Reliability and validity of a new repeated agility test as a measure of anaerobic and explosive power

The aim of this study was to evaluate the reliability and validity of a repeated modified agility test (RMAT) to assess anaerobic power and explosiveness. Twenty-seven subjects (age: 20.2 ± 0.9 years, body mass: 66.1 ± 6.0 kg, height: 176 ± 6 cm, and body fat: 11.4 ± 2.6%) participated in this study. After familiarization, subjects completed the RMAT consisting of 10 × 20-m maximal running performances (moving in forward, lateral, and backward) with ~25-second recovery between each run. Ten subjects performed the RMAT twice separated by at least 48 hours to evaluate relative and absolute reliability and usefulness of the test. The criterion validity of the RMAT was determined by examining the relationship between RMAT indices and the Wingate anaerobic test (WAT) performances and both vertical and horizontal jumps. Reliability of the total time (TT) and peak time (PT) of the RMAT was very good, with intraclass correlation coefficient > 0.90 and SEM < 5% and low bias. The usefulness of TT and PT of the RMAT was rated as "good" and "OK," respectively. The TT of the RMAT had significant correlations with the WAT (peak power: r = -0.44; mean power: r = -0.72), vertical jumps (squat jump: r = -0.50; countermovement jump: r = -0.61; drop jump (DJ): r = -0.55; DJ with dominant leg: r = -0.72; DJ with nondominant leg: r = -0.53) and 5 jump test (r = -0.56). These findings suggest that the RMAT is a reliable and valid test for assessing anaerobic power and explosiveness in multisprint sport athletes. Consequently, the RMAT is an easily applied, inexpensive field test and can provide coaches and strength and conditioning professionals with relevant information concerning the choice and the efficacy of training programs.     

The effect of neck muscle fatigue on shoulder humeral rotation joint position sense

IntroductionCervical extensor muscle (CEM) fatigue causes decrements in upper limb proprioceptive accuracy during constrained single-joint tasks. This study used a novel humeral rotation joint position sense (JPS) measurement device to compare JPS accuracy in participants who received acute CEM fatigue vs. non-fatigued controls.MethodsParticipants had vision occluded and were passively guided into postures of internal humeral rotation from a baseline posture before and after a CEM fatigue or control protocol. Mixed model repeated measures ANOVAs were used to verify fatigue and compared absolute, constant, and variable JPS error between groups.ResultsCEM fatigue was verified via pre-post reduction in CEM strength, and myoelectric indicators of fatigue. However, between-group comparisons of absolute, constant, and variable JPS error were not statistically significant, despite having large effect sizes.DiscussionContrary to prevailing literature, unconstrained humeral rotation JPS did not appear to be affected by CEM fatigue in this study. However, between-group differences in JPS error were dwarfed by inter-trial variability, which likely arose due to the unconstrained nature of this task, conflating chances for a Type II error. Future research should perform a kinematic analysis of task constraints to highlight potential compensatory mechanisms obscuring significant findings in this otherwise robust effect.     

The ZZP Questionnaire. Reliability of a new resource utilization measure

Data to determine the resource utilization of care recipients need to be reliable and the items that are measured need to be useful. In 2006, the Dutch Ministry of Health and Welfare has mandated all nursing homes and homes for the elderly to measure the Resource Utilization of all residents with the ZZP Questionnaire. Are the data resulting from this measurement reliable and is each of the 54 items of the ZZP Questionnaire useful? To answer this we tested the reliability of the data in a nursing home and a home for the elderly in two wards each. For 122 residents questionnaires were completed such that the inter- and intra-rater reliability of the answers could be assessed. Ten of the 54 items in the questionnaire showed insufficient inter rater reliability (<0.40) on the weighted Cohen kappa and another sixteen moderate (0.40 - 0.60). On the intra rater reliability test seven items had an insufficient kappa and another fifteen moderate. Besides, ten clusters of items could be formed with in-cluster Spearman correlation rates of .75 or higher. From the results of the reliability tests and the item intercorrelation rates we concluded that a substantial number of items needs to be improved and that in the ZZP Questionnaire 15 of the 54 items appear to be redundant on statistical grounds.     

