Follow-up Study on the Graduates of the Technical Teacher Education Program of Chungnam National university

Ru¨tters, Klaus,Ryu, Chang-Yol,Jeong, Woo-Hee 충남대학교 1992 論文集 Vol.15 No.1

한국 정부와 독일정부는 1979년 충남대학교에 공업교사 훈련 프로그램을 지원하기로 결정하였고, 1981년 이후 독일정부는 충남대학교 공업화학교육, 기계공학교육, 기술교육 분야의 교사교육 프로그램을 지원해 왔다. 본 연구의 목적은 상기 프로그램의 효과를 평가하고, 나아가 이 프로그램이 한국의 실업계 고등학교 요구에 적합한지를 파악하고자 하는 것이다. 이를 위하여 1991년 6월에 전국 53개 국공립 공업계 고등학교 교사로 재직중인 충남대학교 기계공학교육과와 공업화학교육과 출신교사 367명 전원에게 설문지를 발송하여 자료를 수집하였다. 반송된 276매의 자료를 분석하여 다음과 같은 결과를 얻을 수 있었다. 1. 국공립 공업계 고등학교교사로 재직중인 졸업생은 기계공학교육과와 공업화학교육과 전체 졸업생 수의 22%에 불과했다. 2. 교사 임용전에 1년 이상 대기한 졸업생은 15% 미만이었으며, 대부분 학교 외의 현장 경험없이 교사로 재직하기 시작하였다. 3. 대부분의 응답자는 교직 경력이 10년 정도인데, 이 중 95%가 평교사였다. 4. 응답자들은 수업, 수업준비, 학생상담, 행정업무 처리 등에 평균 주당 39시간을 쓰고 있었다. 5. 교사임용 초기에 일부 교사들은 학생상담, 수업 등에 어려움을 겪었으며, 근무환경이나 학교에서의 인간관계에 대하여 불만을 표명하였다. 6. 응답교사의 절반정도는 다른 학교로 전근하기를 원했다. 7. 교사 자격연수에 대해서는 소수의 교사만이 응답을 하였는데, 가장 관심을 나타내는 부분은 교육학과 공학 이론 및 실험 부분이었다. 8. 교사가 되고싶은 후배들에게 해주고 싶은 충고는 실습지도능력과 교사로서의 직업윤리관을 확고히 해야하며, 교양과목을 좀더 열심히 공부할 것 등이다. 9. 40% 이상의 교사들이 재학시 외국인 교수들에게 수강한 경험이 있었는데, 교수방법 및 내용이 매우 성실하고 설득력 있었으며 강의 분위기가 좋았다고 평가하였다.

SCC-DFTB Parametrizationfor Boron and Boranes

Grundkö,tter-Stock, Bernhard,Bezugly, Viktor,Kunstmann, Jens,Cuniberti, Gianaurelio,Frauenheim, Thomas,Niehaus, Thomas A. American Chemical Society 2012 Journal of chemical theory and computation Vol.8 No.3

<P>We present the results of our recent parametrization of the boron boron and boron, hydrogen interactions for the self-consistent charge density-functional-based tight-binding (SCC-DFTB) method. To evaluate the performance, we compare SCC-DFTB to full density functional theory (DFT) and wave-function-based semiempirical methods (AM1 and MNDO). Since the advantages of SCC-DFTB emerge especially for large systems, we calculated molecular systems of boranes and pure boron nanostructures. Computed bond lengths, bond angles, and vibrational frequencies are close to DFT predictions. We find that the proposed parametrization provides a transferable and balanced description of both finite and periodic systems.</P>

Highly Conductive Boron Nanotubes: Transport Properties, Work Functions, and Structural Stabilities

Bezugly, Viktor,Kunstmann, Jens,Grundkö,tter-Stock, Bernhard,Frauenheim, Thomas,Niehaus, Thomas,Cuniberti, Gianaurelio American Chemical Society 2011 ACS NANO Vol.5 No.6

<P>The transport properties, work functions, electronic structure, and structural stability of boron nanotubes with different lattice structures, radii, and chiralities are investigated theoretically. As the atomic structure of boron nanotubes and the related sheets is still under debate, three probable structural classes (nanotubes derived from the α-sheet, the buckled triangular sheet, and the distorted hexagonal sheet) are considered. For comparison with recent transport measurements [<I>J. Mater. Chem</I>. <B>2010</B>, <I>20</I>, 2197], the intrinsic conductance of ideal nanotubes with large diameters (<I>D</I> ≈ 10 nm) is determined. All considered boron nanotubes are highly conductive, irrespective of their lattice structures and chiralities, and they have higher conductivities than carbon nanotubes. Furthermore, the work functions of the three sheets and the corresponding large-diameter nanotubes are determined. It is found that the value of the nanotubes obtained from the α-sheet agrees well with the experiment. This indirectly shows that the atomic structure of boron nanotubes is related to the α-sheet. The structural stability of nanotubes with diameters > 2 nm approaches that of the corresponding boron sheets, and α-sheet nanotubes are the most stable ones. However, for smaller diameters the relative stabilities change significantly, and for diameters < 0.5 nm the most stable structures are zigzag nanotubes of the buckled triangular sheet. For structures related to the distorted hexagonal sheet the most stable nanotube is discovered to have a diameter of 0.39 nm.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2011/ancac3.2011.5.issue-6/nn201099a/production/images/medium/nn-2011-01099a_0003.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn201099a'>ACS Electronic Supporting Info</A></P>

Comparative genomics of geographically distant <i>Fusarium fujikuroi</i> isolates revealed two distinct pathotypes correlating with secondary metabolite profiles

