• Title/Summary/Keyword: levels of evidence

Search Result 1,173, Processing Time 0.036 seconds

Influences of Histamine on Permeability across Blood-brain Barrier (혈액-뇌장벽 투과성에 대한 히스타민의 영향)

  • Kim, Kee-Jin;Shin, Dong-Hoon
    • The Korean Journal of Physiology
    • /
    • v.2 no.2
    • /
    • pp.33-43
    • /
    • 1968
  • Histamine, 0.5 mg as histamine base in 4 ml of normal saline solution, was injected into rabbits anesthetized with nembutal and the mean blood pressure was kept in the range of $52{\sim}80\;mmHg$ for over one hour by supplemental additions. Following the injection of the test substances, 300 mg of urea and 200 mg of antipyrine intravenously, serial blood samples were obtained from the femoral artery and the internal jugular vein at $0.5{\sim}3$ minutes interval. The decreasing patterns in the concentrations of arterial and venous blood plasma samples were compared with each other. The ratio of the concentration of brain tissue to that of the final arterial plasma was also studied. By these measures the degrees of penetration of the test substances in the brain in the control and in the histamine treated rabbits were observed. The concentrations of antipyrine and urea in the arterial blood plasma were decreasing exponentially with respect to the time elapsed. The venous concentrations were anticipated to increase initially and to cross the arterial concentration curve in the point of equlibrium between the plasma and the tissue. On the contrary to the expectation venous concentration also revealed the decreasing tendency similar to that of arterial plasma. The similarity between these two curves, arterial and venous, would be atributable to the fact that the cerebral blood flow rate was large enough and the rising phase in the venous concentration curve was instantly over before serial blood samples were taken. Inspite of some similarity in the decreasing tedency in both concentration curves there were appreciable discrepancies between the arterial and venous plasma which would reflect the situation far from the equlibria among several compartments in the brain. Changes in plasma potassium levels caused by the injection of histamine or bleeding were observed, too. Using 8 rabbits as the control and 12 rabbits for the histamine treated group following results were obtained: 1. Both of the concentration curves, arterial and venous, declined rapidly at_first and slowly later on and approached same equilibrium concentration with the passage of time after a single injection. The time at which attained the same concentration was $2.0{\pm}0.54\;min.$ in the control and $4.3{\pm}1.92\;min.$ in the histamine treated group with respect to antipyrine. On the other hand in the case of urea they were $2.4{\pm}0.59\;min.$ in the control and $4.4{\pm}1.31\;min.$ in the histamine group, respectively. In the histamine treated group enlarged spaces for distribution of test substances were postulated. 2. The concentration of antipyrine in the brain tissue water revealed no significant differences between the control and experimental groups, showing $212{\pm}40.2\;mg/l$ in the control and $206{\pm}64.1\;mg/l$ in the histamine treated group. On the other hand urea revealed higher value in the histamine treated group than in the control, showing an enhanced penetration of urea into the tissue after injection of histamine. Urea concentration in the brain water was $32.3{\pm}3.36\;mg%$ in the control and $39.2{\pm}4.25\;mg%$ in the histamine treated group. 3. The distribution ratio of antipyrine in the brain tissue was very close to unity in the histamine treated animals as well as in the control. 4. The average of the distribution ratio of urea in the control animals was 0.77 and it showed the presence of blood-brain barrier with regard to urea. However in the histamine treated animals the distribution ratios climbed up to 0.86 and they were closer to unity than in the control animals. Out of 12 cases 5 were greater than 0.9 and 8 exceeded 0.85. It appeared that histamine enhanced the penetration of urea through the barrier. 5. Histamine injection and or hemorrhage caused an elevation of the concentration of potassium in plasma. In the event that histamine and hemorrhage were applied together the elevation of potassium exceed the elevation seen at the histamine alone. There was no evidence that the leakage of potassium from the brain tissue was dominant in comparison with the general leakage from the whole body.

