Sample records for observational studies methods

  1. Observational Studies

    NSDL National Science Digital Library

    Abebe, Asheber

    This lesson on observational studies discusses the nature of such studies, the relationships between various data sets, and regression. Graphs illustrate the relationships, and exercises at the end test the user's comprehension and understanding. It is taken from the online textbook for Western Michigan University online introductory stats course.

  2. Monitoring of earthquake processes by passive and active EM methods. An observational study

    Microsoft Academic Search

    G. Zhao; Z. Yan; W. Lifeng; J. Wang; J. Tang; Q. Xiao; X. Chen; J. Zhao

    2009-01-01

    Three experiments are carried out from the Institute of Geology, CEA research group to study earthquake process by using different electromagnetic (EM) methods in recent years. Several earthquakes did occur during the observational period and EM anomalies were recorded before the main shocks. Our observation at 20 km away from the epicenter of Zhangbei MS6.2 earthquake of January 10, 1998

  3. Validation and statistical power comparison of methods for analyzing free-response observer performance studies

    PubMed Central

    Chakraborty, Dev P.

    2009-01-01

    Rationale and Objectives The aim of this work was to validate and compare the statistical powers of proposed methods for analyzing free-response data using a search-model based simulator. Materials and Methods A free-response data simulator is described that can model a single reader interpreting the same cases in two modalities, or two CAD algorithms, or two human observers, interpreting the same cases in one modality. A variance components model, analogous to the Roe and Metz receiver operating characteristic (ROC) data simulator, is described, that models intra-case and inter-modality correlations in free-response studies. Two generic observers were simulated: a quasi-human observer and a quasi-CAD algorithm. Null hypothesis (NH) validity and statistical powers of ROC, jackknife alternative free-response operating characteristic (JAFROC), a variant of JAFROC termed JAFROC-1, initial detection and candidate analysis (IDCA) and a non-parametric (NP) approach were investigated. Results All methods had valid NH behavior over a wide range of simulator parameters. For equal numbers of normal and abnormal cases, for the human observer, the statistical power ranking of the methods was JAFROC-1 > JAFROC > (IDCA ~ NP) > ROC. For the CAD algorithm the ranking was (NP ~ IDCA) > (JAFROC-1~JAFROC) > ROC. In either case the statistical power of the highest ranked method exceeded that of the lowest ranked method by about a factor of two. Dependence of statistical power on simulator parameters followed expected trends. For data sets with more abnormal cases than normal cases, JAFROC-1 power significantly exceeded JAFROC power. Conclusion Based on this work the recommendation is to use JAFROC-1 for human observers (including human-observers with CAD assist) and the NP method for evaluating CAD algorithms. PMID:19000872

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

    NASA Technical Reports Server (NTRS)

    Edberg, S. J.

    1983-01-01

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

  5. Extension of Kaplan-Meier methods in observational studies with time-varying treatment

    PubMed Central

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

    2011-01-01

    Objectives Inverse probability of treatment weighted (IPTW) Kaplan-Meier estimates have been developed to compare two treatments in the presence of confounders in observational studies. Recently, stabilized weights were developed to reduce the influence of extreme IPTW weights in estimating treatment effects. The objective of this paper was to use adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests to examine the effect of a treatment which varies over time in an observational study. Methods In this paper, we propose stabilized weight (SW) adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests when the treatment is time-varying over the follow-up period. We applied these new methods in examining the effect of an anti-platelet agent, clopidogrel, on subsequent events, including bleeding, myocardial infarction, and death after a Drug-Eluting Stent was implanted into a coronary artery. In this population, clopidogrel use may change over time based on patients' behavior (e.g., non-adherence) and physicians' recommendations (e.g., end of duration of therapy). Consequently, clopidogrel use was treated as a time-varying variable. Results We demonstrate that 1) the sample sizes at three chosen time points are almost identical in the original and weighted datasets, and 2) the covariates between patients on and off clopidogrel were well balanced after SWs were applied to the original samples. Conclusions The SW-adjusted Kaplan-Meier estimates and modified log-rank and Wilcoxon tests are useful in presenting and comparing survival functions for time-varying treatments in observational studies while adjusting for known confounders. PMID:22264985

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

    PubMed

    Colditz, Graham A

    2010-01-01

    The impact of study design on the results of medical research has long been an area of both substantial debate and a smaller body of empirical research. Examples come from many disciplines within clinical and public health research. Among the early major contributions in the 1970s was work by Mosteller and colleagues (Gilbert et al., 1997), who noted that innovations in surgery and anesthesia showed greater gains than standard therapy when nonrandomized, controlled trials were evaluated compared with the gains reported in randomized, controlled trials. More recently, we and others have evaluated the impact of design in medical and surgical research, and concluded that the mean gain comparing new therapies to established therapies was biased by study design in nonrandomized trials (Colditz et al., 1989; Miller et al., 1989). Benson and Hartz (2000) conducted a study in which they focused only on studies reported after 1985. On the basis of 136 reports of 19 diverse treatments, Benson and Hartz concluded that in only 2 of the 19 analyses did the combined data from the observational studies lie outside the 95% confidence interval for the combined data from the randomized trials. A similar study drew only on data reported from 1991 to 1995, which showed remarkably similar results among observational studies and randomized, controlled trials (Concato et al., 2000). These more recent data suggest that advancing the study design and analytic methods may reduce bias in some evaluations of medical and public health interventions. Such methods apply not only to the original studies, but also to the approaches that are taken to quantitatively combine results by using meta-analytic approaches such as random effects meta-regression, Bayesian meta-analysis, and the like (Normand, 1999). By focusing attention on thorough data analysis, design issues can be understood and their impact or bias can be estimated, on average, and then ideally accounted for in the interpretation of data. Before discussing dietary data, let us first consider some of the more clearly delineated preventive exposures. Issues of study design have been addressed in terms of combining randomized trials and observational studies in evaluating preventive interventions such as Bacillus Calmette-Guerin vaccination (Colditz et al., 1994) and mammography screening (Desmissie et al., 1998). When one is interpreting the apparent heterogeneity in the results, it is important to step back and ask what is the relationship being evaluated under these different study designs? For example, a randomized, controlled trial uses the intention-to-treat analysis to preserve the merit of randomization. Such an analysis does not evaluate the exposure-disease relationship, but rather examines the impact of offering a new therapy versus an alternative therapy (regardless of adherence to the intervention, or control or placebo). On the other hand, a case-control study or a prospective cohort study will evaluate the impact of the screening test among those participants who were screened as compared with those who were never screened. In prevention studies, the design raises major issues of the timing of the exposure in the natural history of disease and also the adherence to therapy by healthy research volunteers. Case-control studies of preventive interventions such as screening mammography and prospective population-based studies of pap smears have capitalized on this variation in time since the last screen to evaluate the protective interval for a screening test (IARC Work Group, 1986). In contrast, a trial must choose a level of exposure, such as annual mammography screenings or colon screenings every 10 years with a colonoscopy, regardless of the evolving evidence on the duration of protection after a negative screening test. Continuing with the mammography example, a detailed study by Demissie and colleagues (1998) combined data from seven randomized trials and six case-control studies that investigated the association between participation in breast cancer screening programs and brea

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

    PubMed Central

    2014-01-01

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

  8. A study of the pointed observation methods and sensitivity of HXMT

    NASA Astrophysics Data System (ADS)

    Jin, Jing; Chen, Yong; Zhang, Shuang-Nan; Zhang, Shu; Li, Xin-Qiao; Li, Gang

    2010-01-01

    The Hard X-ray Modulation Telescope (HXMT) is an X-ray astronomy satellite consisting of three slat-collimated instruments, the High Energy X-ray Instrument (HE), the Medium Energy X-ray Instrument (ME), and the Low Energy X-ray Instrument (LE). HXMT will carry out an all sky survey and make pointed observations in the 1-250 keV energy band. In order to get the source and background fluxes simultaneously in the pointed observations, two methods, i.e., the combined field of view (FOV) method and the off-axis pointing method are proposed in this paper. Comprehensive analyses of the sensitivities of the three instruments by using these two methods are presented, respectively. It is found that the off-axis pointing method has a higher sensitivity for HE and ME but a lower sensitivity for LE. Since the axes of the three instruments are aligned along the same direction, the off-axis pointing method is recommended as the main method in the pointed observation for HXMT; the combined FOV method can be used when LE is the most relevant instrument in order to satisfy the scientific objective of the observation.

  9. Monitoring of earthquake processes by passive and active EM methods. An observational study

    NASA Astrophysics Data System (ADS)

    Zhao, G.; Yan, Z.; Lifeng, W.; Wang, J.; Tang, J.; Xiao, Q.; Chen, X.; Zhao, J.

    2009-12-01

    Three experiments are carried out from the Institute of Geology, CEA research group to study earthquake process by using different electromagnetic (EM) methods in recent years. Several earthquakes did occur during the observational period and EM anomalies were recorded before the main shocks. Our observation at 20 km away from the epicenter of Zhangbei MS6.2 earthquake of January 10, 1998 shows that the apparent resistivity decreases in the strike direction before and/or during the earthquake. In the same time the resistivity increases in the decline direction. This anomalous variation in apparent resistivity reaches about 20%. The apparent resistivity at the epicentral area decrease in the strike and decline directions before and/or during the earthquake and increase after the shock. The experiments using active low frequency electromagnetic signals were carried out in 1999 and show that the resolution and stability of electric and magnetic spectra are improved. The spectra of electric and magnetic fields and apparent resistivity at the Baodi station began to anomalously change two days before the Qian’an MS4.2 earthquake of May 12 with 120 km distant to the station. The anomalous variation of electric and magnetic spectra is about twice as great as normal variation and the apparent resistivity changes is about 20%. The measurements in active seismic area of Yunnan province in the year 2005 indicate that the electric and magnetic spectra anomalously change by one order before the Taoyuan MS3.6 earthquake of September 21 in about 100 km away from the observatories. But the measurements at the sites in Beijing area, 2 000 km away from the epicenter did not show any anomalous behavior. Our observation experience show presence of EM anomalous variations in different frequencies detected near to the epicentral areas of several earthquakes. We are considering that these practical examples and many other reported, suggest that the ground electromagnetic methods could play an important role in the understanding the EM phenomena related to the earthquake process.

  10. 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…

  11. 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).

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

    SciTech Connect

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

    1990-10-01

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

  13. Ethnographic Observation Methods

    E-print Network

    expertise Usability, HCI, methods Interface design Clinician characteristics Medical expertise Clinical role for error? Identify opportunities What can be done better? #12;Goals Describe clinicians Hospitalists, specialists, surgeons, nurses, EMS personnel, support. Describe clinical environments Ambulatory, hospital

  14. Development of a method to study positron diffusion in metals by the observation of positronium negative ions

    NASA Astrophysics Data System (ADS)

    Suzuki, Takuji; Terabe, Hiroki; Iida, Shimpei; Yamashita, Takashi; Nagashima, Yasuyuki

    2014-09-01

    We have developed a new method to study positron diffusion in metals. In this method, we observe positronium negative ions emitted from the sample surfaces after coating with alkali-metals to evaluate the yields of the positrons which return to the surfaces. ?-rays from the ions accelerated using an electric field are clearly distinguished from those emitted from pair-annihilation of positrons in the bulk or on the surface and self-annihilation of emitted positronium atoms. Reliable studies on positron diffusion in metals have been enabled by this method.

  15. 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...

  16. 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.

  17. A most stubborn bias: no adjustment method fully resolves confounding by indication in observational studies

    Microsoft Academic Search

    Jaclyn L. F. Bosco; Rebecca A. Silliman; Soe Soe Thwin; Ann M. Geiger; Diana S. M. Buist; Marianne N. Prout; Marianne Ulcickas Yood; Reina Haque; Feifei Wei; Timothy L. Lash

    2010-01-01

    ObjectiveTo evaluate the effectiveness of methods that control for confounding by indication, we compared breast cancer recurrence rates among women receiving adjuvant chemotherapy with those who did not.

  18. Approaches to Use of Observational Methods of a Study of Parent-Child Interaction.

    ERIC Educational Resources Information Center

    Baumrind, Diana

    The methodology discussed is used in ongoing research to contrast the effectiveness of several patterns of parental authority with the same children at different ages. The first characteristic of these methods is the use of trait and behavior ratings to assess dispositional tendencies. The construct of a dispositional trait is used to account for…

  19. Observation method for mathematical graphology

    Microsoft Academic Search

    Kazuo Toraichi; Takahiko Horiuchi; Ryoji Haruki

    1995-01-01

    An observation method for mathematical graphology is proposed. The motivation of mathematical graphology is to realize graphological information processing on a machine. Furthermore, mathematical graphology aims to construct a new information theory for visual communication. In order to construct the mathematical model this paper focuses on the observation process, which is the first stage in the model. Based on the

  20. Studies That Observe Humans

    MedlinePLUS

    ... may also be called a follow-up or longitudinal study.) A cohort study usually observes groups and compares ... factors affect their outcomes. Cohort studies can be prospective , meaning that the researchers select a group and ...

  1. An Observational Measure of Children's Behavioural Style: Evidence Supporting a Multi-Method Approach to Studying Temperament

    ERIC Educational Resources Information Center

    Karp, Jennifer; Serbin, Lisa A.; Stack, Dale M.; Schwartzman, Alex E.

    2004-01-01

    This study demonstrates the potential utility of the Behavioural Style Observational System (BSOS) as a new observational measure of children's behavioural style. The BSOS is an objective, short and easy to use measure that can be readily adapted to a variety of home and laboratory situations. In the present study, 160 mother-child dyads from the…

  2. Observing system simulation experiments with multiple methods

    NASA Astrophysics Data System (ADS)

    Ishibashi, Toshiyuki

    2014-11-01

    An observing System Simulation Experiment (OSSE) is a method to evaluate impacts of hypothetical observing systems on analysis and forecast accuracy in numerical weather prediction (NWP) systems. Since OSSE requires simulations of hypothetical observations, uncertainty of OSSE results is generally larger than that of observing system experiments (OSEs). To reduce such uncertainty, OSSEs for existing observing systems are often carried out as calibration of the OSSE system. The purpose of this study is to achieve reliable OSSE results based on results of OSSEs with multiple methods. There are three types of OSSE methods. The first one is the sensitivity observing system experiment (SOSE) based OSSE (SOSEOSSE). The second one is the ensemble of data assimilation cycles (ENDA) based OSSE (ENDA-OSSE). The third one is the nature-run (NR) based OSSE (NR-OSSE). These three OSSE methods have very different properties. The NROSSE evaluates hypothetical observations in a virtual (hypothetical) world, NR. The ENDA-OSSE is very simple method but has a sampling error problem due to a small size ensemble. The SOSE-OSSE requires a very highly accurate analysis field as a pseudo truth of the real atmosphere. We construct these three types of OSSE methods in the Japan meteorological Agency (JMA) global 4D-Var experimental system. In the conference, we will present initial results of these OSSE systems and their comparisons.

  3. 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

  4. What Observational Studies Can Offer Decision Makers

    Microsoft Academic Search

    Nick Black

    1999-01-01

    Observational studies, for example cohort and case-control studies in which patients are allocated treatment on a non-random basis, are thought by some investigators to be flawed. This view results from the fact that, unlike experimental methods (randomized controlled trials; RCTs), the results of such observational studies are vulnerable to confounding. However, this view assumes that satisfactory adjustment of differences in

  5. The Network Analytic Extraction of Community Structures to Scale-Up Ethnographic Observations: Integrating Quantitative and Qualitative Methods to Study Field Differences in Scientific Communication

    E-print Network

    Velden, Theresa

    2012-01-01

    The scientific community of researchers in a research specialty is an important unit of analysis for understanding the field specific shaping of scientific communication practices. These scientific communities are, however, a challenging unit of analysis to capture and compare because they overlap, have fuzzy boundaries, and evolve over time. We describe a mixed method approach that reveals the complexities of these communities through examination of their publication networks in combination with ethnographic field studies. We suggest that the structures revealed indicate overlapping sub-communities within a research specialty and we provide evidence that they differ in disciplinary orientation and research practices. By mapping the community structures of scientific fields we aim to increase confidence about the domain of validity of ethnographic observations thereby enabling the systematic study of field differences. The network analytic components of our approach include methods to optimize the delineation...

  6. Changes in nurses’ work associated with computerised information systems: Opportunities for international comparative studies using the revised Work Observation Method By Activity Timing (WOMBAT)

    PubMed Central

    Westbrook, Johanna I.; Creswick, Nerida J.; Duffield, Christine; Li, Ling; Dunsmuir, William T. M.

    2012-01-01

    An important step in advancing global health through informatics is to understand how systems support health professionals to deliver improved services to patients. Studies in several countries have highlighted the potential for clinical information systems to change patterns of work and communication, and in particular have raised concerns that they reduce nurses’ time in direct care. However measuring the effects of systems on work is challenging and comparisons across studies have been hindered by a lack of standardised definitions and measurement tools. This paper describes the Work Observation Method by Activity Time (WOMBAT) technique version 1.0 and the ways in which the data generated can describe different aspects of health professionals’ work. In 2011 a revised WOMBAT version 2.0 was developed specifically to facilitate its use by research teams in different countries. The new features provide opportunities for international comparative studies of nurses’ work to be conducted. PMID:24199139

  7. Observational Studies and Experiments Activity

    NSDL National Science Digital Library

    2009-07-21

    This activity will allow students to learn the difference between observational studies and experiments, with emphasis on the importance of cause-and-effect relationships. The activity will also familiarize students with key terms such as factors, treatments, retrospective and prospective studies, etc. This is an easy to follow lesson plan for those teaching a course in statistics.

  8. Calibrating sensitivity analyses to observed covariates in observational studies.

    PubMed

    Hsu, Jesse Y; Small, Dylan S

    2013-12-01

    In medical sciences, statistical analyses based on observational studies are common phenomena. One peril of drawing inferences about the effect of a treatment on subjects using observational studies is the lack of randomized assignment of subjects to the treatment. After adjusting for measured pretreatment covariates, perhaps by matching, a sensitivity analysis examines the impact of an unobserved covariate, u, in an observational study. One type of sensitivity analysis uses two sensitivity parameters to measure the degree of departure of an observational study from randomized assignment. One sensitivity parameter relates u to treatment and the other relates u to response. For subject matter experts, it may be difficult to specify plausible ranges of values for the sensitivity parameters on their absolute scales. We propose an approach that calibrates the values of the sensitivity parameters to the observed covariates and is more interpretable to subject matter experts. We will illustrate our method using data from the U.S. National Health and Nutrition Examination Survey regarding the relationship between cigarette smoking and blood lead levels. PMID:24328711

  9. 3D evaluation of postoperative swelling using two different cooling methods following orthognathic surgery: a randomised observer blind prospective pilot study.

    PubMed

    Rana, M; Gellrich, N C; Joos, U; Piffkó, J; Kater, W

    2011-07-01

    Orthognathic surgery is associated with side effects including severe postoperative swelling, pain, neurological dysfunction and trismus. The beneficial effects of localised cold treatment on postoperative swelling have been described. Topographical considerations make it difficult to quantify facial swelling. A new and promising method to measure facial swelling seems to be optical face scanning. This study aimed to evaluate the 3D optical scanner to measure soft tissue swelling following orthognathic surgery. Postoperative swelling was treated either with conventional cooling by cold packs or with the water-circulating cooling device Hilotherm Clinic. Secondary endpoints in each group included postoperative pain, neurological complaints, duration of hospital stay, trismus and patient satisfaction. The use of the cooling device by Hilotherm significantly reduced postoperative swelling, pain and hospital duration compared with conventional cooling. Postoperative trismus and satisfaction with the cooling method was significantly higher in the Hilotherm group compared with conventional cooling. No differences were observed concerning neurological score and outcome. In conclusion, 3D optical scanning is a simple and precise method of quantifying face swelling after orthognathic surgery. Hilotherm significantly reduces swelling and duration of hospital stay compared with conventional cooling. PMID:21411291

  10. Countesthorpe College: an observant study

    ERIC Educational Resources Information Center

    Riley, Ann; Stamatabis, Kathy

    1974-01-01

    Discussed the objectives and the conditions which made possible a new school embodying radical innovations. The results of a observational study at an early stage of the school's development, undertaken by a group of students, are summarised here by two of them, both now teaching in Leicestershire Upper Schools. (Editor/RK)

  11. 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.

  12. 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

  13. 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.

  14. Cultivating Cohort Studies for Observational Translational Research

    PubMed Central

    Ransohoff, David F.

    2013-01-01

    Background “Discovery” research about molecular markers for diagnosis, prognosis, or prediction of response to therapy has frequently produced results that were not reproducible in subsequent studies. What are the reasons, and can observational cohorts be cultivated to provide strong and reliable answers to those questions? Methods Selected examples are used to illustrate: 1) What features of research design provide strength and reliability in observational studies about markers of diagnosis, prognosis, and response to therapy? 2) How can those design features be cultivated in existing observational cohorts, for example within RCTs, other existing observational research studies, or practice settings like HMOs? Results Examples include a study of RNA expression profiles of tumor tissue to predict prognosis of breast cancer; a study of serum proteomics profiles to diagnose ovarian cancer; and a study of stool-based DNA assays to screen for colon cancer. Strengths and weaknesses of observational study design features are discussed, along with lessons about how features that help assure strength might be “cultivated” in the future. Conclusions and Impact By considering these examples and others, it may be possible to develop a process of “cultivating cohorts” - in on-going RCTs, observational cohort studies, and practice settings like HMOs - that have strong features of study design. Such an effort could produce sources of data and specimens to reliably answer questions about the use of molecular markers in diagnosis, prognosis, and response to therapy. PMID:23462919

  15. Observer evaluation of a method for producing simulated mammograms

    NASA Astrophysics Data System (ADS)

    Chinander, Michael R.; Nishikawa, Robert M.; Seifi, Payam

    2007-03-01

    We have developed a method for producing simulated mammograms from high fidelity breast specimen radiographs. The method has the advantage of having access to all the truth information for the lesions. By modeling different parts of a screen-film system, we simulated the output of the system, and compared it to the real mammography images from the same samples. In this work we show how our simulation program produces realistic mammography images and also the observer study that tests how well the observers can distinguish the real and simulated images. Preliminary results from the ROC study show that the observers could not distinguish the two types of images very well.

  16. 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 ...

  17. Assessment of Agreement Between Two Methods with Replicated Observations

    Microsoft Academic Search

    Anuradha Roy

    We study the problem of assessing the agreement between two methods with any number of replicated observations using linear mixed effects (LME) model in a doubly multivariate set-up. This method can also be used in the case of unbalanced designs when number of replications for each patient is unequal, as well as when the number of replications for each patient

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

    Microsoft Academic Search

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

    2004-01-01

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

  19. 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

  20. An observational study found that authors of randomized controlled trials frequently use concealment of randomization and blinding, despite the failure to report these methods

    Microsoft Academic Search

    P. J. Devereaux; Peter T.-L. Choi; Samer El-Dika; Mohit Bhandari; Victor M. Montori; Holger J. Schünemann; Amit X. Garg; Jason W. Busse; Diane Heels-Ansdell; William A. Ghali; Braden J. Manns; Gordon H. Guyatt

    2004-01-01

    Background and objectiveReaders of randomized controlled trials (RCTs) commonly assume that what was not reported did not occur. We undertook an observational study to determine whether concealment of randomization or blinding was used in RCTs that failed to report these bias-reducing strategies.

  1. Evaluation of internal noise methods for Hotelling observer models

    SciTech Connect

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

    2007-08-15

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

  2. Basic Caenorhabditis elegans Methods: Synchronization and Observation

    PubMed Central

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

    2012-01-01

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

  3. 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

  4. Disproportionality Methods for Pharmacovigilance in Longitudinal Observational Databases

    E-print Network

    Madigan, David

    1 Disproportionality Methods for Pharmacovigilance in Longitudinal Observational Databases Ivan-based pharmacovigilance, analytic methods for spontaneous report databases have attracted considerable attention

  5. 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.

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

    PubMed Central

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

    2012-01-01

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

  7. Conformational study of cis-1,4-di-tert-butylcyclohexane by dynamic NMR spectroscopy and computational methods. Observation of chair and twist-boat conformations.

    PubMed

    Gill, Gurvinder; Pawar, Diwakar M; Noe, Eric A

    2005-12-23

    [reaction: see text] Low-temperature 13C NMR spectra of cis-1,4-di-tert-butylcyclohexane (1) showed signals for the twist-boat (1a) and chair (1b) conformations. 13C NMR signals were assigned to specific carbons based on the different populations, different symmetries (time-averaged C(2v) for 1a and time-averaged C(s) for 1b), and calculated chemical shifts (GIAO, HF/6-311+G*). In addition to slow ring inversion and interconversion of the chair and twist-boat conformations, slow rotation of the tert-butyl groups was found. Most of the expected 13C peaks were observed. Free-energy barriers of 6.83 and 6.35 kcal/mol were found for interconversion of 1a (major) and 1b (minor) at -148.1 degrees C. Conformational space was searched with Allinger's MM3 and MM4 programs, and free energies were obtained for several low-energy conformations 1a-c. Calculations were repeated with ab initio methods up to the HF/6-311+G* level. Molecular symmetries, relative free energies, relative enthalpies and entropies, frequencies, and NMR chemical shifts were obtained. A boat conformation (1d; C(2v) symmetry) was generated and optimized as a transition state by ab initio, MM3, and MM4 calculations. PMID:16355992

  8. UFOs: Observations, Studies and Extrapolations

    E-print Network

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

    2012-01-01

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

  9. Clinical Utility of an Observation and Response Chart With Human Factors Design Characteristics and a Track and Trigger System: Study Protocol for a Two-Phase Multisite Multiple-Methods Design

    PubMed Central

    McKinley, Sharon; Perry, Lin; Duffield, Christine; Iedema, Rick; Gallagher, Robyn; Fry, Margaret; Roche, Michael; Allen, Emily

    2014-01-01

    Background Clinical deterioration of adult patients in acute medical-surgical wards continues to occur, despite a range of systems and processes designed to minimize this risk. In Australia, a standardized template for adult observation charts using human factors design principles and decision-support characteristics was developed to improve the detection of and response to abnormal vital signs. Objective To describe the study protocol for the clinical testing of these observation and response charts (ORCs). Methods We propose a two-phase multisite multiple-methods design to test the initial clinical utility of the charts in 10 hospitals of differing types and sizes across state jurisdictions in Australia. Data collection in the first phase includes user surveys, observations and field notes by project officers, handover de-briefs (short interviews with small groups of staff), and an audit of ORC documentation completion compared to the site’s existing observation chart. For the second phase, data will be collected using a retrospective audit of observation documentation from the previous hospital observation chart, prospective audit of observation documentation following implementation of the selected ORC, user focus groups, observational field notes, and patient outcome data from routinely collected organizational data sources. Results Site selection and preparation, project officer training, chart selection and implementation, participant recruitment, and data collection has been completed and the analysis of these results are in progress. Conclusions This detailed description of these study methods and data collection approaches will enable a comprehensive assessment of the clinical utility of these newly developed track and trigger charts and will be useful for clinicians and researchers when planning and implementing similar studies. Potential methodological limitations are also noted. PMID:25116446

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

    PubMed

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

    2014-12-01

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

  11. 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…

  12. 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

  13. 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.

  14. 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)

  15. 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.

  16. The Di Bella Method (DBM) improved survival, objective response and performance status in a retrospective observational clinical study on 23 tumours of the head and neck.

    PubMed

    Di Bella, Giuseppe; Colori, Biagio

    2012-01-01

    In 23 cases of carcinoma of the head and neck, the combined use of Somatostatin and/or its analogue Octreotide, prolactin inhibitors, Melatonin, Retinoids, Vitamin E, Vitamin D3, Vitamin C, Calcium, chondroitin-sulphate, and minimal oral doses of cyclophosphamide (50-100 mg/day) led to a decided increase in survival with respect to the median values reported in the literature for the same tumours and stages, together with an evident improvement in the quality of life, partial or complete objective responses and, in some cases, complete and stable cure with functional recovery. The rationale and the mechanisms of molecular biology of the treatment are discussed, showing that the treatment has a differentiating, apoptotic, antiproliferative, antiangiogenic and antimetastatic effect, and, unlike chemo- and/or radiotherapy, preserves and enhances the trophism and functionality of organs, tissues and immunitary and antitumoral homeostasis. This result, achieved without toxicity, demonstrates the efficacy of this biological multitherapy (Prof. Luigi Di Bella's method or DBM) and is in agreement with the positive results already published on the use of the DBM in various neoplastic diseases. We believe it is of use to report these cases to invite greater interest in the possibilities opened up by this biological multitherapy. PMID:22635078

  17. 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...

  18. 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".

  19. Teaching Social Studies Methods

    NSDL National Science Digital Library

    Darius Kalvaitis

    2006-02-17

    Teaching Social Studies to K-8 students is an engaging and creative process. Children learn best when they are interested and engaged in local and personal history. Connecting historical events to children\\'s lives is a powerful way to develop historical and cultural awareness. In this exercise you will be able to find some national and local resources to help you design and implement Social Studies in your K-8 classrooms. So let\\'s get started! First let\\'s see what kinds of resources are available on the web and other virtual places that are engaging and interesting ...

  20. The Observability Problem in Traffic Models: Algebraic and Topological Methods

    Microsoft Academic Search

    Enrique Castillo; Pilar Jimenez; Jose Maria Menendez; Antonio J. Conejo

    2008-01-01

    This paper deals with the problem of observability of traffic networks, understanding as such the problem of identifying which is the subset of the origin-destination (OD)-pair and link flows that can be calculated based on a subset of observed OD-pair and link flows, and related problems. A modified topological version of an existing algebraic method for solving observability problems is

  1. The high power large aperture radar method for meteor observations

    NASA Astrophysics Data System (ADS)

    Pellinen-Wannberg, Asta

    2001-11-01

    The high power large aperture (HPLA) radar meteor method is presented. It is compared to the classical meteor radar method in terms of working frequency ranges, beam widths and power densities at meteor altitudes to show the basic differences. The classical meteor radars are sensitive to perpendicular meteor trails. The large aperture radars, with higher working frequencies and higher transmitted power, observe the meteoroid-atmosphere interaction at all look-angles. Due to the narrow beams, these radars mainly observe the population of numerous very small sporadic background particles. Almost no shower-related increase in fluxes has been observed in the EISCAT Geminid, Perseid and Leonid observations. Simultaneously with the meteor mode, the HPLA radars can operate in their usual incoherent scatter modes to observe the electron density variations in the background ionosphere. Thus evolution of sporadic E layers, their average ion composition and their relation to meteor activity can be monitored.

  2. Observational study of interacting binary stars

    NASA Astrophysics Data System (ADS)

    Yoon, Tae Seog; Lee, Jeong Ae; Byeon, Jae Gyu; Kim, Kang Min; Kim, Jin Hyung; Yoo, Kye Hwa; Kim, Soo Hyun

    2004-07-01

    We present a progress report on the results obtained from photometric and spectroscopic observations of the interacting binary stars SW Cyg, RR Dra, Y Leo, and SW Lyn in our Galaxy. Analogous studies could be eventually carried out for interacting binaries in the Local Group galaxies. From this study we note the significant H? line profile variations in spectra of SW Cyg taken at two different orbital phases.

