scholarly journals Adaptive process in motor learning: the role of variability

Author(s):  
Go Tani

O objetivo desta apresentação é sintetizar alguns estudos experimentais realizados recentemente no Laboratório de Comportamento Motor (LACOM) para testar os principais pressupostos de um modelo teórico que trata da aquisição de habilidades motoras como um processo adaptativo. Segundo esse modelo teórico, a aquisição de habilidades motoras é um processo cíclico e dinâmico de estabilidade-instabilidadeestabilidade que resulta em crescente complexidade. Assim, considera-se não apenas a estabilização, mas também a adaptação como fases constituintes do mesmo processo. O problema central é considerar como consistência e variabilidade são conciliados numa mesma estrutura. Propõe-se, então, que através da prática é formado um programa de ação organizado hierarquicamente em dois níveis: a macro-estrutura que é expressa nos aspectos invariantes da habilidade motora estando assim relacionada à consistência, e a micro-estrutura expressa nos aspectos variantes da habilidade motora estando relacionada, portando, à desordem e à variabilidade. Dois estudos experimentais são descritos, um envolvendo uma tarefa de controle de força de preensão manual, e outro com uma tarefa de posicionamento linear com reversão. Os resultados foram, de uma forma geral, favoráveis às predições do modelo teórico proposto, porém, para que ele seja aperfeiçoado, é necessária a realização de novos estudos

2020 ◽  
Vol 16 ◽  
Author(s):  
Andrey Krylatov ◽  
Leonid Maslov ◽  
Sergey Y. Tsibulnikov ◽  
Nikita Voronkov ◽  
Alla Boshchenko ◽  
...  

: There is considerable evidence in the heart that autophagy in cardiomyocytes is activated by hypoxia/reoxygenation (H/R) or in hearts by ischemia/reperfusion (I/R). Depending upon the experimental model and duration of ischemia, increases in autophagy in this setting maybe beneficial (cardioprotective) or deleterious (exacerbate I/R injury). Aside from the conundrum as to whether or not autophagy is an adaptive process, it is clearly regulated by a number of diverse molecules including reactive oxygen species (ROS), various kinases, hydrogen sulfide (H2S) and nitric oxide (NO). The purpose this review is to address briefly the controversy regarding the role of autophagy in this setting and to examine a variety of disparate molecules that are involved in its regulation.


2018 ◽  
Vol 62 ◽  
pp. 211-220 ◽  
Author(s):  
Sandra J.M. van Cappellen – van Maldegem ◽  
Femke van Abswoude ◽  
Hilde Krajenbrink ◽  
Bert Steenbergen

Author(s):  
Dongwon Kim ◽  
B. J. Johnson ◽  
R. B. Gillespie ◽  
R. D. Seidler
Keyword(s):  

1978 ◽  
Vol 235 (4) ◽  
pp. F265-F277 ◽  
Author(s):  
R. L. Tannen

The pathways responsible for an the mechanisms underlying the adaptive increase in ammonia production in response to acidosis are considered. It seems unlikely that the cytosolic pathways (glutamine synthetase, glutaminase II, phosphate-independent glutaminase, and gamma-glutamyl transferase) are of primary importance in the adaptive process, but the role of the purine nucleotide cycle has not been resolved. The intramitochondrially located phosphate-dependent glutaminase pathway is generally believed to be of primary importance. Adaptation involved either enhanced glutamine entry into the mitrochondria and/or activation of phosphate-dependent glutaminase, but the relative importance of each has not been resolved definitively. The overall adaptive response is probably modulated by factors regulating alpha-ketoglutarate metabolism to phosphoenolpyruvate, and possibly also by metabolism of TCA cycle intermediates. It seems unlikely that a decrease in systemic pH is the direct effector for the acidosis-induced increase in ammonia formation; however, the resulting decrease in urine pH may play a critical role. Other potential messengers, including potassium, glucocorticoids, mineralocorticoids, cyclic AMP, and calcium probably do not serve a primary function, but the importance of other circulating factor(s) is unclear.


2012 ◽  
Vol 22 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Ryan J. Rabett ◽  
Philip J. Piper

For many decades Palaeolithic research viewed the development of early modern human behaviour as largely one of progress down a path towards the ‘modernity’ of the present. The European Palaeolithic sequence — the most extensively studied — was for a long time the yard-stick against which records from other regions were judged. Recent work undertaken in Africa and increasingly Asia, however, now suggests that the European evidence may tell a story that is more parochial and less universal than previously thought. While tracking developments at the large scale (the grand narrative) remains important, there is growing appreciation that to achieve a comprehensive understanding of human behavioural evolution requires an archaeologically regional perspective to balance this.One of the apparent markers of human modernity that has been sought in the global Palaeolithic record, prompted by finds in the European sequence, is innovation in bonebased technologies. As one step in the process of re-evaluating and contextualizing such innovations, in this article we explore the role of prehistoric bone technologies within the Southeast Asian sequence, where they have at least comparable antiquity to Europe and other parts of Asia. We observe a shift in the technological usage of bone — from a minor component to a medium of choice — during the second half of the Last Termination and into the Holocene. We suggest that this is consistent with it becoming a focus of the kinds of inventive behaviour demanded of foraging communities as they adapted to the far-reaching environmental and demographic changes that were reshaping this region at that time. This record represents one small element of a much wider, much longerterm adaptive process, which we would argue is not confined to the earliest instances of a particular technology or behaviour, but which forms part of an on-going story of our behavioural evolution.


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