Science.gov

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. 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.

  3. Overview of the epidemiology methods and applications: strengths and limitations of observational study designs.

    PubMed

    Colditz, Graham A

    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 in surgery and anesthesia showed greater gains than standard therapy when nonrandomized, controlled trials were evaluated compared with the gains reported in randomized, controlled trials. More recently, we and others have evaluated the impact of design in medical and surgical research, and concluded that the mean gain comparing new therapies to established therapies was biased by study design in nonrandomized trials (Colditz et al., 1989; Miller et al., 1989). Benson and Hartz (2000) conducted a study in which they focused only on studies reported after 1985. On the basis of 136 reports of 19 diverse treatments, Benson and Hartz concluded that in only 2 of the 19 analyses did the combined data from the observational studies lie outside the 95% confidence interval for the combined data from the randomized trials. A similar study drew only on data reported from 1991 to 1995, which showed remarkably similar results among observational studies and randomized, controlled trials (Concato et al., 2000). These more recent data suggest that advancing the study design and analytic methods may reduce bias in some evaluations of medical and public health interventions. Such methods apply not only to the original studies, but also to the approaches that are taken to quantitatively combine results by using meta-analytic approaches such as random effects meta-regression, Bayesian meta-analysis, and the like (Normand, 1999). By focusing attention on thorough data analysis, design issues can be understood and their impact or bias can be estimated, on average, and then ideally accounted for in the interpretation of data. Before discussing dietary data, let us first consider some of the more clearly delineated preventive exposures. Issues of study design have been addressed in terms of combining randomized trials and observational studies in evaluating preventive interventions such as Bacillus Calmette-Guerin vaccination (Colditz et al., 1994) and mammography screening (Desmissie et al., 1998). When one is interpreting the apparent heterogeneity in the results, it is important to step back and ask what is the relationship being evaluated under these different study designs? For example, a randomized, controlled trial uses the intention-to-treat analysis to preserve the merit of randomization. Such an analysis does not evaluate the exposure-disease relationship, but rather examines the impact of offering a new therapy versus an alternative therapy (regardless of adherence to the intervention, or control or placebo). On the other hand, a case-control study or a prospective cohort study will evaluate the impact of the screening test among those participants who were screened as compared with those who were never screened. In prevention studies, the design raises major issues of the timing of the exposure in the natural history of disease and also the adherence to therapy by healthy research volunteers. Case-control studies of preventive interventions such as screening mammography and prospective population-based studies of pap smears have capitalized on this variation in time since the last screen to evaluate the protective interval for a screening test (IARC Work Group, 1986). In contrast, a trial must choose a level of exposure, such as annual mammography screenings or colon screenings every 10 years with a colonoscopy, regardless of the evolving evidence on the duration of protection after a negative screening test. Continuing with the mammography example, a detailed study by Demissie and colleagues (1998) combined data from seven randomized trials and six case-control studies that investigated the association between participation in breast cancer screening programs and brea

  4. Study on pixel matching method of the multi-angle observation from airborne AMPR measurements

    NASA Astrophysics Data System (ADS)

    Hou, Weizhen; Qie, Lili; Li, Zhengqiang; Sun, Xiaobing; Hong, Jin; Chen, Xingfeng; Xu, Hua; Sun, Bin; Wang, Han

    2015-10-01

    For the along-track scanning mode, the same place along the ground track could be detected by the Advanced Multi-angular Polarized Radiometer (AMPR) with several different scanning angles from -55 to 55 degree, which provides a possible means to get the multi-angular detection for some nearby pixels. However, due to the ground sample spacing and spatial footprint of the detection, the different sizes of footprints cannot guarantee the spatial matching of some partly overlap pixels, which turn into a bottleneck for the effective use of the multi-angular detected information of AMPR to study the aerosol and surface polarized properties. Based on our definition and calculation of t he pixel coincidence rate for the multi-angular detection, an effective multi-angle observation's pixel matching method is presented to solve the spatial matching problem for airborne AMPR. Assuming the shape of AMPR's each pixel is an ellipse, and the major axis and minor axis depends on the flying attitude and each scanning angle. By the definition of coordinate system and origin of coordinate, the latitude and longitude could be transformed into the Euclidian distance, and the pixel coincidence rate of two nearby ellipses could be calculated. Via the traversal of each ground pixel, those pixels with high coincidence rate could be selected and merged, and with the further quality control of observation data, thus the ground pixels dataset with multi-angular detection could be obtained and analyzed, providing the support for the multi-angular and polarized retrieval algorithm research in t he next study.

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

    SciTech Connect

    Zhang, M.H.G. ); Luhmann, J.G. ); Kliore, A.J. )

    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.

  6. A study of some current methods of analysing observations of star forming regions

    E-print Network

    Palotti, S D D M L

    2004-01-01

    We present an evaluative study of some current methods utilized in the analysis of infrared (IR) observatinons of star-forming regions. A series of self-consistent radiative transfer models are constructed, with the outputs analysed using these methods to infer source properties such as dust temperature, mass, opacity function, and density distribution. Any discrepancies between the inferred and model quantities can be attributed to the analysis methods. The range of validity of most methods is smaller than expected, due to two effects: (1) limited applicability of the Rayleigh-Jeans limit except to very long wavelengths, and (2) significant errors in the isothermal approximation, even when temperature variations are less than 2 K over 90% of the region. Still, an accurate mean dust temperature can be found using a modified Wien's law. This temperature can yield dust masses to within 10-25% -- much better than masses inferred from the integrated luminosity. Using long wavelengths (greater than 1000 - 2000 mic...

  7. A study of some current methods of analysing observations of star forming regions

    E-print Network

    S. D. Doty; M. L. Palotti

    2004-02-25

    We present an evaluative study of some current methods utilized in the analysis of infrared (IR) observatinons of star-forming regions. A series of self-consistent radiative transfer models are constructed, with the outputs analysed using these methods to infer source properties such as dust temperature, mass, opacity function, and density distribution. Any discrepancies between the inferred and model quantities can be attributed to the analysis methods. The range of validity of most methods is smaller than expected, due to two effects: (1) limited applicability of the Rayleigh-Jeans limit except to very long wavelengths, and (2) significant errors in the isothermal approximation, even when temperature variations are less than 2 K over 90% of the region. Still, an accurate mean dust temperature can be found using a modified Wien's law. This temperature can yield dust masses to within 10-25% -- much better than masses inferred from the integrated luminosity. Using long wavelengths (greater than 1000 - 2000 microns), the opacity index can be determined from the far-IR spectrum to within 20%. Fitting the spectrum yields better results. The desnity distribution can be somewhat constrained by fitting the surface brightness, for well-resolved sources. Better results are found by fitting the flux spectrum with detailed models.

  8. 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.

  9. PARTICIPANT OBSERVATION IN A MULTIPLE·METHODS STUDY OF A RETIREMENT COMMUNITY: A RESEARCH NARRATIVE

    E-print Network

    Marshall, Victor W.

    1981-01-01

    G. Myerhoff and Andrei Simic (eds.) Life's Career­ Aging, Beverly Hills and London: Sage Publications. Rosenthal, Carolyn J., Victor W. Marshall, A.S. Macpherson and Susan B. French 1980 Nurses, Patients and Families. New York: Springer and Lon- don...·METHODS STUDY OF A RETIREMENT COMMUNITY: A RESEARCH NARRATIVE! Victor W. Marshall University ofToronto Mid-American Review of Sociology, 1981, Vol. VI, No. 2:29-44 In social science research, choice of methodology is con­ strained by the real or perceived biases...

  10. 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...

  11. Matching Methods for Observational Microarray Studies Ruth Heller 1,, Elisabetta Manduchi 2 and Dylan Small 1

    E-print Network

    Small, Dylan

    and Dylan Small 1 1 Department of Statistics, Wharton School, University of Pennsylvania, Philadelphia, PA: the first study consists of data from patients with two cancer subtypes, and the second study consists feasible. For example, the "conditions" may be cancer and non-cancer tissues, or different types of cancer

  12. Evaluation of Teaching Methods in Mass CPCR Training in Different Groups of the Society, an Observational Study

    PubMed Central

    Hasani, Hamed; Bahrami, Mojtaba; Malekpour, Abdorrasoul; Dehghani, Mohammadreza; Allahyary, Elaheh; Amini, Mitra; Abdorahimi, Mehdi; khani, Sara; Kalantari Meibodi, Mohammad; Kojuri, Javad

    2015-01-01

    Abstract To determine the efficacy of different methods of cardiopulmonary resuscitation (CPCR) training in 3 different groups of the society. In a prospective and observational study of 2000 individuals in 3 different groups including G1, G2, and G3 4 different protocols of CPCR training were applied and their efficacy was compared between the groups. Also, 12 months after the study course, 460 participants from 3 groups were asked to take apart in a theoretical and practical examination to evaluate the long-term efficacy of the 4 protocols. Among 2000 individuals took a parted in the study, 950 (47.5%) were G1, 600 (30%) were G2, and 450 (22.5%) were G3. G1 in 4 groups were 2.37 and 2.65 times more successful in pretest theoretical and 2.61 and 18.20 times more successful in practical examinations compared with G2 and G3 and gained highest improvement in CPCR skills. Other groups also showed significantly improved CPCR skills. Comparison of different methods of CPCR learning showed that the workshop using interactive lecture as well as human model, educational film, and reference CPCR book has the highest efficacy in all groups. This protocol of CPCR training showed more efficacy in long-term postdelayed evaluation. On the contrary, medical students had better long-term outcomes from the course. Although G1 and G2 obtained better results in learning CPCR skills, in G3 also the theoretical and practical knowledge were improved significantly. This course increased confidence for doing CPCR in all groups of the study. Considering that the most of the bystanders at emergency states are general population, training this group of the society and increasing their confidence about performing CPCR can be so effective and lifesaving at emergency states. (Clinical trial. Gov registration: NCT02120573) PMID:26020392

  13. Modern Asteroid Occultation Observing Methods

    NASA Astrophysics Data System (ADS)

    Lucas, G. A.

    2004-05-01

    This presentation reviews current working methods for asteroid occultations developed by the International Occultation Timing Association (IOTA). Reduc- tion of multiple tracks or "chords" observed during stellar occultations pro- vides valuable measures of the relative sizes and shapes of asteroids. Tradi- tionally, predictions for asteroid occultations were prepared by regional IOTA computors, distributed annually in "hard copy" format to IOTA subscrib- ers and in publications such as Sky & Telescope magazine and the annual RASC Observers Handbook. IOTA - like many other organizations - is now using worldwide internet services and e-mail to distribute frequently-updated pre- dictions based upon the latest astrometry. The IOTA web pages provide an easily accessible, centralized source of information on lunar and solar sys- tem occultation events. IOTA's web pages feature a variety of articles on current activities, plans for observing campaigns and expeditions, and "how to do it" information on the latest technology and techniques. The latest up- dated predictions for asteroid events are made available as they are pro- duced, providing more accurate observing tracks and efficient coordination of observers. The IOTA e-mail list provides a dynamic forum for the exchange of technical information and com-munication of observing plans in a timely man- ner. Individuals may now generate customized occultation predictions using the WinOccult software package. The author presents some examples of recent occultation events, showing the benefits of coordinated observations. Also described are some of the latest innovations, featuring low-cost video camera equipment, devices for time insertion based on Global Positioning Satellite (GPS) technology, and a new approach using unattended secondary field station equipment to multiply the number of tracks observed.

  14. 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...

  15. lecture notes for method Observation & Invention

    E-print Network

    Tollmar, Konrad

    lecture notes for method Observation & Invention Konrad Tollmar, Interactive Institute responses. Something I would like to refer to as the quality of the user experience. What is Observation&Invention? Observation and Invention is a creative tool, a design method, that embeds all three of these design

  16. Assessing observational studies of medical treatments

    PubMed Central

    Hartz, Arthur; Bentler, Suzanne; Charlton, Mary; Lanska, Douglas; Butani, Yogita; Soomro, G Mustafa; Benson, Kjell

    2005-01-01

    Background Previous studies have assessed the validity of the observational study design by comparing results of studies using this design to results from randomized controlled trials. The present study examined design features of observational studies that could have influenced these comparisons. Methods To find at least 4 observational studies that evaluated the same treatment, we reviewed meta-analyses comparing observational studies and randomized controlled trials for the assessment of medical treatments. Details critical for interpretation of these studies were abstracted and analyzed qualitatively. Results Individual articles reviewed included 61 observational studies that assessed 10 treatment comparisons evaluated in two studies comparing randomized controlled trials and observational studies. The majority of studies did not report the following information: details of primary and ancillary treatments, outcome definitions, length of follow-up, inclusion/exclusion criteria, patient characteristics relevant to prognosis or treatment response, or assessment of possible confounding. When information was reported, variations in treatment specifics, outcome definition or confounding were identified as possible causes of differences between observational studies and randomized controlled trials, and of heterogeneity in observational studies. Conclusion Reporting of observational studies of medical treatments was often inadequate to compare study designs or allow other meaningful interpretation of results. All observational studies should report details of treatment, outcome assessment, patient characteristics, and confounding assessment. PMID:16137327

  17. HARPS Observes the Earth Transiting the Sun — A Method to Study Exoplanet Atmospheres Using Precision Spectroscopy on Large Ground-based Telescopes

    NASA Astrophysics Data System (ADS)

    Yan, F.; Fosbury, R.; Petr-Gotzens, M.; Pallé, E.; Zhao, G.

    2015-09-01

    Exoplanetary transits offer the opportunity to measure the transmission of long, tangential pathlengths through their atmospheres. Since the fraction of the observed stellar light taking these paths is very small, transit photometric and spectrophotometric measurements of light curves require very high levels of measurement stability, favouring the use of intrinsically stable space telescopes. By studying the Rossiter-McLaughlin effect on the radial velocity of the transited star, pure, high-precision radial velocity measurements can be used to estimate the changes in planetary atmospheric transmission with wavelength: a promising method for future studies of small planets with very large ground-based telescopes since it removes the requirement for extreme photometric stability. This article describes a successful feasibility experiment using the HARPS instrument to measure reflected moonlight during the penumbral phases of a Lunar eclipse, effectively providing an observation of an Earth transit.

  18. Task-based evaluation of a 4D MAP-RBI-EM image reconstruction method for gated myocardial perfusion SPECT using a human observer study

    NASA Astrophysics Data System (ADS)

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M.; Tsui, Benjamin M. W.

    2015-09-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion abnormality. We concluded that the NMSE-NSDav trade-off was shown to agree with observer performance for the detection task of the regional motion abnormality, and the optimized 4D MAP-RBI-EM method with ADS corrections provides significant improvement compared to 3D FBP and 3D OS-EM with ADS corrections in detecting regional myocardial wall motion abnormali in 4D gated MP SPECT.

  19. Task-based evaluation of a 4D MAP-RBI-EM image reconstruction method for gated myocardial perfusion SPECT using a human observer study.

    PubMed

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M; Tsui, Benjamin M W

    2015-09-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion abnormality. We concluded that the NMSE-NSDav trade-off was shown to agree with observer performance for the detection task of the regional motion abnormality, and the optimized 4D MAP-RBI-EM method with ADS corrections provides significant improvement compared to 3D FBP and 3D OS-EM with ADS corrections in detecting regional myocardial wall motion abnormali in 4D gated MP SPECT. PMID:26301337

  20. 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.

  1. 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.

  2. 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

  3. Ways of learning: Observational studies versus experiments

    USGS Publications Warehouse

    Shaffer, T.L.; Johnson, D.H.

    2008-01-01

    Manipulative experimentation that features random assignment of treatments, replication, and controls is an effective way to determine causal relationships. Wildlife ecologists, however, often must take a more passive approach to investigating causality. Their observational studies lack one or more of the 3 cornerstones of experimentation: controls, randomization, and replication. Although an observational study can be analyzed similarly to an experiment, one is less certain that the presumed treatment actually caused the observed response. Because the investigator does not actively manipulate the system, the chance that something other than the treatment caused the observed results is increased. We reviewed observational studies and contrasted them with experiments and, to a lesser extent, sample surveys. We identified features that distinguish each method of learning and illustrate or discuss some complications that may arise when analyzing results of observational studies. Findings from observational studies are prone to bias. Investigators can reduce the chance of reaching erroneous conclusions by formulating a priori hypotheses that can be pursued multiple ways and by evaluating the sensitivity of study conclusions to biases of various magnitudes. In the end, however, professional judgment that considers all available evidence is necessary to render a decision regarding causality based on observational studies.

  4. Internal pilots for observational studies.

    PubMed

    Gurka, Matthew J; Coffey, Christopher S; Gurka, Kelly K

    2010-10-01

    Study planning often involves selecting an appropriate sample size. Power calculations require specifying an effect size and estimating "nuisance" parameters, e.g. the overall incidence of the outcome. For observational studies, an additional source of randomness must be estimated: the rate of the exposure. A poor estimate of any of these parameters will produce an erroneous sample size. Internal pilot (IP) designs reduce the risk of this error?-?leading to better resource utilization - by using revised estimates of the nuisance parameters at an interim stage to adjust the final sample size. In the clinical trials setting, where allocation to treatment groups is pre-determined, IP designs have been shown to achieve the targeted power without introducing substantial inflation of the type I error rate. It has not been demonstrated whether the same general conclusions hold in observational studies, where exposure-group membership cannot be controlled by the investigator. We extend the IP to observational settings. We demonstrate through simulations that implementing an IP, in which prevalence of the exposure can be re-estimated at an interim stage, helps ensure optimal power for observational research with little inflation of the type I error associated with the final data analysis. PMID:20857422

  5. ACCURACY OF DIETARY RECALL USING THE USDA 5-STEP MULTIPLE PASS METHOD IN A MULTI-ETHNIC POPULATION: AN OBSERVATIONAL VALIDATION STUDY.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because of the need to test methods of dietary assessment for accuracy, we tested the ability of an ethnically diverse population to recall food intake. We observed food intake for one day in African-American (AA) and Caucasian-American (CA) male (M) and female (F) subjects. They selected all meals ...

  6. Classical method of coherence estimation based on mutual wavelet-spectra of time variations of studied processes observed in the Earth atmosphere

    NASA Astrophysics Data System (ADS)

    Fahrutdinova, Antonina; Rizhov, Dmitriy; Magdeev, Konstantin

    In the present article the authors offer to conduct a research into influence exerted by solar effects (Wolf number) on time variations of average monthly values of the zonal wind, obtained in Kazan Federal University with the help of a meteoric radar complex KGU-M5 within the mesosphere - lower thermosphere during the period from 1978 to 2007. There exists a wide variety of signal processing methods that can be used to identify connection between two processes. A classical method of coherence calculation based on a mutual wavelet-spectrum has become widely used. Due to limited duration of the studied time series of dynamic parameters we have found coherent structures of time variations in solar activity (Wolf number) and zonal wind within the mesosphere-lower thermosphere for the scales of about 0.5, 1, 1.5, 2, 3, and 4-5 years. SCM values have been calculated for the most pronounced periodicities observed for scales of about 3 years during the period from 1986 to 1997. The average SCM value was equal to 0.75. Confidence interval of obtained SCM values was in the range of [0.54, 0.88] for the significance level As the atmosphere is a non-linear medium, this can lead to shifting and broadening of spectral components. In addition to the above mentioned periodicities (0.5 - 5 years), a wavelet spectrum calculated in the zonal wind field indicates possible presence of time periodicities in the range of 11-20 years.

  7. Evaluation of internal noise methods for Hotelling observer models

    SciTech Connect

    Zhang Yani; Pham, Binh T.; Eckstein, Miguel P.

    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.

  8. 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

  9. Surface studies of asteroids from earthbound observations

    NASA Astrophysics Data System (ADS)

    Schober, H. J.; Scaltriti, F.; Zappala, V.

    1980-04-01

    The angular diameter of minor planets under the best observation conditions of about one arcsec (seeing) at ground-based observatories usually is too small to be resolved for surface studies or diameter determinations with direct photographic or similar imaging methods. Nevertheless, the rough geometry and/or small-scale structures on the asteroid surfaces can be studied with light curve observations using high-precision photoelectric photometry and the fact that the rotation of an asteroid during a spin period is now determined for slightly more than 200 minor planets. For only a few selected asteroids (63 Ausonia, 88 Thisbe, 92 Undina, 110 Lydia, 118 Peitho, 128 Nemesis, 139 Juewa, 337 Devosa, and 599 Luisa) it is shown from details detected in the light curves, how observations of this type were carried out successfully. From the small scale features, rough linear extensions on the asteroid surface are obtained from differences in magnitude and time. Such observations will be more useful and important in the future with respect to the optimum selection of objects for a possible direct asteroid spacecraft mission.

  10. 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

  11. UFOs: Observations, Studies and Extrapolations

    E-print Network

    Baer, T; Barnes, M J; Bartmann, W; Bracco, C; Carlier, E; Cerutti, F; Dehning, B; Ducimetière, L; Ferrari, A; Ferro-Luzzi, M; Garrel, N; Gerardin, A; Goddard, B; Holzer, E B; Jackson, S; Jimenez, J M; Kain, V; Zimmermann, F; Lechner, A; Mertens, V; Misiowiec, M; Nebot Del Busto, E; Morón Ballester, R; Norderhaug Drosdal, L; Nordt, A; Papotti, G; Redaelli, S; Uythoven, J; Velghe, B; Vlachoudis, V; Wenninger, J; Zamantzas, C; Zerlauth, M; Fuster Martinez, N

    2012-01-01

    UFOs (“ Unidentified Falling Objects”) could be one of the major performance limitations for nominal LHC operation. Therefore, in 2011, the diagnostics for UFO events were significantly improved, dedicated experiments and measurements in the LHC and in the laboratory were made and complemented by FLUKA simulations and theoretical studies. The state of knowledge is summarized and extrapolations for LHC operation in 2012 and beyond are presented. Mitigation strategies are proposed and related tests and measures for 2012 are specified.

  12. An Alternative IRT Observed Score Equating Method. CRESST Report 751

    ERIC Educational Resources Information Center

    Kang, Taehoon; Chen, Troy T.

    2009-01-01

    In this report, an alternative item response theory (IRT) observed score equating method was newly developed. The proposed equating method was illustrated with two real data sets and the equating results were compared to those of traditional IRT true score and IRT observed score equating methods. Using three loss indices, the new method appeared…

  13. Comparing hormone therapy effects in two RCTs and two large observational studies that used similar methods for comprehensive data collection and outcome assessment

    PubMed Central

    Hartz, Arthur; He, Tao; Wallace, Robert; Powers, John

    2013-01-01

    Objectives Prospective observational studies (OSs) that collect adequate information about confounders can validly assess treatment consequences. However, what constitutes adequate information is unknown. This study investigated whether the extensive information collected by the Women's Health Initiative (WHI) in two OSs and two randomised controlled trials (RCTs) was adequate. Design Secondary analysis of WHI data. Cox regression was used to select from all baseline risk factors those that best predicted outcome. Cox regression that included these risk factors was used for two types of analyses: (1) comparing RCT and OS assessments of the effects of hormone therapy on outcome for participants with specific characteristics and (2) evaluating whether adjustment for measured confounders could eliminate outcome differences among datasets. Setting The WHI included more than 800 baseline risk factors and outcomes during a median follow-up of 8?years. Participants 151?870 postmenopausal women ages 50–79. Primary and secondary outcome measures Myocardial infarction and stroke. Results RCT and OS results differed for the association of hormone therapy with outcome after adjusting for confounding factors and stratifying on factors that were hypothesised to modulate the effects of hormone therapy (eg, age and time since menopause) or that empirically modulated the effects of hormone therapy in this dataset (eg, blood pressure, previous coronary revascularisation and private medical insurance). Some of the four WHI datasets had significantly worse outcomes than others even after adjusting for risk and stratifying by type of hormone therapy, for example, the risk-adjusted HR for myocardial infarction was 1.37 (p<0.0001) in an RCT placebo group compared with an OS group not taking hormone therapy. Conclusions Apparently the WHI did not collect sufficient information to give reliable assessments of treatment effects. If the WHI did not collect sufficient data, it is likely that few OSs collect sufficient information. PMID:23861441

  14. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: guidelines for reporting observational studies.

    PubMed

    von Elm, Erik; Altman, Douglas G; Egger, Matthias; Pocock, Stuart J; Gøtzsche, Peter C; Vandenbroucke, Jan P

    2014-12-01

    Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Initiative developed recommendations on what should be included in an accurate and complete report of an observational study. We defined the scope of the recommendations to cover three main study designs: cohort, case-control, and cross-sectional studies. We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklist of items. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBE contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklist of 22 items (the STROBE Statement) that relate to the title, abstract, introduction, methods, results, and discussion sections of articles. 18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies. A detailed Explanation and Elaboration document is published separately and is freely available on the Web sites of PLoS Medicine, Annals of Internal Medicine, and Epidemiology. We hope that the STROBE Statement will contribute to improving the quality of reporting of observational studies. PMID:25046131

  15. Predicting Plasma Glucose From Interstitial Glucose Observations Using Bayesian Methods

    PubMed Central

    Duun-Henriksen, Anne Katrine; Juhl, Rune; Schmidt, Signe; Nørgaard, Kirsten; Jørgensen, John Bagterp; Madsen, Henrik

    2014-01-01

    One way of constructing a control algorithm for an artificial pancreas is to identify a model capable of predicting plasma glucose (PG) from interstitial glucose (IG) observations. Stochastic differential equations (SDEs) make it possible to account both for the unknown influence of the continuous glucose monitor (CGM) and for unknown physiological influences. Combined with prior knowledge about the measurement devices, this approach can be used to obtain a robust predictive model. A stochastic-differential-equation-based gray box (SDE-GB) model is formulated on the basis of an identifiable physiological model of the glucoregulatory system for type 1 diabetes mellitus (T1DM) patients. A Bayesian method is used to estimate robust parameters from clinical data. The models are then used to predict PG from IG observations from 2 separate study occasions on the same patient. First, all statistically significant diffusion terms of the model are identified using likelihood ratio tests, yielding inclusion of ?Isc, ?Gp, and ?Gsc. Second, estimates using maximum likelihood are obtained, but prediction capability is poor. Finally a Bayesian method is implemented. Using this method the identified models are able to predict PG using only IG observations. These predictions are assessed visually. We are also able to validate these estimates on a separate data set from the same patient. This study shows that SDE-GBs and a Bayesian method can be used to identify a reliable model for prediction of PG using IG observations obtained with a CGM. The model could eventually be used in an artificial pancreas. PMID:24876584

  16. LONGITUDINAL COHORT METHODS STUDIES

    EPA Science Inventory

    Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Exposure classification for occupational studies is relatively easy compared to predicting residential childhood exposures. Recent NHEXAS (Maryland) study articl...

  17. Do the methods used to analyse missing data really matter? An examination of data from an observational study of Intermediate Care patients

    PubMed Central

    2012-01-01

    Background Missing data is a common statistical problem in healthcare datasets from populations of older people. Some argue that arbitrarily assuming the mechanism responsible for the missingness and therefore the method for dealing with this missingness is not the best option—but is this always true? This paper explores what happens when extra information that suggests that a particular mechanism is responsible for missing data is disregarded and methods for dealing with the missing data are chosen arbitrarily. Regression models based on 2,533 intermediate care (IC) patients from the largest evaluation of IC done and published in the UK to date were used to explain variation in costs, EQ-5D and Barthel index. Three methods for dealing with missingness were utilised, each assuming a different mechanism as being responsible for the missing data: complete case analysis (assuming missing completely at random—MCAR), multiple imputation (assuming missing at random—MAR) and Heckman selection model (assuming missing not at random—MNAR). Differences in results were gauged by examining the signs of coefficients as well as the sizes of both coefficients and associated standard errors. Results Extra information strongly suggested that missing cost data were MCAR. The results show that MCAR and MAR-based methods yielded similar results with sizes of most coefficients and standard errors differing by less than 3.4% while those based on MNAR-methods were statistically different (up to 730% bigger). Significant variables in all regression models also had the same direction of influence on costs. All three mechanisms of missingness were shown to be potential causes of the missing EQ-5D and Barthel data. The method chosen to deal with missing data did not seem to have any significant effect on the results for these data as they led to broadly similar conclusions with sizes of coefficients and standard errors differing by less than 54% and 322%, respectively. Conclusions Arbitrary selection of methods to deal with missing data should be avoided. Using extra information gathered during the data collection exercise about the cause of missingness to guide this selection would be more appropriate. PMID:22738344

  18. 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.

  19. A new method of ARGO buoys system observation data interpolation

    NASA Astrophysics Data System (ADS)

    Zakharova, Natalia; Agoshkov, Valery; Parmuzin, Eugene

    2013-04-01

    Study and solution of geophysical hydrodynamics problems are based on experimental and observation data from different sources. Despite large amount of observation data, availability of them often remains insufficient because data are provided on sets of irregular points and during the asynchronous moments of time. In this work a new method of temperature fields creation on regular grids according to observation data is offered taking into account a transfer by their currents. By means of this method it is possible to receive "pseudo-observations" for the required moment of time and, thereby, to solve a problem of an asynchronism of geophysical information. The results of numerical experiments on the World Ocean area within ARGO buoys system data are given. This study was supported by the Russian Foundation for Basic Research (project 11-01-12046, 12-05-00469) and by the Russian Federal target Program "Research and educational human resources for innovative Russia" (project 8219) for 2009-2013 and the Federal target program "Researches and development in priority fields of scientific and technological complex of Russia for 2007-2013" (project 11.519.11.1005) and the Ministry of education and science of Russia, project 14.A18.21.1901. References 1. Zakharova N.B., Agoshkov V.I., Parmuzin E.I., The new method of ARGO buoys system observation data interpolation. Russian Journal of Numerical Analysis and Mathematical Modelling. Vol. 28, Issue 1, 2013. 2. Agoshkov V.I., Zakharova N.B., The creation of piecewise - harmonic interpolation on spherical surfaces. Russian Journal of Numerical Analysis and Mathematical Modelling. Vol. 27, Issue 6, 2012. 3. Zakharova N.B., Lebedev S.A., Interpolation of on-line data of the ARGO buoys system for data assimilation in the World ocean circulation model. Actual problems in remote sensing of the Earth from space: Principal physics, physical methods and technologies for monitoring of environment, of potentially dangerous occurrences and objects. The proceedings. Vol. 7. No. 4. 2010. (In russian)

  20. Attributing Effects to Treatment in Matched Observational Studies

    E-print Network

    George, Edward I.

    Attributing Effects to Treatment in Matched Observational Studies Paul R. Rosenbaum An effect. Extending earlier results on attributable effects in unmatched groups, a method of exact randomization-crossover study of alcohol as a cause of injury, a cohort study of women who gave birth at home, and a study

  1. Can we observe changes in mRNA “state”? Overview of methods to study mRNA interactions with regulatory proteins relevant in cancer related processes

    PubMed Central

    Zurla, C.; Jung, J.; Santangelo, P. J.

    2015-01-01

    RNA binding proteins (RBP) regulate the editing, localization, stabilization, translation, and degradation of ribonucleic acids (RNA) through their interactions with specific cis-acting elements within target RNAs. Post-transcriptional regulatory mechanisms are directly involved in the control of the immune response and stress response and their alterations play a crucial role in cancer related processes. In this review, we discuss mRNAs and RNA binding proteins relevant to tumorigenesis, current methodologies for detecting RNA interactions, and last, we describe a novel method to detect such interactions, which combines peptide modified, RNA imaging probes (FMTRIPs) with proximity ligation (PLA) and rolling circle amplification (RCA). This assay detects native RNA in a sequence specific and single RNA sensitive manner, and PLA allows for the quantification and localization of protein–mRNA interactions with single-interaction sensitivity in situ. PMID:26605378

  2. 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...

  3. Observing Protein & Energy Nutrition (OPEN) Study

    Cancer.gov

    The Observing Protein and Energy Nutrition (OPEN) Study was designed to assess dietary measurement error by comparing results from self-reported dietary intake data with four dietary biomarkers: doubly labeled water and urinary nitrogen, sodium, and potassium.

  4. 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".

  5. Embedding clinical interventions into observational studies.

    PubMed

    Newman, Anne B; Avilés-Santa, M Larissa; Anderson, Garnet; Heiss, Gerardo; Howard, Wm James; Krucoff, Mitchell; Kuller, Lewis H; Lewis, Cora E; Robinson, Jennifer G; Taylor, Herman; Treviño, Roberto P; Weintraub, William

    2016-01-01

    Novel approaches to observational studies and clinical trials could improve the cost-effectiveness and speed of translation of research. Hybrid designs that combine elements of clinical trials with observational registries or cohort studies should be considered as part of a long-term strategy to transform clinical trials and epidemiology, adapting to the opportunities of big data and the challenges of constrained budgets. Important considerations include study aims, timing, breadth and depth of the existing infrastructure that can be leveraged, participant burden, likely participation rate and available sample size in the cohort, required sample size for the trial, and investigator expertise. Community engagement and stakeholder (including study participants) support are essential for these efforts to succeed. PMID:26611435

  6. Observational Studies of Transiting Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Southworth, J.

    2015-07-01

    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 characterization 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.

  7. 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

  8. Observations of Bacterial Behavior during Infection Using the ARGOS Method

    NASA Astrophysics Data System (ADS)

    Charest, A. J.; Algarni, S.; Iannacchione, G. S.

    2015-03-01

    This research employed the Area Recorded Generalized Optical Scattering (ARGOS) approach which allowed for the observation of bacterial changes in terms of individual particles and population dynamics in real time. This new approach allows for an aqueous environment to be manipulated while conducting time-specific measurements over an indefinite amount of time. This current study provides a more time-specific method in which the bacteria remained within the initial conditions and allows for more time precision than provided by analyzing concentrations of plaque-forming units (PFU). This study involved the bacteria (F-amp) during infection by bacteriophage (MS2). The relative total intensity allows for detailed measurements of the bacteria population over time. The bacteria characteristics were also evaluated such as the root mean square image difference (at specific wavevectors), fractal dimension and effective radius. The growth rate of the infected bacteria occurred at a rate higher than the uninfected bacteria similarly, the death rates were also higher for the infected bacteria than the uninfected bacteria. The present study indicates that bacteria may react to infection by increasing the rate of population growth.

  9. Ozone Lidar Observations for Air Quality Studies

    NASA Technical Reports Server (NTRS)

    Wang, Lihua; Newchurch, Mike; Kuang, Shi; Burris, John F.; Huang, Guanyu; Pour-Biazar, Arastoo; Koshak, William; Follette-Cook, Melanie B.; Pickering, Kenneth E.; McGee, Thomas J.; Sullivan, John T.; Langford, Andrew O.; Senff, Christoph J.; Alvarez, Raul; Eloranta, Edwin

    2015-01-01

    Tropospheric ozone lidars are well suited to measuring the high spatio-temporal variability of this important trace gas. Furthermore, lidar measurements in conjunction with balloon soundings, aircraft, and satellite observations provide substantial information about a variety of atmospheric chemical and physical processes. Examples of processes elucidated by ozone-lidar measurements are presented, and modeling studies using WRF-Chem, RAQMS, and DALES/LES models illustrate our current understanding and shortcomings of these processes.

  10. Observations on variational and projector Monte Carlo methods

    NASA Astrophysics Data System (ADS)

    Umrigar, C. J.

    2015-10-01

    Variational Monte Carlo and various projector Monte Carlo (PMC) methods are presented in a unified manner. Similarities and differences between the methods and choices made in designing the methods are discussed. Both methods where the Monte Carlo walk is performed in a discrete space and methods where it is performed in a continuous space are considered. It is pointed out that the usual prescription for importance sampling may not be advantageous depending on the particular quantum Monte Carlo method used and the observables of interest, so alternate prescriptions are presented. The nature of the sign problem is discussed for various versions of PMC methods. A prescription for an exact PMC method in real space, i.e., a method that does not make a fixed-node or similar approximation and does not have a finite basis error, is presented. This method is likely to be practical for systems with a small number of electrons. Approximate PMC methods that are applicable to larger systems and go beyond the fixed-node approximation are also discussed.

  11. The Behavior Observation Instrument: a method of direct observation for program evaluation.

    PubMed Central

    Alevizos, P; DeRisi, W; Liberman, R; Eckman, T; Callahan, E

    1978-01-01

    The background and development of a multicategory direct observation system, the Behavior Observation Instrument (BOI), is described. This time-sampling procedure for recording the behavior of persons is demonstrated in several treatment settings and the results applied to issues of program evaluation. Elements that have prevented direct observation from being widely adopted, such as costs, manpower, and training requirements, are systematically analyzed. A basic psychometric analysis of the instrument is used to determine optimum frequency and duration of observation intervals as well as observer agreement. The results imply that direct observation methods, once assumed by some to belong to the special province of the single-subject design, can be used to assess the effects of programs on groups of psychiatric clients in an efficient and economic manner. PMID:97258

  12. 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.

  13. 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.

  14. 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.

  15. Using Observational Methods to Research the Student Experience

    ERIC Educational Resources Information Center

    Cotton, Debby R. E.; Stokes, Alison; Cotton, Peter A.

    2010-01-01

    Much pedagogic research undertaken in geography and other disciplines relies on post-hoc methods such as surveys or interviews to investigate the student experience of higher education (often based on self-reports of behaviour). However, observation of students provides a far more direct route to obtain information about their behaviour, and there…

  16. Advanced Earth Observation System Instrumentation Study (aeosis)

    NASA Technical Reports Server (NTRS)

    White, R.; Grant, F.; Malchow, H.; Walker, B.

    1975-01-01

    Various types of measurements were studied for estimating the orbit and/or attitude of an Earth Observation Satellite. An investigation was made into the use of known ground targets in the earth sensor imagery, in combination with onboard star sightings and/or range and range rate measurements by ground tracking stations or tracking satellites (TDRSS), to estimate satellite attitude, orbital ephemeris, and gyro bias drift. Generalized measurement equations were derived for star measurements with a particular type of star tracker, and for landmark measurements with a multispectral scanner being proposed for an advanced Earth Observation Satellite. The use of infra-red horizon measurements to estimate the attitude and gyro bias drift of a geosynchronous satellite was explored.

  17. Globally Gridded Satellite observations for climate studies

    USGS Publications Warehouse

    Knapp, K.R.; Ansari, S.; Bain, C.L.; Bourassa, M.A.; Dickinson, M.J.; Funk, C.; Helms, C.N.; Hennon, C.C.; Holmes, C.D.; Huffman, G.J.; Kossin, J.P.; Lee, H.-T.; Loew, A.; Magnusdottir, G.

    2011-01-01

    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 that no central archive of geostationary data for all international satellites exists, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multisatellite climate studies. The International Satellite Cloud Climatology Project (ISCCP) set the stage for overcoming these issues by archiving a subset of the full-resolution geostationary data at ~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 Network Common Data Format (netCDF) using standards that permit a wide variety of tools and libraries to process the data quickly and easily. 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.

  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. 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.

  20. A method for observing gas evolution during plastic laminate cure

    NASA Technical Reports Server (NTRS)

    Nicholls, A. H.

    1969-01-01

    Polyimide, phenolic, and other resins which develop volatiles during laminating or molding cure are studied using optimum cure cycles. The specimen is placed on a platen and sealed in a plastic bag, then heated and observed for gas evolution using a binocular microscope. A cover plate is added to sumulate an autoclave.

  1. Issues of reporting in observational studies in veterinary medicine.

    PubMed

    Sargeant, Jan M; O'Connor, Annette M

    2014-02-15

    Observational studies are common in veterinary medicine; the results may be used to inform decision-making, future research, or as inputs to systematic reviews or risk assessment. To be of use, the results must be published, all of the outcomes that were assessed must be included in the publication, and the research (methods and results) must be reported in sufficient detail that the reader can evaluate the internal and external validity. In human healthcare, concerns about the completeness of reporting - and evidence that poor reporting is associated with study results - have led to the creation of reporting guidelines; these include the STROBE statement for observational studies. There is evidence from a limited body of research that there also are reporting inadequacies in veterinary observational studies. There are differences between human and veterinary observational studies that might be relevant to recommendations for reporting. Such differences include: the use of observational studies in animal populations for simultaneously estimating disease frequency and risk-factor identification; the distinction between the animal owners who consent to participate and the animals that are the study subjects; and the complexity of organizational levels inherent in animal research (in particular, for studies in livestock species). In veterinary medicine, it is common to have clustering within outcomes (due to animal grouping) and clustering of predictor variables. We argue that there is a compelling need for the scientific community involved in veterinary observational studies to use the STROBE statement, use an amended version of STROBE, or to develop and use reporting guidelines that are specific to veterinary medicine to improve reporting of these studies. PMID:24139690

  2. 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)…

  3. A design method for unknown input observer for non-minimum phase systems

    NASA Astrophysics Data System (ADS)

    Yamada, Kou; Kobayashi, Masahiko

    2007-12-01

    In this paper, we examine a design method for unknown input observers for non-minimum phase systems. The unknown input observer has been used to estimate the state variable of the plant in the presence of unknown input. In addition the unknown input observer is applied to the systems with disturbance inputs or unknown varying parameters. Initially, the unknown input observer is examined by Kudva, Viswanadham and Ramakrishna. According to past studies, the unknown input observer for the plant (A,B,C,0) can be designed if and only if following 2 expressions hold true: (1) rankCB= rankB and (2) the plant (A,B,C,0) has no invariant zero in the closed right half plane. Many papers have been considered to design unknown input observers, even if above mentioned 2 expressions are not satisfied. In this paper, we propose a new design method of unknown input observers for non-minimum phase plants.

  4. Age estimation in forensic anthropology: quantification of observer error in phase versus component-based methods.

    PubMed

    Shirley, Natalie R; Ramirez Montes, Paula Andrea

    2015-01-01

    The purpose of this study was to assess observer error in phase versus component-based scoring systems used to develop age estimation methods in forensic anthropology. A method preferred by forensic anthropologists in the AAFS was selected for this evaluation (the Suchey-Brooks method for the pubic symphysis). The Suchey-Brooks descriptions were used to develop a corresponding component-based scoring system for comparison. Several commonly used reliability statistics (kappa, weighted kappa, and the intraclass correlation coefficient) were calculated to assess observer agreement between two observers and to evaluate the efficacy of each of these statistics for this study. The linear weighted kappa was determined to be the most suitable measure of observer agreement. The results show that a component-based system offers the possibility for more objective scoring than a phase system as long as the coding possibilities for each trait do not exceed three states of expression, each with as little overlap as possible. PMID:25389078

  5. A double-observer method to estimate detection rate during aerial waterfowl surveys

    USGS Publications Warehouse

    Koneff, M.D.; Royle, J. Andrew; Otto, M.C.; Wortham, J.S.; Bidwell, J.K.

    2008-01-01

    We evaluated double-observer methods for aerial surveys as a means to adjust counts of waterfowl for incomplete detection. We conducted our study in eastern Canada and the northeast United States utilizing 3 aerial-survey crews flying 3 different types of fixed-wing aircraft. We reconciled counts of front- and rear-seat observers immediately following an observation by the rear-seat observer (i.e., on-the-fly reconciliation). We evaluated 6 a priori models containing a combination of several factors thought to influence detection probability including observer, seat position, aircraft type, and group size. We analyzed data for American black ducks (Anas rubripes) and mallards (A. platyrhynchos), which are among the most abundant duck species in this region. The best-supported model for both black ducks and mallards included observer effects. Sample sizes of black ducks were sufficient to estimate observer-specific detection rates for each crew. Estimated detection rates for black ducks were 0.62 (SE = 0.10), 0.63 (SE = 0.06), and 0.74 (SE = 0.07) for pilot-observers, 0.61 (SE = 0.08), 0.62 (SE = 0.06), and 0.81 (SE = 0.07) for other front-seat observers, and 0.43 (SE = 0.05), 0.58 (SE = 0.06), and 0.73 (SE = 0.04) for rear-seat observers. For mallards, sample sizes were adequate to generate stable maximum-likelihood estimates of observer-specific detection rates for only one aerial crew. Estimated observer-specific detection rates for that crew were 0.84 (SE = 0.04) for the pilot-observer, 0.74 (SE = 0.05) for the other front-seat observer, and 0.47 (SE = 0.03) for the rear-seat observer. Estimated observer detection rates were confounded by the position of the seat occupied by an observer, because observers did not switch seats, and by land-cover because vegetation and landform varied among crew areas. Double-observer methods with on-the-fly reconciliation, although not without challenges, offer one viable option to account for detection bias in aerial waterfowl surveys where birds are distributed at low density in remote areas that are inaccessible by ground crews. Double-observer methods, however, estimate only detection rate of animals that are potentially observable given the survey method applied. Auxiliary data and methods must be considered to estimate overall detection rate.

  6. Century Scale Evaporation Trend: An Observational Study

    NASA Technical Reports Server (NTRS)

    Bounoui, Lahouari

    2012-01-01

    Several climate models with different complexity indicate that under increased CO2 forcing, runoff would increase faster than precipitation overland. However, observations over large U.S watersheds indicate otherwise. This inconsistency between models and observations suggests that there may be important feedbacks between climate and land surface unaccounted for in the present generation of models. We have analyzed century-scale observed annual runoff and precipitation time-series over several United States Geological Survey hydrological units covering large forested regions of the Eastern United States not affected by irrigation. Both time-series exhibit a positive long-term trend; however, in contrast to model results, these historic data records show that the rate of precipitation increases at roughly double the rate of runoff increase. We considered several hydrological processes to close the water budget and found that none of these processes acting alone could account for the total water excess generated by the observed difference between precipitation and runoff. We conclude that evaporation has increased over the period of observations and show that the increasing trend in precipitation minus runoff is correlated to observed increase in vegetation density based on the longest available global satellite record. The increase in vegetation density has important implications for climate; it slows but does not alleviate the projected warming associated with greenhouse gases emission.

  7. 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.

  8. 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.