  • PDF

Angiotensin-converting Enzyme Gene Polymorphism and Cerebrovascular Disease in Korean population (한국인의 ACE(Angiotensin-converting Enzyme) 유전자의 다형성과 뇌혈관 질환과의 관계에 대한 연구)

  • Lee Jin Woo;Lee Kyung Jin;Rho Sam Woong;Kim Jae Jong;Bae Hyung Sup;Hong Moo Chang;Shin Min Kyu;Kim Young Suk;Bae Hyun Su
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.16 no.4
    • /
    • pp.724-728
    • /
    • 2002
  • Angiotensin-converting enzyme (ACE) gene polymorphism, which consists of presence (insertion, I) or absence (deletion, D) of a 250-bp fragment, is associated with ischemic heart disease, renovascular disease, systemic lupus erythematosus. Subjects with the DD genotype have higher levels of circulating ACE than subjects with the II genotype and show an increased tendency towards vascular wall thickness and contribute to the development of vascular disease. But the association between I/D polymorphism of the ACE gene and cerebrovascular disease is still controversial. The aim of this study was to determine whether the DNA polymorphism of the ACE are associated with cerebrovascular disease in Korean population. The study group comprised 377 Korean patients admitted to Kyunghee Oriental Medical Center in the year of 2000 for the treatment of brain infarction or brain hemorrhage. Magnetic resonance imaging(MRI) was performed for each patient to determine the stroke phenotype, infarction or hemorrhage. The 183 subjects without evidence of brain infarction or brain hemorrhage were selected from the some ethnical population(control group). Venous blood samples were drawn from each subject for the extraction of DNA. Genotypes of ACE were determined by polymerase chain reaction amplification of the genomic DNA. Case and control genotype frequencies were compared by chi-square testing. Both the patients and the controls were classified respectively into 4 groups: age less than forty years, age forty one to fifty, age fifty one to sixty, age greater than sixty years. There were no significant differences in the distributions of ACE genotypes among the patients with infarction, with hemorrhage and controls (Infarction: D/D 15.8%, I/D 46.7%, I/I 37.5%, Hemorrhage: D/D 15.1%, I/D 46.5%, I/I 38.4%, Control: D/D 18.6%, I/D 50.3%, I/I 31.2%). There was a significant difference in the distribution of ACE genotypes between the age greater than sixty year subgroup of patient with brain hemorrhage and the control (Hemorrhage: D/D 0%, I/D 55.6%, I/I 44.4%, Control: D/D 13.0%, I/D 63.0%, I/I 23.9%; Pearson Chi-Square value 5.956, P<0.05). Furthermore, the frequency of the ACE D/D type declined with increasing age both in the patient and control group (Patient group: age < 50 D/D 21.5%, age > 50 D/D 14.42%; Control group: age < 50 D/D 21.0%, age > 50 D/D 14.2%). In conclusion there is no clear association between ACE polymorphism and cerebrovascular disease in Korean population. Although, there was a tendency for the frequency of the ACE D/D type declined with increasing age in both patients and controls.

Stressful Life Events, Health Symptoms, Social Support and Coping/in Early Adolescents (스트레스생활사건, 건강문제, 대응, 사회적 지지의 관계 -청소년을 대상으로-)

