• Title/Summary/Keyword: lateral dominance

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Characterization of an Arabidopsis Gene that Mediates Cytokinin Signaling in Shoot Apical Meristem Development

  • Jung, Jae-Hoon;Yun, Ju;Seo, Yeon-Hee;Park, Chung-Mo
    • Molecules and Cells
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    • v.19 no.3
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    • pp.342-349
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    • 2005
  • Cytokinins are adenine derivatives that regulate numerous plant growth and developmental processes, including apical and floral meristem development, stem growth, leaf senescence, apical dominance, and stress tolerance. However, not much is known about how cytokinin biosynthesis and metabolism is regulated. We identified a novel Arabidopsis gene, ALL, encoding an aldolase-like enzyme that regulates cytokinin signaling. An Arabidopsis mutant, all-1D, in which ALL is activated by the nearby insertion of the 35S enhancer, exhibited extreme dwarfism with rolled, dark-green leaves and reduced apical dominance, symptomatic of cytokinin-overproducing mutants. Consistent with this, ARR4 and ARR5, two representative primary cytokinin-responsive genes, were significantly induced in all-1D. Whereas SHOOT MERISTEMLESS (STM) and KNAT1, which regulate meristem development, were also greatly induced, expression of REV and PHV that regulate lateral organ polarity was inhibited. ALL encodes an aldolase-like enzyme that belongs to the HpcH/HpaI aldolase family in prokaryotes and is down-regulated by exogenous cytokinin, possibly through a negative feedback pathway. We propose that ALL is involved in cytokinin biosynthesis or metabolism and acts as a positive regulator of cytokinin signaling during shoot apical meristem development and determination of lateral organ polarity.

A Study on the Development of Laterality and Motor Abilities in Upper Extremity of Mentally Retarded Children (정신지체아 상지의 운동능력과 편측성 발달의 연구)

  • Kim, Sang-Su
    • Journal of Korean Physical Therapy Science
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    • v.3 no.1
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    • pp.835-841
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    • 1996
  • The purpose of this study is to investigate the relationship between the development of laterality and bilateral motor abilities measured with respect to various rhythm movements in upper extremity of mentally retared children. The development of laterality was measured by a survey of dominace-hand. The bilateral motor abilities were assessed by means of a tentative rhythm beat test of hands. One hundred sixty eighty subjects with special education needs shose age ranged from 7 to 18 years old were used for an experimental group. Fity nine normal children whose age ranged from 3 to 6 years old were also chosen as a control group. The major findings were a follows: 1. The development of lateral dominace-hand in mentally retared children differed from that of normal subjects with as increase in chronological age; the degree of the attainment of lateral dominance - hand was 75 percest of the mean level of the normal children. Though normal children establish a dominance - hand by ths age of years old, meatally retarded children are likely to show 57 percent of normal development at the age of 7 through 9 years old and 65 percent of normal development at the age of 16 through 18 years old. 2. A greater delay in mentally retarded was found through a rhythm test which was development to assess bilateral motor abilities in upper extremity. A closser relationship betwin chronological age and the development of bilateral motor abilities in mentally retared children was found. 3. In view of these findings, it was indicated that bilateral motor abilities of the retarded and non-retarded children were significantly correlated to the acqusition of dominance-hand.

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Crabbing Motion Testing of Waterjet-Powered Ships Using Stern Thrusters

  • Joopil Lee;Seung-Ho Ham
    • Journal of Ocean Engineering and Technology
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    • v.38 no.1
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    • pp.10-17
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    • 2024
  • This study assessed the potential for crabbing motion in waterjet ships by exclusively employing stern thrusters. The theoretical considerations were validated through practical sea trials on the naval vessel PKG (Patrol Killer Guided missile) equipped with three stern thrusters. The control forces were calculated using the force equilibrium equation. The results showed that the hull exhibited rotations and lateral movements under wind influence. The port tail exhibited a leftward turning tendency due to the wind. This phenomenon arises from the dominance of the rotational force generated by the stern thruster over the lateral force exerted by the hull, making it challenging to maintain force equilibrium. In the sea trial, the hull rotated by 10° and moved 10.8 m laterally, with a longitudinal movement of 0.26 m. Remarkably, the lateral movement surpassed the longitudinal displacement, indicating the success of the trial. The substantial lateral travel distance provided tangible evidence that the crabbing motion of the ship is achievable using only stern thrusters. This study contributes valuable insights into enhancing the maneuverability of waterjet ships, offering practical applications for naval operations and maritime activities.

