• 제목/요약/키워드: Reciprocal Explanation

검색결과 3건 처리시간 0.017초

음주문제와 우울 간의 인과관계와 빈곤상태 변화의 연관성 분석 (Examining the Association of Poverty Status Transition with the Causal Relationship between Drinking Problem and Depression)

  • 허만세
    • 한국사회복지학
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    • 제65권2호
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    • pp.203-230
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    • 2013
  • 본 연구는 한국복지패널의 원자료를 cross-lagged panel design에 따라 분석자료를 추출하고 인과관계 분석 모형을 이용하여 음주문제와 우울의 인과관계를 분석하였다. 나아가 빈곤이 음주문제와 우울에 영향을 미친다는 국내외 선행연구들을 바탕으로, 음주문제와 우울 간의 인과관계와 빈곤 상태의 변화가 연관성이 있는지를 살펴보았다. 연구 대상은 한국복지패널의 1차년도와 2차년도의 자료에서 반복측정된 3,976명의 성인 남녀였으며, 인과관계 분석은 McArdle and Hamagami (2001)에 의해서 정립된 Latent Difference Scores (LDS)모델을 사용하였다. 분석단계에서는 먼저 음주문제와 우울의 인과관계를 밝힌 후에, 이러한 인과관계가 빈곤의 상태변화를 나타내는 4개의 하위집단 (빈곤 지속 집단, 빈곤 탈출 집단, 비빈곤 지속 집단, 빈곤시작 집단)에서 유지되는지를 분석하였다. 분석결과 연구대상전체를 이용한 LDS모델의 결과는 우울이 음주문제의 변화를 예측할 뿐 아니라 음주 역시 우울의 변화를 예측하는 것으로 나타나 우울과 음주가 상호 인과관계를 갖는 것으로 나타났다. 전체 연구 대상자를 빈곤 상태 변화에 따른 집단으로 구분하여 분석한 결과 빈곤지속 집단에서는 우울과 음주가 상호 인과관계를 갖는 것으로 나타났고, 빈곤 시작 집단과 비빈곤 지속 집단에서는 우울의 음주 변화에 선행하는 요인으로 나타났다. 그러나 빈곤 탈출 집단에서는 음주와 우울 사이의 인과관계가 나타나지 않았다. 본 연구의 결과는 음주와 우울 사이의 인과관계가 빈곤상태변화에 따라 다르게 나타날 수 있음을 체계적으로 보여주는 새로운 결과로서 기존의 횡단연구들에서 우울과 음주의 관계에 대한 서로 상충하는 다양한 결과들에 대한 종합적 설명을 제공할 수 있다는 의미가 있다.

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한국에서 반복 자연유산을 하는 535쌍의 부부에 있어서의 세포 유전학적 연구 (Cytogenetic Study in 535 Couples with Recurrent Spontaneous Abortions in Korea)

  • 황한성;양은석;홍원기;김미순;양영호
    • Clinical and Experimental Reproductive Medicine
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    • 제32권2호
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    • pp.113-119
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    • 2005
  • Objective: The purposes of this study were to investigate the types and the incidences of chromosomal abnormalities, and to provide an explanation for the genetic causations of recurrent spontaneous abortions in Korean population. Methods: Cytogenetic studies were carried out in 535 couples with at least two spontaneous first trimester abortions from January 1981 to December 2003. For karyotype analysis, we used modified Moorhead method by Giemsa staining and Giemsa-Trypsin-Giemsa banding Results: The overall incidence of chromosome abnormality was 32 out of 535 cases (5.98%). There were 25 cases (4.67%) of translocation and 7 cases (1.31%) of inversion. In translocation, 5 cases (0.93%) of Robertsonian translocation and 20 cases (3.74%) of reciprocal translocation were observed. In inversion, 6 cases (1.12%) of inversion of chromosome 9 and one case (0.19%) of inversion of chromosome 18 were found. Conclusion: In this study, overall chromosomal abnormality rate in couples with recurrent spontaneous abortions is much higher than that in the general population. So, chromosomal analysis should be offered for the prognostic information in genetic counseling such as prenatal diagnosis in couples with repetitive reproductive failure.

Evolutionary Explanation for Beauveria bassiana Being a Potent Biological Control Agent Against Agricultural Pests

  • Han, Jae-Gu
    • 한국균학회소식:학술대회논문집
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    • 한국균학회 2014년도 춘계학술대회 및 임시총회
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    • pp.27-28
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    • 2014
  • Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.

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