Determinants of Locational Choice of Manufacturing Firms in the Seoul Region: An Analysis of Survey Results

This paper as part of the World Bank research project(RPO 672-91), "An Evaluation of Industrial Location Policies for Urban Deconcentration," presents the results from a survey of establishments conducted to study the locational choice of manufacturing firms in the Seoul region. Using the annual manufacturing surveys compiled by the Korean National Bureau of Statistics(NBS), the location patterns of employment and their changes were extensively analyzed in another paper (Lee, 1985a); this analysis, performed in terms of births, deaths, and relocation of firms, revealed a high degree of employment location dynamics and strong evidence of the spatial decentralization of manufacturing employment in the Seoul region, as briefly described in the next section. In order to explain these observed location patterns, a survey of manufacturing establishments was conducted in the Seoul region using the 1981 NBS manufacturing survey as the sample base. The survey questionnaire was designed to take about one hour to complete and did not require the respondents to look up their accounting books; still the questionnaire contained a large amount of information with over 400 computer readable variables. This paper will present most salient aspects of the survey results which provide the basis for understanding the changing location patterns of manufacturing employment summarized in the next section. The analysis in this paper is descriptive but the underlying theoretical framework is that of the previous studies on Bogota, Colombia (Lee, 1981; 1982a). After a brief overview of the manufacturing employment location patterns in the region, the sampling strategy is briefly described and the sample outcome is summarized. In the rest of the paper, the survey results are presented in three categories of findings: (1) Esta· blishment characteristics, (2) site characteristics, and (3) the factors considered to be important for the respondent's locational choice. These results are contrasted and compared among the sample establishments by establishment size, firm type(i.e., mature firms, births, and movers), and industries studied. (1) The underlying theoretical framework is that a firm of particular type will locate at a site with particular attributes in such a way that the selected location is optimal to the firm in an urban area, in terms of profits, costs, or some other criteria (Lee, 1982a). The establishment characteristics include type of products, production process, building characteristics, lot size, floor space, and skill composition of workers. The site attributes include proximities to product markets and input suppliers, commuting distance, transport modes, the quality and availability of public utilities and municipal services. The survey questionn-aire prepared for this study contains a section on policy instruments used by the Korean government intended to ,influence firms' locational choice, which was absent in the Bogota study. The results on the effectiveness of policy instruments are reported in Lee(1985a)

Multiphasic analysis of whole exome sequencing data identifies a novel mutation of ACTG1 in a nonsyndromic hearing loss family

BACKGROUND: The genetic heterogeneity of sensorineural hearing loss is a major hurdle to the efficient discovery of disease-causing genes. We designed a multiphasic analysis of copy number variation (CNV), linkage, and single nucleotide variation (SNV) of whole exome sequencing (WES) data for the efficient discovery of mutations causing nonsyndromic hearing loss (NSHL). RESULTS: From WES data, we identified five distinct CNV loci from a NSHL family, but they were not co-segregated among patients. Linkage analysis based on SNVs identified six candidate loci (logarithm of odds [LOD] >1.5). We selected 15 SNVs that co-segregated with NSHL in the family, which were located in six linkage candidate loci. Finally, the novel variant p.M305T in ACTG1 (DFNA20/26) was selected as a disease-causing variant. CONCLUSIONS: Here, we present a multiphasic CNV, linkage, and SNV analysis of WES data for the identification of a candidate mutation causing NSHL. Our stepwise, multiphasic approach enabled us to expedite the discovery of disease-causing variants from a large number of patient variants

Clinical Significance of Extraluminal Compressions according to the Site of the Duodenum

Background/Aims Differentiating extraluminal compressions from true subepithelial tumors in the duodenum by endoscopy alone is difficult. Endoscopic ultrasonography (EUS) is one of the most useful diagnostic modalities for this purpose. Extraluminal compression in the duodenum is occasionally observed, but its clinical significance has not been reported. Therefore, the aim of this study was to evaluate the clinical significance of extraluminal compression in the duodenum according to lesion location.Materials and Methods We retrospectively evaluated 22 patients diagnosed as having extraluminal compression in the duodenum based on EUS findings between January 2006 and December 2017. Some patients underwent abdominal computed tomography for accurate diagnosis. Results The location of the extraluminal compression was the duodenal bulb in 10 cases, the superior duodenal angle in 10 cases, and the second portion of the duodenum in 2 cases. Of the 22 cases, 12 were caused by normal structures, including vessels, the right kidney, the gallbladder, and the pancreas, and 10 were caused by pathological lesions, including the hepatic cyst, remnant cystic duct and dilated common bile duct after cholecystectomy; gallstones, gallbladder polyps, remnant cystic duct cancer, and pseudomyxoma peritoneii. The anterior wall of the duodenum was the most frequent location of extraluminal compression. However, the lesions in the anterior wall of the duodenal bulb and superior duodenal angle showed a high frequency of pathologic lesions, including malignancy. Conclusions If the extraluminal compression is found in the anterior wall of the duodenum, EUS is needed because of the high frequency of pathological lesions

Specific Radius Change of Quantum Dot inside the Lipid Bilayer by Charge Effect of Lipid Head-Group

We studied the quantum dot-liposome complex (QLC), which is the giant unilamellar vesicle with quantum dots (QDs) incorporated in its lipid bilayer. A spin coating method in conjunction with the electroformation technique yielded vesicles with highly homogeneous unilamellar structure. We observed QD size dependence of the QLC formation: QLCs form with blue, green and yellow-emission QD (core radius ~1.05 nm, 1.25 nm and 1.65 nm) but not with red-emission QD (core radius ~2.5 nm). In order to explain this size dependence, we made a simple model explaining the QD size effect on QLC formation in terms of the molecular packing parameter and the lipid conformational change. This model predicts that QDs below a certain critical size (radius ≈ 1.8 nm) can stably reside in a lipid bilayer of 4 - 5 nm in thickness for Egg-PC lipids. This is consistent with our previous experimental results. In the case of red-emission QD, QD-aggregations are only observed on the fluorescent microscopy instead of QLC. We expected that the reduction of packing parameter (P) would lead to the change of specific QD radius. This prediction could be verified by our experimental observation of the shift of the specific QD size by mixing DOPG

Toxicity and Toxin Composition of Microcystis aeruginosa from Wangsong Reservoir

Objective: The increasing world population, resulting in increased anthropogenic water pollution, is negatively impacting the limited available water resources. In South Korea, this similarly affects the water quality of reservoirs. As water is a basic necessity for life, water quality monitoring is essential but typically does not include toxicity testing. However, as toxic bloom event frequencies are increasing, this previously neglected aspect becomes pertinent. Therefore, in the present study, the toxin composition and toxicity of a Microcystis aeruginosa strain isolated from a persistent bloom in lake Wangsong, South Korea, was investigated. Methods: A combination of bioassays and chemical analysis was used for this purpose. The bioassay species included terrestrial and aquatic plants, an alga, a rotifer, a tubificid annelid, and crustaceans, representing various trophic levels. Results: The strain was found to produce microcystin-LR, -RR, and YR, as well as β-N-methylamino-L-alanine. The bioassays indicated that the primary producers were less sensitive to the crude extract. Conclusion: The presence or absence of a visible cyanobacterial bloom is also not an indication of the toxins that may be present in the afflicted waters, and thus does not predict exposure risk. Similarly, the presence and absence of toxins and mixtures thereof do not indicate the ecological effect. Therefore, it would be advantages to include toxicity testing into routine water testing regimes to better understand the impact of harmful algal blooms.Peer reviewe