Outcomes of extended oral contraceptive regimens with a shortened hormone-free interval to manage breakthrough bleeding.

PubMed

Sulak, Patricia J; Carl, Jenny; Gopalakrishnan, Isai; Coffee, Andrea; Kuehl, Thomas J

2004-10-01

To evaluate in a clinical practice setting the acceptance, continuation and variability of extending the active interval of oral contraceptives (OCs) with introduction of a shortened hormone-free interval (HFI) to manage breakthrough bleeding. A retrospective review was undertaken of patients seen by one obstetrician/gynecologist and counseled on extending the active interval of OCs with a shortened HFI of 3-4 days to manage bleeding. Electronic medical records were searched for the phrase "extending the number of active pills" for patients counseled between January 1, 2000, and January 31, 2003, with follow-up through January 31, 2004. A structured query of each patient's initial and follow-up records was performed. The 220 patients counseled on the extended regimen were 14-52 years of age (mean 36.4, SD 9.3 years). At initial counseling before extending, the majority of patients cited more than one reason for using OCs in the standard fashion with 59% using OCs for noncontraceptive reasons. Reasons for extending the active interval of OCs included premenstrual symptoms (45%), dysmenorrhea/pelvic pain (40%), heavy withdrawal bleeding (36%), menstrual associated headaches (35%), convenience (13%), acne associated with menses (10%) and other (15%). Of the 181 patients with follow-up data, 174 (96%) attempted an extended regimen with 121 (67%) continuing to do so at last follow-up. Follow-up intervals ranged from 0.3 to 3.8 years (mean 1.6 years). Using Kaplan-Meier product limit survival analysis, 60% of patients continued using extended patterns of OCs for more than 2 years. For 121 currently extending, the HFI varied from 0 to 7 days with 88% utilizing a 0 to 4 day HFI. Sixty percent of patients offered extending the active interval and shortening the HFI of OCs initiate and continue this pattern for more than 2 years without serious sequelae or pregnancy while individually directing both the number of days of continuous pills and the length of the HFI. Copyright 2004 Elsevier Inc.

Extended time-interval analysis

NASA Astrophysics Data System (ADS)

Fynbo, H. O. U.; Riisager, K.

2014-01-01

Several extensions of the halflife analysis method recently suggested by Horvat and Hardy are put forward. Goodness-of-fit testing is included, and the method is extended to cases where more information is available for each decay event which allows applications also for e.g. γ decay data. The results are tested with Monte Carlo simulations and are applied to the decays of 64Cu and 56Mn.

Launching lunar missions from Space Station Freedom

NASA Technical Reports Server (NTRS)

Friedlander, Alan; Young, Archie

1990-01-01

The relative orbital motion of Space Station Freedom and the moon places practical constraints on the timing of launch/return transfer trajectories. This paper describes the timing characteristics as well as the Delta-V variations over a representative cycle of launch/return opportunities. On average, the minimum-Delta-V transfer opportunities occur at intervals of 9 days. However, there is a significant nonuniform variation in this timing interval, as well as the minimum stay time at the moon, over the short cycle (51 days) and the long cycle (18.6 years). The advantage of three-impulse transfers for extending the launch window is also described.

Online evolution reconstruction from a single measurement record with random time intervals for quantum communication

NASA Astrophysics Data System (ADS)

Zhou, Hua; Su, Yang; Wang, Rong; Zhu, Yong; Shen, Huiping; Pu, Tao; Wu, Chuanxin; Zhao, Jiyong; Zhang, Baofu; Xu, Zhiyong

2017-10-01

Online reconstruction of a time-variant quantum state from the encoding/decoding results of quantum communication is addressed by developing a method of evolution reconstruction from a single measurement record with random time intervals. A time-variant two-dimensional state is reconstructed on the basis of recovering its expectation value functions of three nonorthogonal projectors from a random single measurement record, which is composed from the discarded qubits of the six-state protocol. The simulated results prove that our method is robust to typical metro quantum channels. Our work extends the Fourier-based method of evolution reconstruction from the version for a regular single measurement record with equal time intervals to a unified one, which can be applied to arbitrary single measurement records. The proposed protocol of evolution reconstruction runs concurrently with the one of quantum communication, which can facilitate the online quantum tomography.

Generalized Riemann hypothesis and stochastic time series

NASA Astrophysics Data System (ADS)

Mussardo, Giuseppe; LeClair, André

2018-06-01

Using the Dirichlet theorem on the equidistribution of residue classes modulo q and the Lemke Oliver–Soundararajan conjecture on the distribution of pairs of residues on consecutive primes, we show that the domain of convergence of the infinite product of Dirichlet L-functions of non-principal characters can be extended from down to , without encountering any zeros before reaching this critical line. The possibility of doing so can be traced back to a universal diffusive random walk behavior of a series C N over the primes which underlies the convergence of the infinite product of the Dirichlet functions. The series C N presents several aspects in common with stochastic time series and its control requires to address a problem similar to the single Brownian trajectory problem in statistical mechanics. In the case of the Dirichlet functions of non principal characters, we show that this problem can be solved in terms of a self-averaging procedure based on an ensemble of block variables computed on extended intervals of primes. Those intervals, called inertial intervals, ensure the ergodicity and stationarity of the time series underlying the quantity C N . The infinity of primes also ensures the absence of rare events which would have been responsible for a different scaling behavior than the universal law of the random walks.

Post-Correlation Semi-Coherent Integration for High-Dynamic and Weak GPS Signal Acquisition (Preprint)

DTIC Science & Technology

2008-06-01

provide the coverage. To enable weak GPS signal acquisition , one known technique at the receiver end is to extend the signal integration time...Han, “Block Accumulating Coherent Integration Over Extended Interval (BACIX) for Weak GPS Signal Acquisition ,” Proc. of ION-GNSS’06, Ft. Worth, TX...AFRL-RY-WP-TP-2008-1158 POST-CORRELATION SEMI-COHERENT INTEGRATION FOR HIGH-DYNAMIC AND WEAK GPS SIGNAL ACQUISITION (PREPRINT) Chun Yang

Extended International Normalized Ratio testing intervals for warfarin-treated patients.

PubMed

Barnes, G D; Kong, X; Cole, D; Haymart, B; Kline-Rogers, E; Almany, S; Dahu, M; Ekola, M; Kaatz, S; Kozlowski, J; Froehlich, J B

2018-05-15

Essentials Warfarin typically requires International Normalized Ratio (INR) testing at least every 4 weeks. We implemented extended INR testing for stable warfarin patients in six anticoagulation clinics. Use of extended INR testing increased from 41.8% to 69.3% over the 3 year study. Use of extended INR testing appeared safe and effective. Background A previous single-center randomized trial suggested that patients with stable International Normalized Ratio (INR) values could safely receive INR testing as infrequently as every 12 weeks. Objective To test the success of implementation of an extended INR testing interval for stable warfarin patients in a practice-based, multicenter collaborative of anticoagulation clinics. Methods At six anticoagulation clinics, patients were identified as being eligible for extended INR testing on the basis of prior INR value stability and minimal warfarin dose changes between 2014 and 2016. We assessed the frequency with which anticoagulation clinic providers recommended an extended INR testing interval (> 5 weeks) to eligible patients. We also explored safety outcomes for eligible patients, including next INR values, bleeding events, and emergency department visits. Results At least one eligible period for extended INR testing was identified in 890 of 3362 (26.5%) warfarin-treated patients. Overall, the use of extended INR testing in eligible patients increased from 41.8% in the first quarter of 2014 to 69.3% in the fourth quarter of 2016. The number of subsequent out-of-range next INR values were similar between eligible patients who did and did not have an extended INR testing interval (27.3% versus 28.4%, respectively). The numbers of major bleeding events were not different between the two groups, but rates of clinically relevant non-major bleeding (0.02 per 100 patient-years versus 0.09 per 100 patient-years) and emergency department visits (0.07 per 100 patient-years versus 0.19 per 100 patient-years) were lower for eligible patients with extended INR testing intervals than for those with non-extended INR testing intervals. Conclusions Extended INR testing for stable warfarin patients can be successfully and safely implemented in diverse, practice-based anticoagulation clinic settings. © 2018 International Society on Thrombosis and Haemostasis.

Chaotic orbits obeying one isolating integral in a four-dimensional map

NASA Astrophysics Data System (ADS)

Muzzio, J. C.

2018-02-01

We have recently presented strong evidence that chaotic orbits that obey one isolating integral besides energy exist in a toy Hamiltonian model with three degrees of freedom and are bounded by regular orbits that isolate them from the Arnold web. The interval covered by those numerical experiments was equivalent to about one million Hubble times in a galactic context. Here, we use a four-dimensional map to confirm our previous results and to extend that interval 50 times. We show that, at least within that interval, features found in lower dimension Hamiltonian systems and maps are also present in our study, e.g. within the phase space occupied by a chaotic orbit that obeys one integral there are subspaces where that orbit does not enter and are, instead, occupied by regular orbits that, if tori, bound other chaotic orbits obeying one integral and, if cantori, produce stickiness. We argue that the validity of our results might exceed the time intervals covered by the numerical experiments.

Is walking a random walk? Evidence for long-range correlations in stride interval of human gait

NASA Technical Reports Server (NTRS)

Hausdorff, Jeffrey M.; Peng, C.-K.; Ladin, Zvi; Wei, Jeanne Y.; Goldberger, Ary L.

1995-01-01

Complex fluctuation of unknown origin appear in the normal gait pattern. These fluctuations might be described as being (1) uncorrelated white noise, (2) short-range correlations, or (3) long-range correlations with power-law scaling. To test these possibilities, the stride interval of 10 healthy young men was measured as they walked for 9 min at their usual rate. From these time series we calculated scaling indexes by using a modified random walk analysis and power spectral analysis. Both indexes indicated the presence of long-range self-similar correlations extending over hundreds of steps; the stride interval at any time depended on the stride interval at remote previous times, and this dependence decayed in a scale-free (fractallike) power-law fashion. These scaling indexes were significantly different from those obtained after random shuffling of the original time series, indicating the importance of the sequential ordering of the stride interval. We demonstrate that conventional models of gait generation fail to reproduce the observed scaling behavior and introduce a new type of central pattern generator model that sucessfully accounts for the experimentally observed long-range correlations.

A Further Assessment of Momentary Time-Sampling across Extended Interval Lengths

ERIC Educational Resources Information Center

Alvero, Alicia M.; Rappaport, Eva; Taylor, Matthew A.

2011-01-01

The current study compared the estimation of momentary time-sampling (MTS) to actual safety performance of three ergonomic responses: back, shoulder, and feet. Actual safety performance was established for the five participants by measuring the target responses with a continuous procedure. MTS 90, 105, 120, 135, 150, 165, 180, 195, 210, 240, and…

Academic Delay of Gratification and Children's Study Time Allocation as a Function of Proximity to Consequential Academic Goals

ERIC Educational Resources Information Center

Zhang, Lili; Karabenick, Stuart A.; Maruno, Shun'ichi; Lauermann, Fani

2011-01-01

Students (N=302) in Chinese elementary schools were assessed regarding their academic delay of gratification (ADOG) and reported the time they devoted to non-school study and playtime during an extended interval prior to taking a high-stakes final exam. Students high compared those low in ADOG were more likely to spend time studying and less time…

Hospital factors impact variation in emergency department length of stay more than physician factors.

PubMed

Krall, Scott P; Cornelius, Angela P; Addison, J Bruce

2014-03-01

To analyze the correlation between the many different emergency department (ED) treatment metric intervals and determine if the metrics directly impacted by the physician correlate to the "door to room" interval in an ED (interval determined by ED bed availability). Our null hypothesis was that the cause of the variation in delay to receiving a room was multifactorial and does not correlate to any one metric interval. We collected daily interval averages from the ED information system, Meditech©. Patient flow metrics were collected on a 24-hour basis. We analyzed the relationship between the time intervals that make up an ED visit and the "arrival to room" interval using simple correlation (Pearson Correlation coefficients). Summary statistics of industry standard metrics were also done by dividing the intervals into 2 groups, based on the average ED length of stay (LOS) from the National Hospital Ambulatory Medical Care Survey: 2008 Emergency Department Summary. Simple correlation analysis showed that the doctor-to-discharge time interval had no correlation to the interval of "door to room (waiting room time)", correlation coefficient (CC) (CC=0.000, p=0.96). "Room to doctor" had a low correlation to "door to room" CC=0.143, while "decision to admitted patients departing the ED time" had a moderate correlation of 0.29 (p <0.001). "New arrivals" (daily patient census) had a strong correlation to longer "door to room" times, 0.657, p<0.001. The "door to discharge" times had a very strong correlation CC=0.804 (p<0.001), to the extended "door to room" time. Physician-dependent intervals had minimal correlation to the variation in arrival to room time. The "door to room" interval was a significant component to the variation in "door to discharge" i.e. LOS. The hospital-influenced "admit decision to hospital bed" i.e. hospital inpatient capacity, interval had a correlation to delayed "door to room" time. The other major factor affecting department bed availability was the "total patients per day." The correlation to the increasing "door to room" time also reflects the effect of availability of ED resources (beds) on the patient evaluation time. The time that it took for a patient to receive a room appeared more dependent on the system resources, for example, beds in the ED, as well as in the hospital, than on the physician.

MESOSCOPIC MODELING OF STOCHASTIC REACTION-DIFFUSION KINETICS IN THE SUBDIFFUSIVE REGIME

PubMed Central

BLANC, EMILIE; ENGBLOM, STEFAN; HELLANDER, ANDREAS; LÖTSTEDT, PER

2017-01-01

Subdiffusion has been proposed as an explanation of various kinetic phenomena inside living cells. In order to fascilitate large-scale computational studies of subdiffusive chemical processes, we extend a recently suggested mesoscopic model of subdiffusion into an accurate and consistent reaction-subdiffusion computational framework. Two different possible models of chemical reaction are revealed and some basic dynamic properties are derived. In certain cases those mesoscopic models have a direct interpretation at the macroscopic level as fractional partial differential equations in a bounded time interval. Through analysis and numerical experiments we estimate the macroscopic effects of reactions under subdiffusive mixing. The models display properties observed also in experiments: for a short time interval the behavior of the diffusion and the reaction is ordinary, in an intermediate interval the behavior is anomalous, and at long times the behavior is ordinary again. PMID:29046618

How should forensic anthropologists correct national weather service temperature data for use in estimating the postmortem interval?

PubMed

Dabbs, Gretchen R

2015-05-01

This study examines the correlation between site-specific and retrospectively collected temperature data from the National Weather Service (NWS) over an extended time period. Using iButtonLink thermochrons (model DS1921G), hourly temperature readings were collected at 15 sites (1 validation; 14 experimental) from December 2010 to January 2012. Comparison between the site-specific temperature data and data retrieved from an official reporter of NWS temperature data shows statistically significant differences between the two in 71.4% (10/14) of cases. The difference ranged between 0.04 and 2.81°C. Examination of both regression and simple adjustment of the mean difference over extended periods (1, 2, 3, 4, 5, 6, & 9 months) suggests that on the timescale typical in forensic anthropology cases neither method of correction is consistent or reliable and that forensic anthropologists would be better suited using uncorrected NWS temperature data when the postmortem interval is extended. © 2015 American Academy of Forensic Sciences.

Electronic Ambient-Temperature Recorder

NASA Technical Reports Server (NTRS)

Russell, Larry; Barrows, William

1995-01-01

Electronic temperature-recording unit stores data in internal memory for later readout. Records temperatures from minus 40 degrees to plus 60 degrees C at intervals ranging from 1.875 to 15 minutes. With all four data channels operating at 1.875-minute intervals, recorder stores at least 10 days' data. For only one channel at 15-minute intervals, capacity extends to up to 342 days' data. Developed for recording temperatures of instruments and life-science experiments on satellites, space shuttle, and high-altitude aircraft. Adaptable to such terrestrial uses as recording temperatures of perishable goods during transportation and of other systems or processes over long times. Can be placed directly in environment to monitor.

Preschool Children's Control of Action Outcomes

ERIC Educational Resources Information Center

Freier, Livia; Cooper, Richard P.; Mareschal, Denis

2017-01-01

Naturalistic goal-directed behaviours require the engagement and maintenance of appropriate levels of cognitive control over relatively extended intervals of time. In two experiments, we examined preschool children's abilities to maintain top-down control throughout the course of a sequential task. Both 3- and 5-year-olds demonstrated good…

Thermotemporal dynamics of contaminant bacteria and antimicrobials in extended porcine semen.

PubMed

Althouse, G C; Pierdon, M S; Lu, K G

2008-11-01

Bacterial contamination of extended porcine semen has been associated with deleterious effects on both semen quality and sow fertility. Retrospective, prospective and in vitro studies were performed to delineate the prevalence and behavior of certain bacterial contaminants in extended semen, and antimicrobial pharmacodynamics in various semen diluents. Retrospective review of extended semen samples submitted from North American boar studs for microbiological screening at the University of Pennsylvania Reference Andrology Laboratory in 2005 and 2006 yielded bacteriospermia prevalence rates of 17% (144/832) and 26% (256/984), respectively. In a prospective study of regional boar studs, of 91 extended semen samples tested over 1-y, 29% were positive for bacteriospermia. Retrospective and prospective studies both showed that the preponderance of contaminant positive samples occurred during the fall months (P<0.05). To better understand behavior of select contaminant bacteria, generation intervals were determined for Serratia marcescens (SM) and Achromobacter xylosoxidans (AX) at 16, 22 and 37 degrees C. Generation times were temperature-dependent, with intervals decreasing two- to four-fold as incubation temperature increased. Growth patterns for SM, AX and Burkholderia cepacia were evaluated in various semen diluents. The different diluents exhibited constant or episodic patterns of growth within and among bacteria throughout the 5-d test period. Kill-time kinetics at 37 degrees C of several genera of bacteria in four semen diluents containing amoxicillin, gentamicin, tylosin, and lincomycin/spectinomycin (single drug or combination) ranged from 75 to over 360min, and was highly dependent (P<0.05) upon both type of bacteria and semen diluent.

Time perception and reproduction in young adults with attention deficit hyperactivity disorder.

PubMed

Barkley, R A; Murphy, K R; Bush, T

2001-07-01

Adults with attention deficit hyperactivity disorder (ADHD; n = 104) were compared with a control group (n = 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than did the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors.

Modeling stream fish distributions using interval-censored detection times.

PubMed

Ferreira, Mário; Filipe, Ana Filipa; Bardos, David C; Magalhães, Maria Filomena; Beja, Pedro

2016-08-01

Controlling for imperfect detection is important for developing species distribution models (SDMs). Occupancy-detection models based on the time needed to detect a species can be used to address this problem, but this is hindered when times to detection are not known precisely. Here, we extend the time-to-detection model to deal with detections recorded in time intervals and illustrate the method using a case study on stream fish distribution modeling. We collected electrofishing samples of six fish species across a Mediterranean watershed in Northeast Portugal. Based on a Bayesian hierarchical framework, we modeled the probability of water presence in stream channels, and the probability of species occupancy conditional on water presence, in relation to environmental and spatial variables. We also modeled time-to-first detection conditional on occupancy in relation to local factors, using modified interval-censored exponential survival models. Posterior distributions of occupancy probabilities derived from the models were used to produce species distribution maps. Simulations indicated that the modified time-to-detection model provided unbiased parameter estimates despite interval-censoring. There was a tendency for spatial variation in detection rates to be primarily influenced by depth and, to a lesser extent, stream width. Species occupancies were consistently affected by stream order, elevation, and annual precipitation. Bayesian P-values and AUCs indicated that all models had adequate fit and high discrimination ability, respectively. Mapping of predicted occupancy probabilities showed widespread distribution by most species, but uncertainty was generally higher in tributaries and upper reaches. The interval-censored time-to-detection model provides a practical solution to model occupancy-detection when detections are recorded in time intervals. This modeling framework is useful for developing SDMs while controlling for variation in detection rates, as it uses simple data that can be readily collected by field ecologists.

78 FR 782 - Energy Northwest; Columbia Generating Station; Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-04

... health or safety, and are consistent with the common defense and security; and (2) when special... temporary relief from the applicable regulation and the licensee or applicant has made good faith efforts to... Common Defense and Security The proposed exemption would extend the time interval between the 2011 and...

Rule-Based Runtime Verification

NASA Technical Reports Server (NTRS)

Barringer, Howard; Goldberg, Allen; Havelund, Klaus; Sen, Koushik

2003-01-01

We present a rule-based framework for defining and implementing finite trace monitoring logics, including future and past time temporal logic, extended regular expressions, real-time logics, interval logics, forms of quantified temporal logics, and so on. Our logic, EAGLE, is implemented as a Java library and involves novel techniques for rule definition, manipulation and execution. Monitoring is done on a state-by-state basis, without storing the execution trace.

Pharmacokinetic-based prediction of real-life dosing of extended half-life clotting factor concentrates on hemophilia

PubMed Central

Gherardini, Stefano

2018-01-01

The improvement of clotting factor concentrates (CFCs) has undergone an impressive boost during the last six years. Since 2010, several new recombinant factor (rF)VIII/IX concentrates entered phase I/II/III clinical trials. The improvements are related to the culture of human embryonic kidney (HEK) cells, post-translational glycosylation, PEGylation, and co-expression of the fragment crystallizable (Fc) region of immunoglobulin (Ig)G1 or albumin genes in the manufacturing procedures. The extended half-life (EHL) CFCs allow an increase of the interval between bolus administrations during prophylaxis, a very important advantage for patients with difficulties in venous access. Although the inhibitor risk has not been fully established, phase III studies have provided standard prophylaxis protocols, which, compared with on-demand treatment, have achieved very low annualized bleeding rates (ABRs). The key pharmacokinetics (PK) parameter to tailor patient therapy is clearance, which is more reliable than the half-life of CFCs; the clearance considers the decay rate of the drug concentration–time profile, while the half-life considers only the half concentration of the drug at a given time. To tailor the prophylaxis of hemophilia patients in real-life, we propose two formulae (expressed in terms of the clearance, trough and dose interval between prophylaxis), respectively based on the one- and two-compartmental models (CMs), for the prediction of the optimal single dose of EHL CFCs. Once the data from the time decay of the CFCs are fitted by the one- or two-CMs after an individual PK analysis, such formulae provide to the treater the optimal trade-off among trough and time-intervals between boluses. In this way, a sufficiently long time-interval between bolus administration could be guaranteed for a wider class of patients, with a preassigned level of the trough. Finally, a PK approach using repeated dosing is discussed, and some examples with new EHL CFCs are shown. PMID:29899890

18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals derived from a single-institution 18F-FDG-directed surgery experience: feasibility and quantification of 18F-FDG accumulation within 18F-FDG-avid lesions and background tissues

PubMed Central

2014-01-01

Background 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is a well-established imaging modality for a wide variety of solid malignancies. Currently, only limited data exists regarding the utility of PET/CT imaging at very extended injection-to-scan acquisition times. The current retrospective data analysis assessed the feasibility and quantification of diagnostic 18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals. Methods 18F-FDG-avid lesions (not surgically manipulated or altered during 18F-FDG-directed surgery, and visualized both on preoperative and postoperative 18F-FDG PET/CT imaging) and corresponding background tissues were assessed for 18F-FDG accumulation on same-day preoperative and postoperative 18F-FDG PET/CT imaging. Multiple patient variables and 18F-FDG-avid lesion variables were examined. Results For the 32 18F-FDG-avid lesions making up the final 18F-FDG-avid lesion data set (from among 7 patients), the mean injection-to-scan times of the preoperative and postoperative 18F-FDG PET/CT scans were 73 (±3, 70-78) and 530 (±79, 413-739) minutes, respectively (P < 0.001). The preoperative and postoperative mean 18F-FDG-avid lesion SUVmax values were 7.7 (±4.0, 3.6-19.5) and 11.3 (±6.0, 4.1-29.2), respectively (P < 0.001). The preoperative and postoperative mean background SUVmax values were 2.3 (±0.6, 1.0-3.2) and 2.1 (±0.6, 1.0-3.3), respectively (P = 0.017). The preoperative and postoperative mean lesion-to-background SUVmax ratios were 3.7 (±2.3, 1.5-9.8) and 5.8 (±3.6, 1.6-16.2), respectively, (P < 0.001). Conclusions 18F-FDG PET/CT oncologic imaging can be successfully performed at extended injection-to-scan acquisition time intervals of up to approximately 5 half-lives for 18F-FDG while maintaining good/adequate diagnostic image quality. The resultant increase in the 18F-FDG-avid lesion SUVmax values, decreased background SUVmax values, and increased lesion-to-background SUVmax ratios seen from preoperative to postoperative 18F-FDG PET/CT imaging have great potential for allowing for the integrated, real-time use of 18F-FDG PET/CT imaging in conjunction with 18F-FDG-directed interventional radiology biopsy and ablation procedures and 18F-FDG-directed surgical procedures, as well as have far-reaching impact on potentially re-shaping future thinking regarding the “most optimal” injection-to-scan acquisition time interval for all routine diagnostic 18F-FDG PET/CT oncologic imaging. PMID:24942656

By-pass filters : taking your fleet the extra mile

DOT National Transportation Integrated Search

2000-01-01

There has been an industry-wide push over the last few years to extend oil drain intervals on fleet equipment. This industry demand is an effort to reduce downtime, reduce waste oil generation, and cut maintenance costs. Extended oil drain intervals ...

Variable selection in a flexible parametric mixture cure model with interval-censored data.

PubMed

Scolas, Sylvie; El Ghouch, Anouar; Legrand, Catherine; Oulhaj, Abderrahim

2016-03-30

In standard survival analysis, it is generally assumed that every individual will experience someday the event of interest. However, this is not always the case, as some individuals may not be susceptible to this event. Also, in medical studies, it is frequent that patients come to scheduled interviews and that the time to the event is only known to occur between two visits. That is, the data are interval-censored with a cure fraction. Variable selection in such a setting is of outstanding interest. Covariates impacting the survival are not necessarily the same as those impacting the probability to experience the event. The objective of this paper is to develop a parametric but flexible statistical model to analyze data that are interval-censored and include a fraction of cured individuals when the number of potential covariates may be large. We use the parametric mixture cure model with an accelerated failure time regression model for the survival, along with the extended generalized gamma for the error term. To overcome the issue of non-stable and non-continuous variable selection procedures, we extend the adaptive LASSO to our model. By means of simulation studies, we show good performance of our method and discuss the behavior of estimates with varying cure and censoring proportion. Lastly, our proposed method is illustrated with a real dataset studying the time until conversion to mild cognitive impairment, a possible precursor of Alzheimer's disease. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Robust stability of interval bidirectional associative memory neural network with time delays.

PubMed

Liao, Xiaofeng; Wong, Kwok-wo

2004-04-01

In this paper, the conventional bidirectional associative memory (BAM) neural network with signal transmission delay is intervalized in order to study the bounded effect of deviations in network parameters and external perturbations. The resultant model is referred to as a novel interval dynamic BAM (IDBAM) model. By combining a number of different Lyapunov functionals with the Razumikhin technique, some sufficient conditions for the existence of unique equilibrium and robust stability are derived. These results are fairly general and can be verified easily. To go further, we extend our investigation to the time-varying delay case. Some robust stability criteria for BAM with perturbations of time-varying delays are derived. Besides, our approach for the analysis allows us to consider several different types of activation functions, including piecewise linear sigmoids with bounded activations as well as the usual C1-smooth sigmoids. We believe that the results obtained have leading significance in the design and application of BAM neural networks.

EAGLE can do Efficient LTL Monitoring

NASA Technical Reports Server (NTRS)

Barringer, Howard; Goldberg, Allen; Havelund, Klaus; Sen, Koushik

2003-01-01

We briefly present a rule-based framework, called EAGLE, that has been shown to be capable of defining and implementing finite trace monitoring logics, including future and past time temporal logic, extended regular expressions, real-time logics, interval logics, forms of quantified temporal logics, and so on. In this paper we show how EAGLE can do linear temporal logic (LTL) monitoring in an efficient way. We give an upper bound on the space and time complexity of this monitoring.

Methylphenidate bioavailability in adults when an extended-release multiparticulate formulation is administered sprinkled on food or as an intact capsule.

PubMed

Pentikis, Helen S; Simmons, Roy D; Benedict, Michael F; Hatch, Simon J

2002-04-01

To determine the single-dose bioavailability of 20-mg Metadate CD (methylphenidate HCI, USP) Extended-Release Capsules sprinkled onto 1 level tablespoon (15 mL) of applesauce relative to an intact capsule under fasted conditions in healthy adults. This was a single-center, open-label, single-dose, randomized, two-way crossover study with a 6-day washout period between doses, in healthy male and female subjects (N= 26), aged 21-40 years. Plasma concentration-time data for methylphenidate were used to calculate the pharmacokinetic parameters for each treatment. The pharmacokinetic profile for Metadate CD exhibited biphasic release characteristics with a sharp initial slope and a second rising portion. For Cmax (maximum observed concentration), AUC(0-infinity) (area under the plasma concentration curve from time 0 to infinity) and AUC(0-infinity) (area under the plasma concentration curve from time 0 to the last measurable time point), the geometric least squares mean ratios and 90% confidence intervals were within the 80% to 125% confidence interval for bioequivalence. Adverse events were similar to those reported for methylphenidate. The bioavailability of methylphenidate was not altered when Metadate CD capsules were administered by sprinkling their contents onto a small amount of applesauce.

Pharmacokinetics and Safety of High-Dose and Extended-Interval Regimens of Levofloxacin in Human Immunodeficiency Virus-Infected Patients

PubMed Central

Piscitelli, Stephen C.; Spooner, Katherine; Baird, Barbara; Chow, Andrew T.; Fowler, Cynthia L.; Williams, Rex R.; Natarajan, Jaya; Masur, Henry; Walker, Robert E.

1999-01-01

The pharmacokinetics of levofloxacin, administered in high doses and with extended dosing intervals, was studied in human immunodeficiency virus (HIV)-infected patients. Thirty patients received either 750 mg of the drug or a placebo once daily for 14 days, followed by 750 mg or 1,000 mg of the drug or a placebo three times weekly for an additional 14 days. Levofloxacin disposition was characterized by rapid oral absorption, with peak concentrations occurring approximately 1.5 h after dosing and elimination half-lives from 7.2 to 9.4 h. The overall incidence of any adverse effect was 70% (1,000 mg) to 95% (750 mg) for levofloxacin-treated patients and 71% for those taking the placebo. Levofloxacin pharmacokinetic parameters for HIV-infected patients were consistent with those observed in studies of healthy volunteers. PMID:10471591

A high-order time-accurate interrogation method for time-resolved PIV

NASA Astrophysics Data System (ADS)

Lynch, Kyle; Scarano, Fulvio

2013-03-01

A novel method is introduced for increasing the accuracy and extending the dynamic range of time-resolved particle image velocimetry (PIV). The approach extends the concept of particle tracking velocimetry by multiple frames to the pattern tracking by cross-correlation analysis as employed in PIV. The working principle is based on tracking the patterned fluid element, within a chosen interrogation window, along its individual trajectory throughout an image sequence. In contrast to image-pair interrogation methods, the fluid trajectory correlation concept deals with variable velocity along curved trajectories and non-zero tangential acceleration during the observed time interval. As a result, the velocity magnitude and its direction are allowed to evolve in a nonlinear fashion along the fluid element trajectory. The continuum deformation (namely spatial derivatives of the velocity vector) is accounted for by adopting local image deformation. The principle offers important reductions of the measurement error based on three main points: by enlarging the temporal measurement interval, the relative error becomes reduced; secondly, the random and peak-locking errors are reduced by the use of least-squares polynomial fits to individual trajectories; finally, the introduction of high-order (nonlinear) fitting functions provides the basis for reducing the truncation error. Lastly, the instantaneous velocity is evaluated as the temporal derivative of the polynomial representation of the fluid parcel position in time. The principal features of this algorithm are compared with a single-pair iterative image deformation method. Synthetic image sequences are considered with steady flow (translation, shear and rotation) illustrating the increase of measurement precision. An experimental data set obtained by time-resolved PIV measurements of a circular jet is used to verify the robustness of the method on image sequences affected by camera noise and three-dimensional motions. In both cases, it is demonstrated that the measurement time interval can be significantly extended without compromising the correlation signal-to-noise ratio and with no increase of the truncation error. The increase of velocity dynamic range scales more than linearly with the number of frames included for the analysis, which supersedes by one order of magnitude the pair correlation by window deformation. The main factors influencing the performance of the method are discussed, namely the number of images composing the sequence and the polynomial order chosen to represent the motion throughout the trajectory.

The impact of children's internalizing and externalizing problems on parenting: Transactional processes and reciprocal change over time.

PubMed

Serbin, Lisa A; Kingdon, Danielle; Ruttle, Paula L; Stack, Dale M

2015-11-01

Most theoretical models of developmental psychopathology involve a transactional, bidirectional relation between parenting and children's behavior problems. The present study utilized a cross-lagged panel, multiple interval design to model change in bidirectional relations between child and parent behavior across successive developmental periods. Two major categories of child behavior problems, internalizing and externalizing, and two aspects of parenting, positive (use of support and structure) and harsh discipline (use of physical punishment), were modeled across three time points spaced 3 years apart. Two successive developmental intervals, from approximately age 7.5 to 10.5 and from 10.5 to 13.5, were included. Mother-child dyads (N = 138; 65 boys) from a lower income longitudinal sample of families participated, with standardized measures of mothers rating their own parenting behavior and teachers reporting on child's behavior. Results revealed different types of reciprocal relations between specific aspects of child and parent behavior, with internalizing problems predicting an increase in positive parenting over time, which subsequently led to a reduction in internalizing problems across the successive 3-year interval. In contrast, externalizing predicted reduced levels of positive parenting in a reciprocal sequence that extended across two successive intervals and predicted increased levels of externalizing over time. Implications for prevention and early intervention are discussed.

Extending the time interval for applying herbicide in cut-stump treatments on American beech

Treesearch

Jeffrey D. Kochenderfer; James N. Kochenderfer; Gary W. Miller

2013-01-01

American Beech (Fagus grandifolia Ehrh.) root sprouts often form dense understories that interfere with tree reproduction throughout much of the eastern hardwood region. The cut-stump treatment, whereby herbicide is applied to the stump within a few hours after a larger beech is felled, has been shown to mitigate the interference problem by...

Consideration of computer limitations in implementing on-line controls. M.S. Thesis

NASA Technical Reports Server (NTRS)

Roberts, G. K.

1976-01-01

A formal statement of the optimal control problem which includes the interval of dicretization as an optimization parameter, and extend this to include selection of a control algorithm as part of the optimization procedure, is formulated. The performance of the scalar linear system depends on the discretization interval. Discrete-time versions of the output feedback regulator and an optimal compensator, and the use of these results in presenting an example of a system for which fast partial-state-feedback control better minimizes a quadratic cost than either a full-state feedback control or a compensator, are developed.

On Reformulating Planning as Dynamic Constraint Satisfaction

NASA Technical Reports Server (NTRS)

Frank, Jeremy; Jonsson, Ari K.; Morris, Paul; Koga, Dennis (Technical Monitor)

2000-01-01

In recent years, researchers have reformulated STRIPS planning problems as SAT problems or CSPs. In this paper, we discuss the Constraint-Based Interval Planning (CBIP) paradigm, which can represent planning problems incorporating interval time and resources. We describe how to reformulate mutual exclusion constraints for a CBIP-based system, the Extendible Uniform Remote Operations Planner Architecture (EUROPA). We show that reformulations involving dynamic variable domains restrict the algorithms which can be used to solve the resulting DCSP. We present an alternative formulation which does not employ dynamic domains, and describe the relative merits of the different reformulations.

The contribution of disengagement to temporal discriminability.

PubMed

Shipstead, Zach; Nespodzany, Ashley

2018-05-01

The present study examines the idea that time-based forgetting of outdated information can lead to better memory of currently relevant information. This was done using the visual arrays task, along with a between-subjects manipulation of both the retention interval (1 s vs. 4 s) and the time between two trials (1 s vs. 4 s). Consistent with prior work [Shipstead, Z., & Engle, R. W. (2013). Interference within the focus of attention: Working memory tasks reflect more than temporary maintenance. Journal of Experimental Psychology: Learning, Memory, and Cognition, 39, 277-289; Experiment 1], longer retention intervals did not lead to diminished memory of currently relevant information. However, we did find that longer periods of time between two trials improved memory for currently relevant information. This replicates findings that indicate proactive interference affects visual arrays performance and extends previous findings to show that reduction of proactive interference can occur in a time-dependent manner.

Random walks of colloidal probes in viscoelastic materials

NASA Astrophysics Data System (ADS)

Khan, Manas; Mason, Thomas G.

2014-04-01

To overcome limitations of using a single fixed time step in random walk simulations, such as those that rely on the classic Wiener approach, we have developed an algorithm for exploring random walks based on random temporal steps that are uniformly distributed in logarithmic time. This improvement enables us to generate random-walk trajectories of probe particles that span a highly extended dynamic range in time, thereby facilitating the exploration of probe motion in soft viscoelastic materials. By combining this faster approach with a Maxwell-Voigt model (MVM) of linear viscoelasticity, based on a slowly diffusing harmonically bound Brownian particle, we rapidly create trajectories of spherical probes in soft viscoelastic materials over more than 12 orders of magnitude in time. Appropriate windowing of these trajectories over different time intervals demonstrates that random walk for the MVM is neither self-similar nor self-affine, even if the viscoelastic material is isotropic. We extend this approach to spatially anisotropic viscoelastic materials, using binning to calculate the anisotropic mean square displacements and creep compliances along different orthogonal directions. The elimination of a fixed time step in simulations of random processes, including random walks, opens up interesting possibilities for modeling dynamics and response over a highly extended temporal dynamic range.

Laser pulse stretcher method and apparatus

DOEpatents

Hawkins, Jon K.; Williams, William A.

1990-01-01

The output of an oscillator stage of a laser system is monitored by a photocell which is coupled to a feedback section to control a Pockels Cell and change the light output of the oscillator stage. A synchronizing pulse is generated in timed relation to the initiation of operation of the oscillator stage and is applied to a forward feed section which cooperates with the feedback section to maintain the light output constant for an extended time interval.

31 CFR 342.3 - Extended terms and yields for outstanding notes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Extended terms and yields for... SAVINGS NOTES § 342.3 Extended terms and yields for outstanding notes. (a) Extended maturity periods. The terms extended maturity period and second extended maturity period refer to the 10-year intervals after...

31 CFR 342.3 - Extended terms and yields for outstanding notes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Extended terms and yields for... SAVINGS NOTES § 342.3 Extended terms and yields for outstanding notes. (a) Extended maturity periods. The terms extended maturity period and second extended maturity period refer to the 10-year intervals after...

31 CFR 342.3 - Extended terms and yields for outstanding notes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Extended terms and yields for... SAVINGS NOTES § 342.3 Extended terms and yields for outstanding notes. (a) Extended maturity periods. The terms extended maturity period and second extended maturity period refer to the 10-year intervals after...

31 CFR 342.3 - Extended terms and yields for outstanding notes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 2 2013-07-01 2013-07-01 false Extended terms and yields for... SAVINGS NOTES § 342.3 Extended terms and yields for outstanding notes. (a) Extended maturity periods. The terms extended maturity period and second extended maturity period refer to the 10-year intervals after...

31 CFR 342.3 - Extended terms and yields for outstanding notes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 2 2012-07-01 2012-07-01 false Extended terms and yields for... SAVINGS NOTES § 342.3 Extended terms and yields for outstanding notes. (a) Extended maturity periods. The terms extended maturity period and second extended maturity period refer to the 10-year intervals after...

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

Zhang, J.; Feng, W., E-mail: fengwen69@sina.cn

Extended time series of Solar Activity Indices (ESAI) extended the Greenwich series of sunspot area from the year 1874 back to 1821. The ESAI's yearly sunspot area in the northern and southern hemispheres from 1821 to 2013 is utilized to investigate characteristics of the north–south hemispherical asymmetry of sunspot activity. Periodical behavior of about 12 solar cycles is also confirmed from the ESAI data set to exist in dominant hemispheres, linear regression lines of yearly asymmetry values, and cumulative counts of yearly sunspot areas in the hemispheres for solar cycles. The period is also inferred to appear in both themore » cumulative difference in the yearly sunspot areas in the hemispheres over the entire time interval and in its statistical Student's t-test. The hemispherical bias of sunspot activity should be regarded as an impossible stochastic phenomenon over a long time period.« less

Modified dwell time optimization model and its applications in subaperture polishing.

PubMed

Dong, Zhichao; Cheng, Haobo; Tam, Hon-Yuen

2014-05-20

The optimization of dwell time is an important procedure in deterministic subaperture polishing. We present a modified optimization model of dwell time by iterative and numerical method, assisted by extended surface forms and tool paths for suppressing the edge effect. Compared with discrete convolution and linear equation models, the proposed model has essential compatibility with arbitrary tool paths, multiple tool influence functions (TIFs) in one optimization, and asymmetric TIFs. The emulational fabrication of a Φ200  mm workpiece by the proposed model yields a smooth, continuous, and non-negative dwell time map with a root-mean-square (RMS) convergence rate of 99.6%, and the optimization costs much less time. By the proposed model, influences of TIF size and path interval to convergence rate and polishing time are optimized, respectively, for typical low and middle spatial-frequency errors. Results show that (1) the TIF size is nonlinear inversely proportional to convergence rate and polishing time. A TIF size of ~1/7 workpiece size is preferred; (2) the polishing time is less sensitive to path interval, but increasing the interval markedly reduces the convergence rate. A path interval of ~1/8-1/10 of the TIF size is deemed to be appropriate. The proposed model is deployed on a JR-1800 and MRF-180 machine. Figuring results of Φ920  mm Zerodur paraboloid and Φ100  mm Zerodur plane by them yield RMS of 0.016λ and 0.013λ (λ=632.8  nm), respectively, and thereby validate the feasibility of proposed dwell time model used for subaperture polishing.

NUMERICAL METHODS FOR SOLVING THE MULTI-TERM TIME-FRACTIONAL WAVE-DIFFUSION EQUATION.

PubMed

Liu, F; Meerschaert, M M; McGough, R J; Zhuang, P; Liu, Q

2013-03-01

In this paper, the multi-term time-fractional wave-diffusion equations are considered. The multi-term time fractional derivatives are defined in the Caputo sense, whose orders belong to the intervals [0,1], [1,2), [0,2), [0,3), [2,3) and [2,4), respectively. Some computationally effective numerical methods are proposed for simulating the multi-term time-fractional wave-diffusion equations. The numerical results demonstrate the effectiveness of theoretical analysis. These methods and techniques can also be extended to other kinds of the multi-term fractional time-space models with fractional Laplacian.

NUMERICAL METHODS FOR SOLVING THE MULTI-TERM TIME-FRACTIONAL WAVE-DIFFUSION EQUATION

PubMed Central

Liu, F.; Meerschaert, M.M.; McGough, R.J.; Zhuang, P.; Liu, Q.

2013-01-01

In this paper, the multi-term time-fractional wave-diffusion equations are considered. The multi-term time fractional derivatives are defined in the Caputo sense, whose orders belong to the intervals [0,1], [1,2), [0,2), [0,3), [2,3) and [2,4), respectively. Some computationally effective numerical methods are proposed for simulating the multi-term time-fractional wave-diffusion equations. The numerical results demonstrate the effectiveness of theoretical analysis. These methods and techniques can also be extended to other kinds of the multi-term fractional time-space models with fractional Laplacian. PMID:23772179

75 FR 78588 - Airworthiness Directives; The Boeing Company Model 777-200, -300, and -300ER Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-16

... (ATA), on behalf of its member Delta Air Lines Inc. (Delta), asked that the 60-month compliance time in the supplemental NPRM be extended to better align with industry standard tank entry intervals. Delta stated that the required modifications will require entry into the main and center fuel tanks, and Delta...

Adherence patterns to extended cervical screening intervals in women undergoing human papillomavirus (HPV) and cytology cotesting.

PubMed

Rendle, Katharine A; Schiffman, Mark; Cheung, Li C; Kinney, Walter K; Fetterman, Barbara; Poitras, Nancy E; Lorey, Thomas; Castle, Philip E

2018-04-01

Although guidelines have recommended extended interval cervical screening using concurrent human papillomavirus (HPV) and cytology ("cotesting") for over a decade, little is known about its adoption into routine care. Using longitudinal medical record data (2003-2015) from Kaiser Permanente Northern California (KPNC), which adopted triennial cotesting in 2003, we examined adherence to extended interval screening. We analyzed predictors of screening intervals among 491,588 women undergoing routine screening, categorizing interval length into early (<2.5years), adherent (2.5<3.5years), or late (3.5<6.0years). We also examined repeated early screening in a subgroup of 50,691 women. Predictors examined included: cohort year (defined by baseline cotest, 2003-2009), race/ethnicity, and baseline age. Compared to the 2003 cohort, women in the 2009 cohort were significantly less likely to screen early (aOR=0.22, 95% CI=0.21, 0.23) or late (aOR=0.47, 95% CI=0.45, 0.49). African American (AA) and Hispanic women were less adherent overall than Non-Hispanic White women, with increased early [(AA: aOR=1.21, 95%CI=1.17, 1.25) (Hispanic: aOR=1.08, 95%CI=1.06, 1.11)] and late screening [(AA: aOR=1.23, 95%CI=1.19, 1.27) (Hispanic: aOR=1.06, 95%CI=1.03, 1.08)]. Asian women were slightly more likely to screen early (aOR=1.03, 95%CI=1.01, 1.05), and less likely to screen late (aOR=0.92, 95% CI=0.90, 0.94). Women aged 60-64years were most likely to screen early for two consecutive intervals (aOR=2.09, 95%CI=1.91, 2.29). Our study found that widespread and rapid adoption of extended interval cervical cancer screening is possible, at least in this managed care setting. Further research examining multilevel drivers promoting or restricting extended interval screening across diverse healthcare settings is needed. Copyright © 2018 Elsevier Inc. All rights reserved.

RXTE and BeppoSAX Observations of the Transient X-ray Pulsar XTE J 18591+083

NASA Technical Reports Server (NTRS)

Corbet, R. H. D.; intZand, J. J. M.; Levine, A. M.; Marshall, F. E.

2008-01-01

We present observations of the 9.8 s X-ray pulsar XTE J159+083 made with the All-Sky Monitor (ASM) and Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer (RXTE), and the Wide Field Cameras (WFC) on board BeppoSAX. The ASM data cover a 12 year time interval and show that an extended outburst occurred between approximately MJD50, 250, and 50, 460 (1996 June 16 to 1997 January 12). The ASM data excluding this outburst interval suggest a possible 61 day modulation. Eighteen sets of PCA observations were obtained over an approx. one month interval in 1999. The flux variability measured with the PCA appears consistent with the possible period found with the ASM. The PCA measurements of the pulse period showed it to decrease non-monotonically and then to increase significantly. Doppler shifts due to orbital motion rather than accretion torques appear to be better able to explain the pulse period changes. Observations with the WFC during the extended outburst give an error box which is consistent with a previously determined PCA error box but is significantly smaller. The transient nature of XTE J1859+083 and the length of its pulse period are consistent with it being a Be/neutral star binary. The possible 61 day orbital period would be of the expected length for a Be star system with a 9.8 s pulse period.

On cell resistance and immune response time lag in a model for the HIV infection

NASA Astrophysics Data System (ADS)

Solovey, Guillermo; Peruani, Fernando; Ponce Dawson, Silvina; Maria Zorzenon dos Santos, Rita

2004-11-01

Recently, a cellular automata model has been introduced (Phys. Rev. Lett. 87 (2001) 168102) to describe the spread of the HIV infection among target cells in lymphoid tissues. The model reproduces qualitatively the entire course of the infection displaying, in particular, the two time scales that characterize its dynamics. In this work, we investigate the robustness of the model against changes in three of its parameters. Two of them are related to the resistance of the cells to get infected. The other one describes the time interval necessary to mount specific immune responses. We have observed that an increase of the cell resistance, at any stage of the infection, leads to a reduction of the latency period, i.e., of the time interval between the primary infection and the onset of AIDS. However, during the early stages of the infection, when the cell resistance increase is combined with an increase in the initial concentration of infected cells, the original behavior is recovered. Therefore we find a long and a short latency regime (eight and one year long, respectively) depending on the value of the cell resistance. We have obtained, on the other hand, that changes on the parameter that describes the immune system time lag affects the time interval during which the primary infection occurs. Using different extended versions of the model, we also discuss how the two-time scale dynamics is affected when we include inhomogeneities on the cells properties, as for instance, on the cell resistance or on the time interval to mount specific immune responses.

The relationship between defecation and feeding in nestling birds: observational and experimental evidence.

PubMed

Quan, Rui-Chang; Li, Huan; Wang, Bo; Goodale, Eben

2015-01-01

Adult birds clean the nest by consuming or transporting feces, which is thought to be important in order to lower the levels of parasites, pathogens and predation at the nest. If nestlings were to defecate when parents were absent, however, feces could accumulate in the nest. To understand the mechanism by which nest sanitation is maintained, we studied the timing of defecation in nestling birds of common passerine species in southwest China. In 159 nests of 8 species at the nestling stage during 779 randomly timed observations, we never found fecal sacs present. Video recordings, totaling 455 h at five Pycnonotus jocosus nests in the field, showed almost all defecation after feedings, and only nestlings that were fed defecated. Six translocated P. jocosus nests were taken into captivity in order to manipulate the frequency of feeding. These nestlings defecated only after feeding, even when feeding intervals were extended to 60 and 120 min. The fecal sac weight also increased with extended feeding intervals, demonstrating a remarkable plasticity for nestlings to wait for feedings. The evidence allows two major conclusions: 1) defecation in the nest occurs at a time that ensures nest sanitation, stimulated by feeding, rather than there being a set time of gut processing between feeding and excretion; 2) the strong plasticity in the timing of defecation and the possibility of negative repercussions (if defecation occurs when parents are absent) are important mechanisms underlying the efficiency of the feeding-defecation system.

Spatial memory during the tropism of maize (Zea mays L.) coleoptiles.

PubMed

Nick, P; Schafer, E

1988-09-01

Photo- or gravitropic stimulation of graminean coleoptiles involves the formation of putative tropistic transverse polarities. It had been postulated that these polarities can be extended by stabilization to developmentally active polarities. Such polarities are known from unicellular spores and zygotes of lower plants and regeneration experiments in dicotyledonous plants. In coleoptiles, photo- or gravitropic stimulation results in stability to counterstimulation of equal strength (with only transient bending in the direction of the second stimulus), as a result of a directional memory, if the time interval between both stimuli exceeds 90 min. This directional memory develops from a labile precursor, which is present from at least 20 min after induction. Once it is stable, spatial memory is conserved for many hours. The formation of spatial memory involves at least one step not present in the common tropistic transduction chain. The spatial expression of memory as curvature is restricted to three distinct responses: (i) curving in the direction of the first stimulus (for time intervals exceeding 90 min); (ii) curving in the direction of the second stimulus (for time intervals shorter than 65 min); and (iii) zero-curvature (for time intervals between 65 and 90 min). This can be interpreted in terms of a stable transverse polarity, which is not identical with the putative tropistic transverse polarity, but might be an extension of it.

Differences between measured and linearly interpolated synoptic variables over a 12-h period during AVE 4

NASA Technical Reports Server (NTRS)

Dupuis, L. R.; Scoggins, J. R.

1979-01-01

Results of analyses revealed that nonlinear changes or differences formed centers or systems, that were mesosynoptic in nature. These systems correlated well in space with upper level short waves, frontal zones, and radar observed convection, and were very systematic in time and space. Many of the centers of differences were well established in the vertical, extending up to the tropopause. Statistical analysis showed that on the average nonlinear changes were larger in convective areas than nonconvective regions. Errors often exceeding 100 percent were made by assuming variables to change linearly through a 12-h period in areas of thunderstorms, indicating that these nonlinear changes are important in the development of severe weather. Linear changes, however, accounted for more and more of an observed change as the time interval (within the 12-h interpolation period) increased, implying that the accuracy of linear interpolation increased over larger time intervals.

Further developments of the Neyman-Scott clustered point process for modeling rainfall

NASA Astrophysics Data System (ADS)

Cowpertwait, Paul S. P.

1991-07-01

This paper provides some useful results for modeling rainfall. It extends work on the Neyman-Scott cluster model for simulating rainfall time series. Several important properties have previously been found for the model, for example, the expectation and variance of the amount of rain captured in an arbitrary time interval (Rodriguez-Iturbe et al., 1987a), In this paper additional properties are derived, such as the probability of an arbitrary interval of any chosen length being dry. In applications this is a desirable property to have, and is often used for fitting stochastic rainfall models to field data. The model is currently being used in rainfall time series research directed toward improving sewage systems in the United Kingdom. To illustrate the model's performance an example is given, where the model is fitted to 10 years of hourly data taken from Blackpool, England.

Current Fluctuations in Stochastic Lattice Gases

NASA Astrophysics Data System (ADS)

Bertini, L.; de Sole, A.; Gabrielli, D.; Jona-Lasinio, G.; Landim, C.

2005-01-01

We study current fluctuations in lattice gases in the macroscopic limit extending the dynamic approach for density fluctuations developed in previous articles. More precisely, we establish a large deviation theory for the space-time fluctuations of the empirical current which include the previous results. We then estimate the probability of a fluctuation of the average current over a large time interval. It turns out that recent results by Bodineau and Derrida [Phys. Rev. Lett.922004180601] in certain cases underestimate this probability due to the occurrence of dynamical phase transitions.

Powerplexer

NASA Technical Reports Server (NTRS)

Woods, J. M. (Inventor)

1973-01-01

An electrical power distribution system is described for use in providing different dc voltage levels. A circuit is supplied with DC voltage levels and commutates pulses for timed intervals onto a pair of distribution wires. The circuit is driven by a command generator which places pulses on the wires in a timed sequence. The pair of wires extend to voltage strippers connected to the various loads. The voltage strippers each respond to the pulse dc levels on the pair of wires and form different output voltages communicated to each load.

Extended-hours hemodialysis is associated with lower mortality risk in patients with end-stage renal disease

PubMed Central

Rivara, Matthew B.; Adams, Scott V.; Kuttykrishnan, Sooraj; Kalantar-Zadeh, Kamyar; Arah, Onyebuchi A.; Cheung, Alfred K.; Katz, Ronit; Molnar, Miklos Z.; Ravel, Vanessa; Soohoo, Melissa; Streja, Elani; Himmelfarb, Jonathan; Mehrotra, Rajnish

2016-01-01

Extended-hours hemodialysis offers substantially longer treatment time compared to conventional hemodialysis schedules and is associated with improved fluid and electrolyte control and favorable cardiac remodeling. However, whether extended-hours hemodialysis improves survival remains unclear. Therefore, we determined the association between extended-hours compared to conventional hemodialysis and the risk of all-cause mortality in a nationally representative cohort of patients initiating maintenance dialysis in the United States from 2007 to 2011. Survival analyses using causal inference modeling with marginal structural models were performed to compare mortality risk among 1,206 individuals undergoing thrice weekly extended-hours hemodialysis or 111,707 patients receiving conventional hemodialysis treatments. The average treatment time per session for extended-hours hemodialysis was 399 minutes compared to 211 minutes for conventional therapy. The crude mortality rate with extended-hours hemodialysis was 6.4 deaths per 100 patient-years compared with 14.7 deaths per 100 patient-years for conventional hemodialysis. In the primary analysis, patients treated with extended-hours hemodialysis had a 33% lower adjusted risk of death compared to those who were treated with a conventional regimen (95% confidence interval: 7% to 51%). Additional analyses accounting for analytical assumptions regarding exposure and outcome, facility-level confounders, and prior modality history were similar. Thus, in this large nationally representative cohort, treatment with extended-hours hemodialysis was associated with a lower risk for mortality compared to treatment with conventional in-center therapy. Adequately powered randomized clinical trials comparing extended-hours to conventional hemodialysis are required to confirm these findings. PMID:27555118

Routine vs extended outpatient EEG for the detection of interictal epileptiform discharges

PubMed Central

Britton, Jeffrey W.; Rajasekaran, Vijayalakshmi; Fabris, Rachel R.; Cherian, Perumpillichira J.; Kelly-Williams, Kristen M.; So, Elson L.; Nickels, Katherine C.; Wong-Kisiel, Lily C.; Lagerlund, Terrence D.; Cascino, Gregory D.; Worrell, Gregory A.; Wirrell, Elaine C.

2016-01-01

Objective: To compare the yield of epileptiform abnormalities on 30-minute recordings with those greater than 45 minutes. Methods: We performed a prospective observational cross-sectional study of all outpatient routine EEGs comparing the rate of interictal epileptiform discharges (IEDs) and clinical events during the initial 30 minutes (routine) with those occurring in the remaining 30–60 minutes (extended). A relative increase of 10% was considered clinically significant. Results: EEGs from 1,803 patients were included; overall EEG duration was 59.4 minutes (SD ±6.5). Of 426 patients with IEDs at any time during the EEG, 81 (19.1%, 95% confidence interval 15.6–23) occurred only after the initial 30 minutes. The rate of late IEDs was not associated with age, indication, IED type, or sleep deprivation. Longer recording times also increased event capture rate by approximately 30%. Conclusions: The yield of IED and event detection is increased in extended outpatient EEGs compared to 30-minute studies. PMID:26984946

Routine vs extended outpatient EEG for the detection of interictal epileptiform discharges.

PubMed

Burkholder, David B; Britton, Jeffrey W; Rajasekaran, Vijayalakshmi; Fabris, Rachel R; Cherian, Perumpillichira J; Kelly-Williams, Kristen M; So, Elson L; Nickels, Katherine C; Wong-Kisiel, Lily C; Lagerlund, Terrence D; Cascino, Gregory D; Worrell, Gregory A; Wirrell, Elaine C

2016-04-19

To compare the yield of epileptiform abnormalities on 30-minute recordings with those greater than 45 minutes. We performed a prospective observational cross-sectional study of all outpatient routine EEGs comparing the rate of interictal epileptiform discharges (IEDs) and clinical events during the initial 30 minutes (routine) with those occurring in the remaining 30-60 minutes (extended). A relative increase of 10% was considered clinically significant. EEGs from 1,803 patients were included; overall EEG duration was 59.4 minutes (SD ±6.5). Of 426 patients with IEDs at any time during the EEG, 81 (19.1%, 95% confidence interval 15.6-23) occurred only after the initial 30 minutes. The rate of late IEDs was not associated with age, indication, IED type, or sleep deprivation. Longer recording times also increased event capture rate by approximately 30%. The yield of IED and event detection is increased in extended outpatient EEGs compared to 30-minute studies. © 2016 American Academy of Neurology.

One-year outcomes of a treat-and-extend regimen of intravitreal aflibercept for polypoidal choroidal vasculopathy.

PubMed

Hosokawa, Mio; Morizane, Yuki; Hirano, Masayuki; Kimura, Shuhei; Kumase, Fumiaki; Shiode, Yusuke; Doi, Shinichiro; Toshima, Shinji; Hosogi, Mika; Fujiwara, Atsushi; Mitsuhashi, Toshiharu; Shiraga, Fumio

2017-03-01

To evaluate the 1-year treatment outcomes of intravitreal aflibercept injections (IVA) using a treat-and-extend regimen for polypoidal choroidal vasculopathy (PCV). Thirty-seven eyes with treatment-naive PCV treated with IVA using a treat-and-extend regimen for 1 year were reviewed retrospectively. The main outcome measures were changes in the best-corrected visual acuity (BCVA) and central retinal thickness (CRT), and the treatment interval at 1 year. The predictive factors for patients who could not continue to extend the treatment interval because of poor response to IVA or recurrence were analyzed. The mean logarithm of the minimum angle of resolution BCVA improved from 0.37 at baseline to 0.21 at 1 year (P < 0.001). The mean CRT decreased from 342.3 μm at baseline to 196.6 μm at 1 year (P < 0.001). The mean treatment interval was 9.7 weeks at 1 year (4 weeks in 11 eyes [29.7%], 6 weeks in 1 eye [2.7%], 8 weeks in 2 eyes [5.4%], 10 weeks in 1 eye [2.7%], and 12 weeks in 22 eyes [59.5%]). A larger number of polypoidal lesions at baseline was predictive for patients who could not continue to extend the treatment interval. IVA using a treat-and-extend regimen is effective for improving BCVA and CRT in eyes with PCV.

Impulsive Effects on Quasi-Synchronization of Neural Networks With Parameter Mismatches and Time-Varying Delay.

PubMed

Tang, Ze; Park, Ju H; Feng, Jianwen

2018-04-01

This paper is concerned with the exponential synchronization issue of nonidentically coupled neural networks with time-varying delay. Due to the parameter mismatch phenomena existed in neural networks, the problem of quasi-synchronization is thus discussed by applying some impulsive control strategies. Based on the definition of average impulsive interval and the extended comparison principle for impulsive systems, some criteria for achieving the quasi-synchronization of neural networks are derived. More extensive ranges of impulsive effects are discussed so that impulse could either play an effective role or play an adverse role in the final network synchronization. In addition, according to the extended formula for the variation of parameters with time-varying delay, precisely exponential convergence rates and quasi-synchronization errors are obtained, respectively, in view of different types impulsive effects. Finally, some numerical simulations with different types of impulsive effects are presented to illustrate the effectiveness of theoretical analysis.

Cosinor-based rhythmometry

PubMed Central

2014-01-01

A brief overview is provided of cosinor-based techniques for the analysis of time series in chronobiology. Conceived as a regression problem, the method is applicable to non-equidistant data, a major advantage. Another dividend is the feasibility of deriving confidence intervals for parameters of rhythmic components of known periods, readily drawn from the least squares procedure, stressing the importance of prior (external) information. Originally developed for the analysis of short and sparse data series, the extended cosinor has been further developed for the analysis of long time series, focusing both on rhythm detection and parameter estimation. Attention is given to the assumptions underlying the use of the cosinor and ways to determine whether they are satisfied. In particular, ways of dealing with non-stationary data are presented. Examples illustrate the use of the different cosinor-based methods, extending their application from the study of circadian rhythms to the mapping of broad time structures (chronomes). PMID:24725531

Phylogenetic diversity measures based on Hill numbers.

PubMed

Chao, Anne; Chiu, Chun-Huo; Jost, Lou

2010-11-27

We propose a parametric class of phylogenetic diversity (PD) measures that are sensitive to both species abundance and species taxonomic or phylogenetic distances. This work extends the conventional parametric species-neutral approach (based on 'effective number of species' or Hill numbers) to take into account species relatedness, and also generalizes the traditional phylogenetic approach (based on 'total phylogenetic length') to incorporate species abundances. The proposed measure quantifies 'the mean effective number of species' over any time interval of interest, or the 'effective number of maximally distinct lineages' over that time interval. The product of the measure and the interval length quantifies the 'branch diversity' of the phylogenetic tree during that interval. The new measures generalize and unify many existing measures and lead to a natural definition of taxonomic diversity as a special case. The replication principle (or doubling property), an important requirement for species-neutral diversity, is generalized to PD. The widely used Rao's quadratic entropy and the phylogenetic entropy do not satisfy this essential property, but a simple transformation converts each to our measures, which do satisfy the property. The proposed approach is applied to forest data for interpreting the effects of thinning.

Emotion processing in the visual brain: a MEG analysis.

PubMed

Peyk, Peter; Schupp, Harald T; Elbert, Thomas; Junghöfer, Markus

2008-06-01

Recent functional magnetic resonance imaging (fMRI) and event-related brain potential (ERP) studies provide empirical support for the notion that emotional cues guide selective attention. Extending this line of research, whole head magneto-encephalogram (MEG) was measured while participants viewed in separate experimental blocks a continuous stream of either pleasant and neutral or unpleasant and neutral pictures, presented for 330 ms each. Event-related magnetic fields (ERF) were analyzed after intersubject sensor coregistration, complemented by minimum norm estimates (MNE) to explore neural generator sources. Both streams of analysis converge by demonstrating the selective emotion processing in an early (120-170 ms) and a late time interval (220-310 ms). ERF analysis revealed that the polarity of the emotion difference fields was reversed across early and late intervals suggesting distinct patterns of activation in the visual processing stream. Source analysis revealed the amplified processing of emotional pictures in visual processing areas with more pronounced occipito-parieto-temporal activation in the early time interval, and a stronger engagement of more anterior, temporal, regions in the later interval. Confirming previous ERP studies showing facilitated emotion processing, the present data suggest that MEG provides a complementary look at the spread of activation in the visual processing stream.

Sleep-dependent consolidation benefits fast transfer of time interval training.

PubMed

Chen, Lihan; Guo, Lu; Bao, Ming

2017-03-01

Previous study has shown that short training (15 min) for explicitly discriminating temporal intervals between two paired auditory beeps, or between two paired tactile taps, can significantly improve observers' ability to classify the perceptual states of visual Ternus apparent motion while the training of task-irrelevant sensory properties did not help to improve visual timing (Chen and Zhou in Exp Brain Res 232(6):1855-1864, 2014). The present study examined the role of 'consolidation' after training of temporal task-irrelevant properties, or whether a pure delay (i.e., blank consolidation) following pretest of the target task would give rise to improved ability of visual interval timing, typified in visual Ternus display. A procedure of pretest-training-posttest was adopted, with the probe of discriminating Ternus apparent motion. The extended implicit training of timing in which the time intervals between paired auditory beeps or paired tactile taps were manipulated but the task was discrimination of the auditory pitches or tactile intensities, did not lead to the training benefits (Exps 1 and 3); however, a delay of 24 h after implicit training of timing, including solving 'Sudoku puzzles,' made the otherwise absent training benefits observable (Exps 2, 4, 5 and 6). The above improvements in performance were not due to a practice effect of Ternus motion (Exp 7). A general 'blank' consolidation period of 24 h also made improvements of visual timing observable (Exp 8). Taken together, the current findings indicated that sleep-dependent consolidation imposed a general effect, by potentially triggering and maintaining neuroplastic changes in the intrinsic (timing) network to enhance the ability of time perception.

Extended score interval in the assessment of basic surgical skills.

PubMed

Acosta, Stefan; Sevonius, Dan; Beckman, Anders

2015-01-01

The Basic Surgical Skills course uses an assessment score interval of 0-3. An extended score interval, 1-6, was proposed by the Swedish steering committee of the course. The aim of this study was to analyze the trainee scores in the current 0-3 scored version compared to a proposed 1-6 scored version. Sixteen participants, seven females and nine males, were evaluated in the current and proposed assessment forms by instructors, observers, and learners themselves during the first and second day. In each assessment form, 17 tasks were assessed. The inter-rater reliability between the current and the proposed score sheets were evaluated with intraclass correlation (ICC) with 95% confidence intervals (CI). The distribution of scores for 'knot tying' at the last time point and 'bowel anastomosis side to side' given by the instructors in the current assessment form showed that the highest score was given in 31 and 62%, respectively. No ceiling effects were found in the proposed assessment form. The overall ICC between the current and proposed score sheets after assessment by the instructors increased from 0.38 (95% CI 0.77-0.78) on Day 1 to 0.83 (95% CI 0.51-0.94) on Day 2. A clear ceiling effect of scores was demonstrated in the current assessment form, questioning its validity. The proposed score sheet provides more accurate scores and seems to be a better feedback instrument for learning technical surgical skills in the Basic Surgical Skills course.

Extended score interval in the assessment of basic surgical skills.

PubMed

Acosta, Stefan; Sevonius, Dan; Beckman, Anders

2015-01-01

Introduction The Basic Surgical Skills course uses an assessment score interval of 0-3. An extended score interval, 1-6, was proposed by the Swedish steering committee of the course. The aim of this study was to analyze the trainee scores in the current 0-3 scored version compared to a proposed 1-6 scored version. Methods Sixteen participants, seven females and nine males, were evaluated in the current and proposed assessment forms by instructors, observers, and learners themselves during the first and second day. In each assessment form, 17 tasks were assessed. The inter-rater reliability between the current and the proposed score sheets were evaluated with intraclass correlation (ICC) with 95% confidence intervals (CI). Results The distribution of scores for 'knot tying' at the last time point and 'bowel anastomosis side to side' given by the instructors in the current assessment form showed that the highest score was given in 31 and 62%, respectively. No ceiling effects were found in the proposed assessment form. The overall ICC between the current and proposed score sheets after assessment by the instructors increased from 0.38 (95% CI 0.77-0.78) on Day 1 to 0.83 (95% CI 0.51-0.94) on Day 2. Discussion A clear ceiling effect of scores was demonstrated in the current assessment form, questioning its validity. The proposed score sheet provides more accurate scores and seems to be a better feedback instrument for learning technical surgical skills in the Basic Surgical Skills course.

Intermittent Drug Dosing Intervals Guided by the Operational Multiple Dosing Half Lives for Predictable Plasma Accumulation and Fluctuation

PubMed Central

Grover, Anita; Benet, Leslie Z.

2013-01-01

Intermittent drug dosing intervals are usually initially guided by the terminal pharmacokinetic half life and are dependent on drug formulation. For chronic multiple dosing and for extended release dosage forms, the terminal half life often does not predict the plasma drug accumulation or fluctuation observed. We define and advance applications for the operational multiple dosing half lives for drug accumulation and fluctuation after multiple oral dosing at steady-state. Using Monte Carlo simulation, our results predict a way to maximize the operational multiple dosing half lives relative to the terminal half life by using a first-order absorption rate constant close to the terminal elimination rate constant in the design of extended release dosage forms. In this way, drugs that may be eliminated early in the development pipeline due to a relatively short half life can be formulated to be dosed at intervals three times the terminal half life, maximizing compliance, while maintaining tight plasma concentration accumulation and fluctuation ranges. We also present situations in which the operational multiple dosing half lives will be especially relevant in the determination of dosing intervals, including for drugs that follow a direct PKPD model and have a narrow therapeutic index, as the rate of concentration decrease after chronic multiple dosing (that is not the terminal half life) can be determined via simulation. These principles are illustrated with case studies on valproic acid, diazepam, and anti-hypertensives. PMID:21499748

Extended local similarity analysis (eLSA) of microbial community and other time series data with replicates.

PubMed

Xia, Li C; Steele, Joshua A; Cram, Jacob A; Cardon, Zoe G; Simmons, Sheri L; Vallino, Joseph J; Fuhrman, Jed A; Sun, Fengzhu

2011-01-01

The increasing availability of time series microbial community data from metagenomics and other molecular biological studies has enabled the analysis of large-scale microbial co-occurrence and association networks. Among the many analytical techniques available, the Local Similarity Analysis (LSA) method is unique in that it captures local and potentially time-delayed co-occurrence and association patterns in time series data that cannot otherwise be identified by ordinary correlation analysis. However LSA, as originally developed, does not consider time series data with replicates, which hinders the full exploitation of available information. With replicates, it is possible to understand the variability of local similarity (LS) score and to obtain its confidence interval. We extended our LSA technique to time series data with replicates and termed it extended LSA, or eLSA. Simulations showed the capability of eLSA to capture subinterval and time-delayed associations. We implemented the eLSA technique into an easy-to-use analytic software package. The software pipeline integrates data normalization, statistical correlation calculation, statistical significance evaluation, and association network construction steps. We applied the eLSA technique to microbial community and gene expression datasets, where unique time-dependent associations were identified. The extended LSA analysis technique was demonstrated to reveal statistically significant local and potentially time-delayed association patterns in replicated time series data beyond that of ordinary correlation analysis. These statistically significant associations can provide insights to the real dynamics of biological systems. The newly designed eLSA software efficiently streamlines the analysis and is freely available from the eLSA homepage, which can be accessed at http://meta.usc.edu/softs/lsa.

Extended local similarity analysis (eLSA) of microbial community and other time series data with replicates

PubMed Central

2011-01-01

Background The increasing availability of time series microbial community data from metagenomics and other molecular biological studies has enabled the analysis of large-scale microbial co-occurrence and association networks. Among the many analytical techniques available, the Local Similarity Analysis (LSA) method is unique in that it captures local and potentially time-delayed co-occurrence and association patterns in time series data that cannot otherwise be identified by ordinary correlation analysis. However LSA, as originally developed, does not consider time series data with replicates, which hinders the full exploitation of available information. With replicates, it is possible to understand the variability of local similarity (LS) score and to obtain its confidence interval. Results We extended our LSA technique to time series data with replicates and termed it extended LSA, or eLSA. Simulations showed the capability of eLSA to capture subinterval and time-delayed associations. We implemented the eLSA technique into an easy-to-use analytic software package. The software pipeline integrates data normalization, statistical correlation calculation, statistical significance evaluation, and association network construction steps. We applied the eLSA technique to microbial community and gene expression datasets, where unique time-dependent associations were identified. Conclusions The extended LSA analysis technique was demonstrated to reveal statistically significant local and potentially time-delayed association patterns in replicated time series data beyond that of ordinary correlation analysis. These statistically significant associations can provide insights to the real dynamics of biological systems. The newly designed eLSA software efficiently streamlines the analysis and is freely available from the eLSA homepage, which can be accessed at http://meta.usc.edu/softs/lsa. PMID:22784572

Multiple correlation analyses of metabolic and endocrine profiles with fertility in primiparous and multiparous cows.

PubMed

Wathes, D C; Bourne, N; Cheng, Z; Mann, G E; Taylor, V J; Coffey, M P

2007-03-01

Results from 4 studies were combined (representing a total of 500 lactations) to investigate the relationships between metabolic parameters and fertility in dairy cows. Information was collected on blood metabolic traits and body condition score at 1 to 2 wk prepartum and at 2, 4, and 7 wk postpartum. Fertility traits were days to commencement of luteal activity, days to first service, days to conception, and failure to conceive. Primiparous and multiparous cows were considered separately. Initial linear regression analyses were used to determine relationships among fertility, metabolic, and endocrine traits at each time point. All metabolic and endocrine traits significantly related to fertility were included in stepwise multiple regression analyses alone (model 1), including peak milk yield and interval to commencement of luteal activity (model 2), and with the further addition of dietary group (model 3). In multiparous cows, extended calving to conception intervals were associated prepartum with greater concentrations of leptin and lesser concentrations of nonesterified fatty acids and urea, and postpartum with reduced insulin-like growth factor-I at 2 wk, greater urea at 7 wk, and greater peak milk yield. In primiparous cows, extended calving to conception intervals were associated with more body condition and more urea prepartum, elevated urea postpartum, and more body condition loss by 7 wk. In conclusion, some metabolic measurements were associated with poorer fertility outcomes. Relationships between fertility and metabolic and endocrine traits varied both according to the lactation number of the cow and with the time relative to calving.

Depletion of mesospheric sodium during extended period of pulsating aurora

NASA Astrophysics Data System (ADS)

Takahashi, T.; Hosokawa, K.; Nozawa, S.; Tsuda, T. T.; Ogawa, Y.; Tsutsumi, M.; Hiraki, Y.; Fujiwara, H.; Kawahara, T. D.; Saito, N.; Wada, S.; Kawabata, T.; Hall, C.

