Relative Reliabilities Research Articles

Reliability of behavioral tests in the middle cerebral artery occlusion model of rat.

Stroke is one of the leading causes of death and disability worldwide, and its incidence is increasing. To overcome impairment from stroke, translational research for developing new therapeutic technologies has been conducted and middle cerebral artery occlusion (MCAo) in rat is the representative model. Since recovery from neurological impairment in contralateral limbs caused by brain damage is the major goal of treatment, behavioral tests that assess the relevant function are used. To determine therapeutic effect, obtaining reliable results of behavioral assessment is a prerequisite. However, studies on the reliability of behavioral tests in the MCAo rat model and necessity of prior training have not yet been reported. In this study, the authors investigate relative and absolute inter-rater reliabilities of modified neurological severity score (mNSS), cylinder test, and grid-walking test before training and repeated training every week until the reliability of results reached a satisfactory level. The training included repeated learning of the scoring system and decreasing disagreements among the raters. For MCAo modeling, adult male Sprague-Dawley rats were subjected to 90 min of transient MCAo. Six raters conducted behavioral tests via observation of video-recording on sham-operated and MCAo model rats at 3 or 7 days after the intervention. An independent experimenter randomly numbered each video clip to blind the experiment. The results of reliabilities were unacceptable before training and improved to a satisfactory level after 6 weeks of training in all of the tests. In conclusion, mNSS, cylinder test, and grid-walking test on the MCAo rat model are reliable evaluation methods after conducting appropriate training.

Relative and absolute test-retest reliabilities of pressure pain threshold in patients with knee osteoarthritis.

Pressure pain threshold (PPT) and PPT maps are commonly used to quantify and visualize mechanical pain sensitivity. Although PPT's have frequently been reported from patients with knee osteoarthritis (KOA), the absolute and relative reliability of PPT assessments remain to be determined. Thus, the purpose of this study was to evaluate the test-retest relative and absolute reliability of PPT in KOA. For that purpose, intra- and interclass correlation coefficient (ICC) as well as the standard error of measurement (SEM) and the minimal detectable change (MDC) values within eight anatomical locations covering the most painful knee of KOA patients was measured. Twenty KOA patients participated in two sessions with a period of 2 weeks±3 days apart. PPT's were assessed over eight anatomical locations covering the knee and two remote locations over tibialis anterior and brachioradialis. The patients rated their maximum pain intensity during the past 24 h and prior to the recordings on a visual analog scale (VAS), and completed The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and PainDetect surveys. The ICC, SEM and MDC between the sessions were assessed. The ICC for the individual variability was expressed with coefficient of variance (CV). Bland-Altman plots were used to assess potential bias in the dataset. The ICC ranged from 0.85 to 0.96 for all the anatomical locations which is considered "almost perfect". CV was lowest in session 1 and ranged from 44.2 to 57.6%. SEM for comparison ranged between 34 and 71 kPa and MDC ranged between 93 and 197 kPa with a mean PPT ranged from 273.5 to 367.7 kPa in session 1 and 268.1-331.3 kPa in session 2. The analysis of Bland-Altman plot showed no systematic bias. PPT maps showed that the patients had lower thresholds in session 2, but no significant difference was observed for the comparison between the sessions for PPT or VAS. No correlations were seen between PainDetect and PPT and PainDetect and WOMAC. Almost perfect relative and absolute reliabilities were found for the assessment of PPT's for KOA patients. The present investigation implicates that PPT's is reliable for assessing pain sensitivity and sensitization in KOA patients.

A mass-density model can account for the size-weight illusion.

When judging the heaviness of two objects with equal mass, people perceive the smaller and denser of the two as being heavier. Despite the large number of theories, covering bottom-up and top-down approaches, none of them can fully account for all aspects of this size-weight illusion and thus for human heaviness perception. Here we propose a new maximum-likelihood estimation model which describes the illusion as the weighted average of two heaviness estimates with correlated noise: One estimate derived from the object’s mass, and the other from the object’s density, with estimates’ weights based on their relative reliabilities. While information about mass can directly be perceived, information about density will in some cases first have to be derived from mass and volume. However, according to our model at the crucial perceptual level, heaviness judgments will be biased by the objects’ density, not by its size. In two magnitude estimation experiments, we tested model predictions for the visual and the haptic size-weight illusion. Participants lifted objects which varied in mass and density. We additionally varied the reliability of the density estimate by varying the quality of either visual (Experiment 1) or haptic (Experiment 2) volume information. As predicted, with increasing quality of volume information, heaviness judgments were increasingly biased towards the object’s density: Objects of the same density were perceived as more similar and big objects were perceived as increasingly lighter than small (denser) objects of the same mass. This perceived difference increased with an increasing difference in density. In an additional two-alternative forced choice heaviness experiment, we replicated that the illusion strength increased with the quality of volume information (Experiment 3). Overall, the results highly corroborate our model, which seems promising as a starting point for a unifying framework for the size-weight illusion and human heaviness perception.

