No abstract available.
Periodicity* ; Skin*

No abstract available.
Biological Clocks* ; Periodicity*

The author had been experienced one case of ophthalmic migraine recently and was reviewed the liturature. Variability of symptoms and periodicity are characteristic feature of the migraine Syndroms. In this case, periodic scintillating scotoma, which developed abruptly, was revealed congruous in the right homonymous fields, lasting about 30 minutes. Scintillating scotoma refers to the migraneous scotoma with the shimmering border. This illuminated dancing border takes the form of "fortification figures". The Author was concerned particularly about the variable symptoms and pathogenesis of aphthalmic migraine.
Dancing ; Migraine Disorders* ; Periodicity ; Scotoma

The R-R interval analyzer was developed to measure the autonomic nervous system function using microcomputer. The system based on 8 bit microcomputer including bandpass filter, R-wave detector and clock generator in order to obtain the mean value, standard deviation, total time, CV value, maximum value and minimum value in the specific view point of R-R interval variation. The pattern of R-R interval change after resting, voluntary standing and deep breathing can be analyzed in normal subjects and diabetics with autonomic nervous dysfunction. The amplitude of the R-R interval variation showed sensitive pattern for normal subjects at resting, standing and deep breathing. On the contrary, the periodicities of amplitude for abnormal subjects with autonomic nervous dysfunction showed dull pattern. It was suggested that R-R interval analyzer is a good detection method for dysfunction of autonomic nervous system.
Autonomic Nervous System ; Methods ; Microcomputers* ; Periodicity ; Respiration

PURPOSE: To develop a fast and robust seizure anticipation program and test its usefulness in seizure prediction and localization of epileptic focus. METHODS: The video-EEG monitoring was performed in 20 epilepsy patients. The NPISI (Nonlinear Periodicity of Inter-Spike Intervals) of each channel and averaged NPISI of all channels were calculated in pre-ictal and ictal periods of 21 epileptic seizures. Seizure prediction times of NPISI in each channel and all channels were determined. RESULTS: There were eight mesial TLE, twelve neocortical epilepsies. The significantly reduced NPISI prior to seizure onset was observed in 20 seizures (95.2%) by NPISI of single EEG channel and in 14 seizures (66.7%) by the averaged NPISI of all channels. Time of seizure anticipation was 17.3+/-7.3 min by single channel NPISI and 14.0+/-6.0 min by all channel NPISI prior to the seizure onset. The earliest NPISI reduction was detected at electrodes concordant to the seizure focus in 6/20 (30.0%) seizures, electrodes adjacent to the focus in 5/20 (25.5%), mirror electrodes contralateral to the seizure focus in 4/20 (20.0%), and irrelevant electrodes to the focus in 5/20 (25.5%). CONCLUSIONS: This study demonstrated that the reduction of NPISI could predict epileptic seizures long before clinical seizure onset. Although the earliest NPISI reduction was observed at or near to epileptic focus in most cases, pre-ictal changes of NPISI occurred far beyond the epileptic focus. These findings suggest that pre-ictal NPISI reduction may reflect a widespread facilitation of brain before the seizure onset.
Brain ; Electrodes ; Electroencephalography ; Epilepsy* ; Humans ; Periodicity* ; Seizures

The periodicity of the microfilariae of Brugia malayi was studied in 9 human carriers from Shin-san Ri, Seong-san Myon, Cheju Island. The periodicity pattern was markedly nocturnal and the peaks were observed between 21:30 p.m. and 5:30 a.m. The average peak count was 1:30 a.m. and the percentage of peak count at this time was 95.3. The ratio of minimum of the average peak count percentage to the maximum was 8.3. The periodicity pattern of B.malayi in Cheju Island was compared with that in Inland and no differences were found between two forms. From the above observations, it was concluded that the periodicity of B. malayi in Korea is markedly nocturnal and closely resembles that in the strain of Penang, Malaya.
parasitology-helminth-nematoda-Brugia malayi ; periodicity ; microfilaria

The purpose of this article is to introduce the measurements of phase coupling between spikes and rhythmic oscillations of local field potentials (LFPs). Multi-channel in vivo recording techniques allow us to record ensemble neuronal activity and LFPs simultaneously from the same sites in the brain. Neuronal activity is generally characterized by temporal spike sequences, while LFPs contain oscillatory rhythms in different frequency ranges. Phase coupling analysis can reveal the temporal relationships between neuronal firing and LFP rhythms. As the first step, the instantaneous phase of LFP rhythms can be calculated using Hilbert transform, and then for each time-stamped spike occurred during an oscillatory epoch, we marked instantaneous phase of the LFP at that time stamp. Finally, the phase relationships between the neuronal firing and LFP rhythms were determined by examining the distribution of the firing phase. Phase-locked spikes are revealed by the non-random distribution of spike phase. Theta phase precession is a unique phase relationship between neuronal firing and LFPs, which is one of the basic features of hippocampal place cells. Place cells show rhythmic burst firing following theta oscillation within a place field. And phase precession refers to that rhythmic burst firing shifted in a systematic way during traversal of the field, moving progressively forward on each theta cycle. This relation between phase and position can be described by a linear model, and phase precession is commonly quantified with a circular-linear coefficient. Phase coupling analysis helps us to better understand the temporal information coding between neuronal firing and LFPs.
Action Potentials ; Hippocampus ; physiology ; Neurons ; physiology ; Periodicity

