A Comparison of Momentary Time Sampling and Partial-Interval Recording for Assessment of Effects of Social Skills Training

ERIC Educational Resources Information Center

Radley, Keith C.; O'Handley, Roderick D.; Labrot, Zachary C.

2015-01-01

Assessment in social skills training often utilizes procedures such as partial-interval recording (PIR) and momentary time sampling (MTS) to estimate changes in duration in social engagements due to intervention. Although previous research suggests PIR to be more inaccurate than MTS in estimating levels of behavior, treatment analysis decisions…

Birth spacing and fertility limitation: a behavioral analysis of a nineteenth century frontier population.

PubMed

Anderton, D L; Bean, L L

1985-05-01

Our analysis of changing birth interval distributions over the course of a fertility transition from natural to controlled fertility has examined three closely related propositions. First, within both natural fertility populations (identified at the aggregate level) and cohorts following the onset of fertility limitation, we hypothesized that substantial groups of women with long birth intervals across the individually specified childbearing careers could be identified. That is, even during periods when fertility behavior at the aggregate level is consistent with a natural fertility regime, birth intervals at all parities are inversely related to completed family size. Our tabular analysis enables us to conclude that birth spacing patterns are parity dependent; there is stability in CEB-parity specific mean and birth interval variance over the entire transition. Our evidence does not suggest that the early group of women limiting and spacing births was marked by infecundity. Secondly, the transition appears to be associated with an increasingly larger proportion of women shifting to the same spacing schedules associated with smaller families in earlier cohorts. Thirdly, variations in birth spacing by age of marriage indicate that changes in birth intervals over time are at least indirectly associated with age of marriage, indicating an additional compositional effect. The evidence we have presented on spacing behavior does not negate the argument that parity-dependent stopping behavior was a powerful factor in the fertility transition. Our data also provide evidence of attempts to truncate childbearing. Specifically, the smaller the completed family size, the longer the ultimate birth interval; and ultimate birth intervals increase across cohorts controlling CEB and parity. But spacing appears to represent an additional strategy of fertility limitation. Thus, it may be necessary to distinguish spacing and stopping behavior if one wishes to clarify behavioral patterns within a population (Edlefsen, 1981; Friedlander et al., 1980; Rodriguez and Hobcraft, 1980). Because fertility transition theories imply increased attempts to limit family sizes, it is important to examine differential behavior within subgroups achieving different family sizes. It is this level of analysis which we have attempted to achieve in utilizing parity-specific birth intervals controlled by children ever born.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparison of linear, skewed-linear, and proportional hazard models for the analysis of lambing interval in Ripollesa ewes.

PubMed

Casellas, J; Bach, R

2012-06-01

Lambing interval is a relevant reproductive indicator for sheep populations under continuous mating systems, although there is a shortage of selection programs accounting for this trait in the sheep industry. Both the historical assumption of small genetic background and its unorthodox distribution pattern have limited its implementation as a breeding objective. In this manuscript, statistical performances of 3 alternative parametrizations [i.e., symmetric Gaussian mixed linear (GML) model, skew-Gaussian mixed linear (SGML) model, and piecewise Weibull proportional hazard (PWPH) model] have been compared to elucidate the preferred methodology to handle lambing interval data. More specifically, flock-by-flock analyses were performed on 31,986 lambing interval records (257.3 ± 0.2 d) from 6 purebred Ripollesa flocks. Model performances were compared in terms of deviance information criterion (DIC) and Bayes factor (BF). For all flocks, PWPH models were clearly preferred; they generated a reduction of 1,900 or more DIC units and provided BF estimates larger than 100 (i.e., PWPH models against linear models). These differences were reduced when comparing PWPH models with different number of change points for the baseline hazard function. In 4 flocks, only 2 change points were required to minimize the DIC, whereas 4 and 6 change points were needed for the 2 remaining flocks. These differences demonstrated a remarkable degree of heterogeneity across sheep flocks that must be properly accounted for in genetic evaluation models to avoid statistical biases and suboptimal genetic trends. Within this context, all 6 Ripollesa flocks revealed substantial genetic background for lambing interval with heritabilities ranging between 0.13 and 0.19. This study provides the first evidence of the suitability of PWPH models for lambing interval analysis, clearly discarding previous parametrizations focused on mixed linear models.

Wavelet analysis of the Laser Doppler signal to assess skin perfusion.

PubMed

Bagno, Andrea; Martini, Romeo

2015-01-01

The hemodynamics of skin microcirculation can be clinically assessed by means of Laser Doppler Fluxmetry. Laser Doppler signals show periodic oscillations because of fluctuations of microvascular perfusion (flowmotion), which are sustained by contractions and relaxations of arteriolar walls rhythmically changing vessels diameter (vasomotion). The wavelet analysis applied to Laser Doppler signals displays six characteristic frequency intervals, from 0.005 to 2 Hz. Each interval is assigned to a specific structure of the cardiovascular system: heart, respiration, vascular myocites, sympathetic terminations, and endothelial cells (dependent and independent on nitric oxide). Therefore, mechanisms of skin perfusion can be investigated through wavelet analysis. In the present work, examples of methods and results of wavelet analysis applied to Laser Doppler signals are reported. Laser Doppler signals were acquired in two groups of patients to check possible changes in vascular activities, before and after occlusive reactive hyperaemia, and before and after revascularization.

Effect of Missing Inter-Beat Interval Data on Heart Rate Variability Analysis Using Wrist-Worn Wearables.

PubMed

Baek, Hyun Jae; Shin, JaeWook

2017-08-15

Most of the wrist-worn devices on the market provide a continuous heart rate measurement function using photoplethysmography, but have not yet provided a function to measure the continuous heart rate variability (HRV) using beat-to-beat pulse interval. The reason for such is the difficulty of measuring a continuous pulse interval during movement using a wearable device because of the nature of photoplethysmography, which is susceptible to motion noise. This study investigated the effect of missing heart beat interval data on the HRV analysis in cases where pulse interval cannot be measured because of movement noise. First, we performed simulations by randomly removing data from the RR interval of the electrocardiogram measured from 39 subjects and observed the changes of the relative and normalized errors for the HRV parameters according to the total length of the missing heart beat interval data. Second, we measured the pulse interval from 20 subjects using a wrist-worn device for 24 h and observed the error value for the missing pulse interval data caused by the movement during actual daily life. The experimental results showed that mean NN and RMSSD were the most robust for the missing heart beat interval data among all the parameters in the time and frequency domains. Most of the pulse interval data could not be obtained during daily life. In other words, the sample number was too small for spectral analysis because of the long missing duration. Therefore, the frequency domain parameters often could not be calculated, except for the sleep state with little motion. The errors of the HRV parameters were proportional to the missing data duration in the presence of missing heart beat interval data. Based on the results of this study, the maximum missing duration for acceptable errors for each parameter is recommended for use when the HRV analysis is performed on a wrist-worn device.

Quantitative analysis of ground penetrating radar data in the Mu Us Sandland

NASA Astrophysics Data System (ADS)

Fu, Tianyang; Tan, Lihua; Wu, Yongqiu; Wen, Yanglei; Li, Dawei; Duan, Jinlong

2018-06-01

Ground penetrating radar (GPR), which can reveal the sedimentary structure and development process of dunes, is widely used to evaluate aeolian landforms. The interpretations for GPR profiles are mostly based on qualitative descriptions of geometric features of the radar reflections. This research quantitatively analyzed the waveform parameter characteristics of different radar units by extracting the amplitude and time interval parameters of GPR data in the Mu Us Sandland in China, and then identified and interpreted different sedimentary structures. The results showed that different types of radar units had specific waveform parameter characteristics. The main waveform parameter characteristics of sand dune radar facies and sandstone radar facies included low amplitudes and wide ranges of time intervals, ranging from 0 to 0.25 and 4 to 33 ns respectively, and the mean amplitudes changed gradually with time intervals. The amplitude distribution curves of various sand dune radar facies were similar as unimodal distributions. The radar surfaces showed high amplitudes with time intervals concentrated in high-value areas, ranging from 0.08 to 0.61 and 9 to 34 ns respectively, and the mean amplitudes changed drastically with time intervals. The amplitude and time interval values of lacustrine radar facies were between that of sand dune radar facies and radar surfaces, ranging from 0.08 to 0.29 and 11 to 30 ns respectively, and the mean amplitude and time interval curve was approximately trapezoidal. The quantitative extraction and analysis of GPR reflections could help distinguish various radar units and provide evidence for identifying sedimentary structure in aeolian landforms.

Pneumatic testing in 45-degree-inclined boreholes in ash-flow tuff near Superior, Arizona

USGS Publications Warehouse

LeCain, G.D.

1995-01-01

Matrix permeability values determined by single-hole pneumatic testing in nonfractured ash-flow tuff ranged from 5.1 to 20.3 * 1046 m2 (meters squared), depending on the gas-injection rate and analysis method used. Results from the single-hole tests showed several significant correlations between permeability and injection rate and between permeability and test order. Fracture permeability values determined by cross-hole pneumatic testing in fractured ash-flow tuff ranged from 0.81 to 3.49 * 1044 m2, depending on injection rate and analysis method used. Results from the cross-hole tests monitor intervals showed no significant correlation between permeability and injection rate; however, results from the injection interval showed a significant correlation between injection rate and permeability. Porosity estimates from the 'cross-hole testing range from 0.8 to 2.0 percent. The maximum temperature change associated with the pneumatic testing was 1.2'(2 measured in the injection interval during cross-hole testing. The maximum temperature change in the guard and monitor intervals was O.Ip C. The maximum error introduced into the permeability values due to temperature fluctuations is approximately 4 percent. Data from temperature monitoring in the borehole indicated a positive correlation between the temperature decrease in the injection interval during recovery testing and the gas-injection rate. The thermocouple psychrometers indicated that water vapor was condensing in the boreholes during testing. The psychrometers in the guard and monitor intervals detected the drier injected gas as an increase in the dry bulb reading. The relative humidity in the test intervals was always higher than the upper measurement limit of the psychrometers. Although the installation of the packer system may have altered the water balance of the borehole, the gas-injection testing resulted in minimal or no changes in the borehole relative humidity.

Effect of alectinib on cardiac electrophysiology: results from intensive electrocardiogram monitoring from the pivotal phase II NP28761 and NP28673 studies.

PubMed

Morcos, Peter N; Bogman, Katrijn; Hubeaux, Stanislas; Sturm-Pellanda, Carolina; Ruf, Thorsten; Bordogna, Walter; Golding, Sophie; Zeaiter, Ali; Abt, Markus; Balas, Bogdana

2017-03-01

Alectinib, a central nervous system (CNS)-active ALK inhibitor, has demonstrated efficacy and safety in ALK+ non-small-cell lung cancer that has progressed following crizotinib treatment. Other ALK inhibitors have shown concentration-dependent QTc prolongation and treatment-related bradycardia. Therefore, this analysis evaluated alectinib safety in terms of electrophysiologic parameters. Intensive triplicate centrally read electrocardiogram (ECG) and matched pharmacokinetic data were collected across two alectinib single-arm trials. Analysis of QTcF included central tendency analysis [mean changes from baseline with one-sided upper 95% confidence intervals (CIs)], categorical analyses, and relationship between change in QTcF and alectinib plasma concentrations. Alectinib effects on other ECG parameters (heart rate, PR interval and QRS duration) were also evaluated. Alectinib did not cause a clinically relevant change in QTcF. The maximum mean QTcF change from baseline was 5.3 ms observed pre-dose at week 2. The upper one-sided 95% CI was <10 ms at all time points. There was no relevant relationship between change in QTcF and alectinib plasma concentrations. Alectinib treatment resulted in a generally asymptomatic exposure-dependent decrease in mean heart rate of ~11 to 13 beats per minute at week 2. No clinically relevant effects were seen on other ECG parameters. Approximately 5% of patients reported cardiac adverse events of bradycardia or sinus bradycardia; however, these were all grade 1-2. Alectinib does not prolong the QTc interval or cause changes in cardiac function to a clinically relevant extent, with the exception of a decrease in heart rate which was generally asymptomatic.

Contraction frequency after administration of misoprostol in obese versus nonobese women.

PubMed

Stefely, Erin; Warshak, Carri R

2018-04-30

To examine impact of obesity on contraction frequency following misoprostol. Our hypothesis is that an increased volume of distribution reduces the bioavailability of misoprostol and may be an explanation for reduced efficacy. We examined the contraction frequency as a surrogate marker for bioavailability of misoprostol. We compared the rate of contractions at five time intervals in 313 subjects: prior to administration, and at four intervals post administration. We compared number of contractions in obese versus nonobese. As a planned secondary analysis, we then compared the rate of change in contractions per hour at four time intervals: a repeated measures analysis to compare the rate of change in contractions per hour over the 5-hour window controlling for race (White versus non-White) and parity (primiparous versus multiparous). General linear model and repeated measures analysis were conducted to report the parameter estimates, least square means, difference of least square means, and p values. Nonobese women presented with more contractions at baseline, 7 ± 5 versus 4 ± 5 c/h, p < .001. At all four time intervals after misoprostol administration obese women had fewer contractions per hour. The rate of change in contraction frequency after administration found obese women had a lower rate of increase in contraction frequency over the course of all four hours. We found a least squares means estimate (c/h): first hour (-0.87), p = .08, second hour (-2.43), p = .01, third hour (-1.80), p = .96, and fourth hour (-2.98), p = .007. Obese women have a lower rate of contractions per hour at baseline and at four intervals after misoprostol administration. In addition, the rate of change in the increase in contractions/hour also was reduced in obese women versus nonobese women. This suggests a lower bioavailability of misoprostol in women with a larger volume of distribution which would likely impact the efficacy of misoprostol in obese women when given the same dose of misoprostol. It is unknown if higher misoprostol dosing would increase efficacy of misoprostol in obese women.

Characterization of QT and RR interval series during acute myocardial ischemia by means of recurrence quantification analysis.

PubMed

Peng, Yi; Sun, Zhongwei

2011-01-01

This study is aimed to investigate the nonlinear dynamic properties of the fluctuations in ventricular repolarization, heart rate and their correlation during acute myocardial ischemia. From 13 ECG records in long-term ST-T database, 170 ischemic episodes were selected with the duration of 34 s to 23 min 18 s, and two 5-min episodes immediately before and after each ischemic episode as non-ischemic ones for comparison. QT interval (QTI) and RR interval (RRI) were extracted and the ectopic beats were removed. Recurrence quantification analysis (RQA) was performed on QTI and RRI series, respectively, and cross recurrence quantification analysis (CRQA) on paired normalized QTI and RRI series. Wilcoxon signed-rank test was used for statistical analysis. Results revealed that the RQA indexes for QTI and HRI series had the same changing trend during ischemia with more significantly changed indexes in QTI series. In the CRQA, indexes related to the vertical and horizontal structures in recurrence plot significantly increased, representing decreased dependency of QTI on RRI. Both QTI and RRI series showed reduced complexity during ischemia with higher sensitivity in ventricular repolarization. The weakened coupling between QTI and RRI suggests the decreased influence of sinoatrial node on QTI modulation during ischemia.

4D seismic monitoring of the miscible CO2 flood of Hall-Gurney Field, Kansas, U.S

USGS Publications Warehouse

Raef, A.E.; Miller, R.D.; Byrnes, A.P.; Harrison, W.E.

2004-01-01

A cost-effective, highly repeatable, 4D-optimized, single-pattern/patch seismic data-acquisition approach with several 3D data sets was used to evaluate the feasibility of imaging changes associated with the " water alternated with gas" (WAG) stage. By incorporating noninversion-based seismic-attribute analysis, the time and cost of processing and interpreting the data were reduced. A 24-ms-thick EOR-CO 2 injection interval-using an average instantaneous frequency attribute (AIF) was targeted. Changes in amplitude response related to decrease in velocity from pore-fluid replacement within this time interval were found to be lower relative to background values than in AIF analysis. Carefully color-balanced AIF-attribute maps established the overall area affected by the injected EOR-CO2.

On ``Overestimation-free Computational Version of Interval Analysis''

NASA Astrophysics Data System (ADS)

Popova, Evgenija D.

2013-10-01

The transformation of interval parameters into trigonometric functions, proposed in Int. J. Comput. Meth. Eng. Sci. Mech., vol. 13, pp. 319-328 (2012), is not motivated in comparison to the infinitely many equivalent algebraic transformations. The conclusions about the efficacy of the methodology used are based on incorrect comparisons between solutions of different problems. We show theoretically, and in the examples considered in the commented article, that changing the number of the parameters in a system of linear algebraic equations may change the initial problem, respectively, its solution set. We also correct various misunderstandings and bugs that appear in the article noted above.

Analysis of wind bias change with respect to time at Cape Kennedy, Florida, and Vandenberg AFB, California

NASA Technical Reports Server (NTRS)

Adelfang, S. I.

1978-01-01

A statistical analysis is presented of the temporal variability of wind vectors at 1 km altitude intervals from 0 to 27 km altitude after applying a digital filter to the original wind profile data sample.

Modeling the Trajectory of Analgesic Demand Over Time After Total Knee Arthroplasty Using the Latent Curve Analysis.

PubMed

Lo, Po-Han; Tsou, Mei-Yung; Chang, Kuang-Yi

2015-09-01

Patient-controlled epidural analgesia (PCEA) is commonly used for pain relief after total knee arthroplasty (TKA). This study aimed to model the trajectory of analgesic demand over time after TKA and explore its influential factors using latent curve analysis. Data were retrospectively collected from 916 patients receiving unilateral or bilateral TKA and postoperative PCEA. PCEA demands during 12-hour intervals for 48 hours were directly retrieved from infusion pumps. Potentially influential factors of PCEA demand, including age, height, weight, body mass index, sex, and infusion pump settings, were also collected. A latent curve analysis with 2 latent variables, the intercept (baseline) and slope (trend), was applied to model the changes in PCEA demand over time. The effects of influential factors on these 2 latent variables were estimated to examine how these factors interacted with time to alter the trajectory of PCEA demand over time. On average, the difference in analgesic demand between the first and second 12-hour intervals was only 15% of that between the first and third 12-hour intervals. No significant difference in PCEA demand was noted between the third and fourth 12-hour intervals. Aging tended to decrease the baseline PCEA demand but body mass index and infusion rate were positively correlated with the baseline. Only sex significantly affected the trend parameter and male individuals tended to have a smoother decreasing trend of analgesic demands over time. Patients receiving bilateral procedures did not consume more analgesics than their unilateral counterparts. Goodness of fit analysis indicated acceptable model fit to the observed data. Latent curve analysis provided valuable information about how analgesic demand after TKA changed over time and how patient characteristics affected its trajectory.

Weight gain and nutritional efficacy in anorexia nervosa.

PubMed

Dempsey, D T; Crosby, L O; Pertschuk, M J; Feurer, I D; Buzby, G P; Mullen, J L

1984-02-01

To evaluate the usefulness of interval weight change in assessing nutritional support efficacy, we studied four anorexia nervosa patients (52% ideal body weight) requiring long-term total parenteral nutrition (TPN) for 63 +/- 18 days. Fluid and electrolyte deficits were corrected before the initiation of nutritional support. Resting energy expenditure was measured before the initiation of TPN and weekly thereafter, using indirect calorimetry. Daily caloric expenditure was estimated at 1.1 X resting energy expenditure, based on previous studies of continuous heart rate monitoring in this patient population. Daily excess calories were calculated as caloric intake minus caloric expenditure. Each patient was weighed daily and linear regression analysis (excess calories versus weight change) was performed for individual patients and the group over intervals of varying length. There was no individual or group correlation between excess calories and weight gain on a daily or weekly interval basis. Cumulative weight changes over the long-term course of TPN correlated significantly with cumulative excess calories for each patient and the whole group (r = +0.82, p less than 0.01). The excess calories required to gain a kilogram body weight ranged from 5569 to 15619 kcal/kg with a mean of 9768. Cumulative long-term weight changes during nutritional repletion in anorexia nervosa are meaningful indicators of caloric balance, but short interval weight changes (daily, weekly) are not. The caloric cost of weight gain is variable in this population.

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.

Correlated and uncorrelated heart rate fluctuations during relaxing visualization

NASA Astrophysics Data System (ADS)

Papasimakis, N.; Pallikari, F.

2010-05-01

The heart rate variability (HRV) of healthy subjects practicing relaxing visualization is studied by use of three multiscale analysis techniques: the detrended fluctuation analysis (DFA), the entropy in natural time (ENT) and the average wavelet (AWC) coefficient. The scaling exponent of normal interbeat interval increments exhibits characteristics of the presence of long-range correlations. During relaxing visualization the HRV dynamics change in the sense that two new features emerge independent of each other: a respiration-induced periodicity that often dominates the HRV at short scales (<40 interbeat intervals) and the decrease of the scaling exponent at longer scales (40-512 interbeat intervals). In certain cases, the scaling exponent during relaxing visualization indicates the breakdown of long-range correlations. These characteristics have been previously seen in the HRV dynamics during non-REM sleep.

Aerobic Interval vs. Continuous Training in Patients with Coronary Artery Disease or Heart Failure: An Updated Systematic Review and Meta-Analysis with a Focus on Secondary Outcomes.

PubMed

Pattyn, Nele; Beulque, Randy; Cornelissen, Véronique

2018-05-01

In a previous meta-analysis including nine trials comparing aerobic interval training with aerobic continuous training in patients with coronary artery disease, we found a significant difference in peak oxygen uptake favoring aerobic interval training. The objective of this study was to (1) update the original meta-analysis focussing on peak oxygen uptake and (2) evaluate the effect on secondary outcomes. We conducted a systematic review with a meta-analysis by searching PubMed and SPORTDiscus databases up to March 2017. We included randomized trials comparing aerobic interval training and aerobic continuous training in patients with coronary artery disease or chronic heart failure. The primary outcome was change in peak oxygen uptake. Secondary outcomes included cardiorespiratory parameters, cardiovascular risk factors, cardiac and vascular function, and quality of life. Twenty-four papers were identified (n = 1080; mean age 60.7 ± 10.7 years). Aerobic interval training resulted in a higher increase in peak oxygen uptake compared with aerobic continuous training in all patients (1.40 mL/kg/min; p < 0.001), and in the subgroups of patients with coronary artery disease (1.25 mL/kg/min; p = 0.001) and patients with chronic heart failure with reduced ejection fraction (1.46 mL/kg/min; p = 0.03). Moreover, a larger increase of the first ventilatory threshold and peak heart rate was observed after aerobic interval training in all patients. Other cardiorespiratory parameters, cardiovascular risk factors, and quality of life were equally affected. This meta-analysis adds further evidence to the clinically significant larger increase in peak oxygen uptake following aerobic interval training vs. aerobic continuous training in patients with coronary artery disease and chronic heart failure. More well-designed randomized controlled trials are needed to establish the safety of aerobic interval training and the sustainability of the training response over longer periods.

Monitoring land use/land cover transformations from 1945 to 2007 in two peri-urban mountainous areas of Athens metropolitan area, Greece.

PubMed

Mallinis, Giorgos; Koutsias, Nikos; Arianoutsou, Margarita

2014-08-15

The aims of this study were to map and analyze land use/land cover transitions and landscape changes in the Parnitha and Penteli mountains, which surround the Athens metropolitan area of Attica, Greece over a period of 62 years. In order to quantify the changes between land categories through time, we computed the transition matrices for three distinct periods (1945-1960, 1960-1996, and 1996-2007), on the basis of available aerial photographs used to create multi-temporal maps. We identified systematic and stationary transitions with multi-level intensity analysis. Forest areas in Parnitha remained the dominant class of land cover throughout the 62 years studied, while transitional woodlands and shrublands were the main classes involved in LULC transitions. Conversely, in Penteli, transitional woodlands, along with shrublands, dominated the study site. The annual rate of change was faster in the first and third time intervals, compared to the second (1960-1996) time interval, in both study areas. The category level analysis results indicated that in both sites annual crops avoided to gain while discontinuous urban fabric avoided to lose areas. At the transition level of analysis, similarities as well as distinct differences existed between the two areas. In both sites the gaining pattern of permanent crops with respect to annual crops and the gain of forest with respect to transitional woodland/shrublands were stationary across the three time intervals. Overall, we identified more systematic transitions and stationary processes in Penteli. We discussed these LULC changes and associated them with human interference (activity) and other major socio-economic developments that were simultaneously occurring in the area. The different patterns of change of the areas, despite their geographical proximity, throughout the period of analysis imply that site-specific studies are needed in order to comprehensively assess the driving forces and develop models of landscape transformation in Mediterranean areas. Copyright © 2014 Elsevier B.V. All rights reserved.

Baseline response rates affect resistance to change.

PubMed

Kuroda, Toshikazu; Cook, James E; Lattal, Kennon A

2018-01-01

The effect of response rates on resistance to change, measured as resistance to extinction, was examined in two experiments. In Experiment 1, responding in transition from a variable-ratio schedule and its yoked-interval counterpart to extinction was compared with pigeons. Following training on a multiple variable-ratio yoked-interval schedule of reinforcement, in which response rates were higher in the former component, reinforcement was removed from both components during a single extended extinction session. Resistance to extinction in the yoked-interval component was always either greater or equal to that in the variable-ratio component. In Experiment 2, resistance to extinction was compared for two groups of rats that exhibited either high or low response rates when maintained on identical variable-interval schedules. Resistance to extinction was greater for the lower-response-rate group. These results suggest that baseline response rate can contribute to resistance to change. Such effects, however, can only be revealed when baseline response rate and reinforcement rate are disentangled (Experiments 1 and 2) from the more usual circumstance where the two covary. Furthermore, they are more cleanly revealed when the programmed contingencies controlling high and low response rates are identical, as in Experiment 2. © 2017 Society for the Experimental Analysis of Behavior.

Analysis of vector wind change with respect to time for Vandenberg Air Force Base, California

NASA Technical Reports Server (NTRS)

Adelfang, S. I.

1978-01-01

A statistical analysis of the temporal variability of wind vectors at 1 km altitude intervals from 0 to 27 km altitude taken from a 10-year data sample of twice-daily rawinsode wind measurements over Vandenberg Air Force Base, California is presented.

High Resolution ECG for Evaluation of QT Interval Variability during Exposure to Acute Hypoxia

NASA Technical Reports Server (NTRS)

Zupet, P.; Finderle, Z.; Schlegel, Todd T.; Starc, V.

2010-01-01

Ventricular repolarization instability as quantified by the index of QT interval variability (QTVI) is one of the best predictors for risk of malignant ventricular arrhythmias and sudden cardiac death. Because it is difficult to appropriately monitor early signs of organ dysfunction at high altitude, we investigated whether high resolution advanced ECG (HR-ECG) analysis might be helpful as a non-invasive and easy-to-use tool for evaluating the risk of cardiac arrhythmias during exposure to acute hypoxia. 19 non-acclimatized healthy trained alpinists (age 37, 8 plus or minus 4,7 years) participated in the study. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position breathing room air and then after breathing 12.5% oxygen for 30 min. For beat-to-beat RR and QT variability, the program of Starc was utilized to derive standard time domain measures such as root mean square of the successive interval difference (rMSSD) of RRV and QTV, the corrected QT interval (QTc) and the QTVI in lead II. Changes were evaluated with paired-samples t-test with p-values less than 0.05 considered statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with p = 0.000 and p = 0.005, respectively. Significant increases were found in both the rMSSDQT and the QTVI in lead II, with p = 0.002 and p = 0.003, respectively. There was no change in QTc interval length (p = non significant). QT variability parameters may be useful for evaluating changes in ventricular repolarization caused by hypoxia. These changes might be driven by increases in sympathetic nervous system activity at ventricular level.

Altered fractal dynamics of gait: reduced stride-interval correlations with aging and Huntington's disease

NASA Technical Reports Server (NTRS)

Hausdorff, J. M.; Mitchell, S. L.; Firtion, R.; Peng, C. K.; Cudkowicz, M. E.; Wei, J. Y.; Goldberger, A. L.

1997-01-01

Fluctuations in the duration of the gait cycle (the stride interval) display fractal dynamics and long-range correlations in healthy young adults. We hypothesized that these stride-interval correlations would be altered by changes in neurological function associated with aging and certain disease states. To test this hypothesis, we compared the stride-interval time series of 1) healthy elderly subjects and young controls and of 2) subjects with Huntington's disease and healthy controls. Using detrended fluctuation analysis we computed alpha, a measure of the degree to which one stride interval is correlated with previous and subsequent intervals over different time scales. The scaling exponent alpha was significantly lower in elderly subjects compared with young subjects (elderly: 0.68 +/- 0.14; young: 0.87 +/- 0.15; P < 0.003). The scaling exponent alpha was also smaller in the subjects with Huntington's disease compared with disease-free controls (Huntington's disease: 0.60 +/- 0.24; controls: 0.88 +/-0.17; P < 0.005). Moreover, alpha was linearly related to degree of functional impairment in subjects with Huntington's disease (r = 0.78, P < 0.0005). These findings demonstrate that strike-interval fluctuations are more random (i.e., less correlated) in elderly subjects and in subjects with Huntington's disease. Abnormal alterations in the fractal properties of gait dynamics are apparently associated with changes in central nervous system control.

Using fire return interval departure (FRID) analysis to map spatial and temporal changes in fire frequency on national forest lands in California

Treesearch

Hugh D. Safford; Kip M. Van de Water

2014-01-01

In California, fire regimes and related ecosystem processes have been altered by land use practices associated with Euro-American settlement, and climate warming is exacerbating the magnitude and effects of these changes. Because of changing environmental baselines, restoration of narrowly defined historical conditions may no longer be an attainable or sustainable long...

Assessment of Reliable Change Using 95% Credible Intervals for the Differences in Proportions: A Statistical Analysis for Case-Study Methodology

ERIC Educational Resources Information Center

Unicomb, Rachael; Colyvas, Kim; Harrison, Elisabeth; Hewat, Sally

2015-01-01

Purpose: Case-study methodology studying change is often used in the field of speech-language pathology, but it can be criticized for not being statistically robust. Yet with the heterogeneous nature of many communication disorders, case studies allow clinicians and researchers to closely observe and report on change. Such information is valuable…

Alpha-lipoic acid (ALA) as a supplementation for weight loss: results from a meta-analysis of randomized controlled trials.

PubMed

Kucukgoncu, S; Zhou, E; Lucas, K B; Tek, C

2017-05-01

Obesity is associated with significant morbidity and mortality rates. Even modest weight loss may be associated with health benefits. Alpha-lipoic acid (ALA) is a naturally occurring antioxidant. Studies have suggested anti-obesity properties of ALA; however, results are inconsistent. The purpose of this study is to conduct a meta-analysis of the effect of ALA on weight and body mass index (BMI). A comprehensive, systematic literature search identified 10 articles on randomized, double-blind, placebo-controlled studies involving ALA. We conducted a meta-analysis of mean weight and BMI change differences between ALA and placebo treatment groups. Alpha-lipoic acid treatment coincided with a statistically significant 1.27 kg (confidence interval = 0.25 to 2.29) greater mean weight loss compared with the placebo group. A significant overall mean BMI difference of -0.43 kg/ m 2 (confidence interval = -0.82 to -0.03) was found between the ALA and placebo groups. Meta-regression analysis showed no significance in ALA dose on BMI and weight changes. Study duration significantly affected BMI change, but not weight change. Alpha-lipoic acid treatment showed small, yet significant short-term weight loss compared with placebo. Further research is needed to examine the effect of different doses and the long-term benefits of ALA on weight management. © 2017 World Obesity Federation.

When Human Walking is a Random Walk

NASA Astrophysics Data System (ADS)

Hausdorff, J. M.

1998-03-01

The complex, hierarchical locomotor system normally does a remarkable job of controlling an inherently unstable, multi-joint system. Nevertheless, the stride interval --- the duration of a gait cycle --- fluctuates from one stride to the next, even under stationary conditions. We used random walk analysis to study the dynamical properties of these fluctuations under normal conditions and how they change with disease and aging. Random walk analysis of the stride-to-stride fluctuations of healthy, young adult men surprisingly reveals a self-similar pattern: fluctuations at one time scale are statistically similar to those at multiple other time scales (Hausdorff et al, J Appl Phsyiol, 1995). To study the stability of this fractal property, we analyzed data obtained from healthy subjects who walked for 1 hour at their usual pace, as well as at slower and faster speeds. The stride interval fluctuations exhibited long-range correlations with power-law decay for up to a thousand strides at all three walking rates. In contrast, during metronomically-paced walking, these long-range correlations disappeared; variations in the stride interval were uncorrelated and non-fractal (Hausdorff et al, J Appl Phsyiol, 1996). To gain insight into the mechanism(s) responsible for this fractal property, we examined the effects of aging and neurological impairment. Using detrended fluctuation analysis (DFA), we computed α, a measure of the degree to which one stride interval is correlated with previous and subsequent intervals over different time scales. α was significantly lower in healthy elderly subjects compared to young adults (p < .003) and in subjects with Huntington's disease, a neuro-degenerative disorder of the central nervous system, compared to disease-free controls (p < 0.005) (Hausdorff et al, J Appl Phsyiol, 1997). α was also significantly related to degree of functional impairment in subjects with Huntington's disease (r=0.78). Recently, we have observed that just as there are changes with α during aging, there also changes with development. Apparently, the fractal scaling of walking does not become mature until children are eleven years old. Conclusions: The fractal dynamics of spontaneous stride interval fluctuations are normally quite robust and are apparently intrinsic to the healthy adult locomotor system. However, alterations in this fractal scaling property are associated with impairment in central nervous system control, aging and neural development.

Climate change lessons from a warm world

USGS Publications Warehouse

Dowsett, Harry J.

2010-01-01

In the early 1970’s to early 1980’s Soviet climatologists were making comparisons to past intervals of warmth in the geologic record and suggesting that these intervals could be possible analogs for 21st century “greenhouse” conditions. Some saw regional warming as a benefit to the Soviet Union and made comments along the lines of “Set fire to the coal mines!” These sentiments were alarming to some, and the United States Geological Survey (USGS) leadership thought they could provide a more quantitative analysis of the data the Soviets were using for the most recent of these warm intervals, the Early Pliocene.

Methods of measurement signal acquisition from the rotational flow meter for frequency analysis

NASA Astrophysics Data System (ADS)

Świsulski, Dariusz; Hanus, Robert; Zych, Marcin; Petryka, Leszek

One of the simplest and commonly used instruments for measuring the flow of homogeneous substances is the rotational flow meter. The main part of such a device is a rotor (vane or screw) rotating at a speed which is the function of the fluid or gas flow rate. A pulse signal with a frequency proportional to the speed of the rotor is obtained at the sensor output. For measurements in dynamic conditions, a variable interval between pulses prohibits the analysis of the measuring signal. Therefore, the authors of the article developed a method involving the determination of measured values on the basis of the last inter-pulse interval preceding the moment designated by the timing generator. For larger changes of the measured value at a predetermined time, the value can be determined by means of extrapolation of the two adjacent interpulse ranges, assuming a linear change in the flow. The proposed methods allow analysis which requires constant spacing between measurements, allowing for an analysis of the dynamics of changes in the test flow, eg. using a Fourier transform. To present the advantages of these methods simulations of flow measurement were carried out with a DRH-1140 rotor flow meter from the company Kobold.

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.

Visualization and Quantitative Analysis of Crack-Tip Plastic Zone in Pure Nickel

NASA Astrophysics Data System (ADS)

Kelton, Randall; Sola, Jalal Fathi; Meletis, Efstathios I.; Huang, Haiying

2018-05-01

Changes in surface morphology have long been thought to be associated with crack propagation in metallic materials. We have studied areal surface texture changes around crack tips in an attempt to understand the correlations between surface texture changes and crack growth behavior. Detailed profiling of the fatigue sample surface was carried out at short fatigue intervals. An image processing algorithm was developed to calculate the surface texture changes. Quantitative analysis of the crack-tip plastic zone, crack-arrested sites near triple points, and large surface texture changes associated with crack release from arrested locations was carried out. The results indicate that surface texture imaging enables visualization of the development of plastic deformation around a crack tip. Quantitative analysis of the surface texture changes reveals the effects of local microstructures on the crack growth behavior.

A review of statistical issues with progression-free survival as an interval-censored time-to-event endpoint.

PubMed

Sun, Xing; Li, Xiaoyun; Chen, Cong; Song, Yang

2013-01-01

Frequent rise of interval-censored time-to-event data in randomized clinical trials (e.g., progression-free survival [PFS] in oncology) challenges statistical researchers in the pharmaceutical industry in various ways. These challenges exist in both trial design and data analysis. Conventional statistical methods treating intervals as fixed points, which are generally practiced by pharmaceutical industry, sometimes yield inferior or even flawed analysis results in extreme cases for interval-censored data. In this article, we examine the limitation of these standard methods under typical clinical trial settings and further review and compare several existing nonparametric likelihood-based methods for interval-censored data, methods that are more sophisticated but robust. Trial design issues involved with interval-censored data comprise another topic to be explored in this article. Unlike right-censored survival data, expected sample size or power for a trial with interval-censored data relies heavily on the parametric distribution of the baseline survival function as well as the frequency of assessments. There can be substantial power loss in trials with interval-censored data if the assessments are very infrequent. Such an additional dependency controverts many fundamental assumptions and principles in conventional survival trial designs, especially the group sequential design (e.g., the concept of information fraction). In this article, we discuss these fundamental changes and available tools to work around their impacts. Although progression-free survival is often used as a discussion point in the article, the general conclusions are equally applicable to other interval-censored time-to-event endpoints.

Nationwide Multicenter Reference Interval Study for 28 Common Biochemical Analytes in China.

PubMed

Xia, Liangyu; Chen, Ming; Liu, Min; Tao, Zhihua; Li, Shijun; Wang, Liang; Cheng, Xinqi; Qin, Xuzhen; Han, Jianhua; Li, Pengchang; Hou, Li'an; Yu, Songlin; Ichihara, Kiyoshi; Qiu, Ling

2016-03-01

A nationwide multicenter study was conducted in the China to explore sources of variation of reference values and establish reference intervals for 28 common biochemical analytes, as a part of the International Federation of Clinical Chemistry and Laboratory Medicine, Committee on Reference Intervals and Decision Limits (IFCC/C-RIDL) global study on reference values. A total of 3148 apparently healthy volunteers were recruited in 6 cities covering a wide area in China. Blood samples were tested in 2 central laboratories using Beckman Coulter AU5800 chemistry analyzers. Certified reference materials and value-assigned serum panel were used for standardization of test results. Multiple regression analysis was performed to explore sources of variation. Need for partition of reference intervals was evaluated based on 3-level nested ANOVA. After secondary exclusion using the latent abnormal values exclusion method, reference intervals were derived by a parametric method using the modified Box-Cox formula. Test results of 20 analytes were made traceable to reference measurement procedures. By the ANOVA, significant sex-related and age-related differences were observed in 12 and 12 analytes, respectively. A small regional difference was observed in the results for albumin, glucose, and sodium. Multiple regression analysis revealed BMI-related changes in results of 9 analytes for man and 6 for woman. Reference intervals of 28 analytes were computed with 17 analytes partitioned by sex and/or age. In conclusion, reference intervals of 28 common chemistry analytes applicable to Chinese Han population were established by use of the latest methodology. Reference intervals of 20 analytes traceable to reference measurement procedures can be used as common reference intervals, whereas others can be used as the assay system-specific reference intervals in China.

Nationwide Multicenter Reference Interval Study for 28 Common Biochemical Analytes in China

PubMed Central

Xia, Liangyu; Chen, Ming; Liu, Min; Tao, Zhihua; Li, Shijun; Wang, Liang; Cheng, Xinqi; Qin, Xuzhen; Han, Jianhua; Li, Pengchang; Hou, Li’an; Yu, Songlin; Ichihara, Kiyoshi; Qiu, Ling

2016-01-01

Abstract A nationwide multicenter study was conducted in the China to explore sources of variation of reference values and establish reference intervals for 28 common biochemical analytes, as a part of the International Federation of Clinical Chemistry and Laboratory Medicine, Committee on Reference Intervals and Decision Limits (IFCC/C-RIDL) global study on reference values. A total of 3148 apparently healthy volunteers were recruited in 6 cities covering a wide area in China. Blood samples were tested in 2 central laboratories using Beckman Coulter AU5800 chemistry analyzers. Certified reference materials and value-assigned serum panel were used for standardization of test results. Multiple regression analysis was performed to explore sources of variation. Need for partition of reference intervals was evaluated based on 3-level nested ANOVA. After secondary exclusion using the latent abnormal values exclusion method, reference intervals were derived by a parametric method using the modified Box–Cox formula. Test results of 20 analytes were made traceable to reference measurement procedures. By the ANOVA, significant sex-related and age-related differences were observed in 12 and 12 analytes, respectively. A small regional difference was observed in the results for albumin, glucose, and sodium. Multiple regression analysis revealed BMI-related changes in results of 9 analytes for man and 6 for woman. Reference intervals of 28 analytes were computed with 17 analytes partitioned by sex and/or age. In conclusion, reference intervals of 28 common chemistry analytes applicable to Chinese Han population were established by use of the latest methodology. Reference intervals of 20 analytes traceable to reference measurement procedures can be used as common reference intervals, whereas others can be used as the assay system-specific reference intervals in China. PMID:26945390

Analyzing long-term changes in vegetation with geographic information system and remotely sensed data

Treesearch

Louis. R. Iverson; Paul. G. Risser; Paul. G. Risser

1987-01-01

Geographic information systems and remote sensing techniques are powerful tools in the analysis of long-term changes in vegetation and land use, especially because spatial information from two or more time intervals can be compared more readily than by manual methods. A primary restriction is the paucity of data that has been digitized from earlier periods. The...

Sediment color and reflectance record from Ocean Drilling Program Hole 625B, Gulf of Mexico (marine isotope stage 5 interval)

USGS Publications Warehouse

Dowsett, Harry J.

1999-01-01

Analysis of climate indicators from the North Atlantic, California Margin, and ice cores from Greenland suggest millennial scale climate variability is a component of earth's climate system during the last interglacial period (marine oxygen isotope stage 5). The USGS is involved in a survey of high resolution marine records covering the last interglacial period (MIS 5) to further document the variability of climate and assess the rate at which climate can change during warm intervals. The Gulf of Mexico (GOM) is an attractive area for analysis of climate variability and rapid change. Changes in the Mississippi River Basin presumably are translated to the GOM via the river and its effect on sediment distribution and type. Likewise, the summer monsoon in the southwestern US is driven by strong southerly winds. These winds may produce upwelling in the GOM which will be recorded in the sedimentary record. Several areas of high accumulation rate have been identified in the GOM. Ocean Drilling Program (ODP) Site 625 appears to meet the criteria of having a well preserved carbonate record and accumulation rate capable of discerning millennial scale changes.

Finding Intervals of Abrupt Change in Earth Science Data

NASA Astrophysics Data System (ADS)

Zhou, X.; Shekhar, S.; Liess, S.

2011-12-01

In earth science data (e.g., climate data), it is often observed that a persistently abrupt change in value occurs in a certain time-period or spatial interval. For example, abrupt climate change is defined as an unusually large shift of precipitation, temperature, etc, that occurs during a relatively short time period. A similar pattern can also be found in geographical space, representing a sharp transition of the environment (e.g., vegetation between different ecological zones). Identifying such intervals of change from earth science datasets is a crucial step for understanding and attributing the underlying phenomenon. However, inconsistencies in these noisy datasets can obstruct the major change trend, and more importantly can complicate the search of the beginning and end points of the interval of change. Also, the large volume of data makes it challenging to process the dataset reasonably fast. In earth science data (e.g., climate data), it is often observed that a persistently abrupt change in value occurs in a certain time-period or spatial interval. For example, abrupt climate change is defined as an unusually large shift of precipitation, temperature, etc, that occurs during a relatively short time period. A similar change pattern can also be found in geographical space, representing a sharp transition of the environment (e.g., vegetation between different ecological zones). Identifying such intervals of change from earth science datasets is a crucial step for understanding and attributing the underlying phenomenon. However, inconsistencies in these noisy datasets can obstruct the major change trend, and more importantly can complicate the search of the beginning and end points of the interval of change. Also, the large volume of data makes it challenging to process the dataset fast. In this work, we analyze earth science data using a novel, automated data mining approach to identify spatial/temporal intervals of persistent, abrupt change. We first propose a statistical model to quantitatively evaluate the change abruptness and persistence in an interval. Then we design an algorithm to exhaustively examine all the intervals using this model. Intervals passing a threshold test will be kept as final results. We evaluate the proposed method with the Climate Research Unit (CRU) precipitation data, whereby we focus on the Sahel rainfall index. Results show that this method can find periods of persistent and abrupt value changes with different temporal scales. We also further optimize the algorithm using a smart strategy, which always examines longer intervals before its subsets. By doing this, we reduce the computational cost to only one third of that of the original algorithm for the above test case. More significantly, the optimized algorithm is also proven to scale up well with data volume and number of changes. Particularly, it achieves better performance when dealing with longer change intervals.

Are physical activity interventions for healthy inactive adults effective in promoting behavior change and maintenance, and which behavior change techniques are effective? A systematic review and meta-analysis.

PubMed

Howlett, Neil; Trivedi, Daksha; Troop, Nicholas A; Chater, Angel Marie

2018-02-28

Physical inactivity and sedentary behavior relate to poor health outcomes independently. Healthy inactive adults are a key target population for prevention. This systematic review and meta-analysis aimed to evaluate the effectiveness of physical activity and/or sedentary behavior interventions, measured postintervention (behavior change) and at follow-up (behavior change maintenance), to identify behavior change techniques (BCT) within, and report on fidelity. Included studies were randomized controlled trials, targeting healthy inactive adults, aiming to change physical activity and/or sedentary behavior, with a minimum postintervention follow-up of 6 months, using 16 databases from 1990. Two reviewers independently coded risk of bias, the "Template for Intervention Description and Replication" (TIDieR) checklist, and BCTs. Twenty-six studies were included; 16 pooled for meta-analysis. Physical activity interventions were effective at changing behavior (d = 0.32, 95% confidence intervals = 0.16-0.48, n = 2,346) and maintaining behavior change after 6 months or more (d = 0.21, 95% confidence intervals = 0.12-0.30, n = 2,190). Sedentary behavior interventions (n = 2) were not effective. At postintervention, physical activity intervention effectiveness was associated with the BCTs "Biofeedback," "Demonstration of the behavior," "Behavior practice/rehearsal," and "Graded tasks." At follow-up, effectiveness was associated with using "Action planning," "Instruction on how to perform the behavior," "Prompts/cues," "Behavior practice/rehearsal," "Graded tasks," and "Self-reward." Fidelity was only documented in one study. Good evidence was found for behavior change maintenance effects in healthy inactive adults, and underlying BCTs. This review provides translational evidence to improve research, intervention design, and service delivery in physical activity interventions, while highlighting the lack of fidelity measurement.

Longitudinal brain white matter alterations in minimal hepatic encephalopathy before and after liver transplantation.

PubMed

Lin, Wei-Che; Chou, Kun-Hsien; Chen, Chao-Long; Chen, Hsiu-Ling; Lu, Cheng-Hsien; Li, Shau-Hsuan; Huang, Chu-Chung; Lin, Ching-Po; Cheng, Yu-Fan

2014-01-01

Cerebral edema is the common pathogenic mechanism for cognitive impairment in minimal hepatic encephalopathy. Whether complete reversibility of brain edema, cognitive deficits, and their associated imaging can be achieved after liver transplantation remains an open question. To characterize white matter integrity before and after liver transplantation in patients with minimal hepatic encephalopathy, multiple diffusivity indices acquired via diffusion tensor imaging was applied. Twenty-eight patients and thirty age- and sex-matched healthy volunteers were included. Multiple diffusivity indices were obtained from diffusion tensor images, including mean diffusivity, fractional anisotropy, axial diffusivity and radial diffusivity. The assessment was repeated 6-12 month after transplantation. Differences in white matter integrity between groups, as well as longitudinal changes, were evaluated using tract-based spatial statistical analysis. Correlation analyses were performed to identify first scan before transplantation and interval changes among the neuropsychiatric tests, clinical laboratory tests, and diffusion tensor imaging indices. After transplantation, decreased water diffusivity without fractional anisotropy change indicating reversible cerebral edema was found in the left anterior cingulate, claustrum, postcentral gyrus, and right corpus callosum. However, a progressive decrease in fractional anisotropy and an increase in radial diffusivity suggesting demyelination were noted in temporal lobe. Improved pre-transplantation albumin levels and interval changes were associated with better recoveries of diffusion tensor imaging indices. Improvements in interval diffusion tensor imaging indices in the right postcentral gyrus were correlated with visuospatial function score correction. In conclusion, longitudinal voxel-wise analysis of multiple diffusion tensor imaging indices demonstrated different white matter changes in minimal hepatic encephalopathy patients. Transplantation improved extracellular cerebral edema and the results of associated cognition tests. However, white matter demyelination may advance in temporal lobe.

Climate change increases the probability of heavy rains in Northern England/Southern Scotland like those of storm Desmond—a real-time event attribution revisited

NASA Astrophysics Data System (ADS)

Otto, Friederike E. L.; van der Wiel, Karin; van Oldenborgh, Geert Jan; Philip, Sjoukje; Kew, Sarah F.; Uhe, Peter; Cullen, Heidi

2018-02-01

On 4-6 December 2015, storm Desmond caused very heavy rainfall in Northern England and Southern Scotland which led to widespread flooding. A week after the event we provided an initial assessment of the influence of anthropogenic climate change on the likelihood of one-day precipitation events averaged over an area encompassing Northern England and Southern Scotland using data and methods available immediately after the event occurred. The analysis was based on three independent methods of extreme event attribution: historical observed trends, coupled climate model simulations and a large ensemble of regional model simulations. All three methods agreed that the effect of climate change was positive, making precipitation events like this about 40% more likely, with a provisional 2.5%-97.5% confidence interval of 5%-80%. Here we revisit the assessment using more station data, an additional monthly event definition, a second global climate model and regional model simulations of winter 2015/16. The overall result of the analysis is similar to the real-time analysis with a best estimate of a 59% increase in event frequency, but a larger confidence interval that does include no change. It is important to highlight that the observational data in the additional monthly analysis does not only represent the rainfall associated with storm Desmond but also that of storms Eve and Frank occurring towards the end of the month.

Active ankle motion may result in changes to the talofibular interval in individuals with chronic ankle instability and ankle sprain copers: a preliminary study.

PubMed

Croy, Theodore; Cosby, Nicole L; Hertel, Jay

2013-08-01

Alterations in talocrural joint arthrokinematics related to repositioning of the talus or fibula following ankle sprain have been reported in radiological and clinical studies. It is unclear if these changes can result from normal active ankle motion. The study objective was to determine if active movement created changes in the sagittal plane talofibular interval in ankles with a history of lateral ankle sprain and instability. Three subject groups [control (n = 17), ankle sprain copers (n = 20), and chronic ankle instability (n = 20)] underwent ultrasound imaging of the anterolateral ankle gutter to identify the lateral malleolus and talus over three trials. Between trials, subjects actively plantar and dorsiflexed the ankle three times. The sagittal plane talofibular interval was assessed by measuring the anteroposterior distance (mm) between the lateral malleolus and talus from an ultrasound image. Between group and trial differences were analyzed with repeated measures analysis of variance and post-hoc t-tests. Fifty-seven subjects participated. A significant group-by-trial interaction was observed (F4,108 = 3.5; P = 0.009). The talofibular interval was increased in both copers [2.4±3.6 mm; 95% confidence interval (CI): 0.73-4.1; P = 0.007] and chronic ankle instability (4.1±4.6 mm; 95% CI: 1.9-6.2; P = 0.001) at trial 3 while no changes were observed in control ankle talar position (0.06±2.8mm; 95% CI: -1.5-1.4; P = 0.93). The talofibular interval increased only in subjects with a history of lateral ankle sprain with large clinical effect sizes observed. These findings suggest that an alteration in the position of the talus or fibula occurred with non-weight bearing sagittal plane motion. These findings may have diagnostic and therapeutic implications for manual therapists.

Active ankle motion may result in changes to the talofibular interval in individuals with chronic ankle instability and ankle sprain copers: a preliminary study

PubMed Central

Croy, Theodore; Cosby, Nicole L; Hertel, Jay

2013-01-01

Introduction: Alterations in talocrural joint arthrokinematics related to repositioning of the talus or fibula following ankle sprain have been reported in radiological and clinical studies. It is unclear if these changes can result from normal active ankle motion. The study objective was to determine if active movement created changes in the sagittal plane talofibular interval in ankles with a history of lateral ankle sprain and instability. Methods: Three subject groups [control (n = 17), ankle sprain copers (n = 20), and chronic ankle instability (n = 20)] underwent ultrasound imaging of the anterolateral ankle gutter to identify the lateral malleolus and talus over three trials. Between trials, subjects actively plantar and dorsiflexed the ankle three times. The sagittal plane talofibular interval was assessed by measuring the anteroposterior distance (mm) between the lateral malleolus and talus from an ultrasound image. Between group and trial differences were analyzed with repeated measures analysis of variance and post-hoc t-tests. Results: Fifty-seven subjects participated. A significant group-by-trial interaction was observed (F4,108 = 3.5; P = 0.009). The talofibular interval was increased in both copers [2.4±3.6 mm; 95% confidence interval (CI): 0.73–4.1; P = 0.007] and chronic ankle instability (4.1±4.6 mm; 95% CI: 1.9–6.2; P = 0.001) at trial 3 while no changes were observed in control ankle talar position (0.06±2.8mm; 95% CI: −1.5–1.4; P = 0.93). Discussion: The talofibular interval increased only in subjects with a history of lateral ankle sprain with large clinical effect sizes observed. These findings suggest that an alteration in the position of the talus or fibula occurred with non-weight bearing sagittal plane motion. These findings may have diagnostic and therapeutic implications for manual therapists. PMID:24421623

Sonographic Characteristics and Interval Changes of Subacute Thyroiditis.

PubMed

Lee, Yoo Jin; Kim, Dong Wook

2016-08-01

This study aimed to assess the sonographic characteristics and interval changes of subacute thyroiditis using follow-up sonography. From January 2008 to December 2014, 85 patients with clinically suspected subacute thyroiditis underwent sonographic examinations by a single radiologist. Subacute thyroiditis was confirmed on the basis of the clinical, sonographic, and cytohistopathologic findings. On the initial and follow-up sonograms, the individual sonographic findings and interval changes were retrospectively investigated by the same radiologist. According to the sonographic configuration, subacute thyroiditis lesions were categorized as nodular or non-nodular. The interval changes in the lesions were classified as follows: "disappeared," "decreased," "increased," "eventually smaller," "eventually larger," or "no interval change." Subacute thyroiditis was confirmed in 64 of the 85 patients. In these 64 patients, nodular (n = 39) and non-nodular (n = 35) lesions were found; 10 patients had both nodular and non-nodular lesions. Of the 64 patients, 41 underwent sonographic follow-up. In both nodular and non-nodular lesions, the common interval changes included disappeared, decreased, and eventually smaller patterns. Although the increased pattern was found only in 4 nodular lesions, there was no significant difference in the interval changes between nodular and non-nodular lesions. On follow-up sonography, a new lesion was detected in 6 patients. The prevalence rate of nodular subacute thyroiditis lesions on sonography was high, and the interval changes in the lesions were variable.

Temporal structure in the light response of relay cells in the dorsal lateral geniculate nucleus of the cat.

PubMed Central

Funke, K; Wörgötter, F

1995-01-01

1. The spike interval pattern during the light responses of 155 on- and 81 off-centre cells of the dorsal lateral geniculate nucleus (LGN) was studied in anaesthetized and paralysed cats by the use of a novel analysis. Temporally localized interval distributions were computed from a 100 ms time window, which was shifted along the time axis in 10 ms steps, resulting in a 90% overlap between two adjacent windows. For each step the interval distribution was computed inside the time window with 1 ms resolution, and plotted as a greyscale-coded pixel line orthogonal to the time axis. For visual stimulation, light or dark spots of different size and contrast were presented with different background illumination levels. 2. Two characteristic interval patterns were observed during the sustained response component of the cells. Mainly on-cells (77%) responded with multimodal interval distributions, resulting in elongated 'bands' in the 2-dimensional time window plots. In similar situations, the interval distributions for most (71%) off-cells were rather wide and featureless. In those cases where interval bands (i.e. multimodal interval distributions) were observed for off-cells (14%), they were always much wider than for the on-cells. This difference between the on- and off-cell population was independent of the background illumination and the contrast of the stimulus. Y on-cells also tended to produce wider interval bands than X on-cells. 3. For most stimulation situations the first interval band was centred around 6-9 ms, which has been called the fundamental interval; higher order bands are multiples thereof. The fundamental interval shifted towards larger sizes with decreasing stimulus contrast. Increasing stimulus size, on the other hand, resulted in a redistribution of the intervals into higher order bands, while at the same time the location of the fundamental interval remained largely unaffected. This was interpreted as an effect of the increasing surround inhibition at the geniculate level, by which individual retinal EPSPs were cancelled. A changing level of adaptation can result in a mixed shift/redistribution effect because of the changing stimulus contrast and changing level of tonic inhibition. 4. The occurrence of interval bands is not directly related to the shape of the autocorrelation function, which can be flat, weakly oscillatory or strongly oscillatory, regardless of the interval band pattern. 5. A simple computer model was devised to account for the observed cell behaviour. The model is highly robust against parameter variations.(ABSTRACT TRUNCATED AT 400 WORDS) Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 15 PMID:7562612

Thin-plate spline analysis of mandibular growth.

PubMed

Franchi, L; Baccetti, T; McNamara, J A

2001-04-01

The analysis of mandibular growth changes around the pubertal spurt in humans has several important implications for the diagnosis and orthopedic correction of skeletal disharmonies. The purpose of this study was to evaluate mandibular shape and size growth changes around the pubertal spurt in a longitudinal sample of subjects with normal occlusion by means of an appropriate morphometric technique (thin-plate spline analysis). Ten mandibular landmarks were identified on lateral cephalograms of 29 subjects at 6 different developmental phases. The 6 phases corresponded to 6 different maturational stages in cervical vertebrae during accelerative and decelerative phases of the pubertal growth curve of the mandible. Differences in shape between average mandibular configurations at the 6 developmental stages were visualized by means of thin-plate spline analysis and subjected to permutation test. Centroid size was used as the measure of the geometric size of each mandibular specimen. Differences in size at the 6 developmental phases were tested statistically. The results of graphical analysis indicated a statistically significant change in mandibular shape only for the growth interval from stage 3 to stage 4 in cervical vertebral maturation. Significant increases in centroid size were found at all developmental phases, with evidence of a prepubertal minimum and of a pubertal maximum. The existence of a pubertal peak in human mandibular growth, therefore, is confirmed by thin-plate spline analysis. Significant morphological changes in the mandible during the growth interval from stage 3 to stage 4 in cervical vertebral maturation may be described as an upward-forward direction of condylar growth determining an overall "shrinkage" of the mandibular configuration along the measurement of total mandibular length. This biological mechanism is particularly efficient in compensating for major increments in mandibular size at the adolescent spurt.

Isoelectric focusing analysis of antibody clonotype changes occurring during immune responses using immobilized pH gradients

NASA Technical Reports Server (NTRS)

Knisley, Keith A.; Rodkey, L. Scott

1988-01-01

Serum was collected from rabbits at 2-day intervals following a single injection with tetanus toxoid or at weekly intervals following multiple injections with Micrococcus lysodeikticus cell walls. These sera were analyzed for the presence of individual clonotypes of specific antitetanus or antimicrococcal antibodies by isoelectric focusing in immobilized pH gradients with added carrier ampholytes followed by affinity immunoblotting. The affinity immunoblots obtained clearly defined both the rapid disappearance and late appearance of distinct subsets of antibody clonotypes during the response. These data demonstrate the application of affinity immunoblotting combined with immobilized pH gradients for detecting the subtle changes in specific antibody clonotype patterns which occur during an immune response.

Indonesian Throughflow drove Australian climate from humid Pliocene to arid Pleistocene

NASA Astrophysics Data System (ADS)

Christensen, B. A.; Renema, W.; Henderiks, J.; De Vleeschouwer, D.; Groeneveld, J.; Castañeda, I. S.; Reuning, L.; Bogus, K.; Auer, G.; Ishiwa, T.; McHugh, C.; Gallagher, S. J.; Fulthorpe, C.; Expedition 356 Scientists, I.

2016-12-01

Our understanding of the onset of aridity in Australia and associated mechanisms is limited by the availability of long, continuous climate archives, particularly for the NW shelf in the Pliocene. Five sites were cored and logged on IODP Expedition 356, western Australian margin. Analysis of the natural gamma ray (NGR) suite of downhole logs, provide insights to the timing and rate of climate change. NGR data provide an outstanding tool to assess continental humidity (K%) and aridity (Th/K, Uppm); interpretations are supported with clay mineral data. We show progressive constriction of the Indonesian Throughflow (ITF) and the emerging Maritime Continent drove Australian climate to become drier and more variable. We identify 3 intervals of latest Miocene through early Pleistocene change: sudden onset of humidity at 5.5 Ma (Humid Interval), followed by decreased humidity (Transition Interval) and establishment of the NW dust pathway (Arid Interval) at 2.3 Ma. The Humid Interval is associated with the Western Pacific Warm Pool (WPWP) expansion west to the South China Sea and higher Indian Ocean SSTs. Our study of the NW region confirms wetter climates ringed the arid center during the early Pliocene. Reduced moisture availability began at 3.3 Ma, coincident with cooling in the WPWP and elsewhere, global atmospheric circulation constriction and Indian Ocean subsurface freshening and cooling, a direct response to ITF constriction. Greatest aridity and the onset of the modern dust pathway, documented in Th/K and Uppm logs beginning 2.3 Ma, is coincident with orbitally- controlled climatic change, and reorganization of Indian Ocean circulation. Our data indicate Australian climate is driven by tectonic and oceanographic changes in the ITF. Such changes altered regional atmospheric moisture transport and Indian Ocean circulation patterns and led to a shift from Pacific to Indian Ocean influence on theNW Australian climate, well after the intensification of northern hemisphere glaciation. We conclude that the Maritime Continent is the switchboard modulating teleconnections between monsoonal and glacial climate systems.

Identifying and separating the effects of practice and of cognitive ageing during a large longitudinal study of elderly community residents.

PubMed

Rabbitt, P; Diggle, P; Smith, D; Holland, F; Mc Innes, L

2001-01-01

In protracted longitudinal studies of cognitive changes in old age volunteers must be repeatedly tested. Even with intervals of several years between assessment, this raises the possibility that improvements due to practice mask other changes. This problem is much more acute in brief studies of cognitive changes associated with progressive pathologies such as Alzheimer's disease or the effects of clinical interventions. Both types of study also encounter problems of selective dropout of frail and less able individuals leaving relatively 'elite' survivors. An analysis of data from repeated testing at 2-3 years intervals on the AH4 (1) intelligence test is presented to illustrate how a random effects model can be used to identify and disassociate age-related changes and practice effects at the population level, after effects of selective dropout and of background demographical variables have been taken into consideration. This analysis also provides some new, substantive empirical findings. Age-related changes are relatively slight between 49 and 70 years but much more marked between 70 and 80 years. Even with assessment points, several years apart the population average effect of practice is large relative to that of age-related change. Variation between individuals increases as samples age, providing the first clear evidence from a longitudinal study for marked individual differences in trajectories of cognitive ageing.

A hierarchical model for estimating change in American Woodcock populations

USGS Publications Warehouse

Sauer, J.R.; Link, W.A.; Kendall, W.L.; Kelley, J.R.; Niven, D.K.

2008-01-01

The Singing-Ground Survey (SGS) is a primary source of information on population change for American woodcock (Scolopax minor). We analyzed the SGS using a hierarchical log-linear model and compared the estimates of change and annual indices of abundance to a route regression analysis of SGS data. We also grouped SGS routes into Bird Conservation Regions (BCRs) and estimated population change and annual indices using BCRs within states and provinces as strata. Based on the hierarchical model?based estimates, we concluded that woodcock populations were declining in North America between 1968 and 2006 (trend = -0.9%/yr, 95% credible interval: -1.2, -0.5). Singing-Ground Survey results are generally similar between analytical approaches, but the hierarchical model has several important advantages over the route regression. Hierarchical models better accommodate changes in survey efficiency over time and space by treating strata, years, and observers as random effects in the context of a log-linear model, providing trend estimates that are derived directly from the annual indices. We also conducted a hierarchical model analysis of woodcock data from the Christmas Bird Count and the North American Breeding Bird Survey. All surveys showed general consistency in patterns of population change, but the SGS had the shortest credible intervals. We suggest that population management and conservation planning for woodcock involving interpretation of the SGS use estimates provided by the hierarchical model.

Theoretical implications of quantitative properties of interval timing and probability estimation in mouse and rat.

PubMed

Kheifets, Aaron; Freestone, David; Gallistel, C R

2017-07-01

In three experiments with mice ( Mus musculus ) and rats (Rattus norvigicus), we used a switch paradigm to measure quantitative properties of the interval-timing mechanism. We found that: 1) Rodents adjusted the precision of their timed switches in response to changes in the interval between the short and long feed latencies (the temporal goalposts). 2) The variability in the timing of the switch response was reduced or unchanged in the face of large trial-to-trial random variability in the short and long feed latencies. 3) The adjustment in the distribution of switch latencies in response to changes in the relative frequency of short and long trials was sensitive to the asymmetry in the Kullback-Leibler divergence. The three results suggest that durations are represented with adjustable precision, that they are timed by multiple timers, and that there is a trial-by-trial (episodic) record of feed latencies in memory. © 2017 Society for the Experimental Analysis of Behavior.

Stroke preparedness in children: translating knowledge into behavioral intent: a systematic review and meta-analysis.

PubMed

Ottawa, Cassandra; Sposato, Luciano A; Nabbouh, Fadl; Saposnik, Gustavo

2015-10-01

If translated into behavioral intent, improving stroke knowledge may potentially impact on better outcomes. Children are an attractive target population since they can drive familial behavioral changes. However, the impact of interventions on stroke knowledge among children is unclear. We performed a systematic review and meta-analysis to investigate whether educational interventions targeting children improve stroke knowledge and lead to behavioral changes. We searched Ovid, PubMed, and Embase between January 2000 and December 2014. We included studies written in English reporting the number of children aged 6-15 years undergoing educational interventions on stroke and providing the results for baseline and early and late postintervention tests. We compared the proportion of correct answers between baseline, early, and late responses for two endpoints: knowledge and behavioral intent. Of the initial 58 articles found, we included nine that met the inclusion criteria. Compared with baseline tests (51·7%, 95% confidence interval 40·9-62·4), there was improvement in stroke knowledge in early (74·0%, 95% confidence interval 64·4-82·5, P = 0·002) and late (67·3%, 95% confidence interval 55·4-78·2, P = 0·027) responses. There was improvement in the early (92·1%, 95% confidence interval 86·0-96·6, P < 0·001) and late (83·9%, 95% confidence interval 73·5-92·1, P = 0·001) responses for behavioral intent compared with the baseline assessment (63·8%, 95% confidence interval 53·5-73·4). Children are a potentially attractive target population for improvement in stroke knowledge and behavioral intent, both in the short and long term. Our findings may support the implementation of large-scale stroke educational initiatives targeting children. © 2015 World Stroke Organization.

The effect of sampling rate on observed statistics in a correlated random walk

PubMed Central

Rosser, G.; Fletcher, A. G.; Maini, P. K.; Baker, R. E.

2013-01-01

Tracking the movement of individual cells or animals can provide important information about their motile behaviour, with key examples including migrating birds, foraging mammals and bacterial chemotaxis. In many experimental protocols, observations are recorded with a fixed sampling interval and the continuous underlying motion is approximated as a series of discrete steps. The size of the sampling interval significantly affects the tracking measurements, the statistics computed from observed trajectories, and the inferences drawn. Despite the widespread use of tracking data to investigate motile behaviour, many open questions remain about these effects. We use a correlated random walk model to study the variation with sampling interval of two key quantities of interest: apparent speed and angle change. Two variants of the model are considered, in which reorientations occur instantaneously and with a stationary pause, respectively. We employ stochastic simulations to study the effect of sampling on the distributions of apparent speeds and angle changes, and present novel mathematical analysis in the case of rapid sampling. Our investigation elucidates the complex nature of sampling effects for sampling intervals ranging over many orders of magnitude. Results show that inclusion of a stationary phase significantly alters the observed distributions of both quantities. PMID:23740484

The Isolation of Motivational, Motoric, and Schedule Effects on Operant Performance: A Modeling Approach

PubMed Central

Brackney, Ryan J; Cheung, Timothy H. C; Neisewander, Janet L; Sanabria, Federico

2011-01-01

Dissociating motoric and motivational effects of pharmacological manipulations on operant behavior is a substantial challenge. To address this problem, we applied a response-bout analysis to data from rats trained to lever press for sucrose on variable-interval (VI) schedules of reinforcement. Motoric, motivational, and schedule factors (effort requirement, deprivation level, and schedule requirements, respectively) were manipulated. Bout analysis found that interresponse times (IRTs) were described by a mixture of two exponential distributions, one characterizing IRTs within response bouts, another characterizing intervals between bouts. Increasing effort requirement lengthened the shortest IRT (the refractory period between responses). Adding a ratio requirement increased the length and density of response bouts. Both manipulations also decreased the bout-initiation rate. In contrast, food deprivation only increased the bout-initiation rate. Changes in the distribution of IRTs over time showed that responses during extinction were also emitted in bouts, and that the decrease in response rate was primarily due to progressively longer intervals between bouts. Taken together, these results suggest that changes in the refractory period indicate motoric effects, whereas selective alterations in bout initiation rate indicate incentive-motivational effects. These findings support the use of response-bout analyses to identify the influence of pharmacological manipulations on processes underlying operant performance. PMID:21765544

Pharmacokinetic and pharmacodynamic model for analysis of adalimumab administered for Crohn's disease.

PubMed

Kimura, Koji; Yoshida, Atsushi; Takayanagi, Risa; Yamada, Yasuhiko

2018-05-23

Adalimumab (ADA) is used as a therapeutic agent for Crohn's disease (CD). Although that dosage regimen has been established through clinical trial experience, it has not been analyzed theoretically. In the present study, we analyzed of sequential changes of the Crohn's disease activity index (CDAI) after repeated administrations of ADA using a pharmacokinetic and pharmacodynamic model. In addition, we analyzed the validity of the dosage regimen, and potential efficacy gained by increasing the dose and reducing the interval of administration. The sequential changes in CDAI values obtained with our model were in good agreement with observed CDAI values, which was considered to show the validity of our analysis. We considered that our results showed the importance of the loading dose of ADA to obtain remission in an early stage of active CD. In addition, we showed that patients who have an incomplete response to ADA can obtain similar efficacy from increasing the dose and reducing the dose interval. In conclusion, our results showed that the present model may be applied to predict the CDAI values of ADA for CD. They indicated the validity of the dosage regimen, as well as the efficacy of increasing the dose and reducing the dose interval. This article is protected by copyright. All rights reserved.

Gestation-specific reference intervals for comprehensive spot urinary steroid hormone metabolite analysis in normal singleton pregnancy and 6 weeks postpartum.

PubMed

Mistry, Hiten D; Eisele, Nicole; Escher, Geneviève; Dick, Bernhard; Surbek, Daniel; Delles, Christian; Currie, Gemma; Schlembach, Dietmar; Mohaupt, Markus G; Gennari-Moser, Carine

2015-09-04

Normal pregnancy depends on pronounced adaptations in steroid hormone concentrations. Although in recent years, the understanding of these hormones in pregnancy has improved, the interpretation is hampered by insufficient reference values. Our aim was to establish gestation-specific reference intervals for spot urinary steroid hormone levels in normal singleton pregnancies and 6 weeks postpartum. Cross-sectional multicentre observational study. Women recruited between 2008 and 2013 at 3 University Hospitals in Switzerland (Bern), Scotland (Glasgow) and Austria (Graz). Spot urine was collected from healthy women undergoing a normal pregnancy (age, 16-45 years; mean, 31 years) attending routine antenatal clinics at gestation weeks 11, 20, and 28 and approximately 6 weeks postpartum. Urine steroid hormone levels were analysed using gas-chromatography mass spectrometry. Creatinine was also measured by routine analysis and used for normalisation. From the results, a reference interval was calculated for each hormone metabolite at each trimester and 6 weeks postpartum. Changes in these concentrations between trimesters and postpartum were also observed for several steroid hormones and followed changes proposed for index steroid hormones. Normal gestation-specific reference values for spot urinary steroid hormones throughout pregnancy and early postpartum are now available to facilitate clinical management and research approaches to steroid hormone metabolism in pregnancy and the early postpartum period.

Population Pharmacokinetic-Pharmacodynamic Analysis to Compare the Effect of Moxifloxacin on QT Interval Prolongation Between Healthy Korean and Japanese Subjects.

PubMed

Choi, Hyang-Ki; Jung, Jin Ah; Fujita, Tomoe; Amano, Hideki; Ghim, Jong-Lyul; Lee, Dong-Hwan; Tabata, Kenichi; Song, Il-Dae; Maeda, Mika; Kumagai, Yuji; Mendzelevski, Boaz; Shin, Jae-Gook

2016-12-01

The goal of this study was to evaluate the moxifloxacin-induced QT interval prolongation in healthy male and female Korean and Japanese volunteers to investigate interethnic differences. This multicenter, randomized, double-blind, placebo-controlled, 2-way crossover study was conducted in healthy male and female Korean and Japanese volunteers. In each period, a single dose of moxifloxacin or placebo 400 mg was administered orally under fasting conditions. Triplicate 12-lead ECGs were recorded at defined time points before, up to 24 hours after dosing, and at corresponding time points during baseline. Serial blood sampling was conducted for pharmacokinetic analysis of moxifloxacin. The pharmacokinetic-pharmacodynamic data between the 2 ethnic groups were compared by using a typical analysis based on the intersection-union test and a nonlinear mixed effects method. A total of 39 healthy subjects (Korean, male: 10, female: 10; Japanese, male: 10, female: 9) were included in the analysis. The concentration-effect analysis revealed that there was no change in slope (and confirmed that the difference was caused by a change in the pharmacokinetic model of moxifloxacin). A 2-compartment model with first-order absorption provided the best description of moxifloxacin's pharmacokinetic parameters. Weight and sex were selected as significant covariates for central volume of distribution and intercompartmental clearance, respectively. An E max model (E[C]=[E max ⋅C]/[EC 50 +C]) described the QT interval data of this study well. However, ethnicity was not found to be a significant factor in a pharmacokinetic-pharmacodynamic link model. The drug-induced QTc prolongations evaluated using moxifloxacin as the probe did not seem to be significantly different between these Korean and Japanese subjects. ClinicalTrials.gov identifier: NCT01876316. Copyright © 2016 Elsevier HS Journals, Inc. All rights reserved.

Statistical analysis of strait time index and a simple model for trend and trend reversal

NASA Astrophysics Data System (ADS)

Chen, Kan; Jayaprakash, C.

2003-06-01

We analyze the daily closing prices of the Strait Time Index (STI) as well as the individual stocks traded in Singapore's stock market from 1988 to 2001. We find that the Hurst exponent is approximately 0.6 for both the STI and individual stocks, while the normal correlation functions show the random walk exponent of 0.5. We also investigate the conditional average of the price change in an interval of length T given the price change in the previous interval. We find strong correlations for price changes larger than a threshold value proportional to T; this indicates that there is no uniform crossover to Gaussian behavior. A simple model based on short-time trend and trend reversal is constructed. We show that the model exhibits statistical properties and market swings similar to those of the real market.

A cross-country Exchange Market Pressure (EMP) dataset.

PubMed

Desai, Mohit; Patnaik, Ila; Felman, Joshua; Shah, Ajay

2017-06-01

The data presented in this article are related to the research article titled - "An exchange market pressure measure for cross country analysis" (Patnaik et al. [1]). In this article, we present the dataset for Exchange Market Pressure values (EMP) for 139 countries along with their conversion factors, ρ (rho). Exchange Market Pressure, expressed in percentage change in exchange rate, measures the change in exchange rate that would have taken place had the central bank not intervened. The conversion factor ρ can interpreted as the change in exchange rate associated with $1 billion of intervention. Estimates of conversion factor ρ allow us to calculate a monthly time series of EMP for 139 countries. Additionally, the dataset contains the 68% confidence interval (high and low values) for the point estimates of ρ 's. Using the standard errors of estimates of ρ 's, we obtain one sigma intervals around mean estimates of EMP values. These values are also reported in the dataset.

Longitudinal study of fingerprint recognition.

PubMed

Yoon, Soweon; Jain, Anil K

2015-07-14

Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject's age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis.

Longitudinal study of fingerprint recognition

PubMed Central

Yoon, Soweon; Jain, Anil K.

2015-01-01

Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject’s age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis. PMID:26124106

Changes in infant disposable diaper weights at selected intervals post-wetting.

PubMed

Carlisle, Joan; Moore, Amanda; Cooper, Alyssa; Henderson, Terri; Mayfield, Debbie; Taylor, Randa; Thomas, Jennifer; Van Fleet, Laduska; Askanazi, David; Fineberg, Naomi; Sun, Yanhui

2012-01-01

Pediatric acute care nurses questioned the practice of weighing disposable infant diapers immediately after voiding. This study asked the research question, "Does volume of saline, diaper configuration, and/or size of diaper statistically effect changes in diaper weights over time?" The method was an experimental, laboratory model. Pre-set volumes of saline were added to disposable diapers that were then left folded or unfolded. Each diaper was weighed immediately post-wetting and re-weighed at hourly intervals for seven hours. Data were analyzed using a repeated measures analysis of variance (RMANOVA) with balanced data (F-test). Diaper weight changes over time were statistically significant for all time points and for all volumes regardless of diaper size; however, the changes in weight were small and without clinical significance. It is appropriate to weigh diapers at the end of eight hours without risk of altering subsequent fluid management of patients in open-air, non-humidified environments. This practice has led to more efficient use of nurses' time with fewer interruptions for patients and families.

Changes in hematological indices and lymphocyte subsets in response to whole blood donation in healthy male donors.

PubMed

Borai, Anwar; Livingstone, Callum; Alsobhi, Enaam; Al Sofyani, Abeer; Balgoon, Dalal; Farzal, Anwar; Almohammadi, Mohammed; Al-Amri, Abdulafattah; Bahijri, Suhad; Alrowaili, Daad; Bassiuni, Wafaa; Saleh, Ayman; Alrowaili, Norah; Abdelaal, Mohamed

2017-04-01

Whole blood donation has immunomodulatory effects, and most of these have been observed at short intervals following blood donation. This study aimed to investigate the impact of whole blood donation on lymphocyte subsets over a typical inter-donation interval. Healthy male subjects were recruited to study changes in complete blood count (CBC) (n = 42) and lymphocyte subsets (n = 16) before and at four intervals up to 106 days following blood donation. Repeated measures ANOVA were used to compare quantitative variables between different visits. Following blood donation, changes in CBC and erythropoietin were as expected. The neutrophil count increased by 11.3% at 8 days (p < .001). Novel changes were observed in lymphocyte subsets as the CD4/CD8 ratio increased by 9.2% (p < .05) at 8 days and 13.7% (p < .05) at 22 days. CD16-56 cells decreased by 16.2% (p < .05) at 8 days. All the subsets had returned to baseline by 106 days. Regression analysis showed that the changes in CD16-56 cells and CD4/CD8 ratio were not significant (Wilk's lambda = 0.15 and 0.94, respectively) when adjusted for BMI. In conclusion, following whole blood donation, there are transient changes in lymphocyte subsets. The effect of BMI on lymphocyte subsets and the effect of this immunomodulation on the immune response merit further investigation.

Visibility graph analysis on heartbeat dynamics of meditation training

NASA Astrophysics Data System (ADS)

Jiang, Sen; Bian, Chunhua; Ning, Xinbao; Ma, Qianli D. Y.

2013-06-01

We apply the visibility graph analysis to human heartbeat dynamics by constructing the complex networks of heartbeat interval time series and investigating the statistical properties of the network before and during chi and yoga meditation. The experiment results show that visibility graph analysis can reveal the dynamical changes caused by meditation training manifested as regular heartbeat, which is closely related to the adjustment of autonomous neural system, and visibility graph analysis is effective to evaluate the effect of meditation.

Association of cardiac implantable electronic devices with survival in bifascicular block and prolonged PR interval on electrocardiogram.

PubMed

Moulki, Naeem; Kealhofer, Jessica V; Benditt, David G; Gravely, Amy; Vakil, Kairav; Garcia, Santiago; Adabag, Selcuk

2018-06-16

Bifascicular block and prolonged PR interval on the electrocardiogram (ECG) have been associated with complete heart block and sudden cardiac death. We sought to determine if cardiac implantable electronic devices (CIED) improve survival in these patients. We assessed survival in relation to CIED status among 636 consecutive patients with bifascicular block and prolonged PR interval on the ECG. In survival analyses, CIED was considered as a time-varying covariate. Average age was 76 ± 9 years, and 99% of the patients were men. A total of 167 (26%) underwent CIED (127 pacemaker only) implantation at baseline (n = 23) or during follow-up (n = 144). During 5.4 ± 3.8 years of follow-up, 83 (13%) patients developed complete or high-degree atrioventricular block and 375 (59%) died. Patients with a CIED had a longer survival compared to those without a CIED in the traditional, static analysis (log-rank p < 0.0001) but not when CIED was considered as a time-varying covariate (log-rank p = 0.76). In the multivariable model, patients with a CIED had a 34% lower risk of death (hazard ratio 0.66, 95% confidence interval 0.52-0.83; p = 0.001) than those without CIED in the traditional analysis but not in the time-varying covariate analysis (hazard ratio 1.05, 95% confidence interval 0.79-1.38; p = 0.76). Results did not change in the subgroup with a pacemaker only. Bifascicular block and prolonged PR interval on ECG are associated with a high incidence of complete atrioventricular block and mortality. However, CIED implantation does not have a significant influence on survival when time-varying nature of CIED implantation is considered.

High-intensity interval training versus moderate-intensity continuous training within cardiac rehabilitation: a systematic review and meta-analysis.

PubMed

Hannan, Amanda L; Hing, Wayne; Simas, Vini; Climstein, Mike; Coombes, Jeff S; Jayasinghe, Rohan; Byrnes, Joshua; Furness, James

2018-01-01

Aerobic capacity has been shown to be inversely proportionate to cardiovascular mortality and morbidity and there is growing evidence that high-intensity interval training (HIIT) appears to be more effective than moderate-intensity continuous training (MICT) in improving cardiorespiratory fitness within the cardiac population. Previously published systematic reviews in cardiovascular disease have neither investigated the effect that the number of weeks of intervention has on cardiorespiratory fitness changes, nor have adverse events been collated. We aimed to undertake a systematic review and meta-analysis of randomized controlled trials (RCTs) within the cardiac population that investigated cardiorespiratory fitness changes resulting from HIIT versus MICT and to collate adverse events. A critical narrative synthesis and meta-analysis was conducted after systematically searching relevant databases up to July 2017. We searched for RCTs that compared cardiorespiratory fitness changes resulting from HIIT versus MICT interventions within the cardiac population. Seventeen studies, involving 953 participants (465 for HIIT and 488 for MICT) were included in the analysis. HIIT was significantly superior to MICT in improving cardiorespiratory fitness overall (SMD 0.34 mL/kg/min; 95% confidence interval [CI; 0.2-0.48]; p <0.00001; I 2 =28%). There were no deaths or cardiac events requiring hospitalization reported in any study during training. Overall, there were more adverse events reported as a result of the MICT (n=14) intervention than the HIIT intervention (n=9). However, some adverse events (n=5) were not classified by intervention group. HIIT is superior to MICT in improving cardiorespiratory fitness in participants of cardiac rehabilitation (CR). Improvements in cardiorespiratory fitness are significant for CR programs of >6-week duration. Programs of 7-12 weeks' duration resulted in the largest improvements in cardiorespiratory fitness for patients with coronary artery disease. HIIT appears to be as safe as MICT for CR participants.

