Science.gov

Sample records for observational studies methods

  1. Problematising Short-Term Participant Observation and Multi-Method Ethnographic Studies

    ERIC Educational Resources Information Center

    Brockmann, Michaela

    2011-01-01

    This article reports on a study of apprentices in England and Germany designed to explore young people's learner identities over time and in relation to particular learning environments. The research adopts a multi-method ethnographic approach, combining biographical interviews with multi-site participant observation. The article problematises the

  2. Comparison of methods of extracting information for meta-analysis of observational studies in nutritional epidemiology

    PubMed Central

    2016-01-01

    OBJECTIVES: A common method for conducting a quantitative systematic review (QSR) for observational studies related to nutritional epidemiology is the “highest versus lowest intake” method (HLM), in which only the information concerning the effect size (ES) of the highest category of a food item is collected on the basis of its lowest category. However, in the interval collapsing method (ICM), a method suggested to enable a maximum utilization of all available information, the ES information is collected by collapsing all categories into a single category. This study aimed to compare the ES and summary effect size (SES) between the HLM and ICM. METHODS: A QSR for evaluating the citrus fruit intake and risk of pancreatic cancer and calculating the SES by using the HLM was selected. The ES and SES were estimated by performing a meta-analysis using the fixed-effect model. The directionality and statistical significance of the ES and SES were used as criteria for determining the concordance between the HLM and ICM outcomes. RESULTS: No significant differences were observed in the directionality of SES extracted by using the HLM or ICM. The application of the ICM, which uses a broader information base, yielded more-consistent ES and SES, and narrower confidence intervals than the HLM. CONCLUSIONS: The ICM is advantageous over the HLM owing to its higher statistical accuracy in extracting information for QSR on nutritional epidemiology. The application of the ICM should hence be recommended for future studies. PMID:26797219

  3. 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.

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

    PubMed Central

    Pfeffermann, Danny; Landsman, Victoria

    2011-01-01

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

  5. 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.

  6. The barrier method as a new tool to assist in career selection: covert observational study

    PubMed Central

    2010-01-01

    Objective To determine if senior doctors parking habits and skills are associated with clinical specialty and, if so, whether observation of junior doctors parking could provide guidance in choice of specialty. Design Covert observational study. Setting Pass-card controlled consultants car park (parking lot), December 2009. Participants 103 consultants entering the car park on three consecutive mornings. Main outcome measures The outcomes were specialty and sex of the consultants, manner of approaching the barrier (pass-card ready or not), and time taken to park, exit the vehicle, and walk to a designated point. Results Approaches to the barrier and parking were recorded for 103 consultants (79 men, 24 women): 28 anaesthetists (22 men, six women), 29 physicians (internists, 18 men, 11 women), 14 radiologists (nine men, five women), and 32 surgeons (30 men, two women). The manner of approaching the barrier (card ready) differed by specialty but not by sex. The total time taken to park (seconds) differed significantly between specialties: surgery (median 68, interquartile range 61-71 seconds), anaesthesia (82, 76-91), radiology (86, 70-103), and general medicine (112, 96-136). The time taken to park was overall longer among women, but this was explained by their specialty (men and women matched by specialty did not differ). Conclusions The total time taken to park and manner of approaching the barrier to gain entry to the car park differed across specialties. Surgical consultants were fastest, followed by consultant anaesthetists and consultant radiologists, with physicians slowest. Sex was not an influencing factor. If reproducible in studies of a similar nature the barrier method could allow for a low cost means of guiding junior doctors in career selection. PMID:21159762

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

    ERIC Educational Resources Information Center

    Austin, Peter C.

    2011-01-01

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

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

    ERIC Educational Resources Information Center

    Austin, Peter C.

    2011-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald G.

    2001-01-01

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

  10. 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.

  11. 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.

  12. Volcanic emissions from AIRS observations: detection methods, case study, and statistical analysis

    NASA Astrophysics Data System (ADS)

    Hoffmann, Lars; Griessbach, Sabine; Meyer, Catrin I.

    2014-10-01

    Monitoring volcanic emissions is important for many reasons, most notably for impacts on climate and possible hazards for human health or aviation safety. Satellite instruments allow for long-term monitoring of volcanic emissions on a global scale. In this paper we introduce new detection indices for volcanic ash and sulfur dioxide (SO2) that are optimized for radiance measurements of the Atmospheric InfraRed Sounder (AIRS). Radiative transfer calculations are used to determine the sensitivity of the ash index (AI) on the aerosol optical depth and the SO2 index (SI) on the SO2 column density. A case study on AIRS observations after the eruption of the Puyehue Cordon-Caulle, Chile, in June 2011 demonstrates that the new indices work in practice. A statistical analysis of a ten-year record (2002 to 2013) of AIRS data provides AI thresholds that help to better discriminate volcanic emissions from regular events such as dust storms. We compared our new SI with the AIRS operational product and found that it is more sensitive and better suppresses interfering background signals. Our new volcanic emission data products have been successfully applied in other scientific studies.

  13. 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...

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    Using nightside electron density profiles obtained with radio occultation data from the Viking orbiters, the nightside ionospheres of Mars and Venus are investigated. It is shown that the Mars nightside ionosphere is generally weaker than the Venus nightside ionosphere, and, when it is present, the peak altitude is higher. Otherwise, there is considerable similarity. In particular, the dependence of peak density on solar zenith angle in the range of the Viking nightside observations (90-130 deg) is found to be similar for both planets.

  15. 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.

  16. 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

  17. Exploring the Current Landscape of Intravenous Infusion Practices and Errors (ECLIPSE): protocol for a mixed-methods observational study

    PubMed Central

    Blandford, Ann; Furniss, Dominic; Chumbley, Gill; Iacovides, Ioanna; Wei, Li; Cox, Anna; Mayer, Astrid; Schnock, Kumiko; Bates, David Westfall; Dykes, Patricia C; Bell, Helen; Dean Franklin, Bryony

    2016-01-01

    Introduction Intravenous medication is essential for many hospital inpatients. However, providing intravenous therapy is complex and errors are common. ‘Smart pumps’ incorporating dose error reduction software have been widely advocated to reduce error. However, little is known about their effect on patient safety, how they are used or their likely impact. This study will explore the landscape of intravenous medication infusion practices and errors in English hospitals and how smart pumps may relate to the prevalence of medication administration errors. Methods and analysis This is a mixed-methods study involving an observational quantitative point prevalence study to determine the frequency and types of errors that occur in the infusion of intravenous medication, and qualitative interviews with hospital staff to better understand infusion practices and the contexts in which errors occur. The study will involve 5 clinical areas (critical care, general medicine, general surgery, paediatrics and oncology), across 14 purposively sampled acute hospitals and 2 paediatric hospitals to cover a range of intravenous infusion practices. Data collectors will compare each infusion running at the time of data collection against the patient's medication orders to identify any discrepancies. The potential clinical importance of errors will be assessed. Quantitative data will be analysed descriptively; interviews will be analysed using thematic analysis. Ethics and dissemination Ethical approval has been obtained from an NHS Research Ethics Committee (14/SC/0290); local approvals will be sought from each participating organisation. Findings will be published in peer-reviewed journals and presented at conferences for academic and health professional audiences. Results will also be fed back to participating organisations to inform local policy, training and procurement. Aggregated findings will inform the debate on costs and benefits of the NHS investing in smart pump technology, and what other changes may need to be made to ensure effectiveness of such an investment. PMID:26940104

  18. An Optical Near-Infrared Study of Radio-loud Quasar Environments. I. Methods and Z = 1-2 Observations

    NASA Astrophysics Data System (ADS)

    Hall, Patrick B.; Green, Richard F.; Cohen, Martin

    1998-11-01

    We have conducted an optical/near-infrared study of the environments of radio-loud quasars (RLQs) at redshifts z = 0.6-2.0. In this paper we discuss the sample selection and observations for the z = 1.0-2.0 subsample and the reduction and cataloging techniques used. We discuss technical issues at some length, since few detailed descriptions of near-IR data reduction and multicolor object cataloging are currently available in single literature references. Our sample of 33 RLQs contains comparable numbers of flat and steep radio spectrum sources and sources of various radio morphologies and spans a similar range of Mabs and Prad, which allows us to disentangle dependence of environment on optical or radio luminosity from redshift evolution. We use the standard ``shift-and-stare'' method of creating deep mosaicked images in which the exposure time (and thus the rms noise) at each pixel is not constant across the mosaic. An unusual feature of our reduction procedure is the creation of images with constant rms noise from such mosaics. We adopted this procedure to enable use of the FOCAS detection package over almost the entire mosaic instead of only in the area of deepest observation where the rms noise is constant, thereby roughly doubling our areal coverage. We correct the object counts in our fields for stellar contamination using the SKY model of Cohen and compare the galaxy counts to those in random fields. Even after accounting for possible systematic magnitude offsets, we find a significant excess of K >~ 19 galaxies. Analysis and discussion of this excess population is presented by Hall & Green.

  19. 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...

  20. An Empirical Method of Detecting Time-Dependent Confounding: An Observational Study of Next Day Delirium in a Medical ICU

    PubMed Central

    Murphy, T.E.; Van Ness, P.H.; Araujo, K.L.B.; Pisani, M.A.

    2016-01-01

    Longitudinal research on older persons in the medical intensive care unit (MICU) is often complicated by the time-dependent confounding of concurrently administered interventions such as medications and intubation. Such temporal confounding can bias the respective longitudinal associations between concurrently administered treatments and a longitudinal outcome such as delirium. Although marginal structural models address time-dependent confounding, their application is non-trivial and preferably justified by empirical evidence. Using data from a longitudinal study of older persons in the MICU, we constructed a plausibility score from 0 10 where higher values indicate higher plausibility of time-dependent confounding of the association between a time-varying explanatory variable and an outcome. Based on longitudinal plots, measures of correlation, and longitudinal regression, the plausibility scores were compared to the differences in estimates obtained with non-weighted and marginal structural models of next day delirium. The plausibility scores of the three possible pairings of daily doses of fentanyl, haloperidol, and intubation indicated the following: low plausibility for haloperidol and intubation, moderate plausibility for fentanyl and haloperidol, and high plausibility for fentanyl and intubation. Comparing multivariable models of next day delirium with and without adjustment for time-dependent confounding, only intubations association changed substantively. In our observational study of older persons in the MICU, the plausibility scores were generally reflective of the observed differences between coefficients estimated from non-weighted and marginal structural models. PMID:26798411

  1. Asian couples in negotiation: a mixed-method observational study of cultural variations across five Asian regions.

    PubMed

    Lee, Wai-Yung; Nakamura, Shin-Ichi; Chung, Moon Ja; Chun, Young Ju; Fu, Meng; Liang, Shu-Chuan; Liu, Cui-Lian

    2013-09-01

    The purpose of this study was to explore variations in how contemporary couples from five different Asian regions negotiate disagreements. Video recordings of 50 couples (10 each from Japan, Korea, Mainland China, Taiwan, and Hong Kong) discussing unresolved disagreements provided raw data for quantitative and qualitative analyses. First, teams of coders from each region used a common protocol to make quantitative ratings of content themes and interaction patterns for couples from their own region. An interregional panel of investigators then performed in-depth qualitative reviews for half of these cases, noting cultural differences not only in observed patterns of couple behavior but also in their own perceptions of these patterns. Both quantitative and qualitative analyses revealed clear regional differences on dimensions such as overt negativity, demand-withdraw interaction, and collaboration. The qualitative results also provided a richer, more nuanced view of other (e.g., gender-linked) conflict management patterns that the quantitative analyses did not capture. Inconsistencies between qualitative and quantitative data and between the qualitative observations of investigators from different regions were most pronounced for couples from Korea and Japan, whose conflict styles were subtler and less direct than those of couples from the other regions. PMID:24033245

  2. A review of methods used in assessing non-serious adverse drug events in observational studies among type 2 diabetes mellitus patients

    PubMed Central

    2011-01-01

    Clinical drug trials are often conducted in selective patient populations, with relatively small numbers of patients, and a short duration of follow-up. Observational studies are therefore important for collecting additional information on adverse drug events (ADEs). Currently, there is no guidance regarding the methodology for measuring ADEs in such studies. Our aim was to evaluate whether the methodology used to assess non-serious ADEs in observational studies is adequate for detecting these ADEs, and for addressing limitations from clinical trials in patients with type 2 diabetes mellitus. We systematically searched MEDLINE and EMBASE for observational studies reporting non-serious ADEs (1999-2008). Methods to assess ADEs were classified as: 1) medical record review; 2) surveillance by health care professionals (HCP); 3) patient survey; 4) administrative data; 5) laboratory/clinical values; 6) not specified. We compared the range of ADEs identified, number and selection of patients included, and duration of follow-up. Out of 10,125 publications, 68 studies met our inclusion criteria. The most common methods were based on laboratory/clinical values (n = 25) and medical record review (n = 18). Solicited surveillance by HCP (n = 17) revealed the largest diversity of ADEs. Patient surveys (n = 15) focused mostly on hypoglycaemia and gastrointestinal ADEs, laboratory values based studies on hepatic and metabolic ADEs, and administrative database studies (n = 5) on cardiovascular ADEs. Four studies presented ADEs that were identified with the use of more than one method. The patient population was restricted to a lower risk population in 19% of the studies. Less than one third of the studies exceeded pre-approval regulatory requirements for sample size and duration of follow-up. We conclude that the current assessment of ADEs is hampered by the choice of methods. Many observational studies rely on methods that are inadequate for identifying all possible ADEs. Patient-reported outcomes and combinations of methods are underutilized. Furthermore, while observational studies often include unselective patient populations, many do not adequately address other limitations of pre-approval trials. This implies that these studies will not provide sufficient information about ADEs to clinicians and patients. Better protocols are needed on how to assess adverse drug events not only in clinical trials but also in observational studies. PMID:21958008

  3. ICRF Astrometric Observations - Methods of Observation and Reduction

    NASA Astrophysics Data System (ADS)

    Popescu, Petre; Nedelcu, Alin; Paraschiv, Petre; Badescu, Octavian

    2007-08-01

    In Bucharest and Belogradchik Astronomical Observatories were performed astrometric observations of ICRF defining and candidates radio-stars. In the first step we performed a modernization of the 60 cm telescope in Belogradchik - Bulgaria, in order to be able to reach 20-th magnitude. The paper describes the achievement of this task and the methods of observation and reduction of data. The results are stored in an astrometric data-base containing also the reference system of the quasars.

  4. Using observational methods in nursing research.

    PubMed

    Salmon, Jenny

    2015-07-01

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

  5. 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.

  6. A method to analyse observer disagreement in visual grading studies: example of assessed image quality in paediatric cerebral multidetector CT images.

    PubMed

    Ledenius, K; Svensson, E; Stlhammar, F; Wiklund, L-M; Thilander-Klang, A

    2010-07-01

    The purpose was to demonstrate a non-parametric statistical method that can identify and explain the components of observer disagreement in terms of systematic disagreement as well as additional individual variability, in visual grading studies. As an example, the method was applied to a study where the effect of reduced tube current on diagnostic image quality in paediatric cerebral multidetector CT (MDCT) images was investigated. Quantum noise, representing dose reductions equivalent to steps of 20 mA, was artificially added to the raw data of 25 retrospectively selected paediatric cerebral MDCT examinations. Three radiologists, blindly and randomly, assessed the resulting images from two different levels of the brain with regard to the reproduction of high- and low-contrast structures and overall image quality. Images from three patients were assessed twice for the analysis of intra-observer disagreement. The intra-observer disagreement in test-retest assessments could mainly be explained by a systematic change towards lower image quality the second time the image was reviewed. The inter-observer comparisons showed that the paediatric radiologist was more critical of the overall image quality, while the neuroradiologists were more critical of the reproduction of the basal ganglia. Differences between the radiologists regarding the extent to which they used the whole classification scale were also found. The statistical method used was able to identify and separately measure a presence of bias apart from additional individual variability within and between the radiologists which is, at the time of writing, not attainable by any other statistical approach suitable for paired, ordinal data. PMID:20335429

  7. A new method using medical ultrasound for measuring femoral anteversion (torsion): technique and reliability. An intra-observer and inter-observer study on dried bones from human adults.

    PubMed Central

    Upadhyay, S S; O'Neil, T; Burwell, R G; Moulton, A

    1987-01-01

    The purpose of this study was to evaluate an ultrasound method on dried femora to decide if it is sufficiently reliable to consider its application to living subjects in health and disease. It reports the application of a standard static image B-mode ultrasound scanner to measure femoral anteversion (strictly torsion) on dried bones. The method involves creating images of bony surface contours at both the upper and the lower ends of the femur placed in a water bath. The calculation of femoral torsion involves measuring the angular difference between a head-neck line at the upper end and a transcondylar line at the lower end of the femur. This approach, using the surface contour of the bone at the upper end of the femur, is similar to that used by Lange & Pitzen (1921) and differs from conventional ways of measuring anteversion in dried bones using a central femoral head-neck axis. It is shown that in ultrasound scanning of the upper end of the dried femur to measure femoral anteversion, the head-neck line must be at, or rostral to, the base of greater trochanter. The intra- and inter-observer reliability was assessed in 10 femora, each scanned ten times by two observers. It is shown that femoral torsion can be measured by the ultrasound method to an accuracy of +/- 2 degrees (95% confidence limits) without a significant difference between the observers. The ultrasound method is compared with a new mechanical method for creating surface contours at both ends of the femur and found not to be statistically different in 37 femora. Two real-time ultrasound methods reported by other workers for measuring femoral anteversion in dried bones are reviewed. It is suggested that in applying ultrasound to measure femoral anteversion in living subjects, the B-mode static image scanner is superior to the use of real-time scanners. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5 PMID:3332271

  8. 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; Lautamki, 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

  9. 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.

  10. 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.

  11. Ensemble transform sensitivity method for adaptive observations

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Xie, Yuanfu; Wang, Hongli; Chen, Dehui; Toth, Zoltan

    2016-01-01

    The Ensemble Transform (ET) method has been shown to be useful in providing guidance for adaptive observation deployment. It predicts forecast error variance reduction for each possible deployment using its corresponding transformation matrix in an ensemble subspace. In this paper, a new ET-based sensitivity (ETS) method, which calculates the gradient of forecast error variance reduction in terms of analysis error variance reduction, is proposed to specify regions for possible adaptive observations. ETS is a first order approximation of the ET; it requires just one calculation of a transformation matrix, increasing computational efficiency (60%-80% reduction in computational cost). An explicit mathematical formulation of the ETS gradient is derived and described. Both the ET and ETS methods are applied to the Hurricane Irene (2011) case and a heavy rainfall case for comparison. The numerical results imply that the sensitive areas estimated by the ETS and ET are similar. However, ETS is much more efficient, particularly when the resolution is higher and the number of ensemble members is larger.

  12. [Participant observation as data collection method in nursing research].

    PubMed

    Liukkonen, A; Astedt-Kurki, P

    1994-01-01

    Participant observation as data collection method in nursing research is explored in this article. The scientific basis of observation method comes from symbolic interactionism. Nature and epistemological starting points of the knowledge produced by observational method can vary depending on the purpose of the study. Participant observation is a process, which aims at scientific research through observer's presence in social situations. Fieldwork should be carefully prepared because the main problem in participant observation is observer's influence on phenomenon which is being studied. In the beginning of the field-work researcher tries to get a general view what happens in the situation. After the analysis the researcher can focus his observations according to his research problems and finally observe selectively. The data consists of record-keeping, descriptions and field-work note book. Participant observation is the most subjective observation method of data collection. By using triangulation a researcher can avoid his personal influence on results and make the validity of his study better. The researcher must take ethical issues into consideration when collecting data by participant observation. PMID:8054218

  13. Observational Studies: Matching or Regression?

    PubMed

    Brazauskas, Ruta; Logan, Brent R

    2016-03-01

    In observational studies with an aim of assessing treatment effect or comparing groups of patients, several approaches could be used. Often, baseline characteristics of patients may be imbalanced between groups, and adjustments are needed to account for this. It can be accomplished either via appropriate regression modeling or, alternatively, by conducting a matched pairs study. The latter is often chosen because it makes groups appear to be comparable. In this article we considered these 2 options in terms of their ability to detect a treatment effect in time-to-event studies. Our investigation shows that a Cox regression model applied to the entire cohort is often a more powerful tool in detecting treatment effect as compared with a matched study. Real data from a hematopoietic cell transplantation study is used as an example. PMID:26712591

  14. 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

  15. 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.

  16. Distracted Biking: An Observational Study.

    PubMed

    Wolfe, Elizabeth Suzanne; Arabian, Sandra Strack; Breeze, Janis L; Salzler, Matthew J

    2016-01-01

    Commuting via bicycle is a very popular mode of transportation in the Northeastern United States. Boston, MA, has seen a rapid increase in bicycle ridership over the past decade, which has raised concerns and awareness about bicycle safety. An emerging topic in this field is distracted bicycle riding. This study was conducted to provide descriptive data on the prevalence and type of distracted bicycling in Boston at different times of day. This was a cross-sectional study in which observers tallied bicyclists at 4 high traffic intersections in Boston during various peak commuting hours for 2 types of distractions: auditory (earbuds/phones in or on ears), and visual/tactile (electronic device or other object in hand). Nineteen hundred seventy-four bicyclists were observed and 615 (31.2%), 95% CI [29, 33%], were distracted. Of those observed, auditory distractions were the most common (N = 349; 17.7%), 95% CI [16, 19], p = .0003, followed by visual/tactile distractions (N = 266; 13.5%), 95% CI [12, 15]. The highest proportion (40.7%), 95% CI [35, 46], of distracted bicyclists was observed during the midday commute (between 13:30 and 15:00). Distracted bicycling is a prevalent safety concern in the city of Boston, as almost a third of all bicyclists exhibited distracted behavior. Education and public awareness campaigns should be designed to decrease distracted bicycling behaviors and promote bicycle safety in Boston. An awareness of the prevalence of distracted biking can be utilized to promote bicycle safety campaigns dedicated to decreasing distracted bicycling and to provide a baseline against which improvements can be measured. PMID:26953533

  17. 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.

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

    PubMed Central

    2012-01-01

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

  19. 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 ...

  20. 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.

  1. Observational studies: cohort and case-control studies.

    PubMed

    Song, Jae W; Chung, Kevin C

    2010-12-01

    Observational studies constitute an important category of study designs. To address some investigative questions in plastic surgery, randomized controlled trials are not always indicated or ethical to conduct. Instead, observational studies may be the next best method of addressing these types of questions. Well-designed observational studies have been shown to provide results similar to those of randomized controlled trials, challenging the belief that observational studies are second rate. Cohort studies and case-control studies are two primary types of observational studies that aid in evaluating associations between diseases and exposures. In this review article, the authors describe these study designs and methodologic issues, and provide examples from the plastic surgery literature. PMID:20697313

  2. Three-dimensional evaluation of postoperative swelling in treatment of zygomatic bone fractures using two different cooling therapy methods: a randomized, observer-blind, prospective study

    PubMed Central

    2013-01-01

    Background Surgical treatment and complications in patients with zygomatic bone fractures can lead to a significant degree of tissue trauma resulting in common postoperative symptoms and types of pain, facial swelling and functional impairment. Beneficial effects of local cold treatment on postoperative swelling, edema, pain, inflammation, and hemorrhage, as well as the reduction of metabolism, bleeding and hematomas, have been described. The aim of this study was to compare postoperative cooling therapy applied through the use of cooling compresses with the water-circulating cooling face mask manufactured by Hilotherm in terms of beneficial impact on postoperative facial swelling, pain, eye motility, diplopia, neurological complaints and patient satisfaction. Methods Forty-two patients were selected for treatment of unilateral zygomatic bone fractures and were divided randomly to one of two treatments: either a Hilotherm cooling face mask or conventional cooling compresses. Cooling was initiated as soon as possible after surgery until postoperative day 3 and was applied continuously for 12 hours daily. Facial swelling was quantified through a three-dimensional optical scanning technique. Furthermore, pain, neurological complaints, eye motility, diplopia and patient satisfaction were observed for each patient. Results Patients receiving a cooling therapy by Hilotherm demonstrated significantly less facial swelling, less pain, reduced limitation of eye motility and diplopia, fewer neurological complaints and were more satisfied compared to patients receiving conventional cooling therapy. Conclusions Hilotherapy is more efficient in managing postoperative swelling and pain after treatment of unilateral zygomatic bone fractures than conventional cooling. Trial registration German Clinical Trials Register ID: DRKS00004846 PMID:23895539

  3. Basic Caenorhabditis elegans methods: synchronization and observation.

    PubMed

    Porta-de-la-Riva, Montserrat; Fontrodona, Laura; Villanueva, Alberto; Cern, Julin

    2012-01-01

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

  4. Study of swelling behavior in ArF resist during development by the QCM method (3): observations of swelling layer elastic modulus

    NASA Astrophysics Data System (ADS)

    Sekiguchi, Atsushi

    2013-03-01

    The QCM method allows measurements of impedance, an index of swelling layer viscosity in a photoresist during development. While impedance is sometimes used as a qualitative index of change in the viscosity of the swelling layer, it has to date not been used quantitatively, for data analysis. We explored a method for converting impedance values to elastic modulus (Pa), a coefficient expressing viscosity. Applying this method, we compared changes in the viscosity of the swelling layer in an ArF resist generated during development in a TMAH developing solution and in a TBAH developing solution. This paper reports the results of this comparative study.

  5. Science Studies from Archived Observations

    NASA Astrophysics Data System (ADS)

    Armstrong, T. P.; Manweiler, J. W.; Patterson, J. D.

    2008-12-01

    Goals for spaceflight investigations include the discovery and characterization of physical features of the in- situ and remote environment. Abundant successes of flight investigations are easily documented. Prudent scientific practice dictates that to the maximum extent possible, observations should be well-characterized, reliably catalogued, and knowledgeably interpreted. This is especially true of data sets used in the publication of results in the reviewed literature. Typical scientific standards include making primary data numbers available to other investigators for replicated study. While NASA's contracts with investigators have required that data be submitted to agency official archives, the details, completeness (especially of ancillary and metadata) and forms differ from investigation to investigation and project to project. After several generations of improvements and refinements, modern computing and communications technology makes it possible to link multiple data sets at multiple locations through a unified data model. Virtual Observatories provide the overall organizational structures and SPASE-compliant XML defines the data granules that can be located. Proofs of the feasibility and value of this latest approach remain to be seen, but its ultimate goal of improving archival research using flight-derived data sets appears to depend on user acceptance and efficient use of the VxO resources. Criteria based on the authors experience in science derived from archival sources follow: 1. Interfaces and tools must be easy to learn, easy to use, and reliable. 2. Data numbers must be promptly downloadable in plain text. 3. Data must be available in or readily converted to physical units using calibrations and algorithms easily traceable as part of the search. Knowledge about (or heritage of) specific data items present in the science literature must be associated with the search for that item. 4. Data items must be trustworthy, having quoted uncertainties and available history where versioning has occurred. While these are challenging criteria to meet-especially in succinct form-the use of archival data for valid science publication requires that these criteria are achieved. The full presentation will illustrate and expand on these criteria.

  6. 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.

  7. Card Studies for Observational Research in Practice

    PubMed Central

    Westfall, John M.; Zittleman, Linda; Staton, Elizabeth W.; Parnes, Bennett; Smith, Peter C.; Niebauer, Linda J.; Fernald, Douglas H.; Quintela, Javan; Van Vorst, Rebecca F.; Dickinson, L. Miriam; Pace, Wilson D.

    2011-01-01

    PURPOSE Observational studies that collect patient-level survey data at the point-of-care are often called card studies. Card studies have been used to describe clinical problems, management, and outcomes in primary care for more than 30 years. In this article we describe 2 types of card studies and the methods for conducting them. METHODS We undertook a descriptive review of card studies conducted in 3 Colorado practice-based research networks and several other networks throughout the United States. We summarized experiences of the State Networks of Colorado Ambulatory Practices and Partners (SNOCAP). RESULTS Card studies can be designed to study specific conditions or care (clinicians complete a card when they encounter patients who meet inclusion criteria) and to determine trends and prevalence of conditions (clinicians complete a card on all patients seen during a period). Data can be collected from clinicians and patients and can be linked. CONCLUSIONS Card studies provide cross-sectional descriptive data about clinical care, knowledge and behavior, perception of care, and prevalence of conditions. Card studies remain a robust method for describing primary care. PMID:21242563

  8. Novel sample preparation method of polymer emulsion for SEM observation.

    PubMed

    Xu, Jing; Hou, Zhaosheng; Li, Tianduo

    2007-10-01

    The aim of this study was to design a simple and reliable method for obtaining the detailed information about the average size, size distribution, and the surface morphology of particles with variation of the sample preparation of a polymer emulsion. In this work, the characteristic features of the particles of rosin size with high viscosity were first described by scanning electron microscopy (SEM). The morphologies of polymer emulsion of solid lipid nanoparticles and of the microspheres were observed. The advantage of the method is that not only the true size and shape of emulsion particles can be shown, but the problem of high-viscosity emulsion that prevents there study with SEM is solved. Using this new method, the micromorphology and size distribution of the emulsion particles with different viscosities have been clearly observed. PMID:17576124

  9. 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

  10. Methods of Studying Persons.

    ERIC Educational Resources Information Center

    Heinemann, Allen W.; Shontz, Franklin C.

    1985-01-01

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

  11. A Comparison of Methods for Ocean Reconstruction from Sparse Observations

    NASA Astrophysics Data System (ADS)

    Streletz, G. J.; Kronenberger, M.; Weber, C.; Gebbie, G.; Hagen, H.; Garth, C.; Hamann, B.; Kreylos, O.; Kellogg, L. H.; Spero, H. J.

    2014-12-01

    We present a comparison of two methods for developing reconstructions of oceanic scalar property fields from sparse scattered observations. Observed data from deep sea core samples provide valuable information regarding the properties of oceans in the past. However, because the locations of sample sites are distributed on the ocean floor in a sparse and irregular manner, developing a global ocean reconstruction is a difficult task. Our methods include a flow-based and a moving least squares -based approximation method. The flow-based method augments the process of interpolating or approximating scattered scalar data by incorporating known flow information. The scheme exploits this additional knowledge to define a non-Euclidean distance measure between points in the spatial domain. This distance measure is used to create a reconstruction of the desired scalar field on the spatial domain. The resulting reconstruction thus incorporates information from both the scattered samples and the known flow field. The second method does not assume a known flow field, but rather works solely with the observed scattered samples. It is based on a modification of the moving least squares approach, a weighted least squares approximation method that blends local approximations into a global result. The modifications target the selection of data used for these local approximations and the construction of the weighting function. The definition of distance used in the weighting function is crucial for this method, so we use a machine learning approach to determine a set of near-optimal parameters for the weighting. We have implemented both of the reconstruction methods and have tested them using several sparse oceanographic datasets. Based upon these studies, we discuss the advantages and disadvantages of each method and suggest possible ways to combine aspects of both methods in order to achieve an overall high-quality reconstruction.

