Effects of a Cooperative Learning Program on the Elaborations of Students Working in Dyads

In this study, the effects of a school improvement program on cooperative learning (CL) with respect to the elaborations of 6th-grade students working in mixed-ability and mixed-sex dyads on 2 cooperative tasks were examined. A posttest-only design with a control group was used to investigate the provision and receipt of elaborations within the dyads and the performance of the dyads working on cooperative mathematics and language tasks. Treatment dyads were found to exchange significantly more high-level elaborations during the language task than the control dyads. The treatment dyads also tended to produce higher performance scores on the 2 tasks.     

Fibre Optic Reflectance Spectroscopy as a non-invasive tool for investigating plastics degradation in contemporary art collections: A methodological study on an expanded polystyrene artwork

Fibre Optics Reflectance Spectroscopy (FORS) is a well-established technique, widely used in the conservation field for in situ investigations and non-invasive diagnostics on traditional artworks. Nevertheless, there is little knowledge on the use of this technique for investigating modern artists materials used in contemporary artworks. The present study, carried out within the wider framework of the EC funded Project “POPART” (Preservation of Plastic ARTefacts in museum collections”), was aimed at investigating the possibility of extending the applications of FORS to synthetic polymers, and proposing this technique as new non-invasive analytical tool for diagnostics on plastic artworks in museum collections. Thus, a real case was selected from the permanent collection of the Conteporary Art Centre “Luigi Pecci” (Prato, Italy). The artwork, created in 1990 by the artist Stefano Arienti, was entirely constituted of expanded polystyrene (EPS) and it showed diffused signs of degradation. The need of singling out the main causes of deterioration in order to prevent further damages was evident. An in situ FORS measurements campaign was performed with the aim of gaining in-depth information about its conservation state and identifying the main agents responsible for the observed degradation. Thanks to the non-invasivity of the technique an extensive spectroscopic characterisation of different areas of the EPS surface could be performed and the spectral data were exploited to build a map of the degraded areas of the artwork. Data acquired in field were compared with those obtained from laboratory test performed on artificially aged EPS samples. These results helped in ascertaining the detrimental actions of the light sources used to back illuminate the artwork. In particular, in this case FORS proved to be effective in detecting EPS alterations before the chromatic effects became visually evident. These results suggested that FORS may be considered as a good candidate to be used for non-invasive investigations also on some modern materials and contemporary artworks. The research was completed with an interview to the artist Stefano Arienti, whose point of view was constructively integrated with the scientific results obtained. This emphasized the importance of an interdisciplinary approach to the solution of conservative problem in the field of contemporary art.     

Association between knee-to-hip flexion ratio during single-leg vertical landings,and strength and range of motion in professional soccer players

Abstract

The aim of this study was to test the correlation between knee-to-hip flexion ratio during a single leg landing task and hip and knee strength, and ankle range of motion. Twenty-four male participants from a professional soccer team performed a continuous single leg jump-landing test during 10s, while lower limb kinematics data were collected using a motion analysis system. After biomechanical testing, maximal isometric hip (abduction, extension, external rotation), knee extension and flexion strength were measured. Maximum ankle dorsiflexion range of motion was assessed statically using the weight bearing lunge test. Pearson correlation coefficients were calculated to determine the associations between the predictor variables (knee and hip strength, and ankle ROM) and the main outcome measure (knee-to-hip flexion ratio). Correlation between knee-to-hip flexion ratio and hip abductors strength was significant (r = ?0.47; p = 0.019). No other significant correlations were observed among the variables (p > 0.05). These results demonstrated that a lower hip abductors strength in male soccer players was correlated with a high knee-to-hip flexion ratio during landing from a single leg jump, potentially increasing knee overload by decreasing energy absorption at the hip. The results provide a novel proposal for the functioning of hip muscles to control knee overload.     

