratified by the subtypes of MUFA and PUFA and adjust for other potential risk factors to eliminate residual confounding. PMID:26110621

  7. The Verbotonal Method of Aural Rehabilitation: A Case Study

    ERIC Educational Resources Information Center

    Eisenberg, Diane; Santore, Frances

    1976-01-01

    A case study is presented of a 12-year-old child with a congenital profound bilateral sensori-neural hearing loss, who received rehabilitative audio-therapy according to the verbotonal method. (Author/LS)

  8. Measuring Agreement in Method Comparison Studies With Heteroscedastic Measurements

    E-print Network

    Choudhary, Pankaj Kumar

    typically has some clinical importance, e.g., concentration of a chemical, blood pressure, cholesterol level and clinical chemistry. These studies compare a new cheaper, simpler or less invasive method of measuring

  9. Grade 7 Science Social Studies Interdisciplinary on the Scientific Method

    ERIC Educational Resources Information Center

    Bates, Peter; Bannen, Joe

    1974-01-01

    A description is provided of activities for a junior high school science and social studies unit on teaching the scientific method and interrelationships between the scientist and the social scientist. (Author/KM)

  10. Qualitative PCR method for Roundup Ready soybean: interlaboratory study.

    PubMed

    Kodama, Takashi; Kasahara, Masaki; Minegishi, Yasutaka; Futo, Satoshi; Sawada, Chihiro; Watai, Masatoshi; Akiyama, Hiroshi; Teshima, Reiko; Kurosawa, Yasunori; Furui, Satoshi; Hino, Akihiro; Kitta, Kazumi

    2011-01-01

    Quantitative and qualitative methods based on PCR have been developed for genetically modified organisms (GMO). Interlaboratory studies were previously conducted for GMO quantitative methods; in this study, an interlaboratory study was conducted for a qualitative method for a GM soybean, Roundup Ready soy (RR soy), with primer pairs designed for the quantitative method of RR soy studied previously. Fourteen laboratories in Japan participated. Each participant extracted DNA from 1.0 g each of the soy samples containing 0, 0.05, and 0.10% of RR soy, and performed PCR with primer pairs for an internal control gene (Le1) and RR soy followed by agarose gel electrophoresis. The PCR product amplified in this PCR system for Le1 was detected from all samples. The sensitivity, specificity, and false-negative and false-positive rates of the method were obtained from the results of RR soy detection. False-negative rates at the level of 0.05 and 0.10% of the RR soy samples were 6.0 and 2.3%, respectively, revealing that the LOD of the method was somewhat below 0.10%. The current study demonstrated that the qualitative method would be practical for monitoring the labeling system of GM soy in kernel lots. PMID:21391499

  11. A Faster and Cheaper Method of Implementing States Observers using Artificial Neural Networks

    Microsoft Academic Search

    Ye Chow Kuang; M. P.-L. Ooi

    2007-01-01

    In modern control theory, a system is modeled as a functional block that receives an input and produces a corresponding output that is based on the internal states of the system. However, the internal states are generally not directly accessible to due to high costs and physical limitations; hence they are estimated from an observer. The states observer is a

  12. Parameter sensitivity study of the Nelder–Mead Simplex Method

    Microsoft Academic Search

    Peter C. Wang; Terry E. Shoup

    2011-01-01

    This paper presents a parameter sensitivity study of the Nelder–Mead Simplex Method for unconstrained optimization. Nelder–Mead Simplex Method is very easy to implement in practice, because it does not require gradient computation; however, it is very sensitive to the choice of initial points selected. Fan–Zahara conducted a sensitivity study using a select set of test cases and suggested the best

  13. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 30, METHOD 625 - BASE/NEUTRALS, ACIDS AND PESTICIDES

    EPA Science Inventory

    The work which is described in this report was performed for the purpose of validating, through an interlaboratory study, Method 625 for the analysis of the base/neutral, acid, and pesticide priority pollutants. This method is based on the extraction and concentration of the vari...

  14. An observational and numerical study of the sea breeze in the eastern Cantabrian coast (Spain)

    NASA Astrophysics Data System (ADS)

    Ander Arrillaga, Jon; Yagüe, Carlos; Sastre, Mariano; Román-Cascón, Carlos

    2015-04-01

    The sea breeze and its characteristics are well studied in the Mediterranean coast of the Iberian Peninsula, but not so in the Cantabrian coast, perhaps due to a lower prevalence of stable synoptic conditions during the summer period. However, it was found that the sea breeze was one of the main drivers of pollution episodes in the industrialised metropolitan area of Bilbao. In addition, an accurate prediction of this mesoscale phenomenon is fundamental for forecasting hot spells with predominant southerly gradient winds, especially in the eastern half of the Cantabrian Sea, during which can be recorded up to 40 °C close to the shore. In this work, an automated method is used for selecting sea breeze days [1], based in 6 filters that evaluate the observed synoptic and surface conditions in the Eastern Cantabrian, provided by the Basque and Spanish meteorological agencies. The main objective is to make an observational and numerical analysis of this phenomenon in the aforementioned region, focusing on the predictability of the Sea Breeze Index (SBI) [2] and the evolution of turbulent parameters such as the Turbulent Kinetic Energy (TKE). Numerical simulations are performed using the mesoscale model Weather Research and Forecast (WRF). The selection method fails filtering a non-sea-breeze day owing to a shift hint in the wind direction, which is predominantly southerly making temperature reach around 40 °C in one of the meteorological stations. This day is simulated both with and without updating the Sea Surface Temperature (SST). The latter simulation leads to a more unrealistic situation. Furthermore, the Planetary Boundary Layer (PBL) height evolution given by the model is compared for a sea breeze and a non-sea-breeze day, concluding that the establishment of a maritime flux results in a lower diffusive capacity in the lower atmosphere, which would lead to a higher concentration of pollutants close to the surface. It is also found that the cause of the establishment of the sea breeze is the sharp decline in the value of the simulated SBI, not the value itself. Nonetheless, the complex coastline and topography cause evident spatial differences in this region, which are well represented in the outputs of the model as well as in the observed surface variables. [1] Borne, K. & Chen, D. (1998). A method for finding sea breeze days under stable synoptic conditions and its application to the Swedish west coast. Int. J. Climatol., 18, 901-914. [2] Simpson, J. E. (1994). Sea Breeze and Local Winds. Cambridge University Press, 234pp.

  15. Saving time: New methods and instrumentation for radio variability studies

    NASA Astrophysics Data System (ADS)

    Spitler, Laura Grace

    My thesis describes new instrumentation and signal processing techniques developed for time-domain studies of the radio sky and applies these techniques to a variety of radio astronomical data. Time-domain algorithms were developed for the SERENDIP V survey, a commensal SETI survey operating at the Arecibo Observatory. Along with collaborators at the University of California at Berkeley, I helped develop the high frequency resolution digital FFT spectrometers used to collected the data. No signal with the characteristics of being from an extraterrestrial intelligence was observed. A method for automatically classifying broadband and narrowband signals in raw frequency-time data is presented. It uses both the first and second moments of a spectrum to characterize the how broad or narrowband a signal is. Our applications of this technique to real data show that this algorithm is an effective tool for radio frequency interference excision. A survey for rare, bright radio transients was undertaken with a 3.8 m radio telescope on the roof of the Space Sciences Building on Cornell's campus. This survey involved the end-to-end development of the hardware, software, and data analysis. The data were searched from single, dispersed pulses, but none were found. Multi-frequency observations of the eclipsing, binary white dwarf system J0651 were conducted at the Arecibo Observatory to search for variable emission, both short-duration, "burst-like" and periodic emission. The system has an orbital period of only 12.75 min, and this fast rotation may generate radio emission if the stars are magnetic, but no emission was seen. Five new pulsars, including three Rotating Radio Transients (RRATs), were discovered in a single pulse analysis of 23 months of Pulsar ALFA (PALFA) data collected with the Mock spectrometers. We expanded the existing pipeline to include several new algorithms, including the spectral modulation index and a single pulse rating. In addition to the new discoveries, forty-seven previously known pulsars were redetected. From this work I conclude that considering the time domain is key to fully understanding the radio sky. Time-domain studies require special algorithms and instrumentation and particular attention must be made to managing radio frequency interference.

  16. Microcirculatory Changes in Term Newborns with Suspected Infection: An Observational Prospective Study

    PubMed Central

    Alba-Alejandre, Irene; Hiedl, Stephan; Genzel-Boroviczény, Orsolya

    2013-01-01

    Background. In adults severely disturbed microcirculatory flow can be observed by Orthogonal Polarized Spectral (OPS) imaging techniques during sepsis. Therefore we set out to assess for microcirculatory changes in term newborns with suspected early onset infection using OPS. Methods. OPS images were obtained prospectively from the vascular bed of the ear conch and upper arm of 47 newborns on their 1st, 2nd, and 3rd day of life. OPS sequences were analyzed semiquantitatively offline and blinded to clinical status of the infant. Flow in vessels was classified as continuous or noncontinuous flow and given as proportion of total vessels per image as in the studies in adults. Results. The proportion of vessels with continuous flow was significantly lower in the infants with infection (69% [56–81] versus 90% [87–94] (P = 0.0003)). None of the infants with infection was in shock or severely septic. Conclusion. In term neonates the microcirculatory flow is impaired in a large proportion of vessels even in mild to moderate infection. These changes can be observed at the onset of disease at the external ear, an optimal site for microcirculatory measurements in term infants. PMID:23365583

  17. Microcirculatory changes in term newborns with suspected infection: an observational prospective study.

    PubMed

    Alba-Alejandre, Irene; Hiedl, Stephan; Genzel-Boroviczény, Orsolya

    2013-01-01

    Background. In adults severely disturbed microcirculatory flow can be observed by Orthogonal Polarized Spectral (OPS) imaging techniques during sepsis. Therefore we set out to assess for microcirculatory changes in term newborns with suspected early onset infection using OPS. Methods. OPS images were obtained prospectively from the vascular bed of the ear conch and upper arm of 47 newborns on their 1st, 2nd, and 3rd day of life. OPS sequences were analyzed semiquantitatively offline and blinded to clinical status of the infant. Flow in vessels was classified as continuous or noncontinuous flow and given as proportion of total vessels per image as in the studies in adults. Results. The proportion of vessels with continuous flow was significantly lower in the infants with infection (69% [56-81] versus 90% [87-94] (P = 0.0003)). None of the infants with infection was in shock or severely septic. Conclusion. In term neonates the microcirculatory flow is impaired in a large proportion of vessels even in mild to moderate infection. These changes can be observed at the onset of disease at the external ear, an optimal site for microcirculatory measurements in term infants. PMID:23365583

  18. ?-Blockers and All-Cause Mortality in Adults with Episodes of Acute Bronchitis: An Observational Study

    PubMed Central

    Rutten, Frans H.; Groenwold, Rolf H. H.; Sachs, Alfred P. E.; Grobbee, Diederick E.; Hoes, Arno W.

    2013-01-01

    Background Recent observational studies suggest that ?-blockers may improve long-term prognosis in patients with chronic obstructive pulmonary disease (COPD). We assessed whether ?-blocker use improves all-cause mortality in patients with episodes of acute bronchitis. Methods An observational cohort study using data from the electronic medical records of 23 general practices in the Netherlands. The data included standardized information about daily patient contacts, diagnoses, and drug prescriptions. Cox regression was applied with time-varying treatment and covariates. Results The study included 4,493 patients aged 45 years and older, with at least one episode of acute bronchitis between 1996 and 2006. The mean (SD) age of the patients was 66.9 (11.7) years, and 41.9% were male. During a mean (SD) follow up period of 7.7 (2.5) years, 20.4% developed COPD. In total, 22.7% had cardiovascular comorbidities, resulting in significant higher mortality rates than those without (51.7% vs. 12.0%, p<0.001). The adjusted hazard ratio of cardioselective ?-blocker use for mortality was 0.62 (95% confidence interval [CI], 0.50–0.77), and 1.01 (95% CI 0.75–1.36) for non-selective ones. Some other cardiovascular drugs also reduced the risk of mortality, with adjusted HRs of 0.60 (95% CI 0.46–0.79) for calcium channel blockers, 0.88 (95% CI 0.73–1.06) for ACE inhibitors/angiotensin receptor blockers, and 0.42 (95% CI 0.31–0.57) for statins, respectively. Conclusion Cardiovascular comorbidities are common and increase the risk of mortality in adults with episodes of acute bronchitis. Cardioselective ?-blockers, but also calcium channel blockers and statins may reduce mortality, possibly as a result of cardiovascular protective properties. PMID:23840599

  19. Interferometry and shadow method observation millisecond laser interaction with silicon plate

    NASA Astrophysics Data System (ADS)

    Liang, Zhang; Ni, Xiaowu; Lu, Jian

    2015-05-01

    Studied steam velocity and observed liquid molten splash phenomenon during the millisecond laser interaction with silicon plate. First, the interference pictures are obtained about the millisecond laser interaction with silicon plate. The energy of the laser is 7.38 J, and the pulse width is 1 ms. The thickness of silicon plate is 0.3 mm. The results show, When the laser irradiated 233 ?s, the front surface of the silicon plate has been generated gasification; and When the laser irradiated 466 ?s, the back surface of the silicon plate also has been generated gasification. By two pictures of fringe locations and time intervals, during the laser irradiation 233-466 ?s, the steam velocity is 27.52 m/s in the front surface of the silicon plate, and during the laser irradiation 466-699 ?s, the steam velocity is 20.47 m/s in the back surface of the silicon plate which are calculated. Then, the shadow pictures are obtained about the millisecond laser interaction with the same silicon plate. The results show, When the laser irradiated 466 ?s, the front surface of the silicon plate has been generated molten liquid splash phenomenon; and When laser irradiated 699 ?s, the back surface of the silicon plate also has been generated. Meanwhile, Laser interaction with silicon plate at later, the front and back surface of the silicon plate appears molten liquid splashing at the same time, and splashing in the direction and other issues were discussed. Finally, use blackbody radiation theory, explained the reasons for melt splashing brightness higher than the illumination lightness.

