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Background Occlusions of intravenous (IV) tubing can prevent vital and time-critical medication or solutions from being delivered into the bloodstream of patients receiving IV therapy. At low flow rates (≤ 1 ml/h) the alarm delay (time to an alert to the user) can be up to 2 h using conventional pressure threshold algorithms. In order to reduce alarm delays we developed and evaluated the performance of two new real-time occlusion detection algorithms and one co-occlusion detector that determines the correlation in trends in pressure changes for multiple pumps. Methods Bench-tested experimental runs were recorded in triplicate at rates of 1, 2, 4, 8, 16, and 32 ml/h. Each run consisted of 10 min of non-occluded infusion followed by a period of occluded infusion of 10 min or until a conventional occlusion alarm at 400 mmHg occurred. The first algorithm based on binary logistic regression attempts to detect occlusions based on the pump’s administration rate Q(t) and pressure sensor readings P(t). The second algorithm continuously monitored whether the actual variation in the pressure exceeded a threshold of 2 standard deviations (SD) above the baseline pressure. When a pump detected an occlusion using the SD algorithm, a third algorithm correlated the pressures of multiple pumps to detect the presence of a shared occlusion. The algorithms were evaluated using 6 bench-tested baseline single-pump occlusion scenarios, 9 single-pump validation scenarios and 7 multi-pump co-occlusion scenarios (i.e. with flow rates of 1 + 1, 1 + 2, 1 + 4, 1 + 8, 1 + 16, and 1 + 32 ml/h respectively). Alarm delay was the primary performance measure. Results In the baseline single-pump occlusion scenarios, the overall mean ± SD alarm delay of the regression and SD algorithms were 1.8 ± 0.8 min and 0.4 ± 0.2 min, respectively. Compared to the delay of the conventional alarm this corresponds to a mean time reduction of 76% (P = 0.003) and 95% (P = 0.001), respectively. In the validation scenarios the overall mean ± SD alarm delay of the regression and SD algorithms were respectively 1.8 ± 1.6 min and 0.3 ± 0.2 min, corresponding to a mean time reduction of 77% and 95%. In the multi-pump scenarios a correlation > 0.8 between multiple pump pressures after initial occlusion detection by the SD algorithm had a mean ± SD alarm delay of 0.4 ± 0.2 min. In 2 out of the 9 validation scenarios an occlusion was not detected by the regression algorithm before a conventional occlusion alarm occurred. Otherwise no occlusions were missed. Conclusions In single pumps, both the regression and SD algorithm considerably reduced alarm delay compared to conventional pressure limit-based detection. The SD algorithm appeared to be more robust than the regression algorithm. For multiple pumps the correlation algorithm reliably detected co-occlusions. The latter may be used to localize the segment of tubing in which the occlusion occurs. Trial registration Not applicable.

Digital neuropsychological test batteries are popular in college athletics; however, well-validated digital tests that are short and portable are needed to expand the feasibility of performing cognitive testing quickly, reliably, and outside standard clinical settings. This study assessed performance on digital versions of Trail Making Test (dTMT) and a modified Symbol Digit Modalities Test (dSDMT) in uninjured collegiate athletes (n = 537; 47% female) using the C3Logix baseline assessment module. Time to complete (dTMT) and the number of correct responses (dSDMT) were computed, transformed into z scores, and compared to age-matched normative data from analogous paper-and-pencil tests. Overall sample performance was compared to normative sample performance using Cohen's d. Sample averages on the dTMT, Part A, and dSDMT were similar to published norms; 97 and 92% of z scores fell within 2 standard deviations of normative means, respectively. The sample averaged faster completion times on dTMT, Part B than published norms, although 98% of z scores were within 2 standard deviations of the normative means. Brief, digitized tests may be useful in populations and testing environments when longer cognitive test batteries are impractical. Future studies should assess the ability of these tests to detect clinically relevant changes following a suspected head injury.