  3. 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

  4. A method of clustering observers with different visual characteristics

    Microsoft Academic Search

    Takanaga Niimi; Kuniharu Imai; Mitsuru Ikeda; Hisatoshi Maeda

    2006-01-01

    Evaluation of observer's image perception in medical images is important, and yet has not been performed because it is difficult to quantify visual characteristics. In the present study, we investigated the observer's image perception by clustering a group of 20 observers.Images of a contrast–detail (C–D) phantom, which had cylinders of 10 rows and 10 columns with different diameters and lengths,

  5. What health care managers do: applying Mintzberg's structured observation method.

    PubMed

    Arman, Rebecka; Dellve, Lotta; Wikström, Ewa; Törnström, Linda

    2009-09-01

    Aim The aim of the present study was to explore and describe what characterizes first- and second-line health care managers' use of time. Background Many Swedish health care managers experience difficulties managing their time. Methods Structured and unstructured observations were used. Ten first- and second-line managers in different health care settings were studied in detail from 3.5 and 4 days each. Duration and frequency of different types of work activities were analysed. Results The individual variation was considerable. The managers' days consisted to a large degree of short activities (<9 minutes). On average, nearly half of the managers' time was spent in meetings. Most of the managers' time was spent with subordinates and <1% was spent alone with their superiors. Sixteen per cent of their time was spent on administration and only a small fraction on explicit strategic work. Conclusions The individual variations in time use patterns suggest the possibility of interventions to support changes in time use patterns. Implications for nursing management A reliable description of what managers do paves the way for analyses of what they should do to be effective. PMID:19694915

  6. 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

  7. 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.

  8. 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

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

    PubMed

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

    2014-12-30

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

  10. 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.

  11. 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...

  12. 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.

  13. The Geyser Observation and Study Association

    NSDL National Science Digital Library

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

  14. Advanced Methods of Observing Surface Plasmon Polaritons and Magnons

    NASA Astrophysics Data System (ADS)

    Moghaddam, Abolghasem Mobaraki

    Available from UMI in association with The British Library. Requires signed TDF. The primary objectives of this thesis are the investigation of the theoretical and experimental aspects of the design and construction of advanced techniques for the excitation of surface plasmon-polaritons, surface magneto -plasmon-polaritons and surface magnons. They involve on -line observation of these phenomena and to accomplish these goals, analytical studies of the characteristic behaviour of these phenomena have been undertaken. For excitations of surface plasmon- and surface magneto-plasmon-polaritons the most robust and conventional configuration, namely Prism-Medium-Air, coupled to a novel angle scan (prism spinning) method was employed. The system to be described here can automatically measure the reflectivity of a multilayer system over a range of angles that includes the resonance angle in an Attenuated Total Reflection (ATR) experiment. The computer procedure that controls the system is quite versatile so that it allows any right-angle prism of different angle or refractive index to be utilised. It also provided probes to check for optical alignment within the system. Moreover, it performs the angular scan many times and then averages the results in order to reduce the environmental and other possible sources of noise within the system. The mechanical side of the system is unique and could eventually be adopted as a marketable piece of equipment. It consists of a turntable for holding the prism-sample assembly and a drive motor in conjunction with a servo-potentiometer whose output not only operates the turntable but also sends a signal to a computer to measure accurately its position. The interface unit enables a computer to control automatically an angular scan ATR experiment for measuring the resonance reflectivity spectrum of a multilayer system. The interface unit uses an H-bridge switch formed by four bipolar power transistor and two small signal MOSFETs to convert the digital signal from the computer into a voltage drive for the motor. Surface plasmon-polaritons can become surface magneto-plasmon-polaritons in the presence of an external magnetic field. The metal used for this purpose was a nickel film. Observation of these effects permits a measurement of certain magneto-optical coefficients that are potentially of technological importance. The mechanical side of the surface plasmon (zero field) equipment was redesigned and reconstructed for the excitation and observation of surface magneto-plasmon polaritons. The final part of the thesis is concerned with excitation of magneto-static waves (MSW) and their observation by Brillouin light scattering. Optical set up has been designed that can be used for simultaneous forward and backscattering geometries. This was then used with a multiple pass advanced Fabry-Perot interferometer together with a conventional multichannel analyser to observe MSW. (Abstract shortened by UMI.).

  15. Research Methods for Genetic Studies

    Microsoft Academic Search

    Sadeep Shrestha; Donna K. Arnett

    This chapter introduces the basic concepts of genes and genetic studies to clinicians. Some of the relevant methods and issues\\u000a in genetic epidemiology studies are briefly discussed with an emphasis on single nucleotide polymorphism based association\\u000a studies which are currently the main focus of clinical and translational genetics.\\u000a \\u000a Genetics is the fundamental basis of any organism so understanding of genetics

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Applying an Automatic Image-Processing Method to Synoptic Observations

    NASA Astrophysics Data System (ADS)

    Tlatov, Andrey G.; Vasil'eva, Valeria V.; Makarova, Valentina V.; Otkidychev, Pavel A.

    2014-04-01

    We used an automatic image-processing method to detect solar-activity features observed in white light at the Kislovodsk Solar Station. This technique was applied to automatically or semi-automatically detect sunspots and active regions. The results of this automated recognition were verified with statistical data available from other observatories and revealed a high detection accuracy. We also provide parameters of sunspot areas, of the umbra, and of faculae as observed in Solar Cycle 23 as well as the magnetic flux of these active elements, calculated at the Kislovodsk Solar Station, together with white-light images and magnetograms from the Michaelson Doppler Imager onboard the Solar and Heliospheric Observatory (SOHO/MDI). The ratio of umbral and total sunspot areas during Solar Cycle 23 is ? 0.19. The area of sunspots of the leading polarity was approximately 2.5 times the area of sunspots of the trailing polarity.

  1. 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.

  2. Mortality in people taking selegiline: observational study

    PubMed Central

    Thorogood, Margaret; Armstrong, Ben; Nichols, Tom; Hollowell, Jen

    1998-01-01

    Objective: To evaluate mortality among patients with Parkinson’s disease receiving different treatment. Design: Cohort study based on computerised medical records. Setting: UK General Practice Research Database. Subjects: 12?621 patients aged between 35 and 90 years who had received a prescription for an antiparkinsonian drug, whether or not a diagnosis of Parkinson’s disease had been recorded. Patients prescribed an antipsychotic drug before or at the same time as their first antiparkinsonian drug or before age 35 were excluded to avoid including drug-induced Parkinsonism. Main outcome measure: Death from any cause. Results: 1720 deaths occurred during 14?000 person-years of observation. There was a non-significant 11% (95% confidence interval 0% to 23%) increase in the risk of death associated with taking selegiline either alone or in combination with levodopa. The death rate was higher among younger patients (aged under 80 years) and those with a recorded diagnosis of Parkinson’s disease taking selegiline alone. Conclusions: The results are compatible with a small excess mortality in people taking selegiline and suggest a larger excess in patients under 80 years of age and those with a confirmed diagnosis of Parkinson’s disease taking selegiline without levodopa. Key messages A prematurely stopped randomised trial reported a 50% increase in mortality in subjects treated with selegiline combined with levodopa when compared with subjects treated with levodopa alone. This cohort study based on computerised general practice records examined 14?000 person-years of use of antiparkinsonian drugs There was a non-significant 14% increase in risk of mortality in subjects taking selegiline alone and a non-significant 10% increase for subjects taking selegiline with levodopa This study provides evidence against there being substantial excess mortality associated with use of selegiline PMID:9677215

  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. 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)…

  5. Assessing treatment effects in older breast cancer patients: systematic review of observational research methods.

    PubMed

    de Glas, N A; Kiderlen, M; de Craen, A J M; Hamaker, M E; Portielje, J E A; van de Velde, C J H; Liefers, G J; Bastiaannet, E

    2015-03-01

    Solid evidence of treatment effects in older women with breast cancer is lacking, as they are generally underrepresented in randomized clinical trials on which guideline recommendations are based. An alternative way to study treatment effects in older patients could be to use data from observational studies. However, using appropriate methods in analyzing observational data is a key condition in order to draw valid conclusions, as directly comparing treatments generally results in biased estimates due to confounding by indication. The aim of this systematic review was to investigate the methods that have been used in observational studies that assessed the effects of breast cancer treatment on survival, breast cancer survival and recurrence in older patients (aged 65 years and older). Studies were identified through systematic review of the literature published between January 1st 2009 and December 13th 2013 in the PubMed database and EMBASe. Finally, 31 studies fulfilled the inclusion criteria. Of these, 22 studies directly compared two treatments. Fifteen out of these 22 studies addressed the problem of confounding by indication, while seven studies did not. Nine studies used some form of instrumental variable analysis. In conclusion, the vast majority of observational studies that investigate treatment effects in older breast cancer patients compared treatments directly. These studies are therefore likely to be biased. Observational research will be essential to improve treatment and outcome of older breast cancer patients, but the use of accurate methods is essential to draw valid conclusions from this type of data. PMID:25604065

  6. Indications for thoracic ultrasound in chest medicine: an observational study

    Microsoft Academic Search

    A. R. L. Medford; J. J. Entwisle

    2010-01-01

    IntroductionThoracic ultrasound (TUS) is increasingly used in chest medicine in secondary care. The indications for TUS are well known but less is known about their relative frequency. The purpose of this observational study was to describe the common indications for TUS and their relative frequency and the impact of TUS on management in a consecutive group of patients.Methods80 consecutive inpatients

  7. Observer Rated Sleepiness and Real Road Driving: An Explorative Study

    PubMed Central

    Anund, Anna; Fors, Carina; Hallvig, David; Åkerstedt, Torbjörn; Kecklund, Göran

    2013-01-01

    The aim of the present study was to explore if observer rated sleepiness (ORS) is a feasible method for quantification of driver sleepiness in field studies. Two measures of ORS were used: (1) one for behavioural signs based on facial expression, body gestures and body movements labelled B-ORS, and (2) one based on driving performance e.g. if swerving and other indicators of impaired driving occurs, labelled D-ORS. A limited number of observers sitting in the back of an experimental vehicle on a motorway about 2 hours repeatedly 3 times per day (before lunch, after lunch, at night) observed 24 participant’s sleepiness level with help of the two observer scales. At the same time the participant reported subjective sleepiness (KSS), EOG was recorded (for calculation of blink duration) and several driving measure were taken and synchronized with the reporting. Based on mixed model Anova and correlation analysis the result showed that observer ratings of sleepiness based on drivers’ impaired performance and behavioural signs are sensitive to extend the general pattern of time awake, circadian phase and time of driving. The detailed analysis of the subjective sleepiness and ORS showed weak correspondence on an individual level. Only 16% of the changes in KSS were predicted by the observer. The correlation between the observer ratings based on performance (D-ORS) and behavioural signs (B-ORS) are high (r?=?.588), and the B-ORS shows a moderately strong association (r?=?.360) with blink duration. Both ORS measures show an association (r>0.45) with KSS, whereas the association with driving performance is weak. The results show that the ORS-method detects the expected general variations in sleepy driving in field studies, however, sudden changes in driver sleepiness on a detailed level as 5 minutes is usually not detected; this holds true both when taking into account driving behaviour or driver behavioural signs. PMID:23724094

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

    Shirley, Natalie R; Ramirez Montes, Paula Andrea

    2015-01-01

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

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

    USGS Publications Warehouse

    Koneff, M.D.; Royle, J.A.; 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.

  11. Observability studies of inertial navigation systems

    NASA Technical Reports Server (NTRS)

    Bar-Itzhack, I. Y.; Goshen-Meskin, D.

    1989-01-01

    The present work deals with an undamped three-channel inertial-navigation-system error model. It is shown that it is possible to fully observe, and thus estimate, all the states of the system. This is in contrast to a previous two-channel system, in which it was impossible to fully observe and estimate all the states of the system. The conclusions of the analysis are verified through covariance simulation, which yields identical results.

  12. 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.

  13. Spatial four-alternative forced-choice method is the preferred psychophysical method for naive observers

    Microsoft Academic Search

    Felix A. Wichmann

    2006-01-01

    H. R. Blackwell (1952) investigated the influence of different psychophysical methods and procedures on detection thresholds. He found that the temporal two-interval forced-choice method (2-IFC) combined with feedback, blocked constant stimulus presentation with few different stimulus intensities, and highly trained observers resulted in the ''best'' threshold estimates. This recommendation is in current practice in many psychophysical laboratories and has entered

  14. Observations on the effects of scaling and polishing methods on enamel.

    PubMed

    Fichtel, Tomás; Crha, Michal; Langerová, Erika; Biberauer, Gerhard; Vla ín, Michal

    2008-12-01

    This study compared several techniques of manual and power instrument supragingival scaling and subsequent polishing with different methods. Observations were made to determine if there was an optimal method of enamel surface treatment based on the efficacy of the polishing and damage to the enamel. The maxillary fourth premolar and canine teeth were used as experimental teeth. These teeth were extracted after treatment and immersed in 10% buffered formalin solution for further processing and evaluation using electron microscopy. Our observations indicated that the most effective method for scaling and enamel protection during periodontal treatment was provided by power instrumentation followed by polishing using a soft polishing wheel with pumice paste. PMID:19271410

  15. 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.

  16. Climate Change Studies Using Space Based Observation

    Microsoft Academic Search

    Ranganath R. Navalgund; Raghavendra P. Singh

    Climate change is associated with earth radiation budget that depends upon incoming solar radiation, surface albedo and radiative\\u000a forcing by greenhouse gases. Human activities are contributing to climate change by causing changes in Earth’s atmosphere\\u000a (greenhouse gases, aerosols) and biosphere (deforestation, urbanization, irrigation). Long term and precise measurements from\\u000a calibrated global observation constellation is a vital component in climate system

  17. Parent-child interactions and anxiety disorders: an observational study.

    PubMed

    Hudson, J L; Rapee, R M

    2001-12-01

    Past research has indicated a potential link between anxiety and parenting styles that are characterised by control and rejection. However, few studies have utilised observational methods to support these findings. In the current study, mother-child interactions were observed while the child completed two difficult cognitive tasks. The sample consisted of clinically anxious children (n=43), oppositional defiant children (n=20) and non-clinical children (n=32). After adjusting for the age and sex of the child, mothers of anxious children and mothers of oppositional children displayed greater and more intrusive involvement than mothers of non-clinical children. Mothers of anxious children were also more negative during the interactions than mothers of non-clinical children. The differences between anxious and non-clinical interactions were equivalent across three separate age groups. The results support the relationship between an overinvolved parenting style and anxiety but question the specificity of this relationship. PMID:11758699

  18. Rapid evaluation methods (REM) of health services performance: methodological observations.

    PubMed

    Anker, M; Guidotti, R J; Orzeszyna, S; Sapirie, S A; Thuriaux, M C

    1993-01-01

    The rapid evaluation method (REM) was developed by WHO in order to assess the performance and quality of health care services, identify operational problems, and assist in taking managerial action. It was tested in five developing countries (Botswana, Madagascar, Papua New Guinea, Uganda and Zambia) between 1988 and 1991. REM consists of a set of observation- and survey-based diagnostic activities, carried out mainly in health care facilities. The article describes the various steps of REM, methodological issues such as setting objectives and using an issue-information matrix, preparation of survey instruments, use of computer software (Epi Info), data quality control, fieldwork, and the use of data to produce useful information for decision-makers. REM aims at bringing prompt and relevant information to planners and decision-makers who need it for a specific purpose. In the present examples, REM provided information for preparing a programme proposal for external funding, for establishing baseline data for a situation analysis, and for assessing staff performance after extensive training in order to improve the curriculum. PMID:8440033

  19. 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.

  20. 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.

  1. 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.

  2. Geometric and radiometric performance evaluation methods for marine observation satellite-1 (MOS-1) verification program (MVP)

    NASA Astrophysics Data System (ADS)

    Maeda, Korehiro; Kojima, Masahiro; Azuma, Yoshio

    Marine Observation Satellite-1 (MOS-1) is scheduled for launch in the January and February period of 1987. Main objectives of the MOS-1 are to observe the sea, land and atmosphere by three radiometers (MESSR, VTIR and MSR) and to develop fundamental technologies for earth observation system consisting of space and ground segments. In order to accomplish these objectives NASDA is developing both MOS-1 and ground facilities, and NASDA conducted MOS-1 airborne verification experiment to develop various algorithms which were converted into MOS-1 data processing facility and then used in MOS-1 verification program (MVP). The purposes of the MVP are to evaluate and confirm the distortion correction methods and performance evaluation methods, to evaluate effectiveness of parameters of MOS-1 mission equipment and to reflect the results of the evaluation on the development and operation of the future earth observation system. Concerning radiometric performance, correction methods of deviation of CCD sensitivity for MESSR, calibration methods for VTIR and MSR have been developed and evaluation methods of S/N and dynamic range have been studied. Concerning geometric performance, geometric distortions are classified and distortion correction methods have been developed. Moreover, spatial resolution have been evaluated. In this paper, some of the geometric and radiometric performance evaluation methods are presented and evaluated.

  3. 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…

  4. 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.

  5. 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…

  6. CNODES: the Canadian Network for Observational Drug Effect Studies

    PubMed Central

    Suissa, Samy; Henry, David; Caetano, Patricia; Dormuth, Colin R; Ernst, Pierre; Hemmelgarn, Brenda; LeLorier, Jacques; Levy, Adrian; Martens, Patricia J; Paterson, J Michael; Platt, Robert W; Sketris, Ingrid; Teare, Gary

    2012-01-01

    Abstract Although administrative health care databases have long been used to evaluate adverse drug effects, responses to drug safety signals have been slow and uncoordinated. We describe the establishment of the Canadian Network for Observational Drug Effect Studies (CNODES), a collaborating centre of the Drug Safety and Effectiveness Network (DSEN). CNODES is a distributed network of investigators and linked databases in British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec and Nova Scotia. Principles of operation are as follows: (1) research questions are prioritized by the coordinating office of DSEN; (2) the linked data stay within the provinces; (3)?for each question, a study team formulates a detailed protocol enabling consistent analyses in each province; (4) analyses are “blind” to results obtained elsewhere; (5) protocol deviations are permitted for technical reasons only; (6)?analyses using multivariable methods are lodged centrally with a methods team, which is responsible for combining the results to provide a summary estimate of effect. These procedures are designed to achieve high internal validity of risk estimates and to eliminate the possibility of selective reporting of analyses or outcomes. The value of a coordinated multi-provincial approach is illustrated by projects studying acute renal injury with high-potency statins, community-acquired pneumonia with proton pump inhibitors, and hyperglycemic emergencies with antipsychotic drugs. CNODES is an academically based distributed network of Canadian researchers and data centres with a commitment to rapid and sophisticated analysis of emerging drug safety signals in study populations totalling over 40 million. PMID:23687528

  7. 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...

  8. 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 case–control 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

  9. Optimization of perturb and observe maximum power point tracking method

    Microsoft Academic Search

    Nicola Femia; Giovanni Petrone; Giovanni Spagnuolo; Massimo Vitelli

    2005-01-01

    Maximum power point tracking (MPPT) techniques are used in photovoltaic (PV) systems to maximize the PV array output power by tracking continuously the maximum power point (MPP) which depends on panels temperature and on irradiance conditions. The issue of MPPT has been addressed in different ways in the literature but, especially for low-cost implementations, the perturb and observe (P&O) maximum

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

    PubMed Central

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

    2014-01-01

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

  11. Methodological aspects in the assessment of treatment effects in observational health outcomes studies.

    PubMed

    Haro, Josep Maria; Kontodimas, Stathis; Negrin, Miguel Angel; Ratcliffe, Mark; Suarez, David; Windmeijer, Frank

    2006-01-01

    Prospective observational studies, which provide information on the effectiveness of interventions in natural settings, may complement results from randomised clinical trials in the evaluation of health technologies. However, observational studies are subject to a number of potential methodological weaknesses, mainly selection and observer bias. This paper reviews and applies various methods to control for selection bias in the estimation of treatment effects and proposes novel ways to assess the presence of observer bias. We also address the issues of estimation and inference in a multilevel setting. We describe and compare the use of regression methods, propensity score matching, fixed-effects models incorporating investigator characteristics, and a multilevel, hierarchical model using Bayesian estimation techniques in the control of selection bias. We also propose to assess the existence of observer bias in observational studies by comparing patient- and investigator-reported outcomes. To illustrate these methods, we have used data from the SOHO (Schizophrenia Outpatient Health Outcomes) study, a large, prospective, observational study of health outcomes associated with the treatment of schizophrenia. The methods used to adjust for differences between treatment groups that could cause selection bias yielded comparable results, reinforcing the validity of the findings. Also, the assessment of observer bias did not show that it existed in the SOHO study. Observational studies, when properly conducted and when using adequate statistical methods, can provide valid information on the evaluation of health technologies. PMID:16774289

  12. A fast method for topological observability analysis using a minimum spanning tree technique

    Microsoft Academic Search

    Hiroyuki Mori; Senji Tsuzuki

    1991-01-01

    A new unified method is presented for dealing with the problems of topological observability in power system state estimation: identification of network topological observability, and branches or nodes where pseudo-measurements are necessary to recover the whole network topological observability. The method is based on evaluating the minimum spanning tree in graph theory. The proposed method has been successfully applied to

  13. 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.

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

    Microsoft Academic Search

    Una Macleod; Graham CM Watt

    2008-01-01

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

  15. 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.

  16. Communication behaviours in a hospital setting: an observational study

    PubMed Central

    Coiera, Enrico; Tombs, Vanessa

    1998-01-01

    Objective: An exploratory study to identify patterns of communication behaviour among hospital based healthcare workers. Design: Non-participatory, qualitative observational study. Setting: British district general hospital. Subjects: Eight doctors and two nurses. Results: Communication behaviours resulted in an interruptive workplace, which seemed to contribute to inefficiency in work practice. Medical staff generated twice as many interruptions via telephone and paging systems as they received. Hypothesised causes for this level of interruption include a bias by staff to interruptive communication methods, a tendency to seek information from colleagues in preference to printed materials, and poor provision of information in support of contacting individuals in specific roles. Staff were observed to infer the intention of messages based on insufficient information, and clinical teams demonstrated complex communication patterns, which could lead to inefficiency. Conclusion: The results suggest a number of improvements to processes or technologies. Staff may need instruction in appropriate use of communication facilities. Further, excessive emphasis on information technology may be misguided since much may be gained by supporting information exchange through communication technology. Voicemail and email with acknowledgment, mobile communication, improved support for role based contact, and message screening may be beneficial in the hospital environment. Key messages We observed communication behaviour among 10 hospital based healthcare workers Communication behaviours resulted in an interruptive work place, which seemed to contribute to inefficiency in work practice Medical staff generated twice as many interruptions via telephone and paging systems as they received, and possible causes for this included a bias by staff to interruptive communication methods, a tendency to seek information from colleagues in preference to printed materials, and poor provision of information in support of contacting individuals in specific roles Staff were observed to infer the intention of messages based on insufficient information, and clinical teams showed complex communication patterns, which could lead to inefficiency We conclude that hospital staff may need instruction in appropriate use of communication facilities and that some communication technology—voicemail and email with acknowledgment, cellular telephones for mobile communication, improved support for role based contact, and message screening—may be beneficial PMID:9522794

  17. An evaluation of observational methods for measuring response to classwide intervention.

    PubMed

    Briesch, Amy M; Hemphill, Elizabeth M; Volpe, Robert J; Daniels, Brian

    2015-03-01

    Although there is much research to support the effectiveness of classwide interventions aimed at improving student engagement, there is also a great deal of variability in terms of how response to group-level intervention has been measured. The unfortunate consequence of this procedural variability is that it is difficult to determine whether differences in obtained results across studies are attributable to the way in which behavior was measured or actual intervention effectiveness. The purpose of this study was to comparatively evaluate the most commonly used observational methods for monitoring the effects of classwide interventions in terms of the degree to which obtained data represented actual behavior. The 5 most common sampling methods were identified and evaluated against a criterion generated by averaging across observations conducted on 14 students in one seventh-grade classroom. Results suggested that the best approximation of mean student engagement was obtained by observing a different student during each consecutive 15-s interval whereas observing an entire group of students during each interval underestimated the mean level of behavior within a phase and the degree of behavior change across phases. In contrast, when observations were restricted to the 3 students with the lowest levels of engagement, data revealed greater variability in engagement across baseline sessions and suggested a more notable change in student behavior subsequent to intervention implementation. (PsycINFO Database Record (c) 2015 APA, all rights reserved). PMID:24708285

  18. A Comparison of Three Methods of Measuring Dementia-Specific Quality of Life: Perspectives of Residents, Staff, and Observers

    Microsoft Academic Search

    Perry Edelman; Bradley R. Fulton; Daniel Kuhn; Chih-Hung Chang

    Purpose: This exploratory study compared three methods of assessing dementia specific quality of life, corresponding to the perspectives of residents, staff members, and trained observers. Design and Methods: We collected data on 172 residents with dementia in four special care nursing facilities and three assisted living facilities. Analyses assessed the relationship of each quality-of-life method or perspec- tive to the

  19. Applying Analytical Methods to Study Terrorism

    Microsoft Academic Search

    Todd Sandler; Walter Enders

    2007-01-01

    This paper presents a perspective on the application of theoretical and empirical methods to the study of domestic and transnational terrorism. The use of such methods can lead to informed policy making. On the theoretical side, both choice-theoretic and game-theoretic methods are examined. For empirical applications, the paper focuses on the study of trend, cycles, and forecasting. Additionally, the use

  20. 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...

  1. Methods to study Drosophila immunity.

    PubMed

    Neyen, Claudine; Bretscher, Andrew J; Binggeli, Olivier; Lemaitre, Bruno

    2014-06-15

    Innate immune mechanisms are well conserved throughout evolution, and many theoretical concepts, molecular pathways and gene networks are applicable to invertebrate model organisms as much as vertebrate ones. Drosophila immunity research benefits from an easily manipulated genome, a fantastic international resource of transgenic tools and over a quarter century of accumulated techniques and approaches to study innate immunity. Here we present a short collection of ways to challenge the fruit fly immune system with various pathogens and parasites, as well as read-outs to assess its functions, including cellular and humoral immune responses. Our review covers techniques for assessing the kinetics and efficiency of immune responses quantitatively and qualitatively, such as survival analysis, bacterial persistence, antimicrobial peptide gene expression, phagocytosis and melanisation assays. Finally, we offer a toolkit of Drosophila strains available to the research community for current and future research. PMID:24631888

  2. 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;…

  3. 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 ...

  4. Direct observation method of individual single-stranded DNA molecules using fluorescent replication protein A.

    PubMed

    Oshige, Masahiko; Kawasaki, Shohei; Takano, Hiroki; Yamaguchi, Kouji; Kurita, Hirofumi; Mizuno, Takeshi; Matsuura, Shun-ichi; Mizuno, Akira; Katsura, Shinji

    2011-05-01

    Direct observation studies of single molecules have revealed molecular behaviors usually hidden in the ensemble and time-averaging of bulk experiments. Direct single DNA molecule analysis of DNA metabolism reactions such as DNA replication, repair, and recombination is necessary to fully understand these essential processes. Intercalation of fluorescent dyes such as YOYO-1 and SYTOX Orange has been the standard method for observing single molecules of double-stranded DNA (dsDNA), but effective fluorescent dyes for observing single molecules of single-stranded DNA (ssDNA) have not been found. To facilitate direct single-molecule observations of DNA metabolism reactions, it is necessary to establish methods for discriminating ssDNA and dsDNA. To observe ssDNA directly, we prepared a fusion protein consisting of the 70 kDa DNA-binding domain of replication protein A and enhanced yellow fluorescent protein (RPA-YFP). This fusion protein had ssDNA-binding activity. In our experiments, dsDNA was stained by SYTOX Orange and ssDNA by RPA-YFP, and we succeeded in staining ssDNA and dsDNA by using RPA-YFP and SYTOX Orange simultaneously. PMID:21225324

  5. Rainfall Observed Over Bangladesh 2000-2008: A Comparison of Spatial Interpolation Methods

    NASA Astrophysics Data System (ADS)

    Pervez, M.; Henebry, G. M.

    2010-12-01

    In preparation for a hydrometeorological study of freshwater resources in the greater Ganges-Brahmaputra region, we compared the results of four methods of spatial interpolation applied to point measurements of daily rainfall over Bangladesh during a seven year period (2000-2008). Two univariate (inverse distance weighted and spline-regularized and tension) and two multivariate geostatistical (ordinary kriging and kriging with external drift) methods were used to interpolate daily observations from a network of 221 rain gauges across Bangladesh spanning an area of 143,000 sq km. Elevation and topographic index were used as the covariates in the geostatistical methods. The validity of the interpolated maps was analyzed through cross-validation. The quality of the methods was assessed through the Pearson and Spearman correlations and root mean square error measurements of accuracy in cross-validation. Preliminary results indicated that the univariate methods performed better than the geostatistical methods at daily scales, likely due to the relatively dense sampled point measurements and a weak correlation between the rainfall and covariates at daily scales in this region. Inverse distance weighted produced the better results than the spline. For the days with extreme or high rainfall—spatially and quantitatively—the correlation between observed and interpolated estimates appeared to be high (r2 ~ 0.6 RMSE ~ 10mm), although for low rainfall days the correlations were poor (r2 ~ 0.1 RMSE ~ 3mm). The performance quality of these methods was influenced by the density of the sample point measurements, the quantity of the observed rainfall along with spatial extent, and an appropriate search radius defining the neighboring points. Results indicated that interpolated rainfall estimates at daily scales may introduce uncertainties in the successive hydrometeorological analysis. Interpolations at 5-day, 10-day, 15-day, and monthly time scales are currently under investigation.

  6. 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%…

  7. 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 square–ordered, 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

  8. A non-parametric permutation method for assessing agreement for distance matrix observations.

    PubMed

    Røislien, Jo; Samset, Eigil

    2014-01-30

    Distance matrix data are occurring ever more frequently in medical research, particularly in fields such as genetics, DNA research, and image analysis. We propose a non-parametric permutation method for assessing agreement when the data under study are distance matrices. We apply agglomerative hierarchical clustering and accompanying dendrograms to visualize the internal structure of the matrix observations. The accompanying test is based on random permutations of the elements within individual matrix observations and the corresponding matrix mean of these permutations. We compare the within-matrix element sum of squares (WMESS) for the observed mean against the WMESS for the permutation means. The methodology is exemplified using simulations and real data from magnetic resonance imaging. PMID:23946159

  9. 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 co

  10. Help-Seeking in Elementary Classrooms: An Observational Study.

    ERIC Educational Resources Information Center

    Nelson-Le Gall, Sharon; Glor-Scheib, Susan

    A study was undertaken to explore how elementary school children employ help seeking as a means of problem solving in the classroom. High-, average-, and low-ability students at the first-, third-, and fifth-grade levels were targeted for in-depth observation. A "focal-child" observational procedure was used to gather data on naturally occurring…

  11. Food Worker Hand Washing Practices: An Observation Study

    Microsoft Academic Search

    LAURA R. GREEN; CAROL A. SELMAN; VINCENT RADKE; DANNY RIPLEY; JAMES C. MACK; DAVID W. REIMANN; TAMMI STIGGER; MICHELLE MOTSINGER; LISA BUSHNELL

    2006-01-01

    Improvement of food worker hand washing practices is critical to the reduction of foodborne illness and is dependent upon a clear understanding of current hand washing practices. To that end, this study collected detailed observational data on food worker hand washing practices. Food workers (n 321) were observed preparing food, and data were recorded on specific work activities for which

  12. Attributing Effects to Treatment in Matched Observational Studies

    E-print Network

    Rosenbaum, Paul R.

