• 제목/요약/키워드: population control

검색결과 2,798건 처리시간 0.03초

도시대기오염문제와 방지대책 (Urban Air Pollution Problems and Control Strategies)

  • 동종인;조윤숭
    • 환경위생공학
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    • 제7권2호
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    • pp.69-82
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    • 1992
  • Air pollution in urban areas of Korea is considered in significantly serious level because of population exceeding the capacity and diversified facilities for the activities in socioeconomic field, education, politics and even cultural society in confined areas. Korea is one of the most populated countries and the largest five cities occupy 2.4% of total area but 45% of total population. Patterns of urban air pollution are also changing due to the change of emission sources and fuel usage. Essential recovery of urban environment in Korea has become extremely difficult and necessitates enormous investment. Accurate understanding of problems should be pursued for the efficient and effective improvement of the environment. In this article, air pollution phenomena in urban areas are analyzed mainly with respect to recent urban air pollution trend and pollution sources and possible control strategies are discussed : 1) source control-stationary and mobile, 2) air quality management strategies, 3) research and development.

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섬유질 섭취와 치질의 상관성에 관한 환자-대조군 연구 (A Case-Control Study on the Relationship of Fiber Intake and Hemorrhoids)

  • 이상선
    • Journal of Nutrition and Health
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    • 제27권1호
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    • pp.71-78
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    • 1994
  • Recently the incidence of hemorrhoids has been increased. There were various factors related to hemorrhoids, the amount of fiber intake was known as one of them. And so we performed this case-control study to investigate the association of hemorrhoids and fiber intake. The data was obtained by the combination of self-administered questionnaire and personal interview. The study population was consisted of matched 156 pairs, the cases were selected from S-hospital in Seoul, the age and sex matched control from the general population. The statistical analysis was performed by matched-analysis. The results summarized as follow : 1) As socio-economic status were low, the odds ratio of hemorrhoids were high. 2) There was significant association between hemorrhoids and regularity of eating time rather than regularity of defecation. 3) The odds ratio of hemorrhoids was 3 times higher in the presence of constipation. 4) The incidence of hemorrhoids was influenced by psychological characteristics such as somatization, obsessive-compulsive, depression, and anxiety. 5) Fiber intake was significantly lower in the cases compared to the controls. When the constipation was controlled, the fiber intake was still lower in the cases. These data provide additional evidence that the fiber intake was related to hemorrhoids.

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폴리에칠렌 차단망 설치에 의한 연초의 진딧물 전염 PVY 방제효과 (Effects of Polyethylene Net Barrier on the Control of Aphid - borne Potato Virus Y in Tobacco)

  • 채순용;김상석;박은경
    • 한국연초학회지
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    • 제16권1호
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    • pp.84-89
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    • 1994
  • Potato virus Y (PVY) is an important viral disease in burley tobacco in Korea and is mostly transmitted by green peach aphid, Myzus penicae, in nature. Effects of barrier nets on the immigration of the aphid population into tobacco fields and on the control of PVY were investigated in 3 tobacco fields with 1.8 m - height polyethylene (PE) nets on their outer - sides in Iseo - Myeon, Wanju - Kun, Cheonbuk. Immigration of aphids to the tobacco yields started at late April and reached maximum at early June. The immigrating aphid population was apparently blocked by the barrier nets to be reduced by 54-73%. PVY severity was also reduced by the barrier nets. However, the control value was variable, ranging 24-67%, which suggests that effect of the PE net barrier on the prevention of aphid-borne virus might be variable depending on the location and slope of the fields.

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STABILITY AND THE EFFECT OF HARVESTING IN A BUDWORM POPULATION MODEL

  • Zaman, Gul;Kang, Yong-Han;Jung, Il-Hyo
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제14권3호
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    • pp.163-173
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    • 2010
  • In this work, we consider a nonlinear budworm model by a system of three ordinary differential equations originally created by Ludwig et al. in 1978. The nonlinear system describes the dynamics of the interaction between a budworm and a fir forest. We introduce stability techniques to analyze the dynamical behavior of this nonlinear system. Then we use constant effort harvesting techniques to control the budworm population. We also give numerical simulations of the population model with harvest and without harvest.

