Two-actor conflict with time delay: A dynamical model

NASA Astrophysics Data System (ADS)

Qubbaj, Murad R.; Muneepeerakul, Rachata

2012-11-01

Recent mathematical dynamical models of the conflict between two different actors, be they nations, groups, or individuals, have been developed that are capable of predicting various outcomes depending on the chosen feedback strategies, initial conditions, and the previous states of the actors. In addition to these factors, this paper examines the effect of time delayed feedback on the conflict dynamics. Our analysis shows that under certain initial and feedback conditions, a stable neutral equilibrium of conflict may destabilize for some critical values of time delay, and the two actors may evolve to new emotional states. We investigate the results by constructing critical delay surfaces for different sets of parameters and analyzing results from numerical simulations. These results provide new insights regarding conflict and conflict resolution and may help planners in adjusting and assessing their strategic decisions.

Investigation of the delay time distribution of high power microwave surface flashover

NASA Astrophysics Data System (ADS)

Foster, J.; Krompholz, H.; Neuber, A.

2011-01-01

Characterizing and modeling the statistics associated with the initiation of gas breakdown has proven to be difficult due to a variety of rather unexplored phenomena involved. Experimental conditions for high power microwave window breakdown for pressures on the order of 100 to several 100 torr are complex: there are little to no naturally occurring free electrons in the breakdown region. The initial electron generation rate, from an external source, for example, is time dependent and so is the charge carrier amplification in the increasing radio frequency (RF) field amplitude with a rise time of 50 ns, which can be on the same order as the breakdown delay time. The probability of reaching a critical electron density within a given time period is composed of the statistical waiting time for the appearance of initiating electrons in the high-field region and the build-up of an avalanche with an inherent statistical distribution of the electron number. High power microwave breakdown and its delay time is of critical importance, since it limits the transmission through necessary windows, especially for high power, high altitude, low pressure applications. The delay time distribution of pulsed high power microwave surface flashover has been examined for nitrogen and argon as test gases for pressures ranging from 60 to 400 torr, with and without external UV illumination. A model has been developed for predicting the discharge delay time for these conditions. The results provide indications that field induced electron generation, other than standard field emission, plays a dominant role, which might be valid for other gas discharge types as well.

Timely response to secure messages from primary care patients.

PubMed

Rohrer, James E; North, Frederick; Angstman, Kurt B; Oberhelman, Sara S; Meunier, Matthew R

2013-01-01

To assess delays in response to patient secure e-mail messages in primary care. Secure electronic messages are initiated by primary care patients. Timely response is necessary for patient safety and quality. A database of secure messages. A random sample of 353 secure electronic messages initiated by primary care patients treated in 4 clinics. Message not opened after 12 hours or messages not responded to after 36 hours. A total of 8.5% of electronic messages were not opened within 12 hours, and 17.6% did not receive a response in 36 hours. Clinic location, being a clinic employee, and patient sex were not related to delays. Patients older than 50 years were more likely to receive a delayed response (25.7% delayed, P = .013). The risk of both kinds of delays was higher on weekends (P < .001 for both). The e-mail message system resulted in high rates of delayed response. Delays were concentrated on weekends (Friday-Sunday). Reducing delayed responses may require automatic rerouting of messages to message centers staffed 24-7 or other mechanisms to manage this after-hours work flow.

DELAY on first antenatal care visit and its associated factors among pregnant women in public health facilities of Debre Markos town, North West Ethiopia.

PubMed

Ewunetie, Atsede Alle; Munea, Alemtsehay Mekonnen; Meselu, Belsity Temesgen; Simeneh, Muluye Molla; Meteku, Bekele Tesfaye

2018-05-16

Delay on timely initiation of antenatal care has a great impact on adverse pregnancy out comes. However, evidences in Ethiopia revealed that majority of pregnant mothers did not start their first visit as recommrnded by WHO. The aim of this study was to assess delay and associated factors of first antenatal care visit among pregnant mothers at public health facilities of Debremarkos town, North West Ethiopia. An institutional based crosss-sectional study was conducted from February to March, 2014 in public health facilities of Debremarkos town North west Ethiopia. A total of 320 pregnant mothers who were sure of their last menstrual periods were interviewed with a structured questionnaire. Data entry was done using Epi data 3.1 and analysis was done using SPSS version 20. Descriptive statistics, binary and multivariable logistic regression analyses were employed to identify the magnitude and factors associated with delay on timely initiation of the first antenatal care visit. The proportion of respondents who made their first antenatal care visit after 16 weeks of gestation was found to be 33.4%. Mothers residing in rural settings (AOR = 2.8 [95% CI:1.54-5.44]), not attained formal education(AOR = 2.2 [95% CI:1.10-4.68]),with unintended pregnancy (AOR = 3.6 [95% CI:2.00-6.80]) and who perceived that the right initiation time of the first antenatal care visit is beyond 16 weeks of gestation (AOR = 3.9 [95% CI:1.61-9.76]) were more likely delayed on their first antenatal care visit . Residence, educational status, intention of pregnancy and perception on the right time of first antenatal care visit initiation were found to be predictors of delay on timely initiatin of first antenatal care visit. Therefore, the Zonal health department should strengthen awareness creation about timely initiation of first antenatal care visit and family planning to prevent unintended pregnancy in the community especially in the rural settings.

Delayed antimicrobial therapy increases mortality and organ dysfunction duration in pediatric sepsis.

PubMed

Weiss, Scott L; Fitzgerald, Julie C; Balamuth, Fran; Alpern, Elizabeth R; Lavelle, Jane; Chilutti, Marianne; Grundmeier, Robert; Nadkarni, Vinay M; Thomas, Neal J

2014-11-01

Delayed antimicrobials are associated with poor outcomes in adult sepsis, but data relating antimicrobial timing to mortality and organ dysfunction in pediatric sepsis are limited. We sought to determine the impact of antimicrobial timing on mortality and organ dysfunction in pediatric patients with severe sepsis or septic shock. Retrospective observational study. PICU at an academic medical center. One hundred thirty patients treated for severe sepsis or septic shock. None. We determined if hourly delays from sepsis recognition to initial and first appropriate antimicrobial administration were associated with PICU mortality (primary outcome); ventilator-free, vasoactive-free, and organ failure-free days; and length of stay. Median time from sepsis recognition to initial antimicrobial administration was 140 minutes (interquartile range, 74-277 min) and to first appropriate antimicrobial was 177 minutes (90-550 min). An escalating risk of mortality was observed with each hour delay from sepsis recognition to antimicrobial administration, although this did not achieve significance until 3 hours. For patients with more than 3-hour delay to initial and first appropriate antimicrobials, the odds ratio for PICU mortality was 3.92 (95% CI, 1.27-12.06) and 3.59 (95% CI, 1.09-11.76), respectively. These associations persisted after adjustment for individual confounders and a propensity score analysis. After controlling for severity of illness, the odds ratio for PICU mortality increased to 4.84 (95% CI, 1.45-16.2) and 4.92 (95% CI, 1.30-18.58) for more than 3-hour delay to initial and first appropriate antimicrobials, respectively. Initial antimicrobial administration more than 3 hours was also associated with fewer organ failure-free days (16 [interquartile range, 1-23] vs 20 [interquartile range, 6-26]; p = 0.04). Delayed antimicrobial therapy was an independent risk factor for mortality and prolonged organ dysfunction in pediatric sepsis.

Delayed Antimicrobial Therapy Increases Mortality and Organ Dysfunction Duration in Pediatric Sepsis

PubMed Central

Weiss, Scott L.; Fitzgerald, Julie C.; Balamuth, Fran; Alpern, Elizabeth R.; Lavelle, Jane; Chilutti, Marianne; Grundmeier, Robert; Nadkarni, Vinay M.; Thomas, Neal J.

2014-01-01

Objectives Delayed antimicrobials are associated with poor outcomes in adult sepsis, but data relating antimicrobial timing to mortality and organ dysfunction in pediatric sepsis are limited. We sought to determine the impact of antimicrobial timing on mortality and organ dysfunction in pediatric patients with severe sepsis or septic shock. Design Retrospective observational study. Setting PICU at an academic medical center. Patients One hundred thirty patients treated for severe sepsis or septic shock. Interventions None. Measurements and Main Results We determined if hourly delays from sepsis recognition to initial and first appropriate antimicrobial administration were associated with PICU mortality (primary outcome); ventilator-free, vasoactive-free, and organ failure–free days; and length of stay. Median time from sepsis recognition to initial antimicrobial administration was 140 minutes (interquartile range, 74–277 min) and to first appropriate antimicrobial was 177 minutes (90–550 min). An escalating risk of mortality was observed with each hour delay from sepsis recognition to antimicrobial administration, although this did not achieve significance until 3 hours. For patients with more than 3-hour delay to initial and first appropriate antimicrobials, the odds ratio for PICU mortality was 3.92 (95% CI, 1.27–12.06) and 3.59 (95% CI, 1.09–11.76), respectively. These associations persisted after adjustment for individual confounders and a propensity score analysis. After controlling for severity of illness, the odds ratio for PICU mortality increased to 4.84 (95% CI, 1.45–16.2) and 4.92 (95% CI, 1.30–18.58) for more than 3-hour delay to initial and first appropriate antimicrobials, respectively. Initial antimicrobial administration more than 3 hours was also associated with fewer organ failure–free days (16 [interquartile range, 1–23] vs 20 [interquartile range, 6–26]; p = 0.04). Conclusions Delayed antimicrobial therapy was an independent risk factor for mortality and prolonged organ dysfunction in pediatric sepsis. PMID:25148597

Independence of Movement Preparation and Movement Initiation.

PubMed

Haith, Adrian M; Pakpoor, Jina; Krakauer, John W

2016-03-09

Initiating a movement in response to a visual stimulus takes significantly longer than might be expected on the basis of neural transmission delays, but it is unclear why. In a visually guided reaching task, we forced human participants to move at lower-than-normal reaction times to test whether normal reaction times are strictly necessary for accurate movement. We found that participants were, in fact, capable of moving accurately ∼80 ms earlier than their reaction times would suggest. Reaction times thus include a seemingly unnecessary delay that accounts for approximately one-third of their duration. Close examination of participants' behavior in conventional reaction-time conditions revealed that they generated occasional, spontaneous errors in trials in which their reaction time was unusually short. The pattern of these errors could be well accounted for by a simple model in which the timing of movement initiation is independent of the timing of movement preparation. This independence provides an explanation for why reaction times are usually so sluggish: delaying the mean time of movement initiation relative to preparation reduces the risk that a movement will be initiated before it has been appropriately prepared. Our results suggest that preparation and initiation of movement are mechanistically independent and may have a distinct neural basis. The results also demonstrate that, even in strongly stimulus-driven tasks, presentation of a stimulus does not directly trigger a movement. Rather, the stimulus appears to trigger an internal decision whether to make a movement, reflecting a volitional rather than reactive mode of control. Copyright © 2016 the authors 0270-6474/16/363007-10$15.00/0.

Impact of uneven sample morphology on mass resolving power in linear MALDI-TOF mass spectrometry: A comprehensive theoretical investigation.

PubMed

Cai, Yi-Hong; Wang, Yi-Sheng

2018-04-01

This work discusses the correlation between the mass resolving power of matrix-assisted laser desorption/ionization time-of-flight mass analyzers and extraction condition with an uneven sample morphology. Previous theoretical calculations show that the optimum extraction condition for flat samples involves an ideal ion source design and extraction delay. A general expression of spectral feature takes into account ion initial velocity, and extraction delay is derived in the current study. The new expression extends the comprehensive calculation to uneven sample surfaces and above 90% Maxell-Boltzmann initial velocity distribution of ions to account for imperfect ionization condition. Calculation shows that the impact of uneven sample surface or initial spatial spread of ions is negligible when the extraction delay is away from the ideal value. When the extraction delay approaches the optimum value, the flight-time topology shows a characteristic curve shape, and the time-domain mass spectral feature broadens with an increase in initial spatial spread of ions. For protonated 2,5-dihydroxybenzoic acid, the mass resolving power obtained from a sample of 3-μm surface roughness is approximately 3.3 times lower than that of flat samples. For ions of m/z 3000 coexpanded with 2,5-dihydroxybenzoic acid, the mass resolving power in the 3-μm surface roughness case only reduces roughly 7%. Comprehensive calculations also show that the mass resolving power of lighter ions is more sensitive to the accuracy of the extraction delay than heavier ions. Copyright © 2018 John Wiley & Sons, Ltd.

Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting.

PubMed

Negash, Sesen; Sheppard, Nicole Van Ness; Lambert, Nathaniel M; Fincham, Frank D

2016-01-01

Internet pornography is a multi-billion-dollar industry that has grown increasingly accessible. Delay discounting involves devaluing larger, later rewards in favor of smaller, more immediate rewards. The constant novelty and primacy of sexual stimuli as particularly strong natural rewards make Internet pornography a unique activator of the brain's reward system, thereby having implications for decision-making processes. Based on theoretical studies of evolutionary psychology and neuroeconomics, two studies tested the hypothesis that consuming Internet pornography would relate to higher rates of delay discounting. Study 1 used a longitudinal design. Participants completed a pornography use questionnaire and a delay discounting task at Time 1 and then again four weeks later. Participants reporting higher initial pornography use demonstrated a higher delay discounting rate at Time 2, controlling for initial delay discounting. Study 2 tested for causality with an experimental design. Participants were randomly assigned to abstain from either their favorite food or pornography for three weeks. Participants who abstained from pornography use demonstrated lower delay discounting than participants who abstained from their favorite food. The finding suggests that Internet pornography is a sexual reward that contributes to delay discounting differently than other natural rewards. Theoretical and clinical implications of these studies are highlighted.

Effects of point massage of liver and stomach channel combined with pith and trotter soup on postpartum lactation start time.

PubMed

Luo, Qiong; Hu, Yin; Zhang, Hui

2017-10-01

Delay in lactation initiation causes maternal anxiety and subsequent adverse impact on maternal exclusive breast feeding. It is important to explore a safe and convenient way to promote lactation initiation. The feasibility of point massage of liver and stomach channel combined with pith and trotter soup on prevention of delayed lactation initiation was investigated in the present study. 320 women were enrolled and randomly divided into four groups, control group (80 women), point massage group (80 women), pith and trotter soup group (80 women), and massage + soup group (80 women) to compare the lactation initiation time. We found that women in point massage group, pith and trotter soup group and massage + soup group had earlier initiation of lactation compared with control group. Women in massage + soup group had the earliest initiation time of lactation. There were significant differences between massage + soup group and pith and trotter soup group. But, there were no significant differences between massage + soup group and massage group. We conclude that point massage of the liver and stomach channel is easy to operate and has the preventive effect on delayed lactation initiation. Impact statement What is already known on this subject: Initiation of lactation is a critical period in postpartum milk secretion. Delays in lactation initiation lead to maternal anxiety and have an adverse impact on maternal exclusive breastfeeding. Sucking frequently by babies and mammary massage might be effective but insufficient for delayed lactation initiation. What the results of this study add: We found in the present study that lactation initiation is significantly earlier in women receiving routine nursing combined with point massage of liver and stomach channel, or pith trotters soup, or massage of liver and stomach channel with pith and trotters soup than in a control group receiving routine nursing. These three methods are all effective, while the most effective method is point massage combined with pith trotter soup. There was no maternal drug allergy, postpartum bleeding or other adverse reactions noted in all women. What the implications are of these findings for clinical practice and/or further research: The present study suggested that the application of point massage in clinic might be useful for preventing lack of milk postpartum by delayed lactation initiation and improving the exclusive breastfeeding rate. Further research might explore that molecular mechanism of lactation promotion by point massage using blood samples or animal models.

Objective measures of sleep and dim light melatonin onset in adolescents and young adults with delayed sleep phase disorder compared to healthy controls.

PubMed

Saxvig, Ingvild W; Wilhelmsen-Langeland, Ane; Pallesen, Ståle; Vedaa, Oystein; Nordhus, Inger H; Sørensen, Eli; Bjorvatn, Bjørn

2013-08-01

Delayed sleep phase disorder is characterized by a delay in the timing of the major sleep period relative to conventional norms. The sleep period itself has traditionally been described as normal. Nevertheless, it is possible that sleep regulatory mechanism disturbances associated with the disorder may affect sleep duration and/or architecture. Polysomnographic data that may shed light on the issue are scarce. Hence, the aim of this study was to examine polysomnographic measures of sleep in adolescents and young adults with delayed sleep phase disorder, and to compare findings to that of healthy controls. A second aim was to estimate dim light melatonin onset as a marker of circadian rhythm and to investigate the phase angle relationship (time interval) between dim light melatonin onset and the sleep period. Data from 54 adolescents and young adults were analysed, 35 diagnosed with delayed sleep phase disorder and 19 healthy controls. Results show delayed timing of sleep in participants with delayed sleep phase disorder, but once sleep was initiated no group differences in sleep parameters were observed. Dim light melatonin onset was delayed in participants with delayed sleep phase disorder, but no difference in phase angle was observed between the groups. In conclusion, both sleep and dim light melatonin onset were delayed in participants with delayed sleep phase disorder. The sleep period appeared to occur at the same circadian phase in both groups, and once sleep was initiated no differences in sleep parameters were observed. © 2013 European Sleep Research Society.

Teachers' generalized use of delay as a stimulus control procedure to increase language use in handicapped children.

PubMed Central

Halle, J W; Baer, D M; Spradlin, J E

1981-01-01

In Experiment 1, classroom teachers were taught to delay their offers of help in naturally occurring situations, and thereby to provide additional opportunities for language use by six moderately retarded language-delayed children. The teachers introduced this delay technique in a multiple-baseline design across the six children. As delays were used, child verbal initiations increased. Follow-up assessment showed that teachers were maintaining greater than baseline levels of the delay technique after 10 weeks. Experiment 2 replicated the findings of Experiment 1, and included a more thorough maintenance assessment, while focusing on teachers' generalization of the delay technique. Teachers were found to generalize their use of delay to 56% of their monitored untaught opportunities. The two experiments show that (a) the delay technique is quick to teach and simple to implement, (b) delays do provide opportunities for children to initiate, (c) teachers can generalize their use of delay to novel self-selected situations, and (d) teachers can maintain their use of delays over time. PMID:6460019

System for sensing droplet formation time delay in a flow cytometer

DOEpatents

Van den Engh, Ger; Esposito, Richard J.

1997-01-01

A droplet flow cytometer system which includes a system to optimize the droplet formation time delay based on conditions actually experienced includes an automatic droplet sampler which rapidly moves a plurality of containers stepwise through the droplet stream while simultaneously adjusting the droplet time delay. Through the system sampling of an actual substance to be processed can be used to minimize the effect of the substances variations or the determination of which time delay is optimal. Analysis such as cell counting and the like may be conducted manually or automatically and input to a time delay adjustment which may then act with analysis equipment to revise the time delay estimate actually applied during processing. The automatic sampler can be controlled through a microprocessor and appropriate programming to bracket an initial droplet formation time delay estimate. When maximization counts through volume, weight, or other types of analysis exists in the containers, the increment may then be reduced for a more accurate ultimate setting. This may be accomplished while actually processing the sample without interruption.

Study on statistical breakdown delay time in argon gas using a W-band millimeter-wave gyrotron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dongsung; Yu, Dongho; Choe, MunSeok

2016-04-15

In this study, we investigated plasma initiation delay times for argon volume breakdown at the W-band frequency regime. The threshold electric field is defined as the minimum electric field amplitude needed for plasma breakdown at various pressures. The measured statistical delay time showed an excellent agreement with the theoretical Gaussian distribution and the theoretically estimated formative delay time. Also, we demonstrated that the normalized effective electric field as a function of the product of pressure and formative time shows an outstanding agreement to that of 1D particle-in-cell simulation coupled with a Monte Carlo collision model [H. C. Kim and J.more » P. Verboncoeur, Phys. Plasmas 13, 123506 (2006)].« less

An evaluation of in-office flexible fiber-optic biopsies for laryngopharyngeal lesions.

PubMed

Lee, Francisco; Smith, Kristine A; Chandarana, Shamir; Matthews, T Wayne; Bosch, J Douglas; Nakoneshny, Steven C; Dort, Joseph C

2018-05-09

Operative endoscopy and flexible fiber-optic in-office tissue biopsy are common techniques to assess suspicious laryngopharyngeal lesions. The primary outcome was the delay to the initiation of treatment. Secondary outcomes were delay to biopsy, histopathological diagnosis, and assessment at a multidisciplinary oncology clinic. A retrospective analysis was performed to assess the relative delays between these approaches to biopsy of laryngopharyngeal lesions. There were 114 patients in the study cohort; 44 in-office and 70 operative endoscopic biopsies). The mean delay from consultation to biopsy was 17.4 days for the operative endoscopy group and 1.3 days for the in-office group. The mean delay from initial otolaryngology consultation to initiation of treatment was 51.7 days and 44.6 days for the operative endoscopy and in-office groups, respectively. In-office biopsy reduced the time from initial consultation to biopsy. The temporal gains via in-office biopsy did not translate into faster access to treatment. This outcome highlights the opportunity to improve access to treatment for patients with early diagnosis.

Estimation of time- and state-dependent delays and other parameters in functional differential equations

NASA Technical Reports Server (NTRS)

Murphy, K. A.

1988-01-01

A parameter estimation algorithm is developed which can be used to estimate unknown time- or state-dependent delays and other parameters (e.g., initial condition) appearing within a nonlinear nonautonomous functional differential equation. The original infinite dimensional differential equation is approximated using linear splines, which are allowed to move with the variable delay. The variable delays are approximated using linear splines as well. The approximation scheme produces a system of ordinary differential equations with nice computational properties. The unknown parameters are estimated within the approximating systems by minimizing a least-squares fit-to-data criterion. Convergence theorems are proved for time-dependent delays and state-dependent delays within two classes, which say essentially that fitting the data by using approximations will, in the limit, provide a fit to the data using the original system. Numerical test examples are presented which illustrate the method for all types of delay.

Estimation of time- and state-dependent delays and other parameters in functional differential equations

NASA Technical Reports Server (NTRS)

Murphy, K. A.

1990-01-01

A parameter estimation algorithm is developed which can be used to estimate unknown time- or state-dependent delays and other parameters (e.g., initial condition) appearing within a nonlinear nonautonomous functional differential equation. The original infinite dimensional differential equation is approximated using linear splines, which are allowed to move with the variable delay. The variable delays are approximated using linear splines as well. The approximation scheme produces a system of ordinary differential equations with nice computational properties. The unknown parameters are estimated within the approximating systems by minimizing a least-squares fit-to-data criterion. Convergence theorems are proved for time-dependent delays and state-dependent delays within two classes, which say essentially that fitting the data by using approximations will, in the limit, provide a fit to the data using the original system. Numerical test examples are presented which illustrate the method for all types of delay.

Delayed Presentation of Ureteropelvic Junction Obstruction and Loss of Renal Function After Initially Mild (SFU Grade 1-2) Hydronephrosis.

PubMed

Bowen, Diana K; Yerkes, Elizabeth B; Lindgren, Bruce W; Gong, Edward M; Faasse, Mark A

2015-07-01

We report 4 pediatric cases of ureteropelvic junction obstruction involving delayed progression of initially mild postnatal hydronephrosis. All 4 children became symptomatic; however, 3 already had a substantial decrement of ipsilateral kidney function by the time of diagnosis. Two of these 3 patients had previous renal scintigraphy demonstrating normal differential function. We caution that counseling regarding hydronephrosis should emphasize the importance of prompt re-evaluation for any symptoms potentially referable to delayed presentation of ureteropelvic junction obstruction, irrespective of initial hydronephrosis grade. Future studies are needed to determine the optimal follow-up regimen for conservative management of hydronephrosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Delays before Diagnosis and Initiation of Treatment in Patients Presenting to Mental Health Services with Bipolar Disorder.

PubMed

Patel, Rashmi; Shetty, Hitesh; Jackson, Richard; Broadbent, Matthew; Stewart, Robert; Boydell, Jane; McGuire, Philip; Taylor, Matthew

2015-01-01

Bipolar disorder is a significant cause of morbidity and mortality. Although existing treatments are effective, there is often a substantial delay before diagnosis and treatment initiation. We sought to investigate factors associated with the delay before diagnosis of bipolar disorder and the onset of treatment in secondary mental healthcare. Retrospective cohort study using anonymised electronic mental health record data from the South London and Maudsley NHS Foundation Trust (SLaM) Biomedical Research Centre (BRC) Case Register on 1364 adults diagnosed with bipolar disorder between 2007 and 2012. The following predictor variables were analysed in a multivariable Cox regression analysis: age, gender, ethnicity, compulsory admission to hospital under the UK Mental Health Act, marital status and other diagnoses prior to bipolar disorder. The outcomes were time to recorded diagnosis from first presentation to specialist mental health services (the diagnostic delay), and time to the start of appropriate therapy (treatment delay). The median diagnostic delay was 62 days (interquartile range: 17-243) and median treatment delay was 31 days (4-122). Compulsory hospital admission was associated with a significant reduction in both diagnostic delay (hazard ratio 2.58, 95% CI 2.18-3.06) and treatment delay (4.40, 3.63-5.62). Prior diagnoses of other psychiatric disorders were associated with increased diagnostic delay, particularly alcohol (0.48, 0.33-0.41) and substance misuse disorders (0.44, 0.31-0.61). Prior diagnosis of schizophrenia and psychotic depression were associated with reduced treatment delay. Some individuals experience a significant delay in diagnosis and treatment of bipolar disorder after initiation of specialist mental healthcare, particularly those who have prior diagnoses of alcohol and substance misuse disorders. These findings highlight a need for further study on strategies to better identify underlying symptoms and offer appropriate treatment sooner in order to facilitate improved clinical outcomes, such as developing specialist early intervention services to identify and treat people with bipolar disorder.

Factors That Facilitate Or Hinder Fuel-Saving Initiatives and Technology

DTIC Science & Technology

2015-12-01

loading times, unloading times, prevailing winds , flying times, and such other factors as air traffic control delay times, taxi delay times, and...just the simple vehicle telematics used, which is the sensors and so on, the driver behavior telematics. There’s things like the communication module...electric, compressed natural gas, and even turbine -powered vehicles (Interview FE02, July 2, 2015). As early as 2003, the company was looking to replace

Robust fixed-time synchronization of delayed Cohen-Grossberg neural networks.

PubMed

Wan, Ying; Cao, Jinde; Wen, Guanghui; Yu, Wenwu

2016-01-01

The fixed-time master-slave synchronization of Cohen-Grossberg neural networks with parameter uncertainties and time-varying delays is investigated. Compared with finite-time synchronization where the convergence time relies on the initial synchronization errors, the settling time of fixed-time synchronization can be adjusted to desired values regardless of initial conditions. Novel synchronization control strategy for the slave neural network is proposed. By utilizing the Filippov discontinuous theory and Lyapunov stability theory, some sufficient schemes are provided for selecting the control parameters to ensure synchronization with required convergence time and in the presence of parameter uncertainties. Corresponding criteria for tuning control inputs are also derived for the finite-time synchronization. Finally, two numerical examples are given to illustrate the validity of the theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.

The relevance of timing in nonconvulsive status epilepticus: A series of 38 cases.

PubMed

Gutiérrez-Viedma, Álvaro; Parejo-Carbonell, Beatriz; Cuadrado, María-Luz; Serrano-García, Irene; Abarrategui, Belén; García-Morales, Irene

2018-05-01

Timing in the management of nonconvulsive status epilepticus (NCSE) seems to be one of the most important modifiable prognostic factors. We aimed to determine the precise relationship between timing in NCSE management and its outcome. We performed a cross-sectional study in which clinical data were prospectively obtained from all consecutive adults with NCSE admitted to our hospital from 2014 to 2016. Univariate and multivariable regression analyses were performed to identify clinical and timing variables associated with NCSE prognosis. Among 38 NCSE cases, 59.9% were women, and 39.5% had prior epilepsy history. The median time to treatment (TTT) initiation and the median time to assessment by a neurologist (TTN) were 5h, and the median time to first electroencephalography assessment was 18.5h; in the cases with out-of-hospital onset (n=24), the median time to hospital (TTH) arrival was 2.8h. The median time to NCSE control (TTC) was 16.5h, and it positively correlated with both the TTH (Spearman's rho: 0.439) and the TTT (Spearman's rho: 0.683). In the multivariable regression analyses, the TTC was extended 1.7h for each hour of hospital arrival delay (p=0.01) and 2.7h for each hour of treatment delay (p<0.001). Recognition delay was more common in the episodes with in-hospital onset, which also had longer TTN and TTC, and increased morbidity. There were pervasive delays in all phases of NCSE management. Delays in hospital arrival or treatment initiation may result in prolonged TTC. Recognition of in-hospital episodes may be more delayed, which may lead to poorer prognosis in these cases. Copyright © 2018 Elsevier Inc. All rights reserved.

Basins of attraction of the bistable region of time-delayed cutting dynamics

NASA Astrophysics Data System (ADS)

Yan, Yao; Xu, Jian; Wiercigroch, Marian

2017-09-01

This paper investigates the effects of bistability in a nonsmooth time-delayed dynamical system, which is often manifested in science and engineering. Previous studies on cutting dynamics have demonstrated persistent coexistence of chatter and chatter-free responses in a bistable region located in the linearly stable zone. As there is no widely accepted definition of basins of attraction for time-delayed systems, bistable regions are coined as unsafe zones (UZs). Hence, we have attempted to define the basins of attraction and stability basins for a typical delayed system to get insight into the bistability in systems with time delays. Special attention was paid to the influences of delayed initial conditions, starting points, and states at time zero on the long-term dynamics of time-delayed systems. By using this concept, it has been confirmed that the chatter is prone to occur when the waviness frequency in the workpiece surface coincides with the effective natural frequency of the cutting process. Further investigations unveil a thin "boundary layer" inside the UZ in the immediate vicinity of the stability boundary, in which we observe an extremely fast growth of the chatter basin stability. The results reveal that the system is more stable when the initial cutting depth is smaller. The physics of the tool deflection at the instant of the tool-workpiece engagement is used to evaluate the cutting safety, and the safe level could be zero when the geometry of tool engagement is unfavorable. Finally, the basins of attraction are used to quench the chatter by a single strike, where the resultant "islands" offer an opportunity to suppress the chatter even when the cutting is very close to the stability boundary.

Delayed Diagnosis in Duchenne Muscular Dystrophy: Data from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet)

PubMed Central

Ciafaloni, Emma; Fox, Deborah J.; Pandya, Shree; Westfield, Christina P.; Puzhankara, Soman; Romitti, Paul A.; Mathews, Katherine D.; Miller, Timothy M.; Matthews, Dennis J.; Miller, Lisa A.; Cunniff, Christopher; Druschel, Charlotte M.; Moxley, Richard T.

2018-01-01

Objective To identify key factors for the delay in diagnosis of Duchenne muscular dystrophy (DMD) without known family history. Study design The cohort comes from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet), a multistate, multiple-source, population-based surveillance system that identifies and gathers information on all cases of Duchenne and Becker muscular dystrophy born since 1982. We analyzed medical records of 453 Duchenne and Becker muscular dystrophy boys to document the time course and steps taken to reach a definitive diagnosis. Results Among 156 boys without known family history of DMD prior to birth, first signs or symptoms were noted at a mean age of 2.5 years. Concerns resulted in primary care provider evaluation of the child at a mean age of 3.6 years. Mean age at time of initial creatine kinase was 4.7 years. Mean age at definitive diagnosis of DMD was 4.9 years. Conclusions There is a delay of about 2.5 years between onset of DMD symptoms and the time of definitive diagnosis, unchanged over the previous 2 decades. This delay results in lost opportunities for timely genetic counseling and initiation of corticosteroid treatment. We recommend checking creatine kinase early in the evaluation of boys with unexplained developmental delay. PMID:19394035

Delay in initiation of treatment after diagnosis of pulmonary tuberculosis in primary health care setting: eight year cohort analysis from district Faridabad, Haryana, North India.

PubMed

Kant, Shashi; Singh, Arvind K; Parmeshwaran, Giridara G; Haldar, Partha; Malhotra, Sumit; Kaur, Ravneet

2017-01-01

Delay in initiation of tuberculosis (TB) treatment may have a tremendous impact on disease transmission, development of drug resistance, poor outcome and overall survival of TB patients. The delay can occur at various levels. Delay in initiation of treatment after diagnosis is mostly due to health system failure and has immense programmatic implications. It has not been studied extensively in the Indian setting. The authors did a cohort analysis of all TB patients initiated on treatment from two primary health centres (PHCs) at Ballabgarh Health and Demographic Surveillance System between January 2007 and December 2014. Diagnosis and treatment of TB in the study area was done as per the protocol envisaged in the national program. Information related to demography, details of diagnosis and treatment of TB and outcome of treatment were extracted from the TB register. Delay in initiation of treatment after diagnosis was considered if the gap between diagnosis and treatment was greater than 7 days. Bivariate and multivariate analyses were done to find the association of various factors with delay in initiation of treatment after diagnosis. Out of 885 patients, 662 patients started treatment for pulmonary TB. Mean time interval between diagnosis and initiation of treatment was 8.95 days. Only 57.7% of pulmonary TB patients were started on treatment within 7 days of diagnosis, and an additional 24.5% were started on treatment 8-14 days after diagnosis. Patients on retreatment regimens and those residing in villages without a PHC were more likely to have delayed initiation of treatment (odds ratio (OR)=1.82 (1.3-2.7, p=0.001) and OR=1.62 (1.1-2.5, p=0.01) respectively). Delay in initiation of treatment was also associated with unfavourable treatment outcome such as default, failure or death. There is a need to have healthcare changes related to TB care to enable initiation of treatment as early as possible. Pretreatment counselling especially for retreatment patients is of utmost importance.

Patient and health service delay in pulmonary tuberculosis patients attending a referral hospital: a cross-sectional study.

PubMed

Kiwuwa, Mpungu S; Charles, Karamagi; Harriet, Mayanja Kizza

2005-11-24

Delays in diagnosis and initiation of effective treatment increase morbidity and mortality from tuberculosis as well as the risk of transmission in the community. The aim of this study was to determine the time taken for patients later confirmed as having TB to present with symptoms to the first health provider (patient delay) and the time taken between the first health care visit and initiation of tuberculosis treatment (health service delay). Factors relating to these 'delays' were analyzed. A cross-sectional survey, of 231 newly diagnosed smear-positive tuberculosis patients was conducted in Mulago National referral Hospital Kampala, from January to May 2002. Socio-demographic, lifestyle and health seeking factors were evaluated for their association with patient delay (> 2 weeks) and health service delay (> 4 weeks), using odds ratios with 95% confidence intervals (CI) including multivariate logistic regression. The median total delay to treatment initiation was 12 weeks. Patients often presented to drug shops or pharmacies (39.4%) and private clinics (36.8%) more commonly than government health units (14%) as initial contacts. Several independent predictors of 'patient delay' were identified: being hospitalized (odds ratio [0R] = 0.32; 95% CI: 0.12-0.80), daily alcohol consumption (OR = 3.7; CI: 1.57-9.76), subsistence farming (OR = 4.70; CI: 1.67-13.22), and perception of smoking as a cause of TB (OR = 5.54; CI: 2.26-13.58). Independent predictors of 'health service delay' were: > 2 health seeking encounters per month (OR = 2.74; CI: 1.10-6.83), and medical expenditure on TB related symptoms > 29 US dollars (OR = 3.88; CI: 1.19-12.62). Perceived TB stigma and education status was not associated with either form of delay. Delay in diagnosis of TB is prolonged at the referral centre with a significant proportion of Health service delay. More specific and effective health education of the general public on tuberculosis and seeking of appropriate medical consultation is likely to improve case detection. Certain specific groups require further attention. Alcoholics and subsistence farmers should be targeted to improve accessibility to TB treatment. Continuing medical education about TB management procedures for health providers and improvement in the capacity of TB control services should be undertaken.

Timeliness of lung cancer care in Victoria: a retrospective cohort study.

PubMed

Evans, Sue M; Earnest, Arul; Bower, Wendy; Senthuren, Meera; McLaughlin, Peta; Stirling, Rob

2016-02-01

To assess factors associated with second-line delays in the management of patients diagnosed with lung cancer. A retrospective cohort study, conducted in six public and two private Victorian hospitals, of 1417 patients aged 18 years or more who were diagnosed between July 2011 and October 2014 with an incident case of lung cancer identified by International Classification of Diseases, 10th revision codes (C34.0-C34.9, Z85.1, Z85.2) on the basis of either a clinical or pathological diagnosis. Time intervals between referral, diagnosis and initial definitive management. The median time from referral to diagnosis was 15 days (interquartile range [IQR], 5-36); from diagnosis to initial definitive management, 30 days (IQR, 6-84); and from referral to initial definitive management, 53 days (IQR, 25-106). Factors that were significantly associated with delay between referral and initial definitive management include declining or not being referred to palliative care (hazard ratio [HR], v patients referred for palliation, 0.73; 95% CI, 0.62-0.86; P < 0.001), and being treated in a public hospital (HR, v patients managed in a private hospital, 0.55; 95% CI, 0.48-0.64; P < 0.001). The median time from referral to initial definitive management in public and private hospitals was 61 days (IQR, 35-118) and 30 days (IQR, 13-76) respectively; 48% of patients in public hospitals waited longer than the British National Health Service target of a maximum 62 days between referral and first definitive treatment. There are significant delays at various stages of the patient journey after referral for initial definitive management. Having a greater understanding of these delays will enable strategies to be developed that improve the timeliness of care for patients with lung cancer.

Melatonin delays clutch initiation in a wild songbird

PubMed Central

Greives, Timothy J.; Kingma, Sjouke A.; Beltrami, Giulia; Hau, Michaela

2012-01-01

The hormone melatonin is known to play an important role in regulating many seasonal changes in physiology, morphology and behaviour. In birds, unlike in mammals, melatonin has thus far been thought to play little role in timing seasonal reproductive processes. This view is mainly derived from laboratory experiments on male birds. This study tests whether melatonin is capable of influencing the timing of clutch initiation in wild female songbirds. Free-living female great tits (Parus major) treated with melatonin-filled implants prior to the breeding season initiated their first clutch of the season significantly later than females carrying an empty implant. Melatonin treatment did not affect clutch size. Further, melatonin treatment did not delay the onset of daily activity in the wild nor adversely affect body mass in captivity compared with controls. These data suggest a previously unknown role for this hormone in regulating the timing of clutch initiation in the wild. PMID:22171024

Streamlining Workflow for Endovascular Mechanical Thrombectomy: Lessons Learned from a Comprehensive Stroke Center.

PubMed

Wang, Hongjin; Thevathasan, Arthur; Dowling, Richard; Bush, Steven; Mitchell, Peter; Yan, Bernard

2017-08-01

Recently, 5 randomized controlled trials confirmed the superiority of endovascular mechanical thrombectomy (EMT) to intravenous thrombolysis in acute ischemic stroke with large-vessel occlusion. The implication is that our health systems would witness an increasing number of patients treated with EMT. However, in-hospital delays, leading to increased time to reperfusion, are associated with poor clinical outcomes. This review outlines the in-hospital workflow of the treatment of acute ischemic stroke at a comprehensive stroke center and the lessons learned in reduction of in-hospital delays. The in-hospital workflow for acute ischemic stroke was described from prehospital notification to femoral arterial puncture in preparation for EMT. Systematic review of literature was also performed with PubMed. The implementation of workflow streamlining could result in reduction of in-hospital time delays for patients who were eligible for EMT. In particular, time-critical measures, including prehospital notification, the transfer of patients from door to computed tomography (CT) room, initiation of intravenous thrombolysis in the CT room, and the mobilization of neurointervention team in parallel with thrombolysis, all contributed to reduction in time delays. We have identified issues resulting in in-hospital time delays and have reported possible solutions to improve workflow efficiencies. We believe that these measures may help stroke centers initiate an EMT service for eligible patients. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Fixed-time synchronization of memristor-based BAM neural networks with time-varying discrete delay.

PubMed

Chen, Chuan; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2017-12-01

This paper is devoted to studying the fixed-time synchronization of memristor-based BAM neural networks (MBAMNNs) with discrete delay. Fixed-time synchronization means that synchronization can be achieved in a fixed time for any initial values of the considered systems. In the light of the double-layer structure of MBAMNNs, we design two similar feedback controllers. Based on Lyapunov stability theories, several criteria are established to guarantee that the drive and response MBAMNNs can realize synchronization in a fixed time. In particular, by changing the parameters of controllers, this fixed time can be adjusted to some desired value in advance, irrespective of the initial values of MBAMNNs. Numerical simulations are included to validate the derived results. Copyright © 2017 Elsevier Ltd. All rights reserved.

The use of a prospective audit proforma to improve door-to-mask times for acute exacerbations chronic obstructive pulmonary disease (COPD) requiring non-invasive ventilation (NIV).

PubMed

Mandal, S; Howes, T Q; Parker, M; Roberts, C M

2014-12-01

Non-invasive ventilation (NIV) is an evidence based management of acidotic, hypercapnic exacerbations of COPD. Previous national and international audits of clinical practice have shown variation against guideline standards with significant delays in initiating NIV. We aimed to map the clinical pathway to better understand delays and reduce the door-to-NIV time to less than 3 hours for all patients with acidotic, hypercapnic exacerbations of COPD requiring this intervention, by mandating the use of a guideline based educational management proforma.The proforma was introduced at 7 acute hospitals in North London and Essex and initiated at admission of the patient. It was used to record the clinical pathway and patient outcomes until the point of discharge or death. Data for 138 patients were collected. 48% of patients commenced NIV within 3 hours with no reduction in door-to-mask time during the study period. Delays in starting NIV were due to: time taken for review by the medical team (101 minutes) and time taken for NIV to be started once a decision had been made (49 minutes). There were significant differences in door-to-NIV decision and mask times between differing respiratory on-call systems, p < 0.05). The introduction of the proforma had no effect on door-to-mask times over the study period. Main reasons for delay were related to timely access to medical staff and to NIV equipment; however, a marked variation in practice within these hospitals was been noted, with a 9-5 respiratory on-call system associated with shorter NIV initiation times.

Associated factors for treatment delay in pulmonary tuberculosis in HIV-infected individuals: a nested case-control study.

PubMed

Coimbra, Isabella; Maruza, Magda; Militão-Albuquerque, Maria de Fátima Pessoa; Moura, Líbia Vilela; Diniz, George Tadeu Nunes; Miranda-Filho, Demócrito de Barros; Lacerda, Heloísa Ramos; Rodrigues, Laura Cunha; Ximenes, Ricardo Arraes de Alencar

2012-09-07

The delay in initiating treatment for tuberculosis (TB) in HIV-infected individuals may lead to the development of a more severe form of the disease, with higher rates of morbidity, mortality and transmissibility. The aim of the present study was to estimate the time interval between the onset of symptoms and initiating treatment for TB in HIV-infected individuals, and to identify the factors associated to this delay. A nested case-control study was undertaken within a cohort of HIV-infected individuals, attended at two HIV referral centers, in the state of Pernambuco, Brazil. Delay in initiating treatment for TB was defined as the period of time, in days, which was greater than the median value between the onset of cough and initiating treatment for TB. The study analyzed biological, clinical, socioeconomic, and lifestyle factors as well as those related to HIV and TB infection, potentially associated to delay. The odds ratios were estimated with the respective confidence intervals and p-values. From a cohort of 2365 HIV-infected adults, 274 presented pulmonary TB and of these, 242 participated in the study. Patients were already attending 2 health services at the time they developed a cough (period range: 1 - 552 days), with a median value of 41 days. Factors associated to delay were: systemic symptoms asthenia, chest pain, use of illicit drugs and sputum smear-negative. The present study indirectly showed the difficulty of diagnosing TB in HIV-infected individuals and indicated the need for a better assessment of asthenia and chest pain as factors that may be present in co-infected patients. It is also necessary to discuss the role played by negative sputum smear results in diagnosing TB/HIV co-infection as well as the need to assess the best approach for drug users with TB/HIV.

A necessary and sufficient condition for well-posedness of initial value problems of retarded functional differential equations

NASA Astrophysics Data System (ADS)

Nishiguchi, Junya

2017-09-01

We introduce the retarded functional differential equations (RFDEs) with general delay structure to treat various delay differential equations (DDEs) in a unified way and to clarify the delay structure in those dynamics. We are interested in the question as to which space of histories is suitable for the dynamics of each DDE, and investigate the well-posedness of the initial value problems (IVPs) of the RFDEs. A main theorem is that the IVP is well-posed for any ;admissible; history functional if and only if the semigroup determined by the trivial RFDE x ˙ = 0 is continuous. We clarify the meaning of the Hale-Kato axiom (Hale & Kato [12]) by applying this result to RFDEs with infinite delay. We also apply the result to DDEs with unbounded time- and state-dependent delays.

Timing and adequate attendance of antenatal care visits among women in Ethiopia.

PubMed

Yaya, Sanni; Bishwajit, Ghose; Ekholuenetale, Michael; Shah, Vaibhav; Kadio, Bernard; Udenigwe, Ogochukwu

2017-01-01

Although ANC services are increasingly available to women in low and middle-income countries, their inadequate use persists. This suggests a misalignment between aims of the services and maternal beliefs and circumstances. Owing to the dearth of studies examining the timing and adequacy of content of care, this current study aims to investigate the timing and frequency of ANC visits in Ethiopia. Data was obtained from the nationally representative 2011 Ethiopian Demographic and Health Survey (EDHS) which used a two-stage cluster sampling design to provide estimates for the health and demographic variables of interest for the country. Our study focused on a sample of 10,896 women with history of at least one childbirth event. Percentages of timing and adequacy of ANC visits were conducted across the levels of selected factors. Variables which were associated at 5% significance level were examined in the multivariable logistic regression model for association between timing and frequency of ANC visits and the explanatory variables while controlling for covariates. Furthermore, we presented the approach to estimate marginal effects involving covariate-adjusted logistic regression with corresponding 95%CI of delayed initiation of ANC visits and inadequate ANC attendance. The method used involved predicted probabilities added up to a weighted average showing the covariate distribution in the population. Results indicate that 66.3% of women did not use ANC at first trimester and 22.3% had ANC less than 4 visits. The results of this study were unique in that the association between delayed ANC visits and adequacy of ANC visits were examined using multivariable logistic model and the marginal effects using predicted probabilities. Results revealed that older age interval has higher odds of inadequate ANC visits. More so, type of place of residence was associated with delayed initiation of ANC visits, with rural women having the higher odds of delayed initiation of ANC visits (OR = 1.65; 95%CI: 1.26-2.18). However, rural women had 44% reduction in the odds of having inadequate ANC visits. In addition, multi-parity showed higher odds of delayed initiation of ANC visit when compared to the primigravida (OR = 2.20; 95%CI: 1.07-2.69). On the contrary, there was 36% reduction in the odds of multigravida having inadequate ANC visits when compared to the women who were primigravida. There were higher odds of inadequacy in ANC visits among women who engaged in sales/business, agriculture, skilled manual and other jobs when compared to women who currently do not work, after adjusting for covariates. From the predictive margins, assuming the distribution of all covariates remained the same among respondents, but everyone was aged 15-19 years, we would expect 71.8% delayed initiation of ANC visit. If everyone was aged 20-24years, 73.4%; 25-29years, 66.5%; 30-34years, 64.8%; 35-39years, 65.6%; 40-44years, 59.6% and 45-49years, we would expect 70.1% delayed initiation of ANC visit. If instead the distribution of age was as observed and for other covariates remained the same among respondents, but no respondent lived in the rural, we would expect about 61.4% delayed initiation of ANC visit; if however, everyone lived in the rural, and we would expect 71.6% delayed initiation in ANC visit. Model III revealed the predictive margins of all factors examined for delayed initiation for ANC visits, while Model IV presented the predictive marginal effects of the determinants of adequacy of ANC visits. The precise mechanism by which these factors affect ANC visits remain blurred at best. There may be factors on the demand side like the women's empowerment, financial support of the husband, knowledge of ANC visits in the context of timing, frequency and the expectations of ANC visits might be mediating the effects through the factors found associated in this study. Supply side factors like the quality of ANC services, skilled staff, and geographic location of the health centers also mediate their effects through the highlighted factors. Irrespective of the knowledge about the precise mechanism of action, policy makers could focus on improving women's empowerment, improving women's education, reducing wealth inequity and facilitating improved utilization of ANC through modifications on the supply side factors such as geographic location and focus on hard to reach women.

The risks and returns of stock investment in a financial market

NASA Astrophysics Data System (ADS)

Li, Jiang-Cheng; Mei, Dong-Cheng

2013-03-01

The risks and returns of stock investment are discussed via numerically simulating the mean escape time and the probability density function of stock price returns in the modified Heston model with time delay. Through analyzing the effects of delay time and initial position on the risks and returns of stock investment, the results indicate that: (i) There is an optimal delay time matching minimal risks of stock investment, maximal average stock price returns and strongest stability of stock price returns for strong elasticity of demand of stocks (EDS), but the opposite results for weak EDS; (ii) The increment of initial position recedes the risks of stock investment, strengthens the average stock price returns and enhances stability of stock price returns. Finally, the probability density function of stock price returns and the probability density function of volatility and the correlation function of stock price returns are compared with other literatures. In addition, good agreements are found between them.

Delay of Treatment Initiation Does Not Adversely Affect Survival Outcome in Breast Cancer.

PubMed

Yoo, Tae-Kyung; Han, Wonshik; Moon, Hyeong-Gon; Kim, Jisun; Lee, Jun Woo; Kim, Min Kyoon; Lee, Eunshin; Kim, Jongjin; Noh, Dong-Young

2016-07-01

Previous studies examining the relationship between time to treatment and survival outcome in breast cancer have shown inconsistent results. The aim of this study was to analyze the overall impact of delay of treatment initiation on patient survival and to determine whether certain subgroups require more prompt initiation of treatment. This study is a retrospective analysis of stage I-III patients who were treated in a single tertiary institution between 2005 and 2008. Kaplan-Meier survival analysis and Cox proportional hazards regression model were used to evaluate the impact of interval between diagnosis and treatment initiation in breast cancer and various subgroups. A total of 1,702 patients were included. Factors associated with longer delay of treatment initiation were diagnosis at another hospital, medical comorbidities, and procedures performed before admission for surgery. An interval between diagnosis and treatment initiation as a continuous variable or with a cutoff value of 15, 30, 45, and 60 days had no impact on disease-free survival (DFS). Subgroup analyses for hormone-responsiveness, triple-negative breast cancer, young age, clinical stage, and type of initial treatment showed no significant association between longer delay of treatment initiation and DFS. Our results show that an interval between diagnosis and treatment initiation of 60 days or shorter does not appear to adversely affect DFS in breast cancer.

Delayed Enhancement of Ascites After IV Contrast Material Administration at CT: Time Course and Clinical Correlation

PubMed Central

Benedetti, Nancy; Aslam, Rizwan; Wang, Zhen J.; Joe, Bonnie N.; Fu, Yanjun; Yee, Judy; Yeh, Benjamin M.

2010-01-01

OBJECTIVE The objective of our study was to determine the prevalence and clinical predictors of delayed contrast enhancement of ascites. MATERIALS AND METHODS In this retrospective study, 132 consecutive patients with ascites who underwent repeated abdominopelvic CT examinations performed within 7 days of each other were identified. These patients included 112 patients who received and 20 who did not receive IV contrast material at the initial CT examination. For each examination, we recorded the CT attenuation of the ascites. For the follow-up scan, the presence of delayed enhancement of ascites was defined as an increase in CT attenuation > 10 HU over baseline. The Fisher’s exact test, unpaired Student’s t test, and logistic regression were used to determine predictors of delayed enhancement of ascites. RESULTS A threshold increase in the attenuation of ascites by > 10 HU or more between the initial and follow-up CT examinations occurred only when IV contrast material was given with the initial examination. The increased attenuation was due to delayed contrast enhancement of ascites and occurred in 15 of the 112 patients (13%). Of the 16 patients scanned less than 1 day apart, 10 (63%) showed delayed enhancement of ascites. Delayed enhancement was not observed 3 or more days after IV contrast material administration. For each 1 mg/dL increase in serum creatinine level, the likelihood of delayed enhancement of ascites increased (odds ratio, 2.02; 95% CI, 1.11–3.69). Multivariate logistic regression showed that a short time interval between examinations (p < 0.001), increased serum creatinine level (p < 0.001), and presence of loculated ascites (p = < 0.01) were independent predictors of the magnitude of delayed enhancement of ascites. CONCLUSION Delayed contrast enhancement of ascites occurs commonly after recent prior IV contrast material administration and should not be mistaken for hemoperitoneum or proteinaceous fluid such as pus. PMID:19696286

Integrated Demand Management: Minimizing Unanticipated Excessive Departure Delay while Ensuring Fairness from a Traffic Management Initiative

NASA Technical Reports Server (NTRS)

Yoo, Hyo-Sang; Brasil, Connie; Buckley, Nathan; Mohlenbrink, Christoph; Speridakos, Constantine; Parke, Bonny; Hodell, Gita; Lee, Paul U.; Smith, Nancy M.

2017-01-01

This paper introduces NASA's Integrated Demand Management (IDM) concept and presents the results from an early proof-of-concept evaluation and an exploratory experiment. An initial development of the concept was focused on integrating two systems - i.e. the FAA's newly deployed Traffic Flow Management System (TFMS) tool called the Collaborative Trajectory Options Program (CTOP) and the Time-Based Flow Management (TBFM) system with Extended Metering (XM) capabilities to manage projected heavy traffic demand into a capacity-constrained airport. A human-in-the-loop (HITL) simulation experiment was conducted to demonstrate the feasibility of the initial development of the concept by adapting it to an arrival traffic problem at Newark Liberty International Airport (EWR) during clear weather conditions. In this study, the CTOP was utilized to strategically plan the arrival traffic demand by controlling take-off times of both short- and long-haul flights (long-hauls specify aircraft outside TBFM regions and short-hauls specify aircraft within TBFM regions) in a way that results in equitable delays among the groups. Such strategic planning allows less airborne delay to occur within TBFM by feeding manageable long-haul traffic demand while reserving sufficient slots in the overhead streams for the short-haul departures. The manageable traffic demand indicates the TBFM scheduler assigns no more airborne delay than its assigned airspace is capable of absorbing. TBFM then uses its time-based metering capabilities to deliver the desirable throughput by tactically rescheduling the TBFM entered long-haul flights and short-haul departures. Additional research was also performed to explore use of Required Time of Arrival (RTA) capabilities as a potential control mechanism for the airborne flights to improve arrival traffic delivery accuracy of scheduled long-haul traffic demand. The study results show that both short- and long-haul flights received similar ground delays. In addition, there was a noticeable reduction in the total amount of excessive unanticipated last-minute ground delays, i.e. delays that are frequently imposed on the short-haul flight in current day operations due to saturation in the overhead stream, commonly referred to as 'double penalty'. Furthermore, the concept achieved the target throughput while minimizing the expected cost associated with overall delays in arrival traffic. Assessment of the RTA capabilities showed that there was indeed improvement of the scheduled entry times into TBFM regions by using RTA capabilities. However, with respect to reduction in delays incurred within TBFM, there was no observable benefit of improving the precision of long-haul flights entry times.

Initiation of movement and energy expenditure in children with developmental delay: a case-control study.

PubMed

Chen, Chiao-Nan Joyce; Hwang, Ai-Wen; Lin, Shang-Ying; Lin, Yu-Chieh

2014-10-01

Lower levels of physical activity in children with developmental delay (DD) usually are attributed to higher energy costs. However, there is no evidence that children with DD spend more energy on daily physical activities, such as walking. The aim of this study was to compare energy costs during walking and movement initiation times in children with DD and children with typical development (TD) and matched for age. This was a case-control study. Children who were 3 and 5 years old and had DD (n=12) or TD (n=12) participated in the study. Measurements included ranges of motion in the lower extremities, physiological costs of walking, and movement initiation times. A task designed to evaluate the initiation of movement (the "go play with the toy" task) was used to examine the reaction times for children's goal-directed walking. The physiological costs of walking were similar in the 2 groups; however, children with DD walked at a lower speed than children with TD. Importantly, children with DD took more time to initiate goal-directed walking. The nature of the study design limited causal inference from the results. Children who were 3 to 5 years old and had DD had delays in goal-directed movement that may not have been attributable to motor impairments. The findings suggest that therapists should evaluate the movement initiation ability of 3- to 5-year-old children with DD as part of the design of an overall intervention plan. © 2014 American Physical Therapy Association.

Memory consolidation in aging and MCI after 1 week

PubMed Central

Walsh, Christine M; Wilkins, Sarah; Bettcher, Brianne Magouirk; Butler, Christopher R; Miller, Bruce L; Kramer, Joel H

2014-01-01

Objective To assess consolidation in amnestic mild cognitive (aMCI) impairment, controlling for differences in initial learning and using a protracted delay period for recall. Methods Fifteen individuals with MCI were compared to fifteen healthy older adult controls on a story learning task. Subjects were trained to criteria to equalize initial learning across subjects. Recall was tested at both the 30-minute typically used delay and a 1-week delay used to target consolidation. Results Using repeated measures ANOVAs adjusted for age, we found group × time point interactions across the entire task between the final trial and 30-minute delay, and again between the 30-minute and 1-week delay periods, with MCI having greater declines in recall as compared to controls. Significant group main effects were also found, with MCI recalling less than controls. Conclusion Consolidation was impaired in aMCI as compared to controls. Our findings indicate that MCI-related performance typically measured at 30 minutes underestimates MCI-associated memory deficits. This is the first study to isolate consolidation by controlling for initial learning differences and using a protracted delay period to target consolidation in an MCI sample. PMID:24219610

Expectancy of an open-book test decreases performance on a delayed closed-book test.

PubMed

Agarwal, Pooja K; Roediger, Henry L

2011-11-01

Two experiments examined the influence of practice with, and the expectancy of, open-book tests (students viewed studied material while taking the test) versus closed-book tests (students completed the test without viewing the studied material) on delayed retention and transfer. Using GRE materials specifically designed for open-book testing, participants studied passages and then took initial open- or closed-book tests. Open-book testing led to better initial performance than closed-book testing, but on a delayed criterial (closed-book) test both types of testing produced similar retention after a two-day delay in Experiment 1. In Experiment 2 participants were informed in advance about the type of delayed criterial test to expect (open- or closed-book). Expecting an open-book test (relative to a closed-book test) decreased participants' time spent studying and their delayed test performance on closed-book comprehension and transfer tests, demonstrating that test expectancy can influence long-term learning. Expectancy of open-book tests may impair long-term retention and transfer compared to closed-book tests, despite superior initial performance on open-book tests and students' preference for open-book tests.

Initial Misdiagnosis of Proximal Pancreatic Adenocarcinoma Is Associated with Delay in Diagnosis and Advanced Stage at Presentation.

PubMed

Swords, Douglas S; Mone, Mary C; Zhang, Chong; Presson, Angela P; Mulvihill, Sean J; Scaife, Courtney L

2015-10-01

Delay in diagnosis of pancreatic ductal adenocarcinoma (PDAC) is associated with decreased survival. The effect of an initial misdiagnosis on delay in diagnosis and stage of PDAC is unknown. This study is a retrospective review (2000-2010) from a University-based cancer center of new diagnoses of proximal PDAC. Of 313 patients, 98 (31.3 %) had an initial misdiagnosis. Misdiagnosed patients were younger, 62.8 ± 12.6 vs. 68.0 ± 10.1 (p < 0.001). The most common initial misdiagnoses were: gallbladder disease, gastroesophageal reflux disease, and peptic ulcer disease. After excluding patients with prior cholecystectomy, 14.2 % were misdiagnosed with gallbladder disease and underwent cholecystectomy before PDAC diagnosis. Misdiagnosed patients had higher rates of abdominal pain (p < 0.001), weight loss (p = 0.04), and acute pancreatitis (p < 0.001) and lower rate of jaundice (p < 0.001). Median time between symptoms to PDAC diagnosis was longer in misdiagnosed: 4.2 months vs. 1.4 (p < 0.001). Median time from contact with medical provider to axial imaging was longer in misdiagnosed (p < 0.001). Rate of stages III-IV disease at diagnosis was higher in misdiagnosed: 61.2 vs. 43.7 % (p = 0.004), with a 1.4 (95 % confidence interval (CI), 1.12-1.74) higher risk of stages III-IV disease at diagnosis; however, there was no difference in median overall survival in misdiagnosed patients (9.6 months in misdiagnosed vs. 10.3 months in correctly diagnosed, p = 0.69). Initial misdiagnosis of patients with proximal PDAC is associated with delay in diagnosis and higher risk of locally advanced or advanced disease at time of PDAC diagnosis.

Lens Model and Time Delay Predictions for the Sextuply Lensed Quasar SDSS J2222+2745*

NASA Technical Reports Server (NTRS)

Sharon, Keren; Bayliss, Matthew B.; Dahle, Hakon; Florian, Michael K.; Gladders, Michael D.; Johnson, Traci L.; Paterno-Mahler, Rachel; Rigby, Jane R.; Whitaker, Katherine E.; Wuyts, Eva

2017-01-01

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image of the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found T(sub AB) = 47.7 +/- 6.0 days and T(sub AC) = 722 +/- 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are T(sub AD) = 502+/- 68 days, T( sub AE) = 611 +/- 75 days, and T(sub AF) = 415 +/- 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift, indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion.

LENS MODEL AND TIME DELAY PREDICTIONS FOR THE SEXTUPLY LENSED QUASAR SDSS J2222+2745

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharon, Keren; Johnson, Traci L.; Paterno-Mahler, Rachel

2017-01-20

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image ofmore » the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found τ {sub AB} = 47.7 ± 6.0 days and τ {sub AC} = −722 ± 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are τ {sub AD} = 502 ± 68 days, τ {sub AE} = 611 ± 75 days, and τ {sub AF} = 415 ± 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift , indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion.« less

Determinants of choice for pigeons and humans on concurrent-chains schedules of reinforcement.

PubMed

Belke, T W; Pierce, W D; Powell, R A

1989-09-01

Concurrent-chains schedules of reinforcement were arranged for humans and pigeons. Responses of humans were reinforced with tokens exchangeable for money, and key pecks of 4 birds were reinforced with food. Variable-interval 30-s and 40-s schedules operated in the terminal links of the chains. Condition 1 exposed subjects to variable-interval 90-s and variable-interval 30-s initial links, respectively. Conditions 2 and 3 arranged equal initial-link schedules of 40 s or 120 s. Experimental conditions tested the descriptive adequacy of five equations: reinforcement density, delay reduction, modified delay reduction, matching and maximization. Results based on choice proportions and switch rates during the initial links showed that pigeons behaved in accord with delay-reduction models, whereas humans maximized overall rate of reinforcement. As discussed by Logue and associates in self-control research, different types of reinforcement may affect sensitivity to delay differentially. Pigeons' responses were reinforced with food, a reinforcer that is consumable upon presentation. Humans' responses were reinforced with money, a reinforcer exchanged for consumable reinforcers after it was earned. Reinforcers that are immediately consumed may generate high sensitivity to delay and behavior described as delay reduction. Reinforces with longer times to consumption may generate low sensitivity to delay and behavior that maximizes overall payoff.

Delays before Diagnosis and Initiation of Treatment in Patients Presenting to Mental Health Services with Bipolar Disorder

PubMed Central

Patel, Rashmi; Shetty, Hitesh; Jackson, Richard; Broadbent, Matthew; Stewart, Robert; Boydell, Jane; McGuire, Philip; Taylor, Matthew

2015-01-01

Background Bipolar disorder is a significant cause of morbidity and mortality. Although existing treatments are effective, there is often a substantial delay before diagnosis and treatment initiation. We sought to investigate factors associated with the delay before diagnosis of bipolar disorder and the onset of treatment in secondary mental healthcare. Method Retrospective cohort study using anonymised electronic mental health record data from the South London and Maudsley NHS Foundation Trust (SLaM) Biomedical Research Centre (BRC) Case Register on 1364 adults diagnosed with bipolar disorder between 2007 and 2012. The following predictor variables were analysed in a multivariable Cox regression analysis: age, gender, ethnicity, compulsory admission to hospital under the UK Mental Health Act, marital status and other diagnoses prior to bipolar disorder. The outcomes were time to recorded diagnosis from first presentation to specialist mental health services (the diagnostic delay), and time to the start of appropriate therapy (treatment delay). Results The median diagnostic delay was 62 days (interquartile range: 17–243) and median treatment delay was 31 days (4–122). Compulsory hospital admission was associated with a significant reduction in both diagnostic delay (hazard ratio 2.58, 95% CI 2.18–3.06) and treatment delay (4.40, 3.63–5.62). Prior diagnoses of other psychiatric disorders were associated with increased diagnostic delay, particularly alcohol (0.48, 0.33–0.41) and substance misuse disorders (0.44, 0.31–0.61). Prior diagnosis of schizophrenia and psychotic depression were associated with reduced treatment delay. Conclusions Some individuals experience a significant delay in diagnosis and treatment of bipolar disorder after initiation of specialist mental healthcare, particularly those who have prior diagnoses of alcohol and substance misuse disorders. These findings highlight a need for further study on strategies to better identify underlying symptoms and offer appropriate treatment sooner in order to facilitate improved clinical outcomes, such as developing specialist early intervention services to identify and treat people with bipolar disorder. PMID:25992560

An efficient hybrid method for stochastic reaction-diffusion biochemical systems with delay

NASA Astrophysics Data System (ADS)

Sayyidmousavi, Alireza; Ilie, Silvana

2017-12-01

Many chemical reactions, such as gene transcription and translation in living cells, need a certain time to finish once they are initiated. Simulating stochastic models of reaction-diffusion systems with delay can be computationally expensive. In the present paper, a novel hybrid algorithm is proposed to accelerate the stochastic simulation of delayed reaction-diffusion systems. The delayed reactions may be of consuming or non-consuming delay type. The algorithm is designed for moderately stiff systems in which the events can be partitioned into slow and fast subsets according to their propensities. The proposed algorithm is applied to three benchmark problems and the results are compared with those of the delayed Inhomogeneous Stochastic Simulation Algorithm. The numerical results show that the new hybrid algorithm achieves considerable speed-up in the run time and very good accuracy.

Supervising Remote Humanoids Across Intermediate Time Delay

NASA Technical Reports Server (NTRS)

Hambuchen, Kimberly; Bluethmann, William; Goza, Michael; Ambrose, Robert; Rabe, Kenneth; Allan, Mark

2006-01-01

The President's Vision for Space Exploration, laid out in 2004, relies heavily upon robotic exploration of the lunar surface in early phases of the program. Prior to the arrival of astronauts on the lunar surface, these robots will be required to be controlled across space and time, posing a considerable challenge for traditional telepresence techniques. Because time delays will be measured in seconds, not minutes as is the case for Mars Exploration, uploading the plan for a day seems excessive. An approach for controlling humanoids under intermediate time delay is presented. This approach uses software running within a ground control cockpit to predict an immersed robot supervisor's motions which the remote humanoid autonomously executes. Initial results are presented.

Real Time Metrics and Analysis of Integrated Arrival, Departure, and Surface Operations

NASA Technical Reports Server (NTRS)

Sharma, Shivanjli; Fergus, John

2017-01-01

A real time dashboard was developed in order to inform and present users notifications and integrated information regarding airport surface operations. The dashboard is a supplement to capabilities and tools that incorporate arrival, departure, and surface air-traffic operations concepts in a NextGen environment. As trajectory-based departure scheduling and collaborative decision making tools are introduced in order to reduce delays and uncertainties in taxi and climb operations across the National Airspace System, users across a number of roles benefit from a real time system that enables common situational awareness. In addition to shared situational awareness the dashboard offers the ability to compute real time metrics and analysis to inform users about capacity, predictability, and efficiency of the system as a whole. This paper describes the architecture of the real time dashboard as well as an initial set of metrics computed on operational data. The potential impact of the real time dashboard is studied at the site identified for initial deployment and demonstration in 2017; Charlotte-Douglas International Airport. Analysis and metrics computed in real time illustrate the opportunity to provide common situational awareness and inform users of metrics across delay, throughput, taxi time, and airport capacity. In addition, common awareness of delays and the impact of takeoff and departure restrictions stemming from traffic flow management initiatives are explored. The potential of the real time tool to inform the predictability and efficiency of using a trajectory-based departure scheduling system is also discussed.

Finite-time and fixed-time synchronization analysis of inertial memristive neural networks with time-varying delays.

PubMed

Wei, Ruoyu; Cao, Jinde; Alsaedi, Ahmed

2018-02-01

This paper investigates the finite-time synchronization and fixed-time synchronization problems of inertial memristive neural networks with time-varying delays. By utilizing the Filippov discontinuous theory and Lyapunov stability theory, several sufficient conditions are derived to ensure finite-time synchronization of inertial memristive neural networks. Then, for the purpose of making the setting time independent of initial condition, we consider the fixed-time synchronization. A novel criterion guaranteeing the fixed-time synchronization of inertial memristive neural networks is derived. Finally, three examples are provided to demonstrate the effectiveness of our main results.

Initiation of nutritional support is delayed in critically ill obese patients: a multicenter cohort study.

PubMed

Borel, Anne-Laure; Schwebel, Carole; Planquette, Benjamin; Vésin, Aurélien; Garrouste-Orgeas, Maité; Adrie, Christophe; Clec'h, Christophe; Azoulay, Elie; Souweine, Bertrand; Allaouchiche, Bernard; Goldgran-Toledano, Dany; Jamali, Samir; Darmon, Michael; Timsit, Jean-François

2014-09-01

A high catabolic rate characterizes the acute phase of critical illness. Guidelines recommend an early nutritional support, regardless of the previous nutritional status. We aimed to assess whether the nutritional status of patients, which was defined by the body mass index (BMI) at admission in an intensive care unit (ICU), affected the time of nutritional support initiation. We conducted a cohort study that reported a retrospective analysis of a multicenter ICU database (OUTCOMEREA) by using data prospectively entered from January 1997 to October 2012. Patients who needed orotracheal intubation within the first 72 h and >3 d were included. Data from 3257 ICU stays were analyzed. The delay before feeding was different according to BMI groups (P = 0.035). The delay was longer in obese patients [BMI (in kg/m²) ≥30; n = 663] than in other patients with either low weight (BMI <20; n = 501), normal weight (BMI ≥20 and <25; n = 1135), or overweight (BMI ≥25 and <30; n = 958). The association between nutritional status and a delay in nutrition initiation was independent of potential confounding factors such as age, sex, and diabetes or other chronic diseases. In comparison with normal weight, the adjusted RR (95% CI) associated with a delayed nutrition initiation was 0.92 (0.86, 0.98) for patients with low weight, 1.00 (0.94, 1.05) for overweight patients, and 1.06 (1.00, 1.12) for obese patients (P = 0.004). The initiation of nutritional support was delayed in obese ICU patients. Randomized controlled trials that address consequences of early compared with delayed beginnings of nutritional support in critically ill obese patients are needed. © 2014 American Society for Nutrition.

Chromosome damage evolution after low and high LET irradiation

NASA Astrophysics Data System (ADS)

Andreev, Sergey; Eidelman, Yuri

Ionizing radiation induces DNA and chromatin lesions which are converted to chromosome lesions detected in the first post-irradiation mitosis by classic cytogenetic techniques as chromosomal aberrations (CAs). These techniques allow to monitor also delayed aberrations observed after many cell generations post-irradiation - the manifestation of chromosomal instability phenotype (CIN). The problem discussed is how to predict time evolution from initial to delayed DNA/chromosome damage. To address this question, in the present work a mechanistic model of CIN is elaborated which integrates pathways of (*) DNA damage induction and its conversion to chromosome lesions (aberrations), (**) lesion transmission and generation through cell cycles. Delayed aberrations in subsequent cycles are formed in the model owing to two pathways, DNA damage generation de novo as well as CA transmission from previous cycles. DNA damage generation rate is assumed to consist of bystander and non-bystander components. Bystander signals impact all cells roughly equally, whereas non-bystander DSB generation rate differs for the descendants of unirradiated and irradiated cells. Monte Carlo simulation of processes underlying CIN allows to predict the time evolution of initial radiation-induced damage - kinetics curve for delayed unstable aberrations (dicentrics) together with dose response and RBE as a function of time after high vs low LET irradiation. The experimental data for radiation-induced CIN in TK6 lymphoblastoid cells and human lymphocytes irradiated with low (gamma) and high (Fe, C) LET radiation are analyzed on the basis of the proposed model. One of the conclusions is that without bystander signaling, just taking into account the initial DNA damage and non-bystander DSB generation, it is impossible to describe the available experimental data for high-LET-induced CIN. The exact contribution of bystander effects for high vs low LET remains unknown, but the relative contribution may be assessed at large times after initial acute irradiation. RBE for delayed aberrations depends on LET, time and cell line, which probably reflects a genetic background for bystander component. The proposed modeling approach creates a basis for integration of complex network of bystander/inflammatory signaling in systems-level platform for quantification of radiation induced CIN.

Feasibility of Routinely Offering Early Combined Antiretroviral Therapy to HIV-infected Infants in a Resource-limited Country: The ANRS-PediaCAM Study in Cameroon.

PubMed

Tejiokem, Mathurin Cyrille; Warszawski, Josiane; Ateba Ndongo, Francis; Tetang Ndiang, Suzie; Ndongo, Jean Audrey; Owona, Félicité; Ngoupo, Paul Alain; Tchendjou, Patrice; Kfutwah, Anfumbom; Penda, Ida Calixte; Faye, Albert

2015-10-01

Early diagnosis of HIV is increasingly available for infants in resource-limited settings. We assessed the timing of events until combined antiretroviral therapy (cART) initiation in infants diagnosed before 7 months of age in Cameroon. The ANRS-PediaCAM cohort included HIV-infected infants followed from birth associated with prevention of mother-to-child transmission activities (group 1) or diagnosed for any other reason before 7 months of age (group 2). All infants were offered free cART early after diagnosis. Frequency and factors associated with no or delayed cART initiation, were studied using univariable and multivariable logistic regressions. Between 2007 and 2011, 210 HIV-infected infants (group 1: 69; group 2: 141) were included. Fewer group 1 (14.3%) than group 2 (59.1%) infants were symptomatic (World Health Organization stage 3 or 4). Overall, 5.7% (n = 12) died before receiving any cART. Of the remaining 198 infants, 3.0% (n = 6) were not treated. The median age at initiating cART was 4.1 months [interquartile range (IQR): 3.2-5.6]. The median time until cART initiation after HIV testing was 6.2 weeks (IQR: 4.4-9.4) in group 1 and 5.1 weeks (IQR: 2.9-9.4) in group 2. No or delayed cART, observed for 37.9% (75 of 198) of the infants, was associated with clinical site [adjusted odds ratio (aOR): 4.8; 95% confidence interval: (2.1-11.2)], late diagnosis [aOR: 2.0 (0.9-4.1)], and delayed pretherapeutic biological assessment [aOR: 3.7 (1.4-10.0)]. Although most children included were treated before age 7 months, the initiation of therapy was delayed for more than 1 in 3. The period around HIV diagnosis is critical and should be better managed to reduce delays before cART initiation.

The dark side of testing memory: repeated retrieval can enhance eyewitness suggestibility.

PubMed

Chan, Jason C K; Lapaglia, Jessica A

2011-12-01

Eyewitnesses typically recount their experiences many times before trial. Such repeated retrieval can enhance memory retention of the witnessed event. However, recent studies (e.g., Chan, Thomas, & Bulevich, 2009) have found that initial retrieval can exacerbate eyewitness suggestibility to later misleading information--a finding termed retrieval-enhanced suggestibility (RES). Here we examined the influence of multiple retrieval attempts on eyewitness suggestibility to subsequent misinformation. In four experiments, we systematically varied the number of initial tests taken (between zero and six), the delay between initial testing and misinformation exposure (~30 min or 1 week), and whether initial testing was manipulated between- or within-subjects. University undergraduate students were used as participants. Overall, we found that eyewitness suggestibility increased as the number of initial tests increased, but this RES effect was qualified by the delay and by whether initial testing occurred in a within- or between-subjects manner. Specifically, the within-subjects RES effect was smaller than the between-subjects RES effect, possibly because of the influence of retrieval-induced forgetting/facilitation (Chan, 2009) when initial testing was manipulated within subjects. Moreover, consistent with the testing effect literature (Roediger & Karpicke, 2006), the benefits of repeated testing on later memory were stronger after a 1-week delay than after a 30-min delay, thus reducing the negative impact of RES in long-term situations. These findings suggest that conditions that are likely to occur in criminal investigations can either increase (repeated testing) or reduce (delay) the influence of RES, thus further demonstrating the complex relationship between eyewitness memory and repeated retrieval.

Coherent Pattern Prediction in Swarms of Delay-Coupled Agents

NASA Astrophysics Data System (ADS)

Mier-Y-Teran-Romero, Luis; Forgoston, Eric; Scwartz, Ira

2013-03-01

We consider a general swarm model of self-propelling particles interacting through a pairwise potential in the presence of a fixed communication time delay. Previous work has shown that swarms with communication time delays and noise may display pattern transitions that depend on the size of the coupling amplitude. We extend these results by completely unfolding the bifurcation structure of the mean field approximation. Our analysis reveals a direct correspondence between the different dynamical behaviors found in different regions of the coupling-time delay plane with the different classes of simulated coherent swarm patterns. We derive the spatio-temporal scales of the swarm structures, and also demonstrate how the complicated interplay of coupling strength, time delay, noise intensity, and choice of initial conditions can affect the swarm. In addition, when adding noise to the system, we find that for sufficiently large values of the coupling strength and/or the time delay, there is a noise intensity threshold that forces a transition of the swarm from a misaligned state into an aligned state. We show that this alignment transition exhibits hysteresis when the noise intensity is taken to be time dependent. Office of Naval Research, NIH (LMR and IBS) and NRL (EF)

A comprehensive review of prehospital and in-hospital delay times in acute stroke care.

PubMed

Evenson, K R; Foraker, R E; Morris, D L; Rosamond, W D

2009-06-01

The purpose of this study was to systematically review and summarize prehospital and in-hospital stroke evaluation and treatment delay times. We identified 123 unique peer-reviewed studies published from 1981 to 2007 of prehospital and in-hospital delay time for evaluation and treatment of patients with stroke, transient ischemic attack, or stroke-like symptoms. Based on studies of 65 different population groups, the weighted Poisson regression indicated a 6.0% annual decline (P<0.001) in hours/year for prehospital delay, defined from symptom onset to emergency department arrival. For in-hospital delay, the weighted Poisson regression models indicated no meaningful changes in delay time from emergency department arrival to emergency department evaluation (3.1%, P=0.49 based on 12 population groups). There was a 10.2% annual decline in hours/year from emergency department arrival to neurology evaluation or notification (P=0.23 based on 16 population groups) and a 10.7% annual decline in hours/year for delay time from emergency department arrival to initiation of computed tomography (P=0.11 based on 23 population groups). Only one study reported on times from arrival to computed tomography scan interpretation, two studies on arrival to drug administration, and no studies on arrival to transfer to an in-patient setting, precluding generalizations. Prehospital delay continues to contribute the largest proportion of delay time. The next decade provides opportunities to establish more effective community-based interventions worldwide. It will be crucial to have effective stroke surveillance systems in place to better understand and improve both prehospital and in-hospital delays for acute stroke care.

Catalyst–substrate interaction and growth delay in vapor–liquid–solid nanowire growth

NASA Astrophysics Data System (ADS)

Kolíbal, Miroslav; Pejchal, Tomáš; Musálek, Tomáš; Šikola, Tomáš

2018-05-01

Understanding of the initial stage of nanowire growth on a bulk substrate is crucial for the rational design of nanowire building blocks in future electronic and optoelectronic devices. Here, we provide in situ scanning electron microscopy and Auger microscopy analysis of the initial stage of Au-catalyzed Ge nanowire growth on different substrates. Real-time microscopy imaging and elementally resolved spectroscopy clearly show that the catalyst dissolves the underlying substrate if held above a certain temperature. If the substrate dissolution is blocked (or in the case of heteroepitaxy) the catalyst needs to be filled with nanowire material from the external supply, which significantly increases the initial growth delay. The experiments presented here reveal the important role of the substrate in metal-catalyzed nanowire growth and pave the way for different growth delay mitigation strategies.

Catalyst-substrate interaction and growth delay in vapor-liquid-solid nanowire growth.

PubMed

Kolíbal, Miroslav; Pejchal, Tomáš; Musálek, Tomáš; Šikola, Tomáš

2018-05-18

Understanding of the initial stage of nanowire growth on a bulk substrate is crucial for the rational design of nanowire building blocks in future electronic and optoelectronic devices. Here, we provide in situ scanning electron microscopy and Auger microscopy analysis of the initial stage of Au-catalyzed Ge nanowire growth on different substrates. Real-time microscopy imaging and elementally resolved spectroscopy clearly show that the catalyst dissolves the underlying substrate if held above a certain temperature. If the substrate dissolution is blocked (or in the case of heteroepitaxy) the catalyst needs to be filled with nanowire material from the external supply, which significantly increases the initial growth delay. The experiments presented here reveal the important role of the substrate in metal-catalyzed nanowire growth and pave the way for different growth delay mitigation strategies.

Circulating carotenoid concentrations are positively correlated with later clutch initiation in Florida Scrub-Jays (Aphelocoma coerulescens).

PubMed

Heiss, Rebecca S; Cohen, Alan A; Bowman, Reed; Boughton, Raoul K; Bridge, Eli; McGraw, Kevin J; Schoech, Stephan J

2011-02-01

Antioxidants play key roles in preventing free radical damage to various molecules, cells, and tissues, but it is not well understood how variation in antioxidant levels may relate to the reproductive success or health of wild animals. We explored the relationship between circulating antioxidant concentrations and both body condition and timing of reproduction in male and female Florida Scrub-Jays (Aphelocoma coerulescens), a cooperatively breeding passerine bird. We examined whether levels of uric acid, vitamin E, and carotenoids (all potentially important antioxidants) were linked to body condition and timing of reproduction, two measures that are directly related to reproductive success. Antioxidant concentrations were not correlated with body condition, but they were related to timing of first clutch initiation, though not always in the predicted direction. Elevated circulating levels of carotenoids were associated with delayed clutch initiation in female breeders. Relatively higher vitamin E levels in control birds were associated with earlier clutch initiation, whereas male breeders that received long-term food supplementation had elevated levels of vitamin E and delayed reproduction. Several potential explanations for the link between elevated levels of antioxidants and delayed clutch initiation are discussed. Separate explanations for each sex include, but are not limited to, oxidative stress as a result of territory defense efforts in males, different dietary regimes due to supplementation, and mobilized plasma antioxidants in females that were coping with a stressor. © 2010 Wiley-Liss, Inc.

Methane oxidation behind reflected shock waves: Ignition delay times measured by pressure and flame band emission

NASA Technical Reports Server (NTRS)

Brabbs, T. A.; Robertson, T. F.

