Fluctuations in cyclic tasks periods is a known characteristic of human motor control. Specifically, long-range fractal fluctuations have been evidenced in the temporal structure of these variations in human locomotion and thought to be the outcome of a multicomponent physiologic system in which control is distributed across intricate cortical, spinal and neuromuscular regulation loops.Combined with long-range correlation analyses, short-range autocorrelations have proven their use to describe control distribution across central and motor components.We used relevant tools to characterize long- and short-range correlations in revolution time series during cycling on an ergometer in 19 healthy young adults. We evaluated the impact of introducing a cognitive task (PASAT) to assess the role of central structures in control organization.Autocorrelation function and detrending fluctuation analysis (DFA) demonstrated the presence of fractal scaling. PSD in the short range revealed a singular behavior which cannot be explained by the usual models of even-based and emergent timing.The main outcomes are that (1) timing in cycling is a fractal process, (2) this long-range fractal behavior increases in persistence with dual-task condition, which has not been previously observed, (3) short-range behavior is highly persistent and unaffected by dual-task.Relying on the inertia of the oscillator may be a way to distribute more control to the periphery, thereby allocating less resources to central process and better managing additional cognitive demands. This original behavior in cycling may explain the high short-range persistence unaffected by dual-task, and the increase in long-range persistence with dual-task. 相似文献
We demonstrate a unique mechanochemical effect – change in surface plastic flow by action of chemical media such as inks and glues – in large-strain deformation of metals. Unlike other well-known phenomena such as stress corrosion cracking and liquid metal embrittlement, the effect is not catastrophic and is largely material independent. High-speed in situ imaging shows that the media influence the flow by effecting a local ductile-to-brittle transition – from unsteady, large-amplitude, plastic folding, to repeated fracture and segmentation – with large decrease in deformation forces. The benign nature of the media offers opportunities for enhancing performance of metal cutting and deformation processes. 相似文献
Background: Transgender people (those who feel incongruence between the gender they were assigned at birth and their gender identity) engage in lower levels of physical activity compared to cisgender (non-transgender) people. Several factors have been shown to affect physical activity engagement in the cisgender population; however, the physical activity experiences of young transgender adults have not been explored. It is therefore the aim of the current study to understand what factors are associated with physical activity and sport engagement in young transgender adults who are medically transitioning.
Method: Semi-structured interviews were conducted with 14 young transgender adults (18–36 years) who had initiated their medical transition at a transgender health service in the United Kingdom. The data were analyzed using thematic analysis.
Results: Two main themes were identified: (1) barriers and (2) facilitators to physical activity and sport. Overall, the young transgender adults were insufficiently active due to inadequate changing facilities, body dissatisfaction, fears surrounding “passing” and not being accepted by others. At the same time, participants were motivated to engage in physical activity to increase their body satisfaction and gender congruence. However, participants felt there was a lack of safe and comfortable spaces to engage in physical activity and sport.
Conclusion: Young transgender adults who are medically transitioning experience several barriers to physical activity and sport, despite being motivated to be physically active. Initiatives to facilitate young transgender adults' ability to put their motivations into practice (i.e. to be more physically active) are needed. 相似文献
This paper is predominantly a clinical presentation that describes the transmigration of one patient's transference to another, with the analyst functioning as a sort of transponder. It involves an apparently accidental episode in which there was an unconscious intersection between two patients. The author's aim is to show how transference from one case may affect transference in another, a phenomenon the author calls transference before transference. The author believes that this idea may serve as a tool for understanding the unconscious work that takes place in the clinical situation. In a clinical example, the analyst finds himself caught up in an enactment involving two patients in which he becomes the medium of what happens in session. 相似文献
Current social work practice in the UK dictates that when children move from foster care into adoption, the transition takes place within 7 and 14 days, and usually there is no contact between the child and their former carer for several months after the move, if at all. Very little attention or research has been aimed at understanding the rationale for these procedures, or their impact on the children. Joining forces with social work colleagues in a Looked After Children’s team, two child psychotherapists carried out a piece of qualitative research to look at these moves in more detail, and try to tease out how and why these key decisions are made. Analysing data from interviews with foster carers, adopters and social workers, the researchers found that the emotional experience of the child, particularly their experience of losing their foster carer, loses centre stage in people’s minds during this transition, leading to what is described as a ‘blind spot’ across the network. A significant reason for this emerged, in that the children tended to be very compliant both during and after the move and lacking in any obvious distress at losing their former carers, despite having previously been described as passionately attached to them. The research showed that adults across the network, all struggling with intense anxieties of their own, tended to interpret this as evidence that the children were ‘fine’ rather than questioning what might be going on at a deeper level. These research findings are explored in the light of a knowledge base accumulated from a working understanding of attachment and loss in early childhood, and of the psychoanalytical phenomena of individual and organisational defences against loss. Implications for future practice are suggested. 相似文献
Life transitions can induce distress for emerging adults. This study compared a model of the attachment, social support, and well‐being of emerging adults in transition with a model of those not in transition (N = 378). The transition sample reported less life satisfaction and environmental mastery and higher attachment avoidance than the nontransition sample. The transition sample showed weaker mediating effects of social support, suggesting that attachment accounted for additional unique variance for this group. Counseling implications are provided. 相似文献
The magnetic properties of a Mn-doped armchair ZnO nanotube have been studied using Monte Carlo simulation. The variation of zero-field-cooled and field-cooled magnetisation with reduced temperatures for different values of the dilution x (where x is the Mn concentration: Zn1?xMnxO) are given. The freezing temperatures and magnetisation vs. crystal field are calculated for different dilutions x. Finally, the hysteresis loops for different dilutions and temperatures are given for a fixed reduced temperature and crystal field. Superparamagnetic behaviour is observed for small values of x and low temperatures. 相似文献