Validity of an ultra-wideband local positioning system to assess specific movements in handball

The aim of this study was to examine the concurrent validity of the Kinexon local positioning system (LPS) in comparison with the Vicon motion capture system used as the reference. Five recreationally active men performed ten repetitions of linear sprints, medio-lateral side-to-side and handball-specific movements both in the centre and on the side of an indoor field. Validity was assessed for peak speed, peak acceleration and peak deceleration using standardised biases, Pearson coefficient of correlation (r), and standardised typical error of the estimate. With the exception of peak decelerations during specific movements in the centre and peak acceleration and deceleration during linear sprints on the side of the field, the standardised typical error of the estimate (TEE) values were all small to moderate (0.06–0.48), standardised bias ranged between 0.01 and 2.85 and Pearson coefficient values were all > 0.90 for all variables in all conditions. Peak acceleration and deceleration during linear sprints on the side of the field showed the largest TEEs and the greatest differences between the two systems. The ultra-wideband based (UWB) local positioning system had acceptable validity compared with Vicon to assess players’ movements in handball with the exception of high accelerations and decelerations during linear sprints on the side of the field.     

Rethinking historical controls

Inference from traditional historical controls, i.e. comparing a new treatment in a current series of patients with an old treatment in a previous series of patients, may be subject to a strong selection bias. To avoid this bias, Baker and Lindeman (1994) proposed the paired availability design. By applying this methodology to estimate the effect of epidural analgesia on the probability of Cesarean section, we made two important contributions with the current study. First, we generalized the methodology to include different types of availability and multiple time periods. Second, we investigated how well the paired availability design reduced selection bias by comparing results to those from a meta-analysis of randomized trials and a multivariate analysis of concurrent controls. The confidence interval from the paired availability approach differed considerably from that of the multivariate analysis of concurrent controls but was similar to that from the meta-analysis of randomized trials. Because we believe the multivariate analysis of concurrent controls omitted an important predictor and the meta-analysis of randomized trials was the gold standard for inference, we concluded that the paired availability design did, in fact, reduce selection bias.     

培美曲塞+顺铂方案诱导化疗联合同期放化疗对局部晚期非小细胞肺癌的近期疗效及安全性观察

目的:探究培美曲塞+顺铂方案诱导化疗联合同期放化疗对局部晚期非小细胞肺癌的近期疗效及安全性。方法:收集我院肿瘤科2009年7月到2011年7月住院治疗的局部晚期非鳞癌非小细胞癌患者54例,按照随机数字表法分为研究组和对照组,每组27例,研究组给予培美曲塞+顺铂方案诱导化疗联合同期放化疗,对照组仅给予培美曲塞+顺铂方案化疗联合同期放疗,治疗2个周期,随访2年,对比两组患者的近期疗效及安全性。结果:研究组的近期有效率和控制率分别为55.56%、77.78%,高于对照组的50.33%和59.26%,有效率和控制率差异具有统计学意义(P0.05)。随访2年,研究组的中位生存期为12.77个月,1年生存率为48.15%,高于对照组中位生存期11.28个月,1年生存率40.74%,但差异无统计学意义(P0.05),研究组2年生存率为43.46%,高于对照组的25.38%,差异具有统计学意义(P0.05);研究组白细胞减少以及脱发发生率分别为37.0%、25.9%,低于对照组的81.5%和55.5%,差异具有统计学意义(均P0.05);研究组中血小板减少、血红蛋白减少、呕吐、肝功能损害、肾功能损耗、皮疹等发生率分别为40.7%、22.2%、59.2%、11.1%、7.4%、14.8%,高于对照组中各不良反应发生率分别为33.3%、18.5%、55.5%、14.8%、11.1%、7.4%,但两组间差异无统计学意义(P0.05)。结论:培美曲塞+顺铂方案诱导化疗联合同期放化疗对局部晚期非小细胞肺癌治疗效果明显,且不良反应少,可作为临床上晚期非小细胞肺癌化疗一线药物。     

Biodegradation of diethyl phthalate by an organic-solvent-tolerant Bacillus subtilis strain 3C3 and effect of phthalate ester coexistence

The contamination and distribution of phthalate esters - synthetic compounds widely used in plastic product production, including food and medical packaging - has raised safety concerns due to their endocrine-disrupting activity and mandated to be treated. Bacillus subtilis strain 3C3, isolated as an organic-solvent-tolerant bacterium, was capable of utilizing diethyl phthalate as a sole carbon source. Biodegradation of diethyl phthalate occurred constitutively without lag period, and its kinetics followed a first-order model. The biodegradability was significantly enhanced with the supplementation of yeast extract as a co-metabolic substrate. In the presence of Tween-80 as a solubilizing agent, cells rapidly degrade a range of short-chain phthalate esters at high concentrations (up to 1000 mg l⁻¹ for diethyl phthalate). The biodegradation of short-chain phthalates in the binary, ternary and quaternary substrate system revealed that the coexistence of other short-chain phthalates had no significant influence on the biodegradation of diethyl phthalate, and vice versa. These results substantiated that B. subtilis strain 3C3 has potential application as a bioaugmented bacterial culture for bioremediation of phthalates.     

The genetics of selfing with concurrent backcrossing in breeding hybrid sugar beet (Beta vulgaris altissima L.)

