Design and analysis of three-arm trials with negative binomially distributed endpoints.

PubMed

Mütze, Tobias; Munk, Axel; Friede, Tim

2016-02-20

A three-arm clinical trial design with an experimental treatment, an active control, and a placebo control, commonly referred to as the gold standard design, enables testing of non-inferiority or superiority of the experimental treatment compared with the active control. In this paper, we propose methods for designing and analyzing three-arm trials with negative binomially distributed endpoints. In particular, we develop a Wald-type test with a restricted maximum-likelihood variance estimator for testing non-inferiority or superiority. For this test, sample size and power formulas as well as optimal sample size allocations will be derived. The performance of the proposed test will be assessed in an extensive simulation study with regard to type I error rate, power, sample size, and sample size allocation. For the purpose of comparison, Wald-type statistics with a sample variance estimator and an unrestricted maximum-likelihood estimator are included in the simulation study. We found that the proposed Wald-type test with a restricted variance estimator performed well across the considered scenarios and is therefore recommended for application in clinical trials. The methods proposed are motivated and illustrated by a recent clinical trial in multiple sclerosis. The R package ThreeArmedTrials, which implements the methods discussed in this paper, is available on CRAN. Copyright © 2015 John Wiley & Sons, Ltd.

Does Bacopa monnieri improve memory performance in older persons? Results of a randomized, placebo-controlled, double-blind trial.

PubMed

Morgan, Annette; Stevens, John

2010-07-01

The objective of this study was to investigate the effectiveness of Bacopa monnieri Linn. for improvement of memory performance in healthy older persons. This was a randomized, double-blind, placebo-controlled trial. The trial took place in Lismore, NSW, Australia between February and July 2005. Ninety-eight (98) healthy participants over 55 years of age were recruited from the general population. Participants were randomized to receive an extract of Bacopa monnieri called BacoMind(TM) (Natural Remedies Pvt. Ltd.), 300 mg/day, or an identical placebo. Following screening, neuropsychologic and subjective memory assessments were performed at baseline and at 12 weeks. Audioverbal and visual memory performance were measured by the Rey Auditory Verbal Learning Test (AVLT), the Rey-Osterrieth Complex Figure Test (CFT), and the Reitan Trail Making Test (TMT). Subjective memory performance was measured by the Memory Complaint Questionnaire (MAC-Q). One hundred and thirty-six (136) subjects volunteered; 103 met entry criteria, 98 commenced, and 81 completed the trial. Bacopa significantly improved verbal learning, memory acquisition, and delayed recall as measured by the AVLT: trial a4 (p = 0.000), trial a5 (p = 0.016); trial a6 (p = 0.000); trial a7 (delayed recall) (p = 0.001); total learning (p = 0.011); and retroactive interference (p = 0.048). CFT, MAC-Q, and TMT scores improved but group differences were not significant. Bacopa versus placebo caused gastrointestinal tract (GIT) side-effects. Bacopa significantly improved memory acquisition and retention in healthy older Australians. This concurs with previous findings and traditional use. Bacopa caused GIT side-effects of increased stool frequency, abdominal cramps, and nausea.

RELIABILITY OF THE ONE REPETITION-MAXIMUM POWER CLEAN TEST IN ADOLESCENT ATHLETES

PubMed Central

Faigenbaum, Avery D.; McFarland, James E.; Herman, Robert; Naclerio, Fernando; Ratamess, Nicholas A.; Kang, Jie; Myer, Gregory D.

2013-01-01

Although the power clean test is routinely used to assess strength and power performance in adult athletes, the reliability of this measure in younger populations has not been examined. Therefore, the purpose of this study was to determine the reliability of the one repetition maximum (1 RM) power clean in adolescent athletes. Thirty-six male athletes (age 15.9 ± 1.1 yrs, body mass 79.1 ± 20.3 kg, height 175.1 ±7.4 cm) who had more than 1 year of training experience with weightlifting exercises performed a 1 RM power clean on two nonconsecutive days in the afternoon following standardized procedures. All test procedures were supervised by a senior level weightlifting coach and consisted of a systematic progression in test load until the maximum resistance that could be lifted for one repetition using proper exercise technique was determined. Data were analyzed using an intraclass correlation coefficient (ICC [2,k]), Pearson correlation coefficient (r), repeated measures ANOVA, Bland-Altman plot, and typical error analyses. Analysis of the data revealed that the test measures were highly reliable demonstrating a test-retest ICC of 0.98 (95% CI = 0.96–0.99). Testing also demonstrated a strong relationship between 1 RM measures on trial 1 and trial 2 (r=0.98, p<0.0001) with no significant difference in power clean performance between trials (70.6 ± 19.8 vs. 69.8 ± 19.8 kg). Bland Altman plots confirmed no systematic shift in 1 RM between trial 1 and trial 2. The typical error to be expected between 1 RM power clean trials is 2.9 kg and a change of at least 8.0 kg is indicated to determine a real change in lifting performance between tests in young lifters. No injuries occurred during the study period and the testing protocol was well-tolerated by all subjects. These findings indicate that 1 RM power clean testing has a high degree of reproducibility in trained male adolescent athletes when standardized testing procedures are followed and qualified instruction is present. PMID:22233786

Malaria Diagnostics in Clinical Trials

PubMed Central

Murphy, Sean C.; Shott, Joseph P.; Parikh, Sunil; Etter, Paige; Prescott, William R.; Stewart, V. Ann

2013-01-01

Malaria diagnostics are widely used in epidemiologic studies to investigate natural history of disease and in drug and vaccine clinical trials to exclude participants or evaluate efficacy. The Malaria Laboratory Network (MLN), managed by the Office of HIV/AIDS Network Coordination, is an international working group with mutual interests in malaria disease and diagnosis and in human immunodeficiency virus/acquired immunodeficiency syndrome clinical trials. The MLN considered and studied the wide array of available malaria diagnostic tests for their suitability for screening trial participants and/or obtaining study endpoints for malaria clinical trials, including studies of HIV/malaria co-infection and other malaria natural history studies. The MLN provides recommendations on microscopy, rapid diagnostic tests, serologic tests, and molecular assays to guide selection of the most appropriate test(s) for specific research objectives. In addition, this report provides recommendations regarding quality management to ensure reproducibility across sites in clinical trials. Performance evaluation, quality control, and external quality assessment are critical processes that must be implemented in all clinical trials using malaria tests. PMID:24062484

Reveal Salmonella 2.0 test for detection of Salmonella spp. in foods and environmental samples. Performance Tested Method 960801.

PubMed

Hoerner, Rebecca; Feldpausch, Jill; Gray, R Lucas; Curry, Stephanie; Islam, Zahidul; Goldy, Tim; Klein, Frank; Tadese, Theodros; Rice, Jennifer; Mozola, Mark

2011-01-01

Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A-E in a variety of food and environmental samples. A Performance Tested Method validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A-E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae representing 14 genera, 32 were negative when tested with Reveal following nonselective enrichment, and the remaining strain was found to be substantially inhibited by the enrichment media used with the Reveal method. Results of ruggedness testing showed that the Reveal test produces accurate results even with substantial deviation in sample volume or device development time.

The Effects of Test Trial and Processing Level on Immediate and Delayed Retention.

PubMed

Chang, Sau Hou

2017-03-01

The purpose of the present study was to investigate the effects of test trial and processing level on immediate and delayed retention. A 2 × 2 × 2 mixed ANOVAs was used with two between-subject factors of test trial (single test, repeated test) and processing level (shallow, deep), and one within-subject factor of final recall (immediate, delayed). Seventy-six college students were randomly assigned first to the single test (studied the stimulus words three times and took one free-recall test) and the repeated test trials (studied the stimulus words once and took three consecutive free-recall tests), and then to the shallow processing level (asked whether each stimulus word was presented in capital letter or in small letter) and the deep processing level (whether each stimulus word belonged to a particular category) to study forty stimulus words. The immediate test was administered five minutes after the trials, whereas the delayed test was administered one week later. Results showed that single test trial recalled more words than repeated test trial in immediate final free-recall test, participants in deep processing performed better than those in shallow processing in both immediate and delayed retention. However, the dominance of single test trial and deep processing did not happen in delayed retention. Additional study trials did not further enhance the delayed retention of words encoded in deep processing, but did enhance the delayed retention of words encoded in shallow processing.

The Effects of Test Trial and Processing Level on Immediate and Delayed Retention

PubMed Central

Chang, Sau Hou

2017-01-01

The purpose of the present study was to investigate the effects of test trial and processing level on immediate and delayed retention. A 2 × 2 × 2 mixed ANOVAs was used with two between-subject factors of test trial (single test, repeated test) and processing level (shallow, deep), and one within-subject factor of final recall (immediate, delayed). Seventy-six college students were randomly assigned first to the single test (studied the stimulus words three times and took one free-recall test) and the repeated test trials (studied the stimulus words once and took three consecutive free-recall tests), and then to the shallow processing level (asked whether each stimulus word was presented in capital letter or in small letter) and the deep processing level (whether each stimulus word belonged to a particular category) to study forty stimulus words. The immediate test was administered five minutes after the trials, whereas the delayed test was administered one week later. Results showed that single test trial recalled more words than repeated test trial in immediate final free-recall test, participants in deep processing performed better than those in shallow processing in both immediate and delayed retention. However, the dominance of single test trial and deep processing did not happen in delayed retention. Additional study trials did not further enhance the delayed retention of words encoded in deep processing, but did enhance the delayed retention of words encoded in shallow processing. PMID:28344679

Memory systems in the rat: effects of reward probability, context, and congruency between working and reference memory.

PubMed

Roberts, William A; Guitar, Nicole A; Marsh, Heidi L; MacDonald, Hayden

2016-05-01

The interaction of working and reference memory was studied in rats on an eight-arm radial maze. In two experiments, rats were trained to perform working memory and reference memory tasks. On working memory trials, they were allowed to enter four randomly chosen arms for reward in a study phase and then had to choose the unentered arms for reward in a test phase. On reference memory trials, they had to learn to visit the same four arms on the maze on every trial for reward. Retention was tested on working memory trials in which the interval between the study and test phase was 15 s, 15 min, or 30 min. At each retention interval, tests were performed in which the correct WM arms were either congruent or incongruent with the correct RM arms. Both experiments showed that congruency interacted with retention interval, yielding more forgetting at 30 min on incongruent trials than on congruent trials. The effect of reference memory strength on the congruency effect was examined in Experiment 1, and the effect of associating different contexts with working and reference memory on the congruency effect was studied in Experiment 2.

Effects of 4 weeks of creatine supplementation in junior swimmers on freestyle sprint and swim bench performance.

PubMed

Dawson, Brian; Vladich, Todd; Blanksby, Brian A

2002-11-01

To determine whether 4 weeks of oral creatine (Cr) supplementation could enhance single freestyle sprint and swim bench performance in experienced competitive junior swimmers, 10 young men and 10 young women (x age = 16.4 +/- 1.8 years) participated in a 27-day supplementation period and pre- and posttesting sessions. In session 1 (presupplementation testing), subjects swam one 50-m freestyle and then (after approximately 5 minutes of active recovery) one 100-m freestyle at maximum speed. Blood lactate was measured before and 1 minute after each swim trial. Forty-eight hours later, height, mass, and the sum of 6 skinfolds were recorded, and a Biokinetic Swim Bench total work output test (2 x 30-second trials, with a 10-minute passive recovery in between) was undertaken. After the pretests were completed, participants were divided into 2 groups (n = 10, Cr; and n = 10, placebo) by means of matched pairs on the basis of gender and 50-m swim times. A Cr loading phase of 20 g x d(-1) for 5 days was then instituted, followed by a maintenance phase of 5 g x d(-1) for 22 days. Postsupplementation testing replicated the presupplementation tests. Four weeks of Cr supplementation did not influence single sprint performance in the pool or body mass and composition. However, 30-second swim bench total work scores for trial 1 and trial 2 increased after Cr (p < 0.05) but not placebo ingestion. Postexercise blood lactate values were not different after supplementation for the 50- and 100-m sprint trials either within or between groups. It was concluded that 4 weeks of Cr supplementation did not significantly improve single sprint performance in competitive junior swimmers, but it did enhance swim bench test performance.

A study to assess whether fixed-width beam walking provides sufficient challenge to assess balance ability across lower limb prosthesis users.

PubMed

Sawers, Andrew; Hafner, Brian J

2018-04-01

To evaluate the feasibility of fixed-width beam walking for assessing balance in lower limb prosthesis users. Cross-sectional. Laboratory. Lower limb prosthesis users. Participants attempted 10 walking trials on three fixed-width beams (18.6, 8.60, and 4.01 wide; 5.5 m long; 3.8 cm high). Beam-walking performance was quantified using the distance walked to balance failure. Heuristic rules applied to each participant's beam-walking distance to classify each beam as "too easy," "too hard," or "appropriately challenging" and determine whether any single beam provided an appropriate challenge to all participants. The number of trials needed to achieve stable beam-walking performance was quantified for appropriately challenging beams by identifying the last inflection point in the slope of each participant's trial-by-trial cumulative performance record. In all, 30 unilateral lower limb prosthesis users participated in the study. Each of the fixed-width beams was either too easy or too hard for at least 33% of the sample. Thus, no single beam was appropriately challenging for all participants. Beam-walking performance was stable by trial 8 for all participants and by trial 6 for 90% of participants. There was no significant difference in the number of trials needed to achieve stable performance among beams ( P = 0.74). Results suggest that a clinical beam-walking test would require multiple beams to evaluate balance across a range of lower limb prosthesis users, emphasizing the need for adaptive or progressively challenging balance tests. While the administrative burden of a multiple-beam balance test may limit clinical feasibility, alternatives to ease this administrative burden are proposed.

Optical ensemble analysis of intraocular lens performance through a simulated clinical trial with ZEMAX.

PubMed

Zhao, Huawei

2009-01-01

A ZEMAX model was constructed to simulate a clinical trial of intraocular lenses (IOLs) based on a clinically oriented Monte Carlo ensemble analysis using postoperative ocular parameters. The purpose of this model is to test the feasibility of streamlining and optimizing both the design process and the clinical testing of IOLs. This optical ensemble analysis (OEA) is also validated. Simulated pseudophakic eyes were generated by using the tolerancing and programming features of ZEMAX optical design software. OEA methodology was verified by demonstrating that the results of clinical performance simulations were consistent with previously published clinical performance data using the same types of IOLs. From these results we conclude that the OEA method can objectively simulate the potential clinical trial performance of IOLs.

Route learning in amnesia: a comparison of trial-and-error and errorless learning in patients with the Korsakoff syndrome.

PubMed

Kessels, Roy P C; van Loon, Eke; Wester, Arie J

2007-10-01

To examine the errorless learning approach using a procedural memory task (i.e. learning of actual routes) in patients with amnesia, as compared to trial-and-error learning. Counterbalanced self-controlled cases series. Psychiatric hospital (Korsakoff clinic). A convenience sample of 10 patients with the Korsakoff amnestic syndrome. All patients learned a route in four sessions on separate days using an errorless approach and a different route using trial-and-error. Error rate was scored during route learning and standard neuro-psychological tests were administered (i.e. subtest route recall of the Rivermead Behavioural Memory Test (RBMT) and the Dutch version of the California Verbal Learning Test (VLGT)). A significant learning effect was found in the trial-and-error condition over consecutive sessions (P = 0.006), but no performance difference was found between errorless and trial-and-error learning of the routes. VLGT performance was significantly correlated with a trial-and-error advantage (P < 0.05); no significant correlation was found between the RBMT subtest and the learning conditions. Errorless learning was no more successful than trial-and-error learning of a procedural spatial task in patients with the Korsakoff syndrome (severe amnesia).

Testing non-inferiority of a new treatment in three-arm clinical trials with binary endpoints.

PubMed

Tang, Nian-Sheng; Yu, Bin; Tang, Man-Lai

2014-12-18

A two-arm non-inferiority trial without a placebo is usually adopted to demonstrate that an experimental treatment is not worse than a reference treatment by a small pre-specified non-inferiority margin due to ethical concerns. Selection of the non-inferiority margin and establishment of assay sensitivity are two major issues in the design, analysis and interpretation for two-arm non-inferiority trials. Alternatively, a three-arm non-inferiority clinical trial including a placebo is usually conducted to assess the assay sensitivity and internal validity of a trial. Recently, some large-sample approaches have been developed to assess the non-inferiority of a new treatment based on the three-arm trial design. However, these methods behave badly with small sample sizes in the three arms. This manuscript aims to develop some reliable small-sample methods to test three-arm non-inferiority. Saddlepoint approximation, exact and approximate unconditional, and bootstrap-resampling methods are developed to calculate p-values of the Wald-type, score and likelihood ratio tests. Simulation studies are conducted to evaluate their performance in terms of type I error rate and power. Our empirical results show that the saddlepoint approximation method generally behaves better than the asymptotic method based on the Wald-type test statistic. For small sample sizes, approximate unconditional and bootstrap-resampling methods based on the score test statistic perform better in the sense that their corresponding type I error rates are generally closer to the prespecified nominal level than those of other test procedures. Both approximate unconditional and bootstrap-resampling test procedures based on the score test statistic are generally recommended for three-arm non-inferiority trials with binary outcomes.

Effect of respiratory muscle training on exercise performance in healthy individuals: a systematic review and meta-analysis.

PubMed

Illi, Sabine K; Held, Ulrike; Frank, Irène; Spengler, Christina M

2012-08-01

Two distinct types of specific respiratory muscle training (RMT), i.e. respiratory muscle strength (resistive/threshold) and endurance (hyperpnoea) training, have been established to improve the endurance performance of healthy individuals. We performed a systematic review and meta-analysis in order to determine the factors that affect the change in endurance performance after RMT in healthy subjects. A computerized search was performed without language restriction in MEDLINE, EMBASE and CINAHL and references of original studies and reviews were searched for further relevant studies. RMT studies with healthy individuals assessing changes in endurance exercise performance by maximal tests (constant load, time trial, intermittent incremental, conventional [non-intermittent] incremental) were screened and abstracted by two independent investigators. A multiple linear regression model was used to identify effects of subjects' fitness, type of RMT (inspiratory or combined inspiratory/expiratory muscle strength training, respiratory muscle endurance training), type of exercise test, test duration and type of sport (rowing, running, swimming, cycling) on changes in performance after RMT. In addition, a meta-analysis was performed to determine the effect of RMT on endurance performance in those studies providing the necessary data. The multiple linear regression analysis including 46 original studies revealed that less fit subjects benefit more from RMT than highly trained athletes (6.0% per 10 mL · kg⁻¹ · min⁻¹ decrease in maximal oxygen uptake, 95% confidence interval [CI] 1.8, 10.2%; p = 0.005) and that improvements do not differ significantly between inspiratory muscle strength and respiratory muscle endurance training (p = 0.208), while combined inspiratory and expiratory muscle strength training seems to be superior in improving performance, although based on only 6 studies (+12.8% compared with inspiratory muscle strength training, 95% CI 3.6, 22.0%; p = 0.006). Furthermore, constant load tests (+16%, 95% CI 10.2, 22.9%) and intermittent incremental tests (+18.5%, 95% CI 10.8, 26.3%) detect changes in endurance performance better than conventional incremental tests (both p < 0.001) with no difference between time trials and conventional incremental tests (p = 0.286). With increasing test duration, improvements in performance are greater (+0.4% per minute test duration, 95% CI 0.1, 0.6%; p = 0.011) and the type of sport does not influence the magnitude of improvements (all p > 0.05). The meta-analysis, performed on eight controlled trials revealed a significant improvement in performance after RMT, which was detected by constant load tests, time trials and intermittent incremental tests, but not by conventional incremental tests. RMT improves endurance exercise performance in healthy individuals with greater improvements in less fit individuals and in sports of longer durations. The two most common types of RMT (inspiratory muscle strength and respiratory muscle endurance training) do not differ significantly in their effect, while combined inspiratory/expiratory strength training might be superior. Improvements are similar between different types of sports. Changes in performance can be detected by constant load tests, time trials and intermittent incremental tests only. Thus, all types of RMT can be used to improve exercise performance in healthy subjects but care must be taken regarding the test used to investigate the improvements.

The influence of tyre characteristics on measures of rolling performance during cross-country mountain biking.

PubMed

Macdermid, Paul William; Fink, Philip W; Stannard, Stephen R

2015-01-01

This investigation sets out to assess the effect of five different models of mountain bike tyre on rolling performance over hard-pack mud. Independent characteristics included total weight, volume, tread surface area and tread depth. One male cyclist performed multiple (30) trials of a deceleration field test to assess reliability. Further tests performed on a separate occasion included multiple (15) trials of the deceleration test and six fixed power output hill climb tests for each tyre. The deceleration test proved to be reliable as a means of assessing rolling performance via differences in initial and final speed (coefficient of variation (CV) = 4.52%). Overall differences between tyre performance for both deceleration test (P = 0.014) and hill climb (P = 0.032) were found, enabling significant (P < 0.0001 and P = 0.049) models to be generated, allowing tyre performance prediction based on tyre characteristics. The ideal tyre for rolling and climbing performance on hard-pack surfaces would be to decrease tyre weight by way of reductions in tread surface area and tread depth while keeping volume high.

Judgments of Learning are Influenced by Multiple Cues In Addition to Memory for Past Test Accuracy.

PubMed

Hertzog, Christopher; Hines, Jarrod C; Touron, Dayna R

When people try to learn new information (e.g., in a school setting), they often have multiple opportunities to study the material. One of the most important things to know is whether people adjust their study behavior on the basis of past success so as to increase their overall level of learning (for example, by emphasizing information they have not yet learned). Monitoring their learning is a key part of being able to make those kinds of adjustments. We used a recognition memory task to replicate prior research showing that memory for past test outcomes influences later monitoring, as measured by judgments of learning (JOLs; confidence that the material has been learned), but also to show that subjective confidence in whether the test answer and the amount of time taken to restudy the items also have independent effects on JOLs. We also show that there are individual differences in the effects of test accuracy and test confidence on JOLs, showing that some but not all people use past test experiences to guide monitoring of their new learning. Monitoring learning is therefore a complex process of considering multiple cues, and some people attend to those cues more effectively than others. Improving the quality of monitoring performance and learning could lead to better study behaviors and better learning. An individual's memory of past test performance (MPT) is often cited as the primary cue for judgments of learning (JOLs) following test experience during multi-trial learning tasks (Finn & Metcalfe, 2007; 2008). We used an associative recognition task to evaluate MPT-related phenomena, because performance monitoring, as measured by recognition test confidence judgments (CJs), is fallible and varies in accuracy across persons. The current study used multilevel regression models to show the simultaneous and independent influences of multiple cues on Trial 2 JOLs, in addition to performance accuracy (the typical measure of MPT in cued-recall experiments). These cues include recognition CJs, perceived recognition fluency, and Trial 2 study time allocation (an index of reprocessing fluency). Our results expand the scope of MPT-related phenomena in recognition memory testing to show independent effects of recognition test accuracy and CJs on second-trial JOLs, while also demonstrating individual differences in the effects of these cues on JOLs (as manifested in significant random effects for those regression effects in the model). The effect of study time on second-trial JOLs controlling on other variables, including Trial 1 recognition memory accuracy, also demonstrates that second-trial encoding behavior influence JOLs in addition to MPT.

Trial 1 versus Trial 2 of the Test of Memory Malingering: Evaluating accuracy without a "gold standard".

PubMed

Mossman, Douglas; Wygant, Dustin B; Gervais, Roger O; Hart, Kathleen J

2018-01-01

This study examines the accuracy of the Test of Memory Malingering (TOMM), a frequently administered measure for evaluating effort during neurocognitive testing. In the last few years, several authors have suggested that the initial recognition trial of the TOMM (Trial 1) might be a more useful index for detecting feigned or exaggerated impairment than Trial 2, which is the source for inference recommended by the original instruction manual (Tombaugh, 1996). We used latent class modeling (LCM) implemented in a Bayesian framework to evaluate archival Trial 1 and Trial 2 data collected from 1,198 adults who had undergone outpatient forensic evaluations. All subjects were tested with 2 other performance validity tests (the Word Memory Test and the Computerized Assessment of Response Bias), and for 70% of the subjects, data from the California Verbal Learning Test-Second Edition Forced Choice trial were also available. Our results suggest that not even a perfect score on Trial 1 or Trial 2 justifies saying that an evaluee is definitely responding genuinely, although such scores imply a lower-than-base-rate probability of feigning. If one uses a Trial 2 cut-off higher than the manual's recommendation, Trial 2 does better than Trial 1 at identifying individuals who are almost certainly feigning while maintaining a negligible false positive rate. Using scores from both trials, one can identify a group of definitely feigning and very likely feigning subjects who comprise about 2 thirds of all feigners; only 1% of the members of this group would not be feigning. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Not all performance validity tests are created equal: The role of recollection and familiarity in the Test of Memory Malingering and Word Memory Test.

PubMed

Eglit, Graham M L; Lynch, Julie K; McCaffrey, Robert J

2017-03-01

The Test of Memory Malingering (TOMM) and the Word Memory Test (WMT) are both performance validity tests (PVTs) that use a two-alternative forced-choice (2AFC) recognition memory format. Several studies have reported that these tests are susceptible to cognitive impairment and that the WMT is more susceptible than the TOMM. The current study explored components of recognition memory (i.e., conscious recollection and familiarity) underlying the TOMM and WMT to identify factors that make them susceptible and resilient to cognitive impairment. Fifty-four nonclinical undergraduate research participants were administered the TOMM and WMT while providing introspective judgments about their recognition memory using the remember/know/guess procedure. In addition, half of participants were administered dual-task interference, a manipulation intended to reduce recollection, during these tests, while the other half completed these tests without interference. Standard cutoffs on the TOMM and WMT were explored, as well as alternative cutoffs based on TOMM Trial 1 scores. The WMT was more impacted by dual-task interference than standard TOMM cutoff trials, while alternative TOMM cutoff trials were equally impacted by dual-task interference relative to the WMT. Dual-task interference reduced recollection on these tests, but spared familiarity. Standard TOMM trials and the WMT were relatively comparable on levels of recollection, but familiarity contributed more to the TOMM than to the WMT. Alternative TOMM trials possessed lower familiarity and recollection than standard TOMM trials and lower recollection than the WMT. Reduced recollection places examinees at risk of failing the TOMM and WMT, while familiarity contributes to the relative resilience of the standard TOMM. Future development of 2AFC recognition memory PVTs should attempt to maximize the contribution of familiarity to their completion.

Dopamine/noradrenaline reuptake inhibition in women improves endurance exercise performance in the heat.

PubMed

Cordery, P; Peirce, N; Maughan, R J; Watson, P

2017-11-01

Catecholamine reuptake inhibition improves the performance of male volunteers exercising in warm conditions, but sex differences in thermoregulation, circulating hormones, and central neurotransmission may alter this response. With local ethics committee approval, nine physically active women (mean ± SD age 21 ± 2 years; height 1.68 ± 0.08 m; body mass 64.1 ± 6.0 kg; VO 2peak 51 ± 7 mL/kg/min) were recruited to examine the effect of pre-exercise administration of Bupropion (BUP; 4 × 150 mg) on prolonged exercise performance in a warm environment. Participants completed a VO 2peak test, two familiarization trials, and two randomized, double-blind experimental trials. All trials took place during the first 10 days of the follicular phase of the menstrual cycle. Participants cycled for 1 h at 60% VO 2peak followed by a 30-min performance test. Total work done was greater during the BUP trial (291 ± 48 kJ) than the placebo trial (269 ± 46 kJ, P = 0.042, d = 0.497). At the end of the performance test, core temperature was higher on the BUP trial (39.5 ± 0.4 °C) than on the placebo trial (39.2 ± 0.6 °C, P = 0.021; d = 0.588), as was heart rate (185 ± 9 vs 179 ± 13, P = 0.043; d = 0.537). The results indicate that during the follicular phase of the menstrual cycle, an acute dosing protocol of BUP can improve self-regulated performance in warm conditions. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Static Stretching Alters Neuromuscular Function and Pacing Strategy, but Not Performance during a 3-Km Running Time-Trial

PubMed Central

Damasceno, Mayara V.; Duarte, Marcos; Pasqua, Leonardo A.; Lima-Silva, Adriano E.; MacIntosh, Brian R.; Bertuzzi, Rômulo

2014-01-01

Purpose Previous studies report that static stretching (SS) impairs running economy. Assuming that pacing strategy relies on rate of energy use, this study aimed to determine whether SS would modify pacing strategy and performance in a 3-km running time-trial. Methods Eleven recreational distance runners performed a) a constant-speed running test without previous SS and a maximal incremental treadmill test; b) an anthropometric assessment and a constant-speed running test with previous SS; c) a 3-km time-trial familiarization on an outdoor 400-m track; d and e) two 3-km time-trials, one with SS (experimental situation) and another without (control situation) previous static stretching. The order of the sessions d and e were randomized in a counterbalanced fashion. Sit-and-reach and drop jump tests were performed before the 3-km running time-trial in the control situation and before and after stretching exercises in the SS. Running economy, stride parameters, and electromyographic activity (EMG) of vastus medialis (VM), biceps femoris (BF) and gastrocnemius medialis (GA) were measured during the constant-speed tests. Results The overall running time did not change with condition (SS 11:35±00:31 s; control 11:28±00:41 s, p = 0.304), but the first 100 m was completed at a significantly lower velocity after SS. Surprisingly, SS did not modify the running economy, but the iEMG for the BF (+22.6%, p = 0.031), stride duration (+2.1%, p = 0.053) and range of motion (+11.1%, p = 0.0001) were significantly modified. Drop jump height decreased following SS (−9.2%, p = 0.001). Conclusion Static stretch impaired neuromuscular function, resulting in a slow start during a 3-km running time-trial, thus demonstrating the fundamental role of the neuromuscular system in the self-selected speed during the initial phase of the race. PMID:24905918

The computer-based Symbol Digit Modalities Test: establishing age-expected performance in healthy controls and evaluation of pediatric MS patients.

PubMed

Bigi, Sandra; Marrie, R A; Till, C; Yeh, E A; Akbar, N; Feinstein, A; Banwell, B L

2017-04-01

Decreased information processing speed (IPS) is frequently reported in pediatric multiple sclerosis (MS) patients. The computerized version of the Symbol Digit Modalities Test (c-SDMT) measures IPS over eight consecutive trials per session and additionally captures changes in performance within the session. Here, we establish normative c-SDMT performance and test-retest reliability in healthy children (HC) and explore differences in the overall c-SDMT-performance between HC and MS patients. This cross-sectional study included 478 HC (237 female, 49.5%) divided into five age groups (2 years each), and 27 MS patients (22 female, 81.5%) aged 8-18 years. The average time to complete the c-SDMT increased with age (|r| 0.70, 95% CI -0.74, -0.64). Test-retest reliability was high (ICC = 0.91) in HC. The total time to complete the c-SDMT did not differ between children with MS and sex- and age- matched HC (p = 0.23). However, MS patients were less likely to show faster performance across all the successive eight trials compared to HC (p = 0.0001). Healthy children demonstrate faster IPS with increasing age, as well as during successive trials of the c-SDMT. The inability of pediatric MS patients to maintain the increase in processing speed over successive trials suggests a reduced capacity for procedural learning, possibly resulting from cognitive fatigue.

Joint Acoustic Propagation Experiment (JAPE)

NASA Technical Reports Server (NTRS)

Carnes, Benny L.; Olsen, Robert O.; Kennedy, Bruce W.

1993-01-01

The Joint Acoustic Propagation Experiment (JAPE), performed under the auspices of NATO and the Acoustics Working Group, was conducted at White Sands Missile Range, New Mexico, USA, during the period 11-28 Jul. 1991. JAPE consisted of 220 trials using various acoustic sources including speakers, propane cannon, various types of military vehicles, helicopters, a 155mm howitzer, and static high explosives. Of primary importance to the performance of these tests was the intensive characterization of the atmosphere before and during the trials. Because of the wide range of interests on the part of the participants, JAPE was organized in such a manner to provide a broad cross section of test configurations. These included short and long range propagation from fixed and moving vehicles, terrain masking, and vehicle detection. A number of independent trials were also performed by individual participating agencies using the assets available during JAPE. These tests, while not documented in this report, provided substantial and important data to those groups. Perhaps the most significant feature of JAPE is the establishment of a permanent data base which can be used by not only the participants but by others interested in acoustics. A follow-on test was performed by NASA LaRC during the period 19-29 Aug. 1991 at the same location. These trials consisted of 59 overflights of supersonic aircraft in order to establish the relationship between atmospheric turbulence and the received sonic boom energy at the surface.

Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults

PubMed Central

Banducci, Sarah E.; Daugherty, Ana M.; Fanning, Jason; Awick, Elizabeth A.; Porter, Gwenndolyn C.; Burzynska, Agnieszka; Shen, Sa; Kramer, Arthur F.; McAuley, Edward

2017-01-01

Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60–79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial). PMID:28255557

Switch-Independent Task Representations in Frontal and Parietal Cortex.

PubMed

Loose, Lasse S; Wisniewski, David; Rusconi, Marco; Goschke, Thomas; Haynes, John-Dylan

2017-08-16

Alternating between two tasks is effortful and impairs performance. Previous fMRI studies have found increased activity in frontoparietal cortex when task switching is required. One possibility is that the additional control demands for switch trials are met by strengthening task representations in the human brain. Alternatively, on switch trials, the residual representation of the previous task might impede the buildup of a neural task representation. This would predict weaker task representations on switch trials, thus also explaining the performance costs. To test this, male and female participants were cued to perform one of two similar tasks, with the task being repeated or switched between successive trials. Multivoxel pattern analysis was used to test which regions encode the tasks and whether this encoding differs between switch and repeat trials. As expected, we found information about task representations in frontal and parietal cortex, but there was no difference in the decoding accuracy of task-related information between switch and repeat trials. Using cross-classification, we found that the frontoparietal cortex encodes tasks using a generalizable spatial pattern in switch and repeat trials. Therefore, task representations in frontal and parietal cortex are largely switch independent. We found no evidence that neural information about task representations in these regions can explain behavioral costs usually associated with task switching. SIGNIFICANCE STATEMENT Alternating between two tasks is effortful and slows down performance. One possible explanation is that the representations in the human brain need time to build up and are thus weaker on switch trials, explaining performance costs. Alternatively, task representations might even be enhanced to overcome the previous task. Here, we used a combination of fMRI and a brain classifier to test whether the additional control demands under switching conditions lead to an increased or decreased strength of task representations in frontoparietal brain regions. We found that task representations are not modulated significantly by switching processes and generalize across switching conditions. Therefore, task representations in the human brain cannot account for the performance costs associated with alternating between tasks. Copyright © 2017 the authors 0270-6474/17/378033-10$15.00/0.

Test-potentiated learning: three independent replications, a disconfirmed hypothesis, and an unexpected boundary condition.

PubMed

Wissman, Kathryn T; Rawson, Katherine A

2018-04-01

Arnold and McDermott [(2013). Test-potentiated learning: Distinguishing between direct and indirect effects of testing. Journal of Experimental Psychology: Learning, Memory, and Cognition, 39, 940-945] isolated the indirect effects of testing and concluded that encoding is enhanced to a greater extent following more versus fewer practice tests, referred to as test-potentiated learning. The current research provided further evidence for test-potentiated learning and evaluated the covert retrieval hypothesis as an alternative explanation for the observed effect. Learners initially studied foreign language word pairs and then completed either one or five practice tests before restudy occurred. Results of greatest interest concern performance on test trials following restudy for items that were not correctly recalled on the test trials that preceded restudy. Results replicate Arnold and McDermott (2013) by demonstrating that more versus fewer tests potentiate learning when trial time is limited. Results also provide strong evidence against the covert retrieval hypothesis concerning why the effect occurs (i.e., it does not reflect differential covert retrieval during pre-restudy trials). In addition, outcomes indicate that the magnitude of the test-potentiated learning effect decreases as trial length increases, revealing an unexpected boundary condition to test-potentiated learning.

Immediate Effects of Smoking on Cardiorespiratory Responses During Dynamic Exercise: Arm Vs. Leg Ergometry.

PubMed

Chen, Chien-Liang; Tang, Jing-Shia; Li, Ping-Chia; Chou, Pi-Ling

2015-01-01

This study compared the immediate effects of smoking on cardiorespiratory responses to dynamic arm and leg exercises. This randomized crossover study recruited 14 college students. Each participant underwent two sets of arm-cranking (AC) and leg-cycling (LC) exercise tests. The testing sequences of the control trial (participants refrained from smoking for 8 h before testing) and the experimental trial (participants smoked two cigarettes immediately before testing) were randomly chosen. We observed immediate changes in pulmonary function and heart rate variability after smoking and before the exercise test. The participants then underwent graded exercise tests of their arms and legs until reaching exhaustion. We compared the peak work achieved and time to exhaustion during the exercise tests with various cardiorespiratory indices [i.e., heart rate, oxygen consumption (VO2), minute ventilation (VE)]. The differences between the smoking and control trials were calculated using paired t-tests. For the exercise test periods, VO2, heart rate, and VE values were calculated at every 10% increment of the maximal effort time. The main effects of the time and trial, as well as their trial-by-time (4 × 10) interaction effects on the outcome measures, were investigated using repeated measure ANOVA with trend analysis. 5 min after smoking, the participants exhibited reduced forced vital capacities and forced expiratory volumes in the first second (P < 0.05), in addition to elevated resting heart rates (P < 0.001). The high-frequency, low-frequency, and the total power of the heart rate variability were also reduced (P < 0.05) at rest. For the exercise test periods, smoking reduced the time to exhaustion (P = 0.005) and the ventilatory threshold (P < 0.05) in the LC tests, whereas no significant effects were observed in the AC tests. A trend analysis revealed a significant trial-by-time interaction effect for heart rate, VO2, and VE during the graded exercise test (all P < 0.001). Lower VO2 and VE levels were exhibited in the exercise response of the smoking trial than in those of the control LC trials, whereas no discernable inter-trial difference was observed in the AC trials. Moreover, the differences in heart rate and VE response between the LC and AC exercises were significantly smaller after the participants smoked. This study verified that smoking significantly decreased performance and cardiorespiratory responses to leg exercises. However, the negative effects of smoking on arm exercise performance were not as pronounced.

Do Glucose and Caffeine Nasal Sprays Influence Exercise or Cognitive Performance?

PubMed

De Pauw, Kevin; Roelands, Bart; Van Cutsem, Jeroen; Decroix, Lieselot; Valente, Angelica; Taehee, Kim; Lettan, Robert B; Carrillo, Andres E; Meeusen, Romain

2017-10-01

Nasal spray (NAS) containing caffeine (CAF) or glucose (GLUC) activates sensory(motor) cortices. To investigate the influence of CAF or GLUC NAS on exercise and cognitive performance. Eleven male subjects (age 22 ± 2 y) performed a maximal cycle test and 2 familiarization and 3 experimental trials. Each trial included a 30-s Wingate test and a 30-min time-trial (TT) performance test interspersed by 15 min of rest. Before and after each exercise test a Stroop task was conducted. Placebo NAS with or without CAF or GLUC was provided before each exercise session and at each completed 25% of the TT. Exercise-performance, physiological, and cognitive measures were obtained. Magnitude-based inferences determined the likelihood that NAS solutions would be beneficial, trivial, or negative to exercise-performance measures based on the smallest worthwhile effect. Physiological and cognitive measures were analyzed using (non)parametric tests (P < .05). GLUC NAS substantially increased the average power output during the TT (very likely beneficial: 98%). No further worthwhile exercise-performance enhancements were found for both substances. In addition, no significant differences in physiological and cognitive measures were observed. In line with mouth rinsing, GLUC was shown to substantially enhance endurance performance, probably due to the activation of the olfactory pathway and/or extra-oral sweet-taste receptors. GLUC NAS enhances endurance performance, which indicates a novel administration route. The higher activity in sensory brain cortices probably elicited the ergogenic effect. However, no further physiological and cognitive changes occurred, indicating that higher doses of substrates might be required.

Effectiveness of the Comalli Stroop Test as a measure of negative response bias.

PubMed

Arentsen, Timothy J; Boone, Kyle Brauer; Lo, Tracy T Y; Goldberg, Hope E; Cottingham, Maria E; Victor, Tara L; Ziegler, Elizabeth; Zeller, Michelle A

2013-01-01

Practice guidelines recommend the use of multiple performance validity tests (PVTs) to detect noncredible performance during neuropsychological evaluations, and PVTs embedded in standard cognitive tests achieve this goal most efficiently. The present study examined the utility of the Comalli version of the Stroop Test as a measure of response bias in a large sample of "real world" noncredible patients (n = 129) as compared with credible neuropsychology clinic patients (n=233). The credible group performed significantly better than the noncredible group on all trials, but particularly on word-reading (Stroop A) and color-naming (Stroop B); cut-scores for Stroop A and Stroop B trials were associated with moderate sensitivity (49-53%) as compared to the low sensitivity found for the color interference trial (29%). Some types of diagnoses (including learning disability, severe traumatic brain injury, psychosis, and depression), very advanced age (⩾80), and lowered IQ were associated with increased rates of false positive identifications, suggesting the need for some adjustments to cut-offs in these subgroups. Despite some previous reports of an inverted Stroop effect (i.e., color-naming worse than color interference) in noncredible subjects, individual Stroop word reading and color naming trials were much more effective in identifying response bias.

Single-arm phase II trial design under parametric cure models.

PubMed

Wu, Jianrong

2015-01-01

The current practice of designing single-arm phase II survival trials is limited under the exponential model. Trial design under the exponential model may not be appropriate when a portion of patients are cured. There is no literature available for designing single-arm phase II trials under the parametric cure model. In this paper, a test statistic is proposed, and a sample size formula is derived for designing single-arm phase II trials under a class of parametric cure models. Extensive simulations showed that the proposed test and sample size formula perform very well under different scenarios. Copyright © 2015 John Wiley & Sons, Ltd.

Narrowing beam-walking is a clinically feasible approach for assessing balance ability in lower-limb prosthesis users.

PubMed

Sawers, Andrew; Hafner, Brian J

2018-05-08

Challenging clinical balance tests are needed to expose balance deficits in lower-limb prost-hesis users. This study examined whether narrowing beam-walking could overcome conceptual and practical limitations identified in fixed-width beam-walking. Cross-sectional. Unilateral lower-limb prosthesis users. Participants walked 10 times along a low, narrowing beam. Performance was quantified using the normalized distance walked. Heuristic rules were applied to determine whether the narrowing beam task was "too easy," "too hard," or "appropriately challenging" for each participant. Linear regression and Bland-Altman plots were used to determine whether combinations of the first 5 trials could predict participants' stable beam-walking performance. Forty unilateral lower-limb prosthesis users participated. Narrowing beam-walking was appropriately challenging for 98% of participants. Performance stabilized for 93% of participants within 5 trials, while 62% were stable across all trials. The mean of trials 3-5 accurately predicted stable performance. A clinical narrowing beam-walking test is likely to challenge a range of lower-limb prosthesis users, have minimal administrative burden, and exhibit no floor or ceiling effects. Narrowing beam-walking is therefore a clinically viable method to evaluate lower-limb prosthesis users' balance ability, but requires psychometric testing before it is used to assess fall risk.

Contralateral Delay Activity Tracks Fluctuations in Working Memory Performance.

PubMed

Adam, Kirsten C S; Robison, Matthew K; Vogel, Edward K

2018-01-08

Neural measures of working memory storage, such as the contralateral delay activity (CDA), are powerful tools in working memory research. CDA amplitude is sensitive to working memory load, reaches an asymptote at known behavioral limits, and predicts individual differences in capacity. An open question, however, is whether neural measures of load also track trial-by-trial fluctuations in performance. Here, we used a whole-report working memory task to test the relationship between CDA amplitude and working memory performance. If working memory failures are due to decision-based errors and retrieval failures, CDA amplitude would not differentiate good and poor performance trials when load is held constant. If failures arise during storage, then CDA amplitude should track both working memory load and trial-by-trial performance. As expected, CDA amplitude tracked load (Experiment 1), reaching an asymptote at three items. In Experiment 2, we tracked fluctuations in trial-by-trial performance. CDA amplitude was larger (more negative) for high-performance trials compared with low-performance trials, suggesting that fluctuations in performance were related to the successful storage of items. During working memory failures, participants oriented their attention to the correct side of the screen (lateralized P1) and maintained covert attention to the correct side during the delay period (lateralized alpha power suppression). Despite the preservation of attentional orienting, we found impairments consistent with an executive attention theory of individual differences in working memory capacity; fluctuations in executive control (indexed by pretrial frontal theta power) may be to blame for storage failures.

Modelling Simulation and Comparison of Refractory Corrosion at RHI's Technology Center

NASA Astrophysics Data System (ADS)

Gregurek, Dean; Ressler, Angelika; Franzkowiak, Anna; Spanring, Alfred

In order to determine the most suitable refractory products and improve the lining lifetime for the diverse furnaces used in the nonferrous metal industry, corrosion tests are performed at RHF's Technology Center. The practical facilities include the cup test, induction furnace, rotary kiln, and drip slag test described in this paper, which enable a comprehensive understanding of the chemo-thermal brick wear on a pilot scale. The corrosion trials are performed with actual slags generated during operations at a customer's plant. To determine the highest influencing wear parameter, every single test is combined with a detailed mineralogical investigation and thermochemical calculations performed using FactSage. Based on the results, tailored refractory solutions for the nonferrous metal industry can be provided in combination with trials conducted at the customer's site.

Implementation Considerations for Multisite Clinical Trials with Cognitive Neuroscience Tasks

PubMed Central

Keefe, Richard S. E.; Harvey, Philip D.

2008-01-01

Multisite clinical trials aimed at cognitive enhancement across various neuropsychiatric conditions have employed standard neuropsychological tests as outcome measures. While these tests have enjoyed wide clinical use and have proven reliable and predictive of functional disability, a number of implementation challenges have arisen when these tests are used in clinical trials. These issues are likely to be magnified in future studies when cognitive neuroscience (CN) procedures are explored in these trials, because in their current forms CN procedures are less standardized and more difficult to teach and monitor. For multisite trials, we anticipate that the most challenging issues will include assuring tester competence, monitoring tester performance, specific challenges with complex assessment methods, and having resources available for adequate monitoring of data quality. Suggestions for overcoming these implementation challenges are offered. PMID:18495645

Ball-Sport Endurance and Sprint Test (BEAST90): validity and reliability of a 90-minute soccer performance test.

PubMed

Williams, Jeremy D; Abt, Grant; Kilding, Andrew E

2010-12-01

The aim of this study was to determine the validity and reliability of a 90-minute soccer performance test: Ball-sport Endurance and Sprint Test (BEAST90). Fifteen healthy male amateur soccer players participated and attended 5 testing sessions over a 10-day period to perform physiologic and soccer-specific assessments. This included familiarization sessions and 2 full trials of the BEAST90, separated by 7 days. The total 90-minute distance, mean percent peak heart rate (HRpeak), and estimated percent peak oxygen uptake of the BEAST90 were 8,097 ± 458 m, 85 ± 5% and 82 ± 14%, respectively. Measures obtained from trial 1 and trial 2 were not significantly different (p > 0.05). Reliability of measures over 90 minutes ranged from 0.9-25.5% (% typical error). The BEAST90 protocol replicated soccer match play in terms of time, movement patterns, physical demands (volume and intensity), distances, and mean and HRpeak values, as well as having an aerobic load similar to that observed during a soccer match. Reproducibility of key physical measures during the BEAST90 were mostly high, suggesting good reliability. The BEAST90 could be used in studies that wish to determine the effects of training or nutritional interventions on prolonged intermittent physical performance.

Place avoidance learning and memory in a jumping spider.

PubMed

Peckmezian, Tina; Taylor, Phillip W

2017-03-01

Using a conditioned passive place avoidance paradigm, we investigated the relative importance of three experimental parameters on learning and memory in a salticid, Servaea incana. Spiders encountered an aversive electric shock stimulus paired with one side of a two-sided arena. Our three parameters were the ecological relevance of the visual stimulus, the time interval between trials and the time interval before test. We paired electric shock with either a black or white visual stimulus, as prior studies in our laboratory have demonstrated that S. incana prefer dark 'safe' regions to light ones. We additionally evaluated the influence of two temporal features (time interval between trials and time interval before test) on learning and memory. Spiders exposed to the shock stimulus learned to associate shock with the visual background cue, but the extent to which they did so was dependent on which visual stimulus was present and the time interval between trials. Spiders trained with a long interval between trials (24 h) maintained performance throughout training, whereas spiders trained with a short interval (10 min) maintained performance only when the safe side was black. When the safe side was white, performance worsened steadily over time. There was no difference between spiders tested after a short (10 min) or long (24 h) interval before test. These results suggest that the ecological relevance of the stimuli used and the duration of the interval between trials can influence learning and memory in jumping spiders.

Between-Trial Forgetting Due to Interference and Time in Motor Adaptation.

PubMed

Kim, Sungshin; Oh, Youngmin; Schweighofer, Nicolas

2015-01-01

Learning a motor task with temporally spaced presentations or with other tasks intermixed between presentations reduces performance during training, but can enhance retention post training. These two effects are known as the spacing and contextual interference effect, respectively. Here, we aimed at testing a unifying hypothesis of the spacing and contextual interference effects in visuomotor adaptation, according to which forgetting between trials due to either spaced presentations or interference by another task will promote between-trial forgetting, which will depress performance during acquisition, but will promote retention. We first performed an experiment with three visuomotor adaptation conditions: a short inter-trial-interval (ITI) condition (SHORT-ITI); a long ITI condition (LONG-ITI); and an alternating condition with two alternated opposite tasks (ALT), with the same single-task ITI as in LONG-ITI. In the SHORT-ITI condition, there was fastest increase in performance during training and largest immediate forgetting in the retention tests. In contrast, in the ALT condition, there was slowest increase in performance during training and little immediate forgetting in the retention tests. Compared to these two conditions, in the LONG-ITI, we found intermediate increase in performance during training and intermediate immediate forgetting. To account for these results, we fitted to the data six possible adaptation models with one or two time scales, and with interference in the fast, or in the slow, or in both time scales. Model comparison confirmed that two time scales and some degree of interferences in either time scale are needed to account for our experimental results. In summary, our results suggest that retention following adaptation is modulated by the degree of between-trial forgetting, which is due to time-based decay in single adaptation task and interferences in multiple adaptation tasks.

Cognitive Control: Dynamic, Sustained, and Voluntary Influences

ERIC Educational Resources Information Center

Fernandez-Duque, Diego; Knight, MaryBeth

2008-01-01

The cost of incongruent stimuli is reduced when conflict is expected. This series of experiments tested whether this improved performance is due to repetition priming or to enhanced cognitive control. Using a paradigm in which Word and Number Stroop alternated every trial, Experiment 1 assessed dynamic trial-to-trial changes. Incongruent trials…

Interference, aging, and visuospatial working memory: the role of similarity.

PubMed

Rowe, Gillian; Hasher, Lynn; Turcotte, Josée

2010-11-01

Older adults' performance on working memory (WM) span tasks is known to be negatively affected by the buildup of proactive interference (PI) across trials. PI has been reduced in verbal tasks and performance increased by presenting distinctive items across trials. In addition, reversing the order of trial presentation (i.e., starting with the longest sets first) has been shown to reduce PI in both verbal and visuospatial WM span tasks. We considered whether making each trial visually distinct would improve older adults' visuospatial WM performance, and whether combining the 2 PI-reducing manipulations, distinct trials and reversed order of presentation, would prove additive, thus providing even greater benefit. Forty-eight healthy older adults (age range = 60-77 years) completed 1 of 3 versions of a computerized Corsi block test. For 2 versions of the task, trials were either all visually similar or all visually distinct, and were presented in the standard ascending format (shortest set size first). In the third version, visually distinct trials were presented in a reverse order of presentation (longest set size first). Span scores were reliably higher in the ascending version for visually distinct compared with visually similar trials, F(1, 30) = 4.96, p = .03, η² = .14. However, combining distinct trials and a descending format proved no more beneficial than administering the descending format alone. Our findings suggest that a more accurate measurement of the visuospatial WM span scores of older adults (and possibly neuropsychological patients) might be obtained by reducing within-test interference.

Event-based proactive interference in rhesus monkeys.

PubMed

Devkar, Deepna T; Wright, Anthony A

2016-10-01

Three rhesus monkeys (Macaca mulatta) were tested in a same/different memory task for proactive interference (PI) from prior trials. PI occurs when a previous sample stimulus appears as a test stimulus on a later trial, does not match the current sample stimulus, and the wrong response "same" is made. Trial-unique pictures (scenes, objects, animals, etc.) were used on most trials, except on trials where the test stimulus matched potentially interfering sample stimulus from a prior trial (1, 2, 4, 8, or 16 trials prior). Greater interference occurred when fewer trials separated interference and test. PI functions showed a continuum of interference. Delays between sample and test stimuli and intertrial intervals were manipulated to test how PI might vary as a function of elapsed time. Contrary to a similar study with pigeons, these time manipulations had no discernable effect on the monkey's PI, as shown by compete overlap of PI functions with no statistical differences or interactions. These results suggested that interference was strictly based upon the number of intervening events (trials with other pictures) without regard to elapsed time. The monkeys' apparent event-based interference was further supported by retesting with a novel set of 1,024 pictures. PI from novel pictures 1 or 2 trials prior was greater than from familiar pictures, a familiar set of 1,024 pictures. Moreover, when potentially interfering novel stimuli were 16 trials prior, performance accuracy was actually greater than accuracy on baseline trials (no interference), suggesting that remembering stimuli from 16 trials prior was a cue that this stimulus was not the sample stimulus on the current trial-a somewhat surprising conclusion particularly given monkeys.

Intertrial Temporal Contextual Cuing: Association across Successive Visual Search Trials Guides Spatial Attention

ERIC Educational Resources Information Center

Ono, Fuminori; Jiang, Yuhong; Kawahara, Jun-ichiro

2005-01-01

Contextual cuing refers to the facilitation of performance in visual search due to the repetition of the same displays. Whereas previous studies have focused on contextual cuing within single-search trials, this study tested whether 1 trial facilitates visual search of the next trial. Participants searched for a T among Ls. In the training phase,…

The NO Regular Defibrillation testing In Cardioverter Defibrillator Implantation (NORDIC ICD) trial: concept and design of a randomized, controlled trial of intra-operative defibrillation testing during de novo defibrillator implantation.

PubMed

Bänsch, Dietmar; Bonnemeier, Hendrik; Brandt, Johan; Bode, Frank; Svendsen, Jesper Hastrup; Felk, Angelika; Hauser, Tino; Wegscheider, Karl

2015-01-01

Although defibrillation (DF) testing is still considered a standard procedure during implantable cardioverter-defibrillator (ICD) insertion and has been an essential element of all trials that demonstrated the survival benefit of ICD therapy, there are no large randomized clinical trials demonstrating that DF testing improves clinical outcome and if the outcome would remain the same by omitting DF testing. Between February 2011 and July 2013, we randomly assigned 1077 patients to ICD implantation with (n = 540) or without (n = 537) DF testing. The intra-operative DF testing was standardized across all participating centres. After inducing a fast ventricular tachycardia (VT) with a heart rate ≥240 b.p.m. or ventricular fibrillation (VF) with a low-energy T-wave shock, DF was attempted with an initial 15 J shock. If the shock reversed the VT or VF, DF testing was considered successful and terminated. If unsuccessful, two effective 24 J shocks were administered. If DF was unsuccessful, the system was reconfigured and another DF testing was performed. An ICD shock energy of 40 J had to be programmed in all patients for treatment of spontaneous VT/VF episodes. The primary endpoint was the average efficacy of the first ICD shock for all true VT/VF episodes in each patient during follow-up. The secondary endpoints included the frequency of system revisions, total fluoroscopy, implantation time, procedural serious adverse events, and all-cause, cardiac, and arrhythmic mortality during follow-up. Home Monitoring was used in all patients to continuously monitor the system integrity, device programming and performance. The NO Regular Defibrillation testing In Cardioverter Defibrillator Implantation (NORDIC ICD) trial is one of two large prospective randomized trials assessing the effect of DF testing omission during ICD implantation. NCT01282918. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Clinical trials transparency and the Trial and Experimental Studies Transparency (TEST) act.

PubMed

Logvinov, Ilana

2014-03-01

Clinical trial research is the cornerstone for successful advancement of medicine that provides hope for millions of people in the future. Full transparency in clinical trials may allow independent investigators to evaluate study designs, perform additional analysis of data, and potentially eliminate duplicate studies. Current regulatory system and publishers rely on investigators and pharmaceutical industries for complete and accurate reporting of results from completed clinical trials. Legislation seems to be the only way to enforce mandatory disclosure of results. The Trial and Experimental Studies Transparency (TEST) Act of 2012 was introduced to the legislators in the United States to promote greater transparency in research industry. Public safety and advancement of science are the driving forces for the proposed policy change. The TEST Act may benefit the society and researchers; however, there are major concerns with participants' privacy and intellectual property protection. Copyright © 2014 Elsevier Inc. All rights reserved.

Intact Associative Learning in Patients with Schizophrenia: Evidence from a Go/NoGo Paradigm

PubMed Central

Woolard, Austin A.; Kose, Samet; Woodward, Neil D.; Verbruggen, Frederick; Logan, Gordon D.; Heckers, Stephan

2010-01-01

Objective Schizophrenia is associated with deficits in executive control and associative learning. In the present study, we investigated the effect of associative learning during a Go/NoGo task in healthy controls subjects and patients with schizophrenia. Methods Thirty patients with schizophrenia and 30 age-and-gender matched healthy control subjects performed 15 blocks of training and 3 blocks of test trials. The trials consisted of responding to words denoting either living or non-living objects. In the training condition, subjects were instructed to respond by pressing the space bar (Go-task) to one of the word types (living or non-living objects), but not the other. In the test phase, the Go/NoGo mapping was reversed. Subjects were instructed to respond as quickly and as accurately as possible. Reaction times (RT) and accuracy were recorded for each trial and all subjects were debriefed upon completion of the test trials. Results Patients with schizophrenia had significantly longer Go RTs when compared to the control group, during both training and test trials. However, the two groups did not differ on any measure of associative learning. Conclusions Our findings suggest that associative learning is intact in schizophrenia patients during the performance of a relational Go/NoGo paradigm. PMID:20226631

Music Training Increases Phonological Awareness and Reading Skills in Developmental Dyslexia: A Randomized Control Trial

PubMed Central

Flaugnacco, Elena; Lopez, Luisa; Terribili, Chiara; Montico, Marcella; Zoia, Stefania; Schön, Daniele

2015-01-01

There is some evidence for a role of music training in boosting phonological awareness, word segmentation, working memory, as well as reading abilities in children with typical development. Poor performance in tasks requiring temporal processing, rhythm perception and sensorimotor synchronization seems to be a crucial factor underlying dyslexia in children. Interestingly, children with dyslexia show deficits in temporal processing, both in language and in music. Within this framework, we test the hypothesis that music training, by improving temporal processing and rhythm abilities, improves phonological awareness and reading skills in children with dyslexia. The study is a prospective, multicenter, open randomized controlled trial, consisting of test, rehabilitation and re-test (ID NCT02316873). After rehabilitation, the music group (N = 24) performed better than the control group (N = 22) in tasks assessing rhythmic abilities, phonological awareness and reading skills. This is the first randomized control trial testing the effect of music training in enhancing phonological and reading abilities in children with dyslexia. The findings show that music training can modify reading and phonological abilities even when these skills are severely impaired. Through the enhancement of temporal processing and rhythmic skills, music might become an important tool in both remediation and early intervention programs. Trial Registration ClinicalTrials.gov NCT02316873 PMID:26407242

Music Training Increases Phonological Awareness and Reading Skills in Developmental Dyslexia: A Randomized Control Trial.

PubMed

Flaugnacco, Elena; Lopez, Luisa; Terribili, Chiara; Montico, Marcella; Zoia, Stefania; Schön, Daniele

2015-01-01

There is some evidence for a role of music training in boosting phonological awareness, word segmentation, working memory, as well as reading abilities in children with typical development. Poor performance in tasks requiring temporal processing, rhythm perception and sensorimotor synchronization seems to be a crucial factor underlying dyslexia in children. Interestingly, children with dyslexia show deficits in temporal processing, both in language and in music. Within this framework, we test the hypothesis that music training, by improving temporal processing and rhythm abilities, improves phonological awareness and reading skills in children with dyslexia. The study is a prospective, multicenter, open randomized controlled trial, consisting of test, rehabilitation and re-test (ID NCT02316873). After rehabilitation, the music group (N = 24) performed better than the control group (N = 22) in tasks assessing rhythmic abilities, phonological awareness and reading skills. This is the first randomized control trial testing the effect of music training in enhancing phonological and reading abilities in children with dyslexia. The findings show that music training can modify reading and phonological abilities even when these skills are severely impaired. Through the enhancement of temporal processing and rhythmic skills, music might become an important tool in both remediation and early intervention programs.Trial Registration: ClinicalTrials.gov NCT02316873

Clinical Neuropathology practice news 1-2014: Pyrosequencing meets clinical and analytical performance criteria for routine testing of MGMT promoter methylation status in glioblastoma

PubMed Central

Preusser, Matthias; Berghoff, Anna S.; Manzl, Claudia; Filipits, Martin; Weinhäusel, Andreas; Pulverer, Walter; Dieckmann, Karin; Widhalm, Georg; Wöhrer, Adelheid; Knosp, Engelbert; Marosi, Christine; Hainfellner, Johannes A.

2014-01-01

Testing of the MGMT promoter methylation status in glioblastoma is relevant for clinical decision making and research applications. Two recent and independent phase III therapy trials confirmed a prognostic and predictive value of the MGMT promoter methylation status in elderly glioblastoma patients. Several methods for MGMT promoter methylation testing have been proposed, but seem to be of limited test reliability. Therefore, and also due to feasibility reasons, translation of MGMT methylation testing into routine use has been protracted so far. Pyrosequencing after prior DNA bisulfite modification has emerged as a reliable, accurate, fast and easy-to-use method for MGMT promoter methylation testing in tumor tissues (including formalin-fixed and paraffin-embedded samples). We performed an intra- and inter-laboratory ring trial which demonstrates a high analytical performance of this technique. Thus, pyrosequencing-based assessment of MGMT promoter methylation status in glioblastoma meets the criteria of high analytical test performance and can be recommended for clinical application, provided that strict quality control is performed. Our article summarizes clinical indications, practical instructions and open issues for MGMT promoter methylation testing in glioblastoma using pyrosequencing. PMID:24359605

Impact on learning of an e-learning module on leukaemia: a randomised controlled trial.

PubMed

Morgulis, Yuri; Kumar, Rakesh K; Lindeman, Robert; Velan, Gary M

2012-05-28

e-learning resources may be beneficial for complex or conceptually difficult topics. Leukaemia is one such topic, yet there are no reports on the efficacy of e-learning for leukaemia. This study compared the learning impact on senior medical students of a purpose-built e-learning module on leukaemia, compared with existing online resources. A randomised controlled trial was performed utilising volunteer senior medical students. Participants were randomly allocated to Study and Control groups. Following a pre-test on leukaemia administered to both groups, the Study group was provided with access to the new e-learning module, while the Control group was directed to existing online resources. A post-test and an evaluation questionnaire were administered to both groups at the end of the trial period. Study and Control groups were equivalent in gender distribution, mean academic ability, pre-test performance and time studying leukaemia during the trial. The Study group performed significantly better than the Control group in the post-test, in which the group to which the students had been allocated was the only significant predictor of performance. The Study group's evaluation of the module was overwhelmingly positive. A targeted e-learning module on leukaemia had a significant effect on learning in this cohort, compared with existing online resources. We believe that the interactivity, dialogic feedback and integration with the curriculum offered by the e-learning module contributed to its impact. This has implications for e-learning design in medicine and other disciplines.

Analysis of Classical Time-Trial Performance and Technique-Specific Physiological Determinants in Elite Female Cross-Country Skiers.

PubMed

Sandbakk, Øyvind; Losnegard, Thomas; Skattebo, Øyvind; Hegge, Ann M; Tønnessen, Espen; Kocbach, Jan

2016-01-01

The present study investigated the contribution of performance on uphill, flat, and downhill sections to overall performance in an international 10-km classical time-trial in elite female cross-country skiers, as well as the relationships between performance on snow and laboratory-measured physiological variables in the double poling (DP) and diagonal (DIA) techniques. Ten elite female cross-country skiers were continuously measured by a global positioning system device during an international 10-km cross-country skiing time-trial in the classical technique. One month prior to the race, all skiers performed a 5-min submaximal and 3-min self-paced performance test while roller skiing on a treadmill, both in the DP and DIA techniques. The time spent on uphill (r = 0.98) and flat (r = 0.91) sections of the race correlated most strongly with the overall 10-km performance (both p < 0.05). Approximately 56% of the racing time was spent uphill, and stepwise multiple regression revealed that uphill time explained 95.5% of the variance in overall performance (p < 0.001). Distance covered during the 3-min roller-skiing test and body-mass normalized peak oxygen uptake (VO2peak) in both techniques showed the strongest correlations with overall time-trial performance (r = 0.66-0.78), with DP capacity tending to have greatest impact on the flat and DIA capacity on uphill terrain (all p < 0.05). Our present findings reveal that the time spent uphill most strongly determine classical time-trial performance, and that the major portion of the performance differences among elite female cross-country skiers can be explained by variations in technique-specific aerobic power.

Analysis of Classical Time-Trial Performance and Technique-Specific Physiological Determinants in Elite Female Cross-Country Skiers

PubMed Central

Sandbakk, Øyvind; Losnegard, Thomas; Skattebo, Øyvind; Hegge, Ann M.; Tønnessen, Espen; Kocbach, Jan

2016-01-01

The present study investigated the contribution of performance on uphill, flat, and downhill sections to overall performance in an international 10-km classical time-trial in elite female cross-country skiers, as well as the relationships between performance on snow and laboratory-measured physiological variables in the double poling (DP) and diagonal (DIA) techniques. Ten elite female cross-country skiers were continuously measured by a global positioning system device during an international 10-km cross-country skiing time-trial in the classical technique. One month prior to the race, all skiers performed a 5-min submaximal and 3-min self-paced performance test while roller skiing on a treadmill, both in the DP and DIA techniques. The time spent on uphill (r = 0.98) and flat (r = 0.91) sections of the race correlated most strongly with the overall 10-km performance (both p < 0.05). Approximately 56% of the racing time was spent uphill, and stepwise multiple regression revealed that uphill time explained 95.5% of the variance in overall performance (p < 0.001). Distance covered during the 3-min roller-skiing test and body-mass normalized peak oxygen uptake (VO2peak) in both techniques showed the strongest correlations with overall time-trial performance (r = 0.66–0.78), with DP capacity tending to have greatest impact on the flat and DIA capacity on uphill terrain (all p < 0.05). Our present findings reveal that the time spent uphill most strongly determine classical time-trial performance, and that the major portion of the performance differences among elite female cross-country skiers can be explained by variations in technique-specific aerobic power. PMID:27536245

Blast Performance of Commercially Available Demining Footwear: A Summary of Experimental Trials on Surrogate Legs

DTIC Science & Technology

2008-10-01

Equipment Department of the Dutch Ministry of Defence tasked TNO Defence, Security and Safety to perform AP mine shoe tests to study the protection level...would not provide more insight. Therefore only two tests at 75 g were performed . The test results are summarized in Table 2. The high speed video...be able to better place foot into shoe . But still damage of gelatine prior to test. Pretest x-ray performed to show damage prior to test. The

Ten years later: Evaluation of the effectiveness of 12.5% amitraz against a field population of Rhipicephalus (Boophilus) microplus using field studies, artificial infestation (Stall tests) and adult immersion tests.

PubMed

Maciel, Willian Giquelin; Lopes, Welber Daniel Zanetti; Cruz, Breno Cayeiro; Gomes, Lucas Vinicius Costa; Teixeira, Weslen Fabrício Pires; Buzzulini, Carolina; Bichuette, Murilo Abud; Campos, Gabriel Pimentel; Felippelli, Gustavo; Soares, Vando Edésio; de Oliveira, Gilson Pereira; da Costa, Alvimar José

2015-12-15

Using field trials, artificial infestations (Stall tests) and in vitro adult immersion tests, the present study evaluated the acaricidal efficacy of 12.5% amitraz administered via whole body spraying against a Rhipicephalus (Boophilus) microplus population that did not have any contact with chemical products belonging to this acaricide family for 10 years (approximately 40 generations). Two natural infestation trials, two artificial infestation trials (Stall tests) and two adult immersion tests were performed in two different stages in 2005 and 2015. Between 2002 and 2015, the bovine herd of this property was formed by approximately 450 animals from the Simmental breed that were divided into nine paddocks formed by Cynodon dactylon (L.) Pers. For the natural infestation experiments in 2005 and 2015, we selected nearly 70 animals naturally infested with ticks from the same herd that belonged to the "São Paulo" farm located in São José do Rio Pardo, São Paulo, Brazil. Field studies were performed in the same paddock (9). To evaluate anti-R. (B.) microplus activity in the artificially infested cattle (Stall tests) and adult immersion tests, two experiments of each methodology were performed at CPPAR (the Center of Research in Animal Health located on the FCAV/UNESP campus in Jaboticabal, São Paulo, Brazil) in 2005 and 2015. R. (B.) microplus used in the artificial infestation, and adult immersion test experiments were obtained from paddocks 1-9 in 2005 and 2015 from the commercial farm where the field studies were performed. Based on the obtained results, it was possible to conclude that amitraz use in rotation with pyrethroids every 28 days for three consecutive years (2002-2004) previous to the beginning of the first trial (2005) was sufficient to generate a R. (B.) microplus strain resistant to amitraz. Moreover, using field trials, artificial infestations (Stall tests) and adult immersion tests, we verified that 40 generations of the tick species with no contact to the aforementioned compound (amitraz) were not sufficient to revert or modify the efficacy/resistance of amitraz for this analyzed R. (B.) microplus strain. The reversion of amitraz efficacy values in R. (B.) microplus may only occur when resistance of the field strain is incipient. Alternatively, the differences in the results may be due to differences in the Rhipicephalus spp. species between current study locations. Therefore, future studies must be performed to prove this hypothesis. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of Administrator Performance on Student Performance in the Trial State Assessment.

ERIC Educational Resources Information Center

McLaughlin, Donald H.

In 1990 the scope of the National Assessment of Educational Progress (NAEP) was broadened by adding the Trial State Assessment (TSA), in which approximately 2,500 eighth graders in 100 schools in 40 states and U.S. territories participated in the mathematics assessment. A major step was training local test administrators to administer the TSA…

University Students' Attainment and Perceptions of Computer Delivered Assessment; A Comparison between Computer-Based and Traditional Tests in a "High-Stakes" Examination

ERIC Educational Resources Information Center

Escudier, M. P.; Newton, T. J.; Cox, M. J.; Reynolds, P. A.; Odell, E. W.

2011-01-01

This study compared higher education dental undergraduate student performance in online assessments with performance in traditional paper-based tests and investigated students' perceptions of the fairness and acceptability of online tests, and showed performance to be comparable. The project design involved two parallel cross-over trials, one in…

Relative and absolute reliability of the clinical version of the Narrow Path Walking Test (NPWT) under single and dual task conditions.

PubMed

Gimmon, Yoav; Jacob, Grinshpon; Lenoble-Hoskovec, Constanze; Büla, Christophe; Melzer, Itshak

2013-01-01

Decline in gait stability has been associated with increased fall risk in older adults. Reliable and clinically feasible methods of gait instability assessment are needed. This study evaluated the relative and absolute reliability and concurrent validity of the testing procedure of the clinical version of the Narrow Path Walking Test (NPWT) under single task (ST) and dual task (DT) conditions. Thirty independent community-dwelling older adults (65-87 years) were tested twice. Participants were instructed to walk within the 6-m narrow path without stepping out. Trial time, number of steps, trial velocity, number of step errors, and number of cognitive task errors were determined. Intraclass correlation coefficients (ICCs) were calculated as indices of agreement, and a graphic approach called "mountain plot" was applied to help interpret the direction and magnitude of disagreements between testing procedures. Smallest detectable change and smallest real difference (SRD) were computed to determine clinically relevant improvement at group and individual levels, respectively. Concurrent validity was assessed using Performance Oriented Mobility Assessment Tool (POMA) and the Short Physical Performance Battery (SPPB). Test-retest agreement (ICC1,2) varied from 0.77 to 0.92 in ST and from 0.78 to 0.92 in DT conditions, with no apparent systematic differences between testing procedures demonstrated by the mountain plot graphs. Smallest detectable change and smallest real change were small for motor task performance and larger for cognitive errors. Significant correlations were observed for trial velocity and trial time with POMA and SPPB. The present results indicate that the NPWT testing procedure is highly reliable and reproducible. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Defining standardized protocols for determining the efficacy of a postmilking teat disinfectant following experimental exposure of teats to mastitis pathogens.

PubMed

Schukken, Y H; Rauch, B J; Morelli, J

2013-04-01

The objective of this paper was to define standardized protocols for determining the efficacy of a postmilking teat disinfectant following experimental exposure of teats to both Staphylococcus aureus and Streptococcus agalactiae. The standardized protocols describe the selection of cows and herds and define the critical points in performing experimental exposure, performing bacterial culture, evaluating the culture results, and finally performing statistical analyses and reporting of the results. The protocols define both negative control and positive control trials. For negative control trials, the protocol states that an efficacy of reducing new intramammary infections (IMI) of at least 40% is required for a teat disinfectant to be considered effective. For positive control trials, noninferiority to a control disinfectant with a published efficacy of reducing new IMI of at least 70% is required. Sample sizes for both negative and positive control trials are calculated. Positive control trials are expected to require a large trial size. Statistical analysis methods are defined and, in the proposed methods, the rate of IMI may be analyzed using generalized linear mixed models. The efficacy of the test product can be evaluated while controlling for important covariates and confounders in the trial. Finally, standards for reporting are defined and reporting considerations are discussed. The use of the defined protocol is shown through presentation of the results of a recent trial of a test product against a negative control. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of a 4-week high-intensity interval training on pacing during 5-km running trial

PubMed Central

Silva, R.; Damasceno, M.; Cruz, R.; Silva-Cavalcante, M.D.; Lima-Silva, A.E.; Bishop, D.J.; Bertuzzi, R.

2017-01-01

This study analyzed the influence of a 4-week high-intensity interval training on the pacing strategy adopted by runners during a 5-km running trial. Sixteen male recreational long-distance runners were randomly assigned to a control group (CON, n=8) or a high-intensity interval training group (HIIT, n=8). The HIIT group performed high-intensity interval-training twice per week, while the CON group maintained their regular training program. Before and after the training period, the runners performed an incremental exercise test to exhaustion to measure the onset of blood lactate accumulation, maximal oxygen uptake (VO2max), and peak treadmill speed (PTS). A submaximal constant-speed test to measure the running economy (RE) and a 5-km running trial on an outdoor track to establish pacing strategy and performance were also done. During the 5-km running trial, the rating of perceived exertion (RPE) and time to cover the 5-km trial (T5) were registered. After the training period, there were significant improvements in the HIIT group of ∼7 and 5% for RE (P=0.012) and PTS (P=0.019), respectively. There was no significant difference between the groups for VO2max (P=0.495) or onset of blood lactate accumulation (P=0.101). No difference was found in the parameters measured during the 5-km trial before the training period between HIIT and CON (P>0.05). These findings suggest that 4 weeks of HIIT can improve some traditional physiological variables related to endurance performance (RE and PTS), but it does not alter the perception of effort, pacing strategy, or overall performance during a 5-km running trial. PMID:29069224

Effects of a 4-week high-intensity interval training on pacing during 5-km running trial.

PubMed

Silva, R; Damasceno, M; Cruz, R; Silva-Cavalcante, M D; Lima-Silva, A E; Bishop, D J; Bertuzzi, R

2017-10-19

This study analyzed the influence of a 4-week high-intensity interval training on the pacing strategy adopted by runners during a 5-km running trial. Sixteen male recreational long-distance runners were randomly assigned to a control group (CON, n=8) or a high-intensity interval training group (HIIT, n=8). The HIIT group performed high-intensity interval-training twice per week, while the CON group maintained their regular training program. Before and after the training period, the runners performed an incremental exercise test to exhaustion to measure the onset of blood lactate accumulation, maximal oxygen uptake (VO2max), and peak treadmill speed (PTS). A submaximal constant-speed test to measure the running economy (RE) and a 5-km running trial on an outdoor track to establish pacing strategy and performance were also done. During the 5-km running trial, the rating of perceived exertion (RPE) and time to cover the 5-km trial (T5) were registered. After the training period, there were significant improvements in the HIIT group of ∼7 and 5% for RE (P=0.012) and PTS (P=0.019), respectively. There was no significant difference between the groups for VO2max (P=0.495) or onset of blood lactate accumulation (P=0.101). No difference was found in the parameters measured during the 5-km trial before the training period between HIIT and CON (P>0.05). These findings suggest that 4 weeks of HIIT can improve some traditional physiological variables related to endurance performance (RE and PTS), but it does not alter the perception of effort, pacing strategy, or overall performance during a 5-km running trial.

A studentized permutation test for three-arm trials in the 'gold standard' design.

PubMed

Mütze, Tobias; Konietschke, Frank; Munk, Axel; Friede, Tim

2017-03-15

The 'gold standard' design for three-arm trials refers to trials with an active control and a placebo control in addition to the experimental treatment group. This trial design is recommended when being ethically justifiable and it allows the simultaneous comparison of experimental treatment, active control, and placebo. Parametric testing methods have been studied plentifully over the past years. However, these methods often tend to be liberal or conservative when distributional assumptions are not met particularly with small sample sizes. In this article, we introduce a studentized permutation test for testing non-inferiority and superiority of the experimental treatment compared with the active control in three-arm trials in the 'gold standard' design. The performance of the studentized permutation test for finite sample sizes is assessed in a Monte Carlo simulation study under various parameter constellations. Emphasis is put on whether the studentized permutation test meets the target significance level. For comparison purposes, commonly used Wald-type tests, which do not make any distributional assumptions, are included in the simulation study. The simulation study shows that the presented studentized permutation test for assessing non-inferiority in three-arm trials in the 'gold standard' design outperforms its competitors, for instance the test based on a quasi-Poisson model, for count data. The methods discussed in this paper are implemented in the R package ThreeArmedTrials which is available on the comprehensive R archive network (CRAN). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Feasibility of the adaptive and automatic presentation of tasks (ADAPT) system for rehabilitation of upper extremity function post-stroke.

PubMed

Choi, Younggeun; Gordon, James; Park, Hyeshin; Schweighofer, Nicolas

2011-08-03

Current guidelines for rehabilitation of arm and hand function after stroke recommend that motor training focus on realistic tasks that require reaching and manipulation and engage the patient intensively, actively, and adaptively. Here, we investigated the feasibility of a novel robotic task-practice system, ADAPT, designed in accordance with such guidelines. At each trial, ADAPT selects a functional task according to a training schedule and with difficulty based on previous performance. Once the task is selected, the robot picks up and presents the corresponding tool, simulates the dynamics of the tasks, and the patient interacts with the tool to perform the task. Five participants with chronic stroke with mild to moderate impairments (> 9 months post-stroke; Fugl-Meyer arm score 49.2 ± 5.6) practiced four functional tasks (selected out of six in a pre-test) with ADAPT for about one and half hour and 144 trials in a pseudo-random schedule of 3-trial blocks per task. No adverse events occurred and ADAPT successfully presented the six functional tasks without human intervention for a total of 900 trials. Qualitative analysis of trajectories showed that ADAPT simulated the desired task dynamics adequately, and participants reported good, although not excellent, task fidelity. During training, the adaptive difficulty algorithm progressively increased task difficulty leading towards an optimal challenge point based on performance; difficulty was then continuously adjusted to keep performance around the challenge point. Furthermore, the time to complete all trained tasks decreased significantly from pretest to one-hour post-test. Finally, post-training questionnaires demonstrated positive patient acceptance of ADAPT. ADAPT successfully provided adaptive progressive training for multiple functional tasks based on participant's performance. Our encouraging results establish the feasibility of ADAPT; its efficacy will next be tested in a clinical trial.

The cognitive-enhancing effects of Bacopa monnieri: a systematic review of randomized, controlled human clinical trials.

PubMed

Pase, Matthew P; Kean, James; Sarris, Jerome; Neale, Chris; Scholey, Andrew B; Stough, Con

2012-07-01

Traditional knowledge suggests that Bacopa monnieri enhances cognitive performance. Such traditional beliefs have now been scientifically tested through a handful of randomized, controlled human clinical trials. The current systematic review aimed to examine the scientific evidence as to whether Bacopa can enhance cognitive performance in humans. A systematic review of randomized controlled trials is presented. Multiple databases were systematically searched by multiple authors. Relevant trials were objectively assessed for methodological quality. The subjects studied were adult humans without dementia or significant cognitive impairment. B. monnieri, including Bacopa extracts, were administered over long-term supplementation periods. Any validated cognitive test, whether a primary or secondary outcome. Six (6) studies met the final inclusion criteria and were included in review. Trials were all conducted over 12 weeks. Across trials, three different Bacopa extracts were used at dosages of 300-450 mg extract per day. All reviewed trials examined the effects of Bacopa on memory, while other cognitive domains were less well studied. There were no cognitive tests in the areas of auditory perceptual abilities or idea production and only a paucity of research in the domains of reasoning, number facility, and language behavior. Across studies, Bacopa improved performance on 9 of 17 tests in the domain of memory free recall. There was little evidence of enhancement in any other cognitive domains. There is some evidence to suggest that Bacopa improves memory free recall with evidence for enhancement in other cognitive abilities currently lacking perhaps due to inconsistent measures employed by studies across these cognitive domains. Research into the nootropic effects of Bacopa is in its infancy, with research still yet to investigate the effects of Bacopa across all human cognitive abilities. Similarly, future research should examine the nootropic effects of Bacopa at varied dosages and across different extracts.

Development of a battery of functional tests for low vision.

PubMed

Dougherty, Bradley E; Martin, Scott R; Kelly, Corey B; Jones, Lisa A; Raasch, Thomas W; Bullimore, Mark A

2009-08-01

We describe the development and evaluation of a battery of tests of functional visual performance of everyday tasks intended to be suitable for assessment of low vision patients. The functional test battery comprises-Reading rate: reading aloud 20 unrelated words for each of four print sizes (8, 4, 2, & 1 M); Telephone book: finding a name and reading the telephone number; Medicine bottle label: reading the name and dosing; Utility bill: reading the due date and amount due; Cooking instructions: reading cooking time on a food package; Coin sorting: making a specified amount from coins placed on a table; Playing card recognition: identifying denomination and suit; and Face recognition: identifying expressions of printed, life-size faces at 1 and 3 m. All tests were timed except face and playing card recognition. Fourteen normally sighted and 24 low vision subjects were assessed with the functional test battery. Visual acuity, contrast sensitivity, and quality of life (National Eye Institute Visual Function Questionnaire 25 [NEI-VFQ 25]) were measured and the functional tests repeated. Subsequently, 23 low vision patients participated in a pilot randomized clinical trial with half receiving low vision rehabilitation and half a delayed intervention. The functional tests were administered at enrollment and 3 months later. Normally sighted subjects could perform all tasks but the proportion of trials performed correctly by the low vision subjects ranged from 35% for face recognition at 3 m, to 95% for the playing card identification. On average, low vision subjects performed three times slower than the normally sighted subjects. Timed tasks with a visual search component showed poorer repeatability. In the pilot clinical trial, low vision rehabilitation produced the greatest improvement for the medicine bottle and cooking instruction tasks. Performance of patients on these functional tests has been assessed. Some appear responsive to low vision rehabilitation.

Associations of Adiposity and Aerobic Fitness with Executive Function and Math Performance in Danish Adolescents.

PubMed

Huang, Tao; Tarp, Jakob; Domazet, Sidsel Louise; Thorsen, Anne Kær; Froberg, Karsten; Andersen, Lars Bo; Bugge, Anna

2015-10-01

To examine the associations of adiposity and aerobic fitness with executive function and math performance in Danish adolescents. Cross-sectional analyses were conducted with data on 525 adolescents attending sixth and seventh grades from 14 schools in the 5 main regions of Denmark. A modified Eriksen flanker task was used to assess inhibitory control, a key aspect of executive function. Academic performance was assessed by a customized math test. Aerobic fitness was assessed by an intermittent shuttle-run test (Andersen test). Body mass index (BMI) was negatively associated with accuracy on incongruent trials during the flanker task (P = .005). A higher BMI was associated with a larger accuracy interference score (P = .01). Similarly, waist circumference (WC) was negatively associated with accuracy on incongruent trials (P = .008). A higher WC was associated with a larger reaction time (RT) interference score (P = .02) and accuracy interference score (P = .009). Higher aerobic fitness was associated with a faster RT on congruent trials (P = .009) and incongruent trials (P = .003). Higher aerobic fitness was associated with a smaller RT interference score (P = .04). Aerobic fitness was positively associated with math score (P < .001). BMI and WC were not associated with math score (P > .05). These results suggest that aerobic fitness is positively associated with both inhibitory control and math performance in adolescents. Adiposity is negatively associated with inhibitory control in adolescents. Adiposity is not associated with math performance. Copyright © 2015 Elsevier Inc. All rights reserved.

A Randomized Controlled Trial of Acceptance-Based Behavior Therapy and Cognitive Therapy for Test Anxiety: A Pilot Study

ERIC Educational Resources Information Center

Brown, Lily A.; Forman, Evan M.; Herbert, James D.; Hoffman, Kimberly L.; Yuen, Erica K.; Goetter, Elizabeth M.