  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. 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.

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

    PubMed Central

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

    2013-01-01

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

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

    ERIC Educational Resources Information Center

    Nadler, Cy B.; Roberts, Mark W.

    2013-01-01

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

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

    ERIC Educational Resources Information Center

    Nadler, Cy B.; Roberts, Mark W.

    2013-01-01

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

  17. A new method for astrometric observations of asteroids

    NASA Technical Reports Server (NTRS)

    Pauwels, Thierry

    1992-01-01

    In this paper we propose a new method for photographic astrometric observations of asteroids. We discuss its advantages and disadvantages and compare them to the advantages and disadvantages of the classical photographic methods. The new method is best suited for observations on a spot where no CCD cameras, blink or stereo comparators are available and when a fast detection of unknown objects is required.

  18. An Observational Assessment Method for Aging Laboratory Rats

    PubMed Central

    Phillips, Pamela M; Jarema, Kimberly A; Kurtz, David M; MacPhail, Robert C

    2010-01-01

    The rapid growth of the aging human population highlights the need for laboratory animal models to study the basic biologic processes of aging and susceptibility to disease, drugs, and environmental pollutants. Methods are needed to evaluate the health of aging animals over time, particularly methods for efficiently monitoring large research colonies. Here we describe an observational assessment method that scores appearance, posture, mobility, and muscle tone on a 5-point scale that can be completed in about 1 min. A score of 1 indicates no deterioration, whereas a score of 5 indicates severe deterioration. Tests were applied to male Brown Norway rats between 12 and 36 mo of age (n = 32). The rats were participating concurrently in experiments on the behavioral effects of intermittent exposure (approximately every 4 mo) to short-acting environmental chemicals. Results demonstrated that aging-related signs of deterioration did not appear before 18 mo of age. Assessment scores and variability then increased with age. Body weights increased until approximately 24 mo, then remained stable, but decreased after 31 mo for the few remaining rats. The incidence of death increased slightly from 20 to 28 mo of age and then rose sharply; median survival age was approximately 30 mo, with a maximum of 36 mo. The results indicate that our observational assessment method supports efficient monitoring of the health of aging rats and may be useful in studies on susceptibility to diseases, drugs, and toxicants during old age. PMID:21205442

  19. 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.

  20. Observation impact analysis methods for storm surge forecasting systems

    NASA Astrophysics Data System (ADS)

    Verlaan, Martin; Sumihar, Julius

    2016-02-01

    This paper presents a simple method for estimating the impact of assimilating individual or group of observations on forecast accuracy improvement. This method is derived from the nsemble-based observation impact analysis method of Liu and Kalnay (Q J R Meteorol Soc 134:1327-1335, 2008). The method described here is different in two ways from their method. Firstly, it uses a quadratic function of model-minus-observation residuals as a measure of forecast accuracy, instead of model-minus-analysis. Secondly, it simply makes use of time series of observations and the corresponding model output generated without data assimilation. These time series are usually available in an operational database. Hence, it is simple to implement. It can be used before any data assimilation is implemented. Therefore, it is useful as a design tool of a data assimilation system, namely for selecting which observations to assimilate. The method can also be used as a diagnostic tool, for example, to assess if all observation contributes positively to the accuracy improvement. The method is applicable for systems with stationary error process and fixed observing network. Using twin experiments with a simple one-dimensional advection model, the method is shown to work perfectly in an idealized situation. The method is used to evaluate the observation impact in the operational storm surge forecasting system based on the Dutch Continental Shelf Model version 5 (DCSMv5).

  1. 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; Gtzsche, 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

  2. 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 optionbut 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 randomMCAR), multiple imputation (assuming missing at randomMAR) and Heckman selection model (assuming missing not at randomMNAR). 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

  3. 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)

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

    NASA Astrophysics Data System (ADS)

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

    2007-11-01

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

  5. [Methods for studying eugenol].

    PubMed

    Shabalina, A E; Kirichek, A V; Simonov, E A

    2009-01-01

    A steady tendency toward the extensive use of phytogenous medicinal products well apparent in the recent years involves dental materials. Over one third of the dentistry products contain eugenol, the main component of the clove essential oil. This study is focused on the development of a method for the detection and quantitative measurement ofeugenol in a variety of stomatological products, includling filling materials, and other preparations. The samples for analysis were prepared taking into account physical and chemical properties of the substance of interest, such as high partial pressure over the liquid phase. We investigated the equilibrium vapour phase by capillary gas chromatography with the use of a mass-spectral detector. A method for the detection and quantitative assay of eugenol in dental materials and-filling agents was developed. Its sensitivity limit is 10 ng/ml for liquid samples and 25 mcg/g for solid ones. Metrologic characteristics of the method make it suitable for the detection of eugenol in dental fillings after their long-term contact with biological tissues. PMID:19507738

  6. Using a Harmonic Scalpel "Drilling and Clamping" Method to Implement Zero Ischemic Robotic-assisted Partial Nephrectomy: An Observation Case Report Study.

    PubMed

    Hou, Chen-Pang; Lin, Yu-Hsiang; Hsu, Yu-Chao; Chen, Chien-Lun; Chang, Phei-Lang; Tsui, Ke-Hung

    2016-01-01

    Robot-assisted partial nephrectomy (RAPN) has gradually become a popular minimally invasive nephron-sparing surgical option for small renal tumors. Ischemic injury should be minimized because it impacts renal function outcomes following partial nephrectomy. Herein, the authors detail the technique and present initial perioperative outcomes of our novel harmonic scalpel "drilling and clamping" method to implement zero-ischemic RAPN. The authors prospectively collected baseline and perioperative data of patients who underwent zero ischemic RAPN performed by our harmonic scalpel "drilling and clamping" method. From April 2012 to December 2014, a total of 19 consecutive zero ischemic RAPN procedures were performed by a single surgeon. For 18 of the 19 patients, RAPN using our harmonic scalpel "Drilling and Clamping" method was successfully completed without the need for hilar clamping. The median tumor size was 3.4?cm (range: 1.8-6.2); operative time was 3.2 hours (range: 1.9-4.5); blood loss was 100?mL (range: 30-950); and postoperative hospital stay was 4 days (3-26). One patient required intraoperative blood transfusion. Two patients had intra or postoperative complications: 1 was converted to traditional laparotomy because of massive bleeding, whereas another had postoperative stress ulcer. Pathology confirmed renal cell carcinoma in 13 patients (63.2%), angiomyolipoma in 6 patients: (31.5%), and oncocytoma in 1 patient (5.3%). Mean pre- and postoperative serum creatinine (0.82?mg/dL and 0.85?mg/dL, respectively), estimated glomerular filtration rate (84.12 and 82.18, respectively), and hemoglobin (13.27?g/dL and 12.71?g/dL, respectively) were comparable. The authors present a novel zero-ischemic technique for RAPN. They believe that this technique is feasible and reproducible. PMID:26817867

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

    PubMed

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

    2016-01-01

    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

  8. 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

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

    ERIC Educational Resources Information Center

    Notgrass, Patty J.

    2012-01-01

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

  10. Qualitative research: Observational methods in health care settings.

    PubMed Central

    Mays, N.; Pope, C.

    1995-01-01

    Clinicians used to observing individual patients, and epidemiologists trained to observe the course of disease, may be forgiven for misunderstanding the term observational method as used in qualitative research. In contrast to the clinician or epidemiologist, the qualitative researcher systematically watches people and events to find out about behaviours and interactions in natural settings. Observation, in this sense, epitomises the idea of the researcher as the research instrument. It involves "going into the field"--describing and analysing what has been seen. In health care settings this method has been insightful and illuminating, but it is not without pitfalls for the unprepared researcher. Images p183-a PMID:7613435

  11. Compositing radar reflectivity observations with an inverse method

    NASA Astrophysics Data System (ADS)

    Roca-Sancho, Jordi; Berenguer, Marc; Sempere-Torres, Daniel

    2013-04-01

    Quantitative Precipitation Estimation (QPE) has been one of the main applications of weather radars since its early stages. Nowadays, many advances have improved such estimates and radar networks have been deployed in many countries. In parallel, uncertainty in radar QPE has become a subject of interest by itself because of its significant role in the quality of estimates. When several radars cover the same area, some sources of uncertainty (e.g. path attenuation by intense precipitation, beam blockage or beam broadening), can be dealt using information from the least-affected radars instead of only reproducing a single radar approach in each one. So far, composites of radar observations are carried out through simple criteria (by picking the closest observation, the maximum value) or quality indices -that need a priori definition of quality descriptors. This study proposes an alternative methodology to retrieve the 3-dimensional reflectivity field most compatible with the measurements from the different radars of the network. With this aim, the methodology uses a model that simulates the radar sampling of the atmosphere. The model settings consider the specific features of each radar such as the location, hardware parameters (frequency, beam width, pulse length) and scanning strategy. The methodology follows the concept of an inverse method based on the minimization of a cost function that penalizes discrepancies between the simulated and actual observations for each radar of the network. It is worth noting that for radar at attenuating wavelengths, the proposed methodology implicitly corrects the effect of attenuation due to intense rainfall. The methodology has been applied on the network of C-band radars in the vicinity of Barcelona, Spain. The retrievals have been obtained for a 12 hours of rainfall with reflectivity observations of two radars; observations from a third independent radar have been used for verification at different heights. Conventional techniques have been also applied to compare its results with the ones of the proposed method. We analyzed some characteristics such as the vertical structure or the performance in attenuated regions. Different statistics have been computed to quantitatively assess the performance of the different methods; also, the spatial structure of the retrieved fields has been analyzed.

  12. 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...

  13. 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.

  14. 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".

  15. 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...

  16. 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.

  17. Methods of Studying Persons.

    ERIC Educational Resources Information Center

    Heinemann, Allen W.; Shontz, Franklin C.

    Conventional research strategies typically emphasize behavior-determining tendencies so strongly that the person as a whole is ignored. Research strategies for studying whole persons focus on symbolic structures, formulate specific questions in advance, study persons one at a time, use individualized measures, and regard participants as expert

  18. 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

  19. 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.

  20. Embedding clinical interventions into observational studies.

    PubMed

    Newman, Anne B; Avils-Santa, M Larissa; Anderson, Garnet; Heiss, Gerardo; Howard, Wm James; Krucoff, Mitchell; Kuller, Lewis H; Lewis, Cora E; Robinson, Jennifer G; Taylor, Herman; Trevio, 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

  1. Workplace Education Initiative: Case Studies and Observations.

    ERIC Educational Resources Information Center

    Astrein, Bruce; And Others

    Seven workplace education projects funded in the first year of the Massachusetts Workplace Education Initiative are reported. This report includes both general observations and specific information in case studies of the projects. Overall information is provided on students served, the importance of partnerships, the emphasis on

  2. 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.

  3. 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.

  4. Observer ratings of neighborhoods: comparison of two methods

    PubMed Central

    2013-01-01

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

  5. 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.

  6. 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.

  7. Vehicle Motion Control Method Using Yaw-moment Observer and Lateral Force Observer for Electric Vehicle

    NASA Astrophysics Data System (ADS)

    Yamauchi, Yuya; Fujimoto, Hiroshi

    The motion stability of a vehicle depends on yaw-rate and side-slip angle. These two variables affect each other, and therefore, we performed decoupling control of yaw-rate and side-slip angle of an electric vehicle (EV) with active steering and torque difference between left and right in-wheel motors. However the robustness of decoupling control is fragile for road condition. Hence, we propose lateral force observer (LFO) that is highly robust to variations in the cornering stiffness. LFO and yaw-moment observer (YMO) are used in an EV with an active steering and two in-wheel motors. In this paper, we compare the robustness of the proposed method and that of the decoupling-control method by means of an experiment. The results show that the proposed method delivers a better performance than that of the conventional method.

  8. Mobile vehicle road and weather observation quality check methods

    NASA Astrophysics Data System (ADS)

    Koller, Daniel Raymond

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

  9. Displacement Monitoring and Sensitivity Analysis in the Observational Method

    NASA Astrophysics Data System (ADS)

    Górska, Karolina; Muszyński, Zbigniew; Rybak, Jarosław

    2013-09-01

    This work discusses the fundamentals of designing deep excavation support by means of observational method. The effective tools for optimum designing with the use of the observational method are both inclinometric and geodetic monitoring, which provide data for the systematically updated calibration of the numerical computational model. The analysis included methods for selecting data for the design (by choosing the basic random variables), as well as methods for an on-going verification of the results of numeric calculations (e.g., MES) by way of measuring the structure displacement using geodetic and inclinometric techniques. The presented example shows the sensitivity analysis of the calculation model for a cantilever wall in non-cohesive soil; that analysis makes it possible to select the data to be later subject to calibration. The paper presents the results of measurements of a sheet pile wall displacement, carried out by means of inclinometric method and, simultaneously, two geodetic methods, successively with the deepening of the excavation. This work includes also critical comments regarding the usefulness of the obtained data, as well as practical aspects of taking measurement in the conditions of on-going construction works.

  10. 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.

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

    PubMed

    Zafar, Fahad; Yesha, Yaacov; Badano, Aldo

    2014-09-22

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

  12. 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...

  13. A novel observer design method for neural mass models

    NASA Astrophysics Data System (ADS)

    Liu, Xian; Miao, Dong-Kai; Gao, Qing; Xu, Shi-Yun

    2015-09-01

    Neural mass models can simulate the generation of electroencephalography (EEG) signals with different rhythms, and therefore the observation of the states of these models plays a significant role in brain research. The structure of neural mass models is special in that they can be expressed as Lurie systems. The developed techniques in Lurie system theory are applicable to these models. We here provide a new observer design method for neural mass models by transforming these models and the corresponding error systems into nonlinear systems with Lurie form. The purpose is to establish appropriate conditions which ensure the convergence of the estimation error. The effectiveness of the proposed method is illustrated by numerical simulations. Project supported by the National Natural Science Foundation of China (Grant Nos. 61473245, 61004050, and 51207144).

  14. Lagrangian methods for observation of intrathermocline eddies in ocean

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  15. 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.

  16. Double-observer line transect methods: levels of independence.

    PubMed

    Buckland, Stephen T; Laake, Jeffrey L; Borchers, David L

    2010-03-01

    Double-observer line transect methods are becoming increasingly widespread, especially for the estimation of marine mammal abundance from aerial and shipboard surveys when detection of animals on the line is uncertain. The resulting data supplement conventional distance sampling data with two-sample mark-recapture data. Like conventional mark-recapture data, these have inherent problems for estimating abundance in the presence of heterogeneity. Unlike conventional mark-recapture methods, line transect methods use knowledge of the distribution of a covariate, which affects detection probability (namely, distance from the transect line) in inference. This knowledge can be used to diagnose unmodeled heterogeneity in the mark-recapture component of the data. By modeling the covariance in detection probabilities with distance, we show how the estimation problem can be formulated in terms of different levels of independence. At one extreme, full independence is assumed, as in the Petersen estimator (which does not use distance data); at the other extreme, independence only occurs in the limit as detection probability tends to one. Between the two extremes, there is a range of models, including those currently in common use, which have intermediate levels of independence. We show how this framework can be used to provide more reliable analysis of double-observer line transect data. We test the methods by simulation, and by analysis of a dataset for which true abundance is known. We illustrate the approach through analysis of minke whale sightings data from the North Sea and adjacent waters. PMID:19432793

  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. 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

  19. Study of ENSO Using Satellite Observations

    NASA Astrophysics Data System (ADS)

    Kao, H.; Lagerloef, G. S.

    2013-12-01

    Observations within the last 1 to 1.5 decades indicate that the El Nio warm sea surface temperature (SST) anomalies have peaked more often in the central Pacific than in the eastern Pacific. The advection of the eastern edge of western Pacific warm pool (WPWP) plays an important role modulating the SST in the central Pacific, and satellite observations provide high-resolution information to understand the dynamics in this area. The Aquarius satellite data resolves much more detailed structures of the salinity front (SF) along the eastern edge of WPWP than the in situ observations (i.e. Argo). Together with zonal currents from Ocean Surface Current Analyses Real-Time product (OSCAR), we calculate the advection of the SF at the equator, which is important for three reasons: First, the advection of the SF affects formation the barrier layer (BL), which can further influence the behavior of ENSO. Second, the east-west SF migration is a prominent feature of ENSO variability. For example, during the 2011 La Nia, the salinity front was advected westward, resulting in much higher salinity in the western Pacific compared to the neutral year in 2012. Third, we can analyze how the ocean compensates for the large vertical net freshwater flux (~3 m yr-1) into the warm pool region using simple salt budget analysis. During the boreal fall, Aquarius reveals the strong SF in line with the north-south zonal bounds of the whole Pacific ITCZ rain band centered at about 8-10N, which is also aligned with boundaries between the zonal equatorial current and counter current. At the same time, the thick barrier layers underneath the ITCZ are also observed. In this study, we apply the first two+ years (25 August 2011 - present) of Aquarius data to describe the correlations among the SF, surface currents, precipitation and the BL in the whole tropical Pacific basin, and discuss findings in the context of ENSO prediction and model comparisons.

  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. Detection of single cells: an observer study

    NASA Astrophysics Data System (ADS)

    Ford, Nancy L.; Pollmann, Steven I.; Habets, Damiaan F.; Holdsworth, David W.

    2004-05-01

    Recent advances in imaging technology have brought high-resolution imaging into the practical laboratory setting. As a result, there has been increasing interest in imaging molecular and cellular processes in live animals. To image a single cell, a contrast medium, radiolabel or metallic label is inserted into the cell, which is then introduced into the animal. How well the cell is visualized depends upon the contrast-to-noise ratio between the cell and the surrounding tissues, along with other factors such as the amount of signal present in each voxel of the image and the size of the contrast-enhanced region, as compared with the image dimensions. Through observer studies, we are investigating the detectability of a single cell in an image. We synthesized uniform volumetric datasets with Gaussian distributed noise and altered a single voxel to reflect one of 5 different contrast-to-noise ratios (CNRs) to create the cell-labeled image. The maximum intensity projection was acquired through each image. For each dataset, a high-contrast signal-only image was flanked on either side by the noise image and the cell-labeled image to create an image triplet. The observer task was to locate the cell-labeled image in a two-alternative forced choice study.

  2. Development of acoustic observation method for seafloor hydrothermal flows

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  3. The Home Observation Assessment Method (HOAM): Real-Time Naturalistic Observation of Families in Their Homes.

    ERIC Educational Resources Information Center

    Steinglass, Peter

    The vast bulk of psychosocial research data about the family are derived from two basic sources: self-report, retrospective data obtained by questionnaires or interviews; and direct observations of behavior occurring in a laboratory or treatment setting. Despite an emerging enthusiasm for the notion of studying behavior in its natural environment

  4. 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.

  5. The Effects of Integrating Technology, Observation and Writing into a Teacher Education Method Course

    ERIC Educational Resources Information Center

    Jang, Syh-Jong

    2008-01-01

    The purpose of this study was to integrate asynchronous learning technology with teaching strategies on observation and writing into a teacher education method course. The research questions were to explore the effects of the innovative teaching method and to compare it with the traditional teaching method. There were 134 preservice teachers

  6. STRengthening Analytical Thinking for Observational Studies: the STRATOS initiative

    PubMed Central

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

    2014-01-01

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

  7. Observational studies of drizzle in marine stratocumulus

    NASA Astrophysics Data System (ADS)

    Rossiter, Dione Lee

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

  8. Social Studies: Issues and Methods.

    ERIC Educational Resources Information Center

    Dynneson, Thomas L.

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

  9. 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.

  10. 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.

  11. 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.

  12. Comparison of Observational Methods and Their Relation to Ratings of Engagement in Young Children

    ERIC Educational Resources Information Center

    Wood, Brenna K.; Hojnoski, Robin L.; Laracy, Seth D.; Olson, Christopher L.

    2016-01-01

    Although, collectively, results of earlier direct observation studies suggest momentary time sampling (MTS) may offer certain technical advantages over whole-interval (WIR) and partial-interval (PIR) recording, no study has compared these methods for measuring engagement in young children in naturalistic environments. This study compared direct

  13. Comparison of Observational Methods and Their Relation to Ratings of Engagement in Young Children

    ERIC Educational Resources Information Center

    Wood, Brenna K.; Hojnoski, Robin L.; Laracy, Seth D.; Olson, Christopher L.

    2016-01-01

    Although, collectively, results of earlier direct observation studies suggest momentary time sampling (MTS) may offer certain technical advantages over whole-interval (WIR) and partial-interval (PIR) recording, no study has compared these methods for measuring engagement in young children in naturalistic environments. This study compared direct…

  14. 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)…

  15. 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)

  16. 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.

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  18. The Observation and Study of Shallow-contact Binary Systems

    NASA Astrophysics Data System (ADS)

    He, J.-J.; Qian, S.-B.

    2009-08-01

    The shallow-contact binary is a system with low degree of contact, short orbital period and late spectral type. It is a bridge to connect detached binary system, semi-detached binary system with contact binary system. The study of the common convective envelope (CCE) of shallow-contact binary system is important to know how the CCE comes into being because the CCE of shallow-contact binary system is very thin. We have observed several systems (e.g. RV Psc, AW Vir, II CMa, AD Cnc). And we study their basic parameters using W-D method. The period studies will help us to understand their structure and evolution.

  19. Complicated Intra-Abdominal Infections Observational European study (CIAO Study).

    PubMed

    Sartelli, Massimo; Catena, Fausto; Ansaloni, Luca; Lazzareschi, Daniel V; Taviloglu, Korhan; Van Goor, Harry; Viale, Pierluigi; Leppaniemi, Ari; De Werra, Carlo

    2011-01-01

    Complicated intra-abdominal infections are frequently associated with poor prognoses and high morbidity and mortality rates.Despite advances in diagnosis, surgery, and antimicrobial therapy, mortality rates associated with complicated intra-abdominal infections remain exceedingly high.In order to describe the clinical, microbiological, and management-related profiles of both community-acquired and healthcare-acquired complicated intra-abdominal infections (IAIs), the World Society of Emergency Surgery (WSES), in collaboration with the Surgical Infections Society of Europe (SIS-E) and other prominent European surgical societies, has designed the CIAO study.The CIAO study is a multicenter, observational study and will be carried out in various surgical departments throughout Europe. The study will include patients undergoing surgery or interventional drainage for complicated IAI. PMID:22152549

  20. Complicated Intra-Abdominal Infections Observational European study (CIAO Study)

    PubMed Central

    2011-01-01

    Complicated intra-abdominal infections are frequently associated with poor prognoses and high morbidity and mortality rates. Despite advances in diagnosis, surgery, and antimicrobial therapy, mortality rates associated with complicated intra-abdominal infections remain exceedingly high. In order to describe the clinical, microbiological, and management-related profiles of both community-acquired and healthcare-acquired complicated intra-abdominal infections (IAIs), the World Society of Emergency Surgery (WSES), in collaboration with the Surgical Infections Society of Europe (SIS-E) and other prominent European surgical societies, has designed the CIAO study. The CIAO study is a multicenter, observational study and will be carried out in various surgical departments throughout Europe. The study will include patients undergoing surgery or interventional drainage for complicated IAI. PMID:22152549

  1. Concentrated Study: A Pedagogic Innovation Observed.

    ERIC Educational Resources Information Center

    Parlett, Malcolm R.; King, John G.

    The Concentrated Study (COS) program at the Massachusetts Institute of Technology (MIT) is fulltime study of a single subject for a short period with no concurrent academic commitments. Chapter one describes the first trial of COS at MIT. Emphasis is placed on planning and preparation, description of course work and activities, and evaluation.

  2. 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.

  3. Multispectral satellite observations for arid land studies

    NASA Technical Reports Server (NTRS)

    Choudhury, Bhaskar J.

    1992-01-01

    Multispectral satellite data when properly calibrated and standardized can be used synergistically for a quantitative analysis of processes and surface characteristics, and for quantifying land surface change. Relationships among multispectral satellite data (visible reflectance, surface temperature and polarization difference of microwave emission at 37 GHz frequency) have been used to develop hypotheses concerning the relative sensitivity of these data to varied land surface characteristics, which needs to be verified by field observations. Radiative transfer models have also been developed to understand these multispectral data. Interannual variations of visible reflectance and polarization difference for the period 1982-1986 over the Sahel and the Sudan zones of Africa show a lagged response with respect to the rainfall deficit during recovery from drought, which needs to be understood in terms of biophysical parameters.

  4. 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.

  5. What Is Popular Music Studies? Some Observations

    ERIC Educational Resources Information Center

    Cloonan, Martin

    2005-01-01

    Popular Music Studies (PMS) is now taught in over 20 higher education institutions (HEIs) in the UK and numerous others across the world. This article outlines the constituent parts of PMS in the UK and questions its status as a discipline in its own right. It concludes by arguing that, having established itself, PMS will need to deal with two key

  6. 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.

  7. Dietary assessment methods in epidemiologic studies

    PubMed Central

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

    2014-01-01

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

  8. Improving Method-in-Use through Classroom Observation

    ERIC Educational Resources Information Center

    Nunn, Roger

    2011-01-01

    Method-in-use (Nunn, Describing classroom interaction in intercultural curricular research and development, University of Reading, 1996, International Review of Applied Linguistics in Language Teaching 37: 23-42, 1999) is a description of the method actually being enacted through classroom interaction in a particular context. The description is…

  9. Environmental SEM and dye penetration observation on resin-tooth interface using different light curing method.

    PubMed

    Yoshikawa, Takako; Morigami, Makoto; Sadr, Alireza; Tagami, Junji

    2016-01-01

    The aim of this study was the effects of different light curing methods on marginal sealing and resin composite adaptation to the cavity wall using the dye penetration test and environmental scanning electron microscope (SEM) observations. Cylindrical cavities were prepared on cervical regions. The teeth were restored with Clearfil Liner Bond 2 V adhesive and filled with Clearfil Photo Bright or Palfique Estelite resin composites. These resins were cured with a conventional light-curing method or a slow-start curing method. After thermal cycling, the specimens were subjected to the dye penetration test to evaluate marginal sealing and adaptation of the resin composites to the cavity walls. These resin-tooth interfaces were then observed using environmental SEM. The light-cured resin composite, which exhibited increased contrast ratios during polymerization, suggests high compensation for polymerization stress using the slow-start curing method. There was a high correlation between dye penetration test and environmental SEM observation. PMID:26830828

  10. Clinical observations and systematic studies of autogynephilia.

    PubMed

    Blanchard, R

    1991-01-01

    The term autogynephilia denotes a male's paraphilic tendency to be sexually aroused by the thought or image of himself as a woman. This term subsumes transvestism as well as erotic ideas or situations in which women's garments per se play a small role or none at all. This review article presents clinical examples of the lesser known types of autogynephilia (i.e., those in which the element of cross-dressing is secondary or entirely absent), sketches earlier attempts to label and conceptualize these phenomena, summarizes recent quantitative studies exploring the relationships between autogynephilia and other psychosexual variables (e.g., heterosexual attraction), and speculates on the etiology of autogynephilia and its relationship to transsexualism. It is concluded that the concept of autogynephilia is needed to fill a gap in our current battery of concepts and categories for thinking about gender identity disorders. PMID:1815090

  11. 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.

  12. 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

  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. 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.

  15. 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.

  16. On the Merits of Direct Observation of Periodical Usage: An Empirical Study.

    ERIC Educational Resources Information Center

    Bustion, Marifran; And Others

    1992-01-01

    An auxiliary study of the direct observation method for counting periodical usage in Evans Library at Texas A&M University found that student observations contain substantial error and that aggregation problems and cost issues are fundamental constraints to this method. Concludes direct observation may be useful in calibrating the results of other

  17. Factors affecting recruitment to an observational multicentre palliative care study

    PubMed Central

    Stone, Patrick C; Gwilliam, Bridget; Keeley, Vaughan; Todd, Chris; Kelly, Laura C; Barclay, Stephen

    2013-01-01

    Objectives To identify those factors which adversely affected recruitment to a large multicentre palliative care study. Methods Patient accrual to a multicentre, observational, palliative care study was monitored at three critical junctures in the research process. (1) Eligibilitydid the patient fulfil the study entry criteria? (2) Accessibilitywas it possible to access the patient to be able to inform them about the study? (3) Consentdid the patient agree to participate in the study? The reasons why patients were ineligible, inaccessible or refused consent were recorded. Results 12?412 consecutive referrals to participating clinical services were screened for study inclusion of whom 5394 (43%) were deemed to be ineligible. Of the remaining patients 4617/7018 (66%) were inaccessible to the research team. The most common reasons being precipitous death, gatekeeping by clinical staff or rapid discharge. Of the 2410 patients who were visited by the research team and asked to participate in the study 1378 (57%) declined. Overall 8.2% (1018/12?412) of patients screened participated in the study. There were significant differences in recruitment patterns between hospice inpatient units, hospital support and community palliative care teams. Conclusions Systematic monitoring and analysis of patient flows through the clinical trial accrual process provided valuable insights about the reasons for failure to recruit patients to a clinical trial and may help to improve recruitment in future studies. PMID:24644750

  18. 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.

  19. 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).

