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Sample records for observational study time

  1. The survival time of chocolates on hospital wards: covert observational study.

    PubMed

    Gajendragadkar, Parag R; Moualed, Daniel J; Nicolson, Phillip L R; Adjei, Felicia D; Cakebread, Holly E; Duehmke, Rudolf M; Martin, Claire A

    2013-12-14

    To quantify the consumption of chocolates in a hospital ward environment. Multicentre, prospective, covert observational study. Four wards at three hospitals (where the authors worked) within the United Kingdom. Boxes of Quality Street (Nestlé) and Roses (Cadbury) on the ward and anyone eating these chocolates. Observers covertly placed two 350 g boxes of Quality Street and Roses chocolates on each ward (eight boxes were used in the study containing a total of 258 individual chocolates). These boxes were kept under continuous covert surveillance, with the time recorded when each chocolate was eaten. Median survival time of a chocolate. 191 out of 258 (74%) chocolates were observed being eaten. The mean total observation period was 254 minutes (95% confidence interval 179 to 329). The median survival time of a chocolate was 51 minutes (39 to 63). The model of chocolate consumption was non-linear, with an initial rapid rate of consumption that slowed with time. An exponential decay model best fitted these findings (model R(2)=0.844, P<0.001), with a survival half life (time taken for 50% of the chocolates to be eaten) of 99 minutes. The mean time taken to open a box of chocolates from first appearance on the ward was 12 minutes (95% confidence interval 0 to 24). Quality Street chocolates survived longer than Roses chocolates (hazard ratio for survival of Roses v Quality Street 0.70, 95% confidence interval 0.53 to 0.93, P=0.014). The highest percentages of chocolates were consumed by healthcare assistants (28%) and nurses (28%), followed by doctors (15%). From our observational study, chocolate survival in a hospital ward was relatively short, and was modelled well by an exponential decay model. Roses chocolates were preferentially consumed to Quality Street chocolates in a ward setting. Chocolates were consumed primarily by healthcare assistants and nurses, followed by doctors. Further practical studies are needed.

  2. The survival time of chocolates on hospital wards: covert observational study

    PubMed Central

    Moualed, Daniel J; Nicolson, Phillip L R; Adjei, Felicia D; Cakebread, Holly E; Duehmke, Rudolf M; Martin, Claire A

    2013-01-01

    Objective To quantify the consumption of chocolates in a hospital ward environment. Design Multicentre, prospective, covert observational study. Setting Four wards at three hospitals (where the authors worked) within the United Kingdom. Participants Boxes of Quality Street (Nestlé) and Roses (Cadbury) on the ward and anyone eating these chocolates. Intervention Observers covertly placed two 350 g boxes of Quality Street and Roses chocolates on each ward (eight boxes were used in the study containing a total of 258 individual chocolates). These boxes were kept under continuous covert surveillance, with the time recorded when each chocolate was eaten. Main outcome measure Median survival time of a chocolate. Results 191 out of 258 (74%) chocolates were observed being eaten. The mean total observation period was 254 minutes (95% confidence interval 179 to 329). The median survival time of a chocolate was 51 minutes (39 to 63). The model of chocolate consumption was non-linear, with an initial rapid rate of consumption that slowed with time. An exponential decay model best fitted these findings (model R2=0.844, P<0.001), with a survival half life (time taken for 50% of the chocolates to be eaten) of 99 minutes. The mean time taken to open a box of chocolates from first appearance on the ward was 12 minutes (95% confidence interval 0 to 24). Quality Street chocolates survived longer than Roses chocolates (hazard ratio for survival of Roses v Quality Street 0.70, 95% confidence interval 0.53 to 0.93, P=0.014). The highest percentages of chocolates were consumed by healthcare assistants (28%) and nurses (28%), followed by doctors (15%). Conclusions From our observational study, chocolate survival in a hospital ward was relatively short, and was modelled well by an exponential decay model. Roses chocolates were preferentially consumed to Quality Street chocolates in a ward setting. Chocolates were consumed primarily by healthcare assistants and nurses, followed by doctors

  3. Study on in situ and real-time observation during process of SCN crystal growth

    NASA Astrophysics Data System (ADS)

    Lei, Songhe; Chen, Changle; Duan, Mengmeng

    2006-02-01

    Crystal growth is dynamic coupling of transportation process and growth process between interfaces. Convection during crystal growth will tend to changes of liquation component and the defect of impurity stripe. The convection and stability should further be studied to obtain the crystal of high quality. It is necessary to obtain surface configuration and distribution of temperature around liquation phase and solute concentration. The technique of in-situ and real-time observation is a brand new technique, which is widely applied to production and scientific research. Information of crystal growth will be obtained from the observation. But the in-situ and real-time observation is uncharitableness for the experiment equipment, some conditions matched to the character of crystal must be provided. In the paper a design with ingenious and cheap crystal growth cell and circulation system of constant-temperature water which is suitable for the experiment of observation is developed, and a combined light path based on the technique of flowing visualization is designed to match to the crystal cell. The combined light path which is made up of the schlieren method and the principle of Mach-zehnder interference is non destructive, high sensitivity and observable, so it is an effective method to study the crystal growth.

  4. Mandatory Nap Times and Group Napping Patterns in Child Care: An Observational Study.

    PubMed

    Staton, Sally L; Smith, Simon S; Hurst, Cameron; Pattinson, Cassandra L; Thorpe, Karen J

    2017-01-01

    Policy provision for naps is typical in child care settings, but there is variability in the practices employed. One practice that might modify children's early sleep patterns is the allocation of a mandatory nap time in which all children are required to lie on their beds without alternate activity permitted. There is currently limited evidence of the effects of such practices on children's napping patterns. This study examined the association between duration of mandatory nap times and group-level napping patterns in child care settings. Observations were undertaken in a community sample of 113 preschool rooms with a scheduled nap time (N = 2,114 children). Results showed that 83.5% of child care settings implemented a mandatory nap time (range = 15-145 min) while 14.2% provided alternate activities for children throughout the nap time period. Overall, 31% of children napped during nap times. Compared to rooms with ≤ 30 min of mandatory nap time, rooms with 31-60 min and > 60 min of mandatory nap time had a two-and-a-half and fourfold increase, respectively, in the proportion of children napping. Nap onset latency did not significantly differ across groups. Among preschool children, exposure to longer mandatory nap times in child care may increase incidence of napping.

  5. Time to publication for publicly funded clinical trials in Australia: an observational study

    PubMed Central

    Strand, Linn Beate; Clarke, Philip; Graves, Nicholas

    2017-01-01

    Objective To examine the length of time between receiving funding and publishing the protocol and main paper for randomised controlled trials. Design An observational study using survival analysis. Setting Publicly funded health and medical research in Australia. Participants Randomised controlled trials funded by the National Health and Medical Research Council of Australia between 2008 and 2010. Main outcome measures Time from funding to the protocol paper and main results paper. Multiple variable survival models examining whether study characteristics predicted publication times. Results We found 77 studies with a total funding of $A59 million. The median time to publication of the protocol paper was 6.4 years after funding (95% CI 4.1 to 8.1). The proportion with a published protocol paper 8 years after funding was 0.61 (95% CI 0.48 to 0.74). The median time to publication of the main results paper was 7.1 years after funding (95% CI 6.3 to 7.6). The proportion with a published main results paper 8 years after funding was 0.72 (95% CI 0.56 to 0.87). The HRs for how study characteristics might influence timing were generally close to one with narrow CIs, the notable exception was that a longer study length lengthened the time to the main paper (HR=0.62 per extra study year, 95% CI 0.43 to 0.89). Conclusions Despite the widespread registration of clinical trials, there remain serious concerns of trial results not being published or being published with a long delay. We have found that these same concerns apply to protocol papers, which should be publishable soon after funding. Funding agencies could set a target of publishing the protocol paper within 18 months of funding. PMID:28336734

  6. Immortal time bias in observational studies of drug effects in pregnancy.

    PubMed

    Matok, Ilan; Azoulay, Laurent; Yin, Hui; Suissa, Samy

    2014-09-01

    The use of decongestants during the second or third trimesters of pregnancy has been associated with a decreased risk of preterm delivery in two observational studies. This effect may have been subject to immortal time bias, a bias arising from the improper classification of exposure during follow-up. We illustrate this bias by repeating the studies using a different data source. The United Kingdom Hospital Episodes Statistics and the Clinical Practice Research Datalink databases were linked to identify all live singleton pregnancies among women aged 15 to 45 years between 1997 and 2012. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals of preterm delivery (before 37 weeks of gestation) by considering the use of decongestants during the third trimester as a time-fixed (biased analysis which misclassifies unexposed person-time as exposed person-time) and time-varying exposure (unbiased analysis with proper classification of unexposed person-time). All models were adjusted for maternal age, smoking status, maternal diabetes, maternal hypertension, preeclampsia, and parity. Of the 195,582 singleton deliveries, 10,248 (5.2%) were born preterm. In the time-fixed analysis, the HR of preterm delivery for the use of decongestants was below the null and suggestive of a 46% decreased risk (adjusted HR = 0.54; 95% confidence interval, 0.24-1.20). In contrast, the HR was closer to null (adjusted HR = 0.93 95% confidence interval, 0.42-2.06) when the use of decongestants was treated as a time-varying variable. Studies of drug safety in pregnancy should use the appropriate statistical techniques to avoid immortal time bias, particularly when the exposure occurs at later stages of pregnancy. © 2014 Wiley Periodicals, Inc.

  7. Observational study to determine predictors of rheumatology clinic visit provider contact time

    PubMed Central

    Davis, Lisa A.; Larson, Molly M.; Caplan, Liron

    2014-01-01

    Objective To address perceived inefficiencies in an academic rheumatology practice, a timing/work-flow evaluation was initiated to determine the factors that predict the Provider Contact Time (PCT)—the amount of time that attending physicians spend with patients during an outpatient encounter. Methods This prospective observational study was conducted at the University of Colorado Hospital rheumatology clinic for return patient visits in early 2008. Each patient encounter was subdivided into components and the time for each component was recorded. Up to 20 return visit encounters per provider were randomly selected for inclusion. Multivariate linear regression was used to predict the time, in minutes, that providers spend with patients and logistic regression was used to determine the time intervals associated with patients' perception that the visit ran on time. Results Variables associated with increased PCT were whether a procedure was performed in the clinic (p=0.037) and whether the visit occurred in the afternoon (p<0.025). For every minute a provider was late in beginning to see a patient, the PCT decreased by 0.32 minutes (C.I. 0.15-0.49). Variables associated with patient's perception that the visit ran on time include the Check In-To-Vital Delay (O.R. 0.95, C.I. 0.92-0.99) and the Provider Delay (O.R. 0.92, 95% CI 0.86-0.99). Conclusion Patients' punctuality and the presence of a resident were not significantly associated with the time that a provider spent with a patient. However, the degree to which the provider ran late was associated with decreased PCT and diminished the patient's perception that the visit ran on time. PMID:20583104

  8. Fibromyalgia Outcomes Over Time: Results from a Prospective Observational Study in the United States

    PubMed Central

    Schaefer, Caroline P.; Adams, Edgar H.; Udall, Margarita; Masters, Elizabeth T.; Mann, Rachael M.; Daniel, Shoshana R.; McElroy, Heather J.; Cappelleri, Joseph C.; Clair, Andrew G.; Hopps, Markay; Staud, Roland; Mease, Philip; Silverman, Stuart L.

    2016-01-01

    Background: Longitudinal research on outcomes of patients with fibromyalgia is limited. Objective: To assess clinician and patient-reported outcomes over time among fibromyalgia patients. Methods: At enrollment (Baseline) and follow-up (approximately 2 years later), consented patients were screened for chronic widespread pain (CWP), attended a physician site visit to determine fibromyalgia status, and completed an online questionnaire assessing pain, sleep, function, health status, productivity, medications, and healthcare resource use. Results: Seventy-six fibromyalgia patients participated at both time points (at Baseline: 86.8% white, 89.5% female, mean age 50.9 years, and mean duration of fibromyalgia 4.1 years). Mean number of tender points at each physician visit was 14.1 and 13.5, respectively; 11 patients no longer screened positive for CWP at follow-up. A majority reported medication use for pain (59.2% at Baseline, 62.0% at Follow-up). The most common medication classes were opioids (32.4%), SSRIs (16.9%), and tramadol (14.1%) at Follow-up. Significant mean changes over time were observed for fibromyalgia symptoms (modified American College of Rheumatology 2010 criteria: 18.4 to 16.9; P=0.004), pain interference with function (Brief Pain Inventory-Short Form: 5.9 to 5.3; P=0.013), and sleep (Medical Outcomes Study-Sleep Scale: 58.3 to 52.7; P=0.004). Patients achieving ≥2 point improvement in pain (14.5%) experienced greater changes in pain interference with function (6.8 to 3.4; P=0.001) and sleep (62.4 to 51.0; P=0.061). Conclusion: Fibromyalgia patients reported high levels of burden at both time points, with few significant changes observed over time. Outcomes were variable among patients over time and were better among those with greater pain improvement. PMID:28077978

  9. Fibromyalgia Outcomes Over Time: Results from a Prospective Observational Study in the United States.

    PubMed

    Schaefer, Caroline P; Adams, Edgar H; Udall, Margarita; Masters, Elizabeth T; Mann, Rachael M; Daniel, Shoshana R; McElroy, Heather J; Cappelleri, Joseph C; Clair, Andrew G; Hopps, Markay; Staud, Roland; Mease, Philip; Silverman, Stuart L

    2016-01-01

    Longitudinal research on outcomes of patients with fibromyalgia is limited. To assess clinician and patient-reported outcomes over time among fibromyalgia patients. At enrollment (Baseline) and follow-up (approximately 2 years later), consented patients were screened for chronic widespread pain (CWP), attended a physician site visit to determine fibromyalgia status, and completed an online questionnaire assessing pain, sleep, function, health status, productivity, medications, and healthcare resource use. Seventy-six fibromyalgia patients participated at both time points (at Baseline: 86.8% white, 89.5% female, mean age 50.9 years, and mean duration of fibromyalgia 4.1 years). Mean number of tender points at each physician visit was 14.1 and 13.5, respectively; 11 patients no longer screened positive for CWP at follow-up. A majority reported medication use for pain (59.2% at Baseline, 62.0% at Follow-up). The most common medication classes were opioids (32.4%), SSRIs (16.9%), and tramadol (14.1%) at Follow-up. Significant mean changes over time were observed for fibromyalgia symptoms (modified American College of Rheumatology 2010 criteria: 18.4 to 16.9; P=0.004), pain interference with function (Brief Pain Inventory-Short Form: 5.9 to 5.3; P=0.013), and sleep (Medical Outcomes Study-Sleep Scale: 58.3 to 52.7; P=0.004). Patients achieving ≥2 point improvement in pain (14.5%) experienced greater changes in pain interference with function (6.8 to 3.4; P=0.001) and sleep (62.4 to 51.0; P=0.061). Fibromyalgia patients reported high levels of burden at both time points, with few significant changes observed over time. Outcomes were variable among patients over time and were better among those with greater pain improvement.

  10. Platelet function in reconstituted whole blood variants: An observational study over 5 days of storage time.

    PubMed

    Ponschab, Martin; Schlimp, Christoph J; Zipperle, Johannes; Gabriel, Christian; Süssner, Susanne; Cadamuro, Janne; Gratz, Johannes; Redl, Heinz; Schöchl, Herbert

    2015-11-01

    Platelet concentrates (PCs) are usually stored at room temperature under constant gentle agitation. Risk of bacterial contamination limits maximum storage time to 5 days. The objective of the study was to investigate platelet function with regard to storage time in different reconstituted whole blood (RWB) variants. Donated apheresis PCs were stored at 22°C over 5 days. To obtain RWB, apheresis PCs were mixed with plasma-free packed red blood cells (RBCs) and either prethawed fresh frozen plasma (PT) or solvent-detergent plasma (SD) [1:1:1 ratio], or with leukocyte- and platelet-depleted whole blood (LD-WB) as control. Platelet function in RWB variants was assessed by impedance aggregometry (Multiplate) on Days 0, 1, 3, and 5 following platelet donation. Platelet aggregometry did not reach the lower limits determined from healthy volunteers in any of the RWB variants. Platelet aggregability measured by ASPI test, ADP test, and COL test declined over storage time in all RWB variants. No differences were observed in the TRAP test. At most measurement time points, LD-RWB provided significantly higher platelet aggregability compared with SD-RWB and PT-RWB (p < 0.01). SD-RWB demonstrated higher platelet aggregability on Day 0 in the ASPI test, ADP test, and TRAP test compared with PT-RWB. Apheresis PCs stored for 5 days at 22°C demonstrated reduced platelet aggregability, as measured by multiple electrode aggregometry when mixed with RBCs and plasma. As platelet aggregation in LD-RWB was superior compared with SD-RWB and PT-RWB variants, it might be possible that additives in RBCs or plasma are responsible for the observed depressed platelet function. Critical evaluation of current massive transfusion recommendations proposing early platelet transfusion is indicated.

  11. Real-Time Ultrasound-Guided Spinal Anaesthesia: A Prospective Observational Study of a New Approach

    PubMed Central

    Conroy, P. H.; Luyet, C.; McCartney, C. J.; McHardy, P. G.

    2013-01-01

    Identification of the subarachnoid space has traditionally been achieved by either a blind landmark-guided approach or using prepuncture ultrasound assistance. To assess the feasibility of performing spinal anaesthesia under real-time ultrasound guidance in routine clinical practice we conducted a single center prospective observational study among patients undergoing lower limb orthopaedic surgery. A spinal needle was inserted unassisted within the ultrasound transducer imaging plane using a paramedian approach (i.e., the operator held the transducer in one hand and the spinal needle in the other). The primary outcome measure was the success rate of CSF acquisition under real-time ultrasound guidance with CSF being located in 97 out of 100 consecutive patients within median three needle passes (IQR 1–6). CSF was not acquired in three patients. Subsequent attempts combining landmark palpation and pre-puncture ultrasound scanning resulted in successful spinal anaesthesia in two of these patients with the third patient requiring general anaesthesia. Median time from spinal needle insertion until intrathecal injection completion was 1.2 minutes (IQR 0.83–4.1) demonstrating the feasibility of this technique in routine clinical practice. PMID:23365568

  12. Fire Engine Support and On-scene Time in Prehospital Stroke Care - A Prospective Observational Study.

    PubMed

    Puolakka, Tuukka; Väyrynen, Taneli; Erkkilä, Elja-Pekka; Kuisma, Markku

    2016-06-01

    Introduction On-scene time (OST) previously has been shown to be a significant component of Emergency Medical Services' (EMS') operational delay in acute stroke. Since stroke patients are managed routinely by two-person ambulance crews, increasing the number of personnel available on the scene is a possible method to improve their performance. Hypothesis Using fire engine crews to support ambulances on the scene in acute stroke is hypothesized to be associated with a shorter OST. All patients transported to hospital as thrombolysis candidates during a one-year study period were registered by the ambulance crews using a case report form that included patient characteristics and operational EMS data. Seventy-seven patients (41 [53%] male; mean age of 68.9 years [SD=15]; mean Glasgow Coma Score [GCS] of 15 points [IQR=14-15]) were eligible for the study. Forty-five cases were managed by ambulance and fire engine crews together and 32 by the ambulance crews alone. The median ambulance response time was seven minutes (IQR=5-10) and the fire engine response time was six minutes (IQR=5-8). The number of EMS personnel on the scene was six (IQR=5-7) and two (IQR=2-2), and the OST was 21 minutes (IQR=18-26) and 24 minutes (IQR=20-32; P =.073) for the groups, respectively. In a following regression analysis, using stroke as the dispatch code was the only variable associated with short (<22 minutes) OST with an odds ratio of 3.952 (95% CI, 1.279-12.207). Dispatching fire engine crews to support ambulances in acute stroke care was not associated with a shorter on-scene stay when compared to standard management by two-person ambulance crews alone. Using stroke as the dispatch code was the only variable that was associated independently with a short OST. Puolakka T , Väyrynen T , Erkkilä E-P , Kuisma M . Fire engine support and on-scene time in prehospital stroke care - a prospective observational study. Prehosp Disaster Med. 2016;31(3):278-281.

  13. Immortal time bias in critical care research: application of time-varying Cox regression for observational cohort studies.

    PubMed

    Shintani, Ayumi K; Girard, Timothy D; Eden, Svetlana K; Arbogast, Patrick G; Moons, Karel G M; Ely, E Wesley

    2009-11-01

    To examine the bias introduced by using time-fixed methodology to analyze the effects of a time-varying exposure incurred in the intensive care unit. Prospective cohort and Monte Carlo simulation studies. Medical and coronary intensive care units in a university hospital. A total of 224 mechanically ventilated patients. Part I was a case study analyzing the association between delirium in the intensive care unit (exposure variable) and outcomes (intensive care unit length of stay and 6-mo mortality) in a prospective cohort study. Part II was a Monte Carlo simulation generating 16,000 data sets wherein the true associations between delirium and outcomes were known before analysis. In both parts, we assessed associations between delirium in the intensive care unit and outcomes (intensive care unit length of stay and mortality), using time-fixed vs. time-varying Cox regression methodology. In the case study, delirium analyzed as a time-fixed variable was associated with a delayed intensive care unit discharge (adjusted hazard ratio = 1.9, 95% confidence interval, 1.3-2.7, p < .001), but no association was noted using a time-varying method (adjusted hazard ratio = 1.1, 95% confidence interval = 0.7-1.6, p = .70). Alternatively, delirium analyzed as a time-fixed variable was not associated with 6-mo mortality (adjusted hazard ratio = 2.9, 95% confidence interval, 0.9-5.0, p = .09), whereas delirium analyzed as a time-varying variable was associated with increased mortality (adjusted hazard ratio = 3.2, 95% confidence interval, 1.4-7.7, p = .008). In the simulation study, time-fixed methods produced erroneous results in 97.1% of the data sets with no true association; time-varying methods produced erroneous results in only 3.7%. Similarly, time-fixed methods produced biased results when a true association was present, whereas time-varying methods produced accurate results. Studies using a time-fixed analytic approach to understand relationships between exposures and

  14. [Registration of observational studies: it is time to comply with the Declaration of Helsinki requirement].

    PubMed

    Dal-Ré, Rafael; Delgado, Miguel; Bolumar, Francisco

    2015-01-01

    Publication bias is a serious deficiency in the current system of disseminating the results of human research studies. Clinical investigators know that, from an ethical standpoint, they should prospectively register clinical trials in a public registry before starting them. In addition, it is believed that this approach will help to reduce publication bias. However, most studies conducted in humans are observational rather than experimental. It is estimated that less than 2% out of 2 million concluded or ongoing observational studies have been registered. The 2013 revision of the Declaration of Helsinki requires registration of any type of research study involving humans or identifiable samples or data. It is proposed that funding agencies, such as the Fondo de Investigaciones Sanitarias, as well as private companies, require preregistration of observational studies before providing funding. It is also proposed that Research Ethics Committees which, following Spanish regulation, have been using the Declaration as the framework for assessing the ethics of clinical trials with medicines since 1990, should follow the same provisions for the assessment of health-related observational studies: therefore, they should require prospective registration of studies before granting their final approval. This would allow observational study investigators to be educated in complying with an ethical requirement recently introduced in the most important ethical code for research involving humans. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

  15. Changes in physical activity, sedentary time, and risk of falling: The Women's Health Initiative Observational Study.

    PubMed

    Bea, Jennifer W; Thomson, Cynthia A; Wallace, Robert B; Wu, Chunyuan; Seguin, Rebecca A; Going, Scott B; LaCroix, Andrea; Eaton, Charles; Ockene, Judith K; LaMonte, Michael J; Jackson, Rebecca; Jerry Mysiw, W; Wactawski-Wende, Jean

    2017-02-01

    Falling significantly affects quality of life, morbidity, and mortality among older adults. We sought to evaluate the prospective association between sedentary time, physical activity, and falling among post-menopausal women aged 50-79years recruited to the Women's Health Initiative Observational Study between 1993 and 1998 from 40 clinical centers across the United States. Baseline (B) and change in each of the following were evaluated at year 3 (Y3) and year 6 (Y6; baseline n=93,676; Y3 n=76,598; Y6 n=75,428): recreational physical activity (MET-h/wk), sitting, sleeping (min/day), and lean body mass by dual energy X-ray absorptiometry (subset N=6475). Falls per year (0, 1, 2, ≥3) were assessed annually by self-report questionnaire and then dichotomized as ≤1 and ≥2falls/year. Logistic regression models were adjusted for demographics, body mass index, fall history, tobacco and alcohol use, medical conditions, and medications. Higher baseline activity was associated with greater risk of falling at Y6 (18%; p for trend <0.0001). Increasing sedentary time minimally decreased falling (1% Y3; 2% Y6; p<0.05). Increasing activity up to ≥9MET-h/wk. (OR: 1.12, 95% CI: 1.03-1.22) or maintaining ≥9MET-h/wk. (OR: 1.20, 95% CI: 1.13-1.29) increased falling at Y3 and Y6 (p for trend <0.001). Adding lean body mass to the models attenuated these relationships. Physically active lifestyles increased falling among post-menopausal women. Additional fall prevention strategies, such as balance and resistance training, should be evaluated to assist post-menopausal women in reaching or maintaining levels of aerobic activity known to prevent and manage several chronic diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Synoptical Auroral Ovals: A Comparison study with TIMED/GUVI Observations

    NASA Astrophysics Data System (ADS)

    Liou, K.; Paxton, L.; Zhang, Y.

    2007-12-01

    Whether the aurora Australis is a mirror image of its northern hemispheric counterpart is a question that auroral physicists have been wanting to answer. Owing to geophysical constraints, especially the large offset between the location of the southern magnetic and southern geographic poles, there is a paucity of information about the aurora Australis. Comparisons of some instantansous global-scale northern and southern auroras acquired conjugately by Polar and IMAGE spacecraft recently have shown mixed results. In this study, we present data from a different source to provide insight into the global morphology and behavior of the auroral oval. Approximately 20,000 Earth's disk FUV images acquired from the Global Ultraviolet Imager (GUVI) on-board NASA's Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) satellite between February 2002 and February 2006 are processed and analyzed. Synoptic auroral distributions for the northern and southern ovals are derived. Our study result reveals that the statistical oval is nearly hemispherically symmetric (within ±80%). Several known features in the morphology of the aurora Borealis are also observed in the Southern Hemisphere: For instance, the auroral midday gap and the premidnight maximum. The hemispherical symmetry of the auroras deteriorates as the partition of solar illumination in the two hemisphere polar region becomes asymmetric. It is estimated that the solar illumination effect accounts for up to ~50% of the hemispheric asymmetry. We found evidence that suggests that the aurora is suppressed under sunlit conditions in the South just as it is in the North. We also found that the auroral energy flux increases monotonically with the increase of the solar zenith angle. These results suggest that ionospheric conductivity plays an active role in regulating magnetospheric energy deposition in the auroral zone.

  17. Impact of Structured Rounding Tools on Time Allocation During Multidisciplinary Rounds: An Observational Study

    PubMed Central

    Kannampallil, Thomas G; Patel, Vimla L; Patel, Bela; Almoosa, Khalid F

    2016-01-01

    Background Recent research has shown evidence of disproportionate time allocation for patient communication during multidisciplinary rounds (MDRs). Studies have shown that patients discussed later during rounds receive lesser time. Objective The aim of our study was to investigate whether disproportionate time allocation effects persist with the use of structured rounding tools. Methods Using audio recordings of rounds (N=82 patients), we compared time allocation and communication breakdowns between a problem-based Subjective, Objective, Assessment, and Plan (SOAP) and a system-based Handoff Intervention Tool (HAND-IT) rounding tools. Results We found no significant linear dependence of the order of patient presentation on the time spent or on communication breakdowns for both structured tools. However, for the problem-based tool, there was a significant linear relationship between the time spent on discussing a patient and the number of communication breakdowns (P<.05)––with an average of 1.04 additional breakdowns with every 120 seconds in discussion. Conclusions The use of structured rounding tools potentially mitigates disproportionate time allocation and communication breakdowns during rounds, with the more structured HAND-IT, almost completely eliminating such effects. These results have potential implications for planning, prioritization, and training for time management during MDRs. PMID:27940423

  18. Impact of Structured Rounding Tools on Time Allocation During Multidisciplinary Rounds: An Observational Study.

    PubMed

    Abraham, Joanna; Kannampallil, Thomas G; Patel, Vimla L; Patel, Bela; Almoosa, Khalid F

    2016-12-09

    Recent research has shown evidence of disproportionate time allocation for patient communication during multidisciplinary rounds (MDRs). Studies have shown that patients discussed later during rounds receive lesser time. The aim of our study was to investigate whether disproportionate time allocation effects persist with the use of structured rounding tools. Using audio recordings of rounds (N=82 patients), we compared time allocation and communication breakdowns between a problem-based Subjective, Objective, Assessment, and Plan (SOAP) and a system-based Handoff Intervention Tool (HAND-IT) rounding tools. We found no significant linear dependence of the order of patient presentation on the time spent or on communication breakdowns for both structured tools. However, for the problem-based tool, there was a significant linear relationship between the time spent on discussing a patient and the number of communication breakdowns (P<.05)--with an average of 1.04 additional breakdowns with every 120 seconds in discussion. The use of structured rounding tools potentially mitigates disproportionate time allocation and communication breakdowns during rounds, with the more structured HAND-IT, almost completely eliminating such effects. These results have potential implications for planning, prioritization, and training for time management during MDRs.

  19. Waiting for Paternity: An Observational Study of the Timing of Fatherhood.

    ERIC Educational Resources Information Center

    Neville, Brian

    The aim of this study was to examines the effects of life-span contextual variation on father-child relationships. Sixty families in which both parents were either younger than 26 or older than 29 when they began childbearing, and whose oldest or only child was between the ages of 3 and 5 at the time of the study participated. Questionnaires were…

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

    PubMed Central

    Mache, Stefanie; Groneberg, David A

    2009-01-01

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

  1. Observation on Surface Change of Fragile Glass: Temperature - Time Dependence Studied by X-Ray Reflectivity

    SciTech Connect

    Kikkawa, Hiroyuki; Kitahara, Amane; Takahashi, Isao

    2004-04-30

    The structural change of a fragile glass surface close to the glass transition temperature Tg is studied by using X-ray reflectivity. Measurements were performed on surfaces of maltitol, which is a typical polyalcohol fragile glass with Tg = 320K. Upon both heating and cooling, we find the following features which are also noticed in silicate glass surfaces: (i) On heating, the surface morphology indicates a variation at temperatures below Tg; (ii) A drastic increase in surface roughness occurs at a temperature about 333K on heating, which is 13K higher than Tg; (iii) During the cooling of the sample, formation of a low-density surface layer (3nm at 293K) is observed. Prior to the crystallization, nm - {mu}m sized domains were grown at the surface, which might not be reported for other glasses.

  2. Lack of agreement between different observers and methods in the measurement of capillary refill time in healthy volunteers: an observational study

    PubMed Central

    Espinoza, Emilio Daniel Valenzuela; Welsh, Sebastián; Dubin, Arnaldo

    2014-01-01

    Objective Peripheral perfusion abnormalities are relevant manifestations of shock. Capillary refill time is commonly used for their evaluation. However, the reproducibility of capillary refill time measurements and their correlation with other variables of peripheral perfusion, have not been comprehensively evaluated. Our goal was to determine, in healthy volunteers, the agreement between different methods of capillary refill time quantification and different observers, as well as their correlation with other markers of peripheral perfusion. Methods We studied 63 healthy volunteers. Two observers measured capillary refill time by means of two methods, direct view (CRTchronometer) and video analysis (CRTvideo). We also measured perfusion index (PI) derived from pulse plethysmography and finger pad temperature (Tºperipheral). The agreement between observers and methods was assessed using the Bland and Altman method. Correlations were calculated using Pearson's correlation. A p-value<0.05 was considered significant. Results The 95% limits of agreement between the two observers were 1.9 sec for CRTchronometer and 1.7 sec for CRTvideo. The 95% limits of agreement between CRTchronometer and CRTvideo were 1.7 sec for observer 1 and 2.3 sec for observer 2. Measurements of CRTchronometer performed by the two observers were correlated with Tºperipheral. Measurements of CRTvideo performed by the two observers were correlated with Tºperipheral and perfusion index. Conclusion In healthy volunteers, measurements of capillary refill time performed by either different observers or different methods showed poor agreement. Nevertheless, capillary refill time still reflected peripheral perfusion as shown by its correlation with objective variables of peripheral perfusion. PMID:25295821

  3. Mean sojourn time of preclinical gastric cancer in Korean men: a retrospective observational study.

    PubMed

    Bae, Jong-Myon; Shin, Sang Yop; Kim, Eun Hee

    2014-07-01

    This retrospective cohort study aimed to estimate the mean sojourn time (MST) of preclinical gastric cancer in Korean men. The subjects consisted of voluntary male screenees aged 40 to 69 years who underwent subsequent screening gastroscopies after testing negative at a baseline screening performed between January 2007 and December 2011. A new case was defined if gastric cancer cells were present in the biopsy specimens obtained from gastroscopy. The follow-up period was calculated as the number of person-years between the date of baseline screening gastroscopy and positive findings at a subsequent screening. The MST was calculated using transition rates of gastric cancer to determine the best screening interval. Of the 171 979 voluntary male screenees, 61 688 (36%) underwent subsequent screening gastroscopies between January 2007 and December 2011. A total of 91 incident cases were found during 19 598 598 person-years of follow-up. The MST of gastric cancer was 2.37 years (95% confidence intervals, 1.92 to 2.96), and those aged 40 to 49 years had a shorter MST than those 50 to 69 years did. These findings support the 2-year interval of screening recommended by the nationwide gastric cancer screening program in Korea. Further studies for the age-specific MST among women are needed. This retrospective cohort study aimed to estimate the mean sojourn time (MST) of preclinical gastric cancer in Korean men. The subjects consisted of voluntary male screenees aged 40 to 69 years who underwent subsequent screening gastroscopies after testing negative at a baseline screening performed between January 2007 and December 2011. A new case was defined if gastric cancer cells were present in the biopsy specimens obtained from gastroscopy. The follow-up period was calculated as the number of person-years between the date of baseline screening gastroscopy and positive findings at a subsequent screening. The MST was calculated using transition rates of gastric cancer to determine

  4. Mean Sojourn Time of Preclinical Gastric Cancer in Korean Men: A Retrospective Observational Study

    PubMed Central

    Bae, Jong-Myon; Shin, Sang Yop; Kim, Eun Hee

    2014-01-01

    Objectives: This retrospective cohort study aimed to estimate the mean sojourn time (MST) of preclinical gastric cancer in Korean men. Methods: The subjects consisted of voluntary male screenees aged 40 to 69 years who underwent subsequent screening gastroscopies after testing negative at a baseline screening performed between January 2007 and December 2011. A new case was defined if gastric cancer cells were present in the biopsy specimens obtained from gastroscopy. The follow-up period was calculated as the number of person-years between the date of baseline screening gastroscopy and positive findings at a subsequent screening. The MST was calculated using transition rates of gastric cancer to determine the best screening interval. Results: Of the 171 979 voluntary male screenees, 61 688 (36%) underwent subsequent screening gastroscopies between January 2007 and December 2011. A total of 91 incident cases were found during 19 598 598 person-years of follow-up. The MST of gastric cancer was 2.37 years (95% confidence intervals, 1.92 to 2.96), and those aged 40 to 49 years had a shorter MST than those 50 to 69 years did. Conclusions: These findings support the 2-year interval of screening recommended by the nationwide gastric cancer screening program in Korea. Further studies for the age-specific MST among women are needed. PMID:25139166

  5. Fetal cardiac time intervals in healthy pregnancies - an observational study by fetal ECG (Monica Healthcare System).

    PubMed

    Wacker-Gussmann, Annette; Plankl, Cordula; Sewald, Maria; Schneider, Karl-Theo Maria; Oberhoffer, Renate; Lobmaier, Silvia M

    2017-04-28

    Fetal electrocardiogram (fECG) can detect QRS signals in fetuses from as early as 17 weeks' gestation; however, the technique is limited by the minute size of the fetal signal relative to noise ratio. The aim of this study was to evaluate precise fetal cardiac time intervals (fCTIs) with the help of a newly developed fetal ECG device (Monica Healthcare System). In a prospective manner we included 15-18 healthy fetuses per gestational week from 32 weeks onwards. The small and wearable Monica AN24 monitoring system uses standard ECG electrodes placed on the maternal abdomen to monitor fECG, maternal ECG and uterine electromyogram (EMG). Fetal CTIs were estimated on 1000 averaged fetal heart beats. Detection was deemed successful if there was a global signal loss of less than 30% and an analysis loss of the Monica AN24 signal separation analysis of less than 50%. Fetal CTIs were determined visually by three independent measurements. A total of 149 fECGs were performed. After applying the requirements 117 fECGs remained for CTI analysis. While the onset and termination of P-wave and QRS-complex could be easily identified in most ECG patterns (97% for P-wave, PQ and PR interval and 100% for QRS-complex), the T-wave was detectable in only 41% of the datasets. The CTI results were comparable to other available methods such as fetal magnetocardiography (fMCG). Although limited and preclinical in its use, fECG (Monica Healthcare System) could be an additional useful tool to detect precise fCTIs from 32 weeks' gestational age onwards.

  6. AstroSat CZT Imager Observations of GRB 151006A: Timing, Spectroscopy, and Polarization Study

    NASA Astrophysics Data System (ADS)

    Rao, A. R.; Chand, Vikas; Hingar, M. K.; Iyyani, S.; Khanna, Rakesh; Kutty, A. P. K.; Malkar, J. P.; Paul, D.; Bhalerao, V. B.; Bhattacharya, D.; Dewangan, G. C.; Pawar, Pramod; Vibhute, A. M.; Chattopadhyay, T.; Mithun, N. P. S.; Vadawale, S. V.; Vagshette, N.; Basak, R.; Pradeep, P.; Samuel, Essy; Sreekumar, S.; Vinod, P.; Navalgund, K. H.; Pandiyan, R.; Sarma, K. S.; Seetha, S.; Subbarao, K.

    2016-12-01

    AstroSat is a multi-wavelength satellite launched on 2015 September 28. The CZT Imager of AstroSat on its very first day of operation detected a long duration gamma-ray burst (GRB), namely GRB 151006A. Using the off-axis imaging and spectral response of the instrument, we demonstrate that the CZT Imager can localize this GRB correctly to about a few degrees, and it can provide, in conjunction with Swift, spectral parameters similar to those obtained from Fermi/GBM. Hence, the CZT Imager would be a useful addition to the currently operating GRB instruments (Swift and Fermi). Specifically, we argue that the CZT Imager will be most useful for the short hard GRBs by providing localization for those detected by Fermi and spectral information for those detected only by Swift. We also provide preliminary results on a new exciting capability of this instrument: the CZT Imager is able to identify Compton scattered events thereby providing polarization information for bright GRBs. GRB 151006A, in spite of being relatively faint, shows hints of a polarization signal at 100-300 keV (though at a low significance level). We point out that the CZT Imager should provide significant time resolved polarization measurements for GRBs that have fluence three times higher than that of GRB 151006A. We estimate that the number of such bright GRBs detectable by the CZT Imager is five to six per year. The CZT Imager can also act as a good hard X-ray monitoring device for possible electromagnetic counterparts of gravitational wave events.

  7. Physical activity, sedentary behavior time and lipid levels in the Observation of Cardiovascular Risk Factors in Luxembourg study.

    PubMed

    Crichton, Georgina E; Alkerwi, Ala'a

    2015-08-11

    Recently attention has been drawn to the health impacts of time spent engaging in sedentary behaviors. While many studies have investigated general physical activity (PA) in relation to blood lipid levels, the current study aimed to examine the intensity of activity, including sedentary behavior time, and time spent engaging in moderate and intense PA, with concentrations of HDL and LDL-cholesterol, total cholesterol, and triglycerides. Participants comprised 1331 individuals, aged 18 to 70 years, from the Observation of Cardiovascular Risk Factors in Luxembourg (ORISCAV-LUX) study, who underwent objective cardiovascular health assessments and completed the International Physical Activity Questionnaire (IPAQ). Time spent engaging in sedentary behaviors (screen time on a workday and a day off, and total sitting time on a work day), and moderate and intense PA, were related to levels of HDL and LDL-cholesterol, total cholesterol, and triglycerides. Analyses were conducted in the whole sample, and then with stratification according to BMI (normal weight versus overweight/obese). Both lower screen time during days off and higher intense PA time were significantly associated with higher HDL-cholesterol after full adjustment for socio-demographic factors, dietary factors and smoking (both p < 0.05). In normal weight individuals, consistent positive relations between triglycerides, LDL, and total cholesterol with all sedentary behavior time variables were observed (all p < 0.05; adjusted for age, education, gender). There were no statistically significant associations between any intensity level of PA or sedentary behavior time variable and lipid levels in those overweight or obese. Spending less time in sedentary behaviors, and engaging in medium levels of intense physical activity may be associated with a more favorable blood lipid profile, particularly with regard to levels of HDL and triglycerides.

  8. Time since death and decomposition of the human body: variables and observations in case and experimental field studies.

    PubMed

    Mann, R W; Bass, W M; Meadows, L

    1990-01-01

    Much of the difficulty in determining the time since death stems from the lack of systematic observation and research on the decomposition rate of the human body. Continuing studies conducted at the University of Tennessee, Knoxville, provide useful information on the impact of carrion insect activity, ambient temperature, rainfall, clothing, burial and depth, carnivores, bodily trauma, body weight, and the surface with which the body is in contact. This paper reports findings and observations accumulated during eight years of research and case studies that may clarify some of the questions concerning bodily decay.

  9. a Study on the SAR Data Observation Time for the Classification of Planting Condition of Paddy Fields

    NASA Astrophysics Data System (ADS)

    Kimura, A.; Kondo, A.; Mochizuki, K.

    2016-06-01

    In recent years, cultivation methods of rice have been diversified due to the low cost of rice-growing techniques. For example, there is direct sowing of seed rice in paddy field in addition to the practice of usual paddy field to flooding at the time of planting. The yield of the usual paddy field and the direct sowing is different even though the same varieties are grown in the same area. It is necessary to grasp by performing classification for the usual paddy field or direct sowing for the management of agricultural crops. The main objective of this study was to select the observation time for the classification of paddy fields' planting conditions by utilizing Synthetic Aperture Radar TerraSAR-X satellite. The planting conditions included the usual planting of rice, the direct sowing of rice and the soybean. We selected the observation time by the statistical distance of the microwave backscattering in each paddy field for maximizing the planting condition classification. In addition, the satellite data observation timing considered the processing time of the analysis and the acquisition costs. The acquisition was performed 4 periods from 2 periods in the rice growing season and the planting phase. In the current study, we were able to classify the usual planting of rice, the direct sowing of rice and the soybean by TerraSAR-X data for the later planting of rice during mid-May and initial growth of rice in early June.

  10. An observational study assessing completion time and accuracy of completing the tactical combat casualty care card by combat medic trainees.

    PubMed

    Therien, Sean P; Andrews, James E; Nesbitt, Michael E; Mabry, Robert

    2014-01-01

    Prehospital care documentation is crucial to improving battlefield care outcomes. Developed by United States Army Ranger Special Operations Combat Medics (SOCMs), the Tactical Combat Casualty Care (TCCC) is currently fielded to deployed units to record prehospital injury data. This study documents length of time and accuracy of U.S. Army Combat Medic trainees in completing the minimum preestablished required fields on the TCCC card, establishing a baseline for point-of-injury cards. This was a prospective observational study in which U.S. Army combat medic trainees were timed while recording data on the TCCC card in both the classroom and simulated combat environment. We hypothesized that trainees could complete the TCCC card in less than 1 minute with 90% or greater accuracy. We enrolled 728 U.S. Army Combat Medic trainees in the study during May?June 2011 at Fort Sam Houston, TX. We observed an average TCCC card completion time of less than 1 minute with greater than 90% accuracy in the unstressed classroom environment but an increase to nearly 2 minutes on average and a decrease to 85% accuracy in the simulated combat environment. RESULTS imply that the TCCC card is well designed to quickly and accurately record prehospital combat injury information. Further investigation and future studies may compare other prehospital data collection methods with the TCCC card in terms of timely and accurate data collection. 2014.

  11. Does type of hospital ownership influence physicians' daily work schedules? An observational real-time study in German hospital departments

    PubMed Central

    Mache, Stefanie; Scutaru, Cristian; Vitzthum, Karin; Quarcoo, David; Schöffel, Norman; Welte, Tobias; Klapp, Burghard F; Groneberg, David A

    2009-01-01

    Background During the last two decades the German hospital sector has been engaged in a constant process of transformation. One obvious sign of this is the growing amount of hospital privatization. To date, most research studies have focused on the effects of privatization regarding financial outcomes and quality of care, leaving important organizational issues unexplored. Yet little attention has been devoted to the effects of privatization on physicians' working routines. The aim of this observational real-time study is to deliver exact data about physicians' work at hospitals of different ownership. By analysing working hours, further impacts of hospital privatization can be assessed and areas of improvement identified. Methods Observations were made by shadowing 100 physicians working in private, for-profit or non-profit as well as public hospital departments individually during whole weekday shifts in urban German settings. A total of 300 days of observations were conducted. All working activities were recorded, accurate to the second, by using a mobile personal computer. Results Results have shown significant differences in physicians' working activities, depending on hospital ownership, concerning working hours and time spent on direct and indirect patient care. Conclusion This is the first real-time analysis on differences in work activities depending on hospital ownership. The study provides an objective insight into physicians' daily work routines at hospitals of different ownership, with additional information on effects of hospital privatization. PMID:19473487

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

    PubMed

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

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

  13. Comparing the working time between Bar-Code Medication Administration system and traditional medication administration system: an observational study.

    PubMed

    Tsai, Sing-ling; Sun, Ying-Chou; Taur, Fang-Meei

    2010-10-01

    The medical institutions had paid attention to the medication error via Bar-Code Medication Administration system (BCMA) to improve the accuracy of the medication process for patient safety. Yet, the working time of drug delivery was under investigated. Comparing the working time of oral drugs between Bar-Code Medication Administration system and traditional medication administration system. Purposive sampling, observational and questionnaire study design was used. Participants were invited from a medical center in North Taiwan, 51 nurses from three neurosurgical wards who were using the BCMA system; 51 nurses from three neurological wards who were using traditional medication administration record (MAR). The working time of oral medication administration including order transcribing, verifying, drug giving, and renew in BCMA and traditional group were observed and recorded. (1) Working time for oral medication administration reduced from 36.49 to 18.42 s after BCMA implementation. (2) In the same period, working times for oral drug administration were 62.89 and 56.07 s before and after BCMA implementation in the traditional group. (3) Most nurses (66.7%) felt BCMA could save their oral drug administration time under 50%. (4) Frequent crash of the wireless network, which extended the oral drug administration time was the major threat in the process of BCMA implementation. (5) 93.5% nurses think that BCMA could enhance patient oral medication safety and promote quality of oral medication. The results demonstrated that implementation of BCMA for oral medication could reduce half of the time for oral medication delivery. Nurses coordinated the hardware and software by accommodating the new facilities and operating BCMA system. The stability of wireless Internet was the main threat. However, 93.5% nurses think that BCMA could enhance patient oral medication safety in spite of making more effort in learning new technology. Copyright © 2010 Elsevier Ireland Ltd. All

  14. Changes in time-segment specific physical activity between ages 10 and 14 years: A longitudinal observational study

    PubMed Central

    Brooke, Hannah L.; Atkin, Andrew J.; Corder, Kirsten; Ekelund, Ulf; van Sluijs, Esther M.F.

    2016-01-01

    Objectives Describe (1) time-segment specific changes in physical activity (PA) into adolescence, (2) differences in change in PA between specific time-segments (weekdays–weekends, in-school–out-of-school, out-of-school–weekends, lesson-time–lunch-time), and (3) associations of change in time-segment specific with overall PA. Design Longitudinal observational study (4-year follow-up). Methods Children from the SPEEDY study (n = 769, 42% boys) had PA measured by accelerometer for at least three days at ages 10.2 ± 0.3, 11.2 ± 0.3 and 14.3 ± 0.3 years. Changes in moderate-to-vigorous PA (ΔMVPA, minutes ≥2000 counts/minute [cpm]) and total PA (ΔTPA, average cpm) during weekdays, weekends, in-school, out-of-school, lesson-times and lunch-times, were tested using three level (age, individual, school) mixed-effects linear regression. Differences in ΔMVPA/ΔTPA between time-segments were tested using time-segment × age interaction terms. Associations of four-year time-segment specific ΔMVPA/ΔTPA with four-year overall ΔMVPA/ΔTPA were tested using two level (time-segment specific ΔMVPA/ΔTPA, school) mixed-effects linear regression. Results MVPA and TPA declined in all time-segments, except lesson-time MVPA. Annual ΔMVPA and, for boys only, ΔTPA was greater on weekends than weekdays (beta ± SE for interaction term: boys, −3.53 ± 0.83 min, −29.64 ± 7.64 cpm; girls, −2.20 ± 0.64 min) and out-of-school (boys, −4.36 ± 0.79 min, −19.36 ± 8.46 cpm; girls, −2.44 ± 0.63 min). ΔMVPA and ΔTPA during lunch-time was greater than during lesson-time (boys, −0.96 ± 0.20 min, −36.43 ± 6.55 cpm; girls, −0.90 ± 0.13 min, −38.72 ± 4.40 cpm). ΔTPA was greater out-of-school than in-school (boys, −19.89 ± 6.71 cpm; girls, −18.46 ± 6.51 cpm). For all time-segments, four-year ΔMVPA/ΔTPA was positively associated with four-year overall ΔMVPA/ΔTPA (all p < 0.042), except for girl

  15. Timed Rise from Floor as a Predictor of Disease Progression in Duchenne Muscular Dystrophy: An Observational Study

    PubMed Central

    Mazzone, Elena S.; Coratti, Giorgia; Sormani, Maria Pia; Messina, Sonia; Pane, Marika; D'Amico, Adele; Colia, Giulia; Fanelli, Lavinia; Berardinelli, Angela; Gardani, Alice; Lanzillotta, Valentina; D’Ambrosio, Paola; Petillo, Roberta; Cavallaro, Filippo; Frosini, Silvia; Bello, Luca; Bonfiglio, Serena; De Sanctis, Roberto; Rolle, Enrica; Forcina, Nicola; Magri, Francesca; Vita, Gianluca; Palermo, Concetta; Donati, Maria Alice; Procopio, Elena; Arnoldi, Maria Teresa; Baranello, Giovanni; Mongini, Tiziana; Pini, Antonella; Battini, Roberta; Pegoraro, Elena; Torrente, Yvan; Previtali, Stefano C.; Bruno, Claudio; Politano, Luisa; Comi, Giacomo P.; D’Angelo, Maria Grazia; Bertini, Enrico; Mercuri, Eugenio

    2016-01-01

    Background The role of timed items, and more specifically, of the time to rise from the floor, has been reported as an early prognostic factor for disease progression and loss of ambulation. The aim of our study was to investigate the possible effect of the time to rise from the floor test on the changes observed on the 6MWT over 12 months in a cohort of ambulant Duchenne boys. Subjects and methods A total of 487 12-month data points were collected from 215 ambulant Duchenne boys. The age ranged between 5.0 and 20.0 years (mean 8.48 ±2.48 DS). Results The results of the time to rise from the floor at baseline ranged from 1.2 to 29.4 seconds in the boys who could perform the test. 49 patients were unable to perform the test at baseline and 87 at 12 month The 6MWT values ranged from 82 to 567 meters at baseline. 3 patients lost the ability to perform the 6mwt at 12 months. The correlation between time to rise from the floor and 6MWT at baseline was high (r = 0.6, p<0.01). Conclusions Both time to rise from the floor and baseline 6MWT were relevant for predicting 6MWT changes in the group above the age of 7 years, with no interaction between the two measures, as the impact of time to rise from the floor on 6MWT change was similar in the patients below and above 350 m. Our results suggest that, time to rise from the floor can be considered an additional important prognostic factor of 12 month changes on the 6MWT and, more generally, of disease progression. PMID:26982196

  16. How registered nurses, licensed practical nurses and resident aides spend time in nursing homes: An observational study.

    PubMed

    McCloskey, Rose; Donovan, Cindy; Stewart, Connie; Donovan, Alicia

    2015-09-01

    Calls for improved conditions in nursing homes have pointed to the importance of optimizing the levels and skills of care providers. Understanding the work of care providers will help to determine if staff are being used to their full potential and if opportunities exist for improved efficiencies. To explore the activities of care providers in different nursing homes and to identify if variations exist within and across homes and shifts. A multi-centre cross-sectional observational work flow study was conducted in seven different nursing homes sites in one Canadian province. Data were collected by a research assistant who conducted 368 h of observation. The research assistant collected data by following an identical route in each site and recording observations on staff activities. Findings indicate staff activities vary across roles, sites and shifts. Licensed practical nurses (nursing assistants) have the greatest variation in their role while registered nurses have the least amount of variability. In some sites both registered nurses and licensed practical nurses perform activities that may be safely delegated to others. Care providers spend as much as 53.7% of their time engaged in non-value added activities. There may be opportunities for registered nurses and licensed practical nurses to delegate some of their activities to non-regulated workers. The time care providers spend in non-value activities suggest there may be opportunities to improve efficiencies within the nursing home setting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Studying disruptive vocalization and contextual factors in the nursing home using computer-assisted real-time observation.

    PubMed

    Burgio, L D; Scilley, K; Hardin, J M; Janosky, J; Bonino, P; Slater, S C; Engberg, R

    1994-09-01

    Disruptive vocalization (DV) is both a prevalent and disturbing problem in nursing homes. We developed a computer-assisted data collection system for real-time observation and recording of DV and various environmental contextual factors. Both frequency and duration of DV were recorded for 11 residents along with their location in the nursing home, their activity, environmental sound, the social environment, and whether or not the resident was physically restrained. The actual time of all events was also recorded. Measures of cognitive and ADL status were administered. The average occurrence of DV was 22 per hour and the average duration per occurrence was 26 seconds. The results show a significant upward linear trend in the occurrence of DV across the day. This is consistent with the "sundowning" hypothesis. A Cox Proportional Hazards Regression model indicates that another person present in the setting (p = .004) and resident presence at the nursing home hairdresser (p = .07) were associated with shorter duration episodes of DV. Correlational analyses indicate that both higher frequency and longer duration DV are related to greater cognitive impairment, and higher frequency DV is related to greater ADL impairment. We conclude that this computer-assisted real-time observational system is a useful and promising tool for studying disruptive behavior in its environmental context.

  18. Landslide Monitoring Using Insar Time-Series and GPS Observations, Case Study: Shabkola Landslide in Northern Iran

    NASA Astrophysics Data System (ADS)

    Mirzaee, S.; Motagh, M.; Akbari, B.

    2017-05-01

    Shabkola is a village located in Mazandaran province of northern Iran that suffers from the mass movement happening in the upstream. Deforestation and changes to land use are the main reasons for the soil instability in this region, which together with steep slope, relatively high precipitation rate and natural erosion has led to such a condition. The area of mass movement is approximately 90 hectares which is a big threat for people living in the region. In this study, we have utilized two different geodetic techniques including InSAR time-series analysis and GPS measurements to assess slope stability in Shabkola. The SAR dataset includes 19 ALOS/PALSAR images spanning from July 2007 to February 2011 while GPS observations are collected in 5 campaigns from September 2011 to May 2014. Displacement as much as approximately 11.7 m in slope direction was detected by GPS observations for the 2011-2014 time period. Most of the slope geometry is in north-south direction, for which the sensitivity of InSAR for displacement detection is low. However, ALOS PALSAR data analysis revealed a previously unknown landslide, covered by dense vegetation in the northern part of main Shabkola landslide, showing line-of-sight velocity of approximately 2cm/year in the time period 2007-2011.

  19. Can mobile technology improve response times of junior doctors to urgent out-of-hours calls? A prospective observational study.

    PubMed

    Herrod, P J J; Barclay, C; Blakey, J D

    2014-04-01

    The Hospital at Night system has been widely adopted to manage Out-of-Hours workload. However, it has the potential to introduce delays and corruption of information. The introduction of newer technologies to replace landlines, pagers and paper may ameliorate these issues. To establish if the introduction of a Hospital at Night system supported by a wireless taskflow system affected the escalation of high Early Warning Scores (EWSs) to medical attention, and the time taken to medical review. Prospective 'pre and post' observational study in a teaching hospital in the UK. Review of observation charts and medical records, and data extraction from the electronic taskflow system. The implementation of a technology-supported Hospital at Night system was associated with a significant decrease in time to documentation of initial review in those who were reviewed. However, there was no change in the proportion of those with a high EWS that were reviewed, and throughout the study a majority of patients with high EWSs were not reviewed in accordance with guidelines. Introduction of a Hospital at Night system supported by mobile technology appeared to improve the transfer of information, but did not affect the nursing decision whether to escalate abnormal findings.

  20. How Entrustment Is Informed by Holistic Judgments Across Time in a Family Medicine Residency Program: An Ethnographic Nonparticipant Observational Study.

    PubMed

    Sagasser, Margaretha H; Fluit, Cornelia R M G; van Weel, Chris; van der Vleuten, Cees P M; Kramer, Anneke W M

    2017-06-01

    Entrustment has mainly been conceptualized as delegating discrete professional tasks. Because residents provide most of their patient care independently, not all resident performance is visible to supervisors; the entrustment process involves more than granting discrete tasks. This study explored how supervisors made entrustment decisions based on residents' performance in a long-term family medicine training program. A qualitative nonparticipant observational study was conducted in 2014-2015 at competency-based family medicine residency programs in the Netherlands. Seven supervisor-resident pairs participated. During two days, one researcher observed first-year residents' patient encounters, debriefing sessions, and supervisor-resident educational meetings and interviewed them separately afterwards. Data were collected and analyzed using iterative, phenomenological inductive research methodology. The entrustment process developed over three phases. Supervisors based their initial entrustment on prior knowledge about the resident. In the ensuing two weeks, entrustment decisions regarding independent patient care were derived from residents' observed general competencies necessary for a range of health problems (clinical reasoning, decision making, relating to patients); medical knowledge and skills; and supervisors' intuition. Supervisors provided supervision during and after encounters. Once residents performed independently, supervisors kept reevaluating their decisions, informed by residents' overall growth in competencies rather than by adhering to a predefined set of tasks. Supervisors in family medicine residency training took a holistic approach to trust, based on general competencies, knowledge, skills, and intuition. Entrustment started before training and developed over time. Building trust is a mutual process between supervisor and resident, requiring a good working relationship.

  1. Timing of Percutaneous Endoscopic Gastrostomy for Acute Ischemic Stroke: An Observational Study From the US Nationwide Inpatient Sample.

    PubMed

    George, Benjamin P; Kelly, Adam G; Albert, George P; Hwang, David Y; Holloway, Robert G

    2017-02-01

    Stroke guidelines recommend time-limited trials of nasogastric feeding prior to percutaneous endoscopic gastrostomy (PEG) tube placement. We sought to describe timing of PEG placement and identify factors associated with early PEG for acute ischemic stroke. We designed a retrospective observational study to examine time to PEG for ischemic stroke admissions in the Nationwide Inpatient Sample, 2001 to 2011. We defined early PEG placement as 1 to 7 days from admission. Using multivariable regression analysis, we identified the effects of patient and hospital characteristics on PEG timing. We identified 34 623 admissions receiving a PEG from 2001 to 2011, 53% of which received the PEG 1 to 7 days from admission. Among hospitals placing ≥10 PEG tubes, median time to PEG for individual hospitals ranged from 3 days to over 3 weeks (interquartile range 6-8.5 days). Older adult age groups were associated with early PEG (≥85 years versus 18-54 years: adjusted odds ratio 1.68, 95% confidence interval 1.50-1.87). Those receiving a PEG and tracheostomy were more likely to receive the PEG beyond 7 days, and these patients were more often younger compared with PEG only recipients. Those admitted to high-volume hospitals were more likely to receive their PEG early (≥350 versus <150 hospitalizations; adjusted odds ratio 1.26, 95% confidence interval 1.17-1.35). More than half of the PEG recipients received their surgical feeding tube within 7 days of admission. The oldest old, who may benefit most from time-limited trials of nasogastric feeding for ≥2 to 3 weeks, were most likely to receive a PEG within 7 days. © 2016 American Heart Association, Inc.

  2. Features and amenities of school playgrounds: A direct observation study of utilization and physical activity levels outside of school time

    PubMed Central

    2011-01-01

    Background A significant amount of research has examined whether park or playground availability is associated with physical activity. However, little research has examined whether specific features or amenities of parks or playgrounds, such as the number of unique types of playground equipment or the safety of the equipment is associated with utilization of the facility or physical activity levels while at the facility. There are no studies that use direct observation and a detailed park assessment to examine these associations. Methods Twenty urban schoolyards in the Midwest, ten of which were renovated, were included in this study. Using a detailed environmental assessment tool (i.e., Environmental Assessment of Public Recreation Spaces), information on a variety of playground attributes was collected. Using direct observation (i.e., System for Observing Play and Leisure Activity in Youth), the number of adults, girls and boys attending each schoolyard and their physical activity levels were recorded. Each schoolyard was observed ten times for 90 minutes each time outside of school hours. Clustered multivariable negative binomial regressions and linear regressions were completed to examine the association between playground attributes and utilization of the schoolyard and the proportion active on the playground, respectively. Effect modification by renovation status was also examined. Results At renovated schoolyards, the total number of play features was significantly associated with greater utilization in adults and girls; overall cleanliness was significantly associated with less utilization in girls and boys; and coverage/shade for resting features was significantly associated with greater utilization in adults and boys. At unrenovated schoolyards, overall safety was significantly associated with greater utilization in boys. No playground attribute was associated with the proportion active on the playground after adjusting for all other significant

  3. Pilot study on real-time motion detection in UAS video data by human observer and image exploitation algorithm

    NASA Astrophysics Data System (ADS)

    Hild, Jutta; Krüger, Wolfgang; Brüstle, Stefan; Trantelle, Patrick; Unmüßig, Gabriel; Voit, Michael; Heinze, Norbert; Peinsipp-Byma, Elisabeth; Beyerer, Jürgen

    2017-05-01

    Real-time motion video analysis is a challenging and exhausting task for the human observer, particularly in safety and security critical domains. Hence, customized video analysis systems providing functions for the analysis of subtasks like motion detection or target tracking are welcome. While such automated algorithms relieve the human operators from performing basic subtasks, they impose additional interaction duties on them. Prior work shows that, e.g., for interaction with target tracking algorithms, a gaze-enhanced user interface is beneficial. In this contribution, we present an investigation on interaction with an independent motion detection (IDM) algorithm. Besides identifying an appropriate interaction technique for the user interface - again, we compare gaze-based and traditional mouse-based interaction - we focus on the benefit an IDM algorithm might provide for an UAS video analyst. In a pilot study, we exposed ten subjects to the task of moving target detection in UAS video data twice, once performing with automatic support, once performing without it. We compare the two conditions considering performance in terms of effectiveness (correct target selections). Additionally, we report perceived workload (measured using the NASA-TLX questionnaire) and user satisfaction (measured using the ISO 9241-411 questionnaire). The results show that a combination of gaze input and automated IDM algorithm provides valuable support for the human observer, increasing the number of correct target selections up to 62% and reducing workload at the same time.

  4. FIRE I - Extended Time Observations Data Sets

    Atmospheric Science Data Center

    2013-08-01

    FIRE I - Extended Time Observations Data Sets First ISCCP Regional Experiment (FIRE) I - Extended Time Observations were conducted in Utah. Relevant Documents:  FIRE Project Guide FIRE I - Extended Time Observations Home Page SCAR-B Block:  ...

  5. Timing the initiation of renal replacement therapy for acute kidney injury in Canadian intensive care units: a multicentre observational study.

    PubMed

    Clark, Edward; Wald, Ron; Levin, Adeera; Bouchard, Josée; Adhikari, Neill K J; Hladunewich, Michelle; Richardson, Robert M A; James, Matthew T; Walsh, Michael W; House, Andrew A; Moist, Louise; Stollery, Daniel E; Burns, Karen E A; Friedrich, Jan O; Barton, James; Lafrance, Jean-Philippe; Pannu, Neesh; Bagshaw, Sean M

    2012-09-01

    The optimal timing for starting renal replacement therapy (RRT) in patients with acute kidney injury (AKI) is unknown. Defining current practice is necessary to design interventional trials. We describe the current Canadian practice regarding the timing of RRT initiation for AKI. An observational study of patients undergoing RRT for AKI was undertaken at 11 intensive care units (ICUs) across Canada. Data were captured on demographics, clinical and laboratory findings, indications for RRT, and timing of RRT initiation. Among 119 consecutive patients, the most common ICU admission diagnosis was sepsis/septic shock, occurring in 54%. At the time of RRT initiation, the median and interquartile range (IQR) serum creatinine level was 322 (221-432) μmol·L(-1). The mean (SD) values for other parameters were as follows: Sequential Organ Failure Assessment (SOFA) score 13.4 (4.1), pH 7.25 (0.15), potassium 4.6 (1.0) mmol·L(-1). Also, 64% fulfilled the serum creatinine-based criterion for Acute Kidney Injury Network (AKIN) stage 3. Severity of illness, measured using Acute Physiology and Chronic Health Evaluation (APACHE II) and SOFA scores, did not correlate with AKI severity as defined by the serum creatinine-based AKIN criteria. Median (IQR) time from hospital and ICU admission to the start of RRT was 2.0 (1.0-7.0) days and 1.0 (0-2.0) day, respectively. Patients admitted to an ICU who were started on RRT generally had advanced AKI, high-grade illness severity, and multiorgan dysfunction. Also, they were started on RRT shortly after hospital presentation. We describe the current state of practice in Canada regarding the initiation of RRT for AKI in critically ill patients, which can inform the designs of future interventional trials.

