• The Korean Journal of Physiology
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• v.3 no.2
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• pp.9-16
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• 1969

It is well known that a number of -SH and -SS containing substances afford a certain measure of protection against radiation effects in many biological systems, and it is conceivable that inherent -SH levels in Ehrlich ascites tumour (ELD)cells may be of decisive improtance with respect to the development of cellular radiation injury. So far, little effort has been directed to elucidate the changes in levels of different -SH and -SS groups in ELD cells when the tumour-bearing whole animal was subjected to the sublethal dose of X-irradiation. The present study was designed to bring some lights in the possible changes of and relationship between various sulfhydryl levels, such as P-SH, NP-SH and NP-SS, as well as the content of protein and cell volume of ELD cells, after subjecting the ELD mice to 1,200 r of X-irradiation. The animals used in this experiment were all mixed bred mice of $20{\sim}25\;gm$ in body weight (approximately 2 months old) irrespective of sex. 12 mice in one experiment were inoculated intraperitoneally with 0.2 ml of ascites tumour cells $(2{\times}10^6\;cells)$, and on the 7th day of the tumour growth, they were X-irradiated with 1,200 r, using the conventional X-ray machine under the following conditions: 200 Kv at 15 mA, 0.5 mm Cu filter, target-skin distance: 50 cm. Radiation dose was measured with the the Philip integrating dosimeter. At 24, 36, 48 and 60 hours after the X-irradiation, the mice were killed by cervical dislocation, and the tumours were taken out. Freshly withdrawn ascites tumours were placed in ice, and immediately the cell concentration was measured with the Coulter Cell Counter (Model B), and the hematocrit of the tumour cells were also determined. Cell volume was thus calculated by the cell concentration and hematocrit value. P-SH content of ELD cells was measured potentiometrically according to the method of Calcutt & Doxey, and NP-SH and NP-SS contents were measured spectrophotometrically by the method described by Ellman. Protein content of ELD cells was determined with the Folin phenol reagent by Lowry et al. Altogether, 48 experimental mice were used, and 12 mice with the only exception of X-irradiation were used as the control. Results obtained indicate that the contents of all the cellular sulfhydryl groups as well as cell volume and protein content of the ELD cells increase significantly as time progresses after the sub-lethal X-ray dose of 1,200 r was given and that all the increase is in a lineal fashion. The regression lines of the relative values, (i. e., taking each control value as 1) of all the values obtained, and the regression lines of cell volume, protein and NP-SH are identical, whereas those of NP-SS and P-SH appear to be widely seperated. However, the difference of those two lines (NP-SS & P-SH) were found to be not significant statistically (p>0.05). Therefore, it can be concluded from the above results that all the values examined increase in a lineal fashion with no statistically significant difference among them. Also, with the radiation dose of 1,200 r, the ELD cell becomes enlarged and swollen progressively up to 60 hours post-irradiation and it becomes more than two times of the original normal size at 60 hours after the irradiation, and up to this stage, it seems apparent that the cell division has been slow due to the X-irradiation applied in this experiment. It is well understandable that the contents of NP-SH, NP-SS, P-SH and protein of the ELD cells increase in parallel with the increase of the cell volume by the X-ray does used, but it also seems interesting to note that all the cellular substances tested show no appreciable difference in the pattern of increase.

• Environmental and Resource Economics Review
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• v.14 no.1
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• pp.167-199
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• 2005

The following policy implications can be drawn from this study: 1) The Air Pollution Emission Amount Report published by the Ministry of Environment since 1991 classifies industries into 4 sectors, i. e., heating, manufacturing, transportation and power generation. Currently, the usability of report is very low and extra efforts should be given to refine the current statistics and to improve the industrial classification. 2) Big pollution industries are as follows - s7, s17 and s20. The current air pollution control policy for these sectors compared to other sectors are found to be inefficient. This finding should be noted in the implementation of future air pollution policy. 3) s10 and s17 are found to be a big polluting industrial sector and its pollution reduction effect is also significant. 4) The effect of emission coefficient (${\Delta}f$) has the biggest impact on the reduction of emission amount change and the effect of economic growth coefficient (${\Delta}y$) has the biggest impact on the increase of emission volume. The effect of production technology factor (${\Delta}D$) and the effect of the change of the final demand structure (${\Delta}u$) are insignificant in terms of the change of emission volume. 5) Further studies on emission estimation techniques on each industry sector and the economic analysis are required to promote effective enforcement of the total volume control system of air pollutants, the differential management of pollution causing industrial sectors and the integration of environment and economy. 6) Korea's economic growth in 1990 is not pollution-driven in terms of the Barry Commoner's hypothesis, even though the overall industrial structure and the demand structure are not environmentally friendly. It indicates that environmental policies for the improvement of air quality depend mainly on the government initiatives and systematic national level consideration of industrial structures and the development of green technologies are not fully incorporated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.84-91
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• 1996