2017-01-01

We quantitatively evaluated the Na density depletion due to charge transfer reactions between Na atoms and molecular ions produced by high-energy electron precipitation during a pulsating aurora (PsA). An extended period of PsA was captured by an all-sky camera at the European Incoherent Scatter (EISCAT) radar Tromsø site (69.6°N, 19.2°E) during a 2 h interval from 00:00 to 02:00 UT on 25 January 2012. During this period, using the EISCAT very high frequency (VHF) radar, we detected three intervals of intense ionization below 100 km that were probably caused by precipitation of high-energy electrons during the PsA. In these intervals, the sodium lidar at Tromsø observed characteristic depletion of Na density at altitudes between 97 and 100 km. These Na density depletions lasted for 8 min and represented 5-8% of the background Na layer. To examine the cause of this depletion, we modeled the depletion rate based on charge transfer reactions with NO+ and O2+ while changing the R value which is defined as the ratio of NO+ to O2+ densities, from 1 to 10. The correlation coefficients between observed and modeled Na density depletion calculated with typical value R = 3 for time intervals T1, T2, and T3 were 0.66, 0.80, and 0.67, respectively. The observed Na density depletion rates fall within the range of modeled depletion rate calculated with R from 1 to 10. This suggests that the charge transfer reactions triggered by the auroral impact ionization at low altitudes are the predominant process responsible for Na density depletion during PsA intervals.

Extended-hours hemodialysis is associated with lower mortality risk in patients with end-stage renal disease.

PubMed

Rivara, Matthew B; Adams, Scott V; Kuttykrishnan, Sooraj; Kalantar-Zadeh, Kamyar; Arah, Onyebuchi A; Cheung, Alfred K; Katz, Ronit; Molnar, Miklos Z; Ravel, Vanessa; Soohoo, Melissa; Streja, Elani; Himmelfarb, Jonathan; Mehrotra, Rajnish

2016-12-01

Extended-hours hemodialysis offers substantially longer treatment time compared to conventional hemodialysis schedules and is associated with improved fluid and electrolyte control and favorable cardiac remodeling. However, whether extended-hours hemodialysis improves survival remains unclear. Therefore, we determined the association between extended-hours compared to conventional hemodialysis and the risk of all-cause mortality in a nationally representative cohort of patients initiating maintenance dialysis in the United States from 2007 to 2011. Survival analyses using causal inference modeling with marginal structural models were performed to compare mortality risk among 1206 individuals undergoing thrice weekly extended-hours hemodialysis or 111,707 patients receiving conventional hemodialysis treatments. The average treatment time per session for extended-hours hemodialysis was 399 minutes compared to 211 minutes for conventional therapy. The crude mortality rate with extended-hours hemodialysis was 6.4 deaths per 100 patient-years compared with 14.7 deaths per 100 patient-years for conventional hemodialysis. In the primary analysis, patients treated with extended-hours hemodialysis had a 33% lower adjusted risk of death compared to those who were treated with a conventional regimen (95% confidence interval: 7% to 51%). Additional analyses accounting for analytical assumptions regarding exposure and outcome, facility-level confounders, and prior modality history were similar. Thus, in this large nationally representative cohort, treatment with extended-hours hemodialysis was associated with a lower risk for mortality compared to treatment with conventional in-center therapy. Adequately powered randomized clinical trials comparing extended-hours to conventional hemodialysis are required to confirm these findings. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Access Control to Information in Pervasive Computing Environments

DTIC Science & Technology

2005-08-01

for foo’s public key. (Digital signatures are omitted.) indicate a set of location and time intervals. A service will return location information only...stands for foo’s public key. (Digital signatures are omitted.) it describes the resource to which access is granted. Currently, we allow only resources...information relationship. Alice’s location information is bun- dled in her personal information. (The digital signature is omitted.) We use extended

An extended Kalman filter approach to non-stationary Bayesian estimation of reduced-order vocal fold model parameters.

PubMed

Hadwin, Paul J; Peterson, Sean D

2017-04-01

The Bayesian framework for parameter inference provides a basis from which subject-specific reduced-order vocal fold models can be generated. Previously, it has been shown that a particle filter technique is capable of producing estimates and associated credibility intervals of time-varying reduced-order vocal fold model parameters. However, the particle filter approach is difficult to implement and has a high computational cost, which can be barriers to clinical adoption. This work presents an alternative estimation strategy based upon Kalman filtering aimed at reducing the computational cost of subject-specific model development. The robustness of this approach to Gaussian and non-Gaussian noise is discussed. The extended Kalman filter (EKF) approach is found to perform very well in comparison with the particle filter technique at dramatically lower computational cost. Based upon the test cases explored, the EKF is comparable in terms of accuracy to the particle filter technique when greater than 6000 particles are employed; if less particles are employed, the EKF actually performs better. For comparable levels of accuracy, the solution time is reduced by 2 orders of magnitude when employing the EKF. By virtue of the approximations used in the EKF, however, the credibility intervals tend to be slightly underpredicted.

Pharmacokinetics of imipenem in critically ill patients during empirical treatment of nosocomial pneumonia: a comparison of 0.5-h and 3-h infusions.

PubMed

Lipš, Michal; Siller, Michal; Strojil, Jan; Urbánek, Karel; Balík, Martin; Suchánková, Hana

2014-10-01

In critically ill patients, pathophysiological changes alter the pharmacokinetics of antibiotics. Imipenem exhibits primarily time-dependent killing. Its administration by prolonged infusion may increase the time for which its plasma concentration exceeds the minimum inhibitory concentrations (MICs) of suspected pathogens. The objectives of this study were to compare the pharmacokinetic parameters of imipenem administered by standard short infusion (1g imipenem/1g cilastatin over 30min three times daily) and by extended infusion with a reduced total dose (0.5g imipenem/0.5g cilastatin over 3h four times daily) and to compare the target pharmacokinetic/pharmacodynamic indices, namely percentage of the dosing interval for which the free plasma concentration of imipenem exceeds the MIC and 4× MIC (%fT>MIC and %fT>4×MIC) of 0.5, 1, 2 and 4mg/L, for these two regimens in critically ill adult patients with nosocomial pneumonia on Day 2 of empirical antibiotic therapy. The study included 22 patients. Whilst no significant differences were found between both groups for %fT>MIC, %fT>4×MIC was 87.4±12.19%, 68.6±15.08%, 47.31±6.64% and 27.81±9.52% of the 8-h interval in the short infusion group for MICs of 0.5, 1, 2 and 4mg/L, respectively, and 85.15±17.57%, 53.14±27.27%, 13.55±24.47% and 0±0% of the 6-h interval for the extended infusion group. In conclusion, administration of 0.5g of imipenem by a 3-h infusion every 6h does not provide sufficient drug concentrations to treat infections caused by pathogens with a MIC of ≥2mg/L. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Surface Detail Reproduction and Dimensional Stability of Contemporary Irreversible Hydrocolloid Alternatives after Immediate and Delayed Pouring.

PubMed

Kusugal, Preethi; Chourasiya, Ritu Sunil; Ruttonji, Zarir; Astagi, Preeti; Nayak, Ajay Kumar; Patil, Abhishekha

2018-01-01

To overcome the poor dimensional stability of irreversible hydrocolloids, alternative materials were introduced. The dimensional changes of these alternatives after delayed pouring are not well studied and documented in the literature. The purpose of the study is to evaluate and compare the surface detail reproduction and dimensional stability of two irreversible hydrocolloid alternatives with an extended-pour irreversible hydrocolloid at different time intervals. All testing were performed according to the ANSI/ADA specification number 18 for surface detail reproduction and specification number 19 for dimensional change. The test materials used in this study were newer irreversible hydrocolloid alternatives such as AlgiNot FS, Algin-X Ultra FS, and Kromopan 100 which is an extended pour irreversible hydrocolloid as control. The surface detail reproduction was evaluated using stereomicroscope. The dimensional change after storage period of 1 h, 24 h, and 120 h was assessed and compared between the test materials and control. The data were analyzed using one-way ANOVA and post hoc Bonferroni test. Statistically significant results ( P < 0.001) were seen when mean scores of the tested materials were compared with respect to reproduction of 22 μm line from the metal block. Kromopan 100 showed statistically significant differences between different time intervals ( P < 0.001) and exhibited more dimensional change. Algin-X Ultra FS proved to be more accurate and dimensionally stable. Newer irreversible hydrocolloid alternative impression materials were more accurate in surface detail reproduction and exhibited minimal dimensional change after storage period of 1 h, 24 h, and 120 h than extended-pour irreversible hydrocolloid impression material.

Statistics of a neuron model driven by asymmetric colored noise.

PubMed

Müller-Hansen, Finn; Droste, Felix; Lindner, Benjamin

2015-02-01

Irregular firing of neurons can be modeled as a stochastic process. Here we study the perfect integrate-and-fire neuron driven by dichotomous noise, a Markovian process that jumps between two states (i.e., possesses a non-Gaussian statistics) and exhibits nonvanishing temporal correlations (i.e., represents a colored noise). Specifically, we consider asymmetric dichotomous noise with two different transition rates. Using a first-passage-time formulation, we derive exact expressions for the probability density and the serial correlation coefficient of the interspike interval (time interval between two subsequent neural action potentials) and the power spectrum of the spike train. Furthermore, we extend the model by including additional Gaussian white noise, and we give approximations for the interspike interval (ISI) statistics in this case. Numerical simulations are used to validate the exact analytical results for pure dichotomous noise, and to test the approximations of the ISI statistics when Gaussian white noise is included. The results may help to understand how correlations and asymmetry of noise and signals in nerve cells shape neuronal firing statistics.

Fluctuations in heart rate variability of health care workers during four consecutive extended work shifts and recovery during rest and sleep.

PubMed

Goffeng, Elisabeth M; Nordby, Karl-Christian; Tarvainen, Mika P; Järvelin-Pasanen, Susanna; Wagstaff, Anthony; Goffeng, Lars Ole; Bugge, Merete; Skare, Øivind; Sigstad Lie, Jenny-Anne

2018-04-07

The aim of this study was to investigate fluctuations in heart rate variability (HRV), which reflect autonomic nervous system (ANS) function and potential psychological and physical strain, among 24 health care workers during work and sleep during four consecutive extended work shifts. Data included 24/36/12 h of HRV measurements, two logbooks, and a questionnaire. A cross-shift/cross-week design was applied. HRV was measured during work, leisure time, and sleep. The HRV data included time-domain [mean RR, SD of normal to normal R-R intervals (SDNN), and root mean square of the successive differences (RMSSD)] and frequency-domain [low frequency (LF)/high frequency (HF) ratio] parameters. HRV parameters revealed significant differences among work, leisure time, and sleep. Mean RR, RMSSD, and SDNN values were lower and the LF/HF ratio was higher on the first versus last day of the work period; however, the differences were most prominent in the morning hours. The results indicate higher levels of cardiovascular stress on the first versus fourth day of the working period, and measurements at night indicate a satisfactory recovery from the extended shifts.

Prolongevity effects of a botanical with oregano and cranberry extracts in Mexican fruit flies: examining interactions of diet restriction and age.

PubMed

Zou, Sige; Carey, James R; Liedo, Pablo; Ingram, Donald K; Yu, Binbing

2012-04-01

Botanicals rich with phytochemicals have numerous health benefits. Dietary restriction (DR) extends lifespan in diverse species. We previously demonstrated that an oregano-cranberry (OC) mixture can promote longevity in the Mexican Fruit fly (Mexfly, Anastrepha ludens Loew). However, little is known about the interaction between botanicals and DR, and the age-dependent effect of botanicals on lifespan and reproduction. Here we investigated these issues by feeding Mexflies a full or DR diet supplemented with or without 2% OC. Lifespan and daily egg production of individual flies were recorded. The effect of short-term OC supplementation was evaluated by implementing the supplementation at three age intervals-young, middle, and old age. We found that OC increased lifespan of Mexflies on the full or DR diet when compared to their respective controls. OC increased reproduction of females on the full diet and, to a lesser extent, on the DR diet. Short-term OC supplementation was not sufficient to extend lifespan for males at all three age intervals nor for females at young and old age intervals. However, OC supplementation at the middle age interval was sufficient to extend lifespan in females, while only OC supplementation at the young age interval increased reproduction in females. Our findings suggest that OC extends lifespan and promotes reproduction partly through DR-independent pathways, and short-term supplementation have varied impact on longevity and reproduction. This also suggests a positive interaction between non-genetic interventions in promoting longevity and provides guidance for using botanicals as aging interventions in humans.

The steady part of the secular variation of the Earth's magnetic field

NASA Technical Reports Server (NTRS)

Bloxham, Jeremy

1992-01-01

The secular variation of the Earth's magnetic field results from the effects of magnetic induction in the fluid outer core and from the effects of magnetic diffusion in the core and the mantle. Adequate observations to map the magnetic field at the core-mantle boundary extend back over three centuries, providing a model of the secular variation at the core-mantle boundary. Here we consider how best to analyze this time-dependent part of the field. To calculate steady core flow over long time periods, we introduce an adaptation of our earlier method of calculating the flow in order to achieve greater numerical stability. We perform this procedure for the periods 1840-1990 and 1690-1840 and find that well over 90 percent of the variance of the time-dependent field can be explained by simple steady core flow. The core flows obtained for the two intervals are broadly similar to each other and to flows determined over much shorter recent intervals.

The general matching law describes choice on concurrent variable-interval schedules of wheel-running reinforcement.

PubMed

Belke, T W; Belliveau, J

2001-05-01

Six male Wistar rats were exposed to concurrent variable-interval schedules of wheel-running reinforcement. The reinforcer associated with each alternative was the opportunity to run for 15 s, and the duration of the changeover delay was 1 s. Results suggested that time allocation was more sensitive to relative reinforcement rate than was response allocation. For time allocation, the mean slopes and intercepts were 0.82 and 0.008, respectively. In contrast, for response allocation, mean slopes and intercepts were 0.60 and 0.03, respectively. Correction for low response rates and high rates of changing over, however, increased slopes for response allocation to about equal those for time allocation. The results of the present study suggest that the two-operant form of the matching law can be extended to wheel-running reinforcement. 'I'he effects of a low overall response rate, a short Changeover delay, and long postreinforcement pausing on the assessment of matching in the present study are discussed.

Two Billion Years of Magmatism in One Place on Mars

NASA Astrophysics Data System (ADS)

Taylor, G. J.

2017-05-01

Thomas Lapen and Minako Righter (University of Houston), and colleagues at Aarhus University (Denmark), the Universities of Washington (Seattle), Wisconsin (Madison), California (Berkeley), and Arizona (Tucson), and Purdue University (Indiana) show that a geochemically-related group of Martian meteorites formed over a much longer time span than thought previously. So-called depleted shergottites formed during the time interval 325 to 600 million years ago, but now age dating on a recently discovered Martian meteorite, Northwest Africa (NWA) 7635, extends that interval by 1800 million years to 2400 million years. NWA 7635 and almost all other depleted shergottites were ejected from Mars in the same impact event, as defined by their same cosmic-ray exposure age of 1 million years, so all resided in one small area on Mars. This long time span of volcanic activity in the same place on the planet indicates that magma production was continuous, consistent with geophysical calculations of magma generation in plumes of hot mantle rising from the core-mantle boundary deep inside Mars.

An extended model of the Barkhausen effect based on the ABBM model

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

Clatterbuck, D. M.; Garcia, V. J.; Johnson, M. J.

2000-05-01

The Barkhausen model of Alessandro et al. [J. Appl. Phys. 68, 2901 (1990)] has been extended to nonstationary domain wall dynamics. The assumptions of the original model limit, its use to situations where the differential permeability, and time derivative of applied field are constant. The later model of Jiles et al. assumes that the Barkhausen activity in a given time interval is proportional to the rate of change of irreversible magnetization which can be calculated from hysteresis models. The extended model presented here incorporates ideas from both of these. It assumes that the pinning field and domain wall velocity behavemore » according to the Alessandro model, but allows the rate of change of the magnetic flux to vary around a moving average which is determined by the shape of the hysteresis curve and the applied magnetic field wave form. As a result, the new model allows for changes in permeability with applied field and can also reproduce the frequency response of experimental Barkhausen signals. (c) 2000 American Institute of Physics.« less

Development and interval testing of a naturalistic driving methodology to evaluate driving behavior in clinical research.

PubMed

Babulal, Ganesh M; Addison, Aaron; Ghoshal, Nupur; Stout, Sarah H; Vernon, Elizabeth K; Sellan, Mark; Roe, Catherine M

2016-01-01

Background : The number of older adults in the United States will double by 2056. Additionally, the number of licensed drivers will increase along with extended driving-life expectancy. Motor vehicle crashes are a leading cause of injury and death in older adults. Alzheimer's disease (AD) also negatively impacts driving ability and increases crash risk. Conventional methods to evaluate driving ability are limited in predicting decline among older adults. Innovations in GPS hardware and software can monitor driving behavior in the actual environments people drive in. Commercial off-the-shelf (COTS) devices are affordable, easy to install and capture large volumes of data in real-time. However, adapting these methodologies for research can be challenging. This study sought to adapt a COTS device and determine an interval that produced accurate data on the actual route driven for use in future studies involving older adults with and without AD.  Methods : Three subjects drove a single course in different vehicles at different intervals (30, 60 and 120 seconds), at different times of day, morning (9:00-11:59AM), afternoon (2:00-5:00PM) and night (7:00-10pm). The nine datasets were examined to determine the optimal collection interval. Results : Compared to the 120-second and 60-second intervals, the 30-second interval was optimal in capturing the actual route driven along with the lowest number of incorrect paths and affordability weighing considerations for data storage and curation. Discussion : Use of COTS devices offers minimal installation efforts, unobtrusive monitoring and discreet data extraction.  However, these devices require strict protocols and controlled testing for adoption into research paradigms.  After reliability and validity testing, these devices may provide valuable insight into daily driving behaviors and intraindividual change over time for populations of older adults with and without AD.  Data can be aggregated over time to look at changes or adverse events and ascertain if decline in performance is occurring.

Testing for time-based correlates of perceived gender discrimination.

PubMed

Blau, Gary; Tatum, Donna Surges; Ward-Cook, Kory; Dobria, Lidia; McCoy, Keith

2005-01-01

Using a sample of 201 medical technologists (MTs) over a five-year period, this study extends initial findings on perceived gender discrimination (PGD) by Blau and Tatum (2000) by applying organizational justice variables and internal-external locus of control as hypothesized correlates of PGD. Three types of organizational justice were measured: distributive, procedural, and interactional. General relationships found include locus of control being related to PGD such that internals perceived lower PGD. Also, distributive, procedural, and interactional justice were negatively related to PGD. However, increasing the time interval between these correlates weakened their relationships. The relationship of interactional justice to PGD remained the most "resistant" to attenuation over time.

Cost-effectiveness of alternative changes to a national blood collection service.

PubMed

Willis, S; De Corte, K; Cairns, J A; Zia Sadique, M; Hawkins, N; Pennington, M; Cho, G; Roberts, D J; Miflin, G; Grieve, R

2018-05-16

To evaluate the cost-effectiveness of changing opening times, introducing a donor health report and reducing the minimum inter-donation interval for donors attending static centres. Evidence is required about the effect of changes to the blood collection service on costs and the frequency of donation. This study estimated the effect of changes to the blood collection service in England on the annual number of whole-blood donations by current donors. We used donors' responses to a stated preference survey, donor registry data on donation frequency and deferral rates from the INTERVAL trial. Costs measured were those anticipated to differ between strategies. We reported the cost per additional unit of blood collected for each strategy versus current practice. Strategies with a cost per additional unit of whole blood less than £30 (an estimate of the current cost of collection) were judged likely to be cost-effective. In static donor centres, extending opening times to evenings and weekends provided an additional unit of whole blood at a cost of £23 and £29, respectively. Introducing a health report cost £130 per additional unit of blood collected. Although the strategy of reducing the minimum inter-donation interval had the lowest cost per additional unit of blood collected (£10), this increased the rate of deferrals due to low haemoglobin (Hb). The introduction of a donor health report is unlikely to provide a sufficient increase in donation frequency to justify the additional costs. A more cost-effective change is to extend opening hours for blood collection at static centres. © 2018 The Authors. Transfusion Medicine published by John Wiley & Sons Ltd on behalf of British Blood Transfusion Society.

The stability of M(max) and H (max) amplitude over time.

PubMed

McNulty, Penelope A; Shiner, Christine T; Thayaparan, Ganesha K; Burke, David

2012-05-01

The stability of the maximal muscle response (M(max)) is critical to H reflex methodology. It has previously been reported that the amplitude of M(max) declines over time. If reproducible, this finding would have implications for all experimental studies that normalise the output of the motoneurone pool against the M wave. We investigated the effect of time on changes in M(max) and the maximal H reflex (H(max)) evoked at 4-s intervals over 60 min. To identify an influence of homosynaptic depression, we extended the interstimulus interval to 10 s and the time to 100 min. Two recording montages over soleus were used to ensure that interelectrode distance was not a critical factor. The soleus M(max) and H reflex were evoked by stimulation of the tibial nerve in the popliteal fossa in 7 subjects who sat with the knee flexed to 30° and the ankle plantar flexed by ~30°. We found no change in the pooled data for M(max), H(max), a reflex 50% of maximal, or the current required to produce it. However, one subject had a statistically significant increase in M(max) and a concurrent decrease in H(max) regardless of the interstimulus interval. On average, there was no change in the H(max)/M(max) ratio over time. While both M(max) and H(max) may change in response to many factors, these results suggest that, typically, time is not one of them.

Follow-up of early stage melanoma: specialist clinician perspectives on the functions of follow-up and implications for extending follow-up intervals.

PubMed

Rychetnik, Lucie; McCaffery, Kirsten; Morton, Rachael L; Thompson, John F; Menzies, Scott W; Irwig, Les

2013-04-01

There is limited evidence on the relative effectiveness of different follow-up schedules for patients with AJCC stage I or II melanoma, but less frequent follow-up than is currently recommended has been proposed. To describe melanoma clinicians' perspectives on the functions of follow-up, factors that influence follow-up intervals, and important considerations for extending intervals. Qualitative interviews with 16 clinicians (surgical oncologists, dermatologists, melanoma unit physicians) who conduct follow-up at two of Australia's largest specialist centers. Follow-up is conducted for early detection of recurrences or new primary melanomas, to manage patient anxiety, support patient self-care, and as part of shared care. Recommended intervals are based on guidelines but account for each patient's clinical risk profile, level of anxiety, patient education requirements, capacity to engage in skin self-examination, and how the clinician prefers to manage any suspicious lesions. To revise guidelines and implement change it is important to understand the rationale underpinning existing practice. Extended follow-up intervals for early stage melanoma are more likely to be adopted after the first year when patients are less anxious and sufficiently prepared to conduct self-examination. Clinicians may retain existing schedules for highly anxious patients or those unable to examine themselves. Copyright © 2012 Wiley Periodicals, Inc.

Extended Endoscopic Endonasal Resection of a Suprasellar and Third Ventricular Retrochiasmatic Craniopharyngioma with a Narrow Pituitary Gland-Optic Chiasm Interval: Techniques to Optimize Resection.

PubMed

Kenning, Tyler J; Pinheiro-Neto, Carlos D

2018-04-01

The extended endoscopic endonasal approach can be utilized to surgically treat pathology within the suprasellar space. This relies on a sufficient corridor and interval between the superior aspect of the pituitary gland and the optic chiasm. Tumors located in the retrochiasmatic space and within the third ventricle, however, may not have a widened interval through which to work. With mass effect on the superior and posterior aspect of the optic chiasm, the corridor between the chiasm and the pituitary gland might even be further narrowed. This may negate the possibility of utilizing the endoscopic endonasal approach for the management of pathology in this location. We present a case of a retrochiasmatic craniopharyngioma with a narrow resection corridor that was treated with the extended endoscopic approach and we review techniques to potentially overcome this limitation. The link to the video can be found at: https://youtu.be/ogRZj-aBqeQ .

Surface Detail Reproduction and Dimensional Stability of Contemporary Irreversible Hydrocolloid Alternatives after Immediate and Delayed Pouring

PubMed Central

Kusugal, Preethi; Chourasiya, Ritu Sunil; Ruttonji, Zarir; Astagi, Preeti; Nayak, Ajay Kumar; Patil, Abhishekha

2018-01-01

Purpose: To overcome the poor dimensional stability of irreversible hydrocolloids, alternative materials were introduced. The dimensional changes of these alternatives after delayed pouring are not well studied and documented in the literature. The purpose of the study is to evaluate and compare the surface detail reproduction and dimensional stability of two irreversible hydrocolloid alternatives with an extended-pour irreversible hydrocolloid at different time intervals. Materials and Methods: All testing were performed according to the ANSI/ADA specification number 18 for surface detail reproduction and specification number 19 for dimensional change. The test materials used in this study were newer irreversible hydrocolloid alternatives such as AlgiNot FS, Algin-X Ultra FS, and Kromopan 100 which is an extended pour irreversible hydrocolloid as control. The surface detail reproduction was evaluated using stereomicroscope. The dimensional change after storage period of 1 h, 24 h, and 120 h was assessed and compared between the test materials and control. The data were analyzed using one-way ANOVA and post hoc Bonferroni test. Results: Statistically significant results (P < 0.001) were seen when mean scores of the tested materials were compared with respect to reproduction of 22 μm line from the metal block. Kromopan 100 showed statistically significant differences between different time intervals (P < 0.001) and exhibited more dimensional change. Algin-X Ultra FS proved to be more accurate and dimensionally stable. Conclusions: Newer irreversible hydrocolloid alternative impression materials were more accurate in surface detail reproduction and exhibited minimal dimensional change after storage period of 1 h, 24 h, and 120 h than extended-pour irreversible hydrocolloid impression material. PMID:29599578

Extended Prandial Glycemic Profiles of Foods as Assessed Using Continuous Glucose Monitoring Enhance the Power of the 120-Minute Glycemic Index

PubMed Central

Chlup, Rudolf; Peterson, Karolina; Zapletalová, Jana; Kudlová, Pavla; Sečkař, Pavel

2010-01-01

Background The glycemic index (GI) is routinely measured 120 minutes after food intake (GI120). The purpose of this prospective open label study was to assess (1) the dynamics of glycemia over the 210 minutes following food consumption and (2) the evolution of GIs based on 120-, 150-, 180-, and 210-minute glycemic profiles. Method Twenty healthy subjects (mean ± SE; 21.9 ± 1.39 years of age; body mass index 23.6 ± 0.63 kg/m2; 7 men and 13 women) completed the study. Each subject consumed 10 different foods with known GI120 on three separate occasions at four different times of day according to a defined meal plan over a 9-day period; 32 meals were evaluated. The GIs for intervals of 120, 150, 180 and 210 minutes after food consumption were determined using a continuous glucose monitoring system (CGMS) to measure glycemia. The Wilcoxon signed-rank test was applied to compare the GIs. Results Glycemia returned to baseline within 120 minutes for honey and tomato soup; within 210 minutes for white bread, choco-rice cookies, fish and potatoes, wafers, and meat ravioli with cheese; and later for dark chocolate, apricot dumplings, and choco-wheat cookies. The extended GIs were higher than the respective GI120s in eight of the foods. Conclusions The 120-minute glycemic index fails to fully account for changes in glycemia after ingestion of a mixed meal because glycemia remains above baseline for a longer period. The CGMS is a convenient method to determine the glucose response/GIs over intervals extended up to 210 minutes, which is adequate time for the absorption of most foods. PMID:20513328

A fast ellipse extended target PHD filter using box-particle implementation

NASA Astrophysics Data System (ADS)

Zhang, Yongquan; Ji, Hongbing; Hu, Qi

2018-01-01

This paper presents a box-particle implementation of the ellipse extended target probability hypothesis density (ET-PHD) filter, called the ellipse extended target box particle PHD (EET-BP-PHD) filter, where the extended targets are described as a Poisson model developed by Gilholm et al. and the term "box" is here equivalent to the term "interval" used in interval analysis. The proposed EET-BP-PHD filter is capable of dynamically tracking multiple ellipse extended targets and estimating the target states and the number of targets, in the presence of clutter measurements, false alarms and missed detections. To derive the PHD recursion of the EET-BP-PHD filter, a suitable measurement likelihood is defined for a given partitioning cell, and the main implementation steps are presented along with the necessary box approximations and manipulations. The limitations and capabilities of the proposed EET-BP-PHD filter are illustrated by simulation examples. The simulation results show that a box-particle implementation of the ET-PHD filter can avoid the high number of particles and reduce computational burden, compared to a particle implementation of that for extended target tracking.

Modeling Pharmacological Clock and Memory Patterns of Interval Timing in a Striatal Beat-Frequency Model with Realistic, Noisy Neurons

PubMed Central

Oprisan, Sorinel A.; Buhusi, Catalin V.

2011-01-01

In most species, the capability of perceiving and using the passage of time in the seconds-to-minutes range (interval timing) is not only accurate but also scalar: errors in time estimation are linearly related to the estimated duration. The ubiquity of scalar timing extends over behavioral, lesion, and pharmacological manipulations. For example, in mammals, dopaminergic drugs induce an immediate, scalar change in the perceived time (clock pattern), whereas cholinergic drugs induce a gradual, scalar change in perceived time (memory pattern). How do these properties emerge from unreliable, noisy neurons firing in the milliseconds range? Neurobiological information relative to the brain circuits involved in interval timing provide support for an striatal beat frequency (SBF) model, in which time is coded by the coincidental activation of striatal spiny neurons by cortical neural oscillators. While biologically plausible, the impracticality of perfect oscillators, or their lack thereof, questions this mechanism in a brain with noisy neurons. We explored the computational mechanisms required for the clock and memory patterns in an SBF model with biophysically realistic and noisy Morris–Lecar neurons (SBF–ML). Under the assumption that dopaminergic drugs modulate the firing frequency of cortical oscillators, and that cholinergic drugs modulate the memory representation of the criterion time, we show that our SBF–ML model can reproduce the pharmacological clock and memory patterns observed in the literature. Numerical results also indicate that parameter variability (noise) – which is ubiquitous in the form of small fluctuations in the intrinsic frequencies of neural oscillators within and between trials, and in the errors in recording/retrieving stored information related to criterion time – seems to be critical for the time-scale invariance of the clock and memory patterns. PMID:21977014

Time-scale effects on the gain-loss asymmetry in stock indices

NASA Astrophysics Data System (ADS)

Sándor, Bulcsú; Simonsen, Ingve; Nagy, Bálint Zsolt; Néda, Zoltán

2016-08-01

The gain-loss asymmetry, observed in the inverse statistics of stock indices is present for logarithmic return levels that are over 2 % , and it is the result of the non-Pearson-type autocorrelations in the index. These non-Pearson-type correlations can be viewed also as functionally dependent daily volatilities, extending for a finite time interval. A generalized time-window shuffling method is used to show the existence of such autocorrelations. Their characteristic time scale proves to be smaller (less than 25 trading days) than what was previously believed. It is also found that this characteristic time scale has decreased with the appearance of program trading in the stock market transactions. Connections with the leverage effect are also established.

Meta-Analysis of Single-Case Research Design Studies on Instructional Pacing.

PubMed

Tincani, Matt; De Mers, Marilyn

2016-11-01

More than four decades of research on instructional pacing has yielded varying and, in some cases, conflicting findings. The purpose of this meta-analysis was to synthesize single-case research design (SCRD) studies on instructional pacing to determine the relative benefits of brisker or slower pacing. Participants were children and youth with and without disabilities in educational settings, excluding higher education. Tau-U, a non-parametric statistic for analyzing data in SCRD studies, was used to determine effect size estimates. The article extraction yielded 13 instructional pacing studies meeting contemporary standards for high quality SCRD research. Eleven of the 13 studies reported small to large magnitude effects when two or more pacing parameters were compared, suggesting that instructional pacing is a robust instructional variable. Brisker instructional pacing with brief inter-trial interval (ITI) produced small increases in correct responding and medium to large reductions in challenging behavior compared with extended ITI. Slower instructional pacing with extended wait-time produced small increases in correct responding, but also produced small increases in challenging behavior compared with brief wait-time. Neither brief ITI nor extended wait-time meets recently established thresholds for evidence-based practice, highlighting the need for further instructional pacing research. © The Author(s) 2016.

Remote effects of aversive contingencies: Disruption of appetitive behavior by adjacent avoidance sessions

PubMed Central

Hackenberg, Timothy D.; Hineline, Philip N.

1987-01-01

Disruption of ongoing appetitive behavior before and after daily avoidance sessions was examined. After baselines of appetitive responding were established under a fixed-interval 180-s schedule of food presentation, 4 rats were exposed to 40-min sessions of the appetitive schedule just prior to 100-min sessions of electric shock postponement, while another 4 rats received the 40-min appetitive sessions just following daily sessions of shock postponement. In all 8 subjects, fixed-interval response rates decreased relative to baseline levels, the effect being somewhat more pronounced when the avoidance sessions immediately followed. The disruption of fixed-interval responding was only partially reversed when avoidance sessions were discontinued. During the initial exposure to the avoidance sessions, patterns of responding under the fixed-interval schedule were differentially sensitive to disruption, with high baseline response rates generally more disturbed than low rates. These disruptions were not systematically related to changes in reinforcement frequency, which remained fairly high and invariant across all conditions of the experiment; they were also not systematically related to the response rates or to the shock rates of the adjacent avoidance sessions. The results, while qualitatively resembling patterns of conditioned suppression as typically studied, occurred on a greatly expanded time scale. As disruption of behavior extending over time, the present data suggest that some forms of conditioned suppression are perhaps best viewed within a larger temporal context. PMID:16812486

Study of temperature distributions in wafer exposure process

NASA Astrophysics Data System (ADS)

Lin, Zone-Ching; Wu, Wen-Jang

During the exposure process of photolithography, wafer absorbs the exposure energy, which results in rising temperature and the phenomenon of thermal expansion. This phenomenon was often neglected due to its limited effect in the previous generation of process. However, in the new generation of process, it may very likely become a factor to be considered. In this paper, the finite element model for analyzing the transient behavior of the distribution of wafer temperature during exposure was established under the assumption that the wafer was clamped by a vacuum chuck without warpage. The model is capable of simulating the distribution of the wafer temperature under different exposure conditions. The flowchart of analysis begins with the simulation of transient behavior in a single exposure region to the variation of exposure energy, interval of exposure locations and interval of exposure time under continuous exposure to investigate the distribution of wafer temperature. The simulation results indicate that widening the interval of exposure locations has a greater impact in improving the distribution of wafer temperature than extending the interval of exposure time between neighboring image fields. Besides, as long as the distance between the field center locations of two neighboring exposure regions exceeds the straight distance equals to three image fields wide, the interacting thermal effect during wafer exposure can be ignored. The analysis flow proposed in this paper can serve as a supporting reference tool for engineers in planning exposure paths.

A Comparison of Methods for Estimating Confidence Intervals for Omega-Squared Effect Size

ERIC Educational Resources Information Center

Finch, W. Holmes; French, Brian F.

2012-01-01

Effect size use has been increasing in the past decade in many research areas. Confidence intervals associated with effect sizes are encouraged to be reported. Prior work has investigated the performance of confidence interval estimation with Cohen's d. This study extends this line of work to the analysis of variance case with more than two…

The effect of extended wake on postural control in young adults.

PubMed

Smith, Simon S; Cheng, Tiffany; Kerr, Graham K

2012-09-01

The sleep-wake cycle is a major determinant of locomotor activity in humans, and the neural and physiological processes necessary for optimum postural control may be impaired by an extension of the wake period into habitual sleep time. There is growing evidence for such a contribution from sleep-related factors, but great inconsistency in the methods used to assess this contribution, particularly in control for circadian phase position. Postural control was assessed at hourly intervals across 14 h of extended wake in nine young adult participants. Force plate parameters of medio-lateral and anterior-posterior sway, centre of pressure (CoP) trace length, area, and velocity were assessed with eyes open and eyes closed over 3-min periods. A standard measure of psychomotor vigilance was assessed concurrently under constant routine conditions. After controlling for individual differences in circadian phase position, a significant effect of extended wake was found for anterior-posterior sway and for psychomotor vigilance. These data suggest that extended wake may increase the risk of a fall or other consequences of impaired postural control.

The new extended-cycle levonorgestrel-ethinyl estradiol oral contraceptives.

PubMed

Bonnema, Rachel A; Spencer, Abby L

2011-09-19

Effective contraceptive counseling requires an understanding of a woman's preferences and medical history as well as the risks, benefits, side effects, and contraindications of each contraceptive method. Hormonal contraceptives using a variety of delivery methods are highly effective and this review highlights the new extended-cycle levonorgestrel-ethinyl estradiol contraceptives. Extended-cycle OCPs are unique in offering fewer or no withdrawal bleeds over the course of one year but providers need to carefully counsel women regarding the initial increased breakthrough bleeding. Extended-cycle OCPs may be of particular benefit in women with medical comorbidities who would benefit from less withdrawal bleeds, those desiring to avoid monthly menses due to increased hormonal withdrawal symptoms, or simply women who don't desire a monthly period. The risks associated with all extended-cycle OCPs have been found to be similar to those of traditional OCPs therefore counseling on the risks and side effects is comparable to that of any combined hormonal contraceptives. Newer extended-cycle regimens shorten or eliminate the hormone-free interval, decrease frequency of menses to four times per year or eliminate menses altogether. This can reduce the risk of common menstrual symptoms, endometriosis, or severe dysmenorrhea by offering potentially greater ovarian suppression and preventing endogenous estradiol production while still providing highly effective, rapidly reversible, and safe contraception.

Response-cue interval effects in extended-runs task switching: memory, or monitoring?

PubMed

Altmann, Erik M

2017-09-26

This study investigated effects of manipulating the response-cue interval (RCI) in the extended-runs task-switching procedure. In this procedure, a task cue is presented at the start of a run of trials and then withdrawn, such that the task has to be stored in memory to guide performance until the next task cue is presented. The effects of the RCI manipulation were not as predicted by an existing model of memory processes in task switching (Altmann and Gray, Psychol Rev 115:602-639, 2008), suggesting that either the model is incorrect or the RCI manipulation did not have the intended effect. The manipulation did produce a theoretically meaningful pattern, in the form of a main effect on response time that was not accompanied by a similar effect on the error rate. This pattern, which replicated across two experiments, is interpreted here in terms of a process that monitors for the next task cue, with a longer RCI acting as a stronger signal that a cue is about to appear. The results have implications for the human factors of dynamic task environments in which critical events occur unpredictably.

Aspirin Does Not Increase Heart Failure Events in Heart Failure Patients: From the WARCEF Trial.

PubMed

Teerlink, John R; Qian, Min; Bello, Natalie A; Freudenberger, Ronald S; Levin, Bruce; Di Tullio, Marco R; Graham, Susan; Mann, Douglas L; Sacco, Ralph L; Mohr, J P; Lip, Gregory Y H; Labovitz, Arthur J; Lee, Seitetz C; Ponikowski, Piotr; Lok, Dirk J; Anker, Stefan D; Thompson, John L P; Homma, Shunichi

2017-08-01

The aim of this study was to determine whether aspirin increases heart failure (HF) hospitalization or death in patients with HF with reduced ejection fraction receiving an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). Because of its cyclooxygenase inhibiting properties, aspirin has been postulated to increase HF events in patients treated with ACE inhibitors or ARBs. However, no large randomized trial has addressed the clinical relevance of this issue. We compared aspirin and warfarin for HF events (hospitalization, death, or both) in the 2,305 patients enrolled in the WARCEF (Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction) trial (98.6% on ACE inhibitor or ARB treatment), using conventional Cox models for time to first event (489 events). In addition, to examine multiple HF hospitalizations, we used 2 extended Cox models, a conditional model and a total time marginal model, in time to recurrent event analyses (1,078 events). After adjustment for baseline covariates, aspirin- and warfarin-treated patients did not differ in time to first HF event (adjusted hazard ratio: 0.87; 95% confidence interval: 0.72 to 1.04; p = 0.117) or first hospitalization alone (adjusted hazard ratio: 0.88; 95% confidence interval: 0.73 to 1.06; p = 0.168). The extended Cox models also found no significant differences in all HF events or in HF hospitalizations alone after adjustment for covariates. Among patients with HF with reduced ejection fraction in the WARCEF trial, there was no significant difference in risk of HF events between the aspirin and warfarin-treated patients. (Warfarin Versus Aspirin in Reduced Cardiac Ejection Fraction trial [WARCEF]; NCT00041938). Copyright © 2017 American College of Cardiology Foundation. All rights reserved.

Do as I … Did! Long-term memory of imitative actions in dogs (Canis familiaris).

PubMed

Fugazza, Claudia; Pogány, Ákos; Miklósi, Ádám

2016-03-01

This study demonstrates long-term declarative memory of imitative actions in a non-human animal species. We tested 12 pet dogs for their ability to imitate human actions after retention intervals ranging from 1 to 24 h. For comparison, another 12 dogs were tested for the same actions without delay between demonstration and recall. Our test consisted of a modified version of the Do as I Do paradigm, combined with the two-action procedure to control for non-imitative processes. Imitative performance of dogs remained consistently high independent of increasing retention intervals, supporting the idea that dogs are able to retain mental representations of human actions for an extended period of time. The ability to imitate after such delays supports the use of long-term declarative memory.

A catalog of atmospheric densities from the drag on five balloon satellites

NASA Technical Reports Server (NTRS)

Jacchia, L. G.; Slowey, J. W.

1975-01-01

A catalog of atmospheric densities derived for the drag on five balloon satellites is presented. Much of the catalog was based on precisely reduced Baker-Nunn observations and, for that reason, provides much improved time resolution. The effect of direct solar radiation pressure was precisely evaluated, and that of terrestrial radiation pressure was included in every case. The interval covered for each satellite varies between 3.1 and 7.6 years, with the data extending from early 1961 to early 1973.

Fermi LAT Stacking Analysis of Swift Localized GRBs

DOE PAGES

Ackermann, M.; Ajello, M.; Anderson, B.; ...

2016-05-05

In this paper, we perform a comprehensive stacking analysis of data collected by the Fermi Large Area Telescope (LAT) of γ-ray bursts (GRBs) localized by the Swift spacecraft, which were not detected by the LAT but which fell within the instrument's field of view at the time of trigger. We examine a total of 79 GRBs by comparing the observed counts over a range of time intervals to that expected from designated background orbits, as well as by using a joint likelihood technique to model the expected distribution of stacked counts. We find strong evidence for subthreshold emission at MeVmore » to GeV energies using both techniques. This observed excess is detected during intervals that include and exceed the durations typically characterizing the prompt emission observed at keV energies and lasts at least 2700 s after the co-aligned burst trigger. By utilizing a novel cumulative likelihood analysis, we find that although a burst's prompt γ-ray and afterglow X-ray flux both correlate with the strength of the subthreshold emission, the X-ray afterglow flux measured by Swift's X-ray Telescope at 11 hr post trigger correlates far more significantly. Overall, the extended nature of the subthreshold emission and its connection to the burst's afterglow brightness lend further support to the external forward shock origin of the late-time emission detected by the LAT. Finally, these results suggest that the extended high-energy emission observed by the LAT may be a relatively common feature but remains undetected in a majority of bursts owing to instrumental threshold effects.« less

The application of prototype point processes for the summary and description of California wildfires

USGS Publications Warehouse

Nichols, K.; Schoenberg, F.P.; Keeley, J.E.; Bray, A.; Diez, D.

2011-01-01

A method for summarizing repeated realizations of a space-time marked point process, known as prototyping, is discussed and applied to catalogues of wildfires in California. Prototype summaries are constructed for varying time intervals using California wildfire data from 1990 to 2006. Previous work on prototypes for temporal and space-time point processes is extended here to include methods for computing prototypes with marks and the incorporation of prototype summaries into hierarchical clustering algorithms, the latter of which is used to delineate fire seasons in California. Other results include summaries of patterns in the spatial-temporal distribution of wildfires within each wildfire season. ?? 2011 Blackwell Publishing Ltd.

Analysis of pelvic rotation on the standard hip ventrodorsal extended radiographic view.

PubMed

Martins, João; Colaço, Bruno J; Ferreira, António J; Ginja, Mário M

2016-01-01

To study the symmetry of the iliac horizontal diameter (IHD) maximum obturator foramen width (OFW), ischiatic femoral overlap (IFO), pelvic horizontal radius (PHR), femoral head diameter (FHD), and obturator foramen area (OFA) parameters in the normal hip extended radiographic view and to evaluate the correlation of pelvic rotation with the magnitude of asymmetry of these parameters. Nine canine cadavers from adult, large and giant breeds were radiographed in standard hip extended views and with 2°, 4° and 6° degrees of rotation. The variables IHD, OFW, IFO, PHR, FHD, and OFA were analysed in radiographs. The IHD measurements exhibited repeatability, bilateral symmetry and 95% of confidence interval of asymmetry in different pelvic rotations without superposition (p <0.05); OFW and IFO exhibited repeatability, bilateral symmetry and a small superposition in 95% of confidence interval of asymmetry according different pelvic rotations; PHR, FHD and OFA exhibited repeatability, bilateral symmetry and unacceptable superposition in 95% of confidence interval of asymmetry depending on pelvic rotation. The IHD is the recommended variable and OFW is an acceptable variable in order to evaluate slight pelvic rotation. The data may be used in qualitative analyses of hip extended radiographic views. In the future, complementary studies should be performed to evaluate the impact of degree of pelvic rotation on the hip dysplasia score.

Effects of an extended flexible regimen of an oral contraceptive pill containing 20 μg ethinylestradiol and 3 mg drospirenone on menstrual-related symptoms: a randomised controlled trial.

PubMed

Machado, Rogério Bonassi; Pompei, Luciano Melo; Badalotti, Mariangela; Ferriani, Rui; Cruz, Achilles M; Nahas, Eliana; Maia, Hugo

2017-02-01

The aim of the study was to assess the efficacy for menstrual-related symptoms of an extended flexible regimen of an oral contraceptive pill containing 20 μg ethinylestradiol and 3 mg drospirenone in comparison with a 24/4 d cyclical regimen of the same formulation. This randomised, non-inferiority, open-label, multicentre study was conducted in women aged 18-39 years. Their menstrual-related symptoms were assessed using the Penn Daily Symptom Rating (DSR17). Participants were randomised to use an extended flexible regimen of 20 μg ethinylestradiol and 3 mg drospirenone (EE/DRSP e.flex ), comprising 168 consecutive days with a 4-d hormone-free interval (HFI, allowing for management of unexpected bleeding) or a conventional 24/4 cyclical regimen of the same pill (EE/DRSP 24/4 ). The primary measure of efficacy was the percentage change in DSR17 total score from baseline to cycle 6. The secondary measures of efficacy were the percentage changes in DSR17 total score from baseline after each 28-d interval throughout the entire study and in the scores for individual DSR17 symptoms. The primary analysis demonstrated that EE/DRSP e.flex was not inferior to EE/DRSP 24/4 (Mean DSR17 score 9.1; 95% confidence interval (CI) - 2.5, 20.6; p = 0.123). Analysis at intervals throughout the entire evaluation period showed greater reduction in DSR17 total score for EE/DRSP e.flex than for the 24/4 regimen (p < 0.001). The decreases in individual scores for the symptoms 'poor coordination' and 'depression/feeling sad/down or blue' were greater for the extended flexible regimen than for the cyclical regimen (p < 0.05). The extended flexible regimen was not inferior to the 24/4 cyclical regimen in terms of the primary endpoint. It significantly improved symptoms in the interval analysis, and the effects on specific DSR17 symptoms, compared with the cyclical regimen.

Determining diabetic retinopathy screening interval based on time from no retinopathy to laser therapy.

PubMed

Hughes, Daniel; Nair, Sunil; Harvey, John N

2017-12-01

Objectives To determine the necessary screening interval for retinopathy in diabetic patients with no retinopathy based on time to laser therapy and to assess long-term visual outcome following screening. Methods In a population-based community screening programme in North Wales, 2917 patients were followed until death or for approximately 12 years. At screening, 2493 had no retinopathy; 424 had mostly minor degrees of non-proliferative retinopathy. Data on timing of first laser therapy and visual outcome following screening were obtained from local hospitals and ophthalmology units. Results Survival analysis showed that very few of the no retinopathy at screening group required laser therapy in the early years compared with the non-proliferative retinopathy group ( p < 0.001). After two years, <0.1% of the no retinopathy at screening group required laser therapy, and at three years 0.2% (cumulative), lower rates of treatment than have been suggested by analyses of sight-threatening retinopathy determined photographically. At follow-up (mean 7.8 ± 4.6 years), mild to moderate visual impairment in one or both eyes due to diabetic retinopathy was more common in those with retinopathy at screening (26% vs. 5%, p < 0.001), but blindness due to diabetes occurred in only 1 in 1000. Conclusions Optimum screening intervals should be determined from time to active treatment. Based on requirement for laser therapy, the screening interval for diabetic patients with no retinopathy can be extended to two to three years. Patients who attend for retinal screening and treatment who have no or non-proliferative retinopathy now have a very low risk of eventual blindness from diabetes.

Surface deformation time series and source modeling for a volcanic complex system based on satellite wide swath and image mode interferometry: The Lazufre system, central Andes

NASA Astrophysics Data System (ADS)

Anderssohn, J.; Motagh, M.; Walter, T. R.; Rosenau, M.; Kaufmann, H.; Oncken, O.

2009-12-01

The variable spatio-temporal scales of Earth's surface deformation in potentially hazardous volcanic areas pose a challenge for observation and assessment. Here we used Envisat data acquired in Wide Swath Mode (WSM) and Image Mode (IM) from ascending and descending geometry, respectively, to study time-dependent ground uplift at the Lazufre volcanic system in Chile and Argentina. A least-squares adjustment was performed on 65 IM interferograms that covered the time period of 2003-2008. We obtained a clear trend of uplift reaching 15-16 cm in this 5-year interval. Using a joint inversion of ascending and descending interferograms, we evaluated the geometry and time-dependent progression of a horizontally extended pressurized source beneath the Lazufre volcanic system. Our results hence indicate that an extended magma body at a depth between 10 and 15 km would account for most of the ground uplift. The maximum inflation reached up to ~40 cm during 2003-2008. The lateral propagation velocity of the intrusion was estimated to be nearly constant at 5-10 km/yr during the observation time, which has important implications for the physical understanding of magma intrusion processes.

Catalytic Reduction of 4-Nitrophenol: A Quantitative Assessment of the Role of Dissolved Oxygen in Determining the Induction Time.

PubMed

Menumerov, Eredzhep; Hughes, Robert A; Neretina, Svetlana

2016-12-14

The reduction of 4-nitrophenol to 4-aminophenol by borohydride is one of the foremost model catalytic reactions because it allows for a straightforward assessment of catalysts using the kinetic parameters extracted from the real-time spectroscopic monitoring of an aqueous solution. Crucial to its standing as a model reaction is a comprehensive mechanistic framework able to explain the entire time evolution of the reaction. While much of this framework is in place, there is still much debate over the cause of the induction period, an initial time interval where no reaction seemingly occurs. Here, we report on the simultaneous monitoring of the spectroscopic signal and the dissolved oxygen content within the aqueous solution. It reveals that the induction period is the time interval required for the level of dissolved oxygen to fall below a critical value that is dependent upon whether Au, Ag, or Pd nanoparticles are used as the catalyst. With this understanding, we are able to exert complete control over the induction period, being able to eliminate it, extend it indefinitely, or even induce multiple induction periods over the course of a single reaction. Moreover, we have determined that the reaction product, 4-aminophenol, in the presence of the same catalyst reacts with dissolved oxygen to form 4-nitrophenolate. The implication of these results is that the induction period relates, not to some activation of the catalyst, but to a time interval where the reaction product is being rapidly transformed back into a reactant by a side reaction.

Evaluation of the concept of pressure proof testing fuselage structures

NASA Technical Reports Server (NTRS)

Harris, Charles E.; Orringer, Oscar

1991-01-01

The FAA and NASA have recently completed independent technical evaluations of the concept of pressure proof testing the fuselage of commercial transport airplanes. The results of these evaluations are summarized. The objectives of the evaluations were to establish the potential benefit of the pressure proof test, to quantify the most desirable proof test pressure, and to quantify the required proof test interval. The focus of the evaluations was on multiple-site cracks extending from adjacent rivet holes of a typical fuselage longitudinal lap splice joint. The FAA and NASA do not support pressure proof testing the fuselage of aging commercial transport aircraft. The argument against proof testing is as follows: (1) a single proof test does not insure an indefinite life; therefore, the proof test must be repeated at regular intervals; (2) for a proof factor of 1.33, the required proof test interval must be below 300 flights to account for uncertainties in the evaluation; (3) conducting the proof test at a proof factor of 1.5 would considerably exceed the fuselage design limit load; therefore, it is not consistent with accepted safe practices; and (4) better safety can be assured by implementing enhanced nondestructive inspection requirements, and adequate reliability can be achieved by an inspection interval several times longer than the proof test interval.

Interval MULTIMOORA method with target values of attributes based on interval distance and preference degree: biomaterials selection

NASA Astrophysics Data System (ADS)

Hafezalkotob, Arian; Hafezalkotob, Ashkan

2017-06-01

A target-based MADM method covers beneficial and non-beneficial attributes besides target values for some attributes. Such techniques are considered as the comprehensive forms of MADM approaches. Target-based MADM methods can also be used in traditional decision-making problems in which beneficial and non-beneficial attributes only exist. In many practical selection problems, some attributes have given target values. The values of decision matrix and target-based attributes can be provided as intervals in some of such problems. Some target-based decision-making methods have recently been developed; however, a research gap exists in the area of MADM techniques with target-based attributes under uncertainty of information. We extend the MULTIMOORA method for solving practical material selection problems in which material properties and their target values are given as interval numbers. We employ various concepts of interval computations to reduce degeneration of uncertain data. In this regard, we use interval arithmetic and introduce innovative formula for interval distance of interval numbers to create interval target-based normalization technique. Furthermore, we use a pairwise preference matrix based on the concept of degree of preference of interval numbers to calculate the maximum, minimum, and ranking of these numbers. Two decision-making problems regarding biomaterials selection of hip and knee prostheses are discussed. Preference degree-based ranking lists for subordinate parts of the extended MULTIMOORA method are generated by calculating the relative degrees of preference for the arranged assessment values of the biomaterials. The resultant rankings for the problem are compared with the outcomes of other target-based models in the literature.

Unmet need for modern contraceptives and associated factors among women in the extended postpartum period in Dessie town, Ethiopia.

PubMed

Tegegn, Masresha; Arefaynie, Mastewal; Tiruye, Tenaw Yimer

2017-01-01

The contraceptive use of women in the extended postpartum period is usually different from other times in a woman's life cycle due to the additional roles and presence of emotional changes. However, there is lack of evidence regarding women contraceptive need during this period and the extent they met their need. Therefore, the objective of this study was to assess unmet need for modern contraceptives and associated factors among women during the extended postpartum period in Dessie Town, North east Ethiopia in December 2014. A community-based cross-sectional study was conducted among women who gave birth one year before the study period. Systematic random sampling technique was employed to recruit a total of 383 study participants. For data collection, a structured and pretested standard questionnaire was used. Descriptive statistics were done to characterize the study population using different variables. Bivariate and multiple logistic regression models were fitted to control confounding factors. Odds ratios with 95% confidence intervals were computed to identify factors associated with unmet need. This study revealed that 44% of the extended post-partum women had unmet need of modern contraceptives of which 57% unmet need for spacing and 43% for limiting. Education of women (being illiterate) (AOR (adjusted odds ratio) =3.37, 95% CI (confidence interval) 1.22-7.57), antenatal care service (no) (AOR = 2.41, 95% CI 1.11-5.79), Post-natal care service (no) (AOR = 3.63, CI 2.13-6.19) and knowledge of lactational amenorrhea method (AOR = 7.84 95% CI 4.10-15.02) were the factors positively associated with unmet need modern contraceptives in the extended postpartum period. The unmet need for modern contraception is high in the study area. There is need to improve the quality of maternal health service, girls education, information on postpartum risk of pregnancy on the recommended postpartum contraceptives to enable mothers make informed choices of contraceptives.

The cyclic and fractal seismic series preceding an mb 4.8 earthquake on 1980 February 14 near the Virgin Islands

USGS Publications Warehouse

Varnes, D.J.; Bufe, C.G.

1996-01-01

Seismic activity in the 10 months preceding the 1980 February 14, mb 4.8 earthquake in the Virgin Islands, reported on by Frankel in 1982, consisted of four principal cycles. Each cycle began with a relatively large event or series of closely spaced events, and the duration of the cycles progressively shortened by a factor of about 3/4. Had this regular shortening of the cycles been recognized prior to the earthquake, the time of the next episode of setsmicity (the main shock) might have been closely estimated 41 days in advance. That this event could be much larger than the previous events is indicated from time-to-failure analysis of the accelerating rise in released seismic energy, using a non-linear time- and slip-predictable foreshock model. Examination of the timing of all events in the sequence shows an even higher degree of order. Rates of seismicity, measured by consecutive interevent times, when plotted on an iteration diagram of a rate versus the succeeding rate, form a triangular circulating trajectory. The trajectory becomes an ascending helix if extended in a third dimension, time. This construction reveals additional and precise relations among the time intervals between times of relatively high or relatively low rates of seismic activity, including period halving and doubling. The set of 666 time intervals between all possible pairs of the 37 recorded events appears to be a fractal; the set of time points that define the intervals has a finite, non-integer correlation dimension of 0.70. In contrast, the average correlation dimension of 50 random sequences of 37 events is significantly higher, dose to 1.0. In a similar analysis, the set of distances between pairs of epicentres has a fractal correlation dimension of 1.52. Well-defined cycles, numerous precise ratios among time intervals, and a non-random temporal fractal dimension suggest that the seismic series is not a random process, but rather the product of a deterministic dynamic system.

Evaluating Protocol Lifecycle Time Intervals in HIV/AIDS Clinical Trials

PubMed Central

Schouten, Jeffrey T.; Dixon, Dennis; Varghese, Suresh; Cope, Marie T.; Marci, Joe; Kagan, Jonathan M.

2014-01-01

Background Identifying efficacious interventions for the prevention and treatment of human diseases depends on the efficient development and implementation of controlled clinical trials. Essential to reducing the time and burden of completing the clinical trial lifecycle is determining which aspects take the longest, delay other stages, and may lead to better resource utilization without diminishing scientific quality, safety, or the protection of human subjects. Purpose In this study we modeled time-to-event data to explore relationships between clinical trial protocol development and implementation times, as well as identify potential correlates of prolonged development and implementation. Methods We obtained time interval and participant accrual data from 111 interventional clinical trials initiated between 2006 and 2011 by NIH’s HIV/AIDS Clinical Trials Networks. We determined the time (in days) required to complete defined phases of clinical trial protocol development and implementation. Kaplan-Meier estimates were used to assess the rates at which protocols reached specified terminal events, stratified by study purpose (therapeutic, prevention) and phase group (pilot/phase I, phase II, and phase III/ IV). We also examined several potential correlates to prolonged development and implementation intervals. Results Even though phase grouping did not determine development or implementation times of either therapeutic or prevention studies, overall we observed wide variation in protocol development times. Moreover, we detected a trend toward phase III/IV therapeutic protocols exhibiting longer developmental (median 2 ½ years) and implementation times (>3years). We also found that protocols exceeding the median number of days for completing the development interval had significantly longer implementation. Limitations The use of a relatively small set of protocols may have limited our ability to detect differences across phase groupings. Some timing effects present for a specific study phase may have been masked by combining protocols into phase groupings. Presence of informative censoring, such as withdrawal of some protocols from development if they began showing signs of lost interest among investigators, complicates interpretation of Kaplan-Meier estimates. Because this study constitutes a retrospective examination over an extended period of time, it does not allow for the precise identification of relative factors impacting timing. Conclusions Delays not only increase the time and cost to complete clinical trials, but they also diminish their usefulness by failing to answer research questions in time. We believe that research analyzing the time spent traversing defined intervals across the clinical trial protocol development and implementation continuum can stimulate business process analyses and reengineering efforts that could lead to reductions in the time from clinical trial concept to results, thereby accelerating progress in clinical research. PMID:24980279

Supporting temporal queries on clinical relational databases: the S-WATCH-QL language.

PubMed Central

Combi, C.; Missora, L.; Pinciroli, F.

1996-01-01

Due to the ubiquitous and special nature of time, specially in clinical datábases there's the need of particular temporal data and operators. In this paper we describe S-WATCH-QL (Structured Watch Query Language), a temporal extension of SQL, the widespread query language based on the relational model. S-WATCH-QL extends the well-known SQL by the addition of: a) temporal data types that allow the storage of information with different levels of granularity; b) historical relations that can store together both instantaneous valid times and intervals; c) some temporal clauses, functions and predicates allowing to define complex temporal queries. PMID:8947722

Cross-sample entropy of foreign exchange time series

NASA Astrophysics Data System (ADS)

Liu, Li-Zhi; Qian, Xi-Yuan; Lu, Heng-Yao

2010-11-01

The correlation of foreign exchange rates in currency markets is investigated based on the empirical data of DKK/USD, NOK/USD, CAD/USD, JPY/USD, KRW/USD, SGD/USD, THB/USD and TWD/USD for a period from 1995 to 2002. Cross-SampEn (cross-sample entropy) method is used to compare the returns of every two exchange rate time series to assess their degree of asynchrony. The calculation method of confidence interval of SampEn is extended and applied to cross-SampEn. The cross-SampEn and its confidence interval for every two of the exchange rate time series in periods 1995-1998 (before the Asian currency crisis) and 1999-2002 (after the Asian currency crisis) are calculated. The results show that the cross-SampEn of every two of these exchange rates becomes higher after the Asian currency crisis, indicating a higher asynchrony between the exchange rates. Especially for Singapore, Thailand and Taiwan, the cross-SampEn values after the Asian currency crisis are significantly higher than those before the Asian currency crisis. Comparison with the correlation coefficient shows that cross-SampEn is superior to describe the correlation between time series.

Long-term tolerability of ethinylestradiol 20 μg/drospirenone 3 mg in a flexible extended regimen: results from a randomised, controlled, multicentre study.

PubMed

Klipping, Christine; Duijkers, Ingrid; Fortier, Michel P; Marr, Joachim; Trummer, Dietmar; Elliesen, Jörg

2012-04-01

This study was designed to assess the long-term safety and tolerability of a new flexible extended regimen of ethinylestradiol (EE) 20 μg/drospirenone (DRSP) 3 mg, which allows management of intracyclic (breakthrough) bleeding [flexible management of intracyclic (breakthrough) bleeding (MIB)], in comparison to conventional 28-day and fixed extended regimens. In this Phase III, multicentre, open-label study, women (aged 18-35 years) were randomised to EE/DRSP in the following regimens: flexible(MIB) (24-120 days' active hormonal intake followed by a 4-day tablet-free interval), conventional 28-day (24 days' active hormonal intake followed by a 4-day hormone-free interval) or fixed extended (120 days' uninterrupted active hormonal intake followed by a 4-day tablet-free interval) during a 1-year comparative phase. Thereafter, women entered a 1-year safety extension phase in which the majority received the flexible(MIB) regimen. Safety/tolerability outcomes were measured over 2 years. A separate analysis of certain safety parameters (endometrial, hormonal, lipid, haemostatic and metabolic variables) was conducted at two of the study centres. Results were analysed in 1067 and 783 women in the comparative and safety extension phases. Overall, 56.3% of women experienced ≥1 adverse event (AE) in the safety extension phase. Serious AEs occurred in 3.0%, 1.4% and 3.3% of women receiving the flexible(MIB), conventional and fixed extended regimens, respectively. No unexpected endometrial, hormonal, lipid, haemostatic or metabolic findings occurred with any of the three regimens. EE/DRSP in a flexible extended regimen with management of intracyclic (breakthrough) bleeding is well-tolerated and, when administered for up to 2 years, has a good safety profile comparable to other estrogen/progestogen oral contraceptives.

Fluctuations in Wikipedia access-rate and edit-event data

NASA Astrophysics Data System (ADS)

Kämpf, Mirko; Tismer, Sebastian; Kantelhardt, Jan W.; Muchnik, Lev

2012-12-01

Internet-based social networks often reflect extreme events in nature and society by drastic increases in user activity. We study and compare the dynamics of the two major complex processes necessary for information spread via the online encyclopedia ‘Wikipedia’, i.e., article editing (information upload) and article access (information viewing) based on article edit-event time series and (hourly) user access-rate time series for all articles. Daily and weekly activity patterns occur in addition to fluctuations and bursting activity. The bursts (i.e., significant increases in activity for an extended period of time) are characterized by a power-law distribution of durations of increases and decreases. For describing the recurrence and clustering of bursts we investigate the statistics of the return intervals between them. We find stretched exponential distributions of return intervals in access-rate time series, while edit-event time series yield simple exponential distributions. To characterize the fluctuation behavior we apply detrended fluctuation analysis (DFA), finding that most article access-rate time series are characterized by strong long-term correlations with fluctuation exponents α≈0.9. The results indicate significant differences in the dynamics of information upload and access and help in understanding the complex process of collecting, processing, validating, and distributing information in self-organized social networks.

Offset-frequency locking of extended-cavity diode lasers for precision spectroscopy of water at 1.38 μm.

PubMed

Gianfrani, Livio; Castrillo, Antonio; Fasci, Eugenio; Galzerano, Gianluca; Casa, Giovanni; Laporta, Paolo

2010-10-11

We describe a continuous-wave diode laser spectrometer for water-vapour precision spectroscopy at 1.38 μm. The spectrometer is based upon the use of a simple scheme for offset-frequency locking of a pair of extended-cavity diode lasers that allows to achieve unprecedented accuracy and reproducibility levels in measuring molecular absorption. When locked to the master laser with an offset frequency of 1.5 GHz, the slave laser exhibits residual frequency fluctuations of 1 kHz over a time interval of 25 minutes, for a 1-s integration time. The slave laser could be continuously tuned up to 3 GHz, the scan showing relative deviations from linearity below the 10{-6} level. Simultaneously, a capture range of the order of 1 GHz was obtained. Quantitative spectroscopy was also demonstrated by accurately determining relevant spectroscopic parameters for the 22,1→22,0line of the H2(18)O v1+v3 band at 1384.6008 nm.

Periodicity in the autocorrelation function as a mechanism for regularly occurring zero crossings or extreme values of a Gaussian process.

PubMed

Wilson, Lorna R M; Hopcraft, Keith I

2017-12-01

The problem of zero crossings is of great historical prevalence and promises extensive application. The challenge is to establish precisely how the autocorrelation function or power spectrum of a one-dimensional continuous random process determines the density function of the intervals between the zero crossings of that process. This paper investigates the case where periodicities are incorporated into the autocorrelation function of a smooth process. Numerical simulations, and statistics about the number of crossings in a fixed interval, reveal that in this case the zero crossings segue between a random and deterministic point process depending on the relative time scales of the periodic and nonperiodic components of the autocorrelation function. By considering the Laplace transform of the density function, we show that incorporating correlation between successive intervals is essential to obtaining accurate results for the interval variance. The same method enables prediction of the density function tail in some regions, and we suggest approaches for extending this to cover all regions. In an ever-more complex world, the potential applications for this scale of regularity in a random process are far reaching and powerful.

Periodicity in the autocorrelation function as a mechanism for regularly occurring zero crossings or extreme values of a Gaussian process

NASA Astrophysics Data System (ADS)

Wilson, Lorna R. M.; Hopcraft, Keith I.

2017-12-01

The problem of zero crossings is of great historical prevalence and promises extensive application. The challenge is to establish precisely how the autocorrelation function or power spectrum of a one-dimensional continuous random process determines the density function of the intervals between the zero crossings of that process. This paper investigates the case where periodicities are incorporated into the autocorrelation function of a smooth process. Numerical simulations, and statistics about the number of crossings in a fixed interval, reveal that in this case the zero crossings segue between a random and deterministic point process depending on the relative time scales of the periodic and nonperiodic components of the autocorrelation function. By considering the Laplace transform of the density function, we show that incorporating correlation between successive intervals is essential to obtaining accurate results for the interval variance. The same method enables prediction of the density function tail in some regions, and we suggest approaches for extending this to cover all regions. In an ever-more complex world, the potential applications for this scale of regularity in a random process are far reaching and powerful.

Contraceptive efficacy and tolerability of ethinylestradiol 20 μg/drospirenone 3 mg in a flexible extended regimen: an open-label, multicentre, randomised, controlled study.

PubMed

Klipping, Christine; Duijkers, Ingrid; Fortier, Michel P; Marr, Joachim; Trummer, Dietmar; Elliesen, Jörg

2012-04-01

The contraceptive efficacy and tolerability of a new flexible extended regimen of ethinylestradiol (EE) 20 μg/drospirenone (DRSP) 3 mg to extend the menstrual cycle and enable management of intracyclic (breakthrough) bleeding (flexible(MIB)) was investigated and the bleeding pattern compared with a conventional 28-day regimen and a fixed extended 124-day regimen. This Phase III, 2-year, multicentre, open-label study randomly (4:1:1) allocated women (aged 18-35 years) to the following regimens: flexible(MIB) (24-120 days' active hormonal intake with 4-day tablet-free intervals); conventional (24 days' active hormonal intake followed by a 4-day hormone-free interval); or fixed extended (120 days' uninterrupted active hormonal intake followed by a 4-day tablet-free interval). Primary outcomes included the number of bleeding/spotting days during Year 1 (all regimens) and the number of observed unintended pregnancies over 2 years (flexible(MIB) only). Results were analysed in 1067 women (full analysis set). The mean number of bleeding/spotting days was lower with the flexible(MIB) vs the conventional regimen [41.0±29.1 (95% CI 38.8-43.3) vs 65.8±27.0 (95% CI 62.2-69.4) days, p<0.0001; treatment difference -24.8 (95% CI -29.2 to -20.3) days]. The corresponding value for the fixed extended regimen was 60.9±51.1 (95% CI 53.9-67.9) days. The Pearl Index for the flexible(MIB) regimen was 0.64 (95% CI 0.28-1.26). All regimens had comparable tolerability profiles. EE 20 μg/DRSP 3 mg administered as a flexible extended regimen with MIB is effective, well tolerated and is associated with statistically significantly fewer bleeding/spotting days and fewer withdrawal bleeding episodes vs EE/DRSP in a conventional 28-day regimen. The flexible(MIB) also provided statistically significantly fewer spotting days vs EE/DRSP in a fixed extended 124-day regimen (post hoc evaluation). The flexible(MIB) regimen allows women to extend their menstrual cycle and manage their intracyclic (breakthrough) bleeding.

One-way ANOVA based on interval information

NASA Astrophysics Data System (ADS)

Hesamian, Gholamreza

2016-08-01

This paper deals with extending the one-way analysis of variance (ANOVA) to the case where the observed data are represented by closed intervals rather than real numbers. In this approach, first a notion of interval random variable is introduced. Especially, a normal distribution with interval parameters is introduced to investigate hypotheses about the equality of interval means or test the homogeneity of interval variances assumption. Moreover, the least significant difference (LSD method) for investigating multiple comparison of interval means is developed when the null hypothesis about the equality of means is rejected. Then, at a given interval significance level, an index is applied to compare the interval test statistic and the related interval critical value as a criterion to accept or reject the null interval hypothesis of interest. Finally, the method of decision-making leads to some degrees to accept or reject the interval hypotheses. An applied example will be used to show the performance of this method.

Effect of extended morning fasting upon ad libitum lunch intake and associated metabolic and hormonal responses in obese adults.

PubMed

Chowdhury, E A; Richardson, J D; Tsintzas, K; Thompson, D; Betts, J A

2016-02-01

Breakfast omission is positively associated with obesity and increased risk of disease. However, little is known about the acute effects of extended morning fasting upon subsequent energy intake and associated metabolic/regulatory factors in obese adults. In a randomised cross-over design, 24 obese men (n=8) and women (n=16) extended their overnight fast by omitting breakfast consumption or ingesting a typical carbohydrate-rich breakfast of 2183±393 kJ (521±94 kcal), before an ad libitum pasta lunch 3 h later. Blood samples were obtained throughout the day until 3 h post lunch and analysed for hormones implicated in appetite regulation, along with metabolic outcomes and subjective appetite measures. Lunch intake was unaffected by extended morning fasting (difference=218 kJ, 95% confidence interval -54 kJ, 490 kJ; P=0.1) resulting in lower total intake in the fasting trial (difference=-1964 kJ, 95% confidence interval -1645 kJ, -2281 kJ; P<0.01). Systemic concentrations of peptide tyrosine-tyrosine and leptin were lower during the afternoon following morning fasting (P⩽0.06). Plasma-acylated ghrelin concentrations were also lower following the ad libitum lunch in the fasting trial (P<0.05) but this effect was not apparent for total ghrelin (P⩾0.1). Serum insulin concentrations were greater throughout the afternoon in the fasting trial (P=0.05), with plasma glucose also greater 1 h after lunch (P<0.01). Extended morning fasting did not result in greater appetite ratings after lunch, with some tendency for lower appetite 3 h post lunch (P=0.09). We demonstrate for the first time that, in obese adults, extended morning fasting does not cause compensatory intake during an ad libitum lunch nor does it increase appetite during the afternoon. Morning fasting reduced satiety hormone responses to a subsequent lunch meal but counterintuitively also reduced concentrations of the appetite-stimulating hormone-acylated ghrelin during the afternoon relative to lunch consumed after breakfast.

Effect of extended morning fasting upon ad libitum lunch intake and associated metabolic and hormonal responses in obese adults

PubMed Central

Chowdhury, E A; Richardson, J D; Tsintzas, K; Thompson, D; Betts, J A

2016-01-01

Background/Objectives: Breakfast omission is positively associated with obesity and increased risk of disease. However, little is known about the acute effects of extended morning fasting upon subsequent energy intake and associated metabolic/regulatory factors in obese adults. Subjects/Methods: In a randomised cross-over design, 24 obese men (n=8) and women (n=16) extended their overnight fast by omitting breakfast consumption or ingesting a typical carbohydrate-rich breakfast of 2183±393 kJ (521±94 kcal), before an ad libitum pasta lunch 3 h later. Blood samples were obtained throughout the day until 3 h post lunch and analysed for hormones implicated in appetite regulation, along with metabolic outcomes and subjective appetite measures. Results: Lunch intake was unaffected by extended morning fasting (difference=218 kJ, 95% confidence interval −54 kJ, 490 kJ; P=0.1) resulting in lower total intake in the fasting trial (difference=−1964 kJ, 95% confidence interval −1645 kJ, −2281 kJ; P<0.01). Systemic concentrations of peptide tyrosine–tyrosine and leptin were lower during the afternoon following morning fasting (P⩽0.06). Plasma-acylated ghrelin concentrations were also lower following the ad libitum lunch in the fasting trial (P<0.05) but this effect was not apparent for total ghrelin (P⩾0.1). Serum insulin concentrations were greater throughout the afternoon in the fasting trial (P=0.05), with plasma glucose also greater 1 h after lunch (P<0.01). Extended morning fasting did not result in greater appetite ratings after lunch, with some tendency for lower appetite 3 h post lunch (P=0.09). Conclusions: We demonstrate for the first time that, in obese adults, extended morning fasting does not cause compensatory intake during an ad libitum lunch nor does it increase appetite during the afternoon. Morning fasting reduced satiety hormone responses to a subsequent lunch meal but counterintuitively also reduced concentrations of the appetite-stimulating hormone-acylated ghrelin during the afternoon relative to lunch consumed after breakfast. PMID:26278005

Modifications of the G6G timed-AI protocol improved pregnancy per AI and reduced pregnancy loss in lactating dairy cows.

