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1.
This article attempts to outline the neuronal foundations of movement automatization. In particular, it is shown that an increase in automaticity corresponds to processes of synaptic plasticity in the corticostriatal and corticocortical system. This mechanism is supposed to induce changes in the neuronal representations of the respective skill. Furthermore, the role of phasic dopamine release will be discussed with respect to its modulating effect on processes of plasticity. 相似文献
2.
This paper proposes a new scheme for ensuring data consistency in unstructured p2p networks where peers can subscribe to multiple content types (identified by labels) and are rapidly informed of content updates. The idea is based on using a static tree structure, the Cluster-K+ tree, that maintains most of the structural information about peers and labels. A label denotes a set of replicated or co-related data in the network. The Cluster-K+ tree provides efficient retrieval, addition, deletion and consistent updates of labels. Our proposed structure guarantees a short response search time of O(H + K), where H denotes the height of the tree and K the degree of an internal tree node. We present theoretical analytic bounds for the worst-case performance. To verify the bounds, we also present experimental results obtained from a network simulation. The results demonstrate that the actual performance of our system is significantly better than the theoretical bounds. 相似文献
3.
Jan Wilke Johannes Fleckenstein Frieder Krause Lutz Vogt Winfried Banzer 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(2):151-161
Fatigue protocols have been used over the years to examine muscular exhaustion. As an alternative to approaches in laboratory settings, functional agility protocols claiming to mimic the multifaceted loads of athletic activity have been proposed. This study aimed to examine the effects of a functional agility short-term fatigue protocol (FAST-FP) on neuromuscular function. Twenty-eight healthy sports students (15 males, aged 24.3 ± 2.4 years) completed the FAST-FP, which consists of four components: three counter-movement jumps (90% of individual maximum), a 20-s bout of step-ups, three bodyweight squats and an agility run. Tasks were repeated until the participants no longer achieved the required jump height in two consecutive sets. Outcomes (pre-post) encompassed subjective exhaustion (visual analogue scale [VAS]), maximum isometric voluntary force of the knee extensors (MIVF), reactive strength index (RSI), mean power frequency (MPF, measured using surface electromyography) and maximum knee range of motion (ROM). Post-intervention, VAS (+54 mm) increased significantly, while MIVF (–6.1%), RSI (–10.7%) and MPF (–4.1%) were reduced (p < 0.05). No changes were observed for ROM (p > 0.05). The FAST-FP induces small-to-moderate impairments in neuromuscular function and considerable self-perceived fatigue. Current evidence on exhaustion developing in team sports suggests that this magnitude of fatigue is similar. The protocol might thus be valuable in the evaluation of treatments counteracting post-match fatigue in team sports. 相似文献
4.
We discuss a microfluidic system in which (programmable) local electric fields originating from embedded and protected electrodes are used to control the formation and merging of droplets in a microchannel. The creation of droplets-on-demand (DOD) is implemented using the principle of electrowetting. Combined with hydrodynamic control, the droplet size and formation frequency can be varied independently. Using two synchronized DOD injectors, merging-on-demand (MOD) is achieved via electrocoalescence. The efficiency of MOD is 98% based on hundreds of observations. These two functionalities can be activated independently. 相似文献
5.
Frieder Meyer-Krahmer 《Research Policy》1984,13(3):175-182
The Fraunhofer-Institut für Systemtechnik und Innovationsforschung (ISI) is at present engaged in evaluating a number of technology policy programs designed to promote research, development and innovation in small and medium-sized firms. These studies try to determine the extent to which these programmes have an impact upon the innovative activities of firms.In this connection, it was also attempted to measure the innovation output. The level of innovation of a firm is innovation ouput. The level of innovation of a firm is procedure involves a number of problems (self-assessment of firms in view of insufficient market transparency, distortion due to self-portraits reflecting the firms' own interests). We tried to mitigate such distortions by two approaches. Firstly, firms were asked for their technologically new products, the term “new” being applied (a) to the firm and (b) to the areas of product application. As a result of this two-tier procedure, firms supplied rather realistic answers. Secondly, supplementary questions were asked about sales figures, the competitive technological situation (nationally and internationally), expenditure on R&D, patents, stages of innovation, aims of innovation, etc.The paper presents the results obtained to date on the innovation output of firms within the framework of an evaluation of the largest programme at present devoted to promoting R&D and innovation in small and medium-sized firms . The results are based on a representative sample of approximately 4,500 small and medium-sized firms (up to 1,00 employees) with R&D activities in the Federal Republic of Germany. 相似文献
6.
Sachin Nair Jun Gao Qirong Yao Michael H G Duits Cees Otto Frieder Mugele 《国家科学评论(英文版)》2020,7(3):620
Confocal Raman microscopy is important for characterizing 2D materials, but its low throughput significantly hinders its applications. For metastable materials such as graphene oxide (GO), the low throughput is aggravated by the requirement of extremely low laser dose to avoid sample damage. Here we introduce algorithm-improved confocal Raman microscopy (ai-CRM), which increases the Raman scanning rate by one to two orders of magnitude with respect to state-of-the-art works for a variety of 2D materials. Meanwhile, GO can be imaged at a laser dose that is two to three orders of magnitude lower than previously reported, such that laser-induced variations of the material properties can be avoided. ai-CRM also enables fast and spatially resolved quantitative analysis, and is readily extended to 3D mapping of composite materials. Since ai-CRM is based on general mathematical principles, it is cost-effective, facile to implement and universally applicable to other hyperspectral imaging methods. 相似文献
7.