  6. Three cycles of human biomonitoring in Flanders - Time trends observed in the Flemish Environment and Health Study.

    PubMed

    Schoeters, Greet; Govarts, Eva; Bruckers, Liesbeth; Den Hond, Elly; Nelen, Vera; De Henauw, Stefaan; Sioen, Isabelle; Nawrot, Tim S; Plusquin, Michelle; Vriens, Annette; Covaci, Adrian; Loots, Ilse; Morrens, Bert; Coertjens, Dries; Van Larebeke, Nicolas; De Craemer, Sam; Croes, Kim; Lambrechts, Nathalie; Colles, Ann; Baeyens, Willy

    2017-03-01

    To follow time trends in exposure to environmental chemicals, three successive campaigns of the Flemish Environment and Health Study (FLEHS) have recruited and sampled in total 5825 participants between 2002 and 2014. Cord samples from newborns, urine and blood samples from 14 to 15 years old adolescents and from adults between 50 and 65 years old were analysed in geographical representative samples of the Flemish population. The data of the different campaigns were considered per age group and per biomarker after adjustment for predefined covariates to take into account differences in characteristics of the study populations over time. Geometric means were calculated. Multiple linear regression was used to evaluate time trends. The concentration of serum biomarkers for persistent organic pollutants (POPs), such as marker polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p'-DDE), the major metabolite of dichlorodiphenyltrichloroethane (DDT), and hexachlorobenzene (HCB) expressed per g lipid, decreased significantly with time. The levels of DDE in all age groups and those of PCBs in cord and adolescent serum samples were almost halved in a time period of ten years. HCB levels were reduced by a factor of 4 in adolescents and in adults. Mean serum concentrations of the more recently regulated perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were significantly lower in cord samples of 2013 compared to samples of 2007. The decline was more pronounced for PFOS than for PFOA. In the same period, mean metabolite levels of di-2-ethylhexyl phthalate (DEHP) and of di-n-butyl phthalate (DBP) decreased significantly in urine samples of adolescents with sharper declines for DEHP than for DBP. Cadmium and lead levels in cord and adolescent blood samples were significantly lower in the recent campaigns than 10 years before. Also the mean urinary cadmium level in adults was 35% lower compared to adult samples of 2002. Such favourable trends

  7. Impact of STROBE Statement Publication on Quality of Observational Study Reporting: Interrupted Time Series versus Before-After Analysis

    PubMed Central

    Bastuji-Garin, Sylvie; Sbidian, Emilie; Gaudy-Marqueste, Caroline; Ferrat, Emilie; Roujeau, Jean-Claude; Richard, Marie-Aleth; Canoui-Poitrine, Florence

    2013-01-01

    Background In uncontrolled before-after studies, CONSORT was shown to improve the reporting of randomised trials. Before-after studies ignore underlying secular trends and may overestimate the impact of interventions. Our aim was to assess the impact of the 2007 STROBE statement publication on the quality of observational study reporting, using both uncontrolled before-after analyses and interrupted time series. Methods For this quasi-experimental study, original articles reporting cohort, case-control, and cross-sectional studies published between 2004 and 2010 in the four dermatological journals having the highest 5-year impact factors (≥4) were selected. We compared the proportions of STROBE items (STROBE score) adequately reported in each article during three periods, two pre STROBE period (2004–2005 and 2006–2007) and one post STROBE period (2008–2010). Segmented regression analysis of interrupted time series was also performed. Results Of the 456 included articles, 187 (41%) reported cohort studies, 166 (36.4%) cross-sectional studies, and 103 (22.6%) case-control studies. The median STROBE score was 57% (range, 18%–98%). Before-after analysis evidenced significant STROBE score increases between the two pre-STROBE periods and between the earliest pre-STROBE period and the post-STROBE period (median score2004–05 48% versus median score2008–10 58%, p<0.001) but not between the immediate pre-STROBE period and the post-STROBE period (median score2006–07 58% versus median score2008–10 58%, p = 0.42). In the pre STROBE period, the six-monthly mean STROBE score increased significantly, by 1.19% per six-month period (absolute increase 95%CI, 0.26% to 2.11%, p = 0.016). By segmented analysis, no significant changes in STROBE score trends occurred (−0.40%; 95%CI, −2.20 to 1.41; p = 0.64) in the post STROBE statement publication. Interpretation The quality of reports increased over time but was not affected by STROBE. Our findings raise

  8. Comparison of fluoroscopy time during coronary angiography and interventions by radial and femoral routes- can we decrease the fluoroscopy time with increased experience? An observational study.

    PubMed

    Farman, Muhammad Tariq; Khan, Naveed Ullah; Sial, Jawaid Akber; Saghir, Tahir; Rizvi, Syed Nadeem Hasan; Zaman, Khan Shah

    2011-11-01

    Radial route of access is increasingly being used for coronary angiograms and intervention. However, radiation exposure of operators was not known in our set up with either transfemoral or transradial procedures. The objective of the study was to compare related peripheral arterial route radiation exposure of operators by assessing fluoroscopy time. The secondary objective was to determine the relationship of operator experience with fluoroscopy time. This observational study was conducted in a tertiary care center - Cardiovascular Institute of Karachi (Pakistan) during the period of July 1(st) 2009 to September 30(th) 2009. We studied 1016 consecutive adult patients referred for coronary angiography (CA) or percutaneous coronary intervention (PCI). Patients who underwent right heart catheterization or for valvuloplasty were excluded from the study. Out of these 1016 patients, 928 were diagnostic CAs (734 via femoral route [f-CA] and 194 via radial route [r-CA]) and 88 were PCI (64 via femoral route [f-PCI] and 24 via radial route [r-PCI]). Fluoroscopy time was recorded as a surrogate of radiation exposure. Statistical analysis was performed using unpaired t, Mann-Whitney U, Chi-square and ANOVA tests. Mean fluoroscopy time was found to be significantly higher in patients who underwent r-CA (6.3±3.8 vs 4.0±2.9 min; p<0.001) and r-PCI (15.1±11.8 vs 10.3±7.4 min; p=0.02) as compared with those underwent f-CA and f-PCI. Mean fluoroscopy time of well experienced operators was also high in r-CAs (5.4±2.9 vs 4.2±3.5 min; p=0.004). Radial procedures are associated with longer fluoroscopy time that may result in high radiation exposure to radial operators. Even well experienced radial operators cannot minimize their fluoroscopy time to the level of well experienced femoral operators.

  9. Type of oral solid medication packaging and medication preparation time in nursing homes: A direct observation study.

    PubMed

    Cready, C M; Hudson, C; Dreyer, K

    2017-06-05

    Medication administration is a substantial portion of the workday in nursing homes, with the medication preparation step being the most time-consuming. However, little is known about how medication preparation time is affected by the type of packaging used for oral solid medications (ie, tablets/capsules). We examined the effects of two types of packaging. As fewer steps are associated with strip packaging compared to bingo card packaging, we hypothesized that the increase in medication preparation seconds per resident with each additional oral solid medication would be smaller when strip packaging was used. A total of 430 medication preparations conducted by eight nurses during the regularly scheduled morning medication administration period in two nursing homes-using strip packaging and bingo card packaging, respectively-were observed. Each medication preparation observation was matched to its corresponding medication administration record and observations averaged across resident. Using the resident sample (N=149), we estimated three regression models (adjusting the standard errors for the clustering of resident by nurse). The first model regressed medication preparation seconds on the number of oral solid medications. The second model added the type of packaging used and the control variables (type of unit [long-term care, post-acute care], the number of one-half pills and the dosage form diversity in the preparation). To test our hypothesis, the third model added an interaction term between the number of oral solid medications and the type of packaging used. As hypothesized, all else equal, the number of oral solid medications tended to increase medication preparation time per resident in both nursing homes, but the increase was smaller in the strip packaging nursing home (P<.05). Each additional oral solid medication in the bingo card packaging nursing home increased medication preparation by an average of 13 seconds (b=13.077), whereas each oral solid

  10. Early impairment of intracranial conduction time predicts mortality in deeply sedated critically ill patients: a prospective observational pilot study.

    PubMed

    Azabou, Eric; Rohaut, Benjamin; Heming, Nicholas; Magalhaes, Eric; Morizot-Koutlidis, Régine; Kandelman, Stanislas; Allary, Jeremy; Moneger, Guy; Polito, Andrea; Maxime, Virginie; Annane, Djillali; Lofaso, Frederic; Chrétien, Fabrice; Mantz, Jean; Porcher, Raphael; Sharshar, Tarek

    2017-12-01

    Somatosensory (SSEP) and brainstem auditory (BAEP) evoked potentials are neurophysiological tools which, respectively, explore the intracranial conduction time (ICCT) and the intrapontine conduction time (IPCT). The prognostic values of prolonged cerebral conduction times in deeply sedated patients have never been assessed. Sedated patients are at risk of developing new neurological complications, undetected. In this prospective observational bi-center pilot study, we investigated whether early impairment of SSEP's ICCT and/or BAEP's IPCT could predict in-ICU mortality or altered mental status (AMS), in deeply sedated critically ill patients. SSEP by stimulation of the median nerve and BAEP were assessed in critically ill patients receiving deep sedation on day 3 following ICU admission. Deep sedation was defined by a Richmond Assessment sedation Scale (RASS) <-3. Mean left- and right-side ICCT and IPCT were measured for each patient. Primary and secondary outcomes were, respectively, in-ICU mortality and AMS defined as the occurrence of delirium and/or delayed awakening after discontinuation of sedation. Eighty-six patients were studied of which 49 (57%) were non-brain-injured and 37 (43%) were brain-injured. Impaired ICCT was a predictor of in-ICU mortality after adjustment on the global Sequential Organ Failure Assessment score (SOFA) [OR (95% CI) = 2.69 (1.05-6.85); p = 0.039] and on the non-neurological SOFA components [2.67 (1.05-6.81); p = 0.040]. IPCT was more frequently delayed in the subgroup of patients who developed post-sedation AMS (24%) compared those without AMS (0%). However, this difference did not reach statistical significance (p = 0.053). Impairment rates of ICCT and IPCT were not found to be significantly different between non-brain- and brain-injured subgroups of patients. In critically ill patients receiving deep sedation, early ICCT impairment was associated with mortality. Somatosensory and brainstem auditory evoked potentials may

  11. Are risk factors common to thyroid cancer and nodule? A forty years observational time-trend study.

    PubMed

    Carpi, Angelo; Rossi, Giuseppe; Romani, Rossana; Di Coscio, Giancarlo; Nicolini, Andrea; Simoncini, Tommaso; Russo, Matteo; Mechanick, Jeffrey

    2012-01-01

    A progressive increase in the incidence of thyroid cancer (TC) has been reported over the last few decades. This either reflects the increased number of newly discovered and accurately selected thyroid nodules with more sensitive technologies and a relative more potent carcinogenic effect of pathogenetic factors in malignant, but not benign nodules. This observational time-trend study addresses this issue by analysing the proportion of TC within 8411 consecutive thyroid nodule (TN) patients evaluated in Pisa by the same pathology Department and individual clinician over a four-decade period. From 1972 to 1979 surgery was used to detect TC among the TN patients: 1140 TN patients were operated on and 35 cancers were detected (3.1% of all the TN patients). Subsequently, needle aspiration techniques were used to select TN for surgery. From 1980 to 1992, 5403 TN patients were examined, 483 were selected for surgery, and 150 cancers were found (2.8% of all the TN patients). From 1993 to 2010, 1568 TN patients were examined, 143 were selected for surgery, and 46 cancers were found (2.9% of all the TN patients). Therefore, in the University Hospital of Pisa, and independent of preoperative TN selection protocols, these proportions of TN eventually found to harbor TC remained statistically unchanged over 40 years (p = 0.810). This finding suggests that pathogenic risk factors and more sensitive diagnostic technologies did not differentially affect the incidence of TN and TC.

  12. Clinical characteristics of patients with type 2 diabetes mellitus at the time of insulin initiation: INSTIGATE observational study in Spain

    PubMed Central

    Dilla, Tatiana; Reviriego, Jesús; Castell, Conxa; Goday, Albert

    2009-01-01

    Little information is available on the management of patients with type 2 diabetes mellitus (DM2) in regular clinical practice, prior to and at the point of initiating treatment with insulin. The INSTIGATE study provides a description of the clinical profile of the patient with DM2 who begins treatment with insulin in both primary and secondary care. A total of 224 patients who had been diagnosed with DM2, were not responding to oral treatment, and began receiving insulin were included in the INSTIGATE study in Spain. Demographic data were collected, as well as data on macro- and microvascular complications of diabetes and comorbidities, past medical history of diabetes and oral treatment administered, the clinical severity of diabetes (HbA1c concentration) and insulin treatment initiated. Mean age of the sample was 65.4 years and 56.7% were men. There were 87% of patients who had a diagnosis of at least one significant comorbidity, notably hypertension and hyperlipidemia. The patient profile for metabolic syndrome was met by 75.1% of the patients. There was a higher incidence of macrovascular complications (38.4%) than microvascular complications (16.1%). Prior to insulin initiation, the most recent mean HbA1c was 9.2%. The majority of patients had been treated in the last 12 months with sulfonylureas and/or metformin (69.6 and 57.6%). The most common treatment prior to insulinization was the co-administration of two oral antidiabetics (OADs) (37.5%). Patients with DM2 observed in the study presented with elevated mean HbA1c and body mass index levels, comorbidities and complications related to diabetes at the time of insulin initiation. Changes and adjustments in treatment from diagnosis of diabetes occur when HbA1c levels are far above those recommended by the IDF (International Diabetes Federation), a factor which could be contributing to the development of both macrovascular and microvascular complications in the patient profile described in the study. PMID

  13. The relationship between pulmonary artery acceleration time and mean pulmonary artery pressure in patients undergoing cardiac surgery: An observational study.

    PubMed

    Cowie, Brian; Kluger, Roman; Rex, Steffen; Missant, Carlo

    2016-01-01

    A noninvasive method of estimating pulmonary arterial pressures is required, as the use of the pulmonary artery catheter (PAC) is decreasing in cardiac anaesthesia. Pulmonary hypertension is defined as a mean pulmonary artery pressure (MPAP) at least 25 mmHg and this can be estimated echocardiographically by measuring the pulmonary acceleration time (PAT). This relationship has not been validated when measured using transoesophageal echocardiography (TOE) in anaesthetised patients having cardiac surgery. We hypothesised that there was a quantifiable relationship between PAT and MPAP. We aimed to assess this relationship in cardiac surgical patients undergoing general anaesthesia with TOE. An observational study. Catholic University Hospital, Leuven, Belgium, between August and December 2013. Ninety-eight patients having cardiac surgery, where intraoperative TOE was used and a PAC was inserted as part of routine care. Nil. PAT and MPAP were measured simultaneously with TOE and the PAC and this relationship was assessed. PAT and MPAP measurements were possible in all patients. There was a curvilinear relationship between PAT and MPAP with a PAT of less than 107 ms detecting pulmonary hypertension with a sensitivity of 75% and a specificity of 94.8%. The area under the receiver operating characteristic (ROC) curve was 0.87 [95% confidence interval (95% CI) 0.80 to 0.95]. Below a PAT of 107 ms, the relationship was relatively linear and could be described by the equation MPAP (mmHg) = 77 -  (0.49 x PAT). Ninety-five percent of the pressures estimated by this equation are within ±13.8 mmHg of the measured pressure. Estimation of PAT with TOE in anaesthetised cardiac surgical patients is possible. PAT is good at discriminating between patients with and without pulmonary hypertension, with a cut-off of less than 107 ms detecting pulmonary hypertension with a sensitivity of 75% and specificity of 94.8%.

  14. Observation of a discrete time crystal.

    PubMed

    Zhang, J; Hess, P W; Kyprianidis, A; Becker, P; Lee, A; Smith, J; Pagano, G; Potirniche, I-D; Potter, A C; Vishwanath, A; Yao, N Y; Monroe, C

    2017-03-08

    Spontaneous symmetry breaking is a fundamental concept in many areas of physics, including cosmology, particle physics and condensed matter. An example is the breaking of spatial translational symmetry, which underlies the formation of crystals and the phase transition from liquid to solid. Using the analogy of crystals in space, the breaking of translational symmetry in time and the emergence of a 'time crystal' was recently proposed, but was later shown to be forbidden in thermal equilibrium. However, non-equilibrium Floquet systems, which are subject to a periodic drive, can exhibit persistent time correlations at an emergent subharmonic frequency. This new phase of matter has been dubbed a 'discrete time crystal'. Here we present the experimental observation of a discrete time crystal, in an interacting spin chain of trapped atomic ions. We apply a periodic Hamiltonian to the system under many-body localization conditions, and observe a subharmonic temporal response that is robust to external perturbations. The observation of such a time crystal opens the door to the study of systems with long-range spatio-temporal correlations and novel phases of matter that emerge under intrinsically non-equilibrium conditions.

  15. Observation of a discrete time crystal

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Hess, P. W.; Kyprianidis, A.; Becker, P.; Lee, A.; Smith, J.; Pagano, G.; Potirniche, I.-D.; Potter, A. C.; Vishwanath, A.; Yao, N. Y.; Monroe, C.

    2017-03-01

    Spontaneous symmetry breaking is a fundamental concept in many areas of physics, including cosmology, particle physics and condensed matter. An example is the breaking of spatial translational symmetry, which underlies the formation of crystals and the phase transition from liquid to solid. Using the analogy of crystals in space, the breaking of translational symmetry in time and the emergence of a ‘time crystal’ was recently proposed, but was later shown to be forbidden in thermal equilibrium. However, non-equilibrium Floquet systems, which are subject to a periodic drive, can exhibit persistent time correlations at an emergent subharmonic frequency. This new phase of matter has been dubbed a ‘discrete time crystal’. Here we present the experimental observation of a discrete time crystal, in an interacting spin chain of trapped atomic ions. We apply a periodic Hamiltonian to the system under many-body localization conditions, and observe a subharmonic temporal response that is robust to external perturbations. The observation of such a time crystal opens the door to the study of systems with long-range spatio-temporal correlations and novel phases of matter that emerge under intrinsically non-equilibrium conditions.

  16. Transit Timing Observations from Kepler: III. Confirmation of 4 Multiple Planet Systems by a Fourier-Domain Study of Anti-correlated Transit Timing Variations

    SciTech Connect

    Steffen, Jason H.; Fabrycky, Daniel C.; Ford, Eric B.; Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Lissauer, Jack J.; Rowe, Jason F.; Ragozzine, Darin; Welsh, William F.; Borucki, William J.; /NASA, Ames /UC, Santa Barbara

    2012-01-01

    We present a method to confirm the planetary nature of objects in systems with multiple transiting exoplanet candidates. This method involves a Fourier-domain analysis of the deviations in the transit times from a constant period that result from dynamical interactions within the system. The combination of observed anticorrelations in the transit times and mass constraints from dynamical stability allow us to claim the discovery of four planetary systems, Kepler-25, Kepler-26, Kepler-27 and Kepler-28, containing eight planets and one additional planet candidate.

  17. An observational study of night time aerosol concentrations in the lower atmosphere at a tropical coastal station

    NASA Astrophysics Data System (ADS)

    Parameswaran, K.; Rajeev, K.; Sen Gupta, K.

    1997-09-01

    Aerosol number densities in the lower troposphere measured by a bistatic CW lidar are used to study their altitude structure in the nocturnal mixing region and its association with stratified turbulence. In the early night hours the aerosol concentration shows a maximum just above the daytime Thermal Internal Boundary Layer. This maximum disappears in the late night hours. The integrated aerosol content in the first 1 km shows a general decrease during the post-midnight hours. Stratified aerosol layers are observed in the nocturnal mixing region during the post-midnight period. The association between these stratified aerosol layers and the prevailing atmospheric stability condition in this region is studied using the altitude profiles of different meteorological parameters obtained from pilot balloon and tethered balloonsonde observations.

  18. Comparison of metoprolol succinate versus carvedilol in time to cardiovascular admission in a Veterans Affairs healthcare system: An observational study.

    PubMed

    Church, Kara M; Henalt, Robert; Baker, Errol; Smith, Gary L; Brennan, Michael T; Joseph, Jacob

    2015-12-01

    To determine if metoprolol succinate or carvedilol is more effective in delaying the time to first cardiovascular disease hospital admission in systolic heart failure patients. As a secondary objective, to determine the most effective dose of each agent in delaying first cardiovascular disease hospital admission, including but not limited to heart failure exacerbation, myocardial infarction, ischemic heart disease, cardiac arrhythmias, or death. This study was a retrospective chart review of 272 veterans at the VA Boston Healthcare System newly started on metoprolol succinate (n = 157) or carvedilol (n = 115) between January 2000 and December 2008. After an 8-week study medication titration period, subjects were subcategorized into low-, medium-, and high-dose ranging groups and followed until the first cardiovascular disease hospitalization, death, or 365 days. The main outcome measure was time to first cardiovascular hospitalization or death. The mean age (69.9 years vs. 67.9 years) and ejection fraction (26% vs. 25%) were comparable between study arms at baseline. Mean time to first cardiovascular disease hospitalization was significantly different (p = 0.001) between study groups with 330.6 days with in metoprolol succinate group vs. 282.6 days in the carvedilol groups. High-dose carvedilol significantly delayed time to first hospitalization in comparison to medium or low carvedilol doses (p = 0.015, p = 0.005). Low- and high-dose metoprolol succinate were not significantly different (p = 0.509) in time to first event, and both dosing groups fared better compared to medium dose metoprolol succinate (p = 0.046). In this veteran patient population in need of additional heart failure treatments, metoprolol succinate use resulted in a delayed time to first cardiovascular disease hospitalization or death compared to carvedilol. Both low and high doses of metoprolol succinate showed a significant delay of time to first cardiovascular hospitalization compared to

  19. The impact of home, work, and church environments on fat intake over time among rural residents: a longitudinal observational study.

    PubMed

    Haardörfer, Regine; Alcantara, Iris; Addison, Ann; Glanz, Karen; Kegler, Michelle C

    2016-01-29

    Dietary behaviors are influenced by many individual and environmental factors. This study explores how dietary fat intake in high-risk midlife adults living in the rural south is influenced by three behavior settings, i.e. in the home, at work, and at church. Self-report data were collected from rural African American or Caucasian adults age 40-70 at three time points at baseline, 6, and 12 months post baseline. Multilevel analyses investigated the impact of determinants of fat intake over time. Home and work environments varied significantly over time in regard to healthy eating while church environments remained stable. Age, gender, and self-efficacy for healthy eating were individual factors associated with fat intake. In the home, presence of more high fat items, a time-varying variable, was significant. In the work environment, having access to healthy foods as well as healthy eating programs has positive impact as did hearing healthy eating messages and availability of healthy foods at church. Understanding stability and variability of dietary fat intake from a social ecologic perspective will aid in identifying targets of change for intervention. Understanding which components of key behavior settings are dynamic and which are relatively stable will help to disentangle the complexity of multi-level determinants of dietary behavior.

  20. X ray timing observations and gravitational physics

    NASA Technical Reports Server (NTRS)

    Michelson, Peter F.; Wood, Kent S.

    1989-01-01

    Photon-rich x ray observations on bright compact galactic sources will make it possible to detect many fast processes that may occur in these systems on millisecond and submillisecond timescales. Many of these processes are of direct relevance to gravitational physics because they arise in regions of strong gravity near neutron stars and black holes where the dynamical timescales for compact objects of stellar mass are milliseconds. To date, such observations have been limited by the detector area and telemetry rates available. However, instruments such as the proposed X ray Large Array (XLA) would achieve collecting areas of about 100 sq m. This instrument has been described elsewhere (Wood and Michelson 1988) and was the subject of a recent prephase A feasibility study at Marshall Space Flight Center. Observations with an XLA class instrument will directly impact five primary areas of astrophysics research: the attempt to detect gravitational radiation, the study of black holes, the physics of mass accretion onto compact objects, the structure of neutron stars and nuclear matter, and the characterization of dark matter in the universe. Those observations are discussed that are most directly relevant to gravitational physics: the search for millisecond x ray pulsars that are potential sources of continuous gravitational radiation; and the use of x ray timing observations to probe the physical conditions in extreme relativistic regions of space near black holes, both stellar-sized and supermassive.

  1. Time to begin adjuvant chemotherapy and survival in breast cancer patients: a retrospective observational study using latent class analysis.

    PubMed

    Downing, Amy; Twelves, Christopher; Forman, David; Lawrence, Gill; Gilthorpe, Mark S

    2014-01-01

    The analysis of time to treatment data and the evaluation of subsequent effects on health outcomes can be complex due to the nature of the data and the relationships amongst the variables. This study proposes an alternative method of analyzing such data using latent class analysis (LCA). The association between time to begin adjuvant chemotherapy after breast cancer surgery and survival was investigated using both "traditional" regression analysis and LCA. Women with breast cancer undergoing surgery and subsequent adjuvant chemotherapy in two English regions between January 01, 1998 and December 31, 2004 were identified from a linked cancer registry-Hospital Episode Statistics dataset (n = 10,366). Patient, tumor, and treatment information were extracted. A Cox proportional hazards model was used to analyze 5-year survival using regression analysis and LCA. Using "traditional" regression analysis, women beginning chemotherapy >10 weeks after surgery had worse survival in region 1 (HR = 1.49, 95% CI 1.13-1.95 compared to <3 weeks) but not region 2. LCA split the women into three groups representing short, medium, and long waits. The median time to begin chemotherapy in the "long" wait group was 70 (region 1) and 57 (region 2) days. In this group, increased time to begin chemotherapy was associated with worse survival (region 1 HR = 1.15, 95% CI 1.11-1.18; region 2 HR = 1.08, 95% CI 1.03-1.13 per week increase). LCA identified a group of 13-15% of women for whom a longer time to begin chemotherapy had an adverse effect on survival. This methodology provides an excellent framework in which to examine complex associations between the delivery of patient care and patient outcomes. © 2013 Wiley Periodicals, Inc.

  2. Child Posture and Shoulder Belt Fit During Extended Night-Time Traveling: An In-Transit Observational Study.

    PubMed Central

    Forman, Jason L.; Segui-Gomez, Maria; Ash, Joseph H.; Lopez-Valdes, Francisco J.

    2011-01-01

    Understanding pediatric occupant postures can help researchers indentify injury risk factors, and provide information for prospective injury prediction. This study sought to observe lateral head positions and shoulder belt fit among older child automobile occupants during a scenario likely to result in sleeping - extended travel during the night. An observational, volunteer, in-transit study was performed with 30 pediatric rear-seat passengers, ages 7 to 14. Each was restrained by a three-point seatbelt and was driven for seventy-five minutes at night. Ten subjects used a high-back booster seat, ten used a low-back booster seat, and ten used none (based on the subject height and weight). The subjects were recorded with a low-light video camera, and one frame was analyzed per each minute of video. The high-back booster group exhibited a statistically significant (p<0.05) decrease in the mean frequency of poor shoulder belt fit compared to the no-booster and low-back booster groups. The high-back booster group also exhibited statistically significant decreases in the 90th percentile of the absolute value of the relative lateral motion of the head. The low-back booster group did not result in statistically significant decreases in poor shoulder belt fit or lateral head motion compared to the no-booster group. These results are consistent with the presence of large lateral supports of the high-back booster which provided support to the head while sleeping, reducing voluntary lateral occupant motion and improving shoulder belt fit. Future work includes examining lap belt fit in-transit, and examining the effects of these observations on predicted injury risk. PMID:22105378

  3. The Prospective, Observational, Multicenter, Major Trauma Transfusion (PROMMTT) Study: Comparative Effectiveness of a Time-varying Treatment with Competing Risks

    PubMed Central

    Holcomb, John B.; del Junco, Deborah J.; Fox, Erin E.; Wade, Charles E.; Cohen, Mitchell J.; Schreiber, Martin A.; Alarcon, Louis H.; Bai, Yu; Brasel, Karen J.; Bulger, Eileen M.; Cotton, Bryan A.; Matijevic, Nena; Muskat, Peter; Myers, John G.; Phelan, Herb A.; White, Christopher E.; Zhang, Jiajie; Rahbar, Mohammad H.

    2013-01-01

    Context Hemorrhagic shock is the leading potentially preventable cause of death after injury. Transfusion of early and increased ratios of plasma and platelets to red blood cells (RBCs) has been associated with decreased mortality; however conflicting reports and the time-varying nature of transfusions and hemorrhagic death raise concern for the validity of the clinical conclusions drawn from the retrospective data. Objective To relate in-hospital mortality to: 1) early transfusion of plasma and/or platelets and 2) time-varying plasma:RBC and platelet:RBC ratios. Design Prospective cohort study documenting the timing of transfusions during active resuscitation and patient outcomes. Data were analyzed using time-dependent proportional hazards models. Setting Ten US Level 1 trauma centers. Patients Adult trauma patients surviving for 30 minutes after admission, transfused at least 1 unit RBC within 6 hours of admission (n=1245, the original study group) and at least 3 total units (of RBC, plasma or platelets) within 24 hours (n=905, the analysis group). Main outcome measure In-hospital mortality Results Plasma:RBC and platelet:RBC ratios were not constant over the first 24 hours (p<.001 for both). In a multivariable time-dependent Cox model, increased ratios of plasma:RBC (adjusted hazard ratio, HR=0.31, 95% CI=0.16–0.58) and platelets:RBC (adjusted HR=0.55, 95% CI=0.31–0.98) were independently associated with decreased 6-hour mortality, when hemorrhagic death predominated. In the first 6 hours, patients with ratios < 1:2 were 3–4 times more likely to die than patients with ratios ≥1:1. After 24 hours, plasma and platelet ratios were unassociated with mortality, when competing risks from non-hemorrhagic causes prevailed. Conclusions Higher plasma and platelet ratios early in resuscitation were associated with decreased mortality in patients transfused at least three units of blood products during the first 24 hours after admission. Among survivors at 24 hours

  4. Time trends in drug resistant HIV-1 infections in the United Kingdom up to 2009: multicentre observational study.

    PubMed

    Dolling, David; Sabin, Caroline; Delpech, Valerie; Smit, Erasmus; Pozniak, Anton; Asboe, David; Brown, Andrew Leigh; Churchill, Duncan; Williams, Ian; Geretti, Anna Maria; Phillips, Andrew; Mackie, Nicola; Murphy, Gary; Castro, Hannah; Pillay, Deenan; Cane, Patricia; Dunn, David; Dolling, David

    2012-08-21

    To evaluate whether the prevalence of HIV-1 transmitted drug resistance has continued to decline in infections probably acquired within the United Kingdom. Multicentre observational study. All UK public laboratories conducting tests for genotypic HIV resistance as a part of routine care. 14,584 patients infected with HIV-1 subtype B virus, who were first tested for resistance before receiving antiretroviral therapy between January 2002 and December 2009. Prevalence of transmitted drug resistance, defined as one or more resistance mutations from the surveillance list recommended by the World Health Organization. 1654 (11.3%, 95% confidence interval 10.8% to 11.9%) patients had one or more mutations associated with transmitted HIV-1 drug resistance; prevalence was found to decline from 15.5% in 2002 to 9.6% in 2007, followed by a slight increase to 10.9% in 2009 (P=0.21). This later rise was mainly a result of increases in resistance to nucleos(t)ide reverse transcriptase inhibitors (from 5.4% in 2007 to 6.6% in 2009, P=0.24) and protease inhibitors (1.5% to 2.1%, P=0.12). Thymidine analogue mutations, including T215 revertants, remained the most frequent mutations associated with nucleos(t)ide reverse transcriptase inhibitors, despite a considerable fall in stavudine and zidovudine use between 2002 and 2009 (from 29.4% of drug regimens in 2002 to 0.8% in 2009, from 47.9% to 8.8%, respectively). The previously observed decline in the prevalence of transmitted drug resistance in HIV-1 infections probably acquired in the UK seems to have stabilised. The continued high prevalence of thymidine analogue mutations suggests that the source of this resistance may be increasingly from patients who have not undergone antiretroviral therapy and who harbour resistant viruses. Testing of all newly diagnosed HIV-1 positive people should be continued.

  5. Impacts of the 2011 Fukushima nuclear accident on emergency medical service times in Soma District, Japan: a retrospective observational study

    PubMed Central

    Morita, Tomohiro; Furutani, Tomoyuki; Nomura, Shuhei; Leppold, Claire; Takahara, Kazuhiro; Shimada, Yuki; Fujioka, Sho; Kami, Masahiro; Kato, Shigeaki; Oikawa, Tomoyoshi

    2016-01-01

    Objective To assess the influence of the 3.11 triple disaster (earthquake, tsunami and nuclear accident) on the emergency medical service (EMS) system in Fukushima. Methods Total EMS time (from EMS call to arrival at a hospital) was assessed in the EMS system of Soma district, located 10–40 km north of the nuclear plant, from 11 March to 31 December 2011. We defined the affected period as when total EMS time was significantly extended after the disasters compared with the historical control data from 1 January 2009 to 10 March 2011. To identify risk factors associated with the extension of total EMS time after the disasters, we investigated trends in 3 time segments of total EMS time; response time, defined as time from an EMS call to arrival at the location, on-scene time, defined as time from arrival at the location to departure, and transport time, defined as time from departure from the location to arrival at a hospital. Results For the affected period from week 0 to week 11, the median total EMS time was 36 (IQR 27–52) minutes, while that in the predisaster control period was 31 (IQR 24–40) min. The percentage of transports exceeding 60 min in total EMS time increased from 8.2% (584/7087) in the control period to 22.2% (151/679) in the affected period. Among the 3 time segments, there was the most change in transport time (standardised mean difference: 0.41 vs 0.13–0.17). Conclusions EMS transport was significantly delayed for ∼3 months, from week 1 to 11 after the 3.11 triple disaster. This delay may be attributed to malfunctioning emergency hospitals after the triple disaster. PMID:27683521

  6. Real-time patterns of smoking and alcohol use: an observational study protocol of risky-drinking smokers.

    PubMed

    Cohn, Amy; Brandon, Thomas; Armeli, Stephen; Ehlke, Sarah; Bowers, Molly

    2015-01-06

    Despite the strong relationship between smoking and health-related consequences, very few smokers quit. Heavy drinking is a significant risk factor for health consequences, and is implicated in persistent smoking and less success at quitting smoking. Self-efficacy (SE) to abstain from smoking is an important determinant of smoking outcomes and may link alcohol use to poor quit rates. Even though research has demonstrated a strong association between drinking and smoking, and the multiplicative effect of these substances on cancer-related, heavy-drinking smokers has been largely ignored in the literature. Further, research has not taken advantage of innovative methods, such as ecological momentary assessment, to capture the impact of daily factors on smoking cessation outcomes in this particular group. The proposed study identifies daily changing factors that impede or promote SE and future smoking cessation efforts in risky-drinking smokers. This is an observational study of 84 regular smokers (≥10 cigarettes per day) who drink at risky levels, report a desire to quit in the next 6 months, and show no evidence of psychiatric disturbance, severe history of alcohol withdrawal or drug dependence (excluding nicotine and caffeine). Participants report on their smoking, alcohol consumption and SE related to smoking twice a day for 28 days using interactive voice response (IVR) surveys. Multilevel regression and path models will examine within-person daily associations among drinking, smoking and SE, and how these variables predict the likelihood of future smoking behaviour at 1 and 6 months follow-up. This protocol was approved by an accredited Institutional Review Board. The findings will help us understand the factors that promote or impede smoking cessation among a high-risk group of smokers (heavy-drinking smokers) and will be disseminated through peer-reviewed journal articles and presentations at national conferences. Published by the BMJ Publishing Group

  7. Prognosis and serum creatinine levels in acute renal failure at the time of nephrology consultation: an observational cohort study

    PubMed Central

    Perez-Valdivieso, Jose Ramon; Bes-Rastrollo, Maira; Monedero, Pablo; de Irala, Jokin; Lavilla, Francisco Javier

    2007-01-01

    Background The aim of this study is to evaluate the association between acute serum creatinine changes in acute renal failure (ARF), before specialized treatment begins, and in-hospital mortality, recovery of renal function, and overall mortality at 6 months, on an equal degree of ARF severity, using the RIFLE criteria, and comorbid illnesses. Methods Prospective cohort study of 1008 consecutive patients who had been diagnosed as having ARF, and had been admitted in an university-affiliated hospital over 10 years. Demographic, clinical information and outcomes were measured. After that, 646 patients who had presented enough increment in serum creatinine to qualify for the RIFLE criteria were included for subsequent analysis. The population was divided into two groups using the median serum creatinine change (101%) as the cut-off value. Multivariate non-conditional logistic and linear regression models were used. Results A ≥ 101% increment of creatinine respect to its baseline before nephrology consultation was associated with significant increase of in-hospital mortality (35.6% vs. 22.6%, p < 0.001), with an adjusted odds ratio of 1.81 (95% CI: 1.08–3.03). Patients who required continuous renal replacement therapy in the ≥ 101% increment group presented a higher increase of in-hospital mortality (62.7% vs 46.4%, p = 0.048), with an adjusted odds ratio of 2.66 (95% CI: 1.00–7.21). Patients in the ≥ 101% increment group had a higher mean serum creatinine level with respect to their baseline level (114.72% vs. 37.96%) at hospital discharge. This was an adjusted 48.92% (95% CI: 13.05–84.79) more serum creatinine than in the < 101% increment group. Conclusion In this cohort, patients who had presented an increment in serum level of creatinine of ≥ 101% with respect to basal values, at the time of nephrology consultation, had increased mortality rates and were discharged from hospital with a more deteriorated renal function than those with similar Liano

  8. Asteroidal occultation timed by four UK observers

    NASA Astrophysics Data System (ADS)

    McGee, H.

    2000-04-01

    The occultation of a 9th magnitude star by the minor planet (49) Pales at 01.00 on Monday January 17 was the first such event to be timed by more than one observer at different locations on the track in the UK (see Figure 1). It was also seen from Hungary, and by three sets of observers in Canada and the USA, but unfortunately heavy cloud prevented observation across most of Europe.

  9. Assessing potentially time-dependent treatment effect from clinical trials and observational studies for survival data, with applications to the Women's Health Initiative combined hormone therapy trial.

    PubMed

    Yang, Song; Prentice, Ross L

    2015-05-20

    For risk and benefit assessment in clinical trials and observational studies with time-to-event data, the Cox model has usually been the model of choice. When the hazards are possibly non-proportional, a piece-wise Cox model over a partition of the time axis may be considered. Here, we propose to analyze clinical trials or observational studies with time-to-event data using a certain semiparametric model. The model allows for a time-dependent treatment effect. It includes the important proportional hazards model as a sub-model and can accommodate various patterns of time-dependence of the hazard ratio. After estimation of the model parameters using a pseudo-likelihood approach, simultaneous confidence intervals for the hazard ratio function are established using a Monte Carlo method to assess the time-varying pattern of the treatment effect. To assess the overall treatment effect, estimated average hazard ratio and its confidence intervals are also obtained. The proposed methods are applied to data from the Women's Health Initiative. To compare the Women's Health Initiative clinical trial and observational study, we use the propensity score in building the regression model. Compared with the piece-wise Cox model, the proposed model yields a better model fit and does not require partitioning of the time axis. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Observing Reality on Different Time Scales

    NASA Astrophysics Data System (ADS)

    Alyushin, Alexey

    2005-10-01

    In the first part of the paper, I examine cases of acceleration of perception and cognition and provide my explanation of the mechanism of the effect. The explanation rests on the conception of neuronal temporal frames, or windows of simultaneity. Frames have different standard durations and yield to stretching and compressing. I suggest it to be the cause of the effect, as well as the ground for differences in perceptive time scales of living beings. In the second part, I apply the conception of temporal frames to model observation in the extended time scales that reach far beyond the temporal perceptive niche of individual living beings. Duration of a frame is taken as the basic parameter setting a particular time scale. By substituting a different frame duration, we set a hypothetical time scale and emulate observing reality in a wider or a narrower angle of embracing events in time. I discuss the status of observer in its relation to objective reality, and examine how reality does change its appearance when observed in different time scales.

  11. Effect of timing of first postnatal care home visit on neonatal mortality in Bangladesh: a observational cohort study

    PubMed Central

    Ahmed, Saifuddin; Arifeen, Shams El; Darmstadt, Gary L; Rosecrans, Amanda M; Mannan, Ishtiaq; Rahman, Syed M; Begum, Nazma; Mahmud, Arif B A; Seraji, Habibur R; Williams, Emma K; Winch, Peter J; Santosham, Mathuram; Black, Robert E

    2009-01-01

    Objective To assess the effect of the timing of first postnatal home visit by community health workers on neonatal mortality. Design Analysis of prospectively collected data using time varying discrete hazard models to estimate hazard ratios for neonatal mortality according to day of first postnatal home visit. Data source Data from a community based trial of neonatal care interventions conducted in Bangladesh during 2004-5. Main outcome measure Neonatal mortality. Results 9211 live births were included. Among infants who survived the first day of life, neonatal mortality was 67% lower in those who received a visit on day one than in those who received no visit (adjusted hazard ratio 0.33, 95% confidence interval 0.23 to 0.46; P<0.001). For those infants who survived the first two days of life, receiving the first visit on the second day was associated with a 64% lower neonatal mortality than in those who did not receive a visit (adjusted hazard ratio 0.36, 0.23 to 0.55; P<0.001). First visits on any day after the second day of life were not associated with reduced mortality. Conclusions In developing countries, especially where home delivery with unskilled attendants is common, postnatal home visits within the first two days of life by trained community health workers can significantly reduce neonatal mortality. PMID:19684100

  12. {GUVI} Observations of Night Time Ionospheric Morphology

    NASA Astrophysics Data System (ADS)

    Swenson, C. M.; Christensen, A. B.; Walterscheid, R. J.; Paxton, L. J.; Meng, C. I.; Craven, J. D.; Meier, R. R.; Strickland, D. J.; Crowley, G.

    2002-05-01

    The TIMED spacecraft is currently mapping the nighttime Earth disk and limb with the Global Ultraviolet Imager (GUVI). Images are made in the OI 135.6 nm line which is excited by the recombination of O+ ions. The intensity in these disk images is related to the total electron content of the ionosphere and density profiles can be recovered from the limb scans. Prominent in these images are UV signatures of the Equatorial Anomaly that was first imaged by the DE-1 satellite. Data is currently available from essentially the same local time and is suitable for the study of the longitudinal dependence of the Anomalies. It is known that the Earth's ionosphere shows the occurrence large longitudinal and latitudinal variations in the F-region plasma density that change with season and solar cycle. These plasma density fluctuations occur over a very large range of scale sizes and have been observed by for about three decades by satellites [e.g., ISIS 2, ESRO-4, Atmosphere Explorers, Dynamics Explorer-2, San Marco II, DMSP, etc.]. Their morphology, origin, day-to-day variability, and predictability are still not well understood. The GUVI night data that gives insight into these largest scale structures will be discussed.

  13. Reasons and pathways of first-time consultations at child and adolescent mental health services in Italy: an observational study.

    PubMed

    Pedrini, Laura; Sisti, Davide; Tiberti, Alessandra; Preti, Antonio; Fabiani, Michela; Ferraresi, Linda; Palazzi, Stefano; Parisi, Roberto; Ricciutello, Cosimo; Rocchi, Marco B L; Squarcia, Antonella; Trebbi, Stefano; Tullini, Andrea; De Girolamo, Giovanni

    2015-01-01

    An increasing number of young people have made contact with the Child and Adolescent Mental Health Services (CAMHS). However, only a small proportion of the population with emotional problems, actually seek specialized care. Research concerning the help-seeking process and pathways to care of a clinical sample could help to develop effective health policies to facilitate access to specialized care. To analyze the access pattern for CAMHS, reasons of contact and care pathways of a consecutive sample of first-time patients. Our aim was to analyze the association between source of referral, socio-demographic and clinical variables. Standardized assessment instruments and information concerning access patterns and care pathways were collected from 399 patients at first-time contact with CAMHS in a Northern Italian Region. Most patients were referred to CAMHS by school teachers (36 %) or health professionals (32 %), while only 17 % of the parents sought help by themselves. School issues (50 %) and emotional problems (17 %) were the most frequent reasons for contact. The proportion of first-time contacts with no diagnosis of mental disorder at their first consultation did not differ by source of referral. Parents of children who did not receive a clinical diagnosis of mental disorders described them as "psychosocially impaired" and their condition as "clinically severe" likewise parents of patients who received a psychiatric diagnosis. Patients with externalizing problems were more frequently referred by the parents themselves, while youth with internalizing problems were more often referred through health professionals. Families with non-traditional structures (adoptive, foster care, mono-parental) were more likely to consult CAMHS directly, while immigrant youth were more often referred by teachers. Socio-demographic and clinical characteristics can affect pathways to care. To improve early access to care for children and adolescents with ongoing mental disorders

  14. Correlation between T2* (T2 star) relaxation time and cervical intervertebral disc degeneration: An observational study.

    PubMed

    Huang, Minghua; Guo, Yong; Ye, Qiong; Chen, Lei; Zhou, Kai; Wang, Qingjun; Shao, Lixin; Shi, Qinglei; Chen, Chun

    2016-11-01

    To demonstrate the potential benefits of T2 relaxation time of intervertebral discs (IVDs) regarding the detection and grading of degenerative disc disease using 3.0-T magnetic resonance imaging (MRI) in a clinical setting. Cervical sagittal T2-weighted, T2 relaxation MRI was performed at 3.0-T in 61 subjects, covering discs C2-3 to C6-7. All discs were morphologically assessed based on the Pfirrmann grade, and regions of interests (ROIs) were drawn over the T2 mapping. Receiver operating characteristic (ROC) analysis was performed among grades to determine the cut-off values. Cervical intervertebral discs (IVDs) of patients were commonly determined to be at Pfirrmann grades III to V. The nucleus pulposus (NP) values did not differ significantly between sexes at the same anatomic level (P > 0.05). In the NP, the T2 values tended to decrease with increasing grade (P < 0.000), and a significant difference was found in the T2 values between grades I to V (P < 0.05). T2 values based on disc degeneration level classification were as follows: grade I (>30 milliseconds), grade II (24.55-29.99 milliseconds), grade III (21.65-24.54 milliseconds), grade IV (18.35-21.64 milliseconds), and grade V (<18.34 milliseconds). Our standardized method of region-specific quantitative T2 relaxation time evaluation seems capable of characterizing different degrees of disc degeneration quantitatively. The T2 values obtained in these cervical IVDs may serve as baseline values for future T2 measurements in both healthy and degenerated cervical discs.

  15. Equilibration Time Scales of Physically Relevant Observables

    NASA Astrophysics Data System (ADS)

    García-Pintos, Luis Pedro; Linden, Noah; Malabarba, Artur S. L.; Short, Anthony J.; Winter, Andreas

    2017-07-01

    We address the problem of understanding, from first principles, the conditions under which a quantum system equilibrates rapidly with respect to a concrete observable. On the one hand, previously known general upper bounds on the time scales of equilibration were unrealistically long, with times scaling linearly with the dimension of the Hilbert space. These bounds proved to be tight since particular constructions of observables scaling in this way were found. On the other hand, the computed equilibration time scales for certain classes of typical measurements, or under the evolution of typical Hamiltonians, are unrealistically short. However, most physically relevant situations fall outside these two classes. In this paper, we provide a new upper bound on the equilibration time scales which, under some physically reasonable conditions, give much more realistic results than previously known. In particular, we apply this result to the paradigmatic case of a system interacting with a thermal bath, where we obtain an upper bound for the equilibration time scale independent of the size of the bath. In this way, we find general conditions that single out observables with realistic equilibration times within a physically relevant setup.

  16. Precise Landslide Displacement Time Series from Continuous GPS Observations in Tectonically Active and Cold Regions: A Case Study in Alaska

    NASA Astrophysics Data System (ADS)

    Cuddus, Y.; Wang, G.

    2014-12-01

    Over the past 15 years, Global Positioning System (GPS) has been frequently used as a scientific tool to detect potential earth mass movements and to track creeping landslides. In this study, we investigated four-years of continuous GPS data (September 2006-July 2010) recorded at a landslide site in Alaska. This GPS station (AC55) was installed on an un-identified creeping site by the Plate Boundary Observatory (PBO) project, which was funded by the U.S. National Science Foundation. The landslide moves with a steady horizontal velocity of 5.5 cm/year toward NEE, and had a subsidence rate of 2.6 cm/year. There was a considerable correlation between annual snow loading and melting cycles and seasonal variations of the landslide displacements. The seasonal movements vary year to year with an average peak-to-peak amplitude of 1.5 cm and 1.0 cm in horizontal and vertical directions, respectively. This study addresses three challenging issues in applying GPS for landslide monitoring in tectonically active and cold regions. The three challenges include (1) detecting GPS-derived positions that could be contaminated by the snow and ice accumulated on GPS antennas during cold seasons, (2) establishing a precise local reference frame and assessing its accuracy, and (3) excluding local seasonal ground motions from GPS-derived landslide displacements. The methods introduced in this study will be useful for GPS landslide monitoring in other tectonically active and/or cold regions.

  17. Skylab Earth Observation Studies

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This concept illustrates Skylab Earth observation studies, an Earth Resources Experiment Package (EREP). EREP was designed to explore the use of the widest possible portion of the electromagnetic spectrum for Earth resource investigations with sensors that recorded data in the visible, infrared, and microwave spectral regions. Resources subject to this study included a capability of mapping Earth resources and land uses, crop and forestry cover, health of vegetation, types of soil, water storage in snow pack, surface or near-surface mineral deposits, sea surface temperature, and the location of likely feeding areas for fish, etc. A significant feature of EREP was the ability of man to operate the sensors in a laboratory fashion.

  18. Efficacy of a real time optoelectronic device (TruScreen™) in detecting cervical intraepithelial pathologies: a prospective observational study

    PubMed Central

    Özgü, Emre; Yıldız, Yunus; Özgü, Burçin Salman; Öz, Murat; Danışman, Nuri; Güngör, Tayfun

    2015-01-01

    Objective To assess the effect of TruScreen™ (an objective optoelectronic cervical screening device) in improving the sensitivity of cervical screening programs either alone or in combination with Papanicolaou (PAP) smear or human papilloma virus (HPV) DNA screening. Material and Methods Our study was performed in 285 patients with abnormal Pap test results. TruScreen™ and HPV screening methods were performed in all participants. Consistency and differences between the tests were compared with cervical biopsy results. Results TruScreen™ was found to be an approach method in the determination of cervical pathologies (ROC curve area underlined=0.606) and with an 89.5% negative predictive value. HPV screening remains a counterpart to TruScreen™ with a 0.620 area underlined in the ROC curve and an 83% negative predictive value. Conclusion As determined in our study, TruScreen™ with a sensitivity of 86.1% can be used as a screening test with instant and not professional dependent results for cervical cancer screening. Avoiding from subjectivity in interpretation of Pap smears and requirement for pathologists, TruScreen™ can be a used for cervical cancer screening especially in countries with a low socio-economic status. The combination of TruScreen™ and HPV screening was not able to demonstrate a significant rise of effectiveness in screening. PMID:25788849

  19. The Impact of Heatwaves on Community Morbidity and Healthcare Usage: A Retrospective Observational Study Using Real-Time Syndromic Surveillance

    PubMed Central

    Smith, Sue; Elliot, Alex J.; Hajat, Shakoor; Bone, Angie; Bates, Chris; Smith, Gillian E.; Kovats, Sari

    2016-01-01

    We investigated the impact of a moderate heatwave on a range of presenting morbidities in England. Asthma, difficulty breathing, cerebrovascular accident, and cardiovascular symptoms were analysed using general practitioner in hours (GPIH), out of hours (GPOOH) and emergency department (ED) syndromic surveillance systems. Data were stratified by age group and compared between a heatwave year (2013) and non-heatwave years (2012, 2014). Incidence rate ratios were calculated to estimate the differential impact of heatwave compared to non-heatwave summers: there were no apparent differences for the morbidities tested between the 2013 heatwave and non-heatwave years. A subset of GPIH data were used to study individuals at higher risk from heatwaves based on their pre-existing disease. Higher risk patients were not more likely to present at GPs or ED than other individuals. Comparing GPIH consultations and ED attendances for myocardial infarction/ischaemia (MI), there was evidence of a fall in the presentation of MI during the heatwave, which was particularly noted in the 65–74 years age group (and over 75 years in ED attendances). These results indicate the difficulty in identifying individuals at risk from non-fatal health effects of heatwaves and hot weather. PMID:26784214

  20. Stratospheric Transport Times From Observations and Models

    NASA Astrophysics Data System (ADS)

    Hoor, P. M.; Lelieveld, J.; Boenisch, H.; Joeckel, P.; Steil, B.; Bruehl, C.; Strahan, S.

    2007-12-01

    Transport time scales in the stratosphere are crucial to understand and calculate the effects of chemical active species on stratospheric chemistry. In general CO2 or SF6 have been used to calculate mean ages of air in the stratosphere, whereas shorter lived trace gases like CO are used to investigate cross tropopause transport and mixing on short time-scales close to the tropopause. Besides mean ages and their assocated mean trace gas mixing ratios at a given point in the atmosphere other quantities of the trace gas distributions can be used to constrain stratospheric transport times, such as variability and slope. In particular the younger part of the age spectrum needs to be constrained since it determines the extent to which shorter lived compounds can be transported into the stratosphere. We investigate transport times in the stratosphere based on observations of CO, N2O and CO2 and test a new approach to deduce transport times. For that purpose we compare observations from the ER-2 and other platforms. The approach is applied to global models (ECHAM5/MESSy, Combo GMI) to identify barriers as well as regions of rapid mixing and transport.

  1. All in a day's work: an observational study to quantify how and with whom doctors on hospital wards spend their time.

    PubMed

    Westbrook, Johanna I; Ampt, Amanda; Kearney, Leanne; Rob, Marilyn I

    2008-05-05

    To quantify time doctors in hospital wards spend on specific work tasks, and with health professionals and patients. Observational time and motion study. 400-bed teaching hospital in Sydney. 19 doctors (seven registrars, five residents, seven interns) in four wards were observed between 08:30 and 19:00 for a total of 151 hours between July and December 2006. Proportions of time in categories of work; proportions of tasks performed with health professionals and patients; proportions of tasks using specific information tools; rates of multitasking and interruptions. The greatest proportions of doctors' time were in professional communication (33%; 95% CI, 29%-38%); social activities, such as non-work communication and meal breaks (17%; 95% CI, 13%-21%), and indirect care, such as planning care (17%; 95% CI, 15%-19%). Multitasking involved 20% of time, and on average, doctors were interrupted every 21 minutes. Most tasks were completed with another doctor (56%; 95% CI, 55%-57%), while 24% (95% CI, 23%-25%) were undertaken alone and 15% (95% CI, 15%-16%) with a patient. Interns spent more time completing documentation and administrative tasks, and less time in direct care than residents and registrars. The time interns spent documenting (22%) was almost double the time they were engaged in direct patient care. Two-thirds of doctors' time was consumed by three work categories: professional communication, social activities and indirect care. Doctors on wards are interrupted at considerably lower rates than those in emergency and intensive care units. The results confirm interns' previously reported dissatisfaction with their level of administrative work and documentation.

  2. Direct observation of time reversal violation

    SciTech Connect

    Bernabeu, J.

    2013-06-12

    A direct evidence for Time Reversal Violation (TRV) means an experiment that, considered by itself, clearly shows TRV independent of, and unconnected to, the results for CP Violation. No existing result before the recent BABAR experiment with entangled neutral B mesons had demonstrated TRV in this sense. There is a unique opportunity for a search of TRV with unstable particles thanks to the Einstein-Podolsky-Rosen (EPR) Entanglement between the two neutral mesons in B, and PHI, Factories. The two quantum effects of the first decay as a filtering measurement and the transfer of information to the still living partner allow performing a genuine TRV asymmetry with the exchange of 'in' and 'out' states. With four independent TRV asymmetries, BABAR observes a large deviation of T-invariance with a statistical significance of 14 standard deviations, far more than needed to declare the result as a discovery. This is the first direct observation of TRV in the time evolution of any system.

  3. Direct observation of time reversal violation

    NASA Astrophysics Data System (ADS)

    Bernabéu, J.

    2013-06-01

    A direct evidence for Time Reversal Violation (TRV) means an experiment that, considered by itself, clearly shows TRV independent of, and unconnected to, the results for CP Violation. No existing result before the recent BABAR experiment with entangled neutral B mesons had demonstrated TRV in this sense. There is a unique opportunity for a search of TRV with unstable particles thanks to the Einstein-Podolsky-Rosen (EPR) Entanglement between the two neutral mesons in B, and PHI, Factories. The two quantum effects of the first decay as a filtering measurement and the transfer of information to the still living partner allow performing a genuine TRV asymmetry with the exchange of "in" and "out" states. With four independent TRV asymmetries, BABAR observes a large deviation of T-invariance with a statistical significance of 14 standard deviations, far more than needed to declare the result as a discovery. This is the first direct observation of TRV in the time evolution of any system.

  4. Phase Behavior and Implications for Travel time Observables (PHASE 2)

    DTIC Science & Technology

    2015-09-30

    Phase behavior and implications for travel-time observables (PHASE-2) Emmanuel Skarsoulis Foundation for Research and Technology Hellas...perturbation behavior of travel time observables due to sound-speed perturbations. OBJECTIVES The objective is to study the behavior of the wave-theoretic... observables , peak and demodulated phase arrival times in particular, is similar or dissimilar depending of the behavior, the stationarity/non-stationarity

  5. Automatic time-lapse instrument is superior to single-point morphology observation for selecting viable embryos: retrospective study in oocyte donation.

    PubMed

    Aparicio-Ruiz, Belén; Basile, Natalia; Pérez Albalá, Sonia; Bronet, Fernando; Remohí, José; Meseguer, Marcos

    2016-11-01

    To correlate the different categories provided by a commercial diagnostic test with blastocyst formation, quality, implantation potential, and ongoing pregnancy (OPR) for the purpose of validating the automatic annotations and the classification algorithm. Observational, retrospective, multicenter cohort study. University-affiliated private IVF center. A total of 3,002 embryos, including 521 transferred embryos with known implantation, from 626 IVF cycles that were incubated in a conventional incubator and monitored with an automatic time-lapse test. None. Embryo selection was based on morphology and the classification provided by a commercial diagnostic test. Implantation was the primary end point, and OPR, blastocyst formation (BR), and embryo morphology were secondary end points. BR and number of optimal blastocysts were related to the classification test. This correlation was also observed when analyzing implantation rates (day 3 transfer: high 38.2%, medium 31.7% and low 26.1%; day 5 transfer: high 66.7%, medium 50%, low 31%). Patients where no high embryos were transferred (n = 75) had an OPR of 46.70%, and those patients where at least one high embryo was transferred (n = 109) significantly increased OPR to 67%. A logistic regression analysis studying other confounding factors (day of transfer, number of oocytes obtained, and embryo morphology classification) was included. In that model, if at least one of the embryos was labeled as high, OPR was 2.567 times higher than a cycle where no high embryos were transferred. Our study presents, to our knowledge, the largest set of transferred embryos after time-lapse analysis with the use of an automatic time-lapse test. The provided classification was related to reproductive outcome. Our results suggest that the automated embryo diagnostic test provided extra information to the embryologist to select the best embryos, independently from clinical features of the patient or day of transfer. Copyright © 2016 American

  6. Direct Observation of Thermal Equilibrium of Excited Triplet States of 9,10-Phenanthrenequinone. A Time-Resolved Resonance Raman Study.

    PubMed

    Kumar, Venkatraman Ravi; Rajkumar, Nagappan; Ariese, Freek; Umapathy, Siva

    2015-10-08

    The photochemistry of aromatic ketones plays a key role in various physicochemical and biological processes, and solvent polarity can be used to tune their triplet state properties. Therefore, a comprehensive analysis of the conformational structure and the solvent polarity induced energy level reordering of the two lowest triplet states of 9,10-phenanthrenequinone (PQ) was carried out using nanosecond-time-resolved absorption (ns-TRA), time-resolved resonance Raman (TR(3)) spectroscopy, and time dependent-density functional theory (TD-DFT) studies. The ns-TRA of PQ in acetonitrile displays two bands in the visible range, and these two bands decay with similar lifetime at least at longer time scales (μs). Interestingly, TR(3) spectra of these two bands indicate that the kinetics are different at shorter time scales (ns), while at longer time scales they followed the kinetics of ns-TRA spectra. Therefore, we report a real-time observation of the thermal equilibrium between the two lowest triplet excited states of PQ, assigned to nπ* and ππ* of which the ππ* triplet state is formed first through intersystem crossing. Despite the fact that these two states are energetically close and have a similar conformational structure supported by TD-DFT studies, the slow internal conversion (∼2 ns) between the T(2)(1(3)nπ*) and T(1)(1(3)ππ*) triplet states indicates a barrier. Insights from the singlet excited states of PQ in protic solvents [ J. Chem. Phys. 2015 , 142 , 24305 ] suggest that the lowest nπ* and ππ* triplet states should undergo hydrogen bond weakening and strengthening, respectively, relative to the ground state, and these mechanisms are substantiated by TD-DFT calculations. We also hypothesize that the different hydrogen bonding mechanisms exhibited by the two lowest singlet and triplet excited states of PQ could influence its ISC mechanism.

  7. Chrono-nutrition: a review of current evidence from observational studies on global trends in time-of-day of energy intake and its association with obesity.

    PubMed

    Almoosawi, S; Vingeliene, S; Karagounis, L G; Pot, G K

    2016-11-01

    The importance of the circadian rhythm in regulating human food intake behaviour and metabolism has long been recognised. However, little is known as to how energy intake is distributed over the day in existing populations, and its potential association with obesity. The present review describes global trends in time-of-day of energy intake in the general population based on data from cross-sectional surveys and longitudinal cohorts. Evidence of the association between time-of-day of energy intake and obesity is also summarised. Overall, there were a limited number of cross-sectional surveys and longitudinal cohorts that provided data on time-of-day of energy intake. In the identified studies, a wide variation in time-of-day of energy intake was observed, with patterns of energy distribution varying greatly by country and geographical area. In relation to obesity, eight cross-sectional surveys and two longitudinal cohorts were identified. The association between time-of-day of energy intake and obesity varied widely, with several studies reporting a positive link between evening energy intake and obesity. In conclusion, the current review summarises global trends in time-of-day of energy intake. The large variations across countries and global regions could have important implications to health, emphasising the need to understand the socio-environmental factors guiding such differences in eating patterns. Evidence of the association between time-of-day of energy intake and BMI also varied. Further larger scale collaborations between various countries and regions are needed to sum data from existing surveys and cohorts, and guide our understanding of the role of chrono-nutrition in health.

  8. Time course, outcome and management of adverse drug reactions associated with metformin from patient's perspective: a prospective, observational cohort study in the Netherlands.

    PubMed

    de Jong, Loek; Härmark, Linda; van Puijenbroek, Eugène

    2016-05-01

    The aim of this study was to gather information about frequency, latency time, outcome and management of frequently occurring adverse drug reactions (ADRs) related to the use of metformin in daily practice. A prospective, observational cohort study was performed. A total of 2490 first-time metformin users were recruited through pharmacies in the Netherlands between February 1, 2008, and April 1, 2012. Patients were invited to complete six web-based questionnaires at 2-week, 6-week, 3-month, 6-month, 9-month and 12-month intervals after starting treatment with metformin. Information was gathered about patient characteristics, ADRs and drug use. The occurrence of at least one possible ADR related to the use of metformin was reported by 34.5 % of the patients. A higher proportion of females reported the occurrence of an ADR (39.6 %) compared to the proportion in males (30.9 %). Some patients (11.4 %) stopped using metformin within 1 year after start. More than half of the patients (50.8 %) undertook no action regarding metformin after the occurrence of ADRs. A high number of patients (77.7 %) recovered or were still recovering from ADRs despite continuation of metformin. Most ADRs occurred shortly after the beginning of the treatment, with a median latency time of 1-6 days. The study revealed some ADR-specific differences in occurrence rate, latency time, management and outcome. This study successfully obtained information about frequency, latency time, outcome and management of frequently occurring ADRs related to the use of metformin in daily practise.

  9. Quality of Life and Timing of Stoma Closure in Patients With Rectal Cancer Undergoing Low Anterior Resection With Diverting Stoma: A Multicenter Longitudinal Observational Study.