PubMed

Heidari, F; Dirandeh, E; Ansari Pirsaraei, Z; Colazo, M G

2017-11-01

In dairy cows, subjected to a G6G protocol, objectives were to determine effects of (1) extending the interval from prostaglandin F2α (PGF2α) to gonadotropin-releasing hormone (GnRH) during presynchronization; and (2) adding a second PGF2α treatment before artificial insemination (AI), on ovarian response, plasma progesterone (P4) concentrations and pregnancy per AI (P/AI). In a 2×2 factorial design, lactating cows were randomly assigned to one of four timed AI (TAI) protocols: (1) G6G (n=149), one injection of PGF2α, GnRH 2 days later and a 7-day Ovsynch (GnRH, 7 days, PGF2α, 56 h, GnRH, 16 h, TAI) was initiated 6 days later; (2) G6GP (n=144), an additional PGF2α treatment (24 h after the first) during Ovsynch of the G6G protocol; (3) MG6G, one injection of PGF2α, GnRH 4 days later before initiation of the G6G protocol; and (4) MG6GP, an additional PGF2α treatment (24 h after the first) during Ovsynch of the MG6G protocol. Blood samples were collected (subset of 200 cows) at first GnRH and PGF2α of the Ovsynch, and at TAI to measure P4. Ultrasound examinations were performed in a subset of 406 cows to evaluate ovarian response at various times of Ovsynch, and in all cattle to determine pregnancy status at 32 and 60 days after TAI. Extending the interval by 2 days between PGF2α and GnRH during presynchronization increased (P<0.01) ovulatory response to first GnRH of Ovsynch, circulating P4 during Ovsynch, and P/AI at 32 and 60 days after TAI. Adding a second PGF2α treatment before AI increased the proportion of cows with luteal regression (P=0.04), improved P/AI at 60 days after TAI (P=0.05), and reduced pregnancy loss between 30 and 60 days after TAI (P=0.04). In summary, extending the interval from PGF2α to GnRH during presynchronization increased response to first GnRH of Ovsynch and P4 concentrations during Ovsynch, whereas adding a second PGF2α treatment before AI enhanced luteal regression. Both modifications of the G6G protocol improved fertility in lactating dairy cows.

Progress on the Cluster Mission

NASA Technical Reports Server (NTRS)

Kivelson, Margaret; Khurana, Krishan; Acuna, Mario (Technical Monitor)

2002-01-01

Prof M. G. Kivelson and Dr. K. K. Khurana (UCLA (University of California, Los Angeles)) are co-investigators on the Cluster Magnetometer Consortium (CMC) that provided the fluxgate magnetometers and associated mission support for the Cluster Mission. The CMC designated UCLA as the site with primary responsibility for the inter-calibration of data from the four spacecraft and the production of fully corrected data critical to achieving the mission objectives. UCLA will also participate in the analysis and interpretation of the data. The UCLA group here reports its excellent progress in developing fully intra-calibrated data for large portions of the mission and an excellent start in developing inter-calibrated data for selected time intervals, especially extended intervals in August, 2001 on which a workshop held at ESTEC in March, 2002 focused. In addition, some scientific investigations were initiated and results were reported at meetings.

A temporal discriminability account of children's eyewitness suggestibility.

PubMed

Bright-Paul, Alexandra; Jarrold, Christopher

2009-07-01

Children's suggestibility is typically measured using a three-stage 'event-misinformation-test' procedure. We examined whether suggestibility is influenced by the time delays imposed between these stages, and in particular whether the temporal discriminability of sources (event and misinformation) predicts performance. In a novel approach, the degree of source discriminability was calculated as the relative magnitude of two intervals (the ratio of event-misinformation and misinformation-test intervals), based on an adaptation of existing 'ratio-rule' accounts of memory. Five-year-olds (n =150) watched an event, and were exposed to misinformation, before memory for source was tested. The absolute event-test delay (12 versus 24 days) and the 'ratio' of event-misinformation/misinformation-test intervals (11:1, 3:1, 1:1, 1:3 and 1:11) were manipulated across participants. The temporal discriminability of sources, measured by the ratio, was indeed a strong predictor of suggestibility. Most importantly, if the ratio was constant (e.g. 18/6 versus 9/3 days), performance was remarkably similar despite variations in absolute delay (e.g. 24 versus 12 days). This intriguing finding not only extends the ratio-rule of distinctiveness to misinformation paradigms, but also serves to illustrate a new empirical means of differentiating between explanations of suggestibility based on interference between sources and disintegration of source information over time.

Time manages interference in visual short-term memory.

PubMed

Smith, Amy V; McKeown, Denis; Bunce, David

2017-09-01

Emerging evidence suggests that age-related declines in memory may reflect a failure in pattern separation, a process that is believed to reduce the encoding overlap between similar stimulus representations during memory encoding. Indeed, behavioural pattern separation may be indexed by a visual continuous recognition task in which items are presented in sequence and observers report for each whether it is novel, previously viewed (old), or whether it shares features with a previously viewed item (similar). In comparison to young adults, older adults show a decreased pattern separation when the number of items between "old" and "similar" items is increased. Yet the mechanisms of forgetting underpinning this type of recognition task are yet to be explored in a cognitively homogenous group, with careful control over the parameters of the task, including elapsing time (a critical variable in models of forgetting). By extending the inter-item intervals, number of intervening items and overall decay interval, we observed in a young adult sample (N = 35, M age  = 19.56 years) that the critical factor governing performance was inter-item interval. We argue that tasks using behavioural continuous recognition to index pattern separation in immediate memory will benefit from generous inter-item spacing, offering protection from inter-item interference.

Extended anticoagulation with apixaban reduces hospitalisations in patients with venous thromboembolism. An analysis of the AMPLIFY-EXT trial.

PubMed

Liu, Xianchen; Thompson, John; Phatak, Hemant; Mardekian, Jack; Porcari, Anthony; Johnson, Margot; Cohen, Alexander T

2016-01-01

Treatment with apixaban versus placebo for 12 months significantly reduced symptomatic recurrent venous thromboembolism (VTE) or all-cause death without increasing the rate of major bleeding in the AMPLIFY-EXT trial. This analysis examined the effects of apixaban versus placebo on the rate of all-cause hospitalisations, time to first hospitalisation, and predictors of first hospitalisation in patients with VTE enrolled in AMPLIFY-EXT. Treatment with apixaban 2.5 mg and 5 mg twice daily significantly reduced the rate of all-cause hospitalisations versus placebo (hazard ratio [95% confidence interval], 0.64 [0.43, 0.95]; p=0.026 and 0.54 [0.36, 0.82]; p=0.004, respectively). Apixaban prolonged mean time to first hospitalisation versus placebo by 43 and 49 days for the 2.5-mg and 5-mg twice-daily groups, respectively. Median length of hospital stay during the first hospitalisation was longer for placebo than for apixaban 2.5 mg or 5 mg twice daily (7.0, 5.0, and 4.5 days, respectively). Treatment with apixaban was a significant predictor of lower rates of hospitalisations versus placebo, and severe/moderate renal impairment was a significant predictor of an increased rate. This study supports extended use of apixaban for reducing all-cause hospitalisations and extending time to first hospitalisation in patients with VTE enrolled in AMPLIFY-EXT (www.clinicaltrials.gov registration: #NCT00633893).

Extended recency effect extended: blocking, presentation mode, and retention interval.

PubMed

Glidden, L M; Pawelski, C; Mar, H; Zigman, W

1979-07-01

The effect of blocking of stimulus items on the free recall of EMR adolescents was examined. In Experiment 1 a multitrial free-recall list of 15 pictures was presented either simultaneously in groups of 3, or sequentially, one at a time. Consistent ordering was used in both conditions, so that on each trial, each item in each set of 3 pictures was presented contiguously with the other 2 items from that set. In addition, recall came immediately or after a filled or unfilled delay of 24.5 seconds. Results showed that simultaneous presentation led to higher recall, subjective organization, and clustering than did sequential presentation, but analysis of serial-position curves showed a much reduced extended recency effect in comparison with previous studies. Experiment 2 was designed to determine whether the cause of the reduced extended recency was the use of pictures rather than words as stimuli. Stimuli were presented either as pictures, as pictures with auditory labels, or as words with auditory labels, with both simultaneous and consistent ordering for all conditions. Results indicated a strong extended recency effect for all groups, eliminating presentation mode as a causal factor in the data of Experiment 1. We concluded that blocking leads to increased organization and recall over a variety of presentation modes, rates, and block sizes.

Technical note: GODESS - a profiling mooring in the Gotland Basin

NASA Astrophysics Data System (ADS)

Prien, Ralf D.; Schulz-Bull, Detlef E.

2016-07-01

This note describes a profiling mooring with an interdisciplinary suite of sensors taking profiles between 180 and 30 m depth. It consists of an underwater winch, moored below 180 m depth, and a profiling instrumentation platform. In its described setup it can take about 200 profiles at pre-programmed times or intervals with one set of batteries. This allows for studies over an extended period of time (e.g. two daily profiles over a time of 3 months). The Gotland Deep Environmental Sampling Station (GODESS) in the Eastern Gotland Basin of the Baltic Sea is aimed at investigations of redoxcline dynamics. The described system can be readily adapted to other research foci by changing the profiling instrumentation platform and its payload.

Stochastic flux analysis of chemical reaction networks

PubMed Central

2013-01-01

Background Chemical reaction networks provide an abstraction scheme for a broad range of models in biology and ecology. The two common means for simulating these networks are the deterministic and the stochastic approaches. The traditional deterministic approach, based on differential equations, enjoys a rich set of analysis techniques, including a treatment of reaction fluxes. However, the discrete stochastic simulations, which provide advantages in some cases, lack a quantitative treatment of network fluxes. Results We describe a method for flux analysis of chemical reaction networks, where flux is given by the flow of species between reactions in stochastic simulations of the network. Extending discrete event simulation algorithms, our method constructs several data structures, and thereby reveals a variety of statistics about resource creation and consumption during the simulation. We use these structures to quantify the causal interdependence and relative importance of the reactions at arbitrary time intervals with respect to the network fluxes. This allows us to construct reduced networks that have the same flux-behavior, and compare these networks, also with respect to their time series. We demonstrate our approach on an extended example based on a published ODE model of the same network, that is, Rho GTP-binding proteins, and on other models from biology and ecology. Conclusions We provide a fully stochastic treatment of flux analysis. As in deterministic analysis, our method delivers the network behavior in terms of species transformations. Moreover, our stochastic analysis can be applied, not only at steady state, but at arbitrary time intervals, and used to identify the flow of specific species between specific reactions. Our cases study of Rho GTP-binding proteins reveals the role played by the cyclic reverse fluxes in tuning the behavior of this network. PMID:24314153

Stochastic flux analysis of chemical reaction networks.

PubMed

Kahramanoğulları, Ozan; Lynch, James F

2013-12-07

Chemical reaction networks provide an abstraction scheme for a broad range of models in biology and ecology. The two common means for simulating these networks are the deterministic and the stochastic approaches. The traditional deterministic approach, based on differential equations, enjoys a rich set of analysis techniques, including a treatment of reaction fluxes. However, the discrete stochastic simulations, which provide advantages in some cases, lack a quantitative treatment of network fluxes. We describe a method for flux analysis of chemical reaction networks, where flux is given by the flow of species between reactions in stochastic simulations of the network. Extending discrete event simulation algorithms, our method constructs several data structures, and thereby reveals a variety of statistics about resource creation and consumption during the simulation. We use these structures to quantify the causal interdependence and relative importance of the reactions at arbitrary time intervals with respect to the network fluxes. This allows us to construct reduced networks that have the same flux-behavior, and compare these networks, also with respect to their time series. We demonstrate our approach on an extended example based on a published ODE model of the same network, that is, Rho GTP-binding proteins, and on other models from biology and ecology. We provide a fully stochastic treatment of flux analysis. As in deterministic analysis, our method delivers the network behavior in terms of species transformations. Moreover, our stochastic analysis can be applied, not only at steady state, but at arbitrary time intervals, and used to identify the flow of specific species between specific reactions. Our cases study of Rho GTP-binding proteins reveals the role played by the cyclic reverse fluxes in tuning the behavior of this network.

Vaccination against pandemic influenza A/H1N1v in England: a real-time economic evaluation.

PubMed

Baguelin, Marc; Hoek, Albert Jan Van; Jit, Mark; Flasche, Stefan; White, Peter J; Edmunds, W John

2010-03-11

Decisions on how to mitigate an evolving pandemic are technically challenging. We present a real-time assessment of the effectiveness and cost-effectiveness of alternative influenza A/H1N1v vaccination strategies. A transmission dynamic model was fitted to the estimated number of cases in real-time, and used to generate plausible autumn scenarios under different vaccination options. The proportion of these cases by age and risk group leading to primary care consultations, National Pandemic Flu Service consultations, emergency attendances, hospitalisations, intensive care and death was then estimated using existing data from the pandemic. The real-time model suggests that the epidemic will peak in early November, with the peak height being similar in magnitude to the summer wave. Vaccination of the high-risk groups is estimated to prevent about 45 deaths (80% credibility interval 26-67), and save around 2900 QALYs (80% credibility interval 1600-4500). Such a programme is very likely to be cost-effective if the cost of vaccine purchase itself is treated as a sunk cost. Extending vaccination to low-risk individuals is expected to result in more modest gains in deaths and QALYs averted. Extending vaccination to school-age children would be the most cost-effective extension. The early availability of vaccines is crucial in determining the impact of such extensions. There have been a considerable number of cases of H1N1v in England, and so the benefits of vaccination to mitigate the ongoing autumn wave are limited. However, certain groups appear to be at significantly higher risk of complications and deaths, and so it appears both effective and cost-effective to vaccinate them. The United Kingdom was the first country to have a major epidemic in Europe. In countries where the epidemic is not so far advanced vaccination of children may be cost-effective. Similar, detailed, real-time modelling and economic studies could help to clarify the situation.

The extended atmosphere of Lambda Pavonis at the time of the emergence of H-emissions from minimum intensity

NASA Technical Reports Server (NTRS)

Sahade, Jorge; Rovira, Marta; Ringuelet, Adela E.; Kondo, Yoji; Cidale, Lydia

1988-01-01

A study of the Be star Lambda Pavonis, particularly of the changes in the Balmer discontinuity in the interval 1949-1982, is presented. Nearly simultaneous observations carried out with the ESO 1.5 m reflector at La Silla and with the IUE satellite correspond to an epoch when the H emission is starting to increase intensity immediately after having reached its minimum strength. These observations suggest the presence of four distinct regions of line formation, with the material moving outward in the transition region.

A supplemental catalog of atmospheric densities from satellite-drag analysis

NASA Technical Reports Server (NTRS)

Jacchia, L. G.; Slowey, J. W.

1972-01-01

The catalog of densities derived from satellite-drag analysis extends and supplements similar earlier publications. The densities were computed from nine artificial satellites for effective heights ranging from 300 to 1130 km, and are presented together with pertinent data that permit the location in time and space of the point to which they refer. The intervals covered vary between 1 and 6 years for the different satellites and average about 3.5 years for the nine satellites. The cutoff date for the data included is, in most cases, January 14, 1970.

New advances in the partial-reflection-drifts experiment using microprocessors

NASA Technical Reports Server (NTRS)

Ruggerio, R. L.; Bowhill, S. A.

1982-01-01

Improvements to the partial reflection drifts experiment are completed. The results of the improvements include real time processing and simultaneous measurements of the D region with coherent scatter. Preliminary results indicate a positive correlation between drift velocities calculated by both methods during a two day interval. The possibility now exists for extended observations between partial reflection and coherent scatter. In addition, preliminary measurements could be performed between partial reflection and meteor radar to complete a comparison of methods used to determine velocities in the D region.

Neck Fatigue and Comfort Effects Due to the Extended Wear of Law Enforcement Representative Head-Borne Personal Protective Equipment

DTIC Science & Technology

2010-12-01

Ache - Head by Configuration 42 31. Pain and Ache - Head by Time x Gender Interaction 43 32. Pain and Ache - Neck by Hour 43 33. Pain...and Ache - Upper/Middle Back by Hour 44 34. Pain and Ache - Lower Back by Hour 45 35. Numbness or Loss of Sensation - Head by Hour 45 36. Numbness...gender). Pain and Ache - Head (Vertical bars denote 0 90 confidence intervals) Figure 30. Pain and Ache - Head by Configuration In this

Excessive work and risk of haemorrhagic stroke: a nationwide case-control study.

PubMed

Kim, Beom Joon; Lee, Seung-Hoon; Ryu, Wi-Sun; Kim, Chi Kyung; Chung, Jong-Won; Kim, Dohoung; Park, Hong-Kyun; Bae, Hee-Joon; Park, Byung-Joo; Yoon, Byung-Woo

2013-10-01

Adverse effect of excessive work on health has been suggested previously, but it was not documented in cerebrovascular diseases. The authors investigated whether excessive working conditions would associate with increased risk of haemorrhagic stroke. A nationwide matched case-control study database, which contains 940 cases of incident haemorrhagic stroke (498 intracerebral haemorrhages and 442 sub-arachnoid haemorrhages) with 1880 gender- and age- (± 5-year) matched controls, was analysed. Work-related information based on the regular job situation, including type of occupation, regular working time, duration of strenuous activity during regular work and shift work, was gathered through face-to-face interviews. Conditional logistic regression analyses were used for the multivariable analyses. Compared with white-collar workers, blue-collar workers had a higher risk for haemorrhagic stroke (odds ratio, 1.33 [95% confidence interval, 1.06-1.66]). Longer regular working time was associated with increased risk of haemorrhagic stroke [odds ratio, 1.38 (95% confidence interval, 1.05-1.81) for 8-12 h/day; odds ratio, 1.95 (95% confidence interval, 1.33-2.86) for ≥ 13 h/day; compared with ≤ 4 h/day]. Exposure to ≥ 8 h/week of strenuous activity also associated haemorrhagic stroke risk [odds ratio, 1.61 (95% confidence interval, 1.26-2.05); compared with no strenuous activity]. Shift work was not associated with haemorrhagic stroke (P = 0.98). Positive associations between working condition indices and haemorrhagic stroke risk were consistent regardless of haemorrhagic stroke sub-types and current employment status. Blue-collar occupation, longer regular working time and extended duration of strenuous activity during work may relate to an increased risk of haemorrhagic stroke. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Oral health of schoolchildren in Western Australia.

PubMed

Arrow, P

2016-09-01

The West Australian School Dental Service (SDS) provides free, statewide, primary dental care to schoolchildren aged 5-17 years. This study reports on an evaluation of the oral health of children examined during the 2014 calendar year. Children were sampled, based on their date of birth, and SDS clinicians collected the clinical information. Weighted mean values of caries experience were presented. Negative binomial regression modelling was undertaken to test for factors of significance in the rate of caries occurrence. Data from children aged 5-15 years were used (girls = 4616, boys = 4900). Mean dmft (5-10-year-olds), 1.42 SE 0.03; mean DMFT (6-15-year-olds), 0.51 SE 0.01. Negative binomial regression model of permanent tooth caries found higher rates of caries in children who were from non-fluoridated areas (RR 2.1); Aboriginal (RR 2.4); had gingival inflammation (RR 1.5); lower ICSEA level (RR 1.4); and recalled at more than 24-month interval (RR 1.8). The study highlighted poor dental health associated with living in non-fluoridated areas, Aboriginal identity, poor oral hygiene, lower socioeconomic level and having extended intervals between dental checkups. Timely assessments and preventive measures targeted at groups, including extending community water fluoridation, may assist in further improving the oral health of children in Western Australia. © 2015 Australian Dental Association.

A study comparing changes in loading conditions of an extended service life system using aluminum 2024-T351

NASA Astrophysics Data System (ADS)

Beal, Roger Zack

The current fiscally austere environment prevalent in the military and industry is driving extreme measures to save money. In the United States Air Force, this has driven enormous efforts to trim sustainment spending on extended life aircraft. The challenge to the aerospace engineer is to ensure flight safety in the midst of this economic pressure. One method of cutting costs is to increase the time an aircraft is in service by delaying the point when the aircraft is taken out of service for depot maintenance. To ensure flight safety, in depth fatigue and fracture analysis needs to be accomplished to assess increasing the inspection interval. The purpose of this study was to determine the sensitivity of Aluminum 2024-T351 alloy, a common material used in tension dominated aerospace applications, to two different loading spectra---one that is aggressive and the other that is benign. This was accomplished by conducting five different combinations of the two spectra, developing computer simulations using the AFGROW software and comparing with the measured data. The results showed that the material demonstrated significantly different behavior between the two spectra. These results provide a valuable tool for the aerospace engineer for fatigue life prediction and inspection interval evaluation.

In Vitro Emergence of High Persistence upon Periodic Aminoglycoside Challenge in the ESKAPE Pathogens

PubMed Central

Verstraeten, Natalie; Fauvart, Maarten

2016-01-01

Health care-associated infections present a major threat to modern medical care. Six worrisome nosocomial pathogens—Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.—are collectively referred to as the “ESKAPE bugs.” They are notorious for extensive multidrug resistance, yet persistence, or the phenotypic tolerance displayed by a variant subpopulation, remains underappreciated in these pathogens. Importantly, persistence can prevent eradication of antibiotic-sensitive bacterial populations and is thought to act as a catalyst for the development of genetic resistance. Concentration- and time-dependent aminoglycoside killing experiments were used to investigate persistence in the ESKAPE pathogens. Additionally, a recently developed method for the experimental evolution of persistence was employed to investigate adaptation to high-dose, extended-interval aminoglycoside therapy in vitro. We show that ESKAPE pathogens exhibit biphasic killing kinetics, indicative of persister formation. In vitro cycling between aminoglycoside killing and persister cell regrowth, evocative of clinical high-dose extended-interval therapy, caused a 37- to 213-fold increase in persistence without the emergence of resistance. Increased persistence also manifested in biofilms and provided cross-tolerance to different clinically important antibiotics. Together, our results highlight a possible drawback of intermittent, high-dose antibiotic therapy and suggest that clinical diagnostics might benefit from taking into account persistence. PMID:27185802

Variations on a theme by chopin: relations between perception and production of timing in music.

PubMed

Repp, B H

1998-06-01

A note interonset interval (IOI) increment in mechanically timed music is more difficult to detect where expressive lengthening typically occurs in artistic performance. Experiment 1 showed this in an excerpt from a Chopin etude and extended the task to IOI decrement detection. A simple measure of variation in perceptual bias was derived that correlated highly with the average timing pattern of pianists' performances, more so than with acoustic surface properties of the music. Similar results, but decreasing correlations, were obtained in each of four subsequent experiments in which the music was simplified in stages. Although local psychoacoustic effects on time perception cannot be ruled out completely, the results suggest that musical structure (melodic-rhythmic grouping in particular) has temporal implications that are reflected not only in musicians' motor behavior but also in listeners' time-keeping abilities.

The stratigraphic record of recent climate change in mid-Atlantic USA

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

Brush, G.S.; Hilgartner, W.B.; Khan, H.

1994-06-01

The Medieval Warm Period and Little Ice Age recorded in sediments deposited in tributaries and marshes surrounding the Chesapeake and Delaware Bays in the mid-Atlantic region of USA, by changes in pollen and seeds of terrestrial and aquatic plants, and changes in influxes of charcoal, sediment, metals and nutrients. Fossil pollen and seeds portray a regional landscape characterized by conditions drier that present from about 1000 to 1200 AD. During the same period, high charcoal and sediment influxes indicate high fire frequency. This short dry interval was followed by an expansion of submerged aquatic plants, low marsh plants, and terrestrialmore » plants that occupy wet habitats. Charcoal influxes are extremely low during the latter interval, which extended from about 1200 AD to 1500 AD. Plant macrofossil and pollen distributions indicate a second dry period extending from 1550 to 1650 AD, which appears similar to the earlier Medieval Warm interval.« less

Simplifying anemia management in hemodialysis patients: ESAs administered at longer dosing intervals can enhance opportunities to provide patient-focused care.

PubMed

Schiller, Brigitte; Besarab, Anatole

2011-08-01

To review issues and challenges in caring for hemodialysis patients with anemia of chronic kidney disease, specifically focusing on the effects of longer erythropoiesis-stimulating agent (ESA) dosing intervals on processes of care. PubMed searches were performed limited to the last 10 years to February 2011, focusing on articles in English that were 'clinical trials,' assessed processes of care, measured associations of hemoglobin (Hb) with outcomes, and explored/analyzed extended dosing intervals of ESAs in hemodialysis patients and recommendations for increasing the quality of care of these patients. Some limitations included the fact that a meta-analysis was not conducted; many studies were associative and therefore unable to prove causality; and none of the clinical trials directly compared the impact of more frequent or less frequent ESA dosing strategies on patient care and outcomes. Progress over the past several decades has been substantial; however, unmet needs remain and there is room for improvement in efficiencies of care. Many patients fail to meet Hb targets, and nephrology professionals' time is consumed with preparing, administering, and monitoring therapy. Direct interaction between patients and care providers has been lost as attention has shifted to 'cost-effective' (not necessarily patient-centered) ways to deliver care. Use of ESAs at longer dosage intervals represents one opportunity to improve efficiency of care. Newer ESAs have been developed for less frequent dosing. Once-monthly dosing decreases time spent administering/monitoring therapy and allows nephrology professionals to provide comprehensive renal care, wherein the patient rather than task-oriented processes becomes the primary focus. A fragmented, uncoordinated care-delivery model heightens the urgency to systematically address issues related to delivery of care and improve efficiencies in anemia management as part of the patient-centered approach. ESAs designed for administration at longer intervals may effectively and reliably achieve Hb targets with once-monthly dosing, thereby decreasing time spent administering/monitoring therapy.

Recording and automated analysis of naturalistic bioptic driving.

PubMed

Luo, Gang; Peli, Eli

2011-05-01

People with moderate central vision loss are legally permitted to drive with a bioptic telescope in 39 US states and the Netherlands, but the safety of bioptic driving remains highly controversial. There is no scientific evidence about bioptic use and its impact on safety. We propose searching for evidence by recording naturalistic driving activities in patients' cars. In a pilot study we used an analogue video system to record two bioptic drivers' daily driving activities for 10 and 5 days, respectively. In this technical report, we also describe our novel digital system that collects vehicle manoeuvre information and enables recording over more extended periods, and discuss our approach to analyzing the vast amount of data. Our observations of telescope use by the pilot subjects were quite different from their reports in a previous survey. One subject used the telescope only seven times in nearly 6 h of driving. For the other subject, the average interval between telescope use was about 2 min, and Mobile (cell) phone use in one trip extended the interval to almost 5 min. We demonstrate that computerized analysis of lengthy recordings based on video, GPS, acceleration, and black box data can be used to select informative segments for efficient off-line review of naturalistic driving behaviours. The inconsistency between self reports and objective data as well as infrequent telescope use underscores the importance of recording bioptic driving behaviours in naturalistic conditions over extended periods. We argue that the new recording system is important for understanding bioptic use behaviours and bioptic driving safety. © 2011 The College of Optometrists.

Recording and automated analysis of naturalistic bioptic driving

PubMed Central

Luo, Gang; Peli, Eli

2011-01-01

Purpose People with moderate central vision loss are legally permitted to drive with a bioptic telescope in 39 US states and the Netherlands, but the safety of bioptic driving remains highly controversial. There is no scientific evidence about bioptic use and its impact on safety. We propose searching for evidence by recording naturalistic driving activities in patients' cars. Methods In a pilot study we used an analogue video system to record two bioptic drivers' daily driving activities for 10 and 5 days, respectively. In this technical report, we also describe our novel digital system that collects vehicle maneuver information and enables recording over more extended periods, and discuss our approach to analyzing the vast amount of data. Results Our observations of telescope use by the pilot subjects were quite different from their reports in a previous survey. One subject used the telescope only 7 times in nearly 6 hours of driving. For the other subject, the average interval between telescope use was about 2 minutes, and cell phone use in one trip extended the interval to almost 5 minutes. We demonstrate that computerized analysis of lengthy recordings based on video, GPS, acceleration, and black box data can be used to select informative segments for efficient off-line review of naturalistic driving behaviors. Conclusions The inconsistency between self reports and objective data as well as infrequent telescope use underscores the importance of recording bioptic driving behaviors in naturalistic conditions over extended periods. We argue that the new recording system is important for understanding bioptic use behaviors and bioptic driving safety. PMID:21410498

Fix and Sample with Rats in the Dynamics of Choice

ERIC Educational Resources Information Center

Aparicio, Carlos F.; Baum, William M.

2006-01-01

The generality of the molar view of behavior was extended to the study of choice with rats, showing the usefulness of studying order at various levels of extendedness. Rats' presses on two levers produced food according to concurrent variable-interval variable-interval schedules. Seven different reinforcer ratios were arranged within each session,…

GCM Simulations of Neoproterozoic "Snowball Earth" Conditions: Implications for the Environmental Limits on Terrestrial Metazoans and Their Extraterrestrial Analogues

NASA Technical Reports Server (NTRS)

Sohl, L. E.; Chandler, M. A.

2001-01-01

The Neoproterozoic Snowball Earth intervals provide excellent opportunities to examine the environmental limits on terrestrial metazoans. A series of GCM simulations was run in order to quantify climatic conditions during these intervals. Additional information is contained in the original extended abstract.

Gravity and Neuronal Adaptation. Neurophysiology of Reflexes from Hypo- to Hypergravity Conditions

NASA Astrophysics Data System (ADS)

Ritzmann, Ramona; Krause, Anne; Freyler, Kathrin; Gollhofer, Albert

2017-02-01

Introduction: For interplanetary and orbital missions in human space flight, knowledge about the gravity-sensitivity of the central nervous system (CNS) is required. The objective of this study was to assess neurophysiological correlates in variable hetero gravity conditions in regard to their timing and shaping. Methods: In ten subjects, peripheral nerve stimulation was used to elicit H-reflexes and M-waves in the M. soleus in Lunar, Martian, Earth and hypergravity. Gravity-dependencies were described by means of reflex latency, inter-peak-interval, duration, stimulation threshold and maximal amplitudes. Experiments were executed during the CNES/ESA/DLR JEPPFs. Results: H-reflex latency, inter-peak-interval and duration decreased with increasing gravitation (P<0.05); likewise, M-wave inter-peak-interval was diminished and latency prolonged with increasing gravity (P<0.05). Stimulation threshold of H-reflexes and M-waves decreased (P<0.05) while maximal amplitudes increased with an increase in gravitation (P<0.05). Conclusion: Adaptations in neurophysiological correlates in hetero gravity are associated with a shift in timing and shaping. For the first time, our results indicate that synaptic and axonal nerve conduction velocity as well as axonal and spinal excitability are diminished with reduced gravitational forces on the Moon and Mars and gradually increased when gravitation is progressively augmented up to hypergravity. Interrelated with the adaptation in threshold we conclude that neuronal circuitries are significantly affected by gravitation. As a consequence, movement control and countermeasures may be biased in extended space missions involving transitions between different force environments.

Extended Task Space Control for Robotic Manipulators

NASA Technical Reports Server (NTRS)

Backes, Paul G. (Inventor); Long, Mark K. (Inventor)

1996-01-01

The invention is a method of operating a robot in successive sampling intervals to perform a task, the robot having joints and joint actuators with actuator control loops, by decomposing the task into behavior forces, accelerations, velocities and positions of plural behaviors to be exhibited by the robot simultaneously, computing actuator accelerations of the joint actuators for the current sampling interval from both behavior forces, accelerations velocities and positions of the current sampling interval and actuator velocities and positions of the previous sampling interval, computing actuator velocities and positions of the joint actuators for the current sampling interval from the actuator velocities and positions of the previous sampling interval, and, finally, controlling the actuators in accordance with the actuator accelerations, velocities and positions of the current sampling interval. The actuator accelerations, velocities and positions of the current sampling interval are stored for use during the next sampling interval.

Extended opening hours and patient experience of general practice in England: multilevel regression analysis of a national patient survey

PubMed Central

Cowling, Thomas E; Harris, Matthew; Majeed, Azeem

2017-01-01

Background The UK government plans to extend the opening hours of general practices in England. The ‘extended hours access scheme’ pays practices for providing appointments outside core times (08:00 to 18.30, Monday to Friday) for at least 30 min per 1000 registered patients each week. Objective To determine the association between extended hours access scheme participation and patient experience. Methods Retrospective analysis of a national cross-sectional survey completed by questionnaire (General Practice Patient Survey 2013–2014); 903 357 survey respondents aged ≥18 years old and registered to 8005 general practices formed the study population. Outcome measures were satisfaction with opening hours, experience of making an appointment and overall experience (on five-level interval scales from 0 to 100). Mean differences between scheme participation groups were estimated using multilevel random-effects regression, propensity score matching and instrumental variable analysis. Results Most patients were very (37.2%) or fairly satisfied (42.7%) with the opening hours of their general practices; results were similar for experience of making an appointment and overall experience. Most general practices participated in the extended hours access scheme (73.9%). Mean differences in outcome measures between scheme participants and non-participants were positive but small across estimation methods (mean differences ≤1.79). For example, scheme participation was associated with a 1.25 (95% CI 0.96 to 1.55) increase in satisfaction with opening hours using multilevel regression; this association was slightly greater when patients could not take time off work to see a general practitioner (2.08, 95% CI 1.53 to 2.63). Conclusions Participation in the extended hours access scheme has a limited association with three patient experience measures. This questions expected impacts of current plans to extend opening hours on patient experience. PMID:27343274

Extended opening hours and patient experience of general practice in England: multilevel regression analysis of a national patient survey.

PubMed

Cowling, Thomas E; Harris, Matthew; Majeed, Azeem

2017-05-01

The UK government plans to extend the opening hours of general practices in England. The 'extended hours access scheme' pays practices for providing appointments outside core times (08:00 to 18.30, Monday to Friday) for at least 30 min per 1000 registered patients each week. To determine the association between extended hours access scheme participation and patient experience. Retrospective analysis of a national cross-sectional survey completed by questionnaire (General Practice Patient Survey 2013-2014); 903 357 survey respondents aged ≥18 years old and registered to 8005 general practices formed the study population. Outcome measures were satisfaction with opening hours, experience of making an appointment and overall experience (on five-level interval scales from 0 to 100). Mean differences between scheme participation groups were estimated using multilevel random-effects regression, propensity score matching and instrumental variable analysis. Most patients were very (37.2%) or fairly satisfied (42.7%) with the opening hours of their general practices; results were similar for experience of making an appointment and overall experience. Most general practices participated in the extended hours access scheme (73.9%). Mean differences in outcome measures between scheme participants and non-participants were positive but small across estimation methods (mean differences ≤1.79). For example, scheme participation was associated with a 1.25 (95% CI 0.96 to 1.55) increase in satisfaction with opening hours using multilevel regression; this association was slightly greater when patients could not take time off work to see a general practitioner (2.08, 95% CI 1.53 to 2.63). Participation in the extended hours access scheme has a limited association with three patient experience measures. This questions expected impacts of current plans to extend opening hours on patient experience. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

The Whole Heliosphere Interval: Campaign Summaries and Early Results

NASA Technical Reports Server (NTRS)

Thompson, Barbara J.; Gibson, Sarah E.; Kozyra, Janet U.

2008-01-01

The Whole Heliosphere Interval (WHI) is an internationally coordinated observing and modeling effort to characterize the 3-dimensional interconnected solar-heliospheric-planetary system - a.k.a. the "heliophysical" system. The heart of the WHI campaign is the study of the interconnected 3-D heliophysical domain, from the interior of the Sun, to the Earth, outer planets, and into interstellar space. WHI observing campaigns began with the 3-0 solar structure from solar Carrington Rotation 2068, which ran from March 20 - April 16, 2008. Observations and models of the outer heliosphere and planetary impacts extended beyond those dates as necessary; for example, the solar wind transit time to outer planets can take months. WHI occurs during solar minimum, which optimizes our ability to characterize the 3-D heliosphere and trace the structure to the outer limits of the heliosphere. A summary of some of the key results from the WHI first workshop in August 2008 will be given.

Aflibercept in wet AMD beyond the first year of treatment: recommendations by an expert roundtable panel

PubMed Central

McKibbin, M; Devonport, H; Gale, R; Gavin, M; Lotery, A; Mahmood, S; Patel, P J; Ross, A; Sivaprasad, S; Talks, J; Walters, G

2015-01-01

This supplement has been sponsored by Bayer HealthCare. Please see acknowledgements for full disclaimer. Prescribing Information can be found in the appendices. L.GB.COM.05.2015.11280. Date of preparation: June 2015 This paper provides expert recommendations on administration of aflibercept in wet age-related macular degeneration (AMD) after Year 1 (Y1), based on a roundtable discussion held in London, UK in November 2014. The goals of treatment after Y1 are to maintain visual and anatomical gains whilst minimising treatment burden and using resources effectively. The treatment decision should be made at the seventh injection visit (assuming the label has been followed) in Y1, and three approaches are proposed: (a) eyes with active disease on imaging/examination but with stable visual acuity (VA) at the end of Y1 should continue with fixed 8-weekly dosing; (b) eyes with inactive disease on imaging/examination and stable VA should be managed using a ‘treat and extend' (T&E) regimen. T&E involves treating and then extending the interval until the next treatment, by 2-week intervals, to a maximum of 12 weeks, provided the disease remains inactive. If there is new evidence of disease activity, treatment is administered and the interval to the next treatment shortened; and (c) if there has been no disease activity for ≥3 consecutive visits, a trial of monitoring without treatment may be appropriate, initiated at the end of Y1 or at any time during Y2. Where possible, VA testing, OCT imaging and injection should be performed at the same visit. The second eye should be monitored to detect fellow eye involvement. In bilateral disease, the re-treatment interval should be driven by the better-seeing eye or, if the VA is similar, the eye with the more active disease. PMID:26156564

Cardiovascular System Sonographic Evaluation Algorithm: A New Sonographic Algorithm for Evaluation of the Fetal Cardiovascular System in the Second Trimester.

PubMed

De León-Luis, Juan; Bravo, Coral; Gámez, Francisco; Ortiz-Quintana, Luis

2015-07-01

To evaluate the reproducibility and feasibility of the new cardiovascular system sonographic evaluation algorithm for studying the extended fetal cardiovascular system, including the portal, thymic, and supra-aortic areas, in the second trimester of pregnancy (19-22 weeks). We performed a cross-sectional study of pregnant women with healthy fetuses (singleton and twin pregnancies) attending our center from March to August 2011. The extended fetal cardiovascular system was evaluated by following the new algorithm, a sequential acquisition of axial views comprising the following (caudal to cranial): I, portal sinus; II, ductus venosus; III, hepatic veins; IV, 4-chamber view; V, left ventricular outflow tract; VI, right ventricular outflow tract; VII, 3-vessel and trachea view; VIII, thy-box; and IX, subclavian arteries. Interobserver agreement on the feasibility and exploration time was estimated in a subgroup of patients. The feasibility and exploration time were determined for the main cohort. Maternal, fetal, and sonographic factors affecting both features were evaluated. Interobserver agreement was excellent for all views except view VIII; the difference in the mean exploration time between observers was 1.5 minutes (95% confidence interval, 0.7-2.1 minutes; P < .05). In 184 fetuses (mean gestational age ± SD, 20 ± 0.6 weeks), the feasibility of all views was close to 99% except view VIII (88.7%). The complete feasibility of the algorithm was 81.5%. The mean exploration time was 5.6 ± 4.2 minutes. Only the occiput anterior fetal position was associated with a lower frequency of visualization and a longer exploration time (P < .05). The cardiovascular system sonographic evaluation algorithm is a reproducible and feasible approach for exploration of the extended fetal cardiovascular system in a second-trimester scan. It can be used to explore these areas in normal and abnormal conditions and provides an integrated image of extended fetal cardiovascular anatomy. © 2015 by the American Institute of Ultrasound in Medicine.

Migration and Extension of Solar Active Longitudinal Zones

NASA Astrophysics Data System (ADS)

Gyenge, N.; Baranyi, T.; Ludmány, A.

2014-02-01

Solar active longitudes show a characteristic migration pattern in the Carrington coordinate system if they can be identified at all. By following this migration, the longitudinal activity distribution around the center of the band can be determined. The half-width of the distribution is found to be varying in Cycles 21 - 23, and in some time intervals it was as narrow as 20 - 30 degrees. It was more extended around a maximum but it was also narrow when the activity jumped to the opposite longitude. Flux emergence exhibited a quasi-periodic variation within the active zone with a period of about 1.3 years. The path of the active-longitude migration does not support the view that it might be associated with the 11-year solar cycle. These results were obtained for a limited time interval of a few solar cycles and, bearing in mind uncertainties of the migration-path definition, are only indicative. For the major fraction of the dataset no systematic active longitudes were found. Sporadic migration of active longitudes was identified only for Cycles 21 - 22 in the northern hemisphere and Cycle 23 in the southern hemisphere.

Decay uncovered in nonverbal short-term memory.

PubMed

Mercer, Tom; McKeown, Denis

2014-02-01

Decay theory posits that memory traces gradually fade away over the passage of time unless they are actively rehearsed. Much recent work exploring verbal short-term memory has challenged this theory, but there does appear to be evidence for trace decay in nonverbal auditory short-term memory. Numerous discrimination studies have reported a performance decline as the interval separating two tones is increased, consistent with a decay process. However, most of this tone comparison research can be explained in other ways, without reference to decay, and these alternative accounts were tested in the present study. In Experiment 1, signals were employed toward the end of extended retention intervals to ensure that listeners were alert to the presence and frequency content of the memoranda. In Experiment 2, a mask stimulus was employed in an attempt to distinguish between a highly detailed sensory trace and a longer-lasting short-term memory, and the distinctiveness of the stimuli was varied. Despite these precautions, slow-acting trace decay was observed. It therefore appears that the mere passage of time can lead to forgetting in some forms of short-term memory.

Pharmacokinetics of an oral extended-release formulation of doxycycline hyclate containing acrylic acid and polymethacrylate in dogs.

PubMed

Ruiz, Sara Melisa Arciniegas; Olvera, Lilia Gutiérrez; Chacón, Sara del Carmen Caballero; Estrada, Dinorah Vargas

2015-04-01

To determine the pharmacokinetics of doxycycline hyclate administered orally in the form of experimental formulations with different proportions of acrylic acid-polymethacrylate-based matrices. 30 healthy adult dogs. In a crossover study, dogs were randomly assigned (in groups of 10) to receive a single oral dose (20 mg/kg) of doxycycline hyclate without excipients (control) or extended-release formulations (ERFs) containing doxycycline, acrylic acid polymer, and polymethacrylate in the following proportions: 1:0.5:0.0075 (ERF1) or 1:1:0.015 (ERF2). Serum concentrations of doxycycline were determined for pharmacokinetic analysis before and at several intervals after each treatment. Following oral administration to the study dogs, each ERF resulted in therapeutic serum doxycycline concentrations for 48 hours, whereas the control treatment resulted in therapeutic serum doxycycline concentrations for only 24 hours. All pharmacokinetic parameters for ERF1 and ERF2 were significantly different; however, findings for ERF1 did not differ significantly from those for the control treatment. Results indicated that both ERFs containing doxycycline, acrylic acid polymer, and polymethacrylate had an adequate pharmacokinetic-pharmacodynamic relationship for a time-dependent drug and a longer release time than doxycycline alone following oral administration in dogs. Given the minimum effective serum doxycycline concentration of 0.26 μg/mL, a dose interval of 48 hours can be achieved for each tested ERF. This minimum inhibitory concentration has the potential to be effective against several susceptible bacteria involved in important infections in dogs. Treatment of dogs with either ERF may have several benefits over treatment with doxycycline alone.

Changes in the Far UV Spectrum of Eta Carinae Near the 2003 Minimum

NASA Technical Reports Server (NTRS)

Iping, R. C.; Gull, T. R.; Sonneborn, G.; Massa, D.; Vieira, G. L.; Nielsen, K. E.

2004-01-01

High resolution 905-1180 spectra of \\eta Carinae have been obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite at nine epochs between February 2000 and June 2003 . This period of time extends from the broad maximum up to the very beginning of the minimum of the 5.52-year period initially discovered by A. Damineli. The flux levels were unchanged between February 2000 through February 2003 with minor spectral differences. The X-Ray minimum started on June 29, 2003 . Three observations were accomplished on June 10, June 17 and June 27 leading up to the minimum. Substantial changes were present in the June 10 and June 17 spectra, but a very significant change occurred by June 27, 2003. Longward of 1100A, the overall flux dropped 10 to 30 %. Shortward of 1100A, there are spectral intervals with NO decrease in flux even down to the shortest wavelengths (920--950 ). This indicates that dust absorption has a negligible role in the observed spectral changes and that line absorptions play a major role. Throughout the spectrum there are intervals ranging in width of 3-10A with strong increased absorption. Significant absorptions may be associated with the red portion of the following stellar wind lines: C III 977, O VI 1031,1037, P V 1117, while other absorption features are much broader, more extended and not clearly associated with well-known spectral transitions. Given the complexity of the STIS echelle spectra taken in this period of time, many of these absorption features are likely due to multiple absorption lines

a New Approach to Physiologic Triggering in Medical Imaging Using Multiple Heart Sounds Alone.

NASA Astrophysics Data System (ADS)

Groch, Mark Walter

A new method for physiological synchronization of medical image acquisition using both the first and second heart sound has been developed. Heart sounds gating (HSG) circuitry has been developed which identifies, individually, both the first (S1) and second (S2) heart sounds from their timing relationship alone, and provides two synchronization points during the cardiac cycle. Identification of first and second heart sounds from their timing relationship alone and application to medical imaging has, heretofore, not been performed in radiology or nuclear medicine. The heart sounds are obtained as conditioned analog signals from a piezoelectric transducer microphone placed on the patient's chest. The timing relationships between the S1 to S2 pulses and the S2 to S1 pulses are determined using a logic scheme capable of distinguishing the S1 and S2 pulses from the heart sounds themselves, using their timing relationships, and the assumption that initially the S1-S2 interval will be shorter than the S2-S1 interval. Digital logic circuitry is utilized to continually track the timing intervals and extend the S1/S2 identification to heart rates up to 200 beats per minute (where the S1-S2 interval is not shorter than the S2-S1 interval). Clinically, first heart sound gating may be performed to assess the systolic ejection portion of the cardiac cycle, with S2 gating utilized for reproduction of the diastolic filling portion of the cycle. One application of HSG used for physiologic synchronization is in multigated blood pool (MGBP) imaging in nuclear medicine. Heart sounds gating has been applied to twenty patients who underwent analysis of ventricular function in Nuclear Medicine, and compared to conventional ECG gated MGBP. Left ventricular ejection fractions calculated from MGBP studies using a S1 and a S2 heart sound trigger correlated well with conventional ECG gated acquisitions in patients adequately gated by HSG and ECG. Heart sounds gating provided superior definition of the diastolic filling phase of the cardiac cycle by qualitative assessment of the left ventricular volume time -activity curves. Heart sounds physiological synchronization has potential to be used in other imaging modalities, such as magnetic resonance imaging, where the ECG is distorted due to the electromagnetic environment within the imager.

An Extended Forecast of the Frequencies of North Atlantic Basin Tropical Cyclone Activity for 2009

NASA Technical Reports Server (NTRS)

Wilson, Robert M.

2009-01-01

An extended forecast of the frequencies for the 2009 North Atlantic basin hurricane season is presented. Continued increased activity during the 2009 season with numbers of tropical cyclones, hurricanes, and major hurricanes exceeding long-term averages are indicated. Poisson statistics for the combined high-activity intervals (1950-1965 and 1995-2008) give the central 50% intervals to be 9-14, 5-8, and 2-4, respectively, for the number of tropical cyclones, hurricanes, and major hurricanes, with a 23.4% chance of exceeding 14 tropical cyclones, a 28% chance of exceeding 8 hurricanes, and a 31.9% chance of exceeding 4 major hurricanes. Based strictly on the statistics of the current high-activity interval (1995-2008), the central 50% intervals for the numbers of tropical cyclones, hurricanes, and major hurricanes are 12-18, 6-10, and 3-5, respectively, with only a 5% chance of exceeding 23, 13, or 7 storms, respectively. Also examined are the first differences in 10-yr moving averages and the effects of global warming and decadal-length oscillations on the frequencies of occurrence for North Atlantic basin tropical cyclones. In particular, temperature now appears to be the principal driver of increased activity and storm strength during the current high-activity interval, with near-record values possible during the 2009 season.

Extended lowered body temperature increases the effective CS-US interval in conditioned taste aversion for adult rats.

PubMed

Hinderliter, Charles F; Goodhart, Mark; Anderson, Matthew J; Misanin, James R

2002-06-01

Assuming body temperature correlates with metabolic activities, rate of body temperature recovery was manipulated to assess effects on long-trace conditioning in a conditioned taste-aversion paradigm. Following 10 min. access to a .1% saccharin solution and then 10 min. immersion in 0-0.5 degrees C water, two groups of 16 Wistar-derived, 81-113 day-old, male albino rats received either saline or lithium chloride injections 3 hr. later. These two groups were subdivided on basis of warming rate during the 3-hr. interval. Half of the rats recovered at room temperature (20 degrees to 21 degrees C), and half recovered in an incubator maintained at 30 degrees C. Maintaining a lowered body temperature between the conditioned stimulus and unconditioned stimulus allowed an association to be made at 3 hr., an interval that normally does not support conditioning. In contrast, lowering body temperature and then inducing a fast warming rate did not produce evidence of an aversion. It is suggested that maintaining a low body temperature over the interval between the presentation of the conditioned stimulus and unconditioned stimulus slows a metabolic clock that extends the measured interval at which associations can be made using conditioned taste-aversion procedures.

Contraceptive efficacy and tolerability of ethinylestradiol 20 µg/drospirenone 3 mg in a flexible extended regimen: an open-label, multicentre, randomised, controlled study

PubMed Central

Klipping, Christine; Duijkers, Ingrid; Fortier, Michel P; Marr, Joachim; Trummer, Dietmar; Elliesen, Jörg

2012-01-01

Background The contraceptive efficacy and tolerability of a new flexible extended regimen of ethinylestradiol (EE) 20 μg/drospirenone (DRSP) 3 mg to extend the menstrual cycle and enable management of intracyclic (breakthrough) bleeding (flexibleMIB) was investigated and the bleeding pattern compared with a conventional 28-day regimen and a fixed extended 124-day regimen. Study design This Phase III, 2-year, multicentre, open-label study randomly (4:1:1) allocated women (aged 18–35 years) to the following regimens: flexibleMIB (24–120 days' active hormonal intake with 4-day tablet-free intervals); conventional (24 days' active hormonal intake followed by a 4-day hormone-free interval); or fixed extended (120 days' uninterrupted active hormonal intake followed by a 4-day tablet-free interval). Primary outcomes included the number of bleeding/spotting days during Year 1 (all regimens) and the number of observed unintended pregnancies over 2 years (flexibleMIB only). Results Results were analysed in 1067 women (full analysis set). The mean number of bleeding/spotting days was lower with the flexibleMIB vs the conventional regimen [41.0±29.1 (95% CI 38.8–43.3) vs 65.8±27.0 (95% CI 62.2–69.4) days, p<0.0001; treatment difference −24.8 (95% CI −29.2 to −20.3) days]. The corresponding value for the fixed extended regimen was 60.9±51.1 (95% CI 53.9–67.9) days. The Pearl Index for the flexibleMIB regimen was 0.64 (95% CI 0.28–1.26). All regimens had comparable tolerability profiles. Conclusions EE 20 μg/DRSP 3 mg administered as a flexible extended regimen with MIB is effective, well tolerated and is associated with statistically significantly fewer bleeding/spotting days and fewer withdrawal bleeding episodes vs EE/DRSP in a conventional 28-day regimen. The flexibleMIB also provided statistically significantly fewer spotting days vs EE/DRSP in a fixed extended 124-day regimen (post hoc evaluation). The flexibleMIB regimen allows women to extend their menstrual cycle and manage their intracyclic (breakthrough) bleeding. PMID:22454003

Bleeding profile of a flexible extended regimen of ethinylestradiol/drospirenone in US women: an open-label, three-arm, active-controlled, multicenter study.

PubMed

Jensen, Jeffrey T; Garie, Sona Grossova; Trummer, Dietmar; Elliesen, Jörg

2012-08-01

Unscheduled bleeding may affect satisfaction and compliance with extended oral contraceptive (OC) regimens. The bleeding patterns of two variants of a flexible dosing regimen designed to manage intracyclic bleeding problems during extended cycles were compared with that of a conventional OC regimen. This was a 1-year, open-label, active-controlled, Phase 3 study conducted in the USA. Healthy women (18-45 years) received an ethinylestradiol (EE) 20 mcg/drospirenone 3 mg OC in two flexible extended regimens or in a conventional 24/4 (i.e., 28-day) regimen. The primary regimen [management of intracyclic bleeding (flexible(MIB)) regimen] was an extended dosing regimen that required subjects to initiate 4-day tablet-free intervals after 3 days of breakthrough bleeding/spotting. An alternative extended regimen [active period control (flexible(APC)) regimen] allowed subjects to initiate a 4-day tablet-free interval irrespective of the occurrence of bleeding. Bleeding profiles were compared between treatments. Efficacy and safety outcomes were also assessed. The full analysis set comprised 1864 women (flexible(MIB), N=1406; flexible(APC), N=232; conventional 24/4, N=226). Over 1 year, subjects in the flexible(MIB) group experienced significantly fewer (mean±SD, 40±30) bleeding/spotting days than those in the conventional 24/4 group (52±35). The corresponding value in the flexible(APC) group was 47±33 days. The pregnancy rate in the flexible(MIB) group was 1.65 per 100 woman-years (95% confidence interval, 0.96-2.65). All three regimens were well tolerated. A flexible(MIB) dosing regimen of EE 20 mcg/drospirenone 3 mg is associated with good contraceptive efficacy and fewer bleeding/spotting days than the conventional 24/4 regimen. Copyright © 2012 Elsevier Inc. All rights reserved.

Long-term tolerability of ethinylestradiol 20 µg/drospirenone 3 mg in a flexible extended regimen: results from a randomised, controlled, multicentre study

PubMed Central

Klipping, Christine; Duijkers, Ingrid; Fortier, Michel P; Marr, Joachim; Trummer, Dietmar; Elliesen, Jörg

2012-01-01

Background This study was designed to assess the long-term safety and tolerability of a new flexible extended regimen of ethinylestradiol (EE) 20 μg/drospirenone (DRSP) 3 mg, which allows management of intracyclic (breakthrough) bleeding [flexible management of intracyclic (breakthrough) bleeding (MIB)], in comparison to conventional 28-day and fixed extended regimens. Study design In this Phase III, multicentre, open-label study, women (aged 18–35 years) were randomised to EE/DRSP in the following regimens: flexibleMIB (24–120 days' active hormonal intake followed by a 4-day tablet-free interval), conventional 28-day (24 days' active hormonal intake followed by a 4-day hormone-free interval) or fixed extended (120 days' uninterrupted active hormonal intake followed by a 4-day tablet-free interval) during a 1-year comparative phase. Thereafter, women entered a 1-year safety extension phase in which the majority received the flexibleMIB regimen. Safety/tolerability outcomes were measured over 2 years. A separate analysis of certain safety parameters (endometrial, hormonal, lipid, haemostatic and metabolic variables) was conducted at two of the study centres. Results Results were analysed in 1067 and 783 women in the comparative and safety extension phases. Overall, 56.3% of women experienced ≥1 adverse event (AE) in the safety extension phase. Serious AEs occurred in 3.0%, 1.4% and 3.3% of women receiving the flexibleMIB, conventional and fixed extended regimens, respectively. No unexpected endometrial, hormonal, lipid, haemostatic or metabolic findings occurred with any of the three regimens. Conclusions EE/DRSP in a flexible extended regimen with management of intracyclic (breakthrough) bleeding is well-tolerated and, when administered for up to 2 years, has a good safety profile comparable to other estrogen/progestogen oral contraceptives. PMID:22454004

Effectiveness of extended contact interventions for weight management delivered via text messaging: a systematic review and meta-analysis.

PubMed

Job, J R; Fjeldsoe, B S; Eakin, E G; Reeves, M M

2018-04-01

Extended contact interventions provide support for continued weight management (weight loss/prevention of weight regain) following a weight loss intervention. Text messages offer a medium for delivery in a potentially cost-effective, broad-reach manner. This study aims to examine (i) the effectiveness of extended contact, text message interventions for adults in supporting weight management, and (ii) which intervention characteristics are common to those that are effective. A systematic database search (to 19 September 2016) was conducted. Meta-analyses were performed to quantify the average weight changes (kg) during the extended contact intervention, net of control (if a control group was present) and within-group. Seven studies were eligible for inclusion. The pooled effect of the extended contact intervention compared with control (n = 3 studies) was -0.82 kg (95% confidence interval -1.43, -0.21), while the pooled within-group weight loss (n = 6 studies) during the extended contact interventions was -2.16 kg (95% confidence interval -3.40, -0.91). Interventions considered 'effective' (n = 4) were more likely to be >12 weeks duration, compared with interventions considered 'ineffective' (n = 3). Evidence from the small number of studies reviewed suggests that extended contact, text message-delivered interventions are effective. Further research is required to elucidate effective intervention components and the longer-term impact on weight, diet and physical activity behaviour. © 2017 World Obesity Federation.

Commentary on Holmes et al. (2007): resolving the debate on when extinction risk is predictable.

PubMed

Ellner, Stephen P; Holmes, Elizabeth E

2008-08-01

We reconcile the findings of Holmes et al. (Ecology Letters, 10, 2007, 1182) that 95% confidence intervals for quasi-extinction risk were narrow for many vertebrates of conservation concern, with previous theory predicting wide confidence intervals. We extend previous theory, concerning the precision of quasi-extinction estimates as a function of population dynamic parameters, prediction intervals and quasi-extinction thresholds, and provide an approximation that specifies the prediction interval and threshold combinations where quasi-extinction estimates are precise (vs. imprecise). This allows PVA practitioners to define the prediction interval and threshold regions of safety (low risk with high confidence), danger (high risk with high confidence), and uncertainty.

The outcome and risk factors for recurrence and extended hospitalization of secondary spontaneous pneumothorax.

PubMed

Saito, Yoshitaro; Suzuki, Yohei; Demura, Ryo; Kawai, Hideki

2018-03-01

Secondary spontaneous pneumothorax (SSP) is difficult to treat by itself and due to its association with serious underlying diseases. It has a high rate of recurrence and often requires extended hospitalization. Therefore, we evaluated the outcome and risk factors associated with recurrence and extended hospitalization. We retrospectively examined 61 patients with SSP, and evaluated the patients' characteristics, underlying diseases, introduction of home oxygen therapy, Brinkman index, and X-ray imaging findings to determine the risk factors for recurrence and extended hospitalization. There were 28 patients (46.0%) with chronic obstructive pulmonary disease, 8 (13.1%) with interstitial pneumonia, 16 (26.2%) with massive emphysema, and 9 (14.8%) with other diseases. Adhesion and mediastinal shift visualized by X-ray imaging were observed in 37 (37.9%) and 25 patients (40.1%), respectively. Recurrence occurred in 25 patients (40.9%) and the average hospitalization duration was 14.5 days (±11.2). A multivariate analysis showed that adhesion on X-ray imaging was a significant risk factor for recurrence (odds ratio 4.90, 95% confidence interval 1.38-21.44) and mediastinal shift on X-ray imaging was a significant risk factor for extended hospitalization (odds ratio 6.05, 95% confidence interval 1.44-31.06). Findings from X-ray imaging, and not underlying diseases, are risk factors for recurrence and extended hospitalization.

Temporal coherence of phenological and climatic rhythmicity in Beijing

NASA Astrophysics Data System (ADS)

Chen, Xiaoqiu; Zhang, Weiqi; Ren, Shilong; Lang, Weiguang; Liang, Boyi; Liu, Guohua

2017-10-01

Using woody plant phenological data in the Beijing Botanical Garden from 1979 to 2013, we revealed three levels of phenology rhythms and examined their coherence with temperature rhythms. First, the sequential and correlative rhythm shows that occurrence dates of various phenological events obey a certain time sequence within a year and synchronously advance or postpone among years. The positive correlation between spring phenophase dates is much stronger than that between autumn phenophase dates and attenuates as the time interval between two spring phenophases increases. This phenological rhythm can be explained by positive correlation between above 0 °C mean temperatures corresponding to different phenophase dates. Second, the circannual rhythm indicates that recurrence interval of a phenophase in the same species in two adjacent years is about 365 days, which can be explained by the 365-day recurrence interval in the first and last dates of threshold temperatures. Moreover, an earlier phenophase date in the current year may lead to a later phenophase date in the next year through extending recurrence interval. Thus, the plant phenology sequential and correlative rhythm and circannual rhythm are interacted, which mirrors the interaction between seasonal variation and annual periodicity of temperature. Finally, the multi-year rhythm implies that phenophase dates display quasi-periodicity more than 1 year. The same 12-year periodicity in phenophase and threshold temperature dates confirmed temperature controls of the phenology multi-year rhythm. Our findings provide new perspectives for examining phenological response to climate change and developing comprehensive phenology models considering temporal coherence of phenological and climatic rhythmicity.

Estimating Seismic Hazards from the Catalog of Taiwan Earthquakes from 1900 to 2014 in Terms of Maximum Magnitude

NASA Astrophysics Data System (ADS)

Chen, Kuei-Pao; Chang, Wen-Yen

2017-04-01

Maximum expected earthquake magnitude is an important parameter when designing mitigation measures for seismic hazards. This study calculated the maximum magnitude of potential earthquakes for each cell in a 0.1° × 0.1° grid of Taiwan. Two zones vulnerable to maximum magnitudes of M w ≥6.0, which will cause extensive building damage, were identified: one extends from Hsinchu southward to Taichung, Nantou, Chiayi, and Tainan in western Taiwan; the other extends from Ilan southward to Hualian and Taitung in eastern Taiwan. These zones are also characterized by low b values, which are consistent with high peak ground shaking. We also employed an innovative method to calculate (at intervals of M w 0.5) the bounds and median of recurrence time for earthquakes of magnitude M w 6.0-8.0 in Taiwan.

Cost and Return on Investment of a Work-Family Intervention in the Extended Care Industry: Evidence From the Work, Family, and Health Network.

PubMed

Dowd, William N; Bray, Jeremy W; Barbosa, Carolina; Brockwood, Krista; Kaiser, David J; Mills, Michael J; Hurtado, David A; Wipfli, Brad

2017-10-01

To estimate the cost and return on investment (ROI) of an intervention targeting work-family conflict (WFC) in the extended care industry. Costs to deliver the intervention during a group-randomized controlled trial were estimated, and data on organizational costs-presenteeism, health care costs, voluntary termination, and sick time-were collected from interviews and administrative data. Generalized linear models were used to estimate the intervention's impact on organizational costs. Combined, these results produced ROI estimates. A cluster-robust confidence interval (CI) was estimated around the ROI estimate. The per-participant cost of the intervention was $767. The ROI was -1.54 (95% CI: -4.31 to 2.18). The intervention was associated with a $668 reduction in health care costs (P < 0.05). This paper builds upon and expands prior ROI estimation methods to a new setting.

Extended cold snare polypectomy for small colorectal polyps increases the R0 resection rate.

PubMed

Abe, Yasuhiro; Nabeta, Haruaki; Koyanagi, Ryota; Nakamichi, Taro; Hirashima, Hayato; Lefor, Alan Kawarai; Shinozaki, Satoshi

2018-02-01

 Despite widespread use of cold snare polypectomy (CSP), the R0 resection rate is not well documented. We perform extended CSP, resecting polyps with a > 1 mm circumferential margin. The aim of this study is to compare the R0 resection rate of extended CSP with conventional CSP and to assess safety. From April 2014 to September 2016, 712 non-pedunculated colorectal polyps, < 10 mm in size, resected using CSP from 316 patients were retrospectively analyzed.  We divided lesions into conventional CSP (n = 263) and extended CSP groups (n = 449). The baseline characteristics of these two groups were not significantly different in univariate or multivariate analyses. Sessile polyps comprised 94 % (668/712), and the remaining were flat-elevated polyps. Mean size of polyps (±standard deviation) was 4.2 ± 1.5 mm. The most frequent pathology was low grade adenoma (97 %, 689/712). The R0 resection rate was significantly higher in the extended CSP group (439/449 [98 %]) than in the conventional CSP group (222/263 [84 %], P  < 0.001). There was no delayed bleeding or perforation in either group (conventional CSP group, 0/263, 95 % confidence interval: 0.0 - 1.4 % and extended CSP group, 0/449, 95 % confidence interval: 0.0 - 0.8 %).  Extended CSP results in a higher R0 resection rate compared with conventional CSP. Extended CSP did not result in a higher rate of delayed bleeding or perforation. Extended CSP is a safe and promising procedure for endoscopic resection of non-pedunculated colorectal polyps < 10 mm in size.

A time reversal algorithm in acoustic media with Dirac measure approximations

NASA Astrophysics Data System (ADS)

Bretin, Élie; Lucas, Carine; Privat, Yannick

2018-04-01

This article is devoted to the study of a photoacoustic tomography model, where one is led to consider the solution of the acoustic wave equation with a source term writing as a separated variables function in time and space, whose temporal component is in some sense close to the derivative of the Dirac distribution at t  =  0. This models a continuous wave laser illumination performed during a short interval of time. We introduce an algorithm for reconstructing the space component of the source term from the measure of the solution recorded by sensors during a time T all along the boundary of a connected bounded domain. It is based at the same time on the introduction of an auxiliary equivalent Cauchy problem allowing to derive explicit reconstruction formula and then to use of a deconvolution procedure. Numerical simulations illustrate our approach. Finally, this algorithm is also extended to elasticity wave systems.

An arbitrary-order staggered time integrator for the linear acoustic wave equation

NASA Astrophysics Data System (ADS)

Lee, Jaejoon; Park, Hyunseo; Park, Yoonseo; Shin, Changsoo

2018-02-01

We suggest a staggered time integrator whose order of accuracy can arbitrarily be extended to solve the linear acoustic wave equation. A strategy to select the appropriate order of accuracy is also proposed based on the error analysis that quantitatively predicts the truncation error of the numerical solution. This strategy not only reduces the computational cost several times, but also allows us to flexibly set the modelling parameters such as the time step length, grid interval and P-wave speed. It is demonstrated that the proposed method can almost eliminate temporal dispersive errors during long term simulations regardless of the heterogeneity of the media and time step lengths. The method can also be successfully applied to the source problem with an absorbing boundary condition, which is frequently encountered in the practical usage for the imaging algorithms or the inverse problems.

Program Monitoring with LTL in EAGLE

NASA Technical Reports Server (NTRS)

Barringer, Howard; Goldberg, Allen; Havelund, Klaus; Sen, Koushik

2004-01-01

We briefly present a rule-based framework called EAGLE, shown to be capable of defining and implementing finite trace monitoring logics, including future and past time temporal logic, extended regular expressions, real-time and metric temporal logics (MTL), interval logics, forms of quantified temporal logics, and so on. In this paper we focus on a linear temporal logic (LTL) specialization of EAGLE. For an initial formula of size m, we establish upper bounds of O(m(sup 2)2(sup m)log m) and O(m(sup 4)2(sup 2m)log(sup 2) m) for the space and time complexity, respectively, of single step evaluation over an input trace. This bound is close to the lower bound O(2(sup square root m) for future-time LTL presented. EAGLE has been successfully used, in both LTL and metric LTL forms, to test a real-time controller of an experimental NASA planetary rover.

Enhanced DNA Profiling of the Semen Donor in Late Reported Sexual Assaults: Use of Y-Chromosome-Targeted Pre-amplification and Next Generation Y-STR Amplification Systems.

PubMed

Hanson, Erin K; Ballantyne, Jack

2016-01-01

In some cases of sexual assault the victim may not report the assault for several days after the incident due to various factors. The ability to obtain an autosomal STR profile of the semen donor from a living victim rapidly diminishes as the post-coital interval is extended due to the presence of only a small amount of male DNA amidst an overwhelming amount of female DNA. Previously, we have utilized various technological tools to overcome the limitations of male DNA profiling in extended interval post-coital samples including the use of Y-chromosome STR profiling, cervical sample, and post-PCR purification permitting the recovery of Y-STR profiles of the male DNA from samples collected 5-6 days after intercourse. Despite this success, the reproductive biology literature reports the presence of spermatozoa in the human cervix up to 7-10 days post-coitus. Therefore, novel and improved methods for recovery of male profiles in extended interval post-coital samples were required. Here, we describe enhanced strategies, including Y-chromosome-targeted pre-amplification and next generation Y-STR amplification kits, that have resulted in the ability to obtain probative male profiles from samples collected 6-9 days after intercourse.

Multiple Independent Genetic Factors at NOS1AP Modulate the QT Interval in a Multi-Ethnic Population

PubMed Central

Arking, Dan E.; Khera, Amit; Xing, Chao; Kao, W. H. Linda; Post, Wendy; Boerwinkle, Eric; Chakravarti, Aravinda

2009-01-01

Extremes of electrocardiographic QT interval are associated with increased risk for sudden cardiac death (SCD); thus, identification and characterization of genetic variants that modulate QT interval may elucidate the underlying etiology of SCD. Previous studies have revealed an association between a common genetic variant in NOS1AP and QT interval in populations of European ancestry, but this finding has not been extended to other ethnic populations. We sought to characterize the effects of NOS1AP genetic variants on QT interval in the multi-ethnic population-based Dallas Heart Study (DHS, n = 3,072). The SNP most strongly associated with QT interval in previous samples of European ancestry, rs16847548, was the most strongly associated in White (P = 0.005) and Black (P = 3.6×10−5) participants, with the same direction of effect in Hispanics (P = 0.17), and further showed a significant SNP × sex-interaction (P = 0.03). A second SNP, rs16856785, uncorrelated with rs16847548, was also associated with QT interval in Blacks (P = 0.01), with qualitatively similar results in Whites and Hispanics. In a previously genotyped cohort of 14,107 White individuals drawn from the combined Atherosclerotic Risk in Communities (ARIC) and Cardiovascular Health Study (CHS) cohorts, we validated both the second locus at rs16856785 (P = 7.63×10−8), as well as the sex-interaction with rs16847548 (P = 8.68×10−6). These data extend the association of genetic variants in NOS1AP with QT interval to a Black population, with similar trends, though not statistically significant at P<0.05, in Hispanics. In addition, we identify a strong sex-interaction and the presence of a second independent site within NOS1AP associated with the QT interval. These results highlight the consistent and complex role of NOS1AP genetic variants in modulating QT interval. PMID:19180230

Aflibercept treatment for neovascular AMD beyond the first year: consensus recommendations by a UK expert roundtable panel, 2017 update

PubMed Central

Patel, Praveen J; Devonport, Helen; Sivaprasad, Sobha; Ross, Adam H; Walters, Gavin; Gale, Richard P; Lotery, Andrew J; Mahmood, Sajjad; Talks, James S; Napier, Jackie

2017-01-01

National recommendations on continued administration of aflibercept solution for injection after the first year of treatment for neovascular age-related macular degeneration (nAMD) have been developed by an expert panel of UK retina specialists, based on clinician experience and treatment outcomes seen in year 2. The 2017 update reiterates that the treatment goal is to maintain or improve the macular structural and functional gains achieved in year 1 while attempting to reduce or minimize the treatment burden, recognizing the need for ongoing treatment. At the end of year 1 (ie, the decision visit at month 11), two treatment options should be considered: do not extend the treatment interval and maintain fixed 8-weekly dosing, or extend the treatment interval using a treat-and-extend regimen up to a maximum 12 weeks. Criteria for considering not extending the treatment interval are persistent macular fluid with stable vision, recurrent fluid, decrease in vision in the presence of fluid, macular hemorrhage, new choroidal neovascularization or any other sign(s) of exudative disease activity considered vision threatening in the opinion of the treating clinician. Treatment extension is recommended for eyes with a dry macula (ie, without macular fluid) and stable vision. Under both options, the treatment interval may be shortened if visual and/or anatomic outcomes deteriorate. Monitoring without treatment may be considered for eyes with a fluid-free macula for a minimum duration of 48 weeks. A patient completing one full year of monitoring without requiring injections may be considered for discharge from clinic. The treatment algorithm incorporates return to fixed 8-weekly dosing for disease reactivation during treatment extension and reinstatement of treatment for disease recurrence following discontinuation or discharge. For bilateral nAMD, either the eye requiring the more intensive treatment or the eye with the better vision, guided by local clinical practice, should determine the retreatment schedule overall. PMID:29184385

Aflibercept treatment for neovascular AMD beyond the first year: consensus recommendations by a UK expert roundtable panel, 2017 update.

PubMed

Patel, Praveen J; Devonport, Helen; Sivaprasad, Sobha; Ross, Adam H; Walters, Gavin; Gale, Richard P; Lotery, Andrew J; Mahmood, Sajjad; Talks, James S; Napier, Jackie

2017-01-01

National recommendations on continued administration of aflibercept solution for injection after the first year of treatment for neovascular age-related macular degeneration (nAMD) have been developed by an expert panel of UK retina specialists, based on clinician experience and treatment outcomes seen in year 2. The 2017 update reiterates that the treatment goal is to maintain or improve the macular structural and functional gains achieved in year 1 while attempting to reduce or minimize the treatment burden, recognizing the need for ongoing treatment. At the end of year 1 (ie, the decision visit at month 11), two treatment options should be considered: do not extend the treatment interval and maintain fixed 8-weekly dosing, or extend the treatment interval using a treat-and-extend regimen up to a maximum 12 weeks. Criteria for considering not extending the treatment interval are persistent macular fluid with stable vision, recurrent fluid, decrease in vision in the presence of fluid, macular hemorrhage, new choroidal neovascularization or any other sign(s) of exudative disease activity considered vision threatening in the opinion of the treating clinician. Treatment extension is recommended for eyes with a dry macula (ie, without macular fluid) and stable vision. Under both options, the treatment interval may be shortened if visual and/or anatomic outcomes deteriorate. Monitoring without treatment may be considered for eyes with a fluid-free macula for a minimum duration of 48 weeks. A patient completing one full year of monitoring without requiring injections may be considered for discharge from clinic. The treatment algorithm incorporates return to fixed 8-weekly dosing for disease reactivation during treatment extension and reinstatement of treatment for disease recurrence following discontinuation or discharge. For bilateral nAMD, either the eye requiring the more intensive treatment or the eye with the better vision, guided by local clinical practice, should determine the retreatment schedule overall.