2011-01-01

Many university students suffer from test anxiety that is severe enough to impair performance. Given mixed efficacy results of previous cognitive-behavior therapy (CBT) trials and a theoretically driven rationale, an acceptance-based behavior therapy (ABBT) approach was compared to traditional CBT (i.e., Beckian cognitive therapy; CT) for the…

Evaluation of a Short-Form of the Berg Card Sorting Test

PubMed Central

Fox, Christopher J.; Mueller, Shane T.; Gray, Hilary M.; Raber, Jacob; Piper, Brian J.

2013-01-01

The Psychology Experimental Building Language http://pebl.sourceforge.net/ Berg Card Sorting Test is an open-source neurobehavioral test. Participants (N = 207, ages 6 to 74) completed the Berg Card Sorting Test. Performance on the first 64 trials were isolated and compared to that on the full-length (128 trials) test. Strong correlations between the short and long forms (total errors: r = .87, perseverative response: r = .83, perseverative errors r = .77, categories completed r = .86) support the Berg Card Sorting Test-64 as an abbreviated alternative for the full-length executive function test. PMID:23691107

Influence of low versus moderate glycemic index of diet on substrate oxidation and energy expenditure during incremental exercise in endurance athletes: a randomized counterbalanced cross-over trial.

PubMed

Durkalec-Michalski, Krzysztof; Zawieja, Emilia Ewa; Zawieja, Bogna Ewa; Podgórski, Tomasz; Jurkowska, Dominika; Jeszka, Jan

2017-12-18

The study was aimed at assessing the influence of 3-week low glycemic index (LGI) versus moderate glycemic index (MGI) diet on substrate oxidation during incremental exercise. 17 runners completed two 3-week trials of either LGI or MGI diet in a randomised counterbalanced manner. Before and after each trial the incremental cycling test was performed. Metabolic alternations were observed only within tested diets and no significant differences in fat and carbohydrate (CHO) oxidation were found between MGI and LGI diets. Following MGI diet CHO oxidation rate increased. The AUC of fat oxidation decreased after both diets. Percent contribution of fat to energy yield declined, whereas contribution of CHO was augmented following MGI diet. This study indicates that the 3-week MGI diet increased the rate of carbohydrate oxidation during incremental cycling test and improved performance in acute intense exercise test, while both high-carbohydrate diets downregulated fat oxidation rate.

Effect of recovery interventions on cycling performance and pacing strategy in the heat.

PubMed

De Pauw, Kevin; Roelands, Bart; Vanparijs, Jef; Meeusen, Romain

2014-03-01

To determine the effect of active recovery (AR), passive rest (PR), and cold-water immersion (CWI) after 90 min of intensive cycling on a subsequent 12-min time trial (TT2) and the applied pacing strategy in TT2. After a maximal test and familiarization trial, 9 trained male subjects (age 22 ± 3 y, VO2max 62.1 ± 5.3 mL · min-1 · kg-1) performed 3 experimental trials in the heat (30°C). Each trial consisted of 2 exercise tasks separated by 1 h. The first was a 60-min constant-load trial at 55% of the maximal power output followed by a 30-min time trial (TT1). The second comprised a 12-min simulated time trial (TT2). After TT1, AR, PR, or CWI was applied for 15 min. No significant TT2 performance differences were observed, but a 1-sample t test (within each condition) revealed different pacing strategies during TT2. CWI resulted in an even pacing strategy, while AR and PR resulted in a gradual decline of power output after the onset of TT2 (P ≤ .046). During recovery, AR and CWI showed a trend toward faster blood lactate ([BLa]) removal, but during TT2 significantly higher [BLa] was only observed after CWI compared with PR (P = .011). The pacing strategy during subsequent cycling performance in the heat is influenced by the application of different postexercise recovery interventions. Although power was not significantly altered between groups, CWI enabled a differently shaped power profile, likely due to decreased thermal strain.

Average is optimal: an inverted-U relationship between trial-to-trial brain activity and behavioral performance.

PubMed

He, Biyu J; Zempel, John M

2013-01-01

It is well known that even under identical task conditions, there is a tremendous amount of trial-to-trial variability in both brain activity and behavioral output. Thus far the vast majority of event-related potential (ERP) studies investigating the relationship between trial-to-trial fluctuations in brain activity and behavioral performance have only tested a monotonic relationship between them. However, it was recently found that across-trial variability can correlate with behavioral performance independent of trial-averaged activity. This finding predicts a U- or inverted-U- shaped relationship between trial-to-trial brain activity and behavioral output, depending on whether larger brain variability is associated with better or worse behavior, respectively. Using a visual stimulus detection task, we provide evidence from human electrocorticography (ECoG) for an inverted-U brain-behavior relationship: When the raw fluctuation in broadband ECoG activity is closer to the across-trial mean, hit rate is higher and reaction times faster. Importantly, we show that this relationship is present not only in the post-stimulus task-evoked brain activity, but also in the pre-stimulus spontaneous brain activity, suggesting anticipatory brain dynamics. Our findings are consistent with the presence of stochastic noise in the brain. They further support attractor network theories, which postulate that the brain settles into a more confined state space under task performance, and proximity to the targeted trajectory is associated with better performance.

Developmental Progression of Looking and Reaching Performance on the A-not-B Task

PubMed Central

Cuevas, Kimberly; Bell, Martha Ann

2013-01-01

From a neuropsychological perspective, the cognitive skills of working memory, inhibition, and attention and the maturation of the frontal lobe are requisites for successful A-not-B performance on both the looking and reaching versions of the task. This study used a longitudinal design to examine the developmental progression of infants’ performance on the looking and reaching versions of the A-not-B task. Twenty infants were tested on both versions of the task once a month from 5 to 10 months of age. Infants had higher object permanence scores on the looking version of the task from 5 to 8 months, with comparable performance across response modalities at 9 and 10 months. The same pattern of performance was found on nonreversal (A) trials: Infants performed better on looking trials from 5 to 7 months and they performed equally on both response trials from 8 to 10 months. Overall, infants performed better on looking reversal (B) trials than reaching reversal trials. These data suggest that performance differences between response modalities early in development can be attributed to major differences in the maturation of brain circuitry associated with the actual task response. PMID:20822245

Using pathology-specific laboratory profiles in Clinical Pathology to reduce inappropriate test requesting: two completed audit cycles

PubMed Central

2012-01-01

Background Systematic reviews have shown that, although well prepared, the Consensus Guidelines have failed to change clinical practice. In the healthcare district of Castelnovo né Monti (Reggio Emilia, Italy), it became necessary for the GPs and Clinical Pathologists to work together to jointly define laboratory profiles. Methods Observational study with two cycles of retrospective audit on test request forms, in a primary care setting. Objectives of the study were to develop pathology-specific laboratory profiles and to increase the number of provisional diagnoses on laboratory test request forms. A Multiprofessional Multidisciplinary Inter-hospital Work Team developed pathology-specific laboratory profiles for more effective test requesting. After 8 training sessions that used a combined strategy with multifaceted interventions, the 23 General Practitioners (GPs) in the trial district (Castelnovo nè Monti) tested the profiles; the 21 GPs in the Puianello district were the control group; all GPs in both districts participated in the trial. All laboratory tests for both healthcare districts are performed at the Laboratory located in the trial district. A baseline and a 1-year audit were performed in both districts on the GPs’ request forms. Results Seven pathology-specific laboratory profiles for outpatients were developed. In the year after the first audit cycle: 1) the number of tests requested in the trial district was distinctly lower than that in the previous year, with a decrease of about 5% (p < 0.001); 2) the provisional diagnosis on the request forms was 52.8% in the trial district and 42% in the control district (P < 0.001); 3) the decrease of the number of tests on each request form was much more marked in the trial district (8.73 vs. 10.77; p < 0.001). Conclusions The first audit cycle showed a significant decrease in the number of tests ordered only in the trial district. The combined strategy used in this study improved the prescriptive compliance of most of the GPs involved. The presence of the clinical pathologist is seen as an added value. PMID:22759353

Using pathology-specific laboratory profiles in clinical pathology to reduce inappropriate test requesting: two completed audit cycles.

PubMed

Baricchi, Roberto; Zini, Michele; Nibali, Maria Grazia; Vezzosi, Walter; Insegnante, Vincenzo; Manfuso, Clotilde; Polese, Alessandra; Costoli, Valmer; Spelti, Antonio; Formisano, Debora; Orlandini, Danilo; Nicolini, Fausto; Poli, Antonio

2012-07-03

Systematic reviews have shown that, although well prepared, the Consensus Guidelines have failed to change clinical practice. In the healthcare district of Castelnovo né Monti (Reggio Emilia, Italy), it became necessary for the GPs and Clinical Pathologists to work together to jointly define laboratory profiles. Observational study with two cycles of retrospective audit on test request forms, in a primary care setting. Objectives of the study were to develop pathology-specific laboratory profiles and to increase the number of provisional diagnoses on laboratory test request forms. A Multiprofessional Multidisciplinary Inter-hospital Work Team developed pathology-specific laboratory profiles for more effective test requesting. After 8 training sessions that used a combined strategy with multifaceted interventions, the 23 General Practitioners (GPs) in the trial district (Castelnovo nè Monti) tested the profiles; the 21 GPs in the Puianello district were the control group; all GPs in both districts participated in the trial. All laboratory tests for both healthcare districts are performed at the Laboratory located in the trial district. A baseline and a 1-year audit were performed in both districts on the GPs' request forms. Seven pathology-specific laboratory profiles for outpatients were developed. In the year after the first audit cycle: 1) the number of tests requested in the trial district was distinctly lower than that in the previous year, with a decrease of about 5% (p < 0.001); 2) the provisional diagnosis on the request forms was 52.8% in the trial district and 42% in the control district (P < 0.001); 3) the decrease of the number of tests on each request form was much more marked in the trial district (8.73 vs. 10.77; p < 0.001). The first audit cycle showed a significant decrease in the number of tests ordered only in the trial district. The combined strategy used in this study improved the prescriptive compliance of most of the GPs involved. The presence of the clinical pathologist is seen as an added value.

A statistical characterization of the finger tapping test: modeling, estimation, and applications.

PubMed

Austin, Daniel; McNames, James; Klein, Krystal; Jimison, Holly; Pavel, Misha

2015-03-01

Sensory-motor performance is indicative of both cognitive and physical function. The Halstead-Reitan finger tapping test is a measure of sensory-motor speed commonly used to assess function as part of a neuropsychological evaluation. Despite the widespread use of this test, the underlying motor and cognitive processes driving tapping behavior during the test are not well characterized or understood. This lack of understanding may make clinical inferences from test results about health or disease state less accurate because important aspects of the task such as variability or fatigue are unmeasured. To overcome these limitations, we enhanced the tapper with a sensor that enables us to more fully characterize all the aspects of tapping. This modification enabled us to decompose the tapping performance into six component phases and represent each phase with a set of parameters having clear functional interpretation. This results in a set of 29 total parameters for each trial, including change in tapping over time, and trial-to-trial and tap-to-tap variability. These parameters can be used to more precisely link different aspects of cognition or motor function to tapping behavior. We demonstrate the benefits of this new instrument with a simple hypothesis-driven trial comparing single and dual-task tapping.

Modeling the dynamics of recognition memory testing with an integrated model of retrieval and decision making.

PubMed

Osth, Adam F; Jansson, Anna; Dennis, Simon; Heathcote, Andrew

2018-08-01

A robust finding in recognition memory is that performance declines monotonically across test trials. Despite the prevalence of this decline, there is a lack of consensus on the mechanism responsible. Three hypotheses have been put forward: (1) interference is caused by learning of test items (2) the test items cause a shift in the context representation used to cue memory and (3) participants change their speed-accuracy thresholds through the course of testing. We implemented all three possibilities in a combined model of recognition memory and decision making, which inherits the memory retrieval elements of the Osth and Dennis (2015) model and uses the diffusion decision model (DDM: Ratcliff, 1978) to generate choice and response times. We applied the model to four datasets that represent three challenges, the findings that: (1) the number of test items plays a larger role in determining performance than the number of studied items, (2) performance decreases less for strong items than weak items in pure lists but not in mixed lists, and (3) lexical decision trials interspersed between recognition test trials do not increase the rate at which performance declines. Analysis of the model's parameter estimates suggests that item interference plays a weak role in explaining the effects of recognition testing, while context drift plays a very large role. These results are consistent with prior work showing a weak role for item noise in recognition memory and that retrieval is a strong cause of context change in episodic memory. Copyright © 2018 Elsevier Inc. All rights reserved.

The use of real-time ultrasound feedback in teaching abdominal hollowing exercises to healthy subjects.

PubMed

Henry, Sharon M; Westervelt, Karen C

2005-06-01

Randomized controlled trial. To determine if supplementing typical clinical instruction with real-time ultrasound feedback facilitates performance and retention of the abdominal hollowing exercise (AHE). Increasingly clinicians are using real-time ultrasound imaging as a form of feedback when teaching patients trunk stabilization exercises; however, there has been no justification for this practice. Forty-eight subjects were divided randomly into 3 groups that received different types of feedback: group 1 received minimal verbal feedback, group 2 received verbal and palpatory feedback, and group 3 received real-time ultrasound, verbal, and palpatory feedback. If the subject performed 3 consecutive correct AHEs during the initial session, she/he returned for a retention test. The performance of 3 consecutive, correct AHEs was the criterion measure; the number of trials to criterion was also recorded during the initial and retention test sessions. The ability to perform the AHE differed among groups (P<.001). During the initial session, 12.5% of subjects in group 1, 50.0% of subjects in group 2, and 87.5% of subjects in group 3 were able to perform 3 consecutive AHEs. Group 3 subjects achieved the criterion in fewer trials than the other 2 groups (P = .0006). No differences among groups were found for the retention testing; however, low power due to fewer subjects precluded a strong interpretation of this finding. Real-time ultrasound feedback can decrease the number of trials needed to consistently perform the AHE; however, the data are inconclusive with regard to retention of this skill.

Correction of a Technical Error in the Golf Swing: Error Amplification Versus Direct Instruction.

PubMed

Milanese, Chiara; Corte, Stefano; Salvetti, Luca; Cavedon, Valentina; Agostini, Tiziano

2016-01-01

Performance errors drive motor learning for many tasks. The authors' aim was to determine which of two strategies, method of amplification of error (MAE) or direct instruction (DI), would be more beneficial for error correction during a full golfing swing with a driver. Thirty-four golfers were randomly assigned to one of three training conditions (MAE, DI, and control). Participants were tested in a practice session in which each golfer performed 7 pretraining trials, 6 training-intervention trials, and 7 posttraining trials; and a retention test after 1 week. An optoeletronic motion capture system was used to measure the kinematic parameters of each golfer's performance. Results showed that MAE is an effective strategy for correcting the technical errors leading to a rapid improvement in performance. These findings could have practical implications for sport psychology and physical education because, while practice is obviously necessary for improving learning, the efficacy of the learning process is essential in enhancing learners' motivation and sport enjoyment.

Robust inference for group sequential trials.

PubMed

Ganju, Jitendra; Lin, Yunzhi; Zhou, Kefei

2017-03-01

For ethical reasons, group sequential trials were introduced to allow trials to stop early in the event of extreme results. Endpoints in such trials are usually mortality or irreversible morbidity. For a given endpoint, the norm is to use a single test statistic and to use that same statistic for each analysis. This approach is risky because the test statistic has to be specified before the study is unblinded, and there is loss in power if the assumptions that ensure optimality for each analysis are not met. To minimize the risk of moderate to substantial loss in power due to a suboptimal choice of a statistic, a robust method was developed for nonsequential trials. The concept is analogous to diversification of financial investments to minimize risk. The method is based on combining P values from multiple test statistics for formal inference while controlling the type I error rate at its designated value.This article evaluates the performance of 2 P value combining methods for group sequential trials. The emphasis is on time to event trials although results from less complex trials are also included. The gain or loss in power with the combination method relative to a single statistic is asymmetric in its favor. Depending on the power of each individual test, the combination method can give more power than any single test or give power that is closer to the test with the most power. The versatility of the method is that it can combine P values from different test statistics for analysis at different times. The robustness of results suggests that inference from group sequential trials can be strengthened with the use of combined tests. Copyright © 2017 John Wiley & Sons, Ltd.

The effect of clobazam and lorazepam on the psychomotor performance of anxious patients

PubMed Central

Oblowitz, H.; Robins, A. H.

1983-01-01

1 Psychomotor performance and anxiety were measured in 70 anxious outpatients in a randomized double-blind, placebo-controlled trial comparing the 1,5-benzodiazepine clobazam (10 mg twice a day) to lorazepam (1 mg twice a day). Carefully selected tests were administered pre-treatment and at 2 and 9 days after treatment. Compliance was checked by blood assays. 2 All three treatment groups (clobazam, lorazepam and placebo) showed a significant improvement in anxiety over the course of the trial. There were no significant differences between the groups in terms of anxiety reduction. 3 All three groups improved over the course of the trial in choice reaction time, digit symbol substitution test, Purdue pegboard test (both hands) and in the Inglis paired-associate learning test: there were no significant differences between the groups with regard to these tests. There was no change in critical flicker fusion threshold over the trial period in any of the three groups. 4 The placebo and clobazam groups showed a significant improvement in two of the Purdue pegboard tests (preferred hand and assembly) from pre-treatment to 2 days but no further improvement at 9 days. The lorazepam group, however, showed no improvement in these two tests from pre-treatment to 2 days; a significant improvement only emerged between the 2-day and 9-day assessments. This might reflect an initial, transient sedation in the lorazepam-treated patients. 5 Generally, we failed to demonstrate any consistent impairment in psychomotor performance with either clobazam or lorazepam in our anxious patients. These findings contrast with those obtained after administration of 1,4-benzodiazepines (e.g., lorazepam) to normal volunteers and they suggest that data from the latter cannot necessarily be extrapolated to anxious patients. PMID:6136292

20 CFR 220.170 - The trial work period.

Code of Federal Regulations, 2010 CFR

2010-04-01

... a period during which the annuitant may test his or her ability to work and still be considered... period, the annuitant may perform “services” (see paragraph (b) of this section) in as many as 9 months... trial work periods. The annuitant may have only one trial work period during each period in which he or...

Cognitive outcomes after sertaline treatment in patients with depression of Alzheimer disease.

PubMed

Munro, Cynthia A; Longmire, Crystal Flynn; Drye, Lea T; Martin, Barbara K; Frangakis, Constantine E; Meinert, Curtis L; Mintzer, Jacobo E; Porsteinsson, Anton P; Rabins, Peter V; Rosenberg, Paul B; Schneider, Lon S; Weintraub, Daniel; Lyketsos, Constantine G

2012-12-01

Although many depressed patients with Alzheimer disease (AD) are treated with antidepressants, the effect of such treatment on cognitive performance in these patients is not known. The authors report cognitive outcomes in patients with depression of AD (dAD) after a 24-week trial of sertraline or placebo. Placebo-controlled, randomized, double-blind trial. Outpatient memory clinics at five academic medical centers in the United States. A total of 131 patients with dAD (60 men) and Mini-Mental State Examination scores of 10-26. Sertraline (n = 67), target dose of 100 mg daily or matching placebo (n = 64). Caregivers received standardized psychosocial intervention throughout the trial. Mini-Mental State Examination, cognitive subscale of the Alzheimer's Disease Assessment Scale, letter fluency, backward digit span, Symbol Digit Modalities Test, and Finger Tapping Test, administered at baseline, and 8, 16, and 24 weeks following baseline. A series of linear models indicated no effect of treatment or of depression remission on cognitive test performance at 24 weeks. Regardless of treatment condition, very little change in cognitive test performance was noted in general. Treatment with sertraline in patients with dAD is not associated with greater improvement in cognition at week 24 than treatment with placebo.

Is a comparative clinical trial for breast cancer tumor markers to monitor disease recurrence warranted? A value of information analysis

PubMed Central

Thariani, Rahber; Henry, Norah Lynn; Ramsey, Scott D; Blough, David K; Barlow, Bill; Gralow, Julie R; Veenstra, David L

2014-01-01

Background Breast cancer tumor markers are used by some clinicians to screen for disease recurrence risk. Since there is limited evidence of benefit, additional research may be warranted. Aim To assess the potential value of a randomized clinical trial of breast tumor marker testing in routine follow-up of high-risk, stage II–III breast cancer survivors. Materials & methods We developed a decision-analytic model of tumor marker testing plus standard surveillance every 3–6 months for 5 years. The expected value of sample information was calculated using probabilistic simulations and was a function of: the probability of selecting the optimal monitoring strategy with current versus future information; the impact of choosing the nonoptimal strategy; and the size of the population affected. Results The value of information for a randomized clinical trial involving 9000 women was US$214 million compared with a cost of US$30–60 million to conduct such a trial. The probability of making an alternate, nonoptimal decision and choosing testing versus no testing was 32% with current versus future information from the trial. The impact of a nonoptimal decision was US$2150 and size of population impacted over 10 years was 308,000. The value of improved information on overall survival was US$105 million, quality of life US$37 million and test performance US$71 million. Conclusion Conducting a randomized clinical trial of breast cancer tumor markers appears to offer a good societal return on investment. Retrospective analyses to assess test performance and evaluation of patient quality of life using tumor markers may also offer valuable areas of research. However, alternative investments may offer even better returns in investments and, as such, the trial concept deserves further study as part of an overall research-portfolio evaluation. PMID:24236631

Release from proactive interference in rat spatial working memory.

PubMed

Roberts, William A; MacDonald, Hayden; Brown, Lyn; Macpherson, Krista

2017-09-01

A three-phase procedure was used to produce proactive interference (PI) in one trial on an eight-arm radial maze. Rats were forced to enter four arms for reward on an initial interference phase, to then enter the four remaining arms on a target phase, and to then choose among all eight arms on a retention test, with only the arms not visited in the target phase containing reward. Control trials involved only the target phase and the retention test. Lower accuracy was found on PI trials than on control trials, but performance on PI trials significantly exceeded chance, showing some retention of target memories. Changes in temporal and reward variables between the interference, target, and retention test phases showed release from PI, but changes in context and pattern of arm entry did not. It is suggested that the release from PI paradigm can be used to understand spatial memory encoding in rats and other species.

Testing homogeneity of proportion ratios for stratified correlated bilateral data in two-arm randomized clinical trials.

PubMed

Pei, Yanbo; Tian, Guo-Liang; Tang, Man-Lai

2014-11-10

Stratified data analysis is an important research topic in many biomedical studies and clinical trials. In this article, we develop five test statistics for testing the homogeneity of proportion ratios for stratified correlated bilateral binary data based on an equal correlation model assumption. Bootstrap procedures based on these test statistics are also considered. To evaluate the performance of these statistics and procedures, we conduct Monte Carlo simulations to study their empirical sizes and powers under various scenarios. Our results suggest that the procedure based on score statistic performs well generally and is highly recommended. When the sample size is large, procedures based on the commonly used weighted least square estimate and logarithmic transformation with Mantel-Haenszel estimate are recommended as they do not involve any computation of maximum likelihood estimates requiring iterative algorithms. We also derive approximate sample size formulas based on the recommended test procedures. Finally, we apply the proposed methods to analyze a multi-center randomized clinical trial for scleroderma patients. Copyright © 2014 John Wiley & Sons, Ltd.

Impact on learning of an e-learning module on leukaemia: a randomised controlled trial

PubMed Central

2012-01-01

Background e-learning resources may be beneficial for complex or conceptually difficult topics. Leukaemia is one such topic, yet there are no reports on the efficacy of e-learning for leukaemia. This study compared the learning impact on senior medical students of a purpose-built e-learning module on leukaemia, compared with existing online resources. Methods A randomised controlled trial was performed utilising volunteer senior medical students. Participants were randomly allocated to Study and Control groups. Following a pre-test on leukaemia administered to both groups, the Study group was provided with access to the new e-learning module, while the Control group was directed to existing online resources. A post-test and an evaluation questionnaire were administered to both groups at the end of the trial period. Results Study and Control groups were equivalent in gender distribution, mean academic ability, pre-test performance and time studying leukaemia during the trial. The Study group performed significantly better than the Control group in the post-test, in which the group to which the students had been allocated was the only significant predictor of performance. The Study group’s evaluation of the module was overwhelmingly positive. Conclusions A targeted e-learning module on leukaemia had a significant effect on learning in this cohort, compared with existing online resources. We believe that the interactivity, dialogic feedback and integration with the curriculum offered by the e-learning module contributed to its impact. This has implications for e-learning design in medicine and other disciplines. PMID:22640463

Effects of a soybean nutrition bar on the postprandial blood glucose and lipid levels in patients with diabetes mellitus.

PubMed

Urita, Yoshihisa; Noda, Tsuneyuki; Watanabe, Daisuke; Iwashita, Soh; Hamada, Koichiro; Sugimoto, Motonobu

2012-12-01

We investigated the influence of a soybean nutrition bar made from whole soy powder on the blood glucose, insulin and lipid levels in comparison with a test cookie with the same amount of energy in patients with diabetes mellitus. In the cross-over designed study, meal tolerance tests using the soybean nutrition bar and test cookie were performed. Two kinds of test meals were used: Study 1 80 kcal, Study 2 592 kcal. The blood glucose response was significantly lower in the soybean nutrition bar trial than in the cookie trial (Studies 1 and 2, p < 0.001). The blood insulin response was also significantly lower in the soybean nutrition bar trial than in the cookie trial (Study 2, p < 0.001). The blood triglyceride and non-esterified fatty acid responses were not significantly different between the two trials, nor were the changes in breath H₂ enrichment (Study 2). The soybean nutrition bar did not induce postprandial hyperglycaemia in diabetic patients unlike the isoenergetic test cookies.

Drug-device trials for infectious diseases: CDRH perspective.

PubMed

Meier, Kristen L; Gitterman, Steven

2011-05-01

Assessing the performance of new diagnostic tests for infectious diseases has traditionally focused on comparing the new assay against a reference standard such as culture. In this paper, we suggest that clinical trial designs with both a diagnostic and therapeutic component may be necessary to evaluate the safety and effectiveness of nonmicrobiologically based assays, with a specific emphasis on the test/marker-stratified design. General design challenges for trials of infectious diseases that simultaneously study both diagnostic and therapeutic components (eg, both devices and drugs) are also discussed.

The Bay Area Verbal Learning Test (BAVLT): Normative Data and the Effects of Repeated Testing, Simulated Malingering, and Traumatic Brain Injury

PubMed Central

Woods, David L.; Wyma, John M.; Herron, Timothy J.; Yund, E. William

2017-01-01

Verbal learning tests (VLTs) are widely used to evaluate memory deficits in neuropsychiatric and developmental disorders. However, their validity has been called into question by studies showing significant differences in VLT scores obtained by different examiners. Here we describe the computerized Bay Area Verbal Learning Test (BAVLT), which minimizes inter-examiner differences by incorporating digital list presentation and automated scoring. In the 10-min BAVLT, a 12-word list is presented on three acquisition trials, followed by a distractor list, immediate recall of the first list, and, after a 30-min delay, delayed recall and recognition. In Experiment 1, we analyzed the performance of 195 participants ranging in age from 18 to 82 years. Acquisition trials showed strong primacy and recency effects, with scores improving over repetitions, particularly for mid-list words. Inter-word intervals (IWIs) increased with successive words recalled. Omnibus scores (summed over all trials except recognition) were influenced by age, education, and sex (women outperformed men). In Experiment 2, we examined BAVLT test-retest reliability in 29 participants tested with different word lists at weekly intervals. High intraclass correlation coefficients were seen for omnibus and acquisition scores, IWIs, and a categorization index reflecting semantic reorganization. Experiment 3 examined the performance of Experiment 2 participants when feigning symptoms of traumatic brain injury. Although 37% of simulated malingerers showed abnormal (p < 0.05) omnibus z-scores, z-score cutoffs were ineffective in discriminating abnormal malingerers from control participants with abnormal scores. In contrast, four malingering indices (recognition scores, primacy/recency effects, learning rate across acquisition trials, and IWIs) discriminated the two groups with 80% sensitivity and 80% specificity. Experiment 4 examined the performance of a small group of patients with mild or severe TBI. Overall, both patient groups performed within the normal range, although significant performance deficits were seen in some patients. The BAVLT improves the speed and replicability of verbal learning assessments while providing comprehensive measures of retrieval timing, semantic organization, and primacy/recency effects that clarify the nature of performance. PMID:28127280

Long-term retention of a divided attention psycho-motor test combining choice reaction test and postural balance test: A preliminary study.

PubMed

Rossi, R; Pascolo, P B

2015-09-01

Driving in degraded psychophysical conditions, such as under the influence of alcohol or drugs but also in a state of fatigue or drowsiness, is a growing problem. The current roadside tests used for detecting drugs from drivers suffer various limitations, while impairment is subjective and does not necessarily correlate with drug metabolite concentration found in body fluids. This work is a validation step towards the study of feasibility of a novel test conceived to assess psychophysical conditions of individuals performing at-risk activities. Motor gestures, long-term retention and learning phase related to the protocol are analysed in unimpaired subjects. The protocol is a divided attention test, which combines a critical tracking test achieved with postural movements and a visual choice reaction test. Ten healthy subjects participated in a first set of trials and in a second set after about six months. Each session required the carrying out of the test for ten times in order to investigate learning effect and performance over repetitions. In the first set the subjects showed a learning trend up to the third trial, whilst in the second set of trials they showed motor retention. Nevertheless, the overall performance did not significantly improve. Gestures are probably retained due to the type of tasks and the way in which the instructions are conveyed to the subjects. Moreover, motor retention after a short training suggests that the protocol is easy to learn and understand. Implications for roadside test usage and comparison with current tests are also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Testing of Badminton-Specific Endurance.

PubMed

Madsen, Christian M; Højlyng, Mads; Nybo, Lars

2016-09-01

Madsen, CM, Højlyng, M, and Nybo, L. Testing of badminton-specific endurance. J Strength Cond Res 30(9): 2582-2590, 2016-In the present study, a novel intermittent badminton endurance (B-ENDURANCE) test was developed and tested in elite (n = 17) and skilled (n = 9) badminton players and in age-matched physically active men (nonbadminton players; n = 8). In addition, B-ENDURANCE test-retest reproducibility was evaluated in 9 badminton players. The B-ENDURANCE test is an incremental test where each level consists of repeated sequences of badminton-specific actions toward the 4 corners of the court. The subject starts in the center of the court in front of a computer screen and within each sequence, he must, in a randomized order, complete 8 actions as dictated by the computer, providing the audiovisual input and verifying that the appropriate sensor is activated within the allocated time. Recovery time between each sequence is 10 seconds throughout the test, but the time to complete each sequence is gradually decreased until the subjects cannot follow the dictated tempo. The B-ENDURANCE test performance for elite players was better (p ≤ 0.05) compared with the skilled players and nonbadminton players. In addition, the B-ENDURANCE test performance correlated (r = 0.8 and p < 0.0001) with elite players' national single rankings. Test-retest coefficient of variation was 7.9% between the first 2 trials (i.e., without a familiarization trial) but reduced to 2.5% when comparing the second and third trials. In conclusion, the B-ENDURANCE test is relevant for the evaluation of badminton-specific endurance but at least 1 familiarization trial is recommended if the test is used for evaluation of longitudinal changes, e.g., tracking training effects.

The Robinson Protocol: a treadmill anaerobic performance test.

PubMed

Robinson, Ellyn M; Graham, Louise B; Headley, Samuel A

2004-08-01

The current investigation was designed to further examine the reliability of the Robinson protocol, which is a run-to-exhaustion treadmill test. Robinson (10) originally examined this protocol with 5 subjects. The significance of the initial exploratory study was the impetus for expanding the study to examine the reliability of the protocol with a larger sample. Fifteen male subjects participated in 3 trial runs on the treadmill. The first trial was a modified McConnell (7) test to determine the aerobic capacity of each subject. The second and third trials were identical Robinson protocols (10). The first trial run mean, in seconds (262.04 +/- 74.50), was not significantly different from the second trial run mean (257.30 +/- 72.65), p = 0.526 (2 tailed). As expected, trial 1 and trial 2 were highly correlated (intraclass) (r = 0.927, p < 0.001). These results provide additional support for the hypothesis that the Robinson protocol with a greater subject pool is a reliable protocol that can be used in research studies interested in examining various physiological interventions or anaerobic training.

Clinical trials of homoeopathy.

PubMed Central

Kleijnen, J; Knipschild, P; ter Riet, G

1991-01-01

OBJECTIVE--To establish whether there is evidence of the efficacy of homoeopathy from controlled trials in humans. DESIGN--Criteria based meta-analysis. Assessment of the methodological quality of 107 controlled trials in 96 published reports found after an extensive search. Trials were scored using a list of predefined criteria of good methodology, and the outcome of the trials was interpreted in relation to their quality. SETTING--Controlled trials published world wide. MAIN OUTCOME MEASURES--Results of the trials with the best methodological quality. Trials of classical homoeopathy and several modern varieties were considered separately. RESULTS--In 14 trials some form of classical homoeopathy was tested and in 58 trials the same single homoeopathic treatment was given to patients with comparable conventional diagnosis. Combinations of several homoeopathic treatments were tested in 26 trials; isopathy was tested in nine trials. Most trials seemed to be of very low quality, but there were many exceptions. The results showed a positive trend regardless of the quality of the trial or the variety of homeopathy used. Overall, of the 105 trials with interpretable results, 81 trials indicated positive results whereas in 24 trials no positive effects of homoeopathy were found. The results of the review may be complicated by publication bias, especially in such a controversial subject as homoeopathy. CONCLUSIONS--At the moment the evidence of clinical trials is positive but not sufficient to draw definitive conclusions because most trials are of low methodological quality and because of the unknown role of publication bias. This indicates that there is a legitimate case for further evaluation of homoeopathy, but only by means of well performed trials. PMID:1825800

Repeat testing of low-level HIV-1 RNA: assay performance and implementation in clinical trials.

PubMed

White, Kirsten; Garner, Will; Wei, Lilian; Eron, Joseph J; Zhong, Lijie; Miller, Michael D; Martin, Hal; Plummer, Andrew; Tran-Muchowski, Cecilia; Lindstrom, Kim; Porter, James; Piontkowsky, David; Light, Angela; Reiske, Heinz; Quirk, Erin

2018-05-15

Assess the performance of HIV-1 RNA repeat testing of stored samples in cases of low-level viremia during clinical trials. Prospective and retrospective analysis of randomized clinical trial samples and reference standards. To evaluate assay variability of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Test, v2.0, three separate sources of samples were utilized: the World Health Organization (WHO) HIV reference standard (assayed using 50 independent measurements at six viral loads <200 copies/ml), retrospective analysis of four to six aliquots of plasma samples from four clinical trial participants, and prospective repeat testing of 120 samples from participants in randomized trials with low-level viremia. The TaqMan assay on the WHO HIV-1 RNA standards at viral loads <200 copies/ml performed within the expected variability according to assay specifications. However, standards with low viral loads of 36 and 18 copies/ml reported values of ≥ 50 copies/ml in 66 and 18% of tests, respectively. In participants treated with antiretrovirals who had unexpected viremia of 50-200 copies/ml after achieving <50 copies/ml, retesting of multiple aliquots of stored plasma found <50 copies/ml in nearly all cases upon retesting (14/15; 93%). Repeat testing was prospectively implemented in four clinical trials for all samples with virologic rebound of 50-200 copies/ml (n = 120 samples from 92 participants) from which 42% (50/120) had a retest result of less than 50 copies/ml and 58% (70/120) retested ≥ 50 copies/ml. The TaqMan HIV-1 RNA assay shows variability around 50 copies/ml that affects clinical trial results and may impact clinical practice. In participants with a history of viral load suppression, unexpected low-level viremia may be because of assay variability rather than low drug adherence or true virologic failure. Retesting a stored aliquot of the same sample may differentiate between assay variability and virologic failure as the source of viremia. This retesting strategy could save time, money, and anxiety for patients and their providers, as well as decrease follow-up clinic visits without increasing the risk of virologic failure and resistance development.

Performance of Healthy Braced Participants During Aerobic and Anaerobic Capacity Tasks

PubMed Central

Rishiraj, Neetu; Taunton, Jack E.; Niven, Brian; Lloyd-Smith, Robert; Regan, William; Woollard, Robert

2011-01-01

Context: Knee braces were introduced in sports approximately 30 years ago. However, the effects of a functional knee brace (FKB) on aerobic and anaerobic performance after fatigue are unknown. Objective: To investigate whether FKB use in noninjured participants hindered performance during aerobic (Léger beep test) and anaerobic (repeated high-intensity shuttle test [RHIST]) tasks. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Twenty-seven healthy male provincial and national basketball and field hockey athletes (age = 19.4 ± 3.0 years, range, 17–26 years; height = 182.6 ± 6.8 cm, range, 168–196 cm; mass = 80.0 ± 9.1 kg, range, 66–108 kg). Interventions : Each participant was provided a custom-fitted FKB and performed 5 nonbraced (NBR) testing sessions over 3 days, followed by 5 braced (BR) testing sessions over 3 days, for a total of 17.5 hours of testing per condition. During each testing session, participants performed 1 trial of the Léger beep test and 1 trial of the RHIST in each condition. Main Outcome Measure(s): Predicted maximal oxygen consumption (V˙o2max) and time performance measures were recorded for each NBR and BR trial. Results: Initial performance levels were lower for BR than NBR for both the Léger beep test (BR = 44.3 mL/kg/min, NBR = 47.3 mL/kg/min; F1,26 = 8.726; P = .007) and the RHIST (BR = 16.5 seconds, NBR = 16.2 seconds; F1,26 = 13.98, P = .001). However, with continued FKB use, the aerobic performance measure remained higher for only the first 2 BR testing sessions (NBR = 46.9 mL/kg/min, BR = 42.4 mL/kg/min; F3.0,79.8 = 4.95, P = .003). For the anaerobic test, no performance difference was noted between the testing conditions (NBR = 16.2 seconds, BR = 16.4 seconds; P = .7), whereas fatigue levels were lower during BR testing sessions (NBR = 33%, BR = 31%). After 14.0 hours of FKB use, performance levels were almost equal between the testing conditions (NBR = 47.6 mL/kg/min, BR = 46.1 mL/kg/min). Conclusions: We found an initial decrement in performance when the FKB was used during an aerobic or anaerobic task. However, after 14.0 hours of FKB use, accommodation to the FKB was possible. PMID:21944071

The use of a battery of tracking tests in the quantitative evaluation of neurological function

NASA Technical Reports Server (NTRS)

Repa, B. S.; Albers, J. W.; Potvin, A. R.; Tourtellotte, W. W.

1972-01-01

A tracking test battery has been applied in a drug trail designed to compare the efficacy of L-DOPA and amantadine to that of L-DOPA and placebo in the treatment of 28 patients with Parkinson's disease. The drug trial provided an ideal opportunity for objectively evaluating the usefulness of tracking tests in assessing changes in neurologic function. Evaluating changes in patient performance resulting from disease progression and controlled clinical trials is of great importance in establishing effective treatment programs.

Data-driven methodology illustrating mechanisms underlying word list recall: applications to clinical research.

PubMed

Longenecker, Julia; Kohn, Philip; Liu, Stanley; Zoltick, Brad; Weinberger, Daniel R; Elvevåg, Brita

2010-09-01

Word list learning tasks such as the California Verbal Learning Test (CVLT; Delis, Kramer, Kaplan, & Ober, 1987) are widely used to investigate recall strategies. Participants who recall the most words generally employ semantic techniques, whereas those with poor recall (e.g., patients with schizophrenia) rely on serial techniques. However, these conclusions are based on formulas that assume that categories reflect semantic associations, bind strategy to overall performance, and neglect strategy changes over 5 trials. Therefore, we derived novel measures-independent of recall performance-to compute strategies across trials and identify whether diagnosis predicts recall strategy. Participants were included on the basis of performance on the CVLT (i.e., total words recalled over 5 trials). The 50 highest and 50 lowest performers among healthy volunteers (n = 100) and patients with schizophrenia (n = 100) were selected. Novel measures of recall and transition probability were calculated and analyzed by permutation tests. Recall patterns and strategies of patients resembled those of controls with similar performance levels: Regardless of diagnosis, low performers were more likely to recall the first 2 and last 4 items from the list; high performers increased engagement of semantically based transitions across the 5 trials, whereas low performers did not. Cognitive strategy must be considered independent of overall performance before attributing poor performance to degraded learning processes. Our results demonstrate the importance of departing from global scoring techniques, especially when working with clinical populations such as patients with schizophrenia for whom episodic memory deficits are a hallmark feature. Copyright 2010 APA, all rights reserved.

Weighted re-randomization tests for minimization with unbalanced allocation.

PubMed

Han, Baoguang; Yu, Menggang; McEntegart, Damian

2013-01-01

Re-randomization test has been considered as a robust alternative to the traditional population model-based methods for analyzing randomized clinical trials. This is especially so when the clinical trials are randomized according to minimization, which is a popular covariate-adaptive randomization method for ensuring balance among prognostic factors. Among various re-randomization tests, fixed-entry-order re-randomization is advocated as an effective strategy when a temporal trend is suspected. Yet when the minimization is applied to trials with unequal allocation, fixed-entry-order re-randomization test is biased and thus compromised in power. We find that the bias is due to non-uniform re-allocation probabilities incurred by the re-randomization in this case. We therefore propose a weighted fixed-entry-order re-randomization test to overcome the bias. The performance of the new test was investigated in simulation studies that mimic the settings of a real clinical trial. The weighted re-randomization test was found to work well in the scenarios investigated including the presence of a strong temporal trend. Copyright © 2013 John Wiley & Sons, Ltd.

The bimanual ovarian palpation examination in the Prostate, Lung, Colorectal and Ovarian cancer screening trial: Performance and complications.

PubMed

Doroudi, Maryam; Kramer, Barnett S; Pinsky, Paul F

2017-12-01

Objective To provide evidence about the performance characteristics and consequences of bimanual ovarian palpation. Setting and methods The Prostate, Lung, Colorectal and Ovarian cancer screening trial randomized 154,900 individuals to either an intervention or control arm. Enrolled eligible participants were aged 55-74, had no history of trial cancers, and no current treatment for cancer. Intervention arm women received CA-125 tests and transvaginal ultrasound. Bimanual ovarian palpation was offered annually during the first four years of the trial. Bimanual ovarian palpation-specific sensitivity and specificity were calculated, as were rates of diagnostic procedures and resulting complications following positive bimanual ovarian palpation screens. Results A total of 20,872 women received at least one bimanual ovarian palpation, with 50,498 total bimanual ovarian palpation examinations performed. The sensitivity and specificity of bimanual ovarian palpation were 5.1% (2/39) and 99.0% (49,957/50,459), respectively; no cases were detected by bimanual ovarian palpation alone. Rates for most follow-up procedures for abnormal results in women without ovarian cancer were higher among the group with another screening test positive, except for pelvic exam, where rates were similar. No complications were reported in the bimanual ovarian palpation-only positive group. Conclusion Low sensitivity of bimanual ovarian palpation alone and in combination with other tests argue against using bimanual ovarian palpation as a screening test for ovarian cancer in asymptomatic women.

In vitro testing to diagnose venom allergy and monitor immunotherapy: a placebo-controlled, crossover trial.

PubMed

Brown, S G A; Haas, M A; Black, J A; Parameswaran, A; Woods, G M; Heddle, R J

2004-05-01

In people with a history of sting allergy, only prior reaction severity and older age are known to predict subsequent reaction risk. Furthermore, no diagnostic test other than a deliberate sting challenge has been found to identify people in whom venom immunotherapy (VIT) has been unsuccessful. We aimed to assess the utility of a number of in vitro tests to diagnose venom allergy and to monitor immunotherapy. During a double-blind randomized placebo-controlled crossover trial of Myrmecia pilosula ant VIT the following venom-specific tests were performed at enrolment, and at completion of treatment prior to a diagnostic sting challenge; leucocyte stimulation index (SI), IL-4 production, IgE RAST, histamine release test (HRT), leukotriene release test (LRT) and basophil activation test (BAT). Intradermal venom skin testing (VST) was also performed at trial entry. Only VST and HRT identified those at risk of sting anaphylaxis in the placebo group. Although IgE RAST, leucocyte SI and IL-4 production, LRT and BAT all correlated well with intradermal VSTs, they did not predict sting challenge outcome. After successful VIT, venom-induced leucocyte IL-4 production tended to fall, whereas IgE RAST increased and a natural decline in HRT reactivity was reversed. A confounding seasonal affect on laboratory results was suspected. The HRT warrants further assessment for diagnosis of venom allergy. Uninformative performance of the commercially available LRT and BAT tests may be due to pre-incubation with IL-3. None of the tests evaluated appear to be reliable markers of successful VIT.

Interactions between the concentration of non-starch polysaccharides in wheat and the addition of an enzyme mixture in a broiler digestibility and performance trial.

PubMed

Smeets, N; Nuyens, F; Van Campenhout, L; Delezie, E; Niewold, T A

2018-06-01

Two broiler trials were designed to investigate the relationship between the concentration of non-starch polysaccharides (NSP) in wheat and 1) its nutritional value for broilers and 2) the efficacy of exogenous enzymes. In a balance trial, diets were formulated with 3 wheat cultivars (Rustic and Viscount-medium NSP, Centenaire-high NSP) and were tested with or without the addition of an exogenous enzyme mixture. The diets were fed to 144 male Ross 308 broiler chickens housed in digestibility cages. Total tract nutrient digestibilities and AMEn were measured from 18 to 22 d of age. In a performance trial, diets were formulated with wheat (medium NSP diet) or with wheat mixed with rye and barley (high NSP diet) and were tested with or without the addition of an exogenous enzyme mixture. The diets were fed to 960 male Ross 308 broilers housed in pens and broiler performance during starter, grower and finisher periods was measured.In the balance trial, wheat cultivar did not affect nutrient digestibility or AMEn. Enzyme addition caused a significant increase in nutrient digestibilities and AMEn for the diet formulated with the high NSP wheat Centenaire only. In the performance trial, feeding the high NSP diet resulted in a higher feed conversion ratio and lower final body weight compared to the medium NSP diet. The largest improvements by enzyme addition were observed in the high NSP diet.In conclusion, the study was not able to show a consistent relationship between the NSP concentration of wheat and its nutritional value, but did demonstrate that the effect of an enzyme mixture on nutrient digestibility or broiler performance depends upon the NSP concentration in the diet.

Interactions between the concentration of non-starch polysaccharides in wheat and the addition of an enzyme mixture in a broiler digestibility and performance trial

PubMed Central

Smeets, N; Nuyens, F; Van Campenhout, L; Delezie, E; Niewold, T A

2018-01-01

ABSTRACT Two broiler trials were designed to investigate the relationship between the concentration of non-starch polysaccharides (NSP) in wheat and 1) its nutritional value for broilers and 2) the efficacy of exogenous enzymes. In a balance trial, diets were formulated with 3 wheat cultivars (Rustic and Viscount—medium NSP, Centenaire—high NSP) and were tested with or without the addition of an exogenous enzyme mixture. The diets were fed to 144 male Ross 308 broiler chickens housed in digestibility cages. Total tract nutrient digestibilities and AMEn were measured from 18 to 22 d of age. In a performance trial, diets were formulated with wheat (medium NSP diet) or with wheat mixed with rye and barley (high NSP diet) and were tested with or without the addition of an exogenous enzyme mixture. The diets were fed to 960 male Ross 308 broilers housed in pens and broiler performance during starter, grower and finisher periods was measured. In the balance trial, wheat cultivar did not affect nutrient digestibility or AMEn. Enzyme addition caused a significant increase in nutrient digestibilities and AMEn for the diet formulated with the high NSP wheat Centenaire only. In the performance trial, feeding the high NSP diet resulted in a higher feed conversion ratio and lower final body weight compared to the medium NSP diet. The largest improvements by enzyme addition were observed in the high NSP diet. In conclusion, the study was not able to show a consistent relationship between the NSP concentration of wheat and its nutritional value, but did demonstrate that the effect of an enzyme mixture on nutrient digestibility or broiler performance depends upon the NSP concentration in the diet. PMID:29471412

Thermo-mechanical evaluation of carbon-carbon primary structure for SSTO vehicles

NASA Astrophysics Data System (ADS)

Croop, Harold C.; Lowndes, Holland B.; Hahn, Steven E.; Barthel, Chris A.

1998-01-01

An advanced development program to demonstrate carbon-carbon composite structure for use as primary load carrying structure has entered the experimental validation phase. The component being evaluated is a wing torque box section for a single-stage-to-orbit (SSTO) vehicle. The validation or demonstration component features an advanced carbon-carbon design incorporating 3D woven graphite preforms, integral spars, oxidation inhibited matrix, chemical vapor deposited (CVD) oxidation protection coating, and ceramic matrix composite fasteners. The validation component represents the culmination of a four phase design and fabrication development effort. Extensive developmental testing was performed to verify material properties and integrity of basic design features before committing to fabrication of the full scale box. The wing box component is now being set up for testing in the Air Force Research Laboratory Structural Test Facility at Wright-Patterson Air Force Base, Ohio. One of the important developmental tests performed in support of the design and planned testing of the full scale box was the fabrication and test of a skin/spar trial subcomponent. The trial subcomponent incorporated critical features of the full scale wing box design. This paper discusses the results of the trial subcomponent test which served as a pathfinder for the upcoming full scale box test.

A Randomized Pilot Trial of Remote Ischemic Preconditioning in Heart Failure with Reduced Ejection Fraction

PubMed Central

McDonald, Michael A.; Braga, Juarez R.; Li, Jing; Manlhiot, Cedric; Ross, Heather J.; Redington, Andrew N.

2014-01-01

Background Remote ischemic preconditioning (RIPC) induced by transient limb ischemia confers multi-organ protection and improves exercise performance in the setting of tissue hypoxia. We aimed to evaluate the effect of RIPC on exercise capacity in heart failure patients. Methods We performed a randomized crossover trial of RIPC (4×5-minutes limb ischemia) compared to sham control in heart failure patients undergoing exercise testing. Patients were randomly allocated to either RIPC or sham prior to exercise, then crossed over and completed the alternate intervention with repeat testing. The primary outcome was peak VO2, RIPC versus sham. A mechanistic substudy was performed using dialysate from study patient blood samples obtained after sham and RIPC. This dialysate was used to test for a protective effect of RIPC in a mouse heart Langendorff model of infarction. Mouse heart infarct size with RIPC or sham dialysate exposure was also compared with historical control data. Results Twenty patients completed the study. RIPC was not associated with improvements in peak VO2 (15.6+/−4.2 vs 15.3+/−4.6 mL/kg/min; p = 0.53, sham and RIPC, respectively). In our Langendorff sub-study, infarct size was similar between RIPC and sham dialysate groups from our study patients, but was smaller than expected compared to healthy controls (29.0%, 27.9% [sham, RIPC] vs 51.2% [controls]. We observed less preconditioning among the subgroup of patients with increased exercise performance following RIPC (p<0.04). Conclusion In this pilot study of RIPC in heart failure patients, RIPC was not associated with improvements in exercise capacity overall. However, the degree of effect of RIPC may be inversely related to the degree of baseline preconditioning. These data provide the basis for a larger randomized trial to test the potential benefits of RIPC in patients with heart failure. Trial Registration ClinicalTrials.gov +++++NCT01128790 PMID:25181050

Educational interventions to improve screening mammography interpretation: a randomized, controlled trial

PubMed Central

BM, Geller; A, Bogart; PA, Carney; EA, Sickles; RA, Smith; B, Monsees; LW, Bassett; DM, Buist; K, Kerlikowske; T, Onega; B, Yankaskas; S, Haneuse; DA, Hill; M, Wallis; DL, Miglioretti

2014-01-01

Purpose Conduct a randomized controlled trial of educational interventions to improve performance of screening mammography interpretation. Materials and Methods We randomly assigned physicians who interpret mammography to one of three groups: (1) self-paced DVD; (2) live, expert-led educational session; or (3) control. The DVD and live interventions used mammography cases of varying difficulty and associated teaching points. Interpretive performance was compared using a pre-/post-test design. Sensitivity, specificity, and positive predictive value (PPV) were calculated relative to two outcomes: cancer status and consensus of three experts about recall, and each were compared using logistic regression adjusting for pre-test performance. Results 102 radiologists completed all aspects of the trial. After adjustment for pre-intervention performance, the odds of improved sensitivity for correctly identifying a lesion relative to expert recall were 1.34 times higher for DVD participants than controls (95% confidence interval [CI]: 1.00, 1.81; P=0.050). The odds of improved PPV for correctly identifying a lesion relative to both expert recall (odds ratio [OR]=1.94, 95% CI: 1.24, 3.05; P=0.004) and cancer status (OR=1.81, 95% CI: 1.01, 3.23; P=0.045) were significantly improved for DVD participants compared to controls with no significant change in specificity. For the live-intervention group, specificity was significantly lower than the control group (OR relative to expert recall=0.80; 95% CI: 0.64, 1.00; P=0.048; OR relative to cancer=0.79; 95% CI: 0.65, 0.95; P=0.015). Conclusion In this randomized controlled trial, the DVD educational intervention resulted in a significant improvement in mammography interpretive screening performance on a test-set, which could translate into improved clinical interpretative performance. PMID:24848854

Specific inspiratory muscle warm-up enhances badminton footwork performance.

PubMed

Lin, Hua; Tong, Tom Kwokkeung; Huang, Chuanye; Nie, Jinlei; Lu, Kui; Quach, Binh

2007-12-01

The effects of inspiratory muscle (IM) warm-up on IM function and on the maximum distance covered in a subsequent incremental badminton-footwork test (FWmax) were examined. Ten male badminton players were recruited to perform identical tests in three different trials in a random order. The control trial did not involve an IM warm-up, whereas the placebo and experimental trials did involve an IM warm-up consisting of two sets of 30-breath manoeuvres with an inspiratory pressure-threshold load equivalent to 15% (PLA) and 40% (IMW) maximum inspiratory mouth pressure, respectively. In the IMW trial, IM function was improved with 7.8%+/-4.0% and 6.9%+/-3.5% increases from control found in maximal inspiratory pressure at zero flow (P0) and maximal rate of P0 development (MRPD), respectively (p<0.05). FWmax was enhanced 6.8%+/-3.7%, whereas the slope of the linear relationship of the increase in the rating of perceived breathlessness for every minute (RPB/min) was reduced (p<0.05). Reduction in blood lactate ([La-]b) accumulation was observed when the test duration was identical to that of the control trial (P<0.05). In the PLA trial, no parameter was changed from control. For the changes (Delta) in parameters in IMW (n=10), negative correlations were found between DeltaP0 and DeltaRPB/min (r2=0.58), DeltaMRPD and DeltaRPB/min (r2=0.48), DeltaRPB/min, and DeltaFWmax (r2=0.55), but not between Delta[La-]b accumulation and DeltaFWmax. Such findings suggest that the IM-specific warm-up improved footwork performance in the subsequent maximum incremental badminton-footwork test. The improved footwork was partly attributable to the reduced breathless sensation resulting from the enhanced IM function, whereas the contribution of the concomitant reduction in [La-]b accumulation was relatively minor.

Discrimination performance in aging is vulnerable to interference and dissociable from spatial memory

PubMed Central

Johnson, Sarah A.; Sacks, Patricia K.; Turner, Sean M.; Gaynor, Leslie S.; Ormerod, Brandi K.; Maurer, Andrew P.; Bizon, Jennifer L.

2016-01-01

Hippocampal-dependent episodic memory and stimulus discrimination abilities are both compromised in the elderly. The reduced capacity to discriminate between similar stimuli likely contributes to multiple aspects of age-related cognitive impairment; however, the association of these behaviors within individuals has never been examined in an animal model. In the present study, young and aged F344×BN F1 hybrid rats were cross-characterized on the Morris water maze test of spatial memory and a dentate gyrus-dependent match-to-position test of spatial discrimination ability. Aged rats showed overall impairments relative to young in spatial learning and memory on the water maze task. Although young and aged learned to apply a match-to-position response strategy in performing easy spatial discriminations within a similar number of trials, a majority of aged rats were impaired relative to young in performing difficult spatial discriminations on subsequent tests. Moreover, all aged rats were susceptible to cumulative interference during spatial discrimination tests, such that error rate increased on later trials of test sessions. These data suggest that when faced with difficult discriminations, the aged rats were less able to distinguish current goal locations from those of previous trials. Increasing acetylcholine levels with donepezil did not improve aged rats’ abilities to accurately perform difficult spatial discriminations or reduce their susceptibility to interference. Interestingly, better spatial memory abilities were not significantly associated with higher performance on difficult spatial discriminations. This observation, along with the finding that aged rats made more errors under conditions in which interference was high, suggests that match-to-position spatial discrimination performance may rely on extra-hippocampal structures such as the prefrontal cortex, in addition to the dentate gyrus. PMID:27317194

Memory for Items and Relationships among Items Embedded in Realistic Scenes: Disproportionate Relational Memory Impairments in Amnesia

PubMed Central

Hannula, Deborah E.; Tranel, Daniel; Allen, John S.; Kirchhoff, Brenda A.; Nickel, Allison E.; Cohen, Neal J.

2014-01-01

Objective The objective of this study was to examine the dependence of item memory and relational memory on medial temporal lobe (MTL) structures. Patients with amnesia, who either had extensive MTL damage or damage that was relatively restricted to the hippocampus, were tested, as was a matched comparison group. Disproportionate relational memory impairments were predicted for both patient groups, and those with extensive MTL damage were also expected to have impaired item memory. Method Participants studied scenes, and were tested with interleaved two-alternative forced-choice probe trials. Probe trials were either presented immediately after the corresponding study trial (lag 1), five trials later (lag 5), or nine trials later (lag 9) and consisted of the studied scene along with a manipulated version of that scene in which one item was replaced with a different exemplar (item memory test) or was moved to a new location (relational memory test). Participants were to identify the exact match of the studied scene. Results As predicted, patients were disproportionately impaired on the test of relational memory. Item memory performance was marginally poorer among patients with extensive MTL damage, but both groups were impaired relative to matched comparison participants. Impaired performance was evident at all lags, including the shortest possible lag (lag 1). Conclusions The results are consistent with the proposed role of the hippocampus in relational memory binding and representation, even at short delays, and suggest that the hippocampus may also contribute to successful item memory when items are embedded in complex scenes. PMID:25068665

Dispersion of Response Times Reveals Cognitive Dynamics

ERIC Educational Resources Information Center

Holden, John G.; Van Orden, Guy C.; Turvey, Michael T.

2009-01-01

Trial-to-trial variation in word-pronunciation times exhibits 1/f scaling. One explanation is that human performances are consequent on multiplicative interactions among interdependent processes-interaction dominant dynamics. This article describes simulated distributions of pronunciation times in a further test for multiplicative interactions and…

The influence of industry sponsorship on the reporting of subgroup analyses within phase III randomised controlled trials in gastrointestinal oncology.

PubMed

Barton, Sarah; Peckitt, Clare; Sclafani, Francesco; Cunningham, David; Chau, Ian

2015-12-01

Correct interpretation of subgroup analyses (SGA) is important as it influences selection of therapeutic interventions for patient subsets. The primary aim of our study was to compare reporting of SGA between industry and non-industry sponsored trials. We performed a systematic literature review and extracted data from journal articles (JA) and conference abstracts (CA) published over a decade reporting SGA results of phase III randomised controlled gastrointestinal (GI) oncology trials with patient participants of ≥150. In JA, SGA was reported in 100/145 (69%) trials: 41/54 industry sponsored (76%; 95% confidence interval [CI]: 63-86%) and 59/91 non-industry sponsored (65%; 95% CI: 55-74%) trials (p = 0.16). In CA, SGA was reported in 86/204 (42%) trials: 43/83 industry sponsored (52%; 95% CI: 41-62%) and 43/121 non-industry sponsored (36%; 95% CI: 28-44%) trials (p = 0.02). Number of SGA performed per trial was significantly larger for industry compared to non-industry sponsored trials in both JA (median 6 versus 2, p = 0.003) and CA (median 1 versus 0, p = 0.023). Claims of subgroup effect were made in 52% of trials in JA and 50% in CA, with significant test of interaction evident in only 25% of JA and 16% of CA, with no difference between industry and non-industry trials. Industry sponsored trials with a significant primary end-point reported more SGA (p < 0.001 JA; p = 0.046 CA). Industry sponsored trials reported more SGA. Claimed subgroup effects were often not accompanied by significant interaction test; thus circumspection should be adopted when using SGA to deviate from standard therapeutic decision-making in GI oncology. Copyright © 2015 Elsevier Ltd. All rights reserved.

DNA Vaccination Against Metastatic Breast Cancer

DTIC Science & Technology

2001-07-01

cells. Although DNA vaccines have shown effectiveness in clinical trials , it is essential to demonstrate pre- clinical effectiveness for anti-tumor... clinical trials for infectious diseases (4), it is essential to (5-7)demonstrate pre- clinical effectiveness for anti-tumor vaccines before clinical testing...Program Clinical Translational Research (CTR) award to perform a Phase I clinical trial of ELVIS2-neu. Our preliminary application was selected for

Post-trial dopaminergic modulation of conditioned catalepsy: A single apomorphine induced increase/decrease in dopaminergic activation immediately following a conditioned catalepsy response can reverse/enhance a haloperidol conditioned and sensitized catalepsy response.

PubMed

Oliveira, Lucas Rangel; Dias, Flávia Regina Cruz; Santos, Breno Garone; Silva, Jade Leal Loureiro; Carey, Robert J; Carrera, Marinete Pinheiro

2016-09-15

Haloperidol can induce catalepsy and this drug effect can be conditioned as well as sensitized to contextual cues. We used a paired/unpaired Pavlovian conditioning protocol to establish haloperidol catalepsy conditioned and sensitized responses. Groups of rats were given 10 daily catalepsy tests following administration of vehicle (n=24) or haloperidol (1.0mg/kg) either paired (n=18) or unpaired (n=18) to testing. Subsequently, testing for conditioning was conducted and conditioning and sensitization of catalepsy were observed selectively in the paired group. Immediately following a second test for catalepsy conditioning, the groups were subdivided into 4 vehicle groups, 3 unpaired haloperidol groups and 3 paired haloperidol groups and were given one of three post-trial treatments (vehicle, 0.05mg/kg or 2.0mg/kg apomorphine). One day later the conditioned catalepsy test 3 was carried out and on the next day, a haloperidol challenge test was performed. The post-trial apomorphine treatments had major effects on the paired groups upon both conditioning and the haloperidol challenge test. The low dose apomorphine post-trial treatment enhanced both the conditioned and the haloperidol sensitized catalepsy responses. The high dose apomorphine post-trial treatment eliminated conditioned catalepsy and eliminated the initial acute catalepsy response to haloperidol that was induced in the vehicle control groups. These results demonstrate the sensitivity of conditioned drug cues to modification by increases/decreases in activity of the dopamine system in the immediate post-trial interval after a conditioning trial. This demonstration that post-trial dopaminergic drug treatments can modify conditioned drug behavior has broad implications for conditioned drug effects. Copyright © 2016 Elsevier B.V. All rights reserved.

In search of memory tests equivalent for experiments on animals and humans.

PubMed

Brodziak, Andrzej; Kołat, Estera; Różyk-Myrta, Alicja

2014-12-19

Older people often exhibit memory impairments. Contemporary demographic trends cause aging of the society. In this situation, it is important to conduct clinical trials of drugs and use training methods to improve memory capacity. Development of new memory tests requires experiments on animals and then clinical trials in humans. Therefore, we decided to review the assessment methods and search for tests that evaluate analogous cognitive processes in animals and humans. This review has enabled us to propose 2 pairs of tests of the efficiency of working memory capacity in animals and humans. We propose a basic set of methods for complex clinical trials of drugs and training methods to improve memory, consisting of 2 pairs of tests: 1) the Novel Object Recognition Test - Sternberg Item Recognition Test and 2) the Object-Location Test - Visuospatial Memory Test. We postulate that further investigations of methods that are equivalent in animals experiments and observations performed on humans are necessary.

Feasibility and Efficacy of the Nintendo Wii Gaming System to Improve Balance Performance Post-Stroke: Protocol of a Phase II Randomized Controlled Trial in an Inpatient Rehabilitation Setting.

PubMed

Bower, Kelly J; Clark, Ross A; McGinley, Jennifer L; Martin, Clarissa L; Miller, Kimberly J

2013-04-01

Balance deficits following stroke are common and debilitating. Commercially available gaming systems, such as the Nintendo(®) (Kyoto, Japan) Wii™, have been widely adopted clinically; however, there is limited evidence supporting their feasibility and efficacy for improving balance performance following stroke. The aim of this trial is to investigate the clinical feasibility and efficacy of using the Nintendo Wii gaming system as an adjunct to standard care to improve balance performance following stroke in an inpatient rehabilitation setting. Thirty participants undergoing inpatient stroke rehabilitation will be recruited into this Phase II, single-blind, randomized controlled trial. Participants will be allocated into a Balance or Upper Limb Group, and both groups will perform activities using the Nintendo Wii in addition to their standard care. Participants will attend three 45-minute sessions per week, for a minimum of 2 and a maximum of 4 weeks. The main focus of the study is to investigate the feasibility of the intervention protocol. This will be evaluated through recruitment, retention, adherence, acceptability, and safety. The Step Test and Functional Reach Test will be the primary efficacy outcomes. Secondary outcomes will include force platform, mobility, and upper limb measures. Assessments will occur at baseline, 2 weeks, and 4 weeks after study entry. To the authors' knowledge, this will be the largest randomized clinical trial to investigate the feasibility and efficacy of the Nintendo Wii gaming system for improving balance performance in a stroke population. The results will inform the design of a Phase III multicenter trial.

Test-retest reliability and minimal detectable change scores for the timed "up & go" test, the six-minute walk test, and gait speed in people with Alzheimer disease.

PubMed

Ries, Julie D; Echternach, John L; Nof, Leah; Gagnon Blodgett, Michelle

2009-06-01

With the increasing incidence of Alzheimer disease (AD), determining the validity and reliability of outcome measures for people with this disease is necessary. The goals of this study were to assess test-retest reliability of data for the Timed "Up & Go" Test (TUG), the Six-Minute Walk Test (6MWT), and gait speed and to calculate minimal detectable change (MDC) scores for each outcome measure. Performance differences between groups with mild to moderate AD and moderately severe to severe AD (as determined by the Functional Assessment Staging [FAST] scale) were studied. This was a prospective, nonexperimental, descriptive methodological study. Background data collected for 51 people with AD included: use of an assistive device, Mini-Mental Status Examination scores, and FAST scale scores. Each participant engaged in 2 test sessions, separated by a 30- to 60-minute rest period, which included 2 TUG trials, 1 6MWT trial, and 2 gait speed trials using a computerized gait assessment system. A specific cuing protocol was followed to achieve optimal performance during test sessions. Test-retest reliability values for the TUG, the 6MWT, and gait speed were high for all participants together and for the mild to moderate AD and moderately severe to severe AD groups separately (intraclass correlation coefficients > or = .973); however, individual variability of performance also was high. Calculated MDC scores at the 90% confidence interval were: TUG=4.09 seconds, 6MWT=33.5 m (110 ft), and gait speed=9.4 cm/s. The 2 groups were significantly different in performance of clinical tests, with the participants who were more cognitively impaired being more physically and functionally impaired. A single researcher for data collection limited sample numbers and prohibited blinding to dementia level. The TUG, the 6MWT, and gait speed are reliable outcome measures for use with people with AD, recognizing that individual variability of performance is high. Minimal detectable change scores at the 90% confidence interval can be used to assess change in performance over time and the impact of treatment.

Cognitive and neuropathologic correlates of Stroop Color-Word Test performance in Alzheimer's disease.

PubMed

Bondi, Mark W; Serody, Adam B; Chan, Agnes S; Eberson-Shumate, Sonja C; Delis, Dean C; Hansen, Lawrence A; Salmon, David P

2002-07-01

The Stroop Color-Word Test (SCWT; C. Golden, 1978) was examined in 59 patients with probable Alzheimer's disease (AD) and in 51 demographically comparable normal control (NC) participants. AD patients produced significantly larger Stroop interference effects than NC participants, and level of dementia severity significantly influenced SCWT performance. Principal-components analyses demonstrated a dissociation in the factor structure of the Stroop trials between NC participants and AD patients, suggesting that disruption of semantic knowledge and speeded verbal processing in AD may be a major contributor to impairment on the incongruent trial. Results of clinicopathologic correlations in an autopsy-confirmed AD subgroup further suggest the invocation of a broad network of integrated cortical regions and executive and language processes underlying successful SCWT performance.

Development, validity, and reliability of a ballet-specific aerobic fitness test.

PubMed

Twitchett, Emily; Nevill, Alan; Angioi, Manuela; Koutedakis, Yiannis; Wyon, Matthew

2011-09-01

The aim of this study was to develop and assess the reliability and validity of a multi-stage, ballet-specific aerobic fitness test to be used in a dance studio setting. The test consists of five stages, each four minutes long, that increase in intensity. It uses classical ballet movement of an intermediate-level of difficulty, thus emphasizing physiological demand rather than skill. The demand of each stage was determined by calculating the mean oxygen uptake during its final minute using a portable gas analyser. After an initial familiarization period, eight female subjects performed the test twice within seven days. The results showed significant differences in oxygen consumption between stages (p < 0.001), but not between trials. Pearson correlation co-efficients produced a very good linear relationship between trials (r = 0.998, p < 0.001). Bland-Altman reliability analysis revealed the 95% limits of agreement to be ± 6.2 ml·kg(-1)·min(-1), showing good agreement between trials. The oxygen uptake in our subjects equated positively to previous estimates for class and performance, confirming validity. It was concluded that the test is suitable for use among classical ballet dancers, with many possible applications.

ANTHELMINTIC EFFECTS OF DRIED GROUND BANANA PLANT LEAVES (MUSA SPP.) FED TO SHEEP ARTIFICIALLY INFECTED WITH HAEMONCHUS CONTORTUS AND TRICHOSTRONGYLUS COLUBRIFORMIS

PubMed Central

Gregory, Lilian; Yoshihara, Eidi; Silva, Leandro Kataoaka Fernandes; Marques, Eduardo Carvalho; Ribeiro, Bruno Leonardo Mendonça; de Souza Meira, Enoch Brandão; Rossi, Rodolfo Santos; do Amarante, Alessandro Francisco Talamini; Hasegawa, Marjorie Yumi

2017-01-01

Background: Helminths is a endoparasites that cause the major losses for profitable sheep production in Brazil. The increased development of resistant strains of endoparasites have enforced the search for sustainable alternatives. The aim of this paper was to provide information about endoparasites control with banana leaves in infected sheep as alternative control strategies and see its viability. Materials and Methods: In this study, we performed two trials to investigate the anthelmintic properties of banana leaves on endoparasites in sheep. In Trial 1, twelve sheep were artificially infected with Trichostrongylus colubriformis; in Trial 2, eleven sheep were artificially infected with Haemonchus contortus. Clinical examinations, packed cell volume, total protein, faecal egg counts (FECs) and egg hatchability tests (EHTs) were performed. At the end of the trials, the sheep were humanely slaughtered, and total worm counts were performed. Results: In Trial 1 and 2, no significant FEC decreases were note but significant diference in EHTs were observed. Total worm counts, clinical and haematological parameters did not reveal significant changes between the treatment and control groups. These results suggest that feeding dried ground banana plant leaves to sheep may reduce the viability of Trichostrongylus colubriformis eggs, and this anthelmintic activity is potentially exploitable as part of an integrated parasite management programme. Conclusion: However, further investigation is needed to establish the optimal dosage, develop a convenient delivery form and confirm the economic feasibility of using banana plantation byproducts as feed for ruminant species. Abbreviations: Coproculture test (CT)., Faecal egg count (FEC)., Egg hatchability test (EHT) PMID:28480391

ANTHELMINTIC EFFECTS OF DRIED GROUND BANANA PLANT LEAVES (MUSA SPP.) FED TO SHEEP ARTIFICIALLY INFECTED WITH HAEMONCHUS CONTORTUS AND TRICHOSTRONGYLUS COLUBRIFORMIS.

PubMed

Gregory, Lilian; Yoshihara, Eidi; Silva, Leandro Kataoaka Fernandes; Marques, Eduardo Carvalho; Ribeiro, Bruno Leonardo Mendonça; de Souza Meira, Enoch Brandão; Rossi, Rodolfo Santos; do Amarante, Alessandro Francisco Talamini; Hasegawa, Marjorie Yumi

2017-01-01

Helminths is a endoparasites that cause the major losses for profitable sheep production in Brazil. The increased development of resistant strains of endoparasites have enforced the search for sustainable alternatives. The aim of this paper was to provide information about endoparasites control with banana leaves in infected sheep as alternative control strategies and see its viability. In this study, we performed two trials to investigate the anthelmintic properties of banana leaves on endoparasites in sheep. In Trial 1, twelve sheep were artificially infected with Trichostrongylus colubriformis ; in Trial 2, eleven sheep were artificially infected with Haemonchus contortus . Clinical examinations, packed cell volume, total protein, faecal egg counts (FECs) and egg hatchability tests (EHTs) were performed. At the end of the trials, the sheep were humanely slaughtered, and total worm counts were performed. In Trial 1 and 2, no significant FEC decreases were note but significant diference in EHTs were observed. Total worm counts, clinical and haematological parameters did not reveal significant changes between the treatment and control groups. These results suggest that feeding dried ground banana plant leaves to sheep may reduce the viability of Trichostrongylus colubriformis eggs, and this anthelmintic activity is potentially exploitable as part of an integrated parasite management programme. However, further investigation is needed to establish the optimal dosage, develop a convenient delivery form and confirm the economic feasibility of using banana plantation byproducts as feed for ruminant species. Abbreviations: Coproculture test (CT)., Faecal egg count (FEC)., Egg hatchability test (EHT).

Peanut variety tests

USDA-ARS?s Scientific Manuscript database

State-wide peanut variety trials were conducted in three Oklahoma locations. Performance of runner, Spanish, and Virginia entries were assessed. Performance of runner varieties depended on location but averages across locations indicate that advanced breeding line ARSOK R47A was the top performer....

Feasibility of the adaptive and automatic presentation of tasks (ADAPT) system for rehabilitation of upper extremity function post-stroke

PubMed Central

2011-01-01

Background Current guidelines for rehabilitation of arm and hand function after stroke recommend that motor training focus on realistic tasks that require reaching and manipulation and engage the patient intensively, actively, and adaptively. Here, we investigated the feasibility of a novel robotic task-practice system, ADAPT, designed in accordance with such guidelines. At each trial, ADAPT selects a functional task according to a training schedule and with difficulty based on previous performance. Once the task is selected, the robot picks up and presents the corresponding tool, simulates the dynamics of the tasks, and the patient interacts with the tool to perform the task. Methods Five participants with chronic stroke with mild to moderate impairments (> 9 months post-stroke; Fugl-Meyer arm score 49.2 ± 5.6) practiced four functional tasks (selected out of six in a pre-test) with ADAPT for about one and half hour and 144 trials in a pseudo-random schedule of 3-trial blocks per task. Results No adverse events occurred and ADAPT successfully presented the six functional tasks without human intervention for a total of 900 trials. Qualitative analysis of trajectories showed that ADAPT simulated the desired task dynamics adequately, and participants reported good, although not excellent, task fidelity. During training, the adaptive difficulty algorithm progressively increased task difficulty leading towards an optimal challenge point based on performance; difficulty was then continuously adjusted to keep performance around the challenge point. Furthermore, the time to complete all trained tasks decreased significantly from pretest to one-hour post-test. Finally, post-training questionnaires demonstrated positive patient acceptance of ADAPT. Conclusions ADAPT successfully provided adaptive progressive training for multiple functional tasks based on participant's performance. Our encouraging results establish the feasibility of ADAPT; its efficacy will next be tested in a clinical trial. PMID:21813010

Physical qualities and activity profiles of sub-elite and recreational Australian football players.

PubMed

Stein, Josh G; Gabbett, Tim J; Townshend, Andrew D; Dawson, Brian T

2015-11-01

To investigate the relationship between physical qualities and match activity profiles of recreational Australian football players. Prospective cohort study. Forty players from three recreational Australian football teams (Division One, Two and Three) underwent a battery of fitness tests (vertical jump, 10 and 40 m sprint, 6 m × 30 m repeated sprint test, Yo-Yo intermittent recovery level Two and 2-km time trial). The activity profiles of competitive match-play were quantified using 10-Hz Global Positioning System units. Division One players possessed greater maximum velocity, Yo-Yo level Two and 2-km time trial performances than Division Two and Three players. In addition, Division One players covered greater relative distance, and relative distances at moderate- and high-intensities during match-play than Division Two and Three players. Division Two players had better 2-km time trial performances than Division Three players. Positive associations (P < 0.05) were found between 10 m acceleration, maximum velocity, Yo-Yo level Two and 2-km time trial performances and relative distance, and relative distances covered at moderate- and high-intensities during match-play. Moderate relationships were found between vertical jump and relative distance and high-intensity running. Sub-elite Australian football players competing at a higher level exhibit greater physical qualities and match-play activity profiles than lesser-skilled recreational players. Acceleration and maximum velocity, 2-km time trial and Yo-Yo level Two performances discriminate between players of different playing levels, and are related to physical match performance in recreational Australian football. The development of these qualities is likely to contribute to improved match performance in recreational Australian football players. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Effect of voluntary hypocapnic hyperventilation on the metabolic response during Wingate anaerobic test.

PubMed

Fujii, Naoto; Tsuchiya, Sho-Ichiro; Tsuji, Bun; Watanabe, Kazuhito; Sasaki, Yosuke; Nishiyasu, Takeshi

2015-09-01

We evaluated whether hypocapnia achieved through voluntary hyperventilation diminishes the increases in oxygen uptake elicited by short-term (e.g., ~30 s) all-out exercise without affecting exercise performance. Nine subjects performed 30-s Wingate anaerobic tests (WAnT) in control and hypocapnia trials on separate days in a counterbalanced manner. During the 20-min rest prior to the 30-s WAnT, the subjects in the hypocapnia trial performed voluntary hyperventilation (minute ventilation = 31 L min(-1)), while the subjects in the control trial continued breathing spontaneously (minute ventilation = 14 L min(-1)). The hyperventilation in the hypocapnia trial reduced end-tidal CO2 pressure from 34.8 ± 2.5 mmHg at baseline rest to 19.3 ± 1.0 mmHg immediately before the 30-s WAnT. In the control trial, end-tidal CO2 pressure at baseline rest (35.9 ± 2.5 mmHg) did not differ from that measured immediately before the 30-s WAnT (35.9 ± 3.3 mmHg). Oxygen uptake during the 30-s WAnT was lower in the hypocapnia than the control trial (1.55 ± 0.52 vs. 1.95 ± 0.44 L min(-1)), while the postexercise peak blood lactate concentration was higher in the hypocapnia than control trial (10.4 ± 1.9 vs. 9.6 ± 1.9 mmol L(-1)). In contrast, there was no difference in the 5-s peak (842 ± 111 vs. 850 ± 107 W) or mean (626 ± 74 vs. 639 ± 80 W) power achieved during the 30-s WAnT between the control and hypocapnia trials. These results suggest that during short-period all-out exercise (e.g., 30-s WAnT), hypocapnia induced by voluntary hyperventilation reduces the aerobic metabolic rate without affecting exercise performance. This implies a compensatory elevation in the anaerobic metabolic rate.

A Randomized Clinical Trial Comparing Use of Rapid Molecular Testing for Staphylococcus aureus for Patients With Cutaneous Abscesses in the Emergency Department With Standard of Care

PubMed Central

May, Larissa S.; Rothman, Richard E.; Miller, Loren G.; Brooks, Gillian; Zocchi, Mark; Zatorski, Catherine; Dugas, Andrea F.; Ware, Chelsea E.; Jordan, Jeanne A.

2017-01-01

OBJECTIVE To determine whether real-time availability of rapid molecular results of Staphylococcus aureus would impact emergency department clinician antimicrobial selection for adults with cutaneous abscesses. DESIGN We performed a prospective, randomized controlled trial comparing a rapid molecular test with standard of care culture-based testing. Follow-up telephone calls were made at between 2 and 7 days, 1 month, and 3 months after discharge. SETTING Two urban, academic emergency departments. PATIENTS Patients at least 18 years old presenting with a chief complaint of abscess, cellulitis, or insect bite and receiving incision and drainage were eligible. Seven hundred seventy-eight people were assessed for eligibility and 252 met eligibility criteria. METHODS Clinician antibiotic selection and clinical outcomes were evaluated. An ad hoc outcome of test performance was performed. RESULTS We enrolled 252 patients and 126 were randomized to receive the rapid test. Methicillin-susceptible S. aureus–positive patients receiving rapid test results were prescribed beta-lactams more often than controls (absolute difference, 14.5% [95% CI, 1.1%–30.1%]) whereas methicillin-resistant S. aureus–positive patients receiving rapid test results were more often prescribed anti–methicillin-resistant S. aureus antibiotics (absolute difference, 21.5% [95% CI, 10.1%–33.0%]). There were no significant differences between the 2 groups in 1-week or 3-month clinical outcomes. CONCLUSION Availability of rapid molecular test results after incision and drainage was associated with more-targeted antibiotic selection. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01523899 PMID:26306996

Study protocol: effect of playful training on functional abilities of older adults - a randomized controlled trial.

PubMed

Jessen, Jari Due; Lund, Henrik Hautop

2017-01-19

Loss of functional capabilities due to inactivity is one of the most common reasons for fall accidents, and it has been well established that loss of capabilities can be effectively reduced by physical activity. Pilot studies indicate a possible improvement in functional abilities of community dwelling elderly as a result of short-term playing with an exergame system in the form of interactive modular tiles. Such playful training may be motivational to perform and viewed by the subjects to offer life-fulfilling quality, while providing improvement in physical abilities, e.g. related to prevent fall accidents. The RCT will test for a variety of health parameters of community-dwelling elderly playing on interactive modular tiles. The study will be a single blinded, randomized controlled trial with 60 community-dwelling adults 70+ years. The trial will consist an intervention group of 30 participants training with the interactive modular tiles, and a control group of 30 participants that will receive the usual care provided to non-patient elderly. The intervention period will be 12 weeks. The intervention group will perform group training (4-5 individuals for 1 h training session with each participant receiving 13 min training) on the interactive tiles twice a week. Follow-up tests include 6-min Walk Test (6MWT), the 8-ft Timed Up & Go Test (TUG), and the Chair-Stand Test (CS) from the Senior Fitness Test, along with balancing tests (static test on Wii Board and Line Walk test). Secondary outcomes related to adherence, motivation and acceptability will be investigated through semi-structured interviews. Data will be collected from pre- and post-tests. Data will be analyzed for statistically significant differences by checking that there is a Gaussian distribution and then using paired t-test, otherwise using Wilcoxon signed-rank test. "Intention to treat" analysis will be done. The trial tests for increased mobility, agility, balancing and general fitness of community-dwelling elderly as a result of playing, in this case on modular interactive tiles. A positive outcome may help preventing loss of functional capabilities due to inactivity. ClinicalTrials.gov: Nr. NCT02496702 , Initial Release date 7/7-2015.

Discrepancies between bilinguals' performance on the Spanish and English versions of the WAIS Digit Span task: Cross-cultural implications.

PubMed

López, Enrique; Steiner, Alexander J; Hardy, David J; IsHak, Waguih W; Anderson, W Brantley

2016-01-01

This study explored within-subjects differences in the performance of 40 bilingual participants on the English and Spanish versions of the Wechsler Adult Intelligence Scale (WAIS) Digit Span task. To test the linguistic hypothesis that individuals would perform worse in Spanish because of its syllabic demand, we compared the number of syllables correctly recalled by each participant for every correct trial. Our analysis of the correct number of syllables remembered per trial showed that participants performed significantly better (i.e., recalling more syllables) in Spanish than in English on the total score. Findings suggest the Spanish version of the Digit Span (total score) was significantly more difficult than the English version utilizing traditional scoring methods. Moreover, the Forward Trial, rather than the Backward Trial, was more likely to show group differences between both language versions. Additionally, the Spanish trials of the Digit Span were correlated with language comprehension and verbal episodic memory measures, whereas the English trials of the Digit Span were correlated with confrontational naming and verbal fluency tasks. The results suggest that more research is necessary to further investigate other cognitive factors, rather than just syllabic demand, that might contribute to performance and outcome differences on the WAIS Digit Span in Spanish-English bilinguals.

Undisclosed antiretroviral drug use in a multinational clinical trial (HIV Prevention Trials Network 052).

PubMed

Fogel, Jessica M; Wang, Lei; Parsons, Teresa L; Ou, San-San; Piwowar-Manning, Estelle; Chen, Ying; Mudhune, Victor O; Hosseinipour, Mina C; Kumwenda, Johnstone; Hakim, James G; Chariyalertsak, Suwat; Panchia, Ravindre; Sanne, Ian; Kumarasamy, Nagalingeswaran; Grinsztejn, Beatriz; Makhema, Joseph; Pilotto, Jose; Santos, Breno R; Mayer, Kenneth H; McCauley, Marybeth; Gamble, Theresa; Bumpus, Namandjé N; Hendrix, Craig W; Cohen, Myron S; Eshleman, Susan H

2013-11-15

The HIV Prevention Trials Network 052 study enrolled serodiscordant couples. Index participants infected with human immunodeficiency virus reported no prior antiretroviral (ARV) treatment at enrollment. ARV drug testing was performed retrospectively using enrollment samples from a subset of index participants. ARV drugs were detected in 45 of 96 participants (46.9%) with an undetectable viral load, 2 of 48 (4.2%) with a low viral load, and 1 of 65 (1.5%) with a high viral load (P < .0001); they were also detected in follow-up samples from participants who were not receiving study-administered treatment. ARV drug testing may be useful in addition to self-report of ARV drug use in some clinical trial settings.