Association of Hepatocyte Nuclear Factor-$4{\alpha}$ (HNF-$4{\alpha}$) Polymorphisms (rs1884614) with Type 2 Diabetes in Korean Population

  • ;유민
    • 대한의생명과학회지
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    • 제15권1호
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    • pp.101-103
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    • 2009
  • The hepatocyte nuclear factor-$4{\alpha}$ (HNF-$4{\alpha}$), transcription factor involved in the regulation of serum lipid and glucose levels, has recently been reported to be associated with type 2 diabetes. Therefore, we investigated the genotype for the rs1884614 of HNF-$4{\alpha}$ gene in Korean population and compared genotype of patients with control group. 100 patients (Male 63, Female 37), who previously underwent type 2 diabetes (T2DM) and 100 controls (Male 36, Female 64) participated in this study. According to our present study there was no association between rs1884614 polymorphism in HNF-$4{\alpha}$ gene and T2DM in Koreans although other reports showed that HNF-$4{\alpha}$ polymorphisms might be associated with the pathogenesis of T2DM in Pima Indians et al. We assume that this finding should contribute to understanding of type 2 diabetes in Korean population in detail at genetic level.

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Differentiated Thyroid Carcinoma Risk Factors in French Polynesia

  • Xhaard, Constance;Ren, Yan;Clero, Enora;Maillard, Stephane;Brindel, Pauline;Rachedi, Frederique;Boissin, Jean-Louis;Sebbag, Joseph;Shan, Larrys;Bost-Bezeaud, Frederique;Petitdidier, Patrick;Drozdovitch, Vladimir;Doyon, Francoise;Rubino, Carole;de Vathaire, Florent
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권6호
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    • pp.2675-2680
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    • 2014
  • Background: To investigate differentiated thyroid cancer risk factors in natives of French Polynesia is of interest because of the very high incidence of this cancer in the archipelago. Materials and Methods: To assess the role of various potential risk factors of thyroid cancer in the natives of French Polynesia we performed a case-control study. The study included almost all the French Polynesians diagnosed with differentiated thyroid carcinoma between 1981 and 2003 (n=229) and 373 French Polynesian control individuals from the general population without cancer. Results: Thyroid radiation dose received from nuclear fallout before the age of 15, a personal history of neck or/and head medical irradiation, obesity, tallness, large number of children, an artificial menopause, a familial history of thyroid cancer, a low dietary iodine intake, and having a spring as the main source of drinking water were found to be significant risk factors. No roles of smoking habits, alcohol consumption, iodine containing drugs, and exposure to pesticides were evidenced. Conclusions: Except for smoking, differentiated thyroid carcinoma risk factors in natives of French Polynesia are similar to those in other populations. Our finding on the role of having a spring as a drinking water origin is coherent with some other studies and could be due to geological factors.

방제방법이 땅콩뿌리혹선충 밀도와 참외 수량에 미치는 영향 (Effects of Control Methods on Yields of Oriental Melon in Fields Infested with Meloidogyne arenaria)

  • 김동근;최동로;이상범
    • 식물병연구
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    • 제7권1호
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    • pp.42-48
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    • 2001
  • 참외 연작지에서 문제가 되는 뿌리혹선충의 효율적인 방제법을 구명하기 위하여, 땅콩뿌리혹선충이 감염된 성주과채류시험장 온실에서 실험을 실시하였다. 재배적 방제로는 참깨, 파, 옥수수 및 벼를 참외 심기 전에 윤작작물로 재배하였고, 물리적 방제는 건토, 태양열처리 및 객토였으며, 화학적 방제약제로는 forthizate 입제를 사용하였다. 방제효율은 방제 방법간 큰 차이가 있었는데, 벼 윤작, 태양열처리, 객토에서 방제효과가 가장 높아 뿌리혹선충 밀도는 90% 감소하였고 참외 수량은 무처리에 비해 2배 증수되었다. 그러나 이러한 처리구에서 선충밀도가 6월 이후 다시 증가하여 처리효과는 참외 한 작기에만 유효하였다. 다음으로 효과가 높은 것은 옥수수 윤작, 건토, forthizate 처리였다. Forthizate 처리는 초기 수량에서 유의한 증수 효과가 인정되었으나(P=0.05) 후기 수량과 전체 수량에서는 증수 효과가 없었다. 윤작작물로 참깨와 파는 선충 방제 효과가 없었다.

