• Journal of the Korean earth science society
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• v.43 no.1
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• pp.23-29
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• 2022

Although tropical cyclones with wind speeds weaker than 17 ms^-1 (weak tropical cyclones: WTCs) can cause significant damage, particularly over the Seoul metropolitan area, only a few studies have focused on WTC activity over South Korea. In this study, we found that WTC activity is likely associated with the Pacific Decadal Oscillation (PDO). During the negative phases of the PDO, landfall frequency of WTCs increased significantly compared to the positive phases at 95% confidence level. When related to the negative phases of the PDO, a positive relative vorticity anomaly is found in the northern sector of the western North Pacific while a negative relative vorticity anomaly and enhanced vertical wind shear prevail in the southern sector of the WNP. These factors are favorable for the northward shift of the genesis location of tropical cyclones on average, thereby reducing the total lifetime of WTCs. Moreover, a high-pressure anomaly over the Japanese islands would shift a tropical cyclone track westward in addition to the landfall location. Consequently, the effects of the topographical friction and the Yellow Sea Bottom Cold Water on a tropical cyclone may increase. These conditions could result in a weaker lifetime maximum intensity and landfall intensity, ultimately resulting in WTCs becoming more frequent over South Korea during the negative phases of the PDO.

• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.102-112
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• 2022

This study investigated dietary habits and intra- and inter-specific food resource partitioning of co-occurring walleye pollock (Gadus chalcogrammus) and Pacific cod (G. macrocephalus) from the waters off the north-eastern coast of South Korea using stomach contents and stable isotopes (δ¹³C and δ¹⁵N) analyses. Both species are mesopelagic carnivores that consumed mainly benthopelagic crustaceans, but teleosts were also abundant in the diet of Pacific cod. Non-metric multidimensional scaling (nMDS) ordination and permutational multivariate analysis of variance (PERMANOVA) of dietary data revealed significant intra- and inter-specific dietary differences, i.e., food resource partitioning. Nitrogen stable isotope values (δ¹⁵N) were similar between walleye pollock and Pacific cod, but carbon stable isotope values (δ¹³C) were significant different, suggesting different trophic positioning. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. Ontogenetic changes in diet compositions were evident. As walleye pollock, they preyed more upon carid shrimps and cephalopods, but no such trend was observed in the diets of Pacific cod. While stable isotope values indicated that large-sized specimens of both species were significantly enriched in ¹⁵N relative to smaller conspecifics thus supporting these data. Consequently, in this study, both methodologies, i.e., stomach contents and stable isotope analyses, provided evidence of inter- and/or intra-specific dietary segregations and trophic niche partitioning between co-occurring walleye pollock and Pacific cod off eastern Korean waters.

• Atmosphere
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• v.26 no.4
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• pp.577-598
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• 2016

Observational and numerical studies have been carried out to understand the cause and development processes of the heavy rainfall over the middle Korean Peninsula during 0300 LST-1500 LST 29 June 2011 (LST = UTC + 0900). The heavy rainfall event occurred as the synoptic-scale ridge extended from Western Pacific Subtropical High (WPSH) was maintained over East Asia. Observational analysis indicates that the heavy rainfall is mainly due to scattered convective systems, formed over the Yellow Sea, traveling northeastward across the middle peninsula without further organization into larger systems during 0300 LST-0800 LST, and mesoscale convective systems (MCSs) over the Yellow Sea, transformed into a squall line, traveling eastward during 0800 LST-1500 LST. Organization of convective systems into MCSs can be found over the area of mesoscale trough and convergence zone in the northern end of the low-level jet (LLJ) after 0600 LST. Both observational and numerical investigations indicate that a strong LLJ extended from the East China Sea to the Yellow Sea plays an essential role for the occurrence of heavy rainfall. The strong LLJ develops in between the WPSH and a pressure trough over eastern China. Numerical experiments indicate that the land-sea contrast of solar heating of surface and latent heating due to convective developments are the major factors for the development of the pressure trough in eastern China. Numerical study has also revealed that the mountainous terrain including the mountain complex in the northern Korean Peninsula contributes to the increase of rainfall amount in the middle part of the peninsula.

