• Title/Summary/Keyword: southwestern Pacific

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Petrogenesis of Mesozoic granites at Garorim Bay, South Korea: evidence for an exotic block within the southwestern Gyeonggi massif?

  • Kim, Ji In;Choi, Sung Hi;Yi, Keewook
    • Geosciences Journal
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    • v.23 no.1
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    • pp.1-20
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    • 2019
  • We present data from the Mesozoic Keumkang, Palbong, and Baekhwa granites in Garorim Bay, in the southwestern part of the Gyeonggi massif, South Korea. Using major and trace element concentrations, Sr-Nd-Pb isotopic compositions, and sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb ages, we aim to constrain the petrogenesis of the granites and explain their origin within a broader regional geological context. SHRIMP U-Pb zircon ages of $232.8{\pm}3.2$, $175.9{\pm}1.2$, and $176.8{\pm}9.8$ Ma were obtained from the Keumkang, Palbong and Baekhwa granites, respectively. The Late Triassic Keumkang granites belong to the shoshonite series and show an overall enrichment in large ion lithophile elements (LILE), a depletion in high field strength elements (HFSE) relative to primitive mantle, compared with neighboring elements in the primitive mantle-normalized incompatible trace element diagram with notable high Ba and Sr contents, and negligible Eu anomalies. The Keumkang granites are typified by highly radiogenic Sr and unradiogenic Nd and Pb isotopic compositions: $(^{87}Sr/^{86}Sr)_i=0.70931-0.70959$, $(^{143}Nd/^{144}Nd)_i=0.511472-0.511484$ [$({\varepsilon}_{Nd})_i=-17.0$ to -16.7], and $(^{206}Pb/^{204}Pb)=17.26-17.27$. The Middle Jurassic Palbong and Baekhwa granites belong to the medium- to high-K calc-alkaline series, and show LILE enrichment and HFSE depletion similar to the Keumkang granites, but exhibit significant negative anomalies in Ba, Sr, and Eu. Furthermore, they have elevated Y and Yb contents at any given $SiO_2$ content compared with other Jurassic granitoids from the Gyeonggi massif. The Palbong and Baekhwa granites have slightly less radiogenic Sr and more radiogenic Nd and Pb isotopic compositions [$(^{87}Sr/^{86}Sr)_i=0.70396-0.70908$, $(^{143}Nd/^{144}Nd)_i=0.511622-0.511660$, $({\varepsilon}_{Nd})_i=-15.4$ to -14.7, $(^{206}Pb/^{204}Pb)=17.56-17.76$] relative to the Keumkang granites. The Keumkang granites are considered to have formed in a post-collisional environment following the Permo-Triassic Songrim orogeny that records continent-continent collision between the North and South China blocks, and may have formed by fractional crystallization of metasomatized lithospheric mantle-derived mafic melts. The Palbong and Baekhwa granites may have been produced from a gabbroic assemblage at pressures of less than ~15 kbar, associated with subduction of the paleo-Pacific (Izanagi) plate at the Eurasian continental margin. Elevated ${\varepsilon}_{Nd}(t)$ values in the granitoids from the southwestern part of the Gyeonggi massif relative to those of the central and northern parts, together with the comparatively shallow depth of origin, imply the presence of an exotic block in the Korean lithosphere.

HPV Prevalence and Cervical Intraepithelial Neoplasia among HIV-infected Women in Yunnan Province, China: A Pilot Study

  • Zhang, Hong-Yun;Tiggelaar, Sarah M.;Sahasrabuddhe, Vikrant V.;Smith, Jennifer S.;Jiang, Cheng-Qin;Mei, Run-Bo;Wang, Xian-Guo;Li, Zu-An;Qiao, You-Lin
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.1
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    • pp.91-96
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    • 2012
  • Objectives: To determine the prevalence of HPV and cervical neoplasia among HIV-infected women in southwestern China. Methods: Cervical cytology, HPV detection by Hybrid Capture-$2^{TM}$ assay, and diagnostic colposcopy were followed by cervical biopsy if indicated. Logistic regression analysis was used to analyze associations between HPV co-infection and cervical intraepithelial neoplasia (CIN), and HIV-related clinical and laboratory parameters. Results: Colposcopic-histopathologically proven CIN2+ lesions were present in 7/83 (8.4%) HIV-infected women. Nearly half (41/83, 43%) were co-infected with carcinogenic HPV genotypes. HPV co-infection was higher in women with colposcopic-histopathologically proven CIN2+ lesions than women with $cells/{\mu}L$ had higher CIN2+ prevalence after adjusting for current ART status and age (adjusted OR: 6.3, 95% CI: 1.1, 36.5). Conclusions: HIV/AIDS care and treatment programs should integrate effective cervical cancer prevention services to mitigate the risk of invasive cervical cancer among HIV-infected women in China.