Reliability of a method to measure novelty-seeking in nonhuman primates

The objective of this study was to create a reliable method to measure novelty-seeking (NS) temperament in stumptailed macaques. We correlated two behavioral indexes (risk-taking and curiosity) with the NS index. Cochran's concordance index yielded ethogram reliability (risk: alpha = 0.88; curiosity: alpha = 0.79). Risk and curiosity indexes were obtained with a synthetic index obtainment approach. Intraclass correlation of the instrument yielded a value of 0.88. Temperament index was established from the average score given by each judge. The instrument presented 92% specificity and 70% sensitivity, with a 56-point score taken as the cuttoff point to classify individuals. The results of a Spearman's analysis of the three indexes were significant (temperament-risk, n = 32, P<0.01; temperament-curiosity, n = 29, P<0.05; risk curiosity, n = 29, P<0.05). We conclude that the method we developed is reliable.     

A new method to elicit and measure movement illusions in stroke by means of muscle tendon vibration: the Standardized Kinesthetic Illusion Procedure (SKIP)

Abstract

Purpose: Muscle tendon vibration (MTV) strongly activates muscle spindles and can evoke kinaesthetic illusions. Although potentially relevant for sensorimotor rehabilitation in stroke, MTV is scarcely used in clinical practice, likely because of the absence of standardised procedures to elicit and characterise movement illusions. This work developed and validated a Standardised Kinaesthetic Illusion Procedure (SKIP) to favour the use of MTV-induced illusions in clinical settings.

Materials and methods: SKIP scores were obtained in 15 individuals with chronic stroke and 18 age- and gender-matched healthy counterparts. A further 13 healthy subjects were tested to provide more data with the general population. MTV was applied over the Achilles tendon and SKIP scoring system characterised the clearness and direction of the illusions of ankle dorsiflexion movements.

Results: All healthy and stroke participants perceived movement illusions. SKIP scores on the paretic side were significantly lower compared to the non paretic and healthy. Illusions were less clear and sometimes in unexpected directions with the impaired ankle, but still possible to elicit in the presence of sensorimotor deficits.

Conclusions: SKIP represents an ancillary and potentially useful clinical method to elicit and characterise illusions of movements induced by MTV. SKIP could be relevant to further assess the processing of proprioceptive afferents in stroke and their potential impact on motor control and recovery. It may be used to guide therapy and improve sensorimotor recovery. Future work is needed to investigate the metrological properties of our method (reliability, responsiveness, etc.), and also the neurophysiological underpinnings of MTV-induced illusions.     

薄层细胞涂片新方法在宫颈细胞学检查中应用的研究

目的：研究一种新的宫颈细胞薄层涂片方法,以提高传统手工涂片方法的制片质量。方法：随机选择的妇科门诊病人100例,随机分成2组,薄层细胞涂片组和手工涂片组,其中薄层细胞涂片组的刮片标本经过我们设计的双层滤网的过滤和分离液离心的步骤去除标本中的黏液、炎细胞和血细胞。这两组得到的涂片根据其细胞分布的均匀度及细胞重叠的多少,把涂片的结果分为满意、基本满意和不满意。结果：薄层细胞涂片组的涂片质量满意率（98％）高于手工涂片组的涂片质量满意程度（32％．P〈0．01）。讨论：薄层细胞涂片法在宫颈细胞学检查中的满意程度明显好于传统手工涂片（P〈0．01）,有统计学意义。效果稳定,适合在大范围内推广。薄层细胞涂片法相对于传统手工涂片有5大优点,大大提高了宫颈细胞学诊断的准确性。     

A review of methods to assess coactivation in the spine

Coactivation is an important component for understanding the physiological cost of muscular and spinal loads and their associations with spinal pathology and potentially myofascial pain. However, due to the complex and dynamic nature of most activities of daily living, it can be difficult to capture a quantifiable measure of coactivation. Many methods exist to assess coactivation, but most are limited to two-muscle systems, isometric/complex analyses, or dynamic/uniplanar analyses. Hence, a void exists in that coactivation has not been documented or assessed as a multiple-muscle system under realistic complex dynamic loading. Overall, no coactivation index has been capable of assessing coactivation during complex dynamic exertions. The aim of this review is to provide an understanding of the factors that may influence coactivation, document the metrics used to assess coactivity, assess the feasibility of those metrics, and define the necessary variables for a coactivation index that can be used for a variety of tasks. It may also be clinically and practically relevant in the understanding of rehabilitation effectiveness, efficiency during task performance, human-task interactions, and possibly the etiology for a multitude of musculoskeletal conditions.     