Trapezius viscoelastic properties are heterogeneously affected by eccentric exercise

ObjectivesThe aim of this study was to investigate the influence of eccentric exercise (ECC) on the spatial mapping of muscle stiffness and creep of the upper trapezius, using a quantitative myotonometry device. DesignTwo groups of 16 subjects participated in the experimental sessions. In part A, the test–retest reliabilities of muscle stiffness and creep were assessed. In part B, muscle stiffness and muscle creep were mapped before, immediately after and 24h after ECC when post-exercise soreness had developed. MethodsThe ECC protocol consisted of 50 eccentric contractions divided into 5 bouts of 10 contractions at maximum force level. ResultsThe relative reliabilities of stiffness and creep measurements were found to be substantial to almost perfect. Muscle stiffness for musculotendinous sites increased at 24h after ECC while it decreased for muscle belly immediately after and 24h after ECC. Muscle creep for musculotendinous sites decreased, and for muscle belly sites increased, immediately after and 24h after ECC. ConclusionsFor the first time, the present study showed sign of discrepancies in the effects of ECC on muscle stiffness and creep, underlining opposite changes in the musculotendinous and muscle belly viscoelastic properties of upper trapezius.

Relative and absolute test-retest reliabilities of biomechanical risk factors for knee osteoarthritis progression: benchmarks for meaningful change.

Biomechanical factors are important treatment targets in knee osteoarthritis. The knee adduction (KAM) and flexion (KFM) moments, quadriceps strength and power, load frequency, and body mass index (BMI) all have the potential to affect knee articular cartilage integrity by modulating forces across the joint. To identify clinically meaningful change, however, these measurements must be reliable and sensitive to change. This study estimated relative and absolute test-retest reliabilities over long periods of biomechanical risk factors for knee osteoarthritis progression. Data from a longitudinal, observational study were analyzed for knee osteoarthritis patients with data at baseline, 6-month and 24-month follow-ups. Gait kinematics and kinetics, quadriceps strength and power, daily load frequency and BMI were collected. Relative and absolute test-retest reliabilities of these measures were estimated using intraclass correlation coefficients (ICCs) and standard errors of measurement (SEMs), respectively. Minimal detectable change at the 95% confidence level (MDC95) was also calculated. Data from 46 participants [36 women; age 61.0 (6.6) years] were included. Good-to-excellent relative reliabilities (ICC≥0.80) indicated that KAM peak and impulse, quadriceps strength and power, and BMI had a strong ability to discriminate amongst participants. Absolute reliabilities were high for quadriceps strength and BMI, which demonstrated reasonable within-participant variability (SEMs≤11% of the mean). The MDC95 values supported use of clinical interventions effective in reducing BMI and KAM, and increasing quadriceps strength. These data are useful in interpreting findings from interventional or longitudinal investigations by determining whether observed changes are beyond measurement error and interpretable as true change.

The reliability and minimal detectable change of the cardiovascular response and self-selected exercise intensity during forward and backward treadmill exercise in individuals with Parkinson disease.

