• Title/Summary/Keyword: chemical ecology

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Physico-chemical changes in irradiated beef and pork loins (방사선 조사가 쇠고기 및 돼지고기의 물리화학적 특성에 미치는 영향)

  • Lee, Kyong-Ae;Lee, Yoon-Jin
    • Korean Journal of Human Ecology
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    • v.13 no.6
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    • pp.1031-1036
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    • 2004
  • Effects of irradiation on physico-chemical properties of beef and pork loins were examined. Beef and pork were irradiated at dose levels of 0, 0.5, 1, 2, 3, and 5 kGy with a use of Co-60 source. The drip loss of beef increased from 0 kGy to 5 kGy, whereas that of pork remained unchanged. TBA values of beef and pork increased due to irradiation. Irradiation caused a decrease in the lightness, redness, and yellowness of beef, whereas it did an increase in the same properties of pork. Irradiation also contributed to an increase in the solubility of salt soluble protein.

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Dyeing of Cotton Knitted Fabrics using Mud (머드를 이용한 면 편성물 염색성)

  • 신인수;유복선
    • Korean Journal of Human Ecology
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    • v.5 no.2
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    • pp.93-99
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    • 2002
  • In this paper, the effect of the mud of an inorganic substance dyed on cotton knitted fabrics have been studied. The structure and chemical composition of mud was analyzed. And the far-infrared emissivity and emission power, colorfastness, anti-bacterial properties cotton knitted fabrics dyed with mud were also evaluated. The structure and chemical composition of mud was almost identical structure and to be alike main components were SiO2, A1203 and Fe203. The cotton knitted fabrics dyed with mud have good components and anti-bacterial properties. when the dyed fabrics was after-treated with diphenyl ether, the anti-bacterial property were improved. Far-infrared emissivity and emission fewer cotton knitted fabrics dyed with mud have very good.

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Change of Predator Recognition Depends on Exposure of Predation Risk Source in Captive Breed Endangered Freshwater Fish, Microphysogobio rapidus (인공증식된 멸종위기종 여울마자의 포식 위험원 노출에 따른 포식자 인지 변화)

  • Moon-Seong Heo;Min-Ho Jang;Ju-Duk Yoon
    • Korean Journal of Ecology and Environment
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    • v.56 no.4
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    • pp.406-413
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    • 2023
  • Captive breeding and reintroduction are crucial strategies for conserving endangered species populations. However, fish raised in predator-free environments, show a lack of recognition of predationrelated stimuli such as chemical and visual signals. It is critical to recognize chemical signals from injured conspecifics, also known as alarm signals, and the order or shape of predators to indicate the spread of predation risk in the habitat. We conducted a laboratory experiment to determine and adjust the optimal exposure period to induce appropriate anti-predator behavior response to different types of stimuli (Chemical, Visual and Chemical+Visual) for the endangered species Microphysogobio rapidus. Our results demonstrate that predator avoidance behavior varies depending on the types of stimuli and the duration of predation risk exposure. First, the results showed captive-breed M. rapidus show lack of response against conspecific alarm signal (Chemical cue) before the predation risk exposure period and tend to increase response over predation risk exposure time. Second, response to predator (visual cue) tend to peak at 48 hours cumulative exposure, but show dramatic decrease after 72 hours cumulative exposure. Finally, response to the mixed cue (Chemical+visual) tend to peak prior to the predation risk exposure period and show reduced response during subsequent exposure periods. This experiment confirms the lack of responsiveness to conspecific alarm signals in captive-bred M. rapidus and the need for an optimal nature behavior enhancement program prior to release of endangered species. Furthermore, responsiveness to predator visual signal peak at 48 hours cumulative exposure, suggest an optimal predation risk exposure period of up to 48 hours.

An Experimental Study of Retting Conditions of Domestic Ramie Fiber (국산 모시섬유의 침지조건에 관한 실험적 연구)