Understanding the Transfer Deficit: Contextual Mismatch, Proactive Interference, and Working Memory Affect Toddlers' Video-Based Transfer.

PubMed

Choi, Koeun; Kirkorian, Heather L; Pempek, Tiffany A

2017-04-17

Researchers tested the impact of contextual mismatch, proactive interference, and working memory (WM) on toddlers' transfer across contexts. Forty-two toddlers (27-34 months) completed four object-retrieval trials, requiring memory updating on Trials 2-4. Participants watched hiding events on a tablet computer. Search performance was tested using another tablet (match) or a felt board (mismatch). WM was assessed. On earlier search trials, WM predicted transfer in both conditions, and toddlers in the match condition outperformed those in the mismatch condition; however, the benefit of contextual match and WM decreased over trials. Contextual match apparently increased proactive interference on later trials. Findings are interpreted within existing accounts of the transfer deficit, and a combined account is proposed. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

The influence of trial order on learning from reward vs. punishment in a probabilistic categorization task: experimental and computational analyses.

PubMed

Moustafa, Ahmed A; Gluck, Mark A; Herzallah, Mohammad M; Myers, Catherine E

2015-01-01

Previous research has shown that trial ordering affects cognitive performance, but this has not been tested using category-learning tasks that differentiate learning from reward and punishment. Here, we tested two groups of healthy young adults using a probabilistic category learning task of reward and punishment in which there are two types of trials (reward, punishment) and three possible outcomes: (1) positive feedback for correct responses in reward trials; (2) negative feedback for incorrect responses in punishment trials; and (3) no feedback for incorrect answers in reward trials and correct answers in punishment trials. Hence, trials without feedback are ambiguous, and may represent either successful avoidance of punishment or failure to obtain reward. In Experiment 1, the first group of subjects received an intermixed task in which reward and punishment trials were presented in the same block, as a standard baseline task. In Experiment 2, a second group completed the separated task, in which reward and punishment trials were presented in separate blocks. Additionally, in order to understand the mechanisms underlying performance in the experimental conditions, we fit individual data using a Q-learning model. Results from Experiment 1 show that subjects who completed the intermixed task paradoxically valued the no-feedback outcome as a reinforcer when it occurred on reinforcement-based trials, and as a punisher when it occurred on punishment-based trials. This is supported by patterns of empirical responding, where subjects showed more win-stay behavior following an explicit reward than following an omission of punishment, and more lose-shift behavior following an explicit punisher than following an omission of reward. In Experiment 2, results showed similar performance whether subjects received reward-based or punishment-based trials first. However, when the Q-learning model was applied to these data, there were differences between subjects in the reward-first and punishment-first conditions on the relative weighting of neutral feedback. Specifically, early training on reward-based trials led to omission of reward being treated as similar to punishment, but prior training on punishment-based trials led to omission of reward being treated more neutrally. This suggests that early training on one type of trials, specifically reward-based trials, can create a bias in how neutral feedback is processed, relative to those receiving early punishment-based training or training that mixes positive and negative outcomes.

A data grid for imaging-based clinical trials

NASA Astrophysics Data System (ADS)

Zhou, Zheng; Chao, Sander S.; Lee, Jasper; Liu, Brent; Documet, Jorge; Huang, H. K.

2007-03-01

Clinical trials play a crucial role in testing new drugs or devices in modern medicine. Medical imaging has also become an important tool in clinical trials because images provide a unique and fast diagnosis with visual observation and quantitative assessment. A typical imaging-based clinical trial consists of: 1) A well-defined rigorous clinical trial protocol, 2) a radiology core that has a quality control mechanism, a biostatistics component, and a server for storing and distributing data and analysis results; and 3) many field sites that generate and send image studies to the radiology core. As the number of clinical trials increases, it becomes a challenge for a radiology core servicing multiple trials to have a server robust enough to administrate and quickly distribute information to participating radiologists/clinicians worldwide. The Data Grid can satisfy the aforementioned requirements of imaging based clinical trials. In this paper, we present a Data Grid architecture for imaging-based clinical trials. A Data Grid prototype has been implemented in the Image Processing and Informatics (IPI) Laboratory at the University of Southern California to test and evaluate performance in storing trial images and analysis results for a clinical trial. The implementation methodology and evaluation protocol of the Data Grid are presented.

Measures of rowing performance.

PubMed

Smith, T Brett; Hopkins, Will G

2012-04-01

Accurate measures of performance are important for assessing competitive athletes in practi~al and research settings. We present here a review of rowing performance measures, focusing on the errors in these measures and the implications for testing rowers. The yardstick for assessing error in a performance measure is the random variation (typical or standard error of measurement) in an elite athlete's competitive performance from race to race: ∼1.0% for time in 2000 m rowing events. There has been little research interest in on-water time trials for assessing rowing performance, owing to logistic difficulties and environmental perturbations in performance time with such tests. Mobile ergometry via instrumented oars or rowlocks should reduce these problems, but the associated errors have not yet been reported. Measurement of boat speed to monitor on-water training performance is common; one device based on global positioning system (GPS) technology contributes negligible extra random error (0.2%) in speed measured over 2000 m, but extra error is substantial (1-10%) with other GPS devices or with an impeller, especially over shorter distances. The problems with on-water testing have led to widespread use of the Concept II rowing ergometer. The standard error of the estimate of on-water 2000 m time predicted by 2000 m ergometer performance was 2.6% and 7.2% in two studies, reflecting different effects of skill, body mass and environment in on-water versus ergometer performance. However, well trained rowers have a typical error in performance time of only ∼0.5% between repeated 2000 m time trials on this ergometer, so such trials are suitable for tracking changes in physiological performance and factors affecting it. Many researchers have used the 2000 m ergometer performance time as a criterion to identify other predictors of rowing performance. Standard errors of the estimate vary widely between studies even for the same predictor, but the lowest errors (~1-2%) have been observed for peak power output in an incremental test, some measures of lactate threshold and measures of 30-second all-out power. Some of these measures also have typical error between repeated tests suitably low for tracking changes. Combining measures via multiple linear regression needs further investigation. In summary, measurement of boat speed, especially with a good GPS device, has adequate precision for monitoring training performance, but adjustment for environmental effects needs to be investigated. Time trials on the Concept II ergometer provide accurate estimates of a rower's physiological ability to output power, and some submaximal and brief maximal ergometer performance measures can be used frequently to monitor changes in this ability. On-water performance measured via instrumented skiffs that determine individual power output may eventually surpass measures derived from the Concept II.

A loud auditory stimulus overcomes voluntary movement limitation in cervical dystonia.

PubMed

Serranová, Tereza; Jech, Robert; Martí, Maria José; Modreanu, Raluca; Valldeoriola, Francesc; Sieger, Tomáš; Růžička, Evžen; Valls-Solé, Josep

2012-01-01

Patients with cervical dystonia (CD) present with an impaired performance of voluntary neck movements, which are usually slow and limited. We hypothesized that such abnormality could involve defective preparation for task execution. Therefore, we examined motor preparation in CD patients using the StartReact method. In this test, a startling auditory stimulus (SAS) is delivered unexpectedly at the time of the imperative signal (IS) in a reaction time task to cause a faster execution of the prepared motor programme. We expected that CD patients would show an abnormal StartReact phenomenon. Fifteen CD patients and 15 age matched control subjects (CS) were asked to perform a rotational movement (RM) to either side as quick as possible immediately after IS perception (a low intensity electrical stimulus to the II finger). In randomly interspersed test trials (25%) a 130 dB SAS was delivered simultaneously with the IS. We recorded RMs in the horizontal plane with a high speed video camera (2.38 ms per frame) in synchronization with the IS. The RM kinematic-parameters (latency, velocity, duration and amplitude) were analyzed using video-editing software and screen protractor. Patients were asked to rate the difficulty of their RMs in a numerical rating scale. In control trials, CD patients executed slower RMs (repeated measures ANOVA, p<0.10(-5)), and reached a smaller final head position angle relative to the midline (p<0.05), than CS. In test trials, SAS improved all RMs in both groups (p<0.10(-14)). In addition, patients were more likely to reach beyond their baseline RM than CS (χ(2), p<0.001) and rated their performance better than in control trials (t-test, p<0.01). We found improvement of kinematic parameters and subjective perception of motor performance in CD patients with StartReact testing. Our results suggest that CD patients reach an adequate level of motor preparation before task execution.

No effect on performance tests from a neuromuscular warm-up programme in youth female football: a randomised controlled trial.

PubMed

Lindblom, Hanna; Waldén, Markus; Hägglund, Martin

2012-10-01

The objective of the present randomised controlled trial was to study the effect of a neuromuscular warm-up programme on performance tests in youth female football. Four youth female football teams with players aged 12-16 years were randomised into an intervention group and control group. The intervention was a 15-min neuromuscular warm-up programme carried out twice a week during the 11-week study period. Baseline and follow-up measurements of performance were made indoors and included the star excursion balance test, a countermovement jump test, a triple-hop for distance test, a modified Illinois agility test, and 10- and 20-m sprint tests. Fifty-two players (intervention 28; control 24) took part in baseline measurements, and after dropout, 41 players (intervention 23; control 18) were included for analysis. Minor positive changes were seen in the control group compared to the intervention group for a sub-score of the star excursion balance test (P < 0.05) and in the modified Illinois agility test (P < 0.05). No improvement was seen in the intervention group from baseline to follow-up. The study showed that a neuromuscular warm-up programme carried out during 11 weeks did not improve performance in youth female football. This could indicate that the programme does not contain sufficient stimulus to improve performance. A low player attendance at training sessions, and low specificity between exercises in the warm-up programme and the evaluated performance tests may also contribute to the lack of effect. I.

Heart of the Hearth: Making the Popular Clean, Not the Clean Popular - Technology Research, Development, and Tools for Clean Biomass Cookstoves

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

Gist, Ryan

This technical report summarizes the work completed by BioLite in fulfilment of the US DOE EERE award. The work plan focused on three key objectives: developing an optimized combustion system that demonstrates high combustion efficiency and low PM 2.5 and CO emissions, integrate the system into popular stove phenotypes – side-fed rocket stove architecture like the BioLite HomeStove, and the Patsari chimney stove in Mexico such that they maintain their important phenotypical characteristics, independently evaluate quantitative fuel and emissions performance of the integrated ‘Turbo-Patsari’ in Mexican households. The project activities were organized into six major tasks: A. Develop, fabricate, andmore » test proof-of-concept prototypes B. Develop field prototypes, assess user feedback and field performance C. Define revised stove design for pre-production model, Identify manufacturing requirements and estimated cost to build, Conduct reliability, emissions, and performance testing of pre-production Turbo-Patsari D. Build pre-production Turbo-Patsari stove combustion cores E. Conduct pre-production field trials F. Summarize field trial results and evaluate Turbo-Patsari for potential volume production. A two-pronged approach was adopted for the above tasks. The first involved building a modular test platform that allowed parametric variation of multiple stove design parameters that directly affect its performance – heat output, thermal efficiency, and emissions. The second part of the approach comprised of building a surrogate Patsari based on GIRA’s specifications that could then be modified or retrofitted for optimum performance based on the learnings from the modular test platform. The following sections of the report will describe the findings of tests on these platform, the subsequent development, design, and installation of the Turbo-Patsari, and finally the in-home field trial.« less

Validation of a modification to Performance-Tested Method 010403: microwell DNA hybridization assay for detection of Listeria spp. in selected foods and selected environmental surfaces.

PubMed

Alles, Susan; Peng, Linda X; Mozola, Mark A

2009-01-01

A modification to Performance-Tested Method 010403, GeneQuence Listeria Test (DNAH method), is described. The modified method uses a new media formulation, LESS enrichment broth, in single-step enrichment protocols for both foods and environmental sponge and swab samples. Food samples are enriched for 27-30 h at 30 degrees C, and environmental samples for 24-48 h at 30 degrees C. Implementation of these abbreviated enrichment procedures allows test results to be obtained on a next-day basis. In testing of 14 food types in internal comparative studies with inoculated samples, there were statistically significant differences in method performance between the DNAH method and reference culture procedures for only 2 foods (pasteurized crab meat and lettuce) at the 27 h enrichment time point and for only a single food (pasteurized crab meat) in one trial at the 30 h enrichment time point. Independent laboratory testing with 3 foods showed statistical equivalence between the methods for all foods, and results support the findings of the internal trials. Overall, considering both internal and independent laboratory trials, sensitivity of the DNAH method relative to the reference culture procedures was 90.5%. Results of testing 5 environmental surfaces inoculated with various strains of Listeria spp. showed that the DNAH method was more productive than the reference U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) culture procedure for 3 surfaces (stainless steel, plastic, and cast iron), whereas results were statistically equivalent to the reference method for the other 2 surfaces (ceramic tile and sealed concrete). An independent laboratory trial with ceramic tile inoculated with L. monocytogenes confirmed the effectiveness of the DNAH method at the 24 h time point. Overall, sensitivity of the DNAH method at 24 h relative to that of the USDA-FSIS method was 152%. The DNAH method exhibited extremely high specificity, with only 1% false-positive reactions overall.

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

PubMed

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

2016-06-01

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

Effect of insulin therapy and dietary adjustments on safety and performance during simulated soccer tests in people with type 1 diabetes: study protocol for a randomized controlled trial.

PubMed

Calvo-Marín, Javier; Torrealba-Acosta, Gabriel; Campbell, Matthew; Gaboury, Jesse; Ali, Ajmol; Chen-Ku, Chih Hao

2017-07-20

Despite the reduction in glycemic derangement in patients with type 1 diabetes mellitus (T1D) through dietary and therapeutic adjustments implemented before, during and after continuous exercise, evidence for its effectiveness with intermittent forms of exercise, such as soccer, is still lacking. We designed a study protocol for a randomized, crossover, double-blinded, controlled trial, for the evaluation of the effect that a strategy of dietary and therapeutic modifications may have on safety and performance of persons with T1D in soccer training sessions and cognitive testing. Inclusion criteria comprise: age older than 18 years, more than 2 years since T1D diagnosis, low C-peptide level, a stable insulin regimen, HbA1c less than 9.0% and regular participation in soccer activities. Our primary outcome evaluates safety regarding hypoglycemia events in patients using dietary and therapeutic adjustments, compared with the performance under the implementation of current American Diabetes Association (ADA) usual recommendations for nutritional and pharmacological adjustments for exercise. Additionally, we will evaluate as secondary outcomes: soccer performance, indexed by performance in well-established soccer skill tests, cognitive functions (indexed by Stroop, digital vigilance test (DVT), Corsi block-tapping task (CBP), and rapid visual information processing (RVIP) tests), and glycemic control measured with a continuous glucose monitor (CGM). Dietary and insulin adjustments standardized under a 4-step method strategy have never been tested in a clinical trial setting with intermittent forms of exercise, such as soccer. We hypothesize that through this strategy we will observe better performance by persons with T1D in soccer and cognitive evaluations, and more stable control of glycemic parameters before, during and after exercise execution, indexed by CGM measurements. ISRCTN, ISRCTN17447843. Registered on 5 January 2017.

A scientific nutrition strategy improves time trial performance by ≈6% when compared with a self-chosen nutrition strategy in trained cyclists: a randomized cross-over study.

PubMed

Hottenrott, Kuno; Hass, Erik; Kraus, Manon; Neumann, Georg; Steiner, Martin; Knechtle, Beat

2012-08-01

We investigated whether an athlete's self-chosen nutrition strategy (A), compared with a scientifically determined one (S), led to an improved endurance performance in a laboratory time trial after an endurance exercise. S consisted of about 1000 mL·h(-1) fluid, in portions of 250 mL every 15 min, 0.5 g sodium·L(-1), 60 g glucose·h(-1), 30 g fructose·h(-1), and 5 mg caffeine·kg body mass(-1). Eighteen endurance-trained cyclists (16 male; 2 female) were tested using a randomized crossover-design at intervals of 2 weeks, following either A or S. After a warm-up, a maximal oxygen uptake test was performed. Following a 30-min break, a 2.5-h endurance exercise on a bicycle ergometer was carried out at 70% maximal oxygen uptake. After 5 min of rest, a time trial of 64.37 km (40 miles) was completed. The ingested nutrition was recorded every 15 min. In S, the athletes completed the time trial faster (128 vs. 136 min; p ≤ 0.001) and with a significantly higher power output (212 vs. 184 W; p ≤ 0.001). The intake of fluid, energy (carbohydrate-, mono-, and disaccharide), and sodium was significantly higher in S compared with A (p ≤ 0.001) during the endurance exercise. In the time trial, only sodium intake was significantly higher in S (p ≤ 0.001). We concluded that a time trial performance after a 2.5-h endurance exercise in a laboratory setting was significantly improved following a scientific nutrition strategy.

Intraindividual Variability in Test-Retest Air Displacement Plethysmography Measurements of Body Density for Men and Women.

PubMed

Gibson, Ann L; Roper, Jenevieve L; Mermier, Christine M

2016-10-01

Air displacement plethysmography (ADP) is a popular method for estimating body density (Db). Most ADP tests are performed once, with test-retest investigations scarce. Therefore, we investigated test-retest reliability of ADP. Active men (n = 25) and women (n = 25) volunteered and followed standard pretest guidelines. Participants wore dry, form-fitting swimwear and manufacturer-supplied swim caps. In a single session, two ADP trials with measured thoracic gas volume (TGV) were performed without repositioning participants. Separate 2 (sex) × 2 (ADP trial) repeated-measures ANOVAs were performed to investigate within-between comparisons of Db, TGV, body volume (Vb), and relative fatness (%BF). Paired t tests were used to investigate significant differences as appropriate. The Bland and Altman technique was used to depict individual intertrial variations. For all analyses, α =.05. A significant main effect for sex was found; men were lower in %BF and higher in all other variables compared with women. Individual variability was notable (ADP1-ADP2). The range of individual intertrial differences were larger for women than men, respectively, for Db (-0.0096-0.0045 g/cc; -0.0019-0.0054 g/cc), TGV (-0.623-1.325 L; -0.584-0.378 L), Vb (-0.249-2.10 L; -0.234-0.397 L), and %BF (-2.1-4.4%; -0.2-0.9%). When assessing body composition of women via ADP or using Db from ADP in a multicomponent model, at least two trials with measured TGV should be performed and the average of the values recorded and reported.

The impact of a point-of-care testing device on CVD risk assessment completion in New Zealand primary-care practice: A cluster randomised controlled trial and qualitative investigation.

PubMed

Wells, Sue; Rafter, Natasha; Kenealy, Timothy; Herd, Geoff; Eggleton, Kyle; Lightfoot, Rose; Arcus, Kim; Wadham, Angela; Jiang, Yannan; Bullen, Chris

2017-01-01

To assess the effect of a point of care (POC) device for testing lipids and HbA1c in addition to testing by community laboratory facilities (usual practice) on the completion of cardiovascular disease (CVD) risk assessments in general practice. We conducted a pragmatic, cluster randomised controlled trial in 20 New Zealand general practices stratified by size and rurality and randomised to POC device plus usual practice or usual practice alone (controls). Patients aged 35-79 years were eligible if they met national guideline criteria for CVD risk assessment. Data on CVD risk assessments were aggregated using a web-based decision support programme common to each practice. Data entered into the on-line CVD risk assessment form could be saved pending blood test results. The primary outcome was the proportion of completed CVD risk assessments. Qualitative data on practice processes for CVD risk assessment and feasibility of POC testing were collected at the end of the study by interviews and questionnaire. The POC testing was supported by a comprehensive quality assurance programme. A CVD risk assessment entry was recorded for 7421 patients in 10 POC practices and 6217 patients in 10 control practices; 99.5% of CVD risk assessments had complete data in both groups (adjusted odds ratio 1.02 [95%CI 0.61-1.69]). There were major external influences that affected the trial: including a national performance target for CVD risk assessment and changes to CVD guidelines. All practices had invested in systems and dedicated staff time to identify and follow up patients to completion. However, the POC device was viewed by most as an additional tool rather than as an opportunity to review practice work flow and leverage the immediate test results for patient education and CVD risk management discussions. Shortly after commencement, the trial was halted due to a change in the HbA1c test assay performance. The trial restarted after the manufacturing issue was rectified but this affected the end use of the device. Performance incentives and external influences were more powerful modifiers of practice behaviours than the POC device in relation to CVD risk assessment completion. The promise of combining risk assessment, communication and management within one consultation was not realised. With shifts in policy focus, the utility of POC devices for patient engagement in CVD preventive care may be demonstrated if fully integrated into the clinical setting. Australian New Zealand Clinical Trials Registry ACTRN12613000607774.

Acute exercise performed close to the anaerobic threshold improves cognitive performance in elderly females.

PubMed

Córdova, C; Silva, V C; Moraes, C F; Simões, H G; Nóbrega, O T

2009-05-01

The objective of the present study was to compare the effect of acute exercise performed at different intensities in relation to the anaerobic threshold (AT) on abilities requiring control of executive functions or alertness in physically active elderly females. Forty-eight physically active elderly females (63.8 +/- 4.6 years old) were assigned to one of four groups by drawing lots: control group without exercise or trial groups with exercise performed at 60, 90, or 110% of AT (watts) and submitted to 5 cognitive tests before and after exercise. Following cognitive pretesting, an incremental cycle ergometer test was conducted to determine AT using a fixed blood lactate concentration of 3.5 mmol/L as cutoff. Acute exercise executed at 90% of AT resulted in significant (P < 0.05, ANOVA) improvement in the performance of executive functions when compared to control in 3 of 5 tests (verbal fluency, Tower of Hanoi test (number of movements), and Trail Making test B). Exercising at 60% of AT did not improve results of any tests for executive functions, whereas exercise executed at 110% of AT only improved the performance in one of these tests (verbal fluency) compared to control. Women from all trial groups exhibited a remarkable reduction in the Simple Response Time (alertness) test (P = 0.001). Thus, physical exercise performed close to AT is more effective to improve cognitive processing of older women even if conducted acutely, and using a customized exercise prescription based on the anaerobic threshold should optimize the beneficial effects.

45 CFR 304.20 - Availability and rate of Federal financial participation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... development of evidence including the use of the polygraph and genetic tests; (C) Pre-trial discovery; (ii... regulations having the effect of law; (iii) Identifying competent laboratories that perform genetic tests as... transporting blood and other samples of genetic material, repeated testing when necessary, analysis of test...

45 CFR 304.20 - Availability and rate of Federal financial participation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... development of evidence including the use of the polygraph and genetic tests; (C) Pre-trial discovery; (ii... regulations having the effect of law; (iii) Identifying competent laboratories that perform genetic tests as... transporting blood and other samples of genetic material, repeated testing when necessary, analysis of test...

45 CFR 304.20 - Availability and rate of Federal financial participation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... development of evidence including the use of the polygraph and genetic tests; (C) Pre-trial discovery; (ii... regulations having the effect of law; (iii) Identifying competent laboratories that perform genetic tests as... transporting blood and other samples of genetic material, repeated testing when necessary, analysis of test...

Development and validation of a high-fidelity phonomicrosurgical trainer.

PubMed

Klein, Adam M; Gross, Jennifer

2017-04-01

To validate the use of a high-fidelity phonomicrosurgical trainer. A high-fidelity phonomicrosurgical trainer, based on a previously validated model by Contag et al., 1 was designed with multilayered vocal folds that more closely mimic the consistency of true vocal folds, containing intracordal lesions to practice phonomicrosurgical removal. A training module was developed to simulate the true phonomicrosurgical experience. A validation study with novice and expert surgeons was conducted. Novices and experts were instructed to remove the lesion from the synthetic vocal folds, and novices were given four training trials. Performances were measured by the amount of time spent and tissue injury (microflap, superficial, deep) to the vocal fold. An independent Student t test and Fisher exact tests were used to compare subjects. A matched-paired t test and Wilcoxon signed rank tests were used to compare novice performance on the first and fourth trials and assess for improvement. Experts completed the excision with less total errors than novices (P = .004) and made less injury to the microflap (P = .05) and superficial tissue (P = .003). Novices improved their performance with training, making less total errors (P = .002) and superficial tissue injuries (P = .02) and spending less time for removal (P = .002) after several practice trials. This high-fidelity phonomicrosurgical trainer has been validated for novice surgeons. It can distinguish between experts and novices; and after training, it helped to improve novice performance. N/A. Laryngoscope, 127:888-893, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Validity and Test-Retest Reliability of the TIVRE-Basket Test for the Determination of Aerobic Power in Elite Male Basketball Players.

PubMed

Vaquera, Alejandro; Villa, Jose G; Morante, Juan C; Thomas, Gavin; Renfree, Andrew J; Peters, Derek M

2016-02-01

The aims of this study were to (a) determine the relationship between performance on the court-based TIVRE-Basket test and peak aerobic power determined from a criterion laboratory-based incremental treadmill test and (b) to examine the test-retest reliability of the TIVRE-Basket test in elite male basketball players. To address aim 1, 36 elite male basketball players (age: 25.2 ± 4.7 years, weight: 94.1 ± 11.4 kg, height: 195.83 ± 9.6 cm) completed a graded treadmill exercise test and the TIVRE-Basket within 72 hours. The mean distance recorded during the TIVRE-Basket test was 4001.8 ± 176.4 m, and mean VO2 peak was 54.7 ± 2.8 ml · kg(-1) · min(-1), and the correlation between the 2 parameters was r = 0.824 (p ≤ 0.001). Linear regression analysis identified TIVRE-Basket distance (in meters) as the only unique predictor of VO2 peak in a single variable plus constant model: VO2 peak = 2.595 + (0.13 × TIVRE-Basket distance [in meters]). Performance on the TIVRE-Basket test accounted for 67.8% of the variance in VO2 peak (t = 8.466, p ≤ 0.001, 95% confidence interval: 0.01-0.016, SEE: 1.61). To address aim 2, 20 male basketball players (age: 26.7 ± 4.2 years, height: 1.94 ± 0.92 cm, weight: 94.0 ± 9.1 kg) performed the TIVRE-Basket test on 2 occasions. There was no significant difference in total distance covered between trial 1 (4138.8 ± 677.3 m) and trial 2 (4188.0 ± 648.8 m; t = 0.5798, p = 0.5688). Mean difference between trials was 49.2 ± 399.5 m, with an intraclass correlation coefficient of 0.85 suggesting a moderate level of reliability. Standardized typical error of measurement was 0.88%, representing a moderate degree of trial-to-trial error, and the Coefficient of Variation (CV) was 6.3%. The TIVRE-Basket test therefore represents a valid and moderately reliable court-based sport-specific test of aerobic power for use with individuals and teams of elite-level male basketball players. Future research is required to ascertain its validity and reliability in other basketball populations, for example, across age groups, at different levels of competition, in females and in different forms of the game, for example, wheelchair basketball.

Notes on testing equality and interval estimation in Poisson frequency data under a three-treatment three-period crossover trial.

PubMed

Lui, Kung-Jong; Chang, Kuang-Chao

2016-10-01

When the frequency of event occurrences follows a Poisson distribution, we develop procedures for testing equality of treatments and interval estimators for the ratio of mean frequencies between treatments under a three-treatment three-period crossover design. Using Monte Carlo simulations, we evaluate the performance of these test procedures and interval estimators in various situations. We note that all test procedures developed here can perform well with respect to Type I error even when the number of patients per group is moderate. We further note that the two weighted-least-squares (WLS) test procedures derived here are generally preferable to the other two commonly used test procedures in the contingency table analysis. We also demonstrate that both interval estimators based on the WLS method and interval estimators based on Mantel-Haenszel (MH) approach can perform well, and are essentially of equal precision with respect to the average length. We use a double-blind randomized three-treatment three-period crossover trial comparing salbutamol and salmeterol with a placebo with respect to the number of exacerbations of asthma to illustrate the use of these test procedures and estimators. © The Author(s) 2014.

Carbohydrate ingestion improves performance of a new reliable test of soccer performance.

PubMed

Currell, Kevin; Conway, Steve; Jeukendrup, Asker E

2009-02-01

The aim of the study was to investigate the reliability of a new test of soccer performance and evaluate the effect of carbohydrate (CHO) on soccer performance. Eleven university footballers were recruited and underwent 3 trials in a randomized order. Two of the trials involved ingesting a placebo beverage, and the other, a 7.5% maltodextrin solution. The protocol comprised a series of ten 6-min exercise blocks on an outdoor Astroturf pitch, separated by the performance of 2 of the 4 soccer-specific tests, making the protocol 90 min in duration. The intensity of the exercise was designed to be similar to the typical activity pattern during soccer match play. Participants performed skill tests of dribbling, agility, heading, and shooting throughout the protocol. The coefficients of variation for dribbling, agility, heading, and shooting were 2.2%, 1.2%, 7.0%, and 2.8%, respectively. The mean combined placebo scores were 42.4 +/- 2.7 s, 43.1 +/- 3.7 s, 210 +/- 34 cm, and 212 +/- 17 points for agility, dribbling, heading, and kicking, respectively. CHO ingestion led to a combined agility time of 41.5 +/- 0.8 s, for dribbling 41.7 +/- 3.5 s, 213 +/- 11 cm for heading, and 220 +/- 5 points for kicking accuracy. There was a significant improvement in performance for dribbling, agility, and shooting (p < .05) when CHO was ingested compared with placebo. In conclusion, the protocol is a reliable test of soccer performance, and ingesting CHO leads to an improvement in soccer performance.

The effects of amphetamine sensitization on conditioned inhibition during a Pavlovian-instrumental transfer task in rats.

PubMed

Shiflett, Michael W; Riccie, Meaghan; DiMatteo, RoseMarie

2013-11-01

Psychostimulant sensitization heightens behavioral and motivational responses to reward-associated stimuli; however, its effects on stimuli associated with reward absence are less understood. We examined whether amphetamine sensitization alters performance during Pavlovian-instrumental transfer (PIT) to conditioned excitors and inhibitors. We further sought to characterize the effects of amphetamine sensitization on learning versus performance by exposing rats to amphetamine prior to Pavlovian training or between training and test. Adult male Long-Evans rats were given conditioned inhibition (A+/AX-) and Pavlovian (B+) training, followed by variable-interval instrumental conditioning. Rats were sensitized to D-amphetamine (2 mg/kg daily injections for 7 days) or served as non-exposed controls. Rats were given a PIT test, in which they were presented with stimulus B alone or in compound with the conditioned inhibitor (BX). During the PIT test, control rats significantly reduced instrumental responding on BX trials (to approximately 50 % of responding to B). Amphetamine sensitization prior to Pavlovian conditioning increased lever pressing on BX trials and reduced lever pressing on B trials compared to controls. Amphetamine sensitization between training and test increased lever pressing on B and BX trials compared to controls. No effects of sensitization were observed on conditioned food cup approach. Amphetamine sensitization increases instrumental responding during PIT to a conditioned inhibitor by enhancing the excitation of conditioned stimuli and reducing the inhibition of conditioned inhibitors.

Executive Function Processes Predict Mobility Outcomes in Older Adults

PubMed Central

Gothe, Neha P.; Fanning, Jason; Awick, Elizabeth; Chung, David; Wójcicki, Thomas R.; Olson, Erin A.; Mullen, Sean P.; Voss, Michelle; Erickson, Kirk I.; Kramer, Arthur F.; McAuley, Edward

2013-01-01

BACKGROUND: There is growing evidence suggesting an association between cognitive function and physical performance in late life. This study examined the relationship between performance on executive function measures and subsequent mobility outcomes among community dwelling older adults across a 12-month randomized controlled exercise trial. DESIGN: Randomized controlled clinical trial SETTING: Champaign-Urbana, Illinois PARTICIPANTS: Community dwelling older adults (N = 179; Mage = 66.4) INTERVENTION: A 12-month exercise trial with two arms: an aerobic exercise group and a stretching and strengthening group MEASUREMENTS: Established cognitive tests of executive function including the flanker task, task switching and a dual task paradigm, and the Wisconsin card sort test. Mobility was assessed using the timed 8-foot up and go test and times to climb up and down a flight of stairs. METHODS: Participants completed the cognitive measures at baseline and the mobility measures at baseline and after 12 months of the intervention. Multiple regression analyses were conducted to determine whether baseline executive function predicted post-intervention functional performance after controlling for age, sex, education, cardiorespiratory fitness and baseline mobility levels. RESULTS: Our analyses revealed that selective baseline executive function measures, particularly performance on the flanker task (β’s =.15 to .17) and the Wisconsin card sort test (β’s =.11 to .16) consistently predicted mobility outcomes at month 12. The estimates were in the expected direction, such that better baseline performance on the executive function measures predicted better performance on the timed mobility tests independent of the intervention group. CONCLUSION: Executive functions of inhibitory control, mental set shifting and attentional flexibility were predictive of functional mobility. Given the literature associating mobility limitations with disability, morbidity, and mortality, these results are important for understanding the antecedents to poor mobility function that can be attenuated by well-designed interventions to improve cognitive performance. PMID:24521364

Validity and Reliability of Surface Electromyography Measurements from a Wearable Athlete Performance System

PubMed Central

Lynn, Scott K.; Watkins, Casey M.; Wong, Megan A.; Balfany, Katherine; Feeney, Daniel F.

2018-01-01

The Athos ® wearable system integrates surface electromyography (sEMG ) electrodes into the construction of compression athletic apparel. The Athos system reduces the complexity and increases the portability of collecting EMG data and provides processed data to the end user. The objective of the study was to determine the reliability and validity of Athos as compared with a research grade sEMG system. Twelve healthy subjects performed 7 trials on separate days (1 baseline trial and 6 repeated trials). In each trial subjects wore the wearable sEMG system and had a research grade sEMG system’s electrodes placed just distal on the same muscle, as close as possible to the wearable system’s electrodes. The muscles tested were the vastus lateralis (VL), vastus medialis (VM), and biceps femoris (BF). All testing was done on an isokinetic dynamometer. Baseline testing involved performing isometric 1 repetition maximum tests for the knee extensors and flexors and three repetitions of concentric-concentric knee flexion and extension at MVC for each testing speed: 60, 180, and 300 deg/sec. Repeated trials 2-7 each comprised 9 sets where each set included three repetitions of concentric-concentric knee flexion-extension. Each repeated trial (2-7) comprised one set at each speed and percent MVC (50%, 75%, 100%) combination. The wearable system and research grade sEMG data were processed using the same methods and aligned in time. The amplitude metrics calculated from the sEMG for each repetition were the peak amplitude, sum of the linear envelope, and 95th percentile. Validity results comprise two main findings. First, there is not a significant effect of system (Athos or research grade system) on the repetition amplitude metrics (95%, peak, or sum). Second, the relationship between torque and sEMG is not significantly different between Athos and the research grade system. For reliability testing, the variation across trials and averaged across speeds was 0.8%, 7.3%, and 0.2% higher for Athos from BF, VL and VM, respectively. Also, using the standard deviation of the MVC normalized repetition amplitude, the research grade system showed 10.7% variability while Athos showed 12%. The wearable technology (Athos) provides sEMG measures that are consistent with controlled, research grade technologies and data collection procedures. Key points Surface EMG embedded into athletic garments (Athos) had similar validity and reliability when compared with a research grade system There was no difference in the torque-EMG relationship between the two systems No statistically significant difference in reliability across 6 trials between the two systems The validity and reliability of Athos demonstrates the potential for sEMG to be applied in dynamic rehabilitation and sports settings PMID:29769821

Comparison of inter-trial recovery times for the determination of critical power and W' in cycling.

PubMed

Karsten, Bettina; Hopker, James; Jobson, Simon A; Baker, Jonathan; Petrigna, Luca; Klose, Andreas; Beedie, Christopher

2017-07-01

Critical Power (CP) and W' are often determined using multi-day testing protocols. To investigate this cumbersome testing method, the purpose of this study was to compare the differences between the conventional use of a 24-h inter-trial recovery time with those of 3 h and 30 min for the determination of CP and W'. 9 moderately trained cyclists performed an incremental test to exhaustion to establish the power output associated with the maximum oxygen uptake (p[Formula: see text] max ), and 3 protocols requiring time-to-exhaustion trials at a constant work-rate performed at 80%, 100% and 105% of p[Formula: see text] max. Design: Protocol A utilised 24-h inter-trial recovery (CP 24 /W' 24 ), protocol B utilised 3-h inter-trial recovery (CP 3 /W' 3 ), and protocol C used 30-min inter-trial recovery period (CP 0.5 /W' 0.5 ). CP and W' were calculated using the inverse time (1/t) versus power (P) relation (P = W'(1/t) + CP). 95% Limits of Agreement between protocol A and B were -9 to 15 W; -7.4 to 7.8 kJ (CP/W') and between protocol A and protocol C they were -27 to 22 W; -7.2 to 15.1 kJ (CP/W'). Compared to criterion protocol A, the average prediction error of protocol B was 2.5% (CP) and 25.6% (W'), whilst for protocol C it was 3.7% (CP) and 32.9% (W'). 3-h and 30-min inter-trial recovery time protocols provide valid methods of determining CP but not W' in cycling.

The efficacy of Australian essential oils for the treatment of head lice infestation in children: A randomised controlled trial.

PubMed

Greive, Kerryn A; Barnes, Tanya M

2018-05-01

The increase in resistance of head lice to neurotoxic pediculicides and public concern over their safety has led to an increase in alternative treatments, many of which are poorly researched or even untested. A multicentre, randomised, assessor-blind, parallel-group trial (Trial 1) was conducted to compare the safety and efficacy of a head lice treatment containing Australian eucalyptus oil and Leptospermum petersonii (EO/LP solution; applied thrice with 7-day intervals between applications) with a neurotoxic treatment containing pyrethrins and piperonyl butoxide (P/PB mousse; applied twice with a 7-day interval) in children. A single-blind, open trial (Trial 2) was conducted to assess the efficacy of EO/LP solution following a single application. In addition, skin irritancy and sensitisation tests using EO/LP solution were performed in adults and children. In vitro tests were performed to further assess the ovicidal and pediculicidal efficacy of EO/LP solution. EO/LP solution was found to be more than twice as effective in curing head lice infestation as P/PB mousse in per-protocol participants (Trial 1; 83% vs 36%, P < 0.0001), and was also found to be 100% pediculicidal following a single application (Trial 2). Adverse events were limited to transient itching, burning or stinging. Further skin testing with the EO/LP solution reported no irritation or sensitisation in adults, or irritation in children. In vitro exposure of lice and eggs to the EO/LP solution resulted in 100% mortality. The efficacy, safety and relative ease of use of the EO/LP solution make it a viable alternative in treating head lice. © 2017 Ego Pharmaceuticals Pty Ltd. Australasian Journal of Dermatology published by John Wiley & Sons, Ltd. on behalf of The Australasian College of Dermatologists.

Caffeine Ingestion Reverses the Circadian Rhythm Effects on Neuromuscular Performance in Highly Resistance-Trained Men

PubMed Central

Mora-Rodríguez, Ricardo; Pallarés, Jesús García; López-Samanes, Álvaro; Ortega, Juan Fernando; Fernández-Elías, Valentín E.

2012-01-01

Purpose To investigate whether caffeine ingestion counteracts the morning reduction in neuromuscular performance associated with the circadian rhythm pattern. Methods Twelve highly resistance-trained men underwent a battery of neuromuscular tests under three different conditions; i) morning (10:00 a.m.) with caffeine ingestion (i.e., 3 mg kg−1; AMCAFF trial); ii) morning (10:00 a.m.) with placebo ingestion (AMPLAC trial); and iii) afternoon (18:00 p.m.) with placebo ingestion (PMPLAC trial). A randomized, double-blind, crossover, placebo controlled experimental design was used, with all subjects serving as their own controls. The neuromuscular test battery consisted in the measurement of bar displacement velocity during free-weight full-squat (SQ) and bench press (BP) exercises against loads that elicit maximum strength (75% 1RM load) and muscle power adaptations (1 m s−1 load). Isometric maximum voluntary contraction (MVCLEG) and isometric electrically evoked strength of the right knee (EVOKLEG) were measured to identify caffeine's action mechanisms. Steroid hormone levels (serum testosterone, cortisol and growth hormone) were evaluated at the beginning of each trial (PRE). In addition, plasma norepinephrine (NE) and epinephrine were measured PRE and at the end of each trial following a standardized intense (85% 1RM) 6 repetitions bout of SQ (POST). Results In the PMPLAC trial, dynamic muscle strength and power output were significantly enhanced compared with AMPLAC treatment (3.0%–7.5%; p≤0.05). During AMCAFF trial, muscle strength and power output increased above AMPLAC levels (4.6%–5.7%; p≤0.05) except for BP velocity with 1 m s−1 load (p = 0.06). During AMCAFF, EVOKLEG and NE (a surrogate of maximal muscle sympathetic nerve activation) were increased above AMPLAC trial (14.6% and 96.8% respectively; p≤0.05). Conclusions These results indicate that caffeine ingestion reverses the morning neuromuscular declines in highly resistance-trained men, raising performance to the levels of the afternoon trial. Our electrical stimulation data, along with the NE values, suggest that caffeine increases neuromuscular performance having a direct effect in the muscle. PMID:22496767

Biochemical tests of placental function for assessment in pregnancy.

PubMed

Neilson, James P

2012-08-15

Biochemical tests of placental or feto-placental function were widely used in the 1960s and 1970s in high-risk pregnancies to try to predict, and thus try to avoid, adverse fetal outcome. To assess the effects of performing biochemical tests of placental function in high-risk, low-risk, or unselected pregnancies. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 May 2012). Controlled trials (randomized or 'quasi-randomized') that compare the use of biochemical tests of placental function in pregnancy with non-use. Trial quality was assessed and data were extracted by the review author. A single eligible trial of poor quality was identified. It involved 622 women with high-risk pregnancies who had had plasma (o)estriol estimations. Women were allocated to have their (o)estriol results revealed or concealed on the basis of hospital record number (with attendant risk of selection bias). There were no obvious differences in perinatal mortality (relative risk (RR) 0.88, 95% confidence interval (CI) 0.36 to 2.13) or planned delivery (RR 0.97, 95% CI 0.81 to 1.15) between the two groups. The available trial data do not support the use of (o)estriol estimation in high-risk pregnancies. The single small trial available does not have the power to exclude a beneficial effect but this is probably of historical interest since biochemical testing has been superseded by biophysical testing in antepartum fetal assessment.

Single-Trial Normalization for Event-Related Spectral Decomposition Reduces Sensitivity to Noisy Trials

PubMed Central

Grandchamp, Romain; Delorme, Arnaud

2011-01-01

In electroencephalography, the classical event-related potential model often proves to be a limited method to study complex brain dynamics. For this reason, spectral techniques adapted from signal processing such as event-related spectral perturbation (ERSP) – and its variant event-related synchronization and event-related desynchronization – have been used over the past 20 years. They represent average spectral changes in response to a stimulus. These spectral methods do not have strong consensus for comparing pre- and post-stimulus activity. When computing ERSP, pre-stimulus baseline removal is usually performed after averaging the spectral estimate of multiple trials. Correcting the baseline of each single-trial prior to averaging spectral estimates is an alternative baseline correction method. However, we show that this method leads to positively skewed post-stimulus ERSP values. We eventually present new single-trial-based ERSP baseline correction methods that perform trial normalization or centering prior to applying classical baseline correction methods. We show that single-trial correction methods minimize the contribution of artifactual data trials with high-amplitude spectral estimates and are robust to outliers when performing statistical inference testing. We then characterize these methods in terms of their time–frequency responses and behavior compared to classical ERSP methods. PMID:21994498

Accuracy of the Velotron ergometer and SRM power meter.

PubMed

Abbiss, C R; Quod, M J; Levin, G; Martin, D T; Laursen, P B

2009-02-01

The purpose of this study was to determine the accuracy of the Velotron cycle ergometer and the SRM power meter using a dynamic calibration rig over a range of exercise protocols commonly applied in laboratory settings. These trials included two sustained constant power trials (250 W and 414 W), two incremental power trials and three high-intensity interval power trials. To further compare the two systems, 15 subjects performed three dynamic 30 km performance time trials. The Velotron and SRM displayed accurate measurements of power during both constant power trials (<1% error). However, during high-intensity interval trials the Velotron and SRM were found to be less accurate (3.0%, CI=1.6-4.5% and -2.6%, CI=-3.2--2.0% error, respectively). During the dynamic 30 km time trials, power measured by the Velotron was 3.7+/-1.9% (CI=2.9-4.8%) greater than that measured by the SRM. In conclusion, the accuracy of the Velotron cycle ergometer and the SRM power meter appears to be dependent on the type of test being performed. Furthermore, as each power monitoring system measures power at various positions (i.e. bottom bracket vs. rear wheel), caution should be taken when comparing power across the two systems, particularly when power is variable.

Altered Running Economy Directly Translates to Altered Distance-Running Performance.

PubMed

Hoogkamer, Wouter; Kipp, Shalaya; Spiering, Barry A; Kram, Rodger

2016-11-01

Our goal was to quantify if small (1%-3%) changes in running economy quantitatively affect distance-running performance. Based on the linear relationship between metabolic rate and running velocity and on earlier observations that added shoe mass increases metabolic rate by ~1% per 100 g per shoe, we hypothesized that adding 100 and 300 g per shoe would slow 3000-m time-trial performance by 1% and 3%, respectively. Eighteen male sub-20-min 5-km runners completed treadmill testing, and three 3000-m time trials wearing control shoes and identical shoes with 100 and 300 g of discreetly added mass. We measured rates of oxygen consumption and carbon dioxide production and calculated metabolic rates for the treadmill tests, and we recorded overall running time for the time trials. Adding mass to the shoes significantly increased metabolic rate at 3.5 m·s by 1.11% per 100 g per shoe (95% confidence interval = 0.88%-1.35%). While wearing the control shoes, participants ran the 3000-m time trial in 626.1 ± 55.6 s. Times averaged 0.65% ± 1.36% and 2.37% ± 2.09% slower for the +100-g and +300-g shoes, respectively (P < 0.001). On the basis of a linear fit of all the data, 3000-m time increased 0.78% per added 100 g per shoe (95% confidence interval = 0.52%-1.04%). Adding shoe mass predictably degrades running economy and slows 3000-m time-trial performance proportionally. Our data demonstrate that laboratory-based running economy measurements can accurately predict changes in distance-running race performance due to shoe modifications.

Estimates of genetic parameters and environmental effects for measures of hunting performance in Finnish hounds.

PubMed

Liinamo, A E; Karjalainen, L; Ojala, M; Vilva, V

1997-03-01

Data from field trials of Finnish Hounds between 1988 and 1992 in Finland were used to estimate genetic parameters and environmental effects for measures of hunting performance using REML procedures and an animal model. The original data set included 28,791 field trial records from 5,666 dogs. Males and females had equal hunting performance, whereas experience acquired by age improved trial results compared with results for young dogs (P < .001). Results were mostly better on snow than on bare ground (P < .001), and testing areas, years, months, and their interactions affected results (P < .001). Estimates of heritabilities and repeatabilities were low for most of the 28 measures, mainly due to large residual variances. The highest heritabilities were for frequency of tonguing (h2 = .15), pursuit score (h2 = .13), tongue score (h2 = .13), ghost trailing score (h2 = .12), and merit and final score (both h2 = .11). Estimates of phenotypic and genetic correlations were positive and moderate or high for search scores, pursuit scores, and final scores but lower for other studied measures. The results suggest that, due to low heritabilities, evaluation of breeding values for Finnish Hounds with respect to their hunting ability should be based on animal model BLUP methods instead of mere performance testing. The evaluation system of field trials should also be revised for more reliability.

Publication and non-publication of drug trial results: a 10-year cohort of trials in Norwegian general practice.

PubMed

Brænd, Anja Maria; Straand, Jørund; Jakobsen, Rune Bruhn; Klovning, Atle

2016-04-11

Previously, we identified a 10-year cohort of protocols from applications to the Norwegian Medicines Agency 1998-2007, consisting of 196 drug trials in general practice. The aim of this study was to examine whether trial results were published and whether trial funding and conflicts of interest were reported. Cohort study of trials with systematic searches for published results. Clinical drug trials in Norwegian general practice. We performed systematic literature searches of MEDLINE, Embase and CENTRAL to identify publications originating from each trial using characteristics such as test drug, comparator and patient groups as search terms. When no publication was identified, we contacted trial sponsors for information regarding trial completion and reference to any publications. We determined the frequency of publication of trial results and trial characteristics associated with publication of results. Of the 196 trials, 5 were never started. Of the remaining 191 trials, 71% had results published in a journal, 11% had results publicly available elsewhere and 18% of trials had no results available. Publication was more common among trials with an active comparator drug (χ(2) test, p=0.040), with a larger number of patients (total sample size≥median, p=0.010) and with a longer trial period (duration≥median, p=0.025). Trial funding was reported in 85% of publications and increased over time, as did reporting of conflicts of interest among authors. Among the 134 main journal articles from the trials, 60% presented statistically significant results for the investigational drug, and the conclusion of the article was favourable towards the test drug in 78% of papers. We did not identify any journal publication of results for 29% of the general practice drug trials. Trials with an active comparator, larger and longer trials were more likely to be published. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The making of indigenous vascular prosthesis

PubMed Central

Unnikrishnan, Madathipat; Viswanathan, Sidharth; Balasubramaniam, K.; Muraleedharan, C.V.; Lal, Arthur Vijayan; Mohanan, P.V.; Mohanty, Meera; Kapilamoorthy, Tirur Raman

2016-01-01

Background & objectives: Vascular illnesses are on the rise in India, due to increase in lifestyle diseases and demographic transition, requiring intervention to save life, organ or limbs using vascular prosthesis. The aim of this study was to develop indigenous large diameter vascular graft for treatment of patients with vascular pathologies. Methods: The South India Textile Research Association, at Coimbatore, Tamil Nadu, India, developed seamless woven polyester (Polyethylene terephthalate) graft at its research wing. Further characterization and testing followed by clinical trials were conducted at Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. Fifteen in vivo experiments were carried out in 1992-1994 in pigs as animal model. Controlled (phase I) clinical trial in ten patients was performed along with control graft. Thereafter, phase II trial involved 22 patients who underwent multi-centre clinical trial in four centres across India. Results: Laboratory testing showed that polyester graft was non-toxic, non-leeching and non-haemolytic with preserved long-term quality, further confirming in pigs by implanting in thoracic aorta, comparable to control Dacron grafts. Perigraft incorporation and smooth neointima formation which are prime features of excellent healing characteristics, were noted at explantation at planned intervals. Subsequently in the phase I and II clinical trials, all patients had excellent recovery without mortality or device-related adverse events. Patients receiving the test graft were followed up for 10 and 5 years, respectively. Serial clinical, duplex scans and CT angiograms performed periodically confirmed excellent graft performance. Interpretation & conclusions: Indigenously developed Chitra vascular graft was comparable to commercially available Dacron graft, ready for clinical use at affordable cost to patients as against costly imported grafts. PMID:27748302

Experimental masseter muscle pain alters jaw-neck motor strategy.

PubMed

Wiesinger, B; Häggman-Henrikson, B; Hellström, F; Wänman, A

2013-08-01

A functional integration between the jaw and neck regions has been demonstrated during normal jaw function. The effect of masseter muscle pain on this integrated motor behaviour in man is unknown. The aim of this study was to investigate the effect of induced masseter muscle pain on jaw-neck movements during a continuous jaw opening-closing task. Sixteen healthy men performed continuous jaw opening-closing movements to a target position, defined as 75% of the maximum jaw opening. Each subject performed two trials without pain (controls) and two trials with masseter muscle pain, induced with hypertonic saline as a single injection. Simultaneous movements of the mandible and the head were registered with a wireless optoelectronic three-dimensional recording system. Differences in movement amplitudes between trials were analysed with Friedman's test and corrected Wilcoxon matched pairs test. The head movement amplitudes were significantly larger during masseter muscle pain trials compared with control. Jaw movement amplitudes did not differ significantly between any of the trials after corrected Wilcoxon tests. The ratio between head and jaw movement amplitudes was significantly larger during the first pain trial compared with control. Experimental masseter muscle pain in humans affected integrated jaw-neck movements by increasing the neck component during continuous jaw opening-closing tasks. The findings indicate that pain can alter the strategy for jaw-neck motor control, which further underlines the functional integration between the jaw and neck regions. This altered strategy may have consequences for development of musculoskeletal pain in the jaw and neck regions. © 2012 European Federation of International Association for the Study of Pain Chapters.

Competition between landmarks in spatial learning: the role of proximity to the goal.

PubMed

Chamizo, V D; Manteiga, R D; Rodrigo, T; Mackintosh, N J

2006-01-10

In two experiments, rats were trained to find a hidden platform in a Morris pool in the presence of two landmarks. Landmark B was present on all training trials, on half the trials accompanied by landmark A, on the remainder by landmark C. For rats in Group Bn, B was near the location of the platform; for those in Group Bf, B was far from the platform. Group Bn performed better than Group Bf on test trials to B alone, but significantly worse on test trials to a new configuration formed by A and C. Thus, the spatial proximity of B to the platform affected not only how well it could be used to locate the platform, but also its ability to prevent learning about other landmarks.

Sexual Orientation-Related Differences in Virtual Spatial Navigation and Spatial Search Strategies.

PubMed

Rahman, Qazi; Sharp, Jonathan; McVeigh, Meadhbh; Ho, Man-Ling

2017-07-01

Spatial abilities are generally hypothesized to differ between men and women, and people with different sexual orientations. According to the cross-sex shift hypothesis, gay men are hypothesized to perform in the direction of heterosexual women and lesbian women in the direction of heterosexual men on cognitive tests. This study investigated sexual orientation differences in spatial navigation and strategy during a virtual Morris water maze task (VMWM). Forty-four heterosexual men, 43 heterosexual women, 39 gay men, and 34 lesbian/bisexual women (aged 18-54 years) navigated a desktop VMWM and completed measures of intelligence, handedness, and childhood gender nonconformity (CGN). We quantified spatial learning (hidden platform trials), probe trial performance, and cued navigation (visible platform trials). Spatial strategies during hidden and probe trials were classified into visual scanning, landmark use, thigmotaxis/circling, and enfilading. In general, heterosexual men scored better than women and gay men on some spatial learning and probe trial measures and used more visual scan strategies. However, some differences disappeared after controlling for age and estimated IQ (e.g., in visual scanning heterosexual men differed from women but not gay men). Heterosexual women did not differ from lesbian/bisexual women. For both sexes, visual scanning predicted probe trial performance. More feminine CGN scores were associated with lower performance among men and greater performance among women on specific spatial learning or probe trial measures. These results provide mixed evidence for the cross-sex shift hypothesis of sexual orientation-related differences in spatial cognition.

The simplest acquisition protocol is sometimes the best protocol: performing and learning a 1:2 bimanual coordination task.

PubMed

Panzer, Stefan; Kennedy, Deanna; Wang, Chaoyi; Shea, Charles H

2018-02-01

An experiment was conducted to determine if the performance and learning of a multi-frequency (1:2) coordination pattern between the limbs are enhanced when a model is provided prior to each acquisition trial. Research has indicated very effective performance of a wide variety of bimanual coordination tasks when Lissajous plots with goal templates are provided, but this research has also found that participants become dependent on this information and perform quite poorly when it is withdrawn. The present experiment was designed to test three forms of modeling (Lissajous with template, Lissajous without template, and limb model), but in each situations, the model was presented prior to practice and not available during the performance of the task. This was done to decrease dependency on the model and increase the development of an internal reference of correctness that could be applied on test trials. A control condition was also collected, where a metronome was used to guide the movement. Following less than 7 min of practice, participants in the three modeling conditions performed the first test block very effectively; however, performance of the control condition was quite poor. Note that Test 1 was performed under the same conditions as used during acquisition. Test 2 was conducted with no augmented information provided prior to or during the performance of the task. Only participants in the limb model condition were able to maintain performance on Test 2. The findings suggest that a very simple intuitive display can provide the necessary information to form an effective internal representation of the coordination pattern which can be used guide performance when the augmented display is withdrawn.

The Neural Mechanisms Underlying the Decision to Rest in the Presence of Fatigue: A Magnetoencephalography Study

PubMed Central

Ishii, Akira; Tanaka, Masaaki; Watanabe, Yasuyoshi

2014-01-01

Adequate rest is essential to avoid fatigue and disruption of homeostasis. However, the neural mechanisms underlying the decision to rest are not well understood. In the present study, we aimed to clarify the neural mechanisms of this decision-making process using magnetoencephalography. Fifteen healthy volunteers participated in decision and control experiments performed in a cross-over fashion. In the decision experiment, participants performed 1,200 reverse Stroop test trials and were intermittently asked to decide whether they wanted to take a rest or continue. In the control experiments, participants performed 1,200 reverse Stroop test trials and were instructed to press a response button intermittently without making any decision. Changes in oscillatory brain activity were assessed using a narrow-band adaptive spatial filtering method. The levels of decrease in theta (4–8 Hz) band power in left Brodmann's area (BA) 31, alpha (8–13 Hz) band power in left BA 10 and BA 9, and beta (13–25 Hz) band power in right BA 46 and left BA 10 were greater in trials when the participant opted to rest (rest trials) than those in control trials. The decrease in theta band power in BA 31 in the rest trials was positively correlated with the subjective level of fatigue after the decision experiment. These results demonstrated that the dorsolateral prefrontal cortex, frontal pole, and posterior cingulate cortex play a role in the decision to rest in the presence of fatigue. These findings may help clarify the neural mechanisms underlying fatigue and fatigue-related problems. PMID:25303465

Energy system contribution in a maximal incremental test: correlations with pacing and overall performance in a 10-km running trial.

PubMed

Damasceno, M V; Pasqua, L A; Lima-Silva, A E; Bertuzzi, R

2015-11-01

This study aimed to verify the association between the contribution of energy systems during an incremental exercise test (IET), pacing, and performance during a 10-km running time trial. Thirteen male recreational runners completed an incremental exercise test on a treadmill to determine the respiratory compensation point (RCP), maximal oxygen uptake (V˙O2max), peak treadmill speed (PTS), and energy systems contribution; and a 10-km running time trial (T10-km) to determine endurance performance. The fractions of the aerobic (WAER) and glycolytic (WGLYCOL) contributions were calculated for each stage based on the oxygen uptake and the oxygen energy equivalents derived by blood lactate accumulation, respectively. Total metabolic demand (WTOTAL) was the sum of these two energy systems. Endurance performance during the T10-km was moderately correlated with RCP, V˙O2max and PTS (P<@0.05), and moderate-to-highly correlated with WAER, WGLYCOL, and WTOTAL (P<0.05). In addition, WAER, WGLYCOL, and WTOTAL were also significantly correlated with running speed in the middle (P<0.01) and final (P<0.01) sections of the T10-km. These findings suggest that the assessment of energy contribution during IET is potentially useful as an alternative variable in the evaluation of endurance runners, especially because of its relationship with specific parts of a long-distance race.

Thermal comfort of aeroplane seats: influence of different seat materials and the use of laboratory test methods.

PubMed

Bartels, Volkmar T

2003-07-01

This study determined the influence of different cover and cushion materials on the thermal comfort of aeroplane seats. Different materials as well as ready made seats were investigated by the physiological laboratory test methods Skin Model and seat comfort tester. Additionally, seat trials with human test subjects were performed in a climatic chamber. Results show that a fabric cover produces a considerably higher sweat transport than leather. A three-dimensional knitted spacer fabric turns out to be the better cushion alternative in comparison to a moulded foam pad. Results from the physiological laboratory test methods nicely correspond to the seat trials with human test subjects.

The effect of bronchodilators on forced vital capacity measurement in patients with idiopathic pulmonary fibrosis

PubMed Central

Assayag, Deborah; Vittinghoff, Eric; Ryerson, Christopher J.; Cocconcelli, Elisabetta; Tonelli, Roberto; Hu, Xiaowen; Elicker, Brett M.; Golden, Jeffrey A.; Jones, Kirk D.; King, Talmadge E.; Koth, Laura L.; Lee, Joyce S.; Ley, Brett; Shum, Anthony K.; Wolters, Paul J.; Ryu, Jay H.; Collard, Harold R.

2015-01-01

Background Forced vital capacity (FVC) is a key measure of disease severity in patients with idiopathic pulmonary fibrosis (IPF) and is an important clinical trial endpoint. We hypothesize that reversible airflow limitation co-exists in a subgroup of patients with IPF, and that bronchodilator use will improve the performance characteristics of FVC. Methods IPF patients with pre and post-bronchodilator spirometry testing performed were identified from two tertiary referral cohorts. The difference between pre and post-bronchodilator FVC (intra-test difference) was calculated. The test characteristics of pre and post-bronchodilator FVC change over time (inter-test difference) were assessed in patients with sequential spirometry, and were used to generate sample size estimates for hypothetical clinical trials using change in FVC as the primary endpoint. Results There were 551 patients, contributing 967 unique spirometry tests. The mean intra-test increase in FVC with bronchodilator use was 0.04 liters (2.71 vs. 2.75 liters, p <0.001). Reversible airflow limitation (increase in FEV1 or FVC of ≥12% and ≥200 milliliters) occurred in 9.1% of patients. The inter-test difference in change in FVC over time were equivalent for pre and post-bronchodilator (p = 0.65), leading to similar sample size estimates in a hypothetical clinical trial using change in FVC as the primary endpoint. Conclusion Approximately one in ten patients with IPF has physiological evidence of reversible airflow limitation, and bronchodilator use in these patients may improve the assessment of disease progression based on FVC change over time. Bronchodilator use does not appear to meaningfully impact the precision of FVC as an endpoint in clinical trials. PMID:26140806

The development of automaticity in short-term memory search: Item-response learning and category learning.

PubMed

Cao, Rui; Nosofsky, Robert M; Shiffrin, Richard M

2017-05-01

In short-term-memory (STM)-search tasks, observers judge whether a test probe was present in a short list of study items. Here we investigated the long-term learning mechanisms that lead to the highly efficient STM-search performance observed under conditions of consistent-mapping (CM) training, in which targets and foils never switch roles across trials. In item-response learning, subjects learn long-term mappings between individual items and target versus foil responses. In category learning, subjects learn high-level codes corresponding to separate sets of items and learn to attach old versus new responses to these category codes. To distinguish between these 2 forms of learning, we tested subjects in categorized varied mapping (CV) conditions: There were 2 distinct categories of items, but the assignment of categories to target versus foil responses varied across trials. In cases involving arbitrary categories, CV performance closely resembled standard varied-mapping performance without categories and departed dramatically from CM performance, supporting the item-response-learning hypothesis. In cases involving prelearned categories, CV performance resembled CM performance, as long as there was sufficient practice or steps taken to reduce trial-to-trial category-switching costs. This pattern of results supports the category-coding hypothesis for sufficiently well-learned categories. Thus, item-response learning occurs rapidly and is used early in CM training; category learning is much slower but is eventually adopted and is used to increase the efficiency of search beyond that available from item-response learning. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Exploration of task performance tests in a physics laboratory

NASA Astrophysics Data System (ADS)

Liu, Dan; El Turkey, Houssein

2017-11-01

In this article, we investigate the implementation of task performance tests in an undergraduate physics laboratory. Two performance tests were carried out over two semesters using the task of building a DC circuit. The first implementation in Spring 2014 had certain concerns such as the privacy of students’ testing and their ‘trial and error’ attempts. These concerns were addressed in Fall 2015 through implementing a second performance test. The second implementation was administered differently but the content of the two tests was the same. We discuss the validity of both implementations and present the correlation (or lack of) between the time that students needed to complete the tests and their grades from a paper-based laboratory assessment method.

Cycling performance is superior for time-to-exhaustion versus time-trial in endurance laboratory tests.

PubMed

Coakley, Sarah L; Passfield, Louis

2018-06-01

Time-to-exhaustion (TTE) trials are used in a laboratory setting to measure endurance performance. However, there is some concern with their ecological validity compared with time-trials (TT). Consequently, we aimed to compare cycling performance in TTE and TT where the duration of the trials was matched. Seventeen trained male cyclists completed three TTE trials at 80, 100 and 105% of maximal aerobic power (MAP). On a subsequent visit they performed three TT over the same duration as the TTE. Participants were blinded to elapsed time, power output, cadence and heart rate (HR). Average TTE was 865 ± 345 s, 165 ± 98 s and 117 ± 45 s for the 80, 100 and 105% trials respectively. Average power output was higher for TTE (294 ± 44 W) compared to TT (282 ± 43 W) at 80% MAP (P < 0.01), but not at 100 and 105% MAP (P > 0.05). There was no difference in cadence, HR, or RPE for any trial (P > 0.05). Critical power (CP) was also higher when derived from TTE compared to TT (P < 0.01). It is concluded that TTE results in a higher average power output compared to TT at 80% MAP. When determining CP, TTE rather than TT protocols appear superior.

Acquisition of Motor and Cognitive Skills through Repetition in Typically Developing Children

PubMed Central

Magallón, Sara; Narbona, Juan; Crespo-Eguílaz, Nerea

2016-01-01

Background Procedural memory allows acquisition, consolidation and use of motor skills and cognitive routines. Automation of procedures is achieved through repeated practice. In children, improvement in procedural skills is a consequence of natural neurobiological development and experience. Methods The aim of the present research was to make a preliminary evaluation and description of repetition-based improvement of procedures in typically developing children (TDC). Ninety TDC children aged 6–12 years were asked to perform two procedural learning tasks. In an assembly learning task, which requires predominantly motor skills, we measured the number of assembled pieces in 60 seconds. In a mirror drawing learning task, which requires more cognitive functions, we measured time spent and efficiency. Participants were tested four times for each task: three trials were consecutive and the fourth trial was performed after a 10-minute nonverbal interference task. The influence of repeated practice on performance was evaluated by means of the analysis of variance with repeated measures and the paired-sample test. Correlation coefficients and simple linear regression test were used to examine the relationship between age and performance. Results TDC achieved higher scores in both tasks through repetition. Older children fitted more pieces than younger ones in assembling learning and they were faster and more efficient at the mirror drawing learning task. Conclusions These findings indicate that three consecutive trials at a procedural task increased speed and efficiency, and that age affected basal performance in motor-cognitive procedures. PMID:27384671

Acquisition of Motor and Cognitive Skills through Repetition in Typically Developing Children.

PubMed

Magallón, Sara; Narbona, Juan; Crespo-Eguílaz, Nerea

2016-01-01

Procedural memory allows acquisition, consolidation and use of motor skills and cognitive routines. Automation of procedures is achieved through repeated practice. In children, improvement in procedural skills is a consequence of natural neurobiological development and experience. The aim of the present research was to make a preliminary evaluation and description of repetition-based improvement of procedures in typically developing children (TDC). Ninety TDC children aged 6-12 years were asked to perform two procedural learning tasks. In an assembly learning task, which requires predominantly motor skills, we measured the number of assembled pieces in 60 seconds. In a mirror drawing learning task, which requires more cognitive functions, we measured time spent and efficiency. Participants were tested four times for each task: three trials were consecutive and the fourth trial was performed after a 10-minute nonverbal interference task. The influence of repeated practice on performance was evaluated by means of the analysis of variance with repeated measures and the paired-sample test. Correlation coefficients and simple linear regression test were used to examine the relationship between age and performance. TDC achieved higher scores in both tasks through repetition. Older children fitted more pieces than younger ones in assembling learning and they were faster and more efficient at the mirror drawing learning task. These findings indicate that three consecutive trials at a procedural task increased speed and efficiency, and that age affected basal performance in motor-cognitive procedures.

Dietary tyrosine benefits cognitive and psychomotor performance during body cooling.

PubMed

O'Brien, Catherine; Mahoney, Caroline; Tharion, William J; Sils, Ingrid V; Castellani, John W

2007-02-28

Supplemental tyrosine is effective at limiting cold-induced decreases in working memory, presumably by augmenting brain catecholamine levels, since tyrosine is a precursor for catecholamine synthesis. The effectiveness of tyrosine for preventing cold-induced decreases in physical performance has not been examined. This study evaluated the effect of tyrosine supplementation on cognitive, psychomotor, and physical performance following a cold water immersion protocol that lowered body core temperature. Fifteen subjects completed a control trial (CON) in warm (35 degrees C) water and two cold water trials, each spaced a week apart. Subjects ingested an energy bar during each trial; on one cold trial (TYR) the bar contained tyrosine (300 mg/kg body weight), and on the other cold trial (PLB) and on CON the bar contained no tyrosine. Following each water immersion, subjects completed a battery of performance tasks in a cold air (10 degrees C) chamber. Core temperature was lower (p=0.0001) on PLB and TYR (both 35.5+/-0.6 degrees C) than CON (37.1+/-0.3 degrees C). On PLB, performance on a Match-to-Sample task decreased 18% (p=0.02) and marksmanship performance decreased 14% (p=0.002), compared to CON, but there was no difference between TYR and CON. Step test performance decreased by 11% (p=0.0001) on both cold trials, compared to CON. These data support previous findings that dietary tyrosine supplementation is effective for mitigating cold-induced cognitive performance such as working memory, even with reduced core temperature, and extends those findings to include the psychomotor task of marksmanship.

Whole body vibration for older persons: an open randomized, multicentre, parallel, clinical trial

PubMed Central

2011-01-01

Background Institutionalized older persons have a poor functional capacity. Including physical exercise in their routine activities decreases their frailty and improves their quality of life. Whole-body vibration (WBV) training is a type of exercise that seems beneficial in frail older persons to improve their functional mobility, but the evidence is inconclusive. This trial will compare the results of exercise with WBV and exercise without WBV in improving body balance, muscle performance and fall prevention in institutionalized older persons. Methods/Design An open, multicentre and parallel randomized clinical trial with blinded assessment. 160 nursing home residents aged over 65 years and of both sexes will be identified to participate in the study. Participants will be centrally randomised and allocated to interventions (vibration or exercise group) by telephone. The vibration group will perform static/dynamic exercises (balance and resistance training) on a vibratory platform (Frequency: 30-35 Hz; Amplitude: 2-4 mm) over a six-week training period (3 sessions/week). The exercise group will perform the same exercise protocol but without a vibration stimuli platform. The primary outcome measure is the static/dynamic body balance. Secondary outcomes are muscle strength and, number of new falls. Follow-up measurements will be collected at 6 weeks and at 6 months after randomization. Efficacy will be analysed on an intention-to-treat (ITT) basis and 'per protocol'. The effects of the intervention will be evaluated using the "t" test, Mann-Witney test, or Chi-square test, depending on the type of outcome. The final analysis will be performed 6 weeks and 6 months after randomization. Discussion This study will help to clarify whether WBV training improves body balance, gait mobility and muscle strength in frail older persons living in nursing homes. As far as we know, this will be the first study to evaluate the efficacy of WBV for the prevention of falls. Trial Registration ClinicalTrials.gov: NCT01375790 PMID:22192313

The effects of salmeterol on power output in nonasthmatic athletes.

PubMed

McDowell, S L; Fleck, S J; Storms, W W

1997-04-01

Salmeterol xinafoate is a new aerosol inhalant that is used in the treatment of asthma. It is currently banned by the International Olympic Committee because of the concern that it may lend an unfair competitive advantage to the user. The purpose of this study was to determine whether salmeterol improves short-term anaerobic performance in elite nonasthmatic track cyclists. Eleven elite track cyclists volunteered to perform a 30-second all-out cycle ergometer test 3 hours after receiving either 42 micrograms of salmeterol xinafoate or placebo applied in a double-blind crossover procedure. During the ergometer test, peak power output, total work, time to peak power, and percent fatigue (decline in power output) were measured. Pulmonary measurements were also taken before and at various time points after inhalation and the ergometer test. A methacholine challenge was administered to each subject before participation in the study to ensure that none of the subjects had any reactive airway diseases. There were no significant differences (p > 0.05) between the placebo and salmeterol trials for peak power output, total work performed during the 30-second test, percent fatigue, and time to peak power. No differences between trials were observed for the pulmonary function test variables at any of the time points. Blood lactate concentrations before and after administration of drug or placebo were also not significantly different between trials. Additionally, salmeterol did not affect the maximal heart rate achieved during the test as compared with the placebo. Short-term salmeterol use within the prescribed dosage was not shown to increase short-term power output in nonasthmatic cyclists.

Effect of alternating postures on cognitive performance for healthy people performing sedentary work.

PubMed

Schwartz, Bernhard; Kapellusch, Jay M; Schrempf, Andreas; Probst, Kathrin; Haller, Michael; Baca, Arnold

2018-06-01

Prolonged sitting is a risk factor for several diseases and the prevalence of worksite-based interventions such as sit-to-stand workstations is increasing. Although their impact on sedentary behaviour has been regularly investigated, the effect of working in alternating body postures on cognitive performance is unclear. To address this uncertainty, 45 students participated in a two-arm, randomised controlled cross-over trial under laboratory conditions. Subjects executed validated cognitive tests (working speed, reaction time, concentration performance) either in sitting or alternating working postures on two separate days (ClinicalTrials.gov Identifier: NCT02863731). MANOVA results showed no significant difference in cognitive performance between trials executed in alternating, standing or sitting postures. Perceived workload did not differ between sitting and alternating days. Repeated measures ANOVA revealed significant learning effects regarding concentration performance and working speed for both days. These results suggest that working posture did not affect cognitive performance in the short term. Practitioner Summary: Prior reports indicated health-related benefits based on alternated (sit/stand) body postures. Nevertheless, their effect on cognitive performance is unknown. This randomised controlled trial showed that working in alternating body postures did not influence reaction time, concentration performance, working speed or workload perception in the short term.

3-D localization of virtual sound sources: effects of visual environment, pointing method, and training.

PubMed

Majdak, Piotr; Goupell, Matthew J; Laback, Bernhard

2010-02-01

The ability to localize sound sources in three-dimensional space was tested in humans. In Experiment 1, naive subjects listened to noises filtered with subject-specific head-related transfer functions. The tested conditions included the pointing method (head or manual pointing) and the visual environment (VE; darkness or virtual VE). The localization performance was not significantly different between the pointing methods. The virtual VE significantly improved the horizontal precision and reduced the number of front-back confusions. These results show the benefit of using a virtual VE in sound localization tasks. In Experiment 2, subjects were provided with sound localization training. Over the course of training, the performance improved for all subjects, with the largest improvements occurring during the first 400 trials. The improvements beyond the first 400 trials were smaller. After the training, there was still no significant effect of pointing method, showing that the choice of either head- or manual-pointing method plays a minor role in sound localization performance. The results of Experiment 2 reinforce the importance of perceptual training for at least 400 trials in sound localization studies.

Comparison of Critical Power and W' Derived From 2 or 3 Maximal Tests.

PubMed

Simpson, Len Parker; Kordi, Mehdi

2017-07-01

Typically, accessing the asymptote (critical power; CP) and curvature constant (W') parameters of the hyperbolic power-duration relationship requires multiple constant-power exhaustive-exercise trials spread over several visits. However, more recently single-visit protocols and personal power meters have been used. This study investigated the practicality of using a 2-trial, single-visit protocol in providing reliable CP and W' estimates. Eight trained cyclists underwent 3- and 12-min maximal-exercise trials in a single session to derive (2-trial) CP and W' estimates. On a separate occasion a 5-min trial was performed, providing a 3rd trial to calculate (3-trial) CP and W'. There were no differences in CP (283 ± 66 vs 282 ± 65 W) or W' (18.72 ± 6.21 vs 18.27 ± 6.29 kJ) obtained from either the 2-trial or 3-trial method, respectively. After 2 familiarization sessions (completing a 3- and a 12-min trial on both occasions), both CP and W' remained reliable over additional separate measurements. The current study demonstrates that after 2 familiarization sessions, reliable CP and W' parameters can be obtained from trained cyclists using only 2 maximal-exercise trials. These results offer practitioners a practical, time-efficient solution for incorporating power-duration testing into applied athlete support.

Validation of a modification to Performance-Tested Method 070601: Reveal Listeria Test for detection of Listeria spp. in selected foods and selected environmental samples.

PubMed

Alles, Susan; Peng, Linda X; Mozola, Mark A

2009-01-01

A modification to Performance-Tested Method (PTM) 070601, Reveal Listeria Test (Reveal), is described. The modified method uses a new media formulation, LESS enrichment broth, in single-step enrichment protocols for both foods and environmental sponge and swab samples. Food samples are enriched for 27-30 h at 30 degrees C and environmental samples for 24-48 h at 30 degrees C. Implementation of these abbreviated enrichment procedures allows test results to be obtained on a next-day basis. In testing of 14 food types in internal comparative studies with inoculated samples, there was a statistically significant difference in performance between the Reveal and reference culture [U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA/BAM) or U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS)] methods for only a single food in one trial (pasteurized crab meat) at the 27 h enrichment time point, with more positive results obtained with the FDA/BAM reference method. No foods showed statistically significant differences in method performance at the 30 h time point. Independent laboratory testing of 3 foods again produced a statistically significant difference in results for crab meat at the 27 h time point; otherwise results of the Reveal and reference methods were statistically equivalent. Overall, considering both internal and independent laboratory trials, sensitivity of the Reveal method relative to the reference culture procedures in testing of foods was 85.9% at 27 h and 97.1% at 30 h. Results from 5 environmental surfaces inoculated with various strains of Listeria spp. showed that the Reveal method was more productive than the reference USDA-FSIS culture procedure for 3 surfaces (stainless steel, plastic, and cast iron), whereas results were statistically equivalent to the reference method for the other 2 surfaces (ceramic tile and sealed concrete). An independent laboratory trial with ceramic tile inoculated with L. monocytogenes confirmed the effectiveness of the Reveal method at the 24 h time point. Overall, sensitivity of the Reveal method at 24 h relative to that of the USDA-FSIS method was 153%. The Reveal method exhibited extremely high specificity, with only a single false-positive result in all trials combined for overall specificity of 99.5%.

Negative mood and mind wandering increase long-range temporal correlations in attention fluctuations.

PubMed

Irrmischer, Mona; van der Wal, C Natalie; Mansvelder, Huibert D; Linkenkaer-Hansen, Klaus

2018-01-01

There is growing evidence that the intermittent nature of mind wandering episodes and mood have a pronounced influence on trial-to-trial variability in performance. Nevertheless, the temporal dynamics and significance of such lapses in attention remains inadequately understood. Here, we hypothesize that the dynamics of fluctuations in sustained attention between external and internal sources of information obey so-called critical-state dynamics, characterized by trial-to-trial dependencies with long-range temporal correlations. To test this, we performed behavioral investigations measuring reaction times in a visual sustained attention task and cued introspection in probe-caught reports of mind wandering. We show that trial-to-trial variability in reaction times exhibit long-range temporal correlations in agreement with the criticality hypothesis. Interestingly, we observed the fastest responses in subjects with the weakest long-range temporal correlations and show the vital effect of mind wandering and bad mood on this response variability. The implications of these results stress the importance of future research to increase focus on behavioral variability.

Negative mood and mind wandering increase long-range temporal correlations in attention fluctuations

PubMed Central

van der Wal, C. Natalie; Mansvelder, Huibert D.; Linkenkaer-Hansen, Klaus

2018-01-01

There is growing evidence that the intermittent nature of mind wandering episodes and mood have a pronounced influence on trial-to-trial variability in performance. Nevertheless, the temporal dynamics and significance of such lapses in attention remains inadequately understood. Here, we hypothesize that the dynamics of fluctuations in sustained attention between external and internal sources of information obey so-called critical-state dynamics, characterized by trial-to-trial dependencies with long-range temporal correlations. To test this, we performed behavioral investigations measuring reaction times in a visual sustained attention task and cued introspection in probe-caught reports of mind wandering. We show that trial-to-trial variability in reaction times exhibit long-range temporal correlations in agreement with the criticality hypothesis. Interestingly, we observed the fastest responses in subjects with the weakest long-range temporal correlations and show the vital effect of mind wandering and bad mood on this response variability. The implications of these results stress the importance of future research to increase focus on behavioral variability. PMID:29746529

Additional Smooth and Rough Water Trials of SKI-CAT.

DTIC Science & Technology

1981-08-01

REPORT & PERIOD COVERED ADDITIONAL SMOOTH AND ROUGH WATER TRIALS OF FINAL SKI- CAT S. PERFORMING ORO. REPORT NUMSER 7. AUTHOR() I. CONTRACT OR GRANT NUMUr...Identif by bloc membe) ’ " -Further tests of SKI- CAT were made in smooth and rough water. Smooth water results confirmed the performance results of...reductions in the accelerations and motions of SKI- CAT over against the head seasreut DD , +A ,3 1473 EDITION OF I NOVS IS OBSOLETE UNCIbSJFIED SIME 0102-014

Employment Standards for Australian Urban Firefighters: Part 4: Physical Aptitude Tests and Standards.

PubMed

Fullagar, Hugh H K; Sampson, John A; Mott, Brendan J; Burdon, Catriona A; Taylor, Nigel A S; Groeller, Herbert

2015-10-01

Firefighter physical aptitude tests were administered to unskilled subjects and operational firefighters to evaluate the impact that testing bias associated with gender, age, activity-specific skills, or task familiarity may have upon establishing performance thresholds. These tests were administered in sequence, simulating hazmat incidents, ventilation fan carriage (stairs), motor-vehicle rescues, bushfire incidents, fire attacks, and a firefighter rescue. Participants included two unskilled samples (N = 14 and 22) and 143 firefighters. Firefighter performance was not significantly different from the unskilled subjects. Participants from both genders passed the test, with scores unrelated to performance skill or age; however, familiarization significantly improved performance when the test was repeated. These outcomes confirmed this test to be gender-, age-, and skill-neutral. Familiarization effects could be removed through performing a single, pre-selection trial of the test battery.

Are multiple visual short-term memory storages necessary to explain the retro-cue effect?

PubMed

Makovski, Tal

2012-06-01

Recent research has shown that change detection performance is enhanced when, during the retention interval, attention is cued to the location of the upcoming test item. This retro-cue advantage has led some researchers to suggest that visual short-term memory (VSTM) is divided into a durable, limited-capacity storage and a more fragile, high-capacity storage. Consequently, performance is poor on the no-cue trials because fragile VSTM is overwritten by the test display and only durable VSTM is accessible under these conditions. In contrast, performance is improved in the retro-cue condition because attention keeps fragile VSTM accessible. The aim of the present study was to test the assumptions underlying this two-storage account. Participants were asked to encode an array of colors for a change detection task involving no-cue and retro-cue trials. A retro-cue advantage was found even when the cue was presented after a visual (Experiment 1) or a central (Experiment 2) interference. Furthermore, the magnitude of the interference was comparable between the no-cue and retro-cue trials. These data undermine the main empirical support for the two-storage account and suggest that the presence of a retro-cue benefit cannot be used to differentiate between different VSTM storages.

Inter-Rater Reliability and Intra-Rater Reliability of Assessing the 2-Minute Push-Up Test.

PubMed

Fielitz, Lynn; Coelho, Jeffrey; Horne, Thomas; Brechue, William

2016-02-01

The purpose of this study was to assess inter-rater reliability and intra-rater reliability of the 2-minute, 90° push-up test as utilized in the Army Physical Fitness Test. Analysis of rater assessment reliability included both total score agreement and agreement across individual push-up repetitions. This study utilized 8 Raters who assessed 15 different videotaped push-up performances over 4 iterations separated by a minimum of 1 week. The 15 push-up participants were videotaped during the semiannual Army Physical Fitness Test. Each Rater randomly viewed the 15 push-up and verbally responded with a "yes" or "no" to each push-up repetition. The data generated were analyzed using the Pearson product-moment correlation as well as the kappa, modified kappa and the intra-class correlation coefficient (3,1). An attribute agreement analysis was conducted to determine the percent of inter-rater and intra-rater agreement across individual push-ups.The results indicated that Raters varied a great deal in assessing push-ups. Over the 4 trials of 15 participants, the overall scores of the Raters varied between 3.0 and 35.7 push-ups. Post hoc comparisons found that there was significant increase in the grand mean of push-ups from trials 1-3 to trial 4 (p < 0.05). Also, there was a significant difference among raters over the 4 trials (p < 0.05). Pearson correlation coefficients for inter-rater and intra-rater reliability identified inter-rater reliability coefficients were between 0.10 and 0.97. Intra-rater coefficients were between 0.48 and 0.99. Intra-rater agreement for individual push-up repetitions ranged from 41.8% to 84.8%. The results indicated that the raters failed to assess the same push-up repetition with the same score (below 70% agreement) as well as failed to agree when viewed between raters (29%). Interestingly, as previously mentioned, scores on trial 4 increased significantly which might have been caused by rater drift or that the Raters did not maintain the push-up standard over the trials. It does appear that the final push-up scores received by each participant was a close approximation of actual performance (within 65%) but when assessing physical performance for retention in the Army, a more reliable test might be considered. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Balance Training With a Dynamometric Platform Following Total Knee Replacement: A Randomized Controlled Trial.

