• Title/Summary/Keyword: Density fluctuation

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Effects of Photobiomodulation Therapy on Glycemic and Lipid Profiles In Vitro

  • Hakami, Abdulrahim R.;Alasmari, Sultan;Makkawi, Mohammed;Mansour, Adel Abo;Ahmad, Irfan;Shahrani, Mesfer Al;Alkhathami, Ali;Dera, Ayed A.;Tedla, Jaya Shanker;Almane, Saleh;Abudahish, Abdulaziz;AbuHadhyah, Jawaher;Alshehri, Majed;Mansour, Hanan Abo;Saad, Manar
    • Medical Lasers
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    • v.9 no.2
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    • pp.172-178
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    • 2020
  • Background and Objectives This study aimed at examining the effects of photobiomodulation therapy (PBMT) on glucose, cholesterol, triglycerides, and low- and high-density lipoprotein (LDL and HDL, respectively) levels in vitro. Materials and Methods A total of 38 serum samples collected in plain (n=10) and heparinized tubes (n=28) were subjected to PBMT at 60 Joules (J)/cm2 for 2 min at 810 nm. The glucose and lipid profiles, cholesterol, triglycerides, LDL, and HDL of each sample was measured before and after PBMT. Results A statistically significant increase in glucose levels was observed in the PBMT-sera in 8 out of 10 samples in plain tubes. However, only two samples that were prepared in heparinized tubes showed an increase in glucose levels. The remaining heparinized samples that were exposed to PBMT presented lower glucose values. The treated sera exhibited a fluctuation in the lipid profiles after PBMT. However, high cholesterol levels were evident following PBMT. Similar trends with HDL and LDL in heparinized tubes were evident. Conclusion Together, the findings suggest that photobiomodulation exhibits an effect on glycemic and lipid profiles in vitro. Hence, the use of low-level laser therapy could have therapeutic potential. However, the differences between individual responses appear to indicate that the impact of PBMT may not always be beneficial.

Cosmetic Efficacy of Supercritical Cannabis sativa Seed Extracts and Enhancement of Skin Permeation (초임계 대마종자 추출물의 화장품 효능과 경피흡수증진 효과)

  • Lee, Kwang Won;Park, Shinsung;Park, Su In;Shin, Moon Sam
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.4
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    • pp.683-691
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    • 2021
  • The purpose of this study is to measure the yield and to evaluate the physiological activity of Cannabis sativa seed(Hemp seed) extracts extracted using a density fluctuation supercritical carbon dioxide for each temperature condition-30℃(HSSE30), 45℃(HSSE45), 60℃(HSSE60), and to enable dissolution of the poorly water-soluble extracts by liposome formulation and to enhance the skin permeability. As a result of the yield measurement, HSSE60 showed the highest yield, and in the antioxidant activities, HSSE45 had the highest total polyphenol content, and showed the highest DPPH, ABTS+ radical scavenging activities at the highest concentration of the extracts. As a result of the antimicrobial susceptibility testing, a clear zone appeared only in the Propionibateium acnes strain. It was confirmed that particle size was reduced and the absolute value of the zeta potential increased in the case of the formulation in which the extracts were in liposomes than in the formulation in which the extracts were dissolved in deionized water, and the skin permeability was improved. Based on these experimental results, we confirmed the possibility of using the hemp seed supercritical carbon dioxide extracts, a poorly water-soluble extract, can be applied as a functional natural material for cosmetics.