  20. A novel method for correcting scanline-observational bias of discontinuity orientation

    PubMed Central

    Huang, Lei; Tang, Huiming; Tan, Qinwen; Wang, Dingjian; Wang, Liangqing; Ez Eldin, Mutasim A. M.; Li, Changdong; Wu, Qiong

    2016-01-01

    Scanline observation is known to introduce an angular bias into the probability distribution of orientation in three-dimensional space. In this paper, numerical solutions expressing the functional relationship between the scanline-observational distribution (in one-dimensional space) and the inherent distribution (in three-dimensional space) are derived using probability theory and calculus under the independence hypothesis of dip direction and dip angle. Based on these solutions, a novel method for obtaining the inherent distribution (also for correcting the bias) is proposed, an approach which includes two procedures: 1) Correcting the cumulative probabilities of orientation according to the solutions, and 2) Determining the distribution of the corrected orientations using approximation methods such as the one-sample Kolmogorov-Smirnov test. The inherent distribution corrected by the proposed method can be used for discrete fracture network (DFN) modelling, which is applied to such areas as rockmass stability evaluation, rockmass permeability analysis, rockmass quality calculation and other related fields. To maximize the correction capacity of the proposed method, the observed sample size is suggested through effectiveness tests for different distribution types, dispersions and sample sizes. The performance of the proposed method and the comparison of its correction capacity with existing methods are illustrated with two case studies. PMID:26961249

  1. A novel method for correcting scanline-observational bias of discontinuity orientation.

    PubMed

    Huang, Lei; Tang, Huiming; Tan, Qinwen; Wang, Dingjian; Wang, Liangqing; Ez Eldin, Mutasim A M; Li, Changdong; Wu, Qiong

    2016-01-01

    Scanline observation is known to introduce an angular bias into the probability distribution of orientation in three-dimensional space. In this paper, numerical solutions expressing the functional relationship between the scanline-observational distribution (in one-dimensional space) and the inherent distribution (in three-dimensional space) are derived using probability theory and calculus under the independence hypothesis of dip direction and dip angle. Based on these solutions, a novel method for obtaining the inherent distribution (also for correcting the bias) is proposed, an approach which includes two procedures: 1) Correcting the cumulative probabilities of orientation according to the solutions, and 2) Determining the distribution of the corrected orientations using approximation methods such as the one-sample Kolmogorov-Smirnov test. The inherent distribution corrected by the proposed method can be used for discrete fracture network (DFN) modelling, which is applied to such areas as rockmass stability evaluation, rockmass permeability analysis, rockmass quality calculation and other related fields. To maximize the correction capacity of the proposed method, the observed sample size is suggested through effectiveness tests for different distribution types, dispersions and sample sizes. The performance of the proposed method and the comparison of its correction capacity with existing methods are illustrated with two case studies. PMID:26961249

  2. Maximum entropy method helps study multifractal processes

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2011-11-01

    Many natural phenomena exhibit scaling behavior, in which parts of the system resemble the whole. Topography is one examplein some landscapes, shapes seen on a small scale look similar to shapes seen at larger scales. Some processes with scaling behavior are multifractal processes, in which the scaling parameters are described by probability distributions. Nieves et al. show that a method known as the maximum entropy method, which has been applied in information theory and statistical mechanics, can be applied generally to study the statistics of multifractal processes. The authors note that the method, which could be applied to a wide variety of geophysical systems, makes it possible to infer information on multifractal processes even beyond scales where observations are available. (Geophysical Research Letters, doi:10.1029/2011GL048716, 2011)

  3. Guidelines to Evaluate Human Observational Studies for Quantitative Risk Assessment

    PubMed Central

    Vlaanderen, Jelle; Vermeulen, Roel; Heederik, Dick; Kromhout, Hans

    2008-01-01

    Background Careful evaluation of the quality of human observational studies (HOS) is required to assess the suitability of HOS for quantitative risk assessment (QRA). In particular, the quality of quantitative exposure assessment is a crucial aspect of HOS to be considered for QRA. Objective We aimed to develop guidelines for the evaluation of HOS for QRA and to apply these guidelines to casecontrol and cohort studies on the relation between exposure to benzene and acute myeloid leukemia (AML). Methods We developed a three-tiered framework specific for the evaluation of HOS for QRA and used it to evaluate HOS on the relation between exposure to benzene and AML. Results The developed framework consists of 20 evaluation criteria. A specific focus of the framework was on the quality of exposure assessment applied in HOS. Seven HOS on the relation of benzene and AML were eligible for evaluation. Of these studies, five were suitable for QRA and were ranked based on the quality of the study design, conduct, and reporting on the study. Conclusion The developed guidelines facilitate a structured evaluation that is transparent in its application and harmonizes the evaluation of HOS for QRA. With the application of the guidelines, it was possible to identify studies suitable for QRA of benzene and AML and rank these studies based on their quality. Application of the guidelines in QRA will be a valuable addition to the assessment of the weight of evidence of HOS for QRA. PMID:19079723

  4. 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 (1318) 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

  5. 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

  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. 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.

  8. Benchmarking Physical Therapy Clinic Performance: Statistical Methods to Enhance Internal Validity When Using Observational Data

    PubMed Central

    Resnik, Linda; Liu, Dawei; Hart, Dennis L; Mor, Vince

    2008-01-01

    Many clinics and payers are beginning programs to collect and interpret outcomes related to quality of care and provider performance (ie, benchmarking). Outcomes assessment is commonly done using observational research designs, which makes it important for those involved in these endeavors to appreciate the underlying challenges and limitations of these designs. This perspective article discusses the advantages and limitations of using observational research to evaluate quality of care and provider performance in order to inform clinicians, researchers, administrators, and policy makers who want to use data to guide practice and policy or critically appraise observational studies and benchmarking efforts. Threats to internal validity, including potential confounding, patient selection bias, and missing data, are discussed along with statistical methods commonly used to address these limitations. An example is given from a recent study comparing physical therapy clinic performance in terms of patient outcomes and service utilization with and without the use of these methods. The authors demonstrate that crude differences in clinic outcomes and service utilization tend to be inflated compared with the differences that are statistically adjusted for selected threats to internal validity. The authors conclude that quality of care measurement and ranking procedures that do not use similar methods may produce findings that may be misleading. PMID:18689608

  9. 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...

  10. Comparison of methods for measurement of smoking behavior: Mouthpiece-based computerized devices versus direct observation

    PubMed Central

    Blank, Melissa D.; Disharoon, Steven

    2009-01-01

    Introduction: Understanding factors that influence tobacco use often involves detailed assessment of smoking behavior (i.e., puff topography) via mouthpiece-based, computerized devices. Research suggests that the use of a mouthpiece to evaluate topography may alter natural smoking behavior. This study was designed to compare topography measurement using mouthpiece-based methods (i.e., desktop and portable computerized devices) to methods that do not use a mouthpiece (i.e., direct observation). Methods: A total of 30 smokers (?15 full-flavor or light cigarettes/day) participated in six Latin squareordered, 2.5-hr experimental sessions that were preceded by at least 8 hr of objectively verified tobacco abstinence (carbon monoxide level ? 10 ppm). Each session consisted of participants smoking four cigarettes (own brand or Merit ultra-light) ad libitum, conventionally or using a desktop or portable device. Sessions were videotaped using a digital camcorder. Results: All three measurement methods were sensitive to oft-reported brand- and bout-induced changes. Topography measurement differed little between methods (across methods, all r values > .68), and each method was reliable (across bouts within each condition, most r values > .78). In contrast, participants perceived the use of either mouthpiece-based device to alter aspects of their smoking behavior (e.g., increased smoking difficulty, reduced enjoyment, altered cigarette taste; p < .05), relative to video recording only. Discussion: Although direct observational methods may be optimal for measuring certain smoking characteristics, logistical challenges posed by this method likely limit its usefulness. Together, these results suggest that mouthpiece-based devices offer a convenient and useful tool for researchers examining smoking topography. PMID:19525207

  11. A comparison of two direct-observation methods for measuring daytime safety belt use.

    PubMed

    Eby, D W; Streff, F M; Christoff, C

    1996-05-01

    This study compared two methods for measuring front-outboard shoulder-belt use: looking into vehicles when they stopped at a traffic control device (SVDO) and looking into vehicles as they traveled along a traffic corridor (MVDO). The reliability of the latter method has been questioned and certain surveys, such as the National Occupant Protection Use Survey (NOPUS), use both methods to estimate safety belt use. In one experiment, the methods were compared on overall belt use rates and reliability. A second experiment investigated the effect that vehicle speed had on an observer's ability to measure accurately belt use using the MVDO method. The results showed that daytime belt use rates between methods were nearly identical and inter-method reliability was quite high, indicating that front-outboard shoulder-belt use can be measured identically with either method. The second experiment showed that measurement accuracy was not affected by vehicle speeds of up to 60 mph and that overall accuracy was above 95%. PMID:8799445

  12. Evaluation of methods to derive green-up dates based on daily NDVI satellite observations

    NASA Astrophysics Data System (ADS)

    Doktor, Daniel

    2010-05-01

    Bridging the gap between satellite derived green-up dates and in situ phenological observations has been the purpose of many studies over the last decades. Despite substantial advancements in satellite technology and data quality checks there is as yet no universally accepted method for extracting phenological metrics based on satellite derived vegetation indices. Dependent on the respective method derived green-up dates can vary up to serveral weeks using identical data sets. Consequently, it is difficult to compare various studies and to accurately determine an increased vegetation length due to changing temperature patterns as observed by ground phenological networks. Here, I compared how the characteristic NDVI increase over temperate deciduous forests in Germany in spring relates to respective budburst events observed on the ground. MODIS Terra daily surface reflectances with a 250 m resolution (2000-2008) were gathered to compute daily NDVI values. As ground truth, observations of the extensive phenological network of the German Weather Service were used. About 1500 observations per year and species (Beech, Oak and Birch) were available evenly distributed all over Germany. Two filtering methods were tested to reduce the noisy raw data. The first method only keeps NDVI values which are classified as ‚ideal global quality' and applies on those a temporal moving window where values are removed which differ more than 20% of the mean. The second method uses an adaptation of the BISE (Best Index Slope Extraction) algorithm. Subsequently, three functions were fitted to the selected observations: a simple linear interpolation, a sigmoidal function and a double logistic sigmoidal function allowing to approximate two temporally separated green-up signals. The green-up date was then determined at halfway between minimum and maximum (linear interpolation) or at the inflexion point of the sigmoidal curve. A number of global threshold values (NDVI 0.4,0.5,0.6) and varying definitions of the NDVI baseline during dormancy were also tested. In contrast to most past studies, I did not attempt to identify matched pairs of geographically coincident ground and satellite observations. Rather than comparing on an individual grid-cell basis I analysed and compared the statistical properties of distributions generated from ground and satellite observations. It has been noticed that remote sensing provides a statistical distribution of a random variable, not an exact representation of the state of the land surface or atmosphere at a particular pixel. The same holds true for ground observations as they sample from biological variability and landscapes with heterogeneous microclimates. First results reveal substantial differences between the applied methods. Based on the assumption that the satellite captures predominantly the greening-up of the canopy - which occurs about 2 weeks later than observed budburst dates - the double sigmoidal function combined with the BISE filtering procedure performed best.

  13. 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.

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

    PubMed

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

    2005-08-01

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

  15. 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%

  16. 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

  17. Observational study of sites of triggered star formation. CO and mid-infrared observations

    NASA Astrophysics Data System (ADS)

    Urquhart, J. S.; Morgan, L. K.; Thompson, M. A.

    2009-04-01

    Context: Bright-rimmed clouds (BRCs) are isolated molecular clouds located on the edges of evolved HII regions. Star formation within these clouds may have been triggered through the propagation of photoionisation-induced shocks driven by the expansion of the HII region. Aims: The main focus of this paper is to investigate the current level of star formation within a sample of southern hemisphere BRCs and evaluate to what extent, if any, star formation may have been triggered. Methods: In this paper we present the results of a programme of position-switched CO observations towards 45 southern BRCs. The 12CO, 13CO and C18O J = 1-0 rotational transitions were simultaneously observed using the 22-m Mopra telescope. We complement these observations with archival mid-infrared data obtained from the MSX and Spitzer, as well as submillimetre and radio data previously reported in the literature. Combining all of the available data with the observations presented here allows us to build up a comprehensive picture of the current level of star formation activity within a significant number of BRCs. Results: Analysis of the CO, mid-infrared and radio data result in the clouds being divided into three distinct groups: a) clouds that appear to be relatively unaffected by the photoionisation from the nearby OB star(s); b) clouds that show evidence of significant interaction between the molecular material and the HII regions; c) clouds towards which no CO emission is detected, but are associated with strong ionisation fronts; these are thought to be examples of clouds undergoing an ionisation flash. We refer to these groups as spontaneous, triggered, and zapped clouds, respectively. Comparing the physical parameters of spontaneous and triggered samples we find striking differences in luminosity, surface temperature and column density with all three quantities significantly enhanced for the clouds considered to have been triggered. Furthermore, we find strong evidence for star formation within the triggered sample by way of methanol and H2O masers, embedded mid-infrared point sources and CO wings, however, we find evidence of ongoing star formation within only two of the spontaneous sample. Conclusions: We have used CO, mid-infrared and radio data to identify 24 of the 45 southern BRCs that are undergoing a strong interaction with their HII region. We can therefore exclude the other 21 sources (~50%) from future studies of triggered star formation. Fourteen of the 24 interacting BRCs are found to be associated with embedded mid-infrared point sources and we find strong evidence that these clouds are forming stars. The absence of mid-infrared sources towards the remaining ten clouds and the lack of any other evidence of star formation within these clouds leads us to conclude that these represent an earlier evolutionary stage of star formation. Figure 9 is only available in electronic form at http://www.aanda.org

  18. 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.

  19. Direct Insights Into Observational Absorption Line Analysis Methods of the Circumgalactic Medium Using Cosmological Simulations

    NASA Astrophysics Data System (ADS)

    Churchill, Christopher W.; Vander Vliet, Jacob R.; Trujillo-Gomez, Sebastian; Kacprzak, Glenn G.; Klypin, Anatoly

    2015-03-01

    We study the circumgalactic medium (CGM) of a z = 0.54 simulated dwarf galaxy using hydroART simulations. We present our analysis methods, which emulate observations, including objective absorption line detection, apparent optical depth (AOD) measurements, Voigt profile (VP) decomposition, and ionization modeling. By comparing the inferred CGM gas properties from the absorption lines directly to the gas selected by low ionization H i and Mg ii, and by higher ionization C iv and O vi absorption, we examine how well observational analysis methods recover the true properties of CGM gas. In this dwarf galaxy, low ionization gas arises in sub-kiloparsec cloud structures, but high ionization gas arises in multiple extended structures spread over 100 kpc; due to complex velocity fields, highly separated structures give rise to absorption at similar velocities. We show that AOD and VP analysis fails to accurately characterize the spatial, kinematic, and thermal conditions of high ionization gas. We find that H i absorption selected gas and O vi absorption gas arise in totally distinct physical gas structures, calling into question current observational techniques employed to infer metallicities and the total mass of warm-hot CGM gas. We present a method to determine whether C iv and O vi absorbing gas is photo or collisionally ionized and whether the assumption of ionization equilibrium is sound. As we discuss, these and additional findings have strong implications for how accurately currently employed observational absorption line methods recover the true gas properties, and ultimately, our ability to understand the CGM and its role in galaxy evolution.

  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 andfor both neonate and motherinfections, 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. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 29, METHOD 624--PURGEABLES

    EPA Science Inventory

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

  2. 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...

  3. NMR Methods to Study Dynamic Allostery

    PubMed Central

    Grutsch, Sarina; Brüschweiler, Sven; Tollinger, Martin

    2016-01-01

    Nuclear magnetic resonance (NMR) spectroscopy provides a unique toolbox of experimental probes for studying dynamic processes on a wide range of timescales, ranging from picoseconds to milliseconds and beyond. Along with NMR hardware developments, recent methodological advancements have enabled the characterization of allosteric proteins at unprecedented detail, revealing intriguing aspects of allosteric mechanisms and increasing the proportion of the conformational ensemble that can be observed by experiment. Here, we present an overview of NMR spectroscopic methods for characterizing equilibrium fluctuations in free and bound states of allosteric proteins that have been most influential in the field. By combining NMR experimental approaches with molecular simulations, atomistic-level descriptions of the mechanisms by which allosteric phenomena take place are now within reach. PMID:26964042

  4. Conceptual study of debris observation and arresting experiment satellite

    NASA Astrophysics Data System (ADS)

    Kimoto, Kenichi; Mori, Hatsuo; Satou, Keiichi; Kitazawa, Yukihito; Miyoshi, Kouichi

    1992-07-01

    Present status of debris environment and predictable damage caused by them, such as effects to manned space activities, damage of satellite or other spacecraft caused by their collision, dropping of substances to the ground, radioactive contamination, effects to astronomical observation, and interference with space experiments are outlined. An overview of present status and problems of debris observation and tracking system and an ideal debris observation system is presented. The objectives of a debris observation and arresting system and definition of their subjects are introduced. The results of studies of observation equipment (sensors), including contacting and non-contacting sensors, and their selection is introduced. Orbits, mission duration, operational condition, and overall satellite systems are outlined.

  5. The role of local observations as evidence to inform effective mitigation methods for flood risk management

    NASA Astrophysics Data System (ADS)

    Quinn, Paul; ODonnell, Greg; Owen, Gareth

    2014-05-01

    This poster presents a case study that highlights two crucial aspects of a catchment-based flood management project that were used to encourage uptake of an effective flood management strategy. Specifically, (1) the role of detailed local scale observations and (2) a modelling method informed by these observations. Within a 6km2 study catchment, Belford UK, a number of Runoff Attenuation Features (RAFs) have been constructed (including ponds, wetlands and woody debris structures) to address flooding issues in the downstream village. The storage capacity of the RAFs is typically small (200 to 500m3), hence there was skepticism as to whether they would work during large flood events. Monitoring was performed using a dense network of water level recorders installed both within the RAFs and within the stream network. Using adjacent upstream and downstream water levels in the stream network and observations within the actual ponds, a detailed understanding of the local performance of the RAFs was gained. However, despite understanding the local impacts of the features, the impact on the downstream hydrograph at the catchment scale could still not be ascertained with any certainty. The local observations revealed that the RAFs typically filled on the rising limb of the hydrograph; hence there was no available storage at the time of arrival of a large flow peak. However, it was also clear that an impact on the rising limb of the hydrograph was being observed. This knowledge of the functioning of individual features was used to create a catchment model, in which a network of RAFs could then be configured to examine the aggregated impacts. This Pond Network Model (PNM) was based on the observed local physical relationships and allowed a user specified sequence of ponds to be configured into a cascade structure. It was found that there was a minimum number of RAFs needed before an impact on peak flow was achieved for a large flood event. The number of RAFs required in the network was also found to differ between events, due to the timing and shape of the hydrograph. However, once a threshold was crossed, for each additional RAF added, a clear impact on the peak flow was observed. Using a selection of observed flood events and design storms; a typical range of 15 to 35 percent reduction in flow peak was achieved with 35 RAFs. Now that 40 RAFs have been constructed in Belford, the local Environment Agency is confident that the scheme is working satisfactory. Crucially, it was the detailed local observations that informed the design of the PNM and it demonstrated to end users why the approach was working. The RAF network approach is being taken up elsewhere.

  6. 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.

  7. Using the Nordic Geodetic Observing System for land uplift studies

    NASA Astrophysics Data System (ADS)

    Nordman, M.; Poutanen, M.; Kairus, A.; Virtanen, J.

    2014-07-01

    Geodetic observing systems have been planned and developed during the last decade. An ideal observing system consists of a network of geodetic observing stations with several techniques at the same site, publicly accessible databases, and as a product delivers data time series, combination of techniques or some other results obtained from the data sets. Globally, there is the International Association of Geodesy (IAG) Global Geodetic Observing System (GGOS), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, the Nordic Geodetic Observing System (NGOS) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss in general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such a database, we apply it for postglacial rebound studies in the Fennoscandian area. We compare land uplift values from three techniques, GNSS, tide gauges and absolute gravity, with the Nordic Geodetic Commission NKG2005LU land uplift model for Fennoscandia. The purpose is to evaluate the data obtained from different techniques and different sources and get the most reliable values for the uplift using publicly available data. The primary aim of observing systems will be to produce data and other products needed by multidisciplinary projects, such as Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas (DynaQlim) or the European Plate Observing System (EPOS), but their needs may currently exceed the scope of an existing observing system. We discuss what requirements the projects pose to observing systems and their development. To make comparisons between different studies possible and reliable, the researcher should document what they have in detail, either in appendixes, supplementary material or some other available format.

  8. Home Videophones Improve Direct Observation in Tuberculosis Treatment: A Mixed Methods Evaluation

    PubMed Central

    Wade, Victoria A.; Karnon, Jonathan; Eliott, Jaklin A.; Hiller, Janet E.

    2012-01-01

    Background The use of direct observation to monitor tuberculosis treatment is controversial: cost, practical difficulties, and lack of patient acceptability limit effectiveness. Telehealth is a promising alternative delivery method for improving implementation. This study aimed to evaluate the clinical and cost-effectiveness of a telehealth service delivering direct observation, compared to an in-person drive-around service. Methodology/Principal Findings The study was conducted within a community nursing service in South Australia. Telehealth patients received daily video calls at home on a desktop videophone provided by the nursing call center. A retrospective cohort study assessed the effectiveness of the telehealth and traditional forms of observation, defined by the proportion of missed observations recorded in case notes. This data was inputted to a model, estimating the incremental cost-effectiveness ratio (ICER) of telehealth. Semi-structured interviews were conducted with current patients, community nursing and Chest Clinic staff, concerning service acceptability, usability and sustainability. The percentage of missed observations for the telehealth service was 12.1 (n = 58), compared to 31.1 for the in-person service (n = 70). Most of the difference of 18.9% (95% CI: 12.2 – 25.4) was due to fewer pre-arranged absences. The economic analysis calculated the ICER to be AUD$1.32 (95% CI: $0.51 – $2.26) per extra day of successful observation. The video service used less staff time, and became dominant if implemented on a larger scale and/or with decreased technology costs. Qualitative analysis found enabling factors of flexible timing, high patient acceptance, staff efficiency, and Chest Clinic support. Substantial technical problems were manageable, and improved liaison between the nursing service and Chest Clinic was an unexpected side-benefit. Conclusions/Significance Home video observation is a patient-centered, resource efficient way of delivering direct observation for TB, and is cost-effective when compared with a drive-around service. Future research is recommended to determine applicability and effectiveness in other settings. PMID:23226243

  9. Radiation energy budget studies using collocated AVHRR and ERBE observations

    SciTech Connect

    Ackerman, S.A.; Inoue, Toshiro

    1994-03-01

    Changes in the energy balance at the top of the atmosphere are specified as a function of atmospheric and surface properties using observations from the Advanced Very High Resolution Radiometer (AVHRR) and the Earth Radiation Budget Experiment (ERBE) scanner. By collocating the observations from the two instruments, flown on NOAA-9, the authors take advantage of the remote-sensing capabilities of each instrument. The AVHRR spectral channels were selected based on regions that are strongly transparent to clear sky conditions and are therefore useful for characterizing both surface and cloud-top conditions. The ERBE instruments make broadband observations that are important for climate studies. The approach of collocating these observations in time and space is used to study the radiative energy budget of three geographic regions: oceanic, savanna, and desert. 25 refs., 8 figs.

  10. Radiation energy budget studies using collocated AVHRR and ERBE observations

    NASA Technical Reports Server (NTRS)

    Ackerman, Steven A.; Inoue, Toshiro

    1994-01-01

    Changes in the energy balance at the top of the atmosphere are specified as a function of atmospheric and surface properties using observations from the Advanced Very High Resolution Radiometer (AVHRR) and the Earth Radiation Budget Experiment (ERBE) scanner. By collocating the observations from the two instruments, flown on NOAA-9, the authors take advantage of the remote-sensing capabilities of each instrument. The AVHRR spectral channels were selected based on regions that are strongly transparent to clear sky conditions and are therefore useful for characterizing both surface and cloud-top conditions. The ERBE instruments make broadband observations that are important for climate studies. The approach of collocating these observations in time and space is used to study the radiative energy budget of three geographic regions: oceanic, savanna, and desert.

  11. Geospatial web services for limnological data: a case study of sensor observation service for ecological observations

    NASA Astrophysics Data System (ADS)

    Arias Muoz, C.; Oggioni, A.; Brovelli, M. A.

    2014-04-01

    The present work aims at designing and implementing a spatial data infrastructure for storing and sharing ecological data through geospatial web services. As case study, we concentrated on limnological data coming from the drainage basin of Lake Maggiore in the Northern of Italy. In order to establish the infrastructure, we started with two basic questions: (1) What type of data is the ecological dataset? (2) Which are the geospatial web services standards most suitable to store and share ecological data? In this paper we describe the possibilities for sharing ecological data using geospatial web services and the difficulties that can be encountered in this task. In order to test actual technological solutions, we use real data of a limnological published study.We concluded that limnological data can be considered observational data, composed by biological (species) data and environmental data, and it can be modeled using Observation and Measurement (O&M) specification. With the actual web service implementation the geospatial web services that could potentially be used to publish limnological data are Sensor Observation Services (SOS) and Web Feature Services (WFS). SOS holds the essential components to represent time series observations, while WFS is a simple model that requires profiling. Both, SOS and WFS are not perfectly suitable to publish biological data, so other alternatives must be considered, as linked data.

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

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

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

  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. 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 ρ, whereas the right ascension α and the declination δ are much more inaccurate due to observational errors. This method can correct α, δ, assuming the exact knowledge of the range ρ. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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...

  1. 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…

  2. Space observations for global and regional studies of the biosphere

    NASA Technical Reports Server (NTRS)

    Cihlar, J.; Li, Z.; Chen, J.; Sellers, P.; Hall, F.

    1994-01-01

    The capability to make space-based measurements of Earth at high spatial and temporal resolutions, which would not otherwise be economically or practically feasible, became available just in time to contribute to scientific understanding of the interactive processes governing the total Earth system. Such understanding has now become essential in order to take practical steps which would counteract or mitigate the pervasive impact of the growing human population on the future habitability of the Earth. The paper reviews the rationale for using space observations for studies of climate and terrestrial ecosystems at global and regional scales, as well as the requirements for such observations for studies of climate and ecosystem dynamics. The present status of these developments is reported along with initiatives under way to advance the use of satellite observations for Earth system studies. The most important contribution of space observations is the provision of physical or biophysical parameters for models representing various components of the Earth system. Examples of such parameters are given for climatic and ecosystem studies.

  3. 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.

  4. COMPARISON OF METHODS FOR THE ANALYSIS OF PANEL STUDIES

    EPA Science Inventory

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

  5. 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;

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  8. 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

  9. Methods for estimating subgroup effects in cost-effectiveness analyses that use observational data.

    PubMed

    Kreif, Noemi; Grieve, Richard; Radice, Rosalba; Sadique, Zia; Ramsahai, Roland; Sekhon, Jasjeet S

    2012-01-01

    Decision makers require cost-effectiveness estimates for patient subgroups. In nonrandomized studies, propensity score (PS) matching and inverse probability of treatment weighting (IPTW) can address overt selection bias, but only if they balance observed covariates between treatment groups. Genetic matching (GM) matches on the PS and individual covariates using an automated search algorithm to directly balance baseline covariates. This article compares these methods for estimating subgroup effects in cost-effectiveness analyses (CEA). The motivating case study is a CEA of a pharmaceutical intervention, drotrecogin alfa (DrotAA), for patient subgroups with severe sepsis (n = 2726). Here, GM reported better covariate balance than PS matching and IPTW. For the subgroup at a high level of baseline risk, the probability that DrotAA was cost-effective ranged from 30% (IPTW) to 90% (PS matching and GM), at a threshold of £20 000 per quality-adjusted life-year. We then compared the methods in a simulation study, in which initially the PS was correctly specified and then misspecified, for example, by ignoring the subgroup-specific treatment assignment. Relative performance was assessed as bias and root mean squared error (RMSE) in the estimated incremental net benefits. When the PS was correctly specified and inverse probability weights were stable, each method performed well; IPTW reported the lowest RMSE. When the subgroup-specific treatment assignment was ignored, PS matching and IPTW reported covariate imbalance and bias; GM reported better balance, less bias, and more precise estimates. We conclude that if the PS is correctly specified and the weights for IPTW are stable, each method can provide unbiased cost-effectiveness estimates. However, unlike IPTW and PS matching, GM is relatively robust to PS misspecification. PMID:22691446

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

    EPA Science Inventory

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

  11. 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)

  12. A Focus on Mixed-Phase Clouds: The Status of Ground-Based Observational Methods

    SciTech Connect

    Shupe, Matthew D.; Daniel, J. S.; DeBoer, GIJS; Eloranta, E. W.; Kollias, Pavlos; Long, Charles N.; Luke, Edward; Turner, David D.; Verlinde, J.

    2008-10-28

    The phase composition and microphysical structure of clouds define the manner in which they modulate atmospheric radiation and contribute to the hydrologic cycle. Issues regarding cloud phase balance and transformation come to bear directly in mixed-phase clouds, and have been difficult to address within current modeling frameworks. Groundbased, remote-sensing observations of mixed-phase clouds can contribute a significant body of knowledge with which to better understand, and thereby more accurately model, clouds and their phase-defining processes. Utilizing observational case studies from the Mixed-Phase Arctic Cloud Experiment (M-PACE), which occurred at the D.O.E. Atmospheric Radiation Measurement (ARM) Programs atmospheric observatory in Barrow, Alaska during autumn 2004, we review the current status of ground-based observation and retrieval methods towards characterizing the macrophysical, microphysical, radiative, and dynamical properties of mixed-phase clouds. In general, cloud phase, boundaries, ice properties, liquid water path, optical depth, and vertical velocity are available from a combination of active and passive sensors. Significant deficiencies exist in our abilities to vertically characterize the liquid phase, to distinguish the ice crystal habits, and to understand the aerosol-cloud interaction in mixed-phase clouds.

  13. A Method to Determine Station Density Requirements for Climate Observing Networks.

    NASA Astrophysics Data System (ADS)

    Vose, Russell S.; Menne, Matthew J.

    2004-08-01

    A procedure is described that provides guidance in determining the number of stations required in a climate observing system deployed to capture temporal variability in the spatial mean of a climate parameter. The method entails reducing the density of an existing station network in a step-by-step fashion and quantifying subnetwork performance at each iteration. Under the assumption that the full network for the study area provides a reasonable estimate of the true spatial mean, this degradation process can be used to quantify the relationship between station density and network performance. The result is a systematic cost benefit relationship that can be used in conjunction with practical constraints to determine the number of stations to deploy.The approach is demonstrated using temperature and precipitation anomaly data from 4012 stations in the conterminous United States over the period 1971 2000. Results indicate that a U.S. climate observing system should consist of at least 25 quasi-uniformly distributed stations in order to reproduce interannual variability in temperature and precipitation because gains in the calculated performance measures begin to level off with higher station numbers. If trend detection is a high priority, then a higher density network of 135 evenly spaced stations is recommended. Through an analysis of long-term observations from the U.S. Historical Climatology Network, the 135-station solution is shown to exceed the climate monitoring goals of the U.S. Climate Reference Network.


  14. A Study of the Extratropical Tropopause from Observations and Models

    NASA Astrophysics Data System (ADS)

    Wang, Shu Meir

    The extratropical tropopause is a familiar feature in meteorology; however, the understanding of the mechanisms for its existence, formation, maintenance and sharpness is still an active area of research. Son and Povalni (2007) used a simple general circulation model to produce the TIL (Tropopause Inversion Layer), and they found that the extratropical tropopause is more sensitive to the change of the horizontal resolution than to the change of the vertical resolution. The extratropical tropopause is sharper and lower in higher horizontal resolution. They also successfully mimicked the seasonal variation of the extratropical tropopause by changing the Equator-to-Pole temperature difference. They found these features of the extratropical tropopause, but they did not explain why these features were seen in their simplified model. In this research, we try to explain why these features of the extratropical tropopause are seen from both observations and the models. I have shown in my MS thesis that the distance from the jet is more associated with the extratropical tropopause than is the upper tropospheric relative vorticity (Wirth, 2001) from observations. In this research, the reproduction of the work is done from both the idealized and the full model run, and the results are similar to those from the observations, which show that even on synoptic time scales, the distance from the jet is more important in determining the extratropical tropopause height than is the upper tropospheric relative vorticity. It also explains the seasonal variations of the extratropical tropopause since the jet is more poleward in summer than in winter (the Equator-to-Pole temperature difference is smaller in summer than in winter), thus there is larger area at south of the jet which means the extratropical tropopause is sharper and higher at midlatitudes in summer than in winter. We believe that baroclinic mixing of PV is the key factor that sharpens the extratropical tropopause, and adequate horizontal resolution is needed to resolve the baroclinic mixing and the small-scale filamentary structures. We used many methods in this study to show that there is more baroclinic activity seen in higher horizontal resolution. We also compared the correlations of the tropopause height with three variations in different quantities (PV fluxes, the upper tropospheric vorticity, and heat fluxes), and found that the correlations of the tropopause height and PV fluxes are the highest among the three. Thus, we conclude that baroclinic mixing is the most important factor that controls the extratropical tropopause sharpness. This also explains why the extratropical tropopause is sharper at midlatitudes when higher horizontal resolution is used (see figure 2.4 in the thesis and figure 2 in Son and Polvani's (2007)) since there is more baroclinic activity in the higher horizontal resolution models. Since there is more baroclinic activity seen in higher horizontal resolution, the baroclinic eddy drag is larger, which intensifies the thermally direct cell. The stronger thermally direct cell with higher horizontal resolution has greater downward motion in higher latitudes, and thus lowers the extratropical tropopause more in higher horizontal resolution models, which explains why the extratropical tropopause is lower in higher horizontal than in lower horizontal resolution models, as in Son and Polvani's (2007) paper.