PubMed

Roig-Casasús, Sergio; María Blasco, José; López-Bueno, Laura; Blasco-Igual, María Clara

2017-03-01

Sensorimotor training has proven to be an efficient approach for recovering balance control following total knee replacement (TKR). The purpose of this trial was to evaluate the influence of specific balance-targeted training using a dynamometric platform on the overall state of balance in older adults undergoing TKR. This was a randomized controlled clinical trial conducted at a university hospital rehabilitation unit. Patients meeting the inclusion criteria were randomly assigned to a control group or an experimental group. Both groups participated in the same 4-week postoperative rehabilitation training protocol. Participants in the experimental group performed additional balance training with a dynamometric platform consisting of tests related to stability challenges, weight-shifting, and moving to the limits of stability. The primary outcome measure was the overall state of balance rated according to the Berg Balance Scale. Secondary outcomes in terms of balance were the Timed Up and Go Test, Functional Reach Test, and Romberg open and closed-eyes tests. Data processing included between-group analysis of covariance, minimal detectable change assessment for the primary outcome measure, and effect size estimation. Confidence intervals (CIs) were set at 95%. Forty-three participants meeting the inclusion criteria and having signed the informed consent were randomly assigned to 2 groups. Thirty-seven completed the training (86.1%). Significant between-group differences in balance performance were found as measured with the Berg Balance Scale (P = .03) and Functional Reach Test (P = .04) with a CI = 95%. Significant differences were not recorded for the Timed Up and Go Test or Romberg open and closed-eyes tests (P > .05). Furthermore, Cohen's effect size resulted in a value of d = 0.97, suggesting a high practical significance of the trial. According to the Berg Balance Scale and Functional Reach Test, participants with TKR who have followed a 4-week training program using a dynamometric platform improved balance performance to a higher extent than a control group training without such a device. The inclusion of this instrument in the functional training protocol may be beneficial for recovering balance following TKR.

Verbal Learning and Memory Functions in Adolescents with Reading Disabilities

ERIC Educational Resources Information Center

Oyler, James D.; Obrzut, John E.; Asbjornsen, Arve E.

2012-01-01

The authors of this current study compared the memory performance of adolescent students with specific reading disabilities (RD) with that of typical adolescent readers on a newly developed verbal learning test, the "Bergen-Tucson Verbal Learning Test" (BTVLT). This multiple trial test was designed to measure memory acquisition,…

Measuring Misinformation in Repeat Trial Pick 1 of 2 Tests.

ERIC Educational Resources Information Center

Henderson, Pamela W.; Buchanan, Bruce

1992-01-01

An extension is described to a product-testing model to account for misinformation among subjects that would lead them to perform incorrectly on "pick one of two" tests. The model is applied to a data set of 367 subjects picking 1 of 2 colas. Misinformation does exist. (SLD)

Quality control ranges for testing broth microdilution susceptibility of Flavobacterium columnare and F. psychrophilium to nine antimicrobials

USDA-ARS?s Scientific Manuscript database

A multi-laboratory broth microdilution method trial was performed to standardize the specialized test conditions required for fish pathogens Flavobacterium columnare and F. pyschrophilum. Nine laboratories tested the quality control (QC) strains Escherichia coli ATCC 25922 and Aeromonas salmonicid...

Reliability and Concurrent Validity of the Narrow Path Walking Test in Persons With Multiple Sclerosis.

PubMed

Rosenblum, Uri; Melzer, Itshak

2017-01-01

About 90% of people with multiple sclerosis (PwMS) have gait instability and 50% fall. Reliable and clinically feasible methods of gait instability assessment are needed. The study investigated the reliability and validity of the Narrow Path Walking Test (NPWT) under single-task (ST) and dual-task (DT) conditions for PwMS. Thirty PwMS performed the NPWT on 2 different occasions, a week apart. Number of Steps, Trial Time, Trial Velocity, Step Length, Number of Step Errors, Number of Cognitive Task Errors, and Number of Balance Losses were measured. Intraclass correlation coefficients (ICC2,1) were calculated from the average values of NPWT parameters. Absolute reliability was quantified from standard error of measurement (SEM) and smallest real difference (SRD). Concurrent validity of NPWT with Functional Reach Test, Four Square Step Test (FSST), 12-item Multiple Sclerosis Walking Scale (MSWS-12), and 2 Minute Walking Test (2MWT) was determined using partial correlations. Intraclass correlation coefficients (ICCs) for most NPWT parameters during ST and DT ranged from 0.46-0.94 and 0.55-0.95, respectively. The highest relative reliability was found for Number of Step Errors (ICC = 0.94 and 0.93, for ST and DT, respectively) and Trial Velocity (ICC = 0.83 and 0.86, for ST and DT, respectively). Absolute reliability was high for Number of Step Errors in ST (SEM % = 19.53%) and DT (SEM % = 18.14%) and low for Trial Velocity in ST (SEM % = 6.88%) and DT (SEM % = 7.29%). Significant correlations for Number of Step Errors and Trial Velocity were found with FSST, MSWS-12, and 2MWT. In persons with PwMS performing the NPWT, Number of Step Errors and Trial Velocity were highly reliable parameters. Based on correlations with other measures of gait instability, Number of Step Errors was the most valid parameter of dynamic balance under the conditions of our test.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A159).

A Randomized Controlled Trial of Team-Based Learning Versus Lectures with Break-Out Groups on Knowledge Retention.

PubMed

Thrall, Grace C; Coverdale, John H; Benjamin, Sophiya; Wiggins, Anna; Lane, Christianne Joy; Pato, Michele T

2016-10-01

This goal of this study was to evaluate the efficacy of team-based learning (TBL) on knowledge retention compared to traditional lectures with small break-out group discussion (teaching as usual (TAU)) using a randomized controlled trial. This randomized controlled trial was conducted during a daylong conference for psychiatric educators on attention-deficit hyperactivity disorder and the research literacy topic of efficacy versus effectiveness trials. Learners (n = 115) were randomized with concealed allocation to either TBL or TAU. Knowledge was measured prior to the intervention, immediately afterward, and 2 months later via multiple-choice tests. Participants were necessarily unblinded. Data enterers, data analysts, and investigators were blinded to group assignment in data analysis. Per-protocol analyses of test scores were performed using change in knowledge from baseline. The primary endpoint was test scores at 2 months. At baseline, there were no statistically significant differences between groups in pre-test knowledge. At immediate post-test, both TBL and TAU groups showed improved knowledge scores compared with their baseline scores. The TBL group performed better statistically on the immediate post-test than the TAU group (Cohen's d = 0.73; p < 0.001), although the differences in knowledge scores were not educationally meaningful, averaging just one additional test question correct (out of 15). On the 2-month remote post-test, there were no group differences in knowledge retention among the 42 % of participants who returned the 2-month test. Both TBL and TAU learners acquired new knowledge at the end of the intervention and retained knowledge over 2 months. At the end of the intervention day and after 2 months, knowledge test scores were not meaningfully different between TBL and TAU completers. In conclusion, this study failed to demonstrate the superiority of TBL over TAU on the primary outcome of knowledge retention at 2 months post-intervention.

Barriers and facilitators of HIV vaccine and prevention study participation among Young Black MSM and transwomen in New York City

PubMed Central

Koblin, Beryl; Vazquez, Tasha; Nandi, Vijay; Tieu, Hong-Van

2017-01-01

Background Black men who have sex with men (MSM), and Transwomen (TW) shoulder disproportionate burden of HIV. However, they are unrepresented in HIV vaccine trials. We investigated the perceptions of that factors associated with HIV vaccine trials participation among Black MSM and TW in New York. Methods Self-administered online questionnaires were administered to 18–29 years of NYC residents who identified as Black MSM and TW, assessing demographics, awareness and willingness to participate in HIV vaccine trials, barriers and facilitators associated with willingness, and sexual behaviors. Frequency summation was performed to determine barriers and facilitators, and logistic regression analysis was performed to determine factors association with expressed willingness. Results Black MSM and TW who reported engaging in risk behaviors had a 61% lower likelihood of participating in HIV vaccine trials when compared to those who did not report engaging in any risk behavior. Facilitators associated with trial participation were: cash compensation, confidentiality regarding participation, public transportation vouchers, gift cards, and food or grocery vouchers as potential facilitators for trial participation. Conversely, fear of side effects from the vaccine, concerns about testing positive on routine HIV testing due to an HIV vaccine, limited knowledge of research trials, and fear of being judged as HIV-positive were perceived as barriers. Conclusions These findings provided insights into the considerations and perceptions of Black MSM and TW towards HIV vaccine trials. However, further studies are needed to delineate the complex mechanisms underlying the decision-making process and establish approaches to increase study participation in this population. PMID:28723970

The influence of trial order on learning from reward vs. punishment in a probabilistic categorization task: experimental and computational analyses

PubMed Central

Moustafa, Ahmed A.; Gluck, Mark A.; Herzallah, Mohammad M.; Myers, Catherine E.

2015-01-01

Previous research has shown that trial ordering affects cognitive performance, but this has not been tested using category-learning tasks that differentiate learning from reward and punishment. Here, we tested two groups of healthy young adults using a probabilistic category learning task of reward and punishment in which there are two types of trials (reward, punishment) and three possible outcomes: (1) positive feedback for correct responses in reward trials; (2) negative feedback for incorrect responses in punishment trials; and (3) no feedback for incorrect answers in reward trials and correct answers in punishment trials. Hence, trials without feedback are ambiguous, and may represent either successful avoidance of punishment or failure to obtain reward. In Experiment 1, the first group of subjects received an intermixed task in which reward and punishment trials were presented in the same block, as a standard baseline task. In Experiment 2, a second group completed the separated task, in which reward and punishment trials were presented in separate blocks. Additionally, in order to understand the mechanisms underlying performance in the experimental conditions, we fit individual data using a Q-learning model. Results from Experiment 1 show that subjects who completed the intermixed task paradoxically valued the no-feedback outcome as a reinforcer when it occurred on reinforcement-based trials, and as a punisher when it occurred on punishment-based trials. This is supported by patterns of empirical responding, where subjects showed more win-stay behavior following an explicit reward than following an omission of punishment, and more lose-shift behavior following an explicit punisher than following an omission of reward. In Experiment 2, results showed similar performance whether subjects received reward-based or punishment-based trials first. However, when the Q-learning model was applied to these data, there were differences between subjects in the reward-first and punishment-first conditions on the relative weighting of neutral feedback. Specifically, early training on reward-based trials led to omission of reward being treated as similar to punishment, but prior training on punishment-based trials led to omission of reward being treated more neutrally. This suggests that early training on one type of trials, specifically reward-based trials, can create a bias in how neutral feedback is processed, relative to those receiving early punishment-based training or training that mixes positive and negative outcomes. PMID:26257616

The effect of carbohydrate mouth rinse on performance, biochemical and psychophysiological variables during a cycling time trial: a crossover randomized trial.

PubMed

Ferreira, Amanda M J; Farias-Junior, Luiz F; Mota, Thaynan A A; Elsangedy, Hassan M; Marcadenti, Aline; Lemos, Telma M A M; Okano, Alexandre H; Fayh, Ana P T

2018-01-01

The hypothesis of the central effect of carbohydrate mouth rinse (CMR) on performance improvement in a fed state has not been established, and its psychophysiological responses have not yet been described. The aim of this study was to evaluate the effect of CMR in athletes fed state on performance, biochemical and psychophysiological responses compared to ad libitum water intake. Eleven trained male cyclists completed a randomized, crossover trial, which consisted of a 30 km cycle ergometer at self-selected intensity and in a fed state. Subjects were under random influence of the following interventions: CMR with a 6% unflavored maltodextrin solution; mouth rinsing with a placebo solution (PMR); drinking "ad libitum" (DAL). The time for completion of the test (min), heart rate (bpm) and power (watts), rating of perceived exertion (RPE), affective response, blood glucose (mg/dL) and lactate (mmol/DL), were evaluated before, during and immediately after the test, while insulin (uIL/mL), cortisol (μg/dL) and creatine kinase (U/L) levels were measured before, immediately after the test and 30 min after the test. Time for completion of the 30 km trial did not differ significantly among CMR, PMR and DAL interventions (means = 54.5 ± 2.9, 54.7 ± 2.9 and 54.5 ± 2.5 min, respectively; p  = 0.82). RPE and affective response were higher in DAL intervention ( p  < 0.01). Glucose, insulin, cortisol and creatine kinase responses showed no significant difference among interventions. In a fed state, CMR has not caused metabolic changes, and it has not improved physical performance compared to ad libitum water intake, but demonstrated a possible central effect. ReBec registration number: RBR-4vpwkg. Available in http://www.ensaiosclinicos.gov.br/rg/?q=RBR-4vpwkg.

Face distinctiveness and delayed testing: differential effects on performance and confidence.

PubMed

Metzger, Mitchell M

2006-04-01

The author investigated the effect of delayed testing on participants' memory for distinctive and typical faces. Participants viewed distinctive and typical faces and were then tested for recognition immediately or after a delay of 3, 6, or 12 weeks. Consistent with prior research, analysis of measure of sensitivity (d') showed that participants performed better on distinctive rather than typical faces, and memory performance declined with longer retention intervals between study and testing. Furthermore, the superior performance on distinctive faces had vanished by the 12-week test. Contrary to d' data, however, an analysis of confidence scores indicated that participants were still significantly more confident on trials depicting distinctive faces, even with a 12-week delay between study and recognition testing.

Examination of Cognitive Function During Six Months of Calorie Restriction: Results of a Randomized Controlled Trial

PubMed Central

Martin, Corby K.; Anton, Stephen D.; Han, Hongmei; York-Crowe, Emily; Redman, Leanne M.; Ravussin, Eric; Williamson, Donald A.

2009-01-01

Background Calorie restriction increases longevity in many organisms, and calorie restriction or its mimetic might increase longevity in humans. It is unclear if calorie restriction/dieting contributes to cognitive impairment. During this randomized controlled trial, the effect of 6 months of calorie restriction on cognitive functioning was tested. Methods Participants (n = 48) were randomized to one of four groups: (1) control (weight maintenance), (2) calorie restriction (CR; 25% restriction), (3) CR plus structured exercise (CR + EX, 12.5% restriction plus 12.5% increased energy expenditure via exercise), or (4) low-calorie diet (LCD; 890 kcal/d diet until 15% weight loss, followed by weight maintenance). Cognitive tests (verbal memory, visual memory, attention/concentration) were conducted at baseline and months 3 and 6. Mixed linear models tested if cognitive function changed significantly from baseline to months 3 and 6, and if this change differed by group. Correlation analysis was used to determine if average daily energy deficit (quantified from change in body energy stores) was associated with change in cognitive test performance for the three dieting groups combined. Results No consistent pattern of verbal memory, visual retention/memory, or attention/concentration deficits emerged during the trial. Daily energy deficit was not significantly associated with change in cognitive test performance. Conclusions This randomized controlled trial suggests that calorie restriction/dieting was not associated with a consistent pattern of cognitive impairment. These conclusions must be interpreted in the context of study limitations, namely small sample size and limited statistical power. Previous reports of cognitive impairment might reflect sampling biases or information processing biases. PMID:17518698

Individual Differences in the Severely Retarded Child in Acquisition, Stimulus Generalization, and Extinction in Go-No-Go Discrimination Learning

ERIC Educational Resources Information Center

Evans, P. L. C.; Hogg, J. H.

1975-01-01

This study relates excitatory and inhibitory personality variables of a heterogeneous group of severely retarded children to performance on a discrete trial, successive go-no-go intradimensional discrimination learning problem, which was followed by stimulus generalization tests on a color hue continuum and extinction trials. (GO)

Aided speech recognition in single-talker competition by elderly hearing-impaired listeners

NASA Astrophysics Data System (ADS)

Coughlin, Maureen; Humes, Larry

2004-05-01

This study examined the speech-identification performance in one-talker interference conditions that increased in complexity while audibility was ensured over a wide bandwidth (200-4000 Hz). Factorial combinations of three independent variables were used to vary the amount of informational masking. These variables were: (1) competition playback direction (forward or reverse); (2) gender match between target and competition talkers (same or different); and (3) target talker uncertainty (one of three possible talkers from trial to trial). Four groups of listeners, two elderly hearing-impaired groups differing in age (65-74 and 75-84 years) and two young normal-hearing groups, were tested. One of the groups of young normal-hearing listeners was tested under acoustically equivalent test conditions and one was tested under perceptually equivalent test conditions. The effect of each independent variable on speech-identification performance and informational masking was generally consistent with expectations. Group differences in the observed informational masking were most pronounced for the oldest group of hearing-impaired listeners. The eight measures of speech-identification performance were found to be strongly correlated with one another, and individual differences in speech understanding performance among the elderly were found to be associated with age and level of education. [Work supported, in part, by NIA.

The effects of amphetamine sensitization on conditioned inhibition during a Pavlovian-instrumental transfer task in rats

PubMed Central

Shiflett, Michael W.; Riccie, Meaghan; DiMatteo, RoseMarie

2013-01-01

Rationale Psychostimulant sensitization heightens behavioral and motivational responses to reward-associated stimuli; however, its effects on stimuli associated with reward absence are less understood. Objectives We examined whether amphetamine sensitization alters performance during Pavlovian-instrumental transfer (PIT) to conditioned excitors and inhibitors. We further sought to characterize the effects of amphetamine sensitization on learning versus performance by exposing rats to amphetamine prior to Pavlovian training or between training and test. Methods Adult male Long Evans rats were given conditioned inhibition (A+/AX−) and Pavlovian (B+) training, followed by variable-interval instrumental conditioning. Rats were sensitized to d-amphetamine (2 mg/kg daily injections for seven days), or served as non-exposed controls. Rats were given a PIT test, in which they were presented with stimulus B alone or in compound with the conditioned inhibitor (BX). Results During the PIT test, control rats significantly reduced instrumental responding on BX trials (to approximately 50% of responding to B). Amphetamine sensitization prior to Pavlovian conditioning increased lever-pressing on BX trials and reduced lever-pressing on B trials compared to controls. Amphetamine sensitization between training and test increased lever-pressing on B and BX trials compared to controls. No effects of sensitization were observed on conditioned food-cup approach. Conclusions Amphetamine sensitization increases instrumental responding during PIT to a conditioned inhibitor, by enhancing excitation of conditioned stimuli and reducing inhibition of conditioned inhibitors. PMID:23715640

Diurnal effects of prior heat stress exposure on sprint and endurance exercise capacity in the heat.

PubMed

Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Goto, Heita; Goto, Takayuki; Shirato, Minayuki

2018-03-21

Active individuals often perform exercises in the heat following heat stress exposure (HSE) regardless of the time-of-day and its variation in body temperature. However, there is no information concerning the diurnal effects of a rise in body temperature after HSE on subsequent exercise performance in a hot environnment. This study therefore investigated the diurnal effects of prior HSE on both sprint and endurance exercise capacity in the heat. Eight male volunteers completed four trials which included sprint and endurance cycling tests at 30 °C and 50% relative humidity. At first, volunteers completed a 30-min pre-exercise routine (30-PR): a seated rest in a temperate environment in AM (AmR) or PM (PmR) (Rest trials); and a warm water immersion at 40 °C to induce a 1 °C increase in core temperature in AM (AmW) or PM (PmW) (HSE trials). Volunteers subsequently commenced exercise at 0800 h in AmR/AmW and at 1700 h in PmR/PmW. The sprint test determined a 10-sec maximal sprint power at 5 kp. Then, the endurance test was conducted to measure time to exhaustion at 60% peak oxygen uptake. Maximal sprint power was similar between trials (p = 0.787). Time to exhaustion in AmW (mean±SD; 15 ± 8 min) was less than AmR (38 ± 16 min; p < 0.01) and PmR (43 ± 24 min; p < 0.01) but similar with PmW (24 ± 9 min). Core temperature was higher from post 30-PR to 6 min into the endurance test in AmW and PmW than AmR and PmR (p < 0.05) and at post 30-PR and the start of the endurance test in PmR than AmR (p < 0.05). The rate of rise in core temperature during the endurance test was greater in AmR than AmW and PmW (p < 0.05). Mean skin temperature was higher from post 30-PR to 6 min into the endurance test in HSE trials than Rest trials (p < 0.05). Mean body temperature was higher from post 30-PR to 6 min into the endurance test in AmW and PmW than AmR and PmR (p < 0.05) and the start to 6 min into the endurance test in PmR than AmR (p < 0.05). Convective, radiant, dry and evaporative heat losses were greater on HSE trials than on Rest trials (p < 0.001). Heart rate and cutaneous vascular conductance were higher at post 30-PR in HSE trials than Rest trials (p < 0.05). Thermal sensation was higher from post 30-PR to the start of the endurance test in AmW and PmW than AmR and PmR (p < 0.05). Perceived exertion from the start to 6 min into the endurance test was higher in HSE trials than Rest trials (p < 0.05). This study demonstrates that an approximately 1 °C increase in core temperature by prior HSE has the diurnal effects on endurance exercise capacity but not on sprint exercise capacity in the heat. Moreover, prior HSE reduces endurance exercise capacity in AM, but not in PM. This reduction is associated with a large difference in pre-exercise core temperature between AM trials which is caused by a relatively lower body temperature in the morning due to the time-of-day variation and contributes to lengthening the attainment of high core temperature during exercise in AmR.

Machine on Trial

DTIC Science & Technology

2012-06-01

executed a concerted effort to employ reliability standards and testing from the design phase through fielding. Reliability programs remain standard...performed flight test engineer duties on several developmental flight test programs and served as Chief Engineer for a flight test squadron. Major...Quant is an acquisition professional with over 250 flight test hours in various aircraft, including the F-16, Airborne Laser, and HH-60. She holds a

Ensemble codes involving hippocampal neurons are at risk during delayed performance tests.

PubMed

Hampson, R E; Deadwyler, S A

1996-11-26

Multielectrode recording techniques were used to record ensemble activity from 10 to 16 simultaneously active CA1 and CA3 neurons in the rat hippocampus during performance of a spatial delayed-nonmatch-to-sample task. Extracted sources of variance were used to assess the nature of two different types of errors that accounted for 30% of total trials. The two types of errors included ensemble "miscodes" of sample phase information and errors associated with delay-dependent corruption or disappearance of sample information at the time of the nonmatch response. Statistical assessment of trial sequences and associated "strength" of hippocampal ensemble codes revealed that miscoded error trials always followed delay-dependent error trials in which encoding was "weak," indicating that the two types of errors were "linked." It was determined that the occurrence of weakly encoded, delay-dependent error trials initiated an ensemble encoding "strategy" that increased the chances of being correct on the next trial and avoided the occurrence of further delay-dependent errors. Unexpectedly, the strategy involved "strongly" encoding response position information from the prior (delay-dependent) error trial and carrying it forward to the sample phase of the next trial. This produced a miscode type error on trials in which the "carried over" information obliterated encoding of the sample phase response on the next trial. Application of this strategy, irrespective of outcome, was sufficient to reorient the animal to the proper between trial sequence of response contingencies (nonmatch-to-sample) and boost performance to 73% correct on subsequent trials. The capacity for ensemble analyses of strength of information encoding combined with statistical assessment of trial sequences therefore provided unique insight into the "dynamic" nature of the role hippocampus plays in delay type memory tasks.

A Virtual Water Maze Revisited: Two-Year Changes in Navigation Performance and their Neural Correlates in Healthy Adults

PubMed Central

Daugherty, Ana M.; Raz, Naftali

2016-01-01

Age-related declines in spatial navigation are associated with deficits in procedural and episodic memory and deterioration of their neural substrates. For the lack of longitudinal evidence, the pace and magnitude of these declines and their neural mediators remain unclear. Here we examined virtual navigation in healthy adults (N=213, age 18–77 years) tested twice, two years apart, with complementary indices of navigation performance (path length and complexity) measured over six learning trials at each occasion. Slopes of skill acquisition curves and longitudinal change therein were estimated in structural equation modeling, together with change in regional brain volumes and iron content (R2* relaxometry). Although performance on the first trial did not differ between occasions separated by two years, the slope of path length improvement over trials was shallower and end-of-session performance worse at follow-up. Advanced age, higher pulse pressure, smaller cerebellar and caudate volumes, and greater caudate iron content were associated with longer search paths, i.e. poorer navigation performance. In contrast, path complexity diminished faster over trials at follow-up, albeit less so in older adults. Improvement in path complexity after two years was predicted by lower baseline hippocampal iron content and larger parahippocampal volume. Thus, navigation path length behaves as an index of perceptual-motor skill that is vulnerable to age-related decline, whereas path complexity may reflect cognitive mapping in episodic memory that improves with repeated testing, although not enough to overcome age-related deficits. PMID:27659539

A virtual water maze revisited: Two-year changes in navigation performance and their neural correlates in healthy adults.

PubMed

Daugherty, Ana M; Raz, Naftali

2017-02-01

Age-related declines in spatial navigation are associated with deficits in procedural and episodic memory and deterioration of their neural substrates. For the lack of longitudinal evidence, the pace and magnitude of these declines and their neural mediators remain unclear. Here we examined virtual navigation in healthy adults (N=213, age 18-77 years) tested twice, two years apart, with complementary indices of navigation performance (path length and complexity) measured over six learning trials at each occasion. Slopes of skill acquisition curves and longitudinal change therein were estimated in structural equation modeling, together with change in regional brain volumes and iron content (R2* relaxometry). Although performance on the first trial did not differ between occasions separated by two years, the slope of path length improvement over trials was shallower and end-of-session performance worse at follow-up. Advanced age, higher pulse pressure, smaller cerebellar and caudate volumes, and greater caudate iron content were associated with longer search paths, i.e. poorer navigation performance. In contrast, path complexity diminished faster over trials at follow-up, albeit less so in older adults. Improvement in path complexity after two years was predicted by lower baseline hippocampal iron content and larger parahippocampal volume. Thus, navigation path length behaves as an index of perceptual-motor skill that is vulnerable to age-related decline, whereas path complexity may reflect cognitive mapping in episodic memory that improves with repeated testing, although not enough to overcome age-related deficits. Copyright © 2016 Elsevier Inc. All rights reserved.

A quality assessment of randomized controlled trial reports in endodontics.

PubMed

Lucena, C; Souza, E M; Voinea, G C; Pulgar, R; Valderrama, M J; De-Deus, G

2017-03-01

To assess the quality of the randomized clinical trial (RCT) reports published in Endodontics between 1997 and 2012. Retrieval of RCTs in Endodontics was based on a search of the Thomson Reuters Web of Science (WoS) database (March 2013). Quality evaluation was performed using a checklist based on the Jadad criteria, CONSORT (Consolidated Standards of Reporting Trials) statement and SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials). Descriptive statistics were used for frequency distribution of data. Student's t-test and Welch test were used to identify the influence of certain trial characteristics upon report quality (α = 0.05). A total of 89 RCTs were evaluated, and several methodological flaws were found: only 45% had random sequence generation at low risk of bias, 75% did not provide information on allocation concealment, and 19% were nonblinded designs. Regarding statistics, only 55% of the RCTs performed adequate sample size estimations, only 16% presented confidence intervals, and 25% did not provide the exact P-value. Also, 2% of the articles used no statistical tests, and in 87% of the RCTs, the information provided was insufficient to determine whether the statistical methodology applied was appropriate or not. Significantly higher scores were observed for multicentre trials (P = 0.023), RCTs signed by more than 5 authors (P = 0.03), articles belonging to journals ranked above the JCR median (P = 0.03), and articles complying with the CONSORT guidelines (P = 0.000). The quality of RCT reports in key areas for internal validity of the study was poor. Several measures, such as compliance with the CONSORT guidelines, are important in order to raise the quality of RCTs in Endodontics. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Five-Kilometers Time Trial: Preliminary Validation of a Short Test for Cycling Performance Evaluation.

PubMed

Dantas, Jose Luiz; Pereira, Gleber; Nakamura, Fabio Yuzo

2015-09-01

The five-kilometer time trial (TT5km) has been used to assess aerobic endurance performance without further investigation of its validity. This study aimed to perform a preliminary validation of the TT5km to rank well-trained cyclists based on aerobic endurance fitness and assess changes of the aerobic endurance performance. After the incremental test, 20 cyclists (age = 31.3 ± 7.9 years; body mass index = 22.7 ± 1.5 kg/m(2); maximal aerobic power = 360.5 ± 49.5 W) performed the TT5km twice, collecting performance (time to complete, absolute and relative power output, average speed) and physiological responses (heart rate and electromyography activity). The validation criteria were pacing strategy, absolute and relative reliability, validity, and sensitivity. Sensitivity index was obtained from the ratio between the smallest worthwhile change and typical error. The TT5km showed high absolute (coefficient of variation < 3%) and relative (intraclass coefficient correlation > 0.95) reliability of performance variables, whereas it presented low reliability of physiological responses. The TT5km performance variables were highly correlated with the aerobic endurance indices obtained from incremental test (r > 0.70). These variables showed adequate sensitivity index (> 1). TT5km is a valid test to rank the aerobic endurance fitness of well-trained cyclists and to differentiate changes on aerobic endurance performance. Coaches can detect performance changes through either absolute (± 17.7 W) or relative power output (± 0.3 W.kg(-1)), the time to complete the test (± 13.4 s) and the average speed (± 1.0 km.h(-1)). Furthermore, TT5km performance can also be used to rank the athletes according to their aerobic endurance fitness.

Robustness of statistical tests for multiplicative terms in the additive main effects and multiplicative interaction model for cultivar trials.

PubMed

Piepho, H P

1995-03-01

The additive main effects multiplicative interaction model is frequently used in the analysis of multilocation trials. In the analysis of such data it is of interest to decide how many of the multiplicative interaction terms are significant. Several tests for this task are available, all of which assume that errors are normally distributed with a common variance. This paper investigates the robustness of several tests (Gollob, F GH1, FGH2, FR)to departures from these assumptions. It is concluded that, because of its better robustness, the F Rtest is preferable. If the other tests are to be used, preliminary tests for the validity of assumptions should be performed.

PERFORMANCE OF A COMPUTER-BASED ASSESSMENT OF COGNITIVE FUNCTION MEASURES IN TWO COHORTS OF SENIORS

PubMed Central

Espeland, Mark A.; Katula, Jeffrey A.; Rushing, Julia; Kramer, Arthur F.; Jennings, Janine M.; Sink, Kaycee M.; Nadkarni, Neelesh K.; Reid, Kieran F.; Castro, Cynthia M.; Church, Timothy; Kerwin, Diana R.; Williamson, Jeff D.; Marottoli, Richard A.; Rushing, Scott; Marsiske, Michael; Rapp, Stephen R.

2013-01-01

Background Computer-administered assessment of cognitive function is being increasingly incorporated in clinical trials, however its performance in these settings has not been systematically evaluated. Design The Seniors Health and Activity Research Program (SHARP) pilot trial (N=73) developed a computer-based tool for assessing memory performance and executive functioning. The Lifestyle Interventions and Independence for Seniors (LIFE) investigators incorporated this battery in a full scale multicenter clinical trial (N=1635). We describe relationships that test scores have with those from interviewer-administered cognitive function tests and risk factors for cognitive deficits and describe performance measures (completeness, intra-class correlations). Results Computer-based assessments of cognitive function had consistent relationships across the pilot and full scale trial cohorts with interviewer-administered assessments of cognitive function, age, and a measure of physical function. In the LIFE cohort, their external validity was further demonstrated by associations with other risk factors for cognitive dysfunction: education, hypertension, diabetes, and physical function. Acceptable levels of data completeness (>83%) were achieved on all computer-based measures, however rates of missing data were higher among older participants (odds ratio=1.06 for each additional year; p<0.001) and those who reported no current computer use (odds ratio=2.71; p<0.001). Intra-class correlations among clinics were at least as low (ICC≤0.013) as for interviewer measures (ICC≤0.023), reflecting good standardization. All cognitive measures loaded onto the first principal component (global cognitive function), which accounted for 40% of the overall variance. Conclusion Our results support the use of computer-based tools for assessing cognitive function in multicenter clinical trials of older individuals. PMID:23589390

Effect of low-level laser therapy (LLLT) and light-emitting diodes (LEDT) applied during combined training on performance and post-exercise recovery: protocol for a randomized placebo-controlled trial.

PubMed

Machado, Aryane Flauzino; Micheletti, Jéssica Kirsch; Vanderlei, Franciele Marques; Nakamura, Fabio Yuzo; Leal-Junior, Ernesto Cesar Pinto; Netto Junior, Jayme; Pastre, Carlos Marcelo

Previous studies have shown positive results of phototherapy for improving performance and accelerating recovery; however, the effects of phototherapy during training and after a primary adaptation remain unclear. The aim of this randomized controlled trial is to analyze the effects of phototherapy and combined training on clinical, functional, and psychological outcomes and on vascular endothelial growth factor. This randomized placebo-controlled trial by stratified sample will involve 45 healthy male participants. In phase 1, the participants will undergo six weeks of combined training (sprints and squats). In phase 2, participants will be allocated through stratified randomization (based on adaptation capacity) into three groups: active phototherapy group (AG), placebo group (PG), and non-treatment control group (CG). A new six-week training program will then start and the participants will receive the recovery strategy between sprints and squats. The primary outcome will be maximal isometric contraction. The secondary outcomes include strength and power testing, maximal incremental test, squat jump, sprint test, muscle soreness, pain threshold, perceptions of exertion and recovery, psychological questionnaire, and vascular endothelial growth factor. This will be the first trial to include phototherapy during training. We believe that this strategy will combine the ergogenic and prophylactic effects in the same session. Furthermore, an application protocol performed after primary adaptation may reflect the real effect of the technique. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

First external quality assurance program for bloodstream Real-Time PCR monitoring of treatment response in clinical trials of Chagas disease.

PubMed

Ramírez, Juan C; Parrado, Rudy; Sulleiro, Elena; de la Barra, Anabelle; Rodríguez, Marcelo; Villarroel, Sandro; Irazu, Lucía; Alonso-Vega, Cristina; Alves, Fabiana; Curto, María A; García, Lineth; Ortiz, Lourdes; Torrico, Faustino; Gascón, Joaquim; Flevaud, Laurence; Molina, Israel; Ribeiro, Isabela; Schijman, Alejandro G

2017-01-01

Real-Time PCR (qPCR) testing is recommended as both a diagnostic and outcome measurement of etiological treatment in clinical practice and clinical trials of Chagas disease (CD), but no external quality assurance (EQA) program provides performance assessment of the assays in use. We implemented an EQA system to evaluate the performance of molecular biology laboratories involved in qPCR based follow-up in clinical trials of CD. An EQA program was devised for three clinical trials of CD: the E1224 (NCT01489228), a pro-drug of ravuconazole; the Sampling Study (NCT01678599), that used benznidazole, both conducted in Bolivia; and the CHAGASAZOL (NCT01162967), that tested posaconazole, conducted in Spain. Four proficiency testing panels containing negative controls and seronegative blood samples spiked with 1, 10 and 100 parasite equivalents (par. eq.)/mL of four Trypanosoma cruzi stocks, were sent from the Core Lab in Argentina to the participating laboratories located in Bolivia and Spain. Panels were analyzed simultaneously, blinded to sample allocation, at 4-month intervals. In addition, 302 random blood samples from both trials carried out in Bolivia were sent to Core Lab for retesting analysis. The analysis of proficiency testing panels gave 100% of accordance (within laboratory agreement) and concordance (between laboratory agreement) for all T. cruzi stocks at 100 par. eq./mL; whereas their values ranged from 71 to 100% and from 62 to 100% at 1 and 10 par. eq./mL, respectively, depending on the T. cruzi stock. The results obtained after twelve months of preparation confirmed the stability of blood samples in guanidine-EDTA buffer. No significant differences were found between qPCR results from Bolivian laboratory and Core Lab for retested clinical samples. This EQA program for qPCR analysis of CD patient samples may significantly contribute to ensuring the quality of laboratory data generated in clinical trials and molecular diagnostics laboratories of CD.

Effectiveness of the Epley’s maneuver performed in primary care to treat posterior canal benign paroxysmal positional vertigo: study protocol for a randomized controlled trial

PubMed Central

2014-01-01

Background Vertigo is a common medical condition with a broad spectrum of diagnoses which requires an integrated approach to patients through a structured clinical interview and physical examination. The main cause of vertigo in primary care is benign paroxysmal positional vertigo (BPPV), which should be confirmed by a positive D-H positional test and treated with repositioning maneuvers. The objective of this study is to evaluate the effectiveness of Epley’s maneuver performed by general practitioners (GPs) in the treatment of BPPV. Methods/Design This study is a randomized clinical trial conducted in the primary care setting. The study’s scope will include two urban primary care centers which provide care for approximately 49,400 patients. All patients attending these two primary care centers, who are newly diagnosed with benign paroxysmal positional vertigo, will be invited to participate in the study and will be randomly assigned either to the treatment group (Epley’s maneuver) or to the control group (a sham maneuver). Both groups will receive betahistine. Outcome variables will be: response to the D-H test, patients’ report on presence or absence of vertigo during the previous week (dichotomous variable: yes/no), intensity of vertigo symptoms on a Likert-type scale in the previous week, total score on the Dizziness Handicap Inventory (DHI) and quantity of betahistine taken. We will use descriptive statistics of all variables collected. Groups will be compared using the intent-to-treat approach and either parametric or nonparametric tests, depending on the nature and distribution of the variables. Chi-square test or Fisher’s exact test will be conducted to compare categorical measures and Student’s t-test or Mann–Whitney U-test will be used for intergroup comparison variables. Discussion Positive results from our study will highlight that treatment of benign paroxysmal positional vertigo can be performed by trained general practitioners (GPs) and, therefore, its widespread practice may contribute to improve the quality of life of BPPV patients. Trial registration ClinicalTrials.gov Identifier: NCT01969513. PMID:24886338

Nitrate supplementation improves physical performance specifically in non-athletes during prolonged open-ended tests: a systematic review and meta-analysis.

PubMed

Campos, Helton O; Drummond, Lucas R; Rodrigues, Quezia T; Machado, Frederico S M; Pires, Washington; Wanner, Samuel P; Coimbra, Cândido C

2018-03-01

Nitrate (NO3 -) is an ergogenic nutritional supplement that is widely used to improve physical performance. However, the effectiveness of NO3 - supplementation has not been systematically investigated in individuals with different physical fitness levels. The present study analysed whether different fitness levels (non-athletes v. athletes or classification of performance levels), duration of the test used to measure performance (short v. long duration) and the test protocol (time trials v. open-ended tests v. graded-exercise tests) influence the effects of NO3 - supplementation on performance. This systematic review and meta-analysis was conducted and reported according to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. A systematic search of electronic databases, including PubMed, Web of Science, SPORTDiscus and ProQuest, was performed in August 2017. On the basis of the search and inclusion criteria, fifty-four and fifty-three placebo-controlled studies evaluating the effects of NO3 - supplementation on performance in humans were included in the systematic review and meta-analysis, respectively. NO3 - supplementation was ergogenic in non-athletes (mean effect size (ES) 0·25; 95 % CI 0·11, 0·38), particularly in evaluations of performance using long-duration open-ended tests (ES 0·47; 95 % CI 0·23, 0·71). In contrast, NO3 - supplementation did not enhance the performance of athletes (ES 0·04; 95 % CI -0·05, 0·15). After objectively classifying the participants into different performance levels, the frequency of trials showing ergogenic effects in individuals classified at lower levels was higher than that in individuals classified at higher levels. Thus, the present study indicates that dietary NO3 - supplementation improves physical performance in non-athletes, particularly during long-duration open-ended tests.

Familiarisation and Reliability of Sprint Test Indices During Laboratory and Field Assessment

PubMed Central

Hopker, James G.; Coleman, Damian A.; Wiles, Jonathan D.; Galbraith, Andrew

2009-01-01

The aim of the study was to assess the reliability of sprint performance in both field and laboratory conditions. Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg) and seventeen female team sport players (mean ± s: 21 ± 4 years, 1.68 ± 0. 07 m, 62.7 ± 4.7 kg) performed a maximal 20-metre sprint running test on eight separate occasions. Four trials were conducted on a non-motorised treadmill in the laboratory; the other four were conducted outdoors on a hard-court training surface with time recorded by single-beam photocells. Trials were conducted in random order with no familiarisation prior to testing. There was a significant difference between times recorded during outdoor field trials (OFT) and indoor laboratory trials (ILT) using a non-motorised treadmill (3.47 ± 0.53 vs. 6.06 ±1.17s; p < 0.001). The coefficient of variation (CV) for time was 2.55-4.22% for OFT and 5.1-7.2% for ILT. During ILT peak force (420.9 ± 87.7N), mean force (147.2 ± 24.7N), peak power (1376.8 ± 451.9W) and mean power (514.8 ± 164.4W), and were measured. The CV for all ILT variables was highest during trial 1-2 comparison. The CV (95% confidence interval) for the trial 3-4 comparison yielded: 9.4% (7.7-12. 1%), 7.9% (6.4-10.2%), 10.1% (8.2-13.1%) and 6.2% (5.1-8.0%) for PF, MF, PP and MP and respectively. The results indicate that reliable data can be derived for single maximal sprint measures, using fixed distance protocols. However, significant differences in time/speed over 20-m exist between field and laboratory conditions. This is primarily due to the frictional resistance in the non- motorised treadmill. Measures of force and power during ILT require at least 3 familiarisations to reduce variability in test scores. Key points Reliable data can be derived from single maximal sprint measures in both indoor and outdoor environments using fixed distance protocols. There may be significant time differences to complete fixed distance trials between the two environments. Measures of mean force, peak force and peak power during indoor trials may require multiple trials to reduce variability in test scores. PMID:24149593

A systematic review to evaluate the effectiveness of carnitine supplementation in improving walking performance among individuals with intermittent claudication.

PubMed

Delaney, Christopher L; Spark, J Ian; Thomas, Jolene; Wong, Yew Toh; Chan, Lok Tsung; Miller, Michelle D

2013-07-01

To evaluate the evidence for the use of carnitine supplementation in improving walking performance among individuals with intermittent claudication. Systematic review. An electronic search of the literature was performed using MEDLINE (PubMed), Scopus, Cochrane Central Register of Controlled Trials and The Cochrane Library from inception through to November 2012. Search terms included peripheral arterial disease, intermittent claudication and carnitine. Reference lists of review articles and primary studies were also examined. Full reports of published experimental studies including randomized controlled trials and pre-test/post-test trials were selected for inclusion. A quality assessment was undertaken according to the Jadad scale. A total of 40 articles were retrieved, of which 23 did not meet the inclusion criteria. The 17 included articles reported on a total of 18 experimental studies of carnitine supplementation (5 pre-test/post-test; 8 parallel RCT; 5 cross-over RCT) for improving walking performance in adults with intermittent claudication. For pre-test/post-test studies, 300-2000 mg propionyl-L-carnitine (PLC) was administered orally or intravenously for a maximum of 90 days (7-42 participants) with statistically significant improvements of between 74 m and 157 m in pain free walking distance and between 71 m and 135 m in maximal walking distance across 3 out of 5 studies. Similarly, PLC (600 mg-3000 mg) was administered orally in 7 out of 8 parallel RCTs (22-485 participants), the longest duration being 12 months. All but one of the smallest trials demonstrated statistically significant improvements in walking performance between 31 and 54 m greater than placebo for pain free walking distance and between 9 and 86 m greater than placebo for maximal walking distance. A double-blind parallel RCT of cilostazol plus 2000 mg oral L-carnitine or placebo for 180 days (145 participants) did not demonstrate any significant improvement in walking performance. Of 5 cross-over RCTs (8-20 participants), 4 demonstrated significant improvements in walking performance following administration of 300-6000 mg L-carnitine or PLC. Compared to placebo, pain free walking distance and maximal walking distance improved by 23-132 m and 104 m respectively following carnitine intervention. Most trials demonstrated a small or modest improvement in walking performance with administration of PLC or L-carnitine. These findings were largely independent of level or quality of evidence, while there was some evidence that intravenous administration was more effective than oral administration and those with severe claudication may achieve greater benefits than those with moderate claudication. Routine carnitine supplementation in the form of PLC may therefore be a useful adjunct therapy for management of intermittent claudication. Further research is warranted to determine the optimal form, duration, dose and safety of carnitine supplementation across the spectrum of peripheral arterial disease severity and its effect with concurrent supervised exercise programs and best medical therapy. These studies should be supplemented with cost effectiveness studies to ensure that the return on the investment is acceptable. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

Reproducibility of a silicone-based test food to masticatory performance evaluation by different sieve methods.

PubMed

Sánchez-Ayala, Alfonso; Vilanova, Larissa Soares Reis; Costa, Marina Abrantes; Farias-Neto, Arcelino

2014-01-01

The aim of this study was to evaluate the reproducibility of the condensation silicone Optosil Comfort® as an artificial test food for masticatory performance evaluation. Twenty dentate subjects with mean age of 23.3±0.7 years were selected. Masticatory performance was evaluated using the simple (MPI), the double (IME) and the multiple sieve methods. Trials were carried out five times by three examiners: three times by the first, and once by the second and third examiners. Friedman's test was used to find the differences among time trials. Reproducibility was determined by the intra-class correlation (ICC) test (α=0.05). No differences among time trials were found, except for MPI-4 mm (p=0.022) from the first examiner results. The intra-examiner reproducibility (ICC) of almost all data was high (ICC≥0.92, p<0.001), being moderate only for MPI-0.50 mm (ICC=0.89, p<0.001). The inter-examiner reproducibility was high (ICC>0.93, p<0.001) for all results. For the multiple sieve method, the average mean of absolute difference from repeated measurements were lower than 1 mm. This trend was observed only from MPI-0.50 to MPI-1.4 for the single sieve method, and from IME-0.71/0.50 to IME-1.40/1.00 for the double sieve method. The results suggest that regardless of the method used, the reproducibility of Optosil Comfort® is high.

Enhanced aerobic exercise performance in women by a combination of three mineral Chelates plus two conditionally essential nutrients.

PubMed

DiSilvestro, Robert A; Hart, Staci; Marshall, Trisha; Joseph, Elizabeth; Reau, Alyssa; Swain, Carmen B; Diehl, Jason

2017-01-01

Certain essential and conditionally essential nutrients (CENs) perform functions involved in aerobic exercise performance. However, increased intake of such nutrient combinations has not actually been shown to improve such performance. For 1 mo, aerobically fit, young adult women took either a combination of 3 mineral glycinate complexes (daily dose: 36 mg iron, 15 mg zinc, and 2 mg copper) + 2 CENs (daily dose: 2 g carnitine and 400 mg phosphatidylserine), or the same combination with generic mineral complexes, or placebo ( n  = 14/group). In Trial 1, before and after 1 mo, subjects were tested for 3 mile run time (primary outcome), followed by distance covered in 25 min on a stationary bike (secondary outcome), followed by a 90 s step test (secondary outcome). To test reproducibility of the run results, and to examine a lower dose of carnitine, a second trial was done. New subjects took either mineral glycinates + CENs (1 g carnitine) or placebo ( n  = 17/group); subjects were tested for pre- and post-treatment 3 mile run time (primary outcome). In Trial 1, the mineral glycinates + CENs decreased 3 mile run time (25.6 ± 2.4 vs 26.5 ± 2.3 min, p  < 0.05, paired t-test) increased stationary bike distance after 25 min (6.5 ± 0.6 vs 6.0 ± 0.8 miles, p  < 0.05, paired t-test), and increased steps in the step test (43.8 ± 4.8 vs 40.3 ± 6.4 steps, p < 0.05, paired t-test). The placebo significantly affected only the biking distance, but it was less than for the glycinates-CENs treatment (0.2 ± 0.4. vs 0.5 ± 0.1 miles, p < 0.05, ANOVA + Tukey). The generic minerals + CENs only significantly affected the step test (44.1 ± 5.2 vs 41.0 ± 5.9 steps, p < 0.05, paired t-test) In Trial 2, 3 mile run time was decreased for the mineral glycinates + CENs (23.9 ± 3.1 vs 24.7 ± 2.5, p  < 0.005, paired t-test), but not by the placebo. All changes for Test Formula II or III were high compared to placebo (1.9 to 4.9, Cohen's D), and high for Test Formula II vs I for running and biking (3.2 & 3.5, Cohen's D). In summary, a combination of certain mineral complexes plus two CENs improved aerobic exercise performance in fit young adult women.

Influence of artificial sweetener on human blood glucose concentration.

PubMed

Skokan, Ilse; Endler, P Christian; Wulkersdorfer, Beatrix; Magometschnigg, Dieter; Spranger, Heinz

2007-10-05

Artificial sweeteners, such as saccharin or cyclamic acid are synthetically manufactured sweetenings. Known for their low energetic value they serve especially diabetic and adipose patients as sugar substitutes. It has been hypothesized that the substitution of sugar with artificial sweeteners may induce a decrease of the blood glucose. The aim of this study was to determine the reliability of this hypothesis by comparing the influence of regular table sugar and artificial sweeteners on the blood glucose concentration. In this pilot-study 16 patients were included suffering from adiposity, pre-diabetes and hypertension. In the sense of a cross-over design, three test trials were performed at intervals of several weeks. Each trial was followed by a test free interval. Within one test trial each patient consumed 150 ml test solution (water) that contained either 6 g of table sugar ("Kandisin") with sweetener free serving as control group. Tests were performed within 1 hr after lunch to ensure conditions comparable to patients having a desert. Every participant had to determine their blood glucose concentration immediately before and 5, 15, 30 and 60 minutes after the intake of the test solution. For statistics an analysis of variance was performed. The data showed no significant changes in the blood glucose concentration. Neither the application of sugar (F(4;60) = 1.645; p = .175) nor the consumption of an artificial sweetener (F(2.068;31.023) = 1.551; p > .05) caused significant fluctuations in the blood sugar levels. Over a time frame of 60 minutes in the control group a significant decrease of the blood sugar concentration was found (F(2.457;36.849) = 4.005; p = .020) as a physiological reaction during lunch digestion.

Gut-training: the impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance.

PubMed

Costa, Ricardo J S; Miall, Atlanta; Khoo, Anthony; Rauch, Christopher; Snipe, Rhiannon; Camões-Costa, Vera; Gibson, Peter

2017-05-01

Due to gastrointestinal tract adaptability, the study aimed to determine the impact of gut-training protocol over 2 weeks on gastrointestinal status, blood glucose availability, fuel kinetics, and running performance. Endurance runners (n = 25) performed a gut-challenge trial (GC1), consisting of 2 h running exercise at 60% V̇O 2max whilst consuming gel-discs containing 30 g carbohydrates (2:1 glucose/fructose, 10% w/v) every 20 min and a 1 h distance test. Participants were then randomly assigned to a carbohydrate gel-disc (CHO-S), carbohydrate food (CHO-F), or placebo (PLA) gut-training group for 2 weeks of repetitive gut-challenge intervention. Participants then repeated a second gut-challenge trial (GC2). Gastrointestinal symptoms reduced in GC2 on CHO-S (60%; p = 0.008) and CHO-F (63%; p = 0.046); reductions were greater than PLA (p < 0.05). H 2 peak was lower in GC2 on CHO-S (mean (CI): 6 (4-8) ppm) compared with CHO-F (9 (6-12) ppm) and PLA (12 (2-21) ppm) (trial × time: p < 0.001). Blood glucose concentration was higher in GC2 on CHO-S (7.2 (6.3-8.1) mmol·L -1 ) compared with CHO-F (6.1 (5.7-6.5) mmol·L -1 ) and PLA (6.2 (4.9-7.5) mmol·L -1 ) (trial × time: p = 0.015). No difference in oxidation rates, plasma I-FABP, and cortisol concentrations were observed between groups and trials. Distance test improved on CHO-S (5.2%) and CHO-F (4.3%) in GC2, but not on PLA (-2.1%) (trial × time: p = 0.009). Two weeks of gut-training with CHO-S and CHO-F improved gastrointestinal symptoms and running performance compared with PLA. CHO-S also reduced malabsorption and increased blood glucose availability during endurance running compared with PLA.

Initial test results from a prototype, 20 kW helium charged Stirling engine

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

Clarke, M.A.; Taylor, D.R.

An alpha-configuration, helium charged Stirling engine with a predicted output of 20 kW indicated power has been developed by a British consortium of universities and industrial companies. The work performed by the Royal Naval Engineering College has been in computer assisted design and component testing, with future plans for full engine trials during 1984/85. The scope of this paper is to outline the data obtained during motoring trials of the engine block and crankcase assembly, together with details of modifications incorporated in the various components.

Executive function processes predict mobility outcomes in older adults.

PubMed

Gothe, Neha P; Fanning, Jason; Awick, Elizabeth; Chung, David; Wójcicki, Thomas R; Olson, Erin A; Mullen, Sean P; Voss, Michelle; Erickson, Kirk I; Kramer, Arthur F; McAuley, Edward

2014-02-01

To examine the relationship between performance on executive function measures and subsequent mobility outcomes in community-dwelling older adults. Randomized controlled clinical trial. Champaign-Urbana, Illinois. Community-dwelling older adults (N = 179; mean age 66.4). A 12-month exercise trial with two arms: an aerobic exercise group and a stretching and strengthening group. Established cognitive tests of executive function (flanker task, task switching, and a dual-task paradigm) and the Wisconsin card sort test. Mobility was assessed using the timed 8-foot up and go test and times to climb up and down a flight of stairs. Participants completed the cognitive tests at baseline and the mobility measures at baseline and after 12 months of the intervention. Multiple regression analyses were conducted to determine whether baseline executive function predicted postintervention functional performance after controlling for age, sex, education, cardiorespiratory fitness, and baseline mobility levels. Selective baseline executive function measurements, particularly performance on the flanker task (β = 0.15-0.17) and the Wisconsin card sort test (β = 0.11-0.16) consistently predicted mobility outcomes at 12 months. The estimates were in the expected direction, such that better baseline performance on the executive function measures predicted better performance on the timed mobility tests independent of intervention. Executive functions of inhibitory control, mental set shifting, and attentional flexibility were predictive of functional mobility. Given the literature associating mobility limitations with disability, morbidity, and mortality, these results are important for understanding the antecedents to poor mobility function that well-designed interventions to improve cognitive performance can attenuate. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Performance determinants of fixed gear cycling during criteriums.

PubMed

Babault, Nicolas; Poisson, Maxime; Cimadoro, Guiseppe; Cometti, Carole; Païzis, Christos

2018-06-17

Nowadays, fixed gear competitions on outdoor circuits such as criteriums are regularly organized worldwide. To date, no study has investigated this alternative form of cycling. The purpose of the present study was to examine fixed gear performance indexes and to characterize physiological determinants of fixed gear cyclists. This study was carried out in two parts. Part 1 (n = 36) examined correlations between performance indexes obtained during a real fixed gear criterium (time trial, fastest laps, averaged lap time during races, fatigue indexes) and during a sprint track time trial. Part 2 (n = 9) examined correlations between the recorded performance indexes and some aerobic and anaerobic performance outputs (VO 2max , maximal aerobic power, knee extensor and knee flexor maximal voluntary torque, vertical jump height and performance during a modified Wingate test). Results from Part 1 indicated significant correlations between fixed gear final performance (i.e. average lap time during the finals) and single lap time (time trial, fastest lap during races and sprint track time trial). In addition, results from Part 2 revealed significant correlations between fixed gear performance and aerobic indicators (VO 2max and maximal aerobic power). However, no significant relationship was obtained between fixed gear cycling and anaerobic qualities such as strength. Similarly to traditional cycling disciplines, we concluded that fixed gear cycling is mainly limited by aerobic capacity, particularly criteriums final performance. However, specific skills including technical competency should be considered.

Learning Mathematics in a Visuospatial Format: A Randomized, Controlled Trial of Mental Abacus Instruction

ERIC Educational Resources Information Center

Barner, David; Alvarez, George; Sullivan, Jessica; Brooks, Neon; Srinivasan, Mahesh; Frank, Michael C.

2016-01-01

Mental abacus (MA) is a technique of performing fast, accurate arithmetic using a mental image of an abacus; experts exhibit astonishing calculation abilities. Over 3 years, 204 elementary school students (age range at outset: 5-7 years old) participated in a randomized, controlled trial to test whether MA expertise (a) can be acquired in standard…

20 CFR 220.17 - Recovery from disability for work in the regular occupation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... period. The trial work period is a period during which the annuitant may test his or her ability to work... ability to perform those duties. (d) Limitations on the number of trial work periods. The annuitant may... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Recovery from disability for work in the...

20 CFR 220.17 - Recovery from disability for work in the regular occupation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... period. The trial work period is a period during which the annuitant may test his or her ability to work... ability to perform those duties. (d) Limitations on the number of trial work periods. The annuitant may... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Recovery from disability for work in the...

20 CFR 220.17 - Recovery from disability for work in the regular occupation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... period. The trial work period is a period during which the annuitant may test his or her ability to work... ability to perform those duties. (d) Limitations on the number of trial work periods. The annuitant may... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Recovery from disability for work in the...

20 CFR 220.17 - Recovery from disability for work in the regular occupation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... period. The trial work period is a period during which the annuitant may test his or her ability to work... ability to perform those duties. (d) Limitations on the number of trial work periods. The annuitant may... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Recovery from disability for work in the...

Event-related potential correlates of emergent inference in human arbitrary relational learning.

PubMed

Wang, Ting; Dymond, Simon

2013-01-01

Two experiments investigated the functional-anatomical correlates of cognition supporting untrained, emergent relational inference in a stimulus equivalence task. In Experiment 1, after learning a series of conditional relations involving words and pseudowords, participants performed a relatedness task during which EEG was recorded. Behavioural performance was faster and more accurate on untrained, indirectly related symmetry (i.e., learn AB and infer BA) and equivalence trials (i.e., learn AB and AC and infer CB) than on unrelated trials, regardless of whether or not a formal test for stimulus equivalence relations had been conducted. Consistent with previous results, event related potentials (ERPs) evoked by trained and emergent trials at parietal and occipital sites differed only for those participants who had not received a prior equivalence test. Experiment 2 further replicated and extended these behavioural and ERP findings using arbitrary symbols as stimuli and demonstrated time and frequency differences for trained and untrained relatedness trials. Overall, the findings demonstrate convincingly the ERP correlates of intra-experimentally established stimulus equivalence relations consisting entirely of arbitrary symbols and offer support for a contemporary cognitive-behavioural model of symbolic categorisation and relational inference. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of modafinil on attention performance, short-term memory and executive function in university students: a randomized trial.

PubMed

Fernández, Alejandro; Mascayano, Franco; Lips, Walter; Painel, Andrés; Norambuena, Jonathan; Madrid, Eva

2015-06-30

Modafinil is a drug developed and used for the treatment of excessive lethargy. Even though very effective for sleep disorders, it is still controversial whether modafinil can improve performance in high-order cognitive processes such as memory and executive function. This randomized, double-blind, placebo-controlled, crossover trial was designed to evaluate the effect of modafinil (compared to placebo) on the cognitive functions of healthy students. 160 volunteers were recruited and allocated randomly to modafinil or placebo group, and were assessed using the Stroop Test, BCET test and Digit span test. We found a significant difference in favor of modafinil compared to placebo in the proportion of correct answers of Stroop Test in congruent situation. A significant shorter latency of modafinil group in the incongruent situation of Stroop test was also found. No differences were found in Digit Span, or BCET tests. The study demonstrated that modafinil does not enhance the global cognitive performance of healthy non-sleep deprived students, except regarding non-demanding tasks. In particular, this drug does not seem to have positive effects on mental processes that sustain studying tasks in the college population under normal conditions. We expect these findings to demystify the use of this drug and help decision making concerning pharmacological public policies.

Development of Methods for Cross-Sectional HIV Incidence Estimation in a Large, Community Randomized Trial

PubMed Central

Donnell, Deborah; Komárek, Arnošt; Omelka, Marek; Mullis, Caroline E.; Szekeres, Greg; Piwowar-Manning, Estelle; Fiamma, Agnes; Gray, Ronald H.; Lutalo, Tom; Morrison, Charles S.; Salata, Robert A.; Chipato, Tsungai; Celum, Connie; Kahle, Erin M.; Taha, Taha E.; Kumwenda, Newton I.; Karim, Quarraisha Abdool; Naranbhai, Vivek; Lingappa, Jairam R.; Sweat, Michael D.; Coates, Thomas; Eshleman, Susan H.

2013-01-01

Background Accurate methods of HIV incidence determination are critically needed to monitor the epidemic and determine the population level impact of prevention trials. One such trial, Project Accept, a Phase III, community-randomized trial, evaluated the impact of enhanced, community-based voluntary counseling and testing on population-level HIV incidence. The primary endpoint of the trial was based on a single, cross-sectional, post-intervention HIV incidence assessment. Methods and Findings Test performance of HIV incidence determination was evaluated for 403 multi-assay algorithms [MAAs] that included the BED capture immunoassay [BED-CEIA] alone, an avidity assay alone, and combinations of these assays at different cutoff values with and without CD4 and viral load testing on samples from seven African cohorts (5,325 samples from 3,436 individuals with known duration of HIV infection [1 month to >10 years]). The mean window period (average time individuals appear positive for a given algorithm) and performance in estimating an incidence estimate (in terms of bias and variance) of these MAAs were evaluated in three simulated epidemic scenarios (stable, emerging and waning). The power of different test methods to detect a 35% reduction in incidence in the matched communities of Project Accept was also assessed. A MAA was identified that included BED-CEIA, the avidity assay, CD4 cell count, and viral load that had a window period of 259 days, accurately estimated HIV incidence in all three epidemic settings and provided sufficient power to detect an intervention effect in Project Accept. Conclusions In a Southern African setting, HIV incidence estimates and intervention effects can be accurately estimated from cross-sectional surveys using a MAA. The improved accuracy in cross-sectional incidence testing that a MAA provides is a powerful tool for HIV surveillance and program evaluation. PMID:24236054

Cathodal transcranial direct current stimulation in children with dystonia: a pilot open-label trial.

PubMed

Young, Scott J; Bertucco, Matteo; Sheehan-Stross, Rebecca; Sanger, Terence D

2013-10-01

Studies suggest that dystonia is associated with increased motor cortex excitability. Cathodal transcranial direct current stimulation can temporarily reduce motor cortex excitability. To test whether stimulation of the motor cortex can reduce dystonic symptoms in children, we measured tracking performance and muscle overflow using an electromyogram tracking task before and after stimulation. Of 10 participants, 3 showed a significant reduction in overflow, and a fourth showed a significant reduction in tracking error. Overflow decreased more when the hand contralateral to the cathode performed the task than when the hand ipsilateral to the cathode performed the task. Averaged over all participants, the results did not reach statistical significance. These results suggest that cathodal stimulation may allow a subset of children to control muscles or reduce involuntary overflow activity. Further testing is needed to confirm these results in a blinded trial and identify the subset of children who are likely to respond.

Effects of Water Provision and Hydration on Cognitive Function among Primary-School Pupils in Zambia: A Randomized Trial

PubMed Central

Trinies, Victoria; Chard, Anna N.; Mateo, Tommy; Freeman, Matthew C.

2016-01-01

There is a well-established link between hydration and improved cognitive performance among adults, with evidence of similar findings among children. No trials have investigated the impact of water provision on cognitive performance among schoolchildren in hot and arid low-resource settings. We conducted a randomized-controlled trial in five schools with limited water access in Chipata district in Eastern province, Zambia, to assess the efficacy of water provision on cognition. Pupils in grades 3–6 were randomly assigned to either receive a bottle of drinking water that they could refill throughout the day (water group, n = 149) or only have access to drinking water that was normally available at the school (control group, n = 143). Hydration was assessed in the morning before provision of water and in the afternoon through urine specific gravity (Usg) measured with a portable refractometer. In the afternoon we administered six cognitive tests to assess short-term memory, concentration, visual attention, and visual motor skills. Morning prevalence of dehydration, defined as Usg≥1.020, was 42%. Afternoon dehydration increased to 67% among the control arm and dropped to 10% among the intervention arm. We did not find that provision of water or hydration impacted cognitive test scores, although there were suggestive relationships between both water provision and hydration and increased scores on tests measuring visual attention. We identified key improvements to the study design that are warranted to further investigate this relationship. Trial Registration: ClinicalTrials.gov NCT01924546 PMID:26950696

Exploring anterograde memory: a volumetric MRI study in patients with mild cognitive impairment.

PubMed

Philippi, N; Noblet, V; Duron, E; Cretin, B; Boully, C; Wisniewski, I; Seux, M L; Martin-Hunyadi, C; Chaussade, E; Demuynck, C; Kremer, S; Lehéricy, S; Gounot, D; Armspach, J P; Hanon, O; Blanc, F

2016-07-30

The aim of this volumetric study was to explore the neuroanatomical correlates of the Free and Cued Selective Reminding Test (FCSRT) and the Delayed Matching-to-Sample-48 items (DMS-48), two tests widely used in France to assess verbal and visual anterograde memory. We wanted to determine to what extent the two tests rely on the medial temporal lobe, and could therefore be predictive of Alzheimer's disease, in which pathological changes typically start in this region. We analysed data from a cohort of 138 patients with mild cognitive impairment participating in a longitudinal multicentre clinical research study. Verbal memory was assessed using the FCSRT and visual recognition memory was evaluated using the DMS-48. Performances on these two tests were correlated to local grey matter atrophy via structural MRI using voxel-based morphometry. Our results confirm the existence of a positive correlation between the volume of the medial temporal lobe and the performance on the FCSRT, prominently on the left, and the performance on the DMS-48, on the right, for the whole group of patients (family-wise error, P < 0.05). Interestingly, this region remained implicated only in the subgroup of patients who had deficient scores on the cued recall of the FCSRT, whereas the free recall was associated with prefrontal aspects. For the DMS-48, it was only implicated for the group of patients whose performances declined between the immediate and delayed trial. Conversely, temporo-parietal cortices were implicated when no decline was observed. Within the medial temporal lobe, the parahippocampal gyrus was prominently involved for the FCSRT and the immediate trial of the DMS-48, whereas the hippocampus was solely involved for the delayed trial of the DMS-48. The two tests are able to detect an amnestic profile of the medial temporal type, under the condition that the scores remain deficient after the cued recall of the FCSRT or decline on the delayed recognition trial of the DMS-48. Strategic retrieval as well as perceptual/attentional processes, supported by prefrontal and temporo-parietal cortices, were also found to have an impact on the performances. Finally, the implication of the hippocampus appears time dependent, triggered by a longer delay than the parahippocampus, rather than determined by the sense of recollection or the encoding strength associated with the memory trace.

Attempted establishment of proficiency levels for laparoscopic performance on a national scale using simulation: the results from the 2004 SAGES Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) learning center study.

PubMed

Van Sickle, K R; Ritter, E M; McClusky, D A; Lederman, A; Baghai, M; Gallagher, A G; Smith, C D

2007-01-01

The Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) has been well validated as a training device for laparoscopic skills. It has been demonstrated that training to a level of proficiency on the simulator significantly improves operating room performance of laparoscopic cholecystectomy. The purpose of this project was to obtain a national standard of proficiency using the MIST-VR based on the performance of experienced laparoscopic surgeons. Surgeons attending the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) 2004 Annual Scientific Meeting who had performed more than 100 laparoscopic procedures volunteered to participate. All the subjects completed a demographic questionnaire assessing laparoscopic and MIST-VR experience in the learning center of the SAGES 2004 meeting. Each subject performed two consecutive trials of the MIST-VR Core Skills 1 program at the medium setting. Each trial involved six basic tasks of increasing difficulty: acquire place (AP), transfer place (TP), traversal (TV), withdrawal insert (WI), diathermy task (DT), and manipulate diathermy (MD). Trial 1 was considered a "warm-up," and trial 2 functioned as the test trial proper. Subject performance was scored for time, errors, and economy of instrument movement for each task, and a cumulative total score was calculated. Trial 2 data are expressed as mean time in seconds in Table 2. Proficiency levels for laparoscopic skills have now been established on a national scale by experienced laparoscopic surgeons using the MIST-VR simulator. Residency programs, training centers, and practicing surgeons can now use these data as guidelines for performance criterion during MIST-VR skills training.

Training unsupported sitting in people with chronic spinal cord injuries: a randomized controlled trial.

PubMed

Boswell-Ruys, C L; Harvey, L A; Barker, J J; Ben, M; Middleton, J W; Lord, S R

2010-02-01

Randomized, assessor-blinded trial. To evaluate the effectiveness of a 6-week task-specific training programme on the abilities of people with chronic spinal cord injuries to sit unsupported. NSW, Australia. Thirty adults with spinal cord injuries of at least 1-year duration were recruited. Participants in the training group (n=15) performed up to 1 h of task-specific training three times a week for 6 weeks. Participants in the control group (n=15) did not receive any training or additional therapy. Primary outcome measures were the Canadian Occupational Performance Measure (COPM), and tests of Upper Body Sway, Maximal Balance Range and donning and doffing a T-shirt (the T-shirt test). The between-group mean difference (95% confidence interval) for the maximal balance range was 64 mm (95% confidence interval 20 to 108 mm; P=0.006). There were no significant between-group mean differences for the COPM and the Upper Body Sway and T-shirt tests. This trial shows initial support for intensive task-specific training for improving the abilities of people with chronic spinal cord injuries to sit unsupported, although the real-world implications of the observed treatment effects are yet to be determined.

Lower skin temperature decreases maximal cycling performance.

PubMed

Imai, Daiki; Okazaki, Kazunobu; Matsumura, Shinya; Suzuki, Takashi; Miyazawa, Taiki; Suzuki, Akina; Takeda, Ryosuke; Hamamoto, Takeshi; Zako, Tetsuo; Kawabata, Takashi; Miyagawa, Toshiaki

2011-12-01

It is known that external cooling of body regions involved in exercise, prior to exercise, decreases anaerobic performance. However, there have been no studies reporting the effects of whole body skin surface cooling before exercise on maximal anaerobic capacity. In order to clarify the effects, we compared power output during the Wingate anaerobic test between preconditioning by exposure to temperature 10 degrees C and 25 degrees C. Eight healthy males carried out the Wingate test for 30 seconds, after pre-conditioning for 60 minutes using a perfusion suit with water at a temperature of 10 degrees C or 25 degrees C. We evaluated the peak power (PP) and peak power slope (PS) of the power output. Mean skin temperature (T(sk)) at 60 minutes of pre-conditioning in the 10 degrees C trial was significantly lower than in the 25 degrees C trial (p < 0.05). PP and also PS were significantly lower in the 10 degrees C trial than in the 25 degrees C trial. Changes (Δ) in PP between the 10 degrees C trial and the 25 degrees C trial were strongly correlated with ΔT(sk) and Δ in thigh and leg skin temperature (ΔT(thigh) and ΔT(leg), respectively), whereas ΔPS was strongly correlated with ΔT(sk), but not with ΔT(thigh) and ΔT(leg). Whole body skin surface cooling prior to exercise restricts anaerobic capacity, especially in the initial phase of exercise.

Detection of new HIV infections in a multicentre HIV antiretroviral pre-exposure prophylaxis trial.

PubMed

Fransen, Katrien; de Baetselier, Irith; Rammutla, Elizabeth; Ahmed, Khatija; Owino, Frederick; Agingu, Walter; Venter, Gustav; Deese, Jen; Van Damme, Lut; Crucitti, Tania

2017-08-01

Monthly specimens collected from FEM-PrEP-a Phase III trial [1] were investigated for the detection of acute HIV (AHI) infection. To evaluate the efficiency of the study-specific HIV algorithm in detecting AHI, and the performance of each of the serological and molecular tests used in diagnosing new infections, and their contribution to narrowing the window period. A total of 83 pre-seroconversion specimens from 61 seroconverters from the FEM-PrEP trial were further analyzed in a sub-study. During the trial, HIV seroconversion was diagnosed on site using a testing algorithm with simple/rapid tests (SRTs) and confirmed with a gold standard testing algorithm (see short communication: Fig. 1). The infection date was determined more accurately by the use of standard ELISAs and Nucleic Acid Amplification Tests (NAAT) in a look-back procedure. For this sub-study, the international central laboratory repeated the study algorithm using SRTs. A total of 83 pre-seroconversions specimens from 61 seroconverters were analyzed in a look-back procedure. RNA was detected in 35/61 seroconverters at the visit before the seroconversion visit as determined at the study sites. Four seroconversion dates were inaccurate at one study site as the international central laboratory detected the HIV infection one visit earlier using the same test algorithm. Using the gold standard, an additional seroconversion was detected at an earlier visit. The combined antigen/antibody and the single antigen test had a higher sensitivity compared to the SRTs in detecting acute infections. In the FEM-PrEP trial, the international central laboratory detected a small number of seroconversions one month earlier than the study sites using the same study algorithm. Standard tests are still the most sensitive tests in detecting pre-seroconversion or acute HIV infection, but they are costly, time consuming and not recommended for use on-site in a clinical trial. Copyright © 2017 Elsevier B.V. All rights reserved.

Physiological and behavioral parameters of infants' categorization: changes in heart rate and duration of examining across trials.

PubMed

Elsner, Birgit; Pauen, Sabina; Jeschonek, Susanna

2006-11-01

This report investigates the relations between duration of examining and heart rate (HR) across several trials of an object-examination task. A total of N= 20 11-month-olds were familiarized with a sequence of 10 different exemplars from the same global category (animals or furniture) before they received an exemplar from the contrasting category at test. Consistent with previous findings, HR was lower during states of focused attention (i.e. examining) than during states of casual attention (i.e. looking) or non-looking. Over the familiarization trials, examining stayed about the same, while mean HR increased. At test, examining increased and mean HR decreased, indicating that infants focused their attention on the out-of-category object. Psychophysiological and behavioral measures of attention were systematically related over trials, suggesting that heart rate provides a suitable objective measure to study infants' categorization performance in object-examination tasks.

Modafinil Improves Real Driving Performance in Patients with Hypersomnia: A Randomized Double-Blind Placebo-Controlled Crossover Clinical Trial

PubMed Central

Philip, Pierre; Chaufton, Cyril; Taillard, Jacques; Capelli, Aurore; Coste, Olivier; Léger, Damien; Moore, Nicholas; Sagaspe, Patricia

2014-01-01

Study Objective: Patients with excessive daytime sleepiness (EDS) are at high risk for driving accidents, and physicians are concerned by the effect of alerting drugs on driving skills of sleepy patients. No study has up to now investigated the effect of modafinil (a reference drug to treat EDS in patients with hypersomnia) on on-road driving performance of patients suffering from central hypersomnia. The objective is to evaluate in patients with central hypersomnia the effect of a wake-promoting drug on real driving performance and to assess the relationship between objective sleepiness and driving performance. Design and Participants: Randomized, crossover, double-blind placebo-controlled trial conducted among 13 patients with narcolepsy and 14 patients with idiopathic hypersomnia. Patients were randomly assigned to receive modafinil (400 mg) or placebo for 5 days prior to the driving test. Each condition was separated by at least 3 weeks of washout. Measurements: Mean number of Inappropriate Line Crossings, Standard Deviation of Lateral Position of the vehicle and mean sleep latency in the Maintenance of Wakefulness Test were assessed. Results: Modafinil reduced the mean number of Inappropriate Line Crossings and Standard Deviation of Lateral Position of the vehicle compared to placebo (F(1,25) = 4.88, P < 0.05 and F(1,25) = 3.87, P = 0.06 tendency). Mean sleep latency at the Maintenance of Wakefulness Test significantly correlated with the mean number of Inappropriate Line Crossings (r = -0.41, P < 0.001). Conclusions: Modafinil improves driving performance in patients with narcolepsy and idiopathic hypersomnia. The Maintenance of Wakefulness Test is a suitable clinical tool to assess fitness to drive in this population. Citation: Philip P; Chaufton C; Taillard J; Capelli A; Coste O; Léger D; Moore N; Sagaspe P. Modafinil improves real driving performance in patients with hypersomnia: a randomized double-blind placebo-controlled crossover clinical trial. SLEEP 2014;37(3):483-487. PMID:24587570

A joint sparse representation-based method for double-trial evoked potentials estimation.

PubMed

Yu, Nannan; Liu, Haikuan; Wang, Xiaoyan; Lu, Hanbing

2013-12-01

In this paper, we present a novel approach to solving an evoked potentials estimating problem. Generally, the evoked potentials in two consecutive trials obtained by repeated identical stimuli of the nerves are extremely similar. In order to trace evoked potentials, we propose a joint sparse representation-based double-trial evoked potentials estimation method, taking full advantage of this similarity. The estimation process is performed in three stages: first, according to the similarity of evoked potentials and the randomness of a spontaneous electroencephalogram, the two consecutive observations of evoked potentials are considered as superpositions of the common component and the unique components; second, making use of their characteristics, the two sparse dictionaries are constructed; and finally, we apply the joint sparse representation method in order to extract the common component of double-trial observations, instead of the evoked potential in each trial. A series of experiments carried out on simulated and human test responses confirmed the superior performance of our method. © 2013 Elsevier Ltd. Published by Elsevier Ltd. All rights reserved.

Hypothesis tests for stratified mark-specific proportional hazards models with missing covariates, with application to HIV vaccine efficacy trials.

PubMed

Sun, Yanqing; Qi, Li; Yang, Guangren; Gilbert, Peter B

2018-05-01

This article develops hypothesis testing procedures for the stratified mark-specific proportional hazards model with missing covariates where the baseline functions may vary with strata. The mark-specific proportional hazards model has been studied to evaluate mark-specific relative risks where the mark is the genetic distance of an infecting HIV sequence to an HIV sequence represented inside the vaccine. This research is motivated by analyzing the RV144 phase 3 HIV vaccine efficacy trial, to understand associations of immune response biomarkers on the mark-specific hazard of HIV infection, where the biomarkers are sampled via a two-phase sampling nested case-control design. We test whether the mark-specific relative risks are unity and how they change with the mark. The developed procedures enable assessment of whether risk of HIV infection with HIV variants close or far from the vaccine sequence are modified by immune responses induced by the HIV vaccine; this question is interesting because vaccine protection occurs through immune responses directed at specific HIV sequences. The test statistics are constructed based on augmented inverse probability weighted complete-case estimators. The asymptotic properties and finite-sample performances of the testing procedures are investigated, demonstrating double-robustness and effectiveness of the predictive auxiliaries to recover efficiency. The finite-sample performance of the proposed tests are examined through a comprehensive simulation study. The methods are applied to the RV144 trial. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adverse effect of combination of chronic psychosocial stress and high fat diet on hippocampus-dependent memory in rats.

PubMed

Alzoubi, K H; Abdul-Razzak, K K; Khabour, O F; Al-Tuweiq, G M; Alzubi, M A; Alkadhi, K A

2009-12-01

The combined effects of high fat diet (HFD) and chronic stress on the hippocampus-dependent spatial learning and memory were studied in rats using the radial arm water maze (RAWM). Chronic psychosocial stress and/or HFD were simultaneously administered for 3 months to young adult male Wister rats. In the RAWM, rats were subjected to 12 learning trials as well as short-term and long-term memory tests. This procedure was applied on a daily basis until the animal reaches days to criterion (DTC) in the 12th learning trial and in memory tests. DTC is the number of days that the animal takes to make zero error in two consecutive days. Groups were compared based on the number of errors per trial or test as well as on the DTC. Chronic stress, HFD and chronic stress/HFD animal groups showed impaired learning as indicated by committing significantly (P<0.05) more errors than untreated control group in trials 6 through 9 of day 4. In memory tests, chronic stress, HFD and chronic stress/HFD groups showed significantly impaired performance compared to control group. Additionally, the stress/HFD was the only group that showed significantly impaired performance in memory tests on the 5th training day, suggesting more severe memory impairment in that group. Furthermore, DTC value for above groups indicated that chronic stress or HFD, alone, resulted in a mild impairment of spatial memory, but the combination of chronic stress and HFD resulted in a more severe and long-lasting memory impairment. The data indicated that the combination of stress and HFD produced more deleterious effects on hippocampal cognitive function than either chronic stress or HFD alone.

Relative frequency of knowledge of performance and motor skill learning.

PubMed

Weeks, D L; Kordus, R N

1998-09-01

This study examined the effects of variations in relative frequency of knowledge of performance (KP) on acquisition, retention, and transfer of form for a multilimb closed sport skill. Two groups received either 100% relative frequency of KP or 33% relative frequency of KP while learning the soccer throw-in skill. Participants were boys between the ages of 11 and 14 years who were unfamiliar with the skill. Participants performed a 30-trial acquisition phase in which KP was provided about one of eight aspects of form. Following acquisition, five trial retention and transfer (to a target at a different distance than experienced in acquisition) tests were administered at 5 min, 24 hr, and 72 hr. Although no group differences were found for accuracy scores, the 33% group had higher form scores in acquisition and all retention and transfer tests. It was concluded that reducing the relative frequency of KP eliminated a dependency on KP to guide performance in acquisition, which was beneficial for maintaining form in conditions in which KP was absent.

Effects of the neurological wake-up test on clinical examination, intracranial pressure, brain metabolism and brain tissue oxygenation in severely brain-injured patients

PubMed Central

2012-01-01

Introduction Daily interruption of sedation (IS) has been implemented in 30 to 40% of intensive care units worldwide and may improve outcome in medical intensive care patients. Little is known about the benefit of IS in acutely brain-injured patients. Methods This prospective observational study was performed in a neuroscience intensive care unit in a tertiary-care academic center. Twenty consecutive severely brain-injured patients with multimodal neuromonitoring were analyzed for levels of brain lactate, pyruvate and glucose, intracranial pressure (ICP), cerebral perfusion pressure (CPP) and brain tissue oxygen tension (PbtO2) during IS trials. Results Of the 82 trial days, 54 IS-trials were performed as interruption of sedation and analgesics were not considered safe on 28 days (34%). An increase in the FOUR Score (Full Outline of UnResponsiveness score) was observed in 50% of IS-trials by a median of three (two to four) points. Detection of a new neurologic deficit occurred in one trial (2%), and in one-third of IS-trials the trial had to be stopped due to an ICP-crisis (> 20 mmHg), agitation or systemic desaturation. In IS-trials that had to be aborted, a significant increase in ICP and decrease in PbtO2 (P < 0.05), including 67% with critical values of PbtO2 < 20 mmHg, a tendency to brain metabolic distress (P < 0.07) was observed. Conclusions Interruption of sedation revealed new relevant clinical information in only one trial and a large number of trials could not be performed or had to be stopped due to safety issues. Weighing pros and cons of IS-trials in patients with acute brain injury seems important as related side effects may overcome the clinical benefit. PMID:23186037

Internet-Based Cervical Cytology Screening Program

DTIC Science & Technology

2005-04-01

and Second Trials of Each Pathologist. * Reference diagnostic category: NEG, ASCUS , LSIL > HSIL Pathologist 1 Interpretation. Negative or LSIL 24 (22...Principal Investigator: David C. Wdlbbur, M.D. Description of Subject Population: Women above the age of l18 years having Pap tests performe PURPOSE We...Subject Population: Women above the age of 18 years having Pay tests performed IRB Protocol Number: 2003P-001658 Sponsor Protocol Number: n/a Consent Form

Taxonomy for colorectal cancer screening promotion: Lessons from recent randomized controlled trials.

PubMed

Ritvo, Paul; Myers, Ronald E; Serenity, Mardie; Gupta, Samir; Inadomi, John M; Green, Beverly B; Jerant, Anthony; Tinmouth, Jill; Paszat, Lawrence; Pirbaglou, Meysam; Rabeneck, Linda

2017-08-01

To derive a taxonomy for colorectal cancer screening that advances Randomized Controlled Trials (RCTs) and screening uptake. Detailed publication review, multiple interviews with principal investigators (PIs) and collaboration with PIs as co-authors produced a CRCS intervention taxonomy. Semi-structured interview questions with PIs (Drs. Inadomi, Myers, Green, Gupta, Jerant and Ritvo) yielded details about trial conduct. Interview comparisons led to an iterative process informing serial interviews until a consensus was obtained on final taxonomy structure. These taxonomy headings (Engagement Sponsor, Population Targeted, Alternative Screening Tests, Delivery Methods, and Support for Test Performance (EPADS)) were used to compare studies. Exemplary insights emphasized: 1) direct test delivery to patients; 2) linguistic-ethnic matching of staff to minority subjects; and 3) authorization of navigators to schedule or refer for colonoscopies and/or distribute stool blood tests during screening promotion. PIs of key RCTs (2012-2015) derived a CRCS taxonomy useful in detailed examination of CRCS promotion and design of future RCTs. Copyright © 2017 Elsevier Inc. All rights reserved.

Discriminating between camouflaged targets by their time of detection by a human-based observer assessment method

NASA Astrophysics Data System (ADS)

Selj, G. K.; Søderblom, M.

2015-10-01

Detection of a camouflaged object in natural sceneries requires the target to be distinguishable from its local background. The development of any new camouflage pattern therefore has to rely on a well-founded test methodology - which has to be correlated with the final purpose of the pattern - as well as an evaluation procedure, containing the optimal criteria for i) discriminating between the targets and then eventually ii) for a final rank of the targets. In this study we present results from a recent camouflage assessment trial where human observers were used in a search by photo methodology to assess generic test camouflage patterns. We conducted a study to investigate possible improvements in camouflage patterns for battle dress uniforms. The aim was to do a comparative study of potential, and generic patterns intended for use in arid areas (sparsely vegetated, semi desert). We developed a test methodology that was intended to be simple, reliable and realistic with respect to the operational benefit of camouflage. Therefore we chose to conduct a human based observer trial founded on imagery of realistic targets in natural backgrounds. Inspired by a recent and similar trial in the UK, we developed new and purpose-based software to be able to conduct the observer trial. Our preferred assessment methodology - the observer trial - was based on target recordings in 12 different, but operational relevant scenes, collected in a dry and sparsely vegetated area (Rhodes). The scenes were chosen with the intention to span as broadly as possible. The targets were human-shaped mannequins and were situated identically in each of the scenes to allow for a relative comparison of camouflage effectiveness in each scene. Test of significance, among the targets' performance, was carried out by non-parametric tests as the corresponding time of detection distributions in overall were found to be difficult to parameterize. From the trial, containing 12 different scenes from sparsely vegetated areas we collected detection time's distributions for 6 generic targets through visual search by 148 observers. We found that the different targets performed differently, given by their corresponding time of detection distributions, within a single scene. Furthermore, we gained an overall ranking over all the 12 scenes by performing a weighted sum over all scenes, intended to keep as much of the vital information on the targets' signature effectiveness as possible. Our results show that it was possible to measure the targets performance relatively to another also when summing over all scenes. We also compared our ranking based on our preferred criterion (detection time) with a secondary (probability of detection) to assess the sensitivity of a final ranking based upon the test set-up and evaluation criterion. We found our observer-based approach to be well suited regarding its ability to discriminate between similar targets and to assign numeric values to the observed differences in performance. We believe our approach will be well suited as a tool whenever different aspects of camouflage are to be evaluated and understood further.

