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991.
Previous research has demonstrated that Parkinson's disease patients have an increased susceptibility to response conflict. In the present study, the authors investigate whether Parkinson's patients have a similar sensitivity to interference from observed movements. In all, 10 patients and 10 controls performed horizontal and vertical arm movements while watching a video of either a person performing similar movements or a moving dot. Movements were performed in the same plane (congruent) and orthogonal to the observed movement (incongruent). The off-axis variance of movements was our index of interference. Although patients tended to exhibit more off-axis variability than did controls, both groups demonstrated similar congruence effects, with greater variance in incongruent conditions. These results indicated that increased susceptibility to interference in Parkinson's disease does not extend to interference from observed movements.  相似文献   
992.
Frequency-related response characteristics of the mechanisms controlling stabilization of the head in 10 elderly subjects were compared with response characteristics in 8 young adults. Angular velocity of the head with respect to the trunk and EMG responses of 2 neck muscles were recorded in 10 seated subjects during pseudorandom rotations of the trunk in the sagittal plane at frequencies of 0.35 to 3.05 Hz. Subjects were required to actively stabilize their heads with (VS) and without (NV) visual feedback so that voluntary mechanisms and the influence of vision could be tested. Reflex mechanisms were examined when subjects were distracted by a mental calculation task during rotations in the dark (MA). Age emerged as an influential factor in the performance of head stabilization mechanisms, and decrements in performance were even more pronounced in the older as compared with younger elderly subjects. Age effects could be seen in the (a) diminished ability to voluntarily stabilize the head, particularly with the absence of vision, (b) impaired ability to stabilize the head when cognitively distracted, and (c) appearance of a resonant response of the head. Control of head stabilization shifted from reflex mechanisms to system mechanics, probably as a result of age-related changes in the integrity of the sensory systems. The elderly's system mechanics could not effectively compensate for the disturbances, however, and instability was the result.  相似文献   
993.
We investigated perception of the extent of an object held in the hand or attached to the head during walking. Participants wielded an occluded, weighted rod by hand and by head and reported the perceived location of the rod end (relative to a virtual vertical line) while walking and while standing. There was an unexpected effect of body part on perceived location of the rod end. In particular, participants stood or walked so that the rod end was farther away from the vertical line when wielding with the head than wielding with the hand. It is possible that differences between the tasks and the relative costs of a collision influenced the locomotory behavior in each condition.  相似文献   
994.
Gray’s reinforcement sensitivity theory, consisting of the behavioral inhibition (BIS) and behavioral activation (BAS), is frequently used to represent basic dimensions of psychopathology. However, notably few investigations have examined the link between the BIS/BAS and symptoms of personality disorder (PD). Although the Fight-Flight-Freeze System has emerged in the revised model as an important aspect of motivation, the BIS (linked to anxiety) and BAS (linked to impulsivity) have been the primary foci. The current investigation uses a dimensional measure of PD, the schedule for nonadaptive and adaptive personality (SNAP; Clark, 1993) applied to two independent samples of English-speaking participants: undergraduates (n = 276) and clinical patients (n = 47). Results were consistent across both samples, demonstrating that symptoms of Cluster B PDs are indicative of high BAS levels whereas symptoms of Cluster C PDs are characterized by high BIS levels.  相似文献   
995.
When Darwin wrote his ‘On the origin of species…” (1859) he focused on evolution as a property of living organisms in interaction with abiotic and biotic elements in the world. This viewpoint is still dominant amongst biologists. For particle physicists and cosmologists evolution refers to a larger scale, ranging from quarks and atoms to galaxies, stars and planets (i.e. Pagels 1985, Hawking 1988). To close the gap between such different viewpoints, a wide range of perspectives on an interdisciplinary understanding of system development has been published (i.e. Teilhard de Chardin 1966, von Bertalanffy 1968, Varela 1979, Prigogine and Stengers 1984, Laszlo 1996). As an integrative concept, the construction of nature from a hierarchy of system layers forms a central tenet in general system research and the stepwise construction of this layered hierarchy can be regarded as an interdisciplinary evolution theory. Surprisingly, the literature offers no unequivocal rules to recognise a multilayer hierarchy in nature. This presents an obstacle for interdisciplinary approaches to evolution.

