South Korean Media System: Toward a Democratization Model

Translated from the published article in Communication Theories vol. 6 (No.1): 144-190, 2010 with permission from the Korean Society for Journalism and Communication Studies.From a perspective of the media systems approach, we attempt to provide a media system model that accounts for the characteristics of the relationship between political and media systems in the democratization process of Korean society. Using the model, we explore the possibility by which media system has set the limit on the directions of political democratization. The notion of political parallelism is employed to characterize the historical changes of the role of the news media in function of public spheres in relation to political system. The Korean way of political parallelism accounts for the process by which mainstream newspapers and broadcasters have influenced political parties and civil society. The implications are discussed in terms of the role of media system in democratization

Value recognition and eating patterns of Kimchi in female middle school students and their mothers

This study analyzed Kimchi eating culture in 178 households with female middle school children located in Incheon and Seosan areas, investigated the Kimchi eating patterns of female middle school students, and also analyzed the differences in value recognition for Kimchi between mothers and their female middle school students. Results showed that 23.0% of subject households answered eat Kimchi at every meal and the main reason for eating Kimchi in most households was good for taste. Most households made their own Kimchi, and only 12.3% of households bought Kimchi. Subject households preferred hot and spicy taste (34.8%) and pleasing taste (20.2%), and 44.4% of middle school children answered as eating Kimchi at every meal, and the source for information on Kimchi was home in 51.6% and mass media in 33.7%, suggesting the lack of school education. Both mothers and their female middle school students placed high value on Kimchi for its nutritional aspect and on Kimchi from the market for its convenience. Mothers showed significantly higher value (p<0.05) on the storage aspect of Kimchi compared to their middle school students, and female middle school students showed significantly higher value (p<0.05) on the value recognition for Kimchi as an international food compared to their mothers. Also, the value for hot pepper powder was high among other additional ingredients, and both mothers and middle school students had high values for Kimchi stew among other food dishes using Kimchi, and middle school students showed higher values (p<0.001) on foreign dishes using Kimchi such as Kimchi pizza and Kimchi spaghetti compared to the mothers group. Therefore, based on these results, the development of educational programs on Kimchi is needed not only at home but also at schools, by re-emphasizing the importance of value recognition for KImchi in our food culture

Recurrent Lower Gastrointestinal Bleeding from Congenital Arteriovenous Malformation in the Terminal Ileum Mimicking Intestinal Varicosis: A Case Report

We report on an exceptional vascular cause of gastrointestinal hemorrhage. A 30-yr-old man was admitted because of recurrent hematochezia. Colonoscopy showed circumferential, erythematous, and nodular vascular distensions with hematocystic spots in the terminal ileum resembling varicosis and subsequent computed tomography with 3-dimensional angiographic reconstruction revealed a vascular architecture around the terminal ileum. No other potential source of bleeding was identified. The patient was treated by ileocecectomy and the final diagnosis was of an arteriovenous malformation confined to the terminal ileum. He has been followed-up without a further hemorrhagic episode

Crystal structure of Helicobacter pylori MinE, a cell division topological specificity factor

In Gram-negative bacteria, proper placement of the FtsZ ring, mediated by nucleoid occlusion and the activities of the dynamic oscillating Min proteins MinC, MinD and MinE, is required for correct positioning of the cell division septum. MinE is a topological specificity factor that counters the activity of MinCD division inhibitor at the mid-cell division site. Its structure consists of an anti-MinCD domain and a topology specificity domain (TSD). Previous NMR analysis of truncated Escherichia coli MinE showed that the TSD domain contains a long α-helix and two anti-parallel β-strands, which mediate formation of a homodimeric α/β structure. Here we report the crystal structure of full-length Helicobacter pylori MinE and redefine its TSD based on that structure. The N-terminal region of the TSD (residues 19–26), previously defined as part of the anti-MinCD domain, forms a β-strand (βA) and participates in TSD folding. In addition, H. pylori MinE forms a dimer through the interaction of anti-parallel βA-strands. Moreover, we observed serial dimer–dimer interactions within the crystal packing, resulting in the formation of a multimeric structure. We therefore redefine the functional domain of MinE and propose that a multimeric filamentous structure is formed through anti-parallel β-strand interactions

Protective Effect of Metformin on Gentamicin-Induced Vestibulotoxicity in Rat Primary Cell Culture