High-intensity interval training versus moderate-intensity continuous training within cardiac rehabilitation: a systematic review and meta-analysis

PubMed Central

Hannan, Amanda L; Hing, Wayne; Simas, Vini; Climstein, Mike; Coombes, Jeff S; Jayasinghe, Rohan; Byrnes, Joshua; Furness, James

2018-01-01

Background Aerobic capacity has been shown to be inversely proportionate to cardiovascular mortality and morbidity and there is growing evidence that high-intensity interval training (HIIT) appears to be more effective than moderate-intensity continuous training (MICT) in improving cardiorespiratory fitness within the cardiac population. Previously published systematic reviews in cardiovascular disease have neither investigated the effect that the number of weeks of intervention has on cardiorespiratory fitness changes, nor have adverse events been collated. Objective We aimed to undertake a systematic review and meta-analysis of randomized controlled trials (RCTs) within the cardiac population that investigated cardiorespiratory fitness changes resulting from HIIT versus MICT and to collate adverse events. Methods A critical narrative synthesis and meta-analysis was conducted after systematically searching relevant databases up to July 2017. We searched for RCTs that compared cardiorespiratory fitness changes resulting from HIIT versus MICT interventions within the cardiac population. Results Seventeen studies, involving 953 participants (465 for HIIT and 488 for MICT) were included in the analysis. HIIT was significantly superior to MICT in improving cardiorespiratory fitness overall (SMD 0.34 mL/kg/min; 95% confidence interval [CI; 0.2–0.48]; p<0.00001; I2=28%). There were no deaths or cardiac events requiring hospitalization reported in any study during training. Overall, there were more adverse events reported as a result of the MICT (n=14) intervention than the HIIT intervention (n=9). However, some adverse events (n=5) were not classified by intervention group. Conclusion HIIT is superior to MICT in improving cardiorespiratory fitness in participants of cardiac rehabilitation (CR). Improvements in cardiorespiratory fitness are significant for CR programs of >6-week duration. Programs of 7–12 weeks’ duration resulted in the largest improvements in cardiorespiratory fitness for patients with coronary artery disease. HIIT appears to be as safe as MICT for CR participants. PMID:29416382

‘It has saved thousands of lives, so why change it?’ Content analysis of objections to cervical screening programme changes in Australia

PubMed Central

Bonner, Carissa; Jansen, Jesse; McCaffery, Kirsten

2018-01-01

Objectives The incidence and mortality of cervical cancer have halved since introduction of the Australian cervical screening programme in 1991, involving 2-yearly Pap smears from ages 18–69 years. In 2017, the programme changed to 5- yearly primary human papillomavirus (HPV) testing for women aged 25–74 years. This study investigated reasons for opposition to the renewed screening programme within the open-ended comments of an online petition, ‘Stop May 1st Changes to Pap Smears—Save Women’s Lives’, opposing the changes, which received over 70 000 signatures and almost 20 000 comments. Methods Content analysis of a random sample of 2000 comments, reflecting 10% of the 19 633 comments posted in February–March 2017. Results Nineteen codes were identified, reflecting four themes: (1) valuing women’s health and rights, (2) political statements, (3) concerns about healthcare funding cuts and (4) opposition to specific components of the new screening programme. The most prevalent codes were: placing value on women’s health (33%), concerns about increasing screening intervals (17%) and opposition to the changes related to personal experiences with cervical cancer or cervical abnormalities (15%). Concern about the key change in technology (HPV testing instead of Pap smears) was expressed in less than 3% of comments, and some opposition to the changes from health professionals was noted. Conclusions Screening changes within this selected group were perceived as threatening women’s health, as a political policy created by male decision-makers and as a cost-cutting exercise. Many commenters were concerned about increased screening intervals and later screening onset, but little opposition was expressed regarding the testing technology itself. This analysis may inform public education and communication strategies for future changes to cervical screening programmes internationally, to pre-emptively address specific concerns about the changes. PMID:29440214

Primary-Care Weight-Management Strategies: Parental Priorities and Preferences.

PubMed

Turer, Christy Boling; Upperman, Carla; Merchant, Zahra; Montaño, Sergio; Flores, Glenn

2016-04-01

To examine parental perspectives/rankings of the most important weight-management clinical practices and to determine whether preferences/rankings differ when parents disagree that their child is overweight. We performed mixed-methods analysis of a 32-question survey of parents of 2- to 18-year-old overweight children assessing parental agreement that their child is overweight, the single most important thing providers can do to improve weight status, ranking American Academy of Pediatrics-recommended clinical practices, and preferred follow-up interval. Four independent reviewers analyzed open-response data to identify qualitative themes/subthemes. Multivariable analyses examined parental rankings, preferred follow-up interval, and differences by agreement with their child's overweight assessment. Thirty-six percent of 219 children were overweight, 42% obese, and 22% severely obese; 16% of parents disagreed with their child's overweight assessment. Qualitative analysis of the most important practice to help overweight children yielded 10 themes; unique to parents disagreeing with their children's overweight assessments was "change weight-status assessments." After adjustment, the 3 highest-ranked clinical practices included, "check for weight-related problems," "review growth chart," and "recommend general dietary changes" (all P < .01); parents disagreeing with their children's overweight assessments ranked "review growth chart" as less important and ranked "reducing screen time" and "general activity changes" as more important. The mean preferred weight-management follow-up interval (10-12 weeks) did not differ by agreement with children's overweight assessments. Parents prefer weight-management strategies that prioritize evaluating weight-related problems, growth-chart review, and regular follow-up. Parents who disagree that their child is overweight want changes in how overweight is assessed. Using parent-preferred weight-management strategies may prove useful in improving child weight status. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Rapid Holocene coastal change revealed by high-resolution micropaleontological analysis, Pamlico Sound, North Carolina, USA

USGS Publications Warehouse

Grand, Pre C.; Culver, S.J.; Mallinson, D.J.; Farrell, K.M.; Corbett, D.R.; Horton, B.P.; Hillier, C.; Riggs, S.R.; Snyder, S.W.; Buzas, M.A.

2011-01-01

Foraminiferal analyses of 404 contiguous samples, supported by diatom, lithologic, geochronologic and seismic data, reveal both rapid and gradual Holocene paleoenvironmental changes in an 8.21-m vibracore taken from southern Pamlico Sound, North Carolina. Data record initial flooding of a latest Pleistocene river drainage and the formation of an estuary 9000. yr ago. Estuarine conditions were punctuated by two intervals of marine influence from approximately 4100 to 3700 and 1150 to 500. cal. yr BP. Foraminiferal assemblages in the muddy sand facies that accumulated during these intervals contain many well-preserved benthic foraminiferal species, which occur today in open marine settings as deep as the mid shelf, and significant numbers of well-preserved planktonic foraminifera, some typical of Gulf Stream waters. We postulate that these marine-influenced units resulted from temporary destruction of the southern Outer Banks barrier islands by hurricanes. The second increase in marine influence is coeval with increased rate of sea-level rise and a peak in Atlantic tropical cyclone activity during the Medieval Climate Anomaly. This high-resolution analysis demonstrates the range of environmental variability and the rapidity of coastal change that can result from the interplay of changing climate, sea level and geomorphology in an estuarine setting. ?? 2011 University of Washington.

Potential confounding in the association between short birth intervals and increased neonatal, infant, and child mortality

PubMed Central

Perin, Jamie; Walker, Neff

2015-01-01

Background Recent steep declines in child mortality have been attributed in part to increased use of contraceptives and the resulting change in fertility behaviour, including an increase in the time between births. Previous observational studies have documented strong associations between short birth spacing and an increase in the risk of neonatal, infant, and under-five mortality, compared to births with longer preceding birth intervals. In this analysis, we compare two methods to estimate the association between short birth intervals and mortality risk to better inform modelling efforts linking family planning and mortality in children. Objectives Our goal was to estimate the mortality risk for neonates, infants, and young children by preceding birth space using household survey data, controlling for mother-level factors and to compare the results to those from previous analyses with survey data. Design We assessed the potential for confounding when estimating the relative mortality risk by preceding birth interval and estimated mortality risk by birth interval in four categories: less than 18 months, 18–23 months, 24–35 months, and 36 months or longer. We estimated the relative risks among women who were 35 and older at the time of the survey with two methods: in a Cox proportional hazards regression adjusting for potential confounders and also by stratifying Cox regression by mother, to control for all factors that remain constant over a woman's childbearing years. We estimated the overall effects for birth spacing in a meta-analysis with random survey effects. Results We identified several factors known for their associations with neonatal, infant, and child mortality that are also associated with preceding birth interval. When estimating the effect of birth spacing on mortality, we found that regression adjustment for these factors does not substantially change the risk ratio for short birth intervals compared to an unadjusted mortality ratio. For birth intervals less than 18 months, standard regression adjustment for confounding factors estimated a risk ratio for neonatal mortality of 2.28 (95% confidence interval: 2.18–2.37). This same effect estimated within mother is 1.57 (95% confidence interval: 1.52–1.63), a decline of almost one-third in the effect on neonatal mortality. Conclusions Neonatal, infant, and child mortality are strongly and significantly related to preceding birth interval, where births within a short interval of time after the previous birth have increased mortality. Previous analyses have demonstrated this relationship on average across all births; however, women who have short spaces between births are different from women with long spaces. Among women 35 years and older where a comparison of birth spaces within mother is possible, we find a much reduced although still significant effect of short birth spaces on child mortality. PMID:26562139

Potential confounding in the association between short birth intervals and increased neonatal, infant, and child mortality.

PubMed

Perin, Jamie; Walker, Neff

2015-01-01

Recent steep declines in child mortality have been attributed in part to increased use of contraceptives and the resulting change in fertility behaviour, including an increase in the time between births. Previous observational studies have documented strong associations between short birth spacing and an increase in the risk of neonatal, infant, and under-five mortality, compared to births with longer preceding birth intervals. In this analysis, we compare two methods to estimate the association between short birth intervals and mortality risk to better inform modelling efforts linking family planning and mortality in children. Our goal was to estimate the mortality risk for neonates, infants, and young children by preceding birth space using household survey data, controlling for mother-level factors and to compare the results to those from previous analyses with survey data. We assessed the potential for confounding when estimating the relative mortality risk by preceding birth interval and estimated mortality risk by birth interval in four categories: less than 18 months, 18-23 months, 24-35 months, and 36 months or longer. We estimated the relative risks among women who were 35 and older at the time of the survey with two methods: in a Cox proportional hazards regression adjusting for potential confounders and also by stratifying Cox regression by mother, to control for all factors that remain constant over a woman's childbearing years. We estimated the overall effects for birth spacing in a meta-analysis with random survey effects. We identified several factors known for their associations with neonatal, infant, and child mortality that are also associated with preceding birth interval. When estimating the effect of birth spacing on mortality, we found that regression adjustment for these factors does not substantially change the risk ratio for short birth intervals compared to an unadjusted mortality ratio. For birth intervals less than 18 months, standard regression adjustment for confounding factors estimated a risk ratio for neonatal mortality of 2.28 (95% confidence interval: 2.18-2.37). This same effect estimated within mother is 1.57 (95% confidence interval: 1.52-1.63), a decline of almost one-third in the effect on neonatal mortality. Neonatal, infant, and child mortality are strongly and significantly related to preceding birth interval, where births within a short interval of time after the previous birth have increased mortality. Previous analyses have demonstrated this relationship on average across all births; however, women who have short spaces between births are different from women with long spaces. Among women 35 years and older where a comparison of birth spaces within mother is possible, we find a much reduced although still significant effect of short birth spaces on child mortality.

Some changes of the heart bioelectric activity at the cosmonauts under the influence of LBNP in the long duration flights.

PubMed

Shelepnevich, S O; Alferova, I V; Golybchicova, Z A

2004-07-01

There was selected the group of the cosmonauts, who carry out long duration flights on the orbital complex "Mir", in which the tolerance of LBNP test was evaluated as poor (by hemodynamic indices--heart rate, arterial pressure, rheoencephalographic indices). The in-depth analysis of the electrocardiogram (in DS leads) indices was carry oiled on possible disturbances of conductivity and dynamics of temporary or amplitude characteristics. Furthermore is carry oiled the comparative estimation of these indices with the results of ECG analysis at the cosmonauts, who tolerance test good. Studies showed that the most informative ECG indices are the R, T-amplitudes and QT-interval. Under the influence of LBNP, especially during rarefactions on 45 and 50 mm Hg was noted reduction in the R, T-amplitude and the relative extension of QT-interval. The directivity of changes in these indices are identical for the cosmonauts with good and poor tolerance of the test; however in flight manifestation of the changes is more significant for the cosmonauts with poor tolerance of LBNP test. Thus, in the formation of orthostatic stability together with the hemodynamic influences take part the bioelectric processes, which are formed in the myocardium.

Fixed-interval performance and self-control in children.

PubMed Central

Darcheville, J C; Rivière, V; Wearden, J H

1992-01-01

Operant responses of 16 children (mean age 6 years and 1 month) were reinforced according to different fixed-interval schedules (with interreinforcer intervals of 20, 30, or 40 s) in which the reinforcers were either 20-s or 40-s presentations of a cartoon. In another procedure, they received training on a self-control paradigm in which both reinforcer delay (0.5 s or 40 s) and reinforcer duration (20 s or 40 s of cartoons) varied, and subjects were offered a choice between various combinations of delay and duration. Individual differences in behavior under the self-control procedure were precisely mirrored by individual differences under the fixed-interval schedule. Children who chose the smaller immediate reinforcer on the self-control procedure (impulsive) produced short postreinforcement pauses and high response rates in the fixed-interval conditions, and both measures changed little with changes in fixed-interval value. Conversely, children who chose the larger delayed reinforcer in the self-control condition (the self-controlled subjects) exhibited lower response rates and long postreinforcement pauses, which changed systematically with changes in the interval, in their fixed-interval performances. PMID:1573372

Statistical physics approaches to financial fluctuations

NASA Astrophysics Data System (ADS)

Wang, Fengzhong

2009-12-01

Complex systems attract many researchers from various scientific fields. Financial markets are one of these widely studied complex systems. Statistical physics, which was originally developed to study large systems, provides novel ideas and powerful methods to analyze financial markets. The study of financial fluctuations characterizes market behavior, and helps to better understand the underlying market mechanism. Our study focuses on volatility, a fundamental quantity to characterize financial fluctuations. We examine equity data of the entire U.S. stock market during 2001 and 2002. To analyze the volatility time series, we develop a new approach, called return interval analysis, which examines the time intervals between two successive volatilities exceeding a given value threshold. We find that the return interval distribution displays scaling over a wide range of thresholds. This scaling is valid for a range of time windows, from one minute up to one day. Moreover, our results are similar for commodities, interest rates, currencies, and for stocks of different countries. Further analysis shows some systematic deviations from a scaling law, which we can attribute to nonlinear correlations in the volatility time series. We also find a memory effect in return intervals for different time scales, which is related to the long-term correlations in the volatility. To further characterize the mechanism of price movement, we simulate the volatility time series using two different models, fractionally integrated generalized autoregressive conditional heteroscedasticity (FIGARCH) and fractional Brownian motion (fBm), and test these models with the return interval analysis. We find that both models can mimic time memory but only fBm shows scaling in the return interval distribution. In addition, we examine the volatility of daily opening to closing and of closing to opening. We find that each volatility distribution has a power law tail. Using the detrended fluctuation analysis (DFA) method, we show long-term auto-correlations in these volatility time series. We also analyze return, the actual price changes of stocks, and find that the returns over the two sessions are often anti-correlated.

Longitudinal change in dysarthria associated with Friedreich ataxia: a potential clinical endpoint.

PubMed

Rosen, Kristin M; Folker, Joanne E; Vogel, Adam P; Corben, Louise A; Murdoch, Bruce E; Delatycki, Martin B

2012-11-01

CNS functions that show change across short periods of time are particularly useful clinical endpoints for Friedreich ataxia. This study determined whether there is measurable acoustical change in the dysarthria associated with Friedreich ataxia across yearly intervals. A total of 29 participants diagnosed with Friedreich ataxia were recorded across 4 years at yearly intervals. A repeated measures ANOVA was used to determine which acoustic measures differed across time, and pairwise t tests were used to assess the consistency of the change across the time intervals. The relationship between the identified measures with perceptual severity was assessed with stepwise regression. Significant longitudinal change was observed with four measures that relate to the utterance duration and spectral changes in utterances. The spectral measures consistently detected change across time intervals of two or more years. The four measures combined moderately predicted perceptual severity. Together, the results implicate longitudinal change in speaking rate and utterance duration. Changes in speech associated with Friedreich ataxia can be measured across intervals of 2 years and therefore show rich potential for monitoring disease progression and therapy outcomes.

Repeated stimulation, inter-stimulus interval and inter-electrode distance alters muscle contractile properties as measured by Tensiomyography

PubMed Central

Johnson, Mark I.; Francis, Peter

2018-01-01

Context The influence of methodological parameters on the measurement of muscle contractile properties using Tensiomyography (TMG) has not been published. Objective To investigate the; (1) reliability of stimulus amplitude needed to elicit maximum muscle displacement (Dm), (2) effect of changing inter-stimulus interval on Dm (using a fixed stimulus amplitude) and contraction time (Tc), (3) the effect of changing inter-electrode distance on Dm and Tc. Design Within subject, repeated measures. Participants 10 participants for each objective. Main outcome measures Dm and Tc of the rectus femoris, measured using TMG. Results The coefficient of variance (CV) and the intra-class correlation (ICC) of stimulus amplitude needed to elicit maximum Dm was 5.7% and 0.92 respectively. Dm was higher when using an inter-electrode distance of 7cm compared to 5cm [P = 0.03] and when using an inter-stimulus interval of 10s compared to 30s [P = 0.017]. Further analysis of inter-stimulus interval data, found that during 10 repeated stimuli Tc became faster after the 5th measure when compared to the second measure [P<0.05]. The 30s inter-stimulus interval produced the most stable Tc over 10 measures compared to 10s and 5s respectively. Conclusion Our data suggest that the stimulus amplitude producing maximum Dm of the rectus femoris is reliable. Inter-electrode distance and inter-stimulus interval can significantly influence Dm and/ or Tc. Our results support the use of a 30s inter-stimulus interval over 10s or 5s. Future studies should determine the influence of methodological parameters on muscle contractile properties in a range of muscles. PMID:29451885

Uricaemia as a cardiovascular events risk factor in hypertension: the role of interval training programme in its downregulation.

PubMed

Lamina, Sikiru; Okoye, Chuba G

2011-01-01

Elevated serum uric acid is considered to be positively associated with cardiovascular event risk factor in hypertension. Also, the positive role of exercise in the management of Hypertension has been well and long established. However the relationship between serum uric acid (SUA) level and hypertensive management particularly in non pharmacological technique is ambiguous and unclear. Therefore the purpose of the present study was to determine the effect of interval training programme on serum uric acid level and cardiovascular parameters in male subjects with hypertension. Two hundred and forty five male patients with mild to moderate (systolic blood pressure [SBP] between 140-180 and diastolic blood pressure [DBP] between 90-109 mmHg) essential hypertension were age matched and grouped into interval and control groups. The interval (n = 140; 58.90 +/- 7.35 years) group involved in an 8 weeks interval training (60-79% HR max reserve) programme of between 45 minutes to 60 minutes at a work/rest ratio of 1:1 of 6 minutes each, while age-matched controls hypertensive (n = 105; 58.27 +/- 6.24 years) group remain sedentary during this period. Cardiovascular parameters (SBP, DBP and VO2max) and serum uric acid were assessed. Students' t and Pearson correlation tests were used in data analysis. Findings of the study revealed significant effect of interval training programme on VO2max, SBP, DBP and serum uric acid level at p < 0.05. Also there was significant correlation between changes VO2max and changes in SUA, SBP and DBP. It was concluded that interval training programme is an effective non-pharmacological means of downregulation of SUA.

Large capacity storage of integrated objects before change blindness.

PubMed

Landman, Rogier; Spekreijse, Henk; Lamme, Victor A F

2003-01-01

Normal people have a strikingly low ability to detect changes in a visual scene. This has been taken as evidence that the brain represents only a few objects at a time, namely those currently in the focus of attention. In the present study, subjects were asked to detect changes in the orientation of rectangular figures in a textured display across a 1600 ms gray interval. In the first experiment, change detection improved when the location of a possible change was cued during the interval. The cue remained effective during the entire interval, but after the interval, it was ineffective, suggesting that an initially large representation was overwritten by the post-change display. To control for an effect of light intensity during the interval on the decay of the representation, we compared performance with a gray or a white interval screen in a second experiment. We found no difference between these conditions. In the third experiment, attention was occasionally misdirected during the interval by first cueing the wrong figure, before cueing the correct figure. This did not compromise performance compared to a single cue, indicating that when an item is attentionally selected, the representation of yet unchosen items remains available. In the fourth experiment, the cue was shown to be effective when changes in figure size and orientation were randomly mixed. At the time the cue appeared, subjects could not know whether size or orientation would change, therefore these results suggest that the representation contains features in their 'bound' state. Together, these findings indicate that change blindness involves overwriting of a large capacity representation by the post-change display.

The use of simple indicators for detecting potential coronary heart disease susceptibility in the air traffic controller population.

DOT National Transportation Integrated Search

1972-05-01

An analysis was made of an eight-year interval change in several indicators of coronary heart disease (CHD) susceptibility as measured on 475 male air traffic control (ATC) personnel. The initial measurements were obtained from these personnel as ATC...

The use of simple indicators for detecting potential coronary heart disease susceptibility in the third-class airman population.

DOT National Transportation Integrated Search

1972-07-01

An analysis was made of an eight-year interval change in several Framingham Heart Study (FHS) indicators of coronary heart disease (CHD) susceptibility as measured on 475 male air traffic control (ATC) personnel. The initial measurements were obtaine...

Synchronized changes to relative neuron populations in postnatal human neocortical development

PubMed Central

Cooper, David L.; Gentle, James E.; Barreto, Ernest

2010-01-01

Mammalian prenatal neocortical development is dominated by the synchronized formation of the laminae and migration of neurons. Postnatal development likewise contains “sensitive periods” during which functions such as ocular dominance emerge. Here we introduce a novel neuroinformatics approach to identify and study these periods of active development. Although many aspects of the approach can be used in other studies, some specific techniques were chosen because of a legacy dataset of human histological data (Conel in The postnatal development of the human cerebral cortex, vol 1–8. Harvard University Press, Cambridge, 1939–1967). Our method calculates normalized change vectors from the raw histological data, and then employs k-means cluster analysis of the change vectors to explore the population dynamics of neurons from 37 neocortical areas across eight postnatal developmental stages from birth to 72 months in 54 subjects. We show that the cortical “address” (Brodmann area/sub-area and layer) provides the necessary resolution to segregate neuron population changes into seven correlated “k-clusters” in k-means cluster analysis. The members in each k-cluster share a single change interval where the relative share of the cortex by the members undergoes its maximum change. The maximum change occurs in a different change interval for each k-cluster. Each k-cluster has at least one totally connected maximal “clique” which appears to correspond to cortical function. Electronic supplementary material The online version of this article (doi:10.1007/s11571-010-9103-3) contains supplementary material, which is available to authorized users. PMID:21629587

Daily average temperature and mortality among the elderly: a meta-analysis and systematic review of epidemiological evidence

NASA Astrophysics Data System (ADS)

Yu, Weiwei; Mengersen, Kerrie; Wang, Xiaoyu; Ye, Xiaofang; Guo, Yuming; Pan, Xiaochuan; Tong, Shilu

2012-07-01

The impact of climate change on the health of vulnerable groups such as the elderly has been of increasing concern. However, to date there has been no meta-analysis of current literature relating to the effects of temperature fluctuations upon mortality amongst the elderly. We synthesised risk estimates of the overall impact of daily mean temperature on elderly mortality across different continents. A comprehensive literature search was conducted using MEDLINE and PubMed to identify papers published up to December 2010. Selection criteria including suitable temperature indicators, endpoints, study-designs and identification of threshold were used. A two-stage Bayesian hierarchical model was performed to summarise the percent increase in mortality with a 1°C temperature increase (or decrease) with 95% confidence intervals in hot (or cold) days, with lagged effects also measured. Fifteen studies met the eligibility criteria and almost 13 million elderly deaths were included in this meta-analysis. In total, there was a 2-5% increase for a 1°C increment during hot temperature intervals, and a 1-2 % increase in all-cause mortality for a 1°C decrease during cold temperature intervals. Lags of up to 9 days in exposure to cold temperature intervals were substantially associated with all-cause mortality, but no substantial lagged effects were observed for hot intervals. Thus, both hot and cold temperatures substantially increased mortality among the elderly, but the magnitude of heat-related effects seemed to be larger than that of cold effects within a global context.

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.

Age-related changes in hematology and plasma chemistry values of hybrid striped bass (Morone chrysops X Morone saxatilis).

PubMed

Hrubec, Terry C.; Smith, Stephen A.; Robertson, John L.

2001-01-01

Hybrid striped bass (Morone chrysops X Morone saxatilis ) are an important aquaculture species yet there are few diagnostic tools available to assess their health. Hematology and clinical chemistry analyses are not used extensively in fish medicine due to the lack of reference intervals for various fish species, and because factors such as age can affect blood values. There is little published information regarding age-related changes in blood values of juvenile fish. It is important to evaluate juvenile fish, as this is the time they are raised in aquaculture settings. Determining age-related changes in the blood values of fishes would further develop clinical pathology as a diagnostic tool, enhancing both fish medicine and the aquaculture industry. The results of standard hematology and clinical chemistry analysis were evaluated in juvenile hybrid striped bass at 4, 6, 9, 15, and 19 months of age. Values for PCV and RBC indices were significantly lower, and plasma protein concentration was significantly higher in younger fish. Total WBC and lymphocyte counts were significantly higher in fish at 6 and 9 months of age, while neutrophil and monocyte counts were higher at 6, 9, and 15 months. Eosinophil counts were significantly higher in 9-month-old fish. The majority of hematologic values fell within previously established reference intervals, indicating that only slight modification to the intervals is necessary for evaluating hematologic results of hybrid striped bass at different ages. The following analytes deviated sufficiently from adult reference intervals to warrant separate reference values: plasma protein concentration at 4 months, WBC and lymphocyte counts at 15 and 19 months, and thrombocyte-like-cells at 9 months of age. Values for most biochemical analytes were significantly different among age groups except for creatinine and potassium concentrations. Comparisons with reference intervals were not made for biochemical analytes, because established reference intervals were not available. Age-related changes in hematologic and biochemical values of striped bass were similar to those reported for rainbow trout and mammals.

Identification of speech transients using variable frame rate analysis and wavelet packets.

PubMed

Rasetshwane, Daniel M; Boston, J Robert; Li, Ching-Chung

2006-01-01

Speech transients are important cues for identifying and discriminating speech sounds. Yoo et al. and Tantibundhit et al. were successful in identifying speech transients and, emphasizing them, improving the intelligibility of speech in noise. However, their methods are computationally intensive and unsuitable for real-time applications. This paper presents a method to identify and emphasize speech transients that combines subband decomposition by the wavelet packet transform with variable frame rate (VFR) analysis and unvoiced consonant detection. The VFR analysis is applied to each wavelet packet to define a transitivity function that describes the extent to which the wavelet coefficients of that packet are changing. Unvoiced consonant detection is used to identify unvoiced consonant intervals and the transitivity function is amplified during these intervals. The wavelet coefficients are multiplied by the transitivity function for that packet, amplifying the coefficients localized at times when they are changing and attenuating coefficients at times when they are steady. Inverse transform of the modified wavelet packet coefficients produces a signal corresponding to speech transients similar to the transients identified by Yoo et al. and Tantibundhit et al. A preliminary implementation of the algorithm runs more efficiently.

Geodynamic Evolution of Northeastern Tunisia During the Maastrichtian-Paleocene Time: Insights from Integrated Seismic Stratigraphic Analysis

NASA Astrophysics Data System (ADS)

Abidi, Oussama; Inoubli, Mohamed Hédi; Sebei, Kawthar; Amiri, Adnen; Boussiga, Haifa; Nasr, Imen Hamdi; Salem, Abdelhamid Ben; Elabed, Mahmoud

2017-05-01

The Maastrichtian-Paleocene El Haria formation was studied and defined in Tunisia on the basis of outcrops and borehole data; few studies were interested in its three-dimensional extent. In this paper, the El Haria formation is reviewed in the context of a tectono-stratigraphic interval using an integrated seismic stratigraphic analysis based on borehole lithology logs, electrical well logging, well shots, vertical seismic profiles and post-stack surface data. Seismic analysis benefits from appropriate calibration with borehole data, conventional interpretation, velocity mapping, seismic attributes and post-stack model-based inversion. The applied methodology proved to be powerful for charactering the marly Maastrichtian-Paleocene interval of the El Haria formation. Migrated seismic sections together with borehole measurements are used to detail the three-dimensional changes in thickness, facies and depositional environment in the Cap Bon and Gulf of Hammamet regions during the Maastrichtian-Paleocene time. Furthermore, dating based on their microfossil content divulges local and multiple internal hiatuses within the El Haria formation which are related to the geodynamic evolution of the depositional floor since the Campanian stage. Interpreted seismic sections display concordance, unconformities, pinchouts, sedimentary gaps, incised valleys and syn-sedimentary normal faulting. Based on the seismic reflection geometry and terminations, seven sequences are delineated. These sequences are related to base-level changes as the combination of depositional floor paleo-topography, tectonic forces, subsidence and the developed accommodation space. These factors controlled the occurrence of the various parts of the Maastrichtian-Paleocene interval. Detailed examinations of these deposits together with the analysis of the structural deformation at different time periods allowed us to obtain a better understanding of the sediment architecture in depth and the delineation of the geodynamic evolution of the region.

Change in Breast Cancer Screening Intervals Since the 2009 USPSTF Guideline.

PubMed

Wernli, Karen J; Arao, Robert F; Hubbard, Rebecca A; Sprague, Brian L; Alford-Teaster, Jennifer; Haas, Jennifer S; Henderson, Louise; Hill, Deidre; Lee, Christoph I; Tosteson, Anna N A; Onega, Tracy

2017-08-01

In 2009, the U.S. Preventive Services Task Force (USPSTF) recommended biennial mammography for women aged 50-74 years and shared decision-making for women aged 40-49 years for breast cancer screening. We evaluated changes in mammography screening interval after the 2009 recommendations. We conducted a prospective cohort study of women aged 40-74 years who received 821,052 screening mammograms between 2006 and 2012 using data from the Breast Cancer Surveillance Consortium. We compared changes in screening intervals and stratified intervals based on whether the mammogram at the end of the interval occurred before or after the 2009 recommendation. Differences in mean interval length by woman-level characteristics were compared using linear regression. The mean interval (in months) minimally decreased after the 2009 USPSTF recommendations. Among women aged 40-49 years, the mean interval decreased from 17.2 months to 17.1 months (difference -0.16%, 95% confidence interval [CI] -0.30 to -0.01). Similar small reductions were seen for most age groups. The largest change in interval length in the post-USPSTF period was declines among women with a first-degree family history of breast cancer (difference -0.68%, 95% CI -0.82 to -0.54) or a 5-year breast cancer risk ≥2.5% (difference -0.58%, 95% CI -0.73 to -0.44). The 2009 USPSTF recommendation did not lengthen the average mammography interval among women routinely participating in mammography screening. Future studies should evaluate whether breast cancer screening intervals lengthen toward biennial intervals following new national 2016 breast cancer screening recommendations, particularly among women less than 50 years of age.

What’s Driving Uncertainty? The Model or the Model Parameters (What’s Driving Uncertainty? The influences of model and model parameters in data analysis)

DOE PAGES

Anderson-Cook, Christine Michaela

2017-03-01

Here, one of the substantial improvements to the practice of data analysis in recent decades is the change from reporting just a point estimate for a parameter or characteristic, to now including a summary of uncertainty for that estimate. Understanding the precision of the estimate for the quantity of interest provides better understanding of what to expect and how well we are able to predict future behavior from the process. For example, when we report a sample average as an estimate of the population mean, it is good practice to also provide a confidence interval (or credible interval, if youmore » are doing a Bayesian analysis) to accompany that summary. This helps to calibrate what ranges of values are reasonable given the variability observed in the sample and the amount of data that were included in producing the summary.« less

Ventricular Effective Refraction Period and Ventricular Repolarization Analysis in Experimental Tachycardiomyopathy in Swine.

PubMed

Noszczyk-Nowak, Agnieszka; Pasławska, Urszula; Gajek, Jacek; Janiszewski, Adrian; Pasławski, Robert; Zyśko, Dorota; Nicpoń, Józef

2016-01-01

Swine are recognized animal models of human cardiovascular diseases. However, little is known on the CHF-associated changes in the electrophysiological ventricular parameters of humans and animals. The aim of this study was to analyze changes in the durations of ventricular effective refraction period (VERP), QT and QTc intervals of pigs with chronic tachycardia-induced tachycardiomyopathy (TIC). The study was comprised of 28 adult pigs (8 females and 20 males) of the Polish Large White breed. A one-chamber pacemaker was implanted in each of the 28 pigs. Electrocardiographic, echocardiographic and electrophysiological studies were carried out prior to the pacemaker implantation and at subsequent 4-week intervals. All electrocardiographic, echocardiographic and short electrophysiological study measurements in all swine were done under general anesthesia (propofol) after premedication with midazolam, medetomidine, and ketamine. No significant changes in the duration of QT interval and corrected QT interval (QTc) were observed during consecutive weeks of the experiment. The duration of the QTc interval of female pigs was shown to be significantly longer than that of the males throughout the whole study period. Beginning from the 12th week of rapid ventricular pacing, a significant increase in duration of VERP was observed in both male and female pigs. Males and females did not differ significantly in terms of VERP duration determined throughout the whole study period. Ventricular pacing, stimulation with 2 and 3 premature impulses at progressively shorter coupling intervals and an imposed rhythm of 130 bpm or 150 bpm induced transient ventricular tachycardia in one female pig and four male pigs. One episode of permanent ventricular tachycardia was observed. The number of induced arrhythmias increased proportionally to the severity of heart failure and duration of the experiment. However, relatively aggressive protocols of stimulation were required in order to induce arrhythmia in the studied pigs.

The benthic fauna from the lower Maastrichtian chalk of Kronsmoor (Saturn quarry, northern Germany): composition and palaeoecologic implications

NASA Astrophysics Data System (ADS)

Engelke, Julia; Linnert, Christian; Mutterlose, Jörg; Wilmsen, Markus

2017-04-01

The Saturn quarry near Kronsmoor (northern Germany) offers an undisturbed section of upper Campanian to lower Maastrichtian chalks. The target interval of the DFG project "Biodiversity and plankton-benthos coupling: an integrated ecosystem analysis from the Late Cretaceous Chalk" is focused on the lower Maastrichtian Belemnella obtusa Zone to mid-Belemnella sumensis Zone, i.e. to the uppermost Kronsmoor and lowermost Hemmoor formations. In this interval, a conspicuous increase in macrofossil abundance without apparent lithofacies changes has been observed and the project intends to integrate planktic, benthic and geochemical proxies for a comprehensive understanding of the Chalk Sea ecosystem. The aim of this study is the analysis of the benthic community. In a first step, the benthic body fossils of the c. 25-m-thick section were semi-quantitatively studied based on a collection of more than 1,000 specimens. Two successive benthic macrofossil assemblages were recognised: the lower interval (upper part of the Kronsmoor Formation, B. obtusa Zone) is characterized by low abundances, only about 100 macroinvertebrates were collected, mostly irregular and regular echinoids, brachiopods and crinoids. The upper interval (B. sumensis Zone) shows an eight times higher macroinvertebrate abundance and a conspicuous dominance of brachiopods, increasing from only 30 to over 500 specimens. In order to quantify the observed qualitative palaeoecological changes, 33 bulk samples of about 6 kg each were retrieved in a distance of c. 0.75 m. The bulk samples were frozen and thawed, washed and sieved in different sizes. The fraction 500 μm-1 mm and >1 mm were picked, sorted and counted. A diverse assemblage of bryozoans, foraminifers, shell fragments of brachiopods and bivalves, spines and test fragments of different echinoid taxa, parts of asteroids and ophiuroids, sponge debris, crinoids and small serpulids, is present. Reduced abundances in the lower part and generally higher abundances in the upper part are recognised. The palaeoecological analysis of both datasets indicates different guilds, of which epifaunal suspension feeders (fixo-sessile and libero-sessile guilds), comprising c. 50 % of the fauna in the lower interval, increase to a dominance of c. 80 % in the upper interval, including a considerable proportion of rhynchonelliform brachiopods. The palaeoecological data of benthic communities at Kronsmoor are indicative of increased nutrient availability during the early Maastrichtian. However, in the absence of any evidence of increased productivity in the overlying photic zone (calcareous nannofossil data), a lateral input (upwelling) of nutrient-rich waters onto the shelf to fuel the benthic ecosystem has to be considered. This view is supported by records of contemporaneous changes in latest Cretaceous ocean circulation that followed the latest Campanian cooling event, inclusive of a southward spread of waters of intermediate depth from high-latitudes.

Experiment Description and Results for Arrival Operations Using Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR)

NASA Technical Reports Server (NTRS)

Baxley, Brian T.; Murdoch, Jennifer L.; Swieringa, Kurt A.; Barmore, Bryan E.; Capron, William R.; Hubbs, Clay E.; Shay, Richard F.; Abbott, Terence S.

2013-01-01

The predicted increase in the number of commercial aircraft operations creates a need for improved operational efficiency. Two areas believed to offer increases in aircraft efficiency are optimized profile descents and dependent parallel runway operations. Using Flight deck Interval Management (FIM) software and procedures during these operations, flight crews can achieve by the runway threshold an interval assigned by air traffic control (ATC) behind the preceding aircraft that maximizes runway throughput while minimizing additional fuel consumption and pilot workload. This document describes an experiment where 24 pilots flew arrivals into the Dallas Fort-Worth terminal environment using one of three simulators at NASA?s Langley Research Center. Results indicate that pilots delivered their aircraft to the runway threshold within +/- 3.5 seconds of their assigned time interval, and reported low workload levels. In general, pilots found the FIM concept, procedures, speeds, and interface acceptable. Analysis of the time error and FIM speed changes as a function of arrival stream position suggest the spacing algorithm generates stable behavior while in the presence of continuous (wind) or impulse (offset) error. Concerns reported included multiple speed changes within a short time period, and an airspeed increase followed shortly by an airspeed decrease.

Factor analytic reduction of the carotid-cardiac baroreflex parameters

NASA Technical Reports Server (NTRS)

Ludwig, David A.

1989-01-01

An accepted method for measuring the responsiveness of the carotid-cardiac baroreflex to arterial pressure changes is to artificially stimulate the baroreceptors in the neck. This is accomplished by using a pressurized neck cuff which constricts and distends the carotid artery and subsequently stimulates the baroreceptors. Nine physiological responses to this type of stimulation are quantified and used as indicators of the baroreflex. Thirty male humans between the ages 27 and 46 underwent the carotid-cardiac baroreflex test. The data for the nine response parameters were analyzed by principle component factor analysis. The results of this analysis indicated that 93 percent of the total variance across all nine parameters could be explained in four dimensions. Examination of the factor loadings following an orthogonal rotation of the principle components indicated four well defined dimensions. The first two dimensions reflected location points for R-R interval and carotid distending pressure respectively. The third dimension was composed of measures reflecting the gain of the reflex. The fourth dimension was the ratio of the resting R-R interval to R-R interval during simulated hypertension. The data suggests that the analysis of all nine baroreflex parameters is redundant.

A Long-Term Dissipation of the EUV He ii (30.4 nm) Segmentation in Full-Disk Solar Images

NASA Astrophysics Data System (ADS)

Didkovsky, Leonid

2018-06-01

Some quiet-Sun days observed by the Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO) during the time interval in 2010 - 2017 were used to continue our previous analyses reported by Didkovsky and Gurman ( Solar Phys. 289, 153, 2014a) and Didkovsky, Wieman, and Korogodina ( Solar Phys. 292, 32, 2017). The analysis consists of determining and comparing spatial spectral ratios (spectral densities over some time interval) from spatial (segmentation-cell length) power spectra. The ratios were compared using modeled compatible spatial frequencies for spectra from the Extreme ultraviolet Imaging Telescope (EIT) on-board the Solar and Heliospheric Observatory (SOHO) and from AIA images. With the new AIA data added to the EIT data we analyzed previously, the whole time interval from 1996 to 2017 reported here is approximately the length of two "standard" solar cycles (SC). The spectral ratios of segmentation-cell dimension structures show a significant and steady increase with no detected indication of SC-related returns to the values that characterize the SC minima. This increase in spatial power at high spatial frequencies is interpreted as a dissipation of medium-size EUV network structures to smaller-size structures in the transition region. Each of the latest ratio changes for 2010 through 2017 spectra calculated for a number of consecutive short-term intervals has been converted into monthly mean ratio (MMR) changes. The MMR values demonstrate variable sign and magnitudes, thus confirming the solar nature of the changes. These changes do not follow a "typical" trend of instrumental degradation or a long-term activity profile from the He ii (30.4 nm) irradiance measured by the Extreme ultraviolet Spectrophotometer (ESP) either. The ESP is a channel of the Extreme ultraviolet Variability Experiment (EVE) on-board SDO.

Prolongation of the QTc interval in African children treated for falciparum malaria.

PubMed

vn Seidlein, L; Jaffar, S; Greenwood, B

1997-05-01

Antimalarial drugs can affect the heart and trigger life-threatening arrhythmias. However, little is known about the frequency with which cardiac abnormalities occur during uncomplicated attacks of malaria. Therefore, we have studied the electrocardiograms of 139 Gambian children with uncomplicated falciparum malaria who were treated with co-artemether, pyrimethamine/sulfadoxine, or chloriquine. The QTc intervals were measured on presentation, and four and eight days after treatment. No significant differences in mean QTc or heart rate were found between children in the three treatment groups on days 0, 4, or 8. After adjustment for the type of antimalarial thearapy in an analysis of variance, the mean (SD) QTc intervals on days 0, 4, and 8 were 402 (22.6), 416 (23.1), and 405 (24.3) msec, respectively. The mean QTc on day 4 was significantly longer than the mean QTc on days 0 or 8 (P < 0.01 in both cases). A quadratic line was fitted for QTc against time for each antimalarial therapy. No significant differences were found between the quadratic lines of the three groups. A weak association was found between QTc and the degree of parasitemia (r = 0.17, P = 0.04) and temperature (r = -0.23, P = 0.01) measured on day 0. The QTcs were measured in 18 children who experienced a second episode of malaria. The changes in QTc observed during second episodes were similar to those observed during the first attack. Changes in QTc in five children who developed severe malaria were similar to those found in the remaining children who did not develop severe malaria. This study indicates that the QTc interval changes during the early phase of malaria and this change is independent of the type of antimalarial therapy given.

Combined influence of adjuvant therapy and interval after surgery on peripheral CD4+ T lymphocytes in patients with esophageal squamous cell carcinoma

PubMed Central

LING, YANG; FAN, LIEYING; DONG, CHUNLEI; ZHU, JING; LIU, YONGPING; NI, YAN; ZHU, CHANGTAI; ZHANG, CHANGSONG

2010-01-01

The aim of this study was to investigate possible differences in cellular immunity between chemo- and/or radiotherapy groups during a long interval after surgery in esophageal squamous cell carcinoma (ESCC) patients. Cellular immunity was assessed as peripheral lymphocyte subsets in response to chemotherapy (CT), radiotherapy (RT) and CT+RT by flow cytometric analysis. There were 139 blood samples obtained at different time points relative to surgery from 73 patients with ESCC. The changes in the absolute and relative proportions of lymphocyte phenotypes were significant among the adjuvant therapy groups. There were significant differences in the absolute counts of CD4+ and CD8+ T cells among the interval groups, and a lower CD4/CD8 ratio was found in patients following a prolonged interval. RT alone had a profound effect on the absolute counts of CD3+, CD4+ and CD8+ T cells compared with the other groups. CD4+ T cells exhibited a decreasing trend during a long interval, leading to a prolonged T-cell imbalance after surgery. Univariate analysis revealed that the interaction of the type of adjuvant therapy and the interval after surgery was correlated only with the percentage of CD4+ T cells. The percentage of CD4+ T cells can be used as an indicator of the cellular immunity after surgery in ESCC patients. However, natural killer cells consistently remained suppressed in ESCC patients following adjuvant therapy after surgery. These findings confirm an interaction between adjuvant therapy and the interval after surgery on peripheral CD4+ T cells, and implies that adjuvant therapy may have selective influence on the cellular immunity of ESCC patients after surgery. PMID:23136603

Sub-Frequency Interval Approach in Electromechanical Impedance Technique for Concrete Structure Health Monitoring

PubMed Central

Yang, Yaowen; Divsholi, Bahador Sabet

2010-01-01

The electromechanical (EM) impedance technique using piezoelectric lead zirconate titanate (PZT) transducers for structural health monitoring (SHM) has attracted considerable attention in various engineering fields. In the conventional EM impedance technique, the EM admittance of a PZT transducer is used as a damage indicator. Statistical analysis methods such as root mean square deviation (RMSD) have been employed to associate the damage level with the changes in the EM admittance signatures, but it is difficult to determine the location of damage using such methods. This paper proposes a new approach by dividing the large frequency (30–400 kHz) range into sub-frequency intervals and calculating their respective RMSD values. The RMSD of the sub-frequency intervals (RMSD-S) will be used to study the severity and location of damage. An experiment is carried out on a real size concrete structure subjected to artificial damage. It is observed that damage close to the PZT changes the high frequency range RMSD-S significantly, while the damage far away from the PZT changes the RMSD-S in the low frequency range significantly. The relationship between the frequency range and the PZT sensing region is also presented. Finally, a damage identification scheme is proposed to estimate the location and severity of damage in concrete structures. PMID:22163548

[Autonomic nervous function in patients with vertigo--evaluation for static function, variation and dynamic change using power spectral analysis of RR intervals].

PubMed

Seki, S

1997-04-01

Power spectral analysis of RR intervals (PSA) of 94 vertiginous patients with associated autonomic nervous dysfunction (AND group), 31 patients with vertebro-basilar insufficiency (VBI group) and 25 controls were analyzed in supine and upright positions. In addition static function, variation from the supine to the upright position and dynamic change in autonomic nervous function (ANF) from the supine to the upright position were examined. Heart rate was recorded for 120 seconds in the supine and 40 seconds in the upright position. RR intervals for each 20-second period were computed using FFT (Fast Fourier Transformation), and the ratio of low frequency power (0.05-0.15 Hz) to high frequency power (0.15-0.4 Hz) (L/H) of PSA were analyzed as an index of sympathetic activity. The PSA was examined by the following three parameters; L/H at rest during the 80-second period from 20 to 100 seconds (static function), the L/H variation between each 20-second period from 0 to 160 seconds (variation) and the ratio of L/H to that in the upright position (dynamic change). The results of PSA were compared with those of pulse wave velocity (PWV) and the coefficient of variation of the RR interval (CVRR), and association between attacks of vertigo and ANF was determined. The results of static function of PSA and the results of PWV and CVRR were very similar, indicating that both methods are useful for evaluating ANF in vertiginous patients. In the AND group the variation in sympathetic activity tended to be larger in patients with sympathetic hyperfunction and parasympathetic hypofunction and in the patients with sympathetic hypofunction and parasympathetic hyperfunction resulting from PWV and CVRR, than in the controls. The dynamic change in patients with sympathetic hyperfunction and parasympathetic hypofunction resulting from PWV and CVRR was also significantly lower than that in the controls (p < 0.01). Some patients in the AND group already showed excessive sympathetic hyperfunction at rest, and changing the position from supine to upright might trigger sympathetic hypofunction, causing an attack of vertigo. The PSA results in the VBI group were similar to those in the controls, suggesting that sympathetic dysfunction did not affect VBI induced vertigo.

The effect of changes in core body temperature on the QT interval in beagle dogs: a previously ignored phenomenon, with a method for correction.

PubMed

van der Linde, H J; Van Deuren, B; Teisman, A; Towart, R; Gallacher, D J

2008-08-01

Body core temperature (Tc) changes affect the QT interval, but correction for this has not been systematically investigated. It may be important to correct QT intervals for drug-induced changes in Tc. Anaesthetized beagle dogs were artificially cooled (34.2 degrees C) or warmed (42.1 degrees C). The relationship between corrected QT intervals (QTcV; QT interval corrected according to the Van de Water formula) and Tc was analysed. This relationship was also examined in conscious dogs where Tc was increased by exercise. When QTcV intervals were plotted against changes in Tc, linear correlations were observed in all individual dogs. The slopes did not significantly differ between cooling (-14.85+/-2.08) or heating (-13.12+/-3.46) protocols. We propose a correction formula to compensate for the influence of Tc changes and standardize the QTcV duration to 37.5 degrees C: QTcVcT (QTcV corrected for changes in core temperature)=QTcV-14 (37.5 - Tc). Furthermore, cooled dogs were re-warmed (from 34.2 to 40.0 degrees C) and marked QTcV shortening (-29%) was induced. After Tc correction, using the above formula, this decrease was abolished. In these re-warmed dogs, we observed significant increases in T-wave amplitude and in serum [K(+)] levels. No arrhythmias or increase in pro-arrhythmic biomarkers were observed. In exercising dogs, the above formula completely compensated QTcV for the temperature increase. This study shows the importance of correcting QTcV intervals for changes in Tc, to avoid misleading interpretations of apparent QTcV interval changes. We recommend that all ICH S7A, conscious animal safety studies should routinely measure core body temperature and correct QTcV appropriately, if body temperature and heart rate changes are observed.

The effect of changes in core body temperature on the QT interval in beagle dogs: a previously ignored phenomenon, with a method for correction

PubMed Central

van der Linde, H J; Van Deuren, B; Teisman, A; Towart, R; Gallacher, D J

2008-01-01

Background and purpose: Body core temperature (Tc) changes affect the QT interval, but correction for this has not been systematically investigated. It may be important to correct QT intervals for drug-induced changes in Tc. Experimental approach: Anaesthetized beagle dogs were artificially cooled (34.2 °C) or warmed (42.1 °C). The relationship between corrected QT intervals (QTcV; QT interval corrected according to the Van de Water formula) and Tc was analysed. This relationship was also examined in conscious dogs where Tc was increased by exercise. Key results: When QTcV intervals were plotted against changes in Tc, linear correlations were observed in all individual dogs. The slopes did not significantly differ between cooling (−14.85±2.08) or heating (−13.12±3.46) protocols. We propose a correction formula to compensate for the influence of Tc changes and standardize the QTcV duration to 37.5 °C: QTcVcT (QTcV corrected for changes in core temperature)=QTcV–14 (37.5 – Tc). Furthermore, cooled dogs were re-warmed (from 34.2 to 40.0 °C) and marked QTcV shortening (−29%) was induced. After Tc correction, using the above formula, this decrease was abolished. In these re-warmed dogs, we observed significant increases in T-wave amplitude and in serum [K+] levels. No arrhythmias or increase in pro-arrhythmic biomarkers were observed. In exercising dogs, the above formula completely compensated QTcV for the temperature increase. Conclusions and implications: This study shows the importance of correcting QTcV intervals for changes in Tc, to avoid misleading interpretations of apparent QTcV interval changes. We recommend that all ICH S7A, conscious animal safety studies should routinely measure core body temperature and correct QTcV appropriately, if body temperature and heart rate changes are observed. PMID:18574451

Continuous inventories and the components of change

Treesearch

Frnacis A. Roesch

2004-01-01

The consequences of conducting a continuous inventory that utilizes measurements on overlapping temporal intervals of varying length on compatible estimation systems for the components of growth are explored. The time interpenetrating sample design of the USDA Forest Service Forest Inventory and Analysis Program is used as an example. I show why estimation of the...

Meta-Analyses of Diagnostic Accuracy in Imaging Journals: Analysis of Pooling Techniques and Their Effect on Summary Estimates of Diagnostic Accuracy.

PubMed

McGrath, Trevor A; McInnes, Matthew D F; Korevaar, Daniël A; Bossuyt, Patrick M M

2016-10-01

Purpose To determine whether authors of systematic reviews of diagnostic accuracy studies published in imaging journals used recommended methods for meta-analysis, and to evaluate the effect of traditional methods on summary estimates of sensitivity and specificity. Materials and Methods Medline was searched for published systematic reviews that included meta-analysis of test accuracy data limited to imaging journals published from January 2005 to May 2015. Two reviewers independently extracted study data and classified methods for meta-analysis as traditional (univariate fixed- or random-effects pooling or summary receiver operating characteristic curve) or recommended (bivariate model or hierarchic summary receiver operating characteristic curve). Use of methods was analyzed for variation with time, geographical location, subspecialty, and journal. Results from reviews in which study authors used traditional univariate pooling methods were recalculated with a bivariate model. Results Three hundred reviews met the inclusion criteria, and in 118 (39%) of those, authors used recommended meta-analysis methods. No change in the method used was observed with time (r = 0.54, P = .09); however, there was geographic (χ(2) = 15.7, P = .001), subspecialty (χ(2) = 46.7, P < .001), and journal (χ(2) = 27.6, P < .001) heterogeneity. Fifty-one univariate random-effects meta-analyses were reanalyzed with the bivariate model; the average change in the summary estimate was -1.4% (P < .001) for sensitivity and -2.5% (P < .001) for specificity. The average change in width of the confidence interval was 7.7% (P < .001) for sensitivity and 9.9% (P ≤ .001) for specificity. Conclusion Recommended methods for meta-analysis of diagnostic accuracy in imaging journals are used in a minority of reviews; this has not changed significantly with time. Traditional (univariate) methods allow overestimation of diagnostic accuracy and provide narrower confidence intervals than do recommended (bivariate) methods. (©) RSNA, 2016 Online supplemental material is available for this article.

PK/PD Modelling of the QT Interval: a Step Towards Defining the Translational Relationship Between In Vitro, Awake Beagle Dogs, and Humans.

PubMed

Marostica, Eleonora; Van Ammel, Karel; Teisman, Ard; Gallacher, David; Van Bocxlaer, Jan; De Ridder, Filip; Boussery, Koen; Vermeulen, An

2016-07-01

Inhibiting the human ether-a-go-go-related gene (hERG)-encoded potassium ion channel is positively correlated with QT-interval prolongation in vivo, which is considered a risk factor for the occurrence of Torsades de Pointes (TdP). A pharmacokinetic/pharmacodynamic model was developed for four compounds that reached the clinic, to relate drug-induced QT-interval change in awake dogs and humans and to derive a translational scaling factor a 1. Overall, dogs were more sensitive than humans to QT-interval change, an a 1 of 1.5 was found, and a 10% current inhibition in vitro produced a higher percent QT-interval change in dogs as compared to humans. The QT-interval changes in dogs were predictive for humans. In vitro and in vivo information could reliably describe the effects in humans. Robust translational knowledge is likely to reduce the need for expensive thorough QT studies; therefore, expanding this work to more compounds is recommended.

Electrocardiographic Predictors of Long-Term Cardiac Pacing Dependency Following Transcatheter Aortic Valve Implantation.

PubMed

Naveh, Sivan; Perlman, Gidon Y; Elitsur, Yair; Planer, David; Gilon, Dan; Leibowitz, David; Lotan, Chaim; Danenberg, Haim; Alcalai, Ronny

2017-02-01

Conduction disorders requiring permanent pacemaker (PPM) implantation are a known complication of transcatheter aortic valve implantation (TAVI). Indications for permanent pacing in this setting are still controversial. The study aim was to characterize the natural history of conduction disorders related to TAVI, and to identify predictors for long-term pacing dependency. Consecutive patients who underwent TAVI were included in this prospective observational study. The conduction system was investigated by reviewing 12-lead ECGs during hospitalization and up to 1-year follow-up and by analyzing pacemaker interrogation data. Multivariate analysis was performed in order to identify independent predictors for pacemaker dependency. Of 110 patients included in the analysis, 38 (34.5%) underwent PPM implantation. Of those, 26 (68.4%) had a long-term pacing dependency (required PPM), while 12 (31.6%) did not (not-required PPM). Logistic regression revealed that baseline RBBB (P = 0.01, OR = 18.0), baseline PR interval (P = 0.019, OR = 1.14), post-TAVI PR interval and the change in PR interval from baseline (P < 0.001 for both, OR = 1.17 for each 10 milliseconds increment) were independent predictors for long-term pacing dependency. A PR interval increment of greater than 28 milliseconds had the best accuracy in predicting pacemaker dependency. Increased pre- and postprocedural PR intervals and pre-existing RBBB are reliable predictors for long-term PPM dependency, while left bundle branch block or QRS width are misleading factors. Our study suggests that the decision for implanting PPM after TAVI should be based mostly on the prolongation of the PR interval. © 2016 Wiley Periodicals, Inc.

Including land cover change in analysis of greenness trends using all available Landsat 5, 7, and 8 images: A case study from Guangzhou, China (2000–2014)

USGS Publications Warehouse

Zhu, Zhe; Fu, Yingchun; Woodcock, Curtis; Olofsson, Pontus; Vogelmann, James; Holden, Christopher; Wang, Min; Dai, Shu; Yu, Yang

2016-01-01

An assessment of the consistency of surface reflectance from Landsat 8 with past Landsat sensors indicates biases in the visible bands of Landsat 8, especially the blue band. Landsat 8 NDVI values were found to have a larger bias than the EVI values; therefore, EVI was used in the analysis of greenness trends for Guangzhou. In spite of massive amounts of development in Guangzhou from 2000 to 2014, greenness was found to increase, mostly as a result of gradual change. Comparison of the greening magnitudes estimated from the approach presented here and a Simple Linear Trend (SLT) method indicated large differences for certain time intervals as the SLT method does not include consideration for abrupt land cover changes. Overall, this analysis demonstrates the importance of considering land cover change when analyzing trends in greenness from satellite time series in areas where land cover change is common.

Predictive value of preoperative electrocardiography for perioperative cardiovascular outcomes in patients undergoing noncardiac, nonvascular surgery.

PubMed

Biteker, Murat; Duman, Dursun; Tekkeşin, Ahmet Ilker

2012-08-01

The utility of routine preoperative electrocardiography (ECG) for assessing perioperative cardiovascular risk in patients undergoing noncardiac, nonvascular surgery (NCNVS) is unclear. There would be an association between preoperative ECG and perioperative cardiovascular outcomes in patients undergoing NCNVS. A total of 660 patients undergoing NCNVS were prospectively evaluated. Patients age >18 years who underwent an elective, nonday case, open surgical procedure were enrolled. Troponin I concentrations and 12-lead ECG were evaluated the day before surgery, immediately after surgery, and on the first 5 postoperative days. Preoperative ECG showing atrial fibrillation, left or right bundle branch block, left ventricular hypertrophy, frequent premature ventricular complexes, pacemaker rhythm, Q-wave, ST-segment changes, or sinus tachycardia or bradycardia were classified as abnormal. The patients were followed up during hospitalization and were evaluated for the presence of perioperative cardiovascular events (PCE). Eighty patients (12.1%) experienced PCE. Patients with abnormal ECG findings had a greater incidence of PCE than those with normal ECG results (16% vs 6.4%; P < 0.001). Mean QTc interval was significantly longer in the patients who had PCE (436.6 ± 31.4 vs 413.3 ± 16.7 ms; P < 0.001). Univariate analysis showed a significant association between preoperative atrial fibrillation, pacemaker rhythm, ST-segment changes, QTc prolongation, and in-hospital PCE. However, only QTc prolongation (odds ratio: 1.15, 95% confidence interval: 1.06-1.2, P < 0.001) was an independent predictor of PCE according to the multivariate analysis. Every 10-ms increase in QTc interval was related to a 13% increase for PCE. Prolongation of the QTc interval on the preoperative ECG was related with PCE in patients undergoing NCNVS. © 2011 Wiley Periodicals, Inc.

Cardiac interbeat interval dynamics from childhood to senescence : comparison of conventional and new measures based on fractals and chaos theory

NASA Technical Reports Server (NTRS)

Pikkujamsa, S. M.; Makikallio, T. H.; Sourander, L. B.; Raiha, I. J.; Puukka, P.; Skytta, J.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.

1999-01-01

BACKGROUND: New methods of R-R interval variability based on fractal scaling and nonlinear dynamics ("chaos theory") may give new insights into heart rate dynamics. The aims of this study were to (1) systematically characterize and quantify the effects of aging from early childhood to advanced age on 24-hour heart rate dynamics in healthy subjects; (2) compare age-related changes in conventional time- and frequency-domain measures with changes in newly derived measures based on fractal scaling and complexity (chaos) theory; and (3) further test the hypothesis that there is loss of complexity and altered fractal scaling of heart rate dynamics with advanced age. METHODS AND RESULTS: The relationship between age and cardiac interbeat (R-R) interval dynamics from childhood to senescence was studied in 114 healthy subjects (age range, 1 to 82 years) by measurement of the slope, beta, of the power-law regression line (log power-log frequency) of R-R interval variability (10(-4) to 10(-2) Hz), approximate entropy (ApEn), short-term (alpha(1)) and intermediate-term (alpha(2)) fractal scaling exponents obtained by detrended fluctuation analysis, and traditional time- and frequency-domain measures from 24-hour ECG recordings. Compared with young adults (<40 years old, n=29), children (<15 years old, n=27) showed similar complexity (ApEn) and fractal correlation properties (alpha(1), alpha(2), beta) of R-R interval dynamics despite lower spectral and time-domain measures. Progressive loss of complexity (decreased ApEn, r=-0.69, P<0.001) and alterations of long-term fractal-like heart rate behavior (increased alpha(2), r=0.63, decreased beta, r=-0.60, P<0.001 for both) were observed thereafter from middle age (40 to 60 years, n=29) to old age (>60 years, n=29). CONCLUSIONS: Cardiac interbeat interval dynamics change markedly from childhood to old age in healthy subjects. Children show complexity and fractal correlation properties of R-R interval time series comparable to those of young adults, despite lower overall heart rate variability. Healthy aging is associated with R-R interval dynamics showing higher regularity and altered fractal scaling consistent with a loss of complex variability.

The "Chaos Theory" and nonlinear dynamics in heart rate variability analysis: does it work in short-time series in patients with coronary heart disease?

PubMed

Krstacic, Goran; Krstacic, Antonija; Smalcelj, Anton; Milicic, Davor; Jembrek-Gostovic, Mirjana

2007-04-01

Dynamic analysis techniques may quantify abnormalities in heart rate variability (HRV) based on nonlinear and fractal analysis (chaos theory). The article emphasizes clinical and prognostic significance of dynamic changes in short-time series applied on patients with coronary heart disease (CHD) during the exercise electrocardiograph (ECG) test. The subjects were included in the series after complete cardiovascular diagnostic data. Series of R-R and ST-T intervals were obtained from exercise ECG data after sampling digitally. The range rescaled analysis method determined the fractal dimension of the intervals. To quantify fractal long-range correlation's properties of heart rate variability, the detrended fluctuation analysis technique was used. Approximate entropy (ApEn) was applied to quantify the regularity and complexity of time series, as well as unpredictability of fluctuations in time series. It was found that the short-term fractal scaling exponent (alpha(1)) is significantly lower in patients with CHD (0.93 +/- 0.07 vs 1.09 +/- 0.04; P < 0.001). The patients with CHD had higher fractal dimension in each exercise test program separately, as well as in exercise program at all. ApEn was significant lower in CHD group in both RR and ST-T ECG intervals (P < 0.001). The nonlinear dynamic methods could have clinical and prognostic applicability also in short-time ECG series. Dynamic analysis based on chaos theory during the exercise ECG test point out the multifractal time series in CHD patients who loss normal fractal characteristics and regularity in HRV. Nonlinear analysis technique may complement traditional ECG analysis.

A statistical note on the redundancy of nine standard baroreflex parameters

NASA Technical Reports Server (NTRS)

Ludwig, David A.; Convertino, Victor A.

1991-01-01

An accepted method for measuring the responsiveness of the carotid-cardiac baroreflex to arterial pressure changes is to artificially stimulate the baroreceptors in the neck with a pressurized neck chamber. Nine physiological responses to this type of stimulation are quantified and used as indicators of the baroreflex response function. Thirty male humans between the ages of 27 and 46 underwent the carotid-cardiac baroreflex test. The data for the nine response parameters were analyzed by principle component factor analysis. The results indicated that 92.5 percent of the total variance across all nine parameters could be explained in four dimensions. The first two dimensions reflected location points for R-R interval and carotid distending pressure, respectively. The third factor was composed of measures reflecting the gain (responsiveness) of the reflex. The fourth dimension was the ratio of baseline R-R interval to the maximal R-R interval response during simulated hypertension. The data suggest that the analysis of all nine baroreflex parameters is likely to be redundant and researchers should account for these redundancies either in their analyses or conclusions.

Using operations research to plan improvement of the transport of critically ill patients.

PubMed

Chen, Jing; Awasthi, Anjali; Shechter, Steven; Atkins, Derek; Lemke, Linda; Fisher, Les; Dodek, Peter

2013-01-01

Operations research is the application of mathematical modeling, statistical analysis, and mathematical optimization to understand and improve processes in organizations. The objective of this study was to illustrate how the methods of operations research can be used to identify opportunities to reduce the absolute value and variability of interfacility transport intervals for critically ill patients. After linking data from two patient transport organizations in British Columbia, Canada, for all critical care transports during the calendar year 2006, the steps for transfer of critically ill patients were tabulated into a series of time intervals. Statistical modeling, root-cause analysis, Monte Carlo simulation, and sensitivity analysis were used to test the effect of changes in component intervals on overall duration and variation of transport times. Based on quality improvement principles, we focused on reducing the 75th percentile and standard deviation of these intervals. We analyzed a total of 3808 ground and air transports. Constraining time spent by transport personnel at sending and receiving hospitals was projected to reduce the total time taken by 33 minutes with as much as a 20% reduction in standard deviation of these transport intervals in 75% of ground transfers. Enforcing a policy of requiring acceptance of patients who have life- or limb-threatening conditions or organ failure was projected to reduce the standard deviation of air transport time by 63 minutes and the standard deviation of ground transport time by 68 minutes. Based on findings from our analyses, we developed recommendations for technology renovation, personnel training, system improvement, and policy enforcement. Use of the tools of operations research identifies opportunities for improvement in a complex system of critical care transport.

Changes in crash risk following re-timing of traffic signal change intervals.

PubMed

Retting, Richard A; Chapline, Janella F; Williams, Allan F

2002-03-01

More than I million motor vehicle crashes occur annually at signalized intersections in the USA. The principal method used to prevent crashes associated with routine changes in signal indications is employment of a traffic signal change interval--a brief yellow and all-red period that follows the green indication. No universal practice exists for selecting the duration of change intervals, and little is known about the influence of the duration of the change interval on crash risk. The purpose of this study was to estimate potential crash effects of modifying the duration of traffic signal change intervals to conform with values associated with a proposed recommended practice published by the Institute of Transportation Engineers. A sample of 122 intersections was identified and randomly assigned to experimental and control groups. Of 51 eligible experimental sites, 40 (78%) needed signal timing changes. For the 3-year period following implementation of signal timing changes, there was an 8% reduction in reportable crashes at experimental sites relative to those occurring at control sites (P = 0.08). For injury crashes, a 12% reduction at experimental sites relative to those occurring at control sites was found (P = 0.03). Pedestrian and bicycle crashes at experimental sites decreased 37% (P = 0.03) relative to controls. Given these results and the relatively low cost of re-timing traffic signals, modifying the duration of traffic signal change intervals to conform with values associated with the Institute of Transportation Engineers' proposed recommended practice should be strongly considered by transportation agencies to reduce the frequency of urban motor vehicle crashes.

Dissimilar Physiological and Perceptual Responses Between Sprint Interval Training and High-Intensity Interval Training.

PubMed

Wood, Kimberly M; Olive, Brittany; LaValle, Kaylyn; Thompson, Heather; Greer, Kevin; Astorino, Todd A

2016-01-01

High-intensity interval training (HIIT) and sprint interval training (SIT) elicit similar cardiovascular and metabolic adaptations vs. endurance training. No study, however, has investigated acute physiological changes during HIIT vs. SIT. This study compared acute changes in heart rate (HR), blood lactate concentration (BLa), oxygen uptake (VO2), affect, and rating of perceived exertion (RPE) during HIIT and SIT. Active adults (4 women and 8 men, age = 24.2 ± 6.2 years) initially performed a VO2max test to determine workload for both sessions on the cycle ergometer, whose order was randomized. Sprint interval training consisted of 8 bouts of 30 seconds of all-out cycling at 130% of maximum Watts (Wmax). High-intensity interval training consisted of eight 60-second bouts at 85% Wmax. Heart rate, VO2, BLa, affect, and RPE were continuously assessed throughout exercise. Repeated-measures analysis of variance revealed a significant difference between HIIT and SIT for VO2 (p < 0.001), HR (p < 0.001), RPE (p = 0.03), and BLa (p = 0.049). Conversely, there was no significant difference between regimens for affect (p = 0.12). Energy expenditure was significantly higher (p = 0.02) in HIIT (209.3 ± 40.3 kcal) vs. SIT (193.5 ± 39.6 kcal). During HIIT, subjects burned significantly more calories and reported lower perceived exertion than SIT. The higher VO2 and lower BLa in HIIT vs. SIT reflected dissimilar metabolic perturbation between regimens, which may elicit unique long-term adaptations. If an individual is seeking to burn slightly more calories, maintain a higher oxygen uptake, and perceive less exertion during exercise, HIIT is the recommended routine.

Transformation of social networks in the late pre-Hispanic US Southwest.

PubMed

Mills, Barbara J; Clark, Jeffery J; Peeples, Matthew A; Haas, W R; Roberts, John M; Hill, J Brett; Huntley, Deborah L; Borck, Lewis; Breiger, Ronald L; Clauset, Aaron; Shackley, M Steven

2013-04-09

The late pre-Hispanic period in the US Southwest (A.D. 1200-1450) was characterized by large-scale demographic changes, including long-distance migration and population aggregation. To reconstruct how these processes reshaped social networks, we compiled a comprehensive artifact database from major sites dating to this interval in the western Southwest. We combine social network analysis with geographic information systems approaches to reconstruct network dynamics over 250 y. We show how social networks were transformed across the region at previously undocumented spatial, temporal, and social scales. Using well-dated decorated ceramics, we track changes in network topology at 50-y intervals to show a dramatic shift in network density and settlement centrality from the northern to the southern Southwest after A.D. 1300. Both obsidian sourcing and ceramic data demonstrate that long-distance network relationships also shifted from north to south after migration. Surprisingly, social distance does not always correlate with spatial distance because of the presence of network relationships spanning long geographic distances. Our research shows how a large network in the southern Southwest grew and then collapsed, whereas networks became more fragmented in the northern Southwest but persisted. The study also illustrates how formal social network analysis may be applied to large-scale databases of material culture to illustrate multigenerational changes in network structure.

Regression to the Mean in SYMPLICITY HTN-3: Implications for Design and Reporting of Future Trials.

PubMed

Pocock, Stuart J; Bakris, George; Bhatt, Deepak L; Brar, Sandeep; Fahy, Martin; Gersh, Bernard J

2016-11-01

Regression to the mean (RTM) describes the tendency for an extreme measurement on 1 occasion to become less extreme when measured again. RTM may affect clinical trial data interpretation when the outcome measure has high variability. We investigated RTM in the SYMPLICITY HTN-3 (Renal Denervation in Patients With Uncontrolled Hypertension) trial of renal denervation versus a sham procedure. Analysis of covariance was performed on the 6-month change in systolic blood pressure, estimating a mean treatment difference of -4.11 mm Hg (95% confidence interval: -8.44 to 0.22 mm Hg; p = 0.064), which was similar to the unadjusted difference but with a smaller confidence interval. RTM occurred in both arms, but it had a negligible effect on the observed treatment difference. A second example concerns changes in hemoglobin A1c in a nonrandomized study. These findings emphasize the importance of incorporating RTM and analysis of covariance into the design and reporting of clinical studies of how treatments affect time changes in quantitative outcomes. (Renal Denervation in Patients With Uncontrolled Hypertension [SYMPLICITY HTN-3]; NCT01418261). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Transformation of social networks in the late pre-Hispanic US Southwest

PubMed Central

Mills, Barbara J.; Clark, Jeffery J.; Peeples, Matthew A.; Haas, W. R.; Roberts, John M.; Hill, J. Brett; Huntley, Deborah L.; Borck, Lewis; Breiger, Ronald L.; Clauset, Aaron; Shackley, M. Steven

2013-01-01

The late pre-Hispanic period in the US Southwest (A.D. 1200–1450) was characterized by large-scale demographic changes, including long-distance migration and population aggregation. To reconstruct how these processes reshaped social networks, we compiled a comprehensive artifact database from major sites dating to this interval in the western Southwest. We combine social network analysis with geographic information systems approaches to reconstruct network dynamics over 250 y. We show how social networks were transformed across the region at previously undocumented spatial, temporal, and social scales. Using well-dated decorated ceramics, we track changes in network topology at 50-y intervals to show a dramatic shift in network density and settlement centrality from the northern to the southern Southwest after A.D. 1300. Both obsidian sourcing and ceramic data demonstrate that long-distance network relationships also shifted from north to south after migration. Surprisingly, social distance does not always correlate with spatial distance because of the presence of network relationships spanning long geographic distances. Our research shows how a large network in the southern Southwest grew and then collapsed, whereas networks became more fragmented in the northern Southwest but persisted. The study also illustrates how formal social network analysis may be applied to large-scale databases of material culture to illustrate multigenerational changes in network structure. PMID:23530201

Detection of QT prolongation using a novel ECG analysis algorithm applying intelligent automation: Prospective blinded evaluation using the Cardiac Safety Research Consortium ECG database

PubMed Central

Green, Cynthia L.; Kligfield, Paul; George, Samuel; Gussak, Ihor; Vajdic, Branislav; Sager, Philip; Krucoff, Mitchell W.

2013-01-01

Background The Cardiac Safety Research Consortium (CSRC) provides both “learning” and blinded “testing” digital ECG datasets from thorough QT (TQT) studies annotated for submission to the US Food and Drug Administration (FDA) to developers of ECG analysis technologies. This manuscript reports the first results from a blinded “testing” dataset that examines Developer re-analysis of original Sponsor-reported core laboratory data. Methods 11,925 anonymized ECGs including both moxifloxacin and placebo arms of a parallel-group TQT in 191 subjects were blindly analyzed using a novel ECG analysis algorithm applying intelligent automation. Developer measured ECG intervals were submitted to CSRC for unblinding, temporal reconstruction of the TQT exposures, and statistical comparison to core laboratory findings previously submitted to FDA by the pharmaceutical sponsor. Primary comparisons included baseline-adjusted interval measurements, baseline- and placebo-adjusted moxifloxacin QTcF changes (ddQTcF), and associated variability measures. Results Developer and Sponsor-reported baseline-adjusted data were similar with average differences less than 1 millisecond (ms) for all intervals. Both Developer and Sponsor-reported data demonstrated assay sensitivity with similar ddQTcF changes. Average within-subject standard deviation for triplicate QTcF measurements was significantly lower for Developer than Sponsor-reported data (5.4 ms and 7.2 ms, respectively; p<0.001). Conclusion The virtually automated ECG algorithm used for this analysis produced similar yet less variable TQT results compared to the Sponsor-reported study, without the use of a manual core laboratory. These findings indicate CSRC ECG datasets can be useful for evaluating novel methods and algorithms for determining QT/QTc prolongation by drugs. While the results should not constitute endorsement of specific algorithms by either CSRC or FDA, the value of a public domain digital ECG warehouse to provide prospective, blinded comparisons of ECG technologies applied for QT/QTc measurement is illustrated. PMID:22424006

AnalyzeHOLE - An Integrated Wellbore Flow Analysis Tool

USGS Publications Warehouse

Halford, Keith

2009-01-01

Conventional interpretation of flow logs assumes that hydraulic conductivity is directly proportional to flow change with depth. However, well construction can significantly alter the expected relation between changes in fluid velocity and hydraulic conductivity. Strong hydraulic conductivity contrasts between lithologic intervals can be masked in continuously screened wells. Alternating intervals of screen and blank casing also can greatly complicate the relation between flow and hydraulic properties. More permeable units are not necessarily associated with rapid fluid-velocity increases. Thin, highly permeable units can be misinterpreted as thick and less permeable intervals or not identified at all. These conditions compromise standard flow-log interpretation because vertical flow fields are induced near the wellbore. AnalyzeHOLE, an integrated wellbore analysis tool for simulating flow and transport in wells and aquifer systems, provides a better alternative for simulating and evaluating complex well-aquifer system interaction. A pumping well and adjacent aquifer system are simulated with an axisymmetric, radial geometry in a two-dimensional MODFLOW model. Hydraulic conductivities are distributed by depth and estimated with PEST by minimizing squared differences between simulated and measured flows and drawdowns. Hydraulic conductivity can vary within a lithology but variance is limited with regularization. Transmissivity of the simulated system also can be constrained to estimates from single-well, pumping tests. Water-quality changes in the pumping well are simulated with simple mixing models between zones of differing water quality. These zones are differentiated by backtracking thousands of particles from the well screens with MODPATH. An Excel spreadsheet is used to interface the various components of AnalyzeHOLE by (1) creating model input files, (2) executing MODFLOW, MODPATH, PEST, and supporting FORTRAN routines, and (3) importing and graphically displaying pertinent results.

Determinants of preterm birth rates in Canada from 1981 through 1983 and from 1992 through 1994.

PubMed

Joseph, K S; Kramer, M S; Marcoux, S; Ohlsson, A; Wen, S W; Allen, A; Platt, R

1998-11-12

The rates of preterm birth have increased in many countries, including Canada, over the past 20 years. However, the factors underlying the increase are poorly understood. We used data from the Statistics Canada live-birth and stillbirth data bases to determine the effects of changes in the frequency of multiple births, registration of births occurring very early in gestation, patterns of obstetrical intervention, and use of ultrasonographic dating of gestational age on the rates of preterm birth in Canada from 1981 through 1983 and from 1992 through 1994. All births in 9 of the 12 provinces and territories of Canada were included. Logistic-regression analysis and Poisson regression analysis were used to estimate changes between the two three-year periods, after adjustment for the above-mentioned determinants of the likelihood of preterm births. Preterm births increased from 6.3 percent of live births in 1981 through 1983 to 6.8 percent in 1992 through 1994, a relative increase of 9 percent (95 percent confidence interval, 7 to 10 percent). Among singleton births, preterm births increased by 5 percent (95 percent confidence interval, 3 to 6 percent). Multiple births increased from 1.9 percent to 2.1 percent of all live births; the rates of preterm birth among live births resulting from multiple gestations increased by 25 percent (95 percent confidence interval, 21 to 28 percent). Adjustment for the determinants of the likelihood of preterm birth reduced the increase in the rate of preterm birth to 3 percent among all live births and 1 percent among singleton births. The recent increase in preterm births in Canada is largely attributable to changes in the frequency of multiple births, obstetrical intervention, and the use of ultrasound-based estimates of gestational age.

Two-year analysis for predicting renal function and contralateral hypertrophy after robot-assisted partial nephrectomy: A three-dimensional segmentation technology study.

PubMed

Kim, Dae Keun; Jang, Yujin; Lee, Jaeseon; Hong, Helen; Kim, Ki Hong; Shin, Tae Young; Jung, Dae Chul; Choi, Young Deuk; Rha, Koon Ho

2015-12-01

To analyze long-term changes in both kidneys, and to predict renal function and contralateral hypertrophy after robot-assisted partial nephrectomy. A total of 62 patients underwent robot-assisted partial nephrectomy, and renal parenchymal volume was calculated using three-dimensional semi-automatic segmentation technology. Patients were evaluated within 1 month preoperatively, and postoperatively at 6 months, 1 year and continued up to 2-year follow up. Linear regression models were used to identify the factors predicting variables that correlated with estimated glomerular filtration rate changes and contralateral hypertrophy 2 years after robot-assisted partial nephrectomy. The median global estimated glomerular filtration rate changes were -10.4%, -11.9%, and -2.4% at 6 months, 1 and 2 years post-robot-assisted partial nephrectomy, respectively. The ipsilateral kidney median parenchymal volume changes were -24%, -24.4%, and -21% at 6 months, 1 and 2 years post-robot-assisted partial nephrectomy, respectively. The contralateral renal volume changes were 2.3%, 9.6% and 12.9%, respectively. On multivariable linear analysis, preoperative estimated glomerular filtration rate was the best predictive factor for global estimated glomerular filtration rate change on 2 years post-robot-assisted partial nephrectomy (B -0.452; 95% confidence interval -0.84 to -0.14; P = 0.021), whereas the parenchymal volume loss rate (B -0.43; 95% confidence interval -0.89 to -0.15; P = 0.017) and tumor size (B 5.154; 95% confidence interval -0.11 to 9.98; P = 0.041) were the significant predictive factors for the degree of contralateral renal hypertrophy on 2 years post-robot-assisted partial nephrectomy. Preoperative estimated glomerular filtration rate significantly affects post-robot-assisted partial nephrectomy renal function. Renal mass size and renal parenchyma volume loss correlates with compensatory hypertrophy of the contralateral kidney. Contralateral hypertrophy of the renal parenchyma compensates for the functional loss of the ipsilateral kidney. © 2015 The Japanese Urological Association.

Effects of an Extended Cage-change Interval on Ammonia Levels and Reproduction in Mongolian Gerbils (Meriones unguiculatus).

PubMed

McCullagh, Elizabeth A; McCullagh, Peter; Klug, Achim; Leszczynski, Jori K; Fong, Derek L

2017-11-01

Prompted by the cage cleanliness of Mongolian gerbils (Meriones unguiculatus), we evaluated a prolonged cage-change interval. We compared the effects of a 2-wk and 6-wk cage-change schedule on ammonia levels, temperature, humidity, and reproductive performance in breeding pairs housed in IVC. We hypothesized that ammonia levels would remain below our threshold for cage changing and that reproductive performance would not be affected. Although ammonia levels increased over time, they remained low (less than 5 ppm) over the 6-wk period. In addition, the 6-wk cage-change interval did not significantly influence reproductive parameters, such as average pup weaning weight, number of litters, and number of pups per litter. We conclude that an extended cage-change interval (6-wk) can be used for gerbils without significant increases in intracage ammonia levels or effects on reproduction.

A subharmonic dynamical bifurcation during in vitro epileptiform activity

NASA Astrophysics Data System (ADS)

Perez Velazquez, Jose L.; Khosravani, Houman

2004-06-01

Epileptic seizures are considered to result from a sudden change in the synchronization of firing neurons in brain neural networks. We have used an in vitro model of status epilepticus (SE) to characterize dynamical regimes underlying the observed seizure-like activity. Time intervals between spikes or bursts were used as the variable to construct first-return interpeak or interburst interval plots, for studying neuronal population activity during the transition to seizure, as well as within seizures. Return maps constructed for a brief epoch before seizures were used for approximating the local system dynamics during that time window. Analysis of the first-return maps suggests that intermittency is a dynamical regime underlying the observed epileptic activity. This type of analysis may be useful for understanding the collective dynamics of neuronal populations in the normal and pathological brain.

Crossover transition in the fluctuation of Internet

NASA Astrophysics Data System (ADS)

Qian, Jiang-Hai

2018-06-01

The inconsistent fluctuation behavior of Internet predicted by preferential attachment(PA) and Gibrat's law requires empirical investigations on the actual system. By using the interval-tunable Gibrat's law statistics, we find the actual fluctuation, characterized by the conditional standard deviation of the degree growth rate, changes with the interval length and displays a crossover transition from PA type to Gibrat's law type, which has not yet been captured by any previous models. We characterize the transition dynamics quantitatively and determine the applicative range of PA and Gibrat's law. The correlation analysis indicates the crossover transition may be attributed to the accumulative correlation between the internal links.

The Validity of Left Ventricular Mass as a Surrogate End Point for All-Cause and Cardiovascular Mortality Outcomes in People With CKD: A Systematic Review and Meta-analysis.

PubMed

Badve, Sunil V; Palmer, Suetonia C; Strippoli, Giovanni F M; Roberts, Matthew A; Teixeira-Pinto, Armando; Boudville, Neil; Cass, Alan; Hawley, Carmel M; Hiremath, Swapnil S; Pascoe, Elaine M; Perkovic, Vlado; Whalley, Gillian A; Craig, Jonathan C; Johnson, David W

2016-10-01

Left ventricular mass (LVM) is a widely used surrogate end point in randomized trials involving people with chronic kidney disease (CKD) because treatment-induced LVM reductions are assumed to lower cardiovascular risk. The aim of this study was to assess the validity of LVM as a surrogate end point for all-cause and cardiovascular mortality in CKD. Systematic review and meta-analysis. Participants with any stages of CKD. Randomized controlled trials with 3 or more months' follow-up that reported LVM data. Any pharmacologic or nonpharmacologic intervention. The surrogate outcome of interest was LVM change from baseline to last measurement, and clinical outcomes of interest were all-cause and cardiovascular mortality. Standardized mean differences (SMDs) of LVM change and relative risk for mortality were estimated using pairwise random-effects meta-analysis. Correlations between surrogate and clinical outcomes were summarized across all interventions combined using bivariate random-effects Bayesian models, and 95% credible intervals were computed. 73 trials (6,732 participants) covering 25 intervention classes were included in the meta-analysis. Overall, risk of bias was uncertain or high. Only 3 interventions reduced LVM: erythropoiesis-stimulating agents (9 trials; SMD, -0.13; 95% CI, -0.23 to -0.03), renin-angiotensin-aldosterone system inhibitors (13 trials; SMD, -0.28; 95% CI, -0.45 to -0.12), and isosorbide mononitrate (2 trials; SMD, -0.43; 95% CI, -0.72 to -0.14). All interventions had uncertain effects on all-cause and cardiovascular mortality. There were weak and imprecise associations between the effects of interventions on LVM change and all-cause (32 trials; 5,044 participants; correlation coefficient, 0.28; 95% credible interval, -0.13 to 0.59) and cardiovascular mortality (13 trials; 2,327 participants; correlation coefficient, 0.30; 95% credible interval, -0.54 to 0.76). Limited long-term data, suboptimal quality of included studies. There was no clear and consistent association between intervention-induced LVM change and mortality. Evidence for LVM as a valid surrogate end point in CKD is currently lacking. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Psychophysiological correlates of relaxation induced by standard autogenic training.

PubMed

Mishima, N; Kubota, S; Nagata, S

1999-01-01

The present study aimed to determine the psychophysiological changes induced in subjects by standard autogenic training (AT). Physiological measurements were taken under strict experimental conditions. Thirty-one healthy students were divided randomly into two groups: the AT group and the control group. In the first session, the physiological variables were measured for all students before and after all were asked to relax in their own way. The AT group were then taught AT for 3 months, after which time the measurements were repeated. In the second session, the AT group practised the standard AT exercise, while the control group repeated their own form of simple relaxation. Electrocardiogram, plethysmogram (PTG) and blood pressure (BP) were measured while the students carried out a breathing rate of 15 cycles/min. The R-R intervals and BP were analysed by an autoregressive model for spectral analysis, and the data were compared by repeated-measures ANOVA. The AT group had a significant increase in the mean R-R interval and a significant decrease in the baseline deflection of the PTG in the second session. There were no significant changes in sympathetic activity except for the change in the PTG, although low frequency amplitude of systolic BP decreased slightly. AT was found to induce significant changes that were independent of respiration in healthy students, although paced breathing might have operated as a mental stress. The increase in mean R-R interval and the decrease in baseline deflection of the PTG were the most robust correlates of AT.