Genetic Studies on Leaf Shapes in Soybeans IV. Diallel Cross Analysis on Gene Distributions Concerned with Some Characters of Soybean Leaf Parts (대두 엽형에 관한 유전연구 제4보 엽형질에 관여하는 유전자의 분포상태)

  • Chang, K.Y.;Shin, D.S.;Kim, S.H.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.26 no.4
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    • pp.332-336
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    • 1981
  • Seven soybean varieties and 21 F 2 hybrids of a diallel cross among these varieties were used as the materials, and genetic studies were conducted to evaluate the frequency and distribution of genes governing the characters of soybean leaf shapes. Partial dominance was exhibited by petiole length of trifoliates, petiole length of terminal leaflets, length of terminal leaflets, length of lateral leaflets, width of terminal leaflets Mean values of length of terminal leaflet were higher than those of lateral leaflets and length of leaflets were higher than width of leaflets, but mean values of width of terminal leaflets were shorter than those of lateral leaflets.

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Conservative neural symmetry of the caprine mandible

  • Pares-Casanova, Pere M.
    • Korean Journal of Veterinary Research
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    • v.53 no.4
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    • pp.207-210
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    • 2013
  • Fifteen dry dentate and complete mandible samples from the White Rasquera goat breed were studied for symmetry. Thirty-one landmarks were digitally located on the images of the lateral and medial aspects of each hemimandible. Distances between these landmarks allowed the evaluation of the whole hemimandible and also the neural mandible. In the studied samples, the mandible was rather symmetrical, especially in the medial neural part, and in general, there was no side dominance. Only the diastema differed significantly between the sides, and this was related to the rostral part (incisive arch). The incisive region was the least symmetrical region of the caprine mandible, indicating a modular structure more conservative for the neural part. If unsigned asymmetry is interpreted as a measure of developmental stability, then the studied breed presented a marked ability to develop in good fitness despite the harsh environment. The measurements presented here can also be used as a reference for researchers designing experimental studies, especially on mandibular catch-up growth, and as an aid for zooarchaeologists comparing results from dead animals with those from living goat populations.

Analysis of Some Korean Terminologies on the Stem Structures in Plant Morphology (식물형태학 분야에서 사용하는 줄기의 구조에 관한 한글 용어의 분석)

  • Lee, Kyu Bae
    • Journal of Integrative Natural Science
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    • v.1 no.3
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    • pp.234-246
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    • 2008
  • Korean terminologies on stem structures in plant morphology, written incorrectly in many books, were analysed to propose accurately expressed terminologies. 35 books in areas such as general biology, plant biology, plant morphology, and biological dictionaries and glossaries were selected to analyse the accuracy of the terminologies for seed structures, e.g., shoot and shoot system, rhizome, apical dominance, anticlinal and periclinal divisions, and intercalary and lateral meristems. The definition and etymology of the terminologies were traced in 4 textbooks of plant anatomy and 2 dictionaries of biology and botany written in English. On the basis of the definition, etymology, and principles for terminology formation according to the International Organization for Standardization (ISO 704:2000), reasonably expressed Korean terminologies were proposed. All of the 8 terminologies examined in this study were included in the glossary of biological terminologies, published by the Korean Association of Biological Sciences in 2005, and designated as an editorial source for science and biology textbooks for middle and high schools by Ministry of Education in 2007. However, the only 1 of the 8 terminologies described in the glossary were consistent with the proposed expression in the present study. These inconsistencies indicated the need for a reassessment of this glossary of biological terminologies. The validity of the proposed Korean terminologies was tested in a questionnaire sent to 17 professors teaching plant morphology or/and taxonomy at universities. A mean of 91.9% of the total respondents agreed with the Korean expressions proposed in this study. The new, proposed terminologies would facilitate mutual understanding between teachers and students of plant biology.

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The Effects of Instruction Using Mind Map in Middle School Science Class (중학교 과학수업에서 학생들의 뇌기능 분화에 따른 마인드 맵을 활용한 수업의 효과)

  • Chung, Young-Lan;Lee, Joo-Youn
    • Journal of The Korean Association For Science Education
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    • v.24 no.5
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    • pp.805-813
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    • 2004
  • Our educational system clearly places much greater value on left hemisphere learning. Students who process information in other ways are at a serious disadvantage and may not be learning efficiently. Since mind mapping emphasizing visual and spatial language, it helps students to use the whole brain and promotes more effective comprehension. The purpose of this research was to determine the effects of the instruction using mind map on the science achievement of students. A pretest-posttest control group design was employed. Subjects were 153 male and female, first grade students in a middle school. A control group of 83 was instructed with a traditional teaching method, and an experimental group of 70 was instructed by using a mind mapping strategy. Two groups were treated for 50 hours during 17 weeks. Tolerance's 'Style Of Learning And Thinking(SOLAT)' was used to assess students' lateralization preferences. A 30-item multiple choice posttest was used to assess students' achievement. To analyze the data, we used an analysis of covariance(ANCOVA) and i-tests. It was found that 21.6% of students was left brain dominant, 31.4%, right brain dominant and 47.1 % was integrated style. There was no gender difference in hemispheric dominance. Significant differences existed between the test scores when they were taught by using a mind map. Mind mapping turned out to be a valuable learning technique for the right brain students, helping them to achieve the same level of subject mastery as left brain students. There was a significant difference between males and females in relation to mind map application. Female scored significantly higher than males.