1986-01-01

Ignition delay data were recorded for three methane-oxygen-argon mixtures (phi = 0.5, 1.0, 2.0) for the temperature range 1500 to 1920 K. Quiet pressure trances enabled us to obtain delay times for the start of the experimental pressure rise. These times were in good agreement with those obtained from the flame band emission at 3700 A. The data correlated well with the oxygen and methane dependence of Lifshitz, but showed a much stronger temperature dependence (phi = 0.5 delta E = 51.9, phi = 1.0 delta = 58.8, phi = 2.0 delta E = 58.7 Kcal). The effect of probe location on the delay time measurement was studied. It appears that the probe located 83 mm from the reflecting surface measured delay times which may not be related to the initial temperature and pressure. It was estimated that for a probe located 7 mm from the reflecting surface, the measured delay time would be about 10 microseconds too short, and it was suggested that delay times less than 100 microsecond should not be used. The ignition period was defined as the time interval between start of the experimental pressure rise and 50 percent of the ignition pressure. This time interval was measured for three gas mixtures and found to be similar (40 to 60 micro sec) for phi = 1.0 and 0.5 but much longer (100 to 120) microsecond for phi = 2.0. It was suggested that the ignition period would be very useful to the kinetic modeler in judging the agreement between experimental and calculated delay times.

Time from symptoms to definitive diagnosis of idiopathic pulmonary arterial hypertension: The delay study

PubMed Central

Strange, Geoff; Gabbay, Eli; Kermeen, Fiona; Williams, Trevor; Carrington, Melinda; Stewart, Simon; Keogh, Anne

2013-01-01

Survival rates for patients with idiopathic pulmonary arterial hypertension (IPAH) have improved with the introduction of PAH-specific therapies. However, the time between patient-reported onset of symptoms and a definitive diagnosis of IPAH is consistently delayed. We conducted a retrospective, multi-center, descriptive investigation in order to (a) understand what factors contribute to persistent diagnostic delays, and (b) examine the time from initial symptom onset to a definitive diagnosis of IPAH. Between January 2007 and December 2008, we enrolled consecutively diagnosed adults with IPAH from four tertiary referral centers in Australia. Screening of patient records and “one-on-one” interviews were used to determine the time from patient-described initial symptoms to a diagnosis of IPAH, confirmed by right heart catheterization (RHC). Thirty-two participants (69% female) were studied. Mean age at symptom onset was 56 ± 16.4 years and 96% reported exertional dyspnea. Mean time from symptom onset to diagnosis was 47 ± 34 months with patients subsequently aged 60 ± 17.3 years. Patients reported 5.3 ± 3.8 GP visits and 3.0 ± 2.1 specialist reviews before being seen at a pulmonary hypertension (PH) center. Advanced age, number of general practitioner (GP) visits, heart rate, and systolic blood pressure at the time of diagnosis were significantly associated with the observed delay. We found a significant delay of 3.9 years from symptom onset to a diagnosis of IPAH in Australia. Exertional dyspnea is the most common presenting symptom. Current practice within Australia does not appear to have the specific capacity for timely, multi-factorial evaluation of breathlessness and potential IPAH. PMID:23662179

Modified M505A3 Fuze with Delay Function

DTIC Science & Technology

1974-10-01

forward initiation on the firing pin entrance hole to the rotor cavity. The triple staked detonator also functioned on the 0.063-inch target at 75... effectiveness of this projectile against aircraft targets by Incorporating a time delay which enables the projectile to penetrate the aircraft skin...prior to detonation. This effort required the design of modifications to the M505A3 fuze to achieve a delay function without modifying the rotor

Analyzing Double Delays at Newark Liberty International Airport

NASA Technical Reports Server (NTRS)

Evans, Antony D.; Lee, Paul

2016-01-01

When weather or congestion impacts the National Airspace System, multiple different Traffic Management Initiatives can be implemented, sometimes with unintended consequences. One particular inefficiency that is commonly identified is in the interaction between Ground Delay Programs (GDPs) and time based metering of internal departures, or TMA scheduling. Internal departures under TMA scheduling can take large GDP delays, followed by large TMA scheduling delays, because they cannot be easily fitted into the overhead stream. In this paper we examine the causes of these double delays through an analysis of arrival operations at Newark Liberty International Airport (EWR) from June to August 2010. Depending on how the double delay is defined between 0.3 percent and 0.8 percent of arrivals at EWR experienced double delays in this period. However, this represents between 21 percent and 62 percent of all internal departures in GDP and TMA scheduling. A deep dive into the data reveals that two causes of high internal departure scheduling delays are upstream flights making up time between their estimated departure clearance times (EDCTs) and entry into time based metering, which undermines the sequencing and spacing underlying the flight EDCTs, and high demand on TMA, when TMA airborne metering delays are high. Data mining methods (currently) including logistic regression, support vector machines and K-nearest neighbors are used to predict the occurrence of double delays and high internal departure scheduling delays with accuracies up to 0.68. So far, key indicators of double delay and high internal departure scheduling delay are TMA virtual runway queue size, and the degree to which estimated runway demand based on TMA estimated times of arrival has changed relative to the estimated runway demand based on EDCTs. However, more analysis is needed to confirm this.

Towards Supervising Remote Dexterous Robots Across Time Delay

NASA Technical Reports Server (NTRS)

Hambuchen, Kimberly; Bluethmann, William; Goza, Michael; Ambrose, Robert; Wheeler, Kevin; Rabe, Ken

2006-01-01

The President s Vision for Space Exploration, laid out in 2004, relies heavily upon robotic exploration of the lunar surface in early phases of the program. Prior to the arrival of astronauts on the lunar surface, these robots will be required to be controlled across space and time, posing a considerable challenge for traditional telepresence techniques. Because time delays will be measured in seconds, not minutes as is the case for Mars Exploration, uploading the plan for a day seems excessive. An approach for controlling dexterous robots under intermediate time delay is presented, in which software running within a ground control cockpit predicts the intention of an immersed robot supervisor, then the remote robot autonomously executes the supervisor s intended tasks. Initial results are presented.

Timing and adequate attendance of antenatal care visits among women in Ethiopia

PubMed Central

Bishwajit, Ghose; Ekholuenetale, Michael; Shah, Vaibhav; Kadio, Bernard; Udenigwe, Ogochukwu

2017-01-01

Introduction Although ANC services are increasingly available to women in low and middle-income countries, their inadequate use persists. This suggests a misalignment between aims of the services and maternal beliefs and circumstances. Owing to the dearth of studies examining the timing and adequacy of content of care, this current study aims to investigate the timing and frequency of ANC visits in Ethiopia. Methods Data was obtained from the nationally representative 2011 Ethiopian Demographic and Health Survey (EDHS) which used a two-stage cluster sampling design to provide estimates for the health and demographic variables of interest for the country. Our study focused on a sample of 10,896 women with history of at least one childbirth event. Percentages of timing and adequacy of ANC visits were conducted across the levels of selected factors. Variables which were associated at 5% significance level were examined in the multivariable logistic regression model for association between timing and frequency of ANC visits and the explanatory variables while controlling for covariates. Furthermore, we presented the approach to estimate marginal effects involving covariate-adjusted logistic regression with corresponding 95%CI of delayed initiation of ANC visits and inadequate ANC attendance. The method used involved predicted probabilities added up to a weighted average showing the covariate distribution in the population. Results Results indicate that 66.3% of women did not use ANC at first trimester and 22.3% had ANC less than 4 visits. The results of this study were unique in that the association between delayed ANC visits and adequacy of ANC visits were examined using multivariable logistic model and the marginal effects using predicted probabilities. Results revealed that older age interval has higher odds of inadequate ANC visits. More so, type of place of residence was associated with delayed initiation of ANC visits, with rural women having the higher odds of delayed initiation of ANC visits (OR = 1.65; 95%CI: 1.26–2.18). However, rural women had 44% reduction in the odds of having inadequate ANC visits. In addition, multi-parity showed higher odds of delayed initiation of ANC visit when compared to the primigravida (OR = 2.20; 95%CI: 1.07–2.69). On the contrary, there was 36% reduction in the odds of multigravida having inadequate ANC visits when compared to the women who were primigravida. There were higher odds of inadequacy in ANC visits among women who engaged in sales/business, agriculture, skilled manual and other jobs when compared to women who currently do not work, after adjusting for covariates. From the predictive margins, assuming the distribution of all covariates remained the same among respondents, but everyone was aged 15–19 years, we would expect 71.8% delayed initiation of ANC visit. If everyone was aged 20-24years, 73.4%; 25-29years, 66.5%; 30-34years, 64.8%; 35-39years, 65.6%; 40-44years, 59.6% and 45-49years, we would expect 70.1% delayed initiation of ANC visit. If instead the distribution of age was as observed and for other covariates remained the same among respondents, but no respondent lived in the rural, we would expect about 61.4% delayed initiation of ANC visit; if however, everyone lived in the rural, and we would expect 71.6% delayed initiation in ANC visit. Model III revealed the predictive margins of all factors examined for delayed initiation for ANC visits, while Model IV presented the predictive marginal effects of the determinants of adequacy of ANC visits. Conclusion The precise mechanism by which these factors affect ANC visits remain blurred at best. There may be factors on the demand side like the women’s empowerment, financial support of the husband, knowledge of ANC visits in the context of timing, frequency and the expectations of ANC visits might be mediating the effects through the factors found associated in this study. Supply side factors like the quality of ANC services, skilled staff, and geographic location of the health centers also mediate their effects through the highlighted factors. Irrespective of the knowledge about the precise mechanism of action, policy makers could focus on improving women’s empowerment, improving women’s education, reducing wealth inequity and facilitating improved utilization of ANC through modifications on the supply side factors such as geographic location and focus on hard to reach women. PMID:28922383

Sex Differences in Timeliness of Reperfusion in Young Patients With ST-Segment-Elevation Myocardial Infarction by Initial Electrocardiographic Characteristics.

PubMed

Gupta, Aakriti; Barrabes, Jose A; Strait, Kelly; Bueno, Hector; Porta-Sánchez, Andreu; Acosta-Vélez, J Gabriel; Lidón, Rosa-Maria; Spatz, Erica; Geda, Mary; Dreyer, Rachel P; Lorenze, Nancy; Lichtman, Judith; D'Onofrio, Gail; Krumholz, Harlan M

2018-03-07

Young women with ST-segment-elevation myocardial infarction experience reperfusion delays more frequently than men. Our aim was to determine the electrocardiographic correlates of delay in reperfusion in young patients with ST-segment-elevation myocardial infarction. We examined sex differences in initial electrocardiographic characteristics among 1359 patients with ST-segment-elevation myocardial infarction in a prospective, observational, cohort study (2008-2012) of 3501 patients with acute myocardial infarction, 18 to 55 years of age, as part of the VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients) study at 103 US and 24 Spanish hospitals enrolling in a 2:1 ratio for women/men. We created a multivariable logistic regression model to assess the relationship between reperfusion delay (door-to-balloon time >90 or >120 minutes for transfer or door-to-needle time >30 minutes) and electrocardiographic characteristics, adjusting for sex, sociodemographic characteristics, and clinical characteristics at presentation. In our study (834 women and 525 men), women were more likely to exceed reperfusion time guidelines than men (42.4% versus 31.5%; P <0.01). In multivariable analyses, female sex persisted as an important factor in exceeding reperfusion guidelines after adjusting for electrocardiographic characteristics (odds ratio, 1.57; 95% CI, 1.15-2.15). Positive voltage criteria for left ventricular hypertrophy and absence of a prehospital ECG were positive predictors of reperfusion delay; and ST elevation in lateral leads was an inverse predictor of reperfusion delay. Sex disparities in timeliness to reperfusion in young patients with ST-segment-elevation myocardial infarction persisted, despite adjusting for initial electrocardiographic characteristics. Left ventricular hypertrophy by voltage criteria and absence of prehospital ECG are strongly positively correlated and ST elevation in lateral leads is negatively correlated with reperfusion delay. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Timing of vasopressor initiation and mortality in septic shock: a cohort study

PubMed Central

2014-01-01

Introduction Despite recent advances in the management of septic shock, mortality remains unacceptably high. Earlier initiation of key therapies including appropriate antimicrobials and fluid resuscitation appears to reduce the mortality in this condition. This study examined whether early initiation of vasopressor therapy is associated with improved survival in fluid therapy-refractory septic shock. Methods Utilizing a well-established database, relevant information including duration of time to vasopressor administration following the initial documentation of recurrent/persistent hypotension associated with septic shock was assessed in 8,670 adult patients from 28 ICUs in Canada, the United States of America, and Saudi Arabia. The primary endpoint was survival to hospital discharge. Secondary endpoints were length of ICU and hospital stay as well as duration of ventilator support and vasopressor dependence. Analysis involved multivariate linear and logistic regression analysis. Results In total, 8,640 patients met the definition of septic shock with time of vasopressor/inotropic initiation documented. Of these, 6,514 were suitable for analysis. The overall unadjusted hospital mortality rate was 53%. Independent mortality correlates included liver failure (odds ratio (OR) 3.46, 95% confidence interval (CI), 2.67 to 4.48), metastatic cancer (OR 1.63, CI, 1.32 to 2.01), AIDS (OR 1.91, CI, 1.29 to 2.49), hematologic malignancy (OR 1.88, CI, 1.46 to 2.41), neutropenia (OR 1.78, CI, 1.27 to 2.49) and chronic hypertension (OR 0.62 CI, 0.52 to 0.73). Delay of initiation of appropriate antimicrobial therapy (OR 1.07/hr, CI, 1.06 to 1.08), age (OR 1.03/yr, CI, 1.02 to 1.03), and Acute Physiology and Chronic Health Evaluation (APACHE) II Score (OR 1.11/point, CI, 1.10 to 1.12) were also found to be significant independent correlates of mortality. After adjustment, only a weak correlation between vasopressor delay and hospital mortality was found (adjusted OR 1.02/hr, 95% CI 1.01 to 1.03, P <0.001). This weak effect was entirely driven by the group of patients with the longest delays (>14.1 hours). There was no significant relationship of vasopressor initiation delay to duration of vasopressor therapy (P = 0.313) and only a trend to longer duration of ventilator support (P = 0.055) among survivors. Conclusion Marked delays in initiation of vasopressor/inotropic therapy are associated with a small increase in mortality risk in patients with septic shock. PMID:24887489

Gender and socio-cultural determinants of delay to diagnosis of TB in Bangladesh, India and Malawi.

PubMed

Gosoniu, G D; Ganapathy, S; Kemp, J; Auer, C; Somma, D; Karim, F; Weiss, M G

2008-07-01

Tuberculosis (TB) control programmes in Bangladesh, India and Malawi. To compare the interval from symptom onset to diagnosis of TB for men and women, and to assess socio-cultural and gender-related features of illness explaining diagnostic delay. Semi-structured Explanatory Model Interview Catalogue (EMIC) interviews were administered to 100 or more patients at each site, assessing categories of distress, perceived causes and help seeking. Based on time from initial symptoms to diagnosis of TB, patients were classified with problem delay (>90 days), timely diagnosis (< or =30 days) or moderate delay. EMIC interview data were analysed to explain problem delay. The median interval from symptom onset to diagnosis was longest in India and shortest in Malawi. With adjustment for confounding, female sex (Bangladesh), and status of married woman (India) and housewife (Malawi) were associated with problem delay. Prominent non-specific symptoms--chest pain (Bangladesh) and breathlessness (Malawi)--were also significant. Cough in India, widely associated with TB, was associated with timely diagnosis. Sanitation as a perceived cause linked to poor urban conditions was associated with delayed diagnosis in India. Specific prior help seeking with circuitous referral patterns was identified. The study identified gender- and illness-related features of diagnostic delay. Further research distinguishing patient and provider delay is needed.

Improving Procedure Start Times and Decreasing Delays in Interventional Radiology: A Department's Quality Improvement Initiative.

PubMed

Villarreal, Monica C; Rostad, Bradley S; Wright, Richard; Applegate, Kimberly E

2015-12-01

To identify and reduce reasons for delays in procedure start times, particularly the first cases of the day, within the interventional radiology (IR) divisions of the Department of Radiology using principles of continuous quality improvement. An interdisciplinary team representative of the IR and preprocedure/postprocedure care area (PPCA) health care personnel, managers, and data analysts was formed. A standardized form was used to document both inpatient and outpatient progress through the PPCA and IR workflow in six rooms and to document reasons for delays. Data generated were used to identify key problems areas, implement improvement interventions, and monitor their effects. Project duration was 6 months. The average number of on-time starts for the first case of the day increased from 23% to 56% (P value < .01). The average number of on-time, scheduled outpatients increased from 30% to 45% (P value < .01). Patient wait time to arrive at treatment room once they were ready for their procedure was reduced on average by 10 minutes (P value < .01). Patient care delay duration per 100 patients was reduced from 30.3 to 21.6 hours (29% reduction). Number of patient care delays per 100 patients was reduced from 46.6 to 40.1 (17% reduction). Top reasons for delay included waiting for consent (26% of delays duration) and laboratory tests (12%). Many complex factors contribute to procedure start time delays within an IR practice. A data-driven and patient-centered, interdisciplinary team approach was effective in reducing delays in IR. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

Lens Model and Time Delay Predictions for the Sextuply Lensed Quasar SDSS J2222+2745

NASA Astrophysics Data System (ADS)

Sharon, Keren; Bayliss, Matthew B.; Dahle, Håkon; Florian, Michael K.; Gladders, Michael D.; Johnson, Traci L.; Paterno-Mahler, Rachel; Rigby, Jane R.; Whitaker, Katherine E.; Wuyts, Eva

2017-01-01

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image of the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found τAB = 47.7 ± 6.0 days and τAC = -722 ± 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are τAD = 502 ± 68 days, τAE = 611 ± 75 days, and τAF = 415 ± 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift, indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-13337.

Assessing delay and lag in sagittal trunk control using a tracking task.

PubMed

Reeves, N Peter; Luis, Abraham; Chan, Elizabeth C; Sal Y Rosas, Victor G; Tanaka, Martin L

2018-05-17

Slower trunk muscle responses are linked to back pain and injury. Unfortunately, clinical assessments of spine function do not objectively evaluate this important attribute, which reflects speed of trunk control. Speed of trunk control can be parsed into two components: (1) delay, the time it takes to initiate a movement, and (2) lag, the time it takes to execute a movement once initiated. The goal of this study is to demonstrate a new approach to assess delay and lag in trunk control using a simple tracking task. Ten healthy subjects performed four blocks of six trials of trunk tracking in the sagittal plane. Delay and lag were estimated by modeling trunk control for predictable and unpredictable (control mode) trunk movements in flexion and extension (control direction) at movement amplitudes of 2°, 4°, and 6° (control amplitude). The main effect of control mode, direction, and amplitude of movement were compared between trial blocks to assess secondary influencers (e.g., fatigue). Only control mode was consistent across trial blocks with predictable movements being faster than unpredictable for both delay and lag. Control direction and amplitude effects on delay and lag were consistent across the first two trial blocks and less consistent in later blocks. Given the heterogeneity in the presentation of back pain, clinical assessment of trunk control should include different control modes, directions, and amplitudes. To reduce testing time and the influence of fatigue, we recommend six trials to assess trunk control. Copyright © 2018 Elsevier Ltd. All rights reserved.

Femtosecond laser spectroscopy of the rhodopsin photochromic reaction: a concept for ultrafast optical molecular switch creation (ultrafast reversible photoreaction of rhodopsin).

PubMed

Smitienko, Olga; Nadtochenko, Victor; Feldman, Tatiana; Balatskaya, Maria; Shelaev, Ivan; Gostev, Fedor; Sarkisov, Oleg; Ostrovsky, Mikhail

2014-11-11

Ultrafast reverse photoreaction of visual pigment rhodopsin in the femtosecond time range at room temperature is demonstrated. Femtosecond two-pump probe experiments with a time resolution of 25 fs have been performed. The first рump pulse at 500 nm initiated cis-trans photoisomerization of rhodopsin chromophore, 11-cis retinal, which resulted in the formation of the primary ground-state photoproduct within a mere 200 fs. The second pump pulse at 620 nm with a varying delay of 200 to 3750 fs relative to the first рump pulse, initiated the reverse phototransition of the primary photoproduct to rhodopsin. The results of this photoconversion have been observed on the differential spectra obtained after the action of two pump pulses at a time delay of 100 ps. It was found that optical density decreased at 560 nm in the spectral region of bathorhodopsin absorption and increased at 480 nm, where rhodopsin absorbs. Rhodopsin photoswitching efficiency shows oscillations as a function of the time delay between two рump pulses. The quantum yield of reverse photoreaction initiated by the second pump pulse falls within the range 15%±1%. The molecular mechanism of the ultrafast reversible photoreaction of visual pigment rhodopsin may be used as a concept for the development of an ultrafast optical molecular switch.

Effect of sprayer output volume and adjuvants on efficacy of clove oil for weed control in organic Vidalia sweet onion

USDA-ARS?s Scientific Manuscript database

Timely cultivation with a tine weeder is the primary tool for successful weed control in organic Vidalia® sweet onion, but conditions frequently arise that delay the initial cultivation. Weeds that emerge during the delay are not effectively controlled by cultivation and herbicides derived from nat...

Immediate newborn care practices delay thermoregulation and breastfeeding initiation

PubMed Central

Sobel, Howard L; Silvestre, Maria Asuncion A; Mantaring, Jacinto Blas V; Oliveros, Yolanda E; Nyunt-U, Soe

2011-01-01

Aim A deadly nosocomial outbreak in a Philippine hospital drew nationwide attention to neonatal sepsis. Together with specific infection control measures, interventions that protect newborns against infection-related mortality include drying, skin-to-skin contact, delayed cord clamping, breastfeeding initiation and delayed bathing. This evaluation characterized hospital care in the first hours of life with the intent to drive policy change, strategic planning and hospital reform. Methods Trained physicians observed 481 consecutive deliveries in 51 hospitals using a standardized tool to record practices and timing of immediate newborn care procedures. Results Drying, weighing, eye care and vitamin K injections were performed in more than 90% of newborns. Only 9.6% were allowed skin-to-skin contact. Interventions were inappropriately sequenced, e.g. immediate cord clamping (median 12 sec), delayed drying (96.5%) and early bathing (90.0%). While 68.2% were put to the breast, they were separated two minutes later. Unnecessary suctioning was performed in 94.9%. Doctors trained in neonatal resuscitation were 2.5 (1.1–5.7) times more likely to unnecessarily suction vigorous newborns. Two per cent died and 5.7% developed sepsis/pneumonia. Conclusions This minute-by-minute observational assessment revealed that performance and timing of immediate newborn care interventions are below WHO standards and deprive newborns of basic protections against infection and death. PMID:21375583

Efficient rejection-based simulation of biochemical reactions with stochastic noise and delays

NASA Astrophysics Data System (ADS)

Thanh, Vo Hong; Priami, Corrado; Zunino, Roberto

2014-10-01

We propose a new exact stochastic rejection-based simulation algorithm for biochemical reactions and extend it to systems with delays. Our algorithm accelerates the simulation by pre-computing reaction propensity bounds to select the next reaction to perform. Exploiting such bounds, we are able to avoid recomputing propensities every time a (delayed) reaction is initiated or finished, as is typically necessary in standard approaches. Propensity updates in our approach are still performed, but only infrequently and limited for a small number of reactions, saving computation time and without sacrificing exactness. We evaluate the performance improvement of our algorithm by experimenting with concrete biological models.

Delayed risk stratification, to include the response to initial treatment (surgery and radioiodine ablation), has better outcome predictivity in differentiated thyroid cancer patients.

PubMed

Castagna, Maria Grazia; Maino, Fabio; Cipri, Claudia; Belardini, Valentina; Theodoropoulou, Alexandra; Cevenini, Gabriele; Pacini, Furio

2011-09-01

After initial treatment, differentiated thyroid cancer (DTC) patients are stratified as low and high risk based on clinical/pathological features. Recently, a risk stratification based on additional clinical data accumulated during follow-up has been proposed. To evaluate the predictive value of delayed risk stratification (DRS) obtained at the time of the first diagnostic control (8-12 months after initial treatment). We reviewed 512 patients with DTC whose risk assessment was initially defined according to the American (ATA) and European Thyroid Association (ETA) guidelines. At the time of the first control, 8-12 months after initial treatment, patients were re-stratified according to their clinical status: DRS. Using DRS, about 50% of ATA/ETA intermediate/high-risk patients moved to DRS low-risk category, while about 10% of ATA/ETA low-risk patients moved to DRS high-risk category. The ability of the DRS to predict the final outcome was superior to that of ATA and ETA. Positive and negative predictive values for both ATA (39.2 and 90.6% respectively) and ETA (38.4 and 91.3% respectively) were significantly lower than that observed with the DRS (72.8 and 96.3% respectively, P<0.05). The observed variance in predicting final outcome was 25.4% for ATA, 19.1% for ETA, and 62.1% for DRS. Delaying the risk stratification of DTC patients at a time when the response to surgery and radioiodine ablation is evident allows to better define individual risk and to better modulate the subsequent follow-up.

Dissolvable fluidic time delays for programming multi-step assays in instrument-free paper diagnostics.

PubMed

Lutz, Barry; Liang, Tinny; Fu, Elain; Ramachandran, Sujatha; Kauffman, Peter; Yager, Paul

2013-07-21

Lateral flow tests (LFTs) are an ingenious format for rapid and easy-to-use diagnostics, but they are fundamentally limited to assay chemistries that can be reduced to a single chemical step. In contrast, most laboratory diagnostic assays rely on multiple timed steps carried out by a human or a machine. Here, we use dissolvable sugar applied to paper to create programmable flow delays and present a paper network topology that uses these time delays to program automated multi-step fluidic protocols. Solutions of sucrose at different concentrations (10-70% of saturation) were added to paper strips and dried to create fluidic time delays spanning minutes to nearly an hour. A simple folding card format employing sugar delays was shown to automate a four-step fluidic process initiated by a single user activation step (folding the card); this device was used to perform a signal-amplified sandwich immunoassay for a diagnostic biomarker for malaria. The cards are capable of automating multi-step assay protocols normally used in laboratories, but in a rapid, low-cost, and easy-to-use format.

Dissolvable fluidic time delays for programming multi-step assays in instrument-free paper diagnostics

PubMed Central

Lutz, Barry; Liang, Tinny; Fu, Elain; Ramachandran, Sujatha; Kauffman, Peter; Yager, Paul

2013-01-01

Lateral flow tests (LFTs) are an ingenious format for rapid and easy-to-use diagnostics, but they are fundamentally limited to assay chemistries that can be reduced to a single chemical step. In contrast, most laboratory diagnostic assays rely on multiple timed steps carried out by a human or a machine. Here, we use dissolvable sugar applied to paper to create programmable flow delays and present a paper network topology that uses these time delays to program automated multi-step fluidic protocols. Solutions of sucrose at different concentrations (10-70% of saturation) were added to paper strips and dried to create fluidic time delays spanning minutes to nearly an hour. A simple folding card format employing sugar delays was shown to automate a four-step fluidic process initiated by a single user activation step (folding the card); this device was used to perform a signal-amplified sandwich immunoassay for a diagnostic biomarker for malaria. The cards are capable of automating multi-step assay protocols normally used in laboratories, but in a rapid, low-cost, and easy-to-use format. PMID:23685876

Goodwin accelerator model revisited with fixed time delays

NASA Astrophysics Data System (ADS)

Matsumoto, Akio; Merlone, Ugo; Szidarovszky, Ferenc

2018-05-01

Dynamics of Goodwin's accelerator business cycle model is reconsidered. The model is characterized by a nonlinear accelerator and an investment time delay. The role of the nonlinearity for the birth of persistent oscillations is fully discussed in the existing literature. On the other hand, not much of the role of the delay has yet been revealed. The purpose of this paper is to show that the delay really matters. In the original framework of Goodwin [6], it is first demonstrated that there is a threshold value of the delay: limit cycles arise for smaller values than the threshold and so do sawtooth oscillations for larger values. In the extended framework in which a consumption or saving delay, in addition to the investment delay, is introduced, three main results are demonstrated under assumption of the identical length of investment and consumption delays. The dynamics with consumption delay is basically the same as that of the single delay model. Second, in the case of saving delay, the steady state can coexist with the stable and unstable limit cycles in the stable case. Third, in the unstable case, there is an interval of delay in which the limit cycle or the sawtooth oscillation emerges depending on the choice of the constant initial function.

Dynamics of landslide model with time delay and periodic parameter perturbations

NASA Astrophysics Data System (ADS)

Kostić, Srđan; Vasović, Nebojša; Franović, Igor; Jevremović, Dragutin; Mitrinovic, David; Todorović, Kristina

2014-09-01

In present paper, we analyze the dynamics of a single-block model on an inclined slope with Dieterich-Ruina friction law under the variation of two new introduced parameters: time delay Td and initial shear stress μ. It is assumed that this phenomenological model qualitatively simulates the motion along the infinite creeping slope. The introduction of time delay is proposed to mimic the memory effect of the sliding surface and it is generally considered as a function of history of sliding. On the other hand, periodic perturbation of initial shear stress emulates external triggering effect of long-distant earthquakes or some non-natural vibration source. The effects of variation of a single observed parameter, Td or μ, as well as their co-action, are estimated for three different sliding regimes: β < 1, β = 1 and β > 1, where β stands for the ratio of long-term to short-term stress changes. The results of standard local bifurcation analysis indicate the onset of complex dynamics for very low values of time delay. On the other side, numerical approach confirms an additional complexity that was not observed by local analysis, due to the possible effect of global bifurcations. The most complex dynamics is detected for β < 1, with a complete Ruelle-Takens-Newhouse route to chaos under the variation of Td, or the co-action of both parameters Td and μ. These results correspond well with the previous experimental observations on clay and siltstone with low clay fraction. In the same regime, the perturbation of only a single parameter, μ, renders the oscillatory motion of the block. Within the velocity-independent regime, β = 1, the inclusion and variation of Td generates a transition to equilibrium state, whereas the small oscillations of μ induce oscillatory motion with decreasing amplitude. The co-action of both parameters, in the same regime, causes the decrease of block's velocity. As for β > 1, highly-frequent, limit-amplitude oscillations of initial stress give rise to oscillatory motion. Also for β > 1, in case of perturbing only the initial shear stress, with smaller amplitude, velocity of the block changes exponentially fast. If the time delay is introduced, besides the stress perturbation, within the same regime, the co-action of Td (Td < 0.1) and small oscillations of μ induce the onset of deterministic chaos.

Delay of insulin initiation in patients with type 2 diabetes mellitus inadequately controlled with oral hypoglycemic agents (analysis of patient- and physician-related factors): A prospective observational DIPP-FACTOR study in Korea.

PubMed

Kim, Sin Gon; Kim, Nam Hoon; Ku, Bon Jeong; Shon, Ho Sang; Kim, Doo Man; Park, Tae Sun; Kim, Yong-Seong; Kim, In Joo; Choi, Dong Seop

2017-05-01

To assess the time to initiation of insulin therapy, and concurrently investigate both patient- and physician-related factors associated with delaying insulin therapy in Korean patients with type 2 diabetes uncontrolled by oral hypoglycemic agents (OHAs). This prospective, observational disease registry study was carried out across 69 centers in Korea. Type 2 diabetes patients who had received two or more OHAs within the past 5 years, had a glycated hemoglobin ≥8% in the past 6 months and had not received insulin were included. Data recorded on data collection forms during a 12-month period were analyzed. Of 2168 patients enrolled, 1959 were evaluated and classified as the insulin-initiated or insulin-delayed group. Insulin was prescribed for just 20% of the patients during a 1-year follow-up period, and less than half (44.5%) of the patients who were taking two OHAs started insulin after 6 years. Patient-related factors for delay in insulin initiation included older age, shorter duration of diabetes and lower glycated hemoglobin. Physician-related factors included age (~50 to <60 years), sex (women) and number (<1000) of patients consulted per month. Patient refusal (33.6%) and physicians' concerns of patient non-compliance (26.5%) were the major physician-reported reasons for delaying insulin therapy. Inconvenience of insulin therapy (51.6%) and fear of injection (48.2%) were the major reasons for patient refusal. Insulin initiation is delayed in patients with type 2 diabetes uncontrolled by two or more OHAs in Korea. Patient- and physician-related factors associated with this delay need to be addressed for better diabetes management. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

The Emergence and Propagation of a Phase Boundary in an Elastic Bar.

DTIC Science & Technology

1983-06-01

differential- delay equations, where the delay 1s unknown. We first present a short- time analysis of this system in order to describe the emergence and Initial...ft, which arise on x=0 at progressively earlier times ; see Fig. 8. This geometric state of affairs is described by the inequalities : TT^"^^WF...t))) < 0 , (6.7) so that e(s(t)~,t) and v(s(t)",t) are decreasing with time . We have already observed that the first Inequality In (6.2

Dilution cycle control for an absorption refrigeration system

DOEpatents

Reimann, Robert C.

1984-01-01

A dilution cycle control system for an absorption refrigeration system is disclosed. The control system includes a time delay relay for sensing shutdown of the absorption refrigeration system and for generating a control signal only after expiration of a preselected time period measured from the sensed shutdown of the absorption refrigeration system, during which the absorption refrigeration system is not restarted. A dilution cycle for the absorption refrigeration system is initiated in response to generation of a control signal by the time delay relay. This control system is particularly suitable for use with an absorption refrigeration system which is frequently cycled on and off since the time delay provided by the control system prevents needless dilution of the absorption refrigeration system when the system is turned off for only a short period of time and then is turned back on.

Factors associated with delay in trauma team activation and impact on patient outcomes.

PubMed

Connolly, Rory; Woo, Michael Y; Lampron, Jacinthe; Perry, Jeffrey J

2017-09-05

Trauma code activation is initiated by emergency physicians using physiological and anatomical criteria, mechanism of injury, and patient demographic factors. Our objective was to identify factors associated with delayed trauma team activation. We assessed consecutive cases from a regional trauma database from January 2008 to March 2014. We defined a delay in trauma code activation as a time greater than 30 minutes from the time of arrival. We conducted univariate analysis for factors potentially influencing trauma team activation, and we subsequently used multiple logistic regression analysis models for delayed activation in relation to mortality, length of stay, and time to operative management. Patients totalling 846 were included for our analysis; 4.1% (35/846) of trauma codes were activated after 30 minutes. Mean age was 40.8 years in the early group versus 49.2 in the delayed group (p=0.01). Patients were over age 70 years in 7.6% in the early activation group versus 17.1% in the delayed group (p=0.04). There was no significant difference in sex, type of injury, injury severity, or time from injury between the two groups. There was no significant difference in mortality, median length of stay, or median time to operative management. Delayed activation is linked with increasing age with no clear link to increased mortality. Given the severe injuries in the delayed cohort that required activation of the trauma team, further emphasis on the older trauma patient and interventions to recognize this vulnerable population should be made.

Association between delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan.

PubMed

Kitamura, Shingo; Enomoto, Minori; Kamei, Yuichi; Inada, Naoko; Moriwaki, Aiko; Kamio, Yoko; Mishima, Kazuo

2015-03-13

Although delayed sleep timing causes many socio-psycho-biological problems such as sleep loss, excessive daytime sleepiness, obesity, and impaired daytime neurocognitive performance in adults, there are insufficient data showing the clinical significance of a 'night owl lifestyle' in early life. This study examined the association between habitual delayed bedtime and sleep-related problems among community-dwelling 2-year-old children in Japan. Parents/caregivers of 708 community-dwelling 2-year-old children in Nishitokyo City, Tokyo, participated in the study. The participants answered a questionnaire to evaluate their child's sleep habits and sleep-related problems for the past 1 month. Of the 425 children for whom complete data were collected, 90 (21.2%) went to bed at 22:00 or later. Children with delayed bedtime showed significantly more irregular bedtime, delayed wake time, shorter total sleep time, and difficulty in initiating and terminating sleep. Although this relationship indicated the presence of sleep debt in children with delayed bedtime, sleep onset latency did not differ between children with earlier bedtime and those with delayed bedtime. Rather, delayed bedtime was significantly associated with bedtime resistance and problems in the morning even when adjusting for nighttime and daytime sleep time. Even in 2-year-old children, delayed bedtime was associated with various sleep-related problems. The causal factors may include diminished homeostatic sleep drive due to prolonged daytime nap as well as diurnal preference (morning or night type) regulated by the biological clock.

Components of visual search in childhood-onset schizophrenia and attention-deficit/hyperactivity disorder.

PubMed

Karatekin, C; Asarnow, R F

1998-10-01

This study tested the hypotheses that visual search impairments in schizophrenia are due to a delay in initiation of search or a slow rate of serial search. We determined the specificity of these impairments by comparing children with schizophrenia to children with attention-deficit hyperactivity disorder (ADHD) and age-matched normal children. The hypotheses were tested within the framework of feature integration theory by administering children tasks tapping parallel and serial search. Search rate was estimated from the slope of the search functions, and duration of the initial stages of search from time to make the first saccade on each trial. As expected, manual response times were elevated in both clinical groups. Contrary to expectation, ADHD, but not schizophrenic, children were delayed in initiation of serial search. Finally, both groups showed a clear dissociation between intact parallel search rates and slowed serial search rates.

Improved survival in patients enrolled promptly into remote monitoring following cardiac implantable electronic device implantation.

PubMed

Mittal, Suneet; Piccini, Jonathan P; Snell, Jeff; Prillinger, Julie B; Dalal, Nirav; Varma, Niraj

2016-08-01

Guidelines advocate remote monitoring (RM) in patients with a cardiac implantable electronic device (CIED). However, it is not known when RM should be initiated. We hypothesized that prompt initiation of RM (within 91 days of implant) is associated with improved survival compared to delayed initiation. This retrospective, national, observational cohort study evaluated patients receiving new implants of market-released St. Jude Medical™ pacemakers (PM), implantable cardioverter defibrillators (ICD), and cardiac resynchronization therapy (CRT) devices. Patients were assigned to one of two groups: an "RM Prompt" group, in which RM was initiated within 91 days of implant; and an "RM Delayed" group, in which RM was initiated >91 days but ≤365 days of implant. The primary endpoint was all-cause mortality. The cohort included 106,027 patients followed for a mean of 2.6 ± 0.9 years. Overall, 47,014 (44 %) patients had a PM, 31,889 (30 %) patients had an ICD, 24,005 (23 %) patients had a CRT-D, and 3119 (3 %) patients had a CRT-P. Remote monitoring was initiated promptly (median 4 weeks [IQR 2, 8 weeks]) in 66,070 (62 %) patients; in the other 39,957 (38 %) patients, RM initiation was delayed (median 24 weeks [IQR 18, 34 weeks]). In comparison to delayed initiation, prompt initiation of RM was associated with a lower mortality rate (4023 vs. 4679 per 100,000 patient-years, p < 0.001) and greater adjusted survival (HR 1.18 [95 % CI 1.13-1.22], p < 0.001). Our data, for the first time, show improved survival in patients enrolled promptly into RM following CIED implantation. This advantage was observed across all CIED device types.

Early infant diagnosis of HIV in Myanmar: call for innovative interventions to improve uptake and reduce turnaround time.

PubMed

Thiha, Soe; Shewade, Hemant Deepak; Philip, Sairu; Aung, Thet Ko; Kyaw, Nang Thu Thu; Oo, Myo Minn; Kyaw, Khine Wut Yee; War, May Wint; Oo, Htun Nyunt

2017-01-01

In collaboration with the national AIDS program, early infant diagnosis (EID) is implemented by Integrated HIV Care (IHC) program through its anti-retroviral therapy (ART) centers across 10 cities in five states and regions of Myanmar. Blood samples from the ART centers are sent using public transport to a centralized PCR facility. Among HIV-exposed babies <9 months at enrolment into IHC program (2013-15), to describe the EID cascade (enrolment, sample collection for PCR, result receipt by mother, HIV diagnosis and ART initiation) and factors associated with delayed (>8 weeks of age) or no blood sample collection for EID. Retrospective cohort study involving record review. A predictive poisson regression model with robust variance estimates was fitted for risk factors of delayed or no sample collection. Of 1349 babies, 523 (39%) of the babies' mothers were on ART before pregnancy. Timely uptake of EID (<8 weeks of age) was 47% (633/1349); sample collection was delayed in 27% (367/1349) and not done in 26% (349/1349) babies. Among samples collected (n = 1000), 667 results were received by the mother; 52 (5%) were HIV-infected; among them 42 (81%) were initiated on ART. Median (IQR) turnaround time from sample collection to result receipt by mother and time to initiate ART from result receipt by mother was 7 (4,12) and 8.5 (6,16) weeks, respectively. Mothers not on ART before pregnancy and distance of ART center from PCR facility (more than 128 km) were the risk factors of delayed or no sample collection. Improving provision of ART to mothers (through universal 'test and treat') is urgently required, which has the potential to improve the timely uptake of EID as well. Interventions to reduce turnaround times, like point of care EID testing and/or systematic use of mobile technology to communicate results, are needed.

Delayed and Unreported Drug-Susceptibility Testing Results in the US National Tuberculosis Surveillance System, 1993-2014.

PubMed

Jones, Jefferson Michael; Armstrong, Lori R

Drug-susceptibility testing (DST) of Mycobacterium tuberculosis is necessary for identifying drug-resistant tuberculosis, administering effective treatment regimens, and preventing the spread of drug-resistant tuberculosis. DST is recommended for all culture-confirmed cases of tuberculosis. We examined trends in delayed and unreported DST results in the Centers for Disease Control and Prevention's National Tuberculosis Surveillance System. We analyzed culture-confirmed tuberculosis cases reported to the National Tuberculosis Surveillance System during 1993-2014 for annual trends in initial DST reporting for first-line antituberculosis drugs and trends in on-time, delayed, and unreported results. We defined on-time reporting as DST results received during the same calendar year in which the patient's case was reported or ≤4 months after the calendar year ended and delayed reporting as DST results received after the calendar year. We compared cases with on-time, delayed, and unreported DST results by patient and tuberculosis program characteristics. The proportion of cases with reported results for all first-line antituberculosis drugs increased during 1993-2011. Reporting of pyrazinamide results was lower than reporting of other drugs. However, during 2000-2012, of 134 787 tuberculosis cases reported to the National Tuberculosis Surveillance System, reporting was on time for 125 855 (93.4%) cases, delayed for 5332 (4.0%) cases, and unreported for 3600 (2.7%) cases. Despite increases in the proportion of cases with on-time DST results, delayed and unreported results persisted. Carefully assessing causes for delayed and unreported DST results should lead to more timely reporting of drug-resistant tuberculosis.

Generalization of Turbulent Pair Dispersion to Large Initial Separations

NASA Astrophysics Data System (ADS)

Shnapp, Ron; Liberzon, Alex; International Collaboration for Turbulence Research

2018-06-01

We present a generalization of turbulent pair dispersion to large initial separations (η

Automated delay measurement system for an Earth station for Two-Way Satellite Time and Frequency Transfer

NASA Technical Reports Server (NTRS)

Dejong, Gerrit; Polderman, Michel C.

1995-01-01

The measurement of the difference of the transmit and receive delays of the signals in a Two-Way Satellite Time and Frequency Transfer (TWSTFT) Earth station is crucial for its nanosecond time transfer capability. Also, the monitoring of the change of this delay difference with time, temperature, humidity, or barometric pressure is important for improving the TWSTFT capabilities. An automated system for this purpose has been developed from the initial design at NMi-VSL. It calibrates separately the transmit and receive delays in cables, amplifiers, upconverters and downconverters, and antenna feeds. The obtained results can be applied as corrections to the TWSTFT measurement when, before and after a measurement session, a calibration session is performed. Preliminary results obtained at NMi-VSL will be shown. Also, if available, the results of a manual version of the system that is planned to be circulated in Sept. 1994 together with a USNO portable station on a calibration trip to European TWSTFT Earth stations.

Using an iPad Application to Promote Early Literacy Development in Young Children with Disabilities

ERIC Educational Resources Information Center

Chai, Zhen; Vail, Cynthia O.; Ayres, Kevin M.

2015-01-01

This investigation evaluated the effects of using an iPad application to teach young children with developmental delays to receptively identify initial phonemes through 0- to 5-s constant time delay procedures in the context of a multiple-probe design across three sets of behaviors and replicated across three students. The dependent variable was…

Primary Realignment for Pelvic Fracture Urethral Injury Is Associated With Prolonged Time to Urethroplasty and Increased Stenosis Complexity.

PubMed

Horiguchi, Akio; Shinchi, Masayuki; Masunaga, Ayako; Okubo, Kazuki; Kawamura, Kazuki; Ojima, Kenichiro; Ito, Keiichi; Asano, Tomohiko; Azuma, Ryuichi

2017-10-01

To compare the clinical courses of patients with pelvic fracture urethral injury (PFUI) according to initial management strategy. We reviewed the clinical courses of 63 patients with PFUI who were initially treated elsewhere and underwent delayed anastomotic urethroplasty by a single surgeon between 2008 and 2015. Patients were grouped according to their initial treatment: by suprapubic tube placement alone (49 patients, SPT group) or primary realignment (14 patients, PR group). Time to urethroplasty was defined as the period between injury and delayed urethroplasty. Clinical data regarding the status of urethral stenosis, urethroplasty procedure, and treatment outcome were analyzed. The mean time to urethroplasty in the PR group was about 3 times than that in the SPT group (133 months vs 47 months, P = .035). Fifty percent of the PR group (7 of 14) had a history of repeated urethrotomy or dilation before referral, a percentage significantly higher than that of the SPT group (20.4%, 10 of 49, P = .027). The percentage of patients having a false passage and iatrogenic scar was significantly higher in the PR group (42.9% vs 16.3%, P = .035), but there was no significant between-group difference in urethral stenosis length, operative time, operative blood loss, or the percentage of patients requiring inferior pubectomy or urethral rerouting. PR does not facilitate delayed urethroplasty, and patients who undergo PR are at high risk of having a more complicated stenosis and longer time to urethroplasty, presumably because of repeated transurethral procedures. Copyright © 2017 Elsevier Inc. All rights reserved.

Interaction Between Strategic and Local Traffic Flow Controls

NASA Technical Reports Server (NTRS)

Grabbe, Son; Sridhar, Banavar; Mukherjee, Avijit; Morando, Alexander

2010-01-01

The loosely coordinated sets of traffic flow management initiatives that are operationally implemented at the national- and local-levels have the potential to under, over, and inconsistently control flights. This study is designed to explore these interactions through fast-time simulations with an emphasis on identifying inequitable situations in which flights receive multiple uncoordinated delays. Two operationally derived scenarios were considered in which flights arriving into the Dallas/Fort Worth International Airport were first controlled at the national-level, either with a Ground Delay Program or a playbook reroute. These flights were subsequently controlled at the local level. The Traffic Management Advisor assigned them arrival scheduling delays. For the Ground Delay Program scenarios, between 51% and 53% of all arrivals experience both pre-departure delays from the Ground Delay Program and arrival scheduling delays from the Traffic Management Advisor. Of the subset of flights that received multiple delays, between 5.7% and 6.4% of the internal departures were first assigned a pre-departure delay by the Ground Delay Program, followed by a second pre-departure delay as a result of the arrival scheduling. For the playbook reroute scenario, Dallas/Fort Worth International Airport arrivals were first assigned pre-departure reroutes based on the MW_2_DALLAS playbook plan, and were subsequently assigned arrival scheduling delays by the Traffic Management Advisor. Since the airport was operating well below capacity when the playbook reroute was in effect, only 7% of the arrivals were observed to receive both rerouting and arrival scheduling delays. Findings from these initial experiments confirm field observations that Ground Delay Programs operated in conjunction with arrival scheduling can result in inequitable situations in which flights receive multiple uncoordinated delays.

Effects of intrinsic stochasticity on delayed reaction-diffusion patterning systems.

PubMed

Woolley, Thomas E; Baker, Ruth E; Gaffney, Eamonn A; Maini, Philip K; Seirin-Lee, Sungrim

2012-05-01

Cellular gene expression is a complex process involving many steps, including the transcription of DNA and translation of mRNA; hence the synthesis of proteins requires a considerable amount of time, from ten minutes to several hours. Since diffusion-driven instability has been observed to be sensitive to perturbations in kinetic delays, the application of Turing patterning mechanisms to the problem of producing spatially heterogeneous differential gene expression has been questioned. In deterministic systems a small delay in the reactions can cause a large increase in the time it takes a system to pattern. Recently, it has been observed that in undelayed systems intrinsic stochasticity can cause pattern initiation to occur earlier than in the analogous deterministic simulations. Here we are interested in adding both stochasticity and delays to Turing systems in order to assess whether stochasticity can reduce the patterning time scale in delayed Turing systems. As analytical insights to this problem are difficult to attain and often limited in their use, we focus on stochastically simulating delayed systems. We consider four different Turing systems and two different forms of delay. Our results are mixed and lead to the conclusion that, although the sensitivity to delays in the Turing mechanism is not completely removed by the addition of intrinsic noise, the effects of the delays are clearly ameliorated in certain specific cases.

Reducing Bottlenecks to Improve the Efficiency of the Lung Cancer Care Delivery Process: A Process Engineering Modeling Approach to Patient-Centered Care.

PubMed

Ju, Feng; Lee, Hyo Kyung; Yu, Xinhua; Faris, Nicholas R; Rugless, Fedoria; Jiang, Shan; Li, Jingshan; Osarogiagbon, Raymond U

2017-12-01

The process of lung cancer care from initial lesion detection to treatment is complex, involving multiple steps, each introducing the potential for substantial delays. Identifying the steps with the greatest delays enables a focused effort to improve the timeliness of care-delivery, without sacrificing quality. We retrospectively reviewed clinical events from initial detection, through histologic diagnosis, radiologic and invasive staging, and medical clearance, to surgery for all patients who had an attempted resection of a suspected lung cancer in a community healthcare system. We used a computer process modeling approach to evaluate delays in care delivery, in order to identify potential 'bottlenecks' in waiting time, the reduction of which could produce greater care efficiency. We also conducted 'what-if' analyses to predict the relative impact of simulated changes in the care delivery process to determine the most efficient pathways to surgery. The waiting time between radiologic lesion detection and diagnostic biopsy, and the waiting time from radiologic staging to surgery were the two most critical bottlenecks impeding efficient care delivery (more than 3 times larger compared to reducing other waiting times). Additionally, instituting surgical consultation prior to cardiac consultation for medical clearance and decreasing the waiting time between CT scans and diagnostic biopsies, were potentially the most impactful measures to reduce care delays before surgery. Rigorous computer simulation modeling, using clinical data, can provide useful information to identify areas for improving the efficiency of care delivery by process engineering, for patients who receive surgery for lung cancer.

The influence of procedure delay on resource use: a national study of patients with open tibial fracture.

PubMed

Sears, Erika Davis; Burke, James F; Davis, Matthew M; Chung, Kevin C

2013-03-01

The purpose of this study was to (1) understand national variation in delay of emergency procedures in patients with open tibial fracture at the hospital level and (2) compare length of stay and cost in patients cared for at the best- and worst-performing hospitals for delay. The authors retrospectively analyzed the 2003 to 2009 Nationwide Inpatient Sample. Adult patients with open tibial fracture were included. Hospital probability of delay in performing emergency procedures beyond the day of admission was calculated. Multilevel linear regression random-effects models were created to evaluate the relationship between the treating hospital's tendency for delay (in quartiles) and the log-transformed outcomes of length of stay and cost. The final sample included 7029 patients from 332 hospitals. Patients treated at hospitals in the fourth (worst) quartile for delay were estimated to have 12 percent (95 percent CI, 2 to 21 percent) higher cost compared with patients treated at hospitals in the first quartile. In addition, patients treated at hospitals in the fourth quartile had an estimated 11 percent (95 percent CI, 4 to 17 percent) longer length of stay compared with patients treated at hospitals in the first quartile. Patients with open tibial fracture treated at hospitals with more timely initiation of surgical care had lower cost and shorter length of stay than patients treated at hospitals with less timely initiation of care. Policies directed toward mitigating variation in care may reduce unnecessary waste.

Efficient rejection-based simulation of biochemical reactions with stochastic noise and delays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thanh, Vo Hong, E-mail: vo@cosbi.eu; Priami, Corrado, E-mail: priami@cosbi.eu; Department of Mathematics, University of Trento

2014-10-07

We propose a new exact stochastic rejection-based simulation algorithm for biochemical reactions and extend it to systems with delays. Our algorithm accelerates the simulation by pre-computing reaction propensity bounds to select the next reaction to perform. Exploiting such bounds, we are able to avoid recomputing propensities every time a (delayed) reaction is initiated or finished, as is typically necessary in standard approaches. Propensity updates in our approach are still performed, but only infrequently and limited for a small number of reactions, saving computation time and without sacrificing exactness. We evaluate the performance improvement of our algorithm by experimenting with concretemore » biological models.« less

The Strong Lensing Time Delay Challenge (2014)

NASA Astrophysics Data System (ADS)

Liao, Kai; Dobler, G.; Fassnacht, C. D.; Treu, T.; Marshall, P. J.; Rumbaugh, N.; Linder, E.; Hojjati, A.

2014-01-01

Time delays between multiple images in strong lensing systems are a powerful probe of cosmology. At the moment the application of this technique is limited by the number of lensed quasars with measured time delays. However, the number of such systems is expected to increase dramatically in the next few years. Hundred such systems are expected within this decade, while the Large Synoptic Survey Telescope (LSST) is expected to deliver of order 1000 time delays in the 2020 decade. In order to exploit this bounty of lenses we needed to make sure the time delay determination algorithms have sufficiently high precision and accuracy. As a first step to test current algorithms and identify potential areas for improvement we have started a "Time Delay Challenge" (TDC). An "evil" team has created realistic simulated light curves, to be analyzed blindly by "good" teams. The challenge is open to all interested parties. The initial challenge consists of two steps (TDC0 and TDC1). TDC0 consists of a small number of datasets to be used as a training template. The non-mandatory deadline is December 1 2013. The "good" teams that complete TDC0 will be given access to TDC1. TDC1 consists of thousands of lightcurves, a number sufficient to test precision and accuracy at the subpercent level, necessary for time-delay cosmography. The deadline for responding to TDC1 is July 1 2014. Submissions will be analyzed and compared in terms of predefined metrics to establish the goodness-of-fit, efficiency, precision and accuracy of current algorithms. This poster describes the challenge in detail and gives instructions for participation.

National evaluation of the SafeTrip-21 initiative : final report real time intersection delay.

DOT National Transportation Integrated Search

2010-09-17

Through the U.S. Department of Transportations (USDOT) SafeTrip-21 initiative, the USDOT is testing a variety of : technologies in a number of locations in California as well as along the I-95 corridor on the east coast. As part of this Federal : ...

The model of root graviresponse with retarded arguments

NASA Astrophysics Data System (ADS)

Kondrachuk, Alexander

The graviperception mechanism (GPM) of the roots of higher plants localized in the cap region of a root and supposedly related to statoliths sedimentation produces the signals in response to the change of the root axis orientation relative to the gravity vector G. Meanwhile, the regions (Distal Elongation Zone -DEZ and Central Elongation Zone-CEZ), where the signals initiate the changes of the growth rates of the upper and lower flanks of the root, are located at the significant distances from the cap (thousands microns for some plants). It causes the time delays between the relocation of statoliths in statocytes and the change of the growth rates in elongation zones. It is suggested that the signal targeting the CEZ modulates the initially uniform lateral distribution of some specific substances (S) in the cap region. Then already nonhomogeneous lateral distribution of S is transferred to the CEZ to initiate the change of the growth rates of the opposite flanks. It results in the bending of the root in the line of G and thus in the change of the GPM signal in the cap region. In the present model the kinetics of a root apex bending (angle A) in response to the time (t)-dependent change of the G orientation is described by the integro-differential equation in A(t). The main peculiarity of this model is the presence of retarded (time-delayed) arguments t-TCEZ and t-TDEZ . In this case the solutions of this equation depend on the preceding kinetics of A(t) during the time delays TCEZ and TDEZ . It is suggested that the signals activating the CEZ and DEZ are of different nature. The work is focused on two problems concerning the modeling of the effects of time-delay(s) on the root bending. The first problem supposes the existence of one zone (CEZ) and one time-delay TCEZ . This equation was studied and solved using analytical and numerical methods. We analyzed the model as to whether it can be used to describe the kinetics of root graviresponse in the case of different orientations of the root apex relative to the G vector during the time interval equal to TCEZ (TCEZ > TDEZ ) that precedes the beginning of gravistimultion. Also we explored the conditions of the overshooting (the vertical) and non-overshooting regimes of gravistimulated root bending. Good correlation between the results of the modeling and known experimental data (Barlow et al, 1993, Stochkus, 1994, Mullen, 1998) was found. This allowed us to estimate and analyze the parameters of the model. The second problem supposed the existence of two zones of growth (CEZ and DEZ) and two corresponding time-delays. The effects of the second time-delay connected with the presence of the DEZ on the behavior of the model equation of the root graviresponse kinetics were analyzed and discussed.

Measurement of the Spatial Distribution of Ultracold Cesium Rydberg Atoms by Time-of-Flight Spectroscopy

NASA Astrophysics Data System (ADS)

Li, Jingkui; Zhang, Linjie; Zhang, Hao; Zhao, Jianming; Jia, Suotang

2015-09-01

We prepare nS (n = 49) cesium Rydberg atoms by two-photon excitation in a standard magnetooptical trap to obtain the spatial distribution of the Rydberg atoms by measuring the time-of-flight (TOF) spectra in the case of a low Rydberg density. We analyze the time evolution of the ultracold nS Rydberg atoms distribution by changing the delay time of the pulsed ionization field, defined as the duration from the moment of switching off the excitation lasers to the time of switching on the ionization field. TOF spectra of Rydberg atoms are observed as a function of the delay time and initial Rydberg atomic density. The corresponding full widths at half maximum (FWHMs) are obtained by fitting the spectra with a Gaussian profile. The FWHM decreases with increasing delay time at a relatively high Rydberg atom density (>5 × 107/cm3) because of the decreasing Coulomb interaction between released charges during their flight to the detector. The temperature of the cold atoms is deduced from the dependence of the TOF spectra on the delay time under the condition of low Rydberg atom density.

Reduced Plasminogen Binding and Delayed Activation Render γ′-Fibrin More Resistant to Lysis than γA-Fibrin*

PubMed Central

Kim, Paul Y.; Vu, Trang T.; Leslie, Beverly A.; Stafford, Alan R.; Fredenburgh, James C.; Weitz, Jeffrey I.

2014-01-01

Fibrin (Fn) clots formed from γ′-fibrinogen (γ′-Fg), a variant with an elongated γ-chain, are resistant to lysis when compared with clots formed from the predominant γA-Fg, a finding previously attributed to differences in clot structure due to delayed thrombin-mediated fibrinopeptide (FP) B release or impaired cross-linking by factor XIIIa. We investigated whether slower lysis of γ′-Fn reflects delayed plasminogen (Pg) binding and/or activation by tissue plasminogen activator (tPA), reduced plasmin-mediated proteolysis of γ′-Fn, and/or altered cross-linking. Clots formed from γ′-Fg lysed more slowly than those formed from γA-Fg when lysis was initiated with tPA/Pg when FPA and FPB were both released, but not when lysis was initiated with plasmin, or when only FPA was released. Pg bound to γ′-Fn with an association rate constant 22% lower than that to γA-Fn, and the lag time for initiation of Pg activation by tPA was longer with γ′-Fn than with γA-Fn. Once initiated, however, Pg activation kinetics were similar. Factor XIIIa had similar effects on clots formed from both Fg isoforms. Therefore, slower lysis of γ′-Fn clots reflects delayed FPB release, which results in delayed binding and activation of Pg. When clots were formed from Fg mixtures containing more than 20% γ′-Fg, the upper limit of the normal level, the delay in lysis was magnified. These data suggest that circulating levels of γ′-Fg modulate the susceptibility of clots to lysis by slowing Pg activation by tPA and provide another example of the intimate connections between coagulation and fibrinolysis. PMID:25128532

Successful strategies for improving operating room efficiency at academic institutions.

PubMed

Overdyk, F J; Harvey, S C; Fishman, R L; Shippey, F

1998-04-01

In this prospective study, we evaluated the etiology of operating room (OR) delays in an academic institution, examined the impact of multidisciplinary strategies to improve OR efficiency, and established OR timing benchmarks for use in future OR efficiency studies. OR times and delay etiologies were collected for 94 cases during the initial phase of the study. Timing data and delay etiologies were analyzed, and 2 wk of multidisciplinary OR efficiency awareness education was conducted for the nursing, surgical, and anesthesia staff. After the education period, timing data were collected from 1787 cases, and monthly reports listing individual case delays and timing data were sent to the Chiefs of Service. For the first case of the day, patient in room, anesthesia ready, surgical preparation start, and procedure start time were significantly earlier (P < 0.01) in the posteducation period compared with the preeducation period, and the procedure start time for the first case of the day occurred, on average, 22 min earlier than all other procedures. For all cases combined, turnover time decreased, on average, by 16 min. Unavailability of surgeons, anesthesiologists, and residents decreased significantly (P < 0.05) as causes of OR delays. Anesthesia induction times were consistently longer for the vascular and cardiothoracic services, whereas surgical preparation time was increased for the neurosurgical and orthopedic services (P < 0.05). Identification of the etiology of OR inefficiency, combined with multidisciplinary awareness training and personal accountability, can improve OR efficiency. The time savings realized are probably most cost-effective when combined with more flexible OR staffing and improved OR scheduling. We achieved significant improvements in operating room efficiency by analyzing operating room data on causes of delays, devising strategies for minimizing the most common delays, and subsequently measuring delay data. Personal accountability, streamlining of procedures, interdisciplinary team work, and accurate data collection were all important contributors to improved efficiency.

[Comparison of initial and delayed myocardial imaging with beta-methyl-p-[123I]-iodophenylpentadecanoic acid in acute myocardial infarction].

PubMed

Naruse, H; Yoshimura, N; Yamamoto, J; Morita, M; Fukutake, N; Ohyanagi, M; Iwasaki, T; Fukuchi, M

1994-01-01

Myocardial imaging using beta-methyl-p-[123I]-iodophenylpentadecanoic acid (BMIPP) of 15 patients with acute myocardial infarction was performed to assess "fill-in" and "washout" defects in the delayed myocardial image. The initial and delayed images were evaluated by a visual and quantitative washout rate method. Visual judgement found 8/180 (4%) segments showed "fill-in" defects, and 24/180 segments (13%) showed "washout" defects. There was no relationship between days from onset to the study and the frequency of fill-in and washout defects. The mean washout rate in the segments with "fill-in" defects was 9.0 +/- 16.6%, and that of "washout" defects was 24.9 +/- 18.1% which was significantly higher than in controls (8.7 +/- 15.4%, p < 0.05). There was no correlation between mean washout rate and total blood lipids, total cholesterol, triglyceride and HDL-cholesterol. Therefore, neither time from onset nor blood lipids level was related to changes from the initial image to the delayed image. These changes may be due to relative (false) findings due to changes in circumference, and may be based on myocardial characteristics after myocardial infarction and/or reperfusion.

Ultra-fast movies of thin-film laser ablation

NASA Astrophysics Data System (ADS)

Domke, Matthias; Rapp, Stephan; Schmidt, Michael; Huber, Heinz P.

2012-11-01

Ultra-short-pulse laser irradiation of thin molybdenum films from the glass substrate side initiates an intact Mo disk lift off free from thermal effects. For the investigation of the underlying physical effects, ultra-fast pump-probe microscopy is used to produce stop-motion movies of the single-pulse ablation process, initiated by a 660-fs laser pulse. The ultra-fast dynamics in the femtosecond and picosecond ranges are captured by stroboscopic illumination of the sample with an optically delayed probe pulse of 510-fs duration. The nanosecond and microsecond delay ranges of the probe pulse are covered by an electronically triggered 600-ps laser. Thus, the setup enables an observation of general laser ablation processes from the femtosecond delay range up to the final state. A comparison of time- and space-resolved observations of film and glass substrate side irradiation of a 470-nm molybdenum layer reveals the driving mechanisms of the Mo disk lift off initiated by glass-side irradiation. Observations suggest that a phase explosion generates a liquid-gas mixture in the molybdenum/glass interface about 10 ps after the impact of the pump laser pulse. Then, a shock wave and gas expansion cause the molybdenum layer to bulge, while the enclosed liquid-gas mixture cools and condenses at delay times in the 100-ps range. The bulging continues for approximately 20 ns, when an intact Mo disk shears and lifts off at a velocity of above 70 m/s. As a result, the remaining hole is free from thermal effects.

Efficacy of Error for the Correction of Initially Incorrect Assumptions and of Feedback for the Affirmation of Correct Responding: Learning in the Classroom

ERIC Educational Resources Information Center

Brosvic, Gary M.; Epstein, Michael L.; Cook, Michael J.; Dihoff, Roberta E.

2005-01-01

Participants completed 5 classroom examinations during which the timing of knowledge of results (no feedback: Scantron form; delayed feedback: end-of-test, 24 hour delay; immediate feedback: educator, response form) and iterative responding (1 response, up to 4 responses) were manipulated. At the end of the semester, each participant completed a…

Delay activity of saccade-related neurons in the caudal dentate nucleus of the macaque cerebellum

PubMed Central

Sommer, Marc A.

2013-01-01

The caudal dentate nucleus (DN) in lateral cerebellum is connected with two visual/oculomotor areas of the cerebrum: the frontal eye field and lateral intraparietal cortex. Many neurons in frontal eye field and lateral intraparietal cortex produce “delay activity” between stimulus and response that correlates with processes such as motor planning. Our hypothesis was that caudal DN neurons would have prominent delay activity as well. From lesion studies, we predicted that this activity would be related to self-timing, i.e., the triggering of saccades based on the internal monitoring of time. We recorded from neurons in the caudal DN of monkeys (Macaca mulatta) that made delayed saccades with or without a self-timing requirement. Most (84%) of the caudal DN neurons had delay activity. These neurons conveyed at least three types of information. First, their activity was often correlated, trial by trial, with saccade initiation. Correlations were found more frequently in a task that required self-timing of saccades (53% of neurons) than in a task that did not (27% of neurons). Second, the delay activity was often tuned for saccade direction (in 65% of neurons). This tuning emerged continuously during a trial. Third, the time course of delay activity associated with self-timed saccades differed significantly from that associated with visually guided saccades (in 71% of neurons). A minority of neurons had sensory-related activity. None had presaccadic bursts, in contrast to DN neurons recorded more rostrally. We conclude that caudal DN neurons convey saccade-related delay activity that may contribute to the motor preparation of when and where to move. PMID:23365182

Synchronous termination of replication of the two chromosomes is an evolutionary selected feature in Vibrionaceae

PubMed Central

Kemter, Franziska S.; Messerschmidt, Sonja J.; Schallopp, Nadine; Sobetzko, Patrick; Bunk, Boyke; Spröer, Cathrin; Teschler, Jennifer K.; Yildiz, Fitnat H.

2018-01-01

Vibrio cholerae, the causative agent of the cholera disease, is commonly used as a model organism for the study of bacteria with multipartite genomes. Its two chromosomes of different sizes initiate their DNA replication at distinct time points in the cell cycle and terminate in synchrony. In this study, the time-delayed start of Chr2 was verified in a synchronized cell population. This replication pattern suggests two possible regulation mechanisms for other Vibrio species with different sized secondary chromosomes: Either all Chr2 start DNA replication with a fixed delay after Chr1 initiation, or the timepoint at which Chr2 initiates varies such that termination of chromosomal replication occurs in synchrony. We investigated these two models and revealed that the two chromosomes of various Vibrionaceae species terminate in synchrony while Chr2-initiation timing relative to Chr1 is variable. Moreover, the sequence and function of the Chr2-triggering crtS site recently discovered in V. cholerae were found to be conserved, explaining the observed timing mechanism. Our results suggest that it is beneficial for bacterial cells with multiple chromosomes to synchronize their replication termination, potentially to optimize chromosome related processes as dimer resolution or segregation. PMID:29505558

A NMDA Receptor Antagonist, MK-801 Impairs Consolidating Extinction of Auditory Conditioned Fear Responses in a Pavlovian Model

PubMed Central

Wang, Zheng-Hong; Rao, Zhi-Ren; Wu, Sheng-Xi; Li, Yun-Qing; Wang, Wen

2009-01-01

Background In auditory fear conditioning, repeated presentation of the tone in the absence of shock leads to extinction of the acquired fear responses. The glutamate N-methyl-D-aspartate receptor (NMDAR) is thought to be involved in the extinction of the conditioned fear responses, but its detailed role in initiating and consolidating or maintaining the fear extinction memory is unclear. Here we investigated this issue by using a NMDAR antagonist, MK-801. Methods/Main Findings The effects of immediate (beginning at 10 min after the conditioning) and delayed (beginning at 24 h after conditioning) extinctions were first compared with the finding that delayed extinction caused a better and long-lasting (still significant on the 20th day after extinction) depression on the conditioned fear responses. In a second experiment, MK-801 was intraperitoneally (i.p.) injected at 40 min before, 4 h or 12 h after the delayed extinction, corresponding to critical time points for initiating, consolidating or maintaining the fear extinction memory. i.p. injection of MK-801 at either 40 min before or 4 h after delayed extinction resulted in an impairment of initiating and consolidating fear extinction memory, which caused a long lasting increased freezing score that was still significant on the 7th day after extinction, compared with extinction group. However, MK-801 administered at 12 h after the delayed extinction, when robust consolidation has been occurred and stabilized, did not affect the established extinction memory. Furthermore, the changed freezing behaviors was not due to an alteration in general anxiety levels, since MK-801 treatment had no effect on the percentage of open-arm time or open-arm entries in an Elevated Plus Maze (EPM) task. Conclusions/Significance Our data suggested that the activation of NMDARs plays important role in initiation and consolidation but not maintenance of fear extinction memory. Together with the fact that NMDA receptor is very important for memory, our data added experimental evidence to the concept that the extinction of conditioned fear responses is a procedure of initiating and consolidating new memory other than simply “erasing” the fear memory. PMID:19855841

A NMDA receptor antagonist, MK-801 impairs consolidating extinction of auditory conditioned fear responses in a Pavlovian model.

PubMed

Liu, Jun-Li; Li, Min; Dang, Xiao-Rong; Wang, Zheng-Hong; Rao, Zhi-Ren; Wu, Sheng-Xi; Li, Yun-Qing; Wang, Wen

2009-10-26

In auditory fear conditioning, repeated presentation of the tone in the absence of shock leads to extinction of the acquired fear responses. The glutamate N-methyl-D-aspartate receptor (NMDAR) is thought to be involved in the extinction of the conditioned fear responses, but its detailed role in initiating and consolidating or maintaining the fear extinction memory is unclear. Here we investigated this issue by using a NMDAR antagonist, MK-801. The effects of immediate (beginning at 10 min after the conditioning) and delayed (beginning at 24 h after conditioning) extinctions were first compared with the finding that delayed extinction caused a better and long-lasting (still significant on the 20(th) day after extinction) depression on the conditioned fear responses. In a second experiment, MK-801 was intraperitoneally (i.p.) injected at 40 min before, 4 h or 12 h after the delayed extinction, corresponding to critical time points for initiating, consolidating or maintaining the fear extinction memory. i.p. injection of MK-801 at either 40 min before or 4 h after delayed extinction resulted in an impairment of initiating and consolidating fear extinction memory, which caused a long lasting increased freezing score that was still significant on the 7th day after extinction, compared with extinction group. However, MK-801 administered at 12 h after the delayed extinction, when robust consolidation has been occurred and stabilized, did not affect the established extinction memory. Furthermore, the changed freezing behaviors was not due to an alteration in general anxiety levels, since MK-801 treatment had no effect on the percentage of open-arm time or open-arm entries in an Elevated Plus Maze (EPM) task. Our data suggested that the activation of NMDARs plays important role in initiation and consolidation but not maintenance of fear extinction memory. Together with the fact that NMDA receptor is very important for memory, our data added experimental evidence to the concept that the extinction of conditioned fear responses is a procedure of initiating and consolidating new memory other than simply "erasing" the fear memory.

The recommendation of line-balancing improvement on MCM product line 1 using genetics algorithm and moodie young at XYZ Company, Co.

NASA Astrophysics Data System (ADS)

Sriwana, I. K.; Marie, I. A.; Mangala, D.

2017-12-01

Kencana Gemilang, Co. is one electronics industry engaging in the manufacture sector. This company manufactures and assembles household electronic products, such as rice cooker, fan, iron, blender, etc. The company deals with an issue of underachievement of an established production target on MCM products line 1. This study aimed to calculate line efficiencies, delay times, and initial line smoothness indexes. The research was carried out by means of depicting a precedence diagram and gathering time data of each work element followed by examination and calculation of standard time as well as line balancing using methods of Moodie Young and Generics Algorithm. Based on results of calculation, better line balancing than the existing initial conditions, i.e. improvement in the line efficiency by 18.39%, deterioration in balanced delay by 28.39%, and deterioration of a smoothness index by 23.85% was obtained.

How long do the short-term violent video game effects last?

PubMed

Barlett, Christopher; Branch, Omar; Rodeheffer, Christopher; Harris, Richard

2009-01-01

How long do the effects of the initial short-term increase in aggression and physiological arousal last after violent video game play? Study 1 (N=91) had participants complete pre- and postvideo game measures of aggressive thoughts, aggressive feelings, and heart rate. Then, participants completed Time 3 measures after 4 min or 9 min of delay. Study 2 employed a similar procedure, but had participants (N=91) complete the hot sauce paradigm to assess aggressive behavior after a 0, 5, or 10 min delay. First, results indicated that aggressive feelings, aggressive thoughts, aggressive behavior, and heart rate initially increased after violent video game play. Second, results of the delay condition revealed that the increase in aggressive feelings and aggressive thoughts lasted less than 4 min, whereas heart rate and aggressive behavior lasted 4-9 min. Copyright 2009 Wiley-Liss, Inc.

Lessons Learned From a Pilot RCT of Simultaneous Versus Delayed Initiation of Continuous Glucose Monitoring in Children and Adolescents With Type 1 Diabetes Starting Insulin Pump Therapy

PubMed Central

Olivier, Patricia; Huot, Celine; Richardson, Christine; Nakhla, Meranda; Romain, Judette

2014-01-01

Uncertainty remains about effectiveness of continuous glucose monitoring (CGM) in pediatric type 1 diabetes (T1D). Success with CGM is related to CGM adherence, which may relate to readiness to make the behavior changes required for effective use. We hypothesize that readiness for change will be greater at initiation of insulin pump therapy than in established pump users, and that this will predict CGM adherence. Our objective was to evaluate the feasibility of a randomized controlled trial (RCT) in children with established T1D comparing simultaneous pump and CGM initiation to standard pump therapy with delayed CGM initiation. We randomized participants to simultaneous pump and CGM initiation or to standard pump therapy with the option of adding CGM 4 months later. CGM adherence was tracked via web-based download and readiness for change assessed with the SOCRATES questionnaire. Of 41 eligible children, 20 agreed to participate; 15 subjects completed the study (7 males; baseline age 11.8 ± 4.0 years; T1D duration 2.7 ± 2.7 years; mean A1C 8.2 ± 0.8%). Six of 8 simultaneous group subjects used CGM > 60% of the time for 4 months compared to 1 of 7 delayed group subjects (P = .02). Using SOCRATES, we could assign 87-100% of subjects to a single motivation stage at baseline and 4 months. This pilot study demonstrates the feasibility of randomizing pump naïve children and adolescents with established T1D to simultaneous pump and CGM initiation versus standard pump therapy with delayed CGM initiation. Lessons from this pilot study were used to inform development of a full-scale multicenter RCT. PMID:24876616

Fault detection for singular switched linear systems with multiple time-varying delay in finite frequency domain

NASA Astrophysics Data System (ADS)

Zhai, Ding; Lu, Anyang; Li, Jinghao; Zhang, Qingling

2016-10-01

This paper deals with the problem of the fault detection (FD) for continuous-time singular switched linear systems with multiple time-varying delay. In this paper, the actuator fault is considered. Besides, the systems faults and unknown disturbances are assumed in known frequency domains. Some finite frequency performance indices are initially introduced to design the switched FD filters which ensure that the filtering augmented systems under switching signal with average dwell time are exponentially admissible and guarantee the fault input sensitivity and disturbance robustness. By developing generalised Kalman-Yakubovic-Popov lemma and using Parseval's theorem and Fourier transform, finite frequency delay-dependent sufficient conditions for the existence of such a filter which can guarantee the finite-frequency H- and H∞ performance are derived and formulated in terms of linear matrix inequalities. Four examples are provided to illustrate the effectiveness of the proposed finite frequency method.

Evaluation of a randomized intervention to delay sexual initiation among fifth-graders followed through the sixth grade

PubMed Central

Koo, Helen P.; Rose, Allison; El-Khorazaty, M. Nabil; Yao, Qing; Jenkins, Renee R.; Anderson, Karen M.; Davis, Maurice; Walker, Leslie R.

2011-01-01

US adolescents initiate sex at increasingly younger ages, yet few pregnancy prevention interventions for children as young as 10–12 years old have been evaluated. Sixteen Washington, DC schools were randomly assigned to intervention versus control conditions. Beginning in 2001/02 with fifth-grade students and continuing during the sixth grade, students completed pre-intervention and post-intervention surveys each school year. Each year, the intervention included 10–13 classroom sessions related to delaying sexual initiation. Linear hierarchical models compared outcome changes between intervention and control groups by gender over time. Results show the intervention significantly decreased a rise over time in the anticipation of having sex in the next 12 months among intervention boys versus control boys, but it had no other outcome effects. Among girls, the intervention had no significant outcome effects. One exception is that for both genders, compared with control students, intervention students increased their pubertal knowledge. In conclusion, a school-based curriculum to delay sexual involvement among fifth-grade and sixth-grade high-risk youths had limited impact. Additional research is necessary to outline effective interventions, and more intensive, comprehensive interventions may be required to counteract adverse circumstances in students’ lives and pervasive influences toward early sex. ClinicalTrials. gov identifier: NCT00341471 PMID:21857793

National Airspace System Delay Estimation Using Weather Weighted Traffic Counts

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.; Sridhar, Banavar

2004-01-01

Assessment of National Airspace System performance, which is usually measured in terms of delays resulting from the application of traffic flow management initiatives in response to weather conditions, volume, equipment outages and runway conditions, is needed both for guiding flow control decisions during the day of operations and for post operations analysis. Comparison of the actual delay, resulting from the traffic flow management initiatives, with the expected delay, based on traffic demand and other conditions, provides the assessment of the National Airspace System performance. This paper provides a method for estimating delay using the expected traffic demand and weather. In order to identify the cause of delays, 517 days of National Airspace System delay data reported by the Federal Aviation Administration s Operations Network were analyzed. This analysis shows that weather is the most important causal factor for delays followed by equipment and runway delays. Guided by these results, the concept of weather weighted traffic counts as a measure of system delay is described. Examples are given to show the variation of these counts as a function of time of the day. The various datasets, consisting of aircraft position data, enroute severe weather data, surface wind speed and visibility data, reported delay data and number of aircraft handled by the Centers data, and their sources are described. The procedure for selecting reference days on which traffic was minimally impacted by weather is described. Different traffic demand on each reference day of the week, determined by analysis of 42 days of traffic and delay data, was used as the expected traffic demand for each day of the week. Next, the method for computing the weather weighted traffic counts using the expected traffic demand, derived from reference days, and the expanded regions around severe weather cells is discussed. It is shown via a numerical example that this approach improves the dynamic range of the weather weighted traffic counts considerably. Time histories of these new weather weighted traffic counts are used for synthesizing two statistical features, six histogram features and six time domain features. In addition to these enroute weather features, two surface weather features of number of major airports in the United States with high mean winds and low mean visibility are also described. A least squares procedure for establishing a functional relation between the features, using combinations of these features, and system delays is explored using 36 days of data. Best correlations between the estimated delays using the functional relation and the actual delays provided by the Operations Network are obtained with two different combinations of features: 1) six time domain features of weather weighted traffic counts plus two surface weather features, and 2) six histogram features and mean of weather weighted traffic counts along with the two surface weather features. Correlation coefficient values of 0.73 and 0.83 were found in these two instances.

Improving operating room first start efficiency - value of both checklist and a pre-operative facilitator.

PubMed

Panni, M K; Shah, S J; Chavarro, C; Rawl, M; Wojnarwsky, P K; Panni, J K

2013-10-01

There are multiple components leading to improved operating room efficiency. We undertook a project focusing on first case starts; accounting for each delay component on a global basis. Our hypothesis was there would be a reduction in first start delays after we implemented strategies to address the issues identified through this accounting process. An orange sheet checklist was implemented, with specific items that needed to be clear prior to roll back to the operating room (OR), and an OR facilitator was employed to intervene whenever there were any missing items needed for a specific patient. We present the data from this quality improvement project over an 18-month period. Initially, 10.07 (± 0.73) delayed first starts occurred per day but declined steadily over time to a low of 4.95 (± 0.38) per day after 6 months (-49.2 %, P < 0.001). By the end of the project, the most common reasons for delay still included late surgical attending (19%), schedule changes (14%) as well as 'other reasons' (13%), but with an overall reduction per day of each. Total anaesthesia delay initially totalled 11% of the first start delays, but was negligible (< 1%) at the project's completion. While we have a challenging operating room environment based on our patient population, multiple trainees in both the surgery and anaesthesiology teams: an orange sheet - pre-operative checklist in addition to a dedicated pre-operative facilitator; allowed us to make a substantial improvement in our first start on time starts. © 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

The giant acoustic atom - a single quantum system with a deterministic time delay

NASA Astrophysics Data System (ADS)

Guo, Lingzhen; Grimsmo, Arne; Frisk Kockum, Anton; Pletyukhov, Mikhail; Johansson, Göran

2017-04-01

We investigate the quantum dynamics of a single transmon qubit coupled to surface acoustic waves (SAWs) via two distant connection points. Since the acoustic speed is five orders of magnitude slower than the speed of light, the travelling time between the two connection points needs to be taken into account. Therefore, we treat the transmon qubit as a giant atom with a deterministic time delay. We find that the spontaneous emission of the system, formed by the giant atom and the SAWs between its connection points, initially follows a polynomial decay law instead of an exponential one, as would be the case for a small atom. We obtain exact analytical results for the scattering properties of the giant atom up to two-phonon processes by using a diagrammatic approach. The time delay gives rise to novel features in the reflection, transmission, power spectra, and second-order correlation functions of the system. Furthermore, we find the short-time dynamics of the giant atom for arbitrary drive strength by a numerically exact method for open quantum systems with a finite-time-delay feedback loop. L. G. acknowledges financial support from Carl-Zeiss Stiftung (0563-2.8/508/2).

Comparing Methods for Dynamic Airspace Configuration

NASA Technical Reports Server (NTRS)

Zelinski, Shannon; Lai, Chok Fung

2011-01-01

This paper compares airspace design solutions for dynamically reconfiguring airspace in response to nominal daily traffic volume fluctuation. Airspace designs from seven algorithmic methods and a representation of current day operations in Kansas City Center were simulated with two times today's demand traffic. A three-configuration scenario was used to represent current day operations. Algorithms used projected unimpeded flight tracks to design initial 24-hour plans to switch between three configurations at predetermined reconfiguration times. At each reconfiguration time, algorithms used updated projected flight tracks to update the subsequent planned configurations. Compared to the baseline, most airspace design methods reduced delay and increased reconfiguration complexity, with similar traffic pattern complexity results. Design updates enabled several methods to as much as half the delay from their original designs. Freeform design methods reduced delay and increased reconfiguration complexity the most.

New approach to enhance and evaluate the performance of vehicle-infrastructure integration and its communication systems, final report.