    PubMed

    Herrle, Florian; Sandra-Petrescu, Flavius; Weiss, Christel; Post, Stefan; Runkel, Norbert; Kienle, Peter

    2016-04-01

    After low anterior resection for rectal cancer, creation of a diverting stoma is recommended. Data on the impact of a diverting stoma on quality of life are conflicting. Optimal timing of stoma closure in the setting of adjuvant chemotherapy is unclear. The purpose of this study was to investigate the impact of a diverting stoma on quality of life in patients undergoing rectal cancer resection before and after stoma closure. Furthermore, the study was conducted to look at the timing of stoma reversal and the potential influence of factors such as adjuvant chemotherapy. This was a longitudinal, observational, multicenter study. The study was conducted at 17 German colorectal centers. Patients with rectal cancer who planned for elective curative surgery with creation of temporary diverting stoma were included. This longitudinal observational study assessed quality of life at 3 occasions using European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core Questionnaire/Colorectal Cancer Module before cancer resection, before stoma closure, and 6 months after stoma closure. Furthermore, the timing of stoma closure and continence were evaluated. A total of 120 patients (64% men; mean age, 63.2 ± 11.5 years) were analyzed. Longitudinal global quality of life was not influenced by the presence of a stoma. Several functional and GI symptom scales were markedly impaired after stoma creation. Physical, role functioning, and sexual interest recovered after stoma closure. Social functioning stayed impaired (p < 0.0001). Median time to stoma closure was 5 months (range, 17 days to 18 months). A total of 3.4% of patients had very early stoma closure (within 30 days). Adjuvant chemotherapy delayed stoma closure (median, 5.6 vs 3.4 months without chemotherapy; p = 0.0001). The study was limited by its missing quality-of-life data for sexual function. The presence of a stoma had a negative impact on social functioning and GI symptoms. However, this

  10. Impact of preoperative fasting times on blood glucose concentration, ketone bodies and acid-base balance in children younger than 36 months: A prospective observational study.

    PubMed

    Dennhardt, Nils; Beck, Christiane; Huber, Dirk; Nickel, Katja; Sander, Björn; Witt, Lars-Henrik; Boethig, Dietmar; Sümpelmann, Robert

    2015-12-01

    In contrast to preoperative fasting guidelines in paediatric anaesthesia, actual fasting times are often too long. The objective of this study was to evaluate the effect of preoperative fasting on glucose concentration, ketone bodies and acid-base balance in children. A prospective, noninterventional, clinical observational study. A single-centre trial, study period from June 2014 to November 2014. One hundred children aged 0 to 36 months scheduled for elective paediatric surgery. Patient demographics, fasting times, haemodynamic data, glucose and ketone body concentrations, and acid-base parameters after induction of anaesthesia were documented using a standardised case report form. Mean fasting period was 7.8 ± 4.5 (3.5 to 20) h, and deviation from guideline (ΔGL) was 3.3 ± 3.2 (-2 to 14) h. Linear regression showed a significant correlation between fasting times and ketone bodies, anion gap, base excess, osmolality as well as bicarbonate (for each, P < 0.05), but not glucose or lactate. In children with ΔGL more than 2 h (54%), ketone bodies, osmolality and anion gap were significantly higher and base excess significantly lower than children with ΔGL less than 2 h (for each, P < 0.05). After prolonged preoperative fasting, children younger than 36 months can present with ketoacidosis and (low) normal blood glucose concentrations. Actual fasting times should be optimised according to existing guidelines. In small infants, deviations from fasting guidelines should be as short as possible and not longer than 2 h.

  11. Seismic Travel Time Study

    DTIC Science & Technology

    The report consists of an introduction in which is given a list of published papers on the travel times of body waves together with brief comments on...velocity distribution in the outer core have been based on the travel times of SKS. However, SKS arrivals can only be observed satisfactorily for arc

  12. [Prospective observational study of insulin detemir in patients with poorly controlled type 2 diabetes mellitus initiating insulin therapy for the first time (SOLVE Study)].

    PubMed

    Orozco-Beltrán, Domingo; Artola-Menéndez, Sara

    2016-02-01

    Describe the experience in the primary care setting with insulin detemir in patients with poorly controlled type2 diabetes mellitus that need to add-on insulin to their oral antidiabetic drug therapy. Prospective observational study of 6 months of follow up, performed in 10 countries. In Spain, participating sites were only from the primary care setting. Eligible patients were those with poorly controlled type2 diabetes mellitus adding-on once-daily insulin detemir to their existing oral antidiabetic therapy in the month prior to their enrollment. The change of Hb1Ac and of weight at the end of the study and the incidence of hypoglycemia and adverse reactions, were analyzed. We report the results obtained in the Spanish cohort. Overall 17,374 patients were included, 973 in Spain [mean age 64.8 years (SE 12); duration of diabetes 9.4 years (SE 6.2); Hb1Ac 8.9% (DE 1.4)]. In the sample analyzed for efficacy (n=474) the mean change of Hb1Ac was -1.6% (95%CI: -1.75 to -1.42; P<.001), mean change of weight was -2.9 kg (95%CI: -3.72 to -2.08; P<.001). Only one episode of severe hypoglycemia was reported, which was also the only serious adverse reaction reported in the study. The incidence rate of non-severe hypoglycemia was 2.44 events/patient-year. In this cohort of patients with type 2 diabetes mellitus receiving newly initiated insulin therapy, once-daily detemir improved the glycemic control, with low incidence of hypoglycemia and a significant reduction of the weight. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  13. A Real-World Observational Study of Time to Treatment Intensification Among Elderly Patients with Inadequately Controlled Type 2 Diabetes Mellitus

    PubMed Central

    Ajmera, Mayank; Raval, Amit; Zhou, Steve; Wei, Wenhui; Bhattacharya, Rituparna; Pan, Chunshen; Sambamoorthi, Usha

    2016-01-01

    BACKGROUND Among elderly patients, the management of type 2 diabetes mellitus (T2DM) is complicated by population heterogeneity and elderly-specific complexities. Few studies have been done to understand treatment intensification among elderly patients failing multiple oral antidiabetic drugs (OADs). OBJECTIVE To examine the association between time to treatment intensification of T2DM and elderly-specific patient complexities. METHODS In this observational, retrospective cohort study, elderly (aged ≥ 65 years) Medicare beneficiaries (n = 16,653) with inadequately controlled T2DM (hemoglobin A1c ≥ 8.0% despite 2 OADs) were included. Based on the consensus statement for diabetes care in elderly patients published by the American Diabetes Association and the American Geriatric Society, elderly-specific patient complexities were defined as the presence or absence of 5 geriatric syndromes: cognitive impairment; depression; falls and fall risk; polypharmacy; and urinary incontinence. RESULTS Overall, 48.7% of patients received intensified treatment during follow-up, with median time to intensification 18.5 months (95% CI = 17.7–19.3). Median time to treatment intensification was shorter for elderly patients with T2DM with polypharmacy (16.5 months) and falls and fall risk (12.7 months) versus those without polypharmacy (20.4 months) and no fall risk (18.6 months). Elderly patients with urinary incontinence had a longer median time to treatment intensification (18.6 months) versus those without urinary incontinence (14.6 months). The median time to treatment intensification did not significantly differ by the elderly-specific patient complexities that included cognitive impairment and depression. However, after adjusting for demographic, insurance, clinical characteristics, and health care utilization, we found that only polypharmacy was associated with time to treatment intensification (adjusted hazard ratio, 1.10; 95% CI = 1.04–1.15; P = 0.001). CONCLUSIONS

  14. Obtaining a male circumcision prevalence rate of 80% among adults in a short time: An observational prospective intervention study in the Orange Farm township of South Africa.

    PubMed

    Marshall, Esaie; Rain-Taljaard, Reathe; Tsepe, Motlalepule; Monkwe, Cornelius; Taljaard, Dirk; Hlatswayo, Florence; Xaba, Dumazile; Molomo, Tebogo; Lissouba, Pascale; Puren, Adrian; Auvert, Bertran

    2017-01-01

    World Health Organization recommends a target for the male circumcision prevalence rate of 80%. This rate will have a substantial impact on the human immunodeficiency virus-acquired immunodeficiency syndrome epidemic in Eastern and Southern Africa. The objective of the study was to assess whether an innovative intervention can lead to an increased voluntary male medical circumcision (VMMC) uptake among adults in a short time. This prospective observational study of a demand generation intervention was conducted in the township of Orange Farm (South Africa) in August to November 2015. In this community male circumcision prevalence rate among adults was stable between 2010 and 2015 at 55% and 57%, despite regular VMMC campaigns at community level and the presence of a VMMC clinic that offered free VMMC. The intervention took place in a random sample of 981 households where 522 men aged 18 to 49 years accepted to participate in the study. Among the 226 uncircumcised men, 212 accepted to be enrolled in the intervention study. A personal male circumcision adviser trained in interpersonal communication skills was assigned to each uncircumcised participant. The male circumcision advisers were trained to explain the risks and benefits of VMMC, and to discuss 24 possible reasons given by men for not being circumcised. Participants were then followed for 9 weeks. Each participant had a maximum of 3 motivational interviews at home. Participants who decided to be circumcised received financial compensation for their time equivalent to 2.5 days of work at the minimum South African salary rate. Among the 212 uncircumcised men enrolled in the intervention, 69.8% (148/212; 95% confidence interval [CI]; 63.4%-75.7%) agreed to be circumcised, which defines the uptake of the intervention. The male circumcision prevalence rate of the sample increased from 56.7% (296/522) to 81.4% (425/522; 77.9%-84.6%), P < 0.001, corresponding to a relative increase of 43.6% (95% CI: 35

  15. An observational near-infrared spectroscopy study on cerebral autoregulation in post-cardiac arrest patients: time to drop 'one-size-fits-all' hemodynamic targets?

    PubMed

    Ameloot, K; Genbrugge, C; Meex, I; Jans, F; Boer, W; Vander Laenen, M; Ferdinande, B; Mullens, W; Dupont, M; Dens, J; DeDeyne, C

    2015-05-01

    A subgroup of patients with ROSC after cardiac arrest (CA) with disturbed cerebral autoregulation might benefit from higher mean arterial pressures (MAP). We aimed to (1) phenotype patients with disturbed autoregulation, (2) investigate whether these patients have a worse prognosis, (3) define an individual optimal MAP per patient and (4) investigate whether time under this individual optimal MAP is associated with outcome. Prospective observational study in 51 post-CA patients monitored with near infrared spectroscopy. (1) 18/51 patients (35%) had disturbed autoregulation. Phenotypically, a higher proportion of patients with disturbed autoregulation had pre-CA hypertension (31±47 vs. 65±49%, p=0.02) suggesting that right shifting of autoregulation is caused by chronic adaptation of cerebral blood flow to higher blood pressures. (2) In multivariate analysis, patients with preserved autoregulation (n=33, 65%) had a significant higher 180-days survival rate (OR 4.62, 95% CI [1.06:20.06], p=0.04]. Based on an index of autoregulation (COX), the average COX-predicted optimal MAP was 85 mmHg in patients with preserved and 100 mmHg in patients with disturbed autoregulation. (3) An individual optimal MAP could be determined in 33/51 patients. (4) The time under the individual optimal MAP was negatively associated with survival (OR 0.97, 95% CI [0.96:0.99], p=0.02). The time under previously proposed fixed targets (65, 70, 75, 80 mmHg) was not associated with a differential survival rate. Cerebral autoregulation showed to be disturbed in 35% of post-CA patients of which a majority had pre-CA hypertension. Disturbed cerebral autoregulation within the first 24h after CA is associated with a worse outcome. In contrast to uniform MAP goals, the time spent under a patient tailored optimal MAP, based on an index of autoregulation, was negatively associated with survival. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

    Fahrutdinova, Antonina; Rizhov, Dmitriy; Magdeev, Konstantin

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

  17. Direct Observation of Academic Learning Time.

    ERIC Educational Resources Information Center

    Wilson, Rich

    1987-01-01

    Classroom variables associated with academic learning time (ALT)--instructional time, on-task behavior, and student success rate--are positively related to student achievement. Guidelines and forms are provided for teachers and supervisors to gather objective and usable information on these ALT components through direct classroom observation…

  18. Effect of reconstruction methods and x-ray tube current-time product on nodule detection in an anthropomorphic thorax phantom: A crossed-modality JAFROC observer study.

    PubMed

    Thompson, J D; Chakraborty, D P; Szczepura, K; Tootell, A K; Vamvakas, I; Manning, D J; Hogg, P

    2016-03-01

    To evaluate nodule detection in an anthropomorphic chest phantom in computed tomography (CT) images reconstructed with adaptive iterative dose reduction 3D (AIDR(3D)) and filtered back projection (FBP) over a range of tube current-time product (mAs). Two phantoms were used in this study: (i) an anthropomorphic chest phantom was loaded with spherical simulated nodules of 5, 8, 10, and 12 mm in diameter and +100, -630, and -800 Hounsfield units electron density; this would generate CT images for the observer study; (ii) a whole-body dosimetry verification phantom was used to ultimately estimate effective dose and risk according to the model of the BEIR VII committee. Both phantoms were scanned over a mAs range (10, 20, 30, and 40), while all other acquisition parameters remained constant. Images were reconstructed with both AIDR(3D) and FBP. For the observer study, 34 normal cases (no nodules) and 34 abnormal cases (containing 1-3 nodules, mean 1.35 ± 0.54) were chosen. Eleven observers evaluated images from all mAs and reconstruction methods under the free-response paradigm. A crossed-modality jackknife alternative free-response operating characteristic (JAFROC) analysis method was developed for data analysis, averaging data over the two factors influencing nodule detection in this study: mAs and image reconstruction (AIDR(3D) or FBP). A Bonferroni correction was applied and the threshold for declaring significance was set at 0.025 to maintain the overall probability of Type I error at α = 0.05. Contrast-to-noise (CNR) was also measured for all nodules and evaluated by a linear least squares analysis. For random-reader fixed-case crossed-modality JAFROC analysis, there was no significant difference in nodule detection between AIDR(3D) and FBP when data were averaged over mAs [F(1, 10) = 0.08, p = 0.789]. However, when data were averaged over reconstruction methods, a significant difference was seen between multiple pairs of mAs settings [F(3, 30) = 15.96, p < 0

  19. Effect of reconstruction methods and x-ray tube current–time product on nodule detection in an anthropomorphic thorax phantom: A crossed-modality JAFROC observer study

    SciTech Connect

    Thompson, J. D.; Chakraborty, D. P.; Szczepura, K.; Tootell, A. K.; Vamvakas, I.; Manning, D. J.; Hogg, P.

    2016-03-15

    Purpose: To evaluate nodule detection in an anthropomorphic chest phantom in computed tomography (CT) images reconstructed with adaptive iterative dose reduction 3D (AIDR{sup 3D}) and filtered back projection (FBP) over a range of tube current–time product (mAs). Methods: Two phantoms were used in this study: (i) an anthropomorphic chest phantom was loaded with spherical simulated nodules of 5, 8, 10, and 12 mm in diameter and +100, −630, and −800 Hounsfield units electron density; this would generate CT images for the observer study; (ii) a whole-body dosimetry verification phantom was used to ultimately estimate effective dose and risk according to the model of the BEIR VII committee. Both phantoms were scanned over a mAs range (10, 20, 30, and 40), while all other acquisition parameters remained constant. Images were reconstructed with both AIDR{sup 3D} and FBP. For the observer study, 34 normal cases (no nodules) and 34 abnormal cases (containing 1–3 nodules, mean 1.35 ± 0.54) were chosen. Eleven observers evaluated images from all mAs and reconstruction methods under the free-response paradigm. A crossed-modality jackknife alternative free-response operating characteristic (JAFROC) analysis method was developed for data analysis, averaging data over the two factors influencing nodule detection in this study: mAs and image reconstruction (AIDR{sup 3D} or FBP). A Bonferroni correction was applied and the threshold for declaring significance was set at 0.025 to maintain the overall probability of Type I error at α = 0.05. Contrast-to-noise (CNR) was also measured for all nodules and evaluated by a linear least squares analysis. Results: For random-reader fixed-case crossed-modality JAFROC analysis, there was no significant difference in nodule detection between AIDR{sup 3D} and FBP when data were averaged over mAs [F(1, 10) = 0.08, p = 0.789]. However, when data were averaged over reconstruction methods, a significant difference was seen between

  20. Effect of reconstruction methods and x-ray tube current–time product on nodule detection in an anthropomorphic thorax phantom: A crossed-modality JAFROC observer study

    PubMed Central

    Thompson, J. D.; Chakraborty, D. P.; Szczepura, K.; Tootell, A. K.; Vamvakas, I.; Manning, D. J.; Hogg, P.

    2016-01-01

    Purpose: To evaluate nodule detection in an anthropomorphic chest phantom in computed tomography (CT) images reconstructed with adaptive iterative dose reduction 3D (AIDR3D) and filtered back projection (FBP) over a range of tube current–time product (mAs). Methods: Two phantoms were used in this study: (i) an anthropomorphic chest phantom was loaded with spherical simulated nodules of 5, 8, 10, and 12 mm in diameter and +100, −630, and −800 Hounsfield units electron density; this would generate CT images for the observer study; (ii) a whole-body dosimetry verification phantom was used to ultimately estimate effective dose and risk according to the model of the BEIR VII committee. Both phantoms were scanned over a mAs range (10, 20, 30, and 40), while all other acquisition parameters remained constant. Images were reconstructed with both AIDR3D and FBP. For the observer study, 34 normal cases (no nodules) and 34 abnormal cases (containing 1–3 nodules, mean 1.35 ± 0.54) were chosen. Eleven observers evaluated images from all mAs and reconstruction methods under the free-response paradigm. A crossed-modality jackknife alternative free-response operating characteristic (JAFROC) analysis method was developed for data analysis, averaging data over the two factors influencing nodule detection in this study: mAs and image reconstruction (AIDR3D or FBP). A Bonferroni correction was applied and the threshold for declaring significance was set at 0.025 to maintain the overall probability of Type I error at α = 0.05. Contrast-to-noise (CNR) was also measured for all nodules and evaluated by a linear least squares analysis. Results: For random-reader fixed-case crossed-modality JAFROC analysis, there was no significant difference in nodule detection between AIDR3D and FBP when data were averaged over mAs [F(1, 10) = 0.08, p = 0.789]. However, when data were averaged over reconstruction methods, a significant difference was seen between multiple pairs of mAs settings

  1. Distracted Biking: An Observational Study

    PubMed Central

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

    2016-01-01

    Commuting via bicycle is a very popular mode of transportation in the Northeastern United States (US). Boston, MA has seen a rapid increase in bicycle ridership over the past decade which has raised concerns and awareness about bicycle safety. An emerging topic in this field is distracted bicycle riding. This study was conducted to provide descriptive data on the prevalence and type of distracted bicycling in Boston at different times of day. This was a cross-sectional study in which observers tallied bicyclists at four high traffic intersections in Boston during various peak commuting hours for two types of distractions: auditory (ear buds/phones in or on ears), and visual/tactile (electronic device or other object in hand). Nineteen hundred seventy-four bicyclists were observed and 615 (31.2%, 95% CI: 29%-33%) were distracted. Of those observed, auditory distractions were the most common (N= 349 [17.7%, 95% CI: 16%-19%], p=0.0003) followed by visual/tactile distractions (N= 266 [13.5%, 95% CI: 12%-15%]). The highest proportion (40.7%, 95% CI: 35%-46%) of distracted bicyclists was observed during the midday commute (between 13:30-15:00). Distracted bicycling is a prevalent safety concern in the city of Boston, as almost one-third of all bicyclists exhibited distracted behavior. Education and public awareness campaigns should be designed to decrease distracted bicycling behaviors and promote bicycle safety in Boston. An awareness of the prevalence of distracted biking can be utilized to promote bicycle safety campaigns dedicated to decreasing distracted bicycling and to provide a baseline against which improvements can be measured. PMID:26953533

  2. Explanation and observability of diffraction in time

    SciTech Connect

    Torrontegui, E.; Muga, J. G.; Munoz, J.; Ban, Yue

    2011-04-15

    Diffraction in time (DIT) is a fundamental phenomenon in quantum dynamics due to time-dependent obstacles and slits. It is formally analogous to diffraction of light, and is expected to play an increasing role in the design of coherent matter wave sources, as in the atom laser, to analyze time-of-flight information and emission from ultrafast pulsed excitations, and in applications of coherent matter waves in integrated atom-optical circuits. We demonstrate that DIT emerges robustly in quantum waves emitted by an exponentially decaying source and provide a simple explanation of the phenomenon, as an interference of two characteristic velocities. This allows for its controllability and optimization.

  3. An observational study on changes in biometry and generation time of Odontophora villoti (Nematoda, Axonolaimidae) related to petroleum pollution in Bizerte bay, Tunisia.

    PubMed

    Boufahja, Fehmi; Hedfi, Amor; Essid, Naceur; Aïssa, Patricia; Mahmoudi, Ezzeddine; Beyrem, Hamouda

    2012-03-01

    We conducted a yearly polluted-reference sampling to assess the effects of petroleum pollution on life cycle characteristics of the meiobenthic nematode Odontophora villoti. Samples were taken every 15 days between 26 November 2004 and 25 November 2005 from two beaches of Bizerte bay (Tunisia), Rimel and Tunisian Refining Industries Company (TRIC). The latter site is located in front of the "Tunisian Refining Industries Company" runoff. When compared to the reference site, the mean body dimensions of O. villoti from the impacted site were significantly lower. The small size of affected nematodes was represented both by the length and width as a function of the life stage. It was also established that changes in lengths of body parts during molts were different between the two study sites. The low availability of oxygen from April to August seems to prevent the formation of embryos of O. villoti. Thus, two annual reproductive cycles with different durations were observed in Rimel and TRIC. Under stress, juvenile phase and egg production were generally shorter. Globally, the impact of petroleum pollution on O. villoti was expressed by a short egg-to-egg development time. Our study assessed the usefulness of life cycle characteristics (biometry and life stage durations) of O. villoti in biomonitoring, and the results are generally consistent suggesting that this species may be considered as an efficient bioindicator.

  4. The Observational Learning of a Timing Skill.

    ERIC Educational Resources Information Center

    Bird, Anne Marie; And Others

    Current social learning theory proposes that motor skill information which is acquired by means of observational strategies is stored cognitively in the form of a conceptual representation. The latter is then said to be used as a basis for response production and as a standard for response corrections which occur as a function of performance…

  5. Observational Timing Study on the SAT Reasoning Test™ for Test-Takers with Learning Disabilities and/or AD/HD. Research Report No. 2006-4. ETS RR-06-23

    ERIC Educational Resources Information Center

    Cahalan-Laitusis, Cara; King, Teresa C.; Cline, Frederick; Bridgeman, Brent

    2006-01-01

    The purpose of this study is to provide information on actual time used by students with disabilities on the new SAT®. This study observed students with learning disabilities (LD) and/or attention deficit/hyperactivity disorder (AD/HD) as they took SAT items under strict time limits and recorded the amount of time taken for each item. The study is…

  6. Dose–response association of screen time-based sedentary behaviour in children and adolescents and depression: a meta-analysis of observational studies

    PubMed Central

    Liu, Mingli; Wu, Lang; Yao, Shuqiao

    2016-01-01

    Background Depression represents a growing public health burden. Understanding how screen time (ST) in juveniles may be associated with risk of depression is critical for the development of prevention and intervention strategies. Findings from studies addressing this question thus far have been inconsistent. Therefore, we conducted a comprehensive systematic review and meta-analysis of data related to this question. Methods The meta-analysis was conducted in accordance with the PRISMA guideline. We searched the electronic databases of PubMed, Web of Science and EBSCO systematically (up to 6 May 2015). OR was adopted as the pooled measurement of association between ST and depression risk. Dose–response was estimated by a generalised least squares trend estimation. Results Twelve cross-sectional studies and four longitudinal studies (including 1 cohort study) involving a total of 127 714 participants were included. Overall, higher ST in preadolescent children and adolescents was significantly associated with a higher risk of depression (OR=1.12; 95% CI 1.03 to 1.22). Screen type, age, population and reference category acted as significant moderators. Compared with the reference group who had no ST, there was a non-linear dose–response association of ST with a decreasing risk of depression at ST<2 h/day, with the lowest risk being observed for 1 h/day (OR=0.88; 95% CI 0.84 to 0.93). Conclusions Our meta-analysis suggests that ST in children and adolescents is associated with depression risk in a non-linear dose–response manner. PMID:26552416

  7. Preventing exercise-induced hypoglycemia in type 1 diabetes using real-time continuous glucose monitoring and a new carbohydrate intake algorithm: an observational field study.

    PubMed

    Riddell, Michael C; Milliken, Jill

    2011-08-01

    Real-time (RT) continuous glucose monitoring (CGM) offers the possibility to better manage glucose levels during exercise in active individuals with type 1 diabetes mellitus (T1DM). However, studies have yet to determine the appropriate actions to take when glucose levels are trending toward hypoglycemia. The purpose of this observational field study was to test the effectiveness of RT-GCM and a new carbohydrate intake algorithm designed for maintaining euglycemia during sports. During a 2-week sports camp, 25 adolescents (8-17 years old) with T1DM were fitted with a RT-CGM device and instructed to ingest fast-acting carbohydrates (8-20 g, depending on the concentration of glucose at the time of RT-CGM alert and rates of change in glycemia) when glucose levels were trending toward hypoglycemia. Rates of change in glucose were measured before and after algorithm use, and the incidence of hypoglycemia was documented. With RT-CGM and algorithm use, euglycemia was largely maintained with modest amounts of carbohydrate intake, even when glucose levels were initially dropping at an elevated rate (>0.55 mmol/L per 5 min). Mild biochemical hypoglycemia (3.0-3.9 mmol/L) occurred just twice out of 22 uses of the algorithm (9%) when trend arrows alerted the subjects that glucose levels were dropping. When glucose levels were already below target (<5.0 mmol/L), mild hypoglycemia occurred five times out of 13 events (38%), despite 16 g of carbohydrate being ingested. Average glucose levels during sports in the 60 min following algorithm use were 5.8 ± 1.2 mmol/L, 5.3 ± 1.0 mmol/L, and 6.2 ± 0.8 mmol/L in the 20-, 16-, and 8-g carbohydrate intake protocols when glucose levels were initially on target but dropping toward hypoglycemia. When coupled with RT-CGM, a new carbohydrate intake algorithm prevents hypoglycemia and maintains euglycemia during exercise, particularly if patients ingest carbohydrate when trend arrows alert them of a drop in glycemia.

  8. People with stroke spend more time in active task practice, but similar time in walking practice, when physiotherapy rehabilitation is provided in circuit classes compared to individual therapy sessions: an observational study.

    PubMed

    English, Coralie; Hillier, Susan; Kaur, Gurpreet; Hundertmark, Laura

    2014-03-01

    Do people with stroke spend more time in active task practice during circuit class therapy sessions versus individual physiotherapy sessions? Do people with stroke practise different tasks during circuit class therapy sessions versus individual physiotherapy sessions? Prospective, observational study. Twenty-nine people with stroke in inpatient rehabilitation settings. Individual therapy sessions and circuit class therapy sessions provided within a larger randomised controlled trial. Seventy-nine therapy sessions were video-recorded and the footage was analysed for time spent engaged in various categories of activity. In a subsample of 28 videos, the number of steps taken by people with stroke per therapy session was counted. Circuit class therapy sessions were of a longer duration (mean difference 38.0minutes, 95% CI 29.9 to 46.1), and participants spent more time engaged in active task practice (mean difference 23.8minutes, 95% CI 16.1 to 31.4) compared with individual sessions. A greater percentage of time in circuit class therapy sessions was spent practising tasks in sitting (mean difference 5.3%, 95% CI 2.4 to 8.2) and in sit-to-stand practice (mean difference 2.7%, 95% CI 1.4 to 4.1), and a lower percentage of time in walking practice (mean difference 19.1%, 95% CI 10.0 to 28.1) compared with individual sessions. PARTICIPANTS took an average of 371 steps (SD 418) during therapy sessions and this did not differ significantly between group and individual sessions. People with stroke spent more time in active task practice, but a similar amount of time in walking practice when physiotherapy was offered in circuit class therapy sessions versus individual therapy sessions. There is a need for effective strategies to increase the amount of walking practice during physiotherapy sessions for people after stroke. Copyright © 2014 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

  9. Emergency room visits for respiratory conditions in children increased after Guagua Pichincha volcanic eruptions in April 2000 in Quito, Ecuador Observational Study: Time Series Analysis

    PubMed Central

    Naumova, Elena N; Yepes, Hugo; Griffiths, Jeffrey K; Sempértegui, Fernando; Khurana, Gauri; Jagai, Jyotsna S; Játiva, Edgar; Estrella, Bertha

    2007-01-01

    Background This study documented elevated rates of emergency room (ER) visits for acute upper and lower respiratory infections and asthma-related conditions in the children of Quito, Ecuador associated with the eruption of Guagua Pichincha in April of 2000. Methods We abstracted 5169 (43% females) ER records with primary respiratory conditions treated from January 1 – December 27, 2000 and examined the change in pediatric ER visits for respiratory conditions before, during, and after exposure events of April, 2000. We applied a Poisson regression model adapted to time series of cases for three non-overlapping disease categories: acute upper respiratory infection (AURI), acute lower respiratory infection (ALRI), and asthma-related conditions in boys and girls for three age groups: 0–4, 5–9, and 10–15 years. Results At the main pediatric medical facility, the Baca Ortiz Pediatric Hospital, the rate of emergency room (ER) visits due to respiratory conditions substantially increased in the three weeks after eruption (RR = 2.22, 95%CI = [1.95, 2.52] and RR = 1.72 95%CI = [1.49, 1.97] for lower and upper respiratory tract infections respectively. The largest impact of eruptions on respiratory distress was observed in children younger than 5 years (RR = 2.21, 95%CI = [1.79, 2.73] and RR = 2.16 95%CI = [1.67, 2.76] in boys and girls respectively). The rate of asthma and asthma-related diagnosis doubled during the period of volcano fumarolic activity (RR = 1.97, 95%CI = [1.19, 3.24]). Overall, 28 days of volcanic activity and ash releases resulted in 345 (95%CI = [241, 460]) additional ER visits due to respiratory conditions. Conclusion The study has demonstrated strong relationship between ash exposure and respiratory effects in children. PMID:17650330

  10. Prevalence of preoperative anaemia in patients having first-time cardiac surgery and its impact on clinical outcome. A retrospective observational study.

    PubMed

    Kim, C J; Connell, H; McGeorge, A D; Hu, R

    2015-05-01

    The prevalence of anaemia is increasing globally. It has a close association with perioperative blood transfusion which, in turn, results in an increased risk of postoperative complications. Undesirable effects are not only limited to short-term, but also have long-term implications. Despite this, many patients undergo cardiac surgery with undiagnosed and untreated anaemia. We designed a retrospective, observational study to estimate the prevalence of anaemia in patients having cardiac surgery in Auckland District Health Board, blood transfusion rates and associated clinical outcome. Two hundred of seven hundred and twelve (28.1%) patients were anaemic. Red blood cell (RBC) transfusion rates were significantly higher in the anaemic group compared to the non-anaemic group (160 (80%) vs. 192 (38%), p-value <0.0001, RR (CI 95%) 2.133 (1.870-2.433)). Transfusion rates for fresh frozen plasma (FFP), cryoprecipitate and platelets were also higher in the anaemic group. Anaemia was significantly associated with the development of new infection (14 (7%) vs. 15 (2.9%), p-value 0.0193, RR (CI 95%) 2.389 (1.175-4.859)), prolonged ventilation time (47.01 hours vs. 23.59 hours, p-value 0.0076) and prolonged intensive care unit (ICU) stay (80.23 hours vs. 50.27, p-value 0.0011). Preoperative anaemia is highly prevalent and showed a clear link with significantly higher transfusion rates and postoperative morbidity. It is vital that a preoperative management plan for the correction of anaemia should be sought to improve patient safety and outcome.

  11. Summary of Sonic Boom Rise Times Observed During FAA Community Response Studies over a 6-Month Period in the Oklahoma City Area

    NASA Technical Reports Server (NTRS)

    Maglieri, Domenic J.; Sothcott, Victor E.

    1990-01-01

    The sonic boom signature data acquired from about 1225 supersonic flights, over a 6-month period in 1964 in the Oklahoma City area, was enhanced with the addition of data relating to rise times and total signature duration. These later parameters, not available at the time of publication of the original report on the Oklahoma City sonic boom exposures, are listed in tabular form along with overpressure, positive impulse, positive duration, and waveform category. Airplane operating information along with the surface weather observations are also included. Sonic boom rise times include readings to the 1/2, 3/4, and maximum overpressure values. Rise time relative probabilities for various lateral locations from the ground track of 0, 5, and 10 miles are presented along with the variation of rise times with flight altitude. The tabulated signature data, along with corresponding airplane operating conditions and surface and upper level atmospheric information, are also available on electronic files to provide it in the format for more efficient and effective utilization.

  12. The role of sleep timing in children's observational learning.

    PubMed

    van Schalkwijk, Frank J; Benjamins, Jeroen S; Migliorati, Filippo; de Nooijer, Jacqueline A; van Someren, Eus J W; van Gog, Tamara; van der Werf, Ysbrand D

    2015-11-01

    Acquisition of information can be facilitated through different learning strategies, classically associated with either declarative or procedural memory modalities. The consolidation of the acquired information has been positively associated with sleep. In addition, subsequent performance was better when acquisition was quickly followed by sleep, rather than daytime wakefulness. Prior studies with adults have indicated the viability of the alternative learning strategy of observational learning for motor skill acquisition, as well as the importance of sleep and sleep timing. However, relatively little research has been dedicated to studying the importance of sleep for the consolidation of procedural memory in children. Therefore, this study investigated whether children could encode procedural information through observational learning, and whether sleep timing could affect subsequent consolidation and performance. School-aged children aged 9-12years (N=86, 43% male, Mage=10.64years, SD=.85) were trained on a procedural fingertapping task through observation, either in the morning or evening; creating immediate wake and immediate sleep groups, respectively. Performance was evaluated the subsequent evening or morning on either a congruent or incongruent task version. Observation and task execution was conducted using an online interface, allowing for remote participation. Performance of the immediate wake group was lower for a congruent version, expressed by a higher error rate, opposed to an incongruent version; an effect not observed in the immediate sleep group. This finding showed that observational learning did not improve performance in children. Yet, immediate sleep prevented performance reduction on the previously observed task. These results support a benefit of sleep in observational learning in children, but in a way different from that seen in adults, where sleep enhanced performance after learning by observation.

  13. Do celebrity endorsements matter? Observational study of BRCA gene testing and mastectomy rates after Angelina Jolie’s New York Times editorial

    PubMed Central

    Desai, Sunita

    2016-01-01

    Objective To examine the effect on BRCA testing and mastectomy rates of a widely viewed 2013 New York Times editorial by public figure Angelina Jolie that endorsed BRCA testing and announced Jolie’s decision to undergo preventive mastectomy. Design Observational study with difference-in-difference analysis. Setting Commercially insured US population. Participants Women aged 18-64 years with claims in the Truven MarketScan commercial claims database (n=9 532 836). Main outcome measures Changes in BRCA testing rates in the 15 business days before versus after 14 May 2013 (editorial date) compared with the change in the same period in 2012; mastectomy rates in the months before and after publication, both overall and within 60 days of BRCA testing among women who were tested; national estimates of incremental tests and expenditures associated with Jolie’s article in the 15 days after publication. Results Daily BRCA test rates increased immediately after the 2013 editorial, from 0.71 tests/100 000 women in the 15 business days before to 1.13 tests/100 000 women in the 15 business days after publication. In comparison, daily test rates were similar in the same period in 2012 (0.58/100 000 women in the 15 business days before 14 May versus 0.55/100 000 women in the 15 business days after), implying a difference-in-difference absolute daily increase of 0.45 tests/100 000 women or a 64% relative increase (P<0.001). The editorial was associated with an estimated increase of 4500 BRCA tests and $13.5m (£10.8m; €12.8) expenditure nationally among commercially insured adult women in those 15 days. Increased BRCA testing rates were sustained throughout 2013. Overall mastectomy rates remained unchanged in the months after publication, but 60 day mastectomy rates among women who had a BRCA test fell from 10% in the months before publication to 7% in the months after publication, suggesting that women who underwent tests as a result of to the editorial

  14. Observed and projected trends in paediatric health resources and services in China between 2003 and 2030: a time-series study.

    PubMed

    Zhang, Xin-Yu; Gao, Ying; Li, Chang-Ping; Zheng, Rong-Xiu; Chen, Jie-Li; Zhao, Lin; Wang, You-Fa; Wang, Yao-Gang

    2017-06-24

    The two-child policy took effect in China on 1 January 2016, thus officially ending the one-child policy. The resultant growth in the population will create a considerable demand for public services such as paediatric healthcare, even while there are limited paediatric resources. We estimated the relationship between paediatric health resources and services and child mortality to determine the degree of the deficiency of such resources in China. Projecting the quantity of paediatric health resource allocation and service supply through 2030 will help provide data reference for future policy decision making. Time-series study. The People's Republic of China. Paediatric patients whose data were recorded between 2003 and 2012 from the National Health and Family Planning Commission of the People's Republic of China. Child mortality and paediatric health resources and services data were entered into a cubic polynomial regression model to project paediatric health resources and services to 2030. Child mortality decreased throughout the past decade. Furthermore, the number of paediatric beds, paediatricians and nurses increased between 2003 and 2012, although the proportions increased rather slowly. Both the number and proportion of paediatric outpatients and inpatients increased rapidly. The observed and model-predicted values matched well (adjusted R(2)=93.8% for paediatric beds; adjusted R(2)=96.6% for paediatric outpatient visits). Overall, the projection indicated that paediatric beds, paediatricians and nurses will reach 460 148, 233 884 and 184 059 by 2030, respectively. Regarding paediatric services, the number of paediatric outpatient visits and inpatients is expected to reach upwards of 449.95 million and 21.83 million by 2030, respectively. Despite implementation of the two-child policy, resource allocation in paediatrics has many deficiencies. Proper measures should be taken to actively respond to the demand for paediatric health services. © Article

  15. The effect of handwashing at recommended times with water alone and with soap on child diarrhea in rural Bangladesh: an observational study.

    PubMed

    Luby, Stephen P; Halder, Amal K; Huda, Tarique; Unicomb, Leanne; Johnston, Richard B

    2011-06-01

    Standard public health interventions to improve hand hygiene in communities with high levels of child mortality encourage community residents to wash their hands with soap at five separate key times, a recommendation that would require mothers living in impoverished households to typically wash hands with soap more than ten times per day. We analyzed data from households that received no intervention in a large prospective project evaluation to assess the relationship between observed handwashing behavior and subsequent diarrhea. Fieldworkers conducted a 5-hour structured observation and a cross-sectional survey in 347 households from 50 villages across rural Bangladesh in 2007. For the subsequent 2 years, a trained community resident visited each of the enrolled households every month and collected information on the occurrence of diarrhea in the preceding 48 hours among household residents under the age of 5 years. Compared with children living in households where persons prepared food without washing their hands, children living in households where the food preparer washed at least one hand with water only (odds ratio [OR]=0.78; 95% confidence interval [CI]=0.57-1.05), washed both hands with water only (OR=0.67; 95% CI=0.51-0.89), or washed at least one hand with soap (OR=0.30; 95% CI=0.19-0.47) had less diarrhea. In households where residents washed at least one hand with soap after defecation, children had less diarrhea (OR=0.45; 95% CI=0.26-0.77). There was no significant association between handwashing with or without soap before feeding a child, before eating, or after cleaning a child's anus who defecated and subsequent child diarrhea. These observations suggest that handwashing before preparing food is a particularly important opportunity to prevent childhood diarrhea, and that handwashing with water alone can significantly reduce childhood diarrhea.

  16. Cost-effectiveness of blood culture and a multiplex real-time PCR in hematological patients with suspected sepsis: an observational propensity score-matched study.

    PubMed

    Mancini, Nicasio; Sambri, Vittorio; Corti, Consuelo; Ghidoli, Nadia; Tolomelli, Giulia; Paolucci, Michela; Clerici, Daniela; Carletti, Silvia; Greco, Raffaella; Tassara, Michela; Pizzorno, Beatrice; Zaniolo, Orietta; Povero, Massimiliano; Pradelli, Lorenzo; Burioni, Roberto; Stanzani, Marta; Landini, Maria Paola; Ciceri, Fabio; Clementi, Massimo

    2014-06-01

    We evaluated the costs and clinical outcomes of episodes of suspected sepsis in hematological patients. A propensity score-matched study was planned, comparing a retrospective cohort managed with standard assays and a prospective cohort managed with the addition of a molecular assay. Diagnostic procedures and therapy were considered as costs variables. The primary clinical endpoint was sepsis-related mortality, whereas the length of each suspected sepsis episode was investigated as a secondary endpoint. A total of 137 and 138 episodes in the prospective and the retrospective cohorts were studied, respectively; 101 pairs of highly matched episodes were analyzed, evidencing a trend of higher mortality in the retrospective cohort. No difference in length of suspected sepsis episode was observed. Significant savings were observed in the prospective cohort, especially due to reduced costs in antifungal therapy. The apparently more expensive molecular assay favored a more rational use of economic resources without influencing, and probably improving, the clinical outcome.

  17. Identifying potential predictors of high-quality oral anticoagulation assessed by time in therapeutic international normalized ratio range: a prospective, long-term, single-center, observational study.

    PubMed

    Costa, Gustavo Lamego de Barros; Lamego, Rosana Morais; Colosimo, Enrico A; Valacio, Reginaldo Aparecido; Moreira, Maria da Consolação Vieira

    2012-07-01

    The efficacy and risks of oral anticoagulation are largely associated with maintaining the quality of anticoagulation control. Nevertheless, few studies have addressed which factors, if any, are associated with this control. This study aimed to identify predictors of high-quality oral anticoagulation. A prospective observational study enrolled all adult patients on intended long-term oral anticoagulation attending a public anticoagulation clinic. Patients with high-quality anticoagulation, defined as percentage of time in therapeutic international normalized ratio (INR) range (TTR) ≥66%, were compared with those with poor anticoagulation control (TTR <66%). Measures included cognitive, psychological, and relevant behavioral factors, in addition to traditionally implicated ones, such as age, comorbidity, and concurrent medications. Participation was requested from all 233 patients followed up at the anticoagulation clinic. Eighty-six did not meet the inclusion criteria (49 due to intended anticoagulation duration <90 days, 37 due to the need for a caregiver responsible for medications). A total of 147 patients were enrolled, of whom 13 (8.8%) were lost to follow-up. Therefore, data were analyzed from 134 patients (mean [SD] age, 55 [14.2] years [range, 19-87 years]), who were followed up for a mean (SD) duration of 272 (87) days. The total mean TTR was 64.7%, which is comparable to values achieved in clinical trials. The good-control group had 61 patients (45.5%) (mean TTR, 77.7% [8.5%]) and the poor-control group had 73 patients (54.5%) (mean TTR, 50.4 [11.7%]). On multivariate logistic regression analysis, high-quality anticoagulation was independently associated with regular vitamin K intake, expressed by its variability in daily dosage (odds ratio [OR] = 0.79; 95% CI, 0.64-0.98); male sex (OR = 2.41; 95% CI, 1.06-5.49); duration of anticoagulation treatment >2 months (OR = 3.23; 95% CI, 1.25-8.36); presence of family support (OR = 3.32; 95% CI, 1

  18. Observation of time-dependent adverse events and the influence of drop-out thereon in long-term safety studies--simulation study under the current practice of post-marketing safety evaluation in Japan.

    PubMed

    Narukawa, Mamoru; Yafune, Akifumi; Takeuchi, Masahiro

    2004-05-01

    Safety assessment of a new drug should be continuously carried out in the premarketing phase as well as in the postmarketing phase. Considering the actual conditions and problems of postmarketing safety studies in Japan, i.e., the lack of attention to the extent of patients' exposure to the drug (duration and the number of patients), we simulated the number of adverse events to be observed after specified intervals of exposure. This was done by applying different sets of hazard functions for a Weibull distribution under the circumstances that a certain number of patients has dropped out, focusing on rare and delayed adverse events associated with chronically used drugs. By using the result of these simulations, we point out potential problems of underestimating adverse event rates in situations where the hazard rate of the event escalates over time. Patients drop-out from the study also deteriorates the ability to observe such time-dependent adverse events. The simulation can also serve as a useful tool to examine the necessary sample size and the duration of exposure in order to observe and characterize potentially expected adverse events. It is important to take the two key factors into consideration: the change of hazard function over time and the effect of drop-out in designing, analyzing, and evaluating safety studies for new drugs.

  19. Transiting Primary Eclipse Photometric Follow-up Observations and Transit Timing Variations Studies of WASP-43 b and TrES-3 b

    NASA Astrophysics Data System (ADS)

    Sun, Z.; Ji, J. H.; Dong, Y.

    2016-11-01

    Two photometric follow-up observations for transiting primary eclipse of WASP-43 b and four for TrES-3 b are performed using the Xuyi Near-Earth Object Survey Telescope. After differential photometry and light curve analysis, physical parameters of the two systems are obtained and are in good match with the literatures. Combining with transit data from many literatures, the residuals (O-C) of observations of both systems transits are fitted with the linear and quadratic terms. With the linear fitting, the periods and transit timing variations (TTVs) of the planets are obtained, and no obvious periodic TTV signal is found in either system after analysis. The maximum mass of perturbing planet located at 1:2 mean motion resonance (MMR) of WASP-43 b and TrES-3 b are estimated to be 1.826 and 1.504 Earth mass, respectively. By quadratic fitting, it is confirmed that WASP-43 b may have long-term TTV which means an orbital decay. The decay rate is shown to be dot{P} =(-0.005248 ± 0.001714) s\\cdotyr^{-1}, and is compared with the previous results. Based on this, the lower limit of the stellar tidal quality parameter of WASP-43 is calculated to be Q'_{*} ≥ 1.5×10^5, and the remaining lifetime of the planets of both systems is presented for different Q'_{*} values accordingly.

  20. Extreme-Ultraviolet and X-Ray Spectroscopy of a Solar Flare Loop Observed at High Time Resolution: A Case Study in Chromospheric Evaporation

    NASA Astrophysics Data System (ADS)

    Brosius, Jeffrey W.; Phillips, Kenneth J. H.

    2004-09-01

    We present extreme-ultraviolet (EUV) and X-ray light curves and Doppler velocity measurements for a GOES class M2 solar flare observed in NOAA Active Region 9433 on 2001 April 24 at high time resolution with the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO) satellite (9.83 s) and the Bragg Crystal Spectrometer (BCS) and Hard X-Ray Telescope (HXT) on board the Yohkoh satellite (9.00 s). Coordinated imagery with SOHO's Extreme-ultraviolet Imaging Telescope and the Transition Region and Coronal Explorer satellite reveal that the CDS slit was centered on the flare commencement site; coordinated magnetograms from SOHO's Michelson Doppler Imager are consistent with this site being the footpoint of a flare loop anchored in positive magnetic field near the outer edge of a sunspot's penumbra. CDS observations include the preflare quiescent phase, two precursors, the flare impulsive and peak phases, and its slow decline. We find that (1) the average wavelengths of O III, O IV, O V, Ne VI, and He II lines measured during the preflare quiescent phase are equal (within the measurement uncertainties) to those measured during the late decline phase, indicating that they can be used as reference standards against which to measure Doppler velocities during the flare; (2) the EUV lines of O III, O IV, O V, and He II exhibit upflow velocities of ~40 km s-1 during both precursor events, suggestive of small-scale chromospheric evaporation; (3) the Fe XIX EUV intensity rises and stays above its preflare noise level during the second (later) precursor; (4) the maximum upflow velocities measured in Fe XIX with CDS (64 km s-1) and in Ca XIX (65 km s-1) and S XV (78 km s-1) with BCS occur during the flare impulsive phase and are simultaneous within the instrumental time resolutions; (5) the Fe XIX EUV intensity begins its impulsive rise nearly 90 s later than the rise in intensities of the cooler lines; (6) hard X-ray emission arises nearly 60

  1. The Effect of Handwashing at Recommended Times with Water Alone and With Soap on Child Diarrhea in Rural Bangladesh: An Observational Study

    PubMed Central

    Luby, Stephen P.; Halder, Amal K.; Huda, Tarique; Unicomb, Leanne; Johnston, Richard B.

    2011-01-01

    Background Standard public health interventions to improve hand hygiene in communities with high levels of child mortality encourage community residents to wash their hands with soap at five separate key times, a recommendation that would require mothers living in impoverished households to typically wash hands with soap more than ten times per day. We analyzed data from households that received no intervention in a large prospective project evaluation to assess the relationship between observed handwashing behavior and subsequent diarrhea. Methods and Findings Fieldworkers conducted a 5-hour structured observation and a cross-sectional survey in 347 households from 50 villages across rural Bangladesh in 2007. For the subsequent 2 years, a trained community resident visited each of the enrolled households every month and collected information on the occurrence of diarrhea in the preceding 48 hours among household residents under the age of 5 years. Compared with children living in households where persons prepared food without washing their hands, children living in households where the food preparer washed at least one hand with water only (odds ratio [OR] = 0.78; 95% confidence interval [CI] = 0.57–1.05), washed both hands with water only (OR = 0.67; 95% CI = 0.51–0.89), or washed at least one hand with soap (OR = 0.30; 95% CI = 0.19–0.47) had less diarrhea. In households where residents washed at least one hand with soap after defecation, children had less diarrhea (OR = 0.45; 95% CI = 0.26–0.77). There was no significant association between handwashing with or without soap before feeding a child, before eating, or after cleaning a child's anus who defecated and subsequent child diarrhea. Conclusions These observations suggest that handwashing before preparing food is a particularly important opportunity to prevent childhood diarrhea, and that handwashing with water alone can significantly reduce childhood diarrhea. Please

  2. QUADRENNIAL MCNP TIMING STUDY

    SciTech Connect

    E. C. SELCOW; B. D. LANSRUD

    2000-09-01

    The Los Alamos National Laboratory Monte Carlo N-Particle radiation transport code, MCNP, is widely used around the world for many radiation protection and shielding applications. As a well-known standard it is also an excellent vehicle for assessing the relative performance of scientific computing platforms. Every three-to-four years a new version of MCNP is released internationally by the Radiation Safety Information Computational Center (RSICC) in Oak Ridge, Tennessee. For each of the past few releases, we have also done a timing study to assess the progress of scientific computing platforms and software. These quadrennial timing studies are valuable to the radiation protection and shielding community because (a) they are performed by a recognized scientific team, not a computer vendor, (b) they use an internationally recognized code for radiation protection and shielding calculations, (c) they are eminently reproducible since the code and the test problems are internationally distributed. Further, if one has a computer platform, operating system, or compiler not presented in our results, its performance is directly comparable to the ones we report because it can use the same code, data, and test problems as we used. Our results, using a single processor per platform, indicate that hardware advances during the past three years have improved performance by less than a factor of two and software improvements have had a marginal effect on performance. The most significant impacts on performance have resulted from developments in multiprocessing and multitasking. The other most significant advance in the last three years has been the accelerated improvements in personal computers. In the last timing study, the tested personal computer was approximately a factor of four slower that the fastest machine tested, a DEC Alphastation 500. In the present study, the fastest PC tested was less than a factor of two slower than the fastest platform, which is a Compaq

  3. The influence of time from injury to surgery on motor recovery and length of hospital stay in acute traumatic spinal cord injury: an observational Canadian cohort study.

    PubMed

    Dvorak, Marcel F; Noonan, Vanessa K; Fallah, Nader; Fisher, Charles G; Finkelstein, Joel; Kwon, Brian K; Rivers, Carly S; Ahn, Henry; Paquet, Jérôme; Tsai, Eve C; Townson, Andrea; Attabib, Najmedden; Bailey, Christopher S; Christie, Sean D; Drew, Brian; Fourney, Daryl R; Fox, Richard; Hurlbert, R John; Johnson, Michael G; Linassi, A G; Parent, Stefan; Fehlings, Michael G

    2015-05-01

    To determine the influence of time from injury to surgery on neurological recovery and length of stay (LOS) in an observational cohort of individuals with traumatic spinal cord injury (tSCI), we analyzed the baseline and follow-up motor scores of participants in the Rick Hansen Spinal Cord Injury Registry to specifically assess the effect of an early (less than 24 h from injury) surgical procedure on motor recovery and on LOS. One thousand four hundred and ten patients who sustained acute tSCIs with baseline American Spinal Injury Association Impairment Scale (AIS) grades A, B, C, or D and were treated surgically were analyzed to determine the effect of the timing of surgery (24, 48, or 72 h from injury) on motor recovery and LOS. Depending on the distribution of data, we used different types of generalized linear models, including multiple linear regression, gamma regression, and negative binomial regression. Persons with incomplete AIS B, C, and D injuries from C2 to L2 demonstrated motor recovery improvement of an additional 6.3 motor points (SE=2.8 p<0.03) when they underwent surgical treatment within 24 h from the time of injury, compared with those who had surgery later than 24 h post-injury. This beneficial effect of early surgery on motor recovery was not seen in the patients with AIS A complete SCI. AIS A and B patients who received early surgery experienced shorter hospital LOS. While the issues of when to perform surgery and what specific operation to perform remain controversial, this work provides evidence that for an incomplete acute tSCI in the cervical, thoracic, or thoracolumbar spine, surgery performed within 24 h from injury improves motor neurological recovery. Early surgery also reduces LOS.

  4. Sloan Digital Sky Survey observing time tracking and efficiency measurement

    SciTech Connect

    Eric H. Neilsen, Jr.; Richard G. Kron; William N. Boroski

    2002-10-16

    Accurate and consistent time tracking is essential for evaluating the efficiency of survey observing operations and identifying areas that need improvement. Off the shelf time tracking software, which requires users to enter activities by hand, proved tedious to use and insufficiently exible. In this paper, we present an alternate time tracking system developed specifically for Sloan Digital Sky Survey observing. This system uses an existing logging system, murmur, to log the beginning and ending times of tracked circumstances, including activities, weather, and problems which effect observing. Operations software automatically generates most entries for routine observing activities; in a night of routine observing, time tracking requires little or no attention from the observing staff. A graphical user interface allows observers to make entries marking time lost to weather and equipment, and to correct inaccurate entries made by the observing software. The last is necessary when the change in activity is not marked by a change in the state of the software or instruments, or when the time is used for engineering or other observing not part of routine survey data collection. A second utility generates reports of time usage from these logs. These reports include totals for the time spent for each observing task, time lost to weather and problems, efficiency statistics for comparison with the survey baseline, and a detailed listing of what activities and problems were present in any covered time period.

  5. Timing of cART initiation in Male and Female Migrants Living with HIV in Western Europe: an observational cohort study (1997-2013).

    PubMed

    2017-01-21

    We evaluate differences in timing of cART (combined Antiretroviral Treatment) initiation by geographical origin in male and female HIV-positive subjects in COHERE, a large European Collaboration of HIV Cohorts. We included individuals recruited in Western-Europe between January1997-March2013, with known geographical origin and ≥1CD4 cell count measurement while cART-naïve. Timing of cART was assessed through modified time-to-event methods where a scale of CD4 counts was used instead of time, with cART being the outcome. We estimated the median CD4 at cART initiation (estimated CD4 levels at which the probability of starting cART is 50%) using Kaplan-Meier and adjusted Hazard Ratios of cART initiation using Cox regression. Of 151674 individuals, 110 592(72.9%) were men. Median (95% CI) CD4 count falls far below 250 cells/mm in all groups, and was lowest in Sub-Saharan African [SSA:161(158-167)] and Caribbean men [CRB:161(150-174)], and in Asian women [ASIA/OC:185(165-197)]. The adjusted probability of cART initiation among men was lower in migrants compared to natives, but differences depended on initial CD4 count. For example in the group with >500 CD4 at recruitment, they were 45%(36-53%), 30%(17-40%) and 25%(19-30%) lower for CRB, Eastern European (EE) and SSA men, respectively. In women, no meaningful differences were observed between natives and most migrant groups. However, SSA women had a 31% (24-38%) higher probability of cART initiation when recruited at a CD4>500 cells/mm and 9%(4-14%) lower when recruited at CD4<100 cells/mm. Most migrant men initiate cART at lower CD4 count than natives whereas this does not hold for migrant women.

  6. Observational Study of Travelers' Diarrhea.

    PubMed

    Meuris

    1995-03-01

    Background: European air travelers returning from Algeria, Egypt, Mexico, Morocco, and Tunisia were interviewed about their experience of travelers' diseases upon arrival in Brussels. Diarrhea was mentioned by 37% of the adults and 27% of the children. These subjects were questioned about the types of measures taken, type and duration of drug treatment (if any), and about duration of diarrhea and side effects experienced. Methods: Final analysis was performed based on 2160 interviews. The largest proportion of diarrhea was reported in the age group 15-24 years (46%). Results: The majority of the 2160 subjects had opted for drug treatment (81%): 927 subjects for loperamide alone, 235 for loperamide in combination with nifuroxazide, and 178 for nifuroxazide alone. Other drugs had been used less frequently. The median time to recovery was 2.4 days with loperamide compared to 3.2 days with nifuroxazide and to 3.4 days for the no-treatment group. Conclusions: A stratification of the results by severity of the diarrhea suggests a rank of antidiarrheal potency as follows: loperamide > nifuroxazide > no-drug treatment. The side effect with the highest incidence was constipation (2.4% with loperamide). (J Travel Med 2:11-15, 1995) Travelers' diarrhea is usually defined as the passage of at least three unformed stools per day or any number of such stools when accompanied by fever, abdominal cramping, or vomiting. The definition may be broadened to include more trivial bowel disturbance.1,2 The duration of this self-limited disease generally is 3 to 5 days. Medical intervention aims at shortening the duration of disease, thus allowing the sufferer to resume his or her usual activities at an early stage. A shortened period of recovery to physical well-being has obvious favorable economic implications if the traveler is on business and may help the maintenance of a desired level of quality of life while a traveler is on holiday. An observational study of various medical

  7. Cord clamping time in spontaneously breathing preterm neonates in the first minutes after birth: impact on cerebral oxygenation - a prospective observational study.

    PubMed

    Pichler, Gerhard; Baik, Nariae; Urlesberger, Berndt; Cheung, Po-Yin; Aziz, Khalid; Avian, Alexander; Schmölzer, Georg M

    2016-01-01

    To analyse impact of delayed cord clamping (DCC60sec) on cerebral regional tissue oxygenation (crSO2) and fractional tissue oxygen extraction (cFTOE) in spontaneously breathing preterm neonates during the first 15 min after birth. Two-centre observational study, crSO2 and cFTOE was monitored in neonates with DCC60sec or early cord clamping (ECC < 30 s). Seventy-six infants (birth weight and gestational age 1736 ± 508 g and 31.8 ± 2.5 weeks) were included. DCC was associated with lower initial crSO2 and higher cFTOE and lower initial Apgar-score and heart rate. Attending practitioners should be aware that DCC might impact initial immediate transition in spontaneously breathing preterm neonates.

  8. Changes over Time and Responsiveness of the Cochin Hand Function Scale and Mouth Handicap in Systemic Sclerosis Scale in Patients with Systemic Sclerosis: A Prospective Observational Study.

    PubMed

    Nguyen, Christelle; Bérezné, Alice; Mestre-Stanislas, Caroline; Lefèvre-Colau, Marie-Martine; Rannou, François; Guillevin, Loïc; Mouthon, Luc; Poiraudeau, Serge

    2016-12-01

    To assess changes over time and responsiveness of the Cochin Hand Function Scale (CHFS) and Mouth Handicap In Systemic Sclerosis (MHISS) scale in patients with systemic sclerosis (SSc). This was a prospective longitudinal study. Participants were drawn from a convenience sample of individuals with SSc, who were attending the annual Congress of the Association des Sclérodermiques de France, the French SSc patients' association. Participants were evaluated twice by the CHFS, MHISS scale, Health Assessment Questionnaire, McMaster-Toronto Arthritis Patient Preference Disability Questionnaire, and other outcome measures. Differences in measures over time were evaluated using the Wilcoxon signed rank test. Responsiveness was assessed by the effect size and standardized response mean. Nonparametric Spearman rank correlation (r) was used to assess correlation between outcome measures. Forty-nine patients were assessed. The CHFS and MHISS scores worsened over time (mean [SD] differences 2.7 [10.7], P = 0.08, and 3.5 [9.8], P = 0.14, respectively). The CHFS effect size and standardized response mean values were -0.16 and -0.24, respectively, and MHISS values were -0.53 and -0.52, respectively. The correlation between change in the CHFS score and change in Health Assessment Questionnaire and McMaster-Toronto Arthritis Patient Preference Disability Questionnaire scores was fair to moderate, whereas changes in MHISS score were poorly or not correlated to other measures. For patients considering their state deteriorated, the MHISS scale was the most responsive instrument. The CHFS and MHISS scores may be useful in detecting changes in location-specific limitations in activity for SSc patients.

  9. Time to virological failure with atazanavir/ritonavir and lopinavir/ritonavir, with or without an H2-receptor blocker, not significantly different in HIV observational database study.

    PubMed

    Keiser, Philip H; Nassar, Naiel

    2008-08-01

    A retrospective electronic database study was conducted to determine any differences in time to virological failure and percent of virological failure among HIV-infected patients concurrently receiving H2-blockers versus patients not receiving these agents while receiving atazanavir (ATV)/ritonavir (r) or lopinavir (LPV)/r-containing antiretroviral treatment regimens. Data were culled from October 2003 (when ATV became commercially available) through February 2006. Virological failure was defined as (1) two plasma HIV-1 RNA levels >400 copies/mL after at least one HIV-1 RNA level below the level of detection or (2) failure to achieve an HIV-1 RNA <400 copies/mL within 24 weeks. Data from 267 ATV/r-treated patients who met the case definition were compared with data from 670 LPV/r-treated patients. Approximately 10% of the ATV/r group received concurrent H2-blockers when compared with 20% of the LPV/r group. Multivariate analysis showed no statistically significant differences regarding time to virological failure between or among the four subgroups, adjusting for differences in baseline characteristics (P = 0.79, log-rank test). At 750 days following treatment initiation, the proportion of patients not experiencing virological failure was 56% in the ATV/r-blocker subgroup, 48% in the ATV/r-alone subgroup, 45% in the LPV/r-alone subgroup and 42% in the LPV/r-blocker subgroup.

  10. 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.

  11. 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

  12. PM(2.5) Characterization for Time Series Studies: Organic Molecular Marker Speciation Methods and Observations from Daily Measurements in Denver.

    PubMed

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

    2009-04-01

    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.

  13. Characteristics of cigarette smoking without alcohol consumption and laryngeal cancer: overall and time-risk relation. A meta-analysis of observational studies.

    PubMed

    Zuo, Jing-Jing; Tao, Ze-Zhang; Chen, Chen; Hu, Zhang-Wei; Xu, Ye-Xing; Zheng, An-Yuan; Guo, Yi

    2017-03-01

    Tobacco smoking was one of the risk factors for upper aerodigestive tract cancer, but exclusive quantification of the impact of cigarette smoking on laryngeal cancer had not been investigated. A meta-analysis of researches that had reported quantitative estimates of cigarette smoking and risk of laryngeal cancer by March 2016 was performed. Pooled estimates of relative risks and their 95% confidence intervals were obtained and summarized. Sensitivity analysis and subgroup analysis were implemented to find out sources of research heterogeneity and the effect of potential confounders. Publication bias was investigated and corrected if found to be present through Egger's and Begg's test, and trim and fill algorithm. Thirty researches based on a total of 14,292 cases from three cohort and fifteen case-control studies were included and pooled estimate for the correlation between cigarette smoking and the risk of laryngeal cancer was 7.01 (95% confidence interval 5.56-8.85), with moderate heterogeneity across the researches (I (2) = 56.7%, p = 0.002). The RRs were 5.04 (95% CI 3.09-8.22) for cohort studies (p = 0.121), 7.59 (95% CI 5.86-9.82) for case-control studies (p = 0.005). The risk kept elevated within the first fifteen years of quitting smoking(RR 3.62, 95% CI 1.88-7.00) but dropped in the 16 years and more after smoking cessation(RR 1.88, 95% CI 1.16-3.05). Individuals who smoked with 40 or more pack-years had nine times the risk of laryngeal cancer(RR 9.14; 95% CI 6.24-13.39). Subjects who smoked 30 or more cigarettes a day had sevenfolds the risk of laryngeal cancer (RR 7.02; 95% CI 4.47-11.02) and who smoked 40 or more years had five times the risk versus never smokers (RR 5.76; 95% CI 3.69-8.99). Evidence of publication bias was not detected for the correlation between current cigarette smoking and risk of laryngeal cancer (p = 0.225 with Begg's test, p = 0.317 with Egger's test). The results demonstrated strong correlation referring to

  14. The home observation assessment method (HOAM): real-time naturalistic observation of families in their homes.

    PubMed

    Steinglass, P

    1979-09-01

    The Home Observation Assessment Method (HOAM) is a new method developed to carry out objective coding of family interaction over extended time periods in a home setting. It is a computer-compatible coding system that permits on-line data reduction of interactional variables emphasizing contextual and structural dimensions of family behavior. To date, the HOAM has been applied to the study of 31 families observed for a total of over 250 sessions. Initial analysis of data from these sessions indicates that coder reliability is high and that the HOAM successfully measures dimensions of family behavior independent of architectural aspects of the home setting. Preliminary findings also indicate that although families differ dramatically along the interactional dimensions measured by the HOAM, all families studied spent remarkably little time in decision-making behavior, suggesting that behavior in the home is predominantly "maintenance-oriented."