  15. Impulse strobing method in superlong baseline radiointerferometry for observing geostationary artificial Earth satellites.

    NASA Astrophysics Data System (ADS)

    Gorodetskij, V. M.

    The new possibility of synthesizing the wide frequency band for the VLBI observation of slowly moving objects with the standard MARK-1 processing system using the impulse strobing method is described. It is shown that the signal-to-noise ratio may be improved due to specific type of the impulse function. An original system of realization of these methods in the satellite VLBI observation is suggested.

  16. An Observational Method in the Foreign Language Classroom: A Closer Look at Interaction Analysis

    ERIC Educational Resources Information Center

    Bailey, Leona G.

    1975-01-01

    This paper analyzes both Flanders' and the Foreign Language Interaction (FLint) methods of classroom observation and concludes that both systems are deficient in accuracy, reliability and practicality. Observing, recording and decision-making difficulties are inherent, and system complexities and teacher biases add to the problems. (CHK)

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

    NASA Astrophysics Data System (ADS)

    Han, J.; Salomonson, V. V.

    2007-12-01

    The MODIS instruments on the Terra and Aqua spacecraft provide snow cover observations on a daily basis when cloud cover permits over the globe as well as regional and local areas. This study reports some ongoing work using Terra MODIS snow cover observations centered on the Weber River Basin. The basin covers 2500 square miles/6400 square kilometers within the Great Salt Lake Basin in Utah. This report is focused on comparing various snow mapping methods in observing snow cover in this basin during the first six months (January to June) of 2001. The methods compared are the standard 8-day SNOWMAP results provided operationally by MODIS (designated MOD10A2 on lists of MODIS products), the fractional snow cover product (MOD10L2) for specific days, and the spectral end-member approach using three end-members:snow, soil and rock, and vegetation. The results show the expected variation of snow cover with time over the Weber Basin, but with distinct differences in the extent of the snow cover ranging from the SNOWMAP typically showing the largest snow cover due to the 8-day product giving maximum snow cover and the spectral end-member approach showing the least. Comparisons with more detailed imagery tends to indicate that, as expected, the spectral end-member approach appears to be the most accurate. In non-snow covered regions of the Weber River Basin there are anomalies (e.g. snow appearing where there is obviously no snow) and these anomalies are under investigation.

  18. Determining Best Method for Estimating Observed Level of Maximum Convective Detrainment based on Radar Reflectivity

    NASA Astrophysics Data System (ADS)

    Carletta, N.; Mullendore, G. L.; Xi, B.; Feng, Z.; Dong, X.

    2013-12-01

    Convective mass transport is the transport of mass from near the surface up to the upper troposphere and lower stratosphere (UTLS) by a deep convective updraft. This transport can alter the chemical makeup and water vapor balance of the UTLS, which can affect cloud formation and the radiative properties of the atmosphere. It is therefore important to understand the exact altitudes at which mass is detrained from convection. The purpose of this study is to improve upon previously published methodologies for estimating the level of maximum detrainment (LMD) within convection using data from individual radars. Three methods were used to identify the LMD and validated against dual-Doppler derived vertical mass divergence fields. The best method for locating the LMD was determined to be the method that uses a horizontal reflectivity texture-based technique to determine convective cores and a multi-layer echo identification to determine anvil locations. The methodology was found to work in many but not all cases. The methodology works best when applied to convective systems with mature updrafts, and is most accurate with convective lines and single cells. A time lag is present in the reflectivity based LMD compared to the vertical mass divergence based LMD because the reflectivity method is dependent on anvil growth. This methodology was then applied to archived NEXRAD 3D mosaic radar data. The regions of analysis were chosen to coincide with the observation regions for the Deep Convective Clouds and Chemistry Experiment (DC3): the Colorado Foothills, Southern Plains (OK/TX), and Southeast US (AL). These three regions provide a wide variety of convection. The dates analyzed were from May and June of 2012 so the results can be compared to future DC3 studies. The variability of detrainment heights for the early convective season for these different geographical regions will be presented.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  20. 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.

  1. Stereomorphologic observation of bone tissue response to hydroxyapatite using SEM with the EDTA-KOH method.

    PubMed

    Lin, T C; Su, C Y; Chang, C S

    1997-07-01

    To obtain further information on the interaction of hydroxyapatite (HA) and the bony implantation bed, 20- to 40- mesh dense HA particles were implanted into the tibiae of dogs. Following healing periods of 2 weeks, 1 month, and 3 months, the specimens were retrieved and prepared by either conventional preparatory procedures for scanning electron microscopy (SEM) of the EDTA-KOH method. Under SEM observation, the interparticular osteogenesis among HA particles progressed in a programmed sequence. Ample blood supply and osteoblasts initially presented in the interparticular space. The secretion of bone matrix resulted in the formation of immature bone. This scaffold was then transformed into mature lamellar bone during the following bone remodeling process. The serial changes closely resembled the pattern viewed in controls that did not implant HA. A spatial relationship between bone cells and HA was clearly demonstrated. In particular, the osteoblasts displayed an extremely flat appearance with many microappendages. The microappendages anchored cells to the HA surface and fused with granular material covering the HA crystals. The more characteristic cellular morphology was revealed by the EDTA-KOH method. Microscopic pictures clearly identified the three-dimensional images of ruffled borders of osteoclasts and the slender cytoplasmic processes of osteocytes. This study provided further evidence for the favorable biological response of HA to bone cells as well as the value of the EDTA-KOH method in examining the stereomorphology of bone cells. PMID:9212393

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

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

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

  3. [Method-performance studies of notified analytical method for clofentezine].

    PubMed

    Sasaki, K; Tatsuno, T; Nakamura, M; Imazawa, T; Utsunomiya, O; Kondo, Y; Osada, H; Takahata, K; Toyoda, M

    2001-08-01

    Method-performance studies were conducted for the notified revised analytical method of clofentezine. Clofentezine spiked in azuki beans, apple, orange, banana, grape, tea powder and tea extract at the level of 0.2 microgram/g (2 micrograms/g for tea) was analyzed in replicate in 6 laboratories. Mean values of recovery from 7 crops ranged from 78.4 to 85.2%. Repeatability relative standard deviation values ranged from 2.2 to 4.6% and reproducibility standard deviation values ranged from 4.8 to 10.3%. The detection limits were 0.005-0.01 microgram/g. These results show the notified analytical method has good performance. PMID:11817146

  4. 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

  5. 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.

  6. 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…

  7. 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

  8. 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.

  9. Studies of waves in sunspots using spectropolarimetric observations

    NASA Astrophysics Data System (ADS)

    MacDonald, Gordon A.; Rajaguru, S. P.

    2011-08-01

    We observe the acoustic velocity oscillations in and near active region NOAA 10960 on 8 June, 2007 using observations from the IBIS instrument at the Dunn Solar Telescope at NSO/Sacramento Peak and simultaneous Hinode BFI/SP data. Inversions were performed on the spectropolarimetric datasets in order to get magnetic field information for the AR. A time series of Doppler maps from line bisectors and Stokes V zero-crossing was constructed and allowed us to construct power maps for the AR. Past works by various authors have shown that acoustic power in the solar atmosphere is strongly influenced by magnetic field strength and inclination. Our study also explores this, but in addition, we also discuss the role of oscillations due to purely magnetized gas in the photosphere. Our preliminary results for this study are presented.

  10. Strategies GeoCape Intelligent Observation Studies @ GSFC

    NASA Technical Reports Server (NTRS)

    Cappelaere, Pat; Frye, Stu; Moe, Karen; Mandl, Dan; LeMoigne, Jacqueline; Flatley, Tom; Geist, Alessandro

    2015-01-01

    This presentation provides information a summary of the tradeoff studies conducted for GeoCape by the GSFC team in terms of how to optimize GeoCape observation efficiency. Tradeoffs include total ground scheduling with simple priorities, ground scheduling with cloud forecast, ground scheduling with sub-area forecast, onboard scheduling with onboard cloud detection and smart onboard scheduling and onboard image processing. The tradeoffs considered optimzing cost, downlink bandwidth and total number of images acquired.

  11. The New Worlds Observer: the astrophysics strategic mission concept study

    NASA Astrophysics Data System (ADS)

    Cash, Webster; Kendrick, Stephen; Noecker, Charley; Bally, John; Demarines, Julia; Green, James; Oakley, Phillip; Shipley, Ann; Benson, Scott; Oleson, Steve; Content, David; Folta, Dave; Garrison, Sharon; Gendreau, Keith; Hartman, Kate; Howard, Joseph; Hyde, Tupper; Lakins, Darryl; Leitner, Jesse; Leviton, Douglas; Luquette, Rich; Oegerley, Bill; Richon, Karen; Roberge, Aki; Tompkins, Steve; Tveekrem, June; Woodgate, Bruce; Turnbull, Margaret; Dailey, Dean; Decker, Kent; Dehmohseni, Reza; Gaugh, Brian; Glassman, Tiffany; Haney, Mickey; Hejal, Reem; Lillie, Charles; Lo, Amy; O'Conner, David; Oleas, Gina; Polidan, Ronald; Samuele, Rocco; Shields, Stephen; Shirvanian, James; Soohoo, David; Tinetti, Giovanna; Dorland, Bryan; Dudik, Rachel; Gaume, Ralph; Mason, Brian

    2009-08-01

    We present the results of the Astrophysics Strategic Mission Concept Study for the New Worlds Observer (NWO). We show that the use of starshades is the most effective and affordable path to mapping and understanding our neighboring planetary systems, to opening the search for life outside our solar system, while serving the needs of the greater astronomy community. A starshade-based mission can be implemented immediately with a near term program of technology demonstration.

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  13. 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.

  14. Some observations on a new numerical method for solving Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Kumar, A.

    1981-01-01

    An explicit-implicit technique for solving Navier-Stokes equations is described which, is much less complex than other implicit methods. It is used to solve a complex, two-dimensional, steady-state, supersonic-flow problem. The computational efficiency of the method and the quality of the solution obtained from it at high Courant-Friedrich-Lewy (CFL) numbers are discussed. Modifications are discussed and certain observations are made about the method which may be helpful in using it successfully.

  15. [General concepts and study methods in pharmacogenetics].

    PubMed

    Lubomirov, Rubin; Telenti, Amalio; Rotger, Margalida

    2008-05-01

    Pharmacogenetics, the study of how individual genetic profiles influence the response to drugs, is an important topic. Results from pharmacogenetics studies in various clinical settings may lead to personalized medicine. Herein, we present the most important concepts of this discipline, as well as currently-used study methods. PMID:18680690

  16. 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.

  17. Observational studies of reconnection in the solar corona

    SciTech Connect

    McKenzie, David E.

    2011-11-15

    In recent years, observational studies of the corona have shifted focus. Where they were once purely qualitative morphological explorations seeking to support the presence of reconnection, more investigations are providing empirical estimates of the physical conditions in the reconnecting corona. These studies are enabled and enhanced by orbiting telescopes with high angular and temporal resolution. In this article, some recent findings about the empirical quantities are reviewed, including recent estimates of the flux transferred in individual patchy reconnection episodes, the size distribution of post-reconnection flux tubes, and the energy released by the flux tubes as they shrink.

  18. Mathematical methods of studying physical phenomena

    NASA Astrophysics Data System (ADS)

    Man'ko, Margarita A.

    2013-03-01

    In recent decades, substantial theoretical and experimental progress was achieved in understanding the quantum nature of physical phenomena that serves as the foundation of present and future quantum technologies. Quantum correlations like the entanglement of the states of composite systems, the phenomenon of quantum discord, which captures other aspects of quantum correlations, quantum contextuality and, connected with these phenomena, uncertainty relations for conjugate variables and entropies, like Shannon and Rényi entropies, and the inequalities for spin states, like Bell inequalities, reflect the recently understood quantum properties of micro and macro systems. The mathematical methods needed to describe all quantum phenomena mentioned above were also the subject of intense studies in the end of the last, and beginning of the new, century. In this section of CAMOP 'Mathematical Methods of Studying Physical Phenomena' new results and new trends in the rapidly developing domain of quantum (and classical) physics are presented. Among the particular topics under discussion there are some reviews on the problems of dynamical invariants and their relations with symmetries of the physical systems. In fact, this is a very old problem of both classical and quantum systems, e.g. the systems of parametric oscillators with time-dependent parameters, like Ermakov systems, which have specific constants of motion depending linearly or quadratically on the oscillator positions and momenta. Such dynamical invariants play an important role in studying the dynamical Casimir effect, the essence of the effect being the creation of photons from the vacuum in a cavity with moving boundaries due to the presence of purely quantum fluctuations of the electromagnetic field in the vacuum. It is remarkable that this effect was recently observed experimentally. The other new direction in developing the mathematical approach in physics is quantum tomography that provides a new vision of quantum states. In the tomographic picture of quantum mechanics, the states are identified with fair conditional probability distributions, which contain the same information on the states as the wave function or the density matrix. The mathematical methods of the tomographic approach are based on studying the star-product (associative product) quantization scheme. The tomographic star-product technique provides an additional understanding of the associative product, which is connected with the existence of specific pairs of operators called quantizers and dequantizers. These operators code information on the kernels of all the star-product schemes, including the traditional phase-space Weyl-Wigner-Moyal picture describing the quantum-system evolution. The new equation to find quantizers, if the kernel of the star product of functions is given, is presented in this CAMOP section. For studying classical systems, the mathematical methods developed in quantum mechanics can also be used. The case of paraxial-radiation beams propagating in waveguides is a known example of describing a purely classical phenomenon by means of quantum-like equations. Thus, some quantum phenomenon like the entanglement can be mimicked by the properties of classical beams, for example, Gaussian modes. The mathematical structures and relations to the symplectic symmetry group are analogous for both classical and quantum phenomena. Such analogies of the mathematical classical and quantum methods used in research on quantum-like communication channels provide new tools for constructing a theoretical basis of the new information-transmission technologies. The conventional quantum mechanics and its relation to classical mechanics contain mathematical recipes of the correspondence principle and quantization rules. Attempts to find rules for deriving the quantum-mechanical formalism starting from the classical field theory, taking into account the influence of classical fluctuations of the field, is considered in these papers. The methods to solve quantum equations and formulate the boundary conditions in the problems with singular potentials are connected with the mathematical problems of self-adjointness of the Hamiltonians. The progress and some new results in this direction are reflected in this CAMOP section. The Gaussian states of the photons play an important role in quantum optics. The multimode electromagnetic field and quantum correlations in the Gaussian states are considered in this section. The new results in the statistical properties of the laser radiation discussed here are based on applications of mathematical methods in this traditional domain of physics. It is worth stressing that the universality of the mathematical procedures permitted to consider the physical phenomena in the ocean is on the same footing as the phenomena in the microworld. In this CAMOP section, there are also papers devoted to traditional problems of solving the Schrödinger equation for interesting quantum systems. Recently obtained results related to different domains of theoretical physics are united by applying mathematical methods and tools, that provide new possibilities to better understand the theoretical foundations needed to develop new quantum technologies like quantum computing and quantum communications. The papers are arranged alphabetically by the name of the first author. We are grateful to all authors who accepted our invitation to contribute to this CAMOP section.

  19. 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

  20. 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

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

    PubMed

    Granberg-Axll, 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

  2. Evaluating Processes, Parameters and Observations Using Cross Validation and Computationally Frugal Sensitivity Analysis Methods

    NASA Astrophysics Data System (ADS)

    Foglia, L.; Mehl, S.; Hill, M. C.

    2013-12-01

    Sensitivity analysis methods are used to identify measurements most likely to provide important information for model development and predictions and therefore identify critical processes. Methods range from computationally demanding Monte Carlo and cross-validation methods, to very computationally efficient linear methods. The methods are able to account for interrelations between parameters, but some argue that because linear methods neglect the effects of model nonlinearity, they are not worth considering when examining complex, nonlinear models of environmental systems. However, when faced with computationally demanding models needed to simulate, for example, climate change, the chance of obtaining fundamental insights (such as important and relationships between predictions and parameters) with few model runs is tempting. In the first part of this work, comparisons of local sensitivity analysis and cross-validation are conducted using a nonlinear groundwater model of the Maggia Valley, Southern Switzerland; sensitivity analysis are then applied to an integrated hydrological model of the same system where the impact of more processes and of using different sets of observations on the model results are considered; applicability to models of a variety of situations (climate, water quality, water management) is inferred. Results show that the frugal linear methods produced about 70% of the insight from about 2% of the model runs required by the computationally demanding methods. Regarding important observations, linear 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. The results suggest that it can be advantageous to consider local sensitivity analysis in model evaluation, possibly as a preliminary step to provide insights that can be used to improve the design of more demanding methods. This can be foreseen as a promising direction of future research where frugal and complex methods are combined to provide insights on model development and model results.

  3. Exploring the Limits to Observational Diffuse Interstellar Band Studies

    NASA Astrophysics Data System (ADS)

    Foing, B. H.

    2014-02-01

    The status of DIB research (Herbig 1995) has strongly advanced since the DIB conference in Boulder in 1994. In the same year we reported the discovery of two near IR diffuse bands coincident with C60 +, that was confirmed in subsequent years. Since then a number of DIB observational studies have been published such as DIB surveys, measurements of DIB families, correlations and environment dependences as well as DIBs in extra-galactic sources. Resolved substructures were measured and compared to predicted rotational contours of large molecules. Polarisation studies provided constraints on possible carrier molecules and upper limits. DIBs carriers have been linked with several classes of organic molecules observed in the interstellar medium, in particular to the UIR bands (assigned to PAHs), the Extended Red Emission (ERE) or the recently detected Anomalous Microwave Emission (AME, assigned to spinning dust). In particular fullerenes and PAHs have been proposed to explain some DIBs and specific molecules were searched for in DIB spectra. DIB carriers could be present in various dehydrogenation and ionization states. Experiments in the laboratory and in space contribute to our understanding of the photo-stability of possible DIB carriers. In summary, the status of DIB research in the last 20 years has strongly advanced. We review DIB observational results and their interpretation and introduce the relevant plenary discussion.

  4. 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.

  5. 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.

  6. 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

  7. Evaluation of autoimmune safety signal in observational vaccine safety studies

    PubMed Central

    Chao, Chun; Jacobsen, Steven

    2012-01-01

    Autoimmune safety evaluation is an important component of post-licensure vaccine safety evaluation. Recently, we published the findings from a large observational safety study of the quadrivalent human papillomavirus vaccine in females. From this study, based on two large managed care organizations, we have obtained some empirical data that may prove useful for the design of future vaccine safety studies within a managed care environment. For autoimmune conditions, a major challenge in vaccine safety study is to determine true incident cases in relation to the timing of vaccination. We found expert case review of medical records an indispensable component for autoimmune safety studies based on electronic health records. Case identification should also be expanded to include the use of laboratory test results or other relevant measures in addition to the disease specific ICD-9 diagnosis codes, when applicable. Furthermore, we recommend the parallel use of both safety signal evaluation that involves pattern evaluation for conditions that are more common, and statistical comparisons for conditions that are rather rare. Finally, we recommend an accompanying vaccine uptake study to understand the potential selection bias and confounding in a given study population that should be addressed with data collection and analytical techniques. PMID:22871958

  8. 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.

  9. Impact of ambient fine particulate matter carbon measurement methods on observed associations with acute cardiorespiratory morbidity.

    PubMed

    Winquist, Andrea; Schauer, Jamie J; Turner, Jay R; Klein, Mitch; Sarnat, Stefanie Ebelt

    2015-01-01

    Elemental carbon (EC) and organic carbon (OC) represent a substantial portion of particulate matter <2.5 μm in diameter (PM2.5), and have been associated with adverse health effects. EC and OC are commonly measured using the National Institute of Occupational Safety and Health (NIOSH) method or the Interagency Monitoring of Protected Visual Environments (IMPROVE) method. Measurement method differences could have an impact on observed epidemiologic associations. Daily speciated PM2.5 data were obtained from the St Louis-Midwest Supersite, and St Louis emergency department (ED) visit data were obtained from the Missouri Hospital Association for the period June 2001 to April 2003. We assessed acute associations between cardiorespiratory ED visits and EC and OC from NIOSH and IMPROVE methods using Poisson generalized linear models controlling for temporal trends and meteorology. Associations were generally similar for EC and OC from the different measurement methods. The most notable difference between methods was observed for congestive heart failure and EC (for example, warm season rate ratios (95% confidence intervals) per interquartile range change in EC concentration were: NIOSH=1.06 (0.99-1.13), IMPROVE=1.01 (0.96-1.07)). Overall, carbon measurement method had little impact on acute associations between EC, OC, and ED visits. Some specific differences were observed, however, which may be related to particle composition. PMID:25138293

  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. 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.

  12. 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)

  13. 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.

  14. The reporting of statistics in medical educational studies: an observational study

    PubMed Central

    Desbiens, Norman A

    2007-01-01

    Background There is confusion in the medical literature as to whether statistics should be reported in survey studies that query an entire population, as is often done in educational studies. Our objective was to determine how often statistical tests have been reported in such articles in two prominent journals that publish these types of studies. Methods For this observational study, we used electronic searching to identify all survey studies published in Academic Medicine and the Journal of General Internal Medicine in which an entire population was studied. We tallied whether inferential statistics were used and whether p-values were reported. Results Eighty-four articles were found: 62 in Academic Medicine and 22 in the Journal of General Internal Medicine. Overall, 38 (45%) of the articles reported or stated that they calculated statistics: 35% in Academic Medicine and 73% in the Journal of General Internal Medicine. Conclusion Educational enumeration surveys frequently report statistical tests. Until a better case can be made for doing so, a simple rule can be proffered to researchers. When studying an entire population (e.g., all program directors, all deans, and all medical schools) for factual information, do not perform statistical tests. Reporting percentages is sufficient and proper. PMID:17659082

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Pandemrix™ and narcolepsy: A critical appraisal of the observational studies.

    PubMed

    Verstraeten, Thomas; Cohet, Catherine; Dos Santos, Gaël; Ferreira, Germano Lc; Bollaerts, Kaatje; Bauchau, Vincent; Shinde, Vivek

    2016-01-01

    A link between Pandemrix™ (AS03-adjuvanted H1N1 pandemic influenza vaccine, GSK Vaccines, Belgium) and narcolepsy was first suspected in 2010 in Sweden and Finland following a number of reports in children and adolescents. Initial scepticism about the reported association faded as additional countries reported similar findings, leading several regulatory authorities to restrict the use of Pandemrix™. The authors acknowledge that currently available data suggest an increased risk of narcolepsy following vaccination with Pandemrix™; however, from an epidemiologist's perspective, significant methodological limitations of the studies have not been fully addressed and raise questions about the reported risk estimates. We review the most important biases and confounders that potentially occurred in 12 European studies of the observed association between Pandemrix™ and narcolepsy, and call for further analyses and debate. PMID:26379011

  20. 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.

  1. 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

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

    PubMed

    Vandenbroucke, Jan P; von Elm, Erik; Altman, Douglas G; Gtzsche, 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

  3. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): Explanation and Elaboration

    PubMed Central

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

    2007-01-01

    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:17941715

  4. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  6. Melt-Triggered Seismic Response in Hydraulically-Active Polar Ice: Observations and Methods

    NASA Astrophysics Data System (ADS)

    Carmichael, Joshua D.

    Glacier ice responds to environmental forcing through changes in its sliding speed and mass balance. While these changes often occur on daily time scales or longer, they are initiated by brittle deformation events that establish hydrological pathways in hours or seconds and allow meltwater access to englacial or subglacial depths to facilitate ice motion. In this thesis, we (various contributing authors including myself) use seismic monitoring to detect and locate the creation and growth of some of these hydraulic pathways by monitoring their seismic emissions, or icequakes. More specifically, we address (1) what seismic observables, unavailable from other sensing methods, indicate an initial glaciogenic response to melt- water input and (2) if these comprise evidence of feedbacks that may destabilize polar ice under a warming climate. Supplemental to our scientific contributions, we advance statistical processing methods that demonstrably improve the capability of digital detectors at discriminating icequakes from astationary noise. We begin by interpreting geophysical observations collected from a dry-based, sub-freezing (--17 C), polar glacier environment (Taylor Glacier, ANT). By implementing a calibrated surface energy balance model, we estimate the timing and volume of surface meltwater generated during the collection of seismic data from a six-receiver geophone network. We proceed by contrasting these response characteristics with geophysical observations following an early (spring) supraglacial lake drainage within the lake-forming ablation zone of the Western Greenland Ice Sheet. Using measurements from a 5km-aperture geophone network, we find that the anticipated post-drainage icequakes are diurnally responsive, largely surficial in origin, and indicative of tensile fracturing from shallow cracks in the ice. The creation of the lake-drainage moulin appears to coincide with a shift in mean icequake source locations, and an increase in icequake occurrence at night relative to that in the day. Contrary to our expectations, we find that the timing of GPS-derived surface speeds do not clearly indicate this seismic activity on any given day. Rather, these icequakes are best explained by peaks in localized strain gradients that develop at night when decreased subglacial water flux likely increases variability in basal traction. Additionally, our results appear comprise the first detailed seismic observations targeted at an actively draining lake. Our last study addresses the apparent deficiency in observed basal icequakes detected from Greenland lake site. To explain the lack of deep icequakes, we compute thresholds on the magnitude of detectable basal events within the network and thereby illustrate that surficial icequakes with similar magnitudes and spectral content are more likely to be observed. By restricting our attention to seismic events that produce lower frequency waveforms, we find a population of nearly monochromatic, sub-1Hz, large magnitude ( M w ? 3) seismic events borne from remote glaciogenic sources. In contrast to surficial icequakes, these events occur without significant bias between day and/or night periods and are best explained as glacial earthquakes generated by sliding episodes or iceberg calving events in the vicinity of Jakobshavn Glacier. These events occur daily and not correlate with the presence of local, surficial seismicity. We conclude with three general assertions regarding melt-triggered response characteristics of polar ice. First, hydraulic connections established by fracture events do not necessarily result in seismogenic basal stick slip, and therefore cannot necessarily be observed with conventional GPS monitoring. This was demonstrated at Taylor Glacier. Here, meltwater input to a hydraulic pathway led to fracture growth deep within a cold glacier without any change in surface speed. Second, the presence of melt-triggered basal sliding does not necessarily induce a clear seismogenic basal response in the lakes regions. This was demonstrated on the Greenland Ice Sheet. Seismogenesis may instead be more clearly reflected by surficial strain gradients established by variability in basal traction, suggesting these feedbacks are secondary rather than primary. The response is therefore not clearly indicated from day-to-day timing of GPS-observations. Third, the absence of an observed local response does not necessarily indicate the absence of a local physical response. This was also illustrated in Greenland. Here, deep local icequakes are likely muted by noise, waveform-attenuating ice, and viscous basal rheology. Magnitude thresholds suggest that M w ? 2 for consistent recording of local, basal sources. In contrast, remote, low frequency seismic events were clearly observed, and attributed to activity within ice catchments along the western edge of the ice sheet or Jacobshavn glacier. Finally, we assert that early-indicators of melt-triggered glacial response include components of spatially localized, brittle deformation that is most suitable to seismic observation. Critically-stable regions along mass-balance equilibrium lines constitute potential sites for newly forming surface-to-bed hydraulic connections in a warming climate, and likewise, a potential target for future seismic experiments.

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

    PubMed Central

    2012-01-01

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

  8. Arctic Sea ice studies with passive microwave satellite observations

    NASA Technical Reports Server (NTRS)

    Cavalieri, D. J.

    1988-01-01

    The objectives of this research are: (1) to improve sea ice concentration determinations from passive microwave space observations; (2) to study the role of Arctic polynyas in the production of sea ice and the associated salinization of Arctic shelf water; and (3) to study large scale sea ice variability in the polar oceans. The strategy is to analyze existing data sets and data acquired from both the DMSP SSM/I and recently completed aircraft underflights. Special attention will be given the high resolution 85.5 GHz SSM/I channels for application to thin ice algorithms and processes studies. Analysis of aircraft and satellite data sets is expected to provide a basis for determining the potential of the SSM/I high frequency channels for improving sea ice algorithms and for investigating oceanic processes. Improved sea ice algorithms will aid the study of Arctic coastal polynyas which in turn will provide a better understanding of the role of these polynyas in maintaining the Arctic watermass structure. Analysis of satellite and archived meteorological data sets will provide improved estimates of annual, seasonal and shorter-term sea ice variability.

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

    PubMed

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

    2012-09-01

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

  10. Statistical methods for studying disease subtype heterogeneity.

    PubMed

    Wang, Molin; Spiegelman, Donna; Kuchiba, Aya; Lochhead, Paul; Kim, Sehee; Chan, Andrew T; Poole, Elizabeth M; Tamimi, Rulla; Tworoger, Shelley S; Giovannucci, Edward; Rosner, Bernard; Ogino, Shuji

    2016-02-28

    A fundamental goal of epidemiologic research is to investigate the relationship between exposures and disease risk. Cases of the disease are often considered a single outcome and assumed to share a common etiology. However, evidence indicates that many human diseases arise and evolve through a range of heterogeneous molecular pathologic processes, influenced by diverse exposures. Pathogenic heterogeneity has been considered in various neoplasms such as colorectal, lung, prostate, and breast cancers, leukemia and lymphoma, and non-neoplastic diseases, including obesity, type II diabetes, glaucoma, stroke, cardiovascular disease, autism, and autoimmune disease. In this article, we discuss analytic options for studying disease subtype heterogeneity, emphasizing methods for evaluating whether the association of a potential risk factor with disease varies by disease subtype. Methods are described for scenarios where disease subtypes are categorical and ordinal and for cohort studies, matched and unmatched case-control studies, and case-case study designs. For illustration, we apply the methods to a molecular pathological epidemiology study of alcohol intake and colon cancer risk by tumor LINE-1 methylation subtypes. User-friendly software to implement the methods is publicly available. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26619806

  11. A study of GPS ionospheric scintillations observed at Guilin

    NASA Astrophysics Data System (ADS)

    Zou, Yuhua; Wang, Dongli

    2009-12-01

    The occurrence of strong ionospheric scintillations with S4>=0.2 was studied using global positioning system (GPS) measurements at Guilin (25.29N, 110.33E; geomagnetic: 15.04N, 181.98E), a station located near the northern crest of equatorial anomaly in China. The results are presented for data collected from January 2007 to December 2008. The results show that amplitude scintillations occurred only during the first five months of the considered years. Nighttime amplitude scintillations, observed mainly in the south of Guilin, always occurred with phase scintillations, total electron content (TEC) depletions, and Rate Of change of TEC (ROT) fluctuations. However, TEC depletions and ROT fluctuations were weak during daytime amplitude scintillations, and daytime amplitude scintillations usually occurred in most of the azimuth directions. GPS scintillation/TEC observations recorded at Guilin and signal-to-noise-ratio measurements obtained from GPS-COSMIC radio occultation indicate that nighttime and daytime scintillations are very likely caused by ionospheric F region irregularities and sporadic E, respectively.