Workshop on imaging science development for cancer prevention and preemption.

PubMed

Kelloff, Gary J; Sullivan, Daniel C; Baker, Houston; Clarke, Lawrence P; Nordstrom, Robert; Tatum, James L; Dorfman, Gary S; Jacobs, Paula; Berg, Christine D; Pomper, Martin G; Birrer, Michael J; Tempero, Margaret; Higley, Howard R; Petty, Brenda Gumbs; Sigman, Caroline C; Maley, Carlo; Sharma, Prateek; Wax, Adam; Ginsberg, Gregory G; Dannenberg, Andrew J; Hawk, Ernest T; Messing, Edward M; Grossman, H Barton; Harisinghani, Mukesh; Bigio, Irving J; Griebel, Donna; Henson, Donald E; Fabian, Carol J; Ferrara, Katherine; Fantini, Sergio; Schnall, Mitchell D; Zujewski, Jo Anne; Hayes, Wendy; Klein, Eric A; DeMarzo, Angelo; Ocak, Iclal; Ketterling, Jeffrey A; Tempany, Clare; Shtern, Faina; Parnes, Howard L; Gomez, Jorge; Srivastava, Sudhir; Szabo, Eva; Lam, Stephen; Seibel, Eric J; Massion, Pierre; McLennan, Geoffrey; Cleary, Kevin; Suh, Robert; Burt, Randall W; Pfeiffer, Ruth M; Hoffman, John M; Roy, Hemant K; Wang, Thomas; Limburg, Paul J; El-Deiry, Wafik S; Papadimitrakopoulou, Vali; Hittelman, Walter N; MacAulay, Calum; Veltri, Robert W; Solomon, Diane; Jeronimo, Jose; Richards-Kortum, Rebecca; Johnson, Karen A; Viner, Jaye L; Stratton, Steven P; Rajadhyaksha, Milind; Dhawan, Atam

2007-01-01

The concept of intraepithelial neoplasm (IEN) as a near-obligate precursor of cancers has generated opportunities to examine drug or device intervention strategies that may reverse or retard the sometimes lengthy process of carcinogenesis. Chemopreventive agents with high therapeutic indices, well-monitored for efficacy and safety, are greatly needed, as is development of less invasive or minimally disruptive visualization and assessment methods to safely screen nominally healthy but at-risk patients, often for extended periods of time and at repeated intervals. Imaging devices, alone or in combination with anticancer drugs, may also provide novel interventions to treat or prevent precancer.

Solid sorbent air sampler

NASA Technical Reports Server (NTRS)

Galen, T. J. (Inventor)

1986-01-01

A fluid sampler for collecting a plurality of discrete samples over separate time intervals is described. The sampler comprises a sample assembly having an inlet and a plurality of discreet sample tubes each of which has inlet and outlet sides. A multiport dual acting valve is provided in the sampler in order to sequentially pass air from the sample inlet into the selected sample tubes. The sample tubes extend longitudinally of the housing and are located about the outer periphery thereof so that upon removal of an enclosure cover, they are readily accessible for operation of the sampler in an analysis mode.

Rescaling of temporal expectations during extinction

PubMed Central

Drew, Michael R.; Walsh, Carolyn; Balsam, Peter D

2016-01-01

Previous research suggests that extinction learning is temporally specific. Changing the CS duration between training and extinction can facilitate the loss of the CR within the extinction session but impairs long-term retention of extinction. In two experiments using conditioned magazine approach with rats, we examined the relation between temporal specificity of extinction and CR timing. In Experiment 1 rats were trained on a 12-s, fixed CS-US interval and then extinguished with CS presentations that were 6, 12, or 24 s in duration. The design of Experiment 2 was the same except rats were trained using partial rather than continuous reinforcement. In both experiments, extending the CS duration in extinction facilitated the diminution of CRs during the extinction session, but shortening the CS duration failed to slow extinction. In addition, extending (but not shortening) the CS duration caused temporal rescaling of the CR, in that the peak CR rate migrated later into the trial over the course of extinction training. This migration partially accounted for the faster loss of the CR when the CS duration was extended. Results are incompatible with the hypothesis that extinction is driven by cumulative CS exposure and suggest that temporally extended nonreinforced CS exposure reduces conditioned responding via temporal displacement rather than through extinction per se. PMID:28045291

Analysis of the deconstruction of Dyke Marsh, George Washington Memorial Parkway, Virginia-Progression, geologic and manmade causes, and effective restoration scenarios

USGS Publications Warehouse

Litwin, Ronald J.; Smoot, Joseph P.; Pavich, Milan J.; Markewich, Helaine W.; Oberg, Erik; Helwig, Ben; Steury, Brent; Santucci, Vincent L.; Durika, Nancy J.; Rybicki, Nancy B.; Engelhardt, Katharina M.; Sanders, Geoffrey; Verardo, Stacey; Elmore, Andrew J.; Gilmer, Joseph

2011-01-01

Photoanalysis of time-sequence aerial photographs of Dyke Marsh enabled us to calculate shoreline erosion estimates for this marsh over 19 years (1987-2006), as well as to quantify overall marsh acreage for 6 calendar years spanning an ~70 year interval (1937-2006). Photo overlay of a historic map enabled us to extend our whole-marsh acreage calculations back to 1883. Both sets of analyses were part of a geologic framework study in support of current efforts by the National Park Service (NPS) to restore this urban wetland. Two time intervals were selected for our shoreline erosion analyses, based on image quality and availability: 1987 to 2002, and 2002 to 2006. The more recent time interval shows a marked increase in erosion in the southern part of Dyke Marsh, following a wave-induced breach of a small peninsula that had protected its southern shoreline. Field observations and analyses of annual aerial imagery between 1987 and 2006 revealed a progressive increase in wave-induced erosion that presently is deconstructing Hog Island Gut, the last significant tidal creek network within the Dyke Marsh. These photo analyses documented an overall average westward shoreline loss of 6.0 to 7.8 linear feet per year along the Potomac River during this 19-year time interval. Additionally, photographic evidence documented that lateral erosion now is capturing existing higher order tributaries in the Hog Island Gut. Wave-driven stream piracy is fragmenting the remaining marsh habitat, and therefore its connectivity, relatively rapidly, causing the effective mouth of the Hog Island Gut tidal network to retreat headward visibly over the past several decades. Based on our estimates of total marsh area in the Dyke Marsh derived from 1987 aerial imagery, as much as 12 percent of the central part of the marsh has eroded in the 19 year period we studied (or ~7.5 percent of the original ~78.8 acres of 1987 marshland). Shoreline loss estimates for marsh parcels north and south of our study area have not yet been analyzed, although annual aerial photos from 1987 to 2002 confirm visible progressive shoreline loss in those areas over this same time interval.

The Evolution of Deep Space Navigation: 1989-1999

NASA Technical Reports Server (NTRS)

Wood, Lincoln J.

2008-01-01

The exploration of the planets of the solar system using robotic vehicles has been underway since the early 1960s. During this time the navigational capabilities employed have increased greatly in accuracy, as required by the scientific objectives of the missions and as enabled by improvements in technology. This paper is the second in a chronological sequence dealing with the evolution of deep space navigation. The time interval covered extends from the 1989 launch of the Magellan spacecraft to Venus through a multiplicity of planetary exploration activities in 1999. The paper focuses on the observational techniques that have been used to obtain navigational information, propellant-efficient means for modifying spacecraft trajectories, and the computational methods that have been employed, tracing their evolution through a dozen planetary missions.

A model for foreign exchange markets based on glassy Brownian systems

PubMed Central

Trinidad-Segovia, J. E.; Clara-Rahola, J.; Puertas, A. M.; De las Nieves, F. J.

2017-01-01

In this work we extend a well-known model from arrested physical systems, and employ it in order to efficiently depict different currency pairs of foreign exchange market price fluctuation distributions. We consider the exchange rate price in the time range between 2010 and 2016 at yearly time intervals and resolved at one minute frequency. We then fit the experimental datasets with this model, and find significant qualitative symmetry between price fluctuation distributions from the currency market, and the ones belonging to colloidal particles position in arrested states. The main contribution of this paper is a well-known physical model that does not necessarily assume the independent and identically distributed (i.i.d.) restrictive condition. PMID:29206868

Discrimination of edible oils and fats by combination of multivariate pattern recognition and FT-IR spectroscopy: A comparative study between different modeling methods

NASA Astrophysics Data System (ADS)

Javidnia, Katayoun; Parish, Maryam; Karimi, Sadegh; Hemmateenejad, Bahram

2013-03-01

By using FT-IR spectroscopy, many researchers from different disciplines enrich the experimental complexity of their research for obtaining more precise information. Moreover chemometrics techniques have boosted the use of IR instruments. In the present study we aimed to emphasize on the power of FT-IR spectroscopy for discrimination between different oil samples (especially fat from vegetable oils). Also our data were used to compare the performance of different classification methods. FT-IR transmittance spectra of oil samples (Corn, Colona, Sunflower, Soya, Olive, and Butter) were measured in the wave-number interval of 450-4000 cm-1. Classification analysis was performed utilizing PLS-DA, interval PLS-DA, extended canonical variate analysis (ECVA) and interval ECVA methods. The effect of data preprocessing by extended multiplicative signal correction was investigated. Whilst all employed method could distinguish butter from vegetable oils, iECVA resulted in the best performances for calibration and external test set with 100% sensitivity and specificity.

Children with Heavy Prenatal Alcohol Exposure have Different Frequency Domain Signal Characteristics when Producing Isometric Force

PubMed Central

Nguyen, Tanya T.; Ashrafi, Ashkan; Thomas, Jennifer D.; Riley, Edward P.; Simmons, Roger W.

2013-01-01

To extend our current understanding of the teratogenic effects of prenatal alcohol exposure on the control of isometric force, the present study investigated the signal characteristics of power spectral density functions resulting from sustained control of isometric force by children with and without heavy prenatal exposure to alcohol. It was predicted that the functions associated with the force signals would be fundamentally different for the two groups. Twenty-five children aged between 7 and 17 years with heavy prenatal alcohol exposure and 21 non-alcohol exposed control children attempted to duplicate a visually represented target force by pressing on a load cell. The level of target force (5 and 20% of maximum voluntary contraction) and the time interval between visual feedback (20ms, 320ms and 740ms) were manipulated. A multivariate spectral estimation method with sinusoidal windows was applied to individual isometric force-time signals. Analysis of the resulting power spectral density functions revealed that the alcohol-exposed children had a lower mean frequency, less spectral variability, greater peak power and a lower frequency at which peak power occurred. Furthermore, mean frequency and spectral variability produced by the alcohol-exposed group remained constant across target load and visual feedback interval, suggesting that these children were limited to making long-time scale corrections to the force signal. In contrast, the control group produced decreased mean frequency and spectral variability as target force and the interval between visual feedback increased, indicating that when feedback was frequently presented these children used the information to make short-time scale adjustments to the ongoing force signal. Knowledge of these differences could facilitate the design of motor rehabilitation exercises that specifically target isometric force control deficits in alcohol-exposed children. PMID:23238099

Use of Self-Matching to Control for Stable Patient Characteristics While Addressing Time-Varying Confounding on Treatment Effect: A Case Study of Older Intensive Care Patients.

PubMed

Han, Ling; Pisani, M A; Araujo, K L B; Allore, Heather G

Exposure-crossover design offers a non-experimental option to control for stable baseline confounding through self-matching while examining causal effect of an exposure on an acute outcome. This study extends this approach to longitudinal data with repeated measures of exposure and outcome using data from a cohort of 340 older medical patients in an intensive care unit (ICU). The analytic sample included 92 patients who received ≥1 dose of haloperidol, an antipsychotic medication often used for patients with delirium. Exposure-crossover design was implemented by sampling the 3-day time segments prior ( Induction) and posterior ( Subsequent) to each treatment episode of receiving haloperidol. In the full cohort, there was a trend of increasing delirium severity scores (Mean±SD: 4.4±1.7) over the course of the ICU stay. After exposure-crossover sampling, the delirium severity score decreased from the Induction (4.9) to the Subsequent (4.1) intervals, with the treatment episode falling in-between (4.5). Based on a GEE Poisson model accounting for self-matching and within-subject correlation, the unadjusted mean delirium severity scores was -0.55 (95% CI: -1.10, -0.01) points lower for the Subsequent than the Induction intervals. The association diminished by 32% (-0.38, 95%CI: -0.99, 0.24) after adjusting only for ICU confounding, while being slightly increased by 7% (-0.60, 95%CI: -1.15, -0.04) when adjusting only for baseline characteristics. These results suggest that longitudinal exposure-crossover design is feasible and capable of partially removing stable baseline confounding through self-matching. Loss of power due to eliminating treatment-irrelevant person-time and uncertainty around allocating person-time to comparison intervals remain methodological challenges.

In Vitro Emergence of High Persistence upon Periodic Aminoglycoside Challenge in the ESKAPE Pathogens.

PubMed

Michiels, Joran Elie; Van den Bergh, Bram; Verstraeten, Natalie; Fauvart, Maarten; Michiels, Jan

2016-08-01

Health care-associated infections present a major threat to modern medical care. Six worrisome nosocomial pathogens-Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.-are collectively referred to as the "ESKAPE bugs." They are notorious for extensive multidrug resistance, yet persistence, or the phenotypic tolerance displayed by a variant subpopulation, remains underappreciated in these pathogens. Importantly, persistence can prevent eradication of antibiotic-sensitive bacterial populations and is thought to act as a catalyst for the development of genetic resistance. Concentration- and time-dependent aminoglycoside killing experiments were used to investigate persistence in the ESKAPE pathogens. Additionally, a recently developed method for the experimental evolution of persistence was employed to investigate adaptation to high-dose, extended-interval aminoglycoside therapy in vitro We show that ESKAPE pathogens exhibit biphasic killing kinetics, indicative of persister formation. In vitro cycling between aminoglycoside killing and persister cell regrowth, evocative of clinical high-dose extended-interval therapy, caused a 37- to 213-fold increase in persistence without the emergence of resistance. Increased persistence also manifested in biofilms and provided cross-tolerance to different clinically important antibiotics. Together, our results highlight a possible drawback of intermittent, high-dose antibiotic therapy and suggest that clinical diagnostics might benefit from taking into account persistence. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

CIMP status of interval colon cancers: another piece to the puzzle.

PubMed

Arain, Mustafa A; Sawhney, Mandeep; Sheikh, Shehla; Anway, Ruth; Thyagarajan, Bharat; Bond, John H; Shaukat, Aasma

2010-05-01

Colon cancers diagnosed in the interval after a complete colonoscopy may occur due to limitations of colonoscopy or due to the development of new tumors, possibly reflecting molecular and environmental differences in tumorigenesis resulting in rapid tumor growth. In a previous study from our group, interval cancers (colon cancers diagnosed within 5 years of a complete colonoscopy) were almost four times more likely to demonstrate microsatellite instability (MSI) than non-interval cancers. In this study we extended our molecular analysis to compare the CpG island methylator phenotype (CIMP) status of interval and non-interval colorectal cancers and investigate the relationship between the CIMP and MSI pathways in the pathogenesis of interval cancers. We searched our institution's cancer registry for interval cancers, defined as colon cancers that developed within 5 years of a complete colonoscopy. These were frequency matched in a 1:2 ratio by age and sex to patients with non-interval cancers (defined as colon cancers diagnosed on a patient's first recorded colonoscopy). Archived cancer specimens for all subjects were retrieved and tested for CIMP gene markers. The MSI status of subjects identified between 1989 and 2004 was known from our previous study. Tissue specimens of newly identified cases and controls (between 2005 and 2006) were tested for MSI. There were 1,323 cases of colon cancer diagnosed over the 17-year study period, of which 63 were identified as having interval cancer and matched to 131 subjects with non-interval cancer. Study subjects were almost all Caucasian men. CIMP was present in 57% of interval cancers compared to 33% of non-interval cancers (P=0.004). As shown previously, interval cancers were more likely than non-interval cancers to occur in the proximal colon (63% vs. 39%; P=0.002), and have MSI 29% vs. 11%, P=0.004). In multivariable logistic regression model, proximal location (odds ratio (OR) 1.85; 95% confidence interval (CI) 1.01-3.8), MSI (OR 2.7; 95% CI 1.1-6.8) and CIMP (OR 2.41; 95% CI 1.2-4.9) were independently associated with interval cancers. CIMP was associated with interval cancers independent of MSI status. There was no difference in 5-year survival between the two groups. Interval cancers are more likely to arise in the proximal colon and demonstrate CIMP, which suggests there may be differences in biology between these and non-interval CRC. Additional studies are needed to determine whether interval cancers arise as a result of missed lesions or accelerated neoplastic progression.

A diagnostic process extended in time as a fuzzy model

NASA Astrophysics Data System (ADS)

Rakus-Andersson, Elisabeth; Gerstenkorn, Tadeusz

1999-03-01

The paper refers to earlier results obtained by the authors and constitutes their essential complement and extension by introducing to a diagnostic model the assumption that the decision concerning the diagnosis is based on observations of symptoms carried out repeatedly, by stages, which may have effect in a change of these symptoms in increasing time. The model concerns the observations of symptoms at an individual patient at a time interval. The changes of the symptoms give some additional information, sometimes very important in the diagnostic process when the clinical picture of a patient in a certain interval of time differs from that one which has been received from the beginning of the disease. It may occur that the change in the intensity of a symptom decides an acceptance of another diagnosis after some time when the patient does not feel better. The aim is to fix an optimal diagnosis on the basis of clinical symptoms typical of several morbid units with respect to the changes of these symptoms in time. In order to solve such a posed problem the authors apply the method of fuzzy relation equations which are modelled by means of logical rules of inference. Moreover, in the final decision concerning the choice of a proper diagnosis, a normed Euclidean distance is introduced as a measure between a real decision and an "ideal" decision. A simple example presents the practical action of the method to show its relevance to a possible user.

Extinction of specific stimulus-outcome (S-O) associations in Pavlovian learning with an extended CS procedure.

PubMed

Delamater, Andrew R; Schneider, Kevin; Derman, Rifka C

2017-07-01

Three experiments with male and female rats were conducted to examine the effects of Pavlovian extinction training on Pavlovian-to-instrumental transfer (PIT) in a task in which the unconditioned stimulus (US) was presented at an early time point within an extended conditioned stimulus (CS). Two instrumental responses were trained with different reinforcing outcomes (R1-O1, R2-O2) and then, independently, 2 stimuli were trained with those outcomes (S1-O1, S2-O2). One group then underwent an extinction treatment (S1-, S2-) and a second was merely exposed to the experimental contexts without any stimulus events. Finally, the effects of the 2 stimuli on instrumental responding were assessed in PIT tests. Across experiments we varied the number of Pavlovian training trials prior to extinction (8, 16, or 64 trials) and the length of time following extinction prior to test (i.e., 1 or 21 days, in a test for spontaneous recovery). We observed that outcome-specific PIT was reduced by extinction in all of our training conditions and that this extinction effect was durable, surviving a 3-week spontaneous recovery interval even though conditioned magazine approach spontaneously recovered over this interval. Although extinction reduced the magnitude of PIT, the temporal expression of PIT was mostly unaffected. We found these effects in both male and female rats, though in 1 study females were extinction-resistant. These data suggest that under the conditions studied here Pavlovian extinction may permanently weaken the ability of Pavlovian cues to retrieve a representation of their associated outcomes without impacting the temporal organization of responding. This suggests that different features of learning may be differentially sensitive to extinction. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Methods for calculating confidence and credible intervals for the residual between-study variance in random effects meta-regression models

PubMed Central

2014-01-01

Background Meta-regression is becoming increasingly used to model study level covariate effects. However this type of statistical analysis presents many difficulties and challenges. Here two methods for calculating confidence intervals for the magnitude of the residual between-study variance in random effects meta-regression models are developed. A further suggestion for calculating credible intervals using informative prior distributions for the residual between-study variance is presented. Methods Two recently proposed and, under the assumptions of the random effects model, exact methods for constructing confidence intervals for the between-study variance in random effects meta-analyses are extended to the meta-regression setting. The use of Generalised Cochran heterogeneity statistics is extended to the meta-regression setting and a Newton-Raphson procedure is developed to implement the Q profile method for meta-analysis and meta-regression. WinBUGS is used to implement informative priors for the residual between-study variance in the context of Bayesian meta-regressions. Results Results are obtained for two contrasting examples, where the first example involves a binary covariate and the second involves a continuous covariate. Intervals for the residual between-study variance are wide for both examples. Conclusions Statistical methods, and R computer software, are available to compute exact confidence intervals for the residual between-study variance under the random effects model for meta-regression. These frequentist methods are almost as easily implemented as their established counterparts for meta-analysis. Bayesian meta-regressions are also easily performed by analysts who are comfortable using WinBUGS. Estimates of the residual between-study variance in random effects meta-regressions should be routinely reported and accompanied by some measure of their uncertainty. Confidence and/or credible intervals are well-suited to this purpose. PMID:25196829

Extended-Interval Gentamicin Dosing in Achieving Therapeutic Concentrations in Malaysian Neonates

PubMed Central

Tan, Sin Li; Wan, Angeline SL

2015-01-01

OBJECTIVE: To evaluate the usefulness of extended-interval gentamicin dosing practiced in neonatal intensive care unit (NICU) and special care nursery (SCN) of a Malaysian hospital. METHODS: Cross-sectional observational study with pharmacokinetic analysis of all patients aged ≤28 days who received gentamicin treatment in NICU/SCN. Subjects received dosing according to a regimen modified from an Australian-based pediatric guideline. During a study period of 3 months, subjects were evaluated for gestational age, body weight, serum creatinine concentration, gentamicin dose/interval, serum peak and trough concentrations, and pharmacokinetic parameters. Descriptive percentages were used to determine the overall dosing accuracy, while analysis of variance (ANOVA) was conducted to compare the accuracy rates among different gestational ages. Pharmacokinetic profile among different gestational age and body weight groups were compared by using ANOVA. RESULTS: Of the 113 subjects included, 82.3% (n = 93) achieved therapeutic concentrations at the first drug-monitoring assessment. There was no significant difference found between the percentage of term neonates who achieved therapeutic concentrations and the premature group (87.1% vs. 74.4%), p = 0.085. A total of 112 subjects (99.1%) achieved desired therapeutic trough concentration of <2 mg/L. Mean gentamicin peak concentration was 8.52 mg/L (95% confidence interval [Cl], 8.13–8.90 mg/L) and trough concentration was 0.54 mg/L (95% CI, 0.48–0.60 mg/L). Mean volume of distribution, half-life, and elimination rate were 0.65 L/kg (95% CI, 0.62–0.68 L/kg), 6.96 hours (95% CI, 6.52–7.40 hours), and 0.11 hour−1 (95% CI, 0.10–0.11 hour−1), respectively. CONCLUSION: The larger percentage of subjects attaining therapeutic range with extended-interval gentamicin dosing suggests that this regimen is appropriate and can be safely used among Malaysian neonates. PMID:25964729

Echolocating Big Brown Bats, Eptesicus fuscus, Modulate Pulse Intervals to Overcome Range Ambiguity in Cluttered Surroundings

PubMed Central

Wheeler, Alyssa R.; Fulton, Kara A.; Gaudette, Jason E.; Simmons, Ryan A.; Matsuo, Ikuo; Simmons, James A.

2016-01-01

Big brown bats (Eptesicus fuscus) emit trains of brief, wideband frequency-modulated (FM) echolocation sounds and use echoes of these sounds to orient, find insects, and guide flight through vegetation. They are observed to emit sounds that alternate between short and long inter-pulse intervals (IPIs), forming sonar sound groups. The occurrence of these strobe groups has been linked to flight in cluttered acoustic environments, but how exactly bats use sonar sound groups to orient and navigate is still a mystery. Here, the production of sound groups during clutter navigation was examined. Controlled flight experiments were conducted where the proximity of the nearest obstacles was systematically decreased while the extended scene was kept constant. Four bats flew along a corridor of varying widths (100, 70, and 40 cm) bounded by rows of vertically hanging plastic chains while in-flight echolocation calls were recorded. Bats shortened their IPIs for more rapid spatial sampling and also grouped their sounds more tightly when flying in narrower corridors. Bats emitted echolocation calls with progressively shorter IPIs over the course of a flight, and began their flights by emitting shorter starting IPI calls when clutter was denser. The percentage of sound groups containing 3 or more calls increased with increasing clutter proximity. Moreover, IPI sequences having internal structure become more pronounced when corridor width narrows. A novel metric for analyzing the temporal organization of sound sequences was developed, and the results indicate that the time interval between echolocation calls depends heavily on the preceding time interval. The occurrence of specific IPI patterns were dependent upon clutter, which suggests that sonar sound grouping may be an adaptive strategy for coping with pulse-echo ambiguity in cluttered surroundings. PMID:27445723

A randomized crossover study to assess the pharmacokinetics of a novel amphetamine extended-release orally disintegrating tablet in healthy adults.

PubMed

Stark, Jeffrey G; Engelking, Dorothy; McMahen, Russ; Sikes, Carolyn

2016-09-01

In this pharmacokinetic (PK) study in healthy adults, we sought to: (1) compare the PK properties of a novel amphetamine extended-release orally disintegrating tablet formulation (Adzenys XR-ODT™ [AMP XR-ODT]) to a reference extended-release mixed amphetamine salts (MAS ER) formulation and (2) assess the effect of food on AMP XR-ODT. Forty-two adults were enrolled in a single-dose, open-label, 3-period, 3-treatment, randomized crossover study and received an 18.8-mg dose of AMP XR-ODT (fasted or fed) or equivalent dose (30 mg) of MAS ER (fasted). Plasma samples were analyzed for d-and l-amphetamine. Maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax), elimination half-life (T1/2), area under the concentration-time curve from time zero to last quantifiable concentration (AUClast), from time zero to infinity (AUCinf), relevant partial AUCs, and weight-normalized clearance (CL/F/kg) were assessed. The PK parameters were compared across treatments using an ANOVA. Safety was also assessed. A total of 39 adults completed this study. The geometric mean ratios (90% confidence interval [CI]) for AMP XR-ODT/MAS ER Cmax, AUC5-last, AUClast, and AUCinf were within 80%-125% for both d-and l-amphetamine. The 90% CIs for AUC0-5 were slightly below the 80%-125% range. When AMP XR-ODT was administered with food, there was a slight decrease in the d-and l-amphetamine Cmax and approximately a 2-hour delay in Tmax. The most common adverse events reported (>5% of participants) were dry mouth, palpitations, nausea, dizziness, headache, anxiety, and nasal congestion. AMP XR-ODT displayed a PK profile similar to MAS ER, and no clinically relevant food effect was observed.

Recommended Guidelines for Use of Intravitreal Aflibercept With a Treat-and-Extend Regimen for the Management of Neovascular Age-Related Macular Degeneration in the Asia-Pacific Region: Report From a Consensus Panel.

PubMed

Koh, Adrian; Lanzetta, Paolo; Lee, Won Ki; Lai, Chi-Chun; Chan, Wai-Man; Yang, Chung-May; Cheung, Chui Ming Gemmy

2017-01-01

To summarize recommendations for the use of intravitreal aflibercept with a treat-and-extend regimen to manage neovascular age-related macular degeneration (nAMD) in the Asia-Pacific region. Although anti-vascular endothelial growth factor therapies have improved the quality of life of patients with nAMD, a leading cause of blindness and visual impairment, the high treatment frequency recommended by current guidelines places a significant burden on patients and healthcare providers. Recommended guidelines from a consensus panel. An expert panel formed a consensus on recommendations for use of intravitreal aflibercept as treatment of nAMD in the Asia-Pacific region. After 3 initial monthly doses, treatment interval could be extended by 4-week increments, to a maximum of 12 weeks, in patients with inactive disease. Conversely, in active disease, treatment intervals should be shortened, by 4 weeks, or to 4 weeks in cases of severe recurrence. Treatment could be ceased in patients with stable disease activity after 12 months of treatment at 12-week intervals, as a means to prevent over treatent and lifelong injections. These recommendations could potentially minimize the number of treatments while maintaining efficacy and improve compliance by reducing the number of clinic visits compared with existing recommendations. Copyright 2017 Asia-Pacific Academy of Ophthalmology.

Efficacy and tolerability of six-week extended dosing interval with tocilizumab therapy in a prospective cohort as remission maintenance in patients with rheumatoid arthritis.

PubMed

Kikuchi, Jun; Kondo, Tsuneo; Shibata, Akiko; Sakai, Ryota; Okada, Yusuke; Chino, Kentaro; Okuyama, Ayumi; Kurasawa, Takahiko; Takei, Hirofumi; Amano, Koichi

2018-05-01

To prospectively evaluate the efficacy and tolerability of a six-week extended dosing interval with tocilizumab (TCZ) in patients with rheumatoid arthritis (RA) in sustained remission. Patients who received over six doses of intravenous TCZ in clinical remission (disease activity score [DAS] 28 - erythrocyte sedimentation rate [ESR] ≤ 2.6) maintained over 3 months between December 2013 and December 2015 were included. Flare was defined as DAS28-ESR >3.2 at two consecutive visits. Twenty-five patients were enrolled; 87.5% achieved clinical remission at week 54 after six-week extension and 95.5% achieved a van der Heijde modified total Sharp score (ΔmTSS) ≤0.5. The Health Assessment Questionnaire Disability Index (HAQ-DI) did not increase during 54 weeks. HAQ-DI at baseline and ΔDAS28-ESR at week six positively correlated with increase in DAS28-ESR at week 54. ΔSwollen joint count at week six positively correlated with ΔmTSS at week 54. A total of 12 adverse events occurring in 10 patients did not lead to cessation of TCZ except for one case of recurrent lymphoproliferative disorder at week five. A six-week extended dosing interval of TCZ for patients with RA in sustained remission is proposed as an acceptable treatment option for maintaining efficacy and tolerability.

A phase 1, multicentre, open-label study to evaluate ovarian follicular activity and hormone levels with an extended-regimen combined oral contraceptive with low-dose ethinyl estradiol supplementation.

PubMed

Kroll, Robin; Seidman, Larry; Ricciotti, Nancy; Howard, Brandon; Weiss, Herman

2015-01-01

To evaluate the effect on ovarian follicular activity of the 91-day extended-regimen combined oral contraceptive (COC), consisting of 84 days of levonorgestrel (LNG)/ethinylestradiol (EE) 150 μg/30 μg tablets plus seven days of EE 10 μg tablets in place of placebo. This was a phase 1, open-label study. Ovarian follicular activity was classified via the Hoogland and Skouby method. Safety and tolerability as well as return to ovulation were assessed. Of the 35 subjects included in the efficacy analysis, luteinized, unruptured follicles, or ovulation were detected in 0 of 35 cycles during the first 28-day interval; 1 of 35 cycles (2.9%) in the second 28-day interval; and 2 of 35 cycles (5.7%) in the final 35-day interval. The ovarian activity rate over the entire 91-day treatment period was 2.9%. There was a low incidence of treatment-emergent adverse events. Ovulation returned in most subjects (77.1%, 27/35) within 32 days following the last dose of COC. The 91-day extended-regimen COC with low-dose EE supplementation was found to be effective in suppressing ovarian activity and inhibiting ovulation and was well tolerated. Return to ovulation was rapid, occurring within approximately one month after discontinuation of COC.

System implications of the ambulance arrival-to-patient contact interval on response interval compliance.

PubMed

Campbell, J P; Gratton, M C; Salomone, J A; Lindholm, D J; Watson, W A

1994-01-01

In some emergency medical services (EMS) system designs, response time intervals are mandated with monetary penalties for noncompliance. These times are set with the goal of providing rapid, definitive patient care. The time interval of vehicle at scene-to-patient access (VSPA) has been measured, but its effect on response time interval compliance has not been determined. To determine the effect of the VSPA interval on the mandated code 1 (< 9 min) and code 2 (< 13 min) response time interval compliance in an urban, public-utility model system. A prospective, observational study used independent third-party riders to collect the VSPA interval for emergency life-threatening (code 1) and emergency nonlife-threatening (code 2) calls. The VSPA interval was added to the 9-1-1 call-to-dispatch and vehicle dispatch-to-scene intervals to determine the total time interval from call received until paramedic access to the patient (9-1-1 call-to-patient access). Compliance with the mandated response time intervals was determined using the traditional time intervals (9-1-1 call-to-scene) plus the VSPA time intervals (9-1-1 call-to-patient access). Chi-square was used to determine statistical significance. Of the 216 observed calls, 198 were matched to the traditional time intervals. Sixty-three were code 1, and 135 were code 2. Of the code 1 calls, 90.5% were compliant using 9-1-1 call-to-scene intervals dropping to 63.5% using 9-1-1 call-to-patient access intervals (p < 0.0005). Of the code 2 calls, 94.1% were compliant using 9-1-1 call-to-scene intervals. Compliance decreased to 83.7% using 9-1-1 call-to-patient access intervals (p = 0.012). The addition of the VSPA interval to the traditional time intervals impacts system response time compliance. Using 9-1-1 call-to-scene compliance as a basis for measuring system performance underestimates the time for the delivery of definitive care. This must be considered when response time interval compliances are defined.

Development of In Vitro-In Vivo Correlation for Potassium Chloride Extended Release Tablet Formulation Using Urinary Pharmacokinetic Data.

PubMed

Mittapalli, Rajendar K; Marroum, Patrick; Qiu, Yihong; Apfelbaum, Kathleen; Xiong, Hao

2017-07-01

To develop and validate a Level A in vitro-in vivo correlation (IVIVC) for potassium chloride extended-release (ER) formulations. Three prototype ER formulations of potassium chloride with different in vitro release rates were developed and their urinary pharmacokinetic profiles were evaluated in healthy subjects. A mathematical model between in vitro dissolution and in vivo urinary excretion, a surrogate for measuring in vivo absorption, was developed using time-scale and time-shift parameters. The IVIVC model was then validated based on internal and external predictability. With the established IVIVC model, there was a good correlation between the observed fraction of dose excreted in urine and the time-scaled and time-shifted fraction of the drug dissolved, and between the in vitro dissolution time and the in vivo urinary excretion time for the ER formulations. The percent prediction error (%PE) on cumulative urinary excretion over the 24 h interval (A e0-24h ) and maximum urinary excretion rate (R max ) was less than 15% for the individual formulations and less than 10% for the average of the two formulations used to develop the model. Further, the %PE values using external predictability were below 10%. A novel Level A IVIVC was successfully developed and validated for the new potassium chloride ER formulations using urinary pharmacokinetic data. This successful IVIVC may facilitate future development or manufacturing changes to the potassium chloride ER formulation.

Software Estimates Costs of Testing Rocket Engines

NASA Technical Reports Server (NTRS)

Smith, C. L.

2003-01-01

Simulation-Based Cost Model (SiCM), a discrete event simulation developed in Extend , simulates pertinent aspects of the testing of rocket propulsion test articles for the purpose of estimating the costs of such testing during time intervals specified by its users. A user enters input data for control of simulations; information on the nature of, and activity in, a given testing project; and information on resources. Simulation objects are created on the basis of this input. Costs of the engineering-design, construction, and testing phases of a given project are estimated from numbers and labor rates of engineers and technicians employed in each phase, the duration of each phase; costs of materials used in each phase; and, for the testing phase, the rate of maintenance of the testing facility. The three main outputs of SiCM are (1) a curve, updated at each iteration of the simulation, that shows overall expenditures vs. time during the interval specified by the user; (2) a histogram of the total costs from all iterations of the simulation; and (3) table displaying means and variances of cumulative costs for each phase from all iterations. Other outputs include spending curves for each phase.

Making a meaningful impact: modelling simultaneous frictional collisions in spatial multibody systems

PubMed Central

Uchida, Thomas K.; Sherman, Michael A.; Delp, Scott L.

2015-01-01

Impacts are instantaneous, computationally efficient approximations of collisions. Current impact models sacrifice important physical principles to achieve that efficiency, yielding qualitative and quantitative errors when applied to simultaneous impacts in spatial multibody systems. We present a new impact model that produces behaviour similar to that of a detailed compliant contact model, while retaining the efficiency of an instantaneous method. In our model, time and configuration are fixed, but the impact is resolved into distinct compression and expansion phases, themselves comprising sliding and rolling intervals. A constrained optimization problem is solved for each interval to compute incremental impulses while respecting physical laws and principles of contact mechanics. We present the mathematical model, algorithms for its practical implementation, and examples that demonstrate its effectiveness. In collisions involving materials of various stiffnesses, our model can be more than 20 times faster than integrating through the collision using a compliant contact model. This work extends the use of instantaneous impact models to scientific and engineering applications with strict accuracy requirements, where compliant contact models would otherwise be required. An open-source implementation is available in Simbody, a C++ multibody dynamics library widely used in biomechanical and robotic applications. PMID:27547093

CS-duration and partial-reinforcement effects counteract overshadowing in select situations

PubMed Central

Urushihara, Kouji; Miller, Ralph R.

2008-01-01

Two experiments used rats in a conditioned lick suppression preparation to investigate how the conditioned stimulus (CS)-duration and partial-reinforcement effects (i.e., weakened responding due to conditioning with a CS of longer duration and presenting nonreinforced CSs intermingled with CS-unconditioned stimulus [US] pairings, respectively) interact with overshadowing. Experiment 1 found that when overshadowing treatment was combined with either extended CS duration or partial reinforcement, the response deficit was weaker than when either of these three treatments was administered alone. In Experiment 2, the generality of the findings in Experiment 1 was investigated by replicating it with various US-US intervals. This time counteraction was observed only when both the absolute duration of total CS exposure and the US-US interval were short. The results support neither the view that the ratio between the total CS exposure and total time in the context determines the CS-duration and the partial-reinforcement effects nor the view that these two effects arise from a loss of effectiveness of the excitatory CS-US association during CS-alone exposures in partial reinforcement or early periods of CS exposure with long CSs. PMID:18047218

Comparison of different extenders on the recovery and longevity of epididymal sperm from Spix's yellow-toothed cavies (Galea spixii Wagler, 1831).

PubMed

da Silva, Andréia Maria; Sousa, Patrícia Cunha; Campos, Lívia Batista; Bezerra, José Artur Brilhante; de Araújo Lago, Arthur Emannuel; de Oliveira, Moacir Franco; Silva, Alexandre Rodrigues

2017-04-01

The aim of this study was to evaluate the performance of cavy (Galea spixii) epididymal sperm following addition to TES or TRIS extenders and using a thermal resistance test (TRT), as well as fluorescence analysis as a complementary method to predict the viability of these gametes. Nine testicle-epididymis complexes were used for sperm collection using a flotation method. Epididymis tails were sliced and one was immersed in 3 ml of TRIS buffer, and the other in 3 ml of TES, for 5 min. After sperm recovery, the samples were subjected to a TRT which involved incubation in a water bath at 37°C for 3 h. During incubation, sample parameters were assessed at 0, 15, 30, 60, 90, 120, 150 or 180 min intervals. Results indicated that the TRIS diluent was more efficient than TES (P < 0.05) for the maintenance of sperm parameters in Spix's yellow-toothed cavies over the whole TRT, maintaining sperm longevity for an extended time. In conclusion, we indicate the use of TRIS diluent for recovery and maintenance of longevity of epididymal sperm from cavies (G. spixii).

Evaluation about the performance of E-government based on interval-valued intuitionistic fuzzy set.

PubMed

Zhang, Shuai; Yu, Dejian; Wang, Yan; Zhang, Wenyu

2014-01-01

The evaluation is an important approach to promote the development of the E-Government. Since the rapid development of E-Government in the world, the E-Government performance evaluation has become a hot issue in the academia. In this paper, we develop a new evaluation method for the development of the E-Government based on the interval-valued intuitionistic fuzzy set which is a powerful technique in expressing the uncertainty of the real situation. First, we extend the geometric Heronian mean (GHM) operator to interval-valued intuitionistic fuzzy environment and proposed the interval-valued intuitionistic fuzzy GHM (IIFGHM) operator. Then, we investigate the relationships between the IIFGHM operator and some existing ones, such as generalized interval-valued intuitionistic fuzzy HM (GIIFHM) and interval-valued intuitionistic fuzzy weighted Bonferoni mean operator. Furthermore, we validate the effectiveness of the proposed method using a real case about the E-Government evaluation in Hangzhou City, China.

Power of magic hands: parent-driven application of habit reversal to treat complex stereotypy in a 3-year-old.

PubMed

Freeman, Kurt A; Duke, Danny C

2013-08-01

The authors assessed the effectiveness of habit reversal training (HRT) to treat a complex motor stereotypy in a healthy 3-year-old female. This data-based case study involved training parents in HRT to deliver the parent-driven intervention to the child. The frequency of the child's behaviors was estimated daily in 30-min intervals by her parents. Outcomes supported the effectiveness of the intervention, with the estimated frequency of the stereotypy decreasing from occurring during approximately 85% of recorded intervals to less than 2% over a period of 4 weeks. Further record keeping over 19 weeks suggested treatment gains were generally maintained over time. The current case study provides preliminary evidence supporting the effectiveness of modified HRT to reduce stereotypies in young children. Further, data suggest that the intervention may be extended to younger ages by teaching parents how to facilitate treatment delivery. PsycINFO Database Record (c) 2013 APA, all rights reserved.

The Extended Contact Hypothesis: A Meta-Analysis on 20 Years of Research.

PubMed

Zhou, Shelly; Page-Gould, Elizabeth; Aron, Arthur; Moyer, Anne; Hewstone, Miles

2018-04-01

According to the extended contact hypothesis, knowing that in-group members have cross-group friends improves attitudes toward this out-group. This meta-analysis covers the 20 years of research that currently exists on the extended contact hypothesis, and consists of 248 effect sizes from 115 studies. The aggregate relationship between extended contact and intergroup attitudes was r = .25, 95% confidence interval (CI) = [.22, .27], which reduced to r = .17, 95% CI = [.14, .19] after removing direct friendship's contribution; these results suggest that extended contact's hypothesized relationship to intergroup attitudes is small-to-medium and exists independently of direct friendship. This relationship was larger when extended contact was perceived versus actual, highlighting the importance of perception in extended contact. Current results on extended contact mostly resembled their direct friendship counterparts, suggesting similarity between these contact types. These unique insights about extended contact and its relationship with direct friendship should enrich and spur growth within this literature.

Wing Infrastructure and Development Outlook (WINDO) Final Environmental Assessment

DTIC Science & Technology

2006-06-01

installation, and repair F Construct revetment , paint taxi lines, install runway shoulders, extend/repair flight line, maintain airfield pavement...RKMF990065 CONSTRUCT CHAPEL MEETING FAC C RKMF000041 CONSTRUCT REVETMENT LOLA SUPPORT FAC F RKMF010042 CONSTRUCT SHOULDERS RUNWAY 03L/21R F RKMF030054...100-foot transect intervals. Sampling utilized 100- foot intervals in blocks . Isolate artifacts were recorded on site forms until 1996. They were

The Effects of Intertrial Interval and Instructional Format on Skill Acquisition and Maintenance for Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Cariveau, Tom; Kodak, Tiffany; Campbell, Vincent

2016-01-01

We replicated and extended the study by Koegel, Dunlap, and Dyer (1980) by examining the effects of 3 intertrial-interval (ITI) durations on skill acquisition in 2 children with autism spectrum disorders. Specifically, we compared the effect of short (2 s), progressive (2 s to 20 s), and long (20 s) ITIs on participants' mastery of tacts or…

Sea-level evaluation of digitally implemented turbojet engine control functions

NASA Technical Reports Server (NTRS)

Arpasi, D. J.; Cwynar, D. S.; Wallhagen, R. E.

1972-01-01

The standard hydromechanical control system of a turbojet engine was replaced with a digital control system that implemented the same control laws. A detailed discussion of the digital control system in use with the engine is presented. The engine was operated in a sea-level test stand. The effects of control update interval are defined, and a method for extending this interval by using digital compensation is discussed.

Chirped frequency transfer: a tool for synchronization and time transfer.

PubMed

Raupach, Sebastian M F; Grosche, Gesine

2014-06-01

We propose and demonstrate the phase-stabilized transfer of a chirped frequency as a tool for synchronization and time transfer. Technically, this is done by evaluating remote measurements of the transferred, chirped frequency. The gates of the frequency counters, here driven by a 10-MHz oscillation derived from a hydrogen maser, play a role analogous to the 1-pulse per second (PPS) signals usually employed for time transfer. In general, for time transfer, the gates consequently must be related to the external clock. Synchronizing observations based on frequency measurements, on the other hand, only requires a stable oscillator driving the frequency counters. In a proof of principle, we demonstrate the suppression of symmetrical delays, such as the geometrical path delay. We transfer an optical frequency chirped by around 240 kHz/s over a fiber link of around 149 km. We observe an accuracy and simultaneity, as well as a precision (Allan deviation, 18,000 s averaging interval) of the transferred frequency of around 2 × 10(-19). We apply chirped frequency transfer to remote measurements of the synchronization between two counters' gate intervals. Here, we find a precision of around 200 ps at an estimated overall uncertainty of around 500 ps. The measurement results agree with those obtained from reference measurements, being well within the uncertainty. In the present setup, timing offsets up to 4 min can be measured unambiguously. We indicate how this range can be extended further.

THE TIME INTERVAL AFTER PULSED IRRADIATION WITHIN WHICH INJURY TO BACTERIA CAN BE MODIFIED BY DISSOLVED OXYGEN. I. A SEARCH FOR AN EFFECT OF OXYGEN 0.02 SECOND AFTER PULSED IRRADIATION. II. THE HYPOTHESIS THAT THE OXYGEN EFFECT INVOLVES A CARBON RADICAL: AND THE TIME TAKEN BY OXYGEN TO DIFFUSE TO AND REACT WITH SUCH A RADICAL

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

Howard-Flanders, P.; Moore, D.

1958-10-01

An investigation was made of the radiosensitivity of the dysentery bacillus Shigella flexneri to a shcrt pulsed irradiation with 1.2-Mev electrons delivered either before or after a sudden change in oxygen pressure. Results show that the stage in the development of the radiation injury at which oxygen may intervene does not extend for as long as 0.01 second after irradiation. The nature of this stage was investigated and an hypothesis is presented for the mechanism of radiation injury. (C.H.)

The mass of (1) Ceres from perturbations on (348) May

NASA Technical Reports Server (NTRS)

Williams, Gareth V.

1992-01-01

The most promising ground-based technique for determining the mass of a minor planet is the observation of the perturbations it induces in the motion of another minor planet. This method requires careful observation of both minor planets over extended periods of time. The mass of (1) Ceres has been determined from the perturbations on (348) May, which made three close approaches to Ceres at intervals of 46 years between 1891 and 1984. The motion of May is clearly influenced by Ceres, and by using different test masses for Ceres, a search was made to determine the mass of Ceres that minimizes the residuals in the observations of May.

Extended follow-up confirms early vaccine-enhanced risk of HIV acquisition and demonstrates waning effect over time among participants in a randomized trial of recombinant adenovirus HIV vaccine (Step Study).

PubMed

Duerr, Ann; Huang, Yunda; Buchbinder, Susan; Coombs, Robert W; Sanchez, Jorge; del Rio, Carlos; Casapia, Martin; Santiago, Steven; Gilbert, Peter; Corey, Lawrence; Robertson, Michael N

2012-07-15

The Step Study tested whether an adenovirus serotype 5 (Ad5)-vectored human immunodeficiency virus (HIV) vaccine could prevent HIV acquisition and/or reduce viral load set-point after infection. At the first interim analysis, nonefficacy criteria were met. Vaccinations were halted; participants were unblinded. In post hoc analyses, more HIV infections occurred in vaccinees vs placebo recipients in men who had Ad5-neutralizing antibodies and/or were uncircumcised. Follow-up was extended to assess relative risk of HIV acquisition in vaccinees vs placebo recipients over time. We used Cox proportional hazard models for analyses of vaccine effect on HIV acquisition and vaccine effect modifiers, and nonparametric and semiparametric methods for analysis of constancy of relative risk over time. One hundred seventy-two of 1836 men were infected. The adjusted vaccinees vs placebo recipients hazard ratio (HR) for all follow-up time was 1.40 (95% confidence interval [CI], 1.03-1.92; P= .03). Vaccine effect differed by baseline Ad5 or circumcision status during first 18 months, but neither was significant for all follow-up time. The HR among uncircumcised and/or Ad5-seropositive men waned with time since vaccination. No significant vaccine-associated risk was seen among circumcised, Ad5-negative men (HR, 0.97; P=1.0) over all follow-up time. The vaccine-associated risk seen in interim analysis was confirmed but waned with time from vaccination.

21 CFR 526.1810 - Pirlimycin.

Code of Federal Regulations, 2011 CFR

2011-04-01

... be used for food regardless of treatment duration. Following infusion twice at a 24-hour interval, treated animals must not be slaughtered for 9 days. Following any extended duration of therapy (infusion...

Statistics of return intervals between long heartbeat intervals and their usability for online prediction of disorders

NASA Astrophysics Data System (ADS)

Bogachev, Mikhail I.; Kireenkov, Igor S.; Nifontov, Eugene M.; Bunde, Armin

2009-06-01

We study the statistics of return intervals between large heartbeat intervals (above a certain threshold Q) in 24 h records obtained from healthy subjects. We find that both the linear and the nonlinear long-term memory inherent in the heartbeat intervals lead to power-laws in the probability density function PQ(r) of the return intervals. As a consequence, the probability WQ(t; Δt) that at least one large heartbeat interval will occur within the next Δt heartbeat intervals, with an increasing elapsed number of intervals t after the last large heartbeat interval, follows a power-law. Based on these results, we suggest a method of obtaining a priori information about the occurrence of the next large heartbeat interval, and thus to predict it. We show explicitly that the proposed method, which exploits long-term memory, is superior to the conventional precursory pattern recognition technique, which focuses solely on short-term memory. We believe that our results can be straightforwardly extended to obtain more reliable predictions in other physiological signals like blood pressure, as well as in other complex records exhibiting multifractal behaviour, e.g. turbulent flow, precipitation, river flows and network traffic.

HPV vaccination impact on a cervical cancer screening program: methods of the FASTER-Tlalpan Study in Mexico.

PubMed

Salmerón, Jorge; Torres-Ibarra, Leticia; Bosch, F Xavier; Cuzick, Jack; Lörincz, Attila; Wheeler, Cosette M; Castle, Philip E; Robles, Claudia; Lazcano-Ponce, Eduardo

2016-04-01

To outline the design of a clinical trial to evaluate the impact of HPV vaccination as part of a hrHPV-based primary screening program to extend screening intervals. A total of 18,000 women aged 25-45 years, attending the regular cervical cancer-screening program in primary health care services in Tlalpan, Mexico City, will be invited to the study. Eligible participants will be assigned to one of three comparison groups: 1) HPV16/18 vaccine and hrHPV-based screening; 2) HPV6/11/16/18 vaccine and hrHPV-based screening; 3) Control group who will receive only hrHPV-based screening. Strict surveillance of hrHPV persistent infection and occurrence of precancerous lesions will be conducted to estimate safety profiles at different screening intervals; participants will undergo diagnosis confirmation and treatment as necessary. The FASTER-Tlalpan Study will provide insights into new approaches of cervical cancer prevention programs. It will offer valuable information on potential benefits of combining HPV vaccination and hrHPV-based screening to safety extend screening intervals.

Discrimination of edible oils and fats by combination of multivariate pattern recognition and FT-IR spectroscopy: a comparative study between different modeling methods.

PubMed

Javidnia, Katayoun; Parish, Maryam; Karimi, Sadegh; Hemmateenejad, Bahram

2013-03-01

By using FT-IR spectroscopy, many researchers from different disciplines enrich the experimental complexity of their research for obtaining more precise information. Moreover chemometrics techniques have boosted the use of IR instruments. In the present study we aimed to emphasize on the power of FT-IR spectroscopy for discrimination between different oil samples (especially fat from vegetable oils). Also our data were used to compare the performance of different classification methods. FT-IR transmittance spectra of oil samples (Corn, Colona, Sunflower, Soya, Olive, and Butter) were measured in the wave-number interval of 450-4000 cm(-1). Classification analysis was performed utilizing PLS-DA, interval PLS-DA, extended canonical variate analysis (ECVA) and interval ECVA methods. The effect of data preprocessing by extended multiplicative signal correction was investigated. Whilst all employed method could distinguish butter from vegetable oils, iECVA resulted in the best performances for calibration and external test set with 100% sensitivity and specificity. Copyright © 2012 Elsevier B.V. All rights reserved.

Cigarette smoke chemistry market maps under Massachusetts Department of Public Health smoking conditions.

PubMed

Morton, Michael J; Laffoon, Susan W

2008-06-01

This study extends the market mapping concept introduced by Counts et al. (Counts, M.E., Hsu, F.S., Tewes, F.J., 2006. Development of a commercial cigarette "market map" comparison methodology for evaluating new or non-conventional cigarettes. Regul. Toxicol. Pharmacol. 46, 225-242) to include both temporal cigarette and testing variation and also machine smoking with more intense puffing parameters, as defined by the Massachusetts Department of Public Health (MDPH). The study was conducted over a two year period and involved a total of 23 different commercial cigarette brands from the U.S. marketplace. Market mapping prediction intervals were developed for 40 mainstream cigarette smoke constituents and the potential utility of the market map as a comparison tool for new brands was demonstrated. The over-time character of the data allowed for the variance structure of the smoke constituents to be more completely characterized than is possible with one-time sample data. The variance was partitioned among brand-to-brand differences, temporal differences, and the remaining residual variation using a mixed random and fixed effects model. It was shown that a conventional weighted least squares model typically gave similar prediction intervals to those of the more complicated mixed model. For most constituents there was less difference in the prediction intervals calculated from over-time samples and those calculated from one-time samples than had been anticipated. One-time sample maps may be adequate for many purposes if the user is aware of their limitations. Cigarette tobacco fillers were analyzed for nitrate, nicotine, tobacco-specific nitrosamines, ammonia, chlorogenic acid, and reducing sugars. The filler information was used to improve predicting relationships for several of the smoke constituents, and it was concluded that the effects of filler chemistry on smoke chemistry were partial explanations of the observed brand-to-brand variation.

The direct and indirect costs of Dravet Syndrome.

PubMed

Whittington, Melanie D; Knupp, Kelly G; Vanderveen, Gina; Kim, Chong; Gammaitoni, Arnold; Campbell, Jonathan D

2018-03-01

The objective of this study was to estimate the annual direct and indirect costs associated with Dravet Syndrome (DS). A survey was electronically administered to the caregivers of patients with DS treated at Children's Hospital Colorado. Survey domains included healthcare utilization of the patient with DS and DS caregiver work productivity and activity impairment. Patient healthcare utilization was measured using modified questions from the National Health Interview Survey; caregiver work productivity and activity impairment were measured using modified questions from the Work Productivity and Activity Impairment questionnaire. Direct costs were calculated by multiplying the caregiver-reported healthcare utilization rates by the mean unit cost for each healthcare utilization category. Indirect costs included lost productivity, income loss, and lost leisure time. The indirect costs were a function of caregiver-reported hours spent caregiving and an hourly unit cost. The survey was emailed to 60 DS caregivers, of which 34 (57% response rate) responded. Direct costs on average were $27,276 (95% interval: $15,757, $41,904) per patient with DS. Hospitalizations ($11,565 a year) and in-home medical care visits ($9894 a year) were substantial cost drivers. Additionally, caregivers reported extensive time spent providing care to an individual with DS. This caregiver time resulted in average annual indirect costs of $81,582 (95% interval: $57,253, $110,151), resulting in an average total annual financial burden of $106,378 (95% interval: $78,894, $137,906). Dravet Syndrome results in substantial healthcare utilization, financial burden, and time commitment. Establishing evidence on the financial burden of DS is essential to understanding the overall impact of DS, identifying potential areas for support needs, and assessing the impact of novel treatments as they become available. Based on the study findings, in-home visits, hospitalizations, and lost productivity and leisure time of caregivers are key domains for DS economic evaluations. Future research should extend these estimates to include the potential additional healthcare utilization of the DS caregiver. Copyright © 2018 Elsevier Inc. All rights reserved.

Fractal structure of the interplanetary magnetic field

NASA Technical Reports Server (NTRS)

Burlaga, L. F.; Klein, L. W.

1985-01-01

Under some conditions, time series of the interplanetary magnetic field strength and components have the properties of fractal curves. Magnetic field measurements made near 8.5 AU by Voyager 2 from June 5 to August 24, 1981 were self-similar over time scales from approximately 20 sec to approximately 3 x 100,000 sec, and the fractal dimension of the time series of the strength and components of the magnetic field was D = 5/3, corresponding to a power spectrum P(f) approximately f sup -5/3. Since the Kolmogorov spectrum for homogeneous, isotropic, stationary turbulence is also f sup -5/3, the Voyager 2 measurements are consistent with the observation of an inertial range of turbulence extending over approximately four decades in frequency. Interaction regions probably contributed most of the power in this interval. As an example, one interaction region is discussed in which the magnetic field had a fractal dimension D = 5/3.

Translation Invariant Extensions of Finite Volume Measures

NASA Astrophysics Data System (ADS)

Goldstein, S.; Kuna, T.; Lebowitz, J. L.; Speer, E. R.

2017-02-01

We investigate the following questions: Given a measure μ _Λ on configurations on a subset Λ of a lattice L, where a configuration is an element of Ω ^Λ for some fixed set Ω , does there exist a measure μ on configurations on all of L, invariant under some specified symmetry group of L, such that μ _Λ is its marginal on configurations on Λ ? When the answer is yes, what are the properties, e.g., the entropies, of such measures? Our primary focus is the case in which L=Z^d and the symmetries are the translations. For the case in which Λ is an interval in Z we give a simple necessary and sufficient condition, local translation invariance ( LTI), for extendibility. For LTI measures we construct extensions having maximal entropy, which we show are Gibbs measures; this construction extends to the case in which L is the Bethe lattice. On Z we also consider extensions supported on periodic configurations, which are analyzed using de Bruijn graphs and which include the extensions with minimal entropy. When Λ subset Z is not an interval, or when Λ subset Z^d with d>1, the LTI condition is necessary but not sufficient for extendibility. For Z^d with d>1, extendibility is in some sense undecidable.

Autonomic specificity of basic emotions: evidence from pattern classification and cluster analysis.

PubMed

Stephens, Chad L; Christie, Israel C; Friedman, Bruce H

2010-07-01

Autonomic nervous system (ANS) specificity of emotion remains controversial in contemporary emotion research, and has received mixed support over decades of investigation. This study was designed to replicate and extend psychophysiological research, which has used multivariate pattern classification analysis (PCA) in support of ANS specificity. Forty-nine undergraduates (27 women) listened to emotion-inducing music and viewed affective films while a montage of ANS variables, including heart rate variability indices, peripheral vascular activity, systolic time intervals, and electrodermal activity, were recorded. Evidence for ANS discrimination of emotion was found via PCA with 44.6% of overall observations correctly classified into the predicted emotion conditions, using ANS variables (z=16.05, p<.001). Cluster analysis of these data indicated a lack of distinct clusters, which suggests that ANS responses to the stimuli were nomothetic and stimulus-specific rather than idiosyncratic and individual-specific. Collectively these results further confirm and extend support for the notion that basic emotions have distinct ANS signatures. Copyright © 2010 Elsevier B.V. All rights reserved.

Reinforcement: Food Signals the Time and Location of Future Food

PubMed Central

Cowie, Sarah; Davison, Michael; Elliffe, Douglas

2011-01-01

It has long been understood that food deliveries may act as signals of future food location, and not only as strengtheners of prefood responding as the law of effect suggests. Recent research has taken this idea further—the main effect of food deliveries, or other “reinforcers”, may be signaling rather than strengthening. The present experiment investigated the ability of food deliveries to signal food contingencies across time after food. In Phase 1, the next food delivery was always equally likely to be arranged for a left- or a right-key response. Conditions were arranged such that the next food delivery was likely to occur either sooner on the left (or right) key, or sooner on the just-productive (or not-just-productive) key. In Phase 2, similar contingencies were arranged, but the last-food location was signaled by a red keylight. Preference, measured in 2-s bins across interfood intervals, was jointly controlled by the likely time and location of the next food delivery. In Phase 1, when any food delivery signaled a likely sooner next food delivery on a particular key, postfood preference was strongly toward that key, and moved toward the other key across the interreinforcer interval. In other conditions in which food delivery on the two keys signaled different subsequent contingencies, postfood preference was less extreme, and quickly moved toward indifference. In Phase 2, in all three conditions, initial preference was strongly toward the likely-sooner food key, and moved to the other key across the interfood interval. In both phases, at a more extended level of analysis, sequences of same-key food deliveries caused a small increase in preference for the just-productive key, suggesting the presence of a “reinforcement effect”, albeit one that was very small. PMID:21765546

Study of continuous blood pressure estimation based on pulse transit time, heart rate and photoplethysmography-derived hemodynamic covariates.

PubMed

Feng, Jingjie; Huang, Zhongyi; Zhou, Congcong; Ye, Xuesong

2018-06-01

It is widely recognized that pulse transit time (PTT) can track blood pressure (BP) over short periods of time, and hemodynamic covariates such as heart rate, stiffness index may also contribute to BP monitoring. In this paper, we derived a proportional relationship between BP and PPT -2 and proposed an improved method adopting hemodynamic covariates in addition to PTT for continuous BP estimation. We divided 28 subjects from the Multi-parameter Intelligent Monitoring for Intensive Care database into two groups (with/without cardiovascular diseases) and utilized a machine learning strategy based on regularized linear regression (RLR) to construct BP models with different covariates for corresponding groups. RLR was performed for individuals as the initial calibration, while recursive least square algorithm was employed for the re-calibration. The results showed that errors of BP estimation by our method stayed within the Association of Advancement of Medical Instrumentation limits (- 0.98 ± 6.00 mmHg @ SBP, 0.02 ± 4.98 mmHg @ DBP) when the calibration interval extended to 1200-beat cardiac cycles. In comparison with other two representative studies, Chen's method kept accurate (0.32 ± 6.74 mmHg @ SBP, 0.94 ± 5.37 mmHg @ DBP) using a 400-beat calibration interval, while Poon's failed (- 1.97 ± 10.59 mmHg @ SBP, 0.70 ± 4.10 mmHg @ DBP) when using a 200-beat calibration interval. With additional hemodynamic covariates utilized, our method improved the accuracy of PTT-based BP estimation, decreased the calibration frequency and had the potential for better continuous BP estimation.

Revising the "Rule of Three" for inferring seizure freedom.

PubMed

Westover, M Brandon; Cormier, Justine; Bianchi, Matt T; Shafi, Mouhsin; Kilbride, Ronan; Cole, Andrew J; Cash, Sydney S

2012-02-01

How long after starting a new medication must a patient go without seizures before they can be regarded as seizure-free? A recent International League Against Epilepsy (ILAE) task force proposed using a "Rule of Three" as an operational definition of seizure freedom, according to which a patient should be considered seizure-free following an intervention after a period without seizures has elapsed equal to three times the longest preintervention interseizure interval over the previous year. This rule was motivated in large part by statistical considerations advanced in a classic 1983 paper by Hanley and Lippman-Hand. However, strict adherence to the statistical logic of this rule generally requires waiting much longer than recommended by the ILAE task force. Therefore, we set out to determine whether an alternative approach to the Rule of Three might be possible, and under what conditions the rule may be expected to hold or would need to be extended. Probabilistic modeling and application of Bayes' rule. We find that an alternative approach to the problem of inferring seizure freedom supports using the Rule of Three in the way proposed by the ILAE in many cases, particularly in evaluating responses to a first trial of antiseizure medication, and to favorably-selected epilepsy surgical candidates. In cases where the a priori odds of success are less favorable, our analysis requires longer seizure-free observation periods before declaring seizure freedom, up to six times the average preintervention interseizure interval. The key to our approach is to take into account not only the time elapsed without seizures but also empirical data regarding the a priori probability of achieving seizure freedom conferred by a particular intervention. In many cases it may be reasonable to consider a patient seizure-free after they have gone without seizures for a period equal to three times the preintervention interseizure interval, as proposed on pragmatic grounds in a recent ILAE position paper, although in other commonly encountered cases a waiting time up to six times this interval is required. In this work we have provided a coherent theoretical basis for modified criterion for seizure freedom, which we call the "Rule of Three-To-Six." Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.

Revising the Rule Of Three For Inferring Seizure Freedom

PubMed Central

Westover, M. Brandon; Cormier, Justine; Bianchi, Matt T.; Shafi, Mouhsin; Kilbride, Ronan; Cole, Andrew J.; Cash, Sydney S.

2011-01-01

Summary Purpose How long after starting a new medication must a patient go without seizures before they can be regarded as seizure free? A recent ILAE task force proposed using a “Rule of Three” as an operational definition of seizure freedom, according to which a patient should be considered seizure-free following an intervention after a period without seizures has elapsed equal to three times the longest pre-intervention inter-seizure interval over the previous year. This rule was motivated in large part by statistical considerations advanced in a classic 1983 paper by Hanley and Lippman-Hand. However, strict adherence to the statistical logic of this rule generally requires waiting much longer than recommended by the ILAE task force. Therefore, we set out to determine whether an alternative approach to the Rule of Three might be possible, and under what conditions the rule may be expected to hold or would need to be extended. Methods Probabilistic modeling and application of Bayes’ rule. Key Findings We find that an alternative approach to the problem of inferring seizure freedom supports using the Rule of Three in the way proposed by the ILAE in many cases, particularly in evaluating responses to a first trial of anti-seizure medication, and to favorably-selected epilepsy surgical candidates. In cases where the a priori odds of success are less favorable, our analysis requires longer seizure-free observation periods before declaring seizure freedom, up to six times the average pre-intervention insterseizure interval. The key to our approach is to take into account not only the time elapsed without seizures but also empirical data regarding the a priori probability of achieving seizure freedom conferred by a particular intervention. Significance In many cases it may be reasonable to consider a patient seizure free after they have gone without seizures for a period equal to three times the pre-intervention inter-seizure interval, as proposed on pragmatic grounds in a recent ILAE position paper, though in other commonly encountered cases a waiting time up to six times this interval is required. In this work we have provided a coherent theoretical basis for modified criterion for seizure freedom, which we call the “Rule of Three-To-Six”. PMID:22191711

The role of topotecan for extending the platinum-free interval in recurrent ovarian cancer: an in vitro model.

PubMed

Horowitz, Neil S; Hua, Jun; Gibb, Randall K; Mutch, David G; Herzog, Thomas J

2004-07-01

Topotecan, a novel topoisomerase-I inhibitor, is an active agent of second-line chemotherapy for extending the platinum-free interval (PFI) and improving the chances of a response to platinum in recurrent ovarian cancer patients. The aim of this study was to understand the molecular mechanism of topotecan-based second-line chemotherapy through an in vitro cell culture model and to gain clinical insight into sequencing issues for second-line treatment with novel agents versus retreatment with platinum. The human ovarian cancer cell line A2780 and the cisplatin resistance cell line A2780-CR were separately seeded in 6-well cell culture plates and then exposed to multiple concentrations of cisplatin plus paclitaxel or topotecan for 7 days. Surviving cells were recovered and cultured in drug-free media for 3 weeks and then replated in a 96-well microtiter plate. The LD(50) for these cells was determined by a cytotoxic MTT assay after exposure to multiple clinically relevant concentrations of cisplatin or topotecan. Surviving cells were cultured in drug-free media for an additional 4 weeks at which time the LD(50) was reassessed for each cell population by a second MTT assay. Using RT-PCR and Northern blot hybridization to measure mRNA expression, the molecular profile of these cells in terms of resistance was evaluated for the multidrug-resistant gene (MDR-1), multidrug-resistant protein (MRP), Topoisomerase-I, and beta-Actin. The LD(50) to cisplatin was unchanged in A2780-CR cells treated by topotecan. Those A2780-CR cells originally exposed to higher concentrations of cisplatin became more resistant to cisplatin in the MTT assays, while those A2780-CR cell lines treated with a combination of lower cisplatin concentrations and paclitaxel became more sensitive to cisplatin in the MTT assay (P < 0.01). The second MTT assay demonstrated that the LD(50) for cisplatin in every cell line decreased significantly after a 4-week drug-free interval (P < 0.01). There was no difference in the mRNA expression for MRP or topoisomerase-I regardless of cell line, or type or concentration of chemotherapeutic exposure. The mRNA for MDR-1 was uniquely overexpressed in the cisplatin-resistant cell line A2780-CR9 initially treated with low doses of cisplatin and paclitaxel, but was not amplified in A2780 (P < 0.01). The acquired resistance to cisplatin in A2780 is potentially due to P-glycoprotein-mediated multidrug resistance. This acquired resistance to cisplatin is an unstable phenotype in that some cell populations become sensitive after a drug-free interval and topotecan treatment. This reversal of resistance, however, does not appear to be simply due to loss of MDR-1 expression. While in vivo confirmation is required, agents with novel mechanisms of action offer a strategy to extend the platinum-free interval and thereby improve survival in patients with recurrent ovarian cancer.

Variations of melatonin and stress hormones under extended shifts and radiofrequency electromagnetic radiation.

PubMed

Vangelova, Katia Koicheva; Israel, Mishel Salvador

2005-01-01

We studied the time-of-day variations in urinary levels of 6-sulphatoxy-melatonin and three stress hormones in operators working fast-rotating extended shifts under radiofrequency electromagnetic radiation (EMR). The excretion rate of the hormones was monitored by radioimmunoassay and spectrofluorimetry at 4-hour intervals in a group of 36 male operators comprising 12 broadcasting station operators, 12 TV station operators, and a control group of 12 satellite station operators. Measuring the time-weighted average (TWA) of EMR exposure revealed a high-level of exposure in broadcasting station operators (TWAmean= 3.10 microW/ cm2, TWAmax = 137.00 microW/cm2), a low-level in TV station operators (TWAmean = 1.89 microW/cm2, TWAmax = 5.24 microW/cm2), and a very low level in satellite station operators. The differences among the groups remained the same after confounding factors were taken into account. Radiofrequency EMR had no effect on the typical diurnal pattern of 6-sulphatoxymelatonin. High-level radiofrequency EMR exposure significantly increased the excretion rates of cortisol (p < 0.001), adrenaline (p = 0.028), and noradrenaline (p < 0.000), whereas changes under low-level exposure did not reach significance. The 24-hour excretion of cortisol and noradrenaline correlated with TWAmean and TWAmax. In conclusion, the excretion of 6-sulphatoxymelatonin retained a typical diurnal pattern under fast-rotating extended shifts and radiofrequency EMR, but showed an exposure-effect relation with stress hormones.

GIGGLE: a search engine for large-scale integrated genome analysis.

PubMed

Layer, Ryan M; Pedersen, Brent S; DiSera, Tonya; Marth, Gabor T; Gertz, Jason; Quinlan, Aaron R

2018-02-01

GIGGLE is a genomics search engine that identifies and ranks the significance of genomic loci shared between query features and thousands of genome interval files. GIGGLE (https://github.com/ryanlayer/giggle) scales to billions of intervals and is over three orders of magnitude faster than existing methods. Its speed extends the accessibility and utility of resources such as ENCODE, Roadmap Epigenomics, and GTEx by facilitating data integration and hypothesis generation.

GIGGLE: a search engine for large-scale integrated genome analysis

PubMed Central

Layer, Ryan M; Pedersen, Brent S; DiSera, Tonya; Marth, Gabor T; Gertz, Jason; Quinlan, Aaron R

2018-01-01

GIGGLE is a genomics search engine that identifies and ranks the significance of genomic loci shared between query features and thousands of genome interval files. GIGGLE (https://github.com/ryanlayer/giggle) scales to billions of intervals and is over three orders of magnitude faster than existing methods. Its speed extends the accessibility and utility of resources such as ENCODE, Roadmap Epigenomics, and GTEx by facilitating data integration and hypothesis generation. PMID:29309061

Cycle control with an extended-regimen oral contraceptive combining levonorgestrel and ethinyl estradiol that includes continuous low-dose ethinyl estradiol instead of the traditional hormone-free interval.

PubMed

Nappi, Rossella E; Lobo Abascal, Paloma; Hsieh, Jennifer; Micheletti, Marie-Christine

2017-01-01

To evaluate scheduled and unscheduled bleeding and spotting over 1 year of treatment with 91-day extended-regimen combined oral contraception (COC) providing continuous low-dose ethinyl estradiol (EE) in place of the traditional 7-day hormone-free interval (HFI). This post hoc analysis of a multicenter, open-label, 1-year, Phase 3 study of extended-regimen COC with 30 µg EE/150 µg levonorgestrel (LNG) for 84 days and EE 10 µg for 7 days included 799 sexually active, adult women who completed at least one 91-day cycle of therapy. Subjects recorded bleeding and spotting episodes daily using electronic diaries. Logistic regression analyses are reported as ORs with 95% CIs. There was a 10% increase (OR =1.102; 95% CI: 1.006-1.206) in the likelihood of reporting no scheduled bleeding for each additional 91-day cycle completed. From the third 91-day cycle, more than one fifth of women reported no scheduled bleeding (third cycle =23% [121/533]; fourth cycle =22% [97/446]). Among women who reported no scheduled bleeding at Cycle 1 (136/758 [18%]), ≥45% showed sustained lack of scheduled bleeding in later cycles. There were increases of 53% (OR =1.531; 95% CI: 1.393-1.683) and 31% (OR =1.307; 95% CI: 1.205-1.418) in the likelihood of reporting 0 to ≤6 days vs >6 days of unscheduled bleeding and spotting, respectively, for each additional 91-day cycle. By Cycle 2, more than 80% of women reported no unscheduled bleeding or ≤6 days of unscheduled bleeding during each 91-day cycle. Improved cycle control with decreased bleeding over time was shown during extended-regimen COC with 30 µg EE/150 µg LNG for 84 days and continuous low-dose EE instead of the traditional 7-day HFI. Women considering this regimen should be informed that those who complete at least one 91-day COC cycle will likely experience less bleeding/spotting in future cycles.