  20. The Dominance Behavioral System and Psychopathology: Evidence from Self-Report, Observational, and Biological Studies

    PubMed Central

    Johnson, Sheri L.; Leedom, Liane J.; Muhtadie, Luma

    2012-01-01

    The dominance behavioral system (DBS) can be conceptualized as a biologically-based system which guides dominance motivation, dominant and subordinate behavior, and responsivity to perceptions of power and subordination. A growing body of research suggests that problems with the DBS are evident across a broad range of psychopathologies. We begin by describing psychological, social, and biological correlates of the dominance behavioral system (DBS). Extensive research suggests that externalizing disorders, mania-proneness, and narcissistic traits are related to heightened dominance motivation and behaviors. Mania and narcissistic traits also appear related to inflated self-perceptions of power. Anxiety and depression are related to subordination and submissiveness, as well as a desire to avoid subordination. Models of the DBS have received support from research with humans and animals; from self-report, observational, and biological methods; and using naturalistic and experimental paradigms. Limitations of available research include the relative lack of longitudinal studies using multiple measures of the DBS and the absence of relevant studies using diagnosed samples to study narcissistic personality disorder and bipolar disorder. We provide suggestions for future research on the DBS and psychopathology, including investigations of whether the DBS can be used to differentiate specific disorder outcomes; the need for more sophisticated biological research; and the value of longitudinal dynamical research. Implications of using the DBS as a tool in clinical assessment and treatment are discussed. PMID:22506751

  1. Comparative postural deformity studies by photogrammetric methods with structural illumination

    NASA Astrophysics Data System (ADS)

    Patorski, Krzysztof; Rafalowski, Maciej B.; Kujawinska, Malgorzata; Zawieska, Dorota; Podlasiak, Piotr; Nowotny, J.

    1995-03-01

    Detailed investigations of the projection moire and grid projection methods used for the computer aided studies of the shape of the muscle-osseous system and postural deformities are presented. The shape determination process is readily automated using the phase methods for analyzing the fringe patterns. The issue of subtracting the reference surface inherent to the measurement-by-comparison methods is discussed. Specialized medical software for studying the deformity of the back and front of the human body illustrated by clinical examples is presented.

  2. Quantitative study on dispersion relations of TIDs observed by an HF Doppler array

    NASA Technical Reports Server (NTRS)

    Tsutsui, M.; Ogawa, T.

    1985-01-01

    A quantitative study on the dispersion relation of traveling ionospheric disturbances (TIDs) was performed by using data obtained by an HF Doppler array. Observed data at three stations are digitized continuously with a sampling period of 10 sec. A schematic illustration of a running analysis method is given. Fourier components omega's and their wave vectors k's of the TIDs are calculated from these subset data from three stations by means of the cross-spectrum analysis. Diagrams of horizontal trace velocity V sub ph versus wave period T were also obtained. From these diagrams one can see clear cutoff periods of the internal mode of the atmospheric gravity waves. A morphological classification of the mode of the omega - k and V sub ph - T obtained through one year was performed. The estimation of the horizontal velocity vectors of the thermospheric wind form their dispersion relations was performed also. A key point of the method of obtaining the vectors is to estimate the tilt, in azimuthally different omega - k diagrams, of a resonant branch ascribed to the Brunt oscillations.

  3. Systematic social observation of children’s neighborhoods using Google Street View: a reliable and cost-effective method

    PubMed Central

    Odgers, Candice L.; Caspi, Avshalom; Bates, Christopher J.; Sampson, Robert J.; Moffitt, Terrie E.

    2012-01-01

    Background Children growing up in poor versus affluent neighborhoods are more likely to spend time in prison, develop health problems and die at an early age. The question of how neighborhood conditions influence our behavior and health has attracted the attention of public health officials and scholars for generations. Online tools are now providing new opportunities to measure neighborhood features and may provide a cost effective way to advance our understanding of neighborhood effects on child health. Method A virtual systematic social observation (SSO) study was conducted to test whether Google Street View could be used to reliably capture the neighborhood conditions of families participating in the Environmental-Risk (E-Risk) Longitudinal Twin Study. Multiple raters coded a subsample of 120 neighborhoods and convergent and discriminant validity was evaluated on the full sample of over 1,000 neighborhoods by linking virtual SSO measures to: (a) consumer based geo-demographic classifications of deprivation and health, (b) local resident surveys of disorder and safety, and (c) parent and teacher assessments of children’s antisocial behavior, prosocial behavior, and body mass index. Results High levels of observed agreement were documented for signs of physical disorder, physical decay, dangerousness and street safety. Inter-rater agreement estimates fell within the moderate to substantial range for all of the scales (ICCs ranged from .48 to .91). Negative neighborhood features, including SSO-rated disorder and decay and dangerousness corresponded with local resident reports, demonstrated a graded relationship with census-defined indices of socioeconomic status, and predicted higher levels of antisocial behavior among local children. In addition, positive neighborhood features, including SSO-rated street safety and the percentage of green space, were associated with higher prosocial behavior and healthy weight status among children. Conclusions Our results support the use of Google Street View as a reliable and cost effective tool for measuring both negative and positive features of local neighborhoods. PMID:22676812

  4. Telephone-based anticoagulation management in the homebound setting: a retrospective observational study

    PubMed Central

    Hassan, Samer; Naboush, Ali; Radbel, Jared; Asaad, Razan; Alkaied, Homam; Demissie, Seleshi; Terjanian, Terenig

    2013-01-01

    Background Anticoagulation management is currently performed through anticoagulation clinics or self-managed with or without the help of medical services. Homebound patients are a unique population that cannot utilize anticoagulation clinics or self-testing. Telephone-based anticoagulation management could be an alternative to the traditional methods of monitoring warfarin in this subgroup. The objective of this retrospective, observational study is to investigate the feasibility of warfarin management in homebound patients. Methods This study was performed through the use of telephone-based adjustments of warfarin dose based on an international normalized ratio (INR) result. Four hundred forty-eight homebound patients referred to the anticoagulation clinic at Staten Island University Hospital were visited at home by a phlebotomist; a blood sample was drawn for initial laboratory testing. A nurse practitioner then called the patient or designated person to relay the INR result and to direct dosage adjustment. INR results and dosage changes were entered into an electronic medical record and analyzed statistically. Results The mean percentage of INR values in range was 58.39%. The mean time when the INR was in the therapeutic range was 62.75%. The percent of patients who were therapeutically controlled decreased as the number of medications increased. The complication rate was 4% per patient year, with an equal distribution between bleeding and clotting. These values compared favorably to other studies in which monitoring was performed through anticoagulation clinics or self-monitoring. The cost per visit at our anticoagulation clinic was found to be approximately $300 compared with $82 when utilizing our homebound service. Conclusion Telephone-based management of warfarin therapy in the homebound setting is feasible. It can lower the cost of health care expenditures compared to other modalities of anticoagulation management. PMID:24348065

  5. An Observational Study of Bullying as a Contributing Factor in Youth Suicide in Toronto

    PubMed Central

    Sinyor, Mark; Schaffer, Ayal; Cheung, Amy H

    2014-01-01

    Objective Bullying has been identified as a potential contributing factor in youth suicide. This issue has been highlighted in recent widely publicized media reports, worldwide, in which deceased youth were bullied. We report on an observational study conducted to determine the frequency of bullying as a contributing factor to youth suicide. Method: Coroner records were reviewed for all suicide deaths in youth aged between 10 and 19 in the city of Toronto from 1998 to 2011. Data abstracted were recent stressors (including bullying), clinical variables, such as the presence of mental illness, demographics, and methods of suicide. Results: Ninety-four youth suicides were included in the study. The mean age was 16.8 years, and 70.2% were male. Bullying was present in 6 deaths (6.4%), and there were no deaths where online or cyberbullying was detected. Bullying was the only identified contributing factor in fewer than 5 deaths. The most common stressors identified were conflict with parents (21.3%), romantic partner problems (17.0%), academic problems (10.6%), and criminal and (or) legal problems (10.6%). Any stressor or mental and (or) physical illness was detected in 78.7% of cases. Depression was detected in 40.4% of cases. Conclusions: Our study highlights the need to view suicide in youth as arising from a complex interplay of various biological, psychological, and social factors of which bullying is only one. It challenges simple cause-and-effect models that may suggest that suicide arises from any one factor, such as bullying. PMID:25702362

  6. Study of hands-on activities in mathematics and science methods courses via interactive instructional television

    NASA Astrophysics Data System (ADS)

    Axtell Dean, Kay Esther

    The purpose of the study was to determine if student teachers who received training in mathematics and science methods courses via interactive instructional television received instruction on hands-on activities. Furthermore, the study focused on whether the student teachers used the hands-on activities in the classrooms in which they performed their student teaching. This assessment was done by comparing syllabi for the mathematics and science methods courses; viewing videos from the interactive instructional television mathematics and science methods courses; observation of the student teachers in the classroom; interviews with the faculty teaching the methods courses, student teachers, cooperating teachers, and university supervisors; and surveying the student teachers, coordinating teachers, and university supervisors with a questionnaire. The study shows that if the methods course instructor models hands-on activities by including them in the interactive instructional televisions broadcast, then student teachers are more likely to use hands-on activities in the classroom.

  7. A comparative study of two stochastic mode reduction methods

    SciTech Connect

    Stinis, Panagiotis

    2005-09-01

    We present a comparative study of two methods for thereduction of the dimensionality of a system of ordinary differentialequations that exhibits time-scale separation. Both methods lead to areduced system of stochastic differential equations. The novel feature ofthese methods is that they allow the use, in the reduced system, ofhigher order terms in the resolved variables. The first method, proposedby Majda, Timofeyev and Vanden-Eijnden, is based on an asymptoticstrategy developed by Kurtz. The second method is a short-memoryapproximation of the Mori-Zwanzig projection formalism of irreversiblestatistical mechanics, as proposed by Chorin, Hald and Kupferman. Wepresent conditions under which the reduced models arising from the twomethods should have similar predictive ability. We apply the two methodsto test cases that satisfy these conditions. The form of the reducedmodels and the numerical simulations show that the two methods havesimilar predictive ability as expected.

  8. A comparative study of three methods for robot kinematics.

    PubMed

    Aspragathos, N A; Dimitros, J K

    1998-01-01

    Three methods for the formulation of the kinematic equations of robots with rigid links are presented in this paper. The first and most common method in the robotics community is based on 4x4 homogeneous matrix transformation, the second one is based on Lie algebra, and the third one on screw theory expressed via dual quaternions algebra. These three methods are compared in this paper for their use in the kinematic analysis of robot arms. The basic theory and the transformation operators, upon which every method is based, are referenced. Three analytic algorithms are presented for the solution of the direct kinematic problem corresponding to each method, and the geometric significance of the transformation operators and parameters is explained. Finally, a comparative study on the computation and storage requirements for the three methods is worked out. PMID:18255932

  9. Neurological, psychiatric, ophthalmological, and endocrine complications in giant male prolactinomas: An observational study in Algerian population

    PubMed Central

    Chentli, Farida; Azzoug, Said; Daffeur, Katia; Akkache, Lina; Zellagui, Hadjer; Haddad, Meriem; Kalafate, Nadia

    2015-01-01

    Introduction: Prolactinomas are less frequent, but more invasive in males. Giant ones (?4 cm) are extremely rare in literature. Their neurological, psychiatric and endocrine complications are life threatening. Our aim was to report the largest mono center series in order to analyze their frequency, their characteristics, and their complications. Subjects and Methods: All patients had clinical examination, hormonal, ophthalmological, and radiological assessment based on computed tomography scan and cerebral magnetic resonance imaging. Positive diagnosis was based on clinical symptoms, high prolactin ± immunohistochemy study. Mixed adenomas were excluded by hormonal exploration and immunohistochemy. For those who received medical treatment only, a reduction in tumor size was considered a supplementary positive point for the diagnosis. Results: Among 154 male prolactinomas seen between 1987 and 2013, we observed 44 giant tumors (28.5%). Median age = 36 years, and 38.3% were under 30. Median tumor height = 53.95 mm (40–130) and median prolactin = 15,715 ng/ml (n < 20). Solid and cystic aspect ± calcifications was observed in 25%. 42 had cavernous sinuses invasion. Other invasions were: Posterior= 65.9%, anterior= 63.6%, temporal= 15.9% and frontal = 9%. For endocrine complications: Hypogonadism = 98.4%, thyrotroph and corticotroph deficits were seen in respectively 34%, and 32%. Posterior pituitary insufficiency was observed in one case. For ophthalmological complications: Optic atrophy = 46%, Ptosis = 6.8%, diplopia/strabismus = 4.5%. Neurological complications were: Memory loss and/or unconsciousness = 18.2%, epilepsy = 15.9%, frontal syndrome = 9% and obstructive hydrocephalus = 6.8%. Conclusion: Giant prolactinomas account for 28% in our population. Severe neurological complications are frequent. But, obstructive hydrocephalus is rare, which argues for a slow progression. PMID:25932390

  10. A learning-based method for image super-resolution from zoomed observations

    Microsoft Academic Search

    Manjunath V. Joshi; Subhasis Chaudhuri; Rajkiran Panuganti

    2005-01-01

    Abstract We propose a technique for super-resolution imaging of a scene from observations at different camera zooms. Given a sequence of images with different zoom factors of a static scene, we obtain a picture of the entire scene at a resolution corresponding to the most zoomed,observation. The high resolution image is modeled,through appropriate parameterization and the parameters are learnt from

  11. An application of methods for clustered binary responses to a cardiovascular study with small sample size

    Microsoft Academic Search

    Luta Gheorghe; Gary G. Koch; Wayne E. Cascio; William T. Smith

    1998-01-01

    This paper discusses statistical methods for a cardiovascular study in which each of eight animals had a dichotomous outcome observed for each of several treatments. There were five treatments in all shunt, control, two doses of a test drug for potentially causing an unfavorable car- diovascular event and a combination of the test drug and a counteracting agent. Exact conditional

  12. A method for lunar roving vehicle position determination from three landmark observations with a sun compass

    NASA Technical Reports Server (NTRS)

    Blucker, T. J.; Stimmel, G. L.

    1971-01-01

    A simplified method is described for determining the position of the lunar roving vehicle on the lunar surface during Apollo 15. The method is based upon sun compass azimuth measurements of three lunar landmarks. The difference between the landmark azimuth and the sun azimuth is measured and the resulting data are voice relayed to the Mission Control Center for processing.

  13. Analytical methods used in a study of coke oven effluent.

    PubMed

    Schulte, K A; Larsen, D J; Hornung, R W; Crable, J V

    1975-02-01

    In a coke oven study conducted by NIOSH, selected chemical analyses of airborne particulates, vapors, and metals in the emissions from five coke ovens were done. Eight sampling procedures and seven analytical techniques were used to analyze samples collected for the study. Six of the analytical methods used are discussed. PMID:1146677

  14. Study on the Treatment of Refractory Leachate by Electrolytic Method

    Microsoft Academic Search

    Qi-Guang Zou; Gong-Ming Zhou

    The treatment of the refractory leachate by electrolytic method was studied in batch and continuous experiments. The influence of operational factors on the treatment efficiency had been evaluated. The optimum operational parameters were recommended to provide reference for the design of field scale projects when the biologically treated effluent was treated by electrolysis in this study.