A Study on the Combustion Characteristics of the Crown of Pine Trees in the Drying Season (건조기 소나무 수관부 부위별 연소특성에 관한 연구)

  • Hyuk Kwon;Jong Ho Lee
    • Journal of the Korean Society of Safety
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    • v.38 no.4
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    • pp.39-46
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    • 2023
  • Pine trees, which account for 23% of the forested area of the Republic of Korea, are highly vulnerable to fire in comparison to broad-leaved trees due to the presence of consistent water tube sections throughout the year and resin that is composed of approximately 20% oil. In addition, the pattern of forest fires is determined by weather, topographic conditions, and fluctuation in moisture content. Therefore, when fire breaks out in pine tree forests during the dry season (January to March), it is difficult to extinguish, and it quickly spreads. In this study, the combustion characteristics of pine needles, pine cones, and pine branches in the water tube sections of living pine trees were compared and analyzed in accordance with the moisture content as per the ISO 5660-1. The monthly moisture content was analyzed from January to March, and it was found to be the lowest in March, with 53.6% for pine needles, 51.9% for pine branches, and 10.9% for pine cones. In particular, pine cones were more vulnerable to fire as compared to pine needles and pine branches because their moisture content was more than five times lower than that of pine needles and branches. The ignition time, which affects the speed of flame propagation, was the most rapid in March, and the fastest ignition time was for pine cones, at 19 seconds, followed by 34 seconds for pine needles, and 256 seconds for pine branches. The pine branches were the last to be ignited due to the effect of density, according to the thickness and specific gravity of the specimen. The peak heat release rate, which is a measurable index of fire intensity, was analyzed for pine cones and found to be 184.28 kW/m2 , while the mean effective heat of combustion was 19.79 MJ/kg, and the total heat release rate was 39.7 MJ/m2 , and these values were higher than those of pine branches and pine needles. Thus, we determined that the flame propagation speed and fire intensity according to the moisture content can be used to evaluate the risk of fire to the water tube section of pine trees. It is suggested that because of the combustion characteristics of the pine cone in March, that is when the forest is most vulnerable to fires.

Examining Diurnal Thermal Variations by Urban Built Environment Type with ECOSTRESS Land Surface Temperature Data: Evidence from Seoul, Korea (도시 건조환경 유형에 따른 서울시 주간 지표면 온도 변동성 분석: ECOSTRESS 데이터의 활용)

  • Gyuwon Jeon;Yujin Park
    • Journal of the Korean Regional Science Association
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    • v.40 no.2
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    • pp.107-130
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    • 2024
  • Urban land surface temperature (LST) change is a major environmental factor that affects the thermal comfort, energy consumption, and health of urban residents. Most studies that explored the relationship between LST and urban built-environment form analyzed only midday LST. This study explores the diurnal variation of summertime LST in Seoul using ECOSTRESS data, which observes LST at various times of the day and analyzes whether the LST variation differs by built environment type. Launched in 2018, ECOSTRESS operates in a non-sun-synchronous orbit, observing LST with a high resolution of 70 meters. This study collected data from early morning (6:25) to evening (17:26) from 2019 to 2022 to build time-series LST. Based on greenery, water bodies, and building form data, eight types of Seoul's built environment were derived by hierarchical clustering, and the LST fluctuation characteristics of each cluster were compared. The results showed that the spatial disparity in LST increased after dawn, peaked at noon, and decreased again, highlighting areas with rapid versus stable LST changes. Low-rise and high-rise compact districts experienced fast, high temperature increases and high variability, while low-density apartments experienced moderate LST increases and low variability. These results suggest urban forms that can mitigate rapid daytime heating.

Community Structure of Macrobenthic Assemblages around Gijang Province, East Sea of Korea (동해 기장군 주변해역에 서식하는 대형저서동물의 군집구조)

