601 research outputs found
異なるスポーツ競技種目のエキスパート・コーチを対象としたコーチング・コンセプトの定性的分析
Ericsson等(1993)は、スポーツ、音楽、芸術、科学等、様々な領域における卓越したパフォーマンスが、10年以上に渡って継続的に蓄積された合理的で構造的な練習(deliberate practice)によるとする研究成果を報告している。この合理的で構造的な練習とは、「現在のパフォーマンスを向上させることのみが目的とされた活動」であり、「高度に構造化されており、楽しみを伴わないが故に遊びとは区別され」、また「直接的な報酬を伴わないため仕事とは異なる活動」と定義づけられている(Ericsson等、1993)。こうした「熟達化」解釈の文脈の中で、視点を卓越したパフォーマーから指導者へと移した場合、指導者の役割は「選手が合理的な構造的練習に専心するよう様々な阻害要因を取り除くこと」にあると考えられる(Salmela、1996)。本稿の目的は、異なるスポーツ競技種目の日本人エキスパートコーチを対象とし、彼等彼女等がもつコーチング・コンセプトを定性的に掘り起こし分析することにある。20名のコーチを対象に一人約90分間、1対1の半構造的自由回答的調査面接を実施した。調査面接後直ちに作成されたトランスクライブ・データをもとに、Cote等(1993)による定性的データ分析法を用いた分析作業を行った結果、empowering(自己統制への委譲)、directing(目的達成への教示)、およびorganizing(環境設定)の3つの大カテゴリーが抽出された。各カテゴリーの分析結果から、異なる競技種目の日本人エキスパート・コーチは選手の卓越性獲得に向け、選手自身による自己統制を形成すると同時に、コーチ自身による徹底した目的追求を合理的に追求し、選手と指導者を取り巻く環境を最大限改善していくという構図が明らかにされた。そこでは環境、動機づけ、および専心性の3領域に存在する卓越性獲得の阻害要因を最小限にとどめ、合理的で構造的な練習に選手が継続的に専心できるよう具体的な行動が発揮されている点が確認された。The purpose of this study was to describe the perceptions of coaching concepts of professional coachies in Japan. Fifteen professional coaches served as participants for this study . In-depth, open-ended interviews were conducted with twenty coaches, and the data. The inductive analysis process resulted in regrouping these interview transcripts into three categories which show a significant agreement between coaches\u27 perceptions of the concepts on how they evaluated their coaching activities in relation to performance enhancement of the players and how therole of deliberate practice affects the development of expertise in Japan: 1) empowering, 2) directing, and 3) organizing. For example, the requirement of task analysis and rationalizing training were essential parts of deliberate practice. In addition, it is important to explain the vision and to keep physical and human resources in good condition to direct the plaers to go through deliberate practice and attain their ultimate goal. The strong relationship between empowering, directing, and organizing indicates that coaches direct players to deloberate practice as a way of overcoming the three constrants for talent development: motivation, effort, and resource.論
Genome-Wide Linkage Analysis of Human Auditory Cortical Activation Suggests Distinct Loci on Chromosomes 2, 3, and 8
Neural processes are explored through macroscopic neuroimaging and microscopic molecular measures, but the two levels remain primarily detached. The identification of direct links between the levels would facilitate use of imaging signals as probes of genetic function and, vice versa, access to molecular correlates of imaging measures. Neuroimaging patterns have been mapped for a few isolated genes, chosen based on their connection with a clinical disorder. Here we propose an approach that allows an unrestricted discovery of the genetic basis of a neuroimaging phenotype in the normal human brain. The essential components are a subject population that is composed of relatives and selection of a neuroimaging phenotype that is reproducible within an individual and similar between relatives but markedly variable across a population. Our present combined magnetoencephalography and genome-wide linkage study in 212 healthy siblings demonstrates that auditory cortical activation strength is highly heritable and, specifically in the right hemisphere, regulated oligogenically with linkages to chromosomes 2q37, 3p12, and 8q24. The identified regions delimit as candidate genes TRAPPC9, operating in neuronal differentiation, and ROBO1, regulating projections of thalamocortical axons. Identification of normal genetic variation underlying neurophysiological phenotypes offers a non-invasive platform for an in-depth, concerted capitalization of molecular and neuroimaging levels in exploring neural function.Peer reviewe
Glomerular sclerosis in kidneys with congenital nephrotic syndrome (NPHS1)
Congenital nephrotic syndrome of the Finnish type (NPHS1) is a rare genetic disease caused by mutations in the NPHS1 gene encoding a major podocyte slit-diaphragm protein, nephrin. Patients with NPHS1 have severe nephrotic syndrome from birth and develop renal fibrosis in early childhood. In this work, we studied the development of glomerular sclerosis in kidneys removed from 4- to 44-month-old NPHS1 patients. The pathological lesions and expression of glomerular cell markers were studied in nephrectomized NPHS1 and control kidneys using light and electron microscopy and immunohistochemistry. An analysis of 1528 glomeruli from 20 patients revealed progressive mesangial sclerosis and capillary obliteration. Although few inflammatory cells were detected in the mesangial area, paraglomerular inflammation and fibrosis was common. The podocytes showed severe ultrastructural changes and