• Title/Summary/Keyword: Natural Sciences

Search Result 11,641, Processing Time 0.04 seconds

Prediction of Seasonal Nitrate Concentration in Springs on the Southern Slope of Jeju Island using Multiple Linear Regression of Geographic Spatial Data (지리 공간 자료의 다중회귀분석을 이용한 제주도 남측사면 용천수의 시기별 질산성 질소 농도 예측)

  • Jung, Youn-Young;Koh, Dong-Chan;Kang, Bong-Rae;Ko, Kyung-Suk;Yu, Yong-Jae
    • Economic and Environmental Geology
    • /
    • v.44 no.2
    • /
    • pp.135-152
    • /
    • 2011
  • Nitrate concentrations in springs at the southern slope of Jeju Island were predicted using multiple linear regression (MLR) of spatial variables including hydrogeological parameters and land use characteristics. Springs showed wide range of nitrate concentrations from <0.02 to 86 mg/L with a mean of 20 mg/L. Spatial variables were generated for the circular buffer when the optimal buffer radius was assigned as 400 m. Selected regression models were tested using the p values and Durbin-Watson statistics. Explanatory variables were selected using the adjusted $R^2$, Cp (total squared error) and AIC (Akaike's Information Criterion), and significance. In addition, mutual linear relations between variables were also considered. Small portion of springs, usually <10% of total samples, were identified as outliers indicating limitations of MLR using circular buffers. Adjusted $R^2$ of the proposed models was improved from 0.75 to 0.87 when outliers were eliminated. In particular, the areal proportion of natural area had the greatest influence on the nitrate concentrations in springs. Among anthropogenic land uses, the influence of nitrate contamination is diminishing in the following order of orchard, residential area, and dry farmland. It is apparent quality of springs in the study area is likely to be controlled by land uses instead of hydrogeological parameters. Most of all, it is worth highlighting that the contamination susceptibility of springs is highly sensitive to nearby land uses, in particular, orchard.

Nitrate and Nitrite Content of Some Fermented Sea Foods and Vegetables (시판젓갈류와 채소류중의 질산염 및 아질산염함량)

  • LEE Eung-Ho;KIM Se-Kwon;JEON Joong-Kyun;CHUNG Sook-Hyun;CHA Yong-Jun;KIM Soo-Hyun;KIM Kyung-Sam
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.15 no.2
    • /
    • pp.147-153
    • /
    • 1982
  • Nitrate and nitrite, which readily produce N-nitrosamines by reaction with secondary amines, are widely distributed in natural products such as vegetables and cereals, and are also used as a color fixation in meat products or fish roes. This experiment was carried out to determine the contents of nitrate and nitrite in foods such as fermented sea foods and fresh vegetables purchased at markets in Korea. The contents of nitrate were $0.74\sim13.81\;ppm$ for fermented sea foods and $4.0\sim1,572.5\;ppm$for fresh vegetables. As for vegetables, the nitrate levels of edible herbs were relatively higher than those of greens, fruits and rootcrops. The nitrite contents in fermented demoisells(Chromis notatus), fermented shrimp, fermented small squid, fermented anchovy and salted Alaska pollack roe were very little, while those in fermented hairtail and fermented entrails were not detected. As for vegetables, nitrite levels found for cabbage and lettuce were relatively as high as 3.8 ppm and $2.5\sim2.9\;ppm$, respectively, but were not detected in Korean cabbage, green perilla leaf, pepper, garlic and burdock. Of vegetables, the nitrate values in the outer part of Korean cabbage, stems of water cress and leaves of green onion were higher than in the other parts. Little variety of the nitrate levels were found during 4 days storage. In the comparison of low temperature storage and room temperature storage, lettuce, pumpkin and spinach contained higher levels of nitrate at low temperature storage, while eggplant and green onion, at room temperature storage.