  12. 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

  13. 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.

  14. 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.

  15. Observational Studies of Pre-Main Sequence Stars

    NASA Astrophysics Data System (ADS)

    Hutchinson, M. G.

    1988-12-01

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

  16. A nephrology guide to reading and using systematic reviews of observational studies.

    PubMed

    Ravani, Pietro; Ronksley, Paul E; James, Matthew T; Strippoli, Giovanni F

    2015-10-01

    Systematic reviews are an ideal way of summarizing evidence from primary studies. While systematic reviews of randomized trials are broadly used to summarize benefits and harms of interventions, systematic reviews of observational studies are useful to summarize data on prevalence of risk factors in a population, distribution of outcomes or associations of different risk factors with outcomes. Also, systematic reviews can be useful to clarify potential reasons for conflicting data found in primary studies and explore sources of heterogeneity (variation in primary study data) to better understand epidemiological data and generate hypotheses for candidate interventions to improve outcomes. Summarizing data from observational studies in systematic reviews is a powerful tool to distil existing prognostic evidence in specific settings and inform patients and healthcare providers. In this article, we describe how to critically appraise the methods, interpret the results and apply the findings of a systematic review of observational (prognostic) studies. PMID:26113546

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

    NASA Technical Reports Server (NTRS)

    Gelaro, Ronald; Langland, Rolf; Todling, Ricardo

    2009-01-01

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

  18. Comparison of Columnar Water Vapor Measurements During The Fall 1997 ARM Intensive Observation Period: Optical Methods

    NASA Technical Reports Server (NTRS)

    Schmid, Beat; Michalsky, J.; Slater, D.; Barnard, J.; Halthore, R.; Liljegren, J.; Holben, B.; Eck, T.; Livingston, J.; Russell, P.; Hipskind, R. Stephen (Technical Monitor)

    2000-01-01

    In the fall of 1997 the Atmospheric Radiation Measurement (ARM program conducted an intensive Observation Period (IOP) to study water vapor at its Southern Great Plains (SGP) site. Among the 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 solar transmittance in the 0.94-micrometer water vapor absorption band. As one of the steps in the CWV retrievals the aerosol component is subtracted from the total transmittance, in the 0.94-micrometer band. The aerosol optical depth comparisons among the same four radiometers are presented elsewhere. We have used three different methods to retrieve CWV. Without attempting to standardize on the same radiative transfer model and its underlying water vapor spectroscopy we found the CWV to agree within 0.13 cm (rms) for CWV values ranging from 1 to 5 cm. Preliminary results obtained when using the same updated radiative transfer model with updated spectroscopy for all instruments will also be shown. Comparisons to the microwave radiometer results will be included in the comparisons.

  19. Formal Methods Case Studies for DO-333

    NASA Technical Reports Server (NTRS)

    Cofer, Darren; Miller, Steven P.

    2014-01-01

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

  20. Evidence of clinical competence by simulation, a hermeneutical observational study.

    PubMed

    Lejonqvist, Gun-Britt; Eriksson, Katie; Meretoja, Riitta

    2016-03-01

    Making the transition from theory to practise easier in nursing education through simulation is widely implemented all over the world, and there is research evidence of the positive effects of simulation. The pre-understanding for this study is based on a definition of clinical competence as encountering, knowing, performing, maturing and developing, and the hypothesis is that these categories should appear in simulated situations. The aim of the study was to explore the forms and expressions of clinical competence in simulated situations and furthermore to explore if and how clinical competence could be developed by simulation. An observational hermeneutic study with a hypothetic-deductive approach was used in 18 simulated situations with 39 bachelor degree nursing students. In the situations, the scenarios, the actors and the plots were described. The story told was "the way from suffering to health" in which three main plots emerged. The first was, doing as performing and knowing, which took the shape of knowing what to do, acting responsibly, using evidence and equipment, appearing confident and feeling comfortable, and sharing work and information with others. The second was, being as encountering the patient, which took the shape of being there for him/her and confirming by listening and answering. The third plot was becoming as maturing and developing which took the shape of learning in co-operation with other students. All the deductive categories, shapes and expressions appeared as dialectic patterns having their negative counterparts. The study showed that clinical competence can be made evident and developed by simulation and that the challenge is in encountering the patient and his/her suffering. PMID:26763209

  1. 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)

  2. Alternative methods for specification of observed forcing in single-column models and cloud system models

    NASA Astrophysics Data System (ADS)

    Randall, David A.; Cripe, Douglas G.

    1999-10-01

    We discuss alternative methods for prescribing advective tendencies in single-column models (SCMs) and cloud system models. These include "revealed forcing," in which the total advective tendency is prescribed from observations; "horizontal advective forcing," in which the horizontal advective tendencies are prescribed, together with the observed vertical motion which is combined with the predicted sounding to determine the tendencies due to vertical advection; and "relaxation forcing," in which the horizontal advective tendencies are computed by relaxing the sounding toward the observed upstream sounding, with a relaxation timescale determined by the time required for the wind to carry parcels across the grid column. When relaxation forcing is used, the horizontal advective tendencies can be diagnosed from the model output and compared with the corresponding observed tendencies. We present SCM results to illustrate these three forcing methods, based on data from several field experiments in both the tropics and the midlatitudes. Each method is shown to have its strengths and weaknesses. Overall, the results presented here do not show unambiguous differences between revealed forcing and horizontal advective forcing. The two methods appear to be generally comparable. Revealed forcing may therefore be preferred for its simplicity. Relaxation forcing guarantees realistic soundings of the state variables but can produce large errors in parameterized processes which are driven by rates (e.g., fluxes) rather than states. In particular, relaxation forcing gives large errors in the precipitation rate in this model. We demonstrate that relaxation forcing leads to unrealistically high (low) precipitation in versions of the model which tend to produce unrealistically dry (humid) soundings. The observed horizontal advective tendencies in the tropics are so weak, especially for temperature, that small absolute errors in the diabatic tendencies diagnosed with relaxation forcing can lead to large relative errors in the diagnosed horizontal advective tendencies.

  3. 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).

  4. 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

  5. Phytoplankton dynamics studying using observation and biophysical modeling

    NASA Astrophysics Data System (ADS)

    Xu, Yi

    Continental shelf phytoplankton bloom dynamics are associated with meteorological, oceanographic and coastal forcing mechanisms. Mixing related to stratification and de-stratification is a key process of the physical environment that can control the timing and magnitude of blooms. Using data from satellite, coastal ocean observatory and bio-physical model, this study investigated the seasonal and decadal variability of chlorophyll in the Mid-Atlantic Bight and how different forcing mechanisms affect the phytoplankton bloom. The temporal and spatial distribution of chlorophyll a in the MAB was quantified using satellite data collected by the Sea-viewing Wide Field of view Sensor (SeaWiFS). The MAB undergoes a fall-winter bloom in the middle-outer shelf region and spring bloom in the shelf-break region. The interannual variability of bloom magnitude is associated with wind-induced mixing. Mixing has been recognized as having an important role in influencing underwater light and nutrient budgets and thus regulating phytoplankton bloom. The ratio of light over mixed layer depth (MLD) was used to determine the trade-off effects of mixing on phytoplankton bloom activity. We find that a critical light value around 60 (W m-2) for the shelf region and 150 (W m-2) for the shelf-break front region in promoting maximum phytoplankton biomass and there is a predictable linear regression relationship between the critical light value and depth. The bio-physical model identified the wind-induced mixing, net heat flux and river run-off are the most important factors influencing water column stability. Sensitivity studies showed that the timing of the destratification and initiation of fall bloom was closely related to the wind forcing. The river's role in bringing buoyancy was significant in increasing phytoplankton bloom. The decadal declines in the seasonal satellite estimates of chlorophyll a&barbelow; concentrations have been observed in the fall and winter in the MAB and are hypothesized to reflect shifts in the Atlantic Multidecadal Oscillation (AMO) that alters wind stress, river discharge, and net heat flux. This work prototypes the integration of observation and modeling in a coastal environment and demonstrates the use of 3D coupled physical-biological model forced with realistic atmospheric forcing to study the phytoplankton dynamics in the MAB.

  6. 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.

  7. 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.

  8. 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

  9. The overlapping plates method applied to CCD observations of 243 Ida

    NASA Technical Reports Server (NTRS)

    Owen, W. M., Jr.; Yeomans, D. K.

    1994-01-01

    The overlapping plates method has been applied to crossing-point Charge Coupled Device (CCD) observations of minor planet 243 Ida to produce absolute position measurements precise to better than 0.1 sec and differential position measurements precise to better than 0.06 sec. Although these observations numbered only 17 out of the 520 that produced the final ground-based Ida ephemeris for the Galileo spacecraft flyby, their inclusion decreased Ida's downtrack error from 78 to 60 km and its out-of-plane error from 58 to 44 km.

  10. 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).

  11. 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.

  12. [A clinical study on urethral recurrence observed after cystectomy].

    PubMed

    Yasumoto, R; Asakawa, M; Yoshihara, H; Sakamoto, W; Iseki, T; Nakatani, T; Wada, S; Kishimoto, T; Maekawa, M

    1990-10-01

    A clinical study was made on 108 male patients who underwent cystectomy. The posterior urethra and partial anterior urethra were removed in 47 cases, half of the perpendicular urethra was removed in 13 cases and the anterior urethra up to the fossa navicularis was removed in 48 cases. Out of 60 cases without urethrectomy, urethral recurrence was observed in 13 cases (21.7%), while no recurrence was observed in the cases treated with urethrectomy. The average period of time from cystectomy to urethral recurrence was 24.7 months (11-39 months). Urethral cancer of such early stages as pIa and pIb were found in 3 and 6 cases, respectively. Stage pT2 was found in 4 cases. Grade 1 cancer was found in 3 cases, grade 2, in 5 cases, and 3 in 5 cases. The proximal end of the perpendicular urethra was found to be the most frequent site for recurrence with 11 cases exhibiting recurrence at this location and 2 cases at the mid-portion of the perpendicular urethra. Many cases exhibited multiple recurrence of tumor of visually grayish, velvety and non-papillary type which was histologically all transitional cell carcinoma. Bladder tumor with higher grade tended to cause urethral cancer recurrence with higher grade. Bladder tumors at multiple locations from the trigone to the lateral and posterior walls tended to cause recurrence in the urethra (p less than 0.05). Of all the cases, 10 cases underwent urethrectomy and 2 cases penectomy. 12 cases received chemotherapy and 5 cases radiation therapy as postoperative adjuvant treatments.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2273704

  13. Why Rudolphs nose is red: observational study

    PubMed Central

    2012-01-01

    Objective To characterise the functional morphology of the nasal microcirculation in humans in comparison with reindeer as a means of testing the hypothesis that the luminous red nose of Rudolph, one of the most well known reindeer pulling Santa Clauss sleigh, is due to the presence of a highly dense and rich nasal microcirculation. Design Observational study. Setting Troms, Norway (near the North Pole), and Amsterdam, the Netherlands. Participants Five healthy human volunteers, two adult reindeer, and a patient with grade 3 nasal polyposis. Main outcome measures Architecture of the microvasculature of the nasal septal mucosa and head of the inferior turbinates, kinetics of red blood cells, and real time reactivity of the microcirculation to topical medicines. Results Similarities between human and reindeer nasal microcirculation were uncovered. Hairpin-like capillaries in the reindeers nasal septal mucosa were rich in red blood cells, with a perfused vessel density of 20 (SD 0.7) mm/mm2. Scattered crypt or gland-like structures surrounded by capillaries containing flowing red blood cells were found in human and reindeer noses. In a healthy volunteer, nasal microvascular reactivity was demonstrated by the application of a local anaesthetic with vasoconstrictor activity, which resulted in direct cessation of capillary blood flow. Abnormal microvasculature was observed in the patient with nasal polyposis. Conclusions The nasal microcirculation of reindeer is richly vascularised, with a vascular density 25% higher than that in humans. These results highlight the intrinsic physiological properties of Rudolphs legendary luminous red nose, which help to protect it from freezing during sleigh rides and to regulate the temperature of the reindeers brain, factors essential for flying reindeer pulling Santa Clauss sleigh under extreme temperatures. PMID:23247980

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

    PubMed Central

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

    2014-01-01

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

  15. 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.

  16. 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

  17. Quantifying natural variability as a method to detect environmental change: Definitions of the normal range for a single observation and the mean of m observations.

    PubMed

    Barrett, Timothy J; Hille, Kelly A; Sharpe, Rainie L; Harris, Katherine M; Machtans, Hilary M; Chapman, Peter M

    2015-05-01

    The normal range has been defined as the range that encloses 95% of reference values; in practice this range has been defined as the reference mean??2 standard deviations (SD). When sample sizes are small and reference data are not normally distributed, the mean??2 SDs do not enclose 95% of data values. Prediction intervals (PI) calculated using sample statistics are used in the present study to define the normal range for a single observation and the mean of m observations. The PIs provide confidence limits for the next randomly selected observation (or mean of m observations) from a population. The PIs are defined using normally distributed reference data; normality can typically be achieved with transformations of the data. Covariates can be used to explain some of the variability in the reference distribution, increasing the ability to detect change. When assumptions of normality are not met, alternative methods of defining the normal range are provided. The normal range can be used to quantify natural variability and assess change from the reference distribution. It can be used as an early warning indicator of change in environmental monitoring to identify the need for further investigation. PMID:25655985

  18. An accuracy measurement method for star trackers based on direct astronomic observation.

    PubMed

    Sun, Ting; Xing, Fei; Wang, Xiaochu; You, Zheng; Chu, Daping

    2016-01-01

    Star tracker is one of the most promising optical attitude measurement devices and it is widely used in spacecraft for its high accuracy. However, how to realize and verify such an accuracy remains a crucial but unsolved issue until now. The authenticity of the accuracy measurement method of a star tracker will eventually determine the satellite performance. A new and robust accuracy measurement method for a star tracker based on the direct astronomical observation is proposed here. In comparison with the conventional method with simulated stars, this method utilizes real navigation stars as observation targets which makes the measurement results more authoritative and authentic. Transformations between different coordinate systems are conducted on the account of the precision movements of the Earth, and the error curves of directional vectors are obtained along the three axes. Based on error analysis and accuracy definitions, a three-axis accuracy evaluation criterion has been proposed in this paper, which could determine pointing and rolling accuracy of a star tracker directly. Experimental measurements confirm that this method is effective and convenient to implement. Such a measurement environment is close to the in-orbit conditions and it can satisfy the stringent requirement for high-accuracy star trackers. PMID:26948412

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

    PubMed Central

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

    2012-01-01

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

  20. 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...

  1. A semiquantitative method for enumerating and observing parasites and predators of soil nematodes.

    PubMed

    Mankau, R

    1975-04-01

    A laboratory method was developed to count and observe antagonists of soil nematodes and simulate their relationships in the soil. A 10- to 25-cc soil sample is suspended in water and washed through a series of small standard sieves. Residues are washed into a small beaker and collected on a 24-mm filter paper disk in a filter holder under vacuum. The disk is placed on corn meal agar in a petri dish. Microfauna and flora present in the sample colonize the organic matter on the disk and move onto and into the agar where they can be observed easily. Distinct successions of organisms usually occur and within 6-18 days or more, parasites and predators of nematodes are often abundant, especially nematode-trapping fungi. Counting predation events and parasitized nematodes in replicate dishes after specific incubation periods allows quantitative comparisons between soil samples. The method has distinct advantages over others for enumerating organisms which attack nematodes. PMID:19308144

  2. 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.

  3. Alcohol-Related Fracture Admissions: A Retrospective Observational Study

    PubMed Central

    Kelly, G; Thompson, NW

    2015-01-01

    Introduction In April 2011 the NI public health agency estimated that alcohol misuse generates overall annual healthcare costs of £122.2m. There is currently a paucity of data regarding the burden of alcohol-related fractures on the provinces Trauma and Orthopaedic service. Patients and Methods A retrospective review of 104 patients over a 12 month period was performed. Data collected using the Fractures Outcomes and Research Database included: age, gender, smoking status, weekly alcohol intake, mechanism of injury and subsequent treatment. Results Alcohol related fractures accounted for 6.1% of all acute fractures admissions in the 12 month period. 73% were male, with a bimodal age distribution. The majority of patients were classed as social drinkers; however a significant proportion (23.1%) were alcohol dependent. 62.5% of patients were smokers at the time of admission. 95% of patients suffered a single injury which was commonly secondary to a simple mechanical fall (53.8%). The majority of patients sustained lower limb injuries, with 30.8% of these being ankle fractures. Conclusion In conclusion, our study has identified that alcohol-related trauma creates a significant financial burden on the NHS. It is likely that the incidence of alcohol related fracture is higher than documented in this study. We advocate the assessment of patients using the AUDIT-C score to assess for at risk drinking behaviour in those presenting with an alcohol related fracture. PMID:26170483

  4. 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.

  5. 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.

  6. 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

  7. Dalfampridine in patients with downbeat nystagmus--an observational study.

    PubMed

    Claassen, Jens; Feil, Katharina; Bardins, Stanislav; Teufel, Julian; Spiegel, Rainer; Kalla, Roger; Schneider, Erich; Jahn, Klaus; Schniepp, Roman; Strupp, Michael

    2013-08-01

    We investigated the effects of dalfampridine, the sustained-release form of 4-aminopyridine, on slow phase velocity (SPV) and visual acuity (VA) in patients with downbeat nystagmus (DBN) and the side effects of the drug. In this proof-of-principle observational study, ten patients received dalfampridine 10 mg bid for 2 weeks. Recordings were conducted at baseline, 180 min after first administration, after 2 weeks of treatment and after 4 weeks of wash-out. Mean SPV decreased from a baseline of 2.12 deg/s 1.72 (mean SD) to 0.51 deg/s 1.00 180 min after first administration of dalfampridine 10 mg and to 0.89 deg/s 0.75 after 2 weeks of treatment with dalfampridine (p < 0.05; post hoc both: p < 0.05). After a wash-out period of 1 week, mean SPV increased to 2.30 deg/s 1.6 (p < 0.05; post hoc both: p < 0.05). The VA significantly improved during treatment with dalfampridine. Also, 50 % of patients did not report any side effects. The most common reported side effects were abdominal discomfort and dizziness. Dalfampridine is an effective treatment for DBN in terms of SPV. It was well-tolerated in all patients. PMID:23589193

  8. Observed wave characteristics during growth and decay: a case study

    NASA Astrophysics Data System (ADS)

    Prasada Rao, C. V. K.; Baba, M.

    1996-10-01

    Observed 1-h time series data on sea surface waves in the shelf waters off Goa, west coast of India (depth 80 m), during 17-24 March 1986, are analyzed with reference to the prevailing synoptic winds to understand wave growth and decay aspects. Wind speeds ( U10) ranged from 0 to 11.5 m s -1, whereas significant wave height ( Hs) varied between 0.6 and 2.3 m. Cross-correlation analysis between U10 and Hs revealed a time-lag of 4 h. A relationship is obtained between wave steepness ( H s/L ) and wave age ( C/U10) viz. Log 10( H s/L = -0.53 Log 10( C/U 10) - 1.385. Phillips' hypothesis of f-5 formula for equilibrium range of wave spectrum and relationship between non-dimensional energy ( E * = Eg 2/U *4) and non-dimensional peak frequency ( v * = U *f m/g ) are studied. Correlation of non-dimensional wave parameters ( E * and v *) using the present data showed a better aereement with Hasselmann et al. (1976) when comnared to Toba (1978).

  9. Observational Buoy Studies of Coastal Air-Sea Fluxes.

    NASA Astrophysics Data System (ADS)

    Frederickson, Paul A.; Davidson, Kenneth L.

    2003-02-01

    Recent advancements in measurement and analysis techniques have allowed air-sea fluxes to be measured directly from moving platforms at sea relatively easily. These advances should lead to improved surface flux parameterizations, and thus to improved coupled atmosphere-ocean modeling. The Naval Postgraduate School has developed a `flux buoy' (FB) that directly measures air-sea fluxes, mean meteorological parameters, and one-dimensional and directional wave spectra. In this study, the FB instrumentation and data analysis techniques are described, and the data collected during two U.S. east coast buoy deployments are used to examine the impact of atmospheric and surface wave properties on air-sea momentum transfer in coastal ocean regions. Data obtained off Duck, North Carolina, clearly show that, for a given wind speed, neutral drag coefficients in offshore winds are higher than those in onshore winds. Offshore wind drag coefficients observed over the wind speed range from 5 to 21 m s1 were modeled equally well by a linear regression on wind speed, and a Charnock model with a constant of 0.016. Measurements from an FB deployment off Wallops Island, Virginia, show that neutral drag coefficients in onshore winds increase as the wind-wave direction differences increase, especially beyond ±60°.

  10. A European Network for Atmospheric Hydrogen observations and studies: EUROHYDROS

    NASA Astrophysics Data System (ADS)

    Werner, A.; Engel, A.

    2008-12-01

    and the EuroHydros team In a future energy supply chain, molecular hydrogen is expected to play an increasingly important role as a carrier of energy for mobile applications, in particular in the automotive sector. Such an increased use of molecular hydrogen is prone to lead to additional emissions into the atmosphere, due to leakages in the supply chain. While molecular hydrogen does not influence the radiation budget of the atmosphere directly, it affects its oxidation capacity, through reaction with the OH radical. This in turn leads to an increased atmospheric lifetime of many atmospheric constituents (e.g. Methane), making H2 an indirect greenhouse gas. An increase of molecular hydrogen in the atmosphere also leads to increasing H2O in the stratosphere, influencing the radiation budget of the atmosphere and ozone chemistry. In the light of these uncertainties, a thorough understanding of hydrogen in the atmosphere is necessary, and, most notably, a good understanding of the present day global distribution and budget of atmospheric hydrogen. The EU funded project Eurohydros aims at improving the understanding of the budget of molecular hydrogen in the atmosphere through a combination of atmospheric monitoring, source-sink studies and modelling work. In this presentation we focus on the observational network, showing first results from different European and Global sites, from the calibration of the data sets and a first intercomparison experiment.

  11. 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.

  12. A new method for electron microscopic observation of isolated synaptic vesicles labelled with monoclonal antibody.

    PubMed

    Nishiye, H; Obata, K; Ozaki, T; Uchizono, K

    1988-08-01

    The immunoreaction of a monoclonal antibody (Mab) and an isolated synaptic vesicle (SV) was processed on a grid mesh and the result could be easily observed with electron microscopy. The SV suspension was obtained and dispersed on the grid mesh where immunoreaction procedures were performed. The resulting immunoreaction was visualized by labelling with ferritin particle (FAD) or horseradish peroxidase (HRP) for the electron microscopic observation. The SV specimen was observed by electron microscopy after faint negative staining with 1% uranyl acetate. With this method, the positive immunoreaction of Mab 171B5 and the isolated SV could be easily identified by the formation of a halo of FAD or a cobweb of HRP surrounding the SV. In the control experiment, the SV specimen was incubated with normal mouse serum instead of the Mab while the other procedures were performed in the same way. The SV was not outlined by FAD in the control experiment. Thus, the positive immunoreaction of the Mab and SV was thought to be an immunologically specific one. It was also determined that the Mab reacted specifically with the SV but not with the small membrane fragments and other unknown material. The present method seems to be useful for observing the immunoreaction of subcellular structures and their antibodies under electron microscopy. PMID:3173813

  13. Cherenkov ? shower earth-skimming method for PeV-EeV ?? observation with Ashra

    NASA Astrophysics Data System (ADS)

    Asaoka, Yoichi; Sasaki, Makoto

    2013-01-01

    We describe a method of observation for PeV-EeV ? neutrinos using Cherenkov light from the air showers of decayed ?s produced by ? neutrino interactions in the Earth. Aiming for the realization of neutrino astronomy utilizing the Earth-skimming ? neutrino detection technique, highly precise determination of arrival direction is key due to the following issues: (1) clear identification of neutrinos by identifying those vertices originating within the Earth's surface and (2) identification of very high energy neutrino sources. The Ashra detector uses newly developed light collectors which realize both a 42-diameter field-of-view and arcminute resolution. Therefore, it has superior angular resolution for imaging Cherenkov air showers. In this paper, we estimate the sensitivity of and cosmic-ray background resulting from application of the Ashra-1 Cherenkov ? shower observation method. Both data from a commissioning run and a long-term observation (with fully equipped trigger system and one light collector) are presented. Our estimates are based on a detailed Monte Carlo simulation which describes all relevant shower processes from neutrino interaction to Cherenkov photon detection produced by ? air showers. In addition, the potential to determine the arrival direction of Cherenkov showers is evaluated by using the maximum likelihood method. We conclude that the Ashra-1 detector is a unique probe into detection of very high energy neutrinos and their accelerators.

  14. 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 (19981999) 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

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

    PubMed

    Adamik, Barbara; Zielinski, Stanislaw; Smiechowicz, Jakub; Kbler, 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 24h. Endotoxin elimination was performed using hemoperfusion with the Alteco LPS Adsorber. The primary endpoint was improvement in organ function within the first 24h 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 24h 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 80mm 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 24h 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. 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.

  17. 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

  18. 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

  19. A ``local observables'' method for wave mechanics applied to atomic hydrogen

    NASA Astrophysics Data System (ADS)

    Bowman, Peter J.

    2008-12-01

    An alternative method of deriving the values of the observables of atomic systems is presented. Rather than using operators and eigenvalues the local variables method uses the continuity equation together with current densities derived from wave functions that are solutions of the Dirac or Pauli equation. The method is applied to atomic hydrogen using the usual language of quantum mechanics rather than that of geometric algebra with which the method is often associated. The picture of the atom that emerges is one in which the electron density as a whole is rotating about a central axis. The results challenge some assumptions of conventional quantum mechanics. Electron spin is shown to be a property of the dynamical motion of the electron and not an intrinsic property of the electron, the ground state of hydrogen is shown to have an orbital angular momentum of ?, and excited states are shown to have angular momenta that are different from the eigenvalues of the usual quantum mechanical operators. The uncertainty relations are found not to be applicable to the orthogonal components of the angular momentum. No double electron spin gyromagnetic ratio is required to account for the observed magnetic moments, and the behavior of the atom in a magnetic field is described entirely in kinetic terms.

  20. Determining the orientation of the observed object in threedimensional space using stereo vision methods

    NASA Astrophysics Data System (ADS)

    Ponomarev, S.

    2014-09-01

    The task of matching image of an object with its template is central for many optoelectronic systems. Solution of the matching problem in three-dimensional space in contrast to the structural alignment in the image plane allows using a larger amount of information about the object for determining its orientation, which may increase the probability of correct matching. In the case of stereo vision methods for constructing a three-dimensional image of the object, it becomes possible to achieve invariance w.r.t. background and distance to the observed object. Only three of the orientation angle of the object relative to the camera are uncertain and require measurements. This paper proposes a method for determining the orientation angles of the observed object in three-dimensional space, which is based on the processing of stereo image sequences. Disparity map segmentation method that allows one to ensure the invariance of the background is presented. Quantitative estimates of the effectiveness of the proposed method are presented and discussed.

  1. 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.

  2. Transgenerational tobacco smoke exposure and childhood cancer: An observational study

    PubMed Central

    Ortega-Garca, Juan A; Martin, Marlene; Lpez-Fernndez, Mara T; Fuster-Soler, Jose L; Donat-Colomer, Joaqun; Lpez-Ibor, Blanca; Claudio, Luz; Ferrs-Tortajada, Josep

    2011-01-01

    Aim Although tobacco smoke is an established risk factor for adult cancer, studies of the association between parental smoking and childhood cancer have produced inconsistent results. To investigate the transgenerational relationship between pre-natal and post-natal tobacco smoke exposure from the grandmothers pregnancies until after the post-natal period and childhood cancer. Methods Exposure to tobacco smoke was recorded for three generations. Data were collected through personal interviews using the paediatric environmental history, and were compared among 128 children with cancer and 128 matched controls. The contingency tables and a logistic multivariable regression model were used to control for possible confounding factors. Results Smoke exposure during oogenesis (maternal grandmother smokers) odds ratio (OR) 2.2 (95% confidence interval (CI) 1.14.9) and during the mother pregnancies OR 1.8 (95% CI 1.13.3) were significantly associated with an increased risk of childhood cancer. Conclusions Tobacco smoke exposure during the grandmothers and mothers pregnancies increase the risk of cancer in the descendants. The results suggest that the biological plausibility of the association between parental smoking and paediatric cancer can be explained by the large latency period of paediatric carcinogenesis. PMID:20412413

  3. Temporomandibular Disorders in Burning Mouth Syndrome Patients: An Observational Study

    PubMed Central

    Corsalini, Massimo; Di Venere, Daniela; Pettini, Francesco; Lauritano, Dorina; Petruzzi, Massimo

    2013-01-01

    BACKGROUND: Burning Mouth Syndrome (BMS) is a chronic disease characterized by absence of any lesions and burning of the oral mucosa associated to a sensation of dry mouth and/or taste alterations. The purpose of our study is to estimate signs and symptoms of Temporomandibular Disorders (TMD) in patients with BMS and to investigate for the existence of an association between BMS and TMD. MATERIALS AND METHODS: Forty-four BMS patients were enrolled; BMS subtype was established according to the classification of Lamey. After a gnathological evaluation, according to the protocol of the European Academy of Craniomandibular Disorders, patients were classified by RDC/TMD criteria. The data were compared and analyzed using a chi-square test to describe the existence of an association between BMS and TMD. RESULTS: 65.9% the BMS patients showed disorders classified as primary signs and symptoms of TMD according to RDC / TMD criteria, and 72.7% showed parafunctional habits. The chi-square test revealed a statistically significant association (p = 0.035) between BMS and TMD. CONCLUSION: The data suggest that there is a possible relationship not yet well understood between BMS and TMD, may be for neurophatic alterations assumed for BMS that could be also engaged in TMD pathogenesis. PMID:24273452

  4. 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.

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  6. 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.