Experimental analysis of the lower cervical spine in flexion with a focus on facet tracking

Cervical traumas are among the most common events leading to serious spinal cord injuries. While models are often used to better understand injury mechanisms, experimental data for their validation remain sparse, particularly regarding articular facets. The aim of this study was to assess the behavior of cervical FSUs under quasi-static flexion with a specific focus on facet tracking. 9 cadaveric cervical FSUs were imaged and loaded under a 10 Nm flexion moment, exerted incrementally, while biplanar X-rays were acquired at each load increment. The relative vertebral and facet rotations and displacements were assessed using radio-opaque markers implanted in each vertebra and CT-based reconstructions registered on the radiographs. The only failures obtained were due to specimen preparation, indicating a failure moment of cervical FSUs greater than 10 Nm in quasistatic flexion. Facet motions displayed a consistent anterior sliding and a variable pattern regarding their normal displacement. The present study offers insight on the behavior of cervical FSUs under quasi-static flexion beyond physiological thresholds with accurate facet tracking. The data provided should prove useful to further understand injury mechanisms and validate models.     

Cluster formation as a measure of interpretability in multiple testing

Multiple test procedures are usually compared on various aspects of error control and power. Power is measured as some function of the number of false hypotheses correctly identified as false. However, given equal numbers of rejected false hypotheses, the pattern of rejections, i.e. the particular set of false hypotheses identified, may be crucial in interpreting the results for potential application.In an important area of application, comparisons among a set of treatments based on random samples from populations, two different approaches, cluster analysis and model selection, deal implicitly with such patterns, while traditional multiple testing procedures generally focus on the outcomes of subset and pairwise equality hypothesis tests, without considering the overall pattern of results in comparing methods. An important feature involving the pattern of rejections is their relevance for dividing the treatments into distinct subsets based on some parameter of interest, for example their means. This paper introduces some new measures relating to the potential of methods for achieving such divisions. Following Hartley (1955), sets of treatments with equal parameter values will be called clusters. Because it is necessary to distinguish between clusters in the populations and clustering in sample outcomes, the population clusters will be referred to as P -clusters; any related concepts defined in terms of the sample outcome will be referred to with the prefix outcome. Outcomes of multiple comparison procedures will be studied in terms of their probabilities of leading to separation of treatments into outcome clusters, with various measures relating to the number of such outcome clusters and the proportion of true vs. false outcome clusters. The definitions of true and false outcome clusters and related concepts, and the approach taken here, is in the tradition of hypothesis testing with attention to overall error control and power, but with added consideration of cluster separation potential.The pattern approach will be illustrated by comparing two methods with apparent FDR control but with different ways of ordering outcomes for potential significance: The original Benjamini-Hochberg (1995) procedure (BH), and the Newman-Keuls (Newman, 1939; Keuls, 1952) procedure (NK).     

Feasibility of using a fully immersive virtual reality system for kinematic data collection

Commercially-available Virtual Reality (VR) systems have the potential to be effective tools for simultaneous visual manipulation and kinematic data collection. Previously, these systems have been integrated with research-grade motion capture systems to provide both functionalities; however, they are yet to be used as stand-alone systems for kinematic data collection. The present study aimed to validate the HTC VIVE VR system for kinematic data collection by evaluating the accuracy of its position and orientation signals. The VIVE controller and tracker were each compared to a Polhemus Liberty magnetic tracking system sensor for angular and translational measurement error and signal drift. A sensor from each system was mounted to opposite ends of a rigid segment which was driven through fifty rotations and fifty translations. Mean angular errors for both the VIVE tracker and controller were below 0.4°. Mean translational error for both sensors was below 3 mm. Drift in the Liberty signal components was consistently lower than drift in VIVE components. However, all mean rotational drift measures were below 0.1° and all mean translational measures were below 0.35 mm. These data indicate that the HTC VIVE system has the potential to be a valid and reliable means of kinematic data collection. However, further investigation is necessary to determine the VIVE’s suitability for capturing extremely minute or high-volume movements.     

