• Title/Summary/Keyword: 축적된 능력

Search Result 345, Processing Time 0.031 seconds

Research Trends of Health Recommender Systems (HRS): Applying Citation Network Analysis and GraphSAGE (건강추천시스템(HRS) 연구 동향: 인용네트워크 분석과 GraphSAGE를 활용하여)

  • Haryeom Jang;Jeesoo You;Sung-Byung Yang
    • Journal of Intelligence and Information Systems
    • /
    • v.29 no.2
    • /
    • pp.57-84
    • /
    • 2023
  • With the development of information and communications technology (ICT) and big data technology, anyone can easily obtain and utilize vast amounts of data through the Internet. Therefore, the capability of selecting high-quality data from a large amount of information is becoming more important than the capability of just collecting them. This trend continues in academia; literature reviews, such as systematic and non-systematic reviews, have been conducted in various research fields to construct a healthy knowledge structure by selecting high-quality research from accumulated research materials. Meanwhile, after the COVID-19 pandemic, remote healthcare services, which have not been agreed upon, are allowed to a limited extent, and new healthcare services such as health recommender systems (HRS) equipped with artificial intelligence (AI) and big data technologies are in the spotlight. Although, in practice, HRS are considered one of the most important technologies to lead the future healthcare industry, literature review on HRS is relatively rare compared to other fields. In addition, although HRS are fields of convergence with a strong interdisciplinary nature, prior literature review studies have mainly applied either systematic or non-systematic review methods; hence, there are limitations in analyzing interactions or dynamic relationships with other research fields. Therefore, in this study, the overall network structure of HRS and surrounding research fields were identified using citation network analysis (CNA). Additionally, in this process, in order to address the problem that the latest papers are underestimated in their citation relationships, the GraphSAGE algorithm was applied. As a result, this study identified 'recommender system', 'wireless & IoT', 'computer vision', and 'text mining' as increasingly important research fields related to HRS research, and confirmed that 'personalization' and 'privacy' are emerging issues in HRS research. The study findings would provide both academic and practical insights into identifying the structure of the HRS research community, examining related research trends, and designing future HRS research directions.

Structural Adjustment of Domestic Firms in the Era of Market Liberalization (시장개방(市場開放)과 국내기업(國內企業)의 구조조정(構造調整))