Liver Cancer Mortality Characteristics and Trends in China from 1991 to 2012

  • Fang, Jia-Ying;Wu, Ku-Sheng;Zeng, Yang;Tang, Wen-Rui;Du, Pei-Ling;Xu, Zhen-Xi;Xu, Xiao-Ling;Luo, Jia-Yi;Lin, Kun
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.1959-1964
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    • 2015
  • Purpose: To investigate the distribution of liver cancer mortality as well as its developing trend from 1991 to 2012, forecast the future five-year trend, and provide a basis for the comprehensive prevention and management. Materials and Methods: Mortality data for liver cancer in China from 1991 to 2012 were used to describe characteristics and distribution of liver cancer mortality. Trend surface analysis was used to study the geographical distribution of liver cancer mortality. Curve estimation, time series modeling, gray modeling (GM) and joinpoint regression were used to predict and forecast future trends. Results: The mortality rate of liver cancer has constantly increased in China since 1991. Rates in rural areas are higher than in urban areas, and in males are higher than in females. In addition, our data predicted that the trend will continue to increase in the next 5 years. The age-specific mortality of liver cancer increases with age and peaks in the group of 80-84 years old. Geographical analysis showed the liver mortality rate was higher in the southeast provinces, such as Jiangsu, Zhejiang and Guangdong, and southwest regions like Guangxi Province. Conclusions: The standardized mortality rate of liver cancer in China has consistently increased from 1991 to 2012, and the upward trend is predicted to continue in the future. Much better prevention and management of liver cancer is needed in high mortality areas (the southwestern and southeastern parts of China) and high mortality age groups (80- to 84-year-olds), especially in rural areas.

Effects of Climatic Regime Shift on the Structure of Marine Ecosystem in the Southwestern East Sea during the 1970s (남서부 동해에서 1970년대의 기후체제전환이 생태계의 구조에 미친 영향)

  • ZHANG Chang Ik;YOON Sang Cheol
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.4
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    • pp.389-401
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    • 2003
  • The changes in structure and abundance of taxon or species groups in the East Sea ecosystem were compared between pre- and post-Climatic Regime Shift (CRS) occurred in the mid 1970s using an ECOPATH model. Although the East Sea ecosystem consisted of primary producers, primary consumers, secondary consumers and terminal consumers most species groups were classified as secondary consumers. The mean trophic level between pre- and post-CRS increased from 3.09 during the pre-CRS period to 3.28 during the post-CRS period. Total biomass of the species groups in the East Sea ecosystem increased by $9\%$ due to the CRS, and total catch increased by $48\%.$ The most significant differences between pre- and post-CRS models occurred at the mid/high trophic levels occupied by fishes and cephalopods. Relative contribution of the different species groups to the total energy flow was calculated for the trophic level III. As a result, the status by the dominant species in the East Sea ecosystem shifted from cephalopods to walleye pollock due to the CRS. Relative contribution of 5 species, which were commercially important, such as Pacific saury, Pacific sardine, filefish, walleye pollock and sandfish in trophic level III, were also changed due to the CRS. Finally, the CRS turned out to cause large variations in biomass and catch of fisheries resources as well as the status and role of the major species.

Esophageal Cancer, Gastric Cancer and the use of Pesticides in the Southwestern of Turkey