Reliability of assessing postural control during seated balancing using a physical human-robot interaction

This study evaluated the within- and between-visit reliability of a seated balance test for quantifying trunk motor control using input–output data. Thirty healthy subjects performed a seated balance test under three conditions: eyes open (EO), eyes closed (EC), and eyes closed with vibration to the lumbar muscles (VIB). Each subject performed three trials of each condition on three different visits. The seated balance test utilized a torque-controlled robotic seat, which together with a sitting subject resulted in a physical human-robot interaction (pHRI) (two degrees-of-freedom with upper and lower body rotations). Subjects balanced the pHRI by controlling trunk rotation in response to pseudorandom torque perturbations applied to the seat in the coronal plane. Performance error was expressed as the root mean square (RMSE) of deviations from the upright position in the time domain and as the mean bandpass signal energy (E_mb) in the frequency domain. Intra-class correlation coefficients (ICC) quantified the between-visit reliability of both RMSE and E_mb. The empirical transfer function estimates (ETFE) from the perturbation input to each of the two rotational outputs were calculated. Coefficients of multiple correlation (CMC) quantified the within- and between-visit reliability of the averaged ETFE. ICCs of RMSE and E_mb for all conditions were ≥0.84. The mean within- and between-visit CMCs were all ≥0.96 for the lower body rotation and ≥0.89 for the upper body rotation. Therefore, our seated balance test consisting of pHRI to assess coronal plane trunk motor control is reliable.     

Normative cervical spine kinematics of a circumduction task

Neck pain is a prevalent condition and clinical examination techniques are limited and unable to assess out-of-plane motion. Recent works investigating cervical kinematics during neck circumduction (NC), a dynamic 3D task, has shown the ability to discern those with and without neck pain. The purposes of this study were to establish 1) confidence and prediction intervals of head-to-torso kinematics during NC in a healthy cohort, 2) a baseline summative metric to quantify the duration and magnitude of deviations outside the prediction interval, and 3) the reliability of NC. Thirty-nine participants (25.6 ± 6.3 years, 19F/20M) without neck pain completed left and right NC. A two-way smoothing spline analysis of variance was utilized to determine the mean-fitted values and 90% confidence and prediction intervals for NC. A standardized effect size was calculated and aggregated across all axes (Delta RMSD aggregate), as a summative metric of motion quality. Confidence and prediction intervals were comparable for left and right NC and demonstrated excellent reliability. The average sum of the Delta RMSD aggregate was 2.76 ± 0.55 for left NC and 2.74 ± 0.63 for right NC. The results of this study demonstrate the feasibility of utilizing normative intervals of a NC task to assess head-to-torso kinematics.     

Four-dimensional imaging with virtual reality to quantitatively explore jigsaw puzzle-like morphogenesis of Arabidopsis cotyledon pavement cells

In most dicotyledonous plants, leaf pavement cells exhibit complex jigsaw puzzle-like cell morphogenesis during leaf expansion. Although detailed molecular biological information and mathematical modeling of this jigsaw puzzle-like cell morphogenesis are now available, a full understanding of this process remains elusive. Recent reports have highlighted the importance of three-dimensional (3D) structures (i.e., anticlinal and periclinal cell wall) in understanding the mechanical models that describe this morphogenetic process. We believe that it is important to acquire 3D shapes of pavement cells over time, i.e., acquire and analyze four-dimensional (4D) information when studying the relationship between mechanical modeling and simulations and the actual cell shape. In this report, we have developed a framework to capture and analyze 4D morphological information of Arabidopsis thaliana cotyledon pavement cells by using both direct water immersion observations and computational image analyses, including segmentation, surface modeling, virtual reality and morphometry. The 4D cell models allowed us to perform time-lapse 3D morphometrical analysis, providing detailed quantitative information about changes in cell growth rate and shape, with cellular complexity observed to increase during cell growth. The framework should enable analysis of various phenotypes (e.g., mutants) in greater detail, especially in the 3D deformation of the cotyledon surface, and evaluation of theoretical models that describe pavement cell morphogenesis using computational simulations. Additionally, our accurate and high-throughput acquisition of growing cell structures should be suitable for use in generating in silico model cell structures.     

某型歼击机综合抗荷措施的防护效果研究

目的:研究以KH-x扩大囊覆盖面积抗荷服、无胸部代偿的抗荷加压呼吸及PHP动作组成的某型歼击机综合抗荷措施的抗荷效果;探讨采用该措施进行防护时伴有的疲劳、疼痛等问题.方法:5名被试者在载人离心机上进行了5组 Gz暴露试验,分别为:①基础 Gz耐力试验;②KH-x抗荷服配KT-x抗荷调压器试验;③抗荷加压呼吸试验;④6.5 G持续45 s试验;⑤9.0 G持续15 s试验.以第2组及第1组试验的 Gz耐力差值作为KH-x抗荷服配KT-x抗荷调压器的抗荷性能;以第3组及第2组试验的 Gz耐力差值作为PBG的抗荷性能.在每次试验结束后用主观量表记录被试者疲劳及疼痛的程度.结果:试验中没有发生1例G-LOC(Ginduced lose of consciousness).KH-x抗荷服配KT-x抗荷调压器的抗荷效果为2.3 G;PBG的抗荷效果为1.7 G;被试者均完成了6.5G持续45 s及9.0 G持续15 s试验.试验中被试者的颈、腰、臂及手部在 Gz暴露时均出现过疼痛,其中腰部疼痛出现的次数最多.结论:某型歼击机综合抗荷措施可以满足现代高性能战斗机9.0 G的防护需要;该措施还应在高G导致的疼痛及颈部损伤的防护方面加以改进.     