  • Seong, So-mi
    • KDI Journal of Economic Policy
    • /
    • v.13 no.4
    • /
    • pp.91-116
    • /
    • 1991
  • Market liberalization progressing simultaneously with high and rapidly rising domestic wages has created an adverse business environment for domestic firms. Korean firms are losing their international competitiveness in comparison to firms from LDC(Less Developed Countries) in low-tech industries. In high-tech industries, domestic firms without government protection (which is impossible due to the liberalization policy and the current international status of the Korean economy) are in a disadvantaged position relative to firms from advanced countries. This paper examines the division of roles between the private sector and the government in order to achieve a successful structural adjustment, which has become the impending industrial policy issue caused by high domestic wages, on the one hand, and the opening of domestic markets, on the other. The micro foundation of the economy-wide structural adjustment is actually the restructuring of business portfolios at the firm level. The firm-level business restructuring means that firms in low-value-added businesses or with declining market niches establish new major businesses in higher value-added segments or growing market niches. The adjustment of the business structure at the firm level can only be accomplished by accumulating firm-specific managerial assets necessary to establish a new business structure. This can be done through learning-by-doing in the whole system of management, including research and development, manufacturing, and marketing. Therefore, the voluntary cooperation among the people in the company is essential for making the cost of the learning process lower than that at the competing companies. Hence, firms that attempt to restructure their major businesses need to induce corporate-wide participation through innovations in organization and management, encourage innovative corporate culture, and maintain cooperative labor unions. Policy discussions on structural adjustments usually regard firms as a black box behind a few macro variables. But in reality, firm activities are not flows of materials but relationships among human resources. The growth potential of companies are embodied in the human resources of the firm; the balance of interest among stockholders, managers, and workers of the company' brings the accumulation of the company's core competencies. Therefore, policymakers and economists shoud change their old concept of the firm as a technological black box which produces a marketable commodities. Firms should be regarded as coalitions of interest groups such as stockholders, managers, and workers. Consequently the discussion on the structural adjustment both at the macroeconomic level and the firm level should be based on this new paradigm of understanding firms. The government's role in reducing the cost of structural adjustment and supporting should the creation of new industries emphasize the following: First, government must promote the competition in domestic markets by revising laws related to antitrust policy, bankruptcy, and the promotion of small and medium-sized companies. General consensus on the limitations of government intervention and the merit of deregulation should be sought among policymakers and people in the business world. In the age of internationalization, nation-specific competitive advantages cannot be exclusively in favor of domestic firms. The international competitiveness of a domestic firm derives from the firm-specific core competencies which can be accumulated by internal investment and organization of the firm. Second, government must build up a solid infrastructure of production factors including capital, technology, manpower, and information. Structural adjustment often entails bankruptcies and partial waste of resources. However, it is desirable for the government not to try to sustain marginal businesses, but to support the diversification or restructuring of businesses by assisting in factor creation. Institutional support for venture businesses needs to be improved, especially in the financing system since many investment projects in venture businesses are highly risky, even though they are very promising. The proportion of low-value added production processes and declining industries should be reduced by promoting foreign direct investment and factory automation. Moreover, one cannot over-emphasize the importance of future-oriented labor policies to be based on the new paradigm of understanding firm activities. The old laws and instititutions related to labor unions need to be reformed. Third, government must improve the regimes related to money, banking, and the tax system to change business practices dependent on government protection or undesirable in view of the evolution of the Korean economy as a whole. To prevent rational business decisions from contradicting to the interest of the economy as a whole, government should influence the business environment, not the business itself.

  • PDF

Philosophical Stances for Future Nursing Education (미래를 향한 간호교육이념)