Cycle control with an extended-regimen oral contraceptive combining levonorgestrel and ethinyl estradiol that includes continuous low-dose ethinyl estradiol instead of the traditional hormone-free interval

PubMed Central

Nappi, Rossella E; Lobo Abascal, Paloma; Hsieh, Jennifer; Micheletti, Marie-Christine

2017-01-01

Purpose To evaluate scheduled and unscheduled bleeding and spotting over 1 year of treatment with 91-day extended-regimen combined oral contraception (COC) providing continuous low-dose ethinyl estradiol (EE) in place of the traditional 7-day hormone-free interval (HFI). Patients and methods This post hoc analysis of a multicenter, open-label, 1-year, Phase 3 study of extended-regimen COC with 30 µg EE/150 µg levonorgestrel (LNG) for 84 days and EE 10 µg for 7 days included 799 sexually active, adult women who completed at least one 91-day cycle of therapy. Subjects recorded bleeding and spotting episodes daily using electronic diaries. Logistic regression analyses are reported as ORs with 95% CIs. Results There was a 10% increase (OR =1.102; 95% CI: 1.006–1.206) in the likelihood of reporting no scheduled bleeding for each additional 91-day cycle completed. From the third 91-day cycle, more than one fifth of women reported no scheduled bleeding (third cycle =23% [121/533]; fourth cycle =22% [97/446]). Among women who reported no scheduled bleeding at Cycle 1 (136/758 [18%]), ≥45% showed sustained lack of scheduled bleeding in later cycles. There were increases of 53% (OR =1.531; 95% CI: 1.393–1.683) and 31% (OR =1.307; 95% CI: 1.205–1.418) in the likelihood of reporting 0 to ≤6 days vs >6 days of unscheduled bleeding and spotting, respectively, for each additional 91-day cycle. By Cycle 2, more than 80% of women reported no unscheduled bleeding or ≤6 days of unscheduled bleeding during each 91-day cycle. Conclusion Improved cycle control with decreased bleeding over time was shown during extended-regimen COC with 30 µg EE/150 µg LNG for 84 days and continuous low-dose EE instead of the traditional 7-day HFI. Women considering this regimen should be informed that those who complete at least one 91-day COC cycle will likely experience less bleeding/spotting in future cycles. PMID:29042818

21 CFR 526.1810 - Pirlimycin.

Code of Federal Regulations, 2010 CFR

2010-04-01

... regardless of treatment duration. Following infusion twice at a 24-hour interval, treated animals must not be slaughtered for 9 days. Following any extended duration of therapy (infusion longer than twice at a 24-hour...

International Space Station Major Constituent Analyzer On-Orbit Performance

NASA Technical Reports Server (NTRS)

Gardner, Ben D.; Erwin, Philip M.; Thoresen, Souzan; Granahan, John; Matty, Chris

2010-01-01

The Major Constituent Analyzer is a mass spectrometer based system that measures the major atmospheric constituents on the International Space Station. A number of limited-life components require periodic changeout, including the analyzer (ORU 02) and the verification gas assembly (ORU 08). The longest lasting ORU 02 was recently replaced after a record service length of 1033 days. The comparatively high performance duration may be attributable to a reduced inlet flow rate into the analyzer, resulting in increased ion pump lifetime; however, there may be other factors as well. A recent schedule slip for delivery of replacement verification gas led to a demonstration that the calibration interval could be extended on a short-term basis. An analysis of ORU 08 performance characteristics indicates that it is possible to temporarily extend the calibration interval from 6 weeks to 12 weeks if necessary.

Impact of Prompt Influenza Antiviral Treatment on Extended Care Needs After Influenza Hospitalization Among Community-Dwelling Older Adults.

PubMed

Chaves, Sandra S; Pérez, Alejandro; Miller, Lisa; Bennett, Nancy M; Bandyopadhyay, Ananda; Farley, Monica M; Fowler, Brian; Hancock, Emily B; Kirley, Pam Daily; Lynfield, Ruth; Ryan, Patricia; Morin, Craig; Schaffner, William; Sharangpani, Ruta; Lindegren, Mary Lou; Tengelsen, Leslie; Thomas, Ann; Hill, Mary B; Bradley, Kristy K; Oni, Oluwakemi; Meek, James; Zansky, Shelley; Widdowson, Marc-Alain; Finelli, Lyn

2015-12-15

Patients hospitalized with influenza may require extended care on discharge. We aimed to explore predictors for extended care needs and the potential mitigating effect of antiviral treatment among community-dwelling adults aged ≥ 65 years hospitalized with influenza. We used laboratory-confirmed influenza hospitalizations from 3 influenza seasons. Extended care was defined as new placement in a skilled nursing home/long-term/rehabilitation facility on hospital discharge. We focused on those treated with antiviral agents to explore the effect of early treatment on extended care and hospital length of stay using logistic regression and competing risk survival analysis, accounting for time from illness onset to hospitalization. Treatment was categorized as early (≤ 4 days) or late (>4 days) in reference to date of illness onset. Among 6593 community-dwelling adults aged ≥ 65 years hospitalized for influenza, 18% required extended care at discharge. The need for care increased with age and neurologic disorders, intensive care unit admission, and pneumonia were predictors of care needs. Early treatment reduced the odds of extended care after hospital discharge for those hospitalized ≤ 2 or >2 days from illness onset (adjusted odds ratio, 0.38 [95% confidence interval {CI}, .17-.85] and 0.75 [.56-.97], respectively). Early treatment was also independently associated with reduction in length of stay for those hospitalized ≤ 2 days from illness onset (adjusted hazard ratio, 1.81; 95% CI, 1.43-2.30) or >2 days (1.30; 1.20-1.40). Prompt antiviral treatment decreases the impact of influenza on older adults through shorten hospitalization and reduced extended care needs. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Human memory retrieval as Lévy foraging

NASA Astrophysics Data System (ADS)

Rhodes, Theo; Turvey, Michael T.

2007-11-01

When people attempt to recall as many words as possible from a specific category (e.g., animal names) their retrievals occur sporadically over an extended temporal period. Retrievals decline as recall progresses, but short retrieval bursts can occur even after tens of minutes of performing the task. To date, efforts to gain insight into the nature of retrieval from this fundamental phenomenon of semantic memory have focused primarily upon the exponential growth rate of cumulative recall. Here we focus upon the time intervals between retrievals. We expected and found that, for each participant in our experiment, these intervals conformed to a Lévy distribution suggesting that the Lévy flight dynamics that characterize foraging behavior may also characterize retrieval from semantic memory. The closer the exponent on the inverse square power-law distribution of retrieval intervals approximated the optimal foraging value of 2, the more efficient was the retrieval. At an abstract dynamical level, foraging for particular foods in one's niche and searching for particular words in one's memory must be similar processes if particular foods and particular words are randomly and sparsely located in their respective spaces at sites that are not known a priori. We discuss whether Lévy dynamics imply that memory processes, like foraging, are optimized in an ecological way.

Improvement of common carp (Cyprinus carpio) sperm cryopreservation using a programable freezer.

PubMed

Bernáth, Gergely; Żarski, Daniel; Kása, Eszter; Staszny, Ádám; Várkonyi, Levente; Kollár, Tímea; Hegyi, Árpád; Bokor, Zoltán; Urbányi, Béla; Horváth, Ákos

2016-10-01

The applicability of a programmable freezer for the increased-scale cryopreservation of common carp sperm was investigated. The effect of different equilibration times, cryopreservation methods, extenders, dilution ratios, activating solutions on the post-thaw motility of common carp sperm was investigated. The suitable post-thaw storage time-interval as well as fertilizing capacity of cryopreserved sperm was also examined. The motility, curvilinear velocity (VCL) and straightness (STR) values did not decrease significantly during 60min of equilibration neither in equilibrated nor thawed groups. Motility parameters of thawed sperm were similar using a conventional cryopreservation technique using a polystyrene box [motility (33%), VCL (47μm/s) and STR (88%)] and a programmable freezer: [motility (32%), VCL (54μm/s) and STR (89%)]. The highest motility and VCL was measured with a sugar based extender (grayling extender) at a ratio 1:9 (motility: 52%, VCL: 76μm/s) and 1:20 (motility: 49%, VCL: 76μm/s). The activating solution for cyprinids (ASC) could prolong sperm movement up for 2min. A storage time of six hours following thawing did not have a significant effect on the motility parameters of thawed carp sperm. Agglutination was observed during cryopreservation of an elevated volume of sperm whereas motility 47%, VCL 62μm/s and STR 91% were measured after thawing. Fertilization rate with thawed sperm (32%) was significantly lower compared to the control group (73%). According to our results, the developed method using a programmable freezer is suitable for the cryopreservation of elevated number of straws. However, carp sperm agglutination during freezing may have a negative effect on the fertilizing capacity. Copyright © 2016 Elsevier Inc. All rights reserved.

Timing and documentation of key events in neonatal resuscitation.

PubMed

Heathcote, Adam Charles; Jones, Jacqueline; Clarke, Paul

2018-04-30

Only a minority of babies require extended resuscitation at birth. Resuscitations concerning babies who die or who survive with adverse outcomes are increasingly subject to medicolegal scrutiny. Our aim was to describe real-life timings of key resuscitation events observed in a historical series of newborns who required full resuscitation at birth. Twenty-seven babies born in our centre over a 10-year period had an Apgar score of 0 at 1 min and required full resuscitation. The median (95% confidence interval) postnatal age at achieving key events were commencing cardiac compressions, 2.0 (1.5-4.0) min; endotracheal intubation, 3.8 (2.0-6.0) min; umbilical venous catheterisation 9.0 (7.5-12.0) min; and administration of first adrenaline dose 10.0 (8.0-14.0) min. The wide range of timings presented from real-life cases may prove useful to clinicians involved in medical negligence claims and provide a baseline for quality improvements in resuscitation training. What is Known: • Only a minority of babies require extended resuscitation at birth; these cases are often subject to medicolegal interrogation • Timings of key resuscitation events are poorly described and documentation of resuscitation events is often lacking yet is open to medicolegal scrutiny What is New: • We present a wide range of real-life timings of key resuscitation events during the era of routine newborn life support training • These timings may prove useful to clinicians involved in medical negligence claims and provide a baseline for quality improvements in resuscitation training.

Clinical and microbiologic characteristics of adult patients with recurrent bacteraemia caused by extended-spectrum β-lactamase-producing Escherichia coli or Klebsiella pneumoniae.

PubMed

Lee, C-H; Su, L-H; Chen, F-J; Tang, Y-F; Chien, C-C; Liu, J-W

2015-12-01

The characteristics of patients with recurrent bacteraemia caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli or Klebsiella pneumoniae (EK) are rarely described. Flomoxef belongs to the cephamycins group and demonstrates in vitro activity against ESBL-producing organisms. Whether flomoxef may be used for the treatment of such infections remains controversial. This retrospective case-control study enrolled adult patients who had bacteraemia caused by ESBL-EK during 2005-2011. Case patients were those who had more than one episode of ESBL-EK bacteraemia. Controls were those who were matched for age and interval time of blood sampling and had only one episode of ESBL-EK bacteraemia with subsequent bacteraemia episodes caused by other non-ESBL-EK bacteria. Pulsed-field gel electrophoresis and microbiologic profiles of the initial and subsequent ESBL-EK isolates were analysed. During the study period, 424 patients were found to have at least one positive blood culture after the first ESBL-EK bacteraemia episode, and 67 (15.8%) had a second episode of ESBL-EK bacteraemia. Bacteraemia resulting from vascular catheter-related infection (odds ratio, 3.24; 95% confidence interval, 1.31-8.05), and definitive therapy with flomoxef (odds ratio, 2.99; 95% confidence interval, 1.10-8.15) were both independent risk factors for the recurrence. Among the 56 patients with available ESBL-EK isolates for analysis, 38 (67.8%) were infected by genetically similar strains. In three of these 38 recurrent ESBL-EK bacteraemia cases caused by an identical strain, the minimum inhibitory concentrations of carbapenem for the subsequent K. pneumoniae isolates were fourfold or higher than the initial isolates. Recurrent bacteraemia was not uncommon in our patients with ESBL-EK bacteraemia, and most of the episodes were caused by identical strains. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Contraceptive adoption in the extended postpartum period is low in Northwest Ethiopia.

PubMed

Mengesha, Zelalem Birhanu; Worku, Abebaw Gebeyehu; Feleke, Senafikish Amsalu

2015-08-01

The extended postpartum period is a one year period after delivery which is critical for women to prevent unintended pregnancy and to reduce the risk of maternal and child mortality by ensuring safe birth intervals. Studies indicate that birth intervals of three to five years reduce maternal mortality and provide health benefits to newborn babies, infants, and children. As a result, assessing postpartum contraceptive use and its determinants are an increasingly important component of global health. The objectives of the study were to determine postpartum contraceptive use and identify the variables which affect postpartum contraceptive use among women of Dabat district. All women aged 15 to 49 years who delivered a child between January 1, 2012 and December 31, 2012 in the Debat district were interviewed by house-to- house survey. A total of 10.3 % of the mothers reported adopting contraception in the extended postpartum period. Women who delivered with the assistance of a skilled attendant [AOR = 1.88, 95 % CI (1.01-3.51)] and attended postnatal care services [AOR = 2.19, 95 % CI (1.06-4.52)] were more likely to use contraceptives. Secondary and above level of the husband's education was also a variable that significantly affected postpartum contraceptive use [AOR = 2.98, 95 % CI (1.49-5.97)]. Contraceptive use in the extended postpartum period was found to be low placing women at risk for a pregnancy in the extended postpartum period. Advice about contraceptives during postnatal clinic visits was limited. Improving utilization of institutional delivery by a skilled attendant and enhancing postnatal care services are important to increase contraceptive use in the extended postpartum period.

EAGLE Monitors by Collecting Facts and Generating Obligations

NASA Technical Reports Server (NTRS)

Barrnger, Howard; Goldberg, Allen; Havelund, Klaus; Sen, Koushik

2003-01-01

We present a rule-based framework, called EAGLE, that has been shown to be capable of defining and implementing a range of finite trace monitoring logics, including future and past time temporal logic, extended regular expressions, real-time and metric temporal logics, interval logics, forms of quantified temporal logics, and so on. A monitor for an EAGLE formula checks if a finite trace of states satisfies the given formula. We present, in details, an algorithm for the synthesis of monitors for EAGLE. The algorithm is implemented as a Java application and involves novel techniques for rule definition, manipulation and execution. Monitoring is achieved on a state-by-state basis avoiding any need to store the input trace of states. Our initial experiments have been successful as EAGLE detected a previously unknown bug while testing a planetary rover controller.

On implementation of the extended interior penalty function. [optimum structural design

NASA Technical Reports Server (NTRS)

Cassis, J. H.; Schmit, L. A., Jr.

1976-01-01

The extended interior penalty function formulation is implemented. A rational method for determining the transition between the interior and extended parts is set forth. The formulation includes a straightforward method for avoiding design points with some negative components, which are physically meaningless in structural analysis. The technique, when extended to problems involving parametric constraints, can facilitate closed form integration of the penalty terms over the most important parts of the parameter interval. The method lends itself well to the use of approximation concepts, such as design variable linking, constraint deletion and Taylor series expansions of response quantities in terms of design variables. Examples demonstrating the algorithm, in the context of planar orthogonal frames subjected to ground motion, are included.

Evaluation about the Performance of E-Government Based on Interval-Valued Intuitionistic Fuzzy Set

PubMed Central

Zhang, Shuai; Wang, Yan

2014-01-01

The evaluation is an important approach to promote the development of the E-Government. Since the rapid development of E-Government in the world, the E-Government performance evaluation has become a hot issue in the academia. In this paper, we develop a new evaluation method for the development of the E-Government based on the interval-valued intuitionistic fuzzy set which is a powerful technique in expressing the uncertainty of the real situation. First, we extend the geometric Heronian mean (GHM) operator to interval-valued intuitionistic fuzzy environment and proposed the interval-valued intuitionistic fuzzy GHM (IIFGHM) operator. Then, we investigate the relationships between the IIFGHM operator and some existing ones, such as generalized interval-valued intuitionistic fuzzy HM (GIIFHM) and interval-valued intuitionistic fuzzy weighted Bonferoni mean operator. Furthermore, we validate the effectiveness of the proposed method using a real case about the E-Government evaluation in Hangzhou City, China. PMID:24707196

The Perceived Socioeconomic Status Is an Important Factor of Health Recovery for Victims of Occupational Accidents in Korea.

PubMed

Seok, Hongdeok; Yoon, Jin-Ha; Lee, Wanhyung; Lee, June-Hee; Jung, Pil Kyun; Roh, Jaehoon; Won, Jong-Uk

2016-02-01

We aimed to examine whether there is a correlation between the health recovery of industrial accident victims and their perceived socioeconomic status. Data were obtained from the first Panel Study of Worker's Compensation Insurance, which included 2,000 participants. We performed multivariate regression analysis and determined the odds ratios for participants with a subjectively lower socioeconomic status and for those with a subjectively lower middle socioeconomic status using 95% confidence intervals. An additional multivariate regression analysis yielded the odds ratios for participants with a subjectively lower socioeconomic status and those with a subjectively upper middle socioeconomic class using 95% confidence intervals. Of all participants, 299 reported a full recovery, whereas 1,701 did not. We examined the odds ratio (95% confidence intervals) for participants' health recovery according to their subjective socioeconomic status while controlling for sex, age, education, tobacco use, alcohol use, subjective state of health prior to the accident, chronic disease, employment duration, recovery period, accident type, disability status, disability rating, and economic participation. The odds of recovery in participants with a subjectively lower middle socioeconomic status were 1.707 times greater (1.264-2.305) than that of those with a subjectively lower socioeconomic status. Similarly, the odds of recovery in participants with a subjectively upper middle socioeconomic status were 3.124 times greater (1.795-5.438) than that of those with a subjectively lower socioeconomic status. Our findings indicate that participants' perceived socioeconomic disparities extend to disparities in their health status. The reinforcement of welfare measures is greatly needed to temper these disparities.

Occult Pelvic Lymph Node Involvement in Bladder Cancer: Implications for Definitive Radiation

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

Goldsmith, Benjamin; Baumann, Brian C.; He, Jiwei

2014-03-01

Purpose: To inform radiation treatment planning for clinically staged, node-negative bladder cancer patients by identifying clinical factors associated with the presence and location of occult pathologic pelvic lymph nodes. Methods and Materials: The records of patients with clinically staged T1-T4N0 urothelial carcinoma of the bladder undergoing radical cystectomy and pelvic lymphadenectomy at a single institution were reviewed. Logistic regression was used to evaluate associations between preoperative clinical variables and occult pathologic pelvic or common iliac lymph nodes. Percentages of patient with involved lymph node regions entirely encompassed within whole bladder (perivesicular nodal region), small pelvic (perivesicular, obturator, internal iliac, andmore » external iliac nodal regions), and extended pelvic clinical target volume (CTV) (small pelvic CTV plus common iliac regions) were calculated. Results: Among 315 eligible patients, 81 (26%) were found to have involved pelvic lymph nodes at the time of surgery, with 38 (12%) having involved common iliac lymph nodes. Risk of occult pathologically involved lymph nodes did not vary with clinical T stage. On multivariate analysis, the presence of lymphovascular invasion (LVI) on preoperative biopsy was significantly associated with occult pelvic nodal involvement (odds ratio 3.740, 95% confidence interval 1.865-7.499, P<.001) and marginally associated with occult common iliac nodal involvement (odds ratio 2.307, 95% confidence interval 0.978-5.441, P=.056). The percentages of patients with involved lymph node regions entirely encompassed by whole bladder, small pelvic, and extended pelvic CTVs varied with clinical risk factors, ranging from 85.4%, 95.1%, and 100% in non-muscle-invasive patients to 44.7%, 71.1%, and 94.8% in patients with muscle-invasive disease and biopsy LVI. Conclusions: Occult pelvic lymph node rates are substantial for all clinical subgroups, especially patients with LVI on biopsy. Extended coverage of pelvic lymph nodes up to the level of the common iliac nodes may be warranted in subsets of patients.« less

Limnological and climatic environments at Upper Klamath Lake, Oregon during the past 45 000 years

USGS Publications Warehouse

Bradbury, J.P.; Colman, Steven M.; Dean, W.E.

2004-01-01

Upper Klamath Lake, in south-central Oregon, contains long sediment records with well-preserved diatoms and lithological variations that reflect climate-induced limnological changes. These sediment archives complement and extend high resolution terrestrial records along a north-south transect that includes areas influenced by the Aleutian Low and Subtropical High, which control both marine and continental climates in the western United States. The longest and oldest core collected in this study came from the southwest margin of the lake at Caledonia Marsh, and was dated by radiocarbon and tephrochronology to an age of about 45 ka. Paleolimnological interpretations of this core, based upon geochemical and diatom analyses, have been augmented by data from a short core collected from open water environments at nearby Howards Bay and from a 9-m core extending to 15 ka raised from the center of the northwestern part of Upper Klamath Lake. Pre- and full-glacial intervals of the Caledonia Marsh core are characterized and dominated by lithic detrital material. Planktic diatom taxa characteristic of cold-water habitats (Aulacoseira subarctica and A. islandica) alternate with warm-water planktic diatoms (A. ambigua) between 45 and 23 ka, documenting climate changes at millennial scales during oxygen isotope stage (OIS) 3. The full-glacial interval contains mostly cold-water planktic, benthic, and reworked Pliocene lacustrine diatoms (from the surrounding Yonna Formation) that document shallow water conditions in a cold, windy environment. After 15 ka, diatom productivity increased. Organic carbon and biogenic silica became significant sediment components and diatoms that live in the lake today, indicative of warm, eutrophic water, became prominent. Lake levels fell during the mid-Holocene and marsh environments extended over the core site. This interval is characterized by high levels of organic carbon from emergent aquatic vegetation (Scirpus) and by the Mazama ash (7.55 ka), generated by the eruption that created nearby Crater Lake. For a brief time the ash increased the salinity of Upper Klamath Lake. High concentrations of molybdenum, arsenic, and vanadium indicate that Caledonia Marsh was anoxic from about 7 to 5 ka. After the mid-Holocene, shallow, but open-water environments returned to the core site. The sediments became dominated (>80%) by biogenic silica. The open-water cores show analogous but less extreme limnological and climatic changes more typical of mid-lake environments. Millennial-scale lake and climate changes during OIS 3 at Upper Klamath Lake contrast with a similar record of variation at Owens Lake, about 750 km south. When Upper Klamath Lake experienced cold-climate episodes during OIS 3, Owens Lake had warm but wet episodes; the reverse occurred during warmer intervals at Upper Klamath Lake. Such climatic alternations apparently reflect the variable position and strength of the Aleutian Low during the mid-Wisconsin.

Extended Follow-up Confirms Early Vaccine-Enhanced Risk of HIV Acquisition and Demonstrates Waning Effect Over Time Among Participants in a Randomized Trial of Recombinant Adenovirus HIV Vaccine (Step Study)

PubMed Central

Duerr, Ann; Huang, Yunda; Buchbinder, Susan; Coombs, Robert W.; Sanchez, Jorge; del Rio, Carlos; Casapia, Martin; Santiago, Steven; Gilbert, Peter; Corey, Lawrence; Robertson, Michael N.

2012-01-01

Background. The Step Study tested whether an adenovirus serotype 5 (Ad5)–vectored human immunodeficiency virus (HIV) vaccine could prevent HIV acquisition and/or reduce viral load set-point after infection. At the first interim analysis, nonefficacy criteria were met. Vaccinations were halted; participants were unblinded. In post hoc analyses, more HIV infections occurred in vaccinees vs placebo recipients in men who had Ad5-neutralizing antibodies and/or were uncircumcised. Follow-up was extended to assess relative risk of HIV acquisition in vaccinees vs placebo recipients over time. Methods. We used Cox proportional hazard models for analyses of vaccine effect on HIV acquisition and vaccine effect modifiers, and nonparametric and semiparametric methods for analysis of constancy of relative risk over time. Results. One hundred seventy-two of 1836 men were infected. The adjusted vaccinees vs placebo recipients hazard ratio (HR) for all follow-up time was 1.40 (95% confidence interval [CI], 1.03–1.92; P = .03). Vaccine effect differed by baseline Ad5 or circumcision status during first 18 months, but neither was significant for all follow-up time. The HR among uncircumcised and/or Ad5-seropositive men waned with time since vaccination. No significant vaccine-associated risk was seen among circumcised, Ad5-negative men (HR, 0.97; P = 1.0) over all follow-up time. Conclusions. The vaccine-associated risk seen in interim analysis was confirmed but waned with time from vaccination. Clinical Trials Registration. NCT00095576. PMID:22561365

Further investigation of the spontaneous and evoked activity of the primary neurons of statoreceptors (and other receptors) of the labyrinth of the bullfrog before, during and after an extended period of weightlessness, including alternative intervals of artificial gravity

NASA Technical Reports Server (NTRS)

1977-01-01

Vestibular neuron activity was examined by studying nerve stimulation and evoked response. A cooling element, applied to the nerve consisted of a silver hook through which a coolant fluid flowed. Temperature changes were recorded via microtermistors on an eight channel brush recorder, together with response. Diffusion of the cooling effect was measured, recovery time was assessed, and the nerve was then studied hystologically and ultrastructurally. Problems in frog preparation were discussed along with problems in maintaining healthy specimens and bacteria controlled aquaria.

Simultaneous miocene extension and shortening in the himalayan orogen.

PubMed

Hodges, K V; Parrish, R R; Housh, T B; Lux, D R; Burchfiel, B C; Royden, L H; Chen, Z

1992-11-27

The South Tibetan detachment system separates the high-grade metamorphic core of the Himalayan orogen from its weakly metamorphosed suprastructure. It is thought to have developed in response to differences in gravitational potential energy produced by crustal thickening across the mountain front. Geochronologic data from the Rongbuk Valley, north of Qomolangma (Mount Everest) in southern Tibet, demonstrate that at least one segment of the detachment system was active between 19 and 22 million years ago, an interval characterized by large-scale crustal thickening at lower structural levels. These data suggest that decoupling between an extending upper crust and a converging lower crust was an important aspect of Himalayan tectonics in Miocene time.

Estimation of Rainfall Sampling Uncertainty: A Comparison of Two Diverse Approaches

NASA Technical Reports Server (NTRS)

Steiner, Matthias; Zhang, Yu; Baeck, Mary Lynn; Wood, Eric F.; Smith, James A.; Bell, Thomas L.; Lau, William K. M. (Technical Monitor)

2002-01-01

The spatial and temporal intermittence of rainfall causes the averages of satellite observations of rain rate to differ from the "true" average rain rate over any given area and time period, even if the satellite observations are perfectly accurate. The difference of satellite averages based on occasional observation by satellite systems and the continuous-time average of rain rate is referred to as sampling error. In this study, rms sampling error estimates are obtained for average rain rates over boxes 100 km, 200 km, and 500 km on a side, for averaging periods of 1 day, 5 days, and 30 days. The study uses a multi-year, merged radar data product provided by Weather Services International Corp. at a resolution of 2 km in space and 15 min in time, over an area of the central U.S. extending from 35N to 45N in latitude and 100W to 80W in longitude. The intervals between satellite observations are assumed to be equal, and similar In size to what present and future satellite systems are able to provide (from 1 h to 12 h). The sampling error estimates are obtained using a resampling method called "resampling by shifts," and are compared to sampling error estimates proposed by Bell based on earlier work by Laughlin. The resampling estimates are found to scale with areal size and time period as the theory predicts. The dependence on average rain rate and time interval between observations is also similar to what the simple theory suggests.

Enhancing Heart-Beat-Based Security for mHealth Applications.

PubMed

Seepers, Robert M; Strydis, Christos; Sourdis, Ioannis; De Zeeuw, Chris I

2017-01-01

In heart-beat-based security, a security key is derived from the time difference between consecutive heart beats (the inter-pulse interval, IPI), which may, subsequently, be used to enable secure communication. While heart-beat-based security holds promise in mobile health (mHealth) applications, there currently exists no work that provides a detailed characterization of the delivered security in a real system. In this paper, we evaluate the strength of IPI-based security keys in the context of entity authentication. We investigate several aspects that should be considered in practice, including subjects with reduced heart-rate variability (HRV), different sensor-sampling frequencies, intersensor variability (i.e., how accurate each entity may measure heart beats) as well as average and worst-case-authentication time. Contrary to the current state of the art, our evaluation demonstrates that authentication using multiple, less-entropic keys may actually increase the key strength by reducing the effects of intersensor variability. Moreover, we find that the maximal key strength of a 60-bit key varies between 29.2 bits and only 5.7 bits, depending on the subject's HRV. To improve security, we introduce the inter-multi-pulse interval (ImPI), a novel method of extracting entropy from the heart by considering the time difference between nonconsecutive heart beats. Given the same authentication time, using the ImPI for key generation increases key strength by up to 3.4 × (+19.2 bits) for subjects with limited HRV, at the cost of an extended key-generation time of 4.8 × (+45 s).

Antibiotic prophylaxis and risk of Clostridium difficile infection after coronary artery bypass graft surgery.

PubMed

Poeran, Jashvant; Mazumdar, Madhu; Rasul, Rehana; Meyer, Joanne; Sacks, Henry S; Koll, Brian S; Wallach, Frances R; Moskowitz, Alan; Gelijns, Annetine C

2016-02-01

Antibiotic use, particularly type and duration, is a crucial modifiable risk factor for Clostridium difficile. Cardiac surgery is of particular interest because prophylactic antibiotics are recommended for 48 hours or less (vs ≤24 hours for noncardiac surgery), with increasing vancomycin use. We aimed to study associations between antibiotic prophylaxis (duration/vancomycin use) and C difficile among patients undergoing coronary artery bypass grafting. We extracted data on coronary artery bypass grafting procedures from the national Premier Perspective claims database (2006-2013, n = 154,200, 233 hospitals). Multilevel multivariable logistic regressions measured associations between (1) duration (<2 days, "standard" vs ≥2 days, "extended") and (2) type of antibiotic used ("cephalosporin," "cephalosporin + vancomycin," "vancomycin") and C difficile as outcome. Overall C difficile prevalence was 0.21% (n = 329). Most patients (59.7%) received a cephalosporin only; in 33.1% vancomycin was added, whereas 7.2% received vancomycin only. Extended prophylaxis was used in 20.9%. In adjusted analyses, extended prophylaxis (vs standard) was associated with significantly increased C difficile risk (odds ratio, 1.43; confidence interval, 1.07-1.92), whereas no significant associations existed for vancomycin use as adjuvant or primary prophylactic compared with the use of cephalosporins (odds ratio, 1.21; confidence interval, 0.92-1.60, and odds ratio, 1.39; confidence interval, 0.94-2.05, respectively). Substantial inter-hospital variation exists in the percentage of extended antibiotic prophylaxis (interquartile range, 2.5-35.7), use of adjuvant vancomycin (interquartile range, 4.2-61.1), and vancomycin alone (interquartile range, 2.3-10.4). Although extended use of antibiotic prophylaxis was associated with increased C difficile risk after coronary artery bypass grafting, vancomycin use was not. The observed hospital variation in antibiotic prophylaxis practices suggests great potential for efforts aimed at standardizing practices that subsequently could reduce C difficile risk. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Conventional vs. extended-cycle oral contraceptives on the quality of sexual life: comparison between two regimens containing 3 mg drospirenone and 20 µg ethinyl estradiol.

PubMed

Caruso, Salvatore; Iraci Sareri, Marco; Agnello, Carmela; Romano, Mattea; Lo Presti, Lucia; Malandrino, Chiara; Cianci, Antonio

2011-05-01

Women may use new oral contraceptives (OC) having flexible extended-cycle regimens with a reduced hormone-free interval. To study the changes of the quality of sexual life in users of the traditional 21/7 or extended-cycle 24/4 OC regimens both containing 3 mg drospirenone and 20 µg ethinyl estradiol. One hundred fifteen women (age range 18-37 years) were enrolled. Fifty-four women were randomly placed on traditional OC standard regimen, administered for 21 days, followed by a 7-day hormone-free interval (group A); and 61 women were placed on extended-cycle OC regimen covering 24 days of the cycle with a 4-day hormone-free interval (group B). The Short Form-36 (SF-36) validate questionnaire to assess quality of life (QoL) and the Short Personal Experience Questionnaire (SPEQ) to measure the changes of sexual behavior were administered before starting OC intake and at the 3rd and 6th cycle follow-ups. The SF-36 and the SPEQ questionnaires. Group A women reported QoL improvement during the 6th cycle on all the scales (P < 0.05). Group B women reported QoL improvement during the 3rd and 6th cycle (P < 0.05). Satisfaction with sexual activity, arousal, orgasm, and desire increased during the 3rd cycle in women on the group B (P < 0.05). Group A women did not report any change in all SPEQ items. At the 6th cycle, group B women reported better sexual experience than baseline in all SPEQ items (P < 0.05). All subjects who were affected by dyspareunia before OC intake reported decreased genital pain associated with intercourse at the 3rd and 6th cycle of both OC regimens (P < 0.05). Women could use OCs in a subjective flexible modality. The extended-cycle OC might produce positive effects on the quality of sexual life, enforcing the concept of tailoring an OC to a woman. © 2011 International Society for Sexual Medicine.

Comparison of circular orbit and Fourier power series ephemeris representations for backup use by the upper atmosphere research satellite onboard computer

NASA Technical Reports Server (NTRS)

Kast, J. R.

1988-01-01

The Upper Atmosphere Research Satellite (UARS) is a three-axis stabilized Earth-pointing spacecraft in a low-Earth orbit. The UARS onboard computer (OBC) uses a Fourier Power Series (FPS) ephemeris representation that includes 42 position and 42 velocity coefficients per axis, with position residuals at 10-minute intervals. New coefficients and 32 hours of residuals are uploaded daily. This study evaluated two backup methods that permit the OBC to compute an approximate spacecraft ephemeris in the event that new ephemeris data cannot be uplinked for several days: (1) extending the use of the FPS coefficients previously uplinked, and (2) switching to a simple circular orbit approximation designed and tested (but not implemented) for LANDSAT-D. The FPS method provides greater accuracy during the backup period and does not require additional ground operational procedures for generating and uplinking an additional ephemeris table. The tradeoff is that the high accuracy of the FPS will be degraded slightly by adopting the longer fit period necessary to obtain backup accuracy for an extended period of time. The results for UARS show that extended use of the FPS is superior to the circular orbit approximation for short-term ephemeris backup.

Interval oscillation criteria for second-order forced impulsive delay differential equations with damping term.

PubMed

Thandapani, Ethiraju; Kannan, Manju; Pinelas, Sandra

2016-01-01

In this paper, we present some sufficient conditions for the oscillation of all solutions of a second order forced impulsive delay differential equation with damping term. Three factors-impulse, delay and damping that affect the interval qualitative properties of solutions of equations are taken into account together. The results obtained in this paper extend and generalize some of the the known results for forced impulsive differential equations. An example is provided to illustrate the main result.

Timing of paleoearthquakes on the northern Hayward Fault: preliminary evidence in El Cerrito, California

USGS Publications Warehouse

Lienkaemper, J.J.; Schwartz, D.P.; Kelson, K.I.; Lettis, W.R.; Simpson, Gary D.; Southon, J.R.; Wanket, J.A.; Williams, P.L.

1999-01-01

The Working Group on California Earthquake Probabilities estimated that the northern Hayward fault had the highest probability (0.28) of producing a M7 Bay Area earthquake in 30 years (WGCEP, 1990). This probability was based, in part, on the assumption that the last large earthquake occurred on this segment in 1836. However, a recent study of historical documents concludes that the 1836 earthquake did not occur on the northern Hayward fault, thereby extending the elapsed time to at least 220 yr ago, the beginning of the written record. The average recurrence interval for a M7 on the northern Hayward is unknown. WGCEP (1990) assumed an interval of 167 years. The 1996 Working Group on Northern California Earthquake Potential estimated ~210 yr, based on extrapolations from southern Hayward paleoseismological studies and a revised estimate of 1868 slip on the southern Hayward fault. To help constrain the timing of paleoearthquakes on the northern Hayward fault for the 1999 Bay Area probability update, we excavated two trenches that cross the fault and a sag pond on the Mira Vista golf course. As the site is on the second fairway, we were limited to less than ten days to document these trenches. Analysis was aided by rapid C-14 dating of more than 90 samples which gave near real-time results with the trenches still open. A combination of upward fault terminations, disrupted strata, and discordant angular relations indicates at least four, and possibly seven or more, surface faulting earthquakes occurred during a 1630-2130 yr interval. Hence, average recurrence time could be <270 yr, but is no more than 710 yr. The most recent earthquake (MRE) occurred after AD 1640. Preliminary analysis of calibrated dates supports the assumption that no large historical (post-1776) earthquakes have ruptured the surface here, but the youngest dates need more corroboration. Analyses of pollen for presence of non-native species help to constrain the time of the MRE. The earthquake recurrence estimates described in this report are preliminary and should not be used as a basis for hazard estimates. Additional trenching is planned for this location to answer questions raised during the initial phase of trenching.

A Trial of Extending Hemodialysis Hours and Quality of Life.

PubMed

Jardine, Meg J; Zuo, Li; Gray, Nicholas A; de Zoysa, Janak R; Chan, Christopher T; Gallagher, Martin P; Monaghan, Helen; Grieve, Stuart M; Puranik, Rajesh; Lin, Hongli; Eris, Josette M; Zhang, Ling; Xu, Jinsheng; Howard, Kirsten; Lo, Serigne; Cass, Alan; Perkovic, Vlado

2017-06-01

The relationship between increased hemodialysis hours and patient outcomes remains unclear. We randomized (1:1) 200 adult recipients of standard maintenance hemodialysis from in-center and home-based hemodialysis programs to extended weekly (≥24 hours) or standard (target 12-15 hours, maximum 18 hours) hemodialysis hours for 12 months. The primary outcome was change in quality of life from baseline assessed by the EuroQol 5 dimension instrument (3 level) (EQ-5D). Secondary outcomes included medication usage, clinical laboratory values, vascular access events, and change in left ventricular mass index. At 12 months, median weekly hemodialysis hours were 24.0 (interquartile range, 23.6-24.0) and 12.0 (interquartile range, 12.0-16.0) in the extended and standard groups, respectively. Change in EQ-5D score at study end did not differ between groups (mean difference, 0.04 [95% confidence interval, -0.03 to 0.11]; P =0.29). Extended hours were associated with lower phosphate and potassium levels and higher hemoglobin levels. Blood pressure (BP) did not differ between groups at study end. Extended hours were associated with fewer BP-lowering agents and phosphate-binding medications, but were not associated with erythropoietin dosing. In a substudy with 95 patients, we detected no difference between groups in left ventricular mass index (mean difference, -6.0 [95% confidence interval, -14.8 to 2.7] g/m 2 ; P =0.18). Five deaths occurred in the extended group and two in the standard group ( P =0.44); two participants in each group withdrew consent. Similar numbers of patients experienced vascular access events in the two groups. Thus, extending weekly hemodialysis hours did not alter overall EQ-5D quality of life score, but was associated with improvement in some laboratory parameters and reductions in medication burden. (Clinicaltrials.gov identifier: NCT00649298). Copyright © 2017 by the American Society of Nephrology.

Timescale- and Sensory Modality-Dependency of the Central Tendency of Time Perception.

PubMed

Murai, Yuki; Yotsumoto, Yuko

2016-01-01

When individuals are asked to reproduce intervals of stimuli that are intermixedly presented at various times, longer intervals are often underestimated and shorter intervals overestimated. This phenomenon may be attributed to the central tendency of time perception, and suggests that our brain optimally encodes a stimulus interval based on current stimulus input and prior knowledge of the distribution of stimulus intervals. Two distinct systems are thought to be recruited in the perception of sub- and supra-second intervals. Sub-second timing is subject to local sensory processing, whereas supra-second timing depends on more centralized mechanisms. To clarify the factors that influence time perception, the present study investigated how both sensory modality and timescale affect the central tendency. In Experiment 1, participants were asked to reproduce sub- or supra-second intervals, defined by visual or auditory stimuli. In the sub-second range, the magnitude of the central tendency was significantly larger for visual intervals compared to auditory intervals, while visual and auditory intervals exhibited a correlated and comparable central tendency in the supra-second range. In Experiment 2, the ability to discriminate sub-second intervals in the reproduction task was controlled across modalities by using an interval discrimination task. Even when the ability to discriminate intervals was controlled, visual intervals exhibited a larger central tendency than auditory intervals in the sub-second range. In addition, the magnitude of the central tendency for visual and auditory sub-second intervals was significantly correlated. These results suggest that a common modality-independent mechanism is responsible for the supra-second central tendency, and that both the modality-dependent and modality-independent components of the timing system contribute to the central tendency in the sub-second range.

Specific agreement on dichotomous outcomes can be calculated for more than two raters.

PubMed

de Vet, Henrica C W; Dikmans, Rieky E; Eekhout, Iris

2017-03-01

For assessing interrater agreement, the concepts of observed agreement and specific agreement have been proposed. The situation of two raters and dichotomous outcomes has been described, whereas often, multiple raters are involved. We aim to extend it for more than two raters and examine how to calculate agreement estimates and 95% confidence intervals (CIs). As an illustration, we used a reliability study that includes the scores of four plastic surgeons classifying photographs of breasts of 50 women after breast reconstruction into "satisfied" or "not satisfied." In a simulation study, we checked the hypothesized sample size for calculation of 95% CIs. For m raters, all pairwise tables [ie, m (m - 1)/2] were summed. Then, the discordant cells were averaged before observed and specific agreements were calculated. The total number (N) in the summed table is m (m - 1)/2 times larger than the number of subjects (n), in the example, N = 300 compared to n = 50 subjects times m = 4 raters. A correction of n√(m - 1) was appropriate to find 95% CIs comparable to bootstrapped CIs. The concept of observed agreement and specific agreement can be extended to more than two raters with a valid estimation of the 95% CIs. Copyright © 2017 Elsevier Inc. All rights reserved.

High resolution data acquisition

DOEpatents

Thornton, G.W.; Fuller, K.R.

1993-04-06

A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock, pulse train, and analog circuitry for generating a triangular wave synchronously with the pulse train (as seen in diagram on patent). The triangular wave has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter counts the clock pulse train during the interval to form a gross event interval time. A computer then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

High resolution data acquisition

DOEpatents

Thornton, Glenn W.; Fuller, Kenneth R.

1993-01-01

A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock (38) pulse train (37) and analog circuitry (44) for generating a triangular wave (46) synchronously with the pulse train (37). The triangular wave (46) has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter (18, 32) forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter (26) counts the clock pulse train (37) during the interval to form a gross event interval time. A computer (52) then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

Urinary excretion of ciprofloxacin after administration of extended release tablets in healthy volunteers. Swellable drug-polyelectrolyte matrix versus bilayer tablets.

PubMed

Guzmán, M L; Romañuk, C B; Sanchez, M F; Luciani Giacobbe, L C; Alarcón-Ramirez, L P; Battistini, F D; Alovero, F L; Jimenez-Kairuz, A F; Manzo, R H; Olivera, María Eugenia

2018-02-01

This paper builds on a previous paper in which new ciprofloxacin extended-release tablets were developed based on a ciprofloxacin-based swellable drug polyelectrolyte matrix (SDPM-CIP). The matrix contains a molecular dispersion of ciprofloxacin ionically bonded to the acidic groups of carbomer, forming the polyelectrolyte-drug complex CB-CIP. This formulation showed that the release profile of the ciprofloxacin bilayer tablets currently commercialised can be achieved with a simpler strategy. Thus, since ciprofloxacin urine concentrations are associated with the clinical cure of urinary tract infections, the goal of this work was to compare the urinary excretion of SDPM-CIP tablets with those of the CIPRO XR® bilayer tablets. A batch of SDPM-CIP tablets was manufactured by the wet granulation method and the CB-CIP ionic complex was obtained in situ. Fasted healthy volunteers received a single oral dose of 500 mg ciprofloxacin of either formulation in a randomised crossover study. Urinary concentrations were assessed by HPLC at intervals up to 36 h. Pharmacokinetic parameters (rate of urinary excretion, maximum urine excretion rate, t max , area under the curve, amount and percentage of the ciprofloxacin dose excreted in urine) showed no statistical differences between both formulations at any of the time intervals of collection. The processing conditions to obtain SDPM-CIP tablets are easy to scale up since they involve technology currently employed in the pharmaceutical industry and the process is less challenging to implement. In addition, SDPM-CIP tablets met pharmacopoeial quality specifications.

Luminosity function of faint galaxies with ultraviolet continuum

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

Stepanyan, D.A.

1985-05-01

The spatial density of faint galaxies with ultraviolet continuum in the Second Survey of the Byurakan Astrophysical Observatory is determined. The luminosity function of galaxies with ultraviolet continuum can be extended to objects fainter by 1-1.5 magnitudes. The spatial density of such galaxies in the interval of luminosities -16 /sup m/ .5 to -21 /sup m/ .5 is on the average 0.08 of the total density of field galaxies in the same interval of absolute magnitudes. The spatial density of low-luminosity galaxies with ultraviolet continuum is very high. In the interval from -12 /sup m/ .5 to -15 /sup m/more » .5 it is 0.23 Mpc/sup -3/.« less

Frequency domain analysis of errors in cross-correlations of ambient seismic noise

NASA Astrophysics Data System (ADS)

Liu, Xin; Ben-Zion, Yehuda; Zigone, Dimitri

2016-12-01

We analyse random errors (variances) in cross-correlations of ambient seismic noise in the frequency domain, which differ from previous time domain methods. Extending previous theoretical results on ensemble averaged cross-spectrum, we estimate confidence interval of stacked cross-spectrum of finite amount of data at each frequency using non-overlapping windows with fixed length. The extended theory also connects amplitude and phase variances with the variance of each complex spectrum value. Analysis of synthetic stationary ambient noise is used to estimate the confidence interval of stacked cross-spectrum obtained with different length of noise data corresponding to different number of evenly spaced windows of the same duration. This method allows estimating Signal/Noise Ratio (SNR) of noise cross-correlation in the frequency domain, without specifying filter bandwidth or signal/noise windows that are needed for time domain SNR estimations. Based on synthetic ambient noise data, we also compare the probability distributions, causal part amplitude and SNR of stacked cross-spectrum function using one-bit normalization or pre-whitening with those obtained without these pre-processing steps. Natural continuous noise records contain both ambient noise and small earthquakes that are inseparable from the noise with the existing pre-processing steps. Using probability distributions of random cross-spectrum values based on the theoretical results provides an effective way to exclude such small earthquakes, and additional data segments (outliers) contaminated by signals of different statistics (e.g. rain, cultural noise), from continuous noise waveforms. This technique is applied to constrain values and uncertainties of amplitude and phase velocity of stacked noise cross-spectrum at different frequencies, using data from southern California at both regional scale (˜35 km) and dense linear array (˜20 m) across the plate-boundary faults. A block bootstrap resampling method is used to account for temporal correlation of noise cross-spectrum at low frequencies (0.05-0.2 Hz) near the ocean microseismic peaks.

Measuring the EMS patient access time interval and the impact of responding to high-rise buildings.

PubMed

Morrison, Laurie J; Angelini, Mark P; Vermeulen, Marian J; Schwartz, Brian

2005-01-01

To measure the patient access time interval and characterize its contribution to the total emergency medical services (EMS) response time interval; to compare the patient access time intervals for patients located three or more floors above ground with those less than three floors above or below ground, and specifically in the apartment subgroup; and to identify barriers that significantly impede EMS access to patients in high-rise apartments. An observational study of all patients treated by an emergency medical technician paramedics (EMT-P) crew was conducted using a trained independent observer to collect time intervals and identify potential barriers to access. Of 118 observed calls, 25 (21%) originated from patients three or more floors above ground. The overall median and 90th percentile (95% confidence interval) patient access time intervals were 1.61 (1.27, 1.91) and 3.47 (3.08, 4.05) minutes, respectively. The median interval was 2.73 (2.22, 3.03) minutes among calls from patients located three or more stories above ground compared with 1.25 (1.07, 1.55) minutes among those at lower levels. The patient access time interval represented 23.5% of the total EMS response time interval among calls originating less than three floors above or below ground and 32.2% of those located three or more stories above ground. The most frequently encountered barriers to access included security code entry requirements, lack of directional signs, and inability to fit the stretcher into the elevator. The patient access time interval is significantly long and represents a substantial component of the total EMS response time interval, especially among ambulance calls originating three or more floors above ground. A number of barriers appear to contribute to delayed paramedic access.

Modulation of human time processing by subthalamic deep brain stimulation.

PubMed

Wojtecki, Lars; Elben, Saskia; Timmermann, Lars; Reck, Christiane; Maarouf, Mohammad; Jörgens, Silke; Ploner, Markus; Südmeyer, Martin; Groiss, Stefan Jun; Sturm, Volker; Niedeggen, Michael; Schnitzler, Alfons

2011-01-01

Timing in the range of seconds referred to as interval timing is crucial for cognitive operations and conscious time processing. According to recent models of interval timing basal ganglia (BG) oscillatory loops are involved in time interval recognition. Parkinsońs disease (PD) is a typical disease of the basal ganglia that shows distortions in interval timing. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment of PD which modulates motor and cognitive functions depending on stimulation frequency by affecting subcortical-cortical oscillatory loops. Thus, for the understanding of BG-involvement in interval timing it is of interest whether STN-DBS can modulate timing in a frequency dependent manner by interference with oscillatory time recognition processes. We examined production and reproduction of 5 and 15 second intervals and millisecond timing in a double blind, randomised, within-subject repeated-measures design of 12 PD-patients applying no, 10-Hz- and ≥ 130-Hz-STN-DBS compared to healthy controls. We found under(re-)production of the 15-second interval and a significant enhancement of this under(re-)production by 10-Hz-stimulation compared to no stimulation, ≥ 130-Hz-STN-DBS and controls. Milliseconds timing was not affected. We provide first evidence for a frequency-specific modulatory effect of STN-DBS on interval timing. Our results corroborate the involvement of BG in general and of the STN in particular in the cognitive representation of time intervals in the range of multiple seconds.

Modulation of Human Time Processing by Subthalamic Deep Brain Stimulation

PubMed Central

Timmermann, Lars; Reck, Christiane; Maarouf, Mohammad; Jörgens, Silke; Ploner, Markus; Südmeyer, Martin; Groiss, Stefan Jun; Sturm, Volker; Niedeggen, Michael; Schnitzler, Alfons

2011-01-01

Timing in the range of seconds referred to as interval timing is crucial for cognitive operations and conscious time processing. According to recent models of interval timing basal ganglia (BG) oscillatory loops are involved in time interval recognition. Parkinsońs disease (PD) is a typical disease of the basal ganglia that shows distortions in interval timing. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment of PD which modulates motor and cognitive functions depending on stimulation frequency by affecting subcortical-cortical oscillatory loops. Thus, for the understanding of BG-involvement in interval timing it is of interest whether STN-DBS can modulate timing in a frequency dependent manner by interference with oscillatory time recognition processes. We examined production and reproduction of 5 and 15 second intervals and millisecond timing in a double blind, randomised, within-subject repeated-measures design of 12 PD-patients applying no, 10-Hz- and ≥130-Hz-STN-DBS compared to healthy controls. We found under(re-)production of the 15-second interval and a significant enhancement of this under(re-)production by 10-Hz-stimulation compared to no stimulation, ≥130-Hz-STN-DBS and controls. Milliseconds timing was not affected. We provide first evidence for a frequency-specific modulatory effect of STN-DBS on interval timing. Our results corroborate the involvement of BG in general and of the STN in particular in the cognitive representation of time intervals in the range of multiple seconds. PMID:21931767

Extending Depot Length and Intervals for DDG 51 Class Ships: Examining the 72 Month Operational Cycle

DTIC Science & Technology

2016-01-01

tenance period to achieve planned expected service life ( ESL ), as well as the length, workload, and periodicity of a continuous maintenance...a ship’s service life but extends the length of each deployment. Figure 2.1 compares the number of deployments that can be made over the ESL of...ships in different cycle lengths. The ESL of DDG-51 Arleigh Burke–class destroyers Flight I and II is 35 years, and Flight IIA has an ESL of 40 years

The Hayward-Rodgers Creek Fault System: Learning from the Past to Forecast the Future

NASA Astrophysics Data System (ADS)

Schwartz, D. P.; Lienkaemper, J. J.; Hecker, S.

2007-12-01

The San Francisco Bay area is located within the Pacific-North American plate boundary. As a result, the region has the highest density of active faults per square kilometer of any urban center in the US. Between the Farallon Islands and Livermore, the faults of the San Andreas fault system are slipping at a rate of about 40 mm/yr. Approximately 25 percent of this rate is accommodated by the Hayward fault and its continuation to the north, the Rodgers Creek fault. The Hayward fault extends 88 km from Warm Springs on the south into San Pablo Bay on the north, traversing the most heavily urbanized part of the Bay Area. The Rodgers Creek fault extends another 63 km, passing through Santa Rosa and ending south of Healdsburg. Geologic, seismologic, and geodetic studies during the past ten years have significantly increased our knowledge of this system. In particular, paleoseismic studies of the timing of past earthquakes have provided critical new information for improving our understanding of how these faults may work in time and space, and for estimating the probability of future earthquakes. The most spectacular result is an 11-earthquake record on the southern Hayward fault that extends back to A.D. 170. It suggests an average time interval between large earthquakes of 170 years for this period, with a shorter interval of 140 years for the five most recent earthquakes. Paleoseismic investigations have also shown that prior to the most recent large earthquake on the southern Hayward fault in 1868, large earthquakes occurred on the southern Hayward fault between 1658 and1786, on the northern Hayward fault between 1640 and 1776, and on the Rodgers Creek fault between 1690 and 1776. These could have been three separate earthquakes. However, the overlapping radiocarbon dates for these paleoearthquakes allow the possibility that these faults may have ruptured together in several different combinations: a combined southern and northern Hayward fault earthquake, a Rodgers Creek-northern Hayward fault earthquake, or a rupture of all three fault sections. Each of these rupture combinations would produce a magnitude larger than 1868 (M~6.9). In 2003, the Working Group on California Earthquake Probabilities released a new earthquake forecast for the Bay Area. Using the earthquake timing data and alternative fault rupture models, the Working Group estimated a 27 percent likelihood of a M?6.7 earthquake along the Hayward-Rodgers Creek fault zone by the year 2031. This is this highest probability of any individual fault system in the Bay Area. New paleoseismic data will allow updating of this forecast.

Caloric primary rewards systematically alter time perception.

PubMed

Fung, Bowen J; Murawski, Carsten; Bode, Stefan

2017-11-01

Human time perception can be influenced by contextual factors, such as the presence of reward. Yet, the exact nature of the relationship between time perception and reward has not been conclusively characterized. We implemented a novel experimental paradigm to measure estimations of time across a range of suprasecond intervals, during the anticipation and after the consumption of fruit juice, a physiologically relevant primary reward. We show that average time estimations were systematically affected by the consumption of reward, but not by the anticipation of reward. Compared with baseline estimations of time, reward consumption was associated with subsequent overproductions of time, and this effect increased for larger magnitudes of reward. Additional experiments demonstrated that the effect of consumption did not extend to a secondary reward (money), a tasteless, noncaloric primary reward (water), or a sweet, noncaloric reward (aspartame). However, a tasteless caloric reward (maltodexrin) did induce overproductions of time, although this effect did not scale with reward magnitude. These results suggest that the consumption of caloric primary rewards can alter time perception, which may be a psychophysiological mechanism by which organisms regulate homeostatic balance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

THE FUNDAMENTAL SOLUTIONS FOR MULTI-TERM MODIFIED POWER LAW WAVE EQUATIONS IN A FINITE DOMAIN.

PubMed

Jiang, H; Liu, F; Meerschaert, M M; McGough, R J

2013-01-01

Fractional partial differential equations with more than one fractional derivative term in time, such as the Szabo wave equation, or the power law wave equation, describe important physical phenomena. However, studies of these multi-term time-space or time fractional wave equations are still under development. In this paper, multi-term modified power law wave equations in a finite domain are considered. The multi-term time fractional derivatives are defined in the Caputo sense, whose orders belong to the intervals (1, 2], [2, 3), [2, 4) or (0, n ) ( n > 2), respectively. Analytical solutions of the multi-term modified power law wave equations are derived. These new techniques are based on Luchko's Theorem, a spectral representation of the Laplacian operator, a method of separating variables and fractional derivative techniques. Then these general methods are applied to the special cases of the Szabo wave equation and the power law wave equation. These methods and techniques can also be extended to other kinds of the multi-term time-space fractional models including fractional Laplacian.

Wetting and drying of soil in response to precipitation: Data analysis, modeling, and forecasting

USGS Publications Warehouse

Basak, Aniruddha; Kulkarni, Chinmay; Schmidt, Kevin M.; Mengshoel, Ole

2016-01-01

This paper investigates methods to analyze and forecast soil moisture time series. We extend an existing Antecedent Water Index (AWI) model, which expresses soil moisture as a function of time and rainfall. Unfortunately, the existing AWI model does not forecast effectively for time periods beyond a few hours. To overcome this limitation, we develop a novel AWI-based model. Our model accumulates rainfall over a time interval and can fit a diverse range of wetting and drying curves. In addition, parameters in our model reflect hydrologic redistribution processes of gravity and suction.We validate our models using experimental soil moisture and rainfall time series data collected from steep gradient post-wildfire sites in Southern California, where rapid landscape change was observed in response to small to moderate rain storms. We found that our novel model fits the data for three distinct soil textures, occurring at different depths below the ground surface (5, 15, and 30 cm). Our model also successfully forecasts soil moisture trends, such as drying and wetting rate.

Late Paleogene-early Neogene dinoflagellate cyst biostratigraphy of the eastern Equatorial Atlantic

NASA Astrophysics Data System (ADS)

Awad, Walaa K.; Oboh-Ikuenobe, Francisca E.

2018-04-01

Six dinoflagellate cyst biozones (zone 1-zone 5, subzones 1a and 1b) are recognized in the late Paleogene-early Neogene interval of the Ocean Drilling Program (ODP) Site 959 (Hole 959 A), Côte d'Ivoire-Ghana Transform Margin in the eastern Equatorial Atlantic. The biozones are based on palynological analysis of 30 samples covering a 273.2-m interval with generally fair preservation and good to poor recovery. We propose a new age of Late Eocene (Priabonian) for subunit IIB as opposed to the previously published mid-Early Oligocene age (middle Rupelian). This age assignment is mainly based on the presence of Late Eocene marker taxa, such as Hemiplacophora semilunifera and Schematophora speciosa in the lower part of the studied interval. We also document for the first time a hiatus event within dinoflagellate cyst zone 3, based on the last occurrences of several taxa. This interval is assigned to an Early Miocene age and is barren of other microfossils. Furthermore, we propose new last occurrences for two species. The last occurrence of Cerebrocysta bartonensis is observed in the late Aquitanian-early Burdigalian in this study vs. Priabonian-early Rupelian in mid and high latitude regions. Also, the last occurrence of Chiropteridium galea extends to the latest Early Miocene (Burdigalian) in ODP Hole 959 A; this event was previously identified in other studies as Chattian in equatorial regions, and Aquitanian in the Northern Hemisphere mid-latitudes. We suspect that these differences are due to physical (offshore vs. nearshore) and latitudinal locations of the areas studied.

"Extended" antipsychotic dosing in the maintenance treatment of schizophrenia: a double-blind, placebo-controlled trial.

PubMed

Remington, Gary; Seeman, Philip; Feingold, Alan; Mann, Steve; Shammi, Chekkera; Kapur, Shitij

2011-08-01

In the treatment of schizophrenia, all currently available oral antipsychotics are administered at least once daily, with strict adherence strongly encouraged to minimize risk of relapse. Based on a better understanding of the brain kinetics of antipsychotics, we have proposed a variation of this approach, "extended" dosing, which allows for intermittent but regular dosing. We carried out a randomized, double-blind, placebo-controlled trial evaluating 35 individuals with DSM-IV-defined schizophrenia who had been stabilized on antipsychotic therapy. Over a 6-month interval, 18 subjects received their medication as usual (daily), while 17 received their antipsychotic therapy every second day (extended). Outcome measures included clinical scales to assess symptoms (Brief Psychiatric Rating Scale [the primary outcome measure], Calgary Depression Scale), illness severity (Clinical Global Impressions-Severity of Illness scale), and relapse (ie, rehospitalization) rates. Side effects were also assessed, including movement disorders (Barnes Akathisia Scale, Simpson-Angus Scale, Abnormal Involuntary Movement Scale) and weight. The study was conducted from February 2003 to July 2007. Individuals in the extended dosing group were not at greater risk of symptom exacerbation, relapse, or rehospitalization; indeed, more rehospitalizations occurred in those receiving regular dosing. At the same time, though, there was no indication that side effects were significantly reduced in the extended dosing group. These results challenge the long-standing dogma that oral antipsychotics must be administered daily in stabilized patients with schizophrenia. Further studies with larger samples are needed to replicate these findings, as well as to elucidate whether postulated clinical advantages can be established and determined to outweigh potential risks. clinicaltrials.gov Identifier: NCT00431574. © Copyright 2011 Physicians Postgraduate Press, Inc.

Parallel network simulations with NEURON.

PubMed

Migliore, M; Cannia, C; Lytton, W W; Markram, Henry; Hines, M L

2006-10-01

The NEURON simulation environment has been extended to support parallel network simulations. Each processor integrates the equations for its subnet over an interval equal to the minimum (interprocessor) presynaptic spike generation to postsynaptic spike delivery connection delay. The performance of three published network models with very different spike patterns exhibits superlinear speedup on Beowulf clusters and demonstrates that spike communication overhead is often less than the benefit of an increased fraction of the entire problem fitting into high speed cache. On the EPFL IBM Blue Gene, almost linear speedup was obtained up to 100 processors. Increasing one model from 500 to 40,000 realistic cells exhibited almost linear speedup on 2,000 processors, with an integration time of 9.8 seconds and communication time of 1.3 seconds. The potential for speed-ups of several orders of magnitude makes practical the running of large network simulations that could otherwise not be explored.

Atmospheric Delta14C Record from Wellington (1954-1993)

DOE Data Explorer

Manning, M R. [National Institute of Water and Atmospheric Research, Ltd., Lower Hutt, New Zealand; Melhuish, W. H. [National Institute of Water and Atmospheric Research, Ltd., Lower Hutt, New Zealand

1994-09-01

Trays containing ~2 L of 5 normal NaOH carbonate-free solution are typically exposed for intervals of 1-2 weeks, and the atmospheric CO₂ absorbed during that time is recovered by acid evolution. Considerable fractionation occurs during absorption into the NaOH solution, and the standard fractionation correction (Stuiver and Polach 1977) is used to determine a δ 14C value corrected to δ 13C = -25 per mil. Some samples reported here were taken using BaOH solution or with extended tray exposure times. These variations in procedure do not appear to affect the results (Manning et al. 1990). A few early measurements were made by bubbling air through columns of NaOH for several hours. These samples have higher δ 13C values. Greater details on the sampling methods are provided in Manning et al. (1990) and Rafter and Fergusson (1959).

Civil helicopter propulsion system reliability and engine monitoring technology assessments

NASA Technical Reports Server (NTRS)

Murphy, J. A.; Zuk, J.

1982-01-01

A study to reduce operating costs of helicopters, particularly directed at the maintenance of the propulsion subsystem, is presented. The tasks of the study consisted of problem definition refinement, technology solutions, diagnostic system concepts, and emergency power augmentation. Quantifiable benefits (reduced fuel consumption, on-condition engine maintenance, extended drive system overhaul periods, and longer oil change intervals) would increase the initial cost by $43,000, but the benefit of $24.46 per hour would result in breakeven at 1758 hours. Other benefits not capable of being quantified but perhaps more important include improved aircraft avilability due to reduced maintenance time, potential for increased operating limits due to continuous automatic monitoring of gages, and less time and fuel required to make engine power checks. The most important improvement is the on-condition maintenance program, which will require the development of algorithms, equipment, and procedures compatible with all operating environments.

Oil-in-oil-emulsions with enhanced substantivity for the treatment of chronic skin diseases.

PubMed

Lunter, Dominique Jasmin; Rottke, Michael; Daniels, Rolf

2014-05-01

The therapy of chronic skin diseases often requires several applications of creams or ointments per day. This is inconvenient to the patients and frequently leads to poor acceptance and compliance. We therefore developed oil-in-oil-emulsions that deliver the active pharmaceutical ingredient (API) to the skin over a prolonged period of time. In this study, we compare the permeation of the API from a conventional formulation to its permeation from an oil-in-oil-emulsion under infinite and finite dosing. Furthermore, we evaluate the substantivity of the formulations. Our results show that the permeation from oil-in-oil-emulsions is constant over a prolonged time and that the emulsions show significantly higher substantivity than conventional formulations. Because of that, the treatment intervals can be extended substantially and compliance can be increased. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Parallel Network Simulations with NEURON

PubMed Central

Migliore, M.; Cannia, C.; Lytton, W.W; Markram, Henry; Hines, M. L.

2009-01-01

The NEURON simulation environment has been extended to support parallel network simulations. Each processor integrates the equations for its subnet over an interval equal to the minimum (interprocessor) presynaptic spike generation to postsynaptic spike delivery connection delay. The performance of three published network models with very different spike patterns exhibits superlinear speedup on Beowulf clusters and demonstrates that spike communication overhead is often less than the benefit of an increased fraction of the entire problem fitting into high speed cache. On the EPFL IBM Blue Gene, almost linear speedup was obtained up to 100 processors. Increasing one model from 500 to 40,000 realistic cells exhibited almost linear speedup on 2000 processors, with an integration time of 9.8 seconds and communication time of 1.3 seconds. The potential for speed-ups of several orders of magnitude makes practical the running of large network simulations that could otherwise not be explored. PMID:16732488

Distributed communication and psychosocial performance in simulated space dwelling groups

NASA Astrophysics Data System (ADS)

Hienz, R. D.; Brady, J. V.; Hursh, S. R.; Ragusa, L. C.; Rouse, C. O.; Gasior, E. D.

2005-05-01

The present report describes the development and application of a distributed interactive multi-person simulation in a computer-generated planetary environment as an experimental test bed for modeling the human performance effects of variations in the types of communication modes available, and in the types of stress and incentive conditions underlying the completion of mission goals. The results demonstrated a high degree of interchangeability between communication modes (audio, text) when one mode was not available. Additionally, the addition of time pressure stress to complete tasks resulted in a reduction in performance effectiveness, and these performance reductions were ameliorated via the introduction of positive incentives contingent upon improved performances. The results obtained confirmed that cooperative and productive psychosocial interactions can be maintained between individually isolated and dispersed members of simulated spaceflight crews communicating and problem-solving effectively over extended time intervals without the benefit of one another's physical presence.

Miniature Bioreactor System for Long-Term Cell Culture

NASA Technical Reports Server (NTRS)

Gonda, Steve R.; Kleis, Stanley J.; Geffert, Sandara K.

2010-01-01

A prototype miniature bioreactor system is designed to serve as a laboratory benchtop cell-culturing system that minimizes the need for relatively expensive equipment and reagents and can be operated under computer control, thereby reducing the time and effort required of human investigators and reducing uncertainty in results. The system includes a bioreactor, a fluid-handling subsystem, a chamber wherein the bioreactor is maintained in a controlled atmosphere at a controlled temperature, and associated control subsystems. The system can be used to culture both anchorage-dependent and suspension cells, which can be either prokaryotic or eukaryotic. Cells can be cultured for extended periods of time in this system, and samples of cells can be extracted and analyzed at specified intervals. By integrating this system with one or more microanalytical instrument(s), one can construct a complete automated analytical system that can be tailored to perform one or more of a large variety of assays.

Research on regional numerical weather prediction

NASA Technical Reports Server (NTRS)

Kreitzberg, C. W.

1976-01-01

Extension of the predictive power of dynamic weather forecasting to scales below the conventional synoptic or cyclonic scales in the near future is assessed. Lower costs per computation, more powerful computers, and a 100 km mesh over the North American area (with coarser mesh extending beyond it) are noted at present. Doubling the resolution even locally (to 50 km mesh) would entail a 16-fold increase in costs (including vertical resolution and halving the time interval), and constraints on domain size and length of forecast. Boundary conditions would be provided by the surrounding 100 km mesh, and time-varying lateral boundary conditions can be considered to handle moving phenomena. More physical processes to treat, more efficient numerical techniques, and faster computers (improved software and hardware) backing up satellite and radar data could produce further improvements in forecasting in the 1980s. Boundary layer modeling, initialization techniques, and quantitative precipitation forecasting are singled out among key tasks.

Physical and sensory quality of hommos preserved with combined gamma radiation and refrigeration

NASA Astrophysics Data System (ADS)

Amr, A.; Al-Qadiri, H.; Saleh, M.; Shahein, M.

2018-03-01

Hommos was treated with gamma radiation and stored at 4 °C for a period of five weeks with the aim of extending its shelf life under refrigeration. Viscosity and colour of the product were evaluated instrumentally at 5-day intervals, and its sensory quality was evaluated by a taste panel at the beginning and end of the storage period. The results indicate that irradiation combined with storage caused reduction of the ΔE*ab, a*, b* and L* colour values, but have no such an effect on the apparent viscosity, flow behavior index (n) or consistency coefficient (k) of the product which exhibited a non-Newtonian, pseudoplastic behavior. Neither irradiation dose nor storage time affected the overall acceptability, flavor, smoothness, mouth- feel and colour of the product when evaluated by a taste panel. The product irradiated with 1.5 or 2.5 kGy can be stored at 4 °C for 35 days and still maintain its sensory and physical qualities indicating that the shelf life of this product, like other irradiated foods, can be extended by this combined treatment.

Cellular projections from sensory hair cells form polarity-specific scaffolds during synaptogenesis

PubMed Central

Dow, Eliot; Siletti, Kimberly

2015-01-01

The assembly of a nervous system requires the extension of axons and dendrites to specific regions where they are matched with appropriate synaptic targets. Although the cues that guide long-range outgrowth have been characterized extensively, additional mechanisms are required to explain short-range guidance in neural development. Using a complementary combination of time-lapse imaging by fluorescence confocal microscopy and serial block-face electron microscopy, we identified a novel type of presynaptic projection that participates in the assembly of the vertebrate nervous system. Synapse formation by each hair cell of the zebrafish's lateral line occurs during a particular interval after the cell's birth. During the same period, projections emerge from the cellular soma, extending toward a specific subpopulation of mature hair cells and interacting with polarity-specific afferent nerve terminals. The terminals then extend along the projections to reach appropriately matched presynaptic sites, after which the projections recede. Our results suggest that presynaptic projections act as transient scaffolds for short-range partner matching, a mechanism that may occur elsewhere in the nervous system. PMID:25995190

Department of Defense Precise Time and Time Interval program improvement plan

NASA Technical Reports Server (NTRS)

Bowser, J. R.

1981-01-01

The United States Naval Observatory is responsible for ensuring uniformity in precise time and time interval operations including measurements, the establishment of overall DOD requirements for time and time interval, and the accomplishment of objectives requiring precise time and time interval with minimum cost. An overview of the objectives, the approach to the problem, the schedule, and a status report, including significant findings relative to organizational relationships, current directives, principal PTTI users, and future requirements as currently identified by the users are presented.

Persistent and susceptible bacteria with individual deaths.

PubMed

Zucca, Fabio

2014-02-21

The aim of this paper is to study two models for a bacterial population subject to antibiotic treatments. It is known that some bacteria are not sensitive to antibiotics. These bacteria, called persisters, are in a state called persistence and each bacterium can switch from this state to a non-persistent (or susceptible) state and back (with rates b and a respectively). Our models extend those introduced in Garet et al. (2012) by adding a random natural life cycle for each bacterium and by allowing bacteria in the susceptible state to escape the action of the antibiotic with a fixed probability 1-p (while every bacterium in a persistent state survives with probability 1). This last mechanism of survival to the antibiotics differs from the persistent state one (where reproduction is forbidden) since in this case the bacterium can replicate. We study two different models. In the first model we "inject" the antibiotics in the system at fixed, deterministic times while in the second one the time intervals are random. We show that, in order to kill eventually the whole bacterial population, these time intervals cannot be "too large". The maximum admissible length is increasing with respect to p; we see that even when p is close to 1, this interval length can be significantly smaller than in the case p=1. While in the case p=1 switching back and forth to the persistent state is the only chance of surviving for bacteria, when p<1 and the death rate in the persistent state, say dr, is positive then the situation is more complex. In this case our model suggests that if dr and b are positive (and fixed) then for higher values of p there is an interval for the rate a, say (0,ap) where switching to the persistent state is a good strategy while for a>ap the situation is less favorable than a=0. On the other hand, for smaller values of p the best strategy is a=0, that is, not switching. Finally, when dr=0, switching to the susceptible state is always a better strategy, from the bacterial point of view, than staying in the susceptible state all the times. Copyright © 2013 Elsevier Ltd. All rights reserved.

Epidemiology meets econometrics: using time-series analysis to observe the impact of bed occupancy rates on the spread of multidrug-resistant bacteria.

PubMed

Kaier, K; Meyer, E; Dettenkofer, M; Frank, U

2010-10-01

Two multivariate time-series analyses were carried out to identify the impact of bed occupancy rates, turnover intervals and the average length of hospital stay on the spread of multidrug-resistant bacteria in a teaching hospital. Epidemiological data on the incidences of meticillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL)-producing bacteria were collected. Time-series of bed occupancy rates, turnover intervals and the average length of stay were tested for inclusion in the models as independent variables. Incidence was defined as nosocomial cases per 1000 patient-days. This included all patients infected or colonised with MRSA/ESBL more than 48h after admission. Between January 2003 and July 2008, a mean incidence of 0.15 nosocomial MRSA cases was identified. ESBL was not included in the surveillance until January 2005. Between January 2005 and July 2008 the mean incidence of nosocomial ESBL was also 0.15 cases per 1000 patient-days. The two multivariate models demonstrate a temporal relationship between bed occupancy rates in general wards and the incidence of nosocomial MRSA and ESBL. Similarly, the temporal relationship between the monthly average length of stay in intensive care units (ICUs) and the incidence of nosocomial MRSA and ESBL was demonstrated. Overcrowding in general wards and long periods of ICU stay were identified as factors influencing the spread of multidrug-resistant bacteria in hospital settings. Copyright 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

Time-dependent reorganization of the brain components underlying memory retention in trace eyeblink conditioning.

PubMed

Takehara, Kaori; Kawahara, Shigenori; Kirino, Yutaka

2003-10-29

Many studies have confirmed the time-limited involvement of the hippocampus in mnemonic processes and suggested that there is reorganization of the responsible brain circuitry during memory consolidation. To clarify such reorganization, we chose trace classical eyeblink conditioning, in which hippocampal ablation produces temporally graded retrograde amnesia. Here, we extended the temporal characterization of retrograde amnesia to other regions that are involved in acquisition during this task: the medial prefrontal cortex (mPFC) and the cerebellum. At a various time interval after establishing the trace conditioned response (CR), rats received an aspiration of one of the three regions. After recovery, the animals were tested for their CR retention. When ablated 1 d after the learning, both the hippocampal lesion and the cerebellar lesion group of rats exhibited a severe impairment in retention of the CR, whereas the mPFC lesion group showed only a slight decline. With an increase in interval between the lesion and the learning, the effect of the hippocampal lesion diminished and that of the mPFC lesion increased. When ablated 4 weeks after the learning, the hippocampal lesion group exhibited as robust CRs as its corresponding control group. In contrast, the mPFC lesion and the cerebellar lesion groups failed to retain the CRs. These results indicate that the hippocampus and the cerebellum, but only marginally the mPFC, constitute a brain circuitry that mediates recently acquired memory. As time elapses, the circuitry is reorganized to use mainly the mPFC and the cerebellum, but not the hippocampus, for remotely acquired memory.

Prognostically favorable abdominal breast cancer metastases with stomach involvement.