The potential fertility estimation capacity of the hypoosmotic swelling test, the thermal stress test and a modified cervical mucus penetration test in the bovine

In this study, hypoosmotic swelling (HOS), thermal stress (TS) and modified cervical mucus penetration (mCMP) tests have been used with routine tests for the assessment of semen quality. This is the first study in which the comparison of potential fertility estimation of fore-mention three tests was performed. Bull semen samples were divided into two fertility groups (high: n=3, low: n=3), according to their post-insemination NRR (non-return rate). Prior to the tests, post-thawed spermatological characteristics were assessed after which HOS, TS and mCMP tests were carried out. In the HOS test, the ratio of swollen cells, in the TS test the motility, and in the mCMP test the number of spermatozoa penetrating the cervical mucus, were examined. The relationship between the tests and fertility was also evaluated. HOS test was carried out according to different incubation times and temperatures (37 degrees C 60 min/41 degrees C 15 min/41 degrees C 30 min/46 degrees C 15 min/46 degrees C 30 min). For TS test, samples were subjected to various temperatures for different periods (no incubation (37 degrees C)/41 degrees C 15 min/41 degrees C 30 min/46 degrees C 15 min/46 degrees C 30 min). The mCMP test were subjected to various temperatures for the same period (37 degrees C 15 min/41 degrees C 15 min). In this study, post-thawed motility was found to be similar in high and low fertility groups. However, it has been determined that acrosomal (p<0.01) and other morphological defects (p<0.05) were low in the high fertility group. When HOS test was carried out at 37 degrees C, no difference was observed between the bulls with high and low fertility, but at 41 and 46 degrees C, results of high fertility group were significantly higher than those of low fertility group (p<0.01). Similarly in TS test, the progressive motility rates of high fertility bulls was higher after thermal practices at 41 and 46 degrees C (p<0.01). In mCMP test, at 37 degrees C, the number of cells that had penetrated was similar. However, significant differences were observed in the incubation at 41 degrees C (p<0.01). It has been concluded that for the estimation of potential fertility of bulls, HOS, TS and mCMP tests, in combination with routine spermatological tests can be used and the use of further penetration distance range (PDR2) in mCMP test and higher temperatures such as 41 degrees C instead of 37 degrees C, during the incubations in the afore-mentioned performance tests, is more determinative.     

糠秕马拉色菌药敏试验新方法的探讨

目的 建立一种新的糠秕马拉色菌药敏试验方法.方法 在ATBF2半固体培养基中添加不同种类和含量的脂质,用ATB Fungus 3药敏板条对ATCC14521和临床分离的糠秕马拉色菌进行了MIC测试.结果 孵育时间为72 h时对照孔中糠秕马拉色菌生长充分,吐温40浓度为1％时糠秕马拉色菌生长充分,且对药敏结果的影响最小.脂质的种类和含量对实验结果有影响.结论 用改良ATB Fungus 3药敏试验方法对糠秕马拉色菌进行抗真菌药敏试验,方法操作简便、结果易观察、试验结果重复性好.临床分离菌株与糠秕马拉色菌ATCC14521在ATB Fungus 3对照孔中的生长状况相同,结果易于判断.     

A new apparatus to measure the rate of fall of seeds

1. Seed dispersal is widely recognized to be of crucial importance in the ecology of plant communities, yet characterization of dispersal capacity rarely goes beyond two categories: 'good' and 'poor' dispersers, defined on the basis of dispersule morphology.
2. We describe a new apparatus which determines the rate of fall of seeds in air by detecting their passage through two fans of laser light.
3. This apparatus is able to measure rate of fall in smaller seeds than previously published methods and reveals that there is no justification for the arbitrary division of species into two wind dispersal categories.