Competition between items in working memory leads to forgetting.

PubMed

Lewis-Peacock, Jarrod A; Norman, Kenneth A

2014-12-18

Switching attention from one thought to the next propels our mental lives forward. However, it is unclear how this thought-juggling affects our ability to remember these thoughts. Here we show that competition between the neural representations of pictures in working memory can impair subsequent recognition of those pictures. We use pattern classifiers to decode functional magnetic resonance imaging (fMRI) data from a retro-cueing task where participants juggle two pictures in working memory. Trial-by-trial fluctuations in neural dynamics are predictive of performance on a surprise recognition memory test: trials that elicit similar levels of classifier evidence for both pictures (indicating close competition) are associated with worse memory performance than trials where participants switch decisively from thinking about one picture to the other. This result is consistent with the non-monotonic plasticity hypothesis, which predicts that close competition can trigger weakening of memories that lose the competition, leading to subsequent forgetting.

Competition between items in working memory leads to forgetting

PubMed Central

Lewis-Peacock, Jarrod A.; Norman, Kenneth A.

2014-01-01

Switching attention from one thought to the next propels our mental lives forward. However, it is unclear how this thought-juggling affects our ability to remember these thoughts. Here we show that competition between the neural representations of pictures in working memory can impair subsequent recognition of those pictures. We use pattern classifiers to decode functional magnetic resonance imaging (fMRI) data from a retro-cueing task where participants juggle two pictures in working memory. Trial-by-trial fluctuations in neural dynamics are predictive of performance on a surprise recognition memory test: trials that elicit similar levels of classifier evidence for both pictures (indicating close competition) are associated with worse memory performance than trials where participants switch decisively from thinking about one picture to the other. This result is consistent with the non-monotonic plasticity hypothesis, which predicts that close competition can trigger weakening of memories that lose the competition, leading to subsequent forgetting. PMID:25519874

Mouth rinsing with a carbohydrate solution does not influence cycle time trial performance in the heat.

PubMed

Watson, Phillip; Nichols, David; Cordery, Philip

2014-09-01

Ten endurance-trained males were recruited to examine the possible role of carbohydrate (CHO) receptors in the mouth influencing exercise performance in the heat. Volunteers completed an incremental test to exhaustion to determine peak oxygen uptake, a familiarisation trial, followed by 2 experimental trials. Trials consisted of a 1-h time trial undertaken in a climatic chamber maintained at 30 °C, 60% relative humidity. Immediately before, and at regular intervals throughout exercise, subjects ingested a bolus of water and then were provided with either a placebo (PLA) or a 6.4% glucose (CHO) solution to rinse in the mouth for 10 s before being expectorated. There was no difference in total work done between the PLA and CHO trials (758.8 ± 149.0 kJ; 762.6 ± 141.1 kJ; P = 0.951). Pacing was also similar, with no differences in power output apparent during the experimental trials (P = 0.546). Core temperature (P = 0.615), heart rate (P = 0.505), ratings of perceived exertion (P = 0.181), and perceived thermal stress (P = 0.416) were not influenced by the nature of the intervention. Blood glucose concentrations were similar during the CHO and PLA trials (P = 0.117). In contrast to the findings of several studies undertaken in temperate conditions, the present investigation failed to support role of oral sensing of CHO in influencing performance during prolonged exercise in warm conditions.

Interaction between motor ability and skill learning in children: Application of implicit and explicit approaches.

PubMed

Maxwell, Jon P; Capio, Catherine M; Masters, Rich S W

2017-05-01

The benefits of implicit and explicit motor learning approaches in young adults have been studied extensively, but much less in children. This study investigated the relationship between fundamental motor ability and implicit/explicit learning in children using the errorless learning paradigm. First, the motor ability of 261 children (142 boys, 119 girls) aged 9-12 years (M = 9.74, SD = 0.67) was measured. Second, children with motor ability scores in the upper and lower quartile learned a golf-putting skill in either an errorless (implicit) or errorful (explicit) learning condition. Four groups were formed: Errorless High-Ability (n = 13), Errorless Low-Ability (n = 11), Errorful High-Ability (n = 10), and Errorful Low-Ability (n = 11). Learning consisted of 300 practice trials, while testing included a 50-trial retention test, followed by a 50-trial secondary task transfer test, and another 50-trial retention test. The results showed that for high- and low-ability errorless learners, motor performance was unaffected by the secondary task, as was the case for high-ability errorful learners. Low-ability errorful learners performed worse with a secondary task and were significantly poorer than the corresponding high-ability group. These results suggest that implicit motor learning (errorless) may be beneficial for children with low motor ability. The findings also show a trend that children of high motor ability might benefit from learning explicitly (errorful). Further research is recommended to examine the compatibility of implicit and explicit approaches for children of different abilities.

Does the addition of hip strengthening exercises improve outcomes following total knee arthroplasty? A study protocol for a randomized trial.

PubMed

Schache, Margaret B; McClelland, Jodie A; Webster, Kate E

2016-06-13

Total knee arthroplasty (TKA) is effective in reducing pain and improving function for end-stage knee osteoarthritis. However, muscle weakness and functional limitations persist despite assistance from post-operative rehabilitation programs that traditionally focus on quadriceps strengthening and range of movement exercises. Hip abductor muscle weakness is evident in knee osteoarthritis and hip muscle strengthening reduces knee pain in this group. Following TKA, people with weak hip abductor strength perform more poorly on measures of physical function. However, very little is known of the effectiveness of including hip abductor strengthening exercises in post-operative rehabilitation. The aim of this trial is to compare the effects of targeted hip abductor strengthening to those of traditional care in a TKA rehabilitation program on muscle strength, patient reported outcomes and functional performance measures. This protocol describes a single-blinded randomized controlled trial, where 104 participants referred for inpatient rehabilitation following TKA will be recruited. Participants will be randomized using computer-generated numbers to one of two groups: usual care or usual care with additional hip strengthening exercises. Participants will attend physiotherapy daily during their inpatient length of stay, and will then attend between six and eight physiotherapy sessions as an outpatient. Primary outcomes are isometric hip abductor strength and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Secondary outcomes are stair climb test, 6 min walk test, timed up and go, 40 m fast-paced walk test, 30 second chair stand test, isometric quadriceps strength, Lower Extremity Functional Scale (LEFS) and SF-12. Outcome measures will be recorded at baseline (admission to inpatient rehabilitation), and then 3 weeks, 6 weeks and 6 months post admission to rehabilitation. The findings of this study will determine whether the addition of targeted hip strengthening to usual care rehabilitation improves physical performance and patient reported outcomes following TKA when compared to usual care rehabilitation. This will then determine whether targeted hip strengthening exercises should be included in traditional rehabilitation programs to improve the outcomes following total knee arthroplasty. The trial protocol was registered with the Australian Clinical Trial Registry ( ACTRN12615000863538 ) on 18 August 2015.

Who Benefits From Adjuvant Radiation Therapy for Gastric Cancer? A Meta-Analysis

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

Ohri, Nitin, E-mail: ohri.nitin@gmail.com; Garg, Madhur K.; Aparo, Santiago

2013-06-01

Purpose: Large randomized trials have demonstrated significant survival benefits with the use of adjuvant chemotherapy or chemoradiation therapy for gastric cancer. The importance of adjuvant radiation therapy (RT) remains unclear. We performed an up-to-date meta-analysis of randomized trials testing the use of RT for resectable gastric cancer. Methods and Materials: We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for randomized trials testing adjuvant (including neoadjuvant) RT for resectable gastric cancer. Hazard ratios describing the impact of adjuvant RT on overall survival (OS) and disease-free survival (DFS) were extracted directly from the original studies or calculated frommore » survival curves. Pooled estimates were obtained using the inverse variance method. Subgroup analyses were performed to determine whether the efficacy of RT varies with chemotherapy use, RT timing, geographic region, type of nodal dissection performed, or lymph node status. Results: Thirteen studies met all inclusion criteria and were used for this analysis. Adjuvant RT was associated with a significant improvement in both OS (HR = 0.78, 95% CI: 0.70-0.86, P<.001) and DFS (HR = 0.71, 95% CI: 0.63-0.80, P<.001). In the 5 studies that tested adjuvant chemoradiation therapy against adjuvant chemotherapy, similar effects were seen for OS (HR = 0.83, 95% CI: 0.67-1.03, P=.087) and DFS (HR = 0.77, 95% CI: 0.91-0.65, P=.002). Available data did not reveal any subgroup of patients that does not benefit from adjuvant RT. Conclusion: In randomized trials for resectable gastric cancer, adjuvant RT provides an approximately 20% improvement in both DFS and OS. Available data do not reveal a subgroup of patients that does not benefit from adjuvant RT. Further study is required to optimize the implementation of adjuvant RT for gastric cancer with regard to patient selection and integration with systemic therapy.« less

Validation of the DIFFAL, HPAC and HotSpot Dispersion Models Using the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials Witness Plate Deposition Dataset.

PubMed

Purves, Murray; Parkes, David

2016-05-01

Three atmospheric dispersion models--DIFFAL, HPAC, and HotSpot--of differing complexities have been validated against the witness plate deposition dataset taken during the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials. The small-scale nature of these trials in comparison to many other historical radiological dispersion trials provides a unique opportunity to evaluate the near-field performance of the models considered. This paper performs validation of these models using two graphical methods of comparison: deposition contour plots and hotline profile graphs. All of the models tested are assessed to perform well, especially considering that previous model developments and validations have been focused on larger-scale scenarios. Of the models, HPAC generally produced the most accurate results, especially at locations within ∼100 m of GZ. Features present within the observed data, such as hot spots, were not well modeled by any of the codes considered. Additionally, it was found that an increase in the complexity of the meteorological data input to the models did not necessarily lead to an improvement in model accuracy; this is potentially due to the small-scale nature of the trials.

Validity and reliability of a new ankle dorsiflexion measurement device.

PubMed

Gatt, Alfred; Chockalingam, Nachiappan

2013-08-01

The assessment of the maximum ankle dorsiflexion angle is an important clinical examination procedure. Evidence shows that the traditional goniometer is highly unreliable, and various designs of goniometers to measure the maximum ankle dorsiflexion angle rely on the application of a known force to obtain reliable results. Hence, an innovative ankle dorsiflexion measurement device was designed to make this measurement more reliable by holding the foot in a selected posture without the application of a known moment. To report on the comprehensive validity and reliability testing carried out on the new device. Following validity testing, four different trials to test reliability of the ankle dorsiflexion measurement device were performed. These trials included inter-rater and intra-rater testings with a controlled moment, intra-rater reliability testing with knees flexed and extended without a controlled moment, intra-rater testing with a patient population, and inter-rater reliability testing between four raters of varying experience without controlling moment. All raters were blinded. A series of trials to test intra-rater and inter-rater reliabilities. Intra-rater reliability intraclass correlation coefficient was 0.98 and inter-rater reliability intraclass correlation coefficient (2,1) was 0.953 with a controlled moment. With uncontrolled moment, very high reliability for intra-tester was also achieved (intraclass correlation coefficient = 0.94 with knees extended and intraclass correlation coefficient = 0.95 with knees flexed). For the trial investigating test-retest reliability with actual patients, intraclass correlation coefficient of 0.99 was obtained. In the trial investigating four different raters with uncontrolled moment, intraclass correlation coefficient of 0.91 was achieved. The new ankle dorsiflexion measurement device is a valid and reliable device for measuring ankle dorsiflexion in both healthy subjects and patients, with both controlled and uncontrolled moments, even by multiple raters of varying experience when the foot is dorsiflexed to its end of range of motion. An ankle dorsiflexion measuring device has been designed to increase the reliability of ankle dorsiflexion measurement and replace the traditional goniometer. While the majority of similar devices rely on application of a known moment to perform this measurement, it has been shown that this is not required with the new ankle dorsiflexion measurement device and, rather, foot posture should be taken into consideration as this affects the maximum ankle dorsiflexion angle.

Executive Functions Do Not Mediate Prospective Relations between Indices of Physical Activity and Academic Performance: The Active Smarter Kids (ASK) Study.

PubMed

Aadland, Katrine N; Ommundsen, Yngvar; Aadland, Eivind; Brønnick, Kolbjørn S; Lervåg, Arne; Resaland, Geir K; Moe, Vegard F

2017-01-01

Changes in cognitive function induced by physical activity have been proposed as a mechanism for the link between physical activity and academic performance. The aim of this study was to investigate if executive function mediated the prospective relations between indices of physical activity and academic performance in a sample of 10-year-old Norwegian children. The study included 1,129 children participating in the Active Smarter Kids (ASK) trial, followed over 7 months. Structural equation modeling (SEM) with a latent variable of executive function (measuring inhibition, working memory, and cognitive flexibility) was used in the analyses. Predictors were objectively measured physical activity, time spent sedentary, aerobic fitness, and motor skills. Outcomes were performance on national tests of numeracy, reading, and English (as a second language). Generally, indices of physical activity did not predict executive function and academic performance. A modest mediation effect of executive function was observed for the relation between motor skills and academic performance. Trial registration: Clinicaltrials.gov registry, trial registration number: NCT02132494.

Executive Functions Do Not Mediate Prospective Relations between Indices of Physical Activity and Academic Performance: The Active Smarter Kids (ASK) Study

PubMed Central

Aadland, Katrine N.; Ommundsen, Yngvar; Aadland, Eivind; Brønnick, Kolbjørn S.; Lervåg, Arne; Resaland, Geir K.; Moe, Vegard F.

2017-01-01

Changes in cognitive function induced by physical activity have been proposed as a mechanism for the link between physical activity and academic performance. The aim of this study was to investigate if executive function mediated the prospective relations between indices of physical activity and academic performance in a sample of 10-year-old Norwegian children. The study included 1,129 children participating in the Active Smarter Kids (ASK) trial, followed over 7 months. Structural equation modeling (SEM) with a latent variable of executive function (measuring inhibition, working memory, and cognitive flexibility) was used in the analyses. Predictors were objectively measured physical activity, time spent sedentary, aerobic fitness, and motor skills. Outcomes were performance on national tests of numeracy, reading, and English (as a second language). Generally, indices of physical activity did not predict executive function and academic performance. A modest mediation effect of executive function was observed for the relation between motor skills and academic performance. Trial registration: Clinicaltrials.gov registry, trial registration number: NCT02132494. PMID:28706500

Effects of oral sodium supplementation on indices of thermoregulation in trained, endurance athletes.

PubMed

Earhart, Elizabeth L; Weiss, Edward P; Rahman, Rabia; Kelly, Patrick V

2015-03-01

Guidelines recommend the consumption of sodium during exercise to replace losses in sweat; however, the effects of sodium on thermoregulation are less clear. To determine the effects of high-dose sodium supplementation on indices of thermoregulation and related outcomes, 11 endurance athletes participated in a double-blind, randomized-sequence, crossover study in which they underwent 2-hrs of endurance exercise at 60% heart rate reserve with 1800 mg of sodium supplementation (SS) during one trial and placebo (PL) during the other trial. A progressive intensity time-to-exhaustion test was performed after the 2-hr steady state exercise as an assessment of exercise performance. Sweat rate was calculated from changes in body weight, accounting for fluid intake and urinary losses. Ratings of perceived exertion (RPE) and heat stress were assessed using verbal numeric scales. Cardiovascular drift was determined from the rise in HR during the 2-hr steady state exercise test. Skin temperature was measured with an infrared thermometer. Dehydration occurred in both SS and PL trials, as evidenced by substantial weight loss (2.03 ± 0.43% and 2.27 ± 0.70%, respectively; p = 0.261 between trials). Sweat rate was 1015.53 ± 239.10 ml·hr(-1) during the SS trial and 1053.60±278.24 ml/hr during the PL trial, with no difference between trials (p = 0.459). Heat stress ratings indicated moderate heat stress ("warm/hot" ratings) but were not different between trials (p = 0.825). Time to exhaustion during the SS trial was 6.88 ± 3.88 minutes and during the PL trial averaged 6.96 ± 3.61 minutes, but did not differ between trials (p = 0.919). Cardiovascular drift, skin temperature, and RPE did not differ between trials (all p > 0.05). High-dose sodium supplementation does not appear to impact thermoregulation, cardiovascular drift, or physical performance in trained, endurance athletes. However, in light of the possibility that high sodium intakes might have other adverse effects, such as hypertension, it is our recommendation that athletes interpret professional recommendations for sodium needs during exercise with caution. Key pointsBased on current professional recommendations to replace sodium losses in sweat during exercise, some endurance athletes consume salt or other electrolyte supplements containing sodium during training and competition, however the effects of sodium on thermoregulation are less clear.High-dose sodium supplementation does not appear to impact thermoregulation, cardiovascular drift, or physical performance in trained, endurance athletes.The possibility remains that high sodium intakes might have other adverse effects. It is our recommendation that athletes interpret professional recommendations for sodium needs during exercise with caution.

Tolcapone-Enhanced Neurocognition in Healthy Adults: Neural Basis and Predictors.

PubMed

Bhakta, Savita G; Light, Gregory A; Talledo, Jo A; Balvaneda, Bryan; Hughes, Erica; Alvarez, Alexis; Rana, Brinda K; Young, Jared W; Swerdlow, Neal R

2017-12-01

Failure of procognitive drug trials in schizophrenia may reflect the clinical heterogeneity of schizophrenia, underscoring the need to identify biomarkers of treatment sensitivity. We used an experimental medicine design to test the procognitive effects of a putative procognitive agent, tolcapone, using an electroencephalogram-based cognitive control task in healthy subjects. Healthy men and women (n=27; ages 18-35 years), homozygous for either the Met/Met or Val/Val rs4680 genotype, received placebo and tolcapone 200 mg orally across 2 test days separated by 1 week in a double-blind, randomized, counterbalanced, within-subject design. On each test day, neurocognitive performance was assessed using the MATRICS Consensus Cognitive Battery and an electroencephalogram-based 5 Choice-Continuous Performance Test. Tolcapone enhanced visual learning in low-baseline MATRICS Consensus Cognitive Battery performers (d=0.35) and had an opposite effect in high performers (d=0.5), and enhanced verbal fluency across all subjects (P=.03) but had no effect on overall MATRICS Consensus Cognitive Battery performance. Tolcapone reduced false alarm rate (d=0.8) and enhanced frontal P200 amplitude during correctly identified nontarget trials (d=0.6) in low-baseline 5 Choice-Continuous Performance Test performers and had opposite effects in high performers (d=0.5 and d=0.25, respectively). Tolcapone's effect on frontal P200 amplitude and false alarm rate was correlated (rs=-0.4, P=.05). All neurocognitive effects of tolcapone were independent of rs4680 genotype. Tolcapone enhanced neurocognition and engaged electroencephalogram measures relevant to cognitive processes in specific subgroups of healthy individuals. These findings support an experimental medicine model for identifying procognitive treatments and provide a strong basis for future biomarker-informed procognitive studies in schizophrenia patients. © The Author 2017. Published by Oxford University Press on behalf of CINP.

Effects of scapulohumeral rehabilitation protocol on trunk control recovery in patients with subacute stroke: A pilot randomized controlled trial.

PubMed

Dell'Uomo, Daniela; Morone, Giovanni; Centrella, Antonio; Paolucci, Stefano; Caltagirone, Carlo; Grasso, Maria Grazia; Traballesi, Marco; Iosa, Marco

2017-01-01

Despite upper limb rehabilitation is widely investigated in patients with stroke, the effects of scapulohumeral rehabilitation on trunk stabillization are mainly unknown. To test the effects of scapulohumeral rehabilitation protocol on trunk control recovery in patients with subacute stroke. A pilot randomized controlled trial with two groups of 14 patients each one performing 20 minutes per day, 5 days a week, for 6 weeks in add on to standard therapy. Experimental group performed a specific scapulohumeral rehabilitation protocol aiming to improve trunk competencies whereas control group performed conventional arm rehabilitation. Clinical scale tests and accelerometric evaluations were performed pre- and post-treatment. Experimental groups showed better scores at discharge at Trunk impairment Scale (p < 0.001), Barthel Index (p = 0.024), Trunk Control Test (p = 0.002), Sitting Balance Scale (p = 0.002), but neither at Fugl-Meyer Scale (p = 0.194) nor Modified Ashworth Scale (p = 0.114). Accelerometric analysis showed higher stability of trunk for experimental group especially during static and dynamic items. The recovery of scapulohumeral functions also acts on trunk stabilization post-stroke.

ELISA testing for common food antigens in four dry dog foods used in dietary elimination trials.

PubMed

Raditic, D M; Remillard, R L; Tater, K C

2011-02-01

This study evaluated four over the counter venison dry dog foods available from one on-line retail vendor for potential contamination with common known food allergens: soy, poultry or beef. An amplified, double sandwich type enzyme linked immunosorbent assay (ELISA) test of soy, poultry and beef proteins were performed by an independent accredited food laboratory. The ELISA test for poultry protein was found to be unreliable when testing in dry dog foods because false negatives occurred. ELISA testing of control diets for both soy and beef proteins performed as expected and could be useful in antigen testing in dry dog foods. Three of the four over the counter (OTC) venison canine dry foods with no soy products named in the ingredient list were ELISA positive for soy; additionally one OTC diet tested positive for beef protein with no beef products listed as an ingredient list. One OTC venison diet was not found to be positive for soy, poultry or beef proteins. However, none of the four OTC venison diets could be considered suitable for a diagnostic elimination trial as they all contained common pet food proteins, some of which were readily identifiable on the label and some that were only detected by ELISA. Therefore, if the four OTC venison products selected in this study are representative of OTC products in general, then the use of OTC venison dry dog foods should not be used during elimination trials in suspected food allergy patients. © 2010 Blackwell Verlag GmbH.

Development and marketing of a prosthetic urinary control valve system

NASA Technical Reports Server (NTRS)

Tenney, J. B., Jr.; Rabinowitz, R.; Rogers, D. W.; Harrison, H. N.

1983-01-01

An implantable prosthetic for the control of urinary incontinence was developed and marketed. Three phases are presented: bench development studies, animal trials, and human clinical trials. This work was performed under the direction of a Research Team at Rochester General Hospital (RGH). Bench trials were completed on prototype hardware and provided early verification of the device's ability to withstand repeated cyclic testing. Configurational variants were evaluated and a preferred design concept was established. Silicone rubber (medical grade) was selected as the preferred material for the prosthesis.

Pacing Strategy in Short Cycling Time Trials.

PubMed

de Jong, Jelle; van der Meijden, Linda; Hamby, Simone; Suckow, Samantha; Dodge, Christopher; de Koning, Jos J; Foster, Carl

2015-11-01

To reach top performance in cycling, optimizing distribution of energy resources is crucial. The purpose of this study was to investigate power output during 250-m, 500-m, and 1000-m cycling time trials and the characteristics of the adopted pacing strategy. Nine trained cyclists completed an incremental test and 3 time trials that they were instructed to finish as quickly as possible. Preceding the trials, peak power during short sprints (PP sprint) and gross efficiency (GE) were measured. During the trials, power output and oxygen consumption were measured to calculate the contribution of the aerobic and anaerobic energy sources. After the trial GE was measured again. Peak power during all trials (PPTT) was lower than PP sprint. In the 250-m trial the PPTT was higher in the 1000-m trial (P = .008). The subjects performed a significantly longer time at high intensity in the 250-m than in the 1000-m (P = .029). GE declined significantly during all trials (P < .01). Total anaerobically attributable work was less in the 250-m than in the 500-m (P = .015) and 1000-m (P < .01) trials. The overall pacing pattern in the 250-m trial appears to follow an all-out strategy, although peak power is still lower than the potential maximal power output. This suggests that a true all-out pattern of power output may not be used in fixed-distance events. The 500-m and 1000-m had a more conservative pacing pattern and anaerobic power output reached a constant magnitude.

Exercise in Patients on Dialysis: A Multicenter, Randomized Clinical Trial

PubMed Central

Manfredini, Fabio; Mallamaci, Francesca; D’Arrigo, Graziella; Baggetta, Rossella; Bolignano, Davide; Torino, Claudia; Lamberti, Nicola; Bertoli, Silvio; Ciurlino, Daniele; Rocca-Rey, Lisa; Barillà, Antonio; Battaglia, Yuri; Rapanà, Renato Mario; Zuccalà, Alessandro; Bonanno, Graziella; Fatuzzo, Pasquale; Rapisarda, Francesco; Rastelli, Stefania; Fabrizi, Fabrizio; Messa, Piergiorgio; De Paola, Luciano; Lombardi, Luigi; Cupisti, Adamasco; Fuiano, Giorgio; Lucisano, Gaetano; Summaria, Chiara; Felisatti, Michele; Pozzato, Enrico; Malagoni, Anna Maria; Castellino, Pietro; Aucella, Filippo; Abd ElHafeez, Samar; Provenzano, Pasquale Fabio; Tripepi, Giovanni; Catizone, Luigi

2017-01-01

Previous studies have suggested the benefits of physical exercise for patients on dialysis. We conducted the Exercise Introduction to Enhance Performance in Dialysis trial, a 6-month randomized, multicenter trial to test whether a simple, personalized walking exercise program at home, managed by dialysis staff, improves functional status in adult patients on dialysis. The main study outcomes included change in physical performance at 6 months, assessed by the 6-minute walking test and the five times sit-to-stand test, and in quality of life, assessed by the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire. We randomized 296 patients to normal physical activity (control; n=145) or walking exercise (n=151); 227 patients (exercise n=104; control n=123) repeated the 6-month evaluations. The distance covered during the 6-minute walking test improved in the exercise group (mean distance±SD: baseline, 328±96 m; 6 months, 367±113 m) but not in the control group (baseline, 321±107 m; 6 months, 324±116 m; P<0.001 between groups). Similarly, the five times sit-to-stand test time improved in the exercise group (mean time±SD: baseline, 20.5±6.0 seconds; 6 months, 18.2±5.7 seconds) but not in the control group (baseline, 20.9±5.8 seconds; 6 months, 20.2±6.4 seconds; P=0.001 between groups). The cognitive function score (P=0.04) and quality of social interaction score (P=0.01) in the kidney disease component of the KDQOL-SF improved significantly in the exercise arm compared with the control arm. Hence, a simple, personalized, home-based, low-intensity exercise program managed by dialysis staff may improve physical performance and quality of life in patients on dialysis. PMID:27909047

Evaluation of a device for standardized measurements of reading performance in a prepresbyopic population.

PubMed

Arad, Tschingis; Baumeister, Martin; Bühren, Jens; Kohnen, Thomas

2017-04-20

Automated measurements of reading performance are required for clinical trials involving presbyopia-correcting surgery options. Repeatability of a testing device for reading (Salzburg Reading Desk) was evaluated in a prepresbyopic population. Subjective reading performance of 50 subjects divided into 2 age groups (23-30 years and 38-49 years) with distance-corrected eyes was investigated with different log-scaled reading charts. At study entry, refractive parameters were measured and distance visual acuity assessed. Two standardized binocular measurements were performed for each subject (32.24 ± 9.87 days apart [mean ± SD]). The repeatability of the tests was estimated using correlation coefficients, Wilcoxon signed-rank test, and Bland-Altman method. The test parameters at both maximum reading rate (MRR) measurements demonstrate a strong relationship of age group 2 subjects (correlation coefficient [r] = 0.74 p = 10-4) and of younger subjects (age group 1: r = 0.69, p = 10-4). Prepresbyopic subjects of age group 2 showed moderate results for near reading distance (r = 0.67, p = 10-4); by contrast, younger subjects had poorer results (r = 0.55, p = 10-3). The Wilcoxon signed-rank test revealed agreement between measurements and Bland-Altman plots showed a wide data spread for MRR and near reading distance in both groups. The device measures repeatedly selected reading performance parameters of near real world conditions, such as MRR, in prepresbyopic populations if several factors are taken into account. The option to choose preferred distance leads to more variance in measuring repeated reading performance. German Clinical Trials Register (DRKS) registration reference number: DRKS00000784.

Crewmember Performance Before, During, And After Spaceflight

PubMed Central

Kelly, Thomas H; Hienz, Robert D; Zarcone, Troy J; Wurster, Richard M; Brady, Joseph V

2005-01-01

The development of technologies for monitoring the welfare of crewmembers is a critical requirement for extended spaceflight. Behavior analytic methodologies provide a framework for studying the performance of individuals and groups, and brief computerized tests have been used successfully to examine the impairing effects of sleep, drug, and nutrition manipulations on human behavior. The purpose of the present study was to evaluate the feasibility and sensitivity of repeated performance testing during spaceflight. Four National Aeronautics and Space Administration crewmembers were trained to complete computerized questionnaires and performance tasks at repeated regular intervals before and after a 10-day shuttle mission and at times that interfered minimally with other mission activities during spaceflight. Two types of performance, Digit-Symbol Substitution trial completion rates and response times during the most complex Number Recognition trials, were altered slightly during spaceflight. All other dimensions of the performance tasks remained essentially unchanged over the course of the study. Verbal ratings of Fatigue increased slightly during spaceflight and decreased during the postflight test sessions. Arousal ratings increased during spaceflight and decreased postflight. No other consistent changes in rating-scale measures were observed over the course of the study. Crewmembers completed all mission requirements in an efficient manner with no indication of clinically significant behavioral impairment during the 10-day spaceflight. These results support the feasibility and utility of computerized task performances and questionnaire rating scales for repeated measurement of behavior during spaceflight. PMID:16262187

Time-trial Performance in Elite Speed Skaters After Remote Ischemic Preconditioning.

PubMed

Richard, Philippe; Billaut, François

2018-05-10

Speed skating leads to blood-flow restriction and deoxygenation in the lower limbs (especially the right leg) that may affect performance. Although the acute influence of such deoxygenation is not clearly understood, we tested whether remote ischemic preconditioning (RIPC) could modify muscular oxygenation and improve time-trial performance in that sport. Using a randomized, single-blind, placebo-controlled, crossover design, 9 elite speed skaters performed 1000-m on-ice time-trials preceded by either RIPC of the upper limbs (3x5-min compression/5-min reperfusion cycles at 30 mmHg > arterial systolic pressure) or SHAM (10 mmHg). Changes in tissue saturation index (TSI), oxyhemoglobin-oxymyoglobine ([O2HbMb]), deoxyhemoglobin-deoxymyoglobine ([HHbMb]) and total hemoglobin-myoglobine ([THbMb]) in the right vastus lateralis muscle were monitored by near-infrared spectroscopy (NIRS). Differences between RIPC and SHAM were analyzed using Cohen's effect size (ES) ± 90% confidence limits and magnitude-based inferences. Compared with SHAM, RIPC had negligible effect on performance and NIRS variables. However, in a subgroup of sprinters (n=5) RIPC likely lowered TSI at the beginning of the time-trial (-6.1%; ES -0.65) and likely increased [HHbMb] at the beginning (3%; ES 0.39), middle (2.9%; ES 0.37) and end of the trial (-2.1%, ES 0.27). In the middle section of the trial, these metabolic changes were concomitant with a possible increase in [THbMb]. RIPC has no practical ergogenic impact on 1000-m long-track speed-skating performance in elite athletes. The relevance of using RIPC during training to increase physiological stress in sprinters particularly deserves further investigation.

Relationships between authorship contributions and authors' industry financial ties among oncology clinical trials.

PubMed

Rose, Susannah L; Krzyzanowska, Monika K; Joffe, Steven

2010-03-10

PURPOSE To test the hypothesis that authors who play key scientific roles in oncology clinical trials, and who therefore have increased influence over the design, analysis, interpretation or reporting of trials, are more likely than those who do not play such roles to have financial ties to industry. METHODS Data were abstracted from all trials (n = 235) of drugs or biologic agents published in the Journal of Clinical Oncology between January 1, 2006 and June 30, 2007. Article-level data included sponsorship, age group (adult v pediatric), phase, single versus multicenter, country (United States v other), and number of authors. Author-level data (n = 2,927) included financial ties (eg, employment, consulting) and performance of key scientific roles (ie, conception/design, analysis/interpretation, or manuscript writing). Associations between performance of key roles and financial ties, adjusting for article-level covariates, were examined using generalized linear mixed models. Results One thousand eight hundred eighty-one authors (64%) reported performing at least one key role, and 842 authors (29%) reported at least one financial tie. Authors who reported performing a key role were more likely than other authors to report financial ties to industry (adjusted odds ratio [OR], 4.3; 99% CI, 3.0 to 6.0; P < .0001). The association was stronger among trials with, compared with those without, industry funding (OR, 5.0 [99% CI, 3.4 to 7.5] v OR, 2.5 [99% CI, 1.3 to 4.8]), but was present regardless of sponsorship. CONCLUSION Authors who perform key roles in the conception and design, analysis, and interpretation, or reporting of oncology clinical trials are more likely than authors who do not perform such roles to have financial ties to industry.

Relationships Between Authorship Contributions and Authors' Industry Financial Ties Among Oncology Clinical Trials

PubMed Central

Rose, Susannah L.; Krzyzanowska, Monika K.; Joffe, Steven

2010-01-01

Purpose To test the hypothesis that authors who play key scientific roles in oncology clinical trials, and who therefore have increased influence over the design, analysis, interpretation or reporting of trials, are more likely than those who do not play such roles to have financial ties to industry. Methods Data were abstracted from all trials (n = 235) of drugs or biologic agents published in the Journal of Clinical Oncology between January 1, 2006 and June 30, 2007. Article-level data included sponsorship, age group (adult v pediatric), phase, single versus multicenter, country (United States v other), and number of authors. Author-level data (n = 2,927) included financial ties (eg, employment, consulting) and performance of key scientific roles (ie, conception/design, analysis/interpretation, or manuscript writing). Associations between performance of key roles and financial ties, adjusting for article-level covariates, were examined using generalized linear mixed models. Results One thousand eight hundred eighty-one authors (64%) reported performing at least one key role, and 842 authors (29%) reported at least one financial tie. Authors who reported performing a key role were more likely than other authors to report financial ties to industry (adjusted odds ratio [OR], 4.3; 99% CI, 3.0 to 6.0; P < .0001). The association was stronger among trials with, compared with those without, industry funding (OR, 5.0 [99% CI, 3.4 to 7.5] v OR, 2.5 [99% CI, 1.3 to 4.8]), but was present regardless of sponsorship. Conclusion Authors who perform key roles in the conception and design, analysis, and interpretation, or reporting of oncology clinical trials are more likely than authors who do not perform such roles to have financial ties to industry. PMID:20065190

Transfer of learning on a spatial memory task between the blind and sighted people.

PubMed

Akpinar, Selcuk; Popović, Stevo; Kirazci, Sadettin

2012-12-01

The purpose of this study was to analyze the effect of two different types of feedback on a spatial memory task between the blind and blindfolded-sighted participants. Participants tried to estimate the predetermined distance by using their dominant hands. Both blind and blindfolded-sighted groups were randomly divided into two feedback subgroups as "100% frequency" and "10% bandwidth". The score of the participants was given verbally to the participants as knowledge of results (KR). The target distance was set as 60 cm. Sixty acquisition trials were performed in 4 sets each including 15 repetition afterwards immediate and delayed retention tests were undertaken. Moreover, 24 hours past the delayed retention test, the participants completed 15 no-KR trials as a transfer test (target distance was 30 cm). The results of the statistical analyses revealed no significant differences for both acquisition and retention tests. However, a significant difference was found at transfer test. 100% frequency blind group performed significantly less accurate than all other groups. As a result, it can be concluded that different types of feedback have similar effect on spatial memory task used in this study. However, types of feedback can change the performance of accuracy on transferring this skill among the blind.

Influence of different types of mouthguards on strength and performance of collegiate athletes: a controlled-randomized trial.

PubMed

Duddy, Fergus A; Weissman, Jake; Lee, Rich A; Paranjpe, Avina; Johnson, James D; Cohenca, Nestor

2012-08-01

Prevention of traumatic dental injuries relies on the identification of etiologic factors and the use of protective devices during contact sports. Mouthguards are considered to be an effective and cost-efficient device aimed at buffering the impacts or blows that might otherwise cause moderate to severe dental and maxillofacial injuries. Interestingly, besides their role in preventing injury, some authors claim that mouthguards can enhance athletic performance. Thus, the purpose of this controlled randomized trial was to evaluate and compare the effect of two different types of mouthguards on the athletic performance and strength of collegiate athletes. Eighteen college athletes ranging from 19 to 23 years participated in this study. Devices tested in this study included an over-the-counter boil-and-bite mouthguard (O-Flow™ Max Under Armour®) (UA) and a custom-made mouthguard (CM). Physical tests were carefully selected by the head athletic trainer and aimed at evaluating the strength and performance. The following sequence was carried out on each test day: (i) 3-stroke maximum power ergometer test, (ii) 1-min ergometer test, and (iii) a 1600-m run. A random assignment was developed to test all three experimental groups on each test day. Following the tests, each athlete completed a brief anonymous survey aimed at evaluating the athletes' overall satisfaction with each type of mouthguard. Custom-made mouthguards had no detrimental effect on athletic strength and performance and were reported by the athletes as being comfortable and not causing difficulty in breathing. In contrast, boil-and-bite mouthguards did not perform as well and were reported as being uncomfortable and causing breathing difficulties. Based on the results of this study, the use of custom-made mouthguards should be encouraged in contact sports as a protective measure, without concern for any negative effect on the athletic performance of the athletes. © 2012 John Wiley & Sons A/S.

The relative responsiveness of test instruments can be estimated using a meta-analytic approach: an illustration with treatments for depression.

PubMed

Kounali, Daphne Z; Button, Katherine S; Lewis, Glyn; Ades, Anthony E

2016-09-01

We present a meta-analytic method that combines information on treatment effects from different instruments from a network of randomized trials to estimate instrument relative responsiveness. Five depression-test instruments [Beck Depression Inventory (BDI I/II), Patient Health Questionnaire (PHQ9), Hamilton Rating for Depression 17 and 24 items, Montgomery-Asberg Depression Rating] and three generic quality of life measures [EuroQoL (EQ-5D), SF36 mental component summary (SF36 MCS), and physical component summary (SF36 PCS)] were compared. Randomized trials of treatments for depression reporting outcomes on any two or more of these instruments were identified. Information on the within-trial ratios of standardized treatment effects was pooled across the studies to estimate relative responsiveness. The between-instrument ratios of standardized treatment effects vary across trials, with a coefficient of variation of 13% (95% credible interval: 6%, 25%). There were important differences between the depression measures, with PHQ9 being the most responsive instrument and BDI the least. Responsiveness of the EQ-5D and SF36 PCS was poor. SF36 MCS performed similarly to depression instruments. Information on relative responsiveness of several test instruments can be pooled across networks of trials reporting at least two outcomes, allowing comparison and ranking of test instruments that may never have been compared directly. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of Blended Instructional Models on Math Performance

ERIC Educational Resources Information Center

Bottge, Brian A.; Ma, Xin; Gassaway, Linda; Toland, Michael D.; Butler, Mark; Cho, Sun-Joo

2014-01-01

A pretest-posttest cluster-randomized trial involving 31 middle schools and 335 students with disabilities tested the effects of combining explicit and anchored instruction on fraction computation and problem solving. Results of standardized and researcher-developed tests showed that students who were taught with the blended units outscored…

Judgments of learning are significantly higher following feedback on relatively good versus relatively poor trials despite no actual learning differences.

PubMed

Carter, Michael J; Smith, Victoria; Ste-Marie, Diane M

2016-02-01

Studies have consistently shown that prospective metacognitive judgments of learning are often inaccurate because humans mistakenly interpret current performance levels as valid indices of learning. These metacognitive discrepancies are strongly related to conditions of practice. Here, we examined how the type of feedback (after good versus poor trials) received during practice and awareness (aware versus unaware) of this manipulation affected judgments of learning and actual learning. After each six-trial block, participants received feedback on their three best trials or three worst trials and half of the participants were made explicitly aware of the type of feedback they received while the other half were unaware. Judgments of learning were made at the end of each six-trial block and before the 24-h retention test. Results indicated no motor performance differences between groups in practice or retention; however, receiving feedback on relatively good compared to relatively poor trials resulted in significantly higher judgments of learning in practice and retention, irrespective of awareness. These results suggest that KR on relatively good versus relatively poor trials can have dissociable effects on judgments of learning in the absence of actual learning differences, even when participants are made aware of their feedback manipulation. Copyright © 2015 Elsevier B.V. All rights reserved.

PROspective Multicenter Imaging Study for Evaluation of chest pain: rationale and design of the PROMISE trial.

PubMed

Douglas, Pamela S; Hoffmann, Udo; Lee, Kerry L; Mark, Daniel B; Al-Khalidi, Hussein R; Anstrom, Kevin; Dolor, Rowena J; Kosinski, Andrzej; Krucoff, Mitchell W; Mudrick, Daniel W; Patel, Manesh R; Picard, Michael H; Udelson, James E; Velazquez, Eric J; Cooper, Lawton

2014-06-01

Suspected coronary artery disease (CAD) is one of the most common, potentially life-threatening diagnostic problems clinicians encounter. However, no large outcome-based randomized trials have been performed to guide the selection of diagnostic strategies for these patients. The PROMISE study is a prospective, randomized trial comparing the effectiveness of 2 initial diagnostic strategies in patients with symptoms suspicious for CAD. Patients are randomized to either (1) functional testing (exercise electrocardiogram, stress nuclear imaging, or stress echocardiogram) or (2) anatomical testing with ≥64-slice multidetector coronary computed tomographic angiography. Tests are interpreted locally in real time by subspecialty certified physicians, and all subsequent care decisions are made by the clinical care team. Sites are provided results of central core laboratory quality and completeness assessment. All subjects are followed up for ≥1 year. The primary end point is the time to occurrence of the composite of death, myocardial infarction, major procedural complications (stroke, major bleeding, anaphylaxis, and renal failure), or hospitalization for unstable angina. More than 10,000 symptomatic subjects were randomized in 3.2 years at 193 US and Canadian cardiology, radiology, primary care, urgent care, and anesthesiology sites. Multispecialty community practice enrollment into a large pragmatic trial of diagnostic testing strategies is both feasible and efficient. The PROMISE trial will compare the clinical effectiveness of an initial strategy of functional testing against an initial strategy of anatomical testing in symptomatic patients with suspected CAD. Quality of life, resource use, cost-effectiveness, and radiation exposure will be assessed. Copyright © 2014 Mosby, Inc. All rights reserved.

PROspective Multicenter Imaging Study for Evaluation of Chest Pain: Rationale and Design of the PROMISE Trial

PubMed Central

Douglas, Pamela S.; Hoffmann, Udo; Lee, Kerry L.; Mark, Daniel B.; Al-Khalidi, Hussein R.; Anstrom, Kevin; Dolor, Rowena J.; Kosinski, Andrzej; Krucoff, Mitchell W.; Mudrick, Daniel W.; Patel, Manesh R.; Picard, Michael H.; Udelson, James E.; Velazquez, Eric J.; Cooper, Lawton

2014-01-01

Background Suspected coronary artery disease (CAD) is one of the most common, potentially life threatening diagnostic problems clinicians encounter. However, no large outcome-based randomized trials have been performed to guide the selection of diagnostic strategies for these patients. Methods The PROMISE study is a prospective, randomized trial comparing the effectiveness of two initial diagnostic strategies in patients with symptoms suspicious for CAD. Patients are randomized to either: 1) functional testing (exercise electrocardiogram, stress nuclear imaging, or stress echocardiogram); or 2) anatomic testing with >=64 slice multidetector coronary computed tomographic angiography. Tests are interpreted locally in real time by subspecialty certified physicians and all subsequent care decisions are made by the clinical care team. Sites are provided results of central core lab quality and completeness assessment. All subjects are followed for ≥1 year. The primary end-point is the time to occurrence of the composite of death, myocardial infarction, major procedural complications (stroke, major bleeding, anaphylaxis and renal failure) or hospitalization for unstable angina. Results Over 10,000 symptomatic subjects were randomized in 3.2 years at 193 US and Canadian cardiology, radiology, primary care, urgent care and anesthesiology sites. Conclusion Multi-specialty community practice enrollment into a large pragmatic trial of diagnostic testing strategies is both feasible and efficient. PROMISE will compare the clinical effectiveness of an initial strategy of functional testing against an initial strategy of anatomic testing in symptomatic patients with suspected CAD. Quality of life, resource use, cost effectiveness and radiation exposure will be assessed. Clinical trials.gov identifier NCT01174550 PMID:24890527

The distraction effects of phone use during a crucial driving maneuver.

PubMed

Hancock, P A; Lesch, M; Simmons, L

2003-07-01

Forty-two licensed drivers were tested in an experiment that required them to respond to an in-vehicle phone at the same time that they were faced with making a crucial stopping decision. Using test track facilities, we also examined the influence of driver gender and driver age on these dual-task response capacities. Each driver was given task practice and then performed a first block of 24 trials, where one trial represented one circuit of the test track. Half of the trials were control conditions in which neither the stop-light was activated nor was the in-vehicle phone triggered. Four trials required only stop-light response and a further four, phone response only. The remaining four trials required the driver to complete each task simultaneously. The order of presentation of specific trials was randomized and the whole sequence was repeated in a second block giving 48 trials per driver. In-vehicle phone response also contained an embedded memory task that was evaluated at the end of each trial circuit. Results confirmed our previous observation that in the dual-task condition there was a slower response to the light change. To compensate for this slowed response, drivers subsequently brake more intensely. Most importantly, we recorded a critical 15% increase in non-response to the stop-light in the presence of the phone distraction task which equates with increased stop-light violations on the open road. These response patterns varied by driver age and driver gender. In particular, age had a large effect on task components that required speed of response to multiple, simultaneous demands. Since driving represents a highly complex and interactive environment, it is not possible to specify a simplistic relationship between these distraction effects and outcome crash patterns. However, we can conclude that such in-vehicle technologies erode performance safety margin and distract drivers from their critical primary task of vehicle control. As such it can be anticipated that a causal relation exists to collision events. This is a crucial concern for all in-vehicle device designers and for the many safety researchers and professionals seeking to reduce the adverse impacts of vehicle collisions.

Beetroot juice does not enhance altitude running performance in well-trained athletes.

PubMed

Arnold, Josh Timothy; Oliver, Samuel James; Lewis-Jones, Tammy Maria; Wylie, Lee John; Macdonald, Jamie Hugo

2015-06-01

We hypothesized that acute dietary nitrate (NO3(-)) provided as concentrated beetroot juice supplement would improve endurance running performance of well-trained runners in normobaric hypoxia. Ten male runners (mean (SD): sea level maximal oxygen uptake, 66 (7) mL·kg(-1)·min(-1); 10 km personal best, 36 (2) min) completed incremental exercise to exhaustion at 4000 m and a 10-km treadmill time-trial at 2500 m simulated altitude on separate days after supplementation with ∼7 mmol NO3(-) and a placebo at 2.5 h before exercise. Oxygen cost, arterial oxygen saturation, heart rate, and ratings of perceived exertion (RPE) were determined during the incremental exercise test. Differences between treatments were determined using means [95% confidence intervals], paired sample t tests, and a probability of individual response analysis. NO3(-) supplementation increased plasma nitrite concentration (NO3(-), 473 (226) nmol·L(-1) vs. placebo, 61 (37) nmol·L(-1), P < 0.001) but did not alter time to exhaustion during the incremental test (NO3(-), 402 (80) s vs. placebo 393 (62) s, P = 0.5) or time to complete the 10-km time-trial (NO3(-), 2862 (233) s vs. placebo, 2874 (265) s, P = 0.6). Further, no practically meaningful beneficial effect on time-trial performance was observed as the 11 [-60 to 38] s improvement was less than the a priori determined minimum important difference (51 s), and only 3 runners experienced a "likely, probable" performance improvement. NO3(-) also did not alter oxygen cost, arterial oxygen saturation, heart rate, or RPE. Acute dietary NO3(-) supplementation did not consistently enhance running performance of well-trained athletes in normobaric hypoxia.

How to Evaluate Phase Differences between Trial Groups in Ongoing Electrophysiological Signals

PubMed Central

VanRullen, Rufin

2016-01-01

A growing number of studies endeavor to reveal periodicities in sensory and cognitive functions, by comparing the distribution of ongoing (pre-stimulus) oscillatory phases between two (or more) trial groups reflecting distinct experimental outcomes. A systematic relation between the phase of spontaneous electrophysiological signals, before a stimulus is even presented, and the eventual result of sensory or cognitive processing for that stimulus, would be indicative of an intrinsic periodicity in the underlying neural process. Prior studies of phase-dependent perception have used a variety of analytical methods to measure and evaluate phase differences, and there is currently no established standard practice in this field. The present report intends to remediate this need, by systematically comparing the statistical power of various measures of “phase opposition” between two trial groups, in a number of real and simulated experimental situations. Seven measures were evaluated: one parametric test (circular Watson-Williams test), and three distinct measures of phase opposition (phase bifurcation index, phase opposition sum, and phase opposition product) combined with two procedures for non-parametric statistical testing (permutation, or a combination of z-score and permutation). While these are obviously not the only existing or conceivable measures, they have all been used in recent studies. All tested methods performed adequately on a previously published dataset (Busch et al., 2009). On a variety of artificially constructed datasets, no single measure was found to surpass all others, but instead the suitability of each measure was contingent on several experimental factors: the time, frequency, and depth of oscillatory phase modulation; the absolute and relative amplitudes of post-stimulus event-related potentials for the two trial groups; the absolute and relative trial numbers for the two groups; and the number of permutations used for non-parametric testing. The concurrent use of two phase opposition measures, the parametric Watson-Williams test and a non-parametric test based on summing inter-trial coherence values for the two trial groups, appears to provide the most satisfactory outcome in all situations tested. Matlab code is provided to automatically compute these phase opposition measures. PMID:27683543

Evaluation of Performance and Perceptions of Electronic vs. Paper Multiple-Choice Exams

ERIC Educational Resources Information Center

Washburn, Shannon; Herman, James; Stewart, Randolph

2017-01-01

In the veterinary professional curriculum, methods of examination in many courses are transitioning from the traditional paper-based exams to electronic-based exams. Therefore, a controlled trial to evaluate the impact of testing methodology on examination performance in a veterinary physiology course was designed and implemented. Formalized…

20 CFR 404.1592 - The trial work period.

Code of Federal Regulations, 2014 CFR

2014-04-01

... which you may test your ability to work and still be considered disabled. It begins and ends as...); (ii) If you perform work demonstrating the ability to engage in substantial gainful activity during any required waiting period for benefits; (iii) If you perform work demonstrating the ability to...

20 CFR 404.1592 - The trial work period.

Code of Federal Regulations, 2012 CFR

2012-04-01

... which you may test your ability to work and still be considered disabled. It begins and ends as...); (ii) If you perform work demonstrating the ability to engage in substantial gainful activity during any required waiting period for benefits; (iii) If you perform work demonstrating the ability to...

20 CFR 404.1592 - The trial work period.

Code of Federal Regulations, 2013 CFR

2013-04-01

... which you may test your ability to work and still be considered disabled. It begins and ends as...); (ii) If you perform work demonstrating the ability to engage in substantial gainful activity during any required waiting period for benefits; (iii) If you perform work demonstrating the ability to...

How Imaging Can Impact Clinical Trial Design: Molecular Imaging as a Biomarker for Targeted Cancer Therapy.

PubMed

Mankoff, David A; Farwell, Michael D; Clark, Amy S; Pryma, Daniel A

2015-01-01

The ability to measure biochemical and molecular processes to guide cancer treatment represents a potentially powerful tool for trials of targeted cancer therapy. These assays have traditionally been performed by analysis of tissue samples. However, more recently, functional and molecular imaging has been developed that is capable of in vivo assays of cancer biochemistry and molecular biology and is highly complementary to tissue-based assays. Cancer imaging biomarkers can play a key role in increasing the efficacy and efficiency of therapeutic clinical trials and also provide insight into the biologic mechanisms that bring about a therapeutic response. Future progress will depend on close collaboration between imaging scientists and cancer physicians and on public and commercial sponsors, to take full advantage of what imaging has to offer for clinical trials of targeted cancer therapy. This review will provide examples of how molecular imaging can inform targeted cancer clinical trials and clinical decision making by (1) measuring regional expression of the therapeutic target, (2) assessing early (pharmacodynamic) response to treatment, and (3) predicting therapeutic outcome. The review includes a discussion of basic principles of molecular imaging biomarkers in cancer, with an emphasis on those methods that have been tested in patients. We then review clinical trials designed to evaluate imaging tests as integrated markers embedded in a therapeutic clinical trial with the goal of validating the imaging tests as integral markers that can aid patient selection and direct response-adapted treatment strategies. Examples of recently completed multicenter trials using imaging biomarkers are highlighted.

Does gymnastics practice improve vertical jump reliability from the age of 8 to 10 years?

PubMed

Marina, Michel; Torrado, Priscila

2013-01-01

The objective of this study was to confirm whether gymnastics practice from a young age can induce greater vertical jump reliability. Fifty young female gymnasts (8.84 ± 0.62 years) and 42 females in the control group (8.58 ± 0.92 years) performed the following jump tests on a contact mat: squat jump, countermovement jump, countermovement jump with arm swing and drop jump from heights of 40 and 60 cm. The two testing sessions had three trials each and were separated by one week. A 2 (groups) × 2 (sessions) × 3 (trials) repeated measures analysis of variance (ANOVA) and a test-retest correlation analysis were used to study the reliability. There was no systematic source of error in either group for non-plyometric jumps such as squat jump, countermovement jump, and countermovement jump with arm swing. A significant group per trial interaction revealed a learning effect in gymnasts' drop jumps from 40 cm height. Additionally, the test-retest correlation analysis and the higher minimum detectable error suggest that the quick drop jump technique was not fully consolidated in either group. At an introductory level of gymnastics and between the ages of 8-10 years, the condition of being a gymnast did not lead to conclusively higher reliability, aside from better overall vertical jump performance.

[Music as adjuvant therapy for coronary heart disease. Therapeutic music lowers anxiety, stress and beta-endorphin concentrations in patients from a coronary sport group].

PubMed

Vollert, J O; Störk, T; Rose, M; Möckel, M

2003-12-19

In a study with coronary patients it was estimated that music is able to lower stress and fear and contributing to relaxation in spite of physical exercise. 15 patients (13 male, two female, mean age 62,2 +/- 7,6 years) of a coronary sport unit were listening to an especially composed relaxation music while training their common heart-frequency adapted exercises. Before the exercises and after listening to music blood pressures were measured and blood was collected for determination of beta-endorphin. Simultaneous to blood collection the participants had to perform two psychometric test: the perceived stress experience questionnaire (PSQ) of Levenstein to measure the graduation of subjective perceived stress and the state-anxiety inquiry (STAI) of Spielberger as an indicator of coping. To practice the trial ("test trial"), the whole protocol was performed one week prior to the mean trial, but without listening to music and without blood collections and blood pressure measurements. In the test trial without music there were no significant changes in PSQ-data. In the mean trial, under the influence of music, values in the section "worries" decreased as a sign of lower worries (26.6 versus 27.6; p = 0.039). STAI-values were significantly lower as a sign of reduced fear after listening to music (31 versus 34; p = 0.045). beta-endorphin concentration (10.91 microg/l versus 15.96 microg/l, p = 0.044) and systolic blood pressure (130 mmHg versus 140 mmHg; p = 0.007) decreased significantly after listening to music. Regarding worries and fear, patients seemed to benefit by the intervention of music. beta-endorphin was lowered significantly after music despite physical activity.

Reliability of surface electromyography activity of gluteal and hamstring muscles during sub-maximal and maximal voluntary isometric contractions.

PubMed

Bussey, Melanie D; Aldabe, Daniela; Adhia, Divya; Mani, Ramakrishnan

2018-04-01

Normalizing to a reference signal is essential when analysing and comparing electromyography signals across or within individuals. However, studies have shown that MVC testing may not be as reliable in persons with acute and chronic pain. The purpose of this study was to compare the test-retest reliability of the muscle activity in the biceps femoris and gluteus maximus between a novel sub-MVC and standard MVC protocols. This study utilized a single individual repeated measures design with 12 participants performing multiple trials of both the sub-MVC and MVC tasks on two separate days. The participant position in the prone leg raise task was standardised with an ultrasonic sensor to improve task precession between trials/days. Day-to-day and trial-to-trial reliability of the maximal muscle activity was examined using ICC and SEM. Day-to-day and trial-to-trial reliability of the EMG activity in the BF and GM were high (0.70-0.89) to very high (≥0.90) for both test procedures. %SEM was <5-10% for both tests on a given day but higher in the day-to-day comparisons. The lower amplitude of the sub-MVC is a likely contributor to increased %SEM (8-13%) in the day-to-day comparison. The findings show that the sub-MVC modified prone double leg raise results in GM and BF EMG measures similar in reliability and precision to the standard MVC tasks. Therefore, the modified prone double leg raise may be a useful substitute for traditional MVC testing for normalizing EMG signals of the BF and GM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Beetroot Juice Supplementation Improves High-Intensity Intermittent Type Exercise Performance in Trained Soccer Players.

PubMed

Nyakayiru, Jean; Jonvik, Kristin L; Trommelen, Jorn; Pinckaers, Philippe J M; Senden, Joan M; van Loon, Luc J C; Verdijk, Lex B

2017-03-22

It has been shown that nitrate supplementation can enhance endurance exercise performance. Recent work suggests that nitrate ingestion can also increase intermittent type exercise performance in recreational athletes. We hypothesized that six days of nitrate supplementation can improve high-intensity intermittent type exercise performance in trained soccer players. Thirty-two male soccer players (age: 23 ± 1 years, height: 181 ± 1 m, weight: 77 ± 1 kg, playing experience: 15.2 ± 0.5 years, playing in the first team of a 2nd or 3rd Dutch amateur league club) participated in this randomized, double-blind cross-over study. All subjects participated in two test days in which high-intensity intermittent running performance was assessed using the Yo-Yo IR1 test. Subjects ingested nitrate-rich (140 mL; ~800 mg nitrate/day; BR) or a nitrate-depleted beetroot juice (PLA) for six subsequent days, with at least eight days of wash-out between trials. The distance covered during the Yo-Yo IR1 was the primary outcome measure, while heart rate (HR) was measured continuously throughout the test, and a single blood and saliva sample were collected just prior to the test. Six days of BR ingestion increased plasma and salivary nitrate and nitrite concentrations in comparison to PLA ( p < 0.001), and enhanced Yo-Yo IR1 test performance by 3.4 ± 1.3% (from 1574 ± 47 to 1623 ± 48 m; p = 0.027). Mean HR was lower in the BR (172 ± 2) vs. PLA trial (175 ± 2; p = 0.014). Six days of BR ingestion effectively improves high-intensity intermittent type exercise performance in trained soccer players.

Beetroot Juice Supplementation Improves High-Intensity Intermittent Type Exercise Performance in Trained Soccer Players

PubMed Central

Nyakayiru, Jean; Jonvik, Kristin L.; Trommelen, Jorn; Pinckaers, Philippe J. M.; Senden, Joan M.; van Loon, Luc J. C.; Verdijk, Lex B.

2017-01-01

It has been shown that nitrate supplementation can enhance endurance exercise performance. Recent work suggests that nitrate ingestion can also increase intermittent type exercise performance in recreational athletes. We hypothesized that six days of nitrate supplementation can improve high-intensity intermittent type exercise performance in trained soccer players. Thirty-two male soccer players (age: 23 ± 1 years, height: 181 ± 1 m, weight: 77 ± 1 kg, playing experience: 15.2 ± 0.5 years, playing in the first team of a 2nd or 3rd Dutch amateur league club) participated in this randomized, double-blind cross-over study. All subjects participated in two test days in which high-intensity intermittent running performance was assessed using the Yo-Yo IR1 test. Subjects ingested nitrate-rich (140 mL; ~800 mg nitrate/day; BR) or a nitrate-depleted beetroot juice (PLA) for six subsequent days, with at least eight days of wash-out between trials. The distance covered during the Yo-Yo IR1 was the primary outcome measure, while heart rate (HR) was measured continuously throughout the test, and a single blood and saliva sample were collected just prior to the test. Six days of BR ingestion increased plasma and salivary nitrate and nitrite concentrations in comparison to PLA (p < 0.001), and enhanced Yo-Yo IR1 test performance by 3.4 ± 1.3% (from 1574 ± 47 to 1623 ± 48 m; p = 0.027). Mean HR was lower in the BR (172 ± 2) vs. PLA trial (175 ± 2; p = 0.014). Six days of BR ingestion effectively improves high-intensity intermittent type exercise performance in trained soccer players. PMID:28327503

Development and implementation of an automated quantitative film digitizer quality control program

NASA Astrophysics Data System (ADS)

Fetterly, Kenneth A.; Avula, Ramesh T. V.; Hangiandreou, Nicholas J.

1999-05-01

A semi-automated, quantitative film digitizer quality control program that is based on the computer analysis of the image data from a single digitized test film was developed. This program includes measurements of the geometric accuracy, optical density performance, signal to noise ratio, and presampled modulation transfer function. The variability of the measurements was less than plus or minus 5%. Measurements were made on a group of two clinical and two laboratory laser film digitizers during a trial period of approximately four months. Quality control limits were established based on clinical necessity, vendor specifications and digitizer performance. During the trial period, one of the digitizers failed the performance requirements and was corrected by calibration.

The effects of dehydration, moderate alcohol consumption, and rehydration on cognitive functions.

PubMed

Irwin, Christopher; Leveritt, Michael; Shum, David; Desbrow, Ben

2013-05-01

This study investigated the impact of mild-moderate dehydration on alcohol-induced deteriorations in cognitive functions. Sixteen healthy males participated in a single-blind, placebo-controlled cross-over design study involving 4 experimental trials (separated by ≥7 d). In each trial, participants were dehydrated by 2.5% body mass through exercise. After 1 h recovery in a thermo-neutral environment (22 ± 2 °C, 60-70% relative humidity) 4 tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to the participants (test 1). In two of the trials, participants were provided with water equivalent to either 50% or 150% body mass loss and given salt (NaCl) capsules (50 mmol/L). A set volume of alcohol or placebo was then consumed in each trial, incorporating the conditions: dehydration-placebo (DP), dehydration-alcohol (DA), partial rehydration-alcohol (PA), and full rehydration-alcohol (FA). The same 4 CANTAB tasks were then re-administered (test 2). Subjective ratings of mood and estimates of alcohol intoxication and driving impairment were also recorded in each trial. Alcohol consumption caused deterioration on 3 of the 4 CANTAB measures (viz., choice reaction time, executive function and response inhibition). This reduction in performance was exacerbated when participants were dehydrated compared to trials where full rehydration occurred. Subjective ratings of impairment and intoxication were not significantly different between any of the trials where alcohol was consumed; however ratings for alcohol trials were significantly higher than in the placebo trial. These findings suggest that rehydration after exercise that causes fluid loss can attenuate alcohol-related deterioration of cognitive functions. This may pose implications for post match fluid replacement if a moderate amount of alcohol is also consumed. Copyright © 2013 Elsevier Inc. All rights reserved.

Enhancement of object-permanence performance in the Down's syndrome infant.

PubMed

Morss, J R

1984-01-01

Four infants with Down's syndrome (aged 19-33 months) were presented with a restructured version of an object-permanence task. Restructuring consisted of the embedding of single trials of the task within a sequence of simpler, related steps. Following failure on a standard presentation of the task, three Down's syndrome (DS) infants demonstrated success on trials embedded in the training sequence. Comparison was made with the performance of normal infants (aged 14-19 months) matched in terms of failure on the pre-test. Only two out of nine normal infants registered success on the embedded trials. Results are discussed in terms of the differences between the DS infant and the normal infant, and the former's reliance on the deliberate structuring of his learning environment by a parent or educator.

The White-test helps to reduce biliary leakage in liver resection: a systematic review and meta-analysis.

PubMed

Linke, Richard; Ulrich, Frank; Bechstein, Wolf O; Schnitzbauer, Andreas A

2015-01-01

Bile leakage testing may help to detect and reduce the incidence of biliary leakage after hepatic resection. This review was performed to investigate the value of the White-test in identifying intraoperative biliary leakage and avoiding postoperative leakage. A systematic review and meta-analysis was performed. Two researchers performed literature research. Primary outcome measure was the incidence of post-hepatectomy biliary leakage; secondary outcome measure was the ability of detecting intraoperative biliary leakage with the help of the White-test. A total of 4 publications (including original data from our center) were included in the analysis. Evidence levels of the included studies had medium quality of 2b (individual cohort studies including low quality randomized controlled trials). Use of the White-test led to a significant reduction of post-operative biliary leakage [OR: 0.3 (95% CI: 0.14, 0.63), p = 0.002] and led to a significant higher intraoperative detection of biliary leakages [OR: 0.03 (95%CI: 0.02, 0.07), p < 0.00001]. Existing evidence implicates the use of the White-test after hepatic resection to identify bile leaks intraoperatively and thus reduce incidence of post-operative biliary leakage. Nonetheless, there is a requirement for a high-quality randomized controlled trial with adequately powered sample-size to confirm findings from the above described studies and further increase evidence in this field.

Influence of a Pre-Exercise Glycerol Hydration Beverage on Performance and Physiologic Function During Mountain-Bike Races in the Heat

PubMed Central

Wingo, Jonathan E.; Berger, Erik M.; Dellis, William O.; Knight, J. Chad; McClung, Joseph M.

2004-01-01

Objective: To determine if pre-exercise hydration with and without glycerol differentially affects physiologic and performance responses during mountain-bike races in the heat. Design and Setting: Testing (random, crossover, double-blind design) included the following 3 treatments administered in conjunction with a 30-mile mountain-bike race consisting of three 10-mile (16-km) loops: (1) no water during exercise (NE): water consumed before the race and no water consumed during the race, (2) glycerol (G): mixture of water and glycerol consumed before the race and water via 2 water bottles consumed during the race, and (3) water (W): water consumed before the race and water via 2 water bottles consumed during the race. Subjects stopped for 8 minutes after each 10-mile loop for collection of data. Subjects: Twelve heat-acclimated male mountain bikers with age = 24.5 ± 1.1 years, percentage of body fat = 14.3 ± 1.0%, mass = 76.9 ± 1.9 kg, height = 179 ± 2 cm. Measurements: We measured body weight, percentage of body fat, rectal temperature, blood lactate, blood glucose, urine volume, urine color, urine specific gravity, thirst sensation, thermal sensation, rating of perceived exertion, fluid consumption, heart rate, and sweat rate. Each subject completed the Environmental Symptoms Questionnaire. Results: The G trial was less dehydrated than the NE and W trials postexercise. Pre-exercise urine volume was less in the G trial than in the NE and W trials, and postexercise thirst was less in the G trial than the NE and W trials. Postexercise Environmental Symptoms Questionnaire scores were lower in the G trial than the NE or W trials. It is noteworthy that, although not significant, the G trial performed 5 minutes faster on loop 3 than the NE and W trials. Conclusions: Lower Environmental Symptoms Questionnaire scores and percentage of dehydration may indicate decreased signs and symptoms of heat strain in the G trial. Based on the NE trial performance, adequate pre-exercise hydration, even without glycerol, may limit the detrimental effects of dehydration. PMID:15173869

A simple but powerful test of perseverative search in dogs and toddlers.

PubMed

Péter, András; Gergely, Anna; Topál, József; Miklósi, Ádám; Pongrácz, Péter

2015-01-01

Perseverative (A-not-B) errors during the search of a hidden object were recently described in both dogs and 10-month-old infants. It was found that ostensive cues indicating a communicative intent of the person who hides the object played a major role in eliciting perseverative errors in both species. However, the employed experimental set-up gave rise to several alternative explanations regarding the source of these errors. Here we present a simplified protocol that eliminates the ambiguities present in the original design. Using five consecutive object hiding events to one of two locations in a fixed order ("AABBA"), we tested adult companion dogs and human children (24 months old). The experimenter performed the hiding actions while giving ostensive cues in each trial and moved the target object to the given location in a straight line. Our results show that in the B trials, both 24-month-old children and dogs could not reliably find the hidden object, and their performance in the first B trials was significantly below that of any of the A trials. These results are the first to show that the tendency for perseverative errors in an ostensive-communicative context is a robust phenomenon among 2-year-old children and dogs, and not the by-product of a topographically elaborate hiding event.

Methods to Prove 20+ Year Life of CPV Products (in less than 20 Years)

NASA Astrophysics Data System (ADS)

Bowman, John; Spencer, Mark

2011-12-01

Due to the long term life expectations of photovoltaic products and the short duration of most introduced CPV technologies, it is critical for CPV companies to carefully construct field trials to prove product life. Because of the complicated geometric, thermal, and spectral characteristics of CPV systems, conducting very precise power output measurements reproducibly over many months is very difficult. Robust normalization methods specific to the exact optical system and PV cell type must be developed. Once the performance over a specific duration, e.g. one year, is established, then some justification is required to extrapolate to future performance. Comparisons to accelerated test results provide this justification. SolFocus has been conducting field trials of the SF-1100S CPV system for over two years. These field trials consist of controlled populations of SF-1100P modules, operating in grid-tied systems, which have been repeatedly measured at the individual module level over the duration of the trials. In this paper, field data will be presented along with normalization methodology and statistical methods for determining power degradation slope distributions for populations of individual modules. These results will be correlated with accelerated field tests which have been ongoing for 1.5 years and are estimated to be equivalent to 10 to 15 years of non-accelerated operation.

The DIAN-TU Next Generation Alzheimer’s prevention trial: adaptive design and disease progression model

PubMed Central

Bateman, Randall J.; Benzinger, Tammie L.; Berry, Scott; Clifford, David B.; Duggan, Cynthia; Fagan, Anne M.; Fanning, Kathleen; Farlow, Martin R.; Hassenstab, Jason; McDade, Eric M.; Mills, Susan; Paumier, Katrina; Quintana, Melanie; Salloway, Stephen P.; Santacruz, Anna; Schneider, Lon S.; Wang, Guoqiao; Xiong, Chengjie

2016-01-01

INTRODUCTION The Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU) trial is an adaptive platform trial testing multiple drugs to slow or prevent the progression of Alzheimer’s disease in autosomal dominant Alzheimer’s disease (ADAD) families. With completion of enrollment of the first two drug arms, the DIAN-TU now plans to add new drugs to the platform, designated as the Next Generation Prevention Trial (NexGen). METHODS In collaboration with ADAD families, philanthropic organizations, academic leaders, the DIAN-TU Pharma Consortium, the NIH, and regulatory colleagues, the DIAN-TU developed innovative clinical study designs for the DIAN-TU NexGen trial. RESULTS Our expanded trials toolbox consists of a Disease Progression Model for ADAD, primary endpoint DIAN-TU cognitive performance composite, biomarker development, self-administered cognitive assessments, adaptive dose adjustments, and blinded data collection through the last participant completion. CONCLUSION These steps represent elements to improve efficacy of the adaptive platform trial and a continued effort to optimize prevention and treatment trials in ADAD. PMID:27583651

Automatic activation of word phonology from print in deep dyslexia.

PubMed

Katz, R B; Lanzoni, S M

1992-11-01

The performance of deep dyslexics in oral reading and other tasks suggests that they are poor at activating the phonology of words and non-words from printed stimuli. As the tasks ordinarily used to test deep dyslexics require controlled processing, it is possible that the phonology of printed words can be better activated on an automatic basis. This study investigated this possibility by testing a deep dyslexic patient on a lexical decision task with pairs of stimuli presented simultaneously. In Experiment 1, which used content words as stimuli, the deep dyslexic, like normal subjects, showed faster reaction times on trials with rhyming, similarly spelled stimuli (e.g. bribe-tribe) than on control trials (consisting of non-rhyming, dissimilarly spelled words), but slower reaction times on trials with non-rhyming, similarly spelled stimuli (e.g. couch-touch). When the experiment was repeated using function words as stimuli, the patient no longer showed a phonological effect. Therefore, the phonological activation of printed content words by deep dyslexics may be better than would be expected on the basis of their oral reading performance.

SMART: self-management of anticoagulation, a randomised trial [ISRCTN19313375].

PubMed

McCahon, Deborah; Fitzmaurice, David A; Murray, Ellen T; Fuller, Christopher J; Hobbs, Richard F D; Allan, Teresa F; Raftery, James P

2003-09-18

Oral anticoagulation monitoring has traditionally taken place in secondary care because of the need for a laboratory blood test, the international normalised ratio (INR). The development of reliable near patient testing (NPT) systems for INR estimation has facilitated devolution of testing to primary care. Patient self-management is a logical progression from the primary care model. This study will be the first to randomise non-selected patients in primary care, to either self-management or standard care. The study was a multi-centred randomised controlled trial with patients from 49 general practices recruited. Those suitable for inclusion were aged 18 or over, with a long term indication for oral anticoagulation, who had taken warfarin for at least six months. Patients randomised to the intervention arm attended at least two training sessions which were practice-based, 1 week apart. Each patient was assessed on their capability to undertake self management. If considered capable, they were given a near patient INR testing monitor, test strips and quality control material for home testing. Patients managed their own anticoagulation for a period of 12 months and performed their INR test every 2 weeks. Control patients continued with their pre-study care either attending hospital or practice based anticoagulant clinics. The methodology used in this trial will overcome concerns from previous trials of selection bias and relevance to the UK health service. The study will give a clearer understanding of the benefits of self-management in terms of clinical and cost effectiveness and patient preference.

Resting sympatho-vagal balance is related to 10 km running performance in master endurance athletes.

PubMed

Cataldo, Angelo; Bianco, Antonino; Paoli, Antonio; Cerasola, Dario; Alagna, Saverio; Messina, Giuseppe; Zangla, Daniele; Traina, Marcello

2018-01-12

Relationships between heart rate recovery after exercise (HRR, baseline heart rate variability measures (HRV), and time to perform a 10Km running trial (t10Km) were evaluated in "master" athletes of endurance to assess whether the measured indexes may be useful for monitoring the training status of the athletes. Ten "master" athletes of endurance, aged 40-60 years, were recruited. After baseline measures of HRV, the athletes performed a graded maximal test on treadmill and HRR was measured at 1 and 2 minutes from recovery. Subsequently they performed a 10Km running trial and t10Km was related to HRV and HRR indexes. The time to perform a 10Km running trial was significantly correlated with baseline HRV indexes. No correlation was found between t10Km and HRR. Baseline HRV measures, but not HRR, were significantly correlated with the time of performance on 10km running in "master" athletes. The enhanced parasympathetic function at rest appears to be a condition to a better performance on 10km running. HRV can be simple and useful measurements for monitoring the training stratus of athletes and their physical condition in proximity of a competition.

Operationalizing hippocampal volume as an enrichment biomarker for amnestic MCI trials: effect of algorithm, test-retest variability and cut-point on trial cost, duration and sample size

PubMed Central

Yu, P.; Sun, J.; Wolz, R.; Stephenson, D.; Brewer, J.; Fox, N.C.; Cole, P.E.; Jack, C.R.; Hill, D.L.G.; Schwarz, A.J.

2014-01-01

Objective To evaluate the effect of computational algorithm, measurement variability and cut-point on hippocampal volume (HCV)-based patient selection for clinical trials in mild cognitive impairment (MCI). Methods We used normal control and amnestic MCI subjects from ADNI-1 as normative reference and screening cohorts. We evaluated the enrichment performance of four widely-used hippocampal segmentation algorithms (FreeSurfer, HMAPS, LEAP and NeuroQuant) in terms of two-year changes in MMSE, ADAS-Cog and CDR-SB. We modeled the effect of algorithm, test-retest variability and cut-point on sample size, screen fail rates and trial cost and duration. Results HCV-based patient selection yielded not only reduced sample sizes (by ~40–60%) but also lower trial costs (by ~30–40%) across a wide range of cut-points. Overall, the dependence on the cut-point value was similar for the three clinical instruments considered. Conclusion These results provide a guide to the choice of HCV cut-point for aMCI clinical trials, allowing an informed trade-off between statistical and practical considerations. PMID:24211008

A Bayesian adaptive design for biomarker trials with linked treatments.

PubMed

Wason, James M S; Abraham, Jean E; Baird, Richard D; Gournaris, Ioannis; Vallier, Anne-Laure; Brenton, James D; Earl, Helena M; Mander, Adrian P

2015-09-01

Response to treatments is highly heterogeneous in cancer. Increased availability of biomarkers and targeted treatments has led to the need for trial designs that efficiently test new treatments in biomarker-stratified patient subgroups. We propose a novel Bayesian adaptive randomisation (BAR) design for use in multi-arm phase II trials where biomarkers exist that are potentially predictive of a linked treatment's effect. The design is motivated in part by two phase II trials that are currently in development. The design starts by randomising patients to the control treatment or to experimental treatments that the biomarker profile suggests should be active. At interim analyses, data from treated patients are used to update the allocation probabilities. If the linked treatments are effective, the allocation remains high; if ineffective, the allocation changes over the course of the trial to unlinked treatments that are more effective. Our proposed design has high power to detect treatment effects if the pairings of treatment with biomarker are correct, but also performs well when alternative pairings are true. The design is consistently more powerful than parallel-groups stratified trials. This BAR design is a powerful approach to use when there are pairings of biomarkers with treatments available for testing simultaneously.

Towards a Theory of Learning for Naming Rehabilitation: Retrieval Practice and Spacing Effects

PubMed Central

Schwartz, Myrna F.; Rawson, Katherine A.; Traut, Hilary; Verkuilen, Jay

2016-01-01

Purpose The purpose of this article was to examine how different types of learning experiences affect naming impairment in aphasia. Methods In 4 people with aphasia with naming impairment, we compared the benefits of naming treatment that emphasized retrieval practice (practice retrieving target names from long-term memory) with errorless learning (repetition training, which preempts retrieval practice) according to different schedules of learning. The design was within subjects. Items were administered for multiple training trials for retrieval practice or repetition in a spaced schedule (an item's trials were separated by multiple unrelated trials) or massed schedule (1 trial intervened between an item's trials). In the spaced condition, we studied 3 magnitudes of spacing to evaluate the impact of effortful retrieval during training on the ultimate benefits conferred by retrieval practice naming treatment. The primary outcome was performance on a retention test of naming after 1 day, with a follow-up test after 1 week. Results Group analyses revealed that retrieval practice outperformed errorless learning, and spaced learning outperformed massed learning at retention test and at follow-up. Increases in spacing in the retrieval practice condition yielded more robust learning of retrieved information. Conclusion This study delineates the importance of retrieval practice and spacing for treating naming impairment in aphasia. PMID:27716858

The automaticity of face perception is influenced by familiarity.

PubMed

Yan, Xiaoqian; Young, Andrew W; Andrews, Timothy J

2017-10-01

In this study, we explore the automaticity of encoding for different facial characteristics and ask whether it is influenced by face familiarity. We used a matching task in which participants had to report whether the gender, identity, race, or expression of two briefly presented faces was the same or different. The task was made challenging by allowing nonrelevant dimensions to vary across trials. To test for automaticity, we compared performance on trials in which the task instruction was given at the beginning of the trial, with trials in which the task instruction was given at the end of the trial. As a strong criterion for automatic processing, we reasoned that if perception of a given characteristic (gender, race, identity, or emotion) is fully automatic, the timing of the instruction should not influence performance. We compared automaticity for the perception of familiar and unfamiliar faces. Performance with unfamiliar faces was higher for all tasks when the instruction was given at the beginning of the trial. However, we found a significant interaction between instruction and task with familiar faces. Accuracy of gender and identity judgments to familiar faces was the same regardless of whether the instruction was given before or after the trial, suggesting automatic processing of these properties. In contrast, there was an effect of instruction for judgments of expression and race to familiar faces. These results show that familiarity enhances the automatic processing of some types of facial information more than others.

Blood and Marrow Transplant Clinical Trials Network Report on the Development of Novel Endpoints and Selection of Promising Approaches for Graft-versus-Host Disease Prevention Trials.

PubMed

Pasquini, Marcelo C; Logan, Brent; Jones, Richard J; Alousi, Amin M; Appelbaum, Frederick R; Bolaños-Meade, Javier; Flowers, Mary E D; Giralt, Sergio; Horowitz, Mary M; Jacobsohn, David; Koreth, John; Levine, John E; Luznik, Leo; Maziarz, Richard; Mendizabal, Adam; Pavletic, Steven; Perales, Miguel-Angel; Porter, David; Reshef, Ran; Weisdorf, Daniel; Antin, Joseph H

2018-06-01

Graft-versus-host disease (GVHD) is a common complication after hematopoietic cell transplantation (HCT) and associated with significant morbidity and mortality. Preventing GVHD without chronic therapy or increasing relapse is a desired goal. Here we report a benchmark analysis to evaluate the performance of 6 GVHD prevention strategies tested at single institutions compared with a large multicenter outcomes database as a control. Each intervention was compared with the control for the incidence of acute and chronic GVHD and overall survival and against novel composite endpoints: acute and chronic GVHD, relapse-free survival (GRFS), and chronic GVHD, relapse-free survival (CRFS). Modeling GRFS and CRFS using the benchmark analysis further informed the design of 2 clinical trials testing GVHD prophylaxis interventions. This study demonstrates the potential benefit of using an outcomes database to select promising interventions for multicenter clinical trials and proposes novel composite endpoints for use in GVHD prevention trials. Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Randomised controlled trial of routine individual feedback to improve rationality and reduce numbers of test requests.

PubMed

Winkens, R A; Pop, P; Bugter-Maessen, A M; Grol, R P; Kester, A D; Beusmans, G H; Knottnerus, J A

1995-02-25

Feedback can be described as a way to provide information on doctors' performance to enable changes in future behaviour. Feedback is used with the aim of changing test-ordering behaviour. It can lead to reductions in test usage and cost savings. It is not sufficiently clear, however, whether feedback leads to more appropriate test use. Since 1985, the Diagnostic Coordinating Center Maastricht has been giving feedback on diagnostic tests as a routine health care activity to all family doctors in its region. Both quantity and quality of requests are discussed. In a randomised, controlled trial over 2.5 years, discussion of tests not included previously was added to the existing routine feedback. One group of family doctors (n = 39) received feedback on test-group A (electrocardiography, endoscopy, cervical smears, and allergy tests), the other (n = 40) on test-group B (radiographic and ultrasonographic tests). Thus, each group of doctors acted as a control group for the other. Changes in volume and rationality of requests were analysed. The number of requests decreased during the trial (p = 0.036). Request numbers decreased particularly for test-group A (p = 0.04). The proportion of requests that were non-rational decreased more in the intervention than in the control groups (p = 0.009). Rationality improved predominantly for test-group B (p = 0.043). Thus, routine feedback can change the quantity and quality of requests.

Robust multivariate nonparametric tests for detection of two-sample location shift in clinical trials

PubMed Central

Jiang, Xuejun; Guo, Xu; Zhang, Ning; Wang, Bo

2018-01-01

This article presents and investigates performance of a series of robust multivariate nonparametric tests for detection of location shift between two multivariate samples in randomized controlled trials. The tests are built upon robust estimators of distribution locations (medians, Hodges-Lehmann estimators, and an extended U statistic) with both unscaled and scaled versions. The nonparametric tests are robust to outliers and do not assume that the two samples are drawn from multivariate normal distributions. Bootstrap and permutation approaches are introduced for determining the p-values of the proposed test statistics. Simulation studies are conducted and numerical results are reported to examine performance of the proposed statistical tests. The numerical results demonstrate that the robust multivariate nonparametric tests constructed from the Hodges-Lehmann estimators are more efficient than those based on medians and the extended U statistic. The permutation approach can provide a more stringent control of Type I error and is generally more powerful than the bootstrap procedure. The proposed robust nonparametric tests are applied to detect multivariate distributional difference between the intervention and control groups in the Thai Healthy Choices study and examine the intervention effect of a four-session motivational interviewing-based intervention developed in the study to reduce risk behaviors among youth living with HIV. PMID:29672555

The effect of lithium chloride on one-trial passive avoidance learning in rats.

PubMed Central

Johnson, F N

1976-01-01

1 Expression of a one-trial passive avoidance learning response in rats was examined following injections of lithium chloride or sodium chloride before and after initial training and before the first day of testing. Five tests were given at daily intervals, 24 h after training being the time of the first test. 2. Lithium given before the first day of testing impaired response expression on the first and all subsequent days of testing; the rate of extinction was unaffected. 3. Given both before and immediately after initial training, lithium impaired response expression on the first day of testing but slowed down the subsequent rate of extinction, leading eventually to improved performance on the fifth day, as compared with placebo-treated control subjects. 4. The results are interpreted in the light of the hypothesis that lithium impaired the central processing of sensory information. PMID:1252666

Regenerative Life Support Systems (RLSS) test bed performance - Characterization of plant performance in a controlled atmosphere

NASA Technical Reports Server (NTRS)

Edeen, Marybeth; Henninger, Donald

1991-01-01

By growing higher plants for food, lunar and Martian manned habitats will not only reduce resupply requirements but obtain CO2 removal and both oxygen-production and water-reclamation requirements. Plants have been grown in the RLSS at NASA-Johnson in order to quantitatively evaluate plant CO2 accumulation, O2 generation, evapotranspiration, trace-contaminant generation, and biomass productivity. Attention is presently given to test conditions and anomalies in these RLSS trials; areas where performance must be improved have been identified.

