Low-intensity electrical muscle stimulation induces significant increases in muscle strength and cardiorespiratory fitness

The aim of this study was to investigate the effect of low-intensity exercise training using belt electrode skeletal muscle electrical stimulation on muscle strength and cardiorespiratory fitness in healthy subjects. Nineteen healthy subjects were allocated into control or intervention groups; in both groups the participants kept regular physical activity while the intervention group underwent 30 min B-SES training at 3–4 METs for four weeks. Knee extensor muscle strength and cardiorespiratory endurance during incremental exercise test were measured at baseline and after four weeks for all participants. The relative change of knee extensor muscle strength in the intervention group was significantly higher than control group (p?p?相似文献   

Age-Related Changes in Soluble Vascular Endothelial Growth Factor Receptor 1 (sVEGFR1) and Receptor 2 (sVEGFR2) in Healthy Japanese Subjects

We measured serum soluble vascular endothelial growth factor receptor 1 (sVEGFR1) and receptor 2 (sVEGFR2) levels in healthy Japanese individuals in order to establish a reference value using a specific ELISA. Significant differences were observed in serum sVEGFR1 and sVEGFR2 levels between children and adults. To demonstrate the usefulness of the reference value for children, we measured serum sVEGFR1 and sVEGFR2 levels in children with diarrhea positive (D+) hemolytic uremic syndrome (HUS) as a preliminary study. Serum sVEGFR2 levels in children with HUS were markedly higher than those in healthy children from the onset of D + HUS. The reference value for healthy children in the present study will allow normal and pathological conditions to be discriminated from each other in future study     

A robot is watching me!: Five-year-old children care about their reputation after interaction with a social robot

Since robots are becoming involved in children's lives, it is urgent to determine how children perceive robots. The present study assessed whether Japanese 5-year-olds care about their reputation when interacting with a social robot. Children were given stickers and asked to divide them between themselves and an absent recipient. Results revealed that children (N = 112, 55 boys, 57 girls) strategically shared more stickers when being watched by a social interactive robot than by an attentional but non-interactive robot or a still robot. Additionally, children (N = 36, 18 boys, 18 girls) attributed higher psychological properties to social robots. This study is the first to show that 5-year-olds care about their reputations from social robots.     

Technology survey and invalidity search: A comparative study of different tasks for Japanese patent document retrieval

A comparative study of two types of patent retrieval tasks, technology survey and invalidity search, using the NTCIR-3 and -4 test collections is described, with a focus on pseudo-feedback effectiveness and different retrieval models. Invalidity searches are peculiar to patent retrieval tasks and feature small numbers of relevant documents and long queries. Different behaviors of effectiveness are observed when applying different retrieval models and pseudo-feedback. These different behaviors are analyzed in terms of the “weak cluster hypothesis”, i.e., terminological cohesiveness through relevant documents.     

汉语“站立”义词的现状与历史

表示站立意义的词属于人类语言的基本词。本文描述汉语站立义词的现实分布和历时演变,并尝试对两者的关系作出解释。现代方言中表站立义的主导词有3个:站、立、徛。它们的分布特点是:站分布最广,大多数北方方言说站,此外还散见于非官话区的部分方言点;徛密集分布于东南部的吴语、徽语、赣语、湘语、客家话、广西平话、粤语、闽语地区;立则呈零散分布,散落在官话、晋语、吴语、赣语、湘语、湖南乡话和广西平话各区。这3个词在汉语史上的情况大致是:立从有文字记载的上古早期起一直是影响最大的通语词,直到明代以后才在大部分北方地区被站替换;徛(倚)用作站立义始见于战国,历史上可能作为一个方言词一直存在于南部广大地区;站始见于唐代,明代以后在广大的官话区逐渐取代立成为新的通语词。站很可能是所谓的长江型词,即兴起于江淮流域而后往北扩散。     

