• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.25 no.2
• /
• pp.6-14
• /
• 1980

One of the physiological disease, sudden wiliting of Yushin variety suggested that low sunlight, excessive nitrogen application, and highly reduced soil condions either singly or combined, might be possible causes of the disorder. Some visual symptom of sudden wilting are discoloration of leaves, development of nodal roots above the soil surface, total root rot, and lodging. Those observations led to the hypothesis that suffocation of root tissues was a direct cause of the wilting. The oxygen transport characteristics of Yushin, IR262 and Tongil were examined by two methods. First, Soil-cultured plants of the three varieties were subjected to paraffin treatment to decrease the oxygen supply from the air to root tissues through the soil-water system, liquid paraffin was applied to the water surface in the pots at panicle formation stage. In this experiment, sudden wilting was observed of Yushin and IR262 at about a week after the treatment, but Tongil remained green and healthy. Wilting-resistant variety Tongil had higher oxygen release, whereas the susceptible Yushin and IR262 had lower oxygen release. Second, the number and size of the air spaces in each internode were investigated in the 5th internode from the top, all three varieties have a similar number of air spaces, although the air spaces of Thongil were larger. In the 4th internode, Tongil had plenty air spaces, Yushin and one of the Yushin's parents IR262 had scanty or none. The observations indicated that the ability of Yushin and IR262 for oxygen transport is very limited compared with that of Tongil. The limited oxygen supply due to poor development of air space in internode of rice plants may cause suffocation of root tissues, weaken metabolic activity of the tissues, and induce root rot, subsequently inducing sudden wilting and lodging under unfavorable weather, soil and cultural conditions.

• Economic and Environmental Geology
• /
• v.49 no.1
• /
• pp.1-11
• /
• 2016

Chrysotile is well known as a fibrous mineral in serpentinite by the previous studies in S. Korea. Previous studies in other countries showed that antigorite also occurred as asbestiform and harmful to humans. Therefore, the objective of this study was to investigate types and characteristics of fibrous serpentine minerals occurred in serpentinite in Hongseong, Chungnam and Gapyeong, Gyeonggi in S. Korea. XRD, SEM-EDS, PLM and EPMA mapping analyses were used to examine the occurrence and formation mechanism of serpentine minerals. Serpentinization partially occurred in amphibole-schist and calc-schist at two study sites, Hongseong, Chungnam and Gapyeong, Gyeonggi, respectively. Both chrysotile and antigorite occurred as a fibrous mineral at Hongseong site, but chrysotile occurred as a fibrous mineral at Gapyeong site. Based on PLM analysis with dispersion staining, the chrysotile was observed horizontally magenta and vertically blue colors. The antigorite appeared as horizontally gold to golden magenta and vertically blue magenta colors under central stop dispersion staining objective(DSO). PLM and SEM analyses showed the fibrous minerals were formed from plate form of serpentine minerals or by hydrothermal alternation of primary minerals. The EPMA mapping showed that Mg contents in chrysotile is relatively higher than that in antigorite while Si and O contents in antigorite is higher than them in chrysotile. However, more studies are necessary to know the exact variation in chemical composition of chrysotile and antigorite. These results indicate that even though asbestiform antigorite found associated with asbestos chrysotile in serpentinites, the fibrous antigorite can be distinguished from chrysotile by different dispersion staining colors.

