• 제목/요약/키워드: Stage migration

검색결과 177건 처리시간 0.025초

Boletus rubinellus에서 감수분열 및 감수분열후 유사분열 (Meiosis and Postmeiotic Mitosis in Boletus rubinellus)

  • 윤권상
    • Journal of Plant Biology
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    • 제30권4호
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    • pp.225-247
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    • 1987
  • Meiosis and postmeiotic mitosis in Boletus rubinellus were examined ultrastructurally. Meriosis occurred at the apex of the basidium. A sausage-shaped spindle pole body(SPB) was observed along with the presence of synaptonemal complexes during pachytene and a diglobular SPB was present on late pachytene or diplotene nuclei. During metaphase I, the monoglobular SPB at the spindle pole was surrounded bya membrane and the nuclear enveloope was discontinuous. At anaphase I, the chromosomes became better defined and formed a central spindle. The nucleolus was extruded from the nucleus. During anaphase I, the SPB was excluded from the chromosomal region by a membrane and both poles were fully separated to opposite sides of the basidial wall. In meiosis II, the two nuclei divided synchronously and the spindles were parallel. The spindles were smaller than in meiosis I, while the SPB was approximately the same size as that of the similar stage in meiosis I. During anaphasetelophase II, the SPB was surrounded by a cap of endoplasmic reticulum (ER) that delimited it from the spindle. The postmeiotic interphase nuclei migrated to the mid-region of the basidium before migration to the spores. The SPB at this stage was diglobular. A postmeiotic mitosis occurred within the basidiospore, and the plane of the spindle was obique to the long axis of the spore. The spindle and SPB were smaller than at meiosis I and there were fewer nonchromosomal microtubules. At anaphase, the nucleolus was present inside the nuclear envelope but lateral to the spindle.

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전북(全北) 전주지역(全州地域) 화강암(花崗岩) 및 낭산지역(郎山地域) 화강암(花崗岩)의 풍화(風化)에 따른 화학조성(化學組成)의 변화(變化)와 주요원소(主要元素)의 상대적이동(相對的移動) (Variation of Chemical Composition and Relative migration of major Elements in the Weathering of Jeon-Ju granite and Rang-San granite)

  • 남기상
    • 자원환경지질
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    • 제8권4호
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    • pp.211-221
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    • 1975
  • Weathering of granites has a geochemical role of great significance, because of their abundance and because of chemical instability near the surface of the earth, which is more pronounced than in most other rocks. On the other hand the granites are tectonically fragile and "react" to deformation with marked facility, giving rise to a whole gamut of deformed rocks. Therefore, the writer has studied on the weathering of granitic rocks at of Iri city and Jeonju city Jeollabukdo, Korea, The fresh and weathered rocks were used as material for the investigation. The results obtained by chemical analysis and observation are as follows. 1) The order of mobility in major elements was Ca, Na and K$H_2O$ was observed clearly and late stages of weathering processes. 3) The early stage of weathering is commenced by physical weathering and followed by chemical weathering. 4) The ratio of FeO/. $Fe_2O_3$, FeO/MgO, and $SiO_2/Al_2O_3 $ decreased uniformly from early to late stage of weathering processes. 5) It was proved that weathering potential of granite was larger than that of basaltic rocks.

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백구화강암(白鷗花崗巖)의 풍화(風化)에 따른 화학조성(化學組成)의 변화(變化)와 주요원소(主要元素)의 상대적(相對的) 이동(移動) (Variation of chemical Composition and Relative migration of major Elements in the weathering of Baeg-Gu Granite)

  • 남기상
    • 자원환경지질
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    • 제7권4호
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    • pp.175-184
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    • 1974
  • Weathering of granites has a great geochemical significance, because of their chemical stability near the earth surface which is more pronounced than in most other rocks. The author intended to observe the relative mobility of major elements in weathering process of the granite, distributed on outskirts of Iri city Jeolla-bugdo, Korea. He analysed fresh granites and weathered ones from the Baeg-Gu granite mass and obtained following conclusions in the triangle-diagrams and the oxidized variation diagrams of the samples. 1) The increasing phenomena of $H_2O$ was observed clearly in early and late stages of weathering process. 2) The early stage of weathering is commenced by physical weathering and followed by chemical weathering. 3) The ratio of $FeO/Fe_2O_3$, FeO/MgO, and $SiO_2/Al_2O_3$ decreased uniformly from early to late stage of weathering processes. 4) It was proved that weathering potential of granite was larger than that of basaltic rock. 5) The order of mobility in major elements was Ca, Na and K