    Attributing Effects to Treatment in Matched Observational Studies Paul R. Rosenbaum An effect is attributable to treatment if it would not have been observed had the individual been exposed to control instead of the effects of cadmium exposure with a continuous outcome measuring kidney function. Unlike tests of no effect

  13. Case study research: design and methods

    Microsoft Academic Search

    Robert K. Yin; M S Sridhar

    2009-01-01

    Providing a complete portal to the world of case study research, the Fourth Edition of Robert K. Yin's bestselling text Case Study Research offers comprehensive coverage of the design and use of the case study method as a valid research tool. This thoroughly revised text now covers more than 50 case studies (approximately 25\\\\% new), gives fresh attention to quantitative

  14. 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.

  15. 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.

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

    NASA Astrophysics Data System (ADS)

    Hummels, Cameron

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

  17. Application of the time-delay integration method: Survey observations of geosynchronous orbit objects and short-term variability observations

    NASA Astrophysics Data System (ADS)

    Okumura, Shin-ichiro; Yanagisawa, Toshifumi; Nakaya, Hidehiko; Tanaka, Wataru; Nishiyama, Kota; Takahashi, Noritsugu; Yoshikawa, Makoto

    2014-12-01

    "Time-Delay Integration (TDI)" readout technique has been adopted to a mosaic CCD camera equipped with four fully-depleted CCDs. Optical distortion and image deformation due to the TDI operation are discussed. The manner and advantages of the TDI method in survey observations of geosynchronous orbit objects are summarized. We propose a new TDI application method of getting short-term light curves of artificial space objects. This method of detecting a short-term variability can be applied for a variety of objects, ranging from satellites to stars. It can also be used for the light-curve observations of transient objects which might show short-term variability and of which the precise time information is needed.

  18. An Application of Linear Mixed Effects Model to Assess the Agreement Between Two Methods With Replicated Observations

    Microsoft Academic Search

    Anuradha Roy

    2009-01-01

    We study the problem of assessing the agreement between two methods with any number of replicated observations using linear mixed effects (LME) model with Kronecker product covariance structure in a doubly multivariate set-up. This method can also be used in the case of unbalanced designs when number of replications on each patient is unequal, as well as when the number

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

    NASA Astrophysics Data System (ADS)

    Shefer, V. A.

    2011-07-01

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

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

    NASA Astrophysics Data System (ADS)

    Shefer, V. A.

    2010-12-01

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

  1. Observations of Primary Electrons with an Emulsion Chamber by Automatic Scanning Method

    NASA Astrophysics Data System (ADS)

    Sato, Y.; Ohmori, R.; Komori, Y.; Yoshida, K.; Tateyama, N.; Shirai, T.; Yuda, T.; Kobayashi, T.; Yamagami, T.; Saito, Y.; Nishimura, J.

    2003-07-01

    This experiment is designed to observe the accurate electron spectrum beyond 20GeV with an emulsion chamb er, which was exposed to cosmic rays at a balloon altitude. The balloon was launched from Sanriku Balloon Center (ISAS, Japan), in 2001. A new automatic scanning system is intro duced for scanning and analysis of the electron showers in the chamb er. The performance of this system was carefully studied by using calibration plates exposed to electron beams from the accelerator. Scanning and analysis for primary electrons beyond 20 GeV and the future prosp ect of obsevations using this method is reported.

  2. Genetic and Environmental Influences on Observed Personality: Evidence From the German Observational Study of Adult Twins

    Microsoft Academic Search

    Peter Borkenau; Rainer Riemann; Alois Angleitner; Frank M. Spinath

    2001-01-01

    Previous behavior-genetic research on adult personality relied primarily on self-reports or peer reports that may be subject to contrast effects, resulting in biased estimates of genetic and environmental influences. In the German Observational Study of Adult Twins (GOSAT), personality traits of 168 monozygotic (MZ) and 132 dizygotic (DZ) twin pairs were rated on 35 adjective scales, largely markers of the

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

    Microsoft Academic Search

    Tova Rosenbloom

    2006-01-01

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

  4. An Observational Study of Post-Asymptotic Giant Branch Stars

    E-print Network

    An Observational Study of Post-Asymptotic Giant Branch Stars A thesis submitted for the degree model atmosphere analyses of a group of early B-type post- asymptotic giant branch (pAGB) stars opportunity to study stellar evolution almost on a human time-scale. Post-AGB stars have spectral types

  5. Case Studies for Method and Tool Evaluation

    Microsoft Academic Search

    Barbara Kitchenham; Lesley Pickard; Shari Lawrence Pfleeger

    1995-01-01

    Case studies help industry evaluate the benefits of methods and tools and provide a cost-effective way to ensure that process changes provide the desired results. However, unlike formal experiments and surveys, case studies do not have a well-understood theoretical basis. This article provides guidelines for organizing and analyzing case studies so that they produce meaningful results

  6. Atrial septal defect: echocardiographic observations. Studies in 120 patients.

    PubMed

    Radtke, W E; Tajik, A J; Gau, G T; Schattenberg, T T; Giuliani, E R; Tancredi, R G

    1976-03-01

    Previous studies on small numbers of patients have indicated a high incidence of increased right ventricular dimension and abnormal ventricular septal motion in patients with atrial septal defect. However, recent evidence suggests that septal motion may be normal in as many as 46% of patients with atrial septal defect when observed at proper levels. We have analyzed the echocardiograms of 120 patients with sinus venosus or secundum atrial septal defect in an attempt to define sensitivity of the foregoing two echocardiographic abnormalities. Right ventricular dimension index was increased in 98% of patients. When both sides of the ventricular septum were analyzed, abnormal ventricular septal motion was observed in 87% of patients. It is important to observe both right and left septal echoes at all levels. Other measurements and observations were made when possible and are included in the study. PMID:1259258

  7. Transurethral resection syndrome in elderly patients: a retrospective observational study

    PubMed Central

    2014-01-01

    Background Transurethral resection of the prostate (TURP) involves the risk of transurethral resection (TUR) syndrome owing to hyponatremia. Irrigation fluid type, duration of operation, and weight of resected mass have been evaluated as risk factors for TUR syndrome. The purpose of the present study was to identify risk factors related to TUR syndrome in the elderly. Methods After obtaining approval from the Institutional Review Board, data on all elderly males (aged 70 years and older) who underwent TURP under regional anesthesia over a 6-year period at our institution were retrospectively reviewed. TUR syndrome was defined as evidence of a central nervous system disturbance such as nausea, vomiting, restlessness, confusion, or even coma with a circulatory abnormality both intra- and post-operatively. Patients were divided into two groups, positive and negative, for the occurrence of the syndrome. Data such as previous medical history, preoperative and postoperative serum data, weight of resected mass, duration of operation, irrigation fluid drainage technique, anesthetic technique, operative infusion and transfusion volume, and neurological symptoms were collected. Only observational variables with p?studied, 23 had TUR syndrome (23.5%, 95% confidence interval [CI] 14.9–32.0%). Multivariate regression analysis revealed that volume of plasma substitute???500 ml (odds ratio [OR] 14.7, 95% CI 2.9–74.5), continuous irrigation through a suprapubic cystostomy (OR 4.7, 95% CI 1.3–16.7), and weight of resected mass?>?45 g (OR 4.1, 95% CI 1.2–14.7) were associated with significantly increased risks for TUR syndrome (Hosmer-Lemeshow test, p?=?0.94, accuracy 84.7%). Conclusions These results suggest that the use of a plasma substitute and continuous irrigation through a suprapubic cystostomy must be avoided during TURP procedures in the elderly. PMID:24782656

  8. 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.

  9. Carbon nanotubes : a study on assembly methods

    E-print Network

    Quiñones, Lisandro E. (Quiñones Ortiz)

    2008-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  11. Investigating SUMER Coronal Hole Observations: A Robust Method of Raster Reduction

    NASA Astrophysics Data System (ADS)

    Davey, Alisdair R.; McIntosh, Scott W.; Hassler, Donald M.

    2006-07-01

    We present a physically constrained, comprehensive, and robust means of reducing long-duration spectroscopic raster observations made in the important 1530-1555 Å wavelength range by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) instrument on the Solar and Heliospheric Observatory (SOHO). Our method performs corrections in spatial, spectral, and temporal domains following application of the standard SUMER data reduction package to minimize the net Doppler shift of neutral and singly ionized silicon emission lines in the chromosphere. We have applied this method to seven raster observations of the same equatorial coronal hole acquired over a 5 day period, 1999 November 3-8, and to the well-studied observations of 1996 September 21-22. This technique allows us to make physically consistent analyses of multiple SUMER rasters and will aid in future investigations of the solar ``rest'' wavelength of the important Ne VIII 770 Å emission line and, as a result, of the properties of transition region blueshifts-specifically, their correlation to multithermal radiance structure, supergranular network patterns, and the coronal magnetic environment at the perceived lower boundary of solar wind outflow.

  12. Statistical methods for cost-effectiveness analyses that use observational data: a critical appraisal tool and review of current practice.

    PubMed

    Kreif, Noémi; Grieve, Richard; Sadique, M Zia

    2013-04-01

    Many cost-effectiveness analyses (CEAs) use data from observational studies. Statistical methods can only address selection bias if they make plausible assumptions. No quality assessment tool is available for appraising CEAs that use observational studies. We developed a new checklist to assess statistical methods for addressing selection bias in CEAs that use observational data. The checklist criteria were informed by a conceptual review and applied in a systematic review of economic evaluations. Criteria included whether the study assessed the 'no unobserved confounding' assumption, overlap of baseline covariates between the treatment groups and the specification of the regression models. The checklist also considered structural uncertainty from the choice of statistical approach. We found 81 studies that met the inclusion criteria: studies tended to use regression (51%), matching on individual covariates (25%) or matching on the propensity score (22%). Most studies (77%) did not assess the 'no observed confounding' assumption, and few studies (16%) fully considered structural uncertainty from the choice of statistical approach. We conclude that published CEAs do not assess the main assumptions behind statistical methods for addressing selection bias. This checklist can raise awareness about the assumptions behind statistical methods for addressing selection bias and can complement existing method guidelines for CEAs. PMID:22447531

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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 datasets. Globally, there is the IAG GGOS (Global Geodetic Observing System), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, NGOS (Nordic Geodetic Observing System) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss on general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such 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 gravimeter, with the Nordic NKG2005LU land uplift model. 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. It is also important to consider the relation between geodetic observing systems and specific projects like DynaQlim (Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas) or EPOS (European Plate Observing System). The natural aim of observing systems will be to produce data and other products needed by such multidisciplinary projects, but their needs may currently exceed the scope of an observing system. We discuss what requirements the projects pose to observing systems and their development.

  14. Food intake patterns and body mass index in observational studies

    Microsoft Academic Search

    P Togo; M Osler; TIA Sørensen; BL Heitmann

    2001-01-01

    OBJECTIVE: To review studies of patterns of food intake, as assessed by diet index, factor analysis or cluster analysis, and their associations with body mass index or obesity (BMI\\/Ob).DESIGN: Systematic literature review MEDLINE search with crosscheck of references.STUDIES: Thirty observational studies relating food intake patterns to anthropometric information were identified and reviewed. Food intake patterns were defined using a diet

  15. 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.

  16. 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

  17. Correlation studies on surface particle detection methods

    NASA Technical Reports Server (NTRS)

    Peterson, Ronald V.; White, James C.

    1988-01-01

    The accurate determination of dust levels on optical surfaces is necessary to assess sensor system performance. A comparison study was made on several particle measurement methods including those based on direct imaging and light scattering. The effectiveness of removing the particles from the surface prior to determining particle size distributions was also assessed. These studies revealed that some methods, especially those requiring particle removal before analysis, are subject to large systematic errors affecting particle size distributions. Thus, an understanding of the particle measurement methods employed is necessary before any surface cleanliness or obstruction value assignments are accepted as true representations of an optical surface contamination condition.

  18. Fatal poisonings in Oslo: a one-year observational study

    PubMed Central

    2010-01-01

    Background Acute poisonings are common and are treated at different levels of the health care system. Since most fatal poisonings occur outside hospital, these must be included when studying characteristics of such deaths. The pattern of toxic agents differs between fatal and non-fatal poisonings. By including all poisoning episodes, cause-fatality rates can be calculated. Methods Fatal and non-fatal acute poisonings in subjects aged ?16 years in Oslo (428 198 inhabitants) were included consecutively in an observational multi-centre study including the ambulance services, the Oslo Emergency Ward (outpatient clinic), and hospitals, as well as medico-legal autopsies from 1st April 2003 to 31st March 2004. Characteristics of fatal poisonings were examined, and a comparison of toxic agents was made between fatal and non-fatal acute poisoning. Results In Oslo, during the one-year period studied, 103 subjects aged ?16 years died of acute poisoning. The annual mortality rate was 24 per 100 000. The male-female ratio was 2:1, and the mean age was 44 years (range 19-86 years). In 92 cases (89%), death occurred outside hospital. The main toxic agents were opiates or opioids (65% of cases), followed by ethanol (9%), tricyclic anti-depressants (TCAs) (4%), benzodiazepines (4%), and zopiclone (4%). Seventy-one (69%) were evaluated as accidental deaths and 32 (31%) as suicides. In 70% of all cases, and in 34% of suicides, the deceased was classified as drug or alcohol dependent. When compared with the 2981 non-fatal acute poisonings registered during the study period, the case fatality rate was 3% (95% C.I., 0.03-0.04). Methanol, TCAs, and antihistamines had the highest case fatality rates; 33% (95% C.I., 0.008-0.91), 14% (95% C.I., 0.04-0.33), and 10% (95% C.I., 0.02-0.27), respectively. Conclusions Three per cent of all acute poisonings were fatal, and nine out of ten deaths by acute poisonings occurred outside hospital. Two-thirds were evaluated as accidental deaths. Although case fatality rates were highest for methanol, TCAs, and antihistamines, most deaths were caused by opiates or opioids. PMID:20525396

  19. 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.

  20. Clinical features of patients showing Candida hypersensitivity: an observational study

    Microsoft Academic Search

    R Asero; G Bottazzi

    Background: The significance of Candida albicans as an allergen is still unclear. This study aimed at investigating the clinical features of patients monosensitized to Candida. Methods: Thirty-four adult patients monosensitized to the yeast Candida albicans selected from a population of >7000 subjects and referred for suspect respiratory allergy were studied. Ninety subjects monosensitized to different airborne allergens served as controls.

  1. 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)

  2. A (Revised) Survey of Approximate Methods for Solving Partially Observable Markov Decision Processes

    Microsoft Academic Search

    Douglas Aberdeen

    Partially observable Markov decision processes (POMDPs) are inter- esting because they provide a general framework for learning in the pres- ence of multiple forms of uncertainty. We survey methods for learning within the POMDP framework. Because exact methods are intractable we concentrate on approximate methods. We explore two versions of the POMDP training problem: learning when a model of the

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

    E-print Network

    Southworth, John

    2014-01-01

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

  4. Scientific and Ethical Approaches for Observational Exposure Studies

    EPA Science Inventory

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

  5. Lifetime Socioeconomic Position and Mortality: Prospective Observational Study

    Microsoft Academic Search

    George Davey Smith; Carole Hart; David Blane; Charles Gillis; Victor Hawthorne

    1997-01-01

    Objectives: To assess the influence of socioeconomic position over a lifetime on risk factors for cardiovascular disease, on morbidity, and on mortality from various causes. Design: Prospective observational study with 21 years of follow up. Social class was determined as manual or non-manual at three stages of participants' lives: from the social class of their father's job, the social class

  6. 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.

  7. Notes for STA 250, Radford M. Neal, 2000 Observational Studies

    E-print Network

    Neal, Radford M.

    Randomized experiments may be unethical --- eg, for testing whether smoking causes lung cancer. ffl Double variable to the others. In particular, do these other variables have a causal effect? For instance: Does smoking cause cancer? Problem: We can't really answer such questions from an observational study

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

    SciTech Connect

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

    2003-11-01

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

  9. Multimedia measurements and activity patterns in an observational pilot study of nine young children

    Microsoft Academic Search

    Nicolle S Tulve; Peter P Egeghy; Roy C Fortmann; Donald A Whitaker; Marcia G Nishioka; Luke P Naeher; Aaron Hilliard

    2008-01-01

    A pilot observational exposure study was performed to evaluate methods for collecting multimedia measurements (air, dust, food, urine) and activity patterns to assess potential exposures of young children to pesticides in their homes. Nine children (mean age=5 years) and their caregivers participated in this study, performed in the Duval County, Florida, in collaboration with the Centers for Disease Control and

  10. Procalcitonin reflects bacteremia and bacterial load in urosepsis syndrome: a prospective observational study

    Microsoft Academic Search

    Cees van Nieuwkoop; Tobias N Bonten; Jan W van't Wout; Ed J Kuijper; Geert H Groeneveld; Martin J Becker; Ted Koster; G Hanke Wattel-Louis; Nathalie M Delfos; Hans C Ablij; Jaap T van Dissel

    2010-01-01

    INTRODUCTION: Guidelines recommend that two blood cultures be performed in patients with febrile urinary tract infection (UTI), to detect bacteremia and help diagnose urosepsis. The usefulness and cost-effectiveness of this practice have been criticized. This study aimed to evaluate clinical characteristics and the biomarker procalcitonin (PCT) as an aid in predicting bacteremia. METHODS: A prospective observational multicenter cohort study included

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

    E-print Network

    Small, Dylan

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

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

    SciTech Connect

    Pan, Feifei [University of Texas; Peters-lidard, Christa D. [NASA Goddard Space Flight Center; King, Anthony Wayne [ORNL

    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.

  13. 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.

  14. Qualitative Evaluation of Courses Intended for Patients Suffering from Chronic Diseases: New Observation Method for the Continuous Training of the Healthcare Team.

    ERIC Educational Resources Information Center

    Jacquemet, S.; Lacroix, A.; Perrolini, M.; Golay, A.; Assal, J-Ph.

    1998-01-01

    Proposes "analytical observation" as a method of training evaluation for health-care providers. The method, which utilizes observation charts, has been validated through a study that examined the impact of supervision of health-care providers in the domain of therapeutic education of patients. Results show that this method has a definite impact on…

  15. Mosaic CCD method: A new technique for observing dynamics of cometary magnetospheres

    NASA Technical Reports Server (NTRS)

    Saito, T.; Takeuchi, H.; Kozuba, Y.; Okamura, S.; Konno, I.; Hamabe, M.; Aoki, T.; Minami, S.; Isobe, S.

    1992-01-01

    On April 29, 1990, the plasma tail of Comet Austin was observed with a CCD camera on the 105-cm Schmidt telescope at the Kiso Observatory of the University of Tokyo. The area of the CCD used in this observation is only about 1 sq cm. When this CCD is used on the 105-cm Schmidt telescope at the Kiso Observatory, the area corresponds to a narrow square view of 12 ft x 12 ft. By comparison with the photograph of Comet Austin taken by Numazawa (personal communication) on the same night, we see that only a small part of the plasma tail can be photographed at one time with the CCD. However, by shifting the view on the CCD after each exposure, we succeeded in imaging the entire length of the cometary magnetosphere of 1.6 x 10(exp 6) km. This new technique is called 'the mosaic CCD method'. In order to study the dynamics of cometary plasma tails, seven frames of the comet from the head to the tail region were twice imaged with the mosaic CCD method and two sets of images were obtained. Six microstructures, including arcade structures, were identified in both the images. Sketches of the plasma tail including microstructures are included.

  16. Genetic and environmental influences on observed personality: evidence from the German Observational Study of Adult Twins.

    PubMed

    Borkenau, P; Riemann, R; Angleitner, A; Spinath, F M

    2001-04-01

    Previous behavior-genetic research on adult personality relied primarily on self-reports or peer reports that may be subject to contrast effects, resulting in biased estimates of genetic and environmental influences. In the German Observational Study of Adult Twins (GOSAT), personality traits of 168 monozygotic (MZ) and 132 dizygotic (DZ) twin pairs were rated on 35 adjective scales, largely markers of the Big 5. The ratings were provided by 120 judges who never met the twins but observed videotaped behaviors of 1 twin of each pair in 1 of 15 different settings. The aggregated video-based trait ratings were highly reliable, and substantial correlations were obtained between MZ as well as DZ twins. Model-fit analyses suggested about 40% genetic, 25% shared environmental, and 35% nonshared environmental influence. Extraversion was the only trait that seemed not to be influenced by shared environment. PMID:11316228

  17. An Observational Method for Verifying Trends in Urban CO2 Emissions Using Continuous Measurements and High Resolution Meteorology (Invited)

    NASA Astrophysics Data System (ADS)

    Wofsy, S. C.; McKain, K.; Eluszkiewicz, J.; Nehrkorn, T.; Pataki, D. E.; Ehleringer, J.

    2010-12-01

    Nations of the world are attempting to reach international and domestic agreements to limit greenhouse gas emissions. Participants will demonstrate their compliance to such commitments with self-reported emissions estimates based largely on measurements of behavior and generalized conversion factors. Atmospheric observations are the only source of information that will allow reported emissions to be independently and directly verified. Testing of observation-based verification methods is required to establish current capabilities, identify and prioritize areas for improvement, and ensure that policy goals are verifiable. In particular, observations made in major source regions, such as cities, could provide a great deal of information about trends and patterns in anthropogenic emissions with relatively modest investment. This study presents an inaugural effort to estimate carbon dioxide (CO2) emissions from a city using atmospheric measurements. We have developed an observation-modeling framework to track changes in urban emissions, which, in addition to the observations, utilizes an atmospheric transport model and a prior emissions estimates. We have conducted a pilot study of the method using an existing longterm dataset of CO2 observations from Salt Lake City, Utah. Model-simulated CO2 concentrations track diurnal and synoptic patterns in observations reasonably well, although areas for improvement are evident. The modeling framework tends to underestimate observed CO2 enhancements, especially at night, which could be due to underestimated emissions and/or to excessive ventilation in the modeled meteorology. Despite some deficiencies, modeled and observed CO2 values are quantitatively and systematically related and application of a scaling factor to previously estimated emissions improves the match between modeled and observed values. This pilot-study presents a generalized, albeit provisional, method for using urban atmospheric greenhouse gas observations to identify trends and anomalies in urban emissions.

  18. 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

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

    E-print Network

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

    2006-01-01

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

  20. 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)

  1. Study of Vertical Movements of the European Crust Using Tide Gauge and Gnss Observations

    NASA Astrophysics Data System (ADS)

    Tretyak, Kornyliy; Dosyn, Solomiya

    2015-02-01

    This research is devoted to the study of vertical movements of the European crust on the basis of two independent methods, namely tide gauge and GNSS observations results. The description and classification of factors affecting sea level change has been made. The precision with which the movement of the earth's crust according to the results of tide gauge observations can be explored has been calculated . A methodology to identify the duration of tide gauge observations required for studies of vertical movements of the earth 's crust has been presented. Approximation of tide gauge time series with the help of Fourier series has been implemented, the need for long-term observations in certain areas has been explained. The diagram of the velocities of the vertical movements of the European crust on the basis of the tide gauge data and GNSS observations has been built and the anomalous areas where the observations do not coincide have been identified.

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

    PubMed

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

    2014-12-01

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

  3. Foreground separation methods for satellite observations of the cosmic microwave background

    Microsoft Academic Search

    M. P. Hobson; A. W. Jones; A. N. Lasenby; F. R. Bouchet

    1998-01-01

    A maximum entropy method (MEM) is presented for separating the emission due\\u000ato different foreground components from simulated satellite observations of the\\u000acosmic microwave background radiation (CMBR). In particular, the method is\\u000aapplied to simulated observations by the proposed Planck Surveyor satellite.\\u000aThe simulations, performed by Bouchet and Gispert (1998), include emission from\\u000athe CMBR, the kinetic and thermal Sunyaev-Zel'dovich

  4. Rapid alignment method based on local observability analysis for strapdown inertial navigation system

    NASA Astrophysics Data System (ADS)

    Gao, Shesheng; Wei, Wenhui; Zhong, Yongmin; Feng, Zhihua

    2014-02-01

    This paper presents a new method for rapid transfer alignment of strapdown inertial navigation system (SINS) by combining the local observability concept with robust adaptive filtering. The system state and observation models are simplified to analyze the observability of the SINS attitude error. Based on the simplified models, the observability matrix and its condition number are constructed to determine the observability degree of SINS during the process of rapid transfer alignment. On the basis of the local obsersability analysis, a robust adaptive filter is developed to estimate the attitude angle error for SINS rapid transfer alignment. Simulation experiments and comparison analysis have been conducted, demonstrating that the proposed method cannot only effectively measure the local observability of SINS, but it can also enhance the performance of SINS rapid transfer alignment and reduce the alignment time.

  5. Automated Parameter Studies Using a Cartesian Method

    Microsoft Academic Search

    Scott M. Murman; Michael J. Aftosmis; Marian Nemec

    A modular process for performing general parametric studies about an aerodynamic configuration using a Cartesian method is described. A novel part of this process is the automatic handling of general control surfaces deflections based upon simple, user- specified inputs. The article focuses on the use of aerodynamic databases in the design process. Database fly-through is used to develop and analyze

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

    PubMed Central

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

    2013-01-01

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

  7. Meta-analysis of observational epidemiological studies: a review.

    PubMed Central

    Jones, D R

    1992-01-01

    Meta-analyses (integration of findings by quantitative analyses of results of individual studies) are already widely used in the psychological and educational sciences and in the pooling of clinical trial results. Examples of the application of such techniques to the results of observational epidemiological studies are now proliferating. In this paper meta-analysis of the results of observational epidemiological studies is reviewed. Uncritical adoption of techniques used in pooled analyses of clinical trial results may be inappropriate. Some alternative approaches, including meta-regression techniques, are discussed, and illustrated with reference to examples of meta-analyses of studies of breast cancer risk following oral contraceptive use and of patterns of post-bereavement mortality. Although substantial difficulties beset the use of meta-analysis in epidemiology, many of these problems are also implicit in the execution of traditional, narrative reviews. Foremost among these difficulties are those associated with publication bias and with making due allowance for the quality of the studies being combined. Unlike traditional narrative reviews, meta-analyses require explicit statement of the criteria for the review and hence highlight these difficulties. Nonetheless, careful and critical application of appropriate meta-analytical techniques facilitates quantitative exploration of inhomogeneities in, and (where appropriate) synthesis of study results. PMID:1556722

  8. An application of linear mixed effects model to assess the agreement between two methods with replicated observations.

    PubMed

    Roy, Anuradha

    2009-01-01

    We study the problem of assessing the agreement between two methods with any number of replicated observations using linear mixed effects (LME) model with Kronecker product covariance structure in a doubly multivariate set-up. This method can also be used in the case of unbalanced designs when number of replications on each patient is unequal, as well as when the number of replications on each patient by respective methods is unequal. The model is implemented using the MIXED procedure of SAS. We demonstrate our proposed method with three real datasets. PMID:19127473

  9. 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)

  10. Motivation Observations and methods Results & Discussion Minor compounds in Saturn's stratosphere

    E-print Network

    Demoulin, Pascal

    Motivation Observations and methods Results & Discussion Minor compounds in Saturn's stratosphere - 7 October 2009 Sandrine Guerlet Minor compounds in Saturn's stratosphere #12;Motivation Observations of hydrocarbons in Saturn's stratosphere Origin: by-products of CH4 photolysis by solar UV ; Production rates

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

    Microsoft Academic Search

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

    2011-01-01

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

  12. An observational study of adults with Down syndrome eating independently.

    PubMed

    Smith, Christina H; Teo, Yafen; Simpson, Sarah

    2014-02-01

    This study examined the oral feeding in a group of adults with Down syndrome. None of the 23 participants in the study had reported oral feeding difficulties, and all independently ate a full oral diet (food and liquids). Observations were made during the consumption of one meal and one drink. The eating and drinking behaviours observed included eating rate and ability to keep food in the mouth, and these were considered in conjunction with oral and pharyngeal phase skills and difficulties. Coughing, an overt sign of possible aspiration with its attendant risk of upper respiratory tract infection, was seen in 56.5 % of participants. In addition, several of the observed oral feeding behaviours of this group of individuals may be socially unacceptable and therefore likely to compromise quality of life. A number of behaviours with implications for both health and quality of life may be amenable to simple behaviour modification or to changes to the environment. Further study into the causes of these oral feeding difficulties, their implications for social integration, and their potential remediation is required. PMID:23860585

  13. 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.

  14. Observational studies of reconnection in the solar corona

    SciTech Connect

    McKenzie, David E. [Department of Physics, Montana State University, P.O. Box 173840, Bozeman, Montana 59717-3840 (United States)

    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.

  15. 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.

  16. A study of GPS ionospheric scintillations observed at Shenzhen

    NASA Astrophysics Data System (ADS)

    Huang, Linfeng; Wang, Jinsong; Jiang, Yong; Chen, Zhou; Zhao, Kai

    2014-12-01

    Ionospheric scintillation variations are studied using GPS measurements at the low latitude station of Shenzhen (22.59°N, 113.97°E), situated under the northern crest of the equatorial anomaly region, from the Chinese Meridian Project. The results are presented for data collected during the current phase of rising solar activity (low to high solar activity) from December 2010 to April 2014. The results show that GPS scintillation events were largely a nighttime phenomenon during the whole observation period. Scintillation events mainly occurred along the inner edge of the northern crest of the equatorial anomaly in China. The occurrence of scintillations in different sectors of the sky was also investigated, and the results revealed that it is more likely for the scintillations to be observed in the west sector of the sky above Shenzhen. During the present period of study, a total number of 512 total electron content (TEC) depletions and 460 lock loss events were observed. In addition, both of these events are likely to increase during periods of high solar activity, especially because the strong scintillations are often simultaneously accompanied by TEC depletions and lock losses by GPS receivers.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  18. 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

  19. [Radioisotopic methods for studying cerebrospinal fluid shunts].

    PubMed

    Depresseux, J C; Stevenaert, A

    1976-01-01

    The article presents a general and critical review of the radio-isotopic methods for assessing the function of the surgical shunts of cerebrospinal fluid (CSF). The radio-isotope cisternography may indirectly demonstrate the function of the shunt by the postoperative modification of the eventual ventricular reflux and of the permeability of the subarachnoid spaces on the cerebral convexity. The methods of direct ventricular injection of the indicator permit a more direct assessment of the drainage, as based on a scintigraphy, or on the quantitative study of the cephalic radio-activity, or on the demonstration of radio-activityon a target-organ. The direct injection of a highly diffusible indicator in the valve allows a quantitative measurement of the flow of CSF in the shunt and brings morphological arguments for the localization of the eventual occlusion. The technical aspects of the latter method are critically discussed and illustrated by personal results. PMID:796747

  20. Fatal poisonings in Oslo: a one-year observational study

    Microsoft Academic Search

    Mari A Bjornaas; Brita Teige; Knut E Hovda; Oivind Ekeberg; Fridtjof Heyerdahl; Dag Jacobsen

    2010-01-01

    BACKGROUND: Acute poisonings are common and are treated at different levels of the health care system. Since most fatal poisonings occur outside hospital, these must be included when studying characteristics of such deaths. The pattern of toxic agents differs between fatal and non-fatal poisonings. By including all poisoning episodes, cause-fatality rates can be calculated. METHODS: Fatal and non-fatal acute poisonings

  1. 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.

  2. Supplementing Oscat winds with Saral Altika observations for cyclone studies

    NASA Astrophysics Data System (ADS)

    Niharika, K.; Usha Sundari, H. S. V.; Prasad, A. V. V.; Kumari, E. V. S. Sita; Dadhwal, V. K.; Ali, M. M.