  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. 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…

  9. 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

  10. Accuracy of physical activity assessment during pregnancy: an observational study

    PubMed Central

    2011-01-01

    Background Prenatal physical activity may improve maternal and infant health and lower future disease risk for both mother and baby; however, very few physical activity assessment methods have been validated for use during pregnancy. The purpose of this study was to evaluate the accuracy of a subjective physical activity record (PAR) and an objective activity monitor, against a reference standard to quantify moderate and vigorous physical activity (MVPA) in pregnant women. The reference standard was based on participant interviews to determine if a woman was an exerciser and confirmed with information obtained from the PAR and a heart rate monitor. Methods Fifty-two pregnant women completed a physical activity record (PAR) and wore a SenseWear Mini Armband (SWA) activity monitor over a 7-day period at 18 weeks gestation. Total minutes spent in MVPA were totaled from both modalities and evaluated against the reference standard using contingency analysis and Pearson's chi-square test to evaluate the number of women meeting minimum prenatal physical activity recommendations (at least 3, 30 minute sessions of exercise per week). Both modalities were also tested individually and collectively to assess their ability as indicators of activity using empirically determined cut-offs as indicated by receiver-operator characteristic curves. These experimentally-derived criteria were also tested with Pearson's chi-square test. Results According to the reference standard, 13 of 52 participants (25%) met the criterion of 3, 30 minute sessions of volitional, moderate-intensity activity. When compared to the reference standard, both the PAR and SWA overestimated exercise status; 42 (81%) and 52 (100%) participants, respectively, achieved 90 minutes of MVPA (P < 0.0001 for both comparisons). Single-modality predictors of MVPA did not show a significant correlation. A composite predictor of MVPA offered the most favorable option for sensitivity and specificity (true positives, n = 8 and true negatives, n = 36) using cut-offs of 280 and 385 minutes/week for the PAR and SWA, respectively. Conclusion Compared to the reference standard, time spent in MVPA obtained from the PAR or SWA overestimated the prevalence of women meeting prenatal exercise recommendations. The most accurate predictor of women meeting current prenatal exercise guidelines was identified by using the PAR and SWA collectively. PMID:22039863

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  12. A novel method for observing proteins in vivo using a small fluorescent label and multiphoton imaging

    PubMed Central

    2005-01-01

    A novel method for the fluorescence detection of proteins in cells is described in the present study. Proteins are labelled by the selective biosynthetic incorporation of 5-hydroxytryptophan and the label is detected via selective two-photon excitation of the hydroxyindole and detection of its fluorescence emission at 340nm. The method is demonstrated in this paper with images of a labelled protein in yeast cells. PMID:15946123

  13. Reducing impacts of systematic errors in the observation data on inversing ecosystem model parameters using different normalization methods

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Xu, M.; Huang, M.; Yu, G.

    2009-11-01

    Modeling ecosystem carbon cycle on the regional and global scales is crucial to the prediction of future global atmospheric CO2 concentration and thus global temperature which features large uncertainties due mainly to the limitations in our knowledge and in the climate and ecosystem models. There is a growing body of research on parameter estimation against available carbon measurements to reduce model prediction uncertainty at regional and global scales. However, the systematic errors with the observation data have rarely been investigated in the optimization procedures in previous studies. In this study, we examined the feasibility of reducing the impact of systematic errors on parameter estimation using normalization methods, and evaluated the effectiveness of three normalization methods (i.e. maximum normalization, min-max normalization, and z-score normalization) on inversing key parameters, for example the maximum carboxylation rate (Vcmax,25) at a reference temperature of 25°C, in a process-based ecosystem model for deciduous needle-leaf forests in northern China constrained by the leaf area index (LAI) data. The LAI data used for parameter estimation were composed of the model output LAI (truth) and various designated systematic errors and random errors. We found that the estimation of Vcmax,25 could be severely biased with the composite LAI if no normalization was taken. Compared with the maximum normalization and the min-max normalization methods, the z-score normalization method was the most robust in reducing the impact of systematic errors on parameter estimation. The most probable values of estimated Vcmax,25 inversed by the z-score normalized LAI data were consistent with the true parameter values as in the model inputs though the estimation uncertainty increased with the magnitudes of random errors in the observations. We concluded that the z-score normalization method should be applied to the observed or measured data to improve model parameter estimation, especially when the potential errors in the constraining (observation) datasets are unknown.

  14. Novel method of fast satellite movement information acquisition from VLBI observations

    NASA Astrophysics Data System (ADS)

    Zheng, Weimin; Yang, Yan

    2005-10-01

    Very Long Baseline Interferometry (VLBI) is a radio astronomy technique. The diameter of a VLBI synthetic telescope equals the longest baseline (>1000 Km). Therefore, VLBI can achieve very high angular resolution, and has unique advantage in the deep space tracking compared with the traditional radio ranging and Doppler tracking technologies. In the satellite VLBI observations, the spacecraft movement information such as delay or delay rate observable is very useful in the spacecraft position and orbit determination. This paper introduces an algorithm of obtaining satellite VLBI delay and delay rate based on short time correlation. Using the Differential One-way Doppler of the telemetry carrier, this method is able to complete fast fringe search, correlation, producing delay and delay rate with high accuracy from the satellite telemetry signals automatically, without any apriori orbit information. A special software correlator--Fast Fringe Searcher (FFS) was developed and successfully used in the data processing of the satellite VLBI experiments, such as the Chinese TC-1 Geospace satellite and the European SMART-1 lunar probe VLBI observations. The delay and delay rate produced by FFS were used in TC-1 orbit determination, which was the first Chinese VLBI satellite orbit determination experiment. Besides, an accurate VLBI correlator delay model can be constructed from FFS output. According to this model, a general VLBI correlator can produce more precise delay and delay rate through long time integration. This method will be applied to the real-time VLBI correlator system of the Chinese lunar exploration project in the near future.

  15. A method to improve the utilization of GNSS observation for water vapor tomography

    NASA Astrophysics Data System (ADS)

    Yao, Y. B.; Zhao, Q. Z.; Zhang, B.

    2016-01-01

    Existing water vapor tomographic methods use Global Navigation Satellite System (GNSS) signals penetrating the entire research area while they do not consider signals passing through its sides. This leads to the decreasing use of observed satellite signals and allows for no signals crossing from the bottom or edge areas especially for those voxels in research areas of interest. Consequently, the accuracy of the tomographic results for the bottom of a research area, and the overall reconstructed accuracy do not reach their full potential. To solve this issue, an approach which uses GPS data with both signals that pass the side and top of a research area is proposed. The advantages of proposed approach include improving the utilization of existing GNSS observations and increasing the number of voxels crossed by satellite signals. One point should be noted that the proposed approach needs the support of radiosonde data inside the tomographic region. A tomographic experiment was implemented using observed GPS data from the Continuously Operating Reference System (CORS) Network of Zhejiang Province, China. The comparison of tomographic results with data from a radiosonde shows that the root mean square error (RMS), bias, mean absolute error (MAE), and standard deviation (SD) of the proposed approach are superior to those of the traditional method.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. An Enhanced Observed Time Difference of Arrival Based Positioning Method for 3GPP LTE System

    NASA Astrophysics Data System (ADS)

    Won, Kyung-Hoon; Jang, Jun-Hee; Choi, Hyung-Jin

    In 3GPP (3-rd Generation Partnership Project) LTE (Long Term Evolution) system, the use of PRS (Positioning Reference Signal) for OTDOA (Observed Time Difference of Arrival) based positioning method has been agreed. However, PRSs can be overlapped at the receiver side in synchronous network because the frequency shift pattern of PRS is decided by cell ID (Identity). Moreover, in asynchronous network, the loss of orthogonality between received PRSs generates continuous interferences. Even though autonomous muting can be applied to solve the interference problems in synchronous and asynchronous networks, the muting scheme degrades the overall positioning efficiency and requires additional network complexity. Therefore, in this paper, we propose novel OTDOA based positioning methods at the receiver side to improve positioning efficiency: cancellation method of serving PRS for synchronous network, TDORS (Time Domain Orthogonal Reference Signal) generation and useful CIR (Channel Impulse Response) selection methods for asynchronous network. We verified that the proposed methods can achieve an accurate estimation and stable operation without PRS muting.

  2. Methods for studying RNA localization in bacteria.

    PubMed

    Kannaiah, Shanmugapriya; Amster-Choder, Orna

    2016-04-01

    The subcellular localization of RNA transcripts provides important insights into biological processes. Hence, understanding the mechanisms underlying RNA targeting is a high priority aim of modern cell biology. The advancements in imaging techniques, such as in situ hybridization and live-cell imaging, coupled with the evolution in optical microscopy led to the discovery that bacterial RNAs, despite the lack of nucleus, are specifically localized. Here we describe the methods used to study RNA localization in bacteria and their applications and discuss their advantages and limitations. PMID:26707207

  3. A distribution-based method to resolve single-molecule Frster resonance energy transfer observations

    PubMed Central

    Backovi?, Mihailo; Price, E. Shane; Johnson, Carey K.; Ralston, John P.

    2011-01-01

    We introduce a new approach to analyze single-molecule Frster resonance energy transfer (FRET) data. The method recognizes that FRET efficiencies assumed by traditional ensemble methods are unobservable for single molecules. We propose instead a method to predict distributions of FRET parameters obtained directly from the data. Distributions of FRET rates, given the data, are precisely defined using Bayesian methods and increase the information derived from the data. Benchmark comparisons find that the response time of the new method outperforms traditional methods of averaging. Our approach makes no assumption about the number or distribution of underlying FRET states. The new method also yields information about joint parameter distributions going beyond the standard framework of FRET analysis. For example, the running distribution of FRET means contains more information than any conceivable single measure of FRET efficiency. The method is tested against simulated data and then applied to a pilot-study sample of calmodulin molecules immobilized in lipid vesicles, revealing evidence for multiple dynamical states. PMID:21495770

  4. 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 cloud cover and bright moonlight). Furthermore, the change detection procedure only works when power blackouts happen or still persist at night at the time of an OLS overpass. In some cases (e.g. Hurricane Katrina) it has been possible to track the gradual recovery of power by repeating the procedure on nights following a disaster event. In this paper several examples of successful power blackout detection following natural disasters including hurricanes (e.g. Isabel 2003 and Wilma 2005 in the USA) and earthquakes (e.g. Gujarat Earthquake 2001 in India) will be presented, whereas overlaid hurricane paths and earthquake epicenters serve as landmarks and indicate locations around the potential highest impact. Disaster impact assessment and post-disaster research is strongly related to impacts on population, related infrastructure and activities (Kerle et al. 2005, Zhang and Kerle 2008). In particular in the case of emergency management and response humans are the main actors and first-pass assessment of affected population and locations of affected areas are essential. Space-based power blackout detection, as described above, has the potential to delineate the spatial extent of the disaster impact. Overlaying the respective OLS data with regional population data such as LandScan (Dobson et al. 2000) or Gridded Population of the World (CIESIN and CIAT 2005) allows estimating a potential number of affected people. Without a doubt such estimates comprise a considerable number of uncertainties. However, the capability of providing the information in near-real time as offered by using DMSP-OLS makes the presented approach very valuable for emergency and disaster managers worldwide. REFERENCES Center for International Earth Science Information Network CIESIN at Columbia University, and Centro Internacional de Agricultura Tropical CIAT (2005). Gridded Population of the World Version 3 (GPWv3). Palisades, NY: Socioeconomic Data and Applications Center (SEDAC), Columbia University. Available at http://sedac.ciesin.columbia.edu/gpw (last visited 01/08/2009). Dobson, J.E., E.A. Bright, P.R. Coleman, R.C. Durfee, and B.A. Worley (2000) LandScan: A Global Population Database for Estimating Populations at Risk. Photogrammetric Engineering & Remote Sensing 66(7), 849-857. Elvidge, C.D., K.E. Baugh, V.R. Hobson, E.A. Kihn, and H.W. Kroehl (1998) Detection of Fires and Power Outages Using DMSP-OLS Data. In: Lunetta, R.S., and Elvidge, C.D. (eds.) Remote Sensing Change Detection: Environmental Monitoring Methods and Applications. Ann Arbor Press, pp 123-135. Elvidge, C.D., C. Aubrecht, K. Baugh, B. Tuttle, and A.T. Howard (2007) Satellite detection of power outages following earthquakes and other events. 3rd International Geohazards Workshop. GEO & IGOS Geohazards. Proceedings. ESA/ESRIN, Frascati (Rome), Italy, November 6-9, 2007. Kerle, N., R. Stekelenburg, F. van den Heuvel, and B.G.H. Gorte (2005) Near - real time post - disaster damage assessment with airborne oblique video data. In: van Oosterom, P.J.M., Zlatanova, S., and Elfriede, M. (eds.) Geo-information for disaster management Gi4DM : Proceedings of the 1st International Symposium on Geo-Information for Disaster Management. Berlin: Springer, pp 337-353. Zhang, Y., and N. Kerle (2008) Satellite remote sensing for near-real time data collection. In: Zlatanova, S., Li, J. (eds.) Geospatial information technology for emergency response. Berlin: Springer, pp 75-102.

  5. Observing using sound and light - a short review of underwater acoustic and video-based methods

    NASA Astrophysics Data System (ADS)

    Jonsson, P.; Sillitoe, I.; Dushaw, B.; Nystuen, J.; Heltne, J.

    2009-04-01

    This paper is a review which briefly describes a selection of acoustic observation techniques and certain aspects of underwater video technology suitable for observations in an underwater environment. The review is divided into two sections, one for each subject, where each section concludes with a discussion of the current challenges within the respective fields. The acoustic section of the review covers bathymetric and geometrical measurements, imaging sonars, subsurface penetrating profilers, positioning methods, acoustic underwater communication and sensor networks, and water speed measurements. The section ends by considering temperature measurements by ocean acoustic tomography and passive acoustic monitoring. The underwater video section initially deals with questions of acquisition including underwater visibility, the type of platform, and video formats, image sensors and specialized cameras. This is followed by notes on processing techniques including mosaicking, stereo video, structured light, recording and transmission, image enhancement techniques and ends with a short discussion of underwater holographic cameras.

  6. Experimental determination of subjective similarity for pairs of clustered microcalcifications on mammograms: Observer study results

    SciTech Connect

    Muramatsu, Chisako; Li, Qiang; Schmidt, Robert; Suzuki, Kenji; Shiraishi, Junji; Newstead, Gillian; Doi, Kunio

    2006-09-15

    Presentation of images of lesions similar to that of an unknown lesion might be useful to radiologists in distinguishing between benign and malignant clustered microcalcifications on mammograms. Investigators have been developing computerized schemes to select similar images from large databases. However, whether selected images are really similar in appearance is not examined for most of the schemes. In order to retrieve images that are useful to radiologists, the selected images must be similar from radiologists' diagnostic points of view. Therefore, in this study, the data of radiologists' subjective similarity for pairs of clustered microcalcification images were obtained from a number of observers, and the intra- and inter-observer variations and the intergroup correlations were determined to investigate whether reliable similarity ratings by human observers can be determined. Nineteen images of clustered microcalcifications, each of which was paired with six other images, were selected for the observer study. Thus, subjective similarity ratings for 114 pairs of clustered microcalcifications were determined by each observer. Thirteen breast, ten general, and ten nonradiologists participated in the observer study; some of them completed the study multiple times. Although the intraobserver variations for the individual readings and the interobserver variations for pairs of observers were not small, the interobserver agreements were improved by taking the average of readings by the same observers. When the similarity ratings by a number of observers were averaged among the groups of breast, general, and nonradiologists, the mean differences of the ratings between the groups decreased, and good concordance correlations (0.846, 0.817, and 0.785) between the groups were obtained. The result indicates that reliable similarity ratings can be determined by use of this method, and the average similarity ratings by breast radiologists can be considered meaningful and useful for the development and evaluation of a computerized scheme for selection of similar images.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Critical Illness Outcome Study: An Observational Study on Protocols and Mortality in Intensive Care Units

    PubMed Central

    Ali, Naeem A.; Gutteridge, David; Shahul, Sajid; Checkley, William; Sevransky, Jonathan; Martin, Greg S.

    2014-01-01

    Introduction Many individual Intensive Care Unit (ICU) characteristics have been associated with patient outcomes, including staffing, expertise, continuity and team structure. Separately, many aspects of clinical care in ICUs have been operationalized through the development of complex treatment protocols. The United State Critical Illness and Injury Trials Group-Critical Illness Outcomes Study (USCIITG-CIOS) was designed to determine whether the extent of protocol availability and use in ICUs is associated with hospital survival in a large cohort of United States ICUs. Here, we describe the study protocol and analysis plan approved by the USCIITG-CIOS Steering Committee. Methods USCIITG-CIOS is a prospective, observational, ecological multi-centered “cohort” study of mixed ICUs in the U.S. The data collected include organizational information for the ICU (e.g., protocol availability and utilization, multi-disciplinary staffing assessment) and patient level information (e.g. demographics, acute and chronic medical conditions). The primary outcome is all-cause hospital mortality, with the objective being to determine whether there is an association between protocol number and hospital mortality for ICU patients. USCIITG-CIOS is powered to detect a 3% difference in crude hospital mortality between high and low protocol use ICUs, dichotomized according to protocol number at the median. The analysis will utilize regression modeling to adjust for outcome clustering by ICU, with secondary linear analysis of protocol number and mortality and a variety of a priori planned ancillary studies. There are presently 60 ICUs participating in USCIITG-CIOS to enroll approximately 6,000 study subjects. Conclusions USCIITG-CIOS is a large multicentric study examining the effect of ICU protocol use on patient outcomes. The primary results of this study will inform our understanding of the relationship between protocol availability, use, and patient outcomes in the ICU. Moreover, given the shortage of intensivists worldwide, the results of USCIITG-CIOS can be used to promote more effective ICU and care team design and will impact the delivery of intensive care services beyond individual practitioners. Trial Registration ClinicalTrials.gov Identifier NCT01109719 PMID:25429244

  12. Plate measurement techniques and reduction methods used by the West German satellite observers, and resulting consequences for the observation

    NASA Technical Reports Server (NTRS)

    Deker, H.

    1971-01-01

    The West German tracking stations are equipped with ballistic cameras. Plate measurement and plate reduction must therefore follow photogrammetric methods. Approximately 100 star positions and 200 satellite positions are measured on each plate. The mathematical model for spatial rotation of the bundle of rays is extended by including terms for distortion and internal orientation of the camera as well as by providing terms for refraction which are computed for the measured coordinates of the star positions on the plate. From the measuring accuracy of the plate coordinates it follows that the timing accuracy for the exposures has to be about one millisecond, in order to obtain a homogeneous system.

  13. Sea ice climatology, variations and teleconnections: Observational and modeling studies

    NASA Astrophysics Data System (ADS)

    Liu, Jiping

    Hypotheses, models and observations suggest that sea ice plays an important role in the local, regional and global climate through a variety of processes across a full range of scales. However, our documentation and understanding of the nature of the polar-extrapolar climate teleconnections and their underlying causal and mechanistic links are still rudimentary, and the largest disagreements among model simulations of present and future climate are in the polar regions. In an effort to address these issues, we evaluated the simulated Antarctic sea ice variability and its climate teleconnections in three coupled global climate models (GISS, NCAR and GFDL) as compared to the observations. All the models capture the El Nino-Southern Oscillation (ENSO)-like phenomenon to some degree, although almost all the models miss some observed linkages. The GISS and NCAR models also capture the observed Antarctic Dipole and meridional banding structure through the Pacific. The Antarctic sea ice regions showing the strongest sensitivity to global teleconnections differ among the models and between the models and observations. We then proposed that the changes of the regional mean meridional atmospheric circulation (the regional Ferrel Cell) are one such mechanism leading to the covariability of the ENSO and Antarctic Dipole by modulating the mean meridional heat flux using the observational data. To more accurately represent sea ice simulations and associated feedbacks with the atmosphere and the ocean, the GISS coupled model was used to investigate the sensitivity of sea ice to the following physical parameterizations: (a) two sea ice dynamics (cavitating fluid and viscous-plastic), (b) the specification of oceanic isopyncal mixing coefficients in the Gent and McWillams isopyncal mixing, (c) the Wajsowicz viscosity diffusion, (d) surface albedo, (e) the penetration of solar radiation in sea ice, (f) effects of including a sea ice salinity budget, and (g) the ice-ocean boundary interactions. The atmospheric responses associated with sea ice changes were discussed. Based on these experiments, a series of composite experiments with the aforementioned parameterizations were also investigated. While improvements are seen overall, there are some unrealistic aspects that will require further improvements to the sea ice and ocean components. Finally, the GISS coupled model's ability to represent observed Antarctic sea ice variability and its global teleconnections was re-evaluated in a composite run with the improved sea ice and ocean processes.

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

    PubMed Central

    2010-01-01

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

  15. 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.

  16. Methods and software for cosmic ray scintillation studies

    NASA Technical Reports Server (NTRS)

    Gulinsky, O. V.; Dorman, L. I.; Prilutsky, R. E.

    1985-01-01

    The principal instrument used in cosmic ray scintillation studies is the spectra constructed from intensive observation. This method has its drawbacks in that the statistical characteristics of the process undergo essential reconstruction, i.e., the process becomes nonstationary from the viewpoint of such phenomena as Forbush decrease and during solar flares. The software used to process the above includes the direct Fourier transform and its modifications, autoregressive processes, and instantaneous spectrum methods. Used in various combinations, they prove helpful in handling the time series.

  17. Social Media Methods for Studying Rare Diseases

    PubMed Central

    Stringer, Kathleen A.; Donohue, Janet E.; Yu, Sunkyung; Shaver, Ashley; Caruthers, Regine L.; Zikmund-Fisher, Brian J.; Fifer, Carlen; Goldberg, Caren; Russell, Mark W.

    2014-01-01

    For pediatric rare diseases, the number of patients available to support traditional research methods is often inadequate. However, patients who have similar diseases cluster virtually online via social media. This study aimed to (1) determine whether patients who have the rare diseases Fontan-associated protein losing enteropathy (PLE) and plastic bronchitis (PB) would participate in online research, and (2) explore response patterns to examine social medias role in participation compared with other referral modalities. A novel, internet-based survey querying details of potential pathogenesis, course, and treatment of PLE and PB was created. The study was available online via web and Facebook portals for 1 year. Apart from 2 study-initiated posts on patient-run Facebook pages at the study initiation, all recruitment was driven by study respondents only. Response patterns and referral sources were tracked. A total of 671 respondents with a Fontan palliation completed a valid survey, including 76 who had PLE and 46 who had PB. Responses over time demonstrated periodic, marked increases as new online populations of Fontan patients were reached. Of the responses, 574 (86%) were from the United States and 97 (14%) were international. The leading referral sources were Facebook, internet forums, and traditional websites. Overall, social media outlets referred 84% of all responses, making it the dominant modality for recruiting the largest reported contemporary cohort of Fontan patients and patients who have PLE and PB. The methodology and response patterns from this study can be used to design research applications for other rare diseases. PMID:24733869

  18. Social media methods for studying rare diseases.

    PubMed

    Schumacher, Kurt R; Stringer, Kathleen A; Donohue, Janet E; Yu, Sunkyung; Shaver, Ashley; Caruthers, Regine L; Zikmund-Fisher, Brian J; Fifer, Carlen; Goldberg, Caren; Russell, Mark W

    2014-05-01

    For pediatric rare diseases, the number of patients available to support traditional research methods is often inadequate. However, patients who have similar diseases cluster "virtually" online via social media. This study aimed to (1) determine whether patients who have the rare diseases Fontan-associated protein losing enteropathy (PLE) and plastic bronchitis (PB) would participate in online research, and (2) explore response patterns to examine social media's role in participation compared with other referral modalities. A novel, internet-based survey querying details of potential pathogenesis, course, and treatment of PLE and PB was created. The study was available online via web and Facebook portals for 1 year. Apart from 2 study-initiated posts on patient-run Facebook pages at the study initiation, all recruitment was driven by study respondents only. Response patterns and referral sources were tracked. A total of 671 respondents with a Fontan palliation completed a valid survey, including 76 who had PLE and 46 who had PB. Responses over time demonstrated periodic, marked increases as new online populations of Fontan patients were reached. Of the responses, 574 (86%) were from the United States and 97 (14%) were international. The leading referral sources were Facebook, internet forums, and traditional websites. Overall, social media outlets referred 84% of all responses, making it the dominant modality for recruiting the largest reported contemporary cohort of Fontan patients and patients who have PLE and PB. The methodology and response patterns from this study can be used to design research applications for other rare diseases. PMID:24733869

  19. Mass changes of microparticles in a plasma observed by a phase-resolved resonance method

    SciTech Connect

    Carstensen, Jan; Jung, Hendrik; Greiner, Franko; Piel, Alexander

    2011-03-15

    The influence of a plasma environment on melamine formaldehyde particles is studied. High-precision measurements of the vertical confinement frequency with a phase-resolved resonance method indicate that the particle mass is affected in two ways: the deposition of sputtered material at the particle leads to a mass gain, whereas the outgassing of water causes a mass loss.

  20. 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.

  1. LAT observation of GRBs: Simulations and Sensitivity studies

    SciTech Connect

    Omodei, Nicola; Norris, Jay

    2007-07-12

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

  2. 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.

  3. 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.

  4. 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.

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

    NASA Astrophysics Data System (ADS)

    Bartczak, P.; Santana-Ros, T.; Marciniak, A.; Michałowski, T.; Prętka-Ziomek, H.

    2014-04-01

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

  6. 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...

  7. Studying Rain Rate from Space and Ground Observations

    NASA Astrophysics Data System (ADS)

    Amitai, Eyal

    2007-07-01

    The distribution of rain rates (R) is of great interest in many fields. For example, hydrological applications such as flood forecasting depend on an accurate representation of the excess rainfalldriven by Rthat does not infiltrate the soil. It is also of great concern to radio wave propagationthe theme of this symposium. Probability distribution functions (pdf) of R can now be obtained from spaceborne radar observations. Effort to evaluate these pdfs using ground observations is presented. The evaluation of instantaneous rainfall products and rain rate estimates from space is quite a challenge. Scatter plots of pixel-by-pixel comparisons of space-based R estimates with ground-based radar R estimates are extremely noisy because of sample volume discrepancies, timing and navigation mismatches, and uncertainties in the observed-radar reflectivity rain-rate Ze-R relations. Furthermore, comparisons of rainfall over daily, weekly or even monthly time scales suffer from the temporal sampling errors of the satellite where the revisit time is on the order of hours or days (e.g., the Tropical Rainfall Measuring Mission [TRMM] satellite, the future Global Precipitation Measurement [GPM] mission satellite). Consequently, an alternative approach of comparing space-based radar pdfs with pdfs derived from co-located ground-based radar observations is attractive for evaluating satellite-based precipitation products, such as those from TRMM precipitation radar (PR). We will present comparisons of R estimates from the TRMM PR and co-located data from gauge-adjusted ground-based radar (WSR-88D) estimates obtained during nine years of observations. These results provide an overview of how well the satellite retrieved estimatesbased on the new NASA TRMM radar rainfall productscompare to the ground-based estimates. These comparisons are part of a new framework for global verification of space-borne radar estimates of precipitation based on comparing pdfs of R. The framework demonstrates how a hydrologic approach that uses statistical properties of precipitation to estimate the uncertainties can be combined with a meteorological approach that uses physical properties of rainfall. The presentation provides insights into the uncertainties in space-based and ground-based radar estimates of rain rate distributions, and a discussion of opportunities and challenges to determine and reduce these uncertainties. This presentation combines results which are summarized in [1], [2], and [3]. Examples of comparison are provided in the following figures.

  8. Methods applicable to membrane nanodomain studies?

    PubMed

    Ashrafzadeh, Parham; Parmryd, Ingela

    2015-01-01

    Membrane nanodomains are dynamic liquid entities surrounded by another type of dynamic liquid. Diffusion can take place inside, around and in and out of the domains, and membrane components therefore continuously shift between domains and their surroundings. In the plasma membrane, there is the further complexity of links between membrane lipids and proteins both to the extracellular matrix and to intracellular proteins such as actin filaments. In addition, new membrane components are continuously delivered and old ones removed. On top of this, cells move. Taking all of this into account imposes great methodological challenges, and in the present chapter we discuss some methods that are currently used for membrane nanodomain studies, what information they can provide and their weaknesses. PMID:25658344

  9. 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

  10. Osteoporosis Therapies: Evidence from Health-Care Databases and Observational Population Studies

    PubMed Central

    2010-01-01

    Osteoporosis is a well-recognized disease with severe consequences if left untreated. Randomized controlled trials are the most rigorous method for determining the efficacy and safety of therapies. Nevertheless, randomized controlled trials underrepresent the real-world patient population and are costly in both time and money. Modern technology has enabled researchers to use information gathered from large health-care or medical-claims databases to assess the practical utilization of available therapies in appropriate patients. Observational database studies lack randomization but, if carefully designed and successfully completed, can provide valuable information that complements results obtained from randomized controlled trials and extends our knowledge to real-world clinical patients. Randomized controlled trials comparing fracture outcomes among osteoporosis therapies are difficult to perform. In this regard, large observational database studies could be useful in identifying clinically important differences among therapeutic options. Database studies can also provide important information with regard to osteoporosis prevalence, health economics, and compliance and persistence with treatment. This article describes the strengths and limitations of both randomized controlled trials and observational database studies, discusses considerations for observational study design, and reviews a wealth of information generated by database studies in the field of osteoporosis. PMID:20725827

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    NASA Technical Reports Server (NTRS)

    Somerville, Richard C. J.

    1997-01-01

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

  13. 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.; Besanon, 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-Prez, 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.; Dliot, 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.; Faur, 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.; Garca-Gonzlez, 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.; Grnendahl, S.; Grnewald, 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.; Jaffr, 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.; Magaa-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martnez-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.; Ptroff, 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.; Snchez-Hernndez, 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.; Sldner-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.

  14. Observations on studies useful to asbestos operations and management activities

    SciTech Connect

    Wilmoth, R.C.; Powers, T.J.; Millette, J.R.

    1991-01-01

    Asbestos-containing materials found in buildings may release asbestos fibers into the air. Some of these fibers will eventually settle and attach to room surfaces (walls, furnishings, equipment, floors, and carpet) as part of normal dust. Activities like dusting, sweeping and vacuuming are likely to re-entrain the dust causing exposure to airborne asbestos. The paper discusses data that are largely observational in nature, but are illustrative of general trends of interest to those individuals dealing with the day-to-day problems of asbestos in buildings.

  15. 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.

  16. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  18. 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

  19. 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.