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겨울철 동해 북부 난바다곤쟁이류(Euphausiids)의 주야 수층별 분포 (Day-Night Vertical Distribution of Euphausiids in the Northern East Sea in Winter)

  • 이보람;이현규;지환성
    • 한국수산과학회지
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    • 제56권2호
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    • pp.259-264
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    • 2023
  • Day-night vertical euphausiid distribution was investigated at three stations in the East Sea using a Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS). Three euphausiid species were recognized. Euphausia pacifica was more dominant than Thysanoessa longipes. Euphausiids were collected at Station 1 at night, Station 2 at sunset, and Station 3 during the daytime. At Station 1, calyptopis and furcilia stages were concentrated from the surface to 30 m and 20-40 m, respectively. Juveniles and E. pacifica were distributed in strata shallower than 30 m. At Station 2, calyptopis and furcilia stages were dominant in strata from the surface to 40 m. Juveniles were not recorded in strata at 30-100 m. However, E. pacifica occurred in these strata. At Station 3, calyptopis and furcilia stages occurred in the upper 40 m of strata. E. pacifica was distributed deeper than 100 m and rarely occurred above 100 m. The furcilia stages weakly migrated, whereas the calyptopis stages did not. Juveniles and E. pacifica showed a clear migration pattern. Vertical distribution of euphausiids in the northern East Sea varied by life stage and time of day.

Adjuvant Chemotherapy with or without Concurrent Radiotherapy for Patients with Stage IB Gastric Cancer: a Subgroup Analysis of the Adjuvant Chemoradiotherapy in Stomach Tumors (ARTIST) Phase III Trial

  • Kim, Youjin;Kim, Kyoung-Mee;Choi, Min Gew;Lee, Jun Ho;Sohn, Tae Sung;Bae, Jae Moon;Kim, Sung;Lee, Su Jin;Kim, Seung Tae;Lee, Jeeyun;Park, Joon Oh;Park, Young Suk;Lim, Ho Yeong;Kang, Won Ki;Park, Se Hoon
    • Journal of Gastric Cancer
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    • 제18권4호
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    • pp.348-355
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    • 2018
  • Purpose: We aimed to discuss the roles of radiation and chemotherapy as adjuvant treatment in patients with staged IB GC who were enrolled in the adjuvant chemoradiotherapy in stomach tumors (ARTIST) trial. Materials and Methods: Among the 458 patients who were enrolled in the ARTIST trial, 99 had stage IB disease. The patients were randomly assigned to receive either adjuvant chemoradiotherapy with capecitabine plus cisplatin (XP, n=50) or chemoradiotherapy (XPRT, n=49). Survival analyses were performed in accordance with the AJCC 2010 staging system. Results: According to the AJCC 2010 system, stage migration from IB to II occurred in 71% of the patients; 98% of the T2 N0 cases were reclassified as T3 N0, and 42% of the T1 N1 cases were reclassified as T1 N2. When comparing survival outcomes between the XPRT and XP arms for stage IB cancer (AJCC 2002), no significant difference in 5-year disease-free survival (DFS) between the 2 arms was found. (median 5-year DFS, not reached, P=0.256). The patients classified as having stage IB cancer (AJCC 2002) and reclassified as having stage II cancer (AJCC 2010) exhibited worse prognoses than those who remained in stage IB, although the difference was not statistically significant (5-year DFS rate, 83% vs. 93%). When we compared 5-year DFS in 70 patients with stage II (AJCC 2010), the addition of radiotherapy to XP chemotherapy did not show better outcome than XP alone (P=0.137). Conclusions: The role of adjuvant chemoradiotherapy in the treatment of stage IB GC (AJCC 2002) warrants further investigation.