  • 오가실;한정석
    • Journal of Korean Academy of Nursing
    • /
    • v.20 no.3
    • /
    • pp.414-429
    • /
    • 1990
  • Numerous research reports have substantiated the role of stressful life events in relation to the onset of health changes. The relationship tends to hold across different age groups. Theoretically, adolescence has been considered a developmental crisis period of great stress, impoverished coping skills and high vulnerability to biological, social and psychological demands. The research problem addressed by this study was to examine the relationships between stressful life events and health symptom patterns, and the effect of two variables, coping and social, support, theoretically considered to mediate the relationship between stress and health symptoms in adolescents. The following five hypotheses were tested in this research : 1. Health symptoms are positively related to stressful life events in adolescents, 2. Health symptoms are negatively related to coping in adolescents, 3. Health symptoms are negatively related to social support in adolescents, 4. When coping is controlled, the relationship between health symptoms and stressful life events will decrease, and 5. When social support is controlled, the relationship between health symptoms and stressful life events will increase. The study subjects consisted of 1090 high school students of the metropolitan city of Seoul. The following sampling procedure was used : 1. Of the 169 high schools in nine school administrative districts in the city, a proportional sample of ten schools was selected. 2. One class from each of the freshman and sophomore was randomly selected and all the students who were in the sampled class were used as the study sample. The study was limited to freshman and sophomore adolescents, aged 15 to 18(mean=16.6). Of the 1090 subjects 688(63%) were boys and 402(37%) were girls. An Adolescent Inventory of Stressful Life Events, a Health Symptom Questionnaire and an Adolescent Coping Inventory were adapted for this study. The Norbeck Social Support questionnaire was utilized to collect the data on perceived social support. Five high school teachers in the areas of school health and counselling reviewed the items of each questionnaire for content validity. A pilot study was undertaken to ascertain reliability. Fifty three high school students responded to the questionnaires and gave their opinions on the items. For stressful life events, health symptoms, coping, and social support, the Cronbach's alpha's on the study were .70, .94, .77, and .76, respectively. Research assistants attended all the sampled classes with the school proctor to explain the purpose and procedures of the study to the students. The questionnaires along with a ballpoint pen were distributed to the students who were asked to complete each item. The research assistants left the ballpoint pen with the students as a gift for their cooperation. An average of 50 minutes was required to complete the questionnaires. Using an SPSS, the first, three hypotheses were tested using Gamma, a measure of association for ordinal variables. Partial gamma was used to test the fourth and fifth hypotheses. Patterns of elaboration described by Babbie were selected to interpret the relationship of the three variable analyses. The significance of gamma was determined by Chisquare at a .05 level of significance. There was a positive relationship between health symptoms and stressful life events(Gamma=.35, p=.000). Thus the first hypothesis was supported. Unexpectedly, coping was positively related with health symptoms(Gamma=.13, p=.000). That is, the higher the coping levels, the greater number of health problems. The third hypothesis, the higher the level of social support, the fewer the health symptoms, was not accepted in this adolescent study group. When coping was controlled, under the condition of low coping the association between health symptoms and stressful life events increased significantly to a partial gamma of .39, and under the condition of high coping it was .30. According to the elaboration model, when one partial relationship is the same or greater than the original and the other is smaller, the control variable should be considered to be specifying the conditions. When social support was controlled the relationship between stressful life events and health symptoms increased under the condition of low social support, but with high social support, the relationship decreased. Both partial gamma were statistically significant at .05 level(.43 and .26 relatively). It can be interpreted that stressful life events are strongly and positively related to health symptoms under the condition of low social support, however this relationship can not be expected with high social support. Thus, the last two hypotheses were conditionally sustained. In this study, the relationships between stressful life events and health symptoms, and the specified me diating roles of coping and social support were found to have statistical interaction. This finding supports the theoretical position of this study. It suggests that stressful life events would create high susceptability to biological social and psychological health symptoms and coping and social support buffering the relationship between stressful life events and health symptom. The findings of this study have implications for nursing practice. When adolescents are confronted with non-developmental life events that are perceived as stressful, nurses should recognize the evidence of the stress-buffering effect of coping and social support on health symptoms and utilize the diverse sources of social support that are readily available to adolescents.

  • PDF

A Study on the Qiu Zheng Lu (求正錄) of Zhang J ie Bin (張介賓) (장개빈(張介賓)의 <구정록(求正錄)>에 관한 연구(硏究))