Orbital period variation study of the low-mass Algol eclipsing binary AI Draconis

NASA Astrophysics Data System (ADS)

Hanna, Magdy A.

2013-06-01

Orbital period changes for the Algol-type eclipsing binary AI Dra were studied based on the analysis of its observed times of light minimum. The period variation showed cyclic changes in the interval from JD. ≈ 24 36000 to JD. ≈ 24 47500 and a secular period increase rate (dP/dt = 2.44 × 10-7 d/year) starting from JD. ≈ 24 48500 up to 24 55262, in a time scale equals to 5 × 106 year.

Bootstrap Confidence Intervals for Ordinary Least Squares Factor Loadings and Correlations in Exploratory Factor Analysis

ERIC Educational Resources Information Center

Zhang, Guangjian; Preacher, Kristopher J.; Luo, Shanhong

2010-01-01

This article is concerned with using the bootstrap to assign confidence intervals for rotated factor loadings and factor correlations in ordinary least squares exploratory factor analysis. Coverage performances of "SE"-based intervals, percentile intervals, bias-corrected percentile intervals, bias-corrected accelerated percentile…

Linear and volumetric dimensional changes of injection-molded PMMA denture base resins.

PubMed

El Bahra, Shadi; Ludwig, Klaus; Samran, Abdulaziz; Freitag-Wolf, Sandra; Kern, Matthias

2013-11-01

The aim of this study was to evaluate the linear and volumetric dimensional changes of six denture base resins processed by their corresponding injection-molding systems at 3 time intervals of water storage. Two heat-curing (SR Ivocap Hi Impact and Lucitone 199) and four auto-curing (IvoBase Hybrid, IvoBase Hi Impact, PalaXpress, and Futura Gen) acrylic resins were used with their specific injection-molding technique to fabricate 6 specimens of each material. Linear and volumetric dimensional changes were determined by means of a digital caliper and an electronic hydrostatic balance, respectively, after water storage of 1, 30, or 90 days. Means and standard deviations of linear and volumetric dimensional changes were calculated in percentage (%). Statistical analysis was done using Student's and Welch's t tests with Bonferroni-Holm correction for multiple comparisons (α=0.05). Statistically significant differences in linear dimensional changes between resins were demonstrated at all three time intervals of water immersion (p≤0.05), with exception of the following comparisons which showed no significant difference: IvoBase Hi Impact/SR Ivocap Hi Impact and PalaXpress/Lucitone 199 after 1 day, Futura Gen/PalaXpress and PalaXpress/Lucitone 199 after 30 days, and IvoBase Hybrid/IvoBase Hi Impact after 90 days. Also, statistically significant differences in volumetric dimensional changes between resins were found at all three time intervals of water immersion (p≤0.05), with exception of the comparison between PalaXpress and Futura Gen. Denture base resins (IvoBase Hybrid and IvoBase Hi Impact) processed by the new injection-molding system (IvoBase), revealed superior dimensional precision. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Analysis of aggregated tick returns: Evidence for anomalous diffusion

NASA Astrophysics Data System (ADS)

Weber, Philipp

2007-01-01

In order to investigate the origin of large price fluctuations, we analyze stock price changes of ten frequently traded NASDAQ stocks in the year 2002. Though the influence of the trading frequency on the aggregate return in a certain time interval is important, it cannot alone explain the heavy-tailed distribution of stock price changes. For this reason, we analyze intervals with a fixed number of trades in order to eliminate the influence of the trading frequency and investigate the relevance of other factors for the aggregate return. We show that in tick time the price follows a discrete diffusion process with a variable step width while the difference between the number of steps in positive and negative direction in an interval is Gaussian distributed. The step width is given by the return due to a single trade and is long-term correlated in tick time. Hence, its mean value can well characterize an interval of many trades and turns out to be an important determinant for large aggregate returns. We also present a statistical model reproducing the cumulative distribution of aggregate returns. For an accurate agreement with the empirical distribution, we also take into account asymmetries of the step widths in different directions together with cross correlations between these asymmetries and the mean step width as well as the signs of the steps.

Bioactivity of gelatin coated magnetic iron oxide nanoparticles: in vitro evaluation.

PubMed

Gaihre, Babita; Khil, Myung Seob; Kang, Hyo Kyoung; Kim, Hak Yong

2009-02-01

Current research explores formation of bone like apatite on gelatin coated magnetic iron oxide nanoparticles (GIOPs) to evaluate the bioactivity of the material. The GIOPs were soaked in simulated body fluid (SBF) and the apatite formation on the surface was investigated in regular interval of time. Fourier transform-infrared (FT-IR) and x-ray diffraction spectroscopic (XRD) analyses were done to investigate the chemical changes and field emission-scanning electron microscopic (FE-SEM) analysis was done to investigate the morphological changes occurring on the surface of the GIOPs after soaking in different time intervals. The kinetic studies of the apatite growth in SBF suggest that initially calcium and phosphorous ions were deposited to the surface of the GIOPs from the SBF leading to formation of amorphous Ca/P particles. Later, after 9 days of the incubation the amorphous particles were fused to form needle and blade like crystalline structures of bone like apatite.

Accounting for dropout bias using mixed-effects models.

PubMed

Mallinckrodt, C H; Clark, W S; David, S R

2001-01-01

Treatment effects are often evaluated by comparing change over time in outcome measures. However, valid analyses of longitudinal data can be problematic when subjects discontinue (dropout) prior to completing the study. This study assessed the merits of likelihood-based repeated measures analyses (MMRM) compared with fixed-effects analysis of variance where missing values were imputed using the last observation carried forward approach (LOCF) in accounting for dropout bias. Comparisons were made in simulated data and in data from a randomized clinical trial. Subject dropout was introduced in the simulated data to generate ignorable and nonignorable missingness. Estimates of treatment group differences in mean change from baseline to endpoint from MMRM were, on average, markedly closer to the true value than estimates from LOCF in every scenario simulated. Standard errors and confidence intervals from MMRM accurately reflected the uncertainty of the estimates, whereas standard errors and confidence intervals from LOCF underestimated uncertainty.

Assessment of Reliable Change Using 95% Credible Intervals for the Differences in Proportions: A Statistical Analysis for Case-Study Methodology.

PubMed

Unicomb, Rachael; Colyvas, Kim; Harrison, Elisabeth; Hewat, Sally

2015-06-01

Case-study methodology studying change is often used in the field of speech-language pathology, but it can be criticized for not being statistically robust. Yet with the heterogeneous nature of many communication disorders, case studies allow clinicians and researchers to closely observe and report on change. Such information is valuable and can further inform large-scale experimental designs. In this research note, a statistical analysis for case-study data is outlined that employs a modification to the Reliable Change Index (Jacobson & Truax, 1991). The relationship between reliable change and clinical significance is discussed. Example data are used to guide the reader through the use and application of this analysis. A method of analysis is detailed that is suitable for assessing change in measures with binary categorical outcomes. The analysis is illustrated using data from one individual, measured before and after treatment for stuttering. The application of this approach to assess change in categorical, binary data has potential application in speech-language pathology. It enables clinicians and researchers to analyze results from case studies for their statistical and clinical significance. This new method addresses a gap in the research design literature, that is, the lack of analysis methods for noncontinuous data (such as counts, rates, proportions of events) that may be used in case-study designs.

A MIS 15-MIS 12 record of environmental changes and Lower Palaeolithic occupation from Valle Giumentina, central Italy

NASA Astrophysics Data System (ADS)

Villa, Valentina; Pereira, Alison; Chaussé, Christine; Nomade, Sébastien; Giaccio, Biagio; Limondin-Lozouet, Nicole; Fusco, Fabio; Regattieri, Eleonora; Degeai, Jean-Philippe; Robert, Vincent; Kuzucuoglu, Catherine; Boschian, Giovanni; Agostini, Silvano; Aureli, Daniele; Pagli, Marina; Bahain, Jean Jacques; Nicoud, Elisa

2016-11-01

An integrated geological study, including sedimentology, stable isotope analysis (δ18O, δ13C), geochemistry, micromorphology, biomarker analysis, 40Ar/39Ar geochronology and tephrochronology, was undertaken on the Quaternary infill of the Valle Giumentina basin in Central Italy, which also includes an outstanding archaeological succession, composed of nine human occupation levels ascribed to the Lower and Middle Palaeolithic. 40Ar/39Ar dating, and other palaeoenvironmental and tephrochronological data, constrain the sedimentary history of the whole succession to the MIS 15-MIS 12 interval, between 618 ± 13 ka and 456 ± 2 ka. Palaeoenvironmental proxies suggest that over this time interval of about 150 ka, sedimentary and pedogenic processes were mainly influenced by climatic changes, in particular by the pulsing of local mountain glaciers of the Majella massif. Specifically, the Valle Giumentina succession records glacio-fluvial and lacustrine sedimentation during the colder glacial periods and pedogenesis and/or alluvial sedimentation during the warmer interglacial and/or interstadial periods. During this interval, tectonics played a negligible role as a driving factor of local morphogenesis and sedimentation, whereas the general regional uplift experienced in the Middle Pleistocene led to capture of the basin and its definitive extinction after MIS 12. These data substantially improve previous knowledge of the chronology and sedimentary evolution of the succession, providing for the first time, a well constrained chronological and palaeoenvironmental framework for the archaeological and human palaeoecological record of Valle Giumentina.

Breast screening: What can the interval cancer review teach us? Are we perhaps being a bit too hard on ourselves?

PubMed

Lekanidi, Katerina; Dilks, Phil; Suaris, Tamara; Kennett, Steffan; Purushothaman, Hema

2017-09-01

The aim of this study was to determine the features that make interval cancers apparent on the preceding screening mammogram and determine whether changes in the ways of performing the interval cancer review will affect the true interval cancer rate. This study was approved by the clinical governance committee. Mammograms of women diagnosed with an interval cancer were included in the study if they had been allocated to either the "suspicious signs" group or "subtle signs" group, during the historic interval cancer review. Three radiologists, individually and blinded to the site of interval cancer, reviewed the mammograms and documented the presence, site, characteristics and classification of any abnormality. Findings were compared with the appearances of the abnormality at the site of subsequent cancer development by a different breast radiologist. The chi-squared test was used in the analysis of the results, seeking associations between recall concordance and cancer mammographic or histological characteristics. 111/590 interval cancers fulfilled the study inclusion criteria. In 17% of the cases none of the readers identified the relevant abnormality on the screening mammogram. 1/3 readers identified the relevant lesion in 22% of the cases, 2/3 readers in 28% of cases and all 3 readers in 33% of cases. The commonest unanimously recalled abnormality was microcalcification and the most challenging mammographic abnormality to detect was asymmetric density. We did not find any statistically significant association between recall concordance and time to interval cancer, position of lesion in the breast, breast density or cancer grade. Even the simple step of performing an independent blinded review of interval cancers reduces the rate of interval cancers classified as missed by up to 39%. Copyright © 2017 Elsevier B.V. All rights reserved.

Tropical Andean ecosystems and the need to keep warming limits below a +1.5°C threshold

NASA Astrophysics Data System (ADS)

Ruiz-Carrascal, D.; Herzog, S. K.; Guitierrez Lagoueyte, M. E.; Gonzalez-Duque, D.; Cuevas-Moreno, J.; del Valle, J. I.; Andreu-Hayles, L.; Herrera, D. A.; Martínez, R.

2017-12-01

Long-term climate change and rapid land-use change are synergistically threatening the integrity and functioning of tropical Andean ecosystems. The main goal of our research was to integrate climate change projections, biodiversity data and anthropogenically driven ecosystem disruption assessments to quantify the vulnerability of Andean ecosystems and species to global change at a local scale. We merged discernible trends in local quality-controlled weather station data with reanalysis data, as well as with historical and prospective simulation outputs of five well-known GCMs to assess a long-term context for the analysis of climate change exposure (temperature severity intervals). Individual, medium-term, multi-member GCM simulations included: altitude-corrected 2046-2065 (IPCC-AR4) climate change scenarios for the A1B emission scenario; and spatially-downscaled 2040-2069 (IPCC-AR5) projections for the RCP4.5. Previous studies reported mean annual temperature anomaly intervals that resulted in exceedingly high thresholds: the lowest severity interval (< +2.06°C) and the highest (> +2.71°C). The least severe interval extended up to the threshold widely recognized as `dangerous' climate change, thereby leading to an underestimation of the true vulnerability of Andean species. Our analyses suggest that temperature anomalies for the full extent of the tropical Andes will likely range from low (< +1.60°C) to high (> +2.61°C), exceeding the threshold of 'natural' climate variability (+1.78°C). Our results suggest that most species that were used as proxies of ecosystem vulnerabilities will likely experience overall low-to-medium-to-high temperature increases. Since many of them have potentially high sensitivity to such long-term changes, Andean species will likely experience greatly increases in vulnerability. The already-disrupted Andean ecosystems will suffer a further climatic stress, which will worsen the well-known detrimental synergies between climate and land-use changes. There is an imperative need to prioritize high-risk areas for the implementation of conservation and adaptation actions. Equally important, there is an urgent need to keep warming limits well below 2.0°C, ideally below +1.5°C, if we expect to preserve the integrity of our unique Andean environments.

Accessibility to surgical robot technology and prostate-cancer patient behavior for prostatectomy.

PubMed

Sugihara, Toru; Yasunaga, Hideo; Matsui, Hiroki; Nagao, Go; Ishikawa, Akira; Fujimura, Tetsuya; Fukuhara, Hiroshi; Fushimi, Kiyohide; Ohori, Makoto; Homma, Yukio

2017-07-01

To examine how surgical robot emergence affects prostate-cancer patient behavior in seeking radical prostatectomy focusing on geographical accessibility. In Japan, robotic surgery was approved in April 2012. Based on data in the Japanese Diagnosis Procedure Combination database between April 2012 and March 2014, distance to nearest surgical robot and interval days to radical prostatectomy (divided by mean interval in 2011: % interval days to radical prostatectomy) were calculated for individual radical prostatectomy cases at non-robotic hospitals. Caseload changes regarding distance to nearest surgical robot and robot introduction were investigated. Change in % interval days to radical prostatectomy was evaluated by multivariate analysis including distance to nearest surgical robot, age, comorbidity, hospital volume, operation type, hospital academic status, bed volume and temporal progress. % Interval days to radical prostatectomy became wider for distance to nearest surgical robot <30 km. When a surgical robot emerged within 30 and 10 km, the prostatectomy caseload in non-robot hospitals reduced by 13 and 18% within 6 months, respectively, while the robot hospitals gained +101% caseload (P < 0.01 for all) Multivariate analyses including 9759 open and 5052 non-robotic minimally invasive radical prostatectomies in 483 non-robot hospitals revealed a significant inverse association between distance to nearest surgical robot and % interval days to radical prostatectomy (B = -17.3% for distance to nearest surgical robot ≥30 km and -11.7% for 10-30 km versus distance to nearest surgical robot <10 km), while younger age, high-volume hospital, open-prostatectomy provider and temporal progress were other significant factors related to % interval days to radical prostatectomy widening (P < 0.05 for all). Robotic surgery accessibility within 30 km would make patients less likely select conventional surgery. The nearer a robot was, the faster the caseload reduction was. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Potassium channel KCNH2 K897T polymorphism and cardiac repolarization during exercise test: The Finnish Cardiovascular Study.

PubMed

Koskela, J; Laiho, J; KäHönen, M; Rontu, R; Lehtinen, R; Viik, J; Niemi, M; Niemelä, K; Kööbi, T; Turjanmaa, V; Pörsti, I; Lehtimäki, T; Nieminen, T

2008-01-01

Cardiac repolarization is regulated, in part, by the KCNH2 gene, which encodes a rapidly activating component of the delayed rectifier potassium channel. The gene expresses a functional single nucleotide polymorphism, K897T, which changes the biophysical properties of the channel. The objective of this study was to evaluate whether this polymorphism influences two indices of repolarization--the QT interval and T-wave alternans (TWA)--during different phases of a physical exercise test. The cohort consisted of 1,975 patients undergoing an exercise test during which on-line electrocardiographic data were registered. Information on coronary risk factors and medication was recorded. The 2690A>C nucleotide variation in the KCNH2 gene corresponding to the K897T amino acid change was analysed after polymerase chain reaction with allele-specific TaqMan probes. Among all subjects, the QTc intervals did not differ between the three genotype groups (p> or =0.31, RANOVA). Women with the CC genotype tended to have longer QT intervals during the exercise test, but the difference was statistically significant only at rest (p = 0.011, ANOVA). This difference was also detected when the analysis was adjusted for several factors influencing the QT interval. No statistically significant effects of the K897T polymorphism on TWA were observed among all subjects (p = 0.16, RANOVA), nor in men and women separately. The K897T polymorphism of the KCNH2 gene may not be a major genetic determinant for the TWA, but the influence of the CC genotype on QT interval deserves further research among women.

Effect of antihypertensive drug therapy on short-term heart rate variability in newly diagnosed essential hypertension.

PubMed

Pavithran, Purushothaman; Prakash, E Sankaranarayanan; Dutta, Tarun K; Madanmohan, Trakroo

2010-02-01

1. Abnormalities of cardiac autonomic regulation are a potential mechanism for morbidity despite blood pressure (BP) lowering in hypertension. Analysis of short-term (5 min) heart rate variability (HRV) provides a non-invasive probe of autonomic regulation of sino-atrial (SA) node automaticity. 2. We hypothesized that antihypertensive drug therapy would be associated with an increase in 5 min overall HRV, along with a decrease in blood pressure (BP), at 8 weeks follow up in subjects with newly diagnosed, never-treated essential hypertension. 3. One hundred and fifty patients (84 men and 66 women; mean (+/-SD) age 48 +/- 10 years) with newly diagnosed essential hypertension were divided to five groups of 30 patients each to receive one of the following antihypertensive drugs (or drug combinations): 5 mg/day amlodipine; 50 mg/day atenolol; 5 mg/day enalapril; 25 mg/day hydrochlorothiazide; or a combination of 5 mg/day amlodipine and 50 mg/day atenolol. 4. The only significant change in HRV indices was an increase in total variability of RR intervals and an increase in high-frequency (HF) RR interval spectral power in the amlodipine + atenolol-treated group (P < 0.05). 5. The results indicate that there is a dissociation between changes in short-term HRV and mean RR interval and BP lowering in patients with newly diagnosed hypertension. 6. We interpret the increase in HF RR interval spectral power in the amlodipine + atenolol-treated group as being due to an increase in vagal modulation of RR intervals and/or diminution in sympathetic restraint of respiratory sinus arrhythmia.

Power frequency spectrum analysis of surface EMG signals of upper limb muscles during elbow flexion - A comparison between healthy subjects and stroke survivors.

PubMed

Angelova, Silvija; Ribagin, Simeon; Raikova, Rositsa; Veneva, Ivanka

2018-02-01

After a stroke, motor units stop working properly and large, fast-twitch units are more frequently affected. Their impaired functions can be investigated during dynamic tasks using electromyographic (EMG) signal analysis. The aim of this paper is to investigate changes in the parameters of the power/frequency function during elbow flexion between affected, non-affected, and healthy muscles. Fifteen healthy subjects and ten stroke survivors participated in the experiments. Electromyographic data from 6 muscles of the upper limbs during elbow flexion were filtered and normalized to the amplitudes of EMG signals during maximal isometric tasks. The moments when motion started and when the flexion angle reached its maximal value were found. Equal intervals of 0.3407 s were defined between these two moments and one additional interval before the start of the flexion (first one) was supplemented. For each of these intervals the power/frequency function of EMG signals was calculated. The mean (MNF) and median frequencies (MDF), the maximal power (MPw) and the area under the power function (APw) were calculated. MNF was always higher than MDF. A significant decrease in these frequencies was found in only three post-stroke survivors. The frequencies in the first time interval were nearly always the highest among all intervals. The maximal power was nearly zero during first time interval and increased during the next ones. The largest values of MPw and APw were found for the flexor muscles and they increased for the muscles of the affected arm compared to the non-affected one of stroke survivors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Screening for phaeochromocytoma and paraganglioma: impact of using supine reference intervals for plasma metanephrines with samples collected from fasted/seated patients.

PubMed

Casey, R; Griffin, T P; Wall, D; Dennedy, M C; Bell, M; O'Shea, P M

2017-01-01

Background The Endocrine Society Clinical Practice Guideline on Phaeochomocytoma and Paraganglioma recommends phlebotomy for plasma-free metanephrines with patients fasted and supine using appropriately defined reference intervals. Studies have shown higher diagnostic sensitivities using these criteria. Further, with seated-sampling protocols, for result interpretation, reference intervals that do not compromise diagnostic sensitivity should be employed. Objective To determine the impact on diagnostic performance and financial cost of using supine reference intervals for result interpretation with our current plasma-free metanephrines fasted/seated-sampling protocol. Methods We conducted a retrospective cohort study of patients who underwent screening for PPGL using plasma-free metanephrines from 2009 to 2014 at Galway University Hospitals. Plasma-free metanephrines were measured using liquid chromatography-tandem mass spectrometry. Supine thresholds for plasma normetanephrine and metanephrine set at 610 pmol/L and 310 pmol/L, respectively, were used. Results A total of 183 patients were evaluated. Mean age of participants was 53.4 (±16.3) years. Five of 183 (2.7%) patients had histologically confirmed PPGL (males, n=4). Using seated reference intervals for plasma-free metanephrines, diagnostic sensitivity and specificity were 100% and 98.9%, respectively, with two false-positive cases. Application of reference intervals established in subjects supine and fasted to this cohort gave diagnostic sensitivity of 100% with specificity of 74.7%. Financial analysis of each pretesting strategy demonstrated cost-equivalence (€147.27/patient). Conclusion Our cost analysis, together with the evidence that fasted/supine-sampling for plasma-free metanephrines, offers more reliable exclusion of PPGL mandates changing our current practice. This study highlights the important advantages of standardized diagnostic protocols for plasma-free metanephrines to ensure the highest diagnostic accuracy for investigation of PPGL.

Rasch analysis of the Edmonton Symptom Assessment System and research implications.

PubMed

Cheifetz, O; Packham, T L; Macdermid, J C

2014-04-01

Reliable and valid assessment of the disease burden across all forms of cancer is critical to the evaluation of treatment effectiveness and patient progress. The Edmonton Symptom Assessment System (esas) is used for routine evaluation of people attending for cancer care. In the present study, we used Rasch analysis to explore the measurement properties of the esas and to determine the effect of using Rasch-proposed interval-level esas scoring compared with traditional scoring when evaluating the effects of an exercise program for cancer survivors. Polytomous Rasch analysis (Andrich's rating-scale model) was applied to data from 26,645 esas questionnaires completed at the Juravinski Cancer Centre. The fit of the esas to the polytomous Rasch model was investigated, including evaluations of differential item functioning for sex, age, and disease group. The research implication was investigated by comparing the results of an observational research study previously analysed using a traditional approach with the results obtained by Rasch-proposed interval-level esas scoring. The Rasch reliability index was 0.73, falling short of the desired 0.80-0.90 level. However, the esas was found to fit the Rasch model, including the criteria for uni-dimensional data. The analysis suggests that the current esas scoring system of 0-10 could be collapsed to a 6-point scale. Use of the Rasch-proposed interval-level scoring yielded results that were different from those calculated using summarized ordinal-level esas scores. Differential item functioning was not found for sex, age, or diagnosis groups. The esas is a moderately reliable uni-dimensional measure of cancer disease burden and can provide interval-level scaling with Rasch-based scoring. Further, our study indicates that, compared with the traditional scoring metric, Rasch-based scoring could result in substantive changes to conclusions.

Prolonged dry periods between rainfall events shorten the growth period of the resurrection plant Reaumuria soongorica.

PubMed

Zhang, Zhengzhong; Shan, Lishan; Li, Yi

2018-01-01

The resurrection plant Reaumuria soongorica is widespread across Asia, southern Europe, and North Africa and is considered to be a constructive keystone species in desert ecosystems, but the impacts of climate change on this species in desert ecosystems are unclear. Here, the morphological responses of R. soongorica to changes in rainfall quantity (30% reduction and 30% increase in rainfall quantity) and interval (50% longer drought interval between rainfall events) were tested. Stage-specific changes in growth were monitored by sampling at the beginning, middle, and end of the growing season. Reduced rainfall decreased the aboveground and total biomass, while additional precipitation generally advanced R. soongorica growth and biomass accumulation. An increased interval between rainfall events resulted in an increase in root biomass in the middle of the growing season, followed by a decrease toward the end. The response to the combination of increased rainfall quantity and interval was similar to the response to increased interval alone, suggesting that the effects of changes in rainfall patterns exert a greater influence than increased rainfall quantity. Thus, despite the short duration of this experiment, consequences of changes in rainfall regime on seedling growth were observed. In particular, a prolonged rainfall interval shortened the growth period, suggesting that climate change-induced rainfall variability may have significant effects on the structure and functioning of desert ecosystems.

Potential use of hydrocarbons for aging Lucilia sericata blowfly larvae to establish the postmortem interval.

PubMed

Moore, Hannah E; Adam, Craig D; Drijfhout, Falko P

2013-03-01

Previous studies on Diptera have shown the potential for the use of cuticular hydrocarbons' analysis in the determination of larval age and hence the postmortem interval (PMI) for an associated cadaver. In this work, hydrocarbon compounds, extracted daily until pupation from the cuticle of the blowfly Lucilia sericata (Diptera: Calliphoridae), have been analyzed using gas chromatography-mass spectrometry (GC-MS). The results show distinguishing features within the hydrocarbon profile over the period of the larvae life cycle, with significant chemical changes occurring from the younger larvae to the postfeeding larvae. Further interpretation of the chromatograms using principal component analysis revealed a strong correlation between the magnitudes of particular principal components and time. This outcome suggests that, under the conditions of this study, the cuticular hydrocarbons evolve in a systematic fashion with time, thus supporting the potential for GC-MS analysis as a tool for establishing PMI where such a species is present. © 2012 American Academy of Forensic Sciences.

Steerable dyadic wavelet transform and interval wavelets for enhancement of digital mammography

NASA Astrophysics Data System (ADS)

Laine, Andrew F.; Koren, Iztok; Yang, Wuhai; Taylor, Fred J.

1995-04-01

This paper describes two approaches for accomplishing interactive feature analysis by overcomplete multiresolution representations. We show quantitatively that transform coefficients, modified by an adaptive non-linear operator, can make more obvious unseen or barely seen features of mammography without requiring additional radiation. Our results are compared with traditional image enhancement techniques by measuring the local contrast of known mammographic features. We design a filter bank representing a steerable dyadic wavelet transform that can be used for multiresolution analysis along arbitrary orientations. Digital mammograms are enhanced by orientation analysis performed by a steerable dyadic wavelet transform. Arbitrary regions of interest (ROI) are enhanced by Deslauriers-Dubuc interpolation representations on an interval. We demonstrate that our methods can provide radiologists with an interactive capability to support localized processing of selected (suspicion) areas (lesions). Features extracted from multiscale representations can provide an adaptive mechanism for accomplishing local contrast enhancement. By improving the visualization of breast pathology can improve changes of early detection while requiring less time to evaluate mammograms for most patients.

Changes in Vertebral Column Height (VCH) at Different Distance Intervals During a 3-Mile Walk.

PubMed

Roush, J R; Kee, M; Toeppe, J

2008-08-01

The purpose of this study was to determine the changes in vertebral column height (VCH) of males and females, at every one-half mile, for a total walking distance of 3 miles. Twenty males and twenty females between the ages of 21 and 40 years walked 3 miles on a treadmill maintaining a walking speed that the subject rated between 12 and 14 on Borg's rate of perceived exertion scale. Blood pressure, heart rate, and VCH measurements were taken initially and at each half-mile interval throughout the three-mile walk. Vertebral column height (VCH) was measured from the spinous process of C7 to S2 using a standard tape measure. Significant differences existed in vertebral column height according to sex (F = 16.18; p < .05) and significant differences in vertebral column height at the different distances (F = 65.02: p < .0001). Significant changes occurred in the VCH between half-mile intervals only between 0.5 miles and 1.0 mile and between 1.0 mile and 1.5 miles during the walk. As found with a regression analysis, curvilinear relationship exists between the distance walked and VCH; with VCH decreasing throughout the distance of the walk. Vertebral column height decreased in a curvilinear relationship throughout the distance of walking 3 miles in both males and females.

Changes in Vertebral Column Height (VCH) at Different Distance Intervals During a 3-Mile Walk

PubMed Central

Kee, M; Toeppe, J

2008-01-01

Background The purpose of this study was to determine the changes in vertebral column height (VCH) of males and females, at every one-half mile, for a total walking distance of 3 miles. Methods Twenty males and twenty females between the ages of 21 and 40 years walked 3 miles on a treadmill maintaining a walking speed that the subject rated between 12 and 14 on Borg's rate of perceived exertion scale. Blood pressure, heart rate, and VCH measurements were taken initially and at each half-mile interval throughout the three-mile walk. Vertebral column height (VCH) was measured from the spinous process of C7 to S2 using a standard tape measure. Results Significant differences existed in vertebral column height according to sex (F = 16.18; p < .05) and significant differences in vertebral column height at the different distances (F = 65.02: p < .0001). Significant changes occurred in the VCH between half-mile intervals only between 0.5 miles and 1.0 mile and between 1.0 mile and 1.5 miles during the walk. As found with a regression analysis, curvilinear relationship exists between the distance walked and VCH; with VCH decreasing throughout the distance of the walk. Conclusions Vertebral column height decreased in a curvilinear relationship throughout the distance of walking 3 miles in both males and females. PMID:21509126

A Rasch-validated version of the upper extremity functional index for interval-level measurement of upper extremity function.

PubMed

Hamilton, Clayon B; Chesworth, Bert M

2013-11-01

The original 20-item Upper Extremity Functional Index (UEFI) has not undergone Rasch validation. The purpose of this study was to determine whether Rasch analysis supports the UEFI as a measure of a single construct (ie, upper extremity function) and whether a Rasch-validated UEFI has adequate reproducibility for individual-level patient evaluation. This was a secondary analysis of data from a repeated-measures study designed to evaluate the measurement properties of the UEFI over a 3-week period. Patients (n=239) with musculoskeletal upper extremity disorders were recruited from 17 physical therapy clinics across 4 Canadian provinces. Rasch analysis of the UEFI measurement properties was performed. If the UEFI did not fit the Rasch model, misfitting patients were deleted, items with poor response structure were corrected, and misfitting items and redundant items were deleted. The impact of differential item functioning on the ability estimate of patients was investigated. A 15-item modified UEFI was derived to achieve fit to the Rasch model where the total score was supported as a measure of upper extremity function only. The resultant UEFI-15 interval-level scale (0-100, worst to best state) demonstrated excellent internal consistency (person separation index=0.94) and test-retest reliability (intraclass correlation coefficient [2,1]=.95). The minimal detectable change at the 90% confidence interval was 8.1. Patients who were ambidextrous or bilaterally affected were excluded to allow for the analysis of differential item functioning due to limb involvement and arm dominance. Rasch analysis did not support the validity of the 20-item UEFI. However, the UEFI-15 was a valid and reliable interval-level measure of a single dimension: upper extremity function. Rasch analysis supports using the UEFI-15 in physical therapist practice to quantify upper extremity function in patients with musculoskeletal disorders of the upper extremity.

A Rasch-Validated Version of the Upper Extremity Functional Index for Interval-Level Measurement of Upper Extremity Function

PubMed Central

Chesworth, Bert M.

2013-01-01

Background The original 20-item Upper Extremity Functional Index (UEFI) has not undergone Rasch validation. Objective The purpose of this study was to determine whether Rasch analysis supports the UEFI as a measure of a single construct (ie, upper extremity function) and whether a Rasch-validated UEFI has adequate reproducibility for individual-level patient evaluation. Design This was a secondary analysis of data from a repeated-measures study designed to evaluate the measurement properties of the UEFI over a 3-week period. Methods Patients (n=239) with musculoskeletal upper extremity disorders were recruited from 17 physical therapy clinics across 4 Canadian provinces. Rasch analysis of the UEFI measurement properties was performed. If the UEFI did not fit the Rasch model, misfitting patients were deleted, items with poor response structure were corrected, and misfitting items and redundant items were deleted. The impact of differential item functioning on the ability estimate of patients was investigated. Results A 15-item modified UEFI was derived to achieve fit to the Rasch model where the total score was supported as a measure of upper extremity function only. The resultant UEFI-15 interval-level scale (0–100, worst to best state) demonstrated excellent internal consistency (person separation index=0.94) and test-retest reliability (intraclass correlation coefficient [2,1]=.95). The minimal detectable change at the 90% confidence interval was 8.1. Limitations Patients who were ambidextrous or bilaterally affected were excluded to allow for the analysis of differential item functioning due to limb involvement and arm dominance. Conclusion Rasch analysis did not support the validity of the 20-item UEFI. However, the UEFI-15 was a valid and reliable interval-level measure of a single dimension: upper extremity function. Rasch analysis supports using the UEFI-15 in physical therapist practice to quantify upper extremity function in patients with musculoskeletal disorders of the upper extremity. PMID:23813086

Theoretical evaluation of accuracy in position and size of brain activity obtained by near-infrared topography

NASA Astrophysics Data System (ADS)

Kawaguchi, Hiroshi; Hayashi, Toshiyuki; Kato, Toshinori; Okada, Eiji

2004-06-01

Near-infrared (NIR) topography can obtain a topographical distribution of the activated region in the brain cortex. Near-infrared light is strongly scattered in the head, and the volume of tissue sampled by a source-detector pair on the head surface is broadly distributed in the brain. This scattering effect results in poor resolution and contrast in the topographic image of the brain activity. In this study, a one-dimensional distribution of absorption change in a head model is calculated by mapping and reconstruction methods to evaluate the effect of the image reconstruction algorithm and the interval of measurement points for topographic imaging on the accuracy of the topographic image. The light propagation in the head model is predicted by Monte Carlo simulation to obtain the spatial sensitivity profile for a source-detector pair. The measurement points are one-dimensionally arranged on the surface of the model, and the distance between adjacent measurement points is varied from 4 mm to 28 mm. Small intervals of the measurement points improve the topographic image calculated by both the mapping and reconstruction methods. In the conventional mapping method, the limit of the spatial resolution depends upon the interval of the measurement points and spatial sensitivity profile for source-detector pairs. The reconstruction method has advantages over the mapping method which improve the results of one-dimensional analysis when the interval of measurement points is less than 12 mm. The effect of overlapping of spatial sensitivity profiles indicates that the reconstruction method may be effective to improve the spatial resolution of a two-dimensional reconstruction of topographic image obtained with larger interval of measurement points. Near-infrared topography with the reconstruction method potentially obtains an accurate distribution of absorption change in the brain even if the size of absorption change is less than 10 mm.

77 FR 6160 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Order Granting Approval of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-07

... SLV and USO strike price intervals. \\4\\ The Exchange also proposed certain non-substantive changes to... Strike Price Intervals for SLV and USO Options February 1, 2012. I. Introduction On December 7, 2011...-4 thereunder,\\2\\ a proposed rule change regarding strike price intervals for options on iShares[reg...

Recent landscape change in California's Central Valley

NASA Astrophysics Data System (ADS)

Soulard, C. E.; Wilson, T. S.

2012-12-01

Long term monitoring of land use and land cover in California's intensively farmed Central Valley reveals several key physical and socioeconomic factors driving landscape change. As part of the USGS Land Cover Trends Project, we analyzed modern land-use/land-cover change for the California Central Valley ecoregion between 2000 and 2010, monitoring annual change between 2005 and 2010, while creating two new change intervals (2000-2005 and 2005-2010) to update the existing 27-year, interval-based analysis. Between 2000 and 2010, agricultural lands fluctuated due to changes in water allocations and emerging drought conditions, or were lost permanently to development (240 square km). Land-use pressure from agriculture and development also led to a decline in grasslands and shrublands across the region (280 square km). Overall, 400 square km of new developed lands were added in the first decade of the 21st century. From 2007 to 2010, development only expanded by 50 square km, coinciding with defaults in the banking system, the onset of historic foreclosure crisis in California and the global economic downturn. Our annual LULC change estimates capture landscape-level change in response to regional policy changes, climate, and fluctuations (e.g., growth or decline) in the national and global economy. The resulting change data provide insights into the drivers of landscape change in the California Central Valley and the combination of two consistent mapping efforts represents the first continuous, 37-year endeavor of its kind.

Combined process automation for large-scale EEG analysis.

PubMed

Sfondouris, John L; Quebedeaux, Tabitha M; Holdgraf, Chris; Musto, Alberto E

2012-01-01

Epileptogenesis is a dynamic process producing increased seizure susceptibility. Electroencephalography (EEG) data provides information critical in understanding the evolution of epileptiform changes throughout epileptic foci. We designed an algorithm to facilitate efficient large-scale EEG analysis via linked automation of multiple data processing steps. Using EEG recordings obtained from electrical stimulation studies, the following steps of EEG analysis were automated: (1) alignment and isolation of pre- and post-stimulation intervals, (2) generation of user-defined band frequency waveforms, (3) spike-sorting, (4) quantification of spike and burst data and (5) power spectral density analysis. This algorithm allows for quicker, more efficient EEG analysis. Copyright © 2011 Elsevier Ltd. All rights reserved.

A hierarchical model for regional analysis of population change using Christmas Bird Count data, with application to the American Black Duck

USGS Publications Warehouse

Link, W.A.; Sauer, J.R.; Niven, D.K.

2006-01-01

Analysis of Christmas Bird Count (CBC) data is complicated by the need to account for variation in effort on counts and to provide summaries over large geographic regions. We describe a hierarchical model for analysis of population change using CBC data that addresses these needs. The effect of effort is modeled parametrically, with parameter values varying among strata as identically distributed random effects. Year and site effects are modeled hierarchically, accommodating large regional variation in number of samples and precision of estimates. The resulting model is complex, but a Bayesian analysis can be conducted using Markov chain Monte Carlo techniques. We analyze CBC data for American Black Ducks (Anas rubripes), a species of considerable management interest that has historically been monitored using winter surveys. Over the interval 1966-2003, Black Duck populations showed distinct regional patterns of population change. The patterns shown by CBC data are similar to those shown by the Midwinter Waterfowl Inventory for the United States.

Prognostic impact of peakVO2-changes in stable CHF on chronic beta-blocker treatment.

PubMed

Frankenstein, L; Nelles, M; Hallerbach, M; Dukic, D; Fluegel, A; Schellberg, D; Katus, H A; Remppis, A; Zugck, C

2007-11-15

Peak oxygen uptake (pVO2) is used for risk stratification in chronic heart failure (CHF), but little is known about the prognostic impact of pVO2-changes in patients on chronic beta-blocker (BBL) therapy. We therefore prospectively evaluated individual pVO2-changes at a 6-month interval in patients all receiving BBL. 194 patients with stable CHF on stable medication were included (V1) and underwent clinical evaluation and exercise testing. Testing was repeated (V2) at 5.7+/-1.5 months after V1 and patients were followed >12 months after V2. Death or hospitalisation due to cardiac reasons was the predefined EP (EPP, end-point positive; n=62; EPN, end-point negative; n=113). Initial characteristics did not differ between EPP and EPN. Multivariate cox regression analysis revealed that change of pVO2 (EPP: -0.6+/-2.6 ml/kg min; EPN: +2.5+/-3.3 ml/kg min; p<0.001) was independent to pVO2, LVEF, NTproBNP and NYHA at V2 for prediction of the combined end-point during follow-up. An increase of pVO2 by 10% was identified as an adequate cut-off value for risk stratification and ROC-analysis showed the significant incremental prognostic value of the determination of pVO2 changes in combination with pVO2. Serial measurements of pVO2 yield additional information for risk stratification in clinically homogenous CHF patients receiving BBL. This is the first study demonstrating this fact within a narrow predefined interval with all patients on BBL.

High-Intensity Interval Cycling Exercise on Wave Reflection and Pulse Wave Velocity.

PubMed

Kingsley, J Derek; Tai, Yu Lun; Vaughan, Jeremiah A; Mayo, Xián

2017-05-01

Kingsley, JD, Tai, YL, Vaughan, J, and Mayo, X. High-intensity interval cycling exercise on wave reflection and pulse wave velocity. J Strength Cond Res 31(5): 1313-1320, 2017-The purpose of this study was to assess the effects of high-intensity exercise on wave reflection and aortic stiffness. Nine young, healthy men (mean ± SD: age: 22 ± 2 years) participated in the study. The high-intensity interval cycling exercise consisted of 3 sets of Wingate Anaerobic Tests (WATs) with 7.5% of bodyweight as resistance and 2 minutes of rest between each set. Measurements were taken at rest and 1 minute after completion of the WATs. Brachial and aortic blood pressures, as well as wave reflection characteristics, were measured through pulse wave analysis. Aortic stiffness was assessed through carotid-femoral pulse wave velocity (cfPWV). A repeated-measures analysis of variance was used to investigate the effects of the WATs on blood pressure and vascular function across time. There was no change in brachial or aortic systolic pressure from rest to recovery. There was a significant (p ≤ 0.05) decrease in brachial diastolic pressure (rest: 73 ± 6 mm Hg; recovery: 67 ± 9 mm Hg) and aortic diastolic pressure (rest: 75 ± 6 mm Hg; recovery: 70 ± 9 mm Hg) from rest to recovery. In addition, there was no significant change in the augmentation index (rest: 111.4 ± 6.5%; recovery: 109.8 ± 5.8%, p = 0.65) from rest to recovery. However, there was a significant (p ≤ 0.05) increase in the augmentation index normalized at 75 b·min (rest: 3.29 ± 9.82; recovery 21.21 ± 10.87) during recovery compared with rest. There was no change in cfPWV (rest: 5.3 ± 0.8 m·s; recovery: 5.7 ± 0.5m·s; p = 0.09) in response to the WAT. These data demonstrate that high-intensity interval cycling exercise with short rest periods has a nonsignificant effect on vascular function.

Evaluation of an Automatic Registration-Based Algorithm for Direct Measurement of Volume Change in Tumors

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

Sarkar, Saradwata; Johnson, Timothy D.; Ma, Bing

2012-07-01

Purpose: Assuming that early tumor volume change is a biomarker for response to therapy, accurate quantification of early volume changes could aid in adapting an individual patient's therapy and lead to shorter clinical trials. We investigated an image registration-based approach for tumor volume change quantification that may more reliably detect smaller changes that occur in shorter intervals than can be detected by existing algorithms. Methods and Materials: Variance and bias of the registration-based approach were evaluated using retrospective, in vivo, very-short-interval diffusion magnetic resonance imaging scans where true zero tumor volume change is unequivocally known and synthetic data, respectively. Themore » interval scans were nonlinearly registered using two similarity measures: mutual information (MI) and normalized cross-correlation (NCC). Results: The 95% confidence interval of the percentage volume change error was (-8.93% to 10.49%) for MI-based and (-7.69%, 8.83%) for NCC-based registrations. Linear mixed-effects models demonstrated that error in measuring volume change increased with increase in tumor volume and decreased with the increase in the tumor's normalized mutual information, even when NCC was the similarity measure being optimized during registration. The 95% confidence interval of the relative volume change error for the synthetic examinations with known changes over {+-}80% of reference tumor volume was (-3.02% to 3.86%). Statistically significant bias was not demonstrated. Conclusion: A low-noise, low-bias tumor volume change measurement algorithm using nonlinear registration is described. Errors in change measurement were a function of tumor volume and the normalized mutual information content of the tumor.« less

Randomized sham-controlled trial of renal sympathetic denervation in mild resistant hypertension.

PubMed

Desch, Steffen; Okon, Thomas; Heinemann, Diana; Kulle, Konrad; Röhnert, Karoline; Sonnabend, Melanie; Petzold, Martin; Müller, Ulrike; Schuler, Gerhard; Eitel, Ingo; Thiele, Holger; Lurz, Philipp

2015-06-01

Few data are available with regard to the effectiveness of renal sympathetic denervation in patients with resistant hypertension yet only mildly elevated blood pressure (BP). Patients with resistant hypertension and slightly elevated BP (day-time systolic pressure, 135-149 and diastolic pressure, 90-94 mm Hg on 24-hour ambulatory measurement) were randomized in a 1:1 ratio to renal sympathetic denervation with the Symplicity Flex Catheter (Medtronic) or an invasive sham procedure. The primary efficacy end point was the change in 24-hour systolic BP at 6 months between groups in the intention to treat population. A total of 71 patients underwent randomization. Baseline day-time systolic BP was 144.4±4.8 mm Hg in patients assigned to denervation and 143.0±4.7 mm Hg in patients randomized to the sham procedure. The mean change in 24-hour systolic BP in the intention to treat cohort at 6 months was -7.0 mm Hg (95% confidence interval, -10.8 to -3.2) for patients undergoing denervation and -3.5 mm Hg (95% confidence interval, -6.7 to -0.2) in the sham group (P=0.15). In the per protocol population, the change in 24-hour systolic BP at 6 months was -8.3 mm Hg (95% confidence interval, -11.7 to -5.0) for patients undergoing denervation and -3.5 mm Hg (95% confidence interval, -6.8 to -0.2) in the sham group (P=0.042). In patients with mild resistant hypertension, renal sympathetic denervation failed to show a significant reduction in the primary end point of 24-hour systolic BP at 6 months between groups in the intention to treat analysis. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01656096. © 2015 American Heart Association, Inc.

A pilot investigation of the effect of extremely low frequency pulsed electromagnetic fields on humans' heart rate variability.

PubMed

Baldi, Emilio; Baldi, Claudio; Lithgow, Brian J

2007-01-01

The question whether pulsed electromagnetic field (PEMF) can affect the heart rhythm is still controversial. This study investigates the effects on the cardiocirculatory system of ELF-PEMFs. It is a follow-up to an investigation made of the possible therapeutic effect ELF-PEMFs, using a commercially available magneto therapeutic unit, had on soft tissue injury repair in humans. Modulation of heart rate (HR) or heart rate variability (HRV) can be detected from changes in periodicity of the R-R interval and/or from changes in the numbers of heart-beat/min (bpm), however, R-R interval analysis gives only a quantitative insight into HRV. A qualitative understanding of HRV can be obtained considering the power spectral density (PSD) of the R-R intervals Fourier transform. In this study PSD is the investigative tool used, more specifically the low frequency (LF) PSD and high frequency (HF) PSD ratio (LF/HF) which is an indicator of sympatho-vagal balance. To obtain the PSD value, variations of the R-R time intervals were evaluated from a continuously recorded ECG. The results show a HR variation in all the subjects when they are exposed to the same ELF-PEMF. This variation can be detected by observing the change in the sympatho-vagal equilibrium, which is an indicator of modulation of heart activity. Variation of the LF/HF PSD ratio mainly occurs at transition times from exposure to nonexposure, or vice versa. Also of interest are the results obtained during the exposure of one subject to a range of different ELF-PEMFs. This pilot study suggests that a full investigation into the effect of ELF-PEMFs on the cardiovascular system is justified.

Differential Decomposition Among Pig, Rabbit, and Human Remains.

PubMed

Dautartas, Angela; Kenyhercz, Michael W; Vidoli, Giovanna M; Meadows Jantz, Lee; Mundorff, Amy; Steadman, Dawnie Wolfe

2018-03-30

While nonhuman animal remains are often utilized in forensic research to develop methods to estimate the postmortem interval, systematic studies that directly validate animals as proxies for human decomposition are lacking. The current project compared decomposition rates among pigs, rabbits, and humans at the University of Tennessee's Anthropology Research Facility across three seasonal trials that spanned nearly 2 years. The Total Body Score (TBS) method was applied to quantify decomposition changes and calculate the postmortem interval (PMI) in accumulated degree days (ADD). Decomposition trajectories were analyzed by comparing the estimated and actual ADD for each seasonal trial and by fuzzy cluster analysis. The cluster analysis demonstrated that the rabbits formed one group while pigs and humans, although more similar to each other than either to rabbits, still showed important differences in decomposition patterns. The decomposition trends show that neither nonhuman model captured the pattern, rate, and variability of human decomposition. © 2018 American Academy of Forensic Sciences.

Analysis of the operation of the SCD Response intermittent compression system.

PubMed

Morris, Rh J; Griffiths, H; Woodcock, J P

2002-01-01

The work assessed the performance of the Kendall SCD Response intermittent pneumatic compression system for deep vein thrombosis prophylaxis, which claimed to set its cycle according to the blood flow characteristics of individual patient limbs. A series of tests measured the system response in various situations, including application to the limbs of healthy volunteers, and to false limbs. Practical experimentation and theoretical analysis were used to investigate influences on the system functioning other than blood flow. The system tested did not seem to perform as claimed, being unable to distinguish between real and fake limbs. The intervals between compressions were set to times unrealistic for venous refill, with temperature changes in the cuff the greatest influence on performance. Combining the functions of compression and the measurement of the effects of compression in the same air bladder makes temperature artefacts unavoidable and can cause significant errors in the inter-compression interval.

Rasch Analysis of Scientific Literacy in an Astronomical Citizen Science Project

NASA Astrophysics Data System (ADS)

Price, A.

2012-06-01

(Abstract only) We investigate change in attitudes towards science and belief in the nature of science by participants in a citizen science project about astronomy. A pre-test was given to 1,385 participants and a post-test was given six months later to 165 participants. Nine participants were interviewed. Responses were analyzed using the Rasch Rating Scale Model to place Likert data on an interval scale allowing for more sensitive parametric analysis. Results show that overall attitudes did not change, p = .225. However, there was significant change towards attitudes relating to science news (positive) and scientific self efficacy (negative), p = .001 and p = .035, respectively. This change was related to social activity in the project. Beliefs in the nature of science exhibited a small but significant increase, p = .04. Relative positioning of scores on the belief items suggests the increase is mostly due to reinforcement of current beliefs.

Rasch Analysis of Scientific Literacy in an Astronomical Citizen Science Project

NASA Astrophysics Data System (ADS)

Price, Aaron

2011-05-01

We investigate change in attitudes towards science and belief in the nature of science by participants in a citizen science project about astronomy. A pre-test was given to 1,385 participants and a post-test was given six months later to 165 participants. Nine participants were interviewed. Responses were analyzed using the Rasch Rating Scale Model to place Likert data on an interval scale allowing for more sensitive parametric analysis. Results show that overall attitudes did not change, p = .225. However, there was significant change towards attitudes relating to science news (positive) and scientific self efficacy (negative), p < .001 and p = .035 respectively. This change was related to social activity in the project. Beliefs in the nature of science exhibited a small, but significant increase, p = .04. Relative positioning of scores on the belief items suggests the increase is mostly due to reinforcement of current beliefs.

Detection of QT prolongation using a novel electrocardiographic analysis algorithm applying intelligent automation: prospective blinded evaluation using the Cardiac Safety Research Consortium electrocardiographic database.

PubMed

Green, Cynthia L; Kligfield, Paul; George, Samuel; Gussak, Ihor; Vajdic, Branislav; Sager, Philip; Krucoff, Mitchell W

2012-03-01

The Cardiac Safety Research Consortium (CSRC) provides both "learning" and blinded "testing" digital electrocardiographic (ECG) data sets from thorough QT (TQT) studies annotated for submission to the US Food and Drug Administration (FDA) to developers of ECG analysis technologies. This article reports the first results from a blinded testing data set that examines developer reanalysis of original sponsor-reported core laboratory data. A total of 11,925 anonymized ECGs including both moxifloxacin and placebo arms of a parallel-group TQT in 181 subjects were blindly analyzed using a novel ECG analysis algorithm applying intelligent automation. Developer-measured ECG intervals were submitted to CSRC for unblinding, temporal reconstruction of the TQT exposures, and statistical comparison to core laboratory findings previously submitted to FDA by the pharmaceutical sponsor. Primary comparisons included baseline-adjusted interval measurements, baseline- and placebo-adjusted moxifloxacin QTcF changes (ddQTcF), and associated variability measures. Developer and sponsor-reported baseline-adjusted data were similar with average differences <1 ms for all intervals. Both developer- and sponsor-reported data demonstrated assay sensitivity with similar ddQTcF changes. Average within-subject SD for triplicate QTcF measurements was significantly lower for developer- than sponsor-reported data (5.4 and 7.2 ms, respectively; P < .001). The virtually automated ECG algorithm used for this analysis produced similar yet less variable TQT results compared with the sponsor-reported study, without the use of a manual core laboratory. These findings indicate that CSRC ECG data sets can be useful for evaluating novel methods and algorithms for determining drug-induced QT/QTc prolongation. Although the results should not constitute endorsement of specific algorithms by either CSRC or FDA, the value of a public domain digital ECG warehouse to provide prospective, blinded comparisons of ECG technologies applied for QT/QTc measurement is illustrated. Copyright © 2012 Mosby, Inc. All rights reserved.

Unravelling the Paleoenvironmental and Diagenetic History of Fluviolacustrine Sediments from a Northern Kenya Rift Basin Through Analysis of HSPDP West Turkana-Kaitio Core Material

NASA Astrophysics Data System (ADS)

Rabideaux, N. M.; Chaudhary, M. S.; Deocampo, D.; Feibel, C. S.; Cohen, A. S.

2016-12-01

The Hominin Sites and Paleolakes Drilling Project (HSPDP) collected sediment cores from six rift basins in Ethiopia and Kenya. The goal of HSPDP is to construct high-resolution records of environmental change, and to understand how those changes relate to early human evolution and cultural adaptations. The West Turkana-Kaitio (WTK) site was targeted due to the abundant archeological and paleontological artifacts and fossils discovered around the basin. We conducted XRD and XRF analyses on HSPDP-WTK core material to construct a high-resolution record of paleoenvironmental conditions in the Kenya Rift during the Early Pleistocene ( 1.9-1.35 Ma). Mineralogical and geochemical trends were also used to identify the diagenetic history of fluviolacustrine sediments in the basin. The bulk mineralogy is comprised of mostly detrital feldspars, muscovite, α-quartz, and carbonates. Zeolites are present in intervals throughout the core, possibly suggesting pulses of increased salinity. Oxides and S-bearing minerals are abundant from 100-170 mbs, which may be indicative of redox and or hydrothermal processes in that interval. The lowermost portion of the core contains α- and β-quartz, pyrite and zeolites, suggesting either low-oxygen saline conditions or hydrothermal activity. Oriented clay analysis indicated multiple intervals of diagenesis, with the illitization of smectite related to hydrothermal and or microbial activity. Clay analysis provided evidence for a low degree of illitization in the upper portion of the core, whereas mixed-layered illite-smectite (I/S) contained 30-50% illite proximal to fault breccia and up to 70% illite below the faulted section, indicative of significant alteration in the lowermost portion of the core. Coupled mineralogical and geochemical analysis revealed a complex alteration history in the basin indicated by: 1) the presence of mixed-layer I/S throughout the 216 m core; 2) pronounced alteration proximal to faulting; and 3) authigenic silicates and pyrite in the basal section of the core.

The First Year Experience in Australian Universities: Findings from Two Decades, 1994-­2014

ERIC Educational Resources Information Center

Baik, Chi; Naylor, Ryan; Arkoudis, Sophie

2015-01-01

This report provides an analysis of trends over a twenty year period in the attitudes and experiences of first year students in Australian universities. It is based on the national survey of first year students undertaken by the Melbourne Centre for the Study of Higher Education at five-yearly intervals since 1994. Dramatic changes have taken…

Paraquat Induced Changes in Reserve Carbohydrates, Fatty Acids and Oleoresin Content of Young Slash Pines

Treesearch

Claud L. Brown; Terry R. Clason; Jerry L. Michael

1976-01-01

Paraquat was fed into the terminal leaders of five-year-old slash pine trees and collected at weekly intervals for 4 weeks.Cytological observations showed a decrease in starch levels and a corresponding increase in content of oleoresin. Quantitative analysis indicated a decrease in starch accompanying increases in fatty acids, monoterpenes, and resin acids.

Time-dependent influence of sensorimotor set on automatic responses in perturbed stance

NASA Technical Reports Server (NTRS)

Chong, R. K.; Horak, F. B.; Woollacott, M. H.; Peterson, B. W. (Principal Investigator)

1999-01-01

These experiments tested the hypothesis that the ability to change sensorimotor set quickly for automatic responses depends on the time interval between successive surface perturbations. Sensorimotor set refers to the influence of prior experience or context on the state of the sensorimotor system. Sensorimotor set for postural responses was influenced by first giving subjects a block of identical backward translations of the support surface, causing forward sway and automatic gastrocnemius responses. The ability to change set quickly was inferred by measuring the suppression of the stretched antagonist gastrocnemius responses to toes-up rotations causing backward sway, following the translations. Responses were examined under short (10-14 s) and long (19-24 s) inter-trial intervals in young healthy subjects. The results showed that subjects in the long-interval group changed set immediately by suppressing gastrocnemius to 51% of translation responses within the first rotation and continued to suppress them over succeeding rotations. In contrast, subjects in the short-interval group did not change set immediately, but required two or more rotations to suppress gastrocnemius responses. By the last rotation, the short-interval group suppressed gastrocnemius responses to 33%, similar to the long-interval group of 29%. Associated surface plantarflexor torque resulting from these responses showed similar results. When rotation and translation perturbations alternated, however, the short-interval group was not able to suppress gastrocnemius responses to rotations as much as the long-interval group, although they did suppress more than in the first rotation trial after a series of translations. Set for automatic responses appears to linger, from one trial to the next. Specifically, sensorimotor set is more difficult to change when surface perturbations are given in close succession, making it appear as if set has become progressively stronger. A strong set does not mean that responses become larger over consecutive trials. Rather, it is inferred by the extent of difficulty in changing a response when it is appropriate to do so. These results suggest that the ability to change sensorimotor set quickly is sensitive to whether the change is required after a long or a short series of a prior different response, which in turn depends on the time interval between successive trials. Different rate of gastrocnemius suppression to toes-up rotation of the support surface have been reported in previous studies. This may be partially explained by different inter-trial time intervals demonstrated in this study.

Sex Differences in the Generalization of Fear as a Function of Retention Intervals

ERIC Educational Resources Information Center

Lynch, Joseph, III; Cullen, Patrick K.; Jasnow, Aaron M.; Riccio, David C.

2013-01-01

In previous studies using male rodents, context change disrupted a fear response at a short, but not a long, retention interval. Here, we examined the effects of context changes on fear responses as a function of time in male and female rats. Males displayed context discrimination at all intervals, whereas females exhibited generalization by 5 d.…

Credible occurrence probabilities for extreme geophysical events: earthquakes, volcanic eruptions, magnetic storms

USGS Publications Warehouse

Love, Jeffrey J.

2012-01-01

Statistical analysis is made of rare, extreme geophysical events recorded in historical data -- counting the number of events $k$ with sizes that exceed chosen thresholds during specific durations of time $\\tau$. Under transformations that stabilize data and model-parameter variances, the most likely Poisson-event occurrence rate, $k/\\tau$, applies for frequentist inference and, also, for Bayesian inference with a Jeffreys prior that ensures posterior invariance under changes of variables. Frequentist confidence intervals and Bayesian (Jeffreys) credibility intervals are approximately the same and easy to calculate: $(1/\\tau)[(\\sqrt{k} - z/2)^{2},(\\sqrt{k} + z/2)^{2}]$, where $z$ is a parameter that specifies the width, $z=1$ ($z=2$) corresponding to $1\\sigma$, $68.3\\%$ ($2\\sigma$, $95.4\\%$). If only a few events have been observed, as is usually the case for extreme events, then these "error-bar" intervals might be considered to be relatively wide. From historical records, we estimate most likely long-term occurrence rates, 10-yr occurrence probabilities, and intervals of frequentist confidence and Bayesian credibility for large earthquakes, explosive volcanic eruptions, and magnetic storms.

Monthly and annual percentage levels of wind speed differences computed by using FPS-16 radar/Jimsphere wind profile data from Cape Kennedy, Florida

NASA Technical Reports Server (NTRS)

Susko, M.; Kaufman, J. W.

1973-01-01

The percentage levels of wind speed differences are presented computed from sequential FPS-16 radar/Jimsphere wind profiles. The results are based on monthly profiles obtained from December 1964 to July 1970 at Cape Kennedy, Florida. The profile sequences contain a series of three to ten Jimspheres released at approximately 1.5-hour intervals. The results given are the persistence analysis of wind speed difference at 1.5-hour intervals to a maximum time interval of 12 hours. The monthly percentage of wind speed differences and the annual percentage of wind speed differences are tabulated. The percentage levels are based on the scalar wind speed changes calculated over an altitude interval of approximately 50 meters and printed out every 25 meters as a function of initial wind speed within each five-kilometer layer from near sea level to 20 km. In addition, analyses were made of the wind speed difference for the 0.2 to 1 km layer as an aid for studies associated with take-off and landing of the space shuttle.

Changes in apparent duration follow shifts in perceptual timing

PubMed Central

Bruno, Aurelio; Ayhan, Inci; Johnston, Alan

2015-01-01

It is well established that the apparent duration of moving visual objects is greater at higher as compared to slower speeds. Here we report the effects of acceleration and deceleration on the perceived duration of a drifting grating with average speed kept constant (10°/s).For acceleration, increasing the speed range progressively reduced perceived duration. The magnitude of apparent duration compression was determined by speed rather than temporal frequency and was proportional to speed range (independent of standard duration) rather than acceleration. The perceived duration reduction was also proportional to the standard length. The effects of increases and decreases in speed were highly asymmetric. Reducing speed through the interval induced a moderate increase in perceived duration. These results could not be explained by changes in apparent onset or offset or differences in perceived average speed between intervals containing increasing speed and intervals containing decreasing speed. Paradoxically, for intervals combining increasing speed and decreasing speed, compression only occurred when increasing speed occurred in the second half of the interval. We show that this pattern of results in the duration domain was concomitant with changes in the reported direction of apparent motion of Gaussian blobs, embedded in intervals of increasing or decreasing speed, that could be predicted from adaptive changes in the temporal impulse response function. We detected similar changes after flicker adaptation, suggesting that the two effects might be linked through changes in the temporal tuning of visual filters. PMID:26024450

Fuzzy interval Finite Element/Statistical Energy Analysis for mid-frequency analysis of built-up systems with mixed fuzzy and interval parameters

NASA Astrophysics Data System (ADS)

Yin, Hui; Yu, Dejie; Yin, Shengwen; Xia, Baizhan

2016-10-01

This paper introduces mixed fuzzy and interval parametric uncertainties into the FE components of the hybrid Finite Element/Statistical Energy Analysis (FE/SEA) model for mid-frequency analysis of built-up systems, thus an uncertain ensemble combining non-parametric with mixed fuzzy and interval parametric uncertainties comes into being. A fuzzy interval Finite Element/Statistical Energy Analysis (FIFE/SEA) framework is proposed to obtain the uncertain responses of built-up systems, which are described as intervals with fuzzy bounds, termed as fuzzy-bounded intervals (FBIs) in this paper. Based on the level-cut technique, a first-order fuzzy interval perturbation FE/SEA (FFIPFE/SEA) and a second-order fuzzy interval perturbation FE/SEA method (SFIPFE/SEA) are developed to handle the mixed parametric uncertainties efficiently. FFIPFE/SEA approximates the response functions by the first-order Taylor series, while SFIPFE/SEA improves the accuracy by considering the second-order items of Taylor series, in which all the mixed second-order items are neglected. To further improve the accuracy, a Chebyshev fuzzy interval method (CFIM) is proposed, in which the Chebyshev polynomials is used to approximate the response functions. The FBIs are eventually reconstructed by assembling the extrema solutions at all cut levels. Numerical results on two built-up systems verify the effectiveness of the proposed methods.

Iron, Hematological Parameters and Blood Plasma Lipid Profile in Vitamin D Supplemented and Non-Supplemented Young Soccer Players Subjected to High-Intensity Interval Training.

PubMed

Jastrzebska, Maria; Kaczmarczyk, Mariusz; Suárez, Arturo Diaz; Sánchez, Guillermo Felipe López; Jastrzebska, Joanna; Radziminski, Lukasz; Jastrzebski, Zbigniew

2017-01-01

Vitamin D deficiency has been associated with increased risk for cardiovascular disease and anemia. Vitamin D-related changes in lipid profile have been studied extensively but the relationship between vitamin D and lipid metabolism is not completely understood. As both vitamin D and intermittent training may potentially affect iron and lipid metabolism, the aim of the study was to evaluate whether a daily supplementation of vitamin D can modulate the response of hematological and lipid parameters to high-intensity interval training (HIIT) in soccer players. Thirty-six young elite junior soccer players were included in the placebo-controlled, double-blind study. Participants were non-randomly allocated into either a supplemented group (SG, n=20, HIIT and 5,000 IU of vitamin D daily) or placebo group (PG, n=16, HIIT and sunflower oil). Hematological parameters were ascertained before and after the 8-wk training. The change score (post- and pre-training difference) was calculated for each individual and the mean change score (MCS) was compared between SG and PG using the t test and analysis of covariance. There were no differences between SG and PG at baseline. The red and white cell count, hemoglobin, hematocrit, MCHC, ferritin, and HDL-cholesterol changed significantly over the 8-wk HIIT. However, no significant differences in MCS were observed between SG and PG for any variable. A daily vitamin D supplement did not have any impact on alteration in hematological or lipid parameters in young soccer players in the course of high-intensity interval training.

Early Cerebral Blood Volume Changes Predict Progression After Convection-Enhanced Delivery of Topotecan for Recurrent Malignant Glioma.

PubMed

Surapaneni, Krishna; Kennedy, Benjamin C; Yanagihara, Ted K; DeLaPaz, Robert; Bruce, Jeffrey N

2015-07-01

To assess whether early changes in enhancing tumor volume (eTV) and relative cerebral blood volume (rCBV) 1 month after convection-enhanced delivery of topotecan in patients with recurrent malignant glioma correlated with 6-month disease progression status. Sixteen patients were enrolled in a Phase Ib trial of convection-enhanced delivery of topotecan for recurrent malignant glioma. Each patient was evaluated with serial follow-up magnetic resonance imaging at baseline and at 4- to 8-week intervals. Changes at 1 month compared with baseline in eTV and rCBV were evaluated as potential predictors of 6-month progression status, classified as either progressive disease or nonprogressive disease. Relationships between percent changes in eTV and rCBV at 1 month with the probability of progressive disease at 6 months were estimated by the use of logistic regression analysis. Receiver operating characteristic curves for varying percent change thresholds in eTV and rCBV were evaluated by the use of 6-month progressive disease as the reference. There was a significant difference in the percent change in rCBV at 1 month in patients with progressive disease compared with those with nonprogressive disease at 6 months (+12% vs. -29%, P = 0.02). Logistic regression analysis demonstrated on average that a 10% increase in rCBV at 1 month after convection-enhanced delivery of topotecan was associated with 1.7 times the odds of developing progressive disease at 6 months (95% confidence interval [CI] 1.0-2.9 P = 0.05). Receiver operating characteristic analysis for determining progressive disease at 6 months showed a greater area under the curve with rCBV (0.867; 95% CI 0.66-1.00) than with change in enhancing tumor volume (0.767; 95% CI 0.51-1.00). In this selected population of patients with recurrent malignant glioma treated with convection-enhanced delivery of topotecan, early changes in rCBV at 4 weeks after therapy may help predict progression status at 6 months. Copyright © 2015 Elsevier Inc. All rights reserved.

Regional Sediment Budget of the Columbia River Littoral Cell, USA

USGS Publications Warehouse

Buijsman, Maarten C.; Sherwood, C.R.; Gibbs, A.E.; Gelfenbaum, G.; Kaminsky, G.M.; Ruggiero, P.; Franklin, J.

2002-01-01

Summary -- In this Open-File Report we present calculations of changes in bathymetric and topographic volumes for the Grays Harbor, Willapa Bay, and Columbia River entrances and the adjacent coasts of North Beach, Grayland Plains, Long Beach, and Clatsop Plains for four intervals: pre-jetty - 1920s (Interval 1), 1920s - 1950s (Interval 2), 1950s - 1990s (Interval 3), and 1920s 1990s (Interval 4). This analysis is part of the Southwest Washington Coastal Erosion Study (SWCES), the goals of which are to understand and predict the morphologic behavior of the Columbia River littoral cell on a management scale of tens of kilometers and decades. We obtain topographic Light Detection and Ranging (LIDAR) data from a joint project by the U.S. Geological Survey (USGS), National Oceanic and Atmospheric Administration (NOAA), National Aeronautic and Space Administration (NASA), and the Washington State Department of Ecology (DOE) and bathymetric data from the U.S. Coast and Geodetic Survey (USC&GS), U.S. Army Corps of Engineers (USACE), USGS, and the DOE. Shoreline data are digitized from T-Sheets and aerial photographs from the USC&GS and National Ocean Service (NOS). Instead of uncritically adjusting each survey to NAVD88, a common vertical land-based datum, we adjust some surveys to produce optimal results according to the following criteria. First, we minimize offsets in overlapping surveys within the same era, and second, we minimize bathymetric changes (relative to the 1990s) in deep water, where we assume minimal change has taken place. We grid bathymetric and topographic datasets using kriging and triangulation algorithms, calculate bathymetric-change surfaces for each interval, and calculate volume changes within polygons that are overlaid on the bathymetric-change surfaces. We find similar morphologic changes near the entrances to Grays Harbor and the Columbia River following jetty construction between 1898 and 1916 at the Grays Harbor entrance and between 1885 and 1913 at the Columbia River entrance. The inlets and inner deltas eroded and the outer deltas moved offshore and accreted. The adjacent coasts experienced accretion over alongshore distances of tens of kilometers. North of the Grays Harbor entrance along North Beach and north of the Columbia River entrance along Long Beach the shoreface and the beach-dune complex mainly prograded, whereas south of the Grays Harbor entrance along Grayland Plains and south of the Columbia River entrance along Clatsop Plains the beach-dune complex above -10 m NAVD88 prograded and the shoreface between approximately -30 m and -10 m NAVD88 eroded. In the decades following jetty construction, the rates of erosion and accretion at the entrances decreased and the centers of deposition along the adjacent coasts moved away from the entrances. The rates of change have decreased, suggesting the systems are approaching dynamic equilibrium. Exceptions to this behaviour are the accretion of the beach-dune complex of Long Beach, the erosion of Cape Shoalwater, and the northward migration of the Willapa Bay ebb-tidal delta during all intervals. The net shoreline advance of Long Beach increases from 0.28 m/yr in pre-jetty conditions to 3.78 m/yr during Interval 4. The erosion of Cape Shoalwater and the northward migration of the Willapa Bay ebb-tidal delta are related to the northern migration of the Willapa Bay North Channel. Volume changes at the Grays Harbor, Willapa Bay, and Columbia River entrances and the Columbia River estuary are balanced against losses and gains due to littoral transport and sand supply from the Columbia River. Based on these sediment balances, we infer the following pathways: sand that eroded from the inlets and inner deltas at the Grays Harbor and Columbia River entrances moved offshore and northward to accrete the outer deltas and the beaches to the north; sand from the south flank of the Grays Harbor delta and shelf along Grayland Plains moved onshore to accrete th

Multivariate Analysis of Remains of Molluscan Foods Consumed by Latest Pleistocene and Holocene Humans in Nerja Cave, Málaga, Spain

NASA Astrophysics Data System (ADS)

Serrano, Francisco; Guerra-Merchán, Antonio; Lozano-Francisco, Carmen; Vera-Peláez, José Luis

1997-09-01

Nerja Cave is a karstic cavity used by humans from Late Paleolithic to post-Chalcolithic times. Remains of molluscan foods in the uppermost Pleistocene and Holocene sediments were studied with cluster analysis and principal components analysis, in both Qand Rmodes. The results from cluster analysis distinguished interval groups mainly in accordance with chronology and distinguished assemblages of species mainly according to habitat. Significant changes in the shellfish diet through time were revealed. In the Late Magdalenian, most molluscs consumed consisted of pulmonate gastropods and species from sandy sea bottoms. The Epipaleolithic diet was more varied and included species from rocky shorelines. From the Neolithic onward most molluscs consumed were from rocky shorelines. From the principal components analysis in Qmode, the first factor reflected mainly changes in the predominant capture environment, probably because of major paleogeographic changes. The second factor may reflect selective capture along rocky coastlines during certain times. The third factor correlated well with the sea-surface temperature curve in the western Mediterranean (Alboran Sea) during the late Quaternary.

Within-Subject Testing of the Signaled-Reinforcement Effect on Operant Responding as Measured by Response Rate and Resistance to Change

ERIC Educational Resources Information Center

Reed, Phil; Doughty, Adam H.

2005-01-01

Response rates under random-interval schedules are lower when a brief (500 ms) signal accompanies reinforcement than when there is no signal. The present study examined this signaled-reinforcement effect and its relation to resistance to change. In Experiment 1, rats responded on a multiple random-interval 60-s random-interval 60-s schedule, with…

Changes in the Hurst exponent of heartbeat intervals during physical activity

NASA Astrophysics Data System (ADS)

Martinis, M.; Knežević, A.; Krstačić, G.; Vargović, E.

2004-07-01

The fractal scaling properties of the heartbeat time series are studied in different controlled ergometric regimes using both the improved Hurst rescaled range (R/S) analysis and the detrended fluctuation analysis (DFA). The long-time “memory effect” quantified by the value of the Hurst exponent H>0.5 is found to increase during progressive physical activity in healthy subjects, in contrast to those having stable angina pectoris, where it decreases. The results are also supported by the detrended fluctuation analysis. We argue that this finding may be used as a useful new diagnostic parameter for short heartbeat time series.

Practicability of monitoring soil Cd, Hg, and Pb pollution based on a geochemical survey in China.

PubMed

Xia, Xueqi; Yang, Zhongfang; Li, Guocheng; Yu, Tao; Hou, Qingye; Mutelo, Admire Muchimamui

2017-04-01

Repeated visiting, i.e., sampling and analysis at two or more temporal points, is one of the important ways of monitoring soil heavy metal contamination. However, with the concern about the cost, determination of the number of samples and the temporal interval, and their capability to detect a certain change is a key technical problem to be solved. This depends on the spatial variation of the parameters in the monitoring units. The "National Multi-Purpose Regional Geochemical Survey" (NMPRGS) project in China, acquired the spatial distribution of heavy metals using a high density sampling method in the most arable regions in China. Based on soil Cd, Hg, and Pb data and taking administrative regions as the monitoring units, the number of samples and temporal intervals that may be used for monitoring soil heavy metal contamination were determined. It was found that there is a large variety of spatial variation of the elements in each NMPRGS region. This results in the difficulty in the determination of the minimum detectable changes (MDC), the number of samples, and temporal intervals for revisiting. This paper recommends a suitable set of the number of samples (n r ) for each region under the balance of cost, practicability, and monitoring precision. Under n r , MDC values are acceptable for all the regions, and the minimum temporal intervals are practical with the range of 3.3-13.3 years. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigating the Genetic Architecture of the PR Interval Using Clinical Phenotypes.

PubMed

Mosley, Jonathan D; Shoemaker, M Benjamin; Wells, Quinn S; Darbar, Dawood; Shaffer, Christian M; Edwards, Todd L; Bastarache, Lisa; McCarty, Catherine A; Thompson, Will; Chute, Christopher G; Jarvik, Gail P; Crosslin, David R; Larson, Eric B; Kullo, Iftikhar J; Pacheco, Jennifer A; Peissig, Peggy L; Brilliant, Murray H; Linneman, James G; Witte, John S; Denny, Josh C; Roden, Dan M

2017-04-01

One potential use for the PR interval is as a biomarker of disease risk. We hypothesized that quantifying the shared genetic architectures of the PR interval and a set of clinical phenotypes would identify genetic mechanisms contributing to PR variability and identify diseases associated with a genetic predictor of PR variability. We used ECG measurements from the ARIC study (Atherosclerosis Risk in Communities; n=6731 subjects) and 63 genetically modulated diseases from the eMERGE network (Electronic Medical Records and Genomics; n=12 978). We measured pairwise genetic correlations (rG) between PR phenotypes (PR interval, PR segment, P-wave duration) and each of the 63 phenotypes. The PR segment was genetically correlated with atrial fibrillation (rG=-0.88; P =0.0009). An analysis of metabolic phenotypes in ARIC also showed that the P wave was genetically correlated with waist circumference (rG=0.47; P =0.02). A genetically predicted PR interval phenotype based on 645 714 single-nucleotide polymorphisms was associated with atrial fibrillation (odds ratio=0.89 per SD change; 95% confidence interval, 0.83-0.95; P =0.0006). The differing pattern of associations among the PR phenotypes is consistent with analyses that show that the genetic correlation between the P wave and PR segment was not significantly different from 0 (rG=-0.03 [0.16]). The genetic architecture of the PR interval comprises modulators of atrial fibrillation risk and obesity. © 2017 American Heart Association, Inc.

Risk-based maintenance of ethylene oxide production facilities.

PubMed

Khan, Faisal I; Haddara, Mahmoud R

2004-05-20

This paper discusses a methodology for the design of an optimum inspection and maintenance program. The methodology, called risk-based maintenance (RBM) is based on integrating a reliability approach and a risk assessment strategy to obtain an optimum maintenance schedule. First, the likely equipment failure scenarios are formulated. Out of many likely failure scenarios, the ones, which are most probable, are subjected to a detailed study. Detailed consequence analysis is done for the selected scenarios. Subsequently, these failure scenarios are subjected to a fault tree analysis to determine their probabilities. Finally, risk is computed by combining the results of the consequence and the probability analyses. The calculated risk is compared against known acceptable criteria. The frequencies of the maintenance tasks are obtained by minimizing the estimated risk. A case study involving an ethylene oxide production facility is presented. Out of the five most hazardous units considered, the pipeline used for the transportation of the ethylene is found to have the highest risk. Using available failure data and a lognormal reliability distribution function human health risk factors are calculated. Both societal risk factors and individual risk factors exceeded the acceptable risk criteria. To determine an optimal maintenance interval, a reverse fault tree analysis was used. The maintenance interval was determined such that the original high risk is brought down to an acceptable level. A sensitivity analysis is also undertaken to study the impact of changing the distribution of the reliability model as well as the error in the distribution parameters on the maintenance interval.

Comparative factor analysis of the effect of postoperative peripheral parenteral nutrition on recovery of right lobe liver donors.

PubMed

Hsieh, Chia-En; Lin, Kuo-Hua; Lin, Chia-Cheng; Hwu, Yueh-Juen; Lin, Ping-Yi; Lin, Hui-Chuan; Ko, Chih-Jan; Wang, Su-Han; Chen, Yao-Li

2015-04-01

Intensive nutritional support can reduce the catabolic response, improve protein synthesis, and promote liver regeneration. This study examined whether postoperative peripheral parenteral nutrition may improve recovery and reduce the length of hospital stay in right lobe liver donors. In this retrospective study, we enrolled liver donors with residual liver volume < 50%. Donors were classified into 2 groups: donors who received (n = 44) or did not receive (n = 40) postoperative peripheral parenteral nutrition. Liver function tests included alanine aminotransferase and total bilirubin levels, and postoperative complications included pleural effusion, atelectasis, and wound complications. Hospital length of stay was included as a potential risk factor for the evaluation of the effect of postoperative peripheral parenteral nutrition on recovery of right lobe liver donors. Male sex (β, 22.04; 95% confidence interval: 6.22 - 37.86) was a significant predictor of changes in postoperative alanine aminotransferase level. Male sex (β, 0.045; 95% confidence interval: 0.16 - 37.86) and receipt of peripheral parenteral nutrition (β, -0.045; 95% confidence interval: -0.72 - 0.17) were significant predictors of changes in total bilirubin level. Postoperative atelectasis (P < .001), pleural effusion (P < .011), and total complications (P = .015) had significantly lower incidence in the peripheral parenteral nutrition than control group. Multivariate logistic regression showed that recipients of peripheral parenteral nutrition (odds ratio, 0.161; 95% confidence interval: 0.043 - 0.598) and age (odds ratio, 0.870; 95% confidence interval: 0.782 - 0.968) were significant preoperative risk factors for postoperative complications. Postoperative peripheral parenteral nutrition is associated with a lower incidence of pleural effusion and atelectasis, a more rapid recovery of hyperbilirubinemia, and shorter length of stay in right lobe liver donors.

Effects of climate change and anthropogenic modification on a disturbance-dependent species in a large riverine system

USGS Publications Warehouse

Zeigler, Sara; Catlin, Daniel H.; Bomberger Brown, M.; Fraser, J.D.; Dinan, Lauren R.; Hunt, Kelsi L.; Jorgensen, Joel G.; Karpanty, Sarah M.

2017-01-01

Humans have altered nearly every natural disturbance regime on the planet through climate and land-use change, and in many instances, these processes may have interacting effects. For example, projected shifts in temperature and precipitation will likely influence disturbance regimes already affected by anthropogenic fire suppression or river impoundments. Understanding how disturbance-dependent species respond to complex and interacting environmental changes is important for conservation efforts. Using field-based demographic and movement rates, we conducted a metapopulation viability analysis for piping plovers (Charadrius melodus), a threatened disturbance-dependent species, along the Missouri and Platte rivers in the Great Plains of North America. Our aim was to better understand current and projected future metapopulation dynamics given that natural disturbances (flooding or high-flow events) have been greatly reduced by river impoundments and that climate change could further alter the disturbance regime. Although metapopulation abundance has been substantially reduced under the current suppressed disturbance regime (high-flow return interval ~ 20 yr), it could grow if the frequency of high-flow events increases as predicted under likely climate change scenarios. We found that a four-year return interval would maximize metapopulation abundance, and all subpopulations in the metapopulation would act as sources at a return interval of 15 yr or less. Regardless of disturbance frequency, the presence of even a small, stable source subpopulation buffered the metapopulation and sustained a low metapopulation extinction risk. Therefore, climate change could have positive effects in ecosystems where disturbances have been anthropogenically suppressed when climatic shifts move disturbance regimes toward more historical patterns. Furthermore, stable source populations, even if unintentionally maintained through anthropogenic activities, may be critical for the persistence of metapopulations of early-successional species under both suppressed disturbance regimes and disturbance regimes where climate change has further altered disturbance frequency or scope.

Changes in Team Cognition after a Retention Interval: The Benefits of Mixing It up

ERIC Educational Resources Information Center

Gorman, Jamie C.; Cooke, Nancy J.

2011-01-01

This paper examines the retention of team cognition with changes in team membership. Hypotheses are developed from shared cognition and interactive team cognition theories. We report a study of the effects of Short (3-6 weeks) versus Long (10-13 weeks) retention intervals and change (Mixed) versus no change (Intact) in team membership during the…

Evaluating the efficiency of environmental monitoring programs

USGS Publications Warehouse

Levine, Carrie R.; Yanai, Ruth D.; Lampman, Gregory G.; Burns, Douglas A.; Driscoll, Charles T.; Lawrence, Gregory B.; Lynch, Jason; Schoch, Nina

2014-01-01

Statistical uncertainty analyses can be used to improve the efficiency of environmental monitoring, allowing sampling designs to maximize information gained relative to resources required for data collection and analysis. In this paper, we illustrate four methods of data analysis appropriate to four types of environmental monitoring designs. To analyze a long-term record from a single site, we applied a general linear model to weekly stream chemistry data at Biscuit Brook, NY, to simulate the effects of reducing sampling effort and to evaluate statistical confidence in the detection of change over time. To illustrate a detectable difference analysis, we analyzed a one-time survey of mercury concentrations in loon tissues in lakes in the Adirondack Park, NY, demonstrating the effects of sampling intensity on statistical power and the selection of a resampling interval. To illustrate a bootstrapping method, we analyzed the plot-level sampling intensity of forest inventory at the Hubbard Brook Experimental Forest, NH, to quantify the sampling regime needed to achieve a desired confidence interval. Finally, to analyze time-series data from multiple sites, we assessed the number of lakes and the number of samples per year needed to monitor change over time in Adirondack lake chemistry using a repeated-measures mixed-effects model. Evaluations of time series and synoptic long-term monitoring data can help determine whether sampling should be re-allocated in space or time to optimize the use of financial and human resources.

Tp-e Interval, Tp-e/QTc Ratio, and Fragmented QRS Are Correlated with the Severity of Liver Cirrhosis.

PubMed

Akboga, Mehmet Kadri; Yuksel, Mahmut; Balci, Kevser Gulcihan; Kaplan, Mustafa; Cay, Serkan; Gokbulut, Volkan; Yayla, Cagri; Ertem, Ahmet Goktug; Ayhan, Meral Akdogan; Topaloglu, Serkan; Aras, Dursun

2017-01-01

Arrhythmias and electrocardiographic changes are reported in several noncardiac diseases, including liver cirrhosis (LC). We intended to evaluate the interval from the peak to the end of the electrocardiographic T wave (Tp-e), Tp-e/QTc ratio, and fQRS as presumed markers of arrhythmias in LC. In this cross-sectional study, a total of 88 consecutive patients with LC according to clinical, biological, ultrasonographic, or histological criteria and 73 control subjects were enrolled. The severity of cirrhosis was classified according to Pugh-Child's classification and Model for End-Stage Liver Disease (MELD) score. Tp-e interval, Tp-e/QTc ratio, and fQRS rates were measured from the 12-lead electrocardiogram. Tp-e interval, Tp-e/QTc ratio and fQRS rates were significantly increased in parallel to the severity of LC (P < 0.001, P < 0.001, and P = 0.003, respectively). In correlation analysis, Pugh-Child stage showed a significantly positive correlation with Tp-e interval (r = 0.462, P < 0.001), QTc interval (r = 0.373, P < 0.001), Tp-e/QTc ratio (r = 0.352, P < 0.001), and fQRS (r = 0.407, P < 0.001). Furthermore, Tp-e interval (r = 0.414, P < 0.001) and Tp-e/QTc ratio (r = 0.426, P< 0.001) had significant positive correlation with MELD score. Our study demonstrated that Tp-e interval, Tp-e/QTc ratios, and fQRS rates were significantly increased in parallel to the severity of LC. Thus, these findings may implicate that Tp-e interval, Tp-e/QTc ratio, and fQRS may be novel and useful indicators for prediction of arrhythmias in LC. © 2016 Wiley Periodicals, Inc.