Novel mathematical model to estimate ball impact force in soccer

To assess ball impact force during soccer kicking is important to quantify from both performance and chronic injury prevention perspectives. We aimed to verify the appropriateness of previous models used to estimate ball impact force and to propose an improved model to better capture the time history of ball impact force. A soccer ball was fired directly onto a force platform (10 kHz) at five realistic kicking ball velocities and ball behaviour was captured by a high-speed camera (5,000 Hz). The time history of ball impact force was estimated using three existing models and two new models. A new mathematical model that took into account a rapid change in ball surface area and heterogeneous ball deformation showed a distinctive advantage to estimate the peak forces and its occurrence times and to reproduce time history of ball impact forces more precisely, thereby reinforcing the possible mechanics of ‘footballer’s ankle’. Ball impact time was also systematically shortened when ball velocity increases in contrast to practical understanding for producing faster ball velocity, however, the aspect of ball contact time must be considered carefully from practical point of view.     

Segmental dynamics of soccer instep kicking with the preferred and non-preferred leg

Abstract

Detailed time-series of the resultant joint moments and segmental interactions during soccer instep kicking were compared between the preferred and non-preferred kicking leg. The kicking motions of both legs were captured for five highly skilled players using a three-dimensional cinematographic technique at 200 Hz. The resultant joint moment (muscle moment) and moment due to segmental interactions (interaction moment) were computed using a two-link kinetic chain model composed of the thigh and lower leg (including shank and foot). The mechanical functioning of the muscle and interaction moments during kicking were clearly illustrated. Significantly greater ball velocity (32.1 vs. 27.1 m · s^?1), shank angular velocity (39.4 vs. 31.8 rad · s^?1) and final foot velocity (22.7 vs. 19.6 m · s^?1) were observed for the preferred leg. The preferred leg showed a significantly greater knee muscle moment (129.9 N · m) than the non-preferred leg (93.5 N · m), while no substantial differences were found for the interaction moment between the two legs (79.3 vs. 55.7 N · m). These results indicate that the highly skilled soccer players achieved a well-coordinated inter-segmental motion for both the preferred and non-preferred leg. The faster leg swing observed for the preferred leg was most likely the result of the larger muscle moment.     

Pigeons see the Ponzo illusion

Three experiments were performed to address factors contributing to the Ponzo illusion. In Experiment 1, pigeons learned to peck at the longer of two bars in varying line contexts. When these lines converged, the birds had difficulty in learning several patterns in which a Ponzo illusion would reduce the perceived difference. In Experiment 2, the subjects chose one response if a stimulus bar was longer than a predetermined length and a second response for shorter bars. The subjects were more likely to choose “long” as the stimulus bar approached the apex of converging lines. These results suggested that pigeons experience the Ponzo illusion. In Experiment 3, the effects of contexts that did and did not form a texture gradient were compared. The magnitude of the illusion did not differ according to context lines. This result failed to support a perspective theory of the Ponzo illusion.     

Students’ understanding of the structure of deductive proof

While proof is central to mathematics, difficulties in the teaching and learning of proof are well-recognised internationally. Within the research literature, a number of theoretical frameworks relating to the teaching of different aspects of proof and proving are evident. In our work, we are focusing on secondary school students learning the structure of deductive proofs and, in this paper, we propose a theoretical framework based on this aspect of proof education. In our framework, we capture students’ understanding of the structure of deductive proofs in terms of three levels of increasing sophistication: Pre-structural, Partial-structural, and Holistic-structural, with the Partial-structural level further divided into two sub-levels: Elemental and Relational. In this paper, we apply the framework to data from our classroom research in which secondary school students (aged 14) tackled a series of lessons that provided an introduction to proof problems involving congruent triangles. Using data from the transcribed lessons, we focus in particular on students who displayed the tendency to accept a proof that contained logical circularity. From the perspective of our framework, we illustrate what we argue are two independent aspects of Relational understanding of the Partial-structural level, those of universal instantiation and hypothetical syllogism, and contend that accepting logical circularity can be an indicator of lack of understanding of syllogism. These findings can inform how teaching approaches might be improved so that students develop a more secure understanding of deductive proofs and proving in geometry.