  9. Evaluation of Inversion Methods Applied to Ionospheric ro Observations

    NASA Astrophysics Data System (ADS)

    Rios Caceres, Arq. Estela Alejandra; Rios, Victor Hugo; Guyot, Elia

    The new technique of radio-occultation can be used to study the Earth's ionosphere. The retrieval processes of ionospheric profiling from radio occultation observations usually assume spherical symmetry of electron density distribution at the locality of occultation and use the Abel integral transform to invert the measured total electron content (TEC) values. This pa-per presents a set of ionospheric profiles obtained from SAC-C satellite with the Abel inversion technique. The effects of the ionosphere on the GPS signal during occultation, such as bending and scintillation, are examined. Electron density profiles are obtained using the Abel inversion technique. Ionospheric radio occultations are validated using vertical profiles of electron con-centration from inverted ionograms , obtained from ionosonde sounding in the vicinity of the occultation. Results indicate that the Abel transform works well in the mid-latitudes during the daytime, but is less accurate during the night-time.

  10. 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.

  11. Advanced Earth Observation System Instrumentation Study (AEOSIS)

    NASA Technical Reports Server (NTRS)

    Var, R. E.

    1976-01-01

    The feasibility, practicality, and cost are investigated for establishing a national system or grid of artificial landmarks suitable for automated (near real time) recognition in the multispectral scanner imagery data from an earth observation satellite (EOS). The intended use of such landmarks, for orbit determination and improved mapping accuracy is reviewed. The desirability of using xenon searchlight landmarks for this purpose is explored theoretically and by means of experimental results obtained with LANDSAT 1 and LANDSAT 2. These results are used, in conjunction with the demonstrated efficiency of an automated detection scheme, to determine the size and cost of a xenon searchlight that would be suitable for an EOS Searchlight Landmark Station (SLS), and to facilitate the development of a conceptual design for an automated and environmentally protected EOS SLS.

  12. Estimation of nonfluctuating reservoir inflow from water level observations using methods based on flow continuity

    NASA Astrophysics Data System (ADS)

    Deng, Chao; Liu, Pan; Guo, Shenglian; Wang, Hao; Wang, Dingbao

    2015-10-01

    The accurate estimation of "true" reservoir inflow is important for hydrological forecasting and efficient operation of reservoirs. However, reservoir inflow estimated using the conventional simple water balance method is not always accurate because the estimation is very sensitive to errors in reservoir water level observations and uncertainty in the stage-storage relationship. An analytical method (AM) and a method using the ensemble Kalman filter (EnKF) are proposed to determine nonfluctuating reservoir inflow based on the concept of inflow continuity; that is, that inflow should not change much within a short time period. The AM is developed based on the simultaneous minimization of both the estimated reservoir water level error and the inflow variation. The EnKF, which is built on state equations (inflow continuity and water balance equations) and an observation equation (the reservoir stage-storage relationship), is used to update inflow states by assimilating water level observations. The two proposed methods are evaluated using a synthetic experiment with various conditions including water level observation error, reservoir stage-storage relationship error, and the influence of water surface slope. The AM outperforms the EnKF under all conditions. Case studies of the Gaobazhou and Danjiangkou Reservoirs in China demonstrate that both of the proposed methods can derive an hourly inflow without fluctuations. The results indicate that the AM and the EnKF method can improve reservoir inflow estimation compared with conventional methods.

  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. 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.

  15. 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...

  16. 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

  17. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 21, METHOD 611--HALOETHERS

    EPA Science Inventory

    Described herein are the experimental design and the results of an interlaboratory study of an analytical method to detect haloethers in water. The method, EPA Method 611 - Haloethers, consisted of a liquid/liquid extraction using methylene chloride, an evaporation step using Kud...

  18. The joint observation and study project for slowly rotating asteroids

    NASA Astrophysics Data System (ADS)

    Wang, Xiaobin; Muninonen, karri; Han, Xianming L.; Wang, Yibo

    2015-08-01

    The study for the spin rates and shapes of asteroids provides us important information to understand asteroids' structure and their physical processes. For example, a single Maxwellian distribution of the spin rates of larger asteroids (e.g. larger than 50km in diameter) reflects they had undergone collison history; a more dispersed distribution of smaller asteroids may be associated with the affect of radiation pressure torques( Pravec& Harris2000). Therefore, larger samples of spin parameters are needed for understanding deeply the evolution of asteroids. Meanwhile, some special subsets of asteroids, such as the slow rotators which probably represent a different physical process for asteroids, can open other windows to understand asteroids. Here we focus on a subset of larger asteroids with spin rates around 1 or 0.5 revolution per day. For these asteroids, the same rotational phases are observed repeatly by a telescope in different time. Under such cases, some ambigous spin periods are guessed, and it is impossible to determine their shapes. For determining the accurate spin parameters and shapes of these asteroids, a collaboration among several countries was established in 2014. Till now, the joint observations for a few of slow rotators have been made by several different telescopes distributed in China, USA and Chile. As samples, here we present new jiont observations in 2014 and analysis results for asteroids (346) Hermentaria and (168) Sibylla.Considering reasonable shapes of asteroids, the spin parameters of the two asteroids are analyzed carefully. Firstly, the procedure of analysis involves the MCMC method to find the initial spin parameters, which is based on a triaxial ellipsoid shape and a Lommel-Seeliger surface scattering law(Muinonen et al.2014). Then, the fine spin parameters accompanying with uncertainties and convex shapes of the asteroids are derived using the light curve inversion method(Kaasalainen et al 2002) and virtual photometric method(wang2012).

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    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, that 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, ? 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 that have undergone a core collapse during their evolution. We find that the results of our method are in agreement with N-body and Monte Carlo studies for the majority of clusters. We conclude that our method is able to find reliable posteriors for the determined initial mass and half-mass radius for observed star clusters, and thus forms an suitable starting point for modelling an observed cluster's evolution.

  20. Detecting Groupthink: Methods for Observing the Illusion of Unanimity.

    ERIC Educational Resources Information Center

    Cline, Rebecca J. Welch

    1990-01-01

    Reconceptualizes groupthink symptoms as observable group interaction patterns. Proposes two coding systems for detecting the illusion of unanimity symptom, detecting both degree of unanimity and degree of the illusory versus substantive nature of that unanimity. (SR)

  1. How safe do teenagers behave on Facebook? An observational study.

    PubMed

    Vanderhoven, Ellen; Schellens, Tammy; Valcke, Martin; Raes, Annelies

    2014-01-01

    The substantial use of social network sites by teenagers has raised concerns about privacy and security. Previous research about behavior on social network sites was mostly based on surveys and interviews. Observational research overcomes problems inherent to this research method, for example social desirability. However, existing observational research mostly focuses on public profiles of young adults. Therefore, the current observation-study includes 1050 public and non-public Facebook-profiles of teenagers (13-18) to investigate (1) what kind of information teenagers post on their profile, (2) to what extent they protect this information using privacy-settings and (3) how much risky information they have on their profile. It was found that young people mostly post pictures, interests and some basic personal information on their profile. Some of them manage their privacy-settings as such that this information is reserved for friends' eyes only, but a lot of information is accessible on the friends-of-friends' pages. Although general risk scores are rather low, more detailed analyses show that teenagers nevertheless post a significant amount of risky information. Moreover, older teenagers and girls post more (risky) information while there are no differences in applying privacy settings. We found no differences in the Facebook behavior of teenagers enrolled in different education forms. Implications of these results are discussed. PMID:25162234

  2. How Safe Do Teenagers Behave on Facebook? An Observational Study

    PubMed Central

    Vanderhoven, Ellen; Schellens, Tammy; Valcke, Martin; Raes, Annelies

    2014-01-01

    The substantial use of social network sites by teenagers has raised concerns about privacy and security. Previous research about behavior on social network sites was mostly based on surveys and interviews. Observational research overcomes problems inherent to this research method, for example social desirability. However, existing observational research mostly focuses on public profiles of young adults. Therefore, the current observation-study includes 1050 public and non-public Facebook-profiles of teenagers (13–18) to investigate (1) what kind of information teenagers post on their profile, (2) to what extent they protect this information using privacy-settings and (3) how much risky information they have on their profile. It was found that young people mostly post pictures, interests and some basic personal information on their profile. Some of them manage their privacy-settings as such that this information is reserved for friends' eyes only, but a lot of information is accessible on the friends-of-friends' pages. Although general risk scores are rather low, more detailed analyses show that teenagers nevertheless post a significant amount of risky information. Moreover, older teenagers and girls post more (risky) information while there are no differences in applying privacy settings. We found no differences in the Facebook behavior of teenagers enrolled in different education forms. Implications of these results are discussed. PMID:25162234

  3. TECHNIQUES AND METHODS Methods for Developmental Studies of Fear

    E-print Network

    Burgess, Neil

    TECHNIQUES AND METHODS Methods for Developmental Studies of Fear Conditioning Circuitry Daniel S as an aversive stimulus to document abnormal fear conditioning in chil- dren of parents with anxiety disorders- ogy of fear conditioning. Biol Psychiatry 2001;50: 225­228 © 2001 Society of Biological Psychiatry Key

  4. First results from the Very Small Array -- I. Observational methods

    E-print Network

    Robert A. Watson; Pedro Carreira; Kieran Cleary; Rod D. Davies; Richard J. Davis; Clive Dickinson; Keith Grainge; Carlos M. Gutierrez; Michael P. Hobson; Michael E. Jones; Rudiger Kneissl; Anthony Lasenby; Klaus Maisinger; Guy G. Pooley; Rafael Rebolo; Jose Alberto Rubino-Martin; Ben Rusholme; Richard D. E. Saunders; Richard Savage; Paul F. Scott; Anze Slosar; Pedro J. Sosa Molina; Angela C. Taylor; David Titterington; Elizabeth Waldram; Althea Wilkinson

    2003-03-04

    The Very Small Array (VSA) is a synthesis telescope designed to image faint structures in the cosmic microwave background on degree and sub-degree angular scales. The VSA has key differences from other CMB interferometers with the result that different systematic errors are expected. We have tested the operation of the VSA with a variety of blank-field and calibrator observations and cross-checked its calibration scale against independent measurements. We find that systematic effects can be suppressed below the thermal noise level in long observations; the overall calibration accuracy of the flux density scale is 3.5 percent and is limited by the external absolute calibration scale.

  5. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 15, METHOD 605--BENZIDINES

    EPA Science Inventory

    Seventeen laboratories participated in an interlaboratory study conducted to provide precision and accuracy statements for the proposed EPA Method 605 for measuring concentrations of the Category 7 chemicals benzidine and 3,3'dichlorobenzidine (DCB) in municipal and industrial aq...

  6. A Statistical Dead-Time Deconvolution Method for Fermi/GBM TGF Observations

    NASA Astrophysics Data System (ADS)

    Byrne, David; Briggs, Micheal S.; Tierney, David; Fitzpatrick, Gerard; Foley, Suzanne; McBreen, Sheila

    2013-04-01

    Terrestrial Gamma-ray Flashes (TGFs) were first observed by CGRO in 1994 and have continued to be observed by current gamma-ray telescopes such as Fermi/GBM. Today, TGFs are an area of continued interest and research although many questions remain despite close to 20 years of active research. One of the main reasons for the lack of understanding is the extremely fast, hard and intense nature of TGFs causing numerous instrumental effects in space based observatories. One such effect is that of dead-time which in Fermi/GBM is 2.6?s-count or up to ~ 1% of the TGF duration per count. A statistical temporal deconvolution method to recover the dead-time losses has been developed by members of the GBM collaboration1 . Simulations were performed using this method to determine how effective it is at reconstructing TGF time profiles. Presented here is the method and results of the study.

  7. 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;…

  8. Observation and Study of Interplanetary Scintillation with the Miyun Telescope

    NASA Astrophysics Data System (ADS)

    Zhang, X. Z.; Wu, J. H.

    We present the preliminary results of observation and study of interplanetry scintillation with the Miyun telescope at Beijing Astronomical Observatory. The properties of the telescope, observing parameters, and data reduction are described in this contribution. The telescope is used daily to trace some radio sources with time scale of several hours a day to measure the velocity variation of solar wind at a position which is relatively fixed to the Sun during each observation. Some observation examples and preliminary analysis are also given.

  9. 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.

  10. 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%…

  11. A facile method to observe graphene growth on copper foil.

    PubMed

    Yang, Fan; Liu, Yangqiao; Wu, Wei; Chen, Wei; Gao, Lian; Sun, Jing

    2012-11-30

    A novel scanning electron microscope (SEM) method is presented for high contrast identification of each layer of pyramidal graphene domains grown on copper. We obtained SEM images by combining the advantages of the high resolution property of the secondary electron signal and the elemental sensitivity of the backscattering electron signal. Through this method, we investigated the difference in the growth mechanisms of mono-layer and few-layer graphene. Due to different lattice mismatches, both the surface adsorption process and the epitaxial growth process existed under the atmospheric growth conditions. Moreover, the copper oxidation process can be easily discovered. It is obvious from the SEM images that the graphene greatly delayed the oxidation process of the copper surface. Finally, the nucleation and growth speed of graphene domains was found to depend on the linear array distribution of surface ledges and terraces of annealed rolled copper foil. This result explains the linear rows of graphene during the growth process and accords with theoretical results. PMID:23103913

  12. Bias correction methods for regional climate model simulations considering the distributional parametric uncertainty underlying the observations

    NASA Astrophysics Data System (ADS)

    Kim, Kue Bum; Kwon, Hyun-Han; Han, Dawei

    2015-11-01

    In this paper, we present a comparative study of bias correction methods for regional climate model simulations considering the distributional parametric uncertainty underlying the observations/models. In traditional bias correction schemes, the statistics of the simulated model outputs are adjusted to those of the observation data. However, the model output and the observation data are only one case (i.e., realization) out of many possibilities, rather than being sampled from the entire population of a certain distribution due to internal climate variability. This issue has not been considered in the bias correction schemes of the existing climate change studies. Here, three approaches are employed to explore this issue, with the intention of providing a practical tool for bias correction of daily rainfall for use in hydrologic models ((1) conventional method, (2) non-informative Bayesian method, and (3) informative Bayesian method using a Weather Generator (WG) data). The results show some plausible uncertainty ranges of precipitation after correcting for the bias of RCM precipitation. The informative Bayesian approach shows a narrower uncertainty range by approximately 25-45% than the non-informative Bayesian method after bias correction for the baseline period. This indicates that the prior distribution derived from WG may assist in reducing the uncertainty associated with parameters. The implications of our results are of great importance in hydrological impact assessments of climate change because they are related to actions for mitigation and adaptation to climate change. Since this is a proof of concept study that mainly illustrates the logic of the analysis for uncertainty-based bias correction, future research exploring the impacts of uncertainty on climate impact assessments and how to utilize uncertainty while planning mitigation and adaptation strategies is still needed.

  13. Disproportionality Methods for Pharmacovigilance in Longitudinal Observational Databases

    E-print Network

    Madigan, David

    community, pharmaceutical industry and health authorities to ensure that marketed drugs have acceptable Partnership 2 Columbia University 3 Johnson & Johnson Pharmaceutical Research and Development 4 University-approval studies but continues after regulatory market authorization when the drug is in widespread clinical use

  14. 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.

  15. A study on diffuse source detection by HXMT scanning observation

    E-print Network

    Guan, Ju; Wu, Mei; Song, Li-Ming; Huo, Zhuo-Xi

    2015-01-01

    The Hard X-ray Modulation Telescope (HXMT) is a collimated scan X-ray satellite mainly devoted to a sensitive all-sky survey and pointed observations in 1-250 keV. We expect various diffuse sources to be detected in its scanning observations due to the large rigidity factor of the telescope. Diffuse source detection performance of HXMT scanning observation depends not only on the instrument but also on its data analysis method since images have to be reconstructed from HXMT observed data. In this paper, we introduce a multiscale maximum entropy (MSME) algorithm for HXMT image restoration and propose an improved method, ensemble multiscale maximum entropy (EMSME) method, to alleviate the problem of mode mixing exiting in MSME. Simulation have been performed on the detection of the diffuse source Cen A by HXMT in the all-sky survey mode. The results show that the MSME method is adapted to the deconvolution task of HXMT for diffuse source detection and the improved method could suppress noise and improve the cor...

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

    SciTech Connect

    Kwong, W.; 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{sigma} level is about 4000--5000 for electron scattering experiments and about 2000 for deuterium dissociation experiments.

  17. Observations in UV band and problems of star formation studies.

    NASA Astrophysics Data System (ADS)

    Wiebe, D.

    2008-12-01

    In this contibution I consider those aspects of the modern star formation theory, which can be substantiated with observations in UV band, paying special attention to early stages of molecular cloud formation and initial conditions for the chemical evolution of starless cores. I describe main results of available diffuse cloud observations in UV band as well a s prospective directions for future studies.

  18. MOOSES: Multiple Option Observation System for Experimental Studies.

    ERIC Educational Resources Information Center

    Tapp, Jon; Wehby, Joseph

    The Multiple Option Observation System for Experimental Studies (MOOSES) is a flexible data collection and analysis package for applied behavioral research that addresses the needs of researchers interested in live coding of observational data. MOOSES allows the researcher to design a coding system for a particular research question. General types…

  19. An Observational Study of Social Processes in Microcomputer Classrooms.

    ERIC Educational Resources Information Center

    Feldmann, Shirley C.; And Others

    This observational study examined student and teacher verbal and nonverbal behaviors in microcomputer classrooms in a high school where most of the students are Black, Hispanic, or Asian, and almost half of them are classified as economically disadvantaged. A total of 125 students in grades 9 to 12 were observed, with 47 students in marketing, 18…

  20. Association between day of delivery and obstetric outcomes: observational study

    PubMed Central

    Bottle, A; Aylin, P

    2015-01-01

    Study question What is the association between day of delivery and measures of quality and safety of maternity services, particularly comparing weekend with weekday performance? Methods This observational study examined outcomes for maternal and neonatal records (1?332?835 deliveries and 1?349?599 births between 1 April 2010 and 31 March 2012) within the nationwide administrative dataset for English National Health Service hospitals by day of the week. Groups were defined by day of admission (for maternal indicators) or delivery (for neonatal indicators) rather than by day of complication. Logistic regression was used to adjust for case mix factors including gestational age, birth weight, and maternal age. Staffing factors were also investigated using multilevel models to evaluate the association between outcomes and level of consultant presence. The primary outcomes were perinatal mortality and—for both neonate and mother—infections, emergency readmissions, and injuries. Study answer and limitations Performance across four of the seven measures was significantly worse for women admitted, and babies born, at weekends. In particular, the perinatal mortality rate was 7.3 per 1000 babies delivered at weekends, 0.9 per 1000 higher than for weekdays (adjusted odds ratio 1.07, 95% confidence interval 1.02 to 1.13). No consistent association between outcomes and staffing was identified, although trusts that complied with recommended levels of consultant presence had a perineal tear rate of 3.0% compared with 3.3% for non-compliant services (adjusted odds ratio 1.21, 1.00 to 1.45). Limitations of the analysis include the method of categorising performance temporally, which was mitigated by using a midweek reference day (Tuesday). Further research is needed to investigate possible bias from unmeasured confounders and explore the nature of the causal relationship. What this study adds This study provides an evaluation of the “weekend effect” in obstetric care, covering a range of outcomes. The results would suggest approximately 770 perinatal deaths and 470 maternal infections per year above what might be expected if performance was consistent across women admitted, and babies born, on different days of the week. Funding, competing interests, data sharing The research was partially funded by Dr Foster Intelligence and the National Institute for Health Research (NIHR) Imperial Patient Safety Translational Research Centre in partnership with the Health Protection Research Unit (HPRU) in Healthcare Associated Infection and Antimicrobial Resistance at Imperial College London. WLP was supported by the National Audit Office. PMID:26602245

  1. 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

  2. Epidemiology Commentary What can we really learn from observational studies? The need for empirical

    E-print Network

    Madigan, David

    Epidemiology Commentary What can we really learn from observational studies? The need for empirical on expanded secondary use of observational healthcare data and have thrust the field of epidemiology, open questions include: - Which statistical and epidemiological methods work best for different types

  3. 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…

  4. Ten Inquiry Methods Used in Curriculum Studies.

    ERIC Educational Resources Information Center

    Short, Edmund C.

    Ten different methods of inquiry are outlined in this overview of research methodologies currently being employed in the field of curriculum studies: (1) philosophical, (2) historical, (3) scientific, (4) artistic, (5) moral, (6) religious, (7) interpretive, (8) instrumental, (9) deliberative, and (10) action oriented. Each of the 10 methods is…

  5. Carbon nanotubes : a study on assembly methods

    E-print Network

    Quiñones, Lisandro E. (Quiñones Ortiz)

    2008-01-01

    The urgent stipulation is to manufacture CNTs of desired properties and dimensions. The heart of this yearning lies in understanding the growth and assembly methods of CNTs, which are not yet clear. In this study, hence, ...

  6. 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.

  7. A method of initial orbit determination from three or more observations on a short arc. (Russian Title: ????? ??????????? ?????????????? ?????? ?? ???? ? ????? ??????????? ?? ???????? ????)

    NASA Astrophysics Data System (ADS)

    Shefer, V. A.

    2010-12-01

    A new method is suggested for computing the initial orbit of a small celestial body from its three or more pairs of angular measurements at three times. The method is based on using the approach that we previously developed for constructing the intermediate orbit from minimal number of observations. This intermediate orbit allows for most of the perturbations in the motion of the body under study. The method proposed uses the Herget's algorithmic scheme that makes it possible to involve additional observations as well. The methodical error of orbit computation by the proposed method is two orders smaller than the corresponding error of the Herget's approach based on the construction of the unperturbed Keplerian orbit. The new method is especially efficient if applied to high-accuracy observational data covering short orbital arcs.

  8. A new method of preliminary orbit determination from three or more observations on a short arc. (Russian Title: ????? ????? ??????????? ??????????????? ?????? ?? ???? ? ????? ??????????? ?? ???????? ????)

    NASA Astrophysics Data System (ADS)

    Shefer, V. A.

    2011-07-01

    A new method is suggested for finding the preliminary orbit of a small celestial body from its three or more pairs of angular measurements at three times. The method is based on using the approach that we previously developed for constructing the intermediate orbit from minimal number of observations. This intermediate orbit allows for most of the perturbations in the motion of the body under study. The method proposed uses the Herget's algorithmic scheme that makes it possible to involve additional observations as well. The methodical error of orbit computation by the proposed method is two orders smaller than the corresponding error of the commonly used approach based on the construction of the unperturbed Keplerian orbit. The new method is especially efficient if applied to high-accuracy observational data covering short orbital arcs.

  9. 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)

  10. 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

  11. 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.

  12. Method for residual household waste composition studies.

    PubMed

    Sahimaa, Olli; Hupponen, Mari; Horttanainen, Mika; Sorvari, Jaana

    2015-12-01

    The rising awareness of decreasing natural resources has brought forward the idea of a circular economy and resource efficiency in Europe. As a part of this movement, European countries have identified the need to monitor residual waste flows in order to make recycling more efficient. In Finland, studies on the composition of residual household waste have mostly been conducted using different methods, which makes the comparison of the results difficult. The aim of this study was to develop a reliable method for residual household waste composition studies. First, a literature review on European study methods was performed. Also, 19 Finnish waste composition studies were compared in order to identify the shortcomings of the current Finnish residual household waste composition data. Moreover, the information needs of different waste management authorities concerning residual household waste were studied through a survey and personal interviews. Stratification, sampling, the classification of fractions and statistical analysis were identified as the key factors in a residual household waste composition study. The area studied should be divided into non-overlapping strata in order to decrease the heterogeneity of waste and enable comparisons between different waste producers. A minimum of six subsamples, each 100kg, from each stratum should be sorted. Confidence intervals for each waste category should be determined in order to evaluate the applicability of the results. A new three-level classification system was created based on Finnish stakeholders' information needs and compared to four other European waste composition study classifications. PMID:26337965

  13. 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.

  14. Stronger instruments via integer programming in an observational study of late preterm birth outcomes

    E-print Network

    Small, Dylan

    Stronger instruments via integer programming in an observational study of late preterm birth the methods in our on-going study of outcomes of late-preterm births in California, that is, births of 34 to 36 weeks of gestation. Would lengthening the time in the hospital for such births reduce

  15. GP treatment decisions for patients with depression: an observational study

    PubMed Central

    Kendrick, Tony; King, Fiona; Albertella, Louise; Smith, Peter WF

    2005-01-01

    Background GPs are prescribing more antidepressants than previously, but not in accordance with guidelines. The reasons why they prescribe are not well understood. Aim To explore associations between GP treatment and severity of depression, patients' life difficulties, previous history of illness and treatment, and patient attitudes. Design Observational study in two phases, 3 years apart. Setting Seven practices in Southampton, UK. Method Adult attenders who consented were screened for depression in the waiting room. After the consultation, the 17 participating GPs completed questionnaires on the perceived presence and severity of depression, patients' life difficulties, previous problems and treatment, patient attitudes towards antidepressants, and their treatment decisions. Patients returned postal questionnaires on sociodemographics, life events, physical health, and attitudes towards antidepressants. Results Of 694 patients screened in the two phases, the GPs rated 101 (15%) as depressed, acknowledged depression in 44 cases (6%), and offered treatment in 27 (4%), including antidepressants in 14 (2%). Offers of antidepressants were more likely in both phases where the GPs rated the depression as moderate rather than mild, and where they perceived a positive patient attitude to antidepressants. However, GP ratings of severity did not agree well with the validated screening instrument, and their assessments of patients' attitudes to treatment were only moderately related to patients' self-reports. Conclusions In line with current guidelines, GPs base prescribing decisions on the perceived severity of depression, taking patients' preferences into account, but they do not accurately identify which patients are likely to benefit from treatment. Better ways to assess depression severity and patient attitudes towards antidepressants are needed in order to target treatment more appropriately. PMID:15826435

  16. An observational study of adults seeking emergency care in Cambodia

    PubMed Central

    Yan, Lily D; Mahadevan, Swaminatha V; Yore, Mackensie; Pirrotta, Elizabeth A; Woods, Joan; Somontha, Koy; Sovannra, Yim; Raman, Maya; Cornell, Erika; Grundmann, Christophe

    2015-01-01

    Abstract Objective To describe the characteristics and chief complaints of adults seeking emergency care at two Cambodian provincial referral hospitals. Methods Adults aged 18 years or older who presented without an appointment at two public referral hospitals were enrolled in an observational study. Clinical and demographic data were collected and factors associated with hospital admission were identified. Patients were followed up 48 hours and 14 days after presentation. Findings In total, 1295 hospital presentations were documented. We were able to follow up 85% (1098) of patients at 48 hours and 77% (993) at 14 days. The patients’ mean age was 42 years and 64% (823) were females. Most arrived by motorbike (722) or taxi or tuk-tuk (312). Most common chief complaints were abdominal pain (36%; 468), respiratory problems (15%; 196) and headache (13%; 174). Of the 1050 patients with recorded vital signs, 280 had abnormal values, excluding temperature, on arrival. Performed diagnostic tests were recorded for 539 patients: 1.2% (15) of patients had electrocardiography and 14% (175) had diagnostic imaging. Subsequently, 783 (60%) patients were admitted and 166 of these underwent surgery. Significant predictors of admission included symptom onset within 3 days before presentation, abnormal vital signs and fever. By 14-day follow-up, 3.9% (39/993) of patients had died and 19% (192/993) remained functionally impaired. Conclusion In emergency admissions in two public hospitals in Cambodia, there is high admission-to-death ratio and limited application of diagnostic techniques. We identified ways to improve procedures, including better documentation of vital signs and increased use of diagnostic techniques. PMID:25883401

  17. Interstellar dust: interfacing laboratory, theoretical and observational studies

    NASA Astrophysics Data System (ADS)

    Jones, Anthony Peter

    2015-08-01

    In this talk I will consider how our understanding of interstellar dust can only be advanced through a combination of laboratory, theoretical and observational studies, which provide the critical framework for advancing our understanding. I will summarise what we currently know, or think we know, about the physical and compositional properties of dust and their evolution in interstellar media. Along the way I will question the utility of astronomical dust analogues and show, based on data from the laboratory, theoretical studies and from astronomical observations, that some of our prior interpretations need to be subjected to a critical re-evaluation. I will present interstellar dust modelling from a new vantage point and review ideas on the interpretation of observations within the framework of this model and its predictions for dust evolution within and between interstellar media. Finally, I will summarise some of the current outstanding issues and what we would like to learn in the future.

  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. Observations on the fifth-order WENO method with non-uniform meshes

    E-print Network

    Spiteri, Raymond J.

    Observations on the fifth-order WENO method with non-uniform meshes Rong Wang, a,1 Hui Feng, b,2 essentially non-oscillatory (WENO) methods are a popular high-order spatial discretization for hyperbolic partial differential equations. Typical treat- ments of WENO methods assume a uniform mesh. In this paper

  20. 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.

  1. 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.

  2. Eect Modi...cation and Design Sensitivity in Observational Studies

    E-print Network

    Small, Dylan

    ; observational study; sensitivity analysis; Stephenson's test; truncated product of P-values; U- statistic; Wilcoxon test 1 Address for correspondence: Department of Statistics, The Wharton School, University by Corn...eld et al. (1959) in their discussion of heavy smoking as a cause of lung cancer, concluding

  3. RANDOMIZED EXPERIMENTS AND OBSERVATIONAL STUDIES: CAUSAL INFERENCE IN STATISTICS

    E-print Network

    George, Edward I.

    RANDOMIZED EXPERIMENTS AND OBSERVATIONAL STUDIES: CAUSAL INFERENCE IN STATISTICS PAUL R. ROSENBAUM Roiniczych, Tom X, pp1-51. Reprinted in English in Statistical Science, 1990, 5, 463-480, with discussion., Lilienfeld, A., Shimkin, M., and Wynder, E. (1959). Smoking and lung cancer: Recent evidence and a discussion

  4. Scientific and Ethical Approaches for Observational Exposure Studies

    EPA Science Inventory

    Researchers conduct observational human exposure studies to understand how and the extent to which people come into contact with chemicals and environmental stressors in their everyday lives, through the air they breathe, the food and liquids they consume, and the things they tou...

  5. The Indiana Science Initiative: Lessons from a Classroom Observation Study

    ERIC Educational Resources Information Center

    Cook, Nicole D.; Walker, William S.; Weaver, Gabriela C.; Sorge, Brandon H.

    2015-01-01

    The Indiana Science Initiative (ISI) is a systemic effort to reform K-8 science education. The program provides teachers with professional development, reform-oriented science modules, and materials support. To examine the impact of the initiative's professional development, a participant observation study was conducted in the program's pilot…

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

    E-print Network

    Clark, William R.

    under the most simple survey designs such as simple random sampling (SRS) and stratified random sampling surveys rely on probability sampling to choose sample units (e.g., small areas or individualsSpecial Section: Observational Studies Sampling Considerations for Disease Surveillance in Wildlife

  7. Study of white-light flares observed by Hinode

    NASA Astrophysics Data System (ADS)

    Wang, Hai-Min

    2009-02-01

    White-light flares are considered to be the most energetic flaring events that are observable in the optical broad-band continuum of the solar spectrum. They have not been commonly observed. Observations of white-light flares with sub-arcsecond resolution have been very rare. The continuous high resolution observations of Hinode provide a unique opportunity to systematically study the white-light flares with a spatial resolution around 0.2 arcsec. We surveyed all the flares above GOES magnitude C5.0 since the launch of Hinode in 2006 October. 13 of these kinds of flares were covered by the Hinode G-band observations. We analyzed the peak contrasts and equivalent areas (calculated via integrated excess emission contrast) of these flares as a function of the GOES X-ray flux, and found that the cut-off visibility is likely around M1 flares under the observing limit of Hinode. Many other observational and physical factors should affect the visibility of white-light flares; as the observing conditions are improved, smaller flares are likely to have detectable white-light emissions. We are cautious that this limiting visibility is an overestimate, because G-band observations contain emissions from the upper atmosphere. Among the 13 events analyzed, only the M8.7 flare of 2007 June 4 had near-simultaneous observations in both the G-band and the blue continuum. The blue continuum had a peak contrast of 94% vs. 175% in G-band for this event. The equivalent area in the blue continuum is an order of magnitude lower than that in the G-band. Very recently, Jess et al. studied a C2.0 flare with a peak contrast of 300% in the blue continuum. Compared to the events presented in this letter, that event is probably an unusual white-light flare: a very small kernel with a large contrast that can be detected in high resolution observations.

  8. Comparison of different methods to compute a preliminary orbit of Space Debris using radar observations

    NASA Astrophysics Data System (ADS)

    Ma, Hélène; Gronchi, Giovanni F.

    2014-07-01

    We advertise a new method of preliminary orbit determination for space debris using radar observations, which we call Infang †. We can perform a linkage of two sets of four observations collected at close times. The context is characterized by the accuracy of the range ?, whereas the right ascension ? and the declination ? are much more inaccurate due to observational errors. This method can correct ?, ?, assuming the exact knowledge of the range ?. Considering no perturbations from the J 2 effect, but including errors in the observations, we can compare the new method, the classical method of Gibbs, and the more recent Keplerian integrals method. The development of Infang is still on-going and will be further improved and tested.

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

    SciTech Connect

    Sale, Michael J; Pan, Feifei; Peters-Lidard, C. D.

    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.

  10. Inverse Method for Estimating the Spatial Variability of Soil Particle Size Distribution from Observed Soil Moisture

    SciTech Connect

    Pan, Feifei; Peters-lidard, Christa D.; King, Anthony Wayne

    2010-11-01

    Soil particle size distribution (PSD) (i.e., clay, silt, sand, and rock contents) information is one of critical factors for understanding water cycle since it affects almost all of water cycle processes, e.g., drainage, runoff, soil moisture, evaporation, and evapotranspiration. With information about soil PSD, we can estimate almost all soil hydraulic properties (e.g., saturated soil moisture, field capacity, wilting point, residual soil moisture, saturated hydraulic conductivity, pore-size distribution index, and bubbling capillary pressure) based on published empirical relationships. Therefore, a regional or global soil PSD database is essential for studying water cycle regionally or globally. At the present stage, three soil geographic databases are commonly used, i.e., the Soil Survey Geographic database, the State Soil Geographic database, and the National Soil Geographic database. Those soil data are map unit based and associated with great uncertainty. Ground soil surveys are a way to reduce this uncertainty. However, ground surveys are time consuming and labor intensive. In this study, an inverse method for estimating mean and standard deviation of soil PSD from observed soil moisture is proposed and applied to Throughfall Displacement Experiment sites in Walker Branch Watershed in eastern Tennessee. This method is based on the relationship between spatial mean and standard deviation of soil moisture. The results indicate that the suggested method is feasible and has potential for retrieving soil PSD information globally from remotely sensed soil moisture data.

  11. Research of the orbit fitting method using rectangular coordinates as observations. (Russian Title: ???????????? ??????? ????????? ?????, ????????????? ????????????? ?????????? ? ???????? ??????????)

    NASA Astrophysics Data System (ADS)

    Baturin, A. P.

    2009-10-01

    The theoretical and experimental research of the least-square orbit fitting method using rectangular coordinates as observations has been completed in the case of just angular observations used. In this case missing celestial object distances are replaced by their calculated values in the orbit fitting iterative process. It has been indicated that considered fitting method is equivalent to the standard one the weight coefficients are proportional to squared inverse distances of the observed object. Besides, it has been shown that the considered method has usually greater convergence region to compare with a region of the standard one.

  12. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration.

    PubMed

    Vandenbroucke, Jan P; von Elm, Erik; Altman, Douglas G; Gøtzsche, Peter C; Mulrow, Cynthia D; Pocock, Stuart J; Poole, Charles; Schlesselman, James J; Egger, Matthias

    2014-12-01

    Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research. PMID:25046751

  13. 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.

  14. Evaluating the effectiveness of the extrafocal images method when observing low-orbiting space objects

    NASA Astrophysics Data System (ADS)

    Shumilov, Yu. P.; Vygon, V. G.; Grishin, E. A.; Shargorodskii, V. D.

    2015-05-01

    The report examines key characteristics of the extrafocal images method. This is the extrafocal images detection planes position and a minimum level of difference between the images energy. The method is used for image reconstruction of low-orbit space objects observed through a turbulent atmosphere. The advantage of this method is the ability to restore the image using one frame. Analysis of line of sight shake compensation and a comparison with the method of triple correlations were performed.

  15. Method for optimizing channelized quadratic observers for binary classification of large-dimensional image datasets

    PubMed Central

    Kupinski, M. K.; Clarkson, E.

    2015-01-01

    We present a new method for computing optimized channels for channelized quadratic observers (CQO) that is feasible for high-dimensional image data. The method for calculating channels is applicable in general and optimal for Gaussian distributed image data. Gradient-based algorithms for determining the channels are presented for five different information-based figures of merit (FOMs). Analytic solutions for the optimum channels for each of the five FOMs are derived for the case of equal mean data for both classes. The optimum channels for three of the FOMs under the equal mean condition are shown to be the same. This result is critical since some of the FOMs are much easier to compute. Implementing the CQO requires a set of channels and the first- and second-order statistics of channelized image data from both classes. The dimensionality reduction from M measurements to L channels is a critical advantage of CQO since estimating image statistics from channelized data requires smaller sample sizes and inverting a smaller covariance matrix is easier. In a simulation study we compare the performance of ideal and Hotelling observers to CQO. The optimal CQO channels are calculated using both eigenanalysis and a new gradient-based algorithm for maximizing Jeffrey's divergence (J). Optimal channel selection without eigenanalysis makes the J-CQO on large-dimensional image data feasible. PMID:26366764

  16. 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...

  17. 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)

  18. 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.

  19. 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

  20. Tropospheric Chemistry Studies using Observations from GOME and TOMS

    NASA Technical Reports Server (NTRS)

    Chance, Kelly; Spurr, Robert J. D.; Kurosu, Thomas P.; Jacob, Daniel J.; Gleason, James F.

    2003-01-01

    Studies to quantitatively determine trace gas and aerosol amounts from the Global Ozone Monitoring Experiment (GOME) and the Total Ozone Monitoring Experiment (TOMS) and to perform chemical modeling studies which utilize these results are given. This includes: 1. Analysis of measurements from the GOME and TOMS instruments for troposphere distributions of O3 and HCHO; troposphere enhancements of SO2, NO2 and aerosols associated with major sources; and springtime events of elevated BrO in the lower Arctic troposphere. 2. Application of a global 3-dimensional model of troposphere chemistry to interpret the GOME observations in terms of the factors controlling the abundances of troposphere ozone and OH.

  1. Photometric Observational and Modelling Study on the Asteroid (26) Proserpina

    NASA Astrophysics Data System (ADS)

    Li, B.; Zhao, H. B. Wang, X.

    2015-07-01

    We present new CCD observations of the asteroid (26) Proserpina carried out between 2011 December and 2012 February. A synodic period of (13.107± 0.002) h based upon the new observations is obtained. Using all available light curves, the spin vectors, period of rotation, and the shape model of the asteroid are determined with the convex inversion method. Further more, a Bootstrap method is applied to estimate the uncertainties of the spin parameters. We derive a pair of possible poles for (26) Proserpina, and believe that it has a retrograde rotation state. The poles are determined ?_1=90.8° ± 1.4°, ?_1=-53.1° ±3.2° ,and mirror solution of ?_2=259.3° ±2.2°,?_2=-62.0° ±2.0°. The spin period corresponding to the two poles is almost the same as (13.109777± 3.8× 10^{-6}) hours. For the asteroid, the convex shapes corresponding to the pairs of poles are mirror images of each other.

  2. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 24, METHOD 601--PURGEABLE HALOCARBONS BY THE PURGE TRAP METHOD

    EPA Science Inventory

    The experimental design and results of a validations study for an analytical method to detect 29 halocarbons in water are described herein. In Method 601, the halocarbons are purged by an inert gas which is bubbled through the aqueous sample. The vapors are then trapped in a shor...

  3. 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.

  4. Solar Flare Predictions Using Time Series of SDO/HMI Observations and Machine Learning Methods

    NASA Astrophysics Data System (ADS)

    Ilonidis, Stathis; Bobra, Monica; Couvidat, Sebastien

    2015-08-01

    Solar active regions are dynamic systems that can rapidly evolve in time and produce flare eruptions. The temporal evolution of an active region can provide important information about its potential to produce major flares. In this study, we build a flare forecasting model using supervised machine learning methods and time series of SDO/HMI data for all the flaring regions with magnitude M1.0 or higher that have been observed with HMI and several thousand non-flaring regions. We define and compute hundreds of features that characterize the temporal evolution of physical properties related to the size, non-potentiality, and complexity of the active region, as well as its flaring history, for several days before the flare eruption. Using these features, we implement and test the performance of several machine learning algorithms, including support vector machines, neural networks, decision trees, discriminant analysis, and others. We also apply feature selection algorithms that aim to discard features with low predictive power and improve the performance of the machine learning methods. Our results show that support vector machines provide the best forecasts for the next 24 hours, achieving a True Skill Statistic of 0.923, an accuracy of 0.985, and a Heidke skill score of 0.861, which improve the scores obtained by Bobra and Couvidat (2015). The results of this study contribute to the development of a more reliable and fully automated data-driven flare forecasting system.

  5. Developing best practices teaching procedures for skinfold assessment: observational examination using the Think Aloud method.

    PubMed

    Holmstrup, Michael E; Verba, Steven D; Lynn, Jeffrey S

    2015-12-01

    Skinfold assessment is valid and economical; however, it has a steep learning curve, and many programs only include one exposure to the technique. Increasing the number of exposures to skinfold assessment within an undergraduate curriculum would likely increase skill proficiency. The present study combined observational and Think Aloud methodologies to quantify procedural and cognitive characteristics of skinfold assessment. It was hypothesized that 1) increased curricular exposure to skinfold assessment would improve proficiency and 2) the combination of an observational and Think Aloud analysis would provide quantifiable areas of emphasis for instructing skinfold assessment. Seventy-five undergraduates with varied curricular exposure performed a seven-site skinfold assessment on a test subject while expressing their thoughts aloud. A trained practitioner recorded procedural observations, with transcripts generated from audio recordings to capture cognitive information. Skinfold measurements were compared with a criterion value, and bias scores were generated. Participants whose total bias fell within ±3.5% of the criterion value were proficient, with the remainder nonproficient. An independent-samples t-test was used to compare procedural and cognitive observations across experience and proficiency groups. Additional curricular exposure improved performance of skinfold assessment in areas such as the measurement of specific sites (e.g., chest, abdomen, and thigh) and procedural (e.g., landmark identification) and cognitive skills (e.g., complete site explanation). Furthermore, the Think Aloud method is a valuable tool for determining curricular strengths and weaknesses with skinfold assessment and as a pedagogical tool for individual instruction and feedback in the classroom. PMID:26628650

  6. 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.

  7. 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…

  8. Clinical signs of ICU syndrome/delirium: an observational study.

    PubMed

    Granberg-Axèll, A; Bergbom, I; Lundberg, D

    2001-04-01

    Some clinical signs of the intensive care unit (ICU) syndrome/delirium are probably known, but there may be additional signs that can be observed during the care of ICU patients. The aim of this study was to investigate and describe the clinical signs of the ICU syndrome in relation to patients' reactions and behaviour following the second day of their stay in an ICU. A total of 31 patients were observed during the weaning process and in the days following extubation. Informal dialogues between the patient and the observer, using parts of the questionnaire 'Organic Brain Syndrome Scale' were also carried out. The data was structured in a chronological order and consists of descriptions of patients' behaviour and reactions, together with events, occurrences and environmental circumstances. It was found that the patients showed a great variety of clinical signs that could be related to the ICU syndrome. Such signs were the quality, ability and divergence of speech; talking, movements, bodily position and facial expressions. Several patients also related unreal experiences only occasionally, while others experienced them during longer periods. The clinical signs did not seem to be separate phenomena but were inter-connected and part of a progression, and, therefore must be seen in the overall context and situation. Longer periods of observation and repeated interaction with patients are necessary in order to be aware of onset and clinical signs of the ICU syndrome. PMID:11817445

  9. Observation of a freezing drizzle episode: A case study

    NASA Astrophysics Data System (ADS)

    Fernández-González, S.; Valero, F.; Sanchez, Jose L.; Gascón, E.; López, L.; García-Ortega, E.; Merino, A.

    2014-11-01

    On 5 February 2012 an episode of freezing precipitation took place in the Guadarrama Mountains, at the center of the Iberian Peninsula. This precipitation affected high elevations, where temperatures remained below freezing because of snow cover that had accumulated from snowfall during the previous days. The case study was recorded by surface synoptic observations (SYNOP) at Navacerrada Pass meteorological observatory (belonging to the National Weather Service of Spain). To study winter cloud systems during the TEcoAgua project, a multichannel ground-based microwave radiometer (MMWR), Micro Rain Radar (MRR-2), and isothermal cloud chamber were installed in the study area, thus permitting the monitoring of the freezing precipitation event. Analysis using Meteosat Second Generation (MSG) satellite data and observations permitted the determination of factors that triggered the freezing precipitation event. Freezing drizzle was interspersed with the passage of a warm and cold front. During frontal passage, mid-level clouds inhibited the generation of freezing drizzle, with snowfall recorded in the study area. However, during the period between the two fronts, an absence of mid-level clouds permitted low-level orographic clouds to persist upwind of the mountain system, producing freezing drizzle at the surface. The decisive factors for the generation of freezing drizzle were high humidity at low levels, weak mesoscale updrafts caused by the topography, stability at mid levels, cloud-top temperatures warmer than - 15 °C, and low concentrations of ice nuclei.

  10. 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)

  11. 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

  12. Studies of Tropical/Mid-Latitude Exchange Using UARS Observations

    NASA Technical Reports Server (NTRS)

    Avallone, Linnea

    2001-01-01

    At the time this proposal was submitted, recent publications had suggested an important role for transport of midlatitude air into the tropical lower stratosphere. Most of these studies had employed data that gave only a time-averaged picture, making it difficult to determine the nature of the transport processes responsible for the observed behavior. We proposed to analyze observations of long-lived trace gases, such as nitric acid, methane, nitrous oxide, and chlorofluorocarbons, made from the Upper Atmosphere Research Satellite, to investigate the seasonal behavior of mixing between the midlatitudes and tropics. We planned to construct probability distributions of the concentrations of these species over small altitude ranges and to compare them to expectations based on modeled mean concentrations and knowledge of instrument precision. Differences from expectation were to be analyzed with respect to meteorological parameters to determine whether wave activity may have induced apparent mixing.