  • Hong Yeo Shin
    • The Korean Nurse
    • /
    • v.20 no.4 s.112
    • /
    • pp.27-38
    • /
    • 1981
  • 오늘 저희에게 주어진 주제, 내일에 타당한 간호사업 및 간호교육의 향방을 어떻게 정하여야 하는가의 논의는 오늘날 간호계 주변에 일어나고 있는 변화의 실상을 이해하는 데서 비롯되어져야 한다고 생각하는 입장에서 먼저 세계적으로 건강관리사업이 당면한 딜레마가 어떠한 것이며 이러한 문제해결을 위해 어떠한 새로운 제안들이 나오고 있는가를 개관 하므로서 그 교육적 의미를 정의해 보고 장래 간호교육이 지향해야할 바를 생각해 보려 합니다. 오늘의 사회의 하나의 특징은 세계 모든 나라들이 각기 어떻게 전체 국민에게 고루 미칠 수 있는 건강관리체계를 이룩할 수 있느냐에 관심을 모으고 있는 사실이라고 봅니다. 부강한 나라에 있어서나 가장 빈궁한 나라에 있어서나 그 관심은 마찬가지로 나타나고 있읍니다. 보건진료 문제의 제기는 발달된 현대의학의 지식과 기술이 지닌 건강관리의 방대한 가능성과 건강 관리의 요구를 지닌 사람들에게 미치는 실질적인 혜택간에 점점 더 크게 벌어지는 격차에서 발생한다고 봅니다. David Rogers는 1960년대 초반까지 갖고 있던 의료지식의 축적과 민간인의 구매력 향상이 자동적으로 국민 건강의 향상을 초래할 것이라고 믿었던 순진한 꿈은 이루어지지 않았고 오히려 의료사업의 위기는 의료지식과 의료봉사간에 벌어지는 격차와 의료에 대한 막대한 투자와 그에서 얻는 건강의 혜택간의 격차에서 온다고 말하고 있읍니다. 균등 분배의 견지에서 보면 의료지식과 기술의 향상은 그 단위 투자에 대한 생산성을 낮춤으로서 오히려 장애적 요인으로 작용해온 것도 사실이고 의료의 발달에 따른 일반인의 기대 상승과 더불어 의료를 태성의 권리로 규명하는 의료보호사업의 확대로 야기되는 의료수요의 급증은 모두 기존 시설 자원에 압박을 초래하여 전래적 의료공급체제에 도전을 가해 왔으며 의료의 발달에 건 기대와는 달리 인류의 건강 문제 해결은 더욱 요원한 과제로 남게 되었읍니다. 현시점에서 세계인구의 건강문제는 기아, 영양실조, 안전한 식수 공급 및 위생적 생활환경조성의 문제에서부터 가장 정밀한 의료기술발달에 수반되는 의료사회문제에 이르는 다양한 문제를 지니고 있으며 주로 각개 국가의 경제 사회적 여건이 이 문제의 성격을 결정짓고 있다고 볼수 있읍니다. 그러나 건강 관리에 대한 요구는 영구히, 완전히 충족될 수 없는 요구에 속한다는 의미에서 경제 사회적 발달 수준에 상관없이 모든 국가가 공히 요구에 미치지 못하는 제한된 자원문제로 고심하고 있는 실정입니다. 또 하나의 공통된 관점은 각기 문제의 상황은 달라도 오늘날의 건강 문제는 주로 의료권 밖의 유전적 소인, 사회경제적, 정치문화적인 환경여건과 각기 선택하는 삶의 스타일에 깊이 관련되어 있다는 사실입니다. 따라서 오늘과 내일의 건강관리 문제는 의학적 견지에서 뿐 아니라 널리 경제, 사회, 정치, 문화적 관점에서 포괄적인 접근이 시도되어야 한다는 점과 의료의 고급화, 전문화, 일변도의 과정에서 소외되었던 기본건강관리체계 강화에 역점을 둔 다양하고 탄력성 있는 사업전개가 요구되고 있다는 점입니다. 다양한 건강관리요구에 적절히 대처할 수 있기 위한 그간 세계 각처에서 시도된 새로운 건강관리 접근과 그 제안을 살펴보면 대체로 4가지의 뚜렷한 성격들로 집약할 수 있을 것 같습니다. 