High-intensity interval exercise training for public health: a big HIT or shall we HIT it on the head?

PubMed

Biddle, Stuart J H; Batterham, Alan M

2015-07-18

The efficacy of high-intensity interval training for a broad spectrum of cardio-metabolic health outcomes is not in question. Rather, the effectiveness of this form of exercise is at stake. In this paper we debate the issues concerning the likely success or failure of high-intensity interval training interventions for population-level health promotion. Biddle maintains that high-intensity interval training cannot be a viable public health strategy as it will not be adopted or maintained by many people. This conclusion is based on an analysis of perceptions of competence, the psychologically aversive nature of high-intensity exercise, the affective component of attitudes, the less conscious elements of motivated behaviour that reflect our likes and dislikes, and analysis using the RE-AIM framework. Batterham argues that this appraisal is based on a constrained and outmoded definition of high-intensity interval training and that truly practical and scalable protocols have been - and continue to be - developed. He contends that the purported displeasure associated with this type of exercise has been overstated. Biddle suggests that the way forward is to help the least active become more active rather than the already active to do more. Batterham claims that traditional physical activity promotion has been a spectacular failure. He proposes that, within an evolutionary health promotion framework, high-intensity interval training could be a successful population strategy for producing rapid physiological adaptations benefiting public health, independent of changes in total physical activity energy expenditure. Biddle recommends that we focus our attention elsewhere if we want population-level gains in physical activity impacting public health. His conclusion is based on his belief that high-intensity interval training interventions will have limited reach, effectiveness, and adoption, and poor implementation and maintenance. In contrast, Batterham maintains that there is genuine potential for scalable, enjoyable high-intensity interval exercise interventions to contribute substantially to addressing areas of public health priority, including prevention and treatment of Type 2 diabetes and cardiovascular disease.

Terrain-analysis procedures for modeling radar backscatter

USGS Publications Warehouse

Schaber, Gerald G.; Pike, Richard J.; Berlin, Graydon Lennis

1978-01-01

The collection and analysis of detailed information on the surface of natural terrain are important aspects of radar-backscattering modeling. Radar is especially sensitive to surface-relief changes in the millimeter- to-decimeter scale four conventional K-band (~1-cm wavelength) to L-band (~25-cm wavelength) radar systems. Surface roughness statistics that characterize these changes in detail have been generated by a comprehensive set of seven programmed calculations for radar-backscatter modeling from sets of field measurements. The seven programs are 1) formatting of data in readable form for subsequent topographic analysis program; 2) relief analysis; 3) power spectral analysis; 4) power spectrum plots; 5) slope angle between slope reversals; 6) slope angle against slope interval plots; and 7) base length slope angle and curvature. This complete Fortran IV software package, 'Terrain Analysis', is here presented for the first time. It was originally developed a decade ago for investigations of lunar morphology and surface trafficability for the Apollo Lunar Roving Vehicle.

Temporal Stability of the Dutch Version of the Wechsler Memory Scale-Fourth Edition (WMS-IV-NL).

PubMed

Bouman, Zita; Hendriks, Marc P H; Aldenkamp, Albert P; Kessels, Roy P C

2015-01-01

The Wechsler Memory Scale-Fourth Edition (WMS-IV) is one of the most widely used memory batteries. We examined the test-retest reliability, practice effects, and standardized regression-based (SRB) change norms for the Dutch version of the WMS-IV (WMS-IV-NL) after both short and long retest intervals. The WMS-IV-NL was administered twice after either a short (M = 8.48 weeks, SD = 3.40 weeks, range = 3-16) or a long (M = 17.87 months, SD = 3.48, range = 12-24) retest interval in a sample of 234 healthy participants (M = 59.55 years, range = 16-90; 118 completed the Adult Battery; and 116 completed the Older Adult Battery). The test-retest reliability estimates varied across indexes. They were adequate to good after a short retest interval (ranging from .74 to .86), with the exception of the Visual Working Memory Index (r = .59), yet generally lower after a long retest interval (ranging from .56 to .77). Practice effects were only observed after a short retest interval (overall group mean gains up to 11 points), whereas no significant change in performance was found after a long retest interval. Furthermore, practice effect-adjusted SRB change norms were calculated for all WMS-IV-NL index scores. Overall, this study shows that the test-retest reliability of the WMS-IV-NL varied across indexes. Practice effects were observed after a short retest interval, but no evidence was found for practice effects after a long retest interval from one to two years. Finally, the SRB change norms were provided for the WMS-IV-NL.

A diameter growth model for the SRS FIA

Treesearch

David Gartner

2015-01-01

Changes in the national Forest Inventory and Analysis (FIA) processing system required the Southern Research Station’s FIA unit to create a diameter growth model to estimate the growth of trees that could not be measured at both ends of a measurement interval. Examples of such trees are trees that have died or been harvested, and trees that grow over the minimum...

Whys and Hows of the Parameterized Interval Analyses: A Guide for the Perplexed

NASA Astrophysics Data System (ADS)

Elishakoff, I.

2013-10-01

Novel elements of the parameterized interval analysis developed in [1, 2] are emphasized in this response, to Professor E.D. Popova, or possibly to others who may be perplexed by the parameterized interval analysis. It is also shown that the overwhelming majority of comments by Popova [3] are based on a misreading of our paper [1]. Partial responsibility for this misreading can be attributed to the fact that explanations provided in [1] were laconic. These could have been more extensive in view of the novelty of our approach [1, 2]. It is our duty, therefore, to reiterate, in this response, the whys and hows of parameterization of intervals, introduced in [1] to incorporate the possibly available information on dependencies between various intervals describing the problem at hand. This possibility appears to have been discarded by the standard interval analysis, which may, as a result, lead to overdesign, leading to the possible divorce of engineers from the otherwise beautiful interval analysis.

Ehrenfest model with large jumps in finance

NASA Astrophysics Data System (ADS)

Takahashi, Hisanao

2004-02-01

Changes (returns) in stock index prices and exchange rates for currencies are argued, based on empirical data, to obey a stable distribution with characteristic exponent α<2 for short sampling intervals and a Gaussian distribution for long sampling intervals. In order to explain this phenomenon, an Ehrenfest model with large jumps (ELJ) is introduced to explain the empirical density function of price changes for both short and long sampling intervals.

A single-loop optimization method for reliability analysis with second order uncertainty

NASA Astrophysics Data System (ADS)

Xie, Shaojun; Pan, Baisong; Du, Xiaoping

2015-08-01

Reliability analysis may involve random variables and interval variables. In addition, some of the random variables may have interval distribution parameters owing to limited information. This kind of uncertainty is called second order uncertainty. This article develops an efficient reliability method for problems involving the three aforementioned types of uncertain input variables. The analysis produces the maximum and minimum reliability and is computationally demanding because two loops are needed: a reliability analysis loop with respect to random variables and an interval analysis loop for extreme responses with respect to interval variables. The first order reliability method and nonlinear optimization are used for the two loops, respectively. For computational efficiency, the two loops are combined into a single loop by treating the Karush-Kuhn-Tucker (KKT) optimal conditions of the interval analysis as constraints. Three examples are presented to demonstrate the proposed method.

Setting the Revisit Interval in Primary Care

PubMed Central

Schwartz, Lisa M; Woloshin, Steven; Wasson, John H; Renfrew, Roger A; Welch, H Gilbert

1999-01-01

OBJECTIVE Although longitudinal care constitutes the bulk of primary care, physicians receive little guidance on the fundamental question of how to time follow-up visits. We sought to identify important predictors of the revisit interval and to describe the variability in how physicians set these intervals when caring for patients with common medical conditions. DESIGN Cross-sectional survey of physicians performed at the end of office visits for consecutive patients with hypertension, angina, diabetes, or musculoskeletal pain. PARTICIPANTS/SETTING One hundred sixty-four patients under the care of 11 primary care physicians in the Dartmouth Primary Care Cooperative Research Network. MEASUREMENTS The main outcome measures were the variability in mean revisit intervals across physicians and the proportion of explained variance by potential determinants of revisit intervals. We assessed the relation between the revisit interval (dependent variable) and three groups of independent variables, patient characteristics (e.g., age, physician perception of patient health), identification of individual physician, and physician characterization of the visit (e.g., routine visit, visit requiring a change in management, or visit occurring on a “hectic” day), using multiple regression that accounted for the natural grouping of patients within physician. MAIN RESULTS Revisit intervals ranged from 1 week to over 1 year. The most common intervals were 12 and 16 weeks. Physicians’ perception of fair-poor health status and visits involving a change in management were most strongly related to shorter revisit intervals. In multivariate analyses, patient characteristics explained about 18% of the variance in revisit intervals, and adding identification of the individual provider doubled the explained variance to about 40%. Physician characterization of the visit increased explained variance to 57%. The average revisit interval adjusted for patient characteristics for each of the 11 physicians varied from 4 to 20 weeks. Although all physicians lengthened revisit intervals for routine visits and shortened them when changing management, the relative ranking of mean revisit intervals for each physician changed little for different visit characterizations—some physicians were consistently long and others were consistently short. CONCLUSION Physicians vary widely in their recommendations for office revisits. Patient factors accounted for only a small part of this variation. Although physicians responded to visits in predictable ways, each physician appeared to have a unique set point for the length of the revisits interval. PMID:10203635

Neodymium isotope evolution of NW Tethyan upper ocean waters throughout the Cretaceous

NASA Astrophysics Data System (ADS)

Pucéat, Emmanuelle; Lécuyer, Christophe; Reisberg, Laurie

2005-08-01

Neodymium isotope compositions of twenty-four fish teeth, nineteen from the NW Tethys and five from different locations within the Tethys, are interpreted to reflect the evolution of Tethyan upper ocean water composition during the Cretaceous and used to track changes in erosional inputs to the NW Tethys and in oceanic circulation throughout the Cretaceous. The rather high ɛNd (up to - 7.6) of the NW Tethyan upper ocean waters recorded from the Late Berriasian to the Early Aptian and the absence of negative excursions during this interval support the presence of a permanent westward flowing Tethys Circumglobal Current (TCC). This implies that temperature variations during this time period, inferred from the oxygen isotope analysis of fish tooth enamel, were not driven by changes in surface oceanic currents, but rather by global climatic changes. The results presented here represent a significant advance over previously published Cretaceous seawater Nd isotope records. Our newly acquired data now allow the identification of two stages of low ɛNd values in the NW Tethys, during the Early Albian-Middle Albian interval (down to - 10) and the Santonian-Early Campanian (down to - 11.4), which alternate with two stages of higher ɛNd values (up to - 9) during the Late Albian-Turonian interval and the Maastrichtian. Used in conjunction with the oxygen isotope record, the fluctuations of ɛNd values can be related to major climatic, oceanographic, and tectonic events that appeared in the western Tethyan domain.

Effects of capacity limits, memory loss, and sound type in change deafness.

PubMed

Gregg, Melissa K; Irsik, Vanessa C; Snyder, Joel S

2017-11-01

Change deafness, the inability to notice changes to auditory scenes, has the potential to provide insights about sound perception in busy situations typical of everyday life. We determined the extent to which change deafness to sounds is due to the capacity of processing multiple sounds and the loss of memory for sounds over time. We also determined whether these processing limitations work differently for varying types of sounds within a scene. Auditory scenes composed of naturalistic sounds, spectrally dynamic unrecognizable sounds, tones, and noise rhythms were presented in a change-detection task. On each trial, two scenes were presented that were same or different. We manipulated the number of sounds within each scene to measure memory capacity and the silent interval between scenes to measure memory loss. For all sounds, change detection was worse as scene size increased, demonstrating the importance of capacity limits. Change detection to the natural sounds did not deteriorate much as the interval between scenes increased up to 2,000 ms, but it did deteriorate substantially with longer intervals. For artificial sounds, in contrast, change-detection performance suffered even for very short intervals. The results suggest that change detection is generally limited by capacity, regardless of sound type, but that auditory memory is more enduring for sounds with naturalistic acoustic structures.

Poincaré plot analysis of ultra-short-term heart rate variability during recovery from exercise in physically active men.

PubMed

Gomes, Rayana L; Marques Vanderlei, Luiz C; Garner, David M; Ramos Santana, Milana D; de Abreu, Luiz C; Valenti, Vitor E

2017-04-26

Recently there has been increasing interest in the study of ultra-short- term heart rate variability (HRV) in sports performance and exercise physiology. In order to improve standardization of this specific analysis, we evaluated the ultra-short-term HRV analysis through SD1Poincaré index to identify exercise induced responses. We investigated 35 physically active men aged between 18 and 35 years old. Volunteers performed physical exercise on treadmill with intensity of 6.0 km / hour + 1% slope in the first five minutes for physical "warming up." This was followed by 25 minutes with intensity equivalent to 60% of Vmax, with the same slope according to the Conconi threshold. HRV was analyzed in the following periods: the five-minute period before the exercise and the five-minute period immediately after the exercise, the five minutes were divided into five segments of 60 RR intervals. Ultra-short-term RMSSD and SD1 analysis were performed. Ultra-short-term RMSSD and SD1 were significantly (p<0.0001) reduced during the initial five minutes divided into five segments of 60 RR intervals compared to (at rest) control. Heart rate was significantly (p<0.0001) increased 1 min and 3 min immediately after exercise compared to (at rest) control. At rest ultra-short-term SD1 presented significant correlation with short-term (256 RR intervals) RMSSD (r=0.78; p<0.0001), HF (r=0.574; p=0.0007) and SD1 (r=0.78; p<0.0001). Additionally, visual analysis with the Poincaré plot detected changes in HRV after exercise. Ultra-short-term HRV analysis through Poincaré plot identified heart rate autonomic responses induced by aerobic exercise.

Within-Session Stability of Short-Term Heart Rate Variability Measurement

PubMed Central

2016-01-01

Abstract The primary aim of this study was to assess the retest stability of the short-term heart rate variability (HRV) measurement performed within one session and without the use of any intervention. Additionally, a precise investigation of the possible impact of intrinsic biological variation on HRV reliability was also performed. First, a single test-retest HRV measurement was conducted with 20-30 min apart from one another. Second, the HRV measurement was repeated in ten non-interrupted consecutive intervals. The lowest typical error (CV = 21.1%) was found for the square root of the mean squared differences of successive RR intervals (rMSSD) and the highest for the low frequency power (PLF) (CV = 93.9%). The standardized changes in the mean were trivial to small. The correlation analysis revealed the highest level for ln rMSSD (ICC = 0.87), while ln PLF represented the worst case (ICC = 0.59). The reliability indices for ln rMSSD in 10 consecutive intervals improved (CV = 9.9%; trivial standardized changes in the mean; ICC = 0.96). In conclusion, major differences were found in the reliability level between the HRV indices. The rMSSD demonstrated the highest reliability level. No substantial influence of intrinsic biological variation on the HRV reliability was observed. PMID:28149345

Infant speech-sound discrimination testing: effects of stimulus intensity and procedural model on measures of performance.

PubMed

Nozza, R J

1987-06-01

Performance of infants in a speech-sound discrimination task (/ba/ vs /da/) was measured at three stimulus intensity levels (50, 60, and 70 dB SPL) using the operant head-turn procedure. The procedure was modified so that data could be treated as though from a single-interval (yes-no) procedure, as is commonly done, as well as if from a sustained attention (vigilance) task. Discrimination performance changed significantly with increase in intensity, suggesting caution in the interpretation of results from infant discrimination studies in which only single stimulus intensity levels within this range are used. The assumptions made about the underlying methodological model did not change the performance-intensity relationships. However, infants demonstrated response decrement, typical of vigilance tasks, which supports the notion that the head-turn procedure is represented best by the vigilance model. Analysis then was done according to a method designed for tasks with undefined observation intervals [C. S. Watson and T. L. Nichols, J. Acoust. Soc. Am. 59, 655-668 (1976)]. Results reveal that, while group data are reasonably well represented across levels of difficulty by the fixed-interval model, there is a variation in performance as a function of time following trial onset that could lead to underestimation of performance in some cases.

In-Hospital Haloperidol Use and Perioperative Changes in QTc-Duration.

PubMed

Blom, M T; Jansen, S; de Jonghe, A; van Munster, B C; de Boer, A; de Rooij, S E; Tan, H L; van der Velde, N

2015-05-01

Haloperidol may prolong ECG QTc-duration but is often prescribed perioperatively to hip-fracture patients. We aimed to determine (1) how QTc-duration changes perioperatively, (2) whether low-dose haloperidol-use influences these changes, and (3) which clinical variables are associated with potentially dangerous perioperative QTc-prolongation (PD-QTc; increase >50 ms or to >500 ms). Prospective cohort study. Tertiary university teaching-hospital. Patients enrolled in a randomized controlled clinical trial of melatonin versus placebo on occurrence of delirium in hip-fracture patients. Data from ECGs made before and after hip surgery (1-3 days and/or 4-6 days post-surgery) were analyzed. QTc-duration was measured by hand, blinded for haloperidol and pre/post-surgery status. Clinical variables were measured at baseline. Mixed model analysis was used to estimate changes in QTc-duration. Risk-factors for PD-QTc were estimated by logistic regression analysis. We included 89 patients (mean age 84 years, 24% male); 39 were treated with haloperidol. Patients with normal pre-surgery QTc-duration (male ≤430 ms, female ≤450 ms) had a significant increase (mean 12 ms, SD 28) in QTc-duration. A significant decrease (mean 19 ms, SD 34) occurred in patients with prolonged pre-surgery QTc-duration (male >450ms, female >470 ms). Haloperidol-use did not influence the perioperative course of the QTc-interval (p=0.351). PD-QTc (n=8) was not associated with any of the measured risk-factors. QTc-duration changed differentially, increasing in patients with normal, but decreasing in patients with abnormal baseline QTc-duration. PD-QTc was not associated with haloperidol-use or other risk-factors. Low-dose oral haloperidol did not affect perioperative QTc-interval.

Flood Mapping in the Lower Mekong River Basin Using Daily MODIS Observations

NASA Technical Reports Server (NTRS)

Fayne, Jessica V.; Bolten, John D.; Doyle, Colin S.; Fuhrmann, Sven; Rice, Matthew T.; Houser, Paul R.; Lakshmi, Venkat

2017-01-01

In flat homogenous terrain such as in Cambodia and Vietnam, the monsoon season brings significant and consistent flooding between May and November. To monitor flooding in the Lower Mekong region, the near real-time NASA Flood Extent Product (NASA-FEP) was developed using seasonal normalized difference vegetation index (NDVI) differences from the 250 m resolution Moderate Resolution Imaging Spectroradiometer (MODIS) sensor compared to daily observations. The use of a percentage change interval classification relating to various stages of flooding reduces might be confusing to viewers or potential users, and therefore reducing the product usage. To increase the product usability through simplification, the classification intervals were compared with other commonly used change detection schemes to identify the change classification scheme that best delineates flooded areas. The percentage change method used in the NASA-FEP proved to be helpful in delineating flood boundaries compared to other change detection methods. The results of the accuracy assessments indicate that the -75% NDVI change interval can be reclassified to a descriptive 'flood' classification. A binary system was used to simplify the interpretation of the NASA-FEP by removing extraneous information from lower interval change classes.

Stimulus-to-matching-stimulus interval influences N1, P2, and P3b in an equiprobable Go/NoGo task.

PubMed

Steiner, Genevieve Z; Barry, Robert J; Gonsalvez, Craig J

2014-10-01

Previous research has shown that as the stimulus-to-matching-stimulus interval (including the target-to-target interval, TTI, and nontarget-to-nontarget interval, NNI) increases, the amplitude of the P300 ERP component increases systematically. Here, we extended previous P300 research and explored TTI and NNI effects on the various ERP components elicited in an auditory equiprobable Go/NoGo task. We also examined whether a similar mechanism was underpinning interval effects in early ERP components (e.g., N1). Thirty participants completed a specially-designed variable-ISI equiprobable task whilst their EEG activity was recorded. Component amplitudes were extracted using temporal PCA with unrestricted Varimax rotation. As expected, N1, P2, and P3b amplitudes increased as TTI and NNI increased, however, Processing Negativity (PN) and Slow Wave (SW) did not show the same systematic change with interval increments. To determine the origin of interval effects in sequential processing, a multiple regression analysis was conducted on each ERP component including stimulus type, interval, and all preceding components as predictors. These analyses showed that matching-stimulus interval predicted N1, P3b, and weakly predicted P2, but not PN or SW; SW was determined by P3b only. These results suggest that N1, P3b, and to some extent, P2, are affected by a similar temporal mechanism. However, the dissimilar pattern of results obtained for sequential ERP components indicates that matching-stimulus intervals are not affecting all aspects of stimulus processing. This argues against a global mechanism, such as a pathway-specific refractory effect, and suggests that stimulus processing is occurring in parallel pathways, some of which are not affected by temporal manipulations of matching-stimulus interval. Copyright © 2014 Elsevier B.V. All rights reserved.

Quantitative electromyography in ambulatory boys with Duchenne muscular dystrophy.

PubMed

Verma, Sumit; Lin, Jenny; Travers, Curtis; McCracken, Courtney; Shah, Durga

2017-12-01

This study's objective was to evaluate quantitative electromyography (QEMG) using multiple-motor-unit (multi-MUP) analysis in Duchenne muscular dystrophy (DMD). Ambulatory DMD boys, aged 5-15 years, were evaluated with QEMG at 6-month intervals over 14 months. EMG was performed in the right biceps brachii (BB) and tibialis anterior (TA) muscles. Normative QEMG data were obtained from age-matched healthy boys. Wilcoxon signed-rank tests were performed. Eighteen DMD subjects were enrolled, with a median age of 7 (interquartile range 7-10) years. Six-month evaluations were performed on 14 subjects. QEMG showed significantly abnormal mean MUP duration in BB and TA muscles, with no significant change over 6 months. QEMG is a sensitive electrophysiological marker of myopathy in DMD. Preliminary data do not reflect a significant change in MUP parameters over a 6-month interval; long-term follow-up QEMG studies are needed to understand its role as a biomarker for disease progression. Muscle Nerve 56: 1361-1364, 2017. © 2017 Wiley Periodicals, Inc.

Time-varying nonstationary multivariate risk analysis using a dynamic Bayesian copula

NASA Astrophysics Data System (ADS)

Sarhadi, Ali; Burn, Donald H.; Concepción Ausín, María.; Wiper, Michael P.

2016-03-01

A time-varying risk analysis is proposed for an adaptive design framework in nonstationary conditions arising from climate change. A Bayesian, dynamic conditional copula is developed for modeling the time-varying dependence structure between mixed continuous and discrete multiattributes of multidimensional hydrometeorological phenomena. Joint Bayesian inference is carried out to fit the marginals and copula in an illustrative example using an adaptive, Gibbs Markov Chain Monte Carlo (MCMC) sampler. Posterior mean estimates and credible intervals are provided for the model parameters and the Deviance Information Criterion (DIC) is used to select the model that best captures different forms of nonstationarity over time. This study also introduces a fully Bayesian, time-varying joint return period for multivariate time-dependent risk analysis in nonstationary environments. The results demonstrate that the nature and the risk of extreme-climate multidimensional processes are changed over time under the impact of climate change, and accordingly the long-term decision making strategies should be updated based on the anomalies of the nonstationary environment.

Human values and beliefs and concern about climate change: a Bayesian longitudinal analysis.

PubMed

Prati, Gabriele; Pietrantoni, Luca; Albanesi, Cinzia

2018-01-01

The aim of this study was to investigate the influence of human values on beliefs and concern about climate change using a longitudinal design and Bayesian analysis. A sample of 298 undergraduate/master students filled out the same questionnaire on two occasions at an interval of 2 months. The questionnaire included measures of beliefs and concern about climate change (i.e., perceived consequences, risk perception, and skepticism) and human values (i.e., the Portrait Values Questionnaire). After controlling for gender and the respective baseline score, universalism at Time 1 was associated with higher levels of perceived consequences of climate change and lower levels of climate change skepticism. Self-direction at Time 1 predicted Time 2 climate change risk perception and perceived consequences of climate change. Hedonism at Time 1 was associated with Time 2 climate change risk perception. The other human values at Time 1 were not associated with any of the measures of beliefs and concern about climate change at Time 2. The results of this study suggest that a focus on universalism and self-direction values seems to be a more successful approach to stimulate public engagement with climate change than a focus on other human values.

Arctic Climate and Terrestrial Vegetation Responses During the Middle to Late Eocene and Early Oligocene: Colder Winters Preceded Cool-Down.

NASA Astrophysics Data System (ADS)

Greenwood, D. R.; Eldrett, J.

2006-12-01

The late Eocene to early Oligocene is recognized as an interval of substantial change in the global climate, with isotopic proxies of climate indicating a significant drop in sea surface temperatures. Other studies have shown, however that at middle latitudes that terrestrial mean annual temperature did not change significantly over this interval, and that the major change was likely a shift towards a greater range of seasonal temperatures; colder winters and warmer summers. Previous analyses of high latitude (Arctic) middle Eocene climate using both leaf physiognomic analysis and qualitative analysis of identified nearest living relatives of terrestrial floras indicated upper microthermal environments (mean annual temp. or MAT ca 10°C but perhaps as high as 15°C, coldest month mean temp. or CMMT ca 0°C) for Axel Heiberg Island in the Arctic Archipelago, but did not address precipitation nor provide data on the Eocene-Oligocene transition in the Arctic. Presented here are new estimates of temperature and precipitation (annual and season amounts) for the Arctic based on NLR analysis of terrestrial plant palynomorphs (spores and pollen) from the ODP 913B and 985 cores from near Greenland. The record of climate for the Greenland cores show a similar climate in the middle Eocene to that previously estimated for Axel Heiberg Island further to the west, with MAT 10- 15°C but with CMMT >5°C. Precipitation was high (mean annual precip. or MAP >180 cm/yr), although with large uncertainties attached to the estimate. The climate proxy record for the late Eocene to early Oligocene shows a lack of change in MAT and MAP over the time interval. Consistent with other published records at middle latitudes, however, winter temperatures (as CMMT) show greater variability leading up to the E-O boundary, and consistently cooler values in the early Oligocene (CMMT <5°C) than recorded for most of the middle to late Eocene record (CMMT >5°C). Plant groups sensitive to freezing such as palms and the floating water fern Azolla were present in the warm parts of the record, but are absent from the latest Eocene and early Oligocene record. These data provide further evidence that the primary change in the global climate system in the E-O transition was a shift towards more extreme seasonal temperature ranges, rather than a drop in the mean temperature.

Human sinus arrhythmia as an index of vagal cardiac outflow

NASA Technical Reports Server (NTRS)

Eckberg, D. L.

1983-01-01

The human central vagal mechanisms were investigated by measuring the intervals between heartbeats during controlled breathing (at breathing intervals of 2.5-10 s and nominal tidal volumes of 1000 and 1500 ml) in six young men and women. It was found that as the breathing interval increased, the longest heart periods became longer, the shortest heart periods became shorter, and the peak-valley P-P intervals increased asymptotically. Peak-valley intervals also increased in proportion to tidal volume, although this influence was small. The phase angles between heart period changes and respiration were found to vary as linear functions of breathing interval. Heart period shortening began in inspiration at short breathing intervals and in expiration at long breathing intervals, while heart period lengthening began in early expiration at all breathing intervals studied. It is concluded that a close relationship exists between variations of respiratory depth and interval and the quantity, periodicity, and timing of vagal cardiac outflow in conscious humans. The results indicate that at usual breathing rates, phasic respiration-related changes of vagal motoneuron activity begin in expiration, progress slowly, and are incompletely expressed at fast breathing ratges.

Constructing Confidence Intervals for Reliability Coefficients Using Central and Noncentral Distributions.

ERIC Educational Resources Information Center

Weber, Deborah A.

Greater understanding and use of confidence intervals is central to changes in statistical practice (G. Cumming and S. Finch, 2001). Reliability coefficients and confidence intervals for reliability coefficients can be computed using a variety of methods. Estimating confidence intervals includes both central and noncentral distribution approaches.…

A spectral power analysis of driving behavior changes during the transition from nondistraction to distraction.

PubMed

Wang, Yuan; Bao, Shan; Du, Wenjun; Ye, Zhirui; Sayer, James R

2017-11-17

This article investigated and compared frequency domain and time domain characteristics of drivers' behaviors before and after the start of distracted driving. Data from an existing naturalistic driving study were used. Fast Fourier transform (FFT) was applied for the frequency domain analysis to explore drivers' behavior pattern changes between nondistracted (prestarting of visual-manual task) and distracted (poststarting of visual-manual task) driving periods. Average relative spectral power in a low frequency range (0-0.5 Hz) and the standard deviation in a 10-s time window of vehicle control variables (i.e., lane offset, yaw rate, and acceleration) were calculated and further compared. Sensitivity analyses were also applied to examine the reliability of the time and frequency domain analyses. Results of the mixed model analyses from the time and frequency domain analyses all showed significant degradation in lateral control performance after engaging in visual-manual tasks while driving. Results of the sensitivity analyses suggested that the frequency domain analysis was less sensitive to the frequency bandwidth, whereas the time domain analysis was more sensitive to the time intervals selected for variation calculations. Different time interval selections can result in significantly different standard deviation values, whereas average spectral power analysis on yaw rate in both low and high frequency bandwidths showed consistent results, that higher variation values were observed during distracted driving when compared to nondistracted driving. This study suggests that driver state detection needs to consider the behavior changes during the prestarting periods, instead of only focusing on periods with physical presence of distraction, such as cell phone use. Lateral control measures can be a better indicator of distraction detection than longitudinal controls. In addition, frequency domain analyses proved to be a more robust and consistent method in assessing driving performance compared to time domain analyses.

Effective Connectivity in Response to Posture Changes in Elderly Subjects as Assessed Using Functional Near-Infrared Spectroscopy

PubMed Central

Huo, Congcong; Zhang, Ming; Bu, Lingguo; Xu, Gongcheng; Liu, Ying; Li, Zengyong; Sun, Lingling

2018-01-01

This study aims to assess the posture-related changes in frequency-specific effective connectivity (EC) in elderly subjects by coupling function measured using functional near-infrared spectroscopy (fNIRS). The fNIRS signals were continuously recorded from the bilateral prefrontal cortex (PFC), motor cortex (MC), and occipital lobe (OL) in 17 healthy elderly and 19 healthy young subjects during sitting and standing states. EC was calculated based on Dynamic Bayesian inference in one low frequency interval I: 0.052–0.145 Hz and one very low frequency interval II: 0.021–0.052 Hz. Results show that in response to posture change, the coupling strength significantly increased in interval I of the young group from right PFC to MC (p < 0.05). Meanwhile, the coupling strength of the elderly group was significantly increased in interval II from the left PFC to right PFC (p = 0.008) and to left MC (p = 0.031) in the standing state as compared with that in the sitting state. Compared with that of the young group, the coupling strength of the elderly group was significantly decreased (p < 0.05) between the right PFC and left PFC in interval I and from PFC and OL to MC in interval II during the sitting state. The decreased EC in interval I was also positively correlated with cognitive scores in the elderly group. In addition, the coupling strength from MC to PFC in interval II during standing state was significantly increased in elderly subjects as compared with that in the young group. These results revealed the age-related changes in reorganization of interregional interactions for different postures. These findings may provide evidence of impaired cognitive function in the elderly and can deepen the understanding on age-related changes in neurovascular coupling. PMID:29615883

What is the effect of surgery on the quality of life of the adolescent with adolescent idiopathic scoliosis? A review and statistical analysis of the literature.

PubMed

Rushton, Paul R P; Grevitt, Michael P

2013-04-20

Review and statistical analysis of studies evaluating the effect of surgery on the health-related quality of life of adolescents with adolescent idiopathic scoliosis, using Scoliosis Research Society (SRS) outcomes. Apply published minimum clinical important differences (MCID) values for the SRS22r questionnaire to the literature to identify what areas of health-related quality of life are consistently affected by surgery and whether changes are clinically meaningful. The interpretation of published studies using the SRS outcomes has been limited by the lack of MCID values for the questionnaire domains. The recent publication of these data allows the clinical importance of any changes in these studies to be examined for the first time. A literature search was undertaken to locate suitable studies that were then analyzed. Statistically significant differences from baseline to 2 years postoperatively were ascertained by narratively reporting the analyses within included studies. When possible, clinically significant changes were assessed using 95% confidence intervals for the change in mean domain score. If the lower bound of the confidence intervals for the change exceeded the MCID for that domain, the change was considered clinically significant. The numbers of cohorts available for the different analyses varied (5-16). Eighty-one percent and 94% of included cohorts experienced statistically significant improvements in pain and self-image domains. In terms of clinical significance, it was only self-image that regularly improved by more than MCID, doing so in 4 of 5 included cohorts (80%) compared with 1 of 12 cohorts (8%) for pain. No clinically relevant changes occurred in mental health or activity domains. Evidence suggests that surgery can lead to clinically important improvement in patient self-image. Surgeons and patients should be aware of the limited evidence for improvements in domains other than self-image after surgery. Surgical decision-making will also be influenced by the natural history of adolescent idiopathic scoliosis.

Fixed ratio combinations of glucagon like peptide 1 receptor agonists with basal insulin: a systematic review and meta-analysis.

PubMed

Liakopoulou, Paraskevi; Liakos, Aris; Vasilakou, Despoina; Athanasiadou, Eleni; Bekiari, Eleni; Kazakos, Kyriakos; Tsapas, Apostolos

2017-06-01

Basal insulin controls primarily fasting plasma glucose but causes hypoglycaemia and weight gain, whilst glucagon like peptide 1 receptor agonists induce weight loss without increasing risk for hypoglycaemia. We conducted a systematic review and meta-analysis of randomised controlled trials to investigate the efficacy and safety of fixed ratio combinations of basal insulin with glucagon like peptide 1 receptor agonists. We searched Medline, Embase, and the Cochrane Library as well as conference abstracts up to December 2016. We assessed change in haemoglobin A 1c , body weight, and incidence of hypoglycaemia and gastrointestinal adverse events. We included eight studies with 5732 participants in the systematic review. Switch from basal insulin to fixed ratio combinations with a glucagon like peptide 1 receptor agonist was associated with 0.72% reduction in haemoglobin A 1c [95% confidence interval -1.03 to -0.41; I 2  = 93%] and 2.35 kg reduction in body weight (95% confidence interval -3.52 to -1.19; I 2  = 93%), reducing also risk for hypoglycaemia [odds ratio 0.70; 95% confidence interval 0.57 to 0.86; I 2  = 85%] but increasing incidence of nausea (odds ratio 6.89; 95% confidence interval 3.73-12.74; I 2  = 79%). Similarly, switching patients from treatment with a glucagon like peptide 1 receptor agonist to a fixed ratio combination with basal insulin was associated with 0.94% reduction in haemoglobin A 1c (95% confidence interval -1.11 to -0.77) and an increase in body weight by 2.89 kg (95% confidence interval 2.17-3.61). Fixed ratio combinations of basal insulin with glucagon like peptide 1 receptor agonists improve glycaemic control whilst balancing out risk for hypoglycaemia and gastrointestinal side effects.

Emergency Medical Services Intervals and Survival in Trauma: Assessment of the “Golden Hour” in a North American Prospective Cohort

PubMed Central

Newgard, Craig D.; Schmicker, Robert H.; Hedges, Jerris R.; Trickett, John P.; Davis, Daniel P.; Bulger, Eileen M.; Aufderheide, Tom P.; Minei, Joseph P.; Hata, J. Steven; Gubler, K. Dean; Brown, Todd B.; Yelle, Jean-Denis; Bardarson, Berit; Nichol, Graham

2010-01-01

Study objective The first hour after the onset of out-of-hospital traumatic injury is referred to as the “golden hour,” yet the relationship between time and outcome remains unclear. We evaluate the association between emergency medical services (EMS) intervals and mortality among trauma patients with field-based physiologic abnormality. Methods This was a secondary analysis of an out-of-hospital, prospective cohort registry of adult (aged ≥15 years) trauma patients transported by 146 EMS agencies to 51 Level I and II trauma hospitals in 10 sites across North America from December 1, 2005, through March 31, 2007. Inclusion criteria were systolic blood pressure less than or equal to 90 mm Hg, respiratory rate less than 10 or greater than 29 breaths/min, Glasgow Coma Scale score less than or equal to 12, or advanced airway intervention. The outcome was inhospital mortality. We evaluated EMS intervals (activation, response, on-scene, transport, and total time) with logistic regression and 2-step instrumental variable models, adjusted for field-based confounders. Results There were 3,656 trauma patients available for analysis, of whom 806 (22.0%) died. In multivariable analyses, there was no significant association between time and mortality for any EMS interval: activation (odds ratio [OR] 1.00; 95% confidence interval [CI] 0.95 to 1.05), response (OR 1.00; 95% CI 9.97 to 1.04), on-scene (OR 1.00; 95% CI 0.99 to 1.01), transport (OR 1.00; 95% CI 0.98 to 1.01), or total EMS time (OR 1.00; 95% CI 0.99 to 1.01). Subgroup and instrumental variable analyses did not qualitatively change these findings. Conclusion In this North American sample, there was no association between EMS intervals and mortality among injured patients with physiologic abnormality in the field. PMID:19783323

Auditory inhibitory gating in medial prefrontal cortex: Single unit and local field potential analysis.

PubMed

Mears, R P; Klein, A C; Cromwell, H C

2006-08-11

Medial prefrontal cortex is a crucial region involved in inhibitory processes. Damage to the medial prefrontal cortex can lead to loss of normal inhibitory control over motor, sensory, emotional and cognitive functions. The goal of the present study was to examine the basic properties of inhibitory gating in this brain region in rats. Inhibitory gating has recently been proposed as a neurophysiological assay for sensory filters in higher brain regions that potentially enable or disable information throughput. This perspective has important clinical relevance due to the findings that gating is dramatically impaired in individuals with emotional and cognitive impairments (i.e. schizophrenia). We used the standard inhibitory gating two-tone paradigm with a 500 ms interval between tones and a 10 s interval between tone pairs. We recorded both single unit and local field potentials from chronic microwire arrays implanted in the medial prefrontal cortex. We investigated short-term (within session) and long-term (between session) variability of auditory gating and additionally examined how altering the interval between the tones influenced the potency of the inhibition. The local field potentials displayed greater variability with a reduction in the amplitudes of the tone responses over both the short and long-term time windows. The decrease across sessions was most intense for the second tone response (test tone) leading to a more robust gating (lower T/C ratio). Surprisingly, single unit responses of different varieties retained similar levels of auditory responsiveness and inhibition in both the short and long-term analysis. Neural inhibition decreased monotonically related to the increase in intertone interval. This change in gating was most consistent in the local field potentials. Subsets of single unit responses did not show the lack of inhibition even for the longer intertone intervals tested (4 s interval). These findings support the idea that the medial prefrontal cortex is an important site where early inhibitory functions reside and potentially mediate psychological processes.

QT interval correction for drug-induced changes in body temperature during integrated cardiovascular safety assessment in regulatory toxicology studies in dogs: A case study.

PubMed

El Amrani, Abdel-Ilah; El Amrani-Callens, Francine; Loriot, Stéphane; Singh, Pramila; Forster, Roy

2016-01-01

Cardiovascular safety assessment requires accurate evaluation of QT interval, which depends on the length of the cardiac cycle and also on core body temperature (BT). Increases in QT interval duration have been shown to be associated with decreases in BT in dogs. An example of altered QT interval duration associated with changes in body temperature observed during a 4-week regulatory toxicology study in dogs is presented. Four groups of Beagle dogs received the vehicle or test item once on Day 1, followed by a 4-week observation period. Electrocardiogram (ECG) parameters were continuously recorded on Days 1 and 26 by jacketed external telemetry (JET). Core body temperature (BT) was measured with a conventional rectal thermometer at appropriate time-points during the Day 1 recording period. Decreased BT was observed approximately 2h after treatment on Day 1, along with increased QT interval duration corrected according to the Van de Water formula (QTcV), but the effect was no longer observed after correction for changes in BT [QTcVcT=QTcV-14(37.5-BT)] according to the Van der Linde formula. No significant changes in QTcV were reported at the end of the observation period, on Day 26. The present study demonstrates that core body (rectal) temperature can easily be monitored at appropriate time-points during JET recording in regulatory toxicology studies in dogs, in order to correct QT interval duration values for treatment-related changes in BT. The successful application of the Van der Linde formula to correct QTc prolongation for changes in BT was demonstrated. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Impact of the Norepinephrine Prodrug Droxidopa on the QTc Interval in Healthy Individuals.

PubMed

White, William B; Hewitt, L Arthur; Mehdirad, Ali A

2018-03-01

A double-blind, 4-period crossover study (NCT01327066) was conducted to assess the effect of the novel norepinephrine prodrug droxidopa on the QT interval in in healthy subjects. Subjects were randomized to receive a single dose of droxidopa 600 mg (maximal dose) and 2000 mg (supratherapeutic dose) compared with the positive control, moxifloxacin 400 mg, and placebo, each separated by a 3-day washout period. Patients were monitored by continuous Holter monitoring, and electrocardiograms (ECGs) were extracted 0.5-23 hours after dosing. Blood samples for pharmacokinetic analysis were collected before dosing and after ECG data collection. The primary end point was the time-matched placebo-adjusted change from baseline in the individually corrected QT (QTcI). The time-averaged QTcI mean placebo-corrected changes from baseline for droxidopa 600 and 2000 mg were 0.1 milliseconds (90%CI, -0.9 to 1.0 milliseconds) and 0.3 milliseconds (90%CI, -0.6 to 1.3 milliseconds), respectively, and 9 milliseconds (90%CI, 8.4-10.3 milliseconds) for moxifloxacin. This study found no effect of either dose of droxidopa on cardiac repolarization using QTcI. Analysis of the pharmacokinetic/pharmacodynamic relationship and cardiac repolarization showed no association with droxidopa exposure. There were no clinically relevant effects of droxidopa on heart rate, atrioventricular conduction, or cardiac depolarization identified. No morphologic ECG changes were observed. © 2017 The Authors. Clinical Pharmacology in Drug Development Published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

Impact of the Norepinephrine Prodrug Droxidopa on the QTc Interval in Healthy Individuals

PubMed Central

Hewitt, L. Arthur; Mehdirad, Ali A.

2017-01-01

Abstract A double‐blind, 4‐period crossover study (NCT01327066) was conducted to assess the effect of the novel norepinephrine prodrug droxidopa on the QT interval in in healthy subjects. Subjects were randomized to receive a single dose of droxidopa 600 mg (maximal dose) and 2000 mg (supratherapeutic dose) compared with the positive control, moxifloxacin 400 mg, and placebo, each separated by a 3‐day washout period. Patients were monitored by continuous Holter monitoring, and electrocardiograms (ECGs) were extracted 0.5–23 hours after dosing. Blood samples for pharmacokinetic analysis were collected before dosing and after ECG data collection. The primary end point was the time‐matched placebo‐adjusted change from baseline in the individually corrected QT (QTcI). The time‐averaged QTcI mean placebo‐corrected changes from baseline for droxidopa 600 and 2000 mg were 0.1 milliseconds (90%CI, ‐0.9 to 1.0 milliseconds) and 0.3 milliseconds (90%CI, ‐0.6 to 1.3 milliseconds), respectively, and 9 milliseconds (90%CI, 8.4–10.3 milliseconds) for moxifloxacin. This study found no effect of either dose of droxidopa on cardiac repolarization using QTcI. Analysis of the pharmacokinetic/pharmacodynamic relationship and cardiac repolarization showed no association with droxidopa exposure. There were no clinically relevant effects of droxidopa on heart rate, atrioventricular conduction, or cardiac depolarization identified. No morphologic ECG changes were observed. PMID:29024579

Rasch analysis of the Edmonton Symptom Assessment System and research implications

PubMed Central

Cheifetz, O.; Packham, T.L.; MacDermid, J.C.

2014-01-01

Background Reliable and valid assessment of the disease burden across all forms of cancer is critical to the evaluation of treatment effectiveness and patient progress. The Edmonton Symptom Assessment System (esas) is used for routine evaluation of people attending for cancer care. In the present study, we used Rasch analysis to explore the measurement properties of the esas and to determine the effect of using Rasch-proposed interval-level esas scoring compared with traditional scoring when evaluating the effects of an exercise program for cancer survivors. Methods Polytomous Rasch analysis (Andrich’s rating-scale model) was applied to data from 26,645 esas questionnaires completed at the Juravinski Cancer Centre. The fit of the esas to the polytomous Rasch model was investigated, including evaluations of differential item functioning for sex, age, and disease group. The research implication was investigated by comparing the results of an observational research study previously analysed using a traditional approach with the results obtained by Rasch-proposed interval-level esas scoring. Results The Rasch reliability index was 0.73, falling short of the desired 0.80–0.90 level. However, the esas was found to fit the Rasch model, including the criteria for uni-dimensional data. The analysis suggests that the current esas scoring system of 0–10 could be collapsed to a 6-point scale. Use of the Rasch-proposed interval-level scoring yielded results that were different from those calculated using summarized ordinal-level esas scores. Differential item functioning was not found for sex, age, or diagnosis groups. Conclusions The esas is a moderately reliable uni-dimensional measure of cancer disease burden and can provide interval-level scaling with Rasch-based scoring. Further, our study indicates that, compared with the traditional scoring metric, Rasch-based scoring could result in substantive changes to conclusions. PMID:24764703

Interval sentinel lymph nodes in melanoma: a digital pathology analysis of Ki67 expression and microvascular density.

PubMed

Marinaccio, Christian; Giudice, Giuseppe; Nacchiero, Eleonora; Robusto, Fabio; Opinto, Giuseppina; Lastilla, Gaetano; Maiorano, Eugenio; Ribatti, Domenico

2016-08-01

The presence of interval sentinel lymph nodes in melanoma is documented in several studies, but controversies still exist about the management of these lymph nodes. In this study, an immunohistochemical evaluation of tumor cell proliferation and neo-angiogenesis has been performed with the aim of establishing a correlation between these two parameters between positive and negative interval sentinel lymph nodes. This retrospective study reviewed data of 23 patients diagnosed with melanoma. Bioptic specimens of interval sentinel lymph node were retrieved, and immunohistochemical reactions on tissue sections were performed using Ki67 as a marker of proliferation and CD31 as a blood vessel marker for the study of angiogenesis. The entire stained tissue sections for each case were digitized using Aperio Scanscope Cs whole-slide scanning platform and stored as high-resolution images. Image analysis was carried out on three selected fields of equal area using IHC Nuclear and Microvessel analysis algorithms to determine positive Ki67 nuclei and vessel number. Patients were divided into positive and negative interval sentinel lymph node groups, and the positive interval sentinel lymph node group was further divided into interval positive with micrometastasis and interval positive with macrometastasis subgroups. The analysis revealed a significant difference between positive and negative interval sentinel lymph nodes in the percentage of Ki67-positive nuclei and mean vessel number suggestive of an increased cellular proliferation and angiogenesis in positive interval sentinel lymph nodes. Further analysis in the interval positive lymph node group showed a significant difference between micro- and macrometastasis subgroups in the percentage of Ki67-positive nuclei and mean vessel number. Percentage of Ki67-positive nuclei was increased in the macrometastasis subgroup, while mean vessel number was increased in the micrometastasis subgroup. The results of this study suggest that the correlation between tumor cell proliferation and neo-angiogenesis in interval sentinel lymph nodes in melanoma could be used as a good predictive marker to distinguish interval positive sentinel lymph nodes with micrometastasis from interval positive lymph nodes with macrometastasis subgroups.

[Comparative analysis of the donor cornea quality and of the interval between death and preservation before and after new sanitary and technique rules in a University Eye Bank].

PubMed

Zantut, Fabio; Holzchuh, Ricardo; Boni, Reginaldo Carlos; Mackus, Eva Cristina; Zantut, Paulo Roberto; Nakano, Claudio; Netto, Adamo Lui; Hida, Richard Yudi

2012-01-01

To compare the interval between death and enucleation (ΔT-O-E), between enucleation and preservation (ΔT-E-P) and the quality of the cornea before and after the implantation of new technique and sanitary rules. A retrospective study that evaluated the records of cornea donors in Sao Paulo's Santa Casa Eye Tissue Bank 2 years before and 2 years after the implementation new sanitary rules. An increase was observed in the absolute number of 205 to 374 donors following the adopted changes. There was no statistically significant difference in Δt-O-E and ΔT-E-P before and after the implemented changes. Of the total of 1,105 donor corneas, 388 donor corneas were observed before the changes and 717 donor corneas after the implemented changes. We observed a statistically significant increase in grading of donor cornea quality from 1.76 ± 0.90 to 1.94 ± 0.88 after the implementation of new standards of resolution. After the changes required by Resolution 347, there was a large increase in the number of donated, taken and preserved corneas. The BTO has not diminished the ΔT O-E and ΔT E-P. Cornea quality presented itself lower after the new rules.

Evaluation of Operational Procedures for Using a Time-Based Airborne Inter-arrival Spacing Tool

NASA Technical Reports Server (NTRS)

Oseguera-Lohr, Rosa M.; Lohr, Gary W.; Abbott, Terence S.; Eischeid, Todd M.

2002-01-01

An airborne tool has been developed based on the concept of an aircraft maintaining a time-based spacing interval from the preceding aircraft. The Advanced Terminal Area Approach Spacing (ATAAS) tool uses Automatic Dependent Surveillance-Broadcast (ADS-B) aircraft state data to compute a speed command for the ATAAS-equipped aircraft to obtain a required time interval behind another aircraft. The tool and candidate operational procedures were tested in a high-fidelity, full mission simulator with active airline subject pilots flying an arrival scenario using three different modes for speed control. The objectives of this study were to validate the results of a prior Monte Carlo analysis of the ATAAS algorithm and to evaluate the concept from the standpoint of pilot acceptability and workload. Results showed that the aircraft was able to consistently achieve the target spacing interval within one second (the equivalent of approximately 220 ft at a final approach speed of 130 kt) when the ATAAS speed guidance was autothrottle-coupled, and a slightly greater (4-5 seconds), but consistent interval with the pilot-controlled speed modes. The subject pilots generally rated the workload level with the ATAAS procedure as similar to that with standard procedures, and also rated most aspects of the procedure high in terms of acceptability. Although pilots indicated that the head-down time was higher with ATAAS, the acceptability of head-down time was rated high. Oculometer data indicated slight changes in instrument scan patterns, but no significant change in the amount of time spent looking out the window between the ATAAS procedure versus standard procedures.

Effects of interval exercise training programme on the indices of adiposity and biomarker of inflammation in hypertension: a randomised controlled trial.

PubMed

Lamina, S; Okoye, C G; Hanif, S M

2014-06-01

Hypertension remains a significant risk factor in cardiovascular morbidity and mortality. The purpose of the present study was to investigate the effects of 8 weeks interval training programme on blood pressure, aerobic capacity (VO max), indices of adiposity and marker of inflammation in black African men with essential hypertension. Two hundred and forty five (245) male subjects with stage 1 and 2 (systolic blood pressure [SBP] between 140-179 & diastolic blood pressure [DBP] between 90-109 mmHg) essential hypertension were age matched and grouped into experimental and control groups. The experimental (n=140; 58.90 ± 7.35 years) group involved in an 8 weeks interval training (60-79% HRmax) programme of between 45 and 60 minutes, while age-matched control hypertensive (n=105; 58.27±6.24 years) group remain sedentary during this period. All subjects in both groups were on antihypertensive drugs throughout the study period. Cardiovascular parameters (SBP, DBP) & VO max and percent body fat [%BF], waist to hip ratio [WHR] and C-reactive protein [CRP] were assessed. Independent t-test and Pearson correlation test were used in data analysis. Findings of the study revealed significant decreased effects of interval training programme on SBP, DBP, %BF, WHR and CRP and significant increased effect on VO max at p< 0.05. Also, changes in CRP as a result of exercise training significantly and positively correlated with changes in SBP, DBP, %BF, WHR, CRP and negatively correlated with VO max at p< 0.05.

Auditory evoked responses to binaural beat illusion: stimulus generation and the derivation of the Binaural Interaction Component (BIC).

PubMed

Ozdamar, Ozcan; Bohorquez, Jorge; Mihajloski, Todor; Yavuz, Erdem; Lachowska, Magdalena

2011-01-01

Electrophysiological indices of auditory binaural beats illusions are studied using late latency evoked responses. Binaural beats are generated by continuous monaural FM tones with slightly different ascending and descending frequencies lasting about 25 ms presented at 1 sec intervals. Frequency changes are carefully adjusted to avoid any creation of abrupt waveform changes. Binaural Interaction Component (BIC) analysis is used to separate the neural responses due to binaural involvement. The results show that the transient auditory evoked responses can be obtained from the auditory illusion of binaural beats.

A systematic review and meta-analysis of interventions for weight management using text messaging.

PubMed

Siopis, G; Chey, T; Allman-Farinelli, M

2015-02-01

Obesity prevalence continues to increase worldwide, with significant associated chronic disease and health cost implications. Among more recent innovations in health service provision is the use of text messaging for health behaviour change interventions including weight management. This review investigates the efficacy of weight management programmes incorporating text messaging. Medical and scientific databases were searched from January 1993 to October 2013. Eligibility criteria included randomised controlled trials (RCTs), pseudoRCTs and before and after studies of weight management, among healthy children and adults, that used text messaging and included a nutrition component. Data extraction and quality assessment followed guidelines from PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) and the Evidence Analysis Manual of the American Academy of Nutrition and Dietetics. From 512 manuscripts retrieved, 14 met the inclusion criteria (five manuscripts in children and nine in adults). Duration of interventions ranged from 1 to 24 months. Frequency of text messaging was from daily to fortnightly. Six studies in adults were included in a meta-analysis with mean body weight change as the primary outcome. The weighted mean change in body weight in intervention participants was -2.56 kg (95% confidence interval = -3.46 to -1.65) and in controls -0.37 kg (95% confidence interval = -1.22 to 0.48). The small body of evidence indicates that text messaging interventions can promote weight loss. However, lack of long-term results indicate that further efficacy studies are required. Future investigations should elucidate the determinants, such as intervention duration, text message frequency and level of interactivity that maximise the success and cost effectiveness of the delivery medium. © 2014 The British Dietetic Association Ltd.

Evaluation of Visual Field and Imaging Outcomes for Glaucoma Clinical Trials (An American Ophthalomological Society Thesis).

PubMed

Garway-Heath, David F; Quartilho, Ana; Prah, Philip; Crabb, David P; Cheng, Qian; Zhu, Haogang

2017-08-01

To evaluate the ability of various visual field (VF) analysis methods to discriminate treatment groups in glaucoma clinical trials and establish the value of time-domain optical coherence tomography (TD OCT) imaging as an additional outcome. VFs and retinal nerve fibre layer thickness (RNFLT) measurements (acquired by TD OCT) from 373 glaucoma patients in the UK Glaucoma Treatment Study (UKGTS) at up to 11 scheduled visits over a 2 year interval formed the cohort to assess the sensitivity of progression analysis methods. Specificity was assessed in 78 glaucoma patients with up to 11 repeated VF and OCT RNFLT measurements over a 3 month interval. Growth curve models assessed the difference in VF and RNFLT rate of change between treatment groups. Incident progression was identified by 3 VF-based methods: Guided Progression Analysis (GPA), 'ANSWERS' and 'PoPLR', and one based on VFs and RNFLT: 'sANSWERS'. Sensitivity, specificity and discrimination between treatment groups were evaluated. The rate of VF change was significantly faster in the placebo, compared to active treatment, group (-0.29 vs +0.03 dB/year, P <.001); the rate of RNFLT change was not different (-1.7 vs -1.1 dB/year, P =.14). After 18 months and at 95% specificity, the sensitivity of ANSWERS and PoPLR was similar (35%); sANSWERS achieved a sensitivity of 70%. GPA, ANSWERS and PoPLR discriminated treatment groups with similar statistical significance; sANSWERS did not discriminate treatment groups. Although the VF progression-detection method including VF and RNFLT measurements is more sensitive, it does not improve discrimination between treatment arms.

State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students.

PubMed

Dimitriev, Dimitriy A; Saperova, Elena V; Dimitriev, Aleksey D

2016-01-01

Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger's State-Trait Anxiety Inventory was used to assess the level of SA. Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation.

The effect of short duration transportation on serum cortisol response in alpacas (Llama pacos).

PubMed

Anderson, D E; Grubb, T; Silveira, F

1999-03-01

This research project evaluated the changes in serum cortisol in six male and six female alpacas in response to transportation of short duration. All alpacas were subjected to trailer transportation for 30 min. Serum samples were obtained prior to transportation, immediately after transportation, and after a 4-h recovery period. Heart rate was recorded at each time interval and observations of individual behavioural characteristics were recorded. Data were analysed using analysis of variance. Heart rate was not significantly changed by transportation stress. Serum cortisol concentration was significantly higher after transportation, but head returned to baseline concentration after the 4-h recovery period. Behavioural characteristics were not associated with changes in serum cortisol concentration.

Changes in intensity of precipitation extremes in Romania on very hight temporal scale and implications on the validity of the Clausius-Clapeyron relation

NASA Astrophysics Data System (ADS)

Busuioc, Aristita; Baciu, Madalina; Breza, Traian; Dumitrescu, Alexandru; Stoica, Cerasela; Baghina, Nina

2016-04-01

Many observational, theoretical and based on climate model simulation studies suggested that warmer climates lead to more intense precipitation events, even when the total annual precipitation is slightly reduced. In this way, it was suggested that extreme precipitation events may increase at Clausius-Clapeyron (CC) rate under global warming and constraint of constant relative humidity. However, recent studies show that the relationship between extreme rainfall intensity and atmospheric temperature is much more complex than would be suggested by the CC relationship and is mainly dependent on precipitation temporal resolution, region, storm type and whether the analysis is conducted on storm events rather than fixed data. The present study presents the dependence between the very hight temporal scale extreme rainfall intensity and daily temperatures, with respect to the verification of the CC relation. To solve this objective, the analysis is conducted on rainfall event rather than fixed interval using the rainfall data based on graphic records including intensities (mm/min.) calculated over each interval with permanent intensity per minute. The annual interval with available a such data (April to October) is considered at 5 stations over the interval 1950-2007. For Bucuresti-Filaret station the analysis is extended over the longer interval (1898-2007). For each rainfall event, the maximum intensity (mm/min.) is retained and these time series are considered for the further analysis (abbreviated in the following as IMAX). The IMAX data were divided based on the daily mean temperature into bins 2oC - wide. The bins with less than 100 values were excluded. The 90th, 99th and 99.9th percentiles were computed from the binned data using the empirical distribution and their variability has been compared to the CC scaling (e.g. exponential relation given by a 7% increase per temperature degree rise). The results show a dependence close to double the CC relation for temperatures less than ~ 220C and negative scaling rates for higher temperatures. This behaviour is similar for all the 5 analysed stations over the common interval 1950-2007. This scaling is more exactly for the 90th percentile, while for the higher percentiles the rainfall intensity in response to warming exceeds sometimes the CC rate. For Bucuresti-Filaret station, the results are similar over a longer interval (1898-2007) showing that these findings are robust. Similar techniques has been previously applied to the hourly rainfall intensities recorded at 9 stations (including the 5 ones) and the results are slightly different: the 90th percentile shows dependence close to the CC relation for all temperatures; the 99th and 99.9th percentiles exhibit rates close to double the CC rate for temperatures between ~ 100C and ~ 220C and negative scaling rates for higher temperatures. In conclusion, these results show that the dependence between the extreme precipitation intensity and atmospheric temperature in Romania is mainly dependent on the temporal precipitation resolution and the degree of the extreme precipitation event (moderate or stronger); these findings are mainly in agreenment with the conclusions presented by previous international studies (mentioned above), with some regional specific features, showing the importance of the regional studies. The results presented is this study were funded by the Executive Agency for Higher Education, Research, Development and Innovation Funding (UEFISCDI) through the research project CLIMHYDEX, "Changes in climate extremes and associated impact in hydrological events in Romania", code PNII-ID-2011-2-0073 (http://climhydex.meteoromania.ro).

Towards a personalized and dynamic CRT-D. A computational cardiovascular model dedicated to therapy optimization.

PubMed

Di Molfetta, A; Santini, L; Forleo, G B; Minni, V; Mafhouz, K; Della Rocca, D G; Fresiello, L; Romeo, F; Ferrari, G

2012-01-01

In spite of cardiac resynchronization therapy (CRT) benefits, 25-30% of patients are still non responders. One of the possible reasons could be the non optimal atrioventricular (AV) and interventricular (VV) intervals settings. Our aim was to exploit a numerical model of cardiovascular system for AV and VV intervals optimization in CRT. A numerical model of the cardiovascular system CRT-dedicated was previously developed. Echocardiographic parameters, Systemic aortic pressure and ECG were collected in 20 consecutive patients before and after CRT. Patient data were simulated by the model that was used to optimize and set into the device the intervals at the baseline and at the follow up. The optimal AV and VV intervals were chosen to optimize the simulated selected variable/s on the base of both echocardiographic and electrocardiographic parameters. Intervals were different for each patient and in most cases, they changed at follow up. The model can well reproduce clinical data as verified with Bland Altman analysis and T-test (p > 0.05). Left ventricular remodeling was 38.7% and left ventricular ejection fraction increasing was 11% against the 15% and 6% reported in literature, respectively. The developed numerical model could reproduce patients conditions at the baseline and at the follow up including the CRT effects. The model could be used to optimize AV and VV intervals at the baseline and at the follow up realizing a personalized and dynamic CRT. A patient tailored CRT could improve patients outcome in comparison to literature data.

Effects of a prior stretching of the plantarflexor muscles on the capacity to control upright stance maintenance in healthy adults.

PubMed

Rougier, Patrice; Burdet, Cyril; Genthon, Nicolas

2006-10-01

To assess whether prior stretching of a muscle can induce improved postural control, 15 healthy adults stood still upright with their eyes closed before and after a series of bilateral stretches of the triceps surae muscles. The analysis focused on the center of pressure (CP) and the vertical projection of the center of gravity (CGv) trajectories and their difference (CP - CGv). The prolonged stretching induced a forward shift of the mean position of the CGv. The frequency analysis showed a constancy of the amplitudes of both basic movements whereas an increased mean power frequency was seen for the CP - CGv movements. A fractional Brownian motion modeling of the trajectories indicates shortest time intervals and lower covered distances by the CGv before a change in its control occurs along the antero-posterior axis. This reorganization is thought to be a result of improved body movement detection, which allows postural control over the longest time intervals to be triggered more rapidly.

Automatic Error Analysis Using Intervals

ERIC Educational Resources Information Center

Rothwell, E. J.; Cloud, M. J.

2012-01-01

A technique for automatic error analysis using interval mathematics is introduced. A comparison to standard error propagation methods shows that in cases involving complicated formulas, the interval approach gives comparable error estimates with much less effort. Several examples are considered, and numerical errors are computed using the INTLAB…

Cardiopulmonary resuscitation quality: Widespread variation in data intervals used for analysis.

PubMed

Talikowska, Milena; Tohira, Hideo; Bailey, Paul; Finn, Judith

2016-05-01

There is a growing body of evidence for the relationship between CPR quality and survival in cardiac arrest patients. We sought to describe the characteristics of the analysis intervals used across studies. Relevant papers were selected as described in our recent systematic review. From these papers we collected information about (1) the time interval used for analysis; (2) the event that marked the beginning of the analysis interval; and (3) the minimum amount of CPR quality data required for a case to be included in the analysed cohort. We then compared this data across papers. Twenty-one studies reported on the association between CPR quality and cardiac arrest patient survival. In two thirds of studies data from the start of the resuscitation episode was analysed, in particular the first 5min. Commencement of the analysis interval was marked by various events including ECG pad placement and first chest compression. Nine studies specified a minimum amount of data that had to have been collected for the individual case to be included in the analysis; most commonly 1min of data. The use of shorter intervals allowed for inclusion of more cases as it included cases that did not have a complete dataset. To facilitate comparisons across studies, a standardised definition of the data analysis interval should be developed; one that maximises the amount of cases available without compromising the data's representability of the resuscitation effort. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The association between exaggeration in health related science news and academic press releases: retrospective observational study

PubMed Central

Vivian-Griffiths, Solveiga; Boivin, Jacky; Williams, Andy; Venetis, Christos A; Davies, Aimée; Ogden, Jack; Whelan, Leanne; Hughes, Bethan; Dalton, Bethan; Boy, Fred

2014-01-01

Objective To identify the source (press releases or news) of distortions, exaggerations, or changes to the main conclusions drawn from research that could potentially influence a reader’s health related behaviour. Design Retrospective quantitative content analysis. Setting Journal articles, press releases, and related news, with accompanying simulations. Sample Press releases (n=462) on biomedical and health related science issued by 20 leading UK universities in 2011, alongside their associated peer reviewed research papers and news stories (n=668). Main outcome measures Advice to readers to change behaviour, causal statements drawn from correlational research, and inference to humans from animal research that went beyond those in the associated peer reviewed papers. Results 40% (95% confidence interval 33% to 46%) of the press releases contained exaggerated advice, 33% (26% to 40%) contained exaggerated causal claims, and 36% (28% to 46%) contained exaggerated inference to humans from animal research. When press releases contained such exaggeration, 58% (95% confidence interval 48% to 68%), 81% (70% to 93%), and 86% (77% to 95%) of news stories, respectively, contained similar exaggeration, compared with exaggeration rates of 17% (10% to 24%), 18% (9% to 27%), and 10% (0% to 19%) in news when the press releases were not exaggerated. Odds ratios for each category of analysis were 6.5 (95% confidence interval 3.5 to 12), 20 (7.6 to 51), and 56 (15 to 211). At the same time, there was little evidence that exaggeration in press releases increased the uptake of news. Conclusions Exaggeration in news is strongly associated with exaggeration in press releases. Improving the accuracy of academic press releases could represent a key opportunity for reducing misleading health related news. PMID:25498121

Scaling Analysis of Tide Gauge Data from the Atlantic, Gulf of Mexico, and Pacific Coasts of the United States

NASA Astrophysics Data System (ADS)

Barton, C. C.; Smigelski, J. R.; Tebbens, S. F.

2008-12-01

Most coastal regions are subject to inundation due to many periodic and non-periodic inputs including for example: diurnal and semi diurnal tides, storms, tsunamis, and global sea level change. Tide guage data provide a frequently sampled long term record of fluctuations in water level. A power-spectral-density analysis of tidal gauge data is used to quantify persistence (degree of internal correlation over various time intervals) in terms of the scaling exponent β and to identify temporal changes in persistence. The stations are located at different proximity to the open ocean, including bays, harbors, and channels. The datasets are from the NOAA CO-OPS Verified Hourly Station Datum. The length of the data sets ranges from 3 years to 101 years. The hourly data sets are decimated to one record every four hours. All data sets analyzed show three distinct regions of persistence with two inflection points at approximately one day and five days. For times less than one day, the scaling exponent ranges between 0 < β < 2.6. For the time interval 1 to 5 days, the scaling exponent ranges between 1.1 < β < 2.1. For times greater than 5 days, the scaling exponent ranges between 0.4 < β < 0.9. Persistence generally decreases as period increases but is stable between the inflection points. At Duck, NC, long term persistence in the tide gauge signal is 0.6 as compared to 0.9 for the biweekly shoreline position signal over twenty years, suggesting a strong correlation between the two and the possibility of using tide gauge data to quantify nearby shoreline mobility over similar time intervals.

Primary-Care Weight-Management Strategies: Parental Priorities and Preferences

PubMed Central

Turer, Christy Boling; Upperman, Carla; Merchant, Zahra; Montaño, Sergio; Flores, Glenn

2015-01-01

Objective Examine parental perspectives/rankings of the most important weight-management clinical practices; and, determine whether preferences/rankings differ when parents disagree that their child is overweight. Methods Mixed-methods analysis of a 32-question survey of parents of 2-18 year-old overweight children assessing parental agreement that their child is overweight, the single most important thing providers can do to improve weight status, ranking AAP-recommended clinical practices, and preferred follow-up interval. Four independent reviewers analyzed open-response data to identify qualitative themes/subthemes. Multivariable analyses examined parental rankings, preferred follow-up interval, and differences by agreement with their child’s overweight assessment. Results Thirty-six percent of 219 children were overweight, 42% were obese, and 22% severely obese; 16% of parents disagreed with their child’s overweight assessment. Qualitative analysis of the most important practice to help overweight children yielded 10 themes; unique to parents disagreeing with their children’s overweight assessments was, “change weight-status assessments.” After adjustment, the three highest-ranked clinical practices included, “check for weight-related problems,” “review growth chart,” and “recommend general dietary changes” (all P<.01);” parents disagreeing with their children’s overweight assessments ranked “review growth chart” as less important, and “reducing screen time” and “general activity changes” as more important. The mean preferred weight-management follow-up interval (10-12 weeks) did not differ by agreement with children’s overweight assessments. Conclusions Parents prefer weight-management strategies that prioritize evaluating weight-related problems, growth-chart review, and regular follow-up. Parents who disagree that their child is overweight want changes in how overweight is assessed. Using parent-preferred weight-management strategies may prove useful in improving child weight status. PMID:26514648

The association between exaggeration in health related science news and academic press releases: retrospective observational study.

PubMed

Sumner, Petroc; Vivian-Griffiths, Solveiga; Boivin, Jacky; Williams, Andy; Venetis, Christos A; Davies, Aimée; Ogden, Jack; Whelan, Leanne; Hughes, Bethan; Dalton, Bethan; Boy, Fred; Chambers, Christopher D

2014-12-09

To identify the source (press releases or news) of distortions, exaggerations, or changes to the main conclusions drawn from research that could potentially influence a reader's health related behaviour. Retrospective quantitative content analysis. Journal articles, press releases, and related news, with accompanying simulations. Press releases (n = 462) on biomedical and health related science issued by 20 leading UK universities in 2011, alongside their associated peer reviewed research papers and news stories (n = 668). Advice to readers to change behaviour, causal statements drawn from correlational research, and inference to humans from animal research that went beyond those in the associated peer reviewed papers. 40% (95% confidence interval 33% to 46%) of the press releases contained exaggerated advice, 33% (26% to 40%) contained exaggerated causal claims, and 36% (28% to 46%) contained exaggerated inference to humans from animal research. When press releases contained such exaggeration, 58% (95% confidence interval 48% to 68%), 81% (70% to 93%), and 86% (77% to 95%) of news stories, respectively, contained similar exaggeration, compared with exaggeration rates of 17% (10% to 24%), 18% (9% to 27%), and 10% (0% to 19%) in news when the press releases were not exaggerated. Odds ratios for each category of analysis were 6.5 (95% confidence interval 3.5 to 12), 20 (7.6 to 51), and 56 (15 to 211). At the same time, there was little evidence that exaggeration in press releases increased the uptake of news. Exaggeration in news is strongly associated with exaggeration in press releases. Improving the accuracy of academic press releases could represent a key opportunity for reducing misleading health related news. © Sumner et al 2014.

Analysis of bioelectric records and fabrication of phototype sleep analysis equipment

NASA Technical Reports Server (NTRS)

Kellaway, P.

1972-01-01

A computer-analysis technique was used to evaluate the changes in the waking EEGs of 5 normal subjects which occurred during the oral administration of flurazepam hydrochloride (Dalmane). While the subjects were receiving the drug, there was an increase in the amount of beta (14-38 c/sec) activity in fronto-central EEG leads in all 5 subjects. This increase in beta activity was characterized by a highly consistent increase in the number of waves that occurred during an EEG recording interval of fixed duration and by a less consistent increase in average wave amplitude. There was no detectable change in mean EEG wavelength (frequency) within the beta frequency range. The EEG patterns reverted to their baseline condition during 2-3 weeks after withdrawal of the drug. Analysis of the alpha, theta and delta components of the EEG indicated no changes during or following administration of the drug. This study clearly illustrates the usefulness of specific computer-analysis techniques in the characterization and quantification of sleep-promoting drugs upon the EEG of the normal young adults in the waking state. Two preamplifiers and 150 EEG monitoring caps with electrodes were delivered to MSC.

Time-Series Analysis: Assessing the Effects of Multiple Educational Interventions in a Small-Enrollment Course

NASA Astrophysics Data System (ADS)

Warren, Aaron R.

2009-11-01

Time-series designs are an alternative to pretest-posttest methods that are able to identify and measure the impacts of multiple educational interventions, even for small student populations. Here, we use an instrument employing standard multiple-choice conceptual questions to collect data from students at regular intervals. The questions are modified by asking students to distribute 100 Confidence Points among the options in order to indicate the perceived likelihood of each answer option being the correct one. Tracking the class-averaged ratings for each option produces a set of time-series. ARIMA (autoregressive integrated moving average) analysis is then used to test for, and measure, changes in each series. In particular, it is possible to discern which educational interventions produce significant changes in class performance. Cluster analysis can also identify groups of students whose ratings evolve in similar ways. A brief overview of our methods and an example are presented.

Association of low-moderate urine arsenic and QT interval: Cross-sectional and longitudinal evidence from the Strong Heart Study.

PubMed

Moon, Katherine A; Zhang, Yiyi; Guallar, Eliseo; Francesconi, Kevin A; Goessler, Walter; Umans, Jason G; Best, Lyle G; Howard, Barbara V; Devereux, Richard B; Okin, Peter M; Navas-Acien, Ana

2018-05-21

Epidemiologic studies suggest that chronic exposure to arsenic is related to cardiovascular disease (CVD), but the pathophysiological link remains uncertain. We evaluated the association of chronic low-moderate arsenic exposure and arsenic metabolism with baseline difference and annual change in ECG measures (QT interval, JT interval, PR interval, QRS duration, and QT dispersion) using linear mixed models in the Strong Heart Study main cohort (N = 1174, median age 55 years) and family study (N = 1695 diabetes-free, median age 36 years). At baseline, arsenic exposure was measured as the sum of inorganic and methylated species in urine (ΣAs) and arsenic metabolism was measured as the relative percentage of arsenic species. Median ΣAs and Bazett heart rate-corrected QT interval (QTc) were 8.6 μg/g creatinine and 424 ms in the main cohort and 4.3 μg/g and 414 ms in the family study, respectively. In the main cohort, a comparison of the highest to lowest ΣAs quartile (>14.4 vs. <5.2 μg/g creatinine) was associated with a 5.3 (95% CI: 1.2, 9.5) ms higher mean baseline QTc interval but no difference in annual change in QTc interval. In the family study, a comparison of the highest to lowest quartile (>7.1 vs. <2.9 μg/g creatinine) was associated with a 3.2 (95% CI: 0.6, 5.7) ms higher baseline QTc interval and a 0.6 (95% CI: 0.04, 1.2) ms larger annual increase in QTc interval. Associations with JTc interval were similar but stronger in magnitude compared to QTc interval. Arsenic exposure was largely not associated with PR interval, QRS duration or QT dispersion. Similar to arsenic exposure, a pattern of lower %MMA and higher %DMA was associated with longer baseline QTc interval in both cohorts and with a larger annual change in QTc interval in the family study. Chronic low-moderate arsenic exposure and arsenic metabolism were associated with prolonged ventricular repolarization. Copyright © 2018 Elsevier Ltd. All rights reserved.

Climatic change and evaporative processes in the development of Common Era hypersaline lakes, East Antarctica: A study of Lake Suribati

NASA Astrophysics Data System (ADS)

Nakashima, H.; Seto, K.; Katsuki, K.; Kaneko, H.; yamada, K.; Imura, S.; Dettman, D. L.

2011-12-01

The Antarctic continent was uplifted by glacioisostatic rebound due to the regression of ice sheets after the last glacial period. Today's saline lakes were formed in shallow basins originally below sea level. Antarctic hypersaline lakes are formed by concentration of isolated seawater bodies as affected by recent climate change. Many saline lakes are found in the ice-free area of the Soya coast, East Antarctica. Lake Suribati is located in Sukarvsnes on the Soya coast. It is a hypersaline lake with maximum salinity ~200 psu, and an observable stable halocline at 7~12m depth. This study uses Lake Suribati sediment core Sr4C-01, collected by the 46th Japanese Antarctica Research Expedition, to examine the relationship of climatic change to evaporative processes and solute concentration in Lake Suribati in the Common Era. Sr4C-01 core was collected at 9.53m water depth in Lake Suribati in 2005 (core length is 63cm). This core primarily consists of black mud and laminated black organic mud. In the interval from 10 to 24cm below the sediment surface evaporite crystals occur. The age of the Sr4C-01 core bottom is estimated to be ~3,500 cal yrs BP, based on AMS carbon-14 dating at 6 core horizons. The evaporite crystals were indentified as aragonite based on XRD. Total inorganic carbon (TIC) content is low, around 0.5%, throughout the Sr4C-01 core, with higher values, approximately 1~4%, in two intervals, 57~52cm and 29~10cm core depth. Variation in CaO content tracks TIC content. We suggest that synchronous change in CaO and TIC contents indicate the vertical change in the amount of aragonite. Two intervals of evaporite precipition imply two intervals of evaporation and concentration of lake water. Hypersaline lake conditions did not occur soon after the isolation from the sea, rather these occurred under repeated concentration and dilution of lake water. Dilution of saline lake water could occur through the inflow of melt water from local snow or ice, indicating a warm climate interval. During cool periods, local snow and ice sheet may have remained frozen. In this case, lake water volume would decrease by sublimation from the frozen lake surface, leading to salt concentration. Based on MgO and Na2O content data, we suggest that other Mg and Na evaporites occur in the core. If such evaporates can be identified, a detailed solute concentration process can be described. Analysis of evaporites in sediment core from Antarctic hypersaline lakes have great potential as proxy indicators for the study of climate change in Antarctica.

Qualitative Process Theory.

DTIC Science & Technology

1984-07-01

somewhere between 70 and 80 * degrees farenheit . Changing the "value" of its temperature to [70.0 85.01 doesn’t change our description of what’s happening...interval lies between them (i.e., in this representation, time is not dense). Instants are represented as "very short" intervals which have zero ...than the time of its start, so that the duration of an instant will be zero while the duration of an interval will be greater than zero . Finally, we

Efficacy of a Single Dose of Basic Fibroblast Growth Factor: Clinical Observation for 1 Year.

PubMed

Suzuki, Hirotaka; Makiyama, Kiyoshi; Hirai, Ryoji; Matsuzaki, Hiroumi; Furusaka, Toru; Oshima, Takeshi

2016-11-01

Basic fibroblast growth factor promotes wound healing by accelerating healthy granulation and epithelialization. However, the duration of the effects of a single intracordal injection of basic fibroblast growth factor has not been established, and administration intervals and timing have yet to be standardized. Here, we administered a single injection to patients with insufficient glottic closure and conducted follow-up examinations with high-speed digital imaging to determine the duration of the treatment response. Case series. For treatment, 20 µg/mL recombinant human basic fibroblast growth factor was injected into two vocal cords. The following examinations were performed before the procedure and at 3-month intervals for 12 months starting at 1 month postinjection: Grade, Roughness, Breathiness, Asthenia, and Strain (GRBAS) scale assessment, maximum phonation time, acoustic analysis, high-speed digital imaging, glottal wave analysis, and kymographic analysis. Postinjection, the GRBAS scale score decreased, and the maximum phonation time was prolonged. In addition, the mean minimum glottal area and mean minimum glottal distance decreased. These changes were significant at 12 months postinjection compared with preinjection. However, there were no significant changes in the vibrations of the vocal cord margins. The intracordal injection of basic fibroblast growth factor improved insufficient glottic closure without reducing the vibrations of the vocal cord margins. This effect remained evident at 12 months postinjection. A single injection can be expected to yield a sufficient and persistent long-term effect. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Identification of a Group's Physiological Synchronization with Earth's Magnetic Field.

PubMed

Timofejeva, Inga; McCraty, Rollin; Atkinson, Mike; Joffe, Roza; Vainoras, Alfonsas; Alabdulgader, Abdullah A; Ragulskis, Minvydas

2017-09-01

A new analysis technique for the evaluation of the degree of synchronization between the physiological state of a group of people and changes in the Earth's magnetic field based on their cardiac inter-beat intervals was developed and validated. The new analysis method was then used to identify clusters of similar synchronization patterns in a group of 20 individuals over a two-week period. The algorithm for the identification of slow wave dynamics for every person was constructed in order to determine meaningful interrelationships between the participants and the local magnetic field data. The results support the hypothesis that the slow wave rhythms in heart rate variability can synchronize with changes in local magnetic field data, and that the degree of synchronization is affected by the quality of interpersonal relationships.

Ultrasonic sensor and method of use

DOEpatents

Condreva, Kenneth J.

2001-01-01

An ultrasonic sensor system and method of use for measuring transit time though a liquid sample, using one ultrasonic transducer coupled to a precision time interval counter. The timing circuit captures changes in transit time, representing small changes in the velocity of sound transmitted, over necessarily small time intervals (nanoseconds) and uses the transit time changes to identify the presence of non-conforming constituents in the sample.

Planetary period oscillations in Saturn's magnetosphere: comments on the relation between post-equinox periods determined from magnetic field and SKR emission data

NASA Astrophysics Data System (ADS)

Cowley, S. W. H.; Provan, G.

2015-07-01

We discuss the properties of Saturn planetary period oscillations (PPOs) deduced from analysis of Saturn kilometric radiation (SKR) modulations by Fischer et al. (2014), and from prior analysis of magnetic field oscillations data by Andrews et al. (2012) and Provan et al. (2013), with emphasis on the post-equinox interval from early 2010 to early 2013. Fischer et al. (2014) characterize this interval as showing single phase-locked periods in the northern and southern SKR modulations observed in polarization-separated data, while the magnetic data generally show the presence of separated dual periods, northern remaining shorter than southern. We show that the single SKR period corresponds to the southern magnetic period early in 2010, segues into the northern period in late 2010, and returns to the southern period in mid-2012, approximately in line with changes in the dominant magnetic oscillation. An exception occurs in mid-February to late August 2011 when two periods are again discerned in SKR data, in good agreement with the ongoing dual periods in the magnetic data. Fischer et al. (2014) discuss this change in terms of a large jump in the southern SKR period related to the Great White Spot storm, which the magnetic data show is primarily due instead to a reappearance in the SKR data of the ongoing southern modulation in a transitory interval of resumed southern dominance. In the earlier interval from early April 2010 to mid-February 2011 when Fischer et al. (2014) deduce single phase-locked periods, we show unequivocal evidence in the magnetic data for the presence of separated dual oscillations of approximately equal amplitude. We suggest that the apparent single SKR periods result from a previously reported phenomenon in which modulations associated with one hemisphere appear in polarization-separated data associated with the other. In the following interval, mid-August 2011 to early April 2012, when Fischer et al. (2014) again report phase-locked northern and southern oscillations, no ongoing southern oscillation of separate period is discerned in the magnetic data. However, the magnetic amplitude data show that if a phase-locked southern oscillation is indeed present, its amplitude must be less than ~ 5-10 % of the northern oscillation.

Multilayer Perceptron for Robust Nonlinear Interval Regression Analysis Using Genetic Algorithms

PubMed Central

2014-01-01

On the basis of fuzzy regression, computational models in intelligence such as neural networks have the capability to be applied to nonlinear interval regression analysis for dealing with uncertain and imprecise data. When training data are not contaminated by outliers, computational models perform well by including almost all given training data in the data interval. Nevertheless, since training data are often corrupted by outliers, robust learning algorithms employed to resist outliers for interval regression analysis have been an interesting area of research. Several approaches involving computational intelligence are effective for resisting outliers, but the required parameters for these approaches are related to whether the collected data contain outliers or not. Since it seems difficult to prespecify the degree of contamination beforehand, this paper uses multilayer perceptron to construct the robust nonlinear interval regression model using the genetic algorithm. Outliers beyond or beneath the data interval will impose slight effect on the determination of data interval. Simulation results demonstrate that the proposed method performs well for contaminated datasets. PMID:25110755

Multilayer perceptron for robust nonlinear interval regression analysis using genetic algorithms.

PubMed

Hu, Yi-Chung

2014-01-01

On the basis of fuzzy regression, computational models in intelligence such as neural networks have the capability to be applied to nonlinear interval regression analysis for dealing with uncertain and imprecise data. When training data are not contaminated by outliers, computational models perform well by including almost all given training data in the data interval. Nevertheless, since training data are often corrupted by outliers, robust learning algorithms employed to resist outliers for interval regression analysis have been an interesting area of research. Several approaches involving computational intelligence are effective for resisting outliers, but the required parameters for these approaches are related to whether the collected data contain outliers or not. Since it seems difficult to prespecify the degree of contamination beforehand, this paper uses multilayer perceptron to construct the robust nonlinear interval regression model using the genetic algorithm. Outliers beyond or beneath the data interval will impose slight effect on the determination of data interval. Simulation results demonstrate that the proposed method performs well for contaminated datasets.

FSILP: fuzzy-stochastic-interval linear programming for supporting municipal solid waste management.

