• Title/Summary/Keyword: Primary productivity

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A Bibliometric Analysis of Diets and Breast Cancer Research

  • Kotepui, Manas;Wannaiampikul, Sivaporn;Chupeerach, Chaowanee;Duangmano, Suwit
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7625-7628
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    • 2014
  • Breast cancer is the most common cancer among women worldwide. The primary aim of this work was to provide an in-depth evaluation of research publications in the field of diets and breast cancer. The impact of economic outcome on national academic productivity was also investigated. Data were retrieved using Pubmed for English-language publications. The search included all research for which articles included words relating to "diets and breast cancer". Population and national income data were obtained from publicly available databases. Impact factors for journals were obtained from Journal Citation Reports$^{(R)}$ (Thomson Scientific). There were 2,396 publications from 60 countries in 384 journals with an impact factor. Among them, 1,652 (68.94%) publications were Original articles. The United States had the highest quantity (51% of total) and highest of mean impact factor (8.852) for publication. Sweden had the highest productivity of publication when adjusted for number of population (6 publications per million population). Publications from the Asian nation increased from 5.3% in 2006 to 14.6% in 2012. The Original article type was also associated with geography (p<0.001; OR=2.183; 95%CI=1.526-3.123), Asian countries produced more proportion of Original articles (82%) than those of rest of the world (67.6%). Diets and breast cancer-associated research output continues to increase annually worldwide including publications from Asian countries. Although the United States produced the most publications, European nations per capita were higher in publication output.

Development of Stress-tolerant Crop Plants

  • Choi, Hyung-In;Kang, Jung-Youn;Sohn, Hee-Kyung;Kim, Soo-Young
    • Proceedings of the Korean Society of Plant Biotechnology Conference
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    • 2002.04b
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    • pp.41-47
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    • 2002
  • Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these 'environmental or abiotic stresses', which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity. In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.

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An Assesesment of Leaf Chlorophyll Concentration of Afforestation Tree Species in South-Eastern, Nigeria

  • Udeagha, Agbaeze Umazi;Shomkegh, Simon Alyegba;Daniel, Koko Sunday
    • Journal of Forest and Environmental Science
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    • v.32 no.2
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    • pp.205-211
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    • 2016
  • Leaf chlorophyll content provides valuable information about physiological status of plants. However, fewer studies have investigated the difference in chlorophyll concentration in leaves of tropical afforestation tree species. Therefore, this study examines the difference in foliar chlorophyll contents of six tropical afforestation tree species namely: Tectona grandis, Pentaclethra macrophylla, Piptademiastrum africanum, Azadirachta indica, Brachystegia eurycoma and Gmelina arborea found in the relict forest in Umudike, South east, Nigeria. A single factor experiment in a completely randomised design in three replicates was employed to analyse the rate of leaf chlorophyll contents. Fisher's least significant different was used to test for significance in mean difference in foliar chlorophyll contents between tree species at 95% confidence interval using analysis of variance. The results of this study showed a significant difference in foliar chlorophyll concentration between the tree species with Tectona grandis having a higher chlorophyll concentration than other trees this could be as a result of its higher vegetative activity which increases its primary productivity followed by Pentaclethra macrophylla while Azadirachta indica having least the chlorophyll concentration. The study further revealed that other indigenous tree species like Piptademiastrum africanum and Brachystegia eurycoma have higher chlorophyll concentration. Further studies should be carry out to examine factors that have contributed informed the differences in the chlorophyll concentration of these trees species, thus this would broaden the understanding of their physiological status and equally encourage there conservation.

Variability of Hydrologic Partitioning revisiting Horton Index (Horton 지수의 재논의를 통한 수문분할의 변동성)

  • Choi, Dae-Gyu;Choi, Min-Ha;Ahn, Jae-Hyeon;Park, Moo-Jong;Kim, Sang-Dan
    • Journal of Wetlands Research
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    • v.13 no.1
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    • pp.35-44
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    • 2011
  • In order to explore vegetation adaptation to climate variability and the impacts on water balance dynamics, the inter-regional and the inter-annual variability of both water availability and vegetation productivity are investigated. The Horton index, which is the ratio between actual evapotranspiration and catchment wetting as a measure of vegetation water use at catchment-scale, is revisited to quantify the effects of growing-season water availability on hydrologic partitioning at catchment scale. It is shown that the estimated Horton index is relatively constant irrespective of inter-annual climate variability. In addition, the Horton index is compared with catchment-scale vegetation rain use efficiency. The results show that there is an interesting pattern in the response of vegetation water use to water availability. When water becomes the limiting factor for vegetation productivity, the catchment-scale vegetation rain use efficiency converges to a common maximum value in agreement with earlier findings at the ecosystem level.