  13. Case studies: Soil mapping using multiple methods

    NASA Astrophysics Data System (ADS)

    Petersen, Hauke; Wunderlich, Tina; Hagrey, Said A. Al; Rabbel, Wolfgang; Stümpel, Harald

    2010-05-01

    Soil is a non-renewable resource with fundamental functions like filtering (e.g. water), storing (e.g. carbon), transforming (e.g. nutrients) and buffering (e.g. contamination). Degradation of soils is meanwhile not only to scientists a well known fact, also decision makers in politics have accepted this as a serious problem for several environmental aspects. National and international authorities have already worked out preservation and restoration strategies for soil degradation, though it is still work of active research how to put these strategies into real practice. But common to all strategies the description of soil state and dynamics is required as a base step. This includes collecting information from soils with methods ranging from direct soil sampling to remote applications. In an intermediate scale mobile geophysical methods are applied with the advantage of fast working progress but disadvantage of site specific calibration and interpretation issues. In the framework of the iSOIL project we present here some case studies for soil mapping performed using multiple geophysical methods. We will present examples of combined field measurements with EMI-, GPR-, magnetic and gammaspectrometric techniques carried out with the mobile multi-sensor-system of Kiel University (GER). Depending on soil type and actual environmental conditions, different methods show a different quality of information. With application of diverse methods we want to figure out, which methods or combination of methods will give the most reliable information concerning soil state and properties. To investigate the influence of varying material we performed mapping campaigns on field sites with sandy, loamy and loessy soils. Classification of measured or derived attributes show not only the lateral variability but also gives hints to a variation in the vertical distribution of soil material. For all soils of course soil water content can be a critical factor concerning a succesful application of geophysical methods, e.g. GPR on wet loessy soils will result in a high attenuation of signals. Furthermore, with this knowledge we support the development of geophysical pedo-transfer-functions, i.e. the link between geophysical to soil parameters, which is active researched in another work package of the iSOIL project. Acknowledgement: iSOIL-Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping is a Collaborative Project (Grant Agreement number 211386) co-funded by the Research DG of the European Commission within the RTD activities of the FP7 Thematic Priority Environment.

  14. A Study on Feature of Eye Tracking in Difference of Skill Level during Observational Learning of Movement

    NASA Astrophysics Data System (ADS)

    Nuruki, Atsuo; Shimozono, Tomoyuki; Kawabata, Takuro; Yamada, Masafumi; Yunokuchi, Kazutomo; Maruyama, Atsuo

    Recently, it often said that it is one of the means that the observational learning promotes the acquisition of sports and athletic skills. We think that the inexperienced person can efficiently acquire athletic skills by using the observational method of the expert as an index of the observational method in the observational learning. Then, in the present study, the expert and inexperienced person's glance characteristic were compared, and it was examined whether the observational method of the expert was able to be used as an index of the observational method of the inexperienced person. The glance characteristics are a glance transition, glance total moved distance, the gazing duration, moreover glance moved distance and radial velocity between each gaze points. Additionally, we investigated whether there was a change in physical performance before and after the observational learning, and two different observational learning groups (the expert's observational method group, the free observation group). In result, it was clarified that the expert concentrated, observed a constant part of the movement, and the inexperienced person was observing the entire movement. Moreover, the result that glance total moved distance was shorter than the inexperienced person, and expert's gazing duration was longer than the inexperienced person. It was clarified that the expert was efficiently emphatically observing the point of the movement from these results. In addition, the inexperienced persons have advanced physical performance through the observational learning. Then the expert's observational method group advanced physical performance better than the free observation group. Therefore we suggested that the observational method of the expert be able to be used as an index of the method of observing the inexperienced person.

  15. Study of optimum methods of optical communication

    NASA Technical Reports Server (NTRS)

    Harger, R. O.

    1972-01-01

    Optimum methods of optical communication accounting for the effects of the turbulent atmosphere and quantum mechanics, both by the semi-classical method and the full-fledged quantum theoretical model are described. A concerted effort to apply the techniques of communication theory to the novel problems of optical communication by a careful study of realistic models and their statistical descriptions, the finding of appropriate optimum structures and the calculation of their performance and, insofar as possible, comparing them to conventional and other suboptimal systems are discussed. In this unified way the bounds on performance and the structure of optimum communication systems for transmission of information, imaging, tracking, and estimation can be determined for optical channels.

  16. Exploring the Ethics of Observational Research: The Case of an HIV Study in Tanzania

    PubMed Central

    Norris, Alison; Jackson, Ashley; Khoshnood, Kaveh

    2013-01-01

    Background Observational studies have generally been viewed as incurring minimal risk to participants, resulting in fewer ethical obligations for investigators than intervention studies. In 2004, the lead author (AN) carried out an observational study measuring sexual behavior and the prevalence of HIV, syphilis, and herpes simplex virus type 2 (HSV-2), among Tanzanian agricultural plantation residents (results reported elsewhere). This article uses an ethical lens to consider the consequences of the observational study and explore what, if any, effects it had on participants and their community. Methods Using a case study approach, we critically examine three core principles of research ethics—respect for persons/autonomy; beneficence/nonmaleficence; and distributive justice—as manifested in the 2004 observational study. We base our findings on three sources: discussions with plantation residents following presentations of observational research findings; in-depth interviews with key informants; and researcher observations. Results The observational research team was found to have ensured confidentiality and noncoercive recruitment. Ironically, maintenance of confidentiality and voluntary participation led some participants to doubt study results. Receiving HIV test results was important for participants and contributed to changing community norms about HIV testing. Conclusions Observational studies may act like de facto intervention studies and thus incur obligations similar to those of intervention studies. We found that ensuring respect for persons may have compromised the principles of beneficence and distributive justice. While in theory these three ethical principles have equal moral force, in practice, researchers may have to prioritize one over the others. Careful community engagement is necessary to promote well-considered ethical decisions. PMID:24069546

  17. Computational studies of sialyllactones: methods and uses.

    PubMed

    Parrill, A L; Mamuya, N; Dolata, D P; Gervay, J

    1997-06-01

    N-Acetylneuraminic acid (1) is a common sugar in many biological recognition processes. Neuraminidase enzymes recognize and cleave terminal sialic acids from cell surfaces. Viral entry into host cells requires neuraminidase activity, thus inhibition of neuraminidase is a useful strategy for development of drugs for viral infections. A recent crystal structure for influenza viral neuraminidase with sialic acid bound shows that the sialic acid is in a boat conformation [Prot Struct Funct Genet 14: 327 (1992)]. Our studies seek to determine if structural pre-organization can be achieved through the use of sialyllactones. Determination of whether siallylactones are pre-organized in a binding conformation requires conformational analysis. Our inability to find a systematic study comparing the results obtained by various computational methods for carbohydrate modeling led us to compare two different conformational analysis techniques, four different force fields, and three different solvent models. The computational models were compared based on their ability to reproduce experimental coupling constants for sialic acid, sialyl-1,4-lactone, and sialyl-1,7-lactone derivatives. This study has shown that the MM3 forcefield using the implicit solvent model for water implemented in Macromodel best reproduces the experimental coupling constants. The low-energy conformations generated by this combination of computational methods are pre-organized toward conformations which fit well into the active site of neuraminidase. PMID:9249154

  18. Forced Ignition Study Based On Wavelet Method

    NASA Astrophysics Data System (ADS)

    Martelli, E.; Valorani, M.; Paolucci, S.; Zikoski, Z.

    2011-05-01

    The control of ignition in a rocket engine is a critical problem for combustion chamber design. Therefore it is essential to fully understand the mechanism of ignition during its earliest stages. In this paper the characteristics of flame kernel formation and initial propagation in a hydrogen-argon-oxygen mixing layer are studied using 2D direct numerical simulations with detailed chemistry and transport properties. The flame kernel is initiated by adding an energy deposition source term in the energy equation. The effect of unsteady strain rate is studied by imposing a 2D turbulence velocity field, which is initialized by means of a synthetic field. An adaptive wavelet method, based on interpolating wavelets is used in this study to solve the compressible reactive Navier- Stokes equations. This method provides an alternative means to refine the computational grid points according to local demands of the physical solution. The present simulations show that in the very early instants the kernel perturbed by the turbulent field is characterized by an increased burning area and a slightly increased rad- ical formation. In addition, the calculations show that the wavelet technique yields a significant reduction in the number of degrees of freedom necessary to achieve a pre- scribed solution accuracy.

  19. 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.

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

    SciTech Connect

    Tsai, Yue-Lin Sming; Yuan, Qiang; Huang, Xiaoyuan E-mail: yuanq@ihep.ac.cn

    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. A statistical study of merging galaxies: Theory and observations

    NASA Astrophysics Data System (ADS)

    Chatterjee, Tapan K.

    1990-11-01

    A study of the expected frequency of merging galaxies is conducted, using the impulsive approximation. Results indicate that if we consider mergers involving galaxy pairs without halos in a single crossing time or orbital period, the expected frequency of mergers is two orders of magnitude below the observed value for the present epoch. If we consider mergers involving several orbital periods or crossing times, the expected frequency goes up by an order of magnitude. Preliminary calculation indicate that if we consider galaxy mergers between pairs with massive halos, the merger is very much hastened.

  2. A statistical study of merging galaxies: Theory and observations

    NASA Technical Reports Server (NTRS)

    Chatterjee, Tapan K.

    1990-01-01

    A study of the expected frequency of merging galaxies is conducted, using the impulsive approximation. Results indicate that if we consider mergers involving galaxy pairs without halos in a single crossing time or orbital period, the expected frequency of mergers is two orders of magnitude below the observed value for the present epoch. If we consider mergers involving several orbital periods or crossing times, the expected frequency goes up by an order of magnitude. Preliminary calculation indicate that if we consider galaxy mergers between pairs with massive halos, the merger is very much hastened.

  3. 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.

  4. An observational study of typhoon Imbudo in 2003

    NASA Astrophysics Data System (ADS)

    Li, Qingqing; Fu, Gang; Guo, Jingtian; Yang, Yuqiang; Duan, Yihong

    2005-10-01

    Typhoon Imbudo was a super-typhoon over the northwestern Pacific in 2003. It caused tremendous damage when it made landfalls in the Philippines and China. This paper documents observational analyses of Typhoon Imbudo during its landfall in China. All available observations are used to study its motion, intensity changes, convection, structure and precipitation. Best-track data indicate that Imbudo moved west-northwestward until 1800 UTC 23 July and then turned north-westward. FNL (final) analysis data show that the motion of Imbudo is dominated by changes of the subtropical high. At Imbudo’s mature stage, the minimum sea level pressure dropped to 910 hPa and the maximum sustained winds were as high as 67 m s-1, which is the intensity of a super-typhoon. The surface wind field exhibited asymmetric characteristics. Polar-orbiting satellite imagery also manifested convective asymmetry before Imbudo made landfall in China. Analyzed the vertical wind shear, it is shown that the convection has a downshear-left pattern. All kinds of precipitation data were used to identify the asymmetric characteristic of the rainfall associated with the Imbudo. The maximum rainfalls were located in the southern boundary area between Guangxi and Guangdong. However, the lack of in situ observations limited further analyses of this typhoon.

  5. 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.

  6. CSM research: Methods and application studies

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.

    1989-01-01

    Computational mechanics is that discipline of applied science and engineering devoted to the study of physical phenomena by means of computational methods based on mathematical modeling and simulation, utilizing digital computers. The discipline combines theoretical and applied mechanics, approximation theory, numerical analysis, and computer science. Computational mechanics has had a major impact on engineering analysis and design. When applied to structural mechanics, the discipline is referred to herein as computational structural mechanics. Complex structures being considered by NASA for the 1990's include composite primary aircraft structures and the space station. These structures will be much more difficult to analyze than today's structures and necessitate a major upgrade in computerized structural analysis technology. NASA has initiated a research activity in structural analysis called Computational Structural Mechanics (CSM). The broad objective of the CSM activity is to develop advanced structural analysis technology that will exploit modern and emerging computers, such as those with vector and/or parallel processing capabilities. Here, the current research directions for the Methods and Application Studies Team of the Langley CSM activity are described.

  7. An observational study of entrainment rate in deep convection

    DOE PAGESBeta

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Zhang, Guang Jun; Liu, Yangang

    2015-09-22

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal,more »gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. The entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.« less

  8. An observational study of entrainment rate in deep convection

    SciTech Connect

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Zhang, Guang Jun; Liu, Yangang

    2015-09-22

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal, gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. The entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.

  9. A simple method for correcting spatially resolved solar intensity oscillation observations for variations in scattered light

    NASA Technical Reports Server (NTRS)

    Jefferies, S. M.; Duvall, T. L., Jr.

    1991-01-01

    A measurement of the intensity distribution in an image of the solar disk will be corrupted by a spatial redistribution of the light that is caused by the earth's atmosphere and the observing instrument. A simple correction method is introduced here that is applicable for solar p-mode intensity observations obtained over a period of time in which there is a significant change in the scattering component of the point spread function. The method circumvents the problems incurred with an accurate determination of the spatial point spread function and its subsequent deconvolution from the observations. The method only corrects the spherical harmonic coefficients that represent the spatial frequencies present in the image and does not correct the image itself.

  10. On observation of so-called "water rhythms" by absorption spectroscopy methods

    NASA Astrophysics Data System (ADS)

    Arkhipov, M. V.; Artem'ev, Yu. M.; Belov, S. E.

    2015-10-01

    Experiments on observation of quasiperiodic fluctuations in optical absorption of liquid water (socalled "water rhythms") were reproduced by IR Fourier spectroscopy methods. Slow in time changes in the optical absorption spectra were observed using different Fourier spectrometers with different metrological characteristics. These changes were within the region of experimental accuracy determined by a slow drift in parameters of the measurement equipment. No "water rhythms" were found in our experiments.

  11. 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.

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

    DOEpatents

    Sinha, D.N.; Anthony, B.W.

    1997-02-25

    A method is described 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. 3 figs.

  13. Low Quality Evidence of Epidemiological Observational Studies on Leishmaniasis in Brazil

    PubMed Central

    Trentini, Bruno; Steindel, Mário; Marlow, Mariel A.

    2014-01-01

    Background Brazil has implemented systematic control methods for leishmaniasis for the past 30 years, despite an increase in cases and continued spread of the disease to new regions. A lack high quality evidence from epidemiological observational studies impedes the development of novel control methods to prevent disease transmission among the population. Here, we have evaluated the quality of observational studies on leishmaniasis conducted in Brazil to highlight this issue. Methods/Principal Findings For this systematic review, all publications on leishmaniasis conducted in Brazil from January 1st, 2002 to December 31st, 2012 were screened via Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to select observational studies involving human subjects. The 283 included studies, representing only 14.1% of articles screened, were then further evaluated for quality of epidemiological methods and study design based on the STROBE (Strengthening the Reporting of Observational studies in Epidemiology) checklists. Over half of these studies were descriptive or case reports (53.4%, 151), followed by cross-sectional (20.8%, n?=?59), case-control (8.5%, n?=?24), and cohort (6.0%, n?=?17). Study design was not stated in 46.6% (n?=?181) and incorrectly stated in 17.5% (n?=?24). Comparison groups were utilized in just 39.6% (n?=?112) of the publications, and only 13.4% (n?=?38) employed healthy controls. Majority of studies were performed at the city-level (62.9%, n?=?178), in contrast with two (0.7%) studies performed at the national-level. Coauthorship networks showed the number of author collaborations rapidly decreased after three collaborations, with 70.9% (n?=?659/929) of coauthors publishing only one article during the study period. Conclusions/Significance A review of epidemiological research in Brazil revealed a major lack of quality and evidence. While certain indicators suggested research methods may have improved in the last two years, an emphasis on observational research which employs comparison groups and representative samples is urgently needed. PMID:25197965

  14. Assessing the Impact of Observations on Numerical Weather Forecasts Using the Adjoint Method

    NASA Technical Reports Server (NTRS)

    Gelaro, Ronald

    2012-01-01

    The adjoint of a data assimilation system provides a flexible and efficient tool for estimating observation impacts on short-range weather forecasts. The impacts of any or all observations can be estimated simultaneously based on a single execution of the adjoint system. The results can be easily aggregated according to data type, location, channel, etc., making this technique especially attractive for examining the impacts of new hyper-spectral satellite instruments and for conducting regular, even near-real time, monitoring of the entire observing system. This talk provides a general overview of the adjoint method, including the theoretical basis and practical implementation of the technique. Results are presented from the adjoint-based observation impact monitoring tool in NASA's GEOS-5 global atmospheric data assimilation and forecast system. When performed in conjunction with standard observing system experiments (OSEs), the adjoint results reveal both redundancies and dependencies between observing system impacts as observations are added or removed from the assimilation system. Understanding these dependencies may be important for optimizing the use of the current observational network and defining requirements for future observing systems

  15. An observational study of radiation temperature inversions in Fairbanks, Alaska

    NASA Astrophysics Data System (ADS)

    Malingowski, Julie; Atkinson, David; Fochesatto, Javier; Cherry, Jessica; Stevens, Eric

    2014-03-01

    A series of high resolution radiosonde launches were conducted over seven case-study days spanning spring 2009 and fall/winter 2010 during clear and calm nights at Fairbanks, Alaska to evaluate the effects of solar radiation, snow covered surfaces and low-level winds on the formation and evolution of surface-based temperature inversions (SBI). Transition seasons were selected because strong nighttime radiation cooling allows well-defined inversions to form while sufficient daytime solar heating allows the observation of dissipation processes in the sub-arctic latitudes. During the fall/winter period, co-located Doppler phased array acoustic soundings (SODAR) were carried out. The height of the SBI retrieved by radiosonde and SODAR did not differ more than 50 m. However, the SODAR profiles display a much more complex structure in the atmospheric boundary layer. Observations during this experiment demonstrated that the formation of the SBI is initiated by a rapid cooling at the surface followed by a steady columnar cooling and subsequent growth of the SBI depth overnight.

  16. 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.

  17. 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.

  18. Characterizing Suicide in Toronto: An Observational Study and Cluster Analysis

    PubMed Central

    Sinyor, Mark; Schaffer, Ayal; Streiner, David L

    2014-01-01

    Objective: To determine whether people who have died from suicide in a large epidemiologic sample form clusters based on demographic, clinical, and psychosocial factors. Method: We conducted a coroner’s chart review for 2886 people who died in Toronto, Ontario, from 1998 to 2010, and whose death was ruled as suicide by the Office of the Chief Coroner of Ontario. A cluster analysis using known suicide risk factors was performed to determine whether suicide deaths separate into distinct groups. Clusters were compared according to person- and suicide-specific factors. Results: Five clusters emerged. Cluster 1 had the highest proportion of females and nonviolent methods, and all had depression and a past suicide attempt. Cluster 2 had the highest proportion of people with a recent stressor and violent suicide methods, and all were married. Cluster 3 had mostly males between the ages of 20 and 64, and all had either experienced recent stressors, suffered from mental illness, or had a history of substance abuse. Cluster 4 had the youngest people and the highest proportion of deaths by jumping from height, few were married, and nearly one-half had bipolar disorder or schizophrenia. Cluster 5 had all unmarried people with no prior suicide attempts, and were the least likely to have an identified mental illness and most likely to leave a suicide note. Conclusions: People who die from suicide assort into different patterns of demographic, clinical, and death-specific characteristics. Identifying and studying subgroups of suicides may advance our understanding of the heterogeneous nature of suicide and help to inform development of more targeted suicide prevention strategies. PMID:24444321

  19. 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

  20. 2D vs. 3D mammography observer study

    NASA Astrophysics Data System (ADS)

    Fernandez, James Reza F.; Hovanessian-Larsen, Linda; Liu, Brent

    2011-03-01

    Breast cancer is the most common type of non-skin cancer in women. 2D mammography is a screening tool to aid in the early detection of breast cancer, but has diagnostic limitations of overlapping tissues, especially in dense breasts. 3D mammography has the potential to improve detection outcomes by increasing specificity, and a new 3D screening tool with a 3D display for mammography aims to improve performance and efficiency as compared to 2D mammography. An observer study using a mammography phantom was performed to compare traditional 2D mammography with this ne 3D mammography technique. In comparing 3D and 2D mammography there was no difference in calcification detection, and mass detection was better in 2D as compared to 3D. There was a significant decrease in reading time for masses, calcifications, and normals in 3D compared to 2D, however, as well as more favorable confidence levels in reading normal cases. Given the limitations of the mammography phantom used, however, a clearer picture in comparing 3D and 2D mammography may be better acquired with the incorporation of human studies in the future.

  1. Observational Study of Contracts Processing at 29 CTSA Sites

    PubMed Central

    Kiriakis, James; Gaich, Nicholas; Johnston, S Claiborne; Kitterman, Darlene; Rosenblum, Daniel; Salberg, Libby; Rifkind, Adam

    2013-01-01

    We measured contracts Final Negotiation (FN) and Full Execution (FE) times using shared definitions in a prospective observational study of management of contracts for clinical trials at 29 CTSA institutions. Median FN and FE times were reached in 39 and 91 days, respectively; mean times for FN and FE were 55 and 103 days, respectively. Individual site medians ranged from 3 to 116 days for FN and 34 to 197 days for FE. The use of Master Agreements (MAs) and Previously Negotiated Terms (PNTs) was associated with significant reduction of FN times by a mean of 33 days (p<0) and 22 days (p<0.001), respectively. PNTs, but not MAs, were associated with significantly reduced FE time (22 days, p<.007). Gap analysis revealed a gap of 22 days between contracts negotiation and Institutional Review Board (IRB) review and intervals of 33 days (contracts) and 48 days (IRB review) during which the process steps were being conducted alone, suggesting a potential benefit with parallel processing. These baseline data support a plan to investigate root causes of prolonged study startup time by examining causes of variation and outliers. PMID:23919362

  2. An Observational Study of Pulsations in Proto-Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Hrivnak, Bruce J.; Lu, Wenxian; Henson, Gary D.; Hillwig, Todd C.

    2016-01-01

    We have been carrying out a long-term monitoring program to study the light variability in proto-planetary nebulae (PPNe). PPNe are post-Asymptotic Giant Branch objects in transition between the AGB and PN phases in the evolution of low and intermediate-mass stars. As such, it is not surprising that they display pulsational variability. We have been carrying out photometric monitoring of 30 of these at the Valparaiso University campus observatory over the last 20 years, with the assistance of undergraduate students. The sample size has been enlarged over the past six years by observations made using telescopes in the SARA consortium at KPNO and CTIO. Periods have been determined for those of F-G spectral types. We have also enlarged the sample with PPNe from outside the Milky Way by determining periods of eight PPNe in the lower metalicity environment of the Magellanic Clouds. Periods for the entire sample range from 35 to 160 days. Some clear patterns have emerged, with those of higher temperature possessing shorter periods and smaller amplitudes, indicating a reduction in period and pulsation amplitude as the objects evolve. Radial velocity monitoring of several of the brightest of these has allowed us to document their changes in brightness, color, and size during a pulsation cycle. The results of this study will be presented. This research is supported by grants from the National Science Foundation (most recently AST 1413660), with additional student support from the Indiana Space Grant Consortium.

  3. Observational study of contracts processing at 29 CTSA sites.

    PubMed

    Kiriakis, James; Gaich, Nicholas; Johnston, S Claiborne; Kitterman, Darlene; Rosenblum, Daniel; Salberg, Libby; Rifkind, Adam

    2013-08-01

    We measured contracts final negotiation (FN) and full execution (FE) times using shared definitions in a prospective observational study of management of contracts for clinical trials at 29 CTSA institutions. Median FN and FE times were reached in 39 and 91 days, respectively; mean times for FN and FE were 55 and 103 days, respectively. Individual site medians ranged from 3 to 116 days for FN and 34 to 197 days for FE. The use of master agreements (MAs) and previously negotiated terms (PNTs) was associated with significant reduction of FN times by a mean of 33 days (p < 0) and 22 days (p < 0.001), respectively. PNTs, but not MAs, were associated with significantly reduced FE time (22 days, p < 0.007). Gap analysis revealed a gap of 22 days between contracts negotiation and Institutional Review Board (IRB) review and intervals of 33 days (contracts) and 48 days (IRB review) during which the process steps were being conducted alone, suggesting a potential benefit with parallel processing. These baseline data support a plan to investigate root causes of prolonged study start-up time by examining causes of variation and outliers. PMID:23919362

  4. Physician spending and subsequent risk of malpractice claims: observational study

    PubMed Central

    Schoemaker, Lena; Bhattacharya, Jay; Seabury, Seth A

    2015-01-01

    Study question Is a higher use of resources by physicians associated with a reduced risk of malpractice claims? Methods Using data on nearly all admissions to acute care hospitals in Florida during 2000-09 linked to malpractice history of the attending physician, this study investigated whether physicians in seven specialties with higher average hospital charges in a year were less likely to face an allegation of malpractice in the following year, adjusting for patient characteristics, comorbidities, and diagnosis. To provide clinical context, the study focused on obstetrics, where the choice of caesarean deliveries are suggested to be influenced by defensive medicine, and whether obstetricians with higher adjusted caesarean rates in a year had fewer alleged malpractice incidents the following year. Study answer and limitations The data included 24?637 physicians, 154?725 physician years, and 18?352?391 hospital admissions; 4342 malpractice claims were made against physicians (2.8% per physician year). Across specialties, greater average spending by physicians was associated with reduced risk of incurring a malpractice claim. For example, among internists, the probability of experiencing an alleged malpractice incident in the following year ranged from 1.5% (95% confidence interval 1.2% to 1.7%) in the bottom spending fifth ($19?725 (£12?800; €17?400) per hospital admission) to 0.3% (0.2% to 0.5%) in the top fifth ($39?379 per hospital admission). In six of the specialties, a greater use of resources was associated with statistically significantly lower subsequent rates of alleged malpractice incidents. A principal limitation of this study is that information on illness severity was lacking. It is also uncertain whether higher spending is defensively motivated. What this study adds Within specialty and after adjustment for patient characteristics, higher resource use by physicians is associated with fewer malpractice claims. Funding, competing interests, data sharing This study was supported by the Office of the Director, National Institutes of Health (grant 1DP5OD017897-01 to ABJ) and National Institute of Aging (R37 AG036791 to JB). The authors have no competing interests or additional data to share. PMID:26538498

  5. Coordination and management of multicenter clinical studies in trauma: Experience from the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study

    PubMed Central

    Rahbar, Mohammad H.; Fox, Erin E.; del Junco, Deborah J.; Cotton, Bryan A.; Podbielski, Jeanette M.; Matijevic, Nena; Cohen, Mitchell J.; Schreiber, Martin A.; Zhang, Jiajie; Mirhaji, Parsa; Duran, Sarah; Reynolds, Robert J.; Benjamin-Garner, Ruby; Holcomb, John B.

    2011-01-01

    Aim Early death due to hemorrhage is a major consequence of traumatic injury. Transfusion practices differ among hospitals and it is unknown which transfusion practices improve survival. This report describes the experience of the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study Data Coordination Center in designing and coordinating a study to examine transfusion practices at ten Level 1 trauma centers in the U.S. Methods PROMMTT was a multisite prospective observational study of severely injured transfused trauma patients. The clinical sites collected real-time information on the timing and amounts of blood product infusions as well as colloids and crystalloids, vital signs, initial diagnostic and clinical laboratory tests, life saving interventions and other clinical care data. Results Between July 2009 and October 2010, PROMMTT screened 12,561 trauma admissions and enrolled 1,245 patients who received one or more blood transfusions within 6 hours of ED admission. A total of 297 massive transfusions were observed over the course of the study at a combined rate of 5.0 massive transfusion patients/week. Conclusion PROMMTT is the first multisite study to collect real-time prospective data on trauma patients requiring transfusion. Support from the Department of Defense and collaborative expertise from the ten participating centers helped to demonstrate the feasibility of prospective trauma transfusion studies. The observational data collected from this study will be an invaluable resource for research in trauma surgery and it will guide the design and conduct of future randomized trials. PMID:22001613

  6. 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.

  7. 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.

  8. Study report on a double isotope method of calcium absorption

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Some of the pros and cons of three methods to study gastrointestinal calcium absorption are briefly discussed. The methods are: (1) a balance study; (2) a single isotope method; and (3) a double isotope method. A procedure for the double isotope method is also included.

  9. 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.

  10. Can headache impair intellectual abilities in children? An observational study

    PubMed Central

    Esposito, Maria; Pascotto, Antonio; Gallai, Beatrice; Parisi, Lucia; Roccella, Michele; Marotta, Rosa; Lavano, Serena Marianna; Gritti, Antonella; Mazzotta, Giovanni; Carotenuto, Marco

    2012-01-01

    Background The purpose of this study was to assess the cognitive functioning of children affected by headache, pinpointing the differences in intelligence style between subjects affected by migraine without aura and subjects with tension-type headache. Methods The study population consisted of 147 children (mean age 10.82 ± 2.17 years) with headache, recruited from the Headache Center for Developmental Age, Child and Adolescent Neuropsychiatry Clinic, Second University of Naples. Cognitive profiling was performed using Weschler Intelligence Scale for Children Third Edition throughout the sample. According to the International Classification of Headache Disorders II criteria for pediatric age, subjects were divided into a migraine without aura group (n = 75; 43 boys, 32 girls) and a tension-type headache group (n = 72; 49 boys, 23 girls). The results were compared with the findings obtained from a sample of 137 healthy control subjects recruited from schools in the Campania region, matched for age and gender. Results No difference in full intelligence quotient was found between the groups, but the children with tension-type headache had a lower verbal intelligence quotient and a higher performance intelligence quotient than the healthy controls and children with migraine. Factor analysis data showed that the children with migraine seemed to have lower perceptual organization than the children affected by tension-type headache. Conclusion To our knowledge, studies on cognitive functioning in children affected by headache in the interictal phase are scarce, and our results suggest a new perspective in understanding of the neuropsychological aspects of young patients affected by headaches. PMID:23139628

  11. 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

  12. 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.

  13. A Mixed Methods Sampling Methodology for a Multisite Case Study

    ERIC Educational Resources Information Center

    Sharp, Julia L.; Mobley, Catherine; Hammond, Cathy; Withington, Cairen; Drew, Sam; Stringfield, Sam; Stipanovic, Natalie

    2012-01-01

    The flexibility of mixed methods research strategies makes such approaches especially suitable for multisite case studies. Yet the utilization of mixed methods to select sites for these studies is rarely reported. The authors describe their pragmatic mixed methods approach to select a sample for their multisite mixed methods case study of a…

  14. Analytic Perturbation Method for Estimating Ground Flash Fraction from Satellite Lightning Observations

    NASA Technical Reports Server (NTRS)

    Koshak, William; Solakiewicz, Richard

    2013-01-01

    An analytic perturbation method is introduced for estimating the lightning ground flash fraction in a set of N lightning flashes observed by a satellite lightning mapper. The value of N is large, typically in the thousands, and the observations consist of the maximum optical group area produced by each flash. The method is tested using simulated observations that are based on Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) data. National Lightning Detection NetworkTM (NLDN) data is used to determine the flash-type (ground or cloud) of the satellite-observed flashes, and provides the ground flash fraction truth for the simulation runs. It is found that the mean ground flash fraction retrieval errors are below 0.04 across the full range 0-1 under certain simulation conditions. In general, it is demonstrated that the retrieval errors depend on many factors (i.e., the number, N, of satellite observations, the magnitude of random and systematic measurement errors, and the number of samples used to form certain climate distributions employed in the model).

  15. Endotoxin Elimination in Patients with Septic Shock: An Observation Study.

    PubMed

    Adamik, Barbara; Zielinski, Stanislaw; Smiechowicz, Jakub; Kübler, Andrzej

    2015-12-01

    To evaluate the effectiveness of endotoxin elimination with an adsorption column in patients with septic shock and endotoxemia. The elimination therapy was guided by a new bedside method of measuring endotoxin activity (EA). Intensive care unit (ICU) patients with septic shock and suspected Gram-negative infection were consecutively added to the study group within the first 24 h. Endotoxin elimination was performed using hemoperfusion with the Alteco LPS Adsorber. The primary endpoint was improvement in organ function within the first 24 h of treatment. A secondary objective was to assess the usefulness of a new method of measuring EA to help guide endotoxin elimination therapy. Out of 64 patients 18 had a high baseline EA [0.70 EA units (0.66-0.77)]. Those patients had endotoxin elimination treatment in addition to conventional medical therapy. At 24 h after endotoxin elimination, the EA had decreased to 0.56 EA units (0.43-0.77), (p = 0.005); MAP increased from 69 (62-80) to 80 mm Hg (68-88), (p = 0.002), and noradrenaline use decreased from 0.28 (0.15-0.80) to 0.1 ?g/kg/min (0.00-0.70) at the same time (p = 0.04). The SOFA score had decreased from 11 (9-15) to 9 (7-14) points 24 h after endotoxin elimination (p = 0.01) with a median delta SOFA -2 points. Endotoxin elimination did not have a significant effect on the ICU length of stay or ICU mortality. Effective endotoxin elimination resulted in a significant improvement in hemodynamic parameters and of organ function. The application of the EA assay was useful for the bedside monitoring of endotoxemia in critically ill ICU patients. PMID:26093653

  16. Microtremors study applying the SPAC method in Colima state, Mexico.

    NASA Astrophysics Data System (ADS)

    Vázquez Rosas, R.; Aguirre González, J.; Mijares Arellano, H.

    2007-05-01

    One of the main parts of seismic risk studies is to determine the site effect. This can be estimated by means of the microtremors measurements. From the H/V spectral ratio (Nakamura, 1989), the predominant period of the site can be estimated. Although the predominant period by itself can not represent the site effect in a wide range of frequencies and doesn't provide information of the stratigraphy. The SPAC method (Spatial Auto-Correlation Method, Aki 1957), on the other hand, is useful to estimate the stratigraphy of the site. It is based on the simultaneous recording of microtremors in several stations deployed in an instrumental array. Through the spatial autocorrelation coefficient computation, the Rayleigh wave dispersion curve can be cleared. Finally the stratigraphy model (thickness, S and P wave velocity, and density of each layer) is estimated by fitting the theoretical dispersion curve with the observed one. The theoretical dispersion curve is initially computed using a proposed model. That model is modified several times until the theoretical curve fit the observations. This method requires of a minimum of three stations where the microtremors are observed simultaneously in all the stations. We applied the SPAC method to six sites in Colima state, Mexico. Those sites are Santa Barbara, Cerro de Ortega, Tecoman, Manzanillo and two in Colima city. Totally 16 arrays were carried out using equilateral triangles with different apertures with a minimum of 5 m and a maximum of 60 m. For recording microtremors we used short period (5 seconds) velocity type vertical sensors connected to a K2 (Kinemetrics) acquisition system. We could estimate the velocities of the most superficial layers reaching different depths in each site. For Santa Bárbara site the exploration depth was about 30 m, for Tecoman 12 m, for Manzanillo 35 m, for Cerro de Ortega 68 m, and the deepest site exploration was obtained in Colima city with a depth of around 73 m. The S wave velocities fluctuate between 230 m/s and 420 m/s for the most superficial layer. It means that, in general, the most superficial layers are quite competent. The superficial layer with smaller S wave velocity was observed in Tecoman, while that of largest S wave velocity was observed in Cerro de Ortega. Our estimations are consistent with down-hole velocity records obtained in Santa Barbara by previous studies.

  17. Studies of Accreting Neutron Stars with RXTE Cycle 4 Observations: II: Too Observations of Transient LMXBs

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    2002-01-01

    NASA Grant NAG 5-9045 provided funds for the research project 'TOO Observations of Transient LMxBs' approved under the Rossi X-ray Timing Explorer (RXTE) Guest Observer Program Cycle 4 and funded under the 1999 NASA Astrophysics Data Program. The principal investigator of the observing time proposal was Dr. M. Mendez (U. of Amsterdam). The grant was funded for one year beginning 3/1/2000. The original proposal was submitted by Prof. Jan van Paradijs, who passed away in 1999 before the funds were distributed. Prof. William S. Pauesas administered the grant during the period of performance. In spite of a wealth of observational data on the kHz QPO in low-mass X-ray binaries (LMXBs), the interpretation of this phenomenon is currently uncertain because the pairs of kHz QPO peaks and the oscillations seen in some Type I X-ray bursts are almost, but not quite, connected by a simple beat frequency relation. The proposal was intended to contribute to a solution to this confusion by making RXTE target-of-opportunity observations of two transient LMXBs, Aql X-1 and 4U 1608-52, if the sources became sufficiently bright.

  18. 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.

  19. Photographic zenith tube of the Zvenigorod INASAN Observatory - Processing method and observation results

    NASA Astrophysics Data System (ADS)

    Yurov, E. A.

    1992-10-01

    A method for the reduction of PZT plates which has been used at the Zvenigorod INASAN Observatory since 1986 is described. The formulas used for computing the coordinates of the stellar image in the focal plane at the midpoint of the exposure are correct to 0.0024 arcsec. Observations from February 1986 to October 1988 are compared with data of BIH and IERS, and the results of the comparison are used to compute the amplitudes of the annual terms of nonpolar variations in the observed latitudes and Delta(UTI).

  20. Four Methods for Determining Intermediate Perturbed Orbits from Three Observations: A Comparison

    NASA Astrophysics Data System (ADS)

    Shefer, V. A.

    2015-03-01

    Theoretical and numerical comparison of four methods for determining the orbit of a small celestial body from three measurements of its angular coordinates at three time moments is provided. The methods are intended for constructing intermediate orbits considering most of perturbations in motion of the examined body. Two methods are based on the solutions of the differential equations of motion and on their second derivatives in the form of series in terms of powers of time intervals (the Herrick-Gibbs approach), and the two others are based on the solutions for some intermediate perturbed motions in the closed form, without their representation in the form of series (the approach of the author). A dependence of methodic errors on the length of the reference time interval determined by the moments of observation beginning and ending is investigated. By way of examples, results of calculation of the orbit of the Apophis asteroid are presented.

  1. Intra- and inter-observer reliability of the Cobb measurement by chiropractic interns using digital evaluation methods

    PubMed Central

    Cracknell, Jesse; Lawson, Douglas M.; Taylor, John A.

    2015-01-01

    Introduction: It is important to create a body of evidence surrounding the reliability of certain diagnostic criteria. While the reliability of the Cobb measurement is well established with various licensed health care professionals, this study aims to determine the inter- and intra-observer reliability of the Cobb Measurement among chiropractic interns. Methods: Fourteen chiropractic interns analyzed 10 pre-selected digital spinal radiographs on a Picture Archiving and Communication System (PACS) in two separate rounds of observation. The participants indicated their choice of end vertebra and Cobb Measurement in each round of observation. Agreement on vertebral levels selected was estimated using percentage agreement. Intra-observer reliability was estimated using the Pearson r correlation coefficient, and inter-observer correlation was estimated using the Inter-Class Coefficient (ICC). Results: The range of percentage agreement on vertebral level selection was 0.36 – 0.79. The Pearson r correlation coefficient for round 1 and round 2 was 0.79. The ICC (3,1) was 0.79 (round 1), and 0.70 (round 2). Conclusion: Less than optimal agreement on end vertebrae selection was found between observers. Intra- and inter-observer reliability of the Cobb Measurement was ‘excellent’ (round 1) and ‘good’ (round 2). PMID:26500360

  2. Computing observables in curved multifield models of inflation - A guide (with code) to the transport method

    E-print Network

    Mafalda Dias; Jonathan Frazer; David Seery

    2015-07-03

    We describe how to apply the transport method to compute inflationary observables in a broad range of multiple-field models. The method is efficient and encompasses scenarios with curved field-space metrics, violations of slow-roll conditions and turns of the trajectory in field space. It can be used for an arbitrary mass spectrum, including massive modes and models with quasi-single-field dynamics. In this note we focus on practical issues. It is accompanied by a Mathematica code which can be used to explore suitable models, or as a basis for further development.

  3. AN EVALUATION STUDY OF EPA METHOD 8

    EPA Science Inventory

    Techniques used in EPA Method 8, the source test method for acid mist and sulfur dioxide emissions from sulfuric acid plants, have been evaluated. Evidence is shown that trace amounts of peroxides in isopropyl alcohol result in the conversion of sulfur dioxide to sulfate and caus...

  4. A Study of Student Teaching Using Direct Observation.

    ERIC Educational Resources Information Center

    Coker, Joan G.; Coker, Homer

    Thirty-three student teachers were observed in elementary school classrooms to determine if they manifested 16 interactive behaviors identified as desirable by college of education faculty. Teaching assistants used the Georgia Assessment of Teaching Effectiveness (GATE), an instrument which requires the observers to objectively record, but not…

  5. Motor facilitation during action observation: a magnetic stimulation study.

    PubMed

    Fadiga, L; Fogassi, L; Pavesi, G; Rizzolatti, G

    1995-06-01

    1. We stimulated the motor cortex of normal subjects (transcranial magnetic stimulation) while they 1) observed an experimenter grasping 3D-objects, 2) looked at the same 3D-objects, 3) observed an experimenter tracing geometrical figures in the air with his arm, and 4) detected the dimming of a light. Motor evoked potentials (MEPs) were recorded from hand muscles. 2. We found that MEPs significantly increased during the conditions in which subjects observed movements. The MEP pattern reflected the pattern of muscle activity recorded when the subjects executed the observed actions. 3. We conclude that in humans there is a system matching action observation and execution. This system resembles the one recently described in the monkey. PMID:7666169

  6. Innovative research methods for studying treatments for rare diseases: methodological review

    PubMed Central

    Thompson, Lauren; O’Keefe, Kelly; Kesselheim, Aaron S

    2014-01-01

    Objective To examine methods for generating evidence on health outcomes in patients with rare diseases. Design Methodological review of existing literature. Setting PubMed, Embase, and Academic Search Premier searched for articles describing innovative approaches to randomized trial design and analysis methods and methods for conducting observational research in patients with rare diseases. Main outcome measures We assessed information related to the proposed methods, the specific rare disease being studied, and outcomes from the application of the methods. We summarize methods with respect to their advantages in studying health outcomes in rare diseases and provide examples of their application. Results We identified 46 articles that proposed or described methods for studying patient health outcomes in rare diseases. Articles covered a wide range of rare diseases and most (72%) were published in 2008 or later. We identified 16 research strategies for studying rare disease. Innovative clinical trial methods minimize sample size requirements (n=4) and maximize the proportion of patients who receive active treatment (n=2), strategies crucial to studying small populations of patients with limited treatment choices. No studies describing unique methods for conducting observational studies in patients with rare diseases were identified. Conclusions Though numerous studies apply unique clinical trial designs and considerations to assess patient health outcomes in rare diseases, less attention has been paid to innovative methods for studying rare diseases using observational data. PMID:25422272

  7. Incorporating Animals in Phenological Assessments: USA National Phenology Network Methods to Observe Animal Phenology

    NASA Astrophysics Data System (ADS)

    Miller-Rushing, A. J.; Weltzin, J. F.

    2009-12-01

    Many assessments of phenology, particularly those operating at large scales, focus on the phenology of plants, in part because of the relevance of plants in cycles of leaf greening and browning that are visible from satellite-based remote sensing, and because plants contribute significantly to global and regional biogeochemical cycles. The USA National Phenology Network (USA-NPN), a consortium of individuals, agencies, and organizations, promotes integrated assessments of both plant and animal phenology. The network is currently developing standard methods to add animal phenology to existing assessments of plant phenology. The first phase will of the standard methods will be implemented online in spring 2010. The methods for observing animals will be similar to the standard methods for making on-the-ground observations of plants—observers will be asked to monitor a fixed location regularly throughout the year. During each visit, observers will answer a series of “yes-no” questions that address the phenological state of the species of interest: Is the species present? Is it mating? Is it feeding? And so on. We are currently testing this method in several national parks in the northeastern United States, including Acadia National Park and the Appalachian Trail. By collecting new observations of this sort for a range of animals—amphibians, birds, fish, insects, mammals, and reptiles—we will greatly increase the ability of scientists and natural resource managers to understand how temporal relationships among these species and the plants on which they depend may be changing. To bolster the data available, we are collaborating with existing monitoring programs to develop common monitoring techniques, data sharing technologies, and visualizations. We are also beginning to collect legacy datasets, such as one from North American Bird Phenology Program that includes 90 years of observations of bird migration times from across the continent. We believe that increasing the amount of animal phenology data available for scientists, natural resource managers, and educators, will greatly advance our understanding of phenological changes and their causes and consequences, particularly in this time of rapid environmental change.