Objective:This study examined test–retest relative (intraclass correlation coefficient) and absolute (minimum detectable change) reliabilities for heart rate, blood pressure, rate of perceived exertion, and the cerebral oxygen response during both forward and backward treadmill walking in clients with Parkinson disease. In addition, the intensity of exercise based on the individual’s heart rate response during forward and backward walking treadmill work was assessed.Design:Test–retest reliability study.Subjects:A total of 22 clients with Parkinson disease (Hoehn and Yahr stages 1–3).Main measures:Outcome measures of heart rate, blood pressure, and cerebral oxygen response were assessed during forward and backward walking on a treadmill for a total of 20 minutes up to an intensity based on the clients’ prior treadmill work and their rate of perceived exertion.Results:Good to excellent 6–8 day test–retest findings for both forward (intraclass correlation coefficient(2,1), 0.89–0.99) and backward (intraclass correlation coefficient(2,1), 0.82–0.99) treadmill walking were found for heart rate, blood pressure, cerebral oxygen response, and the participants’ rate of perceived exertion. Low minimum detectable change (MDC)95 values were found for heart rate (4.9 and 4.8), rate of perceived exertion (1.0 and 1.6), and cerebral oxygen response (1.2 and 0.92), during forward and backward walking, respectively. All treadmill exercise heart rates attained by participants were within an intensity of 54%–87% of the client’s predicted maximal heart rate.Conclusion:Treadmill exercise training can be included in Parkinson disease exercise programs with relative confidence in test–retest reliability of cardiovascular response. It was also demonstrated that individuals with Parkinson disease previously involved with exercise consistently self-select walking speeds which induce heart rates within recommended guidelines for positive cardiovascular adaptation.

How reliable are GCM simulations for different atmospheric variables?

Considerable variability exists in simulations of the future climate. This variability is caused by differences in the parameterisations across general circulation models (GCMs), the initial conditions used and the different assumptions made as to how emissions will evolve in the future. As a result, there is considerable disagreement between available projections of climate variables, which can be used to quantify the uncertainty each variable exhibits. This leads to the question—which variables (or set of variables) are more reliable for use in climate change impact assessments. This research presents a framework to quantify the relative reliability amongst a range of upper air atmospheric variables. This is made possible by pooling simulations across multiple models, trajectories (scenarios) and initial conditions in a rank-transformed space. A metric named the variable reliability score (VRS) assesses the relative reliabilities across different atmospheric variables on a common scale. The VRS has been applied to calculate the total reliability as well as reliability from each source of uncertainty, namely model, scenarios and initial conditions. This comparison helps to decide if more models, scenarios or ensembles are required for uncertainty analysis of climate change impact assessment.

Reliability and Minimal Detectable Change for Sit-to-Stand Tests and the Functional Gait Assessment for Individuals With Parkinson Disease.

This study examined test-retest relative (intraclass correlation coefficient [ICC]) and absolute (minimum detectable change [MDC]) reliabilities for the 5 times sit-to-stand (5×STS), 30-second sit-to-stand (30sSTS), and the functional gait assessment (FGA) tests in people with Parkinson disease (PD). In addition, correlation of these functional tests with a history of falls was examined over a 6-month period, and the internal consistency of the FGA was established. Twenty-two patients with PD (Hoehn and Yahr stages 1-3) completed 3 functional tests over 2 test-retest periods of 6 to 8 days. Falls were self-reported for the prior 6 months. Moderate-to-excellent test-retest ICC(2,2) and MDC95 values were found for the 30sSTS (0.94, 3 times) and ICC(2,1) and MDC95 values were found for the FGA (0.86, 4 points). The 5×STS demonstrated a lower ICC(2,2) and a high MDC95 value (0.74, 10 seconds). A significant correlation was only found between past falls and the FGA test (r =-0.48, P < .05) during session 1. Cronbach α values for the 10-item FGA during session 1 and session 2 were 0.75 and 0.85, respectively. To assess for change over time, we found the 30sSTS and the FGA tests can be used reliably in patients with PD. A lower FGA score was associated with a higher chance of falls, and good internal consistency of the FGA was found.

Perceptual attraction in tool use: evidence for a reliability-based weighting mechanism.

Humans are well able to operate tools whereby their hand movement is linked, via a kinematic transformation, to a spatially distant object moving in a separate plane of motion. An everyday example is controlling a cursor on a computer monitor. Despite these separate reference frames, the perceived positions of the hand and the object were found to be biased toward each other. We propose that this perceptual attraction is based on the principles by which the brain integrates redundant sensory information of single objects or events, known as optimal multisensory integration. That is, 1) sensory information about the hand and the tool are weighted according to their relative reliability (i.e., inverse variances), and 2) the unisensory reliabilities sum up in the integrated estimate. We assessed whether perceptual attraction is consistent with optimal multisensory integration model predictions. We used a cursor-control tool-use task in which we manipulated the relative reliability of the unisensory hand and cursor position estimates. The perceptual biases shifted according to these relative reliabilities, with an additional bias due to contextual factors that were present in experiment 1 but not in experiment 2 The biased position judgments' variances were, however, systematically larger than the predicted optimal variances. Our findings suggest that the perceptual attraction in tool use results from a reliability-based weighting mechanism similar to optimal multisensory integration, but that certain boundary conditions for optimality might not be satisfied.NEW & NOTEWORTHY Kinematic tool use is associated with a perceptual attraction between the spatially separated hand and the effective part of the tool. We provide a formal account for this phenomenon, thereby showing that the process behind it is similar to optimal integration of sensory information relating to single objects.

