Electromyographic analysis of thigh muscles during track cycling on a velodrome

We aimed to investigate neuromuscular activation of thigh muscles during track cycling at various speeds. Eight male competitive cyclists volunteered to participate in this study. Surface electromyography of the vastus lateralis, biceps femoris and adductor magnus muscles of the bilateral legs was recorded during track cycling on velodromes with a 250-m track. The participants were instructed to maintain three different lap times: 20, 18 and 16 s. The average rectified value (ARV) was calculated from the sampled surface electromyography. Significantly higher ARVs were observed in the right compared to left leg for the biceps femoris muscle during both straight and curved sections at 18- and 16-s lap times (P < 0.05). In the biceps femoris muscle, significant changes in ARVs during the recovery phase with an increase in speed were seen in the right leg only (P < 0.05). There were no significant differences in ARVs between the straight and curved sections for all three muscles (P > 0.05). From our findings, it was suggested that during track cycling on a velodrome the laterality of the biceps femoris muscle activity is a key strategy to regulate the speed, and fixed neuromuscular strategies are adopted between straight and curved sections for thigh muscles.     

Spousal Presence Modulates Salivary α-Amylase Responses to Infant Cry in Mothers With High Attachment Insecurity

SYNOPSIS

Objective: Infant cry, a major stressor for caregivers, is one of the leading triggers of child abuse. The present study examined the effects of spousal support, spousal presence, and the possible moderating effect of attachment insecurity on individuals’ subjective and physiological responses to infant cry. Design: Thirty-one healthy mothers (M age = 36 years) and their spouses participated in an infant crying paradigm, where mothers were tasked to listen to infant cries under three conditions: (1) alone, (2) in the same room as partner, without physical contact, and (3) in the same room as partner, with hand-holding. Attachment was determined using the Experiences in Close Relationship Questionnaire, and physiological response was ascertained from concentration of salivary α-amylase (sAA). After each cry sound, sAA level and subjective responses to infant cry were assessed. Results: Multilevel regression analyses revealed that trait attachment-anxiety moderated the effect of spousal presence on sAA. Specifically, mothers with high attachment-anxiety showed reduced sAA when their spouse was present, which indicates that spousal support is effective for mothers with high attachment-anxiety. Conclusions: Findings from this study translate to promising clinical applications for the management of parenting stress from infant cry.     

The effect of acceleration signal processing for head impact numeric simulations

Brain injury research in sport employs a variety of physical models equipped with accelerometers. These acceleration signals are commonly processed using filters. The purpose of this research was to determine the effect of applying filters with different cutoff frequencies to the acceleration signals used as input for finite element modeling of the brain. Signals were generated from reconstructions of concussion events from American football and ice hockey in the laboratory using a Hybrid III headform. The resulting acceleration signals were used as input for the University College Dublin Brain Trauma Model after being processed with filters. The results indicated that using a filter with a cutoff of 300 Hz or higher had little effect on the resulting strain measures. In some cases there was some effect of the filters on the peak linear (8–30g) and rotational measures (1000–4000 rad/s²), but little effect on the finite element strain result (approximately 2–6 %). The short duration and high magnitude accelerations, such as the puck impact, were most affected by the cutoff frequency of different filters.     

A comparison of the capacity of ice hockey goaltender masks for the protection from puck impacts

Goaltenders in ice hockey are the only players that are on the ice for the entire game. Their position exposes them to impacts from collisions with other players, falls to the ice, and puck impacts. In competitive ice hockey leagues, head injuries resulting from puck impacts have been reported with some cases resulting in ending the player’s career. Considerable research has been conducted to assess the performance of hockey helmets; however, few have assessed the performance of goaltenders’ masks. The purpose of this study was to compare the capacity of four goaltenders’ masks for the protection from puck impact as measured by head acceleration and peak force. A Hybrid III headform was fitted with four different goaltender masks and impacted with a hockey puck in three locations at 25 m/s. The masks were found to vary in the level of protection they offered as the mask with the thickest liner resulted in lower forces than the thinnest mask for side impacts; however, the thinnest mask resulted in the lowest force for front impacts. Despite performance differences at specific locations, no one mask proved to be superior as peak acceleration and peak force values did not exceed the thresholds necessary for concussion.     

大学的治权:理念和资金的关系

大学面临着一个混乱的时代，许多国家的大学都为数量、质量、治权和经营的问题所困扰。本试图从分析大学理念和资金的关系入手，解剖大学治权的深层结构、所存在的问题和未来发展的方向。     

The Science of Human Interaction and Teaching

There is a missing link between our understanding of teaching as high‐level social phenomenon and teaching as a physiological phenomenon of brain activity. We suggest that the science of human interaction is the missing link. Using over one‐million days of human‐behavior data, we have discovered that collective activeness (CA), which indicates the simple high‐frequency‐motion ratio of a group to total time, plays a fundamental role. Even solo‐work performance, such as telephone‐sales success rate, is more influenced by CA than by one's individual skill level, which has been the conventional target of employee efficiency education. CA is experimentally found to drive people collectively to challenge for greater performance and happiness through a synchronized proactive mind. This is, in fact, deeply related to understanding the question “What is teaching?”     

Empirical analysis of evolution of product architecture: Fanuc numerical controllers from 1962 to 1997

Almost all of the existing studies on product architecture adopt the research framework of comparing the advantages and disadvantages of modular architecture with those of integral architecture. In this paper, we attempt to propose an evolutionary perspective of product architecture. In order to consider the evolution of a product architecture, we analyze the history of Fanuc numerical controllers regarding the evolution of NC architecture from 1962 to 1997. Then we can derive the following hypotheses concerning the evolution of the product architecture. First, the product architecture basically evolves from the integral architecture to the module architecture, and then in the direction of open architecture. Second, in specific circumstances this change does not always progress in the same direction. When epoch-making technology, such as the microprocessor, is incorporated into the product system the direction of the progress in architecture may be reversed from the module to the integral.     

A new algorithm based on metaheuristics for data clustering

This paper presents a new algorithm for clustering a large amount of data.We improved the ant colony clustering algorithm that uses an ant’s swarm intelligence,and tried to overcome the weakness of the classical cluster analysis methods.In our proposed algorithm,improvements in the efficiency of an agent operation were achieved,and a new function "cluster condensation" was added.Our proposed algorithm is a processing method by which a cluster size is reduced by uniting similar objects and incorporating them into the cluster condensation.Compared with classical cluster analysis methods,the number of steps required to complete the clustering can be suppressed to 1% or less by performing this procedure,and the dispersion of the result can also be reduced.Moreover,our clustering algorithm has the advantage of being possible even in a small-field cluster condensation.In addition,the number of objects that exist in the field decreases because the cluster condenses;therefore,it becomes possible to add an object to a space that has become empty.In other words,first,the majority of data is put on standby.They are then clustered,gradually adding parts of the standby data to the clustering data.The method can be adopted for a large amount of data.Numerical experiments confirmed that our proposed algorithm can theoretically applied to an unrestricted volume of data.