• Journal of Nutrition and Health
• /
• v.50 no.5
• /
• pp.415-425
• /
• 2017

Purpose: Many studies have suggested that neuronal cells protect against oxidative stress-induced apoptotic cell death by polyphenolic compounds. We investigated the neuroprotective effects and the mechanism of action of Momordica charantia ethanol extract (MCE) against $H_2O_2-induced$ cell death of human neuroblastoma SK-N-MC cells. Methods: The antioxidant activity of MCE was measured by the quantity of total phenolic acid compounds (TPC), quantity of total flavonoid compounds (TFC), and 2,2-Diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging activity. Cytotoxicity and cell viability were determined by CCK-8 assay. The formation of reactive oxygen species (ROS) was measured using 2,7-dichlorofluorescein diacetate (DCF-DA) assay. Antioxidant enzyme (SOD-1,2 and GPx-1) expression was determined by real-time PCR. Mitogen-activated protein kinases (MAPK) pathway and apoptosis signal expression was measured by Western blotting. Results: The TPC and TFC quantities of MCE were 28.51 mg gallic acid equivalents/extract g and 3.95 mg catechin equivalents/extract g, respectively. The $IC_{50}$ value for DPPH radical scavenging activity was $506.95{\mu}g/ml$ for MCE. Pre-treatment with MCE showed protective effects against $H_2O_2-induced$ cell death and inhibited ROS generation by oxidative stress. SOD-1,2 and GPx-1 mRNA expression was recovered by pre-treatment with MCE compared with the presence of $H_2O_2$. Pre-treatment with MCE inhibited phosphorylation of p38 and the JNK pathway and down-regulated cleaved caspase-3 and cleaved PARP by $H_2O_2$. Conclusion: The neuroprotective effects of MCE in terms of recovery of antioxidant enzyme gene expression, down-regulation of MAPK pathways, and inhibition apoptosis is associated with reduced oxidative stress in SK-N-MC cells.

• Economic and Environmental Geology
• /
• v.52 no.5
• /
• pp.395-407
• /
• 2019

The duplex system has been considered as an important slip-transfer mechanism to evaluate the evolution of orogenic belts. Duplexes are generally found in the hinterland portion of fold-thrust belts and accommodate large amounts of total shortening. Thus, understanding its geometric and kinematic evolution can give information to evaluate the evolution of the entire orogenic belt. Duplexes are recognized as closed-loop thrust traces on map view, indicating higher connectivity than imbricate fans. As originally defined, a duplex is an array of thrust horses which are surrounded by thrust faults including the floor and roof thrusts, and imbricate faults between them. Duplexes can accommodate regional layer-parallel shortening and transfer slip from a floor thrust to a roof thrust. However, an imbricate fault is not the only mean for layer-parallel shortening (LPS) and displacement transfer within duplexes. LPS cleavages and detachment folds can also play the same role. From this aspect, a duplex can be divided into three types; 1) fault duplex, 2) cleavage duplex and 3) fold duplex. Fault duplex can further be subdivided into the Boyer-type duplex, which was firstly designed duplex system in the 1980s that widely applied most of the major fold-thrust belts in the world, and connecting splay duplex, which has different time order in the emplacement of horses from those of the Boyer-type. On the contrary, the cleavage and fold duplexes are newly defined types based on some selected examples. In the Korean Peninsula, the Yeongwol area, the western part of the Taebaeksan Zone of the Okcheon Belt, gives an excellent natural laboratory to study the structural geometry and kinematics of the closed-loops by thrust fault traces in terms of a duplex system. In the previous study, the Yeongwol thrust system was interpreted by alternative duplex models; a Boyer-type hinterland-dipping duplex vs. a combination of major imbricate thrusts and their connecting splays. Although the high angled beds and thrusts as well as different stratigraphic packages within the horses of the Yeongwol duplex system may prefer the later complicate model, currently, we cannot choose one simple answer between the models because of the lack of direct field evidence and time information. Therefore, further researches on the structural field investigations and geochronological analyses in the Yeongwol and adjacent areas should be carried out to test the possibility of applying the fold and cleavage duplex models to the Yeongwol thrust system, and it will eventually provide clues to solve the enigma of formation and its evolution of the Okcheon Belt.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.41 no.4
• /
• pp.341-350
• /
• 2015