Relative and Absolute Interrater Reliabilities of a Hand-Held Myotonometer to Quantify Mechanical Muscle Properties in Patients with Acute Stroke in an Inpatient Ward.

Introduction The reliability of using MyotonPRO to quantify muscles mechanical properties in a ward setting for the acute stroke population remains unknown. Aims To investigate the within-session relative and absolute interrater reliability of MyotonPRO. Methods Mechanical properties of biceps brachii, brachioradialis, rectus femoris, and tibialis anterior were recorded at bedside. Participants were within 1 month of the first occurrence of stroke. Relative reliability was assessed by intraclass correlation coefficient (ICC). Absolute reliability was assessed by standard error of measurement (SEM), SEM%, smallest real difference (SRD), SRD%, and the Bland-Altman 95% limits of agreement. Results ICCs of all studied muscles ranged between 0.63 and 0.97. The SEM of all muscles ranged within 0.30–0.88 Hz for tone, 0.07–0.19 for decrement, 6.42–20.20 N/m for stiffness, and 0.04–0.07 for creep. The SRD of all muscles ranged within 0.70–2.05 Hz for tone, 0.16–0.45 for decrement, 14.98–47.15 N/m for stiffness, and 0.09–0.17 for creep. Conclusions MyotonPRO demonstrated acceptable relative and absolute reliability in a ward setting for patients with acute stroke. However, results must be interpreted with caution, due to the varying level of consistency between different muscles, as well as between different parameters within a muscle.

Is One Trial Sufficient to Obtain Excellent Pressure Pain Threshold Reliability in the Low Back of Asymptomatic Individuals? A Test-Retest Study.

The assessment of pressure pain threshold (PPT) provides a quantitative value related to the mechanical sensitivity to pain of deep structures. Although excellent reliability of PPT has been reported in numerous anatomical locations, its absolute and relative reliability in the lower back region remains to be determined. Because of the high prevalence of low back pain in the general population and because low back pain is one of the leading causes of disability in industrialized countries, assessing pressure pain thresholds over the low back is particularly of interest. The purpose of this study study was (1) to evaluate the intra- and inter- absolute and relative reliability of PPT within 14 locations covering the low back region of asymptomatic individuals and (2) to determine the number of trial required to ensure reliable PPT measurements. Fifteen asymptomatic subjects were included in this study. PPTs were assessed among 14 anatomical locations in the low back region over two sessions separated by one hour interval. For the two sessions, three PPT assessments were performed on each location. Reliability was assessed computing intraclass correlation coefficients (ICC), standard error of measurement (SEM) and minimum detectable change (MDC) for all possible combinations between trials and sessions. Bland-Altman plots were also generated to assess potential bias in the dataset. Relative reliability for both intra- and inter- session was almost perfect with ICC ranged from 0.85 to 0.99. With respect to the intra-session, no statistical difference was reported for ICCs and SEM regardless of the conducted comparisons between trials. Conversely, for inter-session, ICCs and SEM values were significantly larger when two consecutive PPT measurements were used for data analysis. No significant difference was observed for the comparison between two consecutive measurements and three measurements. Excellent relative and absolute reliabilities were reported for both intra- and inter-session. Reliable measurements can be equally achieved when using the mean of two or three consecutive PPT measurements, as usually proposed in the literature, or with only the first one. Although reliability was almost perfect regardless of the conducted comparison between PPT assessments, our results suggest using two consecutive measurements to obtain higher short term absolute reliability.

Relative and Absolute Reliabilities of the Conners' Continuous Performance Test II in Schizophrenia.

