• 제목/요약/키워드: FOREST AGE

검색결과 743건 처리시간 0.035초

홀로세말 의림지 호소환경과 식생변천 고찰 (Late Holocene Environment and Vegetation Change of Eurimji Reservoir, Jecheon, Korea)

  • 강상준;이상헌;김주용
    • 한국제4기학회지
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    • 제23권2호
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    • pp.34-47
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    • 2009
  • 제천 의림지는 홀로세말에 형성된 호소로서 중부 내륙지역의 수문, 기후 및 식생변천 연구를 수행하기 위한 최적의 퇴적체를 포함하고 있다. 의림지 호소 퇴적체 중 ER3-1호공에서 AMS 탄소동위원소 연대측정 자료를 수반한 퇴적상과 화분군집산출상을 검토하여 고기후와 수문환경변화를 해석하였다. ER3-1호공의 고도 307.5m~309.5m 구간은 약 1,920 yrBP~1,420 yrBP 기간에 안정한 퇴적체를 보이며, 이 상부에는 과거 약 2000년 전 후에 재동된 퇴적물이 분포한다. 본 시추공의 화분군집산출을 보면 목본화분으로 소나무속, 참나무속이 우점한 것으로 보아 현존식생과 거의 유사한 식생환경으로 추론된다. 전반적으로 천변에는 오리나무속, 물푸레나무속, 버드나무속과 같은 호습윤성 교목이 생장했으며, 호안에는 부들, 수련, 고마리 등 수서식물이 생육했던 것으로 해석된다. 문화편년으로 볼 때 의림지는 청동기~철기시대 및 고대사회 초기에 축조되었던 것으로 추정된다. 의림지 입지환경과 호저 퇴적체에서 나타나는 양상은 약 3,200 yrBP~200 yrBP 기간 동안 전반적으로 서늘하고 건조한 시기(Cool and dry period)가 우세한 환경 하에서 참나무속-소나무속-전나무속을 우점으로 하는 식생군락이 형성되었던 것으로 보인다.

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Work Hours and Cognitive Function: The Multi-Ethnic Study of Atherosclerosis

  • Charles, Luenda E.;Fekedulegn, Desta;Burchfiel, Cecil M.;Fujishiro, Kaori;Hazzouri, Adina Zeki Al;Fitzpatrick, Annette L.;Rapp, Stephen R.
    • Safety and Health at Work
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    • 제11권2호
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    • pp.178-186
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    • 2020
  • Background: Cognitive impairment is a public health burden. Our objective was to investigate associations between work hours and cognitive function. Methods: Multi-Ethnic Study of Atherosclerosis (MESA) participants (n = 2,497; 50.7% men; age range 44-84 years) reported hours per week worked in all jobs in Exams 1 (2000-2002), 2 (2002-2004), 3 (2004-2005), and 5 (2010-2011). Cognitive function was assessed (Exam 5) using the Cognitive Abilities Screening Instrument (version 2), a measure of global cognitive functioning; the Digit Symbol Coding, a measure of processing speed; and the Digit Span test, a measure of attention and working memory. We used a prospective approach and linear regression to assess associations for every 10 hours of work. Results: Among all participants, associations of hours worked with cognitive function of any type were not statistically significant. In occupation-stratified analyses (interaction p = 0.051), longer work hours were associated with poorer global cognitive function among Sales/Office and blue-collar workers, after adjustment for age, sex, physical activity, body mass index, race/ethnicity, educational level, annual income, history of heart attack, diabetes, apolipoprotein E-epsilon 4 allele (ApoE4) status, birth-place, number of years in the United States, language spoken at MESA Exam 1, and work hours at Exam 5 (β = -0.55, 95% CI = -0.99, -0.09) and (β = -0.80, -1.51, -0.09), respectively. In occupation-stratified analyses (interaction p = 0.040), we also observed an inverse association with processing speed among blue-collar workers (adjusted β = -0.80, -1.52, -0.07). Sex, race/ethnicity, and ApoE4 did not significantly modify associations between work hours and cognitive function. Conclusion: Weak inverse associations were observed between work hours and cognitive function among Sales/Office and blue-collar workers.