    2014-11-01

    Accurate prediction of life cycle of cyclone is very critical to the disaster management practices. Since the cyclones originate over the oceans where in situ observations are limited, we have to resort to the remote sensing techniques. Both optical and microwave sensors help studying the cyclones. While scatterometer provide wind vectors, altimeters can give only wind speed. In this paper we present how altimeter measurements can supplement the scatterometer observations in determining the radius of maximum winds (RMW). Sustained maximum winds, indicator for the intensity of the cyclone, are within the eye wall of a cyclone at a distance of RMW. This parameter is also useful in predicting right time of the storm surge. In this paper we used the wind speed estimations from AltiKa, an altimeter operating at Ka band.

  3. Patient complexity in quality comparisons for glycemic control: An observational study

    Microsoft Academic Search

    Monika M Safford; Michael Brimacombe; Quanwu Zhang; Mangala Rajan; Minge Xie; Wesley Thompson; John Kolassa; Miriam Maney; Leonard Pogach

    2009-01-01

    BACKGROUND: Patient complexity is not incorporated into quality of care comparisons for glycemic control. We developed a method to adjust hemoglobin A1c levels for patient characteristics that reflect complexity, and examined the effect of using adjusted A1c values on quality comparisons. METHODS: This cross-sectional observational study used 1999 national VA (US Department of Veterans Affairs) pharmacy, inpatient and outpatient utilization,

  4. Evaluating causal relationships between urban built environment characteristics and obesity: a methodological review of observational studies.

    PubMed

    Martin, Adam; Ogilvie, David; Suhrcke, Marc

    2014-11-18

    BackgroundExisting reviews identify numerous studies of the relationship between urban built environment characteristics and obesity. These reviews do not generally distinguish between cross-sectional observational studies using single equation analytical techniques and other studies that may support more robust causal inferences. More advanced analytical techniques, including the use of instrumental variables and regression discontinuity designs, can help mitigate biases that arise from differences in observable and unobservable characteristics between intervention and control groups, and may represent a realistic alternative to scarcely-used randomised experiments. This review sought first to identify, and second to compare the results of analyses from, studies using more advanced analytical techniques or study designs.MethodsIn March 2013, studies of the relationship between urban built environment characteristics and obesity were identified that incorporated (i) more advanced analytical techniques specified in recent UK Medical Research Council guidance on evaluating natural experiments, or (ii) other relevant methodological approaches including randomised experiments, structural equation modelling or fixed effects panel data analysis.ResultsTwo randomised experimental studies and twelve observational studies were identified. Within-study comparisons of results, where authors had undertaken at least two analyses using different techniques, indicated that effect sizes were often critically affected by the method employed, and did not support the commonly held view that cross-sectional, single equation analyses systematically overestimate the strength of association.ConclusionsOverall, the use of more advanced methods of analysis does not appear necessarily to undermine the observed strength of association between urban built environment characteristics and obesity when compared to more commonly-used cross-sectional, single equation analyses. Given observed differences in the results of studies using different techniques, further consideration should be given to how evidence gathered from studies using different analytical approaches is appraised, compared and aggregated in evidence synthesis. PMID:25406733

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

    ERIC Educational Resources Information Center

    Chen, Jean

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

  6. 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)

  7. High Performance and Meeting Participation: An Observational Study in Software Design Teams

    Microsoft Academic Search

    Sabine Sonnentag

    2001-01-01

    This study compared high and moderate performers' involvement in cooperation processes. The author used an observational method to examine meeting participation of 60 software professionals from 10 software projects. Analyses showed that high performers participated more in the overall meeting process. In poorly structured meetings, high performers contributed more to process regulation activities, such as meeting management, goal setting, problem

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

    SciTech Connect

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

    2013-03-01

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

  9. ADAPTIVE MATCHING IN RANDOMIZED TRIALS AND OBSERVATIONAL STUDIES

    PubMed Central

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

    2014-01-01

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

  10. 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.

  11. A stepwedge-based method for measuring breast density: observer variability and comparison with human reading

    NASA Astrophysics Data System (ADS)

    Diffey, Jenny; Berks, Michael; Hufton, Alan; Chung, Camilla; Verow, Rosanne; Morrison, Joanna; Wilson, Mary; Boggis, Caroline; Morris, Julie; Maxwell, Anthony; Astley, Susan

    2010-04-01

    Breast density is positively linked to the risk of developing breast cancer. We have developed a semi-automated, stepwedge-based method that has been applied to the mammograms of 1,289 women in the UK breast screening programme to measure breast density by volume and area. 116 images were analysed by three independent operators to assess inter-observer variability; 24 of these were analysed on 10 separate occasions by the same operator to determine intra-observer variability. 168 separate images were analysed using the stepwedge method and by two radiologists who independently estimated percentage breast density by area. There was little intra-observer variability in the stepwedge method (average coefficients of variation 3.49% - 5.73%). There were significant differences in the volumes of glandular tissue obtained by the three operators. This was attributed to variations in the operators' definition of the breast edge. For fatty and dense breasts, there was good correlation between breast density assessed by the stepwedge method and the radiologists. This was also observed between radiologists, despite significant inter-observer variation. Based on analysis of thresholds used in the stepwedge method, radiologists' definition of a dense pixel is one in which the percentage of glandular tissue is between 10 and 20% of the total thickness of tissue.

  12. Patients' views of placement facilities: a participant-observer study.

    PubMed

    Christenfeld, R; Haveliwala, Y A

    1978-03-01

    The authors report a study in which five student nurses from a psychiatric hospital observed and talked with released patients in their new environments-family care homes, adult and boarding homes, nursing and health-related facilities, and their own family homes. Overall, these ex-inpatients seemed responsive to the physical and social features of their new environments. Some of the aspects most often noted as beneficial may have implications for inpatient facilities in terms of architecture, decor, clear differentiation of subunits, and greater exchange of information between inpatient and field staff. PMID:204203

  13. 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.

  14. 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.

  15. Guideline adaptation and implementation planning: a prospective observational study

    PubMed Central

    2013-01-01

    Background Adaptation of high-quality practice guidelines for local use has been advanced as an efficient means to improve acceptability and applicability of evidence-informed care. In a pan-Canadian study, we examined how cancer care groups adapted pre-existing guidelines to their unique context and began implementation planning. Methods Using a mixed-methods, case-study design, five cases were purposefully sampled from self-identified groups and followed as they used a structured method and resources for guideline adaptation. Cases received the ADAPTE Collaboration toolkit, facilitation, methodological and logistical support, resources and assistance as required. Documentary and primary data collection methods captured individual case experience, including monthly summaries of meeting and field notes, email/telephone correspondence, and project records. Site visits, process audits, interviews, and a final evaluation forum with all cases contributed to a comprehensive account of participant experience. Results Study cases took 12 to >24 months to complete guideline adaptation. Although participants appreciated the structure, most found the ADAPTE method complex and lacking practical aspects. They needed assistance establishing individual guideline mandate and infrastructure, articulating health questions, executing search strategies, appraising evidence, and achieving consensus. Facilitation was described as a multi-faceted process, a team effort, and an essential ingredient for guideline adaptation. While front-line care providers implicitly identified implementation issues during adaptation, they identified a need to add an explicit implementation planning component. Conclusions Guideline adaptation is a positive initial step toward evidence-informed care, but adaptation (vs. ‘de novo’ development) did not meet expectations for reducing time or resource commitments. Undertaking adaptation is as much about the process (engagement and capacity building) as it is about the product (adapted guideline). To adequately address local concerns, cases found it necessary to also search and appraise primary studies, resulting in hybrid (adaptation plus de novo) guideline development strategies that required advanced methodological skills. Adaptation was found to be an action element in the knowledge translation continuum that required integration of an implementation perspective. Accordingly, the adaptation methodology and resources were reformulated and substantially augmented to provide practical assistance to groups not supported by a dedicated guideline panel and to provide more implementation planning support. The resulting framework is called CAN-IMPLEMENT. PMID:23656884

  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. 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.

  18. Inverse Abbe-method for observing small refractive index changes in liquids.

    PubMed

    Räty, Jukka; Peiponen, Kai-Erik

    2015-05-01

    This study concerns an optical method for the detection of minuscule refractive index changes in the liquid phase. The proposed method reverses the operation of the traditional Abbe refractometer and thus utilizes the light dispersion properties of materials, i.e. it involves the dependence of the refractive index on light wavelength. In practice, the method includes the detection of light reflection spectra in the visible spectral range. This inverse Abbe method is suitable for liquid quality studies e.g. for monitoring water purity. Tests have shown that the method reveals less than per mil NaCl or ethanol concentrations in water. PMID:25770617

  19. AphasiaBank: Methods for Studying Discourse

    PubMed Central

    MacWhinney, Brian; Fromm, Davida; Forbes, Margaret; Holland, Audrey

    2011-01-01

    Background AphasiaBank is a computerized database of interviews between persons with aphasia (PWAs) and clinicians. By February 2011, the database had grown to include 145 PWAs and 126 controls from 12 sites across the United States. The data and related analysis programs are available free over the web. Aims The overall goal of AphasiaBank is the construction of a system for accumulating and sharing data on language usage by PWAs. To achieve this goal, we have developed a standard elicitation protocol and systematic automatic and manual methods for transcription, coding, and analysis. Methods & Procedures We present sample analyses of transcripts from the retelling of the Cinderella story. These analyses illustrate the application of our methods for the study of phonological, lexical, semantic, morphological, syntactic, temporal, prosodic, gestural, and discourse features. Main Contribution AphasiaBank will allow researchers access to a large, shared database that can facilitate hypothesis testing and increase methodological replicability, precision, and transparency. Conclusions AphasiaBank will provide researchers with an important new tool in the study of aphasia. PMID:22923879

  20. AphasiaBank: Methods for Studying Discourse.

    PubMed

    Macwhinney, Brian; Fromm, Davida; Forbes, Margaret; Holland, Audrey

    2011-01-01

    BACKGROUND: AphasiaBank is a computerized database of interviews between persons with aphasia (PWAs) and clinicians. By February 2011, the database had grown to include 145 PWAs and 126 controls from 12 sites across the United States. The data and related analysis programs are available free over the web. AIMS: The overall goal of AphasiaBank is the construction of a system for accumulating and sharing data on language usage by PWAs. To achieve this goal, we have developed a standard elicitation protocol and systematic automatic and manual methods for transcription, coding, and analysis. METHODS #ENTITYSTARTX00026; PROCEDURES: We present sample analyses of transcripts from the retelling of the Cinderella story. These analyses illustrate the application of our methods for the study of phonological, lexical, semantic, morphological, syntactic, temporal, prosodic, gestural, and discourse features. MAIN CONTRIBUTION: AphasiaBank will allow researchers access to a large, shared database that can facilitate hypothesis testing and increase methodological replicability, precision, and transparency. CONCLUSIONS: AphasiaBank will provide researchers with an important new tool in the study of aphasia. PMID:22923879

  1. Method for obtaining diffraction-limited incoherent images of objects observed through a turbulent atmosphere

    SciTech Connect

    Bel'dyugin, Igor' M [Astrofisika Research and Production Association, Moscow (Russian Federation); Gerasimov, V B; Makarov, N A [Moscow State Institute of Radio Engineering, Electronics and Automatics (Technical University), Moscow (Russian Federation); Efimkov, V F; Zubarev, I G; Mikhailov, S I [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2005-09-30

    A new approach is developed for obtaining diffraction-quality incoherent images of objects observed through a distorting optical medium. In particular, a method is proposed for achieving the diffraction limit for resolving power, including the case of objects observed through a turbulent atmosphere, using comparatively cheap aberrational optical systems (including systems with composite apertures) without using any auxiliary adaptive devices. It is shown that the instrumental function of the atmosphere+telescope system can be reconstructed with the help of the radiation intensity distribution in an auxiliary plane, and then used for obtaining a diffraction-limited image of the observed remote object. Numerical simulation demonstrates the application of this method for identifying various objects by observing them through a turbulent atmosphere. (laser applications and other topics in quantum electronics)

  2. An observational study of central engines in AGN

    NASA Astrophysics Data System (ADS)

    Starling, R. L. C.

    2004-02-01

    This thesis studies the central engines of Active Galactic Nuclei. I investigate the role of accretion discs in AGN by analysis of their multiwavelength observational properties, both in individual sources and in a sample of objects. Particular attention is paid to the interpretation of the big blue bump as thermal emission from an accretion disc. The X-ray properties of contrasting individual galaxies are studied from spectral and temporal data obtained with the XMM satellite. Observational constraints on accretion disc viscosity values are obtained for a subset of the Palomar Green quasar sample. Limits on the viscosity parameter, alpha, assuming a standard Shakura-Sunyaev viscosity prescription, are derived for the sample using the variability in their optical lightcurves. The role of an accretion disc in an unusual Seyfert 1 galaxy, RE J2248-511, is investigated taking a multiwavelength approach. I combine X-ray data from XMM with optical and ultraviolet spectrophotometry and infrared photometry to obtain the spectral energy distribution of an AGN which exhibits both broad optical emission lines (FWHM 3000 km/s) and a soft X-ray excess. I model the observed big blue bump as emission from an accretion disc to explore the physics of a disc within this system and determine the corresponding black hole mass. The results are discussed within the context of normal and narrow-line Seyfert 1 galaxies. XMM data is also used to gain a deeper insight into the X-ray properties of the Seyfert 1 galaxy with LINER (low-ionisation nuclear emission-line region) characteristics, NGC 7213. The broad-band spectral energy distribution of this source gives an insight into accretion in the central regions of LINER galaxies.

  3. 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

    2015-03-01

    Elemental carbon (EC) and organic carbon (OC) represent a substantial portion of particulate matter <2.5??m 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

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

    PubMed Central

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

    2012-01-01

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

  5. 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.

  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. A Tikhonov regularization method to estimate Earth's oblateness variations from global GPS observations

    NASA Astrophysics Data System (ADS)

    Jin, Shuanggen; Zhang, Xinggang

    2014-09-01

    Earth's oblateness is varying due to the redistribution of Earth's fluid mass and the interaction of various components in the Earth system. Nowadays, continuous Global Positioning System (GPS) observations can estimate Earth's oblateness (J2) variations with the least squares method, but are subject to ill-conditioned equations with limited GPS observations and aliasing errors from truncated degrees. In this paper, a Tikhonov regularization method is used to estimate J2 variations from global continuous GPS observations. Results show that the J2 has been better estimated from GPS observations based on a Tikhonov regularization method than the usual least squares method when compared to SLR solutions. Furthermore, the amplitudes and phases of the annual and semi-annual J2 variations are closer to the SLR results with truncated degrees from 2 to 5. Higher truncated degrees will degrade the J2 estimate. Annual J2 variations are best estimated from GPS observations with truncated degree 4 and semi-annual J2 variations are best estimated with truncated degree 2.

  8. Computational and Observational Studies of Interstellar Thioformaldehyde Masers

    NASA Astrophysics Data System (ADS)

    Simpson, Lisa; Hoffman, I. M.

    2013-06-01

    Interstellar spectroscopy of thioformaldehyde (H2CS) holds considerable promise because of the close relationship between the H2CS molecule and the well-studied formaldehyde (H2CO) molecule. In particular, the well-known J(Ka,Kc) = 1(1,0) to 1(1,1) transition of H2CO at 6 cm (4.8 GHz) has an analogous H2CS transition at 1046 MHz. However, the 1046-MHz line of H2CS has never been detected astronomically. We present here a summary of: (1) a computational investigation of H2CS level populations related to known H2CO 6-cm masers, and (2) an observational campaign of four isotopologues of H2CS. Maser emission from H2CO has been observed at 6 cm for which Boland and de Jong (1981) have developed a pump model. We have extended this model to H2CS and we present preliminary calculations for a 1046-MHz maser. We intend to develop a quantitative tool for interpreting H2CS observations toward Galactic and extragalactic locations of H2CO maser emission by constructing a radiative-transfer maser model for H2CS. Thioformaldehyde has been detected in a few Galactic sources via J>1 transitions. However, interpretation of these results has two outstanding problems: the H2CS/H2CO abundances do not agree with known sulfur-to-oxygen ratios nor do the J>1 populations have the expected Boltzmann relationship to the J=1 states. A detection of the 1046-MHz transition of H2CS with J=1 would alleviate many of the ambiguities in the interpretation of existing observational results. We describe our forthcoming experiment to search in a Galactic star-forming region for thermal and nonthermal emission and absorption from four thioformaldehyde isotopologues: H2(12C)(32S), H2(13C)(32S), H2(12C)(34S), and D2(12C)(32S). Taken together, both parts of this research effort will provide valuable and novel constraints on H2CS and H2CO. New observations of H2CS isotopologues will yield new measurements of deuterium-to-hydrogen and sulfur-to-oxygen ratios in star-forming environments. Also, the application of the H2CO maser pump model to H2CS will provide new insights on the rare and enigmatic H2CO masers in the Galaxy. This work is supported by Wittenberg University through the Physics Department and the Student Development Board.

  9. Forced Ignition Study Based on Wavelet Method

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

    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 radical 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 prescribed solution accuracy.

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

    PubMed

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

    2010-01-01

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

  11. 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

  12. 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 (25.29°N, 110.33°E; geomagnetic: 15.04°N, 181.98°E), 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  14. Infliximab treatment in ankylosing spondylitis: an observational study

    PubMed Central

    Nikas, S; Alamanos, Y; Voulgari, P; Pliakou, X; Papadopoulos, C; Drosos, A

    2005-01-01

    Methods: 35 patients with AS with mean (SD) age 42.5 (12.6) years and mean (SD) disease duration 14.5 (8.0) years were studied for 2 years. Patients entering the study had a negative tuberculin skin test, were fully informed about the treatment, and were followed up regularly. Infliximab, 5 mg/kg weight, was given intravenously at weeks 0, 2, 6, and every 8 weeks thereafter. Data concerning infliximab tolerability, adverse events, interval, and drug discontinuation were all recorded. Clinical improvement according to the BASDAI and the Ankylosing Spondylitis Assessment Study group (ASAS) 20%, 40%, and ASAS 5/6 response criteria were recorded. Results: After 1 year, 20 (57%) patients achieved the BASDAI 50% response criteria, 25 (71%) achieved ASAS 20%, 23 (66%) reached ASAS 40%, and 18 (51%) attained ASAS 5/6. After 2 years' treatment, 11 (31%) patients achieved BASDAI 50% response criteria, 14 (40%) ASAS 20%, 11 (31%) ASAS 40%, and 9 (26%) ASAS 5/6. Clinical improvement was associated with an improved BASFI and reduction of CRP. After 2 years' treatment, "infliximab survival" was 89%. Treatment was well tolerated and adverse events were mild; 3 patients discontinued the study. Conclusion: Infliximab was effective, safe, and well tolerated in patients with AS. PMID:15564309

  15. 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.

  16. 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.

  17. Combined observability\\/observation study for nonlinear processes: application to tyre-slip

    Microsoft Academic Search

    C. Noiret; P. Bouron; D. Meizel

    2002-01-01

    This paper proposes to take benefit of the simultaneous use of a state observation technique and of an observability\\/identifiability characterization software to give an integrated answer to the state estimation of nonlinear models. The whole methodology is applicable without any approximation. We motivate and illustrate it on a real system for the estimation of the tyre-slip angle of an automotive.

  18. Instrumenting the City: Developing Methods for Observing and Understanding the Digital Cityscape

    Microsoft Academic Search

    Eamonn O’Neill; Vassilis Kostakos; Tim Kindberg; Ava Fatah Gen. Schieck; Alan Penn; Danae Stanton Fraser; Tim Jones

    2006-01-01

    We approach the design of ubiquitous computing systems in the ur- ban environment as integral to urban design. To understand the city as a system encompassing physical and digital forms and their relationships with people's behaviours, we are developing, applying and refining methods of observing, re- cording, modelling and analysing the city, physically, digitally and socially. We draw on established

  19. A METHOD FOR THE CHARACTERISATION OF SPATIAL STRUCTURES OBSERVED IN CEREBRAL FMRI DATA

    E-print Network

    Adler, Andy

    A METHOD FOR THE CHARACTERISATION OF SPATIAL STRUCTURES OBSERVED IN CEREBRAL FMRI DATA Camille Imaging (fMRI) can detect venous concentration changes of deoxygenated hemoglobin. Cerebral blood flow is locally regulated by pre-capillary arteriolar smooth muscles [1]. Consequently, fMRI images inherit

  20. A Direct Method to Self-Calibrate a Surveillance Camera by Observing a Walking Pedestrian

    Microsoft Academic Search

    Worapan Kusakunniran; Hongdong Li; Jian Zhang

    2009-01-01

    Recent efforts show that it is possible to calibrate a surveillance camera simply from observing a walking hu- man. This procedure can be seen as a special application of the camera self-calibration technique. Several methods have been proposed along this line, but most of them have certain restrictions, such as require the human walking at a constant speed, or require

  1. TV Observations of Meteors in INASAN: Equipment, Methods and First Results

    NASA Astrophysics Data System (ADS)

    Kartashova, Anna P.; Bagrov, A. V.; Leonov, V. A.

    2007-08-01

    For the analysis the risk from particles of meteor streams, we must have proved information about masses and densities of meteors. The prime task is to select minor streams from sporadic meteors. Very few astronomers tried to do it, when others only mark observed meteor “Sporadic” without registering its track. So very few previous observations cannot be used for streams detection, and we had to do it from special observations. As a width of meteoroid stream may be very narrow, the Earth will cross it in few hours and it is necessary to observe meteor events 24 hour a day. This is why we provide meteor monitoring and catch every ray of light in night skies and ask other observers to join our program. The current goal of our investigation is continuous monitoring of meteor events by two ways: from nearby sites (about 20-60 km distance) for triangle observations and simultaneously from some observation sites separated by approximately thousand kilometers for detection of minor streams. The last one will reveal spatial heterogeneity's of strong meteor showers also. Since July 2002 at the Arkhyz Space Tracking Station (North Caucasus) and near Moscow hybrid TV-cameras with CCD (“PatrolCa”) are used for meteor observations. Limiting magnitude of the first camera is about +5 magn in the 52-degrees field under frame rate 25 f/sec, the second camera has limiting magnitude 11,5m in field 18x22 degrees with rate 7,5 f/sec. Since June 2006 four extra PatrolCa begin stereo (basis) TV-observation near Moscow with the aims of determination of individual orbits of observed meteors and their physical densities. Observed by meteor monitoring data show that at least 40% of sporadic meteors may be referred to catalogued weak meteor streams. In this paper we present the method of definition of celestial coordinates of objects in the single frame of the wide-angle system. The method allows definition of celestial coordinates of a meteor at the restrictions of absents of enough stars in the frame during the observations, for example at partially cloudy weather, or when there are few stars in the frame, or at large distortions of a coordinate grid in the frame. These restrictions can forbid direct using of other methods. We objectively registered 38 meteors with wide-angle camera “PatrolCA” during 9 nights from 2002 to 2007 years and 2000 meteors with highly sensitive camera FAVOR during 1000 nights at the same period. The work is supplied by RFBI grants 06-02-08313 and 06-02-16365.

  2. 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

  3. 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

  4. 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

  5. 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.

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

    E-print Network

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

    2015-03-10

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

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

    E-print Network

    Watkins, Joseph C.

    of bacteria? 4 / 16 #12;Observational Studies Randomized Controlled Experiments Principles of Experimental. · The time and money invested can lead to a subconscious effect by the experimenter. Use an appropriate blind

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

    PubMed Central

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

    2013-01-01

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

  9. 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.

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

    PubMed Central

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

    2014-01-01

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

  11. 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

  12. Methods to study chaperone-mediated autophagy.

    PubMed

    Patel, Bindi; Cuervo, Ana Maria

    2015-03-01

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

  13. On the calculation of the topographic wetness index: evaluation of different methods based on field observations

    Microsoft Academic Search

    R. Sørensen; U. Zinko; J. Seibert

    2005-01-01

    The topographic wetness index (TWI, ln(a\\/tanbeta)), which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correlation

  14. On the calculation of the topographic wetness index: evaluation of different methods based on field observations

    Microsoft Academic Search

    R. Sørensen; U. Zinko; J. Seibert

    2006-01-01

    The topographic wetness index (TWI, ln(a\\/tanbeta)), which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correlation

  15. 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.

  16. 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).

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

    PubMed Central

    Liu, Yan

    2014-01-01

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

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

    SciTech Connect

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

    1980-01-01

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

  19. 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

  20. 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.

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

    PubMed Central

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

    2013-01-01

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

  2. Primary care capitation payments in the UK. An observational study

    PubMed Central

    2010-01-01

    Background In 2004 an allocation formula for primary care services was introduced in England and Wales so practices would receive equitable pay. Modifications were made to this formula to enable local health authorities to pay practices. Similar pay formulae were introduced in Scotland and Northern Ireland, but these are unique to the country and therefore could not be included in this study. Objective To examine the extent to which the Global Sum, and modifications to the original formula, determine practice funding. Methods The allocation formula determines basic practice income, the Global Sum. We compared practice Global Sum entitlements using the original and the modified allocation formula calculations. Practices receive an income supplement if Global Sum payments were below historic income in 2004. We examined current overall funding levels to estimate what the effect will be when the income supplements are removed. Results Virtually every Welsh and English practice (97%) received income supplements in 2004. Without the modifications to the formula only 72% of Welsh practices would have needed supplements. No appreciable change would have occurred in England. The formula modifications increased the Global Sum for 99.5% of English practices, while it reduced entitlement for every Welsh practice. In 2008 Welsh practices received approximately £6.15 (9%) less funding per patient per year than an identical English practice. This deficit will increase to 11.2% when the Minimum Practice Income Guarantee is abolished. Conclusions Identical practices in different UK countries do not receive equitable pay. The pay method disadvantages Wales where the population is older and has higher health needs. PMID:20529330

  3. Severe malaria in children in Yemen: two site observational study

    PubMed Central

    Al-Taiar, Abdullah; Jaffar, Shabbar; Assabri, Ali; Al-Habori, Molham; Azazy, Ahmed; Al-Mahdi, Nagiba; Ameen, Khaled; Greenwood, Brian M; Whitty, Christopher J M

    2006-01-01

    Objectives To assess the burden of malaria on health services, describe the clinical presentation of severe malaria in children, and identify factors associated with mortality by means of a prospective observational study. Setting Two public hospitals in Taiz (mountain hinterland) and Hodeidah (coastal plain), Yemen. Participants Children aged 6 months to 10 years. Results Of 12 301 paediatric admissions, 2071 (17%) were for suspected severe malaria. The proportion of such admissions varied according to the season (from 1% to 40%). Falciparum malaria was confirmed in 1332 children; 808 had severe disease as defined by the World Health Organization. Main presentations were respiratory distress (322/808, 40%), severe anaemia (291/800, 37%), and cerebral malaria (60/808, 8%). Twenty two of 26 children who died had a neurological presentation. No deaths occurred in children with severe anaemia but no other signs of severity. In multivariate analysis, a Blantyre coma score ? 2, history of fits, female sex, and hyperlactataemia predicted mortality; severe anaemia, respiratory distress, and hyperparasitaemia were not significant predictors of mortality. Conclusions Severe malaria puts a high burden on health services in Yemen. Although presentation is similar to African series, some important differences exist. Case fatality is higher in girls. PMID:17053235

  4. 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

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

    NASA Astrophysics Data System (ADS)

    Qin, Si-xue

    2015-03-01

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

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

    E-print Network

    Dias, Mafalda; Seery, David

    2015-01-01

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

  7. Increasing Plasmodium falciparum malaria in southwest London: a 25 year observational study

    Microsoft Academic Search

    J P Williams; M Chitre; M Sharland

    2002-01-01

    Aims: To identify changes in the presenting number and species of imported malaria in children in southwest London.Methods: A prospective single observer study over 25 years (1975–99) of all cases of paediatric malaria seen at St George's Hospital.Results: A confirmed diagnosis was made in 249 children (56% boys; 44% girls; median age 8.0 years). Of these, 53% were UK residents

  8. Observation and Study of Proton Aurora by using Scanning Photometer

    NASA Astrophysics Data System (ADS)

    Mochizuki, T.; Ono, T.; Kadokura, A.; Sato, N.

    2009-12-01

    The proton auroras have significant differences from electron auroras in their spectral shape. They show Doppler-shifted and broadened spectra: the spectra have Doppler-shifted (~0.5 nm shorter) peak and both bluewing (~2-4 nm) and redwing (~1.5 nm) extending. Energy spectra of precipitating protons have been estimated from this shape. Recently it is found that the intensity in the extent of the blue wing reflects more effectively by the change of the mean energy of precipitating protons than the shift of peak wavelength [Lanchester et al., 2003]. Another character of the H-beta aurora is that it is diffuse form because a proton becomes hydrogen atom due to a charge-exchange reaction with atmospheric constituent and then possible to move across the magnetic field line. By using a scanning photometer, the movement of the proton auroral belt and change of a spectrum shape associated with the variation of proton source region due to storm and substorm were reported, however, not discussed in detail yet [Deehr and Lummerzheim, 2001]. The purpose of this study is to obtain the detail characteristics of H-beta aurora for understanding of source region of energetic protons in the magnetosphere. For this purpose, a new meridian-scanning photometer (SPM) was installed at Husafell station in Iceland in last summer season and Syowa Station, Antarctica. It will contribute to investigate the distribution of energetic protons and plasma waves which cause the pitch angle scattering in the magnetosphere. The meridian-scanning photometer is able to observe at five wavelengths for H-beta emission. One channel is to measure the background level. By analyzing the data obtained by the SPM, the H-beta spectrum can be estimated by fitting a model function with it. Then it is possible to obtain distribution of precipitating protons in north-south direction. It is also possible to estimate an energy spectrum of precipitating proton, simultaneously. The instrumental parameters of the SPM is defined by the transmission characteristics of the interference filters; they are 485.7 nm (FWHM: 3.0 nm), 484.5 nm (0.6 nm), 485.5 nm (0.6 nm), 486.5 nm (0.6 nm) and 487.5 nm (0.6 nm) for H-beta auroras, and OI 630 nm (0.6 nm), N_2 1PG 670.5 nm (5.0 nm) and OI 844.6 nm (0.6 nm) for electron auroras. We analyzed the event at 2100 UT 23rd June, 2009 observed at Syowa station. This is typical auroral breakup event. And in this event, breakup occurred in FOV of the photometer and expanded to poleward. Then NS aurora appeared and pulsating aurora occurred. We calculated Doppler profile and each parameter is below. The peak intensity is 80 R/nm, wavelength at peak intensity is 486.0 nm, HWHM of bluewing is 1.7 nm and HWHM of redwing is 0.9 nm. These value are within past studies, although the Doppler shift of peak intensity is 0.1 nm and shorter than the average of past studies (0.5 nm). And intensity and Doppler profile of proton aurora changed with eqatorward moving in substorm growth phase. This suggests that the source of precipitating proton moves Earthward and its energy increases, and correspond to the result of Deehr and Lummerzheim, 2001. We are going to report the more detailed result of this event and new events of proton aurora.

  9. 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 (?) 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 ?. We discuss the potential of the procedure for the prediction of emulsion stability in industrial applications. PMID:22215134

  10. A new method for the absolute radiance calibration of zenith sky and MAX-DOAS observations

    NASA Astrophysics Data System (ADS)

    Wagner, Thomas; Remmers, Julia; Shaiganfar, Reza; Beirle, Steffen

    2014-05-01

    Multi AXis (MAX-) DOAS and zenith-DOAS observations measure sun light scattered in the atmosphere. From the recorded spectra information on several trace gases and aerosol extinction can be retrieved. For the trace gas analyses no absolute radiometric calibration is needed, because differential absorption features are analysed. Thus MAX-DOAS and zenith-DOAS instruments are usually not radiometrically calibrated. Here we present a new and simple method for the absolute radiance calibration of MAX-DOAS and zenith-DOAS instruments. It is based on the comparison of the solar zenith angle dependence of the measured and simulated radiances for zenith observations. For this method, measurements with clear sky and rather constant aerosol load are needed. The result of the calibration procedure is a wavelength dependent calibration factor, which transfers the measured radiance units into absolute radiance values with n accuracy of <10%. As a side product, also the spectrally varying aerosol optical depth is determined.