  15. LABORATORY SIMULATION METHODS FOR STUDYING COMPLEX COLLABORATIVE TASKS

    E-print Network

    McCrickard, Scott

    LABORATORY SIMULATION METHODS FOR STUDYING COMPLEX COLLABORATIVE TASKS William D. Humphries, Dennis. Carroll Penn State University State College, PA This paper describes a new laboratory model developed for studying complex CSCW phenomena. In our prior work a more ecological laboratory approach was developed

  16. Mapped Chebyshev pseudospectral method to study multiple scale phenomena

    Microsoft Academic Search

    Adrian Alexandrescu; Jose R. Salgueiro; V ´ õctor; M. Perez-Garc

    In the framework of mapped pseudospectral methods, we use a polynomial-type mapping function in order to describe accurately the dynamics of systems developing small size structures. Using error criteria related to the spectral interpolation error, the polynomial-type mapping is compared against previously proposed mappings for the study of collapse and shock wave phenomena. As a physical application, we study the

  17. HPLC-MS-based methods for the study of metabonomics

    Microsoft Academic Search

    Ian D. Wilson; Robert Plumb; Jennifer Granger; Hilary Major; Rebecca Williams; Eva M. Lenz

    2005-01-01

    The development and use of HPLC-MS for the study of metabonomics is reviewed. To date the technique has been applied to the analysis of urine samples obtained from studies in rodents in investigations of physiological variation (e.g., factors such as strain, gender, diurnal variation, etc.) and toxicity. Examples are provided of the use of conventional HPLC, capillary methods and the

  18. Exploiting the power law distribution properties of satellite fire radiative power retrievals: A method to estimate fire radiative energy and biomass burned from sparse satellite observations

    Microsoft Academic Search

    S. S. Kumar; D. P. Roy; L. Boschetti; R. Kremens

    2011-01-01

    Biomass burned retrieved conventionally from FRP significantly sensitive to samplingNew method based on observed FRP power law properties solves this sensitivityNew method demonstrated with ground and satellite fire observations

  19. Choice of observational study design impacts on measurement of antipsychotic risks in the elderly: a systematic review

    PubMed Central

    2012-01-01

    Background Antipsychotics are frequently and increasingly prescribed to treat the behavioural symptoms associated with dementia despite their modest efficacy. Evidence regarding the potential adverse events of antipsychotics is limited and little is known about the longer-term safety of these medicines in the elderly. The aim of this review was to determine the impact of the choice of observational study design and methods used to control for confounding on the measurement of antipsychotic risks in elderly patients. Methods We searched PUBMED and the Cochrane controlled trials register for double-blind randomised controlled trials (RCTs), meta-analyses and published observational studies of antipsychotics. Results Forty four studies were identified for the endpoints; death, cerebrovascular events, hip fracture and pneumonia. RCTs found a 20% to 30% increased risk of death, or an absolute increase of 1extra death per 100 patients with atypical antipsychotics compared to non-use. Cohort and instrumental variable analyses estimated between 2 to 7 extra deaths per 100 patients with conventional compared to atypical antipsychotics. RCTs found a 2 to 3 times increased risk of all cerebrovascular events with atypical antipsychotics compared to placebo and no association with serious stroke that required hospitalisation. Observational studies using cohort and self-controlled case-series designs reported similar results; no association where the endpoint was stroke causing hospitalisation and a doubling of risk when minor stroke was included. No RCTs were available for the outcome of hip fracture or pneumonia. Observational studies reported a 20% to 40% increased risk of hip fracture with both antipsychotic classes compared to non-use. The risk of pneumonia was a 2 to 3 times greater with both classes compared to non-use while a self-controlled case-series study estimated a 60% increased risk. Conventional antipsychotics were associated with a 50% greater hip fracture risk than atypical antipsychotics, while the risk of pneumonia was similar between the classes. Conclusions Choice of observational study design is critical in studying the adverse effects of antispychotics. Cohort and instrumental variable analyses gave more consistent results to clinical studies for mortality outcomes as have self-controlled case-series for the risk of cerebrovascular events and stroke. Observational evidence has highlighted the potential for antipsychotics to be associated with serious adverse events that were not reported in RCTs including hip fracture and pneumonia. Good quality observational studies are required, that employ appropriate study designs that are robust towards unmeasured confounding, to confirm the potential excess risk of hip fracture and pneumonia with antipsychotics. PMID:22682666

  20. The ETTAA study protocol: a UK-wide observational study of ‘Effective Treatments for Thoracic Aortic Aneurysm’

    PubMed Central

    Sastry, Priya; Hughes, Victoria; Hayes, Paul; Vallabhaneni, Srinivasa; Sharples, Linda; Thompson, Matt; Catarino, Pedro; Moorjani, Narain; Vale, Luke; Gray, Joanne; Cook, Andrew; Elefteriades, John A; Large, Stephen R

    2015-01-01

    Introduction Chronic thoracic aortic aneurysm (CTAA) affecting the arch or descending aorta is an indolent but life-threatening condition with a rising prevalence as the UK population ages. Treatment may be in the form of open surgical repair (OSR) surgery, endovascular stent grafting (ESG) or best medical therapy (BMT). Currently, there is no consensus on the best management strategy, and no UK-specific economic studies that assess outcomes beyond the chosen procedure, but this is required in the context of greater demand for treatment and limited National Health Service (NHS) resources. Methods and analysis This is a prospective, multicentre observational study with statistical and economic modelling of patients with CTAA affecting the arch or descending aorta. We aim to gain an understanding of how treatments are currently chosen, and to determine the clinical effectiveness and cost-effectiveness of the three available treatment strategies (BMT, ESG and OSR). This will be achieved by: (1) following consecutive patients who are referred to the teams collaborating in this proposal and collecting data regarding quality of life (QoL), medical events and hospital stays over a maximum of 5?years; (2) statistical analysis of the comparative effectiveness of the three treatments; and (3) economic modelling of the comparative cost-effectiveness of the three treatments. Primary study outcomes are: aneurysm growth, QoL, freedom from reintervention, freedom from death or permanent neurological injury, incremental cost per quality-adjusted life year gained. Ethics and dissemination The study will generate an evidence base to guide patients and clinicians to determine the indications and timing of treatment, as well as informing healthcare decision-makers about which treatments the NHS should provide. The study has achieved ethical approval and will be disseminated primarily in the form of a Health Technology Assessment monograph at its completion. Trial registration number ISRCTN04044627. PMID:26038360

  1. Initial Results of an MDO Method Evaluation Study

    NASA Technical Reports Server (NTRS)

    Alexandrov, Natalia M.; Kodiyalam, Srinivas

    1998-01-01

    The NASA Langley MDO method evaluation study seeks to arrive at a set of guidelines for using promising MDO methods by accumulating and analyzing computational data for such methods. The data are collected by conducting a series of re- producible experiments. In the first phase of the study, three MDO methods were implemented in the SIGHT: framework and used to solve a set of ten relatively simple problems. In this paper, we comment on the general considerations for conducting method evaluation studies and report some initial results obtained to date. In particular, although the results are not conclusive because of the small initial test set, other formulations, optimality conditions, and sensitivity of solutions to various perturbations. Optimization algorithms are used to solve a particular MDO formulation. It is then appropriate to speak of local convergence rates and of global convergence properties of an optimization algorithm applied to a specific formulation. An analogous distinction exists in the field of partial differential equations. On the one hand, equations are analyzed in terms of regularity, well-posedness, and the existence and unique- ness of solutions. On the other, one considers numerous algorithms for solving differential equations. The area of MDO methods studies MDO formulations combined with optimization algorithms, although at times the distinction is blurred. It is important to

  2. The 1% Rule in Four Digital Health Social Networks: An Observational Study

    PubMed Central

    2014-01-01

    Background In recent years, cyberculture has informally reported a phenomenon named the 1% rule, or 90-9-1 principle, which seeks to explain participatory patterns and network effects within Internet communities. The rule states that 90% of actors observe and do not participate, 9% contribute sparingly, and 1% of actors create the vast majority of new content. This 90%, 9%, and 1% are also known as Lurkers, Contributors, and Superusers, respectively. To date, very little empirical research has been conducted to verify the 1% rule. Objective The 1% rule is widely accepted in digital marketing. Our goal was to determine if the 1% rule applies to moderated Digital Health Social Networks (DHSNs) designed to facilitate behavior change. Methods To help gain insight into participatory patterns, descriptive data were extracted from four long-standing DHSNs: the AlcoholHelpCenter, DepressionCenter, PanicCenter, and StopSmokingCenter sites. Results During the study period, 63,990 actors created 578,349 posts. Less than 25% of actors made one or more posts. The applicability of the 1% rule was confirmed as Lurkers, Contributors, and Superusers accounted for a weighted average of 1.3% (n=4668), 24.0% (n=88,732), and 74.7% (n=276,034) of content. Conclusions The 1% rule was consistent across the four DHSNs. As social network sustainability requires fresh content and timely interactions, these results are important for organizations actively promoting and managing Internet communities. Superusers generate the vast majority of traffic and create value, so their recruitment and retention is imperative for long-term success. Although Lurkers may benefit from observing interactions between Superusers and Contributors, they generate limited or no network value. The results of this study indicate that DHSNs may be optimized to produce network effects, positive externalities, and bandwagon effects. Further research in the development and expansion of DHSNs is required. PMID:24496109

  3. An Observational Study on the Effects of Nadroparin-Based and Citrate-Based Continuous Venovenous Hemofiltration on Calcium Metabolism

    Microsoft Academic Search

    Peter H. J. van der Voort; Sonja R. Postma; W. Peter Kingma; E. Christiaan Boerma; Loek J. M. de Heide; Andries J. Bakker

    2007-01-01

    Backgrounds: To study calcium homeostasis during citrate-based compared to nadroparin-based CVVH in critically-ill patients with acute renal failure. Methods: 11 patients were observed during citrate anticoagulation, 9 with nadroparin and 10 controls. Citrate was chosen for patients with active or at risk for bleeding. Results: The controls had, at 24 h, a median serum iCa of 1.1 mmol\\/l, the citrate

  4. Belgian Observational Drug Utilization Study of Pimecrolimus Cream 1% in Routine Daily Practice in Atopic Dermatitis

    Microsoft Academic Search

    Marc De Backer; Marie-Anne Morren; Hugo Boonen; Bert Boyden; Andre Vertruyen; Pascal Lecomte; Catherine Paquay; Emmanuel Lesaffre; Julien Lambert

    2008-01-01

    Background: For reimbursement purposes of pimecrolimus cream 1%, the Belgian authorities asked to document its consumption, its topical corticosteroid-sparing effect and quality of life within the routine clinical practice. Objectives: We aimed to address the 3 queries of the Belgian authorities. Methods: An open-label, observational, multicentre, 1-year study under drug prescription was performed. Results: A total of 416 consecutive patients

  5. Non-steroidal anti-inflammatory drugs and cardiac failure: meta-analyses of observational studies and randomised controlled trials

    Microsoft Academic Search

    Paul A Scott; Gabrielle H. Kingsley; David L Scott

    2008-01-01

    Aims: To determine the risks of cardiac failure with non-steroidal anti-inflammatory drugs (NSAIDs) and the specific risks with Cox-2 specific NSAIDs (COXIBs). Methods: We performed meta-analyses examining the risks of developing cardiac failure in observational studies and in randomised controlled trials (RCTs) involving patients with arthritis and non-rheumatic disorders. Electronic databases and published bibliographies were systematically searched (1997-2008). Results: Five

  6. Empiric broad-spectrum antibiotic therapy of nosocomial pneumonia in the intensive care unit: a prospective observational study

    Microsoft Academic Search

    Francisco Álvarez-Lerma; Bernabe Alvarez; Pilar Luque; Francisco Ruiz; Jose-Maria Dominguez-Roldan; Elisabet Quintana; Cesar Sanz-Rodriguez

    2006-01-01

    INTRODUCTION: Antibiotic de-escalation, which consists of the initial institution of empiric broad-spectrum antibiotics followed by antibiotic streamlining driven by microbiological documentation, is thought to provide maximum benefit for the individual patient, while reducing the selection pressure for resistance. METHODS: To assess a carbapenem-based de-escalating strategy in nosocomial pneumonia (NP), a prospective observational study was conducted in critically ill patients with

  7. Hydration status and physiological workload of UAE construction workers: A prospective longitudinal observational study

    Microsoft Academic Search

    Graham P Bates; John Schneider

    2008-01-01

    BACKGROUND: The objective of the study was to investigate the physiological responses of construction workers labouring in thermally stressful environments in the UAE using Thermal Work Limit (TWL) as a method of environmental risk assessment. METHODS: The study was undertaken in May 2006. Aural temperature, fluid intake, and urine specific gravity were recorded and continuous heart rate monitoring was used

  8. Observational aspects of the study of plasma turbulence in solar flares

    NASA Astrophysics Data System (ADS)

    Firstova, N. M.

    1990-07-01

    Using two techniques (the polarization method and the Baranger-Mozer method) a study has been made of plasma turbulence in solar emission features. The study suggests the conclusion that the 0.02-0.03 plasma turbulence level (E = 1-2 kV/cm seems to be the highest achieved in flares.

  9. Using Mobile Technology to Observe Student Study Behaviors and Track Library Space Usage

    ERIC Educational Resources Information Center

    Thompson, Susan

    2015-01-01

    Libraries have become increasingly interested in studying the use of spaces within their buildings. Traditional methods for tracking library building use, such as gate counts, provide little information on what patrons do once they are in the library; therefore, new methods for studying space usage are being developed. Particularly promising are…

  10. Stress and cardiometabolic manifestations among Saudi students entering universities: a cross-sectional observational study

    PubMed Central

    2014-01-01

    Background In this observational study, we aimed to see whether transition in Saudi students entering university life could be a breeding stage for cardiometabolic risk factor emergence and clustering. Methods A total of 1878 apparently healthy Saudi students of the Preparatory Year, King Saud University, Riyadh, KSA (1112 men and 766 women) spanning 2 academic years were included. They were divided into 2 groups based on the validated perceived stress test (PST). Anthropometrics were obtained and fasting blood samples were collected for measurement of fasting blood glucose and a lipid profile. Results PST score (>27) considered indicative of stress was noted in 44.4% of students. The prevalence of this score was higher in women than in men (49.7% versus 40.7%). The prevalence of obesity, hypertension and dyslipidemia was significantly higher in men than women (p?study sheds light on the social responsibility of universities in promoting a healthy lifestyle, particularly in this age group, when exposure to different kinds of stressors may result in body weight and metabolic changes. PMID:24755010

  11. Study of tectonic earthquake precursors by geodetic methods

    SciTech Connect

    Sigalov, V.M.