DOT National Transportation Integrated Search

2010-09-01

Initial research studied the use of wireless local area networks (WLAN) protocols in Inter-Vehicle Communications : (IVC) environments. The protocols performance was evaluated in terms of measuring throughput, jitter time and : delay time. This re...

Extreme-ultraviolet-initiated high-order harmonic generation in Ar+

NASA Astrophysics Data System (ADS)

Clarke, D. D. A.; van der Hart, H. W.; Brown, A. C.

2018-02-01

We employ the R matrix with time dependence method to investigate extreme-ultraviolet-initiated high-order harmonic generation (XIHHG) in Ar+. Using a combination of extreme-ultraviolet (XUV, 92 nm, 3 ×1012W cm-2 ) and time-delayed, infrared (IR, 800 nm, 3 ×1014W cm-2 ) laser pulses, we demonstrate that control over both the mechanism and timing of ionization can afford significant enhancements in the yield of plateau and subthreshold harmonics alike. The presence of the XUV pulse is also shown to alter the relative contribution of different electron emission pathways. Manifestation of the Ar+ electronic structure is found in the appearance of a pronounced Cooper minimum. Interferences among the outer-valence 3 p and inner-valence 3 s electrons are found to incur only a minor suppression of the harmonic intensities, at least for the present combination of XUV and IR laser light. Additionally, the dependence of the XIHHG efficiency on time delay is discussed and rationalized with the aid of classical trajectory simulations.

[Impact of care pathway on the delay for initiation of antituberculosis treatment in Conakry, Guinea].

PubMed

Camara, A; Bah-Sow, O Y; Baldé, N M; Camara, L M; Barry, I S; Bah, B; Diallo, M; Chaperon, J; Riou, F

2009-06-01

Complex care pathways can result in detrimental treatment delay particularly in tuberculosis patients. The purpose of this retrospective study was to assess the care pathways followed by tuberculosis patients prior to diagnosis and to assess impact on the delay for initiation of treatment in Conakry, Guinea. A total of 112 patients were interviewed at the time of first admission for pulmonary tuberculosis with positive bacilloscopy. Based on interview data, pathways were classified as conventional (use of health care facilities only) and mixed (use of health care facilities, self-medication, and traditional medicine). The correlation between patient characteristics and type of pathway was assessed by univariate and multivariate analysis and the two groups, i.e., conventional vs. mixed, were compared with regard to delay for initiation of treatment. The care pathway was classified as mixed in two out of three patients. Multivariate analysis showed that this type of pathway was only correlated with schooling (p=0.02). The mean delay for treatment was similar, i.e., 13.4 and 12.8 weeks for conventional and mixed pathways respectively (p<0.68). The percentage of pathways including three consultations at health care facilities was significantly higher in the conventional than mixed group (72% vs. 30%, p<0.001). The main reasons given for delayed use of health care facilities were poor knowledge of tuberculosis symptoms (26%) and high cost of care (12%). The findings of this study indicate that tuberculosis patients follow a variety of care pathways that can lead to delayed treatment. An information campaign is needed to increase awareness among the population and care providers.

Short-Term Anticoagulant Therapy and Thrombus Location Are Independent Risk Factors for Delayed Recanalization of Deep Vein Thrombosis.

PubMed

Zhang, Chuanlin; Fu, Qining; Zhao, Yu; Mu, Shaoyu; Liu, Liping

2016-01-21

Prompt recanalization of the vein containing the thrombus is an important goal during the initial treatment of DVT, and risk factors for delayed recanalization in patients with deep vein thrombosis (DVT) in the lower extremities need to be determined. A total of 174 patients with DVT in lower extremities were recruited from June 2014 to March 2015 at our hospital. Duplex ultrasound scanning was conducted for all patients at 1 and 6 months after baseline evaluation. We divided the patients into recanalization and non-recanalization groups and analyzed risk factors for delayed recanalization. The univariate analysis revealed that an oral anticoagulant time of less than 3 months and venous thrombus location were risk factors for delayed recanalization (P<0.01). However, age, gender, hypertension, diabetes, pulmonary embolism, incidence factors, the use of catheter-directed thrombolytic (CDT) drugs, and inferior vena cava filter (IVCF) implantation had no influence on the incidence of delayed recanalization in patients with DVT (P>0.05). The multivariate analysis showed that patients with an anticoagulant time of less than 3 months had a lower incidence of recanalization than those with an anticoagulant time of more than 3 months (OR=2.358, P<0.05). The risk of delayed recanalization in patients with proximal DVT was 7 times higher than that in patients with distal DVT. Duration of anticoagulant treatment of less than 3 months and venous thrombus location are independent risk factors for delayed recanalization of DVT in the lower extremities.

Maternal deaths in eastern Indonesia: 20 years and still walking: an ethnographic study

PubMed Central

2014-01-01

Background The delays in receiving adequate emergency maternal care described by Thaddeus and Maine twenty years ago are still occurring, as exemplified in this study of cases of maternal deaths in a subdistrict in rural eastern Indonesia. Methods An ethnographic design was conducted, recruiting eleven families who reported on cases of maternal deaths in one sub-district of Indonesia, as well as assessing the geographical and cultural context of the villages. Traditional birth attendants and village leaders provided information to the research team which was thematically and contextually analysed. Results Two stages to the first and second delays have been differentiated in this study. First, delays in the decision to seek care comprised time taken to recognise (if at all) that an emergency situation existed, followed by time taken to reach a decision to request care. The decision to request care resided variously with the family or cadre. Second, delays in reaching care comprised time taken to deliver the request for help and then time for help to arrive. A phone was not available to request care in many cases and so the request was delivered by walking or motorbike. In two cases where the decision to seek care and the delivery of the request happened in a timely way, help was delayed because the midwife and ambulance respectively were unavailable. Conclusions This study, although a small sample, confirmed that either a single delay or a sequence of delays can prove fatal. Delays were determined by both social and geographic factors, any of which alone could be limiting. Initiatives to improve maternal health outcomes need to address multiple factors: increased awareness of equitable access to maternal health care, village preparedness for emergency response, improved access to telecommunications and geographic access. PMID:24447873

Signals, resistance to change, and conditioned reinforcement in a multiple schedule.

PubMed

Bell, Matthew C; Gomez, Belen E; Kessler, Kira

2008-06-01

The effect of signals on resistance to change was evaluated using pigeons responding on a three-component multiple schedule. Each component contained a variable-interval initial link followed by a fixed-time terminal link. One component was an unsignaled-delay schedule, and two were equivalent signaled-delay schedules. After baseline training, resistance to change was assessed through (a) extinction and (b) adding free food to the intercomponent interval. During these tests, the signal stimulus from one of the signaled-delay components (SIG-T) was replaced with the initial-link stimulus from that component, converting it to an unsignaled-delay schedule. That signal stimulus was added to the delay period of the unsignaled-delay component (UNS), converting it to a signaled-delay schedule. The remaining signaled component remained unchanged (SIG-C). Resistance-to-change tests showed removing the signal had a minimal effect on resistance to change in the SIG-T component compared to the unchanged SIG-C component except for one block during free-food testing. Adding the signal to the UNS component significantly increased response rates suggesting that component had low response strength. Interestingly, the direction of the effect was in the opposite direction from what is typically observed. Results are consistent with the conclusion that the signal functioned as a conditioned reinforcer and inconsistent with a generalization-decrement explanation.

Simulations of the Richtmyer-Meshkov Instability in a two-shock vertical shock tube

NASA Astrophysics Data System (ADS)

Ferguson, Kevin; Olson, Britton; Jacobs, Jeffrey

2017-11-01

Simulations of the Richtmyer-Meshkov Instability (RMI) in a new two-shock vertical shock tube configuration are presented. The simulations are performed using the ARES code at Lawrence-Livermore National Laboratory (LLNL). Two M=1.2 shock waves travel in opposing directions and impact an initially stationary interface formed by sulfur hexaflouride (SF6) and air. The delay between the two shocks is controlled to achieve a prescribed temporal separation in shock wave arrival time. Initial interface perturbations and diffusion profiles are generated in keeping with previously gathered experimental data. The effect of varying the inter-shock delay and initial perturbation structure on instability growth and mixing parameters is examined. Information on the design, construction, and testing of a new two-shock vertical shock tube are also presented.

The research on delayed fracture behavior of high-strength bolts in steel structure

NASA Astrophysics Data System (ADS)

Li, Guo dong; Li, Nan

2017-07-01

High-strength bolts have been widely used in power plants. However, the high-strength bolts which being employed in pumping station, steel structure and pipeline anti-whip structure have been found delayed fracture for many times in a power plant, this will affect the reliability of steel fracture and bring blow risk caused by falling objects. The high-strength bolt with delayed fracture was carried out fracture analysis, metallurgical analysis, chemical analysis, mechanical analysis, as well as bolts installation analysis, it can be comprehensively confirmed that the direct cause of high-strength bolts delayed fracture is the stress corrosion, and the root cause of high-strength bolts delayed fracture should be the improper installation at the initial and the imperfect routine anti-corrosion maintenance.

Can exercise ameliorate treatment toxicity during the initial phase of testosterone deprivation in prostate cancer patients? Is this more effective than delayed rehabilitation?

PubMed Central

2012-01-01

Background There has been substantial increase in use of androgen deprivation therapy as adjuvant management of prostate cancer. However, this leads to a range of musculoskeletal toxicities including reduced bone mass and increased skeletal fractures compounded with rapid metabolic alterations, including increased body fat, reduced lean mass, insulin resistance and negative lipoprotein profile, increased incidence of cardiovascular and metabolic morbidity, greater distress and reduced quality of life. Numerous research studies have demonstrated certain exercise prescriptions to be effective at preventing or even reversing these treatment toxicities. However, all interventions to date have been of rehabilitative intent being implemented after a minimum of 3 months since initiation of androgen deprivation, by which time considerable physical and psychological health problems have manifested. The pressing question is whether it is more efficacious to commence exercise therapy at the same time as initiating androgen deprivation, so treatment induced adverse effects can be immediately attenuated or indeed prevented. Methods/design We are proposing a multi-site randomized controlled trial with partial crossover to examine the effects of timing of exercise implementation (immediate or delayed) on preserving long-term skeletal health, reversing short- and long-term metabolic and cardiovascular risk factors, and supporting mental health in men receiving androgen deprivation therapy. 124 men who are about to initiate androgen deprivation for prostate cancer will be randomized to immediate or delayed groups. Immediate will commence a 6-month exercise program within 7–10 days of their first dose. Delayed will receive usual care for 6 months and then commence the exercise program for 6 months (partial cross-over). Immediate will be free to adopt the lifestyle of their choosing following the initial 6-month intervention. Measurements for primary and secondary endpoints will take place at baseline, 6 months and 12 months. Discussion This project is unique as it explores a fundamental question of when exercise implementation will be of most benefit and addresses both physical and psychological consequences of androgen deprivation initiation. The final outcome may be adjunct treatment which will reduce if not prevent the toxicities of androgen deprivation, ultimately resulting in reduced morbidity and mortality for men with prostate cancer. Trial registration ACTRN12612000097842 PMID:23013489

A kinematic analysis of the rapid step test in balance-impaired and unimpaired older women.

PubMed

Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

2007-04-01

Little is known about the kinematic and kinetic determinants that might explain age and balance-impairment alterations in the results of volitional stepping performance tests. Maximal unipedal stance time (UST) was used to distinguish "balance-impaired" old (BI, UST<10s, N=15, mean age=76 years) from unimpaired old (O, UST>30s, N=12, mean age=71 years) before they and healthy young females (Y, UST>30s, N=13, mean age=23 years) performed the rapid step test (RST). The RST evaluates the time required to take volitional front, side, and back steps of at least 80% maximum step length in response to verbal commands. Kinematic and kinetic data were recorded during the RST. The results indicate that the initiation phase of the step was the major source of age- and balance impairment-related delays. The delays in BI were primarily caused by increased postural adjustments prior to step initiation, as measured by center-of-pressure (COP) path length (p<0.003). The Step landing phase showed similar, but non-significant, temporal trends. Step length and peak center-of-mass (COM) deceleration during the Step-Out landing decreased in O by 18% (p=0.0002) and 24% (p=0.001), respectively, and a further 12% (p=0.04) and 18% (p=0.08) in BI. We conclude that the delay in BI step initiation was due to the increase in their postural adjustments prior to step initiation.

Measurements of copper ground-state and metastable level population densities in a copper-chloride laser

NASA Technical Reports Server (NTRS)

Nerheim, N. M.

1977-01-01

The population densities of both the ground and the 2D(5/2) metastable states of copper atoms in a double-pulsed copper-chloride laser are correlated with laser energy as a function of time after the dissociation current pulse. Time-resolved density variations of the ground and excited copper atoms were derived from measurements of optical absorption at 324.7 and 510.6 nm, respectively, over a wide range of operating conditions in laser tubes with diameters of 4 to 40 mm. The minimum delay between the two current pulses at which lasing was observed is shown to be a function of the initial density and subsequent decay of the metastable state. Similarly, the maximum delay is shown to be a function of the initial density and decay of the ground state.

Teaching self-control with qualitatively different reinforcers.

PubMed

Passage, Michael; Tincani, Matt; Hantula, Donald A

2012-01-01

This study examined the effectiveness of using qualitatively different reinforcers to teach self-control to an adolescent boy who had been diagnosed with an intellectual disability. First, he was instructed to engage in an activity without programmed reinforcement. Next, he was instructed to engage in the activity under a two-choice fixed-duration schedule of reinforcement. Finally, he was exposed to self-control training, during which the delay to a more preferred reinforcer was initially short and then increased incrementally relative to the delay to a less preferred reinforcer. Self-control training effectively increased time on task to earn the delayed reinforcer.

Real Time Metrics and Analysis of Integrated Arrival, Departure, and Surface Operations

NASA Technical Reports Server (NTRS)

Sharma, Shivanjli; Fergus, John

2017-01-01

To address the Integrated Arrival, Departure, and Surface (IADS) challenge, NASA is developing and demonstrating trajectory-based departure automation under a collaborative effort with the FAA and industry known Airspace Technology Demonstration 2 (ATD-2). ATD-2 builds upon and integrates previous NASA research capabilities that include the Spot and Runway Departure Advisor (SARDA), the Precision Departure Release Capability (PDRC), and the Terminal Sequencing and Spacing (TSAS) capability. As trajectory-based departure scheduling and collaborative decision making tools are introduced in order to reduce delays and uncertainties in taxi and climb operations across the National Airspace System, users of the tools across a number of roles benefit from a real time system that enables common situational awareness. A real time dashboard was developed to inform and present users notifications and integrated information regarding airport surface operations. The dashboard is a supplement to capabilities and tools that incorporate arrival, departure, and surface air-traffic operations concepts in a NextGen environment. In addition to shared situational awareness, the dashboard offers the ability to compute real time metrics and analysis to inform users about capacity, predictability, and efficiency of the system as a whole. This paper describes the architecture of the real time dashboard as well as an initial proposed set of metrics. The potential impact of the real time dashboard is studied at the site identified for initial deployment and demonstration in 2017: Charlotte-Douglas International Airport (CLT). The architecture of implementing such a tool as well as potential uses are presented for operations at CLT. Metrics computed in real time illustrate the opportunity to provide common situational awareness and inform users of system delay, throughput, taxi time, and airport capacity. In addition, common awareness of delays and the impact of takeoff and departure restrictions stemming from traffic flow management initiatives are explored. The potential of the real time tool to inform users of the predictability and efficiency of using a trajectory-based departure scheduling system is also discussed.

Shallow processing of ambiguous pronouns: evidence for delay.

PubMed

Stewart, Andrew J; Holler, Judith; Kidd, Evan

2007-12-01

Two self-paced reading-time experiments examined how ambiguous pronouns are interpreted under conditions that encourage shallow processing. In Experiment 1 we show that sentences containing ambiguous pronouns are processed at the same speed as those containing unambiguous pronouns under shallow processing, but more slowly under deep processing. We outline three possible models to account for the shallow processing of ambiguous pronouns. Two involve an initial commitment followed by possible revision, and the other involves a delay in interpretation. In Experiment 2 we provide evidence that supports the delayed model of ambiguous pronoun resolution under shallow processing. We found no evidence to support a processing system that makes an initial commitment to an interpretation of the pronoun when it is encountered. We extend the account of pronoun resolution proposed by Rigalleau, Caplan, and Baudiffier (2004) to include the treatment of ambiguous pronouns under shallow processing.

Delayed initiation but not gradual advancement of enteral formula feeding reduces the incidence of necrotizing enterocolitis (NEC) in preterm pigs

USDA-ARS?s Scientific Manuscript database

Enteral formula feeding is a risk factor for necrotizing enterocolitis (NEC) in premature infants, yet studies are conflicting regarding the safest timing for introduction and advancement of feeds. Our aim was to test the effects of early vs. late initiation and abrupt vs. gradual advancement of ent...

Military Training Time and Cost Should Be Reduced Through Improved Management.

ERIC Educational Resources Information Center

General Accounting Office, Washington, DC.

The report on the management of recruit and initial skill training identifies delays in training cycles, their causes, and resultant costs. In visits to four recruit training centers, eight initial skill training schools, and various headquarters offices, the General Accounting Office (GAO) identified 1,979,000 man-days per year that new members…

Postplacental or delayed levonorgestrel intrauterine device insertion and breastfeeding duration

PubMed Central

Chen, Beatrice A.; Reeves, Matthew F.; Creinin, Mitchell D.; Schwarz, E. Bimla

2011-01-01

BACKGROUND The objective was to assess the effect of timing of postpartum levonorgestrel-releasing IUD insertion on breastfeeding continuation. STUDY DESIGN Women interested in using a levonorgestrel IUD postpartum were randomized to immediate postplacental insertion (postplacental group) or insertion 6–8 weeks after vaginal delivery (delayed group). Duration and exclusivity of breastfeeding were assessed at 6–8 weeks, 3 months, and 6 months postpartum. Only women who received an IUD were included in this analysis. RESULTS Breastfeeding was initiated by 32/50 (64%) of women receiving a postplacental IUD and 27/46 (58.7%) of women receiving a delayed IUD (p=0.59). More women in the delayed group compared to the postplacental group continued to breastfeed at 6–8 weeks (16/46 vs 15/50, p=0.62), 3 months (13/46 vs 7/50, p=0.13), and 6 months postpartum (11/46 vs 3/50, p=0.02). The results did not differ when only women who initiated breastfeeding or only primiparous women with no prior breastfeeding experience were analyzed. CONCLUSIONS Immediate postplacental insertion of the levonorgestrel IUD is associated with shorter duration of breastfeeding and less exclusive breastfeeding. Further studies are needed of the effects of early initiation of progestin-only methods on women’s lactation experience. PMID:22018124

Comparing cognition by integrating concept learning, proactive interference, and list memory.

PubMed

Wright, Anthony A; Kelly, Debbie M; Katz, Jeffrey S

2018-06-01

This article describes an approach for training a variety of species to learn the abstract concept of same/different, which in turn forms the basis for testing proactive interference and list memory. The stimulus set for concept-learning training was progressively doubled from 8, 16, 32, 64, 128 . . . to 1,024 different pictures with novel-stimulus transfer following learning. All species fully learned the same/different abstract concept: capuchin and rhesus monkeys learned more readily than pigeons; nutcrackers and magpies were at least equivalent to monkeys and transferred somewhat better following initial training sets. A similar task using the 1,024-picture set plus delays was used to test proactive interference on occasional trials. Pigeons revealed greater interference with 10-s than with 1-s delays, whereas delay time had no effect on rhesus monkeys, suggesting that the monkeys' interference was event based. This same single-item same/different task was expanded to a 4-item list memory task to test animal list memory. Humans were tested similarly with lists of kaleidoscope pictures. Delays between the list and test were manipulated, resulting in strong initial recency effects (i.e., strong 4th-item memory) at short delays and changing to a strong primacy effect (i.e., strong 1st-item memory) at long delays (pigeons 0-s to 10-s delays; monkeys 0-s to 30-s delays; humans 0-s to 100-s delays). Results and findings are discussed in terms of these species' cognition and memory comparisons, evolutionary implications, and future directions for testing other species in these synergistically related tasks.

Longest delayed hemothorax reported after blunt chest injury.

PubMed

Yap, Darren; Ng, Miane; Chaudhury, Madhu; Mbakada, Nik

2018-01-01

Blunt chest injury is a common presentation to the emergency department. However, a delayed hemothorax after blunt trauma is rare; current literature reports a delay of up to 30days. We present a case of 44-day delay in hemothorax which has not been previously reported in current literature. A 52-year-old Caucasian male first presented to the emergency department complaining of persistent right sided chest pain 2weeks after having slipped on a wet surface at home. His initial chest X-ray showed fractures of the right 7th and 8th ribs without a hemothorax or pneumothorax. He returned 30days after the initial consultation (44days post-trauma) having increasing shortness of breath. A chest X-ray this time revealed a large right hemothorax and 1850ml of blood drained from his chest. There was a complete resolution of the hemothorax within 48h and the patient was discharged after a 6-week follow-up with the chest physicians. Delayed hemothorax after blunt trauma is a rare clinical occurrence but associated with significant morbidity and mortality. The management of delayed hemothorax includes draining the hemothorax and controlling the bleeding. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should be vigilant and weary that hemothorax could be a possibility after a chest injury despite a delay in presentation. A knowledge of delayed hemothorax will prompt physicians in providing important advice, warning signs and information to patients after a chest injury to avoid a delay in seeking medical attention. Copyright © 2017 Elsevier Inc. All rights reserved.

Humans Optimize Decision-Making by Delaying Decision Onset

PubMed Central

Teichert, Tobias; Ferrera, Vincent P.; Grinband, Jack

2014-01-01

Why do humans make errors on seemingly trivial perceptual decisions? It has been shown that such errors occur in part because the decision process (evidence accumulation) is initiated before selective attention has isolated the relevant sensory information from salient distractors. Nevertheless, it is typically assumed that subjects increase accuracy by prolonging the decision process rather than delaying decision onset. To date it has not been tested whether humans can strategically delay decision onset to increase response accuracy. To address this question we measured the time course of selective attention in a motion interference task using a novel variant of the response signal paradigm. Based on these measurements we estimated time-dependent drift rate and showed that subjects should in principle be able trade speed for accuracy very effectively by delaying decision onset. Using the time-dependent estimate of drift rate we show that subjects indeed delay decision onset in addition to raising response threshold when asked to stress accuracy over speed in a free reaction version of the same motion-interference task. These findings show that decision onset is a critical aspect of the decision process that can be adjusted to effectively improve decision accuracy. PMID:24599295

Early versus delayed initiation of antiretroviral therapy for Indian HIV-Infected individuals with tuberculosis on antituberculosis treatment.

PubMed

Sinha, Sanjeev; Shekhar, Rahul C; Singh, Gurjeet; Shah, Nipam; Ahmad, Hafiz; Kumar, Narendra; Sharma, Surendra K; Samantaray, J C; Ranjan, Sanjai; Ekka, Meera; Sreenivas, Vishnu; Mitsuyasu, Ronald T

2012-07-31

For antiretroviral therapy (ART) naive human immunodeficiency virus (HIV) infected adults suffering from tuberculosis (TB), there is uncertainty about the optimal time to initiate highly active antiretroviral therapy (HAART) after starting antituberculosis treatment (ATT), in order to minimize mortality, HIV disease progression, and adverse events. In a randomized, open label trial at All India Institute of Medical Sciences, New Delhi, India, eligible HIV positive individuals with a diagnosis of TB were randomly assigned to receive HAART after 2-4 or 8-12 weeks of starting ATT, and were followed for 12 months after HAART initiation. Participants received directly observed therapy short course (DOTS) for TB, and an antiretroviral regimen comprising stavudine or zidovudine, lamivudine, and efavirenz. Primary end points were death from any cause, and progression of HIV disease marked by failure of ART. A total of 150 patients with HIV and TB were initiated on HAART: 88 received it after 2-4 weeks (early ART) and 62 after 8-12 weeks (delayed ART) of starting ATT. There was no significant difference in mortality between the groups after the introduction of HAART. However, incidence of ART failure was 31% in delayed versus 16% in early ART arm (p = 0.045). Kaplan Meier disease progression free survival at 12 months was 79% for early versus 64% for the delayed ART arm (p = 0.05). Rates of adverse events were similar. Early initiation of HAART for patients with HIV and TB significantly decreases incidence of HIV disease progression and has good tolerability. CTRI/2011/12/002260.

Maritime Evaluation of Aerosol Fire Knock Down Tools. Part 2: Toxicity and Corrosion Potential

DTIC Science & Technology

2014-02-01

determined using paramagnetic sensor technology, while CO and CO2 concentrations were measured, respectively, via gas filter correlation and single...time response of each sensor in the unit. Since it is important to account for this delay in response during analysis and interpretation of measured...within, the compartment as well as confinement and extinguishment of the fire. 1 The initial response of the NOx analyzer and delay in sensor

Pathways to multidrug-resistant tuberculosis diagnosis and treatment initiation: a qualitative comparison of patients' experiences in the era of rapid molecular diagnostic tests.

PubMed

Naidoo, Pren; van Niekerk, Margaret; du Toit, Elizabeth; Beyers, Nulda; Leon, Natalie

2015-10-28

Although new molecular diagnostic tests such as GenoType MTBDRplus and Xpert® MTB/RIF have reduced multidrug-resistant tuberculosis (MDR-TB) treatment initiation times, patients' experiences of diagnosis and treatment initiation are not known. This study aimed to explore and compare MDR-TB patients' experiences of their diagnostic and treatment initiation pathway in GenoType MTBDRplus and Xpert® MTB/RIF-based diagnostic algorithms. The study was undertaken in Cape Town, South Africa where primary health-care services provided free TB diagnosis and treatment. A smear, culture and GenoType MTBDRplus diagnostic algorithm was used in 2010, with Xpert® MTB/RIF phased in from 2011-2013. Participants diagnosed in each algorithm at four facilities were purposively sampled, stratifying by age, gender and MDR-TB risk profiles. We conducted in-depth qualitative interviews using a semi-structured interview guide. Through constant comparative analysis we induced common and divergent themes related to symptom recognition, health-care access, testing for MDR-TB and treatment initiation within and between groups. Data were triangulated with clinical information and health visit data from a structured questionnaire. We identified both enablers and barriers to early MDR-TB diagnosis and treatment. Half the patients had previously been treated for TB; most recognised recurring symptoms and reported early health-seeking. Those who attributed symptoms to other causes delayed health-seeking. Perceptions of poor public sector services were prevalent and may have contributed both to deferred health-seeking and to patient's use of the private sector, contributing to delays. However, once on treatment, most patients expressed satisfaction with public sector care. Two patients in the Xpert® MTB/RIF-based algorithm exemplified its potential to reduce delays, commencing MDR-TB treatment within a week of their first health contact. However, most patients in both algorithms experienced substantial delays. Avoidable health system delays resulted from providers not testing for TB at initial health contact, non-adherence to testing algorithms, results not being available and failure to promptly recall patients with positive results. Whilst the introduction of rapid tests such as Xpert® MTB/RIF can expedite MDR-TB diagnosis and treatment initiation, the full benefits are unlikely to be realised without reducing delays in health-seeking and addressing the structural barriers present in the health-care system.

Ionospheric corrections to precise time transfer using GPS

NASA Technical Reports Server (NTRS)

Snow, Robert W.; Osborne, Allen W., III; Klobuchar, John A.; Doherty, Patricia H.

1994-01-01

The free electrons in the earth's ionosphere can retard the time of reception of GPS signals received at a ground station, compared to their time in free space, by many tens of nanoseconds, thus limiting the accuracy of time transfer by GPS. The amount of the ionospheric time delay is proportional to the total number of electrons encountered by the wave on its path from each GPS satellite to a receiver. This integrated number of electrons is called Total Electron Content, or TEC. Dual frequency GPS receivers designed by Allen Osborne Associates, Inc. (AOA) directly measure both the ionospheric differential group delay and the differential carrier phase advance for the two GPS frequencies and derive from this the TEC between the receiver and each GPS satellite in track. The group delay information is mainly used to provide an absolute calibration to the relative differential carrier phase, which is an extremely precise measure of relative TEC. The AOA Mini-Rogue ICS-4Z and the AOA TurboRogue ICS-4000Z receivers normally operate using the GPS P code, when available, and switch to cross-correlation signal processing when the GPS satellites are in the Anti-Spoofing (A-S) mode and the P code is encrypted. An AOA ICS-Z receiver has been operated continuously for over a year at Hanscom AFB, MA to determine the statistics of the variability of the TEC parameter using signals from up to four different directions simultaneously. The 4-channel ICS-4Z and the 8-channel ICS-4000Z, have proven capabilities to make precise, well calibrated, measurements of the ionosphere in several directions simultaneously. In addition to providing ionospheric corrections for precise time transfer via satellite, this dual frequency design allows full code and automatic codeless operation of both the differential group delay and differential carrier phase for numerous ionospheric experiments being conducted. Statistical results of the data collected from the ICS-4Z during the initial year of ionospheric time delay in the northeastern U.S., and initial results with the ICS-4000Z, will be presented.

The Time-Course of Lexical Activation During Sentence Comprehension in People With Aphasia

PubMed Central

Ferrill, Michelle; Love, Tracy; Walenski, Matthew; Shapiro, Lewis P.

2012-01-01

Purpose To investigate the time-course of processing of lexical items in auditorily presented canonical (subject–verb–object) constructions in young, neurologically unimpaired control participants and participants with left-hemisphere damage and agrammatic aphasia. Method A cross modal picture priming (CMPP) paradigm was used to test 114 control participants and 8 participants with agrammatic aphasia for priming of a lexical item (direct object noun) immediately after it is initially encountered in the ongoing auditory stream and at 3 additional time points at 400-ms intervals. Results The control participants demonstrated immediate activation of the lexical item, followed by a rapid loss (decay). The participants with aphasia demonstrated delayed activation of the lexical item. Conclusion This evidence supports the hypothesis of a delay in lexical activation in people with agrammatic aphasia. The delay in lexical activation feeds syntactic processing too slowly, contributing to comprehension deficits in people with agrammatic aphasia. PMID:22355007

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, S.; Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049; Beeson, S.

Self-induced gaseous plasma is evaluated as active opening switch medium for pulsed high power microwave radiation. The self-induced plasma switch is investigated for N{sub 2} and Ar environments under pressure conditions ranging from 25 to 700 Torr. A multi-pass TE{sub 111} resonator is used to significantly reduce the delay time inherently associated with plasma generation. The plasma forms under the pulsed excitation of a 4 MW magnetron inside the central dielectric tube of the resonator, which isolates the inner atmospheric gas from the outer vacuum environment. The path from the power source to the load is designed such that the pulse passesmore » through the plasma twice with a 35 ns delay between these two passes. In the first pass, initial plasma density is generated, while the second affects the transition to a highly reflective state with as much as 30 dB attenuation. Experimental data revealed that virtually zero delay time may be achieved for N{sub 2} at 25 Torr. A two-dimensional fluid model was developed to study the plasma formation times for comparison with experimental data. The delay time predicted from this model agrees well with the experimental values in the lower pressure regime (error < 25%), however, due to filamentary plasma formation at higher pressures, simulated delay times may be underestimated by as much as 50%.« less

The Influence of Procedure Delay on Resource Utilization: A National Study of Patients with Open Tibial Fracture

PubMed Central

Sears, Erika Davis; Burke, James F.; Davis, Matthew M.; Chung, Kevin C.

2016-01-01

Background The purpose of this study is to 1) understand national variation in delay of emergency procedures in patients with open tibial fracture at the hospital level and 2) compare length of stay (LOS) and cost in patients cared for at the best and worst performing hospitals for delay. Methods We retrospectively analyzed the 2003 – 2009 Nationwide Inpatient Sample. Adult patients with primary diagnosis of open tibial fracture were selected for inclusion. We calculated hospital probability of delay of emergency procedures beyond the day of admission (day 0). Multilevel linear regression random effects models were created to evaluate the relationship between the treating hospital’s tendency for delay (in quartiles) and the log-transformed outcomes of LOS and cost, while adjusting for patient and hospital variables. Results The final sample included 7,029 patients from 332 hospitals. Adjusted analyses demonstrate that patients treated at hospitals in the fourth (worst) quartile for delay were estimated to have 12% (95% CI 2–21%) higher cost compared to patients treated at hospitals in the first quartile. In addition, patients treated at hospitals in the fourth quartile had an estimated 11% (CI 4–17%) longer LOS compared to patients treated at hospitals in the first quartile. Conclusions Patients with open tibial fracture treated at hospitals with more timely initiation of surgical care had lower cost and shorter LOS than patients treated at hospitals with less timely initiation of care. Policies directed toward mitigating variation in care are not only beneficial for patient outcomes, but may also reduce unnecessary waste. Level II (Prognostic) PMID:23142940

Integral sliding mode-based attitude coordinated tracking for spacecraft formation with communication delays

NASA Astrophysics Data System (ADS)

Zhang, Jian; Hu, Qinglei; Xie, Wenbo

2017-11-01

This paper investigates the attitude coordinated tracking control for a group of rigid spacecraft under directed communication topology, in which inertia uncertainties, external disturbances, input saturation and constant time-delays between the formation members are handled. Initially, the nominal system with communication delays is studied. A delay-dependent controller is proposed by using Lyapunov-Krasovskii function and sufficient condition for system stability is derived. Then, an integral sliding manifold is designed and adaptive control approach is employed to deal with the total perturbation. Meanwhile, the boundary layer method is introduced to alleviate the unexpected chattering as system trajectories cross the switching surface. Finally, numerical simulation results are presented to validate the effectiveness and robustness of the proposed control strategy.

Towards sensor array materials: can failure be delayed?

PubMed Central

Mekid, Samir; Saheb, Nouari; Khan, Shafique M A; Qureshi, Khurram K

2015-01-01

Further to prior development in enhancing structural health using smart materials, an innovative class of materials characterized by the ability to feel senses like humans, i.e. ‘nervous materials’, is discussed. Designed at all scales, these materials will enhance personnel and public safety, and secure greater reliability of products. Materials may fail suddenly, but any system wishes that failure is known in good time and delayed until safe conditions are reached. Nervous materials are expected to be the solution to this statement. This new class of materials is based on the novel concept of materials capable of feeling multiple structural and external stimuli, e.g. stress, force, pressure and temperature, while feeding information back to a controller for appropriate real-time action. The strain–stress state is developed in real time with the identified and characterized source of stimulus, with optimized time response to retrieve initial specified conditions, e.g. shape and strength. Sensors are volumetrically embedded and distributed, emulating the human nervous system. Immediate applications are in aircraft, cars, nuclear energy and robotics. Such materials will reduce maintenance costs, detect initial failures and delay them with self-healing. This article reviews the common aspects and challenges surrounding this new class of materials with types of sensors to be embedded seamlessly or inherently, including appropriate embedding manufacturing techniques with modeling and simulation methods. PMID:27877794

Towards sensor array materials: can failure be delayed?

NASA Astrophysics Data System (ADS)

Mekid, Samir; Saheb, Nouari; Khan, Shafique M. A.; Qureshi, Khurram K.

2015-06-01

Further to prior development in enhancing structural health using smart materials, an innovative class of materials characterized by the ability to feel senses like humans, i.e. ‘nervous materials’, is discussed. Designed at all scales, these materials will enhance personnel and public safety, and secure greater reliability of products. Materials may fail suddenly, but any system wishes that failure is known in good time and delayed until safe conditions are reached. Nervous materials are expected to be the solution to this statement. This new class of materials is based on the novel concept of materials capable of feeling multiple structural and external stimuli, e.g. stress, force, pressure and temperature, while feeding information back to a controller for appropriate real-time action. The strain-stress state is developed in real time with the identified and characterized source of stimulus, with optimized time response to retrieve initial specified conditions, e.g. shape and strength. Sensors are volumetrically embedded and distributed, emulating the human nervous system. Immediate applications are in aircraft, cars, nuclear energy and robotics. Such materials will reduce maintenance costs, detect initial failures and delay them with self-healing. This article reviews the common aspects and challenges surrounding this new class of materials with types of sensors to be embedded seamlessly or inherently, including appropriate embedding manufacturing techniques with modeling and simulation methods.

Does delayed pushing in the second stage of labor impact perinatal outcomes?

PubMed

Frey, Heather A; Tuuli, Methodius G; Cortez, Sarah; Odibo, Anthony O; Roehl, Kimberly A; Shanks, Anthony L; Macones, George A; Cahill, Alison G

2012-11-01

To estimate maternal, neonatal, and labor outcomes associated with delayed pushing. A retrospective cohort study of all consecutive women admitted to a single institution in labor at term who reached the second stage of labor. Pregnancies with multiple fetuses or major anomalies were excluded. Delayed pushing was defined as initiation of pushing ≥60 minutes after complete dilatation. Primary outcome was mode of delivery. Multivariable logistic regression was used to control for confounding. Of the 5290 women who met inclusion criteria, 471 (8.9%) employed delayed pushing, and 4819 (91.1%) pushed immediately. Delayed pushing was associated with increased rates of cesarean, operative vaginal delivery, maternal fever, and lower arterial cord pH. Duration of the second stage and length of time spent pushing were significantly longer with delayed pushing. Delayed pushing is associated with lower rates of spontaneous vaginal delivery and increased adverse maternal and neonatal outcomes. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Short-Term Anticoagulant Therapy and Thrombus Location Are Independent Risk Factors for Delayed Recanalization of Deep Vein Thrombosis

PubMed Central

Zhang, Chuanlin; Fu, Qining; Zhao, Yu; Mu, Shaoyu; Liu, Liping

2016-01-01

Background Prompt recanalization of the vein containing the thrombus is an important goal during the initial treatment of DVT, and risk factors for delayed recanalization in patients with deep vein thrombosis (DVT) in the lower extremities need to be determined. Material/Methods A total of 174 patients with DVT in lower extremities were recruited from June 2014 to March 2015 at our hospital. Duplex ultrasound scanning was conducted for all patients at 1 and 6 months after baseline evaluation. We divided the patients into recanalization and non-recanalization groups and analyzed risk factors for delayed recanalization. Results The univariate analysis revealed that an oral anticoagulant time of less than 3 months and venous thrombus location were risk factors for delayed recanalization (P<0.01). However, age, gender, hypertension, diabetes, pulmonary embolism, incidence factors, the use of catheter-directed thrombolytic (CDT) drugs, and inferior vena cava filter (IVCF) implantation had no influence on the incidence of delayed recanalization in patients with DVT (P>0.05). The multivariate analysis showed that patients with an anticoagulant time of less than 3 months had a lower incidence of recanalization than those with an anticoagulant time of more than 3 months (OR=2.358, P<0.05). The risk of delayed recanalization in patients with proximal DVT was 7 times higher than that in patients with distal DVT. Conclusions Duration of anticoagulant treatment of less than 3 months and venous thrombus location are independent risk factors for delayed recanalization of DVT in the lower extremities. PMID:26790571

Testing the Delayed Gamma Capability in MCNP6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weldon, Robert A.; Fensin, Michael L.; McKinney, Gregg W.

The mission of the Domestic Nuclear Detection Office is to quickly and reliably detect unauthorized attempts to import or transport special nuclear material for use against the United States. Developing detection equipment to meet this objective requires accurate simulation of both the detectable signature and detection mechanism. A delayed particle capability was initially added to MCNPX 2.6.A in 2005 to sample the radioactive fission product parents and emit decay particles resulting from the decay chain. To meet the objectives of detection scenario modeling, the capability was designed to sample a particular time for emitting particular multiplicity of a particular energy.more » Because the sampling process of selecting both time and energy is interdependent, to linearize the time and emission sampling, atom densities are computed at several discrete time steps, and the time-integrated production is computed by multiplying the atom density by the decay constant and time step size to produce a cumulative distribution function for sampling the emission time, energy, and multiplicity. The delayed particle capability was initially given a time-bin structure to help reasonably reproduce, from a qualitative sense, a fission benchmark by Beddingfield, which examined the delayed gamma emission. This original benchmark was only qualitative and did not contain the magnitudes of the actual measured data but did contain relative graphical representation of the spectra. A better benchmark with measured data was later provided by Hunt, Mozin, Reedy, Selpel, and Tobin at the Idaho Accelerator Center; however, because of the complexity of the benchmark setup, sizable systematic errors were expected in the modeling, and initial results compared to MCNPX 2.7.0 showed errors outside of statistical fluctuation. Presented in this paper is a more simplified approach to benchmarking, utilizing closed form analytic solutions to the granddaughter equations for particular sets of decay systems. We examine five different decay chains (two-stage decay to stable) and show the predictability of the MCNP6 delayed gamma feature. Results do show that while the default delayed gamma calculations available in the MCNP6 1.0 release can give accurate results for some isotopes (e.g., 137Ba), the percent differences between the closed form analytic solutions and the MCNP6 calculations were often >40% ( 28Mg, 28Al, 42K, 47Ca, 47Sc, 60Co). With the MCNP6 1.1 Beta release, the tenth entry on the DBCN card allows improved calculation within <5% as compared to the closed form analytic solutions for immediate parent emissions and transient equilibrium systems. While the tenth entry on the DBCN card for MCNP6 1.1 gives much better results for transient equilibrium systems and parent emissions in general, it does little to improve daughter emissions of secular equilibrium systems. Finally, hypotheses were presented as to why daughter emissions of secular equilibrium systems might be mispredicted in some cases and not in others.« less

78 FR 39299 - National Institute of Neurological Disorders and Stroke; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-01

... Disorders and Stroke Special, Emphasis Panel, International Traumatic Brain Injury Research Initiative. Date... Traumatic Encephalopathy and Delayed Effects of Traumatic Brain Injury. Date: July 19, 2013. Time: 1:30 p.m...

Controller design for global fixed-time synchronization of delayed neural networks with discontinuous activations.

PubMed

Wang, Leimin; Zeng, Zhigang; Hu, Junhao; Wang, Xiaoping

2017-03-01

This paper addresses the controller design problem for global fixed-time synchronization of delayed neural networks (DNNs) with discontinuous activations. To solve this problem, adaptive control and state feedback control laws are designed. Then based on the two controllers and two lemmas, the error system is proved to be globally asymptotically stable and even fixed-time stable. Moreover, some sufficient and easy checked conditions are derived to guarantee the global synchronization of drive and response systems in fixed time. It is noted that the settling time functional for fixed-time synchronization is independent on initial conditions. Our fixed-time synchronization results contain the finite-time results as the special cases by choosing different values of the two controllers. Finally, theoretical results are supported by numerical simulations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of Delayed-Particle Emission Signatures for Pyroprocessing. Part 1: ABTR Fuel Assembly.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durkee, Jr., Joe W.

A three-part study is conducted using the MCNP6 Monte Carlo radiation-transport code to calculate delayed-neutron (DN) and delayed-gamma (DG) emission signatures for nondestructive assay (NDA) metal-fuel pyroprocessing. In Part 1, MCNP6 is used to produce irradiation-induced used nuclear fuel (UNF) isotopic inventories for an Argonne National Laboratory (ANL) Advanced Burner Test Reactor (ABTR) preconceptual design fuel assembly (FA) model. The initial fuel inventory consists of uranium mixed with light-water-reactor transuranic (TRU) waste and 10 wt% zirconium (U-LWR-SFTRU-10%Zr). To facilitate understanding, parametric evaluation is done using models for 3% and 5% initial 235U a% enrichments, burnups of 5, 10, 15, 20,more » 30, …, 120 GWd/MTIHM, and 3-, 5-, 10-, 20-, and 30- year cooling times. Detailed delayed-particle radioisotope source terms for the irradiate FA are created using BAMF-DRT and SOURCES3A. Using simulation tallies, DG activity ratios (DGARs) are developed for 134Cs/ 137Cs 134Cs/ 154Eu, and 154Eu/ 137Cs markers as a function of (1) burnup and (2) actinide mass, including elemental uranium, neptunium, plutonium, americium, and curium. Spectral-integrated DN emission is also tallied. The study reveals a rich assortment of DGAR behavior as a function of DGAR type, enrichment, burnup, and cooling time. Similarly, DN emission plots show variation as a function of burnup and of actinide mass. Sensitivity of DGAR and DN signatures to initial 235U enrichment, burnup, and cooling time is evident. Comparisons of the ABTR radiation signatures and radiation signatures previously reported for a generic Westinghouse oxide-fuel assembly indicate that there are pronounced differences in the ABTR and Westinghouse oxide-fuel DN and DG signatures. These differences are largely attributable to the initial TRU inventory in the ABTR fuel. The actinide and nonactinide inventories for the FA models serve as source materials for the pre- and postelectrorefining models to be reported in Parts 2 and 3.« less

The relative temporal sequence of decline in mobility and cognition among initially unimpaired older adults: Results from the Baltimore Longitudinal Study of Aging.

PubMed

Tian, Qu; An, Yang; Resnick, Susan M; Studenski, Stephanie

2017-05-01

most older individuals who experience mobility decline, also show cognitive decline, but whether cognitive decline precedes or follows mobility limitation is not well understood. examine the temporal sequence of mobility and cognition among initially unimpaired older adults. mobility and cognition were assessed every 2 years for 6 years in 412 participants aged ≥60 with initially unimpaired cognition and gait speed. Using autoregressive models, accounting for the dependent variable from the prior assessment, baseline age, sex, body mass index and education, we examine the temporal sequence of change in mobility (6 m usual gait speed, 400 m fast walk time) and executive function (visuoperceptual speed: Digit Symbol Substitution Test (DSST); cognitive flexibility: Trail Making Test part B (TMT-B)) or memory (California Verbal Learning Test (CVLT) immediate, short-delay, long-delay). there was a bidirectional relationship over time between slower usual gait speed and both poorer DSST and TMT-B scores (Bonferroni-corrected P < 0.005). In contrast, slower 400 m fast walk time predicted subsequent poorer DSST, TMT-B, CVLT immediate recall and CVLT short-delay scores (P < 0.005), while these measures did not predict subsequent 400 m fast walk time (P > 0.005). among initially unimpaired older adults, the temporal relationship between usual gait speed and executive function is bidirectional, with each predicting change in the other, while poor fast walking performance predicts future executive function and memory changes but not vice versa. Challenging tasks like the 400 m walk appear superior to usual gait speed for predicting executive function and memory change in unimpaired older adults. Published by Oxford University Press on behalf of the British Geriatrics Society 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

The impact of 5-hydroxytryptamine-receptor antagonists on chemotherapy treatment adherence, treatment delay, and nausea and vomiting.

PubMed

Palli, Swetha Rao; Grabner, Michael; Quimbo, Ralph A; Rugo, Hope S

2015-01-01

To determine the incidence of chemotherapy-induced nausea/vomiting (CINV) and chemotherapy treatment delay and adherence among patients receiving palonosetron versus other 5-hydroxytryptamine receptor antagonist (5-HT3 RA) antiemetics. This retrospective claims analysis included adults with primary malignancies who initiated treatment consisting of single-day intravenous highly emetogenic chemotherapy (HEC) or moderately EC (MEC) regimens. Treatment delay was defined as a gap in treatment at least twice the National Comprehensive Cancer Network-specified cycle length, specific to each chemotherapy regimen. Treatment adherence was determined by the percentage of patients who received the regimen-specific recommended number of chemotherapy cycles within the recommended time frame. We identified 1,832 palonosetron and 2,387 other 5-HT3 RA ("other") patients who initiated HEC therapy, and 1,350 palonosetron users and 1,379 patients on other antiemetics who initiated MEC therapy. Fewer patients receiving palonosetron experienced CINV versus other (HEC, 27.5% versus 32.2%, P=0.0011; MEC, 36.1% versus 41.7%, P=0.0026), and fewer treatment delays occurred among patients receiving palonosetron versus other (HEC, 3.2% versus 6.0%, P<0.0001; MEC, 17.0% versus 26.8%, P<0.0001). Compared with the other cohort, patients receiving palonosetron were significantly more adherent to the index chemotherapy regimen with respect to the recommended time frame (HEC, 74.7% versus 69.7%, P=0.0004; MEC, 43.1% versus 37.3%, P=0.0019) and dosage (HEC, 27.3% versus 25.8%, P=0.0004; MEC, 15.0% versus 12.6%, P=0.0019). Palonosetron more effectively reduced occurrence of CINV in patients receiving HEC or MEC compared with other agents in this real-world setting. Additionally, patients receiving palonosetron had better adherence and fewer treatment delays than patients receiving other 5-HT3 RAs.

The impact of 5-hydroxytryptamine-receptor antagonists on chemotherapy treatment adherence, treatment delay, and nausea and vomiting

PubMed Central

Palli, Swetha Rao; Grabner, Michael; Quimbo, Ralph A; Rugo, Hope S

2015-01-01

Purpose To determine the incidence of chemotherapy-induced nausea/vomiting (CINV) and chemotherapy treatment delay and adherence among patients receiving palonosetron versus other 5-hydroxytryptamine receptor antagonist (5-HT3 RA) antiemetics. Materials and methods This retrospective claims analysis included adults with primary malignancies who initiated treatment consisting of single-day intravenous highly emetogenic chemotherapy (HEC) or moderately EC (MEC) regimens. Treatment delay was defined as a gap in treatment at least twice the National Comprehensive Cancer Network-specified cycle length, specific to each chemotherapy regimen. Treatment adherence was determined by the percentage of patients who received the regimen-specific recommended number of chemotherapy cycles within the recommended time frame. Results We identified 1,832 palonosetron and 2,387 other 5-HT3 RA (“other”) patients who initiated HEC therapy, and 1,350 palonosetron users and 1,379 patients on other antiemetics who initiated MEC therapy. Fewer patients receiving palonosetron experienced CINV versus other (HEC, 27.5% versus 32.2%, P=0.0011; MEC, 36.1% versus 41.7%, P=0.0026), and fewer treatment delays occurred among patients receiving palonosetron versus other (HEC, 3.2% versus 6.0%, P<0.0001; MEC, 17.0% versus 26.8%, P<0.0001). Compared with the other cohort, patients receiving palonosetron were significantly more adherent to the index chemotherapy regimen with respect to the recommended time frame (HEC, 74.7% versus 69.7%, P=0.0004; MEC, 43.1% versus 37.3%, P=0.0019) and dosage (HEC, 27.3% versus 25.8%, P=0.0004; MEC, 15.0% versus 12.6%, P=0.0019). Conclusion Palonosetron more effectively reduced occurrence of CINV in patients receiving HEC or MEC compared with other agents in this real-world setting. Additionally, patients receiving palonosetron had better adherence and fewer treatment delays than patients receiving other 5-HT3 RAs. PMID:26124681

Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction

NASA Astrophysics Data System (ADS)

Zapartas, E.; de Mink, S. E.; Izzard, R. G.; Yoon, S.-C.; Badenes, C.; Götberg, Y.; de Koter, A.; Neijssel, C. J.; Renzo, M.; Schootemeijer, A.; Shrotriya, T. S.

2017-05-01

Most massive stars, the progenitors of core-collapse supernovae, are in close binary systems and may interact with their companion through mass transfer or merging. We undertake a population synthesis study to compute the delay-time distribution of core-collapse supernovae, that is, the supernova rate versus time following a starburst, taking into account binary interactions. We test the systematic robustness of our results by running various simulations to account for the uncertainties in our standard assumptions. We find that a significant fraction, %, of core-collapse supernovae are "late", that is, they occur 50-200 Myr after birth, when all massive single stars have already exploded. These late events originate predominantly from binary systems with at least one, or, in most cases, with both stars initially being of intermediate mass (4-8 M⊙). The main evolutionary channels that contribute often involve either the merging of the initially more massive primary star with its companion or the engulfment of the remaining core of the primary by the expanding secondary that has accreted mass at an earlier evolutionary stage. Also, the total number of core-collapse supernovae increases by % because of binarity for the same initial stellar mass. The high rate implies that we should have already observed such late core-collapse supernovae, but have not recognized them as such. We argue that φ Persei is a likely progenitor and that eccentric neutron star - white dwarf systems are likely descendants. Late events can help explain the discrepancy in the delay-time distributions derived from supernova remnants in the Magellanic Clouds and extragalactic type Ia events, lowering the contribution of prompt Ia events. We discuss ways to test these predictions and speculate on the implications for supernova feedback in simulations of galaxy evolution.

Memory Impairment in Multiple Sclerosis is Due to a Core Deficit in Initial Learning

PubMed Central

DeLuca, John; Leavitt, Victoria M.; Chiaravalloti, Nancy; Wylie, Glenn

2013-01-01

Persons with multiple sclerosis (MS) suffer memory impairment, but research on the nature of MS-related memory problems is mixed. Some have argued for a core deficit in retrieval, while others have identified deficient initial learning as the core deficit. We used a selective reminding paradigm to determine whether deficient initial learning or delayed retrieval represents the primary memory deficit in 44 persons with MS. Brain atrophy was measured from high-resolution MRIs. Regression analyses examined the impact of brain atrophy on (a) initial learning and delayed retrieval separately, and then (b) delayed retrieval controlling for initial learning. Brain atrophy was negatively associated with both initial learning and delayed retrieval (ps < .01), but brain atrophy was unrelated to retrieval when controlling for initial learning (p > .05). In addition, brain atrophy was associated with inefficient learning across initial acquisition trials, and brain atrophy was unrelated to delayed recall among MS subjects who successfully acquired the word list (although such learning frequently required many exposures). Taken together, memory deficits in MS are a result of deficits in initial learning; moreover, initial learning mediates the relationship between brain atrophy and subsequent retrieval, thereby supporting the core learning-deficit hypothesis of memory impairment in MS. PMID:23832311

Time correlation between mononucleosis and initial symptoms of MS

PubMed Central

Endriz, John; Ho, Peggy P.

2017-01-01

Objective: To determine the average age of MS onset vs the age at which Epstein-Barr infection has previously occurred and stratify this analysis by sex and the blood level of Epstein-Barr nuclear antigen 1 (EBNA1) antibody. Methods: Using infectious mononucleosis (IM) as a temporal marker in data from the Swedish epidemiologic investigation of MS, 259 adult IM/MS cases were identified and then augmented to account for “missing” childhood data so that the average age of MS onset could be determined for cases binned by age of IM (as stratified by sex and EBNA1 titer level). Results: Mean age of IM vs mean age of MS reveals a positive time correlation for all IM ages (from ∼5 to ∼30 years), with IM-to-MS delay decreasing with increased age. When bifurcated by sex or EBNA1 blood titer levels, males and high-titer subpopulations show even stronger positive time correlation, while females and low-titer populations show negative time correlation in early childhood (long IM/MS delay). The correlation becomes positive in females beyond puberty. Conclusions: IM/MS time correlation implies causality if IM is time random. Alternative confounding models seem implausible, in light of constraints imposed by time-invariant delay observed here. Childhood infection with Epstein-Barr virus (EBV) in females and/or those genetically prone to low EBNA1 blood titers will develop MS slowly. Males and/or high EBNA1-prone develop MS more rapidly following IM infection at all ages. For all, postpubescent EBV infection is critical for the initiation and rapid development of MS. PMID:28271078

Delayed onset of lactogenesis among first-time mothers is related to maternal obesity and factors associated with ineffective breastfeeding.

PubMed

Nommsen-Rivers, Laurie A; Chantry, Caroline J; Peerson, Janet M; Cohen, Roberta J; Dewey, Kathryn G

2010-09-01

Delayed onset of lactogenesis (OL) is most common in primiparas and increases the risk of excess neonatal weight loss, formula supplementation, and early weaning. We examined variables associated with delayed OL among first-time mothers who delivered at term and initiated breastfeeding (n = 431). We conducted in-person interviews during pregnancy and at days 0, 3, and 7 postpartum and extracted obstetric and newborn information from medical records. We defined OL as delayed if it occurred after 72 h and used chi-square analysis to examine its association with potential risk factors across 6 dimensions: 1) prenatal characteristics, 2) maternal anthropometric characteristics, 3) labor and delivery experience, 4) newborn characteristics, 5) maternal postpartum factors, and 6) infant feeding variables. We examined independent associations by using multivariable logistic regression analysis. Median OL was 68.9 h postpartum; 44% of mothers experienced delayed OL. We observed significant bivariate associations between delayed OL and variables in all 6 dimensions (P < 0.05). In a multivariate model adjusted for prenatal feeding intentions, independent risk factors for delayed OL were maternal age > or =30 y, body mass index in the overweight or obese range, birth weight >3600 g, absence of nipple discomfort between 0-3 d postpartum, and infant failing to "breastfeed well" > or =2 times in the first 24 h. Postpartum edema was significant in an alternate model excluding body mass index (P < 0.05). The risk factors for delayed OL are multidimensional. Public health and obstetric and maternity care interventions are needed to address what has become an alarmingly common problem among primiparas.

Timing considerations of Helmet Mounted Display performance

NASA Technical Reports Server (NTRS)

Tharp, Gregory; Liu, Andrew; French, Lloyd; Lai, Steve; Stark, Lawrence

1992-01-01

The Helmet Mounted Display (HMD) system developed in our lab should be a useful teleoperator systems display if it increases operator performance of the desired task; it can, however, introduce degradation in performance due to display update rate constraints and communication delays. Display update rates are slowed by communication bandwidth and/or computational power limitations. We used simulated 3D tracking and pick-and-place tasks to characterize performance levels for a range of update rates. Initial experiments with 3D tracking indicate that performance levels plateau at an update rate between 10 and 20 Hz. We have found that using the HMD with delay decreases performance as delay increases.

A quantitative analysis of sensitivity to the conditioned reinforcing value of terminal-link stimuli in a concurrent-chains schedule.

PubMed Central

Omino, T

1993-01-01

Pigeons were exposed to a concurrent-chains schedule in which a single variable-interval 30-s schedule was used in the initial links and fixed-time schedules were used in the terminal links. Three types of keylight conditions were used in the terminal links. In the first condition, different delays were associated with different keylight stimuli (cued condition). In the second condition, different delays were associated with the same stimulus, either a blackout (uncued blackout condition) or a white key (uncued white condition). Paired values of terminal-link fixed-time schedules differed by a constant ratio of 3:1, while the absolute value of delays was varied from 3 s to 54 s. The results showed that choice proportions for the shorter of two delays increased when the absolute size of the delays was increased for all keylight conditions. Further, the choice proportions for the shorter delay increased from the uncued blackout condition, to the uncued white condition, to the cued condition. A modified version of Fantino's (1969) delay-reduction model (expressed as a function relating the response ratio to the delay-reduction ratio) can be applied to these data by showing that sensitivity to delay reduction increased from the uncued blackout condition, to the uncued white condition, to the cued condition. Thus, the present study demonstrated that a modified version of the delay-reduction model can be used to assess quantitative differences in the terminal-link keylight condition in terms of sensitivity to delay reduction (i.e., the conditioned reinforcing value of the terminal-link keylight stimuli). PMID:8283150

Sex disparities in diagnosis of bladder cancer after initial presentation with hematuria: a nationwide claims-based investigation.

PubMed

Cohn, Joshua A; Vekhter, Benjamin; Lyttle, Christopher; Steinberg, Gary D; Large, Michael C

2014-02-15

Women have disproportionately higher mortality rates relative to incidence for bladder cancer. Multiple etiologies have been proposed, including delayed diagnosis and treatment. Guidelines recommend ruling out malignancy in men and women presenting with hematuria. This study sought to determine the difference in timing from presentation with hematuria to diagnosis of bladder cancer in women versus men. This is a retrospective population-based study examining the timing from presentation with hematuria to diagnosis of bladder cancer, based on data from the MarketScan databases, which include enrollees of more than 100 health insurance plans of approximately 40 large US employers from 2004 through 2010. All study patients presented with hematuria and were subsequently diagnosed with bladder cancer. The primary outcome measure was number of days between initial presentation with hematuria and diagnosis of bladder cancer by sex. A total of 5416 men and 2233 women met inclusion criteria. Mean days from initial hematuria claim to bladder cancer claim was significantly longer in women (85.4 versus 73.6 days, P < .001), and the proportion of women with >6 month delay in bladder cancer diagnosis was significantly higher (17.3% versus 14.1%, P < .001). Women were more likely to be diagnosed with urinary tract infection (odds ratio = 2.32, 95% confidence interval = 2.07-2.59) and less likely to undergo abdominal or pelvic imaging (odds ratio = 0.80, 95% confidence interval = 0.71-0.89). Both men and women experience significant delays between presentation with hematuria and diagnosis of bladder cancer, with longer delays for women. This may be partly responsible for the sex-based discrepancy in outcomes associated with bladder cancer. © 2013 American Cancer Society.

Growth and development in internationally adopted children: extent and timing of recovery after early adversity.

PubMed

Palacios, Jesús; Román, Maite; Camacho, Carlos

2011-03-01

Following initial adversity, internationally adopted children arrive with significant growth and developmental delays. Post-placement recovery has been widely documented, but little has been known about its extent and timing several years after placement and in children with diverse pre-adoptive experiences. A total of 289 children adopted from six countries into Spanish families were studied. Growth and psychological development were considered on arrival and after an average of over 3 years. Growth and developmental initial delays affected a substantial percentage of the children. Post-adoption recovery seemed quicker and more complete in weight and height than in head circumference and psychological development. Initial and later values were correlated, but growth-development relation on arrival subsequently lost significance. Most of the catch-up happened in the first three post-adoption years. Adoption offers an impressive opportunity for recovery after previous adversity, although continuity between past and present persists. The improvement is more marked in some areas than in others and more substantial in the first post-adoption years. © 2010 Blackwell Publishing Ltd.

Offspring of depressed and anxious patients: Help-seeking after first onset of a mood and/or anxiety disorder.

PubMed

Havinga, Petra J; Hartman, Catharina A; Visser, Ellen; Nauta, Maaike H; Penninx, Brenda W J H; Boschloo, Lynn; Schoevers, Robert A

2018-02-01

Offspring of patients with depressive and/or anxiety disorders are at high risk of developing a similar disorder themselves. Early recognition and treatment may have substantial effects on prognosis. The main aim of this study was to examine the time to initial help-seeking and its determinants in offspring after the first onset of a mood and/or anxiety disorder. Data are presented of 215 offspring with a mood and/or anxiety disorder participating in a cohort study with 10 year follow-up. We determined age of disorder onset and age of initial help-seeking. Offspring characteristics (gender, IQ, age of onset, disorder type, suicidal ideation) and family characteristics (socioeconomic status, family functioning) were investigated as potential predictors of the time to initial help-seeking. The estimated overall proportion of offspring of depressed/anxious patients who eventually seek help after onset of a mood and/or anxiety disorder was 91.9%. The time to initial help-seeking was more than two years in 39.6% of the offspring. Being female, having a mood disorder or comorbid mood and anxiety disorder (relative to anxiety) and a disorder onset in adolescence or adulthood (relative to childhood) predicted a shorter time to initial help-seeking. Baseline information relied on retrospective reports. Age of onsets and age of initial help-seeking may therefore be subject to recall bias. Although most offspring eventually seek help after onset of a mood/anxiety disorder, delays in help-seeking were common, especially in specific subgroups of patients. This information may help to develop targeted strategies to reduce help-seeking delays. Copyright © 2017 Elsevier B.V. All rights reserved.

Learning and memory performance in breast cancer survivors 2 to 6 years post-treatment: the role of encoding versus forgetting.

PubMed

Root, James C; Andreotti, Charissa; Tsu, Loretta; Ellmore, Timothy M; Ahles, Tim A

2016-06-01

Our previous retrospective analysis of clinically referred breast cancer survivors' performance on learning and memory measures found a primary weakness in initial encoding of information into working memory with intact retention and recall of this same information at a delay. This suggests that survivors may misinterpret cognitive lapses as being due to forgetting when, in actuality, they were not able to properly encode this information at the time of initial exposure. Our objective in this study was to replicate and extend this pattern of performance to a research sample to increase the generalizability of this finding in a sample in which subjects were not clinically referred for cognitive issues. We contrasted learning and memory performance between breast cancer survivors on endocrine therapy 2 to 6 years post-treatment with age- and education-matched healthy controls. We then stratified lower- and higher-performing breast cancer survivors to examine specific patterns of learning and memory performance. Contrasts were generated for four aggregate visual and verbal memory variables from the California Verbal Learning Test-2 (CVLT-2) and the Brown Location Test (BLT): Single-trial Learning: Trial 1 performance, Multiple-trial Learning: Trial 5 performance, Delayed Recall: Long-delay Recall performance, and Memory Errors: False-positive errors. As predicted, breast cancer survivors' performance as a whole was significantly lower on Single-trial Learning than the healthy control group but exhibited no significant difference in Delayed Recall. In the secondary analysis contrasting lower- and higher-performing survivors on cognitive measures, the same pattern of lower Single-trial Learning performance was exhibited in both groups, with the additional finding of significantly weaker Multiple-trial Learning performance in the lower-performing breast cancer group and intact Delayed Recall performance in both groups. As with our earlier finding of weaker initial encoding with intact recall in a cohort of clinically referred breast cancer survivors, our results indicate this same profile in a research sample of breast cancer survivors. Further, when the breast cancer group was stratified by lower and higher performance, both groups exhibited significantly lower performance on initial encoding, with more pronounced encoding weakness in the lower-performing group. As in our previous research, survivors did not lose successfully encoded information over longer delays, either in the lower- or higher-performing group, again arguing against memory decay in survivors. The finding of weaker initial encoding of information together with intact delayed recall in survivors points to specific treatment interventions in rehabilitation of cognitive dysfunction. The finding of weaker initial encoding of information together with intact delayed recall in survivors points to specific treatment interventions in rehabilitation of cognitive dysfunction and is discussed.

Circumcision Status and Time to Sexual Debut Among Youth in Sub-Saharan Africa: Evidence from Six Demographic and Health Surveys.

PubMed

Kangmennaang, Joseph; Osei, Lydia; Mkandawire, Paul; Luginaah, Isaac

2016-11-01

This paper examines the relationship between circumcision status and timing of sexual debut among unmarried youth in Sub-Saharan Africa using Demographic and Health Surveys. Results from survival analysis indicate that the association between circumcision and timing of first sex is place and context specific. Compared to uncircumcised, circumcised men in Rwanda, Uganda and Namibia hasten sexual initiation, whilst circumcised youth in Ethiopia and Mali delayed sex initiation. In Togo however, we found parity in timing to sexual debut. Our multivariate results reveal that, knowledge of HIV/AIDS risk and educational level also feed into the association between circumcision and timing of sex initiation- implying that efforts to prevent new HIV infection through circumcision could benefit from a proper understanding of how diverse set of factors interact in specific contexts to shape youth's decisions to initiate early sex.

Forgetting of Foreign-Language Skills: A Corpus-Based Analysis of Online Tutoring Software.

PubMed

Ridgeway, Karl; Mozer, Michael C; Bowles, Anita R

2017-05-01

We explore the nature of forgetting in a corpus of 125,000 students learning Spanish using the Rosetta Stone ® foreign-language instruction software across 48 lessons. Students are tested on a lesson after its initial study and are then retested after a variable time lag. We observe forgetting consistent with power function decay at a rate that varies across lessons but not across students. We find that lessons which are better learned initially are forgotten more slowly, a correlation which likely reflects a latent cause such as the quality or difficulty of the lesson. We obtain improved predictive accuracy of the forgetting model by augmenting it with features that encode characteristics of a student's initial study of the lesson and the activities the student engaged in between the initial and delayed tests. The augmented model can predict 23.9% of the variance in an individual's score on the delayed test. We analyze which features best explain individual performance. Copyright © 2016 Cognitive Science Society, Inc.

Delayed Imatinib Treatment for Acute Spinal Cord Injury: Functional Recovery and Serum Biomarkers

PubMed Central

Finn, Anja; Hao, Jingxia; Wellfelt, Katrin; Josephson, Anna; Svensson, Camilla I.; Wiesenfeld-Hallin, Zsuzsanna; Eriksson, Ulf; Abrams, Mathew

2015-01-01

Abstract With no currently available drug treatment for spinal cord injury, there is a need for additional therapeutic candidates. We took the approach of repositioning existing pharmacological agents to serve as acute treatments for spinal cord injury and previously found imatinib to have positive effects on locomotor and bladder function in experimental spinal cord injury when administered immediately after the injury. However, for imatinib to have translational value, it needs to have sustained beneficial effects with delayed initiation of treatment, as well. Here, we show that imatinib improves hind limb locomotion and bladder recovery when initiation of treatment was delayed until 4 h after injury and that bladder function was improved with a delay of up to 24 h. The treatment did not induce hypersensitivity. Instead, imatinib-treated animals were generally less hypersensitive to either thermal or mechanical stimuli, compared with controls. In an effort to provide potential biomarkers, we found serum levels of three cytokines/chemokines—monocyte chemoattractant protein-1, macrophage inflammatory protein (MIP)-3α, and keratinocyte chemoattractant/growth-regulated oncogene (interleukin 8)—to increase over time with imatinib treatment and to be significantly higher in injured imatinib-treated animals than in controls during the early treatment period. This correlated to macrophage activation and autofluorescence in lymphoid organs. At the site of injury in the spinal cord, macrophage activation was instead reduced by imatinib treatment. Our data strengthen the case for clinical trials of imatinib by showing that initiation of treatment can be delayed and by identifying serum cytokines that may serve as candidate markers of effective imatinib doses. PMID:25914996

An evaluation of two methods for increasing self-initiated verbalizations in autistic children.

PubMed Central

Matson, J L; Sevin, J A; Box, M L; Francis, K L; Sevin, B M

1993-01-01

Three children with autism and mental retardation were treated for deficits in self-initiated speech. A novel treatment package employing visual cue fading was compared with a graduated time-delay procedure previously shown to be effective for increasing self-initiated language. Both treatments included training multiple self-initiated verbalizations using multiple therapists and settings. Both treatments were effective, with no differences in measures of acquisition of target phrases, maintenance of behavioral gains, acquisition with additional therapists and settings, and social validity. PMID:8407687

Is size the only determinant of delayed abdominal closure in pediatric liver transplant?

PubMed

Khorsandi, Shirin Elizabeth; Day, Arthur William Raven; Cortes, Miriam; Deep, Akash; Dhawan, Anil; Vilca-Melendez, Hector; Heaton, Nigel

2017-03-01

The aim was to determine the factors associated with the use of delayed abdominal closure in pediatric liver transplantation (LT) and whether this affected outcome. From a prospectively maintained database, transplants performed in children (≤18 years) were identified (October 2010 to March 2015). Primary abdominal closure was defined as mass closure performed at time of transplant. Delayed abdominal closure was defined as mass closure not initially performed at the same time as transplant; 230 children underwent LT. Of these, 176 (76.5%) had primary closure. Age was similar between the primary and delayed groups (5.0 ± 4.9 versus 3.9 ± 5.0 years; P = 0.13). There was no difference in the graft-to-recipient weight ratio (GRWR) in the primary and delayed groups (3.4 ± 2.8 versus 4.1 ± 2.1; P = 0.12). Children with acute liver failure (ALF) were more likely to experience delayed closure then those with chronic liver disease (CLD; P < 0.001). GRWR was similar between the ALF and CLD (3.4 ± 2.4 versus 3.6 ± 2.7; P = 0.68). Primary closure children had a shorter hospital stay (P < 0.001), spent fewer days in pediatric intensive care unit (PICU; P = 0.001), and required a shorter duration of ventilation (P < 0.001). Vascular complications (arterial and venous) were similar (primary 8.2% versus delayed 5.6%; P = 0.52). Graft (P = 0.42) and child survival (P = 0.65) in the primary and delayed groups were similar. Considering timing of mass closure after transplant, patients in the early delayed closure group (<6 weeks) were found to experience a shorter time of ventilation (P = 0.03) and in PICU (P = 0.003). In conclusion, ALF was the main determinant of delayed abdominal closure rather than GRWR. The optimal time for delayed closure is within 6 weeks. The use of delayed abdominal closure does not adversely affect graft/child survival. Liver Transplantation 23 352-360 2017 AASLD. © 2016 by the American Association for the Study of Liver Diseases.

Same-day antiretroviral therapy (ART) initiation in pregnancy is not associated with viral suppression or engagement in care: A cohort study.

PubMed

Langwenya, Nontokozo; Phillips, Tamsin K; Brittain, Kirsty; Zerbe, Allison; Abrams, Elaine J; Myer, Landon

2018-06-01

Many prevention of mother-to-child HIV transmission programmes across Africa initiate HIV-infected (HIV positive) pregnant women on lifelong antiretroviral therapy (ART) on the first day of antenatal care ("same-day" initiation). However, there are concerns that same-day initiation may limit patient preparation before starting ART and contribute to subsequent non-adherence, disengagement from care and raised viral load. We examined if same-day initiation was associated with viral suppression and engagement in care during pregnancy. Consecutive ART-eligible pregnant women making their first antenatal care (ANC) visit at a primary care facility in Cape Town, South Africa were enrolled into a prospective cohort between March 2013 and June 2014. Before July 2013, ART eligibility was based on CD4 cell count ≤350 cells/μL ("Option A"), with a 1 to 2 week delay from the first ANC visit to ART initiation for patient preparation; thereafter all women were eligible regardless of CD4 cell count ("Option B+") and offered ART on the same day as first ANC visit. Women were followed with viral load testing conducted separately from routine ART services, and engagement in ART services was measured using routinely collected clinic, pharmacy and laboratory records through 12 months postpartum. Among 628 HIV-positive women (median age, 28 years; median gestation at ART start, 21 weeks; 55% newly diagnosed with HIV), 73% initiated ART same-day; this proportion was higher under Option B+ versus Option A (85% vs. 20%). Levels of viral suppression (viral load <50 copies/mL) at delivery (74% vs. 82%) and 12 months postpartum (74% vs. 71%) were similar under same-day versus delayed initiation respectively. Findings were consistent when viral suppression was defined at <1000 copies/mL, after adjustment for demographic/clinical measures and across subgroups of age, CD4 and timing of HIV diagnosis. Time to first viral rebound following initial suppression did not differ by timing of ART initiation nor did engagement in care through 12 months postpartum (same-day = 73%, delayed = 73%, p = 0.910). These data suggest that same-day ART initiation during pregnancy is not associated with lower levels of engagement in care or viral suppression through 12 months post-delivery in this setting, providing reassurance to ART programmes implementing Option B+. © 2018 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.

Immediate versus delayed self-reporting of symptoms and side effects during chemotherapy: does timing matter?

PubMed

Coolbrandt, Annemarie; Van den Heede, Koen; Vanhove, Ellen; De Bom, Ann; Milisen, Koen; Wildiers, Hans

2011-04-01

The aim of this study was to examine how patients recall symptoms at a delayed self-report. Accurate insight into toxicity symptoms during chemotherapy is essential so that nurses and doctors can assess therapeutic tolerance and adjust supportive care accordingly. A non-experimental, longitudinal design was employed. Using the Therapy-Related Symptoms Checklist (TRSC), respondents (n = 142) reported their initial symptoms during the first 7 days of the chemotherapy cycle at two different times: (1) each day of the first seven days after the chemotherapy administration (immediate self-report), and (2) at their next hospital visit for chemotherapy (delayed self-report). We compared the number and severity of symptoms and side effects reported in the immediate and delayed self-reports. Respondents reported significantly fewer symptoms and fewer severe symptoms in the delayed self-report. For 22 out of 25 symptoms the delayed-reported grade was significantly lower than the immediate-reported maximum grade. Compared to the immediate-reported median grade, significant differences occurred in only 10 out of the 25 symptoms. In all cases, except fatigue, the delayed-reported grade was significantly higher than the immediate-reported median grade. This study indicates that delayed self-report of chemotherapy side effects is not an appropriate measure of actual symptoms and side effects experienced by patients. Delayed self-report gives a weaker insight into actual symptom burden. Fatigue is at particular risk to be minimized at the delayed self-report. Therefore it is recommended to assess chemotherapy-related symptoms and side effects by means of immediate self-report. Copyright © 2010 Elsevier Ltd. All rights reserved.

Decisions in Motion: Decision Dynamics during Intertemporal Choice reflect Subjective Evaluation of Delayed Rewards

NASA Astrophysics Data System (ADS)

O'Hora, Denis; Carey, Rachel; Kervick, Aoife; Crowley, David; Dabrowski, Maciej

2016-02-01

People tend to discount rewards or losses that occur in the future. Such delay discounting has been linked to many behavioral and health problems, since people choose smaller short-term gains over greater long-term gains. We investigated whether the effect of delays on the subjective value of rewards is expressed in how people move when they make choices. Over 600 patrons of the RISK LAB exhibition hosted by the Science Gallery DublinTM played a short computer game in which they used a computer mouse to choose between amounts of money at various delays. Typical discounting effects were observed and decision dynamics indicated that choosing smaller short-term rewards became easier (i.e., shorter response times, tighter trajectories, less vacillation) as the delays until later rewards increased. Based on a sequence of choices, subjective values of delayed outcomes were estimated and decision dynamics during initial choices predicted these values. Decision dynamics are affected by subjective values of available options and thus provide a means to estimate such values.

The Effects of Methylphenidate on Discounting of Delayed Rewards in ADHD

PubMed Central

Shiels, Keri; Hawk, Larry W.; Reynolds, Brady; Mazzullo, Rebecca; Rhodes, Jessica; Pelham, William E.; Waxmonsky, James G.; Gangloff, Brian P.

2010-01-01

Impulsivity is a central component of attention-deficit/hyperactivity disorder (ADHD). Delay discounting, or a preference for smaller, immediate rewards over larger, delayed rewards is considered an important aspect of impulsivity, and delay-related impulsivity has been emphasized in etiological models of ADHD. The current study examined whether stimulant medication, an effective treatment for ADHD, reduces discounting of delayed experiential and hypothetical rewards among 49 children (age 9–12 years) with ADHD. Following a practice day, participants completed a 3-day double-blind placebo-controlled acute medication assessment. Active doses were long-acting methylphenidate (Concerta), with the nearest equivalents of 0.3 and 0.6 mg/kg TID immediate-release methylphenidate. On each testing day, participants completed experiential (real-world money in real time) and hypothetical discounting tasks. Relative to placebo, methylphenidate reduced discounting of delayed experiential rewards, but not hypothetical rewards. Broadly consistent with etiological models that emphasize delay-related impulsivity among children with ADHD, these findings provide initial evidence that stimulant medication reduces delay discounting among those with the disorder. The present results also draw attention to task parameters that may influence the sensitivity of various delay discounting measures to medication effects. PMID:19803628

"Work ethic" in pigeons: reward value is directly related to the effort or time required to obtain the reward.

PubMed

Clement, T S; Feltus, J R; Kaiser, D H; Zentall, T R

2000-03-01

Stimuli associated with less effort or with shorter delays to reinforcement are generally preferred over those associated with greater effort or longer delays to reinforcement. However, the opposite appears to be true of stimuli that follow greater effort or longer delays. In training, a simple simultaneous discrimination followed a single peck to an initial stimulus (S+FR1 S-FR1) and a different simple simultaneous discrimination followed 20 pecks to the initial stimulus (S+FR20 S-FR20). On test trials, pigeons preferred S+FR20 over S+FR1 and S-FR20 over S-FR1. These data support the view that the state of the animal immediately prior to presentation of the discrimination affects the value of the reinforcement that follows it. This contrast effect is analogous to effects that when they occur in humans have been attributed to more complex cognitive and social factors.

Classifying epileptic EEG signals with delay permutation entropy and Multi-Scale K-means.

PubMed

Zhu, Guohun; Li, Yan; Wen, Peng Paul; Wang, Shuaifang

2015-01-01

Most epileptic EEG classification algorithms are supervised and require large training datasets, that hinder their use in real time applications. This chapter proposes an unsupervised Multi-Scale K-means (MSK-means) MSK-means algorithm to distinguish epileptic EEG signals and identify epileptic zones. The random initialization of the K-means algorithm can lead to wrong clusters. Based on the characteristics of EEGs, the MSK-means MSK-means algorithm initializes the coarse-scale centroid of a cluster with a suitable scale factor. In this chapter, the MSK-means algorithm is proved theoretically superior to the K-means algorithm on efficiency. In addition, three classifiers: the K-means, MSK-means MSK-means and support vector machine (SVM), are used to identify seizure and localize epileptogenic zone using delay permutation entropy features. The experimental results demonstrate that identifying seizure with the MSK-means algorithm and delay permutation entropy achieves 4. 7 % higher accuracy than that of K-means, and 0. 7 % higher accuracy than that of the SVM.

Delay in the Diagnosis of Adult-Onset Still’s Disease

PubMed Central

Pham, Cindy

2017-01-01

Adult-onset Still’s disease (AOSD) is a systemic autoinflammatory disease characterized by symptoms including spiking fever, arthralgia, myalgia, maculopapular rash, and pharyngitis. The lack of diagnostic biomarker, non-specific clinical presentation, and the rarity of AOSD often result in a significant delay in diagnosis and treatment. While the average time of initial presentation to diagnosis is four months, we present a case of AOSD diagnosis three years after initial onset of classical symptoms. By reporting the case of delayed diagnosis for AOSD, we hope to raise awareness in our medical community about the diagnostic difficulty in AOSD. The present case describes an otherwise healthy male who presented with typical symptoms of AOSD, but the diagnosis of AOSD was missed during his first presentation. In the second flaring episode, the diagnosis of AOSD was established. He had an excellent therapeutic response to anakinra and prednisone during the acute flaring episode. He is currently in complete remission on methotrexate as maintenance therapy. PMID:28690954

Enhancement of the NMSU Channel Error Simulator to Provide User-Selectable Link Delays

NASA Technical Reports Server (NTRS)

Horan, Stephen; Wang, Ru-Hai

2000-01-01

This is the third in a continuing series of reports describing the development of the Space-to-Ground Link Simulator (SGLS) to be used for testing data transfers under simulated space channel conditions. The SGLS is based upon Virtual Instrument (VI) software techniques for managing the error generation, link data rate configuration, and, now, selection of the link delay value. In this report we detail the changes that needed to be made to the SGLS VI configuration to permit link delays to be added to the basic error generation and link data rate control capabilities. This was accomplished by modifying the rate-splitting VIs to include a buffer the hold the incoming data for the duration selected by the user to emulate the channel link delay. In sample tests of this configuration, the TCP/IP(sub ftp) service and the SCPS(sub fp) service were used to transmit 10-KB data files using both symmetric (both forward and return links set to 115200 bps) and unsymmetric (forward link set at 2400 bps and a return link set at 115200 bps) link configurations. Transmission times were recorded at bit error rates of 0 through 10(exp -5) to give an indication of the link performance. In these tests. we noted separate timings for the protocol setup time to initiate the file transfer and the variation in the actual file transfer time caused by channel errors. Both protocols showed similar performance to that seen earlier for the symmetric and unsymmetric channels. This time, the delays in establishing the file protocol also showed that these delays could double the transmission time and need to be accounted for in mission planning. Both protocols also showed a difficulty in transmitting large data files over large link delays. In these tests, there was no clear favorite between the TCP/IP(sub ftp) and the SCPS(sub fp). Based upon these tests, further testing is recommended to extend the results to different file transfer configurations.