  11. 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.

  12. 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.

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

    Microsoft Academic Search

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

    1997-01-01

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

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

    PubMed Central

    Ortega-García, Juan A; Martin, Marlene; López-Fernández, María T; Fuster-Soler, Jose L; Donat-Colomer, Joaquín; López-Ibor, Blanca; Claudio, Luz; Ferrís-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 grandmother’s 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) 1.1–4.9) – and during the mother’ pregnancies – OR 1.8 (95% CI 1.1–3.3) – were significantly associated with an increased risk of childhood cancer. Conclusions Tobacco smoke exposure during the grandmother’s and mother’s 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

  15. Application of new methods of interpretation of meteor observations at the Institute of Astrophysics of Tajikistan

    NASA Astrophysics Data System (ADS)

    Gritsevich, M. I.; Popelenskaya, N. V.; Stulov, V. P.

    2012-08-01

    New methods of interpretation of meteor observations were developed and published in [1-9]. The interpretation of ground-based observations of meteors and bolides available today in the scientific literature all over the world suffers from serious contradictions. Observers use the so-called photometric approach for determination of extra-atmospheric masses of meteoric bodies. This approach is based on the formula proposed in 1933 [10] and very simple ideas of how to describe the interaction between the atmospheric air and the surface of a meteoric body. These ideas are provisionally suitable to describe the flow around a body in a free molecular regime. Subsequently, the photometric approach was applied to all the meteor events including bolides. The main effort aimed to elaborate the approach included a choice of new formulas for the radiative efficiency.

  16. TECHNIQUES AND METHODS Methods for Developmental Studies of Fear

    E-print Network

    Burgess, Neil

    air-puff conditioning among adults. Blood oxygen level­dependent (BOLD) signal was monitored in seven by pairing of a light with an air puff. Given that prior studies relate air-puff conditioning to risk an air-puff UCS to demonstrate enhanced fear conditioning in children of parents with an anxiety disor

  17. Prevention of Vertical Transmission of Hepatitis B: An Observation Study

    PubMed Central

    Kubo, Ai; Shlager, Lyle; Marks, Amy R.; Lakritz, Dena; Beaumont, Colette; Gabellini, Kim; Corley, Douglas A.

    2014-01-01

    Background For mothers with chronic hepatitis B virus (HBV) infection, the US Centers for Disease Control recommend immunoprophylaxis to decrease perinatal transmission; however, its effectiveness and risk factors for failure have not been well studied in community practice. Objective To investigate the effectiveness of a contemporary immunoprophylaxis protocol. Design Observational study. Setting HBV perinatal immunoprophylaxis program within Kaiser Permanente Northern California, an integrated health services delivery organization. Patients 4,446 infants born to 3,253 HBV positive mothers, between 1997-2010. Measurements Compliance with immunoprophylaxis, follow-up testing rates, maternal risk factors for HBV transmission and transmission rates. Results The infant infection rate was 0.75 per 100 births for 1997-2010 (Poisson 95% confidence interval (CI): 0.48-1.10)]. Rates were 3.37 per 100 (95% CI 2.08-5.14) for e-antigen positive mothers; and 0.04 (95% CI 0.001-0.24) for e-antigen negative mothers. Among mothers with viral load testing, the lowest level associated with transmission was 63,200,000 IU/ml. Infection rates per 100 were 3.61 (95% CI 0.75-10.56) among the 83 births to mothers with viral loads ?50,000,000 IU/mL and 0.00 among the 831 births to mothers with viral loads <50,000,000 IU/mL, regardless of e-antigen status. Limitations Testing for HBV immunity and infection was somewhat less complete in earlier years. Viral load testing was only consistently available starting in 2007. Conclusion Pre-natal HBV screening followed by post-natal prophylaxis is highly effective in preventing vertical transmission of HBV. A negative e-antigen status or a viral load of <50,000,000 IU/mL (90.9% of women tested) identifies women at extremely low risk of transmission after immunoprophylaxis who are unlikely to benefit from further interventions. Primary Funding Source Kaiser Permanente Community Benefit Grant (CN-09LShla-01-H); National Institute of Health (K07CA166143-01A1 and KL2TR000143). PMID:24862434

  18. Applications of propensity score methods in observational comparative effectiveness and safety research: where have we come and where should we go?

    PubMed

    Borah, Bijan J; Moriarty, James P; Crown, William H; Doshi, Jalpa A

    2014-01-01

    Propensity score (PS) methods have proliferated in recent years in observational studies in general and in observational comparative effectiveness research (CER) in particular. PS methods are an important set of tools for estimating treatment effects in observational studies, enabling adjustment for measured confounders in an easy-to-understand and transparent way. This article demonstrates how PS methods have been used to address specific CER questions from 2001 through to 2012 by identifying six impactful studies from this period. This article also discusses areas for improvement, including data infrastructure, and a unified set of guidelines in terms of PS implementation and reporting, which will boost confidence in evidence generated through observational CER using PS methods. PMID:24266593

  19. Plasma sheet fast flows observations during substorm: a case study

    NASA Astrophysics Data System (ADS)

    Borodkova, N. L.; Yahnin, A. G.; Sauvaud, J.-A.; Lutsenko, V. N.

    2003-04-01

    INTERBALL-1 observations of a substorm development in the mid-tail are compared with the auroral dynamics and with the observations performed by adjacent spacecraft. It was shown that in the mid plasma sheet, the flows were directed tailward when the auroral bulge developed equatorward of the spacecraft ionospheric footprint. When active auroras moved poleward of the INTERBALL-1 projection, earthward bursty bulk flows (BBFs) were observed. This confirms the concept that flow reversal region is the source of auroras forming the poleward edge of the auroral bulge. The comparison of the fast flows directions obtained by nearby satellites in the plasma sheet during the substorm was done.

  20. Photometric Observation and Apsidal motion Study of V1143 Cyg

    E-print Network

    A. Dariush; N. Riazi; A. Afroozeh

    2004-11-30

    Photometric observations of the eccentric eclipsing binary V1143 Cygni were performed during the August-September 2000 and July 2002, in B and V bands of the Johnson system. The analysis on both light curves was done separately using the 1998 version of Wilson's LC code. In order to find a new observed rate of apsidal motion, we followed the procedure described by Guinan and Maloney (1985). A new observed rate of apsidal motion of 3.72 degrees/100yr was computed which is close to the one reported earlier by Khaliullin (1983), Gimenez and Margrave (1985), and Burns et al.(1996).

  1. 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.

  2. Missing Data in Clinical Studies: Issues and Methods

    PubMed Central

    Ibrahim, Joseph G.; Chu, Haitao; Chen, Ming-Hui

    2012-01-01

    Missing data are a prevailing problem in any type of data analyses. A participant variable is considered missing if the value of the variable (outcome or covariate) for the participant is not observed. In this article, various issues in analyzing studies with missing data are discussed. Particularly, we focus on missing response and/or covariate data for studies with discrete, continuous, or time-to-event end points in which generalized linear models, models for longitudinal data such as generalized linear mixed effects models, or Cox regression models are used. We discuss various classifications of missing data that may arise in a study and demonstrate in several situations that the commonly used method of throwing out all participants with any missing data may lead to incorrect results and conclusions. The methods described are applied to data from an Eastern Cooperative Oncology Group phase II clinical trial of liver cancer and a phase III clinical trial of advanced non–small-cell lung cancer. Although the main area of application discussed here is cancer, the issues and methods we discuss apply to any type of study. PMID:22649133

  3. A Global Logrank Test for Adaptive Treatment Strategies Based on Observational Studies

    PubMed Central

    Li, Zhiguo; Valenstein, Marcia; Pfeiffer, Paul; Ganoczy, Dara

    2013-01-01

    In studying adaptive treatment strategies, a natural question that is of paramount interest is whether there is any significant difference among all possible treatment strategies. When the outcome variable of interest is time-to-event, we propose an inverse probability weighted logrank test for testing the equivalence of a fixed set of pre-specified adaptive treatment strategies based on data from an observational study. The weights take into account both the possible selection bias in an observational study and the fact that the same subject may be consistent with more than one treatment strategy. The asymptotic distribution of the weighted logrank statistic under the null hypothesis is obtained. We show that, in an observational study where the treatment selection probabilities need to be estimated, the estimation of these probabilities does not have an effect on the asymptotic distribution of the weighted logrank statistic, as long as the estimation of the parameters in the models for these probabilities is n-consistent. Finite sample performance of the test is assessed via a simulation study. We also show in the simulation that the test can be pretty robust to misspecification of the models for the probabilities of treatment selection. The method is applied to analyze data on antidepressant adherence time from an observational database maintained at the Department of Veterans Affairs’ Serious Mental Illness Treatment Research and Evaluation Center. PMID:24108518

  4. Live-cell studies with the Axio Observer

    Microsoft Academic Search

    Eugen Wehner

    2006-01-01

    The Axio Observer inverted research microscope from Carl Zeiss, available with three different stand formats and a variety of other optional features, gives users a flexible and powerful tool for performing fluorescence microscopy.

  5. Photometric Observation And Period Study of GO Cygni

    E-print Network

    S. M. Zabihinpoor; A. Dariush; N. Riazi

    2005-08-07

    Photometric observations of GO Cyg were performed during the July-October 2002, in B and V bands of Johnson system. Based on Wilson's model, the light curve analysis were carried out to find the photometric elements of the system. The O-C diagram which is based on new observed times of minima suggests a negative rate of period variation (dP/dt<0) for the system.

  6. 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 (?=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

  7. 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.

  8. 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…

  9. Rainfall Observed Over Bangladesh 2000-2008: A Comparison of Spatial Interpolation Methods

    Microsoft Academic Search

    M. Pervez; G. M. Henebry

    2010-01-01

    In preparation for a hydrometeorological study of freshwater resources in the greater Ganges-Brahmaputra region, we compared the results of four methods of spatial interpolation applied to point measurements of daily rainfall over Bangladesh during a seven year period (2000-2008). Two univariate (inverse distance weighted and spline-regularized and tension) and two multivariate geostatistical (ordinary kriging and kriging with external drift) methods

  10. 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.

  11. Analysis of effects of active sources on observed phase velocity based on the thin layer method

    NASA Astrophysics Data System (ADS)

    Chai, Hua-You; Phoon, Kok-Kwang; Wei, Chang-Fu; Lu, Ying-Fa

    2011-01-01

    In the wave field induced by active sources, the observed phase velocity of surface waves is influenced by both mode incompatibility (i.e. non-planar spread of surface waves is idealized as plane waves) and body waves. Effects of sources are usually investigated based on numerical simulations and physical models. Several methods have been proposed to mitigate the effects. In application, however, these methods may also have difficulties since the energy of the body waves depends on soil stratification and parameters. There are multiple modes of surface waves in layered media, among which the higher modes dominate the wave field for soils with the irregular shear velocity profiles. Considering the mode incompatibility and the higher modes, we derive analytical expressions for the effective phase velocity of the surface waves based on the thin layer stiffness method, and investigate the effects of the body waves on the observed phase velocity through the phase analysis of the vibrations of both the surface waves and the body waves. The results indicate that the effective phase velocity of the surface waves in layered media varies with the frequency and the spread distance, and is underestimated compared to that of the plane surface waves in the spread range less than about one wavelength. The oscillations that appeared in the observed phase velocity are due to the involvement of the body waves. The mode incompatibility can be ignored in the range beyond one wavelength, while the influence range of the body waves is far beyond one wavelength. The body waves have a significant influence on the observed phase velocity of the surface waves in soils with a soft layer trapped between the first and the second layers because of strong reflections.

  12. 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.

  13. 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

  14. 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...

  15. Manchester triage system in paediatric emergency care: prospective observational study

    PubMed Central

    2008-01-01

    Objective To validate use of the Manchester triage system in paediatric emergency care. Design Prospective observational study. Setting Emergency departments of a university hospital and a teaching hospital in the Netherlands, 2006-7. Participants 17?600 children (aged <16) visiting an emergency department over 13 months (university hospital) and seven months (teaching hospital). Intervention Nurses triaged 16?735/17?600 patients (95%) using a computerised Manchester triage system, which calculated urgency levels from the selection of discriminators embedded in flowcharts for presenting problems. Nurses over-ruled the urgency level in 1714 (10%) children, who were excluded from analysis. Complete data for the reference standard were unavailable in 1467 (9%) children leaving 13?554 patients for analysis. Main outcome measures Urgency according to the Manchester triage system compared with a predefined and independently assessed reference standard for five urgency levels. This reference standard was based on a combination of vital signs at presentation, potentially life threatening conditions, diagnostic resources, therapeutic interventions, and follow-up. Sensitivity, specificity, and likelihood ratios for high urgency (immediate and very urgent) and 95% confidence intervals for subgroups based on age, use of flowcharts, and discriminators. Results The Manchester urgency level agreed with the reference standard in 4582 of 13?554 (34%) children; 7311 (54%) were over-triaged and 1661 (12%) under-triaged. The likelihood ratio was 3.0 (95% confidence interval 2.8 to 3.2) for high urgency and 0.5 (0.4 to 0.5) for low urgency; though the likelihood ratios were lower for those presenting with a medical problem (2.3 (2.2 to 2.5) v 12.0 (7.8 to 18.0) for trauma) and in younger children (2.4 (1.9 to 2.9) at 0-3 months v 5.4 (4.5 to 6.5) at 8-16 years). Conclusions The Manchester triage system has moderate validity in paediatric emergency care. It errs on the safe side, with much more over-triage than under-triage compared with an independent reference standard for urgency. Triage of patients with a medical problem or in younger children is particularly difficult. PMID:18809587

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

    PubMed Central

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

    2014-01-01

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

  17. Estimation and calibration of observation impact signals using the Lanczos method in NOAA/NCEP data assimilation system

    NASA Astrophysics Data System (ADS)

    Wei, M.; De Pondeca, M. S. F. V.; Toth, Z.; Parrish, D.

    2012-09-01

    Despite the tremendous progress that has been made in data assimilation (DA) methodology, observing systems that reduce observation errors, and model improvements that reduce background errors, the analyses produced by the best available DA systems are still different from the truth. Analysis error and error covariance are important since they describe the accuracy of the analyses, and are directly related to the future forecast errors, i.e., the forecast quality. In addition, analysis error covariance is critically important in building an efficient ensemble forecast system (EFS). Estimating analysis error covariance in an ensemble-based Kalman filter DA is straightforward, but it is challenging in variational DA systems, which have been in operation at most NWP (Numerical Weather Prediction) centers. In this study, we use the Lanczos method in the NCEP (the National Centers for Environmental Prediction) Gridpoint Statistical Interpolation (GSI) DA system to look into other important aspects and properties of this method that were not exploited before. We apply this method to estimate the observation impact signals (OIS), which are directly related to the analysis error variances. It is found that the smallest eigenvalue of the transformed Hessian matrix converges to one as the number of minimization iterations increases. When more observations are assimilated, the convergence becomes slower and more eigenvectors are needed to retrieve the observation impacts. It is also found that the OIS over data-rich regions can be represented by the eigenvectors with dominant eigenvalues. Since only a limited number of eigenvectors can be computed due to computational expense, the OIS is severely underestimated, and the analysis error variance is consequently overestimated. It is found that the mean OIS values for temperature and wind components at typical model levels are increased by about 1.5 times when the number of eigenvectors is doubled. We have proposed four different calibration schemes to compensate for the missing trailing eigenvectors. Results show that the method with calibration for a small number of eigenvectors cannot pick up the observation impacts over the regions with fewer observations as well as a benchmark with a large number of eigenvectors, but proper calibrations do enhance and improve the impact signals over regions with more data. When compared with the observation locations, the method generally captures the OIS over regions with more observation data, including satellite data over the southern oceans. Over the tropics, some observation impacts may be missed due to the smaller background errors specified in the GSI, which is not related to the method. It is found that a large number of eigenvectors are needed to retrieve impact signals that resemble the banded structures from satellite observations, particularly over the tropics. Another benefit from the Lanczos method is that the dominant eigenvectors can be used in preconditioning the conjugate gradient algorithm in the GSI to speed up the convergence.

  18. In-situ observation and relocation method of nanomaterial samples based on microscope systems.

    PubMed

    Zeng, Leyong; Wu, Aiguo; Wang, Yazhuo; Pu, Shiliu; Ding, Jiandong

    2012-02-01

    Taking poly(lactic acid) microbubbles and purple membranes as examples, a general in situ observation and relocation method of nanomaterial samples based on microscope systems was reported. First, a four-grade coordinate with different precisions was marked around a substrate by UV lithography. Second, using optical microscope and scanning probe microscope, special positions of poly(lactic acid) microbubbles and purple membranes were observed, respectively. Third, the four-grade coordinate value corresponded to the special sample position, and the distance between the special position and coordinate edge were recorded, respectively. Finally, the special position can be easily found again, or the sample in the special position can be manipulated and secondary processed based on the recorded coordinate value and distance, after the sample was removed and then was reset on the sample stage of microscope. The in situ observation and relocation method can be applied in different microscope systems and different sample substrates, and will have potential applications in the manipulation and the secondary process of micro- and nano-devices. PMID:21761495

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

    PubMed Central

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

    1997-01-01

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

  20. 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...

  1. 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.

  2. Three-dimensional domain observations of magnetite and titanomagnetites using the dried colloid SEM method

    NASA Astrophysics Data System (ADS)

    Soffel, H. C.; Aumüller, C.; Hoffmann, V.; Appel, E.

    Dried colloid scanning electron microscopy (SEM) has been applied for the study of Bitter patterns on unpolished and uneven surfaces of microcrystals of natural ferrites (hydrothermally grown magnetite, synthetic TM70 and TM50 removed from a basaltic rock matrix). By the simultaneous observation of domain walls on crystal surfaces of different orientation with high resolution, information is obtained on the volume domain structure underneath. The observation confirms the presence of lamellae-shaped volume domains associated with closure domains on the surface for the reduction of the magnetic stray field energy.

  3. Imaging method for changes in venous dynamics: a preliminary study.

    PubMed

    Lee, Yeong-Bae; Seo, Yeong-Bae; Park, Chan-A; Kang, Chang-Ki

    2015-04-15

    The present study proposes a novel functional magnetic resonance venography (fMRV) method to examine changes in venous dynamics that are difficult to detect with commonly used MRV methods such as susceptibility-weighted imaging (SWI). We used a fast gradient echo imaging sequence, known as a time-resolved angiography with interleaved stochastic trajectories, at 7T MRI; it achieves a high temporal resolution of 3?s, which enables detection of dynamic changes in blood oxygenation within the cerebral veins. Twelve healthy individuals participated in this functional imaging study. SWI was also performed using optimized parameters for comparison with fMRV. We measured the average signal change from representative veins in the visual cortex between resting and stimulation conditions. fMRV showed signal changes between the resting and the stimulation conditions in venous vessels more clearly than SWI. Dynamic changes in venous vessel oxygenation signals were observed in the 3?s measurement windows, and these changes showed an ?3?s delay at the onset and offset of stimulation. The average increase in the venous signal intensity was 6.86±0.82% (mean±SEM) during stimulation relative to the resting condition. This study shows that fMRV can directly visualize individual venous vessel blood oxygenation changes during visual stimulation, suggesting that it could be a useful method to investigate venous dynamics induced by visual stimulation. PMID:25714427

  4. 78 FR 32406 - Submission for OMB Review; 30-Day Comment Request: Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-30

    ...Review; 30-Day Comment Request: Women's Health Initiative Observational Study...Eason Ludlam, Project Officer, Women's Health Initiative Program Office, 6701...writing. Proposed Collection: Women's Health Initiative Observational...

  5. 78 FR 24220 - Submission for OMB Review; 30-Day Comment Request: Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ...Review; 30-Day Comment Request: Women's Health Initiative Observational Study...Eason Ludlam, Project Officer, Women's Health Initiative Program Office, 6701...writing. Proposed Collection: Women's Health Initiative Observational...

  6. 75 FR 17411 - Submission for OMB Review; Comment Request; Women's Health Initiative Observational Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

    ...OMB Review; Comment Request; Women's Health Initiative Observational Study...Proposed Collection: Title: Women's Health Initiative (WHI) Observational...Eason Ludlam, Project Officer, Women's Health Initiative Program Office,...

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  9. 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

  10. A helicopter observation platform for atmospheric boundary layer studies

    Microsoft Academic Search

    Heidi Eichinger Holder

    2009-01-01

    Spatial variability of the Earth's surface has a considerable impact on the atmosphere at all scales and understanding the mechanisms involved in land-atmosphere interactions is hindered by the scarcity of appropriate observations. A measurement gap exists between traditional point sensors and large aircraft and satellite-based sensors in collecting measurements of atmospheric quantities. Point sensors are capable of making long time

  11. 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,…

  12. Changes in smoking behaviours following a smokefree legislation in parks and on beaches: an observational study

    PubMed Central

    Okoli, Chizimuzo; Johnson, Andrew; Pederson, Ann; Adkins, Sarah; Rice, Wendy

    2013-01-01

    Objective To examine the effect of an outdoor smokefree law in parks and on beaches on observed smoking in selected venues. Methods The study involved repeated observations in selected parks and beaches in Vancouver, British Columbia, Canada. The main outcome measure was changes in observed smoking rates in selected venues from prelaw to 12 months postlaw. Results No venue was 100% smokefree at the 12-month postlaw observation time point. There was a significant decrease in observed smoking rates in all venues from prelaw to 12-month postlaw (prelaw mean smoking rate=20.5 vs 12-month mean smoking rate=4.7, p=0.04). In stratified analysis by venue, the differences between the prelaw and 12-month smoking rates decreased significantly in parks (prelaw mean smoking rate=37.1 vs 12-month mean smoking rate=6.5, p=0.01) but not in beaches (prelaw mean smoking rate=2.9 vs 12-month mean smoking rate=1.0, p=0.1). Conclusions Smokefree policies in outdoor recreational venues have the potential to decrease smoking in these venues. The effectiveness of such policies may differ by the type and usage of the venue; for instance, compliance may be better in venues that are used more often and have enforcement. Future studies may further explore factors that limit and foster the enforcement of such policies in parks and beaches. PMID:23794560

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

    PubMed Central

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

    2013-01-01

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

  14. SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF LIPOXIDASE ACTIVITY: OBSERVATIONS ON UNSATURATED-FAT OXIDASE

    Microsoft Academic Search

    Surrey

    1962-01-01

    BS>An improved spectrophotometric method for the determination of ; lipoxidase activity was developed and applied in studies of the purified enzyme ; and crude enzyme preparations from leguminous and other seeds, with linoleic acid ; as the substrate. The optimum pH was found to be crude lipoxidases from graham ; flour, soy beam meal, and hydrated mung beans, respectively. Hydrated

  15. 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.

  16. 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.

  17. Taguchi methods in electronics: A case study

    NASA Astrophysics Data System (ADS)

    Kissel, R.

    1992-05-01

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

  18. Observational and theoretical studies of the nova outburst

    SciTech Connect

    Starrfield, S.; Vanlandingham, K.; Schwarz, G. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics and Astronomy] [and others

    1998-04-01

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

  19. Observational and numerical study of Atlantic tropical instability waves

    E-print Network

    Wu, Qiaoyan

    2009-06-02

    Regression maps for SST and wind velocity in the period of JJA . . . . . . 41 15 Time series of SST anomalies in JJA 1998 at the reference point (15?W, 2?N). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 16 Regression maps for SST.... . . . . . 60 27 Regression maps for surface wind convergence, column-integrated water vapor and rain from observations. . . . . . . . . . . . . . . . . . . 62 28 Regression maps for surface wind convergence, mixing ratio and rain from model...

  20. Geophysical observations around the Imjin River Belt in the middle Korean Peninsula by seismological and electromagnetic methods

    NASA Astrophysics Data System (ADS)

    Yang, J.; Lim, C.; Choi, H.

    2013-12-01

    Imjin River Belt (IRB), located in the middle of the Korean Peninsula, has been one of long-standing geological issues because it is a very important tectonic link to understand a tectonic evolution of north-eastern Asia including China, Korea and Japan. Although the IRB has been considered as an extension of collision belt between the North China Block (NCB) and South China Block (SCB), there is little geophysical observation or study in and around the IRB. Recently, some geophysical studies including seismological and electromagnetic method have been performed on the middle region of the peninsula, which gives us a valuable opportunity to reveal the characteristic of the IRB. In this study, we show anomalous geophysical evidences observed around the middle of the peninsula. For the electromagnetic anomalies, it may be attributed to enhanced conductivity associated with tectonic events that the Imjin River Belt has experienced. The 3-D electromagnetic modeling results, considering both surrounding seas and enhanced conductivity of the IRB, explain well the anomalous observations around the IRB. From the seismological study, it is demonstrated that focal mechanism around the IRB is mainly normal faulting event, which may be interpreted as the reactivation of paleo structures that are related to the post collisional lithospheric delamination. All the geophysical evidences convince us that the IRB is an extension of the collision belt between the NCB and SCB to the peninsula.

  1. Arctic stratospheric dehydration - Unprecedented observations and microphysical modeling study

    NASA Astrophysics Data System (ADS)

    Engel, Ines; Luo, Beiping P.; Khaykin, Sergey; Wienhold, Frank G.; Vömel, Holger; Kivi, Rigel; Pitts, Michael C.; Poole, Lamont R.; Santee, Michelle L.; Grooß, Jens-Uwe; Peter, Thomas

    2013-04-01

    Polar stratospheric clouds (PSCs) may form in the lower stratosphere above the winter poles at sufficiently low temperatures. Ice PSCs require the coldest conditions, with temperatures some degrees below the frost point to nucleate ice particles. When the particles grow to sizes large enough to sediment, they may result in dehydration, i.e. irreversible redistribution of water vapor, as it frequently occurs above the Antarctic. Conversely, there are no observations above the Arctic that would have provided clear evidence for vertical redistribution of water vapor. Here we report on unequivocal in situ observations in January 2010 above Sodankylä, Finland, which mesh with vortex-wide satellite measurements. Within the LABPIAT-II field campaign, a series of balloon-borne aerosol backscatter and water vapor measurements has been performed. The balloon payload comprised the backscatter sonde COBALD in combination with the cryogenic frost point hygrometer CFH and the fluorescent Lyman-Alpha stratospheric hygrometer FLASH-B. Together with satellite measurements from the Aura microwave limb sounder MLS and the cloud-aerosol lidar CALIOP, a unique and coherent picture of de- and rehydration in the Arctic vortex will be presented within this paper. An extensive coverage of synoptic scale ice PSCs has been observed by CALIOP and COBALD by mid-January due to exceptionally low temperatures in the Arctic vortex. This observation goes along with a simultaneously measured strong reduction in water vapor by 1.6 ppmv relative to background conditions. Subsequent sedimentation and sublimation of ice particles led to a vertical redistribution of water inside the vortex, which was tracked remotely and could be quantified again by in situ measurements some five days later. By means of a microphysical column model, we are able to connect the individual balloon soundings by trajectories and simulate the formation, evolution and sedimentation of the ice particles. Simulated water vapor profiles are verified by CFH, FLASH-B and MLS measurements. Optical T-Matrix calculations enable us to additionally compare the simulations with COBALD and CALIOP backscatter measurements. We examine the effect of different PSC formation pathways - in particular homogeneous vs. heterogeneous ice formation - and changing temperatures and finally show that synoptic scale ice PSCs and concurrent reduction in water vapor are tightly linked with the observed de- and rehydration signatures.

  2. 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

  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. Methods for Studying Tank Armament Materials.

    ERIC Educational Resources Information Center

    Rogov, I. V.

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

  5. Orbital roulette: a new method of gravity estimation from observed motions

    E-print Network

    Beloborodov, A M; Beloborodov, Andrei M.; levin, Yuri

    2004-01-01

    The traditional way of estimating the gravitational field from observed motions of test objects is based on the virial relation between their kinetic and potential energy. We find a more efficient method. It is based on the natural presumption that the objects are observed at a random moment of time and therefore have random orbital time phases. The proposed estimator, which we call "orbital roulette", checks the randomness of the phases. The method has the following advantages: (1) It estimates accurately Keplerian (point-mass) potentials as well as non-Keplerian potentials where the unknown gravitating mass is distributed in space. (2) It is a complete statistical estimator: it checks a trial potential and accepts it or rules it out with a certain significance level; the best-fit measurement is thus supplemented with error bars at any confidence level. (3) It needs no a priori assumptions about the distribution of orbital parameters of the test bodies. We test our estimator with Monte-Carlo-generated motion...

  6. Orbital Roulette: A New Method of Gravity Estimation from Observed Motions

    NASA Astrophysics Data System (ADS)

    Beloborodov, Andrei M.; Levin, Yuri

    2004-09-01

    The traditional way of estimating the gravitational field from observed motions of test objects is based on the virial relation between their kinetic and potential energy. We find a more efficient method. It is based on the natural presumption that the objects are observed at a random moment of time and therefore have random orbital time phases. The proposed estimator, which we call ``orbital roulette,'' checks the randomness of the phases. The method has the following advantages: (1) It accurately estimates Keplerian (point-mass) potentials as well as non-Keplerian potentials, where the unknown gravitating mass is distributed in space. (2) It is a complete statistical estimator: it checks a trial potential and accepts it or rules it out with a certain significance level; the best-fit measurement is thus supplemented with error bars at any confidence level. (3) It needs no a priori assumptions about the distribution of orbital parameters of the test bodies. We test our estimator with Monte Carlo-generated motions and demonstrate its efficiency. Useful applications include the Galactic Center, dark-matter halo of the Galaxy, and clusters of stars or galaxies.

  7. Orbital roulette: a new method of gravity estimation from observed motions

    E-print Network

    Andrei M. Beloborodov; Yuri levin

    2004-05-27

    The traditional way of estimating the gravitational field from observed motions of test objects is based on the virial relation between their kinetic and potential energy. We find a more efficient method. It is based on the natural presumption that the objects are observed at a random moment of time and therefore have random orbital time phases. The proposed estimator, which we call "orbital roulette", checks the randomness of the phases. The method has the following advantages: (1) It estimates accurately Keplerian (point-mass) potentials as well as non-Keplerian potentials where the unknown gravitating mass is distributed in space. (2) It is a complete statistical estimator: it checks a trial potential and accepts it or rules it out with a certain significance level; the best-fit measurement is thus supplemented with error bars at any confidence level. (3) It needs no a priori assumptions about the distribution of orbital parameters of the test bodies. We test our estimator with Monte-Carlo-generated motions and demonstrate its efficiency. Useful applications include the Galactic Center, dark-matter halo of the Galaxy, and clusters of stars or galaxies.

  8. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  12. Optical correlation method for studying disperse media

    NASA Astrophysics Data System (ADS)

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

    1993-10-01

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

  13. 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

  14. 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.

  15. Study Methods to Standardize Thermography NDE

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Workman, Gary L.

    1998-01-01

    The purpose of this work is to develop thermographic inspection methods and standards for use in evaluating structural composites and aerospace hardware. Qualification techniques and calibration methods are investigated to standardize the thermographic method for use in the field. Along with the inspections of test standards structural hardware, support hardware is designed and fabricated to aid in the thermographic process. Also, a standard operating procedure is developed for performing inspections with the Bales Thermal Image Processor (TIP). Inspections are performed on a broad range of structural composites. These materials include 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.