  15. Observational longitudinal study of symptom burden and time for recovery from community-acquired pneumonia reported by older adults surveyed nationwide using the CAP Burden of Illness Questionnaire.

    PubMed

    Wyrwich, Kathleen W; Yu, Holly; Sato, Reiko; Powers, John H

    2015-01-01

    Millions of older adults who develop community-acquired pneumonia (CAP) each year survive, but there is a large knowledge gap on the burden of CAP and the recovery process in survivors from the patient perspective. The newly developed CAP Burden of Illness Questionnaire was administered through a Web survey to a nationwide sample of US adults aged ≥50 years who were recently diagnosed with CAP. Survey respondents with unresolved symptoms or other CAP-related health problems completed a second survey 30 days later; a third survey was completed another 30 days later by respondents with unresolved symptoms or problems. Nationally representative results describing the average time to recovery of symptoms and other CAP-related problems were achieved using post-stratification weights. Five hundred participants completed the initial survey. The time to resolution for the CAP symptoms of weakness, shortness of breath, and tiredness exceeded 3 weeks on average. There was an average of 13 days of absenteeism, and 3 weeks (mean =21 days) before achieving full work/activity productivity after CAP. For participants with health conditions that worsened from pneumonia, chronic emphysema and chronic obstructive pulmonary disease took the longest to return to baseline (mean =60 and 52.4 days, respectively). The results from this study demonstrate that older adults surviving a CAP episode experience a significant multi-symptom illness with long recovery periods to achieve pre-CAP health and productivity. These findings highlight the need for further research on effective clinician-patient communication, the need for patient-centered outcomes in clinical trials for CAP therapeutics, adequate home care during the recovery process, and the pursuit of CAP prevention strategies.

  16. As time passes by: Observed motion-speed and psychological time during video playback

    PubMed Central

    Karlsson, Eric Per Anders; Antfolk, Jan

    2017-01-01

    Research shows that psychological time (i.e., the subjective experience and assessment of the passage of time) is malleable and that the central nervous system re-calibrates temporal information in accordance with situational factors so that psychological time flows slower or faster. Observed motion-speed (e.g., the visual perception of a rolling ball) is an important situational factor which influences the production of time estimates. The present study examines previous findings showing that observed slow and fast motion-speed during video playback respectively results in over- and underproductions of intervals of time. Here, we investigated through three separate experiments: a) the main effect of observed motion-speed during video playback on a time production task and b) the interactive effect of the frame rate (frames per second; fps) and motion-speed during video playback on a time production task. No main effect of video playback-speed or interactive effect between video playback-speed and frame rate was found on time production. PMID:28614353

  17. As time passes by: Observed motion-speed and psychological time during video playback.

    PubMed

    Nyman, Thomas Jonathan; Karlsson, Eric Per Anders; Antfolk, Jan

    2017-01-01

    Research shows that psychological time (i.e., the subjective experience and assessment of the passage of time) is malleable and that the central nervous system re-calibrates temporal information in accordance with situational factors so that psychological time flows slower or faster. Observed motion-speed (e.g., the visual perception of a rolling ball) is an important situational factor which influences the production of time estimates. The present study examines previous findings showing that observed slow and fast motion-speed during video playback respectively results in over- and underproductions of intervals of time. Here, we investigated through three separate experiments: a) the main effect of observed motion-speed during video playback on a time production task and b) the interactive effect of the frame rate (frames per second; fps) and motion-speed during video playback on a time production task. No main effect of video playback-speed or interactive effect between video playback-speed and frame rate was found on time production.

  18. Is a perceived supportive physical environment important for self-reported leisure time physical activity among socioeconomically disadvantaged women with poor psychosocial characteristics? An observational study.

    PubMed

    Cleland, Verity J; Ball, Kylie; Crawford, David

    2013-03-27

    Over the past decade, studies and public health interventions that target the physical environment as an avenue for promoting physical activity have increased in number. While it appears that a supportive physical environment has a role to play in promoting physical activity, social-ecological models emphasise the importance of considering other multiple levels of influence on behaviour, including individual (e.g. self-efficacy, intentions, enjoyment) and social (e.g. social support, access to childcare) factors (psychosocial factors). However, not everyone has these physical activity-promoting psychosocial characteristics; it remains unclear what contribution the environment makes to physical activity among these groups. This study aimed to examine the association between the perceived physical environment and self-reported leisure-time physical activity (LTPA) among women living in socioeconomically disadvantaged areas demonstrating different psychosocial characteristics. In 2007-8, 3765 women (18-45 years) randomly selected from low socioeconomic areas in Victoria, Australia, self-reported LTPA, and individual, social and physical environmental factors hypothesised within a social-ecological framework to influence LTPA. Psychosocial and environment scores were created. Associations between environment scores and categories of LTPA (overall and stratified by thirds of perceived environment scores) were examined using generalised ordered logistic regression. Women with medium and high perceived environment scores had 20-38% and 44-70% greater odds respectively of achieving higher levels of LTPA than women with low environment scores. When stratified by thirds of psychosocial factor scores, these associations were largely attenuated and mostly became non-significant. However, women with the lowest psychosocial scores but medium or high environment scores had 76% and 58% higher odds respectively of achieving ≥120 minutes/week (vs. <120 minutes/week) LTPA

  19. Enceladus Plume Structure and Time Variability: Comparison of Cassini Observations.

    PubMed

    Teolis, Ben D; Perry, Mark E; Hansen, Candice J; Waite, J Hunter; Porco, Carolyn C; Spencer, John R; Howett, Carly J A

    2017-09-01

    During three low-altitude (99, 66, 66 km) flybys through the Enceladus plume in 2010 and 2011, Cassini's ion neutral mass spectrometer (INMS) made its first high spatial resolution measurements of the plume's gas density and distribution, detecting in situ the individual gas jets within the broad plume. Since those flybys, more detailed Imaging Science Subsystem (ISS) imaging observations of the plume's icy component have been reported, which constrain the locations and orientations of the numerous gas/grain jets. In the present study, we used these ISS imaging results, together with ultraviolet imaging spectrograph stellar and solar occultation measurements and modeling of the three-dimensional structure of the vapor cloud, to constrain the magnitudes, velocities, and time variability of the plume gas sources from the INMS data. Our results confirm a mixture of both low and high Mach gas emission from Enceladus' surface tiger stripes, with gas accelerated as fast as Mach 10 before escaping the surface. The vapor source fluxes and jet intensities/densities vary dramatically and stochastically, up to a factor 10, both spatially along the tiger stripes and over time between flyby observations. This complex spatial variability and dynamics may result from time-variable tidal stress fields interacting with subsurface fissure geometry and tortuosity beyond detectability, including changing gas pathways to the surface, and fluid flow and boiling in response evolving lithostatic stress conditions. The total plume gas source has 30% uncertainty depending on the contributions assumed for adiabatic and nonadiabatic gas expansion/acceleration to the high Mach emission. The overall vapor plume source rate exhibits stochastic time variability up to a factor ∼5 between observations, reflecting that found in the individual gas sources/jets. Key Words: Cassini at Saturn-Geysers-Enceladus-Gas dynamics-Icy satellites. Astrobiology 17, 926-940.

  20. Enceladus Plume Structure and Time Variability: Comparison of Cassini Observations

    PubMed Central

    Perry, Mark E.; Hansen, Candice J.; Waite, J. Hunter; Porco, Carolyn C.; Spencer, John R.; Howett, Carly J. A.

    2017-01-01

    Abstract During three low-altitude (99, 66, 66 km) flybys through the Enceladus plume in 2010 and 2011, Cassini's ion neutral mass spectrometer (INMS) made its first high spatial resolution measurements of the plume's gas density and distribution, detecting in situ the individual gas jets within the broad plume. Since those flybys, more detailed Imaging Science Subsystem (ISS) imaging observations of the plume's icy component have been reported, which constrain the locations and orientations of the numerous gas/grain jets. In the present study, we used these ISS imaging results, together with ultraviolet imaging spectrograph stellar and solar occultation measurements and modeling of the three-dimensional structure of the vapor cloud, to constrain the magnitudes, velocities, and time variability of the plume gas sources from the INMS data. Our results confirm a mixture of both low and high Mach gas emission from Enceladus' surface tiger stripes, with gas accelerated as fast as Mach 10 before escaping the surface. The vapor source fluxes and jet intensities/densities vary dramatically and stochastically, up to a factor 10, both spatially along the tiger stripes and over time between flyby observations. This complex spatial variability and dynamics may result from time-variable tidal stress fields interacting with subsurface fissure geometry and tortuosity beyond detectability, including changing gas pathways to the surface, and fluid flow and boiling in response evolving lithostatic stress conditions. The total plume gas source has 30% uncertainty depending on the contributions assumed for adiabatic and nonadiabatic gas expansion/acceleration to the high Mach emission. The overall vapor plume source rate exhibits stochastic time variability up to a factor ∼5 between observations, reflecting that found in the individual gas sources/jets. Key Words: Cassini at Saturn—Geysers—Enceladus—Gas dynamics—Icy satellites. Astrobiology 17, 926–940. PMID:28872900

  1. Screening for seemingly healthy newborns with congenital cytomegalovirus infection by quantitative real-time polymerase chain reaction using newborn urine: an observational study

    PubMed Central

    Yamaguchi, Akira; Oh-ishi, Tsutomu; Arai, Takashi; Sakata, Hideaki; Adachi, Nodoka; Asanuma, Satoshi; Oguma, Eiji; Kimoto, Hirofumi; Matsumoto, Jiro; Fujita, Hidetoshi; Uesato, Tadashi; Fujita, Jutaro; Shirato, Ken; Ohno, Hideki; Kizaki, Takako

    2017-01-01

    Objective Approximately 8–10% of newborns with asymptomatic congenital cytomegalovirus (cCMV) infection develop sensorineural hearing loss (SNHL). However, the relationship between CMV load, SNHL and central nervous system (CNS) damage in cCMV infection remains unclear. This study aimed to examine the relationship between urinary CMV load, SNHL and CNS damage in newborns with cCMV infection. Study design The study included 23 368 newborns from two maternity hospitals in Saitama Prefecture, Japan. Urine screening for cCMV infection (quantitative real-time PCR) and newborn hearing screening (automated auditory brainstem response (AABR) testing) were conducted within 5 days of birth to examine the incidence of cCMV infection and SNHL, respectively. CNS damage was assessed by MRI of cCMV-infected newborns. Results The incidence of cCMV infection was 60/23 368 (0.257%; 95% CI 0.192% to 0.322%). The geometric mean urinary CMV DNA copy number in newborns with cCMV was 1.79×106 copies/mL (95% CI 7.97×105 to 4.02×106). AABR testing revealed abnormalities in 171 of the 22 229 (0.769%) newborns whose parents approved hearing screening. Of these 171 newborns, 22 had SNHL (12.9%), and 5 of these 22 were infected with cCMV (22.7%). Newborns with both cCMV and SNHL had a higher urinary CMV DNA copy number than newborns with cCMV without SNHL (p=0.036). MRI revealed CNS damage, including white matter abnormalities, in 83.0% of newborns with cCMV. Moreover, newborns with CNS damage had a significantly greater urinary CMV load than newborns without CNS damage (p=0.013). Conclusions We determined the incidence of cCMV infection and urinary CMV DNA copy number in seemingly healthy newborns from two hospitals in Saitama Prefecture. SNHL and CNS damage were associated with urinary CMV DNA copy number. Quantification of urinary CMV load may effectively predict the incidence of late-onset SNHL and neurodevelopmental disorders. PMID:28110288

  2. Observational study of terrestrial eigenvibrations

    NASA Astrophysics Data System (ADS)

    Hansen, Roger A.

    1982-03-01

    A comprehensive analysis has been made of analog and digital recordings of eigenvibration ground motion obtained following four great earthquakes; August 1976 (Philippines), August 1977 (Indonesia), September 1979 (West Irian), and December 1979 (Colombia). The time series (ranging in length from ˜28 to ˜140 h) are assumed to be linear combinations of damped harmonics in the presence of noise. Tables are calculated from values of the four parameters: Θ, used in describing eigenvibrations, period of oscillation, amplitude, damping factor Q, and phase together with their statistical uncertainties (53 spheroidal modes, 0S 4to0S 48, and 13 torsional modes, 0T 8to0T 45). The estimation procedures are by the methods of complex demodulation and non-linear regression that specifically incorporate into the basic model the decaying aspect of the oscillations. These methods, extended to simultaneous estimations of groups of modes, help to eliminate measurement error and measurement bias from estimations of Θ. The result is that overtone modes very near in frequency to fundamental modes can, under certain conditions, be resolved through a non-linear regression technique, although parameter uncertainties are underestimated in general. Of the time series analyzed, 17 were from a northern California regional network of ultra-long period seismographs at Berkeley (three components), Jamestown (vertical component), and Whiskeytown (vertical component) following the four listed earthquakes. The other 7 time series were recorded digitally by the worldwide IDA network following the 1977 Indonesian earthquake. Weighted regional and worldwide averages were made for period and Q of each eigenvibration mode. From the theoretical viewpoint, comparisons of measured period, Q, amplitude, and phase for all modes analyzed led to five conclusions. First, there are no detectable systematic shifts in period, Q, or phase of eigenvibrations within a region whose dimensions are less than a

  3. Global normal mode planetary wave activity: a study using TIMED/SABER observations from the stratosphere to the mesosphere-lower thermosphere

    NASA Astrophysics Data System (ADS)

    John, Sherine Rachel; Kumar, Karanam Kishore

    2016-12-01

    A comprehensive study of three normal mode travelling planetary waves, namely the quasi-16, -10 and -5 day waves, is carried out globally using 5 years (2003-2007) of TIMED/SABER temperature measurements from the stratosphere to the mesosphere-lower thermosphere (MLT) by employing the two dimensional Fourier decomposition technique. From preliminary analysis, it is found that significant amplitudes of normal modes are confined to wave numbers-2 (westward propagating modes) to 2 (eastward propagating modes). The westward propagating quasi 16-day waves with zonal wave number 1 (W1; W1 refers to westward propagating wave with zonal wave number 1) peaks over winter-hemispheric high latitudes with northern hemisphere (NH) having higher amplitudes as compared to their southern hemispheric (SH) counterpart. The W1 quasi 16-day waves exhibit a double peak structure in altitude over winter hemispheric high latitudes. The eastward propagating quasi 16-day waves with wave number 1 (E1; E1 refers to eastward propagating wave with zonal wave number 1) exhibits similar features as that of W1 waves in the NH. In contrast, the E1 quasi 16-day waves in the SH show larger amplitudes as compared to the W1 waves and they do not exhibit double peak structure in altitude. Similar to the quasi 16-day waves, the quasi 10- and 5-day wave amplitudes with respect to their wavenumbers are delineated. Unlike quasi-16 and -10 day waves, quasi-5 day waves peak during vernal equinox both in the SH and NH. The peak activity of the W1 quasi-5 day wave is centered around 40°N and 40°S exhibiting symmetry with respect to the equator. A detailed discussion on the height-latitude structure, interannual variability and inter-hemispheric propagation of quasi 16-, 10- and 5-day waves are discussed. The significance of the present study lies in establishing the 5-year climatology of normal mode planetary waves from the stratosphere to the MLT region including their spatial-temporal evolution, which are

  4. Effects of self-reported age at nonsurgical menopause on time to first fracture and bone mineral density in the Women's Health Initiative Observational Study.

    PubMed

    Sullivan, Shannon D; Lehman, Amy; Thomas, Fridtjof; Johnson, Karen C; Jackson, Rebecca; Wactawski-Wende, Jean; Ko, Marcia; Chen, Zhao; Curb, J David; Howard, Barbara V

    2015-10-01

    Menopause is a risk factor for fracture; thus, menopause age may affect bone mass and fracture rates. We compared bone mineral density (BMD) and fracture rates among healthy postmenopausal women with varying ages at self-reported nonsurgical menopause. We compared hazard ratios for fractures and differences in BMD among 21,711 postmenopausal women from the Women's Health Initiative Observational Study cohort who had no prior hysterectomy, oophorectomy, or hormone therapy and had varying self-reported ages at menopause (<40, 40-49, or ≥50 y). Before multivariable adjustments, we found no differences in absolute fracture risk among menopause age groups. After multivariable adjustments for known risk factors for fracture, women who underwent menopause before age 40 years had a higher fracture risk at any site compared with women who underwent menopause at age 50 years or older (hazard ratio, 1.21; 95% CI, 1.02 to 1.44; P = 0.03). In a subset with BMD measurements (n = 1,351), whole-body BMD was lower in women who reported menopause before age 40 years than in women who reported menopause at ages 40 to 49 years (estimated difference, -0.034 g/cm; 95% CI, -0.07 to -0.004; P = 0.03) and women who reported menopause at age 50 years or older (estimated difference, -0.05 g/cm; 95% CI, -0.08 to -0.02; P < 0.01). Left hip BMD was lower in women who underwent menopause before age 40 years than in women who underwent menopause at age 50 years or older (estimated difference, -0.05 g/cm; 95% CI, -0.08 to -0.01; P = 0.01), and total spine BMD was lower in women who underwent menopause before age 40 years than in women who underwent menopause at age 50 years or older (estimated difference, -0.11 g/cm; 95% CI, -0.16 to -0.06; P < 0.01) and women who underwent menopause at ages 40 to 49 years (estimated difference, -0.09 g/cm; 95% CI, -0.15 to -0.04; P < 0.01). In the absence of hormone therapy, younger age at menopause may be a risk factor

  5. Timing and Location of Medical Emergency Team Activation Is Associated with Seriousness of Outcome: An Observational Study in a Tertiary Care Hospital

    PubMed Central

    Kurita, Takeo; Nakada, Taka-aki; Kawaguchi, Rui; Shinozaki, Koichiro; Abe, Ryuzo; Oda, Shigeto

    2016-01-01

    Purpose The medical emergency team (MET) can be activated anytime and anywhere in a hospital. We hypothesized the timing and location of MET activation are associated with seriousness of outcome. Materials and Methods We tested for an association of clinical outcomes with timing and location using a university hospital cohort in Japan (n = 328). The primary outcome was short-term serious outcome (unplanned ICU admission after MET activation or death at scene). Results Patients for whom the MET was activated in the evening or night-time had significantly higher rates of short-term serious outcome than those for whom it was activated during the daytime (vs. evening: adjusted OR = 2. 53, 95% CI = 1.24–5.13, P = 0.010; night-time: adjusted OR = 2.45, 95% CI = 1.09–5.50, P = 0.030). Patients for whom the MET was activated in public space had decreased short-term serious outcome compared to medical spaces (public space: adjusted OR = 0.19, 95% CI = 0.07–0.54, P = 0.0017). Night-time (vs. daytime) and medical space (vs. public space) were significantly associated with higher risks of unexpected cardiac arrest and 28-day mortality. Conclusions Patients for whom the MET was activated in the evening/night-time, or in medical space, had a higher rate of short-term serious outcomes. Taking measures against these risk factors may improve MET performance. PMID:28030644

  6. Peer Observation: A Pilot Study.

    ERIC Educational Resources Information Center

    Einwaechter, Nelson Frederick, Jr.

    This thesis describes a peer observation program implemented among American and Japanese teachers in the English Department of Hiroshima College of Foreign Languages, a two-year vocational college in Hiroshima, Japan. Each participant functioned as both an observer and observee, while pre- and post-observation meetings were held between the…

  7. Aerosol observations for climate studies

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.

    1985-01-01

    The Stratospheric Aerosol Measurement II and Stratospheric Aerosol and Gas Experiment satellite systems have provided to date more than five years and almost three years, respectively, of data on atmospheric aerosol profiles on a near-global scale. Studies with these unique data sets are developing a global aerosol climatology for the first time and have shown the existence and quantification of polar stratospheric clouds and tropical stratospheric cirrus. In addition, a tropospheric cirrus climatology is evolving. Since these two experiments were launched, a series of large volcanic eruptions have occurred which have greatly impacted the stratospheric aerosol loading. The aerosol layer produced by the eruption of El Chichon, for example, increased the 30 mb temperatures in the northern tropics by as much as 4 C for six months after the eruption. This paper describes in detail, from a climate perspective, the evolving aerosol and cloud climatologies as a function of space and time, and shows the stratospheric dynamics of volcanic injections and their enhancements on stratospheric optical depth and mass loading.

  8. The Classroom Experiences of Pupils with Special Educational Needs in Mainstream Primary Schools--1976 to 2012. What Do Data from Systematic Observation Studies Reveal about Pupils' Educational Experiences over Time?

    ERIC Educational Resources Information Center

    Webster, Rob

    2015-01-01

    This paper presents results of an analysis of primary-aged pupils' educational experiences over a 35 year period. Data drawn from a set of large-scale systematic observation studies, conducted in the UK between 1976 and 2012, are used to describe pupils' average classroom experiences at six points in time over this period. These data are then used…

  9. The Classroom Experiences of Pupils with Special Educational Needs in Mainstream Primary Schools--1976 to 2012. What Do Data from Systematic Observation Studies Reveal about Pupils' Educational Experiences over Time?

    ERIC Educational Resources Information Center

    Webster, Rob

    2015-01-01

    This paper presents results of an analysis of primary-aged pupils' educational experiences over a 35 year period. Data drawn from a set of large-scale systematic observation studies, conducted in the UK between 1976 and 2012, are used to describe pupils' average classroom experiences at six points in time over this period. These data are then used…

  10. High time resolutions observations of Cygnus X-3 with EXOSAT

    NASA Astrophysics Data System (ADS)

    Berger, M.; van der Klis, M.

    1994-12-01

    We have studied the fast timing behavior of Cygnus X-3 using the entire EXOSAT ME dataset on this source, consisting of 22 observations that cover a total of 320 000 seconds. This large amount of data allowed us to measure the rapid (greater than 1 Hz) X-ray variability of the source to an unprecedented accuracy of 0.2% fractional rms amplitude. Above 256 Hz, the power of the X-ray count rate fluctuations is significantly below the level predicted from Poisson statistics modified by the known dead time processes in the instrument. We developed an improved empirical method for predicting the Poisson level in EXOSAT ME High Time Resolution 3 (HTR3) and HTR5 data, and use it in our present analysis. None of the four other X-ray sources studied had a weaker noise-component in the region 1-256 Hz as the power spectra of Cygnus X-3. An instrumental effect could therefore not be excluded. If the effect is instrumental, the 99% confidence upper limit on the 1-256 Hz rapid variability of Cygnus X-3 is 0.6% rms. The consequences of these results for previously reported EXOSAT HTR observations are briefly discussed. We compare our results to the predictions of the stellar wind model for Cygnus X-3. Monte Carlo simulations were carried out to investigate the signal-attenuating effect of the wind. For the most likely wind parameters, the intrinsic source variability is found to be either very strong (approximately 60% rms), unlike seen in any other X-ray source at similar luminosity, or to be less than or approximately 12%, which would be consistent with a black hole candidate in the high state, or a low magnetic field neutron star.

  11. Real Time Monitoring of Flooding from Microwave Satellite Observations

    NASA Technical Reports Server (NTRS)

    Galantowicz, John F.; Frey, Herb (Technical Monitor)

    2002-01-01

    We have developed a new method for making high-resolution flood extent maps (e.g., at the 30-100 m scale of digital elevation models) in real-time from low-resolution (20-70 km) passive microwave observations. The method builds a "flood-potential" database from elevations and historic flood imagery and uses it to create a flood-extent map consistent with the observed open water fraction. Microwave radiometric measurements are useful for flood monitoring because they sense surface water in clear-or-cloudy conditions and can provide more timely data (e.g., compared to radars) from relatively wide swath widths and an increasing number of available platforms (DMSP, ADEOS-II, Terra, NPOESS, GPM). The chief disadvantages for flood mapping are the radiometers' low resolution and the need for local calibration of the relationship between radiances and open-water fraction. We present our method for transforming microwave sensor-scale open water fraction estimates into high-resolution flood extent maps and describe 30-day flood map sequences generated during a retrospective study of the 1993 Great Midwest Flood. We discuss the method's potential improvement through as yet unimplemented algorithm enhancements and expected advancements in microwave radiometry (e.g., improved resolution and atmospheric correction).

  12. Optimal observation time window for forecasting the next earthquake

    SciTech Connect

    Omi, Takahiro; Shinomoto, Shigeru; Kanter, Ido

    2011-02-15

    We report that the accuracy of predicting the occurrence time of the next earthquake is significantly enhanced by observing the latest rate of earthquake occurrences. The observation period that minimizes the temporal uncertainty of the next occurrence is on the order of 10 hours. This result is independent of the threshold magnitude and is consistent across different geographic areas. This time scale is much shorter than the months or years that have previously been considered characteristic of seismic activities.

  13. Observation of infiltration experiments with time lapse electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Noell, Ursula; Ganz, Christina; Altfelder, Sven; Günther, Thomas; Duijnisveld, Wilhelmus; Grissemann, Christoph

    2010-05-01

    Recent progress in the development of resistivity equipment enables the real time observation of infiltration processes through the vadose zone. In order to study the advantages and limitations of the method infiltration experiments are carried out for different soil types at various locations. All sites are subsequently excavated and investigated in detail. For an improved verification of the resistivity data the most recent experiment is conducted using a colour tracer. Two infiltration experiments are carried out in sandy soil. The location is Fuhrberg, close to Hannover, Germany. The area has been intensively studied for soil research purposes for more than 30 years. During both infiltration experiments water (110 l/80 l) is infiltrated for a period of 4.5 h and 8 h, respectively, and the infiltration process is observed by ERT. The resistivity measurements are conducted using a 3D-dipole-dipole configuration with electrode distances of 20 cm in the centre of the infiltration field. The whole resistivity array consists of 200 and 300 electrodes, respectively. The second experiment uses increased electrode spacing in the border area in order to enable the resolution of the deeper groundwater table (3.5 m during the second experiment compared to about 1.2 m for the first experiment). Immediately after completion of the resistivity measurements TDR and tensiometer measurements are carried out in 5-8 slices of the excavated infiltration area over a period of several days. The colour tracer used during the second experiment clearly outlines the infiltration plume with sharp outer limits. The ERT inversion depicts the shape of the plume successfully. Time lapse ERT interpretation reveals the development of the plume in time. The combination of ERT interpretation and TDR measurements enables the construction of the relationship between water content and resistivity as reconstructed by ERT using an Archie approach. By using this function water content changes can be

  14. Lead Time Study,

    DTIC Science & Technology

    1982-05-01

    2 Findings and Analysis ........................................ 2 Conclusions and Summary ...................................... 10 ...Recommendations .............................................. 10 Appendix I Listing of Studies and Documents Reviewed ................ 12 Appendix 2...components were delivered by the contractor 10 -13 months after contract award. It should be noted that, in order to accomplish the 10 -13 months deliveries, the

  15. Tracing high time-resolution fluctuations in dissolved organic carbon using satellite and buoy observations: Case study in Lake Taihu, China

    NASA Astrophysics Data System (ADS)

    Huang, Changchun; Yunmei, Li; Liu, Ge; Guo, Yulong; Yang, Hao; Zhu, A.-xing; Song, Ting; Huang, Tao; Zhang, Mingli; Shi, Kun

    2017-10-01

    Field measurements of dissolved organic carbon (DOC) concentration and remote-sensing reflectance were conducted to develop a regional, empirical red-blue algorithm to retrieve surface DOC from Geostationary Ocean Color Imager (GOCI) data for Lake Taihu, China. The auxiliary data (in-situ observations of the optical properties and water quality, buoy measurements of hydrodynamic data and water chemical parameters) were used to investigate the spatial and temporal variations in DOC. GOCI was shown to be capable of successfully obtaining hourly variations in DOC, with a root mean square error percentage (RMSP) of 17.29% (RMSE = 0.69 mg/L) for the match-up data. The GOCI-derived DOC in Lake Taihu confirms that the highest DOC concentration is in northwest Lake Taihu, followed by Meiliang Bay, Gonghu Bay and northeast Lake Taihu. Hourly DOC variation is significant and presents a different trend for each lake segment due to the variety of influencing factors. Discharge of DOC from surrounding rivers is an important factor to the variation of DOC in northeast Lake Taihu. However, organic products of algae will be the primary contributor to DOC when algal bloom occurred. During the period of algal bloom, high DOC levels in Lake Taihu can lead to hypoxia when coupled with high temperatures and low disturbance.

  16. Observation of response strategies in cycling time trials.

    PubMed

    DeFrancesco, C; DeSario, L F

    1995-08-01

    Athletes in sprint events use various mental and physical starting strategies prior to beginning a race. Included among these strategies are sensory-set and motor-set strategies. A sensory-set strategy is one in which the athlete concentrates on reacting as fast as possible to an auditory or visual stimulus. A motor-set strategy is one in which the athlete consciously attends to a component of a well-learned skill rather than to the stimulus which evokes the initiation of the skill. The purpose of this study was to observe differences in starting techniques of 20 championship cyclist responded significantly faster after the auditory stimulus and recorded faster 1/2-lap split times than 10 proficient cyclists. Strategy selection and use of elite cyclists should be investigated further to examine efficient starting strategies and procedures.

  17. Ozone time scale decomposition and trend assessment from surface observations

    NASA Astrophysics Data System (ADS)

    Boleti, Eirini; Hueglin, Christoph; Takahama, Satoshi

    2017-04-01

    Emissions of ozone precursors have been regulated in Europe since around 1990 with control measures primarily targeting to industries and traffic. In order to understand how these measures have affected air quality, it is now important to investigate concentrations of tropospheric ozone in different types of environments, based on their NOx burden, and in different geographic regions. In this study, we analyze high quality data sets for Switzerland (NABEL network) and whole Europe (AirBase) for the last 25 years to calculate long-term trends of ozone concentrations. A sophisticated time scale decomposition method, called the Ensemble Empirical Mode Decomposition (EEMD) (Huang,1998;Wu,2009), is used for decomposition of the different time scales of the variation of ozone, namely the long-term trend, seasonal and short-term variability. This allows subtraction of the seasonal pattern of ozone from the observations and estimation of long-term changes of ozone concentrations with lower uncertainty ranges compared to typical methodologies used. We observe that, despite the implementation of regulations, for most of the measurement sites ozone daily mean values have been increasing until around mid-2000s. Afterwards, we observe a decline or a leveling off in the concentrations; certainly a late effect of limitations in ozone precursor emissions. On the other hand, the peak ozone concentrations have been decreasing for almost all regions. The evolution in the trend exhibits some differences between the different types of measurement. In addition, ozone is known to be strongly affected by meteorology. In the applied approach, some of the meteorological effects are already captured by the seasonal signal and already removed in the de-seasonalized ozone time series. For adjustment of the influence of meteorology on the higher frequency ozone variation, a statistical approach based on Generalized Additive Models (GAM) (Hastie,1990;Wood,2006), which corrects for meteorological

  18. Science Studies from Archived Observations

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  19. Linear system identification via backward-time observer models

    NASA Technical Reports Server (NTRS)

    Juang, Jer-Nan; Phan, Minh Q.

    1992-01-01

    Presented here is an algorithm to compute the Markov parameters of a backward-time observer for a backward-time model from experimental input and output data. The backward-time observer Markov parameters are decomposed to obtain the backward-time system Markov parameters (backward-time pulse response samples) for the backward-time system identification. The identified backward-time system Markov parameters are used in the Eigensystem Realization Algorithm to identify a backward-time state-space model, which can be easily converted to the usual forward-time representation. If one reverses time in the model to be identified, what were damped true system modes become modes with negative damping, growing as the reversed time increases. On the other hand, the noise modes in the identification still maintain the property that they are stable. The shift from positive damping to negative damping of the true system modes allows one to distinguish these modes from noise modes. Experimental results are given to illustrate when and to what extent this concept works.

  20. The Effect of Pulsar Timing Noise and Glitches on Timing Analysis for Ground Based Telescopes Observation

    NASA Astrophysics Data System (ADS)

    Oña-Wilhelmi, E.; de Jager, O. C.; Contreras, J. L.; de los Reyes, R.; Fonseca, V.; López, M.; Lucarelli, F.; MAGIC Collaboration

    2003-07-01

    Pulsed emission from a number of gamma-ray pulsars is expected to be detectable with next generation ground-based gamma-ray telescopes such as MAGIC and possibly H.E.S.S. within a few hours of observations. The sensitivity is however not sufficient to enable a detection within a few seconds as reached by radio surveys. In some cases we may be fortunate to do a period search given a few hours' data, but if the signal is marginal, the correct period parameters must be known to allow a folding of the gamma-ray arrival times. The residual phases are then sub jected to a test for uniformity from which the significance of a signal can be assessed. If contemporary radio parameters are not available, we have to extrap olate archival radio parameters to the observation time in question. Such an extrap olation must then be accurate enough to avoid significant pulse smearing. The pulsar ephemerides from the archival data of HartRAO and Princeton (b etween 1989 and 1998) provide an excellent opportunity to study the accuracy of extrap olations of such ephemerides to the present moment, if an appropriate time shift is intro duced. The aim of this study is to investigate the smear in the gamma-ray pulse profile during a single night of observations.

  1. Finite-Time Control by Observer-Based Output Feedback for Linear Discrete-Time Systems

    NASA Astrophysics Data System (ADS)

    Ichihara, Hiroyuki; Katayama, Hitoshi

    In this paper we consider finite-time stabilization and finite-time boundedness control problems for time-varying discrete-time systems. We give a set of sufficient conditions, in terms of difference LMIs, for the existence of observer-based output feedback controllers that make the system finite-time stable and finite-time bounded. We then reduce the obtained results to the ones for time-invariant discrete-time systems and derive numerically tractable sufficient conditions given by LMIs. We also show numerical examples to illustrate the design methods of observer-based output feedback controllers.

  2. RXTE Observation of Cygnus X-1. Report 2; TIming Analysis

    NASA Technical Reports Server (NTRS)

    Nowak, Michael A.; Vaughan, Brian A.; Wilms, Joern; Dove, James B.; Begelman, Mitchell C.

    1998-01-01

    We present timing analysis for a Rossi X-ray Timing Explorer (RXTE) observation of Cygnus X-1 in its hard/low state. This was the first RXTE observation of Cyg X-1 taken after it transited back to this state from its soft/high state. RXTE's large effective area, superior timing capabilities, and ability to obtain long, uninterrupted observations have allowed us to obtain measurements of the power spectral density (PSD), coherence function, and Fourier time lags to a decade lower in frequency and half a decade higher in frequency than typically was achieved with previous instruments. Notable aspects of our observations include a weak 0.005 Hz feature in the PSD coincident with a coherence recovery; a 'hardening' of the high-frequency PSD with increasing energy; a broad frequency range measurement of the coherence function, revealing rollovers from unity coherence at both low and high frequency; and an accurate determination of the Fourier time lags over two and a half decades in frequency. As has been noted in previous similar observations, the time delay is approximately proportional to f(exp -0.7), and at a fixed Fourier frequency the time delay of the hard X-rays compared to the softest energy channel tends to increase logarithmically with energy. Curiously, the 0.01-0.2 Hz coherence between the highest and lowest energy bands is actually slightly greater than the coherence between the second highest and lowest energy bands. We carefully describe all of the analysis techniques used in this paper, and we make comparisons of the data to general theoretical expectations. In a companion paper, we make specific comparisons to a Compton corona model that we have successfully used to describe the energy spectral data from this observation.

  3. The relationship between knowledge of pain neurophysiology and fear avoidance in people with chronic pain: A point in time, observational study.

    PubMed

    Fletcher, Claire; Bradnam, Lynley; Barr, Christopher

    2016-05-01

    Chronic pain is prevalent in the western world; however fear of pain often has a greater impact than the degree of initial injury. The aim of this study was to explore the relationship between knowledge of the neurophysiology of pain and fear avoidance in individuals diagnosed with chronic pain. Twenty-nine people with chronic musculoskeletal pain were recruited and completed questionnaires to determine their understanding of pain neurophysiology and the degree of their fear avoidance beliefs. There was an inverse relationship between knowledge of pain neurophysiology and the level of fear avoidance. Patients with higher pain knowledge reported less fear avoidance and lower perceived disability due to pain. There was no relationship with the educational level or compensable status for either variable. The findings suggest that fear avoidance is positively influenced by neurophysiology of pain education, so that a higher level of pain knowledge is associated with less activity-related fear. The clinical implication is that reducing fear avoidance/kinesiophobia using neurophysiology of pain education in people with chronic pain may provide an effective strategy to help manage fear avoidance and related disability in the chronic pain population in order to improve treatment outcomes.

  4. Arrival Time Distribution by the New Observation System at Taro

    NASA Astrophysics Data System (ADS)

    Sakuyama, H.; Obara, Hitoshi; Kuramochi, Hiroshi; Ono, Shunichi; Origasa, Satoru; Mochida, Akinori; Sakuyama, Hiroshi; Suzuki, Noboru

    2003-07-01

    The arrival time distribution of EAS has been observed by using Ultra Fast Cherenkov detector (UFC) and oscilloscope at Taro observatory since 1995 (sea level 200m). The EAS array is arranged 169 sets of 0.25m2 scintillation detectors in the shape of a lattice at intervals of 1.5m and about 40 scintillation detectors which consists of 1m2 and 0.25m2 is arranged in the peripheral part. Then, it consists of 8 fast timing detectors. The UFC detector is installed in the palce of about 20m from the trigger center. The observation system of a UFC detector was changed from the autumn of 2000. The outline of a new observation system and EAS arrival time distribution are reported.

  5. Observing real time motion of nano-scale objects

    NASA Astrophysics Data System (ADS)

    van de Vondel, Joris; Timmermans, Matias; Samuely, Tomás; Raes, Bart; Serrier-Garcia, Lise; Moshchalkov, Victor

    2015-03-01

    The dynamics of nanoscale objects is a very interesting field of research with a strong technological impact. Still, the combination of a technique resolving (sub)nanometer particles within a time frame relevant to observe dynamics is a very challenging task. Due to the inherent atomic-scale resolution, scanning tunneling microscopy (STM) is an ideal candidate to achieve this goal. Nevertheless, in most physical systems the dynamic events of the objects under investigation cannot be resolved by conventional STM image acquisition and will only reveal an average trace of the moving object. This is why a strong drive exists to develop new functionalities of STM, which allow studying dynamic events at the nanoscale. We address this issue, for vortex matter in NbSe2, by driving the vortices using an ac magnetic field and probing the induced periodic tunnel current modulations. Our results reveal different dynamical modes of the driven vortex lattice. In addition, by extending a known functionality of STM, (i.e. the `Lazy Fisherman' technique) we can use single pixel information to obtain the overall dynamics of the vortex lattice with submillisecond time resolution and subnanometer spatial resolution. This work is supported by the FWO and the Methusalem funding of the Flemish government.

  6. Local-time Variation of Nitric Oxide: Modeling and Observations

    NASA Astrophysics Data System (ADS)

    Lin, C. Y. T.; Bailey, S. M.; Yonker, J. D.; Venkataramani, K.; Deng, Y.

    2014-12-01

    NO, a minor species in the thermosphere, is an important indicator of energy balance. It also has the lowest ionization threshold so is the terminal ion in the ionospheric E-region. Solar soft X-ray energy between 0.1 and 7 nm is absorbed mostly in the lower thermosphere between 100 and 150 km. Photoelectrons are created and initiate chains of photochemical reactions which leads to the production of nitric oxide (NO). On the other hand, solar irradiance longer than 150 nm destroys NO. In this study, observation of the local-time variation of NO abundance in the lower thermosphere is derived from the Remote Atmospheric and Ionospheric Detection System (RAIDS) measurements in summer 2010. Soft X-ray and EUV irradiance from the Extreme ultraviolet Variability Experiment (EVE) on the Solar Dynamic Observatory (SDO) is used to drive the NOx1D model during the same period of time. By comparing variation of NO abundance at local sunlit hours, the effects of solar irradiance on thermospheric NO photochemistry in the model are examined.

  7. Inflow rate, a time-symmetric observable obeying fluctuation relations.

    PubMed

    Baiesi, Marco; Falasco, Gianmaria

    2015-10-01

    While entropy changes are the usual subject of fluctuation theorems, we seek fluctuation relations involving time-symmetric quantities, namely observables that do not change sign if the trajectories are observed backward in time. We find detailed and integral fluctuation relations for the (time-integrated) difference between entrance rate and escape rate in mesoscopic jump systems. Such inflow rate, which is even under time reversal, represents the discrete-state equivalent of the phase-space contraction rate. Indeed, it becomes minus the divergence of forces in the continuum limit to overdamped diffusion. This establishes a formal connection between reversible deterministic systems and irreversible stochastic ones, confirming that fluctuation theorems are largely independent of the details of the underling dynamics.

  8. JPL pulsar timing observations. IV - Excess phase noise

    NASA Technical Reports Server (NTRS)

    Downs, G. S.; Krause-Polstorff, J.

    1986-01-01

    Previously published tables of geocentric arrival times for 24 pulsars covering a 12 year span are extended here to 14.5 years. The list of pulsars is extended by nine, most of which were observed for about 4 years. Known positins of these new objects are confirmed, and limits on the proper motions are obtained. Large phase excursions in PSR 0525 + 21 are found. The orbital parameters of the binary pulsar 0820 + 02 are tentatively confirmed. Short-term timing noise in excess of that expected from receiver considerations alone is established. Variations in the timing residuals for the original 24 pulsars are analyzed for correlations with other observable parameters. Little significant correlation with changes in pulse shape or energy or with the drift correction is found on time scales of 500 pulses or longer.

  9. Late time observations of candidate high-z GRBs

    NASA Astrophysics Data System (ADS)

    Burlon, Davide; Gaensler, Bryan; Murphy, Tara; Hancock, Paul; Ghirlanda, Giancarlo; Salvaterra, Ruben; Ghisellini, Gabriele; Tagliaferri, Gianpiero

    2014-04-01

    This is a discovery (NAPA) proposal to detect the late time radio afterglow of candidates high redshift gamma ray bursts (GRBs). Our selection criteria (no redshift information at the time of the request, type of trigger, high-energy flux and duration) are based on information immediately available through the Swift/BAT telescope and ground based telescopes. Radio observations play a crucial role in determining the energetics of the GRB explosion, and will therefore directly point towards exceptional progenitors.

  10. Time Delays of Blazar Flares Observed at Different Wavebands

    NASA Technical Reports Server (NTRS)

    Marscher, Alan P.

    2001-01-01

    Correlated variability at different frequencies can probe the structure and physics of the jet of a blazar on size scales much smaller than can be resolved by telescopes and interferometers. I discuss some observations of frequency dependent time lags and how these place constraints on models for the nonthermal emission in blazars. The time lags can be either positive (high frequency variations leading those at lower frequencies) or negative, while simultaneous flares are also possible.

  11. Time Delays of Blazar Flares Observed at Different Wavebands

    NASA Technical Reports Server (NTRS)

    Marscher, Alan P.

    2000-01-01

    Correlated variability at different frequencies can probe the structure and physics of the jet of a blazar on size scales much smaller than can be resolved by telescopes and interferometers. I discuss some observations of frequency dependent time lags and how these place constraints on models for the nonthermal emission in blazars. The time lags can be either positive (high frequency variations leading those at lower frequencies) or negative, while simultaneous flares are also possible.

  12. Global Night-Time Lights for Observing Human Activity

    NASA Technical Reports Server (NTRS)

    Hipskind, Stephen R.; Elvidge, Chris; Gurney, K.; Imhoff, Mark; Bounoua, Lahouari; Sheffner, Edwin; Nemani, Ramakrishna R.; Pettit, Donald R.; Fischer, Marc

    2011-01-01

    We present a concept for a small satellite mission to make systematic, global observations of night-time lights with spatial resolution suitable for discerning the extent, type and density of human settlements. The observations will also allow better understanding of fine scale fossil fuel CO2 emission distribution. The NASA Earth Science Decadal Survey recommends more focus on direct observations of human influence on the Earth system. The most dramatic and compelling observations of human presence on the Earth are the night light observations taken by the Defence Meteorological System Program (DMSP) Operational Linescan System (OLS). Beyond delineating the footprint of human presence, night light data, when assembled and evaluated with complementary data sets, can determine the fine scale spatial distribution of global fossil fuel CO2 emissions. Understanding fossil fuel carbon emissions is critical to understanding the entire carbon cycle, and especially the carbon exchange between terrestrial and oceanic systems.

  13. Towards Near Real-time Convective Rainfall Observations over Kenya

    NASA Astrophysics Data System (ADS)

    Hoedjes, Joost; Said, Mohammed; Becht, Robert; Kifugo, Shem; Kooiman, André; Limo, Agnes; Maathuis, Ben; Moore, Ian; Mumo, Mark; Nduhiu Mathenge, Joseph; Su, Bob; Wright, Iain

    2013-04-01

    The existing meteorological infrastructure in Kenya is poorly suited for the countrywide real-time monitoring of precipitation. Rainfall radar is not available, and the existing network of rain gauges is sparse and challenging to maintain. This severely restricts Kenya's capacity to warn for, and respond to, weather related emergencies. Furthermore, the lack of accurate rainfall observations severely limits Kenya's climate change adaptation capabilities. Over the past decade, the mobile telephone network in Kenya has expanded rapidly. This network makes extensive use of terrestrial microwave (MW) links, received signal level (RSL) data from which can be used for the calculation of rainfall intensities. We present a novel method for the near-real time observation of convective rainfall over Kenya, based on the combined use of MW RSL data and Meteosat Second Generation (MSG) satellite data. In this study, the variable density rainfall information derived from several MW links is scaled up using MSG data to provide full rainfall information coverage for the region surrounding the links. Combining MSG data and MW link derived rainfall data for several adjacent MW links makes it possible to make the distinction between wet and dry pixels. This allows the disaggregation of the MW link derived rainfall intensities. With the distinction between wet and dry pixels made, and the MW derived rainfall intensities disaggregated, these data can then be used to develop instantaneous empirical relationships linking rainfall intensities to cloud physical properties. These relationships are then used to calculate rainfall intensities for the MSG scene. Since both the MSG and the MW data are available at the same temporal resolution, unique empirical coefficients can be determined for each interval. This approach ensures that changes in convective conditions from one interval to the next are taken into account. Initial results from a pilot study, which took place from November 2012

  14. Timing the Geminga Pulsar with Gamma-Ray Observations

    NASA Technical Reports Server (NTRS)

    Mattox, J. R.; Halpern, Jules P.; Caraveo, P. A.; Oliversen, Ronald (Technical Monitor)

    2001-01-01

    We present the COS-B/EGRET 1997 ephemeris for the rotation of the Geminga pulsar. This ephemeris is derived from high-energy gamma-ray observations that span 24 yr. The recently obtained accurate position and proper motion are assumed. A cubic ephemeris predicts the rotational phase of Geminga with errors smaller than 50 milliperiods for all existing high-energy gamma-ray observations that span a 24.2 yr timing baseline. The braking index obtained is 17 +/- 1. Further observation is required to ascertain whether this high value truly reflects the rotational energy loss mechanism, or whether it is a manifestation of timing noise. The ephemeris parameters are sufficiently constrained so that timing noise will be the limitation on forward extrapolation. If Geminga continues to rotate without a glitch, as it has for at least 23 yr, we expect this ephemeris to continue to describe the phase, with an error of less than 100 milliperiods, until 2008. Statistically significant timing residuals are detected in the EGRET data that depart from the cubic ephemeris at a level of 30 milliperiods. Although this could simply be an additional manifestation of timing noise, the EGRET timing residuals appear to have a sinusoidal modulation that is consistent with a planet of mass 1.7/sin i solar mass, orbiting Geminga at a radius of 3.3 AU.

  15. Timing the Geminga Pulsar with Gamma-Ray Observations

    NASA Technical Reports Server (NTRS)

    Mattox, J. R.; Halpern, Jules P.; Caraveo, P. A.; Oliversen, Ronald (Technical Monitor)

    2001-01-01

    We present the COS-B/EGRET 1997 ephemeris for the rotation of the Geminga pulsar. This ephemeris is derived from high-energy gamma-ray observations that span 24 yr. The recently obtained accurate position and proper motion are assumed. A cubic ephemeris predicts the rotational phase of Geminga with errors smaller than 50 milliperiods for all existing high-energy gamma-ray observations that span a 24.2 yr timing baseline. The braking index obtained is 17 +/- 1. Further observation is required to ascertain whether this high value truly reflects the rotational energy loss mechanism, or whether it is a manifestation of timing noise. The ephemeris parameters are sufficiently constrained so that timing noise will be the limitation on forward extrapolation. If Geminga continues to rotate without a glitch, as it has for at least 23 yr, we expect this ephemeris to continue to describe the phase, with an error of less than 100 milliperiods, until 2008. Statistically significant timing residuals are detected in the EGRET data that depart from the cubic ephemeris at a level of 30 milliperiods. Although this could simply be an additional manifestation of timing noise, the EGRET timing residuals appear to have a sinusoidal modulation that is consistent with a planet of mass 1.7/sin i solar mass, orbiting Geminga at a radius of 3.3 AU.

  16. Spectral models for early time SN 2011fe observations

    NASA Astrophysics Data System (ADS)

    Baron, E.; Hoeflich, P.; Friesen, Brian; Sullivan, M.; Hsiao, E.; Ellis, R. S.; Gal-Yam, A.; Howell, D. A.; Nugent, P. E.; Dominguez, I.; Krisciunas, K.; Phillips, M. M.; Suntzeff, N.; Wang, L.; Thomas, R. C.

    2015-12-01

    We use observed UV through near-IR spectra to examine whether SN 2011fe can be understood in the framework of Branch-normal Type Ia supernovae (SNe Ia) and to examine its individual peculiarities. As a benchmark, we use a delayed-detonation model with a progenitor metallicity of Z⊙/20. We study the sensitivity of features to variations in progenitor metallicity, the outer density profile, and the distribution of radioactive nickel. The effect of metallicity variations in the progenitor have a relatively small effect on the synthetic spectra. We also find that the abundance stratification of SN 2011fe resembles closely that of a delayed-detonation model with a transition density that has been fit to other Branch-normal SNe Ia. At early times, the model photosphere is formed in material with velocities that are too high, indicating that the photosphere recedes too slowly or that SN 2011fe has a lower specific energy in the outer ≈0.1 M⊙ than does the model. We discuss several explanations for the discrepancies. Finally, we examine variations in both the spectral energy distribution and in the colours due to variations in the progenitor metallicity, which suggests that colours are only weak indicators for the progenitor metallicity, in the particular explosion model that we have studied. We do find that the flux in the U band is significantly higher at maximum light in the solar metallicity model than in the lower metallicity model and the lower metallicity model much better matches the observed spectrum.

  17. Observations of the rupture development process from source time functions

    NASA Astrophysics Data System (ADS)

    Renou, Julien; Vallée, Martin

    2017-04-01

    The mechanisms governing the seismic rupture expansion and leading to earthquakes of very different magnitudes are still under debate. In the cascade model, the rupture starts from a very small patch, which size is undetectable by seismological investigation. Then rupture grows in a self-similar way, implying that no clues about the earthquake magnitude can be found before rupture starts declining. However dependencies between early phases of the rupture process and final magnitude have also been proposed, which can be explained if an earthquake is more likely to be a big one when its start and early development occur in rupture-prone areas. Here, the analysis of the early phases of the seismic rupture is achieved from an observational point of view using the SCARDEC database, a global catalog containing more than 3000 Source Time Functions (STFs) of earthquakes with magnitude larger than 5.7. This dataset is theoretically very suitable to investigate the initial phase, because STFs directly describe the seismic moment rate released over time, giving access to the rupture growth behavior. As several studies already showed that deep earthquakes tend to have a specific signature of short duration with respect to magnitude (implying a quicker rupture growth than superficial events), only shallow events (depths < 70km) are analyzed here. Our method consists in computing the STFs slope, i.e. the seismic moment acceleration, at several prescribed moment rates. In order to ensure that the chosen moment rates intersect the growth phase of the STF, its value must be high enough to avoid the very beginning of the signal -not well constrained in the deconvolution process-, and low enough to avoid the proximity of the peak moment rate. This approach does not use any rupture time information, which is interesting as (1) the exact hypocentral time can be uncertain and (2) the real rupture expansion can be delayed compared to origin time. If any magnitude-dependent signal exists

  18. RHESSI Timing Studies: Multithermal Delays

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.

    2007-06-01

    We investigate the energy-dependent timing of thermal emission in solar flares using high-resolution spectra and demodulated time profiles from the RHESSI instrument. We model for the first time the spectral-temporal hard X-ray flux f(ɛ,t) in terms of a multitemperature plasma governed by thermal conduction cooling. In this quantitative model we characterize the multitemperature differential emission measure distribution (DEM) and nonthermal spectra with power-law functions. We fit this model to the spectra and energy-dependent time delays of a representative data set of 89 solar flares observed with RHESSI during 2002-2005. Eliminating weak flares, we find 65 events suitable for fitting and obtain in 44 events (68%) a satisfactory fit that is consistent with the theoretical model. The best-fit results yield a thermal-nonthermal crossover energy of ɛth=18.0+/-3.4 keV, nonthermal spectral indices of γnth=3.5+/-1.1 (at ~30-50 keV), thermal multispectral indices of γth=6.9+/-0.9 (at ~10-20 keV), and thermal conduction cooling times of τc0=101.6+/-0.6 s at ɛth=1 keV (or T0=11.6 MK), which scale with temperature as τc(T)~T-β with β=2.7+/-1.2, consistent with the theoretically expected scaling of τc(T)~T-5/2 for thermal conduction cooling. The (empirical) Neupert effect is consistent with this theoretical model in the asymptotic limit of long cooling times. This study provides clear evidence that all analyzed flares are consistent with the model of a multitemperature plasma distribution and with thermal conduction as dominant cooling mechanism (at flare temperatures of T>~10 MK). Our modeling of energy-dependent time delays provides an alternative method for separating multithermal from nonthermal spectral components based on information in the time domain, in contrast to previous spectral fitting methods.

  19. Computerized Systems for Collecting Real-Time Observational Data.

    ERIC Educational Resources Information Center

    Kahng, SungWoo; Iwata, Brian

    1998-01-01

    A survey of 15 developers of computerized real-time observation systems found many systems have incorporated laptop or handheld computers as well as bar-code scanners. Most systems used IBM-compatible software, and ranged from free to complete systems costing more than $1,500. Data analysis programs were included with most programs. (Author/CR)

  20. Computerized Systems for Collecting Real-Time Observational Data.

    ERIC Educational Resources Information Center

    Kahng, SungWoo; Iwata, Brian

    1998-01-01

    A survey of 15 developers of computerized real-time observation systems found many systems have incorporated laptop or handheld computers as well as bar-code scanners. Most systems used IBM-compatible software, and ranged from free to complete systems costing more than $1,500. Data analysis programs were included with most programs. (Author/CR)

  1. Late time observations of candidate high-z GRBs

    NASA Astrophysics Data System (ADS)

    Burlon, Davide; Gaensler, Bryan; Murphy, Tara; Hancock, Paul; Ghirlanda, Giancarlo; Salvaterra, Ruben; Ghisellini, Gabriele; Tagliaferri, Gianpiero

    2014-04-01

    This is a targeted proposal to detect late time radio afterglow of a sample of potentially high redshift gamma ray bursts (GRBs). Our targets have been selected from detections of the the last two years by the Swift/BAT telescope. Radio observations play a crucial role in determining the energetics of the GRB explosion, and will therefore directly point towards exceptional progenitors.

  2. Ionospheric observations made by a time-interleaved Doppler ionosonde

    NASA Astrophysics Data System (ADS)

    Lynn, Kenneth J. W.

    2008-10-01

    Mid-latitude HF observations of ionospheric Doppler velocity as a function of frequency are reported here as observed over a quiet 24-h period by a KEL IPS71 ionosonde operating at a 5-min sampling rate. The unique time-interleaving technique used in this ionosonde provided a Doppler resolution of 0.04 Hz over a Doppler range of ±2.5 Hz at each sounding frequency via FFT processing and is described here for the first time. The time-interleaving technique can be applied to other types of ionosonde as well as to other applications. The measurements described were made at a middle latitude site (Salisbury, South Australia). Doppler variations (<30 min) were ever present throughout the day and showed short-period TID characteristics. The day-time Doppler shift was found to closely follow the rate-of-change of foF2 as predicted by a simple parabolic layer model. The descending cusp in short-period TIDs is shown to mark an abrupt change with increasing frequency from negative towards positive Doppler shift with the greatest change in Doppler shift being observed below the cusp. The “smilergram” is introduced as observed in both F2 and Sporadic E. The characteristic curve in Doppler versus group height at a single frequency is described and related to changes in reflection symmetry, velocity and depth of moving ionospheric inhomogeneities.

  3. A roadside study of observable driver distractions.

    PubMed

    Sullman, Mark J M; Prat, Francesc; Tasci, Duygu Kuzu

    2015-01-01

    This study investigated the prevalence of observable distractions while driving and the effect of drivers' characteristics and time-related variables on their prevalence. Using roadside observation, 2 independent observers collected data at 4 randomly selected locations in St. Albans, UK. Of the 10,984 drivers observed, 16.8% were engaged in a secondary task, with talking to passengers being the most common distraction (8.8%), followed by smoking (1.9%) and talking on a hands-free mobile phone (1.7%). An additional 1.0% were observed talking on a handheld phone, and the rest of the distractions (e.g., texting, drinking) were recorded in less than 1% of the drivers observed. Gender-related differences were found for a number of different distractions (i.e., talking to passengers, drinking, and handheld mobile phone conversations), but age emerged as a significant predictor for most secondary tasks, including talking to passengers, smoking, hands-free mobile phone use, handheld mobile phone use, texting/keying numbers, drinking, and engagement in any type of distraction (all distractions combined). The overall pattern for age was that middle-aged and older drivers were less likely to be distracted than younger drivers. This work provides further evidence of the relatively high rate of distracted driving in the UK. The findings clearly indicate that younger drivers are more likely to drive distracted, which probably contributes to their higher crash rates.

  4. Technical and Observational Challenges for Future Time-Domain Surveys

    NASA Astrophysics Data System (ADS)

    Bloom, Joshua S.

    2012-04-01

    By the end of the last decade, robotic telescopes were established as effective alternatives to the traditional role of astronomer in planning, conducting and reducing time-domain observations. By the end of this decade, machines will play a much more central role in the discovery and classification of time-domain events observed by such robots. While this abstraction of humans away from the real-time loop (and the nightly slog of the nominal scientific process) is inevitable, just how we will get there as a community is uncertain. I discuss the importance of machine learning in astronomy today, and project where we might consider heading in the future. I will also touch on the role of people and organisations in shaping and maximising the scientific returns of the coming data deluge.

  5. Direct Observations of PMC Local Time Variations by Aura OMI

    NASA Technical Reports Server (NTRS)

    DeLand, Matthew T.; Shettle, Eric P.; Thomas, Gary E.; Olivero, John J.

    2010-01-01

    The Ozone Monitoring Instrument (OMI) on the Aura satellite obtains unique measurements for polar mesospheric cloud (PMC) analysis. Its wide cross-track viewing swath and high along-track spatial resolution makes it possible to directly evaluate PMC occurrence frequency and brightness variations between 6S" and 8S' latitude as a function of local time over a 12-14 h continuous period. OMI PMC local time variations are closely coupled to concurrent variations in measurement scattering angle, so that ice phase function effects must be considered when interpreting the observations. Two different phase functions corresponding to bright and faint clouds are examined in this analysis. OMI observations show maximum frequency and albedo values at 8-10 h local time in the Northern Hemisphere, with decreasing amplitude at higher latitudes. Southern Hemisphere values reach a minimum at 18-20 h LT. Larger variations are seen in Northern Hemisphere data. No statistically significant longitudinal dependence was seen.

  6. Direct Observations of PMC Local Time Variations by Aura OMI

    NASA Technical Reports Server (NTRS)

    DeLand, Matthew T.; Shettle, Eric P.; Thomas, Gary E.; Olivero, John J.

    2010-01-01

    The Ozone Monitoring Instrument (OMI) on the Aura satellite obtains unique measurements for polar mesospheric cloud (PMC) analysis. Its wide cross-track viewing swath and high along-track spatial resolution makes it possible to directly evaluate PMC occurrence frequency and brightness variations between 6S" and 8S' latitude as a function of local time over a 12-14 h continuous period. OMI PMC local time variations are closely coupled to concurrent variations in measurement scattering angle, so that ice phase function effects must be considered when interpreting the observations. Two different phase functions corresponding to bright and faint clouds are examined in this analysis. OMI observations show maximum frequency and albedo values at 8-10 h local time in the Northern Hemisphere, with decreasing amplitude at higher latitudes. Southern Hemisphere values reach a minimum at 18-20 h LT. Larger variations are seen in Northern Hemisphere data. No statistically significant longitudinal dependence was seen.

  7. Simultaneous Spectral and Timing Observations of Accreting Neuron Stars

    NASA Technical Reports Server (NTRS)

    Kaaret, P.; Oliversen, Ronald J. (Technical Monitor)

    2002-01-01

    The goal of this proposal is to perform simultaneous x-ray spectral and millisecond timing observations of accreting neutron stars to further our understanding of their accretion dynamics and in the hope of using these systems as probes of the physics of strong gravitational fields. NAG5-9104 is the successor grant to NAG5-8408. Observations using the Rossi X-Ray Timing Explorer (RXTE) and BeppoSAX were performed of 4U1702-429, 4U1735-44, and Cyg X-2. Unfortunately, only a small fraction of the approved observing time was obtained for the first two targets and the data are of limited scientific value. Data analysis has been completed on the observations of Cyg X-2. We discovered a correlation between the frequency of the horizontal branch oscillations (HBO) and a soft, thermal component of the x-ray spectrum likely associated with emission from the accretion disk. This correlation may place constraints on models of the oscillations. A paper based on these results appeared in the Astrophysical Journal.

  8. Observation Impacts for Longer Forecast Lead-Times

    NASA Astrophysics Data System (ADS)

    Mahajan, R.; Gelaro, R.; Todling, R.

    2013-12-01

    Observation impact on forecasts evaluated using adjoint-based techniques (e.g. Langland and Baker, 2004) are limited by the validity of the assumptions underlying the forecasting model adjoint. Most applications of this approach have focused on deriving observation impacts on short-range forecasts (e.g. 24-hour) in part to stay well within linearization assumptions. The most widely used measure of observation impact relies on the availability of the analysis for verifying the forecasts. As pointed out by Gelaro et al. (2007), and more recently by Todling (2013), this introduces undesirable correlations in the measure that are likely to affect the resulting assessment of the observing system. Stappers and Barkmeijer (2012) introduced a technique that, in principle, allows extending the validity of tangent linear and corresponding adjoint models to longer lead-times, thereby reducing the correlations in the measures used for observation impact assessments. The methodology provides the means to better represent linearized models by making use of Gaussian quadrature relations to handle various underlying non-linear model trajectories. The formulation is exact for particular bi-linear dynamics; it corresponds to an approximation for general-type nonlinearities and must be tested for large atmospheric models. The present work investigates the approach of Stappers and Barkmeijer (2012)in the context of NASA's Goddard Earth Observing System Version 5 (GEOS-5) atmospheric data assimilation system (ADAS). The goal is to calculate observation impacts in the GEOS-5 ADAS for forecast lead-times of at least 48 hours in order to reduce the potential for undesirable correlations that occur at shorter forecast lead times. References [1]Langland, R. H., and N. L. Baker, 2004: Estimation of observation impact using the NRL atmospheric variational data assimilation adjoint system. Tellus, 56A, 189-201. [2] Gelaro, R., Y. Zhu, and R. M. Errico, 2007: Examination of various

  9. Statistical approaches to lifetime measurements with restricted observation times

    NASA Astrophysics Data System (ADS)

    Chen, X. C.; Zeng, Q.; Litvinov, Yu. A.; Tu, X. L.; Walker, P. M.; Wang, M.; Wang, Q.; Yue, K.; Zhang, Y. H.

    2017-09-01

    Two generic methods based on frequentism and Bayesianism are presented in this work aiming to adequately estimate decay lifetimes from measured data, while accounting for restricted observation times in the measurements. All the experimental scenarios that can possibly arise from the observation constraints are treated systematically and formulas are derived. The methods are then tested against the decay data of bare isomeric 44+94mRu, which were measured using isochronous mass spectrometry with a timing detector at the CSRe in Lanzhou, China. Applying both methods in three distinct scenarios yields six different but consistent lifetime estimates. The deduced values are all in good agreement with a prediction based on the neutral-atom value modified to take the absence of internal conversion into account. Potential applications of such methods are discussed.

  10. RXTE Observation of Cygnus X-1: Spectra and Timing

    NASA Technical Reports Server (NTRS)

    Wilms, J.; Dove, J.; Nowak, M.; Vaughan, B. A.

    1997-01-01

    We present preliminary results from the analysis of an R.XTE observation of Cyg X-1 in the hard state. We show that the observed X-ray spectrum can be explained with a model for an accretion disk corona (ADC), in which a hot sphere is situated inside of a cold accretion disk (similar to an advection dominated model). ADC Models with a slab-geometry do not successfully fit the data. In addition to the spectral results we present the observed temporal properties of Cyg X-1, i.e. the coherence-function and the time-lags, and discuss the constraints the. temporal properties imply for the accretion geometry in Cyg X-1.

  11. Astrometric observations of Hevelius and derived values of ΔT (dynamical time - universal time).

    NASA Astrophysics Data System (ADS)

    Wünsch, J.