  • Yildirim, Mustafa;Kaya, Vildan;Yildiz, Mustafa;Demirpence, Ozlem;Gunduz, Seyda;Dilli, Utku Donem
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2821-2823
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    • 2014
  • Background: Esophageal and gastric cancer generally have a poor prognosis and may share common risk factors. It has been demonstrated that the pesticide usage may contribute to development of many cancer types. In this study, the relation between amount of pesticides used in agriculture and esophageal and gastric cancer incidence was researched. Materials and Methods: Findings from the data bank of the Ministry of Health Provincial Health Directorate Cancer Records Center between the years of 1998-2010 were used. All patients who were diagnosed with gastric and esophageal cancer histopathologically were included. Data for annual pesticide usage were obtained from Provincial Agriculture Directorate for the same time period. Statistical analysis was performed using the Spearman test. Results: One thousand eight hundred and ninety-six patients were involved in the study, 1,233 males (65%) and 663 females (35%), 230 with esophageal cancer (12.1%) and 1,666 with gastric cancer (87.9%). No statistically significant relation was apparent between pesticide amount used and esophageal cancer (p: 0.87). Conclusions: In our study, there was no relationship between pesticide usage and esophageal or gastric cancer. However, the time between pesticide usage and cancer development was not known, qualifying the comparison.

Colorectal Cancer Mortality in Shiraz, Iran

  • Dianatinasab, Mostafa;Ghaem, Haleh;Rezaianzadeh, Abbas;Hosseini, Seysd Vahid;Khazraei, Hajar
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.8
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    • pp.4101-4105
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    • 2016
  • Background: Mortality among Iranian patients with colorectal cancer has not been fully examined and the factors associated with their survival are still controversial. This study aimed to determine the mortality rate and its related factors among the patients with colorectal cancer in southwestern regions in Iran. Materials and Methods: This prospective cohort study was conducted on 220 patients with colorectal cancer referred to Fahighi Hospital, Shiraz, Iran from 2009 to 2014. Data were collected from the patients' medical records and were analyzed using Cox regression analysis. Results: Over a median follow-up of 29.3 months, 56 out of the 220 patients (25.5%) died, 32 (14.5%) aged below 40 years, and 45.5% were female. Based on the results of multiple Cox regression analysis, family history of gastrointestinal cancer, stage III, former smoking, type of lesion (fungative and polypoid), and opium use were associated with a greater risk of colorectal cancer mortality (all P<0.05). Conclusions: This cohort study found that the mortality rate of colorectal cancer in Iran is lower than that in European countries. In addition, behavioral and clinical factors were significantly associated with the survival rate. Addressing the related factors would help healthcare providers and physicians provide the best care and improve the survival rate.

Head and Neck Cancer in Saudi Arabia: a Systematic Review

  • Alhazzazi, Turki Y;Alghamdi, Faisal T
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.8
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    • pp.4043-4048
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    • 2016
  • Background: Head and neck cancer (HNC) is the ninth most common cancer worldwide, and has a poor 5-year survival rate averaging 50%, which has not changed for decades. A high prevalence of HNC has been reported in the southwestern region of Saudi Arabia, as compared to other areas of the country. However, data in regards to HNC are scattered and not well documented. Thus, the aim of this systematic review was to gather all available and updated important information regarding HNC in Saudi Arabia, and highlight the gaps of knowledge in our country with regard to this disease. In addition, suggestions of solutions to overcome the current status and improve our future standard of care to fight HNC are also highlighted. Materials and Methods: The electronic databases PubMed and Google Scholar using English-language literature were used for this systematic review, using specific inclusion and exclusion criteria and keywords. The search was performed in April 2016 and updated in June 2016. Results: Our search revealed twenty-one studies that fulfilled our inclusion and exclusion criteria and that were conducted in Saudi Arabia. These studies investigated different aspects of HNC, including prevalence, risk factors, biomarkers, and assessed knowledge and awareness of both public and practitioners with regard to HNC. Conclusions: This review uncovered a big gap in our epidemiological data in cancer information in general, and head and neck cancer in particular. In addition, a lack of knowledge and awareness of both the public and health care practitioners hinders the early diagnosis of disease and negatively impact the prognosis, treatment and outcome. The Ministry of Health in Saudi Arabia should develop a more systematic way and adapt policies to gather cancer information in general, and head and neck cancer in particular, from all governmental and private sectors from all over the kingdom, and develop educational programs to raise the knowledge and awareness of HNC in the country.

