• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.4
• /
• pp.432-437
• /
• 1999

Age and growth of the marbled rockfish, Sebastiscus marmoratus were studied based on 818 specimens caught from the coastal waters of Cheju Island from July 1992 to July 1993 and from June 1994 to July 1995. According to the monthly changes of marginal increment in each annual ring groups, the ring of otolith was formed in both female and male in February. Relationship between the total body length (TL) and the radius of otolith (R) was estimated, Growth of females was rather slower than that of male in total length; TL=-0.526+4.818R(r=0.847) for female, and TL=-1.895+ 5.239R (r=0.881) for male. The growth curve fits well with Bertalanffy equation: $L_{t}=21.484(1-e^{-0.424(t+0.334)})$ for female and $L_{t}=23.698(1-e^{-0.441(t+0.0589)})$ for male, Growth in weight as follows: $W_t=163.42(1-e^{-0.424(t+0.334)})^3$ for female and $W_t=210.14(1-e^{-0.441(t+0.0589)})^3$ for male.

• Sleep Medicine and Psychophysiology
• /
• v.26 no.1
• /
• pp.16-22
• /
• 2019

Objectives: The objective of this study was to investigate the correlation between insufficient sleep and visuospatial memory in adolescents using a computerized neurocognitive function test. Methods: A total of 103 high school students (26 males and 77 females; mean age $17.11{\pm}8.50years$) without a serious psychiatric problem was recruited. All subjects were requested to complete a self-report questionnaire about weekday total sleep time and weekend total sleep time. The epworth sleepiness scale (ESS) and the beck depression inventory (BDI) were administered to measure daytime sleepiness and symptoms of depression. Seven subsets of the Cambridge Neuropsychological test automated battery were examined to assess visuospatial memory. Results: After controlling for age, sex, ESS, and BDI, longer weekend total sleep time was correlated with poor performance on delayed matching to sample (r = -0.312, p = 0.002) and immediate recall on pattern recognition memory (r = -0.225, p = 0.025). Increased weekend catch-up sleep time was correlated with poor performance of delayed matching to sample (r = -0.236, p = 0.018), immediate recall on pattern recognition memory (r = -0.220, p = 0.029), and delayed recall on pattern recognition memory (r = -0.211, p = 0.036) after controlling for age, sex, ESS, and BDI. Conclusion: This study showed that increased weekend catch-up sleep time reflecting insufficient weekday sleep were associated with poor performance in delayed recall tasks of visual memory. This finding suggests that insufficient sleep during adolescence might produce a decline of visuospatial memory.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.49 no.2
• /
• pp.177-182
• /
• 2023

Since facial skin pigmentation is one of the visual characteristics of skin aging, it is important to evaluate skin pigmentation in the cosmetics and aesthetic fields. Several groups have investigated and developed the image analysis methods for skin pigmentation and some of the groups reported the age-related changes of the number and size of facial pigmented spots. However, they didn't show the changes of the number and size of pigment spots by defined size, and there is no report for Korean female regarding pigmentation. A total of 194 Korean females aged 20 ~ 79 (48.97 ± 17.11 years) were analyzed for the number, size, and intensity of pigmented spots using various filters such as large high-pass filter and median filter in their digital facial images. There were significant correlations between age and total pigmented spot number (No.), size, and intensity (I) (pearson's correlation coefficient r = 0.688, r = 0.645, r = -0.563), and significant correlations were also observed between the number and intensity of pigmented spots of different sizes. According to the ANOVA results, there were significant differences in the percentage of spot size of 2 ~ 4 mm² and > 20 mm² between 20's and 70's. In other words, with aging, pigmentation increases in the facial skin, and the large increase in pigmentation is particularly noticeable in Korean women.

• Journal of Oral Medicine and Pain
• /
• v.14 no.1
• /
• pp.43-55
• /
• 1989

The need of age estimation for identification was increased by complexity of society, and the tooth was used widely for age estimation because of less individual deviation than the other organ. The age estimation using the tooth had several methods. Recently, the one using the racemization of aminoacid in the tooth was admitted more accurate than the other methods, especially in old age. But, this study was not tried in our country, and I would report the result of experiment about age estimation using racemization of dentine. I selected 40-Whole dentine sample from extracted teeth, those were reserved in natural dried condition for 2 weeks~ 1year and calculated the estimation of age from the ratio of D-aminoacid and L-aminoacid (D/L ratio) using gaschromatography and the results were below. 1. The aminoacids showed apparent K/L ratio in dentine were aspartic acid, serine. 2. The aspartic acid showed the highest racemic rate and its rate was 0.0012$\pm$0.0003/yr. 3. The relation between the actual age and K/L ratio was very positive correlation(r+0.954) in the estimation of age using aspartic acid. 4. The deviation between the estimated age using D/L ratio of aspartic acid and actual age was $\pm$3.32.