    About 1500 meridian altitudes of the Sun observed by Johannes Hevelius (1611 - 1687) at Danzig in the years 1652 - 1679 and about 1160 distances of fixed stars from the lunar limb obtained in 1658 - 1679 as well as 48 occultations of stars by the Moon were analyzed with the aim to obtain a value of the time difference ΔT = ET - UT between ephemeris time and universal time for the period of Hevelius' observations. This time difference is a measure of the "clock error" of the rotation of the Earth, caused mainly by secular deceleration due to tidal friction.

  12. Mobile/Real-Time Seafloor Seismic Observation System

    NASA Astrophysics Data System (ADS)

    Sugioka, H.; Kawaguchi, K.; Mikada, H.; Suyehiro, K.

    2001-12-01

    Since 1997, Japan Marine Science and Technology Center (JAMSTEC) started a project to develop submarine cable systems for building a series of geophysical observation network at active seismogenic zones around Japan. These cabled systems are very powerful tool for real-time and long-term geophysical observation. However, it has weakness in mobility compared to a land or a free-fall, pop-up ocean bottom observation systems. We developed an adaptable observation system with a concept to realize both mobile and real-time observations. This system consists of a Branch Multiplexer (B-MUX), a Joint Multiplexer (J-MUX), a fiber cable, a battery pack and a sensor package. The B-MUX branches the main optical-fiber line and allows to install J-MUX at the end of the branched line. The J-MUX is a hub for adaptable observatories, which can be accept up to 4 satellite stations extending up to 10 km distance away. All this setup can be done using a towed vehicle and ROV. No cable ship is required. First of all, a broadband seismometer (3-component Guralp CMG-1T system) was installed off Kushiro-Tokachi, Hokkaido, at a water depth of 2133 m, in July 2001. Real-time seismic data are being successfully acquired at 100 Hz sampling rate. The system has an advantage which the sensor control signals can be transmitted from the land station and are demultiplexed and distributed by the telemetry unit to the each interface through the B-MUX. The battery pack can operate the sensor system for 7.5 months. Several large teleseismic earthquake (M > 6.5) were recorded with high S/N. The prominent microseism peak at 0.2 Hz divides into long- and short-period quiet bands. The longer period band between 0.03 and 0.1 Hz provides a low-noise window for the detection of long-period body waves and higher mode Rayleigh waves propagated from the teleseismic earthquakes. Our mobile observation system provides an opportunity to extend existing seafloor observation network, and that any geo

  13. Assessing observational studies of medical treatments

    PubMed Central

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

    2005-01-01

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

  14. Observed and Expected Mortality in Cohort Studies.

    PubMed

    Richardson, David B; Keil, Alexander P; Cole, Stephen R; MacLehose, Richard F

    2017-03-15

    Epidemiologists often compare the observed number of deaths in a cohort with the expected number of deaths, obtained by multiplying person-time accrued in the cohort by mortality rates for a reference population (ideally, a reference that represents the mortality rate in the cohort in the absence of exposure). However, if exposure is hazardous (or salutary), this calculation will not consistently estimate the number of deaths expected in the absence of exposure because exposure will have affected the distribution of person-time observed in the study cohort. While problems with interpretation of this standard calculation of expected counts were discussed more than 2 decades ago, these discussions had little impact on epidemiologic practice. The logic of counterfactuals may help clarify this topic as we revisit these issues. In this paper, we describe a simple way to consistently estimate the expected number of deaths in such settings, and we illustrate the approach using data from a cohort study of mortality among underground miners. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Interoperable Access to Near Real Time Ocean Observations with the Observing System Monitoring Center

    NASA Astrophysics Data System (ADS)

    O'Brien, K.; Hankin, S.; Mendelssohn, R.; Simons, R.; Smith, B.; Kern, K. J.

    2013-12-01

    The Observing System Monitoring Center (OSMC), a project funded by the National Oceanic and Atmospheric Administration's Climate Observations Division (COD), exists to join the discrete 'networks' of In Situ ocean observing platforms -- ships, surface floats, profiling floats, tide gauges, etc. - into a single, integrated system. The OSMC is addressing this goal through capabilities in three areas focusing on the needs of specific user groups: 1) it provides real time monitoring of the integrated observing system assets to assist management in optimizing the cost-effectiveness of the system for the assessment of climate variables; 2) it makes the stream of real time data coming from the observing system available to scientific end users into an easy-to-use form; and 3) in the future, it will unify the delayed-mode data from platform-focused data assembly centers into a standards- based distributed system that is readily accessible to interested users from the science and education communities. In this presentation, we will be focusing on the efforts of the OSMC to provide interoperable access to the near real time data stream that is available via the Global Telecommunications System (GTS). This is a very rich data source, and includes data from nearly all of the oceanographic platforms that are actively observing. We will discuss how the data is being served out using a number of widely used 'web services' (including OPeNDAP and SOS) and downloadable file formats (KML, csv, xls, netCDF), so that it can be accessed in web browsers and popular desktop analysis tools. We will also be discussing our use of the Environmental Research Division's Data Access Program (ERDDAP), available from NOAA/NMFS, which has allowed us to achieve our goals of serving the near real time data. From an interoperability perspective, it's important to note that access to the this stream of data is not just for humans, but also for machine-to-machine requests. We'll also delve into how we

  16. 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.

  17. 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.

  18. Cluster Observations of Non-Time Continuous Magnetosonic Waves

    NASA Technical Reports Server (NTRS)

    Walker, Simon N.; Demekhov, Andrei G.; Boardsen, Scott A.; Ganushkina, Natalia Y.; Sibeck, David G.; Balikhin, Michael A.

    2016-01-01

    Equatorial magnetosonic waves are normally observed as temporally continuous sets of emissions lasting from minutes to hours. Recent observations, however, have shown that this is not always the case. Using Cluster data, this study identifies two distinct forms of these non temporally continuous use missions. The first, referred to as rising tone emissions, are characterized by the systematic onset of wave activity at increasing proton gyroharmonic frequencies. Sets of harmonic emissions (emission elements)are observed to occur periodically in the region +/- 10 off the geomagnetic equator. The sweep rate of these emissions maximizes at the geomagnetic equator. In addition, the ellipticity and propagation direction also change systematically as Cluster crosses the geomagnetic equator. It is shown that the observed frequency sweep rate is unlikely to result from the sideband instability related to nonlinear trapping of suprathermal protons in the wave field. The second form of emissions is characterized by the simultaneous onset of activity across a range of harmonic frequencies. These waves are observed at irregular intervals. Their occurrence correlates with changes in the spacecraft potential, a measurement that is used as a proxy for electron density. Thus, these waves appear to be trapped within regions of localized enhancement of the electron density.

  19. Cluster Observations of Non-Time Continuous Magnetosonic Waves

    NASA Technical Reports Server (NTRS)

    Walker, Simon N.; Demekhov, Andrei G.; Boardsen, Scott A.; Ganushkina, Natalia Y.; Sibeck, David G.; Balikhin, Michael A.

    2016-01-01

    Equatorial magnetosonic waves are normally observed as temporally continuous sets of emissions lasting from minutes to hours. Recent observations, however, have shown that this is not always the case. Using Cluster data, this study identifies two distinct forms of these non temporally continuous use missions. The first, referred to as rising tone emissions, are characterized by the systematic onset of wave activity at increasing proton gyroharmonic frequencies. Sets of harmonic emissions (emission elements)are observed to occur periodically in the region +/- 10 off the geomagnetic equator. The sweep rate of these emissions maximizes at the geomagnetic equator. In addition, the ellipticity and propagation direction also change systematically as Cluster crosses the geomagnetic equator. It is shown that the observed frequency sweep rate is unlikely to result from the sideband instability related to nonlinear trapping of suprathermal protons in the wave field. The second form of emissions is characterized by the simultaneous onset of activity across a range of harmonic frequencies. These waves are observed at irregular intervals. Their occurrence correlates with changes in the spacecraft potential, a measurement that is used as a proxy for electron density. Thus, these waves appear to be trapped within regions of localized enhancement of the electron density.

  20. Cluster observations of non-time continuous magnetosonic waves

    NASA Astrophysics Data System (ADS)

    Walker, Simon N.; Demekhov, Andrei G.; Boardsen, Scott A.; Ganushkina, Natalia Y.; Sibeck, David G.; Balikhin, Michael A.

    2016-10-01

    Equatorial magnetosonic waves are normally observed as temporally continuous sets of emissions lasting from minutes to hours. Recent observations, however, have shown that this is not always the case. Using Cluster data, this study identifies two distinct forms of these non-temporally continuous emissions. The first, referred to as rising tone emissions, are characterized by the systematic onset of wave activity at increasing proton gyroharmonic frequencies. Sets of harmonic emissions (emission elements) are observed to occur periodically in the region ±10° off the geomagnetic equator. The sweep rate of these emissions maximizes at the geomagnetic equator. In addition, the ellipticity and propagation direction also change systematically as Cluster crosses the geomagnetic equator. It is shown that the observed frequency sweep rate is unlikely to result from the sideband instability related to nonlinear trapping of suprathermal protons in the wave field. The second form of emissions is characterized by the simultaneous onset of activity across a range of harmonic frequencies. These waves are observed at irregular intervals. Their occurrence correlates with changes in the spacecraft potential, a measurement that is used as a proxy for electron density. Thus, these waves appear to be trapped within regions of localized enhancement of the electron density.

  1. Remote Observations of Ion Temperatures in the Quiet Time Magnetosphere

    NASA Technical Reports Server (NTRS)

    Keesee, A. M.; Buzulukova, N.; Goldstein, J.; McComas, D. J.; Scime, E. E.; Spence, H.; Fok, M. C.; Tallaksen, K.

    2011-01-01

    Ion temperature analysis of the first energetic neutral atom images of the quiet -time, extended magnetosphere provides evidence of multiple regions of ion heating. This study confirms the existence of a dawn -dusk asymmetry in ion temperature predicted for quiescent magnetospheric conditions by Spence and Kivelson (1993) and demonstrates that it is an inherent magnetospheric feature.

  2. Causal Structure Learning over Time: Observations and Interventions

    ERIC Educational Resources Information Center

    Rottman, Benjamin M.; Keil, Frank C.

    2012-01-01

    Seven studies examined how people learn causal relationships in scenarios when the variables are temporally dependent--the states of variables are stable over time. When people intervene on X, and Y subsequently changes state compared to before the intervention, people infer that X influences Y. This strategy allows people to learn causal…

  3. Remote Observations of Ion Temperatures in the Quiet Time Magnetosphere

    NASA Technical Reports Server (NTRS)

    Keesee, A. M.; Buzulukova, N.; Goldstein, J.; McComas, D. J.; Scime, E. E.; Spence, H.; Fok, M. C.; Tallaksen, K.

    2011-01-01

    Ion temperature analysis of the first energetic neutral atom images of the quiet -time, extended magnetosphere provides evidence of multiple regions of ion heating. This study confirms the existence of a dawn -dusk asymmetry in ion temperature predicted for quiescent magnetospheric conditions by Spence and Kivelson (1993) and demonstrates that it is an inherent magnetospheric feature.

  4. Observing Anthropometric and Acanthosis Nigrican Changes among Children Over Time

    ERIC Educational Resources Information Center

    Law, Jennifer; Northrup, Karen; Wittberg, Richard; Lilly, Christa; Cottrell, Lesley

    2013-01-01

    This study assessed the anthropometrics and acanthosis nigricans (AN) in a sample of 7,337 children at two assessments. Four groups of children were identified based on the presence of AN at both time points: those who never had the marker, those who gained the marker, those who lost the marker, and those who maintained the marker. Group…

  5. Observing Anthropometric and Acanthosis Nigrican Changes among Children Over Time

    ERIC Educational Resources Information Center

    Law, Jennifer; Northrup, Karen; Wittberg, Richard; Lilly, Christa; Cottrell, Lesley

    2013-01-01

    This study assessed the anthropometrics and acanthosis nigricans (AN) in a sample of 7,337 children at two assessments. Four groups of children were identified based on the presence of AN at both time points: those who never had the marker, those who gained the marker, those who lost the marker, and those who maintained the marker. Group…

  6. Causal Structure Learning over Time: Observations and Interventions

    ERIC Educational Resources Information Center

    Rottman, Benjamin M.; Keil, Frank C.

    2012-01-01

    Seven studies examined how people learn causal relationships in scenarios when the variables are temporally dependent--the states of variables are stable over time. When people intervene on X, and Y subsequently changes state compared to before the intervention, people infer that X influences Y. This strategy allows people to learn causal…

  7. Time-of-flight observation of electron swarm in methane

    SciTech Connect

    Hasegawa, H.; Date, H.; Yoshida, K.; Shimozuma, M.

    2009-06-01

    This paper reports on the evolution of an isolated electron swarm, which is experimentally observed as spatial distributions at every moment. This observation is assumed to directly correspond to the conventional time-of-flight theory. We have measured the spatial distribution of electrons using a double-shutter technique in the drift tube, where a shutter electrode to collect electrons can be slid along the field (E/N) direction in order to capture a relative electron number at a certain range of location. As a typical parameter defined by this spatial distribution, the center-of-mass drift velocity (W{sub r}) is determined for methane gas. The result is compared with the mean-arrival-time drift velocity (W{sub m}) defined from the arriving electron number at fixed positions. We have also performed a theoretical analysis in which a Fourier transformed Boltzmann equation is solved to deduce both of the drift velocities from a dispersion relationship. The difference between W{sub r} and W{sub m} at high E/Ns (above 200 Td) is clearly ascertained in the experimental and theoretical investigations, which is attributable to the occurrence of ionization events.

  8. Challenges to Deriving Climate Time Series From Satellite Observations

    NASA Astrophysics Data System (ADS)

    Wentz, F. J.; Mears, C. A.

    2005-12-01

    Satellites have been observing the Earth's weather and climate since the launch of TIROS-1 in 1960. As satellite and sensor technology advanced over the next two decades, the accuracy of the satellite observations improved to the point of being useful for climate monitoring. The launch of the first Microwave Sounding Unit (MSU) in October 1978 and the first Special Sensor Microwave Imager (SSM/I) in June 1987 mark the beginning of research-quality time series for several important climate state variables, including tropospheric temperature and water vapor, cloud and rain water, and ocean surface winds. In this talk, we will illustrate the many obstacles that must be overcome to convert raw satellite measurements into climate data records. Probably the most pivotal issue is sensor calibration. Although an on-board self-calibrating apparatus is part of each satellite sensor, the accuracy of the calibration system is limited and in some cases unexpected calibration problems occurred on-orbit. The lack of exact calibration leads to a second problem: merging sensors flying on many different satellites into one consistent decadal time series. Also drifts in the satellites' orbits, both in altitude and local time of day, must be carefully taken into account else spurious signals will enter the time series. In addition to these technical difficulties, programmatic problems present a different set of hurdles that must be overcome. The maintenance of a long-term climate record may necessitate sustaining a long-term research activity requiring continuity in both expert staffing and funding. The alternative of computing climate records in an operational rather than research environment creates a new set of problems. As the satellite sensor technology continues to advance into the next decade, new challenges will arise. The new sensors will have different channel sets, viewing geometries, and orbital characteristics. Their complexity will be an order of magnitude greater than

  9. Observational constraints on late-time {lambda}(t) cosmology

    SciTech Connect

    Carneiro, S.; Pigozzo, C.; Dantas, M. A.; Alcaniz, J. S.

    2008-04-15

    The cosmological constant {lambda}, i.e., the energy density stored in the true vacuum state of all existing fields in the Universe, is the simplest and the most natural possibility to describe the current cosmic acceleration. However, despite its observational successes, such a possibility exacerbates the well-known {lambda} problem, requiring a natural explanation for its small, but nonzero, value. In this paper we study cosmological consequences of a scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter, {lambda}{proportional_to}H. We test the viability of this scenario and study a possible way to distinguish it from the current standard cosmological model by using recent observations of type Ia supernova (Supernova Legacy Survey Collaboration), measurements of the baryonic acoustic oscillation from the Sloan Digital Sky Survey, and the position of the first peak of the cosmic microwave background angular spectrum from the three-year Wilkinson Microwave Anisotropy Probe.

  10. Promoting discovery and access to real time observations produced by regional coastal ocean observing systems

    NASA Astrophysics Data System (ADS)

    Anderson, D. M.; Snowden, D. P.; Bochenek, R.; Bickel, A.

    2015-12-01

    In the U.S. coastal waters, a network of eleven regional coastal ocean observing systems support real-time coastal and ocean observing. The platforms supported and variables acquired are diverse, ranging from current sensing high frequency (HF) radar to autonomous gliders. The system incorporates data produced by other networks and experimental systems, further increasing the breadth of the collection. Strategies promoted by the U.S. Integrated Ocean Observing System (IOOS) ensure these data are not lost at sea. Every data set deserves a description. ISO and FGDC compliant metadata enables catalog interoperability and record-sharing. Extensive use of netCDF with the Climate and Forecast convention (identifying both metadata and a structured format) is shown to be a powerful strategy to promote discovery, interoperability, and re-use of the data. To integrate specialized data which are often obscure, quality control protocols are being developed to homogenize the QC and make these data more integrate-able. Data Assembly Centers have been established to integrate some specialized streams including gliders, animal telemetry, and HF radar. Subsets of data that are ingested into the National Data Buoy Center are also routed to the Global Telecommunications System (GTS) of the World Meteorological Organization to assure wide international distribution. From the GTS, data are assimilated into now-cast and forecast models, fed to other observing systems, and used to support observation-based decision making such as forecasts, warnings, and alerts. For a few years apps were a popular way to deliver these real-time data streams to phones and tablets. Responsive and adaptive web sites are an emerging flexible strategy to provide access to the regional coastal ocean observations.

  11. Real-Time Observation of Cell and Carbon Nanotube Interactions

    NASA Astrophysics Data System (ADS)

    Chen, Michelle; Broman, Melanie; Mathews, Claire; McPherson, Eric

    2014-03-01

    Carbon nanotubes have been widely researched for disease diagnosis and drug delivery applications. However, its impact on biological systems is yet to be sufficiently understood. We studied optical imaging of Chinese hamster ovarian (CHO) cells exposed to various carbon nanotubes concentrations at various time points. The cell stress due to carbon nanotubes exposure is accessed via morphological changes of the CHO cells. Data showed that cell death increases with increasing carbon nanotube concentration and time exposure. To continuously view such changes of any one individual cell, we constructed an optically transparent miniaturized incubator that fits on a microscope stage. This specific incubator is able to maintain desirable temperature, humidity, and CO2 concentration to allow proper cell growth. Such incubator can be used to track real-time interactions of any cells and nanomaterials for future data collection.

  12. Exploiting Dragon Envisat Times Series and Other Earth Observation Data

    NASA Astrophysics Data System (ADS)

    Marie, Tiphanie; Lai, Xijun; Huber, Claire; Chen, Xiaoling; Uribe, Carlos; Huang, Shifeng; Lafaye, Murielle; Yesou, Herve

    2010-10-01

    Earth Observation data were used for mapping potential Schistosomiasis japonica distribution, within Poyang Lake (Jiangxi Province, PR China). In the first of two steps, areas suitable for the development of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum, were derived from submersion time parameters and vegetation community indicators. Y early maps from 2003 to 2008 indicate five principally potential endemic areas: Poyang Lake National Nature Reserve, Dalianzi Hu, Gan Delta, Po Jiang and Xi He. Monthly maps showing the annual dynamic of potential O. hupensis presence areas were obtained from December 2005 to December 2008. In a second step human potential transmission risk was handled through the mapping of settlements and the identification of some human activities. The urban areas and settlements were mapped all around the lake and fishing net locations in the central part of Poyang Lake were identified. Finally, data crossing of the different parameters highlight the potential risk of transmission in most of the fishing nets areas.

  13. Observation of Broadband Time-Dependent Rabi Shifting in Microplasmas

    SciTech Connect

    Compton, Ryan; Filin, Alex; Romanov, Dmitri A.; Levis, Robert J.

    2009-11-13

    Coherent broadband radiation in the form of Rabi sidebands is observed when a ps probe laser propagates through a weakly ionized, electronically excited microplasma generated in the focus of an intense pump beam. The sidebands arise from the interaction of the probe beam with pairs of excited states of a constituent neutral atom via the probe-induced Rabi oscillation. Sideband shifting of >90 meV from the probe carrier frequency results in an effective bandwidth of 200 meV. The sidebands are controlled by the intensity and temporal profile of the probe pulse; with amplitude and shift in agreement with the predictions of a time-dependent generalized Rabi cycling model.

  14. Real-time observation of liposome bursting induced by acetonitrile.

    PubMed

    Yoshida, Kazunari; Horii, Keitaro; Fujii, Yasuhiro; Nishio, Izumi

    2014-10-06

    We show the bursting process of dioleoylphosphatidylcholine (DOPC) liposomes in response to the addition of acetonitrile, a small toxic molecule widely used in the fields of chemistry and industry. The percentage of destroyed liposomes is reduced upon decreasing the acetonitrile fraction in the aqueous solution and vesicle bursting is not observed at volume ratios of 4:6 and below. This indicates that a high fraction of acetonitrile causes the bursting of liposomes, and it is proposed that this occurs through insertion of the molecules into outer leaflet of the lipid bilayer. The elapsed time between initial addition of acetonitrile and liposome bursting at each vesicle is also measured and demonstrated to be dependent on the volume fraction of acetonitrile and the vesicle size.

  15. Radar and satellite observations of the storm time cleft

    SciTech Connect

    Yeh, H.C.; Foster, J.C.; Holt, J.M.; Redus, R.H.; Rich, F.J.

    1990-08-01

    During the magnetic storm of February 8-9, 1986, the region of strong ion convection in the vicinity of the dayside cusp expanded equatorward into the field of view of the Millstone Hill radar at lower mid-latitudes. High-speed (>1.5 km/s) poleward ion flows were found at latitudes as low as 60 deg invariant latitude, at least 10 deg lower than the typical cleft/cusp position for moderately disturbed (Kp>4) magnetospheric conditions. The ion velocity pattern responded promptly to changes in the interplanetary magnetic field By direction. The large-scale two-dimensional convection pattern across the dayside was well resolved using radar azimuth scan data at Millstone Hill, thus enabling us to place the fine-scale radar/satellite observations of the storm time cusp and cleft in the context of the large-scale pattern. We present a detailed comparison of radar and DMSP F7 satellite observations in the prenoon sector during a period of Kp > 7, to examine the low-altitude signatures of various plasma regions in the vicinity of the cusp. The combination of particle precipitation, magnetic field perturbation, radar measurements of ion heating, and convection consistently suggests the unusual low-latitude position of cusp at 65 invariant latitude.

  16. Simultaneous Spectral and Timing Observations of Accreting Neuron Stars

    NASA Technical Reports Server (NTRS)

    Kaaret, P.; West, Donald K. (Technical Monitor)

    2001-01-01

    The goal of this proposal was to perform simultaneous x-ray spectral and millisecond timing observations of accreting neutron stars to further our understanding of their accretion dynamics and in the hope of using these systems as probes of the physics of strong gravitational fields. Observations of the neutron star binaries 4U0614+091, 4U1728-34, 4U1820-30, and Cyg X-2 were carried out with RXTE and BeppoSAX, ASCA, and Chandra (not all simultaneously). In addition, archival data were analyzed for 4U0614+091 and 4U1820-30. This investigation led to publication of three papers in peer-reviewed journals. These are listed below. In addition, the results were presented at several meetings including the two poster presentations listed below. Dr. Santina Piraino visited SAO for 4 months during 2000 to collaborate on analysis of the data from NAG5-8408 and NAG5-9104.

  17. 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…

  18. 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…

  19. Local Time Dependence of Jovian Radio Emissions Observed by Galileo

    NASA Technical Reports Server (NTRS)

    Menietti, J. D.; Gurnett, D. A.; Kurth, W. S.; Groene, J. B.

    1999-01-01

    Galileo has been in orbit around Jupiter since December 1995. All the orbits are equatorial and elliptical, with apogees between 60 R(sub J) - 142 R(sub J) and perigees from 8 - 12 R(sub J). Since orbit injection, the plasma wave instrument (PWS) has been collecting data over specific intervals of each of the orbits at all local times and a range of different radial distances. We present the results of a survey of the data for the frequency range 300 kHz to 5.6 MHz, which includes the hectometric (HOM) and low-frequency decametric (DAM) emissions. The results indicate that both the HOM and DAM emission are more intense and occur more frequently in the midnight sector of Jupiter. This is in analogy to Earth and consistent with a magnetic substorm source for a portion of the radio emissions in this frequency range. Another peak in the power levels is observed on the Jovian dayside in the local time range 11 hrs < LT < 12 hrs. This peak does not have a terrestrial counterpart. We speculate that this dayside peak may be a result of sampling near perigee, but we cannot rule out the possibility that this is not the case.

  20. Time process study with UML.

    PubMed

    Shiki, N; Ohno, Y; Fujii, A; Murata, T; Matsumura, Y

    2009-01-01

    We propose a new business-process analysis approach, Time Process Study (TPS), which comprises process analysis and time and motion studies (TMS). TPS offsets weaknesses of TMS; the cost of field studies and the difficulties in applying them to tasks whose time span differs from those of usual tasks. In TPS, the job procedures are first displayed using a unified modeling language (UML). Next, time and manpower for each procedure are studied through interviews and TMS, and the information is appended to the UML diagram. We applied TPS in the case of a hospital-based cancer registry (HCR) of a university hospital to clarify the work procedure and the time required, and investigated TPS's availability. Meetings for the study were held once a month from July to September in 2008, and one inquirer committed a total of eight hours to the hospital survey. TPS revealed that HCR consisted of three tasks and 14 functions. The registration required 123 hours/month/person, the quality control required 6.5 hours/ 6 months/person and filing data into the population-based cancer registry required 0.5 hours/6 months/person. Of the total tasks involved in registration, 116.5 hours/month/person were undertaken by a registration worker, which shows the necessity of employing one full-time staff. With TPS, it is straightforward to share the concept among the study-team because the job procedure is first displayed using UML. Therefore, it requires a few workload to conduct TMS and interview. The obtained results were adopted for the review of staff assignment of HCR by Japanese government.

  1. Real-time molecular scale observation of crystal formation

    NASA Astrophysics Data System (ADS)

    Schreiber, Roy E.; Houben, Lothar; Wolf, Sharon G.; Leitus, Gregory; Lang, Zhong-Ling; Carbó, Jorge J.; Poblet, Josep M.; Neumann, Ronny

    2017-04-01

    How molecules in solution form crystal nuclei, which then grow into large crystals, is a poorly understood phenomenon. The classical mechanism of homogeneous crystal nucleation proceeds via the spontaneous random aggregation of species from liquid or solution. However, a non-classical mechanism suggests the formation of an amorphous dense phase that reorders to form stable crystal nuclei. So far it has remained an experimental challenge to observe the formation of crystal nuclei from five to thirty molecules. Here, using polyoxometallates, we show that the formation of small crystal nuclei is observable by cryogenic transmission electron microscopy. We observe both classical and non-classical nucleation processes, depending on the identity of the cation present. The experiments verify theoretical studies that suggest non-classical nucleation is the lower of the two energy pathways. The arrangement in just a seven-molecule proto-crystal matches the order found by X-ray diffraction of a single bulk crystal, which demonstrates that the same structure was formed in each case.

  2. Real-time molecular scale observation of crystal formation.

    PubMed

    Schreiber, Roy E; Houben, Lothar; Wolf, Sharon G; Leitus, Gregory; Lang, Zhong-Ling; Carbó, Jorge J; Poblet, Josep M; Neumann, Ronny

    2017-04-01

    How molecules in solution form crystal nuclei, which then grow into large crystals, is a poorly understood phenomenon. The classical mechanism of homogeneous crystal nucleation proceeds via the spontaneous random aggregation of species from liquid or solution. However, a non-classical mechanism suggests the formation of an amorphous dense phase that reorders to form stable crystal nuclei. So far it has remained an experimental challenge to observe the formation of crystal nuclei from five to thirty molecules. Here, using polyoxometallates, we show that the formation of small crystal nuclei is observable by cryogenic transmission electron microscopy. We observe both classical and non-classical nucleation processes, depending on the identity of the cation present. The experiments verify theoretical studies that suggest non-classical nucleation is the lower of the two energy pathways. The arrangement in just a seven-molecule proto-crystal matches the order found by X-ray diffraction of a single bulk crystal, which demonstrates that the same structure was formed in each case.

  3. Optimizing Spectral Resolution and Observation Time for Measurements of Habitability

    NASA Astrophysics Data System (ADS)

    Khalfa, N.; Meadows, V. S.; Domagal-Goldman, S. D.

    2009-12-01

    The Terrestrial Planet Finder (TPF) is a NASA mission concept that will attempt to characterize and search for habitability and life on extrasolar planets. While detection of a planet in the habitable zone increases the probability that the planet is habitable, planetary characterization will be required to confirm habitability and thereby test predictions of the position of the habitable zone. The TPF-I mission will accomplish this with an interferometer, allowing the detection of Earth-mass planets around stars up to 15 pc away and production of mid-infrared spectra from those planets. The focus on the mid-infrared region of the spectrum (7-20 mm) is beneficial because this is where energy from Earth-like planets is strongest relative to the flux from their parent stars. To discover if such planets are habitable we need to know not only what to look for - biosignatures and indicators of habitability - but also how to look. In other words, we must determine the trade-off in telescope properties that will provide the best science return. Extensive models have been made of Earth-like planets to describe many planetary properties, including atmospheric chemistry and surface temperature. Those properties may be derived for extrasolar planets using these models if spectra are obtained for the target planet. When modeling a planet, we can calculate a very high-resolution spectrum that can show the detailed absorption features of gases such as CO2, H2O, and O3. However, the telescope resolution will necessarily be limited by low photon fluxes from the distant targets. Alternatively, the telescope could spend more time taking in photons from each target planet. A balance may have to be struck between the numbers of targets observed and the quality of the data obtained for each target. We will present a number of simulations of TPF instrument measurements of terrestrial spectra that parametrize spectral resolution and observation time. The relative errors of these various

  4. Effects of Atorvastatin Dose and Concomitant Use of Angiotensin-Converting Enzyme Inhibitors on Renal Function Changes over Time in Patients with Stable Coronary Artery Disease: A Prospective Observational Study.

    PubMed

    Wieczorek-Surdacka, Ewa; Świerszcz, Jolanta; Surdacki, Andrzej

    2016-02-02

    Angiotensin-converting enzyme inhibitors (ACEI) and statins are widely used in patients with coronary artery disease (CAD). Our aim was to compare changes in glomerular filtration rate (GFR) over time in subjects with stable CAD according to atorvastatin dose and concomitant use of ACEI. We studied 78 men with stable CAD referred for an elective coronary angiography who attained the then-current guideline-recommended target level of low-density lipoproteins (LDL) cholesterol below 2.5 mmol/L in a routine fasting lipid panel on admission and were receiving atorvastatin at a daily dose of 10-40 mg for ≥3 months preceding the index hospitalization. Due to an observational study design, atorvastatin dosage was not intentionally modified for other reasons. GFR was estimated during index hospitalization and at about one year after discharge from our center. Irrespective of ACEI use, a prevention of kidney function loss was observed only in those treated with the highest atorvastatin dose. In 38 subjects on ACEI, both of the higher atorvastatin doses were associated with increasing beneficial effects on GFR changes (mean ± SEM: -4.2 ± 2.4, 1.1 ± 1.6, 5.2 ± 2.4 mL/min per 1.73 m² for the 10-mg, 20-mg and 40-mg atorvastatin group, respectively, p = 0.02 by ANOVA; Spearman's rho = 0.50, p = 0.001 for trend). In sharp contrast, in 40 patients without ACEI, no significant trend effect was observed across increasing atorvastatin dosage (respective GFR changes: -1.3 ± 1.0, -4.7 ± 2.1, 4.8 ± 3.6 mL/min per 1.73 m², p = 0.02 by ANOVA; rho = 0.08, p = 0.6 for trend). The results were substantially unchanged after adjustment for baseline GFR or time-dependent variations of LDL cholesterol. Thus, concomitant ACEI use appears to facilitate the ability of increasing atorvastatin doses to beneficially modulate time-dependent changes in GFR in men with stable CAD.

  5. 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.

  6. First time-dependent study of H{sub 2} and H{sub 3}{sup +} ortho-para chemistry in the diffuse interstellar medium: Observations meet theoretical predictions

    SciTech Connect

    Albertsson, T.; Semenov, D.; Henning, Th.; Indriolo, N.; Kreckel, H.; Crabtree, K. N.

    2014-05-20

    The chemistry in the diffuse interstellar medium (ISM) initiates the gradual increase of molecular complexity during the life cycle of matter. A key molecule that enables build-up of new molecular bonds and new molecules via proton donation is H{sub 3}{sup +}. Its evolution is tightly related to molecular hydrogen and thought to be well understood. However, recent observations of ortho and para lines of H{sub 2} and H{sub 3}{sup +} in the diffuse ISM showed a puzzling discrepancy in nuclear spin excitation temperatures and populations between these two key species. H{sub 3}{sup +}, unlike H{sub 2}, seems to be out of thermal equilibrium, contrary to the predictions of modern astrochemical models. We conduct the first time-dependent modeling of the para-fractions of H{sub 2} and H{sub 3}{sup +} in the diffuse ISM and compare our results to a set of line-of-sight observations, including new measurements presented in this study. We isolate a set of key reactions for H{sub 3}{sup +} and find that the destruction of the lowest rotational states of H{sub 3}{sup +} by dissociative recombination largely controls its ortho/para ratio. A plausible agreement with observations cannot be achieved unless a ratio larger than 1:5 for the destruction of (1, 1)- and (1, 0)-states of H{sub 3}{sup +} is assumed. Additionally, an increased cosmic-ray ionization rate to 10{sup –15} s{sup –1} further improves the fit whereas variations of other individual physical parameters, such as density and chemical age, have only a minor effect on the predicted ortho/para ratios. Thus, our study calls for new laboratory measurements of the dissociative recombination rate and branching ratio of the key ion H{sub 3}{sup +} under interstellar conditions.

  7. Near Real Time website for IASI observations of atmospheric anomalies

    NASA Astrophysics Data System (ADS)

    Hayer, Catherine; Grainger, Don; Marsh, Kevin; Carboni, Elisa; Ventress, Lucy; Smith, Andrew

    2014-05-01

    Rapid analysis of satellite observations of the state of the atmosphere and the contaminant levels within it can be used for pollution monitoring, forest fire detection and volcanic activity monitoring. There are numerous operational satellite instruments for which this is possible. The IASI instruments, currently flying on board the MetOp-A and MetOp-B satellite platforms, are used to produce Near Real Time (NRT) data using analysis algorithms developed by Oxford University. The data is then displayed on a website within 3 hours of measurement. This allows for the semi-continuous monitoring of the state of the atmosphere over most of the globe, both in daylight and at night. Global coverage is achieved 4 times per day, which is a significant advantage over most of the alternatives, either geostationary, giving limited spatial coverage, or UV instruments which are only able to observe during the daylight side of the orbit. The website includes flags for atmospheric contaminants detectable by IASI, including dust, biomass burning-derived species and volcanic ash and SO2. In the near future, the website will be developed to also include a quantitative estimate of the mass loading of SO2 contained within any volcanic cloud. Emissions of volcanic products, such as ash and SO2, are useful indicators of a change in the activity level of a volcano. Since many volcanoes are only monitored by remote sensing methods, such as satellite instruments, this can be the only such indicator available. These emissions are also dangerous to passing aircraft, causing damage to external surfaces of the plane and to the engines, sometimes leading to failure. Evacuation of regions surrounding volcanoes, and cessation or diversion of air traffic around actively erupting volcanoes is costly and highly disruptive but is sometimes required. Up to date information is of critical importance as to when to make these sensitive decisions. An archive of data will be available to allow for easy

  8. United States Forest Disturbance Trends Observed Using Landsat Time Series

    NASA Technical Reports Server (NTRS)

    Masek, Jeffrey G.; Goward, Samuel N.; Kennedy, Robert E.; Cohen, Warren B.; Moisen, Gretchen G.; Schleeweis, Karen; Huang, Chengquan

    2013-01-01

    Disturbance events strongly affect the composition, structure, and function of forest ecosystems; however, existing U.S. land management inventories were not designed to monitor disturbance. To begin addressing this gap, the North American Forest Dynamics (NAFD) project has examined a geographic sample of 50 Landsat satellite image time series to assess trends in forest disturbance across the conterminous United States for 1985-2005. The geographic sample design used a probability-based scheme to encompass major forest types and maximize geographic dispersion. For each sample location disturbance was identified in the Landsat series using the Vegetation Change Tracker (VCT) algorithm. The NAFD analysis indicates that, on average, 2.77 Mha/yr of forests were disturbed annually, representing 1.09%/yr of US forestland. These satellite-based national disturbance rates estimates tend to be lower than those derived from land management inventories, reflecting both methodological and definitional differences. In particular the VCT approach used with a biennial time step has limited sensitivity to low-intensity disturbances. Unlike prior satellite studies, our biennial forest disturbance rates vary by nearly a factor of two between high and low years. High western US disturbance rates were associated with active fire years and insect activity, while variability in the east is more strongly related to harvest rates in managed forests. We note that generating a geographic sample based on representing forest type and variability may be problematic since the spatial pattern of disturbance does not necessarily correlate with forest type. We also find that the prevalence of diffuse, non-stand clearing disturbance in US forests makes the application of a biennial geographic sample problematic. Future satellite-based studies of disturbance at regional and national scales should focus on wall-to-wall analyses with annual time step for improved accuracy.

  9. Optimized preoperative fasting times decrease ketone body concentration and stabilize mean arterial blood pressure during induction of anesthesia in children younger than 36 months: a prospective observational cohort study.

    PubMed

    Dennhardt, Nils; Beck, Christiane; Huber, Dirk; Sander, Bjoern; Boehne, Martin; Boethig, Dietmar; Leffler, Andreas; Sümpelmann, Robert

    2016-08-01

    In pediatric anesthesia, preoperative fasting guidelines are still often exceeded. The objective of this noninterventional clinical observational cohort study was to evaluate the effect of an optimized preoperative fasting management (OPT) on glucose concentration, ketone bodies, acid-base balance, and change in mean arterial blood pressure (MAP) during induction of anesthesia in children. Children aged 0-36 months scheduled for elective surgery with OPT (n = 50) were compared with peers studied before optimizing preoperative fasting time (OLD) (n = 50) who were matched for weight, age, and height. In children with OPT (n = 50), mean fasting time (6.0 ± 1.9 h vs 8.5 ± 3.5 h, P < 0.001), deviation from guideline (ΔGL) (1.2 ± 1.4 h vs 3.7 ± 3.1 h, P < 0.001, ΔGL>2 h 8% vs 70%), ketone bodies (0.2 ± 0.2 mmol·l(-1) vs 0.6 ± 0.6 mmol·l(-1) , P < 0.001), and incidence of hypotension (MAP <40 mmHg, 0 vs 5, P = 0.022) were statistically significantly lower and MAP after induction was statistically significantly higher (55.2 ± 9.5 mmHg vs 50.3 ± 9.8 mmHg, P = 0.015) as compared to children in the OLD (n = 50) group. Glucose, lactate, bicarbonate, base excess, and anion gap did not significantly differ. Optimized fasting times improve the metabolic and hemodynamic condition during induction of anesthesia in children younger than 36 months of age. © 2016 John Wiley & Sons Ltd.

  10. Funding Full-Time Study through Part-Time Work

    ERIC Educational Resources Information Center

    Richardson, Mark; Evans, Carl; Gbadamosi, Gbolahan

    2009-01-01

    Full-time students engaged in part-time studies have been a subject of increasing academic attention. This study extends work in this area by examining: the extent to which full-time undergraduate students undertake part-time employment, the reasons for working whilst studying full-time and the extent to which students relate their part-time…

  11. Study of the character of the time dependence of the ratio of signals in the IR and visible channels of a radiometric apparatus when fragments of space junk are observed

    NASA Astrophysics Data System (ADS)

    Pavlov, N. I.; Él'Ts, E. É.

    2006-01-01

    A more accurate expression is derived for determining the specific load of fragments of space junk via the time dependence of the ratio of signals in the IR and visible channels of on-board radiometric observation apparatus. Results are presented of a calculation of the time behavior of this ratio when aluminum and plastic debris is observed on near-earth orbits. The cases considered here involve constant heating of the debris by solar radiation and the variation of this heating according to a harmonic law because the debris rotates around its center of mass.

  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. Toward storm-time ionosphere forecast using GNSS observations

    NASA Astrophysics Data System (ADS)

    Lin, Charles; Chen, Chia-Hung; Liu, Tiger J. Y.; Chen, Wei-Han

    2016-04-01

    Previous theoretical simulations of the mid- and low-latitude ionospheric responses to space weather events have indicated general features of electron density disturbances. The magnetic storm produced penetration electric field and neutral wind disturbances lead to formation of various storm-time ionospheric electron density structures, such as super plasma fountain, equatorial electron density trough and F3 layer, as well as long-lasting global ionosphere suppression. We attempt to model these storm-related ionospheric electron density structures using the global assimilative ionospheric model that assimilates electron densities taken from FORMOSAT-3/COSMIC and TEC from ground-based GNSS receivers. Using the ensemble Kalman filter with consideration of ion densities, electric potential, thermospheric neutral wind and compositions as update variables, we study the performance and forecast capability of the assimilative model. The assimilative model could be utilized for ionosphere forecast in near future.

  14. 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...

  15. Observing Protein & Energy Nutrition (OPEN) Study

    Cancer.gov

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

  16. 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...

  17. 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".

  18. Why Rudolph's nose is red: observational study.

    PubMed

    Ince, Can; van Kuijen, Anne-Marije; Milstein, Dan M J; Yürük, Koray; Folkow, Lars P; Fokkens, Wytske J; Blix, Arnoldus S

    2012-12-14

    To characterise the functional morphology of the nasal microcirculation in humans in comparison with reindeer as a means of testing the hypothesis that the luminous red nose of Rudolph, one of the most well known reindeer pulling Santa Claus's sleigh, is due to the presence of a highly dense and rich nasal microcirculation. Observational study. Tromsø, Norway (near the North Pole), and Amsterdam, the Netherlands. Five healthy human volunteers, two adult reindeer, and a patient with grade 3 nasal polyposis. Architecture of the microvasculature of the nasal septal mucosa and head of the inferior turbinates, kinetics of red blood cells, and real time reactivity of the microcirculation to topical medicines. Similarities between human and reindeer nasal microcirculation were uncovered. Hairpin-like capillaries in the reindeers' nasal septal mucosa were rich in red blood cells, with a perfused vessel density of 20 (SD 0.7) mm/mm(2). Scattered crypt or gland-like structures surrounded by capillaries containing flowing red blood cells were found in human and reindeer noses. In a healthy volunteer, nasal microvascular reactivity was demonstrated by the application of a local anaesthetic with vasoconstrictor activity, which resulted in direct cessation of capillary blood flow. Abnormal microvasculature was observed in the patient with nasal polyposis. The nasal microcirculation of reindeer is richly vascularised, with a vascular density 25% higher than that in humans. These results highlight the intrinsic physiological properties of Rudolph's legendary luminous red nose, which help to protect it from freezing during sleigh rides and to regulate the temperature of the reindeer's brain, factors essential for flying reindeer pulling Santa Claus's sleigh under extreme temperatures.

  19. TIME after TIMED - A perspective on Thermosphere-Ionosphere Mesosphere science and future observational needs after the TIMED mission epoch

    NASA Astrophysics Data System (ADS)

    Mlynczak, M. G.; Russell, J. M., III; Hunt, L. A.; Christensen, A. B.; Paxton, L. J.; Woods, T. N.; Niciejewski, R.; Yee, J. H.

    2016-12-01

    The past 40 years have been a true golden age for space-based observations of the Earth's middle atmosphere (stratosphere to thermosphere). Numerous instruments and missions have been developed and flown to explore the thermal structure, chemical composition, and energy budget of the middle atmosphere. A primary motivation for these observations was the need to understand the photochemistry of stratospheric ozone and its potential depletion by anthropogenic means. As technology evolved, observations were extended higher and higher, into regions previously unobserved from space by optical remote sensing techniques. In the 1990's, NASA initiated the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamcis (TIMED) mission to explore one of the last frontiers of the atmosphere - the region between 60 and 180 km - then referred to as "the ignorosphere." Today, we have 15 years of detailed observations from this remarkable satellite and its 4 instruments, and are recognizing rapid climate change that is occurring above 60 km. The upcoming ICON and GOLD missions will afford new opportunities for scientific discovery by combining data from all three missions. However, it has become clear that continued observations beyond TIMED are required to understand the upper atmosphere as a system that is fully coupled from the edge of Space to the surface of the Earth. In this talk we will review the current status of knowledge of the basic state properties of the thermosphere-ionosphere-mesosphere (TIME) system and will discuss future observations that are required to obtain a comprehensive understanding of the entire TIME system, especially the effects of long term change that are already underway.

  20. Observational and Modeling Study of Mesopheric Bores

    NASA Astrophysics Data System (ADS)

    Loughmiller, P.; Kelley, M.; Hickey, M.

    In our studies of the dynamics of the upper atmosphere, some of the most intriguing mesospheric phenomena we observe high over the Hawaiian night skies are internal bores. These events affecting chemiluminescence are documented in monochromatic airglow images taken by high performance all-sky CCD imaging systems operating at the Maui Space Surveillance Site on top of Haleakala Crater. Data is collected as part of the ongoing, collaborative Maui - Mesosphere and Lower Thermosphere (MALT) campaign, jointly sponsored by the National Science Foundation and the Air Force Office of Scientific Research. Bolstered by the Maui-MALT dataset, several theories now exist for mesospheric bores, agreeing in principle that they are likely nonlinear structures spawned by gravity waves and propagating within ducted waveguide regions, such as thermal inversion layers. A new investigation will model optical emissions using a robust, time-dependent, chemical dynamics model to explore the airglow response to ducted gravity waves and, in turn, the geographical and vertical coupling relationships which may exist.

  1. Real-time observation of epitaxial graphene domain reorientation

    SciTech Connect

    Thuermer, Konrad; Foster, Michael E.; Bartelt, Norman Charles; Rogge, Paul C.; McCarty, Kevin F.; Dubon, Oscar D.; Bartelt, Norman C.

    2015-04-20

    Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, ‘ripening’; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV per C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene–substrate interaction reproduces the results. This study suggests new strategies for improving the van der Waals epitaxy of 2D materials.

  2. Real-time observation of epitaxial graphene domain reorientation

    DOE PAGES

    Thuermer, Konrad; Foster, Michael E.; Bartelt, Norman Charles; ...

    2015-04-20

    Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, ‘ripening’; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV permore » C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene–substrate interaction reproduces the results. This study suggests new strategies for improving the van der Waals epitaxy of 2D materials.« less

  3. Rater Drift and Time Trends in Classroom Observations

    ERIC Educational Resources Information Center

    Casabianca, Jodi M.; Lockwood, J. R.

    2013-01-01

    Classroom observation protocols, in which observers rate multiple dimensions of teaching according to established protocols (either live in the classroom, or post-hoc from lesson videos), are increasingly being used in both research and policy contexts. However, scores generated from these protocols have many sources of error. Day to day variation…

  4. Information and Complexity Measures Applied to Observed and Simulated Soil Moisture Time Series

    USDA-ARS?s Scientific Manuscript database

    Time series of soil moisture-related parameters provides important insights in functioning of soil water systems. Analysis of patterns within these time series has been used in several studies. The objective of this work was to compare patterns in observed and simulated soil moisture contents to u...

  5. [Critical reading of analytical observational studies].

    PubMed

    García Villar, C; Marín León, I

    2015-11-01

    Analytical observational studies provide very important information about real-life clinical practice and the natural history of diseases and can suggest causality. Furthermore, they are very common in scientific journals. The aim of this article is to review the main concepts necessary for the critical reading of articles about radiological studies with observational designs. It reviews the characteristics that case-control and cohort studies must have to ensure high quality. It explains a method of critical reading that involves checking the attributes that should be evaluated in each type of article using a structured list of specific questions. It underlines the main characteristics that confer credibility and confidence on the article evaluated. Readers are provided with tools for the critical analysis of the observational studies published in scientific journals. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  6. Impact of duration of structured observations on measurement of handwashing behavior at critical times

    PubMed Central

    2013-01-01

    Background Structured observation is frequently used to measure handwashing at critical events, such as after fecal contact and before eating, but it is time-consuming. We aimed to assess the impact of reducing the duration of structured observation on the number and type of critical events observed. Methods The study recruited 100 randomly selected households, 50 for short 90-minute observations and 50 for long 5-hour observations, in six rural Bangladeshi villages. Based on the first 90 minutes in the long observation households, we estimated the number of critical events for handwashing expected, and compared the expected number to the number of events actually observed in the short observation households. In long observation households, we compared soap use at critical events observed during the first 90 minutes to soap use at events observed during the latter 210 minutes of the 5-hour duration. Results In short 90-minute observation households, the mean number of events observed was lower than the number of events expected: before eating (observed 0.25, expected 0.45, p < 0.05) and after defecation (observed 0.0, expected 0.03, p = 0.06). However, the mean number observed was higher than the expected for food preparation, food serving, and child feeding events. In long 5-hour observation households, soap was used more frequently at critical events observed in the first 90 minutes than in the remaining 210 minutes, but this difference was not significant (p = 0.29). Conclusions Decreasing the duration of handwashing significantly reduced the observation of critical events of interest to evaluators of handwashing programs. Researchers seeking to measure observed handwashing behavior should continue with prolonged duration of structured observation. Future research should develop and evaluate novel models to reduce reactivity to observation and improve the measurement of handwashing behavior. PMID:23915098

  7. An observational study describing the geographic-time distribution of cardiac arrests in Singapore: what is the utility of geographic information systems for planning public access defibrillation? (PADS Phase I).

    PubMed

    Ong, Marcus Eng Hock; Tan, Eng Hoe; Yan, Xiuyuan; Anushia, P; Lim, Swee Han; Leong, Benjamin Sieu-Hon; Ong, Victor Yeok Kein; Tiah, Ling; Yap, Susan; Overton, Jerry; Anantharaman, V

    2008-03-01

    Public access defibrillation (PAD) has shown potential to increase cardiac arrest survival rates. To describe the geographic epidemiology of prehospital cardiac arrest in Singapore using geographic information systems (GIS) technology and assess the potential for deployment of a PAD program. We conducted an observational prospective study looking at the geographic location of pre-hospital cardiac arrests in Singapore. Included were all patients with out-of-hospital cardiac arrest (OHCA) presented to emergency departments. Patient characteristics, cardiac arrest circumstances, emergency medical service (EMS) response and outcomes were recorded according to the Utstein style. Location of cardiac arrests was spot-mapped using GIS. From 1 October 2001 to 14 October 2004, 2428 patients were enrolled into the study. Mean age for arrests was 60.6 years with 68.0% male. 67.8% of arrests occurred in residences, with 54.5% bystander witnessed and another 10.5% EMS witnessed. Mean EMS response time was 9.6 min with 21.7% receiving prehospital defibrillation. Cardiac arrest occurrence was highest in the suburban town centers in the Eastern and Southern part of the country. We also identified communities with the highest arrest rates. About twice as many arrests occurred during the day (07:00-18:59 h) compared to night (19:00-06:59 h). The categories with the highest frequencies of occurrence included residential areas, in vehicles, healthcare facilities, along roads, shopping areas and offices/industrial areas. We found a definite geographical distribution pattern of cardiac arrest. This study demonstrates the utility of GIS with a national cardiac arrest database and has implications for implementing a PAD program, targeted CPR training, AED placement and ambulance deployment.

  8. Prevalence of cervical colonization by Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis and Mycoplasma genitalium in childbearing age women by a commercially available multiplex real-time PCR: An Italian observational multicentre study.

    PubMed

    Leli, Christian; Mencacci, Antonella; Latino, Maria Agnese; Clerici, Pierangelo; Rassu, Mario; Perito, Stefano; Castronari, Roberto; Pistoni, Eleonora; Luciano, Eugenio; De Maria, Daniela; Morazzoni, Cristina; Pascarella, Michela; Bozza, Silvia; Sensini, Alessandra

    2017-06-28

    Mycoplasmas are frequently isolated from the genital tract. New molecular PCR-based methods for the detection of mycoplasmas can better define the real epidemiology of these microorganisms. The aim of this study was to evaluate the prevalence of mycoplasmas in a population of childbearing age women by means of PCR. This 21-month multicentre observational study was conducted at four Italian clinical microbiology laboratories. Women reporting symptoms of vaginitis/cervicitis, or with history of infertility, pregnancy, miscarriage or preterm birth were included. Detection of Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma genitalium was performed from cervical swabs by means of a commercially available multiplex real-time PCR. a total of 1761 women fulfilled the inclusion criteria and were included in the study. The overall prevalence was: U. parvum 38.3%, U. urealyticum 9%, M. hominis 8.6% and M. genitalium 0.6%. The proportion of foreign patients positive for U. parvum was significantly higher compared to Italian patients (37% vs 30.1%, p = 0.007) and also for overall mycoplasma colonization (53.4% vs 45.8%, p = 0.011). The number of symptomatic patients positive for M. hominis was significantly higher than that of negative controls (2.9% vs 1%, p = 0.036). A significant positive trend in mycoplasma colonization was found in relation to the pregnancy week for U. urealyticum (p = 0.015), M. hominis (p = 0.044) and for overall mycoplasma colonization (p = 0.002). multiplex RT-PCR can be a valuable tool to evaluate the real epidemiology of cervical mycoplasma colonization. Copyright © 2017. Published by Elsevier B.V.

  9. Novae a theoretical and observational study

    NASA Astrophysics Data System (ADS)

    Soraisam, Monika D.

    2016-02-01

    In this thesis, we present studies relating to novae that include both theoretical and ob- servational aspects. Being hosted by accreting white dwarfs (WDs), they have drawn attention in the context of the supernova Ia (SN Ia) progenitor problem. In the case of the nova explosion, the WD host is not disrupted. Instead, it continues to supply energy, even after the optical outbust, via stable nuclear burning of the remnant hydrogen envelope that survived the outburst. Accordingly, nova emission progresses toward the harder part of the electromagnetic spectrum, where it lasts longer than in the optical regime. As a consequence, novae are found to constitute the majority of the observed supersoft X-ray sources (SSSs). This is particularly well established for the galaxy M31. For high mass accretion rates in the unstable nuclear burning regime (or nova regime), there is evidence that significant mass accumulation by the WD is possible. This paved the way for SN Ia progenitor models in the single degenerate (SD) scenario involving novae. Based on the statistics of novae in M31, which is the most frequently used target for nova surveys, we investigate the role that novae may play in producing SNe Ia. Using multicycle nova evolution models and the observationally inferred nova rate in M31, we estimate the maximal SN Ia rate that novae can produce, assuming that all of the involved WDs reach the Chandrasekhar mass. Comparing this rate to the observationally inferred SN Ia rate for M31 constrains the contribution of the nova channel to the SN Ia rate to 2-7%. Additionally, we demonstrate that a more powerful diagnostic can be obtained from statistics of fast novae, which are characterized by decline times t2 10 days. Most novae resulting from a typical SD SN Ia progenitor accreting in the nova regime are fast. Specifically, as the WD in the nova grows in mass, it produces novae more frequently and with decreasing decline times. We therefore investigate how efficiently fast

  10. 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.

  11. 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.

  12. Effect of Information Load and Time on Observational Learning

    ERIC Educational Resources Information Center

    Breslin, Gavin; Hodges, Nicola J.; Williams, A. Mark

    2009-01-01

    We examined whether altering the amount of and moment when visual information is presented affected observational learning for participants practicing a bowling skill. On Day 1, four groups practiced a cricket bowling action. Three groups viewed a full-body point-light model, the model's bowling arm, or between-limb coordination of the model's…

  13. Effect of Information Load and Time on Observational Learning

    ERIC Educational Resources Information Center

    Breslin, Gavin; Hodges, Nicola J.; Williams, A. Mark

    2009-01-01

    We examined whether altering the amount of and moment when visual information is presented affected observational learning for participants practicing a bowling skill. On Day 1, four groups practiced a cricket bowling action. Three groups viewed a full-body point-light model, the model's bowling arm, or between-limb coordination of the model's…

  14. Multicenter observational prehospital resuscitation on helicopter study.

    PubMed

    Holcomb, John B; Swartz, Michael D; DeSantis, Stacia M; Greene, Thomas J; Fox, Erin E; Stein, Deborah M; Bulger, Eileen M; Kerby, Jeffrey D; Goodman, Michael; Schreiber, Martin A; Zielinski, Martin D; O'Keeffe, Terence; Inaba, Kenji; Tomasek, Jeffrey S; Podbielski, Jeanette M; Appana, Savitri N; Yi, Misung; Wade, Charles E

    2017-07-01

    Earlier use of in-hospital plasma, platelets, and red blood cells (RBCs) has improved survival in trauma patients with severe hemorrhage. Retrospective studies have associated improved early survival with prehospital blood product transfusion (PHT). We hypothesized that PHT of plasma and/or RBCs would result in improved survival after injury in patients transported by helicopter. Adult trauma patients transported by helicopter from the scene to nine Level 1 trauma centers were prospectively observed from January to November 2015. Five helicopter systems had plasma and/or RBCs, whereas the other four helicopter systems used only crystalloid resuscitation. All patients meeting predetermined high-risk criteria were analyzed. Patients receiving PHT were compared with patients not receiving PHT. Our primary analysis compared mortality at 3 hours, 24 hours, and 30 days, using logistic regression to adjust for confounders and site heterogeneity to model patients who were matched on propensity scores. Twenty-five thousand one hundred eighteen trauma patients were admitted, 2,341 (9%) were transported by helicopter, of which 1,058 (45%) met the highest-risk criteria. Five hundred eighty-five of 1,058 patients were flown on helicopters carrying blood products. In the systems with blood available, prehospital median systolic blood pressure (125 vs 128) and Glasgow Coma Scale (7 vs 14) was significantly lower, whereas median Injury Severity Score was significantly higher (21 vs 14). Unadjusted mortality was significantly higher in the systems with blood products available, at 3 hours (8.4% vs 3.6%), 24 hours (12.6% vs 8.9%), and 30 days (19.3% vs 13.3%). Twenty-four percent of eligible patients received a PHT. A median of 1 unit of RBCs and plasma were transfused prehospital. Of patients receiving PHT, 24% received only plasma, 7% received only RBCs, and 69% received both. In the propensity score matching analysis (n = 109), PHT was not significantly associated with mortality

  15. Kalman Filtering USNO's GPS Observations for Improved Time Transfer Predictions

    NASA Technical Reports Server (NTRS)

    Hutsell, Steven T.

    1996-01-01

    The Global Positioning System (GPS) Master Control Station (MCS) performs the Coordinated Universal Time (UTC) time transfer mission by uploading and broadcasting predictions of the GPS-UTC offset in subframe 4 of the GS navigation message. These predictions are based on only two successive daily data points obtained from the US Naval Observatory (USNO). USNO produces these daily smoothed data points by performing a least-squares fit on roughly 38 hours worth of data from roughly 160 successive 13-minute tracks of GPS satellites. Though sufficient for helping to maintain a time transfer error specification of 28 ns (1 Sigma), the MCS's prediction algorithm does not make the best use of the available data from from USNO, and produces data that can degrade quickly over extended prediction spans. This paper investigates how, by applying Kalman filtering to the same available tracking data, the MCS could improve its estimate of GPS-UTC, and in particular, the GPS-UTC A(sub 1) term. By refining the A(sub 1) (frequency) estimate for GPS-UTC predictions, error in GPS time transfer could drop significantly. Additional, the risk of future spikes in GPS's time transfer error could similarly be minimized, by employing robust Kalman filtering for GPS-UTC predictions.

  16. Daylight saving time as a potential public health intervention: an observational study of evening daylight and objectively-measured physical activity among 23,000 children from 9 countries.

    PubMed

    Goodman, Anna; Page, Angie S; Cooper, Ashley R

    2014-10-23

    It has been proposed that introducing daylight saving measures could increase children's physical activity, but there exists little research on this issue. This study therefore examined associations between time of sunset and activity levels, including using the bi-annual 'changing of the clocks' as a natural experiment. 23,188 children aged 5-16 years from 15 studies in nine countries were brought together in the International Children's Accelerometry Database. 439 of these children were of particular interest for our analyses as they contributed data both immediately before and after the clocks changed. All children provided objectively-measured physical activity data from Actigraph accelerometers, and we used their average physical activity level (accelerometer counts per minute) as our primary outcome. Date of accelerometer data collection was matched to time of sunset, and to weather characteristics including daily precipitation, humidity, wind speed and temperature. Adjusting for child and weather covariates, we found that longer evening daylight was independently associated with a small increase in daily physical activity. Consistent with a causal interpretation, the magnitude of these associations was largest in the late afternoon and early evening and these associations were also evident when comparing the same child just before and just after the clocks changed. These associations were, however, only consistently observed in the five mainland European, four English and two Australian samples (adjusted, pooled effect sizes 0.03-0.07 standard deviations per hour of additional evening daylight). In some settings there was some evidence of larger associations between daylength and physical activity in boys. There was no evidence of interactions with weight status or maternal education, and inconsistent findings for interactions with age. In Europe and Australia, evening daylight seems to play a causal role in increasing children's activity in a relatively

  17. Induced Time-Reversal Symmetry Breaking Observed in Microwave Billiards

    SciTech Connect

    Dietz, B.; Friedrich, T.; Miski-Oglu, M.; Richter, A.; Schaefer, F.; Harney, H. L.; Weidenmueller, H. A.

    2007-02-16

    Using reciprocity, we investigate the breaking of time-reversal (T) symmetry due to a ferrite embedded in a flat microwave billiard. Transmission spectra of isolated single resonances are not sensitive to T violation, whereas those of pairs of nearly degenerate resonances do depend on the direction of time. For their theoretical description a scattering matrix model from nuclear physics is used. The T-violating matrix elements of the effective Hamiltonian for the microwave billiard with the embedded ferrite are determined experimentally as functions of the magnetization of the ferrite.

  18. Real-time observation of collective excitations in photoemission

    NASA Astrophysics Data System (ADS)

    Lemell, C.; Neppl, S.; Wachter, G.; Tőkési, K.; Ernstorfer, R.; Feulner, P.; Kienberger, R.; Burgdörfer, J.

    2015-06-01

    Ejection of an electron by absorption of an extreme ultraviolet (xuv) photon probes the many-electron response of a solid well beyond the single-particle picture. Photoemission spectra feature complex correlation satellite structures signifying the simultaneous excitation of single or multiple plasmons. The time delay of the plasmon satellites relative to the main line can be resolved in attosecond streaking experiments. Time-resolved photoemission thus provides the key to discriminate between intrinsic and extrinsic plasmon excitation. We demonstrate the determination of the branching ratio between intrinsic and extrinsic plasmon generation for simple metals.

  19. Induced time-reversal symmetry breaking observed in microwave billiards.

    PubMed

    Dietz, B; Friedrich, T; Harney, H L; Miski-Oglu, M; Richter, A; Schäfer, F; Weidenmüller, H A

    2007-02-16

    Using reciprocity, we investigate the breaking of time-reversal (T) symmetry due to a ferrite embedded in a flat microwave billiard. Transmission spectra of isolated single resonances are not sensitive to T violation, whereas those of pairs of nearly degenerate resonances do depend on the direction of time. For their theoretical description a scattering matrix model from nuclear physics is used. The T-violating matrix elements of the effective Hamiltonian for the microwave billiard with the embedded ferrite are determined experimentally as functions of the magnetization of the ferrite.

  20. Child Study and Observation: Child Development 101.

    ERIC Educational Resources Information Center

    Jones, Joanna

    This syllabus outlines the structure, objectives, and lesson plans for Child Development 101, a twelve-week course on child study and observation offered at Chaffey Community College. A statement of the educational philosophy upon which the course was developed precedes a list of course objectives, competencies, and the grading system. The bulk of…

  1. Workplace Education Initiative: Case Studies and Observations.

    ERIC Educational Resources Information Center

    Astrein, Bruce; And Others

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

  2. Determination of the distance between two adjacent stations, the observational vertical increment and the observational time interval in optimum sense

    NASA Astrophysics Data System (ADS)

    Liao, Dongxian

    1985-08-01

    Considering the observational error, the truncation error and the requirements of numerical weather prediction, three formulas for determining the distance between two adjacent stations d 1, the observational vertical increment Δ p 1 and the observational time interval Δ t 1 in optimum sense, have been derived. Since they depend on the shortest wavelength concerned and the ratio of maximum observational error to wave amplitude, the results are quite different for different scale systems. For the filtered model the values of d 1, Δ p 1, and Δ t 1 general come near those required in the MANUAL on the GOS published in 1980 by WMO. But for the primitive equation model the estimated value of Δ t 1 is much less than those required in the filtered model case. Therefore, it is improper to study the fast moving and developing processes of the atmospheric motion only on the basis of the conventional observations. It seems to be necessary to establish an optimum composite observational system including the surface-based system and the space-based system.

  3. Regression modeling of longitudinal data with outcome-dependent observation times: extensions and comparative evaluation.