  8. Observational Studies on Evaluating the Safety and Adverse Effects of Traditional Chinese Medicine

    PubMed Central

    Tang, Jin-Ling; Wang, Jung-Der

    2013-01-01

    Background. This study aims to share our experiences when carrying out observational studies of traditional Chinese medicine (TCM). Methods. We have proactively monitored the safety profiles of Duhuo Jisheng Tang (DJT), Suan Zao Ren Tang (SZRT), and TMN-1. A list of adverse events (AEs), complete blood counts, and liver and kidney function tests were obtained from the participants during their scheduled hospital visits. Retrospective observational studies were conducted based on the reimbursement database of the National Health Insurance system, Taiwan, to explore the relationship between the use of TCM that have been adulterated by aristolochic acid and the risk from both nephrotoxins and carcinogens. Results. A total of 221, 287, and 203 AEs were detected after SZRT, DJT, and TMN-1 had been taken, respectively. Dizziness, headache, stomach ache, and diarrhea were judged to be probably related to SZRT treatment. Retrospective observational studies found an association between the consumption of aristolochic acid-containing Chinese formulae such as Mu Tong and an increased risk of CKD, ESRD, and urinary tract cancer. Conclusion. Prospective and retrospective observational studies seem to have specific advantages when investigating the safety and adverse effects of TCM therapies, as well as possibly other alternative/complementary therapies. PMID:24159351

  9. Epidemiology, quality and reporting characteristics of meta-analyses of observational studies published in Chinese journals

    PubMed Central

    Zhang, Zhe-wen; Cheng, Juan; Liu, Zhuan; Ma, Ji-chun; Li, Jin-long; Wang, Jing; Yang, Ke-hu

    2015-01-01

    Objective The aim of this study was to examine the epidemiological and reporting characteristics as well as the methodological quality of meta-analyses (MAs) of observational studies published in Chinese journals. Methods 5 Chinese databases were searched for MAs of observational studies published from January 1978 to May 2014. Data were extracted into Excel spreadsheets, and Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Assessment of Multiple Systematic Reviews (AMSTAR) checklists were used to assess reporting characteristics and methodological quality, respectively. Results A total of 607 MAs were included. Only 52.2% of the MAs assessed the quality of the included primary studies, and the retrieval information was not comprehensive in more than half (85.8%) of the MAs. In addition, 50 (8.2%) MAs did not search any Chinese databases, while 126 (20.8%) studies did not search any English databases. Approximately 41.2% of the MAs did not describe the statistical methods in sufficient details, and most (95.5%) MAs did not report on conflicts of interest. However, compared with the before publication of the MOOSE Checklist, the quality of reporting improved significantly for 20 subitems after publication of the MOOSE Checklist, and 7 items of the included MAs demonstrated significant improvement after publication of the AMSTAR Checklist (p<0.05). Conclusions Although many MAs of observational studies have been published in Chinese journals, the reporting quality is questionable. Thus, there is an urgent need to increase the use of reporting guidelines and methodological tools in China; we recommend that Chinese journals adopt the MOOSE and AMSTAR criteria. PMID:26644119

  10. An Observational Study for Evaluating the Effects of Interpersonal Problem-Solving Skills Training on Behavioural Dimensions

    ERIC Educational Resources Information Center

    Anliak, Sakire; Sahin, Derya

    2010-01-01

    The present observational study was designed to evaluate the effectiveness of the I Can Problem Solve (ICPS) programme on behavioural change from aggression to pro-social behaviours by using the DECB rating scale. Non-participant observation method was used to collect data in pretest-training-posttest design. It was hypothesised that the ICPS…

  11. 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.

  12. 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.

  13. Improving Resolution and Depth of Astronomical Observations via Modern Mathematical Methods for Image Analysis

    NASA Astrophysics Data System (ADS)

    Castellano, M.; Ottaviani, D.; Fontana, A.; Merlin, E.; Pilo, S.; Falcone, M.

    2015-09-01

    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.

  14. 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.

  15. 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

  16. An Investigation of the SOAR Study Method

    ERIC Educational Resources Information Center

    Jairam, Dharma; Kiewra, Kenneth A.

    2009-01-01

    Students are rarely taught how to study. When study strategy instruction occurs, weak strategies are often advocated or strategies are presented in a hodgepodge leaving students without a systematic study plan. This experiment investigated a systematic study plan called SOAR that includes the components of "S"election, "O"rganization,…

  17. Method to Rapidly Collect Thousands of Velocity Observations to Validate Million-Element 2D Hydrodynamic Models

    NASA Astrophysics Data System (ADS)

    Barker, J. R.; Pasternack, G. B.; Bratovich, P.; Massa, D.; Reedy, G.; Johnson, T.

    2010-12-01

    Two-dimensional (depth-averaged) hydrodynamic models have existed for decades and are used to study a variety of hydrogeomorphic processes as well as to design river rehabilitation projects. Rapid computer and coding advances are revolutionizing the size and detail of 2D models. Meanwhile, advances in topo mapping and environmental informatics are providing the data inputs to drive large, detailed simulations. Million-element computational meshes are in hand. With simulations of this size and detail, the primary challenge has shifted to finding rapid and inexpensive means for testing model predictions against observations. Standard methods for collecting velocity data include boat-mounted ADCP and point-based sensors on boats or wading rods. These methods are labor intensive and often limited to a narrow flow range. Also, they generate small datasets at a few cross-sections, which is inadequate to characterize the statistical structure of the relation between predictions and observations. Drawing on the long-standing oceanographic method of using drogues to track water currents, previous studies have demonstrated the potential of small dGPS units to obtain surface velocity in rivers. However, dGPS is too inaccurate to test 2D models. Also, there is financial risk in losing drogues in rough currents. In this study, an RTK GPS unit was mounted onto a manned whitewater kayak. The boater positioned himself into the current and used floating debris to maintain a speed and heading consistent with the ambient surface flow field. RTK GPS measurements were taken ever 5 sec. From these positions, a 2D velocity vector was obtained. The method was tested over ~20 km of the lower Yuba River in California in flows ranging from 500-5000 cfs, yielding 5816 observations. To compare velocity magnitude against the 2D model-predicted depth-averaged value, kayak-based surface values were scaled down by an optimized constant (0.72), which had no negative effect on regression analysis. The r2 value for speed was 0.78 by this method, compared with 0.57 based on 199 points from traditional measurements. The r2 value for velocity direction was 0.77. Although it is not ideal to rely on observed surface velocity to evaluate depth-average velocity predictions, all available velocity-measurement methods have a suite of assumptions and complications. Using this method, the availability of 10-100x more data was so beneficial that the outcome was among the highest model performance outcomes reported in the literature.

  18. The Reporting of Observational Clinical Functional Magnetic Resonance Imaging Studies: A Systematic Review

    PubMed Central

    Guo, Qing; Parlar, Melissa; Truong, Wanda; Hall, Geoffrey; Thabane, Lehana; McKinnon, Margaret; Goeree, Ron; Pullenayegum, Eleanor

    2014-01-01

    Introduction Complete reporting assists readers in confirming the methodological rigor and validity of findings and allows replication. The reporting quality of observational functional magnetic resonance imaging (fMRI) studies involving clinical participants is unclear. Objectives We sought to determine the quality of reporting in observational fMRI studies involving clinical participants. Methods We searched OVID MEDLINE for fMRI studies in six leading journals between January 2010 and December 2011.Three independent reviewers abstracted data from articles using an 83-item checklist adapted from the guidelines proposed by Poldrack et al. (Neuroimage 2008; 40: 409–14). We calculated the percentage of articles reporting each item of the checklist and the percentage of reported items per article. Results A random sample of 100 eligible articles was included in the study. Thirty-one items were reported by fewer than 50% of the articles and 13 items were reported by fewer than 20% of the articles. The median percentage of reported items per article was 51% (ranging from 30% to 78%). Although most articles reported statistical methods for within-subject modeling (92%) and for between-subject group modeling (97%), none of the articles reported observed effect sizes for any negative finding (0%). Few articles reported justifications for fixed-effect inferences used for group modeling (3%) and temporal autocorrelations used to account for within-subject variances and correlations (18%). Other under-reported areas included whether and how the task design was optimized for efficiency (22%) and distributions of inter-trial intervals (23%). Conclusions This study indicates that substantial improvement in the reporting of observational clinical fMRI studies is required. Poldrack et al.'s guidelines provide a means of improving overall reporting quality. Nonetheless, these guidelines are lengthy and may be at odds with strict word limits for publication; creation of a shortened-version of Poldrack's checklist that contains the most relevant items may be useful in this regard. PMID:24755843

  19. Research on a UAV path planning method for ground observation based on threat sources

    NASA Astrophysics Data System (ADS)

    Yan, Hao; Fan, Xing; Xia, Xuezhi; Lin, Linshu

    2008-12-01

    The path planning method is one of the main research directions in current UAV(unmanned aerial vehicle) technologies. In this paper we perform analyses on the adversarial environment which may be broken through during the UAV mission for ground observation, and carry out the grade classification according to the threat level. On the basis of genetic algorithm, the encoding method of dimension reduction and direct quantization is used to combine the threat value of each leg with the flight distance, so as to construct the fitness evaluation function based on the threat amount and design the algorithm. This method is proven to be able to converge effectively and quickly via the simulation experiments, which meet the threat restriction and applicability of UAV in route planning.

  20. A method of high-accuracy orbit determination from three observations of a small celestial body. (Russian Title: ????? ????????????? ??????????? ?????? ?? ???? ??????????? ?????? ????????? ????)

    NASA Astrophysics Data System (ADS)

    Shefer, V. A.

    2009-11-01

    A new method is suggested for finding the preliminary orbit of a small celestial body from its three pairs of angular measurements at three times. The method uses the intermediate orbit that we previously constructed from three position vectors and the corresponding times. This intermediate orbit allows for most of the perturbations in the motion of the body under study. The methodical error of orbit computation by the proposed method is generally three orders smaller than the corresponding error of the traditional approach based on the construction of the unperturbed Keplerian orbit. This fact allows such a reference arc to be selected that the accuracy of the intermediate orbit would always match that of the reference observations that determine this arc. The new method is a highly efficient tool, which allows reliable parameters of the perturbed motion to be obtained already at the stage of computing the preliminary orbit. It is especially efficient if applied to high-accuracy observational data covering short orbital arcs.

  1. Studying Aerosol Properties with Astronomical Observations Using a Scattered Moonlight Model

    NASA Astrophysics Data System (ADS)

    Jones, Amy; Noll, Stefan; Kausch, Wolfgang; Szyszka, Cezary; Kimeswenger, Stefan

    2013-04-01

    We are developing a new technique for monitoring the atmosphere with astronomical observations and our scattered moonlight model. This could be used to determine the size distributions and amounts of various aerosol particles. By taking the Moon as an illuminating source in sky observations, it is possible to iteratively find aerosol properties for a given time and location. There is a wealth of astronomical data over the last decade taken at Cerro Paranal in Chile where this technique can be applied. Our advanced scattered moonlight model is part of a sky radiance and transmission model developed for the Very Large Telescope of the European Southern Observatory. The moon model can calculate the amount of scattered moonlight present in a given astronomical observation based on the positions of the Moon and target, lunar phase, and atmospheric properties. This model is more physical than previous works in astronomy, which were almost completely empirical. For the original astronomical purpose, the model uses typical size distributions of remote continental tropospheric and stratospheric aerosols and the measured extinction curve from standard star observations to calculate the scattering and absorption of the moonlight to determine the amount of light that would eventually arrive to the telescope. Because the model incorporates the properties of the aerosols, in principle we can use this model with sky background observations to find the aerosol composition. The sky observations would first need to be analysed with our full sky model to calculate the other sky background components, and a derived extinction curve from standard star observations. Then with our moon model we could iteratively find the best aerosol composition for the data. This would require optical and near infrared spectra for an unique, optimized solution. This technique for studying aerosol properties would provide data from a new perspective. The investigated aerosols would be nocturnal, from a remote location in the Chilean desert, and this method could be extended into the past decade and other locations. Most current methods use the Sun as the illuminating source to study the aerosols and so with this new nocturnal data set one could compare the two types. Additionally, the aerosols near the observatory are not dominated by local pollution sources and the background aerosols can be better studied. Also, the observatory has been operational for over a decade, and the aerosol data set could be extended into the past, as well as the model can be modified so the technique could be applied to other observatories around the globe. This new method for determining aerosol properties from astronomical observations with our scattered moonlight model could be a promising tool for atmospheric science.

  2. Developing Best Practices Teaching Procedures for Skinfold Assessment: Observational Examination Using the Think Aloud Method

    ERIC Educational Resources Information Center

    Holmstrup, Michael E.; Verba, Steven D.; Lynn, Jeffrey S.

    2015-01-01

    Skinfold assessment is valid and economical; however, it has a steep learning curve, and many programs only include one exposure to the technique. Increasing the number of exposures to skinfold assessment within an undergraduate curriculum would likely increase skill proficiency. The present study combined observational and Think Aloud…

  3. Children's Social and Emotional Competence in Head Start Classrooms: Observational Methods.

    ERIC Educational Resources Information Center

    Miller, Alison L.; Gouley, Kathleen K.; Shields, Ann; Seifer, Ronald; Dickstein, Susan; Fox, Christina; Radtke, Heather

    Noting that low-income children are at risk for early school difficulties and that social and emotional competencies are hypothesized to be crucial for early school success, this study used naturalistic observations to provide descriptive information about low-income children's emotional and social competence in school settings. The specific goals…

  4. 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.

  5. 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.

  6. Nutrient Intake and Anemia Risk in the WHI Observational Study

    PubMed Central

    Stanaway, Jeffrey; Neuhouser, Marian L.; Snetselaar, Linda G.; Stefanick, Marcia L.; Arendell, Leslie; Chen, Zhao

    2011-01-01

    Background Nutritional anemia among post-menopausal women is preventable; recent data on prevalence are limited. Objective To investigate the association between nutrient intakes and anemia prevalence, in relation to both incidence and persistence, in a longitudinal sample of post-menopausal women. We hypothesized that anemia prevalence, incidence and persistence would be greater among women reporting lower intake of B12, folate and iron. Design Prospective cohort analysis. Participants/setting Observational Cohort of the Women’s Health Initiative(WHI-OS) including 93,676 postmenopausal women, age 50 to 79 years, were recruited across the United States at 40 clinical study sites. Women were enrolled between 1993 and 1998; data collection for these analyses continued through 2000. Main outcome measures Anemia was defined as a blood hemoglobin concentration of <12.0 mg/dL. Persistent anemia was defined as anemia present at each measurement time point. Diet was assessed by food frequency questionnaire for iron, folate, B12, red meat and cold breakfast cereal; inadequacies were based on dietary reference intakes for women over age 50 years. Statistical analysis Descriptive statistics (mean and standard deviation) were used to characterize the population demographics, anemia rates and diet. Unconditional logistic regression was used to investigate associations between diet and incident and persistent anemia. Associations are presented as odds ratio (OR) and 95% confidence intervals (CI). Results Anemia was identified in 3,979 women or 5.5% of the cohort. Inadequate intakes of multiple anemia-associated nutrients were less frequent in non-Hispanic whites (7.4%) than other race/ethnic groups (inadequacies demonstrated in 14.6 to 16.3% of sample). Age, body mass index and smoking were associated with anemia. Women with anemia reported lower intakes of energy, protein, folate, B12, iron, vitamin C and red meat. Multiple (more than a single nutrient) dietary deficiencies were associated with a 21% greater risk of persistent anemia (OR-1.21, 95% CI: 1.05–1.41) and three deficiencies resulted in a 44% increase in risk for persistent anemia (OR-1.44, 95% CI: 1.20–1.73). Conclusion Inadequate nutrient intake, a modifiable condition, is associated with greater risk for anemia in post-menopausal women participating in the WHI-OS. Efforts to identify and update incidence estimates for anemia-associated nutrient deficiencies in aging women should be undertaken. PMID:21443985

  7. Lifetime socioeconomic position and mortality: prospective observational study.

    PubMed Central

    Smith, G. D.; Hart, C.; Blane, D.; Gillis, C.; Hawthorne, V.

    1997-01-01

    OBJECTIVES: To assess the influence of socioeconomic position over a lifetime on risk factors for cardiovascular disease, on morbidity, and on mortality from various causes. DESIGN: Prospective observational study with 21 years of follow up. Social class was determined as manual or non-manual at three stages of participants' lives: from the social class of their father's job, the social class of their first job, and the social class of their job at the time of screening. A cumulative social class indicator was constructed, ranging from non-manual social class at all three stages of life to manual social class at all three stages. SETTING: 27 workplaces in the west of Scotland. PARTICIPANTS: 5766 men aged 35-64 at the time of examination. MAIN OUTCOME MEASURES: Prevalence and level of risk factors for cardiovascular disease; morbidity; and mortality from broad causes of death. RESULTS: From non-manual social class locations at all three life stages to manual at all stages there were strong positive trends for blood pressure, body mass index, current cigarette smoking, angina, and bronchitis. Inverse trends were seen for height, cholesterol concentration, lung function, and being an ex-smoker. 1580 men died during follow up. Age adjusted relative death rates in comparison with the men of non-manual social class locations at all three stages of life were 1.29 (95% confidence interval 1.08 to 1.56) in men of two non-manual and one manual social class; 1.45 (1.21 to 1.73) in men of two manual and one non-manual social class; and 1.71 (1.46 to 2.01) in men of manual social class at all three stages. Mortality from cardiovascular disease showed a similar graded association with cumulative social class. Mortality from cancer was mainly raised among men of manual social class at all three stages. Adjustment for a wide range of risk factors caused little attenuation in the association of cumulative social class with mortality from all causes and from cardiovascular disease; greater attenuation was seen in the association with mortality from non-cardiovascular, non-cancer disease. Fathers having a manual [corrected] occupation was strongly associated with mortality from cardiovascular disease: relative rate 1.41 (1.15 to 1.72). Participants' social class at the time of screening was more strongly associated than the other social class indicators with mortality from cancer and from non-cardiovascular, non-cancer causes. CONCLUSIONS: Socioeconomic factors acting over the lifetime affect health and risk of premature death. The relative importance of influences at different stages varies for the cause of death. Studies with data on socioeconomic circumstances at only one stage of life are inadequate for fully elucidating the contribution of socioeconomic factors to health and mortality risk. PMID:9055712

  8. DIAGNOSTIC EVALUATION OF AIR QUALITY MODELS USING ADVANCED METHODS WITH SPECIALIZED OBSERVATIONS OF SELECTED AMBIENT SPECIES -PART II

    EPA Science Inventory

    This is Part 2 of "Diagnostic Evaluation of Air Quality Models Using Advanced Methods with Specialized Observations of Selected Ambient Species". A limited field campaign to make specialized observations of selected ambient species using advanced and innovative instrumentation f...

  9. Observations of the magnetospheric boundary layers. [International Magnetospheric Study

    NASA Technical Reports Server (NTRS)

    Eastman, T. E.

    1984-01-01

    Results on magnetospheric boundary layers are reviewed, emphasizing their dynamical importance based on hot plasma observations, energetic particle signatures, heavy ion contributions and the effects of wave-particle interactions. Satellite plasma observations show that 1% to 2% of the oncoming solar wind plasma enters the magnetosphere and is initially transported within the magnetospheric boundary layer. Some of this boundary layer plasma is entrained within the Earth's magnetotail where it can be accelerated. Tests are needed to determine the relative contributions of the primary acceleration processes whose effects are especially evident in the plasma sheet boundary layer.

  10. Large-Scale periodic solar velocities: An observational study

    NASA Technical Reports Server (NTRS)

    Dittmer, P. H.

    1977-01-01

    Observations of large-scale solar velocities were made using the mean field telescope and Babcock magnetograph of the Stanford Solar Observatory. Observations were made in the magnetically insensitive ion line at 5124 A, with light from the center (limb) of the disk right (left) circularly polarized, so that the magnetograph measures the difference in wavelength between center and limb. Computer calculations are made of the wavelength difference produced by global pulsations for spherical harmonics up to second order and of the signal produced by displacing the solar image relative to polarizing optics or diffraction grating.

  11. 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.

  12. A Method for Observing Soil Re-Deposition and Soil Loss Rates in Large Field Experiments

    NASA Astrophysics Data System (ADS)

    Hsieh, Y. P.; Bugna, G. C.; Nemours, D.

    2014-12-01

    The lack of quality soil erosion field data, which is required for the verification and calibration of soil erosion models, has been one of the serious problems in the soil conservation modeling today. Observing soil erosion of a relatively large field under truly unobstructed runoff conditions has rarely been done and doccumented. Report here is the results of our observation of soil erosion in a 7.3 ha peanut-cotton cropping system in the Mears Farm of Grand Ridge, FL. We used the mesh-pad method to quantify soil loss from the field and soil re-deposition in the field over the cropping season of 2010. The main slope (1-3 %) of the field is about 210 m long. We show that the amount of soil re-deposition was 50-150 times of the soil loss from the slope. The corresponding organic matter, nitrogen, phosphorous and silt and clay contents of the lost soil, however, were 20.9%, 21%, 17.6% and 14.2%, respectively, of the total amounts re-deposited on the slope. The amounts of soil loss predicted by a SWAT model was 10-20 times greater than our observed values. Soil erosion process was quite heterogeneous, as shown by the mesh-pad method, even on a seemingly uniform cultivated field. Soil erosion models need to be verified and calibrated by extensive quality field data in order to improve their performance.

  13. A comparison of reconstruction methods for the estimation of coronal mass ejections kinematics based on SECCHI/HI observations

    SciTech Connect

    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.

  14. Influence of goals on observation of actions: functional neuroimaging studies

    E-print Network

    of the superior temporal sulcus area, or pSTS) increased parametrically with the presence of a goal The posterior part of the superior temporal sulcus 28 Other regions 28 Chapter 2. Cognitive processes in ToM 30 Biological motion and the superior temporal sulcus 53 Attention effects 58 3.2.1 Action observation

  15. 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.

  16. 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.

  17. 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

  18. Observational and theoretical studies of the nova outburst

    SciTech Connect

    Starrfield, S.; Vanlandingham, K.; Schwarz, G.

    1998-04-01

    A nova outburst is one consequence of the accretion of hydrogen rich material onto a white dwarf in a close binary system. The strong electron degeneracy of a massive white dwarf drives the temperatures in the nuclear burning region to values exceeding 108K under all circumstances. As a result, a major fraction of the CNO nuclei in the envelope are transformed into e{sup +}-decay nuclei, which constrains the nuclear energy generation and yields non-solar CNO isotopic abundance ratios. In addition, the observations demonstrate that white dwarf core material is dredged up into the accreted layers and these nuclei are the catalysts for producing peak rates of energy generation that can exceed 10{sup 16} erg gm{sup -1}s{sup -1}. Observations show that there are two compositional classes of novae, one that occurs on a carbon-oxygen white dwarf and the other that occurs on an oxygen-neon-magnesium white dwarf.

  19. 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.

  20. Observations on ion track structure in semiconductors : a phenomenological study

    NASA Technical Reports Server (NTRS)

    Selva, L. E.; Wallace, R. E.

    2001-01-01

    An ion track structure model at the nanometer scale is presented. The model is based on electrostatic principles and is supported by observed experimental results conducted on power MOSFETs. The model predicts the existence of a transient induced electric field following the passage of an energetic heavy ion. There are two segments to the field (a radial and an axial component). It is the interaction of this transient electric field with the local environment that can trigger a catastrophic failure.

  1. Observational Studies of the Formation and Evolution of Dense Cores

    NASA Astrophysics Data System (ADS)

    Tafalla, Mario

    2015-08-01

    Dense cores are the simplest star-forming sites. They represent the end point of the fragmentation hierarchy that characterizes molecular clouds, and they likely control the efficiency of star formation via their relatively low numbers. Recent continuum observations of entire molecular clouds show that dense cores often lie along large-scale filamentary structures, suggesting that the cores form by some type of fragmentation process in a close-to-cylindrical geometry. To understand the exact formation mechanism of cores, additional kinematic information is needed, and this requires observations made using molecular-line tracers of both the dense cores and their surrounding cloud material. In this talk, I will present some of the most recent efforts to clarify the kinematic structure of core-forming regions, like those in the nearby Taurus molecular cloud. These observations show that the filamentary structures seen in clouds are often more complex than suggested by the maps of continuum emission, and that consist of multiple fiber-like components having different velocities and sonic internal motions. These components likely arise from turbulent fragmentation of the large scale flows that generate the filamentary structures. While not all these fiber-like components further fragment to form dense cores, a small group does so, likely by gravitational instability, and produces characteristic chain-like groups of dense cores that further evolve toward star formation.

  2. 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 ...

  3. 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.

  4. 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…

  5. A comparative study between a high-gain interconnected observer and an adaptive observer applied to IM-based WECS

    NASA Astrophysics Data System (ADS)

    Naifar, Omar; Boukettaya, Ghada; Oualha, Abdelmajid; Ouali, Abderrazak

    2015-05-01

    This paper is devoted to the investigation of the potentialities of induction motor sensorless strategies in speed control applications. A comparison study is carried out between two observation approaches dedicated to speed control strategies of induction machine (IM)-based wind energy conversion systems (WECS) under parametric variations, such as: i) the adaptive observer approach, which is based on the speed adaptation law and ii) the interconnected observer, that offers robustness and stability of the system with reduced CPU time. The comparison study is achieved considering four performance criteria: stability, robustness with respect to the variations of the machine inductances, robustness with respect to the variations of the machine resistances, feasibility of the torque estimation. It has been found that the introduced interconnected observer exhibits a higher performance than the traditional adaptive one, with respect to the above-cited comparison criteria.

  6. 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...

  7. Using action observation to study superior motor performance: a pilot fMRI study

    PubMed Central

    Olsson, Carl-Johan; Lundström, Peter

    2013-01-01

    The most efficient way to acquire motor skills may be through physical practice. Nevertheless, it has also been shown that action observation may improve motor performance. The aim of the present pilot study was to examine a potential action observation paradigm used to (1) capture the superior performance of expert athletes and (2) capture the underlying neural mechanisms of successful action observation in relation to task experience. We used functional magnetic resonance imaging to measure regional blood flow while presenting videos of a hockey player shooting a puck toward a hockey goal. The videos (a total of 120) where stopped at different time frames with different amount of information provided, creating a paradigm with three different levels of difficulty to decide the fate of a shot. Since this was only a pilot study, we first tested the paradigm behaviorally on six elite expert hockey players, five intermediate players, and six non-hockey playing controls. The results showed that expert hockey players were significantly (p < 0.05) more accurate on deciding the fate of the action compared to the others. Thus, it appears as if the paradigm can capture superior performance of expert athletes (aim 1). We then tested three of the hockey players and three of the controls on the same paradigm in the MRI scanner to investigate the underlying neural mechanisms of successful action anticipation. The imaging results showed that when expert hockey players observed and correctly anticipated situations, they recruited motor and temporal regions of the brain. Novices, on the other hand, relied on visual regions during observation and prefrontal regions during action decision. Thus, the results from the imaging data suggest that different networks of the brain are recruited depending on task experience (aim 2). In conclusion, depending on the level of motor skill of the observer, when correctly anticipating actions different neural systems will be recruited. PMID:24348365

  8. 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

  9. 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.

  10. An Observational Study of Group Waterpipe Use in a Natural Environment

    PubMed Central

    2014-01-01

    Introduction: To date research on tobacco smoking with a waterpipe (hookah, narghile, and shisha) has focused primarily on the individual user in a laboratory setting. Yet, waterpipe tobacco smoking is often a social practice that occurs in cafés, homes, and other natural settings. This observational study examined the behavior of waterpipe tobacco smokers and the social and contextual features of waterpipe use among groups in their natural environment. Methods: Trained observers visited urban waterpipe cafés on multiple occasions during an 8-month period. Observations of 241 individual users in naturally formed groups were made on smoking topography (puff frequency, duration, and interpuff interval [IPI]) and engagement in other activities (e.g., food and drink consumption, other tobacco use, and media viewing). Results: Most users were male in group sizes of 3–4 persons, on average, and each table had 1 waterpipe, on average. The predominant social features during observational periods were conversation and nonalcoholic drinking. Greater puff number was associated with smaller group sizes and more waterpipes per group, while longer IPIs were associated with larger group sizes and fewer waterpipes per group. Additionally, greater puff frequency was observed during media viewing and in the absence of other tobacco use. Conclusions: Overall, the results suggest that waterpipe smoking behavior is affected by group size and by certain social activities. Discussion focuses on how these findings enhance our understanding of factors that may influence exposure to waterpipe tobacco smoke toxicants in naturalistic environments. PMID:23943842

  11. 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.

  12. Studying Distance Students: Methods, Findings, Actions

    ERIC Educational Resources Information Center

    Wahl, Diane; Avery, Beth; Henry, Lisa

    2013-01-01

    University of North Texas (UNT) Libraries began studying the library needs of distance learners in 2009 using a variety of approaches to explore and confirm these needs as well as obtain input into how to meet them. Approaches used to date include analysis of both quantitative and qualitative responses by online students to the LibQUAL+[R] surveys…

  13. 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

  14. In operandi observation of dynamic annealing: A case study of boron in germanium nanowire devices

    SciTech Connect

    Kole?nik-Gray, Maria M.; Krsti?, Vojislav; Sorger, Christian; Weber, Heiko B.; Biswas, Subhajit; Holmes, Justin D.

    2015-06-08

    We report on the implantation of boron in individual, electrically contacted germanium nanowires with varying diameter and present a technique that monitors the electrical properties of a single device during implantation of ions. This method gives improved access to study the dynamic annealing ability of the nanowire at room temperature promoted by its quasi-one-dimensional confinement. Based on electrical data, we find that the dopant activation efficiency is nontrivially diameter dependent. As the diameter decreases, a transition from a pronounced dynamic-annealing to a radiation-damage dominated regime is observed.

  15. Periodontal Disease and Risk of Head and Neck Cancer: A Meta-Analysis of Observational Studies

    PubMed Central

    Zeng, Xian-Tao; Deng, Ai-Ping; Li, Cheng; Xia, Ling-Yun; Niu, Yu-Ming; Leng, Wei-Dong

    2013-01-01

    Background Many epidemiological studies have found a positive association of periodontal disease (PD) with risk of head and neck cancer (HNC), but the findings are varied or even contradictory. In this work, we performed a meta-analysis to ascertain the relationship between PD and HNC risk. Methods We searched the PubMed, Embase, and Cochrane Library databases for relevant observational studies on the association between PD and HNC risk published up to March 23, 2013. Data from the included studies were extracted and analyzed independently by two authors. Meta-analysis was performed using RevMan 5.2 software. Results We obtained seven observational studies involving two cohort and six case-control studies. Random-effects meta-analysis indicated a significant association between PD and HNC risk (odds ratio = 2.63, 95% confidence interval = 1.1.68 - 4.14; p < 0.001), with sensitivity analysis showing that the result was robust. Subgroup analyses based on adjustment for covariates, study design, PD assessment, tumor site, and ethnicity also revealed a significant association. Conclusions Based on currently evidence, PD is probably a significant and independent risk factor of HNC. PMID:24194957

  16. 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

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

    NASA Astrophysics Data System (ADS)

    Sivron, Ran

    1995-03-01

    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.

  18. 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.

  19. Study of Ultrasonic Machining by Longitudinal-torsional Vibration for Processing Brittle Materials-observation of Machining Marks

    NASA Astrophysics Data System (ADS)

    Asami, Takuya; Miura, Hikaru

    The ultrasonic machining is a processing method using both the ultrasonic vibration of the tool horn and abrasive slurry. We studied a new ultrasonic machining method using ultrasonic complex vibration caused by the longitudinal and torsional vibration. In previous studies, we found that the machining speed and the machining accuracy when using a complex vibration are improved as compared with that using conventional ultrasonic machining method. However, the mechanism of ultrasonic machining using longitudinal-torsional vibration has not been clarified. In this presentation, we study that the observation of machining marks of soda-lime glass caused by ultrasonic machining using complex vibration.

  20. Presentation of continuous outcomes in randomised trials: an observational study

    PubMed Central

    2012-01-01

    Objective To characterise the percentage of available outcome data being presented in reports of randomised clinical trials with continuous outcome measures, thereby determining the potential for incomplete reporting bias. Design Descriptive cross sectional study. Data sources A random sample of 200 randomised trials from issues of 20 medical journals in a variety of specialties during 2007–09. Main outcome measures For each paper’s best reported primary outcome, we calculated the fraction of data reported using explicit scoring rules. For example, a two arm trial with 100 patients per limb that reported 2 sample sizes, 2 means, and 2 standard deviations reported 6/200 data elements (1.5%), but if that paper included a scatterplot with 200 points it would score 200/200 (100%). We also assessed compliance with 2001 CONSORT items about the reporting of results. Results The median percentage of data reported for the best reported continuous outcome was 9% (interquartile range 3–26%) but only 3.5% (3–7%) when we adjusted studies to 100 patients per arm to control for varying study size; 17% of articles showed 100% of the data. Tables were the predominant means of presenting the most data (59% of articles), but papers that used figures reported a higher proportion of data. There was substantial heterogeneity among journals with respect to our primary outcome and CONSORT compliance. Limitations We studied continuous outcomes of randomised trials in higher impact journals. Results may not apply to categorical outcomes, other study designs, or other journals. Conclusions Trialists present only a small fraction of available data. This paucity of data may increase the potential for incomplete reporting bias, a failure to present all relevant information about a study’s findings. PMID:23249670

  1. Comparison of self-report, video observation and direct measurement methods for upper extremity musculoskeletal disorder physical risk factors.

    PubMed

    Spielholz, P; Silverstein, B; Morgan, M; Checkoway, H; Kaufman, J

    2001-05-15

    The prevention of work-related musculoskeletal disorders has become a national priority in many countries. Increasingly, attempts are made to quantify those exposures that increase risk in order to set exposure limit values. This study used commonly employed field measurement methods and tools in order to perform an inter-method comparison between three primary methods of risk factor exposure assessment: self-report questionnaires, observational video analysis and direct measurement. Extreme posture duration, repetition, hand force (estimated from electromyography) and movement velocity were assessed for 18 subjects while performing each of three jobs processing tree seedlings. Results indicated that self-reports were the least precise assessment method, which consistently overestimated exposures for each of the measured risk factors. However, adjustment of the reports as psychophysical scales may increase agreement on a group level. Wrist flexion/extension duration and repetition were best measured by electrogoniometer. Electrogoniometric measures of wrist deviation duration and frequency were less precise than video analysis. Forearm rotation duration and repetition, grip force and velocity appeared to be best quantified by direct measurement as measured by electrogoniometer and electromyography (EMG) (as root-mean-square amplitude). The results highlight the fact that it is as important to consider and report estimated measurement error in order to reduce potential exposure misclassification in epidemiologic studies. PMID:11373023

  2. Point observations of liquid water content in natural snow - investigating methodical, spatial and temporal aspects

    NASA Astrophysics Data System (ADS)

    Techel, F.; Pielmeier, C.

    2010-10-01

    Information on the amount and distribution of liquid water in the snowpack is important for forecasting wet snow avalanches and predicting melt-water run-off. Considerable spatial and temporal variations of snowpack wetness exist. Currently, available information relies mostly on point observations. Often, the snow wetness is estimated manually using a hand test. However, quantitative measures are also applied. We compare the hand test to quantitative measurements and investigate temporal and small-scale spatial aspects of the snowpack wetness. For this, the liquid water content was measured using dielectric methods, with the Snow Fork and Denoth wetness instrument in the Swiss Alps, mostly above tree-line. More than 12 000 water content measurements were observed on 30 days in 85 locations. The qualitative hand test provides an indication of snowpack wetness, although snowpack wetness is often over-estimated and quantitative water content measurements are more reliable. If the measured water content is very low, it is unclear if the snow is dry or contains small quantities of liquid water. In particular during the initial melt-phase, when the snowpack is only partially wet, it is important to consider spatial aspects when interpreting point observations. One measurement taken at a certain measurement depth may significantly deviate in 10-20% of the cases from snowpack wetness in the surrounding snow. Not surprisingly, diurnal changes in snowpack wetness are significant in layers close to the snow surface. At depth, changes were noted within the course of a day. From a single vertical profile, it was often unclear if these changes were due to the heterogeneous nature of water infiltration. Based on our observations, we propose to repeat three measurements at horizontal distances greater than 50 cm. This approach provides representative snow wetness information for horizontal distances up to 5 m. Further, we suggest a simplified classification scheme of snowpack wetness by introducing five wetness types of the snowpack incorporating both vertical and horizontal liquid water content distribution.

  3. Region of interest based Hotelling observer for computed tomography with comparison to alternative methods

    PubMed Central

    Sanchez, Adrian A.; Sidky, Emil Y.; Pan, Xiaochuan

    2014-01-01

    Abstract. We compare several approaches to estimation of Hotelling observer (HO) performance in x-ray computed tomography (CT). We consider the case where the signal of interest is small so that the reconstructed image can be restricted to a small region of interest (ROI) surrounding the signal. This reduces the dimensionality of the image covariance matrix so that direct computation of HO metrics within the ROI is feasible. We propose that this approach is directly applicable to systems optimization in CT; however, many alternative approaches exist, which make computation of HO performance tractable through a range of approximations, assumptions, or estimation strategies. Here, we compare several of these methods, including the use of Laguerre-Gauss channels, discrete Fourier domain computation of the HO (which assumes noise stationarity), and two approaches to HO estimation through samples of noisy images. Since our method computes HO performance exactly within an ROI, this allows us to investigate the validity of the assumptions inherent in various common approaches to HO estimation, such as the stationarity assumption in the case of the discrete Fourier transform domain method. PMID:25685825

  4. Observation of Joining Phenomena in Friction Stage and Improving Friction Welding Method

    NASA Astrophysics Data System (ADS)

    Kimura, Masaaki; Seo, Kenji; Kusaka, Masahiro; Fuji, Akiyoshi

    This report describes the observation result of joining phenomena in the friction stage, and an improvement of the conventional friction welding method with similar materials. The materials used were carbon steels and a brake type (direct drive) friction welding machine was used for joining. As the improving friction welding method, relative speed was instantaneously rendered to zero at the end of each friction time. The wear of both surfaces started at periphery portion (outer surface) of the joint and moved to center portion (center axis). Seizure and joining began at center portion and then extended toward periphery portion. The friction torque reached to initial peak torque when the welded interface was joined completely and upsetting of both base metals started. It was determined that friction welded joints with 100% joint efficiency and good bend ductility could be obtained by using only the friction stage up to initial peak torque and without the need for the forging (upsetting) stage. As a conclusion, friction welded joints made without using the forging stage has the same mechanical properties as those welded by the conventional friction welding process including that stage. The friction welding method without forging stage has the advantages of less burn-off (axial shortening) and less burr.

  5. In Vitro Cercariae Transformation: Comparison of Mechanical and Nonmechanical Methods and Observation of Morphological Changes of Detached Cercariae Tails

    PubMed Central

    Coultas, Kristen A.; Zhang, Si-Ming

    2013-01-01

    Schistosomula, the larval stage of schistosomes in vertebrate hosts, are highly vulnerable and considered an ideal target for vaccine and drug development. Although the schistosomule stage is essential for biological studies, collecting sufficient numbers of schistosomula from their definitive hosts in vivo is difficult to accomplish. However, in vitro collection via cercariae transformation can effectively yield high numbers of schistosomula. We compared a current and widely used double-ended–needle mechanical transformation method to a culture medium based on a nonmechanical method. We found the rates of transformed cercariae, i.e., separated cercariae heads from tails, differed by only 2–7% at 0.5, 1, and 2 days in culture and that there was no significant difference in the number of transformed cercariae between the transformation methods at 3 and 4 days in culture. Notably, the mechanical and nonmechanical cercariae transformation methods both yielded significantly large and similar quantities of viable schistosomula. Given that the nonmechanical method is simpler and less damaging to the parasites, we recommend the use of it as an alternative way for in vitro cercariae transformation. In addition, we also observed morphological changes of the detached cercariae tails in culture medium. Interestingly, the tails are able to regenerate head-like organs/tissues and survive for at least 4 days. This intriguing change suggests unique biological features of the cells in the tails. PMID:22519732

  6. Scalable Methods for Electronic Excitations and Optical Responses of Nanstructures: Mathematics to Algorithms to Observables

    SciTech Connect

    Emily A. Carter

    2009-01-23

    This multi-investigator project was concerned with the development and application of new methods and computer codes that would allow realistic modeling of nanosystems. Carter's part in this team effort involved two method/algorithm/code development projects during the first 14 months of this grant. Carter's group has been advancing theory and applications of the orbital-free density functional theory (OF-DFT), the only DFT method that exhibits linear scaling for metals. Such a method offers the possibility of simulating large numbers of atoms with quantum mechanics, such that properties of metallic nanostructures (e.g. nanowires of realistic dimensions) could be investigated. In addition, her group has been developing and applying an embedded correlated wavefunction theory for treating localized excited states in condensed matter (including metals). The application of interest here is spin manipulation at the nanoscale, i.e., spintronics, in which local electron excitations interact with the surrounding material. Her embedded correlation method is ideal for studying such problems.

  7. The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) Statement

    PubMed Central

    Benchimol, Eric I.; Smeeth, Liam; Guttmann, Astrid; Harron, Katie; Moher, David; Petersen, Irene; Sørensen, Henrik T.; von Elm, Erik; Langan, Sinéad M.

    2015-01-01

    Routinely collected health data, obtained for administrative and clinical purposes without specific a priori research goals, are increasingly used for research. The rapid evolution and availability of these data have revealed issues not addressed by existing reporting guidelines, such as Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). The REporting of studies Conducted using Observational Routinely collected health Data (RECORD) statement was created to fill these gaps. RECORD was created as an extension to the STROBE statement to address reporting items specific to observational studies using routinely collected health data. RECORD consists of a checklist of 13 items related to the title, abstract, introduction, methods, results, and discussion section of articles, and other information required for inclusion in such research reports. This document contains the checklist and explanatory and elaboration information to enhance the use of the checklist. Examples of good reporting for each RECORD checklist item are also included herein. This document, as well as the accompanying website and message board (http://www.record-statement.org), will enhance the implementation and understanding of RECORD. Through implementation of RECORD, authors, journals editors, and peer reviewers can encourage transparency of research reporting. PMID:26440803

  8. 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.

  9. The low-temperature method for study of coniferous tissues in the environmental scanning electron microscope.

    PubMed

    Ned?la, Vilém; Tihla?íková, Eva; H?ib, Ji?í

    2015-01-01

    The use of non-standard low-temperature conditions in environmental scanning electron microscopy might be promising for the observation of coniferous tissues in their native state. This study is aimed to analyse and evaluate the method based on the principle of low-temperature sample stabilization. We demonstrate that the upper mucous layer is sublimed and a microstructure of the sample surface can be observed with higher resolution at lower gas pressure conditions, thanks to a low-temperature method. An influence of the low-temperature method on sample stability was also studied. The results indicate that high-moisture conditions are not suitable for this method and often cause the collapse of samples. The potential improvement of stability to beam damage has been demonstrated by long-time observation at different operation parameters. We finally show high applicability of the low-temperature method on different types of conifers and Oxalis acetosella. PMID:25242151

  10. Narrative Inquiry as Travel Study Method: Affordances and Constraints

    ERIC Educational Resources Information Center

    Craig, Cheryl J.; Zou, Yali; Poimbeauf, Rita

    2014-01-01

    This article maps how narrative inquiry--the use of story to study human experience--has been employed as both method and form to capture cross-cultural learning associated with Western doctoral students' travel study to eastern destinations. While others were the first to employ this method in the travel study domain, we are the first to…

  11. 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...

  12. 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.

  13. Experimental and Observational Data in the Study of Interlanguage Pragmatics.

    ERIC Educational Resources Information Center

    Hartford, Beverly S.; Bardovi-Harlig, Kathleen

    1992-01-01

    A study compared (1) data on rejections of advice by native and non-native speakers collected from natural conversation with (2) data collected from a discourse completion task (DCT). Subjects were students in an academic advising session (13 native speakers, 11 non-native speakers of English) who responded to a DCT and students (18 native…

  14. 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…

  15. 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…

  16. Musical Expression: An Observational Study of Instrumental Teaching

    ERIC Educational Resources Information Center

    Karlsson, Jessika; Juslin, Patrik N.

    2008-01-01

    Research has shown that both music students and teachers think that expression is important. Yet, we know little about how expression is taught to students. Such knowledge is needed in order to enhance teaching of expression. The aim of this study was thus to explore the nature of instrumental music teaching in its natural context, with a focus on…

  17. Observational descriptive study of cutaneous manifestations in patients from Mato Grosso with viral chronic hepatitis*

    PubMed Central

    Rostey, Renato Roberto Liberato; Souto, Francisco José Dutra

    2015-01-01

    BACKGROUND Extrahepatic manifestations are seen in association with chronic infection by hepatitis B or C virus including cutaneous disorders. The frequency of these findings seems to vary among different places and reports. There is a lack of information about this issue in Brazil. OBJECTIVES To estimate the prevalence of cutaneous findings affecting HBV or HCV carriers from a reference outpatient unit in Mato Grosso. METHODS A cross-sectional observational study. RESULTS 108 patients were studied. 88.9% presented some cutaneous findings but must of them were nonrelated to chronic viral infection. Four patients had cutaneous or autoimmune syndromes that may be HBV or HCV related. CONCLUSION In our study we found no statistical association between viral hepatitis and skin diseases.

  18. Empathy levels among first year Malaysian medical students: an observational study

    PubMed Central

    Williams, Brett; Sadasivan, Sivalal; Kadirvelu, Amudha; Olaussen, Alexander

    2014-01-01

    Background The literature indicates that medical practitioners experience declining empathy levels in clinical practice. This highlights the need to educate medical students about empathy as an attribute early in the academic curriculum. The objective of this study was to evaluate year one students’ self-reported empathy levels following a 2-hour empathy workshop at a large medical school in Malaysia. Methods Changes in empathy scores were examined using a paired repeated-measures t-test in this prospective before and after study. Results Analyzing the matched data, there was a statistically significant difference and moderate effect size between mean empathy scores before and 5 weeks after the workshop (112.08±10.67 versus 117.93±13.13, P<0.0001, d=0.48) using the Jefferson Scale Physician Empathy (Student Version). Conclusion The results of this observational study indicate improved mean self-reported empathy scores following an empathy workshop. PMID:24876799

  19. Survey and Chase: A New Method of Observations For The Michigan Orbital Debris Survey Telescope (MODEST)

    NASA Technical Reports Server (NTRS)

    Abercromby, Kira J.; Seitzer, Patrick; Rodriquez, Heather M.; Barker, Edwin S.; Matney, Mark J.

    2006-01-01

    For more than 40 years astronauts have been observing Earth, taking photographs or digital images from their spacecraft. Today, a robust program of observation from the International Space Station (ISS) has yielded hundreds of thousands of images of the Earth s surface collected since 2001. Seeing Earth through the eyes of an astronaut is exciting to the general public, and the images are popular in classrooms. Because the ISS has an orbital inclination of 51.6 degrees (the north-south limits of the orbit are at 51.6 degrees latitude), high latitude observations are common. Some of the most striking images collected include views of polar phenomena. Astronauts routinely pass above brilliant red and green aurora; view high, wispy clouds at the top of the atmosphere; or look down on glaciers and floating ice rafts. These images, framed and captured by humans, are easily interpreted by students and teachers. Astronaut observations provide a way to visualize complicated polar phenomena and communicate about them to students of all ages. Over the next two years, astronauts aboard the ISS will formally focus their observations on polar phenomena as participants in the International Polar Year (IPY). Imagery acquisition from the ISS will be coordinated with other IPY scientists staging studies and field campaigns on the ground. The imagery collected from the ISS will be cataloged and served on NASA s web-based database of images, http://eol.jsc.nasa.gov . The website allows investigators, students and teachers to search through the imagery, assemble image datasets, and download the imagery and the metadata. We display some of the most spectacular examples of polar imagery and demonstrate NASA s database of astronaut images of Earth.