  16. 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.

  17. A new method for quality control of Chinese rawinsonde wind observations

    NASA Astrophysics Data System (ADS)

    Liao, Jie; Wang, Bin; Li, Qingxiang

    2014-11-01

    In 2006, the National Meteorological Information Center (NMIC) of the China Meteorological Administration (CMA) developed its real-time quality control (QC) system of rawinsonde observations coming from the Global Telecommunications System (GTS) and established the Global Upper-air Report Dataset, which, with the NMIC B01 format, is generally referred to as the B01 dataset and updated on a daily basis. However, when the B01 dataset is applied in climate analysis, some wind errors as well as some accurate values with incorrect error marks are found. To improve the quality and usefulness of Chinese rawinsonde wind observations, a new QC method (NewQC) is proposed in this paper. Different from the QC approach used for B01 datasets, the NewQC includes two vertical-wind-shear checks to analyze the vertical consistency of winds, in which the constant height level winds are used as reference data for the QC of mandatory pressure level winds. Different threshold values are adopted in the wind shear checks for different stations and different vertical levels. Several typical examples of QC of different error types by the new algorithm are shown and its performance with respect to 1980-2008 observational data is statistically evaluated. Compared with the radiosonde QC algorithms used in both the Meteorological Assimilation Data Ingest System (MADIS, http://madis.noaa.gov/madis_raob_qc.html) of the National Oceanic and Atmospheric Administration (NOAA) and the B01 dataset, the NewQC shows higher accuracy and better reliability, particularly when used to judge successive observation errors.

  18. 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.

  19. 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

  20. 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.

  1. Study on the Methods of Payment with Mergers & Acquisitions

    Microsoft Academic Search

    Jing Zhang; Yong’an Zhang

    \\u000a Selection of Methods of payment with Mergers & Acquisition (M&A), is the key of a successful M&A. Methods of payment includes\\u000a cash payment, security payment and leveraged buyout. This paper studies the impacts of the selection of payment methods with\\u000a M&A on the selection of financing methods with M&A. This paper also studies the influences of payment methods on the

  2. Optical methods of studying the explosion of shaped charges

    Microsoft Academic Search

    V. S. Zhuchenko; G. P. Postnikov; N. V. Shikunov

    1995-01-01

    This article describes a group of optical methods for studying the explosion of shaped charges, including modifications of\\u000a established methods (slit photorecording, the luminous points method, laser probing) and two new methods — measurement of\\u000a wave velocities with transducers based on optical fibers and laser visualization of the shaped-charge jet. Optical methods\\u000a are used to study such jets under laboratory

  3. 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

  4. The effect of regular antenatal perineal massage on postnatal pain and anal sphincter injury: A prospective observational study

    Microsoft Academic Search

    Maeve Eogan; Leslie Daly; Colm O'Herlihy

    2006-01-01

    Objective. Antenatal perineal massage has been shown to reduce the incidence of perineal tears in primiparous women. The aim of this study was to determine whether perineal massage impacts on primary prevention of symptomatic disruption of the fecal continence mechanism. Methods. An observational study recruited two cohorts of women. The first, massage group (MG) chose to perform daily perineal massage

  5. Observation study of electronic portal images for off-line verication Sophie Lavertu*, Louis-Martin Girouard, Jean Pouliot

    E-print Network

    Pouliot, Jean

    Observation study of electronic portal images for off-line veri®cation Sophie Lavertu*, Louis of this study were to evaluate the use of electronic portal imaging device (EPID) paper images as off-line veri and methods: Electronic portal images were acquired using a video-based imaging system. After contrast

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

    ERIC Educational Resources Information Center

    Rickles, Jordan H.

    2012-01-01

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

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-20

    ...Institutes of Health Proposed Collection; Comment Request; Women's Health Initiative Observational Study SUMMARY: In compliance...review and approval. Proposed Collection Title: The Women's Health Initiative (WHI) Observational Study. Type of...

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ...Institutes of Health Proposed Collection; Comment Request: Women's Health Initiative Observational Study SUMMARY: In compliance...review and approval. Proposed Collection: Title: The Women's Health Initiative (WHI) Observational Study. Type of...

  10. Microfabrication methods for the study of chemotaxis

    E-print Network

    Shur, Maiya, 1980-

    2004-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  12. Trauma airway management in emergency departments: a multicentre, prospective, observational study in Japan

    PubMed Central

    Nakao, Shunichiro; Kimura, Akio; Hagiwara, Yusuke; Hasegawa, Kohei

    2015-01-01

    Objectives Although successful airway management is essential for emergency trauma care, comprehensive studies are limited. We sought to characterise current trauma care practice of airway management in the emergency departments (EDs) in Japan. Design Analysis of data from a prospective, observational, multicentre registry—the Japanese Emergency Airway Network (JEAN) registry. Setting 13 academic and community EDs from different geographic regions across Japan. Participants 723 trauma patients who underwent emergency intubation from March 2010 through August 2012. Outcome measures ED characteristics, patient and operator demographics, methods of airway management, intubation success or failure at each attempt and adverse events. Results A total of 723 trauma patients who underwent emergency intubation were eligible for the analysis. Traumatic cardiac arrest comprised 32.6% (95% CI 29.3% to 36.1%) of patients. Rapid sequence intubation (RSI) was the initial method chosen in 23.9% (95% CI 21.0% to 27.2%) of all trauma patients and in 35.5% (95% CI 31.4% to 39.9%) of patients without cardiac arrest. Overall, intubation was successful in ?3 attempts in 96% of patients (95% CI 94.3% to 97.2%). There was a wide variation in the initial methods of intubation; RSI as the initial method was performed in 0–50.9% of all trauma patients among 12 EDs. Similarly, there was a wide variation in success rates and adverse event rates across the EDs. Success rates varied between 35.5% and 90.5% at the first attempt, and 85.1% and 100% within three attempts across the 12 EDs. Conclusions In this multicentre prospective study in Japan, we observed a high overall success rate in airway management during trauma care. However, the methods of intubation and success rates were highly variable among hospitals. PMID:25652800

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

    PubMed Central

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

    2012-01-01

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

  14. 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…

  15. 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...

  16. 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…

  17. 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...

  18. 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…

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

    NASA Astrophysics Data System (ADS)

    Carson, Jennifer Elaine

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

  20. 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.

  1. Methods to study CFTR protein in vitro.

    PubMed

    Benos, Dale J; Berdiev, Bakhrom K; Ismailov, Iskander I; Ostedgaard, Lynda S; Kogan, Ilana; Li, Canhui; Ramjeesingh, Mohabir; Bear, Christine E

    2004-08-01

    CFTR is a cyclic AMP and nucleotide-related chloride-selective channel with a low unitary conductance. Many of the physiological roles of CFTR are effectively studied in intact cells and tissues. However, there are also several clear advantages to the application of cell-free technologies to the study of the biochemical and biophysical properties of CFTR. When expressed in heterologous cells, CFTR is processed relatively poorly, depending, however, on the cell-type analysed. In some cells, only 20-25% of the protein which is initially synthesized exits the endoplasmic reticulum to insert into the cell membrane [Cell 83 (1995) 121; EMBO J. 13 (1994) 6076]. Further, many of the disease-causing mutants of CFTR result in even lower processing efficiencies. Therefore, several procedures have been developed to study regulated CFTR channel function expressed in microsomal membranes and following its purification and reconstitution. These experimental approaches and their application are discussed here. PMID:15463933

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

    EPA Science Inventory

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

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

    Microsoft Academic Search

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

    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)

  4. 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

  5. Two-photon echo method for observing electron zitterbewegung in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Rusin, Tomasz M.; Zawadzki, Wlodek

    2014-12-01

    The phenomenon of zitterbewegung (ZB, trembling motion) of electrons is described in zigzag carbon nanotubes (CNT) excited by laser pulses. The tight binding approach is used for the band structure of CNT and the effect of light is introduced by the vector potential. Contrary to the common theoretical practice, no a priori assumptions are made concerning electron wave packet; the latter is determined as a result of illumination. In order to overcome the problem of various electron phases in ZB, a method of two-photon echo (2PE) is considered and described using the density function formalism. The medium polarization of CNT is calculated by computing exact solutions of the time-dependent electron Hamiltonian. The signal of 2PE is extracted and it is shown that, using existing parameters of CNT and laser pulses, one should be able to observe the electron trembling motion. Effects of electron decoherence and relaxation are discussed.

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

    NASA Technical Reports Server (NTRS)

    Southworth, R. B.; Sekanina, Z.

    1974-01-01

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

  7. Carpal tunnel syndrome diagnosed by general practitioners: an observational study.

    PubMed

    Claes, F; Bernsen, H; Meulstee, J; Verhagen, W I M

    2012-10-01

    The aim of this study was to investigate the results of both clinical testing and standardised nerve conduction studies performed on patients with Carpal tunnel syndrome (CTS) complaints, who had been referred to the neurologist by their general practitioners. Analysis of the data of neurological examination and electrodiagnostic tests (EDX) were performed on patients that had been referred by general practitioners. A total of 232 patients with clinically defined CTS, who had been referred by general practitioners, were seen by a neurologist and subsequently underwent electrodiagnostic testing. The diagnosis of CTS made by general practitioners was clinically confirmed by the neurologist in 187 of 232 (81%) patients. In these 187 patients, EDX confirmed CTS clinical diagnosis in 180. In 40 (17%), the neurologists disagreed with the clinical diagnosis of CTS because signs and symptoms were not those of clinical CTS. We showed that general practitioners are very well capable of making a clinical diagnosis of CTS. Therefore, direct referral of patients by general practitioners for nerve conduction studies to have their diagnosis of CTS confirmed is a desirable and time-saving procedure. PMID:22198648

  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. Electrochemotherapy with intravenous bleomycin injection: an observational study in superficial squamous cell carcinoma in cats.

    PubMed

    Tozon, Natasa; Pavlin, Darja; Sersa, Gregor; Dolinsek, Tanja; Cemazar, Maja

    2014-04-01

    The aim of this study was to evaluate the efficacy and safety of electrochemotherapy (ECT) with bleomycin for treatment of squamous cell carcinoma (SCC) in cats. Between March 2008 and October 2011, 11 cats with 17 superficial SCC nodules in different clinical stages (ranging from Tis to T4), located on nasal planum (6/11), pinnae (3/11) and both locations (2/11), were included in a prospective non-randomised study. Sixteen of 17 SCC nodules were treated with ECT (15/16 with single session and in one case with two sessions); one nodule was surgically removed. Altogether, complete response (CR) was achieved for 81.8% (9/11) cats and 87.5% (14/16) nodules, lasting from 2 months up to longer than 3 years. Only 2/9 cats in which CR was initially observed, had recurrence 2 and 8 months after the ECT procedure. In the remaining two cats with highly infiltrative spread into adjacent tissues, progression of the disease was observed, despite ECT, and both were euthanased 4 and 5 months after the procedure. ECT in cats was well tolerated and no evident local or systemic side effects were observed. The results of this study suggest that ECT is a highly effective and safe method of local tumour control of feline cutaneous SCCs. It should be considered as an alternative treatment option, especially when other treatment approaches are not acceptable by the owners, owing to their invasiveness, mutilation or high cost. PMID:24127456

  10. Hertfordshire sarcopenia study: design and methods

    Microsoft Academic Search

    Harnish P Patel; Holly E Syddall; Helen J Martin; Claire E Stewart; Cyrus Cooper; Avan Aihie Sayer

    2010-01-01

    BACKGROUND: Sarcopenia is defined as the loss of muscle mass and strength with age. Although a number of adult influences are recognised, there remains considerable unexplained variation in muscle mass and strength between older individuals. This has focused attention on influences operating earlier in life. Our objective for this study was to identify life course influences on muscle mass and

  11. Experimental Study on Neuronal Spike Sorting Methods

    Microsoft Academic Search

    Jianhua Dai; Xiaochun Liu; Yu Yi; Huaijian Zhang; Jingjing Wang; Shaomin Zhang; Xiaoxiang Zheng

    2008-01-01

    When recording extracellular neural activity, it is often necessary to distinguish action potentials arising from distinct cells near the electrode tip, a process commonly referred to as spike sorting or action potential sorting. Sorting of neuronal spikes plays a very important role in coding of neural information, which is a prerequisite for studying the brain function. In this paper, five

  12. Method for Studying Helicopter Longitudinal Maneuver Stability

    NASA Technical Reports Server (NTRS)

    Amer, Kenneth B

    1954-01-01

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

  13. Evaluation of the method to derive the stratospheric lifetime from observed tracer-tracer-correlations

    NASA Astrophysics Data System (ADS)

    Ostermöller, Jennifer; Boenisch, Harald; Engel, Andreas; Liang, Qing

    2013-04-01

    The atmospheric lifetime of a trace gas is defined as the ratio of its global atmospheric burden to its annually averaged global loss rate. Here, we are interested in the lifetimes of the dominant ozone-depleting substances (ODS), which are the prerequisite for the calculation of their ozone-depletion potentials (ODPs). Due to the fact that there is some evidence that the lifetimes for some important ODSs like CFC-11 may be somewhat longer than reported in past WMO assessments the re-evaluation of the dominant ODP lifetimes will be done in the framework of SPARC. Some of the most important ODSs, i.e. CFCs, have solely stratospheric sinks and their stratospheric equals their atmospheric lifetime. For these compounds, the use of tracer-tracer correlation as described by Volk et al. (1997) is the only way that allows to calculate stratospheric lifetimes from solely observations. We will present an evaluation of this method using the results of the GEOS Chemistry-Climate Model (CCM). Hereby, the modelled lifetime serves as an independent reference for the lifetime calculated from the tracer-tracer correlation consistently derived from the same model experiment. We will discuss the implications of these results on the validity and applicability of the method for lifetime calculations described by Volk et al. (1997). Volk, C. M., Elkins, J. W., Fahey, D. W., Dutton, G. S., Gilligan, J. M., Loewenstein, M., Podolske, J. R., Chan, K. R., and Gunson, M. R.: Evaluation of source gas lifetimes from stratospheric observations, J. Geophys. Res., 102, 25543-25564, 1997.

  14. 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

  15. Atmospheric Tides over the Pyrenees. Observational study and numerical simulation

    NASA Astrophysics Data System (ADS)

    Diaz de Argandoña, Javier; Ezcurra, Agustin; Saenz, Jon; Campistron, Bernard; Ibarra-Berastegi, Gabriel; Saïd, Frederique

    2010-05-01

    Atmospheric tides refer to the oscillations in the atmosphere whose periods are integral fractions of a day. In some magnitudes (e.g. temperature), these oscillations are quite evident but in others, such as the pressure in the midlatitudes, they are usually masked by the greater variations produced during the transient pass of synoptic weather systems. The main forcing agent for these oscillations, as opposed to ocean tides, is not the solar or lunar gravity pull, but the daily variations in solar insolation and the thermal effect derived from it. The main components of the solar atmospheric tides are the semidiurnal, with a 12-hour period, and the 24-hour period component or diurnal tide. The global scale tides are usually referred to as migrating tides, and are the result of a gravity wave which travels westerly with the apparent motion of the sun. Nevertheless, a significant part of the tide can be related to local characteristics, and this part is considered as the non-migrating component of the tide. Barometric tides around the Pyrenees mountain range are analyzed by means of ground synoptic stations data recorded during one year, ground data from PYREX experiment and the CRA/LA VHF wind profiler installed in the North of the range. Tides are decomposed in their diurnal and semidiurnal components. Diurnal tides show a strong non migrating component and are very dependent on local conditions. Semidiurnal tides are more homogeneous and present a north-south asymmetry, also noted in the Alps. This cross-range asymmetry seems to be related to some interference effect caused by the mountain range in the migrating semidiurnal tide wave. The diurnal component asymmetry presents a very strong seasonal variation, so its cause must be probably related to thermal local conditions. A three month simulation carried out with NCAR's WRF limited area model reproduces this asymmetry and some of the features of the observed tides.

  16. 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

  17. 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.

  18. 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

  19. Comparative cardiovascular effects of thiazolidinediones: systematic review and meta-analysis of observational studies

    PubMed Central

    2011-01-01

    Objective To determine the comparative effects of the thiazolidinediones (rosiglitazone and pioglitazone) on myocardial infarction, congestive heart failure, and mortality in patients with type 2 diabetes. Design Systematic review and meta-analysis of observational studies. Data sources Searches of Medline and Embase in September 2010. Study selection Observational studies that directly compared the risk of cardiovascular outcomes for rosiglitazone and pioglitazone among patients with type 2 diabetes mellitus were included. Data extraction Random effects meta-analysis (inverse variance method) was used to calculate the odds ratios for cardiovascular outcomes with thiazolidinedione use. The I2 statistic was used to assess statistical heterogeneity. Results Cardiovascular outcomes from 16 observational studies (4 case-control studies and 12 retrospective cohort studies), including 810?000 thiazolidinedione users, were evaluated after a detailed review of 189 citations. Compared with pioglitazone, use of rosiglitazone was associated with a statistically significant increase in the odds of myocardial infarction (n=15 studies; odds ratio 1.16, 95% confidence interval 1.07 to 1.24; P<0.001; I2=46%), congestive heart failure (n=8; 1.22, 1.14 to 1.31; P<0.001; I2=37%), and death (n=8; 1.14, 1.09 to 1.20; P<0.001; I2=0%). Numbers needed to treat to harm (NNH), depending on the population at risk, suggest 170 excess myocardial infarctions, 649 excess cases of heart failure, and 431 excess deaths for every 100?000 patients who receive rosiglitazone rather than pioglitazone. Conclusion Among patients with type 2 diabetes, use of rosiglitazone is associated with significantly higher odds of congestive heart failure, myocardial infarction, and death relative to pioglitazone in real world settings. PMID:21415101

  20. 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.

  1. Estimation of CRF and TRF from VLBI observations by the Least Square Collocation method

    NASA Astrophysics Data System (ADS)

    Kurdubov, S. L.

    2006-08-01

    The aim of this work is to obtain the Terrestrial Reference Frame (TRF), Celestial Reference Frame (CRF) and Earth Orientation Parameters (EOP) series from processing Very Long Baseline Interferometry (VLBI) data by the Least Square Collocation (LSC) method. The observations from 1979 to 2006 were processed with the QUASAR software. More than 4.5 millions delays were used. Coordinates and velocities of 126 VLBI stations and coordinates of 707 radio-sources were estimated. The 12 stations which have more than 200000 observations were used for no-net-translation/no-net-rotation tie to the VTRF2003 catalogue. The 212 defining radio-sources of ICRF-ext.2 were used for no-net-rotation tie to the CRF. The wet component of tropospheric delay and station clock offsets were estimated as sum of polynomial trend and stochastic signal with a-priori defined covariance function. The catalogues with and without stations antenna axis offset estimation were obtained and compared. The obtained solution were compared with other TRF/CRF VLBI solutions and there are showed that the QUASAR LSC solution have the same precision than others.

  2. 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

  3. HEALTHY study rationale, design and methods

    PubMed Central

    2009-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  5. Effective Non-Study Methods for College Students

    ERIC Educational Resources Information Center

    Ludewig, Larry M.

    1975-01-01

    This tongue-in-cheek article is designed to help those people who have no interest in studying, do not like studying, and have no intention of studying. This method is directed to students who live in a dormitory. (Author)

  6. An observational study of arm structure in normal spiral galaxies

    NASA Astrophysics Data System (ADS)

    Magri, Christopher

    Multivariate data were obtained and analyzed in an effort to develop a new classification system for spiral galaxies, one which is not necessarily based on morphological properties. By comparing morphological measures with the intrinsic parameters on which the new system is based, it can be seen just how fundamentally important a galactic property arm structure truly is. A sample of 492 moderately bright northern Sa, SBa, Sc, and SBc spirals was chosen for statistical analysis. The literature was searched for redshifts, optical and near-infrared photometric data, 20 cm fluxes, and H I 21 cm line parameters. New observations were made at 20 and 21 cm; in addition, IRAS fluxes were obtained from archival data. These data were subjected to principal component analysis, modified in that non-detections were explicitly acknowledged. Spiral galaxies have two fundamental properties, confirming previous work done with fewer data. While scale (bulk) is most important, galaxies of given scale can vary in form (color, bulge/disk ratio, H I surface density). Arm strength is unrelated to other properties. Forty-five spatially isolated spirals were chosen for two-color optical CCD imaging, for 20 cm continuum imaging, and for CO 2.6 mm spectroscopy. Isolated Sa's are often found to be misclassified; they are either armless SO's or else peculiar victims of collisions. Isolated Sc's are surprising in that all but the most isolated examples have symmetric arms over at least part of the disk, contrary to the predictions of stochastic models for arm formation. Given the extreme isolation of all highly chaotic disks, the presence of tidal companions (or at least candidates) for the other normal isolated spirals, the apparent prevalence of violent processes in isolated Sa's, and recent N-body simulations of tidal encounters, it is likely that arm structure in most spirals is produced by tidal encounters with small companions. Arm structure is not an intrinsic property of a given galaxy. All of these results can be explained by supposing that protogalactic environments is the determining influence for spirals.

  7. 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

  8. 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.

  9. 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.

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

    E-print Network

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

    2012-01-01

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

  11. Ultrastructural study of muscle in vocal fold: postmortem damage observations.

    PubMed

    Jotz, Geraldo Pereira; Leão, Henrique Záquia; Coiro, José Rafael Rosito

    2003-12-01

    Various authors have published results related to the ultrastructure of vocal folds in specific areas proceeding from human cadavers. Nevertheless, starting from the premise that a fundamental principle of sampling and the samples should be a true representative of the whole, the authors decided to examine vocal folds from human cadavers and compare them to normal vocal folds from the guinea pig (Cavia porcellus). The findings of these authors demonstrated clearly that the conclusion of Rhodin (1954) is correct, that a biological sample must be preserved immediately after blood circulation ceases, and that the intermediary time between biopsy and fixation cannot be more than 3 minutes. Cells fixed a few hours after death appeared disaggregated, and many of their endocellular components were profoundly altered. The results obtained by the authors suggests that ultrastructural studies with cadaverous material may lead to serious risks or doubts about the accuracy of the results and consequently result in dubious interpretations. PMID:14740927

  12. Integrative methods for studying cardiac energetics.

    PubMed

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

    2015-01-01

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

  13. 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

  14. Observational and modelling studies of Australian severe weather

    NASA Astrophysics Data System (ADS)

    Speer, Milton Samuel

    1998-09-01

    The forecastability of severe weather conditions over sub-tropical Australia are tested with a mesoscale model capable of running at high resolutions over a region of interest anywhere in the world. Improved forecast output, for example, of precipitation, wind speed/direction and humidity which are required to indicate severe weather conditions are dependent on model improvements and the following areas are addressed: (1)data; (2)theory; (3)model; and, (4)computing. The initial condition uncertainty inherent in the data which is used in the analysis to initialise numerical weather prediction (NWP) models is addressed through two ensemble forecasting studies, one on rainfall from a mesoscale system and the other on the central low position, wind and rainfall distribution of an explosive east coast low. Also, relating to data, some major mesoscale phenomena are described in the form of New South Wales coastal ridging which helps produce severe weather in this area and which needs to be captured by a mesoscale NWP model in order that improved predictions can be made. In terms of theory the major focus is on the ensemble methodology and on the use of improved precipitation parameterisations, namely, those of Fritsch-Chappell and Kain-Fritsch. The mesoscale model development is extended through the use of increased resolution studies, for example, by showing statistically significant greater than operational skill in predicting details of wind, relative humidity and temperature patterns both near the surface and above the boundary layer in relation to the Sydney January 1994 bushfire weather; by including an option for a Lagrangian particle dispersion model; and by replacement of a previously inadequate representation of cumulus convection which was required to represent the effects of mesoscale downdrafts which are essential for the successful prediction of the squall-line over Sydney in Chapter 7. Mesoscale weather prediction is one of the so called `grand challenges' of computational science in that it requires large amounts of memory and very efficient use of high performance computers. In this thesis the computations ranged form multiprocessor shared memory main frames; high performance work stations; and, now state-of-the-art Pentium PCs. Each of these machines has its distinct requirements for optimisation. Much work has been dedicated in producing code that transfers easily between platforms.

  15. JAFROC analysis revisited: figure-of-merit considerations for human observer studies

    NASA Astrophysics Data System (ADS)

    Chakraborty, D. P.; Yoon, Hong-Jun

    2009-02-01

    Jackknife alternative free-response receiver operating characteristic (JAFROC) is a method for measuring human observer performance in localization tasks. JAFROC is being increasingly used to evaluate imaging modalities because it has been shown to have greater statistical power than conventional receiver operating characteristic (ROC) analysis, which neglects location information. JAFROC neglects the non-lesion localization marks ("false positives") on abnormal images. JAFROC1 is an alternative method that includes these marks. Both methods are lesion-centric in the sense that they assign equal importance to all lesions; an image with many lesions would tend to dominate the performance metric, and clinically less significant lesions are treated identically as more significant ones. In this paper weighted JAFROC and JAFROC1 analyses are described that treat each abnormal image (not each lesion) as a unit of measurement and account for different lesion clinical significances (weights). Lesion-centric and weighted methods were tested using a simulator that includes multiple-reader multiple-case multiple-modality location level correlations. For comparison, ROC analysis was also tested where the rating of the highest rated mark on an image was assumed to be its "ROC" rating. The testing involved random numbers of lesions per image, random weights, case-mixes (ratio of normal to abnormal images) and different correlation structures. We found that for either JAFROC or JAFROC1, both lesion-centric and weighted analyses had correct NH behavior and comparable statistical powers. For either lesion-centric or weighted analyses JAFROC1 yielded the highest power, followed by JAFROC and ROC yielded the least power, confirming a recent study using a less flexible single-reader dual-modality simulator. Provided the number of normal cases is not too small, JAFROC1 is the preferred method for analyzing human observer free-response data. For either JAFROC or JAFROC1 weighted analysis is preferable.

  16. [Perioperative nursing education and client satisfaction: an observational study].

    PubMed

    Mecugni, Daniela; Iemmi, Marina; Formisano, Debora; Caffarri, Cristiana; Brindani, Eleonora

    2011-01-01

    Nowadays, an important goal has been reached in recognizing that the client plays a central role in the caring process. The educational relationship that is created between nurses and patients makes it possible to make the patient aware of his health problems and to understand and actively participate in the caring process. The main aim of this study was to assess the effectiveness of the teaching process undertaken by nurses , before discharging surgical patients , for rendering patients autonomous once they returned home and their level of "satisfaction" regarding the information they received. For this purpose they were asked to fill in a questionnaire when they returned for their first outpatient control. Results showed that, on the whole, patients were satisfied with the information they received during hospitalization, particularly in terms of postoperative pain, prevention of infections, medical therapy, mobilization and a return to normal eating and drinking. Some aspects still need to be improved regarding a post-discharge phone contact and better hospital-territorial integration. PMID:22044546

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

    PubMed

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

    2011-12-01

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

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

    PubMed

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

    2014-11-01

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

  19. An observational study of turbulence in the SPBL

    SciTech Connect

    Kurzeja, R.

    1997-09-01

    Turbulence in the stable planetary boundary layer (SPBL) is complicated by intermittency, gravity waves, long time scales and meso-scale forcing. Surface features and topography are also important. This study examines turbulence near the top of the SPBL with data taken from a network of 61 m towers. The focus is on the role of moderately complex terrain on turbulent intermittency and spatial variation. The Savannah River Site is {approx}150 km from the Atlantic Ocean and is characterized by rolling forested hills and an average elevation of {approx}80 m ASL. Typical variations in elevation are 50 m (peak to valley) with a horizontal scale of several km. The most important topographic feature is the Savannah River flood plain, which borders the SRS to the southwest. This flood plain is 3-7 km wide with an average elevation of 40 m ASL. Nine 60 meter towers are located on the SRS, generally at higher elevations (81 - 109 m ASL), except for the D tower which is in the Savannah River flood plain (elevation 43 m ASL). The Cl tower differs from the other 8 towers because it collects data at 2, 18, and 36 m as well as 61 m. The TV tower, located 8 km northwest of the SRS, is instrumented at 8 levels from the surface to 300 m.

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

    PubMed Central

    2014-01-01

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

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  2. Can we observe and study the Mediterranean outflow and meddies from satellite remote sensing?

    NASA Astrophysics Data System (ADS)

    Yan, Xiao-Hai; Jo, Young-Heon; Liu, W. Timothy; He, Ming-Xia

    2004-02-01

    Previous studies of the Mediterranean outflow and meddies (O&M) were limited by poor spatial and temporal resolution of the conventional observations. Little is known about meddies formation and transport, and the spatial and temporal variation of its trajectories. Generally speaking, most of the satellite observations are confined to the ocean's surface or its surface layer, while meddies were located, on an average, at a depth of 1000m. We developed a new remote sensing method to observe and study the O&M through unique approaches in satellite multi-sensor data integration analyses. Satellite altimeter, scatterometer, SST and XBT data were used to detect and calculate the trajectories and the relative transport of the O&M. We found that more northwestward meddies occurred in the spring and more southward meddies occurred in the fall than previously thought. Since the O&M play a significant role in carrying salty water from the Mediterranean into the Atlantic and contribute to the North Atlantic Deep Water (NADW) formation, such new knowledge about their trajectories, transport and life histories is important to understand their mixing and interaction with the North Atlantic water, adn hence, to lead to a better understanding of the global ocean circulation and the global change.

  3. 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.

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  8. Studies of non-ideal'' superconductors using dc magnetic methods

    SciTech Connect

    Thompson, J.R. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA). Dept. of Physics); Christen, D.K. Kerchner, H.R.; Boatner, L.A.; Sales, B.C.; Chakoumakos, B.C.; Hsu, H.; Brynestad, J.; Kroeger, D.M.; Williams, R.K.; Feenstra, R. (Oak Ridge National Lab., TN (USA)); Sun, Yang Ren; Kim, Y.C.; Ossandon, J.G. (Tennessee Univ., Knoxville, TN (USA). Dept. of Physics); Malozemoff, A.P.; Civa

    1991-01-01

    Among the most informative and facile methods for investigations of a superconductor are measurements of its static magnetization. The objective of this paper is to analyze some experimental features frequently observed in static (dc) magnetization studies of conventional and high-{Tc} superconductors. We shall discuss investigations employing measurement protocols in which the sample is cooled through the superconductive transition temperature in a finite magnetic field ( field cooled'') and compare this with zero-field-cooled studies. Also considered are reversible and irreversible materials; particle size effects; some effects of granular and multiply-connected materials; penetration depth studies of type 2 materials in the vortex state; and fine scale multi-connected'' materials produced by heavy ion irradiation that produces very significant enhancements of the critical current density J{sub c} in the high temperature superconductor Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7}. Many of these superconductors are non-ideal'' in that they may contain defects and inhomogeneities or may have small dimensions comparable with miscroscopic superconductive lengths. Practically speaking, however, such materials are often encountered experimentally and can have very desirable physical properties, such as high J{sub c} values in the ion-irradiated crystal. 33 refs., 9 figs., 1 tab.