    PubMed

    Tan, Kay See; French, Benjamin; Troxel, Andrea B

    2014-11-30

    Conventional longitudinal data analysis methods assume that outcomes are independent of the data-collection schedule. However, the independence assumption may be violated, for example, when a specific treatment necessitates a different follow-up schedule than the control arm or when adverse events trigger additional physician visits in between prescheduled follow-ups. Dependence between outcomes and observation times may introduce bias when estimating the marginal association of covariates on outcomes using a standard longitudinal regression model. We formulate a framework of outcome-observation dependence mechanisms to describe conditional independence given observed observation-time process covariates or shared latent variables. We compare four recently developed semi-parametric methods that accommodate one of these mechanisms. To allow greater flexibility, we extend these methods to accommodate a combination of mechanisms. In simulation studies, we show how incorrectly specifying the outcome-observation dependence may yield biased estimates of covariate-outcome associations and how our proposed extensions can accommodate a greater number of dependence mechanisms. We illustrate the implications of different modeling strategies in an application to bladder cancer data. In longitudinal studies with potentially outcome-dependent observation times, we recommend that analysts carefully explore the conditional independence mechanism between the outcome and observation-time processes to ensure valid inference regarding covariate-outcome associations.

  4. Radar and satellite observations of the storm time cleft

    NASA Astrophysics Data System (ADS)

    Yeh, H.-C.; Foster, J. C.; Holt, J. M.; Redus, R. H.; Rich, F. J.

    1990-08-01

    A combination is made of observations from the Millstone Hill radar (MHR) and the Defense Meteorological Satellite Program's F7 spacecraft of the dayside features on the ionospheric cleft/cusp during the magnetic storm of February 8-9, 1986; the MHR was in the dayside. Attention is given to the two sets of observations for the prenoon sector in order to ascertain the low-altitude signatures of plasma regions in the vicinity of the cusp. Boundary plasma sheet particles coincided with a narrow region of magnetic field-aligned currents, as well as with antisunward convection flows at the equatorward edge of the cleft. Particle and field signatures are identified for the plasma sheet, plasma sheet boundary layer, low latitude boundary layer, cusp, and mantle, at unusually low magnetic latitude during the event.

  5. Finding the times that SMMR observed a ship

    NASA Technical Reports Server (NTRS)

    1979-01-01

    In order to facilitate the coincidence calculations, the coordinates of the ship and the satellite were transformed to the ECO system in which the equatorial plane is the plane of the satellite's orbit. The transformation matrices for each step are presented. The ship could be observed when it was in a band about the equator in the ECO system. The width of the band was determined by the scan pattern of the instrument.

  6. Time Resolved Atmospheric Carbon Satellite Observations from Geostationary Orbit

    NASA Astrophysics Data System (ADS)

    Edwards, David; Worden, Helen

    This presentation describes proposed satellite carbon measurements from CHRONOS (Commercially Hosted spectroRadiometer Observations and New Opportunities for Science). The primary goal of this mission is to measure the atmospheric pollutants carbon monoxide (CO) and methane (CH4) from geostationary orbit, with hourly observations of North America at high spatial resolution. Carbon monoxide is produced by combustion processes such as urban activity and wildfires, and serves as a proxy for other combustion pollutants that are not easily measured. Both CO and CH4 are chemical precursors of tropospheric ozone pollution. Methane has diverse anthropogenic sources ranging from fossil fuel production, animal husbandry, agriculture and waste management. The impact of gas exploration in the Western States of the USA and oil extraction from the Canadian tar sands will be particular foci of the mission, as will the poorly-quantified natural CH4 emissions from wetlands and thawing permafrost. In addition to characterizing pollutant sources, improved understanding of the domestic CH4 budget is a priority for policy decisions related to short-lived climate forcers. A primary motivation for targeting CO is its value as a tracer of atmospheric pollution. The CHRONOS measurements will provide insight into local and long-range transport across the North American continent, as well as the processes governing the entrainment and venting of pollution in and out of the planetary boundary layer. As a result of significantly improved characterization of diurnal changes in atmospheric composition, CHRONOS observations will find direct societal applications for air quality regulation and forecasting. We present a quantification of this expected improvement in the prediction of near-surface concentrations when CHRONOS measurements are used in Observation System Simulation Experiments (OSSEs). If CHRONOS and the planned NASA Earth Venture TEMPO (Tropospheric Emissions: Monitoring of Pollution

  7. Active Control of Compressor Surge Using a Real Time Observer

    DTIC Science & Technology

    2001-06-01

    Engines at the Georgia No. 98-GT-475, 1998. Institute of Technology sponsored by the U.S. Army 12. Grauer , F., Volgmann, W., Stoff, H. and Breuer...Verlag, 1991. 11-10 PAPER -11, J. Prasad Question (F. Grauer , Germany) Was the detector influenced by the blade passing frequencies? Reply No, the...observer could be selected to operate over a range of frequencies, thus eliminat- ing other frequencies. Question (F. Grauer , Germany) Do you expect your

  8. Time Resolved Atmospheric Carbon Satellite Observations from Geostationary Orbit

    NASA Astrophysics Data System (ADS)

    Edwards, D. P.; Worden, H. M.; Deeter, M. N.; Worden, H. M.

    2013-12-01

    This presentation describes proposed satellite carbon measurements from CHRONOS (Commercially Hosted spectroRadiometer Observations and New Opportunities for Science). The primary goal of this mission is to measure the atmospheric pollutants carbon monoxide (CO) and methane (CH4) from geostationary orbit, with hourly observations of North America at high spatial resolution. Carbon monoxide is produced by combustion processes such as urban activity and wildfires, and serves as a proxy for other combustion pollutants that are not easily measured. Both CO and CH4 are chemical precursors of tropospheric ozone pollution. Methane has diverse anthropogenic sources ranging from fossil fuel production, animal husbandry, agriculture and waste management. The impact of gas exploration in the Western States of the USA and oil extraction from the Canadian tar sands will be particular foci of the mission, as will the poorly-quantified natural CH4 emissions from wetlands and thawing permafrost. In addition to characterizing pollutant sources, improved understanding of the domestic CH4 budget is a priority for policy decisions related to short-lived climate forcers. A primary motivation for targeting CO is its value as a tracer of atmospheric pollution. The CHRONOS measurements will provide insight into local and long-range transport across the North American continent, as well as the processes governing the entrainment and venting of pollution in and out of the planetary boundary layer. As a result of significantly improved characterization of diurnal changes in atmospheric composition, CHRONOS observations will find direct societal applications for air quality regulation and forecasting. We present a quantification of this expected improvement in the prediction of near-surface concentrations when CHRONOS measurements are used in Observation System Simulation Experiments (OSSEs). If CHRONOS and the planned NASA Earth Venture TEMPO (Tropospheric Emissions: Monitoring of Pollution

  9. Near-Real-Time Earth Observation Data Supporting Wildfire Management

    NASA Astrophysics Data System (ADS)

    Ambrosia, V. G.; Zajkowski, T.; Quayle, B.

    2013-12-01

    During disaster events, the most critical element needed by responding personnel and management teams is situational intelligence / awareness. During rapidly-evolving events such as wildfires, the need for timely information is critical to save lives, property and resources. The wildfire management agencies in the US rely heavily on remote sensing information both from airborne platforms as well as from orbital assets. The ability to readily have information from those systems, not just data, is critical to effective control and damage mitigation. NASA has been collaborating with the USFS to mature and operationalize various asset-information capabilities to effect improved knowledge of fire-prone areas, monitor wildfire events in real-time, assess effectiveness of fire management strategies, and provide rapid, post-fire assessment for recovery operations. Specific examples of near-real-time remote sensing asset utility include daily MODIS data employed to assess fire potential / wildfire hazard areas, and national-scale hot-spot detection, airborne thermal sensor collected during wildfire events to effect management strategies, EO-1 ALI 'pointable' satellite sensor data to assess fire-retardant application effectiveness, and Landsat 8 and other sensor data to derive burn severity indices for post-fire remediation work. These cases of where near-real-time data is used operationally during the previous few fire seasons will be presented.

  10. United States forest disturbance trends observed with landsat time series

    Treesearch

    Jeffrey G. Masek; Samuel N. Goward; Robert E. Kennedy; Warren B. Cohen; Gretchen G. Moisen; Karen Schleweiss; Chengquan. Huang

    2013-01-01

    Disturbance events strongly affect the composition, structure, and function of forest ecosystems; however, existing US land management inventories were not designed to monitor disturbance. To begin addressing this gap, the North American Forest Dynamics (NAFD) project has examined a geographic sample of 50 Landsat satellite image time series to assess trends in forest...

  11. Time as an Observable in Nonrelativistic Quantum Mechanics

    NASA Technical Reports Server (NTRS)

    Hahne, G. E.

    2003-01-01

    The argument follows from the viewpoint that quantum mechanics is taken not in the usual form involving vectors and linear operators in Hilbert spaces, but as a boundary value problem for a special class of partial differential equations-in the present work, the nonrelativistic Schrodinger equation for motion of a structureless particle in four- dimensional space-time in the presence of a potential energy distribution that can be time-as well as space-dependent. The domain of interest is taken to be one of two semi-infinite boxes, one bounded by two t=constant planes and the other by two t=constant planes. Each gives rise to a characteristic boundary value problem: one in which the initial, input values on one t=constant wall are given, with zero asymptotic wavefunction values in all spatial directions, the output being the values on the second t=constant wall; the second with certain input values given on both z=constant walls, with zero asymptotic values in all directions involving time and the other spatial coordinates, the output being the complementary values on the z=constant walls. The first problem corresponds to ordinary quantum mechanics; the second, to a fully time-dependent version of a problem normally considered only for the steady state (time-independent Schrodinger equation). The second problem is formulated in detail. A conserved indefinite metric is associated with space-like propagation, where the sign of the norm of a unidirectional state corresponds to its spatial direction of travel.

  12. Observational constraints to boxy/peanut bulge formation time

    NASA Astrophysics Data System (ADS)

    Pérez, I.; Martínez-Valpuesta, I.; Ruiz-Lara, T.; de Lorenzo-Caceres, A.; Falcón-Barroso, J.; Florido, E.; González Delgado, R. M.; Lyubenova, M.; Marino, R. A.; Sánchez, S. F.; Sánchez-Blázquez, P.; van de Ven, G.; Zurita, A.

    2017-09-01

    Boxy/peanut bulges are considered to be part of the same stellar structure as bars and both could be linked through the buckling instability. The Milky Way is our closest example. The goal of this Letter is to determine if the mass assembly of the different components leaves an imprint in their stellar populations allowing the estimation the time of bar formation and its evolution. To this aim, we use integral field spectroscopy to derive the stellar age distributions, SADs, along the bar and disc of NGC 6032. The analysis clearly shows different SADs for the different bar areas. There is an underlying old (≥12 Gyr) stellar population for the whole galaxy. The bulge shows star formation happening at all times. The inner bar structure shows stars of ages older than 6 Gyr with a deficit of younger populations. The outer bar region presents an SAD similar to that of the disc. To interpret our results, we use a generic numerical simulation of a barred galaxy. Thus, we constrain, for the first time, the epoch of bar formation, the buckling instability period and the posterior growth from disc material. We establish that the bar of NGC 6032 is old, formed around 10 Gyr ago while the buckling phase possibly happened around 8 Gyr ago. All these results point towards bars being long-lasting even in the presence of gas.

  13. Time to Tango: expertise and contextual anticipation during action observation.

    PubMed

    Amoruso, Lucía; Sedeño, Lucas; Huepe, David; Tomio, Ailin; Kamienkowski, Juan; Hurtado, Esteban; Cardona, Juan Felipe; Álvarez González, Miguel Ángel; Rieznik, Andrés; Sigman, Mariano; Manes, Facundo; Ibáñez, Agustín

    2014-09-01

    Predictive theories of action observation propose that we use our own motor system as a guide for anticipating and understanding other people's actions through the generation of context-based expectations. According to this view, people should be better in predicting and interpreting those actions that are present in their own motor repertoire compared to those that are not. We recorded high-density event-related potentials (ERPs: P300, N400 and Slow Wave, SW) and source estimation in 80 subjects separated by their level of expertise (experts, beginners and naïves) as they observed realistic videos of Tango steps with different degrees of execution correctness. We also performed path analysis to infer causal relationships between ongoing anticipatory brain activity, evoked semantic responses, expertise measures and behavioral performance. We found that anticipatory activity, with sources in a fronto-parieto-occipital network, early discriminated between groups according to their level of expertise. Furthermore, this early activity significantly predicted subsequent semantic integration indexed by semantic responses (N400 and SW, sourced in temporal and motor regions) which also predicted motor expertise. In addition, motor expertise was a good predictor of behavioral performance. Our results show that neural and temporal dynamics underlying contextual action anticipation and comprehension can be interpreted in terms of successive levels of contextual prediction that are significantly modulated by subject's prior experience.

  14. TIME-DEPENDENT INFRARED STUDIES.

    DTIC Science & Technology

    INFRARED RESEARCH, TIME , INFRARED PHENOMENA, INFRARED RADIATION, INFRARED SPECTROSCOPY, HIGH ALTITUDE, SOLAR ATMOSPHERE, TRANSMISSIONS(MECHANICAL), VIBRATION, QUANTUM THEORY, CALIBRATION, INFRARED SCANNING.

  15. Observing Evolutionary Entropy in Relation to Body Size Over Time

    NASA Astrophysics Data System (ADS)

    Idgunji, S.; Zhang, H.; Payne, J.; Heim, N. A.

    2015-12-01

    The Second Law of Thermodynamics, according to Clausius, states that entropy will always increase in the universe, meaning systems will break down and become simple and chaotic. However, this is seemingly contradicted by the existence of living organisms, which can have highly complex and organized systems. Furthermore, there is a greater contradiction in the theory of evolution, which sees organisms growing larger and becoming more complex over time. Our research project revolved around whether organisms actually became more complex over time, and correlating these findings with the body size of these organisms. We analyzed the relationship between body size and cell types of five different marine phyla: arthropods, brachiopods, chordates, echinoderms, and mollusks. We attempted to find a relation between the biovolume of these different phyla and the number of specialized cell types that they had, which is a common measure of biocomplexity. In addition, we looked at the metabolic intensity, which is the mass-specific rate of energy processing applied to an organism's size, because it is also correlated to genetic complexity. Using R programming, we tested for correlations between these factors. After applying a Pearson correlation test, we discovered a generally positive correlation between the body sizes, number of cell types, and metabolic intensities of these phyla. However, one exception is that there is a negative correlation between the body size and metabolic intensity of echinoderms. Overall, we can see that marine organisms tend to evolve larger and more complex over time, and that is a very interesting find. Our discovery yielded many research questions and problems that we would like to solve, such as how the environment is thermodynamically affected by these organisms.

  16. PBO Integrated Real-Time Observing Sites at Volcanic Sites

    NASA Astrophysics Data System (ADS)

    Mencin, D.; Jackson, M.; Borsa, A.; Feaux, K.; Smith, S.

    2009-05-01

    The Plate Boundary Observatory, an element of NSF's EarthScope program, has six integrated observatories in Yellowstone and four on Mt St Helens. These observatories consist of some combination of borehole strainmeters, borehole seismometers, GPS, tiltmeters, pore pressure, thermal measurements and meteorological data. Data from all these instruments have highly variable data rates and formats, all synchronized to GPS time which can cause significant congestion of precious communication resources. PBO has been experimenting with integrating these data streams to both maximize efficiency and minimize latency through the use of software that combines the streams, like Antelope, and VPN technologies.

  17. LOTIS: GRB follow-up observations at early times

    SciTech Connect

    Park, H S

    1999-02-22

    LOTIS is an automated wide field-of-view telescope system capable of responding to GRB events as early as 10s after a trigger from the GCN which rapidly distributes coordinates from the Beppo/SAX, BATSE and RXTE instruments. Measurements of optical activity at these early times will provide important clues to the GRB production mechanism. In over two year's of operation, LOTIS has responded to 40 GCN triggers including GRB971217 with l10s and GRB980703 within 5 hours. We report results from these events and constraints on simultaneous optical signals during these GRB's.

  18. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VIII. CATALOG OF TRANSIT TIMING MEASUREMENTS OF THE FIRST TWELVE QUARTERS

    SciTech Connect

    Mazeh, Tsevi; Nachmani, Gil; Holczer, Tomer; Sokol, Gil; Fabrycky, Daniel C.; Ford, Eric B.; Ragozzine, Darin; Sanchis-Ojeda, Roberto; Rowe, Jason F.; Lissauer, Jack J.; Zucker, Shay; Agol, Eric; Carter, Joshua A.; Quintana, Elisa V.; Steffen, Jason H.; Welsh, William

    2013-10-01

    Following the works of Ford et al. and Steffen et al. we derived the transit timing of 1960 Kepler objects of interest (KOIs) using the pre-search data conditioning light curves of the first twelve quarters of the Kepler data. For 721 KOIs with large enough signal-to-noise ratios, we obtained also the duration and depth of each transit. The results are presented as a catalog for the community to use. We derived a few statistics of our results that could be used to indicate significant variations. Including systems found by previous works, we have found 130 KOIs that showed highly significant times of transit variations (TTVs) and 13 that had short-period TTV modulations with small amplitudes. We consider two effects that could cause apparent periodic TTV—the finite sampling of the observations and the interference with the stellar activity, stellar spots in particular. We briefly discuss some statistical aspects of our detected TTVs. We show that the TTV period is correlated with the orbital period of the planet and with the TTV amplitude.

  19. Transit Timing Observations from Kepler. VIII. Catalog of Transit Timing Measurements of the First Twelve Quarters

    NASA Astrophysics Data System (ADS)

    Mazeh, Tsevi; Nachmani, Gil; Holczer, Tomer; Fabrycky, Daniel C.; Ford, Eric B.; Sanchis-Ojeda, Roberto; Sokol, Gil; Rowe, Jason F.; Zucker, Shay; Agol, Eric; Carter, Joshua A.; Lissauer, Jack J.; Quintana, Elisa V.; Ragozzine, Darin; Steffen, Jason H.; Welsh, William

    2013-10-01

    Following the works of Ford et al. and Steffen et al. we derived the transit timing of 1960 Kepler objects of interest (KOIs) using the pre-search data conditioning light curves of the first twelve quarters of the Kepler data. For 721 KOIs with large enough signal-to-noise ratios, we obtained also the duration and depth of each transit. The results are presented as a catalog for the community to use. We derived a few statistics of our results that could be used to indicate significant variations. Including systems found by previous works, we have found 130 KOIs that showed highly significant times of transit variations (TTVs) and 13 that had short-period TTV modulations with small amplitudes. We consider two effects that could cause apparent periodic TTV—the finite sampling of the observations and the interference with the stellar activity, stellar spots in particular. We briefly discuss some statistical aspects of our detected TTVs. We show that the TTV period is correlated with the orbital period of the planet and with the TTV amplitude.

  20. A Time Study of Plastic Surgery Residents.

    PubMed

    Lau, Frank H; Sinha, Indranil; Jiang, Wei; Lipsitz, Stuart R; Eriksson, Elof

    2016-05-01

    Resident work hours are under scrutiny and have been subject to multiple restrictions. The studies supporting these changes have not included data on surgical residents. We studied the workday of a team of plastic surgery residents to establish prospective time-study data of plastic surgery (PRS) residents at a single tertiary-care academic medical center. Five trained research assistants observed all residents (n = 8) on a PRS service for 10 weeks and produced minute-by-minute activity logs. Data collection began when the team first met in the morning and continued until the resident being followed completed all non-call activities. We analyzed our data from 3 perspectives: 1) time spent in direct patient care (DPC), indirect patient care, and didactic activities; 2) time spent in high education-value activities (HEAs) versus low education-value activities; and 3) resident efficiency. We defined HEAs as activities that surgeons must master; other activities were LEAs. We quantified resident efficiency in terms of time fragmentation and time spent waiting. A total of 642.4 hours of data across 50 workdays were collected. Excluding call, residents worked an average of 64.2 hours per week. Approximately 50.7% of surgical resident time was allotted to DPC, with surgery accounting for the largest segment of this time (34.8%). Time spent on HEAs demonstrated trended upward with higher resident level (P = 0.086). Time in spent in surgery was significantly associated with higher resident levels (P < 0.0001); 57.7% of activities require 4 minutes or less, suggesting that resident work was highly fragmented. Residents spent 10.7% of their workdays waiting for other services. In this first-time study of PRS residents, we found that compared with medicine trainees, surgical residents spent 3.23 times more time on DPC. High education-value activities comprised most of our residents' workdays. Surgery was the leading component of both DPC and HEAs. Our residents were highly

  1. Real-time observation of interfacial ions during electrocrystallization.

    PubMed

    Nakamura, Masashi; Banzai, Takahiro; Maehata, Yuto; Endo, Osamu; Tajiri, Hiroo; Sakata, Osami; Hoshi, Nagahiro

    2017-04-20

    Understanding the electrocrystallization mechanisms of metal cations is of importance for many industrial and scientific fields. We have determined the transitional structures during underpotential deposition (upd) of various metal cations on Au(111) electrode using time-resolved surface X-ray diffraction and step-scan IR spectroscopy. At the initial stage of upd, a characteristic intensity transient appears in the time-resolved crystal truncation rod depending on metal cations. Metal cations with relatively high coordination energies of hydration water are deposited in two steps: first, the hydrated metal cations approached the surface and are metastably located at the outer Helmholtz plane, then they are deposited via the destruction of the hydration shell. However, Tl(+) and Ag(+), which have low hydration energy, are rapidly adsorbed on Au(111) electrode without any metastable states of dehydration. Therefore, the deposition rate is strongly related to the coordination energy of the hydration water. Metal cations strongly interacting with the counter coadsorbed anions such as Cu(2+) in sulfuric acid causes the deposition rate to be slower because of the formation of complexes.

  2. PONDER - A Real time software backend for pulsar and IPS observations at the Ooty Radio Telescope

    NASA Astrophysics Data System (ADS)

    Naidu, Arun; Joshi, Bhal Chandra; Manoharan, P. K.; Krishnakumar, M. A.

    2015-06-01

    This paper describes a new real-time versatile backend, the Pulsar Ooty Radio Telescope New Digital Efficient Receiver (PONDER), which has been designed to operate along with the legacy analog system of the Ooty Radio Telescope (ORT). PONDER makes use of the current state of the art computing hardware, a Graphical Processing Unit (GPU) and sufficiently large disk storage to support high time resolution real-time data of pulsar observations, obtained by coherent dedispersion over a bandpass of 16 MHz. Four different modes for pulsar observations are implemented in PONDER to provide standard reduced data products, such as time-stamped integrated profiles and dedispersed time series, allowing faster avenues to scientific results for a variety of pulsar studies. Additionally, PONDER also supports general modes of interplanetary scintillation (IPS) measurements and very long baseline interferometry data recording. The IPS mode yields a single polarisation correlated time series of solar wind scintillation over a bandwidth of about four times larger (16 MHz) than that of the legacy system as well as its fluctuation spectrum with high temporal and frequency resolutions. The key point is that all the above modes operate in real time. This paper presents the design aspects of PONDER and outlines the design methodology for future similar backends. It also explains the principal operations of PONDER, illustrates its capabilities for a variety of pulsar and IPS observations and demonstrates its usefulness for a variety of astrophysical studies using the high sensitivity of the ORT.

  3. Ozone Lidar Observations for Air Quality Studies

    NASA Technical Reports Server (NTRS)

    Wang, Lihua; Newchurch, Mike; Kuang, Shi; Burris, John F.; Huang, Guanyu; Pour-Biazar, Arastoo; Koshak, William; Follette-Cook, Melanie B.; Pickering, Kenneth E.; McGee, Thomas J.; hide

    2015-01-01

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

  4. Non-parametric estimation for the difference or ratio of median failure times for paired observations.

    PubMed

    Jung, S H; Su, J Q

    1995-02-15

    We propose a non-parametric method to calculate a confidence interval for the difference or ratio of two median failure times for paired observations with censoring. The new method is simple to calculate, does not involve non-parametric density estimates, and is valid asymptotically even when the two underlying distribution functions differ in shape. The method also allows missing observations. We report numerical studies to examine the performance of the new method for practical sample sizes.

  5. High Time Resolution Studies with the GBT

    NASA Astrophysics Data System (ADS)

    Lewandowska, Natalia; Lynch, Ryan S.

    2017-01-01

    The detection of neutron stars 49 years ago has created many new and independent branches of research. In 1967, fast rotating neutron stars, or pulsars, became the first objects of this kind to be discovered at radio wavelengths -- more than 30years after their theoretical prediction.In spite of numerous studies throughout the years, the mechanism of the observed radio emission of pulsars is still not understood. Recent technological developments allow observations of pulsars with time resolutions extending into the nanoseconds range, providing a unique insight into the momentary state of a pulsar.Radio giant pulses are known to occur non-periodically in certain phase ranges, exhibit much higher peak flux densities than regular pulses, and to have pulse widths ranging from the micro- to nanoseconds. Their characteristics make them suitable for high time resolution studies. We present the first high time resolution observations of the original millisecond pulsar PSR B1937+21 carried out with the Robert C. Byrd Green Bank Radio Telescope.

  6. Association of onset to balloon and door to balloon time with long term clinical outcome in patients with ST elevation acute myocardial infarction having primary percutaneous coronary intervention: observational study.

    PubMed

    Shiomi, Hiroki; Nakagawa, Yoshihisa; Morimoto, Takeshi; Furukawa, Yutaka; Nakano, Akira; Shirai, Shinichi; Taniguchi, Ryoji; Yamaji, Kyohei; Nagao, Kazuya; Suyama, Tamaki; Mitsuoka, Hirokazu; Araki, Makoto; Takashima, Hiroyuki; Mizoguchi, Tetsu; Eisawa, Hiroshi; Sugiyama, Seigo; Kimura, Takeshi

    2012-05-23

    To evaluate the relation of symptom onset to balloon time and door to balloon time with long term clinical outcome in patients with ST segment elevation myocardial infarction (STEMI) having primary percutaneous coronary intervention. Observation of large cohort of patients with acute myocardial infarction. 26 tertiary hospitals in Japan. 3391 patients with STEMI who had primary percutaneous coronary intervention within 24 hours of symptom onset. Composite of death and congestive heart failure, compared by onset to balloon time and door to balloon time. Compared with an onset to balloon time greater than 3 hours, a time of less than 3 hours was associated with a lower incidence of a composite of death and congestive heart failure (13.5% (123/964) v 19.2% (429/2427), P<0.001; relative risk reduction 29.7%). After adjustment for confounders, a short onset to balloon time was independently associated with a lower risk of the composite endpoint (adjusted hazard ratio 0.70, 95% confidence interval 0.56 to 0.88; P=0.002). However, no significant difference was found in the incidence of a composite of death and congestive heart failure between the two groups of patients with short (≤90 minutes) and long (>90 minutes) door to balloon time (16.7% (270/1671) v 18.4% (282/1720), P=0.54; relative risk reduction 9.2%). After adjustment for confounders, no significant difference was seen in the risk of the composite endpoint between the two groups of patients with short and long door to balloon time (adjusted hazard ratio: 0.98, 0.78 to 1.24: P=0.87). A door to balloon time of less than 90 minutes was associated with a lower incidence of a composite of death and congestive heart failure in patients who presented within 2 hours of symptom onset (11.9% (74/883) v 18.1% (147/655), P=0.01; relative risk reduction 34.3%) but not in patients who presented later (19.7% (196/788) v 18.7% (135/1065), P=0.44; -5.3%). Short door to balloon time was independently associated with a lower

  7. Real-time observation of epitaxial graphene domain reorientation

    PubMed Central

    Rogge, Paul C.; Thürmer, Konrad; Foster, Michael E.; McCarty, Kevin F.; Dubon, Oscar D.; Bartelt, Norman C.

    2015-01-01

    Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, ‘ripening'; domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV per C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene–substrate interaction reproduces the results. This work suggests new strategies for improving the van der Waals epitaxy of 2D materials. PMID:25892219

  8. Real-time observation of epitaxial graphene domain reorientation

    NASA Astrophysics Data System (ADS)

    Rogge, Paul C.; Thürmer, Konrad; Foster, Michael E.; McCarty, Kevin F.; Dubon, Oscar D.; Bartelt, Norman C.

    2015-04-01

    Graphene films grown by vapour deposition tend to be polycrystalline due to the nucleation and growth of islands with different in-plane orientations. Here, using low-energy electron microscopy, we find that micron-sized graphene islands on Ir(111) rotate to a preferred orientation during thermal annealing. We observe three alignment mechanisms: the simultaneous growth of aligned domains and dissolution of rotated domains, that is, `ripening' domain boundary motion within islands; and continuous lattice rotation of entire domains. By measuring the relative growth velocity of domains during ripening, we estimate that the driving force for alignment is on the order of 0.1 meV per C atom and increases with rotation angle. A simple model of the orientation-dependent energy associated with the moiré corrugation of the graphene sheet due to local variations in the graphene-substrate interaction reproduces the results. This work suggests new strategies for improving the van der Waals epitaxy of 2D materials.

  9. Observing Holliday junction branch migration one step at a time

    NASA Astrophysics Data System (ADS)

    Ha, Taekjip

    2004-03-01

    During genetic recombination, two homologous DNA molecules undergo strand exchange to form a four-way DNA (Holliday) junction and the recognition and processing of this species by branch migration and junction resolving enzymes determine the outcome. We have used single molecule fluorescence techniques to study two intrinsic structural dynamics of the Holliday junction, stacking conformer transitions and spontaneous branch migration. Our studies show that the dynamics of branch migration, resolved with one base pair resolution, is determined by the stability of conformers which in turn depends on the local DNA sequences. Therefore, the energy landscape of Holliday junction branch migation is not uniform, but is rugged.

  10. An observational study of quiescent novae

    NASA Astrophysics Data System (ADS)

    Dhillon, V. S.

    1990-01-01

    Quiescent novae are close binary stars which are characterised by the presence of Balmer and HeII emission lines in their optical spectra. In high-inclination systems, standard theory predicts that one should observe double-peaked emission line profiles which are eclipsed once every orbital period. However, the emission lines of eclipsing quiescent novae are single-peaked and uneclipsed, in obvious conflict with currently held beliefs on the nature of these systems. It is the purpose of this thesis to solve this long-standing problem and so arrive at a theoretical model for quiescent novae which is consistent with the observational evidence. The first part of the thesis sets the scene to the problem by presenting an overview of the conflicting observational and theoretical results. The second part then reports on a number of new observations obtained during the course of this work which have shed new light on the problem. The results of these new observations are presented in Part III of the thesis, where one chapter is devoted to each of the three objects studied (V1315 Aquilae, SW Sextantis and DW Ursae Majoris). The final part of the thesis is a discussion and comparison of the various results presented in Part III. Using these results, a series of observational constraints are defined which are then applied to a number of existing theoretical models. In the case of V1315 Aql and SW Sex, the very stringent set of constraints results in there being no single model capable of explaining the observed phenomena. DW UMa is even more enigmatic, appearing in a previously unseen low-state during which the mass transfer rate appears to have reduced dramatically and the optical spectra are dominated by Balmer emission from the inner face of the secondary star. The implications of these new observations for the wider field of cataclysmic variables are discussed, followed by a short summary of future work necessary to validate the origin, evolution and behaviour of the

  11. Talk, Tools, and Tensions: Observing Biological Talk over Time

    ERIC Educational Resources Information Center

    Ash, Doris; Crain, Rhiannon; Brandt, Carol; Loomis, Molly; Wheaton, Mele; Bennett, Christine

    2007-01-01

    The goal of this study is to explore new tools for analyzing scientific sense-making in out-of-school settings. Although such measures are now common in science classroom research, dialogically based methodological approaches are relatively new to informal learning research. Such out-of-classroom settings have more recently become a breeding…

  12. Talk, Tools, and Tensions: Observing Biological Talk over Time

    ERIC Educational Resources Information Center

    Ash, Doris; Crain, Rhiannon; Brandt, Carol; Loomis, Molly; Wheaton, Mele; Bennett, Christine

    2007-01-01

    The goal of this study is to explore new tools for analyzing scientific sense-making in out-of-school settings. Although such measures are now common in science classroom research, dialogically based methodological approaches are relatively new to informal learning research. Such out-of-classroom settings have more recently become a breeding…

  13. Observational Signatures Of Agn Feedback Across Cosmic Time

    NASA Astrophysics Data System (ADS)

    Wylezalek, Dominika

    2017-06-01

    While many compelling models of AGN feedback exist, there is no clear data-driven picture of how winds are launched, how they propagate through the galaxy and what impact they have on the galactic gas. Recent work suggests that AGN luminosity plays an important role. The following described projects focus on understanding the power, reach and impact of feedback processes exerted by AGN of different power. I first describe recent efforts in our group of relating feedback signatures in powerful quasars to the specific star formation rate in their host galaxies, where our results are consistent with the AGN having a `negative' impact through feedback on the galaxies' star formation history. Feedback signatures seem to be best observable in gas-rich galaxies where the coupling of the AGN-driven wind to the gas is strongest, in agreement with recent simulations. But how and where does this quenching happen? Is it accomplished through the mechanical action of jets or through nuclear winds driven by radiation pressure? Finally, I show that AGN signatures and AGN-driven winds can be easily hidden and not be apparent in the integrated spectrum of a galaxy hosting a low/intermediate-luminosity AGN. Using data from the new SDSS-IV MaNGA survey, we have developed a new AGN selection algorithm tailored to IFU data and we are uncovering a much more nuanced picture of AGN activity allowing us to discover AGN signatures at large distances from the galaxy center. This implies that large IFU surveys, such as the SDSS-IV MaNGA survey, might uncover many previously unknown AGN and feedback signatures related to them. Outflows and feedback from low- and intermediate-luminosity AGN might have been underestimated in the past but can potentially significantly contribute to the AGN/host-galaxy self-regulation.

  14. Modeling the uncertainty associated with the observation scale of space/time natural processes

    NASA Astrophysics Data System (ADS)

    Lee, S.; Serre, M.

    2005-12-01

    In many mapping applications of spatiotemporally distributed hydrological processes, the traditional space/time Geostatistics approaches have played a significant role to estimate a variable of interest at unsampled locations. Measured values are usually sparsely located over space and time due to the difficulty and cost of obtaining data. In some cases, the data for the hydrological variable of interest may have been collected at different temporal or spatial observation scales. Even though mixing data measured at different space/time scales may alleviate the problem of the sparsity of the data available, it essentially disregards the scale effect of estimation results. The importance of the scale effect must be recognized since a variable displays different physical properties depending on the spatial or temporal scale at which it is observed. In this study we develop a mathematical framework to derive the conditional Probability Density Function (PDF) of a variable at the local scale given an observation of that variable at a larger spatial or temporal scale, which properly models the uncertainty associated with the different observations scales of space/time natural processes. The developed framework allows to efficiently mix data observed at a variety of scales by accounting for data uncertainty associated with each observation scale present, and therefore generates soft data rigorously assimilated in the Bayesian Maximum Entropy (BME) method of modern Geostatistics to increase the mapping accuracy of the map at the scale of interest. We investigate the proposed approach with synthetic case studies involving observations of a space/time process at a variety of temporal and spatial scales. These case studies demonstrate the power of the proposed approach by leading to a set of maps with a noticeable increase of mapping accuracy over classical approaches not accounting for the scale effects. Hence the proposed approach will be useful for a wide variety of

  15. Long-time observation of meteor induced layers with ionosonde

    NASA Astrophysics Data System (ADS)

    Yusupov, Kamil; Akchurin, Adel

    2016-07-01

    It is considered that the main theory explaining appearance of sporadic E is the theory of wind shear, which means (includes) the presence and movement of nodes converging tidal wind through the height region of the most frequent occurrence Es (120-140km) [Mathew et. all, 1998]. However, the appearance of intense layers, following its name, are sporadic, and such variability cannot to explain by the influence of tidal waves only. Another indication inconsistency theory of wind shear is the appearance of so-called transient Es layers [Maruiama, 2003]. The distinctive feature of this trace is the high critical frequency (> 5 MHz), a constant height, weak amplitude, all trace semitransparent and short lifetime [Maruiama et. all, 2003 and 2008 and references there]. Because of duration, such layer is opposite to the traditional persistent Es layer, which we do not consider in this paper. Various researchers have used different terms for such spontaneous Es, it is meteor echo, meteor induced Es, spontaneously formed sporadic Es patches resulting of the Fresnel scattering from a region of enhanced plasma density along the meteor trail, transitory Es and transient Es. Since the term transient Es is unstable, to avoid confusion, we will stick to this term. Since meteor echo is not fully satisfy this term by some parameter, we will describe the properties of transient Es based on the ionogram properties and not from physics of its origin. We used data from our ionosonde with one-minute ionogram repetition rate for 2010-2014 years. For processing performed a method are using to select beatings and the ionosphere reflectivity of the layers by means A-, H-and AΣ-map [Akchurin, 2011; Yusupov, 2014]. This maps allow to collect transient Es appearance over a long-time. Such statistics comparison with meteor showers activity showed good agreement. It shows the presence of the transient Es formation mechanism, which coupling with meteors.

  16. Advanced Earth Observation System Instrumentation Study (aeosis)

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  17. A new method for quantifying and modeling large scale surface water inundation dynamics and key drivers using multiple time series of Earth observation and river flow data. A case study for Australia's Murray-Darling Basin

    NASA Astrophysics Data System (ADS)

    Heimhuber, Valentin; Tulbure, Mirela G.; Broich, Mark

    2017-04-01

    Periodically inundated surface water (SW) areas such as floodplains are hotspots of biodiversity and provide a broad range of ecosystem services but have suffered alarming declines in recent history. Large scale flooding events govern the dynamics of these areas and are a critical component of the terrestrial water cycle, but their propagation through river systems and the corresponding long term SW dynamics remain poorly quantified on continental or global scales. In this research, we used an unprecedented Landsat-based time series of SW maps (1986-2011), to develop statistical inundation models and quantify the role of driver variables across the Murray-Darling Basin (MDB) (1 million square-km), which is Australia's bread basket and subject to competing demands over limited water resources. We fitted generalized additive models (GAM) between SW extent as the dependent variable and river flow data from 68 gauges, spatial time series of rainfall (P; interpolated gauge data), evapotranspiration (ET; AWRA-L land surface model) and soil moisture (SM; active passive microwave satellite remote sensing) as predictor variables. We used a fully directed and connected river network (Australian Geofabric) in combination with ancillary data, to develop a spatial modeling framework consisting of 18,521 individual modeling units. We then fitted individual models for all modeling units, which were made up of 10x10 km grid cells split into floodplain, floodplain-lake and non-floodplain areas, depending on the type of water body and its hydrologic connectivity to a gauged river. We applied the framework to quantify flood propagation times for all major river and floodplain systems across the MDB, which were in good accordance with observed travel times. After incorporating these flow lag times into the models, average goodness of fit was high across floodplains and floodplain-lake modeling units (r-squared > 0.65), which were primarily driven by river flow, and lower for non

  18. 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.

  19. Stability of Teachers' Classroom Instruction across Classes and Time of Observation.

    ERIC Educational Resources Information Center

    Huang, Shwu-yong Liou; Waxman, Hersholt C.

    The stability of teacher behavior has been one of the most important areas of process-product research. This study was designed to investigate teacher stability in the context of math instruction across classes and times of observation in order to assess the relationship between teaching styles and student learning outcomes. Specifically the study…

  20. Stability of Teachers' Classroom Instruction across Classes and Time of Observation.

    ERIC Educational Resources Information Center

    Huang, Shwu-yong Liou; Waxman, Hersholt C.

    The stability of teacher behavior has been one of the most important areas of process-product research. This study was designed to investigate teacher stability in the context of math instruction across classes and times of observation in order to assess the relationship between teaching styles and student learning outcomes. Specifically the study…

  1. The NOAA Satellite Observing System Architecture Study

    NASA Technical Reports Server (NTRS)

    Volz, Stephen; Maier, Mark; Di Pietro, David

    2016-01-01

    NOAA is beginning a study, the NOAA Satellite Observing System Architecture (NSOSA) study, to plan for the future operational environmental satellite system that will follow GOES and JPSS, beginning about 2030. This is an opportunity to design a modern architecture with no pre-conceived notions regarding instruments, platforms, orbits, etc. The NSOSA study will develop and evaluate architecture alternatives to include partner and commercial alternatives that are likely to become available. The objectives will include both functional needs and strategic characteristics (e.g., flexibility, responsiveness, sustainability). Part of this study is the Space Platform Requirements Working Group (SPRWG), which is being commissioned by NESDIS. The SPRWG is charged to assess new or existing user needs and to provide relative priorities for observational needs in the context of the future architecture. SPRWG results will serve as input to the process for new foundational (Level 0 and Level 1) requirements for the next generation of NOAA satellites that follow the GOES-R, JPSS, DSCOVR, Jason-3, and COSMIC-2 missions.

  2. Spectral modulation observed in artificial photosynthetic complexes by real-time vibrational spectroscopy

    NASA Astrophysics Data System (ADS)

    Du, Juan; Yuan, Wei; Xing, Xin; Miyatake, Tomohiro; Tamiaki, Hitoshi; Kobayashi, Takayoshi; Leng, Yuxin

    2017-09-01

    By real-time vibrational spectroscopy using 6.8 fs pulses, real-time vibronic coupling in stair-like zinc chlorin aggregates was studied. Besides the observed fast excitonic relaxation, amplitudes of coherent molecular vibrations are found to be linearly dispersed from the resonant peak as a function of their own vibrational frequencies. In addition, the initial phases of the molecular vibrations exhibiting clear π phase jump have been observed. All these results indicate that coherent vibrations in the artificial chlorosome intermediate energy exchange between the laser fields around the resonant peak and those separated from it by photon energy equal to the vibrational frequencies.

  3. Observability of nonlinear dynamics: Normalized results and a time-series approach

    NASA Astrophysics Data System (ADS)

    Aguirre, Luis A.; Bastos, Saulo B.; Alves, Marcela A.; Letellier, Christophe

    2008-03-01

    This paper investigates the observability of nonlinear dynamical systems. Two difficulties associated with previous studies are dealt with. First, a normalized degree observability is defined. This permits the comparison of different systems, which was not generally possible before. Second, a time-series approach is proposed based on omnidirectional nonlinear correlation functions to rank a set of time series of a system in terms of their potential use to reconstruct the original dynamics without requiring the knowledge of the system equations. The two approaches proposed in this paper and a former method were applied to five benchmark systems and an overall agreement of over 92% was found.

  4. Real-time retrieval of precipitable water vapor from GPS and BeiDou observations

    NASA Astrophysics Data System (ADS)

    Lu, Cuixian; Li, Xingxing; Nilsson, Tobias; Ning, Tong; Heinkelmann, Robert; Ge, Maorong; Glaser, Susanne; Schuh, Harald

    2015-09-01

    The rapid development of the Chinese BeiDou Navigation Satellite System (BDS) brings a promising prospect for the real-time retrieval of zenith tropospheric delays (ZTD) and precipitable water vapor (PWV), which is of great benefit for supporting the time-critical meteorological applications such as nowcasting or severe weather event monitoring. In this study, we develop a real-time ZTD/PWV processing method based on Global Positioning System (GPS) and BDS observations. The performance of ZTD and PWV derived from BDS observations using real-time precise point positioning (PPP) technique is carefully investigated. The contribution of combining BDS and GPS for ZTD/PWV retrieving is evaluated as well. GPS and BDS observations of a half-year period for 40 globally distributed stations from the International GNSS Service Multi-GNSS Experiment and BeiDou Experiment Tracking Network are processed. The results show that the real-time BDS-only ZTD series agree well with the GPS-only ZTD series in general: the RMS values are about 11-16 mm (about 2-3 mm in PWV). Furthermore, the real-time ZTD derived from GPS-only, BDS-only, and GPS/BDS combined solutions are compared with those derived from the Very Long Baseline Interferometry. The comparisons show that the BDS can contribute to real-time meteorological applications, slightly less accurately than GPS. More accurate and reliable water vapor estimates, about 1.3-1.8 mm in PWV, can be obtained if the BDS observations are combined with the GPS observations in the real-time PPP data processing. The PWV comparisons with radiosondes further confirm the performance of BDS-derived real-time PWV and the benefit of adding BDS to standard GPS processing.

  5. Psychotherapy and psychological time: a case study.

    PubMed

    Quiñones, Álvaro; Ceric, Francisco; Ugarte, Carla; De Pascale, Adele

    2017-01-01

    The present study is a comparative case study as part of research on the psychotherapeutic process. This research describes the perception of subjective time in two psychotherapeutic processes, one successful and one unsuccessful. We studied two psychotherapeutic processes of cognitive orientation, which were video recorded and fully transcribed in each session. First a qualitative analysis was applied for quality coding (Top-down) was performed to identify category types of subjective time, depending on psychological well-being. These were categorized as past, present, and future; each one in positive and negative forms. Secondly, two quantitative statistical analyses were applied: one of content analysis, which allowed us to observe the frequencies for the six categories, and another, a cumulative frequency analysis, which allowed us to identify a differential pattern in the analyzed cases. These data showed different temporal profiles for both cases, differentiated by categories. This finding that would allow us to track the process of subjectivity in terms of specific components associated with psychotherapy success. We present a mixed method, a qualitative for initial coding of patient speaking turns and a quantitative methodology such as the cumulative frequency analysis in time in a therapeutic context. Those changes are progressive and must be observed as a continuous and dynamic evolution to allow for an interpretation in a naturalistic context.

  6. 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.

  7. Extending single molecule fluorescence observation time by amplitude-modulated excitation

    NASA Astrophysics Data System (ADS)

    Kisley, Lydia; Chang, Wei-Shun; Cooper, David; Mansur, Andrea P.; Landes, Christy F.

    2013-09-01

    We present a hardware-based method that can improve single molecule fluorophore observation time by up to 1500% and super-localization by 47% for the experimental conditions used. The excitation was modulated using an acousto-optic modulator (AOM) synchronized to the data acquisition and inherent data conversion time of the detector. The observation time and precision in super-localization of four commonly used fluorophores were compared under modulated and traditional continuous excitation, including direct total internal reflectance excitation of Alexa 555 and Cy3, non-radiative Förster resonance energy transfer (FRET) excited Cy5, and direct epi-fluorescence wide field excitation of Rhodamine 6G. The proposed amplitude-modulated excitation does not perturb the chemical makeup of the system or sacrifice signal and is compatible with multiple types of fluorophores. Amplitude-modulated excitation has practical applications for any fluorescent study utilizing an instrumental setup with time-delayed detectors.

  8. An Investigation on the Contribution of GLONASS to the Precise Point Positioning for Short Time Observations

    NASA Astrophysics Data System (ADS)

    Ulug, R.; Ozludemir, M. T.

    2016-12-01

    After 2011, through the modernization process of GLONASS, the number of satellites increased rapidly. This progress has made the GLONASS the only fully operational system alternative to GPS in point positioning. So far, many researches have been conducted to investigate the contribution of GLONASS to point positioning considering different methods such as Real Time Kinematic (RTK) and Precise Point Positioning (PPP). The latter one, PPP, is a method that performs precise position determination using a single GNSS receiver. PPP method has become very attractive since the early 2000s and it provided great advantages for engineering and scientific applications. However, PPP method needs at least 2 hours observation time and the required observation length may be longer depending on several factors, such as the number of satellites, satellite configuration etc. The more satellites, the less observation time. Nevertheless the impact of the number of satellites included must be known very well. In this study, to determine the contribution of GLONASS on PPP, GLONASS satellite observations were added one by one from 1 to 5 satellite in 2, 4 and 6 hours of observations. For this purpose, the data collected at the IGS site ISTA was used. Data processing has been done for Day of Year (DOY) 197 in 2016. 24 hours GPS observations have been processed by Bernese 5.2 PPP module and the output was selected as the reference while 2, 4 and 6 hours GPS and GPS/GLONASS observations have been processed by magic GNSS PPP module. The results clearly showed that GPS/GLONASS observations improved positional accuracy, precision, dilution of precision and convergence to the reference coordinates. In this context, coordinate differences between 24 hours GPS observations and 6 hours GPS/GLONASS observations have been obtained as less than 2 cm.

  9. Observed variations in U.S. frost timing linked to atmospheric circulation patterns

    USGS Publications Warehouse

    Strong, Courtenay; McCabe, Gregory J.

    2017-01-01

    Several studies document lengthening of the frost-free season within the conterminous United States (U.S.) over the past century, and report trends in spring and fall frost timing that could stem from hemispheric warming. In the absence of warming, theory and case studies link anomalous frost timing to atmospheric circulation anomalies. However, recent efforts to relate a century of observed changes in U.S. frost timing to various atmospheric circulations yielded only modest correlations, leaving the relative importance of circulation and warming unclear. Here, we objectively partition the U.S. into four regions and uncover atmospheric circulations that account for 25–48% of spring and fall-frost timing. These circulations appear responsive to historical warming, and they consistently account for more frost timing variability than hemispheric or regional temperature indices. Reliable projections of future variations in growing season length depend on the fidelity of these circulation patterns in global climate models.

  10. Observed variations in U.S. frost timing linked to atmospheric circulation patterns

    NASA Astrophysics Data System (ADS)

    Strong, Courtenay; McCabe, Gregory J.

    2017-05-01

    Several studies document lengthening of the frost-free season within the conterminous United States (U.S.) over the past century, and report trends in spring and fall frost timing that could stem from hemispheric warming. In the absence of warming, theory and case studies link anomalous frost timing to atmospheric circulation anomalies. However, recent efforts to relate a century of observed changes in U.S. frost timing to various atmospheric circulations yielded only modest correlations, leaving the relative importance of circulation and warming unclear. Here, we objectively partition the U.S. into four regions and uncover atmospheric circulations that account for 25-48% of spring and fall-frost timing. These circulations appear responsive to historical warming, and they consistently account for more frost timing variability than hemispheric or regional temperature indices. Reliable projections of future variations in growing season length depend on the fidelity of these circulation patterns in global climate models.

  11. Murchison Widefield Array Observations of Anomalous Variability: A Serendipitous Night-time Detection of Interplanetary Scintillation

    NASA Astrophysics Data System (ADS)

    Kaplan, D. L.; Tingay, S. J.; Manoharan, P. K.; Macquart, J. P.; Hancock, P.; Morgan, J.; Mitchell, D. A.; Ekers, R. D.; Wayth, R. B.; Trott, C.; Murphy, T.; Oberoi, D.; Cairns, I. H.; Feng, L.; Kudryavtseva, N.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Deshpande, A. A.; Gaensler, B. M.; Greenhill, L. J.; Hurley Walker, N.; Hazelton, B. J.; Johnston Hollitt, M.; Lonsdale, C. J.; McWhirter, S. R.; Morales, M. F.; Morgan, E.; Ord, S. M.; Prabu, T.; Udaya Shankar, N.; Srivani, K. S.; Subrahmanyan, R.; Webster, R. L.; Williams, A.; Williams, C. L.

    2015-08-01

    We present observations of high-amplitude rapid (2 s) variability toward two bright, compact extragalactic radio sources out of several hundred of the brightest radio sources in one of the 30^\\circ × 30^\\circ Murchison Widefield Array (MWA) Epoch of Reionization fields using the MWA at 155 MHz. After rejecting intrinsic, instrumental, and ionospheric origins we consider the most likely explanation for this variability to be interplanetary scintillation (IPS), likely the result of a large coronal mass ejection propagating from the Sun. This is confirmed by roughly contemporaneous observations with the Ooty Radio Telescope. We see evidence for structure on spatial scales ranging from <1000 to \\gt {10}6 km. The serendipitous night-time nature of these detections illustrates the new regime that the MWA has opened for IPS studies with sensitive night-time, wide-field, low-frequency observations. This regime complements traditional dedicated strategies for observing IPS and can be utilized in real-time to facilitate dedicated follow-up observations. At the same time, it allows large-scale surveys for compact (arcsec) structures in low-frequency radio sources despite the 2\\prime resolution of the array.

  12. Time Resolved Studies Of Adsorbed Species

    NASA Astrophysics Data System (ADS)

    Howard, J.; Nicol, J. M.

    1985-12-01

    A time-resolved Fourier transform IR study of ethyne adsorbed on ZnNaA zeolite yields results very different from those reported for related systems. Initially two species (A and B) are formed by the interaction of C2H2 with the cations. Whereas species A (π-bonded C2H2) was found to be removed immediately on evacuation, species B (probably Zn-acetylide) was not fully removed after 60 mins evacuation. In the presence of the gas phase, bands due to Species A decreased slowly in intensity as new bands due to adsorbed ethanal were observed.

  13. Observations and predictions of eclipse times by astronomers in the pre-telescopic period.

    NASA Astrophysics Data System (ADS)

    Steele, J. M.

    Eclipses of the Sun and Moon are among the most impressive of celestial events. It is therefore unsurprising that they have played an important role in the astronomy and astrology of most early cultures. Many hundreds of references to eclipses are found in the writings of the chroniclers and astronomers of the pre-telescopic world. In particular, the astronomers of Babylon, Ancient Greece, the Islamic Near East. Later Medieval and Renaissance Europe, China, and Japan, recorded a large number of observations and predictions of the time of an eclipse. The present study contains an extensive compilation of all known timed reports of eclipse observations and predictions made by astronomers in the pre-telescopic period. By performing a basic analysis of the recorded times, it has been possible to trace the gradual development of the techniques used by the astronomers to observe and predict eclipses. In order to conduct this analysis, it has been necessary to investigate a number of other problems including the dating of damaged observational accounts, the units of time used by the early astronomers, and the methods by which the Babylonians predicted eclipses. Many of these questions have not previously been answered. Therefore, the results of this study provide important information regarding the astronomies of these early cultures.

  14. 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.

  15. Apollo 15 time and motion study

    NASA Technical Reports Server (NTRS)

    Kubis, J. F.; Elrod, J. T.; Rusnak, R.; Barnes, J. E.

    1972-01-01

    A time and motion study of Apollo 15 lunar surface activity led to examination of four distinct areas of crewmen activity. These areas are: an analysis of lunar mobility, a comparative analysis of tasks performed in 1-g training and lunar EVA, an analysis of the metabolic cost of two activities that are performed in several EVAs, and a fall/near-fall analysis. An analysis of mobility showed that the crewmen used three basic mobility patterns (modified walk, hop, side step) while on the lunar surface. These mobility patterns were utilized as adaptive modes to compensate for the uneven terrain and varied soil conditions that the crewmen encountered. A comparison of the time required to perform tasks at the final 1-g lunar EVA training sessions and the time required to perform the same task on the lunar surface indicates that, in almost all cases, it took significantly more time (on the order of 40%) to perform tasks on the moon. This increased time was observed even after extraneous factors (e.g., hardware difficulties) were factored out.

  16. Using Momentary Time Sampling to Estimate Minutes of Physical Activity in Physical Education: Validation of Scores for the System for Observing Fitness Instruction Time

    ERIC Educational Resources Information Center

    Heath, Edward M.; Coleman, Karen J.; Lensegrav, Tera L.; Fallon, Jennifer A.

    2006-01-01

    The System for Observing Fitness Instruction Time (SOFIT) is a direct observation system specifically developed for use during physical education (PE; McKenzie, 1991; McKenzie, Sallis, & Nader, 1991). The purpose of this study was to validate the estimates of time spent in various physical activity intensities obtained with the paper and pencil…

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

    NASA Technical Reports Server (NTRS)

    London, Julius

    1990-01-01

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

  18. Using non-specialist observers in 4AFC human observer studies

    NASA Astrophysics Data System (ADS)

    Elangovan, Premkumar; Mackenzie, Alistair; Dance, David R.; Young, Kenneth C.; Wells, Kevin

    2017-03-01

    Virtual clinical trials (VCTs) are an emergent approach for rapid evaluation and comparison of various breast imaging technologies and techniques using computer-based modeling tools. Increasingly 4AFC (Four alternative forced choice) virtual clinical trials are used to compare detection performances of different breast imaging modalities. Most prior studies have used physicists and/or radiologists and physicists interchangeably. However, large scale use of statistically significant 4AFC observer studies is challenged by the individual time commitment and cost of such observers, often drawn from a limited local pool of specialists. This work aims to investigate whether non-specialist observers can be used to supplement such studies. A team of five specialist observers (medical physicists) and five non-specialists participated in a 4AFC study containing simulated 2D-mammography and DBT (digital breast tomosynthesis) images, produced using the OPTIMAM toolbox for VCTs. The images contained 4mm irregular solid masses and 4mm spherical targets at a range of contrast levels embedded in a realistic breast phantom background. There was no statistically significant difference between the detection performance of medical physicists and non-specialists (p>0.05). However, non-specialists took longer to complete the study than their physicist counterparts, which was statistically significant (p<0.05). Overall, the results from both observer groups indicate that DBT has a lower detectable threshold contrast than 2D-mammography for both masses and spheres, and both groups found spheres easier to detect than irregular solid masses.

  19. Relating observability and compressed sensing of time-varying signals in recurrent linear networks.

    PubMed

    Kafashan, MohammadMehdi; Nandi, Anirban; Ching, ShiNung

    2016-11-01

    In this paper, we study how the dynamics of recurrent networks, formulated as general dynamical systems, mediate the recovery of sparse, time-varying signals. Our formulation resembles the well-described problem of compressed sensing, but in a dynamic setting. We specifically consider the problem of recovering a high-dimensional network input, over time, from observation of only a subset of the network states (i.e., the network output). Our goal is to ascertain how the network dynamics may enable recovery, even if classical methods fail at each time instant. We are particularly interested in understanding performance in scenarios where both the input and output are corrupted by disturbance and noise, respectively. Our main results consist of the development of analytical conditions, including a generalized observability criterion, that ensure exact and stable input recovery in a dynamic, recurrent network setting. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Observing Expertise-Related Actions Leads to Perfect Time Flow Estimations

    PubMed Central

    Chen, Yin-Hua; Pizzolato, Fabio; Cesari, Paola

    2013-01-01

    The estimation of the time of exposure of a picture portraying an action increases as a function of the amount of movement implied in the action represented. This effect suggests that the perceiver creates an internal embodiment of the action observed as if internally simulating the entire movement sequence. Little is known however about the timing accuracy of these internal action simulations, specifically whether they are affected by the level of familiarity and experience that the observer has of the action. In this study we asked professional pianists to reproduce different durations of exposure (shorter or longer than one second) of visual displays both specific (a hand in piano-playing action) and non-specific to their domain of expertise (a hand in finger-thumb opposition and scrambled-pixels) and compared their performance with non-pianists. Pianists outperformed non-pianists independently of the time of exposure of the stimuli; remarkably the group difference was particularly magnified by the pianists’ enhanced accuracy and stability only when observing the hand in the act of playing the piano. These results for the first time provide evidence that through musical training, pianists create a selective and self-determined dynamic internal representation of an observed movement that allows them to estimate precisely its temporal duration. PMID:23405131

  1. High Time Resolution Lightning Mapping Lightning Mapping Observations of a Small Thunderstorm during STEPS

    NASA Astrophysics Data System (ADS)

    Rison, W.; Krehbiel, P.; Thomas, R.; Hamlin, T.; Harlin, J.

    2001-12-01

    During the 2000 STEPS (Severe Thunderstorm Electrification and Precipitation Study) program, the New Mexico Tech Lightning Mapping Array (LMA) was operated in high time resolution mode [Rison et al., 2000] for several days. On July 11 a small thunderstorm formed over the northern part of the LMA network while the LMA was in this mode. The lightning mapping observations show that the electrical structure of the thunderstorm changed significantly during its lifetime. The electrical development of the storm as inferred from the lightning mapping observations will be presented. In high time resolution mode the LMA records the time of the strongest VHF radiation received in 10 μ s windows (compared to 100~μ s windows in normal time resolution mode). In high time resolution mode the LMA can produce significantly more detailed images of continuous radiation processes (such as stepped leaders, dart leaders and K-changes). Cloud-to-ground discharges examined in the July 11 storm show significant branching in stepped leaders, and there is sufficient detail in stepped and dart leaders and K-changes that good velocities for relatively fast leader processes (107 m/s) can be determined. [1ex] Rison, W., P. Krehbiel, R. Thomas, T. Hamlin, and J. Harlin, A Time-of-Arrival Lightning Mapping System with High Time Resolution, Abstract A52C-01, Fall Ann. Mtg. Amer. Geophys. Union, EOS, 81, p. F47, 2000.

  2. 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

  3. Recurrent first hitting times in Wiener diffusion under several observation schemes.

    PubMed

    Whitmore, G A; Ramsay, T; Aaron, S D

    2012-04-01

    Recurrent events are commonly encountered in the natural sciences, engineering, and medicine. The theory of renewal and regenerative processes provides an elegant mathematical foundation for idealized recurrent event processes. In real-world applications, however, the contexts tend to be complicated by a variety of practical intricacies, including observation schemes with different phase and data structures. This paper formulates a recurrent event process as a succession of independent and identically distributed first hitting times for a Wiener sample path as it passes through successive equally-spaced levels. We develop exact mathematical results for statistical inferences based on several observation schemes that include observation initiated at a renewal point, observation of a stationary process over a finite window, and other variants. We also consider inferences drawn from different data structures, including gap times between renewal points (or fragments thereof) and counts of renewal events occurring within an observation window. We explore the precision of estimates using simulated scenarios and develop empirical regression functions for planning the sample size of a recurrent event study. We demonstrate our results using data from a clinical trial for chronic obstructive pulmonary disease in which the recurrent events are successive exacerbations of the condition. The case study demonstrates how covariates can be incorporated into the analysis using threshold regression.

  4. [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

    2008-01-01

    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 websites 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.

  5. 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.

  6. Do Our Engineering Students Spend Enough Time Studying?

    ERIC Educational Resources Information Center

    Kolari, S.; Savander-Ranne, C.; Viskari, E.-L.

    2006-01-01

    In higher education one of the most important learning goals is deep understanding. Achieving this goal needs time and effort. The authors discuss their observations of student time use on the basis of several case studies which they have conducted in the field of engineering education in Finland. The time that the students spend studying is…

  7. Studying evolved stars with Herschel observations

    NASA Astrophysics Data System (ADS)

    da Silva Santos, João Manuel

    2016-07-01

    A systematic inspection of the far-infrared (FIR) properties of evolved stars allows not only to constrain physical models, but also to understand the chemical evolution that takes place in the end of their lives. In this work we intend to study the circumstellar envelopes (CSE) on a sample of stars in the THROES catalogue from AGB/post-AGB stars to planetary nebulae using photometry and spectroscopy provided by the PACS instrument on-board Herschel telescope. In the first part we are interested in obtaining an estimate of the size of FIR emitting region and to sort our targets in two classes: point-like and extended. Secondly, we focus on the molecular component of the envelope traced by carbon monoxide (CO) rotational lines. We conduct a line survey on a sample of evolved stars by identifying and measuring flux of both 12CO and 13CO isotopologues in the PACS range, while looking at the overall properties of the sample. Lastly, we will be interested in obtaining physical parameters of the CSE, namely gas temperature, mass and mass-loss rate on a sample of carbon stars. For that, we make use of PACS large wavelength coverage, which enables the simultaneous study of a large number of CO transitions, to perform the rotational diagram analysis. We report the detection of CO emission in a high number of stars from the catalogue, which were mostly classified as point-like targets with a few exceptions of planetary nebulae. High J rotational number transitions were detected in a number of targets, revealing the presence of a significant amount of hot gas (T ˜ 400-900 K) and high mass-loss rates. We conclude that Herschel/PACS is in a privileged position to detect a new population of warmer gas, typically missed in sub-mm/mm observations.

  8. Participant Observer Study, September 1974-June 1975.

    ERIC Educational Resources Information Center

    Millonzi, Joel C.; And Others

    LaGuardia Community College (New York) provides secondary education through its Middle College program, which includes comprehensive remedial programs for low ability students. During the 1974-75 academic year, two participant observers made over 400 observations of the Middle College's activities, focusing on: (1) instructional methods,…

  9. Observing the dynamics of supermassive black hole binaries with pulsar timing arrays.

    PubMed

    Mingarelli, C M F; Grover, K; Sidery, T; Smith, R J E; Vecchio, A

    2012-08-24

    Pulsar timing arrays are a prime tool to study unexplored astrophysical regimes with gravitational waves. Here, we show that the detection of gravitational radiation from individually resolvable supermassive black hole binary systems can yield direct information about the masses and spins of the black holes, provided that the gravitational-wave-induced timing fluctuations both at the pulsar and at Earth are detected. This in turn provides a map of the nonlinear dynamics of the gravitational field and a new avenue to tackle open problems in astrophysics connected to the formation and evolution of supermassive black holes. We discuss the potential, the challenges, and the limitations of these observations.