    1985-02-01

    Deformations of the Earth's surface which can be revealed by geodetic methods are among the most reliable earthquake precursors. A brief list is presented of geodetic leveling methods which have revealed the precursors of several earthquakes. To confirm the accuracy of determination of precursors of earthquakes based on the results of repeated leveling in epicenter zones and observations at Alma-Ata, the magnitudes of 7 earthquakes which occurred in northern Tien Shan during measurement of tectonic precursors were calculated and compared to valves based on seismologic measurements. The agreement found is satisfactory. A scientifically well-founded program of tectonic movements by geodetic methods in the northern Tien Shan has thus established the presence of tectonic precursors of earthquakes, determined the distances over which they are manifested and shown the possiblity of using the results of geodetic measurements in combiantion with geophysical and seismologic data to estimate the possible time of appearance of earthquake precursors.

  12. The Embedded Researcher Method for Involving Undergraduates in Research: New Data and Observations

    ERIC Educational Resources Information Center

    Rogers, Darrin L.; Kranz, Peter L.; Ferguson, Christopher J.

    2013-01-01

    Undergraduate research provides multiple educational advantages, and Hispanic students may reap particular benefits. The "embedded researcher" method avoids difficulties inherent in traditional apprenticeship models, providing meaningful research experience to multiple students within a standard didactic course structure while yielding…

  13. Optimization of energy window and evaluation of scatter compensation methods in myocardial perfusion SPECT using the ideal observer with and without model mismatch and an anthropomorphic model observer

    PubMed Central

    Ghaly, Michael; Links, Jonathan M.; Frey, Eric

    2015-01-01

    We used the ideal observer (IO) and IO with model mismatch (IO-MM) applied in the projection domain and an anthropomorphic channelized Hotelling observer (CHO) applied to reconstructed images to optimize the acquisition energy window width and to evaluate various scatter compensation methods in the context of a myocardial perfusion single-photon emission computed tomography (SPECT) defect detection task. The IO has perfect knowledge of the image formation process and thus reflects the performance with perfect compensation for image-degrading factors. Thus, using the IO to optimize imaging systems could lead to suboptimal parameters compared with those optimized for humans interpreting SPECT images reconstructed with imperfect or no compensation. The IO-MM allows incorporating imperfect system models into the IO optimization process. We found that with near-perfect scatter compensation, the optimal energy window for the IO and CHO was similar; in its absence, the IO-MM gave a better prediction of the optimal energy window for the CHO using different scatter compensation methods. These data suggest that the IO-MM may be useful for projectiondomain optimization when MM is significant and that the IO is useful when followed by reconstruction with good models of the image formation process.

  14. Myocardial infarction and individual nonsteroidal anti-inflammatory drugs meta-analysis of observational studies

    PubMed Central

    Varas-Lorenzo, Cristina; Riera-Guardia, Nuria; Calingaert, Brian; Castellsague, Jordi; Salvo, Francesco; Nicotra, Federica; Sturkenboom, Miriam; Perez-Gutthann, Susana

    2013-01-01

    Objective To conduct a systematic review of observational studies on the risk of acute myocardial infarction (AMI) with use of individual nonsteroidal anti-inflammatory drugs (NSAIDs). Methods A search of Medline (PubMed) for observational studies published from 1990 to 2011 identified 3829 articles; 31 reported relative risk (RR) of AMI with use of individual NSAIDs versus nonuse of NSAIDs. Information abstracted in a standardized form from 25 publications was used for the meta-analysis on 18 independent study populations. Results Random-effects RR (95% confidence interval (CI)) was lowest for naproxen 1.06 (0.94–1.20), followed by celecoxib 1.12 (1.00–1.24), ibuprofen 1.14 (0.98–1.31), meloxicam 1.25 (1.04–1.49), rofecoxib 1.34 (1.22–1.48), diclofenac 1.38 (1.26–1.52), indometacin 1.40 (1.21–1.62), etodolac 1.55 (1.16–2.06), and etoricoxib 1.97 (1.35–2.89). Heterogeneity between studies was present. For new users, RRs (95% CIs) were for naproxen, 0.85 (0.73–1.00); ibuprofen, 1.20 (0.97–1.48); celecoxib, 1.23 (1.00–1.52); diclofenac, 1.41 (1.08–1.86); and rofecoxib, 1.43 (1.21–1.66). Except for naproxen, higher risk was generally associated with higher doses, as defined in each study, overall and in patients with prior coronary heart disease. Low and high doses of diclofenac and rofecoxib were associated with high risk of AMI, with dose–response relationship for rofecoxib. In patients with prior coronary heart disease, except for naproxen, duration of use ?3 months was associated with an increased risk of AMI. Conclusions Most frequently NSAIDs used in clinical practice, except naproxen, are associated with an increased risk of AMI at high doses or in persons with diagnosed coronary heart disease. For diclofenac and rofecoxib, the risk was increased at low and high doses. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23616423

  15. Pressure-forced seiches of large amplitude in inlets of the Balearic Islands 2. Observational study

    Microsoft Academic Search

    M. Garcies; D. Gomis; S. Monserrat

    1996-01-01

    In part 1 of this study, Gomis et al. [1993] proposed a possible mechanism for the generation of large-amplitude seiches observed in inlets of the Balearic Islands. In part 2 we revise the proposed mechanism in light of recent observations. These consist of simultaneous records of sea level\\/bottom pressure measured at three locations inside and outside Ciutadella inlet and atmospheric

  16. Study of ICME Structure Using LASCO White Light and STE Lab IPS Observations of Halo CMEs

    Microsoft Academic Search

    D. F. Webb; M. Tokumaru; B. V. Jackson; P. P. Hick

    2001-01-01

    As part of a long-term investigation of halo-like coronal mass ejections (CMEs) well observed in white light by the SOHO LASCO coronagraphs, we report on a study comparing our catalog of parameters and solar and solar wind associations of halo CMEs with interplanetary disturbances observed with the interplanetary scintillation (IPS) radio array of STE Lab in Japan. We have cataloged

  17. Are large Trojan asteroids salty? An observational, theoretical, and experimental study

    E-print Network

    Glotch, Timothy D.

    Are large Trojan asteroids salty? An observational, theoretical, and experimental study Bin Yang a: Trojan asteroids Infrared observations Asteroids, surfaces a b s t r a c t With a total mass similar to the main asteroid belt, the jovian Trojan asteroids are a major feature in the Solar System. Based upon

  18. Some observations on the Houbolt-Rainey and peak-hold methods of flutter onset prediction

    NASA Technical Reports Server (NTRS)

    Doggett, Robert V., Jr.

    1990-01-01

    A subcritical response method for flutter onset prediction developed by Houbolt and Rainey in 1958 is compared with the Peak-Hold Method which was apparently first applied to flutter onset prediction by Sandford, Abel, and Gray in the early 1970's. The rational argument presented shows that the two methods are not different, but are actually the same. So, because there is an analytical foundation for the Houbolt-Rainey Method, then there is the same analytical foundation for the Peak-Hold Method. Further, it is suggested that, in applying Peak-Hold Method in cases where turbulence is used as the excitation force, the variation of the reciprocal of the response amplitude with the reciprocal of the dynamic pressure to be used to extrapolate to flutter onset rather than the variation with dynamic pressure which is the current practice because the linear trend which is predicted to occur for the former is easier to extrapolate to the flutter condition than the nonlinear trend predicted to occur for the latter.

  19. Method of 'optimum observables' and implementation of neural networks in physics investigations

    SciTech Connect

    Boos, E. E.; Bunichev, V. E.; Dudko, L. V.; Markina, A. A. [Moscow State University, Institute of Nuclear Physics (Russian Federation)

    2008-02-15

    A separation of a signal of various physics processes from an overwhelming background is one of the most important problems in contemporary high-energy physics. The application of various multivariate statistical methods, such as the neural-network method, has become one of the popular steps toward optimizing relevant analyses. The choice of optimum variables that would disclose distinctions between a signal and a background is one of the important elements in the application of neural networks. A universal method for determining an optimum set of such kinematical variables is described in the present article. The method is based on an analysis of Feynman diagrams contributing to signal and background processes. This method was successfully implemented in searches for single top-quark production with the D0 detector (Tevatron, Fermilab) in analyzing Run I and Run II data. Brief recommendations concerning an optimum implementation of the neural-network method in physics analysis are given on the basis of experience gained in searches for single top-quark production with the D0 detector.

  20. Ecological studies of ectomycorrhizal fungi: an analysis of survey methods

    Microsoft Academic Search

    Beáta B. Tóth; Zoltan Barta

    2010-01-01

    In this paper, by reviewing ecological studies of ectomycorrhizal fungi where both fruiting bodies and mycorrhizal root tips\\u000a were simultaneously surveyed, we investigate whether the diversity data obtained by the two methods leads to similar conclusions\\u000a about the underlying ecological processes of interest. Despite discrepancies in identifying species, we found that both survey\\u000a methods identified similar responses by ectomycorrhizal fungal

  1. Neutrinoless double beta decay studied with configuration mixing methods

    E-print Network

    Tomas R. Rodriguez; Gabriel Martinez-Pinedo

    2010-12-08

    We study neutrinoless double beta decay of several isotopes with state-of-the-art beyond self-consistent mean field methods to compute the nuclear matrix elements (NME). Generating coordinate method with particle number and angular momentum projection (GCM+PNAMP) is used for finding mother and granddaughter states and evaluating transition operators between different nuclei. We analyze explicitly the role of the deformation, pairing and configuration mixing in the evaluation of the NME.

  2. Nuclear Instruments and Methods in Physics Research A 476 (2002) 758764 Observation of radiation induced latchup in the readout

    E-print Network

    Ramello, Luciano

    2002-01-01

    Nuclear Instruments and Methods in Physics Research A 476 (2002) 758­764 Observation of radiation.80 Keywords: Latchup; Microelectronics; Nuclear electronics; Radiation tolerant electronics; Radiation effects of Physics and Nuclear Techniques, UMM, Cracow, Poland e Dipartimento di Scienze e Tecnologie Avanzate

  3. Novel flux linkage control of switched reluctance motor drives using observer and neural network-based correction methods

    Microsoft Academic Search

    H. S. Lim; D. Gray Roberson; N. S. Lobo; R. Krishnan

    2005-01-01

    From the perspective of control of switched reluctance motor (SRM) drives, current control is typically used as an inner loop control method. In this paper, observer and artificial neural network (ANN)-based novel flux linkage control of SRM drives is presented and examined as an alternate approach to current control. The main advantage of flux linkage control is computational simplicity due

  4. Psychological effects of implantable cardioverter defibrillator shocks. A review of study methods

    PubMed Central

    Manzoni, Gian Mauro; Castelnuovo, Gianluca; Compare, Angelo; Pagnini, Francesco; Essebag, Vidal; Proietti, Riccardo

    2015-01-01

    Background: The implantable cardioverter defibrillator (ICD) saves lives but clinical experience suggests that it may have detrimental effects on mental health. The ICD shock has been largely blamed as the main offender but empirical evidence is not consistent, perhaps because of methodological differences across studies. Objective: To appraise methodologies of studies that assessed the psychological effects of ICD shock and explore associations between methods and results. Data Sources: A comprehensive search of English articles that were published between 1980 and 30 June 2013 was applied to the following electronic databases: PubMed, EMBASE, NHS HTA database, PsycINFO, Sciencedirect and CINAHL. Review Methods: Only studies testing the effects of ICD shock on psychological and quality of life outcomes were included. Data were extracted according to a PICOS pre-defined sheet including methods and study quality indicators. Results: Fifty-four observational studies and six randomized controlled trials met the inclusion criteria. Multiple differences in methods that were used to test the psychological effects of ICD shock were found across them. No significant association with results was observed. Conclusions: Methodological heterogeneity of study methods is too wide and limits any quantitative attempt to account for the mixed findings. Well-built and standardized research is urgently needed. PMID:25698991

  5. The impact of limited search procedures for systematic literature reviews — A participant-observer case study

    Microsoft Academic Search

    Barbara Kitchenham; Pearl Brereton; Mark Turner; Mahmood Niazi; Stephen Linkman; Rialette Pretorius; David Budgen

    2009-01-01

    This study aims to compare the use of targeted manual searches with broad automated searches, and to assess the importance of grey literature and breadth of search on the outcomes of SLRs. We used a participant-observer multi-case embedded case study. Our two cases were a tertiary study of systematic literature reviews published between January 2004 and June 2007 based on

  6. ACTIVE MEDIA: Optical method for observing the hidden population inversion of nuclear states (possible experimental scheme)

    Microsoft Academic Search

    Lev A. Rivlin

    2002-01-01

    The possibility of observation of the hidden nuclear inversion below the lasing threshold from a change in the optical spectra of atoms containing the nuclei is considered. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics

  7. Characterisation of ice and THF hydrate slurry crystal size distribution by microscopic observation method

    Microsoft Academic Search

    Anthony Delahaye; Laurence Fournaison; Jacques Guilpart

    2010-01-01

    The objective of the present work is to characterise, using an experimental microscopic observation device, the crystal size distribution (CSD) of ice and tetrahydrofuran (THF) hydrate slurries, which can be used as two-phase refrigerant fluids for cold transportation and storage in the field of secondary refrigeration. Three different solutes (ethanol, propylene glycol and sodium chloride) were used to form ice

  8. Inferring CO2 sources and sinks from satellite observations: Method and application to TOVS data

    Microsoft Academic Search

    F. Chevallier; M. Fisher; P. Peylin; S. Serrar; P. Bousquet; F.-M. Bréon; A. Chédin; P. Ciais

    2005-01-01

    Properly handling satellite data to constrain the inversion of CO2 sources and sinks at the Earth surface is a challenge motivated by the limitations of the current surface observation network. In this paper we present a Bayesian inference scheme to tackle this issue. It is based on the same theoretical principles as most inversions of the flask network but uses

  9. Combining Bayesian methods and aircraft observations to constrain the HO. + NO2 reaction rate

    Microsoft Academic Search

    B. H. Henderson; R. W. Pinder; J. Crooks; R. C. Cohen; A. G. Carlton; H. O. T. Pye; W. Vizuete

    2011-01-01

    Tropospheric ozone is the third strongest greenhouse gas, and has the highest uncertainty in radiative forcing of the top five greenhouse gases. Throughout the troposphere, ozone is produced by radical oxidation of nitrogen oxides (NOx = NO + NO2). In the upper troposphere (8-10 km), current chemical transport models under-estimate nitrogen dioxide (NO2) observations. Improvements to simulated NOx emissions from