Doubly tagged delayed-choice tunable quantum eraser: coherence, information and measurement

NASA Astrophysics Data System (ADS)

Imran, Muhammad; Tariq, Hinna; Rameez-ul-Islam; Ikram, Manzoor

2018-01-01

We present an idea for the doubly tagged delayed-choice tunable quantum eraser in a cavity QED setup, based on fully controlled resonant as well as dispersive atom-field interactions. Two cavity fields, bound initially in the Bell state, are coupled to a three-level atom. Such an atom is initially prepared in the coherent superposition of the lower two levels and is quite capable of exhibiting Ramsey fringes if taken independently. It is shown that the coherence lost due to tagging can not only be retrieved but that the fringe visibility/path distinguishability can also be conditionally tuned in a delayed manner through local manipulation of the entangled cavity fields. The stringent condition here is the retainment of the system’s coherence during successive manipulations of the individual cavity fields. Such a quantum eraser, therefore, prominently highlights the links among all the counterintuitive features of quantum theory including the conception of time, measurement, state vector reduction, coherence and information in an unambiguous manner. The schematics can be straightforwardly extended to a multipartite scenario and employed to explore multi-player quantum games with the payoff being strangely decided through delayed choice setups.

Management of giant omphaloceles: A systematic review of methods of staged surgical vs. nonoperative delayed closure.

PubMed

Bauman, Brent; Stephens, Daniel; Gershone, Hannah; Bongiorno, Connie; Osterholm, Erin; Acton, Robert; Hess, Donavon; Saltzman, Daniel; Segura, Bradley

2016-10-01

Despite the numerous methods of closure for giant omphaloceles, uncertainty persists regarding the most effective option. Our purpose was to review the literature to clarify the current methods being used and to determine superiority of either staged surgical procedures or nonoperative delayed closure in order to recommend a standard of care for the management of the giant omphalocele. Our initial database search resulted in 378 articles. After de-duplification and review, we requested 32 articles relevant to our topic that partially met our inclusion criteria. We found that 14 articles met our criteria; these 14 studies were included in our analysis. 10 studies met the inclusion criteria for nonoperative delayed closure, and 4 studies met the inclusion criteria for staged surgical management. Numerous methods for managing giant omphaloceles have been described. Many studies use topical therapy secondarily to failed surgical management. Primary nonoperative delayed management had a cumulative mortality of 21.8% vs. 23.4% in the staged surgical group. Time to initiation of full enteric feedings was lower in the nonoperative delayed group at 14.6days vs 23.5days. Despite advances in medical and surgical therapies, giant omphaloceles are still associated with a high mortality rate and numerous morbidities. In our analysis, we found that nonoperative delayed management with silver therapy was associated with lower mortality and shorter duration to full enteric feeding. We recommend that nonoperative delayed management be utilized as the primary therapy for the newborn with a giant omphalocele. Copyright © 2016. Published by Elsevier Inc.

Successful tocolysis: does cervical change affect time to delivery?

PubMed

Lewis, D F; Gallaspy, J W; Fontenot, M T; Burlison, R D; Imseis, J M; Edwards, M S

1997-11-01

Generally, it is preferable to tocolyze patients with idiopathic preterm labor (PTL). Little information is available about ultimate outcomes after successful tocolysis. Our objective is to evaluate the relationship between cervical change after the initiation of tocolysis and the delay in time to delivery in patients with preterm labor. A historical analysis of all patients with successful tocolysis after PTL between January 1992 and December 1993 was undertaken. The patients were then placed in one of three categories (regression, unchanged, or progression) based on cervical change after the initiation of tocolysis. Various demographic pregnancy characteristics and pregnancy outcome data were analyzed. One hundred and twenty-six patients had successful tocolysis and met the admission criteria. Patients who had cervical progression had shorter delay to delivery, delivered at an earlier gestational age (31.7 weeks compared to 34.0 and 34.1 weeks, respectively, p < 0.05), and were more likely to deliver before 35 weeks (88% compared to 50.0 and 55.0%, respectively, p < 0.05). Also, neonates remained in the hospital longer and were more likely to have respiratory distress syndrome when compared to the other two groups. Patients who had cervical progression after the initiation of tocolysis are more likely to deliver prematurely, had a shorter delay to delivery, and delivered lower birth weight infants than did patients whose cervix regressed or remained unchanged. In our population, patients who had successful tocolysis had a preterm delivery rate of 59.5% before the 35th week of gestation.

Initial postmarketing experience with crotalidae polyvalent immune Fab for treatment of rattlesnake envenomation.

PubMed

Ruha, Anne-Michelle; Curry, Steven C; Beuhler, Michael; Katz, Ken; Brooks, Daniel E; Graeme, Kimberlie A; Wallace, Kevin; Gerkin, Richard; Lovecchio, Frank; Wax, Paul; Selden, Brad

2002-06-01

We describe our postmarketing experience with patients receiving Crotalidae polyvalent immune Fab (CroFab; FabAV) antivenom for treatment of rattlesnake envenomation. The charts of 28 patients admitted between March 1 and September 9, 2001, with rattlesnake envenomation and treated with FabAV were reviewed for demographic information, time until antivenom treatment, laboratory findings, evidence of hypersensitivity reaction, length of hospital stay, and readmission to the hospital. All patients had swelling, 20 patients had elevated prothrombin times (>14 seconds), 12 patients had low fibrinogen levels (<170 mg/dL), and 6 patients had thrombocytopenia (platelet count <120,000/mm(3)) on presentation. The total dose of FabAV ranged from 10 to 47 vials per patient. Hypofibrinogenemia was resistant to FabAV in some patients. On follow-up, recurrence of coagulopathy was detected in 3 patients, and recurrence of thrombocytopenia was detected in 1 patient. Two patients demonstrated delayed-onset severe thrombocytopenia. Recurrence or delayed-onset toxicity might have been underestimated because of incomplete follow-up in some patients. No acute hypersensitivity reactions occurred. Two patients reported mild symptoms of possible serum sickness on follow-up. FabAV effectively controlled the effects of envenomation; however, initial control of coagulopathy was difficult to achieve in some cases, and recurrence or delayed-onset hematotoxicity was common. When initially managing hematotoxicity, a trend toward normalization of laboratory values might be a more reasonable end point for FabAV treatment than attainment of normal reference values in nonbleeding patients.

Clinical presentation of retinoblastoma in Alexandria: A step toward earlier diagnosis.

PubMed

Soliman, Sameh E; Eldomiaty, Wesam; Goweida, Mohamed B; Dowidar, Amgad

2017-01-01

To evaluate the clinical presentation of retinoblastoma in Alexandria, Egypt, correlate the timing of accurate diagnosis with the presence of advanced disease and identify causes of delayed presentation. Retrospective noncomparative single institution study reviews demographic and clinical data of all new children with retinoblastoma presenting to Alexandria Main University ocular oncology clinic (OOC) from January 2012 to June 2014. Diagnosis time was from initial parental complaint to retinoblastoma diagnosis and referral time was from retinoblastoma diagnosis to presentation to the Alexandria OCC. Delayed Diagnosis and referral were counted if >2 weeks. Advanced presentation is defined as clinical TNMH (8th edition) staging of cT2 or cT3 (international intraocular retinoblastoma classification group D or E) in at least one eye or the presence of extra-ocular disease (cT4). Seventy eyes of 47 children were eligible: 52% unilateral, 7% with family history and 96% presented with leukocorea. Sixty-four percent of children had advanced intraocular disease and none had extra-ocular disease. Delayed presentation occurred in 58% of children and was significantly associated with advanced disease in both unilaterally and bilaterally affected children (p = 0.003, 0.002 respectively). The delay in diagnosis was more in unilateral cases while the delay in referral was more in bilateral cases. The main cause of delayed presentation in unilateral retinoblastoma was misdiagnosis (30%) while parental shopping for second medical opinion (30%) was the main cause in bilateral children. Delayed diagnosis is a problem affecting retinoblastoma management. Better medical education and training, health education and earlier screening are recommended to achieve earlier diagnosis.

The Tradeoff between Travel Time from Home to Hospital and Door to Balloon Time in Determining Mortality among STEMI Patients Undergoing PCI.

PubMed

Di Domenicantonio, Riccardo; Cappai, Giovanna; Sciattella, Paolo; Belleudi, Valeria; Di Martino, Mirko; Agabiti, Nera; Mataloni, Francesca; Ricci, Roberto; Perucci, Carlo Alberto; Davoli, Marina; Fusco, Danilo

2016-01-01

In ST-segment elevation myocardial infarction (STEMI), even in presence of short door to balloon time (DTBT), timely reperfusion with percutaneous coronary intervention (PCI) is hampered by pre-hospital delays. Travel time (TT) constitutes a relevant part of these delays and may contribute to worse outcomes. To evaluate the relationship between TT from home to hospital and DTBT on 30-day mortality after PCI among patients with STEMI. We enrolled a cohort of 3,608 STEMI patients with a DTBT within 120 minutes who underwent PCI between years 2009 and 2013 in Lazio Region (Italy). We calculated the minimum travel time from residential address to emergency department where the first medical contact occurred. We defined system delay as the sum of travel time and DTBT time. Logistic regression models, including clinical and demographic characteristics were used to estimate the effect of TT and DTBT on mortality. Among patients with 0-90 minutes of system delay, TT above the median value is positively associated with mortality (OR = 2.46; P = 0.009). Survival benefit associated with DTBT below the median results only among patients with TT below the median (OR for DTBT below the median = 0.39; P = 0.013), (OR for interaction between TT and DTBT = 2.36; p = 0.076). TT affects survival after PCI for STEMI, even in the presence of health care systems compliant with current guidelines. Results emphasize the importance of health system initiatives to reduce pre-hospital delay. Utilization of TT can contribute to a better estimate of patient mortality risk in the evaluation of quality of care.

Ikeda-like chaos on a dynamically filtered supercontinuum light source

NASA Astrophysics Data System (ADS)

Chembo, Yanne K.; Jacquot, Maxime; Dudley, John M.; Larger, Laurent

2016-08-01

We demonstrate temporal chaos in a color-selection mechanism from the visible spectrum of a supercontinuum light source. The color-selection mechanism is governed by an acousto-optoelectronic nonlinear delayed-feedback scheme modeled by an Ikeda-like equation. Initially motivated by the design of a broad audience live demonstrator in the framework of the International Year of Light 2015, the setup also provides a different experimental tool to investigate the dynamical complexity of delayed-feedback dynamics. Deterministic hyperchaos is analyzed here from the experimental time series. A projection method identifies the delay parameter, for which the chaotic strange attractor originally evolving in an infinite-dimensional phase space can be revealed in a two-dimensional subspace.

Constitutional Delay Influences the Auxological Response to Growth Hormone Treatment in Children with Short Stature and Growth Hormone Sufficiency

PubMed Central

Gunn, Katherine C.; Cutfield, Wayne S.; Hofman, Paul L.; Jefferies, Craig A.; Albert, Benjamin B.; Gunn, Alistair J.

2014-01-01

In a retrospective, population based cohort study, we examined whether constitutional delay was associated with the growth response to growth hormone (GH) in children with short stature and normal GH responses. 70 patients were treated with 21 GH iu/m2/week from 1975 to 2013 throughout New Zealand. Demographic and auxological data were prospectively collected and standard deviation scores (SDS) were calculated for height (HtSDS), yearly growth velocity (GV-SDS), body mass index (BMI-SDS) and predicted adult height (PAH-SDS) at time of the last available bone age. In the first year, GH was associated with marked increase in HtSDS (+0.46 (0.19, 0.76), p < 0.001) and GV-SDS (from −1.9 (−3.6, −0.7) to +2.7 (0.45, 4.2), p < 0.001). The increase in HtSDS but not in GV-SDS was greatest with younger patients and greater bone age delay, with no effect of sex, BMI-SDS or baseline HtSDS. PAH-SDS increased with treatment (+0.94 (0.18, 1.5)); increased PAH-SDS was associated with less bone age delay and greater initial increase in HtSDS. This study shows that greater bone age delay was associated with greater initial improvement in height but less improvement in predicted adult heights, suggesting that children with very delayed bone ages may show accelerated maturation during GH treatment. PMID:25317732

Constitutional delay influences the auxological response to growth hormone treatment in children with short stature and growth hormone sufficiency.

PubMed

Gunn, Katherine C; Cutfield, Wayne S; Hofman, Paul L; Jefferies, Craig A; Albert, Benjamin B; Gunn, Alistair J

2014-08-14

In a retrospective, population based cohort study, we examined whether constitutional delay was associated with the growth response to growth hormone (GH) in children with short stature and normal GH responses. 70 patients were treated with 21 GH iu/m2/week from 1975 to 2013 throughout New Zealand. Demographic and auxological data were prospectively collected and standard deviation scores (SDS) were calculated for height (HtSDS), yearly growth velocity (GV-SDS), body mass index (BMI-SDS) and predicted adult height (PAH-SDS) at time of the last available bone age. In the first year, GH was associated with marked increase in HtSDS (+0.46 (0.19, 0.76), p < 0.001) and GV-SDS (from -1.9 (-3.6, -0.7) to +2.7 (0.45, 4.2), p < 0.001). The increase in HtSDS but not in GV-SDS was greatest with younger patients and greater bone age delay, with no effect of sex, BMI-SDS or baseline HtSDS. PAH-SDS increased with treatment (+0.94 (0.18, 1.5)); increased PAH-SDS was associated with less bone age delay and greater initial increase in HtSDS. This study shows that greater bone age delay was associated with greater initial improvement in height but less improvement in predicted adult heights, suggesting that children with very delayed bone ages may show accelerated maturation during GH treatment.

Cost-effectiveness analysis of interferon beta-1b for the treatment of patients with a first clinical event suggestive of multiple sclerosis.

PubMed

Caloyeras, John P; Zhang, Bin; Wang, Cheng; Eriksson, Marianne; Fredrikson, Sten; Beckmann, Karola; Knappertz, Volker; Pohl, Christoph; Hartung, Hans-Peter; Shah, Dhvani; Miller, Jeffrey D; Sandbrink, Rupert; Lanius, Vivian; Gondek, Kathleen; Russell, Mason W

2012-05-01

To assess, from a Swedish societal perspective, the cost effectiveness of interferon β-1b (IFNB-1b) after an initial clinical event suggestive of multiple sclerosis (MS) (ie, early treatment) compared with treatment after onset of clinically definite MS (CDMS) (ie, delayed treatment). A Markov model was developed, using patient level data from the BENEFIT trial and published literature, to estimate health outcomes and costs associated with IFNB-1b for hypothetical cohorts of patients after an initial clinical event suggestive of MS. Health states were defined by Kurtzke Expanded Disability Status Scale (EDSS) scores. Model outcomes included quality-adjusted life years (QALYs), total costs (including both direct and indirect costs), and incremental cost-effectiveness ratios. Sensitivity analyses were performed on key model parameters to assess the robustness of model results. In the base case scenario, early IFNB-1b treatment was economically dominant (ie, less costly and more effective) versus delayed IFNB-1b treatment when QALYs were used as the effectiveness metric. Sensitivity analyses showed that the cost-effectiveness results were sensitive to model time horizon. Compared with the delayed treatment strategy, early treatment of MS was also associated with delayed EDSS progressions, prolonged time to CDMS diagnosis, and a reduction in frequency of relapse. Early treatment with IFNB-1b for a first clinical event suggestive of MS was found to improve patient outcomes while controlling costs. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

Parathyroid cryopreservation following parathyroidectomy: a worthwhile practice?

PubMed Central

Shepet, Kevin; Alhefdhi, Amal; Usedom, Reid; Sippel, Rebecca; Chen, Herbert

2013-01-01

Background Parathyroid cryopreservation is often utilized for patients having parathyroidectomy. This allows for future autotransplantation if a patient becomes permanently hypocalcemic after surgery. However, the practice of cryopreservation is costly and time consuming, while the success rate of delayed autotransplantation is highly variable. We sought to determine the rate and outcomes of parathyroid cryopreservation and delayed autotransplantation at our institution to further evaluate its utility. Methods At our institution, 2,083 parathyroidectomies for hyperparathyroidism (HPT) were performed from 2001–2010. Of these, parathyroid cryopreservation was utilized in 442 patients (21%). Patient demographics, preoperative diagnoses, and other characteristics were analyzed, as well as the rate and success of delayed autotransplantation. Results Of the 442 patients with cryopreservation, the mean age was 55 ± 1 years and 313 (70.8%) were female. 308 (70%) had primary HPT, 46 (10%) had secondary HPT, and 88 (20%) had tertiary HPT. Delayed autotransplantation of cryopreserved parathyroid tissue was used in 4 (1%) patients at an average time of 9 ± 4 months after initial surgery. 3 out of the 4 patients remained hypoparathyroid following this procedure. The one cured patient underwent the procedure only 4 days following the initial parathyroidectomy. Conclusion While cryopreservation was used in over 1/5 of patients undergoing parathyroidectomy, the need for parathyroid reimplantation was very low (1%). Furthermore, the success rate of parathyroid autotransplantation was poor in these patients. Therefore, the continued practice of parathyroid cryopreservation is questionable. PMID:23504122

Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.

PubMed

Menu, Frédéric; Ginoux, Marine; Rajon, Etienne; Lazzari, Claudio R; Rabinovich, Jorge E

2010-05-25

The developmental time of vector insects is important in population dynamics, evolutionary biology, epidemiology and in their responses to global climatic change. In the triatomines (Triatominae, Reduviidae), vectors of Chagas disease, evolutionary ecology concepts, which may allow for a better understanding of their biology, have not been applied. Despite delay in the molting in some individuals observed in triatomines, no effort was made to explain this variability. We applied four methods: (1) an e-mail survey sent to 30 researchers with experience in triatomines, (2) a statistical description of the developmental time of eleven triatomine species, (3) a relationship between development time pattern and climatic inter-annual variability, (4) a mathematical optimization model of evolution of developmental delay (diapause). 85.6% of responses informed on prolonged developmental times in 5(th) instar nymphs, with 20 species identified with remarkable developmental delays. The developmental time analysis showed some degree of bi-modal pattern of the development time of the 5(th) instars in nine out of eleven species but no trend between development time pattern and climatic inter-annual variability was observed. Our optimization model predicts that the developmental delays could be due to an adaptive risk-spreading diapause strategy, only if survival throughout the diapause period and the probability of random occurrence of "bad" environmental conditions are sufficiently high. Developmental delay may not be a simple non-adaptive phenotypic plasticity in development time, and could be a form of adaptive diapause associated to a physiological mechanism related to the postponement of the initiation of reproduction, as an adaptation to environmental stochasticity through a spreading of risk (bet-hedging) strategy. We identify a series of parameters that can be measured in the field and laboratory to test this hypothesis. The importance of these findings is discussed in terms of global climatic change and epidemiological consequences.

CHANGES IN PATELLOFEMORAL JOINT STRESS DURING RUNNING WITH THE APPLICATION OF A PREFABRICATED FOOT ORTHOTIC.

PubMed

Almonroeder, Thomas G; Benson, Lauren C; O'Connor, Kristian M

2015-12-01

Foot orthotics are commonly utilized in the treatment of patellofemoral pain (PFP) and have shown clinical benefit; however, their mechanism of action remains unclear. Patellofemoral joint stress (PFJS) is thought to be one of the main etiological factors associated with PFP. The primary purpose of this study was to investigate the effects of a prefabricated foot orthotic with 5 ° of medial rearfoot wedging on the magnitude and the timing of the peak PFJS in a group of healthy female recreational athletes. The hypothesis was that there would be significant reduction in the peak patellofemoral joint stress and a delay in the timing of this peak in the orthotic condition. Cross-sectional. Kinematic and kinetic data were collected during running trials in a group of healthy, female recreational athletes. The knee angle and moment data in the sagittal plane were incorporated into a previously developed model to estimate patellofemoral joint stress. The dependent variables of interest were the peak patellofemoral joint stress as well as the percentage of stance at which this peak occurred, as both the magnitude and the timing of the joint loading are thought to be important in overuse running injuries. The peak patellofemoral joint stress significantly increased in the orthotic condition by 5.8% (p=.02, ES=0.24), which does not support the initial hypothesis. However, the orthotic did significantly delay the timing of the peak during the stance phase by 3.8% (p=.002, ES=0.47). The finding that the peak patellofemoral joint stress increased in the orthotic condition did not support the initial hypothesis. However, the finding that the timing of this peak was delayed to later in the stance phase in the orthotic condition did support the initial hypothesis and may be related to the clinical improvements previously reported in subjects with PFP. Level 4.

Rapid ambiguity resolution over medium-to-long baselines based on GPS/BDS multi-frequency observables

NASA Astrophysics Data System (ADS)

Gong, Xiaopeng; Lou, Yidong; Liu, Wanke; Zheng, Fu; Gu, Shengfeng; Wang, Hua

2017-02-01

Medium-long baseline RTK positioning generally needs a long initial time to find an accurate position due to non-negligible atmospheric delay residual. In order to shorten the initial or re-convergence time, a rapid phase ambiguity resolution method is employed based on GPS/BDS multi-frequency observables in this paper. This method is realized by two steps. First, double-differenced un-combined observables (i.e., L1/L2 and B1/B2/B3 observables) are used to obtain a float solution with atmospheric delay estimated as random walk parameter by using Kalman filter. This model enables an easy and consistent implementation for different systems and different frequency observables and can readily be extended to use more satellite navigation systems (e.g., Galileo, QZSS). Additional prior constraints for atmospheric information can be quickly added as well, because atmospheric delay is parameterized. Second, in order to fix ambiguity rapidly and reliably, ambiguities are divided into three types (extra-wide-lane (EWL), wide-lane (WL) and narrow-lane (NL)) according to their wavelengths and are to be fixed sequentially by using the LAMBDA method. Several baselines ranging from 61 km to 232 km collected by Trimble and Panda receivers are used to validate the method. The results illustrate that it only takes approximately 1, 2 and 6 epochs (30 s intervals) to fix EWL, WL and NL ambiguities, respectively. More epochs' observables are needed to fix WL and NL ambiguity around local time 14:00 than other time mainly due to more active ionosphere activity. As for the re-convergence time, the simulated results show that 90% of epochs can be fixed within 2 epochs by using prior atmospheric delay information obtained from previously 5 min. Finally, as for positioning accuracy, meter, decimeter and centimeter level positioning results are obtained according to different ambiguity resolution performances, i.e., EWL, WL and NL fixed solutions.

The time-delay signature of quark-gluon plasma formation in relativistic nuclear collisions

NASA Astrophysics Data System (ADS)

Rischke, Dirk H.; Gyulassy, Miklos

1996-02-01

The hydrodynamic expansion of quark-gluon plasmas with spherical and longitudinally boost-invariant geometries is studied as a function of the initial energy density. The sensitivity of the collective flow pattern to uncertainties in the nuclear matter equation of state is explored. We concentrate on the effect of a possible finite width, ΔT ˜ 0.1 Tc, of the transition region between quark-gluon plasma and hadronic phase. Although slow deflagration solutions that act to stall the expansion do not exist for ΔT > 0.08 Tc, we find, nevertheless, that the equation of state remains sufficiently soft in the transition region to delay the propagation of ordinary rarefaction waves for a considerable time. We compute the dependence of the pion-interferometry correlation function on ΔT, since this is the most promising observable for time-delayed expansion. The signature of time delay, proposed by Pratt and Bertsch, is an enhancement of the ratio of the inverse width of the pion correlation function in out-direction to that in side-direction. One of our main results is that this generic signature of quark-gluon plasma formation is rather robust to the uncertainties in the width of the transition region. Furthermore, for longitudinal boost-invariant geometries, the signal is likely to be maximized around RHIC energies

Absorption dynamics and delay time in complex potentials

NASA Astrophysics Data System (ADS)

Villavicencio, Jorge; Romo, Roberto; Hernández-Maldonado, Alberto

2018-05-01

The dynamics of absorption is analyzed by using an exactly solvable model that deals with an analytical solution to Schrödinger’s equation for cutoff initial plane waves incident on a complex absorbing potential. A dynamical absorption coefficient which allows us to explore the dynamical loss of particles from the transient to the stationary regime is derived. We find that the absorption process is characterized by the emission of a series of damped periodic pulses in time domain, associated with damped Rabi-type oscillations with a characteristic frequency, ω = (E + ε)/ℏ, where E is the energy of the incident waves and ‑ε is energy of the quasidiscrete state of the system induced by the absorptive part of the Hamiltonian; the width γ of this resonance governs the amplitude of the pulses. The resemblance of the time-dependent absorption coefficient with a real decay process is discussed, in particular the transition from exponential to nonexponential regimes, a well-known feature of quantum decay. We have also analyzed the effect of the absorptive part of the potential on the dynamical delay time, which behaves differently from the one observed in attractive real delta potentials, exhibiting two regimes: time advance and time delay.

Effect of the RC time on photocurrent transients and determination of charge carrier mobilities

NASA Astrophysics Data System (ADS)

Kniepert, Juliane; Neher, Dieter

2017-11-01

We present a closed analytical model to describe time dependent photocurrents upon pulsed illumination in the presence of an external RC circuit. In combination with numerical drift diffusion simulations, it is shown that the RC time has a severe influence on the shape of the transients. In particular, the maximum of the photocurrent is delayed due to a delayed recharging of the electrodes. This delay increases with the increasing RC constant. As a consequence, charge carrier mobilities determined from simple extrapolation of the initial photocurrent decay will be in general too small and feature a false dependence on the electric field. Here, we present a recipe to correct charge carrier mobilities determined from measured photocurrent transients by taking into account the RC time of the experimental set-up. We also demonstrate how the model can be used to more reliably determine the charge carrier mobility from experimental data of a typical polymer/fullerene organic solar cell. It is shown that further aspects like a finite rising time of the pulse generator and the current contribution of the slower charger carriers influence the shape of the transients and may lead to an additional underestimation of the transit time.

Earlier reperfusion in patients with ST-elevation Myocardial infarction by use of helicopter

PubMed Central

2012-01-01

Background In patients with ST-elevation myocardial infarction (STEMI) reperfusion therapy should be initiated as soon as possible. This study evaluated whether use of a helicopter for transportation of patients is associated with earlier initiation of reperfusion therapy. Material and methods A prospective study was conducted, including patients with STEMI and symptom duration less than 12 hours, who had primary percutaneous coronary intervention (PPCI) performed at Aarhus University Hospital in Skejby. Patients with a health care system delay (time from emergency call to first coronary intervention) of more than 360 minutes were excluded. The study period ran from 1.1.2011 until 31.12.2011. A Western Denmark Helicopter Emergency Medical Service (HEMS) project was initiated 1.6.2011 for transportation of patients with time-critical illnesses, including STEMI. Results The study population comprised 398 patients, of whom 376 were transported by ambulance Emergency Medical Service (EMS) and 22 by HEMS. Field-triage directly to the PCI-center was used in 338 of patients. The median system delay was 94 minutes among those field-triaged, and 168 minutes among those initially admitted to a local hospital. Patients transported by EMS and field-triaged were stratified into four groups according to transport distance from the scene of event to the PCI-center: ≤25 km., 26–50 km., 51–75 km. and > 75 km. For these groups, the median system delay was 78, 89, 99, and 141 minutes. Among patients transported by HEMS and field-triaged the estimated median transport distance by ground transportation was 115 km, and the observed system delay was 107 minutes. Based on second order polynomial regression, it was estimated that patients with a transport distance of >60 km to the PCI-center may benefit from helicopter transportation, and that transportation by helicopter is associated with a system delay of less than 120 minutes even at a transport distance up to 150 km. Conclusion The present study indicates that use of a helicopter should be considered for field-triage of patients with STEMI to the PCI-center in case of long transportation. Such a strategy may ensure that patients living up to 150 km. from the PCI-center can be treated within 120 minutes of emergency call. PMID:23036101

Earlier reperfusion in patients with ST-elevation myocardial infarction by use of helicopter.

PubMed

Knudsen, Lars; Stengaard, Carsten; Hansen, Troels Martin; Lassen, Jens Flensted; Terkelsen, Christian Juhl

2012-10-04

In patients with ST-elevation myocardial infarction (STEMI) reperfusion therapy should be initiated as soon as possible. This study evaluated whether use of a helicopter for transportation of patients is associated with earlier initiation of reperfusion therapy. A prospective study was conducted, including patients with STEMI and symptom duration less than 12 hours, who had primary percutaneous coronary intervention (PPCI) performed at Aarhus University Hospital in Skejby. Patients with a health care system delay (time from emergency call to first coronary intervention) of more than 360 minutes were excluded. The study period ran from 1.1.2011 until 31.12.2011. A Western Denmark Helicopter Emergency Medical Service (HEMS) project was initiated 1.6.2011 for transportation of patients with time-critical illnesses, including STEMI. The study population comprised 398 patients, of whom 376 were transported by ambulance Emergency Medical Service (EMS) and 22 by HEMS. Field-triage directly to the PCI-center was used in 338 of patients. The median system delay was 94 minutes among those field-triaged, and 168 minutes among those initially admitted to a local hospital. Patients transported by EMS and field-triaged were stratified into four groups according to transport distance from the scene of event to the PCI-center: ≤25 km., 26-50 km., 51-75 km. and > 75 km. For these groups, the median system delay was 78, 89, 99, and 141 minutes. Among patients transported by HEMS and field-triaged the estimated median transport distance by ground transportation was 115 km, and the observed system delay was 107 minutes. Based on second order polynomial regression, it was estimated that patients with a transport distance of >60 km to the PCI-center may benefit from helicopter transportation, and that transportation by helicopter is associated with a system delay of less than 120 minutes even at a transport distance up to 150 km. The present study indicates that use of a helicopter should be considered for field-triage of patients with STEMI to the PCI-center in case of long transportation. Such a strategy may ensure that patients living up to 150 km. from the PCI-center can be treated within 120 minutes of emergency call.

Reducing Communication Delays and Improving Quality of Care with a Tuberculosis Laboratory Information System in Resource Poor Environments: A Cluster Randomized Controlled Trial

PubMed Central

Blaya, Joaquín A.; Shin, Sonya S.; Yagui, Martin; Contreras, Carmen; Cegielski, Peter; Yale, Gloria; Suarez, Carmen; Asencios, Luis; Bayona, Jaime; Kim, Jihoon; Fraser, Hamish S. F.

2014-01-01

Background Lost, delayed or incorrect laboratory results are associated with delays in initiating treatment. Delays in treatment for Multi-Drug Resistant Tuberculosis (MDR-TB) can worsen patient outcomes and increase transmission. The objective of this study was to evaluate the impact of a laboratory information system in reducing delays and the time for MDR-TB patients to culture convert (stop transmitting). Methods Setting: 78 primary Health Centers (HCs) in Lima, Peru. Participants lived within the catchment area of participating HCs and had at least one MDR-TB risk factor. The study design was a cluster randomized controlled trial with baseline data. The intervention was the e-Chasqui web-based laboratory information system. Main outcome measures were: times to communicate a result; to start or change a patient's treatment; and for that patient to culture convert. Results 1671 patients were enrolled. Intervention HCs took significantly less time to receive drug susceptibility test (DST) (median 11 vs. 17 days, Hazard Ratio 0.67 [0.62–0.72]) and culture (5 vs. 8 days, 0.68 [0.65–0.72]) results. The time to treatment was not significantly different, but patients in intervention HCs took 16 days (20%) less time to culture convert (p = 0.047). Conclusions The eChasqui system reduced the time to communicate results between laboratories and HCs and time to culture conversion. It is now used in over 259 HCs covering 4.1 million people. This is the first randomized controlled trial of a laboratory information system in a developing country for any disease and the only study worldwide to show clinical impact of such a system. Trial Registration ClinicalTrials.gov NCT01201941 PMID:24721980

Reducing communication delays and improving quality of care with a tuberculosis laboratory information system in resource poor environments: a cluster randomized controlled trial.

PubMed

Blaya, Joaquín A; Shin, Sonya S; Yagui, Martin; Contreras, Carmen; Cegielski, Peter; Yale, Gloria; Suarez, Carmen; Asencios, Luis; Bayona, Jaime; Kim, Jihoon; Fraser, Hamish S F

2014-01-01

Lost, delayed or incorrect laboratory results are associated with delays in initiating treatment. Delays in treatment for Multi-Drug Resistant Tuberculosis (MDR-TB) can worsen patient outcomes and increase transmission. The objective of this study was to evaluate the impact of a laboratory information system in reducing delays and the time for MDR-TB patients to culture convert (stop transmitting). 78 primary Health Centers (HCs) in Lima, Peru. Participants lived within the catchment area of participating HCs and had at least one MDR-TB risk factor. The study design was a cluster randomized controlled trial with baseline data. The intervention was the e-Chasqui web-based laboratory information system. Main outcome measures were: times to communicate a result; to start or change a patient's treatment; and for that patient to culture convert. 1671 patients were enrolled. Intervention HCs took significantly less time to receive drug susceptibility test (DST) (median 11 vs. 17 days, Hazard Ratio 0.67 [0.62-0.72]) and culture (5 vs. 8 days, 0.68 [0.65-0.72]) results. The time to treatment was not significantly different, but patients in intervention HCs took 16 days (20%) less time to culture convert (p = 0.047). The eChasqui system reduced the time to communicate results between laboratories and HCs and time to culture conversion. It is now used in over 259 HCs covering 4.1 million people. This is the first randomized controlled trial of a laboratory information system in a developing country for any disease and the only study worldwide to show clinical impact of such a system. ClinicalTrials.gov NCT01201941.

Assessment of Appalachian region pediatric hearing healthcare disparities and delays.

PubMed

Bush, Matthew L; Osetinsky, Mariel; Shinn, Jennifer B; Gal, Thomas J; Ding, Xiuhua; Fardo, David W; Schoenberg, Nancy

2014-07-01

The purpose of this study was to examine the timing of diagnostic and therapeutic services in cochlear implant recipients from a rural Appalachian region with healthcare disparity. Retrospective analysis. Cochlear implant recipients from a tertiary referral center born with severe congenital sensorineural hearing loss were examined. Rural status and Appalachian status of their county of origin were recorded. A log-rank test was used to examine differences in the distributions of time to definitive diagnosis of hearing loss, initial amplification fitting, and cochlear implantation in these children. Correlation analysis of the rural status of each county and the timing of services was assessed. A total of 53 children born with congenital hearing loss were included in the study (36 from rural counties and 17 from urban/suburban counties). The distribution of weeks after birth to diagnosis (P=.006), amplification (P=.030), and cochlear implantation (P=.002) was delayed in rural children compared with urban children. An analysis factoring in the effect of implementation of mandatory infant hearing screening in 2000 demonstrated a similar delay in rural children for weeks to diagnosis (P=.028), amplification (P=.087), and cochlear implantation (P<.0001). Children with severe hearing loss in very rural areas, such as Appalachia, may have significant delays in diagnostic and rehabilitative services. Further investigation is warranted to assess causative factors in delays of cochlear implantation and to develop interventions to promote timely diagnosis and care. 3b. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Vulnerability to paroxysmal oscillations in delayed neural networks: A basis for nocturnal frontal lobe epilepsy?

NASA Astrophysics Data System (ADS)

Quan, Austin; Osorio, Ivan; Ohira, Toru; Milton, John

2011-12-01

Resonance can occur in bistable dynamical systems due to the interplay between noise and delay (τ) in the absence of a periodic input. We investigate resonance in a two-neuron model with mutual time-delayed inhibitory feedback. For appropriate choices of the parameters and inputs three fixed-point attractors co-exist: two are stable and one is unstable. In the absence of noise, delay-induced transient oscillations (referred to herein as DITOs) arise whenever the initial function is tuned sufficiently close to the unstable fixed-point. In the presence of noisy perturbations, DITOs arise spontaneously. Since the correlation time for the stationary dynamics is ˜τ, we approximated a higher order Markov process by a three-state Markov chain model by rescaling time as t → 2sτ, identifying the states based on whether the sub-intervals were completely confined to one basin of attraction (the two stable attractors) or straddled the separatrix, and then determining the transition probability matrix empirically. The resultant Markov chain model captured the switching behaviors including the statistical properties of the DITOs. Our observations indicate that time-delayed and noisy bistable dynamical systems are prone to generate DITOs as switches between the two attractors occur. Bistable systems arise transiently in situations when one attractor is gradually replaced by another. This may explain, for example, why seizures in certain epileptic syndromes tend to occur as sleep stages change.

The impact of postoperative expansion initiation timing on breast expander capsular characteristics: a prospective combined clinical and scanning electron microscopy study.

PubMed

Paek, Laurence S; Giot, Jean-Philippe; Tétreault-Paquin, Jean-Olivier; St-Jacques, Samuel; Nelea, Monica; Danino, M Alain

2015-04-01

In the first stage of expander-to-implant breast reconstruction, postoperative expansion is classically initiated at 10 to 14 days (conventional approach). The authors hypothesized that it may be beneficial to wait 6 weeks postoperatively before initiating serial expansion (delayed approach). Clinical and ultrastructural periprosthetic capsule analysis is first required before determining whether a delayed approach ultimately improves capsular tissue adherence and expansion process predictability. Patients undergoing two-stage implant-based breast reconstruction were enrolled prospectively in this study. During expander-to-implant exchange, the clinical presence of "Velcro" effect, biofilm, and double capsule was noted. Periprosthetic capsule samples were also sent for scanning electron microscopic observation of three parameters: surface relief, cellularity, and biofilm. Samples were divided into four groups for data analysis (group 1, conventional/Biocell; group 2, delayed/Biocell; group 3, conventional/Siltex; and group 4, delayed/Siltex). Fifty-six breast reconstructions were included. Each group comprised between 13 and 15 breasts. In group 1, no cases exhibited the Velcro effect and there was a 53.8 percent incidence of both biofilm and double capsule. In group 2, all cases demonstrated the Velcro effect and there were no incidences of biofilm or double capsule. Group 3 and group 4 cases did not exhibit a Velcro effect or double-capsule formation; however, biofilm was present in up to 20.0 percent. All group 2 samples revealed more pronounced three-dimensional relief on scanning electron microscopy. Variations in expansion protocols can lead to observable modifications in periprosthetic capsular architecture. There may be real benefits to delaying expander inflation until 6 weeks postoperatively with Biocell expanders.

Propagation and spatiotemporal coupling characteristics of ultra-short Gaussian vortex pulse

NASA Astrophysics Data System (ADS)

Nie, Jianye; Liu, Guodong; Zhang, Rongzhu

2018-05-01

Based on Collins diffraction integral formula, the propagation equation of ultra-short Gaussian vortex pulse beam has been derived. Using the equation, the intensity distribution variations of vortex pulse in the propagation process are calculated. Specially, the spatiotemporal coupling characteristics of ultra-short vortex beams are discussed in detail. The results show that some key parameters, such as transverse distance, transmission distance, pulse width and topological charge number will influence the spatiotemporal coupling characteristics significantly. With the increasing of transverse distance, the waveforms of the pulses distort obviously. And when transmission distance is far than 50 mm, the distribution curve of transverse intensity gradually changes into a Gaussian type. In addition, initial pulse width will affect the distribution of light field, however, when initial pulse width is larger than 3 fs, the spatiotemporal coupling effect will be insignificant. Topological charge number does not affect the time delay characteristics, since with the increasing of topological charge number, the waveform of the pulse distorts gradually but the time delay does not occur.

Training Rapid Stepping Responses in an Individual With Stroke

PubMed Central

Inness, Elizabeth L.; Komar, Janice; Biasin, Louis; Brunton, Karen; Lakhani, Bimal; McIlroy, William E.

2011-01-01

Background and Purpose Compensatory stepping reactions are important responses to prevent a fall following a postural perturbation. People with hemiparesis following a stroke show delayed initiation and execution of stepping reactions and often are found to be unable to initiate these steps with the more-affected limb. This case report describes a targeted training program involving repeated postural perturbations to improve control of compensatory stepping in an individual with stroke. Case Description Compensatory stepping reactions of a 68-year-old man were examined 52 days after left hemorrhagic stroke. He required assistance to prevent a fall in all trials administered during his initial examination because he showed weight-bearing asymmetry (with more weight borne on the more-affected right side), was unable to initiate stepping with the right leg (despite blocking of the left leg in some trials), and demonstrated delayed response times. The patient completed 6 perturbation training sessions (30–60 minutes per session) that aimed to improve preperturbation weight-bearing symmetry, to encourage stepping with the right limb, and to reduce step initiation and completion times. Outcomes Improved efficacy of compensatory stepping reactions with training and reduced reliance on assistance to prevent falling were observed. Improvements were noted in preperturbation asymmetry and step timing. Blocking the left foot was effective in encouraging stepping with the more-affected right foot. Discussion This case report demonstrates potential short-term adaptations in compensatory stepping reactions following perturbation training in an individual with stroke. Future work should investigate the links between improved compensatory step characteristics and fall risk in this vulnerable population. PMID:21511992

Photonic integrated circuits unveil crisis-induced intermittency.

PubMed

Karsaklian Dal Bosco, Andreas; Akizawa, Yasuhiro; Kanno, Kazutaka; Uchida, Atsushi; Harayama, Takahisa; Yoshimura, Kazuyuki

2016-09-19

We experimentally investigate an intermittent route to chaos in a photonic integrated circuit consisting of a semiconductor laser with time-delayed optical feedback from a short external cavity. The transition from a period-doubling dynamics to a fully-developed chaos reveals a stage intermittently exhibiting these two dynamics. We unveil the bifurcation mechanism underlying this route to chaos by using the Lang-Kobayashi model and demonstrate that the process is based on a phenomenon of attractor expansion initiated by a particular distribution of the local Lyapunov exponents. We emphasize on the crucial importance of the distribution of the steady-state solutions introduced by the time-delayed feedback on the existence of this intermittent dynamics.

Benefit Assessment of the Precision Departure Release Capability Concept

NASA Technical Reports Server (NTRS)

Palopo, Kee; Chatterji, Gano B.; Lee, Hak-Tae

2011-01-01

A Precision Departure Release Capability concept is being evaluated by both the National Aeronautics and Space Administration and the Federal Aviation Administration as part of a larger goal of improving throughput, efficiency and capacity in integrated departure, arrival and surface operations. The concept is believed to have the potential of increasing flight efficiency and throughput by avoiding missing assigned slots and minimizing speed increase or path stretch to recover the slot. The main thrust of the paper is determining the impact of early and late departures from the departure runway when an aircraft has a slot assigned either at a meter fix or at the arrival airport. Results reported in the paper are for two scenarios. The first scenario considers flights out of Dallas/Fort Worth destined for Hartsfield-Jackson International Airport in Atlanta flying through the Meridian meter-fix in the Memphis Center with miles-in-trail constraints. The second scenario considers flights destined to George Bush Intercontinental/Houston Airport with specified airport arrival rate constraint. Results show that delay reduction can be achieved by allowing reasonable speed changes in scheduling. It was determined that the traffic volume between Dallas/Fort Worth and Atlanta via the Meridian fix is low and the departures times are spread enough that large departure schedule uncertainty can be tolerated. Flights can depart early or late within 90 minutes without accruing much more delay due to miles-in-trail constraint at the Meridian fix. In the Houston scenario, 808 arrivals from 174 airports were considered. Results show that delay experienced by the 16 Dallas/Fort Worth departures is higher if initial schedules of the remaining 792 flights are kept unaltered while they are rescheduled. Analysis shows that the probability of getting the initially assigned slot back after perturbation and rescheduling decreases with increasing standard deviation of the departure delay distributions. Results show that most Houston arrivals can be expected to be on time based on the assumed zero-mean Normal departure delay distributions achievable by Precision Departure Release Capability. In the current system, airport-departure delay, which is the sum of gate-departure delay and taxi-out delay, is observed at the airports. This delay acts as a bias, which can be reduced by Precision Departure Release Capability.

Human-in-the-Loop Operations over Time Delay: NASA Analog Missions Lessons Learned

NASA Technical Reports Server (NTRS)

Rader, Steven N.; Reagan, Marcum L.; Janoiko, Barbara; Johnson, James E.

2013-01-01

Teams at NASA have conducted studies of time-delayed communications as it effects human exploration. In October 2012, the Advanced Exploration Systems (AES) Analog Missions project conducted a Technical Interchange Meeting (TIM) with the primary stakeholders to share information and experiences of studying time delay, to build a coherent picture of how studies are covering the problem domain, and to determine possible forward plans (including how to best communicate study results and lessons learned, how to inform future studies and mission plans, and how to drive potential development efforts). This initial meeting s participants included personnel from multiple NASA centers (HQ, JSC, KSC, ARC, and JPL), academia, and ESA. It included all of the known studies, analog missions, and tests of time delayed communications dating back to the Apollo missions including NASA Extreme Environment Mission Operations (NEEMO), Desert Research and Technology Studies (DRATS/RATS), International Space Station Test-bed for Analog Research (ISTAR), Pavilion Lake Research Project (PLRP), Mars 520, JPL Mars Orbiters/Rovers, Advanced Mission Operations (AMO), Devon Island analog missions, and Apollo experiences. Additionally, the meeting attempted to capture all of the various functional perspectives via presentations by disciplines including mission operations (flight director and mission planning), communications, crew, Capcom, Extra-Vehicular Activity (EVA), Behavioral Health and Performance (BHP), Medical/Surgeon, Science, Education and Public Outreach (EPO), and data management. The paper summarizes the descriptions and results from each of the activities discussed at the TIM and includes several recommendations captured in the meeting for dealing with time delay in human exploration along with recommendations for future development and studies to address this issue.

Identification of educational and infrastructural barriers to prompt antibiotic delivery in febrile neutropenia: a quality improvement initiative.

PubMed

Burry, Erica; Punnett, Angela; Mehta, Ashley; Thull-Freedman, Jennifer; Robinson, Lisa; Gupta, Sumit

2012-09-01

Antibiotic administration within 60 minutes of presentation for medical care may be used as a treatment target for febrile neutropenia (FN); however, anecdotal evidence suggests this target is often missed. Few studies have examined the prevalence or causes of delay. We describe the median time to antibiotic administration at our institution, predictors of delay, and barriers to prompt administration to inform quality improvement strategies. A random sample of 50 episodes of FN presenting to the emergency department (ED) between 2008 and 2009 were reviewed. Times between triage, MD assessment, lab results, and antibiotic administration were recorded. Patient and ED variables were examined as possible predictors of delay. In parallel, lean methodology was used to identify system inefficiencies. A trained moderator conducted group interviews with interdisciplinary representatives involved in the emergency care of neutropenic patients to identify process barriers to prompt antibiotics. The median time from triage to antibiotics was 216 minutes (interquartile range [IQR] = 151-274 minutes). The greatest delay occurred following the reporting of lab results (152 minutes, IQR = 84-210 minutes). Only fall season predicted a longer time to antibiotics (P = 0.03). The lean process identified unnecessary areas of delay between departments. Time to antibiotic administration exceeded 1 hour. The chart review and lean process suggested targets for educational and infrastructural interventions, including an ED pre-printed order sheet, targeted combined subspecialty education between emergency and hematology/oncology staff, and family education. A mixed methodology approach represents a model for improving process efficiency and meeting "best-practice" targets in medicine. Copyright © 2011 Wiley Periodicals, Inc.

Strong Lens Time Delay Challenge. I. Experimental Design

NASA Astrophysics Data System (ADS)

Dobler, Gregory; Fassnacht, Christopher D.; Treu, Tommaso; Marshall, Phil; Liao, Kai; Hojjati, Alireza; Linder, Eric; Rumbaugh, Nicholas

2015-02-01

The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters. The number of lenses with measured time delays is growing rapidly; the upcoming Large Synoptic Survey Telescope (LSST) will monitor ~103 strongly lensed quasars. In an effort to assess the present capabilities of the community, to accurately measure the time delays, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we have invited the community to take part in a "Time Delay Challenge" (TDC). The challenge is organized as a set of "ladders," each containing a group of simulated data sets to be analyzed blindly by participating teams. Each rung on a ladder consists of a set of realistic mock observed lensed quasar light curves, with the rungs' data sets increasing in complexity and realism. The initial challenge described here has two ladders, TDC0 and TDC1. TDC0 has a small number of data sets, and is designed to be used as a practice set by the participating teams. The (non-mandatory) deadline for completion of TDC0 was the TDC1 launch date, 2013 December 1. The TDC1 deadline was 2014 July 1. Here we give an overview of the challenge, we introduce a set of metrics that will be used to quantify the goodness of fit, efficiency, precision, and accuracy of the algorithms, and we present the results of TDC0. Thirteen teams participated in TDC0 using 47 different methods. Seven of those teams qualified for TDC1, which is described in the companion paper.

The role of health system factors in delaying final diagnosis and treatment of breast cancer in Mexico City, Mexico.

PubMed

Bright, Kristin; Barghash, Maya; Donach, Martin; de la Barrera, Marcos Gutiérrez; Schneider, Robert J; Formenti, Silvia C

2011-04-01

In Mexico, breast cancer is the leading cancer-related death among women and most cases are diagnosed at advanced stages (50-60%). We hypothesized health system factors could be partly responsible for this delay and performed a prospective review of 166 new breast cases at a major public hospital in Mexico City. Our analysis confirmed the prevalence of locally advanced and metastatic disease (47% of patients). A subset analysis of 32 women with confirmed stage I-IIIC breast cancer found an average time interval of 1.8 months from symptom onset to first primary care consultation (PCC), with an additional 6.6 months from first PCC to confirmed diagnosis, and 0.6 months from diagnosis to treatment initiation. Patients underwent an average of 7.9 clinic visits before confirmed diagnosis. Findings suggest that protracted referral time from primary to specialty care accounts for the bulk of delay, with earlier stage patients experiencing longer delays. These findings reveal a critical need for further study and exploration of interventions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Diagnostic pathways and direct medical costs incurred by new adult pulmonary tuberculosis patients prior to anti-tuberculosis treatment – Tamil Nadu, India

PubMed Central

Veesa, Karun Sandeep; John, Kamalabhai Russell; Moonan, Patrick K.; Kaliappan, Saravanakumar Puthupalayam; Manjunath, Krishna; Sagili, Karuna D.; Ravichandra, Chinnappareddy; Menon, Pradeep Aravindan; Dolla, Chandrakumar; Luke, Nancy; Munshi, Kaivan; George, Kuryan; Minz, Shantidani

2018-01-01

Background Tuberculosis (TB) patients face substantial delays prior to treatment initiation, and out of pocket (OOP) expenditures often surpass the economic productivity of the household. We evaluated the pre-diagnostic cost and health seeking behaviour of new adult pulmonary TB patients registered at Primary Health Centres (PHCs) in Vellore district, Tamil Nadu, India. Methods This descriptive study, part of a randomised controlled trial conducted in three rural Tuberculosis Units from Dec 2012 to Dec 2015, collected data on number of health facilities, dates of visits prior to the initiation of anti-tuberculosis treatment, and direct OOP medical costs associated with TB diagnosis. Logistic regression analysis examined the factors associated with delays in treatment initiation and OOP expenditures. Results Of 880 TB patients interviewed, 34.7% presented to public health facilities and 65% patients sought private health facilities as their first point of care. The average monthly individual income was $77.79 (SD 57.14). About 69% incurred some pre-treatment costs at an average of $39.74. Overall, patients experienced a median of 6 days (3–11 IQR) of time to treatment initiation and 21 days (10–30 IQR) of health systems delay. Age ≤ 40 years (aOR: 1.73; CI: 1.22–2.44), diabetes (aOR: 1.63; CI: 1.08–2.44) and first visit to a private health facility (aOR: 17.2; CI: 11.1–26.4) were associated with higher direct OOP medical costs, while age ≤ 40 years (aOR: 0.64; CI: 0.48–0.85) and first visit to private health facility (aOR: 1.79, CI: 1.34–2.39) were associated with health systems delay. Conclusion The majority of rural TB patients registering at PHCs visited private health facilities first and incurred substantial direct OOP medical costs and delays prior to diagnosis and anti-tuberculosis treatment initiation. This study highlights the need for PHCs to be made as the preferred choice for first point of contact, to combat TB more efficiently. PMID:29414980

Diagnostic pathways and direct medical costs incurred by new adult pulmonary tuberculosis patients prior to anti-tuberculosis treatment - Tamil Nadu, India.

PubMed

Veesa, Karun Sandeep; John, Kamalabhai Russell; Moonan, Patrick K; Kaliappan, Saravanakumar Puthupalayam; Manjunath, Krishna; Sagili, Karuna D; Ravichandra, Chinnappareddy; Menon, Pradeep Aravindan; Dolla, Chandrakumar; Luke, Nancy; Munshi, Kaivan; George, Kuryan; Minz, Shantidani

2018-01-01

Tuberculosis (TB) patients face substantial delays prior to treatment initiation, and out of pocket (OOP) expenditures often surpass the economic productivity of the household. We evaluated the pre-diagnostic cost and health seeking behaviour of new adult pulmonary TB patients registered at Primary Health Centres (PHCs) in Vellore district, Tamil Nadu, India. This descriptive study, part of a randomised controlled trial conducted in three rural Tuberculosis Units from Dec 2012 to Dec 2015, collected data on number of health facilities, dates of visits prior to the initiation of anti-tuberculosis treatment, and direct OOP medical costs associated with TB diagnosis. Logistic regression analysis examined the factors associated with delays in treatment initiation and OOP expenditures. Of 880 TB patients interviewed, 34.7% presented to public health facilities and 65% patients sought private health facilities as their first point of care. The average monthly individual income was $77.79 (SD 57.14). About 69% incurred some pre-treatment costs at an average of $39.74. Overall, patients experienced a median of 6 days (3-11 IQR) of time to treatment initiation and 21 days (10-30 IQR) of health systems delay. Age ≤ 40 years (aOR: 1.73; CI: 1.22-2.44), diabetes (aOR: 1.63; CI: 1.08-2.44) and first visit to a private health facility (aOR: 17.2; CI: 11.1-26.4) were associated with higher direct OOP medical costs, while age ≤ 40 years (aOR: 0.64; CI: 0.48-0.85) and first visit to private health facility (aOR: 1.79, CI: 1.34-2.39) were associated with health systems delay. The majority of rural TB patients registering at PHCs visited private health facilities first and incurred substantial direct OOP medical costs and delays prior to diagnosis and anti-tuberculosis treatment initiation. This study highlights the need for PHCs to be made as the preferred choice for first point of contact, to combat TB more efficiently.

Influence of cutting time on brush response: implications for herbivory in linear (transportation) corridors.

PubMed

Rea, Roy V; Child, Kenneth N; Spata, David P; MacDonald, Douglas

2007-08-01

An experiment was conducted to determine the influence the time of brush-cutting can have on plant regrowth and attractiveness to herbivores that browse in linear corridors. The influence of cutting time on leaf flush and senescence, shoot morphometry, and biomass was measured for 3 consecutive years after initial brush-cutting. Results indicate that morphological and phenological attributes of three woody deciduous plants were influenced by the timing of brush-cutting for up to 3 years after initial cutting. Brush-cutting generally stimulated plants to produce larger than normal shoots and delay leaf senescence. The degree to which plants were affected, however, varied with the timing of initial cutting and the species in question. Generally, plants cut later in the year resprouted more vigorously and were taller in the third year after cutting but produced less overall biomass than when cut earlier. In the years following brush-cutting, plants cut earlier flushed leaves earlier in the spring but delayed leaf senescence in the fall when compared to uncut controls. Results of these trials suggest that brush-cutting time influences plant response and several plant attributes known to influence plant attractiveness to moose and other herbivores. We therefore recommend that roadside and railside vegetation management plans consider the influence of cutting time on plant regrowth. Such considerations can ensure that brush is cut to reduce the attractiveness of plant regrowth in these linear corridors, reduce the utilization of such brush by herbivores, and, as such, mitigate collision risk between motorists and herbivores such as moose.

Patients with RA in remission on TNF blockers: when and in whom can TNF blocker therapy be stopped?

PubMed

Saleem, Benazir; Keen, Helen; Goeb, Vincent; Parmar, Rekha; Nizam, Sharmin; Hensor, Elizabeth M A; Churchman, Sarah M; Quinn, Mark; Wakefield, Richard; Conaghan, Philip G; Ponchel, Frederique; Emery, Paul

2010-09-01

Combination therapy with methotrexate (MTX) and tumour necrosis factor (TNF) blockade has increased remission rates in patients with rheumatoid arthritis. However, there are no guidelines regarding cessation of therapy. There is a need for markers predictive of sustained remission following cessation of TNF blocker therapy. Patients in remission (DAS28 <2.6) treated with a TNF blocker and MTX as initial or delayed therapy were recruited. Joints were assessed for grey scale synovitis and power Doppler (PD) activity. Immunological assessment involved advanced six-colour flow cytometry. Of the 47 patients recruited, 27 had received initial treatment and 20 delayed treatment with TNF blocking drugs. Two years after stopping TNF blocker therapy, the main predictor of successful cessation was timing of treatment; 59% of patients in the initial treatment group sustained remission compared with 15% in the delayed treatment group (p=0.003). Within the initial treatment group, secondary analysis showed that the only clinical predictor of successful cessation of treatment was shorter symptom duration before receiving treatment (median 5.5 months vs 9 months; p=0.008). No other clinical features were associated with successful cessation of therapy. Thirty-five per cent of patients had low PD activity but levels were not informative. Several immunological parameters were significantly associated with sustained remission including abnormal differentiation subset of T cells and regulatory T cells. Similar non-significant trends were observed in the delayed treatment group. In patients in remission with low levels of imaging synovitis receiving combination treatment with a TNF blocker and MTX, immunological parameters and short duration of untreated symptoms were associated with successful cessation of TNF blocker therapy.

External fixation combined with delayed internal fixation in treatment of tibial plateau fractures with dislocation

PubMed Central

Tao, Xingguang; Chen, Nong; Pan, Fugen; Cheng, Biao

2017-01-01

Abstract The aim of this study was to evaluate the clinical efficacy of external fixation, delayed open reduction, and internal fixation in treating tibial plateau fracture with dislocation. Clinical data of 34 patients diagnosed with tibial plateau fracture complicated with dislocation between January 2009 and May 2015 were retrospectively analyzed. Fifteen patients in group A underwent early calcaneus traction combined with open reduction and internal fixation and 19 in group B received early external fixation combined with delayed open reduction and internal fixation. Operation time, postoperative complication, bone healing time, knee joint range of motion, initial weight-bearing time, Rasmussen tibial plateau score, and knee function score (HSS) were statistically compared between 2 groups. The mean follow-up time was 18.6 months (range: 5–24 months). The mean operation time in group A was 96 minutes, significantly longer than 71 minutes in group B (P < .05). In group A, 5 cases had postoperative complications and 1 in group B (P < .05). The mean bone healing time in group A was 6.9 months (range: 5–9 months) and 6.0 months (range: 5–8 months) in group B (P > .05). In group A, initial weight-bearing time in group A was (14.0 ± 3.6) weeks, significantly differing from (12.9 ± 2.8) weeks in group B (P < 0.05). In group A, the mean knee joint range of motion was 122° (range: 95°–150°) and 135° (range: 100°–160°) in group B (P > 0.05). Rasmussen tibial plateau score in group A was slightly lower than that in group B (P > .05). The excellent rate of knee joint function in group A was 80% and 84.21% in group B (P > .05). External fixation combined with delayed open reduction and internal fixation is a safer and more efficacious therapy of tibial plateau fracture complicated with dislocation compared with early calcaneus traction and open reduction and internal fixation. PMID:29019890

External fixation combined with delayed internal fixation in treatment of tibial plateau fractures with dislocation.

PubMed

Tao, Xingguang; Chen, Nong; Pan, Fugen; Cheng, Biao

2017-10-01

The aim of this study was to evaluate the clinical efficacy of external fixation, delayed open reduction, and internal fixation in treating tibial plateau fracture with dislocation.Clinical data of 34 patients diagnosed with tibial plateau fracture complicated with dislocation between January 2009 and May 2015 were retrospectively analyzed. Fifteen patients in group A underwent early calcaneus traction combined with open reduction and internal fixation and 19 in group B received early external fixation combined with delayed open reduction and internal fixation. Operation time, postoperative complication, bone healing time, knee joint range of motion, initial weight-bearing time, Rasmussen tibial plateau score, and knee function score (HSS) were statistically compared between 2 groups.The mean follow-up time was 18.6 months (range: 5-24 months). The mean operation time in group A was 96 minutes, significantly longer than 71 minutes in group B (P < .05). In group A, 5 cases had postoperative complications and 1 in group B (P < .05). The mean bone healing time in group A was 6.9 months (range: 5-9 months) and 6.0 months (range: 5-8 months) in group B (P > .05). In group A, initial weight-bearing time in group A was (14.0 ± 3.6) weeks, significantly differing from (12.9 ± 2.8) weeks in group B (P < 0.05). In group A, the mean knee joint range of motion was 122° (range: 95°-150°) and 135° (range: 100°-160°) in group B (P > 0.05). Rasmussen tibial plateau score in group A was slightly lower than that in group B (P > .05). The excellent rate of knee joint function in group A was 80% and 84.21% in group B (P > .05).External fixation combined with delayed open reduction and internal fixation is a safer and more efficacious therapy of tibial plateau fracture complicated with dislocation compared with early calcaneus traction and open reduction and internal fixation.

Why wait? The social determinants underlying tuberculosis diagnostic delay

PubMed Central

Saunders, Matthew James; Zegarra, Roberto; Evans, Carlton; Alegria-Flores, Kei; Guio, Heinner

2017-01-01

Background Early detection and diagnosis of tuberculosis remain major global priorities for tuberculosis control. Few studies have used a qualitative approach to investigate the social determinants contributing to diagnostic delay and none have compared data collected from individual, community, and health-system levels. We aimed to characterize the social determinants that contribute to diagnostic delay among persons diagnosed with tuberculosis living in resource-constrained settings. Methods/Principle findings Data were collected in public health facilities with high tuberculosis incidence in 19 districts of Lima, Peru. Semi-structured interviews with persons diagnosed with tuberculosis (n = 105) and their family members (n = 63) explored health-seeking behaviours, community perceptions of tuberculosis and socio-demographic circumstances. Focus groups (n = 6) were conducted with health personnel (n = 35) working in the National Tuberculosis Program. All interview data were transcribed and analysed using a grounded theory approach. The median delay between symptom onset and the public health facility visit that led to the first positive diagnostic sample was 57 days (interquartile range 28–126). The great majority of persons diagnosed with tuberculosis distrusted the public health system and sought care at public health facilities only after exhausting other options. It was universally agreed that persons diagnosed with tuberculosis faced discrimination by public and health personnel. Self-medication with medicines bought at local pharmacies was reported as the most common initial health-seeking behaviour due to the speed and low-cost of treatment in pharmacies. Most persons diagnosed with tuberculosis initially perceived their illness as a simple virus. Conclusions Diagnostic delay was common and prolonged. When individuals reached a threshold of symptom severity, they addressed their health with the least time-consuming, most economically feasible, and well-known healthcare option available to them. In high-burden settings, more human and material resources are required to promote tuberculosis case-finding initiatives, reduce tuberculosis associated stigma and address the social determinants underlying diagnostic delay. PMID:28945782

Why wait? The social determinants underlying tuberculosis diagnostic delay.

PubMed

Bonadonna, Lily Victoria; Saunders, Matthew James; Zegarra, Roberto; Evans, Carlton; Alegria-Flores, Kei; Guio, Heinner

2017-01-01

Early detection and diagnosis of tuberculosis remain major global priorities for tuberculosis control. Few studies have used a qualitative approach to investigate the social determinants contributing to diagnostic delay and none have compared data collected from individual, community, and health-system levels. We aimed to characterize the social determinants that contribute to diagnostic delay among persons diagnosed with tuberculosis living in resource-constrained settings. Data were collected in public health facilities with high tuberculosis incidence in 19 districts of Lima, Peru. Semi-structured interviews with persons diagnosed with tuberculosis (n = 105) and their family members (n = 63) explored health-seeking behaviours, community perceptions of tuberculosis and socio-demographic circumstances. Focus groups (n = 6) were conducted with health personnel (n = 35) working in the National Tuberculosis Program. All interview data were transcribed and analysed using a grounded theory approach. The median delay between symptom onset and the public health facility visit that led to the first positive diagnostic sample was 57 days (interquartile range 28-126). The great majority of persons diagnosed with tuberculosis distrusted the public health system and sought care at public health facilities only after exhausting other options. It was universally agreed that persons diagnosed with tuberculosis faced discrimination by public and health personnel. Self-medication with medicines bought at local pharmacies was reported as the most common initial health-seeking behaviour due to the speed and low-cost of treatment in pharmacies. Most persons diagnosed with tuberculosis initially perceived their illness as a simple virus. Diagnostic delay was common and prolonged. When individuals reached a threshold of symptom severity, they addressed their health with the least time-consuming, most economically feasible, and well-known healthcare option available to them. In high-burden settings, more human and material resources are required to promote tuberculosis case-finding initiatives, reduce tuberculosis associated stigma and address the social determinants underlying diagnostic delay.

Convergence and attractivity of memristor-based cellular neural networks with time delays.

PubMed

Qin, Sitian; Wang, Jun; Xue, Xiaoping

2015-03-01

This paper presents theoretical results on the convergence and attractivity of memristor-based cellular neural networks (MCNNs) with time delays. Based on a realistic memristor model, an MCNN is modeled using a differential inclusion. The essential boundedness of its global solutions is proven. The state of MCNNs is further proven to be convergent to a critical-point set located in saturated region of the activation function, when the initial state locates in a saturated region. It is shown that the state convergence time period is finite and can be quantitatively estimated using given parameters. Furthermore, the positive invariance and attractivity of state in non-saturated regions are also proven. The simulation results of several numerical examples are provided to substantiate the results. Copyright © 2014 Elsevier Ltd. All rights reserved.

High resolution time interval meter

DOEpatents

Martin, A.D.

1986-05-09

Method and apparatus are provided for measuring the time interval between two events to a higher resolution than reliability available from conventional circuits and component. An internal clock pulse is provided at a frequency compatible with conventional component operating frequencies for reliable operation. Lumped constant delay circuits are provided for generating outputs at delay intervals corresponding to the desired high resolution. An initiation START pulse is input to generate first high resolution data. A termination STOP pulse is input to generate second high resolution data. Internal counters count at the low frequency internal clock pulse rate between the START and STOP pulses. The first and second high resolution data are logically combined to directly provide high resolution data to one counter and correct the count in the low resolution counter to obtain a high resolution time interval measurement.

Investigating tunneling process of atom exposed in circularly polarized strong-laser field

NASA Astrophysics Data System (ADS)

Yuan, MingHu; Xin, PeiPei; Chu, TianShu; Liu, HongPing

2017-03-01

We propose a method for studying the tunneling process by analyzing the instantaneous ionization rate of a circularly polarized laser. A numerical calculation shows that, for an atom exposed to a long laser pulse, if its initial electronic state wave function is non-spherical symmetric, the delayed phase shift of the ionization rate vs the laser cycle period in real time in the region close to the peak intensity of the laser pulse can be used to probe the tunneling time. In this region, an obvious time delay phase shift of more than 190 attoseconds is observed. Further study shows that the atom has a longer tunneling time in the ionization under a shorter wavelength laser pulse. In our method, a Wigner rotation technique is employed to numerically solve the time-dependent Schrödinger equation of a single-active electron in a three-dimensional spherical coordinate system.

An energy-efficient MAC protocol using dynamic queue management for delay-tolerant mobile sensor networks.

PubMed

Li, Jie; Li, Qiyue; Qu, Yugui; Zhao, Baohua

2011-01-01

Conventional MAC protocols for wireless sensor network perform poorly when faced with a delay-tolerant mobile network environment. Characterized by a highly dynamic and sparse topology, poor network connectivity as well as data delay-tolerance, delay-tolerant mobile sensor networks exacerbate the severe power constraints and memory limitations of nodes. This paper proposes an energy-efficient MAC protocol using dynamic queue management (EQ-MAC) for power saving and data queue management. Via data transfers initiated by the target sink and the use of a dynamic queue management strategy based on priority, EQ-MAC effectively avoids untargeted transfers, increases the chance of successful data transmission, and makes useful data reach the target terminal in a timely manner. Experimental results show that EQ-MAC has high energy efficiency in comparison with a conventional MAC protocol. It also achieves a 46% decrease in packet drop probability, 79% increase in system throughput, and 25% decrease in mean packet delay.

An Energy-Efficient MAC Protocol Using Dynamic Queue Management for Delay-Tolerant Mobile Sensor Networks

PubMed Central

Li, Jie; Li, Qiyue; Qu, Yugui; Zhao, Baohua

2011-01-01

Conventional MAC protocols for wireless sensor network perform poorly when faced with a delay-tolerant mobile network environment. Characterized by a highly dynamic and sparse topology, poor network connectivity as well as data delay-tolerance, delay-tolerant mobile sensor networks exacerbate the severe power constraints and memory limitations of nodes. This paper proposes an energy-efficient MAC protocol using dynamic queue management (EQ-MAC) for power saving and data queue management. Via data transfers initiated by the target sink and the use of a dynamic queue management strategy based on priority, EQ-MAC effectively avoids untargeted transfers, increases the chance of successful data transmission, and makes useful data reach the target terminal in a timely manner. Experimental results show that EQ-MAC has high energy efficiency in comparison with a conventional MAC protocol. It also achieves a 46% decrease in packet drop probability, 79% increase in system throughput, and 25% decrease in mean packet delay. PMID:22319385

Estimating the state of a geophysical system with sparse observations: time delay methods to achieve accurate initial states for prediction

NASA Astrophysics Data System (ADS)

An, Zhe; Rey, Daniel; Ye, Jingxin; Abarbanel, Henry D. I.

2017-01-01

The problem of forecasting the behavior of a complex dynamical system through analysis of observational time-series data becomes difficult when the system expresses chaotic behavior and the measurements are sparse, in both space and/or time. Despite the fact that this situation is quite typical across many fields, including numerical weather prediction, the issue of whether the available observations are "sufficient" for generating successful forecasts is still not well understood. An analysis by Whartenby et al. (2013) found that in the context of the nonlinear shallow water equations on a β plane, standard nudging techniques require observing approximately 70 % of the full set of state variables. Here we examine the same system using a method introduced by Rey et al. (2014a), which generalizes standard nudging methods to utilize time delayed measurements. We show that in certain circumstances, it provides a sizable reduction in the number of observations required to construct accurate estimates and high-quality predictions. In particular, we find that this estimate of 70 % can be reduced to about 33 % using time delays, and even further if Lagrangian drifter locations are also used as measurements.

Tunable Optical True-Time Delay Devices Would Exploit EIT

NASA Technical Reports Server (NTRS)

Kulikov, Igor; DiDomenico, Leo; Lee, Hwang

2004-01-01

Tunable optical true-time delay devices that would exploit electromagnetically induced transparency (EIT) have been proposed. Relative to prior true-time delay devices (for example, devices based on ferroelectric and ferromagnetic materials) and electronically controlled phase shifters, the proposed devices would offer much greater bandwidths. In a typical envisioned application, an optical pulse would be modulated with an ultra-wideband radio-frequency (RF) signal that would convey the information that one seeks to communicate, and it would be required to couple differently delayed replicas of the RF signal to the radiating elements of a phased-array antenna. One or more of the proposed devices would be used to impose the delays and/or generate the delayed replicas of the RF-modulated optical pulse. The beam radiated or received by the antenna would be steered by use of a microprocessor-based control system that would adjust operational parameters of the devices to tune the delays to the required values. EIT is a nonlinear quantum optical interference effect that enables the propagation of light through an initially opaque medium. A suitable medium must have, among other properties, three quantum states (see Figure 1): an excited state (state 3), an upper ground state (state 2), and a lower ground state (state 1). These three states must form a closed system that exhibits no decays to other states in the presence of either or both of two laser beams: (1) a probe beam having the wavelength corresponding to the photon energy equal to the energy difference between states 3 and 1; and (2) a coupling beam having the wavelength corresponding to the photon energy equal to the energy difference between states 3 and 2. The probe beam is the one that is pulsed and modulated with an RF signal.

Decisions in Motion: Decision Dynamics during Intertemporal Choice reflect Subjective Evaluation of Delayed Rewards

PubMed Central

O’Hora, Denis; Carey, Rachel; Kervick, Aoife; Crowley, David; Dabrowski, Maciej

2016-01-01

People tend to discount rewards or losses that occur in the future. Such delay discounting has been linked to many behavioral and health problems, since people choose smaller short-term gains over greater long-term gains. We investigated whether the effect of delays on the subjective value of rewards is expressed in how people move when they make choices. Over 600 patrons of the RISK LAB exhibition hosted by the Science Gallery DublinTM played a short computer game in which they used a computer mouse to choose between amounts of money at various delays. Typical discounting effects were observed and decision dynamics indicated that choosing smaller short-term rewards became easier (i.e., shorter response times, tighter trajectories, less vacillation) as the delays until later rewards increased. Based on a sequence of choices, subjective values of delayed outcomes were estimated and decision dynamics during initial choices predicted these values. Decision dynamics are affected by subjective values of available options and thus provide a means to estimate such values. PMID:26867497

Immediate Tube Feeding after Percutaneous Endoscopic Gastrostomy: Early Return to Goal Tube Feeds without Added Complications.

PubMed

Lamb, Laura C; Jayaraman, Vijay; Montgomery, Stephanie C; Umer, Affan; Shapiro, David S; Feeney, James M

2017-02-01

Percutaneous endoscopic gastrostomy (PEG) is frequently performed for delivery of nonoral enteral nutrition (EN) in critically ill patients. Tube-based supplement initiation is often delayed for a variety of reasons despite evidence that EN interruption results in worse outcomes. To determine if early initiation of EN after PEG placement is safe and well-tolerated in critically ill patients and if early initiation of EN results in more goal-accomplished days of EN. A retrospective chart review of patients who underwent PEG and at least 24 hours of EN. Patients were stratified according to time to tube- feed initiation: immediate (< one hour), early (one to four hours), and late (four to 24 hours). 'Ihe three groups were similar with respect to demographics, comorbidities, and 30-day mortality. Sixty-one percent of patients in the immediate group were advanced to the previously-met goal EN rates compared to 24% and 18% in the early and delayed groups, respectively (P < .0001). Immediate reinitiation of nonoral EN after PEG procedure is safe and is associated with reaching goal nutrition faster.

Delay in seeking care for tuberculosis symptoms among adults newly diagnosed with HIV in rural Malawi.

PubMed

Ngwira, L G; Dowdy, D W; Khundi, M; Barnes, G L; Nkhoma, A; Choko, A T; Murowa, M; Chaisson, R E; Corbett, E L; Fielding, K

2018-03-01

Ten primary health clinics in rural Thyolo District, Malawi. Tuberculosis (TB) is a common initial presentation of human immunodeficiency virus (HIV) infection. We investigated the time from TB symptom onset to HIV diagnosis to describe TB health-seeking behaviour in adults newly diagnosed with HIV. We asked adults (18 years) about the presence and duration of TB symptoms at the time of receiving a new HIV diagnosis. Associations with delayed health seeking (defined as >30 and >90 days from the onset of TB symptoms) were evaluated using multivariable logistic regression. TB symptoms were reported by 416 of 1265 participants (33%), of whom 36% (150/416) had been symptomatic for >30 days before HIV testing. Most participants (260/416, 63%) were below the poverty line (US$0.41 per household member per day). Patients who first sought care from informal providers had an increased odds of delay of >30 days (adjusted odds ratio [aOR] 1.6, 95%CI 0.9-2.8) or 90 days (aOR 2.0, 95%CI 1.1-3.8). Delayed health seeking for TB-related symptoms was common. Poverty was ubiquitous, but had no clear relationship to diagnostic delay. HIV-positive individuals who first sought care from informal providers were more likely to experience diagnostic delays for TB symptoms.

Stabilizing embedology: Geometry-preserving delay-coordinate maps

NASA Astrophysics Data System (ADS)

Eftekhari, Armin; Yap, Han Lun; Wakin, Michael B.; Rozell, Christopher J.

2018-02-01

Delay-coordinate mapping is an effective and widely used technique for reconstructing and analyzing the dynamics of a nonlinear system based on time-series outputs. The efficacy of delay-coordinate mapping has long been supported by Takens' embedding theorem, which guarantees that delay-coordinate maps use the time-series output to provide a reconstruction of the hidden state space that is a one-to-one embedding of the system's attractor. While this topological guarantee ensures that distinct points in the reconstruction correspond to distinct points in the original state space, it does not characterize the quality of this embedding or illuminate how the specific parameters affect the reconstruction. In this paper, we extend Takens' result by establishing conditions under which delay-coordinate mapping is guaranteed to provide a stable embedding of a system's attractor. Beyond only preserving the attractor topology, a stable embedding preserves the attractor geometry by ensuring that distances between points in the state space are approximately preserved. In particular, we find that delay-coordinate mapping stably embeds an attractor of a dynamical system if the stable rank of the system is large enough to be proportional to the dimension of the attractor. The stable rank reflects the relation between the sampling interval and the number of delays in delay-coordinate mapping. Our theoretical findings give guidance to choosing system parameters, echoing the tradeoff between irrelevancy and redundancy that has been heuristically investigated in the literature. Our initial result is stated for attractors that are smooth submanifolds of Euclidean space, with extensions provided for the case of strange attractors.

Stabilizing embedology: Geometry-preserving delay-coordinate maps.

PubMed

Eftekhari, Armin; Yap, Han Lun; Wakin, Michael B; Rozell, Christopher J

2018-02-01

Delay-coordinate mapping is an effective and widely used technique for reconstructing and analyzing the dynamics of a nonlinear system based on time-series outputs. The efficacy of delay-coordinate mapping has long been supported by Takens' embedding theorem, which guarantees that delay-coordinate maps use the time-series output to provide a reconstruction of the hidden state space that is a one-to-one embedding of the system's attractor. While this topological guarantee ensures that distinct points in the reconstruction correspond to distinct points in the original state space, it does not characterize the quality of this embedding or illuminate how the specific parameters affect the reconstruction. In this paper, we extend Takens' result by establishing conditions under which delay-coordinate mapping is guaranteed to provide a stable embedding of a system's attractor. Beyond only preserving the attractor topology, a stable embedding preserves the attractor geometry by ensuring that distances between points in the state space are approximately preserved. In particular, we find that delay-coordinate mapping stably embeds an attractor of a dynamical system if the stable rank of the system is large enough to be proportional to the dimension of the attractor. The stable rank reflects the relation between the sampling interval and the number of delays in delay-coordinate mapping. Our theoretical findings give guidance to choosing system parameters, echoing the tradeoff between irrelevancy and redundancy that has been heuristically investigated in the literature. Our initial result is stated for attractors that are smooth submanifolds of Euclidean space, with extensions provided for the case of strange attractors.

Human responses to bright light of different durations.

PubMed

Chang, Anne-Marie; Santhi, Nayantara; St Hilaire, Melissa; Gronfier, Claude; Bradstreet, Dayna S; Duffy, Jeanne F; Lockley, Steven W; Kronauer, Richard E; Czeisler, Charles A

2012-07-01

Light exposure in the early night induces phase delays of the circadian rhythm in melatonin in humans. Previous studies have investigated the effect of timing, intensity, wavelength, history and pattern of light stimuli on the human circadian timing system. We present results from a study of the duration–response relationship to phase-delaying bright light. Thirty-nine young healthy participants (16 female; 22.18±3.62 years) completed a 9-day inpatient study. Following three baseline days, participants underwent an initial circadian phase assessment procedure in dim light (<3 lux), and were then randomized for exposure to a bright light pulse (∼10,000 lux) of 0.2 h, 1.0 h, 2.5 h or 4.0 h duration during a 4.5 h controlled-posture episode centred in a 16 h wake episode. After another 8 h sleep episode, participants completed a second circadian phase assessment. Phase shifts were calculated from the difference in the clock time of the dim light melatonin onset (DLMO) between the initial and final phase assessments. Exposure to varying durations of bright light reset the circadian pacemaker in a dose-dependent, non-linear manner. Per minute of exposure, the 0.2 h duration was over 5 times more effective at phase delaying the circadian pacemaker (1.07±0.36 h) as compared with the 4.0 h duration (2.65±0.24 h). Acute melatonin suppression and subjective sleepiness also had a dose-dependent response to light exposure duration. These results provide strong evidence for a non-linear resetting response of the human circadian pacemaker to light duration.

Implementation of a Breast/Reconstruction Surgery Coordinator to Reduce Preoperative Delays for Patients Undergoing Mastectomy With Immediate Reconstruction

PubMed Central

Losk, Katya; Mallory, Melissa A.; Camuso, Kristen; Cutone, Linda; Caterson, Stephanie; Bunnell, Craig A.

2016-01-01

Purpose: Mastectomy with immediate reconstruction (MIR) requires coordination between breast and reconstructive surgical teams, leading to increased preoperative delays that may adversely impact patient outcomes and satisfaction. Our cancer center established a target of 28 days from initial consultation with the breast surgeon to MIR. We sought to determine if a centralized breast/reconstructive surgical coordinator (BRC) could reduce care delays. Methods: A 60-day pilot to evaluate the impact of a BRC on timeliness of care was initiated at our cancer center. All reconstructive surgery candidates were referred to the BRC, who had access to surgical clinic and operating room schedules. The BRC worked with both surgical services to identify the earliest surgery dates and facilitated operative bookings. The median time to MIR and the proportion of MIR cases that met the time-to-treatment goal was determined. These results were compared with a baseline cohort of patients undergoing MIR during the same time period (January to March) in 2013 and 2014. Results: A total of 99 patients were referred to the BRC (62% cancer, 21% neoadjuvant, 17% prophylactic) during the pilot period. Focusing exclusively on patients with a cancer diagnosis, an 18.5% increase in the percentage of cases meeting the target (P = .04) and a 7-day reduction to MIR (P = .02) were observed. Conclusion: A significant reduction in time to MIR was achieved through the implementation of the BRC. Further research is warranted to validate these findings and assess the impact the BRC has on operational efficiency and workflows. PMID:26883406

Delay in weight bearing in surgically treated tibial shaft fractures is associated with impaired healing: a cohort analysis of 166 tibial fractures.

PubMed

Houben, I B; Raaben, M; Van Basten Batenburg, M; Blokhuis, T J

2018-04-09

The relation between timing of weight bearing after a fracture and the healing outcome is yet to be established, thereby limiting the implementation of a possibly beneficial effect for our patients. The current study was undertaken to determine the effect of timing of weight bearing after a surgically treated tibial shaft fracture. Surgically treated diaphyseal tibial fractures were retrospectively studied between 2007 and 2015. The timing of initial weight bearing (IWB) was analysed as a predictor for impaired healing in a multivariate regression. Totally, 166 diaphyseal tibial fractures were included, 86 cases with impaired healing and 80 with normal healing. The mean age was 38.7 years (range 16-89). The mean time until IWB was significantly shorter in the normal fracture healing group (2.6 vs 7.4 weeks, p < 0.001). Correlation analysis yielded four possible confounders: infection requiring surgical intervention, fracture type, fasciotomy and open fractures. Logistic regression identified IWB as an independent predictor for impaired healing with an odds ratio of 1.13 per week delay (95% CI 1.03-1.25). Delay in initial weight bearing is independently associated with impaired fracture healing in surgically treated tibial shaft fractures. Unlike other factors such as fracture type or soft tissue condition, early resumption of weight bearing can be influenced by the treating physician and this factor therefore has a direct clinical relevance. This study indicates that early resumption of weight bearing should be the treatment goal in fracture fixation. 3b.

Diminishing availability of publicly funded slots for antiretroviral initiation among HIV-infected ART-eligible patients in Uganda.