  • 이전숙;최경은
    • Korean Journal of Human Ecology
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    • v.6 no.1
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    • pp.27-34
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    • 2003
  • We investigated the bacterial and chemical retting conditions of ramie grown in Hansan. Bacterial retting was done in troughs at a temperature of 30${\pm}$2$^{\circ}C$ for 1, 2, 3, 4, 5, 6 and 10 days. Chemical retting(CR) was done at the different conditions using sodium silicate (Na$_2$SiO$_3$), sodium carbonate(Na$_2$CO$_3$) and sodium hydroxide(NaOH) as alkali solutions. The retting solution was boiled during 1. 2, 4 and 6 hours respectively at the different concentration(0.5, 2.0, 4.0, 6.0. 8.0 %) with decorticated ramie stems submerged in it. The treated ramie was then rinsing with running tap water thoroughly, which was further soaker in 0.5% acetic acid (v/v) solution for three minutes and washed thoroughly with distilled water. Finally ramie was dried for 2 hours in vacuum oven at 100 $^{\circ}C$. To know change of ramie fiber characteristics retted at the different conditions, weight loss, fiber bundle strength were tested and color, texture, luster etc. were also sensually evaluated. The results were as follows. $.$ Weight loss of ramie retted in each alkali solutions were about 10%, 20% and 30% in sodium silicate, sodium carbonate and sodium hydroxide, respectively. $.$ Chemical retting was faster than bacterial retting, but the color of chemically retted ramies were worse than that of bacterially retted ramies. $.$ The combination of bacterial and chemical processing showed some merits. A combination of either 2 or 3 days of bacterial and then chemical retting might provide the best quality ramie. $.$ Ramie fiber became cottonized ramie when retted in 8% NaOH solution for 6-8hours.

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Responses of Low-Quality Soil Microbial Community Structure and Activities to Application of a Mixed Material of Humic Acid, Biochar, and Super Absorbent Polymer

  • Li, Fangze;Men, Shuhui;Zhang, Shiwei;Huang, Juan;Puyang, Xuehua;Wu, Zhenqing;Huang, Zhanbin
    • Journal of Microbiology and Biotechnology
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    • v.30 no.9
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    • pp.1310-1320
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    • 2020
  • Low-quality soil for land reuse is a crucial problem in vegetation quality and especially to waste disposal sites in mining areas. It is necessary to find suitable materials to improve the soil quality and especially to increase soil microbial diversity and activity. In this study, pot experiments were conducted to investigate the effect of a mixed material of humic acid, super absorbent polymer and biochar on low-quality soil indexes and the microbial community response. The indexes included soil physicochemical properties and the corresponding plant growth. The results showed that the mixed material could improve chemical properties and physical structure of soil by increasing the bulk density, porosity, macro aggregate, and promote the mineralization of nutrient elements in soil. The best performance was achieved by adding 3 g·kg-1 super absorbent polymer, 3 g·kg-1 humic acid, and 10 g·kg-1 biochar to soil with plant total nitrogen, dry weight and height increased by 85.18%, 266.41% and 74.06%, respectively. Physicochemical properties caused changes in soil microbial diversity. Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Proteobacteria were significantly positively correlated with most of the physical, chemical and plant indicators. Actinobacteria and Armatimonadetes were significantly negatively correlated with most measurement factors. Therefore, this study can contribute to improving the understanding of low-quality soil and how it affects soil microbial functions and sustainability.

Comparison of Quantitative Structure-Activity Relationship and Chemical Antioxidant Activity of β-Carotene and Lycopene and Their Protective Effects on Intracellular Oxidative Stress (β-Carotene과 Lycopene의 양자역학 및 화학적 항산화능과 세포 내 산화적 스트레스 보호 효과의 비교)

  • Park, Sun Young;Jung, Hana;Jhin, Changho;Hwang, Keum Taek;Kwak, Ho-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.9
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    • pp.1143-1150
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    • 2017
  • The aim of this study was to determine the chemical and intracellular antioxidant activities of ${\beta}$-carotene and lycopene and to compare their quantitative structure-activity relationship (QSAR). In our previous study, the second ionization energy of lycopene was higher than that of ${\beta}$-carotene, as calculated by QSAR. Chemical antioxidant activities of ${\beta}$-carotene, lycopene, and Trolox were examined by measuring ferric reducing antioxidant power (FRAP) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Intracellular antioxidant activities were evaluated by intracellular reactive oxygen species (ROS) and DNA fragmentation. The FRAP of lycopene was higher than that of ${\beta}$-carotene (P<0.05), and the two carotenoids had similar antioxidant activities in DPPH radical scavenging activity assay. Trolox had the greatest chemical antioxidant activities (P<0.05). When RAW264.7 cells were treated with lipopolysaccharide (LPS) (100 ng/mL) for 20 h, intracellular ROS and DNA fragmentation significantly increased (P<0.05). RAW 264.7 cells pretreated with ${\beta}$-carotene ($4{\mu}M$) and lycopene ($0.4{\sim}2{\mu}M$) for 4 h formed significantly less intracellular ROS than LPS-treated control cells (P<0.05), whereas cells with Trolox did not reduce production of intracellular ROS. In addition, cells pretreated with $2{\mu}M$ lycopene produced less intracellular ROS than those treated with ${\beta}$-carotene (P<0.05). DNA fragmentation of cells with ${\beta}$-carotene and lycopene was similar to that of LPS-treated control cells as measured by Hoechst staining. The antioxidant ability of lycopene was greater than that of ${\beta}$-carotene in the QSAR, FRAP, and intracellular ROS assays (P<0.05). ${\beta}$-Carotene and lycopene had lower antioxidant activities as measured by FRAP (P<0.05) but higher intracellular protective effects against LPS-induced oxidative stress in comparison with Trolox.