그 첫째는 건강관리사업계획 및 그 수행에 있어 지역 사회의 적극적 참여를 유도하는 일, 둘째는 지역단위의 일차보건의료에서 부터 도심지 신예 종합병원, 시설 의료에 이르기까지 건강관리사업을 합리적으로 체계화하는 일. 셋째로 의료인력이용의 효율화 및 비의료인의 훈련과 협조 유발을 포함하는 효과적인 인력관리에 대한 제안과 넷째로 의료보험 및 각양 집단 의료유형을 포함하는 대체 의료재정 운영관리에 관련된 제안들을 들 수 있읍니다. 건강관리사업에 있어 지역사회 참여의 의의는 첫째로 사회 경제적인 제약이 모든 사람에게 가능한 최대한의 의료를 모두 고루 공급하기 어렵게 하고 있다는 점에서 제한된 정부재정과 지역사회가용자원을 보다 효율적으로 이용할 수 있게 하는 자조적이고 자율적인 지역사회건강관리체제의 구현에 있다고 볼 수 있으며 둘때로는 개인과 가족 및 지역민의 건강에 영향하는 많은 요인들은 실질적으로 의료권 외적 요인들로서 위생적인 생활양식, 식사습관, 의료시설이용 등 깊이 지역사회특성과 관련되어 국민보건의 실질적 향상을 위하여는 지역 주민의 자발적인 참여가 필수여건이 된다는 점 입니다. 지역 단위별 체계적인 의료사업의 전개는 제한된 의료자원의 보다 합리적이고 효율적인 이용을 가능하게 하며 요구가 있을때 언제나 가까운 거리에서 경제 사회적 제약을 받지 않고 이용할 수 있는 일차건강관리망을 통하여 건강에 관련된 정보를 얻으며 질병예방, 건강증진 및 기초적인 진료의 도움을 얻을 수 있고 의뢰에 대한 제2차, 제3차 진료에의 길은 건강관리사업의 질과 폭을 동시에 높고 넓게 해 줄 수 있는 길이 된다는 것입니다. 인력 관리에 관련된 두가지 기본 방향으로서는 첫째로 기존보건의료인력의 적정배치 유도이고 둘째는 기존인력의 역할확대, 조정 및 비의료인의 교육훈련과 부분적 업무대체를 들수 있으며 이러한 인력관리의 기본 방향은 부족되는 의료인력의 생산성을 높이고 주민들의 자조적 능력을 강화시킨다는 데에 두고 있음니다. 대체적 의료재정운영안은 대체로 의료공급과 재정관리를 이원화하여 주민의 경제능력이 의료수혜의 장애요소로 작용함을 막고 의료인의 경제적 동기에 의한 과잉치료처치에 의한 낭비를 줄임으로써 의료재정의 투자의 효과를 증대하는 데(cost-effectiveness) 그 기본방향을 두고 있다고 봅니다. 이러한 주변의료 사회적인 동향이 간호교육의 미래상에 끼치는 영향은 지대한 것이라 봅니다. 첫째로 장래 세계인구의 건강문제는 정치, 사회, 경제, 환경적인 의료권 밖의 요인들에 의해 더욱 크게 영향 받는다고 전제한다면 건강문제해결에 있어서도 전통적인 의료사업의 접근에서 더나아가 문제발생의 근원이 되는 생활개선이라는 차원에서 포괄적 접근을 생각하여야 하고 이를 위해선 정치, 경제, 사회전반에 걸친 깊이있는 이해과 주민의 생활환경에 직접 영향하는 교통수단, 통신망 mass media, 전력문제, 농업경영방법 및 조직적 사회활동 등 폭넓은 이해가 요구된다고 봅니다. 둘째로, 지역사회참여의 의의를 인정한다면 지역민의 자발적 참여를 효과적으로 유발시킬수 있고 의료집단과 각종 주민조직과 일반주민들 사이에서 협조적으로 일할수 있는 역량을 기르기위한 교육적 준비가 요구된다고 봅니다. 셋째로, 지역주민의 건강관리 자조능력 강화를 하나의 목표로 삼는다면 치료자에서 교육자로, 지도자에서 촉진자로, 제공자에서 지원자료의 역할의 변화 내지 다양화를 요구하게 될 것이므로 그에 대처할 수 있는 준비가 필요하다고 봅니다. 넷째로, 생각되어야 할 점은 지역중심건강관리사업을 지향하는 보건의료의 이념적 방향과 그에 상응하는 구체적 접근방법을 효율적으로 적용하기 위해서는 종횡으로 연결되는 의사소통체계의 정립과 민활한 정보교환이 이루어질 수 있어야 한다는 점에서 의사소통의 구심체로서 역할할 수 있는 역량을 함양해야 할 교육적 과제가 있다고 봅니다. 