PubMed

Geng, Elvin H; Bwana, Mwebesa B; Kabakyenga, Jerome; Muyindike, Winnie; Emenyonu, Nneka I; Musinguzi, Nicholas; Mugyenyi, Peter; Martin, Jeffrey N; Bangsberg, David R

2010-11-24

The impact of flat-line funding in the global scale up of antiretroviral therapy (ART) for HIV-infected patients in Africa has not yet been well described. We evaluated ART-eligible patients and patients starting ART at a prototypical scale up ART clinic in Mbarara, Uganda between April 1, 2009 and May 14, 2010 where four stakeholders sponsor treatment - two PEPFAR implementing organizations, the Ugandan Ministry of Health - Global Fund (MOH-GF) and a private foundation named the Family Treatment Fund (FTF). We assessed temporal trends in the number of eligible patients, the number starting ART and tabulated the distribution of the stakeholders supporting ART initiation by month and quartile of time during this interval. We used survival analyses to assess changes in the rate of ART initiation over calendar time. A total of 1309 patients who were eligible for ART made visits over the 14 month period of the study and of these 819 started ART. The median number of ART eligible patients each month was 88 (IQR: 74 to 115). By quartile of calendar time, PEPFAR and MOH sponsored 290, 192, 180, and 49 ART initiations whereas the FTF started 1, 2, 1 and 104 patients respectively. By May of 2010 (the last calendar month of observation) FTF sponsored 88% of all ART initiations. Becoming eligible for ART in the 3(rd) (HR = 0.58, 95% 0.45-0.74) and 4(th) quartiles (HR = 0.49, 95% CI: 0.36-0.65) was associated with delay in ART initiation compared to the first quartile in multivariable analyses. During a period of flat line funding from multinational donors for ART programs, reductions in the number of ART initiations by public programs (i.e., PEPFAR and MOH-GF) and delays in ART initiation became apparent at the a large prototypical scale-up ART clinic in Uganda.

Shale oil recovery process

DOEpatents

Zerga, Daniel P.

1980-01-01

A process of producing within a subterranean oil shale deposit a retort chamber containing permeable fragmented material wherein a series of explosive charges are emplaced in the deposit in a particular configuration comprising an initiating round which functions to produce an upward flexure of the overburden and to initiate fragmentation of the oil shale within the area of the retort chamber to be formed, the initiating round being followed in a predetermined time sequence by retreating lines of emplaced charges developing further fragmentation within the retort zone and continued lateral upward flexure of the overburden. The initiating round is characterized by a plurality of 5-spot patterns and the retreating lines of charges are positioned and fired along zigzag lines generally forming retreating rows of W's. Particular time delays in the firing of successive charges are disclosed.

Delayed photolysis of liposomes: a strategy for the precision timing of bolus drug release using ex-vivo photochemical sensitization

NASA Astrophysics Data System (ADS)

Kozikowski, Raymond T.; Sorg, Brian S.

2012-03-01

Chemotherapy is a standard treatment for metastatic cancer. However drug toxicity limits the dosage that can safely be used, thus reducing treatment efficacy. Drug carrier particles, like liposomes, can help reduce toxicity by shielding normal tissue from drug and selectively depositing drug in tumors. Over years of development, liposomes have been optimized to avoid uptake by the Reticuloendothelial System (RES) as well as effectively retain their drug content during circulation. As a result, liposomes release drug passively, by slow leakage, but this uncontrolled drug release can limit treatment efficacy as it can be difficult to achieve therapeutic concentrations of drug at tumor sites even with tumor-specific accumulation of the carriers. Lipid membranes can be photochemically lysed by both Type I (photosensitizer-substrate) and Type II (photosensitizer-oxygen) reactions. It has been demonstrated in red blood cells (RBCs) in vitro that these photolysis reactions can occur in two distinct steps: a light-initiated reaction followed by a thermally-initiated reaction. These separable activation steps allow for the delay of photohemolysis in a controlled manner using the irradiation energy, temperature and photosensitizer concentration. In this work we have translated this technique from RBCs to liposomal nanoparticles. To that end, we present in vitro data demonstrating this delayed bolus release from liposomes, as well as the ability to control the timing of this event. Further, we demonstrate for the first time the improved delivery of bioavailable cargo selectively to target sites in vivo.

How mistimed and unwanted pregnancies affect timing of antenatal care initiation in three districts in Tanzania

PubMed Central

2013-01-01

Background Early antenatal care (ANC) initiation is a doorway to early detection and management of potential complications associated with pregnancy. Although the literature reports various factors associated with ANC initiation such as parity and age, pregnancy intentions is yet to be recognized as a possible predictor of timing of ANC initiation. Methods Data originate from a cross-sectional household survey on health behaviour and service utilization patterns. The survey was conducted in 2011 in Rufiji, Kilombero and Ulanga districts in Tanzania on 3,127 women from whom 910 of reproductive age who had given birth in the past two years and sought ANC at least once during pregnancy were selected for the current analysis. ANC initiation was considered to be early only if it occurred in the first trimester of pregnancy gestation. A recently completed pregnancy was defined as mistimed if a woman wanted it later, and if she did not want it at all the pregnancy was termed as unwanted. Chi-square was used to test for associations and multinomial logistic regression was conducted to examine how mistimed and unwanted pregnancies relate with timing of ANC initiation. Results Although 49.3% of the women intended to become pregnant, 50.7% (34.9% mistimed and 15.8% unwanted) became pregnant unintentionally. While ANC initiation in the 1st trimester was 18.5%, so was 71.7% and 9.9% in the 2nd and 3rd trimesters respectively. Multivariate analysis revealed that ANC initiation in the 2nd trimester was 1.68 (95% CI 1.10–2.58) and 2.00 (95% CI 1.05–3.82) times more likely for mistimed and unwanted pregnancies respectively compared to intended pregnancies. These estimates rose to 2.81 (95% CI 1.41–5.59) and 4.10 (95% CI 1.68–10.00) respectively in the 3rd trimester. We controlled for gravidity, age, education, household wealth, marital status, religion, district of residence and travel time to a health facility. Conclusion Late ANC initiation is a significant maternal and child health consequence of mistimed and unwanted pregnancies in Tanzania. Women should be empowered to delay or avoid pregnancies whenever they need to do so. Appropriate counseling to women, especially those who happen to conceive unintentionally is needed to minimize the possibility of delaying ANC initiation. PMID:23388110

How mistimed and unwanted pregnancies affect timing of antenatal care initiation in three districts in Tanzania.

PubMed

Exavery, Amon; Kanté, Almamy Malick; Hingora, Ahmed; Mbaruku, Godfrey; Pemba, Senga; Phillips, James F

2013-02-06

Early antenatal care (ANC) initiation is a doorway to early detection and management of potential complications associated with pregnancy. Although the literature reports various factors associated with ANC initiation such as parity and age, pregnancy intentions is yet to be recognized as a possible predictor of timing of ANC initiation. Data originate from a cross-sectional household survey on health behaviour and service utilization patterns. The survey was conducted in 2011 in Rufiji, Kilombero and Ulanga districts in Tanzania on 3,127 women from whom 910 of reproductive age who had given birth in the past two years and sought ANC at least once during pregnancy were selected for the current analysis. ANC initiation was considered to be early only if it occurred in the first trimester of pregnancy gestation. A recently completed pregnancy was defined as mistimed if a woman wanted it later, and if she did not want it at all the pregnancy was termed as unwanted. Chi-square was used to test for associations and multinomial logistic regression was conducted to examine how mistimed and unwanted pregnancies relate with timing of ANC initiation. Although 49.3% of the women intended to become pregnant, 50.7% (34.9% mistimed and 15.8% unwanted) became pregnant unintentionally. While ANC initiation in the 1st trimester was 18.5%, so was 71.7% and 9.9% in the 2nd and 3rd trimesters respectively. Multivariate analysis revealed that ANC initiation in the 2nd trimester was 1.68 (95% CI 1.10-2.58) and 2.00 (95% CI 1.05-3.82) times more likely for mistimed and unwanted pregnancies respectively compared to intended pregnancies. These estimates rose to 2.81 (95% CI 1.41-5.59) and 4.10 (95% CI 1.68-10.00) respectively in the 3rd trimester. We controlled for gravidity, age, education, household wealth, marital status, religion, district of residence and travel time to a health facility. Late ANC initiation is a significant maternal and child health consequence of mistimed and unwanted pregnancies in Tanzania. Women should be empowered to delay or avoid pregnancies whenever they need to do so. Appropriate counseling to women, especially those who happen to conceive unintentionally is needed to minimize the possibility of delaying ANC initiation.

Gestational Age at First Antenatal Care Visit in Malawi.

PubMed

Mkandawire, Paul

2015-11-01

This paper examines the gestational age at first antenatal care (ANC) visit and factors associated with timely initiation of ANC in Malawi in a context where maternal and child health services are generally provided for free. Lognormal survival models are applied to Demographic and Health Survey data from a nationally representative sample of women (n = 13,588) of child-bearing age. The findings of this study show that less than 30 % of pregnant women initiate ANC within the World Health Organization recommended gestational timeframe of 16 weeks or earlier. The hazard analysis shows a gradient in the initiation of ANC by maternal education level, with least educated mothers most likely to delay their first ANC visit. However, after adjusting for variables capturing intimate partner violence in the multivariate models, the effect of maternal education attenuated and lost statistical significance. Other significant predictors of gestational age at first ANC include media exposure, perceived distance from health facility, age, and birth order. The findings of the study link domestic violence directly with the gestational age at which mothers initiate ANC, suggesting that gender-based violence may operate through delayed initiation of ANC to undermine maternal and child health outcomes.

Impact of early initiation of corticosteroid therapy on cardiac function and rhythm in patients with cardiac sarcoidosis.

PubMed

Padala, Santosh K; Peaslee, Samuel; Sidhu, Mandeep S; Steckman, David A; Judson, Marc A

2017-01-15

There is limited data on the effect of corticosteroid therapy in patients with cardiac sarcoidosis (CS). We sought to examine the impact of early initiation of corticosteroid therapy, within a month of CS diagnosis, on left ventricular ejection fraction (LVEF), ventricular arrhythmias (VAs), and atrioventricular (AV) block. We retrospectively identified 30 CS patients from a large university sarcoidosis clinic. The effect of early initiation of corticosteroid therapy on LVEF was assessed by serial echocardiography, and on VAs and AV block was assessed by Holter monitoring and/or device interrogations. The median time from diagnosis of extra-cardiac sarcoidosis to CS was 40months. 90% (27/30) of the CS patients received corticosteroid therapy and 85% percent (23/27) had early initiation of corticosteroid therapy. Fourteen patients (47%) had reduced EF<50%. 9/14 patients who had early initiation of corticosteroid therapy had improvement in mean EF (25% to 46%, P<0.001); 5/14 patients who had a delay in initiation or who did not receive corticosteroids had no improvement in mean EF (41% to 37%, P=0.47). Fourteen patients (47%) had VAs and 5 patients (17%) had advanced AV block. Early initiation of corticosteroid therapy resulted in no VA recurrences in 8/11 patients (72%), and complete recovery of AV conduction in 2/3 patients (67%). Patients with VAs (n=3) or advanced AV block (n=2) who failed to receive early corticosteroid therapy did not show improvement. There is often a delay in manifestation of cardiac sarcoidosis for several years from the diagnosis of extra-cardiac sarcoidosis. Prompt initiation of corticosteroid therapy in CS patients may improve outcomes whereas delayed initiation of corticosteroids or failure to use corticosteroids may be associated with worse outcomes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Temporal framing and the hidden-zero effect: rate-dependent outcomes on delay discounting.

PubMed

Naudé, Gideon P; Kaplan, Brent A; Reed, Derek D; Henley, Amy J; DiGennaro Reed, Florence D

2018-05-01

Recent research suggests that presenting time intervals as units (e.g., days) or as specific dates, can modulate the degree to which humans discount delayed outcomes. Another framing effect involves explicitly stating that choosing a smaller-sooner reward is mutually exclusive to receiving a larger-later reward, thus presenting choices as an extended sequence. In Experiment 1, participants (N = 201) recruited from Amazon Mechanical Turk completed the Monetary Choice Questionnaire in a 2 (delay framing) by 2 (zero framing) design. Regression suggested a main effect of delay, but not zero, framing after accounting for other demographic variables and manipulations. We observed a rate-dependent effect for the date-framing group, such that those with initially steep discounting exhibited greater sensitivity to the manipulation than those with initially shallow discounting. Subsequent analyses suggest these effects cannot be explained by regression to the mean. Experiment 2 addressed the possibility that the null effect of zero framing was due to within-subject exposure to the hidden- and explicit-zero conditions. A new Amazon Mechanical Turk sample completed the Monetary Choice Questionnaire in either hidden- or explicit-zero formats. Analyses revealed a main effect of reward magnitude, but not zero framing, suggesting potential limitations to the generality of the hidden-zero effect. © 2018 Society for the Experimental Analysis of Behavior.

Transition in Pediatric and Adolescent Hypogonadal Girls: Gynecological Aspects, Estrogen Replacement Therapy, and Contraception.

PubMed

Tønnes Pedersen, Anette; Cleemann, Line; Main, Katharina M; Juul, Anders

2018-01-01

Hypogonadism may be suspected if puberty is delayed. Pubertal delay may be caused by a normal physiological variant, by primary ovarian insufficiency (Turner syndrome), or reflect congenital hypogonadotropic hypogonadism (HH; genetic) or acquired HH (brain lesions). Any underlying chronic disease like inflammatory bowel disease, celiac disease, malnutrition (anorexia or orthorexia), or excessive physical activity may also result in functional HH. Thus, girls with delayed puberty should be evaluated for an underlying pathology before any treatment, including oral contraception, is initiated. Estrogen replacement is important and natural 17β-estradiol, preferably transdermally, is the preferred choice, whereas the oral route can be used as an alternative depending on patient preference and compliance. Sexual activity is often delayed in the hypogonadal adolescent girl. In the adolescent hypogonadal girl, hormone replacement therapy (HRT) most likely has been initiated at the time she becomes sexually active. If a risk of unwanted pregnancy cannot be ruled out, there is a need to consider contraception. This consideration does not contradict the principles of HRT but can be included as a part of the substitution, e.g. oral contraceptives containing 17β-estradiol or a progestogen intrauterine device combined with continuous 17β-estradiol (transdermal or oral). © 2018 S. Karger AG, Basel.

Development and implementation of mass media campaigns to delay sexual initiation among African American and White youth.

PubMed

Noar, Seth M; Zimmerman, Rick S; Palmgreen, Philip; Cupp, Pamela K; Floyd, Brenikki R; Mehrotra, Purnima

2014-01-01

Reducing new HIV/STD infections among at-risk adolescents requires developing and evaluating evidence-based health communication approaches. Research overwhelmingly supports the conclusion that early sexual initiation is associated with STDs and other negative outcomes in later years (e.g., unintended pregnancy). The authors' research group secured funding from the National Institute of Mental Health to develop, implement, and rigorously evaluate televised mass media campaigns to delay initiation of sexual intercourse among African American and White adolescents in two cities in the Southeastern United States. The focus of the present study is on the development and implementation of the campaigns, including (a) rationale and theoretical underpinnings; (b) collection, screening, and assessment of existing public service announcements; (c) development of new public service announcements; (d) study design and campaign airing plan; and (e) message exposure achieved in the campaigns. Health communication campaigns hold much promise in reaching at-risk adolescent populations with targeted, timely, and relevant risk-reduction messages.

Time to Adjuvant Chemotherapy for Breast Cancer in National Comprehensive Cancer Network Institutions

PubMed Central

2013-01-01

Background High-quality care must be not only appropriate but also timely. We assessed time to initiation of adjuvant chemotherapy for breast cancer as well as factors associated with delay to help identify targets for future efforts to reduce unnecessary delays. Methods Using data from the National Comprehensive Cancer Network (NCCN) Outcomes Database, we assessed the time from pathological diagnosis to initiation of chemotherapy (TTC) among 6622 women with stage I to stage III breast cancer diagnosed from 2003 through 2009 and treated with adjuvant chemotherapy in nine NCCN centers. Multivariable models were constructed to examine factors associated with TTC. All statistical tests were two-sided. Results Mean TTC was 12.0 weeks overall and increased over the study period. A number of factors were associated with a longer TTC. The largest effects were associated with therapeutic factors, including immediate postmastectomy reconstruction (2.7 weeks; P < .001), re-excision (2.1 weeks; P < .001), and use of the 21-gene reverse-transcription polymerase chain reaction assay (2.2 weeks; P < .001). In comparison with white women, a longer TTC was observed among black (1.5 weeks; P < .001) and Hispanic (0.8 weeks; P < .001) women. For black women, the observed disparity was greater among women who transferred their care to the NCCN center after diagnosis (P interaction = .008) and among women with Medicare vs commercial insurance (P interaction < .001). Conclusions Most observed variation in TTC was related to use of appropriate therapeutic interventions. This suggests the importance of targeted efforts to minimize potentially preventable causes of delay, including inefficient transfers in care or prolonged appointment wait times. PMID:23264681

Temporary Losses of Highway Capacity and Impacts on Performance: Phase 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chin, S.M.

2004-11-10

Traffic congestion and its impacts significantly affect the nation's economic performance and the public's quality of life. In most urban areas, travel demand routinely exceeds highway capacity during peak periods. In addition, events such as crashes, vehicle breakdowns, work zones, adverse weather, railroad crossings, large trucks loading/unloading in urban areas, and other factors such as toll collection facilities and sub-optimal signal timing cause temporary capacity losses, often worsening the conditions on already congested highway networks. The impacts of these temporary capacity losses include delay, reduced mobility, and reduced reliability of the highway system. They can also cause drivers to re-routemore » or reschedule trips. Such information is vital to formulating sound public policies for the highway infrastructure and its operation. In response to this need, Oak Ridge National Laboratory, sponsored by the Federal Highway Administration (FHWA), made an initial attempt to provide nationwide estimates of the capacity losses and delay caused by temporary capacity-reducing events (Chin et al. 2002). This study, called the Temporary Loss of Capacity (TLC) study, estimated capacity loss and delay on freeways and principal arterials resulting from fatal and non-fatal crashes, vehicle breakdowns, and adverse weather, including snow, ice, and fog. In addition, it estimated capacity loss and delay caused by sub-optimal signal timing at intersections on principal arterials. It also included rough estimates of capacity loss and delay on Interstates due to highway construction and maintenance work zones. Capacity loss and delay were estimated for calendar year 1999, except for work zone estimates, which were estimated for May 2001 to May 2002 due to data availability limitations. Prior to the first phase of this study, which was completed in May of 2002, no nationwide estimates of temporary losses of highway capacity by type of capacity-reducing event had been made. This report describes the second phase of the TLC study (TLC2). TLC2 improves upon the first study by expanding the scope to include delays from rain, toll collection facilities, railroad crossings, and commercial truck pickup and delivery (PUD) activities in urban areas. It includes estimates of work zone capacity loss and delay for all freeways and principal arterials, rather than for Interstates only. It also includes improved estimates of delays caused by fog, snow, and ice, which are based on data not available during the initial phase of the study. Finally, computational errors involving crash and breakdown delay in the original TLC report are corrected.« less

Relationship between Weather, Traffic and Delay Based on Empirical Methods

NASA Technical Reports Server (NTRS)

Sridhar, Banavar; Swei, Sean S. M.

2006-01-01

The steady rise in demand for air transportation over the years has put much emphasis on the need for sophisticated air traffic flow management (TFM) within the National Airspace System (NAS). The NAS refers to hardware, software and people, including runways, radars, networks, FAA, airlines, etc., involved in air traffic management (ATM) in the US. One of the metrics that has been used to assess the performance of NAS is the actual delays provided through FAA's Air Traffic Operations Network (OPSNET). The OPSNET delay data includes those reportable delays, i.e. delays of 15 minutes or more experienced by Instrument Flight Rule (IFR) flights, submitted by the FAA facilities. These OPSNET delays are caused by the application of TFM initiatives in response to, for instance, weather conditions, increased traffic volume, equipment outages, airline operations, and runway conditions. TFM initiatives such as, ground stops, ground delay programs, rerouting, airborne holding, and miles-in-trail restrictions, are actions which are needed to control the air traffic demand to mitigate the demand-capacity imbalance due to the reduction in capacity. Consequently, TFM initiatives result in NAS delays. Of all the causes, weather has been identified as the most important causal factor for NAS delays. Therefore, in order to accurately assess the NAS performance, it has become necessary to create a baseline for NAS performance and establish a model which characterizes the relation between weather and NAS delays.

The Initiation of Smooth Pursuit is Delayed in Anisometropic Amblyopia.

PubMed

Raashid, Rana Arham; Liu, Ivy Ziqian; Blakeman, Alan; Goltz, Herbert C; Wong, Agnes M F

2016-04-01

Several behavioral studies have shown that the reaction times of visually guided movements are slower in people with amblyopia, particularly during amblyopic eye viewing. Here, we tested the hypothesis that the initiation of smooth pursuit eye movements, which are responsible for accurately keeping moving objects on the fovea, is delayed in people with anisometropic amblyopia. Eleven participants with anisometropic amblyopia and 14 visually normal observers were asked to track a step-ramp target moving at ±15°/s horizontally as quickly and as accurately as possible. The experiment was conducted under three viewing conditions: amblyopic/nondominant eye, binocular, and fellow/dominant eye viewing. Outcome measures were smooth pursuit latency, open-loop gain, steady state gain, and catch-up saccade frequency. Participants with anisometropic amblyopia initiated smooth pursuit significantly slower during amblyopic eye viewing (206 ± 20 ms) than visually normal observers viewing with their nondominant eye (183 ± 17 ms, P = 0.002). However, mean pursuit latency in the anisometropic amblyopia group during binocular and monocular fellow eye viewing was comparable to the visually normal group. Mean open-loop gain, steady state gain, and catch-up saccade frequency were similar between the two groups, but participants with anisometropic amblyopia exhibited more variable steady state gain (P = 0.045). This study provides evidence of temporally delayed smooth pursuit initiation in anisometropic amblyopia. After initiation, the smooth pursuit velocity profile in anisometropic amblyopia participants is similar to visually normal controls. This finding differs from what has been observed previously in participants with strabismic amblyopia who exhibit reduced smooth pursuit velocity gains with more catch-up saccades.

It’s Your Game. Keep It Real: Delaying Sexual Behavior with an Effective Middle School Program

PubMed Central

Tortolero, Susan R.; Markham, Christine M.; Peskin, Melissa Fleschler; Shegog, Ross; Addy, Robert C.; Escobar-Chaves, S. Liliana; Baumler, Elizabeth R.

2009-01-01

Purpose This study tested the effects of a theory-based middle-school HIV, STI, and pregnancy prevention program, It’s Your Game: Keep it Real (IYG), in delaying sexual behavior. We hypothesized that the IYG intervention would decrease the number of adolescents who initiated sexual activity by the 9th grade compared to those in the comparison schools. Methods The target population was English-speaking middle schoolers from a large urban predominantly African American and Hispanic school district in Southeast Texas. Ten middle schools were randomly assigned either to receive the intervention or to the comparison condition. Seventh-grade students were recruited and followed through 9th grade. The IYG intervention comprises 12 seventh-grade and 12 eighth-grade lessons that integrate group-based classroom activities with computer-based instruction and personal journaling. Ninth-grade follow-up surveys were completed by 907 students (92% of the defined cohort). The primary hypothesis tested was that the intervention would decrease the number of adolescents who initiated sexual activity by the 9th grade compared to those in the comparison schools. Results Almost one-third (29.9%, n=509) of those in the comparison condition initiated sex by 9th grade compared to almost one-quarter (23.4%, n=308) of those in the intervention condition. After adjusting for covariates, students in the comparison condition were 1.29 times more likely to initiate sex by the 9th grade than those in the intervention condition. Conclusions A theory-driven multi-component, curriculum-based intervention can delay sexual initiation up to 24 months; can have impact on specific types of sexual behavior such as initiation of oral and anal sex; and may be especially effective with females. Future research must explore the generalizabilty of these results. PMID:20113923

Learning from Feedback: Spacing and the Delay-Retention Effect

ERIC Educational Resources Information Center

Smith, Troy A.; Kimball, Daniel R.

2010-01-01

Most modern research on the effects of feedback during learning has assumed that feedback is an error correction mechanism. Recent studies of feedback-timing effects have suggested that feedback might also strengthen initially correct responses. In an experiment involving cued recall of trivia facts, we directly tested several theories of…

Use of Psychotherapy by Rural and Urban Veterans

ERIC Educational Resources Information Center

Cully, Jeffrey A.; Jameson, John P.; Phillips, Laura L.; Kunik, Mark E.; Fortney, John C.

2010-01-01

Purpose: To examine whether differences exist between rural and urban veterans in terms of initiation of psychotherapy, delay in time from diagnosis to treatment, and dose of psychotherapy sessions. Methods: Using a longitudinal cohort of veterans obtained from national Veterans Affairs databases (October 2003 through September 2004), we extracted…

Mimicking Accented Speech as L2 Phonological Awareness

ERIC Educational Resources Information Center

Mora, Joan C.; Rochdi, Youssef; Kivistö-de Souza, Hanna

2014-01-01

This study investigated Spanish-speaking learners' awareness of a non-distinctive phonetic difference between Spanish and English through a delayed mimicry paradigm. We assessed learners' speech production accuracy through voice onset time (VOT) duration measures in word-initial pre-vocalic /p t k/ in Spanish and English words, and in Spanish…

Assessing Self-Control Training in Children with Attention Deficit Hyperactivity Disorder

ERIC Educational Resources Information Center

Bloh, Christopher

2009-01-01

This study examined the use of a progressive delay procedure with and without a concurrent activity to teach self-control to children with attention deficit hyperactivity disorder. Three participants were initially required to wait progressively longer periods of time for access to preferred edible reinforcers. After demonstrating this…

Time required for institutional review board review at one Veterans Affairs medical center.

PubMed

Hall, Daniel E; Hanusa, Barbara H; Stone, Roslyn A; Ling, Bruce S; Arnold, Robert M

2015-02-01

Despite growing concern that institutional review boards (IRBs) impose burdensome delays on research, little is known about the time required for IRB review across different types of research. To measure the overall and incremental process times for IRB review as a process of quality improvement. After developing a detailed process flowchart of the IRB review process, 2 analysts abstracted temporal data from the records pertaining to all 103 protocols newly submitted to the IRB at a large urban Veterans Affairs medical center from June 1, 2009, through May 31, 2011. Disagreements were reviewed with the principal investigator to reach consensus. We then compared the review times across review types using analysis of variance and post hoc Scheffé tests after achieving normally distributed data through logarithmic transformation. Calendar days from initial submission to final approval of research protocols. Initial IRB review took 2 to 4 months, with expedited and exempt reviews requiring less time (median [range], 85 [23-631] and 82 [16-437] days, respectively) than full board reviews (median [range], 131 [64-296] days; P = .008). The median time required for credentialing of investigators was 1 day (range, 0-74 days), and review by the research and development committee took a median of 15 days (range, 0-184 days). There were no significant differences in credentialing or research and development times across review types (exempt, expedited, or full board). Of the extreme delays in IRB review, 80.0% were due to investigators' slow responses to requested changes. There were no systematic delays attributable to the information security officer, privacy officer, or IRB chair. Measuring and analyzing review times is a critical first step in establishing a culture and process of continuous quality improvement among IRBs that govern research programs. The review times observed at this IRB are substantially longer than the 60-day target recommended by expert panels. The method described here could be applied to other IRBs to begin identifying and improving inefficiencies.

Investigation of the effects of bandwidth and time delay on helicopter roll-axis handling qualities

NASA Technical Reports Server (NTRS)

Pausder, Heinz-Juergen; Blanken, Chris L.

1992-01-01

Several years of cooperative research conducted under the U.S./German Memorandum of Understanding (MOU) in helicopter flight control has recently resulted in a successful handling qualities study. The focus of this cooperative research has been the effects on handling qualities due to time delays in combination with a high bandwidth vehicle. The jointly performed study included the use of U.S. ground-based simulation and German in-flight simulation facilities. The NASA-Ames Vertical Motion Simulator (VMS) was used to develop a high bandwidth slalom tracking task which took into consideration the constraints of the facilities. The VMS was also used to define a range of the test parameters and to perform initial handling qualities evaluations. The flight tests were conducted using DLR's variable-stability BO 105 S3 Advanced Technology Testing Helicopter System (ATTHeS). Configurations included a rate command and an attitude command response system with added time delays up to 160 milliseconds over the baseline and bandwidth values between 1.5 and 4.5 rad/sec. Sixty-six evaluations were performed in about 25 hr of flight time during 10 days of testing. The results indicate a need to more tightly constrain the allowable roll axis phase delay for the Level 1 and Level 2 requirements in the U.S. Army's specification for helicopter handling qualities, ADS-33C.

Investigation of the effects of bandwidth and time delay on helicopter roll-axis handling qualities

NASA Technical Reports Server (NTRS)

Blanken, Chris L.; Pausder, Heinz-Jurgen

1994-01-01

Several years of cooperative research conducted under the U.S./German Memorandum of Understanding (MOU) in helicopter aeromechanics have recently resulted in a successful handling qualities study. The focus of this cooperative research has been the effect of time delays in a high bandwidth vehicle on handling qualities. The jointly performed study included the use of U.S. ground-based simulation and German in-flight simulation facilities. The NASA-Ames Vertical Motion Simulator (VMS) was used to develop a high bandwidth slalom tracking task which took into consideration the constraints of the facilities. The VMS was used to define a range of the test parameters and to perform initial handling qualities evaluations. The flight tests were conducted using DLR's variable-stability BO 105 S3 Advanced Technology Testing Helicopter System (ATTHeS). Configurations included a rate command and an attitude command response system with added time delays of up to 160 milliseconds over the baseline and band width values between 1.5 and 4.5 rad/sec. Sixty-six evaluations were performed in about 25 hours of flight time during ten days of testing. The results indicate a need to more tightly constrain the allowable roll axis phase delay for the Level 1 and Level 2 requirements in the U.S. Army's specification for helicopter handling qualities Aeronautical Design Standard (ADS)-33C.

Investigation of the effects of bandwidth and time delay on helicopter roll-axis handling qualities

NASA Technical Reports Server (NTRS)

Pausder, Heinz-Juergen; Blanken, Chris L.

1993-01-01

Several years of cooperative research conducted under the U.S./German Memorandum of Understanding (MOU) in helicopter flight control has recently resulted in a successful handling qualities study. The focus of this cooperative research has been the effects on handling qualities due to time delays in combination with a high bandwidth vehicle. The jointly performed study included the use of U.S. ground-based simulation and German in-flight simulation facilities. The NASA-Ames Vertical Motion Simulator (VMS) was used to develop a high bandwidth slalom tracking task which took into consideration the constraints of the facilities. The VMS was also used to define a range of the test parameters and to perform initial handling qualities evaluations. The flight tests were conducted using DLR's variable-stability BO 105 S3 Advanced Technology Testing Helicopter System (ATTHeS). Configurations included a rate command and an attitude command response system with added time delays up to 160 milliseconds over the baseline and bandwidth values between 1.5 and 4.5 rad/sec. Sixty-six evaluations were performed in about 25 hours of flight time during ten days of testing. The results indicate a need to more tightly constrain the allowable roll axis phase delay for the Level 1 and Level 2 requirements in the U.S. Army's specification for helicopter handling qualities, ADS-33C.

Delay and refusal of human papillomavirus vaccine for girls, national immunization survey-teen, 2010.

PubMed

Dorell, Christina; Yankey, David; Jeyarajah, Jenny; Stokley, Shannon; Fisher, Allison; Markowitz, Lauri; Smith, Philip J

2014-03-01

Human papillomavirus (HPV) vaccine coverage among girls is low. We used data reported by parents of 4103 girls, 13 to 17 years old, to assess associations with, and reasons for, delaying or refusing HPV vaccination. Sixty-nine percent of parents neither delayed nor refused vaccination, 11% delayed only, 17% refused only, and 3% both delayed and refused. Eighty-three percent of girls who delayed only, 19% who refused only, and 46% who both delayed and refused went on to initiate the vaccine series or intended to initiate it within the next 12 months. A significantly higher proportion of parents of girls who were non-Hispanic white, lived in households with higher incomes, and had mothers with higher education levels, delayed and/or refused vaccination. The most common reasons for nonvaccination were concerns about lasting health problems from the vaccine, wondering about the vaccine's effectiveness, and believing the vaccine is not needed.

Adaptive iterative learning control of a class of nonlinear time-delay systems with unknown backlash-like hysteresis input and control direction.

PubMed

Wei, Jianming; Zhang, Youan; Sun, Meimei; Geng, Baoliang

2017-09-01

This paper presents an adaptive iterative learning control scheme for a class of nonlinear systems with unknown time-varying delays and control direction preceded by unknown nonlinear backlash-like hysteresis. Boundary layer function is introduced to construct an auxiliary error variable, which relaxes the identical initial condition assumption of iterative learning control. For the controller design, integral Lyapunov function candidate is used, which avoids the possible singularity problem by introducing hyperbolic tangent funciton. After compensating for uncertainties with time-varying delays by combining appropriate Lyapunov-Krasovskii function with Young's inequality, an adaptive iterative learning control scheme is designed through neural approximation technique and Nussbaum function method. On the basis of the hyperbolic tangent function's characteristics, the system output is proved to converge to a small neighborhood of the desired trajectory by constructing Lyapunov-like composite energy function (CEF) in two cases, while keeping all the closed-loop signals bounded. Finally, a simulation example is presented to verify the effectiveness of the proposed approach. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

DISP: Optimizations towards Scalable MPI Startup

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Huansong; Pophale, Swaroop S; Gorentla Venkata, Manjunath

2016-01-01

Despite the popularity of MPI for high performance computing, the startup of MPI programs faces a scalability challenge as both the execution time and memory consumption increase drastically at scale. We have examined this problem using the collective modules of Cheetah and Tuned in Open MPI as representative implementations. Previous improvements for collectives have focused on algorithmic advances and hardware off-load. In this paper, we examine the startup cost of the collective module within a communicator and explore various techniques to improve its efficiency and scalability. Accordingly, we have developed a new scalable startup scheme with three internal techniques, namelymore » Delayed Initialization, Module Sharing and Prediction-based Topology Setup (DISP). Our DISP scheme greatly benefits the collective initialization of the Cheetah module. At the same time, it helps boost the performance of non-collective initialization in the Tuned module. We evaluate the performance of our implementation on Titan supercomputer at ORNL with up to 4096 processes. The results show that our delayed initialization can speed up the startup of Tuned and Cheetah by an average of 32.0% and 29.2%, respectively, our module sharing can reduce the memory consumption of Tuned and Cheetah by up to 24.1% and 83.5%, respectively, and our prediction-based topology setup can speed up the startup of Cheetah by up to 80%.« less

Treatment effect expressed as the novel Delay of Event measure is associated with high willingness to initiate preventive treatment - A randomized survey experiment comparing effect measures.

PubMed

Berglund, Erik; Westerling, Ragnar; Sundström, Johan; Lytsy, Per

2016-12-01

This study aimed to investigate patients' willingness to initiate a preventive treatment and compared two established effect measures to the newly developed Delay of Events (DoE) measure that expresses treatment effect as a gain in event-free time. In this cross-sectional, randomized survey experiment in the general Swedish population,1079 respondents (response rate 60.9%) were asked to consider a preventive cardiovascular treatment. Respondents were randomly allocated to one of three effect descriptions: DoE, relative risk reduction (RRR), or absolute risk reduction (ARR). Univariate and multivariate analyses were performed investigating willingness to initiate treatment, views on treatment benefit, motivation and importance to adhere and willingness to pay for treatment. Eighty-one percent were willing to take the medication when the effect was described as DoE, 83.0% when it was described as RRR and 62.8% when it was described as ARR. DoE and RRR was further associated with positive views on treatment benefit, motivation, importance to adhere and WTP. Presenting treatment effect as DoE or RRR was associated with a high willingness to initiate treatment. An approach based on the novel time-based measure DoE may be of value in clinical communication and shared decision making. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Characterization of Days Based On Analysis of National Airspace System Performance Metrics

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.; Musaffar, Bassam; Meyn, Larry A.; Quon, Leighton K.

2006-01-01

Days of operations in the National Airspace System can be described in term of traffic demand, runway conditions, equipment outages, and surface and enroute weather conditions. These causes manifest themselves in terms of departure delays, arrival delays, enroute delays and traffic flow management delays, Traffic flow management initiatives such as, ground stops, ground delay programs, miles-in-trail restrictions, rerouting and airborne holding are imposed to balance the air traffic demand with respect to the available capacity, In order to maintain operational efficiency of the National Airspace System, the Federal Aviation Administration (FAA) maintains delay sad other statistics in the Air Traffic Operations Network (OPSNET) and the Aviation System Performance Metrics (ASPM) databases. OPSNET data includes reportable delays of fifteen minutes ox more experienced by Instrument Flight Rule (IFR) flights. Numbers of aircraft affected by departure delays, enroute delays, arrival delays and traffic flow delays are recorded in the OPSNET data. ASPM data consist of number of actual departures, number of canceled departures, percentage of on time departures, percentage of on time gate arrivals, taxi-out delays. taxi-in delays, gate delays, arrival delays and block delays. Surface conditions at the major U.S. airports are classified in terms of Instrument Meteorological Condition (IMC) and Visual Meteorological Condition (VMC) as a function of the time of the day in the ASPM data. The main objective of this paper is to use OPSNET and ASPM data to classify the days in the datasets into few distinct groups, where each group is separated from the other groups in terms of a distance metric. The motivations for classifying the days are two-fold, 1) to enable selection of days of traffic with particular operational characteristics for concept evaluation using system-wide simulation systems such as the National Aeronautics and Space Administration's Airspace Concepts Evaluation Tool (ACES) and 2) to enable evaluation of a given day with respect to the characteristics of the classified groups. The first part of the paper is devoted to the analysis of major trends seen in the OPSNET and ASPM data. The second part of the paper is devoted to describing features or measures derived from the OPSNET and ASPM data that are suitable for characterizing days, and the classification algorithm used for grouping the days. Finally, the method for evaluating the characteristics of a given day with respect to the properties of the groups is described.

Flash trajectory imaging of target 3D motion

NASA Astrophysics Data System (ADS)

Wang, Xinwei; Zhou, Yan; Fan, Songtao; He, Jun; Liu, Yuliang

2011-03-01

We present a flash trajectory imaging technique which can directly obtain target trajectory and realize non-contact measurement of motion parameters by range-gated imaging and time delay integration. Range-gated imaging gives the range of targets and realizes silhouette detection which can directly extract targets from complex background and decrease the complexity of moving target image processing. Time delay integration increases information of one single frame of image so that one can directly gain the moving trajectory. In this paper, we have studied the algorithm about flash trajectory imaging and performed initial experiments which successfully obtained the trajectory of a falling badminton. Our research demonstrates that flash trajectory imaging is an effective approach to imaging target trajectory and can give motion parameters of moving targets.

Effect of Conflict Resolution Maneuver Execution Delay on Losses of Separation

NASA Technical Reports Server (NTRS)

Cone, Andrew C.

2010-01-01

This paper examines uncertainty in the maneuver execution delay for data linked conflict resolution maneuvers. This uncertainty could cause the previously cleared primary conflict to reoccur or a secondary conflict to appear. Results show that the likelihood of a primary conflict reoccurring during a horizontal conflict resolution maneuver increases with larger initial turn-out angles and with shorter times until loss of separation. There is also a significant increase in the probability of a primary conflict reoccurring when the time until loss falls under three minutes. Increasing horizontal separation by an additional 1.5 nmi lowers the risk, but does not completely eliminate it. Secondary conflicts were shown to have a small probability of occurring in all tested configurations.

Predictors of Time to Union After Operative Fixation of Closed Ankle Fractures.

PubMed

Matson, Andrew P; Hamid, Kamran S; Adams, Samuel B

2017-08-01

Ankle fractures are common and represent a significant burden to society. We aim to report the rate of union as determined by clinical and radiographic data, and to identify factors that predict time to union. A cohort of 112 consecutive patients with isolated, closed, operative malleolar ankle fractures treated with open reduction and internal fixation was retrospectively reviewed for time to clinical union. Clinical union was defined based on radiographic and clinical parameters, and delayed union was defined by time to union >12 weeks. Injury characteristics, patient factors and treatment variables were recorded, and statistical techniques employed included the Chi-square test, the Student's T-test, and multivariate linear regression modeling. Forty-two (37.5%) of patients who achieved union did so in less than 12 weeks, and 69 (61.6%) of these patients demonstrated delayed union at a mean of 16.7 weeks (range, 12.1-26.7 weeks), and the remaining patient required revision surgery. Factors associated with higher rates of delayed union or increased time to union included tobacco use, bimalleolar fixation, and high energy mechanism (all p<0.05). In regression analysis, statistically significant negative predictors of time to union were BMI, dislocation of the tibiotalar joint, external fixation for initial stabilization and delay of definitive management (all p<0.05). Patient characteristics, injury factors and treatment variables are predictive of time to union following open reduction and internal fixation of closed ankle fractures. These findings should assist with patient counseling, and help guide the provider when considering adjunctive therapies that promote bone healing. Prognostic, Level IV: Case series.

Kalman Filters for Time Delay of Arrival-Based Source Localization

NASA Astrophysics Data System (ADS)

Klee, Ulrich; Gehrig, Tobias; McDonough, John

2006-12-01

In this work, we propose an algorithm for acoustic source localization based on time delay of arrival (TDOA) estimation. In earlier work by other authors, an initial closed-form approximation was first used to estimate the true position of the speaker followed by a Kalman filtering stage to smooth the time series of estimates. In the proposed algorithm, this closed-form approximation is eliminated by employing a Kalman filter to directly update the speaker's position estimate based on the observed TDOAs. In particular, the TDOAs comprise the observation associated with an extended Kalman filter whose state corresponds to the speaker's position. We tested our algorithm on a data set consisting of seminars held by actual speakers. Our experiments revealed that the proposed algorithm provides source localization accuracy superior to the standard spherical and linear intersection techniques. Moreover, the proposed algorithm, although relying on an iterative optimization scheme, proved efficient enough for real-time operation.

STRONG LENS TIME DELAY CHALLENGE. I. EXPERIMENTAL DESIGN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dobler, Gregory; Fassnacht, Christopher D.; Rumbaugh, Nicholas

2015-02-01

The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters. The number of lenses with measured time delays is growing rapidly; the upcoming Large Synoptic Survey Telescope (LSST) will monitor ∼10{sup 3} strongly lensed quasars. In an effort to assess the present capabilities of the community, to accurately measure the time delays, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we have invited the community to take part in a ''Time Delay Challenge'' (TDC). The challenge is organized as a set of ''ladders'', each containing a groupmore » of simulated data sets to be analyzed blindly by participating teams. Each rung on a ladder consists of a set of realistic mock observed lensed quasar light curves, with the rungs' data sets increasing in complexity and realism. The initial challenge described here has two ladders, TDC0 and TDC1. TDC0 has a small number of data sets, and is designed to be used as a practice set by the participating teams. The (non-mandatory) deadline for completion of TDC0 was the TDC1 launch date, 2013 December 1. The TDC1 deadline was 2014 July 1. Here we give an overview of the challenge, we introduce a set of metrics that will be used to quantify the goodness of fit, efficiency, precision, and accuracy of the algorithms, and we present the results of TDC0. Thirteen teams participated in TDC0 using 47 different methods. Seven of those teams qualified for TDC1, which is described in the companion paper.« less

Factors associated with pathways toward concurrent sex work and injection drug use among female sex workers who inject drugs in northern Mexico.

PubMed

Morris, Meghan D; Lemus, Hector; Wagner, Karla D; Martinez, Gustavo; Lozada, Remedios; Gómez, Rangel María Gudelia; Strathdee, Steffanie A

2013-01-01

To identify factors associated with time to initiation of (i) sex work prior to injecting drugs initiation; (ii) injection drug use prior to sex work initiation; and (iii) concurrent sex work and injection drug use (i.e. initiated at the same age) among female sex workers who currently inject drugs (FSW-IDU). Parametric survival analysis of baseline data for time to initiation event. Tijuana and Ciudad Juarez situated on the Mexico-US border. A total of 557 FSW-IDUs aged ≥18 years. Interview-administered surveys assessing context of sex work and injection drug use initiation. Nearly half (n = 258) initiated sex work prior to beginning to inject, a third (n = 163) initiated injection first and a quarter (n = 136) initiated both sex work and injection drug use concurrently. Low education and living in Ciudad Juarez accelerated time to sex work initiation. Being from a southern Mexican state and initiating drug use with inhalants delayed the time to first injection drug use. Having an intimate partner encourage entry into sex work and first injecting drugs to deal with depression accelerated time to initiating sex work and injection concurrently. Early physical abuse accelerated time to initiating sex work and injection, and substantially accelerated time to initiation of both behaviors concurrently. Among female sex workers who currently inject drugs in two Mexican-US border cities, nearly half appear to initiate sex work prior to beginning to inject, nearly one-third initiate injection drug use before beginning sex work and one-quarter initiate both behaviors concurrently. Predictors of these three trajectories differ, and this provides possible modifiable targets for prevention. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

Clinical efficacy of dim light melatonin onset testing in diagnosing delayed sleep phase syndrome.

PubMed

Rahman, Shadab A; Kayumov, Leonid; Tchmoutina, Ekaterina A; Shapiro, Colin M

2009-05-01

Delayed Sleep Phase Syndrome (DSPS) arises from biological clock desynchrony and accounts for 10% of chronic insomnia patients. Currently DSPS is diagnosed based on sleep/wake cycle disruptions rather than examining the underlying biological clock alterations. The objective of the study was to determine the sensitivity and specificity of the Dim Light Melatonin Onset (DLMO) Test in diagnosing DSPS in a clinical setting. Fifty-six patients (mean age 28 years) symptomatic of DSPS participated in the study. Following an initial assessment of DSPS using sleep diaries, participants underwent two consecutive nights of polysomnography (PSG), with an imposed sleep period on the second night to demonstrate the delay in the timing of habitual sleep period and to thereby confirm DSPS. Circadian phase delays were also measured using melatonin secretion profiles, and the efficacy of diagnosing DSPS using DLMO was compared to using sleep diaries and PSG. Melatonin secretion was assayed for each individual by ELISA using saliva samples. Main outcome measures included the time of melatonin secretion onset, clinical sensitivity and specificity of the DLMO test. The time of melatonin secretion onset was significantly delayed in DSPS patients. Clinical sensitivity and specificity of the DLMO test in diagnosing DSPS were 90.3% and 84.0%, respectively. The DLMO test is an accurate tool for differentiating between sleep disorder patients with or without underlying circadian rhythm disruption. It is effective for phase typing DSPS patients in a clinical setting.

Radiation from lightning return strokes over a finitely conducting earth

NASA Technical Reports Server (NTRS)

Le Vine, D. M.; Gesell, L.; Kao, Michael

1986-01-01

The effects of the conductivity of the earth on radiation from lightning return strokes are examined theoretically using a piecewise linear transmission line model for the return stroke. First, calculations are made of the electric field radiated during the return stroke, and then this electric field is used to compute the response of conventional AM radio receivers and electric field change systems during the return stroke. The calculations apply to the entire transient waveform (they are not restricted to the initial portions of the return stroke) and yield fast field changes and RF radiation in agreement with measurements made during real lightning. This research was motivated by measurements indicating that a time delay exists between the time of arrival of the fast electric field change and the RF radiation from first return strokes. The time delay is on the order of 20 microsec for frequencies in the HF-UHF range for lightning in Florida. The time delay is obtained theoretically in this paper. It occurs when both the effects of attenuation due to conductivity of the earth, and the finite velocity of propagation of the current pulse up the return stroke channel, are taken into account in the model.

Selectivity of Electronic Coherence and Attosecond Ionization Delays in Strong-Field Double Ionization

NASA Astrophysics Data System (ADS)

Kobayashi, Yuki; Reduzzi, Maurizio; Chang, Kristina F.; Timmers, Henry; Neumark, Daniel M.; Leone, Stephen R.

2018-06-01

Experiments are presented on real-time probing of coherent electron dynamics in xenon initiated by strong-field double ionization. Attosecond transient absorption measurements allow for characterization of electronic coherences as well as relative ionization timings in multiple electronic states of Xe+ and Xe2 + . A high degree of coherence g =0.4 is observed between P3 2 0-P3 0 0 of Xe2 + , whereas for other possible pairs of states the coherences are below the detection limits of the experiments. A comparison of the experimental results with numerical simulations based on an uncorrelated electron-emission model shows that the coherences produced by strong-field double ionization are more selective than predicted. Surprisingly short ionization time delays, 0.85 fs, 0.64 fs, and 0.75 fs relative to Xe+ formation, are also measured for the P2 3 , P0 3 , and P1 3 states of Xe2 + , respectively. Both the unpredicted selectivity in the formation of coherence and the subfemtosecond time delays of specific states provide new insight into correlated electron dynamics in strong-field double ionization.

Hydrogen and Ethene Plasma Assisted Ignition by NS discharge at Elevated Temperatures

NASA Astrophysics Data System (ADS)

Starikovskiy, Andrey

2015-09-01

The kinetics of ignition in lean H2:O2:Ar and C2H4:O2:Ar mixtures has been studied experimentally and numerically after a high-voltage nanosecond discharge. The ignition delay time behind a reflected shock wave was measured with and without the discharge. It was shown that the initiation of the discharge with a specific deposited energy of 10 - 30 mJ/cm3 leads to an order of magnitude decrease in the ignition delay time. Discharge processes and following chain chemical reactions with energy release were simulated. The generation of atoms, radicals and excited and charged particles was numerically simulated using the measured time - resolved discharge current and electric field in the discharge phase. The calculated densities of the active particles were used as input data to simulate plasma-assisted ignition. Good agreement was obtained between the calculated ignition delay times and the experimental data. It follows from the analysis of the calculated results that the main mechanism of the effect of gas discharge on the ignition of hydrocarbons is the electron impact dissociation of O2 molecules in the discharge phase. Detailed kinetic mechanism for plasma assisted ignition of hydrogen and ethene is elaborated and verified.

New insight into the residual inactivation of Microcystis aeruginosa by dielectric barrier discharge

PubMed Central

Li, Lamei; Zhang, Hong; Huang, Qing

2015-01-01

We report the new insight into the dielectric barrier discharge (DBD) induced inactivation of Microcystis aeruginosa, the dominant algae which caused harmful cyanobacterial blooms in many developing countries. In contrast with the previous work, we employed flow cytometry to examine the algal cells, so that we could assess the dead and living cells with more accuracy, and distinguish an intermediate state of algal cells which were verified as apoptotic. Our results showed that the numbers of both dead and apoptotic cells increased with DBD treatment delay time, and hydrogen peroxide produced by DBD was the main reason for the time-delayed inactivation effect. However, apart from the influence of hydrogen peroxide, the DBD-induced initial injures on the algal cells during the discharge period also played a considerable role in the inactivation of the DBD treated cells, as indicated by the measurement of intracellular reactive oxygen species (ROS) inside the algal cells. We therefore propose an effective approach to utilization of non-thermal plasma technique that makes good use of the residual inactivation effect to optimize the experimental conditions in terms of discharge time and delay time, so that more efficient treatment of cyanobacterial blooms can be achieved. PMID:26347270

Will changes in phenology track climate change? A study of growth initiation timing in coast Douglas-fir.

PubMed

Ford, Kevin R; Harrington, Constance A; Bansal, Sheel; Gould, Peter J; St Clair, J Bradley

2016-11-01

Under climate change, the reduction of frost risk, onset of warm temperatures and depletion of soil moisture are all likely to occur earlier in the year in many temperate regions. The resilience of tree species will depend on their ability to track these changes in climate with shifts in phenology that lead to earlier growth initiation in the spring. Exposure to warm temperatures ('forcing') typically triggers growth initiation, but many trees also require exposure to cool temperatures ('chilling') while dormant to readily initiate growth in the spring. If warming increases forcing and decreases chilling, climate change could maintain, advance or delay growth initiation phenology relative to the onset of favorable conditions. We modeled the timing of height- and diameter-growth initiation in coast Douglas-fir (an ecologically and economically vital tree in western North America) to determine whether changes in phenology are likely to track changes in climate using data from field-based and controlled-environment studies, which included conditions warmer than those currently experienced in the tree's range. For high latitude and elevation portions of the tree's range, our models predicted that warming will lead to earlier growth initiation and allow trees to track changes in the onset of the warm but still moist conditions that favor growth, generally without substantially greater exposure to frost. In contrast, toward lower latitude and elevation range limits, the models predicted that warming will lead to delayed growth initiation relative to changes in climate due to reduced chilling, with trees failing to capture favorable conditions in the earlier parts of the spring. This maladaptive response to climate change was more prevalent for diameter-growth initiation than height-growth initiation. The decoupling of growth initiation with the onset of favorable climatic conditions could reduce the resilience of coast Douglas-fir to climate change at the warm edges of its distribution. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Will changes in phenology track climate change? A study of growth initiation timing in coast Douglas-fir

USGS Publications Warehouse

Ford, Kevin R.; Harrington, Constance A.; Bansal, Sheel; Gould, Petter J.; St. Clair, Bradley

2016-01-01

Under climate change, the reduction of frost risk, onset of warm temperatures and depletion of soil moisture are all likely to occur earlier in the year in many temperate regions. The resilience of tree species will depend on their ability to track these changes in climate with shifts in phenology that lead to earlier growth initiation in the spring. Exposure to warm temperatures (“forcing”) typically triggers growth initiation, but many trees also require exposure to cool temperatures (“chilling”) while dormant to readily initiate growth in the spring. If warming increases forcing and decreases chilling, climate change could maintain, advance or delay growth initiation phenology relative to the onset of favorable conditions. We modeled the timing of height- and diameter-growth initiation in coast Douglas-fir (an ecologically and economically vital tree in western North America) to determine whether changes in phenology are likely to track changes in climate using data from field-based and controlled-environment studies, which included conditions warmer than those currently experienced in the tree's range. For high latitude and elevation portions of the tree's range, our models predicted that warming will lead to earlier growth initiation and allow trees to track changes in the onset of the warm but still moist conditions that favor growth, generally without substantially greater exposure to frost. In contrast, towards lower latitude and elevation range limits, the models predicted that warming will lead to delayed growth initiation relative to changes in climate due to reduced chilling, with trees failing to capture favorable conditions in the earlier parts of the spring. This maladaptive response to climate change was more prevalent for diameter-growth initiation than height-growth initiation. The decoupling of growth initiation with the onset of favorable climatic conditions could reduce the resilience of coast Douglas-fir to climate change at the warm edges of its distribution.

Time series analyses of breathing patterns of lung cancer patients using nonlinear dynamical system theory.

PubMed

Tewatia, D K; Tolakanahalli, R P; Paliwal, B R; Tomé, W A

2011-04-07

The underlying requirements for successful implementation of any efficient tumour motion management strategy are regularity and reproducibility of a patient's breathing pattern. The physiological act of breathing is controlled by multiple nonlinear feedback and feed-forward couplings. It would therefore be appropriate to analyse the breathing pattern of lung cancer patients in the light of nonlinear dynamical system theory. The purpose of this paper is to analyse the one-dimensional respiratory time series of lung cancer patients based on nonlinear dynamics and delay coordinate state space embedding. It is very important to select a suitable pair of embedding dimension 'm' and time delay 'τ' when performing a state space reconstruction. Appropriate time delay and embedding dimension were obtained using well-established methods, namely mutual information and the false nearest neighbour method, respectively. Establishing stationarity and determinism in a given scalar time series is a prerequisite to demonstrating that the nonlinear dynamical system that gave rise to the scalar time series exhibits a sensitive dependence on initial conditions, i.e. is chaotic. Hence, once an appropriate state space embedding of the dynamical system has been reconstructed, we show that the time series of the nonlinear dynamical systems under study are both stationary and deterministic in nature. Once both criteria are established, we proceed to calculate the largest Lyapunov exponent (LLE), which is an invariant quantity under time delay embedding. The LLE for all 16 patients is positive, which along with stationarity and determinism establishes the fact that the time series of a lung cancer patient's breathing pattern is not random or irregular, but rather it is deterministic in nature albeit chaotic. These results indicate that chaotic characteristics exist in the respiratory waveform and techniques based on state space dynamics should be employed for tumour motion management.

Role of peripheral reflexes in the initiation of the esophageal phase of swallowing

PubMed Central

Medda, Bidyut K.; Babaei, Arash; Shaker, Reza

2014-01-01

The aim of this study was to determine the role of peripheral reflexes in initiation of the esophageal phase of swallowing. In 10 decerebrate cats, we recorded electromyographic responses from the pharynx, larynx, and esophagus and manometric data from the esophagus. Water (1–5 ml) was injected into the nasopharynx to stimulate swallowing, and the timing of the pharyngeal and esophageal phases of swallowing was quantified. The effects of transection or stimulation of nerves innervating the esophagus on swallowing and esophageal motility were tested. We found that the percent occurrence of the esophageal phase was significantly related to the bolus size. While the time delays between the pharyngeal and esophageal phases of swallowing were not related to the bolus size, they were significantly more variable than the time delays between activation of muscles within the pharyngeal phase. Transection of the sensory innervation of the proximal cervical esophagus blocked or significantly inhibited activation of the esophageal phase in the proximal cervical esophagus. Peripheral electrical stimulation of the pharyngoesophageal nerve activated the proximal cervical esophagus, peripheral electrical stimulation of the vagus nerve activated the distal cervical esophagus, and peripheral electrical stimulation the superior laryngeal nerve (SLN) had no effect on the esophagus. Centripetal electrical stimulation of the SLN activated the cervical component of the esophageal phase of swallowing before initiation of the pharyngeal phase. Therefore, we concluded that initiation of the esophageal phase of swallowing depends on feedback from peripheral reflexes acting through the SLN, rather than a central program. PMID:24557762

Periodic protein adsorption at the gold/biotin aqueous solution interface: evidence of kinetics with time delay

NASA Astrophysics Data System (ADS)

Neff, H.; Laborde, H. M.; Lima, A. M. N.

2016-11-01

An oscillatory molecular adsorption pattern of the protein neutravidin from aqueous solution onto gold, in presence of a pre-deposited self assembled mono-molecular biotin film, is reported. Real time surface Plasmon resonance sensing was utilized for evaluation of the adsorption kinetics. Two different fractions were identified: in the initial phase, protein molecules attach irreversibly onto the Biotin ligands beneath towards the jamming limit, forming a neutravidin-biotin fraction. Afterwards, the growth rate exhibits distinct, albeit damped adsorption-desorption oscillations over an extended time span, assigned to a quasi reversibly bound fraction. These findings agree with, and firstly confirm a previously published model, proposing macro-molecular adsorption with time delay. The non-linear dynamic model is applicable to and also resembles non-damped oscillatory binding features of the hetero-catalytic oxidation of carbon monoxide molecules on platinum in the gas phase. An associated surface residence time can be linked to the dynamics and time scale required for self-organization.

Improving the timeliness of procedures in a pediatric endoscopy suite.

PubMed

Tomer, Gitit; Choi, Steven; Montalvo, Andrea; Sutton, Sheila; Thompson, John; Rivas, Yolanda

2014-02-01

Pediatric endoscopic procedures are essential in the evaluation and treatment of gastrointestinal diseases in children. Although pediatric endoscopists are greatly interested in increasing efficiency and through-put in pediatric endoscopy units, there is scarcely any literature on this critical process. The goal of this study was to improve the timeliness of pediatric endoscopy procedures at Children's Hospital at Montefiore. In June 2010, a pediatric endoscopy quality improvement initiative was formed at Children's Hospital at Montefiore. We identified patient-, equipment-, and physician-related causes for case delays. Pareto charts, cause and effect diagrams, process flow mapping, and statistical process control charts were used for analysis. From June 2010 to December 2012, we were able to significantly decrease the first case endoscopy delay from an average of 17 to 10 minutes (P < .001), second case delay from 39 to 25 minutes (P = .01), third case delay from 61 to 45 minutes (P = .05), and fourth case delay from 79 to 51 minutes (P = .05). Total delay time decreased from 196 to 131 minutes, resulting in a reduction of 65 minutes (P = .02). From June 2010 to August 2011 (preintervention period), an average of 36% of first endoscopy cases started within 5 minutes, 51% within 10 minutes, and 61% within 15 minutes of the scheduled time. From September 2011 to December 2012 (postintervention period), the percentage of cases starting within 5 minutes, 10 minutes, and 15 minutes increased to 47% (P = .07), 61% (P = .04), and 79% (P = .01), respectively. Applying quality improvement methods and tools helped improve pediatric endoscopy timeliness and significantly decreased total delays.

Factors associated with pathways toward concurrent sex work and injection drug use among female sex workers who inject drugs in Northern Mexico

PubMed Central

Morris, Meghan D.; Lemus, Hector; Wagner, Karla D.; Martinez, Gustavo; Lozada, Remedios; Gómez, Rangel María Gudelia; Strathdee, Steffanie A.

2012-01-01

Aims To identify factors associated with time to initiation of (1) sex work prior to injecting drugs, (2) injection drug use, and (3) concurrent sex work and injection drug use (i.e., initiated at the same age) among female sex workers who currently inject drugs (FSW-IDU). Design Parametric survival analysis of baseline data for time to initiation event. Setting Tijuana and Ciudad Juarez situated on the Mexico-U.S. border. Participants 575 FSW-IDUs aged ≥18. Measurements Interview-administered surveys assessing context of sex work and injection drug use initiation. Findings Nearly half (n=256) initiated sex work prior to beginning to inject, a third (n=163) initiated injection first, and a quarter (n=136) initiated both sex work and injection drug use concurrently. Low education and living in Ciudad Juarez accelerated time to sex work initiation. Being from a southern Mexican state and initiating drug use with inhalants delayed the time to first injection drug use. Having an intimate partner encourage entry into sex work and first injecting drugs to deal with depression accelerated time to initiating sex work and injection concurrently. Early physical abuse accelerated time to initiating sex work and injection, and substantially accelerated time to initiation of both behaviors concurrently. Conclusions Among female sex workers who currently inject drugs in two Mexican-US border cities, nearly half appear to initiate sex work prior to beginning to inject, nearly one third initiate injection drug use before beginning sex work, and one quarter initiate both behaviors concurrently. Predictors of these three trajectories differ, and this provides possible modifiable targets for prevention. PMID:22775475

Neurokinin B is critical for normal timing of sexual maturation but dispensable for adult reproductive function in female mice.

PubMed

True, Cadence; Nasrin Alam, Sayeda; Cox, Kimberly; Chan, Yee-Ming; Seminara, Stephanie B

2015-04-01

Humans carrying mutations in neurokinin B (NKB) or the NKB receptor fail to undergo puberty due to decreased secretion of GnRH. Despite this pubertal delay, many of these patients go on to achieve activation of their hypothalamic-pituitary-gonadal axis in adulthood, a phenomenon termed reversal, indicating that NKB signaling may play a more critical role for the timing of pubertal development than adult reproductive function. NKB receptor-deficient mice are hypogonadotropic but have no defects in the timing of sexual maturation. The current study has performed the first phenotypic evaluation of mice bearing mutations in Tac2, the gene encoding the NKB ligand, to determine whether they have impaired sexual development similar to their human counterparts. Male Tac2-/- mice showed no difference in the timing of sexual maturation or fertility compared with wild-type littermates and were fertile. In contrast, Tac2-/- females had profound delays in sexual maturation, with time to vaginal opening and first estrus occurring significantly later than controls, and initial abnormalities in estrous cycles. However, cycling recovered in adulthood and Tac2-/- females were fertile, although they produced fewer pups per litter. Thus, female Tac2-/- mice parallel humans harboring NKB pathway mutations, with delayed sexual maturation and activation of the reproductive cascade later in life. Moreover, direct comparison of NKB ligand and receptor-deficient females confirmed that only NKB ligand-deficient animals have delayed sexual maturation, suggesting that in the absence of the NKB receptor, NKB may regulate the timing of sexual maturation through other tachykinin receptors.

A Study on Health Seeking Behaviors of Patients of Post-Kala-Azar Dermal Leishmaniasis.

PubMed

Basher, Ariful; Nath, Proggananda; Nabi, Shah Golam; Selim, Shahjada; Rahman, Md Fashiur; Sutradhar, Satya Ranjan; Faiz, Abul; Bhuiyan, Matiur Rahman; Ahmed, Be-Nazir; Rahman, Ridwanur

2015-01-01

Post-Kala-Azar Dermal Leishmaniasis (PKDL) remains a major public health threat in Bangladesh. A cross-sectional study was carried out in Surya Kanta Kala azar Research Centre (SKKRC), Mymensingh, from January 2012 to July 2013 to evaluate the health seeking behaviour and the length of delay of PKDL management. The consecutive 200 diagnosed PKDL cases that got treatment in SKKRC hospital were subjected to evaluation. Most (98%) of the patients were not aware and had no knowledge about PKDL, though 87.5% had a history of history of Kala-azar treatment. Many patients reported first to village doctor (15.5%), the pharmacy shop (10%), or traditional health provider (7.5%) upon recognition of symptom. The time between the initial symptom recognition and first medical consultation (patient delay) ranged from 10 days to 4745 days (13 years) with a median of 373 days (mean: 696; IQR: 138 to 900 days). The time between first medical consultations to definite treatment (system delay) ranged from 0 days to 1971 days (5.4 years), with a median delay of 14 days (mean: 46.48; IQR: 7 to 44 days) that was reported in this study. Age, education, occupation, and residential status had significant association with patient delay (P < 0.05). Educational status, occupation, number of treatment providers, and first health care provider had a significant association with system delay (P < 0.05). Success in PKDL diagnosis and treatment requires specific behavior from patients and health care providers which facilitate those practices.

Use of complementary and alternative medicines is associated with delay to initiation of disease-modifying anti-rheumatic drug therapy in early inflammatory arthritis.

PubMed

Lahiri, Manjari; Santosa, Amelia; Teoh, Lay Kheng; Clayton, Jane A; Lim, Sheen Yee; Teng, Gim Gee; Cheung, Peter P M

2017-05-01

To study the predictors of complementary and alternative medicine (CAM) use in patients with early inflammatory arthritis (EIA), and its impact on delay to initiation of disease-modifying anti-rheumatic drugs (DMARD). Data were collected prospectively from EIA patients aged ≥ 21 years. Current or prior CAM use was ascertained by face-to-face interview. Predictors of CAM use and its effect on time to DMARD initiation were determined by multivariate logistic regression and Cox proportional hazards, respectively. One hundred and eighty patients (70.6% female, 58.3% Chinese), of median (interquartile range [IQR]) age 51.1 (40.9-59.8) years and symptom duration 16.6 (9.2-26.6) weeks were included: 83.9% had rheumatoid arthritis, 57% were seropositive. Median (IQR) Disease Activity Score in 28-joints (DAS28) was 4.3 (2.8-5.7), modified Health Assessment Questionnaire (mHAQ) was 0.38 (0.0-0.88) and 41.3% were CAM users. Chinese race (odds ratio [OR] 5.76 [95%CI 2.53-13.1]), being non-English speaking (OR 2.68 [95% CI 1.18-6.09]), smoking (OR 3.35 [95% CI 1.23-9.15] and high DAS28 (OR 2.73 [95% CI 1.05-7.09] were independent predictors of CAM use. CAM users initiated DMARD later (median [IQR] 21.5 [13.1-30.4] vs. 15.6 [9.4-22.7] weeks in non-users, P = 0.005). CAM use and higher DAS28 were associated with a longer delay to DMARD initiation (hazard ratio [HR] 0.69, 95% CI 0.50-0.95 and 0.63, 95% CI 0.43-0.91, respectively) while higher mHAQ was associated with a shorter delay (HR 1.59, 95% CI 1.08-2.34) and race, education level, being non-English speaking, smoking and seropositivity were not associated. Healthcare professionals should be aware of the unique challenges in treating patients with EIA in Asia. Healthcare beliefs regarding CAM may need to be addressed to reduce treatment delay. © 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

Estimating the state of a geophysical system with sparse observations: time delay methods to achieve accurate initial states for prediction

DOE PAGES

An, Zhe; Rey, Daniel; Ye, Jingxin; ...

2017-01-16

The problem of forecasting the behavior of a complex dynamical system through analysis of observational time-series data becomes difficult when the system expresses chaotic behavior and the measurements are sparse, in both space and/or time. Despite the fact that this situation is quite typical across many fields, including numerical weather prediction, the issue of whether the available observations are "sufficient" for generating successful forecasts is still not well understood. An analysis by Whartenby et al. (2013) found that in the context of the nonlinear shallow water equations on a β plane, standard nudging techniques require observing approximately 70 % of themore » full set of state variables. Here we examine the same system using a method introduced by Rey et al. (2014a), which generalizes standard nudging methods to utilize time delayed measurements. Here, we show that in certain circumstances, it provides a sizable reduction in the number of observations required to construct accurate estimates and high-quality predictions. In particular, we find that this estimate of 70 % can be reduced to about 33 % using time delays, and even further if Lagrangian drifter locations are also used as measurements.« less

Estimating the state of a geophysical system with sparse observations: time delay methods to achieve accurate initial states for prediction

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, Zhe; Rey, Daniel; Ye, Jingxin

The problem of forecasting the behavior of a complex dynamical system through analysis of observational time-series data becomes difficult when the system expresses chaotic behavior and the measurements are sparse, in both space and/or time. Despite the fact that this situation is quite typical across many fields, including numerical weather prediction, the issue of whether the available observations are "sufficient" for generating successful forecasts is still not well understood. An analysis by Whartenby et al. (2013) found that in the context of the nonlinear shallow water equations on a β plane, standard nudging techniques require observing approximately 70 % of themore » full set of state variables. Here we examine the same system using a method introduced by Rey et al. (2014a), which generalizes standard nudging methods to utilize time delayed measurements. Here, we show that in certain circumstances, it provides a sizable reduction in the number of observations required to construct accurate estimates and high-quality predictions. In particular, we find that this estimate of 70 % can be reduced to about 33 % using time delays, and even further if Lagrangian drifter locations are also used as measurements.« less

Airport Surface Delays and Causes: A Preliminary Analysis

NASA Technical Reports Server (NTRS)

Chin, David K.; Goldberg, Jay; Tang, Tammy

1997-01-01

This report summarizes FAA Program Analysis and Operations Research Service (ASD-400)/Lockheed Martin activities and findings related to airport surface delays and causes, in support of NASA Langley Research Center's Terminal Area Productivity (TAP) Program. The activities described in this report were initiated in June 1995. A preliminary report was published on September 30, 1995. The final report incorporates data collection forms filled out by traffic managers, other FAA staff, and an airline for the New York City area, some updates, data previously requested from various sources to support this analysis, and further quantification and documentation than in the preliminary report. This final report is based on data available as of April 12, 1996. This report incorporates data obtained from review and analysis of data bases and literature, discussions/interviews with engineers, air-traffic staff, other FAA technical personnel, and airline staff, site visits, and a survey on surface delays and causes. It includes analysis of delay statistics; preliminary findings and conclusions on surface movement, surface delay sources and causes, runway occupancy time (ROT), and airport characteristics impacting surface operations and delays; and site-specific data on the New York City area airports, which are the focus airports for this report.

Transient-Switch-Signal Suppressor

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1995-01-01

Circuit delays transmission of switch-opening or switch-closing signal until after preset suppression time. Used to prevent transmission of undesired momentary switch signal. Basic mode of operation simple. Beginning of switch signal initiates timing sequence. If switch signal persists after preset suppression time, circuit transmits switch signal to external circuitry. If switch signal no longer present after suppression time, switch signal deemed transient, and circuit does not pass signal on to external circuitry, as though no transient switch signal. Suppression time preset at value large enough to allow for damping of underlying pressure wave or other mechanical transient.

Performance on a strategy set shifting task during adolescence in a genetic model of attention deficit/hyperactivity disorder: Methylphenidate vs. atomoxetine treatments

PubMed Central

Harvey, Roxann C; Jordan, Chloe J; Tassin, David H; Moody, Kayla R; Dwoskin, Linda P; Kantak, Kathleen M

2013-01-01

Research examining medication effects on set shifting in teens with attention deficit/hyperactivity disorder (ADHD) is lacking. An animal model of ADHD may be useful for exploring this gap. The Spontaneously Hypertensive Rat (SHR) is a commonly used animal model of ADHD. SHR and two comparator strains, Wistar-Kyoto (WKY) and Wistar (WIS), were evaluated during adolescence in a strategy set shifting task under conditions of a 0-sec or 15-sec delay to reinforcer delivery. The task had three phases: initial discrimination, set shift and reversal learning. Under 0-sec delays, SHR performed as well as or better than WKY and WIS. Treatment with 0.3 mg/kg/day atomoxetine had little effect, other than to modestly increase trials to criterion during set shifting in all strains. Under 15-sec delays, SHR had longer lever press reaction times, longer latencies to criterion and more trial omissions than WKY during set shifting and reversal learning. These deficits were not reduced systematically by 1.5 mg/kg/day methylphenidate or 0.3 mg/kg/day atomoxetine. Regarding learning in SHR, methylphenidate improved initial discrimination, whereas atomoxetine improved set shifting but disrupted initial discrimination. During reversal learning, both drugs were ineffective in SHR, and atomoxetine made reaction time and trial omissions greater in WKY. Overall, WIS performance differed from SHR or WKY, depending on phase. Collectively, a genetic model of ADHD in adolescent rats revealed that neither methylphenidate nor atomoxetine mitigated all deficits in SHR during the set shifting task. Thus, methylphenidate or atomoxetine monotherapy may not mitigate all set shift task-related deficits in teens with ADHD. PMID:23376704

Arabidopsis AGAMOUS Regulates Sepal Senescence by Driving Jasmonate Production

PubMed Central

Jibran, Rubina; Tahir, Jibran; Cooney, Janine; Hunter, Donald A.; Dijkwel, Paul P.

2017-01-01

The signal that initiates the age-regulated senescence program in flowers is still unknown. Here we propose for the ephemeral Arabidopsis thaliana flower that it dies because of continued expression of the MADS-box transcription factor AGAMOUS (AG). AG is necessary for specifying the reproductive structures of the flower. Flowers of ag-1, which lack AG, exhibited delayed sepal senescence and abscission. The flowers also had reduced jasmonic acid (JA) content. Other anther-defective sterile mutants deficient in JA, defective in anther dehiscence 1 (dad1) and delayed dehiscence 2 (dde2), exhibited delayed sepal senescence and abscission as well. Manually pollinated dad1 flowers produced siliques but still had delayed senescence, demonstrating that absence of pollination does not cause delayed senescence. When ag-1, dad1 and dde2 flowers were sprayed with 100 μM methyl jasmonate, the sepal senescence and abscission phenotypes were rescued, suggesting that JA has a role in these processes. Our study uncovers a novel role for AG in determining the timing of death of the flower it helps develop and highlights a role for JA in sepal senescence. PMID:29312374

Stress Wave Interaction Between Two Adjacent Blast Holes

NASA Astrophysics Data System (ADS)

Yi, Changping; Johansson, Daniel; Nyberg, Ulf; Beyglou, Ali

2016-05-01

Rock fragmentation by blasting is determined by the level and state of stress in the rock mass subjected to blasting. With the application of electronic detonators, some researchers stated that it is possible to achieve improved fragmentation through stress wave superposition with very short delay times. This hypothesis was studied through theoretical analysis in the paper. First, the stress in rock mass induced by a single-hole shot was analyzed with the assumptions of infinite velocity of detonation and infinite charge length. Based on the stress analysis of a single-hole shot, the stress history and tensile stress distribution between two adjacent holes were presented for cases of simultaneous initiation and 1 ms delayed initiation via stress superposition. The results indicated that the stress wave interaction is local around the collision point. Then, the tensile stress distribution at the extended line of two adjacent blast holes was analyzed for a case of 2 ms delay. The analytical results showed that the tensile stress on the extended line increases due to the stress wave superposition under the assumption that the influence of neighboring blast hole on the stress wave propagation can be neglected. However, the numerical results indicated that this assumption is unreasonable and yields contrary results. The feasibility of improving fragmentation via stress wave interaction with precise initiation was also discussed. The analysis in this paper does not support that the interaction of stress waves improves the fragmentation.

Ultrafast isomerization initiated by X-ray core ionization

NASA Astrophysics Data System (ADS)

Liekhus-Schmaltz, Chelsea E.; Tenney, Ian; Osipov, Timur; Sanchez-Gonzalez, Alvaro; Berrah, Nora; Boll, Rebecca; Bomme, Cedric; Bostedt, Christoph; Bozek, John D.; Carron, Sebastian; Coffee, Ryan; Devin, Julien; Erk, Benjamin; Ferguson, Ken R.; Field, Robert W.; Foucar, Lutz; Frasinski, Leszek J.; Glownia, James M.; Gühr, Markus; Kamalov, Andrei; Krzywinski, Jacek; Li, Heng; Marangos, Jonathan P.; Martinez, Todd J.; McFarland, Brian K.; Miyabe, Shungo; Murphy, Brendan; Natan, Adi; Rolles, Daniel; Rudenko, Artem; Siano, Marco; Simpson, Emma R.; Spector, Limor; Swiggers, Michele; Walke, Daniel; Wang, Song; Weber, Thorsten; Bucksbaum, Philip H.; Petrovic, Vladimir S.

2015-09-01

Rapid proton migration is a key process in hydrocarbon photochemistry. Charge migration and subsequent proton motion can mitigate radiation damage when heavier atoms absorb X-rays. If rapid enough, this can improve the fidelity of diffract-before-destroy measurements of biomolecular structure at X-ray-free electron lasers. Here we study X-ray-initiated isomerization of acetylene, a model for proton dynamics in hydrocarbons. Our time-resolved measurements capture the transient motion of protons following X-ray ionization of carbon K-shell electrons. We Coulomb-explode the molecule with a second precisely delayed X-ray pulse and then record all the fragment momenta. These snapshots at different delays are combined into a `molecular movie' of the evolving molecule, which shows substantial proton redistribution within the first 12 fs. We conclude that significant proton motion occurs on a timescale comparable to the Auger relaxation that refills the K-shell vacancy.

The Initiation of Smooth Pursuit is Delayed in Anisometropic Amblyopia

PubMed Central

Raashid, Rana Arham; Liu, Ivy Ziqian; Blakeman, Alan; Goltz, Herbert C.; Wong, Agnes M. F.

2016-01-01

Purpose Several behavioral studies have shown that the reaction times of visually guided movements are slower in people with amblyopia, particularly during amblyopic eye viewing. Here, we tested the hypothesis that the initiation of smooth pursuit eye movements, which are responsible for accurately keeping moving objects on the fovea, is delayed in people with anisometropic amblyopia. Methods Eleven participants with anisometropic amblyopia and 14 visually normal observers were asked to track a step-ramp target moving at ±15°/s horizontally as quickly and as accurately as possible. The experiment was conducted under three viewing conditions: amblyopic/nondominant eye, binocular, and fellow/dominant eye viewing. Outcome measures were smooth pursuit latency, open-loop gain, steady state gain, and catch-up saccade frequency. Results Participants with anisometropic amblyopia initiated smooth pursuit significantly slower during amblyopic eye viewing (206 ± 20 ms) than visually normal observers viewing with their nondominant eye (183 ± 17 ms, P = 0.002). However, mean pursuit latency in the anisometropic amblyopia group during binocular and monocular fellow eye viewing was comparable to the visually normal group. Mean open-loop gain, steady state gain, and catch-up saccade frequency were similar between the two groups, but participants with anisometropic amblyopia exhibited more variable steady state gain (P = 0.045). Conclusions This study provides evidence of temporally delayed smooth pursuit initiation in anisometropic amblyopia. After initiation, the smooth pursuit velocity profile in anisometropic amblyopia participants is similar to visually normal controls. This finding differs from what has been observed previously in participants with strabismic amblyopia who exhibit reduced smooth pursuit velocity gains with more catch-up saccades. PMID:27070109

A randomized controlled trial on providing ankle-foot orthoses in patients with (sub-)acute stroke: Short-term kinematic and spatiotemporal effects and effects of timing.

PubMed

Nikamp, Corien D M; Hobbelink, Marte S H; van der Palen, Job; Hermens, Hermie J; Rietman, Johan S; Buurke, Jaap H

2017-06-01

Initial walking function is often limited after stroke, and regaining walking ability is an important goal in rehabilitation. Various compensatory movement strategies to ensure sufficient foot-clearance are reported. Ankle-foot orthoses (AFOs) are often prescribed to improve foot-clearance and may influence these strategies. However, research studying effects of actual AFO-provision early after stroke is limited. We conducted an explorative randomized controlled trial and aimed to study the short-term effects of AFO-provision on kinematic and spatiotemporal parameters in patients early after stroke. In addition, we studied whether timing of AFO-provision influenced these effects. Unilateral hemiparetic patients maximal six weeks post-stroke were randomly assigned to AFO-provision: early (at inclusion) or delayed (eight weeks later). Three-dimensional gait-analysis with and without AFO in randomized order was performed within two weeks after AFO-provision. Twenty subjects (8 early, 12 delayed) were analyzed. We found significant positive effects of AFO-provision for ankle dorsiflexion at initial contact, foot-off and during swing (-3.6° (7.3) vs 3.0° (3.9); 0.0° (7.4) vs 5.2° (3.7); and -6.1° (7.8) vs 2.6° (3.5), respectively), all p<0.001. No changes in knee, hip and pelvis angles were found after AFO-provision, except for knee (+2.3°) and hip flexion (+1.6°) at initial contact, p≤0.001. Significant effects of AFO-provision were found for cadence (+2.1 steps/min, p=0.026), stride duration (-0.08s, p=0.015) and single support duration (+1.0%, p=0.002). Early or delayed AFO-provision after stroke did not affect results. In conclusion, positive short-term effects of AFO-provision were found on ankle kinematics early after stroke. Timing of AFO-provision did not influence the results. NTR1930. Copyright © 2017 Elsevier B.V. All rights reserved.

Errors in Postural Preparation Lead to Increased Choice Reaction Times for Step Initiation in Older Adults

PubMed Central

Nutt, John G.; Horak, Fay B.

2011-01-01

Background. This study asked whether older adults were more likely than younger adults to err in the initial direction of their anticipatory postural adjustment (APA) prior to a step (indicating a motor program error), whether initial motor program errors accounted for reaction time differences for step initiation, and whether initial motor program errors were linked to inhibitory failure. Methods. In a stepping task with choice reaction time and simple reaction time conditions, we measured forces under the feet to quantify APA onset and step latency and we used body kinematics to quantify forward movement of center of mass and length of first step. Results. Trials with APA errors were almost three times as common for older adults as for younger adults, and they were nine times more likely in choice reaction time trials than in simple reaction time trials. In trials with APA errors, step latency was delayed, correlation between APA onset and step latency was diminished, and forward motion of the center of mass prior to the step was increased. Participants with more APA errors tended to have worse Stroop interference scores, regardless of age. Conclusions. The results support the hypothesis that findings of slow choice reaction time step initiation in older adults are attributable to inclusion of trials with incorrect initial motor preparation and that these errors are caused by deficits in response inhibition. By extension, the results also suggest that mixing of trials with correct and incorrect initial motor preparation might explain apparent choice reaction time slowing with age in upper limb tasks. PMID:21498431

Treatment delays among women with breast cancer in a low socio-economic status region in Brazil.