Skin carrys out protective role against harmful outer environment assaults including ultraviolet radiation, heavy metals and oxides. Especially, ultraviolet-B (UVB) light causes inflammatory reactions in skin such as sun burn and erythma and stimulates melanin pigmentation. Furthermore, the influx of UVB into skin cells causes DNA damage in keratinocytes and dermal fibroblasts, inhibition of extracellular matrix (ECM) synthesis which leads to a decrease in elasticity of skin and wrinkle formation. It also damages dermal connective tissue and disrupts the skin barrier function. Prolonged exposure of human skin to UVB light is well known to trigger severe skin lesions such as cell death and carcinogenesis. Haloarcula vallismortis is a halophilic microorganism isolated from the Dead Sea, Its growth characteristics have not been studied in detail yet. It generally grows at salinity more than 10%, but the actual growth salinity usually ranges between 20 to 25%. Because H. vallismortis is found mainly in saltern or salt lakes, there could exist defense mechanisms against strong sunlight. One of them is generation of additional ATP using halorhodopsin which absorbs photons and produces energy by potential difference formed by opening the chloride ion channel. It often shows a color of pink or red because of their high content of carotenoid pigments and it is considered to act as a defense mechanism against intense UV irradiation. In this study, the anti-inflammatory effect of the halophilic microorganism, H. vallismortis, extract was investigated. It was found that H. vallismortis extract had protective effect on DNA damage induced by UV irradiation. These results suggest that the extract of halophilic bacterium, H. vallismortis could be used as a bio-sunscreen or natural sunscreen which ameliorate the harmful effects of UV light with its anti-inflammatory and DNA protective properties.

• Cross-Cultural Studies
• /
• v.52
• /
• pp.277-312
• /
• 2018

First-order cybernetics during the 1940s and 1950s aimed for control of an observed system, while second-order cybernetics during the mid-1970s aspired to address the mechanism of an observing system. The former pursues an objective, subjectless, approach to a system, whereas the latter prefers a subjective, personal approach to a system. Second-order observation must be noted since a human observer is a living system that has its unique cognition. Maturana and Varela place the autopoiesis of this biological system at the core of second-order cybernetics. They contend that an autpoietic system maintains, transforms and produces itself. Technoscientific recreation of biological autopoiesis opens up to a new step in cybernetics: what I describe as third-order cybernetics. The formation of technoscientific autopoiesis overlaps with the Fourth Industrial Revolution or what Erik Brynjolfsson and Andrew McAfee call the Second Machine Age. It leads to a radical shift from human centrism to posthumanity whereby humanity is mechanized, and machinery is biologized. In two versions of the novel Demon Seed, American novelist Dean Koontz explores the significance of technoscientific autopoiesis. The 1973 version dramatizes two kinds of observers: the technophobic human observer and the technology-friendly machine observer Proteus. As the story concludes, the former dominates the latter with the result that an anthropocentric position still works. The 1997 version, however, reveals the victory of the techno-friendly narrator Proteus over the anthropocentric narrator. Losing his narrational position, the technophobic human narrator of the story disappears. In the 1997 version, Proteus becomes the subject of desire in luring divorcee Susan. He longs to flaunt his male egomaniac. His achievement of male identity is a sign of technological autopoiesis characteristic of third-order cybernetics. To display self-producing capabilities integral to the autonomy of machinery, Koontz's novel demonstrates that Proteus manipulates Susan's egg to produce a human-machine mixture. Koontz's demon child, problematically enough, implicates the future of eugenics in an era of technological autopoiesis. Proteus creates a crossbreed of humanity and machinery to engineer a perfect body and mind. He fixes incurable or intractable diseases through genetic modifications. Proteus transfers a vast amount of digital information to his offspring's brain, which enables the demon child to achieve state-of-the-art intelligence. His technological editing of human genes and consciousness leads to digital standardization through unanimous spread of the best qualities of humanity. He gathers distinguished human genes and mental status much like collecting luxury brands. Accordingly, Proteus's child-making project ultimately moves towards technologically-controlled eugenics. Pointedly, it disturbs the classical ideal of liberal humanism celebrating a human being as the master of his or her nature.