  • PDF

Antibacterial Effect of Cinnamon (Cinnamomum cassia) Bark Extract against Fish Pathogenic Bacteria (계피 추출물의 어류 질병 세균에 대한 항균 효과)

  • MOK Jong-Soo;SONG Ki-Cheol;CHOI Nack-Joong;YANG Ho-Shik
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.34 no.5
    • /
    • pp.545-549
    • /
    • 2001
  • To develop a natural antibacterial agent for fish bacterial diseases, antibacterial activity, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and bactericidal effect of cinnamon bark extract were examined against fish pathogenic bacteria. The antimicrobial effect of the extract to the fish diet was also estimated, Cinnamon bark extract showed the broad spectrum of antibacterial activity against fish pathogenic bacteria, especially, it had strong activity against Streptococcus iniae, Edwardsiella tarda and Listonella anguillarum. Its MIC was $75.8\sim189.6{\mu}g/mL$ against Cram positive bacteria, and $75.8\sim113.8{\mu}g/mL$ against Gram negative bacteria in liquid medium, It was found to show stronger bactericidal action against Gram negative bacteria than Cram positive bacteria. According to increasing concentrations of the extract, it resulted in a proportional reduction of viable cell counts of both S. iniae and L. anguillarum. The former was not detected by addition of $189.6{\mu}g/mL$ after 12 hours incubation and the latter by addition of $151.6{\mu}g/mL$ after 24 hours incubation, respectively. It was reasonable that fish diet was soaked in cinnamon bark extract for ten minutes. The relationship formula between the weight of fish diet and the extract absorbed to fish diet was Y=7.2726X+4.5083 ($R^2=0.9998$). The fish diet soaked in the extract inhibited the growth of all strains used in this study. Its antibacterial activity was stable at the range from $10^{\circ}C\;to\;35^{\circ}C$ during the storage period of 28 days. When the diet soaked in the extract was incubated in liquid medium at $35^{\circ}C$, it inhibited the growth of microorganisms inhabited in the diet.

  • PDF

Physico-Chemical Factors on the Growth of Cochlodinium polykrikoides and Nutrient Utilization (Cochlodinium polykrikoides의 성장에 미치는 물리$\cdot$화학적 요인과 영양염 이용)

  • KIM Hyung Chul;LEE Chang Ku;LEE Sam Geun;KIM Hak Gyoon;PARK Chung Kil
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.34 no.5
    • /
    • pp.445-456
    • /
    • 2001
  • In the 1990s, Cochlodinium polykikoides red tide has been annually occurred in the southern coast of Korea and caused the mass damage to the fisheries with a huge amount of economic loss. The present study was done to establish the biological foundation for the elucidation of the mechanism of C. polykikoiaes red tide. The growth response of C. polykikoides to physico-chemical factors such as temperature, salinity, pH, and light intensity were examined using axenic cultures to evaluate the relative importance of these factors on the dynamics of natural populations, It was found that the highest growth conditions were $25^{\circ}C,\;40\%_{\circ}$, pH 7.5, and 7,500 lux, respectively. The tolerable salinity range of growth was relatively wide at an optimum temperature and was reduced to a much narrower range at a sub-optimum temperature. These findings indicate that C. polykikoides is an eurythermal and euryhaline organism. The organism demanded higher light intensity and oceanic pH narrow in its growth. C. polykikoides utilize inorganic nutrients, such as nitrate and ammonium as N, and phosphate as P. The nutritional requirements of C. polykikoides were $40{\mu}M$ for nitrate, $50{\mu}M$ for ammonium, and $5{\mu}M$ for phosphate. The half saturation constant (Ks) for growth was $2.10{\mu}M$ for nitrate, $1.03{\mu}M$ for ammonium, and $0.57{\mu}M$ for phosphate. These values were comparatively smaller than those of other dinoflagellates reported previously. We confirmed that the organism is characterized as an eutrophic species. However, ammonium Ks value is smaller than that of other eutrophic species, This result indicates that C. polykikoides red tide may outbreak in the waters which eutrophication is in progress rather than eutrophicated waters. C. polykikoides preferred ammonium better than nitrate as a nitrogen source when in a growth stage, Therefore, our results indicate that ammonium is more important nutrient on the growth of the organism in comparison with other inorganic nutrients and C. polykikoides red tide is related with the increased ammonium concentration in the coastal waters.

  • PDF

Analysis of health habit and hair mineral nutrition status of media addicted adolescent (미디어중독 청소년의 스마트폰 사용의존도에 따른 건강습관 및 모발 무기질 영양상태 분석)