PubMed

Alves Soares Ferreira, Naidhia; Melo Figueiredo de Carvalho, Sionara; Engrácia Valenti, Vitor; Pinheiro Bezerra, Italla Maria; Melo Teixeira Batista, Hermes; de Abreu, Luiz Carlos; Matos, Leandro Luongo; Adami, Fernando

2017-02-21

Considering the inequalities and the areas of low socioeconomic status in Brazil, access to health services is a challenge and the delay between diagnosis and treatment represents an important factor of worse prognosis in patients with breast cancer. Herein, we describe the clinical and epidemiological profiles of women with breast cancer and evaluate their access to health services, as well as treatment delays, at a reference centre of the Cariri region, Ceará, Brazil. This is a retrospective study that included 473 women treated with breast cancer between 2009 and 2011 at the Oncology Centre of the Cariri. The majority of these patients were aged between 40 and 69 years old (65.7%), without a completed high school degree (89.2%). They were married (62.9%) and were already diagnosed but had not yet been subjected to any previous treatment (77.8%). It was observed that 91.8% were referred from the public health service, and treatment was paid for by the public health service in 92.9% of the cases. The patients whose source of referral was the public system waited longer between diagnosis and the treatment initiation (p = 0.031; Mann-Whitney's test), with a median waiting time of 71.5 days versus 39 days for those receiving referrals from private services. In addition, those with public referrals prior to diagnosis also experienced a longer waiting time between the first medical visit and treatment initiation (77 days vs. 37 days; p = 0.036; Mann-Whitney's test), with the waiting time for the biopsy being an important factor in this delay. Late diagnosis was often the result of inefficiency of the prevention policies coupled with difficulty accessing the public health network. It was commonly observed that, even after diagnosis, the patients needed to wait too long before entering the Oncology Service because of long waiting queues in the public health system.

Perceived Delay in Healthcare-seeking for Episodes of Serious Illness and Its Implications for Safe Motherhood Interventions in Rural Bangladesh

PubMed Central

Killewo, J.; Bashir, I.; Yunus, M.; Chakraborty, J.

2006-01-01

Delay in accessing emergency obstetric-care facilities during life-threatening obstetric complications is a significant determinant of high maternal mortality in developing countries. To examine the factors associated with delays in seeking care for episodes of serious illness and their possible implications for safe motherhood interventions in rural Bangladesh, a cross-sectional study was initiated in Matlab sub-district on the perceptions of household heads regarding delays in seeking care for episodes of serious illness among household members. Of 2,177 households in the study, 881 (40.5%) reported at least one household member who experienced an illness perceived to be serious enough to warrant care-seeking either from health facilities or from providers. Of these, 775 (88.0%) actually visited some providers for treatment, of whom 79.1% used transport. Overall, 69.3% perceived a delay in deciding to seek care, while 12.1% and 24.6% perceived a delay in accessing transport and in reaching the provider respectively. The median time required to make a decision to seek care was 72 minutes, while the same was 10 minutes to get transport and 80 minutes to reach a facility or a provider. Time to decide to seek care was shortest for pregnancy-related conditions and longest for illnesses classified as chronic, while time to reach a facility was longest for pregnancy-related illnesses and shortest for illnesses classified as acute. However, the perceived delay in seeking care did not differ significantly across socioeconomic levels or gender categories but differed significantly between those seeking care from informal providers compared to formal providers. Reasons for the delay included waiting time for results of informal treatment, inability to judge the graveness of disease, and lack of money. For pregnancy-related morbidities, 45% reported ‘inability to judge the graveness of the situation’ as a reason for delay in making decision. After controlling for possible confounders in multivariate analysis, type of illness and facility visited were the strongest determinants of delay in making decision to seek care. To reduce delays in making decision to seek care in rural Bangladesh, safe motherhood interventions should intensify behaviour change-communication efforts to educate communities to recognize pregnancy-danger signs for which a prompt action must be taken to save life. This strategy should be combined with efforts to train community-based skilled birth attendants, upgrading public facilities to provide emergency obstetric care, introduce voucher schemes to improve access by the poorest of the poor, and improve the quality of care at all levels. PMID:17591337

Triggered creep as a possible mechanism for delayed dynamic triggering of tremor and earthquakes

USGS Publications Warehouse

Shelly, David R.; Peng, Zhigang; Hill, David P.; Aiken, Chastity

2011-01-01

The passage of radiating seismic waves generates transient stresses in the Earth's crust that can trigger slip on faults far away from the original earthquake source. The triggered fault slip is detectable in the form of earthquakes and seismic tremor. However, the significance of these triggered events remains controversial, in part because they often occur with some delay, long after the triggering stress has passed. Here we scrutinize the location and timing of tremor on the San Andreas fault between 2001 and 2010 in relation to distant earthquakes. We observe tremor on the San Andreas fault that is initiated by passing seismic waves, yet migrates along the fault at a much slower velocity than the radiating seismic waves. We suggest that the migrating tremor records triggered slow slip of the San Andreas fault as a propagating creep event. We find that the triggered tremor and fault creep can be initiated by distant earthquakes as small as magnitude 5.4 and can persist for several days after the seismic waves have passed. Our observations of prolonged tremor activity provide a clear example of the delayed dynamic triggering of seismic events. Fault creep has been shown to trigger earthquakes, and we therefore suggest that the dynamic triggering of prolonged fault creep could provide a mechanism for the delayed triggering of earthquakes. ?? 2011 Macmillan Publishers Limited. All rights reserved.

Are We Doing Enough to Stem the Tide of Acquired MDR-TB in Countries with High TB Burden? Results of a Mixed Method Study in Chongqing, China

PubMed Central

Li, Ying; Ehiri, John; Oren, Eyal; Hu, Daiyu; Luo, Xingneng; Liu, Ying; Li, Daikun; Wang, Qingya

2014-01-01

Multi-drug resistant tuberculosis (MDR-TB) represents a threat to health and development in countries with high TB burden. China’s MDR-TB prevalence rate of 6.8% is the highest in the world. Interventions to remove barriers against effective TB control, and prevention of MDR-TB are urgently needed in the country. This paper reports a cross-sectional questionnaire survey of 513 pulmonary TB (PTB) patients, and qualitative interviews of 10 healthcare workers (HCWs), and 15 PTB patients. The objective was to assess barriers against effective control of PTB and prevention of MDR-TB by elucidating the perspectives of patients and healthcare providers. Results showed that more than half of the patients experienced patient delay of over 12.5 days. A similar proportion also experienced detection delay of over 30 days, and delay in initiating treatment of over 31 days. Consulting a non-TB health facility ≥3 times before seeking care at TB dispensary was a risk factor for both detection delay [AOR (95% CI): 1.89(1.07, 3.34) and delay in initiating treatment[AOR (95% CI): 1.88 (1.06, 3.36). Results revealed poor implementation of Directly Observed Therapy (DOT), whereby treatment of 34.3% patients was never monitored by HCWs. Only 31.8% patients had ever accessed TB health education before their TB diagnosis. Qualitative data consistently disclosed long patient delay, and indicated that patient’s poor TB knowledge and socioeconomic barriers were primary reasons for patient delay. Seeking care and being treated at a non-TB hospital was an important reason for detection delay. Patient’s long work hours and low income increased risk for treatment non-adherence. Evidence-based measures to improve TB health seeking behavior, reduce patient and detection delays, improve the quality of DOT, address financial and system barriers, and increase access to TB health promotion are urgently needed to address the burgeoning prevalence of MDR-TB in China. PMID:24505476

Tolerance to cocaine's effects on schedule-controlled behavior: role of delay between pause-ending responses and reinforcement.

PubMed

Macaskill, Anne C; Branch, Marc N

2012-01-01

The schedule of reinforcement under which behavior is maintained is an important contributor to whether tolerance to the behavioral effects of cocaine develops. Schedule parameter value (for example, fixed-ratio size) has been shown to affect the development of tolerance under some schedule types but not others, but the specific procedural variables causing this effect remain to be identified. To date, schedule-parameter-related tolerance has developed when a longer pause after reinforcement does not lead to a shorter delay between the response that ends the pause and reinforcement. The current study investigated the importance of this variable in pigeons using a multiple chained Fixed-Ratio 1, Fixed-Time x schedule, in which the first key peck in a trial produced a stimulus change and initiated a delay at the end of which food was presented regardless of whether or not additional pecks were made during the delay. Dose-response curves were assessed before, during and after chronic (daily) administration of cocaine. Tolerance to the pause-increasing effects of cocaine occurred to a similar degree regardless of the scheduled time between the end of the pause and reinforcement. Therefore, the relationship between pause length and delay to reinforcement does not provide an explanation for schedule-parameter-related tolerance. Copyright © 2011 Elsevier Inc. All rights reserved.

Automated Delay Measurement System for an Earth Station for Two-Way Satellite Time and Frequency Transfer

DTIC Science & Technology

1994-12-01

important for improving the TWSTFT capabilities. An automnted system for this purpose has been developed from the initial design at NMi-VSL. It...September 1994 together with a USNO portable station on a calibration trip to European TWSTFT earth staions. 1. Introduction The Two-Way Satellite...Time and Frequency Transfer ( TWSTFT ) method (Fig. I) is used to compare two clocks or time scales which are often located at great distances from each

A subanesthetic dose of ketamine in the Rhesus monkey reduces the occurrence of anticipatory saccades.

PubMed

Ameqrane, Ilhame; Ilhame, Ameqrane; Wattiez, Nicolas; Nicolas, Wattiez; Pouget, Pierre; Pierre, Pouget; Missal, Marcus; Marcus, Missal

2015-10-01

It has been shown that antagonism of the glutamatergic N-methyl-D-aspartate (NMDA) receptor with subanesthetic doses of ketamine perturbs the perception of elapsed time. Anticipatory eye movements are based on an internal representation of elapsed time. Therefore, the occurrence of anticipatory saccades could be a particularly sensitive indicator of abnormal time perception due to NMDA receptors blockade. The objective of this study was to determine whether the occurrence of anticipatory saccades could be selectively altered by a subanesthetic dose of ketamine. Three Rhesus monkeys were trained in a simple visually guided saccadic task with a variable delay. Monkeys were rewarded for making a visually guided saccade at the end of the delay. Premature anticipatory saccades to the future position of the eccentric target initiated before the end of the delay were not rewarded. A subanesthetic dose of ketamine (0.25 mg/kg) or a saline solution of the same volume was injected i.m. during the task. We found that the injected dose of ketamine did not induce sedation or abnormal behavior. However, in ∼4 min, ketamine induced a strong reduction of the occurrence of anticipatory saccades but did not reduce the occurrence of visually guided saccades. This unexpected reduction of anticipatory saccade occurrence could be interpreted as resulting from an altered use of the perception of elapsed time during the delay period induced by NMDA receptors antagonism.

Regional P-wave Tomography in the Caribbean Region for Plate Reconstruction

NASA Astrophysics Data System (ADS)

Li, X.; Bedle, H.; Suppe, J.

2017-12-01

The complex plate-tectonic interactions around the Caribbean Sea have been studied and interpreted by many researchers, but questions still remain regarding the formation and subduction history of the region. Here we report current progress towards creating a new regional tomographic model, with better lateral and spatial coverage and higher resolution than has been presented previously. This new model will provide improved constraints on the plate-tectonic evolution around the Caribbean Plate. Our three-dimensional velocity model is created using taut spline parameterization. The inversion is computed by the code of VanDecar (1991), which is based on the ray theory method. The seismic data used in this inversion are absolute P wave arrival times from over 700 global earthquakes that were recorded by over 400 near Caribbean stations. There are over 25000 arrival times that were picked and quality checked within frequency band of 0.01 - 0.6 Hz by using a MATLAB GUI-based software named Crazyseismic. The picked seismic delay time data are analyzed and compared with other studies ahead of doing the inversion model, in order to examine the quality of our dataset. From our initial observations of the delay time data, the more equalized the ray azimuth coverage, the smaller the deviation of the observed travel times from the theoretical travel time. Networks around the NE and SE side of the Caribbean Sea generally have better ray coverage, and smaller delay times. Specifically, seismic rays reaching SE Caribbean networks, such as XT network, generally pass through slabs under South American, Central American, Lesser Antilles, Southwest Caribbean, and the North Caribbean transform boundary, which leads to slightly positive average delay times. In contrast, the Puerto Rico network records seismic rays passing through regions that may lack slabs in the upper mantle and show slightly negative or near zero average delay times. These results agree with previous tomographic models. Based on our delay time observations, slabs and velocity structures near the East side of the Caribbean plate might be better imaged due to its denser ray coverage. More caution in selecting the seismic data for inversion on the west margin of Caribbean will be required to avoid possible smearing effects and artifacts from unequal ray path distributions.

Feasibility of rapid discharge after transoral robotic surgery of the oropharynx.

PubMed

Richmon, Jeremy D; Feng, Allen L; Yang, Wuyang; Starmer, Heather; Quon, Harry; Gourin, Christine G

2014-11-01

To investigate the use of an algorithm for rapid discharge after transoral robotic surgery (TORS) and its effect on postoperative complications. Retrospective cohort study. A retrospective analysis of TORS cases from September 2009 to February 2013 was conducted. The effect of patient and tumor characteristics on postoperative length of stay (LOS) and complications were analyzed. A total of 91 patients were included; 79 underwent TORS for malignancy and 12 for a benign process. The mean LOS was 1.51 days (range, 1-5 days) with a median of 1 day. The mean time to initiation of oral diet was 1.26 days (range, 1-7 days) with a median of 1 day. Eleven (12%) patients experienced one or more complications during their postoperative course. Multivariate analysis demonstrated a significant association between patient and procedure variables and postoperative complications. TORS base of tongue reduction for obstructive sleep apnea (OSA) was associated with a significantly greater mean incremental time to initiation of oral diet (1.0 days, 95% confidence interval [CI]: 0.4 to 1.7, P < .001). A significantly greater mean incremental LOS was observed for patients with advanced comorbidity and a delay in initiation of oral diet beyond 24 hours. Rapid initiation of oral diet and rapid discharge home is feasible and not associated with postoperative complications. Similarly, the performance of a concurrent neck dissection does not contribute to LOS or the development of postoperative complications. Patients undergoing TORS for OSA are at greater risk of delay in initiation of oral diet and increased LOS. 4 © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

The effect of the Xpert MTB/RIF test on the time to MDR-TB treatment initiation in a rural setting: a cohort study in South Africa's Eastern Cape Province.

PubMed

Iruedo, Joshua; O'Mahony, Don; Mabunda, Sikhumbuzo; Wright, Graham; Cawe, Busisiwe

2017-01-21

There are significant delays in initiation of multidrug-resistant tuberculosis (MDR -TB) treatment. The Xpert MTB/RIF test has been shown to reduce the time to diagnosis and treatment of MDR-TB predominantly in urban centres. This study describes the time to treatment of MDR-TB and the effect of Xpert MTB/RIF on time to treatment in a deprived rural area in South Africa. This was a retrospective cohort study analysing the medical records of patients diagnosed with MDR-TB in King Sabata Dalindyebo Sub-District between 2009 and 2014. Numerical data were reported using the Kruskal-Wallis and Wilcoxon sum rank tests and categorical data compared using the two-sample test of proportions. Of the 342 patients with MDR-TB identified, 285 were eligible for analysis, of whom 145 (61.4%) were HIV positive. The median time from sputum collection to MDR-TB diagnosis was 27 days (IQR: 2-45) and differed significantly between diagnostic modalities: Xpert MTB/RIF, 1 day (IQR: 1-4; n = 114: p < 0.0001); Line Probe Assay 12 days (IQR: 8-21; n = 28; p < 0.0001); and culture/phenotypic drug sensitivity testing 45 days (IQR: 39-59; n = 143: p < 0.0001). The time from diagnosis to treatment initiation was 14 days (IQR: 8-27) and did not differ significantly between diagnostic modality. The median time from sputum collection to treatment initiation was 49 days (IQR: 20-69) but differed significantly between diagnostic modalities: Xpert MTB/RIF, 18 days (IQR: 11-27; n = 114; p < 0.0001); Line Probe Assay 29 days (IQR: 14.5-53; n = 28; p < 0.0001); and culture/phenotypic drug sensitivity, 64 days (IQR: 50-103; n = 143: P < 0.0001). Age, sex and HIV status did not influence the time intervals. Xpert MTB/RIF significantly reduced the time to MDR-TB treatment in a deprived rural setting as a result of a reduced time to diagnosis. However, the national target of five days was not achieved. Further research is needed to explore and address programmatic and patient-related challenges contributing to delayed treatment initiation.

Delays in Initiation of Disease-Modifying Therapy in Rheumatoid Arthritis Patients: Data from a US-Based Registry.

PubMed

Pappas, Dimitrios A; Kent, Jeffrey D; Greenberg, Jeffrey D; Mason, Marc A; Kremer, Joel M; Holt, Robert J

2015-12-01

The goal of this study was to evaluate how frequently rheumatoid arthritis (RA) therapy is instituted promptly and to describe the characteristics of patients who are not treated early upon diagnosis. The percentage of patients who at the time of enrollment in the Corrona registry were not receiving any RA-directed therapy was evaluated and their characteristics were summarized. The time to subsequent initiation of any RA-directed therapy was also estimated. Among 35,485 patients enrolled in Corrona, 34,735 (97.9%) were on appropriate therapy for RA and 750 (2.1%) had no history of any RA-directed therapy at time of enrollment. Among patients without any history of RA-directed therapy, the overall disease duration was 5.5 ± 9.0 years, with only 50.7% of patients having early disease (duration ≤1 year). Patients with no history of directed RA therapy did not have lower disease activity at enrollment compared with those receiving therapy. Clinical Disease Activity Index (CDAI) was 18.3 ± 15.0; 34% of patients had high and 27.6% moderate disease activity by CDAI. Patients were followed for a median (95% CI) time of 29.5 months (24.6-33.8). During the follow-up period, 372 out of 750 (49.6%) patients initiated RA-directed therapy. The median time to initiation of any RA-directed therapy was 12.1 months (95% CI 9.3-14.8). In this registry analysis, approximately 98% of patients were on appropriate RA therapy for their RA. However, a minority of patients with RA did not have a history of receiving disease-modifying therapy within a mean of approximately 5 years of RA onset and approximately 50% of them did not initiate any therapy within 12 months of registry follow-up. This delay in therapy did not appear to be related to a better controlled, or lower, RA disease activity state at the time of enrollment in the registry. Corrona, LLC.

Can Anger Be Helpful?: Soldier Perceptions of the Utility of Anger.

PubMed

Adler, Amy B; Brossart, Daniel F; Toblin, Robin L

2017-09-01

Studies have found that soldiers returning from combat deployment report elevated levels of anger and aggression. The present study examined the perception that anger was helpful in performing occupationally related duties and whether this perception was associated with mental health problems, somatic symptoms, and functioning. Soldiers (N = 627) completed a survey 4 months after their deployment to Afghanistan and again 3 months later. When examining anger over time, findings revealed four groups of different latent classes: low stable (resilient), high stable (chronic), decreasing over time (improved), and increasing over time (delayed problems). For two of the groups (chronic and delayed problems), perceiving anger as helpful was closely related to anger reactions. Perceiving anger as helpful was also associated with worse mental health symptoms. Further work in understanding how to mitigate this positive perception of anger in prevention initiatives may be useful in addressing anger reactions.

Effect of time to initiation of postoperative radiation therapy on survival in surgically managed head and neck cancer.

PubMed

Graboyes, Evan M; Garrett-Mayer, Elizabeth; Ellis, Mark A; Sharma, Anand K; Wahlquist, Amy E; Lentsch, Eric J; Nussenbaum, Brian; Day, Terry A

2017-12-15

The objective of this study was to determine the effects of National Comprehensive Cancer Network (NCCN) guideline-adherent initiation of postoperative radiation therapy (PORT) and different time-to-PORT intervals on the overall survival (OS) of patients with head and neck squamous cell carcinoma (HNSCC). The National Cancer Data Base was reviewed for the period of 2006-2014, and patients with HNSCC undergoing surgery and PORT were identified. Kaplan-Meier survival estimates, Cox regression analysis, and propensity score matching were used to determine the effects of initiating PORT within 6 weeks of surgery and different time-to-PORT intervals on survival. This study included 41,291 patients. After adjustments for covariates, starting PORT >6 weeks postoperatively was associated with decreased OS (adjusted hazard ratio [aHR], 1.13; 99% confidence interval [CI], 1.08-1.19). This finding remained in the propensity score-matched subset (hazard ratio, 1.21; 99% CI, 1.15-1.28). In comparison with starting PORT 5 to 6 weeks postoperatively, initiating PORT earlier was not associated with improved survival (aHR for ≤ 4 weeks, 0.93; 99% CI, 0.85-1.02; aHR for 4-5 weeks, 0.92; 99% CI, 0.84-1.01). Increasing durations of delay beyond 7 weeks were associated with small, progressive survival decrements (aHR, 1.09, 1.10, and 1.12 for 7-8, 8-10, and >10 weeks, respectively). Nonadherence to NCCN guidelines for initiating PORT within 6 weeks of surgery was associated with decreased survival. There was no survival benefit to initiating PORT earlier within the recommended 6-week timeframe. Increasing durations of delay beyond 7 weeks were associated with small, progressive survival decrements. Cancer 2017;123:4841-50. © 2017 American Cancer Society. © 2017 American Cancer Society.

Lessons learned during implementation of therapeutic hypothermia for neonatal hypoxic ischemic encephalopathy in a regional transport program in Ontario

PubMed Central

Khurshid, Faiza; Lee, Kyong-Soon; McNamara, Patrick J; Whyte, Hilary; Mak, Wendy

2011-01-01

BACKGROUND: Therapeutic hypothermia (TH) is the first intervention to consistently show improved neurological outcomes in neonates with hypoxic ischemic encephalopathy (HIE). Since the recent introduction of TH for HIE in many centres, reviews of practices during the implementation of TH in Canada have not been published. OBJECTIVE: To determine if eligible neonates are being offered TH and to identify any barriers to the effective implementation of TH. METHODS: A retrospective review of neonates referred to a regional tertiary centre at a gestational age of 35 weeks or more with HIE was conducted. RESULTS: Among 41 neonates referred, 29 (71%) were eligible for TH; among eligible patients, five were moribund and excluded, and TH was initiated in 16 (67%) of the remaining 24. Reasons for not cooling in eight eligible patients included a delay in referral (n=5, median age at referral was 14 h) and a failure to recognize the severity of HIE (n=3). Among cooled patients, median times were the following: 116 min for age at referral; 80 min for time from referral to transport team arrival; and 358 min for age at initiation of cooling. Seven (44%) patients had cooling initiated after 6 h of age. CONCLUSION: A significant proportion of eligible patients were not offered TH, and in many cooled patients, initiation of cooling was delayed beyond the recommended 6 h. For eligible patients to benefit from TH, it is imperative that all birthing centres be made aware that TH is now widely available as an important treatment option, but also that TH is a time-sensitive therapy requiring rapid identification and referral. In the region studied, for eligible patients, referring hospitals should initiate passive cooling before arrival of the transport team. Referring hospitals should be prepared to provide early, yet safe initiation of passive cooling by having the appropriate equipment, and having staff trained in the use and monitoring of rectal temperatures. PMID:22379379

Indeterminate QuantiFERON-TB Gold Increases Likelihood of Inflammatory Bowel Disease Treatment Delay and Hospitalization.

PubMed

Vajravelu, Ravy K; Osterman, Mark T; Aberra, Faten N; Roy, Jason A; Lichtenstein, Gary R; Mamtani, Ronac; Goldberg, David S; Lewis, James D; Scott, Frank I

2017-12-19

QuantiFERON-TB Gold (QFTG) is a blood test used to diagnose latent tuberculosis infection (LTBI) prior to TNF-α inhibitor (anti-TNF) initiation. We sought to determine factors associated with indeterminate QFTG results in inflammatory bowel disease (IBD) patients and whether indeterminate results are associated with IBD-related morbidity. This nested case-control study included IBD patients who underwent QFTG testing. Cases were patients with indeterminate QFTG and controls were those with negative QFTG. The association of demographic and clinical data with indeterminate QFTG result was assessed using logistic regression. We examined the clinical impact of indeterminate QFTG results on risk of hospitalization and delay in anti-TNF initiation using inverse probability-of-treatment weighting (IPTW) regression. We identified 411 patients with QFTG testing (320 negative, 80 indeterminate, and 11 positive results). No patient with an indeterminate result subsequently had LTBI. Systemic corticosteroid use (OR, 4.4; 95% CI, 2.0-9.6) and hospitalization at the time of QFTG (OR, 3.8; 95% CI, 1.9-7.7) were associated with indeterminate QFTG, while immunomodulator use was nearly statistically significant (OR, 3.1; 95% CI, 0.9-9.8) and anti-TNF use was not (OR, 0.9; 95% CI, 0.2-4.6). After IPTW adjustment, indeterminate QFTG was associated with a 23.1% (95% CI, 8.2%-37.9%) greater probability of delay in anti-TNF initiation beyond 30 days and an 11.9% (95% CI, 0.6%-23.1%) greater probability of hospitalization within 60 days. Systemic corticosteroid use and hospitalization were associated with an indeterminate QFTG result. Indeterminate QFTG results were associated with delayed anti-TNF initiation and subsequent hospitalization. © 2017 Crohn’s & Colitis Foundation of America. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Delayed initiation of radiotherapy for glioblastoma: how important is it to push to the front (or the back) of the line?

PubMed

Lawrence, Yaacov Richard; Blumenthal, Deborah T; Matceyevsky, Diana; Kanner, Andrew A; Bokstein, Felix; Corn, Benjamin W

2011-10-01

Glioblastoma is a malignant tumor characterized by a rapid proliferation rate. Contemporary multi-modality treatment consists of maximal surgical resection followed by radiation therapy (RT) combined with cytotoxic chemotherapy. The optimal timing of these different steps is not known. Four studies from the pre-temozolomide era, encompassing a total of 4,584 subjects, have examined the consequences of a delay between resection and starting RT. Whereas the two small single-institution studies found this delay to be detrimental, two large multi-institutional studies found delay to be either slightly beneficial or at least not harmful. Here, we critically compare the methodologies and results presented in these studies, and include a novel analysis of the combined datasets. We conclude that moderate wait periods (up to 4-6 weeks post-operatively) are safe and may be modestly beneficial. Conversely, there is no evidence to justify waiting longer than 6 weeks. Underlying radiobiological principles are discussed.

Patterns of prospective memory impairment among individuals with depression: the influence of cue type and delay interval.

PubMed

Li, Yanqi Ryan; Weinborn, Michael; Loft, Shayne; Maybery, Murray

2013-07-01

The present study investigated the impact of cue type and delay interval on prospective memory performance in depressed, compared to non-depressed, individuals using a clinically relevant measure, the Memory for Intentions Screening Test. The depressed group demonstrated impaired performance on time-based, but not event-based, prospective memory tasks relative to the nondepressed group. The depressed group also demonstrated impaired prospective memory on tasks with longer delay intervals (15 min), but not on tasks with shorter delay intervals (2 min). These data support theoretical frameworks that posit that depression is associated with deficits in cognitive initiative (i.e., reduced ability to voluntarily direct attention to relevant tasks) and thus that depressed individuals are susceptible to poor performance on strategically demanding tasks. The results also raise multiple avenues for developing interventions (e.g., implementation intentions) to improve prospective memory performance among individuals with depression, with potential implications for medication and other treatment adherence.

Anisotropy modulations of femtosecond laser pulse induced periodic surface structures on silicon by adjusting double pulse delay.

PubMed

Han, Weina; Jiang, Lan; Li, Xiaowei; Wang, Qingsong; Li, Hao; Lu, YongFeng

2014-06-30

We demonstrate that the polarization-dependent anisotropy of the laser-induced periodic surface structure (LIPSS) on silicon can be adjusted by designing a femtosecond laser pulse train (800 nm, 50 fs, 1 kHz). By varying the pulse delay from 100 to 1600 fs within a double pulse train to reduce the deposited pulse energy, which weakens the directional surface plasmon polarition (SPP)-laser energy coupling based on the initial formed ripple structure, the polarization-dependent geometrical morphology of the LIPSS evolves from a nearly isotropic circular shape to a somewhat elongated elliptical shape. Meanwhile, the controllable anisotropy of the two-dimensional scanned-line widths with different directions is achieved based on a certain pulse delay combined with the scanning speed. This can effectively realize better control over large-area uniform LIPSS formation. As an example, we further show that the large-area LIPSS can be formed with different scanning times under different pulse delays.

Components of treatment delay in rheumatoid arthritis differ according to autoantibody status: validation of a single-centre observation using national audit data.

PubMed

Pratt, Arthur G; Lendrem, Dennis; Hargreaves, Ben; Aslam, Osman; Galloway, James B; Isaacs, John D

2016-10-01

To determine whether time to treatment following symptom onset differs between RA patients according to autoantibody status. A single-centre retrospective analysis of a UK early RA inception cohort was first undertaken to identify those components of the patient journey that differed by serological subtype. Data from a UK national audit of early inflammatory arthritis patients was accessed to replicate the key finding. A total of 173 RA patients were diagnosed over a 31-month period, of whom 80 (46%) were ACPA/RF double-seropositive (ACPA(+)/RF(+)), 53 (31%) ACPA(-)/RF(-), 17 (10%) ACPA(+)/RF(-) and 23 (13%) RF(+)/ACPA(-) Overall, ACPA(+)/RF(+) patients experienced significantly longer symptom duration before DMARD initiation. This was accounted for by delays in their presentation to primary care following symptom onset-a finding that was robustly confirmed in an independent dataset of 2192 UK early RA patients. In contrast, ACPA(-)/RF(-) patients were significantly more likely to experience delays in DMARD initiation after presenting to secondary care. Causes of treatment delays in early RA differ according to patients' autoantibody status. More insidious symptom onset and/or distinct health-seeking behaviours among ACPA(+)/RF(+) patients may contribute to late presentations in primary care, whereas ACPA(-)/RF(-) patients experience delayed diagnosis and treatment in secondary care. These observations inform the research agenda, potentially influencing the design of service delivery for early arthritis patients. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology.

Implications of delayed initiation of radiotherapy: accelerated repopulation after induction chemotherapy for stage III non-small cell lung cancer.

PubMed

Chen, Chien P; Weinberg, Vivian K; Jahan, Thierry M; Jablons, David M; Yom, Sue S

2011-11-01

For patients with stage III non-small cell lung cancer treated with induction chemotherapy (ICT), delayed initiation of subsequent radiotherapy (RT) may allow for repopulation in the interval between treatment modalities and during the early phase of RT. We quantified the impact of postinduction RT timing by evaluating the pace of tumor regrowth. Institutionally approved retrospective review identified 21 analyzable patients with stage III non-small cell lung cancer who had platinum-based ICT followed by RT+/- chemotherapy from 2002 to 2009. Radiographic response was determined by RECIST criteria and the volume of the single largest tumor mass on the pre-ICT, post-ICT, and RT-planning computed tomography scans. After ICT, the median percent volume change from pre-ICT baseline was -41% (range -86 to +86%). By the RT-planning computed tomography scan, the median percent volume change from the post-ICT timepoint was +40% (range -11 to +311%) and the median volume change was +20 ml (range -4 to 102 ml); these changes were significant (p = 0.0002). Similar results were seen for tumor diameter. A correlation was observed between the amount of delay and degree of regrowth for percent volume (p = 0.0006) and percent diameter change (p = 0.003). A delay greater than 21 days produced greater increases in percent volume change (p = 0.002) and percent diameter (p = 0.055) than lesser delays. After ICT, tumor regrowth can occur within a few weeks. Radiation treatment planning should begin as soon as possible after the administration of ICT to maximize the benefits of cytoreduction.

Watching proton transfer in real time: Ultrafast photoionization-induced proton transfer in phenol-ammonia complex cation.

PubMed

Shen, Ching-Chi; Tsai, Tsung-Ting; Wu, Jun-Yi; Ho, Jr-Wei; Chen, Yi-Wei; Cheng, Po-Yuan

2017-10-28

In this paper, we give a full account of our previous work [C. C. Shen et al., J. Chem. Phys. 141, 171103 (2014)] on the study of an ultrafast photoionization-induced proton transfer (PT) reaction in the phenol-ammonia (PhOH-NH 3 ) complex using ultrafast time-resolved ion photofragmentation spectroscopy implemented by the photoionization-photofragmentation pump-probe detection scheme. Neutral PhOH-NH 3 complexes prepared in a free jet are photoionized by femtosecond 1 + 1 resonance-enhanced multiphoton ionization via the S 1 state. The evolving cations are then probed by delayed pulses that result in ion fragmentation, and the ionic dynamics is followed by measuring the parent-ion depletion as a function of the pump-probe delay time. By comparing with systems in which PT is not feasible and the steady-state ion photofragmentation spectra, we concluded that the observed temporal evolutions of the transient ion photofragmentation spectra are consistent with an intracomplex PT reaction after photoionization from the initial non-PT to the final PT structures. Our experiments revealed that PT in [PhOH-NH 3 ] + cation proceeds in two distinct steps: an initial impulsive wave-packet motion in ∼70 fs followed by a slower relaxation of about 1 ps that stabilizes the system into the final PT configuration. These results indicate that for a barrierless PT system, even though the initial PT motions are impulsive and ultrafast, the time scale to complete the reaction can be much slower and is determined by the rate of energy dissipation into other modes.

Watching proton transfer in real time: Ultrafast photoionization-induced proton transfer in phenol-ammonia complex cation

NASA Astrophysics Data System (ADS)

Shen, Ching-Chi; Tsai, Tsung-Ting; Wu, Jun-Yi; Ho-Wei, Jr.; Chen, Yi-Wei; Cheng, Po-Yuan

2017-10-01

In this paper, we give a full account of our previous work [C. C. Shen et al., J. Chem. Phys. 141, 171103 (2014)] on the study of an ultrafast photoionization-induced proton transfer (PT) reaction in the phenol-ammonia (PhOH-NH3) complex using ultrafast time-resolved ion photofragmentation spectroscopy implemented by the photoionization-photofragmentation pump-probe detection scheme. Neutral PhOH-NH3 complexes prepared in a free jet are photoionized by femtosecond 1 + 1 resonance-enhanced multiphoton ionization via the S1 state. The evolving cations are then probed by delayed pulses that result in ion fragmentation, and the ionic dynamics is followed by measuring the parent-ion depletion as a function of the pump-probe delay time. By comparing with systems in which PT is not feasible and the steady-state ion photofragmentation spectra, we concluded that the observed temporal evolutions of the transient ion photofragmentation spectra are consistent with an intracomplex PT reaction after photoionization from the initial non-PT to the final PT structures. Our experiments revealed that PT in [PhOH-NH3]+ cation proceeds in two distinct steps: an initial impulsive wave-packet motion in ˜70 fs followed by a slower relaxation of about 1 ps that stabilizes the system into the final PT configuration. These results indicate that for a barrierless PT system, even though the initial PT motions are impulsive and ultrafast, the time scale to complete the reaction can be much slower and is determined by the rate of energy dissipation into other modes.

Spatial resolution in visual memory.

PubMed

Ben-Shalom, Asaf; Ganel, Tzvi

2015-04-01

Representations in visual short-term memory are considered to contain relatively elaborated information on object structure. Conversely, representations in earlier stages of the visual hierarchy are thought to be dominated by a sensory-based, feed-forward buildup of information. In four experiments, we compared the spatial resolution of different object properties between two points in time along the processing hierarchy in visual short-term memory. Subjects were asked either to estimate the distance between objects or to estimate the size of one of the objects' features under two experimental conditions, of either a short or a long delay period between the presentation of the target stimulus and the probe. When different objects were referred to, similar spatial resolution was found for the two delay periods, suggesting that initial processing stages are sensitive to object-based properties. Conversely, superior resolution was found for the short, as compared with the long, delay when features were referred to. These findings suggest that initial representations in visual memory are hybrid in that they allow fine-grained resolution for object features alongside normal visual sensitivity to the segregation between objects. The findings are also discussed in reference to the distinction made in earlier studies between visual short-term memory and iconic memory.

Self-ignition of S.I. engine model fuels: A shock tube investigation at high pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fieweger, K.; Blumenthal, R.; Adomeit, G.

1997-06-01

The self-ignition of several spark-ignition (SI) engine fuels (iso-octane, methanol, methyl tert-butyl ether and three different mixtures of iso-octane and n-heptane), mixed with air, was investigated experimentally under relevant engine conditions by the shock tube technique. Typical modes of the self-ignition process were registered cinematographically. For temperatures relevant to piston engine combustion, the self-ignition process always starts as an inhomogeneous, deflagrative mild ignition. This instant is defined by the ignition delay time, {tau}{sub defl}. The deflagration process in most cases is followed by a secondary explosion (DDT). This transition defines a second ignition delay time, {tau}{sub DDT}, which is amore » suitable approximation for the chemical ignition delay time, if the change of the thermodynamic conditions of the unburned test gas due to deflagration is taken into account. For iso-octane at p = 40 bar, a NTC (negative temperature coefficient), behavior connected with a two step (cool flame) self-ignition at low temperatures was observed. This process was very pronounced for rich and less pronounced for stoichiometric mixtures. The results of the {tau}{sub DDT} delays of the stoichiometric mixtures were shortened by the primary deflagration process in the temperature range between 800 and 1,000 K. Various mixtures of iso-octane and n-heptane were investigated. The results show a strong influence of the n-heptane fraction in the mixture, both on the ignition delay time and on the mode of self-ignition. The self-ignition of methanol and MTBE (methyl tert-butyl ether) is characterized by a very pronounced initial deflagration. For temperatures below 900 K (methanol: 800 K), no secondary explosion occurs. Taking into account the pressure increase due to deflagration, the measured delays {tau}{sub DDT} of the secondary explosion are shortened by up to one order of magnitude.« less

Delayed diagnosis of injuries in pediatric trauma: the role of radiographic ordering practices.

PubMed

Willner, Emily L; Jackson, Hollie A; Nager, Alan L

2012-01-01

We sought to describe the use of radiographic studies in pediatric major trauma patients and determine the extent to which a selective, clinically guided use of imaging contributes to delayed diagnosis of injury (DDI). We conducted a retrospective chart review of 324 consecutive pediatric major trauma patients at our level 1 trauma center. One radiologist reviewed all imaging. Delayed diagnosis of injury was defined as detection after more than 12 hours. Equivalency testing was performed to compare radiology use in patients with and without DDI. Twenty-six (8%) of 324 patients had 36 DDI; 27 (75%) of 36 were orthopedic injuries. Median time to DDI detection was 20.5 hours (interquartile range, 15-60.5). During initial evaluation, DDI patients had similar numbers of plain radiographs (3.5 vs 3, P = .54) but more computed tomographic (CT) scans (4 vs 3, P = .03) compared with patients without DDI. Sixteen percent of all patients received CT thorax; 55%, CT cervical spine; and 56%, CT abdomen. Only 1 clinically important DDI was detected solely on the basis of a later CT scan (0.3%; 95% confidence interval, 0-1.5). No cervical spine, intrathoracic, or intraabdominal DDI was attributable to failure to obtain a CT during initial evaluation. Patients with DDI had higher injury severity scores, intubation rates, and pediatric intensive care unit admission rates than those without DDI. Patients with DDI had similar initial plain x-ray evaluations to patients without DDI, despite DDI patients being more severely injured. Delayed diagnosis of injury was not attributable to inadequate CT use. Most DDIs were orthopedic, highlighting the importance of a tertiary survey and a low threshold for skeletal radiographs. Copyright © 2012 Elsevier Inc. All rights reserved.

Referral-free health care and delay in diagnosis for lung cancer patients.

PubMed

Hsieh, Vivian Chia-Rong; Wu, Trong-Neng; Liu, Shu-Hui; Shieh, Shwn-Huey

2012-10-01

Lung cancer is not only one of the most prevalent cancers but is also a lethal disease with a very low 5-year survival rate. Delay in diagnosis further reduces the chance of early treatment and worsens patients' survival. The purpose of this study was to understand the delay in the diagnosis of lung cancer under the healthcare system in Taiwan, and to identify the factors associated with it. A total of 840 patients diagnosed with lung cancer who had completed or were undergoing cancer treatments were recruited from a medical center in central Taiwan from July 2007 to January 2011. Structured questionnaires were administered regarding demographic characteristics, factors associated with their time to diagnosis and the length of delay in days. Mean age was 62.68 years with 52.16 days to diagnosis on average. Number of hospital visits before confirmation of diagnosis differed significantly with the level of healthcare institution initially visited (P < 0.001). Compared with patients who had three or more hospital visits, patients who only visited two and one hospital(s) had a significant 34.91-day (95% confidence interval: 16.29-53.53) and 42.25-day (95% confidence interval: 20.76-63.76) reduction in their time to diagnosis (P < 0.001). As the number of hospital visits increased, the delay in diagnosis also increased. It is vital to shorten the time to diagnosis for lung cancer patients by limiting the number of medical visits and educating the public to restrict excessive use of medical resources and strengthen their trust in medical professionals.

Referral and timing of referral to hospice care in nursing homes: the significant role of staff members.

PubMed

Welch, Lisa C; Miller, Susan C; Martin, Edward W; Nanda, Aman

2008-08-01

Given concerns about end-of-life care for many nursing home (NH) residents, this study sought to understand factors influencing hospice referral or nonreferral as well as timing of referral. We conducted semistructured interviews with personnel from seven participating NHs and two hospices. We interviewed NH directors of nursing regarding facility referral practices and conducted interviews with 34 NH nurses, 30 NH aides, and 17 hospice nurses knowledgeable about the factors that led to the hospice status of 32 NH decedents. Selected decedents varied by diagnosis and hospice status (received hospice for >7 days,

Diagnosis delay in Libyan female breast cancer

PubMed Central

2012-01-01

Aims To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. Methods 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008–2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time) was categorized into 3 periods: <3 months, 3–6 months, and >6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay). Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire) during an interview with each patient and from medical records. Results The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3–6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer) was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s) that did not include a lump (p < 0.0001), with women who did not report monthly self examination (p < 0.0001), with old age (p = 0.004), with illiteracy (p = 0.009), with history of benign fibrocystic disease (p = 0.029) and with women who had used oral contraceptive pills longer than 5 years (p = 0.043). At the time of diagnosis, the clinical stage distribution was as follows: 9.0% stage I, 25.5% stage II, 54.0% stage III and 11.5% stage IV. Diagnosis delay was associated with bigger tumour size (p <0.0001), with positive lymph nodes (N2, N3; p < 0.0001), with high incidence of late clinical stages (p < 0.0001), and with metastatic disease (p < 0.0001). Conclusions Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast cancer. Especially, guidelines for good practices in managing detectable of tumors are necessary. PMID:22909280

Diagnosis delay in Libyan female breast cancer.

PubMed

Ermiah, Eramah; Abdalla, Fathi; Buhmeida, Abdelbaset; Larbesh, Entesar; Pyrhönen, Seppo; Collan, Yrjö

2012-08-21

To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008-2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time) was categorized into 3 periods: <3 months, 3-6 months, and >6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay). Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire) during an interview with each patient and from medical records. The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3-6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer) was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s) that did not include a lump (p < 0.0001), with women who did not report monthly self examination (p < 0.0001), with old age (p = 0.004), with illiteracy (p = 0.009), with history of benign fibrocystic disease (p = 0.029) and with women who had used oral contraceptive pills longer than 5 years (p = 0.043). At the time of diagnosis, the clinical stage distribution was as follows: 9.0% stage I, 25.5% stage II, 54.0% stage III and 11.5% stage IV.Diagnosis delay was associated with bigger tumour size (p <0.0001), with positive lymph nodes (N2, N3; p < 0.0001), with high incidence of late clinical stages (p < 0.0001), and with metastatic disease (p < 0.0001). Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast cancer. Especially, guidelines for good practices in managing detectable of tumors are necessary.

Contingency Tracking during Unsignaled Delayed Reinforcement

ERIC Educational Resources Information Center

Keely, Josue; Feola, Tyler; Lattal, Kennon A.

2007-01-01

Three experiments were conducted with rats in which responses on one lever (labeled the functional lever) produced reinforcers after an unsignaled delay period that reset with each response during the delay. Responses on a second, nonfunctional, lever did not initiate delays, but, in the first and third experiments, such responses during the last…

Stability of equations with a distributed delay, monotone production and nonlinear mortality

NASA Astrophysics Data System (ADS)

Berezansky, Leonid; Braverman, Elena

2013-10-01

We consider population dynamics models dN/dt = f(N(tτ)) - d(N(t)) with an increasing fecundity function f and any mortality function d which can be quadratic, as in the logistic equation, or have a different form provided that the equation has at most one positive equilibrium. Here the delay in the production term can be distributed and unbounded. It is demonstrated that the positive equilibrium is globally attractive if it exists, otherwise all positive solutions tend to zero. Moreover, we demonstrate that solutions of the equation are intrinsically non-oscillatory: once the initial function is less/greater than the equilibrium K > 0, so is the solution for any positive time value. The assumptions on f, d and the delay are rather nonrestrictive, and several examples demonstrate that none of them can be omitted.

Initial 60Fe Abundance in the Solar Nebula Constrained by Delayed Onset of a Planetesimal Dynamo

NASA Astrophysics Data System (ADS)

Wang, H.; Weiss, B. P.; Crowley, J.

2017-12-01

The paleomagnetism of meteorites provides evidence for advecting metallic core dynamos and large-scale differentiation on their parent planetesimals. Their small sizes relative to planets enable new opportunities to understand the physics of dynamo generation. Wang et al. [2017] studied the paleomagnetism of three volcanic angrites (D'Orbigny, 4563.37±0.12 Ma; Sahara 99555, 4563.54±0.14 Ma; Asuka 881371, 4562.4±1.6 Ma) and one plutonic angrite (Angra dos Reis, 4556.51±0.11 Ma). Their results show that the older volcanic angrites recorded no detectable paleomagnetic field, while the younger plutonic angrite recorded a paleomagnetic field of 17 µT interpreted as evidence of a core dynamo on the angrite parent body (APB). This indicates that the initiation of the APB dynamo was delayed until sometime between 4 and 11 My after the formation of calcium aluminum-rich inclusions (CAIs) at 4567.30 ± 0.16 Ma. This late timing is consistent with recent planetesimal thermal evolution models invoking shallow magma oceans [Neumann et al. 2014], which predict that planetesimal dynamos would not initiate until the core began to crystallize. It is also consistent with thermal evolution models invoking large-scale magma oceans that considered thermal blanketing of the core by 26Al decay in the mantle [Roberts et al. 2013, Sterenborg and Crowley 2013], which would delay thermal convection dynamos until several My after accretion (occurred <0.25 My after CAIs for the APB [Schiller et al. 2015]) and differentiation. Because the presence of even a small amount of 60Fe in the core could effectively remove the thermal blanketing effect of mantle 26Al, we can use the delay in timing of the dynamo to constrain the abundance of 60Fe on the APB. Our planetesimal thermal evolution models show that if the initial solar nebula 60Fe/56Fe ratio was greater than 5×10-9, the APB core dynamo would have to start earlier than 4 My after CAIs, in contradiction to the paleomagnetic constraints. Thus, we argue that 5×10-9 is an upper limit of the initial 60Fe/56Fe ratio in the solar nebula. This upper limit is consistent with independent isotopic measurements of the Sahara 99555 angrite, which found 60Fe/56Fe ratio of (6.96 ± 1.60)×10-9 [Tang and Dauphas, 2015].

Separation dynamics of the COMET FreeFlyer and an upper stage STAR-48V motor

NASA Technical Reports Server (NTRS)

Fuller, Kevin M.; Myers, Carter H.

1993-01-01

In this report, the orbital separation between a STAR-48V upperstage motor and the COMET FreeFlyer is investigated. The time from nominal STAR-48 engine burnout is to be determined such that the STAR-48 will not collide with the FreeFlyer once the separation process has been initiated. To analyze this separation, the forces acting upon both the FreeFlyer and the STAR-48 are described in a body fixed coordinate system. These coordinates are then transformed into an Euler coordinate system and then further transformed into a relative inertial coordinate system. From this analysis and some basic assumptions about the Star-48/FreeFlyer vehicle, it can be concluded that the STAR-48 will not collide with the Free Flyer if the separation occurs at 120 seconds after nominal burnout of the STAR-48. In fact, the separation delay could be a shorter period of time, but it is recommended that this separation delay be as long as possible for risk mitigation. This delay is currently designed to be 120 seconds and the analysis presented in this report shows that this time is acceptable.

House Wrens adjust laying dates and clutch size in relation to annual flooding

Treesearch

Deborah M. Finch

1991-01-01

I examined timing of reproduction and productivity in box-nesting House Wrens (Troglodytes aedon) inhabiting three riverbank woodlands subjected to different levels of flooding. In years when the North Platte River flooded its banks submerging ground foraging substrates, dates of nest initiation and egg laying in two wren populations were delayed and nonsynchronized....

Greenhouse gas emissions during composting of dairy manure: Delaying pile mixing does not reduce overall emissions

USDA-ARS?s Scientific Manuscript database

The effect of the timing of pile mixing on greenhouse gas (GHG) emissions during dairy manure composting was determined using large flux chambers designed to completely cover replicate pilot-scale compost piles. GHG emissions from compost piles that were mixed at 2, 3, 4, or 5 weeks after initial c...

Improving the Enterprise Requirements and Acquisition Model’s Developmental Test and Evaluation Process Fidelity

DTIC Science & Technology

2014-03-27

and excluded from the model. The “Check SVR Loop” prevents programs from failing the SVR a second time. If a program has not previously failed the SVR...and Acquisition Management Plan Initiative. Briefing, Peterson AFB, CO: HQ AFSPC/A5X, 2011. Gilmore, Michael J., Key Issues Causing Prgram Delays

Initiation and Generalization of Self-Instructional Skills in Adolescents with Autism and Intellectual Disability

ERIC Educational Resources Information Center

Smith, Katherine A.; Ayres, Kevin A.; Alexander, Jennifer; Ledford, Jennifer R.; Shepley, Collin; Shepley, Sally B.

2016-01-01

Self-instruction using videos or other supports on a mobile device is a pivotal skill and can increase independence for individuals with disabilities by decreasing a need for adult supports. This study evaluated the effects of progressive time delay (PTD) to teach four adolescents with autism and intellectual disability how to initiate…

Time to first take-back operation predicts successful primary fascial closure in patients undergoing damage control laparotomy.

PubMed

Pommerening, Matthew J; DuBose, Joseph J; Zielinski, Martin D; Phelan, Herb A; Scalea, Thomas M; Inaba, Kenji; Velmahos, George C; Whelan, James F; Wade, Charles E; Holcomb, John B; Cotton, Bryan A

2014-08-01

Failure to achieve primary fascial closure (PFC) after damage control laparotomy is costly and carries great morbidity. We hypothesized that time from the initial laparotomy to the first take-back operation would be predictive of successful PFC. Trauma patients managed with open abdominal techniques after damage control laparotomy were prospectively followed at 14 Level 1 trauma centers during a 2-year period. Time to the first take-back was evaluated as a predictor of PFC using hierarchical multivariate logistic regression analysis. A total of 499 patients underwent damage control laparotomy and were included in this analysis. PFC was achieved in 327 (65.5%) patients. Median time to the first take-back operation was 36 hours (interquartile range 24-48). After we adjusted for patient demographics, resuscitation volumes, and operative characteristics, increasing time to the first take-back was associated with a decreased likelihood of PFC. Specifically, each hour delay in return to the operating room (24 hours after initial laparotomy) was associated with a 1.1% decrease in the odds of PFC (odds ratio 0.989; 95% confidence interval 0.978-0.999; P = .045). In addition, there was a trend towards increased intra-abdominal complications in patients returning after 48 hours (odds ratio 1.80; 95% confidence interval 1.00-3.25; P = .05). Data from this prospective, multicenter study demonstrate that delays in returning to the operating room after damage control laparotomy are associated with reductions in PFC. These findings suggest that emphasis should be placed on returning to the operating room within 24 hours after the initial laparotomy if possible (and no later than 48 hours). Copyright © 2014 Mosby, Inc. All rights reserved.

45 CFR 2105.3 - Action on initial requests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... sound grounds. (b) Determination will be dispatched within ten days, excluding Saturdays, Sundays, and... initial determination on requests may be delayed up to a total of ten additional days, excluding Saturdays, Sundays, and legal public holidays and notice of such delay shall be dispatched within the first ten days...

Computer modelling of anthelmintic resistance and worm control outcomes for refugia-based nematode control strategies in Merino ewes in Western Australia.

PubMed

Cornelius, M P; Jacobson, C; Dobson, R; Besier, R B

2016-04-15

This study utilised computer simulation modelling (Risk Management Model for Nematodes) to investigate the impact of different parasite refugia scenarios on the development of anthelmintic resistance and worm control effectiveness. The simulations were conducted for adult ewe flocks in a Mediterranean climatic region over a 20 year time period. Factors explored in the simulation exercise were environment (different weather conditions), drug efficacy, the percentage of the flock left untreated, the timing of anthelmintic treatments, the initial worm egg count, and the number of drenches per annum. The model was run with variable proportions of the flock untreated (0, 10, 20, 30, 40 and 50%), with ewes selected at random so that reductions in the mean worm burden or egg count were proportional to the treated section of the flock. Treatments to ewes were given either in summer (December; low refugia potential, hence highly selective) or autumn (March; less selective due to a greater refugia potential), and the use of different anthelmintics was simulated to indicate the difference between active ingredients of different efficacy. Each model scenario was run for two environments, specifically a lower rainfall area (more selective) and a higher rainfall area (less selective) within a Mediterranean climatic zone, characterised by hot, dry summers and cool, wet winters. Univariate general linear models with least square difference post-hoc tests were used to examine differences between means of factors. The results confirmed that leaving a proportion of sheep in a flock untreated was effective in delaying the development of anthelmintic resistance, with as low as 10% of a flock untreated sufficient to significantly delay resistance, although this strategy was associated with a small reduction in worm control. Administering anthelmintics in autumn rather than summer was also effective in delaying the development of anthelmintic resistance in the lower rainfall environment where all sheep were treated, although the effect of treatment timing on worm control effectiveness varied between the environments and the proportion of ewes left untreated. The use of anthelmintics with higher efficacy delayed the development of resistance, but the initial worm egg count or number of annual treatments had no effect on either the time to resistance development or worm control effectiveness. In conclusion, the modelling study suggests that leaving a small proportion of ewes untreated, or changing the time of treatment, can delay the onset of anthelmintic resistance in a highly selective environment. Copyright © 2016 Elsevier B.V. All rights reserved.

IRB Process Improvements: A Machine Learning Analysis.

PubMed

Shoenbill, Kimberly; Song, Yiqiang; Cobb, Nichelle L; Drezner, Marc K; Mendonca, Eneida A

2017-06-01

Clinical research involving humans is critically important, but it is a lengthy and expensive process. Most studies require institutional review board (IRB) approval. Our objective is to identify predictors of delays or accelerations in the IRB review process and apply this knowledge to inform process change in an effort to improve IRB efficiency, transparency, consistency and communication. We analyzed timelines of protocol submissions to determine protocol or IRB characteristics associated with different processing times. Our evaluation included single variable analysis to identify significant predictors of IRB processing time and machine learning methods to predict processing times through the IRB review system. Based on initial identified predictors, changes to IRB workflow and staffing procedures were instituted and we repeated our analysis. Our analysis identified several predictors of delays in the IRB review process including type of IRB review to be conducted, whether a protocol falls under Veteran's Administration purview and specific staff in charge of a protocol's review. We have identified several predictors of delays in IRB protocol review processing times using statistical and machine learning methods. Application of this knowledge to process improvement efforts in two IRBs has led to increased efficiency in protocol review. The workflow and system enhancements that are being made support our four-part goal of improving IRB efficiency, consistency, transparency, and communication.

A novel adaptive, real-time algorithm to detect gait events from wearable sensors.

PubMed

Chia Bejarano, Noelia; Ambrosini, Emilia; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Monticone, Marco; Ferrante, Simona

2015-05-01

A real-time, adaptive algorithm based on two inertial and magnetic sensors placed on the shanks was developed for gait-event detection. For each leg, the algorithm detected the Initial Contact (IC), as the minimum of the flexion/extension angle, and the End Contact (EC) and the Mid-Swing (MS), as minimum and maximum of the angular velocity, respectively. The algorithm consisted of calibration, real-time detection, and step-by-step update. Data collected from 22 healthy subjects (21 to 85 years) walking at three self-selected speeds were used to validate the algorithm against the GaitRite system. Comparable levels of accuracy and significantly lower detection delays were achieved with respect to other published methods. The algorithm robustness was tested on ten healthy subjects performing sudden speed changes and on ten stroke subjects (43 to 89 years). For healthy subjects, F1-scores of 1 and mean detection delays lower than 14 ms were obtained. For stroke subjects, F1-scores of 0.998 and 0.944 were obtained for IC and EC, respectively, with mean detection delays always below 31 ms. The algorithm accurately detected gait events in real time from a heterogeneous dataset of gait patterns and paves the way for the design of closed-loop controllers for customized gait trainings and/or assistive devices.

Real-Time Gait Event Detection Based on Kinematic Data Coupled to a Biomechanical Model.

PubMed

Lambrecht, Stefan; Harutyunyan, Anna; Tanghe, Kevin; Afschrift, Maarten; De Schutter, Joris; Jonkers, Ilse

2017-03-24

Real-time detection of multiple stance events, more specifically initial contact (IC), foot flat (FF), heel off (HO), and toe off (TO), could greatly benefit neurorobotic (NR) and neuroprosthetic (NP) control. Three real-time threshold-based algorithms have been developed, detecting the aforementioned events based on kinematic data in combination with a biomechanical model. Data from seven subjects walking at three speeds on an instrumented treadmill were used to validate the presented algorithms, accumulating to a total of 558 steps. The reference for the gait events was obtained using marker and force plate data. All algorithms had excellent precision and no false positives were observed. Timing delays of the presented algorithms were similar to current state-of-the-art algorithms for the detection of IC and TO, whereas smaller delays were achieved for the detection of FF. Our results indicate that, based on their high precision and low delays, these algorithms can be used for the control of an NR/NP, with the exception of the HO event. Kinematic data is used in most NR/NP control schemes and is thus available at no additional cost, resulting in a minimal computational burden. The presented methods can also be applied for screening pathological gait or gait analysis in general in/outside of the laboratory.

Impact of Transcranial Doppler Ultrasound on Logistics and Outcomes in Stroke Thrombolysis: Results From the SITS-ISTR.

PubMed

Mazya, Michael V; Ahmed, Niaz; Azevedo, Elsa; Davalos, Antoni; Dorado, Laura; Karlinski, Michal; Lorenzano, Svetlana; Neumann, Jiří; Toni, Danilo; Moreira, Tiago P

2018-07-01

Diagnostic transcranial Doppler ultrasound (TCD) is commonly used in patients with acute stroke before or during treatment with intravenous thrombolysis (IVT). We aimed to assess how much TCD delays IVT initiation and whether TCD influences outcomes. We analyzed data from the SITS-ISTR (Safe Implementation of Thrombolysis in Stroke-International Stroke Thrombolysis Register) collected from December 2002 to December 2011. Outcomes were door-to-needle time, symptomatic intracerebral hemorrhage, functional outcome per the modified Rankin Scale, and mortality at 3 months. In hospitals performing any TCD pre-IVT, 1701 of 11 265 patients (15%) had TCD before IVT initiation. Door-to-needle time was higher in patients with pre-IVT TCD (74 versus 60 minutes; P <0.001). At hospitals performing any TCD during IVT infusion, of 9044 patients with IVT, 747 were examined with TCD during IVT. No treatment delay was seen with TCD during IVT. After multivariate adjustment, TCD during IVT was independently associated with modestly increased excellent functional outcome (modified Rankin Scale, 0-1; adjusted odds ratio, 1.28; 95% confidence interval, 1.06-1.55; P =0.012) and lower mortality (adjusted odds ratio, 0.73; 95% confidence interval, 0.55-0.95; P =0.022). We recommend that TCD, if performed, should be done during IVT infusion, to avoid treatment delay. The association of hyperacute TCD with beneficial outcomes suggests potential impact on patient management, which warrants further study. © 2018 American Heart Association, Inc.

Cross-cultural differences in dementia: the Sociocultural Health Belief Model.

PubMed

Sayegh, Philip; Knight, Bob G

2013-04-01

Many minority ethnic (ME) older adults face several culturally associated and systemic barriers to timely dementia diagnoses that may result in delays to dementia care-seeking. We aimed to develop and propose a model illustrating variables that influence dementia care-seeking among ME older adults. We conducted a literature review on the effects of these barriers on diagnostic delays and impairment levels at initial evaluation. We also strived to provide a basis for the Sociocultural Health Belief Model (SHBM) to guide future research and service planning pertaining to culture and dementia care-seeking. There was consistent evidence that ME older adults with dementia tended to have greater diagnostic delays and higher levels of cognitive impairment and behavioral and psychological symptoms of dementia at initial evaluation than their non-Hispanic White counterparts. We also found several barriers to dementia care-seeking among ME groups. These barriers included lower levels of acculturation and accurate knowledge about dementia, more culturally associated beliefs about dementia, such as the perception of memory loss as normal aging and stigma associated with dementia, and health system barriers. The SHBM provides an empirically based conceptual framework for examining cross-cultural differences in dementia care-seeking among diverse groups. We provide recommendations for future research, such as the need for research with more diverse ethnic subgroups and the examination of group-specific cultural values. We conclude with a discussion of the clinical and service implications of our review, including potential interventions aimed at facilitating timely dementia diagnoses among ME older adults.

Wait for It: Post-supernova Winds Driven by Delayed Radioactive Decays

NASA Astrophysics Data System (ADS)

Shen, Ken J.; Schwab, Josiah

2017-01-01

In most astrophysical situations, the radioactive decay of {}56{Ni} to {}56{Co} occurs via electron capture with a fixed half-life of 6.1 days. However, this decay rate is significantly slowed when the nuclei are fully ionized because K-shell electrons are unavailable for capture. In this paper, we explore the effect of these delayed decays on white dwarfs (WDs) that may survive Type Ia and Type Iax supernovae (SNe Ia and SNe Iax). The energy released by the delayed radioactive decays of {}56{Ni} and {}56{Co} drives a persistent wind from the surviving WD’s surface that contributes to the late-time appearance of these SNe after emission from the bulk of the SN ejecta has faded. We use the stellar evolution code MESA to calculate the hydrodynamic evolution and resulting light curves of these winds. Our post-SN Ia models conflict with late-time observations of SN 2011fe, but uncertainties in our initial conditions prevent us from ruling out the existence of surviving WD donors. Much better agreement with observations is achieved with our models of post-SN Iax bound remnants, providing evidence that these explosions are due to deflagrations in accreting WDs that fail to completely unbind the WDs. Future radiative transfer calculations and wind models utilizing simulations of explosions for more accurate initial conditions will extend our study of radioactively powered winds from post-SN surviving WDs and enable their use as powerful discriminants among the various SN Ia and SN Iax progenitor scenarios.

Religiosity, spirituality, and cancer fatalism beliefs on delay in breast cancer diagnosis in African American women.

PubMed

Gullatte, Mary Magee; Brawley, Otis; Kinney, Anita; Powe, Barbara; Mooney, Kathi

2010-03-01

African American women are more likely than any other racial or ethnic group to present with a later stage of breast cancer at initial diagnosis. Delay in breast cancer detection is a critical factor in diagnosis at a later stage. Available data indicate a delay of 3 months or more is a significant factor in breast cancer mortalty. Numerous factors have been reported as contributing to delay in time to seek medical care including religiosity, spirituality, and fatalistic beliefs. This study examined the influence of religiosity, spirituality, and cancer fatalism on delay in diagnosis and breast cancer stage in African American women with self-detected breast symptoms. A descriptive correlation, retrospective methodology using an open-ended questionnaire and three validated measurement scales were used: the Religious Problem Solving Scale (RPSS), the Religious Coping Activity Scale (RCAS) subscale measuring spiritually based coping, and the modified Powe Fatalism Inventory (mPFI). A convenience sample of 129 women ages between 30 and 84 years who self-reported detecting a breast symptom before diagnosis of breast cancer within the preceding 12 months were included in the study. Outcome variables were time to seek medical care and breast cancer stage. Other variables of interest included marital status, income, education, insurance status, and to whom the women spoke about their breast symptoms. Data were analyzed using descriptive statistics, logistic regression analysis, Pearson r correlations, Mann-Whitney U analysis, and Chi Square analysis. Participants were found to be highly religious and spiritual but not fatalistic. While most women delayed more than 3 months in seeking medical care, no associations were found between the three predictor variables and time to seek medical care. The median delay in time from self detection of a breast symptom to seeking medical care was 5.5 months. Women who were less educated, unmarried, and talked to God only about their breast change were significantly more likely to delay seeking medical care. An association was found between disclosing a breast symptom to God only and delay in seeking medical care. In contrast, women who had told a person about their breast symptom were more likely to seek medical care sooner. African American women who delayed seeking medical care for longer than 3 months were more likely to present with a later stage of breast cancer than women who sought care within 3 months of symptom discovery.

The hybrid delay task: Can capuchin monkeys (Cebus apella) sustain a delay after an initial choice to do so?

PubMed Central

Paglieri, Fabio; Focaroli, Valentina; Bramlett, Jessica; Tierno, Valeria; McIntyre, Joseph M.; Addessi, Elsa; Evans, Theodore A.; Beran, Michael J.

2013-01-01

Choosing to wait for a better outcome (delay choice) and sustaining the delay prior to that outcome (delay maintenance) are both prerequisites for successful self control in intertemporal choices. However, most existing experimental methods test these skills in isolation from each other, and no significant correlation has been observed in performance across these tasks. In this study we introduce a new paradigm, the hybrid delay task, which combines an initial delay choice with a subsequent delay maintenance stage. This allows testing how often choosing to wait is paired with the actual ability to do so. We tested 18 capuchin monkeys (Cebus apella) from two laboratories in various conditions, and we found that subjects frequently chose the delayed reward but then failed to wait for it, due to poor delay maintenance. However, performance improved with experience and different behavioral responses for error correction were evident. These findings have far reaching implications: if such a high error rate was observed also in other species (possibly including Homo sapiens), this may indicate that delay choice tasks that make use of salient, prepotent stimuli do not reliably assess generalized self control, insofar as choosing to wait does not entail always being able to do so. PMID:23274585

Transfer of patients with ST-elevation myocardial infarction for primary percutaneous coronary intervention: a province-wide evaluation of "door-in to door-out" delays at the first hospital.

PubMed

Lambert, Laurie J; Brown, Kevin A; Boothroyd, Lucy J; Segal, Eli; Maire, Sébastien; Kouz, Simon; Ross, Dave; Harvey, Richard; Rinfret, Stéphane; Xiao, Yongling; Nasmith, James; Bogaty, Peter

2014-06-24

Interhospital transfer of patients with ST-elevation myocardial infarction (STEMI) for primary percutaneous coronary intervention (PPCI) is associated with longer delays to reperfusion, related in part to turnaround ("door in" to "door out," or DIDO) time at the initial hospital. As part of a systematic, province-wide evaluation of STEMI care, we examined DIDO times and associations with patient, hospital, and process-of-care factors. We performed medical chart review for STEMI patients transferred for PPCI during a 6-month period (October 1, 2008, through March 31, 2009) and linked these data to ambulance service databases. Two core laboratory cardiologists reviewed presenting ECGs to identify left bundle-branch block and, in the absence of left bundle-branch block, definite STEMI (according to both cardiologists) or an ambiguous reading. Median DIDO time was 51 minutes (25th to 75th percentile: 35-82 minutes); 14.1% of the 988 patients had a timely DIDO interval (≤30 minutes as recommended by guidelines). The data-to-decision delay was the major contributor to DIDO time. Female sex, more comorbidities, longer symptom duration, arrival by means other than ambulance, arrival at a hospital not exclusively transferring for PPCI, arrival at a center with a low STEMI volume, and an ambiguous ECG were independently associated with longer DIDO time. When turnaround was timely, 70% of patients received timely PPCI (door-to-device time ≤90 minutes) versus 14% if turnaround was not timely (P<0.0001). Benchmark DIDO times for STEMI patients transferred for PPCI were rarely achieved. Interventions aimed at facilitating the transfer decision, particularly in cases of ECGs that are difficult to interpret, are likely to have the best impact on reducing delay to reperfusion. © 2014 American Heart Association, Inc.

A Study on Health Seeking Behaviors of Patients of Post-Kala-Azar Dermal Leishmaniasis

PubMed Central

Basher, Ariful; Nath, Proggananda; Nabi, Shah Golam; Selim, Shahjada; Rahman, Md Fashiur; Sutradhar, Satya Ranjan; Faiz, Abul; Bhuiyan, Matiur Rahman; Ahmed, Be-Nazir; Rahman, Ridwanur

2015-01-01

Post-Kala-Azar Dermal Leishmaniasis (PKDL) remains a major public health threat in Bangladesh. A cross-sectional study was carried out in Surya Kanta Kala azar Research Centre (SKKRC), Mymensingh, from January 2012 to July 2013 to evaluate the health seeking behaviour and the length of delay of PKDL management. The consecutive 200 diagnosed PKDL cases that got treatment in SKKRC hospital were subjected to evaluation. Most (98%) of the patients were not aware and had no knowledge about PKDL, though 87.5% had a history of history of Kala-azar treatment. Many patients reported first to village doctor (15.5%), the pharmacy shop (10%), or traditional health provider (7.5%) upon recognition of symptom. The time between the initial symptom recognition and first medical consultation (patient delay) ranged from 10 days to 4745 days (13 years) with a median of 373 days (mean: 696; IQR: 138 to 900 days). The time between first medical consultations to definite treatment (system delay) ranged from 0 days to 1971 days (5.4 years), with a median delay of 14 days (mean: 46.48; IQR: 7 to 44 days) that was reported in this study. Age, education, occupation, and residential status had significant association with patient delay (P < 0.05). Educational status, occupation, number of treatment providers, and first health care provider had a significant association with system delay (P < 0.05). Success in PKDL diagnosis and treatment requires specific behavior from patients and health care providers which facilitate those practices. PMID:26788500

Delayed repair of distal biceps tendon ruptures is successful: a case-control study.

PubMed

Haverstock, John; Grewal, Ruby; King, Graham J W; Athwal, George S

2017-06-01

The literature has shown an increased complication rate with a delay to surgical repair of acute distal biceps tendon ruptures; however, little has been documented regarding the outcome of delayed repairs. This case-control study compared a study cohort of delayed (>21 days) distal biceps tendon repairs with a control cohort repaired acutely (<21 days). Sixteen delayed repair cases were reviewed and matched with acute controls (1:3) based on repair technique, age, and workers' compensation status. The delayed cohort was reviewed and completed isometric strength testing and the Disabilities of the Arm, Shoulder and Hand questionnaire; Patient-Rated Elbow Evaluation; and American Shoulder and Elbow Surgeons elbow questionnaire. The time to surgery averaged 37 ± 12 days in the delayed cohort versus 10 ± 6 days in the acute cohort. Complications occurred in 63% of patients in the delayed cohort versus 29% in the acute cohort (P = .04); however, 90% of the delayed cohort's complications consisted of transient paresthesias. Follow-up scores on the Patient-Rated Elbow Evaluation, Disabilities of the Arm, Shoulder and Hand questionnaire, and American Shoulder and Elbow Surgeons elbow questionnaire were not statistically different between cohorts (P > .37, P > .22, and P > .46, respectively). Despite a high rate of initial complications, patients treated with distal biceps tendon repair after a delay (>21 days) can expect similar functional outcomes to those treated acutely. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

GNSS Active Network of West of Sao Paulo State Applied to Ionosphere Monitoring

NASA Astrophysics Data System (ADS)

Aguiar, C. R.; Camargo, P. D.

2008-12-01

In Brazil, a research project of atmospheric studies from reference stations equipped with dual frequency GNSS receivers is in initial phase. These stations have composed the GNSS Active Network of West Sao Paulo State (Network-GNSS-SP) and have been broadcasting GNSS data in real time. Network-GNSS-SP is in tests phase and it's the first Brazilian network to provide GNSS measurements in real time. In Spatial Geodesy Study Brazilian Group (GEGE) has been researched the ionosphere effects on L band signal, as well as the GPS potential on ionosphere dynamic monitoring and, consequently, the application of this one to spatial geophysics study, besides dynamic ionosphere modeling. An algorithm based on Kalman filter has been developed for ionosphere modeling at low latitude regions and estimation of ionospheric parameters as absolute vertical TEC (VTEC) for the monitoring of ionosphere behavior. The approach used in this study is to apply a model for the ionospheric vertical delay. In the algorithm, the ionospheric vertical delay is modeled and expanded by Fourier series. In this paper has been realized on-line processing of the Network-GNSS-SP data and the initial results reached with the algorithm can already be analyzed. The results show the ionospheric maps created from real time TEC estimates.

Relationship between mechanical dyssynchrony and intra-operative electrical delay times in patients undergoing cardiac resynchronization therapy

PubMed Central

2014-01-01

Background It is important to understand the relationship between electrical and mechanical ventricular activation in CRT patients. By measuring local electrical activation at multiple locations within the coronary veins and myocardial contraction at the same locations in the left ventricle, we determined the relationship between electrical and mechanical activation at potential left ventricular pacing locations. Methods In this study, mechanical contraction times were computed using high temporal resolution cine cardiovascular magnetic resonance (CMR) data, while electrical activation times were derived from intra-procedural local electrograms. Results In our cohort, there was a strong correlation between electrical and mechanical delay times within each patient (R2 = 0.78 ± 0.23). Additionally, the latest electrically activated location corresponded with the latest mechanically contracting location in 91% of patients. Conclusions This study provides initial evidence that our method of obtaining non-invasive mechanical activation patterns accurately reflects the underlying electromechanical substrate of intraventricular dyssynchrony. PMID:24393383

Feedback control of flow vorticity at low Reynolds numbers.

PubMed

Zeitz, Maria; Gurevich, Pavel; Stark, Holger

2015-03-01

Our aim is to explore strategies of feedback control to design and stabilize novel dynamic flow patterns in model systems of complex fluids. To introduce the control strategies, we investigate the simple Newtonian fluid at low Reynolds number in a circular geometry. Then, the fluid vorticity satisfies a diffusion equation. We determine the mean vorticity in the sensing area and use two control strategies to feed it back into the system by controlling the angular velocity of the circular boundary. Hysteretic feedback control generates self-regulated stable oscillations in time, the frequency of which can be adjusted over several orders of magnitude by tuning the relevant feedback parameters. Time-delayed feedback control initiates unstable vorticity modes for sufficiently large feedback strength. For increasing delay time, we first observe oscillations with beats and then regular trains of narrow pulses. Close to the transition line between the resting fluid and the unstable modes, these patterns are relatively stable over long times.

Effect of long-time immersion of soft denture liners in water on viscoelastic properties.

PubMed

Iwasaki, Naohiko; Yamaki, Chisato; Takahashi, Hidekazu; Oki, Meiko; Suzuki, Tetsuya

2017-09-26

Aim of this study was to investigate the effect of long-time immersion of soft denture liners in 37°C water on viscoelastic properties. Six silicone-based and two acrylic resin-based soft denture liners were selected. Cylindrical specimens were stored in distilled water at 37°C for 6 months. Viscoelastic properties, which were instantaneous and delayed elastic displacements, viscous flow, and residual displacement, were determined using a creep meter, and analyzed with 2-way analysis of variance and Tukey's comparison (α=0.05). Viscoelastic properties and their time-dependent changes were varied among materials examined. The observed viscoelastic properties of three from six silicone-based liners did not significantly change after 6-month immersion, but those of two acrylic resin-based liners significantly changed with the increase of immersion time. However, the sum of initial instantaneous elastic displacement and delayed elastic displacement of two acrylic resin-based liners during 6-month immersion changed less than 10%, which might indicate clinically sufficient elastic performance.

Time Required for Institutional Review Board Review at One Veterans Affairs Medical Center

PubMed Central

Hall, Daniel E.; Hanusa, Barbara H.; Stone, Roslyn A.; Ling, Bruce S.; Arnold, Robert M.

2015-01-01

IMPORTANCE Despite growing concern that institutional review boards (IRBs) impose burdensome delays on research, little is known about the time required for IRB review across different types of research. OBJECTIVE To measure the overall and incremental process times for IRB review as a process of quality improvement. DESIGN, SETTING, AND PARTICIPANTS After developing a detailed process flowchart of the IRB review process, 2 analysts abstracted temporal data from the records pertaining to all 103 protocols newly submitted to the IRB at a large urban Veterans Affairs medical center from June 1, 2009, through May 31, 2011. Disagreements were reviewed with the principal investigator to reach consensus. We then compared the review times across review types using analysis of variance and post hoc Scheffé tests after achieving normally distributed data through logarithmic transformation. MAIN OUTCOMES AND MEASURES Calendar days from initial submission to final approval of research protocols. RESULTS Initial IRB review took 2 to 4 months, with expedited and exempt reviews requiring less time (median [range], 85 [23–631] and 82 [16–437] days, respectively) than full board reviews (median [range], 131 [64–296] days; P = .008). The median time required for credentialing of investigators was 1 day (range, 0–74 days), and review by the research and development committee took a median of 15 days (range, 0–184 days). There were no significant differences in credentialing or research and development times across review types (exempt, expedited, or full board). Of the extreme delays in IRB review, 80.0% were due to investigators' slow responses to requested changes. There were no systematic delays attributable to the information security officer, privacy officer, or IRB chair. CONCLUSIONS AND RELEVANCE Measuring and analyzing review times is a critical first step in establishing a culture and process of continuous quality improvement among IRBs that govern research programs. The review times observed at this IRB are substantially longer than the 60-day target recommended by expert panels. The method described here could be applied to other IRBs to begin identifying and improving inefficiencies. PMID:25494359

TIMING OF SHOCK WAVES

DOEpatents

Tuck, J.L.

1955-03-01

This patent relates to means for ascertaining the instant of arrival of a shock wave in an exploslve charge and apparatus utilizing this means to coordinate the timing of two operations involving a short lnterval of time. A pair of spaced electrodes are inserted along the line of an explosive train with a voltage applied there-across which is insufficient to cause discharge. When it is desired to initiate operation of a device at the time the explosive shock wave reaches a particular point on the explosive line, the device having an inherent time delay, the electrodes are located ahead of the point such that the ionization of the area between the electrodes caused by the traveling explosive shock wave sends a signal to initiate operation of the device to cause it to operate at the proper time. The operated device may be photographic equipment consisting of an x-ray illuminating tube.

Application of Viscoelastic Fracture Model and Non-uniform Crack Initiation at Clinically Relevant Notches in Crosslinked UHMWPE

PubMed Central

Sirimamilla, P. Abhiram; Furmanski, Jevan; Rimnac, Clare M.

2012-01-01

The mechanism of crack initiation from a clinically relevant notch is not well-understood for crosslinked ultra high molecular weight polyethylene (UHMWPE) used in total joint replacement components. Static mode driving forces, rather than the cyclic mode conditions typically associated with fatigue processes, have been shown to drive crack propagation in this material. Thus, in this study, crack initiation in a notched specimen under a static load was investigated. A video microscope was used to monitor the notch surface of the specimen and crack initiation time was measured from the video by identifying the onset of crack initiation at the notch. Crack initiation was considered using a viscoelastic fracture theory. It was found that the mechanism of crack initiation involved both single layer and a distributed multi-layer phenomenon and that multi-layer crack initiation delayed the crack initiation time for all loading conditions examined. The findings of this study support that the viscoelastic fracture theory governs fracture mechanics in crosslinked UHMWPE. The findings also support that crack initiation from a notch in UHMWPE is a more complex phenomenon than treated by traditional fracture theories for polymers. PMID:23127638

[Opportunities to improve hospital emergency care of patients with diabetic ketoacidosis].

PubMed

Navarro-Díaz, Francisco José; Amillo, Mónica; Rosales, María; Panadero, Ana; Ena, Javier

2015-02-01

To identify opportunities to improve the care of adult patients with diabetic ketoacidosis in the emergency room. Retrospective observational study of records for 2010 to 2013. Searching for International Classification of Diseases discharge codes 250.1–250.3 we identified patients who met the following 3 criteria: ketonuria of 100 mg/dL or more, diagnosed diabetes or glucose concentration of 250 mg/dL or more, and venous blood pH below 7.30 (or venous bicarbonate concentration less than 18 mEq/L). We reviewed the cases to extract patient and clinical characteristics and time from triage until diagnosis and start of treatment. The findings were compared with recommendations in clinical practice guidelines. We identified 49 episodes of diabetic ketoacidosis (4 mild, 32 moderate, and 13 severe) in 43 patients. The median delay between triage until the first blood test results were available was 142 minutes (range, 59-597 minutes). In 50% of the cases fluid therapy was delayed beyond the time recommended in clinical practice guidelines. Intravenous insulin was also delayed (in 66%) and insuficient intravenous potassium was given in 65%. Sodium bicarbonate was overused (in 50%). Half the patients developed hypokalemia in the hospital. Diagnosis and initiation of treatment were often delayed for patients with diabetic ketoacidosis in our emergency department.

Speech and language support: How physicians can identify and treat speech and language delays in the office setting.

PubMed

Moharir, Madhavi; Barnett, Noel; Taras, Jillian; Cole, Martha; Ford-Jones, E Lee; Levin, Leo

2014-01-01

Failure to recognize and intervene early in speech and language delays can lead to multifaceted and potentially severe consequences for early child development and later literacy skills. While routine evaluations of speech and language during well-child visits are recommended, there is no standardized (office) approach to facilitate this. Furthermore, extensive wait times for speech and language pathology consultation represent valuable lost time for the child and family. Using speech and language expertise, and paediatric collaboration, key content for an office-based tool was developed. early and accurate identification of speech and language delays as well as children at risk for literacy challenges; appropriate referral to speech and language services when required; and teaching and, thus, empowering parents to create rich and responsive language environments at home. Using this tool, in combination with the Canadian Paediatric Society's Read, Speak, Sing and Grow Literacy Initiative, physicians will be better positioned to offer practical strategies to caregivers to enhance children's speech and language capabilities. The tool represents a strategy to evaluate speech and language delays. It depicts age-specific linguistic/phonetic milestones and suggests interventions. The tool represents a practical interim treatment while the family is waiting for formal speech and language therapy consultation.

Correlating Transcription Initiation and Conformational Changes by a Single-Subunit RNA Polymerase with Near Base-Pair Resolution.

PubMed

Koh, Hye Ran; Roy, Rahul; Sorokina, Maria; Tang, Guo-Qing; Nandakumar, Divya; Patel, Smita S; Ha, Taekjip

2018-05-17

We provide a comprehensive analysis of transcription in real time by T7 RNA Polymerase (RNAP) using single-molecule fluorescence resonance energy transfer by monitoring the entire life history of transcription initiation, including stepwise RNA synthesis with near base-pair resolution, abortive cycling, and transition into elongation. Kinetically branching pathways were observed for abortive initiation with an RNAP either recycling on the same promoter or exchanging with another RNAP from solution. We detected fast and slow populations of RNAP in their transition into elongation, consistent with the efficient and delayed promoter release, respectively, observed in ensemble studies. Real-time monitoring of abortive cycling using three-probe analysis showed that the initiation events are stochastically branched into productive and failed transcription. The abortive products are generated primarily from initiation events that fail to progress to elongation, and a majority of the productive events transit to elongation without making abortive products. Copyright © 2018 Elsevier Inc. All rights reserved.