  10. Extravasation of contrast medium during CT examination: an observational case-control study

    PubMed Central

    Alami, Zayneb; Nasri, Siham; Ahid, Samir; Kacem, Hanane Hadj

    2015-01-01

    Introduction Extravasation is an adverse reaction to intravenous injection of contrast medium (CM) during CT examination. The objectives of this study are to determine the frequency, management and outcomes of extravasations and to assess risk factors for extravasation. Methods Every incident of extravasation which occurred between March 2012 and March 31, 2013 was recorded in an extravasation form. Ethics Committee approval was obtained and the patients gave their consent to participate in the study. Data collected in the form included patients’ age, sex, comorbidities, symptoms, CM used, injection mode, site and rate, extravasated volume, location of extravasation, severity of injury, treatment and patient outcome. Each case was matched with 4 controls of the same age ± 5 years and the same gender when possible. Results Extravasation occurred in 18 (7 women, 11 men) out of 2,000 injections of CM (0.9%) with a median age of 53 (10-78) years. Automated injection was performed in all cases with a mean rate of 1.7ml/s. Large extravasated volumes (? 50ml) were more observed in patients undergoing CT angiography (28.6% vs. 6.6%, although not significant P=0.112). Multivariate analysis revealed a significant association between patients with cardiac diseases and extravasation (OR: 7.3, 95% CI (1.09-49.05), P=0.04) whereas the injection rate is a protective factor from extravasation (P=0.002). Conclusion Extravasation of CM results in mild to moderate adverse effects in all cases. Our study suggests that patients with cardiac disease are more predisposed to contrast extravasation than others. Further and larger studies are needed to confirm this trend. PMID:26090047

  11. Multifactorial comparative study of spatial point pattern analysis methods.

    PubMed

    Wallet, F; Dussert, C

    1997-08-01

    A way of studying cooperative behaviour of biological entities (proteins, cells, etc.) is by using topographical analysis: the quantification of the spatial patterns formed by the entities considered as points. Five methods of topographical analysis were compared in terms of discriminant power, stability of parameters, methodological bias and algorithms. We tested five methods (nearest neighbour distribution, radial distribution, Voronoï paving, quadrat count, minimal spanning tree graph) which generated nine parameters on four simulated models (random point process, hardcore model and two cluster models) and on experimental cellular models. The method which offers the best discrimination power and stability seems to be the minimal spanning tree graph edge length distribution. PMID:9245582

  12. The Observation and Study of ELP V5-120 Conformational Changes 

    E-print Network

    Zhou, Qian

    2012-10-24

    and secondary/tertiary structure formation. In this thesis, the collapse process of ELP was studied with differential scanning calorimetry (DSC). In DSC thermal cycling, a clear conformational transition was observed. Also, a transiently stable state of ELP V5...

  13. User-friendly tools on handheld devices for observer performance study

    NASA Astrophysics Data System (ADS)

    Matsumoto, Takuya; Hara, Takeshi; Shiraishi, Junji; Fukuoka, Daisuke; Abe, Hiroyuki; Matsusako, Masaki; Yamada, Akira; Zhou, Xiangrong; Fujita, Hiroshi

    2012-02-01

    ROC studies require complex procedures to select cases from many data samples, and to set confidence levels in each selected case to generate ROC curves. In some observer performance studies, researchers have to develop software with specific graphical user interface (GUI) to obtain confidence levels from readers. Because ROC studies could be designed for various clinical situations, it is difficult task for preparing software corresponding to every ROC studies. In this work, we have developed software for recording confidence levels during observer studies on tiny personal handheld devices such as iPhone, iPod touch, and iPad. To confirm the functions of our software, three radiologists performed observer studies to detect lung nodules by using public database of chest radiograms published by Japan Society of Radiological Technology. The output in text format conformed to the format for the famous ROC kit from the University of Chicago. Times required for the reading each case was recorded very precisely.

  14. Prospective Observational Study of Ocular Health in ISS Crews - The Ocular Health Study

    NASA Technical Reports Server (NTRS)

    Otto, C.; Barr, Y.; Platts, S.; Ploutz-Snyder, R.; Sargsyan, A.; Alexander, D.; Riascos, R.; Gibson, C.; Patel, N.

    2015-01-01

    INTRODUCTION: The Visual Impairment Intracranial Pressure (VIIP) syndrome is currently NASA's number one human space flight risk. The syndrome, which is related to microgravity exposure, manifests with changes in visual acuity (hyperopic shifts, scotomas), changes in eye structure (optic disc edema, choroidal folds, cotton wool spots, globe flattening, and dilated optic nerve sheaths), and in some cases with documented increased intracranial pressure (ICP) postflight. While the eye appears to be the main affected end organ of this syndrome, the ocular effects are thought to be related to underlying changes in the vascular system and the central nervous system. The leading hypotheses for the development of VIIP involve microgravity-induced head-ward fluid shifts along with a loss of gravity-assisted drainage of venous blood from the brain, leading to cephalic congestion, decreased CSF resorption and increased ICP. Since 70% of ISS crewmembers have manifested clinical signs or symptoms of the VIIP syndrome, it is assumed that the majority have some degree of ICP elevation in-flight compared to the ground. Prolonged elevations of ICP can cause long-term reduced visual acuity and loss of peripheral visual fields, and have been reported to cause mild cognitive impairment in the analog terrestrial population of Idiopathic Intracranial Hypertension (IIH). These potentially irreversible health consequences underscore the importance of identifying the factors that lead to this syndrome and mitigating them. METHODS: The Ocular Health study expands on the required in-flight medical testing required of long-duration crewmembers assigned to an International Space Station (ISS) mission, to include 13 sessions over a three-year period. Pre- and postflight evaluations include functional eye exams (visual testing), structural eye exams (fundoscopy, ocular ultrasound, optical coherence tomography, optical biometry and biomicroscopy), intraocular pressure (IOP, tonometry), cardiovascular compliance (via ultrasound with concurrent ECG and blood pressure), noninvasive intracranial pressure (via pulsatility index, measured by transcranial Doppler), and Magnetic Resonance Imaging (MRI) to assess brain anatomy. In-flight evaluations include visual testing, optical coherence tomography, fundoscopy, tonometry, cardiovascular compliance and transcranial Doppler. RESULTS: Preflight, in-flight and postflight data will be presented for five Ocular Health subjects. These data will include: visual acuity, refraction, fundoscopy, OCT, ocular ultrasound, vascular compliance, TCD, IOP and MRI. One-year postflight data will be presented for two of these subjects. Data indicates that vascular compliance, retro-orbital pressure and IOP affect retinal nerve fiber layer swelling. DISCUSSION: This prospective study aims to understand the etiology of the VIIP syndrome, establish preflight baseline characteristics, define the temporal sequence for the appearance of signs and symptoms, characterize the nature of in-flight changes, document the postflight time course for recovery to baseline, and determine the impact of prolonged changes on crew health. Data from this study will improve the understanding of VIIP incidence, signs, symptoms, susceptibilities, timeline for development and recovery, and aid in guiding the development of countermeasures and targeted treatments for preventing the VIIP syndrome and its complications.

  15. Changes in dental plaque following hospitalisation in a critical care unit: an observational study

    PubMed Central

    2013-01-01

    Introduction Previous research has suggested that deterioration in oral health can occur following hospitalisation. The impact of such deterioration could increase the risk of oral disease, reduce quality of life and increase the potential for healthcare-associated infections (HCAI) such as healthcare-associated pneumonia (HAP). However, the strength of the evidence is limited by, amongst other factors, the few observational studies published that assess oral health longitudinally. In view of the microbiological component of oral diseases and HCAIs, the objective of this study was to investigate the microbiological changes in dental plaque following hospitalisation in a Critical Care Unit (CCU): (1) total number of cultivable bacteria and (2) presence and changes in specific HAP pathogens. Methods We conducted a prospective, longitudinal observational study in the CCU of University College Hospital, London. Study participants were recruited within 24 hours of admission. Dental plaque samples were collected from up to six sites per patient. The primary outcome was microbiological change from baseline to seven days with additional analysis for participants still present at day 14. Results 50 patients were recruited with 36 available for review at one week, with early discharge accounting for much of the loss to follow-up. The median total viable count of the plaque microbiota at baseline was 4.40 × 105 cfu/ml and increased at week one to 3.44 × 106 cfu/ml. The total viable microbe counts increased by a median of 2.26 × 106 cfu/ml from baseline to week one (95% CI: 3.19 × 106, 1.24 × 107) and this was statistically significant (P < 0.01). Specific HAP bacteria were detected in 26% of participants sampled, although accounted for a relatively low proportion of the total viable bacteria. Conclusion Total bacterial count of dental plaque increases during hospitalisation in CCU. This finding, together with the colonisation of dental plaque by HAP bacteria strengthens the evidence for a deterioration in oral health in CCU and a risk factor for negative health and quality of life outcomes. PMID:24007571

  16. Pharmacotherapy of elderly patients in everyday anthroposophic medical practice: a prospective, multicenter observational study

    PubMed Central

    2010-01-01

    Background Pharmacotherapy in the older adult is a complex field involving several different medical professionals. The evidence base for pharmacotherapy in elderly patients in primary care relies on only a few clinical trials, thus documentation must be improved, particularly in the field of complementary and alternative medicine (CAM) like phytotherapy, homoeopathy, and anthroposophic medicine. This study describes diagnoses and therapies observed in elderly patients treated with anthroposophic medicine in usual care. Methods Twenty-nine primary care physicians in Germany participated in this prospective, multicenter observational study on prescribing patterns. Prescriptions and diagnoses were reported for each consecutive patient. Data were included if patients were at least 60 years of age. Multiple logistic regression analysis was used to determine factors associated with anthroposophic prescriptions. Results In 2005, a total of 12 314 prescriptions for 3076 patients (68.1% female) were included. The most frequent diagnoses were hypertension (11.1%), breast cancer (3.5%), and heart failure (3.0%). In total, 30.5% of the prescriptions were classified as CAM remedies alone, 54.4% as conventional pharmaceuticals alone, and 15.1% as a combination of both. CAM remedies accounted for 41.7% of all medications prescribed (35.5% anthroposophic). The adjusted odds ratio (AOR) for receiving an anthroposophic remedy was significantly higher for the first consultation (AOR = 1.65; CI: 1.52-1.79), treatment by an internist (AOR = 1.49; CI: 1.40-1.58), female patients (AOR = 1.35; CI: 1.27-1.43), cancer (AOR = 4.54; CI: 4.12-4.99), arthropathies (AOR = 1.36; CI: 1.19-1.55), or dorsopathies (AOR = 1.34; CI: 1.16-1.55) and it decreased with patient age (AOR = 0.97; CI: 0.97-0.98). The likelihood of being prescribed an anthroposophic remedy was especially low for patients with hypertensive diseases (AOR = 0.36; CI: 0.32-0.39), diabetes mellitus (AOR = 0.17; CI: 0.14-0.22), or metabolic disorders (AOR = 0.17; CI: 0.13-0.22). Conclusion The present study is the first to provide a systematic overview of everyday anthroposophic medical practice in primary care for elderly patients. Practitioners of anthroposophic medicine prescribe both conventional and complementary treatments. Our study may facilitate further CAM-research on indications of, for example, dementia or adverse drug reactions in the elderly. PMID:20663129

  17. Efficacy and safety of moxifloxacin in community acquired pneumonia: a prospective, multicenter, observational study (CAPRIVI)

    PubMed Central

    2014-01-01

    Background Community acquired pneumonia (CAP) is a major cause of morbidity, hospitalization, and mortality worldwide. Management of CAP for many patients requires rapid initiation of empirical antibiotic treatment, based on the spectrum of activity of available antimicrobial agents and evidence on local antibiotic resistance. Few data exist on the severity profile and treatment of hospitalized CAP patients in Eastern and Central Europe and the Middle East, in particular on use of moxifloxacin (Avelox®), which is approved in these regions. Methods CAPRIVI (Community Acquired Pneumonia: tReatment wIth AVelox® in hospItalized patients) was a prospective observational study in 12 countries: Croatia, France, Hungary, Kazakhstan, Jordan, Kyrgyzstan, Lebanon, Republic of Moldova, Romania, Russia, Ukraine, and Macedonia. Patients aged >18 years were treated with moxifloxacin 400 mg daily following hospitalization with a CAP diagnosis. In addition to efficacy and safety outcomes, data were collected on patient history and disease severity measured by CRB-65 score. Results 2733 patients were enrolled. A low severity index (i.e., CRB-65 score <2) was reported in 87.5% of CAP patients assessed (n?=?1847), an unexpectedly high proportion for hospitalized patients. Moxifloxacin administered for a mean of 10.0 days (range: 2.0 to 39.0 days) was highly effective: 96.7% of patients in the efficacy population (n?=?2152) improved and 93.2% were cured of infection during the study. Severity of infection changed from “moderate” or “severe” in 91.8% of patients at baseline to “no infection” or “mild” in 95.5% at last visit. In the safety population (n?=?2595), 127 (4.9%) patients had treatment-emergent adverse events (TEAEs) and 40 (1.54%) patients had serious TEAEs; none of these 40 patients died. The safety results were consistent with the known profile of moxifloxacin. Conclusions The efficacy and safety profiles of moxifloxacin at the recommended dose of 400 mg daily are characterized in this large observational study of hospitalized CAP patients from Eastern and Central Europe and the Middle East. The high response rate in this study, which included patients with a range of disease severities, suggests that treatment with broader-spectrum drugs such as moxifloxacin is appropriate for patients with CAP who are managed in hospital. Trial registration ClinicalTrials.gov identifier: NCT00987792 PMID:24975809

  18. Comparison of Columnar Water Vapor Measurements During The Fall 1997 ARM Intensive Observation Period: Solar Transmittance Methods

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Michalsky, J. J.; Slater, D. W.; Barnard, J. C.; Halthore, R. N.; Liljegren, J. C.; Holben, B. N.; Eck, T. F.; Livingston, J. M.; Russell, P. B.

    2000-01-01

    In the fall of 1997, during an Intensive Observation Period (IOP), the Atmospheric Radiation Measurement (ARM) program conducted a study of water vapor abundance measurement at its Southern Great Plains (SGP) site. Among a large number of instruments, four sun-tracking radiometers were present to measure the columnar water vapor (CWV). All four solar radiometers retrieve CWV by measuring total solar transmittance in the 0.94-gm water vapor absorption band and subtracting contributions due to Rayleigh, ozone and aerosol transmittances. The aerosol optical depth comparisons among the same four radiometers has been presented elsewhere (Geophys. Res. Lett., 26, 17, 2725-2728, 1999). We have used three different methods to retrieve CWV. In a first round of comparison no attempt was made to standardize on the same radiative transfer model and its underlying water vapor spectroscopy. In the second round of comparison we used the same line-by-line code (which includes recently corrected H2O spectroscopy) to retrieve CAN from all four suntracking radiometers. This decreased the mean CWV by 8% or 13%. The spread of 8% in the solar radiometer results found when using the same model is an indication of the other-than-model uncertainties involved in determining CWV from solar transmittance measurements with current instrumentation.