Effect of Blending Seeds on Chemical Characteristics of Black Raspberry Wine Fermentation (씨앗의 혼입이 Black Raspberry 발효주의 화학적 특성에 미치는 영향)

  • Lee, Bo-Kyung;Shin, Hye-Hyun;Jung, Ji-Hyun;Hwang, Keum-Taek;Kim, Tae-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.5
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    • pp.580-586
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    • 2009
  • Black raspberry was fermented with or without seeds. Chemical characteristics were analyzed during wine fermentation. pH of black raspberry wine decreased in the early stage of the fermentation and thereafter increased. Total acidity increased until the 4th day of fermentation with little change afterwards. Both pH and acidity were not affected by the blending of the seeds. Sugar concentration decreased and alcohol concentration increased during the fermentation, and they were not influenced by the blending of the seeds. $L^*$, $a^*$, and $b^*$ values of black raspberry wines tended to increase until the 12th day of the fermentation and decreased or little changed thereafter. $L^*$, $a^*$, and $b^*$ values of black raspberry wines made from the fruits with seeds (BRSW) were lower than those of black raspberry wines without seeds (BRW) with no significance. Monomeric anthocyanin (MA) and polyphenol contents (PC) decreased during fermentation. MA was not significantly influenced by the blending of the seeds. PC in BRSW were higher than those in BRW with no significance. Alcohols were the major volatile components, and there were no differences between alcohol compositions in the two wines. There were also no differences in color, flavor, taste and overall acceptability in sensory characteristics. Similarity in the chemical characteristics between the BRSW and BRW suggests that development of black raspberry wine with seeds blended is possible.

Stable Carbon Isotope Signature of Dissolved Inorganic Carbon (DIC) in Two Streams with Contrasting Watershed Environments: A Potential Indicator for Assessing Stream Ecosystem Health

  • Kim, Chulgoo;Choi, Jong-Yun;Choi, Byungwoong;Lee, JunSeok;Jeon, Yonglak;Yi, Taewoo
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.2 no.4
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    • pp.259-273
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    • 2021
  • We conducted a study to investigate the characteristics of the carbon cycle of two streams (located in Shig a Prefecture, Japan), having similar size, namely, the Adokawa stream (length: 52 km, area: 305 km2, watershed population: 8,000) and the Yasukawa stream (length: 62 km, area: 380 km2, watershed population: 120,000), but with different degree of human activity. Samples were collected from these two streams at 14 (Adokawa stream) and 23 (Yasukawa stream) stations in the flowing direction. The dissolved inorganic carbon (DIC) concentration and the stable carbon isotope ratio of DIC (δ13C-DIC) were measured in addition to the watershed features and the chemical variables of the stream water. The δ13C-DIC (-9.50 ± 2.54‰), DIC concentration (249 ± 76 µM), and electric conductivity (52 ± 13 µS/cm) in Adokawa stream showed small variations from upstream to downstream. However, the δ13C-DIC (-8.68 ± 2.3‰) upstream of Yasukawa stream was similar to that of Adokawa stream and decreased downstream (-12.13 ± 0.43‰). DIC concentration (upstream: 272 ± 89 µM, downstream: 690 ± 37 µM) and electric conductivity (upstream: 69 ± 17 µS/cm, downstream: 193 ± 37 µS/cm) were higher downstream than upstream of Yasukawa stream. The DIC concentration of Yasukawa stream was significantly correlated with watershed environmental variables, such as, watershed population density (r = 0.8581, p<0.0001, n = 23), and forest area percentage of the watershed (r = -0.9188, p<0.0001, n = 23). δ13C-DIC showed significant negative correlation with the DIC concentration (r = -0.7734, p<0.0001, n = 23), electric conductivity (r = -0.5396, p = 0.0079, n = 23), and watershed population density (r = -0.6836, p = 0.0003, n = 23). Our approach using a stable carbon isotope ratio suggests that DIC concentration and δ13C-DIC could be used as indicators for monitoring the health of stream ecosystems with different watershed characteristics.