A best practice fall prevention exercise program to improve balance, strength / power, and psychosocial health in older adults: study protocol for a randomized controlled trial

PubMed Central

2013-01-01

Background With increasing age neuromuscular deficits (e.g., sarcopenia) may result in impaired physical performance and an increased risk for falls. Prominent intrinsic fall-risk factors are age-related decreases in balance and strength / power performance as well as cognitive decline. Additional studies are needed to develop specifically tailored exercise programs for older adults that can easily be implemented into clinical practice. Thus, the objective of the present trial is to assess the effects of a fall prevention program that was developed by an interdisciplinary expert panel on measures of balance, strength / power, body composition, cognition, psychosocial well-being, and falls self-efficacy in healthy older adults. Additionally, the time-related effects of detraining are tested. Methods/Design Healthy old people (n = 54) between the age of 65 to 80 years will participate in this trial. The testing protocol comprises tests for the assessment of static / dynamic steady-state balance (i.e., Sharpened Romberg Test, instrumented gait analysis), proactive balance (i.e., Functional Reach Test; Timed Up and Go Test), reactive balance (i.e., perturbation test during bipedal stance; Push and Release Test), strength (i.e., hand grip strength test; Chair Stand Test), and power (i.e., Stair Climb Power Test; countermovement jump). Further, body composition will be analysed using a bioelectrical impedance analysis system. In addition, questionnaires for the assessment of psychosocial (i.e., World Health Organisation Quality of Life Assessment-Bref), cognitive (i.e., Mini Mental State Examination), and fall risk determinants (i.e., Fall Efficacy Scale – International) will be included in the study protocol. Participants will be randomized into two intervention groups or the control / waiting group. After baseline measures, participants in the intervention groups will conduct a 12-week balance and strength / power exercise intervention 3 times per week, with each training session lasting 30 min. (actual training time). One intervention group will complete an extensive supervised training program, while the other intervention group will complete a short version ('3 times 3’) that is home-based and controlled by weekly phone calls. Post-tests will be conducted right after the intervention period. Additionally, detraining effects will be measured 12 weeks after program cessation. The control group / waiting group will not participate in any specific intervention during the experimental period, but will receive the extensive supervised program after the experimental period. Discussion It is expected that particularly the supervised combination of balance and strength / power training will improve performance in variables of balance, strength / power, body composition, cognitive function, psychosocial well-being, and falls self-efficacy of older adults. In addition, information regarding fall risk assessment, dose–response-relations, detraining effects, and supervision of training will be provided. Further, training-induced health-relevant changes, such as improved performance in activities of daily living, cognitive function, and quality of life, as well as a reduced risk for falls may help to lower costs in the health care system. Finally, practitioners, therapists, and instructors will be provided with a scientifically evaluated feasible, safe, and easy-to-administer exercise program for fall prevention. Trial registration ClinicalTrials.gov Identifier: NCT01906034 PMID:24106864

An open trial assessment of "The Number Race", an adaptive computer game for remediation of dyscalculia

PubMed Central

Wilson, Anna J; Revkin, Susannah K; Cohen, David; Cohen, Laurent; Dehaene, Stanislas

2006-01-01

Background In a companion article [1], we described the development and evaluation of software designed to remediate dyscalculia. This software is based on the hypothesis that dyscalculia is due to a "core deficit" in number sense or in its access via symbolic information. Here we review the evidence for this hypothesis, and present results from an initial open-trial test of the software in a sample of nine 7–9 year old children with mathematical difficulties. Methods Children completed adaptive training on numerical comparison for half an hour a day, four days a week over a period of five-weeks. They were tested before and after intervention on their performance in core numerical tasks: counting, transcoding, base-10 comprehension, enumeration, addition, subtraction, and symbolic and non-symbolic numerical comparison. Results Children showed specific increases in performance on core number sense tasks. Speed of subitizing and numerical comparison increased by several hundred msec. Subtraction accuracy increased by an average of 23%. Performance on addition and base-10 comprehension tasks did not improve over the period of the study. Conclusion Initial open-trial testing showed promising results, and suggested that the software was successful in increasing number sense over the short period of the study. However these results need to be followed up with larger, controlled studies. The issues of transfer to higher-level tasks, and of the best developmental time window for intervention also need to be addressed. PMID:16734906

Temporal unfolding of declining episodic memory on the Free and Cued Selective Reminding Test in the predementia phase of Alzheimer's disease: Implications for clinical trials.

PubMed

Grober, Ellen; Veroff, Amy E; Lipton, Richard B

2018-01-01

Free and Cued Selective Reminding Test (FCSRT) performance identifies patients with preclinical disease at elevated risk for developing Alzheimer's dementia, predicting diagnosis better than other memory tests. Based on literature mapping FCSRT performance to clinical outcomes and biological markers, and on longitudinal preclinical data from the Baltimore Longitudinal Study of Aging, we developed the Stages of Objective Memory Impairment (SOMI) model. Five sequential stages of episodic memory decline are defined by Free Recall (FR) and Total Recall (TR) score ranges and years prior to dementia diagnosis. We sought to replicate the SOMI model using longitudinal assessments of 142 Einstein Aging Study participants who developed AD over 10 years. Time to diagnosis was at least seven years if FR was intact, at least four years if TR was intact, and two years if TR was impaired, consistent with SOMI model predictions. The SOMI identified incipient dementia with excellent sensitivity and specificity. The SOMI model provides an efficient approach for clinical trial cognitive screening in advance of more costly biomarker studies and ultimately in clinical practice, and provides a vocabulary for understanding AD biomarker patterns and for re-analysis of existing clinical trial data.

Analysis of Factors Affecting Successful Clinical Trial Enrollment in the Context of Three Prospective, Randomized, Controlled Trials

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

Logan, Jennifer K.; Tang, Chad; Liao, Zhongxing

Purpose: Challenges can arise when attempting to maximize patient enrollment in clinical trials. There have been limited studies focusing on the barriers to enrollment and the efficacy of alternative study design to improve accrual. We analyzed barriers to clinical trial enrollment, particularly the influence of timing, in context of three prospective, randomized oncology trials where one arm was considered more aggressive than the other. Methods and Materials: From June 2011 to March 2015, patients who were enrolled on 3 prospective institutional protocols (an oligometastatic non-small cell lung cancer [NSCLC] trial and 2 proton vs intensity modulated radiation therapy trials inmore » NSCLC and esophageal cancer) were screened for protocol eligibility. Eligible candidates were approached about trial participation, and patient characteristics (age, sex, T/N categorization) were recorded along with details surrounding trial presentation (appointment number). Fisher's exact test, Student's t tests, and multivariate analysis were performed to assess differences between enrolled and refusal patients. Results: A total of 309 eligible patients were approached about trial enrollment. The enrollment success rate during this time span was 52% (n=160 patients). Enrolled patients were more likely to be presented trial information at an earlier appointment (oligometastatic protocol: 5 vs 3 appointments [P<.001]; NSCLC protocol: 4 vs 3 appointments [P=.0018]; esophageal protocol: 3 vs 2 appointments [P=.0086]). No other factors or patient characteristics significantly affected enrollment success rate. Conclusion: Improvement in enrollment rates for randomized control trials is possible, even in difficult accrual settings. Earlier presentation of trial information to patients is the most influential factor for success and may help overcome accrual barriers without compromising trial design.« less

Preclinical Alzheimer's disease and longitudinal driving decline.

PubMed

Roe, Catherine M; Babulal, Ganesh M; Head, Denise M; Stout, Sarah H; Vernon, Elizabeth K; Ghoshal, Nupur; Garland, Brad; Barco, Peggy P; Williams, Monique M; Johnson, Ann; Fierberg, Rebecca; Fague, M Scot; Xiong, Chengjie; Mormino, Elizabeth; Grant, Elizabeth A; Holtzman, David M; Benzinger, Tammie L S; Fagan, Anne M; Ott, Brian R; Carr, David B; Morris, John C

2017-01-01

Links between preclinical AD and driving difficulty onset would support the use of driving performance as an outcome in primary and secondary prevention trials among older adults (OAs). We examined whether AD biomarkers predicted the onset of driving difficulties among OAs. 104 OAs (65+ years) with normal cognition took part in biomarker measurements, a road test, clinical and psychometric batteries and self-reported their driving habits. Higher values of CSF tau/Aβ 42 and ptau 181 /Aβ 42 ratios, but not uptake on PIB amyloid imaging (p=.12), predicted time to a rating of Marginal or Fail on the driving test using Cox proportional hazards models. Hazards ratios (95% confidence interval) were 5.75 (1.70-19.53), p=.005 for CSF tau/Aβ 42 ; 6.19 (1.75-21.88) and p=.005 for CSF ptau 181 /Aβ 42 . Preclinical AD predicted time to receiving a Marginal or Fail rating on an on-road driving test. Driving performance shows promise as a functional outcome in AD prevention trials.

Using Wearable Sensors and Machine Learning Models to Separate Functional Upper Extremity Use From Walking-Associated Arm Movements.

PubMed

McLeod, Adam; Bochniewicz, Elaine M; Lum, Peter S; Holley, Rahsaan J; Emmer, Geoff; Dromerick, Alexander W

2016-02-01

To improve measurement of upper extremity (UE) use in the community by evaluating the feasibility of using body-worn sensor data and machine learning models to distinguish productive prehensile and bimanual UE activity use from extraneous movements associated with walking. Comparison of machine learning classification models with criterion standard of manually scored videos of performance in UE prosthesis users. Rehabilitation hospital training apartment. Convenience sample of UE prosthesis users (n=5) and controls (n=13) similar in age and hand dominance (N=18). Participants were filmed executing a series of functional activities; a trained observer annotated each frame to indicate either UE movement directed at functional activity or walking. Synchronized data from an inertial sensor attached to the dominant wrist were similarly classified as indicating either a functional use or walking. These data were used to train 3 classification models to predict the functional versus walking state given the associated sensor information. Models were trained over 4 trials: on UE amputees and controls and both within subject and across subject. Model performance was also examined with and without preprocessing (centering) in the across-subject trials. Percent correct classification. With the exception of the amputee/across-subject trial, at least 1 model classified >95% of test data correctly for all trial types. The top performer in the amputee/across-subject trial classified 85% of test examples correctly. We have demonstrated that computationally lightweight classification models can use inertial data collected from wrist-worn sensors to reliably distinguish prosthetic UE movements during functional use from walking-associated movement. This approach has promise in objectively measuring real-world UE use of prosthetic limbs and may be helpful in clinical trials and in measuring response to treatment of other UE pathologies. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Ecologically Valid Carbohydrate Intake during Soccer-Specific Exercise Does Not Affect Running Performance in a Fed State

PubMed Central

Funnell, Mark P.; Dykes, Nick R.; Owen, Elliot J.; Mears, Stephen A.; Rollo, Ian; James, Lewis J.

2017-01-01

This study assessed the effect of carbohydrate intake on self-selected soccer-specific running performance. Sixteen male soccer players (age 23 ± 4 years; body mass 76.9 ± 7.2 kg; predicted VO2max = 54.2 ± 2.9 mL∙kg−1∙min−1; soccer experience 13 ± 4 years) completed a progressive multistage fitness test, familiarisation trial and two experimental trials, involving a modified version of the Loughborough Intermittent Shuttle Test (LIST) to simulate a soccer match in a fed state. Subjects completed six 15 min blocks (two halves of 45 min) of intermittent shuttle running, with a 15-min half-time. Blocks 3 and 6, allowed self-selection of running speeds and sprint times, were assessed throughout. Subjects consumed 250 mL of either a 12% carbohydrate solution (CHO) or a non-caloric taste matched placebo (PLA) before and at half-time of the LIST. Sprint times were not different between trials (CHO 2.71 ± 0.15 s, PLA 2.70 ± 0.14 s; p = 0.202). Total distance covered in self-selected blocks (block 3: CHO 2.07 ± 0.06 km; PLA 2.09 ± 0.08 km; block 6: CHO 2.04 ± 0.09 km; PLA 2.06 ± 0.08 km; p = 0.122) was not different between trials. There was no difference between trials for distance covered (p ≥ 0.297) or mean speed (p ≥ 0.172) for jogging or cruising. Blood glucose concentration was greater (p < 0.001) at the end of half-time during the CHO trial. In conclusion, consumption of 250 mL of 12% CHO solution before and at half-time of a simulated soccer match does not affect self-selected running or sprint performance in a fed state. PMID:28067762

Ecologically Valid Carbohydrate Intake during Soccer-Specific Exercise Does Not Affect Running Performance in a Fed State.

PubMed

Funnell, Mark P; Dykes, Nick R; Owen, Elliot J; Mears, Stephen A; Rollo, Ian; James, Lewis J

2017-01-05

This study assessed the effect of carbohydrate intake on self-selected soccer-specific running performance. Sixteen male soccer players (age 23 ± 4 years; body mass 76.9 ± 7.2 kg; predicted VO 2max = 54.2 ± 2.9 mL∙kg -1 ∙min -1 ; soccer experience 13 ± 4 years) completed a progressive multistage fitness test, familiarisation trial and two experimental trials, involving a modified version of the Loughborough Intermittent Shuttle Test (LIST) to simulate a soccer match in a fed state. Subjects completed six 15 min blocks (two halves of 45 min) of intermittent shuttle running, with a 15-min half-time. Blocks 3 and 6, allowed self-selection of running speeds and sprint times, were assessed throughout. Subjects consumed 250 mL of either a 12% carbohydrate solution (CHO) or a non-caloric taste matched placebo (PLA) before and at half-time of the LIST. Sprint times were not different between trials (CHO 2.71 ± 0.15 s, PLA 2.70 ± 0.14 s; p = 0.202). Total distance covered in self-selected blocks (block 3: CHO 2.07 ± 0.06 km; PLA 2.09 ± 0.08 km; block 6: CHO 2.04 ± 0.09 km; PLA 2.06 ± 0.08 km; p = 0.122) was not different between trials. There was no difference between trials for distance covered ( p ≥ 0.297) or mean speed ( p ≥ 0.172) for jogging or cruising. Blood glucose concentration was greater ( p < 0.001) at the end of half-time during the CHO trial. In conclusion, consumption of 250 mL of 12% CHO solution before and at half-time of a simulated soccer match does not affect self-selected running or sprint performance in a fed state.

The Influence of Plantar Short Foot Muscle Exercises on Foot Posture and Fundamental Movement Patterns in Long-Distance Runners, a Non-Randomized, Non-Blinded Clinical Trial.

PubMed

Sulowska, Iwona; Oleksy, Łukasz; Mika, Anna; Bylina, Dorota; Sołtan, Jarosław

2016-01-01

The objective of this study was to evaluate the influence of two kinds of plantar short foot muscles exercise on foot posture and fundamental movement patterns in long-distance runners. A parallel group non-blinded trial with 6-week follow-up. Twenty five long-distance runners aged 22-35 years. They were divided into two groups. In group 1 (n = 13) subjects performed the exercise "Vele's Forward Lean" and "Reverse Tandem Gait" and in Group 2 (n = 12) the "Short Foot Exercise." The runners performed the exercises daily for 6 weeks. The Foot Posture Index (FPI-6) and The Functional Movement Screen (FMS) tests were performed twice: at baseline and after 6 weeks of the exercise. A significant improvement was observed in FPI -6 (talar head palpation in Group 1, and inversion/eversion of the calcaneus in Group 2). Also in Group 1 a significant improvement was noted in FMS tests: deep squat, active straight leg raise and in total score. Short foot muscles strengthening exercises have beneficial effect on functional movement patterns and on foot posture, therefore they should be included as a part of daily training program of runners. Australian New Zealand Clinical Trials Registry ACTRN12615001200572.

Associative Recognition Memory Awareness Improved by Theta-Burst Stimulation of Frontopolar Cortex

PubMed Central

Ryals, Anthony J.; Rogers, Lynn M.; Gross, Evan Z.; Polnaszek, Kelly L.; Voss, Joel L.

2016-01-01

Neuroimaging and lesion studies have implicated specific prefrontal cortex locations in subjective memory awareness. Based on this evidence, a rostrocaudal organization has been proposed whereby increasingly anterior prefrontal regions are increasingly involved in memory awareness. We used theta-burst transcranial magnetic stimulation (TBS) to temporarily modulate dorsolateral versus frontopolar prefrontal cortex to test for distinct causal roles in memory awareness. In three sessions, participants received TBS bilaterally to frontopolar cortex, dorsolateral prefrontal cortex, or a control location prior to performing an associative-recognition task involving judgments of memory awareness. Objective memory performance (i.e., accuracy) did not differ based on stimulation location. In contrast, frontopolar stimulation significantly influenced several measures of memory awareness. During study, judgments of learning were more accurate such that lower ratings were given to items that were subsequently forgotten selectively following frontopolar TBS. Confidence ratings during test were also higher for correct trials following frontopolar TBS. Finally, trial-by-trial correspondence between overt performance and subjective awareness during study demonstrated a linear increase across control, dorsolateral, and frontopolar TBS locations, supporting a rostrocaudal hierarchy of prefrontal contributions to memory awareness. These findings indicate that frontopolar cortex contributes causally to memory awareness, which was improved selectively by anatomically targeted TBS. PMID:25577574

Tramadol effects on physical performance and sustained attention during a 20-min indoor cycling time-trial: A randomised controlled trial.

PubMed

Holgado, Darías; Zandonai, Thomas; Zabala, Mikel; Hopker, James; Perakakis, Pandelis; Luque-Casado, Antonio; Ciria, Luis; Guerra-Hernandez, Eduardo; Sanabria, Daniel

2018-07-01

To investigate the effect of tramadol on performance during a 20-min cycling time-trial (Experiment 1), and to test whether sustained attention would be impaired during cycling after tramadol intake (Experiment 2). Randomized, double-blind, placebo controlled trial. In Experiment 1, participants completed a cycling time-trial, 120-min after they ingested either tramadol or placebo. In Experiment 2, participants performed a visual oddball task during the time-trial. Electroencephalography measures (EEG) were recorded throughout the session. In Experiment 1, average time-trial power output was higher in the tramadol vs. placebo condition (tramadol: 220W vs. placebo: 209W; p<0.01). In Experiment 2, no differences between conditions were observed in the average power output (tramadol: 234W vs. placebo: 230W; p>0.05). No behavioural differences were found between conditions in the oddball task. Crucially, the time frequency analysis in Experiment 2 revealed an overall lower target-locked power in the beta-band (p<0.01), and higher alpha suppression (p<0.01) in the tramadol vs. placebo condition. At baseline, EEG power spectrum was higher under tramadol than under placebo in Experiment 1 while the reverse was true for Experiment 2. Tramadol improved cycling power output in Experiment 1, but not in Experiment 2, which may be due to the simultaneous performance of a cognitive task. Interestingly enough, the EEG data in Experiment 2 pointed to an impact of tramadol on stimulus processing related to sustained attention. EudraCT number: 2015-005056-96. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Protocol for a randomised controlled trial of fetal scalp blood lactate measurement to reduce caesarean sections during labour: the Flamingo trial [ACTRN12611000172909].

PubMed

East, Christine E; Kane, Stefan C; Davey, Mary-Ann; Kamlin, C Omar; Brennecke, Shaun P

2015-11-03

The rate of caesarean sections around the world is rising each year, reaching epidemic proportions. Although many caesarean sections are performed for concerns about fetal welfare on the basis of abnormal cardiotocography, the majority of babies are shown to be well at birth, meaning that the operation, with its inherent short and long term risks, could have been avoided without compromising the baby's health. Previously, fetal scalp blood sampling for pH estimation was performed in the context of an abnormal cardiotocograph, to improve the identification of babies in need of expedited delivery. This test has largely been replaced by lactate measurement, although its validity is yet to be established through a randomised controlled trial. This study aims to test the hypothesis that the performance of fetal scalp blood lactate measurement for women in labour with an abnormal cardiotocograph will reduce the rate of birth by caesarean section from 38 % to 25 % (a 35 % relative reduction). Prospective unblinded randomised controlled trial conducted at a single tertiary perinatal centre. Women labouring with a singleton fetus in cephalic presentation at 37 or more weeks' gestation with ruptured membranes and with an abnormal cardiotocograph will be eligible. Participants will be randomised to one of two groups: fetal monitoring by cardiotocography alone, or cardiotocography augmented by fetal scalp blood lactate analysis. Decisions regarding the timing and mode of delivery will be made by the treating team, in accordance with hospital protocols. The primary study endpoint is caesarean section with secondary outcomes collected from maternal, fetal and neonatal clinical course and morbidities. A cost effectiveness analysis will also be performed. A sample size of 600 will provide 90 % power to detect the hypothesised difference in the proportion of women who give birth by caesarean section. This world-first trial is adequately powered to determine the impact of fetal scalp blood lactate measurement on rates of caesarean section. Preventing unnecessary caesarean sections will reduce the health and financial burdens associated with this operation, both in the index and any future pregnancies. Australian New Zealand Clinical Trials Registry ACTRN12611000172909.

Micronutrient-Fortified Milk and Academic Performance among Chinese Middle School Students: A Cluster-Randomized Controlled Trial

PubMed Central

Wang, Xiaoqin; Hui, Zhaozhao; Dai, Xiaoling; Terry, Paul D.; Zhang, Yue; Ma, Mei; Wang, Mingxu; Deng, Fu; Gu, Wei; Lei, Shuangyan; Li, Ling; Ma, Mingyue; Zhang, Bin

2017-01-01

Many children suffer from nutritional deficiencies that may negatively affect their academic performance. This cluster-randomized controlled trial aimed to test the effects of micronutrient-fortified milk in Chinese students. Participants received either micronutrient-fortified (n = 177) or unfortified (n = 183) milk for six months. Academic performance, motivation, and learning strategies were estimated by end-of-term tests and the Motivated Strategies for Learning Questionnaire. Blood samples were analyzed for micronutrients. In total, 296 students (82.2%) completed this study. Compared with the control group, students in the intervention group reported higher scores in several academic subjects (p < 0.05), including languages, mathematics, ethics, and physical performance at the end of follow-up. Students in the intervention group showed greater self-efficacy and use of cognitive strategies in learning, and reported less test anxiety (p < 0.001). Moreover, vitamin B2 deficiency (odds ratio (OR) = 0.18, 95% confidence interval (CI): 0.11~0.30) and iron deficiency (OR = 0.34, 95% CI: 0.14~0.81) were less likely in the students of the intervention group, whereas vitamin D, vitamin B12, and selenium deficiencies were not significantly different. “Cognitive strategy” had a partial mediating effect on the test scores of English (95% CI: 1.26~3.79) and Chinese (95% CI: 0.53~2.21). Our findings suggest that micronutrient-fortified milk may improve students’ academic performance, motivation, and learning strategies. PMID:28257107

Motivational deficits and cognitive test performance in schizophrenia.

PubMed

Fervaha, Gagan; Zakzanis, Konstantine K; Foussias, George; Graff-Guerrero, Ariel; Agid, Ofer; Remington, Gary

2014-09-01

Motivational and cognitive deficits are core features of schizophrenia, both closely linked with functional outcomes. Although poor effort and decreased motivation are known to affect performance on cognitive tests, the extent of this relationship is unclear in patients with schizophrenia. To evaluate the association between intrinsic motivation and cognitive test performance in patients with schizophrenia. Cross-sectional and 6-month prospective follow-up study performed at 57 sites in the United States, including academic and community medical treatment centers, participating in the Clinical Antipsychotic Trials of Intervention Effectiveness study. The primary sample included 431 stable patients with a DSM-IV diagnosis of schizophrenia currently receiving a stable medication regimen. Cognitive performance and intrinsic motivation were evaluated using a comprehensive neuropsychological test battery and a derived measure from the Heinrichs-Carpenter Quality of Life Scale, respectively. Symptom severity and functional status were also assessed. The primary outcome variable was global neurocognition. Individual domains of cognition were also evaluated for their association with motivation. Level of intrinsic motivation was significantly and positively correlated with global cognitive test performance, a relationship that held for each domain of cognition evaluated (correlation range, 0.20-0.34; P < .001). This association was found to be reliable after statistically accounting for positive, negative, depressive, and overall symptom severity (P < .05) and after accounting for community functioning (P < .001). The relationship between motivation and cognitive performance also remained significant after controlling for antipsychotic dose (P < .05). Prospective increase in motivation during the 6-month follow-up was also found to be significantly related to improvement in global cognitive performance (P < .05). The present findings provide strong support for a robust and reliable relationship between motivation and cognitive performance and suggest that test performance is not purely a measure of ability. Future studies assessing cognition in patients with schizophrenia should consider potential moderating variables such as effort and motivation. Implications for the assessment and interpretation of cognitive impairment based on neuropsychological test measures in schizophrenia are discussed, especially in the case of clinical trials for cognition-enhancing treatments. clinicaltrials.gov Identifier: NCT00014001.

Short-term creatine supplementation has no impact on upper-body anaerobic power in trained wrestlers.

PubMed

Aedma, Martin; Timpmann, Saima; Lätt, Evelin; Ööpik, Vahur

2015-01-01

Creatine (CR) is considered an effective nutritional supplement having ergogenic effects, which appears more pronounced in upper-body compared to lower-body exercise. Nevertheless, results regarding the impact of CR loading on repeated high-intensity arm-cranking exercise are scarce and in some cases conflicting. Interestingly, few of the conducted studies have structured their research designs to mimic real world sporting events. Therefore, our purpose was to address the hypothesis that CR ingestion would increase anaerobic power output in consecutive upper-body intermittent sprint performance (UBISP) tests designed to simulate wrestling matches on a competition-day. In a double-blind, placebo-controlled, parallel-group study, 20 trained wrestlers were assigned to either placebo or CR supplemented group (0.3 g ∙ kg(-1) of body mass per day). Four 6-min UBISP tests interspersed with 30-min recovery periods were performed before (trial 1) and after 5 days (trial 2) of supplementation. Each test consisted of six 15-s periods of arm-cranking at maximal executable cadence against resistance of 0.04 kg ∙ kg(-1) body mass interspersed with 40-s unloaded easy cranking periods and 5-s acceleration intervals (T1-T4). Mean power (MP), peak power (PP), fatigue index and heart rate parameters were measured during UBISP tests. Also, body weight and hydration status were assessed. Principle measures were statistical analysed with mixed-model ANOVAs. Mean individual CR consumption in the CR group was 24.8 ± 2.5 g ∙ d(-1). No significant (P > 0.05) differences occurred in body mass or hydration status indices between the groups or across trials. MP, PP and fatigue index responses were unaffected by supplementation; although, a significant reduction in MP and PP did occurred from T1 to T4 in both trial 1 and 2 (P < 0.001). Overall heart rate responses in the tests tended to be higher in the CR than PLC group (P < 0.05); but, trends in responses in trials and tests were comparable (P > 0.05). These results suggest that 5-day CR supplementation has no impact on upper-body muscle anaerobic power output in consecutive UBISP anaerobic tests mimicking wrestling matches on a competition day.

PILOT TESTING: PRETREATMENT OPTIONS TO ALLOW RE-USE OF FRAC FLOWBACK AND PRODUCED BRINE FOR GAS SHALE RESOURCE DEVELOPMENT

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

Burnett, David

2012-12-31

The goal of the A&M DOE NETL Project No. DE-FE0000847 was to develop a mobile, multifunctional water treatment capability designed specifically for “pre-treatment” of field waste brine. The project consisted of constructing s mobile “field laboratory” incorporating new technology for treating high salinity produced water and using the lab to conduct a side-by-side comparison between this new technology and that already existing in field operations. A series of four field trials were performed utilizing the mobile unit to demonstrate the effectiveness of different technology suitable for use with high salinity flow back brines and produced water. The design of themore » mobile unit was based on previous and current work at the Texas A&M Separation Sciences Pilot Plant. The several treatment techniques which have been found to be successful in both pilot plant and field tests had been tested to incorporate into a single multifunctional process train. Eight different components were evaluated during the trials, two types of oil and grease removal, one BTEX removal step, three micro-filters, and two different nanofilters. The performance of each technique was measured by its separation efficiency, power consumption, and ability to withstand fouling. The field trials were a success. Four different field brines were evaluated in the first trial in New York. Over 16,000 gallons of brine were processed. Using a power cost of $.10 per kWh, media pretreatment power use averaged $0.004 per barrel, solids removal $.04 per barrel and brine “softening” $.84 per barrel. Total power cost was approximately $1.00 per barrel of fluid treated. In Pennsylvania, brines collected from frac ponds were tested in two additional trials. Each of the brines was converted to an oil-free, solids-free brine with no biological activity. Brines were stable over time and would be good candidates for use as a make-up fluid in a subsequent fracturing fluid design. Reports on all of the field trials and subcontractor research have been summarized in this Final Report. Individual field trial reports and research reports are contained in the companion volume titled “Appendices”« less

Aromatherapy for treatment of hypertension: a systematic review.

PubMed

Hur, Myung-Haeng; Lee, Myeong Soo; Kim, Chan; Ernst, Edzard

2012-02-01

The objective of this review is to systematically review the evidence for the effectiveness of aromatherapy in the treatment of high blood pressure. Twelve databases were searched from their inception through December 2009. Controlled trials testing aromatherapy in patients with hypertension of any origin that assessed blood pressure were considered. The selection of studies, data extraction and validations were performed independently by two reviewers. One randomized clinical trial (RCT) and four non-randomized controlled clinical trials (CCTs) met our inclusion criteria. The one RCT included tested the effects of aromatherapy as compared with placebo and showed significant reduction of systolic blood pressure and diastolic blood pressure. All of the four CCTs showed favourable effects of aromatherapy. However, all of the CCTs also had a high risk of bias. The existing trial evidence does not show convincingly that aromatherapy is effective for hypertension. Future studies should be of high quality with a particular emphasis on designing an adequate control intervention. © 2010 Blackwell Publishing Ltd.

Do children with reading delay benefit from the use of personal FM systems in the classroom?

PubMed

Purdy, Suzanne C; Smart, Jennifer L; Baily, Melissa; Sharma, Mridula

2009-12-01

FM systems have been used to compensate for poor signal-to-noise ratios in classrooms. This study evaluates benefits of a 6-week trial of personal FM systems used during the school day for children with reading delay aged 6-11 years, using a randomized control design. Teachers and children completed the LIFE-UK questionnaire. Test-retest reliability of the LIFE-UK children's version was confirmed in a separate group of 18 children from the same school. The 23 children in the FM group had significantly improved teacher ratings, and the children's ratings of classroom listening for difficult situations were significantly better after the trial. These changes did not occur for the 23 control-group children. Most children (92%) commented positively about the FM after the trial. It is likely that a longer FM trial or a specific reading intervention combined with FM will be required for the benefits of enhanced listening to affect performance on standardized reading tests.

The subtype-selective nicotinic acetylcholine receptor agonist SIB-1553A improves both attention and memory components of a spatial working memory task in chronic low dose 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated monkeys.

PubMed

Schneider, J S; Tinker, J P; Menzaghi, F; Lloyd, G K

2003-07-01

Monkeys that receive chronic low dose (CLD) 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration develop deficits in spatial delayed-response task performance. The present study examined the extent to which SIB-1553A [(+/-)-4-[[2-(1-methyl-2-pyrrolidinyl)ethyl]thio]phenol hydrochloride], a novel neuronal nicotinic acetylcholine receptor (nAChR) agonist with selectivity for beta4 subunit-containing nAChRs, could counteract this cognitive deficit produced by CLD MPTP exposure. Prior to MPTP treatment, monkeys displayed a delay-dependent decrement in performance on a variable delayed response task. CLD MPTP treatment caused a shift to a delay-independent pattern of responding on this task, such that short-delay trials were performed as poorly as long-delay trials. At lower doses (e.g., 0.025 mg/kg), SIB-1553A significantly improved performance on short-delay trials but only at 24 h after drug administration. At higher doses (e.g., 0.50 mg/kg), SIB-1553A significantly improved performance on both short- and long-delay trials at both 20 min and 24 h after drug administration. When tested 24 h after drug administration, monkeys performed long-delay trials with greater accuracy than they did under normal (pre-MPTP) conditions. These results suggest that at lower doses, SIB-1553A may be more effective in improving attentional deficits associated with CLD MPTP exposure, whereas at higher doses, SIB-1553A may effectively improve both attentional and memory performance.

Effect of a novel two-desk sit-to-stand workplace (ACTIVE OFFICE) on sitting time, performance and physiological parameters: protocol for a randomized control trial.

PubMed

Schwartz, Bernhard; Kapellusch, Jay M; Schrempf, Andreas; Probst, Kathrin; Haller, Michael; Baca, Arnold

2016-07-15

Prolonged sitting is ubiquitous in modern society and linked to several diseases. Height-adjustable desks are being used to decrease worksite based sitting time (ST). Single-desk sit-to-stand workplaces exhibit small ST reduction potential and short-term loss in performance. The aim of this paper is to report the study design and methodology of an ACTIVE OFFICE trial. The study was a 1-year three-arm, randomized controlled trial in 18 healthy Austrian office workers. Allocation was done via a regional health insurance, with data collection during Jan 2014 - March 2015. Participants were allocated to either an intervention or control group. Intervention group subjects were provided with traditional or two-desk sit-to-stand workstations in either the first or the second half of the study, while control subjects did not experience any changes during the whole study duration. Sitting time and physical activity (IPAQ-long), cognitive performance (text editing task, Stroop-test, d2R test of attention), workload perception (NASA-TLX) and physiological parameters (salivary cortisol, heartrate variability and body weight) were measured pre- and post-intervention (23 weeks after baseline) for intervention and control periods. Postural changes and sitting/standing time (software logger) were recorded at the workplace for the whole intervention period. This study evaluates the effects of a novel two-desk sit-to-stand workplace on sitting time, physical parameters and work performance of healthy office based workers. If the intervention proves effective, it has a great potential to be implemented in regular workplaces to reduce diseases related to prolonged sitting. ClinicalTrials.gov Identifier: NCT02825303 , July 2016 (retrospectively registered).

Mice plan decision strategies based on previously learned time intervals, locations, and probabilities

PubMed Central

Tosun, Tuğçe; Gür, Ezgi; Balcı, Fuat

2016-01-01

Animals can shape their timed behaviors based on experienced probabilistic relations in a nearly optimal fashion. On the other hand, it is not clear if they adopt these timed decisions by making computations based on previously learnt task parameters (time intervals, locations, and probabilities) or if they gradually develop their decisions based on trial and error. To address this question, we tested mice in the timed-switching task, which required them to anticipate when (after a short or long delay) and at which of the two delay locations a reward would be presented. The probability of short trials differed between test groups in two experiments. Critically, we first trained mice on relevant task parameters by signaling the active trial with a discriminative stimulus and delivered the corresponding reward after the associated delay without any response requirement (without inducing switching behavior). During the test phase, both options were presented simultaneously to characterize the emergence and temporal characteristics of the switching behavior. Mice exhibited timed-switching behavior starting from the first few test trials, and their performance remained stable throughout testing in the majority of the conditions. Furthermore, as the probability of the short trial increased, mice waited longer before switching from the short to long location (experiment 1). These behavioral adjustments were in directions predicted by reward maximization. These results suggest that rather than gradually adjusting their time-dependent choice behavior, mice abruptly adopted temporal decision strategies by directly integrating their previous knowledge of task parameters into their timed behavior, supporting the model-based representational account of temporal risk assessment. PMID:26733674

Can preventive care activities in general practice be sustained when financial incentives and external audit plus feedback are removed? ACCEPt-able: a cluster randomised controlled trial protocol.

PubMed

Hocking, Jane S; Temple-Smith, Meredith; van Driel, Mieke; Law, Matthew; Guy, Rebecca; Bulfone, Liliana; Wood, Anna; Low, Nicola; Donovan, Basil; Fairley, Christopher K; Kaldor, John; Gunn, Jane

2016-09-13

Financial incentives and audit plus feedback on performance are two strategies commonly used by governments to motivate general practitioners (GP) to undertake specific healthcare activities. However, in recent years, governments have reduced or removed incentive payments without evidence of the potential impact on GP behaviour and patient outcomes. This trial (known as ACCEPt-able) aims to determine whether preventive care activities in general practice are sustained when financial incentives and/or external audit plus feedback on preventive care activities are removed. The activity investigated is annual chlamydia testing for 16- to 29-year-old adults, a key preventive health strategy within this age group. ACCEPt-able builds on a large cluster randomised controlled trial (RCT) that evaluated a 3-year chlamydia testing intervention in general practice. GPs were provided with a support package to facilitate annual chlamydia testing of all sexually active 16- to 29-year-old patients. This package included financial incentive payments to the GP for each chlamydia test conducted and external audit plus feedback on each GP's chlamydia testing rates. ACCEPt-able is a factorial cluster RCT in which general practices are randomised to one of four groups: (i) removal of audit plus feedback-continue to receive financial incentive payments for each chlamydia test; (ii) removal of financial incentive payments-continue to receive audit plus feedback; (iii) removal of financial incentive payments and audit plus feedback; and (iv) continue financial incentive payments and audit plus feedback. The primary outcome is chlamydia testing rate measured as the proportion of sexually active 16- to 29-year-olds who have a GP consultation within a 12-month period and at least one chlamydia test. This will be the first RCT to examine the impact of removal of financial incentive payments and audit plus feedback on the chlamydia testing behaviour of GPs. This trial is particularly timely and will increase our understanding about the impact of financial incentives and audit plus feedback on GP behaviour when governments are looking for opportunities to control healthcare budgets and maximise clinical outcomes for money spent. The results of this trial will have implications for supporting preventive health measures beyond the content area of chlamydia. The trial has been registered on the Australian and New Zealand Clinical Trials Registry ( ACTRN12614000595617 ).

Younger and Older Adults Weigh Multiple Cues in a Similar Manner to Generate Judgments of Learning

PubMed Central

Hines, Jarrod C.; Hertzog, Christopher; Touron, Dayna R.

2015-01-01

One's memory for past test performance (MPT) is a key piece of information individuals use when deciding how to restudy material. We used a multi-trial recognition memory task to examine adult age differences in the influence of MPT (measured by actual Trial 1 memory accuracy and subjective confidence judgments, CJs) along with Trial 1 judgments of learning (JOLs), objective and participant-estimated recognition fluencies, and Trial 2 study time on Trial 2 JOLs. We found evidence of simultaneous and independent influences of multiple objective and subjective (i.e., metacognitive) cues on Trial 2 JOLs, and these relationships were highly similar for younger and older adults. Individual differences in Trial 1 recognition accuracy and CJs on Trial 2 JOLs indicate that individuals may vary in the degree to which they rely on each MPT cue when assessing subsequent memory confidence. Aging appears to spare the ability to access multiple cues when making JOLs. PMID:25827630

Poorer Intermittent Sprints Performance in Ramadan-Fasted Muslim Footballers despite Controlling for Pre-Exercise Dietary Intake, Sleep and Training Load

PubMed Central

Aziz, Abdul Rashid; Che Muhamad, Ahmad Munir; Roslan, Siti Raifana; Ghulam Mohamed, Nazirah; Singh, Rabindarjeet; Chia, Michael Yong Hwa

2017-01-01

This study examines the effects of Ramadan fasting on sprint performance during prolonged intermittent exercise in trained Muslim footballers, under controlled pre-exercise conditions. A within-group, cross-over study design with two non-fasted or Control trials performed before (i.e., CON1) and after (CON2) the Ramadan month, and with the Ramadan-fasted (RAM) trials performed within the Ramadan month. After familiarization, 14 players completed a modified 60-min (4 × 15-min exercise blocks interspersed with 3-min intervals) of the Loughborough Intermittent Shuttle Test (mLIST) of fixed speeds of walking, jogging, running, but with all-out effort sprints. During the interval periods, capillary blood glucose and blood lactate measures were taken, rectal and skin temperatures were recorded and maximal voluntary isometric contractions (MVIC) of the dominant leg and hand-grip were performed to provide some indication to the cause(s) of ‘fatigue’ during exercise. Players were provided with standardized 24-h pre-packed meals prior to all trials. Sleep hours were objectively assessed and perceived training loads were monitored and these were equivalent between RAM and CON trials. Sprint times throughout mLIST were significantly faster in both CON1 and CON2 as compared to RAM trials (all P < 0.017; d = small to moderate), and this poorer performance in RAM was observed as early as during the first 15-min of the mLIST. Blood markers, MVIC and thermoregulatory results were not substantially different between both CON and RAM trials. In conclusion, despite similarities in dietary intake, sleeping hours and training loads between conditions, results still indicate that Ramadan fasting had an adverse effect on prolonged intermittent performance. Nocebo effects plays a dominant role during exercise in the Ramadan-fasted state. PMID:29910364

Human sex differences in solving a virtual navigation problem.

PubMed

Astur, Robert S; Purton, Andrea J; Zaniewski, Melanie J; Cimadevilla, Jose; Markus, Etan J

2016-07-15

The current study examined sex differences in initial and subsequent strategies in solving a navigational problem within a virtual reality environment. We tested 163 undergraduates on a virtual T-maze task that included probe trials designed to assess whether participants were responding using either a place or response strategy. Participants were also tested on a mental rotation task and memory of the details of the virtual room. There were no differences between the sexes in copying or recalling a map of the room or on first trial performance of the T-maze. However, at trial two, males show a significant advantage in solving the task, and approximately 80% of the males adopt a place strategy to solve the T-maze whereas females at that point showed no strategy preference. Across all testing, both males and females preferentially used a place strategy. We discuss how factors such as spatial priming affect strategy preferences and how such factors may differentially affect males and females. Copyright © 2016 Elsevier B.V. All rights reserved.

Analytical performances of d-ROMs test and BAP test in canine plasma. Definition of the normal range in healthy Labrador dogs.

PubMed

Pasquini, A; Luchetti, E; Marchetti, V; Cardini, G; Iorio, E L

2008-02-01

An high level of ROS (Reactive Oxygen Species), due to an increased production of oxidant species and/or a decreased efficacy of antioxidant system, can lead to oxidative stress, an emerging health risk factor involved in the aging and in many diseases, including inflammatory, infectious and degenerative disorders, either in humans or in animals. In the last years some assays panels have been developed to globally evaluate the oxidative balance by means of the concomitant assessment of ROS production and antioxidant system capability. In this report, the validation trials of d-ROMs (Reactive Oxygen Metabolites- derived compounds) and BAP (Biological Antioxidant Potential) tests in canine specie are described and also the specific referral ranges are calculated in a Labrador population. The results of linearity, precision and accuracy trials show that both tests exhibit good to excellent analytical performances. The possibility of measuring oxidative stress in vivo with simple, cheap and accurate tests, d-ROMs test and BAP test, provides for the veterinarians a very suitable tool to monitor oxidative stress and to correctly choice of eventual antioxidant supplementations in diseases proven related to oxidative stress in animals and particularly in dogs. Further studies will be useful to confirm this possibility.

Selective Reminding and Free and Cued Selective Reminding in Mild Cognitive Impairment and Alzheimer Disease.

PubMed

Lemos, Raquel; Afonso, Ana; Martins, Cristina; Waters, James H; Blanco, Filipe Sobral; Simões, Mário R; Santana, Isabel

2016-01-01

The Selective Reminding Test (SRT) and the Free and Cued Selective Reminding Test (FCSRT) are multitrial memory tests that use a common "selective reminding" paradigm that aims to facilitate learning by presenting only the missing words from the previous recall trial. While in the FCSRT semantic cues are provided to elicit recall, in the SRT, participants are merely reminded of the missing items by repeating them. These tests have been used to assess age-related memory changes and to predict dementia. The performance of healthy elders on these tests has been compared before, and results have shown that twice as many words were retrieved from long-term memory in the FCSRT compared with the SRT. In this study, we compared the tests' properties and their accuracy in discriminating amnestic mild cognitive impairment (aMCI; n = 20) from Alzheimer disease (AD; n = 18). Patients with AD performed significantly worse than patients with aMCI on both tests. The percentage of items recalled during the learning trials was significantly higher for the FCSRT in both groups, and a higher number of items were later retrieved, showing the benefit of category cueing. Our key finding was that the FCSRT showed higher accuracy in discriminating patients with aMCI from those with AD.

An Analysis of Factors Affecting Successful Clinical Trial Enrollment in the Context of Three Prospective Randomized Control Trials

PubMed Central

Logan, Jennifer K; Tang, Chad; Liao, Zhongxing; Lee, J. Jack; Heymach, John V.; Swisher, Stephen G.; Welsh, James W.; Zhang, Jianjun; Lin, Steven H.; Gomez, Daniel R.

2018-01-01

Purpose Effective clinical trial enrollment can be difficult in a protocol designs that contain one treatment arm that is perceived as being more “aggressive” or “favorable.” There have been limited studies focusing on the barriers to enrollment and the efficacy of alternative study design to improve accrual. We analyzed barriers to enrollment, particularly the influence of timing, in context of three prospective randomized oncology trials where one arm was considered more aggressive. Methods and materials From June 2011 to March 2015, patients who were enrolled on three prospective institutional protocols (an oligometastatic non-small cell lung cancer (NSCLC) trial, and two proton vs. intensity-modulated radiation therapy (IMRT) trials in NSCLC and esophageal cancer) were screened for protocol eligibility. Eligible candidates were approached about trial participation, and patient characteristics (age, sex, T/N categorization) were recorded along with details surrounding trial presentation (appointment number). Fisher’s exact test, Student’s t tests, and multivariate analysis were performed to assess differences between enrolled and refusal patients. Results 309 eligible patients were approached about trial enrollment. The enrollment success rate (ESR) during this time span was 52% (n=160 patients). Enrolled patients were more likely to be presented trial information at an earlier appointment (oligomet protocol: 5 vs. 3 appointments (P<0.001), NSCLC protocol: 4 vs. 3 appointments (P = 0.0018), esophageal protocol: 3 vs. 2 appointments (P = 0.0086No other factors or patient characteristics significantly affected ESR. Conclusion Improvement in enrollment rates for randomized control trials is possible, even in difficult accrual settings. Earlier presentation of trial information to patients is the most influential factor for success, and may help overcome accrual barriers without compromising trial design. PMID:28244413

A modified haemagglutination inhibition test for rubella antibodies, using standardized, freeze-dried reagents. Report of a comparative multi-centre trial.

PubMed Central

van Weemen, B.; Kacaki, J.

1976-01-01

A modified haemagglutination inhibition test for rubella antibodies, using standardized freeze-dried reagents, was developed and compared with haemagglutination inhibition tests using fresh erythrocytes. This comparison was made in collaboration with six European laboratories. A total of 4205 serum samples were tested. The results show that: (1) Sensitivity and reliability of the modified test are good; (2) the modified test can be performed in polystyrene microtitration plates. PMID:789763

Laboratory Study on Macro-Features of Wave Breaking Over Bars and Artificial Reefs

DTIC Science & Technology

1990-07-01

Prototype and Model Conditions of Case CE400 ( Pilot Test ) . 72 7 List of Design Parameters for Base Tests ... ........... . 72 8 List of Design Parameters...bar configurations, and the procedure was repeated. Pilot test 112. A pilot test was performed as a trial of the methodology and vali- dation of the...criterion on bar depth given by Larson and Kraus (1989) prior to actual testing . In this pilot test , the wave conditions and equilibrium bar formed in a

Audiovisual integration facilitates monkeys' short-term memory.

PubMed

Bigelow, James; Poremba, Amy

2016-07-01

Many human behaviors are known to benefit from audiovisual integration, including language and communication, recognizing individuals, social decision making, and memory. Exceptionally little is known about the contributions of audiovisual integration to behavior in other primates. The current experiment investigated whether short-term memory in nonhuman primates is facilitated by the audiovisual presentation format. Three macaque monkeys that had previously learned an auditory delayed matching-to-sample (DMS) task were trained to perform a similar visual task, after which they were tested with a concurrent audiovisual DMS task with equal proportions of auditory, visual, and audiovisual trials. Parallel to outcomes in human studies, accuracy was higher and response times were faster on audiovisual trials than either unisensory trial type. Unexpectedly, two subjects exhibited superior unimodal performance on auditory trials, a finding that contrasts with previous studies, but likely reflects their training history. Our results provide the first demonstration of a bimodal memory advantage in nonhuman primates, lending further validation to their use as a model for understanding audiovisual integration and memory processing in humans.

Growing literature, stagnant science? Systematic review, meta-regression and cumulative analysis of audit and feedback interventions in health care.

PubMed

Ivers, Noah M; Grimshaw, Jeremy M; Jamtvedt, Gro; Flottorp, Signe; O'Brien, Mary Ann; French, Simon D; Young, Jane; Odgaard-Jensen, Jan

2014-11-01

This paper extends the findings of the Cochrane systematic review of audit and feedback on professional practice to explore the estimate of effect over time and examine whether new trials have added to knowledge regarding how optimize the effectiveness of audit and feedback. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE for randomized trials of audit and feedback compared to usual care, with objectively measured outcomes assessing compliance with intended professional practice. Two reviewers independently screened articles and abstracted variables related to the intervention, the context, and trial methodology. The median absolute risk difference in compliance with intended professional practice was determined for each study, and adjusted for baseline performance. The effect size across studies was recalculated as studies were added to the cumulative analysis. Meta-regressions were conducted for studies published up to 2002, 2006, and 2010 in which characteristics of the intervention, the recipients, and trial risk of bias were tested as predictors of effect size. Of the 140 randomized clinical trials (RCTs) included in the Cochrane review, 98 comparisons from 62 studies met the criteria for inclusion. The cumulative analysis indicated that the effect size became stable in 2003 after 51 comparisons from 30 trials. Cumulative meta-regressions suggested new trials are contributing little further information regarding the impact of common effect modifiers. Feedback appears most effective when: delivered by a supervisor or respected colleague; presented frequently; featuring both specific goals and action-plans; aiming to decrease the targeted behavior; baseline performance is lower; and recipients are non-physicians. There is substantial evidence that audit and feedback can effectively improve quality of care, but little evidence of progress in the field. There are opportunity costs for patients, providers, and health care systems when investigators test quality improvement interventions that do not build upon, or contribute toward, extant knowledge.

Secondary mediation and regression analyses of the PTClinResNet database: determining causal relationships among the International Classification of Functioning, Disability and Health levels for four physical therapy intervention trials.

PubMed

Mulroy, Sara J; Winstein, Carolee J; Kulig, Kornelia; Beneck, George J; Fowler, Eileen G; DeMuth, Sharon K; Sullivan, Katherine J; Brown, David A; Lane, Christianne J

2011-12-01

Each of the 4 randomized clinical trials (RCTs) hosted by the Physical Therapy Clinical Research Network (PTClinResNet) targeted a different disability group (low back disorder in the Muscle-Specific Strength Training Effectiveness After Lumbar Microdiskectomy [MUSSEL] trial, chronic spinal cord injury in the Strengthening and Optimal Movements for Painful Shoulders in Chronic Spinal Cord Injury [STOMPS] trial, adult stroke in the Strength Training Effectiveness Post-Stroke [STEPS] trial, and pediatric cerebral palsy in the Pediatric Endurance and Limb Strengthening [PEDALS] trial for children with spastic diplegic cerebral palsy) and tested the effectiveness of a muscle-specific or functional activity-based intervention on primary outcomes that captured pain (STOMPS, MUSSEL) or locomotor function (STEPS, PEDALS). The focus of these secondary analyses was to determine causal relationships among outcomes across levels of the International Classification of Functioning, Disability and Health (ICF) framework for the 4 RCTs. With the database from PTClinResNet, we used 2 separate secondary statistical approaches-mediation analysis for the MUSSEL and STOMPS trials and regression analysis for the STEPS and PEDALS trials-to test relationships among muscle performance, primary outcomes (pain related and locomotor related), activity and participation measures, and overall quality of life. Predictive models were stronger for the 2 studies with pain-related primary outcomes. Change in muscle performance mediated or predicted reductions in pain for the MUSSEL and STOMPS trials and, to some extent, walking speed for the STEPS trial. Changes in primary outcome variables were significantly related to changes in activity and participation variables for all 4 trials. Improvement in activity and participation outcomes mediated or predicted increases in overall quality of life for the 3 trials with adult populations. Variables included in the statistical models were limited to those measured in the 4 RCTs. It is possible that other variables also mediated or predicted the changes in outcomes. The relatively small sample size in the PEDALS trial limited statistical power for those analyses. Evaluating the mediators or predictors of change between each ICF level and for 2 fundamentally different outcome variables (pain versus walking) provided insights into the complexities inherent across 4 prevalent disability groups.

Is HPV DNA testing specificity comparable to that of cytological testing in primary cervical cancer screening? Results of a meta-analysis of randomized controlled trials.

PubMed

Pileggi, Claudia; Flotta, Domenico; Bianco, Aida; Nobile, Carmelo G A; Pavia, Maria

2014-07-01

Human-papillomavirus (HPV) DNA testing has been proposed as an alternative to primary cervical cancer screening using cytological testing. Review of the evidence shows that available data are conflicting for some aspects. The overall goal of the study is to update the performance of HPV DNA as stand-alone testing in primary cervical cancer screening, focusing particularly on the aspects related to the specificity profile of the HPV DNA testing in respect to cytology. We performed a meta-analysis of randomized controlled clinical trials. Eight articles were included in the meta-analysis. Three outcomes have been investigated: relative detection, relative specificity, and relative positive predictive value (PPV) of HPV DNA testing versus cytology. Overall evaluation of relative detection showed a significantly higher detection of CIN2+ and CIN3+ for HPV DNA testing versus cytology. Meta-analyses that considered all age groups showed a relative specificity that favored the cytology in detecting both CIN2+ and CIN3+ lesions whereas, in the ≥30 years' group, specificity of HPV DNA and cytology tests was similar in detecting both CIN2+ and CIN3+ lesions. Results of the pooled analysis on relative PPV showed a not significantly lower PPV of HPV DNA test over cytology. A main key finding of the study is that in women aged ≥30, has been found an almost overlapping specificity between the two screening tests in detecting CIN2 and above-grade lesions. Therefore, primary screening of cervical cancer by HPV DNA testing appears to offer the right balance between maximum detection of CIN2+ and adequate specificity, if performed in the age group ≥30 years. © 2013 UICC.

Use of proficiency samples to assess diagnostic laboratories in France performing a Trichinella digestion assay.

PubMed

Vallée, Isabelle; Macé, Pauline; Forbes, Lorry; Scandrett, Brad; Durand, Benoit; Gajadhar, Alvin; Boireau, Pascal

2007-07-01

Routine diagnosis of animal trichinellosis for food safety and trade relies on a method of artificial digestion to free Trichinella muscle larvae from meat for subsequent identification by microscopy. As part of a quality control system, the French National Reference Laboratory (NRL) initiated ring trials to determine the sensitivity of the test performed in the 72 routine diagnostic laboratories in France. A method was devised to obtain calibrated meat samples containing known numbers of capsules with Trichinella spiralis muscle larvae. This method was based on an incomplete artificial digestion of Trichinella-infected mice carcasses to allow the collection of intact Trichinella capsules. Capsules were placed into a meatball of 100 +/- 2 g of pork and horsemeat to produce proficiency samples. Three categories of samples were prepared: small (3 to 5 capsules), medium (7 to 10), and large (12 to 15). The sensitivity was expressed as the percentage of muscle larvae recovered from each proficiency sample. Reproducibility was tested with ring trials organized between two NRLs (France and Canada), and a reference sensitivity of 84.9% was established. National ring trials were then organized in France, with the 72 routine diagnostic laboratories each receiving four proficiency samples per session. After five sessions, an improvement in the digest test sensitivity was observed. Results at the fifth session indicated sensitivities of 78.60% +/- 23.70%, 81.19% +/- 19.59%, and 80.52% +/- 14.71% muscle larvae for small, medium, and large samples, respectively. This study supports the use of proficiency samples to accurately evaluate the performance of routine diagnostic laboratories that conduct digestion tests for animal trichinellosis diagnosis.

Age and education adjusted normative data and discriminative validity for Rey's Auditory Verbal Learning Test in the elderly Greek population.

PubMed

Messinis, Lambros; Nasios, Grigorios; Mougias, Antonios; Politis, Antonis; Zampakis, Petros; Tsiamaki, Eirini; Malefaki, Sonia; Gourzis, Phillipos; Papathanasopoulos, Panagiotis

2016-01-01

Rey's Auditory Verbal Learning Test (RAVLT) is a widely used neuropsychological test to assess episodic memory. In the present study we sought to establish normative and discriminative validity data for the RAVLT in the elderly population using previously adapted learning lists for the Greek adult population. We administered the test to 258 cognitively healthy elderly participants, aged 60-89 years, and two patient groups (192 with amnestic mild cognitive impairment, aMCI, and 65 with Alzheimer's disease, AD). From the statistical analyses, we found that age and education contributed significantly to most trials of the RAVLT, whereas the influence of gender was not significant. Younger elderly participants with higher education outperformed the older elderly with lower education levels. Moreover, both clinical groups performed significantly worse on most RAVLT trials and composite measures than matched cognitively healthy controls. Furthermore, the AD group performed more poorly than the aMCI group on most RAVLT variables. Receiver operating characteristic (ROC) analysis was used to examine the utility of the RAVLT trials to discriminate cognitively healthy controls from aMCI and AD patients. Area under the curve (AUC), an index of effect size, showed that most of the RAVLT measures (individual and composite) included in this study adequately differentiated between the performance of healthy elders and aMCI/AD patients. We also provide cutoff scores in discriminating cognitively healthy controls from aMCI and AD patients, based on the sensitivity and specificity of the prescribed scores. Moreover, we present age- and education-specific normative data for individual and composite scores for the Greek adapted RAVLT in elderly subjects aged between 60 and 89 years for use in clinical and research settings.

Individual differences in infant fearfulness and cognitive performance: a testing, performance, or competence effect?

PubMed

Rieser-Danner, Loretta A

2003-02-01

The author conducted 2 studies to examine the relations between infant fear and cognitive testing performance in 12-month-old infants. In Study 1, fear was assessed by using 2 standard temperament questionnaires and a laboratory-based, standardized stranger approach. Individual differences in cognitive development were assessed using the Object Permanence Scale of the Infant Psychological Development Scales (I. C. Uzgiris & J. M. Hunt, 1975). All 3 assessments of fear significantly predicted object permanence performance, with correlations ranging from -.32 to -.35. In Study 2, fear was assessed via a maternal report questionnaire, and habituation performance was assessed via a basic-level categorization task. Familiarity with the examiner and with the testing environment was manipulated to test for a familiarity influence on performance. Testing revealed individual differences in both fear and habituation. Results suggest that highly fearful infants required more trials to habituate and were less likely to meet the habituation criterion than infants who were less fearful. Methodological and conceptual implications of these results are discussed.

Type I error probabilities based on design-stage strategies with applications to noninferiority trials.

PubMed

Rothmann, Mark

2005-01-01

When testing the equality of means from two different populations, a t-test or large sample normal test tend to be performed. For these tests, when the sample size or design for the second sample is dependent on the results of the first sample, the type I error probability is altered for each specific possibility in the null hypothesis. We will examine the impact on the type I error probabilities for two confidence interval procedures and procedures using test statistics when the design for the second sample or experiment is dependent on the results from the first sample or experiment (or series of experiments). Ways for controlling a desired maximum type I error probability or a desired type I error rate will be discussed. Results are applied to the setting of noninferiority comparisons in active controlled trials where the use of a placebo is unethical.

Testing equality and interval estimation in binary responses when high dose cannot be used first under a three-period crossover design.

PubMed

Lui, Kung-Jong; Chang, Kuang-Chao

2015-01-01

When comparing two doses of a new drug with a placebo, we may consider using a crossover design subject to the condition that the high dose cannot be administered before the low dose. Under a random-effects logistic regression model, we focus our attention on dichotomous responses when the high dose cannot be used first under a three-period crossover trial. We derive asymptotic test procedures for testing equality between treatments. We further derive interval estimators to assess the magnitude of the relative treatment effects. We employ Monte Carlo simulation to evaluate the performance of these test procedures and interval estimators in a variety of situations. We use the data taken as a part of trial comparing two different doses of an analgesic with a placebo for the relief of primary dysmenorrhea to illustrate the use of the proposed test procedures and estimators.

Full suspension mountain bike improves off-road cycling performance.

PubMed

Nishii, T; Umemura, Y; Kitagawa, K

2004-12-01

The purpose of the present study was to determine the effects of suspension systems on the cycling performance of cyclists during off-road bicycling. Eight elite male cyclists (67.8+/-5.8 ml/min/kg of (.-)VO(2max)) performed 30-minute riding tests on bicycles with 2 different suspension setups: front suspension (FS) and front and rear suspension (FRS). Heart rate, blood lactate concentration, pedaling power, cadence, cycling velocity, and completed distance during the trial were measured creatin kinase (CK), lactic dehydrogenase (LDH) and glutamic-oxaloacetic transaminase (GOT) were measured before and after the trials. The average cadence during the trial was significantly higher (p<0.05) with the FRS (73.6+/-6.1 rpm) than the FS (70.2+/-6.2 rpm). Subjects rode significantly faster (p<0.05) on FRS (24.1+/-2.6 km/h) than FS bikes (22.9+/-2.4 km/h), although no significant difference was observed in pedaling power (240.7+/-26.6 W vs 242.2+/-28.8 W, FS vs FRS, respectively). Serum creatin kinase increased significantly (p<0.05) at 24 h after the trial when cyclists exercised with the FS bike. We conclude that the FRS improved cycling performance over rough terrain. FRS might therefore be more suitable for cross-country mountain bike races.

Changing case Order to Optimise patterns of Performance in mammography Screening (CO-OPS): study protocol for a randomized controlled trial

PubMed Central

2014-01-01

Background X-ray mammography remains the predominant test for screening for breast cancer, with the aim of reducing breast cancer mortality. In the English NHS Breast Screening Programme each woman’s mammograms are examined separately by two expert readers. The two readers read each batch in the same order and each indicates if there should be recall for further tests. This is a highly skilled, pressurised, repetitive and frequently intellectually unchallenging activity where readers examine one or more batches of 30–50 women’s mammograms in each session. A vigilance decrement or performance decrease over time has been observed in similar repetitive visual tasks such as radar operation. Methods/Design The CO-OPS study is a pragmatic, multi-centre, two-arm, double blind cluster randomised controlled trial of a computer software intervention designed to reduce the effects of a vigilance decrement in breast cancer screening. The unit of randomisation is the batch. Intervention batches will be examined in the opposite order by the two readers (one forwards, one backwards). Control batches will be read in the same order as one another, as is current standard practice. The hypothesis is that cancer detection rates will be higher in the intervention group because each readers’ peak performance will occur when examining different women’s mammograms. The trial will take place in 44 English breast screening centres for 1 year and 4 months. The primary outcome is cancer detection rate, which will be extracted from computer records after 1 year of the trial. The secondary outcomes include rate of disagreement between readers (a more statistically powerful surrogate for cancer detection rate), recall rate, positive predictive value, and interval cancer rate (cancers found between screening rounds which will be measured three years after the end of the trial). Discussion This is the first trial of an intervention to ameliorate a vigilance decrement in breast cancer screening. Trial registration ISRCTN46603370 (submitted: 24 October 2012, date of registration: 26 March 2013). PMID:24411004

Quantitative methods in assessment of neurologic function.

PubMed

Potvin, A R; Tourtellotte, W W; Syndulko, K; Potvin, J

1981-01-01

Traditionally, neurologists have emphasized qualitative techniques for assessing results of clinical trials. However, in recent years qualitative evaluations have been increasingly augmented by quantitative tests for measuring neurologic functions pertaining to mental state, strength, steadiness, reactions, speed, coordination, sensation, fatigue, gait, station, and simulated activities of daily living. Quantitative tests have long been used by psychologists for evaluating asymptomatic function, assessing human information processing, and predicting proficiency in skilled tasks; however, their methodology has never been directly assessed for validity in a clinical environment. In this report, relevant contributions from the literature on asymptomatic human performance and that on clinical quantitative neurologic function are reviewed and assessed. While emphasis is focused on tests appropriate for evaluating clinical neurologic trials, evaluations of tests for reproducibility, reliability, validity, and examiner training procedures, and for effects of motivation, learning, handedness, age, and sex are also reported and interpreted. Examples of statistical strategies for data analysis, scoring systems, data reduction methods, and data display concepts are presented. Although investigative work still remains to be done, it appears that carefully selected and evaluated tests of sensory and motor function should be an essential factor for evaluating clinical trials in an objective manner.

STATIC STRETCHING DOES NOT REDUCE VARIABILITY, JUMP AND SPEED PERFORMANCE.

PubMed

de Oliveira, Fábio Carlos Lucas; Rama, Luís Manuel Pinto Lopes

2016-04-01

Stretching is often part of the warm-up routine prior to athletic participation; however, controversial evidence exists on the effects of stretching on countermovement jump (CMJ) and sprint performance. Additionally, analysis of variability between repeated tasks is useful for monitoring players, to analyze factors that could affect the performance, and to guide clinical decisions for training strategies. The purpose of this study was to examine whether static stretching (SS) prior to CMJ and 20-meter (20-m) sprint would affect performance, and to investigate whether SS affects an athlete's ability to perform these tasks consistently. Twenty-two trained healthy athletes (23.2 ± 5.0 years) attended, randomly, two testing sessions, separated by 48 hours. At session one, all participants underwent 10 minutes of dynamic running warm-up followed by the experimental tasks (three CMJ and three 20-m sprint), whereas five minutes of stretching was added after the warm-up routine at session two. All participants performed the same experimental tasks in both sessions. The stretching protocol consisted of five stretching exercises for each lower limb. The paired-samples t-test revealed no significant differences between the stretching protocol condition and no stretching condition for the 20-m sprint (t(21)=.920; p=.368) and CMJ (t(21)=.709; p=.486). There were no significant differences in trial-by-trial variability on 20-m sprint (t(21)=1.934; p=.067) and CMJ scores (t(21)=.793; p=.437) as result of SS. The SS protocol did not modify jumping and running ability in trained healthy athletes. The SS prior to training or competition may not cause detrimental effects to athletic performance. Level III, Nonrandomized controlled trial.

STATIC STRETCHING DOES NOT REDUCE VARIABILITY, JUMP AND SPEED PERFORMANCE

PubMed Central

Rama, Luís Manuel Pinto Lopes

2016-01-01

Background Stretching is often part of the warm-up routine prior to athletic participation; however, controversial evidence exists on the effects of stretching on countermovement jump (CMJ) and sprint performance. Additionally, analysis of variability between repeated tasks is useful for monitoring players, to analyze factors that could affect the performance, and to guide clinical decisions for training strategies. Purpose The purpose of this study was to examine whether static stretching (SS) prior to CMJ and 20-meter (20-m) sprint would affect performance, and to investigate whether SS affects an athlete's ability to perform these tasks consistently. Methods Twenty-two trained healthy athletes (23.2 ± 5.0 years) attended, randomly, two testing sessions, separated by 48 hours. At session one, all participants underwent 10 minutes of dynamic running warm-up followed by the experimental tasks (three CMJ and three 20-m sprint), whereas five minutes of stretching was added after the warm-up routine at session two. All participants performed the same experimental tasks in both sessions. The stretching protocol consisted of five stretching exercises for each lower limb. Results The paired-samples t-test revealed no significant differences between the stretching protocol condition and no stretching condition for the 20-m sprint (t(21)=.920; p=.368) and CMJ (t(21)=.709; p=.486). There were no significant differences in trial-by-trial variability on 20-m sprint (t(21)=1.934; p=.067) and CMJ scores (t(21)=.793; p=.437) as result of SS. Conclusion The SS protocol did not modify jumping and running ability in trained healthy athletes. The SS prior to training or competition may not cause detrimental effects to athletic performance. Level of evidence Level III, Nonrandomized controlled trial. PMID:27104057

The Efficacy of an 8-Week Concurrent Strength and Endurance Training Programme on Hand Cycling Performance.

PubMed

Nevin, Jonpaul; Waldron, Mark; Patterson, Stephen; Smith, Paul; Price, Mike; Hunt, Alex

2018-03-20

The aim of the present study was to investigate the effects of an 8-week concurrent strength and endurance training programme in comparison to endurance training only on several key determinants of hand cycling performance. Five H4 and five H3 classified hand cyclists with at least one year's hand cycling training history consented to participate in the study. Subjects underwent a battery of tests to establish body mass, body composition, VO2peak, maximum aerobic power, gross mechanical efficiency, maximal upper body strength, and 30 km time trial performance. Subjects were matched into pairs based upon 30 km time trial performance and randomly allocated to either a concurrent strength and endurance or endurance training only, intervention group. Following an 8-week training programme based upon a conjugated block periodisation model, subjects completed a second battery of tests. A mixed model, 2-way analysis of variance (ANOVA) revealed no significant changes between groups. However, the calculation of effect sizes (ES) revealed that both groups demonstrated a positive improvement in most physiological and performance measures with subjects in the concurrent group demonstrating a greater magnitude of improvement in body composition (ES -0.80 vs. -0.22) maximal aerobic power (ES 0.97 vs. 0.28), gross mechanical efficiency (ES 0.87 vs. 0.63), bench press 1 repetition maximum (ES 0.53 vs. 0.33), seated row 1 repetition maximum (ES 1.42 vs. 0.43), and 30 km time trial performance (ES -0.66 vs. -0.30). In comparison to endurance training only, an 8-week concurrent training intervention based upon a conjugated block periodisation model appears to be a more effective training regime for improving the performance capabilities of hand cyclists.

A randomized controlled trial of an activity specific exercise program for individuals with Alzheimer disease in long-term care settings.

PubMed

Roach, Kathryn E; Tappen, Ruth M; Kirk-Sanchez, Neva; Williams, Christine L; Loewenstein, David

2011-01-01

To determine whether an activity specific exercise program could improve ability to perform basic mobility activities in long-term care residents with Alzheimer disease (AD). Randomized, controlled, single-blinded clinical trial. Residents of 7 long-term care facilities. Eighty-two long-term care residents with mild to severe AD. An activity specific exercise program was compared to a walking program and to an attention control. Ability to perform bed mobility and transfers was assessed using the subscales of the Acute Care Index of Function; functional mobility was measured using the 6-Minute Walk test. Subjects receiving the activity specific exercise program improved in ability to perform transfers, whereas subjects in the other 2 groups declined.

Object permanence in common marmosets (Callithrix jacchus).

PubMed

Mendes, Natacha; Huber, Ludwig

2004-03-01

A series of 9 search tasks corresponding to the Piagetian Stages 3-6 of object permanence were administered to 11 common marmosets (Callithrix jacchus). Success rates varied strongly among tasks and marmosets, but the performances of most subjects were above chance level on the majority of tasks of visible and invisible displacements. Although up to 24 trials were administered in the tests, subjects did not improve their performance across trials. Errors were due to preferences for specific locations or boxes, simple search strategies, and attentional deficits. The performances of at least 2 subjects that achieved very high scores up to the successive invisible displacement task suggest that this species is able to represent the existence and the movements of unperceived objects. ((c) 2004 APA, all rights reserved)

Integrating Comparative Effectiveness Design Elements and Endpoints Into a Phase III, Randomized Clinical Trial (SWOG S1007) Evaluating OncotypeDX-Guided Management for Women With Breast Cancer Involving Lymph Nodes

PubMed Central

Ramsey, Scott D.; Barlow, William E.; Gonzalez-Angulo, Ana M.; Tunis, Sean; Baker, Laurence; Crowley, John; Deverka, Patricia; Veenstra, David; Hortobagyi, Gabriel N.

2012-01-01

Women with breast cancer involving the lymph nodes are typically treated with cytotoxic chemotherapy. Retrospective evaluations of prior studies suggest that the 21-gene test (OncotypeDX®), may allow identification of those who can safely avoid chemotherapy. To better understand the performance of the 21-gene test, the RxPONDER (Rx for Positive Node, Endocrine Responsive breast cancer) study was designed, a multicenter Phase III trial randomizing women with hormone receptor-positive and HER2-negative breast cancer involving 1–3 lymph nodes and a 21-gene assay recurrence score (RS) of 25 or less to endocrine therapy alone versus chemotherapy followed by endocrine therapy. As one of the first large-scale comparative-effectiveness studies in oncology, RxPONDER utilized an external stakeholder group to help inform the design of the trial. Stakeholders met with representatives of SWOG over several months through a structured discussion process. The stakeholder engagement process resulted in several changes being made to the trial design. In addition, stakeholder representatives from the health insurance industry provided guidance regarding a mechanism whereby the costs of OncotypeDX® would be paid by the majority of health insurers as part of the trial. The process may serve as a template for future studies evaluating the comparative effectiveness of genomic tests in oncology, particularly those that are conducted within cooperative clinical trials groups. PMID:23000081

The effect of the combination of acids and tannin in diet on the performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs.

PubMed

Stukelj, Marina; Valencak, Zdravko; Krsnik, Mladen; Svete, Alenka Nemec

2010-03-06

The abolition of in-feed antibiotics or chemotherapeutics as growth promoters have stimulated the swine industry to look for alternatives such as organic acids, botanicals, probiotics and tannin. The objective of the present study was to compare the effects of a combination of acids and tannin with diet with organic acids and diet without growth promoters on the growth performance and selected biochemical, haematological and antioxidant enzyme parameters in grower pigs. Tannin is more natural and cheaper but possibly with the same effectiveness as organic acids with regard to growth performance. Thirty-six 7 week old grower pigs, divided into three equal groups, were used in a three week feeding trial. Group I was fed basal diet, group II basal diet with added organic acids and group III basal diet with added organic and inorganic acids and tannin. Pigs were weighed before and after feeding and observed daily. Blood was collected before and after the feeding trial for the determination of selected biochemical, haematological and antioxidant enzyme parameters. One-way ANOVA was used to assess any diet related changes of all the parameters. Paired t-test was used to evaluate changes of blood parameters individually in each group of growers before and after feeding. No clinical health problems related to diet were noted during the three week feeding trial. The average daily gain (ADG) and selected blood parameters were not affected by the addition to basal diet of either acids and tannin or of organic acids alone. Selected blood parameters remained within the reference range before and after the feeding trial, with the exception of total serum proteins that were below the lower value of reference range at both times. The significant changes (paired t-test) observed in individual groups before and after the feeding trial are related to the growth of pigs. Diet with acids and tannin did not improve the growth performance of grower pigs but had no deleterious effects on selected blood parameters. The possibility of beneficial effects of adding acids and tannin in diets on growth performance over a longer period, however, could not be excluded.

Use of biochemical tests of placental function for improving pregnancy outcome.

PubMed

Heazell, Alexander E P; Whitworth, Melissa; Duley, Lelia; Thornton, Jim G

2015-11-25

The placenta has an essential role in determining the outcome of pregnancy. Consequently, biochemical measurement of placentally-derived factors has been suggested as a means to improve fetal and maternal outcome of pregnancy. To assess whether clinicians' knowledge of the results of biochemical tests of placental function is associated with improvement in fetal or maternal outcome of pregnancy. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2015) and reference lists of retrieved studies. Randomised, cluster-randomised or quasi-randomised controlled trials assessing the merits of the use of biochemical tests of placental function to improve pregnancy outcome.Studies were eligible if they compared women who had placental function tests and the results were available to their clinicians with women who either did not have the tests, or the tests were done but the results were not available to the clinicians. The placental function tests were any biochemical test of placental function carried out using the woman's maternal biofluid, either alone or in combination with other placental function test/s. Two review authors independently assessed trials for inclusion, extracted data and assessed trial quality. Authors of published trials were contacted for further information. Three trials were included, two quasi-randomised controlled trials and one randomised controlled trial. One trial was deemed to be at low risk of bias while the other two were at high risk of bias. Different biochemical analytes were measured - oestrogen was measured in one trial and the other two measured human placental lactogen (hPL). One trial did not contribute outcome data, therefore, the results of this review are based on two trials with 740 participants.There was no evidence of a difference in the incidence of death of a baby (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.36 to 2.13, two trials, 740 participants (very low quality evidence)) or the frequency of a small-for-gestational-age infant (RR 0.44, 95% CI 0.16 to 1.19, one trial, 118 participants (low quality evidence)).In terms of this review's secondary outcomes, there was no evidence of a clear difference between women who had biochemical tests of placental function compared with standard antenatal care for the incidence of stillbirth (RR 0.56, 95% CI 0.16 to 1.88, two trials, 740 participants (very low quality evidence)) or neonatal death (RR 1.62, 95% CI 0.39 to 6.74, two trials, 740 participants, very low quality evidence)) although the directions of any potential effect were in opposing directions. There was no evidence of a difference between groups in elective delivery (RR 0.98, 95% CI 0.84 to 1.14, two trials, 740 participants (low quality evidence)), caesarean section (one trial, RR 0.48, 95% CI 0.15 to 1.52, one trial, 118 participants (low quality evidence)), change in anxiety score (mean difference -2.40, 95% CI -4.78 to -0.02, one trial, 118 participants), admissions to neonatal intensive care (RR 0.32, 95% CI 0.03 to 3.01, one trial, 118 participants), and preterm birth before 37 weeks' gestation (RR 2.90, 95% CI 0.12 to 69.81, one trial, 118 participants). One trial (118 participants) reported that there were no cases of serious neonatal morbidity. Maternal death was not reported.A number of this review's secondary outcomes relating to the baby were not reported in the included studies, namely: umbilical artery pH < 7.0, neonatal intensive care for more than seven days, very preterm birth (< 32 weeks' gestation), need for ventilation, organ failure, fetal abnormality, neurodevelopment in childhood (cerebral palsy, neurodevelopmental delay). Similarly, a number of this review's maternal secondary outcomes were not reported in the included studies (admission to intensive care, high dependency unit admission, hospital admission for > seven days, pre-eclampsia, eclampsia, and women's perception of care). There is insufficient evidence to support the use of biochemical tests of placental function to reduce perinatal mortality or increase identification of small-for-gestational-age infants. However, we were only able to include data from two studies that measured oestrogens and hPL. The quality of the evidence was low or very low.Two of the trials were performed in the 1970s on women with a variety of antenatal complications and this evidence cannot be generalised to women at low-risk of complications or groups of women with specific pregnancy complications (e.g. fetal growth restriction). Furthermore, outcomes described in the 1970s may not reflect what would be expected at present. For example, neonatal mortality rates have fallen substantially, such that an infant delivered at 28 weeks would have a greater chance of survival were those studies repeated; this may affect the primary outcome of the meta-analysis.With data from just two studies (740 women), this review is underpowered to detect a difference in the incidence of death of a baby or the frequency of a small-for-gestational-age infant as these have a background incidence of approximately 0.75% and 10% of pregnancies respectively. Similarly, this review is underpowered to detect differences between serious and/or rare adverse events such as severe neonatal morbidity. Two of the three included studies were quasi-randomised, with significant risk of bias from group allocation. Additionally, there may be performance bias as in one of the two studies contributing data, participants receiving standard care did not have venepuncture, so clinicians treating participants could identify which arm of the study they were in. Future studies should consider more robust randomisation methods and concealment of group allocation and should be adequately powered to detect differences in rare adverse events.The studies identified in this review examined two different analytes: oestrogens and hPL. There are many other placental products that could be employed as surrogates of placental function, including: placental growth factor (PlGF), human chorionic gonadotrophin (hCG), plasma protein A (PAPP-A), placental protein 13 (PP-13), pregnancy-specific glycoproteins and progesterone metabolites and further studies should be encouraged to investigate these other placental products. Future randomised controlled trials should test analytes identified as having the best predictive reliability for placental dysfunction leading to small-for-gestational-age infants and perinatal mortality.

PLCO Ovarian Phase III Validation Study — EDRN Public Portal

Cancer.gov

Our preliminary data indicate that the performance of CA 125 as a screening test for ovarian cancer can be improved upon by additional biomarkers. With completion of one additional validation step, we will be ready to test the performance of a consensus marker panel in a phase III validation study. Given the original aims of the PLCO trial, we believe that the PLCO represents an ideal longitudinal cohort offering specimens for phase III validation of ovarian cancer biomarkers.

Comparative effectiveness of coronary CT angiography vs stress cardiac imaging in patients following hospital admission for chest pain work-up: The Prospective First Evaluation in Chest Pain (PERFECT) Trial.

PubMed

Uretsky, Seth; Argulian, Edgar; Supariwala, Azhar; Agarwal, Shiv K; El-Hayek, Georges; Chavez, Patricia; Awan, Hira; Jagarlamudi, Ashadevi; Puppala, Siva P; Cohen, Randy; Rozanski, Alan

2017-08-01

Because the frequency of cardiac event rates is low among chest pain patients following either performance of coronary CT angiography (CCTA) or stress testing, there is a need to better assess how these tests influence the central management decisions that follow from cardiac testing. The present study was performed to assess the relative impact of CCTA vs stress testing on medical therapies and downstream resource utilization among patients admitted for the work-up of chest pain. The admitted patients were randomized in a 1:1 ratio to either cardiac imaging stress test or CCTA. Primary outcomes were time to discharge, change in medication usage, and frequency of downstream testing, cardiac interventions, and cardiovascular re-hospitalizations. We randomized 411 patients, 205 to stress testing, and 206 to CCTA. There were no differences in time to discharge or initiation of new cardiac medications at discharge. At 1 year follow-up, there was no difference in the number of patients who underwent cardiovascular downstream tests in the CCTA vs stress test patients (21% vs 15%, P = .1) or cardiovascular hospitalizations (14% vs 16%, P = .5). However, there was a higher frequency of invasive angiography in the CCTA group (11% vs 2%, P = .001) and percutaneous coronary interventions (6% vs 0%, P < .001). Randomization of hospitalized patients admitted for chest pain work-up to either CCTA or to stress testing resulted in similar discharge times, change in medical therapies at discharge, frequency of downstream noninvasive testing, and repeat hospitalizations. However, a higher frequency of invasive coronary angiography and revascularization procedures were performed in the CCTA arm. (ClinicalTrials.gov number, NCT01604655.).

Detecting deficits in change of direction performance using the preplanned multidirectional Australian football league agility test.

PubMed

Hart, Nicolas H; Spiteri, Tania; Lockie, Robert G; Nimphius, Sophia; Newton, Robert U

2014-12-01

The Australian Football League (AFL) agility test is a preplanned multidirectional circuit involving 5 directional changes of various magnitudes that might differently assess athletes of particular leg dominance. This study served to establish whether the AFL agility test appropriately examines athletes of differing limb dominance, while also quantifying performance deficits prevalent between limbs of Australian Footballers. Fifty-eight Australian Footballers were recruited from the Western Australian Football League (age = 21.9 ± 2.8 years; height = 183.7 ± 5.9 cm; weight = 86.4 ± 4.7 kg). Two circuits of the AFL agility test were set up in accordance with official specifications. The finish line of the second circuit was relocated to the opposite side to modify the starting direction. Footballers were randomized and counterbalanced between versions, performing 3 trials in each direction. Paired t-tests (p ≤ 0.05) were used to examine differences between dominant and nondominant trials. Independent t-tests (p ≤ 0.05) were used to identify differences between left and right leg dominant groups. The current version of the AFL agility test appropriately examined ∼61% of footballers in this cohort. The remaining ∼39% produced significantly faster times during the alternate version (0.63-0.82 seconds; p ≤ 0.001). All footballers demonstrated a performance deficit of 5-10% between limbs (∼0.72 seconds; p ≤ 0.001). Limb dominance (directional preference) was evident for all footballers. Change of direction capabilities should therefore be examined bilaterally to eliminate bias toward athletes with particular leg dominance profiles and to provide a limb deficit measure for enhanced athletic profiling outcomes.

Comparison of two progressive treadmill tests in patients with peripheral arterial disease.

PubMed

Riebe, D; Patterson, R B; Braun, C M

2001-11-01

In a vascular rehabilitation program, 28% of our frail elderly patients are unable to be tested with traditional progressive exercise protocols at program entry due to the high (2.0 miles/h or 3.2 km/h) initial treadmill speeds. The purpose of this investigation was to compare a new progressive treadmill protocol which has a reduced initial speed (1.0 mile/h or 1.6 km/h) to an established protocol performed at 2.0 miles/h (3.2 km/h) to determine the comparability and reproducibility of the new protocol. Eleven patients with arterial claudication performed three symptom-limited exercise tests in random order. Two tests used the new protocol while the remaining trial used the established protocol. Claudication pain was measured using a 5-point scale. Oxygen consumption, heart rate, minute ventilation, respiratory exchange ratio and blood pressure at peak exercise were similar among the three trials. There were strong intraclass correlations for peak oxygen consumption (r = 0.97), onset of claudication (r = 0.96) and maximum walking time (r = 0.98) between the two trials using the new protocol. There was also a significant correlation between the new protocol and the established protocol for peak oxygen consumption (r = 0.90) and maximum walking time (r = 0.89). The new progressive treadmill protocol represents a valid, reliable protocol for patients with arterial claudication. This protocol may be useful for testing patients with a low functional capacity so that clinically appropriate exercise prescriptions can be established and the efficacy of treatments can be determined.

Predicting High-Power Performance in Professional Cyclists.

PubMed

Sanders, Dajo; Heijboer, Mathieu; Akubat, Ibrahim; Meijer, Kenneth; Hesselink, Matthijs K

2017-03-01

To assess if short-duration (5 to ~300 s) high-power performance can accurately be predicted using the anaerobic power reserve (APR) model in professional cyclists. Data from 4 professional cyclists from a World Tour cycling team were used. Using the maximal aerobic power, sprint peak power output, and an exponential constant describing the decrement in power over time, a power-duration relationship was established for each participant. To test the predictive accuracy of the model, several all-out field trials of different durations were performed by each cyclist. The power output achieved during the all-out trials was compared with the predicted power output by the APR model. The power output predicted by the model showed very large to nearly perfect correlations to the actual power output obtained during the all-out trials for each cyclist (r = .88 ± .21, .92 ± .17, .95 ± .13, and .97 ± .09). Power output during the all-out trials remained within an average of 6.6% (53 W) of the predicted power output by the model. This preliminary pilot study presents 4 case studies on the applicability of the APR model in professional cyclists using a field-based approach. The decrement in all-out performance during high-intensity exercise seems to conform to a general relationship with a single exponential-decay model describing the decrement in power vs increasing duration. These results are in line with previous studies using the APR model to predict performance during brief all-out trials. Future research should evaluate the APR model with a larger sample size of elite cyclists.