금산지역 토양별 인삼내 비호정성 원소 특성 (Incompatible Element Characteristics of Ginsengs Growing by Different Soils of the Keumsan)

  • 송석환;민일식
    • Journal of Ginseng Research
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    • 제28권1호
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    • pp.52-59
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    • 2004
  • 충남 금산군 지역에 분포하는 세 토양인 화강암, 천매암, 셰일 지역을 선정하여 토양 시료와 함께 1년, 2년, 3년생의 인삼 시료를 채취하여 비호정 원소를 분석하였다. 토양의 경우 화강암 지역이 대부분 원소에서 높았으며 원소 쌍들과의 관계에서 셰일이 가장 높은 상관관계를 보였다. 동일 토양내 인삼 연령별 비교에서 원소 대부분이 화강암 및 천매암 지역은 2년생이,셰일 지역은 3년생이 높게 나타났다. 원소쌍에서 전 지역이 정의 상관관계가 우세하였고 2년생에 비해 3년생에서 우세하였는데 이는 지역에 관계없이 인삼의 연령이 증가함에 일정량의 원소를 흡수하기 때문으로 생각된다. 동일 연생 인삼의 지역적 비교에서 화강암 지역은 2년생의 경우 Rb, Cs, Ga가 낮았고, 3년생은 대부분 원소가 낮았으며, 셰일 지역은 대부분 원소에서 높은 함량을 보였는데 이는 토양 내의 광물 특성으로 해석된다. 인삼의 부위별 비교에서 원소 대부분이 지상부가 높은 함량을 보였고 2년생에 비해 3년생이 높은 상관관계를 보였는데 이는 연령이 증가함에 따라 이들 원소들의 상부 및 뿌리 내 흡수정도가 거의 같아지기 때문이라고 생각된다. 토양과 인삼 평균치와의 비교에서 Ba, Sr 외 원소가 토양에서 높았다.

1인가구의 품목별 소비지출 분석 (An Analysis of Single-person Households' Expenditure Pattern)

  • 박문수;정호근;김화년;고대영
    • 한국산학기술학회논문지
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    • 제16권2호
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    • pp.987-994
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    • 2015
  • 본 연구에서는 토빗모형을 이용하여 1인가구의 소비패턴이 연령별, 소득별로 얼마나 다른지 추정하였다. 분석을 위해 2006년부터 2012년까지 통계청 가계동향조사의 지출 데이터를 이용하였다. 추정결과, 음식료품, 주거 및 수도광열, 통신 지출을 제외한 모든 품목에서 1인가구의 소득탄력성은 1보다 크게 나타났으며 품목별로 다른 소비 특성을 보인다는 것을 확인했다. 또한 1인가구의 품목별 소득탄력성은 연령별, 소득별로 크게 차이를 보였다. 향후 1인가구의 관련 정책 또는 기업의 전략을 수립할 때 연령별, 소득별로 차별화된 접근이 필요할 것이다. 특히 기업은 1인가구 중 고소득 미혼자 그룹 등 구매력이 큰 소비자의 소비를 이끌어내는 전략이 필요할 것이다. 1인가구가 증가함에 따라서 음식료품이나 에너지 등과 같은 필수재구매 비중이 줄어들고 서비스에 대한 수요가 늘어날 것이다. 따라서 1인가구 증가에 따른 보건, 의료, 기사지원 등 서비스 시장 확대에 대비한 정책 대응이 필요하다.

한국 가구 하드웨어 변화 연구 - 조선시대부터 현대까지 - (A Study on Changes of Furniture Hard Ware in Korea - From the Joseon Era to Modern Times -)

  • 조숙경;문선옥
    • 한국가구학회지
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    • 제23권2호
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    • pp.122-129
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    • 2012
  • This article was intended as fundamental materials to recognize the current status of furniture hard ware in Korean market and to fix the identity of Korean furniture, by investigating and comparing the furniture hard ware used in the Joseon era and in modern times by type, function, shape and material. The analysis of furniture hard ware of the Joseon era and modern times from the view of functional aspects was oriented to the hard ware necessary to open and close the door & drawer on one side, and to that being attached to the main body of furniture not to scratch the wood by another wood on the other side, and from this the following conclusion was drawn. First of all, "Gwangdoojung" - a kind of spike- and metal decoration on the edge of the furniture disappeared, while the function-oriented hard wares have been diversified in modern times, from the perspective of the change of kinds. Second, the functional aspect of the furniture hard ware was emphasized in modern times than the Joseon era. In other words, the hard wares of the Joseon era came into view due to their strong appeal to decoration, whereas those of modern times were mostly hidden or moderated, keeping the function substantially. Third, the hard wares from the Joseon era were shown in concrete and detailed shape motivated by natural objects and furthermore even gloriously, but the modern hard wares are simple & basic geometry, from a formative point of view. Fourth, the material aspects present that the Joseon era's hard ware was mainly cast iron, whereas that of modern times shows the diversification from metal to even plastic. Finally, the recent trend in naming of the hard wares is the words of foreign origin. This resulted from that the foreign names of hard wares are valid also after import process in Korean market, so the domestic development of hard ware as the essential factor for the furniture design is urgently necessary to establish the identity of Korean modern furniture.