Heat flux of the East China Sea was estimated with the bulk method, the East China mount based on the marine meteorological data and cloud amount data observed by a satellite. Solar radiation is maximum in May and minimum in December. Its amount decreases gradually southward during the winter half year (from October to March), and increases northward during the summer half year (from April to September) due to the influence of Changma (Baiu) front. The spatial difference of long-wave radiation is relatively small, but its temporal difference is quite large, i.e., the value in February is about two times greater than that in July. The spatial patterns of sensible and latent heat fluxes reflect well the effect of current distribution in this region. The heat loss from the ocean surface is more than $830Wm^{-2}$ in winter, which is five times greater than the net radiation amount during the same period, The annual net heat flux is negative, which means heat loss from the sea surface, in the whole region over the East China Sea. The region with the largest loss of more than $400Wm^{-2}$ in January is observed over the southwestern Kyushu. The annual mean value of solar radiation, long-wave radiation, sensible and latent heat fluxes are estimated $187Wm^{-2},\;-52Wm^{-2},\;-30Wm^{-2}\;and\;-137Wm^{-2}$, respectively, consequently the East China Sea losses the energy of $32Wm^{-2}(2.48\times10^{13}W)$. Through the heat exchange between the air and the sea, the heat energy of $0.4\times10^{13}W$ is supplied from the air to the sea in A region (the Yellow Sea), $2.1\times10^{13}W$ in B region (the East China Sea) and $1.7\times10^{13}W$ in C region (the Kuroshio part), respectively.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.613-629
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• 1996

River terraces of glacial and interglacial periods are most developed in the Ungcheon River, midwestern coastal region of south Korea. Among these terraces, interglacial river terraces correspond to the thalassostatic terraces of eastern coastal region of Korea. Thus the former shoreline altitudes of the coastal region around Ungcheon River can be estimated by using relative heights of these interglacial thalassostatic terraces of Ungcheon River The former shoreline altitudes estimated from interglacial thalassostatic terraces of Ungcheon River are 80m, 50${\sim}$60m, 40${\sim}$45m, 30m, 25m(?), 15${\sim}$20m, and 10m. These estimates are almost identical with those of Quaternary sea levels of eastern coastal region. Among the above estimates of Ungcheon River, the former shoreline altituded of 15~20m and 10m correspond to the ancient sea levels of $\pm$18m and $\pm$10m of eastern coastal region which were injudged as the last interglacial culmination period and late warmer period of the last interglacia(5e and 5a substages of oxygen isotope stage), respectively. Therefore there is a possibility that the rest of the above former shoreline altitudes of the coastal region aroune Jngcheon River also correspond to those of eastern coastal region. On the basis of the above possibility it can be proposed that the eastern and western coastal region of Korean Peninsula have undergone tectonic uplift of equall amount since the middle Quaternary Period.

• The Korean Journal of Pharmacology
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• v.32 no.1
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• pp.23-29
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• 1996

According to the traditional receptor model, competitive antagonists share with agonists the ability to bind to a common site on receptors, but they are different from agonist in that they cannot trigger the biological response-i.e., they lack intrinsic efficacy. Recent findings extend the model by indicating that not all antagonists display an intrinsic efficacy of zero but that some display 'inverse agonism'. In the present study we studied the inverse agonism at $A_1$ adenosine receptors in membranes prepared from rat cerebral cortex. Eight commercially available $A_1$ adenosine receptor antagonists (CGS-15943, ADPX, CPT, DPCPX, DPX, N-0840, PACPX and 8-PT) were screened for inverse agonism by measuring the extent of $[^{35}S]guanosine-5'-({\gamma}-thio)$ triphosphate $([^{35}S]GTP_{\gamma}S)$ binding to G proteins. The agonist-induced stimulation of $[^{35}S]GTP_{\gamma}S$ bindings was completely blocked in the presence of $A_1$ adenosine receptor antagonists. Under optimal conditions, two types of antagonists could be distinguished. Seven antagonists including DPCPX decreased the basal $[^{35}S]GTP_{\gamma}S$ binding in the absence of agonist, displaying inverse agonist activity. One (CGS-15943) had no effect on the basal bindings. N-ethylmaleimide treatment reduced the basal bindings as well as agonist-mediated stimulation of $[^{35}S]GTP_{\gamma}S$ bindings, indicating that a substantial amount of this binding reflects an activated state of the C proteins. In good agreement with these findings, 0.1 mM GTP decreased the apparent affinity of the receptors for the agonist PIA, increased that for DPCPX, and had no effect on that for CGS-15943.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.157-163
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• 2005