• Asia-Pacific Journal of Business
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• v.8 no.1
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• pp.45-65
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• 2017

This study which focused on factors and challenges affecting the decision-making of indigenous corn farmers ascertained the determinants that make farmers decide to engage in and continue corn farming activities in Paracelis, Mountain Province, in Northern Philippines. Determinants of decision and motivational factors of corn farmers were examined based on survey responses of 120 indigenous corn farmers by applying chi-square test analysis. Results showed that there were some decision and motivational factors that were significantly related to specific characteristics of corn farmers and there were also similarities of factors that affected the decision making of farmers in terms of engaging in and sustaining corn farming activities. Among the identified driving forces, financing capability and availability of land area were highly related with farm size and with a farmer's educational attainment. Knowledge or experience and interest in corn farming were also related with educational attainment. All the identified driving forces were found to be unrelated to farmers' age. The motivational factor identified as "personally satisfying" was found to be related with age, educational attainment and years in the farming business. Factors which affected a farmer's decision to sustain corn farming activities ("sustaining" factors) such as availability of different networks is highly related to educational attainment, years in the farming business and farm size while high market price of corn was the only "sustaining" factor linked to educational attainment. Based on these factors and cited problems in corn farming, recommendations were offered to address the issues raised by farmers.

• Strategy21
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• s.30
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• pp.63-98
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• 2012

Northeast Asia has a multi-layered security structure within which major economic and military powers both confront one another and cooperate at the same time. Major regional powers maintain mutually cooperative activities in the economic sphere while competing one another in order to secure a dominant position in the politico-military arena. The multifarious threats, posed by the North Korea's nuclear development, territorial disputes, and maritime demarcation line issues demonstrate that Northeast Asia suffers more from military conflicts and strifes than any other region in the world. Specifically, major maritime security threats include North Korea's nuclear proliferation and missile launching problems as well as military provocations nearby the Northern Limit Line(NLL) as witnessed in the Cheonan naval ship and Yeonpyong incidents. The ROK Navy has been supplementing its firm military readiness posture in consideration of North Korea's threats on the NLL. It has performed superb roles in defending the nation and establishing the Navy advanced and best picked. It also has been conducive to defend the nation from external military threats and invasion, secure the sea lanes of communications, and establish regional stability and world peace. In order to effectively cope with the strategic environment and future warfares, the ROK Navy needs to shift its military structure to one that is more information and technology intensive. In addition, it should consolidate the ROK-US alliance and extend military cooperative measures with neighboring countries in the Asia-Pacific region. Evolved steadily for the last 60 years, the ROK-US alliance format has contributed to peace and security on the Korean peninsula and in the Northeast Asian region. In conclusion, this manuscript contends that the ROK Navy should strive for the establishment of the following: (1) Construction of Jeju Naval Base; (2) Strategic Navy Equipped with War Deterrence Capabilities; (3) Korean-type of System of Systems; (4) Structure, Budget and Human Resources of the Naval Forces Similar to the Advanced Countries; and (5) Strategic Maritime Alliance and Alignment System as well as Domestic Governance Network for the Naval Families.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3931-3936
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• 2013