Ecological Responses of Plants to Climate Change: Research Trends and Its Applicability in Korea (기후변화에 대한 식물의 생태적 반응: 연구동향과 한국에서의 적용가능성)

  • Kang, Hyesoon
    • Korean Journal of Ecology and Environment
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    • v.46 no.3
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    • pp.319-331
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    • 2013
  • Recent climate change, which is mostly ascribed to anthropogenic activities, is believed to be a major factor leading to biodiversity decreases and ecosystem service deteriorations. I have reviewed recent studies on climate change effects for many ecological processes involved with plants, in order to improve our understanding of the nature of ecological complexity. Plants in general have better growth and productivity under high levels of $CO_2$, although the long term effects of such $CO_2$ fertilizers are still controversial. Over the last 30 years, the Earth has been greening, particularly at higher latitudes of the Northern Hemisphere, perhaps due to a relaxation of climatic constraints. Human appropriation of net primary productivity (NPP), which corresponds up to 1/3 of global NPP, is ultimately responsible for climate change and biodiversity decreases. Climate change causes phenological variations in plants, especially in regards to spring flowering and fall leaf coloring. Many plants migrate polewards and towards higher altitudes to seek more appropriate climates. On the other hand, tree mortality and population declines have recently been reported in many continents. Landscape disturbance not only hinders the plant migration, but also makes it difficult to predict the plants' potential habitats. Plant and animal population declines, as well as local extinctions, are largely due to the disruption of species interactions through temporal mismatching. Temperature and $CO_2$ increase rates in Korea are higher than global means. The degree of landscape disturbances is also relatively high. Furthermore, long-term data on individual species responses and species interactions are lacking or quite limited in Korea. This review emphasizes the complex nature of species responses to climate change at both global and local scales. In order to keep pace with the direction and speed of climate change, it is urgently necessary to observe and analyze the patterns of phenology, migration, and trophic interactions of plants and animals in Korea's landscape.

Development of the Work Information Management System of Pavement Crack Sealing (도로면 크랙실링 작업정보 수집 관리시스템 개발)

  • Byun, Woong-Ho;Oh, Se-Wook;Lee, Hyun-Jung;Kim, Young-Suk
    • Korean Journal of Construction Engineering and Management
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    • v.8 no.5
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    • pp.80-91
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    • 2007
  • Crack in Pavements have been continually increased a by water penetration Therefore, the cracks can result in deterioration of the pavements that could be extremely dangerous fro road users. Creak sealing work performed in outdoor is very dangerous, costly and labor intensive. To slove these problems, automated crack sealing systems have been developed. it Would be needed that work information related to crack sealing must be gathered in an effort to used for existing or future crack sealing work. Furthermore, work information related to crack sealing could be utilized in analyzing work productivity and condition. The primary objective of this study is to propose a PDA and Web-based system for work information management of crack sealing which enables to effectively interchange work information between head office and fields, and to accurately collect work information. Finally, it is anticipated that the effective use of the developed PDA and web-based system would be able to effectively share work Information, measure productivity, estimate costs as well as plan future work schedule.

Growth and Yield Responses of Corn (Zea mays L.) as Affected by Growth Period and Irrigation Intensity

  • Nam, Hyo-Hoon;Seo, Myung-Chul;Cho, Hyun-Suk;Lee, Yun-Ho;Seo, Young-Jin
    • Korean Journal of Soil Science and Fertilizer
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    • v.50 no.6
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    • pp.674-683
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    • 2017
  • The frequency and intensity of soil moisture stress associated with climate change has increasing, and the stability of field crop cultivation has decreasing. This experiment was conducted to investigate the effect of soil moisture management method on growth and yield of corn. Soil moisture was managed at the grade of WSM (wet soil moisture, 34.0~42.9%), OSM (optimum soil moisture, 27.8~34.0%), DSM (dry soil moisture, 20.3~27.8%), and ESM (extreme dry moisture, 16.6~20.3%) during V8 (8th leaf stage)-VT (tasseling stage). After VT, irrigation was limited. The treated amount of irrigation was 54.1, 47.7, 44.0 and 34.5% of total water requirement, respectively. The potential evapotranspiration during the growing period was $3.29mm\;day^{-1}$, and upward movement of soil water was estimated by the AFKAE 0.5 model in the order of ESM, DSM, OSM, and WSM. We could confirm this phenomenon from actual observations. There was no significant difference in leaf characteristics, dry matter, and primary productivity depending on the level of soil moisture, but leaf development was delayed and dry weight decreased in DSM. However, dry weight and individual productivity of DSM increased after irrigation withdrawal compared to that of OSM. In DSM, ear yield and number of kernels per ear decreased, but water use efficiency and harvest index were higher than other treatments. Therefore, it is considered that the soil moisture is concentratedly managed before the V8 period, the V8-VT period is controlled within the range of 100 to 500 kPa (20.3~27.8%), and no additional irrigation is required after the VT.