  • Park, Hyuk-Kyu;Maeng, Woong Jea
    • The Journal of Korean Medical History
    • /
    • v.18 no.2
    • /
    • pp.137-187
    • /
    • 2005
  • This thesis study of the medical concept Qiu Zheng Lu (求正錄) is discussed in the Lei Jing Fu Yi (類經附翼), a book authored by Zhang Jie Bin (張介賓) a medical doctor during the Chinese Ming (明) dynasty (1368-1683). The meaning of Qiu Zheng Lu (求正錄) is "searching for the rightness." In his book Zhang Jie Bin (張介賓) intended to clarify Qiu Zheng Lu (求正錄) by delineating the concept into four categories. These are: Sanjiao Baoluo Mingmen Bian (三焦包絡命門 辨) the theory of the triple warmer, the Pericardium, the Gate of Life ; Da Bao Lun (大寶論) the theory of the great treasure of the human body; Zhen Yin Lun (眞陰論) the theory of true-yin fluid; and Shi Er Zang Mai Hou Bu Wei Lun (十二臟脈候部位論) the theory of the part of the pulse and its condition in regards to the twelve viscera. Sanjiao Baoluo Mingmen Bian (三焦包絡命門辨), the theory of the triple warmer, the Pericardium, the Gate of Life. The triple warmer (三焦: Sanjiao) is composed of three parts: the upper, middle, and lower. This concept is also connected with the functions and roles of the vital organs. The upper burner is related to the heart and lungs. The middle burner is related to the liver and spleen. Whereas, the lower burner is related to the kidneys. Bao-Luo (包絡) is the Pericardium, the envelope of the heart, serving as the protector of the heart. Ming-Men (命門) is the Gate of Life, reffering to the vitals of life. It functions as kidney-yang which is considered as the origin of yang-energy of the human body, and serves partly as the function of cortico-adrenal gland in modern medicine. Zhang Jie Bin (張介賓) discussed the Da Bao Lun (大寶論) as the most important function in the human body because the Da Bao (大寶/great treasure) is the true-yang (眞陽) which is the affective force for physiological functions, and as the source of energy for life activities. Moreover, true-yang (眞陽) functions both as a heater and thermometer that warms the human body and indicates vitality by levels of body warmth respectively. The Zhen Yin Lun (眞陰論) theory states that if true-yang (眞陽) is energy, then true-yin (眞陰) is the source of energy. This can be likened to a tree with roots which absorbs nutrients from the ground (source), and spreads the nutrients (energy) through its branches. Thus, true-yin (眞陰) is the root cause for later functional activities of true-yang (眞陽). In Shi Er Zang Mai Hou Bu Wei Lun (十二臟脈候部位論) the theory of the pulse (脈 /Mai) and its condition in regards to the twelve viscera, Zhang Jie Bin (張介賓) insisted that when a diagnoses by the pulse is made the five vital organs and the six viscera (五臟六腑) of a human body should be harmoniously arranged in accordance with its respective part of the pulse. Furthermore, Zhang Jie Bin (張介賓) supported his theory with evidence from earlier Chinese medical doctors. And, by stating that human beings must cultivate and preserve their true-yin (眞陰) and true-yang (眞陽) energies he therefore created four new prescriptions called: Zuoguiyin (左歸飮), Youguiyin (右歸飮), Zuoguiwan (左 歸丸), Youguiwan (右歸丸). To further clarify his theory Zhang Jie Bin (張介賓) considered that the function of true-yang (眞陽) and true-yin (眞陰) is expressed by Ming-Men (命門). This theory is that for humans to be spiritually and physically healthy they must live in accord with natural law. Also, within the framework of natural law, astronomical and geographical factors must be considered for complete, holistic, health. Thus, Ming-Men is the basis for healthy living in the modern world.

  • PDF

Efficacy and Safety of Intraveous Iron Sucrose in the Perioperatively Anemic Patients of Gastrectomy (위 절제 수술 전후 빈혈 환자에 있어 철수크로오스의 유효성 및 안전성)

  • Yoo, Moon-Won;Cho, Jae-Jin;Lee, In-Kyu;Ahn, Hye-Seong;Jeong, Sang-Ho;Lee, Hyuk-Joon;Kim, Hyung-Ho;Lee, Kuhn-Uk;Yang, Han-Kwang
    • Journal of Gastric Cancer
    • /
    • v.8 no.1
    • /
    • pp.35-39
    • /
    • 2008
  • Purpose: This study was aimed to evaluate the efficacy and safety of of intravenous iron sucrose ($Venoferrum^{(R)}$) for treating the perioperative anemic gastrectomy patients. Materials and Methods: From September 2006 to February 2007 at Seoul National University Hospital, the gastrectomy patients who displayed perioperative anemia (7.0 g/dl $\leq$ hemoglobin levels (Hb) < 11.0 g/dl) and who were admitted or visited the outpatient clinic of the Department of surgery, were divided into two groups. The preoperative (${\leq}\;2{\sim}3$ weeks before gastrectomy) or postoperative ($\geq$ 1 month after gastrectomy) patients without evidence of acute bleeding were included into Group 1. The immediate postoperative (< 1 month after gastrectomy) patients with stable vital signs were included into Group 2. The age, gender, diagnosis, Hb, hematocrit (Hct), mean corpuscular volume (MCV), serum ferritin (SF), total iron binding capacity (TIBC), serum iron and reticulocyte counts (RC) were evaluated before and after intravenous iron sucrose administration. The adverse effects of drugs were investigated. Results: The number of patients of group 1 and group 2 was 79 and 46, respectively. In group 1, there was a statistically significant difference in the Hb, Hct, MCV, SF, RC and TIBC with each mean change of 1.3 g/dl, 4.1%, 3.1ft, 195 ng/ml, 0.2% and -86.4 ug/dl, respectively. In group 2, there was a statistically significant difference in the Hb, Hct, MCV, SF and RC with each mean change of 1.8 g/dl, 6.1%, 3.4fl, 260 ng/ml and 0.3%, respectively. Two patients (1.6%) suffered local thrombophlebitis as an adverse effect. Conclusion: Intravenous iron sucrose for the perioperative anemia of gastrectomy patients was efficacious in the short period without significant adverse effects.