PubMed

Li, Pu; Chen, Bing

2011-04-01

Although many studies on municipal solid waste management (MSW management) were conducted under uncertain conditions of fuzzy, stochastic, and interval coexistence, the solution to the conventional linear programming problems of integrating fuzzy method with the other two was inefficient. In this study, a fuzzy-stochastic-interval linear programming (FSILP) method is developed by integrating Nguyen's method with conventional linear programming for supporting municipal solid waste management. The Nguyen's method was used to convert the fuzzy and fuzzy-stochastic linear programming problems into the conventional linear programs, by measuring the attainment values of fuzzy numbers and/or fuzzy random variables, as well as superiority and inferiority between triangular fuzzy numbers/triangular fuzzy-stochastic variables. The developed method can effectively tackle uncertainties described in terms of probability density functions, fuzzy membership functions, and discrete intervals. Moreover, the method can also improve upon the conventional interval fuzzy programming and two-stage stochastic programming approaches, with advantageous capabilities that are easily achieved with fewer constraints and significantly reduces consumption time. The developed model was applied to a case study of municipal solid waste management system in a city. The results indicated that reasonable solutions had been generated. The solution can help quantify the relationship between the change of system cost and the uncertainties, which could support further analysis of tradeoffs between the waste management cost and the system failure risk. Copyright © 2010 Elsevier Ltd. All rights reserved.

Astrochronology of the Pliensbachian-Toarcian transition in the Foum Tillicht section (central High Atlas, Morroco)

NASA Astrophysics Data System (ADS)

Martinez, Mathieu; Bodin, Stéphane; Krencker, François-Nicolas

2015-04-01

The Pliensbachian and Toarcian stages (Early Jurassic) are marked by a series of carbon cycle disturbances, major climatic changes and severe faunal turnovers. An accurate knowledge of the timing of the Pliensbachian-Toarcian age is a key for quantifying fluxes and rhythms of faunal and geochemical processes during these major environmental perturbations. Although many studies provided astrochronological frameworks of the Toarcian Stage and the Toarcian oceanic anoxic event, no precise time frame exists for the Pliensbachian-Toarcian transition, often condensed in the previously studied sections. Here, we provide an astrochronology of the Pliensbachian-Toarcian transition in the Foum Tillicht section (central High Atlas, Morocco). The section is composed of decimetric hemipelagic marl-limestone alternations accompanied by cyclic fluctuations in the δ13Cmicrite. In this section, the marl-limestone alternations reflect cyclic sea-level/climatic changes, which triggers rhythmic migrations of the surrounding carbonate platforms and modulates the amount of carbonate exported to the basin. The studied interval encompasses 142.15 m of the section, from the base of the series to a hiatus in the Early Toarcian, marked by an erosional surface. The Pliensbachian-Toarcian (P-To) Event, a negative excursion in carbonate δ13Cmicrite, is observed pro parte in this studied interval. δ13Cmicrite measurements were performed every ~2 m at the base of the section and every 0.20 m within the P-To Event interval. Spectral analyses were performed using the multi-taper method and the evolutive Fast Fourier Transform to get the accurate assessment of the main significant periods and their evolution throughout the studied interval. Two main cycles are observed in the series: the 405-kyr eccentricity cycles is observed throughout the series, while the obliquity cycles is observed within the P-To Event, in the most densely sampled interval. The studied interval covers a 3.6-Myr interval. The duration of the part of P-To Event covered in this analysis is assessed at 0.70 Myr. In addition, the interval from the base of the Toarcian to the first occurrence of the calcareous nannofossil C. superbus has a duration assessed from 0.47 to 0.55 Myr. This duration is significantly higher than most of assessments obtained by former cyclostratigraphy analyses, showing that previous studies underestimated the duration of this interval, often condensed in the Western Tethys. This study shows the potential of the Foum Tillicht section to provide a refined time frame of the Pliensbachian-Toarcian boundary, which could be integrated in the next Geological Time Scale.

The climatic characteristics of extreme precipitations for short-term intervals in the watershed of Lake Maggiore

NASA Astrophysics Data System (ADS)

Saidi, Helmi; Ciampittiello, Marzia; Dresti, Claudia; Ghiglieri, Giorgio

2013-07-01

Alpine and Mediterranean areas are undergoing a profound change in the typology and distribution of rainfall. In particular, there has been an increase in consecutive non-rainy days, and an escalation of extreme rainy events. The climatic characteristic of extreme precipitations over short-term intervals is an object of study in the watershed of Lake Maggiore, the second largest freshwater basin in Italy (located in the north-west of the country) and an important resource for tourism, fishing and commercial flower growing. The historical extreme rainfall series with high-resolution from 5 to 45 min and above: 1, 2, 3, 6, 12 and 24 h collected at different gauges located at representative sites in the watershed of Lake Maggiore, have been computed to perform regional frequency analysis of annual maxima precipitation based on the L-moments approach, and to produce growth curves for different return-period rainfall events. Because of different rainfall-generating mechanisms in the watershed of Lake Maggiore such as elevation, no single parent distribution could be found for the entire study area. This paper concerns an investigation designed to give a first view of the temporal change and evolution of annual maxima precipitation, focusing particularly on both heavy and extreme events recorded at time intervals ranging from few minutes to 24 h and also to create and develop an extreme storm precipitation database, starting from historical sub-daily precipitation series distributed over the territory. There have been two-part changes in extreme rainfall events occurrence in the last 23 years from 1987 to 2009. Little change is observed in 720 min and 24-h precipitations, but the change seen in 5, 10, 15, 20, 30, 45, 60, 120, 180 and 360 min events is significant. In fact, during the 2000s, growth curves have flattened and annual maxima have decreased.

Overuse of short-interval bone densitometry: assessing rates of low-value care.

PubMed

Morden, N E; Schpero, W L; Zaha, R; Sequist, T D; Colla, C H

2014-09-01

We evaluated the prevalence and geographic variation of short-interval (repeated in under 2 years) dual-energy X-ray absorptiometry tests (DXAs) among Medicare beneficiaries. Short-interval DXA use varied across regions (coefficient of variation = 0.64), and unlike other DXAs, rates decreased with payment cuts. The American College of Rheumatology, through the Choosing Wisely initiative, identified measuring bone density more often than every 2 years as care "physicians and patients should question." We measured the prevalence and described the geographic variation of short-interval (repeated in under 2 years) DXAs among Medicare beneficiaries and estimated the cost of this testing and its responsiveness to payment change. Using 100 % Medicare claims data, 2006-2011, we identified DXAs and short-interval DXAs for female Medicare beneficiaries over age 66. We determined the population rate of DXAs and short-interval DXAs, as well as Medicare spending on short-interval DXAs, nationally and by hospital referral region (HRR). DXA use was stable 2008-2011 (12.4 to 11.5 DXAs per 100 women). DXA use varied across HRRs: in 2011, overall DXA use ranged from 6.3 to 23.0 per 100 women (coefficient of variation = 0.18), and short-interval DXAs ranged from 0.3 to 8.0 per 100 women (coefficient of variation = 0.64). Short-interval DXA use fluctuated substantially with payment changes; other DXAs did not. Short-interval DXAs, which represented 10.1 % of all DXAs, cost Medicare approximately US$16 million in 2011. One out of ten DXAs was administered in a time frame shorter than recommended and at a substantial cost to Medicare. DXA use varied across regions. Short-interval DXA use was responsive to reimbursement changes, suggesting carefully designed policy and payment reform may reduce this care identified by rheumatologists as low value.

The status of BAT detector

NASA Astrophysics Data System (ADS)

Lien, Amy; Markwardt, Craig B.; Krimm, Hans Albert; Barthelmy, Scott D.; Cenko, Bradley

2018-01-01

We will present the current status of the Swift/BAT detector. In particular, we will report the updated detector gain calibration, the number of enable detectors, and the global bad time intervals with potential calibration issues. We will also summarize the results of the yearly BAT calibration using the Crab nebula. Finally, we will discuss the effects on the BAT survey, such as the sensitivity, localization, and spectral analysis, due to the changes in detector status.

Automatic recognition of vector and parallel operations in a higher level language

NASA Technical Reports Server (NTRS)

Schneck, P. B.

1971-01-01

A compiler for recognizing statements of a FORTRAN program which are suited for fast execution on a parallel or pipeline machine such as Illiac-4, Star or ASC is described. The technique employs interval analysis to provide flow information to the vector/parallel recognizer. Where profitable the compiler changes scalar variables to subscripted variables. The output of the compiler is an extension to FORTRAN which shows parallel and vector operations explicitly.

Trajectory of social isolation following hip fracture: an analysis of the English Longitudinal Study of Ageing (ELSA) cohort.

PubMed

Smith, Toby O; Dainty, Jack R; MacGregor, Alex

2018-01-01

social isolation is defined as a lack of meaningful and sustained communication or interactions with social networks. There is limited understanding on the prevalence of social isolation and loneliness in people following hip fracture and no previous understanding of how this changes over time. to determine the prevalence and trajectory of social isolation and loneliness before a hip fracture, during the recovery phase and a minimum of 2 years post-hip fracture in an English population. data were from the English Longitudinal Study of Ageing (ELSA) cohort (2004/5-2014/15). The sample comprised of 215 participants who had sustained a hip fracture. Measures of social isolation and loneliness were analysed through multilevel modelling to determine their trajectories during three-time intervals (pre-fracture; interval at hip fracture and recovery; minimum 2 years post-fracture). The prevalence of social isolation and loneliness were determined pre- and post-fracture. prevalence of social isolation was 19% post-hip fracture and loneliness 13% post-hip fracture. There was no statistically significant change in social isolation pre-fracture compared to a minimum of 2 years post-fracture (P = 0.78). Similarly, there was no statistically significant change in loneliness pre-fracture compared to a minimum of 2 years post-fracture (P = 0.12). this analysis has determined that whilst social isolation and loneliness do not change over time following hip fracture, these remain a significant problem for this population. Interventions are required to address these physical and psychological health needs. This is important as they may have short and longer term health benefits for people post-hip fracture. © The Author 2017. Published by Oxford University Press on behalf of the British Geriatrics Society.All rights reserved. For permissions, please email: journals.permissions@oup.com

Cenozoic climate changes: A review based on time series analysis of marine benthic δ18O records

NASA Astrophysics Data System (ADS)

Mudelsee, Manfred; Bickert, Torsten; Lear, Caroline H.; Lohmann, Gerrit

2014-09-01

The climate during the Cenozoic era changed in several steps from ice-free poles and warm conditions to ice-covered poles and cold conditions. Since the 1950s, a body of information on ice volume and temperature changes has been built up predominantly on the basis of measurements of the oxygen isotopic composition of shells of benthic foraminifera collected from marine sediment cores. The statistical methodology of time series analysis has also evolved, allowing more information to be extracted from these records. Here we provide a comprehensive view of Cenozoic climate evolution by means of a coherent and systematic application of time series analytical tools to each record from a compilation spanning the interval from 4 to 61 Myr ago. We quantitatively describe several prominent features of the oxygen isotope record, taking into account the various sources of uncertainty (including measurement, proxy noise, and dating errors). The estimated transition times and amplitudes allow us to assess causal climatological-tectonic influences on the following known features of the Cenozoic oxygen isotopic record: Paleocene-Eocene Thermal Maximum, Eocene-Oligocene Transition, Oligocene-Miocene Boundary, and the Middle Miocene Climate Optimum. We further describe and causally interpret the following features: Paleocene-Eocene warming trend, the two-step, long-term Eocene cooling, and the changes within the most recent interval (Miocene-Pliocene). We review the scope and methods of constructing Cenozoic stacks of benthic oxygen isotope records and present two new latitudinal stacks, which capture besides global ice volume also bottom water temperatures at low (less than 30°) and high latitudes. This review concludes with an identification of future directions for data collection, statistical method development, and climate modeling.

[The effect of esmolol on corrected-QT interval, corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients taking an angiotensin-converting enzyme inhibitor].

PubMed

Ceker, Zahit; Takmaz, Suna Akın; Baltaci, Bülent; Başar, Hülya

2015-01-01

The importance of minimizing the exaggerated sympatho-adrenergic responses and QT interval and QT interval dispersion changes that may develop due to laryngoscopy and tracheal intubation during anesthesia induction in the hypertensive patients is clear. Esmolol decreases the hemodynamic response to laryngoscopy and intubation. However, the effect of esmolol in decreasing the prolonged QT interval and QT interval dispersion as induced by laryngoscopy and intubation is controversial. We investigated the effect of esmolol on the hemodynamic, and corrected-QT interval and corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients using angiotensin converting enzyme inhibitors. 60 ASA I-II patients, with essential hypertension using angiotensin converting enzyme inhibitors were included in the study. The esmolol group received esmolol at a bolus dose of 500mcg/kg followed by a 100mcg/kg/min infusion which continued until the 4th min after intubation. The control group received 0.9% saline similar to the esmolol group. The mean blood pressure, heart rate values and the electrocardiogram records were obtained as baseline values before the anesthesia, 5min after esmolol and saline administration, 3min after the induction and 30s, 2min and 4min after intubation. The corrected-QT interval was shorter in the esmolol group (p=0.012), the corrected-QT interval dispersion interval was longer in the control group (p=0.034) and the mean heart rate was higher in the control group (p=0.022) 30s after intubation. The risk of arrhythmia frequency was higher in the control group in the 4-min period following intubation (p=0.038). Endotracheal intubation was found to prolong corrected-QT interval and corrected-QT interval dispersion, and increase the heart rate during anesthesia induction with propofol in hypertensive patients using angiotensin converting enzyme inhibitors. These effects were prevented with esmolol (500mcg/kg bolus, followed by 100mcg/kg/min infusion). During induction, the blood pressure tends to decrease with esmolol where care is needed. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Global distribution of moisture, evaporation-precipitation, and diabatic heating rates

NASA Technical Reports Server (NTRS)

Christy, John R.

1989-01-01

Global archives were established for ECMWF 12-hour, multilevel analysis beginning 1 January 1985; day and night IR temperatures, and solar incoming and solar absorbed. Routines were written to access these data conveniently from NASA/MSFC MASSTOR facility for diagnostic analysis. Calculations of diabatic heating rates were performed from the ECMWF data using 4-day intervals. Calculations of precipitable water (W) from 1 May 1985 were carried out using the ECMWF data. Because a major operational change on 1 May 1985 had a significant impact on the moisture field, values prior to that date are incompatible with subsequent analyses.

Regional differences of urbanization in the conterminous U.S. on upland forest land cover, 1973-2011

USGS Publications Warehouse

Auch, Roger F.; Drummond, Mark A.; Xian, George Z.; Sayler, Kristi L.; Acevedo, William; Taylor, Janis

2016-01-01

In this U.S. Geological Survey study of forest land cover across the conterminous U.S. (CONUS), specific proportions and rates of forest conversion to developed (urban) land were assessed on an ecoregional basis. The study period was divided into six time intervals between 1973 and 2011. Forest land cover was the source of 40% or more of the new urban land in 35 of the 84 ecoregions located within the CONUS. In 11 of these ecoregions this threshold exceeded in every time interval. When the percent of change, forest to urban, was compared to the percent of forest in each ecoregion, 58 ecoregions had a greater percent of change and, in six of those, change occurred in every time interval. Annual rates of forest to urban land cover change of 0.2% or higher occurred in 12 ecoregions at least once and in one ecoregion in all intervals. There were three ecoregions where the above conditions were met for nearly every time interval. Even though only a small number of the ecoregions were heavily impacted by forest loss to urban development within the CONUS, the ecosystem services provided by undeveloped forest land cover need to be quantified more completely to better inform future regional land management.

Sudden Death After Febrile Seizure Case Report: Cerebral Suppression Precedes Severe Bradycardia.

PubMed

Myers, Kenneth A; McPherson, Robyn E; Clegg, Robin; Buchhalter, Jeffrey

2017-11-01

A 20-month-old girl with a complex chromosomal disorder had first presentation of febrile status epilepticus and was admitted to the hospital. Two days after her initial seizure, she died suddenly and unexpectedly during a video EEG monitoring study. An advanced analysis of the physiologic changes in the hours and minutes leading up to death was undertaken. The electrocardiography over the last 19 minutes of life was reviewed, and the R-R intervals were manually measured. Heart rate variability was assessed through calculation of the SD of the R-R intervals and the root mean square of successive differences over successive 100 beat periods. Instantaneous heart rate, SD of the R-R intervals, the root mean square of successive differences, and oxygen saturation were plotted against time over the last 19 minutes of life. Diffuse cerebral suppression on EEG was observed 10 minutes before death, followed minutes later by severe bradycardia and increased heart rate variability. Although the child did not meet criteria for a diagnosis of epilepsy, the sequence of physiologic changes leading up to death suggests a pathophysiology similar to sudden unexplained death in epilepsy. A comparable pattern of diffuse cerebral suppression preceding parasympathetic overactivity has been suggested in some rare cases of adults who have experienced sudden unexplained death in epilepsy during video EEG monitoring. Copyright © 2017 by the American Academy of Pediatrics.

Meta-analysis of lamb birth weight as influenced by pregnancy nutrition of multiparous ewes.

PubMed

Roca Fraga, Fernando J; Lagisz, Malgorzata; Nakagawa, Shinichi; Lopez-Villalobos, Nicolas; Blair, Hugh T; Kenyon, Paul R

2018-05-04

Across the literature, there is large variation in lamb birth weight responses to changes in the ewe pregnancy nutrition. Much of this heterogeneity has been attributed to several factors inherent to each experiment; however, the relative contribution of these experimental factors has not yet been quantified. This meta-analysis aimed to systematically review the variation in lamb birth weight responses across nutritional studies involving adult multiparous ewes. Effect-sizes for individual studies were estimated using the unbiased estimator Hedges' g, whereby positive and negative values indicate heavier and lighter treatment lambs vs. controls, respectively. Heterogeneity varied between early-, mid- and late-pregnancy undernutrition studies (I2total [early pregnancy] = 19.90%, I2total [midpregnancy] = 52.10%, I2total [late pregnancy] = 68.70%). The small average effects for early- (0.04, highest posterior density [HPD] interval = -0.22, 0.28) and mid-pregnancy undernutrition (-0.15, HPD interval = -0.35, 0.05) suggest that if farmers anticipate a potential feed shortage, ewes can be allowed to lose weight providing nutrition is resumed to adequate levels later in pregnancy. On the contrary, late-pregnancy undernutrition was associated with a significant decrease in lamb birth weight (-0.72, HPD interval = -0.86, -0.55). Thus, management practices should focus on ensuring adequate nutrition in late pregnancy. Increasing lamb birth weight could be possible by feeding ewes above their pregnancy maintenance requirement (0.23, HPD interval = 0.002, 0.48), though the number of studies is limited and further research is needed.

The association between short interpregnancy interval and preterm birth in Louisiana: a comparison of methods.

PubMed

Howard, Elizabeth J; Harville, Emily; Kissinger, Patricia; Xiong, Xu

2013-07-01

There is growing interest in the application of propensity scores (PS) in epidemiologic studies, especially within the field of reproductive epidemiology. This retrospective cohort study assesses the impact of a short interpregnancy interval (IPI) on preterm birth and compares the results of the conventional logistic regression analysis with analyses utilizing a PS. The study included 96,378 singleton infants from Louisiana birth certificate data (1995-2007). Five regression models designed for methods comparison are presented. Ten percent (10.17 %) of all births were preterm; 26.83 % of births were from a short IPI. The PS-adjusted model produced a more conservative estimate of the exposure variable compared to the conventional logistic regression method (β-coefficient: 0.21 vs. 0.43), as well as a smaller standard error (0.024 vs. 0.028), odds ratio and 95 % confidence intervals [1.15 (1.09, 1.20) vs. 1.23 (1.17, 1.30)]. The inclusion of more covariate and interaction terms in the PS did not change the estimates of the exposure variable. This analysis indicates that PS-adjusted regression may be appropriate for validation of conventional methods in a large dataset with a fairly common outcome. PS's may be beneficial in producing more precise estimates, especially for models with many confounders and effect modifiers and where conventional adjustment with logistic regression is unsatisfactory. Short intervals between pregnancies are associated with preterm birth in this population, according to either technique. Birth spacing is an issue that women have some control over. Educational interventions, including birth control, should be applied during prenatal visits and following delivery.

The effects of morphine on fixed-interval patterning and temporal discrimination.

PubMed Central

Odum, A L; Schaal, D W

2000-01-01

Changes produced by drugs in response patterns under fixed-interval schedules of reinforcement have been interpreted to result from changes in temporal discrimination. To examine this possibility, this experiment determined the effects of morphine on the response patterning of 4 pigeons during a fixed-interval 1-min schedule of food delivery with interpolated temporal discrimination trials. Twenty of the 50 total intervals were interrupted by choice trials. Pecks to one key color produced food if the interval was interrupted after a short time (after 2 or 4.64 s). Pecks to another key color produced food if the interval was interrupted after a long time (after 24.99 or 58 s). Morphine (1.0 to 10.0 mg/kg) decreased the index of curvature (a measure of response patterning) during fixed intervals and accuracy during temporal discrimination trials. Accuracy was equally disrupted following short and long sample durations. Although morphine disrupted temporal discrimination in the context of a fixed-interval schedule, these effects are inconsistent with interpretations of the disruption of response patterning as a selective overestimation of elapsed time. The effects of morphine may be related to the effects of more conventional external stimuli on response patterning. PMID:11029024

The Digital Shoreline Analysis System (DSAS) Version 4.0 - An ArcGIS extension for calculating shoreline change

USGS Publications Warehouse

Thieler, E. Robert; Himmelstoss, Emily A.; Zichichi, Jessica L.; Ergul, Ayhan

2009-01-01

The Digital Shoreline Analysis System (DSAS) version 4.0 is a software extension to ESRI ArcGIS v.9.2 and above that enables a user to calculate shoreline rate-of-change statistics from multiple historic shoreline positions. A user-friendly interface of simple buttons and menus guides the user through the major steps of shoreline change analysis. Components of the extension and user guide include (1) instruction on the proper way to define a reference baseline for measurements, (2) automated and manual generation of measurement transects and metadata based on user-specified parameters, and (3) output of calculated rates of shoreline change and other statistical information. DSAS computes shoreline rates of change using four different methods: (1) endpoint rate, (2) simple linear regression, (3) weighted linear regression, and (4) least median of squares. The standard error, correlation coefficient, and confidence interval are also computed for the simple and weighted linear-regression methods. The results of all rate calculations are output to a table that can be linked to the transect file by a common attribute field. DSAS is intended to facilitate the shoreline change-calculation process and to provide rate-of-change information and the statistical data necessary to establish the reliability of the calculated results. The software is also suitable for any generic application that calculates positional change over time, such as assessing rates of change of glacier limits in sequential aerial photos, river edge boundaries, land-cover changes, and so on.

Atlas of interoccurrence intervals for selected thresholds of daily precipitation in Texas

USGS Publications Warehouse

Asquith, William H.; Roussel, Meghan C.

2003-01-01

A Poisson process model is used to define the distribution of interoccurrence intervals of daily precipitation in Texas. A precipitation interoccurrence interval is the time period between two successive rainfall events. Rainfall events are defined as daily precipitation equaling or exceeding a specified depth threshold. Ten precipitation thresholds are considered: 0.05, 0.10, 0.25, 0.50, 0.75, 1.0, 1.5, 2.0, 2.5, and 3.0 inches. Site-specific mean interoccurrence interval and ancillary statistics are presented for each threshold and for each of 1,306 National Weather Service daily precipitation gages. Maps depicting the spatial variation across Texas of the mean interoccurrence interval for each threshold are presented. The percent change from the statewide standard deviation of the interoccurrence intervals to the root-mean-square error ranges from a magnitude minimum of (negative) -24 to a magnitude maximum of -60 percent for the 0.05- and 2.0-inch thresholds, respectively. Because of the substantial negative percent change, the maps are considered more reliable estimators of the mean interoccurrence interval for most locations in Texas than the statewide mean values.

Uptake of recommended common reference intervals for chemical pathology in Australia.

PubMed

Jones, Graham Rd; Koetsier, Sabrina

2017-05-01

Background Reference intervals are a vital part of reporting numerical pathology results. It is known, however, that variation in reference intervals between laboratories is common, even when analytical methods support common reference intervals. In response to this, in Australia, the Australasian Association of Clinical Biochemists together with the Royal College of Pathologists of Australasia published in 2014 a set of recommended common reference intervals for 11 common serum analytes (sodium, potassium, chloride, bicarbonate, creatinine male, creatinine female, calcium, calcium adjusted for albumin, phosphate, magnesium, lactate dehydrogenase, alkaline phosphatase and total protein). Methods Uptake of recommended common reference intervals in Australian laboratories was assessed using data from four annual cycles of the RCPAQAP reference intervals external quality assurance programme. Results Over three years, from 2013 to 2016, the use of the recommended upper and lower reference limits has increased from 40% to 83%. Nearly half of the intervals in use by enrolled laboratories in 2016 have been changed in this time period, indicating an active response to the guidelines. Conclusions These data support the activities of the Australasian Association of Clinical Biochemists and Royal College of Pathologists of Australasia in demonstrating a change in laboratory behaviour to reduce unnecessary variation in reference intervals and thus provide a consistent message to doctor and patients irrespective of the laboratory used.

[A study on the relationship between postmortem interval and the changes of DNA content in the kidney cellule of rat].

PubMed

Liu, L; Peng, D B; Liu, Y; Deng, W N; Liu, Y L; Li, J J

2001-05-01

To study changes of DNA content in the kidney cellule of rats and relationship with the postmortem interval. This experiment chose seven parameter of cell nuclear, including the area and integral optical density, determined the changes of DNA content in the kidney cellule of 15 rats at different intervals between 0 and 48 h postmortem with auto-TV-image system. The degradation rate of DNA in nuclear has a certainty relationship to early PMI(in 48 h) of rat, and get binomial regress equation. Determining the quantity of DNA in nuclear should be an objective and exact way to estimate the PMI.

Bridging the Faraoni and Selli oceanic anoxic events: short and repetitive dys- and anaerobic episodes during the late Hauterivian to early Aptian in the central Tethys

NASA Astrophysics Data System (ADS)

Föllmi, K. B.; Bôle, M.; Jammet, N.; Froidevaux, P.; Godet, A.; Bodin, S.; Adatte, T.; Matera, V.; Fleitmann, D.; Spangenberg, J. E.

2011-06-01

A detailed stratigraphical and geochemical analysis was performed on the upper part of the Maiolica Formation outcropping in the Breggia (southern Switzerland) and Capriolo sections (northern Italy). In these localities, the Maiolica Formation consists of well-bedded, partly siliceous, pelagic, micritic carbonate, which lodges numerous thin, dark and organic-rich layers. Stable-isotope, phosphorus, organic-carbon and a suite of redox-sensitive trace-metal contents (RSTE: Mo, U, Co, V and As) were measured. Higher densities of organic-rich layers were identified in the uppermost Hauterivian, lower Barremian and the Barremian-Aptian boundary intervals, whereas the upper Barremian interval and the interval immediately following the Barremian-Aptian boundary interval are characterized by lower densities of organic-rich layers. TOC contents, RSTE pattern and Corg:Ptot ratios indicate that most layers were deposited under dysaerobic rather than anaerobic conditions and that latter conditions were likely restricted to short intervals in the latest Hauterivian, the early Barremian and the pre-Selli early Aptian. Correlations are possible with organic-rich intervals in central Italy (the Gorgo a Cerbara section) and the Boreal northwest German Basin, and with the facies and drowning pattern in the evolution of the Helvetic segment of the northern Tethyan carbonate platform. Our data and correlations suggest that the latest Hauterivian witnessed the progressive installation of dysaerobic conditions in the Tethys, which went along with the onset in sediment condensation, phosphogenesis and platform drowning on the northern Tethyan margin, and which culminated in the Faraoni anoxic episode. This brief episode is followed by further episodes of dysaerobic conditions in the Tethys and the northwest German Basin, which became more frequent and progressively stronger in the late early Barremian. Platform drowning persisted and did not halt before the latest early Barremian. The late Barremian witnessed diminishing frequencies and intensities in dysaerobic conditions, which went along with the progressive installation of the Urgonian carbonate platform. Near the Barremian-Aptian boundary, the increasing density in dysaerobic episodes in the Tethyan and northwest German Basins is paralleled by a change towards heterozoan carbonate production on the northern Tethyan shelf. The following return to more oxygenated conditions is correlated with the second phase of Urgonian platform growth and the period immediately preceding and corresponding to the Selli anoxic episode is characterized by renewed platform drowning and the change to heterozoan carbonate production. Changes towards more humid climate conditions were likely the cause for the repetitive installation of dys- to anaerobic conditions in the Tethyan and Boreal basins and the accompanying changes in the evolution of the carbonate platform towards heterozoan carbonate-producing ecosystems and platform drowning.

Analysis of health care claims during the peri-transfer stage of transition from pediatric to adult care among juvenile idiopathic arthritis patients.

PubMed

Mannion, Melissa L; Xie, Fenglong; Baddley, John; Chen, Lang; Curtis, Jeffrey R; Saag, Kenneth; Zhang, Jie; Beukelman, Timothy

2016-09-05

To investigate the utilization of health care services before and after transfer from pediatric to adult rheumatology care in clinical practice. Using US commercial claims data from January 2005 through August 2012, we identified individuals with a JIA diagnosis code from a pediatric rheumatologist followed by any diagnosis code from an adult rheumatologist. Individuals had 6 months observable time before the last pediatric visit and 6 months after the first adult visit. Medication, emergency room, physical therapy use, and diagnosis codes were compared between the pediatric and adult interval using McNemar's test. The proportion of days covered (PDC) of TNFi for the time between last pediatric and first adult visit was calculated. We identified 58 individuals with JIA who transferred from pediatric to adult rheumatology care after the age of 14. The median age at the last pediatric rheumatology visit was 18.1 years old and the median transfer interval was 195 days. 29 % of patients received NSAIDs in the adult interval compared to 43 % in the pediatric interval (p = 0.06). In the pediatric interval, 71 % received a JRA and 0 % received an RA physician diagnosis code compared to 28 and 45 %, respectively, in the adult interval. The median PDC for patients receiving a TNFi was 0.75 during the transfer interval. Individuals with JIA who transferred to adult care were more likely receive a diagnosis of RA instead of JRA and were less likely to receive NSAIDs, but had no significant immediate changes to other medication use.

Fear conditioning is associated with dynamic directed functional interactions between and within the human amygdala, hippocampus, and frontal lobe.

PubMed

Liu, C C; Crone, N E; Franaszczuk, P J; Cheng, D T; Schretlen, D S; Lenz, F A

2011-08-25

The current model of fear conditioning suggests that it is mediated through modules involving the amygdala (AMY), hippocampus (HIP), and frontal lobe (FL). We now test the hypothesis that habituation and acquisition stages of a fear conditioning protocol are characterized by different event-related causal interactions (ERCs) within and between these modules. The protocol used the painful cutaneous laser as the unconditioned stimulus and ERC was estimated by analysis of local field potentials recorded through electrodes implanted for investigation of epilepsy. During the prestimulus interval of the habituation stage FL>AMY ERC interactions were common. For comparison, in the poststimulus interval of the habituation stage, only a subdivision of the FL (dorsolateral prefrontal cortex, dlPFC) still exerted the FL>AMY ERC interaction (dlFC>AMY). For a further comparison, during the poststimulus interval of the acquisition stage, the dlPFC>AMY interaction persisted and an AMY>FL interaction appeared. In addition to these ERC interactions between modules, the results also show ERC interactions within modules. During the poststimulus interval, HIP>HIP ERC interactions were more common during acquisition, and deep hippocampal contacts exerted causal interactions on superficial contacts, possibly explained by connectivity between the perihippocampal gyrus and the HIP. During the prestimulus interval of the habituation stage, AMY>AMY ERC interactions were commonly found, while interactions between the deep and superficial AMY (indirect pathway) were independent of intervals and stages. These results suggest that the network subserving fear includes distributed or widespread modules, some of which are themselves "local networks." ERC interactions between and within modules can be either static or change dynamically across intervals or stages of fear conditioning. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

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.

Tracking a changing environment: optimal sampling, adaptive memory and overnight effects.

PubMed

Dunlap, Aimee S; Stephens, David W

2012-02-01

Foraging in a variable environment presents a classic problem of decision making with incomplete information. Animals must track the changing environment, remember the best options and make choices accordingly. While several experimental studies have explored the idea that sampling behavior reflects the amount of environmental change, we take the next logical step in asking how change influences memory. We explore the hypothesis that memory length should be tied to the ecological relevance and the value of the information learned, and that environmental change is a key determinant of the value of memory. We use a dynamic programming model to confirm our predictions and then test memory length in a factorial experiment. In our experimental situation we manipulate rates of change in a simple foraging task for blue jays over a 36 h period. After jays experienced an experimentally determined change regime, we tested them at a range of retention intervals, from 1 to 72 h. Manipulated rates of change influenced learning and sampling rates: subjects sampled more and learned more quickly in the high change condition. Tests of retention revealed significant interactions between retention interval and the experienced rate of change. We observed a striking and surprising difference between the high and low change treatments at the 24h retention interval. In agreement with earlier work we find that a circadian retention interval is special, but we find that the extent of this 'specialness' depends on the subject's prior experience of environmental change. Specifically, experienced rates of change seem to influence how subjects balance recent information against past experience in a way that interacts with the passage of time. Copyright © 2011 Elsevier B.V. All rights reserved.

Identification of Intensity Ratio Break Points from Photon Arrival Trajectories in Ratiometric Single Molecule Spectroscopy

PubMed Central

Bingemann, Dieter; Allen, Rachel M.

2012-01-01

We describe a statistical method to analyze dual-channel photon arrival trajectories from single molecule spectroscopy model-free to identify break points in the intensity ratio. Photons are binned with a short bin size to calculate the logarithm of the intensity ratio for each bin. Stochastic photon counting noise leads to a near-normal distribution of this logarithm and the standard student t-test is used to find statistically significant changes in this quantity. In stochastic simulations we determine the significance threshold for the t-test’s p-value at a given level of confidence. We test the method’s sensitivity and accuracy indicating that the analysis reliably locates break points with significant changes in the intensity ratio with little or no error in realistic trajectories with large numbers of small change points, while still identifying a large fraction of the frequent break points with small intensity changes. Based on these results we present an approach to estimate confidence intervals for the identified break point locations and recommend a bin size to choose for the analysis. The method proves powerful and reliable in the analysis of simulated and actual data of single molecule reorientation in a glassy matrix. PMID:22837704

Co-Variation of Tonality in the Music and Speech of Different Cultures

PubMed Central

Han, Shui' er; Sundararajan, Janani; Bowling, Daniel Liu; Lake, Jessica; Purves, Dale

2011-01-01

Whereas the use of discrete pitch intervals is characteristic of most musical traditions, the size of the intervals and the way in which they are used is culturally specific. Here we examine the hypothesis that these differences arise because of a link between the tonal characteristics of a culture's music and its speech. We tested this idea by comparing pitch intervals in the traditional music of three tone language cultures (Chinese, Thai and Vietnamese) and three non-tone language cultures (American, French and German) with pitch intervals between voiced speech segments. Changes in pitch direction occur more frequently and pitch intervals are larger in the music of tone compared to non-tone language cultures. More frequent changes in pitch direction and larger pitch intervals are also apparent in the speech of tone compared to non-tone language cultures. These observations suggest that the different tonal preferences apparent in music across cultures are closely related to the differences in the tonal characteristics of voiced speech. PMID:21637716

A dimension-wise analysis method for the structural-acoustic system with interval parameters

NASA Astrophysics Data System (ADS)

Xu, Menghui; Du, Jianke; Wang, Chong; Li, Yunlong

2017-04-01

The interval structural-acoustic analysis is mainly accomplished by interval and subinterval perturbation methods. Potential limitations for these intrusive methods include overestimation or interval translation effect for the former and prohibitive computational cost for the latter. In this paper, a dimension-wise analysis method is thus proposed to overcome these potential limitations. In this method, a sectional curve of the system response surface along each input dimensionality is firstly extracted, the minimal and maximal points of which are identified based on its Legendre polynomial approximation. And two input vectors, i.e. the minimal and maximal input vectors, are dimension-wisely assembled by the minimal and maximal points of all sectional curves. Finally, the lower and upper bounds of system response are computed by deterministic finite element analysis at the two input vectors. Two numerical examples are studied to demonstrate the effectiveness of the proposed method and show that, compared to the interval and subinterval perturbation method, a better accuracy is achieved without much compromise on efficiency by the proposed method, especially for nonlinear problems with large interval parameters.

Population-wide folic acid fortification and preterm birth: testing the folate depletion hypothesis.

PubMed

Naimi, Ashley I; Auger, Nathalie

2015-04-01

We assess whether population-wide folic acid fortification policies were followed by a reduction of preterm and early-term birth rates in Québec among women with short and optimal interpregnancy intervals. We extracted birth certificate data for 1.3 million births between 1981 and 2010 to compute age-adjusted preterm and early-term birth rates stratified by short and optimal interpregnancy intervals. We used Joinpoint regression to detect changes in the preterm and early term birth rates and assess whether these changes coincide with the implementation of population-wide folic acid fortification. A change in the preterm birth rate occurred in 2000 among women with short (95% confidence interval [CI] = 1994, 2005) and optimal (95% CI = 1995, 2008) interpregnancy intervals. Changes in early term birth rates did not coincide with the implementation of folic acid fortification. Our results do not indicate a link between folic acid fortification and early term birth but suggest an improvement in preterm birth rates after implementation of a nationwide folic acid fortification program.

Magnitude of increase in QTc interval after initiation of dofetilide in patients with persistent atrial fibrillation is associated with increased rates of pharmacological cardioversion and long-term freedom from recurrent atrial fibrillation.

PubMed

Huang, Henry D; Waks, Jonathan W; Steinhaus, Daniel A; Zimetbaum, Peter

2016-07-01

Dofetilide is a class III antiarrhythmic drug approved for the treatment of atrial fibrillation (AF). Dofetilide-induced corrected QT (QTc) interval prolongation is a surrogate for the degree of drug effect, but the relationships between drug-induced QTc interval prolongation, pharmacological cardioversion (PCV), and freedom from recurrent AF are unclear. The purpose of this study was to assess associations between QTc interval change during dofetilide initiation and PCV and long-term AF recurrence. We performed retrospective analyses of a prospective cohort of patients with AF admitted for dofetilide initiation between 2001 and 2014. Clinical characteristics and electrocardiographic variables were assessed. We evaluated outcomes of successful PCV in patients with persistent AF and time to recurrence of AF in patients with paroxysmal and persistent AF. During the study, 243 patients with persistent AF and 176 patients with paroxysmal AF initiated dofetilide. PCV occurred in 93/243 (41.7%) patients with persistent AF. After multivariable adjustment, QTc interval change was associated with PCV (adjusted odds ratio 1.21; P = .003 per 10-ms QTc increase). Inhospital QTc interval change was associated with long-term freedom from AF in patients with persistent AF (adjusted hazard ratio 0.92; P = .011 at 4 years per 10-ms QTc increase), but not in patients with paroxysmal AF. In patients with persistent AF, PCV was also associated with long-term freedom from recurrent AF (adjusted hazard ratio 0.62; P = .009 at 4 years). The magnitude of QTc interval prolongation during dofetilide initiation is an independent predictor of successful PCV and long-term freedom from arrhythmia in patients with persistent AF. QTc interval change had no association with AF recurrence in patients with paroxysmal AF, suggesting that different mechanisms of arrhythmogenesis may be operant in different AF types. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

The impact of communicating genetic risks of disease on risk-reducing health behaviour: systematic review with meta-analysis.

PubMed

Hollands, Gareth J; French, David P; Griffin, Simon J; Prevost, A Toby; Sutton, Stephen; King, Sarah; Marteau, Theresa M

2016-03-15

To assess the impact of communicating DNA based disease risk estimates on risk-reducing health behaviours and motivation to engage in such behaviours. Systematic review with meta-analysis, using Cochrane methods. Medline, Embase, PsycINFO, CINAHL, and the Cochrane Central Register of Controlled Trials up to 25 February 2015. Backward and forward citation searches were also conducted. Randomised and quasi-randomised controlled trials involving adults in which one group received personalised DNA based estimates of disease risk for conditions where risk could be reduced by behaviour change. Eligible studies included a measure of risk-reducing behaviour. We examined 10,515 abstracts and included 18 studies that reported on seven behavioural outcomes, including smoking cessation (six studies; n=2663), diet (seven studies; n=1784), and physical activity (six studies; n=1704). Meta-analysis revealed no significant effects of communicating DNA based risk estimates on smoking cessation (odds ratio 0.92, 95% confidence interval 0.63 to 1.35, P=0.67), diet (standardised mean difference 0.12, 95% confidence interval -0.00 to 0.24, P=0.05), or physical activity (standardised mean difference -0.03, 95% confidence interval -0.13 to 0.08, P=0.62). There were also no effects on any other behaviours (alcohol use, medication use, sun protection behaviours, and attendance at screening or behavioural support programmes) or on motivation to change behaviour, and no adverse effects, such as depression and anxiety. Subgroup analyses provided no clear evidence that communication of a risk-conferring genotype affected behaviour more than communication of the absence of such a genotype. However, studies were predominantly at high or unclear risk of bias, and evidence was typically of low quality. Expectations that communicating DNA based risk estimates changes behaviour is not supported by existing evidence. These results do not support use of genetic testing or the search for risk-conferring gene variants for common complex diseases on the basis that they motivate risk-reducing behaviour. This is a revised and updated version of a Cochrane review from 2010, adding 11 studies to the seven previously identified. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Optimizing donor heart outcome after prolonged storage with endothelial function analysis and continuous perfusion.

PubMed

Poston, Robert S; Gu, Junyan; Prastein, Deyanira; Gage, Fred; Hoffman, John W; Kwon, Michael; Azimzadeh, Agnes; Pierson, Richard N; Griffith, Bartley P

2004-10-01

By minimizing tissue ischemia, continuous perfusion (CP) during organ transport may increase the safety of "marginal donors." My colleagues and I investigated whether an analysis of donor heart viability predicts recovery of grafts challenged with a 24-hour preservation interval. Dog hearts underwent cold static storage (CS) for 8 hours (n = 8) or 24 hours (n = 2) or CP for 24 hours with cold asanguinous, oxygenated solution (n = 8). Myocardial systolic and diastolic function and oxygen and lactate consumption were assessed at base line, during CP, and after Langendorff blood reperfusion. Base line endothelial function was evaluated by the percentage transcoronary change ([coronary sinus - aorta]/aorta) in myeloperoxidase and by platelet function and coronary flow reserve after 20 seconds of coronary artery occlusion. During CP, the endothelium was assessed by transcoronary protein release and coronary resistance. Edema was assessed by weight gain and histology. Base line systolic and metabolic functions showed no relation to post-Langendorff function. Compared with CS, CP resulted in a greater recovery in systolic function (87% +/- 35% vs 65% +/- 15% of baseline; p = 0.05) and a shorter interval required for lactate consumption to exceed production (7.0 +/- 6.8 minutes vs 15.0 +/- 8.9 minutes; p = 0.06). Endothelial function was heterogeneous: coronary flow reserve, 2.7 +/- 0.7; percentage change in myeloperoxidase, -8.4% +/- 6.8%; and change in platelet function, 4.3% +/- 3.5%, as determined by thromboelastography angle at base line. Protein release during CP for 24 hours was 8.3 +/- 7.1 g. Two factors predicted more than 75% systolic pressure generation recovery: use of CP and normal endothelial function (p = 0.05; Fisher's exact test). However, CP led to edema according to histology, weight gain (72 +/- 29 g), and impaired diastolic function versus CS (end-diastolic pressure-volume relationship, 1.4 +/- 0.4 mm Hg/mL vs 0.8 +/- 0.3 mm Hg/mL; p = 0.08). Better systolic function despite 16 hours' more preservation than cold storage corroborates the idea that CP supports aerobic metabolism at physiologically important levels. Viability analysis focused on endothelial function and identified organs that were able to tolerate this 24-hour preservation interval.

Land change variability and human-environment dynamics in the United States Great Plains

USGS Publications Warehouse

Drummond, M.A.; Auch, Roger F.; Karstensen, K.A.; Sayler, K. L.; Taylor, Janis L.; Loveland, Thomas R.

2012-01-01

Land use and land cover changes have complex linkages to climate variability and change, biophysical resources, and socioeconomic driving forces. To assess these land change dynamics and their causes in the Great Plains, we compare and contrast contemporary changes across 16 ecoregions using Landsat satellite data and statistical analysis. Large-area change analysis of agricultural regions is often hampered by change detection error and the tendency for land conversions to occur at the local-scale. To facilitate a regional-scale analysis, a statistical sampling design of randomly selected 10 km × 10 km blocks is used to efficiently identify the types and rates of land conversions for four time intervals between 1973 and 2000, stratified by relatively homogenous ecoregions. Nearly 8% of the overall Great Plains region underwent land-use and land-cover change during the study period, with a substantial amount of ecoregion variability that ranged from less than 2% to greater than 13%. Agricultural land cover declined by more than 2% overall, with variability contingent on the differential characteristics of regional human–environment systems. A large part of the Great Plains is in relatively stable land cover. However, other land systems with significant biophysical and climate limitations for agriculture have high rates of land change when pushed by economic, policy, technology, or climate forcing factors. The results indicate the regionally based potential for land cover to persist or fluctuate as land uses are adapted to spatially and temporally variable forcing factors.

A micro-Raman spectroscopic investigation of leukemic U-937 cells in aged cultures

NASA Astrophysics Data System (ADS)

Fazio, Enza; Trusso, Sebastiano; Franco, Domenico; Nicolò, Marco Sebastiano; Allegra, Alessandro; Neri, Fortunato; Musolino, Caterina; Guglielmino, Salvatore P. P.

2016-04-01

Recently it has been shown that micro-Raman spectroscopy combined with multivariate analysis is able to discriminate among different types of tissues and tumoral cells by the detection of significant alterations and/or reorganizations of complex biological molecules, such as nucleic acids, lipids and proteins. Moreover, its use, being in principle a non-invasive technique, appears an interesting clinical tool for the evaluation of the therapeutical effects and of the disease progression. In this work we analyzed molecular changes in aged cultures of leukemia model U937 cells with respect to fresh cultures of the same cell line. In fact, structural variations of individual neoplastic cells on aging may lead to a heterogeneous data set, therefore falsifying confidence intervals, increasing error levels of analysis and consequently limiting the use of Raman spectroscopy analysis. We found that the observed morphological changes of U937 cells corresponded to well defined modifications of the Raman contributions in selected spectral regions, where markers of specific functional groups, useful to characterize the cell state, are present. A detailed subcellular analysis showed a change in cellular organization as a function of time, and correlated to a significant increase of apoptosis levels. Besides the aforementioned study, Raman spectra were used as input for principal component analysis (PCA) in order to detect and classify spectral changes among U937 cells.

Multi-component time, spatial and frequency analysis of Paleoclimatic Data

NASA Astrophysics Data System (ADS)

Cristiano, Luigia; Stampa, Johannes; Feeser, Ingo; Dörfler, Walter; Meier, Thomas

2017-04-01

The investigation of the paleoclimatic data offers a powerful tool for understanding the impact of extreme climatic events as well as gradual climatic variations on the human development and cultural changes. The current global record of paleoclimatic data is relatively rich but is not generally uniformly structured and regionally distributed. The general characteristic of the reconstructed time series of paleoclimatic data is a not constant sampling interval and data resolution together with the presence of gaps in the record. Our database consists of pollen concentration from annually laminated lake sediments in two sites in Northern Germany. Such data characteristic offers the possibility for high-resolution palynological and sedimentological analyses on a well constrained time scale. Specifically we are interested to investigate the time dependence of proxies, and time and spatial correlation of the different observables respect each other. We present here a quantitative analysis of the pollent data in the frequency and time. In particular we are interested to understand the complexity of the system and understand the cause of sudden as well as the slow changes in the time dependence of the observables. We show as well our approach for handling the not uniform sampling interval and the broad frequency content characterizing the paleoclimatic databases. In particular we worked to the development of a robust data analysis to answer the key questions about the correlation between rapid climatic changes and changes in the human habits and quantitatively elaborate a model for the processed data. Here we present the preliminary results on synthetics as well as on real data for the data visualization for the trend identification with a smoothing procedure, for the identification of sharp changes in the data as function of time with AutoRegressive approach. In addition to that we use the cross-correlation and cross spectrum by applying the Multiple Filtering Technique(MFT) of different pollen data from same location and same pollen data from different locations to identify the short and long period terms and to quantify the similarities in time and frequency domain.

Different target-discrimination times can be followed by the same saccade-initiation timing in different stimulus conditions during visual searches

PubMed Central

Tanaka, Tomohiro; Nishida, Satoshi

2015-01-01

The neuronal processes that underlie visual searches can be divided into two stages: target discrimination and saccade preparation/generation. This predicts that the length of time of the prediscrimination stage varies according to the search difficulty across different stimulus conditions, whereas the length of the latter postdiscrimination stage is stimulus invariant. However, recent studies have suggested that the length of the postdiscrimination interval changes with different stimulus conditions. To address whether and how the visual stimulus affects determination of the postdiscrimination interval, we recorded single-neuron activity in the lateral intraparietal area (LIP) when monkeys (Macaca fuscata) performed a color-singleton search involving four stimulus conditions that differed regarding luminance (Bright vs. Dim) and target-distractor color similarity (Easy vs. Difficult). We specifically focused on comparing activities between the Bright-Difficult and Dim-Easy conditions, in which the visual stimuli were considerably different, but the mean reaction times were indistinguishable. This allowed us to examine the neuronal activity when the difference in the degree of search speed between different stimulus conditions was minimal. We found that not only prediscrimination but also postdiscrimination intervals varied across stimulus conditions: the postdiscrimination interval was longer in the Dim-Easy condition than in the Bright-Difficult condition. Further analysis revealed that the postdiscrimination interval might vary with stimulus luminance. A computer simulation using an accumulation-to-threshold model suggested that the luminance-related difference in visual response strength at discrimination time could be the cause of different postdiscrimination intervals. PMID:25995344

Acupuncture for the sequelae of Bell's palsy: a randomized controlled trial.

PubMed

Kwon, Hyo-Jung; Choi, Jun-Yong; Lee, Myeong Soo; Kim, Yong-Suk; Shin, Byung-Cheul; Kim, Jong-In

2015-06-03

Incomplete recovery from facial palsy results in social and physical disabilities, and the medical options for the sequelae of Bell's palsy are limited. Acupuncture is widely used for Bell's palsy patients in East Asia, but its efficacy is unclear. We performed a randomized controlled trial including participants with the sequelae of Bell's palsy with the following two parallel arms: an acupuncture group (n = 26) and a waiting list group (n = 13). The acupuncture group received acupuncture treatments for 8 weeks, whereas the waiting list group did not receive acupuncture treatments during the 8-week period after randomization. The primary outcome measure was change in the Facial Disability Index (FDI) social and well-being subscale at week 8. We also analyzed changes in the FDI physical function subscale, the House-Brackmann score, the Sunnybrook Facial Nerve Grading system, lip mobility and stiffness at 5 and 8 weeks after randomization. An intention-to-treat analysis was applied. The acupuncture group exhibited greater improvements in the FDI social score (mean difference, 23.54; 95% confidence interval, 12.99 to 34.08) and better results on the FDI physical function subscale (mean difference, 21.54; 95% confidence interval, 7.62 to 35.46), Sunnybrook Facial Nerve Grading score (mean difference, 14.77; 95% confidence interval, 5.05 to 24.49), and stiffness scale (mean difference, -1.58; 95% confidence interval,-2.26 to -0.89) compared with the waiting list group after 8 weeks. No severe adverse event occurred in either group. Compared with the waiting list group, acupuncture had better therapeutic effects on the social and physical aspects of sequelae of Bell's palsy. Current Controlled Trials ISRCTN43104115.

Lacosamide cardiac safety: clinical trials in patients with partial-onset seizures.

PubMed

Rudd, G D; Haverkamp, W; Mason, J W; Wenger, T; Jay, G; Hebert, D; Doty, P; Horstmann, R

2015-11-01

To evaluate the cardiac safety of adjunctive lacosamide in a large pool of adults with partial-onset seizures (POS). Post-randomization changes from baseline for electrocardiographic (ECG) measurements, diagnostic findings, and relevant adverse events (AEs) were compared for pooled data from three randomized, placebo-controlled trials of adjunctive lacosamide for the treatment of POS. Lacosamide did not prolong the QTc interval or affect heart rate as determined by an analysis of data from patients randomized to lacosamide 200, 400, or 600 mg/day (n = 944) compared with placebo (n = 364). After 12-week maintenance treatment, mean changes from baseline for QRS duration were similar between the placebo and lacosamide 200 and 400 mg/day groups (0.0, -0.2, and 0.4 ms), but slightly increased for lacosamide 600 mg/day (2.3 ms). A small, dose-related mean increase in PR interval was observed (-0.3, 1.4, 4.4, and 6.6 ms for the placebo and lacosamide 200, 400, and 600 mg/day groups, respectively). First-degree atrioventricular (AV) block was reported as a non-serious AE in 0.0%, 0.7%, 0.2%, and 0.5% of patients in the same respective groups. Second- or higher degree AV block was not observed. There was no evidence of a PR-interval-related pharmacodynamic interaction of lacosamide with either carbamazepine or lamotrigine. Evaluation of the pooled cardiac safety data from patients with POS showed that adjunctive lacosamide at the maximum recommended dose (400 mg/day) was not clearly associated with any cardiac effect other than a small, dose-related increase in PR interval that had no evident symptomatic consequence. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Clinical Outcomes of Transplanted Modified Bone Marrow-Derived Mesenchymal Stem Cells in Stroke: A Phase 1/2a Study.

PubMed

Steinberg, Gary K; Kondziolka, Douglas; Wechsler, Lawrence R; Lunsford, L Dade; Coburn, Maria L; Billigen, Julia B; Kim, Anthony S; Johnson, Jeremiah N; Bates, Damien; King, Bill; Case, Casey; McGrogan, Michael; Yankee, Ernest W; Schwartz, Neil E

2016-07-01

Preclinical data suggest that cell-based therapies have the potential to improve stroke outcomes. Eighteen patients with stable, chronic stroke were enrolled in a 2-year, open-label, single-arm study to evaluate the safety and clinical outcomes of surgical transplantation of modified bone marrow-derived mesenchymal stem cells (SB623). All patients in the safety population (N=18) experienced at least 1 treatment-emergent adverse event. Six patients experienced 6 serious treatment-emergent adverse events; 2 were probably or definitely related to surgical procedure; none were related to cell treatment. All serious treatment-emergent adverse events resolved without sequelae. There were no dose-limiting toxicities or deaths. Sixteen patients completed 12 months of follow-up at the time of this analysis. Significant improvement from baseline (mean) was reported for: (1) European Stroke Scale: mean increase 6.88 (95% confidence interval, 3.5-10.3; P<0.001), (2) National Institutes of Health Stroke Scale: mean decrease 2.00 (95% confidence interval, -2.7 to -1.3; P<0.001), (3) Fugl-Meyer total score: mean increase 19.20 (95% confidence interval, 11.4-27.0; P<0.001), and (4) Fugl-Meyer motor function total score: mean increase 11.40 (95% confidence interval, 4.6-18.2; P<0.001). No changes were observed in modified Rankin Scale. The area of magnetic resonance T2 fluid-attenuated inversion recovery signal change in the ipsilateral cortex 1 week after implantation significantly correlated with clinical improvement at 12 months (P<0.001 for European Stroke Scale). In this interim report, SB623 cells were safe and associated with improvement in clinical outcome end points at 12 months. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01287936. © 2016 American Heart Association, Inc.

Automated electronic monitoring of circuit pressures during continuous renal replacement therapy: a technical report.

PubMed

Zhang, Ling; Baldwin, Ian; Zhu, Guijun; Tanaka, Aiko; Bellomo, Rinaldo

2015-03-01

Automated electronic monitoring and analysis of circuit pressures during continuous renal replacement therapy (CRRT) has the potential to predict failure and allow intervention to optimise function. Current CRRT machines can measure and store pressure readings for downloading into databases and for analysis. We developed a procedure to obtain such data at intervals of 1 minute and analyse them using the Prismaflex CRRT machine, and we present an example of such analysis. We obtained data on pressures obtained at intervals of 1 minute in a patient with acute kidney injury and sepsis treated with continuous haemofiltration at 2 L/hour of ultrafiltration and a blood flow of 200 mL/minute. Data analysis identified progressive increases in transmembrane pressure (TMP) and prefilter pressure (PFP) from time 0 until 33 hours or clotting. TMP increased from 104 mmHg to 313 mmHg and PFP increased from from 131 mmHg to 185 mmHg. Effluent pressure showed a progressive increase in the negative pressure applied to achieve ultrafiltration from 0 mmHg to -168 mmHg. The inflection point for such changes was also identified. Blood pathway pressures for access and return remained unchanged throughout. Automated electronic monitoring of circuit pressure during CRRT is possible and provides useful information on the evolution of circuit clotting.

Pulsation of late B-type stars

NASA Technical Reports Server (NTRS)

Beardsley, W. R.; Worek, T. F.; King, M. W.

1980-01-01

Radial velocity observations of three of the brightest stars in the Pleiades, Alcyone, Maia and Taygeta, made during the course of one night, 25 October 1976, are discussed. All three stars were discovered to be pulsating with periods of a few hours. Analysis of all published radial velocities for each star, covering more than 70 years and approximately 100,000 cycles, has established the value of the periods to eight decimal places, and demonstrated constancy of the periods. However, amplitudes of the radial velocity variations change over long time intervals, and changes in spectral line intensities are observed in phase with the pulsation. All three stars may also be members of binary systems.

Age-specific MRI templates for pediatric neuroimaging

PubMed Central

Sanchez, Carmen E.; Richards, John E.; Almli, C. Robert

2012-01-01

This study created a database of pediatric age-specific MRI brain templates for normalization and segmentation. Participants included children from 4.5 through 19.5 years, totaling 823 scans from 494 subjects. Open-source processing programs (FSL, SPM, ANTS) constructed head, brain and segmentation templates in 6 month intervals. The tissue classification (WM, GM, CSF) showed changes over age similar to previous reports. A volumetric analysis of age-related changes in WM and GM based on these templates showed expected increase/decrease pattern in GM and an increase in WM over the sampled ages. This database is available for use for neuroimaging studies (blindedforreview). PMID:22799759

Changes in the saltwater interface corresponding to the installation of a seepage barrier near Lake Okeechobee, Florida

USGS Publications Warehouse

Prinos, Scott T.; Valderrama, Robert

2015-01-01

At five of the monitoring-well cluster locations, a long-screened well was also installed for monitoring and comparison purposes. These long-screened wells are 160 to 200 ft deep, and have open intervals ranging from 145 to 185 ft in length. Water samples were collected at depth intervals of about 5 to 10 ft, using 3-ft-long straddle packers to isolate each sampling interval. The results of monitoring conducted using these long-screened interval wells were generally too variable to identify any changes that might be associated with the seepage barrier. Samples from one of these long-screened interval wells failed to detect the saltwater interface evident in samples and TSEMIL datasets from a collocated well cluster. This failure may have been caused by downward flow of freshwater from above the saltwater interface in the well bore.

Recurrence interval analysis of trading volumes

NASA Astrophysics Data System (ADS)

Ren, Fei; Zhou, Wei-Xing

2010-06-01

We study the statistical properties of the recurrence intervals τ between successive trading volumes exceeding a certain threshold q . The recurrence interval analysis is carried out for the 20 liquid Chinese stocks covering a period from January 2000 to May 2009, and two Chinese indices from January 2003 to April 2009. Similar to the recurrence interval distribution of the price returns, the tail of the recurrence interval distribution of the trading volumes follows a power-law scaling, and the results are verified by the goodness-of-fit tests using the Kolmogorov-Smirnov (KS) statistic, the weighted KS statistic and the Cramér-von Mises criterion. The measurements of the conditional probability distribution and the detrended fluctuation function show that both short-term and long-term memory effects exist in the recurrence intervals between trading volumes. We further study the relationship between trading volumes and price returns based on the recurrence interval analysis method. It is found that large trading volumes are more likely to occur following large price returns, and the comovement between trading volumes and price returns is more pronounced for large trading volumes.

Recurrence interval analysis of trading volumes.

PubMed

Ren, Fei; Zhou, Wei-Xing

2010-06-01

We study the statistical properties of the recurrence intervals τ between successive trading volumes exceeding a certain threshold q. The recurrence interval analysis is carried out for the 20 liquid Chinese stocks covering a period from January 2000 to May 2009, and two Chinese indices from January 2003 to April 2009. Similar to the recurrence interval distribution of the price returns, the tail of the recurrence interval distribution of the trading volumes follows a power-law scaling, and the results are verified by the goodness-of-fit tests using the Kolmogorov-Smirnov (KS) statistic, the weighted KS statistic and the Cramér-von Mises criterion. The measurements of the conditional probability distribution and the detrended fluctuation function show that both short-term and long-term memory effects exist in the recurrence intervals between trading volumes. We further study the relationship between trading volumes and price returns based on the recurrence interval analysis method. It is found that large trading volumes are more likely to occur following large price returns, and the comovement between trading volumes and price returns is more pronounced for large trading volumes.

Characterization of Myocardial Repolarization Reserve in Adolescent Females With Anorexia Nervosa.

PubMed

Padfield, Gareth J; Escudero, Carolina A; DeSouza, Astrid M; Steinberg, Christian; Gibbs, Karen; Puyat, Joseph H; Lam, Pei Yoong; Sanatani, Shubhayan; Sherwin, Elizabeth; Potts, James E; Sandor, George; Krahn, Andrew D

2016-02-09

Patients with anorexia nervosa exhibit abnormal myocardial repolarization and are susceptible to sudden cardiac death. Exercise testing is useful in unmasking QT prolongation in disorders associated with abnormal repolarization. We characterized QT adaptation during exercise in anorexia. Sixty-one adolescent female patients with anorexia nervosa and 45 age- and sex-matched healthy volunteers performed symptom-limited cycle ergometry during 12-lead ECG monitoring. Changes in the QT interval during exercise were measured, and QT/RR-interval slopes were determined by using mixed-effects regression modeling. Patients had significantly lower body mass index than controls; however, resting heart rates and QT/QTc intervals were similar at baseline. Patients had shorter exercise times (13.7±4.5 versus 20.6±4.5 minutes; P<0.001) and lower peak heart rates (159±20 versus 184±9 beats/min; P<0.001). The mean QTc intervals were longer at peak exercise in patients (442±29 versus 422±19 ms; P<0.001). During submaximal exertion at comparable heart rates (114±6 versus 115±11 beats/min; P=0.54), the QTc interval had prolonged significantly more in patients than controls (37±28 versus 24±25 ms; P<0.016). The RR/QT slope, best described by a curvilinear relationship, was more gradual in patients than in controls (13.4; 95% confidence interval, 12.8-13.9 versus 15.8; 95% confidence interval, 15.3-16.4 ms QT change per 10% change in RR interval; P<0.001) and steepest in patients within the highest body mass index tertile versus the lowest (13.9; 95% confidence interval, 12.9-14.9 versus 12.3; 95% confidence interval, 11.3-13.3; P=0.026). Despite the absence of manifest QT prolongation, adolescent anorexic females have impaired repolarization reserve in comparison with healthy controls. Further study may identify impaired QT dynamics as a risk factor for arrhythmias in anorexia nervosa. © 2016 American Heart Association, Inc.

On the Modeling of the Residual Effects of the Clock Behavior and the Atmosphere Effects in the Analysis of VLBI Data

NASA Astrophysics Data System (ADS)

Bo, Zhang; Li, Jin-Ling; Wang, Guan-Gli

2002-01-01

We checked the dependence of the estimation of parameters on the choice of piecewise interval in the continuous piecewise linear modeling of the residual clock and atmosphere effects by single analysis of 27 VLBI experiments involving Shanghai station (Seshan 25m). The following are tentatively shown: (1) Different choices of the piecewise interval lead to differences in the estimation of station coordinates and in the weighted root mean squares ( wrms ) of the delay residuals, which can be of the order of centimeters or dozens of picoseconds respectively. So the choice of piecewise interval should not be arbitrary . (2) The piecewise interval should not be too long, otherwise the short - term variations in the residual clock and atmospheric effects can not be properly modeled. While in order to maintain enough degrees of freedom in parameter estimation, the interval can not be too short, otherwise the normal equation may become near or solely singular and the noises can not be constrained as well. Therefore the choice of the interval should be within some reasonable range. (3) Since the conditions of clock and atmosphere are different from experiment to experiment and from station to station, the reasonable range of the piecewise interval should be tested and chosen separately for each experiment as well as for each station by real data analysis. This is really arduous work in routine data analysis. (4) Generally speaking, with the default interval for clock as 60min, the reasonable range of piecewise interval for residual atmospheric effect modeling is between 10min to 40min, while with the default interval for atmosphere as 20min, that for residual clock behavior is between 20min to 100min.

Advanced Interval Management: A Benefit Analysis

NASA Technical Reports Server (NTRS)

Timer, Sebastian; Peters, Mark

2016-01-01

This document is the final report for the NASA Langley Research Center (LaRC)- sponsored task order 'Possible Benefits for Advanced Interval Management Operations.' Under this research project, Architecture Technology Corporation performed an analysis to determine the maximum potential benefit to be gained if specific Advanced Interval Management (AIM) operations were implemented in the National Airspace System (NAS). The motivation for this research is to guide NASA decision-making on which Interval Management (IM) applications offer the most potential benefit and warrant further research.

The stability of IQ in people with low intellectual ability: an analysis of the literature.

PubMed

Whitaker, Simon

2008-04-01

A meta-analysis of the stability of low IQ (IQ < 80) was performed on IQ tests that have been commonly used--tests that were derived by D. Wechsler (1949, 1955, 1974, 1981, 1991, 1997) and those based on the Binet scales (L. M. Terman, 1960; L. M. Terman & Merrill, 1972). Weighted-mean stability coefficients of .77 and .78 were found for Verbal IQ (V IQ) and Performance IQ (P IQ) on the Wechsler tests and .82 for Full-Scale IQ (FS IQ) on both Wechsler and Binet tests, for a mean test-retest interval of 2.8 years. Although the majority of FS IQs changed by less than 6 points, 14% changed by 10 points or more. The author suggests that the results of IQ assessment should be treated with more caution than previously thought.

A Two-Stage Method to Determine Optimal Product Sampling considering Dynamic Potential Market

PubMed Central

Hu, Zhineng; Lu, Wei; Han, Bing

2015-01-01

This paper develops an optimization model for the diffusion effects of free samples under dynamic changes in potential market based on the characteristics of independent product and presents a two-stage method to figure out the sampling level. The impact analysis of the key factors on the sampling level shows that the increase of the external coefficient or internal coefficient has a negative influence on the sampling level. And the changing rate of the potential market has no significant influence on the sampling level whereas the repeat purchase has a positive one. Using logistic analysis and regression analysis, the global sensitivity analysis gives a whole analysis of the interaction of all parameters, which provides a two-stage method to estimate the impact of the relevant parameters in the case of inaccuracy of the parameters and to be able to construct a 95% confidence interval for the predicted sampling level. Finally, the paper provides the operational steps to improve the accuracy of the parameter estimation and an innovational way to estimate the sampling level. PMID:25821847

Estimating short-run and long-run interaction mechanisms in interictal state.

PubMed

Ozkaya, Ata; Korürek, Mehmet

2010-04-01

We address the issue of analyzing electroencephalogram (EEG) from seizure patients in order to test, model and determine the statistical properties that distinguish between EEG states (interictal, pre-ictal, ictal) by introducing a new class of time series analysis methods. In the present study: firstly, we employ statistical methods to determine the non-stationary behavior of focal interictal epileptiform series within very short time intervals; secondly, for such intervals that are deemed non-stationary we suggest the concept of Autoregressive Integrated Moving Average (ARIMA) process modelling, well known in time series analysis. We finally address the queries of causal relationships between epileptic states and between brain areas during epileptiform activity. We estimate the interaction between different EEG series (channels) in short time intervals by performing Granger-causality analysis and also estimate such interaction in long time intervals by employing Cointegration analysis, both analysis methods are well-known in econometrics. Here we find: first, that the causal relationship between neuronal assemblies can be identified according to the duration and the direction of their possible mutual influences; second, that although the estimated bidirectional causality in short time intervals yields that the neuronal ensembles positively affect each other, in long time intervals neither of them is affected (increasing amplitudes) from this relationship. Moreover, Cointegration analysis of the EEG series enables us to identify whether there is a causal link from the interictal state to ictal state.

The use of heart rate variability in assessing precompetitive stress in high-standard judo athletes.

PubMed

Morales, J; Garcia, V; García-Massó, X; Salvá, P; Escobar, R; Buscà, B

2013-02-01

The objective of this study is to examine the sensitivity to and changes in heart rate variability (HRV) in stressful situations before judo competitions and to observe the differences among judo athletes according to their competitive standards in both official and unofficial competitions. 24 (10 male and 14 female) national- and international-standard athletes were evaluated. Each participant answered the Revised Competitive State Anxiety Inventory (CSAI-2R) and their HRV was recorded both during an official and unofficial competition. The MANOVA showed significant main effects of the athlete's standard and the type of competition in CSAI-2R, in HRV time domain, in HRV frequency domain and in HRV nonlinear analysis (p<0.05). International-standard judo athletes have lower somatic anxiety, cognitive anxiety, heart rate and low-high frequency ratio than national-standard athletes (p<0.05). International-standard athletes have a higher confidence, mean RR interval, standard deviation of RR, square root of the mean squared difference of successive RR intervals, number of consecutive RR that differ by more than 5 ms, short-term variability, long-term variability, long-range scaling exponents and short-range scaling exponent than national-standard judo athletes. In conclusion, international-standard athletes show less pre-competitive anxiety than the national-standard athletes and HRV analysis is sensitive to changes in pre-competitive anxiety. © Georg Thieme Verlag KG Stuttgart · New York.

Cluster analysis of quantitative parametric maps from DCE-MRI: application in evaluating heterogeneity of tumor response to antiangiogenic treatment.

PubMed

Longo, Dario Livio; Dastrù, Walter; Consolino, Lorena; Espak, Miklos; Arigoni, Maddalena; Cavallo, Federica; Aime, Silvio

2015-07-01

The objective of this study was to compare a clustering approach to conventional analysis methods for assessing changes in pharmacokinetic parameters obtained from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) during antiangiogenic treatment in a breast cancer model. BALB/c mice bearing established transplantable her2+ tumors were treated with a DNA-based antiangiogenic vaccine or with an empty plasmid (untreated group). DCE-MRI was carried out by administering a dose of 0.05 mmol/kg of Gadocoletic acid trisodium salt, a Gd-based blood pool contrast agent (CA) at 1T. Changes in pharmacokinetic estimates (K(trans) and vp) in a nine-day interval were compared between treated and untreated groups on a voxel-by-voxel analysis. The tumor response to therapy was assessed by a clustering approach and compared with conventional summary statistics, with sub-regions analysis and with histogram analysis. Both the K(trans) and vp estimates, following blood-pool CA injection, showed marked and spatial heterogeneous changes with antiangiogenic treatment. Averaged values for the whole tumor region, as well as from the rim/core sub-regions analysis were unable to assess the antiangiogenic response. Histogram analysis resulted in significant changes only in the vp estimates (p<0.05). The proposed clustering approach depicted marked changes in both the K(trans) and vp estimates, with significant spatial heterogeneity in vp maps in response to treatment (p<0.05), provided that DCE-MRI data are properly clustered in three or four sub-regions. This study demonstrated the value of cluster analysis applied to pharmacokinetic DCE-MRI parametric maps for assessing tumor response to antiangiogenic therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Changes in corneal astigmatism during 20 years after cataract surgery.

PubMed

Hayashi, Ken; Manabe, Shin-Ichi; Hirata, Akira; Yoshimura, Koichi

2017-05-01

To examine how corneal astigmatism changes with age over 20 years after cataract surgery and to assess whether the changes differ from those in eyes that did not have surgery. Hayashi Eye Hospital, Fukuoka, Japan. Retrospective case study. Using an autokeratometer, corneal astigmatism was measured preoperatively, at baseline (the day the surgically induced astigmatism stabilized), and 10 years and 20 years after baseline. The change in corneal astigmatism between baseline and 10 years, 10 years and 20 years, and baseline and 20 years was determined using power vector analysis and compared between the time intervals and between groups. The study assessed 74 eyes that had phacoemulsification with a horizontal scleral incision more than 21 years ago (surgery group) and 68 eyes that did not have surgery (no-surgery group). The mean vertical/horizontal change in corneal astigmatism (J0) between baseline and 20 years was -0.64 diopter (D) in the surgery group and -0.49 D in the no-surgery group. The oblique change (J45) was -0.03 D in the surgery group and 0.07 D in the no-surgery group. Using multivariate comparison, the mean J0 and J45 values were not significantly different between baseline and 10 years or between 10 years and 20 years in both groups (P ≥ .2350). The J0 and J45 values were not significantly different between the 2 groups at any time interval (P ≥ .1331). Corneal astigmatism continues to change toward against-the-rule astigmatism over 20 years after cataract surgery. This change was similar in eyes that did not have surgery. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Measuring the success of combined intravesical dimethyl sulfoxide and triamcinolone for treatment of bladder pain syndrome/interstitial cystitis.

PubMed

Gafni-Kane, Adam; Botros, Sylvia M; Du, Hongyan; Sand, Robert I; Sand, Peter K

2013-02-01

The purpose of this study was to investigate change in bladder capacity as a measure of response to combined intravesical dimethyl sulfoxide (DMSO) and triamcinolone instillations for the treatment of newly diagnosed bladder pain syndrome/interstitial cystitis (BPS/IC). 141 newly diagnosed women were identified retrospectively. 79 were treated with weekly DMSO/triamcinolone instillations. Change in bladder capacity with bladder retrofill, daytime urinary frequency, nocturia episodes per night, and Likert scale symptom scores were reviewed. Wilcoxon signed-rank tests, Wilcoxon rank-sum tests, Spearman's rank correlations, COX regression analysis, and a Kaplan-Meier survival curve were performed. Significant changes (median (25(th)-percentile to 75(th)-percentile) were noted for bladder capacity (75 mL (25 to 130 mL), p < 0.0001), inter-void interval (0 hrs (0 to 1 hour), p < 0.0001), nocturia episodes per night (-1 (-2 to 0), p < 0.0001), and aggregate Likert symptom scores (-2 points (-5 to 0), p < 0.0001). Percent change in bladder capacity correlated positively with percent change in inter-void interval (p = 0.03) and negatively with percent changes in nocturia (p = 0.17) and symptom scores (p = 0.01). Women without detrusor overactivity (DO) had greater percent changes in capacity than women with DO (62.5 % vs. 16.5 %, p = 0.02). 61.3 % of patients were retreated with a 36 weeks median time to retreatment and no difference in time to retreatment based upon DO. Greater capacity was protective against retreatment (hazard ratio = 0.997 [95 % CI 0.994,0.999], p = 0.02). Percent change in bladder capacity is a useful objective measure of response to intravesical DMSO/triamcinolone for newly diagnosed BPS/IC. Clinical outcomes do not differ based upon presence of DO.

Bayesian Statistical Analysis of Historical and Late Holocene Rates of Sea-Level Change

NASA Astrophysics Data System (ADS)

Cahill, Niamh; Parnell, Andrew; Kemp, Andrew; Horton, Benjamin

2014-05-01

A fundamental concern associated with climate change is the rate at which sea levels are rising. Studies of past sea level (particularly beyond the instrumental data range) allow modern sea-level rise to be placed in a more complete context. Considering this, we perform a Bayesian statistical analysis on historical and late Holocene rates of sea-level change. The data that form the input to the statistical model are tide-gauge measurements and proxy reconstructions from cores of coastal sediment. The aims are to estimate rates of sea-level rise, to determine when modern rates of sea-level rise began and to observe how these rates have been changing over time. Many of the current methods for doing this use simple linear regression to estimate rates. This is often inappropriate as it is too rigid and it can ignore uncertainties that arise as part of the data collection exercise. This can lead to over confidence in the sea-level trends being characterized. The proposed Bayesian model places a Gaussian process prior on the rate process (i.e. the process that determines how rates of sea-level are changing over time). The likelihood of the observed data is the integral of this process. When dealing with proxy reconstructions, this is set in an errors-in-variables framework so as to take account of age uncertainty. It is also necessary, in this case, for the model to account for glacio-isostatic adjustment, which introduces a covariance between individual age and sea-level observations. This method provides a flexible fit and it allows for the direct estimation of the rate process with full consideration of all sources of uncertainty. Analysis of tide-gauge datasets and proxy reconstructions in this way means that changing rates of sea level can be estimated more comprehensively and accurately than previously possible. The model captures the continuous and dynamic evolution of sea-level change and results show that not only are modern sea levels rising but that the rates of rise are continuously increasing. Analysis of the a global tide-gauge record (Church and White, 2011) indicated that the rate of sea-level rise increased continuously since 1880AD and is currently 2.57mm/yr (95% credible interval of 1.71 to 4.35mm/yr). Application of the model a proxy reconstruction from North Carolina (Kemp et al., 2011) indicated that the mean rate of rise in this locality since the middle of the 19th century (current rate of 2.66 mm/yr with a 95% credible interval of 1.29 to 4.59mm/yr) is in agreement with results from the tide gauge analysis and is unprecedented in at least the last 2000 years.

Changes in the PQRST intervals and heart rate variability associated with rewarming in two newborns undergoing hypothermia therapy.

PubMed

Lasky, Robert E; Parikh, Nehal A; Williams, Amber L; Padhye, Nikhil S; Shankaran, Seetha

2009-01-01

Little is known about the effects of hypothermia therapy and subsequent rewarming on the PQRST intervals and heart rate variability (HRV) in term newborns with hypoxic-ischemic encephalopathy (HIE). This study describes the changes in the PQRST intervals and HRV during rewarming to normal core body temperature of 2 newborns with HIE after hypothermia therapy. Within 6 h after birth, 2 newborns with HIE were cooled to a core body temperature of 33.5 degrees C for 72 h using a cooling blanket, followed by gradual rewarming (0.5 degrees C per hour) until the body temperature reached 36.5 degrees C. Custom instrumentation recorded the electrocardiogram from the leads used for clinical monitoring of vital signs. Generalized linear mixed models were calculated to estimate temperature-related changes in PQRST intervals and HRV. For every 1 degrees C increase in body temperature, the heart rate increased by 9.2 bpm (95% CI 6.8-11.6), the QTc interval decreased by 21.6 ms (95% CI 17.3-25.9), and low and high frequency HRV decreased by 0.480 dB (95% CI 0.052-0.907) and 0.938 dB (95% CI 0.460-1.416), respectively. Hypothermia-induced changes in the electrocardiogram should be monitored carefully in future studies. Copyright 2009 S. Karger AG, Basel.

Background music as a quasi clock in retrospective duration judgments.

PubMed

Bailey, Nicole; Areni, Charles S

2006-04-01

The segmentation-change model of time perception proposes that individuals engaged in cognitive tasks during a given interval of time retrospectively estimate duration by recalling events that occurred during the interval and inferring each event's duration. Previous research suggests that individuals can recall the number of songs heard during an interval and infer the length of each song, exactly the conditions that foster estimates of duration based on the segmentation-change model. The results of a laboratory experiment indicated that subjects who solved word-search puzzles for 20 min. estimated the duration of the interval to be longer when 8 short songs (<3 min.) as opposed to 4 long songs (6+ min.) were played in the background, regardless of whether the musical format was Contemporary Dance or New Age. Assuming each song represented a distinct segment in memory, these results are consistent with the segmentation-change model. These results suggest that background music may not always reduce estimates of duration by drawing attention away from the passage of time. Instead, background music may actually expand the subjective length of an interval by creating accessible traces in memory, which are retrospectively used to infer duration.

Factors influencing general practitioners' decisions about cardiovascular disease risk reassessment: findings from experimental and interview studies.

PubMed

McKinn, Shannon; Bonner, Carissa; Jansen, Jesse; Teixeira-Pinto, Armando; So, Matthew; Irwig, Les; Doust, Jenny; Glasziou, Paul; McCaffery, Kirsten

2016-08-05

Guidelines on cardiovascular disease (CVD) risk reassessment intervals are unclear, potentially leading to detrimental practice variation: too frequent can result in overtreatment and greater strain on the healthcare system; too infrequent could result in the neglect of high risk patients who require medication. This study aimed to understand the different factors that general practitioners (GPs) consider when deciding on the reassessment interval for patients previously assessed for primary CVD risk. This paper combines quantitative and qualitative data regarding reassessment intervals from two separate studies of CVD risk management. Experimental study: 144 Australian GPs viewed a random selection of hypothetical cases via a paper-based questionnaire, in which blood pressure, cholesterol and 5-year absolute risk (AR) were systematically varied to appear lower or higher. GPs were asked how they would manage each case, including an open-ended response for when they would reassess the patient. Interview study: Semi-structured interviews were conducted with a purposive sample of 25 Australian GPs, recruited separately from the GPs in the experimental study. Transcribed audio-recordings were thematically coded, using the Framework Analysis method. GPs stated that they would reassess the majority of patients across all absolute risk categories in 6 months or less (low AR = 52 % [CI95% = 47-57 %], moderate AR = 82 % [CI95% = 76-86 %], high AR = 87 % [CI95% = 82-90 %], total = 71 % [CI95% = 67-75 %]), with 48 % (CI95% = 43-53 %) of patients reassessed in under 3 months. The majority (75 % [CI95% = 70-79 %]) of patients with low-moderate AR (≤15 %) and an elevated risk factor would be reassessed in under 6 months. Interviews: GPs identified different functions for reassessment and risk factor monitoring, which affected recommended intervals. These included perceived psychosocial benefits to patients, preparing the patient for medication, and identifying barriers to lifestyle change and medication adherence. Reassessment and monitoring intervals were driven by patient motivation to change lifestyle, patient demand, individual risk factors, and GP attitudes. There is substantial variation in reassessment intervals for patients with the same risk profile. This suggests that GPs are not following reassessment recommendations in the Australian guidelines. The use of shorter intervals for low-moderate AR contradicts research on optimal monitoring intervals, and may result in unnecessary costs and over-treatment.

Bottom-water oxygenation and environmental change in Santa Monica Basin, southern California during the last 22 kyr

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

Balestra, Barbara; Krupinksi, Nadine Quintana; Erhoina, Tzvetina

The Southern California Borderland (SCB) is a region that experiences strong natural variations in bottom water oxygen and pH. Here, we use marine sediments from the Santa Monica Basin (SMB) to reconstruct environmental conditions and changes in the basin's bottom water oxygenation from the Last Glacial Maximum (LGM) to present, and compare the records to the adjacent Santa Barbara Basin (SBB) and Santa Lucia Slope (SLS). High-resolution records of benthic foraminiferal oxygen and carbon isotopes (δ 18O and δ 13C), benthic foraminiferal assemblages, and bulk sedimentary organic matter geochemistry records exhibit major changes associated with late Quaternary millennial-scale global climatemore » oscillations. Our data show the dominance of low-oxygen benthic foraminifera assemblages during warm intervals, and assemblages representing higher dissolved oxygen during cooler intervals, as also seen in SBB and SLS. But, our record shows a stronger and longer-lasting oxygen minimum zone (OMZ) between the end of the Bølling-Allerød (B-A) and the Early Holocene (including the Younger Dryas) than at neighboring sites, indicated by dominance of Bolivina tumida (characteristic of major hypoxia) in the assemblage. The middle to late Holocene (from ~ 8.8 to 0 ka) had weaker hypoxia than the early Holocene, with assemblages mainly composed of Bolivina argentea and Uvigerina peregrina. The SMB remains mostly slightly low in oxygen throughout the studied interval, with differences in the degree of hypoxia relative to SBB and SLS (especially from the B-A to the Early Holocene) likely due to its greater depth and its more southern geographic position and therefore decreased exposure to North Pacific Intermediate Water current. Regional effects, such as changing intermediate water source and/or changing ventilation (oxygenation) of the intermediate water source, also affect SMB deep water. Our analysis utilizing parallel geochemical and micropaleontological records brings new insights into bottom water and climate conditions in SMB, indicating regional similarities and differences with adjacent basins, and provides insight into the causes for changes in bottom water oxygenation.« less

Bottom-water oxygenation and environmental change in Santa Monica Basin, southern California during the last 22 kyr

DOE PAGES

Balestra, Barbara; Krupinksi, Nadine Quintana; Erhoina, Tzvetina; ...

2017-09-29

The Southern California Borderland (SCB) is a region that experiences strong natural variations in bottom water oxygen and pH. Here, we use marine sediments from the Santa Monica Basin (SMB) to reconstruct environmental conditions and changes in the basin's bottom water oxygenation from the Last Glacial Maximum (LGM) to present, and compare the records to the adjacent Santa Barbara Basin (SBB) and Santa Lucia Slope (SLS). High-resolution records of benthic foraminiferal oxygen and carbon isotopes (δ 18O and δ 13C), benthic foraminiferal assemblages, and bulk sedimentary organic matter geochemistry records exhibit major changes associated with late Quaternary millennial-scale global climatemore » oscillations. Our data show the dominance of low-oxygen benthic foraminifera assemblages during warm intervals, and assemblages representing higher dissolved oxygen during cooler intervals, as also seen in SBB and SLS. But, our record shows a stronger and longer-lasting oxygen minimum zone (OMZ) between the end of the Bølling-Allerød (B-A) and the Early Holocene (including the Younger Dryas) than at neighboring sites, indicated by dominance of Bolivina tumida (characteristic of major hypoxia) in the assemblage. The middle to late Holocene (from ~ 8.8 to 0 ka) had weaker hypoxia than the early Holocene, with assemblages mainly composed of Bolivina argentea and Uvigerina peregrina. The SMB remains mostly slightly low in oxygen throughout the studied interval, with differences in the degree of hypoxia relative to SBB and SLS (especially from the B-A to the Early Holocene) likely due to its greater depth and its more southern geographic position and therefore decreased exposure to North Pacific Intermediate Water current. Regional effects, such as changing intermediate water source and/or changing ventilation (oxygenation) of the intermediate water source, also affect SMB deep water. Our analysis utilizing parallel geochemical and micropaleontological records brings new insights into bottom water and climate conditions in SMB, indicating regional similarities and differences with adjacent basins, and provides insight into the causes for changes in bottom water oxygenation.« less

Pigeons (Columba livia) show change blindness in a color-change detection task.