• Korean Journal of Mineralogy and Petrology
• /
• v.36 no.4
• /
• pp.303-312
• /
• 2023

The determination of the oxidation states of metal elements in manganese nodules sheds light on the understanding of the formation mechanism of nodules, providing insights into the paleo-environmental conditions such as the redox potential of the aqueous system. This study aims to reveal the oxidation states and chemical bonding of manganese in the natural polymetallic nodules, utilizing conventional X-ray photoelectron spectroscopy (XPS). Specifically, shallow manganese nodules from the Siberian Arctic Sea, effectively recording mineralogical variations, were used in this study. Detailed analysis of XPS Mn 2p spectra showed changes in the manganese oxidation state from the center to the outer parts of the nodules. The central part of the nodules showed a higher Mn⁴⁺ content, approximately 67.9%, while the outermost part showed about 63% of Mn⁴⁺ due to an increase in the Mn³⁺+Mn²⁺. The decrease in the Mn oxidation state with the growth is consistent with the previously reported mineralogical variations from todorokite to birnessite with growth. Additionally, the O 1s spectra presented a predominance of Mn-O-H bonds in the outer layers compared to the center, suggesting hydration by water in the layered manganates of outer layers. The results of this study demonstrate that XPS can be directly applied to understand changes in paleo-environmental conditions such as the redox states during the growth of manganese nodules. Finally, future studies using high-resolution synchrotron-based XPS experiments could achieve details in oxidation states of manganese and trace metal elements.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.19 no.3
• /
• pp.123-138
• /
• 2024

Experiential social entrepreneurship education offers participants opportunities for active engagement in social entrepreneurial activities. Highlighting the significance of psychosocial experiences within the program, this study examines work meaningfulness discovered in this process as the antecedent to forming social entrepreneurial intention. Furthermore, drawing on social cognitive career theory that emphasizes the role of agency in career decisions, we propose social entrepreneurial self-efficacy as the underlying mechanism and social class as the moderating factor in the relationship between work meaningfulness and social entrepreneurial intention formation. The propositions were tested with a two-wave survey dataset collected among 145 university students taking part in an experiential social entrepreneurship program in South Korea. Our results indicate that work meaningfulness positively affects social entrepreneurial self-efficacy, which subsequently promotes social entrepreneurial intention. Moreover, when participants' social class, measured by either household income or perceived rank, is lower, the positive effect of work meaningfulness on social entrepreneurial self-efficacy as well as intention is amplified. Theoretically, these findings shed light on the crucial role of work meaningfulness in strengthening potential entrepreneurs' agency in the domain of social entrepreneurship, particularly for those from lower classes. Practically, we provide guidelines for designing an inclusive experiential social entrepreneurship program that allows participants to find meaningfulness by realizing their strengths and justifying their prosocial contribution.

• Korean Journal of Psychosomatic Medicine
• /
• v.4 no.2
• /
• pp.269-276
• /
• 1996

A theroretical study was made on the psychodynamism of somatoform disorder. Somatoform disorder is caused by a defense mechanism of somatization. Somatization is the tendency to react to stimuli(drives, defenses, and conflict between them) physically rather than psychically(Moore, 1990). Ford(1983) said it is a way of life, and Dunbar(1954) said it is the shift of psychic energy toward expression in somatic symptoms. As used by Max Shur(1955), somatization links symptom formation to the regression that may occur in response to acute and chronic conflict. In the neurotic individual psychic conflict often provokes regressive phenomena that may include somatic manifestations characteristic of an earlier developmental phase. Schur calls this resomatization. Pain is the most common example of a somatization reaction to conflict. The pain has an unconscious significance derived from childhood experiences. It is used to win love, to punish misdeeds, as well as a means to amend. Among all pains, chest pain has a special meaning. Generally speaking, 'I have pain in my chest' is about the same as 'I have pain in my mind'. The chest represent the mind, and the mind reminds us about the heart. So we have a high tendency to recognize mental pain as cardiac pain. Kellner(1990) said rage and hostility, especially repressed hostility, are important factors in somatization. In 'Psychoanalytic Observation on Cardiac Pain', psychoanalyst Bacon(1953) presented clinical cases of patients who complained of cardiac pain in a psychoanalytic session that spread from the left side of their chests down their left arms. The pain was from rage and fear which came after their desire to be loved was frustrated by the analyet. She said desires related to cardiac pain were dependency needs and aggressions. Empatic relationship and therapeutic alliances are indispensable to psychotherapy in somatoform disorder. The beginning of therapy is to discover a precipitating event from the time their symptoms have started and to help the patient understand a relation between the symptom and precipitating event. Its remedial process is to find and interpret a intrapsychic conflict shown through the symptoms of the patient. Three cases of somatoform disorder patients treated based on this therapeutic method were introduced. The firt patient, Mr. H, had been suffering from hysterical aphasia with repressed rage as ie psychodynamic cause. An interpretation related to the precipitating event was given by written communication, and he recovered from his aphasia after 3 days of the session. The second patient was a dentist in a cardiac neurosis with agitation and hypochondriasis, whose psychodynamism was caused by a fear that he might lose his father's love. His symptom was also interpreted in relation to the precipitating event. It showed the patient a child-within afraid of losing his father's love. His condition improved after getting a didactic interpretation which told him, to be master of himself, The third patient was a lady transferred from the deparment of internal medicine. She had a frequent and violent fit of chest pains, whose psychodynamic cause was separation anxiety and a rage due to the frustration of dependency needs. Her symptom vanished dramatically when she wore a holler EKG monitor and did not occur during monitoring. By this experience she found her symptom was a psychogenic one, and a therapeutic alliance was formed. later in reguar psychotherapy sessions, she was told the relaton between symptoms and precipitating events. Through this she understood that her separation anxiety was connected to the symptom and she became less terrifide when it occurred. Now she can travel abroad and take well part in social activities.