  • PDF

Technical Inefficiency in Korea's Manufacturing Industries (한국(韓國) 제조업(製造業)의 기술적(技術的) 효율성(效率性) : 산업별(産業別) 기술적(技術的) 효율성(效率性)의 추정(推定))

  • Yoo, Seong-min;Lee, In-chan
    • KDI Journal of Economic Policy
    • /
    • v.12 no.2
    • /
    • pp.51-79
    • /
    • 1990
  • Research on technical efficiency, an important dimension of market performance, had received little attention until recently by most industrial organization empiricists, the reason being that traditional microeconomic theory simply assumed away any form of inefficiency in production. Recently, however, an increasing number of research efforts have been conducted to answer questions such as: To what extent do technical ineffciencies exist in the production activities of firms and plants? What are the factors accounting for the level of inefficiency found and those explaining the interindustry difference in technical inefficiency? Are there any significant international differences in the levels of technical efficiency and, if so, how can we reconcile these results with the observed pattern of international trade, etc? As the first in a series of studies on the technical efficiency of Korea's manufacturing industries, this paper attempts to answer some of these questions. Since the estimation of technical efficiency requires the use of plant-level data for each of the five-digit KSIC industries available from the Census of Manufactures, one may consture the findings of this paper as empirical evidence of technical efficiency in Korea's manufacturing industries at the most disaggregated level. We start by clarifying the relationship among the various concepts of efficiency-allocative effciency, factor-price efficiency, technical efficiency, Leibenstein's X-efficiency, and scale efficiency. It then becomes clear that unless certain ceteris paribus assumptions are satisfied, our estimates of technical inefficiency are in fact related to factor price inefficiency as well. The empirical model employed is, what is called, a stochastic frontier production function which divides the stochastic term into two different components-one with a symmetric distribution for pure white noise and the other for technical inefficiency with an asymmetric distribution. A translog production function is assumed for the functional relationship between inputs and output, and was estimated by the corrected ordinary least squares method. The second and third sample moments of the regression residuals are then used to yield estimates of four different types of measures for technical (in) efficiency. The entire range of manufacturing industries can be divided into two groups, depending on whether or not the distribution of estimated regression residuals allows a successful estimation of technical efficiency. The regression equation employing value added as the dependent variable gives a greater number of "successful" industries than the one using gross output. The correlation among estimates of the different measures of efficiency appears to be high, while the estimates of efficiency based on different regression equations seem almost uncorrelated. Thus, in the subsequent analysis of the determinants of interindustry variations in technical efficiency, the choice of the regression equation in the previous stage will affect the outcome significantly.

  • PDF

Experimental renal artery embolization with iohexol-ethanol and barium-ethanol in dogs (개에서 iohexol-ethanol 및 barium-ethanol을 이용한 실험적 신동맥 색전술)

  • Hwang, Guk-jin;Chang, Dongwoo;Seo, Minho;Jung, Joohyun;Choi, Mincheol;Yoon, Junghee
    • Korean Journal of Veterinary Research
    • /
    • v.41 no.3
    • /
    • pp.429-436
    • /
    • 2001
  • The present study was performed to investigate the effect of iohexol-ethanol mixture and barium-ethanol mixture on the induction of transcatheter renal artery embolization in healthy 18 dogs, which were divided into two groups of 9 dogs and the 9 dogs were divided into 3 subgroups of 3 dogs. The renal artery embolization was undertaken unilaterally with the dose of 1.5, 2.0, and 3.0 ml/kg iohexol-ehtanol mixture and with the dose of 0.2, 0.4, and 0.8 ml/kg barium-ethanol mixture. And serum chemistry on 0, 1,3, 7, and 14 days, intravenous pyelography on 7days, angiography on 14 days, and histopathology on 14 days were evaluated. Serum BUN and creatinine concentration of two groups with iohexol-ethanol mixture and barium-ethanol mixture administration were mildly increased a t 1 day after injection of embolic materials and then returned to baseline. No significant changes in BUN and creatinine levels occurred in any of dogs. In all dogs with the dose of 1.5 ml/kg iohexol-ethanol mixture, the renal arteries were not embolized. All dogs with the dose of 3.0 ml/kg died. In all dogs with the dose of 2.10 ml/kg, the treated arteries were completely occluded. In barium-ethanol mixture administered group, the renal artery in one dog with the dose of 0.2 ml/kg was not embolized. In all dogs with the dose of 0.8 ml/kg, the renal arteries were completely embolized, but loac overembolization occured in two dogs. All animals with the dose of 0.4 ml/kg had effective embolization and no evidence of radiopaque barium opacity in systemic arteries distal to the renal-artery was found. All embolized kidneys were shrunk and decreased in size in gross examination and were shown diffuse necrosis in histopathologic examination. In the present study, renal arteries were embolized with the dose of 2.0 ml/kg iohexol-ethanol mixture or 0.4 ml/kg barium-ethanol mixture. And it is considered that the dose had a satisfactory embolic effect.