An open-label randomized-controlled trial of low dose aspirin with an early screening test for pre-eclampsia and growth restriction (TEST): Trial protocol.

PubMed

Mone, Fionnuala; Mulcahy, Cecilia; McParland, Peter; Stanton, Alice; Culliton, Marie; Downey, Paul; McCormack, Dorothy; Tully, Elizabeth; Dicker, Patrick; Breathnach, Fionnuala; Malone, Fergal D; McAuliffe, Fionnuala M

2016-07-01

Pre-eclampsia remains a worldwide cause of maternal and perinatal morbidity and mortality. Low dose aspirin (LDA) can reduce the occurrence of pre-eclampsia in women with identifiable risk factors. Emerging screening tests can determine the maternal risk of developing placental disease, such as pre-eclampsia from the first trimester of pregnancy. The aim of this study is to determine if it is more beneficial in terms of efficacy and acceptability to routinely prescribe LDA to nulliparous low-risk women compared to test indicated LDA on the basis of a positive screening test for placental disease. We propose a three armed multi-center open-labeled randomized control trial of; (i) routine LDA, (ii) no aspirin, and (iii) LDA on the basis of a positive first trimester pre-eclampsia screening test. LDA (75mg once daily) shall be given from the first trimester until 36-week gestation. The primary outcome measures include; (i) the proportion of eligible women that agree to participate (acceptability), (ii) compliance with study protocol (acceptability and feasibility), (iii) the proportion of women in whom it is possible to obtain first trimester trans-abdominal uterine artery Doppler examination (feasibility) and (iv) the proportion of women with a completed screening test that are issued the screening result within one week of having the test performed (feasibility). This will be the first clinical trial to determine the efficacy and acceptability in low-risk women of taking routine LDA versus no aspirin versus LDA based on a positive first trimester screening test for the prevention of placental disease. Copyright © 2016 Elsevier Inc. All rights reserved.

In Silico Evaluation of Pharmacokinetic Optimization for Antimitogram-Based Clinical Trials.

PubMed

Haviari, Skerdi; You, Benoît; Tod, Michel

2018-04-01

Antimitograms are prototype in vitro tests for evaluating chemotherapeutic efficacy using patient-derived primary cancer cells. These tests might help optimize treatment from a pharmacodynamic standpoint by guiding treatment selection. However, they are technically challenging and require refinements and trials to demonstrate benefit to be widely used. In this study, we performed simulations aimed at exploring how to validate antimitograms and how to complement them by pharmacokinetic optimization. A generic model of advanced cancer, including pharmacokinetic-pharmacodynamic monitoring, was used to link dosing schedules with progression-free survival (PFS), as built from previously validated modules. This model was used to explore different possible situations in terms of pharmacokinetic variability, pharmacodynamic variability, and antimitogram performance. The model recapitulated tumor dynamics and standalone therapeutic drug monitoring efficacy consistent with published clinical results. Simulations showed that combining pharmacokinetic and pharmacodynamic optimization should increase PFS in a synergistic fashion. Simulated data were then used to compute required clinical trial sizes, which were 30% to 90% smaller when pharmacokinetic optimization was added to pharmacodynamic optimization. This improvement was observed even when pharmacokinetic optimization alone exhibited only modest benefit. Overall, our work illustrates the synergy derived from combining antimitograms with therapeutic drug monitoring, permitting a disproportionate reduction of the trial size required to prove a benefit on PFS. Accordingly, we suggest that strategies with benefits too small for standalone clinical trials could be validated in combination in a similar manner. Significance: This work offers a method to reduce the number of patients needed for a clinical trial to prove the hypothesized benefit of a drug to progression-free survival, possibly easing opportunities to evaluate combinations. Cancer Res; 78(7); 1873-82. ©2018 AACR . ©2018 American Association for Cancer Research.

Emotional Recognition in Autism Spectrum Conditions from Voices and Faces

ERIC Educational Resources Information Center

Stewart, Mary E.; McAdam, Clair; Ota, Mitsuhiko; Peppe, Sue; Cleland, Joanne

2013-01-01

The present study reports on a new vocal emotion recognition task and assesses whether people with autism spectrum conditions (ASC) perform differently from typically developed individuals on tests of emotional identification from both the face and the voice. The new test of vocal emotion contained trials in which the vocal emotion of the sentence…

Three Chronometric Indices of Relational Responding as Predictors of Performance on a Brief Intelligence Test: The Importance of Relational Flexibility

ERIC Educational Resources Information Center

O'Toole, Catriona; Barnes-Holmes, Dermot

2009-01-01

Participants completed a before/after and a similar/different relational task, using the Implicit Relational Assessment Procedure (IRAP), and subsequently took the Kaufman Brief Intelligence Test (K-BIT). For each relational task, response latencies were measured first on consistent trials, where participants responded in accordance with…

The Postoperative Pain Assessment Skills pilot trial.

PubMed

McGillion, Michael; Dubrowski, Adam; Stremler, Robyn; Watt-Watson, Judy; Campbell, Fiona; McCartney, Colin; Victor, Charles; Wiseman, Jeffrey; Snell, Linda; Costello, Judy; Robb, Anja; Nelson, Sioban; Stinson, Jennifer; Hunter, Judith; Dao, Thuan; Promislow, Sara; McNaughton, Nancy; White, Scott; Shobbrook, Cindy; Jeffs, Lianne; Mauch, Kianda; Leegaard, Marit; Beattie, W Scott; Schreiber, Martin; Silver, Ivan

2011-01-01

BACKGROUND⁄ Pain-related misbeliefs among health care professionals (HCPs) are common and contribute to ineffective postoperative pain assessment. While standardized patients (SPs) have been effectively used to improve HCPs' assessment skills, not all centres have SP programs. The present equivalence randomized controlled pilot trial examined the efficacy of an alternative simulation method - deteriorating patient-based simulation (DPS) - versus SPs for improving HCPs' pain knowledge and assessment skills. Seventy-two HCPs were randomly assigned to a 3 h SP or DPS simulation intervention. Measures were recorded at baseline, immediate postintervention and two months postintervention. The primary outcome was HCPs' pain assessment performance as measured by the postoperative Pain Assessment Skills Tool (PAST). Secondary outcomes included HCPs knowledge of pain-related misbeliefs, and perceived satisfaction and quality of the simulation. These outcomes were measured by the Pain Beliefs Scale (PBS), the Satisfaction with Simulated Learning Scale (SSLS) and the Simulation Design Scale (SDS), respectively. Student's t tests were used to test for overall group differences in postintervention PAST, SSLS and SDS scores. One-way analysis of covariance tested for overall group differences in PBS scores. DPS and SP groups did not differ on post-test PAST, SSLS or SDS scores. Knowledge of pain-related misbeliefs was also similar between groups. These pilot data suggest that DPS is an effective simulation alternative for HCPs' education on postoperative pain assessment, with improvements in performance and knowledge comparable with SP-based simulation. An equivalence trial to examine the effectiveness of deteriorating patient-based simulation versus standardized patients is warranted.

[Challenges in the organization of investigator initiated trials: in transplantation medicine].

PubMed

Schnitzbauer, A A; Lamby, P E; Mutzbauer, I; von Hassel, J; Geissler, E K; Schlitt, H J

2011-03-01

Transplantation medicine offers multiple translational questions which should preferably be transferred to clinical evidence. The current gold standard for testing such questions and hypotheses is by prospective randomized controlled trials (RCT). The trials should be performed independently from the medical industry to avoid conflicts of interests and to guarantee a strict scientific approach. A good model is an investigator initiated trial (IIT) in which academic institutions function as the sponsor and in which normally a scientific idea stands before marketing interests of a certain medical product. We present a model for an IIT which is sponsored and coordinated by Regensburg University Hospital at 45 sites in 13 nations (SiLVER study), highlight special pitfalls of this study and offer alternatives to this approach. Finances: financial support in clinical trials can be obtained from the medical industry. Alternatively in Germany the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung) offers annual grants. The expansion of financial support through foundations is desirable. Infrastructure: sponsorship within the pharmaceutics act (Arzneimittelgesetz) demands excellent infrastructural conditions and a professional team to accomplish clinical, logistic, regulatory, legal and ethical challenges in a RCT. If a large trial has sufficient financial support certain tasks can be outsourced and delegated to contract research organizations, coordinating centers for clinical trials or partners in the medical industry. Clinical scientific advances to improve evidence are an enormous challenge when performed as an IIT. However, academic sponsors can perform (international) IITs when certain rules are followed and should be defined as the gold standard when scientific findings have to be established clinically.

Static performance tests of a flight-type STOVL ejector

NASA Technical Reports Server (NTRS)

Barankiewicz, Wendy S.

1991-01-01

The design and development of thrust augmenting STOVL ejectors has typically been based on experimental iteration (i.e., trial and error). Static performance tests of a full scale vertical lift ejector were performed at primary flow temperatures up to 1560 R (1100 F). Flow visualization (smoke generators and yarn tufts) were used to view the inlet air flow, especially around the primary nozzle and end plates. Performance calculations are presented for ambient temperatures close to 480 R (20 F) and 535 R (75 F) which simulate seasonal aircraft operating conditions. Resulting thrust augmentation ratios are presented as functions of nozzle pressure ratio and temperature.

External Control of Knowledge of Results: Learner Involvement Enhances Motor Skill Transfer.

PubMed

Figueiredo, L S; Ugrinowitsch, H; Freire, A B; Shea, J B; Benda, R N

2018-04-01

Providing the learner control over aspects of practice has improved the process of motor skill acquisition, and self-controlled knowledge of results (KR) schedules have shown specific advantages over externally controlled ones. A possible explanation is that self-controlled KR schedules lead learners to more active task involvement, permitting deeper information processing. This study tested this explanatory hypothesis. Thirty undergraduate volunteers of both sexes, aged 18 to 35, all novices in the task, practiced transporting a tennis ball in a specified sequence within a time goal. We compared a high-involvement group (involvement yoked, IY), notified in advance about upcoming KR trials, to self-controlled KR (SC) and yoked KR (YK) groups. The experiment consisted of three phases: acquisition, retention, and transfer. We found both IY and SC groups to be superior to YK for transfer of learning. Postexperiment participant questionnaires confirmed a preference for receiving KR after learner-perceived good trials, even though performance on those trials did not differ from performance on trials without KR. Equivalent IY and SC performances provide support for the benefits of task involvement and deeper information processing when KR is self-controlled in motor skill acquisition.

Reliability of sprint test indices in well-trained cyclists.

PubMed

Coleman, D A; Wiles, J D; Nunn, M; Smith, M F

2005-06-01

The study aim was to assess reliability of repeated laboratory sprint tests in well-trained endurance cyclists. Eleven male cyclists (mean +/- standard deviation: 27 +/- 6 yr, 1.79 +/- 0.04 m, 70.1 +/- 3.3 kg) performed a maximal 30-second sprint test on four separate occasions using their own bicycle fitted with an SRM powermeter on a Kingcycle air-braked ergometer. Peak power output (W (peak)), mean power (W (mean)) and an index of fatigue (FI) were calculated. Three minutes post sprint, capillarised blood lactate measurements were taken and analysed. No significant differences (p > 0.05) were found between trials for W (peak), W (mean), FI and blood lactate concentration. Repeatability of W (peak), W (mean), and fatigue index improved across trials 2 and 3 when compared to trials 1 and 2. The highest CV for these variables was recorded between trials 3 and 4. The CV for W (peak) was 4.5 +/- 1.6 %, W (mean) 2.4 +/- 1.2 %, and FI 17.2 +/- 7.1 %. Intraclass reliability coefficients were 0.93 (95 % CI 0.84 - 0.98), 0.94 (95 % CI 0.86 - 0.98) and 0.89 (95 % CI 0.69 - 0.95) respectively. Blood lactate concentration ranged between 5.35 and 14.52 mmol.l(-1), with a mean CV of 12.1 +/- 4.2 %. The CV for trials 2 and 3 revealed the highest CV for blood lactate concentration (15.1 %). The lowest CV for this variable (10.2 %) was recorded between trials 3 and 4. The intraclass reliability coefficient for blood lactate concentration was 0.79 (95 % CI 0.58 - 0.93). The results of this study indicate that there is no improvement in the reliability of sprint test indices when assessing well-trained, experienced cyclists, riding on their own cycle equipment.

Effects of Post-Exercise Honey Drink Ingestion on Blood Glucose and Subsequent Running Performance in the Heat

PubMed Central

Ahmad, Nur Syamsina; Ooi, Foong Kiew; Saat Ismail, Mohammed; Mohamed, Mahaneem

2015-01-01

Background: Glycogen depletion and hypoglycemia have been associated with fatigue and decrement of performance during prolonged exercise Objectives: This study investigated the effectiveness of Acacia honey drink as a post-exercise recovery aid on glucose metabolism and subsequent running performance in the heat. Patients and Methods: Ten subjects participated in this randomized cross-over study. All subjects performed 2 trials. In each trial, all subjects went through a glycogen depletion phase (Run-1), 2-hour rehydration phase and time trial running phase (Run-2). In Run-1, subjects were required to run on a treadmill at 65% VO2max in the heat (31°C, 70% relative humidity) for 60 min. During 2-hour rehydration phase, subjects drank either plain water (PW) or honey drink (HD) with amount equivalent to 150% of body weight loss in 3 boluses (60%, 50% and 40% subsequently) at 0, 30 and 60 min. In Run-2, the longest distance covered in 20 min was recorded for determining running performance. Two-way repeated measured ANOVA and paired t-test were used for analysis. Results: Running distance in Run-2 covered by the subjects in the honey drink HD trial (3420 ± 350 m) was significantly (P < 0.01) longer compared to plain water PW trial (3120 ± 340 m). In general, plasma glucose, serum insulin and osmolality were significantly (P < 0.05) higher in HD compared to PW during the rehydration phase and Run-2. Conclusions: These findings indicate that rehydration with honey drink improves running performance and glucose metabolism compared to plain water in the heat. Thus, honey drink can be recommended for rehydration purpose for athletes who compete in the heat. PMID:26448850

Assessing mNIS+7Ionis and international neurologists' proficiency in a familial amyloidotic polyneuropathy trial.

PubMed

Dyck, Peter J; Kincaid, John C; Dyck, P James B; Chaudhry, Vinay; Goyal, Namita A; Alves, Christina; Salhi, Hayet; Wiesman, Janice F; Labeyrie, Celine; Robinson-Papp, Jessica; Cardoso, Márcio; Laura, Matilde; Ruzhansky, Katherine; Cortese, Andrea; Brannagan, Thomas H; Khoury, Julie; Khella, Sami; Waddington-Cruz, Márcia; Ferreira, João; Wang, Annabel K; Pinto, Marcus V; Ayache, Samar S; Benson, Merrill D; Berk, John L; Coelho, Teresa; Polydefkis, Michael; Gorevic, Peter; Adams, David H; Plante-Bordeneuve, Violaine; Whelan, Carol; Merlini, Giampaolo; Heitner, Stephen; Drachman, Brian M; Conceição, Isabel; Klein, Christopher J; Gertz, Morie A; Ackermann, Elizabeth J; Hughes, Steven G; Mauermann, Michelle L; Bergemann, Rito; Lodermeier, Karen A; Davies, Jenny L; Carter, Rickey E; Litchy, William J

2017-11-01

Polyneuropathy signs (Neuropathy Impairment Score, NIS), neurophysiologic tests (m+7 Ionis ), disability, and health scores were assessed in baseline evaluations of 100 patients entered into an oligonucleotide familial amyloidotic polyneuropathy (FAP) trial. We assessed: (1) Proficiency of grading neurologic signs and correlation with neurophysiologic tests, and (2) clinometric performance of modified NIS+7 neurophysiologic tests (mNIS+7 Ionis ) and its subscores and correlation with disability and health scores. The mNIS+7 Ionis sensitively detected, characterized, and broadly scaled diverse polyneuropathy impairments. Polyneuropathy signs (NIS and subscores) correlated with neurophysiology tests, disability, and health scores. Smart Somatotopic Quantitative Sensation Testing of heat as pain 5 provided a needed measure of small fiber involvement not adequately assessed by other tests. Specially trained neurologists accurately assessed neuropathy signs as compared to referenced neurophysiologic tests. The score, mNIS+7 Ionis , broadly detected, characterized, and scaled polyneuropathy abnormality in FAP, which correlated with disability and health scores. Muscle Nerve 56: 901-911, 2017. © 2017 Wiley Periodicals, Inc.

Reliability and Repetition Effect of the Center of Pressure and Kinematics Parameters That Characterize Trunk Postural Control During Unstable Sitting Test.

PubMed

Barbado, David; Moreside, Janice; Vera-Garcia, Francisco J

2017-03-01

Although unstable seat methodology has been used to assess trunk postural control, the reliability of the variables that characterize it remains unclear. To analyze reliability and learning effect of center of pressure (COP) and kinematic parameters that characterize trunk postural control performance in unstable seating. The relationships between kinematic and COP parameters also were explored. Test-retest reliability design. Biomechanics laboratory setting. Twenty-three healthy male subjects. Participants volunteered to perform 3 sessions at 1-week intervals, each consisting of five 70-second balancing trials. A force platform and a motion capture system were used to measure COP and pelvis, thorax, and spine displacements. Reliability was assessed through standard error of measurement (SEM) and intraclass correlation coefficients (ICC 2,1 ) using 3 methods: (1) comparing the last trial score of each day; (2) comparing the best trial score of each day; and (3) calculating the average of the three last trial scores of each day. Standard deviation and mean velocity were calculated to assess balance performance. Although analyses of variance showed some differences in balance performance between days, these differences were not significant between days 2 and 3. Best result and average methods showed the greatest reliability. Mean velocity of the COP showed high reliability (0.71 < ICC < 0.86; 10.3 < SEM < 13.0), whereas standard deviation only showed a low to moderate reliability (0.37 < ICC < 0.61; 14.5 < SEM < 23.0). Regarding the kinematic variables, only pelvis displacement mean velocity achieved a high reliability using the average method (0.62 < ICC < 0.83; 18.8 < SEM < 23.1). Correlations between COP and kinematics were high only for mean velocity (0.45

Effect of e-learning and repeated performance feedback on spirometry test quality in family practice: a cluster trial.

PubMed

Schermer, Tjard R; Akkermans, Reinier P; Crockett, Alan J; van Montfort, Marian; Grootens-Stekelenburg, Joke; Stout, Jim W; Pieters, Willem

2011-01-01

Spirometry has become an indispensable tool in primary care to exclude, diagnose, and monitor chronic respiratory conditions, but the quality of spirometry tests in family practices is a reason for concern. Aim of this study was to investigate whether a combination of e-learning and bimonthly performance feedback would improve spirometry test quality in family practices in the course of 1 year. Our study was a cluster trial with 19 family practices allocated to intervention or control conditions through minimization. Intervention consisted of e-learning and bimonthly feedback reports to practice nurses. Control practices received only the joint baseline workshop. Spirometry quality was assessed by independent lung function technicians. Two outcomes were defined, with the difference between rates of tests with 2 acceptable and repeatable blows being the primary outcome and the difference between rates of tests with 2 acceptable blows being the secondary outcome. We used multilevel logistic regression analysis to calculate odds ratios (ORs) for an adequate test in intervention group practices. We analyzed 1,135 tests. Rate of adequate tests was 33% in intervention and 30% in control group practices (OR = 1.3; P=.605). Adequacy of tests did not differ between groups but tended to increase with time: OR = 2.2 (P = .057) after 3 and OR = 2.0 (P = .086) in intervention group practices after 4 feedback reports. When ignoring test repeatability, these differences between the groups were slightly more pronounced: OR = 2.4 (P = .033) after 3 and OR=2.2 (P = .051) after 4 feedback reports. In the course of 1 year, we observed a small and late effect of e-learning and repeated feedback on the quality of spirometry as performed by family practice nurses. This intervention does not seem to compensate the lack of rigorous training and experience in performing spirometry tests in most practices.

Opt-out screening strategy for HIV infection among patients attending emergency departments: systematic review and meta-analysis.

PubMed

Henriquez-Camacho, C; Villafuerte-Gutierrez, P; Pérez-Molina, J A; Losa, J; Gotuzzo, E; Cheyne, N

2017-07-01

International health agencies have promoted nontargeted universal (opt-out) HIV screening tests in different settings, including emergency departments (EDs). We performed a systematic review and meta-analysis to assess the testing uptake of strategies (opt-in targeted, opt-in nontargeted and opt-out) to detect new cases of HIV infection in EDs. We searched the Pubmed and Embase databases, from 1984 to April 2015, for opt-in and opt-out HIV diagnostic strategies used in EDs. Randomized controlled or quasi experimental studies were included. We assessed the percentage of positive individuals tested for HIV infection in each programme (opt-in and opt-out strategies). The mean percentage was estimated by combining studies in a random-effect meta-analysis. The percentages of individuals tested in the programmes were compared in a random-effect meta-regression model. Data were analysed using stata version 12. Quality assessments were performed using the Newcastle-Ottawa Scale. Of the 90 papers identified, 28 were eligible for inclusion. Eight trials used opt-out, 18 trials used opt-in, and two trials used both to detect new cases of HIV infection. The test was accepted and taken by 75 155 of 172 237 patients (44%) in the opt-out strategy, and 73 581 of 382 992 patients (19%) in the opt-in strategy. The prevalence of HIV infection detected by the opt-out strategy was 0.40% (373 cases), that detected by the opt-in nontargeted strategy was 0.52% (419 cases), and that detected by the opt-in targeted strategy was 1.06% (52 cases). In this meta-analysis, the testing uptake of the opt-out strategy was not different from that of the opt-in strategy to detect new cases of HIV infection in EDs. © 2016 British HIV Association.

The effect on physical performance of a functional assessment and immediate rehabilitation of acutely admitted elderly patients with reduced functional performance: the design of a randomised clinical trial

PubMed Central

Bruun, Inge Hansen; Nørgaard, Birgitte; Maribo, Thomas; Schiøttz-Christensen, Berit; Mogensen, Christian Backer

2014-01-01

Introduction Illness and hospitalisation, even of short duration, pose separate risks for permanently reduced functional performance in elderly medical patients. Functional assessment in the acute pathway will ensure early detection of declining performance and form the basis for mobilisation during hospitalisation and subsequent rehabilitation. For optimal results rehabilitation should begin immediately after discharge.The aim of this study is to investigate the effect of a systematic functional assessment in the emergency department (ED) of elderly medical patients with reduced functional performance when combined with immediate postdischarge rehabilitation. Method and analysis The study is a two-way factorial randomised clinical trial. Participants will be recruited among patients admitted to the ED who are above 65 years of age with reduced functional performance. Patients will be randomly assigned to one of four groups: (1) functional assessment and immediate rehabilitation; (2) functional assessment and rehabilitation as usual; (3) assessment as usual and immediate rehabilitation; (4) assessment and rehabilitation as usual. Primary outcome 30 s chair-stand test administered at admission and 3 weeks after discharge. Ethics and dissemination The study has been approved by the Regional Scientific Ethical Committees of Southern Denmark in February 2014. The study findings will be published in peer-reviewed journals and presented at national and international conferences. Trial registration number: ClinicalTrials.gov Identifier: NCT02062541. PMID:24939812

Dynamic functional connectivity shapes individual differences in associative learning.

PubMed

Fatima, Zainab; Kovacevic, Natasha; Misic, Bratislav; McIntosh, Anthony Randal

2016-11-01

Current neuroscientific research has shown that the brain reconfigures its functional interactions at multiple timescales. Here, we sought to link transient changes in functional brain networks to individual differences in behavioral and cognitive performance by using an active learning paradigm. Participants learned associations between pairs of unrelated visual stimuli by using feedback. Interindividual behavioral variability was quantified with a learning rate measure. By using a multivariate statistical framework (partial least squares), we identified patterns of network organization across multiple temporal scales (within a trial, millisecond; across a learning session, minute) and linked these to the rate of change in behavioral performance (fast and slow). Results indicated that posterior network connectivity was present early in the trial for fast, and later in the trial for slow performers. In contrast, connectivity in an associative memory network (frontal, striatal, and medial temporal regions) occurred later in the trial for fast, and earlier for slow performers. Time-dependent changes in the posterior network were correlated with visual/spatial scores obtained from independent neuropsychological assessments, with fast learners performing better on visual/spatial subtests. No relationship was found between functional connectivity dynamics in the memory network and visual/spatial test scores indicative of cognitive skill. By using a comprehensive set of measures (behavioral, cognitive, and neurophysiological), we report that individual variations in learning-related performance change are supported by differences in cognitive ability and time-sensitive connectivity in functional neural networks. Hum Brain Mapp 37:3911-3928, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Sequential responding and planning in capuchin monkeys (Cebus apella).

PubMed

Beran, Michael J; Parrish, Audrey E

2012-11-01

Previous experiments have assessed planning during sequential responding to computer generated stimuli by Old World nonhuman primates including chimpanzees and rhesus macaques. However, no such assessment has been made with a New World primate species. Capuchin monkeys (Cebus apella) are an interesting test case for assessing the distribution of cognitive processes in the Order Primates because they sometimes show proficiency in tasks also mastered by apes and Old World monkeys, but in other cases fail to match the proficiency of those other species. In two experiments, eight capuchin monkeys selected five arbitrary stimuli in distinct locations on a computer monitor in a learned sequence. In Experiment 1, shift trials occurred in which the second and third stimuli were transposed when the first stimulus was selected by the animal. In Experiment 2, mask trials occurred in which all remaining stimuli were masked after the monkey selected the first stimulus. Monkeys made more mistakes on trials in which the locations of the second and third stimuli were interchanged than on trials in which locations were not interchanged, suggesting they had already planned to select a location that no longer contained the correct stimulus. When mask trials occurred, monkeys performed at levels significantly better than chance, but their performance exceeded chance levels only for the first and the second selections on a trial. These data indicate that capuchin monkeys performed very similarly to chimpanzees and rhesus monkeys and appeared to plan their selection sequences during the computerized task, but only to a limited degree.

Impact of cafeteria feeding during lactation in the rat on novel object discrimination in the offspring.

PubMed

Wright, Thomas M; King, Madeleine V; Davey, William G; Langley-Evans, Simon C; Voigt, Jörg-Peter W

2014-12-28

There is increasing evidence that hyperenergetic diets have an impact on memory in rodents. However, it is largely unknown how diets, such as a cafeteria diet (CD), that mimic a Western-type diet act on learning and memory, in particular when fed during early stages of development. Here, we fed lactating dams a CD and exposed both male and female offspring to a novel object discrimination (NOD) task, a two-trial test of recognition memory in which rats exposed to two identical objects during a training/familiarisation trial can discriminate a novel from a familiar object during the subsequent choice trial. The choice trial was performed following inter-trial interval (ITI) delays of up to 4 h. Maternal diet did not have an impact on exploration of the objects by either sex during the familiarisation trial. Control males discriminated the novel from the familiar object, indicating intact memory with an ITI of 1 h, but not 2 or 4 h. The CD delayed this natural forgetting in male rats such that discrimination was also evident after a 2 h ITI. In contrast, control females exhibited discrimination following both 1 and 2 h ITI, but the CD impaired performance. In summary, the present study shows that maternal exposure to the CD programmes NOD in the adult. In better-performing females, dietary programming interferes with NOD, whereas NOD was improved in males after lactational CD feeding.

Effects of overtraining on extinction in newts (Cynops pyrrhogaster).

PubMed

Shibasaki, Masahiro; Ishida, Masato

2012-11-01

The overtraining extinction effect (OEE), a phenomenon in which extended training facilitates extinction, has been found in mammals and reptiles. However, fish have never shown OEE. No study has yet investigated OEE in newts, a representative amphibian species. We tested whether newts, Cynops pyrrhogaster, show OEE in a straight-array task. All animals received five trials per day and were given a piece of dried worm during reinforced trials. They showed significant acquisition and extinction effects in reinforced and nonreinforced trials. However, we found no difference in extinction performance between a group with 25-trial acquisition and one with 75-trial acquisition, suggesting that OEE was not found in newts. OEE has generally been explained in terms of frustration-related mechanisms. Our results suggest that emotional reactions to nonreward, such as frustration, may not influence behavior in amphibians.

The Acute and Residual Effect of a Single Exercise Session on Meal Glucose Tolerance in Sedentary Young Adults

PubMed Central

Short, Kevin R.; Pratt, Lauren V.; Teague, April M.

2012-01-01

The study goals were to (1) establish the variability in postprandial glucose control in healthy young people consuming a mixed meal and, then (2) determine the acute and residual impact of a single exercise bout on postprandial glucose control. In study 1, 18 people completed two similar mixed meal trials and an intravenous glucose tolerance test (IVGTT). There were strong test-retest correlations for the post-meal area under the curve (AUC) for glucose, insulin, and Cpeptide (r = 0.73–0.83) and the Matsuda insulin sensitivity index (ISI, r = 0.76), and between meal and IVGTT-derived ISI (r = 0.83). In study 2, 11 untrained young adults completed 3 trials. One trial (No Ex) was completed after refraining from vigorous activity for ≥3 days. On the other 2 trials, a 45-min aerobic exercise bout was performed either 17-hours (Prior Day Ex) or 1-hour (Same Day Ex) before consuming the test meal. Compared to No Ex and Prior Day Ex, which did not differ from one another, there were lower AUCs on the Same Day Ex trial for glucose (6%), insulin (20%) and C-peptide (14%). Thus, a single moderate intensity exercise session can acutely improve glycemic control but the effect is modest and short-lived. PMID:22666560

Metabolic and exercise endurance effects of coffee and caffeine ingestion.

PubMed

Graham, T E; Hibbert, E; Sathasivam, P

1998-09-01

Caffeine (Caf) ingestion increases plasma epinephrine (Epi) and exercise endurance; these results are frequently transferred to coffee (Cof) consumption. We examined the impact of ingestion of the same dose of Caf in Cof or in water. Nine healthy, fit, young adults performed five trials after ingesting (double blind) either a capsule (Caf or placebo) with water or Cof (decaffeinated Cof, decaffeinated with Caf added, or regular Cof). In all three Caf trials, the Caf dose was 4.45 mg/kg body wt and the volume of liquid was 7.15 ml/kg. After 1 h of rest, the subject ran at 85% of maximal O2 consumption until voluntary exhaustion (approximately 32 min in the placebo and decaffeinated Cof tests). In the three Caf trials, the plasma Caf and paraxanthine concentrations were very similar. After 1 h of rest, the plasma Epi was increased (P < 0.05) by Caf ingestion, but the increase was greater (P < 0.05) with Caf capsules than with Cof. During the exercise there were no differences in Epi among the three Caf trials, and the Epi values were all greater (P < 0.05) than in the other tests. Endurance was only increased (P < 0. 05) in the Caf capsule trial; there were no differences among the other four tests. One cannot extrapolate the effects of Caf to Cof; there must be a component(s) of Cof that moderates the actions of Caf.

Selective Attention Deficits Associated with Mild Cognitive Impairment and Early Stage Alzheimer's Disease in Adults with Down Syndrome

ERIC Educational Resources Information Center

Krinsky-McHale, Sharon J.; Devenny, Darlynne A.; Kittler, Phyllis; Silverman, Wayne

2008-01-01

Adults with Down syndrome and early stage Alzheimer's disease showed decline in their ability to selectively attend to stimuli in a multitrial cancellation task. They also showed variability in their performance over the test trials, whereas healthy participants showed stability. These changes in performance were observed approximately 2 years…

The DIAN-TU Next Generation Alzheimer's prevention trial: Adaptive design and disease progression model.

PubMed

Bateman, Randall J; Benzinger, Tammie L; Berry, Scott; Clifford, David B; Duggan, Cynthia; Fagan, Anne M; Fanning, Kathleen; Farlow, Martin R; Hassenstab, Jason; McDade, Eric M; Mills, Susan; Paumier, Katrina; Quintana, Melanie; Salloway, Stephen P; Santacruz, Anna; Schneider, Lon S; Wang, Guoqiao; Xiong, Chengjie

2017-01-01

The Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU) trial is an adaptive platform trial testing multiple drugs to slow or prevent the progression of Alzheimer's disease in autosomal dominant Alzheimer's disease (ADAD) families. With completion of enrollment of the first two drug arms, the DIAN-TU now plans to add new drugs to the platform, designated as the Next Generation (NexGen) prevention trial. In collaboration with ADAD families, philanthropic organizations, academic leaders, the DIAN-TU Pharma Consortium, the National Institutes of Health, and regulatory colleagues, the DIAN-TU developed innovative clinical study designs for the DIAN-TU NexGen prevention trial. Our expanded trial toolbox consists of a disease progression model for ADAD, primary end point DIAN-TU cognitive performance composite, biomarker development, self-administered cognitive assessments, adaptive dose adjustments, and blinded data collection through the last participant completion. These steps represent elements to improve efficacy of the adaptive platform trial and a continued effort to optimize prevention and treatment trials in ADAD. Copyright © 2016 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

[Psychological results of mental performance in sleep deprivation].

PubMed

Dahms, P; Schaad, G; Gorges, W; von Restorff, W

1996-01-01

To quantify the effects of sleep periods that have different lengths of time during continuous operations (CONOPS) 2 independent groups of subjects performed several cognitive tasks for 3 days. The 72 h trial period contained three 60-min sleep periods for the 10 subjects of the experimental group and three sleep periods of 4 h each for the 14 subjects of the control group. With the exception of only one subtest the statistical analyses of the test results of the 2 groups show no significant differences in cognitive performance. It is suggested that high motivation is responsible for comparable performance of the subjects, which was essentially obtained by a monetary pay system for successful test performance.

A Bayesian adaptive design for biomarker trials with linked treatments

PubMed Central

Wason, James M S; Abraham, Jean E; Baird, Richard D; Gournaris, Ioannis; Vallier, Anne-Laure; Brenton, James D; Earl, Helena M; Mander, Adrian P

2015-01-01

Background: Response to treatments is highly heterogeneous in cancer. Increased availability of biomarkers and targeted treatments has led to the need for trial designs that efficiently test new treatments in biomarker-stratified patient subgroups. Methods: We propose a novel Bayesian adaptive randomisation (BAR) design for use in multi-arm phase II trials where biomarkers exist that are potentially predictive of a linked treatment's effect. The design is motivated in part by two phase II trials that are currently in development. The design starts by randomising patients to the control treatment or to experimental treatments that the biomarker profile suggests should be active. At interim analyses, data from treated patients are used to update the allocation probabilities. If the linked treatments are effective, the allocation remains high; if ineffective, the allocation changes over the course of the trial to unlinked treatments that are more effective. Results: Our proposed design has high power to detect treatment effects if the pairings of treatment with biomarker are correct, but also performs well when alternative pairings are true. The design is consistently more powerful than parallel-groups stratified trials. Conclusions: This BAR design is a powerful approach to use when there are pairings of biomarkers with treatments available for testing simultaneously. PMID:26263479

Update on Clinical Trials in Dry Age-related Macular Degeneration

PubMed Central

Taskintuna, Ibrahim; Elsayed, M. E. A. Abdalla; Schatz, Patrik

2016-01-01

This review article summarizes the most recent clinical trials for dry age-related macular degeneration (AMD), the most common cause of vision loss in the elderly in developed countries. A literature search through websites https://www.pubmed.org and https://www.clinicaltrials.gov/, both accessed no later than November 04, 2015, was performed. We identified three Phase III clinical trials that were completed over the recent 5 years Age-Related Eye Disease Study 2 (AREDS2), implantable miniature telescope and tandospirone, and several other trials targeting a variety of mechanisms including, oxidative stress, complement inhibition, visual cycle inhibition, retinal and choroidal blood flow, stem cells, gene therapy, and visual rehabilitation. To date, none of the biologically oriented therapies have resulted in improved vision. Vision improvement was reported with an implantable mini telescope. Stem cells therapy holds a potential for vision improvement. The AREDS2 formulas did not add any further reduced risk of progression to advanced AMD, compared to the original AREDS formula. Several recently discovered pathogenetic mechanisms in dry AMD have enabled development of new treatment strategies, and several of these have been tested in recent clinical trials and are currently being tested in ongoing trials. The rapid development and understanding of pathogenesis holds promise for the future. PMID:26957835

Atypical performance patterns on Delis-Kaplan Executive Functioning System Color-Word Interference Test: Cognitive switching and learning ability in older adults.

PubMed

Berg, Jody-Lynn; Swan, Natasha M; Banks, Sarah J; Miller, Justin B

2016-09-01

Cognitive set shifting requires flexible application of lower level processes. The Delis-Kaplan Executive Functioning System (DKEFS) Color-Word Interference Test (CWIT) is commonly used to clinically assess cognitive set shifting. An atypical pattern of performance has been observed on the CWIT; a subset of individuals perform faster, with equal or fewer errors, on the more difficult inhibition/switching than the inhibition trial. This study seeks to explore the cognitive underpinnings of this atypical pattern. It is hypothesized that atypical patterns on CWIT will be associated with better performance on underlying cognitive measures of attention, working memory, and learning when compared to typical CWIT patterns. Records from 239 clinical referrals (age: M = 68.09 years, SD = 10.62; education: M = 14.87 years, SD = 2.73) seen for a neuropsychological evaluation as part of diagnostic work up in an outpatient dementia and movement disorders clinic were sampled. The standard battery of tests included measures of attention, learning, fluency, executive functioning, and working memory. Analyses of variance (ANOVAs) were conducted to compare the cognitive performance of those with typical versus atypical CWIT patterns. An atypical pattern of performance was confirmed in 23% of our sample. Analyses revealed a significant group difference in acquisition of information on both nonverbal (Brief Visuospatial Memory Test-Revised, BVMT-R total recall), F(1, 213) = 16.61, p < .001, and verbal (Hopkins Verbal Learning Test-Revised, HVLT-R total recall) learning tasks, F(1, 181) = 6.43, p < .01, and semantic fluency (Animal Naming), F(1, 232) = 7.57, p = .006, with the atypical group performing better on each task. Effect sizes were larger for nonverbal (Cohen's d = 0.66) than verbal learning (Cohen's d = 0.47) and semantic fluency (Cohen's d = 0.43). Individuals demonstrating an atypical pattern of performance on the CWIT inhibition/switching trial also demonstrated relative strengths in semantic fluency and learning.

Time-trial Performance in World-Class Speed Skaters After Chronic Nitrate Ingestion.

PubMed

Richard, Philippe; Koziris, Lymperis P; Charbonneau, Mathieu; Naulleau, Catherine; Tremblay, Jonathan; Billaut, François

2018-05-10

Nitrate supplementation can increase tolerance to high-intensity work rates, however limited data exist on the recovery of performance. We tested whether 5 days of nitrate supplementation could improve repeated time-trial performance in speed skating. Using a double-blind, placebo-controlled, crossover design, 9 international-level short-track speed skaters ingested one high (juice blend, ~6.5mmol nitrate; HI) or low dose (juice blend, ~1mmol nitrate; LO) per day on days 1-4. After a double dose of either HI or LO on day 5, athletes performed two on-ice 1000-m time trials, separated by 35 min, to simulate competition races. Differences between HI and LO were compared to the smallest practically important difference. Salivary [nitrate] and [nitrite] were higher in HI than LO before the first (nitrate 81%, ES 1.76; nitrite 72%, ES 1.73) and second pursuits (nitrate 81%, ES 1.92; nitrite 71%, ES 1.78). However, there was no difference in performance in the first (LO: 90.92±4.08sec; HI: 90.95±4.06sec, ES 0.01) nor the second time-trial (LO: 91.16±4.06; HI: 91.55±4.40sec, ES 0.09). Plasma [lactate] measured after the trials (LO: 14.8±1.1mM; HI: 14.8±1.2mM, ES 0.01) and at the end of the recovery period (LO: 9.8±2.1mM; HI: 10.2±1.9mM, ES 0.05) was not different between treatments. Five days of a high-dose nitrate supplementation did not change physiological responses and failed to improve single and repeated time-trial performances in world-class short-track speed skaters. These data suggest that nitrate ingestion up to 6.5mmol does not enhance recovery from supra-maximal exercise in world-class athletes.

In vitro eye irritation testing using the open source reconstructed hemicornea - a ring trial.

PubMed

Mewes, Karsten R; Engelke, Maria; Zorn-Kruppa, Michaela; Bartok, Melinda; Tandon, Rashmi; Brandner, Johanna M; Petersohn, Dirk

2017-01-01

The aim of the present ring trial was to test whether two new methodological approaches for the in vitro classification of eye irritating chemicals can be reliably transferred from the developers' laboratories to other sites. Both test methods are based on the well-established open source reconstructed 3D hemicornea models. In the first approach, the initial depth of injury after chemical treatment in the hemicornea model is derived from the quantitative analysis of histological sections. In the second approach, tissue viability, as a measure for corneal damage after chemical treatment, is analyzed separately for epithelium and stroma of the hemicornea model. The three independent laboratories that participated in the ring trial produced their own hemicornea models according to the test producer's instructions, thus supporting the open source concept. A total of 9 chemicals with different physicochemical and eye-irritating properties were tested to assess the between-laboratory reproducibility (BLR), the predictive performance, as well as possible limitations of the test systems. The BLR was 62.5% for the first and 100% for the second method. Both methods enabled to discriminate Cat. 1 chemicals from all non-Cat. 1 substances, which qualifies them to be used in a top-down approach. However, the selectivity between No Cat. and Cat. 2 chemicals still needs optimization.

Assessment of Age-Related Differences in Functional Capacity Using the Virtual Reality Functional Capacity Assessment Tool (VRFCAT)

PubMed Central

Atkins, A.S.; Stroescu, I.; Spagnola, N.B.; Davis, V.G.; Patterson, T.D.; Narasimhan, M.; Harvey, P.D.; Keefe, R.S.E.

2015-01-01

Clinical trials for primary prevention and early intervention in preclinical AD require measures of functional capacity with improved sensitivity to deficits in healthier, non-demented individuals. To this end, the Virtual Reality Functional Capacity Assessment Tool (VRFCAT) was developed as a direct performance-based assessment of functional capacity that is sensitive to changes in function across multiple populations. Using a realistic virtual reality environment, the VRFCAT assesses a subject's ability to complete instrumental activities associated with a shopping trip. The present investigation represents an initial evaluation of the VRFCAT as a potential co-primary measure of functional capacity in healthy aging and preclinical MCI/AD by examining test-retest reliability and associations with cognitive performance in healthy young and older adults. The VRFCAT was compared and contrasted with the UPSA-2-VIM, a traditional performance-based assessment utilizing physical props. Results demonstrated strong age-related differences in performance on each VRFCAT outcome measure, including total completion time, total errors, and total forced progressions. VRFCAT performance showed strong correlations with cognitive performance across both age groups. VRFCAT Total Time demonstrated good test-retest reliability (ICC=.80 in young adults; ICC=.64 in older adults) and insignificant practice effects, indicating the measure is suitable for repeated testing in healthy populations. Taken together, these results provide preliminary support for the VRFCAT as a potential measure of functionally relevant change in primary prevention and preclinical AD/MCI trials. PMID:26618145

Effect of carbohydrate composition on fluid balance, gastric emptying, and exercise performance.

PubMed

Cole, K J; Grandjean, P W; Sobszak, R J; Mitchell, J B

1993-12-01

This study examined the effects of serial feedings of different carbohydrate (CHO) solutions on plasma volume, gastric emptying (GE), and performance during prolonged cycling exercise. Solutions containing 6 g% glucose-sucrose (CHO-6GS), 8.3 g% high fructose corn syrup (CHO-8HF), 6.3 g% high fructose corn syrup + 2 g% glucose polymer (CHO-8HP), and a water placebo (WP) were compared. Ten trained male cyclists performed four cycling trials consisting of 105 min at 70% VO2max followed by a 15-min all-out, self-paced performance ride. Every 15 min the men consumed one of the four test solutions. Blood samples were taken before, during, and after exercise to determine blood glucose and plasma volume changes. There were no significant differences in performance, GE, or plasma volume changes between trials. Blood glucose was significantly elevated at the 105-min time-point in all CHO trials when compared to WP. The CHO-8HF and CHO-8HP drinks resulted in a significantly higher delivery of CHO to the intestine. Higher rates of CHO oxidation during the steady-state ride were observed only with the CHO-6GS drink.

Upper limb robot-assisted therapy in cerebral palsy: a single-blind randomized controlled trial.

PubMed

Gilliaux, Maxime; Renders, Anne; Dispa, Delphine; Holvoet, Dominique; Sapin, Julien; Dehez, Bruno; Detrembleur, Christine; Lejeune, Thierry M; Stoquart, Gaëtan

2015-02-01

Several pilot studies have evoked interest in robot-assisted therapy (RAT) in children with cerebral palsy (CP). To assess the effectiveness of RAT in children with CP through a single-blind randomized controlled trial. Sixteen children with CP were randomized into 2 groups. Eight children performed 5 conventional therapy sessions per week over 8 weeks (control group). Eight children completed 3 conventional therapy sessions and 2 robot-assisted sessions per week over 8 weeks (robotic group). For both groups, each therapy session lasted 45 minutes. Throughout each RAT session, the patient attempted to reach several targets consecutively with the REAPlan. The REAPlan is a distal effector robot that allows for displacements of the upper limb in the horizontal plane. A blinded assessment was performed before and after the intervention with respect to the International Classification of Functioning framework: body structure and function (upper limb kinematics, Box and Block test, Quality of Upper Extremity Skills Test, strength, and spasticity), activities (Abilhand-Kids, Pediatric Evaluation of Disability Inventory), and participation (Life Habits). During each RAT session, patients performed 744 movements on average with the REAPlan. Among the variables assessed, the smoothness of movement (P < .01) and manual dexterity assessed by the Box and Block test (P = .04) improved significantly more in the robotic group than in the control group. This single-blind randomized controlled trial provides the first evidence that RAT is effective in children with CP. Future studies should investigate the long-term effects of this therapy. © The Author(s) 2014.

Pretreatment data is highly predictive of liver chemistry signals in clinical trials.

PubMed

Cai, Zhaohui; Bresell, Anders; Steinberg, Mark H; Silberg, Debra G; Furlong, Stephen T

2012-01-01

The goal of this retrospective analysis was to assess how well predictive models could determine which patients would develop liver chemistry signals during clinical trials based on their pretreatment (baseline) information. Based on data from 24 late-stage clinical trials, classification models were developed to predict liver chemistry outcomes using baseline information, which included demographics, medical history, concomitant medications, and baseline laboratory results. Predictive models using baseline data predicted which patients would develop liver signals during the trials with average validation accuracy around 80%. Baseline levels of individual liver chemistry tests were most important for predicting their own elevations during the trials. High bilirubin levels at baseline were not uncommon and were associated with a high risk of developing biochemical Hy's law cases. Baseline γ-glutamyltransferase (GGT) level appeared to have some predictive value, but did not increase predictability beyond using established liver chemistry tests. It is possible to predict which patients are at a higher risk of developing liver chemistry signals using pretreatment (baseline) data. Derived knowledge from such predictions may allow proactive and targeted risk management, and the type of analysis described here could help determine whether new biomarkers offer improved performance over established ones.

Assessment of physiological demand in kitesurfing.

PubMed

Vercruyssen, F; Blin, N; L'huillier, D; Brisswalter, J

2009-01-01

To evaluate the physiological demands of kitesurfing, ten elite subjects performed an incremental running test on a 400-m track and a 30-min on-water crossing trial during a light crosswind (LW, 12-15 knots). Oxygen uptake (V(O)(2)) was estimated from the heart rate (HR) recorded during the crossing trial using the individual HR-V(O)(2) relationship determined during the incremental test. Blood lactate concentration [La(b)] was measured at rest and 3 min after the exercise completion. Mean HR and estimated V(O)(2) values represented, respectively 80.6 +/- 7.5% of maximal heart rate and 69.8 +/- 11.7% of maximal oxygen uptake for board speeds ranging from 15 to 17 knots. Low values for [La(b)] were observed at the end of crossing trial (2.1 +/- 1.2 mmol l(-1). This first analysis of kitesurfing suggests that the energy demand is mainly sustained by aerobic metabolism during a LW condition.

Memory for recently accessed visual attributes.

PubMed

Jiang, Yuhong V; Shupe, Joshua M; Swallow, Khena M; Tan, Deborah H

2016-08-01

Recent reports have suggested that the attended features of an item may be rapidly forgotten once they are no longer relevant for an ongoing task (attribute amnesia). This finding relies on a surprise memory procedure that places high demands on declarative memory. We used intertrial priming to examine whether the representation of an item's identity is lost completely once it becomes task irrelevant. If so, then the identity of a target on one trial should not influence performance on the next trial. In 3 experiments, we replicated the finding that a target's identity is poorly recognized in a surprise memory test. However, we also observed location and identity repetition priming across consecutive trials. These data suggest that, although explicit recognition on a surprise memory test may be impaired, some information about a particular target's identity can be retained after it is no longer needed for a task. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Studies of effects of closed microbial ecology. Report of 180-day test period

NASA Technical Reports Server (NTRS)

Kenyon, A. J.

1972-01-01

Experiments were performed to determine the influence closed microbial ecologies have on modification or simplification of natural intestinal flora of ferrets in a closed environmental system. On the basis of previous tests in which certain species (Salmonella and Bacteroides) were decreased at 90 days of enclosure, a second trial was constructed for 180-day tests. In this trial there was little difference in the 8 major classes of intestinal flora between animals in the Open and Closed environmental groups except for the level of Lactobacillus. It is of extreme importance to note that when both Open and Closed groups contracted hemorrhagic gastritis, the interrelationship of this agent with other intestinal flora produced a more profound effect on animals from the Closed Group, particularly with reference to Lactobacillus levels.

Systematic review of the clinical and economic value of gene expression profiles for invasive early breast cancer available in Europe.

PubMed

Blok, E J; Bastiaannet, E; van den Hout, W B; Liefers, G J; Smit, V T H B M; Kroep, J R; van de Velde, C J H

2018-01-01

Gene expression profiles with prognostic capacities have shown good performance in multiple clinical trials. However, with multiple assays available and numerous types of validation studies performed, the added value for daily clinical practice is still unclear. In Europe, the MammaPrint, OncotypeDX, PAM50/Prosigna and Endopredict assays are commercially available. In this systematic review, we aim to assess these assays on four important criteria: Assay development and methodology, clinical validation, clinical utility and economic value. We performed a literature search covering PubMed, Embase, Web of Science and Cochrane, for studies related to one or more of the four selected assays. We identified 147 papers for inclusion in this review. MammaPrint and OncotypeDX both have evidence available, including level IA clinical trial results for both assays. Both assays provide prognostic information. Predictive value has only been shown for OncotypeDX. In the clinical utility studies, a higher reduction in chemotherapy was achieved by OncotypeDX, although the number of available studies differ considerably between tests. On average, economic evaluations estimate that genomic testing results in a moderate increase in total costs, but that these costs are acceptable in relation to the expected improved patient outcome. PAM50/prosigna and EndoPredict showed comparable prognostic capacities, but with less economical and clinical utility studies. Furthermore, for these assays no level IA trial data are available yet. In summary, all assays have shown excellent prognostic capacities. The differences in the quantity and quality of evidence are discussed. Future studies shall focus on the selection of appropriate subgroups for testing and long-term outcome of validation trials, in order to determine the place of these assays in daily clinical practice. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Detecting small-study effects and funnel plot asymmetry in meta-analysis of survival data: A comparison of new and existing tests.

PubMed

Debray, Thomas P A; Moons, Karel G M; Riley, Richard D

2018-03-01

Small-study effects are a common threat in systematic reviews and may indicate publication bias. Their existence is often verified by visual inspection of the funnel plot. Formal tests to assess the presence of funnel plot asymmetry typically estimate the association between the reported effect size and their standard error, the total sample size, or the inverse of the total sample size. In this paper, we demonstrate that the application of these tests may be less appropriate in meta-analysis of survival data, where censoring influences statistical significance of the hazard ratio. We subsequently propose 2 new tests that are based on the total number of observed events and adopt a multiplicative variance component. We compare the performance of the various funnel plot asymmetry tests in an extensive simulation study where we varied the true hazard ratio (0.5 to 1), the number of published trials (N=10 to 100), the degree of censoring within trials (0% to 90%), and the mechanism leading to participant dropout (noninformative versus informative). Results demonstrate that previous well-known tests for detecting funnel plot asymmetry suffer from low power or excessive type-I error rates in meta-analysis of survival data, particularly when trials are affected by participant dropout. Because our novel test (adopting estimates of the asymptotic precision as study weights) yields reasonable power and maintains appropriate type-I error rates, we recommend its use to evaluate funnel plot asymmetry in meta-analysis of survival data. The use of funnel plot asymmetry tests should, however, be avoided when there are few trials available for any meta-analysis. © 2017 The Authors. Research Synthesis Methods Published by John Wiley & Sons, Ltd.

Physical performance and clinical outcomes in dialysis patients: a secondary analysis of the EXCITE trial.

PubMed

Torino, Claudia; Manfredini, Fabio; Bolignano, Davide; Aucella, Filippo; Baggetta, Rossella; Barillà, Antonio; Battaglia, Yuri; Bertoli, Silvio; Bonanno, Graziella; Castellino, Pietro; Ciurlino, Daniele; Cupisti, Adamasco; D'Arrigo, Graziella; De Paola, Luciano; Fabrizi, Fabrizio; Fatuzzo, Pasquale; Fuiano, Giorgio; Lombardi, Luigi; Lucisano, Gaetano; Messa, Piergiorgio; Rapanà, Renato; Rapisarda, Francesco; Rastelli, Stefania; Rocca-Rey, Lisa; Summaria, Chiara; Zuccalà, Alessandro; Tripepi, Giovanni; Catizone, Luigi; Zoccali, Carmine; Mallamaci, Francesca

2014-01-01

Scarce physical activity predicts shorter survival in dialysis patients. However, the relationship between physical (motor) fitness and clinical outcomes has never been tested in these patients. We tested the predictive power of an established metric of motor fitness, the Six-Minute Walking Test (6MWT), for death, cardiovascular events and hospitalization in 296 dialysis patients who took part in the trial EXCITE (ClinicalTrials.gov Identifier: NCT01255969). During follow up 69 patients died, 90 had fatal and non-fatal cardiovascular events, 159 were hospitalized and 182 patients had the composite outcome. In multivariate Cox models - including the study allocation arm and classical and non-classical risk factors - an increase of 20 walked metres during the 6MWT was associated to a 6% reduction of the risk for the composite end-point (P=0.001) and a similar relationship existed between the 6MWT, mortality (P<0.001) and hospitalizations (P=0.03). A similar trend was observed for cardiovascular events but this relationship did not reach statistical significance (P=0.09). Poor physical performance predicts a high risk of mortality, cardiovascular events and hospitalizations in dialysis patients. Future studies, including phase-2 EXCITE, will assess whether improving motor fitness may translate into better clinical outcomes in this high risk population. © 2014 S. Karger AG, Basel.

Effects of Tai Chi on Cognition and Fall Risk in Older Adults with Mild Cognitive Impairment: A Randomized Controlled Trial.

PubMed

Sungkarat, Somporn; Boripuntakul, Sirinun; Chattipakorn, Nipon; Watcharasaksilp, Kanokwan; Lord, Stephen R

2017-04-01

To examine whether combined center- and home-based Tai Chi training can improve cognitive ability and reduce physiological fall risk in older adults with amnestic mild cognitive impairment (a-MCI). Randomized controlled trial. Chiang Mai, Thailand. Adults aged 60 and older who met Petersen's criteria for multiple-domain a-MCI (N = 66). Three weeks center-based and 12 weeks home-based Tai Chi (50 minutes per session, 3 times per week). Cognitive tests, including Logical Memory (LM) delayed recall, Block Design, Digit Span forward and backward, and Trail-Making Test Part B-A (TMT B-A), and fall risk index using the Physiological Profile Assessment (PPA). At the end of the trial, performance on LM, Block Design, and TMT B-A were significantly better for the Tai Chi group than the control group after adjusting for baseline test performance. The Tai Chi group also had significantly better composite PPA score and PPA parameter scores: knee extension strength, reaction time, postural sway, and lower limb proprioception. Combined center- and home-based Tai Chi training three times per week for 15 weeks significantly improved cognitive function and moderately reduced physiological fall risk in older adults with multiple-domain a-MCI. Tai Chi may be particularly beneficial to older adults with this condition. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

Clinical Evaluation of Effects of Chronic Resveratrol Supplementation on Cerebrovascular Function, Cognition, Mood, Physical Function and General Well-Being in Postmenopausal Women-Rationale and Study Design.

PubMed

Evans, Hamish Michael; Howe, Peter Ranald Charles; Wong, Rachel Heloise Xiwen

2016-03-09

This methodological paper presents both a scientific rationale and a methodological approach for investigating the effects of resveratrol supplementation on mood and cognitive performance in postmenopausal women. Postmenopausal women have an increased risk of cognitive decline and dementia, which may be at least partly due to loss of beneficial effects of estrogen on the cerebrovasculature. We hypothesise that resveratrol, a phytoestrogen, may counteract this risk by enhancing cerebrovascular function and improving regional blood flow in response to cognitive demands. A clinical trial was designed to test this hypothesis. Healthy postmenopausal women were recruited to participate in a randomised, double-blind, placebo-controlled (parallel comparison) dietary intervention trial to evaluate the effects of resveratrol supplementation (75 mg twice daily) on cognition, cerebrovascular responsiveness to cognitive tasks and overall well-being. They performed the following tests at baseline and after 14 weeks of supplementation: Rey Auditory Verbal Learning Test, Cambridge Semantic Memory Battery, the Double Span and the Trail Making Task. Cerebrovascular function was assessed simultaneously by monitoring blood flow velocity in the middle cerebral arteries using transcranial Doppler ultrasound. This trial provides a model approach to demonstrate that, by optimising circulatory function in the brain, resveratrol and other vasoactive nutrients may enhance mood and cognition and ameliorate the risk of developing dementia in postmenopausal women and other at-risk populations.

The Effects of Binge Drinking on College Students’ Next-Day Academic Test-Taking Performance and Mood State

PubMed Central

Howland, Jonathan; Rohsenow, Damaris J; Greece, Jacey A; Littlefield, Caroline A; Almeida, Alissa; Heeren, Timothy; Winter, Michael; Bliss, Caleb A.; Hunt, Sarah; Hermos, John

2010-01-01

Aim To assess the effects of binge drinking on students’ next-day academic test-taking performance. Design A placebo-controlled cross-over design with randomly assigned order of conditions. Participants were randomized to either alcoholic beverage (mean =.12 g% breath alcohol concentration [BrAC]) or placebo on the first night and then received the other beverage a week later. The next day, participants were assessed on test-taking, neurocognitive performance and mood state. Participants 193 college students (≥ 21 years) recruited from greater Boston. Setting The trial was conducted at the General Clinical Research Center at the Boston Medical Center. Measurements The Graduate Record Exams © (GREs) and a quiz on a lecture presented the previous day measured test-taking performance; the Neurobehavioral Evaluation System (NES3) and the Psychomotor Vigilance Test (PVT) measured neurocognitive performance; and, the Profile of Mood States (POMS) measured mood. Findings Test-taking performance was not affected the morning after alcohol administration, but mood state and attention/reaction time were. Conclusion Drinking to a level of .12 g% BrAC does not affect next-day test-taking performance, but does affect some neurocognitive measures and mood state. PMID:20403018

A cluster randomized clinical trial comparing fit‐tested and non‐fit‐tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers

PubMed Central

MacIntyre, Chandini Raina; Wang, Quanyi; Cauchemez, Simon; Seale, Holly; Dwyer, Dominic E.; Yang, Peng; Shi, Weixian; Gao, Zhanhai; Pang, Xinghuo; Zhang, Yi; Wang, Xiaoli; Duan, Wei; Rahman, Bayzidur; Ferguson, Neil

2011-01-01

Please cite this paper as: MacIntyre et al. (2011) A cluster randomized clinical trial comparing fit‐tested and non‐fit‐tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2010.00198.x. Background  We compared the efficacy of medical masks, N95 respirators (fit tested and non fit tested), in health care workers (HCWs). Methods  A cluster randomized clinical trial (RCT) of 1441 HCWs in 15 Beijing hospitals was performed during the 2008/2009 winter. Participants wore masks or respirators during the entire work shift for 4 weeks. Outcomes included clinical respiratory illness (CRI), influenza‐like illness (ILI), laboratory‐confirmed respiratory virus infection and influenza. A convenience no‐mask/respirator group of 481 health workers from nine hospitals was compared. Findings  The rates of CRI (3·9% versus 6·7%), ILI (0·3% versus 0·6%), laboratory‐confirmed respiratory virus (1·4% versus 2·6%) and influenza (0·3% versus 1%) infection were consistently lower for the N95 group compared to medical masks. By intention‐to‐treat analysis, when P values were adjusted for clustering, non‐fit‐tested N95 respirators were significantly more protective than medical masks against CRI, but no other outcomes were significant. The rates of all outcomes were higher in the convenience no‐mask group compared to the intervention arms. There was no significant difference in outcomes between the N95 arms with and without fit testing. Rates of fit test failure were low. In a post hoc analysis adjusted for potential confounders, N95 masks and hospital level were significant, but medical masks, vaccination, handwashing and high‐risk procedures were not. Interpretation  Rates of infection in the medical mask group were double that in the N95 group. A benefit of respirators is suggested but would need to be confirmed by a larger trial, as this study may have been underpowered. The finding on fit testing is specific to the type of respirator used in the study and cannot be generalized to other respirators. Trial registration  Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN: ACTRN12609000257268 (http://www.anzctr.org.au). PMID:21477136

Changes in balance, functional performance and fall risk following whole body vibration training and vitamin D supplementation in institutionalized elderly women. A 6 month randomized controlled trial.

PubMed

Bogaerts, An; Delecluse, Christophe; Boonen, Steven; Claessens, Albrecht L; Milisen, Koen; Verschueren, Sabine M P

2011-03-01

Falls in the elderly constitute a growing public health problem. This randomized controlled trial investigated the potential benefit of 6 months of whole body vibration (WBV) training and/or vitamin D supplementation on balance, functionality and estimated fall risk in institutionalized elderly women. A total of 113 women (mean age: 79.6) were randomly assigned to either a WBV or a no-training group, receiving either a conventional dose (880 IU/d) or a high dose (1600 IU/d) of vitamin D3. The WBV group performed exercises on a vibration platform 3×/week. Balance was evaluated by computerized posturography. Functionality was assessed by 10 m walk test, Timed up and Go (TUG) performance and endurance capacity (Shuttle Walk). Fall risk was determined with the Physiological Profile Assessment. Performance on the 10 m walk test and on TUG improved over time in all groups. For none of the parameters, high-dose vitamin D resulted in a better performance than conventional dosing. The improvements in the WBV group in endurance capacity, walking at preferred speed, and TUG were significantly larger than the changes with supplementation alone. No additional benefit of WBV training could be detected on fall risk and postural control, although sway velocity and maximal isometric knee extension strength improved only in the WBV group. This trial showed that a high-dose vitamin D supplementation is not more efficient than conventional dosing in improving functionality in institutionalized elderly. WBV training on top of vitamin D supplementation provided an added benefit with regard to walking, TUG performance, and endurance capacity. Copyright © 2010 Elsevier B.V. All rights reserved.

The reliability of an instrumented start block analysis system.

PubMed

Tor, Elaine; Pease, David L; Ball, Kevin A

2015-02-01

The swimming start is highly influential to overall competition performance. Therefore, it is paramount to develop reliable methods to perform accurate biomechanical analysis of start performance for training and research. The Wetplate Analysis System is a custom-made force plate system developed by the Australian Institute of Sport--Aquatic Testing, Training and Research Unit (AIS ATTRU). This sophisticated system combines both force data and 2D digitization to measure a number of kinetic and kinematic parameter values in an attempt to evaluate start performance. Fourteen elite swimmers performed two maximal effort dives (performance was defined as time from start signal to 15 m) over two separate testing sessions. Intraclass correlation coefficients (ICC) were used to determine each parameter's reliability. The kinetic parameters all had ICC greater than 0.9 except the time of peak vertical force (0.742). This may have been due to variations in movement initiation after the starting signal between trials. The kinematic and time parameters also had ICC greater than 0.9 apart from for the time of maximum depth (0.719). This parameter was lower due to the swimmers varying their depth between trials. Based on the high ICC scores for all parameters, the Wetplate Analysis System is suitable for biomechanical analysis of swimming starts.

Exercise in Patients on Dialysis: A Multicenter, Randomized Clinical Trial.

PubMed

Manfredini, Fabio; Mallamaci, Francesca; D'Arrigo, Graziella; Baggetta, Rossella; Bolignano, Davide; Torino, Claudia; Lamberti, Nicola; Bertoli, Silvio; Ciurlino, Daniele; Rocca-Rey, Lisa; Barillà, Antonio; Battaglia, Yuri; Rapanà, Renato Mario; Zuccalà, Alessandro; Bonanno, Graziella; Fatuzzo, Pasquale; Rapisarda, Francesco; Rastelli, Stefania; Fabrizi, Fabrizio; Messa, Piergiorgio; De Paola, Luciano; Lombardi, Luigi; Cupisti, Adamasco; Fuiano, Giorgio; Lucisano, Gaetano; Summaria, Chiara; Felisatti, Michele; Pozzato, Enrico; Malagoni, Anna Maria; Castellino, Pietro; Aucella, Filippo; Abd ElHafeez, Samar; Provenzano, Pasquale Fabio; Tripepi, Giovanni; Catizone, Luigi; Zoccali, Carmine

2017-04-01

Previous studies have suggested the benefits of physical exercise for patients on dialysis. We conducted the Exercise Introduction to Enhance Performance in Dialysis trial, a 6-month randomized, multicenter trial to test whether a simple, personalized walking exercise program at home, managed by dialysis staff, improves functional status in adult patients on dialysis. The main study outcomes included change in physical performance at 6 months, assessed by the 6-minute walking test and the five times sit-to-stand test, and in quality of life, assessed by the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire. We randomized 296 patients to normal physical activity (control; n =145) or walking exercise ( n =151); 227 patients (exercise n =104; control n =123) repeated the 6-month evaluations. The distance covered during the 6-minute walking test improved in the exercise group (mean distance±SD: baseline, 328±96 m; 6 months, 367±113 m) but not in the control group (baseline, 321±107 m; 6 months, 324±116 m; P <0.001 between groups). Similarly, the five times sit-to-stand test time improved in the exercise group (mean time±SD: baseline, 20.5±6.0 seconds; 6 months, 18.2±5.7 seconds) but not in the control group (baseline, 20.9±5.8 seconds; 6 months, 20.2±6.4 seconds; P =0.001 between groups). The cognitive function score ( P =0.04) and quality of social interaction score ( P =0.01) in the kidney disease component of the KDQOL-SF improved significantly in the exercise arm compared with the control arm. Hence, a simple, personalized, home-based, low-intensity exercise program managed by dialysis staff may improve physical performance and quality of life in patients on dialysis. Copyright © 2017 by the American Society of Nephrology.

Comparison of credible patients of very low intelligence and non-credible patients on neurocognitive performance validity indicators.

PubMed

Smith, Klayton; Boone, Kyle; Victor, Tara; Miora, Deborah; Cottingham, Maria; Ziegler, Elizabeth; Zeller, Michelle; Wright, Matthew

2014-01-01

The purpose of this archival study was to identify performance validity tests (PVTs) and standard IQ and neurocognitive test scores, which singly or in combination, differentiate credible patients of low IQ (FSIQ ≤ 75; n = 55) from non-credible patients. We compared the credible participants against a sample of 74 non-credible patients who appeared to have been attempting to feign low intelligence specifically (FSIQ ≤ 75), as well as a larger non-credible sample (n = 383) unselected for IQ. The entire non-credible group scored significantly higher than the credible participants on measures of verbal crystallized intelligence/semantic memory and manipulation of overlearned information, while the credible group performed significantly better on many processing speed and memory tests. Additionally, credible women showed faster finger-tapping speeds than non-credible women. The credible group also scored significantly higher than the non-credible subgroup with low IQ scores on measures of attention, visual perceptual/spatial tasks, processing speed, verbal learning/list learning, and visual memory, and credible women continued to outperform non-credible women on finger tapping. When cut-offs were selected to maintain approximately 90% specificity in the credible group, sensitivity rates were highest for verbal and visual memory measures (i.e., TOMM trials 1 and 2; Warrington Words correct and time; Rey Word Recognition Test total; RAVLT Effort Equation, Trial 5, total across learning trials, short delay, recognition, and RAVLT/RO discriminant function; and Digit Symbol recognition), followed by select attentional PVT scores (i.e., b Test omissions and time to recite four digits forward). When failure rates were tabulated across seven most sensitive scores, a cut-off of ≥ 2 failures was associated with 85.4% specificity and 85.7% sensitivity, while a cut-off of ≥ 3 failures resulted in 95.1% specificity and 66.0% sensitivity. Results are discussed in light of extant literature and directions for future research.

Development of a high-velocity free-flight launcher : the Ames light-gas gun

NASA Technical Reports Server (NTRS)

Charters, A C; Denardo, B Pat; Rossow, Vernon J

1955-01-01

Recent interest in long-range missiles has stimulated a search for new experimental techniques which can reproduce in the laboratory the high temperatures and Mach numbers associated with the missiles' flight. One promising possibility lies in free-flight testing of laboratory models which are flown at the full velocity of the missile. In this type of test, temperatures are approximated and aerodynamic heating of the model is representative of that experienced by the missile in high-velocity flight. A prime requirement of the free-flight test technique is a device which had the capacity for launching models at the velocities desired. In response to thie need, a gun firing light models at velocities up to 15,000 feet per second has been developed at the Ames Aeronautical Laboratory. The design of this gun, the analysis of its performance, and the results of the initial firing trials are described in this paper. The firing trials showed that the measured velocities and pressures agreed well with the predicted values. Also, the erosion of the launch tube was very small for the eleven rounds fired. The performance of the gun suggests that it will prove to be a satisfactory launcher for high-velocity free-flight tests. However, it should be mentioned that only the gross performance has been evaluated so far, and, consequently, the operation of the gun must be investigated in further detail before its performance can be reliably predicted over its full operating range.

HIIT enhances endurance performance and aerobic characteristics more than high-volume training in trained rowers.

PubMed

Ní Chéilleachair, Niamh J; Harrison, Andrew J; Warrington, Giles D

2017-06-01

This study compared the effects of long slow distance training (LSD) with high-intensity interval training (HIIT) in rowers. Nineteen well-trained rowers performed three tests before and after an 8-week training intervention: (1) 2000 m time trial; (2) seven-stage incremental step test to determine maximum oxygen uptake ([Formula: see text]O 2max ), power output at [Formula: see text]O 2max (W[Formula: see text]O 2max ), peak power output (PPO), rowing economy and blood lactate indices and (3) seven-stroke power-output test to determine maximal power output (W max ) and force (F max ). After baseline testing, participants were randomly assigned either to a HIIT or LSD group. The LSD comprised 10 weekly aerobic sessions. The HIIT also comprised 10 weekly sessions: 8 aerobic and 2 HIIT. The HIIT sessions comprised 6-8 × 2.5 min intervals at 100% PPO with recovery time based on heart rate (HR) returning to 70% HR max . Results demonstrated that the HIIT produced greater improvement in 2000 m time trial performance than the LSD (effect size (ES) = 0.25). Moreover, the HIIT produced greater improvements in [Formula: see text]O 2max (ES = 0.95, P = 0.035) and power output at lactate threshold (W LT ) (ES = 1.15, P = 0.008). Eight weeks of HIIT performed at 100% PPO is more effective than LSD in improving performance and aerobic characteristics in well-trained rowers.

Modafinil improves real driving performance in patients with hypersomnia: a randomized double-blind placebo-controlled crossover clinical trial.

PubMed

Philip, Pierre; Chaufton, Cyril; Taillard, Jacques; Capelli, Aurore; Coste, Olivier; Léger, Damien; Moore, Nicholas; Sagaspe, Patricia

2014-03-01

Patients with excessive daytime sleepiness (EDS) are at high risk for driving accidents, and physicians are concerned by the effect of alerting drugs on driving skills of sleepy patients. No study has up to now investigated the effect of modafinil (a reference drug to treat EDS in patients with hypersomnia) on on-road driving performance of patients suffering from central hypersomnia. The objective is to evaluate in patients with central hypersomnia the effect of a wake-promoting drug on real driving performance and to assess the relationship between objective sleepiness and driving performance. Randomized, crossover, double-blind placebo-controlled trial conducted among 13 patients with narcolepsy and 14 patients with idiopathic hypersomnia. Patients were randomly assigned to receive modafinil (400 mg) or placebo for 5 days prior to the driving test. Each condition was separated by at least 3 weeks of washout. Mean number of Inappropriate Line Crossings, Standard Deviation of Lateral Position of the vehicle and mean sleep latency in the Maintenance of Wakefulness Test were assessed. Modafinil reduced the mean number of Inappropriate Line Crossings and Standard Deviation of Lateral Position of the vehicle compared to placebo (F(1,25) = 4.88, P < 0.05 and F(1,25) = 3.87, P = 0.06 tendency). Mean sleep latency at the Maintenance of Wakefulness Test significantly correlated with the mean number of Inappropriate Line Crossings (r = -0.41, P < 0.001). Modafinil improves driving performance in patients with narcolepsy and idiopathic hypersomnia. The Maintenance of Wakefulness Test is a suitable clinical tool to assess fitness to drive in this population.

Improving training of laparoscopic tissue manipulation skills using various visual force feedback types.

PubMed

Smit, Daan; Spruit, Edward; Dankelman, Jenny; Tuijthof, Gabrielle; Hamming, Jaap; Horeman, Tim

2017-01-01

Visual force feedback allows trainees to learn laparoscopic tissue manipulation skills. The aim of this experimental study was to find the most efficient visual force feedback method to acquire these skills. Retention and transfer validity to an untrained task were assessed. Medical students without prior experience in laparoscopy were randomized in three groups: Constant Force Feedback (CFF) (N = 17), Bandwidth Force Feedback (BFF) (N = 16) and Fade-in Force Feedback (N = 18). All participants performed a pretest, training, post-test and follow-up test. The study involved two dissimilar tissue manipulation tasks, one for training and one to assess transferability. Participants performed six trials of the training task. A force platform was used to record several force parameters. A paired-sample t test showed overall lower force parameter outcomes in the post-test compared to the pretest (p < .001). A week later, the force parameter outcomes were still significantly lower than found in the pretest (p < .005). Participants also performed the transfer task in the post-test (p < .02) and follow-up (p < .05) test with lower force parameter outcomes compared to the pretest. A one-way MANOVA indicated that in the post-test the CFF group applied 50 % less Mean Absolute Nonzero Force (p = .005) than the BFF group. All visual force feedback methods showed to be effective in decreasing tissue manipulation force as no major differences were found between groups in the post and follow-up trials. The BFF method is preferred for it respects individual progress and minimizes distraction.

Convergent validity and sex differences in healthy elderly adults for performance on 3D virtual reality navigation learning and 2D hidden maze tasks.

PubMed

Tippett, William J; Lee, Jang-Han; Mraz, Richard; Zakzanis, Konstantine K; Snyder, Peter J; Black, Sandra E; Graham, Simon J

2009-04-01

This study assessed the convergent validity of a virtual environment (VE) navigation learning task, the Groton Maze Learning Test (GMLT), and selected traditional neuropsychological tests performed in a group of healthy elderly adults (n = 24). The cohort was divided equally between males and females to explore performance variability due to sex differences, which were subsequently characterized and reported as part of the analysis. To facilitate performance comparisons, specific "efficiency" scores were created for both the VE navigation task and the GMLT. Men reached peak performance more rapidly than women during VE navigation and on the GMLT and significantly outperformed women on the first learning trial in the VE. Results suggest reasonable convergent validity across the VE task, GMLT, and selected neuropsychological tests for assessment of spatial memory.

Childhood Obesity and Academic Performance: The Role of Working Memory

PubMed Central

Wu, Nan; Chen, Yulu; Yang, Jinhua; Li, Fei

2017-01-01

The present study examined the role of working memory in the association between childhood obesity and academic performance, and further determined whether memory deficits in obese children are domain-specific to certain tasks or domain-general. A total of 227 primary school students aged 10–13 years were analyzed for weight and height, of which 159 children (44 “obese,” 23 “overweight,” and 92 “normal weight”) filled out questionnaires on school performance and socioeconomic status. And then, all subjects finished three kinds of working memory tasks based on the digit memory task in 30 trials, which were image-generated with a series of numbers recall trial sets. After each trial set, subjects were given 5 s to recall and write down the numbers which hand appeared in the trial, in the inverse order in which they had appeared. The results showed there were significant academic performance differences among the three groups, with normal-weight children scoring higher than overweight and obese children after Bonferroni correction. A mediation model revealed a partial indirect effect of working memory in the relationship between obesity and academic performance. Although the performance of obese children in basic working memory tests was poorer than that of normal-weight children, they recalled more items than normal-weight children in working memory tasks involving with food/drink. Working memory deficits partially explain the poor academic performance of obese children. Those results indicated the obese children show domain-specific working memory deficits, whereas they recall more items than normal-weight children in working memory tasks associated with food/drink. PMID:28469593

Childhood Obesity and Academic Performance: The Role of Working Memory.

PubMed

Wu, Nan; Chen, Yulu; Yang, Jinhua; Li, Fei

2017-01-01

The present study examined the role of working memory in the association between childhood obesity and academic performance, and further determined whether memory deficits in obese children are domain-specific to certain tasks or domain-general. A total of 227 primary school students aged 10-13 years were analyzed for weight and height, of which 159 children (44 "obese," 23 "overweight," and 92 "normal weight") filled out questionnaires on school performance and socioeconomic status. And then, all subjects finished three kinds of working memory tasks based on the digit memory task in 30 trials, which were image-generated with a series of numbers recall trial sets. After each trial set, subjects were given 5 s to recall and write down the numbers which hand appeared in the trial, in the inverse order in which they had appeared. The results showed there were significant academic performance differences among the three groups, with normal-weight children scoring higher than overweight and obese children after Bonferroni correction. A mediation model revealed a partial indirect effect of working memory in the relationship between obesity and academic performance. Although the performance of obese children in basic working memory tests was poorer than that of normal-weight children, they recalled more items than normal-weight children in working memory tasks involving with food/drink. Working memory deficits partially explain the poor academic performance of obese children. Those results indicated the obese children show domain-specific working memory deficits, whereas they recall more items than normal-weight children in working memory tasks associated with food/drink.

Population-centered Risk- and Evidence-based Dental Interprofessional Care Team (PREDICT): study protocol for a randomized controlled trial.

PubMed

Cunha-Cruz, Joana; Milgrom, Peter; Shirtcliff, R Michael; Bailit, Howard L; Huebner, Colleen E; Conrad, Douglas; Ludwig, Sharity; Mitchell, Melissa; Dysert, Jeanne; Allen, Gary; Scott, JoAnna; Mancl, Lloyd

2015-06-20

To improve the oral health of low-income children, innovations in dental delivery systems are needed, including community-based care, the use of expanded duty auxiliary dental personnel, capitation payments, and global budgets. This paper describes the protocol for PREDICT (Population-centered Risk- and Evidence-based Dental Interprofessional Care Team), an evaluation project to test the effectiveness of new delivery and payment systems for improving dental care and oral health. This is a parallel-group cluster randomized controlled trial. Fourteen rural Oregon counties with a publicly insured (Medicaid) population of 82,000 children (0 to 21 years old) and pregnant women served by a managed dental care organization are randomized into test and control counties. In the test intervention (PREDICT), allied dental personnel provide screening and preventive services in community settings and case managers serve as patient navigators to arrange referrals of children who need dentist services. The delivery system intervention is paired with a compensation system for high performance (pay-for-performance) with efficient performance monitoring. PREDICT focuses on the following: 1) identifying eligible children and gaining caregiver consent for services in community settings (for example, schools); 2) providing risk-based preventive and caries stabilization services efficiently at these settings; 3) providing curative care in dental clinics; and 4) incentivizing local delivery teams to meet performance benchmarks. In the control intervention, care is delivered in dental offices without performance incentives. The primary outcome is the prevalence of untreated dental caries. Other outcomes are related to process, structure and cost. Data are collected through patient and staff surveys, clinical examinations, and the review of health and administrative records. If effective, PREDICT is expected to substantially reduce disparities in dental care and oral health. PREDICT can be disseminated to other care organizations as publicly insured clients are increasingly served by large practice organizations. ClinicalTrials.gov NCT02312921 6 December 2014. The Robert Wood Johnson Foundation and Advantage Dental Services, LLC, are supporting the evaluation.

The effect of age-at-testing on verbal memory among children following severe traumatic brain injury.

PubMed

Silberg, Tamar; Ahonniska-Assa, Jaana; Levav, Miriam; Eliyahu, Roni; Peleg-Pilowsky, Tamar; Brezner, Amichai; Vakil, Eli

2016-01-01

Memory deficits are a common sequelae following childhood traumatic brain injury (TBI), which often have serious implications on age-related academic skills. The current study examined verbal memory performance using the Rey Auditory Verbal Learning Test (RAVLT) in a pediatric TBI sample. Verbal memory abilities as well as the effect of age at-testing on performance were examined. A sample of 67 children following severe TBI (age average = 12.3 ± 2.74) and 67 matched controls were evaluated using the RAVLT. Age effect at assessment was examined using two age groups: above and below 12 years of age during evaluation. Differences between groups were examined via the 9 RAVLT learning trials and the 7 composite scores conducted out of them. Children following TBI recalled significantly less words than controls on all RAVLT trials and had significantly lower scores on all composite scores. However, all of these scores fell within the low average range. Further analysis revealed significantly lower than average performance among the older children (above 12 years), while scores of the younger children following TBI fell within average limits. To conclude, verbal memory deficits among children following severe TBI demonstrate an age-at-testing effect with more prominent problems occurring above 12 years at the time of evaluation. Yet, age-appropriate performance among children below 12 years of age may not accurately describe memory abilities at younger ages following TBI. It is therefore recommended that clinicians address child's age at testing and avoid using a single test as an indicator of verbal memory functioning post TBI.

Acute effects of two different initial heart rates on testing the Repeated Sprint Ability in young soccer players.

PubMed

Ruscello, B; Briotti, G; Tozzo, N; Partipilo, F; Taraborelli, M; Zeppetella, A; Padulo, J; D'Ottavio, S

2015-10-01

The aim of this paper was to investigate the acute effects of two different initial heart rates intensities when testing the repeated sprint ability (RSA) performances in young soccer players. Since there are many kinds of pre-match warm-ups, we chose to take as an absolute indicator of internal load the heart rate reached at the end of two different warm-up protocols (60 vs. 90% HRmax) and to compare the respective RSA performances. The RSA tests were performed on fifteen male soccer players (age: 17.9±1.5 years) with two sets of ten shuttle-sprints (15+15 m) with a 1:3 exercise to rest ratio, in different days (randomized order) with different HR% (60 & 90% HRmax). In order to compare the different sprint performances a Fatigue Index (FI%) was computed, while the blood lactate concentrations (BLa-) were measured before and after testing, to compare metabolic demand. Significant differences among trials within each sets (P<0.01) were found. Differences between sets were also found, especially comparing the last five trials for each set (Factorial ANOVA; P<0.01), effect size values confirming the relevance of these differences. Although the BLa- after warm-up was higher (36%) between 90% vs. 60% HRmax, after the RSA test the differences were considerably low (7%). Based on physiological information's this methodological approach (testing with initial 90%HRmax) reflects more realistically the metabolic background in which a soccer player operates during a real match. This background may be partially reproduced by warming up protocols that, by duration and metabolic commitment, can reproduce conveniently the physiological conditions encountered in a real game (e.g. HRmax≈85-95%; BLa->4 mmol/L(-1)).

Effects of the antidepressant drug moclobemide on learning and memory in rats.