마지막으로 생각되어야 할 점은 지역중심으로 전개될 건강관리사업은 건강증진 및 질병예방적 측면과 질병진료 및 회복과 재활에 이르는 종합적이고 포괄적인 사업이어야 한다는 점에서 종래 공공 의료부문과 사설의료기관 사이에 나누어져 있던 예방의학과 치료의학의 통합 뿐 아니라 정부주축으로 이루어 지고 있는 지역사회개발사업 및 농촌지도사업과 종교 및 각종 민간인 집단이 벌이고있는 사업들과의 전체적인 통합적 접근이 이루어져야 한다고 생각하는 입장에서 종래 간호교육이 강조하지 않던 진료의 의무와 대외적 조직활동에 대한 보완적인 교육조치가 요구된다고 봅니다. 간호의 학문체계로서의 입장은 오랜 역사를 두고 논의의 대상이 되어왔으나 아직까지 뚜렷이 어떤 것이 간호 특유의 지식체계이며 건강문제에 관련하여 무엇이 간호특유의 결정영역이며 이 결정과 그 결과를 어떠한 방법으로 치료적 행위로 옮길 수 있는가에 대한 확실한 답을 얻지 못하고 있는 실정이라고 봅니다. 다만 근래에 제시된 여러 간호이론들 속에서 공통적으로 이야기되어지고 있는 개념들로선 우선 간호학문을 건강과 질병에 관련된 인간의 전인적이고 전체적인 상황을 다루는 학제적 과학으로서보는 입장이 있고 따라서 생물신체적인 면 외에 정신심리적, 사회경제적, 정치문화적 환경과의 상호작용 속에서 인간의 건강과 질병문제를 생각한다는 지향을 갖고 있다고 말할 수 있겠읍니다. 간호교육은 간호계 내적인 학문적, 이론적 체계화의 요구에 못지않게 대민봉사하는 전문직으로서의 사회적 책임을 감당해야하는 중요과제를 안고있어 변화하는 사회요구에 효과적으로 대처해 나가야 할 당면문제를 안고 있읍니다. 간효역할 확대, 보건진료원훈련 등 이러한 사회적 요구에 대응하려는 조치가 되겠읍니다. 이러한 시점에서 간호계가 분명히 짚고 넘어가야 할 사실은 이러한 움직임들이 종래의 의사들의 외업무공급을 연장 확대하는 입장에 서서 간호의 특수전문직 명목을 흐리게 할수있는 위험을 감수할 것인지 아니면 가능한 대체방안을 갖고 간호전문직의 독자적인 진로를 개척하면서 다각적인 도전을 받아들일 준비를 갖추든지 그 방향을 뚜렷이 해야할 일이라 생각합니다. 저로서는 이미 잘 훈련된 간호원들과 조산원들의 교육적, 경험적 배경을 기반으로 지역사회 최일선 건강관리요원으로 사회적 효능을 다 할수 있는 일차건강관리간호조직의 구현을 대체방안으로 제시하고 싶습니다. 간호원과 조산원들의 훈련된 역량과 건강관리체제의 구조적 변화를 효과적으로 조화시킨다면 대부분의 세계인구의 건강문제는 해결가능하다고 보는 입장입니다. 물론 정책과 의료와 행정적지원이 활성화되어지는 환경속에서만 그 기대하는 결과가 확대되리라는 점 부언하는 바입니다. 마지막으로 언급하고 싶은 점은 바로 오늘의 주제 ''교육의 동역자-선생과 학생''이라는 개념입니다. 특히 상회정의적 입장에서 보는 의료사업전개에 지역민 내지 의료소비자의 참여를 강조하는 현시점에 있어 교육자와 학생이 교육의 현장에서 서로 동역자로서 학습의 책임을 나누는 경험은 아주 시기적으로 적합하여 교육적으로 지대한 의미를 갖는 것이라고 생각합니다. 이에 수반되어져야 할 역할의 변화에 수용적인 자세를 갖고 적극 실제적용하려 노력하는 선생앞에서 자주적 결정을 행사해본 학생이야말로 건강관리대상자로 하여금 같은 결정권을 행사할수 있도록 촉구하여 주민의 자조적 역량을 기르고 의료사업의 민주화, 인간화를 이룩할 수 있는 길잡이가 될 수 있으리라 믿는 바입니다.