  • PDF

Earthquake impacts on hydrology: a case study from the Canterbury, New Zealand earthquakes of 2010 and 2011

  • Davie, Tim;Smith, Jeff;Scott, David;Ezzy, Tim;Cox, Simon;Rutter, Helen
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2011.05a
    • /
    • pp.8-9
    • /
    • 2011
  • On 4 September 2010 an earthquake of magnitude 7.1 on the Richter scale occurred on the Canterbury Plains in the South Island of New Zealand. The Canterbury Plains are an area of extensive groundwater and spring fed surface water systems. Since the September earthquake there have been several thousand aftershocks (Fig. 1), the largest being a 6.3 magnitude quake which occurred close to the centre of Christchurch on 22February 2011. This second quake caused extensive damage to the city of Christchurch including the deaths of 189 people. Both of these quakes had marked hydrological impacts. Water is a vital natural resource for Canterburywith groundwater being extracted for potable supply and both ground and surface water being used extensively for agricultural and horticultural irrigation.The groundwater is of very high quality so that the city of Christchurch (population approx. 400,000) supplies untreated artesian water to the majority of households and businesses. Both earthquakes caused immediate hydrological effects, the most dramatic of which was the liquefaction of sediments and the release of shallow groundwater containing a fine grey silt-sand material. The liquefaction that occurred fitted within the empirical relationship between distance from epicentre and magnitude of quake described by Montgomery et al. (2003). . It appears that liquefaction resulted in development of discontinuities in confining layers. In some cases these appear to have been maintained by artesian pressure and continuing flow, and the springs are continuing to flow even now. In spring-fed streams there was an increase in flow that lasted for several days and in some cases flows remained high for several months afterwards although this could be linked to a very wet winter prior to the September earthquake. Analysis of the slope of baseflow recession for a spring-fed stream before and after the September earthquake shows no change, indicating no substantial change in the aquifer structure that feeds this stream.A complicating factor for consideration of river flows was that in some places the liquefaction of shallow sediments led to lateral spreading of river banks. The lateral spread lessened the channel cross section so water levels rose although the flow might not have risen accordingly. Groundwater level peaks moved both up and down, depending on the location of wells. Groundwater level changes for the two earthquakes were strongly related to the proximity to the epicentre. The February 2011 earthquake resulted in significantly larger groundwater level changes in eastern Christchurch than occurred in September 2010. In a well of similar distance from both epicentres the two events resulted in a similar sized increase in water level but the slightly slower rate of increase and the markedly slower recession recorded in the February event suggests that the well may have been partially blocked by sediment flowing into the well at depth. The effects of the February earthquake were more localised and in the area to the west of Christchurch it was the earlier earthquake that had greater impact. Many of the recorded responses have been compromised, or complicated, by damage or clogging and further inspections will need to be carried out to allow a more definitive interpretation. Nevertheless, it is reasonable to provisionally conclude that there is no clear evidence of significant change in aquifer pressures or properties. The different response of groundwater to earthquakes across the Canterbury Plains is the subject of a new research project about to start that uses the information to improve groundwater characterisation for the region. Montgomery D.R., Greenberg H.M., Smith D.T. (2003) Stream flow response to the Nisqually earthquake. Earth & Planetary Science Letters 209 19-28.