PubMed

Getova, D; Dimitrova, D; Roukounakis, I

2003-12-01

Moclobemide is a well known drug with antidepressant action. The aim of this study was to investigate the effects of moclobemide on learning and memory processes in Sprague Dawley rats. Over a 5-day period, learning sessions with 30 trials per day and memory retention tests were performed. The conditioned responses (avoidances), the unconditioned responses (escapes) and the intertrial crossings were observed. An active avoidance test was carried out using a shuttle box. Two passive avoidance tests were used: step-through (using a light chamber) and step-down (using a platform). In the step-through passive avoidance test, the learning and retention sessions consisted of three trials each and the latency of reaction times (the rat remaining in the light chamber for more than 180 sec) was used as criterion. In the step-down passive avoidance test, learning and retention sessions consisted of two trials and the latency of reaction times (the rat remaining on the platform for 60 sec) was used as criterion. In the active avoidance tests, moclobemide dose-dependently increased the number of avoidances during learning sessions and maintained this number in memory retention tests. Moclobemide did not alter the number of escapes, but did increase motor activity. In the passive avoidance tests, moclobemide also increased the latency of reaction times in learning and short memory retrieval tests. These findings suggest that moclobemide improves learning and memory processes in active and passive avoidance tests and has a cognition-enhancing effect. (c) 2003 Prous Science

Catch trials in force field learning influence adaptation and consolidation of human motor memory

PubMed Central

Stockinger, Christian; Focke, Anne; Stein, Thorsten

2014-01-01

Force field studies are a common tool to investigate motor adaptation and consolidation. Thereby, subjects usually adapt their reaching movements to force field perturbations induced by a robotic device. In this context, so-called catch trials, in which the disturbing forces are randomly turned off, are commonly used to detect after-effects of motor adaptation. However, catch trials also produce sudden large motor errors that might influence the motor adaptation and the consolidation process. Yet, the detailed influence of catch trials is far from clear. Thus, the aim of this study was to investigate the influence of catch trials on motor adaptation and consolidation in force field experiments. Therefore, 105 subjects adapted their reaching movements to robot-generated force fields. The test groups adapted their reaching movements to a force field A followed by learning a second interfering force field B before retest of A (ABA). The control groups were not exposed to force field B (AA). To examine the influence of diverse catch trial ratios, subjects received catch trials during force field adaptation with a probability of either 0, 10, 20, 30, or 40%, depending on the group. First, the results on motor adaptation revealed significant differences between the diverse catch trial ratio groups. With increasing amount of catch trials, the subjects' motor performance decreased and subjects' ability to accurately predict the force field—and therefore internal model formation—was impaired. Second, our results revealed that adapting with catch trials can influence the following consolidation process as indicated by a partial reduction to interference. Here, the optimal catch trial ratio was 30%. However, detection of consolidation seems to be biased by the applied measure of performance. PMID:24795598

A test of object permanence in a new-world monkey species, cotton top tamarins (Saguinus oedipus).

PubMed

Neiworth, Julie J; Steinmark, Eric; Basile, Benjamin M; Wonders, Ryann; Steely, Frances; DeHart, Catherine

2003-03-01

Cotton top tamarins were tested in visible and invisible displacement tasks in a method similar to that used elsewhere to test squirrel monkeys and orangutans. All subjects performed at levels significantly above chance on visible ( n=8) and invisible ( n=7) displacements, wherein the tasks included tests of the perseverance error, tests of memory in double and triple displacements, and "catch" trials that tested for the use of the experimenter's hand as a cue for the correct cup. Performance on all nine tasks was significantly higher than chance level selection of cups, and tasks using visible displacements generated more accurate performance than tasks using invisible displacements. Performance was not accounted for by a practice effect based on exposure to successive tasks. Results suggest that tamarins possess stage 6 object permanence capabilities, and that in a situation involving brief exposure to tasks and foraging opportunities, tracking objects' movements and responding more flexibly are abilities expressed readily by the tamarins.

Unreported links between trial registrations and published articles were identified using document similarity measures in a cross-sectional analysis of ClinicalTrials.gov.

PubMed

Dunn, Adam G; Coiera, Enrico; Bourgeois, Florence T

2018-03-01

Trial registries can be used to measure reporting biases and support systematic reviews, but 45% of registrations do not provide a link to the article reporting on the trial. We evaluated the use of document similarity methods to identify unreported links between ClinicalTrials.gov and PubMed. We extracted terms and concepts from a data set of 72,469 ClinicalTrials.gov registrations and 276,307 PubMed articles and tested methods for ranking articles across 16,005 reported links and 90 manually identified unreported links. Performance was measured by the median rank of matching articles and the proportion of unreported links that could be found by screening ranked candidate articles in order. The best-performing concept-based representation produced a median rank of 3 (interquartile range [IQR] 1-21) for reported links and 3 (IQR 1-19) for the manually identified unreported links, and term-based representations produced a median rank of 2 (1-20) for reported links and 2 (IQR 1-12) in unreported links. The matching article was ranked first for 40% of registrations, and screening 50 candidate articles per registration identified 86% of the unreported links. Leveraging the growth in the corpus of reported links between ClinicalTrials.gov and PubMed, we found that document similarity methods can assist in the identification of unreported links between trial registrations and corresponding articles. Copyright © 2017 Elsevier Inc. All rights reserved.

Development and Testing of a USM High Altitude Balloon

NASA Astrophysics Data System (ADS)

Thaheer, A. S. Mohamed; Ismail, N. A.; Yusoff, S. H. Md.; Nasirudin, M. A.

2018-04-01

This paper discusses on tests conducted on the component and subsystem level during development of the USM High Altitude Balloon (HAB). The tests conducted by selecting initial components then tested individually based on several case studies such as reliability test, camera viewing, power consumption, thermal capability, and parachute performance. Then, the component is integrated into sub-system level for integration and functionality test. The preliminary result is utilized to tune the components and sub-systems and trial launch is conducted where the sample images are recorded and atmospheric data successfully collected.

Chimpanzees' (Pan troglodytes) use of gaze cues in object-choice tasks: different methods yield different results.

PubMed

Barth, Jochen; Reaux, James E; Povinelli, Daniel J

2005-04-01

To assess the influence of different procedures on chimpanzees' performance in object-choice tasks, five adult chimpanzees were tested using three experimenter-given cues to food location: gazing, glancing, and pointing. These cues were delivered to the subjects in an identical fashion but were deployed within the context of two distinct meta-procedures that have been previously employed with this species with conflicting results. In one procedure, the subjects entered the test unit and approached the experimenter (who had already established the cue) on each trial. In the other procedure, the subjects stayed in the test unit throughout a session, witnessed the hiding procedure, and waited for a delay of 10 s during which the cue was provided. The subjects scored at high levels far exceeding chance in response to the gaze cue only when they approached the experimenter for each trial. They performed at chance levels when they stayed inside the test unit throughout the session. They scored at chance levels on all other cues irrespective of the procedure. These findings imply that (a) chimpanzees can immediately exploit social gaze cues, and (b) previous conflicting findings were likely due to the different meta-procedures that were used.

Effects of distance learning on clinical management of LUTS in primary care: a randomised trial.

PubMed

Wolters, René; Wensing, Michel; Klomp, Maarten; Lagro-Jansen, Toine; Weel, Chris van; Grol, Richard

2005-11-01

To determine the effect of a distance learning programme on general practice management of men with lower urinary tract symptoms (LUTS). A cluster randomised controlled trial was performed. General practitioners (GPs) were randomised to a distance learning programme accompanied with educational materials or to a control group only receiving mailed clinical guidelines on LUTS. Clinical management was considered as outcome. Sixty-three GPs registered care management of 187 patients older than 50 years attending the practice because of LUTS. The intervention group showed a lower referral rate to a urologist (OR: 0.08 (95% CI: 0.02-0.40)), but no effect on PSA testing or prescription of medication. PSA testing tended to be requested more frequently by intervention group GPs. Secondary analysis showed patients in the intervention group received more educational materials (OR: 75.6 (95% CI: 13.60-419.90)). The educational programme had impact on clinical management without changing PSA testing. Distance learning is an promising method for continuing education. Activating distance learning packages are a potentially effective method for improving professional performance. Emotional matters as PSA testing probably need a more complex approach.

Early Failures Benefit Subsequent Task Performance.

PubMed

Igata, Hideyoshi; Sasaki, Takuya; Ikegaya, Yuji

2016-02-17

Animals navigate using cognitive maps. However, how they adaptively exploit these maps in changing environments is not fully understood. In this study, we investigated the problem-solving behaviors of mice in a complicated maze in which multiple routes with different intersections were available (Test 1). Although all mice eventually settled on the shortest route, mice that initially exhibited more trial-and-error exploration solved the maze more rapidly. We then introduced one or two barriers that obstructed learned routes such that mice had to establish novel roundabout detours (Tests 2/3). Solutions varied among mice but were predictable based on individual early trial-and-error patterns observed in Test 1: mice that had initially explored more extensively found better solutions. Finally, when the barriers were removed (Test 4), all mice reverted to the best solution after active exploration. Thus, early active exploration helps mice to develop optimal strategies.

The prevalence of dogs with lymphocyte proliferative responses to food allergens in canine allergic dermatitis.

PubMed

Kawano, K; Oumi, K; Ashida, Y; Horiuchi, Y; Mizuno, T

2013-01-01

The aim of the present study was to examine the correlation between the results of lymphocyte proliferative test (LPT) specific to food allergens and allergic skin diseases in dogs. Investigations were performed in 138 dogs with allergic skin diseases diagnosed in a private animal hospital. Of the 138 animals, 97 cases had positive reactions in LPT specific to food allergens. Of these 97 dogs, 67 animals were diagnosed with canine atopic dermatitis (CAD), but 30 dogs did not have IgE antibodies to environmental allergens. As 14 dogs out of 30 animals showed a positive result, 12 dogs underwent elimination diet trial based on the test results and all of them showed improvement in the pruritus score. Therefore, we conclude that LPT is an effective diagnostic test for allergic skin disease. Results of the lymphocyte test are useful in the identification of food allergens for the elimination diet trial.

Reliability and feasibility of the six minute walk test in subjects with myotonic dystrophy.

PubMed

Kierkegaard, Marie; Tollbäck, Anna

2007-12-01

The objective was to describe test-retest reliability and feasibility of the six minute walk test in adult subjects with myotonic dystrophy type 1. Twelve subjects (28-68 years, mean 44) performed three six minute walk tests on two occasions, one week apart. Relative reliability was high (ICC(2.1)=0.99) and absolute reliability values were low (standard error of measurement 12 m, repeatability 33 m). Feasibility was investigated in a sample of 64 subjects (19-70 years, mean 43). Fifty-two subjects were able to perform two tests on the same day. Subjects with severe proximal weakness had difficulties performing repeated tests. A practice trial followed by a second test on the same day can be recommended for most subjects, and the best test should be used for evaluations. In conclusion, even though the study sample was small, the present study indicates that the six minute walk test is reliable and feasible in subjects with myotonic dystrophy type 1.

Performance Prediction of Constrained Waveform Design for Adaptive Radar

DTIC Science & Technology

2016-11-01

Kullback - Leibler divergence. χ2 Goodness - of - Fit Test We compute the estimated CDF for both models with 10000 MC trials. For Model 1 we observed a p-value of ...was clearly similar in its physical attributes, but the measures used , ( Kullback - Leibler , Chi-Square Test and the trace of the covariance) showed...models goodness - of - fit we look at three measures (1) χ2- Test (2) Trace of the inverse

Cardiorespiratory performance during prolonged swimming tests with salmonids: a perspective on temperature effects and potential analytical pitfalls.

PubMed

Farrell, A P

2007-11-29

A prolonged swimming trial is the most common approach in studying steady-state changes in oxygen uptake, cardiac output and tissue oxygen extraction as a function of swimming speed in salmonids. The data generated by these sorts of studies are used here to support the idea that a maximum oxygen uptake is reached during a critical swimming speed test. Maximum oxygen uptake has a temperature optimum. Potential explanations are advanced to explain why maximum aerobic performance falls off at high temperature. The valuable information provided by critical swimming tests can be confounded by non-steady-state swimming behaviours, which typically occur with increasing frequency as salmonids approach fatigue. Two major concerns are noted. Foremost, measurements of oxygen uptake during swimming can considerably underestimate the true cost of transport near critical swimming speed, apparently in a temperature-dependent manner. Second, based on a comparison with voluntary swimming ascents in a raceway, forced swimming trials in a swim tunnel respirometer may underestimate critical swimming speed, possibly because fish in a swim tunnel respirometer are unable to sustain a ground speed.

A controlled time-series trial of clinical reminders: using computerized firm systems to make quality improvement research a routine part of mainstream practice.

PubMed Central

Goldberg, H. I.; Neighbor, W. E.; Cheadle, A. D.; Ramsey, S. D.; Diehr, P.; Gore, E.

2000-01-01

OBJECTIVE: To explore the feasibility of conducting unobtrusive interventional research in community practice settings by integrating firm-system techniques with time-series analysis of relational-repository data. STUDY SETTING: A satellite teaching clinic divided into two similar, but geographically separated, primary care group practices called firms. One firm was selected by chance to receive the study intervention. Forty-two providers and 2,655 patients participated. STUDY DESIGN: A nonrandomized controlled trial of computer-generated preventive reminders. Net effects were determined by quantitatively combining population-level data from parallel experimental and control interrupted time series extending over two-month baseline and intervention periods. DATA COLLECTION: Mean rates at which mammography, colorectal cancer screening, and cholesterol testing were performed on patients due to receive each maneuver at clinic visits were the trial's outcome measures. PRINCIPAL FINDINGS: Mammography performance increased on the experimental firm by 154 percent (0.24 versus 0.61, p = .03). No effect on fecal occult blood testing was observed. Cholesterol ordering decreased on both the experimental (0.18 versus 0.1 1, p = .02) and control firms (0.13 versus 0.07, p = .03) coincident with national guidelines retreating from recommending screening for young adults. A traditional uncontrolled interrupted time-series design would have incorrectly attributed the experimental-firm decrease to the introduction of reminders. The combined analysis properly indicated that no net prompting effect had occurred, as the difference between firms in cholesterol testing remained stochastically stable over time (0.05 versus 0.04, p = .75). A logistic-regression analysis applied to individual-level data produced equivalent findings. The trial incurred no supplementary data collection costs. CONCLUSIONS: The apparent validity and practicability of our reminder implementation study should encourage others to develop computerized firm systems capable of conducting controlled time-series trials. Images Fig. 1 PMID:10737451

Structured didactic teaching sessions improve medical student neurology clerkship test scores: a pilot study.

PubMed

Menkes, Daniel L; Reed, Mary

2008-01-01

To determine the effectiveness of didactic case-based instruction methodology to improve medical student comprehension of common neurological illnesses and neurological emergencies. Neurology department, academic university. 415 third and fourth year medical students performing a required four week neurology clerkship. Raw test scores on a 1 hour, 50-item clinical vignette based examination and open-ended questions in a post-clerkship feedback session. There was a statistically significant improvement in overall test scores (p<0.001). Didactic teaching sessions have a significant positive impact on neurology student clerkship test score performance and perception of their educational experience. Confirmation of these results across multiple specialties in a multi-center trial is warranted.

Inference of median difference based on the Box-Cox model in randomized clinical trials.

PubMed

Maruo, K; Isogawa, N; Gosho, M

2015-05-10

In randomized clinical trials, many medical and biological measurements are not normally distributed and are often skewed. The Box-Cox transformation is a powerful procedure for comparing two treatment groups for skewed continuous variables in terms of a statistical test. However, it is difficult to directly estimate and interpret the location difference between the two groups on the original scale of the measurement. We propose a helpful method that infers the difference of the treatment effect on the original scale in a more easily interpretable form. We also provide statistical analysis packages that consistently include an estimate of the treatment effect, covariance adjustments, standard errors, and statistical hypothesis tests. The simulation study that focuses on randomized parallel group clinical trials with two treatment groups indicates that the performance of the proposed method is equivalent to or better than that of the existing non-parametric approaches in terms of the type-I error rate and power. We illustrate our method with cluster of differentiation 4 data in an acquired immune deficiency syndrome clinical trial. Copyright © 2015 John Wiley & Sons, Ltd.

Test equality in binary data for a 4 × 4 crossover trial under a Latin-square design.

PubMed

Lui, Kung-Jong; Chang, Kuang-Chao

2016-10-15

When there are four or more treatments under comparison, the use of a crossover design with a complete set of treatment-receipt sequences in binary data is of limited use because of too many treatment-receipt sequences. Thus, we may consider use of a 4 × 4 Latin square to reduce the number of treatment-receipt sequences when comparing three experimental treatments with a control treatment. Under a distribution-free random effects logistic regression model, we develop simple procedures for testing non-equality between any of the three experimental treatments and the control treatment in a crossover trial with dichotomous responses. We further derive interval estimators in closed forms for the relative effect between treatments. To evaluate the performance of these test procedures and interval estimators, we employ Monte Carlo simulation. We use the data taken from a crossover trial using a 4 × 4 Latin-square design for studying four-treatments to illustrate the use of test procedures and interval estimators developed here. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Therapeutic Drug Monitoring of Asparaginase Activity-Method Comparison of MAAT and AHA Test Used in the International AIEOP-BFM ALL 2009 Trial.

PubMed

Lanvers-Kaminsky, Claudia; Rüffer, Andrea; Würthwein, Gudrun; Gerss, Joachim; Zucchetti, Massimo; Ballerini, Andrea; Attarbaschi, Andishe; Smisek, Petr; Nath, Christa; Lee, Samiuela; Elitzur, Sara; Zimmermann, Martin; Möricke, Anja; Schrappe, Martin; Rizzari, Carmelo; Boos, Joachim

2018-02-01

In the international AIEOP-BFM ALL 2009 trial, asparaginase (ASE) activity was monitored after each dose of pegylated Escherichia coli ASE (PEG-ASE). Two methods were used: the aspartic acid β-hydroxamate (AHA) test and medac asparaginase activity test (MAAT). As the latter method overestimates PEG-ASE activity because it calibrates using E. coli ASE, method comparison was performed using samples from the AIEOP-BFM ALL 2009 trial. PEG-ASE activities were determined using MAAT and AHA test in 2 sets of samples (first set: 630 samples and second set: 91 samples). Bland-Altman analysis was performed on ratios between MAAT and AHA tests. The mean difference between both methods, limits of agreement, and 95% confidence intervals were calculated and compared for all samples and samples grouped according to the calibration ranges of the MAAT and the AHA test. PEG-ASE activity determined using the MAAT was significantly higher than when determined using the AHA test (P < 0.001; Wilcoxon signed-rank test). Within the calibration range of the MAAT (30-600 U/L), PEG-ASE activities determined using the MAAT were on average 23% higher than PEG-ASE activities determined using the AHA test. This complies with the mean difference reported in the MAAT manual. With PEG-ASE activities >600 U/L, the discrepancies between MAAT and AHA test increased. Above the calibration range of the MAAT (>600 U/L) and the AHA test (>1000 U/L), a mean difference of 42% was determined. Because more than 70% of samples had PEG-ASE activities >600 U/L and required additional sample dilution, an overall mean difference of 37% was calculated for all samples (37% for the first and 34% for the second set). Comparison of the MAAT and AHA test for PEG-ASE activity confirmed a mean difference of 23% between MAAT and AHA test for PEG-ASE activities between 30 and 600 U/L. The discrepancy increased in samples with >600 U/L PEG-ASE activity, which will be especially relevant when evaluating high PEG-ASE activities in relation to toxicity, efficacy, and population pharmacokinetics.

Impact of Implementation and Conduct of the HEALTHY Primary Prevention Trial on Student Performance

PubMed Central

Hernandez, Arthur E.; Marcus, Marsha D.; Hirst, Kathryn; Faith, Myles S.; Goldberg, Linn; Treviño, Roberto P.

2016-01-01

Purpose To determine whether a school-wide intervention program to reduce risk factors for type 2 diabetes (T2D) affected student achievement, rates of disciplinary actions, and attendance rates. Design The HEALTHY primary prevention trial was designed to evaluate a comprehensive school-based intervention to reduce factors for T2D, especially overweight and obesity. Students were followed up from beginning of sixth grade (Fall 2006) through end of eighth grade (Spring 2009). Setting Forty-two middle schools at seven U.S. sites. Subjects Schools were randomized in equal numbers at each site to intervention (21 schools, 2307 students) or control (21 schools, 2296 students). Intervention An integrated school-wide program that focused on (1) foods and beverages, (2) physical education, (3) classroom-based behavior change and education, and (4) social marketing communication and promotional campaigns. Measures Aggregate (grade- and school-wide) test performance (passing rate), attendance, and referrals for disciplinary actions. Analysis Descriptive statistics and tests of intervention versus control using mixed linear models methods to adjust for the clustering of students within schools. Results There were no differences between intervention and control schools in test performance for mathematics (p = .7835) or reading (p = .6387), attendance (p = .5819), or referrals for disciplinary action (p = .8671). Conclusion The comprehensive HEALTHY intervention and associated research procedures did not negatively impact student achievement test scores, attendance, or referrals for disciplinary action. PMID:24200256

Impact of implementation and conduct of the HEALTHY primary prevention trial on student performance.

PubMed

Hernandez, Arthur E; Marcus, Marsha D; Hirst, Kathryn; Faith, Myles S; Goldberg, Linn; Treviño, Roberto P

2014-01-01

To determine whether a school-wide intervention program to reduce risk factors for type 2 diabetes (T2D) affected student achievement, rates of disciplinary actions, and attendance rates. The HEALTHY primary prevention trial was designed to evaluate a comprehensive school-based intervention to reduce factors for T2D, especially overweight and obesity. Students were followed up from beginning of sixth grade (Fall 2006) through end of eighth grade (Spring 2009). Forty-two middle schools at seven U.S. sites. Schools were randomized in equal numbers at each site to intervention (21 schools, 2307 students) or control (21 schools, 2296 students). Intervention . An integrated school-wide program that focused on (1) foods and beverages, (2) physical education, (3) classroom-based behavior change and education, and (4) social marketing communication and promotional campaigns. Aggregate (grade- and school-wide) test performance (passing rate), attendance, and referrals for disciplinary actions. Descriptive statistics and tests of intervention versus control using mixed linear models methods to adjust for the clustering of students within schools. There were no differences between intervention and control schools in test performance for mathematics (p = .7835) or reading (p = .6387), attendance (p = .5819), or referrals for disciplinary action (p = .8671). The comprehensive HEALTHY intervention and associated research procedures did not negatively impact student achievement test scores, attendance, or referrals for disciplinary action.

Lower-volume muscle-damaging exercise protects against high-volume muscle-damaging exercise and the detrimental effects on endurance performance.

PubMed

Burt, Dean; Lamb, Kevin; Nicholas, Ceri; Twist, Craig

2015-07-01

This study examined whether lower-volume exercise-induced muscle damage (EIMD) performed 2 weeks before high-volume muscle-damaging exercise protects against its detrimental effect on running performance. Sixteen male participants were randomly assigned to a lower-volume (five sets of ten squats, n = 8) or high-volume (ten sets of ten squats, n = 8) EIMD group and completed baseline measurements for muscle soreness, knee extensor torque, creatine kinase (CK), a 5-min fixed-intensity running bout and a 3-km running time-trial. Measurements were repeated 24 and 48 h after EIMD, and the running time-trial after 48 h. Two weeks later, both groups repeated the baseline measurements, ten sets of ten squats and the same follow-up testing (Bout 2). Data analysis revealed increases in muscle soreness and CK and decreases in knee extensor torque 24-48 h after the initial bouts of EIMD. Increases in oxygen uptake [Formula: see text], minute ventilation [Formula: see text] and rating of perceived exertion were observed during fixed-intensity running 24-48 h after EIMD Bout 1. Likewise, time increased and speed and [Formula: see text] decreased during a 3-km running time-trial 48 h after EIMD. Symptoms of EIMD, responses during fixed-intensity and running time-trial were attenuated in the days after the repeated bout of high-volume EIMD performed 2 weeks after the initial bout. This study demonstrates that the protective effect of lower-volume EIMD on subsequent high-volume EIMD is transferable to endurance running. Furthermore, time-trial performance was found to be preserved after a repeated bout of EIMD.

Gender differences in landmark learning for virtual navigation: the role of distance to a goal.

PubMed

Chamizo, V D; Artigas, A A; Sansa, J; Banterla, F

2011-09-01

We used a new virtual program in two experiments to prepare subjects to perform the Morris water task (www.nesplora.com). The subjects were Psychology students; they were trained to locate a safe platform amidst the presence of four pinpoint landmarks spaced around the edge of the pool (i.e., two landmarks relatively near the platform and two landmarks relatively distant away from it). At the end of the training phase, we administered one test trial without the platform and recorded the amount of time that the students had spent in the platform quadrant. In Experiment 1, we conducted the test trial in the presence of one or two of the distant landmarks. When only one landmark was present during testing, performance fell to chance. However, the men outperformed the women when the two distant landmarks were both present. Experiment 2 replicated the previous results and extended it by showing that no sex differences exist when the searching process is based on the near landmarks. Both the men and the women had similarly good performances when the landmarks were present both individually and together. When present together, an addition effect was found. Far landmark tests favor configural learning processes, whereas near landmark tests favor elemental learning. Our findings suggest that other factors in addition to the use of directional cues can underlie the sex differences in the spatial learning process. Thus, we expand upon previous research in the field. Copyright © 2011 Elsevier B.V. All rights reserved.

Warm-ups for military fitness testing: rapid evidence assessment of the literature.

PubMed

Zeno, Stacey A; Purvis, Dianna; Crawford, Cindy; Lee, Courtney; Lisman, Peter; Deuster, Patricia A

2013-07-01

Warm-up exercises are commonly used before exercise as a method to physiologically prepare for strenuous physical activity. Various warm-up exercises are often implemented but without scientific merit and, at times, may be detrimental to performance. To date, no systematic reviews have examined the effectiveness of warm-up exercises for military physical fitness test (PFT) or combat fitness test (CFT). The purpose of this rapid evidence assessment of the literature was to examine the quantity, quality, and effectiveness of warm-up exercises for PFT and identify those that might increase PFT and/or CFT scores, as reported in the literature. Literature searches of randomized controlled trials were performed across various databases from database inception to May 2011. Methodological quality of included studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) 50 criteria for randomized controlled trial designs, and studies were individually described. Subject matter experts summarized the results applicable or generalizable to military testing. The search yielded a total of 1177 citations, with 37 fitting our inclusion criteria. Cardiovascular warm-ups increased sprint/running time, but dynamic stretching and dynamic warm-ups had the most positive outcome for the various exercise tests examined. Systematically, static stretching had no beneficial or detrimental effect on exercise performance but did improve range of movement exercises. Selected warm-up exercise may increase PFT and possibly CFT scores. Further research is needed to investigate the efficacy of dynamic stretching and dynamic warm-ups.

Gene therapy for Parkinson's disease: Disease modification by GDNF family of ligands.

PubMed

Kirik, Deniz; Cederfjäll, Erik; Halliday, Glenda; Petersén, Åsa

2017-01-01

Gene transfer is a promising drug delivery method of advanced therapeutic entities for Parkinson's disease. One advantage over conventional therapies, such as peripheral delivery of the dopamine pre-cursor l-DOPA, is site-specific expression of proteins with regenerative, disease-modifying and potentially neuroprotective capacity. Several clinical trials have been performed to test the capacity of glial-cell line derived neurotrophic factor and neurturin to rescue degenerating dopaminergic neurons in the substantia nigra and their axon terminals in the striatum by delivery of these neurotrophic factors either as purified protein or by means of viral vector mediated gene delivery to the brain. Although gene therapy approaches tested so far have been shown to be safe, none met their primary endpoints in phase II clinical trials designed and powered to test the efficacy of the intervention. Within the scope of this review we aim to describe the state-of-the-art in the field, how different technical parameters were translated from pre-clinical studies in non-human primates to clinical trials, and what these trials taught us regarding important factors that may pave the way to the success of gene therapy for the treatment of Parkinson's disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Simulation-based multiprofessional obstetric anaesthesia training conducted in situ versus off-site leads to similar individual and team outcomes: a randomised educational trial

PubMed Central

Sørensen, Jette Led; van der Vleuten, Cees; Rosthøj, Susanne; Østergaard, Doris; LeBlanc, Vicki; Johansen, Marianne; Ekelund, Kim; Starkopf, Liis; Lindschou, Jane; Gluud, Christian; Weikop, Pia; Ottesen, Bent

2015-01-01

Objective To investigate the effect of in situ simulation (ISS) versus off-site simulation (OSS) on knowledge, patient safety attitude, stress, motivation, perceptions of simulation, team performance and organisational impact. Design Investigator-initiated single-centre randomised superiority educational trial. Setting Obstetrics and anaesthesiology departments, Rigshospitalet, University of Copenhagen, Denmark. Participants 100 participants in teams of 10, comprising midwives, specialised midwives, auxiliary nurses, nurse anaesthetists, operating theatre nurses, and consultant doctors and trainees in obstetrics and anaesthesiology. Interventions Two multiprofessional simulations (clinical management of an emergency caesarean section and a postpartum haemorrhage scenario) were conducted in teams of 10 in the ISS versus the OSS setting. Primary outcome Knowledge assessed by a multiple choice question test. Exploratory outcomes Individual outcomes: scores on the Safety Attitudes Questionnaire, stress measurements (State-Trait Anxiety Inventory, cognitive appraisal and salivary cortisol), Intrinsic Motivation Inventory and perceptions of simulations. Team outcome: video assessment of team performance. Organisational impact: suggestions for organisational changes. Results The trial was conducted from April to June 2013. No differences between the two groups were found for the multiple choice question test, patient safety attitude, stress measurements, motivation or the evaluation of the simulations. The participants in the ISS group scored the authenticity of the simulation significantly higher than did the participants in the OSS group. Expert video assessment of team performance showed no differences between the ISS versus the OSS group. The ISS group provided more ideas and suggestions for changes at the organisational level. Conclusions In this randomised trial, no significant differences were found regarding knowledge, patient safety attitude, motivation or stress measurements when comparing ISS versus OSS. Although participant perception of the authenticity of ISS versus OSS differed significantly, there were no differences in other outcomes between the groups except that the ISS group generated more suggestions for organisational changes. Trial registration number NCT01792674. PMID:26443654

Lack of strategy holding: a new pattern of learning deficit in cortical dementias.

PubMed

Benedet, María J; Lauro-Grotto, Rosapia; Giotti, Chiara

2009-09-01

The aim of this study was to demonstrate, by means of systematic research and qualitative data analysis, the presence, among a group of patients with fronto-temporal lobar degeneration of a subgroup that, at variance with the standard pattern, is able to devise and implement learning strategies, but appear impaired at carrying them on from a trial to the next. In order to provide evidence of the existence of a group of patients showing this type of learning disability, that we refer to as lack of strategy holding, we performed a stepwise hierarchical cluster analysis of a set of variables whose scores were selected from the subject's performance at the Test de Aprendizaje Verbal España-Complutense. Results substantiate the segregation of three groups of subjects characterized by the following patterns of performance: normal elderly individuals, who show a quite preserved ability to discover a semantic strategy along the learning trials and to carry it from a trial to the next, patients presenting with a deficit in implementing semantic learning strategies and possibly use of serial and/or phonological strategies to perform the task, and to patients who, although able to generate and implement appropriate learning strategies, appear unable to carry them over the learning trials. The presence of this new pattern raises a few questions that seem worth trying to address.

Improvement in balance using a virtual reality-based stepping exercise: a randomized controlled trial involving individuals with chronic stroke.

PubMed

Lloréns, Roberto; Gil-Gómez, José-Antonio; Alcañiz, Mariano; Colomer, Carolina; Noé, Enrique

2015-03-01

To study the clinical effectiveness and the usability of a virtual reality-based intervention compared with conventional physical therapy in the balance recovery of individuals with chronic stroke. Randomized controlled trial. Outpatient neurorehabilitation unit. A total of 20 individuals with chronic stroke. The intervention consisted of 20 one-hour sessions, five sessions per week. The experimental group combined 30 minutes with the virtual reality-based intervention with 30 minutes of conventional training. The control group underwent one hour conventional therapy. Balance performance was assessed at the beginning and at the end of the trial using the Berg Balance Scale, the balance and gait subscales of the Tinetti Performance-Oriented Mobility Assessment, the Brunel Balance Assessment, and the 10-m Walking Test. Subjective data of the virtual reality-based intervention were collected from the experimental group, with a feedback questionnaire at the end of the trial. The results revealed a significant group-by-time interaction in the scores of the Berg Balance Scale (p < 0.05) and in the 10-m Walking Test (p < 0.05). Post-hoc analyses showed greater improvement in the experimental group: 3.8 ±2.6 vs. 1.8 ±1.4 in the Berg Balance Scale, -1.9 ±1.6 seconds vs. 0.0 ±2.3 seconds in the 10-m Walking Test, and also in the number of participants who increased level in the Brunel Balance Assessment (χ(2) = 2.5, p < 0.01). Virtual reality interventions can be an effective resource to enhance the improvement of balance in individuals with chronic stroke. © The Author(s) 2014.

Classification of mouth movements using 7 T fMRI.

PubMed

Bleichner, M G; Jansma, J M; Salari, E; Freudenburg, Z V; Raemaekers, M; Ramsey, N F

2015-12-01

A brain-computer interface (BCI) is an interface that uses signals from the brain to control a computer. BCIs will likely become important tools for severely paralyzed patients to restore interaction with the environment. The sensorimotor cortex is a promising target brain region for a BCI due to the detailed topography and minimal functional interference with other important brain processes. Previous studies have shown that attempted movements in paralyzed people generate neural activity that strongly resembles actual movements. Hence decodability for BCI applications can be studied in able-bodied volunteers with actual movements. In this study we tested whether mouth movements provide adequate signals in the sensorimotor cortex for a BCI. The study was executed using fMRI at 7 T to ensure relevance for BCI with cortical electrodes, as 7 T measurements have been shown to correlate well with electrocortical measurements. Twelve healthy volunteers executed four mouth movements (lip protrusion, tongue movement, teeth clenching, and the production of a larynx activating sound) while in the scanner. Subjects performed a training and a test run. Single trials were classified based on the Pearson correlation values between the activation patterns per trial type in the training run and single trials in the test run in a 'winner-takes-all' design. Single trial mouth movements could be classified with 90% accuracy. The classification was based on an area with a volume of about 0.5 cc, located on the sensorimotor cortex. If voxels were limited to the surface, which is accessible for electrode grids, classification accuracy was still very high (82%). Voxels located on the precentral cortex performed better (87%) than the postcentral cortex (72%). The high reliability of decoding mouth movements suggests that attempted mouth movements are a promising candidate for BCI in paralyzed people.

Funding source, conflict of interest and positive conclusions in neuro-oncology clinical trials.

PubMed

Moraes, Fabio Y; Mendez, Lucas C; Taunk, Neil K; Raman, Srinivas; Suh, John H; Souhami, Luis; Slotman, Ben; Weltman, Eduardo; Spratt, Daniel E; Berlin, Alejandro; Marta, Gustavo N

2018-02-01

We aimed to test any association between authors' conclusions and self-reported COI or funding sources in central nervous system (CNS) studies. A review was performed for CNS malignancy clinical trials published in the last 5 years. Two investigators independently classified study conclusions according to authors' endorsement of the experimental therapy. Statistical models were used to test for associations between positive conclusions and trials characteristics. From February 2010 to February 2015, 1256 articles were retrieved; 319 were considered eligible trials. Positive conclusions were reported in 56.8% of trials with industry-only, 55.6% with academia-only, 44.1% with academia and industry, 77.8% with none, and 76.4% with not described funding source (p = 0.011). Positive conclusions were reported in 60.4% of trials with unrelated COI, 60% with related COI, and 60% with no COI reported (p = 0.997). Factors that were significantly associated with the presence of positive conclusion included trials design (phase 1) [OR 11.64 (95 CI 4.66-29.09), p < 0.001], geographic location (outside North America or Europe) [OR 1.96 (95 CI 1.05-3.79), P = 0.025], primary outcomes (non-overall or progression free survival) [OR 3.74 (95 CI 2.27-6.18), p < 0.001], and failure to disclose funding source [OR 2.45 (95 CI 1.22-5.22), p = 0.011]. In a multivariable regression model, all these factors remained significantly associated with trial's positive conclusion. Funding source and self-reported COI did not appear to influence the CNS trials conclusion. Funding source information and COI disclosure were under-reported in 14.1 and 17.2% of the CNS trials. Continued efforts are needed to increase rates of both COI and funding source reporting.

Multicenter Trial of Sentinel Node Biopsy for Breast Cancer Using Both Technetium Sulfur Colloid and Isosulfan Blue Dye

PubMed Central

Tafra, Lorraine; Lannin, Donald R.; Swanson, Melvin S.; Van Eyk, Jason J.; Verbanac, Kathryn M.; Chua, Arlene N.; Ng, Peter C.; Edwards, Maxine S.; Halliday, Bradford E.; Henry, C. Alan; Sommers, Linda M.; Carman, Claire M.; Molin, Melinda R.; Yurko, John E.; Perry, Roger R.; Williams, Robert

2001-01-01

Objective To determine the factors associated with false-negative results on sentinel node biopsy and sentinel node localization (identification rate) in patients with breast cancer enrolled in a multicenter trial using a combination technique of isosulfan blue with technetium sulfur colloid (Tc99). Summary Background Data Sentinel node biopsy is a diagnostic test used to detect breast cancer metastases. To test the reliability of this method, a complete lymph node dissection must be performed to determine the false-negative rate. Single-institution series have reported excellent results, although one multicenter trial reported a false-negative rate as high as 29% using radioisotope alone. A multicenter trial was initiated to test combined use of Tc99 and isosulfan blue. Methods Investigators (both private-practice and academic surgeons) were recruited after attending a course on the technique of sentinel node biopsy. No investigator participated in a learning trial before entering patients. Tc99 and isosulfan blue were injected into the peritumoral region. Results Five hundred twenty-nine patients underwent 535 sentinel node biopsy procedures for an overall identification rate in finding a sentinel node of 87% and a false-negative rate of 13%. The identification rate increased and the false-negative rate decreased to 90% and 4.3%, respectively, after investigators had performed more than 30 cases. Univariate analysis of tumor showed the poorest success rate with older patients and inexperienced surgeons. Multivariate analysis identified both age and experience as independent predictors of failure. However, with older patients, inexperienced surgeons, and patients with five or more metastatic axillary nodes, the false-negative rate was consistently greater. Conclusions This multicenter trial, from both private practice and academic institutions, is an excellent indicator of the general utility of sentinel node biopsy. It establishes the factors that play an important role (patient age, surgical experience, tumor location) and those that are irrelevant (prior surgery, tumor size, Tc99 timing). This widens the applicability of the technique and identifies factors that require further investigation. PMID:11141225

Utility, reliability, sensitivity and validity of an online test system designed to monitor changes in cognitive function in clinical trials.

PubMed

Wesnes, Keith A; Brooker, Helen; Ballard, Clive; McCambridge, Laura; Stenton, Robert; Corbett, Anne

2017-12-01

The advent of long-term remotely conducted clinical trials requires assessments which can be administered online. This paper considers the utility, reliability, sensitivity and validity of an internet-based system for measuring changes in cognitive function which is being used in one such trial. The Platform for Research Online to investigate Genetics and Cognition in Ageing is a 10-year longitudinal and entirely remote study launched in November 2015. The CogTrack TM System is being used to monitor changes in important aspects of cognitive function using tests of attention, information processing and episodic memory. On study entry, the participants performed CogTrack TM up to three times over seven days, and these data are evaluated in this paper. During the first six months of the study, 14 531 individuals aged 50 to 94 years enrolled and performed the CogTrack TM System, 8627 of whom completed three test sessions. On the first administration, 99.4% of the study tasks were successfully completed. Repeated testing showed training/familiarisation effects on four of the ten measures which had largely stabilised by the third test session. The factor structure of the various measures was found to be robust. Evaluation of the influence of age identified clinically relevant declines over the age range of the population on one or more measures from all tasks. The results of these analyses identify CogTrack TM to be a practical and valid method to reliably, sensitively, remotely and repeatedly collect cognitive data from large samples of individuals aged 50 and over. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

[Cross-cultural validated adaptation of dysfunctional voiding symptom score (DVSS) to Japanese language and cognitive linguistics in questionnaire for pediatric patients].

PubMed

Imamura, Masaaki; Usui, Tomoko; Johnin, Kazuyoshi; Yoshimura, Koji; Farhat, Walid; Kanematsu, Akihiro; Ogawa, Osamu

2014-07-01

Validated questionnaire for evaluation of pediatric lower urinary tract symptoms (LUTS) is of a great need. We performed cross-cultural validated adaptation of Dysfunctional Voiding Symptom Score (DVSS) to Japanese language, and assessed whether children understand and respond to questionnaire correctly, using cognitive linguistic approach. We translated DVSS into two Japanese versions according to a standard validation methodology: translation, synthesis, back-translation, expert review, and pre-testing. One version was written in adult language for parents, and the other was written in child language for children. Pre-testing was done with 5 to 15-year-old patients visiting us, having normal intelligence. A specialist in cognitive linguistics observed the response by children and parents to DVSS as an interviewer. When a child could not understand a question without adding or paraphrasing the question by the parents, it was defined as 'misidentification'. We performed pretesting with 2 trial versions of DVSS before having the final version. The pre-testing for the first trial version was done for 32 patients (male to female ratio was 19 : 13). The pre-testing for the second trial version was done for 11 patients (male to female ratio was 8 : 3). In DVSS in child language, misidentification was consistently observed for representation of time or frequency. We completed the formal validated translation by amending the problems raised in the pre-testing. The cross-cultural validated adaptation of DVSS to child and adult Japanese was completed. Since temporal perception is not fully developed in children, caution should be taken for using the terms related with time or frequency in the questionnaires for children.

Reliability and minimal detectable change of physical performance measures in individuals with pre-manifest and manifest Huntington disease.

PubMed

Quinn, Lori; Khalil, Hanan; Dawes, Helen; Fritz, Nora E; Kegelmeyer, Deb; Kloos, Anne D; Gillard, Jonathan W; Busse, Monica

2013-07-01

Clinical intervention trials in people with Huntington disease (HD) have been limited by a lack of reliable and appropriate outcome measures. The purpose of this study was to determine the reliability and minimal detectable change (MDC) of various outcome measures that are potentially suitable for evaluating physical functioning in individuals with HD. This was a multicenter, prospective, observational study. Participants with pre-manifest and manifest HD (early, middle, and late stages) were recruited from 8 international sites to complete a battery of physical performance and functional measures at 2 assessments, separated by 1 week. Test-retest reliability (using intraclass correlation coefficients) and MDC values were calculated for all measures. Seventy-five individuals with HD (mean age=52.12 years, SD=11.82) participated in the study. Test-retest reliability was very high (>.90) for participants with manifest HD for the Six-Minute Walk Test (6MWT), 10-Meter Walk Test, Timed "Up & Go" Test (TUG), Berg Balance Scale (BBS), Physical Performance Test (PPT), Barthel Index, Rivermead Mobility Index, and Tinetti Mobility Test (TMT). Many MDC values suggested a relatively high degree of inherent variability, particularly in the middle stage of HD. Minimum detectable change values for participants with manifest HD that were relatively low across disease stages were found for the BBS (5), PPT (5), and TUG (2.98). For individuals with pre-manifest HD (n=11), the 6MWT and Four Square Step Test had high reliability and low MDC values. The sample size for the pre-manifest HD group was small. The BBS, PPT, and TUG appear most appropriate for clinical trials aimed at improving physical functioning in people with manifest HD. Further research in people with pre-manifest HD is necessary.

A Novel Mobile Testing Equipment for Rock Cuttability Assessment: Vertical Rock Cutting Rig (VRCR)

NASA Astrophysics Data System (ADS)

Yasar, Serdar; Yilmaz, Ali Osman

2017-04-01

In this study, a new mobile rock cutting testing apparatus was designed and produced for rock cuttability assessment called vertical rock cutting rig (VRCR) which was designed specially to fit into hydraulic press testing equipment which are available in almost every rock mechanics laboratory. Rock cutting trials were initiated just after the production of VRCR along with calibration of the measuring load cell with an external load cell to validate the recorded force data. Then, controlled rock cutting tests with both relieved and unrelieved cutting modes were implemented on five different volcanic rock samples with a standard simple-shaped wedge tool. Additionally, core cutting test which is an important approach for roadheader performance prediction was simulated with VRCR. Mini disc cutters and point attack tools were used for execution of experimental trials. Results clearly showed that rock cutting tests were successfully realized and measuring system is delicate to rock strength, cutting depth and other variables. Core cutting test was successfully simulated, and it was also shown that rock cutting tests with mini disc cutters and point attack tools are also successful with VRCR.

Genetic associations between fibrinogen and cognitive performance in three Scottish cohorts.

PubMed

Marioni, Riccardo E; Deary, Ian J; Murray, Gordon D; Lowe, Gordon D O; Strachan, Mark W J; Luciano, Michelle; Houlihan, Lorna M; Gow, Alan J; Harris, Sarah E; Rumley, Ann; Stewart, Marlene C; Fowkes, F Gerry R; Price, Jackie F

2011-09-01

There is increasing evidence to suggest that elevated plasma levels of fibrinogen are associated with late-life cognitive performance. This study tested the association of single nucleotide polymorphisms in the fibrinogen α (FGA) and β (FGB) genes with cognitive performance. Data were analysed from three community-dwelling populations of older persons (>50 years) in central Scotland: the Aspirin for Asymptomatic Atherosclerosis (AAA) Trial (n = 2,091), the Edinburgh Type 2 Diabetes Study (ET2DS, n = 1,066), and the Lothian Birth Cohort 1936 (LBC1936, n = 1,091). Cognition was assessed using a battery of five, seven, and four psychometric tests, respectively. This information was used to derive a general cognitive factor. Weakly significant associations were found between the rs4220 (FGB), and rs2227412 (FGB) SNPs and a single test of cognitive performance in the AAA Trial (p < 0.05). These findings did not replicate in the LBC1936 or ET2DS cohorts, except for the rs2227412 SNP, which was significantly associated with the general cognitive factor in the ET2DS (p = 3.3 × 10(-4)). A summary term that combined results from all three studies suggested that the rs2227412 genotype associated with reduced cognitive ability also associated with higher plasma fibrinogen levels. These findings suggest a tentative role for fibrinogen as a determinant of late-life cognitive performance and justify further attempts at replication in older persons.

Random Versus Blocked Practice to Enhance Mental Representation in Golf Putting.

PubMed

Fazeli, Davoud; Taheri, HamidReza; Saberi Kakhki, Alireza

2017-06-01

The purpose of this study was to investigate changes in mental representation from either random or blocked practice when engaged in golf putting. Thirty participants were randomly assigned to random practice, blocked practice, and no-practice groups. First, we measured novice golfers' initial mental representation levels and required them to perform 18 putting trials as a pre-test. We then asked random and blocked groups to practice in accordance with their group assignment for six consecutive days (10 blocks each day, 18 trials each). A week after the last practice session, we re-measured all participants' final mental representation levels and required them to perform 18 putting trials to evaluate learning retention through practice. While those engaged in the random practice method putted more poorly during acquisition (i.e., practice) than those in blocked practice, the random practice group experienced more accurate retention during the final putting trials, and they showed a more structured mental representation than those in blocked practice, one that was more similar to that of skilled golfers. These results support the acquisition of a rich mental representation through random versus blocked practice.

Aerobic exercise for Alzheimer's disease: A randomized controlled pilot trial

PubMed Central

Van Sciver, Angela; Mahnken, Jonathan D.; Honea, Robyn A.; Brooks, William M.; Billinger, Sandra A.; Swerdlow, Russell H.; Burns, Jeffrey M.

2017-01-01

Background There is increasing interest in the role of physical exercise as a therapeutic strategy for individuals with Alzheimer’s disease (AD). We assessed the effect of 26 weeks (6 months) of a supervised aerobic exercise program on memory, executive function, functional ability and depression in early AD. Methods and findings This study was a 26-week randomized controlled trial comparing the effects of 150 minutes per week of aerobic exercise vs. non-aerobic stretching and toning control intervention in individuals with early AD. A total of 76 well-characterized older adults with probable AD (mean age 72.9 [7.7]) were enrolled and 68 participants completed the study. Exercise was conducted with supervision and monitoring by trained exercise specialists. Neuropsychological tests and surveys were conducted at baseline,13, and 26 weeks to assess memory and executive function composite scores, functional ability (Disability Assessment for Dementia), and depressive symptoms (Cornell Scale for Depression in Dementia). Cardiorespiratory fitness testing and brain MRI was performed at baseline and 26 weeks. Aerobic exercise was associated with a modest gain in functional ability (Disability Assessment for Dementia) compared to individuals in the ST group (X2 = 8.2, p = 0.02). There was no clear effect of intervention on other primary outcome measures of Memory, Executive Function, or depressive symptoms. However, secondary analyses revealed that change in cardiorespiratory fitness was positively correlated with change in memory performance and bilateral hippocampal volume. Conclusions Aerobic exercise in early AD is associated with benefits in functional ability. Exercise-related gains in cardiorespiratory fitness were associated with improved memory performance and reduced hippocampal atrophy, suggesting cardiorespiratory fitness gains may be important in driving brain benefits. Trial registration ClinicalTrials.gov NCT01128361 PMID:28187125

Functional Brain Connectivity as a New Feature for P300 Speller.

PubMed

Kabbara, Aya; Khalil, Mohamad; El-Falou, Wassim; Eid, Hassan; Hassan, Mahmoud

2016-01-01

The brain is a large-scale complex network often referred to as the "connectome". Cognitive functions and information processing are mainly based on the interactions between distant brain regions. However, most of the 'feature extraction' methods used in the context of Brain Computer Interface (BCI) ignored the possible functional relationships between different signals recorded from distinct brain areas. In this paper, the functional connectivity quantified by the phase locking value (PLV) was introduced to characterize the evoked responses (ERPs) obtained in the case of target and non-targets visual stimuli. We also tested the possibility of using the functional connectivity in the context of 'P300 speller'. The proposed approach was compared to the well-known methods proposed in the state of the art of "P300 Speller", mainly the peak picking, the area, time/frequency based features, the xDAWN spatial filtering and the stepwise linear discriminant analysis (SWLDA). The electroencephalographic (EEG) signals recorded from ten subjects were analyzed offline. The results indicated that phase synchrony offers relevant information for the classification in a P300 speller. High synchronization between the brain regions was clearly observed during target trials, although no significant synchronization was detected for a non-target trial. The results showed also that phase synchrony provides higher performance than some existing methods for letter classification in a P300 speller principally when large number of trials is available. Finally, we tested the possible combination of both approaches (classical features and phase synchrony). Our findings showed an overall improvement of the performance of the P300-speller when using Peak picking, the area and frequency based features. Similar performances were obtained compared to xDAWN and SWLDA when using large number of trials.

Emotion Recognition from Single-Trial EEG Based on Kernel Fisher's Emotion Pattern and Imbalanced Quasiconformal Kernel Support Vector Machine

PubMed Central

Liu, Yi-Hung; Wu, Chien-Te; Cheng, Wei-Teng; Hsiao, Yu-Tsung; Chen, Po-Ming; Teng, Jyh-Tong

2014-01-01

Electroencephalogram-based emotion recognition (EEG-ER) has received increasing attention in the fields of health care, affective computing, and brain-computer interface (BCI). However, satisfactory ER performance within a bi-dimensional and non-discrete emotional space using single-trial EEG data remains a challenging task. To address this issue, we propose a three-layer scheme for single-trial EEG-ER. In the first layer, a set of spectral powers of different EEG frequency bands are extracted from multi-channel single-trial EEG signals. In the second layer, the kernel Fisher's discriminant analysis method is applied to further extract features with better discrimination ability from the EEG spectral powers. The feature vector produced by layer 2 is called a kernel Fisher's emotion pattern (KFEP), and is sent into layer 3 for further classification where the proposed imbalanced quasiconformal kernel support vector machine (IQK-SVM) serves as the emotion classifier. The outputs of the three layer EEG-ER system include labels of emotional valence and arousal. Furthermore, to collect effective training and testing datasets for the current EEG-ER system, we also use an emotion-induction paradigm in which a set of pictures selected from the International Affective Picture System (IAPS) are employed as emotion induction stimuli. The performance of the proposed three-layer solution is compared with that of other EEG spectral power-based features and emotion classifiers. Results on 10 healthy participants indicate that the proposed KFEP feature performs better than other spectral power features, and IQK-SVM outperforms traditional SVM in terms of the EEG-ER accuracy. Our findings also show that the proposed EEG-ER scheme achieves the highest classification accuracies of valence (82.68%) and arousal (84.79%) among all testing methods. PMID:25061837

Emotion recognition from single-trial EEG based on kernel Fisher's emotion pattern and imbalanced quasiconformal kernel support vector machine.

PubMed

Liu, Yi-Hung; Wu, Chien-Te; Cheng, Wei-Teng; Hsiao, Yu-Tsung; Chen, Po-Ming; Teng, Jyh-Tong

2014-07-24

Electroencephalogram-based emotion recognition (EEG-ER) has received increasing attention in the fields of health care, affective computing, and brain-computer interface (BCI). However, satisfactory ER performance within a bi-dimensional and non-discrete emotional space using single-trial EEG data remains a challenging task. To address this issue, we propose a three-layer scheme for single-trial EEG-ER. In the first layer, a set of spectral powers of different EEG frequency bands are extracted from multi-channel single-trial EEG signals. In the second layer, the kernel Fisher's discriminant analysis method is applied to further extract features with better discrimination ability from the EEG spectral powers. The feature vector produced by layer 2 is called a kernel Fisher's emotion pattern (KFEP), and is sent into layer 3 for further classification where the proposed imbalanced quasiconformal kernel support vector machine (IQK-SVM) serves as the emotion classifier. The outputs of the three layer EEG-ER system include labels of emotional valence and arousal. Furthermore, to collect effective training and testing datasets for the current EEG-ER system, we also use an emotion-induction paradigm in which a set of pictures selected from the International Affective Picture System (IAPS) are employed as emotion induction stimuli. The performance of the proposed three-layer solution is compared with that of other EEG spectral power-based features and emotion classifiers. Results on 10 healthy participants indicate that the proposed KFEP feature performs better than other spectral power features, and IQK-SVM outperforms traditional SVM in terms of the EEG-ER accuracy. Our findings also show that the proposed EEG-ER scheme achieves the highest classification accuracies of valence (82.68%) and arousal (84.79%) among all testing methods.

Concurrent Stereotactic Radiosurgery and Bevacizumab in Recurrent Malignant Gliomas: A Prospective Trial

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

Cabrera, Alvin R.; Cuneo, Kyle C.; Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan

2013-08-01

Purpose: Virtually all patients with malignant glioma (MG) eventually recur. This study evaluates the safety of concurrent stereotactic radiosurgery (SRS) and bevacizumab (BVZ), an antiangiogenic agent, in treatment of recurrent MG. Methods and Materials: Fifteen patients with recurrent MG, treated at initial diagnosis with surgery and adjuvant radiation therapy/temozolomide and then at least 1 salvage chemotherapy regimen, were enrolled in this prospective trial. Lesions <3 cm in diameter were treated in a single fraction, whereas those 3 to 5 cm in diameter received 5 5-Gy fractions. BVZ was administered immediately before SRS and 2 weeks later. Neurocognitive testing (Mini-Mental Statusmore » Exam, Trail Making Test A/B), Functional Assessment of Cancer Therapy-Brain (FACT-Br) quality-of-life assessment, physical exam, and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were performed immediately before SRS and 1 week and 2 months following completion of SRS. The primary endpoint was central nervous system (CNS) toxicity. Secondary endpoints included survival, quality of life, microvascular properties as measured by DCE-MRI, steroid usage, and performance status. Results: One grade 3 (severe headache) and 2 grade 2 CNS toxicities were observed. No patients experienced grade 4 to 5 toxicity or intracranial hemorrhage. Neurocognition, quality of life, and Karnofsky performance status did not change significantly with treatment. DCE-MRI results suggest a significant decline in tumor perfusion and permeability 1 week after SRS and further decline by 2 months. Conclusions: Treatment of recurrent MG with concurrent SRS and BVZ was not associated with excessive toxicity in this prospective trial. A randomized trial of concurrent SRS/BVZ versus conventional salvage therapy is needed to establish the efficacy of this approach.« less

Correcting for multiple-testing in multi-arm trials: is it necessary and is it done?

PubMed

Wason, James M S; Stecher, Lynne; Mander, Adrian P

2014-09-17

Multi-arm trials enable the evaluation of multiple treatments within a single trial. They provide a way of substantially increasing the efficiency of the clinical development process. However, since multi-arm trials test multiple hypotheses, some regulators require that a statistical correction be made to control the chance of making a type-1 error (false-positive). Several conflicting viewpoints are expressed in the literature regarding the circumstances in which a multiple-testing correction should be used. In this article we discuss these conflicting viewpoints and review the frequency with which correction methods are currently used in practice. We identified all multi-arm clinical trials published in 2012 by four major medical journals. Summary data on several aspects of the trial design were extracted, including whether the trial was exploratory or confirmatory, whether a multiple-testing correction was applied and, if one was used, what type it was. We found that almost half (49%) of published multi-arm trials report using a multiple-testing correction. The percentage that corrected was higher for trials in which the experimental arms included multiple doses or regimens of the same treatments (67%). The percentage that corrected was higher in exploratory than confirmatory trials, although this is explained by a greater proportion of exploratory trials testing multiple doses and regimens of the same treatment. A sizeable proportion of published multi-arm trials do not correct for multiple-testing. Clearer guidance about whether multiple-testing correction is needed for multi-arm trials that test separate treatments against a common control group is required.

Analysing Time to Event Data in Dementia Prevention Trials: The Example of the GuidAge Study of EGb761.

PubMed

Scherrer, B; Andrieu, S; Ousset, P J; Berrut, G; Dartigues, J F; Dubois, B; Pasquier, F; Piette, F; Robert, P; Touchon, J; Garnier, P; Mathiex-Fortunet, H; Vellas, B

2015-12-01

Time-to-event analysis is frequently used in medical research to investigate potential disease-modifying treatments in neurodegenerative diseases. Potential treatment effects are generally evaluated using the logrank test, which has optimal power and sensitivity when the treatment effect (hazard ratio) is constant over time. However, there is generally no prior information as to how the hazard ratio for the event of interest actually evolves. In these cases, the logrank test is not necessarily the most appropriate to use. When the hazard ratio is expected to decrease or increase over time, alternative statistical tests such as the Fleming-Harrington test, provide a better sensitivity. An example of this comes from a large, five-year randomised, placebo-controlled prevention trial (GuidAge) in 2854 community-based subjects making spontaneous memory complaints to their family physicians, which evaluated whether treatment with EGb761 can modify the risk of developing AD. The primary outcome measure was the time to conversion from memory complaint to Alzheimer's type dementia. Although there was no significant difference in the hazard function of conversion between the two treatment groups according to the preplanned logrank test, a significant treatment-by-time interaction for the incidence of AD was observed in a protocol-specified subgroup analysis, suggesting that the hazard ratio is not constant over time. For this reason, additional post hoc analyses were performed using the Fleming-Harrington test to evaluate whether there was a signal of a late effect of EGb761. Applying the Fleming-Harrington test, the hazard function for conversion to dementia in the placebo group was significantly different from that in the EGb761 treatment group (p = 0.0054), suggesting a late effect of EGb761. Since this was a post hoc analysis, no definitive conclusions can be drawn as to the effectiveness of the treatment. This post hoc analysis illustrates the interest of performing another randomised clinical trial of EGb761 explicitly testing the hypothesis of a late treatment effect, as well as of using of better adapted statistical approaches for long term preventive trials when it is expected that prevention cannot have an immediate effect but rather a delayed effect that increases over time.

Intensive client-centred occupational therapy in the home improves older adults' occupational performance. Results from a Danish randomized controlled trial.

PubMed

Nielsen, Tove Lise; Andersen, Niels Trolle; Petersen, Kirsten Schultz; Polatajko, Helene; Nielsen, Claus Vinther

2018-01-12

There is growing interest in enabling older adults' occupational performance. We tested whether 11 weeks of intensive client-centred occupational therapy (ICC-OT) was superior to usual practice in improving the occupational performance of home-dwelling older adults. An assessor-masked randomized controlled trial among adults 60 + with chronic health issues, who received or applied for homecare services. Recruitment took place September 2012 to April 2014. All participants received practical and personal assistance and meal delivery as needed. In addition, they were randomized to receive either a maximum 22 sessions of occupation-based ICC-OT (N = 59) or to receive usual practice with a maximum three sessions of occupational therapy (N = 60). The primary outcome was self-rated occupational performance assessed with the Canadian Occupational Performance Measure (COPM). No important adverse events occurred. ICC-OT was accepted by 46 participants (88%), usual practice by 60 (100%). After 3 months, the ICC-OT-group had improved 1.86 points on COPM performance; the Usual-Practice group had improved 0.61 points. The between-group difference was statistically significant (95% confidence interval 0.50 to 2.02), t-test: p = 0.001. ICC-OT improved older adults' occupational performance more effectively than usual practice. This result may benefit older adults and support programmatic changes.

The role of source memory in gambling task decision making.

PubMed

Whitney, Paul; Hinson, John M

2012-01-01

The role of memory in the Iowa Gambling Task (IGT) was tested in two experiments that dissociated item memory (memory for losses obtained) from source memory (the deck that produced a given loss). In Experiment 1, participants observed 75 choices that had been made by controls or patients in previous research, followed by memory tests, and then 25 active choices from the participant. In Experiment 2, participants made choices for 75 trials, performed the memory tests, and then made 25 final choices. The data show that item and source memory can diverge within the IGT, and that source memory makes a significant contribution to IGT performance.

Energy saving by using asymmetric aftbodies for merchant ships-design methodology, numerical simulation and validation

NASA Astrophysics Data System (ADS)

Dang, Jie; Chen, Hao

2016-12-01

The methodology and procedures are discussed on designing merchant ships to achieve fully-integrated and optimized hull-propulsion systems by using asymmetric aftbodies. Computational fluid dynamics (CFD) has been used to evaluate the powering performance through massive calculations with automatic deformation algorisms for the hull forms and the propeller blades. Comparative model tests of the designs to the optimized symmetric hull forms have been carried out to verify the efficiency gain. More than 6% improvement on the propulsive efficiency of an oil tanker has been measured during the model tests. Dedicated sea-trials show good agreement with the predicted performance from the test results.

Skill execution and sleep deprivation: effects of acute caffeine or creatine supplementation - a randomized placebo-controlled trial

PubMed Central

2011-01-01

Background We investigated the effects of sleep deprivation with or without acute supplementation of caffeine or creatine on the execution of a repeated rugby passing skill. Method Ten elite rugby players completed 10 trials on a simple rugby passing skill test (20 repeats per trial), following a period of familiarisation. The players had between 7-9 h sleep on 5 of these trials and between 3-5 h sleep (deprivation) on the other 5. At a time of 1.5 h before each trial, they undertook administration of either: placebo tablets, 50 or 100 mg/kg creatine, 1 or 5 mg/kg caffeine. Saliva was collected before each trial and assayed for salivary free cortisol and testosterone. Results Sleep deprivation with placebo application resulted in a significant fall in skill performance accuracy on both the dominant and non-dominant passing sides (p < 0.001). No fall in skill performance was seen with caffeine doses of 1 or 5 mg/kg, and the two doses were not significantly different in effect. Similarly, no deficit was seen with creatine administration at 50 or 100 mg/kg and the performance effects were not significantly different. Salivary testosterone was not affected by sleep deprivation, but trended higher with the 100 mg/kg creatine dose, compared to the placebo treatment (p = 0.067). Salivary cortisol was elevated (p = 0.001) with the 5 mg/kg dose of caffeine (vs. placebo). Conclusion Acute sleep deprivation affects performance of a simple repeat skill in elite athletes and this was ameliorated by a single dose of either caffeine or creatine. Acute creatine use may help to alleviate decrements in skill performance in situations of sleep deprivation, such as transmeridian travel, and caffeine at low doses appears as efficacious as higher doses, at alleviating sleep deprivation deficits in athletes with a history of low caffeine use. Both options are without the side effects of higher dose caffeine use. PMID:21324203

Skill execution and sleep deprivation: effects of acute caffeine or creatine supplementation - a randomized placebo-controlled trial.

PubMed

Cook, Christian J; Crewther, Blair T; Kilduff, Liam P; Drawer, Scott; Gaviglio, Chris M

2011-02-16

We investigated the effects of sleep deprivation with or without acute supplementation of caffeine or creatine on the execution of a repeated rugby passing skill. Ten elite rugby players completed 10 trials on a simple rugby passing skill test (20 repeats per trial), following a period of familiarisation. The players had between 7-9 h sleep on 5 of these trials and between 3-5 h sleep (deprivation) on the other 5. At a time of 1.5 h before each trial, they undertook administration of either: placebo tablets, 50 or 100 mg/kg creatine, 1 or 5 mg/kg caffeine. Saliva was collected before each trial and assayed for salivary free cortisol and testosterone. Sleep deprivation with placebo application resulted in a significant fall in skill performance accuracy on both the dominant and non-dominant passing sides (p < 0.001). No fall in skill performance was seen with caffeine doses of 1 or 5 mg/kg, and the two doses were not significantly different in effect. Similarly, no deficit was seen with creatine administration at 50 or 100 mg/kg and the performance effects were not significantly different. Salivary testosterone was not affected by sleep deprivation, but trended higher with the 100 mg/kg creatine dose, compared to the placebo treatment (p = 0.067). Salivary cortisol was elevated (p = 0.001) with the 5 mg/kg dose of caffeine (vs. placebo). Acute sleep deprivation affects performance of a simple repeat skill in elite athletes and this was ameliorated by a single dose of either caffeine or creatine. Acute creatine use may help to alleviate decrements in skill performance in situations of sleep deprivation, such as transmeridian travel, and caffeine at low doses appears as efficacious as higher doses, at alleviating sleep deprivation deficits in athletes with a history of low caffeine use. Both options are without the side effects of higher dose caffeine use.

Personal navigation increases colorectal cancer screening uptake.

PubMed

Ritvo, Paul G; Myers, Ronald E; Paszat, Lawrence F; Tinmouth, Jill M; McColeman, Joshua; Mitchell, Brian; Serenity, Mardie; Rabeneck, Linda

2015-03-01

Prior randomized, controlled trials (RCTs) indicate that patient navigation can boost colorectal cancer screening rates in primary care. The sparse literature on pragmatic trials of interventions designed to increase colorectal cancer screening adherence motivated this trial on the impact of a patient navigation intervention that included support for performance of the participants' preferred screening test (colonoscopy or stool blood testing). Primary care patients (n = 5,240), 50 to 74 years of age, with no prior diagnosis of bowel cancer and no record of a recent colorectal cancer screening test, were identified at the Group Health Centre in northern Ontario. These patients were randomly assigned to an intervention group (n = 2,629) or a usual care control group (n = 2,611). Intervention group participants were contacted by a trained nurse navigator by telephone to discuss colorectal cancer screening. Interested patients met with the navigator, who helped them identify and arrange for performance of the preferred screening test. Control group participants received usual care. Multivariate analyses were conducted using medical records data to assess intervention impact on screening adherence within 12 months after randomization. Mean patient age was 59 years, and 50% of participants were women. Colorectal cancer screening adherence was higher in the intervention group (35%) than in the control group (20%), a difference that was statistically significant (OR, 2.11; confidence interval, 1.87-2.39). Preference-based patient navigation increased screening uptake in a pragmatic RCT. Patient navigation increased colorectal cancer screening rates in a pragmatic RCT in proportions similar to those observed in explanatory RCTs. ©2014 American Association for Cancer Research.

The effect of chronic progressive-dose sodium bicarbonate ingestion on CrossFit-like performance: A double-blind, randomized cross-over trial.

PubMed

Durkalec-Michalski, Krzysztof; Zawieja, Emilia E; Podgórski, Tomasz; Łoniewski, Igor; Zawieja, Bogna E; Warzybok, Marta; Jeszka, Jan

2018-01-01

Sodium bicarbonate (SB) has been proposed as an ergogenic aid, as it improves high-intensity and resistance exercise performance. However, no studies have yet investigated SB application in CrossFit. This study examined the effects of chronic, progressive-dose SB ingestion on CrossFit-like performance and aerobic capacity. In a randomized, double-blind, cross-over trial, 21 CrossFit-trained participants were randomly allocated to 2 groups and underwent 2 trials separated by a 14-day washout period. Participants ingested either up to 150 mg∙kg-1 of SB in a progressive-dose regimen or placebo for 10 days. Before and after each trial, Fight Gone Bad (FGB) and incremental cycling (ICT) tests were performed. In order to examine biochemical responses, blood samples were obtained prior to and 3 min after completing each exercise test. No gastrointestinal (GI) side effects were reported during the entire protocol. The overall FGB performance improved under SB by ~6.1% (p<0.001) and it was ~3.1% higher compared to post placebo (PLApost) (p = 0.040). The number of repetitions completed in each round also improved under SB (mean from baseline: +5.8% to +6.4%). Moreover, in ICT, the time to ventilatory threshold (VT) (~8:25 min SBpost vs. ~8:00 min PLApost, p = 0.020), workload at VT (~218 W SBpost vs. ~208 W PLApost, p = 0.037) and heart rate at VT (~165 bpm SBpost vs. ~161 bpm PLApost, p = 0.030) showed higher SBpost than PLApost. Furthermore, the maximum carbon dioxide production increased under SB by ~4.8% (from ~3604 mL∙min-1 to ~3776 mL∙min-1, p = 0.049). Pyruvate concentration and creatine kinase activity before ICT showed higher SBpost than PLApost (~0.32 mmol∙L-1 vs. ~0.26 mmol∙L-1, p = 0.001; ~275 U∙L-1 vs. ~250 U∙L-1, p = 0.010, respectively). However, the small sample size limits the wide-application of our results. Progressive-dose SB ingestion regimen eliminated GI side effects and improved CrossFit-like performance, as well as delayed ventilatory threshold occurrence.

Heat training increases exercise capacity in hot but not in temperate conditions: a mechanistic counter-balanced cross-over study.

PubMed

Keiser, Stefanie; Flück, Daniela; Hüppin, Fabienne; Stravs, Alexander; Hilty, Matthias P; Lundby, Carsten

2015-09-01

The aim was to determine the mechanisms facilitating exercise performance in hot conditions following heat training. In a counter-balanced order, seven males (V̇o2max 61.2 ± 4.4 ml·min(-1)·kg(-1)) were assigned to either 10 days of 90-min exercise training in 18 or 38°C ambient temperature (30% relative humidity) applying a cross-over design. Participants were tested for V̇o2max and 30-min time trial performance in 18 (T18) and 38°C (T38) before and after training. Blood volume parameters, sweat output, cardiac output (Q̇), cerebral perfusion (i.e., middle cerebral artery velocity [MCAvmean]), and other variables were determined. Before one set of exercise tests in T38, blood volume was acutely expanded by 538 ± 16 ml with an albumin solution (T38A) to determine the role of acclimatization induced hypervolemia on exercise performance. We furthermore hypothesized that heat training would restore MCAvmean and thereby limit centrally mediated fatigue. V̇o2max and time trial performance were equally reduced in T38 and T38A (7.2 ± 1.6 and 9.3 ± 2.5% for V̇o2max; 12.8 ± 2.8 and 12.9 ± 2.8% for time trial). Following heat training both were increased in T38 (9.6 ± 2.1 and 10.4 ± 3.1%, respectively), whereas both V̇o2max and time trial performance remained unchanged in T18. As expected, heat training augmented plasma volume (6 ± 2%) and mean sweat output (26 ± 6%), whereas sweat [Na(+)] became reduced by 19 ± 7%. In T38 Q̇max remained unchanged before (21.3 ± 0.6 l/min) to after (21.7 ± 0.5 l/min) training, whereas MCAvmean was increased by 13 ± 10%. However, none of the observed adaptations correlated with the concomitant observed changes in exercise performance. Copyright © 2015 the American Physiological Society.

Effect of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in the heat.

PubMed

Beaumont, Ross E; James, Lewis J

2017-11-01

This study investigated the influence of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in high ambient temperature. Double-blind cross-over study. Eight healthy, recreationally active males (mean±SD; age: 22±1 years; body mass: 71.1±8.5kg; VO 2peak : 55.9±5.8mLkg -1 min -1 ; W max : 318±37W) completed one VO 2peak test, one familiarisation trial and two experimental trials. After an overnight fast, participants ingested a placebo or a 6mgkg -1 caffeine dose 60min before exercise. The exercise protocol consisted of 60min of cycle exercise at 55% W max , followed by a 30min performance task (total kJ produced) in 30°C and 50% RH. Performance was enhanced (Cohen's d effect size=0.22) in the caffeine trial (363.8±47.6kJ) compared with placebo (353.0±49.0kJ; p=0.004). Caffeine did not influence core (p=0.188) or skin temperature (p=0.577) during exercise. Circulating prolactin (p=0.572), cortisol (p=0.842) and the estimated rates of fat (p=0.722) and carbohydrate oxidation (p=0.454) were also similar between trial conditions. Caffeine attenuated perceived exertion during the initial 60min of exercise (p=0.033), with no difference in thermal stress across trials (p=0.911). Supplementation with 6mgkg -1 caffeine improved endurance cycle performance in a warm environment, without differentially influencing thermoregulation during prolonged exercise at a fixed work-rate versus placebo. Therefore, moderate caffeine doses which typically enhance performance in temperate environmental conditions also appear to benefit endurance performance in the heat. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The next generation of sepsis trials: What’s next after the demise of recombinant human activated Protein C?

PubMed Central

Opal, Steven M.; Dellinger, R. Phillip; Vincent, Jean-Louis; Masur, Henry; Angus, Derek C.

2014-01-01

Progress in the development of novel therapeutics to treat sepsis has come to virtual standstill. While enormous strides have been made in the understanding of basic molecular mechanisms that underlie the pathophysiology of sepsis, a distressingly long list of novel therapeutic agents have been tested in large clinical trials over the past 25 years without a single, specific, immunomodulating agent showing consistent benefit in sepsis trials. The only novel anti-sepsis agent to successfully complete a phase 3 sepsis trial, human recombinant activated protein C, was recently taken off the market after a follow up placebo-controlled trial (PROWESS SHOCK) failed to replicate the results of the initial registration trial (PROWESS) performed 10 yr earlier. We must critically re-examine our basic approach in the preclinical and clinical evaluation of new sepsis therapies. We propose 12 specific recommendations that if implemented could improve the outlook for developing new drugs for sepsis. PMID:24717456

Effect of oral nitrate supplementation on pulmonary hemodynamics during exercise and time trial performance in normoxia and hypoxia: a randomized controlled trial

PubMed Central

Bourdillon, Nicolas; Fan, Jui-Lin; Uva, Barbara; Müller, Hajo; Meyer, Philippe; Kayser, Bengt

2015-01-01

Background: Hypoxia-induced pulmonary vasoconstriction increases pulmonary arterial pressure (PAP) and may impede right heart function and exercise performance. This study examined the effects of oral nitrate supplementation on right heart function and performance during exercise in normoxia and hypoxia. We tested the hypothesis that nitrate supplementation would attenuate the increase in PAP at rest and during exercise in hypoxia, thereby improving exercise performance. Methods: Twelve trained male cyclists [age: 31 ± 7 year (mean ± SD)] performed 15 km time-trial cycling (TT) and steady-state submaximal cycling (50, 100, and 150 W) in normoxia and hypoxia (11% inspired O2) following 3-day oral supplementation with either placebo or sodium nitrate (0.1 mmol/kg/day). We measured TT time-to-completion, muscle tissue oxygenation during TT and systolic right ventricle to right atrium pressure gradient (RV-RA gradient: index of PAP) during steady state cycling. Results: During steady state exercise, hypoxia elevated RV-RA gradient (p > 0.05), while oral nitrate supplementation did not alter RV-RA gradient (p > 0.05). During 15 km TT, hypoxia lowered muscle tissue oxygenation (p < 0.05). Nitrate supplementation further decreased muscle tissue oxygenation during 15 km TT in hypoxia (p < 0.05). Hypoxia impaired time-to-completion during TT (p < 0.05), while no improvements were observed with nitrate supplementation in normoxia or hypoxia (p > 0.05). Conclusion: Our findings indicate that oral nitrate supplementation does not attenuate acute hypoxic pulmonary vasoconstriction nor improve performance during time trial cycling in normoxia and hypoxia. PMID:26528189

The Efficacy of a Pre-Workout Vegan Supplement on High-Intensity Cycling Performance in Healthy College-Aged Males.

PubMed

Gallien, Gabrielle; Bellar, David; Davis, Greggory R

2017-11-02

There is a limited supply of sport nutrition supplements currently available for vegan or vegetarian athletes. In addition, the efficacy of a vegan or vegetarian pre-workout supplement that does not contain any processed ingredients or stimulants is currently unknown. The purpose of the current study was to examine the effects of an unprocessed vegan pre-workout supplement on high-intensity cycling performance. Participants completed three separate cycling trials following the consumption of a vegan pre-workout supplement, an isocaloric processed supplement, or a zero-calorie placebo supplement. Each supplement was consumed 30 minutes prior to each trial, and each cycling trial was separated by a minimum of 72 hours. Supplements were administered using a randomized, double-blind cross-over design. Each cycling trial was performed at a workload equal to 80% VO 2peak until exhaustion. The average time in seconds (s) until exhaustion values for the vegan, isocaloric, and zero-calorie supplements were 482 ± 163, 480 ± 157, and 496 ± 238, respectively. Consumption of the vegan supplement did not significantly improve performance compared to an isocaloric and zero-calorie supplement (F = 0.12, p =.89). The results of this study indicate that individuals who choose a vegan pre-workout supplement (over an isocaloric or zero-calorie product) will not experience any acute decrements or ergogenic benefits in cycling performance. Although the present study does not support performance benefits of the tested vegan pre-workout supplement before cycling, additional research examining various exercise intensities and modalities is warranted.

Normative values for the unipedal stance test with eyes open and closed.

PubMed

Springer, Barbara A; Marin, Raul; Cyhan, Tamara; Roberts, Holly; Gill, Norman W

2007-01-01

Limited normative data are available for the unipedal stance test (UPST), making it difficult for clinicians to use it confidently to detect subtle balance impairments. The purpose of this study was to generate normative values for repeated trials of the UPST with eyes opened and eyes closed across age groups and gender. This prospective, mixed-model design was set in a tertiary care medical center. Healthy subjects (n= 549), 18 years or older, performed the UPST with eyes open and closed. Mean and best of 3 UPST times for males and females of 6 age groups (18-39, 40-49, 50-59, 60-69, 70-79, and 80+) were documented and inter-rater reliability was tested. There was a significant age dependent decrease in UPST time during both conditions. Inter-rater reliability for the best of 3 trials was determined to be excellent with an intra-class correlation coefficient of 0.994 (95% confidence interval 0.989-0.996) for eyes open and 0.998 (95% confidence interval 0.996-0.999) for eyes closed. This study adds to the understanding of typical performance on the UPST. Performance is age-specific and not related to gender. Clinicians now have more extensive normative values to which individuals can be compared.

Comparison of learning ability and memory retention in altricial (Bengalese finch, Lonchura striata var. domestica) and precocial (blue-breasted quail, Coturnix chinensis) birds using a color discrimination task.

PubMed

Ueno, Aki; Suzuki, Kaoru

2014-02-01

The present study sought to assess the potential application of avian models with different developmental modes to studies on cognition and neuroscience. Six altricial Bengalese finches (Lonchura striata var. domestica), and eight precocial blue-breasted quails (Coturnix chinensis) were presented with color discrimination tasks to compare their respective faculties for learning and memory retention within the context of the two developmental modes. Tasks consisted of presenting birds with discriminative cues in the form of colored feeder lids, and birds were considered to have learned a task when 80% of their attempts at selecting the correctly colored lid in two consecutive blocks of 10 trials were successful. All of the finches successfully performed the required experimental tasks, whereas only half of the quails were able to execute the same tasks. In the learning test, finches required significantly fewer trials than quails to learn the task (finches: 13.5 ± 9.14 trials, quails: 45.8 ± 4.35 trials, P < 0.05), with finches scoring significantly more correct responses than quails (finches: 98.3 ± 4.08%, quails: 85.0 ± 5.77% at the peak of the learning curve). In the memory retention tests, which were conducted 45 days after the learning test, finches retained the ability to discriminate between colors correctly (95.0 ± 4.47%), whereas quails did not retain any memory of the experimental procedure and so could not be tested. These results suggested that altricial and precocial birds both possess the faculty for learning and retaining discrimination-type tasks, but that altricial birds perform better than precocial birds in both faculties. The present findings imply that developmental mode is an important consideration for assessing the suitability of bird species for particular experiments. © 2013 Japanese Society of Animal Science.

Correlation between perceptual, visuo-spatial, and psychomotor aptitude to duration of training required to reach performance goals on the MIST-VR surgical simulator.

PubMed

McClusky, D A; Ritter, E M; Lederman, A B; Gallagher, A G; Smith, C D

2005-01-01

Given the dynamic nature of modern surgical education, determining factors that may improve the efficiency of laparoscopic training is warranted. The objective of this study was to analyze whether perceptual, visuo-spatial, or psychomotor aptitude are related to the amount of training required to reach specific performance-based goals on a virtual reality surgical simulator. Sixteen MS4 medical students participated in an elective skills course intended to train laparoscopic skills. All were tested for perceptual, visuo-spatial, and psychomotor aptitude using previously validated psychological tests. Training involved as many instructor-guided 1-hour sessions as needed to reach performance goals on a custom designed MIST-VR manipulation-diathermy task (Mentice AB, Gothenberg, Sweden). Thirteen subjects reached performance goals by the end of the course. Two were excluded from analysis due to previous experience with the MIST-VR (total n = 11). Perceptual ability (r = -0.76, P = 0.007) and psychomotor skills (r = 0.62, P = 0.04) significantly correlated with the number of trials required. Visuo-spatial ability did not significantly correlate with training duration. The number of trials required to train subjects to performance goals on the MIST-VR manipulation diathermy task is significantly related to perceptual and psychomotor aptitude.

Video- or text-based e-learning when teaching clinical procedures? A randomized controlled trial.

PubMed

Buch, Steen Vigh; Treschow, Frederik Philip; Svendsen, Jesper Brink; Worm, Bjarne Skjødt

2014-01-01

This study investigated the effectiveness of two different levels of e-learning when teaching clinical skills to medical students. Sixty medical students were included and randomized into two comparable groups. The groups were given either a video- or text/picture-based e-learning module and subsequently underwent both theoretical and practical examination. A follow-up test was performed 1 month later. The students in the video group performed better than the illustrated text-based group in the practical examination, both in the primary test (P<0.001) and in the follow-up test (P<0.01). Regarding theoretical knowledge, no differences were found between the groups on the primary test, though the video group performed better on the follow-up test (P=0.04). Video-based e-learning is superior to illustrated text-based e-learning when teaching certain practical clinical skills.

Preliminary Report on Oak Ridge National Laboratory Testing of Drake/ACSS/MA2/E3X

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

Irminger, Philip; King, Daniel J.; Herron, Andrew N.

2016-01-01

A key to industry acceptance of a new technology is extensive validation in field trials. The Powerline Conductor Accelerated Test facility (PCAT) at Oak Ridge National Laboratory (ORNL) is specifically designed to evaluate the performance and reliability of a new conductor technology under real world conditions. The facility is set up to capture large amounts of data during testing. General Cable used the ORNL PCAT facility to validate the performance of TransPowr with E3X Technology a standard overhead conductor with an inorganic high emissivity, low absorptivity surface coating. Extensive testing has demonstrated a significant improvement in conductor performance across amore » wide range of operating temperatures, indicating that E3X Technology can provide a reduction in temperature, a reduction in sag, and an increase in ampacity when applied to the surface of any overhead conductor. This report provides initial results of that testing.« less

Video- or text-based e-learning when teaching clinical procedures? A randomized controlled trial

PubMed Central

Buch, Steen Vigh; Treschow, Frederik Philip; Svendsen, Jesper Brink; Worm, Bjarne Skjødt

2014-01-01

Background and aims This study investigated the effectiveness of two different levels of e-learning when teaching clinical skills to medical students. Materials and methods Sixty medical students were included and randomized into two comparable groups. The groups were given either a video- or text/picture-based e-learning module and subsequently underwent both theoretical and practical examination. A follow-up test was performed 1 month later. Results The students in the video group performed better than the illustrated text-based group in the practical examination, both in the primary test (P<0.001) and in the follow-up test (P<0.01). Regarding theoretical knowledge, no differences were found between the groups on the primary test, though the video group performed better on the follow-up test (P=0.04). Conclusion Video-based e-learning is superior to illustrated text-based e-learning when teaching certain practical clinical skills. PMID:25152638

High-frequency welding trials.

PubMed

Kelch, R

2000-09-01

The high-frequency weldability of a new family of polyolefin films is compared with that of conventional films made of other polymers. A comparison of the optimum weld parameters of all the films and the results of performance testing of all the pouches produced are reported.

Exercise training for intermittent claudication.

PubMed

McDermott, Mary M

2017-11-01

The objective of this study was to provide an overview of evidence regarding exercise therapies for patients with lower extremity peripheral artery disease (PAD). This manuscript summarizes the content of a lecture delivered as part of the 2016 Crawford Critical Issues Symposium. Multiple randomized clinical trials demonstrate that supervised treadmill exercise significantly improves treadmill walking performance in people with PAD and intermittent claudication symptoms. A meta-analysis of 25 randomized trials demonstrated a 180-meter increase in treadmill walking distance in response to supervised exercise interventions compared with a nonexercising control group. Supervised treadmill exercise has been inaccessible to many patients with PAD because of lack of medical insurance coverage. However, in 2017, the Centers for Medicare and Medicaid Services issued a decision memorandum to support health insurance coverage of 12 weeks of supervised treadmill exercise for patients with walking impairment due to PAD. Recent evidence also supports home-based walking exercise to improve walking performance in people with PAD. Effective home-exercise programs incorporate behavioral change interventions such as a remote coach, goal setting, and self-monitoring. Supervised treadmill exercise programs preferentially improve treadmill walking performance, whereas home-based walking exercise programs preferentially improve corridor walking, such as the 6-minute walk test. Clinical trial evidence also supports arm or leg ergometry exercise to improve walking endurance in people with PAD. Treadmill walking exercise appears superior to resistance training alone for improving walking endurance. Supervised treadmill exercise significantly improves treadmill walking performance in people with PAD by approximately 180 meters compared with no exercise. Recent evidence suggests that home-based exercise is also effective and preferentially improves over-ground walking performance, such as the 6-minute walk test. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.