The Conners' Continuous Performance Test II (CCPT-II) is one of the most commonly used tests of sustained attention in schizophrenia. To manage and monitor sustained attention deficits in schizophrenia, clinicians have to reliably assess the degree of attention impairment. The purpose of our study was to determine the relative and absolute reliability of the CCPT-II in schizophrenia. The final sample was a total of 108 patients with schizophrenia. The primary measures in this study were the CCPT-II and the Clinical Global Impression-Severity (CGI-S). The CCPT-II was administered twice, 1 month apart, by a specially trained occupational therapist. We assessed two types of reliability: relative and absolute reliability. Relative reliability was determined with the intra-class correlation coefficient (ICC). Absolute reliability was quantified with standard error of measurement (SEM), minimal detectable change (MDC), and Bland-Altman's 95% limits of agreement (LOA). The ICCs for the five CCPT-II indexes (Omissions, Commissions, Hit RT, Hit RT Std Error, and Variability) ranged from 0.66 to 0.79. The MDCs (MDC%) of the five indices were 13.53 (156.78), 10.67 (47.85), 122.10 (34.16), 8.15 (106.82), and 25.81 (162.63), respectively. According to the results, the CCPT-II has limited reliability in monitoring the sustained attention function of patients with schizophrenia. Our results can be used as a reference for the measurement error of CCPT-II to help clinicians and researchers determine the true change between successive assessments of patients with schizophrenia.

Reliability, Validity, and Ability to Identify Fall Status of the Balance Evaluation Systems Test, Mini–Balance Evaluation Systems Test, and Brief–Balance Evaluation Systems Test in Older People Living in the Community

ObjectivesTo assess the reliability, validity, and ability to identify fall status of the Balance Evaluation Systems Test (BESTest), Mini-BESTest, and Brief-BESTest, compared with the Berg Balance Scale (BBS), in older people living in the community. DesignCross-sectional. SettingCommunity centers. ParticipantsOlder adults (N=122; mean age ± SD, 76±9y). InterventionsNot applicable. Main Outcome MeasuresParticipants reported on falls history in the preceding year and completed the Activities-Specific Balance Confidence (ABC) Scale. The BBS, BESTest, and the Five Times Sit-To-Stand Test were administered. Interrater (2 physiotherapists) and test-retest relative (48–72h) and absolute reliabilities were explored with the intraclass correlation coefficient (ICC) equation (2,1) and the Bland and Altman method. Minimal detectable changes at the 95% confidence level (MDC95) were established. Validity was assessed by correlating the balance tests with each other and with the ABC Scale (Spearman correlation coefficients–ρ). Receiver operating characteristics assessed the ability of each balance test to differentiate between people with and without a history of falls. ResultsAll balance tests presented good to excellent interrater (ICC=.71–.93) and test-retest (ICC=.50–.82) relative reliability, with no evidence of bias. MDC95 values were 4.6, 9, 3.8, and 4.1 points for the BBS, BESTest, Mini-BESTest, and Brief-BESTest, respectively. All tests were significantly correlated with each other (ρ=.83–.96) and with the ABC Scale (ρ=.46–.61). Acceptable ability to identify fall status (areas under the curve, .71–.78) was found for all tests. Cutoff points were 48.5, 82, 19.5, and 12.5 points for the BBS, BESTest, Mini-BESTest, and Brief-BESTest, respectively. ConclusionsAll balance tests are reliable, valid, and able to identify fall status in older people living in the community. Therefore, the choice of which test to use will depend on the level of balance impairment, purpose, and time availability.

A New Agility Test for Adults: Its Test–Retest Reliability and Minimal Detectable Change in Untrained Women and Men Aged 28–55

Manderoos, SA, Vaara, ME, Mäki, PJ, Mälkiä, EA, Aunola, SK, and Karppi, S-L. A new agility test for adults: its test-retest reliability and minimal detectable change in untrained women and men aged 28-55. J Strength Cond Res 30(8): 2226-2234, 2016-The aims of this study were to present a new Agility Test for Adults (ATA), to investigate its test-retest reliability and to quantify minimal detectable change at the 95% confidence interval (MDC95). Both the relative and absolute reliabilities were evaluated. Altogether 52 healthy untrained volunteers (25 women: age 43.3 ± 6.6 years; 27 men: age 42.8 ± 7.2 years) were recruited into the study. The subjects performed 3 ATA tests repeated after 2 different intervals: the first test session was baseline, session 2 was a week later, and session 3 was half an hour after session 2. The intraclass correlation coefficient and the SEM of the performance time of ATA were 0.91 and 0.27 seconds (same day), 0.94 and 0.20 seconds (1 week) for women, and 0.95, 0.13 seconds, and 0.94, 0.19 seconds for men, respectively. MDC95 was 0.76 seconds (same day) and 0.56 seconds (1 week) for women, and respectively 0.37 and 0.51 seconds for men. The results showed that ATA is stable and reliable when evaluating agility characteristics in untrained adults. The properties of ATA make it appropriate for screening people to find early signs of declined agility and allow possibility to clinicians and physical trainers to monitor true changes in performance time at agility test by applying the knowledge of MDC95 coefficient. Furthermore, ATA can give tips for planning appropriate exercise programes to prevent clumsiness and falls with more serious consequences among aging people.