In the forensic practice, the reliability of diatom test as a supportive measure to diagnose drowning is still disputed, from trustworthy to worthless. Some of the reason for the controversy is low sensitivity of the test, possibility of postmortem contamination and the detection of diatom in the tissues of non-drowned body. However, there is a variation of the diatom flora by season and by locale and it is strongly correlated with the frequency of positive diatom test outcomes. Therefore, if there is a profile of the diatom flora at a site, it can be compared with the diatom genera found in tissues of the immersed bodies, and also the test result can be predicted or verified. On each season, at three aquatic locations where drowning victims are often found, the author collected water samples and examined the plankton species of the samples, including dominant species and total number of plankton by site and by season. The examination result showed 16 species of diatoms, 20 species of green algae, 6 species of cyanobacteria, and 6 species of other algae. There is an enormous difference of population of algae by site(39 cells ~ 37,180 cells), but conspicuous periodicity of types and numbers of algae is not noted by season and by depth.
Chlorophyta ; Cyanobacteria ; Diatoms ; Drowning ; Periodicity ; Plankton ; Seasons ; Water

BACKGROUND: The onset of acute myocardial infarctin varies in a circadian and seasonal pattern, with a morning and winter peak. The purpose of this study was to determine whether the frequency of onset of acute myocardial infarction varies circadianly and seasonally in Korean patients. METHODS: We analyzed the time of onset of chest pain in 409 patients with myocardial infarction admitted to our hospital over the past 30 years according to a 24-hour and 12 month period. RESULTS: There notel marked circadian variations in the frequency of onset, with the primary peak from 6 a.m. to noon and the secondary peak from 6 p.m. to midnight (p<0.001). Circadian bimodal rhythmicity of myocardial infarction was demonstrated in this study. By the sex analysis, circadian variations of frequency of acute myocardial infarction were also similar to those of total patients. Interestingly, circadian variations were slightly different in the patients below 50 years of age, showing the highest frequency of onset in the time between 6 pm and midnight (p<0.062). And we also analyzed the frequency of onset of AMI by seasons. The notel a peak incidence in autumn, and followed by winter and spring. But we didn't find any statistical significance (p<0.059). However, comparing summer to other seasons, summer showed the lowest incidence of myocardial infarction with statistical significance (p<0.001). CONCLUSIONS: Ever though the study population in small, this study showed that the frequency of acute myocardial infarction had a circadian and a seasonal variation in Korean patients.
Chest Pain ; Humans ; Incidence ; Myocardial Infarction* ; Periodicity ; Seasons*

PURPOSE: To evaluate the feasibility of functional MR imaging (fMRI) with a 1.0 T scanner, fMRI of normal cerebral motor cortex at 1.0 T was compared with that at 1.5 T. MATERIALS AND METHODS: FMRI of bilateral cerebral motor cortices (left, seven; right, six) was performed in seven healthy male volunteers aged 26-34 (mean 29) years, with BOLD contrast at both 1.0 T and 1.5 T units (Siemens MR scannners). Using both these systems, two-dimensional (2D) FLASH images were obtained with TR/TE of 90/56, flip angle of 40degrees, matrix size 128*128, slice thickness of 5 mm, and FOV 23 cm. A sequence consisting of five-image-off phase (rest phase) followed by five-image-on phase (activation with finger movement) was repeated four times without pause at a single plane. The same study was performed for the contralateral motor cortex in each volunteer. Using the z-test, activation images were obtained for the signal difference between on- and off-phases (p < 0.05) and were then superimposed on 2D FLASH anatomic images at the same plane. Percentage changes of signal intensities (PCSIs) and numbers of activated pixels were compared, using the non-parametric t-test, and periodicity of signal changes was compared, using the Mantel-Haenszel Chi-square test. RESULTS: Mean PCSIs at 1.5 T and 1.0 T in the left motor cortex were 3.13 +/-1.20% and 1.43 +/- 0.56%, respectively (p = 0.009), and in the right, 1.78 +/- 0.95% and 1.34 +/- 0.28%, respectively (p = 0.32). The mean number of activated pixels at 1.5 T and 1.0 T in the left cortex was 21.14 +/- 10.67 and 19.86 +/- 11.36, respectively (p = 0.83), and in the right, 22.5 +/- 6.47 and 16.8 +/- 8.47, respectively (p= 0.22). At 1.5 T, periodicity of signal changes was seen in the left cortex in six of seven volunteers, and in the right cortex, in four of six. At 1.0T, all showed periodicity (left : p = 0.32 ; right : p = 0.14). CONCLUSION: PCSIs in the dominant hemispheres were significantly higher at 1.5 T, but no other indicators showed significant differences between 1.0 T and 1.5 T. Acceptable fMRI can therefore be carried out with a 1.0 T field strength scanner.
Fingers ; Humans ; Magnetic Resonance Imaging* ; Male ; Motor Cortex* ; Periodicity ; Volunteers