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排序方式: 共有156条查询结果,搜索用时 15 毫秒
1.
The purpose of this study was to identify which averaging methods most accurately measures peak cardiorespiratory fitness (CRF) parameters [peak O2 uptake (VO2), peak O2pulse and peak respiratory exchange ratio (RER)] in a sample of healthy children and adolescents. In this cross-sectional multicenter study, we recruited 278 healthy children aged 12–17 years. We compared the mean peak value of three CRF parameters using the recommended averaging methods (30-second block average) with alternative averaging methods such as moving averages or shorter smoothing periods. We also assessed averaging methods for accuracy by individually reviewing breath-by-breath scatter plots. The 30-second block average method resulted in a lower mean peak VO2 and in an increased proportion of underestimated peak values. Using a 30-second moving average significantly increased mean peak values which increased accuracy. Similar results were found for peak RER and peak O2pulse. In conclusion, the currently recommended averaging method (30-second block average) increased the risk of misinterpretation of peak CRF values in children. Using a moving average approach decreased misinterpretation and increased accuracy.  相似文献   
2.
Research-based spin-offs (RBSOs) have become an important aspect of the technology transfer process. Emanating from what is conventionally a non-commercial environment, RBSOs pose major challenges if they are to realise their potential to meet the objectives of their founders and the parent research organisations (PROs) from which they emerge. An important issue is to understand the heterogeneity of RBSOs. This paper reviews the literature on RBSO typologies to develop a taxonomy of RBSOs. We identify common themes in relation to these typologies in relation to (1) spin-off creation and (2) spin-off development. The dimensions that differentiate between firms are the type of resources, the business model and the institutional link. We identify gaps in current typologies in order to propose avenues for future conceptual and empirical research.  相似文献   
3.
As an introduction to the special issue on “emerging nanotechnologies”, this paper puts in perspective contemporary debates and challenges about nanotechnology. It presents an overview of diverse analyses and expectations about this presumably revolutionary set of technological, scientific and industrial developments. Three main lines of argument can then be delineated: first of all, the degree of cumulativeness of science and technologies and the respective roles of newcomers and incumbents in the industrial dynamics; second the knowledge dynamics in nanotechnologies, especially the linkages by science and technology and third the role of institutions (network, geographic agglomeration and job market). It finally discusses methodologies to delineate the field of nanotechnologies and to collect data.  相似文献   
4.
This study examines the effects of teachers' speech and hand gestures on the task performances of students with Attention‐Deficit/Hyperactivity Disorder (ADHD). Forty‐five 7½‐year‐old students clinically diagnosed with ADHD participated in the study. The students were asked to solve three sets of puzzles. The teachers supported the students in the tasks by using three different scaffolding modalities: speech‐only, gesture‐only and speech in conjunction with gestures. The results indicate that when the teachers used the scaffolding that contained gesture components (either speech scaffolding in conjunction with gesture scaffolding or gesture‐only scaffolding), the ADHD students were more responsive, focused longer on the tasks and were more successful in completing the tasks. Moreover, teachers' representational and deictic gestures were found to be the most effective gestures in scaffolding. This study suggests that when teachers' hand gestures are used together with speech, they are a powerful pedagogical means to engage ADHD children in tasks.  相似文献   
5.
The forward skating start is a fundamental skill for male and female ice hockey players. However, performance differences by athlete’s sex cannot be fully explained by physiological variables; hence, other factors such as skating technique warrant examination. Therefore, the purpose of this study was to evaluate the body movement kinematics of ice hockey skating starts between elite male and female ice hockey participants. Male (n = 9) and female (n = 10) elite ice hockey players performed five forward skating start accelerations. An 18-camera motion capture system placed on the arena ice surface captured full-body kinematics during the first seven skating start steps within 15 meters. Males’ maximum skating speeds were greater than females. Skating technique sex differences were noted: in particular, females presented ~10° lower hip abduction throughout skating stance as well as ~10° greater knee extension at initial ice stance contact, conspicuously followed by a brief cessation in knee extension at the moment of ice contact, not evident in male skaters. Further study is warranted to explain why these skating technique differences exist in relation to factors such as differences in training, equipment, performance level, and anthropometrics.  相似文献   
6.
7.
Afforestation in China provides carbon sequestration and prevents soil erosion, but its remote impacts on climate in other regions via the coupling of forest energy fluxes with atmospheric circulation are largely unknown. Here, we prescribe inventory-based forest cover change and satellite-observed leaf area index from 1982 to 2011 in a coupled land-atmosphere model to simulate their biophysical climate effects. Both local and global surface air temperatures show a seasonal contrast in response to past vegetation cover expansion over China: a phenomenon we primarily attribute to a variation of seasonality of vegetation greening. A large cooling in spring results in concurrent decreases in geopotential height over China and zonal wind over Mongolia, causing a dipole structure in the upper troposphere over the Arctic. This accounts for ∼58% of simulated spring warming over the Russian Arctic and ∼61% of simulated spring cooling over the Canadian Artic. Our results imply that spring vegetation dynamics in China may affect climate in northern high latitudes.  相似文献   
8.
This paper provides a new and systematic characterization of 488 universities, from 11 European countries: Finland, France, Germany, Hungary, Italy, Netherlands, Norway, Portugal, Spain, Switzerland and UK. Using micro indicators built on the integrated Aquameth database, we characterize the European university landscape according to the following dimensions: history/foundation of university, dynamics of growth, specialization pattern, subject mix, funding composition, offer profile and productivity.  相似文献   
9.
In this paper, we lay out a relational approach for indexing and retrieving photographs from a collection. The increase of digital image acquisition devices, combined with the growth of the World Wide Web, requires the development of information retrieval (IR) models and systems that provide fast access to images searched by users in databases. The aim of our work is to develop an IR model suited to images, integrating rich semantics for representing this visual data and user queries, which can also be applied to large corpora.  相似文献   
10.
Based on data collected through a complex survey of science and engineering PhD graduates from a UK research-based university, this paper examines the different types of careers and to what extent different types of competences acquired from doctoral education are regarded as valuable in the different career types. The results show that employment outside the conventional technical occupations is the main destination for the survey respondents. This career type is not only successful at retaining its members, but is also the destination of the other career types. Moreover, different types of competences from doctoral education are regarded as relatively more valuable in different career types: knowledge directly tied to subject areas is regarded as more valuable in academia/public research; both knowledge directly tied to subject areas (but more general type of knowledge rather than specialist knowledge in PhD topics) and the more general and transferable skills are regarded as valuable in technical positions in manufacturing; and the general and transferable skills are regarded as more valuable in employment outside the conventional technical occupations. In absolute terms, general analytical skills and problem solving capability acquired from doctoral education are perceived as valuable in all three career types.  相似文献   
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