PubMed

Akcali, Zafer; Sakalli, Hakan; Ozyilkan, Ozgur; Demirhan, Beyhan; Haberal, Mehmet

2005-05-01

Abdominal metastases with stomach involvement are rare in breast cancer. The median disease free interval from the time of breast cancer diagnosis to gastric metastasis is usually very long. Treatment is generally palliative, and expected survival time is less than 1 year. A 59-year-old woman with breast cancer developed diffuse abdominal metastases involving stomach, abdominal lymph nodes, and omentum 9 years after she underwent mastectomy and adjuvant chemotherapy. The histopathologic diagnosis found by stomach specimen examination was invasive lobular carcinoma, and the cells expressed high levels of estrogen and progesterone receptors. The abdominal metastases were treated with surgery, postoperative chemotherapy, and further hormonal therapy. This was successful, and the patient has been in remission for more than 3 years. Once the definitive diagnosis of breast cancer metastases to the abdomen including the stomach is established, treatment that targets systemic breast cancer must be initiated. Our patient's extended survival time suggests that surgical treatment could be considered for selected patients.

Terahertz dielectric response of photoexcited carriers in Si revealed via single-shot optical-pump and terahertz-probe spectroscopy

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

Minami, Yasuo; Horiuchi, Kohei; Masuda, Kaisei

We have demonstrated accurate observations of terahertz (THz) dielectric response due to photoexcited carriers in a Si plate via single-shot optical-pump and THz-probe spectroscopy. In contrast to conventional THz time-domain spectroscopy, this spectroscopic technique allows single-shot detection of the THz response of materials at a given delay time between the pump and THz pulses, thereby sufficiently extending the time interval between the pump pulses. As a result, we can accurately measure the dielectric properties of materials, while avoiding artifacts in the response caused by the accumulation of long-lived photoexcited carriers. Using our single-shot scheme, the transmittance of a Si platemore » was measured in the range of 0.5–2.5 THz with different pump fluences. Based on a Drude model analysis, the optically induced complex dielectric constant, plasma frequency, and damping rate in the THz region were quantitatively evaluated.« less

4D multiple-cathode ultrafast electron microscopy

PubMed Central

Baskin, John Spencer; Liu, Haihua; Zewail, Ahmed H.

2014-01-01

Four-dimensional multiple-cathode ultrafast electron microscopy is developed to enable the capture of multiple images at ultrashort time intervals for a single microscopic dynamic process. The dynamic process is initiated in the specimen by one femtosecond light pulse and probed by multiple packets of electrons generated by one UV laser pulse impinging on multiple, spatially distinct, cathode surfaces. Each packet is distinctly recorded, with timing and detector location controlled by the cathode configuration. In the first demonstration, two packets of electrons on each image frame (of the CCD) probe different times, separated by 19 picoseconds, in the evolution of the diffraction of a gold film following femtosecond heating. Future elaborations of this concept to extend its capabilities and expand the range of applications of 4D ultrafast electron microscopy are discussed. The proof-of-principle demonstration reported here provides a path toward the imaging of irreversible ultrafast phenomena of materials, and opens the door to studies involving the single-frame capture of ultrafast dynamics using single-pump/multiple-probe, embedded stroboscopic imaging. PMID:25006261

4D multiple-cathode ultrafast electron microscopy.

PubMed

Baskin, John Spencer; Liu, Haihua; Zewail, Ahmed H

2014-07-22

Four-dimensional multiple-cathode ultrafast electron microscopy is developed to enable the capture of multiple images at ultrashort time intervals for a single microscopic dynamic process. The dynamic process is initiated in the specimen by one femtosecond light pulse and probed by multiple packets of electrons generated by one UV laser pulse impinging on multiple, spatially distinct, cathode surfaces. Each packet is distinctly recorded, with timing and detector location controlled by the cathode configuration. In the first demonstration, two packets of electrons on each image frame (of the CCD) probe different times, separated by 19 picoseconds, in the evolution of the diffraction of a gold film following femtosecond heating. Future elaborations of this concept to extend its capabilities and expand the range of applications of 4D ultrafast electron microscopy are discussed. The proof-of-principle demonstration reported here provides a path toward the imaging of irreversible ultrafast phenomena of materials, and opens the door to studies involving the single-frame capture of ultrafast dynamics using single-pump/multiple-probe, embedded stroboscopic imaging.

Delayed benefit of naps on motor learning in preschool children.

PubMed

Desrochers, Phillip C; Kurdziel, Laura B F; Spencer, Rebecca M C

2016-03-01

Sleep benefits memory consolidation across a variety of domains in young adults. However, while declarative memories benefit from sleep in young children, such improvements are not consistently seen for procedural skill learning. Here we examined whether performance improvements on a procedural task, although not immediately observed, are evident after a longer delay when augmented by overnight sleep (24 h after learning). We trained 47 children, aged 33-71 months, on a serial reaction time task and, using a within-subject design, evaluated performance at three time points: immediately after learning, after a daytime nap (nap condition) or equivalent wake opportunity (wake condition), and 24 h after learning. Consistent with previous studies, performance improvements following the nap did not differ from performance improvements following an equivalent interval spent awake. However, significant benefits of the nap were found when performance was assessed 24 h after learning. This research demonstrates that motor skill learning is benefited by sleep, but that this benefit is only evident after an extended period of time.

The Effects of a Local Negative Feedback Function between Choice and Relative Reinforcer Rate

PubMed Central

Davison, Michael; Elliffe, Douglas; Marr, M. Jackson

2010-01-01

Four pigeons were trained on two-key concurrent variable-interval schedules with no changeover delay. In Phase 1, relative reinforcers on the two alternatives were varied over five conditions from .1 to .9. In Phases 2 and 3, we instituted a molar feedback function between relative choice in an interreinforcer interval and the probability of reinforcers on the two keys ending the next interreinforcer interval. The feedback function was linear, and was negatively sloped so that more extreme choice in an interreinforcer interval made it more likely that a reinforcer would be available on the other key at the end of the next interval. The slope of the feedback function was −1 in Phase 2 and −3 in Phase 3. We varied relative reinforcers in each of these phases by changing the intercept of the feedback function. Little effect of the feedback functions was discernible at the local (interreinforcer interval) level, but choice measured at an extended level across sessions was strongly and significantly decreased by increasing the negative slope of the feedback function. PMID:21451748

Accuracy in parameter estimation for targeted effects in structural equation modeling: sample size planning for narrow confidence intervals.

PubMed

Lai, Keke; Kelley, Ken

2011-06-01

In addition to evaluating a structural equation model (SEM) as a whole, often the model parameters are of interest and confidence intervals for those parameters are formed. Given a model with a good overall fit, it is entirely possible for the targeted effects of interest to have very wide confidence intervals, thus giving little information about the magnitude of the population targeted effects. With the goal of obtaining sufficiently narrow confidence intervals for the model parameters of interest, sample size planning methods for SEM are developed from the accuracy in parameter estimation approach. One method plans for the sample size so that the expected confidence interval width is sufficiently narrow. An extended procedure ensures that the obtained confidence interval will be no wider than desired, with some specified degree of assurance. A Monte Carlo simulation study was conducted that verified the effectiveness of the procedures in realistic situations. The methods developed have been implemented in the MBESS package in R so that they can be easily applied by researchers. © 2011 American Psychological Association

Spatiotemporal canards in neural field equations

NASA Astrophysics Data System (ADS)

Avitabile, D.; Desroches, M.; Knobloch, E.

2017-04-01

Canards are special solutions to ordinary differential equations that follow invariant repelling slow manifolds for long time intervals. In realistic biophysical single-cell models, canards are responsible for several complex neural rhythms observed experimentally, but their existence and role in spatially extended systems is largely unexplored. We identify and describe a type of coherent structure in which a spatial pattern displays temporal canard behavior. Using interfacial dynamics and geometric singular perturbation theory, we classify spatiotemporal canards and give conditions for the existence of folded-saddle and folded-node canards. We find that spatiotemporal canards are robust to changes in the synaptic connectivity and firing rate. The theory correctly predicts the existence of spatiotemporal canards with octahedral symmetry in a neural field model posed on the unit sphere.

Fault tolerant and lifetime control architecture for autonomous vehicles

NASA Astrophysics Data System (ADS)

Bogdanov, Alexander; Chen, Yi-Liang; Sundareswaran, Venkataraman; Altshuler, Thomas

2008-04-01

Increased vehicle autonomy, survivability and utility can provide an unprecedented impact on mission success and are one of the most desirable improvements for modern autonomous vehicles. We propose a general architecture of intelligent resource allocation, reconfigurable control and system restructuring for autonomous vehicles. The architecture is based on fault-tolerant control and lifetime prediction principles, and it provides improved vehicle survivability, extended service intervals, greater operational autonomy through lower rate of time-critical mission failures and lesser dependence on supplies and maintenance. The architecture enables mission distribution, adaptation and execution constrained on vehicle and payload faults and desirable lifetime. The proposed architecture will allow managing missions more efficiently by weighing vehicle capabilities versus mission objectives and replacing the vehicle only when it is necessary.

Ratio-based lengths of intervals to improve fuzzy time series forecasting.

PubMed

Huarng, Kunhuang; Yu, Tiffany Hui-Kuang

2006-04-01

The objective of this study is to explore ways of determining the useful lengths of intervals in fuzzy time series. It is suggested that ratios, instead of equal lengths of intervals, can more properly represent the intervals among observations. Ratio-based lengths of intervals are, therefore, proposed to improve fuzzy time series forecasting. Algebraic growth data, such as enrollments and the stock index, and exponential growth data, such as inventory demand, are chosen as the forecasting targets, before forecasting based on the various lengths of intervals is performed. Furthermore, sensitivity analyses are also carried out for various percentiles. The ratio-based lengths of intervals are found to outperform the effective lengths of intervals, as well as the arbitrary ones in regard to the different statistical measures. The empirical analysis suggests that the ratio-based lengths of intervals can also be used to improve fuzzy time series forecasting.

An institutional study of time delays for symptomatic carotid endarterectomy.

PubMed

Charbonneau, Philippe; Bonaventure, Paule Lessard; Drudi, Laura M; Beaudoin, Nathalie; Blair, Jean-François; Elkouri, Stéphane

2016-12-01

The aim of this study was to assess time delays between first cerebrovascular symptoms and carotid endarterectomy (CEA) at a single center and to systematically evaluate causes of these delays. Consecutive adult patients who underwent CEAs between January 2010 and September 2011 at a single university-affiliated center (Centre Hospitalier de l'Université Montréal-Hôtel-Dieu Hospital, Montreal) were identified from a clinical database and operative records. Covariates of interest were extracted from electronic medical records. Timing and nature of the first cerebrovascular symptoms were also documented. The first medical contact and pathway of referral were also assessed. When possible, the ABCD 2 score (age, blood pressure, clinical features, duration of symptoms, and diabetes) was calculated to calculate further risk of stroke. The nonparametric Wilcoxon test was used to assess differences in time intervals between two variables. The Kruskal-Wallis test was used to assess differences in time intervals in comparing more than two variables. A multivariate linear regression analysis was performed using covariates that were determined to be statistically significant in our sensitivity analyses. The cohort consisted of 111 patients with documented symptomatic carotid stenosis undergoing surgical intervention. Thirty-nine percent of all patients were operated on within 2 weeks from the first cerebrovascular symptoms. The median time between the occurrence of the first neurologic symptom and the CEA procedure was 25 (interquartile range [IQR], 11-85) days. The patient-dependent delay, defined as the median delay between the first neurologic symptom and the first medical contact, was 1 (IQR, 0-14) day. The medical-dependent delay was defined as the time interval between the first medical contact and CEA. This included the delay between the first medical contact and the request for surgery consultation (median, 3 [IQR, 1-10] days). The multivariate regression model demonstrated that the emergency physician as referral source (P = .0002) was statistically significant for reducing CEA delay. Patients who were investigated as an outpatient (P = .02), first medical contact with a general practitioner (P = .0002), and hospital center I as referral center (P = .045) were also found to be statistically significant to extend CEA delay when the model was adjusted over all covariates. In this center, there was no correlation between ABCD 2 risk score and waiting time for surgery. The majority of our cohort falls short of the recommended 2-week interval to perform CEA. Factors contributing to reduced CEA delay were presentation to an emergency department, in-patient investigations, and a stroke center where a vascular surgeon is available. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Importance of the Time Interval between Bowel Preparation and Colonoscopy in Determining the Quality of Bowel Preparation for Full-Dose Polyethylene Glycol Preparation

PubMed Central

Kim, Tae Kyung; Kim, Hyung Wook; Kim, Su Jin; Ha, Jong Kun; Jang, Hyung Ha; Hong, Young Mi; Park, Su Bum; Choi, Cheol Woong; Kang, Dae Hwan

2014-01-01

Background/Aims The quality of bowel preparation (QBP) is the important factor in performing a successful colonoscopy. Several factors influencing QBP have been reported; however, some factors, such as the optimal preparation-to-colonoscopy time interval, remain controversial. This study aimed to determine the factors influencing QBP and the optimal time interval for full-dose polyethylene glycol (PEG) preparation. Methods A total of 165 patients who underwent colonoscopy from June 2012 to August 2012 were prospectively evaluated. The QBP was assessed using the Ottawa Bowel Preparation Scale (Ottawa) score according to several factors influencing the QBP were analyzed. Results Colonoscopies with a time interval of 5 to 6 hours had the best Ottawa score in all parts of the colon. Patients with time intervals of 6 hours or less had the better QBP than those with time intervals of more than 6 hours (p=0.046). In the multivariate analysis, the time interval (odds ratio, 1.897; 95% confidence interval, 1.006 to 3.577; p=0.048) was the only significant contributor to a satisfactory bowel preparation. Conclusions The optimal time was 5 to 6 hours for the full-dose PEG method, and the time interval was the only significant contributor to a satisfactory bowel preparation. PMID:25368750

Interresponse Time Structures in Variable-Ratio and Variable-Interval Schedules

ERIC Educational Resources Information Center

Bowers, Matthew T.; Hill, Jade; Palya, William L.

2008-01-01

The interresponse-time structures of pigeon key pecking were examined under variable-ratio, variable-interval, and variable-interval plus linear feedback schedules. Whereas the variable-ratio and variable-interval plus linear feedback schedules generally resulted in a distinct group of short interresponse times and a broad distribution of longer…

Restoring platinum sensitivity in recurrent ovarian cancer by extending the platinum-free interval: Myth or reality?

PubMed

Tomao, Federica; D'Incalci, Maurizio; Biagioli, Elena; Peccatori, Fedro A; Colombo, Nicoletta

2017-09-15

The platinum-free interval is the most important predictive factor of a response to subsequent lines of chemotherapy and the most important prognostic factor for progression-free and overall survival in patients with recurrent epithelial ovarian cancer. A nonplatinum regimen is generally considered the most appropriate approach when the disease recurs very early after the end of chemotherapy, whereas platinum-based chemotherapy is usually adopted when the platinum-free interval exceeds 12 months. However, the therapeutic management of patients with intermediate sensitivity (ie, when the relapse occurs between 6 and 12 months) remains debatable. Preclinical and clinical data suggest that the extension of platinum-free interval (using a nonplatinum-based regimen) might restore platinum sensitivity, thus allowing survival improvement. The objective of this review was to critically analyze preclinical and clinical evidences supporting this hypothesis. Cancer 2017;123:3450-9. © 2017 American Cancer Society. © 2017 American Cancer Society.

Towards a European tephrochronological framework for Termination 1 and the Early Holocene.

PubMed

Davies, Siwan M; Branch, Nicholas P; Lowe, J John; Turney, Chris S M

2002-04-15

The record of deposition of tephras in Europe and the North Atlantic during the period 18.5-8.0 (14)C ka BP (the Last Termination and Early Holocene) is reviewed. Altogether, 34 tephras originating from four main volcanic provinces (Iceland, the Eifel district, the Massif Central and Italy) have been identified so far in geological sequences spanning this time-interval. Most of the records have been based, until very recently, on observations of visible layers of tephras. Here, we report on the potential for extending the areas over which some of the tephras can be traced by the search for layers of micro-tephra, which are not visible to the naked eye, and on the use of geochemical methods to correlate them with known tephra horizons. This approach has greatly extended the area in Northern Europe over which the Vedde Ash can be traced. The same potential exists in southern Europe, which is demonstrated for the first time by the discovery of a distinct layer of micro-tephra of the Neapolitan Yellow Tuff in a site in the Northern Apennines in Italy, far to the north of the occurrences of visible records of this tephra. The paper closes by considering the potential for developing a robust European tephrostratigraphy to underpin the chronology of records of the Last Termination and Early Holocene, thereby promoting a better understanding of the nature, timing and environmental effects of the abrupt climatic changes that characterized this period.

Evaluation of digital dental models obtained from dental cone-beam computed tomography scan of alginate impressions

PubMed Central

Jiang, Tingting; Lee, Sang-Mi; Hou, Yanan; Chang, Xin

2016-01-01

Objective To investigate the dimensional accuracy of digital dental models obtained from the dental cone-beam computed tomography (CBCT) scan of alginate impressions according to the time elapse when the impressions are stored under ambient conditions. Methods Alginate impressions were obtained from 20 adults using 3 different alginate materials, 2 traditional alginate materials (Alginoplast and Cavex Impressional) and 1 extended-pour alginate material (Cavex ColorChange). The impressions were stored under ambient conditions, and scanned by CBCT immediately after the impressions were taken, and then at 1 hour intervals for 6 hours. After reconstructing three-dimensional digital dental models, the models were measured and the data were analyzed to determine dimensional changes according to the elapsed time. The changes within the measurement error were regarded as clinically acceptable in this study. Results All measurements showed a decreasing tendency with an increase in the elapsed time after the impressions. Although the extended-pour alginate exhibited a less decreasing tendency than the other 2 materials, there were no statistically significant differences between the materials. Changes above the measurement error occurred between the time points of 3 and 4 hours after the impressions. Conclusions The results of this study indicate that digital dental models can be obtained simply from a CBCT scan of alginate impressions without sending them to a remote laboratory. However, when the impressions are not stored under special conditions, they should be scanned immediately, or at least within 2 to 3 hours after the impressions are taken. PMID:27226958

Not All Prehospital Time is Equal: Influence of Scene Time on Mortality

PubMed Central

Brown, Joshua B.; Rosengart, Matthew R.; Forsythe, Raquel M.; Reynolds, Benjamin R.; Gestring, Mark L.; Hallinan, William M.; Peitzman, Andrew B.; Billiar, Timothy R.; Sperry, Jason L.

2016-01-01

Background Trauma is time-sensitive and minimizing prehospital (PH) time is appealing. However, most studies have not linked increasing PH time with worse outcomes, as raw PH times are highly variable. It is unclear whether specific PH time patterns affect outcomes. Our objective was to evaluate the association of PH time interval distribution with mortality. Methods Patients transported by EMS in the Pennsylvania trauma registry 2000-2013 with total prehospital time (TPT)≥20min were included. TPT was divided into three PH time intervals: response, scene, and transport time. The number of minutes in each PH time interval was divided by TPT to determine the relative proportion each interval contributed to TPT. A prolonged interval was defined as any one PH interval contributing ≥50% of TPT. Patients were classified by prolonged PH interval or no prolonged PH interval (all intervals<50% of TPT). Patients were matched for TPT and conditional logistic regression determined the association of mortality with PH time pattern, controlling for confounders. PH interventions were explored as potential mediators, and prehospital triage criteria used identify patients with time-sensitive injuries. Results There were 164,471 patients included. Patients with prolonged scene time had increased odds of mortality (OR 1.21; 95%CI 1.02–1.44, p=0.03). Prolonged response, transport, and no prolonged interval were not associated with mortality. When adjusting for mediators including extrication and PH intubation, prolonged scene time was no longer associated with mortality (OR 1.06; 0.90–1.25, p=0.50). Together these factors mediated 61% of the effect between prolonged scene time and mortality. Mortality remained associated with prolonged scene time in patients with hypotension, penetrating injury, and flail chest. Conclusions Prolonged scene time is associated with increased mortality. PH interventions partially mediate this association. Further study should evaluate whether these interventions drive increased mortality because they prolong scene time or by another mechanism, as reducing scene time may be a target for intervention. Level of Evidence IV, prognostic study PMID:26886000

Artificial intelligence: a new approach for prescription and monitoring of hemodialysis therapy.

PubMed

Akl, A I; Sobh, M A; Enab, Y M; Tattersall, J

2001-12-01

The effect of dialysis on patients is conventionally predicted using a formal mathematical model. This approach requires many assumptions of the processes involved, and validation of these may be difficult. The validity of dialysis urea modeling using a formal mathematical model has been challenged. Artificial intelligence using neural networks (NNs) has been used to solve complex problems without needing a mathematical model or an understanding of the mechanisms involved. In this study, we applied an NN model to study and predict concentrations of urea during a hemodialysis session. We measured blood concentrations of urea, patient weight, and total urea removal by direct dialysate quantification (DDQ) at 30-minute intervals during the session (in 15 chronic hemodialysis patients). The NN model was trained to recognize the evolution of measured urea concentrations and was subsequently able to predict hemodialysis session time needed to reach a target solute removal index (SRI) in patients not previously studied by the NN model (in another 15 chronic hemodialysis patients). Comparing results of the NN model with the DDQ model, the prediction error was 10.9%, with a not significant difference between predicted total urea nitrogen (UN) removal and measured UN removal by DDQ. NN model predictions of time showed a not significant difference with actual intervals needed to reach the same SRI level at the same patient conditions, except for the prediction of SRI at the first 30-minute interval, which showed a significant difference (P = 0.001). This indicates the sensitivity of the NN model to what is called patient clearance time; the prediction error was 8.3%. From our results, we conclude that artificial intelligence applications in urea kinetics can give an idea of intradialysis profiling according to individual clinical needs. In theory, this approach can be extended easily to other solutes, making the NN model a step forward to achieving artificial-intelligent dialysis control.

Inter-plate aseismic slip on the subducting plate boundaries estimated from repeating earthquakes

NASA Astrophysics Data System (ADS)

Igarashi, T.

2015-12-01

Sequences of repeating earthquakes are caused by repeating slips of small patches surrounded by aseismic slip areas at plate boundary zones. Recently, they have been detected in many regions. In this study, I detected repeating earthquakes which occurred in Japan and the world by using seismograms observed in the Japanese seismic network, and investigated the space-time characteristics of inter-plate aseismic slip on the subducting plate boundaries. To extract repeating earthquakes, I calculate cross-correlation coefficients of band-pass filtering seismograms at each station following Igarashi [2010]. I used two data-set based on USGS catalog for about 25 years from May 1990 and JMA catalog for about 13 years from January 2002. As a result, I found many sequences of repeating earthquakes in the subducting plate boundaries of the Andaman-Sumatra-Java and Japan-Kuril-Kamchatka-Aleutian subduction zones. By applying the scaling relations among a seismic moment, recurrence interval and slip proposed by Nadeau and Johnson [1998], they indicate the space-time changes of inter-plate aseismic slips. Pairs of repeating earthquakes with the longest time interval occurred in the Solomon Islands area and the recurrence interval was about 18.5 years. The estimated slip-rate is about 46 mm/year, which correspond to about half of the relative plate motion in this area. Several sequences with fast slip-rates correspond to the post-seismic slips after the 2004 Sumatra-Andaman earthquake (M9.0), the 2006 Kuril earthquake (M8.3), the 2007 southern Sumatra earthquake (M8.5), and the 2011 Tohoku-oki earthquake (M9.0). The database of global repeating earthquakes enables the comparison of the inter-plate aseismic slips of various plate boundary zones of the world. I believe that I am likely to detect more sequences by extending analysis periods in the area where they were not found in this analysis.

Time interval measurement device based on surface acoustic wave filter excitation, providing 1 ps precision and stability.

PubMed

Panek, Petr; Prochazka, Ivan

2007-09-01

This article deals with the time interval measurement device, which is based on a surface acoustic wave (SAW) filter as a time interpolator. The operating principle is based on the fact that a transversal SAW filter excited by a short pulse can generate a finite signal with highly suppressed spectra outside a narrow frequency band. If the responses to two excitations are sampled at clock ticks, they can be precisely reconstructed from a finite number of samples and then compared so as to determine the time interval between the two excitations. We have designed and constructed a two-channel time interval measurement device which allows independent timing of two events and evaluation of the time interval between them. The device has been constructed using commercially available components. The experimental results proved the concept. We have assessed the single-shot time interval measurement precision of 1.3 ps rms that corresponds to the time of arrival precision of 0.9 ps rms in each channel. The temperature drift of the measured time interval on temperature is lower than 0.5 ps/K, and the long term stability is better than +/-0.2 ps/h. These are to our knowledge the best values reported for the time interval measurement device. The results are in good agreement with the error budget based on the theoretical analysis.

Interval Timing Accuracy and Scalar Timing in C57BL/6 Mice

PubMed Central

Buhusi, Catalin V.; Aziz, Dyana; Winslow, David; Carter, Rickey E.; Swearingen, Joshua E.; Buhusi, Mona C.

2010-01-01

In many species, interval timing behavior is accurate—appropriate estimated durations—and scalar—errors vary linearly with estimated durations. While accuracy has been previously examined, scalar timing has not been yet clearly demonstrated in house mice (Mus musculus), raising concerns about mouse models of human disease. We estimated timing accuracy and precision in C57BL/6 mice, the most used background strain for genetic models of human disease, in a peak-interval procedure with multiple intervals. Both when timing two intervals (Experiment 1) or three intervals (Experiment 2), C57BL/6 mice demonstrated varying degrees of timing accuracy. Importantly, both at individual and group level, their precision varied linearly with the subjective estimated duration. Further evidence for scalar timing was obtained using an intraclass correlation statistic. This is the first report of consistent, reliable scalar timing in a sizable sample of house mice, thus validating the PI procedure as a valuable technique, the intraclass correlation statistic as a powerful test of the scalar property, and the C57BL/6 strain as a suitable background for behavioral investigations of genetically engineered mice modeling disorders of interval timing. PMID:19824777

Assessment of cardiac time intervals using high temporal resolution real-time spiral phase contrast with UNFOLDed-SENSE.

PubMed

Kowalik, Grzegorz T; Knight, Daniel S; Steeden, Jennifer A; Tann, Oliver; Odille, Freddy; Atkinson, David; Taylor, Andrew; Muthurangu, Vivek

2015-02-01

To develop a real-time phase contrast MR sequence with high enough temporal resolution to assess cardiac time intervals. The sequence utilized spiral trajectories with an acquisition strategy that allowed a combination of temporal encoding (Unaliasing by fourier-encoding the overlaps using the temporal dimension; UNFOLD) and parallel imaging (Sensitivity encoding; SENSE) to be used (UNFOLDed-SENSE). An in silico experiment was performed to determine the optimum UNFOLD filter. In vitro experiments were carried out to validate the accuracy of time intervals calculation and peak mean velocity quantification. In addition, 15 healthy volunteers were imaged with the new sequence, and cardiac time intervals were compared to reference standard Doppler echocardiography measures. For comparison, in silico, in vitro, and in vivo experiments were also carried out using sliding window reconstructions. The in vitro experiments demonstrated good agreement between real-time spiral UNFOLDed-SENSE phase contrast MR and the reference standard measurements of velocity and time intervals. The protocol was successfully performed in all volunteers. Subsequent measurement of time intervals produced values in keeping with literature values and good agreement with the gold standard echocardiography. Importantly, the proposed UNFOLDed-SENSE sequence outperformed the sliding window reconstructions. Cardiac time intervals can be successfully assessed with UNFOLDed-SENSE real-time spiral phase contrast. Real-time MR assessment of cardiac time intervals may be beneficial in assessment of patients with cardiac conditions such as diastolic dysfunction. © 2014 Wiley Periodicals, Inc.

Estimating time-varying drug adherence using electronic records: extending the proportion of days covered (PDC) method.

PubMed

Bijlsma, Maarten J; Janssen, Fanny; Hak, Eelko

2016-03-01

Accurate measurement of drug adherence is essential for valid risk-benefit assessments of pharmacologic interventions. To date, measures of drug adherence have almost exclusively been applied for a fixed-time interval and without considering changes over time. However, patients with irregular dosing behaviour commonly have a different prognosis than patients with stable dosing behaviour. We propose a method, based on the proportion of days covered (PDC) method, to measure time-varying drug adherence and drug dosage using electronic records. We compare a time-fixed PDC method with the time-varying PDC method through detailed examples and through summary statistics of 100 randomly selected patients on statin therapy. We demonstrate that time-varying PDC method better distinguishes an irregularly dosing patient from a stably dosing patient and demonstrate how the time-fixed method can result in a biassed estimate of drug adherence. Furthermore, the time-varying PDC method may be better used to reduce certain types of confounding and misclassification of exposure. The time-varying PDC method may improve longitudinal and time-to-event studies that associate adherence with a clinical outcome or (intervention) studies that seek to describe changes in adherence over time. Copyright © 2015 John Wiley & Sons, Ltd.

VARIABLE TIME-INTERVAL GENERATOR

DOEpatents

Gross, J.E.

1959-10-31

This patent relates to a pulse generator and more particularly to a time interval generator wherein the time interval between pulses is precisely determined. The variable time generator comprises two oscillators with one having a variable frequency output and the other a fixed frequency output. A frequency divider is connected to the variable oscillator for dividing its frequency by a selected factor and a counter is used for counting the periods of the fixed oscillator occurring during a cycle of the divided frequency of the variable oscillator. This defines the period of the variable oscillator in terms of that of the fixed oscillator. A circuit is provided for selecting as a time interval a predetermined number of periods of the variable oscillator. The output of the generator consists of a first pulse produced by a trigger circuit at the start of the time interval and a second pulse marking the end of the time interval produced by the same trigger circuit.

In vitro stimulation with a strongly pulsed electromagnetic field on rat basophilic leukemia cells

NASA Astrophysics Data System (ADS)

Choi, J. W.; Shin, S. C.; Kim, S.; Chung, E. R.; Bang, J. H.; Cho, G. I.; Choi, S. D.; Park, Y. S.; Jang, T. S.; Yoo, Y. M.; Lee, S. S.; Hwang, D. G.

2010-05-01

In this study, the effects of pulsed electromagnetic field stimulation with a strong magnetic field on rat basophilic leukemia (RBL-2H3) cells were investigated to confirm the efficacy of the magnetic stimulator for biomedical applications. The maximum intensity of the magnetic field generated from the stimulation coil was 0.203 T, and the transition time was 126 μs. The oscillation time and frequency of the pulsed field were almost 0.1 ms and 8 kHz, respectively. The cell count as well as the mRNA expression and DNA sequence of the cytokine genes, such as the tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4), of the stimulated RBL-2H3 cells were analyzed with a hemocytometer and via reverse transcriptase polymerase chain reaction to determine the physiological response under a strong pulse field. After 12 h stimulation, cell death was observed at an increasing scale with the increase in the stimulation time. On the other hand, the cells that were stimulated for 10 min almost doubled as the interval time between the stimulations was extended.

Spatial and temporal trends in fin whale vocalizations recorded in the NE Pacific Ocean between 2003-2013

PubMed Central

Weirathmueller, Michelle J.; Stafford, Kathleen M.; Wilcock, William S. D.; Hilmo, Rose S.; Dziak, Robert P.; Tréhu, Anne M.

2017-01-01

In order to study the long-term stability of fin whale (Balaenoptera physalus) singing behavior, the frequency and inter-pulse interval of fin whale 20 Hz vocalizations were observed over 10 years from 2003–2013 from bottom mounted hydrophones and seismometers in the northeast Pacific Ocean. The instrument locations extended from 40°N to 48°N and 130°W to 125°W with water depths ranging from 1500–4000 m. The inter-pulse interval (IPI) of fin whale song sequences was observed to increase at a rate of 0.54 seconds/year over the decade of observation. During the same time period, peak frequency decreased at a rate of 0.17 Hz/year. Two primary call patterns were observed. During the earlier years, the more commonly observed pattern had a single frequency and single IPI. In later years, a doublet pattern emerged, with two dominant frequencies and IPIs. Many call sequences in the intervening years appeared to represent a transitional state between the two patterns. The overall trend was consistent across the entire geographical span, although some regional differences exist. Understanding changes in acoustic behavior over long time periods is needed to help establish whether acoustic characteristics can be used to help determine population identity in a widely distributed, difficult to study species such as the fin whale. PMID:29073230

Spatial and temporal trends in fin whale vocalizations recorded in the NE Pacific Ocean between 2003-2013.

PubMed

Weirathmueller, Michelle J; Stafford, Kathleen M; Wilcock, William S D; Hilmo, Rose S; Dziak, Robert P; Tréhu, Anne M

2017-01-01

In order to study the long-term stability of fin whale (Balaenoptera physalus) singing behavior, the frequency and inter-pulse interval of fin whale 20 Hz vocalizations were observed over 10 years from 2003-2013 from bottom mounted hydrophones and seismometers in the northeast Pacific Ocean. The instrument locations extended from 40°N to 48°N and 130°W to 125°W with water depths ranging from 1500-4000 m. The inter-pulse interval (IPI) of fin whale song sequences was observed to increase at a rate of 0.54 seconds/year over the decade of observation. During the same time period, peak frequency decreased at a rate of 0.17 Hz/year. Two primary call patterns were observed. During the earlier years, the more commonly observed pattern had a single frequency and single IPI. In later years, a doublet pattern emerged, with two dominant frequencies and IPIs. Many call sequences in the intervening years appeared to represent a transitional state between the two patterns. The overall trend was consistent across the entire geographical span, although some regional differences exist. Understanding changes in acoustic behavior over long time periods is needed to help establish whether acoustic characteristics can be used to help determine population identity in a widely distributed, difficult to study species such as the fin whale.

Exploring the impact of high intensity interval training on adolescents' objectively measured physical activity: Findings from a randomized controlled trial.

PubMed

Costigan, Sarah A; Ridgers, Nicola D; Eather, Narelle; Plotnikoff, Ronald C; Harris, Nigel; Lubans, David R

2018-05-01

High Intensity Interval Training (HIIT) may be effective for accumulating VPA. However, the contribution of HIIT to overall physical activity is unknown. Our primary aim was to explore the impact of school-based HIIT on physical activity. The secondary aim was to explore within-individual changes in physical activity after participating in HIIT. Participants [n = 65; 15.8(0.6)years] were randomized to a HIIT or control group. Intervention groups participated in three HIIT sessions/week. GENEActiv accelerometers assessed objective physical activity at baseline and week-one, to detect changes in MPA and VPA. Intervention effects were examined using linear mixed models and evidence of a change in physical activity (i.e., compensation) were examined using multilevel linear regression models. The group-by-time interaction effects for MPA and VPA were small and moderate, respectively. Adjusted difference between groups for VPA was 1.70 min/day, 95%CI -1.96 to 5.36; p = 0.354; d = 0.55). Embedding HIIT within the school-day had a moderate effect on VPA compared to controls. Compensation analyses (i.e., individual level) suggested that adolescents were more active on days when they participated in HIIT. Further studies are needed to test the effects of HIIT on adolescents' physical activity over extended time periods.

Composite carbohydrate interpenetrating polyelectrolyte nano-complexes (IPNC) as a controlled oral delivery system of citalopram HCl for pediatric use: in-vitro/in-vivo evaluation and histopathological examination.

PubMed

Kamel, Rabab; Abbas, Haidy; El-Naa, Mona

2018-06-01

Citalopram HCl (CH) is one of the few drugs which can be used safely in childhood psychiatric disorders. This study was focused on the preparation of interpenetrating polyelectrolytes nano-complexes (IPNC) to transform the hydrophilic carbohydrate polymers into an insoluble form. The IPNCs were loaded with CH to sustain its effect. The IPNC2 (composed of chitosan:pectin in a 3:1 ratio) showed the most extended drug release pattern (P < 0.05) and followed a Higuchi-order kinetics model. It was characterized using SEM, X-rays diffractometry, and FTIR. In-vivo studies were performed using immature rats with induced depression, and were based on the investigation of behavioral, biochemical, and histopathological changes at different time intervals up to 24 h. Rats treated with IPNC2 showed a significant more rapid onset of action and more extended effect in the behavioral tests, in addition to a significantly higher serotonin brain level up to 24 h, compared to rats treated with the market product (P < 0.05). The histopathological examination showed a profound amelioration of the cerebral cortex features of the depressed rats after IPNC2 administration. This study proves the higher efficacy and more extended effect of the new polyelectrolytes nano-complexes compared to the market product.

High charge state carbon and oxygen ions in Earth's equatorial quasi-trapping region

NASA Technical Reports Server (NTRS)

Christon, S. P.; Hamilton, D. C.; Gloeckler, G.; Eastmann, T. E.

1994-01-01

Observations of energetic (1.5 - 300 keV/e) medium-to-high charge state (+3 less than or equal to Q less than or equal to +7) solar wind origin C and O ions made in the quasi-trapping region (QTR) of Earth's magnetosphere are compared to ion trajectories calculated in model equatorial magnetospheric magnetic and electric fields. These comparisons indicate that solar wind ions entering the QTR on the nightside as an energetic component of the plasma sheet exit the region on the dayside, experiencing little or no charge exchange on the way. Measurements made by the CHarge Energy Mass (CHEM) ion spectrometer on board the Active Magnetospheric Particle Tracer Explorer/Charge Composition Explorer (AMPTE/CCE) spacecraft at 7 less than L less than 9 from September 1984 to January 1989 are the source of the new results contained herein: quantitative long-term determination of number densities, average energies, energy spectra, local time distributions, and their variation with geomagnetic disturbance level as indexed by Kp. Solar wind primaries (ions with charge states unchanged) and their secondaries (ions with generally lower charge states produced from primaries in the magnetosphere via charge exchange)are observed throughout the QTR and have distinctly different local time variations that persist over the entire 4-year analysis interval. During Kp larger than or equal to 3 deg intervals, primary ion (e.g., O(+6)) densities exhibit a pronounced predawn maximum with average energy minimum and a broad near-local-noon density minimum with average energy maximum. Secondary ion (e.g., O(+5)) densities do not have an identifiable predawn peak, rather they have a broad dayside maximum peaked in local morning and a nightside minimum. During Kp less than or equal to 2(-) intervals, primary ion density peaks are less intense, broader in local time extent, and centered near midnight, while secondary ion density local time variations diminish. The long-time-interval baseline helps to refine and extend previous observations; for example, we show that ionospheric contribution to O(+3)) is negligible. Through comparison with model ion trajectories, we interpret the lack of pronounced secondary ion density peaks colocated with the primary density peaks to indicate that: (1) negligible charge exchange occurs at L greater than 7, that is, solar wind secondaries are produced at L less than 7, and (2) solar wind secondaries do not form a significant portion of the plasma sheet population injected into the QTR. We conclude that little of the energetic solar wind secondary ion population is recirculated through the magnetosphere.

Electron trapping in evolving coronal structures during a large gradual hard X-ray/radio burst

NASA Technical Reports Server (NTRS)

Bruggmann, G.; Vilmer, N.; Klein, K.-L.; Kane, S. R.

1994-01-01

Gradual hard X-ray/radio bursts are characterized by their long duration, smooth time profile, time delays between peaks at different hard X-ray energies and microwaves, and radiation from extended sources in the low and middle corona. Their characteristic properties have been ascribed to the dynamic evolution of the accelerated electrons in coronal magnetic traps or to the separate acceleration of high-energy electrons in a 'second step' process. The information available so far was drawn from quality considerations of time profiles or even only from the common occurrence of emissions in different spectral ranges. This paper presents model computations of the temporal evolution of hard X-ray and microwave spectra, together with a qualitative discussion of radio lightcurves over a wide spectral range, and metric imaging observations. The basis hypothesis investigated is that the peculiar 'gradual' features can be related to the dynamical evolution of electrons injected over an extended time interval in a coronal trap, with electrons up to relativistic energies being injected simultaneously. The analyzed event (26 April. 1981) is particularly challenging to this hypothesis because of the long time delays between peaks at different X-ray energies and microwave frequencies. The observations are shown to be consistent with the hypothesis, provided that the electrons lose their energy by Coulomb collisions and possibly betatron deceleration. The access of the electrons to different coronal structures varies in the course of the event. The evolution and likely destabilization of part of the coronal plasma-magnetic field configuration is of crucial influence in determining the access to these structures and possibly the dynamical evolution of the trapped electrons through betatron deceleration in the late phase of the event.

Intact interval timing in circadian CLOCK mutants.

PubMed

Cordes, Sara; Gallistel, C R

2008-08-28

While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval-timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/- and -/- mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing.

Travel Time Tomographic Imaging of Shallow Fore-arc Basin Structure at the Cascadia Subduction Zone Offshore Washington and Oregon

NASA Astrophysics Data System (ADS)

Azarm, R.; Carton, H. D.; Carbotte, S. M.; Han, S.; Canales, J. P.; Nedimovic, M. R.

2016-12-01

We conduct a P-wave tomography study of shallow fore-arc basin structure at the Cascadia subduction zone using first-arrival travel times from two multi-channel seismic (MCS) profiles acquired with an 8-km long streamer in the frame of the 2012 Juan de Fuca Ridge to Trench program. The first profile extends offshore Gray's Harbor in Washington and the second extends offshore Oregon at the latitude of Hydrate ridge, with the fore-arc basin imaged below ˜60 and ˜70-km long shallow water (< 500 m) portions of these profiles, respectively. We use the travel time tomography method of VanAvendonk et al. [2004], which is based on the shortest path method for ray tracing, and iterative inversions driven by gradual reduction of the chi-square misfit (root mean square value of the difference between predicted and observed travel times normalized by pick uncertainty). We construct our starting model by hanging from the seafloor a 1D velocity profile based on interval velocities derived from semblance analysis of MCS data. Resolvability of the final model is assessed using checkerboard pattern tests with different anomaly sizes. We then compare our tomographically-derived velocity models to coincident seismic reflection images post-stack time migrated and converted to depth using our results. On the Washington shelf, where the fore-arc basin is segmented into three sub-basins, ray coverage mostly extends to ˜1.2-1.5 km below seafloor. Velocities in the shallowmost sediments show, at the large scale, a gradual decrease towards the shelf edge (from 2.1 to 1.8 km/s). At depth, regions devoid of clear reflections such as an ˜5 km large anticline core are associated with lower velocities than that obtained within mildly deformed sedimentary layers on either side (2.3 vs 2.7 km/s, measured at 1.2 km depth), suggesting the presence of localized fluid-rich regions within the basin. Analysis of the Oregon line is ongoing and results will be presented at the meeting.

Relative time sharing: new findings and an extension of the resource allocation model of temporal processing.

PubMed

Buhusi, Catalin V; Meck, Warren H

2009-07-12

Individuals time as if using a stopwatch that can be stopped or reset on command. Here, we review behavioural and neurobiological data supporting the time-sharing hypothesis that perceived time depends on the attentional and memory resources allocated to the timing process. Neuroimaging studies in humans suggest that timekeeping tasks engage brain circuits typically involved in attention and working memory. Behavioural, pharmacological, lesion and electrophysiological studies in lower animals support this time-sharing hypothesis. When subjects attend to a second task, or when intruder events are presented, estimated durations are shorter, presumably due to resources being taken away from timing. Here, we extend the time-sharing hypothesis by proposing that resource reallocation is proportional to the perceived contrast, both in temporal and non-temporal features, between intruders and the timed events. New findings support this extension by showing that the effect of an intruder event is dependent on the relative duration of the intruder to the intertrial interval. The conclusion is that the brain circuits engaged by timekeeping comprise not only those primarily involved in time accumulation, but also those involved in the maintenance of attentional and memory resources for timing, and in the monitoring and reallocation of those resources among tasks.

FIRE I - Extended Time Observations Data Sets

Atmospheric Science Data Center

2017-12-21

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

A real-time method for autonomous passive acoustic detection-classification of humpback whales.

PubMed

Abbot, Ted A; Premus, Vincent E; Abbot, Philip A

2010-05-01

This paper describes a method for real-time, autonomous, joint detection-classification of humpback whale vocalizations. The approach adapts the spectrogram correlation method used by Mellinger and Clark [J. Acoust. Soc. Am. 107, 3518-3529 (2000)] for bowhead whale endnote detection to the humpback whale problem. The objective is the implementation of a system to determine the presence or absence of humpback whales with passive acoustic methods and to perform this classification with low false alarm rate in real time. Multiple correlation kernels are used due to the diversity of humpback song. The approach also takes advantage of the fact that humpbacks tend to vocalize repeatedly for extended periods of time, and identification is declared only when multiple song units are detected within a fixed time interval. Humpback whale vocalizations from Alaska, Hawaii, and Stellwagen Bank were used to train the algorithm. It was then tested on independent data obtained off Kaena Point, Hawaii in February and March of 2009. Results show that the algorithm successfully classified humpback whales autonomously in real time, with a measured probability of correct classification in excess of 74% and a measured probability of false alarm below 1%.

Clinical evaluation of pacemaker automatic capture management and atrioventricular interval extension algorithm.

PubMed

Chen, Ke-ping; Xu, Geng; Wu, Shulin; Tang, Baopeng; Wang, Li; Zhang, Shu

2013-03-01

The present study was to assess the accuracy of automatic atrial and ventricular capture management (ACM and VCM) in determining pacing threshold and the performance of a second-generation automatic atrioventricular (AV) interval extension algorithm for reducing unnecessary ventricular pacing. A total of 398 patients at 32 centres who received an EnPulse dual-chamber pacing/dual-chamber adaptive rate pacing pacemaker (Medtronic, Minneapolis, MN, USA) were enrolled. The last amplitude thresholds as measured by ACM and VCM prior to the 6-month follow-up were compared with manually measured thresholds. Device diagnostics were used to evaluate ACM and VCM and the percentage of ventricular pacing with and without the AV extension algorithm. Modelling was performed to assess longevity gains relating to the use of automaticity features. Atrial and ventricular capture management performed accurately and reliably provided complete capture management in 97% of studied patients. The AV interval extension algorithm reduced the median per cent of right ventricular pacing in patients with sinus node dysfunction from 99.7 to 1.5% at 6-month follow-up and in patients with intermittent AV block (excluding persistent 3° AV block) from 99.9 to 50.2%. On the basis of validated modelling, estimated device longevity could potentially be extended by 1.9 years through the use of the capture management and AV interval extension features. Both ACM and VCM features reliably measured thresholds in nearly all patients; the AV extension algorithm significantly reduced ventricular pacing; and the use of pacemaker automaticity features potentially extends device longevity.

Regional hippocampal volumes and development predict learning and memory.

PubMed

Tamnes, Christian K; Walhovd, Kristine B; Engvig, Andreas; Grydeland, Håkon; Krogsrud, Stine K; Østby, Ylva; Holland, Dominic; Dale, Anders M; Fjell, Anders M

2014-01-01

The hippocampus is an anatomically and functionally heterogeneous structure, but longitudinal studies of its regional development are scarce and it is not known whether protracted maturation of the hippocampus in adolescence is related to memory development. First, we investigated hippocampal subfield development using 170 longitudinally acquired brain magnetic resonance imaging scans from 85 participants aged 8-21 years. Hippocampal subfield volumes were estimated by the use of automated segmentation of 7 subfields, including the cornu ammonis (CA) sectors and the dentate gyrus (DG), while longitudinal subfield volumetric change was quantified using a nonlinear registration procedure. Second, associations between subfield volumes and change and verbal learning/memory across multiple retention intervals (5 min, 30 min and 1 week) were tested. It was hypothesized that short and intermediate memory would be more closely related to CA2-3/CA4-DG and extended, remote memory to CA1. Change rates were significantly different across hippocampal subfields, but nearly all subfields showed significant volume decreases over time throughout adolescence. Several subfield volumes were larger in the right hemisphere and in males, while for change rates there were no hemisphere or sex differences. Partly in support of the hypotheses, greater volume of CA1 and CA2-3 was related to recall and retention after an extended delay, while longitudinal reduction of CA2-3 and CA4-DG was related to learning. This suggests continued regional development of the hippocampus across adolescence and that volume and volume change in specific subfields differentially predict verbal learning and memory over different retention intervals, but future high-resolution studies are called for. © 2014 S. Karger AG, Basel.

On the azimuthal size of flux ropes near lunar orbit

NASA Astrophysics Data System (ADS)

Kiehas, S. A.; Angelopoulos, V.; Runov, A.; Li, S.-S.

2013-07-01

We present Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) dual-probe observations of flux ropes in the Earth's magnetotail near lunar orbit. On 15 July 2011 between 0400 and 0500 UT, the ARTEMIS probes (P1 and P2) are separated by ˜ (9/10/3) RE(XGSW/YGSW/ZGSW). GSW denotes the Geocentric Solar Wind coordinate system and differs from the GSM coordinate system in that its X axis is antiparallel to the solar wind. P1 is near midnight and P2 in the postmidnight sector at ˜ -13 RE YGSW. During a ˜ 50 min interval on 15 July 2011, P1 crossed the current sheet and encountered a flux rope thereafter. During the same interval, P2 observed only one flux rope near the time P1 crossed the current sheet but no flux rope or traveling compression region (TCR) for P1's subsequent flux rope observation. A Tsyganenko-Fairfield model and minimum variance analysis during the current sheet crossing are used to infer the current sheet location with respect to the probes. We find the distance between P2 and the plasma sheet boundary to be less than 3 RE. Under these circumstances, P2 would be expected to observe a TCR if the flux rope observed by P1 extended to the postmidnight location of P2. The lack of such observations indicates that, contrary to previous models and simulation results, flux ropes may be spatially confined in the dusk-dawn direction and do not extend across the entire cross section of the tail near lunar orbit.

Strong IMF By-Related Plasma Convection in the Ionosphere and Cusp Field-Aligned Currents Under Northward IMF Conditions

NASA Technical Reports Server (NTRS)

Le, G.; Lu, G.; Strangeway, R. J.; Pfaff, R. F., Jr.; Vondrak, Richard R. (Technical Monitor)

2001-01-01

We present in this paper an investigation of IMF-By related plasma convection and cusp field-aligned currents using FAST data and AMIE model during a prolonged interval with large positive IMF By and northward Bz conditions (By/Bz much greater than 1). Using the FAST single trajectory observations to validate the global convection patterns at key times and key locations, we have demonstrated that the AMIE procedure provides a reasonably good description of plasma circulations in the ionosphere during this interval. Our results show that the plasma convection in the ionosphere is consistent with the anti-parallel merging model. When the IMF has a strongly positive By component under northward conditions, we find that the global plasma convection forms two cells oriented nearly along the Sun-earth line in the ionosphere. In the northern hemisphere, the dayside cell has clockwise convection mainly circulating within the polar cap on open field lines. A second cell with counterclockwise convection is located in the nightside circulating across the polar cap boundary, The observed two-cell convection pattern appears to be driven by the reconnection along the anti-parallel merging lines poleward of the cusp extending toward the dusk side when IMF By/Bz much greater than 1. The magnetic tension force on the newly reconnected field lines drives the plasma to move from dusk to dawn in the polar cusp region near the polar cap boundary. The field-aligned currents in the cusp region flow downward into the ionosphere. The return field-aligned currents extend into the polar cap in the center of the dayside convection cell. The field-aligned currents are closed through the Peterson currents in the ionosphere, which flow poleward from the polar cap boundary along the electric field direction.

Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): reference data for the trunk and application in patients with chronic postherpetic neuralgia.

PubMed

Pfau, Doreen B; Krumova, Elena K; Treede, Rolf-Detlef; Baron, Ralf; Toelle, Thomas; Birklein, Frank; Eich, Wolfgang; Geber, Christian; Gerhardt, Andreas; Weiss, Thomas; Magerl, Walter; Maier, Christoph

2014-05-01

Age- and gender-matched reference values are essential for the clinical use of quantitative sensory testing (QST). To extend the standard test sites for QST-according to the German Research Network on Neuropathic Pain-to the trunk, we collected QST profiles on the back in 162 healthy subjects. Sensory profiles for standard test sites were within normal interlaboratory differences. QST revealed lower sensitivity on the upper back than the hand, and higher sensitivity on the lower back than the foot, but no systematic differences between these trunk sites. Age effects were significant for most parameters. Females exhibited lower pressure pain thresholds (PPT) than males, which was the only significant gender difference. Values outside the 95% confidence interval of healthy subjects (considered abnormal) required temperature changes of >3.3-8.2 °C for thermal detection. For cold pain thresholds, confidence intervals extended mostly beyond safety cutoffs, hence only relative reference data (left-right differences, hand-trunk differences) were sufficiently sensitive. For mechanical detection and pain thresholds, left-right differences were 1.5-2.3 times more sensitive than absolute reference data. The most sensitive parameter was PPT, where already side-to-side differences >35% were abnormal. Compared to trunk reference data, patients with postherpetic neuralgia exhibited thermal and tactile deficits and dynamic mechanical allodynia, mostly without reduced mechanical pain thresholds. This pattern deviates from other types of neuropathic pain. QST reference data for the trunk will also be useful for patients with postthoracotomy pain or chronic back pain. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Effects of Teriparatide in Patients with Osteoporosis in Clinical Practice: 42-Month Results During and After Discontinuation of Treatment from the European Extended Forsteo® Observational Study (ExFOS).

PubMed

Napoli, Nicola; Langdahl, Bente L; Ljunggren, Östen; Lespessailles, Eric; Kapetanos, George; Kocjan, Tomaz; Nikolic, Tatjana; Eiken, Pia; Petto, Helmut; Moll, Thomas; Lindh, Erik; Marin, Fernando

2018-06-16

This study aimed to describe clinical outcomes in patients prescribed teriparatide and followed up for 18 months after stopping the drug in real-life conditions. The Extended Forsteo® Observational Study analysed incident clinical fractures in 6-month intervals using logistic regression with repeated measures. Changes in back pain (visual analogue scale) and health-related quality of life (HRQoL; EQ-5D questionnaire) were analysed using mixed models for repeated measures. Patients were analysed if they had a post-baseline visit, regardless of whether and for how long they took teriparatide. Of 1531 patients analysed (90.7% female, mean age: 70.3 years), 76 (5.0%) never took teriparatide. Median treatment duration was 23.6 months. The adjusted odds of clinical fracture decreased by 47% in the > 12- to 18-month treatment period (p = 0.013) compared with the first 6-month period, with no statistically significant reduction in the > 18- to 24-month interval. The clinical fracture rate remained stable during the 18 months' post-teriparatide, when approximately 98% of patients took osteoporosis medication (51% bisphosphonates). Clinical vertebral fractures were reduced at every time period compared with the first 6 months. Adjusted mean back pain scores decreased and EQ-5D scores increased significantly at each post-baseline observation. In a real-life clinical setting, the risk of clinical fractures declined during 24 months of teriparatide treatment. This reduction was maintained 18 months after stopping teriparatide. In parallel, patients reported significant improvements in back pain and HRQoL. The results should be interpreted in the context of the non-controlled design of this observational study.

Immediate Postsession Feeding Reduces Operant Responding in Rats

ERIC Educational Resources Information Center

Smethells, John R.; Fox, Andrew T.; Andrews, Jennifer J.; Reilly, Mark P.

2012-01-01

Three experiments investigated the effects of immediate and delayed postsession feeding on progressive-ratio and variable-interval schedule performance in rats. During Experiments 1 and 2, immediate postsession feeding decreased the breakpoint, or largest completed ratio, under progressive-ratio schedules. Experiment 3 was conducted to extend the…

A prospective study: current problems in radiotherapy for nasopharyngeal carcinoma in yogyakarta, indonesia.

PubMed

Stoker, Sharon D; Wildeman, Maarten A; Fles, Renske; Indrasari, Sagung R; Herdini, Camelia; Wildeman, Pieter L; van Diessen, Judi N A; Tjokronagoro, Maesadji; Tan, I Bing

2014-01-01

Nasopharyngeal carcinoma (NPC) has a high incidence in Indonesia. Previous study in Yogyakarta revealed a complete response of 29% and a median overall survival of less than 2 years. These poor treatment outcome are influenced by the long diagnose-to-treatment interval to radiotherapy (DTI) and the extended overall treatment time of radiotherapy (OTT). This study reveals insight why the OTT and DTI are prolonged. All patients treated with curative intent radiotherapy for NPC between July 2011 until October 2012 were included. During radiotherapy a daily diary was kept, containing information on DTI, missed radiotherapy days, the reason for missing and length of OTT. Sixty-eight patients were included. The median DTI was 106 days (95% CI: 98-170). Fifty-nine patients (87%) finished the treatment. The median OTT for radiotherapy was 57 days (95% CI: 57-65). The main reason for missing days was an inoperative radiotherapy machine (36%). Other reasons were patient's poor condition (21%), public holidays (14%), adjustment of the radiation field (7%), power blackout (3%), inoperative treatment planning system (2%) and patient related reasons (9%). Patient's insurance type was correlated to DTI in disadvantage for poor people. Yogyakarta has a lack of sufficient radiotherapy units which causes a delay of 3-4 months, besides the OTT is extended by 10-12 days. This influences treatment outcome to a great extend. The best solution would be creating sufficient radiotherapy units and better management in health care for poor patients. The growing economy in Indonesia will expectantly in time enable these solutions, but in the meantime solutions are needed. Solutions can consist of radiation outside office hours, better maintenance of the facilities and more effort from patient, doctor and nurse to finish treatment in time. These results are valuable when improving cancer care in low and middle income countries.

Magnetospheric State of Sawtooth Events

NASA Technical Reports Server (NTRS)

Fung, Shing F.; Tepper, Julia A.; Cai, Xia

2016-01-01

Magnetospheric sawtooth events, first identified in the early 1990s, are named for their characteristic appearance of multiple quasiperiodic intervals of slow decrease followed by sharp increase of proton differential energy fluxes in the geosynchronous region. The successive proton flux oscillations have been interpreted as recurrences of stretching and dipolarization of the nightside geomagnetic field. Due to their often extended intervals with 210 cycles, sawteeth occurrences are sometimes referred to as a magnetospheric mode. While studies of sawtooth events over the past two decades have yielded a wealth of information about such events, the magnetospheric state conditions for the occurrence of sawtooth events and how sawtooth oscillations may depend on the magnetospheric state conditions remain unclear. In this study, we investigate the characteristic magnetospheric state conditions (specified by Psw interplanetary magnetic field (IMF) Btot, IMF Bz Vsw, AE, Kp and Dst, all time shifted with respect to one another) associated with the intervals before, during, and after sawteeth occurrences. Applying a previously developed statistical technique, we have determined the most probable magnetospheric states propitious for the development and occurrence of sawtooth events, respectively. The statistically determined sawtooth magnetospheric state has also been validated by using out-of-sample events, confirming the notion that sawtooth intervals might represent a particular global state of the magnetosphere. We propose that the sawtooth state of the magnetosphere may be a state of marginal stability in which a slight enhancement in the loading rate of an otherwise continuous loading process can send the magnetosphere into the marginally unstable regime, causing it to shed limited amount of energy quickly and return to the marginally stable regime with the loading process continuing. Sawtooth oscillations result as the magnetosphere switches between the marginally stable (loading) and unstable (unloading) phases.

RELIABILITY CONCERNS IN THE REPEATED COMPUTERIZED ASSESSMENT OF ATTENTION IN CHILDREN

PubMed Central

Zabel, T. Andrew; von Thomsen, Christian; Cole, Carolyn; Martin, Rebecca; Mahone, E. Mark

2010-01-01

Assessment of attentional processes via computerized assessment is frequently used to quantify intra-individual cognitive improvement or decline in response to treatment. However, assessment of intra-individual change is highly dependent on sufficient test reliability. We examined the test–retest reliability of selected variables from one popular computerized continuous performance test (CPT)—i.e., the Conners’ CPT – Second Edition (CPT-II). Participants were 39 healthy children (20 girls) ages 6–18 without intellectual impairment (mean PPVT-III SS = 102.6), LD, or psychiatric disorders (DICA-IV). Test–retest reliability over the 3–8 month interval (mean = 6 months) was acceptable (Intraclass Correlations [ICC] = .82 to .92) on comparison measures (Beery Test of Visual Perception, WISC-IV Block Design, PPVT-III). In contrast, test–retest reliability was only modest for CPT-II raw scores (ICCs ranging from .62 to .82) and T-scores (ICCs ranging from .33 to .65) for variables of interest (Omissions, Commissions, Variability, Hit Reaction Time, and Attentiveness). Using test–retest reliability information published in the CPT-II manual, 90% confidence intervals based on reliable change index (RCI) methodology were constructed to examine the significance of test–retest difference/change scores. Of the participants in this sample of typically developing youth, 30% generated intra-individual changes in T-scores on the Omissions and Attentiveness variables that exceeded the 90% confidence intervals and qualified as “statistically rare” changes in score. These results suggest a considerable degree of normal variability in CPT-II test scores over extended test–retest intervals, and suggest a need for caution when interpreting test score changes in neurologically unstable clinical populations. PMID:19452302

In vivo evaluation of mutant selection window of cefquinome against Escherichia coli in piglet tissue-cage model.

PubMed

Zhang, Bingxu; Gu, Xiaoyan; Li, Yafei; Li, Xiaohong; Gu, Mengxiao; Zhang, Nan; Shen, Xiangguang; Ding, Huanzhong

2014-12-16

The resistance of cephalosporins is significantly serious in veterinary clinic. In order to inhibit the bacterial resistance production, the mutant selection window (MSW) hypothesis with Escherichia coli (E. coli) ATCC 25922 exposed to cefquinome in an animal tissue-cage model was investigated. Localized infection with E. coli was established in piglets, and the infected animals were administrated intramuscularly with various doses and intervals of cefquinome to provide antibiotic concentrations below the MIC99, between the MIC99 and the mutant prevention concentration (MPC), and above the MPC. E. coli lost susceptibility when drug concentrations fluctuated between the lower and upper boundaries of the window, which defined in vitro as the MIC99 (0.06 μg/mL) and the MPC (0.16 μg/mL) respectively. For PK/PD parameters, there were no mutant selection enrichment when T>MIC99 was ≤ 25% or T>MPC was ≥ 50% of administration interval. When T>MIC99 was > 25% and T>MPC was <50% of administration interval, resistance selection was observed. When AUC24 h/MIC99 and AUC24 h/MPC were considered, the mutant selection window extended from 32.84 h to 125.64 h and from 12.83 h to 49.09 h, respectively. These findings demonstrate that the MSW exists in vivo for time-dependent antimicrobial agents, and its boundaries fit well with those determined in vitro. Maintenance of antimicrobial concentrations above the MPC for > 50% of administration interval is a straightforward way to restrict the acquisition of resistance in this tissue cage model. This situation was achieved with daily intramuscular doses of 1 mg cefquinome/kg body weight.

Intact Interval Timing in Circadian CLOCK Mutants

PubMed Central

Cordes, Sara; Gallistel, C. R.

2008-01-01

While progress has been made in determining the molecular basis for the circadian clock, the mechanism by which mammalian brains time intervals measured in seconds to minutes remains a mystery. An obvious question is whether the interval timing mechanism shares molecular machinery with the circadian timing mechanism. In the current study, we trained circadian CLOCK +/− and −/− mutant male mice in a peak-interval procedure with 10 and 20-s criteria. The mutant mice were more active than their wild-type littermates, but there were no reliable deficits in the accuracy or precision of their timing as compared with wild-type littermates. This suggests that expression of the CLOCK protein is not necessary for normal interval timing. PMID:18602902

Working times of elastomeric impression materials determined by dimensional accuracy.

PubMed

Tan, E; Chai, J; Wozniak, W T

1996-01-01

The working times of five poly(vinyl siloxane) impression materials were estimated by evaluating the dimensional accuracy of stone dies of impressions of a standard model made at successive time intervals. The stainless steel standard model was represented by two abutments having known distances between landmarks in three dimensions. Three dimensions in the x-, y-, and z-axes of the stone dies were measured with a traveling microscope. A time interval was rejected as being within the working time if the percentage change of the resultant dies, in any dimension, was statistically different from those measured from stone dies from previous time intervals. The absolute dimensions of those dies from the rejected time interval also must have exceeded all those from previous time intervals. Results showed that the working times estimated with this method generally were about 30 seconds longer than those recommended by the manufacturers.

Sensitivity of diabetic retinopathy associated vision loss to screening interval in an agent-based/discrete event simulation model.

PubMed

Day, T Eugene; Ravi, Nathan; Xian, Hong; Brugh, Ann

2014-04-01

To examine the effect of changes to screening interval on the incidence of vision loss in a simulated cohort of Veterans with diabetic retinopathy (DR). This simulation allows us to examine potential interventions without putting patients at risk. Simulated randomized controlled trial. We develop a hybrid agent-based/discrete event simulation which incorporates a population of simulated Veterans--using abstracted data from a retrospective cohort of real-world diabetic Veterans--with a discrete event simulation (DES) eye clinic at which it seeks treatment for DR. We compare vision loss under varying screening policies, in a simulated population of 5000 Veterans over 50 independent ten-year simulation runs for each group. Diabetic Retinopathy associated vision loss increased as the screening interval was extended from one to five years (p<0.0001). This increase was concentrated in the third year of the screening interval (p<0.01). There was no increase in vision loss associated with increasing the screening interval from one year to two years (p=0.98). Increasing the screening interval for diabetic patients who have not yet developed diabetic retinopathy from 1 to 2 years appears safe, while increasing the interval to 3 years heightens risk for vision loss. Published by Elsevier Ltd.

Single-channel autocorrelation functions: the effects of time interval omission.

PubMed Central

Ball, F G; Sansom, M S

1988-01-01

We present a general mathematical framework for analyzing the dynamic aspects of single channel kinetics incorporating time interval omission. An algorithm for computing model autocorrelation functions, incorporating time interval omission, is described. We show, under quite general conditions, that the form of these autocorrelations is identical to that which would be obtained if time interval omission was absent. We also show, again under quite general conditions, that zero correlations are necessarily a consequence of the underlying gating mechanism and not an artefact of time interval omission. The theory is illustrated by a numerical study of an allosteric model for the gating mechanism of the locust muscle glutamate receptor-channel. PMID:2455553

Continuous Microfluidics (Ecology-on-a-Chip) Experiments for Long Term Observation of Bacteria at Liquid-Liquid Interfaces

NASA Astrophysics Data System (ADS)

Miranda, Michael; White, Andrew; Jalali, Maryam; Sheng, Jian

2017-11-01

A microfluidic bioassay incorporating a peristaltic pump and chemostat capable of continuously culturing a bacterial suspension through a microchannel for an extended period of time relevant to ecological processes is presented. A single crude oil droplet is dispensed on-chip and subsequently pinned to the top and bottom surfaces of the microchannel to establish a vertical curved oil-water interface to observe bacteria without boundary interference. The accumulation of extracellular polymeric substances (EPS), microbial film formation, and aggregation is provided by DIC microscopy with an EMCCD camera at an interval of 30 sec. Cell-interface interactions such as cell translational and angular motilities as well as encountering, attachment, detachment to the interface are obtained by a high speed camera at 1000 fps with a sampling interval of 10 min. Experiments on Pseudomonas sp. (P62) and isolated EPS suspensions from Sagitulla Stelleta and Roseobacter show rapid formation of bacterial aggregates including EPS streamers stretching tens of drop diameters long. These results provide crucial insights into environmentally relevant processes such as the initiation of marine oil snow, an alternative mode of biodegradation to conventional bioconsumption. Funded by GoMRI, NSF, ARO.

Multimodal gain control at the hippocampal Schaffer collateral-CA1 synapse.

PubMed

Lange-Asschenfeldt, Christian; Schipke, Carola G; Riepe, Matthias W

2007-04-06

Information processing at central nervous system synapses is shaped by long-lasting modifications, such as long-term potentiation and short-lived and putatively synapse-specific modifications by various forms of short-term plasticity, such as facilitation, potentiation, and depression. Using an extracellular paired-pulse facilitation (PPF) protocol at the Schaffer collateral-CA1 (SC) connection in acute hippocampal slices in mice, we extend previous reports of optimal signal gain at intermediate interpulse intervals obtained at single SC synapses to the network level. Moreover, maximum signal gain changed when the input intensity was altered. We found further that facilitation decreased with increasing stimulus amplitude and duration in an exact exponential fashion when varied at a fixed interpulse interval. Variation of these intensity parameters accounted for significant changes in PPF adding a spatial dimension to time-based synaptic filter characteristics. Thus, this synapse functions as an amplitude window discriminator with a low-level aperture in combination with a band-pass frequency filter. By providing mathematical functions for the characteristic presynaptic parameters frequency, stimulus amplitude, and pulse duration at the network level our results lay ground for future studies on pharmacologically, genetically, or otherwise altered animal models.

Decline in Cancer Screening in Vulnerable Populations? Results of the EDIFICE Surveys.

PubMed

Morère, Jean-François; Eisinger, François; Touboul, Chantal; Lhomel, Christine; Couraud, Sébastien; Viguier, Jérôme

2018-03-05

We studied cancer screening over time and social vulnerability via surveys of representative populations. Individuals aged 50-75 years with no personal history of cancer were questioned about lifetime participation in screening tests, compliance (adherence to recommended intervals [colorectal, breast and cervical cancer]) and opportunistic screening (prostate and lung cancer). The proportion of vulnerable/non-vulnerable individuals remained stable between 2011 and 2016. In 2011, social vulnerability had no impact on screening participation, nor on compliance. In 2014, however, vulnerability was correlated with less frequent uptake of colorectal screening (despite an organised programme) and prostate cancer screening (opportunistic), and also with reduced compliance with recommended intervals (breast and cervical cancer screening). In 2016, the trends observed in 2014 were substantiated and even extended to breast, colorectal and cervical cancer screening uptakes. Social vulnerability has an increasingly negative impact on cancer screening attendance. The phenomenon was identified in 2014 and had expanded by 2016. Although organised programmes have been shown to ensure equitable access to cancer screening, this remains a precarious achievement requiring regular monitoring. Further studies should focus on attitudes of vulnerable populations and on ways to improve cancer awareness campaigns.

Confidence intervals for the population mean tailored to small sample sizes, with applications to survey sampling.

PubMed

Rosenblum, Michael A; Laan, Mark J van der

2009-01-07

The validity of standard confidence intervals constructed in survey sampling is based on the central limit theorem. For small sample sizes, the central limit theorem may give a poor approximation, resulting in confidence intervals that are misleading. We discuss this issue and propose methods for constructing confidence intervals for the population mean tailored to small sample sizes. We present a simple approach for constructing confidence intervals for the population mean based on tail bounds for the sample mean that are correct for all sample sizes. Bernstein's inequality provides one such tail bound. The resulting confidence intervals have guaranteed coverage probability under much weaker assumptions than are required for standard methods. A drawback of this approach, as we show, is that these confidence intervals are often quite wide. In response to this, we present a method for constructing much narrower confidence intervals, which are better suited for practical applications, and that are still more robust than confidence intervals based on standard methods, when dealing with small sample sizes. We show how to extend our approaches to much more general estimation problems than estimating the sample mean. We describe how these methods can be used to obtain more reliable confidence intervals in survey sampling. As a concrete example, we construct confidence intervals using our methods for the number of violent deaths between March 2003 and July 2006 in Iraq, based on data from the study "Mortality after the 2003 invasion of Iraq: A cross sectional cluster sample survey," by Burnham et al. (2006).

A Coral-based Reconstruction of Sea Surface Salinity at Sabine Bank, Vanuatu from 2007 to 1843 CE

NASA Astrophysics Data System (ADS)

Gorman, M. K.; Quinn, T. M.; Taylor, F. W.; Dunn, E. M.; Cabioch, G.; Ballu, V.; Maes, C.; Austin, J. A.; Saustrup, S.; Pelletier, B.

2011-12-01

We present a reconstruction of sea surface salinity (SSS) derived from a coral δ18O time series extending from 2007-1843 CE at Sabine Bank, Vanuatu (SBV, 166.04° E, 15.94°S). This reconstruction is significant because instrumental records of SSS are rare in time and space, yet the SSS response to the El Niño Southern Oscillation (ENSO) forcing is large in many regions of the tropical oceans. There is a strong positive relationship between sea surface temperature anomalies (SSTA) in the central Pacific (Niño 3.4 region; canonical ENSO signal) and six month lagged sea surface salinity anomalies (SSSA, data from Delcroix et al., 2011) at SBV, which establishes a dynamical link between surface ocean variability at SBV and ENSO variability. We calculate a coral δ18O anomaly time series and note that there is a strong correlation between it and instrumental SSS variations over the period 1970-2007 (r = 0.70, p < 0.01). We compute a linear transfer function that we use to predict SSS variations given observed coral δ18O variations. A calibration-verification exercise conducted over two intervals (1970-1987, 1988-2007) resulted in similar correlations between instrumental and reconstructed SSS for both time periods, which provides confidence in our SSS reconstructions in the pre-1970 interval. We further test our SBV transfer function by applying it to a previously published coral δ18O record from Malo Channel, Vanuatu (Kilbourne et al., 2004b), located 130 km to the east of Sabine Bank. The reconstructed SSS time series from the two locations over their common time interval (1991-1939 CE) are nearly always the same within error, indicating that the ENSO-influenced salinity signal is regional in extent, and can be reconstructed using coral δ18O records from Vanuatu. We observe high salinity excursions (>0.5 psu) pre-1970 corresponding to strong ENSO warm phase events recorded in the SST instrumental record and historical ENSO record (i.e. 1941-42, 1918-19, 1877-78), and an overall freshening trend, demonstrating the ability of our reconstructed dataset to capture interannual variability as well as long-term trends in SSS at Vanuatu.

Bioequivalence and Safety of Twice-Daily Sustained-Release Paracetamol (Acetaminophen) Compared With 3- and 4-Times-Daily Paracetamol: A Repeat-Dose, Crossover Pharmacokinetic Study in Healthy Volunteers.

PubMed

Liu, Dongzhou J; Collaku, Agron

2018-01-01

Twice-daily sustained-release (SR) paracetamol (acetaminophen) offers convenient administration to chronic users. This study investigated at steady state (during the last 24 hours of a 3-day dosing period) the pharmacokinetics, bioequivalence, and safety of twice-daily SR paracetamol compared with extended-release (ER) and immediate-release (IR) paracetamol. In this open-label, randomized, multidose, 3-way crossover study, 28 healthy subjects received paracetamol SR (2 × 1000 mg twice daily), ER (2 × 665 mg 3 times daily), and IR (2 × 500 mg 4 times daily). At steady state, twice-daily SR paracetamol was bioequivalent to ER and IR paracetamol. The 90% confidence intervals for the ratios of geometric means were within the acceptance interval for SR/ER paracetamol (AUC 0-t , 0.973-1.033; AUC 0-24 , 0.974-1.034; AUC 0-∞ , 0.948-1.011; C max , 1.082-1.212; C av , 1.011-1.106) and SR/IR paracetamol (AUC 0-t , 0.969-1.029; AUC 0-24 , 0.968-1.027; AUC 0-∞ , 0.963-1.026; C max , 0.902-1.010; C av , 1.004-1.098). Given twice daily, the SR formulation demonstrated SR properties as expected. Mean time at or above a 4 μg/mL plasma concentration of paracetamol from 2 daily doses of the SR formulation was significantly longer than that from 4 daily doses of IR paracetamol. SR formulation also had a greater T max , a longer half-life, and lower C min compared with ER and IR paracetamol. All formulations were well tolerated. © 2017, The American College of Clinical Pharmacology.