Effect of Dikegulac and Ancymidol on Growth and Fowering of Salvia splendens 'Bonfire' (Salvia의 생장(生長)과 개화(開花)에 미치는 Dikegulac과 Ancymidol의 효과(效果))

  • Lee, Jong Suk
    • Korean Journal of Agricultural Science
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    • v.6 no.1
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    • pp.21-26
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    • 1979
  • To compare the effect of dikegulac (sodium 2,3 : 4, 6-di-O-isopropylidene-2-keto-L-gulonate) and ancymidol (${\alpha}$-cyclopropyl-${\alpha}$-(4-methoxyphenyl)-5-pyrimidinemethanol) on the growth and flowering responses of Salvia splendens cv. Bonfire, foliar spray of dikegulac at rates of 0.06 and 0.12% and ancymidol at rates of 50 and 100 ppm, and soil drench of ancymidol at rates of 0.1 and 0.5 mg/pot were treated. Dikegulac reduced the plant height and induced the lateral shoot development by disrupting apical dominance, and thus increased the number of inflorescences and retarded flowering date. Dikegulac treatment greatly increased chlorophyll content of leaf, especially chlorophyll a. Ancymidol reduced the plant height without disrupting apical dominance and retarding flower ing date, but did not increase inflorescence number except soil drench at rate of 0.1 mg/pct. Ancymidol treatment significantly increased chlorophyll content of leaf, especially chlorophyll a. Dikegulac can be effectively used as a pinching agent and branching agent for salvia.

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Humeral, Glenoid Retroversion and Bicipital Groove Distance of the Normal Korean Adults (정상 한국 성인의 상완골과 관절와의 후경각 및 개방적 수술의 비교)

  • Kim Jin Sub;Yoo, Jung Han;Park Joo Hyuk
    • Clinics in Shoulder and Elbow
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    • v.2 no.2
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    • pp.151-156
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    • 1999
  • Purpose : Average humeral head retroversion was showed significant wide range from literatures based on variable measuring technique, We performed computed tomography(CT) study in an effort to define the specific anatomy relationships and evaluate their use. Materials and Methods : Two hundreds shoulders and distal humeri CT scan with no known pathology were examined. The study population was divided to 10 groups by gender and age (from third to seventh decade). The number of each group was twenty. Retroversion of proximal humerus and glenoid were measured using the lines that were connected the central axis of humeral head, central points of the humeral epicondyles paralleling to the trochlea, paralled to the glenoid surface, midpoint between the transverse glenoid diameter and medial edge of the scapular. We also measured the bicipital groove distance from the humeral central axis and scapulothoracic angle. Results: Retroversion of proximal humerus was highly variable, ranging in this study from 13 to 58 degrees(mean 28.73) These values correlated with sex, not age, height or hand dominance. Glenoid retroversion at the inferior sections showed average 1.3 degree, did not signigicant differences. The central axis was an average of l0mm(5-15mm) posterior to the posterior margin of the bicipital groove. Scapulothoracic angle was average 43 degrees(25-53 degrees) Conclusion: Anatomical reconstruction of retroversion angle should be individualized and bicipital groove could be useful as landmark for the lateral fin of the prosthesis to be positioned an average of 10mm posteriorly.

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Sprouting and Emergence Properties of Eleocharis kuroguwai Ohwi (올방개 괴경(塊莖)의 맹아(萌芽) 및 출현(出現) 특성(特性))

  • Lee, H.K.;Lee, I.Y.;Ryu, G.H.;Lee, J.O.;Lee, E.J.
    • Korean Journal of Weed Science
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    • v.14 no.4
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    • pp.233-238
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    • 1994
  • The experiment on sprouting and emergence properties of Eleocharis kuroguwai was conducted at laboratory and greenhouse conditions in 1993. Most of tubers had the apical dominance of buds at sprouting and had the competitive relationship for mesocotyl elongation. When pyrazosulfuron was applied on soil surface, all of apical buds were killed, but the first and second lateral buds survived to 50% and 90%, respectively, and the third lateral buds were almost at presprouted state. The tubers at 10-15cm deep soil emerged 1 week late and 35% low in emergence rate compared with the tubers at 2-5cm deep. As the plants emerged from the deep soil, the mesocotyl and the roots were distributed at deep soil more or less. Among the tubers buried at 10cm and 15cm deep soil, 25% and 30% respectively were not emergerd due to the suspension of mesocotyl elongation. Although the roots and shoots were removed from the tubers at the stage of 20cm high, all of mother tubers emerged again even 2 weeks late.

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