• Title/Summary/Keyword: age effect

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Effects of Maternal Factors on Day-old Chick Body Weight and Its Relationship with Weight at Six Weeks of Age in a Commercial Broiler Line

  • Jahanian, Rahman;Goudarzi, Farshad
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.3
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    • pp.302-307
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    • 2010
  • The present study aimed to investigate the effects of maternal factors on body weight at hatching (day-old) and at six weeks of age in a commercial broiler line. A total of 6,765 records on body weight at day-old (BWTDO) and 115,421 records on body weight at six weeks of age (BWT6W), originated from a commercial broiler line during 14 generations, were used to estimate genetic parameters related to the effects of maternal traits on body weight of chicks immediately after hatch or six weeks thereafter. The data were analyzed using restricted maximum likelihood procedure (REML) and an animal model with DFREML software. Direct heritability ($h^{2}{_a}$), maternal heritability ($h^{2}{_m}$), and maternal environmental variance as the proportions of phenotypic variance ($c^{2}$) for body weight at day-old were estimated to be 0.050, 0.351, and 0.173, respectively. The respective estimated values for body weight at six weeks of age were 0.340, 0.022, and 0.030. The correlation coefficient between direct and maternal genetic effects for six-week-old body weight was found to be -0.335. Covariance components and genetic correlations were estimated using a bivariate analysis based on the best model determined by a univariate analysis. Between weights at hatching and at six week-old, the values of -0.07, 0.53 and 0.47 were found for the direct additive genetic variance, maternal additive genetic variance and permanent maternal environmental variance, respectively. The estimated correlation between direct additive genetic effect influencing weight at hatch and direct additive maternal effect affecting weight at six weeks of age was -0.21, whereas the correlation value of 0.15 was estimated between direct additive maternal effect influencing weight at hatch and direct additive genetic effect affecting weight at six-week-old. From the present findings, it can be concluded that the maternal additive genetic effect observed for weight at six weeks of age might be a factor transferred from genes influencing weight at hatch to weight at six-week-old.

Effects of the Chicken Sex-linked Dwarf Gene on Growth and Muscle Development

  • Chen, C.F.;Chen, Y.H.;Tixier-Boichard, M.;Cheng, P.Y.;Chang, C.S.;Tang, P.C.;Lee, Y.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.7
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    • pp.937-942
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    • 2009
  • The aim of this study was to analyze the effects on growth and muscle development during the growing period of the sex-linked dwarf gene in the background of a Taiwan Country chicken strain, L2, selected for egg production. Eight crossbred males, heterozygous for the DW*DW mutation, were each backcrossed to six females of the L2 strain to produce two genotypes of BC females, either normal (DW*N+/-) or dwarf (DW*DW/-). The experiment included 251 normal and 207 dwarf pullets. The effect of the dwarf gene on body weight and shank length was highly significant from 2 weeks of age. The reduction of body weight by the dwarf gene reached 34.8% and 37.4% as compared to normal sibs at 16 and 20 weeks of age, respectively. Parameters of the growth curve were estimated: the age at inflection (TI) was higher in normal pullets (66.9 days) than in dwarf pullets (61.2 days). A significant effect of the dwarf gene on single muscle fiber cross-section area was found from 12 weeks of age onwards, whereas the dwarf gene had no effect on the total number of muscle fibers. Comparing the effect of the dwarf gene on shank length at different ages revealed an earlier effect on skeleton growth, observed from 2 weeks of age, than on muscle development, which was affected from 8 to 12 weeks of age.

Effect of Korean and Western Attire of Eldery Women and Perceiver's Age on Impression Formation (노년여성의 한복 및 양장 착용과 관찰자의 연령이 인상형성에 미치는 영향)

  • 이명희
    • Journal of the Korean Society of Costume
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    • v.43
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    • pp.187-202
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    • 1999
  • The objectives of this study were to analyze the effect of dress(Korean traditional dress and suit) of elderly Women and situation on impression formation. The experimental design was $10\times{2}\times{2(dress}\times{perceiver's age}\times{situation)}$ factorial design by 3 independent variables. The stimuli of color photographs of female in her 60's model and the semantic differential scale were used. Six variables of impression formation were used: preference: elegance: potency: activity: feminine: and modernity. Samples were 400 women 200 were in their twenties and 200 in their forties and fifties. The data were analyzed by $\alpha$-reliability t-test ANOVA and duncan's multiple range test. The Korean traditional dress with the combination of Korean traditional color(light blue upper dress with dark red purple collar and string.dark blue skit) had the most positive effect on impression of elegance. Pink traditional dress and light blue traditional dress had a negative effect on impression of potency activity and modernity. Red purple suit had a positive effect on potency and modernity. The interaction between dress perceiver's age and stituation was significant for the impression of activity. Women in their 40's and 50's perceived the activity of red purple suit positively in the situation of alumnae meeting more than in the wedding ceremony. The perceived age of the stimulus person was different according to dresses. Traditional dresses was perceived older than suits were. Women in their 40's and 50's evaluated preferences of the dresses positively more than 20's did. This means that 40's and 50's feel similarity with the stimulus person more than 20's as the age of model was in their 60's The result supports the theory that similarity is basic factor in interpersonal attraction.