  • PDF

The responses of Growth and Physiological traits of Acer triflorum on Calcium Chloride ($CaCl_2$) Concentration (염화칼슘 농도에 따른 복자기의 생장 및 생리적 반응 특성)

  • Kwon, Min-Young;Kim, Sun-Hee;Sung, Joo-Han
    • Korean Journal of Environment and Ecology
    • /
    • v.28 no.5
    • /
    • pp.500-509
    • /
    • 2014
  • To prevent freezing of the road by fallen snow, Calcium chloride($CaCl_2$) as a deicer is used to very often and it can be harmful to roadside trees. This study was conducted to investigate the effects of Calcium chloride($CaCl_2$) as a deicer on growth and physiological traits of Acer triflorum according to different concentration of $CaCl_2$. We measured growth, chlorophyll contents, gas exchangement characteristics, chlorophyll fluorescence and mineral nutrition concentration in plant and soil. The experimental group was composed of four treatments including 0mM(control), 9mM(0.5 %), 18mM(1.0 %), 54mM(3.0 %). Before germinating new shoot, the dissolution of $CaCl_2$ was irrigated twice interval of a week. At 30 days after treatment, all treatments decreased total cholorophyll content, photosynthetic rate, transpiration rate, stomatal conductance and photochemical efficiency($F_v/F_m$) with increasing concentration of $CaCl_2$ and especially, they significantly reduced in 3.0 % treatment. In contrast, chlorophyll a/b ratio increased with an increase of $CaCl_2$ concentration and water use efficiency increased in 1.0 % and 3.0 % treatments. At 50 days after treatment, all treatments were decreased in chl a, chl b, total chlorophyll content, carotenoid content, photosynthetic capacity, photochemical efficiency($F_v/F_m$) and quantum yield of photosystem II(${\Phi}_{PSII}$) compared with control and 3.0 % treatments were withered. $Ca^{2+}$ and $Cl^-$ were accumulated in leaves and soil, which inhibited water absorption and electron transport and it caused the reduction of height growth rate more than 50 %. Although there was a little difference according to time and $CaCl_2$ concentration, all treatments decreased in growth rate and physiological activity slowed down. As time passed, these results got worse. Therefore we need to take a measure earlier in order to minimize damage of trees.

A Low Tillering Ideotype of Rice Plant for Increasing Grain Yield Potential (벼 수량성 증가를 위한 이상적인 소얼성 초형)

  • Kim, Je-kyu;Vergara, B.S.
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.36 no.2
    • /
    • pp.134-142
    • /
    • 1991
  • Since IR8, the first high-yielding rice cultivar characterised by semidwarf and high-tillering, was released in 1966, rice yields during the last two decades have apparently reached a plateau and subsequent efforts to further improve yielding ability have not resulted in visible gains. At this point of time, a new ideotype of rice plant would be necessary to increase grain yield potential. This experiment was conducted to investigate the yield contribution of different tillers within a plant in relation to an ideo type of rice plant. A low-tillering, large panicled IR25588 was compared with a high-tillering, small panicled IR58. Based on spikelet number and grain weight per panicle, the top six panicles in both low- and high-tillering cultivarswere significantly bigger than those in the other panicles. The top six panicles were M, PI, P2, P3, P4 and S1P2 in both cultivars. Their tillers had 100% probability of occurring. The top six tillers were characterised by earlier initiation and heading, longer growth duration, greater leaf area. and heavier culm and total dry weight per tiller. The top six panicles, based on grain weight was mainly due to higher spikelet number per panicle with little differences in 1,000 grain weight and percent fertility. They had also a greater number of high -density grains. The top six panicles were significantly bigger than the rest of the panicles in both low- and high-tilliering types suggesting that a new rice ideotype having six or fewer potential tillers or panicles per paint with 200 to 250 spikelets per panicle (a low-tillering, paicle weight type) may help increase grain yield potential since they have been shown to be superior physio-morphologically to the rest of the tillers.

  • PDF

Physiological Characteristics of Melon Plants Showing Leaf Yellowing Symptoms Caused by CABYV Infection (CABYV 감염 멜론의 황화증상에 따른 생리적인 특성)