Background: Iran is a country with very high incidences of stomach cancer, especially in Northern parts. Here we assessed prognostic value of serum screening biomarkers among people >50 years old for early detection of precancerous lesions in a hot spot for gastric carcinoma in Guilan Province, North Iran. Methods: A cross-sectional population-based survey was conducted on 1,390 residents of Lashtenasha city with the mean age (SD) of 61.8 (9.02) years old (50.8% females) to assess the association of gastrin and the pepsinogen (PG) I/II ratio with premalignant gastric lesions. Blood samples were taken for CBC, blood group, and serologic exams (PGI, PGII, and gastrin 17) from each subject. Expert gastroenterologists performed upper GI endoscopy and ROC curves were generated to determine appropriate cutoff points. Results: Mean values of PGI, PGII, PGI/PGII and gastrin were significantly different between patients with and without atrophy or metaplasia (P<0.05). To diagnose atrophy and intestinal metaplasia, a significantly higher AUC was observed for the PGI/PGII ratio (70 and 72%, respectively) compared to the PGI (56, 55%), PGII (63, 64%) and gastrin (59, 61%) (all p<0.001). Conclusions: Biomarker tests such as the PGI/II ratio can be used in the screening and diagnosis of subjects at high gastric cancer risk in our region.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6093-6097
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• 2015

Background: HPV DNA testing has been recently introduced as an adjunct test to cytology in the follow-up of patients after treatment for cervical lesions using the loop electrosurgical excision procedure (LEEP). The aim of this study was to evaluate the role of HPV testing in the detection of persistent or recurrent disease after LEEP in patients with cervical epithelial lesions in northern Thailand. Materials and Methods: Patients who underwent LEEP as a treatment for histological low-grade (LSIL) or high-grade squamous intraepithelial lesion (HSIL) or worse at Chiang Mai University Hospital between June 2010 and May 2012 were included. Follow-ups were scheduled at 6-month intervals and continued for 2 years using co-testing (liquid-based cytology and Hybrid Capture 2 [HC2]) at 6 months and 24 months and liquid-based cytology alone at 12 and 18 months. Results: Of 98 patients included, the histological diagnoses for LEEP included LSIL in 16 patients, and HSIL or worse in 82 patients. The LEEP margin status was negative in 84 patients (85.7%). At follow-up, 10 patients (10.2%) had persistent/recurrent lesions; 4 among LSIL patients (25.0%) and 6 in the group with HSIL or worse (7.3%). Only 2 of 82 patients (2.4%) with HSIL or worse diagnoses had histological HSIL in the persistent/recurrent lesions. Using histologically confirmed LSIL as the threshold for the detection of persistent/recurrent disease, cytology had a higher sensitivity than HC2 (90.0% versus 70.0%). At the 6-month follow-up appointment, combined cytology and HC2 (co-testing) had a higher sensitivity in predicting persistent/recurrent disease (80.0%) compared with that of cytology alone (70.0%) and HC2 (50.0%). Conclusions: After LEEP with a negative surgical margin, the rate of persistent/recurrent lesions is low. The addition of HPV testing at the 6-month visit to the usual cytology schedule may be an effective approach in the follow-up after LEEP.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3057-3063
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• 2014

Background: Anaplastic lymphoma kinase (ALK) gene rearrangement in non-small cell lung cancer (NSCLC) has been intensively studied. The gold standard for ALK detection is FISH, but this is not routinely conducted in clinical practice, so that the IHC method has a role. The aim of this study was to identify the incidence of ALK rearrangement and risk or prognostic factors for ALK positivity using both of IHC and FISH methods. Materials and Methods: From January 2008 to December 2012, 267 completely resected NSCLC patients in Chiang Mai University Hospital were enrolled in this study. Clinical and pathological variables and outcomes of treatment were retrospectively reviewed. IHC and FISH were used to evaluate ALK rearrangement. Sensitivity and specificity of IHC were analyzed. Multivariable analysis was used to identify clinico-pathological correlations with positive results of IHC and clinical outcomes. Results: Twenty-two (8.2%) of 267 specimens were IHC-positive for ALK with intense cytoplasmic staining, whereas only 10 (3.8%) were FISH-positive. Sensitivity, specificity and the positive likelihood ratio with IHC were 80.0%, 94.9%, and 15.8 respectively. Age less than 55 years (RR 4.4, 95%CI 1.78-10.73, p value=0.001) and presence of visceral pleural invasion (VPI) (RR 2.9, 95%CI 1.21-6.78, p value =0.017) were identified as risk factors for ALK rearrangement with FISH. There were no statistically significant differences in other clinical and pathological variables. ALK rearrangement was not a prognostic factor for tumor recurrence or overall survival. Conclusions: The incidences of ALK positivity in completely resected NSCLCs in northern Thailand were 8.2% by IHC and 3.8% by FISH. IHC with mouse monoclonal, Ventana D5F3 antibody can be used as a screening tool before FISH method because of high specificity and high positive likelihood ratio. Age less than 55 years and VPI are risk factors for ALK positivity.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.53-57
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• 2016