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Relationship between Social Network and Stage of Adoption of Gastric Cancer Screening among the Korean Population

  • Lee, Myung Ha;Choi, Kui Son;Lee, Yoon Young;Suh, Mina;Jun, Jae Kwan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권10호
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    • pp.6095-6101
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    • 2013
  • Few studies have examined the relationship between social support and stages of adoption of cancer screening. Here we investigated associations between both structural and functional aspects of social support and stages of adoption of gastric cancer screening in the general population of Korea. The study population was derived from the 2011 Korean National Cancer Screening Survey (KNCSS), an annual cross-sectional survey that uses nationally representative random sampling to investigate cancer screening rates. Data were analyzed from 3,477 randomly selected respondents aged 40-74 years. Respondents were classified according to their stage of adoption of gastric cancer screening: precontemplation (13.2%), contemplation (18.0%), action/maintenance (56.1%), relapse risk (8.5%), and relapse stage (4.1%). Respondents with larger social networks were more likely to be in the contemplation/action/maintenance, or the relapse risk/relapse stages versus the precontemplation stage (OR=1.91, 95%CI: 1.52-2.91; p for tend=0.025). Emotional and instrumental supports were not associated with any stage of adoption of gastric cancer screening. However, respondents who reported receiving sufficient informational support were more likely to be in the relapse risk/relapse stages versus the precontemplation, or the contemplation/action/maintenance stage (p for trend=0.016). Interventions involving interactions between social network members could play an important role in increasing participation in gastric cancer screening.

Refining and Validating a Two-stage and Web-based Cancer Risk Assessment Tool for Village Doctors in China

  • Shen, Xing-Rong;Chai, Jing;Feng, Rui;Liu, Tong-Zhu;Tong, Gui-Xian;Cheng, Jing;Li, Kai-Chun;Xie, Shao-Yu;Shi, Yong;Wang, De-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권24호
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    • pp.10683-10690
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    • 2015
  • The big gap between efficacy of population level prevention and expectations due to heterogeneity and complexity of cancer etiologic factors calls for selective yet personalized interventions based on effective risk assessment. This paper documents our research protocol aimed at refining and validating a two-stage and web-based cancer risk assessment tool, from a tentative one in use by an ongoing project, capable of identifying individuals at elevated risk for one or more types of the 80% leading cancers in rural China with adequate sensitivity and specificity and featuring low cost, easy application and cultural and technical sensitivity for farmers and village doctors. The protocol adopted a modified population-based case control design using 72, 000 non-patients as controls, 2, 200 cancer patients as cases, and another 600 patients as cases for external validation. Factors taken into account comprised 8 domains including diet and nutrition, risk behaviors, family history, precancerous diseases, related medical procedures, exposure to environment hazards, mood and feelings, physical activities and anthropologic and biologic factors. Modeling stresses explored various methodologies like empirical analysis, logistic regression, neuro-network analysis, decision theory and both internal and external validation using concordance statistics, predictive values, etc..

선충 포식성 곰팡이를 이용한 뿌리썩이선충(Pratylenchus spp.)의 생물학적 방제 (Biological Control of Root-Lesion Nematodes(Pratylenchus spp.) by Nematode-Trapping Fungi)

  • 손흥대;김성렬;최광호;추호렬
    • 생명과학회지
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    • 제10권4호
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    • pp.403-407
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    • 2000
  • 잎들깨 재배지에서 직$\cdot$간접적으로 피해를 입히는 뿌리썩이선충(Pratylenchus spp.)의 생물학적 방제를 위해서 3종의 선충포식성 곰팡이, Arthrobotrys oligospora, A. conoides와 A. dactyloides의 선충방제 효과를 포장시험을 통하여 검정하였다. 3종의 Arthrobotrys는 1998년 잎들깨 재배지 토양에서 분리하였으며, 이들 곰팡이들은 한천배지상에서 끈끈이그물 또는 수축성 올가미와 같은 특이한 균사구조를 형성하여 뿌리썩이선층을 포획하는 것으로 관찰하였다. 야외포장 실험결과, 대조구에서는 40일 경과 후 식물기생성 선충 및 뿌리썩이선충의 밀도가 약 3.5배 증가한 반면 선충포식성 곰팡이 A. oligospora와 A. conoides 처리구에서는 단지 선충의 밀도가 큰 증감없이 접종 전의 수준을 유지하는 효과를 보였다. 그러나 A. dactyloides 처리구에서는 식물기생성 선충의 밀도를 약 65%, 뿌리썩이 선충의 밀도를 약 53% 감소시켜, 선충포식성 곰팡이의 생물학적 방제효과가 높게 나타났다.

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