When the bell tolls on Bell's palsy: finding occult malignancy in acute-onset facial paralysis.

PubMed

Quesnel, Alicia M; Lindsay, Robin W; Hadlock, Tessa A

2010-01-01

This study reports 4 cases of occult parotid malignancy presenting with sudden-onset facial paralysis to demonstrate that failure to regain tone 6 months after onset distinguishes these patients from Bell's palsy patients with delayed recovery and to propose a diagnostic algorithm for this subset of patients. A case series of 4 patients with occult parotid malignancies presenting with acute-onset unilateral facial paralysis is reported. Initial imaging on all 4 patients did not demonstrate a parotid mass. Diagnostic delays ranged from 7 to 36 months from time of onset of facial paralysis to time of diagnosis of parotid malignancy. Additional physical examination findings, especially failure to regain tone, as well as properly protocolled radiologic studies reviewed with dedicated head and neck radiologists, were helpful in arriving at the diagnosis. An algorithm to minimize diagnostic delays in this subset of acute facial paralysis patients is presented. Careful attention to facial tone, in addition to movement, is important in the diagnostic evaluation of acute-onset facial paralysis. Copyright 2010 Elsevier Inc. All rights reserved.

Evaluation of quality improvement initiative in pediatric oncology: implementation of aggressive hydration protocol.

PubMed

Fratino, Lisa M; Daniel, Denise A; Cohen, Kenneth J; Chen, Allen R

2009-01-01

Our goal was to improve the efficiency of chemotherapy administration for pediatric oncology patients. We identified prechemotherapy hydration as the process that most often delayed chemotherapy administration. An aggressive hydration protocol, supported by fluid order sets, was developed for patients receiving planned chemotherapy. The mean interval from admission to achieving adequate hydration status was reduced significantly from 4.9 to 1.4 hours with a minor reduction in the time to initiate chemotherapy from 9.6 to 8.6 hours. Chemotherapy availability became the new rate-limiting process.

The Hippocampus Remains Activated over the Long Term for the Retrieval of Truly Episodic Memories

PubMed Central

Harand, Caroline; Bertran, Françoise; La Joie, Renaud; Landeau, Brigitte; Mézenge, Florence; Desgranges, Béatrice; Peigneux, Philippe; Eustache, Francis; Rauchs, Géraldine

2012-01-01

The role of the hippocampus in declarative memory consolidation is a matter of intense debate. We investigated the neural substrates of memory retrieval for recent and remote information using functional magnetic resonance imaging (fMRI). 18 young, healthy participants learned a series of pictures. Then, during two fMRI recognition sessions, 3 days and 3 months later, they had to determine whether they recognized or not each picture using the “Remember/Know” procedure. Presentation of the same learned images at both delays allowed us to track the evolution of memories and distinguish consistently episodic memories from those that were initially episodic and then became familiar or semantic over time and were retrieved without any contextual detail. Hippocampal activation decreased over time for initially episodic, later semantic memories, but remained stable for consistently episodic ones, at least in its posterior part. For both types of memories, neocortical activations were observed at both delays, notably in the ventromedial prefrontal and anterior cingulate cortices. These activations may reflect a gradual reorganization of memory traces within neural networks. Our data indicate maintenance and strengthening of hippocampal and cortico-cortical connections in the consolidation and retrieval of episodic memories over time, in line with the Multiple Trace theory (Nadel and Moscovitch, 1997). At variance, memories becoming semantic over time consolidate through strengthening of cortico-cortical connections and progressive disengagement of the hippocampus. PMID:22937055

Overcoming phase 1 delays: the critical component of obstetric fistula prevention programs in resource-poor countries

PubMed Central

2012-01-01

Background An obstetric fistula is a traumatic childbirth injury that occurs when labor is obstructed and delivery is delayed. Prolonged obstructed labor leads to the destruction of the tissues that normally separate the bladder from the vagina and creates a passageway (fistula) through which urine leaks continuously. Women with a fistula become social outcasts. Universal high-quality maternity care has eliminated the obstetric fistula in wealthy countries, but millions of women in resource-poor nations still experience prolonged labor and tens of thousands of new fistula sufferers are added to the millions of pre-existing cases each year. This article discusses fistula prevention in developing countries, focusing on the factors which delay treatment of prolonged labor. Discussion Obstetric fistulas can be prevented through contraception, avoiding obstructed labor, or improving outcomes for women who develop obstructed labor. Contraception is of little use to women who are already pregnant and there is no reliable screening test to predict obstruction in advance of labor. Improving the outcome of obstructed labor depends on prompt diagnosis and timely intervention (usually by cesarean section). Because obstetric fistulas are caused by tissue compression, the time interval from obstruction to delivery is critical. This time interval is often extended by delays in deciding to seek care, delays in arriving at a hospital, and delays in accessing treatment after arrival. Communities can reasonably demand that governments and healthcare institutions improve the second (transportation) and third (treatment) phases of delay. Initial delays in seeking hospital care are caused by failure to recognize that labor is prolonged, confusion concerning what should be done (often the result of competing therapeutic pathways), lack of women’s agency, unfamiliarity with and fear of hospitals and the treatments they offer (especially surgery), and economic constraints on access to care. Summary Women in resource-poor countries will use institutional obstetric care when the services provided are valued more than the competing choices offered by a pluralistic medical system. The key to obstetric fistula prevention is competent obstetrical care delivered respectfully, promptly, and at affordable cost. The utilization of these services is driven largely by trust. PMID:22809234

Risk Factors for Delayed Entrance into Care after Diagnosis among Patients with Late-Stage HIV Disease in Southern Vietnam

PubMed Central

Rangarajan, Suresh; Tram, Hoang Nguyen Bao; Todd, Catherine S.; Thinh, Tran; Hung, Van; Hieu, Pham Thanh; Hanh, Tran My; Chau, Khong Minh; Lam, Nguyen Danh; Hung, Pham Tri; West, Gary; Colby, Donn

2014-01-01

Background We surveyed HIV patients with late-stage disease in southern Vietnam to determine if barriers to access and service quality resulted in late HIV testing and delays from initial diagnosis to entry into HIV care. Methodology 196 adult patients at public HIV clinics with CD4 counts less than 250 cells/mm3 completed a standardized questionnaire. We used multivariate analysis to determine risk factors for delayed entry into care, defined as >3 months time from diagnosis to registration. Results Common reasons for delayed testing were feeling healthy (71%), fear of stigma and discrimination in the community (43%), time conflicts with work or school (31%), did not want to know if infected (30%), and fear of lack of confidentiality (27%). Forty-five percent of participants delayed entry into care with a median CD4 count of 65 cells/mm3. The most common reasons for delayed entry were feeling healthy (51%), fear of stigma and discrimination in the community (41%), time conflicts with work or school (33%), and fear of lack of confidentiality (26%). Independent predictors for delayed entry were feeling healthy (aOR 3.7, 95% CI 1.5–9.1), first positive HIV test at other site (aOR 2.9, CI 1.2–7.1), history of injection drug use (IDU) (aOR 2.9, 95% CI 1.1–7.9), work/school conflicts (aOR 4.3, 95% CI 1.7–10.8), prior registration at another clinic (aOR 77.4, 95% CI 8.6–697), detention or imprisonment (aOR 10.3, 95% CI 1.8–58.2), and perceived distance to clinic (aOR 3.7, 95% CI 1.0–13.7). Conclusion Delayed entry into HIV care in Vietnam is common and poses a significant challenge to preventing AIDS and opportunistic infections, decreasing mortality, and reducing HIV transmission. Improved linkages between testing and care are needed, particularly for patients who feel healthy, as well as incarcerated and drug-using populations who may face structural and social barriers to accessing care. PMID:25330196

Turnaround Time for Early Infant HIV Diagnosis in Rural Zambia: A Chart Review

PubMed Central

Sutcliffe, Catherine G.; van Dijk, Janneke H.; Hamangaba, Francis; Mayani, Felix; Moss, William J.

2014-01-01

Background Early infant HIV diagnosis is challenging in sub-Saharan Africa, particularly in rural areas where laboratory capacity is limited. Specimens must be transported to central laboratories for testing, leading to delays in diagnosis and initiation of antiretroviral therapy. This study was undertaken in rural Zambia to measure the turnaround time for confirmation of HIV infection and identify delays in diagnosis. Methods Chart reviews were conducted from 2010–2012 for children undergoing early infant HIV diagnosis at Macha Hospital in Zambia. Relevant dates, receipt of drugs by mother and child for the prevention of mother-to-child transmission (PMTCT), and test results were abstracted. Results 403 infants provided 476 samples for early infant diagnosis. The median age at the “6-week” and “6-month” assessments was 8.1 weeks and 7.0 months, respectively. The majority of mothers (80%) and infants (67%) received PMTCT. The median time between sample collection and arrival at the central laboratory in Lusaka was 17 days (IQR: 10, 28); arrival at the central laboratory to testing was 6 days (IQR: 5, 11); testing to return of results to the clinic was 29 days (IQR: 17, 36); arrival of results at the clinic to return of results to the caregiver was 45 days (IQR: 24, 79). The total median time from sample collection to return of results to the caregiver was 92 days (IQR: 84, 145). The proportion of HIV PCR positive samples was 12%. The total median turnaround time was shorter for HIV PCR positive as compared to negative or invalid samples (85 vs. 92 days; p = 0.08). Conclusions Delays in processing and communicating test results were identified, particularly in returning results from the central laboratory to the clinic and from the clinic to the caregiver. A more efficient process is needed so that caregivers can be provided test results more rapidly, potentially resulting in earlier treatment initiation and better outcomes for HIV-infected infants. PMID:24475214

Timing of the initiation of parenteral nutrition in critically ill children.

PubMed

Jimenez, Lissette; Mehta, Nilesh M; Duggan, Christopher P

2017-05-01

To review the current literature evaluating clinical outcomes of early and delayed parenteral nutrition initiation among critically ill children. Nutritional management remains an important aspect of care among the critically ill, with enteral nutrition generally preferred. However, inability to advance enteral feeds to caloric goals and contraindications to enteral nutrition often leads to reliance on parenteral nutrition. The timing of parenteral nutrition initiation is varied among critically ill children, and derives from an assessment of nutritional status, energy requirements, and physiologic differences between adults and children, including higher nutrient needs and lower body reserves. A recent randomized control study among critically ill children suggests improved clinical outcomes with avoiding initiation of parenteral nutrition on day 1 of admission to the pediatric ICU. Although there is no consensus on the optimal timing of parenteral nutrition initiation among critically ill children, recent literature does not support the immediate initiation of parenteral nutrition on pediatric ICU admission. A common theme in the reviewed literature highlights the importance of accurate assessment of nutritional status and energy expenditure in deciding when to initiate parenteral nutrition. As with all medical interventions, the initiation of parenteral nutrition should be considered in light of the known benefits of judiciously provided nutritional support with the known risks of artificial, parenteral feeding.

Timing of the initiation of parenteral nutrition in critically ill children

PubMed Central

Jimenez, Lissette; Mehta, Nilesh M.; Duggan, Christopher

2018-01-01

Purpose of Review To review the current literature evaluating clinical outcomes of early and delayed parenteral nutrition initiation among critically ill children. Recent Findings Nutritional management remains an important aspect of care among the critically ill, with enteral nutrition (EN) generally preferred. However, inability to advance enteral feeds to caloric goals and contraindications to EN often leads to reliance on parenteral nutrition (PN). The timing of PN initiation is varied among critically ill children, and derives from an assessment of nutritional status, energy requirements, and physiologic differences between adults and children, including higher nutrient needs and lower body reserves. A recent randomized control study among critically ill children suggests improved clinical outcomes with postponing initiation of PN to 1 week after admission to the pediatric intensive care unit (PICU). Summary Although there is no consensus on the optimal timing of PN initiation among critically ill children, recent literature does not support the immediate initiation of PN on PICU admission. A common theme in the reviewed literature highlights the importance of accurate assessment of nutritional status and energy expenditure in deciding when to initiate PN. As with all medical interventions, the initiation of PN should be considered in light of the known benefits of judiciously provided nutritional support with the known risks of artificial, parenteral feeding. PMID:28376054

Assessing health seeking behaviour among tuberculosis patients in rural South Africa.

PubMed

Pronyk, R M; Makhubele, M B; Hargreaves, J R; Tollman, S M; Hausler, H P

2001-07-01

South Africa's rural Northern Province. To examine patterns of health seeking behaviour among hospitalised tuberculosis patients. Information on personal characteristics, health seeking behaviour and delays to presentation and hospitalisation was collected from hospitalised TB patients. Analysis of rates was used to investigate factors associated with delay. Among 298 patients, median total delay to hospitalisation was 10 weeks, with patient delay contributing a greater proportion than service provider delay. Patients more often presented initially to public hospitals (41%) or clinics (31 %) than to spiritual/traditional healers (15%) or private GPs (13%). Total delay was shorter amongst those presenting to hospitals than those presenting to clinics (rate ratio 1.33, 95%CI 1.13-1.85), with a significantly smaller proportion of the total delay attributable to the health service provider (18% vs. 42%). Those exhibiting a conventional risk profile for TB (migrants, alcohol drinkers, history of TB) were diagnosed most quickly by health services, while women remained undiagnosed for longer. Considerable delay exists between symptom onset and treatment initiation among pulmonary tuberculosis patients. While a substantial delay was attributable to late patient presentation, an important, preventable period of infectiousness was caused by the failure of recognised clinical services to diagnose tuberculosis among symptomatic individuals.

Determination of time of death in forensic science via a 3-D whole body heat transfer model.

PubMed

Bartgis, Catherine; LeBrun, Alexander M; Ma, Ronghui; Zhu, Liang

2016-12-01

This study is focused on developing a whole body heat transfer model to accurately simulate temperature decay in a body postmortem. The initial steady state temperature field is simulated first and the calculated weighted average body temperature is used to determine the overall heat transfer coefficient at the skin surface, based on thermal equilibrium before death. The transient temperature field postmortem is then simulated using the same boundary condition and the temperature decay curves at several body locations are generated for a time frame of 24h. For practical purposes, curve fitting techniques are used to replace the simulations with a proposed exponential formula with an initial time delay. It is shown that the obtained temperature field in the human body agrees very well with that in the literature. The proposed exponential formula provides an excellent fit with an R 2 value larger than 0.998. For the brain and internal organ sites, the initial time delay varies from 1.6 to 2.9h, when the temperature at the measuring site does not change significantly from its original value. The curve-fitted time constant provides the measurement window after death to be between 8h and 31h if the brain site is used, while it increases 60-95% at the internal organ site. The time constant is larger when the body is exposed to colder air, since a person usually wears more clothing when it is cold outside to keep the body warm and comfortable. We conclude that a one-size-fits-all approach would lead to incorrect estimation of time of death and it is crucial to generate a database of cooling curves taking into consideration all the important factors such as body size and shape, environmental conditions, etc., therefore, leading to accurate determination of time of death. Copyright © 2016 Elsevier Ltd. All rights reserved.

Temporal-contextual processing in working memory: evidence from delayed cued recall and delayed free recall tests.

PubMed

Loaiza, Vanessa M; McCabe, David P

2012-02-01

Three experiments are reported that addressed the nature of processing in working memory by investigating patterns of delayed cued recall and free recall of items initially studied during complex and simple span tasks. In Experiment 1, items initially studied during a complex span task (i.e., operation span) were more likely to be recalled after a delay in response to temporal-contextual cues, relative to items from subspan and supraspan list lengths in a simple span task (i.e., word span). In Experiment 2, items initially studied during operation span were more likely to be recalled from neighboring serial positions during delayed free recall than were items studied during word span trials. Experiment 3 demonstrated that the number of attentional refreshing opportunities strongly predicts episodic memory performance, regardless of whether the information is presented in a spaced or massed format in a modified operation span task. The results indicate that the content-context bindings created during complex span trials reflect attentional refreshing opportunities that are used to maintain items in working memory.

Stoma creation: does onset of ostomy care education delay hospital length of stay?

PubMed

Rashidi, Laila; Long, Kevin; Hawkins, Melinda; Menon, Raman; Bellevue, Oliver

2016-05-01

Balancing patient safety with hospital length of stay (LOS) and associated cost is critically important. Subjectively, we have observed that patients undergoing ostomy creation early in the week have a shorter LOS. We retrospectively reviewed LOS based on day of the week the operation was performed. We reviewed 180 patients undergoing minimally invasive surgery with planned ostomy. Group 1 underwent surgery on Monday to Wednesday (n = 77), Group 2 on Thursday (n = 49), and Group 3 on Friday (n = 54). The average LOS for Group 1, 2, and 3 was 6.2, 4.9, and 7.2 days, respectively. The average number of visits with ostomy nursing for Group 1, 2, and 3 was 2.7, 1.8, and 2.3, respectively. Day of initial ostomy nursing visit was significantly correlated between the delay to initial visit and LOS with Group 3 delayed most. Patients with the longest delay to initial nurse visit had the longest LOS, with Friday operations being most delayed. A contributing factor may be absence of ostomy teaching over the weekend. Copyright © 2016 Elsevier Inc. All rights reserved.

Local Stability of AIDS Epidemic Model Through Treatment and Vertical Transmission with Time Delay

NASA Astrophysics Data System (ADS)

Novi W, Cascarilla; Lestari, Dwi

2016-02-01

This study aims to explain stability of the spread of AIDS through treatment and vertical transmission model. Human with HIV need a time to positively suffer AIDS. The existence of a time, human with HIV until positively suffer AIDS can be delayed for a time so that the model acquired is the model with time delay. The model form is a nonlinear differential equation with time delay, SIPTA (susceptible-infected-pre AIDS-treatment-AIDS). Based on SIPTA model analysis results the disease free equilibrium point and the endemic equilibrium point. The disease free equilibrium point with and without time delay are local asymptotically stable if the basic reproduction number is less than one. The endemic equilibrium point will be local asymptotically stable if the time delay is less than the critical value of delay, unstable if the time delay is more than the critical value of delay, and bifurcation occurs if the time delay is equal to the critical value of delay.

Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester

DOE PAGES

Bogin, Jr., Gregory E.; Luecke, Jon; Ratcliff, Matthew A.; ...

2016-08-21

Here, an ignition delay study investigating the reduction in low temperature heat release (LTHR) and negative temperature coefficient (NTC) region with increasing ethanol concentration in binary blends of ethanol/isooctane was conducted in the Ignition Quality Tester (IQT). The IQT is advantageous for studying multi-component fuels such as iso-octane/ethanol which are difficult to study at lower temperatures covering the NTC region in traditional systems (e.g., shock tubes, rapid compression machines, etc.). The high octane numbers and concomitant long ignition delay times of ethanol and iso-octane are ideal for study in the IQT allowing the system to reach a quasi-homogeneous mixture; allowingmore » the effect of fuel chemistry on ignition delay to be investigated with minimal impact from the fuel spray due to the relatively long ignition times. NTC behavior from iso-octane/ethanol blends was observed for the first time using an IQT. Temperature sweeps of iso-octane/ethanol volumetric blends (100/0, 90/10, 80/20, 50/50, and 0/100) were conducted from 623 to 993 K at 0.5, 1.0 and 1.5 MPa and global equivalence ratios ranging from 0.7 to 1.0. Ignition of the iso-octane/ethanol blends in the IQT was also modeled using a 0-D homogeneous batch reactor model. Significant observations include: (1) NTC behavior was observed for ethanol/ iso-octane fuel blends up to 20% ethanol. (2) Ethanol produced shorter ignition delay times than iso-octane in the high temperature region. (3) The initial increase in ethanol from 0% to 10% had a lesser impact on ignition delay than increasing ethanol from 10% to 20%. (4) The 0-D model predicts that at 0.5 and 1.0 MPa ethanol produces the shortest ignition time in the high-temperature regime, as seen experimentally.« less

Effects of iso-octane/ethanol blend ratios on the observance of negative temperature coefficient behavior within the Ignition Quality Tester

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bogin, Jr., Gregory E.; Luecke, Jon; Ratcliff, Matthew A.

Here, an ignition delay study investigating the reduction in low temperature heat release (LTHR) and negative temperature coefficient (NTC) region with increasing ethanol concentration in binary blends of ethanol/isooctane was conducted in the Ignition Quality Tester (IQT). The IQT is advantageous for studying multi-component fuels such as iso-octane/ethanol which are difficult to study at lower temperatures covering the NTC region in traditional systems (e.g., shock tubes, rapid compression machines, etc.). The high octane numbers and concomitant long ignition delay times of ethanol and iso-octane are ideal for study in the IQT allowing the system to reach a quasi-homogeneous mixture; allowingmore » the effect of fuel chemistry on ignition delay to be investigated with minimal impact from the fuel spray due to the relatively long ignition times. NTC behavior from iso-octane/ethanol blends was observed for the first time using an IQT. Temperature sweeps of iso-octane/ethanol volumetric blends (100/0, 90/10, 80/20, 50/50, and 0/100) were conducted from 623 to 993 K at 0.5, 1.0 and 1.5 MPa and global equivalence ratios ranging from 0.7 to 1.0. Ignition of the iso-octane/ethanol blends in the IQT was also modeled using a 0-D homogeneous batch reactor model. Significant observations include: (1) NTC behavior was observed for ethanol/ iso-octane fuel blends up to 20% ethanol. (2) Ethanol produced shorter ignition delay times than iso-octane in the high temperature region. (3) The initial increase in ethanol from 0% to 10% had a lesser impact on ignition delay than increasing ethanol from 10% to 20%. (4) The 0-D model predicts that at 0.5 and 1.0 MPa ethanol produces the shortest ignition time in the high-temperature regime, as seen experimentally.« less

Experimental dissociation of individual quality, food and timing of breeding effects on double-brooding in a migratory songbird.

PubMed

O'Brien, Erin L; Dawson, Russell D

2013-07-01

Annual reproductive success in many species is influenced by the number of breeding attempts within a season. Although previous studies have shown isolated effects of female quality, food, and timing of breeding on the probability of female birds producing second broods, to our knowledge, none have tested the relative importance of multiple factors and their interactions using simultaneous manipulations within populations of free-living birds. In this study, we show that individual quality and timing of breeding interact to affect the probability of double-brooding in female mountain bluebirds (Sialia currucoides). High-quality females (those that naturally initiated clutches early in the season) were more likely to double-brood, regardless of whether their hatching date was advanced or delayed, whereas later breeding, lower quality females were much less likely to double-brood when their first attempt was delayed. This indicates that annual fecundity of poorer quality (or younger) female bluebirds may be more sensitive to seasonal variation in environmental conditions. In addition, birds that were provided with supplemental food throughout first breeding attempts were more likely to double-brood in one of the study years, suggesting that female bluebirds may be energetically limited in their capacity to initiate a second brood. Females that had their first brood delayed also had a shorter inter-brood interval and were moulting fewer feathers during second broods compared to controls, while females in better condition showed more advanced moult in second breeding attempts. Taken together, our results demonstrate the combined effects of age- or individual quality-mediated energetic trade-offs between current and future reproduction, and between investments in offspring and self-maintenance, on annual fecundity of female birds.

Apparatus for simultaneously disreefing a centrally reefed clustered parachute system

DOEpatents

Johnson, Donald W.

1988-01-01

A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a central line attached between the payload and the cutter is stretched upon deployment of the cluster. A pyrotechnic or electronic time delay may be included in the cutter to delay the actual simultaneous cutting of all lines until the clustered parachutes attain a measure of stability prior to being disreefed. A second set of reefing lines and second tether lines may be provided for each parachute, to enable a two-stage, separately timed, step-by-step disreefing.

Apparatus for simultaneously disreefing a centrally reefed clustered parachute system

DOEpatents

Johnson, D.W.

1988-06-21

A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a central line attached between the payload and the cutter is stretched upon deployment of the cluster. A pyrotechnic or electronic time delay may be included in the cutter to delay the actual simultaneous cutting of all lines until the clustered parachutes attain a measure of stability prior to being disreefed. A second set of reefing lines and second tether lines may be provided for each parachute, to enable a two-stage, separately timed, step-by-step disreefing. 13 figs.

A Method for Oscillation Errors Restriction of SINS Based on Forecasted Time Series.

PubMed

Zhao, Lin; Li, Jiushun; Cheng, Jianhua; Jia, Chun; Wang, Qiufan

2015-07-17

Continuity, real-time, and accuracy are the key technical indexes of evaluating comprehensive performance of a strapdown inertial navigation system (SINS). However, Schuler, Foucault, and Earth periodic oscillation errors significantly cut down the real-time accuracy of SINS. A method for oscillation error restriction of SINS based on forecasted time series is proposed by analyzing the characteristics of periodic oscillation errors. The innovative method gains multiple sets of navigation solutions with different phase delays in virtue of the forecasted time series acquired through the measurement data of the inertial measurement unit (IMU). With the help of curve-fitting based on least square method, the forecasted time series is obtained while distinguishing and removing small angular motion interference in the process of initial alignment. Finally, the periodic oscillation errors are restricted on account of the principle of eliminating the periodic oscillation signal with a half-wave delay by mean value. Simulation and test results show that the method has good performance in restricting the Schuler, Foucault, and Earth oscillation errors of SINS.

A Method for Oscillation Errors Restriction of SINS Based on Forecasted Time Series

PubMed Central

Zhao, Lin; Li, Jiushun; Cheng, Jianhua; Jia, Chun; Wang, Qiufan

2015-01-01

Continuity, real-time, and accuracy are the key technical indexes of evaluating comprehensive performance of a strapdown inertial navigation system (SINS). However, Schuler, Foucault, and Earth periodic oscillation errors significantly cut down the real-time accuracy of SINS. A method for oscillation error restriction of SINS based on forecasted time series is proposed by analyzing the characteristics of periodic oscillation errors. The innovative method gains multiple sets of navigation solutions with different phase delays in virtue of the forecasted time series acquired through the measurement data of the inertial measurement unit (IMU). With the help of curve-fitting based on least square method, the forecasted time series is obtained while distinguishing and removing small angular motion interference in the process of initial alignment. Finally, the periodic oscillation errors are restricted on account of the principle of eliminating the periodic oscillation signal with a half-wave delay by mean value. Simulation and test results show that the method has good performance in restricting the Schuler, Foucault, and Earth oscillation errors of SINS. PMID:26193283

Dopaminergic lesions of the dorsolateral striatum in rats increase delay discounting in an impulsive choice task.

PubMed

Tedford, Stephanie E; Persons, Amanda L; Napier, T Celeste

2015-01-01

Dysregulated dopamine transmission in striatal circuitry is associated with impulsivity. The current study evaluated the influence of dopaminergic inputs to the dorsolateral striatum on impulsive choice, one aspect of impulsive behavior. We implemented an operant task that measures impulsive choice in rats via delay discounting wherein intracranial self-stimulation (ICSS) was used as the positive reinforcer. To do so, rats were anesthetized to allow implanting of a stimulating electrode within the lateral hypothalamus of one hemisphere and bilateral dorsal striatal injections of the dopaminergic toxin, 6-OHDA (lesioned) or its vehicle (sham). Following recovery, rats were trained in a delay discounting task wherein they selected between a small ICSS current presented immediately after lever pressing, and a large ICSS current presented following a 0 to 15 s delay upon pressing the alternate lever. Task acquisition and reinforcer discrimination were similar for lesioned and sham rats. All rats exhibited an initial preference for the large reinforcer, and as the delay was increased, preference for the large reinforcer was decreased indicating that the subjective value of the large reinforcer was discounted as a function of delay time. However, this discounting effect was significantly enhanced in lesioned rats for the longer delays. These data reveal a contribution of dopaminergic inputs to the dorsolateral striatum on impulsive choice behavior, and provide new insights into neural substrates underlying discounting behaviors.

Dopaminergic Lesions of the Dorsolateral Striatum in Rats Increase Delay Discounting in an Impulsive Choice Task

PubMed Central

Tedford, Stephanie E.; Persons, Amanda L.; Napier, T. Celeste

2015-01-01

Dysregulated dopamine transmission in striatal circuitry is associated with impulsivity. The current study evaluated the influence of dopaminergic inputs to the dorsolateral striatum on impulsive choice, one aspect of impulsive behavior. We implemented an operant task that measures impulsive choice in rats via delay discounting wherein intracranial self-stimulation (ICSS) was used as the positive reinforcer. To do so, rats were anesthetized to allow implanting of a stimulating electrode within the lateral hypothalamus of one hemisphere and bilateral dorsal striatal injections of the dopaminergic toxin, 6-OHDA (lesioned) or its vehicle (sham). Following recovery, rats were trained in a delay discounting task wherein they selected between a small ICSS current presented immediately after lever pressing, and a large ICSS current presented following a 0 to 15s delay upon pressing the alternate lever. Task acquisition and reinforcer discrimination were similar for lesioned and sham rats. All rats exhibited an initial preference for the large reinforcer, and as the delay was increased, preference for the large reinforcer was decreased indicating that the subjective value of the large reinforcer was discounted as a function of delay time. However, this discounting effect was significantly enhanced in lesioned rats for the longer delays. These data reveal a contribution of dopaminergic inputs to the dorsolateral striatum on impulsive choice behavior, and provide new insights into neural substrates underlying discounting behaviors. PMID:25927685

The effects of the framing of time on delay discounting.

PubMed

DeHart, William Brady; Odum, Amy L

2015-01-01

We examined the effects of the framing of time on delay discounting. Delay discounting is the process by which delayed outcomes are devalued as a function of time. Time in a titrating delay discounting task is often framed in calendar units (e.g., as 1 week, 1 month, etc.). When time is framed as a specific date, delayed outcomes are discounted less compared to the calendar format. Other forms of framing time; however, have not been explored. All participants completed a titrating calendar unit delay-discounting task for money. Participants were also assigned to one of two delay discounting tasks: time as dates (e.g., June 1st, 2015) or time in units of days (e.g., 5000 days), using the same delay distribution as the calendar delay-discounting task. Time framed as dates resulted in less discounting compared to the calendar method, whereas time framed as days resulted in greater discounting compared to the calendar method. The hyperboloid model fit best compared to the hyperbola and exponential models. How time is framed may alter how participants attend to the delays as well as how the delayed outcome is valued. Altering how time is framed may serve to improve adherence to goals with delayed outcomes. © Society for the Experimental Analysis of Behavior.

Marine stratus initiative at San Francisco International Airport

DOT National Transportation Integrated Search

1996-06-25

San Francisco International Airport is one of the busiest airports in the United States and one of the highest delay airports in terms of total aircraft delay hours and number of imposed air traffic delay programs. May through September, weather fore...

Anatomy of a late spring snowfall on sea ice

NASA Astrophysics Data System (ADS)

Perovich, Donald; Polashenski, Christopher; Arntsen, Alexandra; Stwertka, Carolyn

2017-03-01

Spring melt initiation is a critical process for Arctic sea ice. Melting conditions decrease surface albedo at a time of high insolation, triggering powerful albedo feedback. Weather events during melt initiation, such as new snowfalls, can stop or reverse the albedo decline, however. Here we present field observations of such a snow event and demonstrate its enduring impact through summer. Snow fell 3-6 June 2014 in the Chukchi Sea, halting melt onset. The snow not only raised albedo but also provided a significant negative latent heat flux, averaging -51 W m-2 from 3 to 6 June. The snowfall delayed sustained melt by 11 days, creating cascading impacts on surface energy balance that totaled some 135 MJ/m2 by mid-August. The findings highlight the sensitivity of sea ice conditions on seasonal time scales to melt initiation processes.

Potential adjustment methodology for missing data and reporting delay in the HIV Surveillance System, European Union/European Economic Area, 2015.

PubMed

Rosinska, Magdalena; Pantazis, Nikos; Janiec, Janusz; Pharris, Anastasia; Amato-Gauci, Andrew J; Quinten, Chantal; Ecdc Hiv/Aids Surveillance Network

2018-06-01

Accurate case-based surveillance data remain the key data source for estimating HIV burden and monitoring prevention efforts in Europe. We carried out a literature review and exploratory analysis of surveillance data regarding two crucial issues affecting European surveillance for HIV: missing data and reporting delay. Initial screening showed substantial variability of these data issues, both in time and across countries. In terms of missing data, the CD4+ cell count is the most problematic variable because of the high proportion of missing values. In 20 of 31 countries of the European Union/European Economic Area (EU/EEA), CD4+ counts are systematically missing for all or some years. One of the key challenges related to reporting delays is that countries undertake specific one-off actions in effort to capture previously unreported cases, and that these cases are subsequently reported with excessive delays. Slightly different underlying assumptions and effectively different models may be required for individual countries to adjust for missing data and reporting delays. However, using a similar methodology is recommended to foster harmonisation and to improve the accuracy and usability of HIV surveillance data at national and EU/EEA levels.

Density and delay of punishment of free-operant avoidance1

PubMed Central

Baron, Alan; Kaufman, Arnold; Fazzini, Dan

1969-01-01

In two experiments, the free-operant shock-avoidance behavior of rats was punished by electric shock. Two aspects of the schedule of response-produced shock were varied: the frequency of punishment over time (punishment density) and the temporal interval between the punished response and the punishment (punishment delay). The general finding was that response-produced shock suppressed avoidance responding under most of the density-delay combinations studied, and suppression increased as a function of increases in density and decreases in delay. Rate increases of small magnitude also were observed, usually as an initial reaction to the lesser densities and longer delays. Response suppression, while decreasing the number of punishment shocks received, also increased the number of avoidance shocks, so that the total number of shocks received usually was greater than the minimal number possible. The results were discussed from the standpoint of similarities between the effects of punishing positively and negatively reinforced behavior. The finding that subjects did not minimize the total number of shocks suggested that when avoidance behavior is punished, responding is controlled more by the local consequences of responding than by overall shock frequencies during the course of the session. PMID:16811408

Quantification of the impact of multifaceted initiatives intended to improve operational efficiency and the safety culture: a case study from an academic medical center radiation oncology department.

PubMed

Chera, Bhishamjit S; Mazur, Lukasz; Jackson, Marianne; Taylor, Kinely; Mosaly, Prithima; Chang, Sha; Deschesne, Kathy; LaChapelle, Dana; Hoyle, Lesley; Saponaro, Patricia; Rockwell, John; Adams, Robert; Marks, Lawrence B

2014-01-01

We have systematically been incorporating several operational efficiency and safety initiatives into our academic radiation oncology clinic. We herein quantify the impact of these initiatives on prospectively collected, clinically meaningful, metrics. The data from 5 quality improvement initiatives, each focused on a specific safety/process concern in our clinic, are presented. Data was collected prospectively: operational metrics recorded before and after implementation of the initiative were compared using statistical analysis. Results from the Agency for Health Care Research and Quality (AHRQ) patient safety culture surveys administered during and after many of these initiatives were similarly compared. (1) Workload levels for nurses assisting with brachytherapy were high (National Aeronautics and Space Administration Task Load Index (NASA-TLX) scores >55-60, suggesting, "overwork"). Changes in work flow and procedure room layout reduced workload to more acceptable levels (NASA-TLX <55; P < .01). (2) The rate of treatment therapists being interrupted was reduced from a mean of 4 (range, 1-11) times per patient treatment to a mean <1 (range, 0-3; P < .001) after implementing standards for electronic communication and placement of monitors informing patients and staff of the treatment machine status (ie, delayed, on time). (3) The rates of replans by dosimetrists was reduced from 11% to 6% (P < .01) through a more systematic pretreatment peer review process. (4) Standardizing nursing and resident functions reduced patient wait times by ≈ 45% (14 min; P < .01). (5) Standardizing presimulation instructions from the physician reduced the number of patients experiencing delays on the simulator (>50% to <10%; P < .01). To assess the overall changes in "patient safety culture," we conducted a pre- and postanalysis using the AHRQ survey. Improvements in all measured dimensions were noted. Quality improvement initiatives can be successfully implemented in an academic radiation oncology department to yield measurable improvements in operations resulting in improvement in patient safety culture. Copyright © 2014 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

The usefulness of diffusion-weighted magnetic resonance imaging performed in the acute phase as an early predictor of delayed neuropsychiatric sequelae in acute carbon monoxide poisoning.

PubMed

Kim, Y S; Cha, Y S; Kim, M S; Kim, H J; Lee, Y S; Youk, H; Kim, H I; Kim, O H; Cha, K-C; Kim, H; Lee, K H; Hwang, S O

2018-06-01

Delayed onset of neuropsychiatric symptoms after apparent recovery from acute carbon monoxide (CO) poisoning has been described as delayed neuropsychiatric sequelae (DNS). No previous study has determined whether early use of diffusion-weighted magnetic resonance imaging (DWI) can predict which patients will develop DNS in the acute CO poisoning. This retrospective observational study was performed on adult patients with acute CO poisoning consecutively treated over a 17-month period. All included patients with acute CO poisoning underwent DWI to evaluate brain injury within 72 h after CO exposure. DWI was evaluated as follows: (1) presence of pathology, (2) number of pathologies, (3) asymmetry, and (4) location of pathology. Patients were divided into two groups. The DNS group was composed of patients with delayed sequelae, while the non-DNS group included patients with no sequelae. A total of 102 patients with acute CO poisoning were finally enrolled in this study. DNS developed in 10 patients (9.8%). Between the DNS group and the non-DNS group, presence of pathology on DWI and initial Glasgow Coma Scale (GCS) showed significant difference. There was also a statistical difference between the non-DNS group and DNS group in terms of CO exposure time, troponin I, rhabdomyolysis, acute kidney injury, and pneumonia. The presence of pathology in DWI and initial GCS (cutoff: <12) at the emergency department served as an early predictors of DNS.

Helicopter Fatigue Design Guide

DTIC Science & Technology

1983-11-01

for example, glass and carbon fibre reinforced plastics. The general principles behind the substantiation procedures for these materials are...initiating cause of many minor (and sometimes major) cracks that can lead to expensive repair, even though they may not immediately cause a safety...be seen, blade stresses correlated well with both unsteady models. However, push rod loads calculated with the Time Delay Model are much less than

The duration of hypotension before the initiation of antibiotic treatment is a critical determinant of survival in a murine model of Escherichia coli septic shock: association with serum lactate and inflammatory cytokine levels.

PubMed

Kumar, Anand; Haery, Cameron; Paladugu, Bhanu; Kumar, Aseem; Symeoneides, Simon; Taiberg, Leo; Osman, Jailan; Trenholme, Gordon; Opal, Steven M; Goldfarb, Roy; Parrillo, Joseph E

2006-01-15

This study was designed to examine the relationship between the timing of antibiotic treatment and both survival rates and hemodynamic/inflammatory correlates of survival in a murine model of Escherichia coli septic shock. Surgical implantation of an E. coli (O18:K1:H7)-laced, gelatin capsule-encased fibrinogen clot was used to generate a bacteremic model of murine septic shock. Survival duration, hemodynamic responses, and circulating serum tumor necrosis factor (TNF)-alpha , interleukin (IL)-6, and lactate levels were assessed in relation to increasing delays in or absence of antibiotic treatment. A critical inflection point with respect to survival occurred between 12 and 15 h after implantation. When initiated at or before 12 h, antibiotic treatment resulted in < or = 20% mortality, but, when initiated at or after 15 h, it resulted in >85% mortality. Physiologically relevant hypotension developed in untreated septic mice by 12 h after implantation. Values for heart rate differed between untreated septic mice and sham-infected control mice by 6 h after implantation, whereas values for cardiac output and stroke volume did not differ until at least 18-24 h after implantation. Antibiotic treatment initiated > or = 12 h after implantation was associated with persistence of increased circulating serum lactate, TNF- alpha , and IL-6 levels. The timing of antibiotic treatment relative to hypotension is closely associated with survival in this murine model of septic shock. Delay in antibiotic treatment results in the persistence of inflammatory/stress markers even after antibiotic treatment is initiated.

Dynamic properties of chasers in a moving queue based on a delayed chasing model

NASA Astrophysics Data System (ADS)

Ning, Guo; Jian-Xun, Ding; Xiang, Ling; Qin, Shi; Reinhart, Kühne

2016-05-01

A delayed chasing model is proposed to simulate the chase behavior in the queue, where each member regards the closest one ahead as the target, and the leader is attracted to a target point with slight fluctuation. When the initial distances between neighbors possess an identical low value, the fluctuating target of the leader can cause an amplified disturbance in the queue. After a long period of time, the queue recovers the stable state from the disturbance, forming a straight-line-like pattern again, but distances between neighbors grow. Whether the queue can keep stable or not depends on initial distance, desired velocity, and relaxation time. Furthermore, we carry out convergence analysis to explain the divergence transformation behavior and confirm the convergence conditions, which is in approximate agreement with simulations. Project supported by the National Natural Science Foundation of China (Grant Nos. 71071044, 71001001, 71201041, and 11247291), the Doctoral Program of the Ministry of Education of China (Grant Nos. 20110111120023 and 20120111120022), the Postdoctoral Fund Project of China (Grant No. 2013M530295), the National Basic Research Program of China (Grant No. 2012CB725404), and 1000 Plan for Foreign Talent, China (Grant No. WQ20123400070).

Managing acute cholecystitis among Medicaid insured in New York State: opportunities to optimize care.

PubMed

Stey, Anne M; Greenstein, Alexander J; Aufses, Arthur; Moskowitz, Alan J; Egorova, Natalia N

2018-05-01

Identifying sources of unnecessary cost within Medicaid will help focus cost containment efforts. This study sought to identify differences in surgical management and associated costs of cholecystitis between Medicaid and privately insured in New York State. The New York State all-payer mandatory discharge database from 2003 to 2013, had 297,635 patients with Medicaid (75,512) and privately (222,123) insurance who underwent cholecystectomy for cholecystitis. Patients were stratified by insurance. Four surgical management approaches were delineated based on cholecystectomy timing: primary, interval, emergency, and delayed cholecystectomy. Delayed cholecystectomy was defined as more than one hospital visit from diagnosis to definitive cholecystectomy. Medicaid and privately insured patients were propensity score matched. Surgical management approach and associated costs were compared between matched cohorts. A greater proportion of Medicaid patients underwent delayed cholecystectomy compared to matched privately insured patients, 8.5 versus 4.8%; P < 0.001. Primary initial cholecystectomy was performed in fewer Medicaid compared to privately insured patients, 55.4 versus 66.0%, P < 0.001. Primary initial cholecystectomy was the cheapest surgical management approach, with the median cost of $3707, and delayed cholecystectomy was the most expensive, $12,212, P < 0.001. The median cost per Medicaid patient was $6170 versus $4804 per matched privately insured patient, P < 0.001. The annual predicted cost savings for New York State Medicaid would be $13,097,371, if the distribution of surgical management approaches were proportionally similar to private insurance. Medicaid patients with cholecystitis were more frequently managed with delayed cholecystectomy than privately insured patients, which had substantial cost implications for the New York Medicaid Program.

Short term memory may be the depletion of the readily releasable pool of presynaptic neurotransmitter vesicles of a metastable long term memory trace pattern.

PubMed

Tarnow, Eugen

2009-09-01

The Tagging/Retagging model of short term memory was introduced earlier (Tarnow in Cogn Neurodyn 2(4):347-353, 2008) to explain the linear relationship between response time and correct response probability for word recall and recognition: At the initial stimulus presentation the words displayed tag the corresponding long term memory locations. The tagging process is linear in time and takes about one second to reach a tagging level of 100%. After stimulus presentation the tagging level decays logarithmically with time to 50% after 14 s and to 20% after 220 s. If a probe word is reintroduced the tagging level has to return to 100% for the word to be properly identified, which leads to a delay in response time. This delay is proportional to the tagging loss. The tagging level is directly related to the probability of correct word recall and recognition. Evidence presented suggests that the tagging level is the level of depletion of the Readily Releasable Pool (RRP) of neurotransmitter vesicles at presynaptic terminals. The evidence includes the initial linear relationship between tagging level and time as well as the subsequent logarithmic decay of the tagging level. The activation of a short term memory may thus be the depletion of RRP (exocytosis) and short term memory decay may be the ensuing recycling of the neurotransmitter vesicles (endocytosis). The pattern of depleted presynaptic terminals corresponds to the long term memory trace.

Dread and the disvalue of future pain.

PubMed

Story, Giles W; Vlaev, Ivaylo; Seymour, Ben; Winston, Joel S; Darzi, Ara; Dolan, Raymond J

2013-01-01

Standard theories of decision-making involving delayed outcomes predict that people should defer a punishment, whilst advancing a reward. In some cases, such as pain, people seem to prefer to expedite punishment, implying that its anticipation carries a cost, often conceptualized as 'dread'. Despite empirical support for the existence of dread, whether and how it depends on prospective delay is unknown. Furthermore, it is unclear whether dread represents a stable component of value, or is modulated by biases such as framing effects. Here, we examine choices made between different numbers of painful shocks to be delivered faithfully at different time points up to 15 minutes in the future, as well as choices between hypothetical painful dental appointments at time points of up to approximately eight months in the future, to test alternative models for how future pain is disvalued. We show that future pain initially becomes increasingly aversive with increasing delay, but does so at a decreasing rate. This is consistent with a value model in which moment-by-moment dread increases up to the time of expected pain, such that dread becomes equivalent to the discounted expectation of pain. For a minority of individuals pain has maximum negative value at intermediate delay, suggesting that the dread function may itself be prospectively discounted in time. Framing an outcome as relief reduces the overall preference to expedite pain, which can be parameterized by reducing the rate of the dread-discounting function. Our data support an account of disvaluation for primary punishments such as pain, which differs fundamentally from existing models applied to financial punishments, in which dread exerts a powerful but time-dependent influence over choice.

Guided self-help for the treatment of pediatric obesity.

PubMed

Boutelle, Kerri N; Norman, Gregory J; Rock, Cheryl L; Rhee, Kyung E; Crow, Scott J

2013-05-01

Clinic-based programs for childhood obesity are not available to a large proportion of the population. The purpose of this study was to evaluate the efficacy of a guided self-help treatment of pediatric obesity (GSH-PO) compared with a delayed treatment control and to evaluate the impact of GSH-PO 6-months posttreatment. Fifty overweight or obese 8- to 12-year-old children and their parents were randomly assigned to immediate treatment or to delayed treatment. The GSH-PO includes 12 visits over 5 months and addresses key components included in more intensive clinic-based programs. Children and parents in the immediate treatment arm were assessed at time 1 (T1), participated in GSH-PO between T1 and T2, and completed their 6-month posttreatment assessment at T3. Children and parents in the delayed treatment arm were assessed at T1, participated in GSH-PO between T2 and T3, and completed their 6-month posttreatment assessment at T4. The main outcome measures were BMI, BMI z score, and percentage overweight (%OW). Children in the immediate treatment GSH-PO arm decreased their BMI significantly more than did the delayed treatment arm (BMI group × time = -1.39; P < .001). Similar results were found for BMI z score and %OW. At the 6-month posttreatment assessment, changes resulting from GSH-PO were maintained for BMI z score and %OW but not BMI (BMI time effect = -0.06, not significant; BMI z score time effect = -0.10, P < .001; %OW time effect = -4.86, P < .05). The GSH-PO showed initial efficacy in decreasing BMI for children in this study. Additional efficacy and translational studies are needed to additionally evaluate GSH-PO.

Dread and the Disvalue of Future Pain

PubMed Central

Story, Giles W.; Vlaev, Ivaylo; Seymour, Ben; Winston, Joel S.; Darzi, Ara; Dolan, Raymond J.

2013-01-01

Standard theories of decision-making involving delayed outcomes predict that people should defer a punishment, whilst advancing a reward. In some cases, such as pain, people seem to prefer to expedite punishment, implying that its anticipation carries a cost, often conceptualized as ‘dread’. Despite empirical support for the existence of dread, whether and how it depends on prospective delay is unknown. Furthermore, it is unclear whether dread represents a stable component of value, or is modulated by biases such as framing effects. Here, we examine choices made between different numbers of painful shocks to be delivered faithfully at different time points up to 15 minutes in the future, as well as choices between hypothetical painful dental appointments at time points of up to approximately eight months in the future, to test alternative models for how future pain is disvalued. We show that future pain initially becomes increasingly aversive with increasing delay, but does so at a decreasing rate. This is consistent with a value model in which moment-by-moment dread increases up to the time of expected pain, such that dread becomes equivalent to the discounted expectation of pain. For a minority of individuals pain has maximum negative value at intermediate delay, suggesting that the dread function may itself be prospectively discounted in time. Framing an outcome as relief reduces the overall preference to expedite pain, which can be parameterized by reducing the rate of the dread-discounting function. Our data support an account of disvaluation for primary punishments such as pain, which differs fundamentally from existing models applied to financial punishments, in which dread exerts a powerful but time-dependent influence over choice. PMID:24277999

Dynamics of scroll waves with time-delay propagation in excitable media

NASA Astrophysics Data System (ADS)

Chen, Jiang-Xing; Xiao, Jie; Qiao, Li-Yan; Xu, Jiang-Rong

2018-06-01

Information transmission delay can be widely observed in various systems. Here, we study the dynamics of scroll waves with time-delay propagation among slices in excitable media. Weak time delay induces scroll waves to meander. Through increasing the time delay, we find a series of dynamical transitions. Firstly, the straight filament of a scroll wave becomes twisted. Then, the scroll wave breaks and forms interesting patterns. With long time delay, loosed scroll waves are maintained while their period are greatly decreased. Also, cylinder waves appears. The influences of diffusively coupling strength on the time-delay-induced scroll waves are studied. It is found that the critical time delay characterizing those transitions decreases as the coupling strength is increased. A phase diagram in the diffusive coupling-time delay plane is presented.

Delayed treatment with hypothermia protects against the no-reflow phenomenon despite failure to reduce infarct size.

PubMed

Hale, Sharon L; Herring, Michael J; Kloner, Robert A

2013-01-04

Many studies have shown that when hypothermia is started after coronary artery reperfusion (CAR), it is ineffective at reducing necrosis. However, some suggest that hypothermia may preferentially reduce no-reflow. Our aim was to test the effects of hypothermia on no-reflow when initiated close to reperfusion and 30 minutes after reperfusion, times not associated with a protective effect on myocardial infarct size. Rabbits received 30 minutes coronary artery occlusion/3 hours CAR. In protocol 1, hearts were treated for 1 hour with topical hypothermia (myocardial temperature ≈32°C) initiated at 5 minutes before or 5 minutes after CAR, and the results were compared with a normothermic group. In protocol 2, hypothermia was delayed until 30 minutes after CAR and control hearts remained normothermic. In protocol 1, risk zones were similar and infarct size was not significantly reduced by hypothermia initiated close to CAR. However, the no-reflow defect was significantly reduced by 43% (5 minutes before CAR) and 38% (5 minutes after CAR) in hypothermic compared with normothermic hearts (P=0.004, ANOVA, P=ns between the 2 treated groups). In protocol 2, risk zones and infarct sizes were similar, but delayed hypothermia significantly reduced no-reflow in hypothermic hearts by 30% (55±6% of the necrotic region in hypothermia group versus 79±6% with normothermia, P=0.008). These studies suggest that treatment with hypothermia reduces no-reflow even when initiated too late to reduce infarct size and that the microvasculature is especially receptive to the protective properties of hypothermia and confirm that microvascular damage is in large part a form of true reperfusion injury.

49 CFR 236.563 - Delay time.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

49 CFR 236.563 - Delay time.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

Fertility preservation with ovarian stimulation and time to treatment in women with stage II-III breast cancer receiving neoadjuvant therapy.

PubMed

Chien, A Jo; Chambers, Julia; Mcauley, Fiona; Kaplan, Tessa; Letourneau, Joseph; Hwang, Jimmy; Kim, Mi-Ok; Melisko, Michelle E; Rugo, Hope S; Esserman, Laura J; Rosen, Mitchell P

2017-08-01

To determine whether fertility preservation with ovarian stimulation (OS) results in treatment delay in breast cancer (BC) patients receiving neoadjuvant therapy (NAT). This is a retrospective study of women screened for the prospective neoadjuvant ISPY2 trial at the University of California San Francisco. All patients were <43, had stage II-III BC, and received neoadjuvant therapy. Time to initiation of NAT was compared between women who underwent OS (STIM) and women who did not (control). Patient and tumor characteristics, as well as oncologic outcomes, were compared between STIM and control groups. 82 patients were included (34 STIM and 48 control). STIM patients were overall younger (mean = 35 vs. 36.9 years old, p = 0.06), and more likely to be childless (79.4 vs 31.2%, p < 0.0001) than controls. Mean time from diagnosis to initiation of NAT was 40 days, with no significant difference between STIM and control groups (mean 39.8 days vs 40.9 days, p = 0.75). Mean time from diagnosis to fertility consultation was 16.3 days. With median follow-up of 79 months, 16 (19.5%) patients have recurred or died from BC. Rates of pCR, recurrence, and death were similar in both groups. Six of 34 STIM patients have undergone embryo transfer, resulting in one patient with two live births. Fertility preservation with OS can be performed in the neoadjuvant setting without delay in initiation of systemic therapy and should be discussed with all early-stage BC patients of reproductive age.

Utility of repeat testing of critical values: a Q-probes analysis of 86 clinical laboratories.

PubMed

Lehman, Christopher M; Howanitz, Peter J; Souers, Rhona; Karcher, Donald S

2014-06-01

A common laboratory practice is to repeat critical values before reporting the test results to the clinical care provider. This may be an unnecessary step that delays the reporting of critical test results without adding value to the accuracy of the test result. To determine the proportions of repeated chemistry and hematology critical values that differ significantly from the original value as defined by the participating laboratory, to determine the threshold differences defined by the laboratory as clinically significant, and to determine the additional time required to analyze the repeat test. Participants prospectively reviewed critical test results for 4 laboratory tests: glucose, potassium, white blood cell count, and platelet count. Participants reported the following information: initial and repeated test result; time initial and repeat results were first known to laboratory staff; critical result notification time; if the repeat result was still a critical result; if the repeat result was significantly different from the initial result, as judged by the laboratory professional or policy; significant difference threshold, as defined by the laboratory; the make and model of the instrument used for primary and repeat testing. Routine, repeat analysis of critical values is a common practice. Most laboratories did not formally define a significant difference between repeat results. Repeated results were rarely considered significantly different. Median repeated times were at least 17 to 21 minutes for 10% of laboratories. Twenty percent of laboratories reported at least 1 incident in the last calendar year of delayed result reporting that clinicians indicated had adversely affected patient care. Routine repeat analysis of automated chemistry and hematology critical values is unlikely to be clinically useful and may adversely affect patient care.

Automatic toilet seat lowering apparatus

DOEpatents

Guerty, Harold G.

1994-09-06

A toilet seat lowering apparatus includes a housing defining an internal cavity for receiving water from the water supply line to the toilet holding tank. A descent delay assembly of the apparatus can include a stationary dam member and a rotating dam member for dividing the internal cavity into an inlet chamber and an outlet chamber and controlling the intake and evacuation of water in a delayed fashion. A descent initiator is activated when the internal cavity is filled with pressurized water and automatically begins the lowering of the toilet seat from its upright position, which lowering is also controlled by the descent delay assembly. In an alternative embodiment, the descent initiator and the descent delay assembly can be combined in a piston linked to the rotating dam member and provided with a water channel for creating a resisting pressure to the advancing piston and thereby slowing the associated descent of the toilet seat. A toilet seat lowering apparatus includes a housing defining an internal cavity for receiving water from the water supply line to the toilet holding tank. A descent delay assembly of the apparatus can include a stationary dam member and a rotating dam member for dividing the internal cavity into an inlet chamber and an outlet chamber and controlling the intake and evacuation of water in a delayed fashion. A descent initiator is activated when the internal cavity is filled with pressurized water and automatically begins the lowering of the toilet seat from its upright position, which lowering is also controlled by the descent delay assembly. In an alternative embodiment, the descent initiator and the descent delay assembly can be combined in a piston linked to the rotating dam member and provided with a water channel for creating a resisting pressure to the advancing piston and thereby slowing the associated descent of the toilet seat.

Changes in the timing of sexual initiation among young Muslim and Christian women in Nigeria.

PubMed

Agha, Sohail

2009-12-01

Sexual initiation during adolescence has important demographic and health consequences for a population, yet no systematic analysis of changes in the timing of sexual initiation has been conducted in Nigeria. Two rounds of national surveys conducted in 1990 and 2003 were used to examine changes in the timing of sexual initiation among female adolescents in Nigeria. Multivariate survival analysis using Cox proportional hazards models was used to assess changes in the risk of sexual initiation and to identify the correlates of first sex. Contrary to what has been reported in several Nigerian studies, there was no decline in age at first sex among Christian adolescents. Age at first sex did not change significantly for Christian adolescents, although premarital sex appears to have increased-primarily due to an increase in the age at marriage. Age at first sex did increase among Muslim women. Premarital sex remained low among Muslim women. A number of socioeconomic variables were associated with the timing of sexual initiation. Weekly exposure to the mass media was associated with earlier sexual initiation. The degree to which an environment was liberal or restrictive was a key determinant of the timing of sexual initiation in Nigeria. The findings also illustrate the important role of socioeconomic factors in determining the timing of sexual initiation in Nigeria. As secondary education increases in Northern Nigeria, additional increases in the age at sexual debut are likely among Muslim women. The study raises concerns about the influence of the mass media on the timing of first sex in Nigeria. The evidence of an absence of changes in the timing of sexual initiation among Christian women in more than a decade implies that programs which aim to delay the timing of sexual initiation in Southern Nigeria may have limited success. With age at marriage already high among Christian women, programs that focus on abstinence until marriage may also be pursuing an approach with limited chances of success.

Comparison of Prolonged Atrial Electromechanical Delays with Different Definitions in the Discrimination of Patients with Non-Valvular Paroxysmal Atrial Fibrillation

PubMed Central

Lee, Dong Hyun; Choi, Sun Young; Seo, Jeong-Min; Choi, Jae-Hyuk; Cho, Young-Rak; Park, Kyungil; Kim, Moo Hyun; Kim, Young-Dae

2015-01-01

Background and Objectives Previous studies have evaluated atrial electromechanical delays (AEMDs) with a number of different definitions to discriminate patients with paroxysmal atrial fibrillation (PAF) from controls without PAF. However, their discriminative values for PAF have not previously been directly compared. Subjects and Methods A total of 65 PAF patients and 130 control subjects matched for age, sex, history of hypertension, and diabetes mellitus were selected. The AEMDi and AEMDp were defined as the time intervals from the initiation of the P wave on the surface electrocardiogram to the initiation and peak of the late diastolic transmitral inflow on pulsed wave Doppler images, respectively. The AEMDim and AEMDpm were defined as the time intervals from the initiation of the P wave on the surface electrocardiogram to the initiation and peak of the late diastolic lateral mitral annular motion on tissue Doppler images, respectively. Results There were no significant differences in the clinical characteristics between the two groups. All 4 AEMDs were consistently longer in the PAF group, and proven effective to differentiate the PAF patients from the controls. The AEMDi measurement had a larger area under the curve (AUC) than the other AEMDs, left atrial volume index, and P wave amplitude. However, the AEMDp, AEMDim, and AEMDpm measurements had AUCs similar to those of the left atrial volume index and P wave amplitude. Conclusion The findings suggest that the AEMDi is better than the other AEMDs for the discrimination of PAF patients from the controls. PMID:26617650

Implications of Dynamic Pressure Transducer Mounting Variations on Measurements in Pyrotechnic Test Apparatus

NASA Technical Reports Server (NTRS)

Dibbern, Andreas; Crisafulli, Jeffrey; Hagopia, Michael; McDougle, Stephen H.; Saulsberry, Regor L.

2009-01-01

Accurate dynamic pressure measurements are often difficult to make within small pyrotechnic devices, and transducer mounting difficulties can cause data anomalies that lead to erroneous conclusions. Delayed initial pressure response followed by data ringing has been observed when using miniaturized pressure transducer mounting adapters required to interface transducers to small test chambers. This delayed pressure response and ringing, combined with a high data acquisition rate, has complicated data analysis. This paper compares the output signal characteristics from different pressure transducer mounting options, where the passage distance from the transducer face to the pyrotechnic chamber is varied in length and diameter. By analyzing the data and understating the associated system dynamics, a more realistic understanding of the actual dynamic pressure variations is achieved. Three pressure transducer mounting configurations (elongated, standard, and face/flush mount) were simultaneously tested using NASA standard initiators in closed volume pressure bombs. This paper also presents results of these pressure transducer mounting configurations as a result of a larger NASA Engineering and Safety Center pyrovalve test project. Results from these tests indicate the improved performance of using face/flush mounted pressure transducers in this application. This type of mounting improved initial pressure measurement response time by approximately 19 s over standard adapter mounting, eliminating most of the lag time; provided a near step-function type initial pressure increase; and greatly reduced data ringing in high data acquisition rate systems. The paper goes on to discuss other issues associated with the firing and instrumentation that are important for the tester to understand.

Delayed flap approach procedures for noise abatement and fuel conservation

NASA Technical Reports Server (NTRS)

Edwards, F. G.; Bull, J. S.; Foster, J. D.; Hegarty, D. M.; Drinkwater, F. J., III

1976-01-01

The NASA/Ames Research Center is currently investigating the delayed flap approach during which pilot actions are determined and prescribed by an onboard digital computer. The onboard digital computer determines the proper timing for the deployment of the landing gear and flaps based on the existing winds and airplane gross weight. Advisory commands are displayed to the pilot. The approach is flown along the conventional ILS glide slope but is initiated at a higher airspeed and in a clean aircraft configuration that allows for low thrust and results in reduced noise and fuel consumption. Topics discussed include operational procedures, pilot acceptability of these procedures, and fuel/noise benefits resulting from flight tests and simulation.

Evaluating Cloud Initialization in a Convection-permit NWP Model

NASA Astrophysics Data System (ADS)

Li, Jia; Chen, Baode

2015-04-01

In general, to avoid "double counting precipitation" problem, in convection permit NWP models, it was a common practice to turn off convective parameterization. However, if there were not any cloud information in the initial conditions, the occurrence of precipitation could be delayed due to spin-up of cloud field or microphysical variables. In this study, we utilized the complex cloud analysis package from the Advanced Regional Prediction System (ARPS) to adjust the initial states of the model on water substance, such as cloud water, cloud ice, rain water, et al., that is, to initialize the microphysical variables (i.e., hydrometers), mainly based on radar reflectivity observations. Using the Advanced Research WRF (ARW) model, numerical experiments with/without cloud initialization and convective parameterization were carried out at grey-zone resolutions (i.e. 1, 3, and 9 km). The results from the experiments without convective parameterization indicate that model ignition with radar reflectivity can significantly reduce spin-up time and accurately simulate precipitation at the initial time. In addition, it helps to improve location and intensity of predicted precipitation. With grey-zone resolutions (i.e. 1, 3, and 9 km), using the cumulus convective parameterization scheme (without radar data) cannot produce realistic precipitation at the early time. The issues related to microphysical parametrization associated with cloud initialization were also discussed.

Syringe Pump Performance Maintained with IV Filter Use During Low Flow Rate Delivery for Pediatric Patients.

PubMed

Chau, Destiny F; Vasilopoulos, Terrie; Schoepf, Miriam; Zhang, Christina; Fahy, Brenda G

2016-09-01

Complex surgical and critically ill pediatric patients rely on syringe infusion pumps for precise delivery of IV medications. Low flow rates and in-line IV filter use may affect drug delivery. To determine the effects of an in-line filter to remove air and/or contaminants on syringe pump performance at low flow rates, we compared the measured rates with the programmed flow rates with and without in-line IV filters. Standardized IV infusion assemblies with and without IV filters (filter and control groups) attached to a 10-mL syringe were primed and then loaded onto a syringe pump and connected to a 16-gauge, 16-cm single-lumen catheter. The catheter was suspended in a normal saline fluid column to simulate the back pressure from central venous circulation. The delivered infusate was measured by gravimetric methods at predetermined time intervals, and flow rate was calculated. Experimental trials for initial programmed rates of 1.0, 0.8, 0.6, and 0.4 mL/h were performed in control and filter groups. For each trial, the flow rate was changed to double the initial flow rate and was then returned to the initial flow rate to analyze pump performance for titration of rates often required during medication administration. These conditions (initial rate, doubling of initial rate, and return to initial rate) were analyzed separately for steady-state flow rate and time to steady state, whereas their average was used for percent deviation analysis. Differences between control and filter groups were assessed using Student t tests with adjustment for multiplicity (using n = 3 replications per group). Mean time from 0 to initial flow (startup delay) was <1 minute in both groups with no statistical difference between groups (P = 1.0). The average time to reach steady-state flow after infusion startup or rate changes was not statistically different between the groups (range, 0.8-5.5 minutes), for any flow rate or part of the trial (initial rate, doubling of initial rate, and return to initial rate), although the study was underpowered to detect small time differences. Overall, the mean steady-state flow rate for each trial was below the programmed flow rate with negative mean percent deviations for each trial. In the 1.0-mL/h initial rate trial, the steady-state flow rate attained was lower in the filter than the control group for the initial rate (P = 0.04) and doubling of initial rate (P = 0.04) with a trend during the return to initial rate (P = 0.06), although this same effect was not observed when doubling the initial rate trials of 0.8 or 0.6 mL/h or any other rate trials compared with the control group. With low flow rates used in complex surgical and pediatric critically ill patients, the addition of IV filters did not confer statistically significant changes in startup delay, flow variability, or time to reach steady-state flow of medications administered by syringe infusion pumps. The overall flow rate was lower than programmed flow rate with or without a filter.

Method for autologous single skin cell isolation for regenerative cell spray transplantation with non-cultured cells.

PubMed

Gerlach, Jörg C; Johnen, Christa; Ottomann, Christian; Ottoman, Christian; Bräutigam, Kirsten; Plettig, Jörn; Belfekroun, Claudia; Münch, Sandra; Hartmann, Bernd

2011-03-01

There is a therapeutic gap for patients with deep partial thickness wounds (Grade IIb) of moderate size that were initially not treated with split- or mesh grafting to avoid overgrafting, but developed delayed wound healing around two weeks after injury--at which time grafting is typically not indicated anymore. Delayed wound healing is often associated with esthetically unsatisfactory results and sometimes functional problems. An innovative cell isolation method for cell spray transplantation at the point of care, which eliminates cell culture prior to treatment, was implemented for this population of burn patients in our center. Autologous skin cell spray transplantation was initiated by taking healthy skin. The dermal/epidermal layers were separated using enzymatic digestion with 40 min dispase application, followed by 15 min trypsin application for basal kerationcyte isolation, 7 min cell washing by centrifugation, followed by transferring the cells for spraying into Ringer lactate solution. The procedure was performed on site in a single session immediately following the biopsy. After sharp wound debridement, cells were immediately transplanted by deposition with a cell sprayer for even distribution of the cell suspension. Eight patients were treated (mean age 30.3 years, mean burn total body surface area 14%, mean Abbreviated Burn Severity Index (5 points). The mean time to complete re-epithelialization was 12.6 days. All patients exhibited wound healing with improved esthetic and functional quality. Our initial experience for the use of non-cultured cells using a two-enzyme approach with cell washing suggests shortened time for wound closure, suggesting that the method may potentially avoid longer-term complications.

The HEMP QSO Monitoring Project

NASA Astrophysics Data System (ADS)

Welsh, William F.; Robinson, E. L.

2000-02-01

Many AGN are highly variable sources. Some of these show a pronounced time delay between variations seen in their optical continuum and in their emission lines. ``Echo mapping'' is a technique that uses these time delays to measure the geometry and kinematics of the gas inside the AGN, near the supermassive black hole. The technique is immensely powerful, but the results so far have been modest due to relatively low quality data. We have initiated a long--term project to echo map QSOs. We will examine nearby (but intrinsically faint) QSOs as well as QSOs at high redshift. The high--z QSOs present a problem: it is not known ahead of time which of these are variable sources. Thus we have started a campaign to monitor about 60 high-redshift QSOs for the purpose of determining their variability characteristics. We request SSTO time on the 0.9m telescope for long--term monitoring of high--redshift QSOs to: (i) test their suitability as viable echo mapping candidates; and (ii) measure (for the first time) their variability properties, which is of intrinsic value itself.

Metal-Ferroelectric-Semiconductor Field-Effect Transistor NAND Gate Switching Time Analysis

NASA Technical Reports Server (NTRS)

Phillips, Thomas A.; Macleod, Todd C.; Ho, Fat D.

2006-01-01

Previous research investigated the modeling of a N Wga te constructed of Metal-Ferroelectric- Semiconductor Field-Effect Transistors (MFSFETs) to obtain voltage transfer curves. The NAND gate was modeled using n-channel MFSFETs with positive polarization for the standard CMOS n-channel transistors and n-channel MFSFETs with negative polarization for the standard CMOS p-channel transistors. This paper investigates the MFSFET NAND gate switching time propagation delay, which is one of the other important parameters required to characterize the performance of a logic gate. Initially, the switching time of an inverter circuit was analyzed. The low-to-high and high-to-low propagation time delays were calculated. During the low-to-high transition, the negatively polarized transistor pulls up the output voltage, and during the high-to-low transition, the positively polarized transistor pulls down the output voltage. The MFSFETs were simulated by using a previously developed model which utilized a partitioned ferroelectric layer. Then the switching time of a 2-input NAND gate was analyzed similarly to the inverter gate. Extension of this technique to more complicated logic gates using MFSFETs will be studied.

Wigner time delay in photodetachment of Tm-and in photoionization of Yb: A comparative study

NASA Astrophysics Data System (ADS)

Saha, Soumyajit; Jose, Jobin; Deshmukh, Pranawa; Dolmatov, Valeriy; Kheifets, Anatoli; Manson, Steven

2017-04-01

Preliminary studies of Wigner time delay in photodetachment spectra of negative ions have been reported. Photodetachment time delay for some dipole channels of Tm- and of Cl- were calculated using relativistic random phase approximation (RRPA). Comparisons between photodetachment time delay of Cl- and photoionization time delay of Ar were made. We investigate the photodetachment time delay for all three relativistically split nd -> ɛ f channels of Tm- and for nd -> ɛ f channels of Yb (isoelectronic to Tm-) using RRPA. We study the effect of the shape resonance, brought about by the centrifugal barrier potential, on photodetachment time delay. A negative ion is a good laboratory for studying the effects of shape resonances on time delay since the phase is unaffected by the Coulomb component. Wigner time delay in photodetachment of Tm- and in photoionization of Yb: A comparative study.

Efficacy of melatonin with behavioural sleep-wake scheduling for delayed sleep-wake phase disorder: A double-blind, randomised clinical trial.

PubMed

Sletten, Tracey L; Magee, Michelle; Murray, Jade M; Gordon, Christopher J; Lovato, Nicole; Kennaway, David J; Gwini, Stella M; Bartlett, Delwyn J; Lockley, Steven W; Lack, Leon C; Grunstein, Ronald R; Rajaratnam, Shantha M W

2018-06-01

Delayed Sleep-Wake Phase Disorder (DSWPD) is characterised by sleep initiation insomnia when attempting sleep at conventional times and difficulty waking at the required time for daytime commitments. Although there are published therapeutic guidelines for the administration of melatonin for DSWPD, to our knowledge, randomised controlled trials are lacking. This trial tested the efficacy of 0.5 mg melatonin, combined with behavioural sleep-wake scheduling, for improving sleep initiation in clinically diagnosed DSWPD patients with a delayed endogenous melatonin rhythm relative to patient-desired (or -required) bedtime (DBT). This randomised, placebo-controlled, double-blind clinical trial was conducted in an Australian outpatient DSWPD population. Following 1-wk baseline, clinically diagnosed DSWPD patients with delayed melatonin rhythm relative to DBT (salivary dim light melatonin onset [DLMO] after or within 30 min before DBT) were randomised to 4-wk treatment with 0.5 mg fast-release melatonin or placebo 1 h before DBT for at least 5 consecutive nights per week. All patients received behavioural sleep-wake scheduling, consisting of bedtime scheduled at DBT. The primary outcome was actigraphic sleep onset time. Secondary outcomes were sleep efficiency in the first third of time in bed (SE T1) on treatment nights, subjective sleep-related daytime impairment (Patient Reported Outcomes Measurement Information System [PROMIS]), PROMIS sleep disturbance, measures of daytime sleepiness, clinician-rated change in illness severity, and DLMO time. Between September 13, 2012 and September 1, 2014, 307 participants were registered; 116 were randomised to treatment (intention-to-treat n = 116; n = 62 males; mean age, 29.0 y). Relative to baseline and compared to placebo, sleep onset occurred 34 min earlier (95% confidence interval [CI] -60 to -8) in the melatonin group. SE T1 increased; PROMIS sleep-related impairment, PROMIS sleep disturbance, insomnia severity, and functional disability decreased; and a greater proportion of patients showed more than minimal clinician-rated improvement following melatonin treatment (52.8%) compared to placebo (24.0%) (P < 0.05). The groups did not differ in the number of nights treatment was taken per protocol. Post-treatment DLMO assessed in a subset of patients (n = 43) was not significantly different between groups. Adverse events included light-headedness, daytime sleepiness, and decreased libido, although rates were similar between treatment groups. The clinical benefits or safety of melatonin with long-term treatment were not assessed, and it remains unknown whether the same treatment regime would benefit patients experiencing DSWPD sleep symptomology without a delay in the endogenous melatonin rhythm. In this study, melatonin treatment 1 h prior to DBT combined with behavioural sleep-wake scheduling was efficacious for improving objective and subjective measures of sleep disturbances and sleep-related impairments in DSWPD patients with delayed circadian phase relative to DBT. Improvements were achieved largely through the sleep-promoting effects of melatonin, combined with behavioural sleep-wake scheduling. This trial was registered with the Australian New Zealand Clinical Trials Registry, ACTRN12612000425897.

Effects of added polyacrylamide on changes in water states during the composting of kitchen waste.

PubMed

Yang, Yu-Qiang; Chen, Zhuo-Xian; Zhang, Xue-Qing; Hu, Li-Fang; Shen, Dong-Sheng; Long, Yu-Yang

2015-02-01

The effects of adding polyacrylamide (PAM), to attempt to delay the loss of capillary water and achieve a better level of organic matter humification, in the composting of kitchen waste were evaluated. Four treatments, with initial moisture content of 60 % were used: 0.1 % PAM added before the start of composting (R1), 0.1 % PAM added when the thermophilic phase of composting became stable (at >50 °C) (R2), 0.1 % PAM added when the moisture content significantly decreased (R3), and no PAM added (R4). The introduction of PAM in R1 and R2 significantly increased the capillary force and delayed the loss of moisture content and capillary water. The introduction of PAM in R2 and R3 improved the composting process, in terms of the degradation of biochemical fractions and the humification degree. These results show that the optimal time for adding PAM was the initial stage of the thermophilic phase.

Expression patterns of wnt8 orthologs in two sand dollar species with different developmental modes.

PubMed

Nakata, Hidewo; Minokawa, Takuya

2009-03-01

Two wnt8 orthologs, Smwnt8 and Pjwnt8, were isolated from an indirect developing sand dollar, Scaphechinus mirabilis, and a direct developing sand dollar, Peronella japonica, respectively. The expression patterns of two genes during early development were examined by whole mount in situ hybridization. The expression of Smwnt8 was initiated in the micromeres at the late 16-cell stage and expanded at the 64-cell stage to the whole vegetal hemisphere, including the presumptive endomesodermal regions. The timing of the initiation of Pjwnt8 transcription in the presumptive endomesoderm region was delayed by 2-3 cell cycles compared to that of Smwnt8. The delay, or molecular heterochrony, of Pjwnt8 transcription strongly suggests the existence of a substantial evolutionary change in the early endomesodermal specification of P. japonica. In addition to the endomesodermal expression during early embryogenesis, bilateral expressions were observed commonly in the ectoderm of two sand dollar species during larval stages.

Accelerated forgetting? An evaluation on the use of long-term forgetting rates in patients with memory problems

PubMed Central

Geurts, Sofie; van der Werf, Sieberen P.; Kessels, Roy P. C.

2015-01-01

The main focus of this review was to evaluate whether long-term forgetting rates (delayed tests, days, to weeks, after initial learning) are more sensitive measures than standard delayed recall measures to detect memory problems in various patient groups. It has been suggested that accelerated forgetting might be characteristic for epilepsy patients, but little research has been performed in other populations. Here, we identified eleven studies in a wide range of brain injured patient groups, whose long-term forgetting patterns were compared to those of healthy controls. Signs of accelerated forgetting were found in three studies. The results of eight studies showed normal forgetting over time for the patient groups. However, most of the studies used only a recognition procedure, after optimizing initial learning. Based on these results, we recommend the use of a combined recall and recognition procedure to examine accelerated forgetting and we discuss the relevance of standard and optimized learning procedures in clinical practice. PMID:26106343

Ignition delays, heats of combustion, and reaction rates of aluminum alkyl derivatives used as ignition and combustion enhancers for supersonic combustors

NASA Technical Reports Server (NTRS)

Ryan, T. W., III; Harlowe, W. W.; Schwab, S.

1992-01-01

The work was based on adapting an apparatus and procedure developed at Southwest Research Institute for rating the ignition quality of fuels for diesel engines. Aluminum alkyls and various Lewis-base adducts of these materials, both neat and mixed 50/50 with pure JP-10 hydrocarbon, were injected into the combustion bomb using a high-pressure injection system. The bomb was pre-charged with air that was set at various initial temperatures and pressures for constant oxygen density. The ignition delay times were determined for the test materials at these different initial conditions. The data are presented in absolute terms as well as comparisons with the parent alkyls. The relative heats of reaction of the various test materials were estimated based on a computation of the heat release, using the pressure data recorded during combustion in the bomb. In addition, the global reaction rates for each material were compared at a selected tmperature and pressure.

Delayed treatment of ruptured brain AVMs: is it ok to wait?

PubMed

Beecher, Jeffrey S; Lyon, Kristopher; Ban, Vin Shen; Vance, Awais; McDougall, Cameron M; Whitworth, Louis A; White, Jonathan A; Samson, Duke; Batjer, H Hunt; Welch, Babu G

2018-04-01

OBJECTIVE Despite a hemorrhagic presentation, many patients with arteriovenous malformations (AVMs) do not require emergency resection. The timing of definitive management is not standardized in the cerebrovascular community. This study was designed to evaluate the safety of delaying AVM treatment in clinically stable patients with a new hemorrhagic presentation. The authors examined the rate of rehemorrhage or neurological decline in a cohort of patients with ruptured brain AVMs during a period of time posthemorrhage. METHODS Patients presenting to the authors' institution from January 2000 to December 2015 with ruptured brain AVMs treated at least 4 weeks posthemorrhage were included in this analysis. Exclusion criteria were ruptured AVMs that required emergency surgery involving resection of the AVM, prior treatment of AVM at another institution, or treatment of lesions within 4 weeks for other reasons (subacute surgery). The primary outcome measure was time from initial hemorrhage to treatment failure (defined as rehemorrhage or neurological decline as a direct result of the AVM). Patient-days were calculated from the day of initial rupture until the day AVM treatment was initiated or treatment failed. RESULTS Of 102 ruptured AVMs in 102 patients meeting inclusion criteria, 7 (6.9%) failed the treatment paradigm. Six patients (5.8%) had a new hemorrhage within a median of 248 days (interquartile range 33-1364 days). The total "at risk" period was 18,740 patient-days, yielding a rehemorrhage rate of 11.5% per patient-year, or 0.96% per patient-month. Twelve (11.8%) of 102 patients were found to have an associated aneurysm. In this group there was a single (8.3%) new hemorrhage during a total at-risk period of 263 patient-days until the aneurysm was secured, yielding a rehemorrhage risk of 11.4% per patient-month. CONCLUSIONS It is the authors' practice to rehabilitate patients after brain AVM rupture with a plan for elective treatment of the AVM. The present data are useful in that the findings quantify the risk of the authors' treatment strategy. These findings indicate that delaying intervention for at least 4 weeks after the initial hemorrhage subjects the patient to a low (< 1%) risk of rehemorrhage. The authors modified the treatment paradigm when a high-risk feature, such as an associated intracranial aneurysm, was identified.

Effects of partial time delays on phase synchronization in Watts-Strogatz small-world neuronal networks.

PubMed

Sun, Xiaojuan; Perc, Matjaž; Kurths, Jürgen

2017-05-01

In this paper, we study effects of partial time delays on phase synchronization in Watts-Strogatz small-world neuronal networks. Our focus is on the impact of two parameters, namely the time delay τ and the probability of partial time delay p delay , whereby the latter determines the probability with which a connection between two neurons is delayed. Our research reveals that partial time delays significantly affect phase synchronization in this system. In particular, partial time delays can either enhance or decrease phase synchronization and induce synchronization transitions with changes in the mean firing rate of neurons, as well as induce switching between synchronized neurons with period-1 firing to synchronized neurons with period-2 firing. Moreover, in comparison to a neuronal network where all connections are delayed, we show that small partial time delay probabilities have especially different influences on phase synchronization of neuronal networks.

Predictive Models of Duration of Ground Delay Programs in New York Area Airports

NASA Technical Reports Server (NTRS)

Kulkarni, Deepak

2011-01-01

Initially planned GDP duration often turns out to be an underestimate or an overestimate of the actual GDP duration. This, in turn, results in avoidable airborne or ground delays in the system. Therefore, better models of actual duration have the potential of reducing delays in the system. The overall objective of this study is to develop such models based on logs of GDPs. In a previous report, we described descriptive models of Ground Delay Programs. These models were defined in terms of initial planned duration and in terms of categorical variables. These descriptive models are good at characterizing the historical errors in planned GDP durations. This paper focuses on developing predictive models of GDP duration. Traffic Management Initiatives (TMI) are logged by Air Traffic Control facilities with The National Traffic Management Log (NTML) which is a single system for automated recoding, coordination, and distribution of relevant information about TMIs throughout the National Airspace System. (Brickman, 2004 Yuditsky, 2007) We use 2008-2009 GDP data from the NTML database for the study reported in this paper. NTML information about a GDP includes the initial specification, possibly one or more revisions, and the cancellation. In the next section, we describe general characteristics of Ground Delay Programs. In the third section, we develop models of actual duration. In the fourth section, we compare predictive performance of these models. The final section is a conclusion.

Longitudinal and reciprocal relations between delay discounting and crime

PubMed Central

Lee, Christine A.; Derefinko, Karen J.; Milich, Richard; Lynam, Donald R.; DeWall, C. Nathan

2017-01-01

Theorists argue that self-control failure is the underlying cause of criminal behavior, with previous research linking poor self-control to delinquency and drug use. The path from self-control to crime is well-established, but less is known about whether criminal behavior contributes to self-control deficits over time. We investigated bi-directional relations between self-control assessed via a delay discounting task and self-reported crime over a three-year period. During their first, second (73.38% retention rate), and third (63.12% retention rate) years of college, 526 undergraduates completed a delay discounting task and reported on their criminal behavior. In order to maximize variability, participants with conduct problems were overrecruited, comprising 23.1% of the final sample. As expected, more discounting of hypothetical monetary rewards significantly predicted future property crime across a one and two-year period, even when controlling for initial levels of both. This study also demonstrated evidence of a bi-directional relationship; violent crime predicted higher rates of delay discounting one year later. These results suggest that bi-directional relations exist between self-control and types of crime. PMID:28970645

Delayed Triplet-State Formation through Hybrid Charge Transfer Exciton at Copper Phthalocyanine/GaAs Heterojunction.