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

    NASA Technical Reports Server (NTRS)

    Ackerman, Steven A.; Inoue, Toshiro

    1994-01-01

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

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

    SciTech Connect

    Ackerman, S.A.; Inoue, Toshiro

    1994-03-01

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

  12. Probability distributions of molecular observables computed from Markov models. II. Uncertainties in observables and their time-evolution

    NASA Astrophysics Data System (ADS)

    Chodera, John D.; Noé, Frank

    2010-09-01

    Discrete-state Markov (or master equation) models provide a useful simplified representation for characterizing the long-time statistical evolution of biomolecules in a manner that allows direct comparison with experiments as well as the elucidation of mechanistic pathways for an inherently stochastic process. A vital part of meaningful comparison with experiment is the characterization of the statistical uncertainty in the predicted experimental measurement, which may take the form of an equilibrium measurement of some spectroscopic signal, the time-evolution of this signal following a perturbation, or the observation of some statistic (such as the correlation function) of the equilibrium dynamics of a single molecule. Without meaningful error bars (which arise from both approximation and statistical error), there is no way to determine whether the deviations between model and experiment are statistically meaningful. Previous work has demonstrated that a Bayesian method that enforces microscopic reversibility can be used to characterize the statistical component of correlated uncertainties in state-to-state transition probabilities (and functions thereof) for a model inferred from molecular simulation data. Here, we extend this approach to include the uncertainty in observables that are functions of molecular conformation (such as surrogate spectroscopic signals) characterizing each state, permitting the full statistical uncertainty in computed spectroscopic experiments to be assessed. We test the approach in a simple model system to demonstrate that the computed uncertainties provide a useful indicator of statistical variation, and then apply it to the computation of the fluorescence autocorrelation function measured for a dye-labeled peptide previously studied by both experiment and simulation.

  13. 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

  14. 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.

  15. Response to Dr. Pashby: Time operators and POVM observables in quantum mechanics

    NASA Astrophysics Data System (ADS)

    Fleming, Gordon N.

    2015-11-01

    I argue against a general time observable in quantum mechanics except for quantum gravity theory. Then I argue in support of case specific arrival, dwell and relative time observables with a cautionary note concerning the broad approach to POVM observables because of the wild proliferation available.

  16. Correcting for the solar wind in pulsar timing observations: the role of simultaneous and low-frequency observations

    NASA Astrophysics Data System (ADS)

    Niu, Ze-Xi; Hobbs, George; Wang, Jing-Bo; Dai, Shi

    2017-09-01

    The primary goal of pulsar timing array projects is to detect ultra-low-frequency gravitational waves. Pulsar data sets are affected by numerous noise processes including varying dispersive delays in the interstellar medium and from the solar wind. The solar wind can lead to rapidly changing variations that, with existing telescopes, can be hard to measure and then remove. In this paper we study the possibility of using a low frequency telescope to aid in such correction for the Parkes Pulsar Timing Array (PPTA) and also discuss whether the ultra-wide-bandwidth receiver for the FAST telescope is sufficient to model solar wind variations. Our key result is that a single wide-bandwidth receiver can be used to model and remove the effect of the solar wind. However, for pulsars that pass close to the Sun such as PSR J1022 + 1022, the solar wind is so variable that observations at two telescopes separated by a day are insufficient to correct the solar wind effect.

  17. Dependability of data derived from time sampling methods with multiple observation targets.

    PubMed

    Johnson, Austin H; Chafouleas, Sandra M; Briesch, Amy M

    2017-03-01

    In this study, generalizability theory was used to examine the extent to which (a) time-sampling methodology, (b) number of simultaneous behavior targets, and (c) individual raters influenced variance in ratings of academic engagement for an elementary-aged student. Ten graduate-student raters, with an average of 7.20 hr of previous training in systematic direct observation and 58.20 hr of previous direct observation experience, scored 6 videos of student behavior using 12 different time-sampling protocols. Five videos were submitted for analysis, and results for observations using momentary time-sampling and whole-interval recording suggested that the majority of variance was attributable to the rating occasion, although results for partial-interval recording generally demonstrated large residual components comparable with those seen in prior research. Dependability coefficients were above .80 when averaging across 1 to 2 raters using momentary time-sampling, and 2 to 3 raters using whole-interval recording. Ratings derived from partial-interval recording needed to be averaged over 3 to 7 raters to demonstrate dependability coefficients above .80. (PsycINFO Database Record

  18. National study of emergency department observation services.

    PubMed

    Wiler, Jennifer L; Ross, Michael A; Ginde, Adit A

    2011-09-01

    The objective was to describe patient and facility characteristics of emergency department (ED) observation services in the United States. The authors analyzed the 2007 National Hospital Ambulatory Medical Care Survey (NHAMCS). Characteristics of EDs with observation units (OUs) were compared to those without, and patients with a disposition of ED observation were compared to those with a "short-stay" (<48 hour) hospital admission. Results are descriptive and without formal statistical comparisons for this observational analysis. An estimated 1,746 U.S. EDs (36%) reported having OUs, of which 56% are administratively managed by ED staff. Fifty-two percent of hospitals with ED-managed OUs are in an urban location, and 89% report ED boarding, compared to 29 and 65% of those that do not have an OU. The admission rate is 38% at those with ED-managed OUs and 15% at those without OUs. Of the 15.1% of all ED patients who are kept in the hospital following an ED visit, one-quarter are kept for either a short-stay admission (1.8%) or an ED observation admission (2.1%). Most (82%) ED observation patients were discharged from the ED. ED observation patients were similar to short-stay admission patients in terms of age (median = 52 years for both, interquartile range = 36 to 70 years), self-pay (12% vs. 10%), ambulance arrival (37% vs. 36%), urgent/emergent triage acuity (77% vs. 74%), use of ≥1 ED medication (64% vs.76%), and the most common primary chief complaints and primary diagnoses. Over one-third of U.S. EDs have an OU. Short-stay admission patients have similar characteristics as ED observation patients and may represent an opportunity for the growth of OUs. © 2011 by the Society for Academic Emergency Medicine.

  19. Time-resolved High Spectral Resolution Observation of 2MASSW J0746425+200032AB

    NASA Astrophysics Data System (ADS)

    Wang, Ji; Prato, Lisa; Mawet, Dimitri

    2017-03-01

    Many brown dwarfs (BDs) exhibit photometric variability at levels from tenths to tens of percents. The photometric variability is related to magnetic activity or patchy cloud coverage, characteristic of BDs near the L–T transition. Time-resolved spectral monitoring of BDs provides diagnostics of cloud distribution and condensate properties. However, current time-resolved spectral studies of BDs are limited to low spectral resolution (R ∼ 100) with the exception of the study of Luhman 16 AB at a resolution of 100,000 using the VLT+CRIRES. This work yielded the first map of BD surface inhomogeneity, highlighting the importance and unique contribution of high spectral resolution observations. Here, we report on the time-resolved high spectral resolution observations of a nearby BD binary, 2MASSW J0746425+200032AB. We find no coherent spectral variability that is modulated with rotation. Based on simulations, we conclude that the coverage of a single spot on 2MASSW J0746425+200032AB is smaller than 1% or 6.25% if spot contrast is 50% or 80% of its surrounding flux, respectively. Future high spectral resolution observations aided by adaptive optics systems can put tighter constraints on the spectral variability of 2MASSW J0746425+200032AB and other nearby BDs.

  20. ERP-Variations on Time Scales Between Hours and Months Derived From GNSS Observations

    NASA Astrophysics Data System (ADS)

    Weber, R.; Englich, S.; Mendes Cerveira, P.

    2007-05-01

    Current observations gained by the space geodetic techniques, especially VLBI, GPS and SLR, allow for the determination of Earth Rotation Parameters (ERPs - polar motion, UT1/LOD) with unprecedented accuracy and temporal resolution. This presentation focuses on contributions to the ERP recovery provided by satellite navigation systems (primarily GPS). The IGS (International GNSS Service), for example, currently provides daily polar motion with an accuracy of less than 0.1mas and LOD estimates with an accuracy of a few microseconds. To study more rapid variations in polar motion and LOD we established in a first step a high resolution (hourly resolution) ERP-time series from GPS observation data of the IGS network covering the year 2005. The calculations were carried out by means of the Bernese GPS Software V5.0 considering observations from a subset of 113 fairly stable stations out of the IGS05 reference frame sites. From these ERP time series the amplitudes of the major diurnal and semidiurnal variations caused by ocean tides are estimated. After correcting the series for ocean tides the remaining geodetic observed excitation is compared with variations of atmospheric excitation (AAM). To study the sensitivity of the estimates with respect to the applied mapping function we applied both the widely used NMF (Niell Mapping Function) and the VMF1 (Vienna Mapping Function 1). In addition, based on computations covering two months in 2005, the potential improvement due to the use of additional GLONASS data will be discussed.

  1. The feasibility and applications of non-invasive cardiac output monitoring, thromboelastography and transit-time flow measurement in living-related renal transplantation surgery: results of a prospective pilot observational study

    PubMed Central

    2014-01-01

    Introduction Delayed graft function (DGF) remains a significant and detrimental postoperative phenomenon following living-related renal allograft transplantation, with a published incidence of up to 15%. Early therapeutic vasodilatory interventions have been shown to improve DGF, and modifications to immunosuppressive regimens may subsequently lessen its impact. This pilot study assesses the potential applicability of perioperative non-invasive cardiac output monitoring (NICOM), transit-time flow monitoring (TTFM) of the transplant renal artery and pre-/perioperative thromboelastography (TEG) in the early prediction of DGF and perioperative complications. Methods Ten consecutive living-related renal allograft recipients were studied. Non-invasive cardiac output monitoring commenced immediately following induction of anaesthesia and was maintained throughout the perioperative period. Doppler-based TTFM was performed during natural haemostatic pauses in the transplant surgery: immediately following graft reperfusion and following ureteric implantation. Central venous blood sampling for TEG was performed following induction of anaesthesia and during abdominal closure. Results A single incidence of DGF was seen within the studied cohort and one intra-operative (thrombotic) complication noted. NICOM confirmed a predictable trend of increased cardiac index (CI) following allograft reperfusion (mean CI - clamped: 3.17 ± 0.29 L/min/m2, post-reperfusion: 3.50 ± 0.35 L/min/m2; P < 0.05) mediated by a significant reduction in total peripheral resistance. Reduced TTFM at the point of allograft reperfusion (227 ml/min c.f. mean; 411 ml/min (95% CI: 358 to 465)) was identified in a subject who experienced intra-operative transplant renal artery thrombosis. TEG data exhibited significant reductions in clot lysis (LY30 (%): pre-op: 1.0 (0.29 to 1.71), post reperfusion 0.33 (0.15 to 0.80); P = 0.02) and a trend towards increased clot initiation following

  2. A content analysis of emotional concerns expressed at the time of receiving a cancer diagnosis: An observational study of consultations with adolescent and young adult patients and their family members.

    PubMed

    Korsvold, Live; Mellblom, Anneli Viktoria; Finset, Arnstein; Ruud, Ellen; Lie, Hanne Cathrine

    2017-02-01

    Little is known about the emotional concerns expressed by adolescent and young adult (AYA) patients in consultations when a diagnosis of cancer is delivered. Here, we investigated the content of such concerns and how health care providers respond to them. We audio-recorded nine consultations with AYA cancer patients (ages: 12-25 years) at the time of diagnosis. We have previously identified and coded 135 emotional concerns and the responses to these in the nine consultations using the Verona Coding Definitions of Emotional Sequences (VR-CoDES) framework. Here, we used qualitative content analysis to study these emotional concerns and categorize them according to overarching themes. We then quantitatively explored associations between the themes of the concerns and whether the responses to them varied according to their themes. We identified four themes for the content of concerns: "Side-effects/late-effects" (39%), "What happens in the near future/practical aspects" (16%), "Fear" (27%) and "Sadness" (17%) (e. g. crying, sighing or other sounds that expressed sadness). Health care providers' responses did not appear to vary according to the different themes of concerns, but typically consisted of providing medical information. The content analysis revealed that patients and family members expressed a wide range of emotional concerns. Health care providers tended to respond to the content-aspect of the concerns, but did rarely explicitly acknowledge the affective-aspect of the concerns. The effect of responses to patients' emotional concerns in the important first consultations about the cancer diagnosis and planned treatment should be investigated in future studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Reconciliation of Waiting Time Statistics of Solar Flares Observed in Hard X-rays

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.; McTiernan, James M.

    2010-07-01

    We study the waiting time distributions of solar flares observed in hard X-rays with ISEE-3/ICE, HXRBS/SMM, WATCH/GRANAT, BATSE/CGRO, and RHESSI. Although discordant results and interpretations have been published earlier, based on relatively small ranges (<2 decades) of waiting times, we find that all observed distributions, spanning over 6 decades of waiting times (Δt ≈ 10-3-103 hr), can be reconciled with a single distribution function, N(Δt) vprop λ0(1 + λ0Δt)-2, which has a power-law slope of p ≈ 2.0 at large waiting times (Δt ≈ 1-1000 hr) and flattens out at short waiting times Δt <~ Δt 0 = 1/λ0. We find a consistent breakpoint at Δt 0 = 1/λ0 = 0.80 ± 0.14 hr from the WATCH, HXRBS, BATSE, and RHESSI data. The distribution of waiting times is invariant for sampling with different flux thresholds, while the mean waiting time scales reciprocically with the number of detected events, Δt 0 vprop 1/n det. This waiting time distribution can be modeled with a nonstationary Poisson process with a flare rate λ = 1/Δt that varies as f(λ) vprop λ-1exp - (λ/λ0). This flare rate distribution requires a highly intermittent flare productivity in short clusters with high rates, separated by relatively long quiescent intervals with very low flare rates.

  4. [Therapeutic failure in scabies: An observational study].

    PubMed

    De Sainte Marie, B; Mallet, S; Gaudy-Marqueste, C; Baumstarck, K; Bentaleb, N; Loundou, A; Hesse, S; Monestier, S; Grob, J-J; Richard, M-A

    2016-01-01

    Several sources suggest an escalation of scabies in France. To describe a population of patients continuing to present with scabies despite multiple treatments in order to identify factors associated with persistence of infection. A descriptive cross-sectional study in adults and children consulting for persistent scabies despite at least one previous treatment. A standardized questionnaire explored potential sources of treatment failure. Thirty-one patients were analyzed. Initial symptoms were noted to have started between two and 52 weeks earlier (mean: 19 weeks). The mean number of prior consultations with a general practitioner was 3.1 (0-10) and 1.7 with a dermatologist (0-7). The mean number of patients per household was 3.5 (1-9). At least one dose of oral ivermectin (maximum of 6 doses per household) was prescribed for 84 % of patients (29 % of whom were not fasted at the time). Further, 74 % of patients received at least one local application of esdepallethrin and piperonyl butoxide (maximum: 5 courses), four received benzyl benzoate and two received permethrin; however, 58 % did not reapply the substance after hand washing. All households bought the prescribed treatments despite the costs. Close contacts of patients were treated in 58 % of households. Decontamination of bedding and clothing was carried out properly in 90 % of households. Persistence of infection appears to be linked to: (1) insufficient treatment of close contacts; (2) absence of a second treatment between days 7 and 14; (3) insufficient efficacy of the available treatments, doubtless due to multiple factors (intrinsic resistance of Sarcoptes, failure to repeat treatment, poor explanation of methods for dosing and application, and oral intake of treatments). Access to non-reimbursed treatments was not identified as a problem and decontamination of bedding and clothing was correctly performed in most cases. Though certain fundamental aspects of scabies treatment must be better

  5. Studies of Accreting Neutron Stars with RXTE Cycle 4 Observations: III: TOO Observations of Atoll Sources

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    2002-01-01

    NASA Grant NAG 5-9244 provided funds for the research projects 'ASM-Triggered TOO Observations of Kilohertz Oscillations in Five Atoll Sources' and 'Further Measurements of the Kilohertz Oscillations in 4U 1705-44' approved under the Rossi X-ray Timing Explorer (RXTE) Guest Observer Program Cycle 4 and funded under the 1999 NASA Astrophysics Data Program. The principal investigator of the observing time proposals was Dr. E. C. Ford (U. of Amsterdam). The grant was funded for one year beginning 3/15/2000. The original ADP proposal was submitted by Prof. Jan van Paradijs, who passed away in 1999 before the funds were distributed. Prof. Wilham S. Padesas administered the grant during the period of performance. In spite of a wealth of observational data on the kHz QPO in low-mass X-ray binaries (LMXBs), the interpretation of this phenomenon is currently uncertain because the pairs of kHz QPO peaks and the oscillations seen in some Type I X-ray bursts are almost, but not quite, connected by a simple beat frequency relation. Further systematic studies of systems with known QPOs are required in order to better understand the phenomenon. The proposals were intended to contribute to a solution to this confusion by observing the sources as they vary over a wide range of X-ray flux. RXTE target-of-opportunity observations of six transient atoll sources, 4U 0614+09, KS 1732-260, Ser X-1, 4U 1702-42, 4U 1820-30 and 4U 1705-44 were to be performed at various flux levels based on ASM measurements.

  6. Studies of Accreting Neutron Stars with RXTE Cycle 4 Observations: III: TOO Observations of Atoll Sources

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    2002-01-01

    NASA Grant NAG 5-9244 provided funds for the research projects 'ASM-Triggered TOO Observations of Kilohertz Oscillations in Five Atoll Sources' and 'Further Measurements of the Kilohertz Oscillations in 4U 1705-44' approved under the Rossi X-ray Timing Explorer (RXTE) Guest Observer Program Cycle 4 and funded under the 1999 NASA Astrophysics Data Program. The principal investigator of the observing time proposals was Dr. E. C. Ford (U. of Amsterdam). The grant was funded for one year beginning 3/15/2000. The original ADP proposal was submitted by Prof. Jan van Paradijs, who passed away in 1999 before the funds were distributed. Prof. Wilham S. Padesas administered the grant during the period of performance. In spite of a wealth of observational data on the kHz QPO in low-mass X-ray binaries (LMXBs), the interpretation of this phenomenon is currently uncertain because the pairs of kHz QPO peaks and the oscillations seen in some Type I X-ray bursts are almost, but not quite, connected by a simple beat frequency relation. Further systematic studies of systems with known QPOs are required in order to better understand the phenomenon. The proposals were intended to contribute to a solution to this confusion by observing the sources as they vary over a wide range of X-ray flux. RXTE target-of-opportunity observations of six transient atoll sources, 4U 0614+09, KS 1732-260, Ser X-1, 4U 1702-42, 4U 1820-30 and 4U 1705-44 were to be performed at various flux levels based on ASM measurements.

  7. Response times across the visual field: empirical observations and application to threshold determination.

    PubMed

    McKendrick, Allison M; Denniss, Jonathan; Turpin, Andrew

    2014-08-01

    This study aimed to determine if response times gathered during perimetry can be exploited within a thresholding algorithm to improve the speed and accuracy of the test. Frequency of seeing (FoS) curves were measured at 24 locations across the central 30° of the visual field of 10 subjects using a Method of Constant Stimuli, with response times recorded for each presentation. Spatial locations were interleaved, and built up over multiple 5-min blocks, in order to mimic the attentional conditions of clinical perimetry. FoS curves were fitted to each participant's data for each location, and response times derived as a function of distance-from-threshold normalised to the slope of each FoS curve. This data was then used to derive a function for the probability of observing response times given the distance-from-threshold, and to seed simulations of a new test procedure (BURTO) that exploited the probability function for stimulus placement. Test time and error were then simulated for patients with various false response rates. When compared with a ZEST algorithm, simulations revealed that BURTO was about one presentation per location faster than ZEST, on average, while sacrificing less precision and bias in threshold estimates than simply terminating the ZEST earlier. Despite response times varying considerably for a given individual and their thresholds, response times can be exploited to reduce the number of presentations required in a visual field test without loss of accuracy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Time trends of cancer incidence in childhood in Campania region: 25 years of observation.

    PubMed

    Indolfi, Paolo; Picazio, Serena; Perrotta, Silverio; Rossi, Francesca; Pession, Andrea; Di Martino, Martina; Pota, Elvira; Di Pinto, Daniela; Indolfi, Cristiana; Rondelli, Roberto; Vetrano, Francesco; Casale, Fiorina

    2016-09-06

    Childhood cancer is relatively uncommon and the European age-standardized rate was 164 new case per million per year among children 0 to 14 years of age (95 % CI 158-170). Aims of our study are to evaluate the cases of these malignant diseases observed between 0 and 15 years of age in the Campania region between 1990 and 2014, the ration between observed and expected cases by disease and province of residence. Also we studied the percentage of extra-regional migration over the time by disease and province of residence. In this study we reported the patients with malignant disease observed in 25 years (1990-2014) based on the specialized registry, the Mod. 1.01 of the AIEOP (Association Italian Pediatric Hematology-Oncology). The size of the monitored population also allowed us to systematically examine five time trends: 1990-94: 1995-99; 2000-04; 2005-09; and 2010-14. Between 1990 and 2014 a total of 3655 malignant neoplasms were reported: Napoli province (2059 cases), Salerno province (625), Caserta province (589), Avellino province (229), and Benevento province (153). Epidemiological data suggested that about 4100 cases could be expected in Campania region during the same period. The overall ratio between observed (O) and expected (E) numbers of cases in the five periods considered rose gradually from 0.69 in the first period to 0.76, then 0.82, 0.91, and 0.94, in the other periods considered. The extra-regional migration involved 1029 cases (28.1 %), showing a reduction from 33.7 % of the first period to 20.3 % of the last period considered. Considering single province of residence we observed the lowest rate of migration in Napoli and Caserta province, whereas higher levels were observed in the other provinces. For all provinces, except Salerno, the extra-regional migration declined significantly over time. The present findings showed an increase over time of O/E ratio, probably due to improvement in the organization of centers and greater trust of families in

  9. 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.

  10. Exploiting crowdsourced observations: High-resolution mapping of real-time urban air quality throughout Europe

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Castell, Nuria; Vallejo, Islen; van den Bossche, Joris; Lahoz, William; Bartonova, Alena

    2016-04-01

    With the technology of air quality sensors improving rapidly in recent years and with an increasing number of initiatives for collecting air quality information being established worldwide, there is a rapidly increasing amount of information on air quality. Such datasets can provide unprecedented spatial detail and thus exhibit a significant potential for allowing to create observation-based high-resolution maps of air quality in the urban environment. However, most datasets of observations made within a citizen science or crowdsourcing framework tend to have highly variable characteristics in terms of quantity, accuracy, measured parameters, and representativeness, and many more. It is therefore currently unknown how to best exploit this information for mapping purposes. In order to address this challenge we present a novel approach for combining crowdsourced observations of urban air quality with model information, allowing us to produce near-real-time, high-resolution maps of air quality in the urban environment. The approach is based on data fusion techniques, which allow for combining observations with model data in a mathematically objective way and therefore provide a means of adding value to both the observations and the model. The observations are improved by filling spatio-temporal gaps in the data and the model is improved by constraining it with observations. The model further provides detailed spatial patterns in areas where no observations are available. As such, data fusion of observations from high-density low-cost sensor networks together with air quality models can contribute to significantly improving urban-scale air quality mapping. The system has been implemented to run in an automated fashion in near real-time (once every hour) for several cities in Europe. Evaluation of the methodology is being carried out using the leave-one-out cross validation technique and simulated datasets. We present case studies demonstrating the methodology for

  11. Group Time in Early Childhood Centers: An Exploratory Study.

    ERIC Educational Resources Information Center

    McAfee, Oralie

    To investigate the current status of group time in early childhood centers, a small-scale exploratory study was designed and executed. Results of interviews with 35 teachers and observations in five classrooms serving children ages 2 1/2 through kindergarten revealed that all classrooms had at least one group time or circle time, usually in the…

  12. Cross-Modal Distortion of Time Perception: Demerging the Effects of Observed and Performed Motion

    PubMed Central

    Hass, Joachim; Blaschke, Stefan; Herrmann, J. Michael

    2012-01-01

    Temporal information is often contained in multi-sensory stimuli, but it is currently unknown how the brain combines e.g. visual and auditory cues into a coherent percept of time. The existing studies of cross-modal time perception mainly support the “modality appropriateness hypothesis”, i.e. the domination of auditory temporal cues over visual ones because of the higher precision of audition for time perception. However, these studies suffer from methodical problems and conflicting results. We introduce a novel experimental paradigm to examine cross-modal time perception by combining an auditory time perception task with a visually guided motor task, requiring participants to follow an elliptic movement on a screen with a robotic manipulandum. We find that subjective duration is distorted according to the speed of visually observed movement: The faster the visual motion, the longer the perceived duration. In contrast, the actual execution of the arm movement does not contribute to this effect, but impairs discrimination performance by dual-task interference. We also show that additional training of the motor task attenuates the interference, but does not affect the distortion of subjective duration. The study demonstrates direct influence of visual motion on auditory temporal representations, which is independent of attentional modulation. At the same time, it provides causal support for the notion that time perception and continuous motor timing rely on separate mechanisms, a proposal that was formerly supported by correlational evidence only. The results constitute a counterexample to the modality appropriateness hypothesis and are best explained by Bayesian integration of modality-specific temporal information into a centralized “temporal hub”. PMID:22701603

  13. Cross-modal distortion of time perception: demerging the effects of observed and performed motion.

    PubMed

    Hass, Joachim; Blaschke, Stefan; Herrmann, J Michael

    2012-01-01

    Temporal information is often contained in multi-sensory stimuli, but it is currently unknown how the brain combines e.g. visual and auditory cues into a coherent percept of time. The existing studies of cross-modal time perception mainly support the "modality appropriateness hypothesis", i.e. the domination of auditory temporal cues over visual ones because of the higher precision of audition for time perception. However, these studies suffer from methodical problems and conflicting results. We introduce a novel experimental paradigm to examine cross-modal time perception by combining an auditory time perception task with a visually guided motor task, requiring participants to follow an elliptic movement on a screen with a robotic manipulandum. We find that subjective duration is distorted according to the speed of visually observed movement: The faster the visual motion, the longer the perceived duration. In contrast, the actual execution of the arm movement does not contribute to this effect, but impairs discrimination performance by dual-task interference. We also show that additional training of the motor task attenuates the interference, but does not affect the distortion of subjective duration. The study demonstrates direct influence of visual motion on auditory temporal representations, which is independent of attentional modulation. At the same time, it provides causal support for the notion that time perception and continuous motor timing rely on separate mechanisms, a proposal that was formerly supported by correlational evidence only. The results constitute a counterexample to the modality appropriateness hypothesis and are best explained by Bayesian integration of modality-specific temporal information into a centralized "temporal hub".

  14. Space- and time-resolved observation of extreme laser frequency upshifting during ultrafast-ionization

    SciTech Connect

    Giulietti, A.; Koester, P.; Levato, T.; Pathak, N. C.; André, A.; Dobosz Dufrénoy, S.; Monot, P.; Giulietti, D.; Hosokai, T.; Kotaki, H.; Labate, L.; Gizzi, L. A.; Nuter, R.

    2013-08-15

    A 65-fs, 800-nm, 2-TW laser pulse propagating through a nitrogen gas jet has been experimentally studied by 90° Thomson scattering. Time-integrated spectra of scattered light show unprecedented broadening towards the blue which exceeds 300 nm. Images of the scattering region provide for the first time a space- and time-resolved description of the process leading quite regularly to such a large upshift. The mean shifting rate was as high as δλ/δt ≈ 3 Å/fs, never observed before. Interferometry shows that it occurs after partial laser defocusing. Numerical simulations prove that such an upshift is consistent with a laser-gas late interaction, when laser intensity has decreased well below relativistic values (a{sub 0}≪ 1) and ionization process involves most of the laser pulse. This kind of interaction makes spectral tuning of ultrashort intense laser pulses possible in a large spectral range.

  15. 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.

  16. 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.

  17. First-time comet observations at the National Observatory of Turkey

    NASA Astrophysics Data System (ADS)

    Oklay, N.; Vincent, J.

    2014-07-01

    activity structures are investigated and simulations of dust tail are performed. On December 2013, we performed the first comet spectroscopy, targeting comet 154P and, additionally, observed comet C/2013 R1 in the Bessell R, B, and V filters. Results: Some additional gas filters for comet observations would be very useful for further observations. Fortunately, the budget for them is approved for 2014, and they are in the selection process. This will significantly improve future comet observations at TUG. T100: Imaging of fast-moving bright comets (like ISON) can be achieved by using short exposure times on the remotely operable T100 telescope, but non-sidereal tracking has to be improved for the observation of fast-moving small bodies of the solar system. Studies on the improvement of T100's tracking have already started at TUG. RTT150: Non-sidereal tracking is excellent and allowed us to take spectra of comet 154P. For future, we have established collaboration with the Rosetta mission and will monitor comet 67P/Churyumov-Gerasimenko starting from spring 2015. We are also ready for Gaia follow-up observations of solar-system objects with RTT150 (max. 5 nights/yr), T100 (max. 80 h/yr), and T60 (10--15 % of the total observing time).

  18. Use of a checklist during observation of a simulated cardiac arrest scenario does not improve time to CPR and defibrillation over observation alone for subsequent scenarios.

    PubMed

    Dilley, Stuart J; Weiland, Tracey J; O'Brien, Robert; Cunningham, Neil J; Van Dijk, Julian E; Mahoney, Rosie M; Williams, Matthew J

    2015-01-01

    Immersive simulation is a common mode of education for medical students. Observation of clinical simulations prior to participation is believed to be beneficial, though this is often a passive process. Active observation may be more beneficial. The hypothesis tested in this study was that the active use of a simple checklist during observation of an immersive simulation would result in better participant performance in a subsequent scenario compared with passive observation alone. Medical students were randomized to either passive or active (with checklist) observation of an immersive simulation involving cardiac arrest prior to participating in their own simulation. Performance measures included time to cardiopulmonary resuscitation (CPR) and time to defibrillation and were compared between first and second scenarios as well as between passive and active observers. Seventy-nine simulations involving 232 students were conducted. Mean time to CPR was 18 seconds (SD = 11.6) for those using the checklist and 24 seconds (SD = 15.8) for those who observed passively (M difference = 6 seconds), t(35) = 1.46, p =.153. Time to defibrillation was 94 seconds (SD = 26.4) for those using the checklist and 92 seconds (SD = 23.8) for those who observed passively (M difference = -2 seconds), t(38) =.21, p =.837. Time to CPR was 24 seconds (SD = 15.8) for passive observers and 31 seconds (SD = 21.0; M difference = 7 seconds), t(35) = 1.13, p =.265, for their first scenario counterparts. Time to CPR was 18 seconds (SD = 11.6) for active observers and 36 seconds (SD = 26.2; M difference = 18 seconds), t(24) = 2.81, p =.010, for their first scenario counterparts. Time to defibrillation was 92 seconds (SD = 23.8) for passive observers and 125 seconds (SD = 32.2; M difference = 33 seconds), t(33) = 3.63, p =.001, for their first scenario counterparts. Time to defibrillation was 94 seconds (SD = 26.4) for the active observers and 132 seconds (SD = 52.9; M difference = 38 seconds), t(28

  19. Storm time response of the midlatitude thermosphere: Observations from a network of Fabry-Perot interferometers

    NASA Astrophysics Data System (ADS)

    Makela, Jonathan J.; Harding, Brian J.; Meriwether, John W.; Mesquita, Rafael; Sanders, Samuel; Ridley, Aaron J.; Castellez, Michael W.; Ciocca, Marco; Earle, Gregory D.; Frissell, Nathaniel A.; Hampton, Donald L.; Gerrard, Andrew J.; Noto, John; Martinis, Carlos R.

    2014-08-01

    Observations of thermospheric neutral winds and temperatures obtained during a geomagnetic storm on 2 October 2013 from a network of six Fabry-Perot interferometers (FPIs) deployed in the Midwest United States are presented. Coincident with the commencement of the storm, the apparent horizontal wind is observed to surge westward and southward (toward the equator). Simultaneous to this surge in the apparent horizontal winds, an apparent downward wind of approximately 100 m/s lasting for 6 h is observed. The apparent neutral temperature is observed to increase by approximately 400 K over all of the sites. Observations from an all-sky imaging system operated at the Millstone Hill observatory indicate the presence of a stable auroral red (SAR) arc and diffuse red aurora during this time. We suggest that the large sustained apparent downward winds arise from contamination of the spectral profile of the nominal thermospheric 630.0 nm emission by 630.0 nm emission from a different (nonthermospheric) source. Modeling demonstrates that the effect of an additional population of 630.0 nm photons, with a distinct velocity and temperature distribution, introduces an apparent Doppler shift when the combined emissions from the two sources are analyzed as a single population. Thus, the apparent Doppler shifts should not be interpreted as the bulk motion of the thermosphere, calling into question results from previous FPI studies of midlatitude storm time thermospheric winds. One possible source of contamination could be fast O related to the infusion of low-energy O+ ions from the magnetosphere. The presence of low-energy O+ is supported by observations made by the Helium, Oxygen, Proton, and Electron spectrometer instruments on the twin Van Allen Probes spacecraft, which show an influx of low-energy ions during this period. These results emphasize the importance of distributed networks of instruments in understanding the complex dynamics that occur in the upper atmosphere during

  20. Time Variations of the ENA Flux Observed by IBEX: Is the Outer Heliosphere Evolving?

    NASA Astrophysics Data System (ADS)

    McComas, D. J.; Bzowski, M.; Clark, G.; Crew, G. B.; Demajistre, R.; Funsten, H. O.; Fuselier, S. A.; Gruntman, M.; Janzen, P.; Livadiotis, G.; Moebius, E.; Reisenfeld, D. B.; Roelof, E. C.; Schwadron, N. A.

    2009-12-01

    The Interstellar Boundary Explorer (IBEX) mission has just provided the first global observations of the heliosphere’s interstellar interaction [McComas et al., 2009 and other papers in the IBEX special issue of Science]. IBEX all-sky maps and energy spectra provide detailed information about this interaction. Because of the way IBEX collects its observations, each swath of the sky is revisited every six months, with the winter viewing, when IBEX’s orbit is largely sunward of the Earth, providing significantly cleaner measurements than the summer season, when IBEX’s orbit rotates through the Earth’s magnetosheath and magnetotail. Very limited initial overlapping data showed that the observed structure was largely stable over the first six months of observations, however, it also suggested the tantalizing possibility that there could be some temporal evolution. By the time of the Fall AGU meeting, much of the sky will be imaged a second time. This study will provide a comparison of these sets of observations, especially at higher energies where the statistics are better, and directly address the question of if the outer heliosphere is evolving over timescales on the order of half a year. Reference McComas, D.J., F. Allegrini, P. Bochsler, M. Bzowski, E.R. Christian, G.B. Crew, R. DeMajistre, H. Fahr, H. Fichtner, P.C. Frisch, H.O. Funsten, S. A. Fuselier, G. Gloeckler, M. Gruntman, J. Heerikhuisen, V. Izmodenov, P. Janzen, P. Knappenberger, S. Krimigis, H. Kucharek, M. Lee, G. Livadiotis, S. Livi, R.J. MacDowall, D. Mitchell, E. Möbius, T. Moore, N.V. Pogorelov, D. Reisenfeld, E. Roelof, L. Saul, N.A. Schwadron, P.W. Valek, R. Vanderspek, P. Wurz, G.P. Zank, First Global Observations of the Interstellar Interaction from the Interstellar Boundary Explorer, submitted to Science, 2009.

  1. Western scrub-jays allocate longer observation time to more valuable information.

    PubMed

    Watanabe, Arii; Grodzinski, Uri; Clayton, Nicola S

    2014-07-01

    When humans mentally reconstruct past events and imagine future scenarios, their subjective experience of mentally time travelling is accompanied by the awareness of doing so. Despite recent popularity of studying episodic memory in animals, such phenomenological consciousness has been extremely difficult to demonstrate without agreed behavioural markers of consciousness in non-linguistic subjects. We presented western scrub-jays (Aphelocoma californica) with a task requiring them to allocate observing time between two peepholes to see food being hidden in either of two compartments, one where observing the hiding location was necessary to later relocate the food, and another where food could easily be found without watching. Jays first separately experienced these consequences of possessing information in each compartment and subsequently, once given a choice, made more looks and spent more time looking into the compartment where information was necessary than into the compartment where it was unnecessary. Thus, the jays can collect information to solve a future problem. Moreover, they can differentiate sources of information according to their potential value and modify behaviour to efficiently collect important, usable information. This is the first evidence of metacognition in a species that passes the behavioural criteria for both retrospective and prospective mental time travel.

  2. Potential New Lidar Observations for Cloud Studies

    NASA Technical Reports Server (NTRS)

    Winker, Dave; Hu, Yong; Narir, Amin; Cai, Xia

    2015-01-01

    The response of clouds to global warming represents a major uncertainty in estimating climate sensitivity. These uncertainties have been tracked to shallow marine clouds in the tropics and subtropics. CALIOP observations have already been used extensively to evaluate model predictions of shallow cloud fraction and top height (Leahy et al. 2013; Nam et al 2012). Tools are needed to probe the lowest levels of the troposphere. The large footprint of satellite lidars gives large multiple scattering from clouds which presents new possibilities for cloud retrievals to constrain model predictions.

  3. Study Time, Motivation and Students' Achievement.

    ERIC Educational Resources Information Center

    Youssef, Anga A.

    A study investigating the relationship between motivation, study time, and student achievement in second language courses has as subjects 97 tenth- and eleventh-grade English speakers in introductory French, German, and Spanish courses. Two surveys measured motivational factors and the amount of time spent studying the second language. Motivation…

  4. A new approach to calibrate steady groundwater flow models with time series of head observations

    NASA Astrophysics Data System (ADS)

    Obergfell, C.; Bakker, M.; Maas, C.

    2012-04-01

    We developed a new method to calibrate aquifer parameters of steady-state well field models using measured time series of head fluctuations. Our method is an alternative to standard pumping tests and is based on time series analysis using parametric impulse response functions. First, the pumping influence is isolated from the overall groundwater fluctuation observed at monitoring wells around the well field, and response functions are determined for each individual well. Time series parameters are optimized using a quasi-Newton algorithm. For one monitoring well, time series model parameters are also optimized by means of SCEM-UA, a Markov Chain Monte Carlo algorithm, as a control on the validity of the parameters obtained by the faster quasi-Newton method. Subsequently, the drawdown corresponding to an average yearly pumping rate is calculated from the response functions determined by time series analysis. The drawdown values estimated with acceptable confidence intervals are used as calibration targets of a steady groundwater flow model. A case study is presented of the drinking water supply well field of Waalwijk (Netherlands). In this case study, a uniform aquifer transmissivity is optimized together with the conductance of ditches in the vicinity of the well field. Groundwater recharge or boundary heads do not have to be entered, which eliminates two import sources of uncertainty. The method constitutes a cost-efficient alternative to pumping tests and allows the determination of pumping influences without changes in well field operation.

  5. The application of time-lapse photography for the observation of snow processes in mountainous catchments

    NASA Astrophysics Data System (ADS)

    Garvelmann, J.; Pohl, S.; Weiler, M.

    2012-04-01

    For the forecast of snowmelt flood events in mountainous catchments it is very important to know the spatial distribution and temporal evolution of the snowcover. Topography and vegetation have the most important influence on the spatio-temporal variability of the snowcover. In order to accomplish a continuous observation of the quantity and the status of the snowcover, an extensive measurement network consisting of numerous standalone snow and meteorological sensors and time-lapse photography was established in three catchments in the Black Forest, a typical mid latitude medium elevation mountain range. Catchments with different topographic characteristic and areal extent were specifically chosen for this study. Within the catchments, a stratified sampling design was used to cover a wide range of altitudes and exposures. In order to investigate the influence of a vegetation cover on the snow processes beneath sensors and cameras have been installed under the forest canopy and on adjacent open field sites, respectively. In the presented study the application of spatially distributed time-lapse cameras for the observation of snow processes and snowcover properties at the catchment scale will be discussed. Image analysis software was applied to extract information about snowdepth, snow albedo and canopy interception from the digital images. A measurement scale with a black/white board was installed in the focus of every camera to allow a determination of the snowdepth at every camera location while the black/white board was used to provide a white balance for the albedo estimation. The albedo provides important information about the status of the snowcover and its temporal evolution is a crucial factor for the snowmelt energy balance. Furthermore the time-lapse images provided a continuous observation of the forest canopy allowing the estimation of the interception efficiency and the temporal evolution of the snow interception for different topographic situations

  6. Relativistic Electron Precipitation: An Observational Study.

    DTIC Science & Technology

    1980-01-01

    information. Four hours of continuous data was collected and transmitted each tape recorder dump. Over the life of the satellite, approximately 25% data...Langmuir probe to make relative density fluctuations. Broadband signals (.05 - 16 kHz) were transmitted in real time to ground stations for 15 min periods...912756444007 - 00~~~~~~2 ?420 212 0060046 26 712 g4 -69.~ WA02431 7626 M4423 1024 415 6474080 COO to2 700 1633S 1932 4495 74390.. COD t$429 o 393032

  7. A deterministic approach to define the useful integration time for in-situ precipitation observations

    NASA Astrophysics Data System (ADS)

    Djallel Dilmi, Mohamed; Mallet, Cécile; Barthes, Laurent; Chazottes, Aymeric

    2017-04-01

    The Precipitations are due to complex meteorological phenomenon and can be described as intermittent process. Theirs spatial and temporal variability is significant and covers large scales. These precipitation properties induce a very strong constraint on the measurement, which must be as continuous as possible, both in time and in space. . In particular, studies of climate change need high-resolution rainfall with resolutions much higher than 1 hour to obtain statistics of extrem rainfall and wet and dry spell duration. For all these reasons, several instruments were used for the observation of precipitations, of which the tipping bucket rain gauge is the oldest and the most commonly used for the precipitations in-situ measurements. Each specific device properties can induces systematical occurring errors that can lead to statistical biases. For example, for low precipitation, the tipping bucket rain gauge, records false dry periods. So, during the past few years, other instruments more accurate than the tipping bucket rain gauge (eg disdrometer and weighting rain gauge) were placed for in-situ observation but their costs hinder the installation of large networks The present study focuses on the impact of the rain gauge volume. The aim is to define a minimal integration time according to the bucket volume for a given climatic region Our study focuses on Ile-de-France, this French region is a relatively dry region if we consider the annual amount of precipitation: 600 mm, a rainy region if we consider the number of days of precipitation per year: 160 days. It records Strong storm events sometimes but its precipitations are dominated by low rainfall. Eight year time series observed with a disdrometer and different rain gauges located on the French Atmospheric Research Observatory (SIRTA) , are used. Simulated tipping bucket rain gauge series for different tipping bucket volumes and weighting rain gauge series for different weights as precision are performed. The

  8. 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.

  9. Transit Timing Study of Kepler Planets

    NASA Astrophysics Data System (ADS)

    Xie, Jiwei

    2015-08-01

    Kepler space telescope has found over 4000 transiting planet candidates. Transit timing is a powerful tool to study these transit planet candidates. In this talk, I will talk about two transit timing techniques, i.e., transit timing variation (TTV) and transit duration (TD), which enable confirming their planetary nature and obtaining insight into their orbital properties.

  10. 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.

  11. Time-varying spatial data integration and visualization: 4 Dimensions Environmental Observations Platform (4-DEOS)

    NASA Astrophysics Data System (ADS)

    Paciello, Rossana; Coviello, Irina; Filizzola, Carolina; Genzano, Nicola; Lisi, Mariano; Mazzeo, Giuseppe; Pergola, Nicola; Sileo, Giancanio; Tramutoli, Valerio

    2014-05-01

    In environmental studies the integration of heterogeneous and time-varying data, is a very common requirement for investigating and possibly visualize correlations among physical parameters underlying the dynamics of complex phenomena. Datasets used in such kind of applications has often different spatial and temporal resolutions. In some case superimposition of asynchronous layers is required. Traditionally the platforms used to perform spatio-temporal visual data analyses allow to overlay spatial data, managing the time using 'snapshot' data model, each stack of layers being labeled with different time. But this kind of architecture does not incorporate the temporal indexing neither the third spatial dimension which is usually given as an independent additional layer. Conversely, the full representation of a generic environmental parameter P(x,y,z,t) in the 4D space-time domain could allow to handle asynchronous datasets as well as less traditional data-products (e.g. vertical sections, punctual time-series, etc.) . In this paper we present the 4 Dimensions Environmental Observation Platform (4-DEOS), a system based on a web services architecture Client-Broker-Server. This platform is a new open source solution for both a timely access and an easy integration and visualization of heterogeneous (maps, vertical profiles or sections, punctual time series, etc.) asynchronous, geospatial products. The innovative aspect of the 4-DEOS system is that users can analyze data/products individually moving through time, having also the possibility to stop the display of some data/products and focus on other parameters for better studying their temporal evolution. This platform gives the opportunity to choose between two distinct display modes for time interval or for single instant. Users can choose to visualize data/products in two ways: i) showing each parameter in a dedicated window or ii) visualize all parameters overlapped in a single window. A sliding time bar, allows

  12. Observation of coherence in the time-reversed relativistic photoelectric effect.

    PubMed

    Tashenov, S; Banaś, D; Beyer, H; Brandau, C; Fritzsche, S; Gumberidze, A; Hagmann, S; Hillenbrand, P-M; Jörg, H; Kojouharov, I; Kozhuharov, Ch; Lestinsky, M; Litvinov, Yu A; Maiorova, A V; Schaffner, H; Shabaev, V M; Spillmann, U; Stöhlker, Th; Surzhykov, A; Trotsenko, S

    2014-09-12

    The photoelectric effect has been studied in the regime of hard x rays and strong Coulomb fields via its time-reversed process of radiative recombination (RR). In the experiment, the relativistic electrons recombined into the 2p_{3/2} excited state of hydrogenlike uranium ions, and both the RR x rays and the subsequently emitted characteristic x rays were detected in coincidence. This allowed us to observe the coherence between the magnetic substates in a highly charged ion and to identify the contribution of the spin-orbit interaction to the RR process.

  13. Learning characteristics of a space-time neural network as a tether skiprope observer

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.; Villarreal, James A.; Jani, Yashvant; Copeland, Charles

    1992-01-01

    The Software Technology Laboratory at JSC is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table.

  14. Learning characteristics of a space-time neural network as a tether skiprope observer

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.; Villarreal, James A.; Jani, Yashvant; Copeland, Charles

    1993-01-01

    The Software Technology Laboratory at the Johnson Space Center is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table.

  15. Observations of breakup processes of liquid jets using real-time X-ray radiography

    NASA Technical Reports Server (NTRS)

    Char, J. M.; Kuo, K. K.; Hsieh, K. C.

    1988-01-01

    To unravel the liquid-jet breakup process in the nondilute region, a newly developed system of real-time X-ray radiography, an advanced digital image processor, and a high-speed video camera were used. Based upon recorded X-ray images, the inner structure of a liquid jet during breakup was observed. The jet divergence angle, jet breakup length, and fraction distributions along the axial and transverse directions of the liquid jets were determined in the near-injector region. Both wall- and free-jet tests were conducted to study the effect of wall friction on the jet breakup process.

  16. Long term variability in migrating diurnal tide observed by the TIMED Doppler Interferometer (TIDI)

    NASA Astrophysics Data System (ADS)

    Killeen, T. L.; Wu, Q.; Solomon, S. C.; Ortland, D. A.; Skinner, W. R.; Niciejewski, R. J.

    2007-12-01

    We will examine the temporal variations of migrating diurnal tide in the mesosphere and lower thermosphere using the TIMED Doppler interferometer neutral wind data. The stratosphere QBO is the major source for the interannual variability of the migrating tide in the mesosphere and lower thermosphere. Buy examine the tidal variations using spectral analysis method, we plan to examine long term variations in the migrating diurnal tides beyond these related to the QBO. The TIDI data will allow us to examine the diurnal tide variation at different latitudes and altitudes. We will also study stratosphere observations in search of possible connections to changes in the stratosphere.

  17. Continuous uniformly finite time exact disturbance observer based control for fixed-time stabilization of nonlinear systems with mismatched disturbances

    PubMed Central

    Liu, Chongxin; Liu, Hang

    2017-01-01

    This paper presents a continuous composite control scheme to achieve fixed-time stabilization for nonlinear systems with mismatched disturbances. The composite controller is constructed in two steps: First, uniformly finite time exact disturbance observers are proposed to estimate and compensate the disturbances. Then, based on adding a power integrator technique and fixed-time stability theory, continuous fixed-time stable state feedback controller and Lyapunov functions are constructed to achieve global fixed-time system stabilization. The proposed control method extends the existing fixed-time stable control results to high order nonlinear systems with mismatched disturbances and achieves global fixed-time system stabilization. Besides, the proposed control scheme improves the disturbance rejection performance and achieves performance recovery of nominal system. Simulation results are provided to show the effectiveness, the superiority and the applicability of the proposed control scheme. PMID:28406966

  18. 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.

  19. Towards real-time assimilation of crowdsourced observations in hydrological modeling

    NASA Astrophysics Data System (ADS)

    Mazzoleni, Maurizio; Verlaan, Martin; Alfonso, Leonardo; Norbiato, Daniele; Monego, Martina; Ferri, Michele; Solomatine, Dimitri

    2016-04-01

    The continued technological advances have stimulated the spread of low-cost sensors that can be used by citizens to provide crowdsourced observations (CO) of different hydrological variables. An example of such low-cost sensors is a staff gauge connected to a QR code on which people can read the water level indication and send the measurement via a mobile phone application. The goal of this study is to assess the combined effect of the assimilation of CO coming from a distributed network of low-cost sensors, and the existing streamflow observations from physical sensors, on the performance of a semi-distributed hydrological model. The methodology is applied to the Bacchiglione catchment, North East of Italy, where an early warning system is used by the Alto Adriatico Water Authority to issue forecasted water level along the river network which cross important cities such as Vicenza and Padua. In this study, forecasted precipitation values are used as input in the hydrological model to estimate the simulated streamflow hydrograph used as boundary condition for the hydraulic model. Observed precipitation values are used to generate realistic synthetic streamflow values with various characteristics of arrival frequency and accuracy, to simulate CO coming at irregular time steps. These observations are assimilated into the semi-distributed model using a Kalman filter based method. The results of this study show that CO, asynchronous in time and with variable accuracy, can still improve flood prediction when integrated in hydrological models. When both physical and low-cost sensors are located at the same places, the assimilation of CO gives the same model improvement than the assimilation of physical observations only for high number of non-intermittent sensors. However, the integration of observations from low-cost sensors and single physical sensors can improve the flood prediction even when small a number of intermittent CO are available. This study is part of the

  20. Anesthesia alarms in context: an observational study.

    PubMed

    Seagull, F J; Sanderson, P M

    2001-01-01

    This paper surveys current work on the design of alarms for anesthesia environments and notes some of the problems arising from the need to interpret alarms in context. Anesthetists' responses to audible alarms in the operating room were observed across four types of surgical procedure (laparoscopic, arthroscopic, cardiac, and intracranial) and across three phases of a procedure (induction, maintenance, and emergence). Alarms were classified as (a) requiring a corrective response, (b) being the intended result of a decision, (c) being ignored as a nuisance alarm, or (d) functioning as a reminder. Results revealed strong effects of the type of procedure and phase of procedure on the number and rate of audible alarms. Some alarms were relatively confined to specific phases; others were seen across phases, and responses differed according to phase. These results were interpreted in light of their significance for the development of effective alarm systems. Actual or potential applications of this research include the design of alarm systems that are more informative and more sensitive to operative context than are current systems.

  1. Optical specification of time-to-passage: Observers' sensitivity to global tau

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.; Mowafy, Lyn

    1993-01-01

    Despite its general mathematical formulation, most empirical work on the visual perception of tau (defined as a quantity divided by its temporal derivative) has focused on the case of direct approach, with tau defined as image angle/rate of expansion. Empirical investigators tend to generalize image size analyses to off-axis approaches. However, this generalization is inappropriate for all but a few classes of objects. After mathematically reestablishing the appropriate optical cues specifying time to passage for noncollision cases, we report a series of studies in which we examined observers' sensitivities to this information in both relative- and absolute-judgment paradigms. In general, we found observers' judgments to be accurate and robust.

  2. Real-time in vitro observation of cavitation in a prosthetic heart valve.

    PubMed

    Lamson, T C; Stinebring, D R; Deutsch, S; Rosenberg, G; Tarbell, J M

    1991-01-01

    A technique for real-time in vitro observation of cavitation on a prosthetic heart valve operating in a ventricular assist device under normal physiologic conditions has been developed. Considering the documented observation of cavitation erosion in heart valve components from human explants, and the potential risk of blood damage that cavitation presents, the technique developed in this study may prove useful in the design of prosthetic heart valves and ventricular assist devices. Cavitation of a glycerol blood analog fluid has been documented for a Medtronic/Hall prosthetic heart valve operating in a Penn State Electric Ventricular Assist Device. The ventricular assist device was operated in a mock circulatory system under normal physiologic conditions. The valve was located in the mitral position, with the cavitation occurring on the inlet side after valve closure. Bubble cavitation was seen on the valve occluder face, and vortex cavitation was observed at two locations in the vicinity of the valve occluder and housing. The cavity growth and collapse cycle for these forms of vaporous cavitation was less than 1 msec. Stroboscopic photography and stroboscopic videography with frame grabbing were used to document the cavity life cycle. With beat rate held constant, the cavity duration time was found to decrease with increasing mean venous return pressure.

  3. 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.

  4. Observational Study of Contracts Processing at 29 CTSA Sites

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2013-08-01

    We measured contracts final negotiation (FN) and full execution (FE) times using shared definitions in a prospective observational study of management of contracts for clinical trials at 29 CTSA institutions. Median FN and FE times were reached in 39 and 91 days, respectively; mean times for FN and FE were 55 and 103 days, respectively. Individual site medians ranged from 3 to 116 days for FN and 34 to 197 days for FE. The use of master agreements (MAs) and previously negotiated terms (PNTs) was associated with significant reduction of FN times by a mean of 33 days (p < 0) and 22 days (p < 0.001), respectively. PNTs, but not MAs, were associated with significantly reduced FE time (22 days, p < 0.007). Gap analysis revealed a gap of 22 days between contracts negotiation and Institutional Review Board (IRB) review and intervals of 33 days (contracts) and 48 days (IRB review) during which the process steps were being conducted alone, suggesting a potential benefit with parallel processing. These baseline data support a plan to investigate root causes of prolonged study start-up time by examining causes of variation and outliers. © 2013 Wiley Periodicals, Inc.

  6. Memory-induced diffusive-superdiffusive transition: Ensemble and time-averaged observables

    NASA Astrophysics Data System (ADS)

    Budini, Adrián A.

    2017-05-01

    The ensemble properties and time-averaged observables of a memory-induced diffusive-superdiffusive transition are studied. The model consists in a random walker whose transitions in a given direction depend on a weighted linear combination of the number of both right and left previous transitions. The diffusion process is nonstationary, and its probability develops the phenomenon of aging. Depending on the characteristic memory parameters, the ensemble behavior may be normal, superdiffusive, or ballistic. In contrast, the time-averaged mean squared displacement is equal to that of a normal undriven random walk, which renders the process nonergodic. In addition, and similarly to Lévy walks [Godec and Metzler, Phys. Rev. Lett. 110, 020603 (2013), 10.1103/PhysRevLett.110.020603], for trajectories of finite duration the time-averaged displacement apparently become random with properties that depend on the measurement time and also on the memory properties. These features are related to the nonstationary power-law decay of the transition probabilities to their stationary values. Time-averaged response to a bias is also calculated. In contrast with Lévy walks [Froemberg and Barkai, Phys. Rev. E 87, 030104(R) (2013), 10.1103/PhysRevE.87.030104], the response always vanishes asymptotically.

  7. Part Time Study in Higher Education.

    ERIC Educational Resources Information Center

    Neville, Colin

    This document, which is intended for adults considering enrolling in part-time study in higher education, examines the objectives and experiences of adults who have pursued part-time study in higher education in the United Kingdom. The following reasons why adults return to higher education are discussed: personal development; self-fulfillment;…

  8. Soft Fourier time lags observed in the dwarf nova SS Cyg

    NASA Astrophysics Data System (ADS)

    Aranzana, E.; Scaringi, S.; K"ording, E.

    2014-07-01

    Accretion is a common phenomenon in active galactic nuclei (AGNs), X-ray binary systems (XRBs) and cataclysmic variables (CVs), providing different scenarios to study the physics involved in accretion discs. It has been shown that XRBs and CVs show similar observational properties such as recurrent outbursts, spectral state transitions and aperiodic variability. The latter has been extensively studied for XRBs, but only recently has the rms-flux relation and optical Fourier time-lags been observed in CVs. We present a broad-band Fourier analysis of the well-known cataclysmic variable SS Cyg in quiescence based on data collected by William Herschel Telescope using ULTRACAM. Lightcurves in SDSS filters u', g' and r' were taken simultaneously with sub-second cadence. The high sensitive camera allows us to study the broad-band noise of the source in a frequency range of ≈ 10^{-4}-2 Hz. We explored the coherence, cross spectra and the power spectral densities that are well described by a power law. Soft lags at lowest frequencies were observed indicating that the emission in the softer bands lags the emission in the harder bands. This can be possibly described by hard photons reprocessing created in the boundary layer close to the white dwarf.

  9. Solar Activity Studies using Microwave Imaging Observations

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.

    2016-01-01

    We report on the status of solar cycle 24 based on polar prominence eruptions (PEs) and microwave brightness enhancement (MBE) information obtained by the Nobeyama radioheliograph. The north polar region of the Sun had near-zero field strength for more than three years (2012-2015) and ended only in September 2015 as indicated by the presence of polar PEs and the lack of MBE. The zero-polar-field condition in the south started only around 2013, but it ended by June 2014. Thus the asymmetry in the times of polarity reversal switched between cycle 23 and 24. The polar MBE is a good proxy for the polar magnetic field strength as indicated by the high degree of correlation between the two. The cross-correlation between the high- and low-latitude MBEs is significant for a lag of approximately 5.5 to 7.3 years, suggesting that the polar field of one cycle indicates the sunspot number of the next cycle in agreement with the Babcock-Leighton mechanism of solar cycles. The extended period of near-zero field in the north-polar region should result in a weak and delayed sunspot activity in the northern hemisphere in cycle 25.

  10. Time Series Analysis of Remote Sensing Observations for Citrus Crop Growth Stage and Evapotranspiration Estimation

    NASA Astrophysics Data System (ADS)

    Sawant, S. A.; Chakraborty, M.; Suradhaniwar, S.; Adinarayana, J.; Durbha, S. S.

    2016-06-01

    Satellite based earth observation (EO) platforms have proved capability to spatio-temporally monitor changes on the earth's surface. Long term satellite missions have provided huge repository of optical remote sensing datasets, and United States Geological Survey (USGS) Landsat program is one of the oldest sources of optical EO datasets. This historical and near real time EO archive is a rich source of information to understand the seasonal changes in the horticultural crops. Citrus (Mandarin / Nagpur Orange) is one of the major horticultural crops cultivated in central India. Erratic behaviour of rainfall and dependency on groundwater for irrigation has wide impact on the citrus crop yield. Also, wide variations are reported in temperature and relative humidity causing early fruit onset and increase in crop water requirement. Therefore, there is need to study the crop growth stages and crop evapotranspiration at spatio-temporal scale for managing the scarce resources. In this study, an attempt has been made to understand the citrus crop growth stages using Normalized Difference Time Series (NDVI) time series data obtained from Landsat archives (http://earthexplorer.usgs.gov/). Total 388 Landsat 4, 5, 7 and 8 scenes (from year 1990 to Aug. 2015) for Worldwide Reference System (WRS) 2, path 145 and row 45 were selected to understand seasonal variations in citrus crop growth. Considering Landsat 30 meter spatial resolution to obtain homogeneous pixels with crop cover orchards larger than 2 hectare area was selected. To consider change in wavelength bandwidth (radiometric resolution) with Landsat sensors (i.e. 4, 5, 7 and 8) NDVI has been selected to obtain continuous sensor independent time series. The obtained crop growth stage information has been used to estimate citrus basal crop coefficient information (Kcb). Satellite based Kcb estimates were used with proximal agrometeorological sensing system

  11. Real-time microscopic observation of Candida biofilm development and effects due to micafungin and fluconazole.

    PubMed

    Kaneko, Yukihiro; Miyagawa, Susumu; Takeda, On; Hakariya, Masateru; Matsumoto, Satoru; Ohno, Hideaki; Miyazaki, Yoshitsugu

    2013-05-01

    To understand the process of Candida biofilm development and the effects of antifungal agents on biofilms, we analyzed real-time data comprising time-lapse images taken at times separated by brief intervals. The growth rate was calculated by measuring the change of biofilm thickness every hour. For the antifungal study, 5-h-old biofilms of Candida albicans were treated with either micafungin (MCFG) or fluconazole (FLCZ). MCFG began to suppress biofilm growth a few minutes after the initiation of the treatment, and this effect was maintained over the course of the observation period. In contrast, the suppressive effects of FLCZ on biofilm growth took longer to manifest: biofilms grew in the first 5 h after treatment, and then their growth was suppressed over the next 10 h, finally producing results similar to those observed with MCFG. MCFG was also involved in the disruption of cells in the biofilms, releasing string-like structures (undefined extracellular component) from the burst hyphae. Thus, MCFG inhibited the detachment of yeast cell clusters from the tips of hyphae. In contrast, FLCZ did not disrupt biofilm cells. MCFG also showed fast antifungal activity against Candida parapsilosis biofilms. In conclusion, our results show that inhibition of glucan synthesis due to MCFG contributed not only to fungicidal activity but also to the immediate suppression of biofilm growth, while FLCZ suppressed growth by inhibiting ergosterol synthesis. Therefore, those characteristic differences should be considered when treating clinical biofilm infections.

  12. Observation of discrete time-crystalline order in a disordered dipolar many-body system

    NASA Astrophysics Data System (ADS)

    Choi, Soonwon; Choi, Joonhee; Landig, Renate; Kucsko, Georg; Zhou, Hengyun; Isoya, Junichi; Jelezko, Fedor; Onoda, Shinobu; Sumiya, Hitoshi; Khemani, Vedika; von Keyserlingk, Curt; Yao, Norman Y.; Demler, Eugene; Lukin, Mikhail D.

    2017-03-01

    Understanding quantum dynamics away from equilibrium is an outstanding challenge in the modern physical sciences. Out-of-equilibrium systems can display a rich variety of phenomena, including self-organized synchronization and dynamical phase transitions. More recently, advances in the controlled manipulation of isolated many-body systems have enabled detailed studies of non-equilibrium phases in strongly interacting quantum matter; for example, the interplay between periodic driving, disorder and strong interactions has been predicted to result in exotic ‘time-crystalline’ phases, in which a system exhibits temporal correlations at integer multiples of the fundamental driving period, breaking the discrete time-translational symmetry of the underlying drive. Here we report the experimental observation of such discrete time-crystalline order in a driven, disordered ensemble of about one million dipolar spin impurities in diamond at room temperature. We observe long-lived temporal correlations, experimentally identify the phase boundary and find that the temporal order is protected by strong interactions. This order is remarkably stable to perturbations, even in the presence of slow thermalization. Our work opens the door to exploring dynamical phases of matter and controlling interacting, disordered many-body systems.

  13. Driving violations observed: an Australian study.

    PubMed

    Glendon, A Ian

    2007-08-01

    This study analyses 2,765 cases of driving behaviours in three Australian states - New South Wales, Queensland and Victoria. Data were gathered from in-car coordinated video and audio recording sequences in free-flowing traffic along two-, three- and four-lane highways with varying speed limits on all days of the week in daylight and fine weather conditions. Explanatory variables included driver age group and gender, passenger characteristics and vehicle age and type. Response variables included driving violations and other driving behaviours, including lane use, speeding, close following (tailgating), driver's hands position and mobile phone use. Data were analysed qualitatively and quantitatively. By focusing upon vehicle and driver characteristics, and their impact on driving behaviours, including identified violations, this study explores some implications both for future research and for traffic policy makers.

  14. Refractory status epilepticus: a prospective observational study.

    PubMed

    Novy, Jan; Logroscino, Giancarlo; Rossetti, Andrea O

    2010-02-01

    Status epilepticus (SE) that is resistant to two antiepileptic compounds is defined as refractory status epilepticus (RSE). In the few available retrospective studies, estimated RSE frequency is between 31% and 43% of patients presenting an SE episode; almost all seem to require a coma induction for treatment. We prospectively assessed RSE frequency, clinical predictors, and outcome in a tertiary clinical setting. Over 2 years we collected 128 consecutive SE episodes (118 patients) in adults. Clinical data and their relationship to outcome (mortality and return to baseline clinical conditions) were analyzed. Twenty-nine of 128 SE episodes (22.6%) were refractory to first- and second-line antiepileptic treatments. Severity of consciousness impairment and de novo episodes were independent predictors of RSE. RSE showed a worse outcome than non-RSE (39% vs. 11% for mortality; 21% vs. 63% for return to baseline clinical conditions). Only 12 patients with RSE (41%) required coma induction for treatment. This prospective study identifies clinical factors predicting the onset of SE refractoriness. RSE appears to be less frequent than previously reported in retrospective studies; furthermore, most RSE episodes were treated outside the intensive care unit (ICU). Nonetheless, we confirm that RSE is characterized by high mortality and morbidity.

  15. Real-time observation of crystal evaporation in a metal phosphate at high temperature.

    PubMed

    Chung, Sung-Yoon; Kim, Young-Min; Choi, Si-Young; Kim, Jin-Gyu

    2013-05-29

    A number of experimental studies on crystal growth have been performed in connection with a variety of crystalline systems ranging from simple oxides to complex organic compounds. In contrast, little is known regarding how crystals evaporate. By using a combination of real-time high-resolution electron microscopy at high temperature, image simulations, and density functional theory calculations, we demonstrate the evaporation of metal-phosphate nanocrystals with flat surfaces at atomic resolution. In situ imaging and direct comparison with image simulation results reveal that, while a layer-by-layer lateral process is macroscopically maintained, the cations preferentially evaporate over the (PO4)(3-) tetrahedral anions from shrinking ledges. The present observations provide the first atomic-scale experimental details of the evaporation of complex oxides, emphasizing the value of direct visualization in real time.