Influences of Climate Factors and Water Temperature in Squid Spawning Grounds on Japanese Common Squid (Todarodes pacificus) Catches in the East (Japan) Sea

  • Lee, Chung-Il
    • Fisheries and Aquatic Sciences
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    • v.10 no.3
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    • pp.150-158
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    • 2007
  • Data on squid catches, water temperature, and climatic factors collected for the Northwest and subtropical North Pacific were analyzed to examine the influence of oceanic and climatic conditions in spawning grounds on catches of Japanese common squid, Todarodes pacificus, in the East (Japan) Sea. The main spawning ground was divided into four sub-areas: the South Sea of Korea (R1), the southern waters off Jeju, Korea (R2), the southwestern part of Kyushu, Japan (R3), and the northern part of Okinawa, Japan (R4). Interannual and decadal fluctuations in water temperatures correlated well with squid catches in the East/Japan Sea. In particular, water temperatures at a depth of 50 to 100 m in sub-areas R3 and R4 showed higher correlation coefficients (0.54 to 0.59, p<0.01) in relation to squid catches in the East/Japan Sea than for R1 and R2, which had correlation coefficients of 0.40 or less (p>0.05). Air temperature and wind velocity fluctuations in each sub-area are correlated with water temperature fluctuations and were closely connected with variations in the surface mixed layers. Water, air temperatures and wind velocities at the main spawning grounds are linked to the Southern Oscillation Index (SOI) with higher signals in the ca. 2-4-year band. Strong changes in a specific band and phase occurred around 1976/77 and 1986/87, coincident with changes in squid catches.

Evolution of the eastern margin of Korea: constraints on the opening of the East Sea (Japan Sea)

  • Kim, Han-Joon;Jou, Hyeong-Tae;Suk, Bong-Chool
    • 한국지구물리탐사학회:학술대회논문집
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    • 2007.12a
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    • pp.73-83
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    • 2007
  • We interpreted marine seismic profiles in conjunction with swath bathymetric and magnetic data to investigate rifting to breakup processes at the eastern Korean margin that led to the separation of the southwestern Japan Arc. Analysis of rift fault patterns suggests that rifting at the Korean margin was primarily controlled by normal faulting resulting from extension rather than strike-slip deformation. Two extension directions of E-W and NW-SE for rifting are recognized. We interpret that the E-W direction represents initial rifting at the inner margin and the NW-SE direction probably represents the extension in response to tensional tectonics associated with the subduction of the Pacific Plate in the NW direction. No significant volcanism was involved in rifting. In contrast, the inception of sea floor spreading documents a pronounced volcanic phase which appears to reflect asthenospheric upwelling as well as rift-induced convection particularly in the narrow southern margin. We suggest that structural and igneous evolution of the Korean margin, although it is in a back-arc setting, can be explained by the processes occurring at the passive continental margin with magmatism influenced by asthenospheric upwelling.

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Geochemistry and Petrogenesis of Adakitic Granitoids from Bognae Area in the Southwestern Part of the Yeongnam Massif, Korea (영남육괴 남서부 복내지역에 분포하는 아다카이트질 화강암체의 성인 및 지화학적 특성)

  • Wee, Soo-Meen;Park, Jae-Yong
    • Journal of the Korean earth science society
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    • v.30 no.4
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    • pp.427-443
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    • 2009
  • Cretaceous intrusive and extrusive rocks in the southwestern part of the Yeongnam Massif are possibly the result of intensive magmatism which occurred in response to subduction of the Pacific plate beneath the northeast portion of the Eurasian plate. Geochemical and petrological study on the granitic rocks were carried out in order to constrain the petrogenesis of the granitic magma and to establish the paleotectonic environment of the area. Whole rock chemical data of the granitic rocks from the study area indicate that all the rocks have characteristics of calc-alkaline series in the subalkaline field. The overall geochemical features show systematic variations in each granitic body, but the source materials of each granitic body are thought to have been different in their chemical composition. The granodiorites distributed around Donggyori in the Bognae area (DGd) are different from other granitic rocks within the study area in the contents and differentiation trends of $Al_2O_3$ and MgO as well as in the contents of the trace elements such as Ba, Sr, Pb, Ni, Cr and Y DGd have geochemical features similar to slab-derived adakites such as high $Al_2O_3$, Sr contents and high Sr/Y, La/Yb ratios, but low Y and Yb contents. The major and trace element contents of the DGd fall well within the adakitic field, whereas other Cretaceous granites in the study area are plotted in the island arc ADR area in Sr/Y vs. Y diagram. On the ANK vs. A/CNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type and volcanic arc granite (VAG). Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of Pacific plate. The geochemical and tectonic features reveal that adakite-like signatures of the DGd were generated by the interaction of mantle peridotite and subducted slab-derived adakitic melts (caused by the thermal effect of ridge subduction), and which slightly modified by crustal contamination during emplacement.