  19. Potential impact of observational cohort studies in Japan on rheumatoid arthritis research and practice.

    PubMed

    Yamanaka, Hisashi; Tohma, Shigeto

    2006-01-01

    For better management of rheumatoid arthritis (RA) patients, we need information both from well-designed clinical trials, such as randomized controlled trials, and from observational cohorts. Observational cohort study has not been developed in Japanese RA patients; however, two cohorts, IORRA (formerly J-ARAMIS) from 2000 and NinJa by iR-net from 2002, have been established. These two cohorts are an important source not only for better management of Japanese RA patients but also for solutions to a variety of issues concerning RA clinical practice in general. In this minireview, necessities of observational cohort studies are discussed. PMID:16633925

  20. An observational analysis of science fair presentations made by seventh-grade students utilizing the Cooperative Inquiry Performance Method(c)

    Microsoft Academic Search

    Victor Guisao Jr.

    1999-01-01

    This study observed and analyzed how students with Cooperative Inquiry Performance Method(c) (CIPM(c)) experience presented and defended their science fair projects. CIPM(c) is a teaching and learning strategy which connects many learning theories into a package starting with group building activities (group norms and roles) to group inquiry-based lessons and experiments leading to a presentation and defense of the group's

  1. Two Stage Control Method Using a Disturbance Observer and a Kalman Filter

    Microsoft Academic Search

    Hiromitsu Ogawa; Manato Ono; Naohiro Ban; Yoshihisa Ishida

    2009-01-01

    ?? Abstract—This paper describes the two stage control using a disturbance observer and a Kalman filter. The system feedback uses the estimated state when it controls the speed. After the change-over point, its feedback uses the controlled plant output when it controls the position. To change the system continually, a change-over point has to be determined pertinently, and the controlled

  2. Estimating a model of dynamic activity generation based on one-day observations: Method and results

    Microsoft Academic Search

    Theo A. Arentze; Dick Ettema; Harry J. P. Timmermans

    2011-01-01

    In this paper we develop and explore an approach to estimate dynamic models of activity generation on one-day travel-diary data. Dynamic models predict multi-day activity patterns of individuals taking into account dynamic needs as well as day-varying preferences and time-budgets. We formulate an ordered-logit model of dynamic activity-agenda-formation decisions and show how one-day observation probabilities can be derived from the

  3. Decontamination Methods Used for Dental Burs – A Comparative Study

    PubMed Central

    Hugar, Deepa; Hugar, Santosh; Ranjan, Shashi; Kadani, Megha

    2014-01-01

    Aims and Objectives: Infection control and modes of sterilizations are the key factors to avoid cross transmission of infection in the field of dentistry. Transmission of disease or infection is noted with improper sterilization of reused instruments. Dental burs are the most important tool in any endodontic or conservative procedures of teeth involving tooth contouring, restorative filling procedures and endodontic procedures. Hence, the present study is undertaken to assess the efficacy of different methods of sterilization or decontamination which are routinely used in dental clinics. Materials and Methods: For the present study 96 round diamond burs were selected and divided into 6 groups. These burs were used for the access cavity preparation to get contamination and subjected for bacteriological culture. After getting base line date burs were subjected to manual scrubbing, hot air oven, glass bead sterilizer, ultrasonic cleaner and autoclave to get post decontamination data. Results: The study revealed that mean colony forming units/ml of Streptococcus mutans decreased maximum for autoclave with 80% reduction, for Lactobacilli 76% reduction and for Candida albicans maximum reduction seen for glass bead sterilizer with 74%. Conclusion: Findings of our study revealed that none of the methods used were found to be absolutely efficacious in the decontamination of dental burs. However, among the experimental groups used in the present study, autoclave was found to be the relatively best method. PMID:25121062

  4. Study on wireless data transmission of an autonomous water vehicle for ocean observation

    Microsoft Academic Search

    Wei Gu; Jianhua Wang; Jianxin Chu; Xixia Huang

    2008-01-01

    In this paper, a wireless data transmission system used in unmanned surface vehicles is presented. To improve reliability, wireless local network based on IP is employed. Through interface protocol, multi-modal data from different observation instruments or equipments are converted into the uniform specification suitable for transmission. Different control methods of data transmission are discussed. Experiment results from a unmanned surface

  5. Effect of statin therapy on mortality from infection and sepsis: a meta-analysis of randomized and observational studies

    PubMed Central

    2014-01-01

    Introduction Observational data have suggested that statin therapy may reduce mortality in patients with infection and sepsis; however, results from randomized studies are contradictory and do not support the use of statins in this context. Here, we performed a meta-analysis to investigate the effects of statin therapy on mortality from infection and sepsis. Methods We searched electronic databases (PubMed and Embase) for articles published before November 2013. Randomized or observational studies reporting the effects of statin therapy on mortality in patients with infection or sepsis were eligible. Randomized and observational studies were separately pooled with relative risks (RRs) and random-effects models. Results We examined 5 randomized controlled trials with 867 patients and 27 observational studies with 337,648 patients. Among the randomized controlled trials, statins did not significantly decrease in-hospital mortality (RR, 0.98; 95% confidence interval (CI), 0.73 to 1.33) or 28-day mortality (RR, 0.93; 95% CI, 0.46 to 1.89). However, observational studies indicated that statins were associated with a significant decrease in mortality with adjusted data (RR, 0.65; 95% CI, 0.57 to 0.75) or unadjusted data (RR, 0.74; 95% CI, 0.59 to 0.94). Conclusions Limited evidence suggests that statins may not be associated with a significant reduction in mortality from infection and sepsis. Although meta-analysis from observational studies showed that the use of statins was associated with a survival advantage, these outcomes were limited by high heterogeneity and possible bias in the data. Therefore, we should be cautious about the use of statins in infection and sepsis. PMID:24725598

  6. The development of an optical scanner method for observation of plant root dynamics

    Microsoft Academic Search

    Masako Dannoura; Yuji Kominami; Hiroyuki Oguma; Yoichi Kanazawa

    2008-01-01

    In order to achieve continuous monitoring of the rhizosphere, we developed a simple method that uses a wide-view optical scanner inserted into the ground. The scanner system facilitates the analysis of image data and allows continuous monitoring by automating the capture and by fixing the position of the optical scanner. The system was tested in the laboratory and installed under

  7. New method for exploring super-Eddington active galactic nuclei by near-infrared observations

    Microsoft Academic Search

    N. Kawakatu; K. Ohsuga

    2011-01-01

    We propose a new method to explore the candidate super-Eddington active galactic nuclei (AGNs). We examine the properties of infrared (IR) emission from the inner edge of the dusty torus in AGNs, which are powered by super- or sub-Eddington accretion flows around black holes, by considering the dependence of the polar angle on the radiation flux of accretion flows. We

  8. Methods for attitude guidance and precise robust gyromoment control of large-scale agile observation spacecraft

    NASA Astrophysics Data System (ADS)

    Somov, Sergey; Butyrin, Sergey; Somov, Yevgeny

    2012-11-01

    Problems on guidance and robust gyromoment attitude control of agile information satellite for remote sensing the Earth surface are considered. Elaborated methods for dynamic research of the spacecraft programmed angular motion at principle modes under external and parametric disturbances, partial discrete measurement of the state and digital control of the gyro moment cluster by the excessive gyrodine schemes, are presented.

  9. OBSERVATION METHOD FOR THE HISTOLOGICAL STRUCTURE OF COOKED RICE KERNELS USING ADHESIVE TAPE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new method was developed to investigate histological structures of cooked rice kernels. A single kernel of rice was infiltrated with 100% ethanol by carrying the kernel through a graded series of ethanol-water mixtures. The rice kernel was then embedded in paraffin and sectioned on a standard micr...

  10. Identity method to study chemical fluctuations in relativistic heavy-ion collisions

    E-print Network

    M. Gazdzicki; K. Grebieszkow; M. Mackowiak; St. Mrowczynski

    2011-03-15

    Event-by-event fluctuations of the chemical composition of the hadronic final state of relativistic heavy-ion collisions carry valuable information on the properties of strongly interacting matter produced in the collisions. However, in experiments incomplete particle identification distorts the observed fluctuation signals. The effect is quantitatively studied and a new technique for measuring chemical fluctuations, the identity method, is proposed. The method fully eliminates the effect of incomplete particle identification. The application of the identity method to experimental data is explained.

  11. Identity method to study chemical fluctuations in relativistic heavy-ion collisions

    SciTech Connect

    Gazdzicki, Marek; Grebieszkow, Katarzyna; Mackowiak, Maja; Mrowczynski, Stanislaw [Goethe-Universitaet Frankfurt, Max-von-Laue Strasse 1, D-60438 Frankfurt am Main, Germany, and Institute of Physics, Jan Kochanowski University, ul. SwiePtokrzyska 15, PL-25-406 Kielce (Poland); Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, PL-00-662 Warszawa (Poland); Institute of Physics, Jan Kochanowski University, ul. SwiePtokrzyska 15, PL-25-406 Kielce (Poland) and Soltan Institute for Nuclear Studies, ul. Hoza 69, PL-00-681 Warszawa (Poland)

    2011-05-15

    Event-by-event fluctuations of the chemical composition of the hadronic final state of relativistic heavy-ion collisions carry valuable information on the properties of strongly interacting matter produced in the collisions. However, in experiments incomplete particle identification distorts the observed fluctuation signals. The effect is quantitatively studied and a new technique for measuring chemical fluctuations, the identity method, is proposed. The method fully eliminates the effect of incomplete particle identification. The application of the identity method to experimental data is explained.

  12. A study of numerical methods for hyperbolic conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Leveque, R. J.; Yee, H. C.

    1990-01-01

    In the present study of the behavior of typical numerical methods in the case of a model advection equation having a parameter-dependent source term, two approaches to the incorporation of the source terms are used: MacCormack-type predictor-corrector methods with flux limiters, and splitting methods in which the fluid dynamics and chemistry are handled in separate steps. The latter are found to perform slightly better. The model scalar equation is used to show that the incorrectness of the propagation speeds of discontinuities observed in the stiff case is due to the introduction of nonequilibrium values through numerical dissipation in the advection step.

  13. Cerebral blood flow velocity changes during upright positioning in bed after acute stroke: an observational study

    PubMed Central

    Aries, Marcel J; Elting, Jan Willem; Stewart, Roy; De Keyser, Jacques; Kremer, Berry; Vroomen, Patrick

    2013-01-01

    Objectives National guidelines recommend mobilisation in bed as early as possible after acute stroke. Little is known about the influence of upright positioning on real-time cerebral flow variables in patients with stroke. We aimed to assess whether cerebral blood flow velocity (CBFV) changes significantly after upright positioning in bed in the acute stroke phase. Design Observational study. Participants 47 patients with acute ischaemic stroke measured in the subacute phase after symptom onset and 20 healthy controls. Primary and secondary outcome measures We recorded postural changes in bilateral transcranial Doppler (primary outcome) and simultaneously recorded near-infrared spectroscopy, end-tidal CO2, non-invasive blood pressure data and changes in neurological status (secondary outcomes). Methods Postures included the supine, half sitting (45°), sitting (70°) and Trendelenburg (?15°) positions. Using multilevel analyses, we compared postural changes between hemispheres, outcome groups (using modified Rankin Scale) as well as between patients and healthy controls. Results The mean patient age was 62±15?years and median National Institute of Health Stroke Scale score on admission was 7 (IQR 5–14). Mean proportional CBFV changes on sitting were not significantly different between healthy controls and affected hemispheres in patients with stroke. No significant differences were found between affected and unaffected stroke hemispheres and between patients with unfavourable and favourable outcomes. During upright positioning, no neurological worsening or improvement was observed in any of the patients. Conclusions No indications were found that upright positioning in bed in mild to moderately affected patients with stroke compromises flow and (frontal)oxygenation significantly during the subacute phase of stroke. Supine or Trendelenburg positioning does not seem to augment real-time flow variables. PMID:23945730

  14. Presentation skills amongst surgical trainees at a national conference: an observational study

    PubMed Central

    Watts, Edward; Peacock, Oliver; Liyanage, Shehan; Elsey, Elizabeth; Lund, Jonathan

    2012-01-01

    Objectives The ability to deliver public presentations is important for doctors of all specialities. Despite this, there is little emphasis on training in presentation skills within medical curriculae. The aim of this paper was to establish the current standard of presentations being delivered by surgical trainees at a national conference and to confirm the need for further training. Design An observational study of 96 six-minute research presentations. Setting A national surgical conference in the United Kingdom. Participants Four independent observers each appraised 24 six-minute presentations by surgical trainees against a pre-determined standard. Main outcome measures A set of 19 audit criteria were established after a literature search to ascertain commonly accepted presentation standards. These outcome measures included keeping to time, number of slides used, the nature of slide content, methods of data representation, use of images and presentation style. Results A total of 61 (64%) presenters overran. The median number of slides used was 13 (range 6–28). Thirty-three (34%) presenters displayed slides with more than six bullet points on two or more occasions. Sixty-four (67%) presenters displayed whole paragraphs of text on two or more occasions. Sixty-eight (71%) presenters displayed raw numerical data in the course of their presentations. Seventy (73%) presenters used images. Thirty-one (32%) presenters repeatedly read out sentences word-for-word from their slides. Nineteen (20%) presenters appeared not to know their presentation content well. Conclusions Presentation skills amongst surgical trainees are well below those that should be aspired to. Efforts to improve training, motivation and the examples set by senior surgeons should be instigated in order to improve this situation. PMID:22666527

  15. Outbreaks of mumps: an observational study over two decades in a single hospital in Korea

    PubMed Central

    Ryu, Ji-Ung; Kim, Eun-Kyung; Youn, You-Sook; Rhim, Jung-Woo

    2014-01-01

    Purpose The introduction of the mumps vaccine has dramatically reduced the number of mumps cases, but outbreaks have recently occurred among highly vaccinated populations in developed countries. Epidemiological and clinical characteristics of patients with mumps admitted between 1989 and 2012 in a single hospital in Korea are described in the present study. Methods We retrospectively evaluated inpatients with mumps between 1989 and 2012 and outpatients and inpatients with mumps in 2011-2012. Results A total of 152 patients with mumps were admitted between 1989 and 2012, and 163 patients were recorded in 2011-2012. The highest number of admitted cases occurred in 1998 and 2012 (35 and 34 cases, respectively). Among the patients admitted in 2011-2012, the highest frequency was observed among people aged 15-19 years, and low frequency was observed in those aged <4 years and >20 years, compatible to the city data and national data. In patients admitted to our department in 1998 (35 cases) and in 2010-2012 (27 cases), there were significant differences in the mean age and the rate of secondary measles-mumps-rubella (MMR) vaccination, but had similar clinical features, including complications, except aseptic meningitis. Antimumps immunoglobulin (Ig) G was positive in 83% and 100%, and IgM was positive in 67% and 41%, respectively, in the two periods. Conclusion In Korea, recent mumps outbreaks have occurred mainly among secondary school students who received two doses of the MMR vaccine. The vaccinees might have a modified immune reaction to viral insults, manifesting modified epidemiological and clinical features. PMID:25324865

