The major aim of the present study was to investigate whether painful stimuli have a differential effect on the Readiness Potential (RP) in terms of the early and late components. We hypothesized ...that painful stimuli would modulate the cortical movement preparatory activity and the components to a different extent when compared to non-painful stimuli.
The readiness potential (RP), which is a slow negative electrical brain potential that occurs before voluntary movement, can be interpreted as a measure of intrinsic brain activity originating from self-regulating mechanisms. Early and late components of the RP may indicate clinical-neurophysiological features such as motivation, preparation, intention, and initiation of voluntary movements. 15 healty volunteers were enrolled in this study. We conducted electrical stimulation trials in two randomized blocks termed as “no-pain condition” and “pain condition“. Our results demonstrated that painful stimuli were preceded by an enhanced RP at the Cz channel (p<0.05). The mean amplitude of the RP at the early phase was significantly higher for the painful stimuli when compared to the non-painful stimuli (p<0.05). Our results indicate that electrical painful stimuli, which can be considered as an unpleasant and stressful condition, modulate the motor preparation at sensory motor regions to a different extent when compared to non-painful electrical stimuli. Since early component of the RP represents cortical activation due to anticipation of the stimuli and the allocation of attentional resources, our results suggest that painful stimuli may affect the motor preparation processes and the prediction of the movement at the cortical level.
A model of viscosity for liquid metals Morioka, S.; Xiufang, Bian; Minhua, Sun
International journal of materials research,
01/2022, Letnik:
93, Številka:
4
Journal Article
Recenzirano
We present a model to describe the viscosity of liquid metals with known physical properties. The model involves two adjustable parameters to the experimental data of the viscosity, but can be ...related to an effective atomic diameter and the coordination number of nearest-neighbor atoms in the liquid metals. The model is applied to eleven cases of mono-atomic liquid metals. The model is capable of describing the overall experimental data of the viscosity in a wide range of temperature, predicting the mean free paths of an atom in accord to the experimental interatomic distances in the liquid metals. An extension of this model to multi-component liquid metals is also suggested.
The morphological development, including the fins, body proportions and pigmentation, of laboratory-reared larval and juvenile Pangasianodon hypophthalmus was described and their behavioral features ...were observed under rearing conditions. Body lengths (BL) of larvae and juveniles were 3.0+-0.2 (mean+-SD) mm just after hatching, and 12.9+-1.1 mm on day 13, reaching 23.4+-1.8 mm on day 25 after hatching. Aggregate fin ray numbers (for caudal fin, principal soft ray number) attained their full complements in specimens larger than 12.8 mm BL. Notochord flexion began in yolksac larvae on day 0 (10.5 h after hatching), with teeth buds and barbels appearing with jaw formation in yolksac flexion larvae on day 1. Melanophores on the body increased with growth, with a broad vertical band forming on the lateral line and an oblique band extending from above the pectoral fin base towards the forepart of the anal fin during the postflexion larval and juvenile stages. Body proportions became relatively constant in juveniles, except for maxillary barbel length (MBL), which continued to decrease. Yolksac flexion larvae started feeding on day 2 with the onset of intense cannibalism. Yolks were completely absorbed by day 3, and cannibalism ended by day 6. Subsequently, fish displayed a schooling behavior with growth, preferring relatively dark areas during the juvenile stage.