hypertrophy with the upregulation of cyclins A and D1. Podocyte proliferation, however, was rare. Apoptosis was hardly detected and the expression of antiapoptotic B-cell lymphoma-2 and proapoptotic p53 were comparable to controls. Moderate amounts of podocytes were secreted into the urine of NPHS1 patients. Shrinkage of the glomerular tuft was common, whereas occlusion of tubular opening or protrusion of the glomerular tuft into subepithelial space or through the Bowman's capsule were not detected. The results indicate that, in NPHS1 kidneys, the damaged podocytes induce progressive mesangial expansion and capillary obliteration. Podocyte depletion, glomerular tuft adhesion, and misdirected filtration, however, seem to play a minor role in the nephron destruction
Duplication and Diversification of Dipteran Argonaute Genes, and the Evolutionary Divergence of Piwi and Aubergine
Genetic studies of Drosophila melanogaster have provided a paradigm for RNA interference (RNAi) in arthropods, in which the microRNA and antiviral pathways are each mediated by a single Argonaute (Ago1 and Ago2) and germline suppression of transposable elements is mediated by a trio of Piwi-subfamily Argonaute proteins (Ago3, Aub, and Piwi). Without a suitable evolutionary context, deviations from this can be interpreted as derived or idiosyncratic. Here we analyze the evolution of Argonaute genes across the genomes and transcriptomes of 86 Dipteran species, showing that variation in copy number can occur rapidly, and that there is constant flux in some RNAi mechanisms. The lability of the RNAi pathways is illustrated by the divergence of Aub and Piwi (182-156Ma), independent origins of multiple Piwi-family genes in Aedes mosquitoes (less than 25Ma), and the recent duplications of Ago2 and Ago3 in the tsetse fly Glossina morsitans. In each case the tissue specificity of these genes has altered, suggesting functional divergence or innovation, and consistent with the action of dynamic selection pressures across the Argonaute gene family. We find there are large differences in evolutionary rates and gene turnover between pathways, and that paralogs of Ago2, Ago3, and Piwi/Aub show contrasting rates of evolution after duplication. This suggests that Argonautes undergo frequent evolutionary expansions that facilitate functional divergence.Peer reviewe
Repeated duplication of Argonaute2 is associated with strong selection and testis specialization in Drosophila:Adaptive specialization of Drosophila Argonaute2 duplicates
Argonaute2 (Ago2) is a rapidly evolving nuclease in the Drosophila melanogaster RNA interference (RNAi) pathway that targets viruses and transposable elements in somatic tissues. Here we reconstruct the history of Ago2 duplications across the D. obscura group and use patterns of gene expression to infer new functional specialization. We show that some duplications are old, shared by the entire species group, and that losses may be common, including previously undetected losses in the lineage leading to D. pseudoobscura. We find that while the original (syntenic) gene copy has generally retained the ancestral ubiquitous expression pattern, most of the novel Ago2 paralogs have independently specialized to testis-specific expression. Using population genetic analyses, we show that most testis-specific paralogs have significantly lower genetic diversity than the genome-wide average. This suggests recent positive selection in three different species, and model-based analyses provide strong evidence of recent hard selective sweeps in or near four of the six D. pseudoobscura Ago2 paralogs. We speculate that the repeated evolution of testis specificity in obscura group Ago2 genes, combined with their dynamic turnover and strong signatures of adaptive evolution, may be associated with highly derived roles in the suppression of transposable elements or meiotic drive. Our study highlights the lability of RNAi pathways, even within well-studied groups such as Drosophila, and suggests that strong selection may act quickly after duplication in RNAi pathways, potentially giving rise to new and unknown RNAi functions in nonmodel species
A multilevel layout algorithm for visualizing physical and genetic interaction networks, with emphasis on their modular organization
The Nature and Conceptualisation of Career Transitions in Sport