  20. A Observational Study of the Internal Structure of Airmass Thunderstorms

    NASA Astrophysics Data System (ADS)

    Kingsmill, David Edmund

    The internal structure of airmass thunderstorms is examined with Doppler and dual-polarization radar, photographic and rawinsonde data from the 1986 MIST project. A kinematic, dynamic and thermodynamic analysis of one well documented case shows a life cycle which closely resembles the Byers and Braham model for airmass storms. Other less detailed cases, examined to supplement this analysis, largely confirm these findings. However, several phenomena never documented for this storm-type are discussed. One of these is a midlevel inflow, which in one case caused a visible constriction in a storm cloud. This inflow appears to arise from the mass compensation required when a strong updraft driven by buoyancy from glaciation forms above a weaker updraft loaded down by the precipitation core. A downdraft at midlevels with an associated "weak-echo" trench is also observed. Its origin appears related to a shear induced wake entrainment process. In addition, microburst intensity surface outflows are observed. The downdrafts responsible for these events appear to be restricted to low levels and to be separate from the midlevel downdraft. One case shows this type of downdraft to be initiated by precipitation loading and intensified by negative thermal buoyancy. In light of these new features, the Byers and Braham model of the cumulus, mature and dissipating stages is reexamined.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  2. 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.

  3. 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.

  4. A microfluidic method to study demulsification kinetics.

    PubMed

    Krebs, Thomas; Schroen, Karin; Boom, Remko

    2012-03-21

    We present the results of experiments studying droplet coalescence in a dense layer of emulsion droplets using microfluidic circuits. The microfluidic structure allows direct observation of collisions and coalescence events between oil droplets dispersed in water. The coalescence rate of a flowing hexadecane-in-water emulsion was measured as a function of the droplet velocity and droplet concentration from image sequences measured with a high-speed camera. A trajectory analysis of colliding droplet pairs allows evaluation of the film drainage profile and coalescence time t(c.) The coalescence times obtained for thousands of droplet pairs enable us to calculate coalescence time distributions for each set of experimental parameters, which are the mean droplet approach velocity (v(0)), the mean dispersed phase fraction (φ) and the mean hydraulic diameter of a droplet pair (d(p)). The expected value E(t(c)) of the coalescence time distributions scales as E(t(c)) is proportional to (v(0))(-0.105±0.043)(d(p))(0.562±0.287), but is independent of φ. We discuss the potential of the procedure for the prediction of emulsion stability in industrial applications. PMID:22215134

  5. 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.

  6. 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.

  7. 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.

  8. Feature selection methods in QSAR studies.

    PubMed

    Goodarzi, Mohammad; Dejaegher, Bieke; Vander Heyden, Yvan

    2012-01-01

    A quantitative structure-activity relationship (QSAR) relates quantitative chemical structure attributes (molecular descriptors) to a biological activity. QSAR studies have now become attractive in drug discovery and development because their application can save substantial time and human resources. Several parameters are important in the prediction ability of a QSAR model. On the one hand, different statistical methods may be applied to check the linear or nonlinear behavior of a data set. On the other hand, feature selection techniques are applied to decrease the model complexity, to decrease the overfitting/overtraining risk, and to select the most important descriptors from the often more than 1000 calculated. The selected descriptors are then linked to a biological activity of the corresponding compound by means of a mathematical model. Different modeling techniques can be applied, some of which explicitly require a feature selection. A QSAR model can be useful in the design of new compounds with improved potency in the class under study. Only molecules with a predicted interesting activity will be synthesized. In the feature selection problem, a learning algorithm is faced with the problem of selecting a relevant subset of features upon which to focus attention, while ignoring the rest. Up to now, many feature selection techniques, such as genetic algorithms, forward selection, backward elimination, stepwise regression, and simulated annealing have been used extensively. Swarm intelligence optimizations, such as ant colony optimization and partial swarm optimization, which are feature selection techniques usually simulated based on animal and insect life behavior to find the shortest path between a food source and their nests, recently are also involved in QSAR studies. This review paper provides an overview of different feature selection techniques applied in QSAR modeling. PMID:22816254

  9. Observational studies on evaluating the safety and adverse effects of traditional chinese medicine.

    TOXLINE Toxicology Bibliographic Information

    Lai JN; Tang JL; Wang JD

    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.

  10. 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

  11. Observational studies on evaluating the safety and adverse effects of traditional chinese medicine.

    PubMed

    Lai, Jung-Nein; 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

  12. Study of the solar corona using radio and space observations

    NASA Technical Reports Server (NTRS)

    Dulk, G. A.

    1979-01-01

    Optical, radio and X-ray evidence of violent mass motions in the corona has existed for some years but only recently have the form, nature, frequency and implication of the transients become obvious. The observed properties of coronal transients concentrating on the white-light and radio manifestations. The possible mechanisims involved in the radio bursts are discussed. The estimates of various forms of energy are reviewed. It appears that the magnetic energy transported from the Sun by the transient exceeds that of any other form, and that magnetic forces dominate in the dynamics of the motions. The conversion of magnetic energy into mechanical energy, by expansion of the fields, provides a possible driving force for the coronal and interplanetary shock waves.

  13. Observational study of food safety practices in retail deli departments.

    PubMed

    Lubran, M B; Pouillot, R; Bohm, S; Calvey, E M; Meng, J; Dennis, S

    2010-10-01

    In order to improve the safety of refrigerated ready-to-eat food products prepared at retail deli departments, a better understanding of current practices in these establishments is needed. Food employees in deli departments at six chain and three independent retail establishments in Maryland and Virginia were observed, using notational analysis, as they prepared deli products for sale. The frequency of contact with objects and deli products before sale, hand washing and glove changing during preparation, and equipment, utensil, and surface cleaning and sanitizing was determined. Compliance with the U.S. Food and Drug Administration's 2005 model Food Code recommendations, which must be adopted by the individual state and local jurisdictions that are responsible for directly regulating retail establishments, was also assessed. Observations indicated there were a large number of actions for which hand washing was recommended at independent and chain stores (273 recommended of 1,098 total actions and 439 recommended of 3,073 total actions, respectively). Moreover, 67% (295 of 439) of the actions for which hand washing was recommended at the chain stores and 86% (235 of 273) of those at the independent stores resulted from employees touching non-food contact surfaces prior to handling ready-to-eat food. Compliance with hand washing recommendations was generally low and varied depending on store type with independent stores exhibiting lower compliance than chain stores (5 instances of compliance for 273 recommended actions and 73 instances of compliance for 439 recommended actions, respectively). Potential risk mitigation measures that may reduce the frequency of hand washing actions needed during ready-to-eat food preparation in retail deli departments are discussed. More research is needed to determine the impact of such measures on food safety. PMID:21067673

  14. 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

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

    NASA Astrophysics Data System (ADS)

    Prchniewicz, Dominik; Szpunar, Ryszard

    2015-04-01

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

  17. Observations of a potential Mars analog at the microscale using rover-inspired methods: A 10-sol observation of Fort Rock tuff ring

    NASA Astrophysics Data System (ADS)

    Yingst, R. A.; Schmidt, M. E.; Lentz, R. C. F.

    2009-06-01

    The terrestrial geologist's hand lens is a fundamental tool for identifying and correlating rocks and minerals. We used rover-inspired methods of remote hand lens-scale data acquisition to conduct reconnaissance of a well-characterized Martian analog field site. The objective was to determine if the current methodologies associated with the use of remote hand lens-scale imagers maximizes science return. Field geologists provided with hand lens-scale images of targets in geologic context could correctly identify many important characteristics of those targets. However, they could not fully confirm or rule out any formation hypothesis using the data provided solely through rover-driven observational strategies. This was due to (1) a lack of “intermediate-scale,” or millimeter- to centimeter-scale images providing important contextual information for the targets studied and (2) the limited number of hand lens-scale images that were taken using rover-driven methodology. We conclude that the benefits of the hand lens as an effective triage tool and discriminator of microtexture are limited using current rover-driven methodology because the hand lens-type imager is not deployed frequently, and resulting data cannot be used to fully support geochemical observations. We recommend pursuing ways to increase the number of images that can reasonably be acquired at the hand lens scale. In order for hand lens-scale imaging to be fully effective, textural characteristics diagnostic of the nature of a geologic site need to be identifiable at a number of different resolutions; rover microscale observational strategies must include more contextual imaging.

  18. Study on short term prediction using observed water quality from 8-day intervals in Nakdong river

    NASA Astrophysics Data System (ADS)

    Kim, M.; Shon, T.; Joo, J.; Kim, J.; Shin, H.

    2012-12-01

    There are lots of accidents on water quality, like green algal blooms, occurring in Nakdong river which is one of the largest river in Korea. This is because of climate change around the world. It is essential to develop scientific and quantitative assessment methods. In this study, artificial neural network based on back propagation algorithm, which is simple and flexible method, was used for forecasting the water quality on the purpose of water resources management. Especially, as used observed water quality data from 8-day intervals in Nakdong river, it makes to increase the accuracy of water quality forecast over short term. This was established for predicting the water quality factors 1, 3, and 7 days ahead. The best model, as evaluated by its performance functions with RMSE and R2, was selected and applied to established models of BOD, DO, COD, and Chl-a using artificial neural network. The results showed that the models were suitable for 1 and 3 days forecasts in particular. This method is strong and convenient to predict water quality factors over the short term easily based on observed data. It is possible to overcome and manage problems related to the water resources. In the future, this will be a powerful method because it is basically based on observed water quality data.

  19. 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

  20. 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 2π in azimuth and has 25 AU < r < 50 AU is detectable at 1200σ to 4000σ. The lower limits of the radii of 5σ-detectable LMG clumps are between 1.6 AU and 5.3 AU, depending on the models.

  1. 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 200709. Main outcome measures For each papers 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 326%) but only 3.5% (37%) 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 studys findings. PMID:23249670

  2. Cost-of-illness studies : a review of current methods.

    PubMed

    Akobundu, Ebere; Ju, Jing; Blatt, Lisa; Mullins, C Daniel

    2006-01-01

    The number of cost-of-illness (COI) studies has expanded considerably over time. One outcome of this growth is that the reported COI estimates are inconsistent across studies, thereby raising concerns over the validity of the estimates and methods. Several factors have been identified in the literature as reasons for the observed variation in COI estimates. To date, the variation in the methods used to calculate costs has not been examined in great detail even though the variations in methods are a major driver of variation in COI estimates. The objective of this review was to document the variation in the methodologies employed in COI studies and to highlight the benefits and limitations of these methods. The review of COI studies was implemented following a four-step procedure: (i) a structured literature search of MEDLINE, JSTOR and EconLit; (ii) a review of abstracts using pre-defined inclusion and exclusion criteria; (iii) a full-text review using pre-defined inclusion and exclusion criteria; and (iv) classification of articles according to the methods used to calculate costs. This review identified four COI estimation methods (Sum_All Medical, Sum_Diagnosis Specific, Matched Control and Regression) that were used in categorising articles. Also, six components of direct medical costs and five components of indirect/non-medical costs were identified and used in categorising articles.365 full-length articles were reflected in the current review following the structured literature search. The top five cost components were emergency room/inpatient hospital costs, outpatient physician costs, drug costs, productivity losses and laboratory costs. The dominant method, Sum_Diagnosis Specific, was a total costing approach that restricted the summation of medical expenditures to those related to a diagnosis of the disease of interest. There was considerable variation in the methods used within disease subcategories. In several disease subcategories (e.g. asthma, dementia, diabetes mellitus), all four estimation methods were represented, and in other cases (e.g. HIV/AIDS, obesity, stroke, urinary incontinence, schizophrenia), three of the four estimation methods were represented. There was also evidence to suggest that the strengths and weaknesses of each method were considered when applying a method to a specific illness. Comparisons and assessments of COI estimates should consider the method used to estimate costs both as an important source of variation in the reported COI estimates and as a marker of the reliability of the COI estimate. PMID:16942122

  3. Ergonomic exposure assessment: an application of the PATH systematic observation method to retail workers. Postures, Activities, Tools and Handling.

    PubMed

    Pan, C S; Gardner, L I; Landsittel, D P; Hendricks, S A; Chiou, S S; Punnett, L

    1999-01-01

    This study examined biomechanical stressor variables (physical work exposures) in relation to job title, gender, and back-belt status in 134 retail store workers. The principal concerns were to quantitatively describe physical work exposures and to determine the degrees to which these quantitative variables correlated with job title and with the use of back belts. An additional objective was to assess the inter-rater reliability of the observation method. The systematic observation method employed was based on a modification of the PATH (Postures, Activities, Tools, and Handling) measurement method. Chi-square analysis indicated that the frequencies of bent or twisted postures followed the pattern of unloaders > stockers > department managers. For weight handled per lift, lower, or carry, the pattern was unloaders > department managers > stockers. The mean lifting frequencies per hour were 35.9 for department managers, 48.8 for stockers, and 137.4 for unloaders. Back-belt-wearing percentages were higher for unloaders (63%) compared with stockers (48%) and department managers (25%). Back-belt-wearing workers had higher levels of biomechanical stressor variables, including arm position, twisting, weight handled, and number of lifts per hour. Kappa statistics ranged from 0.5 to 0.63, a level of adequate or good reliability beyond chance. The method employed in this study is applicable in studies that require only fairly crude distinctions among biomechanical stressor variables. Nevertheless, this level of distinction may be sufficient when implementing intervention studies and control strategies for many material-handling-intensive jobs. PMID:10330506

  4. 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.

  5. 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.

  6. On methods for studying stochastic disease dynamics.

    PubMed

    Keeling, M J; Ross, J V

    2008-02-01

    Models that deal with the individual level of populations have shown the importance of stochasticity in ecology, epidemiology and evolution. An increasingly common approach to studying these models is through stochastic (event-driven) simulation. One striking disadvantage of this approach is the need for a large number of replicates to determine the range of expected behaviour. Here, for a class of stochastic models called Markov processes, we present results that overcome this difficulty and provide valuable insights, but which have been largely ignored by applied researchers. For these models, the so-called Kolmogorov forward equation (also called the ensemble or master equation) allows one to simultaneously consider the probability of each possible state occurring. Irrespective of the complexities and nonlinearities of population dynamics, this equation is linear and has a natural matrix formulation that provides many analytical insights into the behaviour of stochastic populations and allows rapid evaluation of process dynamics. Here, using epidemiological models as a template, these ensemble equations are explored and results are compared with traditional stochastic simulations. In addition, we describe further advantages of the matrix formulation of dynamics, providing simple exact methods for evaluating expected eradication (extinction) times of diseases, for comparing expected total costs of possible control programmes and for estimation of disease parameters. PMID:17638650

  7. 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.

  8. 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.

  9. The Foreigner Talk of a Family Physician: An Observational Study.

    ERIC Educational Resources Information Center

    Nelson, Dana Kristine

    A study analyzed the characteristics of one male physician's foreigner talk over the telephone with non-native speakers (NNSs) of English and compared it to that of native speakers (NSs). The conversations all related to requests that patients come into the office for a periodic, preventative physical exam. Data came from tape recordings of the…

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

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

    ERIC Educational Resources Information Center

    Chen, Jianshen; Kaplan, David

    2015-01-01

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

  12. 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

  13. 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…

  14. 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…

  15. 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

  16. ORD BEST PRACTICES FOR OBSERVATIONAL HUMAN EXPOSURE MEASUREMENT STUDIES

    EPA Science Inventory

    This abstract describes a presentation for the 2007 Society of Toxicology Annual Meeting in Charlotte, NC on March 27, 2007. It will be included in a special Issues Session titled "Scientific and Ethical Considerations in Human Exposure Studies." The presentation desc...

  17. 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...

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

    ERIC Educational Resources Information Center

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

    1998-01-01

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

  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. 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

  1. 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.

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

    SciTech Connect

    Carter, Emily A

    2013-02-02

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

  3. Revisiting the determination of solar oblateness from space observations using an optimization method

    NASA Astrophysics Data System (ADS)

    Hauchecorne, A.; Meftah, M.; Irbah, A.

    2014-12-01

    The Sun is an almost perfect sphere. Its oblateness is about 10-5 of its radius. Its knowledge can provide strong constraints on solar interior models. The shape of the Sun is depending on the gravitational potential produced by the internal distribution of mass and on centrifugal forces due to the solar rotation. However, due to its very small value, the solar oblateness is very difficult to measure and its determination requires a very good understanding of any possible instrumental effect. Optical effects may distort the image on the CCD and it is not possible to detect the very small difference between the polar and the equatorial radius in a single image. In order to overcome this problem, a distortion mode is implemented. It consists in rotating the satellite by equal angle steps. Once the images have been corrected to all known effects, it is possible to compute the mean solar radius versus the angle on the solar disk averaged over all satellite positions and to fit the results by a sine function to determine the oblateness. When analysing the solar radius versus angle data, we observe an anticorrelation between the limb brightness and the radius determined from the inflection point. The apparent radius is smaller if an active region is near the limb. The bright active regions are confined to low latitudes and never occur at the poles, which may cause an artefact in the determination of the solar oblateness leading to a negative bias. We developed a new method based on a correction of the solar radius for a given solar angle according to the brightness of the limb at the inflection point and its derivative with radius. This method has been applied to several sequences of SODISM and HMI observations. It provides larger oblateness values than the one based on inflection point, ranging between 8.5 and 9.0 mas for both instruments, in good agreement with the theoretical predictions considering the rotation of the sun. It indicates that the classical method of the inflection point needs to be revisited to take into account the variability of the limb brightness for the determination the solar oblateness.

  4. Study of the low latitude ionospheric turbulence observed by DEMETER

    NASA Astrophysics Data System (ADS)

    Li, F.; Lefeuvre, F.; Parrot, M.

    Following previous works from Molchanov et al 2002a 2002b 2004a 2004b and Hobara et al 2005 data bases dedicated to the systematic analysis of the power and spectral indices of the electric field have been elaborated Two data bases are considered one for the survey mode and the other for the burst mode For the survey mode estimations of the turbulence parameters are performed from the 8 first Fourier components of the averaged power spectra 0-150 Hz frequency band A single slope power law model f - alpha is assumed A quality factor allows to test that hypothesis For the burst mode the power spectra are derived from the waveforms One and two slope models are systematically tested Results are presented and the possibility to use these data bases for correlation with seismic activity is discussed Y Hobara F Lefeuvre M Parrot and O A Molchanov Low-latitude ionospheric turbulence observed by Aureol-3 satellite Annales Geophysicae 23 1259--1270 2005 Molchanov O A Hayakawa M Afonin V V Akentieva O A and Mareev E A Possible influence of seismicity by gravity waves on ionospheric equatorial anomaly from data of IK-24 satellite 1 Search for idea of seismo-ionosphere coupling Seismo Electromagnetics Lithosphere-Atmosphere-Ionosphere Coupling edited by Hayakawa M and Molchanov O A TERRAPUB Tokyo 275--285 2002a Molchanov O A Hayakawa M Afonin V V Akentieva O A Mareev E A and Trakhtengerts V Yu Possible influence of seismicity by gravity waves on ionospheric

  5. 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.

  6. 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.

  7. Antidepressant use and risk of coronary heart disease: meta-analysis of observational studies

    PubMed Central

    Oh, Seung-Won; Kim, Joonseok; Myung, Seung-Kwon; Hwang, Seung-Sik; Yoon, Dae-Hyun

    2014-01-01

    Aims Our goal was to evaluate the association between antidepressant use and the risk of coronary heart disease (CHD) among subjects with no history of coronary heart disease. Methods A search of Medline, EMBASE, PsycINFO and the Cochrane Library was performed in January 2013. Two authors independently reviewed and selected eligible observational studies, based on predetermined selection criteria. Pooled relative risks (RRs) with confidence intervals (CIs) were calculated using random-effects or fixed-effects models. Results Sixteen observational studies (seven casecontrol studies and nine cohort studies) were included in the final analysis. There was no association between selective serotonin reuptake inhibitor use and the risk of CHD overall [odds ratio (OR), 0.93; 95% CI, 0.651.33] or in subgroup meta-analysis of casecontrol studies (OR, 0.91; 95% CI, 0.601.37) and cohort studies (RR, 0.96; 95% CI, 0.591.55). The use of tricyclic antidepressant was associated with an increased risk of CHD overall (OR, 1.51; 95% CI, 1.072.12), but it was observed only in casecontrol studies (OR, 1.56; 95% CI, 1.241.96) and low-quality studies (OR, 1.49; 95% CI, 1.201.85) in the subgroup meta-analyses. Conclusions This meta-analysis of observational studies in subjects with no history of CHD suggests that neither selective serotonin reuptake inhibitor nor tricyclic antidepressant use is associated with an increased risk of CHD. PMID:24646010

  8. Complicated intra-abdominal infections in a worldwide context: an observational prospective study (CIAOW Study)

    PubMed Central

    2013-01-01

    Despite advances in diagnosis, surgery, and antimicrobial therapy, mortality rates associated with complicated intra-abdominal infections remain exceedingly high. The World Society of Emergency Surgery (WSES) has designed the CIAOW study in order to describe the clinical, microbiological, and management-related profiles of both community- and healthcare-acquired complicated intra-abdominal infections in a worldwide context. The CIAOW study (Complicated Intra-Abdominal infection Observational Worldwide Study) is a multicenter observational study currently underway in 57 medical institutions worldwide. The study includes patients undergoing surgery or interventional drainage to address complicated intra-abdominal infections. This preliminary report includes all data from almost the first two months of the six-month study period. Patients who met inclusion criteria with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study. 702 patients with a mean age of 49.2 years (range 18–98) were enrolled in the study. 272 patients (38.7%) were women and 430 (62.3%) were men. Among these patients, 615 (87.6%) were affected by community-acquired IAIs while the remaining 87 (12.4%) suffered from healthcare-associated infections. Generalized peritonitis was observed in 304 patients (43.3%), whereas localized peritonitis or abscesses was registered in 398 (57.7%) patients. The overall mortality rate was 10.1% (71/702). The final results of the CIAOW Study will be published following the conclusion of the study period in March 2013. PMID:23286785

  9. Deriving MLT Tides Based on Observations from a Slowly-Precessing Satellite: A Comparison of Methods

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Forbe, J.; Palo, S.; Russell, J.; Mertens, C.; Mlynczak, M.

    The SABER instrument on TIMED provides unprecedented geographical coverage for the determination and study of atmospheric tides However the slow local time prcession rate of TIMED can cause longer-term temperature variations to alias into the tidal signals Two new methods of analyzing satellite data for tides has been developed to circumvent this difficulty but at the expense of temporal resolution of the tidal fields i e either 60-day mean or 120-day mean tidal structures are obtained In this work we compare the advantages and disadvantages of these two methods in the context of deriving tides from SABER temperature data This work also includes a brief scientific interpretation of the results

  10. Methods for characterizing fine particulate matter using ground observations and remotely sensed data: potential use for environmental public health surveillance.

    PubMed

    Al-Hamdan, Mohammad Z; Crosson, William L; Limaye, Ashutosh S; Rickman, Douglas L; Quattrochi, Dale A; Estes, Maurice G; Qualters, Judith R; Sinclair, Amber H; Tolsma, Dennis D; Adeniyi, Kafayat A; Niskar, Amanda Sue

    2009-07-01

    This study describes and demonstrates different techniques for surface fitting daily environmental hazards data of particulate matter with aerodynamic diameter less than or equal to 2.5 microm (PM2.5) for the purpose of integrating respiratory health and environmental data for the Centers for Disease Control and Prevention (CDC) pilot study of Health and Environment Linked for Information Exchange (HELIX)-Atlanta. It presents a methodology for estimating daily spatial surfaces of ground-level PM2.5 concentrations using the B-Spline and inverse distance weighting (IDW) surface-fitting techniques, leveraging National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectrometer (MODIS) data to complement U.S. Environmental Protection Agency (EPA) ground observation data. The study used measurements of ambient PM2.5 from the EPA database for the year 2003 as well as PM2.5 estimates derived from NASA's satellite data. Hazard data have been processed to derive the surrogate PM2.5 exposure estimates. This paper shows that merging MODIS remote sensing data with surface observations of PM,2. not only provides a more complete daily representation of PM,2. than either dataset alone would allow, but it also reduces the errors in the PM2.5-estimated surfaces. The results of this study also show that although the IDW technique can introduce some numerical artifacts that could be due to its interpolating nature, which assumes that the maxima and minima can occur only at the observation points, the daily IDW PM2.5 surfaces had smaller errors in general, with respect to observations, than those of the B-Spline surfaces. Finally, the methods discussed in this paper establish a foundation for environmental public health linkage and association studies for which determining the concentrations of an environmental hazard such as PM2.5 with high accuracy is critical. PMID:19645271

  11. 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...

  12. 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…

  13. 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.

  14. 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

  15. An observational study of stratocumulus entrainment and thermodynamics

    NASA Technical Reports Server (NTRS)

    Kawa, S. R.; Pearson, R., Jr.

    1989-01-01

    The stratocumulus (SC) entrainment and thermodynamics are studied using data from the Dynamics and Chemistry of Marine Stratocumulus (DYCOMS) experiment. The rate of entrainment of air from the free troposphere into the cloud-topped PBL is estimated using a technique based on the measurement of ozone flux and mean distribution. The average measured value of entrainment rate was found to be 3.0 mm/s with a range of 1.0 to 5.0 mm/s for cloudy cases. Thermodynamic budgets are constructed for eight DYCOMS cases. It was found that the divergence of the solar radiative flux is an important component of the boundary-layer energetics during midday, the factor which must be accounted for in mixed-layer models. The net longwave radiative flux profiles show good agreement with theoretical models, but an unambiguous partitioning of the flux divergence between inversion and mixed layers could not be established.

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

    NASA Astrophysics Data System (ADS)

    Pignone, Flavio; Rebora, Nicola; Silvestro, Francesco

    2015-04-01

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

  17. Sex differences in selection of pacemakers: retrospective observational study

    PubMed Central

    Schppel, Reinhart; Bchele, Gisela; Batz, Lothar; Koenig, Wolfgang

    1998-01-01

    Objective: To evaluate the effect of patients sex on selection of pacemakers. Design: Retrospective univariate and multivariate analysis of a large database. Setting: German central pacemaker register. Subjects: Records collected at the register for 1992 and 1993 (n=31?913), covering 64% of all implantations in Germany. Main outcome measure: Probability of receiving a single chamber, dual chamber, or rate responsive pacemaker in relation to sex. Results: Univariate analysis showed that women were more likely to receive single chamber pacemakers and less likely to receive dual chamber or rate responsive systems than men. After demographic and clinical variables were controlled for, women were still more likely to receive a single chamber system (atrial pacing: odds ratio 0.89, 95% confidence interval 0.74 to 1.07; ventricular pacing: 0.85, 0.80 to 0.92) and less likely to receive a dual chamber (1.20, 1.12 to 1.30) or a rate responsive system (1.26, 1.17 to 1.37) than men. Conclusions: The data suggest sex differences in the selection of a pacemaker system which cannot be explained by the underlying cardiac disorder. Further research is needed to evaluate why guidelines for implanting pacemakers are not better adhered to. Key messages Use of pacemakers varies despite guidelines, and the reasons for this are unclear In this study women were more likely to receive single chamber pacemakers and less likely to receive dual chamber and rate responsive pacemakers than men Demographic and clinical variables cannot fully explain these differences Prospective studies are needed to evaluate the effect of sex and other non-medical variables on the selection of pacemakers PMID:9582133

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

    PubMed

    Olsson, Carl-Johan; Lundstrm, 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

  19. 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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  1. 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

  2. Detection Method of Lightning and TLEs by JEM-GLIMS Nadir Observation

    NASA Astrophysics Data System (ADS)

    Adachi, T.; Sato, M.; Ushio, T.; Yamazaki, A.; Suzuki, M.; Masayuki, K.; Takahashi, Y.; Inan, U.; Linscott, I.; Hobara, Y.

    2013-12-01

    A scientific payload named JEM-GLIMS aboard the International Space Station (ISS) is aimed at observing lightning and Transient Luminous Events (TLEs) globally. Keeping its field-of-view toward the nadir direction, GLIMS clarifies the horizontal structures of lightning and TLEs, which is a crucial issue to understand the electrodynamic coupling between the troposphere and ionosphere. A difficult point, however, is that careful analyses are necessary to separate the emissions of lightning and TLEs which spatially overlap along the line-of-sights in the case of nadir observation. In this study, we analyze the multi-wavelength optical data obtained by GLIMS to identify lightning and TLEs. The main data analyzed are those of imager (LSI) and spectrophotometer (PH). LSI consists of two cameras equipped with a broadband red filter and a narrowband 762-nm filter, respectively, and obtains imagery at a spatial resolution of 400 m/pixel on the ground surface. PH detects time-resolved emission intensity at a sampling rate of 20 kHz by six photometer channels measuring at 150-280, 337, 762, 600-900, 316 and 392 nm, respectively. During a period between November 2012 and June 2013, GLIMS observed 815 lightning and/or TLE events, and in 494 of them, both LSI and PH data showed clear signals above the noise level. As the first step, we carried out case study using an event observed at 09:50:47UT on Jan 29 2013 which did not cause strong saturation on the LSI and PH data. The estimated peak irradiance was 1.38x10^(-3) W/m^(2) at 600-900 nm, which is equivalent to the top 10 % bright lightning events observed by FORTE satellite in the past. This finding suggests that GLIMS selectively observes the most optically-powerful events. The peak irradiance was estimated also for the other PH channels. At all visible channels other than a far ultra violet (FUV) channel, the peak irradiance was estimated to be in good agreement with the atmospheric transmittance curve calculated between 10 km and ISS altitude. We therefore primarily attribute the visible emissions of this event to lightning discharge occurring in the troposphere. Interestingly, GLIMS also detected the FUV emission which is significantly stronger than that expected for tropospheric lightning. This finding suggests that TLE also occurred at higher altitudes where the FUV emission is not affected by atmospheric attenuation. As such, it is clear that GLIMS is able to discriminate optical emissions of lightning and TLEs occurring in the nadir direction. In the conference, we will examine the identification technique in details and, by applying it to all the events, will discuss the validity and limitation.

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

    PubMed

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

    2013-07-01

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

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

    PubMed

    Giacoppo, Sabrina; Galuppo, Maria; Calabr, Rocco Salvatore; D'Aleo, Giangaetano; Marra, Angela; Sessa, Edoardo; Bua, Daniel Giuseppe; Potort, 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

  5. Risk factors for suicide behaviors in the observational schizophrenia outpatient health outcomes (SOHO) study

    PubMed Central

    2012-01-01

    Background To identify risk factors for suicide using data from a large, 3-year, multinational follow-up study of schizophrenia (SOHO study). Methods Baseline characteristics of 8,871 adult patients with schizophrenia were included in a logistic regression post-hoc analysis comparing patients who attempted and/or committed suicide during the study with those who did not. Results 384 (4.3%) patients attempted or committed suicide. Completed suicides were 27 (0.3%). The significant risk factors for suicide behaviors were previous suicidality, depressive symptoms, prolactin-related adverse events, male gender and history of hospitalization for schizophrenia. Conclusions In view of the observational design of the study and the post-hoc nature of the analysis, the identified risk factors should be confirmed by ad-hoc specifically designed studies. PMID:22812421

  6. 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.

  7. 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.

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

    PubMed Central

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

    2013-01-01

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

  9. Effects of sill (traps) on wave fields on observations by the multiple reflection method

    SciTech Connect

    Urupov, A.K.; Karasik, V.M.; Popov, V.V.

