The role of memory aids in two instructional paradigms: Learning and utilization of logical rules

One hundred and thirty-two 10th graders performed either a conjunetive or biconditional rule task in one of six conditions defined by a 2 (tasks: attribute-identification versus rule-learning) by 3 (memory aids: 0 versus 3 versus 6) factorial design. Learners' attribute-identification was facilitated when six memory aids were made available, especially given the biconditional rule, but not when three aids were available. This effect was attributed to the facilitative role of six memory aids in the process of eliminating irrelevant dimensions. The acquisition of the biconditional rule was a linear function of the number of memory aids; but that of the conjunctive rule was not differentially affected by the memory aids. This interaction was attributed to the facilitative role of memory aids in the formation of a relatively complex one, not in the identification of a familiar, easy one.     

Effects of the model's skill level on observational motor learning.

Observation of a model prior to physical practice often facilitates the acquisition of motor skills. The majority of research studies on observational motor learning has used a skilled model for the demonstration. Recent research, however, suggests that observing an unskilled (learning) model may also be effective. The experiment reported here compared motor skill acquisition following observation of a learning model or a skilled model to the performance of subjects who lacked the benefit of observation. The task was to play a computer tracking game. Subjects were tested in pairs. Observers watched either a skilled or a learning model perform 3 trials. The observers then practiced the game for 3 trials. Observation of another 12 trials was followed by 12 more practice trials. Substantial observational learning was found, as both groups of observers performed better than the learning models after both the 3 initial trials of observation and after 12 more observation trials. However, there were no differences due to observing the skilled or the learning model. These findings are discussed in relation to theoretical issues of observational learning.     

Rapid and cost-effective fabrication of selectively permeable calcium-alginate microfluidic device using ��modified�� embedded template method

In this paper, we have presented a non-lithographic embedded template method for rapid and cost-effective fabrication of a selectively permeable calcium-alginate (Ca-alginate) based microfluidic device with long serpentine delay channel. To demonstrate the versatility of the presented method, we have demonstrated two different strategies to fabricate serpentine long delay channels without using any sophisticated microfabrication techniques, in formal lab atmosphere. The procedure presented here, also, enables the preparation of a multilayered microfluidic device with channels of varying dimensions, in a single device without using any sophisticated micromachining instrumentation. In addition, we have also qualitatively studied the diffusion of small and large molecules from a Ca-alginate based microfluidic device and proposed a method to effectively control the out-flow of macro biomolecules from the crosslinked Ca-alginate matrix to create a selectively permeable matrix required for various biological and biomimetic applications, as mentioned in the Introduction section of this work.     

Rapid detection of live methicillin-resistant Staphylococcus aureus by using an integrated microfluidic system capable of ethidium monoazide pre-treatment and molecular diagnosis

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium resistant to all existing penicillin and lactam-based antimicrobial drugs and, therefore, has become one of the most prevalent antibiotic-resistant pathogens found in hospitals. The multi-drug resistant characteristics of MRSA make it challenging to clinically treat infected patients. Therefore, early diagnosis of MRSA has become a public-health priority worldwide. Conventionally, cell-culture based methodology and microscopic identification are commonly used for MRSA detection. However, they are relatively time-consuming and labor-intensive. Recently, molecular diagnosis based on nucleic acid amplification techniques, such as polymerase chain reaction (PCR), has been widely investigated for the rapid detection of MRSA. However, genomic DNA of both live and dead pathogens can be distinguished by conventional PCR. These results thus could not provide sufficient confirmation of an active infection for clinicians. In this study, live MRSA was rapidly detected by using a new integrated microfluidic system. The microfluidic system has been demonstrated to have 100% specificity to detect live MRSA with S. aureus and other pathogens commonly found in hospitals. The experimental results showed that the limit of detection for live MRSA from biosamples was approximately 10² CFU/μl. In addition, the entire diagnostic protocol, from sample pre-treatment to fluorescence observation, can be automatically completed within 2.5 h. Consequently, this microfluidic system may be a powerful tool for the rapid molecular diagnosis of live MRSA.     