  • PDF

The Effects of Female Wage on Fertility in Korea (여성의 임금수준이 출산율에 미치는 영향 분석)

  • Kim, Jungho
    • KDI Journal of Economic Policy
    • /
    • v.31 no.1
    • /
    • pp.105-138
    • /
    • 2009
  • Although the decline in fertility rate is generally observed along the history of economic development throughout the world, the continuing decline hitting below the replacement level in Korea over the recent years gathered serious social concerns on the ground that it accelerates the process of population aging. The total fertility rate in Koreareached 2.08 in 1983, and gradually fell to the levels of 1.08 in 2005 and 1.26 in 2007. The policy debate over the role of the government has been focused mainly on the level of theoretical discussion without substantial basis on firm empirical evidence and the determinants of fertility. The objective of the paper is to empirically investigate the fertility effect of the female wage, which is understood as one of the most important determinants of fertility in Koreasince 1980 focusing on one aspect of fertility, namely birth spacing. Using the Korean National Fertility Survey conducted in 2006, I estimate a duration model of first and second births taking into account individual heterogeneity, which turned out to be an important factor to control for. Compared with previous studies in the literature on the Korean fertility, the study has an advantage of using the complete pregnancy history of women in a more representative sample. Unlike the previous studies, the analysis also deals with the endogeneity of marriage by treating a certain age, rather than age at marriage, as the time in which a woman becomes exposed to the risk of pregnancy. The study shares the common problem in the literature on birth spacing of lacking relevant wage information for respondents in a retrospective survey. I estimate the wage series as a function of the basic characteristics using the annual Wage Structure Survey from 1980 to 2005, which is considered as a nationally representative sample for wage information of employees. The results suggest that the increase in female wage by 10 percent leads to a decrease in second birth hazard by 0.56~0.92 percentage points and that the increase in spouse's wage by the equal amount is accompanied by the increase in second birth hazard by 0.36~1.13 percentage points. These estimates are more precisely estimated and of smaller magnitude than those presented by the previous studies. The results are robust to the different specifications of the wage equation. The simulation analysis based on the predicted values shows that about 17% of the change in the second birth hazard over the period 1980 to 2005 was due to the change in the female wage. Although there is some limitation in data, the results can be viewed as one estimate of the role of female wage on the recent fertility decline in Korea. The question raised by the paper is not a normative one of whether a government should promote childbearing but a positive one thatexplains fertility decline. Therefore, if there is a wide consensus on promoting childbearing, the finding suggests that the policies designed to reduce the opportunity cost of women in the labor market would be effective. The recent movement of implementing a wide range of family-friendly policies including child care support, maternity leave, parental leave and tax benefit in developed countries should be understood in this context.

  • PDF

Hypolipidemic and Hypoinsulinemic Effects of Dietary Fiber from Agar in C57BL/6N Mice Fed a High-fat Diet (고지방사료를 섭취한 C57BL/6N 마우스에서 한천식이섬유의 혈청 지질과 인슐린 농도 저해효과)

  • Park, Jin Ju;Kim, Ji Eun;Yun, Woo Bin;Lee, Mi Lim;Choi, Jun Young;Song, Bo Ram;Kim, Dong Seob;Lee, Chung Yeoul;Lee, Hee Seob;Lim, Yong;Jung, Min Wook;Hwan, Dae Youn
    • Journal of Life Science
    • /
    • v.27 no.8
    • /
    • pp.937-944
    • /
    • 2017
  • To investigate the beneficial effects of fiber derived from agar on the lipid and glucose metabolism of obese model mice, changes in the fat accumulation, lipid content, and insulin concentration were measured in C57BL/6N mice fed a high-fat diet (HFD) and treated with a beverage containing agar (BCA) for 9 weeks. The feed efficiency ratio was significantly decreased in the HFD+BCA treatment group, although the body weight and food intake were maintained a constant level. Also, the fat accumulation in the fatty tissue and liver were lower in the HFD+BCA treatment group than in the HFD+Vehicle treatment group. Furthermore, a significant decrease was detected in the levels of total cholesterol (TC) and LDL after the BCA treatment, while a constant HDL level was maintained in the same group. Moreover, the serum insulin concentration was significantly decreased in the HFD+BCALo (Low concentration) and HFD+BCAMi (Middle concentration) groups compared to the HFD+Vehicle group. Therefore, the results suggest that the long-term administration of dietary fiber from agar can improve fat accumulation in the fatty tissue and liver, the serum lipid profile, and the insulin concentration in the blood. Also, the results provide evidence that the inclusion of agar fiber in beverages results in significant hypolipidemic and hypoinsulinemic effects.