Language Anxieties Second Language Learning

  • Park, Seon-Ho
    • 한국영어학회지:영어학
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    • 제2권3호
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    • pp.373-401
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    • 2002
  • It is often observed that Korean migrant students overseas experience various kinds of anxieties learning English as a second language although they are in an English-speaking country like New Zealand. The context of learning English as a second language is explored by examining language anxieties experienced by recent Korean migrant students in New Zealand. 177 students were surveyed using questionnaires asking their anxieties over various contexts of English learning processes. The three stages of language anxiety of Input, Processing, and Output showed that there were some degrees of anxiety among the students at each stage depending on their ages, age at migration, and duration of residence, in particular. Students tended to experience more language anxiety in school than outside the school. It was also clear that students were experiencing more anxieties with English than with Korean in the four language skills of speaking, listening, reading and writing. Writing was commonly found in English and Korean to be the most frequent source of anxiety among the four language skills. Some implications from the results are suggested for parents, teachers, and students.

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Distribution of Doublecortin Immunoreactivities in Developing Chick Retina

  • Kim, Young-Hwa;Sun, Woong
    • Applied Microscopy
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    • 제42권3호
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    • pp.142-146
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    • 2012
  • Doublecortin (DCX) is a microtuble-associated protein that is required for the migration of immature neuroblasts within the chick and mammalian brain. Although it is generally thought that DCX is expressed only in the neuroblasts, some mature neurons maintain DCX expression; for example, horizontal cells in adult rat retina. In this study, we demonstrate that retinal neural progenitors in the early embryonic stage of the chick also expressed DCX, as do developing ganglion cells and horizontal cells in later stages of development. These findings raise the possibility of a role for DCX in retinal neural progenitors, before they become specialized into neuroblasts in the chick.

천이액상확산접합에 의한 합금공구강의 접합특성 (Joinability of Tool Steels by TLP Bonding)

  • 권병대;이원배;김봉수;홍태환;서창제;정승부
    • Journal of Welding and Joining
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    • 제21권4호
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    • pp.69-74
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    • 2003
  • The mechanical properties of STD11 Joints by using TLP (Transient Liquid Phase Diffusion) bonding method employing MBF-30 and MBF-80 insert metals were investigated with concerning to the microstructural change. TLP bonding of STD 11 was carried out at 1323∼1423K for 0.6ks∼3.6ks in vacuum. The microstructure and the element distribution of the interlayer between tool steels and insert metals showed specific feature with bonding conditions. It was found that the width of the interlayer increased at initial bonding stage. However, the width of interlayer showed nearly constant value during the isothermal solidification. After isothermal solidification was completed, the joint showed homogeneous element distribution and similar microstructure with base metal because of the grain boundary migration to the bonded interlayer. The bonding strength measured by a tensile test has been varied with the bonding conditions. The maximum joint strength, 760MPa, was obtained with the condition of 1423K for 1.2ks using MBF30 insert metal in this experiment.

Hepatic Toxocariasis with Atypical CT and MR Imaging Findings: a Case Report

  • Shin, Hye Soo;Shin, Kyung Sook;Lee, Jeong Eun;Min, Ji Hye;You, Sun Kyoung;Shin, Byung Seok
    • Investigative Magnetic Resonance Imaging
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    • 제22권2호
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    • pp.113-118
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    • 2018
  • Hepatic toxocariasis is a type of visceral larva migrans caused by the migration of second-stage larvae of certain nematodes such as Toxocara canis to the liver. Histologically, the condition is characterized by granulomatous lesions containing eosinophils and inflammatory cells. We report a case of hepatic toxocariasis with atypical clinical and radiologic findings presenting as distinct, solitary hepatic nodule detected in a middle-aged woman.

Monte Carlo방법을 이용한 Germanium 기판의 결공형 클러스터링 형성에 대한 연구 (A Study of Germanium Substrate Vacancy Clustering Formation using Monte Carlo Method)

  • 이준하
    • 반도체디스플레이기술학회지
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    • 제10권2호
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    • pp.45-48
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    • 2011
  • In this paper, vacancy clustering formation and diffusion of germanium substrate was studied. The analysis method was adopted Monte Carlo method. At temperatures higher than melting point, fewer clusters formed, but there was less variation in the number of clusters than at lower temperatures, as the time increased. Equilibrium diffusivities in the clustering region were $10^2$ lower than those of free vacancies in the initial stage of kinetic lattice Monte Carlo simulations. They were expressed according to three temperature regimes: at temperatures above 1,100 K, at temperatures of 1,100-900 K, and at temperatures below 900 K. The effective mean migration energy, 1.1 eV, closely coincided with that of the 1.0-1.2 eV in experiments.