• Journal of fish pathology
• /
• v.1 no.1
• /
• pp.5-30
• /
• 1988

This is a comprehensive study for considering the effective treatment and control program of bacterial disease occurring in common carp, israel carp, color carp, crucian carp, eel and tilapia by clarifying the causes, mechanism of infection and onset and the diagnostic criteria. As a first step, the authors investigated the external views, gross and histopathologic findings of diseased fish using 450 infected fishes obtained from various farmer of Korea. This infection was characterized by hyperemia, hemorrhage and swelling of body surface and fins, congestion of liver, spleen, kidney, inflammation of intestine, hemorrhagic inflammation of various tissues, and necrosis and ulcer of various tissues were accompanied in serious cases. Bacteriologically, Aeromonas hydrophila and Edwardsiella tarda were isoiated from these fishes. Particularly in the regular check on 222 eels, 177 strains were isolated as 29.94% of Aeromonas hydrophila, 48.58% of Edwardsiella tarda and 21.47% of Flexibacter columnaris. Hexibacter columnaris was isolated from corroded gill of eels. The identical disease was occurred by innoculating the isolated Aeromonas hydrophila and Edwardsiella tarda and the identical strains were isolated from infected experimental fishes. The eels which were diagnosed Aeromonas disease from Kwangju, Pusan accompanied hemorrhage, swelling of body surface and fins, inflammation of stomach and intestine containing mucous fluids mixed with the pathogens. Color carp and crucian carp which were innoculated with the isolated 5 strins of Aeromomas hydrorphil died within 3 or 4 days accompanying with the characteristics of Aeromonas disease. Edward disease was characterized by abscesses of body surface, pus formation with concentration on phagocytes. The size of absecsses increased with progression elf disease. There were also various abscesses at internal organ and white nodules appeared in kidney. Histologically, various progressive granuloma were examined without inflammation of intestine. Columnaris disease of eels showed no hemorrhage except slight white body color. In autopsy, most of internal organs appeared normal and there were no septic odors. The only character was corrosion of gills. In order to treat these bacterial diseases, infected fishes must bathe in 20ppm chloramphenicol or kanamycin solution for 1 hour. Besides, medication program in oral ingestion of 75mg/kg chloramphenicol per day continuing for 5 to 7 days. After injecting the formalin treated Aermonas hydrophila antigen into carp, relatively high agglutination titer showed between 3 weeks and 6 weeks. Though this titer decreased from that time, it was continued for 18 weeks. In the case of injecting the formalin treated Edwardsiella tarda antigen into tilapia, the titer also increased. But tilapia which were immersed in the suspension fluid of the formalin treated Edwardsiella tarda showed no increase of the titer.