    1984-03-01

    The Tunguska syncline is considered as one of the most promising oil and gas regions. However, it is difficult to resolve structural problems there because of the very complicated seismogeological conditions, especially in the upper part of the section. At depths down to 1 km there are sills of various shapes which adversely affect the passage of useful waves and produce multiple reflections. Less is known about the effects of local traps of restricted extent in the upper part of the section on the kinematic and dynamic parameters of the reflections from the underlying boundaries as recorded by the multiple reflection method (MRM). However, results from theoretical, model, and experimental studies indicate that local inhomogeneities in the overlying beds play an important part in producing the reflected-wave fields. The Vanavar area is studied by using mathematical simulation to examine the distorting action of local traps on the reflected-wave kinematic parameters. 6 references, 2 figures.

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

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  11. Problems in Constructing an Observation Instrument for Instructional Cues: A Pilot Study. Twente Educational Memorandum No. 20.

    ERIC Educational Resources Information Center

    de Bruyn, I.; Tomic, W.

    This study dealt with the construction of an observation instrument for instructional cues. Cues are defined as a complex of instructions, methods, and conditions by which students both learn the material and learn to apply the material. As part of the "Classroom Environment Study: Teaching for Learning," the pilot study began a review of the…

  12. 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

  13. 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,

  14. 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.

  15. [Studies on quality control methods of nuxvomica].

    PubMed

    Huang, Xi-Ru; Sun, Ze-Dong; Cao, Dong; Wang, Shu-Yue

    2006-02-01

    Two quality control methods of nuxvomica were established for mutual. By selecting the appropriate measuring wavelength or wavelength range, the contents of strychnine and brucine in nuxvomica were determined without any preliminary separation by a new rapid spectrophotometry and a multi-wavelength linear regression spectrophotometry and with a computer program. The linear range of strychnine measured was 8.0-30.0 microg x mL(-1) (r = 0.999 9); The linear range of brucine measured was 7.0-31.2 microg x mL(-1) (r = 0.999 4). The average recoveries and relative standard deviations of strychnine and brucine were 98.18%-99.82%, 0.56%-1.54% and 100.5%-100.6%, 0.57%-0.62%, respectively. The methods are simple, rapid and reproducible, the interference of two components with each other may be eliminated and the methods are appropriate for quality control of nuxvomica. PMID:16826918

  16. 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 casecontrol 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 0.750.90) intake and CRC risk. Specific analysis for cabbage and broccoli yielded similar result. When separately analyzed, casecontrol 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 casecontrol 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

  17. Holographic interference method for studying residual stresses

    SciTech Connect

    Apal'kov, A A; Larkin, A I; Osintsev, A V; Odintsev, I N; Shchepinov, V P; Shchikanov, A Yu; Fontaine, J

    2007-06-30

    An original procedure is proposed for measuring residual stresses by combining the methods of holographic interferometry and probe holes. The difference of the orders of interference fringes for pairs of points on the surface of a body located on the directions of principal stresses is used as primary information. The results of the test experiment on measuring stresses in a plate deformed in the case of a simple shear and the results of measurement of residual welding stresses in two samples welded by a laser are presented. (holographic measurement methods)

  18. Comparative study of two commercially pure titanium casting methods

    PubMed Central

    RODRIGUES, Renata Cristina Silveira; FARIA, Adriana Claudia Lapria; ORSI, Iara Augusta; de MATTOS, Maria da Gloria Chiarello; MACEDO, Ana Paula; RIBEIRO, Ricardo Faria

    2010-01-01

    The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies evaluating the effects of casting methods on clasp behavior. Objective This study compared the occurrence of porosities and the retentive force of commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) removable partial denture circumferential clasps cast by induction/centrifugation and plasma/vacuum-pressure. Material and Methods 72 frameworks were cast from CP Ti (n=36) and Co-Cr alloy (n=36; control group). For each material, 18 frameworks were casted by electromagnetic induction and injected by centrifugation, whereas the other 18 were casted by plasma and injected by vacuum-pressure. For each casting method, three subgroups (n=6) were formed: 0.25 mm, 0.50 mm, and 0.75 mm undercuts. The specimens were radiographed and subjected to an insertion/removal test simulating 5 years of framework use. Data were analyzed by ANOVA and Tukey's to compare materials and cast methods (α=0.05). Results Three of 18 specimens of the induction/centrifugation group and 9 of 18 specimens of plasma/vacuum-pressure cast presented porosities, but only 1 and 7 specimens, respectively, were rejected for simulation test. For Co-Cr alloy, no defects were found. Comparing the casting methods, statistically significant differences (p<0.05) were observed only for the Co-Cr alloy with 0.25 mm and 0.50 mm undercuts. Significant differences were found for the 0.25 mm and 0.75 mm undercuts dependent on the material used. For the 0.50 mm undercut, significant differences were found when the materials were induction casted. Conclusion Although both casting methods produced satisfactory CP Ti RPD frameworks, the occurrence of porosities was greater in the plasma/vacuum-pressure than in the induction/centrifugation method, the latter resulting in higher clasp rigidity, generating higher retention force values. PMID:21085805

  19. 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.

  20. Cruciferous vegetables consumption and the risk of ovarian cancer: a meta-analysis of observational studies

    PubMed Central

    2014-01-01

    Background To quantify the effect of cruciferous vegetable consumption on the incidence of ovarian cancer by meta-analyzing the existing observational studies and provides quantitative and high-level evidence. Methods A detailed literature search of Medline and EMBASE for all relevant papers published. A meta-analysis was conducted for the association between cruciferous vegetable consumption and risk of ovarian cancer. Results A total of 4,306 cases in 375,562 controls in 11 independent studies were identified in this current meta-analysis. The result of this current meta-analysis, including 6 case-control and 5 cohort studies, indicated that cruciferous vegetable intake was associated with a reduced risk of ovarian cancer. Cruciferous vegetable consumption was associated with a reduced risk of ovarian cancer in case-control studies (RR=0.84; 95% CI, 0.75-0.94) but not in cohort studies (RR=1.00; 95% CI, 0.85-1.11). Conclusions The results from this meta-analysis of observational studies demonstrate that cruciferous vegetable consumption is a prospective factor of the ovarian cancer. However, more in-depth studies are warranted to report more detailed results, including other specific vegetables within the cruciferous vegetable family. Virtual slides The virtual slide (s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1116708293115581. PMID:24444040

  1. New method to study bacterial adhesion to meat.

    PubMed Central

    Piette, J P; Idziak, E S

    1989-01-01

    A new method was developed for the study of bacterial adhesion to meat surfaces. Thin slices of meat (40 microns thick) were inserted into a specially designed observation chamber. The meat slices were then exposed to a bacterial suspension (ca. 10(6) CFU.ml-1) to initiate adhesion (20 min of contact time) and subsequently rinsed to eliminate nonadherent bacteria. Because of the special chamber design, the disruptive force exerted on the bacteria during rinsing (shear stress) was uniform over the whole surface of the meat slices, was constant, and could be varied from 0 to 0.08 N.m-2. After being rinsed, the meat slices were stained with basic fuschin and observed under light microscopy to determine the number and distribution of adherent bacteria. This new method was used to study the adhesion of Acinetobacter strain LD2, a Lactobacillus sp., and Pseudomonas fluorescens to slices of beef fat and tendon. At 25 degrees C, most (greater than or equal to 99.9%) of the cells of the Lactobacillus sp. deposited on the meat were washed off the surface during rinsing (0.05 N.m-2), whereas a large number (ca. 10(5) CFU.cm-2) of Acinetobacter strain LD2 and P. fluorescens cells remained adherent. The extent of adhesion was similar on fat and tendon, and adherent bacteria were distributed evenly over the whole surface of the slices. This preliminary study indicates that the combined use of thin slices of meat and of the observation chamber provides us with the means to more accurately study bacterial adhesion to meat surfaces. Images PMID:2764565

  2. Occasions and the Reliability of Classroom Observations: Alternative Conceptualizations and Methods of Analysis

    ERIC Educational Resources Information Center

    Meyer, J. Patrick; Cash, Anne H.; Mashburn, Andrew

    2011-01-01

    Student-teacher interactions are dynamic relationships that change and evolve over the course of a school year. Measuring classroom quality through observations that focus on these interactions presents challenges when observations are conducted throughout the school year. Variability in observed scores could reflect true changes in the quality of

  3. 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.

  4. [The Audiovisual Method of Studying Russian.

    ERIC Educational Resources Information Center

    Grebenshchikov, V.

    1965-01-01

    Activity in the audiovisual teaching of French to students from Afro-Asiatic countries after the second World War at the Pedagogical Institute of St.-Cloud inspired Professor P. Guberin of Zagreb University to develop a course of 50 lessons for teaching Russian by this method. The use of tapes, films, and textbooks with records is treated here,

  5. [Preliminary study on pharmacodynamic evaluation method of Houpo formula particles].

    PubMed

    Ma, Lu; Shao, Li-Jie; Tang, Fang

    2014-04-01

    To discuss the feasibility of the pharmacodynamic evaluation method for traditional Chinese medicine (TCM) formula particles, with traditional decoction for reference and the intervention of Magnoliae Officinalis Cortex in rats with ulcerative colitis (UC). First of all, the similarity of traditional Magnoliae Officinalis Cortex decoction and formula particles of different manufacturers was defined by using the IR fingerprint. The UC rat model was established and given Houpo formula particles of different doses and manufacturers, with the decoction for reference, in order to observe disease activity index (DAI), colon mucosa damage index (CMDI), pathologic changes, nitric oxide (NO), endothdin (ET), substance P, vasoactive intestinal peptide (VIP). Their intervention effects on UC rats were compared to study the difference between Sanjiu and Tianjiang Houpo formula particles, in order to demonstrate the feasibility of the pharmacodynamic evaluation method for Houpo formula particles. According to the results, Houpo formula particles showed similar pharmacodynamic actions with the traditional decoction. The pharmacodynamic comparison of Houpo formula particles of different manufacturers showed no statistical significance. The experiment showed that on the basis of the TCM compounds, a prescription dismantlement study was conducted to define target points of various drugs. The traditional decoction was selected for reference in the comparison of corresponding formula particles for their pharmacodynamic equivalence. This method could avoid controversies about single or combined boiling of formula particles, and give objective comments on the pharmacodynamic effect of the formula particles. The method is proved to be feasible. PMID:25039188

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    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.

  7. Seismic Study of The Solar Interior: Inferences from SOI/MDI Observations during Solar Activity

    NASA Technical Reports Server (NTRS)

    Korzennik, Sylvain G.

    2003-01-01

    The principal investigator describes several types of solar research conducted during the reporting period and gives a statement of work to be performed in the following year. Research conducted during the reporting period includes: exhaustive analysis of observational and instrumental effects that might cause systematic errors in the characterization of high-degree p-modes; study of the structure, asphericity and dynamics of the solar interior from p-mode frequencies and frequency splittings; characterizing the solar rotation; Time-Distance inversion; and developing and using a new peak-fitting method for very long MDI time series at low degrees.

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

    SciTech Connect

    Koleśnik-Gray, Maria M.; Krstić, 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.

  9. Fireball observations in central Europe and western Australia: instruments, methods, and results

    NASA Astrophysics Data System (ADS)

    Spurny, P.

    2012-01-01

    Penetration of larger meteoroids through the atmosphere which gives rise to spectacular luminous events - fireballs or even superbolides - is of the greatest interest. Their registrations, especially photographic and newly also photoelectric recordings, provide excellent means to examine physical properties as well as the temporal and spatial distribution of extraterrestrial matter in near-Earth space. The most efficient tools for registration of these very scarce events are the fireball networks: systems covering large areas of the Earth's surface, with multiple camera stations designed to image a large fraction of the night sky. Such camera networks for fireball observations have been set up in several nations at various times in the past (European Fireball Network (EN) in the Czech Republic, Germany, Austria, and Slovakia; the Prairie Network in the USA; and the Meteorite Observation and Recovery Project (MORP) in Canada). Of these networks, only the European fireball network is still in operation, and this continuously since it was started up, but recently new networks were established in South-West Australia and in Ontario, Canada. The two main scientific aims of all these programs remain the same as in the very beginning - first, to constrain the flux of extraterrestrial material to the Earth over a range of masses, and second, to provide a statistically significant group of meteorites with accurate orbits. This contribution was focused on the current work and some particular recent results from the European Fireball Network, especially from its Czech part (current status is described, for example, by Spurny et al., 2006) and from the Desert Fireball Network in the Nullarbor Plains of South-West Australia (Bland, 2004; Spurny et al., 2012; and Bland et al., 2012). The mode of operation of both networks and the analysis methods used were described in detail and illustrated by some examples. Similarly, the most important recent results, especially from the Desert Fireball Network, such as the Bunburra Rockhole and Mason Gully meteorite falls, were presented in detail. These results are already published by Spurny et al. (2011, Mason Gully; 2012, Bunburra Rockhole) and Bland et al. (2009, Bunburra Rockhole).

  10. 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…

  11. 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

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

    PubMed

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

    2015-06-15

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

  13. Methods of Observing Variations in Physicians' Decisions: The Opportunities of Clinical Vignettes.

    PubMed

    Converse, Lara; Barrett, Kirsten; Rich, Eugene; Reschovsky, James

    2015-08-01

    To support their efforts to promote high quality and efficient care, policymakers need to better understand the key factors associated with variations in physicians' decisions, and in particular, physician deviations from evidence-based care. Clinical vignette survey instruments hold potential for research in this area as an approach that both allows for practical, large-scale study and overcomes the data quality challenges posed by analysis of clinical data. These surveys present respondents with a narrative description of a hypothetical patient case and solicit responses to one or more questions regarding the care of the patient. In this review, we describe various methods for measuring variations in physicians' decisions and highlight a range of design features researchers should consider when developing a clinical vignette survey. We conclude by identifying areas for future research. PMID:26105672

  14. 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

  15. 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]: 0.961.25). 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: 1.071.74), whereas no associations were shown by hospital-based case-control studies (OR: 0.86, 95% CI: 0.721.02) or cohort studies (OR?=?1.01, 95% CI?=?0.911.13). 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

  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. 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.

  18. Tropospheric CO Observations Using IASI datasets and an Optimal Estimation Retrieval Method

    NASA Astrophysics Data System (ADS)

    Illingworth, S. M.

    2009-04-01

    Carbon monoxide (CO) in the troposphere acts as a marker of large-scale influences of pollution on both the regional and global scale, whilst acting as a reference source for incomplete combustion. Through its reactions with the hydroxyl radical OH, the concentration of CO is also related to the oxidizing capacity of the troposphere, hence providing a chemical marker for the "local" chemical environment and its state. Investigations into perturbations of the sources, sinks and net surface fluxes of CO are therefore of increasing importance. CO exhibits strong locally elevated concentrations in the vicinity of sources due to its relatively short life time of weeks to months. Global measurements of CO from satellites will therefore allow to identify the main source regions and to quantify their source strength. The Infrared Atmospheric Sounding Interferometer (IASI) is a high-resolution (0.25 cm-1 unapodized) Michelson interferometer which was launched in 2007 on the European polar Meteorological Operational Platform (METEOP-1) satellite. The IASI instrument has a swath of about 2200 km, ensuring 99% global coverage twice a day, and is the first of a series of three instruments launched every five years, ensuring a continuity of data for a planned period of 15 years. The IASI instrument thus offers the possibility of high-spectral resolution infrared monitoring of CO over a very long time period. This work presents a new Optimal Estimation Method (OEM) retrieval of CO profiles in the mid-troposphere from observations of the IASI instrument. First retrieval results, as well as a validation of these results with ground-based sites and other satellites are included, and error characterization as well as the effects of noise in the retrievals is also discussed.

  19. 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.

  20. 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

  1. Qualitative study of three cell culture methods.

    PubMed

    Wang, Aiguo; Xia, Tao; Ran, Peng; Chen, Xuemin; Nuessler, Andreas K

    2002-01-01

    Primary rat hepatocytes were cultured using different in vitro models and the enzyme leakage, albumin secretion, and cytochrome P450 1A (CYP 1A) activity were observed. The results showed that the level of LDH was decreased over time in culture. However, on day 5, LDH showed a significant increase in monolayer culture (MC) while after day 8 no LDH was detectable in sandwich culture (SC). The levels of AST and ALT did not change significantly over the investigated time. The CYP 1A activity was gradually decreased in a time-dependent manner in MC and SC. The decline of CYP 1A was faster in MC than in SC. This effect was partially reversed by using cytochrome P450 (CYP450) inducer such as Omeprazol and 3-methylcholanthrene (3-MC) and the CYP 1A induction was always higher in MC than in SC. In bioreactor basic CYP 1A activity was preserved over 2 weeks and the highest albumin production was observed in bioreactor followed by SC and MC. Taken together, it was indicated each investigated model had its advantages and disadvantages. It was also underlined that various in vitro models may address different questions. PMID:12674760

  2. Medical Home Characteristics and Asthma Control: A Prospective, Observational Cohort Study Protocol

    PubMed Central

    Sills, Marion R.; Kwan, Bethany M.; Yawn, Barbara P.; Sauer, Brian C.; Fairclough, Diane L.; Federico, Monica J.; Juarez-Colunga, Elizabeth; Schilling, Lisa M.

    2013-01-01

    Background: This paper describes the methods for an observational comparative effectiveness research study designed to test the association between practice-level medical home characteristics and asthma control in children and adults receiving care in safety-net primary care practices. Methods: This is a prospective, longitudinal cohort study, utilizing survey methodologies and secondary analysis of existing structured clinical, administrative, and claims data. The Scalable Architecture for Federated Translational Inquiries Network (SAFTINet) is a safety net-oriented, primary care practice-based research network, with federated databases containing electronic health record (EHR) and Medicaid claims data. Data from approximately 20,000 patients from 50 practices in four healthcare organizations will be included. Practice-level medical home characteristics will be correlated with patient-level asthma outcomes, controlling for potential confounding variables, using a clustered design. Linear and non-linear mixed models will be used for analysis. Study inception was July 1, 2012. A causal graph theory approach was used to guide covariate selection to control for bias and confounding. Discussion: Strengths of this design include a priori specification of hypotheses and methods, a large sample of patients with asthma cared for in safety-net practices, the study of real-world variations in the implementation of the medical home concept, and the innovative use of a combination of claims data, patient-reported data, clinical data from EHRs, and practice-level surveys. We address limitations in causal inference using theory, design and analysis. PMID:25848577

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

    PubMed

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

    2014-09-01

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

  4. Attention-Deficit/Hyperactivity Disorder Drugs and Growth: An Italian Prospective Observational Study

    PubMed Central

    Germinario, Elena A.P.; Arcieri, Romano; Bonati, Maurizio; Zuddas, Alessandro; Masi, Gabriele; Vella, Stefano; Chiarotti, Flavia

    2013-01-01

    Abstract Objective This study was conducted to assess the long-term effect of methylphenidate (MPH) or atomoxetine (ATX) on growth in attention-deficit/hyperactivity disorder (ADHD) drug-nave children. Design The study was an observational, post-marketing, fourth phase study. Methods Data on height and weight were collected at baseline and every 6 months up to 24 months. Results Both ATX and MPH lead to decreased height gain (assessed by means of z-scores); the effect was significantly higher for ATX than for MPH. At any time, height z-score decrease in the ATX group was higher than the corresponding decrease observed in the MPH group, but the difference was significantly relevant only during the first year of treatment. An increment of average weight was observed both in patients treated with MPH and in those treated with ATX. However, using Tanner's percentile, a subset of patients showed a degree of growth lower than expected. This negative effect was significantly higher for ATX than for MPH. Conclusions We conclude that ADHD drugs show a negative effect on linear growth in children in middle term. Such effect appears more evident for ATX than for MPH. PMID:24024538

  5. Studies of the Mesosphere and Lower Thermosphere Dynamics Using Satellite Observations and Numerical Models

    NASA Astrophysics Data System (ADS)

    Liu, H.

    2011-12-01

    NASA UARS and TIMED satellites have enabled global and long-term monitoring of the Earth's middle and upper atmosphere, and thus an unprecedented and comprehensive quantification of mesosphere and lower thermosphere (MLT) variability on large spatial scales and time scales ranging from days to decades. These observations have led to improved theoretical understanding of the MLT dynamics, by inspiring development/improvement of numerical models and analysis methods, and providing more observational constraints to the models. Several studies within the last decade will be reviewed as examples: The observation of the seasonal variation of propagating planetary waves (5-7-day wave and quasi-2-day wave) in the MLT, and TIME-GCM simulations to understand the cause of the seasonality; the study of short-term tidal variability using TIMED satellite, ground-based, and TIME-GCM; the numerical study of the ionospheric effects of these MLT short-term variabilities; and determination of the gravity wave forcing, which is the most dominant driver of MLT circulation, from satellite and ground-based wind measurements, using a momentum balance relation tested by WACCM. Challenges posed by current and future model development will also be discussed, as initiatives for future missions.

  6. 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

  7. The observed growth of massive galaxy clusters - I. Statistical methods and cosmological constraints

    NASA Astrophysics Data System (ADS)

    Mantz, A.; Allen, S. W.; Rapetti, D.; Ebeling, H.

    2010-08-01

    This is the first of a series of papers in which we derive simultaneous constraints on cosmological parameters and X-ray scaling relations using observations of the growth of massive, X-ray flux-selected galaxy clusters. Our data set consists of 238 cluster detections from the ROSAT All-Sky Survey, and incorporates follow-up observations of 94 of those clusters using the Chandra X-ray Observatory or ROSAT. Here we describe and implement a new statistical framework required to self-consistently produce simultaneous constraints on cosmology and scaling relations from such data, and present results on models of dark energy. In spatially flat models with a constant dark energy equation of state, w, the cluster data yield ?m = 0.23 +/- 0.04,?8 = 0.82 +/- 0.05 and w = -1.01 +/- 0.20, incorporating standard priors on the Hubble parameter and mean baryon density of the Universe, and marginalizing over conservative allowances for systematic uncertainties. These constraints agree well and are competitive with independent data in the form of cosmic microwave background anisotropies, type Ia supernovae, cluster gas mass fractions, baryon acoustic oscillations, galaxy redshift surveys and cosmic shear. The combination of our data with current microwave background, supernova, gas mass fraction and baryon acoustic oscillation data yields ?m = 0.27 +/- 0.02,?8 = 0.79 +/- 0.03 and w = -0.96 +/- 0.06 for flat, constant w models. The combined data also allow us to investigate evolving w models. Marginalizing over transition redshifts in the range 0.05-1, we constrain the equation of state at late and early times to be respectively w0 = -0.88 +/- 0.21 and wet = -1.05+0.20-0.36, again including conservative systematic allowances. The combined data provide constraints equivalent to a Dark Energy Task Force figure of merit of 15.5. Our results highlight the power of X-ray studies, which enable the straightforward production of large, complete and pure cluster samples and admit tight scaling relations, to constrain cosmology. However, the new statistical framework we apply to this task is equally applicable to cluster studies at other wavelengths.

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

    PubMed Central

    Chang, Michelle; Quinn, Jessica; Capili, Bernadette

    2014-01-01

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

  9. An observational study of a shallow gravity current triggered by katabatic flow

    NASA Astrophysics Data System (ADS)

    Adachi, A.; Clark, W.; Hartten, L.; Gage, K.; Kobayashi, T.

    2004-11-01

    Observations from a wind profiler and a meteorological tower are utilized to study the evolution of a gravity current that passed over the Meteorological Research Institute's (MRI) field site in Tsukuba, Japan. The gravity current was created by katabatic flow originating on the mountainous slopes west of the field site. The passage of the shallow current was marked by a pronounced pressure disturbance and was accompanied by vertical circulations seen in the tower and profiler data. Direct vertical-beam measurements are difficult, especially at low heights during high-gradient events like density currents. In this study vertical velocities from the profiler are derived from the four oblique beams by use of the Minimizing the Variance of the Differences (MVD) method. The vertical velocities derived from the MVD method agree well with in situ vertical velocities measured by a sonic anemometer on the tower. The gravity current is analyzed with surface observations, the wind profiler/RASS and tower-mounted instruments. Observations from the profiler/RASS and the tower-mounted instruments illustrate the structure of the gravity current in both wind and temperature fields. The profiler data reveal that there were three regions of waves in the vertical velocity field: lee-type waves, a solitary wave and Kelvin-Helmholtz waves. The lee-type waves in the head region of the gravity current seem to have been generated by the gravity current acting as an obstacle to prefrontal flow. The solitary wave was formed from the elevated head of the gravity current that separated from the feeder flow. Profiler vertical-motion observations resolve this wave and enable us to classify it as a Benjamin-Davis-Ono (BDO) type solitary wave. The ducting mechanism that enabled the solitary wave to propagate is also revealed from the wind profiler/RASS measurements. The combination of high-resolution instruments at the MRI site allow us to develop a uniquely detailed picture of a shallow gravity current structure.

  10. 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.

  11. Automated Parameter Studies Using a Cartesian Method

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.; Aftosimis, Michael J.; Nemec, Marian

    2004-01-01

    Computational Fluid Dynamics (CFD) is now routinely used to analyze isolated points in a design space by performing steady-state computations at fixed flight conditions (Mach number, angle of attack, sideslip), for a fixed geometric configuration of interest. This "point analysis" provides detailed information about the flowfield, which aides an engineer in understanding, or correcting, a design. A point analysis is typically performed using high fidelity methods at a handful of critical design points, e.g. a cruise or landing configuration, or a sample of points along a flight trajectory.

  12. Intraspinal pressure and spinal cord perfusion pressure after spinal cord injury: an observational study.

    PubMed

    Varsos, Georgios V; Werndle, Melissa C; Czosnyka, Zofia H; Smielewski, Peter; Kolias, Angelos G; Phang, Isaac; Saadoun, Samira; Bell, B Anthony; Zoumprouli, Argyro; Papadopoulos, Marios C; Czosnyka, Marek

    2015-12-01

    OBJECT In contrast to intracranial pressure (ICP) in traumatic brain injury (TBI), intraspinal pressure (ISP) after traumatic spinal cord injury (TSCI) has not received the same attention in terms of waveform analysis. Based on a recently introduced technique for continuous monitoring of ISP, here the morphological characteristics of ISP are observationally described. It was hypothesized that the waveform analysis method used to assess ICP could be similarly applied to ISP. METHODS Data included continuous recordings of ISP and arterial blood pressure (ABP) in 18 patients with severe TSCI. RESULTS The morphology of the ISP pulse waveform resembled the ICP waveform shape and was composed of 3 peaks representing percussion, tidal, and dicrotic waves. Spectral analysis demonstrated the presence of slow, respiratory, and pulse waves at different frequencies. The pulse amplitude of ISP was proportional to the mean ISP, suggesting a similar exponential pressure-volume relationship as in the intracerebral space. The interaction between the slow waves of ISP and ABP is capable of characterizing the spinal autoregulatory capacity. CONCLUSIONS This preliminary observational study confirms morphological and spectral similarities between ISP in TSCI and ICP. Therefore, the known methods used for ICP waveform analysis could be transferred to ISP analysis and, upon verification, potentially used for monitoring TSCI patients. PMID:26273764

  13. Establishing a ultraviolet radiation observational network and enhancing the study on ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Bai, Jianhui; Wang, Gengchen

    2003-09-01

    On the basis of analyzing observational data on solar radiation, meteorological parameters, and total ozone amount for the period of January 1990 to December 1991 in the Beijing area, an empirical calculation method for ultraviolet radiation (UV) in clear sky is obtained. The results show that the calculated values agree well with the observed, with maximum relative bias of 6.2% and mean relative bias for 24 months of 1.9%. Good results are also obtained when this method is applied in Guangzhou and Mohe districts. The long-term variation of UV radiation in clear sky over the Beijing area from 1979 to 1998 is calculated, and the UV variation trends and causes are discussed: direct and indirect UV energy absorption by increasing pollutants in the troposphere may have caused the UV decrease in clear sky in the last 20 years. With the enhancement of peoples quality of life and awareness of health, it will be valuable and practical to provid UV forecasts for typical cities and rural areas. So, we should develop and enhance UV study in systematic monitoring, forecasting, and developing a good and feasible method for UV radiation reporting in China, especially for big cities.

  14. Feeling strong: a parse research method study.

    PubMed

    Doucet, Thomas J

    2012-01-01

    In this article the author reports findings from a Parse research study on the experience of feeling strong with 10 participants living in community. The central finding of the study is the structure: Feeling strong is propelling resolutely amid adversity, as jubilant fulfilling assuredness surfaces with discerning spirited envisioning with treasured alliances. The findings are discussed in relation to the humanbecoming school of thought and extant literature. PMID:22228526

  15. 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

  16. 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. PMID:26734863

  17. Systematically missing confounders in individual participant data meta-analysis of observational cohort studies.

    PubMed

    Jackson, Dan; White, Ian; Kostis, J B; Wilson, A C; Folsom, A R; Wu, K; Chambless, L; Benderly, M; Goldbourt, U; Willeit, J; Kiechl, S; Yarnell, J W G; Sweetnam, P M; Elwood, P C; Cushman, M; Psaty, B M; Tracy, R P; Tybjaerg-Hansen, A; Haverkate, F; de Maat, M P M; Thompson, S G; Fowkes, F G R; Lee, A J; Smith, F B; Salomaa, V; Harald, K; Rasi, V; Vahtera, E; Jousilahti, P; D'Agostino, R; Kannel, W B; Wilson, P W F; Tofler, G; Levy, D; Marchioli, R; Valagussa, F; Rosengren, A; Wilhelmsen, L; Lappas, G; Eriksson, H; Cremer, P; Nagel, D; Curb, J D; Rodriguez, B; Yano, K; Salonen, J T; Nyyssönen, K; Tuomainen, T-P; Hedblad, B; Engström, G; Berglund, G; Loewel, H; Koenig, W; Hense, H W; Meade, T W; Cooper, J A; De Stavola, B; Knottenbelt, C; Miller, G J; Cooper, J A; Bauer, K A; Rosenberg, R D; Sato, S; Kitamura, A; Naito, Y; Iso, H; Salomaa, V; Harald, K; Rasi, V; Vahtera, E; Jousilahti, P; Palosuo, T; Ducimetiere, P; Amouyel, P; Arveiler, D; Evans, A E; Ferrieres, J; Juhan-Vague, I; Bingham, A; Schulte, H; Assmann, G; Cantin, B; Lamarche, B; Despres, J-P; Dagenais, G R; Tunstall-Pedoe, H; Lowe, G D O; Woodward, M; Ben-Shlomo, Y; Davey Smith, G; Palmieri, V; Yeh, J L; Meade, T W; Rudnicka, A; Brennan, P; Knottenbelt, C; Cooper, J A; Ridker, P; Rodeghiero, F; Tosetto, A; Shepherd, J; Lowe, G D O; Ford, I; Robertson, M; Brunner, E; Shipley, M; Feskens, E J M; Di Angelantonio, E; Kaptoge, S; Lewington, S; Lowe, G D O; Sarwar, N; Thompson, S G; Walker, M; Watson, S; White, I R; Wood, A M; Danesh, J

    2009-04-15

    One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the a