• The Korean Journal of Nuclear Medicine
• /
• v.33 no.3
• /
• pp.247-261
• /
• 1999

Purpose: The aim of this study was to evaluate the normal values of regional cerebral blood flow (rCBF) and cerebrovascular reserve (CVR) in normal children to aged volunteers using Tc-99m HMPAO, Materials and Methods: Thirty four right-handed normal volunteers (20 males, 14 females, mean age $40.3{\pm}24.9$ years, range 4 to 82 years) were underwent rost/acetazolamide (ACZ) brain SPECT using Tc-99m HMPAO and the sequential injection and subtraction method. rCBF was estimated on the basis of a semiquantitative approach by means of right/left ratio, region/cerebellum and region to whole brain ratios in (rental, parietal, temporal, and occipital lobes, basal ganglia, thalami, and cerebellum. CVR was measured by means of % perfusion increase calculated as % mean count change compared to rest rCBF in each regions. Results: Mean values of right to left ratios range from 1.004 to 1.018, rCBF was highest in cerebellum and lowest in basal ganglia and thalami. Frontal and temporal rCBF decreased while occipital and thalamic rCBF increased according to age. No sexual difference of rCBF was noted. Mean CVR was $29.9{\pm}12.9%$. Mean CVR significantly increased to late teens, and declined thereafter. After 6th decade, CVR in both frontal lobes, left parietal lobe and right basal ganglia decreased significantly with advancing age. There was no sexual difference of CVR. Conclusion: Quantitative assessment of CVR was possible by ACZ Tc-99m HMPAO brain SPECT. It revealed that rCBF and CVR changed according to age in normal Korean volunteers. There was no sexual difference.

• Asian-Australasian Journal of Animal Sciences
• /
• v.7 no.2
• /
• pp.201-205
• /
• 1994

Thirty buffalo calves were randomly categorized into three groups on the basis of age, i.e. birth to 6 months; 6 to 12 months and 12-24 months. Blood samples were collected to monitor certain vital metabolites in relation to age and prediction of performance in growing buffalo calves. Amongst the various blood parameters estimated the serum glucose, cholesterol and gamma globulins have shown highly significant correlations with age and live weight-gain of the animal as well. However, the multiple regression analysis clearly indicated the influence of age and live body weight on blood metabolites in buffalo calves.

• Communications of the Korean Mathematical Society
• /
• v.18 no.1
• /
• pp.133-149
• /
• 2003

Local stability of steady states of an epidemic model is considered. An age structured S-I-R epidemic model with separable inter-cohort force of infection with external force is considered. Stability result for the nontrivial steady states is obtained.

• Journal of Yeungnam Medical Science
• /
• v.5 no.1
• /
• pp.93-100
• /
• 1988

In clinical practice, creatinine clearance(Ccr) remains the most commonly used laboratory assessment of glomerular function despite methodological and technical problems of urine collection. Schwartz et al. in 1976, reported that an accurate estimate of glomerular filtration rate(GFR) could be obtained from the simple determinations of plasma creatinine(Pcr) and body length(L) : GFR($m{\ell}/min/1.73m^2$=k L(cm)/Pcr(mg/$100m{\ell}$), (k=constant). The subject of this study were ill children admitted to our pediatric department from July, 1985 to June, 1987 and they were divided into three groups; group I, from 1 to 5 years old, group II, from 6 to 10 years old, group III. from 11 to 15 years old. The results were as following ; 1) Measured creatinine clearance($Ccr_M$, $m{\ell}/min/1.73m^2$) were $109.73{\pm}9.97$ in group I, $108.26{\pm}9.02$ in group II, $96.20{\pm}4.72$ in group III and $105.48{\pm}5.23$ in all age group. 2) Measured k($k_M$) obtained from $Ccr_M=k$ Ht/Pcr were $0.49{\pm}0.03$ in group I, $0.48{\pm}0.02$ in group II, $0.43{\pm}0.02$ in group III, and $0.47{\pm}0.02$ in all age group.(Ht ; height) 3) Linear equations and correlation coefficients between Ht/Pcr(x) and Ccr(y) were y=0.822x-65.63(r=0.99) in group I, y=0.61x-23.46(r=0.72) in group II, y=0.18x+54.44(r=0.54) in group III and y=0.58x-22.13(r=0.81) in all age group. 4) $Ccr_E$ was again estiamted from linear equations between Ht/Pcr and $Ccr_M$ and $k_E$ was calculated with Ht/Pcr and $Ccr_E$ were $0.48{\pm}0.01$ in group I, $0.49{\pm}0.01$in group II, $0.43{\pm}0.01$ in group III and $0.47{\pm}0.00$ in all age group. 5) Consistant values of $k_E$ and $k_M$ were highly significant as 95~97.5% in group I and II, 90~95% in group III and 97.5~99% in all age group. In summary, we could estimate GFR with height, plasma creatinine and measured k($k_M$) according to the age in easy and rapid way.