The Development of Audio-Visual Integration for Temporal Judgements.

Adults combine information from different sensory modalities to estimate object properties such as size or location. This process is optimal in that (i) sensory information is weighted according to relative reliability: more reliable estimates have more influence on the combined estimate and (ii) the combined estimate is more reliable than the component uni-modal estimates. Previous studies suggest that optimal sensory integration does not emerge until around 10 years of age. Younger children rely on a single modality or combine information using inappropriate sensory weights. Children aged 4–11 and adults completed a simple audio-visual task in which they reported either the number of beeps or the number of flashes in uni-modal and bi-modal conditions. In bi-modal trials, beeps and flashes differed in number by 0, 1 or 2. Mutual interactions between the sensory signals were evident at all ages: the reported number of flashes was influenced by the number of simultaneously presented beeps and vice versa. Furthermore, for all ages, the relative strength of these interactions was predicted by the relative reliabilities of the two modalities, in other words, all observers weighted the signals appropriately. The degree of cross-modal interaction decreased with age: the youngest observers could not ignore the task-irrelevant modality—they fully combined vision and audition such that they perceived equal numbers of flashes and beeps for bi-modal stimuli. Older observers showed much smaller effects of the task-irrelevant modality. Do these interactions reflect optimal integration? Full or partial cross-modal integration predicts improved reliability in bi-modal conditions. In contrast, switching between modalities reduces reliability. Model comparison suggests that older observers employed partial integration, whereas younger observers (up to around 8 years) did not integrate, but followed a sub-optimal switching strategy, responding according to either visual or auditory information on each trial.

Effects of Reliability and Global Context on Explicit and Implicit Measures of Sensed Hand Position in Cursor-Control Tasks.

In a cursor-control task in which the motion of the cursor is rotated randomly relative to the movement of the hand, the sensed directions of hand and cursor are mutually biased. In our previous study, we used implicit and explicit measures of the bias of sensed hand direction toward the direction of the cursor and found different characteristics. The present study serves to explore further differences and commonalities of these measures. In Experiment 1, we examined the effects of different relative reliabilities of visual and proprioceptive information on the explicitly and implicitly assessed bias of sensed hand direction. In two conditions, participants made an aiming movement and returned to the start position immediately or after a delay of 6 s during which the cursor was no longer visible. The unimodal proprioceptive information on final hand position in the delayed condition served to increase its relative reliability. As a result, the bias of sensed hand direction toward the direction of the cursor was reduced for the explicit measure, with a complementary increase of the bias of sensed cursor direction, but unchanged for the implicit measure. In Experiment 2, we examined the influence of global context, specifically of the across-trial sequence of judgments of hand and cursor direction. Both explicitly and implicitly assessed biases of sensed hand direction did not significantly differ between the alternated condition (trial-to-trial alternations of judgments of hand and cursor direction) and the blocked condition (judgments of hand or cursor directions in all trials). They both substantially decreased from the alternated to the randomized condition (random sequence of judgments of hand and cursor direction), without a complementary increase of the bias of sensed cursor direction. We conclude that our explicit and implicit measures are equally sensitive to variations of coupling strength as induced by the variation of global context in Experiment 2, but are differently sensitive to variations of the relative reliabilities as induced by our additional unimodal proprioceptive information in Experiment 1.

Reliability and sensitivity to change of the timed standing balance test in children with down syndrome.

Objective:To estimate the reliability and sensitivity to change of the timed standing balance test in children with Down syndrome (DS).Methods:It was a nonblinded, comparison study with a convenience sample of subjects consisting of children with DS (n = 9) aged 8–17 years. The main outcome measure was standing balance which was assessed using timed standing balance test, the time required to maintain in four conditions, eyes open static, eyes closed static, eyes open dynamic, and eyes closed dynamic.Results:Relative reliability was excellent for all four conditions with an Interclass Correlation Coefficient (ICC) ranging from 0.91 to 0.93. The variation between repeated measurements for each condition was minimal with standard error of measurement (SEM) of 0.21–0.59 s, suggestive of excellent absolute reliability. The sensitivity to change as measured by smallest real change (SRC) was 1.27 s for eyes open static, 1.63 s for eyes closed static, 0.58 s for eyes open dynamic, and 0.61 s for eyes closed static.Conclusions:Timed standing balance test is an easy to administer test and sensitive to change with strong absolute and relative reliabilities, an important first step in establishing its utility as a clinical balance measure in children with DS.