  20. The ALFA (Activity Log Files Aggregation) Toolkit: A Method for Precise Observation of the Consultation

    PubMed Central

    2008-01-01

    Background There is a lack of tools to evaluate and compare Electronic patient record (EPR) systems to inform a rational choice or development agenda. Objective To develop a tool kit to measure the impact of different EPR system features on the consultation. Methods We first developed a specification to overcome the limitations of existing methods. We divided this into work packages: (1) developing a method to display multichannel video of the consultation; (2) code and measure activities, including computer use and verbal interactions; (3) automate the capture of nonverbal interactions; (4) aggregate multiple observations into a single navigable output; and (5) produce an output interpretable by software developers. We piloted this method by filming live consultations (n = 22) by 4 general practitioners (GPs) using different EPR systems. We compared the time taken and variations during coded data entry, prescribing, and blood pressure (BP) recording. We used nonparametric tests to make statistical comparisons. We contrasted methods of BP recording using Unified Modeling Language (UML) sequence diagrams. Results We found that 4 channels of video were optimal. We identified an existing application for manual coding of video output. We developed in-house tools for capturing use of keyboard and mouse and to time stamp speech. The transcript is then typed within this time stamp. Although we managed to capture body language using pattern recognition software, we were unable to use this data quantitatively. We loaded these observational outputs into our aggregation tool, which allows simultaneous navigation and viewing of multiple files. This also creates a single exportable file in XML format, which we used to develop UML sequence diagrams. In our pilot, the GP using the EMIS LV (Egton Medical Information Systems Limited, Leeds, UK) system took the longest time to code data (mean 11.5 s, 95% CI 8.7-14.2). Nonparametric comparison of EMIS LV with the other systems showed a significant difference, with EMIS PCS (Egton Medical Information Systems Limited, Leeds, UK) (P = .007), iSoft Synergy (iSOFT, Banbury, UK) (P = .014), and INPS Vision (INPS, London, UK) (P = .006) facilitating faster coding. In contrast, prescribing was fastest with EMIS LV (mean 23.7 s, 95% CI 20.5-26.8), but nonparametric comparison showed no statistically significant difference. UML sequence diagrams showed that the simplest BP recording interface was not the easiest to use, as users spent longer navigating or looking up previous blood pressures separately. Complex interfaces with free-text boxes left clinicians unsure of what to add. Conclusions The ALFA method allows the precise observation of the clinical consultation. It enables rigorous comparison of core elements of EPR systems. Pilot data suggests its capacity to demonstrate differences between systems. Its outputs could provide the evidence base for making more objective choices between systems. PMID:18812313

  1. 10 years observation and rehabilitation of stroke disability. Longitudinal study.

    PubMed

    Wisniewska-Roszkowska, K; Jedynecki, A; Ziolkowski, W

    1975-01-01

    In the I State Home for Incurables in Lodz (Poland) 195 hemiplegia cases were observed over ten years. 140 women and 55 men. This comprised 8.2% and 17.8% of all ill females and males respectively. Causes of the lesion were vascular 187, trauma 4, neoplasm 4. Hemiparesis was in females most frequent between 60 and 80 years, in males between 50 and 80 years. Communication was absent or difficult in 126 cases (in 22 the cause was aphasia, in 104 dementia). Incontinence was noted in 77 cases, inability to walk (on admission) in 129. During the ten years under survey 135 died, 15 were discharged home, 26 females and 18 males were rehabilitated. Very good improvement in motor activity was obtained in 14 females (3 without kinesitherapy) and 7 males, indicating adequate walking and independence in activities of daily living after prolonged bedfastness. (average 2.5 years in males and 2.7 years in females). Altogether 88 patients improved from the locomotor angle. In cases with dementia, incontinence and severe aphasia prognosis in rehabilitation was found to be poor. PMID:1183816

  2. Gender differences in young children’s temperament traits: Comparisons across observational and parent-report methods

    PubMed Central

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

    2012-01-01

    Objective 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. Methods Across three independent samples, behavioral observations, maternal-report, and paternal-report measures of temperament were collected on 463 boys and 402 girls. Results 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. Conclusions Results are discussed in relation to past meta-analytic work and developmental implications of the findings. PMID:22924826

  3. 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.

  4. A systematic review of observational studies on oxidative/nitrosative stress involvement in dengue pathogenesis

    PubMed Central

    Pinzón, Hernando Samuel; Alvis-Guzman, Nelson

    2015-01-01

    Objective: Our objective was to systematically review the published observational research related to the role of oxidative-nitrosative stress in pathogenesis of dengue. Methods: We searched electronic databases (PubMed, EMBASE, The COCHRANE library, ScienceDirect, Scopus, SciELO, LILACS via Virtual Health Library, Google Scholar) using the term: dengue, dengue virus, severe dengue, oxidative stress, nitrosative stress, antioxidants, oxidants, free radicals, oxidized lipid products, lipid peroxides, nitric oxide, and nitric oxide synthase. Articles were selected for review by title and abstract excluding letter, review, in vivo and in vitro studies, and duplicates studies. Selected articles were reviewed for study design, original purposes, sample size, main outcomes, methods, and oxidative-nitrosative stress markers values. Results: In total, 4,331 non-duplicates articles were identified from electronic databases searches, of which 16 were eligible for full text searching. Data from the observational studies originate from Asian countries (50%; 8/16), South American countries (31.2%; 5/16), and Central America and the Caribbean countries (18.8%; 3/16). Case-control study was the type of design most common in researches reviewed. The 1997 World Health Organization (WHO) dengue case classification criteria were used in all studies included in this review. Conclusions: Based on published data found in peer-reviewed literature, oxidative and nitrosative stress are demonstrated by changes in plasma levels of nitric oxide, antioxidants, lipid peroxidation and protein oxidation markers in patients with dengue infection. Additionally, elevated serum protein carbonyls and malondialdehyde levels appear to be associated with dengue disease severity.

  5. 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.

  6. Observing power blackouts from space - A disaster related study

    NASA Astrophysics Data System (ADS)

    Aubrecht, C.; Elvidge, C. D.; Ziskin, D.; Baugh, K. E.; Tuttle, B.; Erwin, E.; Kerle, N.

    2009-04-01

    In case of emergency disaster managers worldwide require immediate information on affected areas and estimations of the number of affected people. Natural disasters such as earthquakes, hurricanes, tornados, wind and ice storms often involve failures in the electrical power generation system and grid. Near real time identification of power blackouts gives a first impression of the area affected by the event (Elvidge et al. 2007), which can subsequently be linked to population estimations. Power blackouts disrupt societal activities and compound the difficulties associated with search and rescue, clean up, and the provision of food and other supplies following a disastrous event. Locations and spatial extents of power blackouts are key considerations in planning and execution of the primary disaster missions of emergency management organizations. To date only one satellite data source has been used successfully for the detection of power blackouts. Operated by NOAA's National Geophysical Data Center (NGDC) the U.S. Air Force Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) offers a unique capability to observe lights present at the Earth's surface at night. Including a pair of visible and thermal spectral bands and originally designed to detect moonlit clouds, this sensor enables mapping of lights from cities and towns, gas flares and offshore platforms, fires, and heavily lit fishing boats. The low light imaging of the OLS is accomplished using a photomultiplier tube (PMT) which intensifies the visible band signal at night. With 14 orbits collected per day and a 3.000 km swath width, each OLS is capable of collecting a complete set of images of the Earth every 24 hours. NGDC runs the long-term archive for OLS data with the digital version extending back to 1992. OLS data is received by NGDC in near real time (1-2 hours from acquisition) and subscription based services for the near real time data are provided for users all over the world. Elvidge et al. (1998) first demonstrated that under certain conditions a detection of power outages is possible using OLS data. A standard procedure for visual detection of power outages has been developed. The procedure is based on identifying locations where consistently observed lighting is missing or reduced following a disaster event. Visible and thermal spectral bands of the event-related OLS data are compared to a recent cloud-free composite of nighttime lights by producing a color (RGB) composite image. For the cloud-free nighttime lights composite serving as reference information both monthly and annual composites can be used, depending on the respective availability and suitability of OLS data. The RGB color composite uses the reference lights as red (R), the current visible band as green (G) and the current thermal band as blue (B). The thermal band is typically inverted to make clouds appear bright. As clouds are typically colder than the surface of the Earth, in the thermal band higher values are observed on cloud-free areas, which thus appear brighter in standard visualization modes. The resulting color composite is visually interpreted to identify power outages, which show up as red lights on a dark (cloud-free) background. Red color stands for high values in the reference data (red band of the RGB composite) compared to low values in the event data (green and blue bands of the RGB composite), thus showing the disaster-related absence or reduction of lighting. Heavy cloud cover also obscures lights, resulting in red lights on a blue background. Yellow color in the RGB composite indicates areas where the lights are on, i.e. both red and green band (reference composite and visible band of the event image) feature high values with no cloud cover present (low values in the blue band). Under ideal conditions the presented procedure detects individual cities and towns where power has been lost or has been reduced. Conditions reducing or eliminating the capability of detecting power blackouts in OLS data have been identified (e.g. sunlight, heavy

  7. Functional Outcome Following Arthroscopic ACL Reconstruction with Rigid Fix: A Retrospective Observational Study

    PubMed Central

    Shervegar, Satish; Nagaraj, Prashanth; Grover, Amit; DJ, Niranthara Ganesh; Ravoof, Abdul

    2015-01-01

    Background: No uniform consensus exists to decide type of fixation for arthroscopic anterior cruciate ligament reconstruction. Hypothsis: There is similar functional outcome after rigid fix compared to other methods of fixation which has been published. Study design: Retrospective observational study. Methods: A total of 50 patients underwent arthroscopic anterior cruciate ligament reconstruction with hamstring tendons using femoral Rigid fix cross-pin and interference screw tibial fixation. The evaluation methods were clinical examination, IKDC scores, Lysholm and pre injury and post reconstruction Tegner score. Patients were followed up from minimum of 6 months to 4 year seven months. Results: C In our study of sample size 50 we found that mean age of patients was 30.8 Years with male preponderance. Mean post operative IKDC and Lysholm score has been 75.6 and 84.4 respectively. Mean Tegner pre-injury score and post reconstruction score has been 5.4 and 4.26. Box plot comparison of pre injury and post operativeTegner score reveals a statistically significant difference with respect to paired t test P<0.001. Conclusions: Arthroscopic anterior cruciate ligament reconstruction with femoral rigid fix cross pins and tibial interference screws results in comparable short term to midterm functional results compared to other types of fixation PMID:26550591

  8. Development of a Method for the Observation of Lightning in Protoplanetary Disks Using Ion Lines

    NASA Astrophysics Data System (ADS)

    Muranushi, Takayuki; Akiyama, Eiji; Inutsuka, Shu-ichiro; Nomura, Hideko; Okuzumi, Satoshi

    2015-12-01

    In this paper, we propose observational methods for detecting lightning in protoplanetary disks. We do so by calculating the critical electric field strength in the lightning matrix gas (LMG), the parts of the disk where the electric field is strong enough to cause lightning. That electric field accelerates multiple positive ion species to characteristic terminal velocities. In this paper, we present three distinct discharge models with corresponding critical electric fields. We simulate the position-velocity diagrams and the integrated emission maps for the models. We calculate the measure-of-sensitivity values for detection of the models and for distinguishing between the models. At the distance of TW Hya (54 pc), LMG that occupies 2? in azimuth and has 25 AU < r < 50 AU is detectable at 1200? to 4000?. The lower limits of the radii of 5?-detectable LMG clumps are between 1.6 AU and 5.3 AU, depending on the models.

  9. 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

  10. Computational methods for inverse problems in geophysics: inversion of travel time observations

    USGS Publications Warehouse

    Pereyra, V.; Keller, H.B.; Lee, W.H.K.

    1980-01-01

    General ways of solving various inverse problems are studied for given travel time observations between sources and receivers. These problems are separated into three components: (a) the representation of the unknown quantities appearing in the model; (b) the nonlinear least-squares problem; (c) the direct, two-point ray-tracing problem used to compute travel time once the model parameters are given. Novel software is described for (b) and (c), and some ideas given on (a). Numerical results obtained with artificial data and an implementation of the algorithm are also presented. ?? 1980.

  11. 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.

  12. Self-reported and observed seat belt use - A case study: Bosnia and Herzegovina.

    PubMed

    Lipovac, Krsto; Teši?, Milan; Mari?, Bojan; ?eri?, Miroslav

    2015-11-01

    The issue of seat belt use in middle- and low-income countries is strongly evident and has as a result higher rates of fatalities and seriously injured on the roads. The first systematic field research of the seat belt use while driving was carried out in Bosnia and Herzegovina, in 2011-2012. Research methodology consisted of two mutually conditioned parts (observation and self-reported behavior). Specific features of the methodology used are in the relationship between the observed and interviewed drivers which enabled the analysis of their observed and self-reported behavior while driving. The logistic regression method was used in this work to make the analysis of the influence of personal human characteristics (gender, age, education, exposure) and vehicles' characteristics (age) on the observed and self-reported driving behavior, from the point of view of seat belt use while driving. The influence of the listed factors on driving behavior, depending on road type (urban or rural), was given special attention in the analysis. The paper shows that certain factors do not have the same impact on driving behavior, in various conditions. Based on results from this study, it will be possible to define certain critical groups of road users and the way in which they must be addressed in order to increase the seat belt wearing rate. PMID:26320737

  13. 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

  14. UFOs in the LHC: Observations, studies and extrapolations

    E-print Network

    Baer, T; Cerutti, F; Ferrari, A; Garrel, N; Goddard, B; Holzer, EB; Jackson, S; Lechner, A; Mertens, V; Misiowiec, M; Nebot del Busto, E; Nordt, A; Uythoven, J; Vlachoudis, V; Wenninger, J; Zamantzas, C; Zimmermann, F; Fuster, N

    2012-01-01

    Unidentified falling objects (UFOs) are potentially a major luminosity limitation for nominal LHC operation. They are presumably micrometer sized dust particles which lead to fast beam losses when they interact with the beam. With large-scale increases and optimizations of the beam loss monitor (BLM) thresholds, their impact on LHC availability was mitigated from mid 2011 onwards. For higher beam energy and lower magnet quench limits, the problem is expected to be considerably worse, though. In 2011/12, the diagnostics for UFO events were significantly improved: dedicated experiments and measurements in the LHC and in the laboratory were made and complemented by FLUKA simulations and theoretical studies. The state of knowledge, extrapolations for nominal LHC operation and mitigation strategies are presented

  15. cAMP signaling microdomains and their observation by optical methods

    PubMed Central

    Calebiro, Davide; Maiellaro, Isabella

    2014-01-01

    The second messenger cyclic AMP (cAMP) is a major intracellular mediator of many hormones and neurotransmitters and regulates a myriad of cell functions, including synaptic plasticity in neurons. Whereas cAMP can freely diffuse in the cytosol, a growing body of evidence suggests the formation of cAMP gradients and microdomains near the sites of cAMP production, where cAMP signals remain apparently confined. The mechanisms responsible for the formation of such microdomains are subject of intensive investigation. The development of optical methods based on fluorescence resonance energy transfer (FRET), which allow a direct observation of cAMP signaling with high temporal and spatial resolution, is playing a fundamental role in elucidating the nature of such microdomains. Here, we will review the optical methods used for monitoring cAMP and protein kinase A (PKA) signaling in living cells, providing some examples of their application in neurons, and will discuss the major hypotheses on the formation of cAMP/PKA microdomains. PMID:25389388

  16. 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.

  17. Defining safe criteria to diagnose miscarriage: prospective observational multicentre study

    PubMed Central

    Preisler, Jessica; Kopeika, Julia; Ismail, Laure; Vathanan, Veluppillai; Farren, Jessica; Abdallah, Yazan; Battacharjee, Parijat; Van Holsbeke, Caroline; Bottomley, Cecilia; Gould, Deborah; Johnson, Susanne; Stalder, Catriona; Van Calster, Ben; Hamilton, Judith; Timmerman, Dirk

    2015-01-01

    Objectives To validate recent guidance changes by establishing the performance of cut-off values for embryo crown-rump length and mean gestational sac diameter to diagnose miscarriage with high levels of certainty. Secondary aims were to examine the influence of gestational age on interpretation of mean gestational sac diameter and crown-rump length values, determine the optimal intervals between scans and findings on repeat scans that definitively diagnose pregnancy failure.) Design Prospective multicentre observational trial. Setting Seven hospital based early pregnancy assessment units in the United Kingdom. Participants 2845 women with intrauterine pregnancies of unknown viability included if transvaginal ultrasonography showed an intrauterine pregnancy of uncertain viability. In three hospitals this was initially defined as an empty gestational sac <20 mm mean diameter with or without a visible yolk sac but no embryo, or an embryo with crown-rump length <6 mm with no heartbeat. Following amended guidance in December 2011 this definition changed to a gestational sac size <25 mm or embryo crown-rump length <7 mm. At one unit the definition was extended throughout to include a mean gestational sac diameter <30 mm or embryo crown-rump length <8 mm. Main outcome measures Mean gestational sac diameter, crown-rump length, and presence or absence of embryo heart activity at initial and repeat transvaginal ultrasonography around 7-14 days later. The final outcome was pregnancy viability at 11-14 weeks’ gestation. Results The following indicated a miscarriage at initial scan: mean gestational sac diameter ?25 mm with an empty sac (364/364 specificity: 100%, 95% confidence interval 99.0% to 100%), embryo with crown-rump length ?7 mm without visible embryo heart activity (110/110 specificity: 100%, 96.7% to 100%), mean gestational sac diameter ?18 mm for gestational sacs without an embryo presenting after 70 days’ gestation (907/907 specificity: 100%, 99.6% to 100%), embryo with crown-rump length ?3 mm without visible heart activity presenting after 70 days’ gestation (87/87 specificity: 100%, 95.8% to 100%). The following were indicative of miscarriage at a repeat scan: initial scan and repeat scan after seven days or more showing an embryo without visible heart activity (103/103 specificity: 100%, 96.5% to 100%), pregnancies without an embryo and mean gestational sac diameter <12 mm where the mean diameter has not doubled after 14 days or more (478/478 specificity: 100%, 99.2% to 100%), pregnancies without an embryo and mean gestational sac diameter ?12 mm showing no embryo heartbeat after seven days or more (150/150 specificity: 100%, 97.6% to 100%). Conclusions Recently changed cut-off values of gestational sac and embryo size defining miscarriage are appropriate and not too conservative but do not take into account gestational age. Guidance on timing between scans and expected findings on repeat scans are still too liberal. Protocols for miscarriage diagnosis should be reviewed to account for this evidence to avoid misdiagnosis and the risk of terminating viable pregnancies. PMID:26400869

  18. 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

  19. A New Method to Constrain Supernova Fractions Using X-ray Observations of Clusters of Galaxies

    NASA Technical Reports Server (NTRS)

    Bulbul, Esra; Smith, Randall K.; Loewenstein, Michael

    2012-01-01

    Supernova (SN) explosions enrich the intracluster medium (ICM) both by creating and dispersing metals. We introduce a method to measure the number of SNe and relative contribution of Type Ia supernovae (SNe Ia) and core-collapse supernovae (SNe cc) by directly fitting X-ray spectral observations. The method has been implemented as an XSPEC model called snapec. snapec utilizes a single-temperature thermal plasma code (apec) to model the spectral emission based on metal abundances calculated using the latest SN yields from SN Ia and SN cc explosion models. This approach provides a self-consistent single set of uncertainties on the total number of SN explosions and relative fraction of SN types in the ICM over the cluster lifetime by directly allowing these parameters to be determined by SN yields provided by simulations. We apply our approach to XMM-Newton European Photon Imaging Camera (EPIC), Reflection Grating Spectrometer (RGS), and 200 ks simulated Astro-H observations of a cooling flow cluster, A3112.We find that various sets of SN yields present in the literature produce an acceptable fit to the EPIC and RGS spectra of A3112. We infer that 30.3% plus or minus 5.4% to 37.1% plus or minus 7.1% of the total SN explosions are SNe Ia, and the total number of SN explosions required to create the observed metals is in the range of (1.06 plus or minus 0.34) x 10(exp 9), to (1.28 plus or minus 0.43) x 10(exp 9), fromsnapec fits to RGS spectra. These values may be compared to the enrichment expected based on well-established empirically measured SN rates per star formed. The proportions of SNe Ia and SNe cc inferred to have enriched the ICM in the inner 52 kiloparsecs of A3112 is consistent with these specific rates, if one applies a correction for the metals locked up in stars. At the same time, the inferred level of SN enrichment corresponds to a star-to-gas mass ratio that is several times greater than the 10% estimated globally for clusters in the A3112 mass range.

  20. 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

  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. Unintentional child neglect: literature review and observational study.

    PubMed

    Friedman, Emily; Billick, Stephen B

    2015-06-01

    Child abuse is a problem that affects over six million children in the United States each year. Child neglect accounts for 78% of those cases. Despite this, the issue of child neglect is still not well understood, partially because child neglect does not have a consistent, universally accepted definition. Some researchers consider child neglect and child abuse to be one in the same, while other researchers consider them to be conceptually different. Factors that make child neglect difficult to define include: (1) Cultural differences; motives must be taken into account because parents may believe they are acting in the child's best interests based on cultural beliefs (2) the fact that the effect of child abuse is not always immediately visible; the effects of emotional neglect specifically may not be apparent until later in the child's development, and (3) the large spectrum of actions that fall under the category of child abuse. Some of the risk factors for increased child neglect and maltreatment have been identified. These risk factors include socioeconomic status, education level, family composition, and the presence of dysfunction family characteristics. Studies have found that children from poorer families and children of less educated parents are more likely to sustain fatal unintentional injuries than children of wealthier, better educated parents. Studies have also found that children living with adults unrelated to them are at increased risk for unintentional injuries and maltreatment. Dysfunctional family characteristics may even be more indicative of child neglect. Parental alcohol or drug abuse, parental personal history of neglect, and parental stress greatly increase the odds of neglect. Parental depression doubles the odds of child neglect. However, more research needs to be done to better understand these risk factors and to identify others. Having a clearer understanding of the risk factors could lead to prevention and treatment, as it would allow for health care personnel to screen for high-risk children and intervene before it is too late. Screening could also be done in the schools and organized after school activities. Parenting classes have been shown to be an effective intervention strategy by decreasing parental stress and potential for abuse, but there has been limited research done on this approach. Parenting classes can be part of the corrective actions for parents found to be neglectful or abusive, but parenting classes may also be useful as a preventative measure, being taught in schools or readily available in higher-risk communities. More research has to be done to better define child abuse and neglect so that it can be effectively addressed and treated. PMID:25398462

  3. An observationally centred method to quantify local climate change as a distribution

    NASA Astrophysics Data System (ADS)

    Stainforth, David; Chapman, Sandra; Watkins, Nicholas

    2013-04-01

    For planning and adaptation, guidance on trends in local climate is needed at the specific thresholds relevant to particular impact or policy endeavours. This requires quantifying trends at specific quantiles in distributions of variables such as daily temperature or precipitation. These non-normal distributions vary both geographically and in time. The trends in the relevant quantiles may not simply follow the trend in the distribution mean. We present a method[1] for analysing local climatic timeseries data to assess which quantiles of the local climatic distribution show the greatest and most robust trends. We demonstrate this approach using E-OBS gridded data[2] timeseries of local daily temperature from specific locations across Europe over the last 60 years. Our method extracts the changing cumulative distribution function over time and uses a simple mathematical deconstruction of how the difference between two observations from two different time periods can be assigned to the combination of natural statistical variability and/or the consequences of secular climate change. This deconstruction facilitates an assessment of the sensitivity of different quantiles of the distributions to changing climate. Geographical location and temperature are treated as independent variables, we thus obtain as outputs how the trend or sensitivity varies with temperature (or occurrence likelihood), and with geographical location. These sensitivities are found to be geographically varying across Europe; as one would expect given the different influences on local climate between, say, Western Scotland and central Italy. We find as an output many regionally consistent patterns of response of potential value in adaptation planning. We discuss methods to quantify the robustness of these observed sensitivities and their statistical likelihood. This also quantifies the level of detail needed from climate models if they are to be used as tools to assess climate change impact. [1] S C Chapman, D A Stainforth, N W Watkins, 2013, On Estimating Local Long Term Climate Trends, Phil. Trans. R. Soc. A, in press [2] Haylock, M.R., N. Hofstra, A.M.G. Klein Tank, E.J. Klok, P.D. Jones and M. New. 2008: A European daily high-resolution gridded dataset of surface temperature and precipitation. J. Geophys. Res (Atmospheres), 113, D20119, doi:10.1029/2008JD10201

  4. [Quality of the clinical reports: observational study in Sassari].

    PubMed

    Virdis, A; Licheri, N; Ruiu, A

    2009-01-01

    Within the program of clinical risk management, and in particular in the phase of the "knowledge" of company reality, the work deals with the topic of the case history in Sassari' local health authority. A study is treated where, on a sample of about 400 cases history, four definite aspects are considered, in particular those that are regarded as the most important in the risk management and about medical responsability: 1) formal consent; 2) daily clinical allowance; 3) therapeutic card; 4) operating card. The results we got show the presence of a formal consent filled in correctly in 36 cases (9%), completed a daily allowance in 36 cases (9%), therapeutic card in 14 (3.5%) cases, operation card in 21 cases (19% su 116 surgical cases). These data, that have permitted to estimate the specific company reality as from pointed out critical states, show the necessity of working, with involvement of professional doctors, to build a history case model with clear and shared rules where you can clearly find the clinical path of a patient, where everything made is quoted and easily readable when necessary. PMID:20169826

  5. 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

  6. A cross-sectional observational study of helmet use among motorcyclists in Wa, Ghana.

    PubMed

    Akaateba, Millicent Awialie; Amoh-Gyimah, Richard; Yakubu, Ibrahim

    2014-03-01

    Motorcyclists' injuries and fatalities are a major public health concern in many developing countries including Ghana. This study therefore aimed to investigate the prevalence of helmet use among motorcyclists in Wa, Ghana. The method used involved a cross-sectional roadside observation at 12 randomly selected sites within and outside the CBD of Wa. A total of 14,467 motorcyclists made up of 11,360 riders and 3107 pillion riders were observed during the study period. Most observed riders (86.5%) and pillion riders (61.7%) were males. The overall prevalence of helmet use among the observed motorcyclists was 36.9% (95% CI: 36.1-37.7). Helmet use for riders was 45.8% (95% CI: 44.8-46.7) whilst that for pillion riders was 3.7% (95 CI: 3.0-4.4). Based on logistic regression analysis, higher helmet wearing rates were found to be significantly associated with female gender, weekdays, morning periods and at locations within the CBD. Riders at locations outside the CBD were about 7 times less likely to wear a helmet than riders within the CBD (48.9% compared to 42.3%; ?(2)(1)=49.526; p<0.001). The study concluded that despite the existence of a national helmet legislation that mandates the use of helmets by both riders and pillion riders on all roads in Ghana, helmet use is generally low in Wa. This suggests that all stakeholders in road safety should jointly intensify education on helmet use and pursue rigorous enforcement on all road types especially at locations outside the CBD to improve helmet use in Wa. PMID:24316503

  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. Comparative study on Kasisa Bhasma prepared by two different methods

    PubMed Central

    Rajput, Dhirajsingh; Tekale, G. S.; Patgiri, BJ

    2011-01-01

    Preparation of bhasma (calcined powder of metal/minerals) includes various processing steps like purification (Shodhana), levigation (Bhavana),calcinations cycle(Marana), improving quality and removing blemishes (Amritikarana) etc, processing of bhasma aims at formation of herbo-mineral complex molecule which can act in minimal dosage, palatable, easy for assimilation, highly efficacious with minimal or no complication. Although the most important equipment mentioned for Marana i.e. cow dung cakes and some type of woods are not only difficult to collect but also expensive and create pollution during puta and it's difficult task to give controlled heat in traditional method. Hence, a Modified Portable Bhasma Nirman Yantra (MPBNY) was prepared for puta (equipment for calcination) procedure which is easy to handle, portable and facilitate to supply controlled heat. A comparative study was conducted on Kasisa Bhasma prepared by traditional method and by using MPBNY with special reference to physico-chemical properties. The prepared Kasisa Bhasma was subjected to modern analytical parameters such as A.A.S. (Atomic Absorption Spectroscopy), X.R.D. (X-ray Diffraction) and Ayurvedic parameters eg. Rekhapurnatva (bhasma should enters in between lines of finger), Varitaratva (bhasma should float on the surface of water), Niramlatva (bitter less), Apunarbhava (bhasma should not regain its metallic nature after strong heating with jiggery, Abrus precatorius linn., honey and ghee) and Niruttha (bhasma should not regain its metallic nature after strong heating with silver). It was observed that Kasisa Bhasma of both methods possesses similar organoleptic as well as physico-chemical properties. PMID:23284208

  9. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 25, METHOD 602, PURGEABLE AROMATICS

    EPA Science Inventory

    The experimental design and the results of an interlaboratory study for an analytical method to detect purgeable aromatics in water are described herein. The method, EPA Method 602, Purgeable Aromatics, employs a purge-and-trap chromatographic technique for determination of seven...

  10. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 16, METHOD 606--PHTHALATE ESTERS

    EPA Science Inventory

    This report describes the results obtained and data analysis from an interlaboratory method study of EPA Method 606 (Phthalate Esters). The method is designed to analyze for six phthalate esters: dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, benzylbutyl phthalate, ...

  11. TOOLS AND METHODS FOR STUDIES IN COASTAL ECOLOGY

    E-print Network

    Sealey, Kathleen Sullivan

    TOOLS AND METHODS FOR STUDIES IN COASTAL ECOLOGY OF THE BAHAMAS Version 1.2. April 2006 #12;TOOLS AND METHODS IN COASTAL ECOLOGY 2006 2 Copyright 2006 K Sullivan Sealey Contributing Authors Kathleen Semon for Coastal Ecological Studies of The Bahamas. University of Miami, Coral Gables, Fl. 33124. 111 pp. #12;TOOLS

  12. Studying Participation Networks in Collaboration Using Mixed Methods

    ERIC Educational Resources Information Center

    Martinez, Alejandra; Dimitriadis, Yannis; Gomez-Sanchez, Eduardo; Rubia-Avi, Bartolome; Jorrin-Abellan, Ivan; Marcos, Jose A.

    2006-01-01

    This paper describes the application of a mixed-evaluation method, published elsewhere, to three different learning scenarios. The method defines how to combine social network analysis with qualitative and quantitative analysis in order to study participatory aspects of learning in CSCL contexts. The three case studies include a course-long,…

  13. NATO PILOT STUDY ON ADVANCED CANCER RISK ASSESSMENT METHODS

    EPA Science Inventory

    NCEA scientists are participating in a study of advanced cancer risk assessment methods, conducted under the auspices of NATO's Committee on the Challenges of Modern Society. The product will be a book of case studies that illustrate advanced cancer risk assessment methods, avail...

  14. Use of the Transformative Framework in Mixed Methods Studies

    ERIC Educational Resources Information Center

    Sweetman, David; Badiee, Manijeh; Creswell, John W.

    2010-01-01

    A concern exists that mixed methods studies do not contain advocacy stances. Preliminary evidence suggests that this is not the case, but to address this issue in more depth the authors examined 13 mixed methods studies that contained an advocacy, transformative lens. Such a lens consisted of incorporating intent to advocate for an improvement in…

  15. Statistical Methods for studying Genetic Variation in Populations

    E-print Network

    Statistical Methods for studying Genetic Variation in Populations Suyash Shringarpure August 2012 CMU-ML-12-105 #12;#12;Statistical Methods for studying Genetic Variation in Populations Suyash Shringarpure CMU-ML-12-105 August 2012 Machine Learning Department School of Computer Science Carnegie Mellon

  16. Nuclear-based methods for the study of selenium

    SciTech Connect

    Spyrou, N.M.; Akanle, O.A.; Dhani, A. )

    1988-01-01

    The essentiality of selenium to the human being and in particular its deficiency state, associated with prolonged inadequate dietary intake, have received considerable attention. In addition, the possible relationship between selenium and cancer and the claim that selenium may possess cancer-prevention properties have focused research effort. It has been observed in a number of studies on laboratory animals that selenium supplementation protects the animals against carcinogen-induced neoplastic growth in various organ sites, reduces the incidence of spontaneous mammary tumors, and suppresses the growth of transplanted tumor cells. In these research programs on the relationship between trace element levels and senile dementia and depression and the elemental changes in blood associated with selenium supplementation in a normal group of volunteers, it became obvious that in addition to establishing normal levels of elements in the population of interest, there was a more fundamental requirement for methods to be developed that would allow the study of the distribution of selenium in the body and its binding sites. The authors propose emission tomography and perturbed angular correlation as techniques worth exploring.

  17. 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

  18. "Needs Expressed" and "Offers of Care": An Observational Study of Mothers with Somatisation Disorder and Their Children

    ERIC Educational Resources Information Center

    Bialas, Ivona; Craig, Tom K. J.

    2007-01-01

    Background: The abnormal illness behaviours characterising somatisation disorder may be learnt responses acquired through exposure to parental illness and health anxiety in childhood. In this observational study we explore this hypothesis by examining patterns of interaction in mothers and their school age children. Method: A sample of 136 mother…

  19. Physiological Measurements as Validation of Alertness Observations: An Exploratory Case Study of Three Individuals with Profound Intellectual and Multiple Disabilities

    ERIC Educational Resources Information Center

    Munde, Vera; Vlaskamp, Carla; Vos, Pieter; Maes, Bea; Ruijssenaars, Wied

    2012-01-01

    Although observation largely takes into account the needs and abilities of individuals with profound intellectual and multiple disabilities, several difficulties are related to this assessment method as well. Our aim in this study was to investigate what possibilities the use of physiological measurements make available to validate alertness…

  20. 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...

  1. What Are the Consequences if the Assumption of Independent Observations Is Violated in Reliability Generalization Meta-Analysis Studies?

    ERIC Educational Resources Information Center

    Romano, Jeanine L.; Kromrey, Jeffrey D.

    2009-01-01

    This study was conducted to evaluate alternative analysis strategies for the meta-analysis method of reliability generalization when the reliability estimates are not statistically independent. Five approaches to dealing with the violation of independence were implemented: ignoring the violation and treating each observation as independent,…

  2. METHODS ADVANCEMENT FOR MILK ANALYSIS: THE MAMA STUDY

    EPA Science Inventory

    The Methods Advancement for Milk Analysis (MAMA) study was designed by US EPA and CDC investigators to provide data to support the technological and study design needs of the proposed National Children=s Study (NCS). The NCS is a multi-Agency-sponsored study, authorized under the...

  3. Prescribing Patterns of Drugs in Acute Respiratory Distress Syndrome (ARDS): An Observational Study

    PubMed Central

    Rao, Shobitha; Chogtu, Bharti

    2015-01-01

    Introduction: Acute respiratory distress syndrome (ARDS) is characterized by acute respiratory failure and is associated with wide range of clinical disorders. Controversy prevails over the pharmacological intervention in this disease. The aim of the study was to observe the prescribing pattern of drugs in patients with ARDS managed at a tertiary care hospital. Materials and Methods: This observational study was conducted at tertiary care hospital in India. Data of patients admitted from January 2010 to December 2012 was collected. Patients aged more than 18 years admitted in ICU, who were diagnosed to have ARDS during the study period, were included. A total of 150 patients of ARDS were selected. Data was collected as per the pre designed proforma and it included patients’ age, gender, clinical disorders precipitating ARDS, prescribing pattern of drugs and outcome. The data of the subjects was collected till discharge from hospital or death. Results: Infection was the cause of ARDS in 81.3% (n=122) of subjects. Antibiotics were prescribed in all the subjects and beta-lactams were prescribed in 97.3% (n=146). 41.3% (n=62) were prescribed corticosteroids, 39.3% (n=59) diuretics and 89.3% (n=134) intravenous fluids. Conclusion: The outcome of patients on different pharmacological treatment did not show any statistically significant difference. PMID:25859465

  4. Event-by-event study of neutron observables in spontaneous and thermal fission

    SciTech Connect

    Vogt, R; Randrup, J

    2011-09-14

    The event-by-event fission model FREYA is extended to spontaneous fission of actinides and a variety of neutron observables are studied for spontaneous fission and fission induced by thermal neutrons with a view towards possible applications for SNM detection. We have shown that event-by-event models of fission, such as FREYA, provide a powerful tool for studying fission neutron correlations. Our results demonstrate that these correlations are significant and exhibit a dependence on the fissioning nucleus. Since our method is phenomenological in nature, good input data are especially important. Some of the measurements employed in FREYA are rather old and statistics limited. It would be useful to repeat some of these studies with modern detector techniques. In addition, most experiments made to date have not made simultaneous measurements of the fission products and the prompt observables, such as neutron and photons. Such data, while obviously more challenging to obtain, would be valuable for achieving a more complete understanding of the fission process.

  5. 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.

  6. 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. PMID:26150782

  7. Observation and imitation of actions performed by humans, androids, and robots: an EMG study.

    PubMed

    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. PMID:26150782

  8. 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.

  9. Smoking close to others and butt littering at bus stops: pilot observational study

    PubMed Central

    Oliver, Jane; Thomson, George

    2014-01-01

    Background. Transportation settings such as bus stops and train station platforms are increasingly the target for new smokefree legislation. Relevant issues include secondhand smoke exposure, nuisance, litter, fire risks and the normalization of smoking. We therefore aimed to pilot study aspects of smoking behavior and butt disposal at bus stops. Methods. Systematic observation of smoking and butt disposal by smokers at bus stops. The selection of 11 sites was a mix of convenience and purposeful (bus stops on main routes) in two New Zealand cities. Results. During 27 h of observation, a total of 112 lit cigarettes were observed being smoked. Smoking occurred in the presence of: just adults (46%), both young people and adults (44%), just young people (6%) and alone (5%). An average of 6.3 adults and 3.8 young people were present at the bus stops while smoking occurred, at average minimum distances of 1.7 and 2.2 m respectively. In bus stops that included an enclosed shelter, 33% of the cigarettes were smoked inside the shelter with others present. Littering was the major form of cigarette disposal with 84% of cigarettes smoked being littered (95% CI; 77%–90%). Also, 4% of disposals were into vegetation, which may pose a fire risk. Conclusions. This pilot study is limited by its small size and various methodological aspects but it appears to be a first attempt to provide observational evidence around smoking at bus stops. The issues described could be considered by policy makers who are investigating national smokefree laws or by-laws covering transportation settings. PMID:24688851

  10. Smoking close to others and butt littering at bus stops: pilot observational study.

    PubMed

    Wilson, Nick; Oliver, Jane; Thomson, George

    2014-01-01

    Background. Transportation settings such as bus stops and train station platforms are increasingly the target for new smokefree legislation. Relevant issues include secondhand smoke exposure, nuisance, litter, fire risks and the normalization of smoking. We therefore aimed to pilot study aspects of smoking behavior and butt disposal at bus stops. Methods. Systematic observation of smoking and butt disposal by smokers at bus stops. The selection of 11 sites was a mix of convenience and purposeful (bus stops on main routes) in two New Zealand cities. Results. During 27 h of observation, a total of 112 lit cigarettes were observed being smoked. Smoking occurred in the presence of: just adults (46%), both young people and adults (44%), just young people (6%) and alone (5%). An average of 6.3 adults and 3.8 young people were present at the bus stops while smoking occurred, at average minimum distances of 1.7 and 2.2 m respectively. In bus stops that included an enclosed shelter, 33% of the cigarettes were smoked inside the shelter with others present. Littering was the major form of cigarette disposal with 84% of cigarettes smoked being littered (95% CI; 77%-90%). Also, 4% of disposals were into vegetation, which may pose a fire risk. Conclusions. This pilot study is limited by its small size and various methodological aspects but it appears to be a first attempt to provide observational evidence around smoking at bus stops. The issues described could be considered by policy makers who are investigating national smokefree laws or by-laws covering transportation settings. PMID:24688851

  11. Study of methods for greenways acquisition in city planning 

    E-print Network

    Griffin, Sven Troy

    2005-08-29

    -1 STUDY OF METHODS FOR GREENWAY ACQUISITION IN CITY PLANNING A Thesis by SVEN TROY GRIFFIN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... May 2005 Major Subject: Rangeland Ecology & Management STUDY OF METHODS FOR GREENWAY ACQUISITION IN CITY PLANNING A Thesis by SVEN TROY GRIFFIN Submitted to Texas A&M University in partial fulfillment of the requirements...

  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.

    1988-01-01

    The proper modeling of nonequilibrium gas dynamics is required in certain regimes of hypersonic flow. For inviscid flow this gives a system of conservation laws coupled with source terms representing the chemistry. Often a wide range of time scales is present in the problem, leading to numerical difficulties as in stiff systems of ordinary differential equations. Stability can be achieved by using implicit methods, but other numerical difficulties are observed. The behavior of typical numerical methods on a simple advection equation with a parameter-dependent source term was studied. Two approaches to incorporate the source term were utilized: MacCormack type predictor-corrector methods with flux limiters, and splitting methods in which the fluid dynamics and chemistry are handled in separate steps. Various comparisons over a wide range of parameter values were made. In the stiff case where the solution contains discontinuities, incorrect numerical propagation speeds are observed with all of the methods considered. This phenomenon is studied and explained.

  13. Metformin therapy and prostate cancer risk: a meta-analysis of observational studies

    PubMed Central

    Wu, Gang-Feng; Zhang, Xiao-Long; Luo, Zhen-Gang; Yan, Jia-Jun; Pan, Shou-Hua; Ying, Xiang-Rong; Pan, Jian-Gang; Zhang, Guan-Fu

    2015-01-01

    Objective: Several observational studies have shown that metformin therapy may modify the risk of prostate cancer. We carried out a meta-analysis of relevant studies evaluating the effect of metformin therapy on prostate cancer risk. Methods: We searched pubmed database (January 1966-February 2014) for case-control and cohort studies that assessed metformin therapy and prostate cancer risk. Two authors independently assessed eligibility and extracted data. Summary RRs was calculated using fixed-effects model or random-effects model. Heterogeneity among studies was examined using Q and I2 statistics. Results: We included six cohort studies and four case-control studies in the present meta-analysis, comprising 863,769 participants and 39,073 prostate cancer cases. The pooled RR of prostate cancer in relation to metformin therapy was 0.92 (95% CI: 0.84-1.02, P = 0.112). When we stratified the various studies by study type, we found that metformin therapy was associated with a significant reduced risk of prostate cancer among cohort studies (RR = 0.92, 95% CI [0.87, 0.96], P<0.001); however, no significant association was detected among case-control studies (RR = 0.95, 95% CI [0.78, 1.16], P = 0.632). There was also no indication of publication bias as suggested by Begg’s test (P = 0.421) and Egger’s test (P = 0.627). Conclusion: Our findings indicate that metformin therapy is not significantly associated with lower prostate cancer risk. PMID:26550231

  14. Development of a Method for the Observation of Lightning in Protoplanetary Disks Using Ion Lines

    E-print Network

    Muranushi, Takayuki; Inutsuka, Shu-ichiro; Nomura, Hideko; Okuzumi, Satoshi

    2015-01-01

    In this paper, we propose observational methods for detecting lightning in protoplanetary disks. We do so by calculating the critical electric field strength in the lightning matrix gas (LMG), the parts of the disk where the electric field is strong enough to cause lightning. That electric field accelerates multiple positive ion species to characteristic terminal velocities. In this paper, we present three distinct discharge models, with corresponding critical electric fields. We simulate the position-velocity diagrams and the integrated emission maps for the models. We calculate the measure of sensitivity values for detection of the models, and for distinguishing between the models. At the distance of TW-Hya (54pc), LMG that occupies $2\\pi$ in azimuth and $25 \\mathrm{au}

  15. 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...

  16. Peak Bagging of red giant stars observed by Kepler: first results with a new method based on Bayesian nested sampling

    NASA Astrophysics Data System (ADS)

    Corsaro, Enrico; De Ridder, Joris

    2015-09-01

    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. Efficiency 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-noise red giant stars by exploiting recent Kepler datasets and a new criterion for the detection of an oscillation mode based on the computation of the Bayesian evidence. Preliminary results for frequencies and lifetimes for single oscillation modes, together with acoustic glitches, are therefore presented.

  17. The Cross-Convolution Method for Interpreting SKS Splitting Observations, with Application to One and Two Layer Anisotropic Earth Models

    E-print Network

    Menke, William

    and Two Layer Anisotropic Earth Models William Menke Lamont-Doherty Earth Observatory of Columbia for determining anisotropic earth models using observations of split shear waves (such as SKS). The method the observed seismograms and a hypothetical earth model, and then varying the earth model so as to minimize

  18. Following Experts at Work in Their Own Information Spaces: Using Observational Methods To Develop Tools for the Digital Library.

    ERIC Educational Resources Information Center

    Gorman, Paul; Lavelle, Mary; Delcambre, Lois; Maier, David

    2002-01-01

    Offers an overview of the authors' experience using several observational methods to better understand one class of users, expert clinicians treating patients in hospital settings. Shows the evolution of understanding of the users and their information-handling tasks based on observations made in the field by a multidisciplinary research team, and…

  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.

    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. A Study Of Facial Asymmetries By The Stereometric Method

    NASA Astrophysics Data System (ADS)

    Crete, N.; Deloison, Y.; Mollard, R.