The cortico-basal ganglia loops play an important role in the organization of human motor function. This article presents findings and thoughts according to which plasticity processes in these cortico-striatal loops and in the striatum mediate long-lasting reorganization of cortical motor representations and possess relevance for sport-specific motor activity. The correlations described point to the great significance of unexpected success of motor activity for motor learning processes. 相似文献
8.
Frieder Meyer-Krahmer 《Research Policy》1989,18(6)
The incorporation of an evaluation procedure in a growing number of innovation policy programmes has now become an accepted feature in the public management of many countries. There already exists substantial experience on the conduct of such evaluations. The purpose of this paper is to present some sample evaluations of measures to promote innovation in a number of European OECD countries (Federal Republic of Germany, France, Netherlands, Sweden). Reference will be made to four of them to illustrate the diversity of the evaluative approaches applied to the wide spectrum of measures to promote innovation. Each of these examples will be studied in detail in order to identify their characteristic features, particularly with attention to their causes, performance and their use in political decision processes.A conceptual framework will be presented in order to propose a typology of various forms of evaluation and to characterize the four case studies. It shows that concept and process of evaluations are strongly influences by the specific context and consensus or dissent on objectives and resources. The case studies give a clearer insight into the factors determining the use of results of evaluations; and to what extent the role of evaluations varies from pure legitimation to a systematic and rational basis for decision making in the area of technology policy.Innovation policy consists of government actions towards technological developments and their implementation in the economy. Innovation, in this case, is defined as the development of technologically new or improved products or techniques and their commercialization in the market or implementation within production. Often evaluation means the examination and assessment of the mode of action and of the effectiveness of government innovation policy. However, finding a general interpretation of the expression “evaluation of an innovation policy” presents greater difficulty, and here wide divergences are evident. In the Federal Republic of Germany and the Netherlands, the term encompasses all forms of monitoring and assessing the operation and/or the effectiveness of an innovation policy. In Sweden, evaluation usually means performance of the a posteriori analysis of a measure. The terms “ex ante evaluation” and “follow-up evaluation” are respectively used for the explicit designation of prospective and retrospective analyses. In France, the term “evaluation” is associated with the notion of value. It often carries the connotation of a value assessment with the full monitoring implications of that expression. 相似文献
9.
Against a background of deteriorating national and international economic conditions, increasing importance is being attached by political administrations to the innovative capacities of small and medium-sized firms with respect to the employment situation and to international competitiveness. Consequently, government support of research, development and innovation in these companies has taken a marked upward turn since the late seventies, both in the Federal Republic of Germany and in other industrialized Western countries.The actual impacts of some of these programmes are at present under study by the Fraunhofer-Institut für Systemtechnik und Innovationsforschung (ISI). This paper is an outline of the results of a study of the largest current programme funding R&D and innovation in small and medium-sized firms by offering grants towards the costs of R&D personnel. The impact analysis is being conducted in two rounds: the first round of studies, which is the subject of this report, took place in 1980/1981 and was designed to examine the discernible short-term effects and characteristics of the programme. The second round is planned for 1983/1984 as a summary of the impacts of the programme over the first five years of its term of effect.The subjects of investigation are the quantitative and qualitative changes in R&D activities caused by the programme in the firms under study and the contribution the programme can make to strengthen innovative and competitive capabilities. The conditions underlying the programme are reviewed critically, especially in order to see whether the barriers to innovation and the weak spots assumed did in fact exist in the firms examined. The administrative management, “free rider”-effects, and factors restricting impacts are investigated along with such questions as whether firms located in peripheral regions were reached by the programme to the same extent as firms in conurbation areas. Furthermore, the reasons for non-participation of firms are analyzed.The example of the federal programme funding R&D personnel thus is used in this impact analysis in an attempt to provide empirical data on the significance, the range, and the limits of such a government instrument promoting R&D and innovation in small and medium-sized firms. 相似文献
10.
Living cells are a fascinating demonstration of nature’s most intricate and well-coordinated micromechanical objects. They crawl, spread, contract, and relax—thus performing a multitude of complex mechanical functions. Alternatively, they also respond to physical and chemical cues that lead to remodeling of the cytoskeleton. To understand this intricate coupling between mechanical properties, mechanical function and force-induced biochemical signaling requires tools that are capable of both controlling and manipulating the cell microenvironment and measuring the resulting mechanical response. In this review, the power of microfluidics as a functional tool for research in cell mechanics is highlighted. In particular, current literature is discussed to show that microfluidics powered by soft lithographic techniques offers the following capabilities that are of significance for understanding the mechanical behavior of cells: (i) Microfluidics enables the creation of in vitro models of physiological environments in which cell mechanics can be probed. (ii) Microfluidics is an excellent means to deliver physical cues that affect cell mechanics, such as cell shape, fluid flow, substrate topography, and stiffness. (iii) Microfluidics can also expose cells to chemical cues, such as growth factors and drugs, which alter their mechanical behavior. Moreover, these chemical cues can be delivered either at the whole cell or subcellular level. (iv) Microfluidic devices offer the possibility of measuring the intrinsic mechanical properties of cells in a high throughput fashion. (v) Finally, microfluidic methods provide exquisite control over drop size, generation, and manipulation. As a result, droplets are being increasingly used to control the physicochemical environment of cells and as biomimetic analogs of living cells. These powerful attributes of microfluidics should further stimulate novel means of investigating the link between physicochemical cues and the biomechanical response of cells. Insights from such studies will have implications in areas such as drug delivery, medicine, tissue engineering, and biomedical diagnostics. 相似文献