  16. Quantifying streamflow observation types importance to calibrating coupled groundwater/surface water models using frugal sensitivity analysis methods

    NASA Astrophysics Data System (ADS)

    Foglia, Laura; Neumann, Jakob; Hill, Mary; Harter, Thomas

    2015-04-01

    The importance of using different types of observations, such as heads, concentrations, groundwater age, with computationally frugal sensitivity analysis methods, has been widely demonstrated for models of groundwater flow and transport. In this work we present two examples of complex coupled surface water/ groundwater models in which head data and different types of streamflow data are used for sensitivity analysis and calibration. We demonstrate that the selection of streamflow data to be used in the process can be critical for a successful model calibration. The first example is the coupled groundwater/hydrological model developed for the Maggia Valley, Southern Switzerland. Here two different sensitivity analyses have been carried out: the first one with a limited amount of streamflow observations mainly concentrated in the peak of the hydrograph suggested the need to include more low and medium flows, and the second one including a better representation of all the parts of the hydrograph. The second example is the integrated surface water/groundwater model developed for the Scott Valley in Northern California. Using the knowledge provided from the Maggia example, in this specific case streamflow observations have been immediately identified as low, medium and high flows and different rules have been tested to select then the observations to include in each group. Examples of the effects of the various tests are presented. We can conclude that in this case there is the need to be careful with the amount of observations included in the analysis: we discovered that with too many observations and mainly with too many observations with potentially high measurement error it is difficult to properly calibrate the model. In both cases it is shown the importance to carefully represent all parts of the hydrographs in order to properly simulate the surface water system and, based on the Scott Valley example, potentially redundant observations or too many observations with a very high measurement error should be removed in the analysis. Furthermore, regarding important observations, linear computationally frugal methods were not always able to distinguish between moderately and unimportant observations. However, they consistently identified the most important observations which are critical to characterize relationships between parameters and to assess the worth of potential new data collection efforts. Importance both to estimate parameters and predictions of interest was readily identified.

  17. Quality of Diabetes Care: A cross-sectional observational study in Oman

    PubMed Central

    Al-Mandhari, Ahmed; Al-Zakwani, Ibrahim; El-Shafie, Omayma; Al-Shafaee, Mohammed; Woodhouse, Nicholas

    2009-01-01

    Objectives: The objective of this study was to evaluate the quality of diabetes care in Oman. Methods: This was a cross-sectional observational study. Fifty percent of all those attending six general health centres in June 2005 were systematically selected for the study. Descriptive statistics were used to describe the data. Results: A total of 430 diabetic subjects were included. Just over 61% percent of the subjects were female (n = 263). The overall mean age of the cohort was 52 ± 12 years ranging from 6 to 84 years. Only 40% (n = 171) and 39% (n = 169) of the diabetics had their random blood sugar (RBS) and fasting blood sugar (FBS) documented, respectively. However, 79% (n = 339) had either RBS or FBS done according to the records. Documentation for the other measurements ranged from 74% (n = 317) for HbA1c and LDL (low density lipoproteins)-cholesterol to 95% (n = 409) for systolic and diastolic blood pressure (SBP/DBP) readings. A total of 58% (n = 249) of patients had non-missing values of HbA1c, SBP/DBP, total cholesterol, LDL-cholesterol, HDL (high density lipoproteins)-cholesterol, and triglycerides. Only 2.4% (6 out of 249 diabetics) were simultaneously within goal for HbA1c (<7%), SBP/DBP (<=130/80mmHg), total cholesterol (<5.2mmol/L), LDL-cholesterol (<3.3mmol/L), HDL-cholesterol (>1.1 – <1.68mmol/L), and triglycerides (<1.8mmol/L). Conclusion: There was good documentation of values for the indicators used in the assessment of quality. However, the proportion (2.4%) of those meeting internationally recognised goals for the three diabetes-related factors was extremely low. PMID:21509272

  18. Bronchoscopy-Derived Correlates of Lung Injury following Inhalational Injuries: A Prospective Observational Study

    PubMed Central

    Jones, Samuel W.; Zhou, Haibo; Ortiz-Pujols, Shiara M.; Maile, Robert; Herbst, Margaret; Joyner Jr, Benny L.; Zhang, Hongtao; Kesic, Matthew; Jaspers, Ilona; Short, Kathleen A.; Meyer, Anthony A.

    2013-01-01

    Background Acute lung injury (ALI) is a major factor determining morbidity following burns and inhalational injury. In experimental models, factors potentially contributing to ALI risk include inhalation of toxins directly causing cell damage; inflammation; and infection. However, few studies have been done in humans. Methods We carried out a prospective observational study of patients admitted to the NC Jaycees Burn Center who were intubated and on mechanical ventilation for burns and suspected inhalational injury. Subjects were enrolled over an 8-month period and followed till discharge or death. Serial bronchial washings from clinically-indicated bronchoscopies were collected and analyzed for markers of cell injury and inflammation. These markers were compared with clinical markers of ALI. Results Forty-three consecutive patients were studied, with a spectrum of burn and inhalation injury severity. Visible soot at initial bronchoscopy and gram negative bacteria in the lower respiratory tract were associated with ALI in univariate analyses. Subsequent multivariate analysis also controlled for % body surface area burns, infection, and inhalation severity. Elevated IL-10 and reduced IL-12p70 in bronchial washings were statistically significantly associated with ALI. Conclusions Independently of several factors including initial inhalational injury severity, infection, and extent of surface burns, high early levels of IL-10 and low levels of IL-12p70 in the central airways are associated with ALI in patients intubated after acute burn/inhalation injury. Lower airway secretions can be collected serially in critically ill burn/inhalation injury patients and may yield important clues to specific pathophysiologic pathways. PMID:23691180

  19. Lifespan method as a tool to study criticality in absorbing-state phase transitions

    NASA Astrophysics Data System (ADS)

    Mata, Angélica S.; Boguñá, Marian; Castellano, Claudio; Pastor-Satorras, Romualdo

    2015-05-01

    In a recent work, a new numerical method (the lifespan method) has been introduced to study the critical properties of epidemic processes on complex networks [M. Boguñá, C. Castellano, and R. Pastor-Satorras, Phys. Rev. Lett. 111, 068701 (2013), 10.1103/PhysRevLett.111.068701]. Here, we present a detailed analysis of the viability of this method for the study of the critical properties of generic absorbing-state phase transitions in lattices. Focusing on the well-understood case of the contact process, we develop a finite-size scaling theory to measure the critical point and its associated critical exponents. We show the validity of the method by studying numerically the contact process on a one-dimensional lattice and comparing the findings of the lifespan method with the standard quasistationary method. We find that the lifespan method gives results that are perfectly compatible with those of quasistationary simulations and with analytical results. Our observations confirm that the lifespan method is a fully legitimate tool for the study of the critical properties of absorbing phase transitions in regular lattices.

  20. Pedagogical Methods to Promote STEM Literacy with Case-Study

    NSDL National Science Digital Library

    Dharam Persaud-Sharma

    "Pedagogical Methods to Promote STEM Literacy with Case-Study" is a manuscript pertaining to the under-training of youths in America with regards to the STEM coalition of subjects. This manuscript proposes a 5-step culturally relevant teaching paradigm to improve education in these subjects, as well as retain and attract students to the fields. A case-study presenting the implementation of this paradigm is also included to show its effectiveness when implemented correctly.

  1. General practice fundholding: observations on prescribing patterns and costs using the defined daily dose method

    Microsoft Academic Search

    M Maxwell; D Heaney; J G Howie; S Noble

    1993-01-01

    OBJECTIVE--To compare prescribing patterns between a group of fundholding practices and a group of non-fundholding practices in north east Scotland using a method which provides more accurate statements about volumes prescribed than standard NHS statistics. DESIGN--The pharmacy practice division of the National Health Service in Scotland provided data for selected British National Formulary sections over two years. Each prescription issued

  2. Libraries in Online Elementary Schools: A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Hibbard, Laura; Franklin, Teresa

    2015-01-01

    School libraries serve an important role; however, elementary students who attend schools online typically do not have a school library. This study followed an online school's inaugural year in instituting a library. A mixed methods approach examined data from focus groups, interviews, surveys, library-use records and oral reading fluency scores.…

  3. An Innovative Method to Study Stokes' Law in the Laboratory

    ERIC Educational Resources Information Center

    Wadhwa, Ajay

    2008-01-01

    A new method is introduced to study the behaviour of the falling spherical ball in a viscous liquid using the well known Stokes' law. Experimental results are compared with those obtained by numerical calculations. Upper limits on the size and mass of the spherical balls of different materials used in the experiment are presented. (Contains 5…

  4. A SIMPLE METHOD FOR EVALUATING DATA FROM AN INTERLABORATORY STUDY

    EPA Science Inventory

    Large-scale laboratory-and method-performance studies involving more than about 30 laboratories may be evaluated by calculating the HORRAT ratio for each test sample (HORRAT=[experimentally found among-laboratories relative standard deviation] divided by [relative standard deviat...

  5. Study of New Graphical Method for Sportman Evaluation

    Microsoft Academic Search

    L. Dan Milici; Elena Rata; Mariana R. Milici

    The large majority of specialists on sport domain, after the undertaken studies, proposed varied solutions to improve this process and promoted modern methods and means. In this way, came into being some installations, equipments and computerized technologies that more contributed to the improvement of the training process development. The computing technique also integrated itself into the selection process and into

  6. ACID AEROSOL MEASUREMENT METHODS: STUDIES OF EXTRACTION AND ANALYTICAL EFFECTS

    EPA Science Inventory

    Following a major intercomparison of acid aerosol measurement methods, an additional study was held to investigate the sources of variability among labs. n addition, it was felt important to do this comparison with atmospheric aerosol. he first test was of spiked filters in tripl...

  7. ACI METHOD OF CONCRETE MIX DESIGN: A PARAMETRIC STUDY

    Microsoft Academic Search

    Z. Wadud; S. Ahmad

    Concrete mix design by the ACI method requires various material properties as the input. The effect of variation of these input parameters on mix proportions has been studied here, with reference to strength attainment in few cases. The sensitivity of the mix has been expressed by volume ratios of fine aggregate to coarse aggregate and cement to fine aggregate. It

  8. Medication use in European primary care patients with lower respiratory tract infection: an observational study.

    PubMed

    Hamoen, Marleen; Broekhuizen, Berna D L; Little, Paul; Melbye, Hasse; Coenen, Samuel; Goossens, Herman; Butler, Chris C; Francis, Nick A; Verheij, Theo J M

    2014-02-01

    BACKGROUND It is largely unknown what medication is used by patients with lower respiratory tract infection (LRTI). AIM To describe the use of self-medication and prescribed medication in adults presenting with LRTI in different European countries, and to relate self-medication to patient characteristics. DESIGN AND SETTING An observational study in 16 primary care networks in 12 European countries. METHOD A total of 2530 adult patients presenting with LRTI in 12 European countries filled in a diary on any medication used before and after a primary care consultation. Patient characteristics related to self-medication were determined by univariable and multivariable logistic regression analysis. RESULTS The frequency and types of medication used differed greatly between European countries. Overall, 55.4% self-medicated before consultation, and 21.5% after consultation, most frequently with paracetamol, antitussives, and mucolytics. Females, non-smokers, and patients with more severe symptoms used more self-medication. Patients who were not prescribed medication during the consultation self-medicated more often afterwards. Self-medication with antibiotics was relatively rare. CONCLUSION A considerable amount of medication, often with no proven efficacy, was used by adults presenting with LRTI in primary care. There were large differences between European countries. These findings should help develop patient information resources, international guidelines, and international legislation concerning the availability of over-the-counter medication, and can also support interventions against unwarranted variations in care. In addition, further research on the effects of symptomatic medication is needed. PMID:24567621

  9. Annual change in spirometric parameters among patients affected in Bhopal gas disaster: A retrospective observational study

    PubMed Central

    De, Sajal

    2013-01-01

    Background: The involvement of respiratory system due to inhalation of methyl isocyanate (MIC) during Bhopal gas disaster was particularly severe. We retrospectively evaluated the annual changes in spirometric parameters among those who were affected in this disaster (exposed survivors) and had respiratory symptoms. Materials and Methods: Spirometry reports of exposed survivors that were carried out in our institution were retrospectively reviewed and we identified 252 subjects who had performed spirometry at least twice with interval of more than one year. The annual changes in spirometric indices of them were calculated. Results: The average age of study population was 55.7 years and 72% were male. Annual decline of FEV1 ? 40 ml/yr was observed among 48% exposed survivors. The mean annual decline of FEV1 among symptomatic exposed survivors with initial normal spirometry was 91 ml (95% CI: 52 ml to 130 ml) and this was more than the patients with initial obstructive pattern. Among fifty four patients with initial normal spirometry, ten patients (18.5%) developed obstructive and two patients (5%) developed restrictive lung function abnormalities during follow up spirometry. Conclusion: The exposed survivors with chronic respiratory symptoms had accelerated decline in lung function and they are at higher risk of developing obstructive lung function. PMID:23741089

  10. Improvement of a retrieval method of the column-averaged dry air mole fractions of carbon dioxide and methane from Greenhouse gases Observing SATellite (GOSAT) observation

    NASA Astrophysics Data System (ADS)

    Yoshida, Y.; Eguchi, N.; Ota, Y.; Morino, I.; Uchino, O.; Watanabe, H.; Yokota, T.

    2010-12-01

    Column-averaged dry air mole fractions of carbon dioxide and methane (XCO2 and XCH4) are retrieved globally from the short-wavelength infrared spectrum data observed by the Greenhouse gases Observing SATellite (GOSAT). When we use only the carbon dioxide 1.6 ? m band or methane 1.67 ? m band in the retrievals, the retrieved XCO2 and XCH4 values show large variabilities (-35% to +15% from the average) due to aerosol and cloud influences. Equivalent optical path length changes due to cloud and aerosol have two contrary effects; the multiple-scattering of cloud and aerosol extends the equivalent optical path length, while the scattering event at high altitude shortens it. The former effect is obvious over the Sahara desert and its surroundings where the dust particles are rich, and the latter effect is spread over the tropics where the frequency of cirrus occurrence is high. Overestimated (underestimated) equivalent optical path length brings negative (positive) biases in the retrieved XCO2 and XCH4 values. In order to minimize these biases, pre-processed cloud screening criterion is optimized to detect and exclude relatively thin cirrus case, and the observed spectrum at the oxygen A-band (0.76 ? m) is utilized in the retrieval to correct the optical path modification. These improvements eliminate most of the largely deviated retrieval results and make the variabilities of the retrieved XCO2 and XCH4 smaller (-7% to +5% from the average). Data products retrieved with the improved method (GOSAT SWIR L2 V01.xx Products) are available to get via https://data.gosat.nies.go.jp.