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Effect of Partial Replacement of Concentrates with Barhar (Artocarpus lakocha) Leaves on Growth Performance of Kids Fed a Mixed Jungle Grass-based Diet

  • Das, A.;De, D.;Katole, S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권1호
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    • pp.45-55
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    • 2011
  • A feeding trial was conducted to study the replacement value of concentrates with Barhar (Artocarpus lakocha) leaves on growth performance of kids fed a mixed jungle grass-based diet. Fifteen Sikkim local kids, about 4 months of age and body weight ranging from 5.8 to 9.2 kg, were randomly distributed into three groups of five. Kids were stall fed ad lib with mixed jungle grass collected from the nearby forest and native scrubland. The kids in group I received supplementary concentrate (Maize 35%, mustard cake 32%, rice bran 30%, mineral mixture 2% and common salt 1%) at approximately 2% of BW. For groups II and III, 25 and 50% of the concentrate was replaced with Barhar (Artocarpus lakocha) leaves, respectively. Total dry matter intake (DMI) was not significantly different among groups. Digestibility of CP decreased (p<0.05) and that of NDF increased (p<0.01) with increasing level of Barhar leaves in the diet. Digestibility of ADF (p<0.01), hemi cellulose (p<0.05) and cellulose (p<0.01) was higher in groups II and III than in group I. Ruminal pH and TVFA concentration were not significantly different among groups. Rumen ammonia-N concentration decreased (p<0.01) with increased level of Barhar leaves in the diet. Similarly, plasma urea nitrogen and blood glucose levels were reduced (p<0.05) with increasing level of Barhar leaves in the diet. Replacement of concentrate with Barhar resulted in reduced Hb and lower serum iron concentration. Levels of other serum metabolites including minerals were not altered by the replacement. Average daily gain (ADG) was 53.3, 54.4 and 41.8 g/d in groups I, II and III, respectively. ADG was not adversely affected when the level of replacement was restricted to 25%. However, at 50% of replacement ADG was significantly lower than the control (p<0.05). Thus, it was concluded that Barhar leaves might replace 25% of the supplemental concentrate for growing Sikkim local kids fed on a mixed jungle grass-based diet.

Biology of a predatory bug Eocanthecona furcellata Wolff (Hemiptera : Pentatomidae) on Vapourer tussock moth larvae: a major pest of tasar silkworm food plants

  • Siddaiah, Aruna Ambadahalli;Devi, Aribam Reema
    • International Journal of Industrial Entomology and Biomaterials
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    • 제30권1호
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    • pp.26-30
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    • 2015
  • Tropical Tasar culture is forest and agro-based activity that covers agricultural and industrial activity. Tasar silk is produced by the silkworm, Antheraea mylitta which is polyphagous in nature. A large number of pests are reported to attack both the host plant as well as silkworm. As the rearing is conducted outdoor silkworms are exposed to attack of various pests during their life cycle. Eocanthecona furcellata (Hemiptera: Pentatomidae) is the major predator of tasar silkworm during young age rearing. Both nymphs and adults of the stink bug suck the heamolymph of silkworm leading to death. The present work was undertaken to study the life cycle of E. furcellata on larvae of vapourer tussock moth which is a major pest of tasar host plants. The incubation period, nymphal duration and total developmental period from egg to adult was $8.0{\pm}0.45d$, $16.0{\pm}3.24$ and $22.0{\pm}4.20d$, respectively. Pre-oviposition, oviposition and longevity of male and female stink bug was $3.20{\pm}0.38$, $17.60{\pm}1.86$, $42.40{\pm}1.94$, $37.00{\pm}3.18d$, respectively. Analysis of the data revealed no significant difference in life cycle of the predator when provided silkworm and vapourer tussock moth larvae as hosts. Which clearly indicates that E. furcellata can multiply on vapourer tussock moth larvae during non rearing periods. Adoption of recommended pest control measures for defoliators of tasar host plants during non-rearing periods will help in reducing the incidence of host plant pests and also in reducing the incidence of stink bug during rearing season. During the study it was also observed that larvae semilooper, boll headed caterpillar and nymphs of leaf hopper serve as alternate/secondary hosts to E. furcellata during non rearing seasons.