Searching a solution to part of the above hierarchy problem, the present paper is dedicated to the analysis of a special kind of layering in natural systems, which is based on transitions between ‘building block’ systems. To identify these building blocks, and the transitions from building block x at level A, to building block y at level B, the focus of this study is further limited to ‘hypercydic dynamics’ and ‘containment’. On the basis of these criteria, a hierarchy is created which shows no possibilities for ‘bypasses’. It connects hadrons to atoms, atoms to cells, and cells to neural networks. Implications of this hierarchy for system studies and evolution are discussed.  相似文献   
996.
997.
Two alternative scenarios on the future of the nation state are presented in order to discuss the concepts of national identity as well as of political system legitimacy. At the core is the question to what extent the nation state will become obsolescent if not obsolete as a function of international interdependence. Fukuyama considers national identity a cultural phenomenon alien to democracy as the ultimate form of government. Guéhenno, in contrast, believes that the erosion of the nation state and of national identity will bring about the end of democracy. The disagreement rests on the assumption whether the political systems will be able to retain their autonomy allowing them to maintain or expand individual liberty and collective freedom.  相似文献   
998.

Fundamental changes in sciences offer new perspectives for the management of complexity. Increased complexity in society, economics, and technology requires a new and suitable organization and management. What are the consequences and results for project management? That is the theme of this article. First of all it will given a short introduction to project management, which will be later called “traditional project management” or “project management 1st order (PM-1).” Then, the challenges by the fundamental changes in sciences and the increased complexity in society, economics, and technology will be discussed. It will state that traditional project management cannot solve these challenges. The widespread working-themes and results of the research program “Beyond Frontiers of Traditional Project Management” as an answer to these challenges will be presented at a glance. Subsequently, it will discuss some selected results of the research program:
  • The principle-definition and foundation of “Evolution of 1st and 2nd Order.”

  • The Evolution of 1st Order and the impact on Project Management methods and processes.

  • Evolution of 2nd Order and the Grand Evolutionary Systems Theory (GEST) of E. Laszlo as also the impact on Project Management methods and processes.

  • Management of crisis: turn a change to advantage or risk-assurance?

Thereafter, the concept of “Project Management Second Order (PM-2)” is presented as a highlighted result of the research program, as a new paradigm in project management, and as an answer to the challenges, described earlier will be explained in detail. Finally, a real example of transfer evolutionary and self-organizational management principles in a real project life will be demonstrated.  相似文献   
999.
Human systems are interacting with, and dependent on, the global ecosystem. These complex interconnected systems have to obey natural laws and system laws in order to remain viable in the long‐term. “Sustainable development” therefore has to adhere to certain principles and constraints which derive partially from physical conditions, partially from principles of (evolving) ecosystems, partially from principles applying to human systems with conscious actors and normative standards. Although “sustainable development” constrains the spectrum of permissible processes, it does not define a final steady state. The development process must be guided by reference to an ethical principle and to the balanced satisfaction of the basic orientors resulting from a system's interaction with its environment. The systems perspective required encompasses a wide range of scientific disciplines, for which a comprehensive bibliography is provided.  相似文献   
1000.
This article illustrates the important scientific role that a systems approach might play within the social sciences and humanities, above all through its contribution to a common language, shared conceptualizations, and theoretical integration in the face of the extreme (and growing) fragmentation among the social sciences (and between the social sciences and the natural sciences). The article outlines a systems theoretic approach, actor-system-dynamics (ASD), whose authors have strived to re-establish systems theorizing in the social sciences (after a period of marginalization since the late 1960s). This is done, in part, by showing how key social science concepts are readily incorporated and applied in social system analysis.  相似文献   
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