  • Lim, Hee-Sook;Kim, Soon-Kyung
    • Journal of Nutrition and Health
    • /
    • v.51 no.4
    • /
    • pp.295-306
    • /
    • 2018
  • Purpose: Koreans' internet and smartphone usage hours are steadily increasing and the dependence of young people on smartphones is causing social problems. Therefore, this study was conducted to examine health and dietary habits, as well as hair mineral contents according to the level of dependence of smartphone use among adolescents to clarify the interrelation of smartphone dependence, lifestyle, dietary behavior, and mineral nutrition status. Methods: A total of 80 smartphone-addicted adolescents participated in this study and were divided into three groups (general, potential and danger group) according to smartphone dependence. The subjects' lifestyles and dietary behaviors were then surveyed, and hair mineral contents were analyzed. Results: Higher smartphone dependence was associated with lower average weekly sleeping time and later first smoking age. In the danger group, the rate of eating fast and the rate of snacking twice a day was also relatively high. Parents (45.0%) and mobile (30.0%) were the factors having the greatest influence on an individual's dietary behavior. In the hair mineral analysis, all subjects had lower selenium concentrations and higher lead concentrations than normal. In addition, the levels of aluminum in the danger group were higher than in the normal range and the highest among the three groups. Conclusions: It is necessary to guide adolescents to use smartphones correctly and manage dietary habits. In addition, careful attention is needed the mineral nutritional status of smartphone-addicted adolescents.

Improvement of Small Wetland and Stream in Cultivated Area in point of Landscape Ecology (경작지 내 소규모 습지 및 소하천의 경관생태적 개선방안)

  • Cho, Hyun-Ju;Ra, Jung-Hwa;Kim, Jin-Hyo
    • Current Research on Agriculture and Life Sciences
    • /
    • v.29
    • /
    • pp.11-19
    • /
    • 2011
  • This research gives weight to establish practical improvement based on analysis of the landscape ecological character and value to realize the importance of small wetland and stream in cultivated areas functioning as a residual landscape element in rural landscape and to deal with ecological depression effectively. The results of summary are as follows. 1) The results of landscape ecological character analysis of wetlands biotop in total of 7 sites, for example, size of surface in site 5 was widely formed about $10,600m^2$, which was assessed satisfactory in terms of slope of waterfront, width of hedgerow, vegetation condition of composition and so on. Also, The number of flexibility showed 2 in site 8-1, the highest, and morphological diversity showed 1.47, the highest. 2) The results of problem analysis of wetland biotop, most of wetlands are analyzed that the width of hedgerow was below 1m. Also, the 4 wetlands in site 8 are appeared that hard to live slope vegetation in there because of slope of waterfronts are above $45^{\circ}$. 3) The results of landscape ecological character analysis of stream in total of 6 sites, for example, width of waterfront in site 4 showed 55m, the widest, and investigated consist of natural ingredients such as soil, rock, gravel. However, width of waterfront in site 2-2 showed 4m, the narrowest, and inclined angle of slope was formed a right angle. 4) The results of problem analysis of stream, width of waterfront hedgerow in site 2-1 showed about 5m, which was very narrower than width of waterfront, and toxic chemicals discharged from near cultivated area without any filtering. Also, all areas of site 2-2 was formed concrete, and was assessed dissatisfactory in terms of capacity of nature purification, flood control, habitat living space because of straight stream. 5) Based on the result above landscape ecological character and problem analysis, main improvement guidelines are set in terms of shape, vegetation, topography in case of wetlands, and which are set in terms of vertical, horizontal structure in case of stream.

  • PDF

A Study on Satisfaction level with Herbal Public Health Services and its Improvement Plans (한방공중보건서비스 만족도와 개선방안)