PubMed

Herbranson, Walter T; Jeffers, Jacob S

2017-07-01

Change blindness is a phenomenon whereby changes to a stimulus are more likely go unnoticed under certain circumstances. Pigeons learned a change detection task, in which they observed sequential stimulus displays consisting of individual colors back-projected onto three response keys. The color of one response key changed during each sequence and pecks to the key that displayed the change were reinforced. Pigeons showed a change blindness effect, in that change detection accuracy was worse when there was an inter-stimulus interval interrupting the transition between consecutive stimulus displays. Birds successfully transferred to stimulus displays involving novel colors, indicating that pigeons learned a general change detection rule. Furthermore, analysis of responses to specific color combinations showed that pigeons could detect changes involving both spectral and non-spectral colors and that accuracy was better for changes involving greater differences in wavelength. These results build upon previous investigations of change blindness in both humans and pigeons and suggest that change blindness may be a general consequence of selective visual attention relevant to multiple species and stimulus dimensions.

40-year trends in meal and snack eating behaviors of American adults

PubMed Central

Kant, Ashima K.; Graubard, Barry I.

2014-01-01

Background Understanding of changes in profiles of eating behaviors over time may provide insights into contributors to upward trajectories of obesity in the United States population. Yet, little is known about whether characteristics of meal and snack eating behaviors reported by adult Americans have changed over time. Objective This study examined time trends in the distribution of day’s intake into individual meal and snack behaviors and related attributes in the United States adult population. Design The study was observational with cross-sectional data from national surveys fielded over 40 years. Participant/setting Nationally representative dietary data from nine National Health and Nutrition Examination Surveys conducted from 1971–74 to 2009–2010 (n=62298; age 20–74 years) were used to describe eating behaviors. Outcomes examined The respondent-labeled eating behaviors examined included main meals (breakfast, lunch, and dinner), and snacks (before breakfast, between breakfast and lunch, between lunch and dinner, after dinner, or other). For each eating behavior, percent of reporters; relative contribution to 24-hour energy intake; the clock time of report; and intermeal/snack intervals were examined. Statistical Analysis Multivariable logistic and linear regression methods for analysis of complex survey data adjusted for characteristics of respondents in each survey. Results Over the 40-year span examined: 1) reports of each individual named main meal (or all three main meals) declined, but reports of only two out of three meals or the same meal more than once increased; 2) the percentage of 24-hour energy from snacks reported between lunch and dinner or snacks that displaced meals increased; 3) clock times of breakfast and lunch were later, and intervals between dinner and after dinner snack were shorter. Changes in several snack reporting behaviors (e.g., report of any snack or ≥2 snacks), were significant in women only. Conclusions Several meal and snack eating behaviors of American adults changed over time, with a greater change in snack behaviors of women relative to men. PMID:25088521

Cardiac response to whole-body heating

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

Frey, M.A.B.; Kenney, R.A.

1979-04-01

Systolic time interval analysis was used to assess changes in ventricular function during heat stress. Seven subjects (4 M + 3 F, 22-35 yr) participated in the experiments. The heating procedure was the following: both legs of seated subjects were immersed to the knees in stirred water maintained at 42-45 C. The subjects' upper legs and trunks were enclosed in nonpermeable plastic and covered with a sheet blanket to reduce heat loss. After 30 min of heating, the water and plastic were removed. The parameters measured were HR and R-R interval, LVET, and PEP. Results were compared by t testmore » at the 0.05 significance level. The results pointed to a two-stage cardiac response to heat-vagal withdrawal followed by a strong sympathetic outflow to the heart affecting both inotropic and chronotropic characteristics.« less

The effect of inter-set rest intervals on resistance exercise-induced muscle hypertrophy.

PubMed

Henselmans, Menno; Schoenfeld, Brad J

2014-12-01

Due to a scarcity of longitudinal trials directly measuring changes in muscle girth, previous recommendations for inter-set rest intervals in resistance training programs designed to stimulate muscular hypertrophy were primarily based on the post-exercise endocrinological response and other mechanisms theoretically related to muscle growth. New research regarding the effects of inter-set rest interval manipulation on resistance training-induced muscular hypertrophy is reviewed here to evaluate current practices and provide directions for future research. Of the studies measuring long-term muscle hypertrophy in groups employing different rest intervals, none have found superior muscle growth in the shorter compared with the longer rest interval group and one study has found the opposite. Rest intervals less than 1 minute can result in acute increases in serum growth hormone levels and these rest intervals also decrease the serum testosterone to cortisol ratio. Long-term adaptations may abate the post-exercise endocrinological response and the relationship between the transient change in hormonal production and chronic muscular hypertrophy is highly contentious and appears to be weak. The relationship between the rest interval-mediated effect on immune system response, muscle damage, metabolic stress, or energy production capacity and muscle hypertrophy is still ambiguous and largely theoretical. In conclusion, the literature does not support the hypothesis that training for muscle hypertrophy requires shorter rest intervals than training for strength development or that predetermined rest intervals are preferable to auto-regulated rest periods in this regard.

55-year (1960-2015) spatiotemporal shoreline change analysis using historical DISP and Landsat time series data in Shanghai

NASA Astrophysics Data System (ADS)

Qiao, Gang; Mi, Huan; Wang, Weian; Tong, Xiaohua; Li, Zhongbin; Li, Tan; Liu, Shijie; Hong, Yang

2018-06-01

Shoreline change has been an increasing concern for low-lying and vulnerable coastal zones worldwide, especially in estuarine delta regions, which generally have significant economic development, large human settlements and infrastructures. Thus, long time-series shoreline change data are useful for understanding how shorelines respond to natural and anthropogenic activities, as well as for providing greater insights into coastal protection and sustainable development in the future. For the first time, this study analyzes 55 years of spatiotemporal shoreline changes in Shanghai, China, by integrating the historical Declassified Intelligence Satellite Photography (DISP) and Landsat time series data at five-year intervals from 1960 to 2015. Twelve shorelines were interpreted from DISP and Landsat images. The spatiotemporal changes in the shorelines were explored at five-year intervals within the study period for the Shanghai mainland and islands. The results indicate that shorelines in Shanghai accreted significantly over the last 55 years, but different accretion patterns were observed in Chongming Dongtan. The rate of shoreline change varied in different areas, and the most noticeable expansions were Chongming Beitan, Chongming Dongtan, Hengsha Dongtan, and Nanhuizui. The length of the entire shoreline increased by 25.7% from 472.6 km in 1960 to 594.2 km in 2015. Due to the shoreline changes, the Shanghai area expanded by 1,192.5 km2 by 2015, which was an increase of 19.9% relative to its 1960 area. The Digital Shoreline Analysis System (DSAS) was used to compute rate-of-change statistics. Between 1960 and 2015, 10.6% of the total transects exceeded 3 km of Net Shoreline Movement (NSM), with a maximum value of approximately 20 km at eastern Hengsha Island. The average Weighted Linear Regression Rate (WLR) of the Shanghai shoreline was 52.2 m/yr from 1960 to 2015; there was 94.1% accretion, 3.1% erosion, and 2.8% with no significant change. In addition, the driving forces of the shoreline changes were also explored in detail. Compared with natural factors, such as relative Sea Level Rise (SLR) and the reduction in sediment loading from the Yangtze River, anthropogenic activities that include land reclamation and channel projects are the primary causes of the shoreline changes in Shanghai.

Vagal modulation and symptomatology following a 6-month aerobic exercise program for women with fibromyalgia.

PubMed

Sañudo, Borja; Carrasco, Luis; de Hoyo, Moisés; Figueroa, Arturo; Saxton, John M

2015-01-01

To examine the effects of a supervised aerobic exercise programme on heart rate variability (HRV) parameters and symptom severity in women with fibromyalgia (FM). Thirty-two women with FM were randomly allocated to one of two groups: aerobic exercise (AE) or usual care control for 24 weeks. Women allocated to AE performed two aerobic exercise sessions per week of 45-60 min duration including 15-20 min of steady-state aerobic exercise at 60-65% of predicted maximum heart rate (HRmax) and 15 min of interval training at 75-80% HRmax (six repetitions of 1.5 min, with 1 min interpolated rest intervals). Cardiac autonomic modulation was assessed using power spectral analysis of HRV. Symptom severity was assessed by a 10 cm visual analogue scale (VAS) for pain, sleep disturbances, stiffness, anxiety and depression. After 24 weeks, the women in the exercise group showed an increase (4.8 ± 0.2 to 5.2 ± 0.2) in total power (LnTP, p<0.001), low frequency power (LnLF, p<0.01), high frequency power (LnHF, p<0.001), and the root-mean-square of successive R-R intervals (rMSSD, p<0.001). In addition, significant group-by-time interaction effects were observed for LnHF (p=0.036) and LnLF/HF (p=0.014). Improvements in anxiety and depression were also observed in AE versus control patients. These results show that a programme of aerobic exercise training induced changes in cardiac autonomic nervous system modulation in FM and that these changes in HRV parameters were accompanied by changes in anxiety and depression.

A difference in systolic blood pressure between arms is a novel predictor of the development and progression of diabetic nephropathy in patients with type 2 diabetes.

PubMed

Okada, Hiroshi; Fukui, Michiaki; Tanaka, Muhei; Matsumoto, Shinobu; Iwase, Hiroya; Kobayashi, Kanae; Asano, Mai; Yamazaki, Masahiro; Hasegawa, Goji; Nakamura, Naoto

2013-10-01

Recent studies have suggested that a difference in systolic blood pressure (SBP) between arms is associated with both vascular disease and mortality. The aim of this study was to investigate the relationship between a difference in SBP between arms and change in urinary albumin excretion or development of albuminuria in patients with type 2 diabetes. We measured SBP in 408 consecutive patients with type 2 diabetes, and calculated a difference in SBP between arms. We performed follow-up study to assess change in urinary albumin excretion or development of albuminuria, mean interval of which was 4.6 ± 1.7 years. We then evaluated the relationship of a difference in SBP between arms to diabetic nephropathy using multiple regression analysis and multiple Cox regression model. Multiple regression analyses demonstrated that a difference in SBP between arms was independently associated with change in urinary albumin excretion (β = 0.1869, P = 0.0010). Adjusted Cox regression analyses demonstrated that a difference in SBP between arms was associated with an increased hazard of development of albuminuria; hazard ratio was 1.215 (95% confidence interval 1.077-1.376). Moreover, the risk of development of albuminuria was increased in patients with a difference in SBP of equal to or more than 10 mmHg between arms; hazard ratio was 4.168 (95% confidence interval 1.478-11.70). A difference in SBP between arms could be a novel predictor of the development and progression of diabetic nephropathy in patients with type 2 diabetes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The Early Toarcian oceanic anoxic event: Paleoenvironmental and paleoclimatic change across the Alpine Tethys (Switzerland)

NASA Astrophysics Data System (ADS)

Fantasia, Alicia; Föllmi, Karl B.; Adatte, Thierry; Spangenberg, Jorge E.; Montero-Serrano, Jean-Carlos

2018-03-01

Paleoenvironmental and paleoclimatic change associated with the Toarcian oceanic anoxic event (T-OAE) was evaluated in five successions located in Switzerland. They represent different paleogeographic settings across the Alpine Tethys: the northern shelf (Gipf, Riniken and Rietheim), the Sub-Briançonnais basin (Creux de l'Ours), and the Lombardian basin (Breggia). The multi-proxy approach chosen (whole-rock and clay mineralogy, phosphorus, major and trace elements) shows that local environmental conditions modulated the response to the T-OAE across the Alpine Tethys. On the northern shelf and in the Sub-Briançonnais basin, high kaolinite contents and detrital proxies (detrital index, Ti, Zr, Si) in the T-OAE interval suggest a change towards a warmer and more humid climate coupled with an increase in the chemical weathering rates. In contrast, low kaolinite content in the Lombardian basin is likely related to a more arid climate along the southern Tethys margin and/or to a deeper and more distal setting. Redox-sensitive trace-element (V, Mo, Cu, Ni) enrichments in the T-OAE intervals reveal that dysoxic to anoxic conditions developed on the northern shelf, whereas reducing conditions were less severe in the Sub-Briançonnais basin. In the Lombardian basin well-oxygenated bottom water conditions prevailed. Phosphorus (P) speciation analysis was performed at Riniken and Creux de l'Ours. This is the first report of P speciation data for T-OAE sections, clearly suggesting that high P contents during this time interval are mainly linked to the presence of an authigenic phases and fish remains. The development of oxygen-depleted conditions during the T-OAE seems to have promoted the release of the organic-bound P back into the water column, thereby further sustaining primary productivity in a positive feedback loop.

Augmented baroreflex heart rate gain after moderate-intensity, dynamic exercise

NASA Technical Reports Server (NTRS)

Halliwill, J. R.; Taylor, J. A.; Hartwig, T. D.; Eckberg, D. L.

1996-01-01

The occurrence of a sustained vasodilation and hypotension after acute, dynamic exercise suggests that exercise may alter arterial baroreflex mechanisms. Therefore, we assessed systemic hemodynamics, baroreflex regulation of heart rate, and cardiac vagal tone after 60 min of cycling at 60% peak oxygen consumption in 12 healthy, untrained men and women (ages 21-28 yr). We derived sigmoidal carotid-cardiac baroreflex relations by measurement of R-R interval changes induced by ramped, stepwise, R-wave-triggered changes in external neck pressure from 40 to -65 mmHg. We estimated tonic cardiac vagal control with power spectral analysis of R-R interval variability in the respiratory frequency band (0.2-0.3 Hz) during frequency- and tidal volume-controlled breathing. Both mean arterial pressure and total peripheral resistance were reduced postexercise [pressure: from 86 +/- 2 (mean +/- SE) to 81 +/- 2 mmHg; resistance: from 23 +/- 2 to 16 +/- 1 units; both P < 0.05]. Cardiac output was increased postexercise (from 3.9 +/- 0.3 to 5.5 +/- 0.5 l/min, P < 0.05). Both slope and range of the carotid-cardiac baroreflex relation were increased postexercise (slope: from 4.7 +/- 0.7 to 6.1 +/- 0.9 ms/mmHg; range: from 186 +/- 23 to 238 +/- 30 ms, P < 0.05). Respiratory R-R interval variability (cardiac vagal tone) was not changed at any time after exercise, whereas heart rate and plasma norepinephrine levels were elevated. Thus moderate-intensity, dynamic exercise increases heart rate and cardiac output, reduces peripheral vascular resistance, and augments baroreflex responsiveness. Our data suggest that augmented baroreflex heart rate gain restrains rather than contributes to postexercise hypotension, which appears to be mediated predominately by vasodilation.

Dietary Variety and Decline in Lean Mass and Physical Performance in Community-Dwelling Older Japanese: A 4-year Follow-Up Study.

PubMed

Yokoyama, Y; Nishi, M; Murayama, H; Amano, H; Taniguchi, Y; Nofuji, Y; Narita, M; Matsuo, E; Seino, S; Kawano, Y; Shinkai, S

2017-01-01

To examine associations of dietary variety with changes in lean mass and physical performance during a 4-year period in an elderly Japanese population. Four-year prospective study. The Hatoyama Cohort Study and Kusatsu Longitudinal Study, Japan. 935 community-dwelling Japanese aged 65 years or older. Dietary variety was assessed using a 10-item food frequency questionnaire. Body composition was determined by multifrequency bioelectrical impedance analysis, and physical performance (grip strength and usual gait speed) was measured in surveys at baseline and 4 years later. Longitudinal analysis included only participants who were originally in the upper three quartiles of lean body mass, appendicular lean mass, grip strength, and usual gait speed. The outcome measures were decline in lean body mass, appendicular lean mass, grip strength, and usual gait speed, defined as a decrease to the lowest baseline quartile level at the 4-year follow-up survey. Associations of dietary variety with the outcome measures were examined by logistic regression analysis adjusted for potential confounders. In the fully adjusted model, the odds ratios for decline in grip strength and usual gait speed were 0.43 (95% confidence interval, 0.19-0.99) and 0.43 (confidence interval, 0.19-0.99), respectively, for participants in the highest category of dietary variety score as compared with those in the lowest category. Dietary variety was not significantly associated with changes in lean body mass or appendicular lean mass. Among older adults, greater dietary variety may help maintain physical performance, such as grip strength and usual gait speed, but not lean mass.

Motion of Major Ice Shelf Fronts in Antarctica from Slant Range Analysis of Radar Altimeter Data, 1978 - 1998

NASA Technical Reports Server (NTRS)

Zwally, H. J.; Beckley, M. A.; Brenner, A. C.; Giovinetto, M. B.; Koblinsky, Chester J. (Technical Monitor)

2001-01-01

Slant range analysis of radar altimeter data from the Seasat, Geosat, ERS-1 and ERS-2 databases are used to determine barrier location at particular times, and estimate barrier motion (km/yr) for major Antarctic ice shelves. The barrier locations, which are the seaward edges or fronts of floating ice shelves, advance with time as the ice flows from the grounded ice sheets and retreat whenever icebergs calve from the fronts. The analysis covers various multiyear intervals from 1978 to 1998, supplemented by barrier location maps produced elsewhere for 1977 and 1986. Barrier motion is estimated as the ratio between mean annual ice shelf area change for a particular interval, and the length of the discharge periphery. This value is positive if the barrier location progresses seaward, or negative if the barrier location regresses (break-back). Either positive or negative values are lower limit estimates because the method does not detect relatively small area changes due to calving or surge events. The findings are discussed in the context of the three ice shelves that lie in large embayments (the Filchner-Ronne, Amery, and Ross), and marginal ice shelves characterized by relatively short distances between main segments of grounding line and barrier (those in the Queen Maud Land sector between 10.1 deg. W and 32.5 deg. E, and the West and Shackleton ice shelves). All the ice shelves included in the study account for approximately three-fourths of the total ice shelf area of Antarctica, and discharge approximately two-thirds of the total grounded ice area.

Computer program for analysis of hemodynamic response to head-up tilt test

NASA Astrophysics Data System (ADS)

ŚwiÄ tek, Eliza; Cybulski, Gerard; Koźluk, Edward; PiÄ tkowska, Agnieszka; Niewiadomski, Wiktor

2014-11-01

The aim of this work was to create a computer program, written in the MATLAB environment, which enables the visualization and analysis of hemodynamic parameters recorded during a passive tilt test using the CNS Task Force Monitor System. The application was created to help in the assessment of the relationship between the values and dynamics of changes of the selected parameters and the risk of orthostatic syncope. The signal analysis included: R-R intervals (RRI), heart rate (HR), systolic blood pressure (sBP), diastolic blood pressure (dBP), mean blood pressure (mBP), stroke volume (SV), stroke index (SI), cardiac output (CO), cardiac index (CI), total peripheral resistance (TPR), total peripheral resistance index (TPRI), ventricular ejection time (LVET) and thoracic fluid content (TFC). The program enables the user to visualize waveforms for a selected parameter and to perform smoothing with selected moving average parameters. It allows one to construct the graph of means for any range, and the Poincare plot for a selected time range. The program automatically determines the average value of the parameter before tilt, its minimum and maximum value immediately after changing positions and the times of their occurrence. It is possible to correct the automatically detected points manually. For the RR interval, it determines the acceleration index (AI) and the brake index (BI). It is possible to save calculated values to an XLS with a name specified by user. The application has a user-friendly graphical interface and can run on a computer that has no MATLAB software.

Series length used during trend analysis affects sensitivity to changes in progression rate in the ocular hypertension treatment study.

PubMed

Gardiner, Stuart K; Demirel, Shaban; De Moraes, Carlos Gustavo; Liebmann, Jeffrey M; Cioffi, George A; Ritch, Robert; Gordon, Mae O; Kass, Michael A

2013-02-15

Trend analysis techniques to detect glaucomatous progression typically assume a constant rate of change. This study uses data from the Ocular Hypertension Treatment Study to assess whether this assumption decreases sensitivity to changes in progression rate, by including earlier periods of stability. Series of visual fields (mean 24 per eye) completed at 6-month intervals from participants randomized initially to observation were split into subseries before and after the initiation of treatment (the "split-point"). The mean deviation rate of change (MDR) was derived using these entire subseries, and using only the window length (W) tests nearest the split-point, for different window lengths of W tests. A generalized estimating equation model was used to detect changes in MDR occurring at the split-point. Using shortened subseries with W = 7 tests, the MDR slowed by 0.142 dB/y upon initiation of treatment (P < 0.001), and the proportion of eyes showing "rapid deterioration" (MDR <-0.5 dB/y with P < 5%) decreased from 11.8% to 6.5% (P < 0.001). Using the entire sequence, no significant change in MDR was detected (P = 0.796), and there was no change in the proportion of eyes progressing (P = 0.084). Window lengths 6 ≤ W ≤ 9 produced similar benefits. Event analysis revealed a beneficial treatment effect in this dataset. This effect was not detected by linear trend analysis applied to entire series, but was detected when using shorter subseries of length between six and nine fields. Using linear trend analysis on the entire field sequence may not be optimal for detecting and monitoring progression. Nonlinear analyses may be needed for long series of fields. (ClinicalTrials.gov number, NCT00000125.).

It's time to fear! Interval timing in odor fear conditioning in rats

PubMed Central

Shionoya, Kiseko; Hegoburu, Chloé; Brown, Bruce L.; Sullivan, Regina M.; Doyère, Valérie; Mouly, Anne-Marie

2013-01-01

Time perception is crucial to goal attainment in humans and other animals, and interval timing also guides fundamental animal behaviors. Accumulating evidence has made it clear that in associative learning, temporal relations between events are encoded, and a few studies suggest this temporal learning occurs very rapidly. Most of these studies, however, have used methodologies that do not permit investigating the emergence of this temporal learning. In the present study we monitored respiration, ultrasonic vocalization (USV) and freezing behavior in rats in order to perform fine-grain analysis of fear responses during odor fear conditioning. In this paradigm an initially neutral odor (the conditioned stimulus, CS) predicted the arrival of an aversive unconditioned stimulus (US, footshock) at a fixed 20-s time interval. We first investigated the development of a temporal pattern of responding related to CS-US interval duration. The data showed that during acquisition with odor-shock pairings, a temporal response pattern of respiration rate was observed. Changing the CS-US interval duration from 20-s to 30-s resulted in a shift of the temporal response pattern appropriate to the new duration thus demonstrating that the pattern reflected the learning of the CS-US interval. A temporal pattern was also observed during a retention test 24 h later for both respiration and freezing measures, suggesting that the animals had stored the interval duration in long-term memory. We then investigated the role of intra-amygdalar dopaminergic transmission in interval timing. For this purpose, the D1 dopaminergic receptors antagonist SCH23390 was infused in the basolateral amygdala before conditioning. This resulted in an alteration of timing behavior, as reflected in differential temporal patterns between groups observed in a 24 h retention test off drug. The present data suggest that D1 receptor dopaminergic transmission within the amygdala is involved in temporal processing. PMID:24098277

Delayed Traumatic Intracranial Haemorrhage and Progressive Traumatic Brain Injury in a Major Referral Centre Based in a Developing Country

PubMed Central

Jeng, Toh Charng; Haspani, Mohd Saffari Mohd; Adnan, Johari Siregar; Naing, Nyi Nyi

2008-01-01

A repeat Computer Tomographic (CT) brain after 24–48 hours from the 1st scanning is usually practiced in most hospitals in South East Asia where intracranial pressure monitoring (ICP) is routinely not done. This interval for repeat CT would be shortened if there was a deterioration in Glasgow Coma Scale (GCS). Most of the time the prognosis of any intervention may be too late especially in hospitals with high patient-to-doctor ratio causing high mortality and morbidity. The purpose of this study was to determine the important predictors for early detection of Delayed Traumatic Intracranial Haemorrhage (DTICH) and Progressive Traumatic Brain Injury (PTBI) before deterioration of GCS occurred, as well as the most ideal timing of repeated CT brain for patients admitted in Malaysian hospitals. A total of 81 patients were included in this study over a period of six months. The CT scan brain was studied by comparing the first and second CT brain to diagnose the presence of DTICH/PTBI. The predictors tested were categorised into patient factors, CT brain findings and laboratory investigations. The mean age was 33.1 ± 15.7 years with a male preponderance of 6.36:1. Among them, 81.5% were patients from road traffic accidents with Glasgow Coma Scale ranging from 4 – 15 (median of 12) upon admission. The mean time interval delay between trauma and first CT brain was 179.8 ± 121.3 minutes for the PTBI group. The DTICH group, 9.9% of the patients were found to have new intracranial clots. Significant predictors detected were different referral hospitals (p=0.02), total GCS status (p=0.026), motor component of GCS (p=0.043), haemoglobin level (p<0.001), platelet count (p=0.011) and time interval between trauma and first CT brain (p=0.022). In the PTBI group, 42.0% of the patients were found to have new changes (new clot occurrence, old clot expansion and oedema) in the repeat CT brain. Univariate statistical analysis revealed that age (p=0.03), race (p=0.035), types of admission (p=0.024), GCS status (p=0.02), pupillary changes (p=0.014), number of intracranial lesion (p=0.004), haemoglobin level (p=0.038), prothrombin time (p=0.016) as the best predictors of early detection of changes. Multiple logistics regression analysis indicated that age, severity, GCS status (motor component) and GCS during admission were significantly associated with second CT scan with changes. This study showed that 9.9% of the total patients seen in the period of study had DTICH and 42% had PTBI. In the early period after traumatic head injury, the initial CT brain did not reveal the full extent of haemorrhagic injury and associated cerebral oedema. Different referral hospitals of different trauma level, GCS status, motor component of the GCS, haemoglobin level, platelet count and time interval between trauma and the first CT brain were the significant predictors for DTICH. Whereas the key determinants of PTBI were age, race, types of admission, GCS status, pupillary changes, number of intracranial bleed, haemoglobin level, prothrombin time and of course time interval between trauma and first CT brain. Any patients who had traumatic head injury in hospitals with no protocol of repeat CT scan or intracranial pressure monitoring especially in developing countries are advised to have to repeat CT brain at the appropriate quickest time . PMID:22589639

High-resolution analysis of upper Miocene lake deposits: Evidence for the influence of Gleissberg-band solar forcing

PubMed Central

Kern, Andrea K.; Harzhauser, Mathias; Soliman, Ali; Piller, Werner E.; Mandic, Oleg

2013-01-01

A high-resolution multi-proxy analysis was conducted on a 1.5-m-long core of Tortonian age (~ 10.5 Ma; Late Miocene) from Austria (Europe). The lake sediments were studied with a 1-cm resolution to detect all small-scale variations based on palynomorphs (pollen and dinoflagellate cysts), ostracod abundance, geochemistry (carbon and sulfur) and geophysics (magnetic susceptibility and natural gamma radiation). Based on an already established age model for a longer interval of the same core, this sequence can be limited to approx. two millennia of Late Miocene time with a resolution of ~ 13.7 years per sample. The previous study documented the presence of solar forcing, which was verified within various proxies on this 1.5-m core by a combination of REDFIT spectra and Gaussian filters. Significant repetitive signals ranged in two discrete intervals corresponding roughly to 55–82 and 110–123 years, fitting well within the lower and upper Gleissberg cycle ranges. Based on these results, the environmental changes along the 2000-year Late Miocene sequence are discussed. No major ecological turnovers are expected in this very short interval. Nonetheless, even within this brief time span, dinoflagellates document rapid changes between oligotrophic and eutrophic conditions, which are frequently coupled with lake stratification and dysoxic bottom waters. These phases prevented ostracods and molluscs from settling and promoted the activity of sulfur bacteria. The pollen record indicates rather stable wetland vegetation with a forested hinterland. Shifts in the pollen spectra can be mainly attributed to variations in transport mechanisms. These are represented by a few phases of fluvial input but mainly by changes in wind intensity and probably also wind direction. Such influence is most likely caused by solar cycles, leading to a change in source area for the input into the lake. Furthermore, these solar-induced variations seem to be modulated by longer solar cycles. The filtered data display comparable patterns and modulations, which seem to be forced by the 1000-year and 1500-year cycles. The 1000-year cycle modulated especially the lake surface proxies, whereas the 1500-year cycle is mainly reflected in hinterland proxies, indicating strong influence on transport mechanisms. PMID:23407808

The role of figure-ground segregation in change blindness.

PubMed

Landman, Rogier; Spekreijse, Henk; Lamme, Victor A F

2004-04-01

Partial report methods have shown that a large-capacity representation exists for a few hundred milliseconds after a picture has disappeared. However, change blindness studies indicate that very limited information remains available when a changed version of the image is presented subsequently. What happens to the large-capacity representation? New input after the first image may interfere, but this is likely to depend on the characteristics of the new input. In our first experiment, we show that a display containing homogeneous image elements between changing images does not render the large-capacity representation unavailable. Interference occurs when these new elements define objects. On that basis we introduce a new method to produce change blindness: The second experiment shows that change blindness can be induced by redefining figure and background, without an interval between the displays. The local features (line segments) that defined figures and background were swapped, while the contours of the figures remained where they were. Normally, changes are easily detected when there is no interval. However, our paradigm results in massive change blindness. We propose that in a change blindness experiment, there is a large-capacity representation of the original image when it is followed by a homogeneous interval display, but that change blindness occurs whenever the changed image forces resegregation of figures from the background.

Enhanced marine productivity off western North America during warm climate intervals of the past 52 k.y

USGS Publications Warehouse

Ortiz, J.D.; O'Connell, S. B.; DelViscio, J.; Dean, W.; Carriquiry, J.D.; Marchitto, T.; Zheng, Yen; VanGeen, A.

2004-01-01

Studies of the Santa Barbara Basin off the coast of California have linked changes in its bottom-water oxygen content to millennial-scale climate changes as recorded by the oxygen isotope composition of Greenland ice. Through the use of detailed records from a sediment core collected off the Magdalena Margin of Baja California, Mexico, we demonstrate that this teleconnection predominantly arose from changes in marine productivity, rather than changes in ventilation of the North Pacific, as was originally proposed. One possible interpretation is that the modern balance of El Nin??o-La Nin??a conditions that favors a shallow nutricline and high productivity today and during warm climate intervals of the past 52 k.y. was altered toward more frequent, deep nutricline, low productivity, El Nin??o-like conditions during cool climate intervals. ?? 2004 Geological Society of America.

Resistance to reinforcement change in multiple and concurrent schedules assessed in transition and at steady state.

PubMed

McLean, A P; Blampied, N M

1995-01-01

Behavioral momentum theory relates resistance to change of responding in a multiple-schedule component to the total reinforcement obtained in that component, regardless of how the reinforcers are produced. Four pigeons responded in a series of multiple-schedule conditions in which a variable-interval 40-s schedule arranged reinforcers for pecking in one component and a variable-interval 360-s schedule arranged them in the other. In addition, responses on a second key were reinforced according to variable-interval schedules that were equal in the two components. In different parts of the experiment, responding was disrupted by changing the rate of reinforcement on the second key or by delivering response-independent food during a blackout separating the two components. Consistent with momentum theory, responding on the first key in Part 1 changed more in the component with the lower reinforcement total when it was disrupted by changes in the rate of reinforcement on the second key. However, responding on the second key changed more in the component with the higher reinforcement total. In Parts 2 and 3, responding was disrupted with free food presented during intercomponent blackouts, with extinction (Part 2) or variable-interval 80-s reinforcement (Part 3) arranged on the second key. Here, resistance to change was greater for the component with greater overall reinforcement. Failures of momentum theory to predict short-term differences in resistance to change occurred with disruptors that caused greater change between steady states for the richer component. Consistency of effects across disruptors may yet be found if short-term effects of disruptors are assessed relative to the extent of change observed after prolonged exposure.

Long-Duration Space Flight Provokes Pathologic Q-Tc Interval Prolongation

NASA Technical Reports Server (NTRS)

D'Aunno, DOminick S.; Dougherty, Anne H.; DeBlock, Heidi F.; Meck, Janice V.

2002-01-01

Space flight has a profound influence on the cardiovascular and autonomic nervous systems. Alterations in baroreflex function, plasma catecholamine concentrations, and arterial pressure regulation have been observed. Changes in autonomic regulation of cardiac function may lead to serious rhythm disturbances. In fact, ventricular tachycardia has been reported during long-duration space flight. The study aim was to determine the effects of space flight on cardiac conduction. Methods and Results: Electrocardiograms (ECGs) and serum electrolytes were obtained before and after short-duration (SD) (4-16 days) and long-duration (LD) (4-6 months) missions. Holter recordings were obtained from 3 different subjects before, during and after a 4-month mission. P-R, R-R, and Q-T intervals were measured manually in a random, blinded fashion and Bazzet's formula used to correct the Q-T interval (Q-Tc). Space flight had no clinically significant effect on electrolyte concentrations. P-R and RR intervals were decreased after SD flight (p<0.05) and recovered 3 days after landing. In the same subjects, P-R and Q-Tc intervals were prolonged after LD flight (p<0.01). Clinically significant Q-Tc prolongation (>0.44 sec) occurred during the first month of flight and persisted until 3 days after landing (p<0.01). Conclusions - Space flight alters cardiac conduction with more ominous changes seen with LD missions. Alterations in autonomic tone may explain ECG changes associated with space flight. Primary cardiac changes may also contribute to the conduction changes with LD flight. Q-Tc prolongation may predispose astronauts to ventricular arrhythmias during and after long-duration space flight.

Holocene Paleohydrological Changes in Northern Michigan: Interpretations of Biomarker Distributions and Compound Specific Stable Isotope Analysis from Peatlands

NASA Astrophysics Data System (ADS)

Nichols, J. E.; Booth, R. K.; Jackson, S. T.; Pendall, E. G.; Huang, Y.

2006-12-01

Sediments of ombrotrophic peatlands are excellent archives for reconstructing past changes in precipitation/evaporation (P/E) balance. Multiproxy analysis of these sediments is critical for better understanding of climatic events experienced by these highly sensitive systems, as each proxy may respond to different climate parameters. In this study, we use distributions of n-alkanes and δD of Sphagnum biomarkers to interpret paleohydrology from sediments of Irwin Smith Bog, northern Michigan. We then integrate these data with pollen data and testate amoebae-inferred water table depth. Sphagnum moss is the dominant peat former in ombrotrophic bogs, but vascular plants become abundant when water tables are drawn down. Thus, the abundance of Sphagnum relative to vascular plants is indicative of peatland hydrology. The n-alkanes produced by Sphagnum differ from vascular plants in the relative abundance of the different homologues, with the former having excess amounts of shorter chain C23 n-alkane. We use several measures (compound ratios, PCA) to show changes in then-alkane distributions in the sediments, and thus changes in the peatland plant community. Our data provide high- resolution, quantitative paleohydrological records for the study region that are consistent with other records. We also show that the relative abundance of a newly identified Sphagnum biomarker, 2-heptacosanone, can be used to reconstruct changing plant communities. Because ombrotrophic systems lose water by evaporation, drier/warmer conditions cause hydrogen isotopic enrichment of bog water and Sphagnum biomarkers. We measured the δD of C23 n-alkane and 2-heptacosanone to provide additional paleoclimate information. Our multiproxy approach allows us to better understand the climate changes during key intervals of the Holocene. For example, a sharp decrease in the abundance of Tsuga canadensis (hemlock) pollen has been previously identified in records from many places throughout eastern North America. The cause of this mid-Holocene hemlock decline has been debated, making this interval of particular interest for paleoclimate studies. We will present new molecular and isotopic data to better understand the causation of this abrupt vegetation change.

[Heart rate variability study based on a novel RdR RR Intervals Scatter Plot].

PubMed

Lu, Hongwei; Lu, Xiuyun; Wang, Chunfang; Hua, Youyuan; Tian, Jiajia; Liu, Shihai

2014-08-01

On the basis of Poincare scatter plot and first order difference scatter plot, a novel heart rate variability (HRV) analysis method based on scatter plots of RR intervals and first order difference of RR intervals (namely, RdR) was proposed. The abscissa of the RdR scatter plot, the x-axis, is RR intervals and the ordinate, y-axis, is the difference between successive RR intervals. The RdR scatter plot includes the information of RR intervals and the difference between successive RR intervals, which captures more HRV information. By RdR scatter plot analysis of some records of MIT-BIH arrhythmias database, we found that the scatter plot of uncoupled premature ventricular contraction (PVC), coupled ventricular bigeminy and ventricular trigeminy PVC had specific graphic characteristics. The RdR scatter plot method has higher detecting performance than the Poincare scatter plot method, and simpler and more intuitive than the first order difference method.

Patient satisfaction with extended-interval warfarin monitoring.

PubMed

Carris, Nicholas W; Hwang, Andrew Y; Smith, Steven M; Taylor, James R; Sando, Karen; Powell, Jason; Rosenberg, Eric I; Zumberg, Marc S; Gums, John G; Dietrich, Eric A; Anderson, Katherine Vogel

2016-11-01

Extended-interval monitoring of warfarin has been proposed to reduce follow-up burden and improve patient satisfaction. We aimed to make an initial assessment of anticoagulation satisfaction before and after an extended-interval warfarin monitoring intervention. We conducted a translational prospective single-arm pilot study of extended-interval warfarin monitoring in five pharmacist-managed anticoagulation clinics. Patients meeting CHEST guideline criteria for extended-interval warfarin monitoring began progressive extended-interval follow-up (6, 8, and 12 weeks thereafter). The Duke Anticoagulation Satisfaction Scale (DASS) was administered at baseline and at end-of-study or study removal (in patients no longer appropriate for extended interval follow-up). Forty-six patients had evaluable pre- and post-intervention DASS survey data. Mean age of patients was 66.5 years, 74 % were non-Hispanic whites, and 48 % were men. Patients completed a mean ± SD of 34 ± 22 weeks of follow-up. Mean ± SD total DASS score at baseline was 45.2 ± 14.2 versus 49.1 ± 14.9 at end-of-study (mean change, +3.9 [95 % CI -0.6-8.4; p = 0.09]), indicating no benefit-and trending toward decrement-to anticoagulation satisfaction. Change in anticoagulation satisfaction varied substantially following extended-interval monitoring, with no evidence of improved satisfaction. Plausible reasons for patients not preferring extended-interval monitoring include increased anxiety and disengagement from self-management activities, both potentially related to less frequent feedback and reassurance during extended interval-monitoring. Additional research is needed to identify who is likely to benefit most from extended-interval monitoring. Anticoagulation satisfaction should be considered with clinical factors and shared-decision making when implementing extended-interval warfarin monitoring.

Identifying increased risk of post-infarct people with diabetes using multi-lag Tone-Entropy analysis.

PubMed

Karmakar, Chandan; Jelinek, Herbert; Khandoker, Ahsan; Tulppo, Mikko; Makikallio, Timo; Kiviniemi, Antti; Huikuri, Heikki; Palaniswami, Marimuthu

2012-01-01

Diabetes mellitus is associated with multi-organ system dysfunction. One of the key causative factors is the increased blood sugar level that leads to an increase in free radical activity and organ damage including the cardiovascular and nervous system. Heart rhythm is extrinsically modulated by the autonomic nervous system and cardiac autonomic neuropathy or dysautonomia has been shown to lead to sudden cardiac death in people with diabetes due to the decrease in heart rate variability (HRV). Current algorithms for determining HRV describe only beat-to-beat variation and therefore do not consider the ability of a heart beat to influence a train of succeeding beats. Therefore mortality risk analysis based on HRV has often not been able to discern the presence of an increased risk. This study used a novel innovation of the tone-entropy algorithm by incorporating increased lag intervals and found that both the sympatho-vagal balance and total activity changed at larger lag intervals. Tone-Entropy was found to be better risk identifier of cardiac mortality in people with diabetes at lags higher than one and best at lag seven.

Effect of static electronic advertising signs on road safety: an experimental case study.

PubMed

Izadpanah, Pedram; Omrani, Reza; Koo, Sheldon; Hadayeghi, Ali

2014-01-01

As technology continues to advance, the outdoor advertising industry is taking advantage of electronic signs, some of which are static electronic signs (SES), with the ability to automatically change the message shown on the sign at regular intervals. Studies indicate that SES has a negative impact on the drivers' visual attention and on vehicle control. However, the actual effects of the SES on the number of collisions have been difficult to prove conclusively. The objective of this article is to generate a clear understanding of the safety impacts of SES on the number collisions by conducting a before-and-after analysis with comparison groups. The analysis was based on a total of 10 SES along the Highway 27 and the Gardiner Expressway of the city of Toronto. The results of the before-and-after study revealed that there was not enough evidence to suggest that these signs have any impact on road safety along the adjacent roadway sections at a 95% confidence interval. The same results were obtained by comparing collisions that occurred during daylight and artificial light.

75 FR 39720 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-12

..., Inc. To List Options on Trust Issued Receipts in $1 Strike Intervals July 6, 2010. Pursuant to Section... strike price intervals for options on Trust Issued Receipts. The text of the proposed rule change is... strike price intervals for options on Trust Issued Receipts (``TIRs''), including Holding Company...

Estimation of postmortem interval through albumin in CSF by simple dye binding method.

PubMed

Parmar, Ankita K; Menon, Shobhana K

2015-12-01

Estimation of postmortem interval is a very important question in some medicolegal investigations. For the precise estimation of postmortem interval, there is a need of a method which can give accurate estimation. Bromocresol green (BCG) is a simple dye binding method and widely used in routine practice. Application of this method in forensic practice may bring revolutionary changes. In this study, cerebrospinal fluid was aspirated from cisternal puncture from 100 autopsies. A study was carried out on concentration of albumin with respect to postmortem interval. After death, albumin present in CSF undergoes changes, after 72 h of death, concentration of albumin has become 0.012 mM, and this decrease was linear from 2 h to 72 h. An important relationship was found between albumin concentration and postmortem interval with an error of ± 1-4h. The study concludes that CSF albumin can be a useful and significant parameter in estimation of postmortem interval. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

Effects of changing heart rate on electrophysiological and hemodynamic function in the dog.

PubMed

Hamlin, Robert L; Nakayama, Tomohiro; Nakayama, Hitomi; Carnes, Cynthia A

2003-03-14

Cardiovascular parameters were measured in dogs after RR interval was changed from 0.25 s to 1.2 s with atropine and graded doses of zatebradine, an I(f)-channel blocker. Left ventricular (LV) pre-ejection period (PEP), systemic vascular resistance, tau (an estimate of myocardial stiffness), PQ, QTc, dLVP/dt(max) and dLVP/dt(min), aortic pressure, and right atrial pressure did not change when each parameter was plotted against RR interval (r(2)'s < or = 0.5). LV end-diastolic pressure, stroke volume index, LV ejection time (ET), and QT all increased either linearly or curvilinearly as RR interval prolonged. Cardiac output index and PEP/ET decreased curvilinearly. When heart rate (HR) was fixed by pacing, and graded doses of zatebradine were given, changes in cardiovascular function were minimal. Thus zatebradine affects cardiovascular function principally by changing HR and not by affecting function directly. This study provides data on the effects of changing HR, alone, on cardiovascular parameters measured frequently during pharmacological and toxicological studies. It should prove useful when physiological variables, including HR, change, and there is need to know what change in HR, alone, contributes.

The effect of growth hormone replacement in patients with hypopituitarism on pituitary tumor recurrence, secondary cancer, and stroke.

PubMed

Jasim, Sina; Alahdab, Fares; Ahmed, Ahmed T; Tamhane, Shrikant U; Sharma, Anu; Donegan, Diane; Nippoldt, Todd B; Murad, M Hassan

2017-05-01

Growth hormone replacement therapy has benefits for patients with hypopituitarism. The safety profile in regard to tumor recurrence or progression, development of secondary malignancies, or cerebrovascular stroke is still an area of debate. A comprehensive search of multiple databases-MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus was conducted through August 2015. Eligible studies that evaluated long-term adverse events in adult patients with hypopituitarism treated with growth hormone replacement therapy and reported development of pituitary tumor recurrence or progression, secondary malignancies, or cerebrovascular stroke were selected following a predefined protocol. Reviewers, independently and in duplicate, extracted data and assessed the risk of bias. Random-effects meta-analysis was used to pool relative risks and 95 % confidence intervals. We included 15 studies (published 1995-2015) that reported on 46,148 patients. Compared to non-replacement, growth hormone replacement therapy in adults with hypopituitarism was not associated with statistically significant change in pituitary tumor progression or recurrence (relative risk, 0.77; 95 % confidence interval, 0.53-1.13) or development of secondary malignancy (relative risk, 0.99; 95 % confidence interval, 0.70-1.39). In two retrospective studies, there was higher risk of stroke in patients who did not receive replacement (relative risk, 2.07; 95 % confidence interval, 1.51-2.83). The quality of evidence is low due to study limitations and imprecision. This systematic review and meta-analysis supports the overall safety of growth hormone therapeutic use in adults with hypopituitarism with no clear evidence of increased risk of pituitary tumor recurrence, malignancy, or stroke.

Sympathoadrenal balance and physiological stress response in cattle at spontaneous and PGF2α-induced calving.

PubMed

Nagel, Christina; Trenk, Lisa; Aurich, Christine; Ille, Natascha; Pichler, Martina; Drillich, Marc; Pohl, Werner; Aurich, Jörg

2016-03-15

Increased cortisol release in parturient cows may either represent a stress response or is part of the endocrine changes that initiate calving. Acute stress elicits an increase in heart rate and decrease in heart rate variability (HRV). Therefore, we analyzed cortisol concentration, heart rate and HRV variables standard deviation of beat-to-beat interval (SDRR) and root mean square of successive beat-to-beat intervals (RMSSD) in dairy cows allowed to calve spontaneously (SPON, n = 6) or with PGF2α-induced preterm parturition (PG, n = 6). We hypothesized that calving is a stressor, but induced parturition is less stressful than term calving. Saliva collection for cortisol analysis and electrocardiogram recordings for heart rate and HRV analysis were performed from 32 hours before to 18.3 ± 0.7 hours after delivery. Cortisol concentration increased in SPON and PG cows, peaked 15 minutes after delivery (P < 0.001) but was higher in SPON versus PG cows (P < 0.001) during and within 2 hours after calving. Heart rate peaked during the expulsive phase of labor and was higher in SPON than in PG cows (time × group P < 0.01). The standard deviation of beat-to-beat interval and RMSSD peaked at the end of the expulsive phase of labor (P < 0.001), indicating high vagal activity. Standard deviation of beat-to-beat interval (P < 0.01) and RMSSD (P < 0.05) were higher in SPON versus PG cows. Based on physiological stress parameters, calving is perceived as stressful but expulsion of the calf is associated with a transiently increased vagal tone which may enhance uterine contractility. Copyright © 2016 Elsevier Inc. All rights reserved.

Temporal subtraction of chest radiographs compensating pose differences

NASA Astrophysics Data System (ADS)

von Berg, Jens; Dworzak, Jalda; Klinder, Tobias; Manke, Dirk; Kreth, Adrian; Lamecker, Hans; Zachow, Stefan; Lorenz, Cristian

2011-03-01

Temporal subtraction techniques using 2D image registration improve the detectability of interval changes from chest radiographs. Although such methods are well known for some time they are not widely used in radiologic practice. The reason is the occurrence of strong pose differences between two acquisitions with a time interval of months to years in between. Such strong perspective differences occur in a reasonable number of cases. They cannot be compensated by available image registration methods and thus mask interval changes to be undetectable. In this paper a method is proposed to estimate a 3D pose difference by the adaptation of a 3D rib cage model to both projections. The difference between both is then compensated for, thus producing a subtraction image with virtually no change in pose. The method generally assumes that no 3D image data is available from the patient. The accuracy of pose estimation is validated with chest phantom images acquired under controlled geometric conditions. A subtle interval change simulated by a piece of plastic foam attached to the phantom becomes visible in subtraction images generated with this technique even at strong angular pose differences like an anterior-posterior inclination of 13 degrees.

Mediterranean Outflow Water at the Pliocene/Pleistocene transition: New stratigraphic constraints from IODP Site U1389 (Gulf of Cadiz, IODP Expedition 339)

NASA Astrophysics Data System (ADS)

Grunert, Patrick; Balestra, Barbara; Auer, Gerald; Flores, José-Abel; Richter, Carl; García Gallardo, Ángela; Röhl, Ulla; Piller, Werner E.

2016-04-01

IODP Hole U1389E, at present located in the lower core of the Mediterranean Outflow Water (MOW) at 640m water depth in the northern Gulf of Cadiz, represents a key-site for the understanding of changes in MOW contribution to the North Atlantic during the late Pliocene and the transition into the Pleistocene ice house climate. Integrated geophysical, micropalaeontological and geochemical proxy records of the recovered sediments imply major changes in MOW strength over the studied interval. However, to consider these data in a broader paleoceanographic and paleoclimatic context, a well-constrained age model is essential. New bio-, chemo-, magnetostratigraphic data and XRF core-scanning suggest that the shipboard age model for the site has to be reconsidered as major changes in the depositional environment have not been recognized in the original, comparably low resolution data-sets. While the new, high-resolution biostratigraphic data confirm the overall time frame of 2.6 to 3.6 Myrs for the studied interval, they also indicate that the last occurrence of Discoaster tamalis in the succession should be reconsidered. New palaeomagnetic data constrain the Gauss normal chron and its subchrons more accurately. Finally, a high-resolution δ18O-record of the planktic foraminifer Globigerinoides ruber allows the identification of many marine isotopic chrons, further refining the stratigraphic framework. Cyclic patterns are recognized in the CaCO3 and TOC contents as well as Ca/Ti- and Zr/Al-ratios. A preliminary cyclostratigraphic analysis of these records in well-recovered intervals suggests an interplay of obliquity and precessional forcing reflected in a change from deposits strongly influenced by terrestrial input (3.0-2.8 Myrs) to deposits strongly affected by MOW (2.8-2.6 Myrs). This study contributes to project P25831-N29 of the Austrian Science Fund (FWF) and is financially supported by grants of ECORD and the Max Kade Foundation.

Effects of propylene glycol drenching before and after luteolysis on blood glucose, ovarian steroids and follicular dynamics in heifers.

PubMed

Umeki, A; Tanaka, T; Kamomae, H

2012-02-01

The effect of propylene glycol drenching on ovarian and hormonal dynamics was studied in heifers. Five cycling heifers were used twice (as control and treatment) with crossover design. After the confirmation of ovulation (day 0), the heifers in the treatment group received propylene glycol on days 6, 7 and 8 as an oral drench (250 ml of 90% propylene glycol). On day 10, prostaglandin F2α (PGF2α), 15 mg per head of dinoprost, was administered intramuscularly to induce luteal regression followed by the follicular phase and then propylene glycol was again administered twice daily (500 ml/day) on days 10, 11 and 12. Palpation per rectum and ovarian ultrasonography were performed every other day from days 0 to 10, and daily after PGF2α administration until the subsequent ovulation (second ovulation) for analysis of follicular and luteal dynamics. Blood samples were also collected every other day from days 0 to 10, and then at 6 h intervals after PGF2α administration until the second ovulation. For the samples taken at 6-h intervals after PGF2α administration, the concentrations of glucose showed clear daily fluctuations in both groups. Changes in the plasma concentration of glucose in the treatment group were significantly (P < 0.05) higher than those of the control groups during the period between 0 and 72 h after PGF2α administration. No significant difference was detected in the growth of dominant follicles, maximum diameter of the ovulatory follicles and the changes in oestradiol and progesterone during the follicular phase between treatment and control groups. This study showed the clear daily fluctuations and stimulatory changes in the blood glucose concentrations at 24-h intervals during the short-term treatment of propylene glycol drenching in heifers. However, no significant changes in ovarian and hormonal dynamics were found under such metabolic conditions.

Modeling of the Nano- and Picoseismicity Rate Changes Resulting from Static Stress Triggering due to Small (MW2.2) Event Recorded at Mponeng Deep Gold Mine, South Africa

NASA Astrophysics Data System (ADS)

Kozlowska, M.; Orlecka-Sikora, B.; Kwiatek, G.; Boettcher, M. S.; Dresen, G. H.

2014-12-01

Static stress changes following large earthquakes are known to affect the rate and spatio-temporal distribution of the aftershocks. Here we utilize a unique dataset of M ≥ -3.4 earthquakes following a MW 2.2 earthquake in Mponeng gold mine, South Africa, to investigate this process for nano- and pico- scale seismicity at centimeter length scales in shallow, mining conditions. The aftershock sequence was recorded during a quiet interval in the mine and thus enabled us to perform the analysis using Dietrich's (1994) rate and state dependent friction law. The formulation for earthquake productivity requires estimation of Coulomb stress changes due to the mainshock, the reference seismicity rate, frictional resistance parameter, and the duration of aftershock relaxation time. We divided the area into six depth intervals and for each we estimated the parameters and modeled the spatio-temporal patterns of seismicity rates after the stress perturbation. Comparing the modeled patterns of seismicity with the observed distribution we found that while the spatial patterns match well, the rate of modeled aftershocks is lower than the observed rate. To test our model, we used four metrics of the goodness-of-fit evaluation. Testing procedure allowed rejecting the null hypothesis of no significant difference between seismicity rates only for one depth interval containing the mainshock, for the other, no significant differences have been found. Results show that mining-induced earthquakes may be followed by a stress relaxation expressed through aftershocks located on the rupture plane and in regions of positive Coulomb stress change. Furthermore, we demonstrate that the main features of the temporal and spatial distribution of very small, mining-induced earthquakes at shallow depths can be successfully determined using rate- and state-based stress modeling.

Three-dimensional elastic-plastic finite-element analysis of fatigue crack propagation

NASA Technical Reports Server (NTRS)

Goglia, G. L.; Chermahini, R. G.

1985-01-01

Fatigue cracks are a major problem in designing structures subjected to cyclic loading. Cracks frequently occur in structures such as aircraft and spacecraft. The inspection intervals of many aircraft structures are based on crack-propagation lives. Therefore, improved prediction of propagation lives under flight-load conditions (variable-amplitude loading) are needed to provide more realistic design criteria for these structures. The main thrust was to develop a three-dimensional, nonlinear, elastic-plastic, finite element program capable of extending a crack and changing boundary conditions for the model under consideration. The finite-element model is composed of 8-noded (linear-strain) isoparametric elements. In the analysis, the material is assumed to be elastic-perfectly plastic. The cycle stress-strain curve for the material is shown Zienkiewicz's initial-stress method, von Mises's yield criterion, and Drucker's normality condition under small-strain assumptions are used to account for plasticity. The three-dimensional analysis is capable of extending the crack and changing boundary conditions under cyclic loading.

Visible micro-Raman spectroscopy of single human mammary epithelial cells exposed to x-ray radiation.

PubMed

Delfino, Ines; Perna, Giuseppe; Lasalvia, Maria; Capozzi, Vito; Manti, Lorenzo; Camerlingo, Carlo; Lepore, Maria

2015-03-01

A micro-Raman spectroscopy investigation has been performed in vitro on single human mammary epithelial cells after irradiation by graded x-ray doses. The analysis by principal component analysis (PCA) and interval-PCA (i-PCA) methods has allowed us to point out the small differences in the Raman spectra induced by irradiation. This experimental approach has enabled us to delineate radiation-induced changes in protein, nucleic acid, lipid, and carbohydrate content. In particular, the dose dependence of PCA and i-PCA components has been analyzed. Our results have confirmed that micro-Raman spectroscopy coupled to properly chosen data analysis methods is a very sensitive technique to detect early molecular changes at the single-cell level following exposure to ionizing radiation. This would help in developing innovative approaches to monitor radiation cancer radiotherapy outcome so as to reduce the overall radiation dose and minimize damage to the surrounding healthy cells, both aspects being of great importance in the field of radiation therapy.

Methods of Stochastic Analysis of Complex Regimes in the 3D Hindmarsh-Rose Neuron Model

NASA Astrophysics Data System (ADS)

Bashkirtseva, Irina; Ryashko, Lev; Slepukhina, Evdokia

A problem of the stochastic nonlinear analysis of neuronal activity is studied by the example of the Hindmarsh-Rose (HR) model. For the parametric region of tonic spiking oscillations, it is shown that random noise transforms the spiking dynamic regime into the bursting one. This stochastic phenomenon is specified by qualitative changes in distributions of random trajectories and interspike intervals (ISIs). For a quantitative analysis of the noise-induced bursting, we suggest a constructive semi-analytical approach based on the stochastic sensitivity function (SSF) technique and the method of confidence domains that allows us to describe geometrically a distribution of random states around the deterministic attractors. Using this approach, we develop a new algorithm for estimation of critical values for the noise intensity corresponding to the qualitative changes in stochastic dynamics. We show that the obtained estimations are in good agreement with the numerical results. An interplay between noise-induced bursting and transitions from order to chaos is discussed.

Reduced short interval cortical inhibition correlates with atomoxetine response in children with attention-deficit hyperactivity disorder (ADHD).

PubMed

Chen, Tina H; Wu, Steve W; Welge, Jeffrey A; Dixon, Stephan G; Shahana, Nasrin; Huddleston, David A; Sarvis, Adam R; Sallee, Floyd R; Gilbert, Donald L

2014-12-01

Clinical trials in children with attention-deficit hyperactivity disorder (ADHD) show variability in behavioral responses to the selective norepinephrine reuptake inhibitor atomoxetine. The objective of this study was to determine whether transcranial magnetic stimulation-evoked short interval cortical inhibition might be a biomarker predicting, or correlating with, clinical atomoxetine response. At baseline and after 4 weeks of atomoxetine treatment in 7- to 12-year-old children with ADHD, transcranial magnetic stimulation short interval cortical inhibition was measured, blinded to clinical improvement. Primary analysis was by multivariate analysis of covariance. Baseline short interval cortical inhibition did not predict clinical responses. However, paradoxically, after 4 weeks of atomoxetine, mean short interval cortical inhibition was reduced 31.9% in responders and increased 6.1% in nonresponders (analysis of covariance t 41 = 2.88; P = .0063). Percentage reductions in short interval cortical inhibition correlated with reductions in the ADHD Rating Scale (r = 0.50; P = .0005). In children ages 7 to 12 years with ADHD treated with atomoxetine, improvements in clinical symptoms are correlated with reductions in motor cortex short interval cortical inhibition. © The Author(s) 2014.

Palaeoenvironmental changes during the Danian-Selandian boundary interval: The ichnological record at the Sopelana section (Basque Basin, W Pyrenees)

NASA Astrophysics Data System (ADS)

Rodríguez-Tovar, F. J.; Uchman, A.; Orue-Etxebarria, X.; Apellaniz, E.

2013-02-01

Ichnological analysis was conducted in the Danian-Selandian (D-S) boundary interval from the Sopelana section (Basque Basin, northern Spain) to improve characterization of the recently defined Global Stratotype Section and Point of the base of the Selandian Stage (Middle Paleocene) in the nearby Zumaia section, and to interpret the Danian-Selandian boundary event with its associated palaeoenvironmental changes. The trace fossil assemblage of the boundary interval is relatively scarce and shows low diversity, consisting of Chondrites, Planolites, Thalassinoides, Trichichnus and Zoophycos, which cross-cut a diffuse, burrow-mottled background, typical of a normal burrowing tiered community. Distribution of trace fossils shows local drops in abundance and diversity just above the D-S boundary and about half a metre upwards into the succeeding Selandian. Generally, the Selandian part of the section has slightly lower trace fossil diversity and abundance. This is interpreted as due to a higher detrital food supply, corresponding to a sea-level fall, in contrast to a decreased food supply during the Selandian sea-level rise. Smaller-scale fluctuations of trace fossil diversity and abundance are also interpreted as due more to food content fluctuations in the sediment than to oxygenation of pore waters. Results reveal the minor influence of an extreme warming event (hyperthermal conditions) at the D-S boundary which affected the whole benthic habitat. Contrarily, a probable major effect of sea-level fluctuations can be envisaged, which determined variations in siliciclastic input and food content.

Assessment of cardiac autonomic regulation and ventricular repolarization after off-pump coronary artery bypass grafting.

PubMed

Kalisnik, Jurij M; Avbelj, Viktor; Trobec, Roman; Ivaskovic, Daroslav; Vidmar, Gaj; Troise, Giovanni; Gersak, Borut

2006-01-01

Altered autonomic regulation precipitates cardiac arrhythmias and increases the risk of sudden cardiac death. This risk is further increased by changes in ventricular repolarization. Autonomic regulation is deranged in patients after myocardial on-pump revascularization. We aimed to clarify how off-pump coronary artery bypass grafting (CABG) affects postoperative cardiac autonomic regulation and ventricular repolarization within 4 weeks after CABG. Forty-two patients (mean age, 61.9 +/- 9.3 years; mean EURO score 2.6 +/- 1.9) were electively admitted for off-pump CABG. The electrocardiographic and respiratory waveform recordings were performed in the afternoon in the supine position for 10 minutes. Autonomic modulation was assessed using heart rate variability analysis. Power spectra were computed from 5-minute stable RR intervals using Fourier Transform analysis. Total power of spectra was defined in the range of 0.01 to 0.40 Hz, high-frequency power within 0.15 to 0.40 Hz, and low-frequency power within 0.04 to 0.15 Hz. Normalized power was defined as a ratio of power in each band/total power. The high- and low-frequency power as well as their normalized values indicated cardiac vagal and sympathetic modulation, respectively. Ventricular repolarization was assessed using QT interval, QT interval variability, and QT-RR interdependence analysis. QT intervals were determined from the beginning of the 5-minute segments. QT interval variability was evaluated by a T-wave template-matching algorithm. Pearson correlation between length of RR and QT interval was applied to study QT-RR characteristics. The results were tested for significance using the Fisher exact test, nonpaired t test, and analysis of variance; a P <.05 was considered significant. The frequency of arrhythmic events and heart rate increased from the fourth to the seventh postoperative day and returned to preoperative levels 4 weeks after CABG. Heart rate variability measures indicating autonomic modulation remained depressed even 4 weeks after the procedure. QT variability index increased from -1.2 +/- 0.5 to -0.8 +/- 0.4 on the fourth day after the operation (P <.05) and returned to -1.0 +/- 0.5 4 weeks after CABG (P = not significant). QT-RR correlation decreased from 0.41 to 0.23 (P <.05) and remained significantly impaired as long as 4 weeks after CABG. Observed faster heart rates until 1 week after off-pump CABG imply excessive adrenergic activation, which is comparable to on-pump CABG procedure rates. The results indicate profound autonomic derangement and loss of rate-dependent regulation after off-pump CABG even 4 weeks after operation. Restituted repolarization as assessed by QT variability index 4 weeks postoperatively corresponded with decreased frequency of rhythm disturbances 4 weeks after CABG. The loss of coupling between QT and RR intervals shows increased electrical instability postoperatively, which may serve as an additional promoter for postoperative arrhythmias, especially at higher heart rates.

Analysis of Interval Changes on Mammograms for Computer Aided Diagnosis

DTIC Science & Technology

2000-05-01

tizer was calibrated so that the gray values were linearly and erage pixel values in the template and ROI, respectively. The inversely proportional to the...earlier for linearly and inversely proportional to the OD within the alignment of the breast regions, except that the regions to be range 0-4 OD...results versely proportional to the radial distance r from the nipple. in a decrease in the value of (to 20 mm. This decrease helps For the data set

Experimental Analysis of Heat Transfer Characteristics and Pressure Drop through Screen Regenerative Heat Exchangers

DTIC Science & Technology

1993-12-01

of fluid T1 initial temperature of matrix and fluid Tf1 average inlet temperature after the step change Tii average inlet temperature before the step...respectively, of the regenerator. The horizontal distances shown with Tf1 , Tj, and T,2 illustrate the time interval for which the average values were...temperature was not a true step function, the investigator made an approximation. The approximation was based on an average temperature. Tf1 was the

Simulation of streamflows and basin-wide hydrologic variables over several climate-change scenarios, Methow River basin, Washington

USGS Publications Warehouse

Voss, Frank D.; Mastin, Mark C.

2012-01-01

A database was developed to automate model execution and to provide users with Internet access to voluminous data products ranging from summary figures to model output timeseries. Database-enabled Internet tools were developed to allow users to create interactive graphs of output results based on their analysis needs. For example, users were able to create graphs by selecting time intervals, greenhouse gas emission scenarios, general circulation models, and specific hydrologic variables.

Analgzing long-term changes in vegetation with geographic information system and remotely sensed data

NASA Astrophysics Data System (ADS)

Iverson, Louis R.; Risser, Paul G.

Geographic information systems and remote sensing techniques are powerful tools in the analysis of long-term changes in vegetation and land use, especially because spatial information from two or more time intervals can be compared more readily than by manual methods. A primary restriction is the paucity of data that has been digitized from earlier periods. The Illinois State Geographic Information System has a number of automated data sets containing land-use information, including original land survey plat maps that show the boundaries of forests, prairies, and wetlands as they existed prior to European colonization in the early 1800s. More recent data include the United States Forest Service inventories of 1948, 1962, and 1985; the United States Geological Survey Land Use Data Analysis; National High Altitude Program photographs of vegetation; and Landsat MSS and TM information. These data can be used to compare vegetation patterns and changes in land use over time and to suggest factors that may have caused or influenced these variations. Profound changes have occurred in the Illinois landscape since European settlement, primarily because of conversion to agricultural use; in certain parts of the state, however, urbanization has been the major factor contributing to changes.

Long-term Stability and Reliability of Baseline Cognitive Assessments in High School Athletes Using ImPACT at 1-, 2-, and 3-year Test-Retest Intervals.

PubMed

Brett, Benjamin L; Smyk, Nathan; Solomon, Gary; Baughman, Brandon C; Schatz, Philip

2016-08-18

The ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) neurocognitive testing battery is a widely used tool used for the assessment and management of sports-related concussion. Research on the stability of ImPACT in high school athletes at a 1- and 2-year intervals have been inconsistent, requiring further investigation. We documented 1-, 2-, and 3-year test-retest reliability of repeated ImPACT baseline assessments in a sample of high school athletes, using multiple statistical methods for examining stability. A total of 1,510 high school athletes completed baseline cognitive testing using online ImPACT test battery at three time periods of approximately 1- (N = 250), 2- (N = 1146), and 3-year (N = 114) intervals. No participant sustained a concussion between assessments. Intraclass correlation coefficients (ICCs) ranged in composite scores from 0.36 to 0.90 and showed little change as intervals between assessments increased. Reliable change indices and regression-based measures (RBMs) examining the test-retest stability demonstrated a lack of significant change in composite scores across the various time intervals, with very few cases (0%-6%) falling outside of 95% confidence intervals. The results suggest ImPACT composites scores remain considerably stability across 1-, 2-, and 3-year test-retest intervals in high school athletes, when considering both ICCs and RBM. Annually ascertaining baseline scores continues to be optimal for ensuring accurate and individualized management of injury for concussed athletes. For instances in which more recent baselines are not available (1-2 years), clinicians should seek to utilize more conservative range estimates in determining the presence of clinically meaningful change in cognitive performance. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Postlung transplant survival is equivalent regardless of cytomegalovirus match status.

PubMed

Russo, Mark J; Sternberg, David I; Hong, Kimberly N; Sorabella, Robert A; Moskowitz, Alan J; Gelijns, Annetine C; Wilt, Jessie R; D'Ovidio, Frank; Kawut, Steve M; Arcasoy, Selim M; Sonett, Joshua R

2007-10-01

The purpose of this study was to assess (1) the relationship between donor-recipient cytomegalovirus (CMV) serologic status and posttransplant survival in the current era and (2) temporal changes in posttransplant survival by CMV matching status. De-identified data were obtained from the United Network for Organ Sharing. Based on pretransplant CMV serologic status (+ or -) of recipients (R) and donors (D), posttransplant survival was compared among three groups: D+ /R-, D+/- /R+, and D- /R-. Primary analysis focused on transplants performed January 1, 2000 to December 31, 2004, in recipients 18 years of age or older. To assess temporal trends in survival among groups, all lung transplants occurring between January 1, 1990, and December 31, 2004, were considered and divided into three periods based on transplant year: 1990 through 1994, 1995 through 1999, and 2000 through 2004. The primary outcome measure was survival, reported as rate of death per 100 patient-years. Kaplan-Meier analysis with log-rank test was used for time-to-event analysis. During the current era (2000 through 2004), D+ /R- (n = 951), D+/- /R+ (n = 2,676), and D- /R- (n = 772) exhibited no differences in survival (p = 0.561), with rates of death per 100 patient-years of 16.6 (95% confidence interval, 14.9 to 18.5), 15.0 (95% confidence interval, 14.0 to 16.0), and 14.7 (95% confidence interval, 13.0 to 16.6), respectively. However, survival was significantly different for groups in the earlier eras of 1990 through 1994 (p < 0.001) and 1995 through 1999 (p < 0.001). During the three periods, survival improved significantly in D+ /R- (p < 0.001) and D+/- /R+ (p < 0.001), but survival in D- /R- (p = 0.351) did not change significantly with time. In the current era, survival after lung transplantation is statistically equivalent regardless of CMV match status. Although in previous eras survival was worse among the D+/- /R+ and D+ /R- groups, in this era of aggressive CMV prophylaxis, CMV mismatch should not be sufficient grounds to decline a lung allograft offer.

Short-term and long-term effects of dipeptidyl peptidase-4 inhibitors in type 2 diabetes mellitus patients with renal impairment: a meta-analysis of randomized controlled trials.

PubMed

Li, Ruifei; Wang, Rui; Li, Haixia; Sun, Sihao; Zou, Meijuan; Cheng, Gang

2016-09-01

To assess the short-term and long-term effects of dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes mellitus patients with renal impairment, a meta-analysis of randomized clinical trials of DPP-4 inhibitor interventions in type 2 diabetes mellitus patients with renal impairment was performed. PubMed, Embase, Cochrane Library and ClinicalTrials.gov were searched through the end of March 2015. Randomized clinical trials were selected if (1) DPP-4 inhibitors were compared with a placebo or other active-comparators, (2) the treatment duration was ≥12 weeks and (3) data regarding changes in haemoglobin A1c (HbA1c ), changes in fasting plasma glucose or hypoglycaemia and other adverse events were reported. Of 790 studies, ten studies on eight randomized clinical trials were included. Compared with the control group, DPP-4 inhibitors were associated with a greater HbA1c reduction in both the short-term [mean differences (MD) = -0.45, 95% confidence intervals (-0.57, -0.33), p < 0.0001] and long-term [MD = -0.33, 95% confidence intervals (-0.63, -0.03), p = 0.03] treatments. However, the long-term greater reduction in HbA1c with DPP-4 inhibitor treatment was only significant when the control treatment comprised placebo plus stable background treatment, but not glipizide plus stable background treatment. DPP-4 inhibitors were associated with a greater fasting plasma glucose reduction [MD = -12.59, 95% confidence intervals (-22.01, -3.17), p = 0.009] over the short-term; however, this effect was not present over the long-term. Regarding the hypoglycaemia adverse events assessment, the long-term treatment data indicated there was no increased risk of hypoglycaemia compared with placebo or active-controlled anti-diabetic drugs. The present meta-analysis confirms that DPP-4 inhibitors are effective and equivalent to other agents in type 2 diabetes mellitus patients with renal impairment. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of 4 Weeks of High-Intensity Interval Training and β-Hydroxy-β-Methylbutyric Free Acid Supplementation on the Onset of Neuromuscular Fatigue.

PubMed

Miramonti, Amelia A; Stout, Jeffrey R; Fukuda, David H; Robinson, Edward H; Wang, Ran; La Monica, Michael B; Hoffman, Jay R

2016-03-01

This study investigated the effects of high-intensity interval training (HIIT) and β-hydroxy-β-methylbutyric free acid (HMB) supplementation on physical working capacity at the onset of neuromuscular fatigue threshold (PWC(FT)). Thirty-seven participants (22 men, 15 women; 22.8 ± 3.4 years) completed an incremental cycle ergometer test (graded exercise test [GXT]); electromyographic amplitude from the right vastus lateralis was recorded. Assessments occurred preceding (PRE) and after 4 weeks of supplementation (POST). Participants were randomly assigned to control (C, n = 9), placebo (P, n = 14), or supplementation (S, n = 14) groups. Both P and S completed 12 HIIT sessions, whereas C maintained normal diet and activity patterns. The PWC(FT) (W) was determined using the maximal perpendicular distance (D(MAX)) method. Electromyographic amplitude (μVrms) over time was used to generate a cubic regression. Onset of fatigue (TF) was the x-value of the point on the regression that was at D(MAX) from a line between the first and last data points. The PWC(FT) was estimated using TF and GXT power-output increments. The 2-way analysis of variance (ANOVA) (group × time) resulted in a significant interaction for PWC(FT) (F = 6.69, p = 0.004). Post hoc analysis with 1-way ANOVA resulted in no difference in PWC(FT) among groups at PRE (F = 0.87, p = 0.43); however, a difference in PWC(FT) was shown for POST (F = 5.46, p = 0.009). Post hoc analysis among POST values revealed significant differences between S and both P (p = 0.034) and C (p = 0.003). No differences (p = 0.226) were noted between P and C. Paired samples t-tests detected significant changes after HIIT for S (p < 0.001) and P (p = 0.016), but no change in C (p = 0.473). High-intensity interval training increased PWC(FT), but HMB with HIIT was more effective than HIIT alone. Furthermore, it seems that adding HMB supplementation with HIIT in untrained men and women may further improve endurance performance measures.

A single-dose, crossover, placebo- and moxifloxacin-controlled study to assess the effects of neratinib (HKI-272) on cardiac repolarization in healthy adult subjects.

PubMed

Hug, Bruce; Abbas, Richat; Leister, Cathie; Burns, Jaime; Sonnichsen, Daryl

2010-08-01

Neratinib is an orally administered, small-molecule, irreversible pan-ErbB inhibitor in development for the treatment of ErbB2-positive breast cancer. This study assessed the effects of therapeutic and supratherapeutic neratinib concentrations on cardiac repolarization, in accordance with current regulatory guidance. This was a two-part study in healthy subjects. In part 1, subjects were randomized to receive placebo, 400 mg moxifloxacin, or 240 mg neratinib (therapeutic dose) following a high-fat meal. In part 2, after a washout period, subjects received placebo plus 400 mg ketoconazole or 240 mg neratinib plus ketoconazole (supratherapeutic dose). ANOVA was used to compare the baseline-adjusted QTc interval for neratinib with that of placebo (reference), and for neratinib plus ketoconazole with that of placebo plus ketoconazole (reference). Pharmacokinetic/pharmacodynamic analyses and categorical summaries of interval data were done. Assay sensitivity was evaluated by the effect of moxifloxacin on QTc compared with placebo. Sixty healthy subjects were enrolled in this study. The upper bounds of the 90% confidence interval for baseline-adjusted QTcN (population-specific corrected QT) were 450 milliseconds or change from baseline >30 milliseconds. Moxifloxacin produced a significant increase in QTcN compared with placebo (P < 0.05). Therapeutic and supratherapeutic plasma concentrations of neratinib do not prolong the QTc interval in healthy subjects. (c) 2010 AACR.

Venetoclax does not prolong the QT interval in patients with hematological malignancies: an exposure-response analysis.

PubMed

Freise, Kevin J; Dunbar, Martin; Jones, Aksana K; Hoffman, David; Enschede, Sari L Heitner; Wong, Shekman; Salem, Ahmed Hamed

2016-10-01

Venetoclax (ABT-199/GDC-0199) is a selective first-in-class B cell lymphoma-2 inhibitor being developed for the treatment of hematological malignancies. The aim of this study was to determine the potential of venetoclax to prolong the corrected QT (QTc) interval and to evaluate the relationship between systemic venetoclax concentration and QTc interval. The study population included 176 male and female patients with relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (n = 105) or non-Hodgkin's lymphoma (n = 71) enrolled in a phase 1 safety, pharmacokinetic, and efficacy study. Electrocardiograms were collected in triplicate at time-matched points (2, 4, 6, and 8 h) prior to the first venetoclax administration and after repeated venetoclax administration to achieve steady state conditions. Venetoclax doses ranged from 100 to 1200 mg daily. Plasma venetoclax samples were collected after steady state electrocardiogram measurements. The mean and upper bound of the 2-sided 90 % confidence interval (CI) QTc change from baseline were <5 and <10 ms, respectively, at all time points and doses (<400, 400, and >400 mg). Three subjects had single QTc values >500 ms and/or ΔQTc > 60 ms. The effect of venetoclax concentration on both ΔQTc and QTc was not statistically significant (P > 0.05). At the mean maximum concentrations achieved with therapeutic (400 mg) and supra-therapeutic (1200 mg) venetoclax doses, the estimated drug effects on QTc were 0.137 (90 % CI [-1.01 to 1.28]) and 0.263 (90 % CI [-1.92 to 2.45]) ms, respectively. Venetoclax does not prolong QTc interval even at supra-therapeutic doses, and there is no relationship between venetoclax concentrations and QTc interval.

Cost Effectiveness of Age-Specific Screening Intervals for People With Family Histories of Colorectal Cancer.

PubMed

Naber, Steffie K; Kuntz, Karen M; Henrikson, Nora B; Williams, Marc S; Calonge, Ned; Goddard, Katrina A B; Zallen, Doris T; Ganiats, Theodore G; Webber, Elizabeth M; Janssens, A Cecile J W; van Ballegooijen, Marjolein; Zauber, Ann G; Lansdorp-Vogelaar, Iris

2018-01-01

Relative risk of colorectal cancer (CRC) decreases with age among individuals with a family history of CRC. However, no screening recommendations specify less frequent screening with increasing age. We aimed to determine whether such a refinement would be cost effective. We determined the relative risk for CRC for individuals based on age and number of affected first-degree relatives (FDRs) using data from publications. For each number of affected FDRs, we used the Microsimulation Screening Analysis model to estimate costs and effects of colonoscopy screening strategies with different age ranges and intervals. Screening was then optimized sequentially, starting with the youngest age group, and allowing the interval of screening to change at certain ages. Strategies with an incremental cost effectiveness ratio below $100,000 per quality-adjusted life year were considered cost effective. For people with 1 affected FDR (92% of those with a family history), screening every 3 years beginning at an age of 40 years is most cost effective. If no adenomas are found, the screening interval can gradually be extended to 5 and 7 years, at ages 45 and 55 years, respectively. From a cost-effectiveness perspective, individuals with more affected FDRs should start screening earlier and at shorter intervals. However, frequency can be reduced if no abnormalities are found. Using a microsimulation model, we found that for individuals with a family history of CRC, it is cost effective to gradually increase the screening interval if several subsequent screening colonoscopies have negative results and no new cases of CRC are found in family members. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Confidence intervals for population allele frequencies: the general case of sampling from a finite diploid population of any size.

PubMed

Fung, Tak; Keenan, Kevin

2014-01-01

The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%), a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L.), occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.

Estimating age from the pubic symphysis: A new component-based system.

PubMed

Dudzik, Beatrix; Langley, Natalie R

2015-12-01

The os pubis is one of the most widely used areas of the skeleton for age estimation. Current pubic symphyseal aging methods for adults combine the morphology associated with the developmental changes that occur into the mid-30s with the degenerative changes that span the latter portion of the age spectrum. The most popular methods are phase-based; however, the definitions currently used to estimate age intervals may not be adequately defined and/or accurately understood by burgeoning researchers and seasoned practitioners alike. This study identifies patterns of growth and maturation in the pubic symphysis to derive more precise age estimates for individuals under 40 years of age. Emphasis is placed on young adults to provide more informative descriptions of epiphyseal changes associated with the final phases of skeletal maturation before degeneration commences. This study investigated macroscopic changes in forensically relevant modern U.S. samples of known age, sex, and ancestry from the Maricopa County Forensic Science Center in Phoenix, Arizona as well as donated individuals from the William M. Bass Forensic and Donated Collections at the University of Tennessee, Knoxville (n=237). Age-related traits at locations with ontogenetic and biomechanical relevance were broken into components and scored. The components included the pubic tubercle, the superior apex of the face, the ventral and dorsal demifaces, and the ventral and dorsal symphyseal margins. Transition analysis was applied to elucidate the transition ages between the morphological states of each component. The categorical scores and transition analysis ages were subjected to multinomial logistic regression and decision tree analysis to derive accurate age interval estimates. Results of these analyses were used to construct a decision tree-style flow chart for practitioner use. High inter-rater agreement of the individual component traits (linear weighted kappa values ≥0.665 for all traits in the decision tree) indicates that the method offers unambiguous scoring for age-related changes of the pubic symphysis. Validation of the flow chart on a sample of 47 individuals provided by the Montana State Crime Lab yielded 94% accuracy overall, indicating that the method has the potential to deliver precise and accurate age estimates of individuals prior to the onset of advanced degenerative changes. A pubic symphysis that exhibits epiphyseal changes and/or billowing is suitable for this method; a pubic symphysis that exhibits degenerative changes (i.e. porosity and/or rim erosion) is not suitable. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Weighted regression analysis and interval estimators

Treesearch

Donald W. Seegrist

1974-01-01

A method for deriving the weighted least squares estimators for the parameters of a multiple regression model. Confidence intervals for expected values, and prediction intervals for the means of future samples are given.

Interval analysis of interictal EEG: pathology of the alpha rhythm in focal epilepsy

NASA Astrophysics Data System (ADS)

Pyrzowski, Jan; Siemiński, Mariusz; Sarnowska, Anna; Jedrzejczak, Joanna; Nyka, Walenty M.

2015-11-01

The contemporary use of interictal scalp electroencephalography (EEG) in the context of focal epilepsy workup relies on the visual identification of interictal epileptiform discharges. The high-specificity performance of this marker comes, however, at a cost of only moderate sensitivity. Zero-crossing interval analysis is an alternative to Fourier analysis for the assessment of the rhythmic component of EEG signals. We applied this method to standard EEG recordings of 78 patients divided into 4 subgroups: temporal lobe epilepsy (TLE), frontal lobe epilepsy (FLE), psychogenic nonepileptic seizures (PNES) and nonepileptic patients with headache. Interval-analysis based markers were capable of effectively discriminating patients with epilepsy from those in control subgroups (AUC~0.8) with diagnostic sensitivity potentially exceeding that of visual analysis. The identified putative epilepsy-specific markers were sensitive to the properties of the alpha rhythm and displayed weak or non-significant dependences on the number of antiepileptic drugs (AEDs) taken by the patients. Significant AED-related effects were concentrated in the theta interval range and an associated marker allowed for identification of patients on AED polytherapy (AUC~0.9). Interval analysis may thus, in perspective, increase the diagnostic yield of interictal scalp EEG. Our findings point to the possible existence of alpha rhythm abnormalities in patients with epilepsy.

The interaction between cannabis use and the Val158Met polymorphism of the COMT gene in psychosis: A transdiagnostic meta - analysis.

PubMed

Vaessen, Thomas Stephanus Johannes; de Jong, Lea; Schäfer, Annika Theresia; Damen, Thomas; Uittenboogaard, Aniek; Krolinski, Pauline; Nwosu, Chinyere Vicky; Pinckaers, Florentina Maria Egidius; Rotee, Iris Leah Marije; Smeets, Antonius Petrus Wilhelmus; Ermiş, Ayşegül; Kennedy, James L; Nieman, Dorien H; Tiwari, Arun; van Os, Jim; Drukker, Marjan

2018-01-01

Neither environmental nor genetic factors are sufficient to predict the transdiagnostic expression of psychosis. Therefore, analysis of gene-environment interactions may be productive. A meta-analysis was performed using papers investigating the interaction between cannabis use and catechol-O-methyl transferase (COMT) polymorphism Val158Met (COMTVal158Met). PubMed, Embase, PsychInfo. All observational studies assessing the interaction between COMTVal158Met and cannabis with any psychosis or psychotic symptoms measure as an outcome. A meta-analysis was performed using the Meta-analysis of Observational Studies in Epidemiology guidelines and forest plots were generated. Thirteen articles met the selection criteria: 7 clinical studies using a case-only design, 3 clinical studies with a dichotomous outcome, and 3 studies analysing a continuous outcome of psychotic symptoms below the threshold of psychotic disorder. The three study types were analysed separately. Validity of the included studies was assessed using "A Cochrane Risk of Bias Assessment Tool: for Non-Randomized Studies of Interventions". For case-only studies, a significant interaction was found between cannabis use and COMTVal158Met, with an OR of 1.45 (95% Confidence Interval = 1.05-2.00; Met/Met as the risk genotype). However, there was no evidence for interaction in either the studies including dichotomous outcomes (B = -0.51, 95% Confidence Interval -1.72, 0.70) or the studies including continuous outcomes (B = -0.04 95% Confidence Interval -0.16-0.08). A substantial part of the included studies used the case-only design, which has lower validity and tends to overestimate true effects. The interaction term between cannabis use and COMTVal158Met was only statistically significant in the case-only studies, but not in studies using other clinical or non-clinical psychosis outcomes. Future additional high quality studies might change current perspectives, yet currently evidence for the interaction remains unconvincing.

Environmental changes in the Tule Lake basin, Siskiyou and Modoc Counties, California, from 3 to 2 million years before present

USGS Publications Warehouse

Adam, David P.; Bradbury, J. Platt; Rieck, Hugh J.; Sarna-Wojcicki, Andrei M.