PubMed

Lim, Heeseon; Kwon, Hyuksang; Kim, Sang Kyu; Kim, Jeong Won

2017-10-05

Light absorption in organic molecules on an inorganic substrate and subsequent electron transfer to the substrate create so-called hybrid charge transfer exciton (HCTE). The relaxation process of the HCTE states largely determines charge separation efficiency or optoelectronic device performance. Here, the study on energy and time-dispersive behavior of photoelectrons at the hybrid interface of copper phthalocyanine (CuPc)/p-GaAs(001) upon light excitation of GaAs reveals a clear pathway for HCTE relaxation and delayed triplet-state formation. According to the ground-state energy level alignment at the interface, CuPc/p-GaAs(001) shows initially fast hole injection from GaAs to CuPc. Thus, the electrons in GaAs and holes in CuPc form an unusual HCTE state manifold. Subsequent electron transfer from GaAs to CuPc generates the formation of the triplet state in CuPc with a few picoseconds delay. Such two-step charge transfer causes delayed triplet-state formation without singlet excitation and subsequent intersystem crossing within the CuPc molecules.

Coherent control of strong-field two-pulse ionization of Rydberg atoms.

PubMed

Fedorov, M; Poluektov, N

2000-02-28

Strong-field ionization of Rydberg atoms is investigated in its dependence on phase features of the initial coherent population of Rydberg levels. In the case of a resonance between Rydberg levels and some lower-energy atomic level (V-type transitions), this dependence is shown to be very strong: by a proper choice of the initial population an atom can be made either completely or very little ionized by a strong laser pulse. It is shown that phase features of the initial coherent population of Rydberg levels and the ionization yield can be efficiently controlled in a scheme of ionization by two strong laser pulses with a varying delay time between them.

[Risk of arrhythmia and domestic low-voltage electrical injury].

PubMed

Claudet, I; Maréchal, C; Debuisson, C; Salanne, S

2010-04-01

Analysis of domestic low-voltage (220-240 V) electrical injury in children admitted to a pediatric emergency department to illustrate the low risk of initial or delayed risk of arrhythmia. Retrospective study between 2001 and 2008 analyzing all children aged less than 15 years admitted for a low-voltage electrical injury. The data collected were age, sex, time and circumstances of the accident, time and day of admission, transport modalities, presence of risk factors for arrhythmia (transthoracic current, wet skin, tetany, loss of consciousness or neurological symptoms, and initial EKG abnormalities), injuries, EKG, muscular and/or cardiac enzyme values, progression and complications. For statistical analysis, data were entered in Microsoft Excel tables. Analysis was done with StatView5.1 (SAS Institute) and Epi Info 6.04fr (VF, ENSP epiconcept). In the descriptive analysis, the data are presented as mean values with SD, median and range. Forty-eight children were included. The mean annual number of admissions was equal to 6 (range, 3-12). The mean age was 6.2 + or - 4.3 years (median, 4.6 years). There was a male predominance: the overall sex ratio was 1.5, i.e., 3 before the age of 2 and 2.6 before the age of 10. The electrical injury occurred after contact with a wire or a connected cord or after the introduction of a metallic object in a wall socket. Ten children had risk factors of arrhythmia (mainly wet skin or thoracic pain). Twenty-nine children suffered from burns to the extremities (digits and hands, 70 %). At admission, 45 children had an EKG performed. The initial EKG was considered abnormal in 8 cases showing: sinusal tachycardia (n=4), incomplete right bundle branch block (n=4), and V(1) negative T waves (n=1). The EKG normalized within the first 12h. Hospitalization for cardiac monitoring was required for 18 children. No delayed arrhythmia occurred. In a mean time of 3.5h after the accident, a troponin dosage was given to 15 children and was normal in all cases. One child developed rhabdomyolysis and evolved without needing dialysis. After a low-voltage electrical injury, initial arrhythmia is not frequent, with often a nonspecific and transitory EKG expression; delayed arrhythmia is very rare. Children presenting to the emergency department after such an electrical accident, who are asymptomatic, without any risk factors for arrhythmia (wet skin, tetany, vertical pathway of the current, preexistent cardiological conditions, loss of consciousness) and with a normal initial EKG do not require cardiac monitoring. Copyright 2010 Elsevier Masson SAS. All rights reserved.

Delay-range-dependent chaos synchronization approach under varying time-lags and delayed nonlinear coupling.

PubMed

Zaheer, Muhammad Hamad; Rehan, Muhammad; Mustafa, Ghulam; Ashraf, Muhammad

2014-11-01

This paper proposes a novel state feedback delay-range-dependent control approach for chaos synchronization in coupled nonlinear time-delay systems. The coupling between two systems is esteemed to be nonlinear subject to time-lags. Time-varying nature of both the intrinsic and the coupling delays is incorporated to broad scope of the present study for a better-quality synchronization controller synthesis. Lyapunov-Krasovskii (LK) functional is employed to derive delay-range-dependent conditions that can be solved by means of the conventional linear matrix inequality (LMI)-tools. The resultant control approach for chaos synchronization of the master-slave time-delay systems considers non-zero lower bound of the intrinsic as well as the coupling time-delays. Further, the delay-dependent synchronization condition has been established as a special case of the proposed LK functional treatment. Furthermore, a delay-range-dependent condition, independent of the delay-rate, has been provided to address the situation when upper bound of the delay-derivative is unknown. A robust state feedback control methodology is formulated for synchronization of the time-delay chaotic networks against the L2 norm bounded perturbations by minimizing the L2 gain from the disturbance to the synchronization error. Numerical simulation results are provided for the time-delay chaotic networks to show effectiveness of the proposed delay-range-dependent chaos synchronization methodologies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Effect of delayed diagnosis on disease course and management of Churg-Strauss syndrome: a retrospective study.

PubMed

Sokołowska, Barbara; Szczeklik, Wojciech; Mastalerz, Lucyna; Kuczia, Paweł; Wodkowski, Michał; Stodółkiewicz, Edyta; Macioł, Karolina; Musiał, Jacek

2013-03-01

Delayed diagnosis in patients with Churg-Strauss syndrome (CSS) is largely attributed to the variable and nonspecific presentation of the disease's initial symptoms. The aim of the study was to evaluate the effect of delayed diagnosis on the course of CSS. We conducted a retrospective study of 30 CSS patients followed up in our department. In each patient, we assessed the delay in CSS diagnosis (the time when patients already fulfilled four out of six of the American College of Rheumatology criteria and the diagnosis was not yet established), the disease activity at the time of diagnosis, and organ involvement during CSS course. A median value of 2 weeks was chosen as the cutoff point after which the diagnosis was considered as delayed. Sixteen patients were diagnosed before (group 1) and 14 patients after this cutoff point (group 2). In group 2, we found a higher Birmingham Vasculitis Activity Score at the moment of diagnosis (20.4 vs 25.1, p < 0.05) and a more severe disease course, resulting in more frequent hospitalization rates (0.64 vs 2.26/year, p < 0.00001), higher corticosteroids dose requirements (5.87 vs 11.57 mg/day converted to methylprednisolone, p < 0.0001), and additional immunosuppressive therapy administration (56.2 vs 92.8 %, p < 0.05) to maintain disease remission. All six perinuclear pattern of antineutrophil cytoplasmic antibobodies (pANCA)-positive patients (20 %) were found in group 1. Concluding, the delay in diagnosis of CSS of more than 2 weeks was found to be associated with a disease course that was more severe. The presence of the pANCA antibodies may occasionally facilitate establishment of the diagnosis.

Parenting Predictors of Delay Inhibition in Socioeconomically Disadvantaged Preschoolers

PubMed Central

Merz, Emily C.; Landry, Susan H.; Zucker, Tricia A.; Barnes, Marcia A.; Assel, Michael; Taylor, Heather B.; Lonigan, Christopher J.; Phillips, Beth M.; Clancy-Menchetti, Jeanine; Eisenberg, Nancy; Spinrad, Tracy L.; Valiente, Carlos; de Villiers, Jill; Consortium, the School Readiness Research

2016-01-01

This study examined longitudinal associations between specific parenting factors and delay inhibition in socioeconomically disadvantaged preschoolers. At Time 1, parents and 2- to 4-year-old children (mean age = 3.21 years; N = 247) participated in a videotaped parent-child free play session, and children completed delay inhibition tasks (gift delay-wrap, gift delay-bow, and snack delay tasks). Three months later, at Time 2, children completed the same set of tasks. Parental responsiveness was coded from the parent-child free play sessions, and parental directive language was coded from transcripts of a subset of 127 of these sessions. Structural equation modeling was used, and covariates included age, gender, language skills, parental education, and Time 1 delay inhibition. Results indicated that in separate models, Time 1 parental directive language was significantly negatively associated with Time 2 delay inhibition, and Time 1 parental responsiveness was significantly positively associated with Time 2 delay inhibition. When these parenting factors were entered simultaneously, Time 1 parental directive language significantly predicted Time 2 delay inhibition whereas Time 1 parental responsiveness was no longer significant. Findings suggest that parental language that modulates the amount of autonomy allotted the child may be an important predictor of early delay inhibition skills. PMID:27833461

Complementary and alternative medicine (CAM) use and delays in presentation and diagnosis of breast cancer patients in public hospitals in Malaysia.

PubMed

Mohd Mujar, Noor Mastura; Dahlui, Maznah; Emran, Nor Aina; Abdul Hadi, Imisairi; Wai, Yan Yang; Arulanantham, Sarojah; Hooi, Chea Chan; Mohd Taib, Nur Aishah

2017-01-01

Complementary and alternative medicine (CAM) is widely used among the breast cancer patients in Malaysia. Delays in presentation, diagnosis and treatment have been shown to impact the disease prognosis. There is considerable use of CAM amongst breast cancer patients. CAM use has been cited as a cause of delay in diagnosis and treatments in qualitative studies, however there had not been any confirmatory study that confirms its impact on delays. The purpose of this study was to evaluate whether the use of CAM among newly diagnosed breast cancer patients was associated with delays in presentation, diagnosis or treatment of breast cancer. This multi-centre cross-sectional study evaluating the time points of the individual breast cancer patients' journey from first visit, resolution of diagnosis and treatments was conducted in six public hospitals in Malaysia. All newly diagnosed breast cancer patients from 1st January to 31st December 2012 were recruited. Data were collected through medical records review and patient interview by using a structured questionnaire. Complementary and alternative medicine (CAM) was defined as the use of any methods and products not included in conventional allopathic medicine before commencement of treatments. Presentation delay was defined as time taken from symptom discovery to first presentation of more than 3 months. The time points were categorised to diagnosis delay was defined as time taken from first presentation to diagnosis of more than 1 month and treatment delay was defined as time taken from diagnosis to initial treatment of more than 1 month. Multiple logistic regression was used for analysis. A total number of 340 patients participated in this study. The prevalence of CAM use was 46.5% (n = 158). Malay ethnicity (OR 3.32; 95% CI: 1.85, 5.97) and not interpreting symptom as cancerous (OR 1.79; 95% CI: 1.10, 2.92) were significantly associated with CAM use. The use of CAM was associated with delays in presentation (OR 1.65; 95% CI: 1.05, 2.59), diagnosis (OR 2.42; 95% CI: 1.56, 3.77) and treatment of breast cancer (OR 1.74; 95% CI: 1.11, 2.72) on univariate analyses. However, after adjusting with other covariates, CAM use was associated with delays in presentation (OR 1.71; 95% CI: 1.05, 2.78) and diagnosis (OR 2.58; 95% CI: 1.59, 4.17) but not for treatment of breast cancer (OR 1.58; 95% CI: 0.98, 2.55). The prevalence of CAM use among the breast cancer patients was high. Women of Malay ethnicity and not interpreting symptom as cancerous were significantly associated with CAM use. The use of CAM is significantly associated with delay in presentation and resolution of diagnosis. This study suggests further evaluation of access to breast cancer care is needed as poor access may cause the use of CAM. However, since public hospitals in Malaysia are heavily subsidized and readily available to the population, CAM use may impact delays in presentation and diagnosis.

Complementary and alternative medicine (CAM) use and delays in presentation and diagnosis of breast cancer patients in public hospitals in Malaysia

PubMed Central

Emran, Nor Aina; Abdul Hadi, Imisairi; Wai, Yan Yang; Arulanantham, Sarojah; Hooi, Chea Chan

2017-01-01

Complementary and alternative medicine (CAM) is widely used among the breast cancer patients in Malaysia. Delays in presentation, diagnosis and treatment have been shown to impact the disease prognosis. There is considerable use of CAM amongst breast cancer patients. CAM use has been cited as a cause of delay in diagnosis and treatments in qualitative studies, however there had not been any confirmatory study that confirms its impact on delays. The purpose of this study was to evaluate whether the use of CAM among newly diagnosed breast cancer patients was associated with delays in presentation, diagnosis or treatment of breast cancer. This multi-centre cross-sectional study evaluating the time points of the individual breast cancer patients’ journey from first visit, resolution of diagnosis and treatments was conducted in six public hospitals in Malaysia. All newly diagnosed breast cancer patients from 1st January to 31st December 2012 were recruited. Data were collected through medical records review and patient interview by using a structured questionnaire. Complementary and alternative medicine (CAM) was defined as the use of any methods and products not included in conventional allopathic medicine before commencement of treatments. Presentation delay was defined as time taken from symptom discovery to first presentation of more than 3 months. The time points were categorised to diagnosis delay was defined as time taken from first presentation to diagnosis of more than 1 month and treatment delay was defined as time taken from diagnosis to initial treatment of more than 1 month. Multiple logistic regression was used for analysis. A total number of 340 patients participated in this study. The prevalence of CAM use was 46.5% (n = 158). Malay ethnicity (OR 3.32; 95% CI: 1.85, 5.97) and not interpreting symptom as cancerous (OR 1.79; 95% CI: 1.10, 2.92) were significantly associated with CAM use. The use of CAM was associated with delays in presentation (OR 1.65; 95% CI: 1.05, 2.59), diagnosis (OR 2.42; 95% CI: 1.56, 3.77) and treatment of breast cancer (OR 1.74; 95% CI: 1.11, 2.72) on univariate analyses. However, after adjusting with other covariates, CAM use was associated with delays in presentation (OR 1.71; 95% CI: 1.05, 2.78) and diagnosis (OR 2.58; 95% CI: 1.59, 4.17) but not for treatment of breast cancer (OR 1.58; 95% CI: 0.98, 2.55). The prevalence of CAM use among the breast cancer patients was high. Women of Malay ethnicity and not interpreting symptom as cancerous were significantly associated with CAM use. The use of CAM is significantly associated with delay in presentation and resolution of diagnosis. This study suggests further evaluation of access to breast cancer care is needed as poor access may cause the use of CAM. However, since public hospitals in Malaysia are heavily subsidized and readily available to the population, CAM use may impact delays in presentation and diagnosis. PMID:28448541

Characterization of feeding-delaying factors from the silkworm Bombyx mori.

PubMed

Nagata, Shinji; Morooka, Nobukatsu; Matsumoto, Sumihiro; Nagasawa, Hiromichi

2009-04-01

In several phytophagous insects, feeding behavior occurs regularly. Recently, we demonstrated that feeding behavior in larvae of the silkworm Bombyx mori had a regular frequency. To address the control of the feeding cycle in B. mori, we aimed to characterize factors influencing feeding initiation and termination. Injection of extracts of the midgut, foregut, and fat body into starved Bombyx larvae delayed the initiation of feeding. This result indicates the presence in these tissues of factors capable of decreasing the likelihood of feeding initiation.

Assessment and management of febrile neutropenia in emergency departments within a regional health authority—a benchmark analysis

PubMed Central

Szwajcer, D.; Czaykowski, P.; Turner, D.

2011-01-01

Objectives Febrile neutropenia is considered an oncologic emergency, for which prompt initiation of antibiotics is essential. Methods We conducted a retrospective cohort study for the 2006 calendar year involving all adult oncology patients presenting with febrile neutropenia to a regional health authority’s emergency departments. The objective was to determine the time from triage to antibiotic administration and its impact on patient outcomes. Results We identified 68 patients presenting with febrile neutropenia, most of whom (76%) were seen in tertiary care centers. Of those patients, 65% were triaged to be seen within 15 minutes of arrival in the emergency room; however, the median time to reassessment was 57 minutes. The median time from triage to antibiotic administration was 5 hours (range: 1.23–22.8 hours). No increased risk of death or increased length of hospital stay was associated with delayed antibiotic administration. Older patients and patients without caregiver support were more likely to experience delayed antibiotic administration (odds ratio: 3.8 and 12.7 respectively). Conclusions We were not able to show a deleterious effect of delay in antibiotic administration, but our analysis identified several points at which patient flow through the emergency room could be improved. PMID:22184489

Human anterior prefrontal cortex encodes the 'what' and 'when' of future intentions.

PubMed

Momennejad, Ida; Haynes, John-Dylan

2012-05-15

On a daily basis we form numerous intentions to perform specific actions. However, we often have to delay the execution of intended actions while engaging in other demanding activities. Previous research has shown that patterns of activity in human prefrontal cortex (PFC) can reveal our current intentions. However, two fundamental questions have remained unresolved: (a) how does the PFC encode information about future tasks while we are busy engaging in other activities, and (b) how does the PFC enable us to commence a stored task at the intended time? Here we investigate how the brain stores and retrieves future intentions during occupied delays, i.e. while a person is busy performing a different task. For this purpose, we conducted a neuroimaging study with a time-based prospective memory paradigm. Using multivariate pattern classification and fMRI we show that during an occupied delay, activity patterns in the anterior PFC encode the content of 'what' subjects intend to do next, and 'when' they intend to do it. Importantly, distinct anterior PFC regions store the 'what' and 'when' components of future intentions during occupied maintenance and self-initiated retrieval. These results show a role for anterior PFC activity patterns in storing future action plans and ensuring their timely retrieval. Copyright © 2012 Elsevier Inc. All rights reserved.

Impact of Introducing the Line Probe Assay on Time to Treatment Initiation of MDR-TB in Delhi, India

PubMed Central

Singla, Neeta; Satyanarayana, Srinath; Sachdeva, Kuldeep Singh; Van den Bergh, Rafael; Reid, Tony; Tayler-Smith, Katherine; Myneedu, V. P.; Ali, Engy; Enarson, Donald A.; Behera, Digamber; Sarin, Rohit

2014-01-01

Setting National Institute of Tuberculosis and Respiratory Diseases (erstwhile Lala Ram Sarup Institute) in Delhi, India. Objectives To evaluate before and after the introduction of the line Probe Assay (LPA) a) the overall time to MDR-TB diagnosis and treatment initiation; b) the step-by-step time lapse at each stage of patient management; and c) the lost to follow-up rates. Methods A retrospective cohort analysis was done using data on MDR-TB patients diagnosed during 2009–2012 under Revised National Tuberculosis Control Programme at the institute. Results Following the introduction of the LPA in 2011, the overall median time from identification of patients suspected for MDR-TB to the initiation of treatment was reduced from 157 days (IQR 127–200) to 38 days (IQR 30–79). This reduction was attributed mainly to a lower diagnosis time at the laboratory. Lost to follow-up rates were also significantly reduced after introduction of the LPA (12% versus 39% pre-PLA). Conclusion Introduction of the LPA was associated with a major reduction in the delay between identification of patients suspected for MDR-TB and initiation of treatment, attributed mainly to a reduction in diagnostic time in the laboratory. PMID:25058124

Compliance with national guidelines for HIV treatment and its association with mortality and treatment outcome: a study in a Spanish cohort.

PubMed

Suárez-García, I; Sobrino-Vegas, P; Tejada, A; Viciana, P; Ribas, Ma; Iribarren, Ja; Díaz Menéndez, M; Rivero, M; Arazo, P; Del Amo, J; Moreno, S

2014-02-01

The aim of the study was to assess the adequacy of initial antiretroviral therapy (ART), in terms of its timing and the choice of regimens, according to the Spanish national treatment guidelines [Spanish AIDS Study Group-National Plan for AIDS (GeSIDA-PNS) Guidelines] for treatment-naïve HIV-infected patients. A prospective cohort study of HIV-positive ART-naïve subjects attending 27 centres in Spain from 2004 to 2010 was carried out. Regimens were classified as recommended, alternative or nonrecommended according to the guidelines. Delayed start of treatment was defined as starting treatment later than 12 months after the patient had fulfilled the treatment criteria. Multivariate logistic and Cox regression analyses were performed. A total of 6225 ART-naïve patients were included in the study. Of 4516 patients who started treatment, 91.5% started with a recommended or alternative treatment. The use of a nonrecommended treatment was associated with a CD4 count > 500 cells/μL [odds ratio (OR) 2.03; 95% confidence interval (CI) 1.14-3.59], hepatitis B (OR 2.23; 95% CI 1.50-3.33), treatment in a hospital with < 500 beds, and starting treatment in the years 2004-2006. Fourteen per cent of the patients had a delayed initiation of treatment. Delayed initiation of treatment was more likely in injecting drug users, patients with hepatitis C, patients with higher CD4 counts and during the years 2004-2006, and it was less likely in patients with viral loads > 5 log HIV-1 RNA copies/ml. The use of a nonrecommended regimen was significantly associated with mortality [hazard ratio (HR) 1.61; 95% CI 1.03-2.52; P = 0.035] and lack of virological response. Compliance with the recommendations of Spanish national guidelines was high with respect to the timing and choice of initial ART. The use of nonrecommended regimens was associated with a lack of virological response and higher mortality. © 2013 British HIV Association.

Improving the transport of urgent specimens to an off-site laboratory using a novel sticker-tracker.

PubMed

Sepahzad, Afsoon; Ejiofor, Florence; Giles, Susan; Klaber, Robert

2013-01-01

Obtaining results for urgent microbiology specimens in an efficient manner is imperative to ensure that patients receive appropriate antibiotic therapy. A previous audit carried out in the Paediatric department of a central teaching hospital and a number of clinical incidents, highlighted a delay in transport of specimens (exceeding eight hours) and 'missing' specimens. This results in empirical antibiotic treatment of infection, with delay in confirming microbiology result and unnecessary, distressing repeat investigation. As an initial step we sought staff opinion to further explore the problem. A sticker was designed for the microbiology specimen bag to assign accountability, track each step in the transport process and to raise awareness of the problem. The sticker required the member of staff responsible at each stage of the process to time, date and sign it, to allow tracking of potential delays. The new sticker tracking system was promoted and launched in the Paediatric department. Initial challenges included lack of awareness of the protocol and lack of pods for sending urgent specimens. The team met regularly and completed stickers were analysed weekly to identify on-going issues and to devise solutions. Consequently total transport time was reduced to an average of 69 minutes by September (within four hr target). Our intervention improved the efficiency and reliability of urgent specimen transport. This is likely to result in safer antibiotic use and avoid the need for repeat investigation. The system is now also used in the Neonatal department and has lead to the development of a new 'Central Specimens Reception'.

Boon and Bane of Inflammation in Bone Tissue Regeneration and Its Link with Angiogenesis.

PubMed

Schmidt-Bleek, Katharina; Kwee, Brian J; Mooney, David J; Duda, Georg N

2015-08-01

Delayed healing or nonhealing of bone is an important clinical concern. Although bone, one of the two tissues with scar-free healing capacity, heals in most cases, healing is delayed in more than 10% of clinical cases. Treatment of such delayed healing condition is often painful, risky, time consuming, and expensive. Tissue healing is a multistage regenerative process involving complex and well-orchestrated steps, which are initiated in response to injury. At best, these steps lead to scar-free tissue formation. At the onset of healing, during the inflammatory phase, stationary and attracted macrophages and other immune cells at the fracture site release cytokines in response to injury. This initial reaction to injury is followed by the recruitment, proliferation, and differentiation of mesenchymal stromal cells, synthesis of extracellular matrix proteins, angiogenesis, and finally tissue remodeling. Failure to heal is often associated with poor revascularization. Since blood vessels mediate the transport of circulating cells, oxygen, nutrients, and waste products, they appear essential for successful healing. The strategy of endogenous regeneration in a tissue such as bone is interesting to analyze since it may represent a blueprint of successful tissue formation. This review highlights the interdependency of the time cascades of inflammation, angiogenesis, and tissue regeneration. A better understanding of these inter-relations is mandatory to early identify patients at risk as well as to overcome critical clinical conditions that limit healing. Instead of purely tolerating the inflammatory phase, modulations of inflammation (immunomodulation) might represent a valid therapeutic strategy to enhance angiogenesis and foster later phases of tissue regeneration.

Occupational Therapy for Patients With Acute Lung Injury: Factors Associated With Time to First Intervention in the Intensive Care Unit

PubMed Central

Dinglas, Victor D.; Colantuoni, Elizabeth; Ciesla, Nancy; Mendez-Tellez, Pedro A.; Shanholtz, Carl

2013-01-01

OBJECTIVE. Very early occupational therapy intervention in the intensive care unit (ICU) improves patients’ physical recovery. We evaluated the association of patient, ICU, and hospital factors with time to first occupational therapy intervention in ICU patients with acute lung injury (ALI). METHOD. We conducted a prospective cohort study of 514 consecutive patients with ALI from 11 ICUs in three hospitals in Baltimore, MD. RESULTS. Only 30% of patients ever received occupational therapy during their ICU stay. Worse organ failure, continuous hemodialysis, and uninterrupted continuous infusion of sedation were independently associated with delayed occupational therapy initiation, and hospital study site and admission to a trauma ICU were independently associated with earlier occupational therapy. CONCLUSION. Severity of illness and ICU practices for sedation administration were associated with delayed occupational therapy. Both hospital study site and type of ICU were independently associated with timing of occupational therapy, indicating modifiable environmental factors for promoting early occupational therapy in the ICU. PMID:23597694

Time course of changes in sperm morphometry and semen variables during testosterone-induced suppression of human spermatogenesis.

PubMed

Garrett, C; Liu, D Y; McLachlan, R I; Baker, H W G

2005-11-01

Quantification of changes in semen may give insight into the testosterone (T)-induced disruption of spermatogenesis in man. A model analogous to flushing of sperm from the genital tract after vasectomy was used to quantify the time course of semen changes in subjects participating in male contraceptive trials using 800 mg T-implant (n = 25) or 200 mg weekly intramuscular injection (IM-T; n = 33). A modified exponential decay model allowed for delayed onset and incomplete disruption to spermatogenesis. Semen variables measured weekly during a 91-day period after initial treatment were fitted to the model. Sperm concentration, total count, motility and morphometry exhibited similar average decay rates (5 day half-life). The mean delay to onset of decline in concentration was 15 (IM-T) and 18 (T-implant) days. The significantly longer (P < 0.005) delays deduced for the commencement of fall in normal morphology (41 days), normal morphometry (40 days) and sperm viability (43 and 55 days), and the change of morphometry to smaller more compact sperm heads are consistent with sperm being progressively cleared from the genital tract rather than continued shedding of immature or abnormal sperm by the seminiferous epithelium. A significant negative relationship was found between lag time and baseline sperm concentration, consistent with longer sperm-epididymal transit times associated with lower daily production rates.

Impact of transfer distance and time on rural brain injury outcomes.

PubMed

Gale, Stephen C; Peters, Joann; Hansen, Ashley; Dombrovskiy, Viktor Y; Detwiler, Paul W

2016-01-01

After rural injury, evaluation at local hospitals with transfer to regional trauma centres may delay definitive care. This study sought to determine the impact of such delays on outcomes in patients with TBI within a mature regional trauma system. The ETMC Level 1 Trauma registry was queried from 2008-2013 for patients with blunt TBI, aged ≥ 18 and admitted ≤ 24 hours from injury and stratified them as 'transfer' vs 'direct' admission. Demographics, transfer distance, transfer times and outcomes were compared using Chi-square, t-test and multivariable logistic regression; p < 0.05 was significant. During the study period, 1845 patients met inclusion criteria: 947 'direct' and 898 'transfers'. For transfers, median distance was 60.1 miles; mean time to initial care was 1.2 ± 2.7 hours and time to Level 1 care was 5.0 ± 2.4 hours. Transfer patients were older (56 vs 49 years; p < 0.01) and had more comorbidities, but had lower mean ISS (15.9 vs 18.8; p < 0.01) and lower mortality (7.0 vs 10.3%; p < 0.03), complications and LOS. Neurosurgical intervention was comparable (p = 0.88), as was mortality for patients with ISS ≥ 15 (12.4% vs 14.8%; p = 0.28). After regression analysis, advanced age and increasing ISS, not distance or time, predicted mortality. Neither transfer distance nor time independently contributed to mortality for TBI after rural injury. An established regional trauma system, with initial local stabilization using ATLS principles, may help reduce negative outcomes for injured patients in rural settings.

Analysis of the temporal program of replication initiation in yeast chromosomes.

PubMed

Friedman, K L; Raghuraman, M K; Fangman, W L; Brewer, B J

1995-01-01

The multiple origins of eukaryotic chromosomes vary in the time of their initiation during S phase. In the chromosomes of Saccharomyces cerevisiae the presence of a functional telomere causes nearby origins to delay initiation until the second half of S phase. The key feature of telomeres that causes the replication delay is the telomeric sequence (C(1-3)A/G(1-3)T) itself and not the proximity of the origin to a DNA end. A second group of late replicating origins has been found at an internal position on chromosome XIV. Four origins, spanning approximately 140 kb, initiate replication in the second half of S phase. At least two of these internal origins maintain their late replication time on circular plasmids. Each of these origins can be separated into two functional elements: those sequences that provide origin function and those that impose late activation. Because the assay for determining replication time is costly and laborious, it has not been possible to analyze in detail these 'late' elements. We report here the development of two new assays for determining replication time. The first exploits the expression of the Escherichia coli dam methylase in yeast and the characteristic period of hemimethylation that transiently follows the passage of a replication fork. The second uses quantitative hybridization to detect two-fold differences in the amount of specific restriction fragments as a function of progress through S phase. The novel aspect of this assay is the creation in vivo of a non-replicating DNA sequence by site-specific pop-out recombination. This non-replicating fragment acts as an internal control for copy number within and between samples. Both of these techniques are rapid and much less costly than the more conventional density transfer experiments that require CsCl gradients to detect replicated DNA. With these techniques it should be possible to identify the sequences responsible for late initiation, to search for other late replicating regions in the genome, and to begin to analyze the effect that altering the temporal program has on chromosome function.

The influence of media type on attitude toward mobile advertisements over time.

PubMed

Sung, Jungyeon; Cho, Kwangsu

2012-01-01

This study explores the relationships between consumers and mobile advertisements on attitude change over time. Two experiments were used to investigate both immediate and delayed effects of different media types on attitudes toward mobile advertisements. Experiment 1 formulated three types of advertisements corresponding to three media types: text, still pictures, and motion pictures. The results indicate that motion pictures on mobile phones significantly influence consumers' initial attitudes toward advertisements. Experiment 2, focusing on delayed effects, was conducted 4 weeks after Experiment 1. Ninety-five of the 117 participants in Experiment 1 were contacted via cellular phone. The results of Experiment 2 showed a decrease in attitude in relation to motion pictures, whereas an increase in attitude in relation to text and still pictures was observed. The findings were interpreted from the perspectives of media characteristics, consumer behavior, and advertising research.

Semantic effects in naming perceptual identification but not in delayed naming: implications for models and tasks.

PubMed

Wurm, Lee H; Seaman, Sean R

2008-03-01

Previous research has demonstrated that the subjective danger and usefulness of words affect lexical decision times. Usually, an interaction is found: Increasing danger predicts faster reaction times (RTs) for words low on usefulness, but increasing danger predicts slower RTs for words high on usefulness. The authors show the same interaction with immediate auditory naming. The interaction disappeared with a delayed auditory naming control experiment, suggesting that it has a perceptual basis. In an attempt to separate input (signal to ear) from output (brain to muscle) processes in word recognition, the authors ran 2 auditory perceptual identification experiments. The interaction was again significant, but performance was best for words high on both danger and usefulness. This suggests that initial demonstrations of the interaction were reflecting an output approach/withdraw response conflict induced by stimuli that are both dangerous and useful. The interaction cannot be characterized as a tradeoff of speed versus accuracy.

Relevance of β-delayed neutron data for reactor, nuclear physics and astrophysics applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kratz, Karl-Ludwig

Initially, yields (or abundances) and branching ratios of β-delayed neutrons (βdn) from fission products (P{sub n}-values) have had their main importance in nuclear reactor control. At that time, the six-group mathematical approximation of the time-dependence of βdn-data in terms of the so-called 'Keepin groups' was generally accepted. Later, with the development of high-resolution neutron spectroscopy, βdn data have provided important information on nuclear-structure properties at intermediate excitation energy in nuclei far from stability, as well as in nuclear astrophysics. In this paper, I will present some examples of the βdn-studies performed by the Kernchemie Mainz group during the past threemore » decades. This work has been recognized as an example of 'broad scientific diversity' which has led to my nomination for the 2014 Hans A. Bethe prize.« less

The Influence of Media Type on Attitude Toward Mobile Advertisements Over Time

PubMed Central

Sung, Jungyeon

2012-01-01

Abstract This study explores the relationships between consumers and mobile advertisements on attitude change over time. Two experiments were used to investigate both immediate and delayed effects of different media types on attitudes toward mobile advertisements. Experiment 1 formulated three types of advertisements corresponding to three media types: text, still pictures, and motion pictures. The results indicate that motion pictures on mobile phones significantly influence consumers' initial attitudes toward advertisements. Experiment 2, focusing on delayed effects, was conducted 4 weeks after Experiment 1. Ninety-five of the 117 participants in Experiment 1 were contacted via cellular phone. The results of Experiment 2 showed a decrease in attitude in relation to motion pictures, whereas an increase in attitude in relation to text and still pictures was observed. The findings were interpreted from the perspectives of media characteristics, consumer behavior, and advertising research. PMID:21988732

Time-to-administration in postoperative chemotherapy for colorectal cancer: does minimally-invasive surgery help?

PubMed

Amore Bonapasta, Stefano; Checcacci, Paolo; Guerra, Francesco; Mirasolo, Vita M; Moraldi, Luca; Ferrara, Angelo; Annecchiarico, Mario; Coratti, Andrea

2016-06-01

The optimal delay in the start of chemotherapy following rectal cancer surgery has not yet been identified. However, postponed adjuvant therapy has been proven to be connected with a significant survival detriment. We aimed to investigate whether the time to initiation of adjuvant treatment can be influenced by the application of minimally invasive surgery rather than traditional open surgery. By comprehensively evaluating the available inherent literature, several factors appear to be associated with delayed postoperative chemotherapy. Some of them are strictly related to surgical short-term outcomes. Laparoscopy results in shortened length of hospital stay, reduced surgical morbidity and lower rate of wound infection compared to conventional surgery. Probably due to such advantages, the application of minimally-invasive surgery to treat rectal malignancies seems to impact favorably the possibility to start adjuvant chemotherapy within an adequate timeframe following surgical resection, with potential improvement in patient survival.

Collisions and Trapping of Time Delayed Solitons in Optical Waveguides with Orthogonally Polarized Modes

NASA Astrophysics Data System (ADS)

Zhou, Huan; Li, Jin-Hua; Chow, Kwok-Wing; Xiao, Shao-Rong; Sun, Ting-Ting

2017-04-01

The interactions and collisions of time delayed solitons in optical waveguides with orthogonally polarized modes are studied. Direct numerical simulations of the coherently coupled nonlinear Schrödinger equations are performed, and neither the high birefringence nor the low birefringence approximations are invoked. Trapping of solitary pulses occurs when the birefringence parameter is small or the four-wave mixing parameter is large. The distance before the first collision depends strongly on the initial separation of the two solitary pulses. Variational techniques are employed to calculate this distance, and results agree with those from the full simulations very well. Supported by the National Natural Science Foundation of China under Grant Nos. 11605090 and 11447113, Natural Science Foundation of Jiangsu Provincial Universities under Grant No. 14KJB140009 and the startup Foundation for Introducing Talent of Nanjing University of Information Science and Technology under Grant No. 2241131301064

Chaos based video encryption using maps and Ikeda time delay system

NASA Astrophysics Data System (ADS)

Valli, D.; Ganesan, K.

2017-12-01

Chaos based cryptosystems are an efficient method to deal with improved speed and highly secured multimedia encryption because of its elegant features, such as randomness, mixing, ergodicity, sensitivity to initial conditions and control parameters. In this paper, two chaos based cryptosystems are proposed: one is the higher-dimensional 12D chaotic map and the other is based on the Ikeda delay differential equation (DDE) suitable for designing a real-time secure symmetric video encryption scheme. These encryption schemes employ a substitution box (S-box) to diffuse the relationship between pixels of plain video and cipher video along with the diffusion of current input pixel with the previous cipher pixel, called cipher block chaining (CBC). The proposed method enhances the robustness against statistical, differential and chosen/known plain text attacks. Detailed analysis is carried out in this paper to demonstrate the security and uniqueness of the proposed scheme.

Optimal time for initiating extracorporeal membrane oxygenation.

PubMed

Haile, Dawit T; Schears, Gregory J

2009-09-01

The technical evolution of extracorporeal membrane oxygenation (ECMO) coincides with the vast improvement in intensive care medicine of the past 4 decades. Extracorporeal circulatory technology substitutes for acutely failed cardiac or pulmonary function until these organs regain sustainable function through goal-oriented intensive care practice. The technology has been validated to improve survival in select patients who would otherwise have 100% mortality. This is by far the most complex life-sustaining technology employed and thus can contribute significant risks such that the decision to institute ECMO requires prompt risk and benefit analysis. Delaying the institution of ECMO may cause irreversible pulmonary and cardiac injuries in addition to other organs. Therefore, the optimal time of initiating ECMO support is crucial to the survival of a critically ill patient.

Whittling Down the Wait Time: Exploring Models to Minimize the Delay from Initial Concern to Diagnosis and Treatment of Autism Spectrum Disorder.

PubMed

Gordon-Lipkin, Eliza; Foster, Jessica; Peacock, Georgina

2016-10-01

The process from initial concerns to diagnosis of autism spectrum disorder (ASD) can be a long and complicated process. The traditional model for evaluation and diagnosis of ASD often consists of long wait-lists and evaluations that result in a 2-year difference between the earliest signs of ASD and mean age of diagnosis. Multiple factors contribute to this diagnostic bottleneck, including time-consuming evaluations, cost of care, lack of providers, and lack of comfort of primary care providers to diagnose autism. This article explores innovative clinical models that have been implemented to address this as well as future directions and opportunities. Copyright © 2016 Elsevier Inc. All rights reserved.

Quality improvement utilizing in-situ simulation for a dual-hospital pediatric code response team.

PubMed

Yager, Phoebe; Collins, Corey; Blais, Carlene; O'Connor, Kathy; Donovan, Patricia; Martinez, Maureen; Cummings, Brian; Hartnick, Christopher; Noviski, Natan

2016-09-01

Given the rarity of in-hospital pediatric emergency events, identification of gaps and inefficiencies in the code response can be difficult. In-situ, simulation-based medical education programs can identify unrecognized systems-based challenges. We hypothesized that developing an in-situ, simulation-based pediatric emergency response program would identify latent inefficiencies in a complex, dual-hospital pediatric code response system and allow rapid intervention testing to improve performance before implementation at an institutional level. Pediatric leadership from two hospitals with a shared pediatric code response team employed the Institute for Healthcare Improvement's (IHI) Breakthrough Model for Collaborative Improvement to design a program consisting of Plan-Do-Study-Act cycles occurring in a simulated environment. The objectives of the program were to 1) identify inefficiencies in our pediatric code response; 2) correlate to current workflow; 3) employ an iterative process to test quality improvement interventions in a safe environment; and 4) measure performance before actual implementation at the institutional level. Twelve dual-hospital, in-situ, simulated, pediatric emergencies occurred over one year. The initial simulated event allowed identification of inefficiencies including delayed provider response, delayed initiation of cardiopulmonary resuscitation (CPR), and delayed vascular access. These gaps were linked to process issues including unreliable code pager activation, slow elevator response, and lack of responder familiarity with layout and contents of code cart. From first to last simulation with multiple simulated process improvements, code response time for secondary providers coming from the second hospital decreased from 29 to 7 min, time to CPR initiation decreased from 90 to 15 s, and vascular access obtainment decreased from 15 to 3 min. Some of these simulated process improvements were adopted into the institutional response while others continue to be trended over time for evidence that observed changes represent a true new state of control. Utilizing the IHI's Breakthrough Model, we developed a simulation-based program to 1) successfully identify gaps and inefficiencies in a complex, dual-hospital, pediatric code response system and 2) provide an environment in which to safely test quality improvement interventions before institutional dissemination. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Time-delayed feedback control of diffusion in random walkers.

PubMed

Ando, Hiroyasu; Takehara, Kohta; Kobayashi, Miki U

2017-07-01

Time delay in general leads to instability in some systems, while specific feedback with delay can control fluctuated motion in nonlinear deterministic systems to a stable state. In this paper, we consider a stochastic process, i.e., a random walk, and observe its diffusion phenomenon with time-delayed feedback. As a result, the diffusion coefficient decreases with increasing delay time. We analytically illustrate this suppression of diffusion by using stochastic delay differential equations and justify the feasibility of this suppression by applying time-delayed feedback to a molecular dynamics model.

Acoustic Signal Processing in Photorefractive Optical Systems.

NASA Astrophysics Data System (ADS)

Zhou, Gan

This thesis discusses applications of the photorefractive effect in the context of acoustic signal processing. The devices and systems presented here illustrate the ideas and optical principles involved in holographic processing of acoustic information. The interest in optical processing stems from the similarities between holographic optical systems and contemporary models for massively parallel computation, in particular, neural networks. An initial step in acoustic processing is the transformation of acoustic signals into relevant optical forms. A fiber-optic transducer with photorefractive readout transforms acoustic signals into optical images corresponding to their short-time spectrum. The device analyzes complex sound signals and interfaces them with conventional optical correlators. The transducer consists of 130 multimode optical fibers sampling the spectral range of 100 Hz to 5 kHz logarithmically. A physical model of the human cochlea can help us understand some characteristics of human acoustic transduction and signal representation. We construct a life-sized cochlear model using elastic membranes coupled with two fluid-filled chambers, and use a photorefractive novelty filter to investigate its response. The detection sensitivity is determined to be 0.3 angstroms per root Hz at 2 kHz. Qualitative agreement is found between the model response and physiological data. Delay lines map time-domain signals into space -domain and permit holographic processing of temporal information. A parallel optical delay line using dynamic beam coupling in a rotating photorefractive crystal is presented. We experimentally demonstrate a 64 channel device with 0.5 seconds of time-delay and 167 Hz bandwidth. Acoustic signal recognition is described in a photorefractive system implementing the time-delay neural network model. The system consists of a photorefractive optical delay-line and a holographic correlator programmed in a LiNbO_3 crystal. We demonstrate the recognition of synthesized chirps as well as spoken words. A photorefractive ring resonator containing an optical delay line can learn temporal information through self-organization. We experimentally investigate a system that learns by itself and picks out the most-frequently -presented signals from the input. We also give results demonstrating the separation of two orthogonal temporal signals into two competing ring resonators.

Delay in seeking medical help following Transient Ischemic Attack (TIA) or "mini-stroke": a qualitative study.

PubMed

Mc Sharry, Jennifer; Baxter, Alison; Wallace, Louise M; Kenton, Anthony; Turner, Andrew; French, David P

2014-01-01

Prompt treatment following Transient Ischemic Attack (TIA) can reduce the risk of subsequent stroke and disability. However, many patients delay in making contact with medical services. This study aimed to explore TIA patients' accounts of delay between symptom onset and contacting medical services including how decisions to contact services were made and the factors discussed in relation to delay. Twenty interviews were conducted with TIA patients in England. Using a previous systematic review as an initial framework, interview data were organised into categories of symptom recognition, presence of others and type of care sought. A thematic analysis was then conducted to explore descriptions of care-seeking relevant to each category. Delay in contacting medical services varied from less than an hour to eight days. Awareness of typical stroke symptoms could lead to urgent action when more severe TIA symptoms were present but could lead to delay when experienced symptoms were less severe. The role of friends and family varied widely from deciding on and enacting care-seeking decisions to simply providing transport to the GP practice. When family or friends played a greater role, and both made and enacted care-seeking decisions, delays were often shorter, even when patients themselves failed to identify symptoms. Healthcare professionals also impacted on patients' care-seeking with greater delays in seeking further care for the same episode described when patients perceived a lack of urgency during initial healthcare interactions. This study provides new information on patients' decisions to contact medical services following TIA and identifies overlapping factors that can lead to delay in receiving appropriate treatment. While recognition of symptoms may contribute to delay in contacting medical services, additional factors, including full responsibility being taken by others and initial healthcare interactions, can over-ride or undermine the importance of patients' own identification of TIA.

Delay in Seeking Medical Help following Transient Ischemic Attack (TIA) or “Mini-Stroke”: A Qualitative Study

PubMed Central

Mc Sharry, Jennifer; Baxter, Alison; Wallace, Louise M.; Kenton, Anthony; Turner, Andrew; French, David P.

2014-01-01

Background Prompt treatment following Transient Ischemic Attack (TIA) can reduce the risk of subsequent stroke and disability. However, many patients delay in making contact with medical services. This study aimed to explore TIA patients' accounts of delay between symptom onset and contacting medical services including how decisions to contact services were made and the factors discussed in relation to delay. Methods Twenty interviews were conducted with TIA patients in England. Using a previous systematic review as an initial framework, interview data were organised into categories of symptom recognition, presence of others and type of care sought. A thematic analysis was then conducted to explore descriptions of care-seeking relevant to each category. Results Delay in contacting medical services varied from less than an hour to eight days. Awareness of typical stroke symptoms could lead to urgent action when more severe TIA symptoms were present but could lead to delay when experienced symptoms were less severe. The role of friends and family varied widely from deciding on and enacting care-seeking decisions to simply providing transport to the GP practice. When family or friends played a greater role, and both made and enacted care-seeking decisions, delays were often shorter, even when patients themselves failed to identify symptoms. Healthcare professionals also impacted on patients' care-seeking with greater delays in seeking further care for the same episode described when patients perceived a lack of urgency during initial healthcare interactions. Conclusions This study provides new information on patients' decisions to contact medical services following TIA and identifies overlapping factors that can lead to delay in receiving appropriate treatment. While recognition of symptoms may contribute to delay in contacting medical services, additional factors, including full responsibility being taken by others and initial healthcare interactions, can over-ride or undermine the importance of patients' own identification of TIA. PMID:25137185

Repair of Chronic Tibialis Anterior Tendon Rupture With a Major Defect Using Gracilis Allograft.

PubMed

Burton, Alex; Aydogan, Umur

2016-08-01

Tibialis anterior tendon (TAT) rupture is an uncommon injury, however, it can cause substantial deficit. Diagnosis is often delayed due to lack of initial symptoms; yet loss of function over time typically causes the patient to present for treatment. This delay usually ends up with major defects creating a great technical challenge for the operating surgeon. We present a novel technique and operative algorithm for the management of chronic TAT ruptures with a major gap after a delayed diagnosis not otherwise correctable with currently described techniques in the literature. This technique has been performed in 4 cases without any complications with fairly successful functional outcomes. For the reconstruction of chronic TAT rupture with an average delay of nine weeks after initial injury and gap of greater than 10 cm, a thorough operative algorithm was implemented in 4 patients using a double bundle gracilis allograft. Patients were then kept nonweightbearing for 6 weeks followed by weightbearing as tolerated. They began physical therapy with a focus on ankle exercises and gradual return to normal activity at 8 weeks, with resistance training exercises allowed at 12 weeks. At a mean follow-up time of 24.5 months, all patients reported significant pain relief with normal gait pattern. There were no reported intra- or postoperative complications. The average Foot and Ankle Ability Measure score increased to 90 from 27.5 in the postoperative period. All patients were able to return their previous activity levels. Gracilis allograft reconstruction as used in this study is a viable and reproducible alternative to primary repair with postoperative results being favorable without using complex tendon transfer techniques or autograft use necessitating the functional sacrifice of transferred or excised tendon. To the best of our knowledge, this is the first study demonstrating a successful technique and operative algorithm of gracilis allograft reconstruction of the TAT with a substantial deficit of greater than 10 cm with favorable results. Level IV: Operative algorithm with case series. © 2016 The Author(s).

Adjuvant Radiation Therapy Treatment Time Impacts Overall Survival in Gastric Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMillan, Matthew T.; Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Ojerholm, Eric

Purpose: Prolonged radiation therapy treatment time (RTT) is associated with worse survival in several tumor types. This study investigated whether delays during adjuvant radiation therapy impact overall survival (OS) in gastric cancer. Methods and Materials: The National Cancer Data Base was queried for patients with resected gastric cancer who received adjuvant radiation therapy with National Comprehensive Cancer Network–recommended doses (45 or 50.4 Gy) between 1998 and 2006. RTT was classified as standard (45 Gy: 33-36 days, 50.4 Gy: 38-41 days) or prolonged (45 Gy: >36 days, 50.4 Gy: >41 days). Cox proportional hazards models evaluated the association between the following factors and OS: RTT, interval from surgery to radiationmore » therapy initiation, interval from surgery to radiation therapy completion, radiation therapy dose, demographic/pathologic and operative factors, and other elements of adjuvant multimodality therapy. Results: Of 1591 patients, RTT was delayed in 732 (46%). Factors associated with prolonged RTT were non-private health insurance (OR 1.3, P=.005) and treatment at non-academic facilities (OR 1.2, P=.045). Median OS and 5-year actuarial survival were significantly worse in patients with prolonged RTT compared with standard RTT (36 vs 51 months, P=.001; 39 vs 47%, P=.005); OS worsened with each cumulative week of delay (P<.0004). On multivariable analysis, prolonged RTT was associated with inferior OS (hazard ratio 1.2, P=.002); the intervals from surgery to radiation therapy initiation or completion were not. Prolonged RTT was particularly detrimental in patients with node positivity, inadequate nodal staging (<15 nodes examined), and those undergoing a cycle of chemotherapy before chemoradiation therapy. Conclusions: Delays during adjuvant radiation therapy appear to negatively impact survival in gastric cancer. Efforts to minimize cumulative interruptions to <7 days should be considered.« less

Anchorage Arrival Scheduling Under Off-Nominal Weather Conditions

NASA Technical Reports Server (NTRS)

Grabbe, Shon; Chan, William N.; Mukherjee, Avijit

2012-01-01

Weather can cause flight diversions, passenger delays, additional fuel consumption and schedule disruptions at any high volume airport. The impacts are particularly acute at the Ted Stevens Anchorage International Airport in Anchorage, Alaska due to its importance as a major international portal. To minimize the impacts due to weather, a multi-stage scheduling process is employed that is iteratively executed, as updated aircraft demand and/or airport capacity data become available. The strategic scheduling algorithm assigns speed adjustments for flights that originate outside of Anchorage Center to achieve the proper demand and capacity balance. Similarly, an internal departure-scheduling algorithm assigns ground holds for pre-departure flights that originate from within Anchorage Center. Tactical flight controls in the form of airborne holding are employed to reactively account for system uncertainties. Real-world scenarios that were derived from the January 16, 2012 Anchorage visibility observations and the January 12, 2012 Anchorage arrival schedule were used to test the initial implementation of the scheduling algorithm in fast-time simulation experiments. Although over 90% of the flights in the scenarios arrived at Anchorage without requiring any delay, pre-departure scheduling was the dominant form of control for Anchorage arrivals. Additionally, tactical scheduling was used extensively in conjunction with the pre-departure scheduling to reactively compensate for uncertainties in the arrival demand. For long-haul flights, the strategic scheduling algorithm performed best when the scheduling horizon was greater than 1,000 nmi. With these long scheduling horizons, it was possible to absorb between ten and 12 minutes of delay through speed control alone. Unfortunately, the use of tactical scheduling, which resulted in airborne holding, was found to increase as the strategic scheduling horizon increased because of the additional uncertainty in the arrival times of the aircraft. Findings from these initial experiments indicate that it is possible to schedule arrivals into Anchorage with minimal delays under low-visibility conditions with less disruption to high-cost, international flights.

Speech and language support: How physicians can identify and treat speech and language delays in the office setting

PubMed Central

Moharir, Madhavi; Barnett, Noel; Taras, Jillian; Cole, Martha; Ford-Jones, E Lee; Levin, Leo

2014-01-01

Failure to recognize and intervene early in speech and language delays can lead to multifaceted and potentially severe consequences for early child development and later literacy skills. While routine evaluations of speech and language during well-child visits are recommended, there is no standardized (office) approach to facilitate this. Furthermore, extensive wait times for speech and language pathology consultation represent valuable lost time for the child and family. Using speech and language expertise, and paediatric collaboration, key content for an office-based tool was developed. The tool aimed to help physicians achieve three main goals: early and accurate identification of speech and language delays as well as children at risk for literacy challenges; appropriate referral to speech and language services when required; and teaching and, thus, empowering parents to create rich and responsive language environments at home. Using this tool, in combination with the Canadian Paediatric Society’s Read, Speak, Sing and Grow Literacy Initiative, physicians will be better positioned to offer practical strategies to caregivers to enhance children’s speech and language capabilities. The tool represents a strategy to evaluate speech and language delays. It depicts age-specific linguistic/phonetic milestones and suggests interventions. The tool represents a practical interim treatment while the family is waiting for formal speech and language therapy consultation. PMID:24627648

Route Optimization for Offloading Congested Meter Fixes

NASA Technical Reports Server (NTRS)

Xue, Min; Zelinski, Shannon

2016-01-01

The Optimized Route Capability (ORC) concept proposed by the FAA facilitates traffic managers to identify and resolve arrival flight delays caused by bottlenecks formed at arrival meter fixes when there exists imbalance between arrival fixes and runways. ORC makes use of the prediction capability of existing automation tools, monitors the traffic delays based on these predictions, and searches the best reroutes upstream of the meter fixes based on the predictions and estimated arrival schedules when delays are over a predefined threshold. Initial implementation and evaluation of the ORC concept considered only reroutes available at the time arrival congestion was first predicted. This work extends previous work by introducing an additional dimension in reroute options such that ORC can find the best time to reroute and overcome the 'firstcome- first-reroute' phenomenon. To deal with the enlarged reroute solution space, a genetic algorithm was developed to solve this problem. Experiments were conducted using the same traffic scenario used in previous work, when an arrival rush was created for one of the four arrival meter fixes at George Bush Intercontinental Houston Airport. Results showed the new approach further improved delay savings. The suggested route changes from the new approach were on average 30 minutes later than those using other approaches, and fewer numbers of reroutes were required. Fewer numbers of reroutes reduce operational complexity and later reroutes help decision makers deal with uncertain situations.

Amphetamine increases schedule-induced drinking reduced by negative punishment procedures.

PubMed

Pérez-Padilla, Angeles; Pellón, Ricardo

2003-05-01

d-Amphetamine has been reported to increase schedule-induced drinking punished by lick-dependent signalled delays in food delivery. This might reflect a drug-behaviour interaction dependent on the type of punisher, because no such effect has been found when drinking was reduced by lick-contingent electric shocks. However, the anti-punishment effect of amphetamine could be mediated by other behavioural processes, such as a loss of discriminative control or an increase in the value of delayed reinforcers. To test the effects of d-amphetamine on the acquisition and maintenance of schedule-induced drinking reduced by unsignalled delays in food delivery. Rats received 10-s unsignalled delays initiated by each lick after polydipsia was induced by a fixed-time 30-s food reinforcement schedule or from the outset of the experiment. Yoked-control rats received these same delays but independently of their own behaviour. d-Amphetamine (0.1-3.0 mg/kg) was then tested IP. d-Amphetamine dose-dependently increased and then decreased punished schedule-induced drinking. The drug led to dose-dependent reductions when the delays were not contingent or when they were applied from the outset of training. These results support the contention that d-amphetamine has an increasing effect on schedule-induced drinking that has been previously reduced by a negative punishment procedure. This effect cannot be attributed to other potentially involved processes, and therefore support the idea that drug effects on punished behaviour depend on punishment being delays in food or shock deliveries.

Use of a remote clinical decision support service for a multicenter trial to implement prediction rules for children with minor blunt head trauma.

PubMed

Goldberg, Howard S; Paterno, Marilyn D; Grundmeier, Robert W; Rocha, Beatriz H; Hoffman, Jeffrey M; Tham, Eric; Swietlik, Marguerite; Schaeffer, Molly H; Pabbathi, Deepika; Deakyne, Sara J; Kuppermann, Nathan; Dayan, Peter S

2016-03-01

To evaluate the architecture, integration requirements, and execution characteristics of a remote clinical decision support (CDS) service used in a multicenter clinical trial. The trial tested the efficacy of implementing brain injury prediction rules for children with minor blunt head trauma. We integrated the Epic(®) electronic health record (EHR) with the Enterprise Clinical Rules Service (ECRS), a web-based CDS service, at two emergency departments. Patterns of CDS review included either a delayed, near-real-time review, where the physician viewed CDS recommendations generated by the nursing assessment, or a real-time review, where the physician viewed recommendations generated by their own documentation. A backstopping, vendor-based CDS triggered with zero delay when no recommendation was available in the EHR from the web-service. We assessed the execution characteristics of the integrated system and the source of the generated recommendations viewed by physicians. The ECRS mean execution time was 0.74 ±0.72 s. Overall execution time was substantially different at the two sites, with mean total transaction times of 19.67 and 3.99 s. Of 1930 analyzed transactions from the two sites, 60% (310/521) of all physician documentation-initiated recommendations and 99% (1390/1409) of all nurse documentation-initiated recommendations originated from the remote web service. The remote CDS system was the source of recommendations in more than half of the real-time cases and virtually all the near-real-time cases. Comparisons are limited by allowable variation in user workflow and resolution of the EHR clock. With maturation and adoption of standards for CDS services, remote CDS shows promise to decrease time-to-trial for multicenter evaluations of candidate decision support interventions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effects of ventrolateral thalamic nucleus cooling on initiation of forelimb ballistic flexion movements by conditioned cats.

PubMed

Bénita, M; Condé, H; Dormont, J F; Schmied, A

1979-02-15

Five cats were trained to perform a forelimb ballistic flexion on a reaction time paradigm including an upper limit of about 400 ms for reinforcement (food pellets). They were implanted with a cyrogenic probe thermically insulated, except at the tip, by a vacuum jacket (outer diameter, 1.1 mm). Four cats had the probe inserted into the ventrolateral thalamic nucleus (VL), contralateral to the moving limb. During cooling they showed increased reaction times, which remained constant throughout daily sessions performed during many weeks, independent of the foreperiod but varying from 25 to 100 ms according to the subject. The temperatures used to upset the reaction times varied from +10 decrees C to -8 degrees C, depending on the localisation of the probe and on the insulation of the silver tip used to prevent nervous tissue reaction, but for each subject the reaction times always increased when the temperature was lowered. The fifth cat, with a probe inserted between VL and the Centre Median, showed a decrease of reaction times on cooling to 0 degrees C and an increase of the reaction times for a cooling at -10 degrees C. For one of the four cats with a probe properly inserted into the VL, strain-gauges were stuck on the lever to measure the latency of the decrease of the pressure exerted by the subject when the subject initiated the forelimb flexion in response to the CS. Reaction times and latencies of pressure changes were closely correlated with the movement onset, and they were equally delayed during cooling. This result demonstrates that it is not by slowing down movement velocity that reaction times are upset during VL cooling but by delaying the movement onset.

Profile of referrals for early childhood developmental delay to ambulatory subspecialty clinics.

PubMed

Shevell, M I; Majnemer, A; Rosenbaum, P; Abrahamowicz, M

2001-09-01

The objective of this study was to determine the profile and pattern of referral to subspecialty clinics of young children with suspected developmental delay together with the factors prompting their referral. All children under 5 years of age referred to either developmental pediatrics or pediatric neurology clinics at a single tertiary hospital over an 18-month period were prospectively identified. Standardized demographic and referral information were collected at intake, final developmental delay subtype diagnosed was identified, and referring physicians were surveyed regarding factors prompting referral. A total of 224 children met study criteria. There was a marked male preponderance (166/224), especially among those with either cognitive or language delay. Two delay subtypes, global developmental delay and developmental language disorder, accounted for two thirds of the diagnoses made. For slightly more than one third of the children (75/224), the delay subtype diagnosed following specialty evaluation was different from that initially suspected by the referring physician. A mean delay of 15.5 months was observed for the cohort as a whole between initial parental concern and specialty assessment. For referring physicians, the major factor prompting referral was the severity of the observed delay. The most important aspects of the specialty evaluation according to referral sources were the identification of a possible etiology and confirmation of delay. A profile of referrals and the rationale thereof for a cohort of children with suspected developmental delay is presented that, although locale specific, has implications for service provision and training.

Effects of partial time delays on phase synchronization in Watts-Strogatz small-world neuronal networks

NASA Astrophysics Data System (ADS)

Sun, Xiaojuan; Perc, Matjaž; Kurths, Jürgen

2017-05-01

In this paper, we study effects of partial time delays on phase synchronization in Watts-Strogatz small-world neuronal networks. Our focus is on the impact of two parameters, namely the time delay τ and the probability of partial time delay pdelay, whereby the latter determines the probability with which a connection between two neurons is delayed. Our research reveals that partial time delays significantly affect phase synchronization in this system. In particular, partial time delays can either enhance or decrease phase synchronization and induce synchronization transitions with changes in the mean firing rate of neurons, as well as induce switching between synchronized neurons with period-1 firing to synchronized neurons with period-2 firing. Moreover, in comparison to a neuronal network where all connections are delayed, we show that small partial time delay probabilities have especially different influences on phase synchronization of neuronal networks.

Effect of time delay on surgical performance during telesurgical manipulation.

PubMed

Fabrizio, M D; Lee, B R; Chan, D Y; Stoianovici, D; Jarrett, T W; Yang, C; Kavoussi, L R

2000-03-01

Telementoring allows a less experienced surgeon to benefit from an expert surgical consultation, reducing cost, travel, and the learning curve associated with new procedures. However, there are several technical limitations that affect practical applications. One potentially serious problem is the time delay that occurs any time data are transferred across long distances. To date, the effect of time delay on surgical performance has not been studied. A two-phase trial was designed to examine the effect of time delay on surgical performance. In the first phase, a series of tasks was performed, and the numbers of robotic movements required for completion was counted. Programmed incremental time delays were made in audiovisual acquisition and robotic controls. The number of errors made while performing each task at various time delay intervals was noted. In the second phase, a remote surgeon in Baltimore performed the tasks 9000 miles away in Singapore. The number of errors made was recorded. As the time delay increased, the number of operator errors increased. The accuracy needed to perform remote robotic procedures was diminished as the time delay increased. A learning curve did exist for each task, but as the time delay interval increased, it took longer to complete the task. Time delay does affect surgical performance. There is an acceptable delay of <700 msec in which surgeons can compensate for this phenomenon. Clinical studies will be needed to evaluate the true impact of time delay.

Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays.

PubMed

Chen, Chuan; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2017-01-01

Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don't include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs) with both discrete delay and distributed delay (mixed delays). By means of a simple feedback controller and novel finite time synchronization analysis methods, several new criteria are derived to ensure the finite time synchronization of MCGNNs with mixed delays. The obtained criteria are very concise and easy to verify. Numerical simulations are presented to demonstrate the effectiveness of our theoretical results.

Effects of Annealing Treatment Prior to Cold Rolling on Delayed Fracture Properties in Ferrite-Austenite Duplex Lightweight Steels

NASA Astrophysics Data System (ADS)

Sohn, Seok Su; Song, Hyejin; Kim, Jung Gi; Kwak, Jai-Hyun; Kim, Hyoung Seop; Lee, Sunghak

2016-02-01

Tensile properties of recently developed automotive high-strength steels containing about 10 wt pct of Mn and Al are superior to other conventional steels, but the active commercialization has been postponed because they are often subjected to cracking during formation or to the delayed fracture after formation. Here, the delayed fracture behavior of a ferrite-austenite duplex lightweight steel whose microstructure was modified by a batch annealing treatment at 1023 K (750 °C) prior to cold rolling was examined by HCl immersion tests of cup specimens, and was compared with that of an unmodified steel. After the batch annealing, band structures were almost decomposed as strong textures of {100}<011> α-fibers and {111}<112> γ-fibers were considerably dissolved, while ferrite grains were refined. The steel cup specimen having this modified microstructure was not cracked when immersed in an HCl solution for 18 days, whereas the specimen having unmodified microstructure underwent the delayed fracture within 1 day. This time delayed fracture was more critically affected by difference in deformation characteristics such as martensitic transformation and deformation inhomogeneity induced from concentration of residual stress or plastic strain, rather than the difference in initial microstructures. The present work gives a promise for automotive applications requiring excellent mechanical and delayed fracture properties as well as reduced specific weight.

Time-delayed chameleon: Analysis, synchronization and FPGA implementation

NASA Astrophysics Data System (ADS)

Rajagopal, Karthikeyan; Jafari, Sajad; Laarem, Guessas

2017-12-01

In this paper we report a time-delayed chameleon-like chaotic system which can belong to different families of chaotic attractors depending on the choices of parameters. Such a characteristic of self-excited and hidden chaotic flows in a simple 3D system with time delay has not been reported earlier. Dynamic analysis of the proposed time-delayed systems are analysed in time-delay space and parameter space. A novel adaptive modified functional projective lag synchronization algorithm is derived for synchronizing identical time-delayed chameleon systems with uncertain parameters. The proposed time-delayed systems and the synchronization algorithm with controllers and parameter estimates are then implemented in FPGA using hardware-software co-simulation and the results are presented.

Inducible defense against pathogens and parasites: optimal choice among multiple options.

PubMed

Shudo, E; Iwasa, Y

2001-03-21

Defense against pathogen, parasites and herbivores is often enhanced after their invasion into the host's body. Sometimes different options are adopted depending on the identity and the quantity of the pathogen, exemplified by the switch between Th1 and Th2 systems in mammalian immunity. In this paper, we study the optimal defense of the host when two alternative responses are available, which differ in the effectiveness of suppressing the growth of pathogen (parasite, or herbivore), the damage to the host caused by the defense response, and the magnitude of time delay before the defense response becomes fully effective. The optimal defense is the one that minimizes the sum of the damages caused by the pathogen and the cost due to defense activities. The damage by pathogens increases in proportion to the time integral of the pathogen abundance, and the cost is proportional to the defense activity. We can prove that a single globally optimal combination of defense options always exists and there is no other local optimum. Depending on the parameters, the optimal is to adopt only the early response, only the late response, or both responses. The defense response with a shorter time delay is more heavily used when the pathogen grows fast, the initial pathogen abundance is large, and the difference in time delay is long. We also study the host's optimal choice between constitutive and inducible defenses. In the constitutive defense, the response to pathogen attack works without delay, but it causes the cost even when the pathogen attack does not occur. We discuss mammalian immunity and the plant chemical defense from the model's viewpoint. Copyright 2001 Academic Press.

Chronologic Evaluation of Cerebral Hemodynamics by Dynamic Susceptibility Contrast Magnetic Resonance Imaging After Indirect Bypass Surgery for Moyamoya Disease.

PubMed

Ishii, Yosuke; Tanaka, Yoji; Momose, Toshiya; Yamashina, Motoshige; Sato, Akihito; Wakabayashi, Shinichi; Maehara, Taketoshi; Nariai, Tadashi

2017-12-01

Although indirect bypass surgery is an effective treatment option for patients with ischemic-onset moyamoya disease (MMD), the time point after surgery at which the patient's hemodynamic status starts to improve and the time point at which the improvement reaches a maximum have not been known. The objective of the present study is to evaluate the hemodynamic status time course after indirect bypass surgery for MMD, using dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI). We retrospectively analyzed the cases of 25 patients with MMD (37 sides; mean age, 14.7 years; range, 3-36 years) who underwent indirect bypass surgery and repeated DSC-MRI measurement within 6 months after the operation. The difference in the mean transit time (MTT) between the target regions and the control region (cerebellum) was termed the MTT delay, and we measured the MTT delay's chronologic changes after surgery. The postoperative MTT delay was 1.81 ± 1.16 seconds within 1 week after surgery, 1.57 ± 1.01 at weeks 1-2, 1.55 ± 0.68 at weeks 2-4, 1.32 ± 0.68 at months 1-2, 0.95 ± 0.32 at months 2-3, and 0.77 ± 0.33 at months 3-6. Compared with the preoperative value (2.11 ± 0.98 seconds), the MTT delay decreased significantly from 2 to 4 weeks after surgery (P < 0.05). The amelioration of cerebral hemodynamics by indirect bypass surgery began soon after surgery and gradually reached a maximum at 3 months after surgery. DSC-MRI detected small changes in hemodynamic improvement, which are suspected to be caused by the initiation of angiogenesis and arteriogenesis in the early postoperative period. Copyright © 2017. Published by Elsevier Inc.

H0LiCOW - I. H0 Lenses in COSMOGRAIL's Wellspring: program overview

NASA Astrophysics Data System (ADS)

Suyu, S. H.; Bonvin, V.; Courbin, F.; Fassnacht, C. D.; Rusu, C. E.; Sluse, D.; Treu, T.; Wong, K. C.; Auger, M. W.; Ding, X.; Hilbert, S.; Marshall, P. J.; Rumbaugh, N.; Sonnenfeld, A.; Tewes, M.; Tihhonova, O.; Agnello, A.; Blandford, R. D.; Chen, G. C.-F.; Collett, T.; Koopmans, L. V. E.; Liao, K.; Meylan, G.; Spiniello, C.

2017-07-01

Strong gravitational lens systems with time delays between the multiple images allow measurements of time-delay distances, which are primarily sensitive to the Hubble constant that is key to probing dark energy, neutrino physics and the spatial curvature of the Universe, as well as discovering new physics. We present H0LiCOW (H0 Lenses in COSMOGRAIL's Wellspring), a program that aims to measure H0 with <3.5 per cent uncertainty from five lens systems (B1608+656, RXJ1131-1231, HE 0435-1223, WFI2033-4723 and HE 1104-1805). We have been acquiring (1) time delays through COSMOGRAIL and Very Large Array monitoring, (2) high-resolution Hubble Space Telescope imaging for the lens mass modelling, (3) wide-field imaging and spectroscopy to characterize the lens environment and (4) moderate-resolution spectroscopy to obtain the stellar velocity dispersion of the lenses for mass modelling. In cosmological models with one-parameter extension to flat Λ cold dark matter, we expect to measure H0 to <3.5 per cent in most models, spatial curvature Ωk to 0.004, w to 0.14 and the effective number of neutrino species to 0.2 (1σ uncertainties) when combined with current cosmic microwave background (CMB) experiments. These are, respectively, a factor of ˜15, ˜2 and ˜1.5 tighter than CMB alone. Our data set will further enable us to study the stellar initial mass function of the lens galaxies, and the co-evolution of supermassive black holes and their host galaxies. This program will provide a foundation for extracting cosmological distances from the hundreds of time-delay lenses that are expected to be discovered in current and future surveys.

Postural adjustment errors reveal deficits in inhibition during lateral step initiation in older adults

PubMed Central

Fuhrman, Susan I.; Redfern, Mark S.; Jennings, J. Richard; Perera, Subashan; Nebes, Robert D.; Furman, Joseph M.

2013-01-01

Postural dual-task studies have demonstrated effects of various executive function components on gait and postural control in older adults. The purpose of the study was to explore the role of inhibition during lateral step initiation. Forty older adults participated (range 70–94 yr). Subjects stepped to the left or right in response to congruous and incongruous visual cues that consisted of left and right arrows appearing on left or right sides of a monitor. The timing of postural adjustments was identified by inflection points in the vertical ground reaction forces (VGRF) measured separately under each foot. Step responses could be classified into preferred and nonpreferred step behavior based on the number of postural adjustments that were made. Delays in onset of the first postural adjustment (PA1) and liftoff (LO) of the step leg during preferred steps progressively increased among the simple, choice, congruous, and incongruous tasks, indicating interference in processing the relevant visuospatial cue. Incongruous cues induced subjects to make more postural adjustments than they typically would (i.e., nonpreferred steps), representing errors in selection of the appropriate motor program. During these nonpreferred steps, the onset of the PA1 was earlier than during the preferred steps, indicating a failure to inhibit an inappropriate initial postural adjustment. The functional consequence of the additional postural adjustments was a delay in the LO compared with steps in which they did not make an error. These results suggest that deficits in inhibitory function may detrimentally affect step decision processing, by delaying voluntary step responses. PMID:23114211

Is there an association between suicide attempt and delay of initiation of mood stabilizers in bipolar I disorder?

PubMed

Nery-Fernandes, Fabiana; Quarantini, Lucas C; Guimarães, José L; de Oliveira, Irismar R; Koenen, Karestan C; Kapczinski, Flavio; Miranda-Scippa, Ângela

2012-02-01

Little is known about the extent to which delay of initiation of mood-stabilizing treatment may influence outcomes in bipolar patients (BP). In this study, our aim was to investigate the association between delay of mood stabilizer treatment in bipolar patients and lifetime history of suicide attempts. A consecutive sample of 268 bipolar I outpatients from two teaching hospitals in Brazil was recruited. The assessment included a socio-demographic history form, a clinical interview regarding clinical variables and the Structured Clinical Interview for DSM-IV. Participants were divided into three groups: BP that initiated the first mood stabilizer in the same year of the first episode of the disease (FMS≤1), between 1 and 5 years after the first episode of the disease (15). The mean time from the first episode until the first mood stabilizer medication was 8.6 years (SD 9.8 years). The FMS>5 group, showed a higher lifetime prevalence of suicide attempts than the other two groups (PR=1.75, 95% CI: 1.24-2.47), p=0.001. These results remained significant after adjusting for potential confounders, (PR=1.82, 95% CI: 1.29-2.60), p=0.001. This study evaluated patients retrospectively and does not permit a cause-effect relationship. The present study supports the importance of early diagnosis and early intervention for BP in order to limit the potentially lethal impact of the disease. Copyright © 2011 Elsevier B.V. All rights reserved.

Effects of the "Circle of Life" HIV-prevention program on marijuana use among American Indian middle school youths: a group randomized trial in a Northern Plains tribe.

PubMed

Asdigian, Nancy L; Whitesell, Nancy Rumbaugh; Keane, Ellen M; Mousseau, Alicia C; Kaufman, Carol E

2018-01-01

Early substance use threatens many American Indian/Alaska Native (AI/AN) communities, as it is a risk factor for maladaptive use and adverse health outcomes. Marijuana is among the first substances used by AI/AN youth, and its use becomes widespread during adolescence. Interventions that delay or reduce marijuana use hold the promise of curbing substance disorders and other health risk disparities in AI/AN populations. We evaluated the effectiveness of the Circle of Life (COL) program in reducing marijuana use among young AI adolescents. COL is a culturally tailored, theory-based human immunodeficiency virus (HIV) and sexually transmitted disease (STD) intervention shown to delay sexual initiation among AI youths. We conducted secondary analyses of data from a school-based group randomized trial conducted between 2006 and 2007 in all 13 middle schools on a rural, Northern Plains reservation (N = 635, 47% female). We used discrete-time survival analysis (DTSA) to assess COL effectiveness on risk of marijuana initiation among AI youths and latent growth curve modeling (LGCM) to evaluate effects on frequency of marijuana use over time. DTSA models showed that the overall risk of marijuana initiation was 17.3% lower in the COL group compared to the control group. No intervention effect on frequency of marijuana use emerged in LGCM analyses. COL is a multifaceted, culturally tailored, skills-based program effective in preventing marijuana uptake among AI youth.

Efficacy of Single and Combined Antibiotic Treatments of Anthrax in Rabbits.

PubMed

Weiss, Shay; Altboum, Zeev; Glinert, Itai; Schlomovitz, Josef; Sittner, Assa; Bar-David, Elad; Kobiler, David; Levy, Haim

2015-12-01

Respiratory anthrax is a fatal disease in the absence of early treatment with antibiotics. Rabbits are highly susceptible to infection with Bacillus anthracis spores by intranasal instillation, succumbing within 2 to 4 days postinfection. This study aims to test the efficiency of antibiotic therapy to treat systemic anthrax in this relevant animal model. Delaying the initiation of antibiotic administration to more than 24 h postinfection resulted in animals with systemic anthrax in various degrees of bacteremia and toxemia. As the onset of symptoms in humans was reported to start on days 1 to 7 postexposure, delaying the initiation of treatment by 24 to 48 h (time frame for mass distribution of antibiotics) may result in sick populations. We evaluated the efficacy of antibiotic administration as a function of bacteremia levels at the time of treatment initiation. Here we compare the efficacy of treatment with clarithromycin, amoxicillin-clavulanic acid (Augmentin), imipenem, vancomycin, rifampin, and linezolid to the previously reported efficacy of doxycycline and ciprofloxacin. We demonstrate that treatment with amoxicillin-clavulanic acid, imipenem, vancomycin, and linezolid were as effective as doxycycline and ciprofloxacin, curing rabbits exhibiting bacteremia levels of up to 10(5) CFU/ml. Clarithromycin and rifampin were shown to be effective only as a postexposure prophylactic treatment but failed to treat the systemic (bacteremic) phase of anthrax. Furthermore, we evaluate the contribution of combined treatment of clindamycin and ciprofloxacin, which demonstrated improvement in efficacy compared to ciprofloxacin alone. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

The time delay in strong gravitational lensing with Gauss-Bonnet correction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Man, Jingyun; Cheng, Hongbo, E-mail: jingyunman@mail.ecust.edu.cn, E-mail: hbcheng@ecust.edu.cn

2014-11-01

The time delay between two relativistic images in the strong gravitational lensing governed by Gauss-Bonnet gravity is studied. We make a complete analytical derivation of the expression of time delay in presence of Gauss-Bonnet coupling. With respect to Schwarzschild, the time delay decreases as a consequence of the shrinking of the photon sphere. As the coupling increases, the second term in the time delay expansion becomes more relevant. Thus time delay in strong limit encodes some new information about geometry in five-dimensional spacetime with Gauss-Bonnet correction.

Theoretical basis to measure the impact of short-lasting control of an infectious disease on the epidemic peak

PubMed Central

2011-01-01

Background While many pandemic preparedness plans have promoted disease control effort to lower and delay an epidemic peak, analytical methods for determining the required control effort and making statistical inferences have yet to be sought. As a first step to address this issue, we present a theoretical basis on which to assess the impact of an early intervention on the epidemic peak, employing a simple epidemic model. Methods We focus on estimating the impact of an early control effort (e.g. unsuccessful containment), assuming that the transmission rate abruptly increases when control is discontinued. We provide analytical expressions for magnitude and time of the epidemic peak, employing approximate logistic and logarithmic-form solutions for the latter. Empirical influenza data (H1N1-2009) in Japan are analyzed to estimate the effect of the summer holiday period in lowering and delaying the peak in 2009. Results Our model estimates that the epidemic peak of the 2009 pandemic was delayed for 21 days due to summer holiday. Decline in peak appears to be a nonlinear function of control-associated reduction in the reproduction number. Peak delay is shown to critically depend on the fraction of initially immune individuals. Conclusions The proposed modeling approaches offer methodological avenues to assess empirical data and to objectively estimate required control effort to lower and delay an epidemic peak. Analytical findings support a critical need to conduct population-wide serological survey as a prior requirement for estimating the time of peak. PMID:21269441

In-water recompression.

PubMed

Doolette, David J; Mitchell, Simon J

2018-06-30

Divers suspected of suffering decompression illness (DCI) in locations remote from a recompression chamber are sometimes treated with in-water recompression (IWR). There are no data that establish the benefits of IWR compared to conventional first aid with surface oxygen and transport to the nearest chamber. However, the theoretical benefit of IWR is that it can be initiated with a very short delay to recompression after onset of manifestations of DCI. Retrospective analyses of the effect on outcome of increasing delay generally do not capture this very short delay achievable with IWR. However, in military training and experimental diving, delay to recompression is typically less than two hours and more than 90% of cases have complete resolution of manifestations during the first treatment, often within minutes of recompression. A major risk of IWR is that of an oxygen convulsion resulting in drowning. As a result, typical IWR oxygen-breathing protocols use shallower maximum depths (9 metres' sea water (msw), 191 kPa) and are shorter (1-3 hours) than standard recompression protocols for the initial treatment of DCI (e.g., US Navy Treatment Tables 5 and 6). There has been no experimentation with initial treatment of DCI at pressures less than 285 kPa since the original development of these treatment tables, when no differences in outcomes were seen between maximum pressures of 203 kPa (10 msw) and 285 kPa (18 msw) or deeper. These data and case series suggest that recompression treatment comprising pressures and durations similar to IWR protocols can be effective. The risk of IWR is not justified for treatment of mild symptoms likely to resolve spontaneously or for divers so functionally compromised that they would not be safe in the water. However, IWR conducted by properly trained and equipped divers may be justified for manifestations that are life or limb threatening where timely recompression is unavailable. Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

Facility-based constraints to exchange transfusions for neonatal hyperbilirubinemia in resource-limited settings

PubMed Central

Mabogunje, Cecilia A; Olaifa, Sarah M; Olusanya, Bolajoko O

2016-01-01

Several clinical guidelines for the management of infants with severe neonatal hyperbilirubinemia recommend immediate exchange transfusion (ET) when the risk or presence of acute bilirubin encephalopathy is established in order to prevent chronic bilirubin encephalopathy or kernicterus. However, the literature is sparse concerning the interval between the time the decision for ET is made and the actual initiation of ET, especially in low- and middle-income countries (LMICs) with significant resource constraints but high rates of ET. This paper explores the various stages and potential delays during this interval in complying with the requirement for immediate ET for the affected infants, based on the available evidence from LMICs. The vital role of intensive phototherapy, efficient laboratory and logistical support, and clinical expertise for ET are highlighted. The challenges in securing informed parental consent, especially on religious grounds, and meeting the financial burden of this emergency procedure to facilitate timely ET are examined. Secondary delays arising from post-treatment bilirubin rebound with intensive phototherapy or ET are also discussed. These potential delays can compromise the effectiveness of ET and should provide additional impetus to curtail avoidable ET in LMICs. PMID:27170928

Permanganate gel (PG) for groundwater remediation: compatibility, gelation, and release characteristics.

PubMed

Lee, Eung Seok; Olson, Pamela R; Gupta, Neha; Solpuker, Utku; Schwartz, Franklin W; Kim, Yongje

2014-02-01

Permanganate (MnO4(-)) is a strong oxidant that is widely used for treating chlorinated ethylenes in groundwater. This study aims to develop hyper-saline MnO4(-) solution (MnO4(-) gel; PG) that can be injected into aquifers via wells, slowly gelates over time, and slowly release MnO4(-) to flowing water. In this study, compatibility and miscibility of gels, such as chitosan, aluminosilicate, silicate, and colloidal silica gels, with MnO4(-) were tested. Of these gels, chitosan was reactive with MnO4(-). Aluminosilicates were compatible but not readily miscible with MnO4(-). Silicates and colloidal silica were both compatible and miscible with MnO4(-), and gelated with addition of KMnO4 granules. Colloidal silica has low initial viscosity (<15cP), exhibited delayed gelation characteristics with the lag times ranging from 0 to 200min. Release of MnO4(-) from the colloidal silica-based PG gel occurred in a delayed fashion, with maximum duration of 24h. These results suggested that colloidal silica can be used to create PG or delayed-gelling forms containing other oxidants which can be used for groundwater remediation. Copyright © 2013 Elsevier Ltd. All rights reserved.