Changes in biomechanics and muscle activation in injured ballet dancers during a jump-land task with turnout (Sissonne Fermée)

Large impact loading with abnormal muscle activity and motion patterns may contribute to lower extremity injuries in ballet dancers. Yet, few studies investigated the influence of injury on the ballet movement. The purpose of this study was to find the neuromuscular and biomechanical characteristics in dancers with and without ankle injury during a jump-landing Sissonne Fermée task. Twenty-two ballet dancers were recruited and divided into the injured group (n = 11) and the uninjured group (n = 11). They performed a ballet movement called "Sissonne Fermée" with reflective markers and electrodes attached to their lower extremities. Ground reaction force, joint kinematics, and muscle activity were measured. The injured dancers had greater peak ankle eversion but smaller hindfoot-to-tibial eversion angles. Also, the injured dancers had greater activity of the hamstring of the dominant leg and tibialis anterior of the non-dominant leg during the pre-landing phase. The injured dancers had greater tibialis anterior activity of the dominant leg but less muscle activity in the medial gastrocnemius of the non-dominant leg during the post-landing phase. The injured dancers had a greater co-contraction index in the non-dominant ankle and a lower loading rate. The higher co-contraction indices showed that the injured dancers required more muscle effort to control ankle stability. Furthermore, the injured dancers used a "load avoidance strategy" to protect themselves from re-injury. Neuromuscular control training of the ankle joint for ballet dancers to prevent injury is necessary.     

National Board Certified Physical Educators: perceived changes related to the certification process

In this study, we examined National Board certified physical education teachers' (NBCPETs) perceptions of change as a result of certification. Randomly selected NBCPETs (65; women = 53, men = 12) were interviewed. Analysis was done through the lens of Lawson's (1989) Model of the interactive factors Influencing workplace conditions for the Physical Education Teacher Several themes connected to teachers' views of themselves as NBCPETs surfaced. In particular more teaching reflection and a greater focus on student learning and assessment, including an increased emphasis on individualizing teaching were described. An elevation in their perceived status and credibility and expanded opportunities within the educational community also emerged. Alternatively, several NBCPETs explained that the certification process had little or no effect on their teaching     

User-satisfaction based bandwidth allocation for transmission of multiple sources of human perceptual data

In recent years, more and more point-to-point communication systems involve simultaneous transmission of multiple sources of human perceptual data over a single communication medium. For example, in a teleoperation system or a telerobotic system, streams of video, audio, and haptic data need to be sent from a field place to a remote human operator. Each type of data demands a certain range of transmission rate. This creates conflicts among these data when the available bandwidth is limited.In this paper we study the bandwidth allocation for multiple sources of human perceptual data transmitted over a rate-limited communication channel. We aim to maximize the overall user satisfaction in the data transmission, and formulate an optimization problem for the bandwidth allocation. Using either the logarithmic or exponential form of human perceptual satisfaction function, we are able to derive closed-form solutions for the optimization problem. We show that the optimal bandwidth allocation for each type of data is piecewise linear with respect to the total available bandwidth.     

Assessment of planarity of the golf swing based on the functional swing plane of the clubhead and motion planes of the body points

The purposes of this study were (1) to determine the functional swing plane (FSP) of the clubhead and the motion planes (MPs) of the shoulder/arm points and (2) to assess planarity of the golf swing based on the FSP and the MPs. The swing motions of 14 male skilled golfers (mean handicap = -0.5 +/- 2.0) using three different clubs (driver, 5-iron, and pitching wedge) were captured by an optical motion capture system (250Hz). The FSP and MPs along with their slope/relative inclination and direction/direction of inclination were obtained using a new trajectory-plane fitting method. The slope and direction of the FSP revealed a significant club effect (p < 0.001). The relative inclination and direction of inclination of the MP showed significant point (p < 0.001) and club (p < 0.001) effects and interaction (p < 0.001). Maximum deviations of the points from the FSP revealed a significant point effect (p < 0.001) and point-club interaction (p < 0.001). It was concluded that skilled golfers exhibited well-defined and consistent FSP and MPs, and the shoulder/arm points moved on vastly different MPs and exhibited large deviations from the FSP. Skilled golfers in general exhibited semi-planar downswings with two distinct phases: a transition phase and a planar execution phase.