 Sugar beet hybrids are produced by crossing a cytoplasmic male-sterile (CMS) line with a pollinator. New CMS lines are produced by crossing a fertile plant to an existing CMS line. The fertile plant is also selfed. In the following generation, one of the selfed, fertile progeny is paired and isolated with one of the crossed, CMS progeny, to give a second generation of selfing and crossing. Over a series of such crosses and selfs, a new fertile inbred line and its corresponding, near-isogenic CMS partner are produced. Selection among lines takes place at one or more stages of the backcrossing programme. A method is presented here for calculating the genetic variances and covariances within and between lines and generations based on a derivation of additive genetic relationships modified from an approach widely employed in animal breeding. The genetic variances and covariances are used to predict response to selection from varying strategies, from which optimum schemes can be determined. Results suggest that selection should generally take place after three generations of backcrossing when the fertile plant used to initiate the backcrossing process is not inbred, but can take place after generation two when the fertile plant is inbred. Doubled haploid production is unlikely to provide an extra advantage that would be worthwhile in such a system. The method developed here can be used to explore a wide range of more complex breeding systems. Received: 27 July 1998 / Accepted: 19 October 1998     

Comparing the generalized matching law and contingency discriminability model as accounts of concurrent schedule performance using residual meta-analysis

To compare the generalized matching law (Baum, W.M., 1974b. On two types of deviation from the matching law: bias and undermatching. J. Exp. Anal. Behav. 22, 231-242) and contingency discriminability model (Davison, M., Jenkins, P.E., 1985. Stimulus discriminability, contingency discriminability, and schedule performance. Anim. Learn. Behav. 13, 77-84) as accounts of concurrent schedule performance, we conducted a residual meta-analysis of response- and time-allocation data from 20 studies (n's=886 and 774, respectively). Both models were fitted to the individual-subject data from each study, and residuals were obtained. Polynomial regressions were then performed on the pooled residuals to determine whether systematic trends were present as a function of predicted values. For the contingency discriminability model, the cubic coefficients were positive and statistically significant for both response- and time-allocation data. By contrast, no statistically significant systematic trend was obtained in the residuals for the generalized matching law. These results suggest that the relationship between log response allocation and log reinforcer allocation does not deviate significantly from linearity over an approximate range of +1.25 to -1.25 log units, consistent with the generalized matching law. Although qualitative criteria are also important in comparing models of behavioral phenomena, residual meta-analysis provides a powerful quantitative methodology for model selection and should prove useful in future research.     

Effect of contingent auditory stimuli on concurrent schedule performance: an alternative punisher to electric shock

This study explored whether load auditory stimuli could be used as functional punishing stimuli in place of electric shock. Three experiments examined the effect of a loud auditory stimulus on rats’ responding maintained by a concurrent reinforcement schedule. In Experiment 1, overall response rate decreased when a concurrent 1.5 s tone presentation schedule was superimposed on the concurrent variable interval (VI) 180-s, VI 180-s reinforcement schedule. On the contrary, response rate increased when a click presentation schedule was added. In Experiment 2, the extent of the response suppression with a 1.5 s tone presentation varied as a function of the frequency of the reinforcement schedule maintaining responses; the leaner the schedule employed, the greater the response suppression. In Experiment 3, response suppression was observed to be inversely related to the duration of the tone; response facilitation was observed when a 3.0-s tone was used. In Experiments 1 and 2, a preference shift towards the alternative with richer reinforcement was observed when the tone schedule was added. In contrast, the preference shifted towards the leaner alternative when the click or longer duration stimulus was used. These results imply that both the type and duration of a loud auditory stimulus, as well as the reinforcement schedule maintaining responses, have a critical role in determining the effect of the stimuli on responding. They also suggest that a loud auditory stimulus can be used as a positive punisher in a choice situation for rats, when the duration of the tone is brief, and the reinforcement schedule maintaining responses is lean.     

Nicotine and the behavioral mechanisms of intertemporal choice

Nicotine has been found to produce dose-dependent increases in impulsive choice (preference for smaller, sooner reinforcers relative to larger, later reinforcers) in rats. Such increases could be produced by either of two behavioral mechanisms: (1) an increase in delay discounting (i.e., exacerbating the impact of differences in reinforcer delays) which would increase the value of a sooner reinforcer relative to a later one, or (2) a decrease in magnitude sensitivity (i.e., diminishing the impact of differences in reinforcer magnitudes) which would increase the value of a smaller reinforcer relative to a larger one. To isolate which of these two behavioral mechanisms was likely responsible for nicotine's effect on impulsive choice, we manipulated reinforcer delay and magnitude using a concurrent, variable interval (VI 30 s, VI 30 s) schedule of reinforcement with 2 groups of Long-Evans rats (n = 6 per group). For one group, choices were made between a 1-s delay and a 9-s delay to 2 food pellets. For a second group, choices were made between 1 pellet and 3 pellets. Nicotine (vehicle, 0.03, 0.1, 0.3, 0.56 and 0.74 mg/kg) produced dose-dependent decreases in preference for large versus small magnitude reinforcers and had no consistent effect on preference for short versus long delays. This suggests that nicotine decreases sensitivity to reinforcer magnitude.