Trans-saccadic integration of peripheral and foveal feature information is close to optimal.

Due to the inhomogenous visual representation across the visual field, humans use peripheral vision to select objects of interest and foveate them by saccadic eye movements for further scrutiny. Thus, there is usually peripheral information available before and foveal information after a saccade. In this study we investigated the integration of information across saccades. We measured reliabilities--i.e., the inverse of variance-separately in a presaccadic peripheral and a postsaccadic foveal orientation--discrimination task. From this, we predicted trans-saccadic performance and compared it to observed values. We show that the integration of incongruent peripheral and foveal information is biased according to their relative reliabilities and that the reliability of the trans-saccadic information equals the sum of the peripheral and foveal reliabilities. Both results are consistent with and indistinguishable from statistically optimal integration according to the maximum-likelihood principle. Additionally, we tracked the gathering of information around the time of the saccade with high temporal precision by using a reverse correlation method. Information gathering starts to decline between 100 and 50 ms before saccade onset and recovers immediately after saccade offset. Altogether, these findings show that the human visual system can effectively use peripheral and foveal information about object features and that visual perception does not simply correspond to disconnected snapshots during each fixation.

Synthesis, Crystal Structure, Absolute Configuration and Antitumor Activity of the Enantiomers of 5-Bromo-2-chloro-N-(1-phenylethyl)pyridine-3-sulfonamide.

Pyridinesulfonamide is an important fragment which has a wide range of applications in novel drugs. R- and S-isomers of 5-bromo-2-chloro-N-(1-phenylethyl)pyridine-3-sulfonamide have been synthesized, and the stereostructures have been researched. Single crystals of both compounds were obtained for X-ray analysis, and the absolute configurations (ACs) have been further confirmed by electronic circular dichroism (ECD), optical rotation (OR) and quantum chemical calculations. The crystal structures and calculated geometries were extremely similar, which permitted a comparison of the relative reliabilities of ACs obtained by ECD analyses and theoretical simulation. In addition, the effect of stereochemistry on the PI3Kα kinase and anticancer activity were investigated. Compounds 10a and 10b inhibit the activity of PI3Kα kinase with IC50 values of 1.08 and 2.69 μM, respectively. Furthermore, molecular docking was performed to analyze the binding modes of R- and S-isomers.

Endocannabinoids and related lipids in blood plasma following touch massage: a randomised, crossover study.

BackgroundThe endocannabinoid system is involved in the regulation of stress and anxiety. In a recent study, it was reported that short-term changes in mood produced by a pleasant ambience were correlated with changes in the levels of plasma endocannabinoids and related N-acylethanolamines (Schrieks et al. PLoS One 10: e0126421, 2015). In the present study, we investigated whether stress reduction by touch massage (TM) affects blood plasma levels of endocannabinoids and related N-acylethanolamines.ResultsA randomized two-session crossover design for 20 healthy participants was utilised, with one condition that consisted of TM and a rest condition as control. TM increased the perceived pleasantness rating of the participants, and both TM and rest reduced the basal anxiety level as assessed by the State scale of the STAI-Y inventory. However, there were no significant effects of either time (pre- vs. post-treatment measures) as main effect or the interaction time x treatment for the plasma levels of the endocannabinoids anandamide and 2-arachidonoylglycerol or for eight other related lipids. Four lipids showed acceptable relative reliabilities, and for two of these (linoleoyl ethanolamide and palmitoleoyl ethanolamide) a significant correlation was seen between the TM-related change in levels, calculated as (post-TM value minus pre-TM value) − (post-rest value minus pre-rest value), and the corresponding TM-related change in perceived pleasantness.ConclusionsIt is concluded that in the participants studied here, there are no overt effects of TM upon plasma endocannabinoid levels. Possible associations of related N-acylethanolamines with the perceived pleasantness should be investigated further.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1450-z) contains supplementary material, which is available to authorized users.