ObjectivesOne of the antidiabetic drugs, metformin, have shown that it prevented oxidative stress-induced death in several cell types through a mechanism involving the opening of the permeability transition pore and cytochrome c release. Thus, it is possible that the antioxidative effect of metformin can also serve as protection against gentamicin-induced cytotoxicity related to reactive oxygen species (ROS). The aim of this study was to examine the protective effect of metformin on gentamicin-induced vestibulotoxicity in primary cell culture derived from rat utricle.MethodsFor vestibular primary cell culture, rat utricles were dissected and incubated. Gentamicin-induced cytotoxicity was measured in both the auditory and vestibular cells. To examine the effects of metformin on gentamicin-induced cytotoxicity in the primary cell culture, the cells were pretreated with metformin at a concentration of 1 mM for 24 hours, and then exposed to 2.5 mM gentamicin for 48 hours. The intracellular ROS level was measured using a fluorescent dye, and also measured using a FACScan flow cytometer. Intracellular calcium levels in the vestibular cells were measured with calcium imaging using Fura-2 AM.ResultsVestibular cells were more sensitive to gentamicin-induced cytotoxicity than auditory hair cells. Metformin protects against gentamicin-induced cytotoxicity in vestibular cells. Metformin significantly reduced a gentamicin-induced increase in ROS, and also reduced an increase in intracellular calcium concentrations in gentamicin-induced cytotoxicity.ConclusionMetformin significantly reduced a gentamicin-induced increase in ROS, stabilized the intracellular calcium concentration, and inhibited gentamicin-induced apoptosis. Thus, Metformin showed protective effect on gentamicin-induced cytotoxicity in vestibular primary cell culture

Optimization and validation of the NeuroLux wireless optoelectronics system for optogenetics

Utilizing light and genetic engineering, optogenetics permits the manipulation of events within cells via light using the light-sensitive properties of single-component microbial opsins. Microbial opsins are activated by a light source, such as lasers, light-emitting diodes, and incandescent sources that deliver light to the region of interest either directly or indirectly, such as through fiberoptics. In classical in vivo optogenetics, the wiring of optic fibers necessitates tethering of animals by the optic fiber to the light source. The novel NeuroLux wireless optoelectronic system for optogenetics circumvents issues pertaining to classical optogenetics by utilizing near-field power transfer via magnetic coil antennae to power miniature, subdermal, and flexible optoelectronic implants, including an LED light sources. Furthermore, features of the NeuroLux system overcome issues posed by other wireless systems, including interference. This preliminary study sought to validate and optimize the novel NeuroLux system setup by stimulating the cornu ammonis 2 (CA2) region of the hippocampus in transgenic mice that express Cre recombinase from the vasopressin 1b receptor promoter. Following experimentation, distinct stimulation, indicated by quantified cFos expression, was noted in the CA2 region, thereby validating the use of the NeuroLux wireless optoelectronics system for future optogenetics studies

Severe Aortic Coarctation in a 75-Year-Old Woman: Total Simultaneous Repair of Aortic Coarctation and Severe Aortic Stenosis

Aortic coarctation is usually diagnosed and repaired in childhood and early adulthood. Survival of a patient with an uncorrected coarctation to more than 70 years of age is extremely unusual, and management strategies for these cases remain controversial. We present a case of a 75-year-old woman who was first diagnosed with aortic coarctation and severe aortic valve stenosis 5 years ago and who underwent a successful one-stage repair involving valve replacement and insertion of an extra-anatomical bypass graft from the ascending to the descending aorta

NMDA Receptor in Vasopressin 1b Neurons Is Not Required for Short-Term Social Memory, Object Memory or Aggression

This work is licensed under a Creative Commons Attribution 4.0 International License.The arginine vasopressin 1b receptor (Avpr1b) plays an important role in social behaviors including aggression, social learning and memory. Genetic removal of Avpr1b from mouse models results in deficits in aggression and short-term social recognition in adults. Avpr1b gene expression is highly enriched in the pyramidal neurons of the hippocampal cornu ammonis 2 (CA2) region. Activity of the hippocampal CA2 has been shown to be required for normal short-term social recognition and aggressive behaviors. Vasopressin acts to enhance synaptic responses of CA2 neurons through a NMDA-receptor dependent mechanism. Genetic removal of the obligatory subunit of the NMDA receptor (Grin1) within distinct hippocampal regions impairs non-social learning and memory. However, the question of a direct role for NMDA receptor activity in Avpr1b neurons to modulate social behavior remains unclear. To answer this question, we first created a novel transgenic mouse line with Cre recombinase knocked into the Avpr1b coding region to genetically target Avpr1b neurons. We confirmed this line has dense Cre expression throughout the dorsal and ventral CA2 regions of the hippocampus, along with scattered expression within the caudate-putamen and olfactory bulb (OB). Conditional removal of the NMDA receptor was achieved by crossing our line to an available floxed Grin1 line. The resulting mice were measured on a battery of social and memory behavioral tests. Surprisingly, we did not observe any differences between Avpr1b-Grin1 knockout mice and their wildtype siblings. We conclude that mice without typical NMDA receptor function in Avpr1b neurons can develop normal aggression as well as short-term social and object memory performance