  • Kim, Dae-Ik;Seo, In-Soo;Moon, Chang-Ho;Choi, Byoung-Mi;Jung, Rae-Hong;Son, Min-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.16 no.2
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    • pp.97-105
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    • 2011
  • This study investigated the community structure and spatio-temporal variation of macrobenthic assemblages around Gijang Province, East Sea of Korea. Macrobenthos collected seasonally using a modified van Veen grab sampler from March to November 2006. A total of 157 macrobenthic fauna were collected. The overall average macrobenthos density were $552 \;ind/m^2$. The species number of macrobenthos was in the range from 62 in winter and spring to 122 in autumn. On the other hand, abundance fluctuated between 6,540 (in spring) and 17,920 (in autumn) inds./$18m^2$. Cluster analysis and non-metric multi-dimensional scaling (nMDS) were applied to assess the spatio-temporal fluctuation in the macrobenthic assemblages. Cluster analysis and nMDS ordination analysis based on the Bray-Curtis similarity identified 3 station groups. The group 1 (station 8~10, 12, 13, 17 and 18) was characterized by high abundance of the polychaete Lumbrineris longifolia, the bivalve Ennucula tenuis and the Amphipoda spp., with mean phi range from $6.2{\Phi}$ to $7.1{\Phi}$ (above 50m water depth). The group 2 (station 5~7, 11, 14~16) was numerically dominated by the po1ychaete Ampharete arctica and the bivalve Theorafragilis (mean phi: $6.0{\sim}7.0{\Phi}$; within 40 m water depth). Finally group 3 (station 1~4) was characterized by high density of the polychaetes Magelona japonica and Sternaspis scutata, with mean phi range from $3.5{\Phi}$ to $6.9{\Phi}$ (below 30 m water depth). In conclusion, the Macrobenthic community structure showed a distinct spatial and temporal trend, which seemed to be related to the water depth and sediment composition.

Effect of an Offshore Fish Culture System on the Benthic Polychaete Community (외해가두리 양식이 저서다모류군집에 미치는 영향)

  • Jung, Rae-Hong;Yoon, Sang-Pil;Kim, Youn-Jung;Lee, Won-Chan;Hong, Sok Jin;Park, Sung-Eun;Oh, Hyung Taik
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.4
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    • pp.195-205
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    • 2013
  • Excessive input of organic matters from fish cage farming has been considered as one of the major factors disturbing benthic ecosystem, especially in semi-enclosed coastal waters. Recently offshore aquaculture in the vicinity of Jeju-do has been introduced to minimize that kind of negative impact. This study was conducted to investigate the ecological impacts of offshore aquaculture on the macrobenthic polychaete communities. A total of ten sampling works were carried out for 28 months, spanning from 10 days after starting giving feed to 3 months after stopping giving feed. During the study period, mean current velocity was quite strong with the range of 50 cm/s to 70 cm/s. TOC of surface sediment was constantly low. Significant changes in polychaete community were detected just three months after starting giving feed, which were the increase of the number of species and density at all stations. Up to 18 months after the start of farming, the amount of feed provided played an important role in the fluctuation of the number of species and density, especially at 0 m and 10 m stations. After reducing the amount of feed provided, dominance of some opportunistic species within 10 m distance from fish cages still lasted to the end of aquaculture. However, opportunistic species disappeared 3 months after the end of farming, which indicated the sign of recovery from the disturbance. From these results, the amount of food input and the period of cultivation were critical factors disturbing polychaete community and ensuing changes in this offshore and oligotrophic waters as well. In addition, study on the changes of polychaete community structure before and after fish farming showed more detailed changes in benthic ecological state than geochemical approach did.

APPROXIMATE ESTIMATION OF RECRUITMENT IN FISH POPULATION UTILIZING STOCK DENSITY AND CATCH (밀도지수와 어획량으로서 수산자원의 가입량을 근사적으로 추정하는 방법)