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

    PubMed Central

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

    2013-01-01

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

  10. Calcium Channel Blockers and Risk of Breast Cancer: A Meta-Analysis of 17 Observational Studies

    PubMed Central

    Li, Wen; Shi, Qi; Wang, Weibing; Liu, Jianrong; Li, Qi; Hou, Fenggang

    2014-01-01

    Purpose Studies on the association between the use of calcium channel blockers (CCBs) and breast cancer risk have reported inconsistent results. We quantitatively assessed this association by conducting a meta-analysis based on the evidence from observational studies. Methods We searched PubMed, MEDLINE, EMBASE and the Cochrane Library for relevant studies published up to and including December 31, 2013. We calculated pooled risk ratios (RRs) for cancer risk. Results A total of 17 studies (9 cohort studies, 8 case-control studies) were selected for further study. These studies included 149,607 female subjects, of which 53,812 were CCBs users, who were followed for 2–16 years. The risks of breast cancer among patients receiving CCBs were significantly different for the pooled RRs (95% confidence interval) of cohort studies 1.08 (0.95, 1.20) and case-control studies 0.98 (0.86, 1.09). Differences were also noted for cancer risk, for CCBs use of <5 years 0.96 (0.78, 1.15), and for >5 years 1.01 (0.74, 1.28), as well as for ever used 1.08 (0.95, 1.20), and for current use 1.13 (0.83, 1.42). The RR for studies longer than 10 years was 1.71 (1.01, 2.42), and for studies evaluating nifedipine was 1.10 (0.87, 1.33) and diltiazem was 0.75 (0.40, 1.10). Conclusions The long-term use of CCBs appears to have a significant relationship with breast cancer. Well-designed clinical trials are needed to optimize the doses and types of these drugs needed to minimize their carcinogenic potential. PMID:25184210

  11. A comparative study on attitude of contraceptive methods users towards common contraceptive methods

    PubMed Central

    Ehsanpour, Soheila; Mohammadifard, Maedeh; Shahidi, Shahla; Nekouyi, Nafise Sadat

    2010-01-01

    BACKGROUND: Family planning is a method of thinking and a life style which is chosen voluntarily and according to the attitudes and responsible determination of the couples in order to promote the hygiene and convenience of the family. This study aimed to identify and compare the attitudes of the users of common contraceptive methods with regard to each method separately. METHODS: The descriptive study was conducted in 2010. The study samples included 378 women using common contraceptive methods as LD pills, IUD (intrauterine devices), condom, withdrawal, tubectomy (females sterilization) and vasectomy as well as withdrawal method. The samples were selected through systemic random sampling from 9 health care centers. The data collection tool was a researcher-made. In order to determine the validity and reliability of the questionnaires, the content validity and Cronbach's alpha correlation coefficient methods were used. In order to analyze the data, the descriptive and inferential statistical methods (ANOVA) were used. RESULTS: Mean score of attitude regarding different contraceptive methods in the group who were users of the same method was above the users of all the methods; however, total attitude score toward the contraceptive methods was approximately similar to each other in all the groups and there was no significant difference among the different groups. CONCLUSIONS: The findings of this study showed that attitude is an important factor in choosing the contraceptive methods; therefore, this issue should to be taken into account by the family planning planners and consultants. PMID:22069412

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

    E-print Network

    Bogaerts, Steven

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

  13. Qualitative Methods in Empirical Studies of Software Engineering

    E-print Network

    of research. Along with new research questions, new research methods are needed to study nontechnical aspects of software engineering. In many other disciplines, qualitative research methods have been developed]. Qualitative research methods were designed, mostly by educational researchers and other social scientists [19

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

    Microsoft Academic Search

    Shumin Wang; J. Chen

    2005-01-01

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

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

    SciTech Connect

    Vogt, R; Randrup, J

    2011-09-14

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

  16. Observational and modeling studies of heat, moisture, precipitation, and global-scale circulation patterns

    NASA Technical Reports Server (NTRS)

    Vincent, Dayton G.; Robertson, Franklin

    1993-01-01

    The research sponsored by this grant is a continuation and an extension of the work conducted under a previous contract, 'South Pacific Convergence Zone and Global-Scale Circulations'. In the prior work, we conducted a detailed investigation of the South Pacific convergence zone (SPCZ), and documented many of its significant features and characteristics. We also conducted studies of its interaction with global-scale circulation features through the use of both observational and modeling studies. The latter was accomplished toward the end of the contract when Dr. James Hurrell, then a Ph.D. candidate, successfully ported the NASA GLA general circulation model (GCM) to Purdue University. In our present grant, we have expanded our previous research to include studies of other convectively-driven circulation systems in the tropics besides the SPCZ. Furthermore, we have continued to examine the relationship between these convective systems and global-scale circulation patterns. Our recent research efforts have focused on three objectives: (1) determining the periodicity of large-scale bands of organized convection in the tropics, primarily synoptic to intraseasonal time scales in the Southern Hemisphere; (2) examining the relative importance of tropical versus mid-latitude forcing for Southern Hemisphere summertime subtropical jets, particularly over the Pacific Ocean; and (3) estimating tropical precipitation, especially over oceans, using observational and budget methods. A summary list of our most significant accomplishments in the past year is given.

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

    PubMed Central

    Rao, Shobitha; Chogtu, Bharti

    2015-01-01

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

  18. METHODS STUDIES FOR THE NATIONAL CHILDREN'S STUDY: MOLECULARLY IMPRINTED POLYMERS

    EPA Science Inventory

    Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiologic...

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

    EPA Science Inventory

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

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

    ERIC Educational Resources Information Center

    Romano, Jeanine L.; Kromrey, Jeffrey D.

    2009-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Long-Term Treatment of ADHD with Stimulants: A Large Observational Study of Real-Life Patients

    ERIC Educational Resources Information Center

    Powell, Shelagh G.; Thomsen, Per Hove; Frydenberg, Morten; Rasmussen, Helle

    2011-01-01

    Objective: To evaluate 410 real-life patients treated with stimulants and assessed systematically over several years. Method: Naturalistic observational study. A database was compiled on the basis of a review of the medical charts of patients attending a specialized ADHD clinic. Results: The diversity of ADHD patients was evident from the…

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

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

    PubMed Central

    Oliver, Jane; Thomson, George

    2014-01-01

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

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

    PubMed

    Wilson, Nick; Oliver, Jane; Thomson, George

    2014-01-01

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

  6. A portable ergonomic observation method (PEO) for computerized on-line recording of postures and manual handling

    Microsoft Academic Search

    C Fransson-Hall

    1995-01-01

    A new portable ergonomic observation method (PEO) is presented. It is applicable to most professions and work tasks and requires only moderate human resources for data collection and analysis. Observations are made in real time directly at the workplace using a portable personal or hand-held computer, and data are accessible for immediate analysis and presentation. Duration and number of events

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

    E-print Network

    Menke, William

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

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

    EPA Science Inventory

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

  9. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 32: METHOD 450.1 - TOTAL ORGANIC HALIDES (TOX)

    EPA Science Inventory

    The report describes the interlaboratory method study that was performed to evaluate interim Method 450.1 for total organic halides (TOX). In the method, a measured volume of water is passed through two columns in series each containing 40 mg of activated charcoal. Organic halide...

  10. Using Built Environmental Observation Tools: Comparing Two Methods of Creating a Measure of the Built Environment

    PubMed Central

    Keast, Erin M.; Carlson, Nichole E.; Chapman, Nancy J.; Michael, Yvonne L.

    2011-01-01

    Purpose Identify an efficient method of creating a comprehensive and concise measure of the built environment integrating data from geographic information systems (GIS) and the Senior Walking Environmental Assessment Tool (SWEAT). Design Cross-sectional study using a population sample. Setting Eight municipally defined neighborhoods in Portland, Oregon. Subjects Adult residents (N = 120) of audited segments (N = 363). Measures We described built environmental features using SWEAT audits and GIS data. We obtained information on walking behaviors and potential confounders through in-person interviews. Analysis We created two sets of environviental measures, one based on the conceptual framework used to develop SWEAT and another using principal component analysis (PCA). Each measure’s association with walking for transportation and exercise was then assessed and compared using logistic regression. Results A priori measures (destinations, safety, aesthetics, and functionality) and PCA measures (accessibility, comfort/safety, maintenance, and pleasantness) were analogous in conceptual meaning and had similar associations with walking. Walking for transportation was associated with destination accessibility and functional elements, whereas walking for exercise was associated with maintenance of the walking area and protection from traffic. However, only PCA measures consistently reached statistical significance. Conclusion The measures created with PCA were more parsimonious than those created a priori. Performing PCA is an efficient method of combining and scoring SWEAT and GIS data. PMID:20465151

  11. Direct observation of solute location in solutions frozen using various methods

    NASA Astrophysics Data System (ADS)

    Hullar, T.; Anastasio, C.

    2012-12-01

    Photochemical reactions in snow and ice impact the transport and fate of organic and inorganic compounds in the snowpack, particularly in polar regions. While photodegradation rate constants have been determined for relatively few reactions on ice, in some cases different studies give significantly different results for the same reaction. Compounds in snow and ice can be located in several different compartments in the frozen matrix, including in bulk ice, at the ice-air interface in quasi-liquid layers (QLLs), or in liquid-like layers (LLLs) or micropockets within the ice matrix. Reaction rate differences may be due to changes in chemical kinetics in the various compartments, or variation in the photochemical reaction environment, such as photon flux. Here we examine various methods to segregate chemical compounds into different ice compartments by visualizing solute locations in the frozen samples. We preferentially segregate solutes into the various ice compartments by varying sample geometry, freezing speed (how quickly heat is removed from the liquid solution), and freezing direction (whether heat is removed from the solution from all sides equally, or preferentially in a single direction). We examine the results of our freezing methods by preparing ice samples containing a fluorescent solute, then using an imaging cryomicrotome to remove thin slices of the sample and image the remaining ice surface. By measuring the fluorescence from the ice surface as a function of depth, we can determine the location and concentration of the solute in various ice compartments.

  12. Comparative study on Kasisa Bhasma prepared by two different methods

    PubMed Central

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

    2011-01-01

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

  13. Survey of robust residual generation and evaluation methods in observer-based fault detection systems

    Microsoft Academic Search

    P. M. Frank; X. Ding

    1997-01-01

    The paper outlines recent advances of the theory of observer-based fault diagnosis in dynamic systems towards the design of robust techniques of residual generation and residual evaluation. Emphasis will be placed upon the latest contributions using frequency domain techniques including H? theory, nonlinear unknown input observer theory, adaptive observer theory, artificial intelligence including fuzzy logic, knowledge-based techniques and the natural

  14. 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…

  15. Diet Studies of Seabirds: a Review of Methods DAVIDCAMERONDUFFYAND SUSANJACKSON

    E-print Network

    Duffy, David Cameron

    Diet Studies of Seabirds: a Review of Methods DAVIDCAMERONDUFFYAND SUSANJACKSON Pcrcy Fitr.-Mcthods of collecting, analysiog and presenting data on the diets of se;ibirrls are reviewed, with consideration of methods employed in diet studies of other organisms. Killing or hi& continues to bc the primary source

  16. TOOLS AND METHODS FOR STUDIES IN COASTAL ECOLOGY

    E-print Network

    Sealey, Kathleen Sullivan

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

  17. EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 12, CYANIDE IN WATER

    EPA Science Inventory

    EPA Method Study 12, Cyanide in Water reports the results of a study by EMSL-Cincinnati for the parameters, Total Cyanide and Cyanides Amendable to Chlorination, present in water at microgram per liter levels. Four methods: pyridine-pyrazolone, pyridine-barbituric acid, electrode...

  18. NATO PILOT STUDY ON ADVANCED CANCER RISK ASSESSMENT METHODS

    EPA Science Inventory

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

  19. Nuclear-based methods for the study of selenium

    SciTech Connect

    Spyrou, N.M.; Akanle, O.A.; Dhani, A. (Univ. of Surrey (England))

    1988-01-01

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

  20. Association between clinically abnormal observations and subsequent in-hospital mortality: a prospective study

    Microsoft Academic Search

    Michael Buist; Stephen Bernard; Tuan V. Nguyen; Gaye Moore; Jeremy Anderson

    2004-01-01

    Background: Patients with unexpected in-hospital cardiac arrest often have an abnormal clinical observation prior to the arrest. Previous studies have suggested that a medical emergency team responding to such patients may decrease in-hospital mortality from cardiac arrest, but the association between any abnormal clinical observation and subsequent increased mortality has not been studied prospectively. The aim of this study was

  1. Prospective observational cohort studies for studying rare diseases: the European PedNet Haemophilia Registry.

    PubMed

    Fischer, K; Ljung, R; Platokouki, H; Liesner, R; Claeyssens, S; Smink, E; van den Berg, H M

    2014-07-01

    Haemophilia is a rare disease. To improve knowledge, prospective studies of large numbers of subjects are needed. To establish a large well-documented birth cohort of patients with haemophilia enabling studies on early presentation, side effects and outcome of treatment. Twenty-one haemophilia treatment centres have been collecting data on all children with haemophilia with FVIII/IX levels up to 25% born from 2000 onwards. Another eight centres collected data on severe haemophilia A only. At baseline, details on delivery and diagnosis, gene mutation, family history of haemophilia and inhibitors are collected. For the first 75 exposure days, date, reason, dose and product are recorded for each infusion. Clinically relevant inhibitors are defined as follows: at least two positive inhibitor titres and a FVIII/IX recovery <66% of expected. For inhibitor patients, results of all inhibitor- and recovery tests are collected. For continued treatment, data on bleeding, surgery, prophylaxis and clotting factor consumption are collected annually. Data are downloaded for analysis annually. In May 2013, a total of 1094 patients were included: 701 with severe, 146 with moderate and 247 with mild haemophilia. Gene defect data were available for 87.6% of patients with severe haemophilia A. The first analysis, performed in May 2011, lead to two landmark publications. The outcome of this large collaborative research confirms its value for the improvement of haemophilia care. High-quality prospective observational cohorts form an ideal source to study natural history and treatment in rare diseases such as haemophilia. PMID:24784937

  2. A detailed study of equatorial electrojet phenomenon using Ørsted satellite observations

    NASA Astrophysics Data System (ADS)

    Jadhav, Geeta; Rajaram, Mita; Rajaram, R.

    2002-08-01

    Detailed analysis of the scalar magnetic field data from Ørsted satellite for quiet days from April 1999 to March 2000 has been undertaken to study the equatorial electrojet (EEJ) phenomenon. An objective technique has been adopted for the identification of the EEJ from the satellite data and estimation of the standard parameters associated with it. EEJ strength computed using the satellite data and simultaneous ground magnetic observatory data, for the Indian and American sectors, correlate very well authenticating the method used. Estimated zonal variation in the EEJ parameters such as peak current intensity (J0), and total current (I+) are broadly consistent with the earlier observations. We, however, observe that the width of the EEJ varies considerably with longitude, a feature not seen in the Pogo data. The study shows that the EEJ axis (center of EEJ) closely follows the dip equator at altitude of 106 km, but there is a small departure that undergoes diurnal variation, with a minimum at noon. The globally averaged EEJ amplitude follows the expected diurnal pattern. Principal component analysis technique reveals that first four components can explain around two thirds of the electrojet variability. The first component, which contributes a little over 30% to the observed variance, could be identified with the global variation of the EEJ emanating from the day-to-day variability of the migrating tides. The second and fourth components, which account for around 15 and 10% of the variance, respectively, are driven by forcing that depends on whether the location of the EEJ in that sector is in the Northern or Southern Hemisphere. The third component provides maximum contributions wherever the geomagnetic and dip equators are sufficiently close, accounting for 12.5% of the variance. The remaining components could be associated with contribution of nonmigratory tides or other unknown mechanisms. Thus the present study suggests that besides conductivity, atmospheric tidal modes play important role in defining the zonal variability of the EEJ current system.

  3. METHODS ADVANCEMENT FOR MILK ANALYSIS: THE MAMA STUDY

    EPA Science Inventory

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

  4. EQUILIBRIUM STUDY BETWEEN CONDENSED PHASES BY ISOPLETHIC THERMAL ANALYSIS WHEN A MISCIBILITY GAP IS OBSERVED

    E-print Network

    Paris-Sud XI, Université de

    -sodium sulfate- piperidine. The changes in state observed on the thermogram recorded during the displacement analysis, miscibility gap, critical point, piperidine, water, sodium sulfate Introduction Studying a high

  5. 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.

  6. Synchronous Motor Observability Study and an Improved Zero-speed Position Estimation Design

    E-print Network

    Boyer, Edmond

    . The problem of loss of observability at low frequency range is always recognized in experimental settings], the full order and the reduced order observers [2], the LMI based methods [3], the high-frequency signal and to avoid the chattering phenomenon [20]. This paper is organized as follows: In the second sectio

  7. Second-Order Theoretical Analysis of Observations: Data Analysis Through the Study of Dilemmas

    ERIC Educational Resources Information Center

    Shkedi, Asher; Harel, Miri

    2004-01-01

    This paper explains the principles and procedures of second-order theoretical analysis of observation data. The second-order theoretical procedure is illustrated by analysis of the student-teachers seminar on the subject of the Holocaust, focusing on dilemmas of Holocaust survivors. Analysing observational data allows two distinctive method of…

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

    ERIC Educational Resources Information Center

    Schneider, Barry H.

    2009-01-01

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

  9. A distribution-based method to resolve single-molecule Förster resonance energy transfer observations

    E-print Network

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

    2011-04-12

    We introduce a new approach to analyze single-molecule Förster resonance energy transfer (FRET) data. The method recognizes that FRET efficiencies assumed by traditional ensemble methods are unobservable for single molecules. ...

  10. Analyzing Propensity Matched Zero-Inflated Count Outcomes in Observational Studies

    PubMed Central

    DeSantis, Stacia M.; Lazaridis, Christos; Ji, Shuang; Spinale, Francis G.

    2013-01-01

    Determining the effectiveness of different treatments from observational data, which are characterized by imbalance between groups due to lack of randomization, is challenging. Propensity matching is often used to rectify imbalances among prognostic variables. However, there are no guidelines on how appropriately to analyze group matched data when the outcome is a zero inflated count. In addition, there is debate over whether to account for correlation of responses induced by matching, and/or whether to adjust for variables used in generating the propensity score in the final analysis. The aim of this research is to compare covariate unadjusted and adjusted zero-inflated Poisson models that do and do not account for the correlation. A simulation study is conducted, demonstrating that it is necessary to adjust for potential residual confounding, but that accounting for correlation is less important. The methods are applied to a biomedical research data set. PMID:24298197

  11. Analyzing Propensity Matched Zero-Inflated Count Outcomes in Observational Studies.

    PubMed

    Desantis, Stacia M; Lazaridis, Christos; Ji, Shuang; Spinale, Francis G

    2014-01-01

    Determining the effectiveness of different treatments from observational data, which are characterized by imbalance between groups due to lack of randomization, is challenging. Propensity matching is often used to rectify imbalances among prognostic variables. However, there are no guidelines on how appropriately to analyze group matched data when the outcome is a zero inflated count. In addition, there is debate over whether to account for correlation of responses induced by matching, and/or whether to adjust for variables used in generating the propensity score in the final analysis. The aim of this research is to compare covariate unadjusted and adjusted zero-inflated Poisson models that do and do not account for the correlation. A simulation study is conducted, demonstrating that it is necessary to adjust for potential residual confounding, but that accounting for correlation is less important. The methods are applied to a biomedical research data set. PMID:24298197

  12. Tropical cyclone rainfall: An observational and numerical study of the structure and governing physical processes

    NASA Astrophysics Data System (ADS)

    Lonfat, Manuel

    Fresh water flooding has become the largest threat to life at hurricane landfall in the United States, in part because of a lack of skill of current Quantitative Precipitation Forcast (QPF) methods. This study aims to develop a global climatology of tropical cyclone (TC) rainfall and to improve our understanding of physical processes that affect the TC rainfall structure and distribution, using satellite observations and numerical simulations. First, the TC rainfall distributions with respect to the storm intensity and location are examined, using global satellite observations from the Tropical Rainfall Measuring Mission (TRMM). Secondly, numerical simulations using the Penn State/National Centers for Atmospheric Research (NCAR) mesoscale modelling system, version 5 (MM5), are performed to study how specific processes affect the cyclone rainfall. The presence of moisture and momentum sources on a storm's inner core is investigated using a method that modifies the environmental conditions in the model. The mean TC rainfall distribution and the first order asymmetry vary with storm intensity and geographical location among the six oceanic basins. The mean rainfall increases with storm intensity within 250 km of the storm center while the radius of maximum rainfall decreases. The asymmetric component is determined by the first-order Fourier decomposition in a coordinate system relative to storm motion and shear. The rainfall asymmetry with TC motion varies significantly with both storm intensity and geographic location. For the global average of all TCs, the maximum rainfall is located in the front quadrants. However, the global composite asymmetry is larger when analysed with respect to shear. The asymmetry is observed down-shear left (right) in the Northern (Southern) Hemisphere for shear values >7.5 m s -1. The analysis is further extended to examine the net effect of the storm motion and the vertical wind shear. It is found that the storm-motion induced rainfall asymmetry is comparable to that induced by the shear when the shear is <5 m s-1. TC propagation speed becomes more important in the relatively low shear environment. The overall rainfall asymmetry, in all oceanic basins, depends on the angle and relative magnitude between the storm motion and shear vectors. The combined effect of shear and TC propagation speed is further investigated using numerical simulations of Hurricane Floyd (1999). Floyd was a well-observed intense storm that experienced variable environmental shear, from relatively low shear to close to 15 m s-1 high shear during its life cycle. (Abstract shortened by UMI.)

  13. A ternary-arithmetic topological based algebraic method for networks traffic observability

    Microsoft Academic Search

    Enrique Castillo; Pilar Jiménez; José María Menéndez; Ana Rivas; Inmaculada Gallego

    2011-01-01

    In this paper an algebraic method, which shares all the advantages of the topological methods and allows us to obtain the same results as the standard algebraic method with a substantial reduction in memory and cpu requirements, is presented. The main idea consists of writing the link, OD and scanned flows in terms of route instead of OD flows. This

  14. Factors influencing the quality of postoperative epidural analgesia: an observational multicenter study

    PubMed Central

    Wranicz, Piotr; Andersen, Hege; Nordbø, Arve; Kongsgaard, Ulf E

    2014-01-01

    Background Epidural analgesia (EDA) is used widely for postoperative pain treatment. However, studies have reported a failure rate of EDA of up to 30%. We aimed to evaluate the quality of postoperative EDA in patients undergoing a laparotomy in five Norwegian hospitals. Methods This was a multicenter observational study in patients undergoing a laparotomy with epidural-based postoperative analgesia. Data were registered at three time points. Technical aspects, infusion rates, pain intensity, assessment procedures, side effects, and satisfaction of patients and health personnel were recorded. The use of other pain medications and coanalgesics was registered. Results Three hundred and seventeen patients were included. Pain control at rest was satisfactory in 89% of patients at 24 hours and in 91% at 48 hours. Pain control when coughing was satisfactory in 62% at 24 hours and in 59% at 48 hours. The spread of hypoesthesia was consistent for each individual patient but varied between patients. The hypoesthetic area was not associated with pain intensity, and the precision of the EDA insertion point was not associated with the pain score. Few side effects were reported. EDA was regarded as effective and functioning well by 64% of health personnel. Conclusion EDA was an effective method for postoperative pain relief at rest but did not give sufficient pain relief during mobilization. The use of cold stimulation to assess the spread of EDA had limited value as a clinical indicator of the efficacy of postoperative pain control. Validated tools for the control of EDA quality are needed. PMID:25206312

  15. Does fasting in Ramadan ameliorate Lipid profile? A prospective observational study

    PubMed Central

    Akaberi, Arash; Golshan, Alireza; Moojdekanloo, Maryam; Hashemian, Maryam

    2014-01-01

    Background and Objectives: There are conflicting data on the effects of fasting in Ramadan in Muslim countries on Lipid profile. We aimed to evaluate the effect of fasting on lipid profiles and some ratios which are strong for predicting cardiovascular disease. Methods: This prospective observational study was done in Iran in 2012. Forty three persons were enrolled into the study. Their anthropometric measurement was done. Fasting plasma high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), total cholesterol (TC), and triglyceride (TG) were measured at baseline and after one month fasting during Ramadan by standard methods. Paired t test were used to compare lipid profiles before and after the intervention. Results : High density lipoprotein cholesterol was 33.10±6.53 mg/dL at baseline and increased to 42.49±8.44mg/dL (P <0.001). Fasting in Ramadan decreased serum LDL/HDL and TG/HDL ratios significantly (P <0.001). Triglyceride levels were unaffected. Low density lipoprotein and total cholesterol levels increased (P=0.008). Changes did not differ significantly between men and women. Conclusion: Fasting in Ramadan is effective to ameliorate High density lipoprotein, and LDL/HDL and TG/HDL ratios. Omitting one meal may be considered to control High density lipoprotein level. PMID:25097501

  16. Family Practitioners' Diagnostic Decision-Making Processes Regarding Patients with Respiratory Tract Infections: An Observational Study

    Microsoft Academic Search

    Thomas Fischer; Susanne Fischer; Wolfgang Himmel

    Background. The influence of patient characteristics on family practitioners' (FPs') diagnostic decision making has mainly been investigated using indirect methods such as vignettes or questionnaires. Direct observation—borrowed from social and cultural anthropology— may be an alterna- tive method for describing FPs' real-life behavior and may help in gaining insight into how FPs diagnose respiratory tract infections, which are frequent in

  17. A study on adaptive load torque observer for robust precision position control of BLDC motor

    Microsoft Academic Search

    Jong Sun Ko; Sung Koo Youn; Bimal K. Bose

    1999-01-01

    A new control method for precision robust position control of a brushless DC (BLDC) motor using asymptotically stable adaptive load torque observer is presented in the paper. Precision position control is obtained for the BLDC motor system approximately linearized using the field-orientation method. Many of these drive systems use BLDC motors to avoid backlash. However, the disadvantages of the motor

  18. An observational study of intravenous medication errors in the United Kingdom and in Germany

    Microsoft Academic Search

    V. Wirtz; Nick D. Barber; K. taxis

    2003-01-01

    Objectives: To investigate the incidence and the severity of intravenous (i.v.) drug preparation and administration errors in two countries and three pharmacy services. Method: A disguised observational method was used to record details of the preparation and administration of prescribed i.v. drugs on two wards in each of three teaching hospitals: one with a traditional British ward pharmacy service (TBP)

  19. IRT studies of many groups: the alignment method

    PubMed Central

    Muthén, Bengt; Asparouhov, Tihomir

    2014-01-01

    Asparouhov and Muthén (2014) presented a new method for multiple-group confirmatory factor analysis (CFA), referred to as the alignment method. The alignment method can be used to estimate group-specific factor means and variances without requiring exact measurement invariance. A strength of the method is the ability to conveniently estimate models for many groups, such as with comparisons of countries. This paper focuses on IRT applications of the alignment method. An empirical investigation is made of binary knowledge items administered in two separate surveys of a set of countries. A Monte Carlo study is presented that shows how the quality of the alignment can be assessed. PMID:25309470

  20. Using peer observers to assess the quality of cancer multidisciplinary team meetings: a qualitative proof of concept study

    PubMed Central

    Harris, Jenny; Green, James SA; Sevdalis, Nick; Taylor, Cath

    2014-01-01

    Background Multidisciplinary team (MDT) working is well established as the foundation for providing cancer services in the UK and elsewhere. A core activity is the weekly meeting (or case conference/tumor boards) where the treatment recommendations for individual patients are agreed. Evidence suggests that the quality of team working varies across cancer teams, and this may impact negatively on the decision-making process, and ultimately patient care. Feedback on performance by expert observers may improve performance, but can be resource-intensive to implement. This proof of concept study sought to: develop a structured observational assessment tool for use by peers (managers or clinicians from the local workforce) and explore its usability; assess the feasibility of the principle of observational assessment by peers; and explore the views of MDT members and observers about the utility of feedback from observational assessment. Methods For tool development, the content was informed by national clinical consensus recommendations for best practice in cancer MDTs and developed in collaboration with an expert steering group. It consisted of ten subdomains of team working observable in MDT meetings that were rated on a 10-point scale (very poor to very good). For observational assessment, a total of 19 peer observers used the tool (assessing performance in 20 cancer teams from four hospitals). For evaluation, telephone interviews with 64 team members and all peer observers were analyzed thematically. Results The tool was easy to use and areas for refinement were identified. Peer observers were identified and most indicated that undertaking observation was feasible. MDT members generally reported that observational assessment and feedback was useful, with the potential to facilitate improvements in team working. Conclusion This study suggests that observation and feedback by peers may provide a feasible and acceptable approach to enhance MDT performance. Further tool refinement and validation is required. PMID:25143743

  1. Hyperuricemia and Risk of Incident Hypertension: A Systematic Review and Meta-Analysis of Observational Studies

    PubMed Central

    Chen, Jianrong; Li, Yulin; Wang, Ling; Huang, He; Li, Jing

    2014-01-01

    Background Observational studies of the relationship between hyperuricemia and the incidence of hypertension are controversial. We conducted a systematic review and meta-analysis to assess the association and consistency between uric acid levels and the risk of hypertension development. Methods We searched MEDLINE, EMBASE, CBM (Chinese Biomedicine Database) through September 2013 and reference lists of retrieved studies to identify cohort studies and nested case-control studies with uric acid levels as exposure and incident hypertension as outcome variables. Two reviewers independently extracted data and assessed study quality using Newcastle-Ottawa Scale. Extracted information included study design, population, definition of hyperuricemia and hypertension, number of incident hypertension, effect sizes, and adjusted confounders. Pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) for the association between hyperuricemia and risk of hypertension were calculated using a random-effects model. Results We included 25 studies with 97,824 participants assessing the association between uric acid and incident hypertension in our meta-analysis. The quality of included studies is moderate to high. Random-effects meta-analysis showed that hyperuricemia was associated with a higher risk of incident hypertension, regardless of whether the effect size was adjusted or not, whether the data were categorical or continuous as 1 SD/1 mg/dl increase in uric acid level (unadjusted: RR?=?1.73, 95% CI 1.46?2.06 for categorical data, RR?=?1.22, 95% CI 1.03?1.45 for a 1 SD increase; adjusted: RR?=?1.48, 95% CI 1.33?1.65 for categorical data, RR?=?1.15, 95% CI 1.06?1.26 for a 1 mg/dl increase), and the risk is consistent in subgroup analyses and have a dose-response relationship. Conclusions Hyperuricemia may modestly increase the risk of hypertension incidence, consistent with a dose-response relationship. PMID:25437867

  2. Detection Method and Observed Data of High-energy Gamma Rays under the Influence of Quantum Gravity

    NASA Astrophysics Data System (ADS)

    Kifune, T.

    2014-05-01

    The interaction of high-energy particles affected by quantum gravity is argued from the experimental viewpoint of raising a question, ``our detection method for high-energy ?-rays supplies trustworthy observation data and we are now seeing the true image of the universe through high-energy ?-rays?" The modified dispersion relation (MDR) for particles' energy and momentum is applied to the equation of energy-momentum conservation in particle reactions, to study the restriction imposed on the kinematic state of high-energy particles by the Lorentz invariance violation (LIV) due to quantum gravity, as a function of the incident particle energy of the reaction. The result suggests that the interaction utilized for ?-ray detection is not free from the effect of quantum gravity when ?-ray energy is higher than 1013 ~ 1017 eV depending on models of MDR. Discussion is presented on the prospect of finding clear evidence of the LIV effect from ?-ray observations, as well as on the radiation and propagation mechanism of ?-rays under the influence of the LIV effect.