  • Lee, Jae-Won;Koo, Jin-Suk;Seo, Bu-Il
    • Korean Journal of Oriental Medicine
    • /
    • v.18 no.2
    • /
    • pp.65-89
    • /
    • 2012
  • Objective : In order to investigate and improve public Korean medical health service satisfaction level, this study was designed. Method : A questionnaire has been conducted on 212 patients who received treatments at six public health centers in the northern part of Gyeongbuk during 15 days between Sep. 24 and Oct. 8, 2011. Result : 1. An Investigation on the usage of herbal clinics in public health centers reveals that 63.7% have received three times or more medical treatments previously and 61.8% have had their illness treated at other medical institutions. In regard to illness 32.1% have had arthritis or muscle aches. 50.9% have taken insurance medication after having had treatments at the public health centers. 66% have assessed acupuncture and moxa cautery the most satisfying. 2. To a question regarding whether herbal health treatment costs higher than that of physician's, the highest response at 31.6% is 'No'. And to a question regarding whether herbal medicines administered at public health centers have more side effects than that of physician's, the highest response at 39.6% is 'No'. 3. To a question regarding whether herbal treatment of public health centers has little effect against acute disease, 48.1% of responses are 'Fair'. To a question regarding whether herbal treatments, when compared with physician's treatments, boost better recovery of patients, 48.1% of responses are 'Fair'. To a question regarding whether herbal medicine is unscientific, when compared with that of western medicine, 38.2% of responses are 'Fair', To a question regarding whether herbal medicine has faster effect on disease than western medicine, 41.0% of responses are 'Fair'. To a question regarding whether herbal medicine is more effective on disease prevention and promotion of health than disease treatment, 38.2% of responses are 'Fair'. And to a question regarding whether the lack of various types of physical therapy devices in herbal medicine, when compared with western medicine causes inconvenience in herbal treatment, 42.0% of responses are 'Fair'. Those responses take up highest portion at each questionnaire. 4. A comparative study between herbal treatments and physician's treatments has also been conducted. To questions regarding which one of the two considering types of disease is the better, responses are the latter accounted for 43.9% against 'Cancer', the latter accounted for 45.3% against 'Endocrine disorders', the former accounted for 30.7% against 'Psychiatric disorders', the latter accounted for 38.2% gainst 'Otolaryngological(ENT) disease', the former accounted for 47.6% against 'Post traumatic stress disorder', and the former accounted for 52.4% against 'Muscle-skeletal disease'. 5. An investigation on frequency of patients' visits via (p<0.05) of subjects show a statistically significant difference. 6. First, an investigation on frequency of reasons of medical treatments reveal that age, occupation, monthly income, and insurance type (p<0.05) of subjects show a statistically significant difference. Secondly, an investigation on frequency of subjects taking insurance medicines after herbal health treatments reveal that monthly income (p<0.05) of subject shows a statistically significant difference. 7. First, an investigation on frequency of a claim that herbal treatments of public health center does not have great effect on acute disease reveals that age, education, and insurance type (p<0.05) of subjects show a statistically significant difference. Secondly, an investigation on frequency of analysis that herbal treatments has faster effect on disease compared with western treatments reveals that education level, religion, monthly income, and insurance type (p<0.05) of subjects show a statistically significant difference. 8. When herbal clinics of public health centers and general herbal medicine institutions are compared, a survey on additional treatments that herbal clinics need the most reveals that education level, monthly income, and insurance type (p<0.05) of subjects show a statistically significant difference. Secondly, an investigation on frequency of subjects who want various forms of herbal medicines reveals that occupation and insurance type (p<0.05) of subjects show a statistically significant difference. Conclusion : In order to improve efficiency of treatments and enhance patient's satisfaction level, this study suggests measures such as providing a differentiated acupuncture treatments as a whole, streamlining an reception procedure, adopting more elaborated computer system for a patient to get proper medical attention, standardizing a treatment duration in order for a maximum result, keeping regular office hours, and optimizing a consultation time for a patient.

Effect of Dietary Anti-oxidant Supplementation on Telomere Length and Egg Quality in Laying Hens (산란계에 항산화물질 급여가 텔로미어 함량 및 난질에 미치는 영향)

  • Lee, M.H.;Lee, S.H.;Kim, Y.J.;Ko, Y.H.;Jang, I.S.;Moon, Y.S.;Choi, Y.H.;Sohn, S.H.
    • Korean Journal of Poultry Science
    • /
    • v.35 no.3
    • /
    • pp.267-274
    • /
    • 2008
  • There are many kinds of anti-oxidant materials in natural plant resources. The Siberian ginseng and Eucommia are well known as anti-oxidant and medicinal plants. To investigate the effect of their anti-oxidant-like activity on telomere quantity and egg quality, diets containing Siberian ginseng leaf and Eucommia leaf at 0.5% and 1% were given Hyline Brown commercial laying hens during two periods of age: 20 to 30 wks and 60 to 70 wks. The amount of telomere in lymphocyte, liver, ovary, heart and lung was analyzed by quantitative fluorescence in situ hybridization using telomeric DNA probe. Egg weight, albumin height, Haugh unit, egg yolk color, egg shell color, egg shell thickness, egg shell weight and egg shell density were measured to analyze egg quality. The chickens consuming diets Siberian ginseng and Eucommia had higher telomeric DNA in lymphocytes than control chickens in younger layers whereas no significant differences were detected in all target cells analyzed from older layers. Egg quality was increased in younger hens with dietary supplementation as determined by egg weight, albumin height and Haugh unit but there were no effects in older hens. These results imply that dietary supplementation of Siberian ginseng and Eucommia in layers improves bio-activity and egg quality at early laying stage.