Analysis of U.S. Port Efficiency Using Double-Bootstrapped DEA (이중 부트스트랩 DEA 활용한 미국항만 효율성 분석)

  • Lee, Yong Joo;Park, Hong-Gyun;Lee, Kwang-Bae
    • Journal of Korea Port Economic Association
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    • v.37 no.3
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    • pp.75-91
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    • 2021
  • Due to increased competition in supply side to reduce operational costs, port professionals have experienced extreme pressure, which demanded academicians to develop the model for efficient port operations from the industry perspective. Among many ports in the world, U.S. ports are our primary interest to analyze in our study for its high volume of cargoes transacted in the U.S. ports. We primarily employed DEA (Data Envelopment Analysis) technique to research the productivity of U.S. ports and applied the algorithm of double bootstrapped DEA proposed by Simar & Wilson (2007) to further investigate the driving forces of the performance of U.S. port operations. The external variables employed in our study comprise onDock Rail, Channel Depth, Location, Area, Acres, ForeignCargoRatio, and TEUChange, out of which onDock Rail, Acres, ForeignCargoRatio, and TEUChange were significant. In order to evaluate the effects of methodology selection, we conducted the same analysis applying the Censored model (Tobit) and contrasted the outcomes drawn from the two different techniques. Based on the findings from this work we proposed managerial implications and concluded.

Effects of different nitrogen fertilizer applications on growth of Chinese cabbage (Brassica rapa L. ssp. pekinensis)

  • Jin-Hyuk Chun;Yun-Gu Kang;Yong-Jun Yu;Jae-Han Lee;Yeo-Uk Yun;Taek-Keun Oh
    • Korean Journal of Agricultural Science
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    • v.49 no.4
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    • pp.657-666
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    • 2022
  • Nitrogen (N) is a vital element in growing crops and is essential for improving the yield and quality of crops. Thus, N fertilizer is the most widely used fertilizer and the primary N input source in soil-crop systems. Inorganic fertilizers such as urea are known to improve crop productivity and increase soil fertility. However, application with excessive amounts can interfere with crop growth and accelerate soil acidification. For these reasons, the use of organic fertilizers, which mainly contain organic nitrogen, has gradually increased worldwide. Therefore, this study evaluated the effects of N fertilizer on the growth of Chinese cabbage including its functional compounds glucosinolates (GSLs). For the cultivation of Chinse cabbage, inorganic fertilizer was used for urea, and organic fertilizers were divided into conventional and biochar-based fertilizers. The growth parameters of Chinese cabbage treated by organic fertilizers was better than those of the inorganic fertilizers. Additionally, it was found that their co-application was more efficient. However, their GSL contents were lower with the application of the organic fertilizers. The characteristics of the experimental soil also changed according to the type, amounts and co-application of fertilizers. Therefore, this study presents the basis for an eco-friendly method that can increase the functionality and productivity of Chinese cabbage compared to conventional cultivations.

Holocene Glaciomarine Sedimentation and Its Paleoclimatic Implication on the Svalbard Fjord in the Arctic Sea (북극해 스발바드 군도 피오르드에서 일어난 홀로세의 빙해양 퇴적작용과 고기후적 의미)

  • Yoon, Ho-Il;Kim, Yea-Dong;Yoo, Kyu-Cheul;Lee, Jae-Il;Nam, Seung-Il
    • Ocean and Polar Research
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    • v.28 no.1
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    • pp.1-12
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    • 2006
  • Analyses of sedimentological and geochemical parameters from two radiocarbon-dated sediment cores (JM98-845-PC and JM98-818-PC) retrieved from the central part of Isfjorden, Svalbard, in the Arctic Sea, reveal detailed paleoclimatic and paleoceanographic histories over the last 15,000 radiocarbon years. The overconsolidated diamicton at the base of core JM98-845-PC is supposed to be a basal till deposited beneath pounding glacier that had advanced during the LGM (Last Glacial Maximum). Deglaciation of the fjord commenced after the glacial maximum, marked by the deposition of interlaminated sand and mud in the ice-proximal zone by subglacial meltwater discharge, and prevailed between 13,700 and 10,800 yr B.P. with enriched-terrigenous organic materials. A return to colder conditions occurred at around 10,800 yr B.P. with a drop in TOC content, which is probably coincident with the Younger Dryas event in the North Atlantic region. At this time, an abrupt decrease of TOC content as well as an increase in C/N ratio suggests enhanced terrigenous input due to the glacial readvance. A climatic optimum is recognized between 8,395 and 2,442 yr B.P., coinciding with 'a mid-Holocene climatic optimum' in Northern Hemisphere sites (e.g., the Laurentide Ice sheet). During this time, as the sea ice receded from the fjord, enhanced primary productivity occurred in open marine conditions, resulting in the deposition of organic-enriched pebbly mud with evidence of TOC maxima and C/N ratio minima in sediments. Fast ice also disappeared from the coast, providing the maximum of IRD (ice-rafted debris) input. Around 2,442 yr B.p. (the onset of Neoglacial), pebbly mud, characterized by a decrease in TOC content, reflects the formation of more extensive sea ice and fast ice, which might cause decreased primary productivity in the surface water, as evidenced by a decrease in TOC content. Our results provide evidence of climatic change on the Svalbard fjords that helps to refine the existence and timing of late Pleistocene and Holocene millennial-scale climatic events in the Northern Hemisphere.