  16. Time-dependence of the electromechanical bending actuation observed in ionic-electroactive polymers

    NASA Astrophysics Data System (ADS)

    Bass, Patrick S.; Zhang, Lin; Cheng, Z.-Y.

    The characteristics of the electromechanical response observed in an ionic-electroactive polymer (i-EAP) are represented by the time (t) dependence of its bending actuation (y). The electromechanical response of a typical i-EAP — poly(ethylene oxide) (PEO) doped with lithium perchlorate (LP) — is studied. The shortcomings of all existing models describing the electromechanical response obtained in i-EAPs are discussed. A more reasonable model: y=ymaxe-τ/t is introduced to characterize this time dependence for all i-EAPs. The advantages and correctness of this model are confirmed using results obtained in PEO-LP actuators with different LP contents and at different temperatures. The applicability and universality of this model are validated using the reported results obtained from two different i-EAPs: one is Flemion and the other is polypyrrole actuators.

  17. Landmark estimation of survival and treatment effects in observational studies.

    PubMed

    Parast, Layla; Griffin, Beth Ann

    2017-04-01

    Clinical studies aimed at identifying effective treatments to reduce the risk of disease or death often require long term follow-up of participants in order to observe a sufficient number of events to precisely estimate the treatment effect. In such studies, observing the outcome of interest during follow-up may be difficult and high rates of censoring may be observed which often leads to reduced power when applying straightforward statistical methods developed for time-to-event data. Alternative methods have been proposed to take advantage of auxiliary information that may potentially improve efficiency when estimating marginal survival and improve power when testing for a treatment effect. Recently, Parast et al. (J Am Stat Assoc 109(505):384-394, 2014) proposed a landmark estimation procedure for the estimation of survival and treatment effects in a randomized clinical trial setting and demonstrated that significant gains in efficiency and power could be obtained by incorporating intermediate event information as well as baseline covariates. However, the procedure requires the assumption that the potential outcomes for each individual under treatment and control are independent of treatment group assignment which is unlikely to hold in an observational study setting. In this paper we develop the landmark estimation procedure for use in an observational setting. In particular, we incorporate inverse probability of treatment weights (IPTW) in the landmark estimation procedure to account for selection bias on observed baseline (pretreatment) covariates. We demonstrate that consistent estimates of survival and treatment effects can be obtained by using IPTW and that there is improved efficiency by using auxiliary intermediate event and baseline information. We compare our proposed estimates to those obtained using the Kaplan-Meier estimator, the original landmark estimation procedure, and the IPTW Kaplan-Meier estimator. We illustrate our resulting reduction in bias

  18. PRECISE HIGH-CADENCE TIME SERIES OBSERVATIONS OF FIVE VARIABLE YOUNG STARS IN AURIGA WITH MOST

    SciTech Connect

    Cody, Ann Marie; Tayar, Jamie; Hillenbrand, Lynne A.; Matthews, Jaymie M.; Kallinger, Thomas

    2013-03-15

    To explore young star variability on a large range of timescales, we have used the MOST satellite to obtain 24 days of continuous, sub-minute cadence, high-precision optical photometry on a field of classical and weak-lined T Tauri stars (TTSs) in the Taurus-Auriga star formation complex. Observations of AB Aurigae, SU Aurigae, V396 Aurigae, V397 Aurigae, and HD 31305 reveal brightness fluctuations at the 1%-10% level on timescales of hours to weeks. We have further assessed the variability properties with Fourier, wavelet, and autocorrelation techniques, identifying one significant period per star. We present spot models in an attempt to fit the periodicities, but find that we cannot fully account for the observed variability. Rather, all stars exhibit a mixture of periodic and aperiodic behavior, with the latter dominating stochastically on timescales less than several days. After removal of the main periodicity, periodograms for each light curve display power-law trends consistent with those seen for other young accreting stars. Several of our targets exhibited unusual variability patterns not anticipated by prior studies, and we propose that this behavior originates with the circumstellar disks. The MOST observations underscore the need for investigation of TTS light variations on a wide range of timescales in order to elucidate the physical processes responsible; we provide guidelines for future time series observations.

  19. Controlling and observing nonseparability of phonons created in time-dependent 1D atomic Bose condensates

    NASA Astrophysics Data System (ADS)

    Robertson, Scott; Michel, Florent; Parentani, Renaud

    2017-03-01

    We study the spectrum and entanglement of phonons produced by temporal changes in homogeneous one-dimensional atomic condensates. To characterize the experimentally accessible changes, we first consider the dynamics of the condensate when varying the radial trapping frequency, separately studying two regimes: an adiabatic one and an oscillatory one. Working in momentum space, we then show that in situ measurements of the density-density correlation function can be used to assess the nonseparability of the phonon state after such changes. We also study time-of-flight (TOF) measurements, paying particular attention to the role played by the adiabaticity of opening the trap on the nonseparability of the final state of atoms. In both cases, we emphasize that commuting measurements can suffice to assess nonseparability. Some recent observations are analyzed, and we make proposals for future experiments.

  20. Multiple indices method for real-time tsunami inundation forecast using a dense offshore observation network

    NASA Astrophysics Data System (ADS)

    Yamamoto, N.; Aoi, S.; Hirata, K.; Suzuki, W.; Kunugi, T.; Nakamura, H.

    2015-12-01

    We started to develop a new methodology for real-time tsunami inundation forecast system (Aoi et al., 2015, this meeting) using densely offshore tsunami observations of the Seafloor Observation Network for Earthquakes and Tsunamis (S-net), which is under construction along the Japan Trench (Kanazawa et al., 2012, JpGU; Uehira et al., 2015, IUGG). In our method, the most important concept is involving any type and/or form uncertainties in the tsunami forecast, which cannot be dealt with any of standard linear/nonlinear least square approaches. We first prepare a Tsunami Scenario Bank (TSB), which contains offshore tsunami waveforms at the S-net stations and tsunami inundation information calculated from any possible tsunami source. We then quickly select several acceptable tsunami scenarios that can explain offshore observations by using multiple indices and appropriate thresholds, after a tsunami occurrence. At that time, possible tsunami inundations coupled with selected scenarios are forecasted (Yamamoto et al., 2014, AGU). Currently, we define three indices: correlation coefficient and two variance reductions, whose L2-norm part is normalized either by observations or calculations (Suzuki et al., 2015, JpGU; Yamamoto et al., 2015, IUGG). In this study, we construct the TSB, which contains various tsunami source models prepared for the probabilistic tsunami hazard assessment in the Japan Trench region (Hirata et al., 2014, AGU). To evaluate the propriety of our method, we adopt the fault model based on the 2011 Tohoku earthquake as a pseudo "observation". We also calculate three indices using coastal maximum tsunami height distributions between observation and calculation. We then obtain the correlation between coastal and offshore indices. We notice that the index value of coastal maximum tsunami heights is closer to 1 than the index value of offshore waveforms, i.e., the coastal maximum tsunami height may be predictable within appropriate thresholds defined for

  1. Development of the SBIRT checklist for observation in real-time (SCORe).

    PubMed

    Vendetti, Janice A; McRee, Bonnie G; Del Boca, Frances K

    2017-02-01

    potential utility of the Screening, Brief Intervention and Referral to Treatment Checklist for Observation in Real-time protocol. © 2017 Society for the Study of Addiction.

  2. An observational study of emergency department intern activities.

    PubMed

    Zhu, Jia Ni; Weiland, Tracey J; Taylor, David M; Dent, Andrew W

    2008-05-05

    To describe how intern time is spent, and the frequency of activities performed by interns during emergency department (ED) rotations. Prospective observational study of 42 ED interns from three Melbourne city teaching hospitals during 5 months in 2006. Direct observations were made by a single researcher for 390.8 hours, sampling all days of the week and all hours of the day. Proportion of time spent on tasks and number of procedures performed or observed by interns. Direct patient-related tasks accounted for 86.6% of total intern time, including 43.9% spent on liaising and documentation, 17.5% obtaining patient histories, 9.3% on physical examinations, 5.6% on procedures, 4.8% ordering or interpreting investigations, 3.0% on handover and 4.9% on other clinical activities. Intern time spent on non-clinical activities included 4.2% on breaks, 3.7% on downtime, 1.7% on education, and 1.3% on teaching others. Adjusted for an 8-week term, the ED intern would take 253 patient histories, consult more senior ED staff on 683 occasions, perform 237 intravenous cannulations/phlebotomies, 39 arterial punctures, 12 wound repairs and apply 16 plasters. They would perform chest compressions under supervision on seven occasions, observe defibrillation twice and intubation once, but may not see a thoracostomy. The ED exposes interns to a broad range of activities. With the anticipated increase in intern numbers, dilution of the emergency medicine experience may occur, and requirements for supervision may increase. Substitution of ED rotations may deprive interns of a valuable learning experience.

  3. Time-lapse photogrammetry in geomorphic studies

    NASA Astrophysics Data System (ADS)

    Eltner, Anette; Kaiser, Andreas

    2017-04-01

    movement, and thus might be used as warning system in the case of natural hazards. A large variety of applications are suitable with time-lapse photogrammetry, i.e. change detection of all sorts; e.g. volumetric alterations, movement tracking or roughness changes. The multi-camera systems can be used for slope investigations, soil studies, glacier observation, snow cover measurement, volcanic surveillance or plant growth monitoring. A conceptual workflow is introduced highlighting the limits and potentials of time-lapse photogrammetry.

  4. Real-time observation of fluctuations at the driven-dissipative Dicke phase transition

    PubMed Central

    Brennecke, Ferdinand; Mottl, Rafael; Baumann, Kristian; Landig, Renate; Donner, Tobias; Esslinger, Tilman

    2013-01-01

    We experimentally study the influence of dissipation on the driven Dicke quantum phase transition, realized by coupling external degrees of freedom of a Bose–Einstein condensate to the light field of a high-finesse optical cavity. The cavity provides a natural dissipation channel, which gives rise to vacuum-induced fluctuations and allows us to observe density fluctuations of the gas in real-time. We monitor the divergence of these fluctuations over two orders of magnitude while approaching the phase transition, and observe a behavior that deviates significantly from that expected for a closed system. A correlation analysis of the fluctuations reveals the diverging time scale of the atomic dynamics and allows us to extract a damping rate for the external degree of freedom of the atoms. We find good agreement with our theoretical model including dissipation via both the cavity field and the atomic field. Using a dissipation channel to nondestructively gain information about a quantum many-body system provides a unique path to study the physics of driven-dissipative systems. PMID:23818599

  5. Simple bounds on fluctuations and uncertainty relations for first-passage times of counting observables

    NASA Astrophysics Data System (ADS)

    Garrahan, Juan P.

    2017-03-01

    Recent large deviation results have provided general lower bounds for the fluctuations of time-integrated currents in the steady state of stochastic systems. A corollary are so-called thermodynamic uncertainty relations connecting precision of estimation to average dissipation. Here we consider this problem but for counting observables, i.e., trajectory observables which, in contrast to currents, are non-negative and nondecreasing in time (and possibly symmetric under time reversal). In the steady state, their fluctuations to all orders are bound from below by a Conway-Maxwell-Poisson distribution dependent only on the averages of the observable and of the dynamical activity. We show how to obtain the corresponding bounds for first-passage times (times when a certain value of the counting variable is first reached) and their uncertainty relations. Just like entropy production does for currents, dynamical activity controls the bounds on fluctuations of counting observables.

  6. Observer Error when Measuring Safety-Related Behavior: Momentary Time Sampling versus Whole-Interval Recording

    ERIC Educational Resources Information Center

    Taylor, Matthew A.; Skourides, Andreas; Alvero, Alicia M.

    2012-01-01

    Interval recording procedures are used by persons who collect data through observation to estimate the cumulative occurrence and nonoccurrence of behavior/events. Although interval recording procedures can increase the efficiency of observational data collection, they can also induce error from the observer. In the present study, 50 observers were…

  7. Time requirements in performing body CT studies

    SciTech Connect

    Schoppe, W.D.; Hessel, S.J.; Adams, D.F.

    1981-08-01

    In computed tomography (CT), whole body examinations take 1.5 times as long as head studies. In 73 patients (11 thoracic studies, 25 abdominal examinations, 31 CT scans of abdomen and pelvis, and 6 examinations of pelvis alone), the average time for a CT study was 136 min. The active part of the procedure lasted 60 min. Seventy-six minutes were idle time. The physician's involvement in body CT was estimated to be 53 min for an average study, when scans were taken before and after administration of contrast material. There are time differences in body CT of various anatomic regions (thorax, 40 min; abdomen, 66 min; pelvic, 52 min). The complexity of body CT, the equipment of a CT department, and the approach to diagnosis are responsible for time requirements and physician's involvement in whole body CT.

  8. Observational study of children with aerophagia.

    PubMed

    Loening-Baucke, Vera; Swidsinski, Alexander

    2008-09-01

    Aerophagia is a rare disorder in children. The diagnosis is often delayed, especially when it occurs concomitantly with constipation. The aim of this report is to increase awareness about aerophagia. This study describes 2 girls and 7 boys, 2 to 10.4 years of age, with functional constipation and gaseous abdominal distention. The abdomen was visibly distended, nontender, and tympanitic in all. Documenting less distention on awakening helped to make the diagnosis. Air swallowing, belching, and flatulence were infrequently reported. The rectal examination often revealed a dilated rectal ampulla filled with gas or stool and gas. The abdominal X-ray showed gaseous distention of the colon in all and of the stomach and small bowel in 8 children. Treatment consisted of educating parents and children about air sucking and swallowing, encouraging the children to stop the excessive air swallowing, and suggesting to them not to use drinking straws and not to drink carbonated beverages. The aerophagia resolved in all in 2 to 20 months (mean=8 months).

  9. Real-time observations of stressful events in the operating room

    PubMed Central

    Sami, AlNassar; Waseem, Hajjar; Nourah, AlSubaie; Areej, AlHummaid; Afnan, AlMarshedi; Ghadeer, Al-Shaikh; Abdulaziz, AlSaif; Arthur, Isnani

    2012-01-01

    Aim: To identify and quantify factors causing stress in the operating room (OR) and evaluate the relationship between these factors and surgeons’ stress level. Methods: This is a prospective observational study from 32 elective surgical procedures conducted in the OR of King Khalid University Hospital, Riyadh, Saudi Arabia. Before each operation, each surgeon was asked of stressors. Two interns observed 16 surgeries each, separately. The interns watched and took notes during the entire surgical procedure. During each operation, the observer recorded anxiety-inducing activities and events that occurred in real time by means of a checklist of 8 potential stressors: technical, patient problems, teamwork problems, time and management issues, distractions and interruptions, equipment problems, personal problems, and teaching. After each operation, surgeons were asked to answer the validated State-Trait Anxiety Inventory questionnaire and self-report on their stress level from the 8 sources using a scale of 1–8 (1: stress free, 8: extremely stressful). The observer also recorded perceived stress levels experienced by the surgeons during the operation. Results: One hundred ten stressors were identified. Technical problems most frequently caused stress (16.4%) and personal issues the least often (6.4%). Frequently encountered stressors (teaching and distractions/interruptions) caused less stress to the surgeons. Technical factors, teamwork, and equipment problems occurred frequently and were also a major contributor to OR stress. All patients were discharged in good health and within 1 week of surgery. Conclusion: Certain stressful factors do occur among surgeons in the OR and can increase the potential for errors. Further research is required to determine the impact of stress on performance and the outcome of surgery. PMID:22754439

  10. Real-time observations of stressful events in the operating room.

    PubMed

    Sami, Alnassar; Waseem, Hajjar; Nourah, Alsubaie; Areej, Alhummaid; Afnan, Almarshedi; Ghadeer, Al-Shaikh; Abdulaziz, Alsaif; Arthur, Isnani

    2012-04-01

    To identify and quantify factors causing stress in the operating room (OR) and evaluate the relationship between these factors and surgeons' stress level. This is a prospective observational study from 32 elective surgical procedures conducted in the OR of King Khalid University Hospital, Riyadh, Saudi Arabia. Before each operation, each surgeon was asked of stressors. Two interns observed 16 surgeries each, separately. The interns watched and took notes during the entire surgical procedure. During each operation, the observer recorded anxiety-inducing activities and events that occurred in real time by means of a checklist of 8 potential stressors: technical, patient problems, teamwork problems, time and management issues, distractions and interruptions, equipment problems, personal problems, and teaching. After each operation, surgeons were asked to answer the validated State-Trait Anxiety Inventory questionnaire and self-report on their stress level from the 8 sources using a scale of 1-8 (1: stress free, 8: extremely stressful). The observer also recorded perceived stress levels experienced by the surgeons during the operation. One hundred ten stressors were identified. Technical problems most frequently caused stress (16.4%) and personal issues the least often (6.4%). Frequently encountered stressors (teaching and distractions/interruptions) caused less stress to the surgeons. Technical factors, teamwork, and equipment problems occurred frequently and were also a major contributor to OR stress. All patients were discharged in good health and within 1 week of surgery. Certain stressful factors do occur among surgeons in the OR and can increase the potential for errors. Further research is required to determine the impact of stress on performance and the outcome of surgery.

  11. Optimal time lags in panel studies.

    PubMed

    Dormann, Christian; Griffin, Mark A

    2015-12-01

    Cross-lagged regression coefficients are frequently used to test hypotheses in panel designs. However, these coefficients have particular properties making them difficult to interpret. In particular, cross-lagged regression coefficients may vary, depending on the respective time lags between different sets of measurement occasions. This article introduces the concept of an optimal time lag. Further, it is demonstrated that optimal time lags in panel studies are related to the stabilities of the variables investigated, and that in unidirectional systems, they may be unrelated to the size of possible true effects. The results presented also suggest that optimal time lags for panel designs are usually quite short. Implications are (a) that interpreting cross-lagged regression coefficients requires taking the time lag between measurement occasions into account, and (b) that in much research, far shorter time lags than those frequently found in the literature are justifiable, and we call for more "shortitudinal" studies in the future. (c) 2015 APA, all rights reserved).

  12. AB220. Relationships between intravaginal ejaculatory latency time and National Institutes of Health-Chronic Prostatitis Symptom Index in the four types of premature ejaculation syndromes: a large observational study in China

    PubMed Central

    Gao, Jingjing; Xu, Chuan; Zhang, Xiansheng

    2016-01-01

    Objective We assessed the associations between intravaginal ejaculatory latency time (IELT) and National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) in men with different PE syndromes. Methods From September 2011 to September 2012, a total of 4,000 men were enrolled from the Anhui province of China. Subjects were required to complete a verbal questionnaire, including demographic information, medical and sexual history (e.g., IELT), and self-estimated scales (e.g., NIH-CPSI). Results Of 3,016 of the men evaluated, 25.80% complained of premature ejaculation (PE). Distribution of the four PE syndromes among men with complaints of PE was as follows: LPE, 12.34%; APE, 18.77%; VPE, 44.09%; and SPE, 24.81%. Men with complaints of PE reported worse NIH-CPSI scores and lower IELT than men without complaints of PE (P<0.001 for all). Moreover, total and subdomain scores of NIH-CPSI were higher in men with APE, and IELT was higher in men with SPE. IELT was negatively associated with NIH-CPSI scores in men with complaints of PE. Negative relationships between total and subdomain scores of NIH-CPSI and IELT were stronger in men with APE (total scores: adjusted r=−0.68, P<0.001; pain symptoms: adjusted r=−0.70, P<0.001; urinary symptoms: adjusted r=−0.67, P<0.001; quality of life impact: adjusted r=−0.64, P<0.001). Conclusions Men with complaints of PE reported worse NIH-CPSI scores than men without complaints of PE. Relationships between IELT and NIH-CPSI scores were strongest in men with APE.

  13. Effect of Age of Self-Reported, Non-Surgical Menopause on Time to First Fracture and Bone Mineral Density in the Women’s Health Initiative Observational Study

    PubMed Central

    Lehman, Amy; Thomas, Fridtjof; Johnson, Karen C.; Jackson, Rebecca; Wactawski-Wende, Jean; Ko, Marcia; Chen, Zhao; Curb, J David; Howard, Barbara V.

    2015-01-01

    Objective Menopause is a risk factor for fracture, thus menopause age may affect bone mass and fracture rates. We compared Bone Mineral Density (BMD) and fracture rates among healthy postmenopausal women with varying ages of self-reported non-surgical menopause. Methods Hazard ratios for fracture and differences in BMD among 21,711 postmenopausal women from the Women’s Health Initiative Observational cohort without prior hysterectomy, oophorectomy, or hormone therapy, who reported age of menopause of <40, 40–49, or ≥50 years, were compared. Results Prior to multivariable adjustments, we found no differences in absolute fracture risk among menopausal age groups. After multivariable adjustments for known risk factors for fracture, women undergoing menopause <40 had a higher fracture risk at any site compared to women undergoing menopause ≥50 years (HR=1.21, 95% CI: 1.02, 1.44; p=0.03). In a subset with BMD measurements (n=1,351), whole body BMD was lower in women who reported menopause <40 compared to 40–49 years (estimated difference= −0.034 g/cm2; 95% CI: −0.07, −0.004; p=0.03) and compared to ≥50 years (estimated difference= −0.05 g/cm2; 95% CI; −0.08, −0.02; p<0.01). Left hip BMD was lower in women with menopause <40 compared to ≥50 years (estimated difference= −0.05 g/cm2; 95% CI: −0.08, −0.01; p=0.01), and total spine BMD was lower in women with menopause <40 compared to ≥50 and 40–49 years (estimated differences= −0.11 g/cm2; 95% CI; −0.16, −0.06; p<0.01 and −0.09 g/cm2; 95% CI; −0.15, −0.04; p<0.01, respectively). Conclusions In the absence of hormone therapy, earlier menopause age may be a risk factor contributing to decreased BMD and increased fracture risk in healthy postmenopausal women. Our data suggest that menopause age should be taken into consideration, along with other osteoporotic risk factors, when estimating fracture risk in postmenopausal women. PMID:25803670

  14. Observed Parent Behaviors as Time-Varying Moderators of Problem Behaviors Following Traumatic Brain Injury in Young Children

    ERIC Educational Resources Information Center

    Treble-Barna, Amery; Zang, Huaiyu; Zhang, Nanhua; Taylor, H. Gerry; Stancin, Terry; Yeates, Keith Owen; Wade, Shari L.

    2016-01-01

    Parent behaviors moderate the adverse consequences of pediatric traumatic brain injury (TBI); however, it is unknown how these moderating effects change over time. This study examined the moderating effect of observed parent behaviors over time since injury on the relation between TBI and behavioral outcomes. Participants included children, ages…

  15. Observed Parent Behaviors as Time-Varying Moderators of Problem Behaviors Following Traumatic Brain Injury in Young Children

    ERIC Educational Resources Information Center

    Treble-Barna, Amery; Zang, Huaiyu; Zhang, Nanhua; Taylor, H. Gerry; Stancin, Terry; Yeates, Keith Owen; Wade, Shari L.

    2016-01-01

    Parent behaviors moderate the adverse consequences of pediatric traumatic brain injury (TBI); however, it is unknown how these moderating effects change over time. This study examined the moderating effect of observed parent behaviors over time since injury on the relation between TBI and behavioral outcomes. Participants included children, ages…

  16. Algorithmic recognition of anomalous time intervals in sea-level observations

    NASA Astrophysics Data System (ADS)

    Getmanov, V. G.; Gvishiani, A. D.; Kamaev, D. A.; Kornilov, A. S.

    2016-03-01

    The problem of the algorithmic recognition of anomalous time intervals in the time series of the sea-level observations conducted by the Russian Tsunami Warning Survey (RTWS) is considered. The normal and anomalous sea-level observations are described. The polyharmonic models describing the sea-level fluctuations on the short time intervals are constructed, and sea-level forecasting based on these models is suggested. The algorithm for the recognition of anomalous time intervals is developed and its work is tested on the real RTWS data.

  17. Short-Time Glassy-like Dynamics Observed in Viscous Protein Solutions with Competing Potential Features

    NASA Astrophysics Data System (ADS)

    Wagner, Norman; Godfrin, Doug; Liu, Yun

    Structures in concentrated protein solutions caused by the combination of short-range attraction (SA) and long-range repulsion (LR) have been extensively studied due to their importance in understanding therapeutic protein formulations and the phase behavior in general. Despite extensive studies of kinetically arrested states in colloidal systems with short-range attraction, less is understood for the effect of an additional longer-range repulsion on model colloidal systems with a SA interaction. Highly purified lysozyme is used a model experimental system due to its stable globular structure and SALR interactions at low ionic strength that can be quantitatively modeled. The fluid microstructure and protein short time self diffusion are measured across a broad range of conditions by small angle neutron scattering (SANS) and neutron spin echo (NSE), respectively. Newtonian liquid behavior is observed at all concentrations, even with an increase of zero shear viscosity by almost four orders of magnitude with increasing concentration. However, dynamic measurements demonstrate a sub-diffusive regime at relatively short time scales for concentrated samples at low temperature. The formation of a heterogeneous density distribution is shown to produce localized regions of high density that reduce protein motion, giving it a glassy-like behavior at the short time scale. This heterogeneity occurs at the length scale associated with the intermediate range order driven by the competing potential features, distinguishable from heterogeneous colloidal gels.

  18. Magnetic Reconnection Sites Observed by the Cluster Spacecraft: Measurement of Short time scale electron effects

    NASA Astrophysics Data System (ADS)

    Buckley, A. M.; Carozzi, T. C.; Gough, M. P.; Chambers, E. C.

    Several events have been observed by the Cluster spacecraft passing close to magnetic reconnection sites in the tail and magnetopause when the fleet configuration is at short spatial scale (spacecraft separation approximately 100 km). These events are studied in the context of corresponding short time scale electron behaviour which contribute to and result from the reconnection process. This is done primarily using Particle Correlator data from the DWP instruments on Cluster in conjunction with other data sets. The particle correlators use captured time series of electron particle counts accumulated in 12 microsecond time bins measured over the energy range of the PEACE HEEA sensor (40 eV to 26 KeV) and on which an auto-correlation is performed. The phenomena studied concerns beam properties, electron acceleration, interaction with waves and any indications of the electron diffusion processes that are occurring. These phenomena are quantified using measures of the strength of particle-particle interactions (general second order statistics on the electrons) and the Index of Dispersion (variance to mean ratio) indicating bunching or scattering processes.

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

    NASA Technical Reports Server (NTRS)

    Clark, John

    1997-01-01

    This program was a one-year extension of an earlier Planetary Atmospheres program grant, covering the period 1 August 1996 through 30 September 1997. The grant was for supporting work to complement an active program observing planetary atmospheres with Earth-orbital telescopes, principally the Hubble Space Telescope (HST). The recent concentration of this work has been on HST observations of Jupiter's upper atmosphere and aurora, but it has also included observations of Io, serendipitous observations of asteroids, and observations of the velocity structure in the interplanetary medium. The observations of Jupiter have been at vacuum ultraviolet wavelengths, including imaging and spectroscopy of the auroral and airglow emissions. The most recent HST observations have been at the same time as in situ measurements made by the Galileo orbiter instruments, as reflected in the meeting presentations listed below. Concentrated efforts have been applied in this year to the following projects: The analysis of HST WFPC 2 images of Jupiter's aurora, including the Io footprint emissions. We have performed a comparative analysis of the lo footprint locations with two magnetic field models, studied the statistical properties of the apparent dawn auroral storms on Jupiter, and found various other repeated patterns in Jupiter's aurora. Analysis and modeling of airglow and auroral Ly alpha emission line profiles from Jupiter. This has included modeling the aurora] line profiles, including the energy degradation of precipitating charged particles and radiative transfer of the emerging emissions. Jupiter's auroral emission line profile is self-absorbed, since it is produced by an internal source, and the resulting emission with a deep central absorption from the overlying atmosphere permits modeling of the depth of the emissions, plus the motion of the emitting layer with respect to the overlying atmospheric column from the observed Doppler shift of the central absorption. By contrast

  20. A Time Allocation Study of University Faculty

    ERIC Educational Resources Information Center

    Link, Albert N.; Swann, Christopher A.; Bozeman, Barry

    2008-01-01

    Many previous time allocation studies treat work as a single activity and examine trade-offs between work and other activities. This paper investigates the at-work allocation of time among teaching, research, grant writing and service by science and engineering faculty at top US research universities. We focus on the relationship between tenure…

  1. Observation of quantum particles on a large space-time scale

    NASA Astrophysics Data System (ADS)

    Landau, L. J.

    1994-10-01

    A quantum particle observed on a sufficiently large space-time scale can be described by means of classical particle trajectories. The joint distribution for large-scale multiple-time position and momentum measurements on a nonrelativistic quantum particle moving freely in R v is given by straight-line trajectories with probabilities determined by the initial momentum-space wavefunction. For large-scale toroidal and rectangular regions the trajectories are geodesics. In a uniform gravitational field the trajectories are parabolas. A quantum counting process on free particles is also considered and shown to converge in the large-space-time limit to a classical counting process for particles with straight-line trajectories. If the quantum particle interacts weakly with its environment, the classical particle trajectories may undergo random jumps. In the random potential model considered here, the quantum particle evolves according to a reversible unitary one-parameter group describing elastic scattering off static randomly distributed impurities (a quantum Lorentz gas). In the large-space-time weak-coupling limit a classical stochastic process is obtained with probability one and describes a classical particle moving with constant speed in straight lines between random jumps in direction. The process depends only on the ensemble value of the covariance of the random field and not on the sample field. The probability density in phase space associated with the classical stochastic process satisfies the linear Boltzmann equation for the classical Lorentz gas, which, in the limit h→0, goes over to the linear Landau equation. Our study of the quantum Lorentz gas is based on a perturbative expansion and, as in other studies of this system, the series can be controlled only for small values of the rescaled time and for Gaussian random fields. The discussion of classical particle trajectories for nonrelativistic particles on a macroscopic spacetime scale applies also to

  2. Elevated time-dependent strengthening rates observed in San Andreas Fault drilling samples

    NASA Astrophysics Data System (ADS)

    Ikari, Matt J.; Carpenter, Brett M.; Vogt, Christoph; Kopf, Achim J.

    2016-09-01

    The central San Andreas Fault in California is known as a creeping fault, however recent studies have shown that it may be accumulating a slip deficit and thus its seismogenic potential should be seriously considered. We conducted laboratory friction experiments measuring time-dependent frictional strengthening (healing) on fault zone and wall rock samples recovered during drilling at the San Andreas Fault Observatory at Depth (SAFOD), located near the southern edge of the creeping section and in the direct vicinity of three repeating microearthquake clusters. We find that for hold times of up to 3000 s, frictional healing follows a log-linear dependence on hold time and that the healing rate is very low for a sample of the actively shearing fault core, consistent with previous results. However, considering longer hold times up to ∼350,000 s, the healing rate accelerates such that the data for all samples are better described by a power law relation. In general, samples having a higher content of phyllosilicate minerals exhibit low log-linear healing rates, and the notably clay-rich fault zone sample also exhibits strong power-law healing when longer hold times are included. Our data suggest that weak faults, such as the creeping section of the San Andreas Fault, can accumulate interseismic shear stress more rapidly than expected from previous friction data. Using the power-law dependence of frictional healing on hold time, calculations of recurrence interval and stress drop based on our data accurately match observations of discrete creep events and repeating Mw = 2 earthquakes on the San Andreas Fault.

  3. Study of Time Reversal in Complex Systems

    DTIC Science & Technology

    2014-01-02

    collapse in the time-reversed model; thus these distributions must be unique to each petal , as can be observed in figure 5. We will use the Flower ...in the simple case of a Flower machine having two time-reversed petals in figure 7 in section 2.3. 23 27 B.2 General case We wish to eliminate the...processes, using the conceptual formalism of the ?-machine. The causal irreversibility is examined, in particular for the class of Flower processes, and

  4. Nonlinear Estimation of Discrete-Time Signals Under Random Observation Delay

    SciTech Connect

    Caballero-Aguila, R.; Jimenez-Lopez, J. D.; Nakamori, S.

    2008-11-06

    This paper presents an approximation to the nonlinear least-squares estimation problem of discrete-time stochastic signals using nonlinear observations with additive white noise which can be randomly delayed by one sampling time. The observation delay is modelled by a sequence of independent Bernoulli random variables whose values, zero or one, indicate that the real observation arrives on time or it is delayed and, hence, the available measurement to estimate the signal is not up-to-date. Assuming that the state-space model generating the signal is unknown and only the covariance functions of the processes involved in the observation equation are ready for use, a filtering algorithm based on linear approximations of the real observations is proposed.

  5. Visual assessment of breast density using Visual Analogue Scales: observer variability, reader attributes and reading time

    NASA Astrophysics Data System (ADS)

    Ang, Teri; Harkness, Elaine F.; Maxwell, Anthony J.; Lim, Yit Y.; Emsley, Richard; Howell, Anthony; Evans, D. Gareth; Astley, Susan; Gadde, Soujanya

    2017-03-01

    Breast density is a strong risk factor for breast cancer and has potential use in breast cancer risk prediction, with subjective methods of density assessment providing a strong relationship with the development of breast cancer. This study aims to assess intra- and inter-observer variability in visual density assessment recorded on Visual Analogue Scales (VAS) among trained readers, and examine whether reader age, gender and experience are associated with assessed density. Eleven readers estimated the breast density of 120 mammograms on two occasions 3 years apart using VAS. Intra- and inter-observer agreement was assessed with Intraclass Correlation Coefficient (ICC) and variation between readers visualised on Bland-Altman plots. The mean scores of all mammograms per reader were used to analyse the effect of reader attributes on assessed density. Excellent intra-observer agreement (ICC>0.80) was found in the majority of the readers. All but one reader had a mean difference of <10 percentage points from the first to the second reading. Inter-observer agreement was excellent for consistency (ICC 0.82) and substantial for absolute agreement (ICC 0.69). However, the 95% limits of agreement for pairwise differences were -6.8 to 15.7 at the narrowest and 0.8 to 62.3 at the widest. No significant association was found between assessed density and reader age, experience or gender, or with reading time. Overall, the readers were consistent in their scores, although some large variations were observed. Reader evaluation and targeted training may alleviate this problem.

  6. Combining satellite observations to develop a global soil moisture product for near-real-time applications

    NASA Astrophysics Data System (ADS)

    Enenkel, Markus; Reimer, Christoph; Dorigo, Wouter; Wagner, Wolfgang; Pfeil, Isabella; Parinussa, Robert; De Jeu, Richard

    2016-10-01

    The soil moisture dataset that is generated via the Climate Change Initiative (CCI) of the European Space Agency (ESA) (ESA CCI SM) is a popular research product. It is composed of observations from 10 different satellites and aims to exploit the individual strengths of active (radar) and passive (radiometer) sensors, thereby providing surface soil moisture estimates at a spatial resolution of 0.25°. However, the annual updating cycle limits the use of the ESA CCI SM dataset for operational applications. Therefore, this study proposes an adaptation of the ESA CCI product for daily global updates via satellite-derived near-real-time (NRT) soil moisture observations. In order to extend the ESA CCI SM dataset from 1978 to present we use NRT observations from the Advanced Scatterometer on-board the two MetOp satellites and the Advanced Microwave Scanning Radiometer 2 on-board GCOM-W. Since these NRT observations do not incorporate the latest algorithmic updates, parameter databases and intercalibration efforts, by nature they offer a lower quality than reprocessed offline datasets. In addition to adaptations of the ESA CCI SM processing chain for NRT datasets, the quality of the NRT datasets is a main source of uncertainty. Our findings indicate that, despite issues in arid regions, the new CCI NRT dataset shows a good correlation with ESA CCI SM. The average global correlation coefficient between CCI NRT and ESA CCI SM (Pearson's R) is 0.80. An initial validation with 40 in situ observations in France, Spain, Senegal and Kenya yields an average R of 0.58 and 0.49 for ESA CCI SM and CCI NRT, respectively. In summary, the CCI NRT product is nearly as accurate as the existing ESA CCI SM product and, therefore, of significant value for operational applications such as drought and flood forecasting, agricultural index insurance or weather forecasting.

  7. Preliminary Space VLBI Requirements for Observing Time on Ground Radio Telescopes

    NASA Technical Reports Server (NTRS)

    Meier, David L.; Murphy, David W.; Preston, Robert A.

    1992-01-01

    An initial estimate has been made of the observing time required on ground radio telescopes by the space VLBI missions Radioastron and VSOP. Typical science programs have been adopted for both missions.

  8. Learning Approaches, Study Time and Academic Performance.

    ERIC Educational Resources Information Center

    Kember, David; And Others

    1995-01-01

    Investigation of the study habits and approaches to study tasks of 34 mechanical engineering students over the course of 1 week found that use of a surface approach to learning was positively correlated with high class attendance and greater study time, suggesting an inefficient approach. The research methodology used is found useful for…

  9. Coordinated Regional Benefit Studies of Coastal Ocean Observing Systems

    DTIC Science & Technology

    2003-01-01

    Ocean observing systems are a primary source of this information. Science Education and Communication: Real-time data from ocean observing systems...can be used to enhance science education in the classroom and can bring benefits directly to users of ocean observing information, such as

  10. Time-resolved visible/near-infrared spectrometric observations of the Galaxy 11 geostationary satellite

    NASA Astrophysics Data System (ADS)

    Bédard, Donald; Wade, Gregg A.

    2017-01-01

    Time-resolved spectrometric measurements of the Galaxy 11 geostationary satellite were collected on three consecutive nights in July 2014 with the 1.6-m telescope at the Observatoire du Mont-Mégantic in Québec, Canada. Approximately 300 low-resolution spectra (R ≈ 700 , where R = λ / Δλ) of the satellite were collected each night, covering a spectral range between 425 and 850 nm. The two objectives of the experiment were to conduct material-type identification from the spectra and to study how the spectral energy distribution inferred from these measurements varied as the illumination and observation geometry changed on nightly timescales. We present results that indicate the presence of a highly reflective aluminized surface corresponding to the solar concentrator arrays of the Galaxy 11 spacecraft. Although other material types could not be identified using the spectra, the results showed that the spectral energy distribution of the reflected sunlight from the Galaxy 11 spacecraft varied significantly, in a systematic manner, over each night of observation. The variations were quantified using colour indices calculated from the time-resolved spectrometric measurements.

  11. Parameterizing time in electronic health record studies.

    PubMed

    Hripcsak, George; Albers, David J; Perotte, Adler

    2015-07-01

    Fields like nonlinear physics offer methods for analyzing time series, but many methods require that the time series be stationary-no change in properties over time.Objective Medicine is far from stationary, but the challenge may be able to be ameliorated by reparameterizing time because clinicians tend to measure patients more frequently when they are ill and are more likely to vary. We compared time parameterizations, measuring variability of rate of change and magnitude of change, and looking for homogeneity of bins of temporal separation between pairs of time points. We studied four common laboratory tests drawn from 25 years of electronic health records on 4 million patients. We found that sequence time-that is, simply counting the number of measurements from some start-produced more stationary time series, better explained the variation in values, and had more homogeneous bins than either traditional clock time or a recently proposed intermediate parameterization. Sequence time produced more accurate predictions in a single Gaussian process model experiment. Of the three parameterizations, sequence time appeared to produce the most stationary series, possibly because clinicians adjust their sampling to the acuity of the patient. Parameterizing by sequence time may be applicable to association and clustering experiments on electronic health record data. A limitation of this study is that laboratory data were derived from only one institution. Sequence time appears to be an important potential parameterization. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and

  12. Annual report of the Mizusawa Astrogeodynamics Observatory. Time Service and geophysical observations for the year 1991.

    NASA Astrophysics Data System (ADS)

    This annual report consists of two parts. The first part shows the results of the time services, i.e., time and latitude observations with the PZT, comparison of UTC(NAOM) with the Loran C and GPS (Global Positioning System), and comparison of the atomic clocks at the Mizusawa Astrogeodynamics Observatory. The second part shows the results of the geophysical observations at the Esashi Earth Tides Station and the absolute gravity measurements.

  13. CAN LARGE TIME DELAYS OBSERVED IN LIGHT CURVES OF CORONAL LOOPS BE EXPLAINED IN IMPULSIVE HEATING?

    SciTech Connect

    Lionello, Roberto; Linker, Jon A.; Mikić, Zoran; Alexander, Caroline E.; Winebarger, Amy R. E-mail: linkerj@predsci.com E-mail: caroline.e.alexander@nasa.gov

    2016-02-20

    The light curves of solar coronal loops often peak first in channels associated with higher temperatures and then in those associated with lower temperatures. The delay times between the different narrowband EUV channels have been measured for many individual loops and recently for every pixel of an active region observation. The time delays between channels for an active region exhibit a wide range of values. The maximum time delay in each channel pair can be quite large, i.e., >5000 s. These large time delays make-up 3%–26% (depending on the channel pair) of the pixels where a trustworthy, positive time delay is measured. It has been suggested that these time delays can be explained by simple impulsive heating, i.e., a short burst of energy that heats the plasma to a high temperature, after which the plasma is allowed to cool through radiation and conduction back to its original state. In this paper, we investigate whether the largest observed time delays can be explained by this hypothesis by simulating a series of coronal loops with different heating rates, loop lengths, abundances, and geometries to determine the range of expected time delays between a set of four EUV channels. We find that impulsive heating cannot address the largest time delays observed in two of the channel pairs and that the majority of the large time delays can only be explained by long, expanding loops with photospheric abundances. Additional observations may rule out these simulations as an explanation for the long time delays. We suggest that either the time delays found in this manner may not be representative of real loop evolution, or that the impulsive heating and cooling scenario may be too simple to explain the observations, and other potential heating scenarios must be explored.

  14. Improved geophysical excitations constrained by polar motion observations and GRACE/SLR time-dependent gravity

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Li, Jiancheng; Ray, Jim; Cheng, Minkang

    2017-04-01

    At seasonal and intraseasonal time scales, polar motions are mainly excited by angular momentum fluctuations due to mass redistributions and relative motions in the atmosphere, oceans, and continental water, snow, and ice, which are usually provided by various global atmospheric, oceanic, and hydrological models (some with meteorological observations assimilated; e.g., NCEP, ECCO, ECMWF, OMCT and LSDM etc.). Unfortunately, these model outputs are far from perfect and have notable discrepancies with respect to polar motion observations, due to non-uniform distributions of meteorological observatories, as well as theoretical approximations and non-global mass conservation in these models. In this study, the Least Difference Combination (LDC) method are adopted to obtain some improved atmospheric, oceanic, and hydrological/crospheric angular momentum (AAM, OAM and HAM/CAM, respectively) functions and excitation functions (termed as the LDCgsm solutions). Various GRACE (Gravity Recovery and Climate Experiment) and SLR (Satellite Laser Ranging) geopotential data are adopted to correct the non-global mass conservation problem, while polar motion data are used as general constraints. The LDCgsm solutions can reveal not only periodic fluctuations but also secular trends in AAM, OAM and HAM/CAM, and are in better agreement with polar motion observations, reducing the unexplained excitation to the level of 5 mas (standard derivation value; about 1/5 - 1/4 of those corresponding to the original model outputs).

  15. Is plant community richness regulated over time? Contrasting results from experiments and long-term observations.

    PubMed

    Elmendorf, Sarah C; Harrison, Susan P

    2011-03-01

    There is considerable debate among ecologists as to whether or not communities are saturated. In saturated communities, species richness should remain relatively constant over time, despite compositional turnover, because richness is negatively correlated with colonization and positively correlated with local extinction. Few studies have tested for saturation using temporal observational data as well as diversity-perturbation experiments. We analyzed 10 years of data for plant species richness at 71 sites on contrasting serpentine and non-serpentine soils within Californian (USA) grasslands. We also manipulated local richness and measured its effects on immigration and extinction. Consistent with saturation, we observed that richness was positively correlated with extinction rates and negatively correlated with colonization rates, and randomization tests confirmed that diversity fluctuated less than expected by chance. However, experimental species additions and removals did not affect extinction or colonization, suggesting that richness is not regulated by local species interactions. Instead, we propose three reasons why richness may fluctuate within narrow limits causing the appearance of saturation in temporal observational data sets: negatively autocorrelated patterns of biotic response to yearly conditions, differential affinities of particular species for local conditions, or stochastic abundance-dependent colonization and extinction rates. We illustrate the latter using a metacommunity model.

  16. 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.

  17. First Observation of Low Energy Electron Neutrinos in a Liquid Argon Time Projection Chamber

    SciTech Connect

    Acciarri, R.; et al.

    2016-10-13

    Liquid argon time projection chambers (LArTPCs) produce remarkable fidelity in the observation of neutrino interactions. The superior capabilities of such detectors to reconstruct the spatial and calorimetric information of neutrino events have made them the detectors of choice in a number of experiments, specifically those looking to observe electron neutrino ($\

  18. Distributional behaviors of time-averaged observables in the Langevin equation with fluctuating diffusivity: Normal diffusion but anomalous fluctuations

    NASA Astrophysics Data System (ADS)

    Akimoto, Takuma; Yamamoto, Eiji

    2016-06-01

    We consider the Langevin equation with dichotomously fluctuating diffusivity, where the diffusion coefficient changes dichotomously over time, in order to study fluctuations of time-averaged observables in temporally heterogeneous diffusion processes. We find that the time-averaged mean-square displacement (TMSD) can be represented by the occupation time of a state in the asymptotic limit of the measurement time and hence occupation time statistics is a powerful tool for calculating the TMSD in the model. We show that the TMSD increases linearly with time (normal diffusion) but the time-averaged diffusion coefficients are intrinsically random when the mean sojourn time for one of the states diverges, i.e., intrinsic nonequilibrium processes. Thus, we find that temporally heterogeneous environments provide anomalous fluctuations of time-averaged diffusivity, which have relevance to large fluctuations of the diffusion coefficients obtained by single-particle-tracking trajectories in experiments.

  19. Gamma-Ray Burst Arrival Time Localizations: Simultaneous Observations by Mars Observer, Compton Gamma Ray Observatory and Ulysses

    NASA Technical Reports Server (NTRS)

    Laros, J. G.; Boynton, W. V.; Hurley, K.; Kouveliotou, C.; McCollough, M. L.; Fishman, G. J.; Meegan, C. A.

    1997-01-01

    Between 1992 October 4 and 1993 August 1, concurrent coverage by the Compton Gamma Ray Observatory (CGRO), Mars Observer (MO), and Ulysses spacecraft was obtained for 78 gamma-ray bursts (GRBs). Although most of these were below the MO and Ulysses thresholds, nine were positively detected by all three spacecraft, with data quality adequate for quantitative localization analysis. All were localized independently to approximately 2 deg accuracy by the CGRO Burst and Transient Source Experiment (BATSE). We computed arrival-time error boxes with larger dimensions ranging from a few arcminutes to the diameters of the BATSE-only boxes and with smaller dimensions in the arcminute range. Three events are of particular interest: GB 930704 (BATSE 2428) has been described as a possible repeater. The arrival-time information is consistent with that hypothesis, but only just so. The GB 930706 (2431) box, at approximately 1 min x 4 min, is the only one this small obtained since Pioneer Venus Orbiter (PVO) entered the Venusian atmosphere in 1992 October. Sensitive radio and optical observations of this location were made within 8 and 9 days of the burst, but no counterpart candidates were identified. GB 930801 (2477) is the first GRB that had its localization improved by taking into account BATSE Earth occultation.

  20. Direct mapping rather than motor prediction subserves modulation of corticospinal excitability during observation of actions in real time.

    PubMed

    Gueugneau, Nicolas; Mc Cabe, Sofia I; Villalta, Jorge I; Grafton, Scott T; Della-Maggiore, Valeria

    2015-06-01

    Motor facilitation refers to the specific increment in corticospinal excitability (CSE) elicited by the observation of actions performed by others. To date, the precise nature of the mechanism at the basis of this phenomenon is unknown. One possibility is that motor facilitation is driven by a predictive process reminiscent of the role of forward models in motor control. Alternatively, motor facilitation may result from a model-free mechanism by which the basic elements of the observed action are directly mapped onto their cortical representations. Our study was designed to discern these alternatives. To this aim, we recorded the time course of CSE for the first dorsal interosseous (FDI) and the abductor digiti minimi (ADM) during observation of three grasping actions in real time, two of which strongly diverged in kinematics from their natural (invariant) form. Although artificially slow movements used in most action observation studies might enhance the observer's discrimination performance, the use of videos in real time is crucial to maintain the time course of CSE within the physiological range of daily actions. CSE was measured at 4 time points within a 240-ms window that best captured the kinematic divergence from the invariant form. Our results show that CSE of the FDI, not the ADM, closely follows the functional role of the muscle despite the mismatch between the natural and the divergent kinematics. We propose that motor facilitation during observation of actions performed in real time reflects the model-free coding of perceived movement following a direct mapping mechanism.

  1. Assessing the Impact of Different Measurement Time Intervals on Observed Long-Term Wind Speed Trends

    NASA Astrophysics Data System (ADS)

    Azorin-Molina, C.; Vicente-Serrano, S. M.; McVicar, T.; Jerez, S.; Revuelto, J.; López Moreno, J. I.

    2014-12-01

    During the last two decades climate studies have reported a tendency toward a decline in measured near-surface wind speed in some regions of Europe, North America, Asia and Australia. This weakening in observed wind speed has been recently termed "global stilling", showing a worldwide average trend of -0.140 m s-1 dec-1 during last 50-years. The precise cause of the "global stilling" remains largely uncertain and has been hypothetically attributed to several factors, mainly related to: (i) an increasing surface roughness (i.e. forest growth, land use changes, and urbanization); (ii) a slowdown in large-scale atmospheric circulation; (iii) instrumental drifts and technological improvements, maintenance, and shifts in measurements sites and calibration issues; (iv) sunlight dimming due to air pollution; and (v) astronomical changes. This study proposed a novel investigation aimed at analyzing how different measurement time intervals used to calculate a wind speed series can affect the sign and magnitude of long-term wind speed trends. For instance, National Weather Services across the globe estimate daily average wind speed using different time intervals and formulae that may affect the trend results. Firstly, we carried out a comprehensive review of wind studies reporting the sign and magnitude of wind speed trend and the sampling intervals used. Secondly, we analyzed near-surface wind speed trends recorded at 59 land-based stations across Spain comparing monthly mean wind speed series obtained from: (a) daily mean wind speed data averaged from standard 10-min mean observations at 0000, 0700, 1300 and 1800 UTC; and (b) average wind speed of 24 hourly measurements (i.e., wind run measurements) from 0000 to 2400 UTC. Thirdly and finally, we quantified the impact of anemometer drift (i.e. bearing malfunction) by presenting preliminary results (1-year of paired measurements) from a comparison of one new anemometer sensor against one malfunctioned anenometer sensor due

  2. Collaborative real-time motion video analysis by human observer and image exploitation algorithms

    NASA Astrophysics Data System (ADS)

    Hild, Jutta; Krüger, Wolfgang; Brüstle, Stefan; Trantelle, Patrick; Unmüßig, Gabriel; Heinze, Norbert; Peinsipp-Byma, Elisabeth; Beyerer, Jürgen

    2015-05-01

    Motion video analysis is a challenging task, especially in real-time applications. In most safety and security critical applications, a human observer is an obligatory part of the overall analysis system. Over the last years, substantial progress has been made in the development of automated image exploitation algorithms. Hence, we investigate how the benefits of automated video analysis can be integrated suitably into the current video exploitation systems. In this paper, a system design is introduced which strives to combine both the qualities of the human observer's perception and the automated algorithms, thus aiming to improve the overall performance of a real-time video analysis system. The system design builds on prior work where we showed the benefits for the human observer by means of a user interface which utilizes the human visual focus of attention revealed by the eye gaze direction for interaction with the image exploitation system; eye tracker-based interaction allows much faster, more convenient, and equally precise moving target acquisition in video images than traditional computer mouse selection. The system design also builds on prior work we did on automated target detection, segmentation, and tracking algorithms. Beside the system design, a first pilot study is presented, where we investigated how the participants (all non-experts in video analysis) performed in initializing an object tracking subsystem by selecting a target for tracking. Preliminary results show that the gaze + key press technique is an effective, efficient, and easy to use interaction technique when performing selection operations on moving targets in videos in order to initialize an object tracking function.

  3. 5 CFR 550.1002 - Compensatory time off for religious observances.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... personal religious beliefs require the abstention from work during certain periods of time may elect to... religious observances when the employee's personal religious beliefs require that the employee abstain from... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Compensatory time off for...

  4. 5 CFR 550.1002 - Compensatory time off for religious observances.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... personal religious beliefs require the abstention from work during certain periods of time may elect to... religious observances when the employee's personal religious beliefs require that the employee abstain from... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Compensatory time off for...

  5. Contributions of long-term research and time-series observations to marine ecology and biogeochemistry.

    PubMed

    Ducklow, Hugh W; Doney, Scott C; Steinberg, Deborah K

    2009-01-01

    Time-series observations form a critical element of oceanography. New interdisciplinary efforts launched in the past two decades complement the few earlier, longer-running time series to build a better, though still poorly resolved, picture of lower-frequency ocean variability, the climate processes that drive variability, and the implications for food web dynamics, carbon storage, and climate feedbacks. Time series also enlarge our understanding of ecological processes and are integral for improving models of physical-biogeochemical-ecological ocean dynamics. The major time-series observatories go well beyond simple monitoring of core ocean properties, although that important activity forms the critical center of all time-series efforts. Modern ocean time series have major process and experimental components, entrain ancillary programs, and have integrated modeling programs for deriving a better understanding of the observations and the changing, three-dimensional ocean in which the observatories are embedded.

  6. A Design Method for Pole Placement and Observer of Linear Time-Varying Discrete MIMO Systems

    NASA Astrophysics Data System (ADS)

    Mutoh, Yasuhiko; Hara, Tomohiro

    It is well known that, the pole placement controller can be designing for linear time-varying systems using the Frobenius canonical form, as for the time invariant case. This paper presents the new approach to the design of the pole placement controller for linear time-varying discrete multivariable systems. The concept of the relative degrees of multivariable system plays an important role, and the time-varying feedback gain can be simply calculated without transforming the system into any canonical form, which is regarded as a discrete Ackerman's method. This method is applied in order to calculate the observer gain for linear time-varying systems.

  7. Techniques for measuring arrival times of pulsar signals 1: DSN observations from 1968 to 1980

    NASA Technical Reports Server (NTRS)

    Downs, G. S.; Reichley, P. E.

    1980-01-01

    Techniques used in the ground based observations of pulsars are described, many of them applicable in a navigation scheme. The arrival times of the pulses intercepting Earth are measured at time intervals from a few days to a few months. Low noise, wide band receivers, amplify signals intercepted by 26 m, 34, and 64 m antennas. Digital recordings of total received signal power versus time are cross correlated with the appropriate pulse template.

  8. Effects of action observation on corticospinal excitability: Muscle specificity, direction, and timing of the mirror response.

    PubMed

    Naish, Katherine R; Houston-Price, Carmel; Bremner, Andrew J; Holmes, Nicholas P

    2014-11-01

    Many human behaviours and pathologies have been attributed to the putative mirror neuron system, a neural system that is active during both the observation and execution of actions. While there are now a very large number of papers on the mirror neuron system, variations in the methods and analyses employed by researchers mean that the basic characteristics of the mirror response are not clear. This review focuses on three important aspects of the mirror response, as measured by modulations in corticospinal excitability: (1) muscle specificity; (2) direction; and (3) timing of modulation. We focus mainly on electromyographic (EMG) data gathered following single-pulse transcranial magnetic stimulation (TMS), because this method provides precise information regarding these three aspects of the response. Data from paired-pulse TMS paradigms and peripheral nerve stimulation (PNS) are also considered when we discuss the possible mechanisms underlying the mirror response. In this systematic review of the literature, we examine the findings of 85 TMS and PNS studies of the human mirror response, and consider the limitations and advantages of the different methodological approaches these have adopted in relation to discrepancies between their findings. We conclude by proposing a testable model of how action observation modulates corticospinal excitability in humans. Specifically, we propose that action observation elicits an early, non-specific facilitation of corticospinal excitability (at around 90ms from action onset), followed by a later modulation of activity specific to the muscles involved in the observed action (from around 200ms). Testing this model will greatly advance our understanding of the mirror mechanism and provide a more stable grounding on which to base inferences about its role in human behaviour.

  9. Using radiative kernels to compare feedback behavior over different time scales in CMIP output and observations

    NASA Astrophysics Data System (ADS)

    Shell, K. M.; Flink, M. M.; Jonko, A. K.

    2011-12-01

    Accurate climate projections require an understanding of feedback behavior on centennial timescales. Unfortunately, satellite and reanalysis observations are available only for the last few decades. We seek to determine the extent to which the relatively short observation-based records can constrain model estimates of long-term (century-scale) climate change in response to anthropogenic forcing. The radiative kernel technique allows us to study feedbacks related to temperature, water vapor, surface albedo, and clouds in a consistent fashion. We are using Coupled Model Intercomparison Project (CMIP) simulations to determine whether (modeled) feedbacks differ for interannual- and decadal-scale versus centennial-scale climate change. We also are comparing short-term feedbacks derived from satellite (Atmospheric Infrared Sounder, AIRS) and reanalysis (ERA-Interim) data with modeled feedbacks. We use two strategies. The first is the standard kernel technique where feedbacks are determined by differencing mean variables between two states. Preliminary work with CMIP3 indicates that averaging periods (e.g., 10 years versus 20 years) can change feedback estimates by more 20%. In general, we expect longer averaging periods to result in more accurate estimates of feedbacks. However, transient GCMs runs (as well as observational data sets) may be only a few decades long. In these cases, we must determine the best averaging period to balance the increase of noise caused by a shorter averaging period and the decrease of climate signal resulting from averaging periods that are closer together. To address this issue, the second strategy is a modified kernel technique where anomalies from the mean climate are combined with the kernel for every month of the time series. This technique is more appropriate in cases where there is not a large external forcing. We are calculating feedbacks in the CMIP5 simulations using both strategies with different averaging periods and start

  10. Timing and regional patterns of snowmelt on Antarctic sea ice from passive microwave satellite observations

    NASA Astrophysics Data System (ADS)

    Arndt, Stefanie; Willmes, Sascha; Dierking, Wolfgang; Nicolaus, Marcel

    2016-04-01

    The better understanding of temporal variability and regional distribution of surface melt on Antarctic sea ice is crucial for the understanding of atmosphere-ocean interactions and the determination of mass and energy budgets of sea ice. Since large regions of Antarctic sea ice are covered with snow during most of the year, observed inter-annual and regional variations of surface melt mainly represents melt processes in the snow. It is therefore important to understand the mechanisms that drive snowmelt, both at different times of the year and in different regions around Antarctica. In this study we combine two approaches for observing both surface and volume snowmelt by means of passive microwave satellite data. The former is achieved by measuring diurnal differences of the brightness temperature TB at 37 GHz, the latter by analyzing the ratio TB(19GHz)/TB(37GHz). Moreover, we use both melt onset proxies to divide the Antarctic sea ice cover into characteristic surface melt patterns from 1988/89 to 2014/15. Our results indicate four characteristic melt types. On average, 43% of the ice-covered ocean shows diurnal freeze-thaw cycles in the surface snow layer, resulting in temporary melt (Type A), less than 1% shows continuous snowmelt throughout the snowpack, resulting in strong melt over a period of several days (Type B), 19% shows Type A and B taking place consecutively (Type C), and for 37% no melt is observed at all (Type D). Continuous melt is primarily observed in the outflow of the Weddell Gyre and in the northern Ross Sea, usually 20 days after the onset of temporary melt. Considering the entire data set, snowmelt processes and onset do not show significant temporal trends. Instead, areas of increasing (decreasing) sea-ice extent have longer (shorter) periods of continuous snowmelt.

  11. Real-time observation of the conformational dynamics of mitochondrial Hsp70 by spFRET

    PubMed Central

    Sikor, Martin; Mapa, Koyeli; von Voithenberg, Lena Voith; Mokranjac, Dejana; Lamb, Don C

    2013-01-01

    The numerous functions of the important class of molecular chaperones, heat shock proteins 70 (Hsp70), rely on cycles of intricate conformational changes driven by ATP-hydrolysis and regulated by cochaperones and substrates. Here, we used Förster resonance energy transfer to study the conformational dynamics of individual molecules of Ssc1, a mitochondrial Hsp70, in real time. The intrinsic dynamics of the substrate-binding domain of Ssc1 was observed to be uncoupled from the dynamic interactions between substrate- and nucleotide-binding domains. Analysis of the fluctuations in the interdomain separation revealed frequent transitions to a nucleotide-free state. The nucleotide-exchange factor Mge1 did not induce ADP release, as expected, but rather facilitated binding of ATP. These results indicate that the conformational cycle of Ssc1 is more elaborate than previously thought and provide insight into how the Hsp70s can perform a wide variety of functions. PMID:23624933

  12. Real-time observation of the conformational dynamics of mitochondrial Hsp70 by spFRET.

    PubMed

    Sikor, Martin; Mapa, Koyeli; von Voithenberg, Lena Voith; Mokranjac, Dejana; Lamb, Don C

    2013-05-29

    The numerous functions of the important class of molecular chaperones, heat shock proteins 70 (Hsp70), rely on cycles of intricate conformational changes driven by ATP-hydrolysis and regulated by cochaperones and substrates. Here, we used Förster resonance energy transfer to study the conformational dynamics of individual molecules of Ssc1, a mitochondrial Hsp70, in real time. The intrinsic dynamics of the substrate-binding domain of Ssc1 was observed to be uncoupled from the dynamic interactions between substrate- and nucleotide-binding domains. Analysis of the fluctuations in the interdomain separation revealed frequent transitions to a nucleotide-free state. The nucleotide-exchange factor Mge1 did not induce ADP release, as expected, but rather facilitated binding of ATP. These results indicate that the conformational cycle of Ssc1 is more elaborate than previously thought and provide insight into how the Hsp70s can perform a wide variety of functions.

  13. Observation of Time-Invariant Coherence in a Nuclear Magnetic Resonance Quantum Simulator

    NASA Astrophysics Data System (ADS)

    Silva, Isabela A.; Souza, Alexandre M.; Bromley, Thomas R.; Cianciaruso, Marco; Marx, Raimund; Sarthour, Roberto S.; Oliveira, Ivan S.; Lo Franco, Rosario; Glaser, Steffen J.; deAzevedo, Eduardo R.; Soares-Pinto, Diogo O.; Adesso, Gerardo

    2016-10-01

    The ability to live in coherent superpositions is a signature trait of quantum systems and constitutes an irreplaceable resource for quantum-enhanced technologies. However, decoherence effects usually destroy quantum superpositions. It was recently predicted that, in a composite quantum system exposed to dephasing noise, quantum coherence in a transversal reference basis can stay protected for an indefinite time. This can occur for a class of quantum states independently of the measure used to quantify coherence, and it requires no control on the system during the dynamics. Here, such an invariant coherence phenomenon is observed experimentally in two different setups based on nuclear magnetic resonance at room temperature, realizing an effective quantum simulator of two- and four-qubit spin systems. Our study further reveals a novel interplay between coherence and various forms of correlations, and it highlights the natural resilience of quantum effects in complex systems.

  14. Real-time observation of FIB-created dots and ripples on GaAs.

    PubMed

    Rose, F; Fujita, H; Kawakatsu, H

    2008-01-23

    We report a phenomenological study of Ga dots and ripples created by a focused ion beam (FIB) on the GaAs(001) surface. Real-time observation of dot diffusion and ripple formation was made possible by recording FIB movies. In the case of FIB irradiation with a 40 nA current of Ga(+) ions accelerated under 40 kV with an incidence angle of θ = 30°, increasing ion dose gives rise to three different regimes. In Regime 1, dots with lateral sizes in the range 50-460 nm are formed. Dots diffuse under continuous sputtering. In Regime 2, dots self-assemble into Bradley and Harper (BH) type ripples with a pseudo-period of λ = 1150 ± 25 nm. In Regime 3, ripples are eroded and the surface topology evolves into microplanes. In the case of normal incidence, FIB sputtering leads only to the formation of dots, without surface rippling.

  15. Observation of Time-Invariant Coherence in a Nuclear Magnetic Resonance Quantum Simulator.

    PubMed

    Silva, Isabela A; Souza, Alexandre M; Bromley, Thomas R; Cianciaruso, Marco; Marx, Raimund; Sarthour, Roberto S; Oliveira, Ivan S; Lo Franco, Rosario; Glaser, Steffen J; deAzevedo, Eduardo R; Soares-Pinto, Diogo O; Adesso, Gerardo

    2016-10-14

    The ability to live in coherent superpositions is a signature trait of quantum systems and constitutes an irreplaceable resource for quantum-enhanced technologies. However, decoherence effects usually destroy quantum superpositions. It was recently predicted that, in a composite quantum system exposed to dephasing noise, quantum coherence in a transversal reference basis can stay protected for an indefinite time. This can occur for a class of quantum states independently of the measure used to quantify coherence, and it requires no control on the system during the dynamics. Here, such an invariant coherence phenomenon is observed experimentally in two different setups based on nuclear magnetic resonance at room temperature, realizing an effective quantum simulator of two- and four-qubit spin systems. Our study further reveals a novel interplay between coherence and various forms of co