An experiment was conducted to investigate the effects of dietary betaine and protein levels on performance, internal e99 Qualify, blood composition, abdominal fat and liver amino acid concentration in laying hens. A total of 432 ISA-Brown laying hens were randomly allotted to four treatments with six replications for twenty few weeks. Treatments were factorially designed with two levels of crude protein(14.5 and $16.5\%$) and two levels of betaine(0 and 600ppm). The egg production was increased by feeding $16.5\%$ protein-fed group compared to that of $14.5\%$ protein-fed groups(P<0.05), but was different from betaine supplementation. Increasing protein and betaine supplementation to diets improved egg weight, egg mass and fred conversion(P<0.05). Eggshell breaking strength, thickness and Haugh unit were not influenced by either dietary betaine or protein levels. Dietary betaine did not affect serum total protein, albumin and uric acid concentration, whereas uric acid concentration was increased in $16.5\%$ protein-fed groups(P<0.05). The deposition of abdominal fat was lower in 600ppm betaine groups compared to those fed on 0ppm betaine groups(P<0.05). Concentration of the most hepatic amino acids were affected by dietary protein levels and betaine supplementation. There were synergistic effect between dietary protein and betaine. These results suggested that dietary betaine can improve the egg weight, mass, feed conversion and decrease the abdominal fat, but increase the hepatic amino acid contents.

• Korean Journal of Poultry Science
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• v.35 no.2
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• pp.163-169
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• 2008

A total of 17 polymorphic microsatellite markers on chromosome 1 were used for allelic association tests with phenotypic traits in Korean native chicken. Chi-square tests were performed to compare the frequencies of individual alleles between the high and the low trait groups. The frequency of allele 123 of MCW0160 showed a significant difference between the high and the low groups in the trait of egg weight (EW). Three markers, namely ADL0234, UMA1.125 and ADL0101, were found to show significant differences in allelic distribution for the trait of the first lay day (FLD). UMA1.117, ADL0020, UMA 1.019, LMA1 and ADL0238 were found to show significant differences in allelic distribution for the trait of body weight (BW). ADL0101 and ADL0238 were found to show significant differences in allelic distribution for the trait of number of egg production(EP). In this study, we identified the QTL for economic traits at around 94 (MCW0160), 151 (ADL0234), 170 (UMA1.125), 225 (UMA1.117), 285 (ADL0020), 387 (UMA1.019), 418 (LMA1), 500 (ADL0101) and 520 (ADL0238) cM on chromosome 1 in Korean native chicken. The results provided a useful guideline for identification of positional candidate gene and marker-assisted selection for economic traits in Korean native chicken.

• Journal of Science Education
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• v.38 no.3
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• pp.718-736
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• 2014

This study was intended to determine PCK of the middle school science teachers on Mendelian genetics and factors influenced to form their PCKs. Two science teachers with biology major with a teaching experience over 5 years were chosen as the subject. Data were collected by class observation, semi-structured interview, teacher questionnaire survey, Content Representation and Pedagogical and Professional-experience Repertoire. The collected data were analyzed based on Magnusson's PCK for science teaching consisting of five components: (a) the orientation toward teaching science, (b) the knowledge of science curriculum, (c) the knowledge of students' understanding, (d) the knowledge of assessment, and (e) the knowledge and belief in the instructional strategies to teach science. Teachers could have the orientation toward teaching science served as an assisting role to support students' abilities. Both subject teachers seemed to focus on giving lectures. Their efforts to improve students' exploration methods and abilities were not expressed enough in their real classes and they found that students struggled to understand Mendelian genetics. Therefore, they should have explained them in an easier way and worked harder to make their students understood accurately and applied basic and advanced concepts of Mendelian genetics. They found students' preconception and misconception regarding Mendelian genetics and wished to enhance their learning effects by various teaching strategies such as correcting misconception, adding the history of science and simply assessing students' affirmative domains. It was also found that factors influenced to form PCK regarding Mendelian genetics by both teachers were as follows: teacher's personality and endeavor, textbooks and guidance books, schools and their circumstances, teaching experience, experience as a learner, interaction with their colleagues, and university curriculum. Both teachers said that it was important for teachers to make every efforts to give better classes.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.313-323
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• 2009