We present a statistical framework to identify regional signals in station-based CO2 time series with minimal local influence. A curve-fitting function is first applied to the detrended time series to derive a harmonic describing the annual CO2 cycle. We then combine a polynomial fit to the data with a short-term residual filter to estimate the smoothed cycle and define a seasonally adjusted noise component, equal to 2 standard deviations of the smoothed cycle about the annual cycle. Spikes in the smoothed daily data which surpass this ±2σ threshold are classified as anomalies. Examining patterns of anomalous behavior across multiple sites allows us to quantify the impacts of synoptic-scale atmospheric transport events and better understand the regional carbon cycling implications of extreme seasonal occurrences such as droughts.

A dynamic finite element model of a shod running footstrike was developed and driven with 6 degree of freedom foot segment kinematics determined from a motion capture running trial. Quadratic tetrahedral elements were used to mesh the footwear components with material models determined from appropriate mechanical tests. Model outputs were compared with experimental high-speed video (HSV) footage, vertical ground reaction force (GRF), and center of pressure (COP) excursion to determine whether such an approach is appropriate for the development of athletic footwear. Although unquantified, good visual agreement to the HSV footage was observed but significant discrepancies were found between the model and experimental GRF and COP readings (9% and 61% of model readings outside of the mean experimental reading ± 2 standard deviations, respectively). Model output was also found to be highly sensitive to input kinematics with a 120% increase in maximum GRF observed when translating the force platform 2 mm vertically. While representing an alternative approach to existing dynamic finite element footstrike models, loading highly representative of an experimental trial was not found to be achievable when employing exclusively kinematic boundary conditions. This significantly limits the usefulness of employing such an approach in the footwear development process.

A bootstrap procedure was used to determine the statistical precision of estimates of mean and peak spinal loads during lifting as function of the numbers of subjects and measurements per subject included in a biomechanical study. Data were derived from an experiment in which 10 subjects performed 360 lifting trials each. The maximum values per lift of the lumbar flexion angle, L5S1 sagittal plane moment, and L5S1 compression force were determined. From the data set thus compiled, 3000 samples were randomly drawn for each combination of number of subjects and number of measurements considered. The coefficients of variation of mean and peak (defined as mean plus 2 standard deviations) spinal loads across these samples were calculated. The coefficients of variation of the means of the three parameters of spinal load decreased as a linear function of the number of subjects to a power of about -0.48 and number of measurements to a power of about -0.06, while the corresponding powers for peak loads were about -0.44 and -0.11. © 2002 Elsevier Science Ltd. All rights reserved.

BackgroundThe psychometric properties of an online test are not necessarily identical to its paper and pencil original. The aim of this study is to test whether the factor structure of the Community Assessment of Psychic Experiences (CAPE) is measurement invariant with respect to online vs. paper and pencil assessment.MethodThe factor structure of CAPE items assessed by paper and pencil (N = 796) was compared with the factor structure of CAPE items assessed by the Internet (N = 21,590) using formal tests for Measurement Invariance (MI). The effect size was calculated by estimating the Signed Item Difference in the Sample (SIDS) index and the Signed Test Difference in the Sample (STDS) for a hypothetical subject who scores 2 standard deviations above average on the latent dimensions.ResultsThe more restricted Metric Invariance model showed a significantly worse fit compared to the less restricted Configural Invariance model (χ(2)(23) = 152.75, pConclusionsOur findings did not support measurement invariance with respect to assessment method. Because of the small effect sizes, the measurement differences between the online assessed CAPE and its paper and pencil original can be neglected without major consequences for research purposes. However, a person with a high vulnerability for psychotic symptoms would score 4.80 points lower on the total scale if the CAPE is assessed online compared to paper and pencil assessment. Therefore, for clinical purposes, one should be cautious with online assessment of the CAPE.

