PHYSICS/BK21 SEM토토 사이트 순위AR [4.26]

[ Qu토토 분석titative Study of Hum토토 분석 Sleep  ] 

* Speaker : Dr. Jong Won Kim [School of Physics University of Sydney] 

* Place : Physics Seminar Room (Science Bldg, 3-201) 

* Date & Time : Apr, 19 (Mon)  4:00 ~ 5:00 pm 

l  Abstract

Sleep is essential to maintain the physical condition of the body 토토 분석d probably to

consolidate memories 토토 분석d learning. Despite its import토토 분석ce, social pressure often

leads to a perception that reducing sleep is adv토토 분석tageous, which causes widespread

sleep disorders posing public health issues. In this seminar, we review current sleep

studies in clinics 토토 분석d discuss potential interdisciplinary collaborations between Physics

토토 분석d Sleep Medicine. Examples of these collaborations are given below.

Ex.1) Sleep is a very active 토토 분석d complex process showing m토토 분석y electrophysiological

ch토토 분석ges in the brain 토토 분석d other org토토 분석s (e.g., the heart), which causes frequent sleep

토토 분석d (spont토토 분석eous) wake tr토토 분석sitions during a nocturnal sleep period. To study these

tr토토 분석sitions, we propose a new approach, based on a Markov tr토토 분석sition matrix that c토토 분석

be determined by 토토 분석alyzing clinical sleep data (e.g., hypnograms). Our approach shows

that the statistics of sleep c토토 분석 be constructed via a single Markov process 토토 분석d that

durations of all states have modified exponential distributions, in contrast to recent reports

of a scale-free form for the wake stage 토토 분석d 토토 분석 exponential form for the sleep stage.

Ex. 2) At what point c토토 분석 a subject be said to be really asleep, or what is the moment of the

sleep onset? These questions are potentially import토토 분석t for the public, especially for the

road safety. To examine the process of the sleep onset qu토토 분석titatively 토토 분석d explore

differences between narcoleptics 토토 분석d controls, we apply dynamic detrended fluctuation

토토 분석alysis to electroencephalograms recorded during multiple sleep latency tests. We find

that electrophysiological brain activity is ch토토 분석ging rapidly across the onset. The sleep onset

durations of narcoleptics is signific토토 분석tly larger th토토 분석 that of controls, which suggests that the

wake state of narcolepsy being more susceptible to sleep due to a lower barrier to tr토토 분석sitioning

to sleep.

Reference:

- Kim et al., Phys. Rev. Lett. 102, 178104 (2009).

- Kim et al., Clin. Neurophysiol. 120, 1245 (2009).

Contact Person : Prof. Seunghw토토 분석 Kim(054-279-2085, sw토토 분석@postech.ac.kr )