    1980-07-01

    In order to determine the part played in facial dissymmetry observed on a living person by the various constitutive elements of the cephalic tip (the soft parts - skin, muscles and the underlying bone structure) we undertook, using a biostereometric method, to evaluate asymmetries between homologous right and left dimensions on a living person's face and on a skeleton. While in an individual, a marked degree of facial dissymmetry can sometimes be observed; average differences between the right and left sides of the face may nethertheless balance out, and remain slight. Conventional anthropometrics techniques do not show up such slight values. With a view to securing a higher degree of accuracy, study of the stereometric technique of measurements. Using this technique, quasi imperceptible differences between the right and the left sides of the face on a living person as well as on a skeleton, together with variations in the orientation or angulation of anatomical segments in a three-dimensional space can be measured. We were thus able to detect, in a number of dry skulls, average differences of approxi-mately a millimetre between the two sides of the face which cannot be attributed to back of accuracy in measurements. Although statistically the difference are not always significant, the para-metric values of facial dimensions are invariably greater for the left side. On the other hand, for the sample of living subjects as a whole, the differences between homologous distances are not statistically significant. But it may be that, on a living subject, the experimenter is inclined to take measurements that are susceptible of symmetrization (for instance, the nasion in the median sagittal plane) whereas on a dry skull anatomical reference marks can be determined with the utmost accuracy. It may be inferred from there results that the softer parts tend, as a rule, to correct the dissymmetry of the underlying skeleton.

  1. The Golden Retriever Lifetime Study: establishing an observational cohort study with translational relevance for human health

    PubMed Central

    Guy, Michael K.; Page, Rodney L.; Jensen, Wayne A.; Olson, Patricia N.; Haworth, J. David; Searfoss, Erin E.; Brown, Diane E.

    2015-01-01

    The Golden Retriever Lifetime Study (GRLS) is the first prospective longitudinal study attempted in veterinary medicine to identify the major dietary, genetic and environmental risk factors for cancer and other important diseases in dogs. The GRLS is an observational study that will follow a cohort of 3000 purebred Golden Retrievers throughout their lives via annual online questionnaires from the dog owner and annual physical examinations and collection of biological samples by the primary care veterinarian. The field of comparative medicine investigating naturally occurring disorders in pets is specifically relevant to the many diseases that have a genetic basis for disease in both animals and humans, including cancer, blindness, metabolic and behavioural disorders and some neurodegenerative disorders. The opportunity for the GRLS to provide high-quality data for translational comparative medical initiatives in several disease categories is great. In particular, the opportunity to develop a lifetime dataset of lifestyle and activity, environmental exposure and diet history combined with simultaneous annual biological sample sets and detailed health outcomes will provide disease incidence data for this cohort of geographically dispersed dogs and associations with a wide variety of potential risk factors. The GRLS will provide a lifetime historical context, repeated biological sample sets and outcomes necessary to interrogate complex associations between genes and environmental influences and cancer. PMID:26056371

  2. 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

  3. Common Traffic Violations of Bus Drivers in Urban China: An Observational Study

    PubMed Central

    Yang, Rendong; Huang, Yuanxiu; Zhang, Lin; Ning, Peishan; Cheng, Xunjie; Schwebel, David C.

    2015-01-01

    Objective To report common traffic violations in bus drivers and the factors that influence those violations in urban China. Methods We conducted an observational study to record three types of traffic violations among bus drivers in Changsha City, China: illegal stopping at bus stations, violating traffic light signals, and distracted driving. The behaviors of bus drivers on 32 routes (20% of bus routes in the city) were observed. A two-level Poisson regression examined factors that predicted bus driver violations. Results The incidence of illegal stopping at bus stations was 20.2%. Illegal stopping was less frequent on weekends, sunny days, and at stations with cameras, with adjusted incidence rate ratios (IRRs) of 0.81, 0.65 and 0.89, respectively. The incidence of violating traffic light signals was 2.2%, and was lower on cloudy than sunny days (adjusted IRR: 0.60). The incidence of distracted driving was 3.3%. The incidence of distracted driving was less common on cloudy days, rainy or snowy days, and foggy/windy/dusty days compared to sunny days, with adjusted IRRs of 0.54, 0.55 and 0.07, respectively. Conclusion Traffic violations are common in bus drivers in urban China and they are associated with the date, weather, and presence of traffic cameras at bus station. Further studies are recommended to understand the behavioral mechanisms that may explain bus driver violations and to develop feasible prevention measures. PMID:26372105

  4. An Observational Study of the Interactions of Socially Withdrawn/Anxious Early Adolescents and Their Friends

    ERIC Educational Resources Information Center

    Schneider, Barry H.

    2009-01-01

    Background: The friendships of socially withdrawn/anxious children and early adolescents have been found to lack critical rewarding qualities. Observational research may help elucidate the obstacles they face in forming and maintaining high-quality friendships with sociable peers. Method: We observed the interactions of 38 socially withdrawn early…

  5. Mechanical spectrum study of glass transition by a composite method

    NASA Astrophysics Data System (ADS)

    Yuan, Y. H.; Zhang, L.; Wang, X. L.; Ying, X. N.; Yan, F.; Huang, Y. N.; Zhu, J. S.; Wang, Y. N.

    2009-11-01

    Normalized mechanical spectra of glycerol, 1,2-propanediol carbonate and poly(vinyl chloride)/di(2-ethyl-hexyl) phthalate (PVC/DOP) blends were studied in the temperature range from 100 to 300 K by a composite method. The dynamic glass transition was observed, which exhibits a peak of temperature-dependent loss modulus. The peak moves toward higher temperature with higher measuring frequency, which accords with the relaxation feature of the dynamic glass transition. Another characteristic temperature can be marked in the mechanical spectrum by the onset of storage modulus change, which is labeled as T gm. T gm is found to be nearly equal to the calorimetric glass transition temperature in glycerol, 1,2-propanediol carbonate and di(2-ethyl-hexyl) phthalate. As we expected, this onset temperature in the mechanical spectrum has an intimate relation with the calorimetric glass transition of materials, and it can be regarded as a representative when the calorimetric glass transition temperature is not available. Finally, normalized mechanical spectra of PVC/DOP blends with different PVC content were obtained and mechanical glass transition temperatures T gm were determined.

  6. Application of ground-penetrating-radar methods in hydrogeologic studies

    USGS Publications Warehouse

    Beres, Milan, Jr.; Haeni, F.P.

    1991-01-01

    A ground-penetrating-radar system was used to study selected stratified-drift deposits in Connecticut. Ground-penetrating radar is a surface-geophysical method that depends on the emission, transmission, reflection, and reception of an electromagnetic pulse and can produce continuous high-resolution profiles of the subsurface rapidly and efficiently. Traverse locations on land included a well field in the town of Mansfield, a sand and gravel pit and a farm overlying a potential aquifer in the town of Coventry, and Haddam Meadows State Park in the town of Haddam. Traverse locations on water included the Willimantic River in Coventry and Mansfield Hollow Lake in Mansfield. The penetration depth of the radar signal ranged from about 20 feet in fine-grained glaciolacustrine sediments to about 70 feet in coarse sand and gravel. Some land records in coarse-grained sediments show a distinct, continuous reflection from the water table about 5 to 11 feet below land surface. Parallel reflectors on the records are interpreted as fine-grained sediments. Hummocky or chaotic reflectors are interpreted as cross-bedded or coarse-grained sediments. Other features observed on some of the radar records include the till and bedrock surface. Records collected on water had distinct water-bottom multiples (more than one reflection) and diffraction patterns from boulders. The interpretation of the radar records, which required little or no processing, was verified by using lithologic logs from test holes located along some of the land traverses and near the water traverses.

  7. Why use DFT methods in the study of carbohydrates?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The recent advances in density functional theory (DFT) and computer technology allow us to study systems with more than 100 atoms routinely. This makes it feasible to study large carbohydrate molecules via quantum mechanical methods, whereas in the past, studies of carbohydrates were restricted to ...

  8. 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.

  9. Current Mathematical Methods Used in QSAR/QSPR Studies

    PubMed Central

    Liu, Peixun; Long, Wei

    2009-01-01

    This paper gives an overview of the mathematical methods currently used in quantitative structure-activity/property relationship (QASR/QSPR) studies. Recently, the mathematical methods applied to the regression of QASR/QSPR models are developing very fast, and new methods, such as Gene Expression Programming (GEP), Project Pursuit Regression (PPR) and Local Lazy Regression (LLR) have appeared on the QASR/QSPR stage. At the same time, the earlier methods, including Multiple Linear Regression (MLR), Partial Least Squares (PLS), Neural Networks (NN), Support Vector Machine (SVM) and so on, are being upgraded to improve their performance in QASR/QSPR studies. These new and upgraded methods and algorithms are described in detail, and their advantages and disadvantages are evaluated and discussed, to show their application potential in QASR/QSPR studies in the future. PMID:19564933

  10. A Study of Peer Tutors Using the Neurological Impress Method.

    ERIC Educational Resources Information Center

    McAllister, Elizabeth A.

    A study investigated the efficacy of using the neurological impress method in peer tutoring during reading instruction. The neurological impress reading method is a unison reading procedure in which the student and teacher or tutor read aloud simultaneously and quickly, with the student placed slightly in front of the teacher so that the teacher's…

  11. ELECTRON MICROSCOPE STUDIES OF CELLS BY THE METHOD OF REPLICAS

    PubMed Central

    Claude, Albert

    1949-01-01

    The method of replicas has been applied to the study with the electron microscope of blood cells and bacteria. The results indicate that the method can reveal details of intracellular structures. Nuclei can be perceived, and also cytoplasmic bodies such as mitochondria and vacuoles. PMID:18113914

  12. TRANSMISSION NETWORK PLANNING METHOD FOR COMPARATIVE STUDIES (JOURNAL VERSION)

    EPA Science Inventory

    An automated transmission network planning method for comparative studies is presented. This method employs logical steps that may closely parallel those taken in practice by the planning engineers. Use is made of a sensitivity matrix to simulate the engineers' experience in sele...

  13. Teacher Professionalism and Team Performance Pay: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Wells, Pamela; Combs, Julie P.; Bustamante, Rebecca M.

    2012-01-01

    The purpose of this mixed methods research study was to explore teachers' perceptions of their professional behaviors when they worked in schools that awarded team performance pay. Teachers' archival responses from two questionnaires were analyzed using mixed methods data analysis techniques (Year 1, n = 368; Year 2, n = 649). Most teachers had…

  14. [Current methods for studying the functional morphology of apud cells].

    PubMed

    Iuzhakov, V V; Ra?khlin, N T; Kvetno?, I M; Iakovleva, N D; Kurilets, E S; Manokhina, R P

    1996-01-01

    The paper reviews methods for studying functional morphology of endocrine cells histochemistry and immunohistochemistry, radioautography and methods of ultrastructural verification of secretory granules. Methodological approach is illustrated by the authors' results on the influence of ionizing radiation and tumor growth on the cells of the diffuse endocrine system. PMID:8712935

  15. Comparison of midwifery students’ satisfaction with direct observation of procedural skills and current methods in evaluation of procedural skills in Mashhad Nursing and Midwifery School

    PubMed Central

    Hoseini, BiBi Leila; Mazloum, Seyed Reza; Jafarnejad, Farzaneh; Foroughipour, Mohsen

    2013-01-01

    Background: The clinical evaluation, as one of the most important elements in medical education, must measure students’ competencies and abilities. The implementation of any assessment tool is basically dependent on the acceptance of students. This study tried to assess midwifery students’ satisfaction with Direct Observation of Procedural Skills (DOPS) and current clinical evaluation methods. Materials and Methods: This quasi-experimental study was conducted in the university hospitals affiliated to Mashhad University of Medical Sciences. The subjects comprised 67 undergraduate midwifery students selected by convenience sampling and allocated to control and intervention groups according to the training transposition. Current method was performed in the control group, and DOPS was conducted in the intervention group. The applied tools included DOPS rating scales, logbook, and satisfaction questionnaires with clinical evaluation methods. Validity and reliability of these tools were approved. At the end of training, students’ satisfaction with the evaluation methods was assessed by the mentioned tools. The data were analyzed by descriptive and analytical statistics. Results: Satisfaction mean scores of midwifery students with DOPS and current methods were 76.7 ± 12.9 and 62.6 ± 14.7 (out of 100), respectively. DOPS students’ satisfaction mean score was significantly higher than the score obtained in current method (P < 0.000). The most satisfactory domains in the current method were “consistence with learning objectives” (71.2 ± 14.9) and “objectiveness” in DOPS (87.9 ± 15.0). In contrast, the least satisfactory domains in the current method were “interested in applying the method” (57.8 ± 26.5) and “number of assessments for each skill” (58.8 ± 25.9) in DOPS method. Conclusions: This study showed that DOPS method is associated with greater students’ satisfaction. Since the students’ satisfaction with the current method was also acceptable, we recommend combining this new clinical evaluation method with the current method, which covers its weaknesses, to promote the students’ satisfaction with clinical evaluation methods in a perfect manner. PMID:23983736

  16. 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),…

  17. First Year Wilkinson Microwave Anisotropy Probe(WMAP) Observations: Data Processing Methods and Systematic Errors Limits

    NASA Technical Reports Server (NTRS)

    Hinshaw, G.; Barnes, C.; Bennett, C. L.; Greason, M. R.; Halpern, M.; Hill, R. S.; Jarosik, N.; Kogut, A.; Limon, M.; Meyer, S. S.

    2003-01-01

    We describe the calibration and data processing methods used to generate full-sky maps of the cosmic microwave background (CMB) from the first year of Wilkinson Microwave Anisotropy Probe (WMAP) observations. Detailed limits on residual systematic errors are assigned based largely on analyses of the flight data supplemented, where necessary, with results from ground tests. The data are calibrated in flight using the dipole modulation of the CMB due to the observatory's motion around the Sun. This constitutes a full-beam calibration source. An iterative algorithm simultaneously fits the time-ordered data to obtain calibration parameters and pixelized sky map temperatures. The noise properties are determined by analyzing the time-ordered data with this sky signal estimate subtracted. Based on this, we apply a pre-whitening filter to the time-ordered data to remove a low level of l/f noise. We infer and correct for a small (approx. 1 %) transmission imbalance between the two sky inputs to each differential radiometer, and we subtract a small sidelobe correction from the 23 GHz (K band) map prior to further analysis. No other systematic error corrections are applied to the data. Calibration and baseline artifacts, including the response to environmental perturbations, are negligible. Systematic uncertainties are comparable to statistical uncertainties in the characterization of the beam response. Both are accounted for in the covariance matrix of the window function and are propagated to uncertainties in the final power spectrum. We characterize the combined upper limits to residual systematic uncertainties through the pixel covariance matrix.

  18. 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

  19. Environmental Polychlorinated Biphenyl Exposure and Breast Cancer Risk: A Meta-Analysis of Observational Studies

    PubMed Central

    Zhang, Jingwen; Huang, Yue; Wang, Xiaoling; Lin, Kun; Wu, Kusheng

    2015-01-01

    Background Association between polychlorinated biphenyl (PCB) exposure and breast cancer risk has been widely studied, but the results remain controversial. We performed a meta-analysis to evaluate the evidences from observational studies on PCB exposure and breast cancer risk. Methods Relevant studies with data on internal PCB dose were identified from PubMed, EMBASE, CBM and CNKI databases through November 2014. Multivariable-adjusted odds ratio (OR) with 95% confidence intervals (CIs) were applied to assess the association between PCB exposure and breast cancer risk. Heterogeneity test, sensitivity analysis, subgroup analysis and publication bias test were also performed. To further explore the association between specific groups of PCB congeners and breast cancer, we examined the PCB congeners classified, according to their structural, biological and pharmacokinetics properties, as group I (potentially estrogenic), group II (potentially anti-estrogenic and immunotoxic, dioxin-like), and group III (phenobarbital, CYP1A and CYP2B inducers, biologically persistent). Results Of 660 studies screened, 25 studies which met criteria were selected, involving a total of 12866 participants (6088 cases and 6778 controls) from eight countries. The results showed that the risk of breast cancer was associated with group II (OR = 1.23, 95% CI: 1.08–1.40) and group III (OR = 1.25, 95% CI: 1.09–1.43) PCBs, but not with group I (OR = 1.10, 95%CI: 0.97–1.24) PCBs or total PCB exposure (OR = 1.09, 95%CI: 0.97–1.22). Conclusions Our meta-analysis based on the selected studies found group II and group III PCB exposure might contribute to the risk of breast cancer. More studies in developing countries with higher PCB levels are needed, as well as studies to explore the relationships between mixtures of organochlorine compounds and breast cancer risk. PMID:26555153

  20. Incidence of infectious diseases in infants fed follow-on formula containing synbiotics: an observational study

    PubMed Central

    Picaud, Jean-Charles; Chapalain, Véronique; Paineau, Damien; Zourabichvili, Othar; Bornet, Francis RJ; Duhamel, Jean-François

    2010-01-01

    Aim Infectious diseases in infants are a major public health issue. Synbiotic-enriched formulas (EF) are intended to mimic the beneficial effects of human milk on infectious diseases. We performed an observational study in infants switching to follow-on formula to determine the effects of synbiotic-enriched formula compared to standard formula (SF). Methods We recorded family characteristics, medical history and growth data, as well as the symptoms, severity and treatment of infectious diseases. Main outcome measures were compared after adjustments for baseline characteristics. Results Between January and June 2007, 771 healthy infants were included in the study; 35.4% experienced at least one infectious disease during the 3-month study period. The most common were upper respiratory tract (24.1%), otitis (6.6%) and gastrointestinal infectious diseases (5.0%). Infants fed synbiotic-enriched formula had fewer infectious diseases overall (EF: 31.0%; SF: 40.6%; p = 0.005) and significantly fewer gastrointestinal infectious diseases (EF: 3.5%; SF: 6.8%; p = 0.03). During follow-up, weight gain was significantly higher (p = 0.0467) in infants fed synbiotic-enriched formula (18.3 ± 8.7 g/day) versus SF (16.9 ± 7.5 g/day). Conclusions Supplementation with synbiotics may have beneficial effects on the incidence of infectious disease and growth in infants. Further studies are needed determine optimal doses and composition of synbiotics in infant formula. PMID:20560895

  1. Study design and methods of the Ansan Geriatric Study (AGE study)

    PubMed Central

    Han, Changsu; Jo, Sangmee Ahn; Kim, Nan Hee; Jo, Inho; Park, Moon Ho

    2009-01-01

    Background The overall objective of the Ansan Geriatric Study (AGE study) was to describe the prevalence, incidence, and related risk factors for geriatric diseases in elderly Koreans. Methods/Design The AGE study was designed as a population-based prospective cohort study on health, aging, and common geriatric diseases of elderly Koreans aged 60 to 84 years. The inception cohort was recruited in May 2002. The first-wave and second-wave studies were performed using uniform and structured procedures. At the screening study, 2,767 participants were enrolled. Participants (1391 in the first wave study and 841 in the second wave study) were recruited and completed the evaluation. The prevalence of geriatric disease and related factors in elderly Koreans were estimated. Discussion Here, we report the design and sampling participants, measurement tools, and characteristics of the AGE study. This cohort study will allow a detailed study of the longitudinal comprehensive data on health information of elderly Koreans, thereby contributing to policy formulation and planning of health, welfare management, and other social services in Korea. PMID:19236723

  2. Trough colistin plasma level is an independent risk factor for nephrotoxicity: a prospective observational cohort study

    PubMed Central

    2013-01-01

    Background Data regarding the most efficacious and least toxic schedules for the use of colistin are scarce. The aim of this study was to determine the incidence and the potential risk factors of colistin-associated nephrotoxicity including colistin plasma levels. Methods A prospective observational cohort study was conducted for over one year in patients receiving intravenous colistin methanesulfonate sodium (CMS). Blood samples for colistin plasma levels were collected immediately before (Cmin) and 30 minutes after CMS infusion (Cmax). Renal function was assessed at baseline, on day 7 and at the end of treatment (EOT). Severity of acute kidney injury (AKI) was defined by the RIFLE (risk, injury, failure, loss, and end-stage kidney disease) criteria. Results One hundred and two patients met the inclusion criteria. AKI related to CMS treatment on day 7 and at the end of treatment (EOT) was observed in 26 (25.5%) and 50 (49.0%) patients, respectively. At day 7, Cmin (OR, 4.63 [2.33-9.20]; P < 0.001) was the only independent predictor of AKI. At EOT, the Charlson score (OR 1.26 [1.01-1.57]; P = 0.036), Cmin (OR 2.14 [1.33-3.42]; P = 0.002), and concomitant treatment with ? 2 nephrotoxic drugs (OR 2.61 [1.0-6.8]; P = 0.049) were independent risk factors for AKI. When Cmin was evaluated as a categorical variable, the breakpoints that better predicted AKI were 3.33 mg/L (P < 0.001) on day 7 and 2.42 mg/L (P < 0.001) at EOT. Conclusions When using the RIFLE criteria, colistin-related nephrotoxicity is observed in a high percentage of patients. Cmin levels are predictive of AKI. Patients who receive intravenous colistin should be closely monitored and Cmin might be a new useful tool to predict AKI. PMID:23957376

  3. 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

  4. Impact of social and technological distraction on pedestrian crossing behaviour: an observational study

    PubMed Central

    Thompson, Leah L; Rivara, Frederick P; Ayyagari, Rajiv C; Ebel, Beth E

    2013-01-01

    Objectives The objective of the present work was to study the impact of technological and social distraction on cautionary behaviours and crossing times in pedestrians. Methods Pedestrians were observed at 20 high-risk intersections during 1 of 3 randomly assigned time windows in 2012. Observers recorded demographic and behavioural information, including use of a mobile device (talking on the phone, text messaging, or listening to music). We examined the association between distraction and crossing behaviours, adjusting for age and gender. All multivariate analyses were conducted with random effect logistic regression (binary outcomes) and random effect linear regression (continuous outcomes), accounting for clustering by site. Results Observers recorded crossing behaviours for 1102 pedestrians. Nearly one-third (29.8%) of all pedestrians performed a distracting activity while crossing. Distractions included listening to music (11.2%), text messaging (7.3%) and using a handheld phone (6.2%). Text messaging, mobile phone use and talking with a companion increased crossing time. Texting pedestrians took 1.87 additional seconds (18.0%) to cross the average intersection (3.4 lanes), compared to undistracted pedestrians. Texting pedestrians were 3.9 times more likely than undistracted pedestrians to display at least 1 unsafe crossing behaviour (disobeying the lights, crossing mid-intersection, or failing to look both ways). Pedestrians listening to music walked more than half a second (0.54) faster across the average intersection than undistracted pedestrians. Conclusions Distracting activity is common among pedestrians, even while crossing intersections. Technological and social distractions increase crossing times, with text messaging associated with the highest risk. Our findings suggest the need for intervention studies to reduce risk of pedestrian injury. PMID:23243104

  5. Statistical Track-Before-Detect Methods Applied to Faint Optical Observations of Resident Space Objects

    NASA Astrophysics Data System (ADS)

    Fujimoto, K.; Yanagisawa, T.; Uetsuhara, M.

    Automated detection and tracking of faint objects in optical, or bearing-only, sensor imagery is a topic of immense interest in space surveillance. Robust methods in this realm will lead to better space situational awareness (SSA) while reducing the cost of sensors and optics. They are especially relevant in the search for high area-to-mass ratio (HAMR) objects, as their apparent brightness can change significantly over time. A track-before-detect (TBD) approach has been shown to be suitable for faint, low signal-to-noise ratio (SNR) images of resident space objects (RSOs). TBD does not rely upon the extraction of feature points within the image based on some thresholding criteria, but rather directly takes as input the intensity information from the image file. Not only is all of the available information from the image used, TBD avoids the computational intractability of the conventional feature-based line detection (i.e., "string of pearls") approach to track detection for low SNR data. Implementation of TBD rooted in finite set statistics (FISST) theory has been proposed recently by Vo, et al. Compared to other TBD methods applied so far to SSA, such as the stacking method or multi-pass multi-period denoising, the FISST approach is statistically rigorous and has been shown to be more computationally efficient, thus paving the path toward on-line processing. In this paper, we intend to apply a multi-Bernoulli filter to actual CCD imagery of RSOs. The multi-Bernoulli filter can explicitly account for the birth and death of multiple targets in a measurement arc. TBD is achieved via a sequential Monte Carlo implementation. Preliminary results with simulated single-target data indicate that a Bernoulli filter can successfully track and detect objects with measurement SNR as low as 2.4. Although the advent of fast-cadence scientific CMOS sensors have made the automation of faint object detection a realistic goal, it is nonetheless a difficult goal, as measurements arcs in space surveillance are often both short and sparse. FISST methodologies have been applied to the general problem of SSA by many authors, but they generally focus on tracking scenarios with long arcs or assume that line detection is tractable. We will instead focus this work on estimating sensor-level kinematics of RSOs for low SNR too-short arc observations. Once said estimate is made available, track association and simultaneous initial orbit determination may be achieved via any number of proposed solutions to the too-short arc problem, such as those incorporating the admissible region. We show that the benefit of combining FISST-based TBD with too-short arc association goes both ways; i.e., the former provides consistent statistics regarding bearing-only measurements, whereas the latter makes better use of the precise dynamical models nominally applicable to RSOs in orbit determination.

  6. 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.

  7. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 22. METHOD 612-CHLORINATED HYDROCARBONS

    EPA Science Inventory

    An interlaboratory study in which 20 laboratories participated was conducted to provide precision and accuracy statements for the proposed EPA Method 612 - Chlorinated Hydrocarbons for measuring concentrations of the Category 3 chemicals hexachloroethane, hexachlorobutadiene, 2-c...

  8. 75 FR 3237 - Proposed Collection; Comment Request; Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-20

    ... Observational Study SUMMARY: In compliance with the requirement of Section 3506(c)(2)(A) of the Paperwork... approval. Proposed Collection Title: The Women's Health Initiative (WHI) Observational Study. Type of Information Collection Request: Revision OMB 0925- 0414. Need and Use of Information Collection: This...

  9. 78 FR 8152 - Proposed Collection; Comment Request: Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ... Observational Study SUMMARY: In compliance with the requirement of Section 3506(c)(2)(A) of the Paperwork... approval. Proposed Collection: Title: The Women's Health Initiative (WHI) Observational Study. Type of Information Collection Request: Revision OMB 0925-0414. Need and Use of Information Collection: This...

  10. Observational Child Study: An Empirical Analysis of Recent Trends and Directions.

    ERIC Educational Resources Information Center

    Susman, Elizabeth J.; And Others

    The analysis reported here examined the progress of observational child study from 1960 through 1975. Naturalistic observational studies were described as heuristic, highly realistic, relevant to important social problems and oriented toward significant theoretical issues. Fifteen journals encompassing child development, clinical and educational…

  11. A complete radio study of SNR G15.4+0.1 from new GMRT observations

    NASA Astrophysics Data System (ADS)

    Supan, L.; Castelletti, G.; Joshi, B. C.; Surnis, M. P.; Supanitsky, D.

    2015-04-01

    Aims: The supernova remnant (SNR) G15.4+0.1 is considered to be the possible counterpart of the ?-ray source HESS J1818-154. With the goal of getting a complete view of this remnant and understanding the nature of the ?-ray flux, we conducted a detailed radio study that includes the search for pulsations and a model of the broadband emission for the SNR G15.4+0.1/HESS J1818-154 system. Methods: Low-frequency imaging at 624 MHz and pulsar observations at 624 and 1404 MHz towards G15.4+0.1 were carried out with the Giant Metrewave Radio Telescope (GMRT). We correlated the new radio data with observations of the source at X-ray and infrared wavelengths from XMM-Newton and Herschel observatories, respectively. To characterize the neutral hydrogen (HI) medium towards G15.4+0.1, we used data from the Southern Galactic Plane Survey. We modelled the spectral energy distribution (SED) using both hadronic and leptonic scenarios. Results: From the combination of the new GMRT observations with existing data, we derived a continuum spectral index ? = -0.62 ± 0.03 for the whole remnant. The local synchrotron spectra of G15.4+0.1, calculated from the combination of the GMRT data with 330 MHz observations from the Very Large Array, tends to be flatter in the central part of the remnant, accompanying the region where the blast wave is impinging molecular gas. No spectral index trace was found indicating the radio counterpart to the pulsar wind nebula proposed from X-ray observations. In addition, the search for radio pulsations yielded negative results. Emission at far-infrared wavelengths is observed in the region where the SNR shock is interacting with dense molecular clumps. We also identified HI features forming a shell that wraps most of the outer border of G15.4+0.1. Characteristic parameters were estimated for the shocked HI gas. We found that either a purely hadronic or leptonic model is compatible with the broadband emission known so far.

  12. Detection method and observed data of high-energy gamma rays under the influence of quantum gravity

    SciTech Connect

    Kifune, T.

    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.

  13. Study methods, recruitment, socio-demographic findings and demographic representativeness in the OPPERA study

    PubMed Central

    Slade, Gary D.; Bair, Eric; By, Kunthel; Mulkey, Flora; Baraian, Cristina; Rothwell, Rebecca; Reynolds, Maria; Miller, Vanessa; Gonzalez, Yoly; Gordon, Sharon; Ribeiro-Dasilva, Margarete; Lim, Pei Feng; Greenspan, Joel D; Dubner, Ron; Fillingim, Roger B; Diatchenko, Luda; Maixner, William; Dampier, Dawn; Knott, Charles; Ohrbach, Richard

    2011-01-01

    This paper describes methods used in the project “Orofacial Pain Prospective Evaluation and Risk Assessment” (OPPERA) and evaluates socio-demographic characteristics associated with temporomandibular disorders (TMD) in the OPPERA case-control study. Representativeness was investigated by comparing socio-demographic profiles of OPPERA participants with population census profiles of counties near study sites and by comparing age- and gender-associations with TMD in OPPERA and the 2007-09 US National Health Interview Survey. Volunteers aged 18-44 years were recruited at four US study sites: 3,263 people without TMD were enrolled into the prospective cohort study; 1,633 of them were selected as controls for the baseline case-control study. Cases were 185 volunteers with examiner-classified TMD. Distributions of some demographic characteristics among OPPERA participants differed from census profiles, although there was less difference in socio-economic profiles. Odds of TMD was associated with greater age in this 18-44 year range; females had three times the odds of TMD as males; and relative to non-Hispanic-Whites, other racial groups had one-fifth the odds of TMD. Age- and gender-associations with chronic TMD were strikingly similar to associations observed in the US population. Assessments of representativeness in this demographically diverse group of community volunteers suggest that OPPERA case-control findings have good internal validity. PMID:22074749

  14. 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.

  15. Assessment of methods of homicides in a Brazilian city: a preliminary study.

    PubMed

    Martin, C C; Melki, J A; Guimarães, M A

    1999-11-22

    Homicides in the city of Ribeirão Preto, state of São Paulo, Brazil, were analyzed with regard to methods (firearms or others) and gender, in a retrospective study from 1993 to 1997. There was a progressive increase in the number of homicides, mainly after 1995, with an increment of 86.6% in 1997 in comparison to 1993. The incidence of homicides was higher among males, with firearms being the most common method in this group since 1993. In addition, a 10% increase in this method was observed since 1995, in association with a proportional reduction in the use of other methods. The incidence of homicides among females remained stable until 1996 and increased by 51.3% in 1997. Simultaneously, firearms have become the most common method among female victims (71.4%), pattern similar to that observed among males. Attention is drawn to the social and economic conditions and their relationships with drug traffic in the city. PMID:10629965

  16. 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.

  17. Toward new scientific observations from GPS occultations: advances in retrieval methods

    NASA Astrophysics Data System (ADS)

    Mannucci, Anthony J.; Ao, Chi-On; Hajj, George A.; Iijima, Byron A.; de la Torre-Juarez, Manuel; Meehan, Thomas K.; Schroeder, Thomas

    2004-12-01

    Atmospheric soundings using signals received in low Earth orbit from Global Positioning System (GPS) satellite transmissions are widely recognized as important data for establishing a precise climate record of upper-air temperatures, due to their self-calibrating nature and all-weather acquisition. More recently, advances in retrieval methods using the same GPS data have opened the possibility of new scientific studies related to atmospheric processes and climate change. We will present recent innovations in extracting scientifically useful information from the phase and amplitude of received GPS transmissions, and discuss the technical challenges that need to be overcome to achieve new scientific results. Promising areas being pursued include: remote sensing of the planetary boundary layer from space, important for understanding ocean-atmosphere coupling; retrieving tropopause temperature structure at high vertical resolution, important for understanding troposphere-stratosphere exchange mechanisms and the role of convection; high accuracy and precision of upper altitude (25+ km) retrievals in the stratosphere. Using an end-to-end simulator recently developed at JPL, we will investigate in realistic detail the relationship between the atmospheric state and retrieved scientific parameters, and discuss retrieval research needed to address new scientific applications.

  18. Asthma changes at a pediatric intensive care unit after 10 years: Observational study

    PubMed Central

    Al-Eyadhy, Ayman A.; Temsah, Mohamad-Hani; Alhaboob, Ali A. N.; Aldubayan, Abdulmalik K.; Almousa, Nasser A.; Alsharidah, Abdulrahman M.; Alangari, Mohammed I.; Alshaya, Abdulrahman M.

    2015-01-01

    OBJECTIVES: To describe the change in the management, and outcome of children with acute severe asthma (ASA) admitted to Pediatric Intensive Care Unit (PICU) at tertiary institute, as compared to previously published report in 2003. METHODS: This is a retrospective observational study. All consecutive pediatric ASA patients who were admitted to PICU during the study period were included. The data were extracted from PICU database and medical records. The Cohort in this study (2013 Cohort) was compared with the Cohort of ASA, which was published in 2003 from the same institution (2003 Cohort). RESULTS: In comparison to previous 2003 Cohort, current Cohort (2013) revealed higher mean age (5.5 vs. 3.6 years; P ? 0.001), higher rate of PICU admission (20.3% vs. 3.6%; P ? 0.007), less patients who received maintenance inhaled steroids (43.3% vs. 62.4%; P ? 0.03), less patients with pH <7.3 (17.9% vs. 42.9%; P ? 0.001). There were more patients in 2013 Cohort who received: Inhaled Ipratropium bromide (97% vs. 68%; P ? 0.001), intravenous magnesium sulfate (68.2% vs. none), intravenous salbutamol (13.6% vs. 3.6%; P ? 0.015), and noninvasive ventilation (NIV) (35.8% vs. none) while no patients were treated with theophylline (none vs. 62.5%). The median length of stay (LOS) was 2 days while mean LOS was half a day longer in the 2013 Cohort. None of our patients required intubation, and there was no mortality. CONCLUSION: We observed slight shift toward older age, considerably increased the rate of PICU admission, increased utilization of Ipratropium bromide, magnesium sulfate, and NIV as important modalities of treatment.

  19. A Study of Variance Estimation Methods. Working Paper Series.

    ERIC Educational Resources Information Center

    Zhang, Fan; Weng, Stanley; Salvucci, Sameena; Hu, Ming-xiu

    This working paper contains reports of five studies of variance estimation methods. The first, An Empirical Study of Poststratified Estimator, by Fan Zhang uses data from the National Household Education Survey to illustrate use of poststratified estimation. The second paper, BRR Variance Estimation Using BPLX Hadamard Procedure, by Stanley Weng…

  20. Safety of Intravenous Application of Mistletoe (Viscum album L.) Preparations in Oncology: An Observational Study.

    PubMed

    Steele, Megan L; Axtner, Jan; Happe, Antje; Kröz, Matthias; Matthes, Harald; Schad, Friedemann

    2014-01-01

    Background. Traditional mistletoe therapy in cancer patients involves subcutaneous applications of Viscum album L. preparations, with doses slowly increasing based on patient responses. Intravenous infusion of high doses may improve therapeutic outcomes and is becoming more common. Little is known about the safety of this "off-label" application of mistletoe. Methods. An observational study was performed within the Network Oncology. Treatment with intravenous mistletoe applications is described. The frequency of adverse drug reactions (ADRs) to intravenous mistletoe applications was calculated and compared to ADR data from a study on subcutaneous applications. Results. Of 475 cancer patients who received intravenous infusions of Helixor, Abnoba viscum, or Iscador mistletoe preparations, 22 patients (4.6%) reported 32 ADRs of mild (59.4%) or moderate severity (40.6%). No serious ADRs occurred. ADRs were more frequently reported to i.v. mistletoe administered alone (4.3%), versus prior to chemotherapy (1.6%). ADR frequency differed with respect to preparation type, with Iscador preparations showing a higher relative frequency, compared to Abnoba viscum and Helixor. Overall, patients were almost two times less likely to experience an ADR to intravenous compared to subcutaneous application of mistletoe. Conclusion. Intravenous mistletoe therapy was found to be safe and prospective studies for efficacy are recommended. PMID:24955100

  1. Safety of Intravenous Application of Mistletoe (Viscum album L.) Preparations in Oncology: An Observational Study

    PubMed Central

    Steele, Megan L.; Axtner, Jan; Happe, Antje; Kröz, Matthias; Matthes, Harald; Schad, Friedemann

    2014-01-01

    Background. Traditional mistletoe therapy in cancer patients involves subcutaneous applications of Viscum album L. preparations, with doses slowly increasing based on patient responses. Intravenous infusion of high doses may improve therapeutic outcomes and is becoming more common. Little is known about the safety of this “off-label” application of mistletoe. Methods. An observational study was performed within the Network Oncology. Treatment with intravenous mistletoe applications is described. The frequency of adverse drug reactions (ADRs) to intravenous mistletoe applications was calculated and compared to ADR data from a study on subcutaneous applications. Results. Of 475 cancer patients who received intravenous infusions of Helixor, Abnoba viscum, or Iscador mistletoe preparations, 22 patients (4.6%) reported 32 ADRs of mild (59.4%) or moderate severity (40.6%). No serious ADRs occurred. ADRs were more frequently reported to i.v. mistletoe administered alone (4.3%), versus prior to chemotherapy (1.6%). ADR frequency differed with respect to preparation type, with Iscador preparations showing a higher relative frequency, compared to Abnoba viscum and Helixor. Overall, patients were almost two times less likely to experience an ADR to intravenous compared to subcutaneous application of mistletoe. Conclusion. Intravenous mistletoe therapy was found to be safe and prospective studies for efficacy are recommended. PMID:24955100

  2. 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

  3. Observational study on Takotsubo-like cardiomyopathy: clinical features, diagnosis, prognosis and follow-up

    PubMed Central

    Cacciotti, Luca; Passaseo, Ilaria; Marazzi, Giuseppe; Camastra, Giovanni; Campolongo, Giuseppe; Beni, Sergio; Lupparelli, Fabrizio; Ansalone, Gerardo

    2012-01-01

    Objectives The present study attempts to identify appropriate elements that may contribute to clarify the broad clinical features (diagnosis, care, complication and prognosis) of Takotsubo-like cardiomyopathy for improving its management. Design study Observational study. Setting Primary level of care referred to the emergency department of Vannini Hospital, Rome, Italy. Participants The study population consisted of 75 patients, 72 of the them were women and 3 were men with a mean age of 71.9±9.6?years. Methods From February 2004 to November 2010, prospectively included 84 consecutive patients diagnosed for suspected Takotsubo-like cardiomyopathy. To be eligible, patients had to meet all the Mayo clinic criteria in the absence of neurological trauma or intracranial haemorrhage. Moreover, those patients that at follow-up still presented alteration of acute phase at ECG and echocardiogram were excluded. Thus, 75 patients comprised the study population. To follow-up 19 patients were lost. Results None of 75 patients died in acute phase. All patients were promptly discharged (8.4±4.4?days), since they recovered their normal functional status without symptoms. Follow-up information was available for 56 patients. At a mean follow-up time of 2.2±2?years (range, 0.1–6.8?years) two octogenarian patients (2.6%) died because of sudden cardiac death and pulmonary embolism, respectively. The Takotsubo-like cardiomyopathy recurred in one patient. Conclusions The results of this study support the previous reports about the good prognosis, also in critically ill patients, of Takotsubo-like cardiomyopathy. Further assessment will be needed to determine a careful and sustained follow-up for choosing the best care and foreseeing the recurrences of this emerging condition. PMID:23065445

  4. 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

  5. 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

  6. 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

  7. Experimental comparison of methods for estimation of the observed velocity of the vehicle in video stream

    NASA Astrophysics Data System (ADS)

    Konovalenko, Ivan; Kuznetsova, Elena

    2015-02-01

    In this paper, we consider the problem of object's velocity estimation via video stream by comparing three new methods of velocity estimation named as vertical edge algorithm, modified Lucas-Kanade method, and feature points algorithm. As an applied example the task of automatic evaluation of vehicles' velocity via video stream on toll roads is chosen. We took some videos from cameras mounted on the toll roads and marked them out to determine true velocity. Comparison is carried out of performance in the correct velocity detection of the proposed methods with each other. The relevance of this paper is practical implementation of these methods overcoming all the difficulties of realization.

  8. 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

  9. First Light Observations from the International Study of Astronomy Reasoning (ISTAR) Database

    NASA Astrophysics Data System (ADS)

    Tatge, Coty B.; Slater, Stephanie; Slater, Timothy F.; Bretones, Paulo S.; McKinnon, David; Schleigh, Sharon

    2016-01-01

    During the period between Fall 2014 and Summer 2015, the International Astronomical Union reorganized its structure to include the IAU Working Group on Theory and Methods in Astronomy Education. The initial goals of that working group are 1) promoting Astronomy Education Research (AER) by adopting the international collaboration model used by astronomy researchers, 2) fostering international astronomy education and AER capacity through the development of networks, training and shared resources, and 3) improving astronomy education by describing research based approaches to the teaching and learning of astronomy. In support of those efforts, the working group began a collaboration with the Center for Astronomy & Physics Education Research to develop the International Study of Astronomy Reasoning (ISTAR) Database, an online, searchable research tool, intended to catalog, characterize, and provide access to all known astronomy education research production, world-wide. Beginning in the Summer of 2015, a test of ISTAR's functionality began with a survey of a previously uncatalogued set of test objects: U.S.-based doctoral dissertations and masters. This target population was selected for its familiarity to the ISTAR developers, and for its small expected sample size (50-75 objects). First light observations indicated that the sample exceeded 300 dissertation objects. These objects were characterized across multiple variables, including: year of production, document source, type of resource, empirical methodology, context, informal setting type, research construct, type of research subject, scientific content, language, and nation of production. These initial observations provide motivation to extend this project to observe masters levels thesis, which are anticipated to be ten times more numerous as doctoral dissertations, other peer-reviewed contributions, contributions from the larger international community.

  10. Tweets about hospital quality: a mixed methods study

    PubMed Central

    Greaves, Felix; Laverty, Antony A; Cano, Daniel Ramirez; Moilanen, Karo; Pulman, Stephen; Darzi, Ara; Millett, Christopher

    2014-01-01

    Background Twitter is increasingly being used by patients to comment on their experience of healthcare. This may provide information for understanding the quality of healthcare providers and improving services. Objective To examine whether tweets sent to hospitals in the English National Health Service contain information about quality of care. To compare sentiment on Twitter about hospitals with established survey measures of patient experience and standardised mortality rates. Design A mixed methods study including a quantitative analysis of all 198?499 tweets sent to English hospitals over a year and a qualitative directed content analysis of 1000 random tweets. Twitter sentiment and conventional quality metrics were compared using Spearman's rank correlation coefficient. Key results 11% of tweets to hospitals contained information about care quality, with the most frequent topic being patient experience (8%). Comments on effectiveness or safety of care were present, but less common (3%). 77% of tweets about care quality were positive in tone. Other topics mentioned in tweets included messages of support to patients, fundraising activity, self-promotion and dissemination of health information. No associations were observed between Twitter sentiment and conventional quality metrics. Conclusions Only a small proportion of tweets directed at hospitals discuss quality of care and there was no clear relationship between Twitter sentiment and other measures of quality, potentially limiting Twitter as a medium for quality monitoring. However, tweets did contain information useful to target quality improvement activity. Recent enthusiasm by policy makers to use social media as a quality monitoring and improvement tool needs to be carefully considered and subjected to formal evaluation. PMID:24748372

  11. 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

  12. Improving patient safety during insertion of peripheral venous catheters: an observational intervention study

    PubMed Central

    Kampf, Günter; Reise, Gesche; James, Claudia; Gittelbauer, Kirsten; Gosch, Jutta; Alpers, Birgit

    2013-01-01

    Background: Peripheral venous catheters are frequently used in hospitalized patients but increase the risk of nosocomial bloodstream infection. Evidence-based guidelines describe specific steps that are known to reduce infection risk. However, the degree of guideline implementation in clinical practice is not known. The aim of this study was to determine the use of specific steps for insertion of peripheral venous catheters in clinical practice and to implement a multimodal intervention aimed at improving both compliance and the optimum order of the steps. Methods: The study was conducted at University Hospital Hamburg. An optimum procedure for inserting a peripheral venous catheter was defined based on three evidence-based guidelines (WHO, CDC, RKI) including five steps with 1A or 1B level of evidence: hand disinfection before patient contact, skin antisepsis of the puncture site, no palpation of treated puncture site, hand disinfection before aseptic procedure, and sterile dressing on the puncture site. A research nurse observed and recorded procedures for peripheral venous catheter insertion for healthcare workers in four different departments (endoscopy, central emergency admissions, pediatrics, and dermatology). A multimodal intervention with 5 elements was established (teaching session, dummy training, e-learning tool, tablet and poster, and direct feedback), followed by a second observation period. During the last observation week, participants evaluated the intervention. Results: In the control period, 207 insertions were observed, and 202 in the intervention period. Compliance improved significantly for four of five steps (e.g., from 11.6% to 57.9% for hand disinfection before patient contact; p<0.001, chi-square test). Compliance with skin antisepsis of the puncture site was high before and after intervention (99.5% before and 99.0% after). Performance of specific steps in the correct order also improved (e.g., from 7.7% to 68.6% when three of five steps were done; p<0.001). The intervention was described as helpful by 46.8% of the participants, as neutral by 46.8%, and as disruptive by 6.4%. Conclusions: A multimodal strategy to improve both compliance with safety steps for peripheral venous catheter insertion and performance of an optimum procedure was effective and was regarded helpful by healthcare workers. PMID:24327944

  13. Mixed method approaches in open-ended, qualitative, exploratory research involving people with intellectual disabilities: a comparative methods study.