• The Korean Journal of Malacology
• /
• v.30 no.1
• /
• pp.33-40
• /
• 2014

The age and growth of Gomphina (Macridiscus) veneriformis sampled from February 2006 to January 2007 on the Wonsan coast of East Sea were determined from 3,899 shell. Age of Gomphina (Macridiscus) veneriformis was estimated from the ring on the surface of shell. The relationship between shell length (SL) and shell height (SH) was expressed by the following equation : SH = 0.7405 SL + 0.2227 ($R^2$ = 0.9671), and shell length (SL) and shell width (SW) was highly correlated by the equation : SW = 0.3657 SL + 0.4253 ($R^2$ = 0.922). The relationship between shell length (SL) and total weight (TW) was also expressed by the following equation : $TW=0.4274{\times}10^{-3}{\times}SL^{2.7876}$ ($R^2$ = 0.9591). The main spawning periods was estimated August through fatness index analysis. Based on the monthly variations in the marginal index (MI) of the shell, it is assumed that the ring of this species was formed once a year during the period of July. Growth curves for shell length (SL) and total weight (TW) fitted to the von Bertalanffy's equation were expressed as follows : $$SL_t=70.80(1-e^{-0.217(t+0.367)})$$ $$TW_t=(1-e^{-0.217(t+0.367)})^{2.7876}$$

• The Korean Journal of Nuclear Medicine
• /
• v.28 no.1
• /
• pp.52-61
• /
• 1994

Background : The demand for refinement in noninvasive and quantitative assessment of left ventricular (LV) function is increasing. Purpose : To assess normal values of left ventricular functional parameters during both systole and diastole by scintigraphic method using computerized triple-head gamma camera and to evaluate correlations between these parameters. Methods : ECG gated blood pool scan with $^{99m}Tc$-Human serum albumin was performed in 94 normal Korean subjects. Ejection fraction (EF), systolic parameters [peak emptying rate (PER), average emptying rate (AER), time to peak emptying rate (TPER)], and diastolic parameters [peak filling rate (PFR), average filling rate (AFR), time to peak filling rate (TPFR)] were obtained by analysis of LV time-activity curve, the correlation of these parameters to the age and sex, and the correlation between these parameters were evaluated. Results : 1) Mean value of ejection fraction in study subjects was $59.6{\pm}5.25%$ and showed no significant correlation to age (r=-0.08) and sex but showed most pronounced correlation to PFR (r=0.46, p<0.001), PER (r=0.41, p<0.001), AFR (r=0.34, p<0.001) and AER (r=0.28, p<0.01). 2) Mean values of systolic parameters were as follows: $PER=3.22{\pm}0.50$ end-diastolic volume/sec, $AER=2.22{\pm}0.45$ end-diastolic volume/sec, $TPER=103.5{\pm}29.30$ msec. They showed no significant correlation to age and sex. 3) Mean values of diastolic parameters were as follows: $PFR=2.71{\pm}0.51$ end-diastolic volume/sec, $AFR=1.83{\pm}0.44$ end-diastolic volume/sec, $TPFR=132.1{\pm}33.45$ msec. They showed strong correlation to age (r=0.70, -0.64, 0.37, p<0.001). Conclusions : Left ventricular functional parameters in normal Korean subjects were obtained reliably by computerized scintigraphic method and may be applied to the evaluation of cardiac function in diseased patients.