  • Lee, Hee Ju;Kim, Mi-Kyeong;Lee, Sang Gyu;Choi, Chang Sun;Choi, Hong-Soo;Kwak, Hae Ryun;Choi, Gug Seoun;Chun, Changhoo
    • Horticultural Science & Technology
    • /
    • v.33 no.2
    • /
    • pp.210-218
    • /
    • 2015
  • Melon leaves showing yellowing symptoms were analyzed using electron microscopy and RT-PCR for major cucurbit-infecting-viruses (CMV, MNSV, CGMMV, SqMV, WMV, KGMMV, PRSV and ZYMV) reported in Korea, but these viruses were not detected. As the result of further analysis by next-generation sequencing (NGS), the virus was identified as Cucurbit aphid-borne yellows virus (CABYV), and then confirmed by RT-PCR using CABYV-specific primers. When photosynthetic capacity was measured based on chlorophyll fluorescence yield (ChlFY), the leaves of the diseased plants showed $4.09{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, which was one-third of the readings observed for unaffected normal plants ($12.36{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). The root functions of plants affected by leaf yellowing symptoms (LYS) was $0.28mg{\cdot}g^{-1}$, about half that measured for the normal unaffected plants ($0.48mg{\cdot}g^{-1}$). Cytological observations revealed that there were no morphological differences in the palisade parenchyma and mesophyll spongy cells of the leaves between the diseased and the normal plants. However, the same leaf cells of the affected plants contained more starch granules compared to those of the normal, unaffected plants. We conclude that the LYS of muskmelon is not merely a physiological disorder but a viral disease caused by CABYV and spread by aphids.

Study on the Biosynthetic Characteristics of Photosynthetic Pigments in Dodder(Cuscuta australis R. Br.) Plant (실새삼의 광합성색소 생합성특성에 관한 연구)

  • Kim, J.S.;Kwak, H.H.;Kim, B.C.;Cho, K.Y.
    • Korean Journal of Weed Science
    • /
    • v.17 no.3
    • /
    • pp.314-324
    • /
    • 1997
  • This study was conducted to investigate whether 1) photosynthetic pigments(chlorophylls and carotenoids) are formed in dodder plant(Cuscuta australis), 2) there are any characteristics in the pigment biosynthesis, compared to that of other normal plants, and 3) dodder responds to some herbicides having target site on chloroplast. 1. Chlorophyll content of dodder tendrill grown under a natural daylight was 9 times and 50 times lower than that of field bindweed stem and leaf, respectively. 2. The photosynthetic pigment contents varied in different tissues, being higher in a apical region than in a lower region of seedling or tendrill. Chlorophyll wasn't almost observed below the 4th internode from the upper. 3. Pigment contents were greatly dependent on light intensity so that there were 4 to 6 times difference among light conditions. When the shoot containning low pigment contents under natural light, was incubated in growth chamber with various light intensities, the pigment contents were increased by 3 times of initial contents at about 97${\mu}E$ $m^{-2}s^{-1}$PAR. While the change in pigment contents was not observed at above 450${\mu}E$ $m^{-2}s^{-1}$PAR 4. Exogenous supply of 5mM 5-aminolevulinic acid increased protochlorophyllide by 7 times and 1.4 times in the etiolated shoot from field bindweed rhizome and in dodder stem, respectively, showing that dodder relatively has a low response to 5-aminolevulinic acid. 5. Pigment loss was observed in the treatment of paraquat, norflurazon, oxyfluorfen and diuron, and protoporphyrin IX was accumulated by oxyfluorfen as in normal plants Based on above results, several chracteristics of pigment biosynthesis in dodder seem to be summerized as follows. Photosynthetic pigment biosynthesis in Cuscuta australis runs even in low level. The pigment contents is differentially distributed in different regions and their contents seem significantly to be controlled by light intensities. Especially, chloroplast rapidly tends to degenerate with the development of tissue. Some herbicides having target site on chloroplast induce damage to dodder stem but are unlikely to control it well in field, except paraquat, due to low chloroplast activity and parasitic mode of nutrition.