1990-01-01

Pollen and diatom analyses of a core from the town of Tulelake, Siskiyou County, California, for the period between 3 and 2 Ma reveal a paleoclimatic and paleolimnologic sequence recording a long, warm time interval that lasted from about 2.9 to 2.6 Ma and had a short, cooler interval within it. During this warm interval, the regional vegetation surrounding ancient Tule Lake was a mixed coniferous forest, and Tule Lake was a warm monomictic lake. Approximate modern analogs for this Pliocene fossil record at Tulelake are found at least 2 degrees farther south. The Tulelake warm interval appears to have correlatives in the North Atlantic oxygen isotope record and in the pollen record of the Reuverian in the Netherlands. An interval beginning at about 2.4 Ma was characterized at Tule Lake by slow sedimentation, by changes in the relative amounts of algae in the lake, and by an increase in the maximum percentages of Artemisia pollen.

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2010-05-17

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Talofibular interval changes after acute ankle sprain: a stress ultrasonography study of ankle laxity.

PubMed

Croy, Theodore; Saliba, Susan; Saliba, Ethan; Anderson, Mark W; Hertel, Jay

2013-11-01

Quantifying talocrural joint laxity after ankle sprain is problematic. Stress ultrasonography (US) can image the lateral talocrural joint and allow the measurement of the talofibular interval, which may suggest injury to the anterior talofibular ligament (ATFL). The acute talofibular interval changes after lateral ankle sprain are unknown. Twenty-five participants (9 male, 16 female; age 21.8 ± 3.2 y, height 167.8 ± 34.1 cm, mass 72.7 ± 13.8 kg) with 27 acute, lateral ankle injuries underwent bilateral stress US imaging at baseline (<7 d) and on the affected ankle at 3 wk and 6 wk from injury in 3 ankle conditions: neutral, anterior drawer, and inversion. Talofibular interval (mm) was measured using imaging software and self-reported function (activities of daily living [ADL] and sports) by the Foot and Ankle Ability Measure (FAAM). The talofibular interval increased with anterior-drawer stress in the involved ankle (22.65 ± 3.75 mm; P = .017) over the uninvolved ankle (19.45 ± 2.35 mm; limb × position F1,26 = 4.9, P = .035) at baseline. Inversion stress also resulted in greater interval changes (23.41 ± 2.81 mm) than in the uninvolved ankles (21.13 ± 2.08 mm). A main effect for time was observed for inversion (F2,52 = 4.3, P = .019, 21.93 ± 2.24 mm) but not for anterior drawer (F2,52 = 3.1, P = .055, 21.18 ± 2.34 mm). A significant reduction in the talofibular interval took place between baseline and week 3 inversion measurements only (F1,26 = 5.6, P = .026). FAAM-ADL and sports results increased significantly from baseline to wk 3 (21.9 ± 16.2, P < .0001 and 23.8 ± 16.9, P < .0001) and from wk 3 to wk 6 (2.5 ± 4.4, P = .009 and 10.5 ± 13.2, P = .001). Stress US methods identified increased talofibular interval changes suggestive of talocrural laxity and ATFL injury using anterior drawer and inversion stress that, despite significant improvements in self-reported function, only marginally improved during the 6 wk after ankle sprain. Stress US provides a safe, repeatable, and quantifiable method of measuring the talofibular interval and may augment manual stress examinations in acute ankle injuries.

Interval sampling methods and measurement error: a computer simulation.

PubMed

Wirth, Oliver; Slaven, James; Taylor, Matthew A

2014-01-01

A simulation study was conducted to provide a more thorough account of measurement error associated with interval sampling methods. A computer program simulated the application of momentary time sampling, partial-interval recording, and whole-interval recording methods on target events randomly distributed across an observation period. The simulation yielded measures of error for multiple combinations of observation period, interval duration, event duration, and cumulative event duration. The simulations were conducted up to 100 times to yield measures of error variability. Although the present simulation confirmed some previously reported characteristics of interval sampling methods, it also revealed many new findings that pertain to each method's inherent strengths and weaknesses. The analysis and resulting error tables can help guide the selection of the most appropriate sampling method for observation-based behavioral assessments. © Society for the Experimental Analysis of Behavior.

Meta-Analysis of Cell-based CaRdiac stUdiEs (ACCRUE) in patients with acute myocardial infarction based on individual patient data.

PubMed

Gyöngyösi, Mariann; Wojakowski, Wojciech; Lemarchand, Patricia; Lunde, Ketil; Tendera, Michal; Bartunek, Jozef; Marban, Eduardo; Assmus, Birgit; Henry, Timothy D; Traverse, Jay H; Moyé, Lemuel A; Sürder, Daniel; Corti, Roberto; Huikuri, Heikki; Miettinen, Johanna; Wöhrle, Jochen; Obradovic, Slobodan; Roncalli, Jérome; Malliaras, Konstantinos; Pokushalov, Evgeny; Romanov, Alexander; Kastrup, Jens; Bergmann, Martin W; Atsma, Douwe E; Diederichsen, Axel; Edes, Istvan; Benedek, Imre; Benedek, Theodora; Pejkov, Hristo; Nyolczas, Noemi; Pavo, Noemi; Bergler-Klein, Jutta; Pavo, Imre J; Sylven, Christer; Berti, Sergio; Navarese, Eliano P; Maurer, Gerald

2015-04-10

The meta-Analysis of Cell-based CaRdiac study is the first prospectively declared collaborative multinational database, including individual data of patients with ischemic heart disease treated with cell therapy. We analyzed the safety and efficacy of intracoronary cell therapy after acute myocardial infarction (AMI), including individual patient data from 12 randomized trials (ASTAMI, Aalst, BOOST, BONAMI, CADUCEUS, FINCELL, REGENT, REPAIR-AMI, SCAMI, SWISS-AMI, TIME, LATE-TIME; n=1252). The primary end point was freedom from combined major adverse cardiac and cerebrovascular events (including all-cause death, AMI recurrance, stroke, and target vessel revascularization). The secondary end point was freedom from hard clinical end points (death, AMI recurrence, or stroke), assessed with random-effects meta-analyses and Cox regressions for interactions. Secondary efficacy end points included changes in end-diastolic volume, end-systolic volume, and ejection fraction, analyzed with random-effects meta-analyses and ANCOVA. We reported weighted mean differences between cell therapy and control groups. No effect of cell therapy on major adverse cardiac and cerebrovascular events (14.0% versus 16.3%; hazard ratio, 0.86; 95% confidence interval, 0.63-1.18) or death (1.4% versus 2.1%) or death/AMI recurrence/stroke (2.9% versus 4.7%) was identified in comparison with controls. No changes in ejection fraction (mean difference: 0.96%; 95% confidence interval, -0.2 to 2.1), end-diastolic volume, or systolic volume were observed compared with controls. These results were not influenced by anterior AMI location, reduced baseline ejection fraction, or the use of MRI for assessing left ventricular parameters. This meta-analysis of individual patient data from randomized trials in patients with recent AMI revealed that intracoronary cell therapy provided no benefit, in terms of clinical events or changes in left ventricular function. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01098591. © 2015 American Heart Association, Inc.

State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students

PubMed Central

Dimitriev, Aleksey D.

2016-01-01

Objectives Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. Methods A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger’s State-Trait Anxiety Inventory was used to assess the level of SA. Results Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. Conclusions The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation. PMID:26807793

Effects of Guideline and Formulary Changes on Statin Prescribing in the Veterans Affairs.

PubMed

Markovitz, Adam A; Holleman, Rob G; Hofer, Timothy P; Kerr, Eve A; Klamerus, Mandi L; Sussman, Jeremy B

2017-12-01

To compare the effects of two sequential policy changes-the addition of a high-potency statin to the Department of Veterans Affairs (VA) formulary and the release of the American College of Cardiology/American Heart Association (ACC/AHA) cholesterol guidelines-on VA provider prescribing. Retrospective analysis of 1,100,682 VA patients, 2011-2016. Interrupted time-series analysis of changes in prescribing of moderate-to-high-intensity statins among high-risk patients and across high-risk subgroups. We also assessed changes in prescribing of atorvastatin and other statin drugs. We estimated marginal effects (ME) of formulary and guideline changes by comparing predicted and observed statin use. Data from VA Corporate Data Warehouse. The use of moderate-to-high-intensity statins increased by 2 percentage points following the formulary change (ME, 2.4, 95% confidence interval [CI], 2.2 to 2.6) and less than 1 percentage point following the guideline change (ME, 0.8, 95% CI, 0.6 to 0.9). The formulary change led to approximately a 12 percentage-point increase in the use of moderate-to-high-intensity atorvastatin (ME, 11.5, 95% CI, 11.3 to 11.6). The relatively greater provider response to the formulary change occurred across all patient subgroups. Addition of a high-potency statin to formulary affected provider prescribing more than the ACC/AHA guidelines. © Health Research and Educational Trust.

Sedimentological and Stable Isotope Changes at the Messinian-Pliocene Boundary Along a West to East Mediterranean Transect.

NASA Astrophysics Data System (ADS)

Pierre, C.; Rouchy, J.; Blanc-Valleron, M.

2001-12-01

During Messinian times, the whole Mediterranean area was submitted to evaporitic conditions which ended by the "Lago-Mare" brackish episode before the reset of open marine conditions in the early Pliocene. These major paleoceanographic changes resulted from regional tectonic reorganizations and global climate changes at this critical time interval, both acting to modify drastically the physiography and the hydrological budget of the Mediterranean basins. There exist outcropping sections and a few deep-sea ODP cores which contain the complete and continuous sedimentary sequence of the Messinian-Pliocene boundary (MPB), making it possible to follow the paleoenvironmental changes at a high resolution scale. We compare here sedimentological and carbonate stable isotope records on three sections for which a high- resolution sampling was applied to the 2 meters thick interval including the MPB. In the Vera section from South Spain, there is no clear change in the carbonate content of the silty clay succession when crossing the MPB. The oxygen and carbon isotopic compositions of calcite both increase by 1 permil across a 40 cm-thick interval which corresponds to the Messinian-Pliocene transition. At ODP Site 968 from the eastern Levantine basin, there is an important sedimentary change between Messinian brown silty clays containing about 20 percent of carbonate and Pliocene gray nannofossil ooze which carbonate content averages 60 percent. Across this 10 cm-thick transitional interval, the oxygen and carbon isotopic compositions of bulk calcite both increase by 4.5 permil. In the Pissouri section from Cyprus, the uppermost Messinian reddish to brown marls with paleosoils are overlain by white Pliocene marls. The carbonate content increases from 20 percent to reach 60 percent across a 40 cm-thick transitional interval. Within this interval corresponding to the MPB, the oxygen and carbon isotopic compositions increase by 4 permil and 2 permil respectively. These results indicate that the MPB is recorded everywhere from W to E Mediterranean by significant and sharp increases in the oxygen and carbon isotopic compositions, which indicate that the early Pliocene marine flooding of the Mediterranean basins was a very abrupt event.

A leaf wax biomarker record of early Pleistocene hydroclimate from West Turkana, Kenya

NASA Astrophysics Data System (ADS)

Lupien, R. L.; Russell, J. M.; Feibel, C.; Beck, C.; Castañeda, I.; Deino, A.; Cohen, A. S.

2018-04-01

Climate is thought to play a critical role in human evolution; however, this hypothesis is difficult to test due to a lack of long, high-quality paleoclimate records from key hominin fossil locales. To address this issue, we analyzed organic geochemical indicators of climate in a drill core from West Turkana, Kenya that spans ∼1.9-1.4 Ma, an interval that includes several important hominin evolutionary transitions. We analyzed the hydrogen isotopic composition of terrestrial plant waxes (δDwax) to reconstruct orbital-timescale changes in regional hydrology and their relationship with global climate forcings and the hominin fossil record. Our data indicate little change in the long-term mean hydroclimate during this interval, in contrast to inferred changes in the level of Lake Turkana, suggesting that lake level may be responding dominantly to deltaic progradation or tectonically-driven changes in basin configuration as opposed to hydroclimate. Time-series spectral analyses of the isotopic data reveal strong precession-band (21 kyr) periodicity, indicating that regional hydroclimate was strongly affected by changes in insolation. We observe an interval of particularly high-amplitude hydrologic variation at ∼1.7 Ma, which occurs during a time of high orbital eccentricity hence large changes in processionally-driven insolation amplitude. This interval overlaps with multiple hominin species turnovers, the appearance of new stone tool technology, and hominin dispersal out of Africa, supporting the notion that climate variability played an important role in hominin evolution.

Low dose aspirin as adjuvant treatment for venous leg ulceration: pragmatic, randomised, double blind, placebo controlled trial (Aspirin4VLU).

PubMed

Jull, Andrew; Wadham, Angela; Bullen, Chris; Parag, Varsha; Kerse, Ngaire; Waters, Jill

2017-11-24

Objective  To determine the effect of low dose aspirin on ulcer healing in patients with venous leg ulcers. Design  Pragmatic, community based, parallel group, double blind, randomised controlled trial. Setting  Five community nursing centres in New Zealand. Participants  251 adults with venous leg ulcers who could safely be treated with aspirin or placebo: 125 were randomised to aspirin and 126 to placebo. Interventions  150 mg oral aspirin daily or matching placebo for up to 24 weeks treatment, with compression therapy as standard background treatment. Main outcome measures  The primary outcome was time to complete healing of the reference ulcer (largest ulcer if more than one ulcer was present). Secondary outcomes included proportion of participants healed, change in ulcer area, change in health related quality of life, and adverse events. Analysis was by intention to treat. Results  The median number of days to healing of the reference ulcer was 77 in the aspirin group and 69 in the placebo group (hazard ratio 0.85, 95% confidence interval 0.64 to 1.13, P=0.25). The number of participants healed at the endpoint was 88 (70%) in the aspirin group and 101 (80%) in the placebo group (risk difference -9.8%, 95% confidence interval -20.4% to 0.9%, P=0.07). Estimated change in ulcer area was 4.1 cm 2 in the aspirin group and 4.8 cm 2 in the placebo group (mean difference -0.7 cm 2 , 95% confidence interval -1.9 to 0.5 cm 2 , P=0.25). 40 adverse events occurred among 29 participants in the aspirin group and 37 adverse events among 27 participants in the placebo group (incidence rate ratio 1.1, 95% confidence interval 0.7 to 1.7, P=0.71). Conclusion  Our findings do not support the use of low dose aspirin as adjuvant treatment for venous leg ulcers. Trial registration  ClinicalTrials.gov NCT02158806. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Formation MicroScanner (FMS) data and orbital cycle records: preliminary interpretation from the Asian Monsoon IODP Expedition 346

NASA Astrophysics Data System (ADS)

Johanna, Lofi; Grizel, Jimenez Soto; Ryuji, Tada; Murray Richard, W.; Alvarez Zarikian Carlos, A.; Martin, Ziegler

2015-04-01

Recently, IODP Expedition 346 (29 July-27 September 2013) drilled seven sites in in the marginal sea bordered by the Eurasian continent, the Korean Peninsula, and the Japanese Islands, as well as two closely spaced sites in the East China Sea. Expedition 346 was the first scientific drilling expedition ever to focus exclusively on the climate system in this region. During the expedition, the Formation MicroScanner (FMS) downhole logging tool was deployed, providing high-resolution electrical resistivity-based images of borehole walls. Features such as bedding, slump folding and bioturbation can be resolved. Here we analyze FMS image resistivity data collected at Site U1425 that extend back to the Miocene. Analysis allowed the recognition of several FMS intervals, with vertical extension ranging from several tens of centimeters to a few meters, with an apparent cyclicity. These FMS intervals correlate well with other downhole logs (Total Gamma Ray, Uranium, Thorium, Potassium and density). Conductive intervals generally correlate with low gamma ray and low density log values. Conversely, more resistive intervals generally correlate with higher values in the gamma ray and bulk density logs. This relationship can be interpreted in terms of the relative abundance of terrigenous clay/diatoms in the sediment. Clay has high K and Th contents and relatively higher density and lower porosity than higher diatom-rich sediment. Consequently, with the exception of sporadic ash and dolomite layers, conductive intervals in the FMS images tend to reflect intervals enriched in diatoms, whereas resistive intervals reflect relative high-terrigenous clay content. An apparent cyclic nature, with several orders of cycles on the FMS images, is locally clearly observed. The cyclic pattern consists of ~4-8 m thick resistive intervals alternating with conductive intervals, generally correlating in core with laminated (diatomite or carbonate rich) intervals. These conductive intervals often contain higher frequency, smaller scale interbedded layers. The transition between resistive and conductive intervals is marked by an intermediate level of medium conductivity in the FMS images, possibly indicating relative changes in productivity conditions. The FMS images have been interpreted in term of FMS facies (low, medium, high conductivity) and their thickness measured along a 100-m long interval since the late Miocene. Vertical changes in thickness of FMS facies are plotted vs. depth, and we propose an attempt of orbital tuning based on the Site U1425 preliminary age model. In the future, the FMS data will be compared to other proxies measured on cores, and physical and chemical properties of sediments such as color reflectance or XRF data. This research project is undertaken as part of IODP Expedition 346. IODP Expedition 346 Scientists: W.T. Anderson, M.-A. Bassetti, B.J. Brace, S.C. Clemens, G.R. Dickens, A.G. Dunlea, S.J. Gallagher, L.Giosan, M.H. da Costa Gurgel, A.C.G. Henderson, A.E. Holbourn, K. Ikehara, T. Irino, T. Itaki, A. Karasuda, C.W. Kinsley, Y. Kubota, G.S. Lee, K.E. Lee, C.I.C.D. Lopes, M. Saavedra Pellitero, L.C. Peterson, T. Sagawa, R.K. Singh, S. Sugisaki, S. Toucanne, S. Wan, C. Xuan, H. Zheng, C.H. Lee

Climate changes in south western Iberia and Mediterranean Outflow variations during two contrasting cycles of the last 1 Myrs: MIS 31-MIS 30 and MIS 12-MIS 11

NASA Astrophysics Data System (ADS)

Sánchez Goñi, M. F.; Llave, E.; Oliveira, D.; Naughton, F.; Desprat, S.; Ducassou, E.; Hodell, D. A.; Hernández-Molina, F. J.

2016-01-01

Grain size analysis and physical properties of Sites U1388, U1389 and U1390 collected in the Contourite Depositional System of the Gulf of Cádiz during the Integrated Ocean Drilling Program (IODP) Expedition 339 "Mediterranean Outflow" reveal relative changes in bottom current strength, a tracer of the dynamics of the Mediterranean Outflow Water (MOW), before and after the Middle Pleistocene Transition (MPT). The comparison of MOW behavior with climate changes identified by the pollen analysis and δ18O benthic foraminifera measurements of Site U1385, the Shackleton Site, collected in the south western Iberian margin shows that the interval MIS 31-MIS 30, ~ 1.1-1.05 million years ago (Ma), before the MPT, was marked by wetter climate and weaker bottom current than the interval MIS 12-MIS 11 (0.47-0.39 Ma), after the MPT. Similarly, the increase in fine particles from these glacials to interglacials and in coarse fraction from interglacials to glacials was coeval with forest and semi-desert expansions, respectively, indicating the lowering/enhancement of MOW strength during periods of regional increase/decrease of moisture. While these findings may not necessarily apply to all glacial/interglacial cycles, they nonetheless serve as excellent supporting examples of the hypothesis that aridification can serve as a good tracer for MOW intensity. The strongest regional aridity during MIS 12 coincides with a remarkable increase of coarse grain size deposition and distribution that we interpret as a maximum in MOW strength. This MOW intensification may have pre-conditioned the North Atlantic by increasing salinity, thereby triggering the strong resumption of the Meridional Overturning Circulation that could contribute to the great warmth that characterizes the MIS 11c super-interglacial.

The Impact of a Social Marketing Campaign on HIV and Sexually Transmissible Infection Testing Among Men Who Have Sex With Men in Australia.

PubMed

Wilkinson, Anna L; Pedrana, Alisa E; El-Hayek, Carol; Vella, Alyce M; Asselin, Jason; Batrouney, Colin; Fairley, Christopher K; Read, Tim R H; Hellard, Margaret; Stoové, Mark

2016-01-01

In response to increasing HIV and other sexually transmissible infection (HIV/STI) notifications in Australia, a social marketing campaign Drama Downunder (DDU) was launched in 2008 to promote HIV/STI testing among men who have sex with men (MSM). We analyzed prospective data from (1) an online cohort of MSM and (2) clinic-level HIV/STI testing to evaluate the impact of DDU on HIV, syphilis, gonorrhea, and chlamydia testing. (1) Cohort participants who completed 3 surveys (2010-2014) contributed to a Poisson regression model examining predictors of recent HIV testing.(2) HIV, syphilis, gonorrhea, and chlamydia tests among MSM attending high caseload primary care clinics (2007-2013) were included in an interrupted time series analysis. (1) Although campaign awareness was high among 242 MSM completing 726 prospective surveys, campaign recall was not associated with self-reported HIV testing. Reporting previous regular HIV testing (adjusted incidence rate ratio, 2.4; 95% confidence interval, 1.3-4.4) and more than 10 partners in the previous 6 months (adjusted incidence rate ratio, 1.2; 95% confidence interval, 1.1-1.4) was associated with recent HIV testing. (2) Analysis of 257,023 tests showed increasing monthly HIV, syphilis, gonorrhea, and chlamydia tests pre-DDU. Post-DDU, gonorrhea test rates increased significantly among HIV-negative MSM, with modest and nonsignificant increasing rates of HIV, syphilis, and chlamydia testing. Among HIV-positive MSM, no change in gonorrhea or chlamydia testing occurred and syphilis testing declined significantly. Increasing HIV/STI testing trends among MSM occurred pre- and post-DDU, coinciding with other plausible drivers of testing. Modest changes in HIV testing post-DDU suggest that structural changes to improve testing access may need to occur alongside health promotion to increase testing frequency.

Safety, Feasibility, and Efficacy of Vagus Nerve Stimulation Paired With Upper-Limb Rehabilitation After Ischemic Stroke.

PubMed

Dawson, Jesse; Pierce, David; Dixit, Anand; Kimberley, Teresa J; Robertson, Michele; Tarver, Brent; Hilmi, Omar; McLean, John; Forbes, Kirsten; Kilgard, Michael P; Rennaker, Robert L; Cramer, Steven C; Walters, Matthew; Engineer, Navzer

2016-01-01

Recent animal studies demonstrate that vagus nerve stimulation (VNS) paired with movement induces movement-specific plasticity in motor cortex and improves forelimb function after stroke. We conducted a randomized controlled clinical pilot study of VNS paired with rehabilitation on upper-limb function after ischemic stroke. Twenty-one participants with ischemic stroke >6 months before and moderate to severe upper-limb impairment were randomized to VNS plus rehabilitation or rehabilitation alone. Rehabilitation consisted of three 2-hour sessions per week for 6 weeks, each involving >400 movement trials. In the VNS group, movements were paired with 0.5-second VNS. The primary objective was to assess safety and feasibility. Secondary end points included change in upper-limb measures (including the Fugl-Meyer Assessment-Upper Extremity). Nine participants were randomized to VNS plus rehabilitation and 11 to rehabilitation alone. There were no serious adverse device effects. One patient had transient vocal cord palsy and dysphagia after implantation. Five had minor adverse device effects including nausea and taste disturbance on the evening of therapy. In the intention-to-treat analysis, the change in Fugl-Meyer Assessment-Upper Extremity scores was not significantly different (between-group difference, 5.7 points; 95% confidence interval, -0.4 to 11.8). In the per-protocol analysis, there was a significant difference in change in Fugl-Meyer Assessment-Upper Extremity score (between-group difference, 6.5 points; 95% confidence interval, 0.4 to 12.6). This study suggests that VNS paired with rehabilitation is feasible and has not raised safety concerns. Additional studies of VNS in adults with chronic stroke will now be performed. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01669161. © 2015 The Authors.

Safety, Feasibility, and Efficacy of Vagus Nerve Stimulation Paired With Upper-Limb Rehabilitation After Ischemic Stroke

PubMed Central

Pierce, David; Dixit, Anand; Kimberley, Teresa J.; Robertson, Michele; Tarver, Brent; Hilmi, Omar; McLean, John; Forbes, Kirsten; Kilgard, Michael P.; Rennaker, Robert L.; Cramer, Steven C.; Walters, Matthew; Engineer, Navzer

2016-01-01

Background and Purpose— Recent animal studies demonstrate that vagus nerve stimulation (VNS) paired with movement induces movement-specific plasticity in motor cortex and improves forelimb function after stroke. We conducted a randomized controlled clinical pilot study of VNS paired with rehabilitation on upper-limb function after ischemic stroke. Methods— Twenty-one participants with ischemic stroke >6 months before and moderate to severe upper-limb impairment were randomized to VNS plus rehabilitation or rehabilitation alone. Rehabilitation consisted of three 2-hour sessions per week for 6 weeks, each involving >400 movement trials. In the VNS group, movements were paired with 0.5-second VNS. The primary objective was to assess safety and feasibility. Secondary end points included change in upper-limb measures (including the Fugl–Meyer Assessment-Upper Extremity). Results— Nine participants were randomized to VNS plus rehabilitation and 11 to rehabilitation alone. There were no serious adverse device effects. One patient had transient vocal cord palsy and dysphagia after implantation. Five had minor adverse device effects including nausea and taste disturbance on the evening of therapy. In the intention-to-treat analysis, the change in Fugl–Meyer Assessment-Upper Extremity scores was not significantly different (between-group difference, 5.7 points; 95% confidence interval, −0.4 to 11.8). In the per-protocol analysis, there was a significant difference in change in Fugl–Meyer Assessment-Upper Extremity score (between-group difference, 6.5 points; 95% confidence interval, 0.4 to 12.6). Conclusions— This study suggests that VNS paired with rehabilitation is feasible and has not raised safety concerns. Additional studies of VNS in adults with chronic stroke will now be performed. Clinical Trial Registration— URL: https://www.clinicaltrials.gov. Unique identifier: NCT01669161. PMID:26645257

The effect of interval tubal sterilization on sexual interest and pleasure.

PubMed

Costello, Caroline; Hillis, Susan D; Marchbanks, Polly A; Jamieson, Denise J; Peterson, Herbert B

2002-09-01

To determine if interval tubal sterilization leads to a change in female sexual interest or pleasure and to identify predictors of a positive or negative effect. Our study population comprised 4576 women enrolled in a prospective, multicenter cohort study between 1978 and 1983. Potential demographic, clinical, and surgical predictors of sexual outcome were tested for significant variation from the overall pattern of unchanged, increased, and decreased sexual interest and pleasure. Over 80% of the 4576 study women reported no consistent change in either sexual interest (80.0%) or pleasure (81.7%) after interval tubal sterilization. Among women with consistent change, positive effects were reported ten and 15 times more often than negative effects for sexual interest and pleasure, respectively. All subgroups of women, except for those with poststerilization regret, were significantly (P <.05) more likely to experience increased rather than decreased interest or pleasure. Women with poststerilization regret were the subgroup most likely to have a negative effect; in multivariate analyses, poststerilization regret was the only factor to be a predictor for decreased interest (odds ratio 4.0) and decreased pleasure (odds ratio 5.1). Similarly, women reporting regret were significantly less likely to report increased interest or pleasure. Whether the regret or the decreased sexual interest or pleasure occurred first is unclear. Interval tubal ligation is unlikely to result in changed sexual interest or pleasure. Among those with change, the majority experienced positive sexual effects.

Bond strength comparison of 2 self-etching primers over a 3-month storage period.

PubMed

Trites, Brian; Foley, Timothy F; Banting, David

2004-12-01

The purpose of this in vitro study was to evaluate the shear-peel bond strength of 2 self-etching primer systems, Transbond Plus (3M/ Unitek, Monrovia, Calif) and First Step (Reliance Orthodontic Products, Itasca, Ill), with their respective adhesives, and compare them with a control adhesive system (Transbond XT, 3M/ Unitek) over a 3-month period. Two hundred seventy extracted human premolars were obtained and randomly divided into 9 groups of 30 teeth. Metal orthodontic brackets were bonded to the enamel, and each adhesive group was stored for 24 horrs (T1), 30 days (T2), or 3 months (T3) in deionized water at 37 degrees C. All bonded specimens were thermocycled at 10 degrees C and 50 degrees C for 24 hours before debonding. Brackets were debonded by using a shear-peel load on a testing machine at a cross-head speed of 2 mm/min. Bond failure was also evaluated. The shear-peel bond strengths of the 3 bonding systems were clinically acceptable with the possible exception of First Step at 30-day storage. Repeated measures analysis of variance showed a statistically significant (P < .0001) difference in mean bond strengths between the 3 adhesive systems. The shear-peel bond strength of the adhesives over the 3 time intervals showed statistically significant (P = .005) changes. In each group, there were statistically significant differences in shear-peel bond strength between time intervals T1-T2 and T2-T3 for Transbond Plus and T2-T3 for First Step. The change in mean shear-peel bond strength of the 3 adhesives demonstrated a consistent pattern of behavior over the 3 storage intervals. The lowest mean shear-peel bond strength values were noted at the 30-day storage. Bond failure analysis (adhesive remnant index) demonstrated mainly cohesive bond failures.

Depositional History of a Saline Blue Hole on Eleuthera Island, Bahamas: Implications for Sea Level History and Climate Change

NASA Astrophysics Data System (ADS)

Brady, K.; Bernard, M.; Bender, S.; Roy, Z.; Boush, L. E.; Myrbo, A.; Brown, E. T.; Buynevich, I. V.; Berman, M.; Gnivecki, P.

2013-12-01

Physical, chemical and biological properties of Duck Pond Blue Hole (DPBH), located on the southern portion of Eleuthera Island, Bahamas, were examined to analyze its depositional history and the record of climate and anthropogenic changes on the island. DPBH is a small (.001 km2), circular inland blue hole with average salinity ranging from 20-28 ppt and a maximum depth of ~8 m. Sediment cores were recovered using standard piston coring techniques along a transect consisting of three sites yielding cores of varying lengths--170, 155 and 151 cm, respectively. Radiocarbon dating, x-ray fluorescence (XRF), grain size analysis, loss on ignition (LOI), smear slide and mollusk processing and identification were performed on the cores. The sediment recovered is dominated by brown, tan and white carbonate sand with varying amounts of organic matter. Sedimentation rates vary between 0.1-0.5 mm/year. Mollusks are found throughout the cores but gastropods dominate in the upper portions, which date from 2000 years BP to present day. Bivalves are abundant in intervals dating between 5000 and 2500 years BP. The most common bivalve species were Polymesoda maritima, Anomalocardis auberiana and Ervilia concentrica. The most common gastropods were Cerithidea costata and Cerithium lutosum. Drill holes made by predaceous gastropods occur on some of the gastropods, but on most of the bivalves. Drilling frequency is highest between 5000 and 2500 years BP even though gastropods are rarely preserved in that interval. Through smear slide analysis, diatoms, forams and ostracodes were also found to occur throughout the core record. Peaks in Fe and Sr from XRF scans at 0.5 cm intervals may represent records of high atmospheric dust concentrations and sea level fluctuations, respectively. Plotting mollusk bed depths versus calibrated age reveals a sea level rise over the last 6000 years that includes a rapid rise and subsequent fall at ~2500 year BP.

A physical function test for use in the intensive care unit: validity, responsiveness, and predictive utility of the physical function ICU test (scored).

PubMed

Denehy, Linda; de Morton, Natalie A; Skinner, Elizabeth H; Edbrooke, Lara; Haines, Kimberley; Warrillow, Stephen; Berney, Sue

2013-12-01

Several tests have recently been developed to measure changes in patient strength and functional outcomes in the intensive care unit (ICU). The original Physical Function ICU Test (PFIT) demonstrates reliability and sensitivity. The aims of this study were to further develop the original PFIT, to derive an interval score (the PFIT-s), and to test the clinimetric properties of the PFIT-s. A nested cohort study was conducted. One hundred forty-four and 116 participants performed the PFIT at ICU admission and discharge, respectively. Original test components were modified using principal component analysis. Rasch analysis examined the unidimensionality of the PFIT, and an interval score was derived. Correlations tested validity, and multiple regression analyses investigated predictive ability. Responsiveness was assessed using the effect size index (ESI), and the minimal clinically important difference (MCID) was calculated. The shoulder lift component was removed. Unidimensionality of combined admission and discharge PFIT-s scores was confirmed. The PFIT-s displayed moderate convergent validity with the Timed "Up & Go" Test (r=-.60), the Six-Minute Walk Test (r=.41), and the Medical Research Council (MRC) sum score (rho=.49). The ESI of the PFIT-s was 0.82, and the MCID was 1.5 points (interval scale range=0-10). A higher admission PFIT-s score was predictive of: an MRC score of ≥48, increased likelihood of discharge home, reduced likelihood of discharge to inpatient rehabilitation, and reduced acute care hospital length of stay. Scoring of sit-to-stand assistance required is subjective, and cadence cutpoints used may not be generalizable. The PFIT-s is a safe and inexpensive test of physical function with high clinical utility. It is valid, responsive to change, and predictive of key outcomes. It is recommended that the PFIT-s be adopted to test physical function in the ICU.

A comparison of hand-wrist bone and cervical vertebral analyses in measuring skeletal maturation.

PubMed

Gandini, Paola; Mancini, Marta; Andreani, Federico

2006-11-01

To compare skeletal maturation as measured by hand-wrist bone analysis and by cervical vertebral analysis. A radiographic hand-wrist bone analysis and cephalometric cervical vertebral analysis of 30 patients (14 males and 16 females; 7-18 years of age) were examined. The hand-wrist bone analysis was evaluated by the Bjork index, whereas the cervical vertebral analysis was assessed by the cervical vertebral maturation stage (CVMS) method. To define vertebral stages, the analysis consisted of both cephalometric (13 points) and morphologic evaluation of three cervical vertebrae (concavity of second, third, and fourth vertebrae and shape of third and fourth vertebrae). These measurements were then compared with the hand-wrist bone analysis, and the results were statistically analyzed by the Cohen kappa concordance index. The same procedure was repeated after 6 months and showed identical results. The Cohen kappa index obtained (mean +/- SD) was 0.783 +/- 0.098, which is in the significant range. The results show a concordance of 83.3%, considering that the estimated percentage for each case is 23.3%. The results also show a correlation of CVMS I with Bjork stages 1-3 (interval A), CVMS II with Bjork stage 4 (interval B), CVMS III with Bjork stage 5 (interval C), CVMS IV with Bjork stages 6 and 7 (interval D), and CVMS V with Bjork stages 8 and 9 (interval E). Vertebral analysis on a lateral cephalogram is as valid as the hand-wrist bone analysis with the advantage of reducing the radiation exposure of growing subjects.

Evaluation of Short-Term Changes in Serum Creatinine Level as a Meaningful End Point in Randomized Clinical Trials

PubMed Central

Zabetian, Azadeh; Ferket, Bart S.; Zhou, Jing; Testani, Jeffrey M.; Garg, Amit X.; Parikh, Chirag R.

2016-01-01

Observational studies have shown that acute change in kidney function (specifically, AKI) is a strong risk factor for poor outcomes. Thus, the outcome of acute change in serum creatinine level, regardless of underlying biology or etiology, is frequently used in clinical trials as both efficacy and safety end points. We performed a meta-analysis of clinical trials to quantify the relationship between positive or negative short–term effects of interventions on change in serum creatinine level and more meaningful clinical outcomes. After a thorough literature search, we included 14 randomized trials of interventions that altered risk for an acute increase in serum creatinine level and had reported between–group differences in CKD and/or mortality rate ≥3 months after randomization. Seven trials assessed interventions that, compared with placebo, increased risk of acute elevation in serum creatinine level (pooled relative risk, 1.52; 95% confidence interval, 1.22 to 1.89), and seven trials assessed interventions that, compared with placebo, reduced risk of acute elevation in serum creatinine level (pooled relative risk, 0.57; 95% confidence interval, 0.44 to 0.74). However, pooled risks for CKD and mortality associated with interventions did not differ from those with placebo in either group. In conclusion, several interventions that affect risk of acute, mild to moderate, often temporary elevation in serum creatinine level in placebo–controlled randomized trials showed no appreciable effect on CKD or mortality months later, raising questions about the value of using small to moderate changes in serum creatinine level as end points in clinical trials. PMID:26712525

Implications of postseismic gravity change following the great 2004 Sumatra-Andaman earthquake from the regional harmonic analysis of GRACE intersatellite tracking data

USGS Publications Warehouse

Han, S.-C.; Sauber, J.; Luthcke, S.B.; Ji, C.; Pollitz., F. F.

2008-01-01

We report Gravity Recovery and Climate Experiment (GRACE) satellite observations of coseismic displacements and postseismic transients from the great Sumatra-Andaman Islands (thrust event; Mw ???9.2) earthquake in December 2004. Instead of using global spherical harmonic solutions of monthly gravity fields, we estimated the gravity changes directly using intersatellite range-rate data with regionally concentrated spherical Slepian basis functions every 15-day interval. We found significant step-like (coseismic) and exponential-like (postseismic) behavior in the time series of estimated coefficients (from May 2003 to April 2007) for the spherical Slepian function's. After deriving coseismic slip estimates from seismic and geodetic data that spanned different time intervals, we estimated and evaluated postseismic relaxation mechanisms with alternate asthenosphere viscosity models. The large spatial coverage and uniform accuracy of our GRACE solution enabled us to clearly delineate a postseismic transient signal in the first 2 years of postearthquake GRACE data. Our preferred interpretation of the long-wavelength components of the postseismic avity change is biviscous viscoelastic flow. We estimated a transient viscosity of 5 ??17 Pa s and a steady state viscosity of 5 ?? 1018 - 1019 Pa s. Additional years of the GRACE observations should provide improved steady state viscosity estimates. In contrast to our interpretation of coseismic gravity change, the prominent postearthquake positive gravity change around the Nicobar Islands is accounted for by seafloor uplift with less postseismic perturbation in intrinsic density in the region surrounding the earthquake. Copyright 2008 by the American Geophysical Union.

Monte Carlo-based interval transformation analysis for multi-criteria decision analysis of groundwater management strategies under uncertain naphthalene concentrations and health risks

NASA Astrophysics Data System (ADS)

Ren, Lixia; He, Li; Lu, Hongwei; Chen, Yizhong

2016-08-01

A new Monte Carlo-based interval transformation analysis (MCITA) is used in this study for multi-criteria decision analysis (MCDA) of naphthalene-contaminated groundwater management strategies. The analysis can be conducted when input data such as total cost, contaminant concentration and health risk are represented as intervals. Compared to traditional MCDA methods, MCITA-MCDA has the advantages of (1) dealing with inexactness of input data represented as intervals, (2) mitigating computational time due to the introduction of Monte Carlo sampling method, (3) identifying the most desirable management strategies under data uncertainty. A real-world case study is employed to demonstrate the performance of this method. A set of inexact management alternatives are considered in each duration on the basis of four criteria. Results indicated that the most desirable management strategy lied in action 15 for the 5-year, action 8 for the 10-year, action 12 for the 15-year, and action 2 for the 20-year management.

The Relationship Between Oxygen Reserve Index and Arterial Partial Pressure of Oxygen During Surgery

PubMed Central

Dorotta, Ihab L.; Wells, Briana; Juma, David; Applegate, Patricia M.

2016-01-01

BACKGROUND: The use of intraoperative pulse oximetry (Spo2) enhances hypoxia detection and is associated with fewer perioperative hypoxic events. However, Spo2 may be reported as 98% when arterial partial pressure of oxygen (Pao2) is as low as 70 mm Hg. Therefore, Spo2 may not provide advance warning of falling arterial oxygenation until Pao2 approaches this level. Multiwave pulse co-oximetry can provide a calculated oxygen reserve index (ORI) that may add to information from pulse oximetry when Spo2 is >98%. This study evaluates the ORI to Pao2 relationship during surgery. METHODS: We studied patients undergoing scheduled surgery in which arterial catheterization and intraoperative arterial blood gas analysis were planned. Data from multiple pulse co-oximetry sensors on each patient were continuously collected and stored on a research computer. Regression analysis was used to compare ORI with Pao2 obtained from each arterial blood gas measurement and changes in ORI with changes in Pao2 from sequential measurements. Linear mixed-effects regression models for repeated measures were then used to account for within-subject correlation across the repeatedly measured Pao2 and ORI and for the unequal time intervals of Pao2 determination over elapsed surgical time. Regression plots were inspected for ORI values corresponding to Pao2 of 100 and 150 mm Hg. ORI and Pao2 were compared using mixed-effects models with a subject-specific random intercept. RESULTS: ORI values and Pao2 measurements were obtained from intraoperative data collected from 106 patients. Regression analysis showed that the ORI to Pao2 relationship was stronger for Pao2 to 240 mm Hg (r2 = 0.536) than for Pao2 over 240 mm Hg (r2 = 0.0016). Measured Pao2 was ≥100 mm Hg for all ORI over 0.24. Measured Pao2 was ≥150 mm Hg in 96.6% of samples when ORI was over 0.55. A random intercept variance component linear mixed-effects model for repeated measures indicated that Pao2 was significantly related to ORI (β[95% confidence interval] = 0.002 [0.0019–0.0022]; P < 0.0001). A similar analysis indicated a significant relationship between change in Pao2 and change in ORI (β [95% confidence interval] = 0.0044 [0.0040–0.0048]; P < 0.0001). CONCLUSIONS: These findings suggest that ORI >0.24 can distinguish Pao2 ≥100 mm Hg when Spo2 is over 98%. Similarly, ORI > 0.55 appears to be a threshold to distinguish Pao2 ≥150 mm Hg. The usefulness of these values should be evaluated prospectively. Decreases in ORI to near 0.24 may provide advance indication of falling Pao2 approaching 100 mm Hg when Spo2 is >98%. The clinical utility of interventions based on continuous ORI monitoring should be studied prospectively. PMID:27007078

The Relationship Between Oxygen Reserve Index and Arterial Partial Pressure of Oxygen During Surgery.

PubMed

Applegate, Richard L; Dorotta, Ihab L; Wells, Briana; Juma, David; Applegate, Patricia M

2016-09-01

The use of intraoperative pulse oximetry (SpO2) enhances hypoxia detection and is associated with fewer perioperative hypoxic events. However, SpO2 may be reported as 98% when arterial partial pressure of oxygen (PaO2) is as low as 70 mm Hg. Therefore, SpO2 may not provide advance warning of falling arterial oxygenation until PaO2 approaches this level. Multiwave pulse co-oximetry can provide a calculated oxygen reserve index (ORI) that may add to information from pulse oximetry when SpO2 is >98%. This study evaluates the ORI to PaO2 relationship during surgery. We studied patients undergoing scheduled surgery in which arterial catheterization and intraoperative arterial blood gas analysis were planned. Data from multiple pulse co-oximetry sensors on each patient were continuously collected and stored on a research computer. Regression analysis was used to compare ORI with PaO2 obtained from each arterial blood gas measurement and changes in ORI with changes in PaO2 from sequential measurements. Linear mixed-effects regression models for repeated measures were then used to account for within-subject correlation across the repeatedly measured PaO2 and ORI and for the unequal time intervals of PaO2 determination over elapsed surgical time. Regression plots were inspected for ORI values corresponding to PaO2 of 100 and 150 mm Hg. ORI and PaO2 were compared using mixed-effects models with a subject-specific random intercept. ORI values and PaO2 measurements were obtained from intraoperative data collected from 106 patients. Regression analysis showed that the ORI to PaO2 relationship was stronger for PaO2 to 240 mm Hg (r = 0.536) than for PaO2 over 240 mm Hg (r = 0.0016). Measured PaO2 was ≥100 mm Hg for all ORI over 0.24. Measured PaO2 was ≥150 mm Hg in 96.6% of samples when ORI was over 0.55. A random intercept variance component linear mixed-effects model for repeated measures indicated that PaO2 was significantly related to ORI (β[95% confidence interval] = 0.002 [0.0019-0.0022]; P < 0.0001). A similar analysis indicated a significant relationship between change in PaO2 and change in ORI (β [95% confidence interval] = 0.0044 [0.0040-0.0048]; P < 0.0001). These findings suggest that ORI >0.24 can distinguish PaO2 ≥100 mm Hg when SpO2 is over 98%. Similarly, ORI > 0.55 appears to be a threshold to distinguish PaO2 ≥150 mm Hg. The usefulness of these values should be evaluated prospectively. Decreases in ORI to near 0.24 may provide advance indication of falling PaO2 approaching 100 mm Hg when SpO2 is >98%. The clinical utility of interventions based on continuous ORI monitoring should be studied prospectively.

Identifying Significant Changes in Cerebrovascular Reactivity to Carbon Dioxide.

PubMed

Sobczyk, O; Crawley, A P; Poublanc, J; Sam, K; Mandell, D M; Mikulis, D J; Duffin, J; Fisher, J A

2016-05-01

Changes in cerebrovascular reactivity can be used to assess disease progression and response to therapy but require discrimination of pathology from normal test-to-test variability. Such variability is due to variations in methodology, technology, and physiology with time. With uniform test conditions, our aim was to determine the test-to-test variability of cerebrovascular reactivity in healthy subjects and in patients with known cerebrovascular disease. Cerebrovascular reactivity was the ratio of the blood oxygen level-dependent MR imaging response divided by the change in carbon dioxide stimulus. Two standardized cerebrovascular reactivity tests were conducted at 3T in 15 healthy men (36.7 ± 16.1 years of age) within a 4-month period and were coregistered into standard space to yield voxelwise mean cerebrovascular reactivity interval difference measures, composing a reference interval difference atlas. Cerebrovascular reactivity interval difference maps were prepared for 11 male patients. For each patient, the test-retest difference of each voxel was scored statistically as z-values of the corresponding voxel mean difference in the reference atlas and then color-coded and superimposed on the anatomic images to create cerebrovascular reactivity interval difference z-maps. There were no significant test-to-test differences in cerebrovascular reactivity in either gray or white matter (mean gray matter, P = .431; mean white matter, P = .857; paired t test) in the healthy cohort. The patient cerebrovascular reactivity interval difference z-maps indicated regions where cerebrovascular reactivity increased or decreased and the probability that the changes were significant. Accounting for normal test-to-test differences in cerebrovascular reactivity enables the assessment of significant changes in disease status (stability, progression, or regression) in patients with time. © 2016 by American Journal of Neuroradiology.

Exercise, adipokines and pediatric obesity: a meta-analysis of randomized controlled trials.

PubMed

García-Hermoso, A; Ceballos-Ceballos, R J M; Poblete-Aro, C E; Hackney, A C; Mota, J; Ramírez-Vélez, R

2017-04-01

Adipokines are involved in the etiology of diabetes, insulin resistance, and the development of atherosclerosis and other latent-onset complications. The objective of this meta-analysis was to determine the effectiveness of exercise interventions on adipokines in pediatric obesity. A computerized search was made using three databases. The analysis was restricted to studies that examined the effect of exercise interventions on adipokines (adiponectin, leptin, resistin and visfatin) in pediatric obesity (6-18 years old). Fourteen randomized controlled trials (347 youths) were included. Weighted mean difference (WMD) and 95% confidence intervals were calculated. Exercise was associated with a significant increase in adiponectin (WMD=0.882 μg ml -1 , 95% CI, 0.271-1.493) but did not alter leptin and resistin level. Likewise, exercise intensity and change in body fat; as well as total exercise program duration, duration of the sessions, and change in body fat all significantly influenced the effect of exercise on adiponectin and leptin, respectively. Exercise seems to increase adiponectin levels in childhood obesity. Our results also suggested that exercise on its own, without the concomitant presence of changes in body composition levels, does not affect leptin levels.

The clinical evaluation of platelet-rich plasma on free gingival graft's donor site wound healing.

PubMed

Samani, Mahmoud Khosravi; Saberi, Bardia Vadiati; Ali Tabatabaei, S M; Moghadam, Mahdjoube Goldani

2017-01-01

It has been proved that platelet-rich plasma (PRP) can promote wound healing. In this way, PRP can be advantageous in periodontal plastic surgeries, free gingival graft (FGG) being one such surgery. In this randomized split-mouth controlled trial, 10 patients who needed bilateral FGG were selected, and two donor sites were randomly assigned to experience either natural healing or healing-assisted with PRP. The outcome was assessed based on the comparison of the extent of wound closure, Manchester scale, Landry healing scale, visual analog scale, and tissue thickness between the study groups at different time intervals. Repeated measurements of analysis of variance and paired t -test were used. Statistical significance was P ≤ 0.05. Significant differences between the study groups and also across different time intervals were seen in all parameters except for the changes in tissue thickness. PRP accelerates the healing process of wounds and reduces the healing time.

Study of Travelling Interplanetary Phenomena (STIP) workshop travel

NASA Technical Reports Server (NTRS)

Wu, S. T.

1986-01-01

Thirty six abstracts are provided from the SCOSTEP/STIP Symposium on Retrospective Analyses and Future Coordinated Intervals held in Switzerland on June 10 to 12, 1985. Six American scientists participated in the symposium and their abstracts are also included. The titles of their papers are: (1) An analysis of near surface and coronal activity during STIP interval 12, by T. E. Gergely; (2) Helios images of STIP intervals 6, B. V. Jackson; (3) Results from the analysis of solar and interplanetary observations during STIP interval 7, S. R. Kane; (4) STIP interval 19, E. Cliver; (5) Hydrodynamic buoyancy force in the solar atmosphere, T. Yeh; and (6) A combined MHD modes for the energy and momentum transport from solar surface to interplanetary space, S. T. Wu.

Acoustic emission characterization of microcracking in laboratory-scale hydraulic fracturing tests

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

Hampton, Jesse; Gutierrez, Marte; Matzar, Luis

Understanding microcracking near coalesced fracture generation is critically important for hydrocarbon and geothermal reservoir characterization as well as damage evaluation in civil engineering structures. Dense and sometimes random microcracking near coalesced fracture formation alters the mechanical properties of the nearby virgin material. Individual microcrack characterization is also significant in quantifying the material changes near the fracture faces (i.e. damage). Acoustic emission (AE) monitoring and analysis provide unique information regarding the microcracking process temporally, and information concerning the source characterization of individual microcracks can be extracted. In this context, laboratory hydraulic fracture tests were carried out while monitoring the AEs frommore » several piezoelectric transducers. In-depth post-processing of the AE event data was performed for the purpose of understanding the individual source mechanisms. Several source characterization techniques including moment tensor inversion, event parametric analysis, and volumetric deformation analysis were adopted. Post-test fracture characterization through coring, slicing and micro-computed tomographic imaging was performed to determine the coalesced fracture location and structure. Distinct differences in fracture characteristics were found spatially in relation to the openhole injection interval. Individual microcrack AE analysis showed substantial energy reduction emanating spatially from the injection interval. Lastly, it was quantitatively observed that the recorded AE signals provided sufficient information to generalize the damage radiating spatially away from the injection wellbore.« less

Acoustic emission characterization of microcracking in laboratory-scale hydraulic fracturing tests

DOE PAGES

Hampton, Jesse; Gutierrez, Marte; Matzar, Luis; ...

2018-06-11

Understanding microcracking near coalesced fracture generation is critically important for hydrocarbon and geothermal reservoir characterization as well as damage evaluation in civil engineering structures. Dense and sometimes random microcracking near coalesced fracture formation alters the mechanical properties of the nearby virgin material. Individual microcrack characterization is also significant in quantifying the material changes near the fracture faces (i.e. damage). Acoustic emission (AE) monitoring and analysis provide unique information regarding the microcracking process temporally, and information concerning the source characterization of individual microcracks can be extracted. In this context, laboratory hydraulic fracture tests were carried out while monitoring the AEs frommore » several piezoelectric transducers. In-depth post-processing of the AE event data was performed for the purpose of understanding the individual source mechanisms. Several source characterization techniques including moment tensor inversion, event parametric analysis, and volumetric deformation analysis were adopted. Post-test fracture characterization through coring, slicing and micro-computed tomographic imaging was performed to determine the coalesced fracture location and structure. Distinct differences in fracture characteristics were found spatially in relation to the openhole injection interval. Individual microcrack AE analysis showed substantial energy reduction emanating spatially from the injection interval. Lastly, it was quantitatively observed that the recorded AE signals provided sufficient information to generalize the damage radiating spatially away from the injection wellbore.« less

What Is the Shape of Developmental Change?

PubMed Central

Adolph, Karen E.; Robinson, Scott R.; Young, Jesse W.; Gill-Alvarez, Felix

2009-01-01

Developmental trajectories provide the empirical foundation for theories about change processes during development. However, the ability to distinguish among alternative trajectories depends on how frequently observations are sampled. This study used real behavioral data, with real patterns of variability, to examine the effects of sampling at different intervals on characterization of the underlying trajectory. Data were derived from a set of 32 infant motor skills indexed daily during the first 18 months. Larger sampling intervals (2-31 days) were simulated by systematically removing observations from the daily data and interpolating over the gaps. Infrequent sampling caused decreasing sensitivity to fluctuations in the daily data: Variable trajectories erroneously appeared as step-functions and estimates of onset ages were increasingly off target. Sensitivity to variation decreased as an inverse power function of sampling interval, resulting in severe degradation of the trajectory with intervals longer than 7 days. These findings suggest that sampling rates typically used by developmental researchers may be inadequate to accurately depict patterns of variability and the shape of developmental change. Inadequate sampling regimes therefore may seriously compromise theories of development. PMID:18729590

Looking into the puparium: Micro-CT visualization of the internal morphological changes during metamorphosis of the blow fly, Calliphora vicina, with the first quantitative analysis of organ development in cyclorrhaphous dipterans.

PubMed

Martín-Vega, Daniel; Simonsen, Thomas J; Hall, Martin J R

2017-05-01

Metamorphosis of cyclorrhaphous flies takes place inside a barrel-like puparium, formed by the shrinking, hardening and darkening of the third-instar larval cuticle. The opacity of this structure hampers the visualization of the morphological changes occurring inside and therefore a full understanding of the metamorphosis process. Here, we use micro-computed tomography (micro-CT) to describe the internal morphological changes that occur during metamorphosis of the blow fly, Calliphora vicina Robineau-Desvoidy 1830 (Diptera: Calliphoridae) at a greater temporal resolution than anything hitherto published. The morphological changes were documented at 10% intervals of the total intra-puparial period, and down to 2.5% intervals during the first 20% interval, when the most dramatic morphological changes occur. Moreover, the development of an internal gas bubble, which plays an essential role during early metamorphosis, was further investigated with X-ray images and micro-CT virtual sections. The origin of this gas bubble has been largely unknown, but micro-CT virtual sections show that it is connected to one of the main tracheal trunks. Micro-CT virtual sections also provided enough resolution for determining the completion of the larval-pupal and pupal-adult apolyses, thus enabling an accurate timing of the different intra-puparial life stages. The prepupal, pupal, and pharate adult stages last for 7.5%, 22.5%, and 70% of the total intra-puparial development, respectively. Furthermore, we provide for the first time quantitative data on the development of two organ systems of the blow fly: the alimentary canal and the indirect flight muscles. There is a significant and negative correlation between the volume of the indirect flight muscles and the pre-helicoidal region of the midgut during metamorphosis. The latter occupies a large portion of the thorax during the pupal stage but narrows progressively as the indirect flight muscles increase in volume during the development of the pharate adult. © 2017 The Authors Journal of Morphology Published by Wiley Periodicals, Inc.

Looking into the puparium: Micro‐CT visualization of the internal morphological changes during metamorphosis of the blow fly, Calliphora vicina, with the first quantitative analysis of organ development in cyclorrhaphous dipterans

PubMed Central

Simonsen, Thomas J.; Hall, Martin J. R.

2017-01-01

Abstract Metamorphosis of cyclorrhaphous flies takes place inside a barrel‐like puparium, formed by the shrinking, hardening and darkening of the third‐instar larval cuticle. The opacity of this structure hampers the visualization of the morphological changes occurring inside and therefore a full understanding of the metamorphosis process. Here, we use micro‐computed tomography (micro‐CT) to describe the internal morphological changes that occur during metamorphosis of the blow fly, Calliphora vicina Robineau‐Desvoidy 1830 (Diptera: Calliphoridae) at a greater temporal resolution than anything hitherto published. The morphological changes were documented at 10% intervals of the total intra‐puparial period, and down to 2.5% intervals during the first 20% interval, when the most dramatic morphological changes occur. Moreover, the development of an internal gas bubble, which plays an essential role during early metamorphosis, was further investigated with X‐ray images and micro‐CT virtual sections. The origin of this gas bubble has been largely unknown, but micro‐CT virtual sections show that it is connected to one of the main tracheal trunks. Micro‐CT virtual sections also provided enough resolution for determining the completion of the larval‐pupal and pupal‐adult apolyses, thus enabling an accurate timing of the different intra‐puparial life stages. The prepupal, pupal, and pharate adult stages last for 7.5%, 22.5%, and 70% of the total intra‐puparial development, respectively. Furthermore, we provide for the first time quantitative data on the development of two organ systems of the blow fly: the alimentary canal and the indirect flight muscles. There is a significant and negative correlation between the volume of the indirect flight muscles and the pre‐helicoidal region of the midgut during metamorphosis. The latter occupies a large portion of the thorax during the pupal stage but narrows progressively as the indirect flight muscles increase in volume during the development of the pharate adult. PMID:28182298

Short-Duration Spaceflight Does Not Prolong QTc Intervals in Male Astronauts

NASA Technical Reports Server (NTRS)

Mitchell, Brett M.; Meck, Janice V.

2004-01-01

Although ventricular dysrhythmias are not increased during, and QTc intervals are not prolonged after, short-duration (5 to 16 days) spaceflights, QTc intervals have not previously been reported during these shorter flights. Holter monitor recordings, obtained in 11 male astronauts who flew on shuttle missions ranging from 5 to 10 days, showed that QTc intervals did not change significantly 10 days before launch, on 2 separate days of spaceflight, and 2 days after landing. Taken together, these data and our previous report show that QTc interval prolongation occurs sometime between the 9th and 30th days of spaceflight.

U.S. Geological Survey shrub/grass products provide new approach to shrubland monitoring

USGS Publications Warehouse

Young, Steven M.

2017-12-11

In the Western United States, shrubland ecosystems provide vital ecological, hydrological, biological, agricultural, and recreational services. However, disturbances such as livestock grazing, exotic species invasion, conversion to agriculture, climate change, urban expansion, and energy development are altering these ecosystems.Improving our understanding of how shrublands are distributed, where they are changing, the extent of the historical change, and likely future change directions is critical for successful management of these ecosystems. Remote-sensing technologies provide the most likely data source for large-area monitoring of ecosystem disturbance—both near-real time and historically. A monitoring framework supported by remote-sensing data can offer efficient and accurate analysis of change across a range of spatial and temporal scales.The U.S. Geological Survey has been working to develop new remote-sensing data, tools, and products to characterize and monitor these changing shrubland landscapes. Nine individual map products (components) have been developed that quantify the percent of shrub, sagebrush, big sagebrush, herbaceous, annual herbaceous, litter, bare ground, shrub height, and sagebrush height at 1-percent intervals in each 30-meter grid cell. These component products are designed to be combined and customized to widely support different applications in rangeland monitoring, analysis of wildlife habitat, resource inventory, adaptive management, and environmental review.

Quantifying grain shape with MorpheoLV: A case study using Holocene glacial marine sediments

NASA Astrophysics Data System (ADS)

Charpentier, Isabelle; Staszyc, Alicia B.; Wellner, Julia S.; Alejandro, Vanessa

2017-06-01

As demonstrated in earlier works, quantitative grain shape analysis has revealed to be a strong proxy for determining sediment transport history and depositional environments. MorpheoLV, devoted to the calculation of roughness coefficients from pictures of unique clastic sediment grains using Fourier analysis, drives computations for a collection of samples of grain images. This process may be applied to sedimentary deposits assuming core/interval/image archives for the storage of samples collected along depth. This study uses a 25.8 m jumbo piston core, NBP1203 JPC36, taken from a 100 m thick sedimentary drift deposit from Perseverance Drift on the northern Antarctic Peninsula continental shelf. Changes in ocean and ice conditions throughout the Holocene recorded in this sedimentary archive can be assessed by studying grain shape, grain texture, and other proxies. Ninety six intervals were sampled and a total of 2319 individual particle images were used. Microtextures of individual grains observed by SEM show a very high abundance of authigenically precipitated silica that obscures the original grain shape. Grain roughness, computed along depth with MorpheoLV, only shows small variation confirming the qualitative observation deduced from the SEM. Despite this, trends can be seen confirming the reliability of MorpheoLV as a tool for quantitative grain shape analysis.

Multi-cluster processor operating only select number of clusters during each phase based on program statistic monitored at predetermined intervals

DOEpatents

Balasubramonian, Rajeev [Sandy, UT; Dwarkadas, Sandhya [Rochester, NY; Albonesi, David [Ithaca, NY

2009-02-10

In a processor having multiple clusters which operate in parallel, the number of clusters in use can be varied dynamically. At the start of each program phase, the configuration option for an interval is run to determine the optimal configuration, which is used until the next phase change is detected. The optimum instruction interval is determined by starting with a minimum interval and doubling it until a low stability factor is reached.

Nonlinear analysis of gait kinematics to track changes in oxygen consumption in prolonged load carriage walking: a pilot study.

PubMed

Schiffman, Jeffrey M; Chelidze, David; Adams, Albert; Segala, David B; Hasselquist, Leif

2009-09-18

Linking human mechanical work to physiological work for the purpose of developing a model of physical fatigue is a complex problem that cannot be solved easily by conventional biomechanical analysis. The purpose of the study was to determine if two nonlinear analysis methods can address the fundamental issue of utilizing kinematic data to track oxygen consumption from a prolonged walking trial: we evaluated the effectiveness of dynamical systems and fractal analysis in this study. Further, we selected, oxygen consumption as a measure to represent the underlying physiological measure of fatigue. Three male US Army Soldier volunteers (means: 23.3 yr; 1.80 m; 77.3 kg) walked for 120 min at 1.34 m/s with a 40-kg load on a level treadmill. Gait kinematic data and oxygen consumption (VO(2)) data were collected over the 120-min period. For the fractal analysis, utilizing stride interval data, we calculated fractal dimension. For the dynamical systems analysis, kinematic angle time series were used to estimate phase space warping based features at uniform time intervals: smooth orthogonal decomposition (SOD) was used to extract slowly time-varying trends from these features. Estimated fractal dimensions showed no apparent trend or correlation with independently measured VO(2). While inter-individual difference did exist in the VO(2) data, dominant SOD time trends tracked and correlated with the VO(2) for all volunteers. Thus, dynamical systems analysis using gait kinematics may be suitable to develop a model to predict physiologic fatigue based on biomechanical work.

Effects of drought and pluvial periods on fish and zooplankton communities in prairie lakes: systematic and asystematic responses.

PubMed

Starks, Elizabeth; Cooper, Ryan; Leavitt, Peter R; Wissel, Björn

2014-04-01

The anticipated impacts of climate change on aquatic biota are difficult to evaluate because of potentially contrasting effects of temperature and hydrology on lake ecosystems, particularly those closed-basin lakes within semiarid regions. To address this shortfall, we quantified decade-scale changes in chemical and biological properties of 20 endorheic lakes in central North America in response to a pronounced transition from a drought to a pluvial period during the early 21st century. Lakes exhibited marked temporal changes in chemical characteristics and formed two discrete clusters corresponding to periods of substantially different effective moisture (as Palmer Drought Severity Index, PDSI). Discriminant function analysis (DFA) explained 90% of variability in fish assemblage composition and showed that fish communities were predicted best by environmental conditions during the arid interval (PDSI <-2). DFA also predicted that lakes could support more fish species during pluvial periods, but their occurrences may be limited by periodic stress due to recurrent droughts and physical barriers to colonization. Zooplankton taxonomic assemblages in fishless lakes were resilient to short-term changes in meteorological conditions, and did not vary between drought and deluge periods. Conversely, zooplankton taxa in fish-populated lakes decreased substantially in biomass during the wet interval, likely due to increased zooplanktivory by fish. The powerful effects of such climatic variability on hydrology and the strong subsequent links to water chemistry and biota indicate that future changes in global climate could result in significant restructuring of aquatic communities. Together these findings suggest that semiarid lakes undergoing temporary climate shifts provide a useful model system for anticipating the effects of global climate change on lake food webs. © 2013 John Wiley & Sons Ltd.

Association between Overall Lifestyle Changes and the Incidence of Proteinuria: A Population-based, Cohort Study

PubMed Central

Wakasugi, Minako; Kazama, Junichiro; Narita, Ichiei; Iseki, Kunitoshi; Fujimoto, Shouichi; Moriyama, Toshiki; Yamagata, Kunihiro; Konta, Tsuneo; Tsuruya, Kazuhiko; Asahi, Koichi; Kondo, Masahide; Kurahashi, Issei; Ohashi, Yasuo; Kimura, Kenjiro; Watanabe, Tsuyoshi

2017-01-01

Objective This study aimed to examine the association between the changes in an overall healthy lifestyle, as quantified by the number of unhealthy lifestyle factors and obesity status, and the incidence of proteinuria in the general Japanese population. Methods A retrospective cohort study was conducted among 99,404 (men, 36.9%) participants aged from 40-74 years of age who underwent two health check-ups with a 1-year interval in Japan between 2008 and 2009. Any participants with chronic kidney disease at baseline were excluded. The smoking status, body mass index, physical activity, alcohol consumption, and healthy eating habits were combined into a simple overall healthy lifestyle score ranging from 0 to 5. The changes in overall healthy lifestyle scores from baseline (range, -5 to +5) and the incidence of proteinuria, defined by a dipstick urinalysis (score ≥1+), were assessed at the second check-up. A logistic regression analysis was used to examine the association between the changes in overall healthy lifestyle scores and the incidence of proteinuria. Results After one year of follow-up, 3.9% of men and 2.4% of women developed proteinuria. Each increase (or decrease) in the changes in overall healthy lifestyle scores was associated with a reduced (or increased) risk of proteinuria in both men (odds ratio (OR) 0.87; 95% confidence interval (CI), 0.81-0.94) and women (OR 0.87; 95%CI, 0.80-0.94) after adjusting for age, baseline lifestyle scores, hypertension, diabetes mellitus, and hypercholesterolemia. Stratified analyses based on age, the presence or absence of hypertension, or diabetes mellitus revealed similar results. Conclusion Overall lifestyle changes, even within a year, were found to influence the incidence of proteinuria. PMID:28626171

75 FR 35113 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

... Stock Market LLC To List Options on Trust Issued Receipts in $1 Strike Intervals June 15, 2010. Pursuant... options on Trust Issued Receipts in $1 strike price intervals. The text of the proposed rule change is...''), as defined in Supplementary Material to Section 6 at .01(b), in $1 or greater strike price intervals...

76 FR 48935 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-09

... the $1 Strike Price Interval Program August 4, 2011. Pursuant to Section 19(b)(1) of the Securities... Proposed Rule Change CBOE proposes to amend its rules in order to simplify the $1 Strike Price Interval... Policy .01 to Rule 5.5 in order to simplify the $1 Strike Price Interval Program (``Program''). In 2003...

A PCT-wide collaborative clinical audit selecting recall intervals for patients according to risk.

PubMed

Cannell, P J

2011-03-26

This audit was carried out to assess the level to which recall intervals were individually and appropriately selected for patients attending dental practices across a primary care trust (PCT) area in Essex. A retrospective audit was carried out by reference to patient records to assess various criteria, including whether patients were categorised according to risk of oral disease, whether an appropriate recall had been selected and whether a discussion regarding a recall interval had been undertaken. An educational event highlighting the issue of recall intervals was held. Subsequent to this a prospective audit was undertaken to assess relevant criteria. Prospective audit data showed a marked increase in the use of patient risk assessments for caries, periodontal disease, oral cancer and non-carious tooth surface loss (NCTSL). Recall intervals were also more often selected based on a patient's risk status and discussed with the patient compared to that observed in the retrospective audit data. This audit was successful as a tool to bring about change in the behaviour of dentists regarding their determination of appropriate recall intervals for patients. Whether that change in behaviour is long-term or transient requires further investigation.

Nontarget-to-nontarget interval determines the nontarget P300 in an auditory equiprobable Go/NoGo task.

PubMed

Steiner, Genevieve Z; Barry, Robert J; Gonsalvez, Craig J

2014-06-01

Increases in the target-to-target interval (TTI) systematically enhance the amplitude of the target P300 ERP component. Research examining changes in nontarget P300 related to nontarget-to-nontarget interval (NNI) or sequential probability manipulations has produced inconsistent results, with some studies reporting no enhancement in nontarget P300 and others finding response profiles analogous to TTI effects. Our aim was to clarify these differences. All participants completed a specially designed auditory equiprobable Go/NoGo task with manipulations of TTI and NNI while their EEG activity was recorded. P300 amplitudes were extracted using temporal PCA with Varimax rotation. P3b to targets and nontargets increased systematically as respective TTIs/NNIs increased, but this change did not differ between stimulus types. The Slow Wave did not show any effect of interval, but was more positive to targets than nontargets when interval was collapsed. P3b findings show that matching-stimulus interval effects are not restricted to targets, but discrepancies relative to previous research suggest that NNI effects in P3b may depend on additional processing of nontarget stimuli. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of personality traits and psychosocial training on burnout syndrome among healthcare students.

PubMed

Skodova, Zuzana; Lajciakova, Petra

2013-11-01

The aims of this paper were to explore the influence of personality factors on student burnout syndrome and to explore the effect of psychosocial training on burnout and personality predictors among university students in health care professions. A quasi-experimental pre-test/post-test design was used to evaluate the effect of psychosocial training. A sample of 111 university students were divided into experimental and control groups (average age 20.7 years, SD=2.8 years; 86.1% females). The School Burnout Inventory (SBI), Sense of Coherence (SOC) questionnaire, and Rosenberg's Self-esteem scale were employed. Linear regression and analysis of variance were applied for statistical analysis. The results show that socio-psychological training had a positive impact on the level of burnout and on personality factors that are related to burnout. After completing the training, the level of burnout in the experimental group significantly decreased (95% confidence interval: 0.93, 9.25), and no significant change was observed in the control group. Furthermore, respondents' sense of coherence increased in the experimental group (95% confidence interval: -9.11, 2.64), but there were no significant changes in respondents' self-esteem levels in either group. Psychosocial training positively influenced burnout among students in health care professions. Because the coping strategies that were used during the study are similar to effective work coping strategies, psychosocial training can be considered to be an effective tool to prevent burnout in the helping professions. Copyright © 2013. Published by Elsevier Ltd.

The meaning of diagnostic test results: a spreadsheet for swift data analysis.

PubMed

Maceneaney, P M; Malone, D E

2000-03-01

To design a spreadsheet program to: (a) analyse rapidly diagnostic test result data produced in local research or reported in the literature; (b) correct reported predictive values for disease prevalence in any population; (c) estimate the post-test probability of disease in individual patients. Microsoft Excel(TM)was used. Section A: a contingency (2 x 2) table was incorporated into the spreadsheet. Formulae for standard calculations [sample size, disease prevalence, sensitivity and specificity with 95% confidence intervals, predictive values and likelihood ratios (LRs)] were linked to this table. The results change automatically when the data in the true or false negative and positive cells are changed. Section B: this estimates predictive values in any population, compensating for altered disease prevalence. Sections C-F: Bayes' theorem was incorporated to generate individual post-test probabilities. The spreadsheet generates 95% confidence intervals, LRs and a table and graph of conditional probabilities once the sensitivity and specificity of the test are entered. The latter shows the expected post-test probability of disease for any pre-test probability when a test of known sensitivity and specificity is positive or negative. This spreadsheet can be used on desktop and palmtop computers. The MS Excel(TM)version can be downloaded via the Internet from the URL ftp://radiography.com/pub/Rad-data99.xls A spreadsheet is useful for contingency table data analysis and assessment of the clinical meaning of diagnostic test results. Copyright 2000 The Royal College of Radiologists.

Flooding in the southern Midwestern United States, April–May 2017

USGS Publications Warehouse

Heimann, David C.; Holmes, Robert R.; Harris, Thomas E.

2018-03-09

Excessive rainfall resulted in flooding on numerous rivers throughout the southern Midwestern United States (southern Midwest) in late April and early May of 2017. The heaviest rainfall, between April 28 and 30, resulted in extensive flooding from eastern Oklahoma to southern Indiana including parts of Missouri, Arkansas, and Illinois.Peak-of-record streamflows were set at 21 U.S. Geological Survey (USGS) streamgages in the southern Midwest during the resulting April–May 2017 flooding and each of the five States included in the study area had at least one streamgage with a peak of record during the flood. The annual exceedance probability (AEP) estimates for the April–May 2017 peak streamflows indicate that peaks at 5 USGS streamgages had AEPs of 0.2 percent or less (500-year recurrence interval or greater), and peak streamflows at 15 USGS streamgages had AEPs in the range from greater than 0.2 to 1 percent (500- to 100-year recurrence intervals).Examination of the magnitude of the temporal changes in median annual peak streamflows indicated positive increases, in general, throughout the study area for each of the 1930–2017, 1956–2017, 1975–2017, and 1989–2017 analysis periods. The median increase in peak streamflows was greatest in 1975–2017 and 1989–2017 with maximum increases of 8 to 10 percent per year. No stations in the 1975–2017 or 1989–2017 analysis period had median negative changes in peak streamflows.

Challenges in Evaluating Relationships Between Quantitative Data (Carbon Dioxide) and Qualitative Data (Self-Reported Visual Changes)

NASA Technical Reports Server (NTRS)

Mendez, C. M.; Foy, M.; Mason, S.; Wear, M. L.; Meyers, V.; Law, J.; Alexander, D.; Van Baalen, M.

2014-01-01

Understanding the nuances in clinical data is critical in developing a successful data analysis plan. Carbon dioxide (CO2) data are collected on board the International Space Station (ISS) in a continuous stream. Clinical data on ISS are primarily collected via conversations between individual crewmembers and NASA Flight Surgeons during weekly Private Medical Conferences (PMC). Law, et.al, 20141 demonstrated a statistically significant association between weekly average CO2 levels on ISS and self-reported headaches over the reporting period from March 14, 2001 to May 31, 2012. The purpose of this analysis is to describe the evaluation of a possible association between visual changes and CO2 levels on ISS and to discuss challenges in developing an appropriate analysis plan. METHODS & PRELIMINARY RESULTS: A first analysis was conducted following the same study design as the published work on CO2 and self-reported headaches1; substituting self-reported changes in visual acuity in place of self-reported headaches. The analysis demonstrated no statistically significant association between visual impairment characterized by vision symptoms self-reported during PMCs and ISS average CO2 levels over ISS missions. Closer review of the PMC records showed that vision outcomes are not well-documented in terms of clinical severity, timing of onset, or timing of resolution, perhaps due to the incipient nature of vision changes. Vision has been monitored in ISS crewmembers, pre- and post-flight, using standard optometry evaluations. In-flight visual assessments were limited early in the ISS program, primarily consisting of self-perceived changes reported by crewmembers. Recently, on-orbit capabilities have greatly improved. Vision data ranges from self-reported post-flight changes in visual acuity, pre- to postflight changes identified during fundoscopic examination, and in-flight progression measured by advanced on-orbit clinical imaging capabilities at predetermined testing intervals. In contrast, CO2 data are recorded in a continuous stream over time; however, for the initial analysis this data was categorized into weekly averages.

The observation of the physicochemical change of rock under freeze-thawing experiment: CLSM, XRD and ICP analysis

NASA Astrophysics Data System (ADS)

Choi, J.; Chae, B.; Chon, C.; Jeong, J.

2013-12-01

Abstract : In order to understand the progress of the physical weathering of rock sample, we managed freeze-thawing experiment at temperature of up to 40C from -20C taking into account of South Korea. In this study, the time was held by two hours the temperature of the maximum (40C) and minimum (-20C) and the experiments were carried out at intervals of one hour rising and falling. We have run the experiment about 120 cycle with the cycle of -20C from 40C experiment. We measured the physical properties of rock samples after each 20 cycle has elapsed by using confocal laser scanning microscope (CLSM) and observed changes in roughness of rock samples surface. We also analyzed the mineral of rock sample using the XRD analysis and observing the change in chemical composition of solution used in the experiment by using ICP analysis. Through the above process, we observed physico-chemical changes in the rock sample due to freeze-thaw cycles. To analysis of the line roughness parameter we used set by the 10 vertical and horizontal cross section line on the surface and surface roughness parameter was analyzed by using the area on the surface. Through such a process, while the freeze-thawing experiment is advanced, it was studied how the physical roughness and chemical composition were changed. As a result, it was possible to observe a change in the mineral component of the particular dissolved in the solution and it was able to observe the characteristic changes of the parameters of the roughness of the lines and surfaces.

Individual Responses to Completion of Short-Term and Chronic Interval Training: A Retrospective Study

PubMed Central

Astorino, Todd A.; Schubert, Matthew M.

2014-01-01

Alterations in maximal oxygen uptake (VO2max), heart rate (HR), and fat oxidation occur in response to chronic endurance training. However, many studies report frequent incidence of “non-responders” who do not adapt to continuous moderate exercise. Whether this is the case in response to high intensity interval training (HIT), which elicits similar adaptations as endurance training, is unknown. The aim of this retrospective study was to examine individual responses to two paradigms of interval training. In the first study (study 1), twenty active men and women (age and baseline VO2max = 24.0±4.6 yr and 42.8±4.8 mL/kg/min) performed 6 d of sprint interval training (SIT) consisting of 4–6 Wingate tests per day, while in a separate study (study 2), 20 sedentary women (age and baseline VO2max = 23.7±6.2 yr and 30.0±4.9 mL/kg/min) performed 12 wk of high-volume HIT at workloads ranging from 60–90% maximal workload. Individual changes in VO2max, HR, and fat oxidation were examined in each study, and multiple regression analysis was used to identify predictors of training adaptations to SIT and HIT. Data showed high frequency of increased VO2max (95%) and attenuated exercise HR (85%) in response to HIT, and low frequency of response for VO2max (65%) and exercise HR (55%) via SIT. Frequency of improved fat oxidation was similar (60–65%) across regimens. Only one participant across both interventions showed non-response for all variables. Baseline values of VO2max, exercise HR, respiratory exchange ratio, and body fat were significant predictors of adaptations to interval training. Frequency of positive responses to interval training seems to be greater in response to prolonged, higher volume interval training compared to similar durations of endurance training. PMID:24847797

Interrupted time-series analysis yielded an effect estimate concordant with the cluster-randomized controlled trial result.

PubMed

Fretheim, Atle; Soumerai, Stephen B; Zhang, Fang; Oxman, Andrew D; Ross-Degnan, Dennis

2013-08-01

We reanalyzed the data from a cluster-randomized controlled trial (C-RCT) of a quality improvement intervention for prescribing antihypertensive medication. Our objective was to estimate the effectiveness of the intervention using both interrupted time-series (ITS) and RCT methods, and to compare the findings. We first conducted an ITS analysis using data only from the intervention arm of the trial because our main objective was to compare the findings from an ITS analysis with the findings from the C-RCT. We used segmented regression methods to estimate changes in level or slope coincident with the intervention, controlling for baseline trend. We analyzed the C-RCT data using generalized estimating equations. Last, we estimated the intervention effect by including data from both study groups and by conducting a controlled ITS analysis of the difference between the slope and level changes in the intervention and control groups. The estimates of absolute change resulting from the intervention were ITS analysis, 11.5% (95% confidence interval [CI]: 9.5, 13.5); C-RCT, 9.0% (95% CI: 4.9, 13.1); and the controlled ITS analysis, 14.0% (95% CI: 8.6, 19.4). ITS analysis can provide an effect estimate that is concordant with the results of a cluster-randomized trial. A broader range of comparisons from other RCTs would help to determine whether these are generalizable results. Copyright © 2013 Elsevier Inc. All rights reserved.

Publication Bias in Meta-Analysis: Confidence Intervals for Rosenthal's Fail-Safe Number.

PubMed

Fragkos, Konstantinos C; Tsagris, Michail; Frangos, Christos C

2014-01-01

The purpose of the present paper is to assess the efficacy of confidence intervals for Rosenthal's fail-safe number. Although Rosenthal's estimator is highly used by researchers, its statistical properties are largely unexplored. First of all, we developed statistical theory which allowed us to produce confidence intervals for Rosenthal's fail-safe number. This was produced by discerning whether the number of studies analysed in a meta-analysis is fixed or random. Each case produces different variance estimators. For a given number of studies and a given distribution, we provided five variance estimators. Confidence intervals are examined with a normal approximation and a nonparametric bootstrap. The accuracy of the different confidence interval estimates was then tested by methods of simulation under different distributional assumptions. The half normal distribution variance estimator has the best probability coverage. Finally, we provide a table of lower confidence intervals for Rosenthal's estimator.

Publication Bias in Meta-Analysis: Confidence Intervals for Rosenthal's Fail-Safe Number

PubMed Central

Fragkos, Konstantinos C.; Tsagris, Michail; Frangos, Christos C.

2014-01-01

The purpose of the present paper is to assess the efficacy of confidence intervals for Rosenthal's fail-safe number. Although Rosenthal's estimator is highly used by researchers, its statistical properties are largely unexplored. First of all, we developed statistical theory which allowed us to produce confidence intervals for Rosenthal's fail-safe number. This was produced by discerning whether the number of studies analysed in a meta-analysis is fixed or random. Each case produces different variance estimators. For a given number of studies and a given distribution, we provided five variance estimators. Confidence intervals are examined with a normal approximation and a nonparametric bootstrap. The accuracy of the different confidence interval estimates was then tested by methods of simulation under different distributional assumptions. The half normal distribution variance estimator has the best probability coverage. Finally, we provide a table of lower confidence intervals for Rosenthal's estimator. PMID:27437470

A dynamic model for plant growth: validation study under changing temperatures

NASA Technical Reports Server (NTRS)

Wann, M.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

1984-01-01

A dynamic simulation model to describe vegetative growth of plants, for which some functions and parameter values have been estimated previously by optimization search techniques and numerical experimentation based on data from constant temperature experiments, is validated under conditions of changing temperatures. To test the predictive capacity of the model, dry matter accumulation in the leaves, stems, and roots of tobacco plants (Nicotiana tabacum L.) was measured at 2- or 3-day intervals during a 5-week period when temperatures in controlled-environment rooms were programmed for changes at weekly and daily intervals and in ascending or descending sequences within a range of 14 to 34 degrees C. Simulations of dry matter accumulation and distribution were carried out using the programmed changes for experimental temperatures and compared with the measured values. The agreement between measured and predicted values was close and indicates that the temperature-dependent functional forms derived from constant-temperature experiments are adequate for modelling plant growth responses to conditions of changing temperatures with switching intervals as short as 1 day.

Thermal sensation, rate of temperature change, and the heat dissipation design for tablet computers.

PubMed

Zhang, Han; Hedge, Alan; Cosley, Daniel

2017-07-01

Past research has shown that the rate of change of skin surface temperature can affect thermal sensation. This study investigated users' thermal responses to a tablet heating surface with different heat pads and different temperature change rates. The test conditions included: A. keeping the surface at a constant 42 °C, B. increasing the surface temperature from 38 °C to 42 °C at a rate of 0.02 °C/s in progressive intervals, C. increasing the temperature at 0.15 °C/s in progressive intervals, and D. Heating two left and right side pads alternately from 38 °C to 42 °C at 0.15 °C/s in progressive intervals. Overall results showed the lowest temperature change rate of 0.02 °C/s was most preferred in terms of thermal comfort. The findings suggest a potential to improve user thermal experience by dissipating tablet computer heat at a lower temperature change rate, or by alternating the dissipation areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Late Holocene influence of societies on the fire regime in southern Québec temperate forests

NASA Astrophysics Data System (ADS)

Blarquez, Olivier; Talbot, Julie; Paillard, Jordan; Lapointe-Elmrabti, Lyna; Pelletier, Nicolas; Gates St-Pierre, Christian

2018-01-01

Climatic change that occurred during the Holocene is often recognized as the main factor for explaining fire dynamics, while the influence of human societies is less apparent. In eastern North America, human influence on fire regime before European settlement has been debated, mainly because of a paucity of sites and paleoecological techniques that can distinguish human influences unequivocally from climate. We applied a multiproxy analysis to a 12 000-year-old paleoecological sequence from a site in the vicinity of known settlement areas that were occupied over more than 7000 years. From this analysis, we were able detect the human influence on the fire regime before and after European colonization. Fire occurrence and fire return intervals (FRI) were based on analysis of sedimentary charcoals at a high temporal and spatial resolution. Fire occurrence was then compared to vegetation that was reconstructed from pollen analysis, from population densities deduced from archeological site dating, from demographic and technological models, and from climate reconstructed using general circulation models and ice-core isotopes. Holocene mean FRI was short (164 ± 134 years) and associated with small charcoal peaks that were likely indicative of surface fires affecting small areas. After 1500 BP, large vegetation changes and human demographic growth that was demonstrated through increased settlement evidence likely caused the observed FRI lengthening (301 ± 201 years), which occurred without significant changes in climate. Permanent settlement by Europeans in the area around 1800 AD was followed by a substantial demographic increase, leading to the establishment of Gatineau, Hull and Ottawa. This trend was accompanied by a shift in the charcoal record toward anthropogenic particles that were reflective of fossil fuel burning and an apparent absence of wood charcoal that would be indicative of complete fire suppression. An anthropogenic fire regime that was characterized by severe and large fires and long fire-return intervals occurred more than 1000 years ago, concomitant with the spread of native agriculture, which intensified with European colonization over the past two centuries.