    PubMed

    Ottmann, Goetz; Crosbie, Jenny

    2013-09-01

    People with intellectual disabilities and their families are increasingly being asked to provide input into the services they receive. Under the aegis of the United Nation Convention of the Rights of Persons with Disabilities, support plans crucially depend on a participant's articulation of his or her preferences and life goals. Yet, research highlighting the strengths and weaknesses of different methodological approaches has not been published. This study compared the results of a suite of qualitative methods (questionnaire, focus group, semi-structured interview, "case in point" ethnographic observation, photographic images, and carer proxy response) by identifying the advantages and disadvantages of each method employed. It also foregrounds an effective mix of methods that is likely to produce an adequate representation of the views of people with disabilities within the context of open-ended exploratory questions. PMID:23801355

  14. 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.

  15. Van Allen Probes observations of unusually low frequency whistler mode waves observed in association with moderate magnetic storms: Statistical study

    NASA Astrophysics Data System (ADS)

    Cattell, C. A.; Breneman, A. W.; Thaller, S. A.; Wygant, J. R.; Kletzing, C. A.; Kurth, W. S.

    2015-09-01

    We show the first evidence for locally excited chorus at frequencies below 0.1 fce (electron cyclotron frequency) in the outer radiation belt. A statistical study of chorus during geomagnetic storms observed by the Van Allen Probes found that frequencies are often dramatically lower than expected. The frequency at peak power suddenly stops tracking the equatorial 0.5 fce and f/fce decreases rapidly, often to frequencies well below 0.1 fce (in situ and mapped to equator). These very low frequency waves are observed both when the satellites are close to the equatorial plane and at higher magnetic latitudes. Poynting flux is consistent with generation at the equator. Wave amplitudes can be up to 20 to 40 mV/m and 2 to 4 nT. We conclude that conditions during moderate to large storms can excite unusually low frequency chorus, which is resonant with more energetic electrons than typical chorus, with critical implications for understanding radiation belt evolution.

  16. Homotopy analysis method to study a quadrupole mass filter.

    PubMed

    Seddighi Chaharborj, S; Seddighi Chahrborj, S; Sadat Kiai, S M; Abu Bakar, M R; Ziaeian, I; Gheisari, Y

    2012-04-01

    The homotopy analysis method (HAM) is applied to study the behavior of a hyperbolic rods of quadrupole mass filter and a sinusoidal potential form V(ac) ?cos(?t). Numerical computation method of a 20th-order HAM is employed to compare the physical properties of the confined ions with fifth-order Runge-Kutta method. Also, comparison is made for the first stability region, the ion trajectories in real time, the polar plots, and the ion trajectory in x?-?y plan. The results show that the two methods are fairly similar; therefore, the HAM method has potential application to solve linear and nonlinear equations of the charge particle confinement in quadrupole field. PMID:22689625

  17. Studies on Sweet Potato Production Methods in Texas. 

    E-print Network

    Wright, R. E.

    1945-01-01

    of Horticulture [Blank Page in Original Bulletin] Successful sweet. potato pro,duction is largely the result of care in following methods known to give god results. These incIude the selection of roots to secure potentially productive seed of high quality... ................................................. Acknowledgment -14 I .............................................. Selected References -15 STUDIES ON SWEET POTATO PRODUCTOX METHODS IN TEXAS By R. E. Wright, Horticulturist* *In Charge of Sweet Potato Investigations Laboratory. Gilmer, Texas. Acreage...

  18. 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

  19. An observational study on cough in children: epidemiology, impact on quality of sleep and treatment outcome

    PubMed Central

    2012-01-01

    Background Cough is one of the most frequent symptoms in children and is the most common symptom for which children visit a health care provider. Methods This is an observational study on acute cough associated with upper respiratory tract infection (URTI) in children. The study evaluates the epidemiology and impact of cough on quality of sleep and children's activities, and the outcome of cough with antitussive treatments in pediatric routine clinical practice. Study assessments were performed through a pediatric cough questionnaire (PCQ), developed by the Italian Society of Cough Study. A total of 433 children visited by family care pediatricians for acute cough due to a URTI were enrolled in this study, with mean age of 6.1 years (SD 3.6). Cough type, duration, severity and frequency, cough impact on sleep disturbances of children and parents and on school and sport activities were assessed at baseline. In a subset of 241 children who were either treated with antitussive drugs (levodropropizine n = 101, central antitussives n = 60) or received no treatment (n = 80), the outcome of cough after 6 days was analyzed in terms of resolution, improvement, no change, or worsening. Descriptive analysis, ?2 test, and multivariate analysis with stepwise logistic regression were performed. Results Cough disturbed sleep in 88% of children and 72% of parents. In children treated with cough suppressants, the duration, type, intensity, and frequency cough were similar at baseline in the two groups respectively treated with levodropropizine and central antitussives (cloperastine and codeine). Both levodropropizine and central drugs reduced cough intensity and frequency. However, percentage of cough resolution was higher with levodropropizine than with central antitussives (47% vs. 28% respectively, p = 0.0012). Conclusions Acute cough disturbs sleep in most children and their parents. Both levodropropizine and central antitussives reduced cough intensity, with levodropropizine producing a higher cough resolution rate. PMID:22269875

  20. Learning from positively deviant wards to improve patient safety: an observational study protocol

    PubMed Central

    Baxter, Ruth; Taylor, Natalie; Kellar, Ian; Lawton, Rebecca

    2015-01-01

    Introduction Positive deviance is an asset-based approach to improvement which has recently been adopted to improve quality and safety within healthcare. The approach assumes that solutions to problems already exist within communities. Certain groups or individuals identify these solutions and succeed despite having the same resources as others. Within healthcare, positive deviance has previously been applied at individual or organisational levels to improve specific clinical outcomes or processes of care. This study explores whether the positive deviance approach can be applied to multidisciplinary ward teams to address the broad issue of patient safety among elderly patients. Methods and analysis Preliminary work analysed National Health Service (NHS) Safety Thermometer data from 34 elderly medical wards to identify 5 ‘positively deviant’ and 5 matched ‘comparison’ wards. Researchers are blinded to ward status. This protocol describes a multimethod, observational study which will (1) assess the concurrent validity of identifying positively deviant elderly medical wards using NHS Safety Thermometer data and (2) generate hypotheses about how positively deviant wards succeed. Patient and staff perceptions of safety will be assessed on each ward using validated surveys. Correlation and ranking analyses will explore whether this survey data aligns with the routinely collected NHS Safety Thermometer data. Staff focus groups and researcher fieldwork diaries will be completed and qualitative thematic content analysis will be used to generate hypotheses about the strategies, behaviours, team cultures and dynamics that facilitate the delivery of safe patient care. The acceptability and sustainability of strategies identified will also be explored. Ethics and dissemination The South East Scotland Research Ethics Committee 01 approved this study (reference: 14/SS/1085) and NHS Permissions were granted from all trusts. Findings will be published in peer-reviewed, scientific journals, and presented at academic conferences. Trial registration number This study is registered on the UK Clinical Research Network Study Portfolio (reference number—18050). PMID:26656985

  1. 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

  2. Raman spectra of biological samples: A study of preprocessing methods.

    PubMed

    Afseth, Nils Kristian; Segtnan, Vegard Herman; Wold, Jens Petter

    2006-12-01

    In this study preprocessing of Raman spectra of different biological samples has been studied, and their effect on the ability to extract robust and quantitative information has been evaluated. Four data sets of Raman spectra were chosen in order to cover different aspects of biological Raman spectra, and the samples constituted salmon oils, juice samples, salmon meat, and mixtures of fat, protein, and water. A range of frequently used preprocessing methods, as well as combinations of different methods, was evaluated. Different aspects of regression results obtained from partial least squares regression (PLSR) were used as indicators for comparing the effect of different preprocessing methods. The results, as expected, suggest that baseline correction methods should be performed in advance of normalization methods. By performing total intensity normalization after adequate baseline correction, robust calibration models were obtained for all data sets. Combination methods like standard normal variate (SNV), multiplicative signal correction (MSC), and extended multiplicative signal correction (EMSC) in their basic form were not able to handle the baseline features present in several of the data sets, and these methods thus provide no additional benefits compared to the approach of baseline correction in advance of total intensity normalization. EMSC provides additional possibilities that require further investigation. PMID:17217584

  3. Evolving epidemiology and antimicrobial resistance in spontaneous bacterial peritonitis: a two-year observational study

    PubMed Central

    2014-01-01

    Background Current recommendations for empirical antimicrobial therapy in spontaneous bacterial peritonitis (SBP) are based on quite old trials. Since microbial epidemiology and the management of patients have changed, whether these recommendations are still appropriate must be confirmed. Methods An observational study that exhaustively collected the clinical and biological data associated with positive ascitic fluid cultures was conducted in four French university hospitals in 2010–2011. Results Two hundred and sixty-eight documented positive cultures were observed in 190 cirrhotic patients (median age 61.5 years, 58.5% Child score C). Of these, 57 were classified as confirmed SBP and 140 as confirmed bacterascites. The predominant flora was Gram-positive cocci, whatever the situation (SBP, bacterascites, nosocomial/health-care related or not). Enteroccocci (27.7% E. faecium) were isolated in 24% of the episodes, and in 48% from patients receiving quinolone prophylaxis. E. coli were susceptible to amoxicillin-clavulanate and to third-generation cephalosporins in 62.5% and 89.5% of cases, respectively. No single antibiotic allowed antimicrobial coverage of more than 60%. Only combinations such as amoxicillin?+?third-generation cephalosporin or cotrimoxazole allowed coverage close to 75-80% in non-nosocomial episodes. Combinations based on broader spectrum antibiotics should be considered for empirical therapy of nosocomial infections. Conclusions Our study confirmed the changing spectrum of pathogens in SBP and bacterascites, and the need for more complex antibiotic strategies than those previously recommended. Our findings also underline the need for new clinical trials conducted in the current epidemiological context. PMID:24884471

  4. The practice of intensive care nurses using the closed suctioning system: An observational study

    PubMed Central

    Haghighat, Somayeh; Yazdannik, AhmadReza

    2015-01-01

    Background: Endotracheal suctioning (ETS) is an essential procedure performed for mechanically ventilated patients. ETS can be either performed by open or closed suctioning system (CSS). There may be some concern on how closed-system ETS is practiced by intensive care nurses. This study was designed to investigate closed-system ETS practices of critical care nurses and to compare their practice with standard recommendations. Materials and Methods: A prospective observational study was conducted during August and December 2012 to establish how critical care nurses (N = 40) perform different steps in a typical ETS practice and to compare it with the current best practice recommendations through a 23-item structured checklist. The results were categorized into three sections: Pre-suctioning, suctioning, and post-suctioning practices. Results: Pre-suctioning, suctioning, and post-suctioning practices mean scores were 7.5, 11.75, and 8.5, respectively, out of 16, 16, and 12, respectively. The total suctioning practice score was 27.75 out of 44. Most discrepancies were observed in the patients’ assessment and preparation, infection control practices, and use of an appropriate catheter. Spearman correlation coefficient indicated a significant statistical positive correlation between suctioning education period and suctioning practice score (P < 0.0001) and between working experience and suctioning practice score (P = 0.02). Conclusions: The findings revealed that critical care nurses do not fully adhere to the best practice recommendation in CSS. We recommend that standard guidelines on ETS practice be included in the current education of critical care nurses. PMID:26457102

  5. 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…

  6. Fingolimod Treatment in Relapsing-Remitting Multiple Sclerosis Patients: A Prospective Observational Multicenter Postmarketing Study

    PubMed Central

    Totaro, Rocco; Di Carmine, Caterina; Costantino, Gianfranco; Fantozzi, Roberta; Bellantonio, Paolo; Fuiani, Aurora; Mundi, Ciro; Ruggieri, Stefano; Marini, Carmine; Carolei, Antonio

    2015-01-01

    Objective. The aim of this prospective observational multicenter postmarketing study was to evaluate fingolimod efficacy in a real world clinical setting. Methods. One hundred forty-two subjects with relapsing-remitting multiple sclerosis (RRMS) were enrolled in three multiple sclerosis centers throughout Central and Southern Italy between January 2011 and September 2013. After enrollment, regular visits and EDSS assessment were scheduled every 3 months, and MRI scan was obtained every 12 months. Patients were followed up from 1 to 33 months (mean 14.95 ± 9.15 months). The main efficacy endpoints included the proportion of patients free from clinical relapses, from disability progression, from magnetic resonance imaging activity, and from any disease activity. Results. Out of 142 patients enrolled in the study, 88.1% were free from clinical relapse and 69.0% were free from disability progression; 68.5% of patients remained free from new or newly enlarging T2 lesions and 81.7% of patients were free from gadolinium enhancing lesions. Overall the proportion of patients free from any disease activity was 41.9%. Conclusions. Our data in a real world cohort are consistent with previous findings that yield convincing evidence for the efficacy of fingolimod in patients with RRMS. PMID:26266049

  7. Genome-wide association study of survival from sepsis due to pneumonia: an observational cohort study

    PubMed Central

    Rautanen, Anna; Mills, Tara C; Gordon, Anthony C; Hutton, Paula; Steffens, Michael; Nuamah, Rosamond; Chiche, Jean-Daniel; Parks, Tom; Chapman, Stephen J; Davenport, Emma E; Elliott, Katherine S; Bion, Julian; Lichtner, Peter; Meitinger, Thomas; Wienker, Thomas F; Caulfield, Mark J; Mein, Charles; Bloos, Frank; Bobek, Ilona; Cotogni, Paolo; Sramek, Vladimir; Sarapuu, Silver; Kobilay, Makbule; Ranieri, V Marco; Rello, Jordi; Sirgo, Gonzalo; Weiss, Yoram G; Russwurm, Stefan; Schneider, E Marion; Reinhart, Konrad; Holloway, Paul A H; Knight, Julian C; Garrard, Chris S; Russell, James A; Walley, Keith R; Stüber, Frank; Hill, Adrian V S; Hinds, Charles J

    2015-01-01

    Summary Background Sepsis continues to be a major cause of death, disability, and health-care expenditure worldwide. Despite evidence suggesting that host genetics can influence sepsis outcomes, no specific loci have yet been convincingly replicated. The aim of this study was to identify genetic variants that influence sepsis survival. Methods We did a genome-wide association study in three independent cohorts of white adult patients admitted to intensive care units with sepsis, severe sepsis, or septic shock (as defined by the International Consensus Criteria) due to pneumonia or intra-abdominal infection (cohorts 1–3, n=2534 patients). The primary outcome was 28 day survival. Results for the cohort of patients with sepsis due to pneumonia were combined in a meta-analysis of 1553 patients from all three cohorts, of whom 359 died within 28 days of admission to the intensive-care unit. The most significantly associated single nucleotide polymorphisms (SNPs) were genotyped in a further 538 white patients with sepsis due to pneumonia (cohort 4), of whom 106 died. Findings In the genome-wide meta-analysis of three independent pneumonia cohorts (cohorts 1–3), common variants in the FER gene were strongly associated with survival (p=9·7?×?10?8). Further genotyping of the top associated SNP (rs4957796) in the additional cohort (cohort 4) resulted in a combined p value of 5·6?×?10?8 (odds ratio 0·56, 95% CI 0·45–0·69). In a time-to-event analysis, each allele reduced the mortality over 28 days by 44% (hazard ratio for death 0·56, 95% CI 0·45–0·69; likelihood ratio test p=3·4 × 10?9, after adjustment for age and stratification by cohort). Mortality was 9·5% in patients carrying the CC genotype, 15·2% in those carrying the TC genotype, and 25·3% in those carrying the TT genotype. No significant genetic associations were identified when patients with sepsis due to pneumonia and intra-abdominal infection were combined. Interpretation We have identified common variants in the FER gene that associate with a reduced risk of death from sepsis due to pneumonia. The FER gene and associated molecular pathways are potential novel targets for therapy or prevention and candidates for the development of biomarkers for risk stratification. Funding European Commission and the Wellcome Trust. PMID:25533491

  8. Iron Supplementation and Mortality in Incident Dialysis Patients: An Observational Study

    PubMed Central

    Kronenberg, Florian; Neyer, Ulrich; Knoll, Florian; Lhotta, Karl; Weiss, Günter

    2014-01-01

    Background Studies on the association between iron supplementation and mortality in dialysis patients are rare and conflicting. Methods In our observational single-center cohort study (INVOR study) we prospectively studied 235 incident dialysis patients. Time-dependent Cox proportional hazards models using all measured laboratory values for up to 7.6 years were applied to study the association between iron supplementation and all-cause mortality, cardiovascular and sepsis-related mortality. Furthermore, the time-dependent association of ferritin levels with mortality in patients with normal C-reactive protein (CRP) levels (<0.5 mg/dL) and elevated CRP levels (?0.5 mg/dL) was evaluated by using non-linear P-splines to allow flexible modeling of the association. Results One hundred and ninety-one (81.3%) patients received intravenous iron, 13 (5.5%) patients oral iron, whereas 31 (13.2%) patients were never supplemented with iron throughout the observation period. Eighty-two (35%) patients died during a median follow-up of 34 months, 38 patients due to cardiovascular events and 21 patients from sepsis. Baseline CRP levels were not different between patients with and without iron supplementation. However, baseline serum ferritin levels were lower in patients receiving iron during follow up (median 93 vs 251 ng/mL, p<0.001). Iron supplementation was associated with a significantly reduced all-cause mortality [HR (95%CI): 0.22 (0.08–0.58); p?=?0.002] and a reduced cardiovascular and sepsis-related mortality [HR (95%CI): 0.31 (0.09–1.04); p?=?0.06]. Increasing ferritin concentrations in patients with normal CRP were associated with a decreasing mortality, whereas in patients with elevated CRP values ferritin levels>800 ng/mL were linked with increased mortality. Conclusions Iron supplementation is associated with reduced all-cause mortality in incident dialysis patients. While serum ferritin levels up to 800 ng/mL appear to be safe, higher ferritin levels are associated with increased mortality in the setting of concomitant inflammation. PMID:25462819

  9. 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

  10. A study of black aurora from aircraft-based optical observations and plasma measurements on FAST

    E-print Network

    Bonnell, John W.

    A study of black aurora from aircraft-based optical observations and plasma measurements on FAST L 2002. [1] Black aurora was observed on 30 January 1998 in a narrow-field camera forty seconds before. Electron energy flux measured by FAST provided strong evidence that FAST passed over black aurora

  11. Combining Propensity Score Matching and Group-Based Trajectory Analysis in an Observational Study

    ERIC Educational Resources Information Center

    Haviland, Amelia; Nagin, Daniel S.; Rosenbaum, Paul R.

    2007-01-01

    In a nonrandomized or observational study, propensity scores may be used to balance observed covariates and trajectory groups may be used to control baseline or pretreatment measures of outcome. The trajectory groups also aid in characterizing classes of subjects for whom no good matches are available and to define substantively interesting groups…

  12. Methods to Collect, Compile, and Analyze Observed Short-lived Fission Product Gamma Data

    SciTech Connect

    Finn, Erin C.; Metz, Lori A.; Payne, Rosara F.; Friese, Judah I.; Greenwood, Lawrence R.; Kephart, Jeremy D.; Pierson, Bruce D.; Ellis, Tere A.

    2011-09-29

    A unique set of fission product gamma spectra was collected at short times (4 minutes to 1 week) on various fissionable materials. Gamma spectra were collected from the neutron-induced fission of uranium, neptunium, and plutonium isotopes at thermal, epithermal, fission spectrum, and 14-MeV neutron energies. This report describes the experimental methods used to produce and collect the gamma data, defines the experimental parameters for each method, and demonstrates the consistency of the measurements.

  13. A method for correcting aspect solution errors in ROSAT HRI observations of compact sources

    NASA Technical Reports Server (NTRS)

    Morse, Jon A.

    1994-01-01

    X-ray point sources observed with the ROSAT High Resolution Imager (HRI) often appear elongated over scales of approximately 5 sec-10 sec from the image core. This elongation has been attributed to errors in the attitude correction as the satellite is wobbled during the observations, and affects sources with both soft and hard X-ray spectra. In this paper, I report the results of an attempt to rid a high signal-to-noise observation of the soft X-ray point source HZ 43 of its characteristic elongation. I divided the observation into 181 separate images, each containing photons from only a small region on the detector through which the source passed during the satellite's wobble. By measuring the positions of the individual image centroids, I found clear evidence for systematic offsets from a common mean by up to approximately +/- 3 sec in both right ascension and declination as a function of phase in the satellite wobble. Shifting the subimages to a common center and then restacking them into a single image measurably improved the symmetry of the point-spread function. HRI observations are wobbled primarily to smooth out variations in the pixel-to-pixel sensitivity of the detector and also to extend the lifetime of the microchannel plates in the detector since these decay at a given location as a function of the number of photons detected. However, the elongations introduced by the aspect errors inhibit the identification of possible extended X-ray emission associated with sources such as pulsars and active galactic nuclei. In light of these results, I suggest that until the aspect errors are understood, observations of compact sources, where this effect may be important, should not be wobbled.

  14. 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.

    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.

  15. 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.

  16. Recruitment of Hispanics into an observational study of chronic kidney disease: the Hispanic Chronic Renal Insufficiency Cohort Study experience.

    PubMed

    Lora, Claudia M; Ricardo, Ana C; Brecklin, Carolyn S; Fischer, Michael J; Rosman, Robert T; Carmona, Eunice; Lopez, Amada; Balaram, Manjunath; Nessel, Lisa; Tao, Kaixiang Kelvin; Xie, Dawei; Kusek, John W; Go, Alan S; Lash, James P

    2012-11-01

    Despite the large burden of chronic kidney disease (CKD) in Hispanics, this population has been underrepresented in research studies. We describe the recruitment strategies employed by the Hispanic Chronic Renal Insufficiency Cohort Study, which led to the successful enrollment of a large population of Hispanic adults with CKD into a prospective observational cohort study. Recruitment efforts by bilingual staff focused on community clinics with Hispanic providers in high-density Hispanic neighborhoods in Chicago, academic medical centers, and private nephrology practices. Methods of publicizing the study included church meetings, local Hispanic print media, Spanish television and radio stations, and local health fairs. From October 2005 to July 2008, we recruited 327 Hispanics aged 21-74 years with mild-to-moderate CKD as determined by age-specific estimated glomerular filtration rate (eGFR). Of 716 individuals completing a screening visit, 49% did not meet eGFR inclusion criteria and 46% completed a baseline visit. The mean age at enrollment was 57.1 and 67.1% of participants were male. Approximately 75% of enrolled individuals were Mexican American, 15% Puerto Rican, and 10% had other Latin American ancestry. Eighty two percent of participants were Spanish-speakers. Community-based and academic primary care clinics yielded the highest percentage of participants screened (45.9% and 22.4%) and enrolled (38.2% and 24.5%). However, academic and community-based specialty clinics achieved the highest enrollment yield from individuals screened (61.9% to 71.4%). A strategy focused on primary care and nephrology clinics and the use of bilingual recruiters allowed us to overcome barriers to the recruitment of Hispanics with CKD. PMID:22841929

  17. Recruitment of Hispanics into an Observational Study of Chronic Kidney Disease:The Hispanic Chronic Renal Insufficiency Cohort Study Experience

    PubMed Central

    Lora, Claudia M.; Ricardo, Ana C.; Brecklin, Carolyn S.; Fischer, Michael J.; Rosman, Robert T.; Carmona, Eunice; Lopez, Amada; Balaram, Manjunath; Nessel, Lisa; Tao, Kelvin; Xie, Dawei; Kusek, John W.; Go, Alan S.; Lash, James P.

    2012-01-01

    Despite the large burden of chronic kidney disease (CKD) in Hispanics, this population has been underrepresented in research studies. We describe the recruitment strategies employed by the Hispanic Chronic Renal Insufficiency Cohort Study, which led to the successful enrollment of a large population of Hispanic adults with CKD into a prospective observational cohort study. Recruitment efforts by bilingual staff focused on community clinics with Hispanic providers in high-density Hispanic neighborhoods in Chicago, academic medical centers, and private nephrology practices. Methods of publicizing the study included church meetings, local Hispanic print media, Spanish television and radio stations, and local health fairs. From October 2005 to July 2008, we recruited 327 Hispanics aged 21–74 years with mild-to-moderate CKD as determined by age-specific estimated glomerular filtration rate (eGFR). Of 716 individuals completing a screening visit, 49% did not meet eGFR inclusion criteria and 46% completed a baseline visit. The mean age at enrollment was 57.1 and 67.1% of participants were male. Approximately 75% of enrolled individuals were Mexican American, 15% Puerto Rican, and 10% had other Latin American ancestry. Eighty two percent of participants were Spanish-speakers. Community-based and academic primary care clinics yielded the highest percentage of participants screened (45.9% and 22.4%) and enrolled (38.2% and 24.5%). However, academic and community-based specialty clinics achieved the highest enrollment yield from individuals screened (61.9% to 71.4%). A strategy focused on primary care and nephrology clinics and the use of bilingual recruiters allowed us to overcome barriers to the recruitment of Hispanics with CKD. PMID:22841929

  18. Rethinking the Evaluation of Algorithm Animations as Learning Aids: An Observational Study

    E-print Network

    Stasko, John T.

    Rethinking the Evaluation of Algorithm Animations as Learning Aids: An Observational Study Colleen,stasko,ataylor@cc.gatech.edu Technical Report GIT-GVU-99-10 March 1999 Abstract A number of prior studies have found that using animation instruction. This article reports on a study in which animation is utilized in more of a homework" learning

  19. Effectiveness of Compounded Bioidentical Hormone Replacement Therapy: An Observational Cohort Study

    PubMed Central

    2011-01-01

    Background Bioidentical Hormone Replacement Therapy (BHRT) is believed it to be a safer and equally effective alternative to Conventional Hormone Therapy for the relief of menopausal symptoms; however, data are needed to support these claims. The objective of this study is to evaluate the effectiveness of compounded BHRT provided in six community pharmacies. Methods This was an observational cohort study of women between the ages of 18-89 who received a compounded BHRT product from January 1, 2003 to April 30, 2010 in six community pharmacies. Data included patient demographics, comorbidities, therapeutic outcomes, and hormone therapies. Women self-rated menopausal symptoms as absent, mild, moderate, or severe. Descriptive statistics were used to characterize the patient population, BHRT use, and adverse events. Patient symptom severity was compared at baseline and 3 to 6 months follow-up using the Wilcoxon signed-rank test. Results Women (n = 296) receiving BHRT at Oakdell Pharmacy had a mean (standard deviation) age of 52 (9) years. The most common BHRT dosage forms utilized were topical (71%) and oral (43%). Compounded BHRT regimens were generally initiated at low doses regardless of route. Women experienced a 25% decrease in emotional lability (p < 0.01), a 25% decrease in irritability (p < 0.01), and a 22% reduction in anxiety (p = 0.01) within 3 to 6 months. These women also experienced a 14% reduction in night sweats (p = 0.09) and a 6% reduction in hot flashes (p = 0.50). Conclusions This study demonstrates that compounded BHRT improves mood symptoms. Larger studies are needed to examine the impact on vasomotor symptoms, myocardial infarction and breast cancer. PMID:21651797

  20. Accessing Suicide-Related Information on the Internet: A Retrospective Observational Study of Search Behavior

    PubMed Central

    2013-01-01

    Background The Internet’s potential impact on suicide is of major public health interest as easy online access to pro-suicide information or specific suicide methods may increase suicide risk among vulnerable Internet users. Little is known, however, about users’ actual searching and browsing behaviors of online suicide-related information. Objective To investigate what webpages people actually clicked on after searching with suicide-related queries on a search engine and to examine what queries people used to get access to pro-suicide websites. Methods A retrospective observational study was done. We used a web search dataset released by America Online (AOL). The dataset was randomly sampled from all AOL subscribers’ web queries between March and May 2006 and generated by 657,000 service subscribers. Results We found 5526 search queries (0.026%, 5526/21,000,000) that included the keyword "suicide". The 5526 search queries included 1586 different search terms and were generated by 1625 unique subscribers (0.25%, 1625/657,000). Of these queries, 61.38% (3392/5526) were followed by users clicking on a search result. Of these 3392 queries, 1344 (39.62%) webpages were clicked on by 930 unique users but only 1314 of those webpages were accessible during the study period. Each clicked-through webpage was classified into 11 categories. The categories of the most visited webpages were: entertainment (30.13%; 396/1314), scientific information (18.31%; 240/1314), and community resources (14.53%; 191/1314). Among the 1314 accessed webpages, we could identify only two pro-suicide websites. We found that the search terms used to access these sites included “commiting suicide with a gas oven”, “hairless goat”, “pictures of murder by strangulation”, and “photo of a severe burn”. A limitation of our study is that the database may be dated and confined to mainly English webpages. Conclusions Searching or browsing suicide-related or pro-suicide webpages was uncommon, although a small group of users did access websites that contain detailed suicide method information. PMID:23305632

  1. Study of State Diagnosis Method of Gas-insulated Switchgear

    NASA Astrophysics Data System (ADS)

    Shinkai, Hiroyuki; Goshima, Hisashi; Yashima, Masafumi

    The maintenance rationalization to the equipment under operation and the lifetime protraction based on appropriate diagnosis result are necessary for the reduction in cost of gas insulated equipment. Therefore, the accurate state observation method for inside of equipment is requested. In this research, the new state observation method which enabled the high sensitivity detection of decomposition gas by setting up the absorbent outside of the equipment was proposed. As the result, it was shown without ruining the reliability of the equipment by the absorbent unit setting up outside of the gas insulation equipment that the high sensitivity detection of decomposition gas is possible. Because the concentration of decomposition gas shows a remarkable correlation between total electric charge of partial discharge and the lifetime is different depending on the kind of the decomposition gas, the possibility that the detailed state of the equipment can be diagnosed was shown according to the detected gaseous species and its amount. Moreover, we succeeded in the detection of the decomposition gas from the absorbent, therefore the availability of this method was shown.

  2. Model accuracy impact through rescaled observations in hydrological data assimilation studies

    NASA Astrophysics Data System (ADS)

    Tugrul Yilmaz, M.; Crow, Wade T.; Ryu, Dongryeol

    2015-04-01

    Relative magnitudes of signal and noise in soil moisture datasets (e.g. satellite-, model-, station-based) feature significant variability. Optimality of the analysis when assimilating observations into the model depends on the degree that the differences between the signal variances of model and observations are minimized. Rescaling techniques that aim to reduce such differences in general only focus on matching certain statistics of the model and the observations while the impact of their relative accuracy over the optimality of the analysis remains unexplored. In this study the impacts of the relative accuracies of seasonality and anomaly components of modeled and observation-based soil moisture time series on optimality of assimilation analysis is investigated. Experiments using well-controlled synthetic and real datasets are performed. Experiments are performed by rescaling observations to model with varying aggressiveness: i) rescaling the entire observation time-series as one-piece or each month separately; ii) rescaling observation seasonality and anomaly components separately; iii) inserting model seasonality directly into observations while anomaly components are only rescaled. A simple Antecedent Precipitation Index (API) model is selected in both synthetic and real dataset experiments. Observations are assimilated into the API model using Kalman filter. Real dataset experiments use the Land Parameter Retrieval Model (LPRM) product based on the Advanced Microwave Scanning Radiometer on the Aqua platform (AMSR-E) observations over four USDA-ARS watersheds, while ground-based observations collected over these watersheds are used for validation. Results show that it is favorable to rescale observations more aggressively to a model when the model is more accurate (higher signal to noise ratio than the observations), while rescaling the observations strongly to the model degrades the analysis if the observations are more skillful.

  3. Observational and evolutionary studies of neutron star X-ray binaries

    E-print Network

    Lin, Jinrong, Ph. D. Massachusetts Institute of Technology

    2011-01-01

    In this thesis, we present our observational and evolutionary studies of neutron stars in X-ray binary systems. A variety of topics are discussed, which are all related by a single scientific theme, namely, helping to set ...

  4. 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...

  5. A novel method for state of charge estimation of lithium-ion batteries using a nonlinear observer

    NASA Astrophysics Data System (ADS)

    Xia, Bizhong; Chen, Chaoren; Tian, Yong; Sun, Wei; Xu, Zhihui; Zheng, Weiwei

    2014-12-01

    The state of charge (SOC) is important for the safety and reliability of battery operation since it indicates the remaining capacity of a battery. However, as the internal state of each cell cannot be directly measured, the value of the SOC has to be estimated. In this paper, a novel method for SOC estimation in electric vehicles (EVs) using a nonlinear observer (NLO) is presented. One advantage of this method is that it does not need complicated matrix operations, so the computation cost can be reduced. As a key step in design of the nonlinear observer, the state-space equations based on the equivalent circuit model are derived. The Lyapunov stability theory is employed to prove the convergence of the nonlinear observer. Four experiments are carried out to evaluate the performance of the presented method. The results show that the SOC estimation error converges to 3% within 130 s while the initial SOC error reaches 20%, and does not exceed 4.5% while the measurement suffers both 2.5% voltage noise and 5% current noise. Besides, the presented method has advantages over the extended Kalman filter (EKF) and sliding mode observer (SMO) algorithms in terms of computation cost, estimation accuracy and convergence rate.

  6. 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.

  7. Improved methods for the study of hadronic physics from lattice QCD

    SciTech Connect

    Orginos, Kostas; Richards, David

    2015-02-05

    The solution of QCD on a lattice provides a first-principles method for understanding QCD in the low-energy regime, and is thus an essential tool for nuclear physics. The generation of gauge configurations, the starting point for lattice calculations, requires the most powerful leadership-class computers available. However, to fully exploit such leadership-class computing requires increasingly sophisticated methods for obtaining physics observables from the underlying gauge ensembles. In this study, we describe a variety of recent methods that have been used to advance our understanding of the spectrum and structure of hadrons through lattice QCD.

  8. [Colony blot method for detection of legionellas--results of a comparative study].

    PubMed

    Obst, U

    1996-11-01

    In the following short communication a new commercially available immunoassay for the quantitative detection of Legionellae after cultivation was compared with the conventional method recommended by ISO in a study shared by 6 laboratories. After a training phase of the laboratory personal a very good agreement of immunological and conventional method was observed by testing 310 water samples. The colony blot assay for quantitative identification of Legionella spec. is a rapid and specific method and can be recommended for quantification of Legionella spec. in water samples. PMID:9409910

  9. 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.

  10. Identity method to study chemical fluctuations in relativistic heavy-ion collisions

    SciTech Connect

    Gazdzicki, Marek; Grebieszkow, Katarzyna; Mackowiak, Maja; Mrowczynski, Stanislaw

    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.

  11. A study of Mediterranean Eddies by in situ and remote sensing methods

    NASA Astrophysics Data System (ADS)

    Ienna, Federico Salvatore

    Subsurface coherent vortices in the North Atlantic, whose saline water originates from the Mediterranean Sea and which are known as Mediterranean Eddies ("meddies"), have been of particular interest to physical oceanographers since their discovery, especially for their salt and heat transport properties into the North Atlantic Ocean. Many studies in the past have been successful in observing and studying the typical properties of meddies by probing them with in-situ techniques. The use of remote sensing techniques would offer a much cheaper and easier alternative for studying these phenomena, but only a few past studies have been able to study meddies by remote sensing, and a reliable method for observing them remotely remains elusive. This research presents a new way of locating and tracking meddies in the North Atlantic Ocean using satellite altimeter data. The method presented in this research makes use of Ensemble Empirical Mode Decomposition (EEMD) as a mean to isolate the surface expressions of meddies on the ocean surface and separate them from any other surface constituents, allowing robust meddies to be consistently tracked by satellite. One such meddy is successfully tracked over a 6 month time period (2 November 2005 - 17 May 2006). Results of the satellite tracking method are verified using Expendable Bathythermographs (XBT). Furthermore, three other meddies are also studied by in-situ observations using Argo float data, and an analysis of the buoyancy frequency properties of meddies is made.

  12. A Global Analysis of the ZWD/PW Conversion Methods using Radiosonde Observations and Numerical Weather Models

    NASA Astrophysics Data System (ADS)

    Rozsa, S.

    2014-12-01

    Water vapor plays an important role as a basic climate variable in the thermodynamics and dynamics of the storm systems at the atmosphere and in hydrological cycles of local, regional and global scales. Moreover, the distribution of atmospheric water vapor is difficult to determine because of its rapid change in spatial and temporal scales. Atmospheric water vapor can be estimated by the zenith delay derived from ground-based GNSS data. Ground-based GNSS receivers are a valuable source for determining total zenith delay (ZTD) and precipitable water vapor (PW) data for meteorology since they are portable, economic and provide measurements that are not affected by weather conditions. They cannot provide a humidity profile as radiosondes can, however they have the advantage of producing automated continuous data as opposed to operational radiosondes usually providing two measurements in a day. Therefore, tropospheric delay modeling methods for estimating precipitable water vapor using GNSS signals are being developed frequently. Wet and hydrostatic zenith delays can be computed by applying the mapping functions which are mathematical equations using elevation angles. The observed tropospheric delays can be used for monitoring the water vapor content of the troposphere. In several regions of the world GNSS derived products are already used on a routine basis for numerical weather prediction. In this study, PW values obtained from radiosonde profiles and the ones derived from ground-based GNSS data are processed both with BERNESE v5.0 using Niell mapping function and GAMIT/GLOBK using empirical model GPT (Global Pressure and Temperature) are compared with the values computed from radiosonde analysis algorithm under severe storm conditions. In order to convert the ZWD to PW new, locally fitted models are derived using local radiosonde observations and ECMWF model data.

  13. REVIEW: Development of methods for body composition studies

    NASA Astrophysics Data System (ADS)

    Mattsson, Sören; Thomas, Brian J.

    2006-07-01

    This review is focused on experimental methods for determination of the composition of the human body, its organs and tissues. It summarizes the development and current status of fat determinations from body density, total body water determinations through the dilution technique, whole and partial body potassium measurements for body cell mass estimates, in vivo neutron activation analysis for body protein measurements, dual-energy absorptiometry (DEXA), computed tomography (CT) and magnetic resonance imaging (MRI, fMRI) and spectroscopy (MRS) for body composition studies on tissue and organ levels, as well as single- and multiple-frequency bioimpedance (BIA) and anthropometry as simple easily available methods. Methods for trace element analysis in vivo are also described. Using this wide range of measurement methods, together with gradually improved body composition models, it is now possible to quantify a number of body components and follow their changes in health and disease.

  14. 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

  15. 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

  16. Novel methods for studying normal and disordered erythropoiesis.

    PubMed

    Liu, Jing; Han, Xu; An, XiuLi

    2015-12-01

    Erythropoiesis is a process during which multipotential hematopoietic stem cells proliferate, differentiate and eventually form mature erythrocytes. Interestingly, unlike most cell types, an important feature of erythropoiesis is that following each mitosis the daughter cells are morphologically and functionally different from the parent cell from which they are derived, demonstrating the need to study erythropoiesis in a stage-specific manner. This has been impossible until recently due to lack of methods for isolating erythroid cells at each distinct developmental stage. This review summarizes recent advances in the development of methods for isolating both murine and human erythroid cells and their applications. These methods provide powerful means for studying normal and impaired erythropoiesis associated with hematological disorders. PMID:26588913

  17. Explorations in Using Arts-Based Self-Study Methods

    ERIC Educational Resources Information Center

    Samaras, Anastasia P.

    2010-01-01

    Research methods courses typically require students to conceptualize, describe, and present their research ideas in writing. In this article, the author describes her exploration in using arts-based techniques for teaching research to support the development of students' self-study research projects. The pedagogical approach emerged from the…

  18. Introduction to Library Research Methods in Women Studies.

    ERIC Educational Resources Information Center

    Baum, Nathan; And Others

    Prepared as a guide to assist students with library research methods for women's studies course work, the document is divided into five chapters. Chapter one explains how to find books on a specific topic using the subject catalog at Stony Brook's Melville Library. Using a question and answer format the topics covered include subject catalog…

  19. 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.…

  20. Reforming the Social Studies Methods Course. SSEC Publication No. 155.

    ERIC Educational Resources Information Center

    Patrick, John J.

    Numerous criticisms of college social studies methods courses have generated various reform efforts. Three of these reforms are examined, including competency-based teacher education, the value analysis approach to teacher education, and the human relations approach to teacher education. Competency-based courses develop among future teachers…

  1. College Students; Justification for Digital Piracy: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Yu, Szde

    2012-01-01

    A mixed methods project was devoted to understanding college students' justification for digital piracy. The project consisted of two studies, a qualitative one and a quantitative one. Qualitative interviews were conducted to identify main themes in students' justification for digital piracy, and then the findings were tested in a quantitative…

  2. Study of Crack Nucleation Using the Acoustic Emission Method

    NASA Astrophysics Data System (ADS)

    Khazgaliev, R. G.; Dil'mukhametova, A. M.; Astanin, V. V.; Safiullin, R. V.

    2015-10-01

    The effect of two stop-off coatings on the structure and hardness of the surface of the titanium alloy VT6 has been investigated. Data for nondestructive diagnostics of the surface layer have been obtained by the method of acoustic emission. Results of this study can be of use for quality control of hollow parts fabricated from titanium alloys.

  3. Improved Linguistic Fluency with Case Studies and a Video Method.

    ERIC Educational Resources Information Center

    Westerfield, Kay

    1989-01-01

    Describes an English for specific purposes case study course designed to improve both oral and written skills of students about to seek the master of business administration degree. A video method helps to develop fluency in small-group discussion, a skill that is important for other oral classroom activities. (CB)

  4. A Comparative Study of Three Revision Methods in EFL Writing

    ERIC Educational Resources Information Center

    Srichanyachon, Napaporn

    2011-01-01

    In an attempt to explore effective instruction in the English as a Foreign Language (EFL) setting, this study investigated language errors identified by students and teachers in three different revision stages: self-revision, peer revision, and teacher revision. It gave the focus to the effects of the three different methods on learners' writing…

  5. 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...

  6. Case Studies and Methods in Teaching and Learning.

    ERIC Educational Resources Information Center

    Fasko, Daniel, Jr.

    Using case studies and the case method of instruction to improve teaching and learning have been reported in the education literature since the early 1900s. The popularity of these techniques and strategies increased in the 1950s. The impetus for using these strategies came from C. Christensen and A. Hanson, and Moore's "Teaching and the Case…

  7. Child Geopolitical Agency: A Mixed Methods Case Study

    ERIC Educational Resources Information Center

    Habashi, Janette; Worley, Jody

    2009-01-01

    This study examines the geopolitical agency of Palestinian children. Mixed methodology was used to identify the etiologies contributing to processes of political socialization. Both qualitative and qualitative methods are equally distributed throughout this research. Focus groups and interviews with 12 Palestinian children, aged 10 to 13 years,…

  8. In situ observation the interface undercooling of freezing colloidal suspensions with differential visualization method.

    PubMed

    You, Jiaxue; Wang, Lilin; Wang, Zhijun; Li, Junjie; Wang, Jincheng; Lin, Xin; Huang, Weidong

    2015-08-01

    Interface undercooling is one of the most significant parameters in the solidification of colloidal suspensions. However, quantitative measurement of interface undercooling of colloidal suspensions is still a challenge. Here, a new experimental facility and gauging method are designed to directly reveal the interface undercooling on both static and dynamic cases. The interface undercooling is visualized through the discrepancy of solid/liquid interface positions between the suspensions and its solvent in a thermal gradient apparatus. The resolutions of the experimental facility and gauging method are proved to be 0.01 K. The high precision of the method comes from the principle of converting temperature measurement into distance measurement in the thermal gradient platform. Moreover, both static and dynamic interface undercoolings can be quantitatively measured. PMID:26329221

  9. Dental age estimation using Willems method: A digital orthopantomographic study

    PubMed Central

    Mohammed, Rezwana Begum; Krishnamraju, P. V.; Prasanth, P. S.; Sanghvi, Praveen; Lata Reddy, M. Asha; Jyotsna, S.

    2014-01-01

    In recent years, age estimation has become increasingly important in living people for a variety of reasons, including identifying criminal and legal responsibility, and for many other social events such as a birth certificate, marriage, beginning a job, joining the army, and retirement. Objectives: The aim of this study was to assess the developmental stages of left seven mandibular teeth for estimation of dental age (DA) in different age groups and to evaluate the possible correlation between DA and chronological age (CA) in South Indian population using Willems method. Materials and Methods: Digital Orthopantomogram of 332 subjects (166 males, 166 females) who fit the study and the criteria were obtained. Assessment of mandibular teeth (from central incisor to the second molar on left quadrant) development was undertaken and DA was assessed using Willems method. Results and Discussion: The present study showed a significant correlation between DA and CA in both males (r = 0.71 and females (r = 0.88). The overall mean difference between the estimated DA and CA for males was 0.69 ± 2.14 years (P < 0.001) while for females, it was 0.08 ± 1.34 years (P > 0.05). Willems method underestimated the mean age of males by 0.69 years and females by 0.08 years and showed that females mature earlier than males in selected population. The mean difference between DA and CA according to Willems method was 0.39 years and is statistically significant (P < 0.05). Conclusion: This study showed significant relation between DA and CA. Thus, digital radiographic assessment of mandibular teeth development can be used to generate mean DA using Willems method and also the estimated age range for an individual of unknown CA. PMID:25191076

  10. Culture-independent methods for studying environmental microorganisms: methods, application, and perspective.

    PubMed

    Su, Can; Lei, Liping; Duan, Yanqing; Zhang, Ke-Qin; Yang, Jinkui

    2012-02-01

    Since the application of molecular methods, culture-independent methods (CIMs) have been developed to study microbial communities from various environments. In the past 20 years, several methods based on the direct amplification and analyses of the small subunit ribosomal RNA gene have been developed to directly study environmental microorganisms. These methods include denaturing/temperature gradient gel electrophoresis, single-strand-conformation polymorphism, restriction fragment length polymorphism, terminal restriction fragment length polymorphism, and quantitative polymerase chain reaction (PCR). Similarly, non-PCR-based molecular techniques, such as microarray and fluorescence in situ hybridization have also been adopted. In recent years, several novel fields of investigation such as metagenomics, metatranscriptomics, metaproteomics, and single-cell genomics were developed, largely propelled by the innovation and application of next-generation sequencing methods. Several single-cell-based technologies such as Raman microspectroscopy and nano-scale secondary ion mass spectrometry are also increasingly used in the fields of microbial ecology and environmental microbiology. The application of these methods has revolutionized microbiology by allowing scientists to directly analyze natural microbial communities in situ, including their genes, transcripts, proteins, and metabolites and how their interactions impact their distribution patterns. In this review, we present an up-to-date review on different CIMs and their applications, our focuses are on the comparison of different CIMs and their application in the analyses of microbial diversities and communities. PMID:22189863

  11. Instructional Supervision: A Descriptive Study Focusing on the Observation and Evaluation of Teachers in Cyberschools

    ERIC Educational Resources Information Center

    Farley, Gregory Charles

    2010-01-01

    Since 1996, K-12 schools are increasingly moving from a traditional, face-to-face educational environment to an online learning environment utilizing technologies to deliver instruction primarily via the Internet. As this trend continues, administrators familiar with traditional supervisory methods will observe and evaluate teachers of online…

  12. Ionospheric photoelectrons at Venus: Case studies and first observation in the tail

    NASA Astrophysics Data System (ADS)

    Tsang, S. M. E.; Coates, A. J.; Jones, G. H.; Frahm, R. A.; Winningham, J. D.; Barabash, S.; Lundin, R.; Fedorov, A.