Potential Element Retention by Weathered Pulverised Fuel Ash : II. Column Leaching Experiments (풍화 석탄연소 고형폐기물(Pulverised Fuel Ash)의 중금속 제거가능성 : II. 주상용출실험)

  • Lee, Sanghoon
    • Economic and Environmental Geology
    • /
    • v.28 no.3
    • /
    • pp.259-269
    • /
    • 1995
  • Column leaching tests were conducted using fresh and weathered pulverised fuel ash of some 17 and 40 years old from two major British power plants, with deionised water and simulated synthetic industrial leachate. The former was to see the leaching behaviour of weathered ash and the latter was to see if the formation of secondary products from water and PFA interaction and ameliorating effect in removing metals from industrial leachates. Fresh PFA liberates elevated concentrations of surface-enriched inorganics, including Ca, Na, K, B, $Cr_{total}$, Li Mo, Se and $SO^{2-}_4$. This might indicate their association with the surface of PFA particles. In the column leaching tests using weathered ash and deionised water, elements are not readily leached but are released more slowly, showing relatively constant concentrations. For the case of weathered ash, some readily soluble surface-enriched elements appears to have been liberated in their early stage of leaching and the liberation of glass associated elements are thought to be more important function in controlling the element concentration. The result from column leaching tests exceed for a number of elements when compared with various Water Standards and suggests the leachate from PFA disposal mound needs dilution to achieve target concentrations. PF A shows element retention effect for many elements, including B, Fe, Zn, Hg, Ni, Li and Mo, in the order of fresh Drax ash > weathered Drax ash > Weathered Meaford ash in retaining capacity. Geochemical modelling using a computer program WATEQ4F reveals some solubility controlling secondary solid products. These include $CaSO_4{\cdot}2H_2O$ for Ca, $Al(OH)_3$ for Al and $Fe(OH)_3$ for Fe.

  • PDF

Physicochemical Variation by Weathering Degree of Granite from the Mireuksaji Temple Stone Pagoda, Iksan, Korea (익산 미륵사지석탑 화강암의 풍화에 의한 물리화학적 특성변화)

  • Yang, Hee-Jae;Han, Min-Su;Kim, Sa-Dug;Lee, Chan-Hee
    • Journal of Conservation Science
    • /
    • v.23
    • /
    • pp.11-24
    • /
    • 2008
  • A physical characteristics and chemical compositions change by weathering on the granite were examined for the conservation treatment of the Mireuksaji temple stone pagoda. The natural weathered granite was collected from the Mt. Mireuk, and divided into the classification standards based on weathering degrees and strength measured by rock-test hammer. The results from comparison of the strength measured by undestructive rock-test hammer and the strength values converted from ultrasonic velocity showed that each strength measurement value was proportionate. The water absorption of the sample was 1.68 to 0.20%. The F-type of fresh rock was not naturally saturated and the WW-type was naturally saturated but took quite a long time. The water absorption was increased gradually in order of SW-type, the MW-type and the HW-type according to weathering condition. The CW-type samples showed the highest water absorption among the weathered classification samples. Through dyeing test, it was found out that only the feldspar was dyed out of the F-type and the WW-type. The SW-type and the MW-type were distinguished by the fact that plagioclase being dyed. And dyed area was expanded to quartz crack in HW-type and CW-type. Physical change by weathering of the rock-forming minerals could be classified with 3 grades. Through the XRD analysis, albite among the rock-forming mineral showed remarkable decrease. SEM-EDX analysis of the component change in the rock-forming minerals such as biotite, plagioclase, and orthoclase, showed that in case of highly-weathered grade samples compared with fresh samples, contents of the $Al_2O_3$, $K_2O$, $Na_2O$ increase and CaO, MgO decrease in the biotite, the CaO, $K_2O$ increase and $Na_2O$ decrease in the plagioclase, the $Al_2O_3$ a little increase and $K_2O$, $Na_2O$ decrease in the orthoclase. The results of extracted cation analysis using the powder samples of each weathering grade, the CaO, $Na_2O$, $K_2O$ and MgO are highly chemical variations in rock forming minerals and positive variation show high in the weathering grade of the WW-type and CW-type. This research will be used as an importance data to establish a plan for conservation treatment of composed stone in the Mireuksaji temple stone pagoda.

  • PDF