  11. Prognostic value of alveolar volume in systolic heart failure: a prospective observational study

    PubMed Central

    2013-01-01

    Background Ventilatory impairment is known to occur in patients with heart failure (HF). Alveolar volume (VA) is measured by the dilution of an inert gas during a single breath-hold maneuver. Such measurement is sensitive to ventilatory disturbances. We conducted a prospective, observational study to establish the prognostic value of VA in systolic HF. Methods We studied 260 consecutive patients who were hospitalized for systolic HF. All patients were evaluated under stable clinical conditions, before hospital discharge. Lung function studies included spirometry and determination of the lung diffusing capacity for carbon monoxide (DLCO) by the single-breath method. We also measured the cardiothoracic ratio on frontal chest radiographs, and the circulating levels of N-terminal pro-hormone of B-type natriuretic peptide (NT-proBNP). The hazard ratio (HR) of death was estimated with Cox regression, and the percentiles of survival time with Laplace regression. For survival analysis, VA was categorized as 0.5, NT-proBNP, persistent atrial fibrillation, DLCO, COPD comorbidity, use of beta-blockers and angiotensin converting enzyme inhibitors, the HR decreased to 1.9 but remained statistically significant (p?=?0.039). Two percent of the patients with VA?

  12. Characterisation of sleep in intensive care using 24-hour polysomnography: an observational study

    PubMed Central

    2013-01-01

    Introduction Many intensive care patients experience sleep disruption potentially related to noise, light and treatment interventions. The purpose of this study was to characterise, in terms of quantity and quality, the sleep of intensive care patients, taking into account the impact of environmental factors. Methods This observational study was conducted in the adult ICU of a tertiary referral hospital in Australia, enrolling 57 patients. Polysomnography (PSG) was performed over a 24-hour period to assess the quantity (total sleep time: hh:mm) and quality (percentage per stage, duration of sleep episode) of patients' sleep while in ICU. Rechtschaffen and Kales criteria were used to categorise sleep. Interrater checks were performed. Sound pressure and illuminance levels and care events were simultaneously recorded. Patients reported on their sleep quality in ICU using the Richards Campbell Sleep Questionnaire and the Sleep in Intensive Care Questionnaire. Data were summarised using frequencies and proportions or measures of central tendency and dispersion as appropriate and Cohen's Kappa statistic was used for interrater reliability of the sleep data analysis. Results Patients' median total sleep time was 05:00 (IQR: 02:52 to 07:14). The majority of sleep was stage 1 and 2 (medians: 19 and 73%) with scant slow wave and REM sleep. The median duration of sleep without waking was 00:03. Sound levels were high (mean Leq 53.95 dB(A) during the day and 50.20 dB(A) at night) and illuminance levels were appropriate at night (median <2 lux) but low during the day (median: 74.20 lux). There was a median 1.7 care events/h. Patients' mean self-reported sleep quality was poor. Interrater reliability of sleep staging was highest for slow wave sleep and lowest for stage 1 sleep. Conclusions The quantity and quality of sleep in intensive care patients are poor and may be related to noise, critical illness itself and treatment events that disturb sleep. The study highlights the challenge of quantifying sleep in the critical care setting and the need for alternative methods of measuring sleep. The results suggest that a sound reduction program is required and other interventions to improve clinical practices to promote sleep in intensive care patients. Trial registration Australian New Zealand clinical trial registry (http://www.anzctr.org.au/): ACTRN12610000688088. PMID:23506782

  13. A study on the relationship of sexual satisfaction and common contraceptive methods employed by the couples

    PubMed Central

    Toorzani, Zahra Mehdizadeh; Zahraei, Roshanak Hasan; Ehsanpour, Soheila; Nasiri, Mahmood; Shahidi, Shahla; Soleimani, Bahram

    2010-01-01

    BACKGROUND: Sexual relationship is a basis for mental health and continuity of the healthy generation. Enjoying the healthy body and mind will cause the sexual relationships to run their normal course in life. One of the problems that couples are faced within their sexual relationships is the issue of employing family planning methods. Studies have revealed that contraceptive methods are in connection with the sexual function and health in different ways. This study was aimed to determine the mean and the relation of scores of sexual satisfaction of men and women with the common contraceptive methods. METHODS: This was a descriptive-correlative study. Samples included 280 individuals (140 couples) to use the common contraceptive methods including withdrawal method, tubal ligation in women, oral contraceptive method, condom, vasectomy, IUD and injection contraceptive method. Tools for gathering the data were Female Sexual Function Index (FSFI) and the questionnaire provided by Dr. Abdo on sexual satisfaction in men in 2004. The validity and reliability of these questionnaires were approved by researches conducted in worldwide and Iran. Descriptive and inferential statistic methods were applied in analyzing the data. RESULTS: The results suggested a significant statistic relation between scores of men’s sexual satisfaction and separate contraceptive methods (p = 0.001) whereas this relation was not observed between the women’s scores of sexual satisfaction and the contraceptive methods. CONCLUSIONS: According to the results of the present study, training family planning counselors in relation to choose suitable contraceptive method, in view of its probable effects on the couple’s sexual satisfaction, seems essential. PMID:21589773

  14. Local Predictability Studies and Time-Series Algorithms for Observed Chaotic Data

    NASA Astrophysics Data System (ADS)

    Kennel, Matthew Bochner

    1995-01-01

    Nonlinear chaotic dynamical systems produce irregular time series that do not yield understanding when viewed with traditional linear measures like the Fourier transform or linear correlation. Common practice now applies phase -space reconstruction on complicated data sets to attempt to find an analog to the original multi-variate dynamical system that generated the observed dataset. When good coordinates are used, chaotic data will appear predictable, in the short term. This dissertation demonstrates a state -of-the-art algorithm to find the minimum necessary embedding dimension given only the observed data and without a model, a crucial parameters in the reconstruction, and an upper bound on the complexity of the attractor. This algorithm also provides a means to unambiguously distinguish authentic low-dimensional chaotic data from colored noise and noisy periodicity, often a difficult problem when presented with realistically noisy or complicated experimental data. The author also demonstrates an alternative surrogate data method for that purpose. Even given a minimal global phase -space reconstruction, data may lie on a sub-manifold of lower dimensionality. The author gives an algorithm to find that integral-valued local manifold dimension, a dynamical invariant. A chaotic dynamical system is intrinsically unstable, which results in the eventual separation of initially neighboring over time, and thus the well-known loss of long-term predictability despite being fully deterministic in its evolution. The Lyapunov exponent is the quantity typically used in the field to quantify this instability, but because it is defined only in a long-time average, is less relevant to predictability than the local Lyapunov exponents, which unlike the single global exponent, vary substantially over the attractor. The dissertation explores general features of local Lyapunov exponents in chaotic systems. The author demonstrates a simple model using the local Lyapunov exponents and a large-scale cutoff that quantifies empirically observed growth of errors far better than heuristics based only on the global Lyapunov exponent; this model may explain at a more fundamental level error scaling found in atmospheric predictability studies done in the meteorological sciences. The last chapter shows preliminary results suggesting that the spatial behavior of fields from chaotic PDE's show surprising low-dimensionality.

  15. The BraveNet prospective observational study on integrative medicine treatment approaches for pain

    PubMed Central

    2013-01-01

    Background Chronic pain affects nearly 116 million American adults at an estimated cost of up to $635 billion annually and is the No. 1 condition for which patients seek care at integrative medicine clinics. In our Study on Integrative Medicine Treatment Approaches for Pain (SIMTAP), we observed the impact of an integrative approach on chronic pain and a number of other related patient-reported outcome measures. Methods Our prospective, non-randomized, open-label observational evaluation was conducted over six months, at nine clinical sites. Participants received a non-standardized, personalized, multimodal approach to chronic pain. Validated instruments for pain (severity and interference levels), quality of life, mood, stress, sleep, fatigue, sense of control, overall well-being, and work productivity were completed at baseline and at six, 12, and 24 weeks. Blood was collected at baseline and week 12 for analysis of high-sensitivity C-reactive protein and 25-hydroxyvitamin D levels. Repeated-measures analysis was performed on data to assess change from baseline at 24 weeks. Results Of 409 participants initially enrolled, 252 completed all follow-up visits during the 6 month evaluation. Participants were predominantly white (81%) and female (73%), with a mean age of 49.1 years (15.44) and an average of 8.0 (9.26) years of chronic pain. At baseline, 52% of patients reported symptoms consistent with depression. At 24 weeks, significantly decreased pain severity (?23%) and interference (?28%) were seen. Significant improvements in mood, stress, quality of life, fatigue, sleep and well-being were also observed. Mean 25-hydroxyvitamin D levels increased from 33.4 (17.05) ng/mL at baseline to 39.6 (16.68) ng/mL at week 12. Conclusions Among participants completing an integrative medicine program for chronic pain, significant improvements were seen in pain as well as other relevant patient-reported outcome measures. Trial Registration ClinicalTrials.gov, NCT01186341 PMID:23800144

  16. Study of Tectonic Tremor in Depth: Triggering Stress Observation and Model of the Triggering Mechanism

    NASA Astrophysics Data System (ADS)

    Wang, Tien-Huei

    Non-volcanic tremor (NVT) has been discovered in recent years due to advances in seismic instruments and increased density of seismic networks. The NVT is a special kind of seismic signal indicative of the physical conditions and the failure mechanism on the source on the fault where NVT occurs. The detection methods used and the sensitivity of them relies on the density, distance and instrumentation of the station network available. How accurately the tremor is identified in different regions varies greatly among different studies. Therefore, there has not been study that rigorously documents tectonic tremors in different regions under limited methods and data. Meanwhile, many incidences of NVTs are observed during or after small but significant strain change induced by teleseismic, regional or local earthquake. The understanding of the triggering mechanisms critical for tremor remains unclear. In addition, characteristics of the triggering of NVT in different regions are rarely compared because of the short time frame after the discovery of the triggered NVTs. We first explore tectonic tremor based on observations to learn about its triggering, frequency of occurrence, location and spectral characteristics. Then, we numerically model the triggering of instability on the estimated tremor-source, under assumptions fine-tuned according to previous studies (Thomas et al., 2009; Miyazawa et al., 2005; Hill, 2008; Ito, 2009; Rubinstein et al., 2007; Peng and Chao, 2008). The onset of the slip reveals that how and when the external loading triggers tremor. It also holds the information to the background stress conditions under which tremor source starts with. We observe and detect tremor in two regions: Anza and Cholame, along San Jacinto Fault (SJF) and San Andreas Fault (SAF) respectively. These two sections of the faults, relative to general fault zone on which general earthquakes occur, are considered transition zones where slip of slow rates occurs. Slip events including NVT occur on these sections have slower slip rates than that of the general earthquakes (Rubin, 2008; Ide, 2008). In Azna region, we use envelope and waveform cross-correlation to detect tremor. We investigate the stress required to trigger tremor and tremor spectrum using continuous broadband seismograms from 11 stations located near Anza, California. We examine 44 Mw?7.4 teleseismic events between 2001 and 2011, in addition to one regional earthquake of smaller-magnitude, the 2009 Mw 6.5 Gulf of California earthquake, because it induced extremely high strain at Anza. The result suggests that not only the amplitude of the induced strain, but also the period of the incoming surface wave, may control triggering of tremor near Anza. In addition, we find that the transient-shear stress (17--35 kPa) required to trigger tremor along the SJF at Anza is distinctly higher than what has been reported for the well-studied SAF (Gulihem et al. 2010). We model slip initiation using the analytical solution of rate-and-state friction. We verify the correctness of this method by comparing the results with that from the dynamic model, implemented using the Multi-Dimensional Spectral Boundary Integral Code (MDSBI) written by Eric M. Dunham from Sanford University. We find that the analytical result is consistent with that of the dynamic model. We set up a patch model with which the source stress and frictional conditions best resemble the current estimates of the tremor source. The frictional regime of this patch is rate-weakening. The initial normal and shear stress, and friction parameters are suggested by previous observations of tectonic tremors both in this and other studies (Brown et al., 2005; Shelly et al., 2006; Miyazawa, 2008; Ben-Zion, 2012). Our dynamic loading first consists of simple harmonic stress change with fixed periods, simplifying the transient stress history to resemble teleseismic earthquakes. We tested the period and amplitude of such periodic loading. We find that the period of the transient shear stress is less important relative to the amplitu

  17. Dietary patterns are associated with disease risk among participants in the women's health initiative observational study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coronary heart disease (CHD) is the leading cause of death in women. A nested case-control study tested whether dietary patterns predicted CHD events among 1224 participants in the Women’s Health Initiative-Observational Study (WHI-OS) with centrally confirmed CHD, fatal or nonfatal myocardial infar...

  18. Spanish ocean observation system. IEO core project: Studies on time series of oceanographic data

    Microsoft Academic Search

    L. Valdés; A. Lavín; M. L. Fernández de Puelles; M. Varela; R. Anadón; A. Miranda; J. Camiñas; J. Mas

    2002-01-01

    The Marine Environment Department of the Instituto Español de Oceanografía (IEO) is conducting several research projects based on the systematic and continuous study of the Ocean with observations made regularly over much long periods than a year-round and covering events in all seasons. The principal goal of the core project “Studies on time series of oceanographic data” is to understand

  19. A Naturalistic Observational Study of Informal Segregation: Seating Patterns in Lectures

    ERIC Educational Resources Information Center

    Koen, Jennifer; Durrheim, Kevin

    2010-01-01

    In spite of the removal of legislated racial segregation, a number of observational studies in South Africa and elsewhere have shown that "informal," nonlegislated segregation persists in spaces of everyday interaction. Most of these have been case studies of segregation at single sites. The authors seek to quantify segregation in a sample of…

  20. Sensitivity Analysis for Equivalence and Difference in an Observational Study of Neonatal Intensive

    E-print Network

    Rosenbaum, Paul R.

    the procedure to our study of the timing of discharges of premature babies from neonatal intensive care unitsSensitivity Analysis for Equivalence and Difference in an Observational Study of Neonatal Intensive Care Units Paul R. ROSENBAUM and Jeffrey H. SILBER In randomized experiments, it is sometimes important