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The Relationship Between Safety Climate and Safety Performance, and the Moderating Effect of Age (안전분위기와 안전성과의 관계 및 연령의 조절효과)

  • Ahn, Kwan-Young
    • Journal of the Korean Society of Safety
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    • v.20 no.4 s.72
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    • pp.122-129
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    • 2005
  • With Zohar(1980)'s research on safety climate and industrial safety, occupational safety and health literatures begin to emphasize the influence of organizational context. Based on this research trend, this paper tried to review the relationship between individual/ organizational factors and occupational accidents. Based on the responses from 294 manufacturing workers, this paper reviewed the relationships among safety climates, safety performance, and age. The results of statistical analysis showed that all safety climate factors have affirmative effects on safety participation and safety attitudes negative effect on accident number, and job load affirmative effect on accident number. Job load and management commitment showed interactive effects on accident number with age.

Analysis of the Effects of Satisfaction with Job Participation on Psychological Adaptation of the Elderly

  • Jang, Chun-Ok
    • International Journal of Advanced Culture Technology
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    • v.10 no.2
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    • pp.213-219
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    • 2022
  • This study tried to find various alternatives to live the rest of life positively by examining whether satisfaction with work in old age has a positive effect on psychological adjustment in old age. Using the 15th (2020) data of the Korea Welfare Panel Study (KOWEPS), 117 men and 355 women were analyzed as a sample to verify the effect of job participation satisfaction among the elderly on psychological adjustment. The results of the regression analysis in this paper (F=11.680, p<.001) were analyzed to be significant. The results showed gender (β=-.192, p<.001), age (β=2.004, p<.001), and job participation satisfaction (β=-3.726, p<.001). Therefore, it was found to have an effect on psychological adaptation. In terms of gender, it was found that men had higher psychological adaptability than women, and that the lower the age, the higher the psychological adaptability. As a result, it was confirmed that the elderly's job participation is a simple economic part of the elderly, and the psychologically positive influence increased. The higher the job participation satisfaction, the higher the psychological adaptability.

Sildenafil Ameliorates Advanced Glycation End Products-Induced Mitochondrial Dysfunction in HT-22 Hippocampal Neuronal Cells

  • Sung, Soon Ki;Woo, Jae Suk;Kim, Young Ha;Son, Dong Wuk;Lee, Sang Weon;Song, Geun Sung
    • Journal of Korean Neurosurgical Society
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    • v.59 no.3
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    • pp.259-268
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    • 2016
  • Objective : Accumulation of advanced glycation end-products (AGE) and mitochondrial glycation is importantly implicated in the pathological changes of the brain associated with diabetic complications, Alzheimer disease, and aging. The present study was undertaken to determine whether sildenafil, a type 5 phosphodiesterase type (PDE-5) inhibitor, has beneficial effect on neuronal cells challenged with AGE-induced oxidative stress to preserve their mitochondrial functional integrity. Methods : HT-22 hippocampal neuronal cells were exposed to AGE and changes in the mitochondrial functional parameters were determined. Pretreatment of cells with sildenafil effectively ameliorated these AGE-induced deterioration of mitochondrial functional integrity. Results : AGE-treated cells lost their mitochondrial functional integrity which was estimated by their MTT reduction ability and intracellular ATP concentration. These cells exhibited stimulated generation of reactive oxygen species (ROS), disruption of mitochondrial membrane potential, induction of mitochondrial permeability transition, and release of the cytochrome C, activation of the caspase-3 accompanied by apoptosis. Western blot analyses and qRT-PCR demonstrated that sildenafil increased the expression level of the heme oxygenase-1 (HO-1). CoPP and bilirubin, an inducer of HO-1 and a metabolic product of HO-1, respectively, provided a similar protective effects. On the contrary, the HO-1 inhibitor ZnPP IX blocked the effect of sildenafil. Transfection with HO-1 siRNA significantly reduced the protective effect of sildenafil on the loss of MTT reduction ability and MPT induction in AGE-treated cells. Conclusion : Taken together, our results suggested that sildenafil provides beneficial effect to protect the HT-22 hippocampal neuronal cells against AGE-induced deterioration of mitochondrial integrity, and upregulation of HO-1 is involved in the underlying mechanism.

Incidence of Scarlet Fever in Children in Jeju Province, Korea, 2002-2016: An Age-period-cohort Analysis