Dominion. A game exploring information exploitation

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

Hobbs, Jacob Aaron

FlipIt is a game theoretic framework published in 2012[1] to investigate optimal strategies for managing security resources in response to Advanced Persistent Threats. It is a two-player game wherein a resource is controlled by exactly one player at any time. A player may move at any time to capture the resource, incurring a move cost, and is informed of the last time their opponent has moved only upon completing their move. Thus, moves may be wasted and takeover is considered \\stealthy", with regard to the other player. The game is played for an unlimited period of time, and the goalmore » of each player is to maximize the amount of time they are in control of the resource minus their total move cost, normalized by the current length of play. Marten Van Dijk and others[1] provided an analysis of various player strategies and proved optimal results for certain subclasses of players. We extend their work by providing a reformulation of the original game, wherein the optimal player strategies can be solved exactly, rather than only for certain subclasses. We call this reformulation Dominion, and place it within a broader framework of stealthy move games. We de ne Dominion to occur over a nite time scale (from 0 to 1), and give each player a certain number of moves to make within the time frame. Their expected score in this new scenario is the expected amount of time they have control, and the point of the game is to dominate as much of the unit interval as possible. We show how Dominion can be treated as a two player, simultaneous, constant sum, unit square game, where the gradient of the bene t curves for the players are linear and possibly discontinuous. We derive Nash equilibria for a basic version of Dominion, and then further explore the roles of information asymmetry in its variants. We extend these results to FlipIt and other cyber security applications.« less

Processing advantages for consonance: A comparison between rats (Rattus norvegicus) and humans (Homo sapiens).

PubMed

Crespo-Bojorque, Paola; Toro, Juan M

2016-05-01

Consonance is a salient perceptual feature in harmonic music associated with pleasantness. Besides being deeply rooted in how we experience music, research suggests consonant intervals are more easily processed than dissonant intervals. In the present work we explore from a comparative perspective if such processing advantage extends to more complex tasks such as the detection of abstract rules. We ran experiments on rule learning over consonant and dissonant intervals with nonhuman animals and human participants. Results show differences across species regarding the extent to which they benefit from differences in consonance. Animals learn abstract rules with the same ease independently of whether they are implemented over consonant intervals (Experiment 1), dissonant intervals (Experiment 2), or over a combination of them (Experiment 3). Humans, on the contrary, learn an abstract rule better when it is implemented over consonant (Experiment 4) than over dissonant intervals (Experiment 5). Moreover, their performance improves when there is a mapping between abstract categories defining a rule and consonant and dissonant intervals (Experiments 6 and 7). Results suggest that for humans, consonance might be used as a perceptual anchor for other cognitive processes as to facilitate the detection of abstract patterns. Lacking extensive experience with harmonic stimuli, nonhuman animals tested here do not seem to benefit from a processing advantage for consonant intervals. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Relapse prevention interventions for smoking cessation.

PubMed

Hajek, Peter; Stead, Lindsay F; West, Robert; Jarvis, Martin; Lancaster, Tim

2009-01-21

A number of treatments can help smokers make a successful quit attempt, but many initially successful quitters relapse over time. Several interventions were proposed to help prevent relapse. To assess whether specific interventions for relapse prevention reduce the proportion of recent quitters who return to smoking. We searched the Cochrane Tobacco Addiction Group trials register in August 2008 for studies mentioning relapse prevention or maintenance in title, abstracts or keywords. Randomized or quasi-randomized controlled trials of relapse prevention interventions with a minimum follow up of six months. We included smokers who quit on their own, or were undergoing enforced abstinence, or who were participating in treatment programmes. We included trials that compared relapse prevention interventions to a no intervention control, or that compared a cessation programme with additional relapse prevention components to a cessation programme alone. Studies were screened and data extracted by one author and checked by a second. Disagreements were resolved by discussion or referral to a third author. Fifty-four studies met inclusion criteria, but were heterogeneous in terms of populations and interventions. We considered 36 studies that randomized abstainers separately from studies that randomized participants prior to their quit date.Looking at studies of behavioural interventions which randomised abstainers, we detected no benefit of brief and 'skills-based' relapse prevention methods for women who had quit smoking due to pregnancy, or for smokers undergoing a period of enforced abstinence during hospitalisation or military training. We also failed to detect significant effects of behavioural interventions in trials in unselected groups of smokers who had quit on their own or with a formal programme. Amongst trials randomising smokers prior to their quit date and evaluating the effect of additional relapse prevention components we also found no evidence of benefit of behavioural interventions in any subgroup. Overall, providing training in skills thought to be needed for relapse avoidance did not reduce relapse, but most studies did not use experimental designs best suited to the task, and had limited power to detect expected small differences between interventions. For pharmacological interventions, extended treatment with varenicline significantly reduced relapse in one trial (risk ratio 1.18, 95% confidence interval 1.03 to 1.36). Pooling of five studies of extended treatment with bupropion failed to detect a significant effect (risk ratio 1.17; 95% confidence interval 0.99 to 1.39). Two small trials of oral nicotine replacement treatment (NRT) failed to detect an effect but treatment compliance was low and in two other trials of oral NRT randomizing short-term abstainers there was a significant effect of intervention. At the moment there is insufficient evidence to support the use of any specific behavioural intervention for helping smokers who have successfully quit for a short time to avoid relapse. The verdict is strongest for interventions focusing on identifying and resolving tempting situations, as most studies were concerned with these. There is little research available regarding other behavioural approaches. Extended treatment with varenicline may prevent relapse. Extended treatment with bupropion is unlikely to have a clinically important effect. Studies of extended treatment with nicotine replacement are needed.

Serial recall of colors: Two models of memory for serial order applied to continuous visual stimuli.

PubMed

Peteranderl, Sonja; Oberauer, Klaus

2018-01-01

This study investigated the effects of serial position and temporal distinctiveness on serial recall of simple visual stimuli. Participants observed lists of five colors presented at varying, unpredictably ordered interitem intervals, and their task was to reproduce the colors in their order of presentation by selecting colors on a continuous-response scale. To control for the possibility of verbal labeling, articulatory suppression was required in one of two experimental sessions. The predictions were derived through simulation from two computational models of serial recall: SIMPLE represents the class of temporal-distinctiveness models, whereas SOB-CS represents event-based models. According to temporal-distinctiveness models, items that are temporally isolated within a list are recalled more accurately than items that are temporally crowded. In contrast, event-based models assume that the time intervals between items do not affect recall performance per se, although free time following an item can improve memory for that item because of extended time for the encoding. The experimental and the simulated data were fit to an interference measurement model to measure the tendency to confuse items with other items nearby on the list-the locality constraint-in people as well as in the models. The continuous-reproduction performance showed a pronounced primacy effect with no recency, as well as some evidence for transpositions obeying the locality constraint. Though not entirely conclusive, this evidence favors event-based models over a role for temporal distinctiveness. There was also a strong detrimental effect of articulatory suppression, suggesting that verbal codes can be used to support serial-order memory of simple visual stimuli.

Overview of the potential and identified petroleum source rocks of the Appalachian basin, eastern United States: Chapter G.13 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

USGS Publications Warehouse

Coleman, James L.; Ryder, Robert T.; Milici, Robert C.; Brown, Stephen; Ruppert, Leslie F.; Ryder, Robert T.

2014-01-01

The Appalachian basin is the oldest and longest producing commercially viable petroleum-producing basin in the United States. Source rocks for reservoirs within the basin are located throughout the entire stratigraphic succession and extend geographically over much of the foreland basin and fold-and-thrust belt that make up the Appalachian basin. Major source rock intervals occur in Ordovician, Devonian, and Pennsylvanian strata with minor source rock intervals present in Cambrian, Silurian, and Mississippian strata.

ADHD symptoms and benefit from extended time testing accommodations.

PubMed

Lovett, Benjamin J; Leja, Ashley M

2015-02-01

To investigate the relationship between ADHD symptoms, executive functioning problems, and benefit from extended time testing accommodations. College students completed a battery of measures assessing processing speed and reading fluency, reading comprehension (under two different time limits), symptoms of ADHD, executive functioning deficits, and perceptions of need for extended time. Students reporting more symptoms of ADHD and executive functioning deficits actually benefited less from extended time, and students' perceptions of their timing needs did not predict benefit. Students with more ADHD symptoms are less likely to use extended time effectively, possibly because of their associated executive functioning problems. These results suggest there may be little justification for examining a student's ADHD symptoms when making extended time accommodation decisions. © 2013 SAGE Publications.

Winter nighttime ion temperatures and energetic electrons from OGO 6 plasma measurements

NASA Technical Reports Server (NTRS)

Sanatani, S.; Breig, E. L.

1981-01-01

In the reported investigation, ion temperature and suprathermal electron flux data were acquired with the retarding potential analyzer on board the OGO 6 satellite when it was in solar eclipse. Attention is given to measurements in the 400- to 800-km height interval between midnight and predawn in the northern winter nonpolar ionosphere. Statistical analysis of data recorded during a 1 month time span permits a decoupling of horizontal and altitude effects. A distinct longitudinal variation is observed for ion temperature above 500 km, with a significant relative enhancement over the western North Atlantic. Altitude distributions of ion temperature are compatible with Millstone Hill profiles within the common region of this enhancement. Large fluxes of energetic electrons are observed and extend to much lower geomagnetic latitudes in the same longitude sector.

An ISEE/Whistler model of equatorial electron density in the magnetosphere

NASA Technical Reports Server (NTRS)

Carpenter, D. L.; Anderson, R. R.

1992-01-01

Attention is given to an empirical model of equatorial electron density in the magnetosphere covering the L range 2.25-8. Although the model is primarily intended for application to the local time interval 00-15 MLT, a way to extend the model to the 15-24-MLT period is presented. The model describes, in piecewise fashion, the 'saturated' plasmasphere, the region of steep plasmapause gradients, and the plasma trough. Within the plasmasphere the model profile can be expressed as logne - Sigma-xi, where x1 = -0.3145L + 3.9043 is the principal or 'reference' term, and additional terms account for: a solar cycle variation with a peak at solar maximum; an annual variation with a December maximum; and a semiannual variation with equinoctial maxima.

Nonlinear estimation theory applied to the interplanetary orbit determination problem.

NASA Technical Reports Server (NTRS)

Tapley, B. D.; Choe, C. Y.

1972-01-01

Martingale theory and appropriate smoothing properties of Loeve (1953) have been used to develop a modified Gaussian second-order filter. The performance of the filter is evaluated through numerical simulation of a Jupiter flyby mission. The observations used in the simulation are on-board measurements of the angle between Jupiter and a fixed star taken at discrete time intervals. In the numerical study, the influence of each of the second-order terms is evaluated. Five filter algorithms are used in the simulations. Four of the filters are the modified Gaussian second-order filter and three approximations derived by neglecting one or more of the second-order terms in the equations. The fifth filter is the extended Kalman-Bucy filter which is obtained by neglecting all of the second-order terms.

BENTHIC AMPHIPOD COMMUNITY RESPONSE TO STRESS INDUCED BY ALGAL MATS IN A PACIFIC NORTHWEST ESTUARY

EPA Science Inventory

Amphipod, algal biomass and sediment samples were taken at two- to four-week intervals from June through December, 2000 along lines perpendicular to two transects in Yaquina Bay, OR, extending from within the Zostera marina bed at the river channel edge through intertidal burrowi...

AMPHIPOD COMMUNITY RESPONSE TO STRESS INDUCED BY ALGAL MATS IN A PACIFIC NORTHWEST ESTUARY

EPA Science Inventory

Amphipod, algal and sediment samples were taken at two- to four-week intervals from June through December, 2000 along two transects in Yaquina Bay, OR. The transects extended from within the Zostera marina bed at the river channel edge through intertidal burrowing shrimp ...

Similarities of Recently Acquired and Reactivated Memories in Interference

ERIC Educational Resources Information Center

Gordon, William C.

1977-01-01

Together, these studies replicate and extend Gordon and Spear's (1973a) findings that proactive interference decreases as the interval between prior and subsequent learning increases and that reactivation of a prior memory just before subsequent learning significantly increases the proactive interference due to the prior learning. (Author/RK)

Short-Term Forgetting without Interference

ERIC Educational Resources Information Center

McKeown, Denis; Mercer, Tom

2012-01-01

In the 1st reported experiment, we demonstrate that auditory memory is robust over extended retention intervals (RIs) when listeners compare the timbre of complex tones, even when active or verbal rehearsal is difficult or impossible. Thus, our tones have an abstract timbre that resists verbal labeling, they differ across trials so that no…

78 FR 25346 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-30

... from certain provisions of the Federal railroad safety regulations contained at 49 CFR Part 232, Brake System Safety Standards for Freight and Other Non-Passenger Trains and Equipment; End-of-Train Devices... five cycle trains and requests to extend the required mileage interval of the Class 1A brake tests of...

Computer Algebra Systems and Theorems on Real Roots of Polynomials

ERIC Educational Resources Information Center

Aidoo, Anthony Y.; Manthey, Joseph L.; Ward, Kim Y.

2010-01-01

A computer algebra system is used to derive a theorem on the existence of roots of a quadratic equation on any bounded real interval. This is extended to a cubic polynomial. We discuss how students could be led to derive and prove these theorems. (Contains 1 figure.)

A generic method for the evaluation of interval type-2 fuzzy linguistic summaries.

PubMed

Boran, Fatih Emre; Akay, Diyar

2014-09-01

Linguistic summarization has turned out to be an important knowledge discovery technique by providing the most relevant natural language-based sentences in a human consistent manner. While many studies on linguistic summarization have handled ordinary fuzzy sets [type-1 fuzzy set (T1FS)] for modeling words, only few of them have dealt with interval type-2 fuzzy sets (IT2FS) even though IT2FS is better capable of handling uncertainties associated with words. Furthermore, the existent studies work with the scalar cardinality based degree of truth which might lead to inconsistency in the evaluation of interval type-2 fuzzy (IT2F) linguistic summaries. In this paper, to overcome this shortcoming, we propose a novel probabilistic degree of truth for evaluating IT2F linguistic summaries in the forms of type-I and type-II quantified sentences. We also extend the properties that should be fulfilled by any degree of truth on linguistic summarization with T1FS to IT2F environment. We not only prove that our probabilistic degree of truth satisfies the given properties, but also illustrate by examples that it provides more consistent results when compared to the existing degree of truth in the literature. Furthermore, we carry out an application on linguistic summarization of time series data of Europe Brent Spot Price, along with a comparison of the results achieved with our approach and that of the existing degree of truth in the literature.

Effect of Extended 30 μg Ethinyl Estradiol with Continuous Low-Dose Ethinyl Estradiol and Cyclic 20 μg Ethinyl Estradiol Oral Contraception on Adolescent Bone Density: A Randomized Trial.

PubMed

Gersten, Janet; Hsieh, Jennifer; Weiss, Herman; Ricciotti, Nancy A

2016-12-01

To compare changes in lumbar spine bone mineral density after 12 months of a 91-day extended regimen or 28-day combined oral contraceptive with those in a healthy reference group not using hormonal contraceptives. Phase 2, multicenter, open-label, randomized, controlled study. Forty-five academic centers, clinical research centers, and community practices in the United States. Eight hundred twenty-nine postmenarcheal adolescent girls aged 12-18 years. Adolescents were randomly assigned to 91-day levonorgestrel (LNG)/ethinyl estradiol (EE) extended regimen (84 days of LNG 150 μg/EE 30 μg with 7 days of EE 10 μg [LNG/EE extended regimen]) or 28 days of LNG/EE (21 days of LNG 100 μg/EE 20 μg with 7 days of placebo [LNG/EE 21/7]) for 12 months. A reference group not seeking hormonal contraception was also evaluated. The primary end point was mean percent change in lumbar spine bone mineral density measured using dual-energy x-ray absorptiometry. Of 1361 adolescents randomized/enrolled, 829 were included in the primary analysis. Mean changes in lumbar spine bone mineral density were +2.26% with LNG/EE extended regimen, +1.45% with LNG/EE 21/7, and +2.50% in the reference group. Noninferiority of the LNG/EE extended regimen compared with the reference group was shown. A statistically significant treatment difference was found between LNG/EE 21/7 and the reference group (1.05%; 95% confidence interval, 0.61%-1.49%) but not between LNG/EE extended regimen and the reference group (0.23%; 95% confidence interval, -0.20% to 0.67%). No new safety signals were noted. Compared with the reference group, bone accrual was statistically significantly lower among LNG/EE 21/7 users but not among LNG/EE 30-μg extended regimen users. Additional research is needed to clarify the clinical relevance of these findings. Copyright © 2016 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

The Cretaceous - Paleogene paleogeography of Central Asia recorded in depositional environments of the Proto-Paratethys Sea in the Tarim Basin (Western China)

NASA Astrophysics Data System (ADS)

Yücel Kaya, Mustafa; Dupont-Nivet, Guillaume; Proust, Jean-Noel; Bougeois, Laurie; Meijer, Niels; Frieling, Joost; Fioroni, Chiara; Stoica, Marius; Roperch, Pierrick; Mamtimin, Mehmut; Aminov, Jovid

2017-04-01

The Proto-Paratethys, a shallow epicontinental sea, extended from Cretaceous to Paleogene times across Eurasia from the Mediterranean Tethys to the Tarim Basin in western China. Transgressive and regressive episodes of the Proto-Paratethys Sea have been previously recognized but their timing, extent and depositional environments remain poorly constrained especially for the Cretaceous and early Paleogene. This hampers understanding of their driving mechanisms (geodynamic and/or eustatic) and paleoclimatic consequences on regional aridification and monsoons. As part of the ERC "MAGIC" project, we report an integrated sedimentologic and stratigraphic analysis of the Proto-Paratethys from its initial Cretaceous onset to the final Paleogene retreat from multiple investigated sections in the western border of Tarim Basin. Facies associations include field observations and microfacies analyses from carbonate samples. New bio- and magneto-stratigraphic results from key intervals are also provided to testify the previously constructed regional stratigraphic framework. The previously controversial number of marine incursions in the Tarim Basin is resolved to 6 (3 Cretaceous and 3 Paleogene) also recognized in the neighboring Tajik and Turan Basins to the west and the present-day Alai Valley. The eastward extent of these marine incursions varied through time with a maximum extent during late Paleocene - early Eocene. The first marine incursion is a Cenomanian transgression recorded in the marls and calcareous mudstones of the Kukebai Formation. The next two are Coniacian and Campanian transgressions recognized in the carbonate units of the Yigeziya Formation. The first Paleogene incursion is characterized by thick evaporites of the Paleocene Aertashi Formation overlain by the marine shales of the Lower Qimugen Formation. The latter represents the maximum extent and the deepest environments of the Proto-Paratethys. The marine Kalatar limestones and silty shales of the Wulagen Formation are associated with the penultimate transgression whereas the silty shales of the Bashibulake Formation were laid down during the last smaller marine incursion. Generally, transgressive intervals are composed of restricted marine bay environments, shoal & oyster-rich bioherms giving rise to upper offshore to shoreface transition silty shales. The regressive intervals are composed of intertidal flats, supratidal sabkhas and salinas, fluvial, playa and lake environments of alluvial plain. The temporal and spatial extent of the transgressive and regressive intervals enable to discriminate the major drivers of marine fluctuations with their potential consequences on Asian aridification and monsoons.

Exponential Sum-Fitting of Dwell-Time Distributions without Specifying Starting Parameters

PubMed Central

Landowne, David; Yuan, Bin; Magleby, Karl L.

2013-01-01

Fitting dwell-time distributions with sums of exponentials is widely used to characterize histograms of open- and closed-interval durations recorded from single ion channels, as well as for other physical phenomena. However, it can be difficult to identify the contributing exponential components. Here we extend previous methods of exponential sum-fitting to present a maximum-likelihood approach that consistently detects all significant exponentials without the need for user-specified starting parameters. Instead of searching for exponentials, the fitting starts with a very large number of initial exponentials with logarithmically spaced time constants, so that none are missed. Maximum-likelihood fitting then determines the areas of all the initial exponentials keeping the time constants fixed. In an iterative manner, with refitting after each step, the analysis then removes exponentials with negligible area and combines closely spaced adjacent exponentials, until only those exponentials that make significant contributions to the dwell-time distribution remain. There is no limit on the number of significant exponentials and no starting parameters need be specified. We demonstrate fully automated detection for both experimental and simulated data, as well as for classical exponential-sum-fitting problems. PMID:23746510

Effects of Chicken Litter Storage Time and Ammonia Content on Thermal Resistance of Desiccation-Adapted Salmonella spp.

PubMed

Chen, Zhao; Wang, Hongye; Ionita, Claudia; Luo, Feng; Jiang, Xiuping

2015-10-01

Broiler chicken litter was kept as a stacked heap on a poultry farm, and samples were collected up to 9 months of storage. Chicken litter inoculated with desiccation-adapted Salmonella cells was heat-treated at 75, 80, 85, and 150°C. Salmonella populations decreased in all these samples during heat treatment, and the inactivation rates became lower in chicken litter when storage time was extended from 0 to 6 months. There was no significant difference (P > 0.05) in thermal resistance of Salmonella in 6- and 9-month litter samples, indicating that a threshold for thermal resistance was reached after 6 months. Overall, the thermal resistance of Salmonella in chicken litter was affected by the storage time of the litter. The changes in some chemical, physical, and microbiological properties during storage could possibly contribute to this difference. Moisture and ammonia could be two of the most significant factors influencing the thermal resistance of Salmonella cells in chicken litter. Our results emphasize the importance of adjusting time and temperature conditions for heat processing chicken litter when it is removed from the chicken house at different time intervals. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Effects of Chicken Litter Storage Time and Ammonia Content on Thermal Resistance of Desiccation-Adapted Salmonella spp.

PubMed Central

Chen, Zhao; Wang, Hongye; Ionita, Claudia; Luo, Feng

2015-01-01

Broiler chicken litter was kept as a stacked heap on a poultry farm, and samples were collected up to 9 months of storage. Chicken litter inoculated with desiccation-adapted Salmonella cells was heat-treated at 75, 80, 85, and 150°C. Salmonella populations decreased in all these samples during heat treatment, and the inactivation rates became lower in chicken litter when storage time was extended from 0 to 6 months. There was no significant difference (P > 0.05) in thermal resistance of Salmonella in 6- and 9-month litter samples, indicating that a threshold for thermal resistance was reached after 6 months. Overall, the thermal resistance of Salmonella in chicken litter was affected by the storage time of the litter. The changes in some chemical, physical, and microbiological properties during storage could possibly contribute to this difference. Moisture and ammonia could be two of the most significant factors influencing the thermal resistance of Salmonella cells in chicken litter. Our results emphasize the importance of adjusting time and temperature conditions for heat processing chicken litter when it is removed from the chicken house at different time intervals. PMID:26209673

Variations in rupture process with recurrence interval in a repeated small earthquake

USGS Publications Warehouse

Vidale, J.E.; Ellsworth, W.L.; Cole, A.; Marone, Chris

1994-01-01

In theory and in laboratory experiments, friction on sliding surfaces such as rock, glass and metal increases with time since the previous episode of slip. This time dependence is a central pillar of the friction laws widely used to model earthquake phenomena. On natural faults, other properties, such as rupture velocity, porosity and fluid pressure, may also vary with the recurrence interval. Eighteen repetitions of the same small earthquake, separated by intervals ranging from a few days to several years, allow us to test these laboratory predictions in situ. The events with the longest time since the previous earthquake tend to have about 15% larger seismic moment than those with the shortest intervals, although this trend is weak. In addition, the rupture durations of the events with the longest recurrence intervals are more than a factor of two shorter than for the events with the shortest intervals. Both decreased duration and increased friction are consistent with progressive fault healing during the time of stationary contact.In theory and in laboratory experiments, friction on sliding surfaces such as rock, glass and metal increases with time since the previous episode of slip. This time dependence is a central pillar of the friction laws widely used to model earthquake phenomena. On natural faults, other properties, such as rupture velocity, porosity and fluid pressure, may also vary with the recurrence interval. Eighteen repetitions of the same small earthquake, separated by intervals ranging from a few days to several years, allow us to test these laboratory predictions in situ. The events with the longest time since the previous earthquake tend to have about 15% larger seismic moment than those with the shortest intervals, although this trend is weak. In addition, the rupture durations of the events with the longest recurrence intervals are more than a factor of two shorter than for the events with the shortest intervals. Both decreased duration and increased friction are consistent with progressive fault healing during the time of stationary contact.

Buffered coscheduling for parallel programming and enhanced fault tolerance

DOEpatents

Petrini, Fabrizio [Los Alamos, NM; Feng, Wu-chun [Los Alamos, NM

2006-01-31

A computer implemented method schedules processor jobs on a network of parallel machine processors or distributed system processors. Control information communications generated by each process performed by each processor during a defined time interval is accumulated in buffers, where adjacent time intervals are separated by strobe intervals for a global exchange of control information. A global exchange of the control information communications at the end of each defined time interval is performed during an intervening strobe interval so that each processor is informed by all of the other processors of the number of incoming jobs to be received by each processor in a subsequent time interval. The buffered coscheduling method of this invention also enhances the fault tolerance of a network of parallel machine processors or distributed system processors

Recovery of Pavlovian sign-tracking (autoshaping) following the discontinuation of inter-trial interval food in rats.

PubMed

Kearns, David N; Weiss, Stanley J

2007-07-01

In pigeons, Pavlovian autoshaped keypecking produced by keylight-food pairings has been eliminated by introducing food during periods between CS presentations (i.e., during the inter-trial intervals). Keypecking eliminated in this manner reappears when the inter-trial USs are discontinued even though the CS is no longer paired with US. The present experiment investigated whether this recovery of responding produced by discontinuing unpaired inter-trial US presentations could be extended to another species, rats, within a Pavlovian sign-tracking paradigm. Rats were initially trained on a procedure where insertion of one retractable lever (CS(+)) was followed, response independently, with food, while insertion of another lever (CS(-)) was not paired with food. Rats quickly came to contact the CS(+) lever at high rates, but contacted the CS(-) lever infrequently. In the next phase, CS(+) was no longer followed by food. Explicitly unpaired food was presented only during the inter-trial intervals when both levers were absent. This treatment essentially eliminated the sign-tracking response. In the final phase, the unpaired inter-trial food presentations were discontinued while both CSs continued to be presented without food. This produced a significant recovery of the sign-tracking elicited by the CS(+) lever, extending the species generality of the Pavlovian resurgence phenomenon that has previously only been reported in pigeons, to rats.

Colonization of hydrogel lenses with Streptococcus pneumoniae: risk of development of corneal infiltrates.

PubMed

Sankaridurg, P R; Sharma, S; Willcox, M; Sweeney, D F; Naduvilath, T J; Holden, B A; Rao, G N

1999-05-01

To report the association between colonization of contact lenses with Streptococcus pneumoniae and the observation of corneal infiltrative events in a group of patients wearing disposable hydrogel lenses on an extended-wear schedule. In a prospective clinical trial, 330 patients wore disposable hydrogels on a 6-night extended-wear and replacement schedule. The contact lens, lid, and conjunctival microbiota of these subjects was analyzed at frequent intervals and at the time of an adverse event. Streptococcus pneumoniae was an uncommon isolate and was recovered from only one of the 3,763 conjunctival samples, five (0.1%) of the 3,764 lid samples, and 33 (0.8%) of the 4,315 contact lens samples. Of the 33 lens samples, 10 (30%) were associated with corneal infiltrative events. Many of the events were mild inflammatory responses and resolved rapidly on discontinuation of lens wear. The presence of S. pneumoniae on the contact lens was associated with a significant risk of development of corneal infiltrates (odds ratio, 3.0; p = 0.0227, logistic-regression analysis). Presence of S. pneumoniae on hydrogel lenses is a significant risk factor for the development of corneal infiltrates.

Shortening the incubation time for the combination disk diffusion extended-spectrum β-lactamase (ESBL) confirmation test: how far can we go?

PubMed

van den Bijllaardt, Wouter; Voermans, Patricia C M; Buiting, Anton G; Mouton, Johan W; Muller, Anouk E

2017-09-01

The combination disk diffusion extended-spectrum β-lactamase (ESBL) confirmation test (CDT) is used for the confirmation of ESBL production in Enterobacteriaceae and usually takes 16-20 h to results. In this study, we searched for the shortest possible incubation time without a reduction in reliability. A total of 125 ESBL screening-positive isolates were subjected to CDT and were molecularly characterised by microarray. Inhibition zones were read every hour over 6-18 h of incubation. Concordance between earlier and 18-h readings was calculated for each hour. Results were validated on 224 isolates during routine clinical practice. For the initial 125 isolates, concordance (Cohen's κ) between the 6-h and 18-h readings was 0.88 [95% confidence interval (CI) 0.78-0.96; P <0.001]. The earliest time point for full concordance with the 18-h reading was 10 h. Validation of the 10-h reading for 224 clinical isolates resulted in a concordance of 0.99 (95% CI 0.98-1.0) between the 10-h and 18-h readings. Overall concordance on all 349 isolates was 0.99 (95% CI 0.97-1.0). Reading after 10 h of incubation has an excellent correlation with results after 18 h of incubation. This can significantly reduce the turnaround time for ESBL detection in laboratories with long opening hours or providing a 24/7 service. Consequently, there is a potential for implementing infection control measures up to 8 h earlier. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Shorter intervals between great earthquakes near Sendai: Scour ponds and a sand layer attributable to A.D. 1454 overwash

NASA Astrophysics Data System (ADS)

Sawai, Yuki; Namegaya, Yuichi; Tamura, Toru; Nakashima, Rei; Tanigawa, Koichiro

2015-06-01

A sparsely documented tsunami in 1454 may subdivide the recurrence interval between the 869 and 2011 tsunamis near Sendai, as judged from geomorphic, stratigraphic, and archival evidence. Pond-filled breaches cut across beach ridges on century-old topographic maps. The basal pond deposit in one of these breaches postdates 1454. Stratigraphy on Sendai Plain includes a sand sheet that contains marine and brackish diatoms. Radiocarbon ages suggest that the sheet dates to 1406-1615 (2σ), and written records for this interval in Tohoku mention a tsunami in 1454. The inferred inundation extended 1.0-2.5 km inland from an approximate medieval shoreline. Simulated tsunamis that best account for the sand sheet require a thrust earthquake of moment magnitude 8.4 or larger. If the sand sheet represents the 1454 tsunami, the two most recent intervals between great thrust earthquakes in Sendai region spanned 585 and 557 years.

Eliminating livelock by assigning the same priority state to each message that is input into a flushable routing system during N time intervals

DOEpatents

Faber, V.

1994-11-29

Livelock-free message routing is provided in a network of interconnected nodes that is flushable in time T. An input message processor generates sequences of at least N time intervals, each of duration T. An input register provides for receiving and holding each input message, where the message is assigned a priority state p during an nth one of the N time intervals. At each of the network nodes a message processor reads the assigned priority state and awards priority to messages with priority state (p-1) during an nth time interval and to messages with priority state p during an (n+1) th time interval. The messages that are awarded priority are output on an output path toward the addressed output message processor. Thus, no message remains in the network for a time longer than T. 4 figures.

Eliminating livelock by assigning the same priority state to each message that is inputted into a flushable routing system during N time intervals

DOEpatents

Faber, Vance

1994-01-01

Livelock-free message routing is provided in a network of interconnected nodes that is flushable in time T. An input message processor generates sequences of at least N time intervals, each of duration T. An input register provides for receiving and holding each input message, where the message is assigned a priority state p during an nth one of the N time intervals. At each of the network nodes a message processor reads the assigned priority state and awards priority to messages with priority state (p-1) during an nth time interval and to messages with priority state p during an (n+1) th time interval. The messages that are awarded priority are output on an output path toward the addressed output message processor. Thus, no message remains in the network for a time longer than T.

a New Approach for Accuracy Improvement of Pulsed LIDAR Remote Sensing Data

NASA Astrophysics Data System (ADS)

Zhou, G.; Huang, W.; Zhou, X.; He, C.; Li, X.; Huang, Y.; Zhang, L.

2018-05-01

In remote sensing applications, the accuracy of time interval measurement is one of the most important parameters that affect the quality of pulsed lidar data. The traditional time interval measurement technique has the disadvantages of low measurement accuracy, complicated circuit structure and large error. A high-precision time interval data cannot be obtained in these traditional methods. In order to obtain higher quality of remote sensing cloud images based on the time interval measurement, a higher accuracy time interval measurement method is proposed. The method is based on charging the capacitance and sampling the change of capacitor voltage at the same time. Firstly, the approximate model of the capacitance voltage curve in the time of flight of pulse is fitted based on the sampled data. Then, the whole charging time is obtained with the fitting function. In this method, only a high-speed A/D sampler and capacitor are required in a single receiving channel, and the collected data is processed directly in the main control unit. The experimental results show that the proposed method can get error less than 3 ps. Compared with other methods, the proposed method improves the time interval accuracy by at least 20 %.

Digitization of Electrocardiogram From Telemetry Prior to In-hospital Cardiac Arrest: A Pilot Study.

PubMed

Attin, Mina; Wang, Lu; Soroushmehr, S M Reza; Lin, Chii-Dean; Lemus, Hector; Spadafore, Maxwell; Najarian, Kayvan

2016-03-01

Analyzing telemetry electrocardiogram (ECG) data over an extended period is often time-consuming because digital records are not widely available at hospitals. Investigating trends and patterns in the ECG data could lead to establishing predictors that would shorten response time to in-hospital cardiac arrest (I-HCA). This study was conducted to validate a novel method of digitizing paper ECG tracings from telemetry systems in order to facilitate the use of heart rate as a diagnostic feature prior to I-HCA. This multicenter study used telemetry to investigate full-disclosure ECG papers of 44 cardiovascular patients obtained within 1 hr of I-HCA with initial rhythms of pulseless electrical activity and asystole. Digital ECGs were available for seven of these patients. An algorithm to digitize the full-disclosure ECG papers was developed using the shortest path method. The heart rate was measured manually (averaging R-R intervals) for ECG papers and automatically for digitized and digital ECGs. Significant correlations were found between manual and automated measurements of digitized ECGs (p < .001) and between digitized and digital ECGs (p < .001). Bland-Altman methods showed bias = .001 s, SD = .0276 s, lower and upper 95% limits of agreement for digitized and digital ECGs = .055 and -.053 s, and percentage error = 0.22%. Root mean square (rms), percentage rms difference, and signal to noise ratio values were in acceptable ranges. The digitization method was validated. Digitized ECG provides an efficient and accurate way of measuring heart rate over an extended period of time. © The Author(s) 2015.

43 CFR 2.19 - When may the bureau extend the basic time limit?

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false When may the bureau extend the basic time... INFORMATION ACT; RECORDS AND TESTIMONY Timing of Responses to Requests § 2.19 When may the bureau extend the basic time limit? (a) The bureau may extend the basic time limit if unusual circumstances exist. Before...

Recurrence time statistics for finite size intervals

NASA Astrophysics Data System (ADS)

Altmann, Eduardo G.; da Silva, Elton C.; Caldas, Iberê L.

2004-12-01

We investigate the statistics of recurrences to finite size intervals for chaotic dynamical systems. We find that the typical distribution presents an exponential decay for almost all recurrence times except for a few short times affected by a kind of memory effect. We interpret this effect as being related to the unstable periodic orbits inside the interval. Although it is restricted to a few short times it changes the whole distribution of recurrences. We show that for systems with strong mixing properties the exponential decay converges to the Poissonian statistics when the width of the interval goes to zero. However, we alert that special attention to the size of the interval is required in order to guarantee that the short time memory effect is negligible when one is interested in numerically or experimentally calculated Poincaré recurrence time statistics.

Fast transfer of crossmodal time interval training.

PubMed

Chen, Lihan; Zhou, Xiaolin

2014-06-01

Sub-second time perception is essential for many important sensory and perceptual tasks including speech perception, motion perception, motor coordination, and crossmodal interaction. This study investigates to what extent the ability to discriminate sub-second time intervals acquired in one sensory modality can be transferred to another modality. To this end, we used perceptual classification of visual Ternus display (Ternus in Psychol Forsch 7:81-136, 1926) to implicitly measure participants' interval perception in pre- and posttests and implemented an intra- or crossmodal sub-second interval discrimination training protocol in between the tests. The Ternus display elicited either an "element motion" or a "group motion" percept, depending on the inter-stimulus interval between the two visual frames. The training protocol required participants to explicitly compare the interval length between a pair of visual, auditory, or tactile stimuli with a standard interval or to implicitly perceive the length of visual, auditory, or tactile intervals by completing a non-temporal task (discrimination of auditory pitch or tactile intensity). Results showed that after fast explicit training of interval discrimination (about 15 min), participants improved their ability to categorize the visual apparent motion in Ternus displays, although the training benefits were mild for visual timing training. However, the benefits were absent for implicit interval training protocols. This finding suggests that the timing ability in one modality can be rapidly acquired and used to improve timing-related performance in another modality and that there may exist a central clock for sub-second temporal processing, although modality-specific perceptual properties may constrain the functioning of this clock.

Training for long duration space missions

NASA Technical Reports Server (NTRS)

Goldberg, Joseph H.

1987-01-01

The successful completion of an extended duration manned mission to Mars will require renewed research effort in the areas of crew training and skill retention techniques. The current estimate of inflight transit time is about nine months each way, with a six month surface visit, an order of magnitude beyond previous U.S. space missions. Concerns arise when considering the level of skill retention required for highly critical, one time operations such as an emergency procedure or a Mars orbit injection. The factors responsible for the level of complex skill retention are reviewed, optimal ways of refreshing degraded skills are suggested, and a conceptual crew training design for a Mars mission is outlined. Currently proposed crew activities during a Mars mission were reviewed to identify the spectrum of skills which must be retained over a long time period. Skill retention literature was reviewed to identify those factors which must be considered in deciding when and which tasks need retraining. Task, training, and retention interval factors were identified. These factors were then interpreted in light of the current state of spaceflight and adaptive training systems.

Root niche separation can explain avoidance of seasonal drought stress and vulnerability of overstory trees to extended drought in a mature Amazonian forest

NASA Astrophysics Data System (ADS)

Ivanov, Valeriy Y.; Hutyra, Lucy R.; Wofsy, Steven C.; Munger, J. William; Saleska, Scott R.; de Oliveira, Raimundo C., Jr.; de Camargo, Plínio B.

2012-12-01

Large areas of Amazonian evergreen forest experience seasonal droughts extending for three or more months, yet show maximum rates of photosynthesis and evapotranspiration during dry intervals. This apparent resilience is belied by disproportionate mortality of the large trees in manipulations that reduce wet season rainfall, occurring after 2-3 years of treatment. The goal of this study is to characterize the mechanisms that produce these contrasting ecosystem responses. A mechanistic model is developed based on the ecohydrological framework of TIN (Triangulated Irregular Network)-based Real Time Integrated Basin Simulator + Vegetation Generator for Interactive Evolution (tRIBS+VEGGIE). The model is used to test the roles of deep roots and soil capillary flux to provide water to the forest during the dry season. Also examined is the importance of "root niche separation," in which roots of overstory trees extend to depth, where during the dry season they use water stored from wet season precipitation, while roots of understory trees are concentrated in shallow layers that access dry season precipitation directly. Observational data from the Tapajós National Forest, Brazil, were used as meteorological forcing and provided comprehensive observational constraints on the model. Results strongly suggest that deep roots with root niche separation adaptations explain both the observed resilience during seasonal drought and the vulnerability of canopy-dominant trees to extended deficits of wet season rainfall. These mechanisms appear to provide an adaptive strategy that enhances productivity of the largest trees in the face of their disproportionate heat loads and water demand in the dry season. A sensitivity analysis exploring how wet season rainfall affects the stability of the rainforest system is presented.

The high-frequency component of heart rate variability during extended wakefulness is closely associated with the depth of the ensuing sleep in C57BL6 mice.

PubMed

Kuo, T B J; Lai, C T; Chen, C Y; Yang, Y C; Yang, C C H

2016-08-25

This study aimed to test the hypothesis that, during extended wakefulness, parasympathetic activity is associated with the depth of the subsequent recovery sleep in mice. Fourteen male C57BL/6 mice were implanted with electrodes for sleep recording. Continuous spectral analysis was performed on the electroencephalogram (EEG) to obtain theta power (6-9Hz) and delta power (0-4Hz), as well as the R-R interval signals in order to quantify the high-frequency power (HF) and normalized low-frequency power (LF%) that are used to assess parasympathetic and sympathetic activity, respectively. All animals underwent a sleep deprivation experiment and a control experiment (6-h intervention and 1-h recovery period) on two separate days. During sleep deprivation, HF and theta power during wakefulness were significantly higher than during the control wakefulness after the second hour and first hour, respectively. During recovery non-rapid eye movement sleep, there was a rebound in sleep time and delta power as well as an elevation in HF relative to control post-intervention sleep. Both the rise in HF and theta power during extended wakefulness were found to be positively correlated with the delta power rebound. Furthermore, the HF change during extended wakefulness was also correlated with the amount of sleep loss and the enhancement of waking theta power. Our finding suggests that waking parasympathetic activity intimately reflects the cumulative sleep pressure, suggesting a potential role to be an autonomic marker for sleep propensity. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

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

Hadley, I.; Sinclair, C.I.K.; Magne, E.

This paper describes the life extension of a semi-submersible drilling rig built in the early 1970`s. A nominal design life of 20 years was estimated at the time of building; however, in the interim period, numerous improvements have been made in fatigue life estimation ad life improvement techniques, raising the possibility that a further 20 years of operation could be considered. The life extension strategy made use of a number of aspects of offshore technology which were not available at the time of construction of the rig. Finite element studies and results from offshore research programs were used to gaugemore » the effect of fatigue life improvement techniques. The program demonstrated the feasibility of extending the operation of the rig for a further 20 years, with the interval between in-service inspection increased to every five years. It also provided a valuable database of fracture toughness data for the rig materials, which may be used in future work to address reliability issues.« less

Extreme ionospheric ion energization and electron heating in Alfvén waves in the storm time inner magnetosphere

DOE PAGES

Chaston, C. C.; Bonnell, J. W.; Wygant, J. R.; ...

2015-12-06

Here we report measurements of energized outflowing/bouncing ionospheric ions and heated electrons in the inner magnetosphere during a geomagnetic storm. The ions arrive in the equatorial plane with pitch angles that increase with energy over a range from tens of eV to>50 keV while the electrons are field aligned up to ~1 keV. These particle distributions are observed during intervals of broadband low-frequency electromagnetic field fluctuations consistent with a Doppler-shifted spectrum of kinetic Alfvén waves and kinetic field line resonances. The fluctuations extend from L≈3 out to the apogee of the Van Allen Probes spacecraft at L ≈ 6.5. Theymore » thereby span most of the L shell range occupied by the ring current. Lastly, these measurements suggest a model for ionospheric ion outflow and energization driven by dispersive Alfvén waves that may account for the large storm time contribution of ionospheric ions to magnetospheric energy density.« less

Jeagle: a JAVA Runtime Verification Tool

NASA Technical Reports Server (NTRS)

DAmorim, Marcelo; Havelund, Klaus

2005-01-01

We introduce the temporal logic Jeagle and its supporting tool for runtime verification of Java programs. A monitor for an Jeagle formula checks if a finite trace of program events satisfies the formula. Jeagle is a programming oriented extension of the rule-based powerful Eagle logic that has been shown to be capable of defining and implementing a range of finite trace monitoring logics, including future and past time temporal logic, real-time and metric temporal logics, interval logics, forms of quantified temporal logics, and so on. Monitoring is achieved on a state-by-state basis avoiding any need to store the input trace. Jeagle extends Eagle with constructs for capturing parameterized program events such as method calls and method returns. Parameters can be the objects that methods are called upon, arguments to methods, and return values. Jeagle allows one to refer to these in formulas. The tool performs automated program instrumentation using AspectJ. We show the transformational semantics of Jeagle.

Data for first NASA Atmospheric Variability Experiment (AVE 1). Part 1: Data tabulation. [rawindsonde data for eastern United States

NASA Technical Reports Server (NTRS)

Scoggins, J. R.; Smith, O. E.

1973-01-01

A tablulation is given of rawinsonde data for NASA's first Atmospheric Variability Experiment (AVE 1) conducted during the period February 19-22, 1964. Methods of data handling and processing, and estimates of error magnitudes are also given. Data taken on the AVE 1 project in 1964 enabled an analysis of a large sector of the eastern United States on a fine resolution time scale. This experiment was run in February 1964, and data were collected as a wave developed in the East Gulf on a frontal system which extended through the eastern part of the United States. The primary objective of AVE 1 was to investigate the variability of parameters in space and over time intervals of three hours, and to integrate the results into NASA programs which require this type of information. The results presented are those from one approach, and represent only a portion of the total research effort that can be accomplished.

Causal Relationships Among Time Series of the Lange Bramke Catchment (Harz Mountains, Germany)

NASA Astrophysics Data System (ADS)

Aufgebauer, Britta; Hauhs, Michael; Bogner, Christina; Meesenburg, Henning; Lange, Holger

2016-04-01

Convergent Cross Mapping (CCM) has recently been introduced by Sugihara et al. for the identification and quantification of causal relationships among ecosystem variables. In particular, the method allows to decide on the direction of causality; in some cases, the causality might be bidirectional, indicating a network structure. We extend this approach by introducing a method of surrogate data to obtain confidence intervals for CCM results. We then apply this method to time series from stream water chemistry. Specifically, we analyze a set of eight dissolved major ions from three different catchments belonging to the hydrological monitoring system at the Bramke valley in the Harz Mountains, Germany. Our results demonstrate the potentials and limits of CCM as a monitoring instrument in forestry and hydrology or as a tool to identify processes in ecosystem research. While some networks of causally linked ions can be associated with simple physical and chemical processes, other results illustrate peculiarities of the three studied catchments, which are explained in the context of their special history.

Toward a continuous 405-kyr-calibrated Astronomical Time Scale for the Mesozoic Era

NASA Astrophysics Data System (ADS)

Hinnov, Linda; Ogg, James; Huang, Chunju

2010-05-01

Mesozoic cyclostratigraphy is being assembled into a continuous Astronomical Time Scale (ATS) tied to the Earth's cyclic orbital parameters. Recognition of a nearly ubiquitous, dominant ~400-kyr cycling in formations throughout the era has been particularly striking. Composite formations spanning contiguous intervals up to 50 myr clearly express these long-eccentricity cycles, and in some cases, this cycling is defined by third- or fourth-order sea-level sequences. This frequency is associated with the 405-kyr orbital eccentricity cycle, which provides a basic metronome and enables the extension of the well-defined Cenozoic ATS to scale the majority of the Mesozoic Era. This astronomical calibration has a resolution comparable to the 1% to 0.1% precision for radioisotope dating of Mesozoic ash beds, but with the added benefit of providing continuous stratigraphic coverage between dated beds. Extended portions of the Mesozoic ATS provide solutions to long-standing geologic problems of tectonics, eustasy, paleoclimate change, and rates of seafloor spreading.

Taming instabilities in power grid networks by decentralized control

NASA Astrophysics Data System (ADS)

Schäfer, B.; Grabow, C.; Auer, S.; Kurths, J.; Witthaut, D.; Timme, M.

2016-05-01

Renewables will soon dominate energy production in our electric power system. And yet, how to integrate renewable energy into the grid and the market is still a subject of major debate. Decentral Smart Grid Control (DSGC) was recently proposed as a robust and decentralized approach to balance supply and demand and to guarantee a grid operation that is both economically and dynamically feasible. Here, we analyze the impact of network topology by assessing the stability of essential network motifs using both linear stability analysis and basin volume for delay systems. Our results indicate that if frequency measurements are averaged over sufficiently large time intervals, DSGC enhances the stability of extended power grid systems. We further investigate whether DSGC supports centralized and/or decentralized power production and find it to be applicable to both. However, our results on cycle-like systems suggest that DSGC favors systems with decentralized production. Here, lower line capacities and lower averaging times are required compared to those with centralized production.

Gonadal morphogenesis and gene expression in reptiles with temperature-dependent sex determination.

PubMed

Merchant-Larios, H; Díaz-Hernández, V; Marmolejo-Valencia, A

2010-01-01

In reptiles with temperature-dependent sexual determination, the thermosensitive period (TSP) is the interval in which the sex is defined during gonadal morphogenesis. One-shift experiments in a group of eggs define the onset and the end of the TSP as all and none responses, respectively. Timing for sex-undetermined (UG) and -determined gonads (DG) differs at male- (MPT) or female-producing temperatures (FPT). During the TSP a decreasing number of embryos respond to temperature shifts indicating that in this period embryos with both UG and DG exist. Although most UG correspond to undifferentiated gonads, some embryos extend UG after the onset of histological differentiation. Thus, temperature affects gonadal cells during the process of morphogenesis, but timing of commitment depends on individual embryos. A correlation between gonadal morphogenesis, TSP, and gene expression suggests that determination of the molecular pathways modulated by temperature in epithelial cells (surface epithelium and medullary cords) holds the key for a unifying hypothesis on temperature-dependent sex determination. (c) 2010 S. Karger AG, Basel.

Real-Time Station Grouping under Dynamic Traffic for IEEE 802.11ah

PubMed Central

Tian, Le; Latré, Steven

2017-01-01

IEEE 802.11ah, marketed as Wi-Fi HaLow, extends Wi-Fi to the sub-1 GHz spectrum. Through a number of physical layer (PHY) and media access control (MAC) optimizations, it aims to bring greatly increased range, energy-efficiency, and scalability. This makes 802.11ah the perfect candidate for providing connectivity to Internet of Things (IoT) devices. One of these new features, referred to as the Restricted Access Window (RAW), focuses on improving scalability in highly dense deployments. RAW divides stations into groups and reduces contention and collisions by only allowing channel access to one group at a time. However, the standard does not dictate how to determine the optimal RAW grouping parameters. The optimal parameters depend on the current network conditions, and it has been shown that incorrect configuration severely impacts throughput, latency and energy efficiency. In this paper, we propose a traffic-adaptive RAW optimization algorithm (TAROA) to adapt the RAW parameters in real time based on the current traffic conditions, optimized for sensor networks in which each sensor transmits packets with a certain (predictable) frequency and may change the transmission frequency over time. The TAROA algorithm is executed at each target beacon transmission time (TBTT), and it first estimates the packet transmission interval of each station only based on packet transmission information obtained by access point (AP) during the last beacon interval. Then, TAROA determines the RAW parameters and assigns stations to RAW slots based on this estimated transmission frequency. The simulation results show that, compared to enhanced distributed channel access/distributed coordination function (EDCA/DCF), the TAROA algorithm can highly improve the performance of IEEE 802.11ah dense networks in terms of throughput, especially when hidden nodes exist, although it does not always achieve better latency performance. This paper contributes with a practical approach to optimizing RAW grouping under dynamic traffic in real time, which is a major leap towards applying RAW mechanism in real-life IoT networks. PMID:28677617

Real-Time Station Grouping under Dynamic Traffic for IEEE 802.11ah.

PubMed

Tian, Le; Khorov, Evgeny; Latré, Steven; Famaey, Jeroen

2017-07-04

IEEE 802.11ah, marketed as Wi-Fi HaLow, extends Wi-Fi to the sub-1 GHz spectrum. Through a number of physical layer (PHY) and media access control (MAC) optimizations, it aims to bring greatly increased range, energy-efficiency, and scalability. This makes 802.11ah the perfect candidate for providing connectivity to Internet of Things (IoT) devices. One of these new features, referred to as the Restricted Access Window (RAW), focuses on improving scalability in highly dense deployments. RAW divides stations into groups and reduces contention and collisions by only allowing channel access to one group at a time. However, the standard does not dictate how to determine the optimal RAW grouping parameters. The optimal parameters depend on the current network conditions, and it has been shown that incorrect configuration severely impacts throughput, latency and energy efficiency. In this paper, we propose a traffic-adaptive RAW optimization algorithm (TAROA) to adapt the RAW parameters in real time based on the current traffic conditions, optimized for sensor networks in which each sensor transmits packets with a certain (predictable) frequency and may change the transmission frequency over time. The TAROA algorithm is executed at each target beacon transmission time (TBTT), and it first estimates the packet transmission interval of each station only based on packet transmission information obtained by access point (AP) during the last beacon interval. Then, TAROA determines the RAW parameters and assigns stations to RAW slots based on this estimated transmission frequency. The simulation results show that, compared to enhanced distributed channel access/distributed coordination function (EDCA/DCF), the TAROA algorithm can highly improve the performance of IEEE 802.11ah dense networks in terms of throughput, especially when hidden nodes exist, although it does not always achieve better latency performance. This paper contributes with a practical approach to optimizing RAW grouping under dynamic traffic in real time, which is a major leap towards applying RAW mechanism in real-life IoT networks.

Place avoidance learning and memory in a jumping spider.

PubMed

Peckmezian, Tina; Taylor, Phillip W

2017-03-01

Using a conditioned passive place avoidance paradigm, we investigated the relative importance of three experimental parameters on learning and memory in a salticid, Servaea incana. Spiders encountered an aversive electric shock stimulus paired with one side of a two-sided arena. Our three parameters were the ecological relevance of the visual stimulus, the time interval between trials and the time interval before test. We paired electric shock with either a black or white visual stimulus, as prior studies in our laboratory have demonstrated that S. incana prefer dark 'safe' regions to light ones. We additionally evaluated the influence of two temporal features (time interval between trials and time interval before test) on learning and memory. Spiders exposed to the shock stimulus learned to associate shock with the visual background cue, but the extent to which they did so was dependent on which visual stimulus was present and the time interval between trials. Spiders trained with a long interval between trials (24 h) maintained performance throughout training, whereas spiders trained with a short interval (10 min) maintained performance only when the safe side was black. When the safe side was white, performance worsened steadily over time. There was no difference between spiders tested after a short (10 min) or long (24 h) interval before test. These results suggest that the ecological relevance of the stimuli used and the duration of the interval between trials can influence learning and memory in jumping spiders.

Estimation of postmortem interval based on colony development time for Anoplolepsis longipes (Hymenoptera: Formicidae).

PubMed

Goff, M L; Win, B H

1997-11-01

The postmortem interval for a set of human remains discovered inside a metal tool box was estimated using the development time required for a stratiomyid fly (Diptera: Stratiomyidae), Hermetia illucens, in combination with the time required to establish a colony of the ant Anoplolepsis longipes (Hymenoptera: Formicidae) capable of producing alate (winged) reproductives. This analysis resulted in a postmortem interval estimate of 14 + months, with a period of 14-18 months being the most probable time interval. The victim had been missing for approximately 18 months.

TIME-INTERVAL MEASURING DEVICE

DOEpatents

Gross, J.E.

1958-04-15

An electronic device for measuring the time interval between two control pulses is presented. The device incorporates part of a previous approach for time measurement, in that pulses from a constant-frequency oscillator are counted during the interval between the control pulses. To reduce the possible error in counting caused by the operation of the counter gating circuit at various points in the pulse cycle, the described device provides means for successively delaying the pulses for a fraction of the pulse period so that a final delay of one period is obtained and means for counting the pulses before and after each stage of delay during the time interval whereby a plurality of totals is obtained which may be averaged and multplied by the pulse period to obtain an accurate time- Interval measurement.

Monitoring molecular interactions using photon arrival-time interval distribution analysis

DOEpatents

Laurence, Ted A [Livermore, CA; Weiss, Shimon [Los Angels, CA

2009-10-06

A method for analyzing/monitoring the properties of species that are labeled with fluorophores. A detector is used to detect photons emitted from species that are labeled with one or more fluorophores and located in a confocal detection volume. The arrival time of each of the photons is determined. The interval of time between various photon pairs is then determined to provide photon pair intervals. The number of photons that have arrival times within the photon pair intervals is also determined. The photon pair intervals are then used in combination with the corresponding counts of intervening photons to analyze properties and interactions of the molecules including brightness, concentration, coincidence and transit time. The method can be used for analyzing single photon streams and multiple photon streams.

[Estimation of the atrioventricular time interval by pulse Doppler in the normal fetal heart].

PubMed

Hamela-Olkowska, Anita; Dangel, Joanna

2009-08-01

To assess normative values of the fetal atrioventricular (AV) time interval by pulse-wave Doppler methods on 5-chamber view. Fetal echocardiography exams were performed using Acuson Sequoia 512 in 140 singleton fetuses at 18 to 40 weeks of gestation with sinus rhythm and normal cardiac and extracardiac anatomy. Pulsed Doppler derived AV intervals were measured from left ventricular inflow/outflow view using transabdominal convex 3.5-6 MHz probe. The values of AV time interval ranged from 100 to 150 ms (mean 123 +/- 11.2). The AV interval was negatively correlated with the heart rhythm (p<0.001). Fetal heart rate decreased as gestation progressed (p<0.001). Thus, the AV intervals increased with the age of gestation (p=0.007). However, in the same subgroup of the fetal heart rate there was no relation between AV intervals and gestational age. Therefore, the AV intervals showed only the heart rate dependence. The 95th percentiles of AV intervals according to FHR ranged from 135 to 148 ms. 1. The AV interval duration was negatively correlated with the heart rhythm. 2. Measurement of AV time interval is easy to perform and has a good reproducibility. It may be used for the fetal heart block screening in anti-Ro and anti-La positive pregnancies. 3. Normative values established in the study may help obstetricians in assessing fetal abnormalities of the AV conduction.

Low rates of loco-regional recurrence following extended lymph node dissection for gastric cancer.

PubMed

Muratore, A; Zimmitti, G; Lo Tesoriere, R; Mellano, A; Massucco, P; Capussotti, L

2009-06-01

The study by MacDonald et al. [Chemoradiotherapy after surgery compared with surgery alone for adenocarcinoma of the stomach or gastroesophageal junction. N Engl J Med 2001;345:725-30] has reported low loco-regional recurrence rates (19%) after gastric cancer resection and adjuvant radiotherapy. However, the lymph node dissection was often "inadequate". The aim of this retrospective study is to analyse if an extended lymph node dissection (D2) without adjuvant radiotherapy may achieve comparable loco-regional recurrence rates. A prospective database of 200 patients who underwent a curative resection for gastric carcinoma from January 2000 to December 2006 was analysed. D2 lymph node dissection was standard. Recurrences were categorized as loco-regional, peritoneal, or distant. No patients received neoadjuvant or adjuvant radiotherapy. The in-hospital mortality rate was 1% (2 patients). The mean number of dissected lymph nodes was 25.9. Overall and disease-free survival at 5years were 60.7% and 61.2% respectively. During the follow-up, 60 patients (30%) have recurred at 76 sites: 38 (50%) distant metastases, 25 (32.9%) peritoneal metastases, and 13 (17.1%) loco-regional recurrences. The loco-regional recurrence was isolated in 6 patients and associated with peritoneal or distant metastases in 7 patients. The mean time to the first recurrence was 18.9 (95% confidence interval: 15.0-21.9) months. Extended lymph node dissection is safe and warrants low loco-regional recurrence rates.

Bayesian analyses of time-interval data for environmental radiation monitoring.

PubMed

Luo, Peng; Sharp, Julia L; DeVol, Timothy A

2013-01-01

Time-interval (time difference between two consecutive pulses) analysis based on the principles of Bayesian inference was investigated for online radiation monitoring. Using experimental and simulated data, Bayesian analysis of time-interval data [Bayesian (ti)] was compared with Bayesian and a conventional frequentist analysis of counts in a fixed count time [Bayesian (cnt) and single interval test (SIT), respectively]. The performances of the three methods were compared in terms of average run length (ARL) and detection probability for several simulated detection scenarios. Experimental data were acquired with a DGF-4C system in list mode. Simulated data were obtained using Monte Carlo techniques to obtain a random sampling of the Poisson distribution. All statistical algorithms were developed using the R Project for statistical computing. Bayesian analysis of time-interval information provided a similar detection probability as Bayesian analysis of count information, but the authors were able to make a decision with fewer pulses at relatively higher radiation levels. In addition, for the cases with very short presence of the source (< count time), time-interval information is more sensitive to detect a change than count information since the source data is averaged by the background data over the entire count time. The relationships of the source time, change points, and modifications to the Bayesian approach for increasing detection probability are presented.

21 CFR 99.203 - Request to extend the time for completing planned studies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Request to extend the time for completing planned... DEVICES Manufacturer's Submissions, Requests, and Applications § 99.203 Request to extend the time for... FDA under § 99.201, that FDA extend the 36-month time period for completing the studies and submitting...

21 CFR 99.203 - Request to extend the time for completing planned studies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Request to extend the time for completing planned... DEVICES Manufacturer's Submissions, Requests, and Applications § 99.203 Request to extend the time for... FDA under § 99.201, that FDA extend the 36-month time period for completing the studies and submitting...

22 CFR 401.19 - Reducing or extending time and dispensing with statements.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Reducing or extending time and dispensing with... RULES OF PROCEDURE Applications § 401.19 Reducing or extending time and dispensing with statements. In... Commission may reduce or extend the time for the presentation of any paper or the doing of any act required...

21 CFR 99.203 - Request to extend the time for completing planned studies.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Request to extend the time for completing planned... DEVICES Manufacturer's Submissions, Requests, and Applications § 99.203 Request to extend the time for... FDA under § 99.201, that FDA extend the 36-month time period for completing the studies and submitting...

Previous Antibiotic Exposure Increases Risk of Infection with Extended-Spectrum-β-Lactamase- and AmpC-Producing Escherichia coli and Klebsiella pneumoniae in Pediatric Patients

PubMed Central

Miles-Jay, Arianna; Kronman, Matthew P.; Zhou, Chuan; Adler, Amanda L.; Haaland, Wren; Weissman, Scott J.; Elward, Alexis; Newland, Jason G.; Zaoutis, Theoklis; Qin, Xuan

2016-01-01

The objective of this study was to determine whether antibiotic exposure is associated with extended-spectrum-beta-lactamase- or AmpC-producing Escherichia coli or Klebsiella pneumoniae infections in children. We collected extended-spectrum-beta-lactamase- or AmpC-producing E. coli or K. pneumoniae isolates and same-species susceptible controls from normally sterile sites of patients aged ≤21 years, along with associated clinical data, at four free-standing pediatric centers. After controlling for potential confounders, the relative risk of having an extended-spectrum-beta-lactamase-producing isolate rather than a susceptible isolate was 2.2 times higher (95% confidence interval [CI], 1.49 to 3.35) among those with antibiotic exposure in the 30 days prior to infection than in those with no antibiotic exposure. The results were similar when analyses were limited to exposure to third-generation cephalosporins, other broad-spectrum beta-lactams, or trimethoprim-sulfamethoxazole. Conversely, the relative risk of having an AmpC-producing versus a susceptible isolate was not significantly elevated with any antibiotic exposure in the 30 days prior to infection (adjusted relative risk ratio, 1.12; 95% CI, 0.65 to 1.91). However, when examining subgroups of antibiotics, the relative risk of having an AmpC-producing isolate was higher for patients with exposure to third-generation cephalosporins (adjusted relative risk ratio, 4.48; 95% CI, 1.75 to 11.43). Dose-response relationships between antibiotic exposure and extended-spectrum-beta-lactamase-producing or AmpC-producing isolates were not demonstrated. These results reinforce the need to study and implement pediatric antimicrobial stewardship strategies, and they indicate that epidemiological studies of third-generation cephalosporin-resistant E. coli and K. pneumoniae isolates should include resistance mechanisms when possible. PMID:27139486

The Time Is Up: Compression of Visual Time Interval Estimations of Bimodal Aperiodic Patterns

PubMed Central

Duarte, Fabiola; Lemus, Luis

2017-01-01

The ability to estimate time intervals subserves many of our behaviors and perceptual experiences. However, it is not clear how aperiodic (AP) stimuli affect our perception of time intervals across sensory modalities. To address this question, we evaluated the human capacity to discriminate between two acoustic (A), visual (V) or audiovisual (AV) time intervals of trains of scattered pulses. We first measured the periodicity of those stimuli and then sought for correlations with the accuracy and reaction times (RTs) of the subjects. We found that, for all time intervals tested in our experiment, the visual system consistently perceived AP stimuli as being shorter than the periodic (P) ones. In contrast, such a compression phenomenon was not apparent during auditory trials. Our conclusions are: first, the subjects exposed to P stimuli are more likely to measure their durations accurately. Second, perceptual time compression occurs for AP visual stimuli. Lastly, AV discriminations are determined by A dominance rather than by AV enhancement. PMID:28848406

Treatment decisions and the impact of adverse events before and during extended endocrine therapy in postmenopausal early breast cancer.

PubMed

Blok, Erik J; Kroep, Judith R; Meershoek-Klein Kranenbarg, Elma; Duijm-de Carpentier, Marjolijn; Putter, Hein; Liefers, Gerrit-Jan; Nortier, Johan W R; Rutgers, Emiel J Th; Seynaeve, Caroline M; van de Velde, Cornelis J H

2018-05-01

Extended endocrine therapy beyond 5 years for postmenopausal breast cancer has been studied within multiple phase III trials. Treatment compliance in these trials is generally poor. In this analysis, we aimed to determine factors that were associated with participation in the phase III Investigation on the Duration of Extended Adjuvant Letrozole (IDEAL) trial and with early treatment discontinuation, and how this influenced survival outcome. In the IDEAL trial, postmenopausal patients were randomised between 2.5 or 5 years of extended letrozole, after completing 5 years of endocrine therapy for hormone receptor-positive early breast cancer. A subgroup of this population participated earlier in the Tamoxifen Exemestane Adjuvant Multinational trial (5 years of exemestane or 2.5 years of tamoxifen followed by exemestane as primary adjuvant therapy) in which we explored which factors were determinative for enrolment in the IDEAL study. In the IDEAL cohort, we evaluated which factors predicted for early treatment discontinuation and the effect of early treatment discontinuation on disease-free survival (DFS). Nodal status, younger age and adjuvant chemotherapy were significantly associated with higher enrolment in the IDEAL trial. In the IDEAL cohort, adverse events (AEs), the type of primary endocrine therapy and the interval between primary and extended therapy were associated with early treatment discontinuation. Among the reported AEs, depressive feelings (56%) were most frequently associated with early treatment discontinuation. Early treatment discontinuation was not associated with worse DFS (hazard ratio [HR] = 1.02, 95% confidence interval = 0.76-1.37). In this analysis, we found that risk factors were most strongly associated enrolment in the IDEAL trial. In contrast, patient experiences were the most significant factors leading to early treatment discontinuation, with no effect on DFS. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chromium release from new stainless steel, recycled and nickel-free orthodontic brackets.

PubMed

Sfondrini, Maria Francesca; Cacciafesta, Vittorio; Maffia, Elena; Massironi, Sarah; Scribante, Andrea; Alberti, Giancarla; Biesuz, Raffaela; Klersy, Catherine

2009-03-01

To test the hypothesis that there is no difference in the amounts of chromium released from new stainless steel brackets, recycled stainless steel brackets, and nickel-free (Ni-free) orthodontic brackets. This in vitro study was performed using a classic batch procedure by immersion of the samples in artificial saliva at various acidities (pH 4.2, 6.5, and 7.6) over an extended time interval (t(1) = 0.25 h, t(2) = 1 h, t(3) = 24 h, t(4) = 48 h, t(5) = 120 h). The amount of chromium release was determined using an atomic absorption spectrophotometer and an inductively coupled plasma atomic emission spectrometer. Statistical analysis included a linear regression model for repeated measures, with calculation of Huber-White robust standard errors to account for intrabracket correlation of data. For post hoc comparisons the Bonferroni correction was applied. The greatest amount of chromium was released from new stainless steel brackets (0.52 +/- 1.083 microg/g), whereas the recycled brackets released 0.27 +/- 0.38 microg/g. The smallest release was measured with Ni-free brackets (0.21 +/- 0.51 microg/g). The difference between recycled brackets and Ni-free brackets was not statistically significant (P = .13). For all brackets, the greatest release (P = .000) was measured at pH 4.2, and a significant increase was reported between all time intervals (P < .002). The hypothesis is rejected, but the amount of chromium released in all test solutions was well below the daily dietary intake level.

Understanding phonological memory deficits in boys with attention-deficit/hyperactivity disorder (ADHD): dissociation of short-term storage and articulatory rehearsal processes.

PubMed

Bolden, Jennifer; Rapport, Mark D; Raiker, Joseph S; Sarver, Dustin E; Kofler, Michael J

2012-08-01

The current study dissociated and examined the two primary components of the phonological working memory subsystem--the short-term store and articulatory rehearsal mechanism--in boys with ADHD (n = 18) relative to typically developing boys (n = 15). Word lists of increasing length (2, 4, and 6 words per trial) were presented to and recalled by children following a brief (3 s) interval to assess their phonological short-term storage capacity. Children's ability to utilize the articulatory rehearsal mechanism to actively maintain information in the phonological short-term store was assessed using word lists at their established memory span but with extended rehearsal times (12 s and 21 s delays). Results indicate that both phonological shortterm storage capacity and articulatory rehearsal are impaired or underdeveloped to a significant extent in boys with ADHD relative to typically developing boys, even after controlling for age, SES, IQ, and reading speed. Larger magnitude deficits, however, were apparent in short-term storage capacity (ES = 1.15 to 1.98) relative to articulatory rehearsal (ES = 0.47 to 1.02). These findings are consistent with previous reports of deficient phonological short-term memory in boys with ADHD, and suggest that future attempts to develop remedial cognitive interventions for children with ADHD will need to include active components that require children to hold increasingly more information over longer time intervals.

Achilles' ear? Inferior human short-term and recognition memory in the auditory modality.

PubMed

Bigelow, James; Poremba, Amy

2014-01-01

Studies of the memory capabilities of nonhuman primates have consistently revealed a relative weakness for auditory compared to visual or tactile stimuli: extensive training is required to learn auditory memory tasks, and subjects are only capable of retaining acoustic information for a brief period of time. Whether a parallel deficit exists in human auditory memory remains an outstanding question. In the current study, a short-term memory paradigm was used to test human subjects' retention of simple auditory, visual, and tactile stimuli that were carefully equated in terms of discriminability, stimulus exposure time, and temporal dynamics. Mean accuracy did not differ significantly among sensory modalities at very short retention intervals (1-4 s). However, at longer retention intervals (8-32 s), accuracy for auditory stimuli fell substantially below that observed for visual and tactile stimuli. In the interest of extending the ecological validity of these findings, a second experiment tested recognition memory for complex, naturalistic stimuli that would likely be encountered in everyday life. Subjects were able to identify all stimuli when retention was not required, however, recognition accuracy following a delay period was again inferior for auditory compared to visual and tactile stimuli. Thus, the outcomes of both experiments provide a human parallel to the pattern of results observed in nonhuman primates. The results are interpreted in light of neuropsychological data from nonhuman primates, which suggest a difference in the degree to which auditory, visual, and tactile memory are mediated by the perirhinal and entorhinal cortices.

78 FR 51123 - Airworthiness Directives; Bell Helicopter Textron

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-20

... (TIS) or 10 years, whichever comes first. The proposed actions are intended to detect pitting or... delay. We may change this proposal in light of the comments we receive. Discussion On November 24, 2010... extends the overhaul interval of the servo actuator to 10,000 hours TIS or 10 years, whichever comes first...

Onset of Dyskinesia and Changes in Postural Task Performance during the Course of Neuroleptic Withdrawal.

ERIC Educational Resources Information Center

Newell, Karl M.; Ko, Young G.; Sprague, Robert L.; Mahorney, Steven L.; Bodfish, James W.

2002-01-01

The effect of neuroleptic withdrawal on postural task performance of 20 adults with mental retardation was examined. Assessments were conducted at baseline and monthly intervals, extending to one year following complete medication withdrawal, when significant changes in amount of postural motion and sequential pattern of postural movement…

Alternative Fuels Data Center: Natural Gas Vehicle Maintenance and Safety

Science.gov Websites

and delivery systems for road vehicles. Oil-Change Intervals Cleaner-burning fuels have a direct impact on extending the useful life of the engine's lubricating oil. In conventionally fueled vehicles , engine oil degrades as a result of soot and other impurities from the combustion process that get

Construction of a series of congenic mice with recombinant chromosome 1 regions surrounding the genetic loci for resistance to intracellular parasites (Ity, Lsh, and Bcg), DNA repair responses (Rep-1), and the cytoskeletal protein villin (Vil).

PubMed

Mock, B A; Holiday, D L; Cerretti, D P; Darnell, S C; O'Brien, A D; Potter, M

1994-01-01

The interval of mouse chromosome 1 extending from Idh-1 to Pep-3 harbors the natural resistance gene Ity/Lsh/Bcg; it controls the outcome of infection with Salmonella typhimurium, Leishmania donovani, and several Mycobacterium species. This region also contains a DNA repair gene, Rep-1, which determines the rapidity with which double-strand breaks in chromatin are repaired. BALB/cAnPt and DBA/2N mice differ in their phenotypic expression of these genes. To generate appropriate strains of mice for the study of these genes, a series of 10 C.D2 congenic strains recombinant across a 28-centimorgan interval of mouse chromosome 1 extending from Idh-1 to Pep-3 were derived from crosses of the C.D2-Idh-1 Pep-3 congenic strain back to BALB/cAn. Analyses of these recombinant strains will allow the correlation of biological-immunological phenotypes with defined genetic regions.

Construction of a series of congenic mice with recombinant chromosome 1 regions surrounding the genetic loci for resistance to intracellular parasites (Ity, Lsh, and Bcg), DNA repair responses (Rep-1), and the cytoskeletal protein villin (Vil).

PubMed Central

Mock, B A; Holiday, D L; Cerretti, D P; Darnell, S C; O'Brien, A D; Potter, M

1994-01-01

The interval of mouse chromosome 1 extending from Idh-1 to Pep-3 harbors the natural resistance gene Ity/Lsh/Bcg; it controls the outcome of infection with Salmonella typhimurium, Leishmania donovani, and several Mycobacterium species. This region also contains a DNA repair gene, Rep-1, which determines the rapidity with which double-strand breaks in chromatin are repaired. BALB/cAnPt and DBA/2N mice differ in their phenotypic expression of these genes. To generate appropriate strains of mice for the study of these genes, a series of 10 C.D2 congenic strains recombinant across a 28-centimorgan interval of mouse chromosome 1 extending from Idh-1 to Pep-3 were derived from crosses of the C.D2-Idh-1 Pep-3 congenic strain back to BALB/cAn. Analyses of these recombinant strains will allow the correlation of biological-immunological phenotypes with defined genetic regions. PMID:8262646

Prolonged Operative Duration Increases Risk of Surgical Site Infections: A Systematic Review

PubMed Central

Chen, Brian Po-Han; Soleas, Ireena M.; Ferko, Nicole C.; Cameron, Chris G.; Hinoul, Piet

2017-01-01

Abstract Background: The incidence of surgical site infection (SSI) across surgical procedures, specialties, and conditions is reported to vary from 0.1% to 50%. Operative duration is often cited as an independent and potentially modifiable risk factor for SSI. The objective of this systematic review was to provide an in-depth understanding of the relation between operating time and SSI. Patients and Methods: This review included 81 prospective and retrospective studies. Along with study design, likelihood of SSI, mean operative times, time thresholds, effect measures, confidence intervals, and p values were extracted. Three meta-analyses were conducted, whereby odds ratios were pooled by hourly operative time thresholds, increments of increasing operative time, and surgical specialty. Results: Pooled analyses demonstrated that the association between extended operative time and SSI typically remained statistically significant, with close to twice the likelihood of SSI observed across various time thresholds. The likelihood of SSI increased with increasing time increments; for example, a 13%, 17%, and 37% increased likelihood for every 15 min, 30 min, and 60 min of surgery, respectively. On average, across various procedures, the mean operative time was approximately 30 min longer in patients with SSIs compared with those patients without. Conclusions: Prolonged operative time can increase the risk of SSI. Given the importance of SSIs on patient outcomes and health care economics, hospitals should focus efforts to reduce operative time. PMID:28832271

Time estimation by patients with frontal lesions and by Korsakoff amnesics.