Is it necessary to perform prophylactic cholecystectomy for asymptomatic subjects with gallbladder polyps and gallstones?

PubMed

Choi, Sung Youn; Kim, Tae Sun; Kim, Hong Joo; Park, Jung Ho; Park, Dong Il; Cho, Yong Kyun; Sohn, Chong Il; Jeon, Woo Kyu; Kim, Byung Ik

2010-06-01

The purpose of the present study was to determine the clinical characteristics of subjects with gallbladder polyps and cholelithiasis compared with those with gallbladder polyps only. Between August 1999 and December 2005, 176 subjects with gallbladder polyps and cholelithiasis (study group) by transabdominal ultrasonography performed during a medical check-up at our institution were recruited and compared with a control group of 185 subjects who had gallbladder polyps only. No significant difference in the mean interval change (delta) of polyp size during the follow-up period between the study and control groups (0.85 +/- 1.39 mm vs 0.84 +/- 1.58 mm, respectively, P = 0.927) was noted. A significantly higher proportion (9/176 [5.1%]) of examinees in the study group had attacks of acute cholecystitis compared with the control group (1/185 [0.5%], P < 0.01). By multivariate logistic regression analysis, gallbladder wall thickening on initial ultrasonography (odds ratio, 13.7; 95% confidence interval, 1.1-178.0; P = 0.046) and the interval increase in the size of the gallbladder polyps (odds ratio, 14.7; 95% confidence interval, 1.7-126.9; P = 0.014) were independent risk factors for cholecystectomy. No gallbladder cancer occurred during the follow-up period. There was no significant difference in delta polyp size between the examinees with gallbladder polyps and cholelithiasis and those with gallbladder polyps only. Hence, a small proportion of subjects with gallbladder polyps and cholelithiasis, such as those with thickened gallbladder walls and an interval increase in the size of the gallbladder polyps are candidates for prophylactic cholecytectomy.

Trends of preterm birth and low birth weight in Japan: a one hospital-based study.

PubMed

Yorifuji, Takashi; Naruse, Hiroo; Kashima, Saori; Murakoshi, Takeshi; Kato, Tsuguhiko; Inoue, Sachiko; Doi, Hiroyuki; Kawachi, Ichiro

2012-12-26

The proportions of preterm birth (PTB, ie., delivered before 37 gestational weeks) and low birth weight (LBW, ie., birth weight less than 2500 g at delivery) have been rising in developed countries. We sought to examine the factors contributing to the rise in Japan, with particular focus on the effects of obstetric interventions. We used a database maintained by one large regional hospital in Shizuoka, Japan. We restricted the analysis to mothers who delivered live singleton births from 1997 to 2010 (n = 19,221). We assessed the temporal trends in PTB and LBW, then divided the study period into four intervals and compared the proportions of PTB and LBW. We also compared the newborns' outcomes between the intervals. PTB, in particular medically indicated PTB, increased considerably. The increase was largely explained by changes in caesarean sections. The neonatal outcomes did not worsen, and instead the Apgar scores and proportions requiring neonatal intensive care unit (NICU) admission improved. In particular, the risks of NICU admission in the interval from 2007 to 2010 were decreased among all births [odds ratio (OR): 0.84; 95% confidence interval (CI): 0.75, 0.95] and medically indicated births (OR: 0.44; 95% CI: 0.29, 0.68) compared with the interval from 1997 to 2000. Despite the increases in PTB as well as LBW, the present study suggests benefits of obstetric interventions. Rather than simple categorization of PTB or LBW, indicators such as perinatal mortality or other outcomes may be more appropriate for evaluation of perinatal health in developed countries.

Time-variant random interval natural frequency analysis of structures

NASA Astrophysics Data System (ADS)

Wu, Binhua; Wu, Di; Gao, Wei; Song, Chongmin

2018-02-01

This paper presents a new robust method namely, unified interval Chebyshev-based random perturbation method, to tackle hybrid random interval structural natural frequency problem. In the proposed approach, random perturbation method is implemented to furnish the statistical features (i.e., mean and standard deviation) and Chebyshev surrogate model strategy is incorporated to formulate the statistical information of natural frequency with regards to the interval inputs. The comprehensive analysis framework combines the superiority of both methods in a way that computational cost is dramatically reduced. This presented method is thus capable of investigating the day-to-day based time-variant natural frequency of structures accurately and efficiently under concrete intrinsic creep effect with probabilistic and interval uncertain variables. The extreme bounds of the mean and standard deviation of natural frequency are captured through the embedded optimization strategy within the analysis procedure. Three particularly motivated numerical examples with progressive relationship in perspective of both structure type and uncertainty variables are demonstrated to justify the computational applicability, accuracy and efficiency of the proposed method.

Should Levetiracetam or Phenytoin Be Used for Posttraumatic Seizure Prophylaxis? A Systematic Review of the Literature and Meta-analysis.

PubMed

Khan, Nickalus R; VanLandingham, Matthew A; Fierst, Tamara M; Hymel, Caroline; Hoes, Kathryn; Evans, Linton T; Mayer, Rory; Barker, Fred; Klimo, Paul

2016-12-01

Posttraumatic seizure (PTS) is a significant complication of traumatic brain injury (TBI). To perform a systematic review and meta-analysis to compare levetiracetam with phenytoin for seizure prophylaxis in patients diagnosed with severe TBI. An inclusive search of several electronic databases and bibliographies was conducted to identify scientific studies that compared the effect of levetiracetam and phenytoin on PTS. Independent reviewers obtained data and classified the quality of each article that met inclusion criteria. A random effects meta-analysis was then completed. During June and July 2015, a systematic literature search was performed that identified 6097 articles. Of these, 7 met inclusion criteria. A random-effects meta-analysis was performed. A total of 1186 patients were included. The rate of seizure was 35 of 654 (5.4%) in the levetiracetam cohort and 18 of 532 (3.4%) in the phenytoin cohort. Our meta-analysis revealed no change in the rate of early PTS with levetiracetam compared with phenytoin (relative risk, 1.02; 95% confidence interval, 0.53-1.95; P = .96). The lack of evidence on which antiepileptic drug to use in PTS is surprising given the number of patients prescribed an antiepileptic drug therapy for TBI. On the basis of currently available Level III evidence, patients treated with either levetiracetam or phenytoin have similar incidences of early seizures after TBI. ADE, adverse drug eventAED, antiepileptic drugCI, confidence intervalOR, odds ratioPTS, posttraumatic seizureTBI, traumatic brain injury.

Autonomic nervous functions in fetal type Minamata disease patients: assessment of heart rate variability.

PubMed

Oka, Tomoko; Matsukura, Makoto; Okamoto, Miwako; Harada, Noriaki; Kitano, Takao; Miike, Teruhisa; Futatsuka, Makoto

2002-12-01

In order to assess the cardiovascular autonomic nervous functions in patients with fetal type Minamata disease (FMD), we investigated blood pressure (BP), and conducted time and frequency domain analysis of heart rate variability (HRV). Subjects were 9 patients in Meisuien recognized as FMD, and 13 healthy age matched control subjects. HRV and BP were assessed after subjects rested in a supine position for 10 minutes. Electrocardiographic (ECG) data were collected for 3 minutes during natural breathing. Time domain analysis (the average of R-R intervals [Mean RR], standard deviation of R-R intervals [SD RR], coefficient of variation [CV]), and frequency domain analysis by fast Fourier transformation (FFT) (power of low frequency [LF] and high frequency [HF] component, expressed in normalized units[nu]) were then conducted. In the time domain analysis, the mean RR of the FMD group was significantly lower than that of the control group. Neither SD RR nor CV showed significant differences between the two groups, but both tended to be lower in the FMD group. In the frequency domain analysis, the HF component of the FMD group was significantly lower than that of the control group. Pulse pressure (PP) was significantly lower in the FMD subjects. These findings suggest that parasympathetic nervous dysfunction might exist in FMD patients, who were exposed to high doses of methylmercury (MeHg) during the prenatal period. Decrease of PP might be due to degenerative changes of blood vessels driven by exposure to high doses of MeHg.

Evaluation of Direct and Indirect Methods of Sub-Neoglottic Pressure Measurement in Tracheoesophageal Speakers: A Systematic Review and Meta-Analysis.

PubMed

Sheela, Shekaraiah; Aithal, Venkataraja U; Rajashekhar, Bellur; Lewis, Melissa Glenda

2016-01-01

Tracheoesophageal (TE) prosthetic voice is one of the voice restoration options for individuals who have undergone a total laryngectomy. Aerodynamic analysis of the TE voice provides insight into the physiological changes that occur at the level of the neoglottis with voice prosthesis in situ. The present study is a systematic review and meta-analysis of sub-neoglottic pressure (SNP) measurement in TE speakers by direct and indirect methods. The screening of abstracts and titles was carried out for inclusion of articles using 10 electronic databases spanning the period from 1979 to 2016. Ten articles which met the inclusion criteria were considered for meta-analysis with a pooled age range of 40-83 years. The pooled mean SNP obtained from the direct measurement method was 53.80 cm H2O with a 95% confidence interval of 21.14-86.46 cm H2O, while for the indirect measurement method, the mean SNP was 23.55 cm H2O with a 95% confidence interval of 19.23-27.87 cm H2O. Based on the literature review, the various procedures followed for direct and indirect measurements of SNP contributed to a range of differences in outcome measures. The meta-analysis revealed that the "interpolation method" for indirect estimation of SNP was the most acceptable and valid method in TE speakers. © 2017 S. Karger AG, Basel.

Refractory urgency urinary incontinence treatment in women: impact of age on outcomes and complications.

PubMed

Komesu, Yuko M; Amundsen, Cindy L; Richter, Holly E; Erickson, Stephen W; Ackenbom, Mary F; Andy, Uduak U; Sung, Vivian W; Albo, Michael; Gregory, W Thomas; Paraiso, Marie Fidela; Wallace, Dennis

2018-01-01

Women with refractory urgency urinary incontinence (ie, unresponsive to behavioral and pharmacological interventions) are treated with onabotulinumtoxinA or sacral neuromodulation. The objective of the study was to compare treatment efficacy and adverse events in women <65 and ≥65 years old treated with onabotulinumtoxinA or sacral neuromodulation. This study was a planned secondary analysis of a multicenter, randomized trial that enrolled community-dwelling women with refractory urgency urinary incontinence to onabotulinumtoxinA or sacral neuromodulation treatments. The primary outcome was a change in mean daily urgency urinary incontinence episodes on a bladder diary over 6 months. Secondary outcomes included ≥75% urgency urinary incontinence episode reduction, change in symptom severity/quality of life, treatment satisfaction, and treatment-related adverse events. Both age groups experienced improvement in mean urgency urinary incontinence episodes per day following each treatment. There was no evidence that mean daily urgency urinary incontinence episode reduction differed between age groups for onabotulinumtoxinA (adjusted coefficient, -0.127, 95% confidence interval, -1.233 to 0.979; P = .821) or sacral neuromodulation (adjusted coefficient, -0.698, 95% confidence interval, -1.832 to 0.437; P = .227). Among those treated with onabotulinumtoxinA, women <65 years had 3.3-fold greater odds of ≥75% resolution than women ≥65 years (95% confidence interval, 1.56 -7.02). Women <65 years had a greater reduction in Overactive Bladder Questionnaire Short Form symptom bother scores compared with women ≥65 years by 7.49 points (95% confidence interval, -3.23 to -11.74), regardless of treatment group. There was no difference between quality of life improvement by age. Women ≥65 years had more urinary tract infections following onabotulinumtoxinA and sacral neuromodulation (odds ratio, 1.9, 95% confidence interval, 1.2-3.3). There was no evidence of age differences in sacral neuromodulation revision/removal or catheterization following onabotulinumtoxinA treatment. Younger women experienced greater absolute continence, symptom improvement, and fewer urinary tract infections; both older and younger women had beneficial urgency urinary incontinence episode reduction, similar rates of other treatment adverse events, and improved quality of life. Copyright © 2017 Elsevier Inc. All rights reserved.

Timing and effect of a safe routes to school program on child pedestrian injury risk during school travel hours: Bayesian changepoint and difference-in-differences analysis.

PubMed

DiMaggio, Charles; Chen, Qixuan; Muennig, Peter A; Li, Guohua

2014-12-01

In 2005, the US Congress allocated $612 million for a national Safe Routes to School (SRTS) program to encourage walking and bicycling to schools. We evaluated the effectiveness of a SRTS in controlling pedestrian injuries among school-age children. Bayesian changepoint analysis was applied to model the quarterly counts of pedestrian injuries among 5- to 19-year old children in New York City between 2001 and 2010 during school-travel hours in census tracts with and without SRTS. Overdispersed Poisson model was used to estimate difference-in-differences in injury risk between census tracts with and without SRTS following the changepoint. In SRTS-intervention census tracts, a change point in the quarterly counts of injuries was identified in the second quarter of 2008, which was consistent with the timing of the implementation of SRTS interventions. In census tracts with SRTS interventions, the estimated quarterly rates of pedestrian injury per 10,000 population among school-age children during school-travel hours were 3.47 (95% Credible Interval [CrI] 2.67, 4.39) prior to the changepoint, and 0.74 (95% CrI 0.30, 1.50) after the changepoint. There was no change in the average number of quarterly injuries in non-SRTS census tracts. Overdispersed Poisson modeling revealed that SRTS implementation was associated with a 44% reduction (95% Confidence Interval [CI] 87% decrease to 130% increase) in school-age pedestrian injury risk during school-travel hours. Bayesian changepoint analysis of quarterly counts of school-age pedestrian injuries successfully identified the timing of SRTS intervention in New York City. Implementation of the SRTS program in New York City appears to be effective in reducing school-age pedestrian injuries during school-travel hours.

High intensity interval training in the heat enhances exercise-induced lipid peroxidation, but prevents protein oxidation in physically active men

PubMed Central

Souza-Silva, Ana Angélica; Moreira, Eduardo; de Melo-Marins, Denise; Schöler, Cinthia M.; de Bittencourt, Paulo Ivo Homem; Laitano, Orlando

2016-01-01

ABSTRACT Aim. The purpose of this study was to determine the response of circulating markers of lipid and protein oxidation following an incremental test to exhaustion before and after 4 weeks of high-intensity interval training performed in the heat. Methods. To address this question, 16 physically active men (age = 23 ± 2 years; body mass = 73 ± 12 kg; height = 173 ± 6 cm; % body fat = 12.5 ± 6 %; body mass index = 24 ± 4 kg/m2) were allocated into 2 groups: control group (n = 8) performing high-intensity interval training at 22°C, 55% relative humidity and heat group (n = 8) training under 35°C, 55% relative humidity. Both groups performed high-intensity interval training 3 times per week for 4 consecutive weeks, accumulating a total of 12 training sessions. Before and after the completion of 4 weeks of high-intensity interval training, participants performed an incremental cycling test until exhaustion under temperate environment (22°C, 55% relative humidity) where blood samples were collected after the test for determination of exercise-induced changes in oxidative damage biomarkers (thiobarbituric acid reactive species and protein carbonyls). Results. When high-intensity interval training was performed under control conditions, there was an increase in protein carbonyls (p < 0.05) following the incremental test to exhaustion with no changes in thiobarbituric acid reactive species. Conversely, high-intensity interval training performed in high environmental temperature enhanced the incremental exercise-induced increases in thiobarbituric acid reactive species (p < 0.05) with no changes in protein carbonyls. Conclusion. In conclusion, 4 weeks of high-intensity interval training performed in the heat enhances exercise-induced lipid peroxidation, but prevents protein oxidation following a maximal incremental exercise in healthy active men. PMID:27227083

Metabolic and hormonal responses to isoenergetic high-intensity interval exercise and continuous moderate-intensity exercise.

PubMed

Peake, Jonathan M; Tan, Sok Joo; Markworth, James F; Broadbent, James A; Skinner, Tina L; Cameron-Smith, David

2014-10-01

This study investigated the effects of high-intensity interval training (HIIT) vs. work-matched moderate-intensity continuous exercise (MOD) on metabolism and counterregulatory stress hormones. In a randomized and counterbalanced order, 10 well-trained male cyclists and triathletes completed a HIIT session [81.6 ± 3.7% maximum oxygen consumption (V̇o2 max); 72.0 ± 3.2% peak power output; 792 ± 95 kJ] and a MOD session (66.7 ± 3.5% V̇o2 max; 48.5 ± 3.1% peak power output; 797 ± 95 kJ). Blood samples were collected before, immediately after, and 1 and 2 h postexercise. Carbohydrate oxidation was higher (P = 0.037; 20%), whereas fat oxidation was lower (P = 0.037; -47%) during HIIT vs. MOD. Immediately after exercise, plasma glucose (P = 0.024; 20%) and lactate (P < 0.01; 5.4×) were higher in HIIT vs. MOD, whereas total serum free fatty acid concentration was not significantly different (P = 0.33). Targeted gas chromatography-mass spectromtery metabolomics analysis identified and quantified 49 metabolites in plasma, among which 11 changed after both HIIT and MOD, 13 changed only after HIIT, and 5 changed only after MOD. Notable changes included substantial increases in tricarboxylic acid intermediates and monounsaturated fatty acids after HIIT and marked decreases in amino acids during recovery from both trials. Plasma adrenocorticotrophic hormone (P = 0.019), cortisol (P < 0.01), and growth hormone (P < 0.01) were all higher immediately after HIIT. Plasma norepinephrine (P = 0.11) and interleukin-6 (P = 0.20) immediately after exercise were not significantly different between trials. Plasma insulin decreased during recovery from both HIIT and MOD (P < 0.01). These data indicate distinct differences in specific metabolites and counterregulatory hormones following HIIT vs. MOD and highlight the value of targeted metabolomic analysis to provide more detailed insights into the metabolic demands of exercise. Copyright © 2014 the American Physiological Society.

Clinical Outcomes of Comparing Soft Tissue Alternatives to Free Gingival Graft: A Systematic Review and Meta-Analysis
.

PubMed

Dragan, Irina F; Hotlzman, Lucrezia Paterno; Karimbux, Nadeem Y; Morin, Rebecca A; Bassir, Seyed Hossein

2017-12-01

This systematic review and meta-analysis aimed to compare clinical outcomes and width of keratinized tissue (KT) around teeth, following the soft tissue alter- natives and free gingival graft (FGG) procedures. The specific graft materials that were explored were extracellular matrix membrane, bilayer collagen membrane, living cellular construct, and acellular dermal matrix. Four different databases were queried to identify human controlled clinical trials and randomized controlled clinical trials that fulfilled the eligibility criteria. Relevant studies were identified by 3 independent reviewers, compiling the results of the electronic and handsearches. Studies identified through electronic and handsearches were reviewed by title, abstract, and full text using Covidence Software. Primary outcome in the present study was change in the width of KT. Results of the included studies were pooled to estimate the effect size, expressed as weighted mean differences and 95% confidence interval. A random-effects model was used to perform the meta-analyses. Six hundred thirty-eight articles were screened by title, 55 articles were screened by abstracts, and 34 full-text articles were reviewed. Data on quantitative changes in width of KT were provided in 7 studies. Quantitative analyses revealed a significant difference in changes in width of KT between patients treated with soft tissue alternatives and patients treated with FGGs (P < .001). The weighted mean difference of changes in the width of KT was 21.39 (95% confidence interval: 21.82 to 20.96; heterogeneity I 5 70.89%), indicating patients who were treated with soft tissue alternatives gained 1.39 mm less KT width compared with the patients who received free gingival graft. Based on the clinical outcomes, the results of this systematic review and meta-analysis showed that soft tissue alternatives result in an increased width of KT. Patients in the soft tissue alternatives group obtained 1.39 mm less KT compared with those in the FGGs group. Copyright © 2017 Elsevier Inc. All rights reserved.

Pediatric reference value distributions and covariate-stratified reference intervals for 29 endocrine and special chemistry biomarkers on the Beckman Coulter Immunoassay Systems: a CALIPER study of healthy community children.

PubMed

Karbasy, Kimiya; Lin, Danny C C; Stoianov, Alexandra; Chan, Man Khun; Bevilacqua, Victoria; Chen, Yunqi; Adeli, Khosrow

2016-04-01

The CALIPER program is a national research initiative aimed at closing the gaps in pediatric reference intervals. CALIPER previously reported reference intervals for endocrine and special chemistry markers on Abbott immunoassays. We now report new pediatric reference intervals for immunoassays on the Beckman Coulter Immunoassay Systems and assess platform-specific differences in reference values. A total of 711 healthy children and adolescents from birth to <19 years of age were recruited from the community. Serum samples were collected for measurement of 29 biomarkers on the Beckman Coulter Immunoassay Systems. Statistically relevant age and/or gender-based partitions were determined, outliers removed, and reference intervals calculated in accordance with Clinical and Laboratory Standards Institute (CLSI) EP28-A3c guidelines. Complex profiles were observed for all 29 analytes, necessitating unique age and/or sex-specific partitions. Overall, changes in analyte concentrations observed over the course of development were similar to trends previously reported, and are consistent with biochemical and physiological changes that occur during childhood. Marked differences were observed for some assays including progesterone, luteinizing hormone and follicle-stimulating hormone where reference intervals were higher than those reported on Abbott immunoassays and parathyroid hormone where intervals were lower. This study highlights the importance of determining reference intervals specific for each analytical platform. The CALIPER Pediatric Reference Interval database will enable accurate diagnosis and laboratory assessment of children monitored by Beckman Coulter Immunoassay Systems in health care institutions worldwide. These reference intervals must however be validated by individual labs for the local pediatric population as recommended by CLSI.

Daily thanatomicrobiome changes in soil as an approach of postmortem interval estimation: An ecological perspective.

PubMed

Adserias-Garriga, Joe; Hernández, Marta; Quijada, Narciso M; Rodríguez Lázaro, David; Steadman, Dawnie; Garcia-Gil, Jesús

2017-09-01

Understanding human decomposition is critical for its use in postmortem interval (PMI) estimation, having a significant impact on forensic investigations. In recognition of the need to establish the scientific basis for PMI estimation, several studies on decomposition have been carried out in the last years. The aims of the present study were: (i) to identify soil microbiota communities involved in human decomposition through high-throughput sequencing (HTS) of DNA sequences from the different bacteria, (ii) to monitor quantitatively and qualitatively the decay of such signature species, and (iii) to describe succesional changes in bacterial populations from the early putrefaction state until skeletonization. Three donated individuals to the University of Tennessee FAC were studied. Soil samples around the body were taken from the placement of the donor until advanced decay/dry remains stage. Bacterial DNA extracts were obtained from the samples, HTS techniques were applied and bioinformatic data analysis was performed. The three cadavers showed similar overall successional changes. At the beginning of the decomposition process the soil microbiome consisted of diverse indigenous soil bacterial communities. As decomposition advanced, Firmicutes community abundance increased in the soil during the bloat stage. The growth curve of Firmicutes from human remains can be used to estimate time since death during Tennessee summer conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Circulating protein synthesis rates reveal skeletal muscle proteome dynamics

PubMed Central

Shankaran, Mahalakshmi; King, Chelsea L.; Angel, Thomas E.; Holmes, William E.; Li, Kelvin W.; Colangelo, Marc; Price, John C.; Turner, Scott M.; Bell, Christopher; Hamilton, Karyn L.; Miller, Benjamin F.; Hellerstein, Marc K.

2015-01-01

Here, we have described and validated a strategy for monitoring skeletal muscle protein synthesis rates in rodents and humans over days or weeks from blood samples. We based this approach on label incorporation into proteins that are synthesized specifically in skeletal muscle and escape into the circulation. Heavy water labeling combined with sensitive tandem mass spectrometric analysis allowed integrated synthesis rates of proteins in muscle tissue across the proteome to be measured over several weeks. Fractional synthesis rate (FSR) of plasma creatine kinase M-type (CK-M) and carbonic anhydrase 3 (CA-3) in the blood, more than 90% of which is derived from skeletal muscle, correlated closely with FSR of CK-M, CA-3, and other proteins of various ontologies in skeletal muscle tissue in both rodents and humans. Protein synthesis rates across the muscle proteome generally changed in a coordinate manner in response to a sprint interval exercise training regimen in humans and to denervation or clenbuterol treatment in rodents. FSR of plasma CK-M and CA-3 revealed changes and interindividual differences in muscle tissue proteome dynamics. In human subjects, sprint interval training primarily stimulated synthesis of structural and glycolytic proteins. Together, our results indicate that this approach provides a virtual biopsy, sensitively revealing individualized changes in proteome-wide synthesis rates in skeletal muscle without a muscle biopsy. Accordingly, this approach has potential applications for the diagnosis, management, and treatment of muscle disorders. PMID:26657858

A Multi-spacecraft Study of the Magnetospheric Influence on Ionospheric Chemistry - a Detailed Examination of Recent Geomagnetically Active Periods

NASA Astrophysics Data System (ADS)

Petrinec, S. M.; Chenette, D. L.; Imhof, W. L.; Baker, D. N.; Barth, C. A.; Mankoff, K. D.; Luhmann, J. G.; Mason, G. M.; Mazur, J. E.; Evans, D. S.

2001-12-01

A detailed analysis of the particle precipitation into the auroral regions during specific storm intervals is performed. The global energetic particle input to the ionosphere and lower thermosphere is provided by several monitors; namely the Polar Ionospheric X-ray Experiment (PIXIE) on board the NASA/GGS Polar satellite (for inferred electron energies greater than about 3 keV); the TED sensor system on board the NOAA/Polar Orbiting Environmental Satellite (POES) (particle energies between about 50 eV and 20 keV), and the sensor system (LICA) on board the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) spacecraft (for electron energies greater then 25 keV). Changes in nitric oxide (NO) densities at altitudes between 97 and 150 km during these storm intervals are studied using observations from the Student Nitric Oxide Explorer (SNOE). Solar wind observations are also used to provide important information regarding the external drivers for the magnetospheric input to the upper atmosphere. Specific intervals of examination include the recent large geomagnetic event of March 31-April 1, 2001, and other events from the most recent solar maximum.

Early-middle Eocene transition in calcareous nannofossil assemblages at IODP Site U1410 (Southeast Newfoundland Ridge, NW Atlantic)

NASA Astrophysics Data System (ADS)

Cappelli, Carlotta; Agnini, Claudia; Yamamoto, Yuhji

2017-04-01

The early-middle Eocene interval documents the shift from the warmest greenhouse conditions occurred during the Early Eocene Climatic Optimum (EECO, 52-50 Ma) to the beginning of the cooling phase which led to the Oligocene icehouse regime. This important transition is well expressed as a reversal in the global oxygen and carbonate isotope trends (Zachos et al., 2001). Moreover, this interval was a time of remarkable transformation in the marine biosphere. Communities of calcareous nannoplankton, marine calcifying algae at the base of the oceans food chain, experienced transient and permanent profound changes. Calcareous nannofossil are regarded as remarkable tools both in biostratigraphy and paleoecology, with several taxa that show different responses to changes in physical parameters of surface waters. Here, we aim to document calcareous nannoplankton assemblage changes across the early-middle Eocene transition, in order to upset the biostratigraphic framework and to increase comprehension of how phytoplankton communities responded to paleoenvironmental changes at that time. The sedimentary successions recovered at IODP Site U1410 (Exp. 342; 41˚ 19.6987'N; 49˚ 10.1995'W, Norris et al., 2012) on the Southeast Newfoundland Ridge (NW Atlantic) offer an expanded record of the early-middle Eocene interval that is marked by an increase in accumulation rate related to sedimentation of clay-rich nannofossil oozes. Quantitative analysis of calcareous nannofossil assemblages was conducted, encompassing calcareous nannofossil Zones NP12 -NP15 or CNE4-CNE10 (Martini, 1971; Agnini et al., 2014). The study interval records the appearance and proliferation of Noelaerhabdaceae family (i.e, Reticulofenestra/Dictyococcites group), which can be considered one of the most significant shifts in the assemblage structure of the Paleogene. This change was probably favored by modifications in surface water chemistry. The middle Eocene clay-rich sediments contain well preserved nannofossils, making this Site suitable for a comprehensive taxonomic revision of Nannotetrina and Chiasmolithus. Biohorizons related to species belonging to these two genera are used to mark middle Eocene biozone boundary, a better characterization of their taxonomy would thus improve their reliability as biostratigraphic tools. Furthermore, during the early middle Eocene a new evolutionary lineage, which includes S. kempii - S. perpendicularis- S. furcatholitoides morph. A - S. cuniculus - S. furcatholitoides morph. B occurred among sphenoliths. This plexus is characterized by progressive morphological changes which, if correctly identify, will allow for a very detailed subdivision of this interval. Even more interestingly, we would assess if there is any relationship between this evolutionary trend and the surrounding abiotic conditions. Agnini, C., Fornaciari, E., Raffi, I., Catanzariti, R., Pälike, H., Backman, J., and Rio, D., Newslett. Stratigr., 47, 131-181 (2014). Martini E., in: Farinacci, A. (Ed.), Proceedings 2nd International Conference Planktonic Microfossils Roma: Rome (Ed. Tecnosci.) 2, 739-785 (1971). Norris R.D., Wilson P.A., Blum P. and the IODP Expedition 342 Scientists, Proceedings of the Integrated Ocean Drilling Program, 342, 1-148 (2012). Zachos J., Pagani M., Sloan L., Thomas E., Billups K., Science, 292, 686-693 (2001).

Atmospheric Carbon Dioxide and its Relation to Carbon Cycle Perturbations During Ocean Anoxic Event 1d: A High Resolution Record From Dispersed Plant Cuticle

NASA Astrophysics Data System (ADS)

Richey, J. D.; Upchurch, G. R.; Joeckel, R.; Smith, J. J.; Ludvigson, G. A.; Lomax, B. H.

2013-12-01

Past geological greenhouse intervals are associated with Ocean Anoxic Events (OAEs), which result from an increase in marine primary productivity and/or an increase in the preservation of organic matter. The end point is widespread black shale deposition combined with a long-term atmospheric positive δ13C excursion and an increase in the burial of 12C. Some OAEs show a negative δ13C excursion preceding the positive excursion, indicating a perturbation in the global carbon cycle prior to the initiation of these events. The Rose Creek (RCP) locality, southeastern Nebraska, is the only known terrestrial section that preserves OAE1d (Cretaceous, Albian-Cenomanian Boundary) and has abundant charcoal and plant cuticle. These features allow for a combined carbon isotope and stomatal index (SI) analysis to determine both changes in the cycling between carbon pools (C isotope analysis) and changes in paleo-CO2 via changes in SI. Preliminary (and ongoing) SI data analysis using dispersed cuticle of Pandemophyllum kvacekii (an extinct Laurel) collected at 30 cm intervals indicate changes in SI consistent with changes in CO2. Fitting our samples to a published RCP δ13C profile, pre-excursion CO2 concentrations are high. CO2 decreases to lower concentrations in the basal 1.2 m of the RCP section, where δ13Cbulk shows a negative excursion and δ13Ccharcoal remains at pre-excursion values. CO2 concentrations become higher toward the top of the negative δ13C excursion, where δ13Cbulk and δ13Ccharcoal are at their most negative values, and drop as the negative carbon excursion terminates. Using published transfer functions, we estimate that pre-excursion CO2 concentrations were a maximum of 900 ppm. In the basal 1.2 m of RCP, CO2 drops to a maximum of 480 ppm, and rises to a maximum of 710 ppm near the top of the negative excursion. As δ13C values rise towards pre-excursion values, CO2 declines to a maximum of 400 ppm. The trend in SI is comparable to the trend in δ13Ccharcoal and follows recognized patterns, while SI shows partial divergence from δ13Cbulk. These data, while preliminary, highlight the importance of considering isotope substrate when investigating carbon cycle perturbations.

A Single Bout of High-Intensity Interval Training Improves Motor Skill Retention in Individuals With Stroke.

PubMed

Nepveu, Jean-Francois; Thiel, Alexander; Tang, Ada; Fung, Joyce; Lundbye-Jensen, Jesper; Boyd, Lara A; Roig, Marc

2017-08-01

One bout of high-intensity cardiovascular exercise performed immediately after practicing a motor skill promotes changes in the neuroplasticity of the motor cortex and facilitates motor learning in nondisabled individuals. To determine if a bout of exercise performed at high intensity is sufficient to induce neuroplastic changes and improve motor skill retention in patients with chronic stroke. Twenty-two patients with different levels of motor impairment were recruited. On the first session, the effects of a maximal graded exercise test on corticospinal and intracortical excitability were assessed from the affected and unaffected primary motor cortex representational area of a hand muscle with transcranial magnetic stimulation. On the second session, participants were randomly assigned to an exercise or a nonexercise control group. Immediately after practicing a motor task, the exercise group performed 15 minutes of high-intensity interval training while the control group rested. Twenty-four hours after motor practice all participants completed a test of the motor task to assess skill retention. The graded exercise test reduced interhemispheric imbalances in GABA A -mediated short-interval intracortical inhibition but changes in other markers of excitability were not statistically significant. The group that performed high-intensity interval training showed a better retention of the motor skill. The performance of a maximal graded exercise test triggers only modest neuroplastic changes in patients with chronic stroke. However, a single bout of high-intensity interval training performed immediately after motor practice improves skill retention, which could potentially accelerate motor recovery in these individuals.

Diseases, reproductive performance, and changes in milk production associated with subclinical ketosis in dairy cows: a meta-analysis and review.

PubMed

Raboisson, D; Mounié, M; Maigné, E

2014-12-01

Many studies have shown that subclinical ketosis (SCK) is associated with an increased risk of developing various diseases, reproductive disorders, and changes in milk production. The present work aims at producing an overview between this disorder and theses outcomes. A meta-analysis of the literature, including 131 different models from 23 papers, or a review when the literature was scarce was conducted. For each outcome, the odds ratio (OR), relative risk, or hazard ratio was presented for various moderators to reduce heterogeneity among the studies. The raw change in milk production associated with SCK was estimated and adjusted, taking into consideration the outcomes known to interact with milk production during the peripartum period. The results showed that 2 main categories of moderators had a significant effect on the adjusted risk. First, the adjustment made by defining SCK as (1) β-hydroxybutyrate concentration >1.4 mM, (2) nonesterified fatty acid (NEFA) concentration >0.4 mM prepartum, or (3) NEFA concentration >1.0 mM postpartum corrected the underestimated risk (despite low significance). This is because several trials reported the relevant risks using lower thresholds for the β-hydroxybutyrate or NEFA values. Using a low threshold leads to lower risk of disease compared with using a high threshold. Second, the correction produced using the polyfactorial terms corrected the overestimation of risk because many trials reported only univariable models. The relative risk or OR (95% confidence interval) related to abomasal displacement, clinical ketosis, early culling and death, metritis, placental retention, clinical mastitis, lameness, and a doubling of the SCC in cases with SCK were 3.33 (2.60-4.25), 5.38 (3.27-8.83), 1.92 (1.60-2.30), 1.75 (1.54-2.01), 1.52 (1.20-1.93), 1.61 (1.24-2.09), 2.01(1.64-2.44), and 1.42 (1.26-1.60), respectively. The precision level of the estimate depended on the outcome. The direct mean ± standard deviation of the 305-d milk losses associated with SCK were 251 ± 73 kg after adjusting for abomasal displacement, clinical ketosis, metritis, and placental retention. The OR (95% confidence interval) for first service calving risk in cases of SCK was 0.67 (0.53-0.83). The calving-to-first-service interval was 8 d longer and the calving-to-conception interval was 16 to 22 d longer in cows with SCK. The relationships among the different reproductive indicators were quantified in only 1 or 2 trials. The present work highlights the need to conduct further studies on the associations between SCK and the risks of diseases, changes in milk production, and reproductive parameters. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Atomic weights of the elements 2011 (IUPAC Technical Report)

USGS Publications Warehouse

Wieser, Michael E.; Holden, Norman; Coplen, Tyler B.; Böhlke, John K.; Berglund, Michael; Brand, Willi A.; De Bièvre, Paul; Gröning, Manfred; Loss, Robert D.; Meija, Juris; Hirata, Takafumi; Prohaska, Thomas; Schoenberg, Ronny; O'Connor, Glenda; Walczyk, Thomas; Yoneda, Shige; Zhu, Xiang-Kun

2013-01-01

The biennial review of atomic-weight determinations and other cognate data has resulted in changes for the standard atomic weights of five elements. The atomic weight of bromine has changed from 79.904(1) to the interval [79.901, 79.907], germanium from 72.63(1) to 72.630(8), indium from 114.818(3) to 114.818(1), magnesium from 24.3050(6) to the interval [24.304, 24.307], and mercury from 200.59(2) to 200.592(3). For bromine and magnesium, assignment of intervals for the new standard atomic weights reflects the common occurrence of variations in the atomic weights of those elements in normal terrestrial materials.

Lack of effect of perampanel on QT interval duration: Results from a thorough QT analysis and pooled partial seizure Phase III clinical trials.

PubMed

Yang, Haichen; Laurenza, Antonio; Williams, Betsy; Patten, Anna; Hussein, Ziad; Ferry, Jim

2015-08-01

Perampanel is a selective, noncompetitive AMPA receptor antagonist approved as adjunctive treatment for partial seizures. To assess potential for delayed cardiac repolarization, a Phase I thorough QT study was performed, supplemented by plasma concentration-QT data modeled from 3 pooled Phase III studies. The Phase I thorough QT study (double-blind, combined fixed-sequence, parallel-group) quantified the effect of perampanel (6 mg once daily for 7 days, followed by dose escalation to a single 8-mg dose, a single 10-mg dose, then 12 mg once daily for 7 days), moxifloxacin positive control (single 400-mg dose on Day 16), and placebo on QT interval duration in healthy subjects (N = 261). Electrocardiograms were recorded at baseline, Day 7 (post 6 mg dose), and Day 16 (post 12 mg dose). Statistical comparisons were between the highest approved perampanel dose (12 mg) versus placebo, a "mid-therapeutic" dose (6 mg) versus placebo, and moxifloxacin versus placebo. Acknowledging that the Phase I thorough QT study could not incorporate a true "supratherapeutic" dose due to length of titration and tolerability concerns in healthy subjects, Phase III studies of perampanel included expanded electrocardiogram safety evaluations specifically intended to support concentration-QT response modeling. The lack of effect of perampanel on the QT interval is shown from pooled analysis of 3 double-blind, placebo-controlled, 19-week, Phase III studies with perampanel doses ≤ 12 mg (N = 1038, total perampanel; and N=442, placebo) in patients with partial seizures. QT measures were corrected for heart rate using Fridericia's (QTcF; the primary endpoint) and Bazett's (QTcB) formulas. In the Phase I thorough QT study, the positive control moxifloxacin caused peak time-matched, baseline-adjusted, placebo-corrected (ΔΔ) QTcF of 12.15 ms at 4h postdose, confirming a drug effect on QTc interval and study assessment sensitivity. Mean baseline-adjusted (Δ) QTcF versus nominal time curves were comparable between perampanel 12 mg and placebo, with most ΔQTcF values being slightly negative. Healthy subjects receiving perampanel 6 and 12 mg doses for 7 days showed no evidence of effects on cardiac repolarization. Peak ΔΔQTcF was 2.34 ms at 1.5h postdose for perampanel 6 mg and 3.92 ms at 0.5h postdose for perampanel 12 mg. At every time point, the upper 95% confidence limit of ΔΔQTcF for perampanel 6 and 12 mg was <10 ms. Phase III studies revealed no clinically significant difference between patients with partial seizures treated with perampanel or placebo in QTcF and QTcB values >450 ms, with no dose-dependent increases or large incremental changes from baseline of >60 ms. Regression analysis of individual plasma perampanel concentrations versus corresponding QTc interval values in Phase I thorough QT and Phase III studies demonstrated no relationship between perampanel concentrations and QT interval duration. Treatment with perampanel 6 mg and 12 mg for 7 days did not delay cardiac repolarization in healthy volunteers. In a population analysis of 1480 patients with partial seizures treated with perampanel doses ≤ 12 mg or placebo, no clinically significant trends in QT interval data were noted. Based on the thorough QT study and evaluations from pooled Phase III studies, there is no evidence of prolonged QT interval duration with perampanel treatment. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Developmental Changes in the Movement Characteristics of the Punt--A Case Study.

ERIC Educational Resources Information Center

Poe, Alison

Punting characteristics of a subject were studied over an 8-year period. Performances were recorded from the age of 2 years 9 months through 11 years 4 months. Fifteen film records were made at 3-month intervals through ages 3 and 4, at 6-month intervals through ages 6 and 7, and at 1-year intervals through ages 8 to 11. Movement characteristics…

Effects of High Intensity Interval Training and Strength Training on Metabolic, Cardiovascular and Hormonal Outcomes in Women with Polycystic Ovary Syndrome: A Pilot Study.

PubMed

Almenning, Ida; Rieber-Mohn, Astrid; Lundgren, Kari Margrethe; Shetelig Løvvik, Tone; Garnæs, Kirsti Krohn; Moholdt, Trine

2015-01-01

Polycystic ovary syndrome is a common endocrinopathy in reproductive-age women, and associates with insulin resistance. Exercise is advocated in this disorder, but little knowledge exists on the optimal exercise regimes. We assessed the effects of high intensity interval training and strength training on metabolic, cardiovascular, and hormonal outcomes in women with polycystic ovary syndrome. Three-arm parallel randomized controlled trial. Thirty-one women with polycystic ovary syndrome (age 27.2 ± 5.5 years; body mass index 26.7 ± 6.0 kg/m2) were randomly assigned to high intensity interval training, strength training, or a control group. The exercise groups exercised three times weekly for 10 weeks. The main outcome measure was change in homeostatic assessment of insulin resistance (HOMA-IR). HOMA-IR improved significantly only after high intensity interval training, by -0.83 (95% confidence interval [CI], -1.45, -0.20), equal to 17%, with between-group difference (p = 0.014). After high intensity interval training, high-density lipoprotein cholesterol increased by 0.2 (95% CI, 0.02, 0.5) mmol/L, with between group difference (p = 0.04). Endothelial function, measured as flow-mediated dilatation of the brachial artery, increased significantly after high intensity interval training, by 2.0 (95% CI, 0.1, 4.0) %, between-group difference (p = 0.08). Fat percentage decreased significantly after both exercise regimes, without changes in body weight. After strength training, anti-Müllarian hormone was significantly reduced, by -14.8 (95% CI, -21.2, -8.4) pmol/L, between-group difference (p = 0.04). There were no significant changes in high-sensitivity C-reactive protein, adiponectin or leptin in any group. High intensity interval training for ten weeks improved insulin resistance, without weight loss, in women with polycystic ovary syndrome. Body composition improved significantly after both strength training and high intensity interval training. This pilot study indicates that exercise training can improve the cardiometabolic profile in polycystic ovary syndrome in the absence of weight loss. ClinicalTrial.gov NCT01919281.

A new technique to determine the correlation between the QT interval and heart-rate for control and SIDS babies

NASA Technical Reports Server (NTRS)

Sadeh, D.; Shannon, D. C.; Abboud, S.; Akselrod, S.; Cohen, R. J.

1987-01-01

The ability of the autonomic nervous system to alter the QT interval in response to heart rate changes is essential to cardiovascular control. An accurate way to determine the relation between QT intervals and their corresponding RR intervals is described. A computer algorithm measures the RR intervals using digital filtering and cross-correlating the QRS sections of consecutive waveforms. The QT intervals is calculated by choosing a section of, the ECG that includes the T wave and cross-correlating it with all the consecutive T waves. At least 4000 pairs of QT-RR intervals are computed for each subject and a best fit correlation function determines the relations between the QT and RR intervals. This technique enables to establish a precise correlation between RR and QT in order to distinguish between control and SIDS babies.

In vivo and in situ monitoring of the nitric oxide stimulus response of single cancer cells by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Su, L.; Chen, Y.; Zhang, G. N.; Wang, L. H.; Shen, A. G.; Zhou, X. D.; Wang, X. H.; Hu, J. M.

2013-04-01

Raman spectroscopy is capable of studying time-resolved information of selected biomolecular distributions inside individual cells without labeling. In this study, Raman spectroscopy was for the first time utilized to in vivo and in situ monitor the cellular response to nitric oxide (NO) in single oral squamous cell carcinoma (OSCC) cells over a period of 24 h. Sodium nitroprusside (SNP) was chosen as a NO donor to be incubated with the OSCC cell line (TCA8113) for certain time intervals. In vivo and in situ Raman analysis revealed that the degradation and conformational changes of nucleic acids, lipids and proteins could be directly observed by changes in the characteristic Raman bands. In comparison with conventional flow cytometric analysis, Raman spectroscopy not only detected more subtle NO-induced chemical changes of cells, where the SNP concentration could be even less than 1 mM, but also provided a full view of the whole chemical components of single cells. Raman spectroscopy therefore is an important candidate for label-free, nondestructive and in situ monitoring of cellular changes in response to chemotherapeutic agents, which could potentially be used in rapid screening of novel drugs.

Modulation of Auditory Cortex Response to Pitch Variation Following Training with Microtonal Melodies

PubMed Central

Zatorre, Robert J.; Delhommeau, Karine; Zarate, Jean Mary

2012-01-01

We tested changes in cortical functional response to auditory patterns in a configural learning paradigm. We trained 10 human listeners to discriminate micromelodies (consisting of smaller pitch intervals than normally used in Western music) and measured covariation in blood oxygenation signal to increasing pitch interval size in order to dissociate global changes in activity from those specifically associated with the stimulus feature that was trained. A psychophysical staircase procedure with feedback was used for training over a 2-week period. Behavioral tests of discrimination ability performed before and after training showed significant learning on the trained stimuli, and generalization to other frequencies and tasks; no learning occurred in an untrained control group. Before training the functional MRI data showed the expected systematic increase in activity in auditory cortices as a function of increasing micromelody pitch interval size. This function became shallower after training, with the maximal change observed in the right posterior auditory cortex. Global decreases in activity in auditory regions, along with global increases in frontal cortices also occurred after training. Individual variation in learning rate was related to the hemodynamic slope to pitch interval size, such that those who had a higher sensitivity to pitch interval variation prior to learning achieved the fastest learning. We conclude that configural auditory learning entails modulation in the response of auditory cortex to the trained stimulus feature. Reduction in blood oxygenation response to increasing pitch interval size suggests that fewer computational resources, and hence lower neural recruitment, is associated with learning, in accord with models of auditory cortex function, and with data from other modalities. PMID:23227019

Electromagnetic-induction logging to monitor changing chloride concentrations

USGS Publications Warehouse

Metzger, Loren F.; Izbicki, John A.

2013-01-01

Water from the San Joaquin Delta, having chloride concentrations up to 3590 mg/L, has intruded fresh water aquifers underlying Stockton, California. Changes in chloride concentrations at depth within these aquifers were evaluated using sequential electromagnetic (EM) induction logs collected during 2004 through 2007 at seven multiple-well sites as deep as 268 m. Sequential EM logging is useful for identifying changes in groundwater quality through polyvinyl chloride-cased wells in intervals not screened by wells. These unscreened intervals represent more than 90% of the aquifer at the sites studied. Sequential EM logging suggested degrading groundwater quality in numerous thin intervals, typically between 1 and 7 m in thickness, especially in the northern part of the study area. Some of these intervals were unscreened by wells, and would not have been identified by traditional groundwater sample collection. Sequential logging also identified intervals with improving water quality—possibly due to groundwater management practices that have limited pumping and promoted artificial recharge. EM resistivity was correlated with chloride concentrations in sampled wells and in water from core material. Natural gamma log data were used to account for the effect of aquifer lithology on EM resistivity. Results of this study show that a sequential EM logging is useful for identifying and monitoring the movement of high-chloride water, having lower salinities and chloride concentrations than sea water, in aquifer intervals not screened by wells, and that increases in chloride in water from wells in the area are consistent with high-chloride water originating from the San Joaquin Delta rather than from the underlying saline aquifer.

Responses of heart rate and blood pressure to KC-135 hyper-gravity

NASA Technical Reports Server (NTRS)

Satake, Hirotaka; Matsunami, Ken'ichi; Reschke, Millard F.

1992-01-01

Many investigators have clarified the effects of hyper gravitational-inertial forces (G) upon the cardiovascular system, using the centrifugal apparatus with short rotating radius. We investigated the cardiovascular responses to KC-135 hyper-G flight with negligibly small angular velocity. Six normal, healthy subjects 29 to 40 years old (5 males and 1 female) took part in this experiment. Hyper gravitational-inertial force was generated by the KC-135 hyper-G flight, flown in a spiral path with a very long radius of 1.5 miles. Hyper-G was sustained for 3 minutes with 1.8 +Gz in each session and was repeatedly exposed to very subject sitting on a chair 5 times. The preliminary results of blood pressure and R-R interval are discussed. An exposure of 1.8 +Gz stress resulted in a remarkable increase of systolic and diastolic blood pressure, while the pulse pressure did not change and remained equal to the control level regardless of an exposure of hyper-G. These results in blood pressure indicate an increase of resistance in the peripheral vessels, when an exposure of hyper-G was applied. The R-R interval was calculated from ECG. R-R interval in all subjects was changed but not systematically, and R-R interval became obviously shorter during the hyper-G period than during the 1 +Gz control period although R-R interval varied widely in some cases. The coefficient of variation of R-R interval was estimated to determine the autonomic nerve activity, but no significant change was detectable.

Interval Graph Limits

PubMed Central

Diaconis, Persi; Holmes, Susan; Janson, Svante

2015-01-01

We work out a graph limit theory for dense interval graphs. The theory developed departs from the usual description of a graph limit as a symmetric function W (x, y) on the unit square, with x and y uniform on the interval (0, 1). Instead, we fix a W and change the underlying distribution of the coordinates x and y. We find choices such that our limits are continuous. Connections to random interval graphs are given, including some examples. We also show a continuity result for the chromatic number and clique number of interval graphs. Some results on uniqueness of the limit description are given for general graph limits. PMID:26405368

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

The use of regression analysis in determining reference intervals for low hematocrit and thrombocyte count in multiple electrode aggregometry and platelet function analyzer 100 testing of platelet function.

PubMed

Kuiper, Gerhardus J A J M; Houben, Rik; Wetzels, Rick J H; Verhezen, Paul W M; Oerle, Rene van; Ten Cate, Hugo; Henskens, Yvonne M C; Lancé, Marcus D

2017-11-01

Low platelet counts and hematocrit levels hinder whole blood point-of-care testing of platelet function. Thus far, no reference ranges for MEA (multiple electrode aggregometry) and PFA-100 (platelet function analyzer 100) devices exist for low ranges. Through dilution methods of volunteer whole blood, platelet function at low ranges of platelet count and hematocrit levels was assessed on MEA for four agonists and for PFA-100 in two cartridges. Using (multiple) regression analysis, 95% reference intervals were computed for these low ranges. Low platelet counts affected MEA in a positive correlation (all agonists showed r 2 ≥ 0.75) and PFA-100 in an inverse correlation (closure times were prolonged with lower platelet counts). Lowered hematocrit did not affect MEA testing, except for arachidonic acid activation (ASPI), which showed a weak positive correlation (r 2 = 0.14). Closure time on PFA-100 testing was inversely correlated with hematocrit for both cartridges. Regression analysis revealed different 95% reference intervals in comparison with originally established intervals for both MEA and PFA-100 in low platelet or hematocrit conditions. Multiple regression analysis of ASPI and both tests on the PFA-100 for combined low platelet and hematocrit conditions revealed that only PFA-100 testing should be adjusted for both thrombocytopenia and anemia. 95% reference intervals were calculated using multiple regression analysis. However, coefficients of determination of PFA-100 were poor, and some variance remained unexplained. Thus, in this pilot study using (multiple) regression analysis, we could establish reference intervals of platelet function in anemia and thrombocytopenia conditions on PFA-100 and in thrombocytopenia conditions on MEA.

The impact of labor-saving technology on first birth intervals in rural Ethiopia.

PubMed

Gibson, Mhairi; Mace, Ruth

2002-02-01

Across the developing world labor-saving technologies introduce considerable savings in the time and energy that women allocate to work. Hormonal studies on natural fertility populations indicate that such a reduction in energetic expenditure (rather than improved nutritional status alone) can lead to increased ovarian function. Other qualitative studies have highlighted a link between labor-saving technology and behavioral changes affecting subsequent age at marriage, which may affect fertility. This biodemographic study was designed to investigate whether these physiological and behavioral changes affect fertility at a population level by focusing on a recent water development scheme in Southern Ethiopia. The demographic consequences of a reduction in women's workload following the installation of water points, specifically the variation in length of first birth interval (time lapsed between marriage and first birth), are investigated. First birth interval length is closely associated with lifetime fertility in populations that do not practice contraception, longer intervals being associated with lower fertility. Using life tables and multivariate hazard modeling techniques a number of significant predictors of first birth interval length are identified. Covariates such as age at marriage, season of marriage, village ecology, and access to improved water supply have significant effects on variation in first birth intervals. When entered into models as a time-varying covariate, access to a water tap stand is associated with an immediate reduction in length of first birth intervals.

Temporal Adaptive Changes in Contractility and Fatigability of Diaphragm Muscles from Streptozotocin-Diabetic Rats

PubMed Central

Brotto, Marco; Brotto, Leticia; Jin, J.-P.; Nosek, Thomas M.; Romani, Andrea

2010-01-01

Diabetes is characterized by ventilatory depression due to decreased diaphragm (DPH) function. This study investigated the changes in contractile properties of rat DPH muscles over a time interval encompassing from 4 days to 14 weeks after the onset of streptozotocin-induced diabetes, with and without insulin treatment for 2 weeks. Maximum tetanic force in intact DPH muscle strips and recovery from fatiguing stimulation were measured. An early (4-day) depression in contractile function in diabetic DPH was followed by gradual improvement in muscle function and fatigue recovery (8 weeks). DPH contractile function deteriorated again at 14 weeks, a process that was completely reversed by insulin treatment. Maximal contractile force and calcium sensitivity assessed in Triton-skinned DPH fibers showed a similar bimodal pattern and the same beneficial effect of insulin treatment. While an extensive analysis of the isoforms of the contractile and regulatory proteins was not conducted, Western blot analysis of tropomyosin suggests that the changes in diabetic DPH response depended, at least in part, on a switch in fiber type. PMID:20467472

Temporal adaptive changes in contractility and fatigability of diaphragm muscles from streptozotocin-diabetic rats.

PubMed

Brotto, Marco; Brotto, Leticia; Jin, J-P; Nosek, Thomas M; Romani, Andrea

2010-01-01

Diabetes is characterized by ventilatory depression due to decreased diaphragm (DPH) function. This study investigated the changes in contractile properties of rat DPH muscles over a time interval encompassing from 4 days to 14 weeks after the onset of streptozotocin-induced diabetes, with and without insulin treatment for 2 weeks. Maximum tetanic force in intact DPH muscle strips and recovery from fatiguing stimulation were measured. An early (4-day) depression in contractile function in diabetic DPH was followed by gradual improvement in muscle function and fatigue recovery (8 weeks). DPH contractile function deteriorated again at 14 weeks, a process that was completely reversed by insulin treatment. Maximal contractile force and calcium sensitivity assessed in Triton-skinned DPH fibers showed a similar bimodal pattern and the same beneficial effect of insulin treatment. While an extensive analysis of the isoforms of the contractile and regulatory proteins was not conducted, Western blot analysis of tropomyosin suggests that the changes in diabetic DPH response depended, at least in part, on a switch in fiber type.

Monitoring physical and chemical parameters of Delaware Bay waters with an ERTS-1 data collection platform

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Wethe, C.

1975-01-01

The author has identified the following significant results. Results of the analysis of data collected during the summer of 1974 demonstrate that the ERTS Data Collection Platform (DCP) is quite responsive to changing water parameters and that this information can be successfully transmitted under all weather conditions. The monitoring of on-site probe outputs reveals a rapid response to changing water temperature, salinity, and turbidity conditions on incoming tides as the tidal salt wedge passes the probe location. The changes in water properties were corroborated by simultaneously sampling the water for subsequent laboratory analysis. Fluctuations observed in the values of salinity, conductivity, temperature and water depth over short time intervals were extremely small. Due to the nature of the probe, 10% to 20% fluctuations were observed in the turbidity values. The use of the average of the values observed during an overpass provided acceptable results. Good quality data was obtained from the satellite on each overpass regardless of weather conditions. Continued use of the DCP will help provide an indication of the accuracy of the probes and transmission system during long term use.

Kinetic energy budget during strong jet stream activity over the eastern United States

NASA Technical Reports Server (NTRS)

Fuelberg, H. E.; Scoggins, J. R.

1980-01-01

Kinetic energy budgets are computed during a cold air outbreak in association with strong jet stream activity over the eastern United States. The period is characterized by large generation of kinetic energy due to cross-contour flow. Horizontal export and dissipation of energy to subgrid scales of motion constitute the important energy sinks. Rawinsonde data at 3 and 6 h intervals during a 36 h period are used in the analysis and reveal that energy fluctuations on a time scale of less than 12 h are generally small even though the overall energy balance does change considerably during the period in conjunction with an upper level trough which moves through the region. An error analysis of the energy budget terms suggests that this major change in the budget is not due to random errors in the input data but is caused by the changing synoptic situation. The study illustrates the need to consider the time and space scales of associated weather phenomena in interpreting energy budgets obtained through use of higher frequency data.

Does preprocessing change nonlinear measures of heart rate variability?

PubMed

Gomes, Murilo E D; Guimarães, Homero N; Ribeiro, Antônio L P; Aguirre, Luis A

2002-11-01

This work investigated if methods used to produce a uniformly sampled heart rate variability (HRV) time series significantly change the deterministic signature underlying the dynamics of such signals and some nonlinear measures of HRV. Two methods of preprocessing were used: the convolution of inverse interval function values with a rectangular window and the cubic polynomial interpolation. The HRV time series were obtained from 33 Wistar rats submitted to autonomic blockade protocols and from 17 healthy adults. The analysis of determinism was carried out by the method of surrogate data sets and nonlinear autoregressive moving average modelling and prediction. The scaling exponents alpha, alpha(1) and alpha(2) derived from the detrended fluctuation analysis were calculated from raw HRV time series and respective preprocessed signals. It was shown that the technique of cubic interpolation of HRV time series did not significantly change any nonlinear characteristic studied in this work, while the method of convolution only affected the alpha(1) index. The results suggested that preprocessed time series may be used to study HRV in the field of nonlinear dynamics.

Determination of Trophic State Changes with Diel Dissolved Oxygen: A Case Study in a Shallow Lake.

PubMed

Xu, Zhen; Xu, Y Jun

2015-11-01

Current trophic state indices (TSI) have been reported to have limitations in assessing changes in eutrophication status of shallow waters. This study aimed to use intensive measurements on dissolved oxygen (DO) to improve the determination of tropic state changes. The authors deployed an environment monitoring buoy in a eutrophic shallow lake and recorded water temperature, DO, and chlorophyll-a concentrations at 15-minute intervals for two 1-year periods: from August 2008 to July 2009 and from August 2013 to July 2014. In addition, they recorded water levels over the same periods and collected water samples for nutrient analysis. The authors analyzed the high-time resolution DO records, compared the diel DO trends between the two 1-year periods, and proposed a new TSI using DO. They found that analyzing the change in diel DO ranges can improve commonly used methods for classifying trophic states and assessing the change of eutrophication status of waterbodies.

A case study of carbon fluxes from land change in the southwest Brazilian Amazon

USGS Publications Warehouse

Barrett, K.; Rogan, J.; Eastman, J.R.

2009-01-01

Worldwide, land change is responsible for one-fifth of anthropogenic carbon emissions. In Brazil, three-quarters of carbon emissions originate from land change. This study represents a municipal-scale study of carbon fluxes from vegetation in Rio Branco, Brazil. Land-cover maps of pasture, forest, and secondary growth from 1993, 1996, 1999, and 2003 were produced using an unsupervised classification method (overall accuracy = 89%). Carbon fluxes from land change over the decade of imagery were estimated from transitions between land-cover categories for each time interval. This article presents new methods for estimating emissions reductions from carbon stored in the vegetation that replaces forests (e.g., pasture) and sequestration by new (>10-15 years) forests, which reduced gross emissions by 16, 15, and 22% for the period of 1993-1996, 1996-1999, and 1999-2003, respectively. The methods used in the analysis are broadly applicable and provide a comprehensive characterization of regional-scale carbon fluxes from land change.

Implementation of standardized follow-up care significantly reduces peritonitis in children on chronic peritoneal dialysis.

PubMed

Neu, Alicia M; Richardson, Troy; Lawlor, John; Stuart, Jayne; Newland, Jason; McAfee, Nancy; Warady, Bradley A

2016-06-01

The Standardizing Care to improve Outcomes in Pediatric End stage renal disease (SCOPE) Collaborative aims to reduce peritonitis rates in pediatric chronic peritoneal dialysis patients by increasing implementation of standardized care practices. To assess this, monthly care bundle compliance and annualized monthly peritonitis rates were evaluated from 24 SCOPE centers that were participating at collaborative launch and that provided peritonitis rates for the 13 months prior to launch. Changes in bundle compliance were assessed using either a logistic regression model or a generalized linear mixed model. Changes in average annualized peritonitis rates over time were illustrated using the latter model. In the first 36 months of the collaborative, 644 patients with 7977 follow-up encounters were included. The likelihood of compliance with follow-up care practices increased significantly (odds ratio 1.15, 95% confidence interval 1.10, 1.19). Mean monthly peritonitis rates significantly decreased from 0.63 episodes per patient year (95% confidence interval 0.43, 0.92) prelaunch to 0.42 (95% confidence interval 0.31, 0.57) at 36 months postlaunch. A sensitivity analysis confirmed that as mean follow-up compliance increased, peritonitis rates decreased, reaching statistical significance at 80% at which point the prelaunch rate was 42% higher than the rate in the months following achievement of 80% compliance. In its first 3 years, the SCOPE Collaborative has increased the implementation of standardized follow-up care and demonstrated a significant reduction in average monthly peritonitis rates. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Contactless magnetocardiographic mapping in anesthetized Wistar rats: evidence of age-related changes of cardiac electrical activity.

PubMed

Brisinda, Donatella; Caristo, Maria Emiliana; Fenici, Riccardo

2006-07-01

Magnetocardiography (MCG) is the recording of the magnetic field (MF) generated by cardiac electrophysiological activity. Because it is a contactless method, MCG is ideal for noninvasive cardiac mapping of small experimental animals. The aim of this study was to assess age-related changes of cardiac intervals and ventricular repolarization (VR) maps in intact rats by means of MCG mapping. Twenty-four adult Wistar rats (12 male and 12 female) were studied, under anesthesia, with the same unshielded 36-channel MCG instrumentation used for clinical recordings. Two sets of measurements were obtained from each animal: 1) at 5 mo of age (297.5 +/- 21 g body wt) and 2) at 14 mo of age (516.8 +/- 180 g body wt). RR and PR intervals, QRS segment, and QTpeak, QTend, JTpeak, JTend, and Tpeak-end were measured from MCG waveforms. MCG imaging was automatically obtained as MF maps and as inverse localization of cardiac sources with equivalent current dipole and effective magnetic dipole models. After 300 s of continuous recording were averaged, the signal-to-noise ratio was adequate for study of atrial and ventricular MF maps and for three-dimensional localization of the underlying cardiac sources. Clear-cut age-related differences in VR duration were demonstrated by significantly longer QTend, JTend, and Tpeak-end in older Wistar rats. Reproducible multisite noninvasive cardiac mapping of anesthetized rats is simpler with MCG methodology than with ECG recording. In addition, MCG mapping provides new information based on quantitative analysis of MF and equivalent sources. In this study, statistically significant age-dependent variations in VR intervals were found.

Evaluation of SAMe-TT2R2 Score on Predicting Success With Extended-Interval Warfarin Monitoring.

PubMed

Hwang, Andrew Y; Carris, Nicholas W; Dietrich, Eric A; Gums, John G; Smith, Steven M

2018-06-01

In patients with stable international normalized ratios, 12-week extended-interval warfarin monitoring can be considered; however, predictors of success with this strategy are unknown. The previously validated SAMe-TT 2 R 2 score (considering sex, age, medical history, treatment, tobacco, and race) predicts anticoagulation control during standard follow-up (every 4 weeks), with lower scores associated with greater time in therapeutic range. To evaluate the ability of the SAMe-TT 2 R 2 score in predicting success with extended-interval warfarin follow-up in patients with previously stable warfarin doses. In this post hoc analysis of a single-arm feasibility study, baseline SAMe-TT 2 R 2 scores were calculated for patients with ≥1 extended-interval follow-up visit. The primary analysis assessed achieved weeks of extended-interval follow-up according to baseline SAMe-TT 2 R 2 scores. A total of 47 patients receiving chronic anticoagulation completed a median of 36 weeks of extended-interval follow-up. The median baseline SAMe-TT 2 R 2 score was 1 (range 0-5). Lower SAMe-TT 2 R 2 scores appeared to be associated with greater duration of extended-interval follow-up achieved, though the differences between scores were not statistically significant. No individual variable of the SAMe-TT 2 R 2 score was associated with achieved weeks of extended-interval follow-up. Analysis of additional patient factors found that longer duration (≥24 weeks) of prior stable treatment was significantly associated with greater weeks of extended-interval follow-up completed ( P = 0.04). Conclusion and Relevance: This pilot study provides limited evidence that the SAMe-TT 2 R 2 score predicts success with extended-interval warfarin follow-up but requires confirmation in a larger study. Further research is also necessary to establish additional predictors of successful extended-interval warfarin follow-up.

Minimizing pre- and post-defibrillation pauses increases the likelihood of return of spontaneous circulation (ROSC).

PubMed

Sell, Rebecca E; Sarno, Renee; Lawrence, Brenna; Castillo, Edward M; Fisher, Roger; Brainard, Criss; Dunford, James V; Davis, Daniel P

2010-07-01

The three-phase model of ventricular fibrillation (VF) arrest suggests a period of compressions to "prime" the heart prior to defibrillation attempts. In addition, post-shock compressions may increase the likelihood of return of spontaneous circulation (ROSC). The optimal intervals for shock delivery following cessation of compressions (pre-shock interval) and resumption of compressions following a shock (post-shock interval) remain unclear. To define optimal pre- and post-defibrillation compression pauses for out-of-hospital cardiac arrest (OOHCA). All patients suffering OOHCA from VF were identified over a 1-month period. Defibrillator data were abstracted and analyzed using the combination of ECG, impedance, and audio recording. Receiver-operator curve (ROC) analysis was used to define the optimal pre- and post-shock compression intervals. Multiple logistic regression analysis was used to quantify the relationship between these intervals and ROSC. Covariates included cumulative number of defibrillation attempts, intubation status, and administration of epinephrine in the immediate pre-shock compression cycle. Cluster adjustment was performed due to the possibility of multiple defibrillation attempts for each patient. A total of 36 patients with 96 defibrillation attempts were included. The ROC analysis identified an optimal pre-shock interval of <3s and an optimal post-shock interval of <6s. Increased likelihood of ROSC was observed with a pre-shock interval <3s (adjusted OR 6.7, 95% CI 2.0-22.3, p=0.002) and a post-shock interval of <6s (adjusted OR 10.7, 95% CI 2.8-41.4, p=0.001). Likelihood of ROSC was substantially increased with the optimization of both pre- and post-shock intervals (adjusted OR 13.1, 95% CI 3.4-49.9, p<0.001). Decreasing pre- and post-shock compression intervals increases the likelihood of ROSC in OOHCA from VF.

Integrating bio-, chemo- and sequence stratigraphy of the Late Ordovician, Early Katian: A connection between onshore and offshore facies using carbon isotope analysis: Kentucky, Ohio, USA

NASA Astrophysics Data System (ADS)

Young, Allison; Brett, Carlton; McLaughlin, Patrick

2017-04-01

A common problem in stratigraphic correlation is the difficulty of bridging shallow water shelf carbonates and down ramp shale-rich facies. This issue is well exemplified by the Upper Ordovician (lower Katian) Lexington Limestone of Kentucky, USA and adjacent dark shale facies in the deeper water Sebree Trough, an elongate, narrow bathymetric low abruptly north of the outcrop belt in the Ohio subsurface. Chronostratigraphic schemes for this interval have been proposed on the basis of conodont and graptolite biostratigraphy, mapping of event beds, and sequence stratigraphy through facies analysis. The relation of the siliciclastic rich offshore records of the "Point Pleasant-Utica" interval, well known to drillers because of its oil and gas potential, with the up-ramp shallow water carbonate dominated equivalents of the Lexington Formation is complicated by convoluted nomenclature, a major, abrupt change in facies, and disparity in the availability and completeness of records. Current genetic models of organic rich shale intervals, such as the Point Pleasant-Utica interval, are still lacking in detail, and will greatly benefit from detailed correlation with shallow water settings where more is understood about paleoclimatic conditions. In order to understand the development and evolution of this Late Ordovician Laurentian basin, it is important to understand the age relationships of depositional processes occurring at a range of depths, particularly in the less well studied epeiric sea setting of the "Point Pleasant-Utica" interval of Ohio and partial lateral equivalent, Lexington Formation of central Kentucky. The outcrop area of central Kentucky, exposed by the later uplift of the Cincinnati Arch, hosts numerous world-class exposures of the Lexington Formation, nearly all of which are representative of the highly fossiliferous, shallow-water marine platform carbonates. These successions display well differentiated depositional sequences, with sharp facies offsets, and mineralized surfaces. They also contain well studied fossil assemblages and event beds, which at the scale of an outcrop, allow for detailed paleoenvironmental interpretation. The offshore record of this interval, known almost exclusively from a few drill cores, displays an abrupt transition to distal, siliciclastic dominated facies, recording a more dysoxic and organic rich interval. Internal correlation of these shales has relied mostly on limited graptolite biostratigraphic and geochemical analysis. Here we seek to establish age relationships across a major facies transition between these two interrelated paleoenvironmental settings using high resolution whole rock carbon isotope analysis to integrate new and previous work on lithostratigraphy, biostratigraphy, and sequence stratigraphy of a series of cores and outcrops. Results to date demonstrate the persistence of carbon isotopic patterns (including the globally recognized GICE positive carbon isotopic excursion) permitting extension of correlation into basinal facies where tracking of stratigraphic sequences becomes difficult. A complicated relationship across the region is emerging involving both rapid facies transitions and submarine erosional cutout of units toward the center of the Sebree Trough. This study demonstrates the utility of an integrated stratigraphic approach for establishing high resolution regional correlations allowing for interpretations across a major facies transitions.

Inefficiencies and high-value improvements in U.S. cervical cancer screening practice: A cost-effectiveness analysis

PubMed Central

Kim, Jane J.; Campos, Nicole G.; Sy, Stephen; Burger, Emily A.; Cuzick, Jack; Castle, Philip E.; Hunt, William C.; Waxman, Alan; Wheeler, Cosette M.

2016-01-01

Background Studies suggest that cervical cancer screening practice in the United States is inefficient. The cost and health implications of non-compliance in the screening process compared to recommended guidelines are uncertain. Objective To estimate the benefits, costs, and cost-effectiveness of current cervical cancer screening practice and assess the value of screening improvements. Design Model-based cost-effectiveness analysis. Data Sources New Mexico HPV Pap Registry; medical literature. Target Population Cohort of women eligible for routine screening. Time Horizon Lifetime. Perspective Societal. Interventions Current cervical cancer screening practice; improved compliance to guidelines-based screening interval, triage testing, diagnostic referrals, and precancer treatment referrals. Outcome Measures Reductions in lifetime cervical cancer risk, quality-adjusted life-years (QALYs), lifetime costs, incremental cost-effectiveness ratios (ICERs), incremental net monetary benefits (INMBs Results of Base-Case Analysis Current screening practice was associated with lower health benefit and was not cost-effective relative to guidelines-based strategies. Improvements in the screening process were associated with higher QALYs and small changes in costs. Perfect c4mpliance to a 3-yearly screening interval and to colposcopy/biopsy referrals were associated with the highest INMBs ($759 and $741, respectively, at a willingness-to-pay threshold of $100,000 per QALY gained); together, the INMB increased to $1,645. Results of Sensitivity Analysis Current screening practice was inefficient in 100% of simulations. The rank ordering of screening improvements according to INMBs was stable over a range of screening inputs and willingness-to-pay thresholds. Limitations The impact of HPV vaccination was not considered. Conclusions The added health benefit of improving compliance to guidelines, especially the 3-yearly interval for cytology screening and diagnostic follow-up, may justify additional investments in interventions to improve U.S. cervical cancer screening practice. Funding Source U.S. National Cancer Institute. PMID:26414147

Using Musical Intervals to Demonstrate Superposition of Waves and Fourier Analysis

ERIC Educational Resources Information Center

LoPresto, Michael C.

2013-01-01

What follows is a description of a demonstration of superposition of waves and Fourier analysis using a set of four tuning forks mounted on resonance boxes and oscilloscope software to create, capture and analyze the waveforms and Fourier spectra of musical intervals.

A Limitation of the Applicability of Interval Shift Analysis to Program Evaluation

ERIC Educational Resources Information Center

Hardy, Roy

1975-01-01

Interval Shift Analysis (ISA) is an adaptation of the linear programming model used to determine maximum benefits or minimal losses in quantifiable economics problems. ISA is applied to pre and posttest score distributions for 43 classes of second graders. (RC)

Melodic interval perception by normal-hearing listeners and cochlear implant users

PubMed Central

Luo, Xin; Masterson, Megan E.; Wu, Ching-Chih

2014-01-01

The perception of melodic intervals (sequential pitch differences) is essential to music perception. This study tested melodic interval perception in normal-hearing (NH) listeners and cochlear implant (CI) users. Melodic interval ranking was tested using an adaptive procedure. CI users had slightly higher interval ranking thresholds than NH listeners. Both groups' interval ranking thresholds, although not affected by root note, significantly increased with standard interval size and were higher for descending intervals than for ascending intervals. The pitch direction effect may be due to a procedural artifact or a difference in central processing. In another test, familiar melodies were played with all the intervals scaled by a single factor. Subjects rated how in tune the melodies were and adjusted the scaling factor until the melodies sounded the most in tune. CI users had lower final interval ratings and less change in interval rating as a function of scaling factor than NH listeners. For CI users, the root-mean-square error of the final scaling factors and the width of the interval rating function were significantly correlated with the average ranking threshold for ascending rather than descending intervals, suggesting that CI users may have focused on ascending intervals when rating and adjusting the melodies. PMID:25324084

Change detection and change blindness in pigeons (Columba livia).

PubMed

Herbranson, Walter T; Trinh, Yvan T; Xi, Patricia M; Arand, Mark P; Barker, Michael S K; Pratt, Theodore H

2014-05-01

Change blindness is a phenomenon in which even obvious details in a visual scene change without being noticed. Although change blindness has been studied extensively in humans, we do not yet know if it is a phenomenon that also occurs in other animals. Thus, investigation of change blindness in a nonhuman species may prove to be valuable by beginning to provide some insight into its ultimate causes. Pigeons learned a change detection task in which pecks to the location of a change in a sequence of stimulus displays were reinforced. They were worse at detecting changes if the stimulus displays were separated by a brief interstimulus interval, during which the display was blank, and this primary result matches the general pattern seen in previous studies of change blindness in humans. A second experiment attempted to identify specific stimulus characteristics that most reliably produced a failure to detect changes. Change detection was more difficult when interstimulus intervals were longer and when the change was iterated fewer times. ©2014 APA, all rights reserved.

Simple estimation procedures for regression analysis of interval-censored failure time data under the proportional hazards model.

PubMed

Sun, Jianguo; Feng, Yanqin; Zhao, Hui

2015-01-01

Interval-censored failure time data occur in many fields including epidemiological and medical studies as well as financial and sociological studies, and many authors have investigated their analysis (Sun, The statistical analysis of interval-censored failure time data, 2006; Zhang, Stat Modeling 9:321-343, 2009). In particular, a number of procedures have been developed for regression analysis of interval-censored data arising from the proportional hazards model (Finkelstein, Biometrics 42:845-854, 1986; Huang, Ann Stat 24:540-568, 1996; Pan, Biometrics 56:199-203, 2000). For most of these procedures, however, one drawback is that they involve estimation of both regression parameters and baseline cumulative hazard function. In this paper, we propose two simple estimation approaches that do not need estimation of the baseline cumulative hazard function. The asymptotic properties of the resulting estimates are given, and an extensive simulation study is conducted and indicates that they work well for practical situations.

The development of convective instability, wind shear, and vertical motion in relation to convection activity and synoptic systems in AVE 4

NASA Technical Reports Server (NTRS)

Davis, J. G.; Scoggins, J. R.

1981-01-01

Data from the Fourth Atmospheric Variability Experiment were used to investigate conditions/factors responsible for the development (local time rate-of-change) of convective instability, wind shear, and vertical motion in areas with varying degrees of convective activity. AVE IV sounding data were taken at 3 or 6 h intervals during a 36 h period on 24-25 April 1975 over approximately the eastern half of the United States. An error analysis was performed for each variable studied.

The Processing and Analysis of the Data from an Air Force Geophysics Laboratory Atmospheric Optical Measurement Station and the Maintenance of the Central Data Logger System.

DTIC Science & Technology

1984-02-15

Directory ... ....... 42 19. Sample Interval Monitor Graph ................. 46 vi vii LIST OF FIGURES P age I. Example of DATA PROFILE Plot...Final Report, AFGL-TR-81-0130, ADA1? 7879 . PART I. RAW DATA TAPE PROCESSING PROCEDURES. 1.1 EXPERIMENT SAMPLING SEQUENCES Due to the changing...Data Quality 79 QQQQ Packed Eltro Data Quality 80 QQQQQQQQ Packed Luxmeter Data Quality 8i QQOQ Packed Night Path Data Quality P? QQQQQQQ Packed Vis

Variation of the transmittance spectrum of a polymer cladding optical fibre for the influence of hydrocarbons and changes in temperature

NASA Astrophysics Data System (ADS)

Santoyo, A. T.; Shlyagin, M. G.; Mendieta, F. J.; Spirin, V.; de Rivera, L. N.

2005-12-01

We develop an analysis of the behavior of an evanescent field fiber optic sensor under different conditions for its optimization. This paper presents results of an experimental study of the spectral characteristics of a polymer cladding optical fiber exposed to different analytes. The measurements were performed in the spectral interval from 1100 to 1800 nanometers in a temperature range from 5 to 50 degrees C. Influence of ambient temperature on the optical fiber transmittance was found to be strongly dependent on wavelength.

Computer Assisted Thermography And Its Application In Ovulation Detection

NASA Astrophysics Data System (ADS)

Rao, K. H.; Shah, A. V.

1984-08-01

Hardware and software of a computer-assisted image analyzing system used for infrared images in medical applications are discussed. The application of computer-assisted thermography (CAT) as a complementary diagnostic tool in centralized diagnostic management is proposed. The authors adopted 'Computer Assisted Thermography' to study physiological changes in the breasts related to the hormones characterizing the menstrual cycle of a woman. Based on clinical experi-ments followed by thermal image analysis, they suggest that 'differential skin temperature (DST)1 be measured to detect the fertility interval in the menstrual cycle of a woman.

Do changes of 6-minute walk distance predict clinical events in patients with pulmonary arterial hypertension? A meta-analysis of 22 randomized trials.

PubMed

Savarese, Gianluigi; Paolillo, Stefania; Costanzo, Pierluigi; D'Amore, Carmen; Cecere, Milena; Losco, Teresa; Musella, Francesca; Gargiulo, Paola; Marciano, Caterina; Perrone-Filardi, Pasquale

2012-09-25

The objectives of this study were to verify whether improvement in 6-min walk distance (6MWD) is associated with clinical outcome in pulmonary arterial hypertension (PAH). 6MWD is used as an endpoint to assess the benefit of therapies in PAH. However, whether changes in 6MWD correlate with clinical outcome is unknown. Randomized trials assessing 6MWD in patients with PAH and reporting clinical endpoints were included in a meta-analysis. The meta-analysis was performed to assess the influence of treatment on outcomes. Meta-regression analysis was performed to test the relationship between 6MWD changes and outcomes. Twenty-two trials enrolling 3,112 participants were included. Active treatments led to significant reduction of all-cause death (odds ratio [OR]: 0.429; 95% confidence interval [CI]: 0.277 to 0.664; p < 0.01), hospitalization for PAH, and/or lung or heart-lung transplantation (OR: 0.442; 95% CI: 0.309 to 0.632; p < 0.01), initiation of PAH rescue therapy (OR: 0.555; 95% CI: 0.347 to 0.889; p = 0.01), and composite outcome (OR: 0.400; 95% CI: 0.313 to 0.510; p < 0.01). No relationship between 6MWD changes and outcomes was detected. In patients with PAH, improvement in 6MWD does not reflect benefit in clinical outcomes. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Bimanual coordination of bowing and fingering in violinists--effects of position changes and string changes.

PubMed

Kazennikov, Oleg; Wiesendanger, Mario

2009-07-01

Music performance is based on demanding motor control with much practice from young age onward. We have chosen to investigate basic bimanual movements played by violin amateurs and professionals. We posed the question whether position and string changes, two frequent mechanisms, may influence the time interval bowing (right)-fingering (left) coordination. The objective was to measure bimanual coordination, i.e., with or without position changes and string changes. The tendency was that the bimanual coordination was statistically only slightly increased or even unchanged but not perceptible. We conclude that the coordination index is limited up to 100 ms intervals, without any erroneous perception. Although the mentioned position changes and string changes are movements with their timing, they are executed in parallel rather than in series with the bow-fingering coordination.

Quantitative anatomical and behavioral analyses of regeneration and collateral sprouting following spinal cord transection in the nurse shark (ginglymostoma cirratum).

PubMed

Gelderd, J B

1979-01-01

The spinal cord was transected at the mid-thoracic level in 32 nurse sharks. Four animals per group were sacrificed at intervals of 10, 20, 30, 40, 60 and 90 days postoperative. Two groups of fish underwent a subsequent spinla1 cord retransection at the same site at 90 days and were sacrificed 10 and 20 days later. Three sections of spinal cord were removed from each shark for histological analysis. Behaviorally, timed trials for swimming speed and a strength test for axial musculature contraction caudal to the lesion site were performed at 5 day postoperative intervals. Histological analysis showed little regeneration (9-13 percent) of two descending tracts 90 days following the lesion and no return of rostrally controlled movements caudal to the lesion. However, synaptic readjustment did occur caudal to the lesion. This phenomenon was attributed to local segmental sprouting of adjacent, intact nerve fibers. A close correlation was shown between this synaptic readjustment and the strength of uncontrollable undulatory movements seen caudal to the lesion site following spinal cord transection. The relationship of regeneration and collateral sprouting to quantitative behavioral changes is discussed.

Autonomic nervous function in patients with Meniere's disease evaluated by power spectral analysis of heart rate variability.

PubMed

Yamada, M; Mizuta, K; Ito, Y; Furuta, M; Sawai, S; Miyata, H

1999-10-01

A hypothesis has been advanced that the autonomic nervous dysfunction (AND) relates to the development of vertigo in Meniere's disease (MD). We also studied the causal relationship between AND and vertigo in MD. We evaluated autonomic nervous function in 17 patients with MD (five men and 12 women ranging in age from 16 to 70 years) by classifying them by their stages of attack and interval of vertigo and with power spectral analysis (PSA) of heart rate variability. Fourteen healthy volunteers were also tested as controls. At the interval stage, parasympathetic nervous hypofunction and significant depression of sympathetic response due to postural changes from the supine to the standing position were observed in many of those patients. At the attack stage, sympathetic nervous hypofunction was observed in some of the patients. These findings lead us to the conclusion that AND relates to vertigo in MD as a predisposing factor. However, the question of whether AND relates as a trigger or as a consequence of vertigo in MD has not been adequately solved in this study. We will make further studies on circadian variation of autonomic nervous function.

Quantification of Uncertainty in the Flood Frequency Analysis

NASA Astrophysics Data System (ADS)

Kasiapillai Sudalaimuthu, K.; He, J.; Swami, D.

2017-12-01

Flood frequency analysis (FFA) is usually carried out for planning and designing of water resources and hydraulic structures. Owing to the existence of variability in sample representation, selection of distribution and estimation of distribution parameters, the estimation of flood quantile has been always uncertain. Hence, suitable approaches must be developed to quantify the uncertainty in the form of prediction interval as an alternate to deterministic approach. The developed framework in the present study to include uncertainty in the FFA discusses a multi-objective optimization approach to construct the prediction interval using ensemble of flood quantile. Through this approach, an optimal variability of distribution parameters is identified to carry out FFA. To demonstrate the proposed approach, annual maximum flow data from two gauge stations (Bow river at Calgary and Banff, Canada) are used. The major focus of the present study was to evaluate the changes in magnitude of flood quantiles due to the recent extreme flood event occurred during the year 2013. In addition, the efficacy of the proposed method was further verified using standard bootstrap based sampling approaches and found that the proposed method is reliable in modeling extreme floods as compared to the bootstrap methods.

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.

Detecting depth gradients in the mid-Cretaceous Western Interior Seaway

NASA Astrophysics Data System (ADS)

Bryant, R.

2017-12-01

Multivariate data sets can be simplified using techniques like ordination and detrended correspondence analysis to identify important ecological gradients such as water depth, and thus provide insight into the environmental distribution of species (Patzkowsky & Holland, 2012). Here, these methods will be applied to abundance data of foraminiferal assemblages from the Western Interior Seaway through the Cenomanian/Turonian boundary ( 94-93 Ma). Through this interval the seaway experienced rapid and abrupt environmental and oceanographic changes, including the onset of Oceanic Anoxic Event 2 (OAE2) and peak transgression. The intense ocean and biosphere changes are well documented in the WIS, but the effect of OAE2 coupled with rising sea level on foraminiferal communities across the seaway is still poorly understood.