First paragraph: While an athlete’s sports career may seem to develop in a smooth and continuous way from beginning to end, it is in fact characterized by specific phases and transitions. Asked to describe its development, athletes highlight their athletic career, for example, in terms of specific moments or situations which occurred throughout their career (Wylleman & De Knop, 1997a,b). These moments or situations do not only require athletes to cope with specific changes, but are also perceived by the athletes to influence the quality of their participation at their current competitive level. The occurrence of phases and transitions in the athletic career can also be illustrated by chronologically pin-pointing athletes’ sport achievements (e.g., a first national championship title) and selections (e.g., selection for the national team). Comparison of such developmental data has revealed many similarities in (elite) athletes’ athletic careers (Stambulova, 1998; Wylleman & De Knop, 1998): athletes start out in their sport at the ages of approximately 8 to 12 years-of-age; one or two years later athletes start competing at club level, and go, some three to four years later on to national level; a first selection for a national team occurs somewhere between 17-19 years-of-age, while a first Olympic selection is achieved during their early twenties; and finally, athletes do end their involvement in highlevel competitive sport at approximately 30 years-of-age (3). In fact, researchers have been able to identify a sequence of career developmental phases, not only with elite level athletes, but with talented performers in general, namely an initiation, a development, a mastery, and a post-career phase (e.g., Bloom, 1985; Salmela; 1994)
Morphological changes and riffle-pool dynamics related to flow in a meandering river channel based on a 5-year monitoring period using close-range remote sensing
The maintenance of riffle-pool sequences and morphological changes in the long-term have received little attention in the literature. The aims of this study are to determine morphological changes and riffle-pool maintenance in relation to flow conditions in a meandering river channel over a 5-yr period. Change detection was focused on riffle and pool maintenance in a river reach covering three successive meander bends. Changes in a meandering river channel were studied utilizing detailed digital terrain models and flow data. The results indicated that riffle-pool sequences are maintained by high discharge events and the development of pools and riffles was linked. During high discharges, the riverbed eroded on the concave sides and the inflexion points aggraded, causing riffle–pool sequences, whereas during low discharges, concave sides aggraded and inflexion points eroded, causing pool filling and riffle erosion. While discharge increased, near-bed flow velocities increased faster on the concave sides of the bends than at the inflexion points, becoming higher at a discharge of 8 m3/s, ~20% of the bankfull discharge. Changes in the three successive meander bends were mainly similar, and the geometry of meandering rivers contributed to the locations of riffles and pools. Pools and riffles were not stable in size and shape, but their longitudinal location remained the same, instead of migrating up and down the channel. Morphological changes occurred in meander bends year-round, but they were non-linear. Annual channel change was not similar from year to year owing to different flow regimes and morphological changes during the previous year. However, seasonal detection revealed similarities between high and low discharge periods between the years. Concave sides of meander bends may act to temporarily store sediment; however, storage is preserved only under the effective hydrological discharge.</p
Entrepreneurs’ age, institutions, and social value creation goals: a multi-country study
This study explores the relationship between an entrepreneur's age and his/her social value creation goals. Building on the lifespan developmental psychology literature and institutional theory, we hypothesize a U-shaped relationship between entrepreneurs’ age and their choice to create social value through their ventures, such that younger and older entrepreneurs create more social value with their businesses while middle age entrepreneurs are relatively more economically and less socially oriented with their ventures. We further hypothesize that the quality of a country’s formal institutions in terms of economic, social, and political freedom steepen the U-shaped relationship between entrepreneurs’ age and their choice to pursue social value creation as supportive institutional environments allow entrepreneurs to follow their age-based preferences. We confirm our predictions using multilevel mixed-effects linear regressions on a sample of over 15,000 entrepreneurs (aged between 18 and 64 years) in 45 countries from Global Entrepreneurship Monitor data. The findings are robust to several alternative specifications. Based on our findings, we discuss implications for theory and practice, and we propose future research directions
- …