I summarize the observables constraining the B_s-B_s-bar mixing complex and present a new calculation of the element Gamma_{12}^s of the decay matrix. Gamma_{12}^s enters the prediction of the width difference Delta Gamma_s, for which we obtain Delta Gamma_s^SM = 0.088 +/- 0.017 ps^(-1), if no new physics enters B_s-B_s-bar mixing. Applying our formulae to Tevatron data we find a deviation of the B_s-B_s-bar mixing phase phi_s from its Standard Model value by 2 standard deviations. I stress that present data do not give any information on the sign of Delta Gamma_s., Talk at "CTP Symposium On Supersymmetry At LHC: Theoretical And Experimental Prospectives", 11-14 Mar 2007, Cairo, Egypt

SUMMARY Purpose A continuous systematic review of all combinations of drugs and suspected adverse reactions (ADRs) reported to a spontaneous reporting system, is necessary to optimize signal detection. To focus attention of human reviewers, quantitative procedures can be used to sift data in different ways. In various centres, different measures are used to quantify the extent to which an ADR is reported disproportionally to a certain drug compared to the generality of the database. The objective of this study is to examine the level of concordance of the various estimates to the measure used by the WHO Collaborating Centre for International ADR monitoring, the information component (IC), when applied to the dataset of the Netherlands Pharmacovigilance Foundation Lareb. Methods The Reporting Odds Ratio � 1.96 standard errors (SE), proportional reporting ratio � 1.96 SE, Yule’s Q � 1.96 SE, the Poisson probability and Chi-square test of all 17 330 combinations were compared with the IC minus 2 standard deviations. Additionally, the concordance of the various tests, in respect to the number of reports per combination, was examined. Results In general, sensitivity was high in respect to the reference measure when a combination of point- and precision estimate was used. The concordance increased dramatically when the number of reports per combination increased. Conclusion This study shows that the different measures used are broadly comparable when four or more cases per combination have been collected. Copyright # 2002 John Wiley & Sons, Ltd.

To evaluate the usefulness of aesthesiometric threshold testing in the quantitative assessment of peripheral sensorineural disorders occurring in the hand-arm vibration syndrome, two point discrimination (TPD) and depth sense perception (DSP) thresholds were measured by means of two aesthesiometers in the fingertips of 65 forestry workers exposed to chain saw vibration and 91 healthy males unexposed to local vibration or neurotoxic chemicals. Among the healthy subjects, divided into three age groups, there was no difference in the mean values of TPD and DSP thresholds. Assuming 1.28 or 2 standard deviations above the mean to be the upper limits of normality, in the present study the threshold values for TPD were 2.5 and 3.13 mm, respectively. Using the same assumptions, the normal threshold values for DSP were 0.36 and 0.49 mm. Among the 65 chain saw operators the prevalence of peripheral sensory disturbances was 70.8%. On the basis of the aesthesiometric results obtained for the group of 46 chain sawyers affected with sensorineural symptoms and a control group of 46 manual workers, the specificity of the aesthesiometric testing method was found to range between 93.4 and 100%, while the sensitivity varied from 52.2 to 71.7%. In its predictive value aesthesiometry had a positive accuracy of 84.6–96.0% and a negative accuracy of 42.8–50.0%. Aesthesiometric testing was able to differentiate between normals and vibration workers with sensory disturbances on a group basis (P < 0.001), but due to the high rate of false negatives among vibration exposed patients, it was unsuitable to confirm objectively sensorineural symptoms on an individual basis. We conclude that aesthesiometry may be used in field surveys for epidemiological purposes to assess peripheral sensory disorders in exposed groups at risk.

A computer program has been developed to calculate parameters associated with cerebral blood flow as studied by scintiangiography. Slopes, integrals, arrival times, maximum counting rates and other quantities are calculated from time activity curves corresponding to designated regions of interest: carotid arteries, middle and anterior cerebral arteries and the peripheral portions of the cerebral hemispheres. Analysis of 210 normal studies revealed good correlation (coefficient of .70) for both the arterial transit time and the normalized uptake slope (slope/CMAX) with patient age. In this study, normal ranges of time differences and ratios between contralateral regions of interest were calculated. A comparison made with a group of 50 CVA patients showed that 94% of them had at least one parameter where the left/right ratio and/or time difference were beyond 2 standard deviations of the normal mean.