PubMed

Mimura, M; Kinsbourne, M; O'Connor, M

2000-07-01

We studied time estimation in patients with frontal damage (F) and alcoholic Korsakoff (K) patients in order to differentiate between the contributions of working memory and episodic memory to temporal cognition. In Experiment 1, F and K patients estimated time intervals between 10 and 120 s less accurately than matched normal and alcoholic control subjects. F patients were less accurate than K patients at short (< 1 min) time intervals whereas K patients increasingly underestimated durations as intervals grew longer. F patients overestimated short intervals in inverse proportion to their performance on the Wisconsin Card Sorting Test. As intervals grew longer, overestimation yielded to underestimation for F patients. Experiment 2 involved time estimation while counting at a subjective 1/s rate. F patients' subjective tempo, though relatively rapid, did not fully explain their overestimation of short intervals. In Experiment 3, participants produced predetermined time intervals by depressing a mouse key. K patients underproduced longer intervals. F patients produced comparably to normal participants, but were extremely variable. Findings suggest that both working memory and episodic memory play an individual role in temporal cognition. Turnover within a short-term working memory buffer provides a metric for temporal decisions. The depleted working memory that typically attends frontal dysfunction may result in quicker turnover, and this may inflate subjective duration. On the other hand, temporal estimation beyond 30 s requires episodic remembering, and this puts K patients at a disadvantage.

Method and apparatus for assessing cardiovascular risk

NASA Technical Reports Server (NTRS)

Albrecht, Paul (Inventor); Bigger, J. Thomas (Inventor); Cohen, Richard J. (Inventor)

1998-01-01

The method for assessing risk of an adverse clinical event includes detecting a physiologic signal in the subject and determining from the physiologic signal a sequence of intervals corresponding to time intervals between heart beats. The long-time structure of fluctuations in the intervals over a time period of more than fifteen minutes is analyzed to assess risk of an adverse clinical event. In a preferred embodiment, the physiologic signal is an electrocardiogram and the time period is at least fifteen minutes. A preferred method for analyzing the long-time structure variability in the intervals includes computing the power spectrum and fitting the power spectrum to a power law dependence on frequency over a selected frequency range such as 10.sup.-4 to 10.sup.-2 Hz. Characteristics of the long-time structure fluctuations in the intervals is used to assess risk of an adverse clinical event.

The effects of context and musical training on auditory temporal-interval discrimination.

PubMed

Banai, Karen; Fisher, Shirley; Ganot, Ron

2012-02-01

Non sensory factors such as stimulus context and musical experience are known to influence auditory frequency discrimination, but whether the context effect extends to auditory temporal processing remains unknown. Whether individual experiences such as musical training alter the context effect is also unknown. The goal of the present study was therefore to investigate the effects of stimulus context and musical experience on auditory temporal-interval discrimination. In experiment 1, temporal-interval discrimination was compared between fixed context conditions in which a single base temporal interval was presented repeatedly across all trials and variable context conditions in which one of two base intervals was randomly presented on each trial. Discrimination was significantly better in the fixed than in the variable context conditions. In experiment 2 temporal discrimination thresholds of musicians and non-musicians were compared across 3 conditions: a fixed context condition in which the target interval was presented repeatedly across trials, and two variable context conditions differing in the frequencies used for the tones marking the temporal intervals. Musicians outperformed non-musicians on all 3 conditions, but the effects of context were similar for the two groups. Overall, it appears that, like frequency discrimination, temporal-interval discrimination benefits from having a fixed reference. Musical experience, while improving performance, did not alter the context effect, suggesting that improved discrimination skills among musicians are probably not an outcome of more sensitive contextual facilitation or predictive coding mechanisms. Copyright © 2011 Elsevier B.V. All rights reserved.

Extended Time Testing Accommodations for Students with Disabilities: Answers to Five Fundamental Questions

ERIC Educational Resources Information Center

Lovett, Benjamin J.

2010-01-01

Extended time is one of the most common testing accommodations provided to students with disabilities. It is also controversial; critics of extended time accommodations argue that extended time is used too readily, without concern for how it changes the skills measured by tests, leading to scores that cannot be compared fairly with those of other…

The error and bias of supplementing a short, arid climate, rainfall record with regional vs. global frequency analysis

NASA Astrophysics Data System (ADS)

Endreny, Theodore A.; Pashiardis, Stelios

2007-02-01

SummaryRobust and accurate estimates of rainfall frequencies are difficult to make with short, and arid-climate, rainfall records, however new regional and global methods were used to supplement such a constrained 15-34 yr record in Cyprus. The impact of supplementing rainfall frequency analysis with the regional and global approaches was measured with relative bias and root mean square error (RMSE) values. Analysis considered 42 stations with 8 time intervals (5-360 min) in four regions delineated by proximity to sea and elevation. Regional statistical algorithms found the sites passed discordancy tests of coefficient of variation, skewness and kurtosis, while heterogeneity tests revealed the regions were homogeneous to mildly heterogeneous. Rainfall depths were simulated in the regional analysis method 500 times, and then goodness of fit tests identified the best candidate distribution as the general extreme value (GEV) Type II. In the regional analysis, the method of L-moments was used to estimate location, shape, and scale parameters. In the global based analysis, the distribution was a priori prescribed as GEV Type II, a shape parameter was a priori set to 0.15, and a time interval term was constructed to use one set of parameters for all time intervals. Relative RMSE values were approximately equal at 10% for the regional and global method when regions were compared, but when time intervals were compared the global method RMSE had a parabolic-shaped time interval trend. Relative bias values were also approximately equal for both methods when regions were compared, but again a parabolic-shaped time interval trend was found for the global method. The global method relative RMSE and bias trended with time interval, which may be caused by fitting a single scale value for all time intervals.

Dissociations between interval timing and intertemporal choice following administration of fluoxetine, cocaine, or methamphetamine

PubMed Central

Heilbronner, Sarah R.; Meck, Warren. H.

2014-01-01

The goal of our study was to characterize the relationship between intertemporal choice and interval timing, including determining how drugs that modulate brain serotonin and dopamine levels influence these two processes. In Experiment 1, rats were tested on a standard 40-s peak-interval procedure following administration of fluoxetine (3, 5, or 8 mg/kg) or vehicle to assess basic effects on interval timing. In Experiment 2, rats were tested in a novel behavioral paradigm intended to simultaneously examine interval timing and impulsivity. Rats performed a variant of the bi-peak procedure using 10-s and 40-s target durations with an additional “defection” lever that provided the possibility of a small, immediate reward. Timing functions remained relatively intact, and ‘patience’ across subjects correlated with peak times, indicating a negative relationship between ‘patience’ and clock speed. We next examined the effects of fluoxetine (5 mg/kg), cocaine (15 mg/kg), or methamphetamine (1 mg/kg) on task performance. Fluoxetine reduced impulsivity as measured by defection time without corresponding changes in clock speed. In contrast, cocaine and methamphetamine both increased impulsivity and clock speed. Thus, variations in timing may mediate intertemporal choice via dopaminergic inputs. However, a separate, serotonergic system can affect intertemporal choice without affecting interval timing directly. PMID:24135569

Scale size-dependent characteristics of the nightside aurora

NASA Astrophysics Data System (ADS)

Humberset, B. K.; Gjerloev, J. W.; Samara, M.; Michell, R. G.

2017-02-01

We have determined the spatiotemporal characteristics of the magnetosphere-ionosphere (M-I) coupling using auroral imaging. Observations at fixed positions for an extended period of time are provided by a ground-based all-sky imager measuring the 557.7 nm auroral emissions. We report on a single event of nightside aurora (˜22 magnetic local time) preceding a substorm onset. To determine the spatiotemporal characteristics, we perform an innovative analysis of an all-sky imager movie (19 min duration, images at 3.31 Hz) that combines a two-dimensional spatial fast Fourier transform with a temporal correlation. We find a scale size-dependent variability where the largest scale sizes are stable on timescales of minutes while the small scale sizes are more variable. When comparing two smaller time intervals of different types of auroral displays, we find a variation in their characteristics. The characteristics averaged over the event are in remarkable agreement with the spatiotemporal characteristics of the nightside field-aligned currents during moderately disturbed times. Thus, two different electrodynamical parameters of the M-I coupling show similar behavior. This gives independent support to the claim of a system behavior that uses repeatable solutions to transfer energy and momentum from the magnetosphere to the ionosphere.

Pituitary-ovarian hormone levels and symptoms in oral contraceptive users: comparison of a 21/7-day and extended regimen.

PubMed

Kuehl, Thomas J; Speikermann, A Michael; Willis, Sherilyn A; Coffee, Andrea; Sulak, Patricia J

2008-04-01

To compare hormone levels and symptoms during transition from standard to extended oral contraceptive (OC) regimens. A prospective analysis of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and inhibin-B levels with symptoms during 21/7-day vs. 168/7-day extended OCs containing 3 mg of drosperinone and 30 mcg of ethinyl estradiol. Blood samples were obtained from 10 subjects in each of 4 weeks in the 21/7 regimen, in the first 6 weeks of the extended regimen, and again the week before, the week of and the week after the 7-day hormone-free interval (HFI) at the end of the extended regimen. All 4 hormones followed a cyclic pattern with decreasing levels during the 3 active pill weeks of the 21/7 cycle, followed by an increase during the 7-day HFI, which continued into the extended regimen. Levels then decreased during the extended regimen and remained low at week 24. During the 7-day HFI after the extended regimen FSH and LH again increased above baseline (p > 0.07). Hormone withdrawal symptoms increased at the end of 21 active pills with increasing severity during the 7-day HFI. Absence of pituitary and ovarian suppression associated with HFI leads to fluctuations in hormones and associated hormone withdrawal symptoms.

The effect of extending the pill-free interval on follicular activity: triphasic norgestimate/35 micro g ethinyl estradiol versus monophasic levonorgestrel/20 micro g ethinyl estradiol.

PubMed

Creinin, Mitchell D; Lippman, Joel S; Eder, Scott E; Godwin, Amy J; Olson, William

2002-09-01

This study was designed to evaluate follicular activity in women taking oral contraceptives with imposed imperfect compliance. After completing a 28-day cycle of either triphasic norgestimate/EE (NGM/EE) (Ortho Tri-Cyclen, Ortho-McNeil Pharmaceutical, Raritan, NJ) or monophasic levonorgestrel/EE (LNG/EE) (Alesse, Wyeth-Ayerst Laboratories, Philadelphia, PA), women were instructed to intentionally "miss" the first two active pills of the next pack. The first two tablets in the second treatment cycle were deliberately omitted, thereby extending the pill-free interval from 7 days to 9 days. Subjects were randomized to take NGM/EE (n = 40) or LNG/EE (n = 39) for two consecutive cycles. The mean maximum follicular diameter was significantly greater in women taking LNG/EE than in those taking NGM/EE (16.4 +/- 7.1 mm vs. 12.6 +/- 8.3 mm, p = 0.047). The LNG/EE group had significantly higher median serum estradiol concentrations compared to women taking NGM/EE on pill Days 10 [29.5 pg/mL (range: 10.0-540.0 pg/mL) vs. 2.5 pg/mL (range: 2.0-6.0 pg/mL), p < 0.001] and 14 [11.0 pg/mL (range: 2.0-416.0 pg/mL) vs. 2.0 pg/mL (range: 2.0-3.0 pg/mL), p = 0.001]. Two women in the NGM/EE group and three women in the LNG/EE group had at least one progesterone level > or =3 ng/mL; none of these women demonstrated a maximum follicular diameter >13 mm. Significantly greater follicular activity was observed after an extended pill-free interval in women taking LNG/EE compared to those taking triphasic NGM/EE. The clinical implications of these findings require further study.

Summary of hydrologic testing of the Floridan aquifer system at Fort Stewart, Georgia

USGS Publications Warehouse

Gonthier, Gerard

2011-01-01

Flowmeter surveys at the study site indicate several permeable zones within the Floridan aquifer system. The Upper Floridan aquifer is composed of two water-bearing zones-the upper zone and the lower zone. The upper zone extends from 520 to 650 feet below land surface, contributes 96 percent of the total flow, and is more permeable than the lower zone, which extends from 650 to 705 feet below land surface and contributes the remaining 4 percent of the flow. The Lower Floridan aquifer consists of three zones at depths of 912-947, 1,090-1,139, and 1,211-1,250 feet below land surface that are inter-layered with three less-permeable zones. The Lower Floridan confining unit includes a permeable zone that extends from 793 to 822 feet below land surface. Horizontal hydraulic conductivity values of the Lower Floridan confining unit derived from slug tests within four packer-isolated intervals were from 2 to 20 feet per day, with a high value of 70 feet per day obtained for one of the intervals. Aquifer testing, using analytical techniques and model simulation, indicated the Upper Floridan aquifer had a transmissivity of about 100,000 feet squared per day, and the Lower Floridan aquifer had a transmissivity of 7,000 feet squared per day. Flowmeter surveys, slug tests within packer-isolated intervals, and parameter-estimation results indicate that the hydraulic properties of the Lower Floridan confining unit are similar to those of the Lower Floridan aquifer. Water-level data, for each aquifer test, were filtered for external influences such as barometric pressure, earth-tide effects, and long-term trends to enable detection of small water-level responses to aquifer-test pumping of less than 1 foot. During a 72-hour aquifer test of the Lower Floridan aquifer, a drawdown response of 0.3 to 0.4 foot was observed in two Upper Floridan aquifer wells, one of which was more than 1 mile away from the pumped well.

Characterization of Cardiac Time Intervals in Healthy Bonnet Macaques (Macaca radiata) by Using an Electronic Stethoscope

PubMed Central

Kamran, Haroon; Salciccioli, Louis; Pushilin, Sergei; Kumar, Paraag; Carter, John; Kuo, John; Novotney, Carol; Lazar, Jason M

2011-01-01

Nonhuman primates are used frequently in cardiovascular research. Cardiac time intervals derived by phonocardiography have long been used to assess left ventricular function. Electronic stethoscopes are simple low-cost systems that display heart sound signals. We assessed the use of an electronic stethoscope to measure cardiac time intervals in 48 healthy bonnet macaques (age, 8 ± 5 y) based on recorded heart sounds. Technically adequate recordings were obtained from all animals and required 1.5 ± 1.3 min. The following cardiac time intervals were determined by simultaneously recording acoustic and single-lead electrocardiographic data: electromechanical activation time (QS1), electromechanical systole (QS2), the time interval between the first and second heart sounds (S1S2), and the time interval between the second and first sounds (S2S1). QS2 was correlated with heart rate, mean arterial pressure, diastolic blood pressure, and left ventricular ejection time determined by using echocardiography. S1S2 correlated with heart rate, mean arterial pressure, diastolic blood pressure, left ventricular ejection time, and age. S2S1 correlated with heart rate, mean arterial pressure, diastolic blood pressure, systolic blood pressure, and left ventricular ejection time. QS1 did not correlate with any anthropometric or echocardiographic parameter. The relation S1S2/S2S1 correlated with systolic blood pressure. On multivariate analyses, heart rate was the only independent predictor of QS2, S1S2, and S2S1. In conclusion, determination of cardiac time intervals is feasible and reproducible by using an electrical stethoscope in nonhuman primates. Heart rate is a major determinant of QS2, S1S2, and S2S1 but not QS1; regression equations for reference values for cardiac time intervals in bonnet macaques are provided. PMID:21439218

The Chaotic Light Curves of Accreting Black Holes

NASA Technical Reports Server (NTRS)

Kazanas, Demosthenes

2007-01-01

We present model light curves for accreting Black Hole Candidates (BHC) based on a recently developed model of these sources. According to this model, the observed light curves and aperiodic variability of BHC are due to a series of soft photon injections at random (Poisson) intervals and the stochastic nature of the Comptonization process in converting these soft photons to the observed high energy radiation. The additional assumption of our model is that the Comptonization process takes place in an extended but non-uniform hot plasma corona surrounding the compact object. We compute the corresponding Power Spectral Densities (PSD), autocorrelation functions, time skewness of the light curves and time lags between the light curves of the sources at different photon energies and compare our results to observation. Our model reproduces the observed light curves well, in that it provides good fits to their overall morphology (as manifest by the autocorrelation and time skewness) and also to their PSDs and time lags, by producing most of the variability power at time scales 2 a few seconds, while at the same time allowing for shots of a few msec in duration, in accordance with observation. We suggest that refinement of this type of model along with spectral and phase lag information can be used to probe the structure of this class of high energy sources.

New Data On The Distribution Of Calcareous Nannofossils During And After The Paleocene/Eocene Transition

NASA Astrophysics Data System (ADS)

Raffi, I.

2004-12-01

Major changes occur among calcareous nannofossil assemblages at the transition from Paleocene to Eocene. In most known P/E boundary sections with complete sediment records, the changes are associated to the brief, intensive interval of global warming, the Paleocene-Eocene Thermal Maximum (PETM), and a concomitant huge perturbation of the global carbon budget, the Carbon Isotope Excursion (CIE). Changes in nannofossil assemblages include: (A) occurrence of Rhomboaster spp. - D. araneus correlative with the CIE; (B) decrease in diversification of Fasciculithus spp. at the CIE onset; (C) occurrence of Zygrhablithus bijugatus and Fasciculithus spp./ Z. bijugatus abundance cross-over within the upper part of the CIE-PETM interval; and (D) extiction of the Paleocene genus Fasciculithus just above the CIE, an event that is closely followed by the further evolution of Rhomboaster - Tribrachiatus plexus. The genus Tribrachiatus subsequently radiates over the next ˜1 million years, a time interval showing further steps in the evolutionary history of calcareous nannofossils (speciations among discoasters and sphenoliths) during the Eocene. Quantitative analyses of selected calcareous nannofossils in deep-sea sections recovered from the Atlantic (DSDP Site 550, ODP Site 929, and ODP Sites 1262 and 1263 of Leg 208) and paleo-equatorial Pacific (ODP Sites 1215, 1220, 1221 of Leg 199) provide new informations about calcareous nannofossils across the Paleocene/Eocene transition interval. The distinctive Rhomboaster spp. - D. araneus association (RD) was previously considered to have a marked provincialism, restricted to the Atlantic Ocean and partially extending to the Tethys seaway and westernmost Indian Ocean. Detailed study of Leg 199 sections (from equatorial Pacific) and preliminary analyses at the P/E boundary of ODP Site 929 (from Ceara Rise in western equatorial Atlantic) and ODP Sites 1262 and 1263 (from Walvis Ridge in southern Atlantic) indicate some difference in the RD distribution. The sudden appearance and short co-existence of R. calcitrapa gr. and D. araneus, and the lowermost occurrence of R. cuspis at the onset of CIE clearly can be extended to the equatorial regions of the Atlantic as well as the Pacific Ocean. The genus Fasciculithus undergoes a substantial decrease in diversification at the onset of CIE, and perish completely shortly afterwards. This significant turnover appears to represent a global event observed in all the known P/E boundary sections from different oceans and paleo-latitudes. The abundance cross-over between Fasciculithus spp. and Z. bijugatus has been observed to occur within the the CIE-PETM interval in several deep-sea sections. In the central paleo-equatorial Pacific Ocean, however, Z. bijugatus specimens were not present at all, whereas a marked increase in abundance of R. cuspis was observed in conjunction with the final decline of Fasciculithus spp. Data from the western paleo-equatorial Atlantic Ocean (Site 929) shows only few Z. bijugatus, implying that this particular early Eocene turnover is absent in these equatorial regions. Thoracosphaera spp. shows a short abundance peak immediately above the carbonate barren interval at the P/E boundary, during the CIE, at paleo-equatorial Pacific Site 1220, which probably reflects a stressed surface water environment.

Rapid fibrin plug formation within cutaneous ablative fractional CO2 laser lesions.

PubMed

Kositratna, Garuna; Evers, Michael; Sajjadi, Amir; Manstein, Dieter

2016-02-01

Ablative fractional laser procedures have been shown to facilitate topical drug delivery into the skin. Past studies have mainly used ex vivo models to demonstrate enhanced drug delivery and in vivo studies have investigated laser created channels over a time course of days and weeks rather than within the first few minutes and hours after exposures. We have noticed rapid in vivo fibrin plug formation within ablative fractional laser lesions impairing passage through the laser created channels. In vivo laser exposures were performed in a porcine model. A fractional CO2 laser (AcuPulse™ system, AcuScan 120™ handpiece, Lumenis, Inc., Yokneam, Israel) was programmed in quasi-continuous wave (QCW) mode, at 40W, 50 mJ per pulse, 5% coverage, nominal 120 µm spot size, 8 × 8 mm square pattern, 169 MTZs per scan. Six millimeters punch biopsies were procured at 0, 2, 5, 10, 15, 30, 60, 90 minutes after completion of each scan, then fixed in 10% formalin. 12 repeats were performed of each time point. Skin samples were processed for serial vertically cut paraffin sections (5 μm collected every 25 μm) then H&E and special immunohistochemistry staining for fibrin and platelet. Dimensions of Microscopic Treatment Zones (MTZs) and extent of fibrin plug were assessed and quantified histologically. Ex vivo laser exposures of the identical laser parameter were performed on porcine and human skin at different storage conditions. Histology procured at various predetermined time intervals after in vivo fractional CO2 laser exposures revealed a rapidly forming fibrin plug initiating at the bottom of the MTZ lesions. At longer time intervals, the fibrin plug was extending towards the superficial sections. Within the first 5 minutes, more than 25% length of the entire laser-ablated channel was filled with a fibrin plug. With increased time intervals, the cavity was progressively filled with a fibrin plug. At 90 minutes, more than 90% length of the entire laser-ablated channel was occluded. Ex vivo exposures failed to produce any significant fibrin plug formation. The current study has demonstrated rapid fibrin plug formation after ablative fractional laser procedures. It was shown that the passage through laser created pathways is critically time dependent for in vivo exposures. In contrast, ex vivo exposures do not exhibit such time dependent passage capacity. In particular, drug, substance, and cell delivery studies for ablative fractional laser treatments should take early fibrin plug formation into consideration and further investigate the impact on transdermal delivery. © 2015 Wiley Periodicals, Inc.

Statistical inference for the within-device precision of quantitative measurements in assay validation.

PubMed

Liu, Jen-Pei; Lu, Li-Tien; Liao, C T

2009-09-01

Intermediate precision is one of the most important characteristics for evaluation of precision in assay validation. The current methods for evaluation of within-device precision recommended by the Clinical Laboratory Standard Institute (CLSI) guideline EP5-A2 are based on the point estimator. On the other hand, in addition to point estimators, confidence intervals can provide a range for the within-device precision with a probability statement. Therefore, we suggest a confidence interval approach for assessment of the within-device precision. Furthermore, under the two-stage nested random-effects model recommended by the approved CLSI guideline EP5-A2, in addition to the current Satterthwaite's approximation and the modified large sample (MLS) methods, we apply the technique of generalized pivotal quantities (GPQ) to derive the confidence interval for the within-device precision. The data from the approved CLSI guideline EP5-A2 illustrate the applications of the confidence interval approach and comparison of results between the three methods. Results of a simulation study on the coverage probability and expected length of the three methods are reported. The proposed method of the GPQ-based confidence intervals is also extended to consider the between-laboratories variation for precision assessment.

More accurate, calibrated bootstrap confidence intervals for correlating two autocorrelated climate time series

NASA Astrophysics Data System (ADS)

Olafsdottir, Kristin B.; Mudelsee, Manfred

2013-04-01

Estimation of the Pearson's correlation coefficient between two time series to evaluate the influences of one time depended variable on another is one of the most often used statistical method in climate sciences. Various methods are used to estimate confidence interval to support the correlation point estimate. Many of them make strong mathematical assumptions regarding distributional shape and serial correlation, which are rarely met. More robust statistical methods are needed to increase the accuracy of the confidence intervals. Bootstrap confidence intervals are estimated in the Fortran 90 program PearsonT (Mudelsee, 2003), where the main intention was to get an accurate confidence interval for correlation coefficient between two time series by taking the serial dependence of the process that generated the data into account. However, Monte Carlo experiments show that the coverage accuracy for smaller data sizes can be improved. Here we adapt the PearsonT program into a new version called PearsonT3, by calibrating the confidence interval to increase the coverage accuracy. Calibration is a bootstrap resampling technique, which basically performs a second bootstrap loop or resamples from the bootstrap resamples. It offers, like the non-calibrated bootstrap confidence intervals, robustness against the data distribution. Pairwise moving block bootstrap is used to preserve the serial correlation of both time series. The calibration is applied to standard error based bootstrap Student's t confidence intervals. The performances of the calibrated confidence intervals are examined with Monte Carlo simulations, and compared with the performances of confidence intervals without calibration, that is, PearsonT. The coverage accuracy is evidently better for the calibrated confidence intervals where the coverage error is acceptably small (i.e., within a few percentage points) already for data sizes as small as 20. One form of climate time series is output from numerical models which simulate the climate system. The method is applied to model data from the high resolution ocean model, INALT01 where the relationship between the Agulhas Leakage and the North Brazil Current is evaluated. Preliminary results show significant correlation between the two variables when there is 10 year lag between them, which is more or less the time that takes the Agulhas Leakage water to reach the North Brazil Current. Mudelsee, M., 2003. Estimating Pearson's correlation coefficient with bootstrap confidence interval from serially dependent time series. Mathematical Geology 35, 651-665.

Optimal methods for fitting probability distributions to propagule retention time in studies of zoochorous dispersal.

PubMed

Viana, Duarte S; Santamaría, Luis; Figuerola, Jordi

2016-02-01

Propagule retention time is a key factor in determining propagule dispersal distance and the shape of "seed shadows". Propagules dispersed by animal vectors are either ingested and retained in the gut until defecation or attached externally to the body until detachment. Retention time is a continuous variable, but it is commonly measured at discrete time points, according to pre-established sampling time-intervals. Although parametric continuous distributions have been widely fitted to these interval-censored data, the performance of different fitting methods has not been evaluated. To investigate the performance of five different fitting methods, we fitted parametric probability distributions to typical discretized retention-time data with known distribution using as data-points either the lower, mid or upper bounds of sampling intervals, as well as the cumulative distribution of observed values (using either maximum likelihood or non-linear least squares for parameter estimation); then compared the estimated and original distributions to assess the accuracy of each method. We also assessed the robustness of these methods to variations in the sampling procedure (sample size and length of sampling time-intervals). Fittings to the cumulative distribution performed better for all types of parametric distributions (lognormal, gamma and Weibull distributions) and were more robust to variations in sample size and sampling time-intervals. These estimated distributions had negligible deviations of up to 0.045 in cumulative probability of retention times (according to the Kolmogorov-Smirnov statistic) in relation to original distributions from which propagule retention time was simulated, supporting the overall accuracy of this fitting method. In contrast, fitting the sampling-interval bounds resulted in greater deviations that ranged from 0.058 to 0.273 in cumulative probability of retention times, which may introduce considerable biases in parameter estimates. We recommend the use of cumulative probability to fit parametric probability distributions to propagule retention time, specifically using maximum likelihood for parameter estimation. Furthermore, the experimental design for an optimal characterization of unimodal propagule retention time should contemplate at least 500 recovered propagules and sampling time-intervals not larger than the time peak of propagule retrieval, except in the tail of the distribution where broader sampling time-intervals may also produce accurate fits.

Factors influencing pre-hospital care time intervals in Iran: a qualitative study.

PubMed

Khorasani-Zavareh, Davoud; Mohammadi, Reza; Bohm, Katarina

2018-06-23

Pre-hospital time management provides better access to victims of road traffic crashes (RTCs) and can help minimize preventable deaths, injuries and disabilities. While most studies have been focused on measuring various time intervals in the pre-hospital phase, to our best knowledge there is no study exploring the barriers and facilitators that affects these various intervals qualitatively. The present study aimed to explore factors affecting various time intervals relating to road traffic incidents in the pre-hospital phase and provides suggestions for improvements in Iran. The study was conducted during 2013-2014 at both the national and local level in Iran. Overall, 18 face-to-face interviews with emergency medical services (EMS) personnel were used for data collection. Qualitative content analysis was employed to analyze the data. The most important barriers in relation to pre-hospital intervals were related to the manner of cooperation by members of the public with the EMS and their involvement at the crash scene, as well as to pre-hospital system factors, including the number and location of EMS facilities, type and number of ambulances and manpower. These factors usually affect how rapidly the EMS can arrive at the scene of the crash and how quickly victims can be transferred to hospital. These two categories have six main themes: notification interval; activation interval; response interval; on-scene interval; transport interval; and delivery interval. Despite more focus on physical resources, cooperation from members of the public needs to be taken in account in order to achieve better pre-hospital management of the various intervals, possibly through the use of public education campaigns.

A randomized clinical trial comparing an extended-use hygroscopic condenser humidifier with heated-water humidification in mechanically ventilated patients.

PubMed

Kollef, M H; Shapiro, S D; Boyd, V; Silver, P; Von Harz, B; Trovillion, E; Prentice, D

1998-03-01

To determine the safety and cost-effectiveness of mechanical ventilation with an extended-use hygroscopic condenser humidifier (Duration; Nellcor Puritan-Bennett; Eden Prairie, Minn) compared with mechanical ventilation with heated-water humidification. Prospective randomized clinical trial. Medical and surgical ICUs of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. Three hundred ten consecutive qualified patients undergoing mechanical ventilation. Patients requiring mechanical ventilation were randomly assigned to receive humidification with either an extended-use hygroscopic condenser humidifier (for up to the first 7 days of mechanical ventilation) or heated-water humidification. Occurrence of ventilator-associated pneumonia, endotracheal tube occlusion, duration of mechanical ventilation, lengths of intensive care and hospitalization, acquired multiorgan dysfunction, and hospital mortality. One hundred sixty-three patients were randomly assigned to receive humidification with an extended-use hygroscopic condenser humidifier, and 147 patients were randomly assigned to receive heated-water humidification. The two groups were similar at the time of randomization with regard to demographic characteristics, ICU admission diagnoses, and severity of illness. Risk factors for the development of ventilator-associated pneumonia were also similar during the study period for both treatment groups. Ventilator-associated pneumonia was seen in 15 (9.2%) patients receiving humidification with an extended-use hygroscopic condenser humidifier and in 15 (10.2%) patients receiving heated-water humidification (relative risk, 0.90; 95% confidence interval=0.46 to 1.78; p=0.766). No statistically significant differences for hospital mortality, duration of mechanical ventilation, lengths of stay in the hospital ICU, or acquired organ system derangements were found between the two treatment groups. No episode of endotracheal tube occlusion occurred during the study period in either treatment group. The total cost of providing humidification was $2,605 for patients receiving a hygroscopic condenser humidifier compared with $5,625 for patients receiving heated-water humidification. Our findings suggest that the initial application of an extended-use hygroscopic condenser humidifier is a safe and more cost-effective method of providing humidification to patients requiring mechanical ventilation compared with heated-water humidification.

Closed-form solutions of performability. [modeling of a degradable buffer/multiprocessor system

NASA Technical Reports Server (NTRS)

Meyer, J. F.

1981-01-01

Methods which yield closed form performability solutions for continuous valued variables are developed. The models are similar to those employed in performance modeling (i.e., Markovian queueing models) but are extended so as to account for variations in structure due to faults. In particular, the modeling of a degradable buffer/multiprocessor system is considered whose performance Y is the (normalized) average throughput rate realized during a bounded interval of time. To avoid known difficulties associated with exact transient solutions, an approximate decomposition of the model is employed permitting certain submodels to be solved in equilibrium. These solutions are then incorporated in a model with fewer transient states and by solving the latter, a closed form solution of the system's performability is obtained. In conclusion, some applications of this solution are discussed and illustrated, including an example of design optimization.

Fault activation by hydraulic fracturing in western Canada.

PubMed

Bao, Xuewei; Eaton, David W

2016-12-16

Hydraulic fracturing has been inferred to trigger the majority of injection-induced earthquakes in western Canada, in contrast to the Midwestern United States, where massive saltwater disposal is the dominant triggering mechanism. A template-based earthquake catalog from a seismically active Canadian shale play, combined with comprehensive injection data during a 4-month interval, shows that earthquakes are tightly clustered in space and time near hydraulic fracturing sites. The largest event [moment magnitude (M W ) 3.9] occurred several weeks after injection along a fault that appears to extend from the injection zone into crystalline basement. Patterns of seismicity indicate that stress changes during operations can activate fault slip to an offset distance of >1 km, whereas pressurization by hydraulic fracturing into a fault yields episodic seismicity that can persist for months. Copyright © 2016, American Association for the Advancement of Science.

The apsidal motion of the eccentric eclipsing binary DI Herculis - An apparent discrepancy with general relativity

NASA Technical Reports Server (NTRS)

Guinan, E. F.; Maloney, F. P.

1985-01-01

The apsidal motion of the eccentric eclipsing binary DI Herculis (HD 175227) is determined from an analysis of the available observations and eclipse timings from 1959 to 1984. Least squares solutions to the primary and secondary minima extending over an 84-yr interval yielded a small advance of periastron omega dot of 0.65 deg/100 yr + or - 0.18/100 yr. The observed advance of the periastron is about one seventh of the theoretical value of 4.27 deg/100 yr that is expected from the combined relativistic and classical effects. The discrepancy is about -3.62 deg/100 yr, or a magnitude of about 20 sigma. Classical mechanisms which explain the discrepancy are discussed, together with the possibility that there may be problems with general relativity itself.

Interval stability for complex systems

NASA Astrophysics Data System (ADS)

Klinshov, Vladimir V.; Kirillov, Sergey; Kurths, Jürgen; Nekorkin, Vladimir I.

2018-04-01

Stability of dynamical systems against strong perturbations is an important problem of nonlinear dynamics relevant to many applications in various areas. Here, we develop a novel concept of interval stability, referring to the behavior of the perturbed system during a finite time interval. Based on this concept, we suggest new measures of stability, namely interval basin stability (IBS) and interval stability threshold (IST). IBS characterizes the likelihood that the perturbed system returns to the stable regime (attractor) in a given time. IST provides the minimal magnitude of the perturbation capable to disrupt the stable regime for a given interval of time. The suggested measures provide important information about the system susceptibility to external perturbations which may be useful for practical applications. Moreover, from a theoretical viewpoint the interval stability measures are shown to bridge the gap between linear and asymptotic stability. We also suggest numerical algorithms for quantification of the interval stability characteristics and demonstrate their potential for several dynamical systems of various nature, such as power grids and neural networks.

Analysis of single ion channel data incorporating time-interval omission and sampling

PubMed Central

The, Yu-Kai; Timmer, Jens

2005-01-01

Hidden Markov models are widely used to describe single channel currents from patch-clamp experiments. The inevitable anti-aliasing filter limits the time resolution of the measurements and therefore the standard hidden Markov model is not adequate anymore. The notion of time-interval omission has been introduced where brief events are not detected. The developed, exact solutions to this problem do not take into account that the measured intervals are limited by the sampling time. In this case the dead-time that specifies the minimal detectable interval length is not defined unambiguously. We show that a wrong choice of the dead-time leads to considerably biased estimates and present the appropriate equations to describe sampled data. PMID:16849220

Digital time delay

DOEpatents

Martin, A.D.

1986-05-09

Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

Broadband Seismic Array Observation along a ~2000-km-long Linear Profile in South China

NASA Astrophysics Data System (ADS)

Ai, Y.; Zhao, L.; Chen, L.; Zheng, T.; He, Y.; Jiang, M.

2010-12-01

In order to study the interior structure and geodynamic evolution of South China, we have started implementation of a linear seismic array observation in this region since December 2009. The linear array extends for ~2000 km from the northwestern continental interior all the way to the southeastern coastal area, across major tectonic units of South China including the Songpan-Ganze Orogenic Belt (SGOB) in the northwest, the Yangtze Craton (YzC) in the middle, and the Huanan Orogenic Belt (HOB) in the southeast. We plan to deploy a total of 200 broadband stations in the time period from December 2009 to June 2012. All the stations will be equipped with Guralp CMG-3ESP sensors and Ref-tek 130-1 or Ref-tek 72-A digitizers. The entire array observation includes three stages. In the time period from December 2009 to March 2011, 64 stations were deployed with a spatial interval of ~25 km from Chengdu city in Sichuan province in the west to Quanzhou city in Fujian province in the southeast of China. In the second stage, about 70 stations with a spatial interval of ~10 km will be deployed from Gonghe city in Qinghai province in the northwest to Chengdu city in the southeast in the time period from October 2010 to November 2011. In the last stage from April 2011 to June 2012, 66 stations with a spatial interval of ~25 km will be deployed to densify the station coverage along the Chengdu - Quanzhou segment of the profile. We have already analyzed the seismic data collected at the 64 stations using receiver function methods. Our preliminary results show an obvious W-E variation in the crustal thickness of the region. In particular, from inland to offshore of the Fujian Province the crustal thickness decreases, whereas the Poisson's ratio increases. These may indicate decreasing SiO2 and increasing calc-alkaline contents in the crust. The receiver function data also reveal a coherent structure of the 410-km and 660-km discontinuities along the observation profile. ACKNOWLEDGMENTS We acknowledge the financial support of SinoProbe under Grant SinoProbe-02-03

Building in efficacy: developing solutions to combat drug-resistant S. pneumoniae.

PubMed

Jacobs, M R

2004-04-01

The development of our understanding of the pharmacokinetic (PK) and pharmacodynamic (PD) principles that determine antimicrobial efficacy has advanced substantially over the last 10 years. We are now in a position to use PK/PD principles to set targets for antimicrobial design and optimisation so that we can predict eradication of specific pathogens or resistant variants when agents are used clinically. Optimisation of PK/PD parameters to enable the treatment of resistant pathogens with oral agents may not be possible with many current agents, such as some cephalosporins, macrolides and fluoroquinolones. Aminopenicillins, however, such as amoxicillin, have linear PK and have a good safety profile even at high doses. The new pharmacokinetically enhanced oral formulation of amoxicillin/clavulanate, 2000/125 mg twice daily, was designed using PK/PD principles to be able to eradicate Streptococcus pneumoniae with amoxicillin MICs of up to and including 4 mg/L, which includes most penicillin-resistant isolates. For amoxicillin and amoxicillin/clavulanate, a time above MIC (T > MIC) of 35-40% of the dosing interval (based on blood levels) is predictive of high bacteriological efficacy. This target was met by the design of a unique bilayer tablet incorporating 437.5 mg of sustained-release sodium amoxicillin in one layer plus 562.5 mg of immediate-release amoxicillin trihydrate and 62.5 mg of clavulanate potassium in the second layer, with two tablets administered for each dose. This unique design extends the bacterial killing time by increasing the T > MIC to 49% of the dosing interval against pathogens with MICs of 4 mg/L, and 60% of the dosing interval against pathogens with MICs of 2 mg/L. Based on these results, this new amoxicillin/clavulanate formulation should be highly effective in treating respiratory tract infections due to drug-resistant S. pneumoniae as well as beta-lactamase-producing pathogens, such as Haemophilus influenzae and Moraxella catarrhalis.

Quantitative maps of geomagnetic perturbation vectors during substorm onset and recovery

PubMed Central

Pothier, N M; Weimer, D R; Moore, W B

2015-01-01

We have produced the first series of spherical harmonic, numerical maps of the time-dependent surface perturbations in the Earth's magnetic field following the onset of substorms. Data from 124 ground magnetometer stations in the Northern Hemisphere at geomagnetic latitudes above 33° were used. Ground station data averaged over 5 min intervals covering 8 years (1998–2005) were used to construct pseudo auroral upper, auroral lower, and auroral electrojet (AU*, AL*, and AE*) indices. These indices were used to generate a list of substorms that extended from 1998 to 2005, through a combination of automated processing and visual checks. Events were sorted by interplanetary magnetic field (IMF) orientation (at the Advanced Composition Explorer (ACE) satellite), dipole tilt angle, and substorm magnitude. Within each category, the events were aligned on substorm onset. A spherical cap harmonic analysis was used to obtain a least error fit of the substorm disturbance patterns at 5 min intervals up to 90 min after onset. The fits obtained at onset time were subtracted from all subsequent fits, for each group of substorm events. Maps of the three vector components of the averaged magnetic perturbations were constructed to show the effects of substorm currents. These maps are produced for several specific ranges of values for the peak |AL*| index, IMF orientation, and dipole tilt angle. We demonstrate an influence of the dipole tilt angle on the response to substorms. Our results indicate that there are downward currents poleward and upward currents just equatorward of the peak in the substorms' westward electrojet. Key Points Show quantitative maps of ground geomagnetic perturbations due to substorms Three vector components mapped as function of time during onset and recovery Compare/contrast results for different tilt angle and sign of IMF Y-component PMID:26167445

On Extended Dissipativity of Discrete-Time Neural Networks With Time Delay.

PubMed

Feng, Zhiguang; Zheng, Wei Xing

2015-12-01

In this brief, the problem of extended dissipativity analysis for discrete-time neural networks with time-varying delay is investigated. The definition of extended dissipativity of discrete-time neural networks is proposed, which unifies several performance measures, such as the H∞ performance, passivity, l2 - l∞ performance, and dissipativity. By introducing a triple-summable term in Lyapunov function, the reciprocally convex approach is utilized to bound the forward difference of the triple-summable term and then the extended dissipativity criterion for discrete-time neural networks with time-varying delay is established. The derived condition guarantees not only the extended dissipativity but also the stability of the neural networks. Two numerical examples are given to demonstrate the reduced conservatism and effectiveness of the obtained results.

Evaluation of the electromechanical properties of the cardiovascular system after prolonged weightlessness

NASA Technical Reports Server (NTRS)

Bergman, S. A., Jr.; Johnson, R. L.; Hoffler, G. W.

1977-01-01

Devices and techniques for measuring and analyzing systolic time intervals and quantitative phonocardiograms were initiated during Apollo 17. The data show that the systolic time interval from Apollo 17 crewmen remained elevated longer postflight than the response criteria of heart rate, blood pressure, and percent change in leg volume all of which had returned to preflight levels by the second day postflight. Although the systolic time interval values were only slightly outside the preflight fiducial limits, this finding suggested that: the analysis of systolic time intervals may help to identify the mechanisms of postflight orthostatic intolerance by virtue of measuring ventricular function more directly and, the noninvasive technique may prove useful in determining the extent and duration of cardiovascular instability after long duration space flight. The systolic time intervals obtained on the Apollo 17 crewmen during lower body negative pressure were similar to those noted in patients with significant heart disease.

The Medical Duty Officer: An Attempt to Mitigate the Ambulance At-Hospital Interval

PubMed Central

Halliday, Megan H.; Bouland, Andrew J.; Lawner, Benjamin J.; Comer, Angela C.; Ramos, Daniel C.; Fletcher, Mark

2016-01-01

Introduction A lack of coordination between emergency medical services (EMS), emergency departments (ED) and systemwide management has contributed to extended ambulance at-hospital times at local EDs. In an effort to improve communication within the local EMS system, the Baltimore City Fire Department (BCFD) placed a medical duty officer (MDO) in the fire communications bureau. It was hypothesized that any real-time intervention suggested by the MDO would be manifested in a decrease in the EMS at-hospital time. Methods The MDO was implemented on November 11, 2013. A senior EMS paramedic was assigned to the position and was placed in the fire communication bureau from 9 a.m. to 9 p.m., seven days a week. We defined the pre-intervention period as August 2013 – October 2013 and the post-intervention period as December 2013 – February 2014. We also compared the post-intervention period to the “seasonal match control” one year earlier to adjust for seasonal variation in EMS volume. The MDO was tasked with the prospective management of city EMS resources through intensive monitoring of unit availability and hospital ED traffic. The MDO could suggest alternative transport destinations in the event of ED crowding. We collected and analyzed data from BCFD computer-aided dispatch (CAD) system for the following: ambulance response times, ambulance at-hospital interval, hospital diversion and alert status, and “suppression wait time” (defined as the total time suppression units remained on scene until ambulance arrival). The data analysis used a pre/post intervention design to examine the MDO impact on the BCFD EMS system. Results There were a total of 15,567 EMS calls during the pre-intervention period, 13,921 in the post-intervention period and 14,699 in the seasonal match control period one year earlier. The average at-hospital time decreased by 1.35 minutes from pre- to post-intervention periods and 4.53 minutes from the pre- to seasonal match control, representing a statistically significant decrease in this interval. There was also a statistically significant decrease in hospital alert time (approximately 1,700 hour decrease pre- to post-intervention periods) and suppression wait time (less than one minute decrease from pre- to post- and pre- to seasonal match control periods). The decrease in ambulance response time was not statistically significant. Conclusion Proactive deployment of a designated MDO was associated with a small, contemporaneous reduction in at-hospital time within an urban EMS jurisdiction. This project emphasized the importance of better communication between EMS systems and area hospitals as well as uniform reporting of variables for future iterations of this and similar projects. PMID:27625737

Enabling the extended compact genetic algorithm for real-parameter optimization by using adaptive discretization.

PubMed

Chen, Ying-ping; Chen, Chao-Hong

2010-01-01

An adaptive discretization method, called split-on-demand (SoD), enables estimation of distribution algorithms (EDAs) for discrete variables to solve continuous optimization problems. SoD randomly splits a continuous interval if the number of search points within the interval exceeds a threshold, which is decreased at every iteration. After the split operation, the nonempty intervals are assigned integer codes, and the search points are discretized accordingly. As an example of using SoD with EDAs, the integration of SoD and the extended compact genetic algorithm (ECGA) is presented and numerically examined. In this integration, we adopt a local search mechanism as an optional component of our back end optimization engine. As a result, the proposed framework can be considered as a memetic algorithm, and SoD can potentially be applied to other memetic algorithms. The numerical experiments consist of two parts: (1) a set of benchmark functions on which ECGA with SoD and ECGA with two well-known discretization methods: the fixed-height histogram (FHH) and the fixed-width histogram (FWH) are compared; (2) a real-world application, the economic dispatch problem, on which ECGA with SoD is compared to other methods. The experimental results indicate that SoD is a better discretization method to work with ECGA. Moreover, ECGA with SoD works quite well on the economic dispatch problem and delivers solutions better than the best known results obtained by other methods in existence.

Estimating the free gas content in Baltic Sea sediments using compressional wave velocity from marine seismic data

NASA Astrophysics Data System (ADS)

Tóth, Zsuzsanna; Spiess, Volkhard; Mogollón, José M.; Jensen, Jørn Bo

2014-12-01

A 2-D high-resolution velocity field was obtained from marine seismic data to quantify free gas content in shallow muddy sediments at in situ pressure and temperature. The velocities were acquired applying Migration Velocity Analysis on prestack time-migrated data. Compressional wave velocities are highly sensitive to free gas as very small amounts of gas can cause a significant decrease in the medium velocity. The analyzed profile crosses a depression filled with organic-rich Holocene mud in the Bornholm Basin, Baltic Sea. The interval velocity field reveals two low-velocity patches, which extend from the reversed polarity reflections marking the top of the gassy sediment layer down to the base of the Holocene mud. Average interval velocities within the gassy mud are lower than the seafloor migration velocity by up to ˜500 m/s. This decrease, using a geoacoustic model, is caused by an average 0.046% gas volume fraction. The interval velocities in individual cells of the velocity field are reduced to ˜200 m/s predicting up to 3.4% gas content. The velocity field is limited in resolution due to velocity determination at and between reflections; however, together with the stratigraphic interpretation, geological units containing free gas could be identified. Shallow gas occurs vertically throughout most of the Holocene mud in the gassy area. Comparison with biogeochemical studies at other Baltic Sea sites suggests that the distribution of free gas is likely to be patchy in the sediment, but the gas concentration may peak below the sulfate-methane transition zone and gradually decrease below.

Retrieval practice after multiple context changes, but not long retention intervals, reduces the impact of a final context change on instrumental behavior.

PubMed

Trask, Sydney; Bouton, Mark E

2018-06-01

Recent evidence from this laboratory suggests that a context switch after operant learning consistently results in a decrement in responding. One way to reduce this decrement is to train the response in multiple contexts. One interpretation of this result, rooted in stimulus sampling theory, is that conditioning of a greater number of common stimulus elements arising from more contexts causes better generalization to new contexts. An alternative explanation is that each change of context causes more effortful retrieval, and practice involving effortful retrieval results in learning that is better able to transfer to new situations. The current experiments were designed to differentiate between these two explanations for the first time in an animal learning and memory task. Experiment 1 demonstrated that the detrimental impact of a context change on an instrumental nose-poking response can be reduced by training the response in multiple contexts. Experiment 2 then found that a training procedure which inserted extended retention intervals between successive training sessions did not reduce the detrimental impact of a final context change. This occurred even though the inserted retention intervals had a detrimental impact on responding (and, thus, presumably retrieval) similar to the effect that context switches had in Experiment 1. Together, the results suggest that effortful retrieval practice may not be sufficient to reduce the negative impact of a context change on instrumental behavior. A common elements explanation which supposes that physical and temporal contextual cues do not overlap may account for the findings more readily.

Somatic, but not cognitive–affective, symptoms are associated with reduced heart rate variability in individuals with dysphoria

PubMed Central

Benvenuti, Simone Messerotti; Buodo, Giulia; Mennella, Rocco; Palomba, Daniela

2015-01-01

Background: Somatic, but not cognitive–affective, symptoms of depression have been associated with reduced heart rate variability (HRV), and with poor prognosis in cardiovascular patients. However, factors concomitant with cardiovascular diseases may confound the relationship between somatic symptoms of depression and reduced HRV. Therefore, this study examined whether reduced HRV was differentially associated with cognitive–affective and somatic symptoms of depression in medically healthy individuals with and without dysphoria. Methods: Self-reported cognitive–affective and somatic symptoms as measured with the Beck Depression Inventory-II questionnaire and time and frequency domain parameters of HRV were collected in 62 medically healthy individuals, of whom 25 with and 37 without dysphoria. Results: Somatic, but not cognitive–affective, symptoms of depression were inversely associated with SD of NN intervals (β = -0.476, p < 0.05), number of interval differences of successive NN intervals greater than 50 ms (NN50; β = -0.498, p < 0.03), and HRV total power (β = -0.494, p < 0.04) in the group with dysphoria, after controlling for sex, anxiety, and lifestyle factors. Cognitive–affective and somatic symptoms were not related to any of the HRV parameters in the group without dysphoria (all ps > 0.24). Conclusion: By showing that the relationship between somatic depressive symptoms and reduced HRV extends to medically healthy individuals with dysphoria, the present findings suggest that this association is independent of factors concomitant with cardiovascular diseases. The present study also suggests that individuals with somatic rather than cognitive–affective subsets of depressive symptoms may be at greater risk for developing cardiovascular diseases. PMID:25999905

Availability analysis of mechanical systems with condition-based maintenance using semi-Markov and evaluation of optimal condition monitoring interval

NASA Astrophysics Data System (ADS)

Kumar, Girish; Jain, Vipul; Gandhi, O. P.

2018-03-01

Maintenance helps to extend equipment life by improving its condition and avoiding catastrophic failures. Appropriate model or mechanism is, thus, needed to quantify system availability vis-a-vis a given maintenance strategy, which will assist in decision-making for optimal utilization of maintenance resources. This paper deals with semi-Markov process (SMP) modeling for steady state availability analysis of mechanical systems that follow condition-based maintenance (CBM) and evaluation of optimal condition monitoring interval. The developed SMP model is solved using two-stage analytical approach for steady-state availability analysis of the system. Also, CBM interval is decided for maximizing system availability using Genetic Algorithm approach. The main contribution of the paper is in the form of a predictive tool for system availability that will help in deciding the optimum CBM policy. The proposed methodology is demonstrated for a centrifugal pump.

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

Tahvanainen, E.; Karila, E.; Kolehmainen, J.

We recently assigned a gene for autosomal recessive cornea plana congenita (CNA2; MIM No. 217300) by linkage analysis to the approximately 3-cM interval between markers D12S82 and D12S327. Here, we extended these studies by exploiting the haplotype and linkage disequilibrium information that can be derived from the genetically isolated Finnish population and its subpopulations. By testing 32 independent families with 10 polymorphic markers in the CNA2 interval, strong allelic association between CNA2 and a set of markers with a peak at marker D12S351 was detected. Based on linkage disequilibrium analysis, the critical region for CNA2 could be narrowed to onlymore » 0.04-0.3 cM from marker D12S351, thus defining a critical interval 0.08-0.60 cM in length. These results provide a basis for highly focused positional cloning of CNA2. 18 refs., 5 figs., 1 tab.« less

An interval-valued 2-tuple linguistic group decision-making model based on the Choquet integral operator

NASA Astrophysics Data System (ADS)

Liu, Bingsheng; Fu, Meiqing; Zhang, Shuibo; Xue, Bin; Zhou, Qi; Zhang, Shiruo

2018-01-01

The Choquet integral (IL) operator is an effective approach for handling interdependence among decision attributes in complex decision-making problems. However, the fuzzy measures of attributes and attribute sets required by IL are difficult to achieve directly, which limits the application of IL. This paper proposes a new method for determining fuzzy measures of attributes by extending Marichal's concept of entropy for fuzzy measure. To well represent the assessment information, interval-valued 2-tuple linguistic context is utilised to represent information. Then, we propose a Choquet integral operator in an interval-valued 2-tuple linguistic environment, which can effectively handle the correlation between attributes. In addition, we apply these methods to solve multi-attribute group decision-making problems. The feasibility and validity of the proposed operator is demonstrated by comparisons with other models in illustrative example part.

Compression based entropy estimation of heart rate variability on multiple time scales.

PubMed

Baumert, Mathias; Voss, Andreas; Javorka, Michal

2013-01-01

Heart rate fluctuates beat by beat in a complex manner. The aim of this study was to develop a framework for entropy assessment of heart rate fluctuations on multiple time scales. We employed the Lempel-Ziv algorithm for lossless data compression to investigate the compressibility of RR interval time series on different time scales, using a coarse-graining procedure. We estimated the entropy of RR interval time series of 20 young and 20 old subjects and also investigated the compressibility of randomly shuffled surrogate RR time series. The original RR time series displayed significantly smaller compression entropy values than randomized RR interval data. The RR interval time series of older subjects showed significantly different entropy characteristics over multiple time scales than those of younger subjects. In conclusion, data compression may be useful approach for multiscale entropy assessment of heart rate variability.

The Effect of Teacher Coaching with Performance Feedback on Behavior-Specific Praise in Inclusion Classrooms

ERIC Educational Resources Information Center

Duchaine, Ellen L.; Jolivete, Kristine; Fredrick, Laura D.

2011-01-01

This study extends teacher coaching with written performance feedback as a means to increase behavior-specific praise statements (BSPS) in inclusion classrooms at the high school level. Three inclusion math teachers increased their use of BSPS during mathematics instruction. On-task intervals and frequency of BSPS were measured throughout the…

Disturbance and productivity interactions mediate stability of forest composition and structure

Treesearch

Christopher D. O' Connor; Donald A. Falk; Ann M. Lynch; Thomas W. Swetnam; Craig P. Wilcox

2017-01-01

Fire is returning to many conifer-dominated forests where species composition and structure have been altered by fire exclusion. Ecological effects of these fires are influenced strongly by the degree of forest change during the fire-free period. Response of fire-adapted species assemblages to extended fire-free intervals is highly variable, even in communities with...

40 CFR 1515.9 - Extending CEQ's time to respond.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Extending CEQ's time to respond. 1515... ACT PROCEDURES Procedures for Requesting Records § 1515.9 Extending CEQ's time to respond. (a) In... request (§§ 1515.6(a) and 1515.8(d)) may be extended by the Council for not more than 10 working days...

40 CFR 1515.9 - Extending CEQ's time to respond.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Extending CEQ's time to respond. 1515... ACT PROCEDURES Procedures for Requesting Records § 1515.9 Extending CEQ's time to respond. (a) In... request (§§ 1515.6(a) and 1515.8(d)) may be extended by the Council for not more than 10 working days...

40 CFR 1515.9 - Extending CEQ's time to respond.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Extending CEQ's time to respond. 1515... ACT PROCEDURES Procedures for Requesting Records § 1515.9 Extending CEQ's time to respond. (a) In... request (§§ 1515.6(a) and 1515.8(d)) may be extended by the Council for not more than 10 working days...

40 CFR 1515.9 - Extending CEQ's time to respond.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Extending CEQ's time to respond. 1515... ACT PROCEDURES Procedures for Requesting Records § 1515.9 Extending CEQ's time to respond. (a) In... request (§§ 1515.6(a) and 1515.8(d)) may be extended by the Council for not more than 10 working days...

Relationship between cutoff frequency and accuracy in time-interval photon statistics applied to oscillating signals

NASA Astrophysics Data System (ADS)

Rebolledo, M. A.; Martinez-Betorz, J. A.

1989-04-01

In this paper the accuracy in the determination of the period of an oscillating signal, when obtained from the photon statistics time-interval probability, is studied as a function of the precision (the inverse of the cutoff frequency of the photon counting system) with which time intervals are measured. The results are obtained by means of an experiment with a square-wave signal, where the Fourier or square-wave transforms of the time-interval probability are measured. It is found that for values of the frequency of the signal near the cutoff frequency the errors in the period are small.

Method of high precision interval measurement in pulse laser ranging system

NASA Astrophysics Data System (ADS)

Wang, Zhen; Lv, Xin-yuan; Mao, Jin-jin; Liu, Wei; Yang, Dong

2013-09-01

Laser ranging is suitable for laser system, for it has the advantage of high measuring precision, fast measuring speed,no cooperative targets and strong resistance to electromagnetic interference,the measuremen of laser ranging is the key paremeters affecting the performance of the whole system.The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement, the principle structure of laser ranging system was introduced, and a method of high precision time interval measurement in pulse laser ranging system was established in this paper.Based on the analysis of the factors which affected the precision of range measure,the pulse rising edges discriminator was adopted to produce timing mark for the start-stop time discrimination,and the TDC-GP2 high precision interval measurement system based on TMS320F2812 DSP was designed to improve the measurement precision.Experimental results indicate that the time interval measurement method in this paper can obtain higher range accuracy. Compared with the traditional time interval measurement system,the method simplifies the system design and reduce the influence of bad weather conditions,furthermore,it satisfies the requirements of low costs and miniaturization.

Short-term load and wind power forecasting using neural network-based prediction intervals.

PubMed

Quan, Hao; Srinivasan, Dipti; Khosravi, Abbas

2014-02-01

Electrical power systems are evolving from today's centralized bulk systems to more decentralized systems. Penetrations of renewable energies, such as wind and solar power, significantly increase the level of uncertainty in power systems. Accurate load forecasting becomes more complex, yet more important for management of power systems. Traditional methods for generating point forecasts of load demands cannot properly handle uncertainties in system operations. To quantify potential uncertainties associated with forecasts, this paper implements a neural network (NN)-based method for the construction of prediction intervals (PIs). A newly introduced method, called lower upper bound estimation (LUBE), is applied and extended to develop PIs using NN models. A new problem formulation is proposed, which translates the primary multiobjective problem into a constrained single-objective problem. Compared with the cost function, this new formulation is closer to the primary problem and has fewer parameters. Particle swarm optimization (PSO) integrated with the mutation operator is used to solve the problem. Electrical demands from Singapore and New South Wales (Australia), as well as wind power generation from Capital Wind Farm, are used to validate the PSO-based LUBE method. Comparative results show that the proposed method can construct higher quality PIs for load and wind power generation forecasts in a short time.

Vestibular stimulation interferes with the dynamics of an internal representation of gravity.

PubMed

De Sá Teixeira, Nuno Alexandre; Hecht, Heiko; Diaz Artiles, Ana; Seyedmadani, Kimia; Sherwood, David P; Young, Laurence R

2017-11-01

The remembered vanishing location of a moving target has been found to be displaced downward in the direction of gravity (representational gravity) and more so with increasing retention intervals, suggesting that the visual spatial updating recruits an internal model of gravity. Despite being consistently linked with gravity, few inquiries have been made about the role of vestibular information in these trends. Previous experiments with static tilting of observers' bodies suggest that under conflicting cues between the idiotropic vector and vestibular signals, the dynamic drift in memory is reduced to a constant displacement along the body's main axis. The present experiment aims to replicate and extend these outcomes while keeping the observers' bodies unchanged in relation to physical gravity by varying the gravito-inertial acceleration using a short-radius centrifuge. Observers were shown, while accelerated to varying degrees, targets moving along several directions and were required to indicate the perceived vanishing location after a variable interval. Increases of the gravito-inertial force (up to 1.4G), orthogonal to the idiotropic vector, did not affect the direction of representational gravity, but significantly disrupted its time course. The role and functioning of an internal model of gravity for spatial perception and orientation are discussed in light of the results.

Discriminating signal from noise in the fossil record of early vertebrates reveals cryptic evolutionary history

PubMed Central

Sansom, Robert S.; Randle, Emma; Donoghue, Philip C. J.

2015-01-01

The fossil record of early vertebrates has been influential in elucidating the evolutionary assembly of the gnathostome bodyplan. Understanding of the timing and tempo of vertebrate innovations remains, however, mired in a literal reading of the fossil record. Early jawless vertebrates (ostracoderms) exhibit restriction to shallow-water environments. The distribution of their stratigraphic occurrences therefore reflects not only flux in diversity, but also secular variation in facies representation of the rock record. Using stratigraphic, phylogenetic and palaeoenvironmental data, we assessed the veracity of the fossil records of the jawless relatives of jawed vertebrates (Osteostraci, Galeaspida, Thelodonti, Heterostraci). Non-random models of fossil recovery potential using Palaeozoic sea-level changes were used to calculate confidence intervals of clade origins. These intervals extend the timescale for possible origins into the Upper Ordovician; these estimates ameliorate the long ghost lineages inferred for Osteostraci, Galeaspida and Heterostraci, given their known stratigraphic occurrences and stem–gnathostome phylogeny. Diversity changes through the Silurian and Devonian were found to lie within the expected limits predicted from estimates of fossil record quality indicating that it is geological, rather than biological factors, that are responsible for shifts in diversity. Environmental restriction also appears to belie ostracoderm extinction and demise rather than competition with jawed vertebrates. PMID:25520359

Relative impact of human leukocyte antigen mismatching and graft ischemic time after lung transplantation.

PubMed

Brugière, Olivier; Thabut, Gabriel; Suberbielle, Caroline; Reynaud-Gaubert, Martine; Thomas, Pascal; Pison, Christophe; Saint Raymond, Christel; Mornex, Jean-François; Bertocchi, Michèle; Dromer, Claire; Velly, Jean-François; Stern, Marc; Philippe, Bruno; Dauriat, Gaëlle; Biondi, Giuseppina; Castier, Yves; Fournier, Michel

2008-06-01

Recent data strongly suggest that human leukocyte antigen (HLA) mismatching has a negative impact on development of bronchiolitis obliterans syndrome (BOS) and survival after lung transplantation (LTx). Because HLA matching is sometimes achieved by extending ischemic time in other solid-organ transplantation models and ischemic time is a risk factor per se for death after LTx, we sought to compare the theoretical benefit of HLA matching with the negative impact of lengthened ischemic time. In this collaborative study we compared the relative impact of HLA mismatching and ischemic time on BOS and survival in 182 LTx recipients. Using multivariate analyses, we observed a lower incidence of BOS (hazard ratio [HR] = 1.70, 95% confidence interval [CI]: 1.1 to 2.7, p = 0.03) and enhanced survival (HR = 1.91, 95% CI: 1.24 to 2.92, p = 0.01) in patients with zero or one HLA-A mismatch compared with those having two HLA-A mismatches. This beneficial effect on survival was equivalent to a reduction of ischemic time of 168 minutes. We observed a reduced incidence of BOS and a better survival rate in patients well-matched at the HLA-A locus, associated with an opposite effect of an enhanced ischemic time. This suggests that graft ischemic time should be taken into account in future studies of prospective HLA matching in LTx.

Analysis and stochastic modelling of Intensity-Duration-Frequency relationship from 88 years of 10 min rainfall data in North Spain

NASA Astrophysics Data System (ADS)

Delgado, Oihane; Campo-Bescós, Miguel A.; López, J. Javier

2017-04-01

Frequently, when we are trying to solve certain hydrological engineering problems, it is often necessary to know rain intensity values related to a specific probability or return period, T. Based on analyses of extreme rainfall events at different time scale aggregation, we can deduce the relationships among Intensity-Duration-Frequency (IDF), that are widely used in hydraulic infrastructure design. However, the lack of long time series of rainfall intensities for smaller time periods, minutes or hours, leads to use mathematical expressions to characterize and extend these curves. One way to deduce them is through the development of synthetic rainfall time series generated from stochastic models, which is evaluated in this work. From recorded accumulated rainfall time series every 10 min in the pluviograph of Igueldo (San Sebastian, Spain) for the time period between 1927-2005, their homogeneity has been checked and possible statistically significant increasing or decreasing trends have also been shown. Subsequently, two models have been calibrated: Bartlett-Lewis and Markov chains models, which are based on the successions of storms, composed for a series of rainfall events, separated by a short interval of time each. Finally, synthetic ten-minute rainfall time series are generated, which allow to estimate detailed IDF curves and compare them with the estimated IDF based on the recorded data.

Investigations of timing during the schedule and reinforcement intervals with wheel-running reinforcement.

PubMed

Belke, Terry W; Christie-Fougere, Melissa M

2006-11-01

Across two experiments, a peak procedure was used to assess the timing of the onset and offset of an opportunity to run as a reinforcer. The first experiment investigated the effect of reinforcer duration on temporal discrimination of the onset of the reinforcement interval. Three male Wistar rats were exposed to fixed-interval (FI) 30-s schedules of wheel-running reinforcement and the duration of the opportunity to run was varied across values of 15, 30, and 60s. Each session consisted of 50 reinforcers and 10 probe trials. Results showed that as reinforcer duration increased, the percentage of postreinforcement pauses longer than the 30-s schedule interval increased. On probe trials, peak response rates occurred near the time of reinforcer delivery and peak times varied with reinforcer duration. In a second experiment, seven female Long-Evans rats were exposed to FI 30-s schedules leading to 30-s opportunities to run. Timing of the onset and offset of the reinforcement period was assessed by probe trials during the schedule interval and during the reinforcement interval in separate conditions. The results provided evidence of timing of the onset, but not the offset of the wheel-running reinforcement period. Further research is required to assess if timing occurs during a wheel-running reinforcement period.

High resolution digital delay timer

DOEpatents

Martin, Albert D.

1988-01-01

Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

Quantification of glutathione transverse relaxation time T2 using echo time extension with variable refocusing selectivity and symmetry in the human brain at 7 Tesla

NASA Astrophysics Data System (ADS)

Swanberg, Kelley M.; Prinsen, Hetty; Coman, Daniel; de Graaf, Robin A.; Juchem, Christoph

2018-05-01

Glutathione (GSH) is an endogenous antioxidant implicated in numerous biological processes, including those associated with multiple sclerosis, aging, and cancer. Spectral editing techniques have greatly facilitated the acquisition of glutathione signal in living humans via proton magnetic resonance spectroscopy, but signal quantification at 7 Tesla is still hampered by uncertainty about the glutathione transverse decay rate T2 relative to those of commonly employed quantitative references like N-acetyl aspartate (NAA), total creatine, or water. While the T2 of uncoupled singlets can be derived in a straightforward manner from exponential signal decay as a function of echo time, similar estimation of signal decay in GSH is complicated by a spin system that involves both weak and strong J-couplings as well as resonances that overlap those of several other metabolites and macromolecules. Here, we extend a previously published method for quantifying the T2 of GABA, a weakly coupled system, to quantify T2 of the strongly coupled spin system glutathione in the human brain at 7 Tesla. Using full density matrix simulation of glutathione signal behavior, we selected an array of eight optimized echo times between 72 and 322 ms for glutathione signal acquisition by J-difference editing (JDE). We varied the selectivity and symmetry parameters of the inversion pulses used for echo time extension to further optimize the intensity, simplicity, and distinctiveness of glutathione signals at chosen echo times. Pairs of selective adiabatic inversion pulses replaced nonselective pulses at three extended echo times, and symmetry of the time intervals between the two extension pulses was adjusted at one extended echo time to compensate for J-modulation, thereby resulting in appreciable signal-to-noise ratio and quantifiable signal shapes at all measured points. Glutathione signal across all echo times fit smooth monoexponential curves over ten scans of occipital cortex voxels in nine subjects. The T2 of glutathione was calculated to be 145.0 ± 20.1 ms (mean ± standard deviation); this result was robust within one standard deviation to changes in metabolite fitting baseline corrections and removal of individual data points on the signal decay curve. The measured T2 of NAA (222.1 ± 24.7 ms) and total creatine (153.0 ± 19.9 ms) were both higher than that calculated for GSH. Apparent glutathione concentration quantified relative to both reference metabolites increased by up to 32% and 6%, respectively, upon correction with calculated T2 values, emphasizing the importance of considering T2 relaxation differences in the spectroscopic measurement of these metabolites, especially at longer echo times.

Quantification of glutathione transverse relaxation time T2 using echo time extension with variable refocusing selectivity and symmetry in the human brain at 7 Tesla.

PubMed

Swanberg, Kelley M; Prinsen, Hetty; Coman, Daniel; de Graaf, Robin A; Juchem, Christoph

2018-05-01

Glutathione (GSH) is an endogenous antioxidant implicated in numerous biological processes, including those associated with multiple sclerosis, aging, and cancer. Spectral editing techniques have greatly facilitated the acquisition of glutathione signal in living humans via proton magnetic resonance spectroscopy, but signal quantification at 7 Tesla is still hampered by uncertainty about the glutathione transverse decay rate T 2 relative to those of commonly employed quantitative references like N-acetyl aspartate (NAA), total creatine, or water. While the T 2 of uncoupled singlets can be derived in a straightforward manner from exponential signal decay as a function of echo time, similar estimation of signal decay in GSH is complicated by a spin system that involves both weak and strong J-couplings as well as resonances that overlap those of several other metabolites and macromolecules. Here, we extend a previously published method for quantifying the T 2 of GABA, a weakly coupled system, to quantify T 2 of the strongly coupled spin system glutathione in the human brain at 7 Tesla. Using full density matrix simulation of glutathione signal behavior, we selected an array of eight optimized echo times between 72 and 322 ms for glutathione signal acquisition by J-difference editing (JDE). We varied the selectivity and symmetry parameters of the inversion pulses used for echo time extension to further optimize the intensity, simplicity, and distinctiveness of glutathione signals at chosen echo times. Pairs of selective adiabatic inversion pulses replaced nonselective pulses at three extended echo times, and symmetry of the time intervals between the two extension pulses was adjusted at one extended echo time to compensate for J-modulation, thereby resulting in appreciable signal-to-noise ratio and quantifiable signal shapes at all measured points. Glutathione signal across all echo times fit smooth monoexponential curves over ten scans of occipital cortex voxels in nine subjects. The T 2 of glutathione was calculated to be 145.0 ± 20.1 ms (mean ± standard deviation); this result was robust within one standard deviation to changes in metabolite fitting baseline corrections and removal of individual data points on the signal decay curve. The measured T 2 of NAA (222.1 ± 24.7 ms) and total creatine (153.0 ± 19.9 ms) were both higher than that calculated for GSH. Apparent glutathione concentration quantified relative to both reference metabolites increased by up to 32% and 6%, respectively, upon correction with calculated T 2 values, emphasizing the importance of considering T 2 relaxation differences in the spectroscopic measurement of these metabolites, especially at longer echo times. Copyright © 2018 Elsevier Inc. All rights reserved.

No Clear Association between Impaired Short-Term or Working Memory Storage and Time Reproduction Capacity in Adult ADHD Patients.

PubMed

Mette, Christian; Grabemann, Marco; Zimmermann, Marco; Strunz, Laura; Scherbaum, Norbert; Wiltfang, Jens; Kis, Bernhard

2015-01-01

Altered time reproduction is exhibited by patients with adult attention deficit hyperactivity disorder (ADHD). It remains unclear whether memory capacity influences the ability of adults with ADHD to reproduce time intervals. We conducted a behavioral study on 30 ADHD patients who were medicated with methylphenidate, 29 unmedicated adult ADHD patients and 32 healthy controls (HCs). We assessed time reproduction using six time intervals (1 s, 4 s, 6 s, 10 s, 24 s and 60 s) and assessed memory performance using the Wechsler memory scale. The patients with ADHD exhibited lower memory performance scores than the HCs. No significant differences in the raw scores for any of the time intervals (p > .05), with the exception of the variability at the short time intervals (1 s, 4 s and 6 s) (p < .01), were found between the groups. The overall analyses failed to reveal any significant correlations between time reproduction at any of the time intervals examined in the time reproduction task and working memory performance (p > .05). We detected no findings indicating that working memory might influence time reproduction in adult patients with ADHD. Therefore, further studies concerning time reproduction and memory capacity among adult patients with ADHD must be performed to verify and replicate the present findings.

Real-time eye motion correction in phase-resolved OCT angiography with tracking SLO

PubMed Central

Braaf, Boy; Vienola, Kari V.; Sheehy, Christy K.; Yang, Qiang; Vermeer, Koenraad A.; Tiruveedhula, Pavan; Arathorn, David W.; Roorda, Austin; de Boer, Johannes F.

2012-01-01

In phase-resolved OCT angiography blood flow is detected from phase changes in between A-scans that are obtained from the same location. In ophthalmology, this technique is vulnerable to eye motion. We address this problem by combining inter-B-scan phase-resolved OCT angiography with real-time eye tracking. A tracking scanning laser ophthalmoscope (TSLO) at 840 nm provided eye tracking functionality and was combined with a phase-stabilized optical frequency domain imaging (OFDI) system at 1040 nm. Real-time eye tracking corrected eye drift and prevented discontinuity artifacts from (micro)saccadic eye motion in OCT angiograms. This improved the OCT spot stability on the retina and consequently reduced the phase-noise, thereby enabling the detection of slower blood flows by extending the inter-B-scan time interval. In addition, eye tracking enabled the easy compounding of multiple data sets from the fovea of a healthy volunteer to create high-quality eye motion artifact-free angiograms. High-quality images are presented of two distinct layers of vasculature in the retina and the dense vasculature of the choroid. Additionally we present, for the first time, a phase-resolved OCT angiogram of the mesh-like network of the choriocapillaris containing typical pore openings. PMID:23304647