Colorectal cancer is one of the most common cancers. Due to demographic changes, it is predicted that the incidence of this cancer will increase. Variations of its incidence rate among geographical areas are due to various contributing factors. Since there have been a lack of studies on this topic in our country, the present assessment of spatial patterns of colorectal cancer incidence in Iran was performed. In this ecological study, the new cases of colon cancer were extracted from Cancer Registry Center report of the Health Deputy of Iran in 2009. The reported incidences of the disease were standardized on the basis of the World Health Organization population and the direct method. Then the data were inserted into the GIS software, and finally, using the analysis of hot spots (Getis-Ord Gi) high-risk areas were drawn. Provinces that are higher or lower than the national average (1.9 SD) were considered hot spots or cold spots, significant at the level of 0.05. A total of 6,210 cases of colorectal cancer were registered in Iran in 2009, of which 3,727 were in men and 2,783 in women (age-standardized rates of 11.3 and 10.9 per 100,000 population, respectively). The results showed that in central and northern Iran including Isfahan, Qom, Tehran, Qazvin and Mazandaran significant hot spots in men were present (p <0.05). In women also we have high incidence in northern and central states: Mazandaran province (p<0.01) and the province of Tehran (p<0.05) had higher incidences than the national average and were apparent as significant hot spots. Analysis of the spatial distribution of colorectal cancer showed significant differences between different areas pointing to the necessity for further epidemiological studies into the etiology and early detection.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2513-2518
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• 2016

Background: In 2008, non-Hodgkin lymphoma ranked tenth among other malignancies worldwide with an incidence of around 5 cases per 100,000 in both genders. The latest available rates in Tunisia are from 2006. Materials and Methods: This study aimed to provide an update about NHL incidence for 2009 and its trend between 1998 and 2009 as well as a projection until 2024, using data from the Salah Azaiz Institute hospital registry and the Noth Tunisia cancer registry. Results: In 2009, the NHL incidence in the north of Tunisia was 4.03 cases per 100,000, 4.97 for men and 3.10 for women. Diffuse large B-cell lymphoma (DLBCL) accounted for 63.2% of all NHL subtypes. Between 1998 and 2009, the overall trend showed no significant change. When we compared the trend between two periods (1998-2005 and 2005-2009), joinpoint regression showed a significant decrease of NHL incidence in the first period with an annual percentage change (APC) of -6.7% (95% CI:[-11.2%;-2%]), then the incidence significantly increased from 2005 to 2009 with an APC of 30.5% (95% CI: [16.1%; 46.6%]. The analyses of the different subtype trends showed a significant decrease in DLBCL incidence between 1998 and 2000 (APC:-21.5; 95% CI: [-31.4%;-10.2%]) then the incidence significantly increased between 2004 and 2007 (APC: 18.5; 95% CI: [3,6%;35.5%]). Joint point analysis of the age-period-cohort model projection showed a significant increase between 2002 and 2024 with an APC of 4.5% (%95 CI: [1.5%; 7.5%]). The estimated ASR for 2024 was 4.55/100 000 (95% CI: [3.37; 6.15]). Conclusions: This study revealed an overall steady trend in the incidence of NHL in northern Tunisia between 1998 and 2009. Projection showed an increase in the incidence in NHL in both genders which draw the attention to the national and worldwide burden of this malignancy.