Diffusion-weighted imaging (DWI) has been demonstrated to be a practical method for the diagnosis of various brain diseases such as acute infarction, brain tumor, and white matter disease. In this study, we used two techniques to examine the average signal intensity (SI) and apparent diffusion coefficient (ADC) of the brains of patients who ranged in age from 10 to 60 years. Our results indicated that the average SI was the highest in amygdala (as derived from DWI), whereas that in the cerebrospinal fluid was the lowest. The average ADC was the highest in the cerebrospinal fluid, whereas the lowest measurement was derived from the pons. The average SI and ADC were higher in $T_2^*$-DW-EPI than in FLAIR-DW-EPI. The higher the b-value, the smaller the average difference in both imaging techniques; the lower the b-value, the greater the average difference. Also, comparative analysis of the brains of patients who had experienced cerebral infarction showed no distinct lesion in the general MR image over time. However, there was a high SI in apparent weighted images. Analysis of other brain diseases (e.g., bleeding, acute, subacute, chronic infarction) indicated SI variance in accordance with characteristics of the two techniques. The higher the SI, the lower the ADC. Taken together, the value of SI and ADC in accordance with frequently occurring areas and various brain disease varies based on the b-value and imaging technique. Because they provide additional useful information in the diagnosis and treatment of patients with various brain diseases through signal recognition, the proper imaging technique and b-value are important for the detection and interpretation of subacute stroke and other brain diseases.

• Asia pacific journal of information systems
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• v.17 no.2
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• pp.49-81
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• 2007

Research in the IS (Information Systems) outsourcing has focused on the importance of legal contracts and partnerships between vendors and clients. Without detailed legal contracts, there is no guarantee that an outsourcing vendor would not indulge in self-serving behavior. In addition, partnerships can supplement legal contracts in managing the relationship between clients and vendors legal contracts by itself cannot deal with all the complexity and ambiguity involved with IS outsourcing relationships. In this paper, we introduce a psychological contract (between client and vendor) as an important variable for IS outsourcing success. A psychological contract refers to individual's mental beliefs about his or her mutual obligations in a contractual relationship (Rousseau, 1995). A psychological contract emerges when one party believes that a promise of future returns has been made, a contribution has been given, and thus, an obligation has been created to provide future benefits (Rousseau, 1989). An employmentpsychological contract, which is a widespread concept in psychology, refers to employer and employee expectations of the employment relationship, i.e. mutual obligations, values, expectations and aspirations that operate over and above the formal contract of employment (Smithson and Lewis, 2003). Similar to the psychological contract between an employer and employee, IS outsourcing involves a contract and a set of mutual obligations between client and vendor (Ho et al., 2003). Given the lack of prior research on psychological contracts in the IS outsourcing context, we extend such studies and give insights through investigating the role of psychological contracts between client and vendor. Psychological contract theory offers highly relevant and sound theoretical lens for studying IS outsourcing management because of its six distinctive principles: (1) it focuses on mutual (rather than one-sided) obligations between contractual parties, (2) it's more comprehensive than the concept of legal contract, (3) it's an individual-level construct, (4) it changes over time, (5) it affects organizational behaviors, and (6) it's susceptible to organizational factors (Koh et al., 2004; Rousseau, 1996; Coyle-Shapiro, 2000). The aim of this paper is to put the concept, psychological contract commitment (PCC), under the spotlight, by finding out its mediating effects between legal contracts/partnerships and IS outsourcing success. Our interest is in the psychological contract commitment (PCC) or commitment to psychological contracts, which is the extent to which a partner consistently and deeply concerns with what the counter-party believes as obligations during the IS project. The basic premise for the hypothesized relationship between PCC and success is that for outsourcing success, client and vendor should continually commit to mutual obligations in which both parties believe, rather than to only explicit obligations. The psychological contract commitment playsa pivotal role in evaluating a counter-party because it reflects what one party really expects from the other. If one party consistently shows high commitment to psychological contracts, the other party would evaluate it positively. This will increase positive reciprocation efforts of the other party, thus leading to successful outsourcing outcomes (McNeeley and Meglino, 1994). We have used matched sample data for this research. We have collected three responses from each set of a client and a vendor firm: a project manager of the client firm, a project member from the vendor firm with whom the project manager cooperated, and an end-user of the client company who actually used the outsourced information systems. Special caution was given to the data collection process to avoid any bias in responses. We first sent three types of questionnaires (A, Band C) to each project manager of the client firm, asking him/her to answer the first type of questionnaires (A).