  • Kim, Jinhee;Kim, Ji-Eun;Bae, Jong-Myon
    • Journal of Preventive Medicine and Public Health
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    • v.52 no.3
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    • pp.188-194
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    • 2019
  • Objectives: Outbreaks of scarlet fever in Mexico in 1999, Hong Kong and mainland China in 2011, and England in 2014-2016 have received global attention, and the number of notified cases in Korean children, including in Jeju Province, has also increased since 2010. To identify relevant hypotheses regarding this emerging outbreak, an age-period-cohort (APC) analysis of scarlet fever incidence was conducted among children in Jeju Province, Korea. Methods: This study analyzed data from the nationwide insurance claims database administered by the Korean National Health Insurance Service. The inclusion criteria were children aged ${\leq}14years$ residing in Jeju Province, Korea who received any form of healthcare for scarlet fever from 2002 to 2016. The age and year variables were categorized into 5 groups, respectively. After calculating the crude incidence rate (CIR) for age and calendar year groups, the intrinsic estimator (IE) method was applied to conduct the APC analysis. Results: In total, 2345 cases were identified from 2002 to 2016. Scarlet fever was most common in the 0-2 age group, and boys presented more cases than girls. Since the CIR decreased with age between 2002 and 2016, the age and period effect decreased in all observed years. The IE coefficients suggesting a cohort effect shifted from negative to positive in 2009. Conclusions: The results suggest that the recent outbreak of scarlet fever among children in Jeju Province might be explained through the cohort effect. As children born after 2009 showed a higher risk of scarlet fever, further descriptive epidemiological studies are needed.

The Effect of Dietary Quality on Quality of Life across Life Cycles in Korea - Using the Korea National Health and Nutrition Examination Survey 2013~2016 - (생애주기에 따른 식사의 질이 삶의 질에 미치는 영향 - 2013년~2016년 국민건강영양조사 자료이용 -)

  • Her, Eun-Sil;Seo, Bo-Young
    • The Korean Journal of Food And Nutrition
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    • v.34 no.1
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    • pp.96-106
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    • 2021
  • The purpose of this study was to compare the differences in the quality of dietary and life across age groups of Korean adults. According to life cycle, four age groups (20~29, 30~49, 50~64, ≥65) were created. Anthropometric indices showed significant differences according to age group (p<0.001). Energy intake significantly decreased according to age group as a result of decreased protein and fat intake (p<0.001). The intake levels of minerals, vitamins, and dietary fiber per 1,000 kcal were the lowest in the 20~29 age group (p<0.001). Whereas saturated fatty acids, MUFA, and PUFA intake levels were the highest for those in the 20~29 age group (p<0.001). The quality of dietary (DQI-I) increased with age group, but the quality of life (EQ-5D index) decreased (p<0.001). The quality of dietary showed 5.8% explanation power on the quality of life (p<0.001). Additionally, diet moderation was shown as having a negative effect, but the diversity and balance of diets had a positive effect on the quality of life. By age group, the relationship between quality of dietary and quality of life was the highest in ≥65 age group. These results suggest that practical dietary education is needed from the 20's to ensure the quality of healthy life for the elderly.

Population Aging and Wage Structure: An Empirical Study of Cohort Size Effect on Korean Male Worker since 1990 (인구 고령화와 임금구조: 1990년대 이후 한국 남성 근로자의 세대규모효과에 대한 실증분석)

  • Eom, Dong-Wook
    • Korea journal of population studies
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    • v.31 no.1
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    • pp.75-97
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    • 2008
  • Recently Korea is expected with the decrease of population in working ages and also population structure, especially age structure, has changed as aging goes faster. This study focuses on the relationship between age structure and wage structure to analyzes the cohort size effect on the change of age-earnings profile. Our empirical analysis based on Wright(1991)'s model takes weighted OLS regression using the male worker's data of Ministry of Labor 'Wage Structure Survey'($1990{\sim}2006$). In pooled data, we take the conclusion that the cohort size effect was found in high school and college graduate workers, but the effect is different between them. The labor market entry effect of high school graduate workers is negative(-) and his persistent effect is positive(+). On the other hand, the cohort size effect of college graduate workers have appeared the opposite directions in contrary with the existing results of Welch(1979) and Wright(1991). This results are seen as the possibility that college graduate worker has the benefit of wage level by his relative cohort size in spite of high unemployment of young graduate. It will be the sign of need that we should interest in the change of age structure with balancing the labor supply side approach and the demand side study which the previous studies was mainly tended to focus on.

The Effect of Parental Attachment on School Adjustment Perceived by School-Age Children: Self-Perceived Competence as a Mediating Variable (학령기 아동이 지각한 부모애착이 학교적응에 미치는 영향: 자기역량지각을 매개변인으로)

  • Hwang, Yun-Jung;Min, Ha-Yeoung
    • Journal of Families and Better Life
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    • v.30 no.2
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    • pp.65-73
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    • 2012
  • This study investigates influence of parental attachment on school adjustment using self-perceived competence as a mediating variable for perceived school age children. The subjects were 760 children who are 4, 5, and 6 grades in 4 elementary schools at Daegu. The collected data were analyzed by single and multiple regressions that used SPSS win 19.0 The results were as follows: (1) The parental Attachment perceived by school-age children was positively associated with on school adjustment. The parental attachment level of school-age children becomes higher as the perception of school adjustment increases. (2) The parental attachment perceived by school-age children was positively associated with self-perceived competence. That is, the parental attachment level of school-age children becomes higher as the self-perceived competence increase. (3) The effect of parental attachment in the school adjustment by children was reducing explanation when controlled for the self-perceived competence. The Parental attachment that influenced the school adjustment is partially mediated by self-perceived competence. The results of this research indicates that both the quality improvement of inter-relationship between children and parents for school adjustment of school-age children and training for strengthening self-perceived competence of school-age children are important.