  • PDF

Apolipoprotein E2 & E4 Alleles Influence on the Distribution of the Human Plasma Lipid Profiles in Mormolipidemic Korean Women (아포리포 단백질 E 유전자의 E2와 E4 변이형이 정상 한국여성의 혈중 지질 수준 분포에 미치는 영향)

  • 이명숙
    • Journal of Nutrition and Health
    • /
    • v.29 no.6
    • /
    • pp.642-650
    • /
    • 1996
  • Apo E polymorphism (e2, e3, e4) was among the first reported genetic polymorphism that explained part of the normal variation in plasma cholesterol concentrations. Both alleles E2 and E4 are significantly more frequent in patients with mixed forms of hyperlipidemia and contribute on the observed differences in CHD risk among different populations. Effects of apo E polymorphism on the distribution of plasma lipid profiles were studied in 105 normolipidemic healthy women. The relative frequencies of common alleles for gene locus of apo E in this study were that E3 allele was 0.848, E4 allels was 0.087, and E2 allele was 0.067. SBP and DBP were slightly more elevated in E2 allele than those in E3 and E4. The pulsation was also significantly (p<0.016) increased by E2 allele with excess body fat % in E2 allele. There were no differences in total-, total HDL-, VLDL+LDL-, VLDL- and LDL cholesterol among the apo E alleles. However, apo E2 allele subject had lower level of total HDL and HDL2 cholesterol (P<0.047) and significantly higher lev디 of HDL3 cholesterol (P<0.05) than those in apo E3 and E4 allele subject. The conclusion is that first, it seems that apo E4-mediated alteration through LDL B/E receptors or E receptors in cholesterol metabolism results in lower plasma TG or remanate particles and in higher levels of VLDL+LDL or LDL. Second, apo E2 allele shows reciprocal effects of E4 on the plasma lipid metabolism, respecitvely. Third, apo E2 allele was more atherogenic than apo E4 because the higher levels of HDL3/HDL2 ratio and atherogenic index[(TC-HDL)/HDL]were criticized.

  • PDF

Rare Earth as a Feed Additive for Broiler Growth (육계의 성장 촉진을 위한 사료 첨가제로서의 희토(稀土))

  • Ham, S.K.;Song, T.H.;Zhang, G.Q.;Hur, S.N.;Park, H.S.
    • Korean Journal of Poultry Science
    • /
    • v.33 no.3
    • /
    • pp.233-238
    • /
    • 2006
  • In order to study the effect of feeding rare earth(RE) on growth of broiler chicks, feed conversion ratio, and probable harmfulness of feeding high levels of RE, two feeding trials with broiler chicks were conducted; one using a commercial broiler compound feed and the other using a self mixed feed excluding any growth stimulating feed additives. The the first trial used three hundred sixty of one day old Cobb broiler chicks for six levels of dietary supplementation of RE : 0, 100, 200, 400, 800 and 1,600 mg/kg. There were significant effect of RE stimulating broiler chick growth and improving feed conversion ratio, The dietary supplementation of RE at a level of 100 mg/kg was the best of all and increased body weight gain by 8.9% (p<0.05). Chicks fed RE at a level of 1,600 mg/kg grew as good as chicks fed feeds without RE and did not show my abnormalities. The second feeding trial was conducted in the same manner as the first trial using Ross broiler chicks and self-mixed experimental diets supplemented with RE at levels of 0, 50, 100 and 150 mg/kg. Differently from Results of the first trial, body weight gain and feed conversion ratio of were the best at the level of 50 mg/kg RE supplementation(p<0.05). In this trial all the birds fed RE showed significantly lower ratio of abdominal fat against live weight than those of the control group birds. Overall, it can be said that dietary supplementation of RE will improve broiler growth and feed conversion ratio and the proper dietary level would be $50\sim100mg/kg$. These results suggested that the proper level of RE for broiler chicks would be 50 to 100 mg/kg and its effectiveness is varied depending upon RE mixture. There appears abdominal fat of broiler chicks is decreased by feeding RE but further investigation is in need.

Quantitative Analysis of Magnetization Transfer by Phase Sensitive Method in Knee Disorder (무릎 이상에 대한 자화전이 위상감각에 의한 정량분석법)

  • Yoon, Moon-Hyun;Sung, Mi-Sook;Yin, Chang-Sik;Lee, Heung-Kyu;Choe, Bo-Young
    • Investigative Magnetic Resonance Imaging
    • /
    • v.10 no.2
    • /
    • pp.98-107
    • /
    • 2006
  • Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.

  • PDF