    2015-08-01

    The presence of photoelectrons in ionospheres, including that of unmagnetised Venus, can be inferred from their characteristic spectral peaks in the electron energy spectrum. The electrons within the peaks are created by the photoionisation of neutrals in the upper atmosphere by the solar HeII 30.4 nm line. Here, we present some case studies of photoelectron spectra observed by the ASPERA-4 instrument aboard Venus Express with corresponding ion data. In the first case study, we observe photoelectron peaks in the sunlit ionosphere, indicating relatively local production. In the second case study, we observe broadened peaks in the sunlit ionosphere near the terminator, which indicate scattering processes between a more remote production region and the observation point. In the third case study, we present the first observation of ionospheric photoelectrons in the induced magnetotail of Venus, which we suggest is due to the spacecraft being located at that time on a magnetic field line connected to the dayside ionosphere at lower altitudes. Simultaneously, low energy ions are observed moving away from Venus. In common with observations at Mars and at Titan, these imply a possible role for the relatively energetic electrons in producing an ambipolar electric field which enhances ion escape.

  13. 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.

  14. Modeling Observable Signatures of Protoplanetary Disks: Combining Hydrodynamic Simulations with Radiative Transfer Methods

    NASA Astrophysics Data System (ADS)

    Kloster, Dylan; Jang-Condell, Hannah; Kasper, David

    2016-01-01

    New high resolution images of protoplanetary disks from facilities like ALMA are revealing complex disk structures, possibly due to interactions between the disk and newly forming planets within that disk. Analysis of what the structures in these images reveal about the evolution of protoplanetary disks requires detailed models of disk/planet interaction combined with radiative transfer techniques to calculate observable signatures of these disks. We model this disk-planet interaction as hydrodynamic and magnetohydrodynamic numerical simulations using the PLUTO code. We then apply a modified version of the radiative transfer code PaRTY (Parallel Radiative Transfer in YSOs) to these HD/MHD simulations to calculate the observed intensity of these disks via thermal emission and scattering from the host star. Using a wide variety of stellar properties, disk structures, and planet masses, our goal is to produce a robust set of models that will be essential in analyzing the images taken with this new generation of telescopes.

  15. A Method for Mapping the Temperature Profile of X-ray Clusters Through Radio Observations

    E-print Network

    Gilbert Holder; Abraham Loeb

    2003-05-21

    Many of the most luminous extragalactic radio sources are located at the centers of X-ray clusters, and so their radiation must be scattered by the surrounding hot gas. We show that radio observations of the highly-polarized scattered radiation (which depends on the electron density distribution) in combination with the thermal Sunyaev-Zeldovich effect (which measures the electron pressure distribution), can be used to determine the radial profile of the electron temperature within the host cluster. The sensitivity levels expected from current instruments will allow radio measurements of mass-weighted cluster temperature profiles to better than roughly 1 keV accuracy, as long as the central radio source is steady over several million years. Variable or beamed sources will leave observable signatures in the scattered emission. For clusters with a central point source brighter than about 1 mJy, the scattered polarization signal is stronger than competing effects due to the cosmic microwave background.

  16. Antibiotic sales in rural and urban pharmacies in northern Vietnam: an observational study

    PubMed Central

    2014-01-01

    Background The irrational overuse of antibiotics should be minimized as it drives the development of antibiotic resistance, but changing these practices is challenging. A better understanding is needed of practices and economic incentives for antibiotic dispensing in order to design effective interventions to reduce inappropriate antibiotic use. Here we report on both quantitative and qualitative aspects of antibiotic sales in private pharmacies in northern Vietnam. Method A cross-sectional study was conducted in which all drug sales were observed and recorded for three consecutive days at thirty private pharmacies, 15 urban and 15 rural, in the Hanoi region in 2010. The proportion of antibiotics to total drug sales was assessed and the revenue was calculated for rural and urban settings. Pharmacists and drug sellers were interviewed by a semi-structured questionnaire and in-depth interviews to understand the incentive structure of antibiotic dispensing. Results In total 2953 drug sale transactions (2083 urban and 870 rural) were observed. Antibiotics contributed 24% and 18% to the total revenue of pharmacies in urban and rural, respectively. Most antibiotics were sold without a prescription: 88% in urban and 91% in rural pharmacies. The most frequent reported reason for buying antibiotics was cough in the urban setting (32%) and fever in the rural area (22%). Consumers commonly requested antibiotics without having a prescription: 50% in urban and 28% in rural area. The qualitative data revealed that drug sellers and customer’s knowledge of antibiotics and antibiotic resistance were low, particularly in rural area. Conclusion Over the counter sales of antibiotic without a prescription remains a major problem in Vietnam. Suggested areas of improvement are enforcement of regulations and pricing policies and educational programs to increase the knowledge of drug sellers as well as to increase community awareness to reduce demand-side pressure for drug sellers to dispense antibiotics inappropriately. PMID:24555709

  17. Thyroid hormone alterations in trauma patients requiring massive transfusion: An observational study

    PubMed Central

    Hifumi, Toru; Okada, Ichiro; Kiriu, Nobuaki; Hasegawa, Eiju; Ogasawara, Tomoko; Kato, Hiroshi; Koido, Yuichi; Inoue, Junichi; Abe, Yuko; Kawakita, Kenya; Hagiike, Masanobu; Kuroda, Yasuhiro

    2014-01-01

    BACKGROUND: Although non-thyroidal illness syndrome (NTIS) is considered a negative prognostic factor, the alterations in free triiodothyronine (fT3) levels in trauma patients requiring massive transfusion have not been reported. METHODS: A prospective observational study comparing 2 groups of trauma patients was conducted. Group M comprised trauma patients requiring massive transfusions (>10 units of packed red blood cells) within 24 hours of emergency admission. Group C comprised patients with an injury severity score >9 but not requiring massive transfusions. Levels of fT3, free thyroxine (fT4), and thyroid-stimulating hormone (TSH) were evaluated on admission and on days 1, 2, and 7 after admission. The clinical backgrounds and variables measured including total transfusion amounts were compared and the inter-group prognosis was evaluated. Results are presented as mean±standard deviation. RESULTS: Nineteen patients were enrolled in each group. In both groups, 32 were men, and the mean age was 50±24 years. In group C one patient died from respiratory failure. The initial fT3 levels in group M (1.95±0.37 pg/mL) were significantly lower than those in group C (2.49±0.72 pg/mL; P<0.01) and remained low until 1 week after admission. Initial inter-group fT4 and TSH levels were not significantly different. TSH levels at 1 week (1.99±1.64 µIU/mL) were higher than at admission (1.48±0.5 µIU/mL) in group C (P<0.05). CONCLUSION: Typical NTIS was observed in trauma patients requiring massive transfusions. When initial resuscitation achieved circulatory stabilization, prognosis was not strongly associated with NTIS. PMID:25548600

  18. Preliminary study of the applicability of the thin gap method on alpha emitters.

    PubMed

    Horváth, D; Bátor, G; Kovács, T

    2016-01-01

    The thin gap method as an in-situ radiotracer technique is widely used. This study investigated the applicability of alpha emitters. PIPS and CsI alpha spectrometers were applied in a thin gap cell. A suitable (210)Po source was prepared by spontaneous deposition, Mylar foil was used to simulate water. A maximum intensity decrement of 7% within 25?m was observed. Even though this method is suitable for the study of surface phenomena, further investigation is necessary e.g. into water and heat sensitivity. PMID:26562449

  19. Method for observing the features characterizing the surface of a land mass

    NASA Technical Reports Server (NTRS)

    Reed, R. D. (inventor)

    1980-01-01

    A method is described where a propeller driven, hydrazine powered aircraft is remotely piloted through rarefied atmosphere of a selected planet, including the planet Earth. It is employed as a communication platform for a telemetry system provided for relaying information relating to features characterizing the surface of the planet.

  20. 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...

  1. Observation Method to Predict Meander Migration and Vertical Degradation of Rivers 

    E-print Network

    Montalvo Bartolomei, Axel M

    2014-03-05

    and vertical degradation: geometry, flow, and soil. Therefore, there is need for a method that can accurately predict the amount of erosion that may occur in rivers. Six different sites in Texas were selected for this project. Four of the selected rivers have...

  2. Vitamin C supplement use may protect against gallstones: an observational study on a randomly selected population

    PubMed Central

    2009-01-01

    Background Animal experiments have shown a protective effect of vitamin C on the formation of gallstones. Few data in humans suggest an association between reduced vitamin C intake and increased prevalence of gallstone disease. The aim of this study was to assess the possible association of regular vitamin C supplementation with gallstone prevalence. Methods An observational, population-based study of 2129 subjects aged 18-65 years randomly selected from the general population in southern Germany was conducted. Abdominal ultrasound examination, completion of a standardized questionnaire, compilation of anthropometric data and blood tests were used. Data were collected in November and December 2002. Data analysis was conducted between December 2005 and January 2006. Results Prevalence of gallstones in the study population was 7.8% (167/2129). Subjects reporting vitamin C supplementation showed a prevalence of 4.7% (11/232), whereas in subjects not reporting regular vitamin C supplementation, the prevalence was 8.2% (156/1897). Female gender, hereditary predisposition, increasing age and body-mass index (BMI) were associated with increased prevalence of gallstones. Logistic regression with backward elimination adjusted for these factors showed reduced gallstone prevalence for vitamin C supplementation (odds ratio, OR 0.34; 95% confidence interval, CI 0.14 to 0.81; P = 0.01), increased physical activity (OR 0.62; 95% CI, 0.42 to 0.94; P = 0.02), and higher total cholesterol (OR 0.65; 95% CI, 0.52 to 0.79; P < 0.001). Conclusion Regular vitamin C supplementation and, to a lesser extent, increased physical activity and total cholesterol levels are associated with a reduced prevalence of gallstones. Regular vitamin C supplementation might exert a protective effect on the development of gallstones. PMID:19814821

  3. Ipsilateral shoulder pain after thoracic surgery procedures under general and regional anesthesia – a retrospective observational study

    PubMed Central

    Misio?ek, Hanna; Karpe, Jacek; Marcinkowski, Adrian; Jastrz?bska, Aleksandra; Szelka, Anna; Czarno?ycka, Adrianna; D?ugaszek, Micha?

    2014-01-01

    Background Ipsilateral shoulder pain (ISP) is a common complication of mixed etiology after thoracic surgery (its prevalence is estimated in the literature at between 42% and 97%). It is severe and resistant to treatment (patients complain of pain despite effective epidural analgesia at the surgical site). Aim of the study The aim of this retrospective, observational study was to evaluate the prevalence of ISP in patients operated on in our facility and to determine the risk factors for ISP development. Material and methods 68 patients after thoracotomy or videothoracoscopy (video-assisted thoracic surgery – VATS) conducted under general and regional anesthesia were enrolled in the study and divided into two groups: group I without ISP and group II with postoperative ISP. We recorded age, sex, BMI, duration of surgery, type of surgery, type of regional anesthesia, and, in patients with epidural anesthesia, level of catheter placement. Results Statistically significant differences between the groups were obtained for BMI (24.67 and 27.68, respectively; p = 0.049), type of surgery (24% for thoracotomy and 0% for VATS, p = 0.026), and level of epidural catheter placement (4.35% for catheters placed at the level of Th5 or higher and 40.47% for catheters placed below Th5; p = 0.003). Conclusions The prevalence of ISP in our medical center amounts to 24% of thoracotomy patients. The fact that the difference in ISP prevalence was significantly related to the level of epidural catheter placement is consistent with the theory that ISP is related to phrenic nerve innervation. Moreover, epidural catheter placement is a modifiable factor, which can be used to reduce the prevalence of post-thoracotomy ISP. PMID:26336393

  4. Postpyloric enteral nutrition in the critically ill child with shock: a prospective observational study

    PubMed Central

    López-Herce, Jesús; Mencía, Santiago; Sánchez, César; Santiago, Maria J; Bustinza, Amaya; Vigil, Dolores

    2008-01-01

    Background Tolerance to enteral nutrition in the critically ill child with shock has not been studied. The purpose of the study was to analyze the characteristics of enteral nutrition and its tolerance in the critically ill child with shock and to compare this with non-shocked patients. Methods A prospective, observational study was performed including critically ill children with shock who received postpyloric enteral nutrition (PEN). The type of nutrition used, its duration, tolerance, and gastrointestinal complications were assessed. The 65 children with shock who received PEN were compared with 461 non-shocked critically ill children who received PEN. Results Sixty-five critically ill children with shock, aged between 21 days and 22 years, received PEN. 75.4% of patients with shock received PEN exclusively. The mean duration of the PEN was 25.2 days and the maximum calorie intake was 79.4 kcal/kg/day. Twenty patients with shock (30.7%) presented gastrointestinal complications, 10 (15.4%) abdominal distension and/or excessive gastric residue, 13 (20%) diarrhoea, 1 necrotising enterocolitis, and 1 duodenal perforation due to the postpyloric tube. The frequency of gastrointestinal complications was significantly higher than in the other 461 critically ill children (9.1%). PEN was suspended due to gastrointestinal complications in 6 patients with shock (9.2%). There were 18 deaths among the patients with shock and PEN (27.7%). In only one patient was the death related to complications of the nutrition. Conclusion Although most critically ill children with shock can tolerate postpyloric enteral nutrition, the incidence of gastrointestinal complications is higher in this group of patients than in other critically ill children. PMID:18237381

  5. Cerebral perfusion pressure and risk of brain hypoxia in severe head injury: a prospective observational study

    PubMed Central

    Marín-Caballos, Antonio J; Murillo-Cabezas, Francisco; Cayuela-Domínguez, Aurelio; Domínguez-Roldán, Jose M; Rincón-Ferrari, M Dolores; Valencia-Anguita, Julio; Flores-Cordero, Juan M; Muñoz-Sánchez, M Angeles

    2005-01-01

    Introduction Higher and lower cerebral perfusion pressure (CPP) thresholds have been proposed to improve brain tissue oxygen pressure (PtiO2) and outcome. We study the distribution of hypoxic PtiO2 samples at different CPP thresholds, using prospective multimodality monitoring in patients with severe traumatic brain injury. Methods This is a prospective observational study of 22 severely head injured patients admitted to a neurosurgical critical care unit from whom multimodality data was collected during standard management directed at improving intracranial pressure, CPP and PtiO2. Local PtiO2 was continuously measured in uninjured areas and snapshot samples were collected hourly and analyzed in relation to simultaneous CPP. Other variables that influence tissue oxygen availability, mainly arterial oxygen saturation, end tidal carbon dioxide, body temperature and effective hemoglobin, were also monitored to keep them stable in order to avoid non-ischemic hypoxia. Results Our main results indicate that half of PtiO2 samples were at risk of hypoxia (defined by a PtiO2 equal to or less than 15 mmHg) when CPP was below 60 mmHg, and that this percentage decreased to 25% and 10% when CPP was between 60 and 70 mmHg and above 70 mmHg, respectively (p < 0.01). Conclusion Our study indicates that the risk of brain tissue hypoxia in severely head injured patients could be really high when CPP is below the normally recommended threshold of 60 mmHg, is still elevated when CPP is slightly over it, but decreases at CPP values above it. PMID:16356218

  6. Assessing Video Games to Improve Driving Skills: A Literature Review and Observational Study

    PubMed Central

    Sue, Damian; Vichitvanichphong, Suchada

    2014-01-01

    Background For individuals, especially older adults, playing video games is a promising tool for improving their driving skills. The ease of use, wide availability, and interactivity of gaming consoles make them an attractive simulation tool. Objective The objective of this study was to look at the feasibility and effects of installing video game consoles in the homes of individuals looking to improve their driving skills. Methods A systematic literature review was conducted to assess the effect of playing video games on improving driving skills. An observatory study was performed to evaluate the feasibility of using an Xbox 360 Kinect console for improving driving skills. Results Twenty–nine articles, which discuss the implementation of video games in improving driving skills were found in literature. On our study, it was found the Xbox 360 with Kinect is capable of improving physical and mental activities. Xbox Video games were introduced to engage players in physical, visual and cognitive activities including endurance, postural sway, reaction time, eyesight, eye movement, attention and concentration, difficulties with orientation, and semantic fluency. However, manual dexterity, visuo-spatial perception and binocular vision could not be addressed by these games. It was observed that Xbox Kinect (by incorporating Kinect sensor facilities) combines physical, visual and cognitive engagement of players. These results were consistent with those from the literature review. Conclusions From the research that has been carried out, we can conclude that video game consoles are a viable solution for improving user’s physical and mental state. In future we propose to carry a thorough evaluation of the effects of video games on driving skills in elderly people. PMID:25654355

  7. Active Vitamin D and Accelerated Progression of Aortic Stiffness in Hemodialysis Patients: A Longitudinal Observational Study

    PubMed Central

    Fortier, Catherine; Mac-Way, Fabrice; De Serres, Sacha A.; Marquis, Karine; Douville, Pierre; Desmeules, Simon; Larivière, Richard

    2014-01-01

    BACKGROUND We hypothesized that high-dose active vitamin D therapy in the form of alphacalcidol (?-calcidol), used to treat secondary hyperparathyroidism in chronic kidney disease, could lead to vascular calcification and accelerated progression of aortic stiffness. METHODS We conducted an observational study in 85 patients on chronic hemodialysis, among which 70 were taking a weekly dose of ?-calcidol of <2 µg and 15 were taking a weekly dose of ?2 µg (pharmacological dose). Parathyroid hormone, 25-hydroxyvitamin D, fibroblast growth factor 23, and ?-klotho were determined. Aortic stiffness was assessed by determination of carotid–femoral pulse wave velocity (cf-PWV) at baseline and after a mean follow-up of 1.2 years. A multivariable regression model was used to evaluate the impact of pharmacological dose of ?-calcidol on the progression of aortic stiffness. RESULTS At baseline, clinical, biological, and hemodynamic parameters were similar. At follow-up, cf-PWV increased more in patients with pharmacological dose of ?-calcidol (0.583±2.291 m/s vs. 1.948±1.475 m/s; P = 0.04). After adjustment for changes in mean blood pressure and duration of follow-up, pharmacological dose of ?-calcidol was associated with a higher rate of progression of cf-PWV (0.969 m/s; 95% confidence interval = 0.111–1.827; P = 0.03), and this association persisted after further adjustments for parameters of mineral metabolism. CONCLUSIONS In this study, pharmacological dose of ?-calcidol was associated with accelerated progression of aortic stiffness. This study suggest that the vascular safety of active vitamin D posology may need to be specifically addressed in the treatment of chronic kidney disease–related bone mineral disorder. PMID:24695980

  8. Patient Safety Incidents During Overnight Polysomnography: A Five-Year Observational Cohort Study

    PubMed Central

    Kolla, Bhanu Prakash; Lam, Erek; Olson, Eric; Morgenthaler, Timothy

    2013-01-01

    Introduction: Attended polysomnography (PSG) is a common procedure and is regarded as relatively safe. There have been few systematic evaluations of adverse events occurring during PSG. An understanding of the frequency and type of the adverse events during PSG should inform risk mitigation plans and the development of guidelines for sleep center accreditation. We aimed to identify, tabulate, and classify all adverse events that occurred during overnight PSG conducted at an accredited sleep center over a five-year period. Methods: All adverse events occurring from Jan 1, 2005, to Dec 31, 2010, at the Center for Sleep Medicine, Mayo Clinic, were identified. Information was collated from calls made to emergency responders, to the adverse event reporting system, and events forwarded to the medical director. Results: A total of 36,141 PSGs were performed over the study duration. Fifty-eight adverse events occurred during the study period (1 event/623 PSGs). Most adverse events were cardiac in nature (17/58; 29.3%), a majority involving acute chest pain. Falls were the next most common (20.6%), followed by neurologic (8.6%), pulmonary (3.4%), and psychiatric (3.4%) events. The rest were classified as miscellaneous. There were no patient deaths during PSGs. The majority of patients experiencing an adverse event were transported to the emergency room (37/58; 63.79%). Of these, 15/37 (40.54%) were admitted to the hospital, and 3 required an ICU bed. Conclusion: Adverse events during a PSG were relatively uncommon. Previous emphasis on cardiac arrhythmias may be overstated, as chest pain and patient falls were commonest and resulted in hospitalization more often. Citation: Kolla BP; Lam E; Olson E; Morgenthaler T. Patient safety incidents during overnight polysomnography: a five-year observational cohort study. J Clin Sleep Med 2013;9(11):1201-1205. PMID:24235904

  9. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 19, METHOD 609 (NITROAROMATICS AND ISOPHORONE)

    EPA Science Inventory

    An interlaboratory study in which 18 laboratories participated was conducted to provide precision and accuracy statements for the proposed EPA Method 609 for measuring concentrations of the Category 4 chemicals nitrobenzene, isophorone, 2,4-dinitrotoluene and 2,6-dinitrotoluene i...

  10. Integrability: mathematical methods for studying solitary waves theory

    NASA Astrophysics Data System (ADS)

    Wazwaz, Abdul-Majid

    2014-03-01

    In recent decades, substantial experimental research efforts have been devoted to linear and nonlinear physical phenomena. In particular, studies of integrable nonlinear equations in solitary waves theory have attracted intensive interest from mathematicians, with the principal goal of fostering the development of new methods, and physicists, who are seeking solutions that represent physical phenomena and to form a bridge between mathematical results and scientific structures. The aim for both groups is to build up our current understanding and facilitate future developments, develop more creative results and create new trends in the rapidly developing field of solitary waves. The notion of the integrability of certain partial differential equations occupies an important role in current and future trends, but a unified rigorous definition of the integrability of differential equations still does not exist. For example, an integrable model in the Painlevé sense may not be integrable in the Lax sense. The Painlevé sense indicates that the solution can be represented as a Laurent series in powers of some function that vanishes on an arbitrary surface with the possibility of truncating the Laurent series at finite powers of this function. The concept of Lax pairs introduces another meaning of the notion of integrability. The Lax pair formulates the integrability of nonlinear equation as the compatibility condition of two linear equations. However, it was shown by many researchers that the necessary integrability conditions are the existence of an infinite series of generalized symmetries or conservation laws for the given equation. The existence of multiple soliton solutions often indicates the integrability of the equation but other tests, such as the Painlevé test or the Lax pair, are necessary to confirm the integrability for any equation. In the context of completely integrable equations, studies are flourishing because these equations are able to describe the real features in a variety of vital areas in science, technology and engineering. In recognition of the importance of solitary waves theory and the underlying concept of integrable equations, a variety of powerful methods have been developed to carry out the required analysis. Examples of such methods which have been advanced are the inverse scattering method, the Hirota bilinear method, the simplified Hirota method, the Bäcklund transformation method, the Darboux transformation, the Pfaffian technique, the Painlevé analysis, the generalized symmetry method, the subsidiary ordinary differential equation method, the coupled amplitude-phase formulation, the sine-cosine method, the sech-tanh method, the mapping and deformation approach and many new other methods. The inverse scattering method, viewed as a nonlinear analogue of the Fourier transform method, is a powerful approach that demonstrates the existence of soliton solutions through intensive computations. At the center of the theory of integrable equations lies the bilinear forms and Hirota's direct method, which can be used to obtain soliton solutions by using exponentials. The Bäcklund transformation method is a useful invariant transformation that transforms one solution into another of a differential equation. The Darboux transformation method is a well known tool in the theory of integrable systems. It is believed that there is a connection between the Bäcklund transformation and the Darboux transformation, but it is as yet not known. Archetypes of integrable equations are the Korteweg-de Vries (KdV) equation, the modified KdV equation, the sine-Gordon equation, the Schrödinger equation, the Vakhnenko equation, the KdV6 equation, the Burgers equation, the fifth-order Lax equation and many others. These equations yield soliton solutions, multiple soliton solutions, breather solutions, quasi-periodic solutions, kink solutions, homo-clinic solutions and other solutions as well. The couplings of linear and nonlinear equations were recently discovered and subsequently received considerable attention. Th

  11. A method for evaluating the thrust of a space propulsion device with wide range time variations using a disturbance observer.

    PubMed

    Kakami, Akira; Muto, Takuya; Yano, Yasuyuki; Tachibana, Takeshi

    2015-11-01

    A new method for evaluating thrust with high-frequency variations beyond the resonant frequency using a disturbance observer is presented. Setpoint control is applied to a conventional pendulum-type thrust stand to keep the pendulum at the target position using a solenoid actuator. During control, pendulum acceleration and solenoid-actuator current are measured, and the disturbance observer determines thrust with a wide range of frequency variations. The method allows thrust to be evaluated not only with constant and low-frequency variations, but also with high-frequency variations outside the resonant frequency. A thrust measurement device is prototyped to investigate accuracy over a wide frequency range from 0 to 100 Hz and the effects of the proportional-derivative-integral (PID) controller design. Calibration yields thrust measurement errors of 20% below 90 Hz. PID controller design has a smaller influence on the accuracy of the proposed method than the conventional null-balance method, so the proposed method requires the same stability under PID control as that for the null-balance method. PMID:26628179

  12. A method for evaluating the thrust of a space propulsion device with wide range time variations using a disturbance observer

    NASA Astrophysics Data System (ADS)

    Kakami, Akira; Muto, Takuya; Yano, Yasuyuki; Tachibana, Takeshi

    2015-11-01

    A new method for evaluating thrust with high-frequency variations beyond the resonant frequency using a disturbance observer is presented. Setpoint control is applied to a conventional pendulum-type thrust stand to keep the pendulum at the target position using a solenoid actuator. During control, pendulum acceleration and solenoid-actuator current are measured, and the disturbance observer determines thrust with a wide range of frequency variations. The method allows thrust to be evaluated not only with constant and low-frequency variations, but also with high-frequency variations outside the resonant frequency. A thrust measurement device is prototyped to investigate accuracy over a wide frequency range from 0 to 100 Hz and the effects of the proportional-derivative-integral (PID) controller design. Calibration yields thrust measurement errors of 20% below 90 Hz. PID controller design has a smaller influence on the accuracy of the proposed method than the conventional null-balance method, so the proposed method requires the same stability under PID control as that for the null-balance method.

  13. The study of enhanced earth observations on a satellite image chain

    NASA Astrophysics Data System (ADS)

    Yong, Sang-Soon; Choi, Myungjin; Ra, Sung-Woong

    2011-10-01

    The Multi-Spectral Camera (MSC) on the KOrea Multi-Propose SATellite (KOMPSAT)-2 was developed and launched as a main payload to provide a One(1) m panchromatic image and four(4) band four(4) m multi-spectral images at an altitude of 685 km covering a swath width of 15 km. These images, archived around the world, are a useful resource for space applications in agriculture, cartography, geology, forestry, regional planning, surveillance, and national security. The image quality of KOMPSAT-2 depends upon its image chain, which is comprised of an on-board system in the satellite and a processing system at the ground station. Therefore, in this study we determine the factors that have a major impact on the image quality through an investigation of the entire image chain. Consequently, two methods, involving a compression algorithm and a deconvolution technique, were determined as having a significant influence on the KOMPSAT-2 image quality. The compression algorithm of KOMPSAT-2 is rate-controlled JPEG-like algorithm that controls the mismatch between the input and output data rate. The ability to control the input/output data rate may be useful during the operation of the satellite but can also lower the overall image quality. The deconvolution technique may increase the sharpness of images, but it can also amplify the image noise level. Therefore, we propose methods of wavelet-based compression and denoising as an alternative to currently existing algorithms. Satisfactory results were obtained through experimentation with these two algorithms, and they are expected to be successfully implemented into the future KOMPSAT series to yield high-quality images for enhanced earth observation.

  14. 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.

  15. Analysis and study of magnetospheric ULF waves using multi-spacecraft and ground-based observations

    NASA Astrophysics Data System (ADS)

    Balasis, Georgios; Daglis, Ioannis A.; Papadimitriou, Constantinos; Georgiou, Marina; Giamini, Sigiava

    In the past decade, a critical mass of high-quality scientific data on the electric and magnetic fields in the Earth’s magnetosphere and topside ionosphere has been progressively collected. This data pool will be further enriched by the measurements of ESA's Swarm mission, a constellation of three satellites in three different polar orbits between 400 and 550 km altitude, which was launched on the 22nd of November 2013. New analysis tools that can cope with measurements of various spacecraft at various regions of the magnetosphere and in the topside ionosphere as well as ground stations will effectively enhance the scientific exploitation of the accumulated data. Here, we report on a new suite of algorithms aiming at automated detection and classification of ultra-low frequency (ULF) wave events. Our approach is based on a combination of wavelet spectral methods and artificial neural network techniques. Moreover, we demonstrate the applicability of these recently developed analysis tools both for individual case studies and statistical studies of ULF waves. First, we provide evidence for a rare simultaneous observation of a ULF wave event in the Earth's magnetosphere, topside ionosphere and surface: we have found a specific time interval during the Halloween 2003 magnetic storm, when the Cluster and CHAMP spacecraft were in good local time (LT) conjunction, and have examined the ULF wave activity in the Pc3 (22-100 mHz) and Pc4-5 (1-22 mHz) frequency bands using data from the Geotail, Cluster and CHAMP missions, as well as the CARISMA and GIMA magnetometer networks. Then, we perform a statistical study of Pc3 wave events observed by CHAMP: the creation of a database of such events enabled us to derive valuable statistics for many important physical properties relating to the spatio-temporal location of these waves, the wave power and frequency, as well as other parameters and their correlation with solar wind conditions, magnetospheric indices, electron density data, ring current decay and radiation belt enhancements.

  16. 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

  17. Medication use in European primary care patients with lower respiratory tract infection: an observational study

    PubMed Central

    Hamoen, Marleen; Broekhuizen, Berna DL; Little, Paul; Melbye, Hasse; Coenen, Samuel; Goossens, Herman; Butler, Chris C; Francis, Nick A; Verheij, Theo JM

    2014-01-01

    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

  18. Methods to study the tumor microenvironment under controlled oxygen conditions

    PubMed Central

    Byrne, Matthew B.; Leslie, Matthew T.; Gaskins, H. Rex; Kenis, Paul J.A.

    2014-01-01

    The tumor microenvironment is a complex heterogeneous assembly composed of a variety of cell types and physical features. One such feature, hypoxia, is associated with metabolic reprogramming, the epithelial-mesenchymal transition, and therapeutic resistance. Many questions remain regarding the effects of hypoxia on these outcomes, yet only few experimental methods enable both precise control over oxygen concentration and real-time imaging of cell behavior. Recent efforts with microfluidic platforms offer a promising solution to these limitations. We discuss conventional methods and tools used to control oxygen concentration for cell studies then highlight recent advances in microfluidic-based approaches for controlling oxygen in engineered platforms. PMID:25282035

  19. Methods to study molecular mechanisms of the Neurospora circadian clock.

    PubMed

    Cha, Joonseok; Zhou, Mian; Liu, Yi

    2015-01-01

    Eukaryotic circadian clocks are comprised of interlocked autoregulatory feedback loops that control gene expression at the levels of transcription and translation. The filamentous fungus Neurospora crassa is an excellent model for the complex molecular network of regulatory mechanisms that are common to all eukaryotes. At the heart of the network, posttranslational regulation and functions of the core clock elements are of major interest. This chapter discusses the methods used currently to study the regulation of clock molecules in Neurospora. The methods range from assays of gene expression to phosphorylation, nuclear localization, and DNA binding of clock proteins. PMID:25662455

  20. Prescribing patterns in dementia: a multicentre observational study in a German network of CAM physicians

    PubMed Central

    2011-01-01

    Background Dementia is a major and increasing health problem worldwide. This study aims to investigate dementia treatment strategies among physicians specialised in complementary and alternative medicine (CAM) by analysing prescribing patterns and comparing them to current treatment guidelines in Germany. Methods Twenty-two primary care physicians in Germany participated in this prospective, multicentre observational study. Prescriptions and diagnoses were reported for each consecutive patient. Data were included if patients had at least one diagnosis of dementia according to the 10th revision of the International Classification of Diseases during the study period. Multiple logistic regression was used to determine factors associated with a prescription of any anti-dementia drug including Ginkgo biloba. Results During the 5-year study period (2004-2008), 577 patients with dementia were included (median age: 81 years (IQR: 74-87); 69% female). Dementia was classified as unspecified dementia (57.2%), vascular dementia (25.1%), dementia in Alzheimer's disease (10.4%), and dementia in Parkinson's disease (7.3%). The prevalence of anti-dementia drugs was 25.6%. The phytopharmaceutical Ginkgo biloba was the most frequently prescribed anti-dementia drug overall (67.6% of all) followed by cholinesterase inhibitors (17.6%). The adjusted odds ratio (AOR) for receiving any anti-dementia drug was greater than 1 for neurologists (AOR = 2.34; CI: 1.59-3.47), the diagnosis of Alzheimer's disease (AOR = 3.28; CI: 1.96-5.50), neuroleptic therapy (AOR = 1.87; CI: 1.22-2.88), co-morbidities hypertension (AOR = 2.03; CI: 1.41-2.90), and heart failure (AOR = 4.85; CI: 3.42-6.88). The chance for a prescription of any anti-dementia drug decreased with the diagnosis of vascular dementia (AOR = 0.64; CI: 0.43-0.95) and diabetes mellitus (AOR = 0.55; CI: 0.36-0.86). The prescription of Ginkgo biloba was associated with sex (female: AOR = 0.41; CI: 0.19-0.89), patient age (AOR = 1.06; CI: 1.02-1.10), treatment by a neurologist (AOR = 0.09; CI: 0.03-0.23), and the diagnosis of Alzheimer's disease (AOR = 0.07; CI: 0.04-0.16). Conclusions This study provides a comprehensive analysis of everyday practice for treatment of dementia in primary care in physicians with a focus on CAM. The prescribing frequency for anti-dementia drugs is equivalent to those found in other German studies, while the administration of Ginkgo biloba is significantly higher. PMID:21824429

  1. Recent vs Conventional Methods of Caries Removal: A Comparative in vivo Study in Pediatric Patients

    PubMed Central

    Saha, Sonali; Samadi, Firoza; Jaiswal, JN; Garg, Aarti; Chowdhry, Preet

    2015-01-01

    ABSTRACT Aims: To compare the three different methods of caries removal, conventional method using Airotor and chemomechanical method using Carisolv and Papacarie. Settings and design: The patients with multiple carious teeth were selected either in the deciduous dentition or mixed dentition. Ninety primary molars were selected from 30 children (10 males and 20 females) between the age group 6 and 9 years. Materials and methods: After caries excavation, cavities were evaluated for caries removal or clinical efficacy by the tactile and visual criteria, microbiological efficacy, time taken for the procedure. Patient acceptability toward the treatment was also checked with the help of a visual analog scale (VAS). The observations thus obtained were subjected to statistical analysis using analysis of variance (ANOVA), Mann-Whitney U-test and Kruskal-Wallis test. Results: The clinical efficacy of caries removal was highest with Airotor while the microbiological efficacy of caries removal was almost comparable with Airotor, Carisolv and Papacarie caries removal methods. The time taken to remove caries by Airotor method was observed to be least while the patient acceptance was found to be highest with Papacarie method. How to cite this article: Chowdhry S, Saha S, Samadi F, Jaiswal JN, Garg A, Chowdhry P. Recent vs Conventional Methods of Caries Removal: A Comparative in vivo Study in Pediatric Patients. Int J Clin Pediatr Dent 2015;8(1):6-11. PMID:26124574

  2. The JScanam Map-Maker Method Applied to Herschel/PACS Photometer Observations

    E-print Network

    Graciá-Carpio, Javier; Roussel, Hélène

    2015-01-01

    JScanam is the default map-maker for Herschel/PACS photometer observations. Making use of the redundant information from multiple passages on the sky with different scanning directions, JScanam is able to remove the $1/f$ noise that severely affects PACS far-infrared maps, preserving at the same time point sources and real extended emission. The JScanam pipeline has been designed to run automatically on all kind of maps and astronomical environments, from Galactic star-forming clouds to deep cosmological fields. The results from the JScanam automatic pipeline can be easily inspected and downloaded from the Herschel Science Archive and the new ESA Sky interface.

  3. 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

  4. 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

  5. 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

  6. Using Mixed Integer Programming for Matching in an Observational Study of Kidney Failure after

    E-print Network

    Using Mixed Integer Programming for Matching in an Observational Study of Kidney Failure after-control study of acute kidney injury after surgery among Medicare patients illustrates these features in detail: Motivating Example; Review of Matching; Outline 1.1 Motivating example: obesity and acute kidney injuries

  7. 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...

  8. Junior High Classroom Organization Study. Observer Training Manual. R&D Rep. No. 6102.

    ERIC Educational Resources Information Center

    Texas Univ., Austin. Research and Development Center for Teacher Education.

    This manual was used to train observers for the Junior High Classroom Organization Study, a research project developed to delineate specific effective teacher behaviors. During the training sessions, the following topics were discussed: 1) preliminary results from a previously conducted Third-Grade Classroom Organization Study; 2) concepts and…

  9. 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…

  10. Using and Experiencing the Academic Library: A Multisite Observational Study of Space and Place

    ERIC Educational Resources Information Center

    May, Francine; Swabey, Alice

    2015-01-01

    This study examines how students are using academic library spaces and the role these spaces are playing in the campus community. Data were collected on five campuses (two community colleges, two undergraduate universities, and one technical institute) via observational seating sweeps and questionnaires. The study found remarkably similar usage…

  11. The Study of System Response Parameter Calibration Method for Xinanjiang Model Parameters

    NASA Astrophysics Data System (ADS)

    Si, W.; Bao, W.; Wang, Z.; Qu, S.

    2014-12-01

    Non-linear function parameter calibration is usually based on the objective function of minimum error square sum, which including the construction of objective function and the first-order derivation of objective function. Since the traditional non-linear parameter calibration will introduce unrelated local optimums, a new non-linear parameter calibration method- the system response parameter calibration method was proposed in the paper. The nonlinear parameter can be linearized by this method which can reduce the un-related local optimums. In this study, the system response parameter calibration method was applied in the Xinanjiang model parameter calibration. The Xinanjiang (XAJ) model was generalized into a system. The changes of model parameters were considered as the input of the system. According to the system response curve caused by the changes of parameters need to be calibrated, the optimal parameters would be calculated using least square estimation based on the observed and calculated discharge. Firstly, the method was tested by an ideal scenario. The results showed that the method can find the given optimums very efficiently. Secondly, the performance of the linearized calibration method in model parameter calibration was studied using real data. The results showed that the system response parameter calibration method was an effective calibration method.

  12. The German Young Olympic Athletes' Lifestyle and Health Management Study (GOAL Study): design of a mixed-method study

    PubMed Central

    2011-01-01

    Background In order to perform at top levels, elite athletes have to both protect and risk their health at the same time. Adolescent elite athletes have the additional challenge of coping with substantial physical, psychological and social transformations. The contradictory phenomenon of protecting and risking the adolescent athletes' health in sports challenges the development of health promotion and protection strategies. The GOAL Study (German Young Olympic Athletes' Lifestyle and Health Management Study) analyzes the individual and organizational management of health in adolescent elite sports. Methods/design We combine quantitative and qualitative approaches in a mixed-method study. This allows us to gather a broad range of representative information on squad athletes from all Olympic disciplines as well as in-depth information on four selected Olympic disciplines (artistic gymnastics, biathlon, handball and wrestling). Within the quantitative section we attempt to identify the young athletes' health and nutrition behavior, their subjective health state and their lay health representations, health-related social networks, and structures of medical attendance. 1138 national team level athletes born between 1992 and 1995 from 51 Olympic disciplines responded to the questionnaire (response rate: 61,75%). The qualitative section investigates the meaning and relevance of health and nutrition within the athletes' sports specific surroundings, the impact of biographic backgrounds on individual health behavior, and sports specific cultures of health, nutrition and risk. We interviewed 24 athletes and 28 coaching and medical experts, and carried out 14 multi-day participant observations at training sessions and competitions. Conclusions The studies' results will serve as the basis for developing tailored health promotion strategies to be in cooperation with German elite sports associations. PMID:21627777

  13. Comorbidities of patients in tiotropium clinical trials: comparison with observational studies of patients with chronic obstructive pulmonary disease

    PubMed Central

    Miravitlles, Marc; Price, David; Rabe, Klaus F; Schmidt, Hendrik; Metzdorf, Norbert; Celli, Bartolome

    2015-01-01

    Background There is an ongoing debate on whether patients with chronic obstructive pulmonary disease (COPD) seen in real-life clinical settings are represented in randomized controlled trials (RCTs) of COPD. It is thought that the stringent inclusion and exclusion criteria of RCTs may prevent the participation of patients with specific characteristics or risk factors. Methods We surveyed a database of patients recruited into 35 placebo-controlled tiotropium RCTs and also conducted a systematic literature review of large-scale observational studies conducted in patients with a documented diagnosis of COPD between 1990 and 2013. Patient demographics and comorbidities with a high prevalence in patients with COPD were compared between the two patient populations at baseline. Using the Medical Dictionary for Regulatory Activities (MedDRA; v 14.0), patient comorbidities in the pooled tiotropium RCTs were classified according to system organ class, pharmacovigilance (PV) endpoints, and Standardised MedDRA Queries to enable comparison with the observational studies. Results We identified 24,555 patients in the pooled tiotropium RCTs and 61,361 patients among the 13 observational studies that met our search criteria. The Global initiative for chronic Obstructive Lung Disease (GOLD) staging of patients in the RCTs differed from that in observational studies: the proportion of patients with GOLD stages I+II disease ranged from 40.0% to 51.5% in the RCTs but 24.5% to 44.1% in the observational studies; for GOLD stage III or IV disease these ranges were 7.2%–45.8% (RCTs) and 13.7–42.1% (observational studies). The comorbidities with the highest prevalence reported in the RCTs and observational studies were: hypertension (39.4%–40.0% vs 40.1%–60.6%), other ischemic heart disease (12.3%–14.2% vs 12.5%–41.0%), diabetes (10.3%–10.9% vs 4.0%–38.9%), depression (8.5%–9.5% vs 17.0%–20.6%), and cardiac arrhythmia (7.8%–11.4% vs 11.3%–15.8%). Conclusion The clinical profile of COPD patients treated in the tiotropium trial program appears to be largely in the range of clinical characteristics, including cardiovascular comorbidities, reported for “real-life patients.” The tiotropium RCTs tended to include patients with more severe disease than the observational studies. PMID:25834416

  14. Association of Vitamin E Intake with Reduced Risk of Kidney Cancer: A Meta-Analysis of Observational Studies.

    PubMed

    Shen, Chongxing; Huang, Ying; Yi, Shanhong; Fang, Zhenqiang; Li, Longkun

    2015-01-01

    BACKGROUND Several observational studies suggested that vitamin E intake is related to the risk of kidney cancer; however, the results of published studies are inconsistent. MATERIAL AND METHODS A meta-analysis was performed to assess the relationship between vitamin E intake and the risk of kidney cancer by searching PubMed and Medline through August 2015. We computed pooled relative risks (RR) and 95%CI of kidney cancer for the highest versus lowest level of vitamin E intake. RESULTS A total of 13 observational studies (7 case-control and 6 cohort) were included. The pooled RR (95%CI) of kidney cancer for the highest vs. the lowest level of vitamin E intake was 0.81 (0.69-0.94). In subgroup-analysis, this study found an inverse relationship between vitamin E intake and kidney cancer risk, which was not significantly modified by study design, study population, or sex distribution except in the cohort studies. CONCLUSIONS Results of the present study suggest an inverse relationship between vitamin E intake and kidney cancer risk. However, additional well designed cohort studies and randomized controlled trials that focus on the relationship between vitamin E intake and kidney cancer risk are needed. PMID:26547129

  15. Association of Vitamin E Intake with Reduced Risk of Kidney Cancer: A Meta-Analysis of Observational Studies

    PubMed Central

    Shen, Chongxing; Huang, Ying; Yi, Shanhong; Fang, Zhenqiang; Li, Longkun

    2015-01-01

    Background Several observational studies suggested that vitamin E intake is related to the risk of kidney cancer; however, the results of published studies are inconsistent. Material/Methods A meta-analysis was performed to assess the relationship between vitamin E intake and the risk of kidney cancer by searching PubMed and Medline through August 2015. We computed pooled relative risks (RR) and 95%CI of kidney cancer for the highest versus lowest level of vitamin E intake. Results A total of 13 observational studies (7 case-control and 6 cohort) were included. The pooled RR (95%CI) of kidney cancer for the highest vs. the lowest level of vitamin E intake was 0.81 (0.69–0.94). In subgroup-analysis, this study found an inverse relationship between vitamin E intake and kidney cancer risk, which was not significantly modified by study design, study population, or sex distribution except in the cohort studies. Conclusions Results of the present study suggest an inverse relationship between vitamin E intake and kidney cancer risk. However, additional well designed cohort studies and randomized controlled trials that focus on the relationship between vitamin E intake and kidney cancer risk are needed. PMID:26547129

  16. Magnetopause properties from AMPTE/IRM observations of the convection electric field: Method development

    SciTech Connect

    Sonnerup, B.U.O. ); Papamastorakis, I. Max-Planck-Inst. fuer Physik und Astrophysik, Garching ); Paschmann, G. ); Luh