Artificial Light at Night and Cancer: Global Study

  • Al-Naggar, Redhwan A.;Anil, Shirin
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권10호
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    • pp.4661-4664
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    • 2016
  • Background: Artificial light at night (ALAN) has been linked to increased risk of cancers in body sites like the breast and colorectum. However exposure of ALAN as an environmental risk factor and its relation to cancers in humans has never been studied in detail. Objective: To explore the association of ALAN with all forms of cancers in 158 countries. Materials and Methods: An ecological study encompassing global data was conducted from January to June 2015, with age-standardized rates (ASR) of cancers as the outcome measure. ALAN, in the protected areas, as the exposure variable, was measured with reference to the Protected Area Light Pollution Indicator (PALI) and the Protected Area Human Influence Indicator (PAHI). Pearson's correlations were calculated for PALI and PAHI with ASR of cancers for 158 countries, adjusted for country populations, electricity consumption, air pollution, and total area covered by forest. Stratified analysis was conducted according to the country income levels. Linear regression was applied to measure the variation in cancers explained by PALI and PAHI. Results: PALI and PAHI were positively associated with ASR of all forms of cancer, and also the four most common cancers (p < 0.05). These positive correlations remained statistically significant for PAHI with all forms of cancer, lung, breast, and colorectal cancer after adjusting for confounders. Positive associations of PALI and PAHI with cancers varied with income level of the individual countries. Variation in all forms of cancers, and the four most common cancers explained by PALI and PAHI, ranged from 3.3 - 35.5%. Conclusion: Artificial light at night is significantly correlated for all forms of cancer as well as lung, breast, colorectal, and prostate cancers individually. Immediate measures should be taken to limit artificial light at night in the main cities around the world and also inside houses.

오대산국립공원 소금강 계곡부 식물군집구조 (Plant Community Structure of the Soguemgang Valley in Odaesan National Park)

  • 강성칠;한봉호;박석철;최진우
    • 한국환경복원기술학회지
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    • 제19권4호
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    • pp.29-44
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    • 2016
  • This study was carried out to the structure of plant community, and ecological succession sere of forest ecosystem in Soguemgang Valley, Odaesan National Park. Fifteenth plots(size is $20m{\times}20m$) were set up and the results analyzed by DCA which is one of the ordination technique showed that the plant communities were divided into seven groups which area community I(Quercus variabilis-Pinus densiflora community), II(Pinus densiflora community), III(Pinus densiflora-Quercus variabilis community), IV(Pinus densiflora-Quercus serrata community), V(Quercus serrata community), VI(Pinus densiflora-Deciduous broad-leaved plant community), VII(Cornus controversa-Carpinus laxiflora community). Shannon diversity index per $400m^2$ was to 0.7777 to 1.1440 and the age of Pinus densiflora 86 years old, Quercus variabilis was ranged from 66 to 87 years old, Quercus serrata was ranged from 51 to 62 years old, Carpinus laxiflora was 94 years old. In 2013, the succession trend was predicted Pinus densiflora${\rightarrow}$Quercus variabilis, Quercus serrata ${\rightarrow}$Cornus controversa, Carpinus laxiflora. The ecological sucession progress has declined power of the Pinus densiflora and the increased power of the deciduous broad-leaved and Quercus spp. in Soguemgang Valley, Odaesan National Park. Quercus serrata and Quercus variabilis communities that judged Pinus densiflora were progressing by direction of landform. The southern slopes vegetation were progressing for Quercus variabilis, the northern slopes vegetation were progressing for Quercus serrata. In flat Valley, mainly native species of Cornus controversa, Carpinus laxiflora are predicted ecological succession for deciduous broad-leaved tree community.

GIS와 원격탐사를 이용한 강릉지역 산사태 연구($\textrm{I}$) -산사태 발생 위치와 영향 인자와의 상관관계 분석 (Study on Landslide using GIS and Remote Sensing at the Kangneung Area($\textrm{I}$) -Relationship Analysis between Landslide Location and Related Factors)

  • 이명진;이사로;원중선
    • 자원환경지질
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    • 제37권4호
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    • pp.425-436
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    • 2004
  • 본 연구의 목적은 2002년 태풍 루사로 인해 강릉지역에서 발생한 산사태와 관련 요인들 간의 공간적 관계를 분석하는 것이다. 산사태 위치는 위성영상 및 현지조사를 실시하여 탐지하였다. 지형도, 토양도, 임상도, 지질도, 토지피복도 등을 GIS를 이용하여 공간 데이터베이스로 구축되었고, 이러한 데이터베이스로부터, 경사, 경사방향, 곡률, 수계, 지형 종류, 토질, 토앙모재, 토앙배수, 유효토심, 임상종류, 임상경급, 임상영급, 임상밀도, 암상, 토지피복도, 선구조도 등이 산사태 발생요인으로 이용되었다. 빈도비 모델을 이용하여 산사태와 발생 요인 간의 공간적 관계를 추출하였다. 그 결과인 공간적 상관관계는 2002년 루사로 인한 산사테의 특성을 설명하고, 산사태 취약성도를 작성하는데 이용될 수 있다.