Counselling implications of the opening of the Berlin Wall

Articles

Counselling implications of the opening of the Berlin Wall     

Simultaneous Assembly of Multiple Test Forms

An algorithm for the assembly of multiple test forms is proposed in which the multiple-form problem is reduced to a series of computationally less intensive two-form problems. At each step, one form is assembled to its true specifications; the other form is a dummy assembled only to maintain a balance between the quality of the current form and the remaining forms. It is shown how the method can be implemented using the technique of O-1 linear programming. Two empirical examples using a former item pool from the LSAT are given—one in which a set of parallel forms is assembled and another in which the targets for the information functions of the forms are shifted systematically.     

Alternative assessment of knee joint muscle balance of soccer players through total work-based hamstring: quadriceps ratios

Isokinetic hamstring-to-quadriceps (H:Q) ratios are frequently used to assess knee muscle strength imbalances and risk of injuries/re-injuries. The use of peak torque (PT) or total work (TW) to estimate joint stability may lead to different results because of the differences between these two neuromuscular variables. Thus, the current study aimed to compare the conventional and functional H:Q ratios calculated by PT and TW. Ninety-three male professional soccer players from Brazilian first division teams performed isokinetic concentric and eccentric contractions of the quadriceps and the hamstrings at 60°/s. Muscle strength balance was calculated using the conventional torque ratio (CTR) and conventional work ratio (CWR), functional torque ratio (FTR) and functional work ratio (FWR) were highly and moderately correlated between them (r?=?0.83 and r?=?0.73, respectively). The Wilcoxon statistical test revealed significant differences between CTR and CWR, as well as FTR and FWR (p?T-test demonstrated significant differences in mean CTR–CWR and FTR–FWR, whereas Bland–Altman plots showed non-consistent bias. In addition, the chi-square test demonstrated significant differences between players below the conventional reference values and functional reference values (p?相似文献   

Effect of Dehydration on Passing Decision Making in Soccer Athletes

It seems that dehydration may impair decision-making performance in athletes. Purpose: This study aimed to investigate the influence of dehydration on passing decision-making performance in soccer players. Method: Participants were 40 male soccer players (M_age = 22.3 ± 2.3 years) who agreed to participate in the study and were randomly assigned to the following conditions: control (CON), dehydration (DEH), and euhydration (EUH). The players played in 2 games of 90 min in duration (2 45-min halves) followed by 2 15-min halves (overtime) with and without proper hydration. The Game Performance Assessment Instrument (GPAI) was considered for the analysis of passing decision making. Results: The GPAI analysis indicated effective reduction in the decision-making index in the DEH condition compared with the EUH and CON conditions, F(2, 38) = 31.4, p < .05, ES = 0.8. Conclusions: In conclusion, dehydration may be considered a mediating factor in the passing decision-making performance of male soccer athletes.     

Dealing with metadata quality: The legacy of digital library efforts

In this work, we elaborate on the meaning of metadata quality by surveying efforts and experiences matured in the digital library domain. In particular, an overview of the frameworks developed to characterize such a multi-faceted concept is presented. Moreover, the most common quality-related problems affecting metadata both during the creation and the aggregation phase are discussed together with the approaches, technologies and tools developed to mitigate them. This survey on digital library developments is expected to contribute to the ongoing discussion on data and metadata quality occurring in the emerging yet more general framework of data infrastructures.     

A Comparison of Item-Selection Methods for Adaptive Tests with Content Constraints

In test assembly, a fundamental difference exists between algorithms that select a test sequentially or simultaneously. Sequential assembly allows us to optimize an objective function at the examinee's ability estimate, such as the test information function in computerized adaptive testing. But it leads to the non-trivial problem of how to realize a set of content constraints on the test—a problem more naturally solved by a simultaneous item-selection method. Three main item-selection methods in adaptive testing offer solutions to this dilemma. The spiraling method moves item selection across categories of items in the pool proportionally to the numbers needed from them. Item selection by the weighted-deviations method (WDM) and the shadow test approach (STA) is based on projections of the future consequences of selecting an item. These two methods differ in that the former calculates a projection of a weighted sum of the attributes of the eventual test and the latter a projection of the test itself. The pros and cons of these methods are analyzed. An empirical comparison between the WDM and STA was conducted for an adaptive version of the Law School Admission Test (LSAT), which showed equally good item-exposure rates but violations of some of the constraints and larger bias and inaccuracy of the ability estimator for the WDM.