Niehaus, Eva-Maria,Kim, Hee-Kyoung,Mü,nsterkö,tter, Martin,Janevska, Slavica,Arndt, Birgit,Kalinina, Svetlana A.,Houterman, Petra M.,Ahn, Il-Pyung,Alberti, Ilaria,Tonti, Stefano,Kim, Da-Woon,S Public Library of Science 2017 PLoS pathogens Vol.13 No.10

<▼1><P><I>Fusarium fujikuroi</I> causes <I>bakanae</I> (“foolish seedling”) disease of rice which is characterized by hyper-elongation of seedlings resulting from production of gibberellic acids (GAs) by the fungus. This plant pathogen is also known for production of harmful mycotoxins, such as fusarins, fusaric acid, apicidin F and beauvericin. Recently, we generated the first <I>de novo</I> genome sequence of <I>F</I>. <I>fujikuroi</I> strain IMI 58289 combined with extensive transcriptional, epigenetic, proteomic and chemical product analyses. GA production was shown to provide a selective advantage during infection of the preferred host plant rice. Here, we provide genome sequences of eight additional <I>F</I>. <I>fujikuroi</I> isolates from distant geographic regions. The isolates differ in the size of chromosomes, most likely due to variability of subtelomeric regions, the type of asexual spores (microconidia and/or macroconidia), and the number and expression of secondary metabolite gene clusters. Whilst most of the isolates caused the typical <I>bakanae</I> symptoms, one isolate, B14, caused stunting and early withering of infected seedlings. In contrast to the other isolates, B14 produced no GAs but high amounts of fumonisins during infection on rice. Furthermore, it differed from the other isolates by the presence of three additional polyketide synthase (PKS) genes (<I>PKS40</I>, <I>PKS43</I>, <I>PKS51</I>) and the absence of the <I>F</I>. <I>fujikuroi</I>-specific apicidin F (NRPS31) gene cluster. Analysis of additional field isolates confirmed the strong correlation between the pathotype (<I>bakanae</I> or stunting/withering), and the ability to produce either GAs or fumonisins. Deletion of the fumonisin and fusaric acid-specific PKS genes in B14 reduced the stunting/withering symptoms, whereas deletion of the <I>PKS51</I> gene resulted in elevated symptom development. Phylogenetic analyses revealed two subclades of <I>F</I>. <I>fujikuroi</I> strains according to their pathotype and secondary metabolite profiles.</P></▼1><▼2><P><B>Author summary</B></P><P><I>Fusarium fujikuroi</I> causes <I>bakanae</I> disease of rice. Infected seedlings appear to be taller and more slender when compared to healthy seedlings due to its ability to produce gibberellic acids (GAs). The disease is responsible for high yield losses, and its incidence varies with regions, rice cultivars grown and the aggressiveness of the fungal isolates. However, not all infected seedlings show <I>bakanae</I> symptoms: one of the isolates, B14, causes stunting and early withering of infected seedlings. The reason for the two pathotypes is not well understood. Researchers thought that the stunting phenotype was mostly caused by fungal-derived secondary metabolites such as fusaric acid, but there is no experimental evidence yet. B14 differs from the other strains by the presence of more PKS gene clusters, low expression of GA genes, lack of detectable levels of GAs and the production of high amounts of fumonisins in rice. Analysis of additional field isolates revealed a strong correlation between the pathotype (<I>bakanae</I> or stunting) and either GA or fumonisin production. Based on phylogenetic analyses, <I>F</I>. <I>fujikuroi</I> strains can be divided into two phylogenetically distinct subclades according to their pathotype and secondary metabolite profiles. This study provides new insights into the genomic variations and the population structure inside the species <I>F</I>. <I>fujikuroi</I> which will help to develop disease control strategies for this rice pathogen.</P></▼2>

No Concentration Decrease of House Dust Mite Allergens With Rising Altitude in Alpine Regions

Carina Grafetstätter,Johanna Prossegger,Herbert Braunschmid,Renata Sanovic,Penelope Hahne,Christina Pichler,Josef Thalhamer,Arnulf Hartl 대한천식알레르기학회 2016 Allergy, Asthma & Immunology Research Vol.8 No.4

Purpose: Several studies over the past 4 decades have indicated a significant reduction in house dust mite (HDM) and HDM allergen concentration in areas higher than 1,500 m above sea level. These have served as basis of allergen avoidance therapies for HDM allergy and asthma. However, modern construction techniques used in the insulation, heating, and glazing of buildings as well as global warming have changed the environmental parameters for HDM living conditions. The present study revisits the paradigm of decreasing HDM allergen concentrations with increasing altitude in the alpine region of Germany and Austria. Methods: A total of 122 dust samples from different abodes (hotels, privates and mountain huts) at different altitudes (400-2,600 m) were taken, and concentrations of HDM allergens were analyzed. Humidity and temperature conditions, and numerous indoor environmental parameters such as fine dust, type of flooring, age of building, and frequency of cleaning were determined. Results: HDM allergen concentrations did not significantly change with increasing altitude or relative humidity. At the level of indoor parameters, correlations could be found for different flooring types and the concentration of HDM allergens. Conclusions: In contrast to the widespread view of the relationship between altitude and HDM allergen concentrations, clinically relevant concentrations of HDM allergens could be detected in high-lying alpine regions in Austria and Germany. These results indicate that improvement in conditions of asthmatic patients sensitized against HDMs during a stay at high altitude can no longer be ascribed to decreased levels of HDM allergens, instead, other mechanisms may trigger the beneficial effect.