  3. Comparative study of two extraction methods for enteric virus recovery from sewage sludge by molecular methods.

    PubMed

    Schlindwein, A D; Simões, C M O; Barardi, C R M

    2009-07-01

    The aim of this study was to compare two nucleic acid extraction methods for the recovery of enteric viruses from activated sludge. Test samples were inoculated with human adenovirus (AdV), hepatitis A virus (HAV), poliovirus (PV) and rotavirus (RV) and were then processed by an adsorption-elution-precipitation method. Two extraction methods were used: an organic solvent-based method and a silica method. The organic-based method was able to recoup 20% of the AdV, 90% of the RV and 100% of both the PV and HAV from seeded samples. The silica method was able to recoup 1.8% of the AdV and 90% of the RV. These results indicate that the organic-based method is more suitable for detecting viruses in sewage sludge. PMID:19722079

  4. Unsafe riding practice among electric bikers in Suzhou, China: an observational study

    PubMed Central

    Yang, Jie; Hu, Yihe; Du, Wei; Powis, Brent; Ozanne-Smith, Joan; Liao, Yilan; Li, Ning; Wu, Ming

    2014-01-01

    Background Electric bike (E-bike)-related deaths have been increasing rapidly in China and such injuries may be partly attributable to unsafe riding practice. Objectives To describe potentially unsafe riding behaviours among electric bikers (E-bikers) and to investigate factors influencing these practices in China. Methods In September 2012, a cross-sectional observation study including a speed measurement component was conducted in Wuzhong (an urban district) and Zhangjiagang (a rural district) of Suzhou, Jiangsu Province, China. Hand-held radar speed metres were used to read travelling speeds of E-bikes and a pro forma observation checklist was used to collect data on road riding practice. Mixed-effect logistic regressions were used to calculate adjusted ORs and 95% CIs for the association between speeding, road rule violations and helmet use and their influencing factors. Results Among 800 E-bikes with a speed reading, 70.9% exceeded the designed speed limit of 20?km/h. Among a further 20?647 E-bikers observed, 38.3% did not comply with the road rules when entering intersections; and only 2.2% wore helmets. No regional variation was identified between urban and rural areas. Male E-bikers were associated with more speeding and road rule violations, whereas riding a pedal-equipped E-bike was associated with less road rule violations and less helmet use. Conclusions Unsafe riding practices such as speeding, road rule violations and lack of helmet use were commonplace among E-bikers, especially among men. The study findings indicate that measures aimed at improving E-bike safety are required in China. PMID:24435891

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

    PubMed Central

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  7. Hyperthermic intraperitoneal chemotherapy with cisplatin and paclitaxel in advanced ovarian cancer: a multicenter prospective observational study

    PubMed Central

    Coccolini, Federico; Campanati, Luca; Catena, Fausto; Ceni, Valentina; Jimenez Cruz, Jorge; Lotti, Marco; Magnone, Stefano; Napoli, Josephine; Rossetti, Diego; De Iaco, Pierandrea; Frigerio, Luigi; Pinna, Antonio; Runnebaum, Ingo; Ansaloni, Luca

    2015-01-01

    Objective Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been recently reported with favorable oncological outcomes as treatment of advanced epithelial ovarian cancer (EOC). The aim of this study was to demonstrate the feasibility of CRS+HIPEC with cisplatin and paclitaxel for the treatment of advanced EOC. Methods This is a prospective observational study of 54 patients, from April 2007 to October 2013, with primary or recurrent peritoneal carcinomatosis due to EOC. The mean age was 54.51±9.34. Thirty patients (59%) had primary EOC, and 24 patients (41%) had recurrent disease. Results Mean peritoneal cancer index was 10.11 (range, 0 to 28), complete cytoreduction (CC0) was achieved for 47 patients (87%), CC1 for seven patients (13%). Patients with suboptimal cytoreduction (CC2 and CC3) were not included in the study. The mean stay in intensive care unit was 4.73±5.51 days and the mean hospitalization time was 24.0±10.03 days. We did not observe any intraoperative death. Seven patients (13%) required additional operations. Three patients (5.6%) died within 30 days from the procedure. Severe complications were seen in 19 patients (35.2%). During the follow-up period, disease recurred in 33 patients (61.1%); the median disease-free survival time was 12.46 months and the median overall survival time was 32.91 months. Conclusion CRS+HIPEC with cisplatin and paclitaxel for advanced EOC is feasible with acceptable morbidity and mortality. Additional follow-up and further studies are needed to determine the effects of HIPEC on long term survival. PMID:25376916

  8. SOSPES: SPIRIVA® observational study measuring SGRQ score in routine medical practice in Central and Eastern Europe

    PubMed Central

    Fležar, Matjaž; Jahnz-Ró?yk, Karina; Enache, Gloria; Martynenko, Tatiana; Kristufek, Peter; Škrinjari?-Cincar, Sanda; Kadlecová, Pavla; Martinovic, Goran

    2013-01-01

    Purpose The long-acting inhaled anticholinergic agent, tiotropium, is recommended as first-line maintenance therapy for moderate to very severe Chronic Obstructive Pulmonary Disease (COPD) to improve symptoms, exercise tolerance, health status, and to reduce exacerbations. Few studies have evaluated the therapeutic efficacy of tiotropium in patients in routine clinical conditions. The current study was designed to investigate the therapeutic efficacy of tiotropium delivered via the HandiHaler® device on the health status of patients with COPD with Global initiative for chronic Obstructive Lung Disease (GOLD) disease classification 2–4 in six central and eastern European countries in a real-life clinical setting. Methods The study was an open-label, prospective, uncontrolled, and single-arm surveillance study with three clinic visits during a 6-month observation period (baseline, and months 3 and 6). Health status was measured using the disease-specific St George’s Respiratory Questionnaire (SGRQ). The primary efficacy endpoint was the mean change from baseline in SGRQ total score at the end of the 6-month observational period. Results Patients treated with tiotropium 18 ?g once daily showed statistically significant and clinically meaningful reduction (improvement) of 21.7 units in the SGRQ total score, regardless of smoking status or cardiac comorbidities at enrollment (P < 0.0001). The analysis also showed that age, treatment compliance, and GOLD disease classification were significant factors that impact the health status of patients with COPD differently. Conclusion These results provide further support for the use of the tiotropium HandiHaler® as first-line maintenance treatment of patients with COPD with a clinician-assessed disease. PMID:24159258

  9. Femoral Component Rotation in Patellofemoral Joint Replacement: A Study Protocol for a Prospective Observational Study

    PubMed Central

    Westerbeek, Robin E; Derks, Rosalie P.H; Zonneveld, Bas J.G.L; van Jonbergen, Hans-Peter W.

    2015-01-01

    Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. The short and mid-term outcomes are related to malposition and unexplained pain. Whether external rotation of the femoral component in isolated patellofemoral joint replacement is required is unclear. The primary aim of this study is to determine the CT-measured femoral component rotation of patellofemoral joint replacement relative to the transepicondylar axis. The secondary aim is to correlate the CT-measured femoral component rotation with the clinical outcomes at 1-year follow-up as assessed with the KOOS questionnaire. We designed a prospective observational study with medical research ethics committee and institutional review board approval. A total of 40 patients who will be treated with patellofemoral joint replacement for isolated patellofemoral osteoarthritis will be included. Intra-operatively, rotation of the femoral component will be assessed using anatomical landmarks including the epicondylar axis, Whiteside’s line, and lower leg axis. The aim is to insert the femoral component between 3 and 6 degrees external rotation relative to the transepicondylar axis. Two experienced musculoskeletal radiologists will measure the angle between the transepicondylar axis and the femoral component, two to three days after surgery. The primary outcome is the CT-based femoral component rotation of the prosthesis relative to the transepicondylar axis. The secondary outcome is the patient reported KOOS questionnaire at 1-year follow-up. Successful completion of this study will provide data on the actual amount of femoral component rotation in patellofemoral joint replacement, and its relationship with clinical results. (Netherlands Trial Register NTR4175).

  10. The distinct surface of human blood dendritic cells, as observed after an improved isolation method.

    PubMed Central

    Freudenthal, P S; Steinman, R M

    1990-01-01

    Prior studies have identified a subset of dendritic cells in human blood, as well as their stimulatory function for T-cell-mediated immune responses. However research has been limited by difficulties in isolation, since dendritic cells make up only 0.1-1% of blood mononuclear cells. We present a protocol that reliably yields preparations that are greater than 80-90% pure. The method relies on the sequential depletion of the major cell types in blood and simultaneously provides T cells, monocytes, and B plus natural killer cells for comparison with dendritic cells. The last step in the procedure is the removal of residual contaminants on the basis of expression of a CD45R epitope. The enrichment of dendritic cells is evident by three criteria, each of which is related to the surface of these antigen-presenting cells. (i) All dendritic cells are motile, constantly forming large lamellipodia or veils. (ii) When analyzed with a large panel of monoclonal antibodies and the FACS, the cells express high levels of all known polymorphic major histocompatibility complex gene products, as well as a distinct combination of receptors and adhesion molecules. Unlike monocytes, for example, dendritic cells lack Fc receptors and the colony-stimulating factor 1 receptor (c-fms) but express much higher levels of ICAM-1 and LFA-3 adhesins. (iii) In functional assays, dendritic cells are at least 100 times more potent than monocytes or lymphocytes in stimulating the primary mixed leukocyte reaction. These properties help make the trace subset of dendritic cells more amenable to further functional and clinical studies. Images PMID:2145580

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

    USGS Publications Warehouse

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

    1991-01-01

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

  12. van Manen's method and reduction in a phenomenological hermeneutic study.

    PubMed

    Heinonen, Kristiina

    2015-03-01

    Aim To describe van Manen's method and concept of reduction in a study that used a phenomenological hermeneutic approach. Background Nurse researchers have used van Manen's method in different ways. Participants' lifeworlds are described in depth, but descriptions of reduction have been brief. Data sources The literature and knowledge review and manual search of research articles. Review methods Databases Web Science, PubMed, CINAHL and PsycINFO, without applying a time period, to identify uses of van Manen's method. Discussion This paper shows how van Manen's method has been used in nursing research and gives some examples of van Manen's reduction. Conclusion Reduction enables us to conduct in-depth phenomenological hermeneutic research and understand people's lifeworlds. Implications for research/practice As there are many variations in adapting reduction, it is complex and confusing. This paper contributes to the discussion of phenomenology, hermeneutic study and reduction. It opens up reduction as a method for researchers to exploit. PMID:25783151

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  14. Method performance study of the determination of total nitrogen in soy sauce by the Kjeldahl method.

    PubMed

    Nozawa, Shintaro; Hakoda, Akiko; Sakaida, Kenichi; Suzuki, Tadanao; Yasui, Akemi

    2005-09-01

    The objective of this collaborative study was to evaluate the proposed method for determining the total nitrogen in soy sauce by the Kjeldahl method submitted to the Codex Alimentarius Commission for endorsement in accordance with the protocol for the design, conduct, and interpretation of method-performance studies. The digestive conditions of the proposed method are the addition of 10 mL of H2SO4, 10 g (8 g by using a block digester) of K2SO4, and 1 mL of 20% CuSO4 x 5H2O and 80 min boiling period after the liquid is cleared by a heating device. Seventeen laboratories participated, analyzing five soy sauce samples as blind duplicates. Since the volume sampling method used in the JAS (Japanese Agricultural Standard) method showed lower accuracy of data because of the density of soy sauce, the method of sampling by weight was adopted as the proposed method. The total amount of outlier data was within acceptable limits for method-performance studies (< or = 22.2%). Lysine and ammonium sulfate recoveries for all laboratories were > or = 98% and > or = 99% respectively. The RSDr (repeatability relative standard deviation) values ranged from 0.4 to 1.3%, and the RSDR (reproducibility relative standard deviation) values were from 0.8 to 1.9%. HORRAT (RSDR/predicted RSDR) for the reproducibility showed 0.2 to 0.4, indicating acceptable precision of the method and excellent analytical performance. PMID:16363486

  15. Field observations and theoretical studies relevant to enhanced in situ carbonation

    E-print Network

    Field observations and theoretical studies relevant to enhanced in situ carbonation of peridotite observations and theoretical studies relevant to enhanced in situ carbonation of peridotite Peter B. Kelemen, USA 10964 ABSTRACT ­ Veins formed by carbonation of peridotite in the large thrust sheet of mantle

  16. An observational study of children interacting with an augmented story book

    E-print Network

    Hornecker, Eva

    An observational study of children interacting with an augmented story book Andreas Dünser1 , Eva books. Children aged between 6 and 7 read and interacted with one of two story books aimed at early findings of an observational study investigating how young children interact with augmented reality story

  17. Methodical questions and accuracy problems of GPS observations by the example of the geodynamic proving ground in Bishkek

    NASA Astrophysics Data System (ADS)

    Kuzikov, S. I.

    2014-11-01

    The key questions concerning the modern methodical tasks and accuracy of GPS measurements of crustal motion spanning are discussed for a full cycle of the survey from the organization of the field operations to the interpretation of the final results. The presented data rely on the 20-year experience of the geophysicists of the Research Station of the Russian Academy of Sciences in Bishkek (RS RAS) in GPS monitoring at the Geodynamic Proving Ground in Bishkek (GPGB) and in a large part of Central Asia. The comparative characteristics of the constellations of visible GPS and GLONASS satellites are analyzed from the standpoint of their practical application for precise scientific observations of crustal motions. The studies of the contemporary movements of the Earth's crust by the methods of satellite geodesy generally comprise three stages: (1) organization of the measurement networks and acquisition of the data; (2) data processing; and (3) interpretation of the results. Each stage is associated with its own block of the tasks and problems, and neither is guaranteed against uncertainties and errors which may affect the results, conclusions, and reconstructions.

  18. Current mathematical methods used in QSAR/QSPR studies.

    PubMed

    Liu, Peixun; Long, Wei

    2009-05-01

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

  19. Mixed methods research design for pragmatic psychoanalytic studies.

    PubMed

    Tillman, Jane G; Clemence, A Jill; Stevens, Jennifer L

    2011-10-01

    Calls for more rigorous psychoanalytic studies have increased over the past decade. The field has been divided by those who assert that psychoanalysis is properly a hermeneutic endeavor and those who see it as a science. A comparable debate is found in research methodology, where qualitative and quantitative methods have often been seen as occupying orthogonal positions. Recently, Mixed Methods Research (MMR) has emerged as a viable "third community" of research, pursuing a pragmatic approach to research endeavors through integrating qualitative and quantitative procedures in a single study design. Mixed Methods Research designs and the terminology associated with this emerging approach are explained, after which the methodology is explored as a potential integrative approach to a psychoanalytic human science. Both qualitative and quantitative research methods are reviewed, as well as how they may be used in Mixed Methods Research to study complex human phenomena. PMID:21880844

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  1. Horizontal flow fields observed in Hinode G-band images. I. Methods

    NASA Astrophysics Data System (ADS)

    Verma, M.; Denker, C.

    2011-05-01

    Context. The interaction of plasma motions and magnetic fields is an important mechanism, which drives the solar activity in all its facets. For example, photospheric flows are responsible for the advection of magnetic flux, the redistribution of flux during the decay of sunspots, and the build-up of magnetic shear in flaring active regions. Aims: Systematic studies based on G-band data from the Japanese Hinode mission provide the means to gather statistical properties of horizontal flow fields. This facilitates comparative studies of solar features, e.g., G-band bright points, magnetic knots, pores, and sunspots at various stages of evolution and in distinct magnetic environments, which advances our understanding of the dynamic Sun. Methods: We adapted local correlation tracking (LCT) to measure horizontal flow fields based on G-band images obtained with the Solar Optical Telescope on board Hinode. A total of about 200 time-series with a duration between 1-16 h and a cadence between 15-90 s were analyzed. Selecting a high-cadence (?t = 15 s) as well as a long-duration (?T = 16 h) time-series enabled us to optimize and validate the LCT input parameters, which ensures a robust, reliable, uniform, and accurate processing of a huge data volume. Results: The LCT algorithm produces best results for G-band images with a cadence of 60-90 s. If the cadence is lower, the velocity of slowly moving features will not be reliably detected. If the cadence is higher, the scene on the Sun will have evolved too much to bear any resemblance with the earlier situation. Consequently, in both instances horizontal proper motions are underestimated. The most reliable and yet detailed flow maps are produced using a Gaussian kernel with a size of 2560 km × 2560 km and a full-width-at-half-maximum (FWHM) of 1200 km (corresponding to the size of a typical granule) as sampling window. Conclusions: Horizontal flow maps and graphics for visualizing the properties of photospheric flow fields are typical examples for value-added data products, which can be extracted from solar databases. The results of this study will be made available within the "small projects" section of the German Astrophysical Virtual Observatory (GAVO).

  2. Ferritin levels and risk of metabolic syndrome: meta-analysis of observational studies

    PubMed Central

    2014-01-01

    Background Elevated ferritin levels have been associated with single cardiovascular risk factors but the relationship to the presence of metabolic syndrome is inconclusive. The aim of this systematic review and meta-analysis of published observational studies was to estimate the association between serum ferritin levels and metabolic syndrome in adults. Methods The Pubmed, SCOPUS and the Cochrane Library databases were searched for epidemiological studies that assessed the association between ferritin levels and metabolic syndrome and were published before September 2013. There were no language restrictions. Two investigators independently selected eligible studies. Measures of association were pooled by using an inverse-variance weighted random-effects model. The heterogeneity among studies was examined using the I2 index. Publication bias was evaluated using the funnel plot. Results Twelve cross-sectional, one case–control and two prospective studies met our inclusion criteria including data from a total of 56,053 participants. The pooled odds ratio (OR) for the metabolic syndrome comparing the highest and lowest category of ferritin levels was 1.73 (95% CI: 1.54, 1.95; I2?= 75,4%). Subgroup analyses indicate that pooled OR was 1.92 (95% CI: 1.61, 2.30; I2?= 78%) for studies adjusting for C-reactive protein (CRP), and 1.52 (95% CI:1. 36, 1.69; I2?=?41%) for studies that did not adjust for CRP (P?=?0.044). This finding was remarkably robust in the sensitivity analysis. We did not find publication bias. Conclusions The meta-analysis suggests that increased ferritin levels are independently and positively associated with the presence of the metabolic syndrome with an odds ratio higher than 1.73. PMID:24884526

  3. Robust methods for population stratification in genome wide association studies

    PubMed Central

    2013-01-01

    Background Genome-wide association studies can provide novel insights into diseases of interest, as well as to the responsiveness of an individual to specific treatments. In such studies, it is very important to correct for population stratification, which refers to allele frequency differences between cases and controls due to systematic ancestry differences. Population stratification can cause spurious associations if not adjusted properly. The principal component analysis (PCA) method has been relied upon as a highly useful methodology to adjust for population stratification in these types of large-scale studies. Recently, the linear mixed model (LMM) has also been proposed to account for family structure or cryptic relatedness. However, neither of these approaches may be optimal in properly correcting for sample structures in the presence of subject outliers. Results We propose to use robust PCA combined with k-medoids clustering to deal with population stratification. This approach can adjust for population stratification for both continuous and discrete populations with subject outliers, and it can be considered as an extension of the PCA method and the multidimensional scaling (MDS) method. Through simulation studies, we compare the performance of our proposed methods with several widely used stratification methods, including PCA and MDS. We show that subject outliers can greatly influence the analysis results from several existing methods, while our proposed robust population stratification methods perform very well for both discrete and admixed populations with subject outliers. We illustrate the new method using data from a rheumatoid arthritis study. Conclusions We demonstrate that subject outliers can greatly influence the analysis result in GWA studies, and propose robust methods for dealing with population stratification that outperform existing population stratification methods in the presence of subject outliers. PMID:23601181

  4. Long-term effectiveness of intralesional triamcinolone acetonide therapy in orofacial granulomatosis: an observational cohort study

    PubMed Central

    Fedele, S; Fung, PPL; Bamashmous, N; Petrie, A; Porter, S

    2014-01-01

    Summary Background It has been suggested that intralesional triamcinolone injections represent a safe and effective therapeutic strategy in controlling the permanent disfiguring swelling of orofacial granulomatosis (OFG). However, robust supporting evidence is lacking, due to the variable and inconsistent design of available studies. Objectives To investigate whether a standardized regimen of intralesional triamcinolone has beneficial long-term effects on orofacial swelling of OFG. We also studied potential associations with a number of prognostic factors. Methods We designed a retrospective observational study of a homogeneous cohort of 22 well-phenotyped patients with OFG. The primary outcome was defined as a statistically significant decrease in post-treatment disease severity. Statistically significant association with prognostic factors was the secondary outcome. Statistical analysis included Wilcoxon signed-rank tests and logistic regression. Results Compared with pretreatment, there were statistically significant decreases in disease severity scores at all time points until 48 months post-treatment (P < 0·01). Logistic regression analysis showed there was no independent prognostic variable of statistical significance (P > 0·05). The majority of patients (14/22, 63·6%) received one course of intralesional triamcinolone and did not experience disease recurrence. The mean disease-free period after the first course of intralesional therapy was 28·9 ± 18 months (95% confidence interval 28·7–29·1). No adverse effects were reported. Conclusions This is the first study to have employed robust cohort methodology and sound statistics to demonstrate long-term effectiveness of intralesional triamcinolone in controlling the disfiguring swelling of OFG. Because of limitations inherent in observational studies, further research in the form of randomized case-control trials is needed to confirm the present findings. What's already known about this topic? It has been suggested that intralesional corticosteroid therapy is effective in controlling the permanent disfiguring swelling of orofacial granulomatosis (OFG); however, robust supporting evidence is lacking due to the variable and inconsistent design of available studies. What does this study add? This is the first cohort study on intralesional therapy to employ robust cohort design, consistent methodology and a standardized regimen of triamcinolone injections. It provides reliable evidence of long-term effectiveness in reducing the orofacial swelling of OFG. PMID:24088036

  5. Culture method to study fungal growth in solid fermentation

    Microsoft Academic Search

    Maurice Raimbault; Didier Alazard

    1980-01-01

    A new culture method is described to study the growth of Aspergillus niger on cassava meal in the solid state. This method uses preparations of the cooked starchy substrate as a homogeneous granulated product containing spores, salts and water. An incubation device aerates the mass with humidified air at a controlled temperature. Homogeneous development of mycelia, without sporulation, occurred in

  6. Engineering Study of 500 ML Sample Bottle Transportation Methods

    SciTech Connect

    BOGER, R.M.

    1999-08-25

    This engineering study reviews and evaluates all available methods for transportation of 500-mL grab sample bottles, reviews and evaluates transportation requirements and schedules and analyzes and recommends the most cost-effective method for transporting 500-mL grab sample bottles.

  7. Mixed Methods Research Design for Pragmatic Psychoanalytic Studies

    Microsoft Academic Search

    Jane G. Tillman; A. Jill Clemence; Jennifer L. Stevens

    2011-01-01

    Calls for more rigorous psychoanalytic studies have increased over the past decade. The field has been divided by those who assert that psychoanalysis is properly a hermeneutic endeavor and those who see it as a science. A comparable debate is found in research methodology, where qualitative and quantitative methods have often been seen as occupying orthogonal positions. Recently, Mixed Methods

  8. Qualitative Methods for Studying Distributed Software Development: Issues and Challenges

    E-print Network

    Patil, Sameer

    the begin- ning stages of my doctoral studies via a formal course on qualitative research methods as well. Subsequently, I have applied the knowl- edge and insights by incorporating qualitative methods in my research approach by using both qualitative and quantitative approaches in complemen- tary ways (see e

  9. A Study of Methods for Estimating Distributions of Test Scores.

    ERIC Educational Resources Information Center

    Cope, Ronald T.; Kolen, Michael J.

    This study compared five density estimation techniques applied to samples from a population of 272,244 examinees' ACT English Usage and Mathematics Usage raw scores. Unsmoothed frequencies, kernel method, negative hypergeometric, four-parameter beta compound binomial, and Cureton-Tukey methods were applied to 500 replications of random samples of…

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

    EPA Science Inventory

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

  11. Mixed methods studies in entrepreneurship research: Applications and contributions

    Microsoft Academic Search

    José F. Molina-Azorín; María D. López-Gamero; Jorge Pereira-Moliner; Eva M. Pertusa-Ortega

    2012-01-01

    Mixed methods research is becoming an increasingly popular approach in several fields. However, its application in the field of entrepreneurship has not been studied. The authors reviewed the use of mixed methods research in three entrepreneurship journals and two leading generalistic journals that publish entrepreneurship research, examining the main purposes and designs. A total of 955 articles were reviewed and

  12. Mixed methods studies in entrepreneurship research: Applications and contributions

    Microsoft Academic Search

    José F. Molina-Azorín; María D. López-Gamero; Jorge Pereira-Moliner; Eva M. Pertusa-Ortega

    2011-01-01

    Mixed methods research is becoming an increasingly popular approach in several fields. However, its application in the field of entrepreneurship has not been studied. The authors reviewed the use of mixed methods research in three entrepreneurship journals and two leading generalistic journals that publish entrepreneurship research, examining the main purposes and designs. A total of 955 articles were reviewed and

  13. Three Strategies for Teaching Research Methods: A Case Study

    ERIC Educational Resources Information Center

    Pfeffer, Carla A.; Rogalin, Christabel L.

    2012-01-01

    The authors provide a brief case study of a three-strategy approach for teaching undergraduate research methods that (1) incorporates active learning assignments and discussion-based learning, (2) integrates a cross-discipline and cross-method faculty guest discussion facilitators series, and (3) focuses on the challenges and rewards of conducting…

  14. Development of a test machine and method for galling studies

    Microsoft Academic Search

    A. Ertas; H. J. Carper; W. R. Blackstone

    1992-01-01

    A test method for evaluating galling resistance in tubular connections by using the established evaluation technique known as the up and down or Bruceton method was studied. A unique test machine that would closely simulate the actual field conditions was designed and constructed. By using the Taguchi technique, the relative effects of rotational speed, roughness, and axial load on the

  15. RESEARCH PLAN AND METHODS MANUAL FOR THE OREGON WETLANDS STUDY

    EPA Science Inventory

    The goals of the Oregon Wetlands Study are to develop a monitoring method for characterizing and comparing natural and project freshwater, emergent wetlands in different land use settings, and to obtain information that will improve wetland management strategies employing restora...

  16. A Multiple-Scan Focusing Method for Radio Frequency Bulk Acoustic Wave Device Observation by Laser Probe System

    NASA Astrophysics Data System (ADS)

    Nan Wu,; Ken-ya Hashimoto,; Tatsuya Omori,; Masatsune Yamaguchi,

    2010-07-01

    This paper proposes a focusing method based on multiple scanning of a device surface to be observed, which is particularly-suitable for a fast-mechanical-scanning and phase-sensitive laser probe for radio frequency (RF) surface and bulk acoustic wave (SAW/BAW) devices. When high spatial resolution is required for the observation, one needs an objective lens of large magnifying power with extremely shallow focal depth. Accordingly, an uneven surface and tiny inclination of a BAW device cause acquired images a considerable defocus, by which it is difficult to obtain precise and reliable field quantities related to acoustic waves in the device. The proposed method is shown to be most effective in avoiding this sort of defocus and able to focus the entire surface. By this method, for example, we could clearly observe power leakage in an FBAR structure.

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

    E-print Network

    Watson, Warren Wallace

    1960-01-01

    problem. As a general rule the simplex and revised simplex procedures are best suited for application on high speed digital compdters. A large variety of problems has been solved by linear program- ming methods; however, s, number of problems which...A STUDY OF LINEAR PROGRAMMING AND METHODS FOR PROGRAMMING THE SIMPLEX METHOD A Thesis By Warren W. Watson Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements...

  18. On the choice of acceptance radius in free-response observer performance studies

    PubMed Central

    Haygood, T M; Ryan, J; Brennan, P C; Li, S; Marom, E M; McEntee, M F; Itani, M; Evanoff, M; Chakraborty, D

    2013-01-01

    Objectives Choosing an acceptance radius or proximity criterion is necessary to analyse free-response receiver operating characteristic (FROC) observer performance data. This is currently subjective, with little guidance in the literature about what is an appropriate acceptance radius. We evaluated varying acceptance radii in a nodule detection task in chest radiography and suggest guidelines for determining an acceptance radius. Methods 80 chest radiographs were chosen, half of which contained nodules. We determined each nodule's centre. 21 radiologists read the images. We created acceptance radii bins of <5 pixels, <10 pixels, <20 pixels and onwards up to <200 and 200+ pixels. We counted lesion localisations in each bin and visually compared marks with the borders of nodules. Results Most reader marks were tightly clustered around nodule centres, with tighter clustering for smaller than for larger nodules. At least 70% of readers' marks were placed within <10 pixels for small nodules, <20 pixels for medium nodules and <30 pixels for large nodules. Of 72 inspected marks that were less than 50 pixels from the centre of a nodule, only 1 fell outside the border of a nodule. Conclusion The acceptance radius should be based on the larger nodule sizes. For our data, an acceptance radius of 50 pixels would have captured all but 2 reader marks within the borders of a nodule, while excluding only 1 true-positive mark. The choice of an acceptance radius for FROC analysis of observer performance studies should be based on the size of larger abnormalities. PMID:22573302

  19. [Preliminary study on detox in outpatient care units with 18 alcoholic patients in Directly Observed Treatment].

    PubMed

    Lloréns Martínez, Ramón; Calatayud Francés, María; Morales Gallús, Esperanza; Añó Cervera, Consol; Adriá Caballero, Librada

    2008-01-01

    Directly Observed Treatment (TOD-DOT) has been tested in different conditions. The objective of this work is to check whether a UCA-CAB (Centre for Addictive Behaviour) can achieve detox and reduce the risk of early relapse (up to 12 weeks) in alcoholic patients. All patients had an established organic addiction and serious withdrawal syndrome, and had undergone multiple previous treatments. Furthermore, they had not managed to abstain for a 3-month consecutive period over the previous 2 years. The aim of the Directly Observed Treatment was to attain detox and reduce relapse by following a multi-method approach: medical, psychological and personal care, based on a brief daily consultation and pharmacological supervision. The results were as follows: Of the 18 patients included in the study, after 12 weeks, 13 (72 %) were still abstinent and 4 (22 %) had relapsed. Thus, 17 (94 %) were still following the treatment, with just one drop-out. We analysed the profiles of the patients abstaining, of those who relapsed (4) and of the one who dropped out. The average CIWA-Ar was 27.05 (21-36). Any value over 20 is considered to indicate serious withdrawal syndrome, though there were no negative events leading to hospitalization. Level of adherence to the treatment (94 %) meant that the most seriously affected patients and those with fewest financial resources could benefit, not only from any auxiliary social schemes, but also from basic health services, permitting them to improve the quality of their everyday life. PMID:18813775

  20. An observational study of sun and heat protection during Canada Day outdoor celebration, 2003.

    PubMed

    David, S T; Chandran, U; Paquette, D; Scholten, D; Wilson, J; Galanis, E; Becker, M; Crane, F; Lester, R; Mersereau, T; Wong, E; Carr, D

    2005-01-01

    Attendance at summer outdoor mass gatherings may lead to heat- and sun-related illness. The purposes of this study were: (1) to estimate the proportion of people in attendance at the 2003 Canada Day celebration in the National Capital Region who used sun and heat protective items; (2) to identify factors associated with the utilization of these protective items; and (3) to provide research data to public outdoor event organizers when developing evidence-based plans for safer events. A naturalistic observational cross-sectional method was used to gather information at the 2003 Canada Day celebration in the National Capital Region on attendees' demographics, the sun and heat protective items they used and the protective resources available at the event sites. Of the 398 observed attendees, the proportion using any one of the protective items ranged from 3 percent (an open umbrella) to 51.5 percent (sunglasses). Females were more likely to use protective items more than males, and adults more likely than children. Planners of public outdoor events should consider the factors that influence the utilization of sun and heat protective behaviours and the environmental modifications that would allow participants to make safe choices. PMID:16251011