  • KIM Kee Ju
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.8 no.2
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    • pp.47-60
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    • 1975
  • For the calculation of population parameter and estimation of recruitment of a fish population, an application of multiple regression method was used with some statistical inferences. Then, the differences between the calculated values and the true parameters were discussed. In addition, this method criticized by applying it to the statistical data of a population of bigeye tuna, Thunnus obesus of the Indian Ocean. The method was also applied to the available data of a population of Pacific saury, Cololabis saira, to estimate its recuitments. A stock at t year and t+1 year is, $N_{0,\;t+1}=N_{0,\;t}(1-m_t)-C_t+R_{t+1}$ where $N_0$ is the initial number of fish in a given year; C, number o: fish caught; R, number of recruitment; and M, rate of natural mortality. The foregoing equation is $$\phi_{t+1}=\frac{(1-\varrho^{-z}{t+1})Z_t}{(1-\varrho^{-z}t)Z_{t+1}}-\frac{1-\varrho^{-z}t+1}{Z_{t+1}}\phi_t-a'\frac{1-\varrho^{-z}t+1}{Z_{t+1}}C_t+a'\frac{1-\varrho^{-z}t+1}{Z_{t+1}}R_{t+1}......(1)$$ where $\phi$ is CPUE; a', CPUE $(\phi)$ to average stock $(\bar{N})$ in number; Z, total mortality coefficient; and M, natural mortality coefficient. In the equation (1) , the term $(1-\varrho^{-z}t+1)/Z_{t+1}$s almost constant to the variation of effort (X) there fore coefficients $\phi$ and $C_t$, can be calculated, when R is a constant, by applying the method of multiple regression, where $\phi_{t+1}$ is a dependent variable; $\phi_t$ and $C_t$ are independent variables. The values of Mand a' are calculated from the coefficients of $\phi_t$ and $C_t$; and total mortality coefficient (Z), where Z is a'X+M. By substituting M, a', $Z_t$, and $Z_{t+1}$ to the equation (1) recruitment $(R_{t+1})$ can be calculated. In this precess $\phi$ can be substituted by index of stock in number (N'). This operational procedures of the method of multiple regression can be applicable to the data which satisfy the above assumptions, even though the data were collected from any chosen year with similar recruitments, though it were not collected from the consecutive years. Under the condition of varying effort the data with such variation can be treated effectively by this method. The calculated values of M and a' include some deviation from the population parameters. Therefore, the estimated recruitment (R) is a relative value instead of all absolute one. This method of multiple regression is also applicable to the stock density and yield in weight instead of in number. For the data of the bigeye tuna of the Indian Ocean, the values of estimated recruitment (R) calculated from the parameter which is obtained by the present multiple regression method is proportional with an identical fluctuation pattern to the values of those derived from the parameters M and a', which were calculated by Suda (1970) for the same data. Estimated recruitments of Pacific saury of the eastern coast of Korea were calculated by the present multiple regression method. Not only spring recruitment $(1965\~1974)$ but also fall recruitment $(1964\~1973)$ was found to fluctuate in accordance with the fluctuations of stock densities (CPUE) of the same spring and fall, respectively.

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Changes of water Quality During the Seed Production Period of Dark-banded Rockfish Sebastes inermis in Large Scale Tanks (대형 수조에서 볼락 종묘 생산에 따른 수질 환경의 변화)

  • Oh, Sung-Yong;Noh, Choong-Hwan
    • Journal of Aquaculture
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    • v.19 no.1
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    • pp.25-32
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    • 2006
  • An experiment was carried out to investigate changing of water quality during the seed production of dark-banded rockfish Sebastes inermis in large scale tanks. Ten broodstock of dark-banded rockfish were held in three circular tanks (diameter 6.5 m; depth 2 m; water volume 50 ton) each (stocking density $0.061kg/m^3$). During the experiment the temperature ranged from 14.2 to $16.1^{\circ}C$. The fingerlings were 134 with rotifers only during 1 to 9 days after parturition, rotifers with Artemia nauplii during 10 to 20 days after parturition, Artemia nauplii only during 21 to 35 days after parturition, Artemia nauplii with commercial diet during 36 to 80 days after parturition and commercial diet only during 81 to 85 days after parturition. Water quality (dissolved oxygen, pH, $NH_4^+-N,\;NO_2^--N,\;NO_3^--N\;and\;PO_4^{3-}-P$) in rearing tanks measured every 5 days in long term monitoring investigation or every 2 hours in diurnal monitoring investigation. In 85 days after parturition, the body weight of fish grew up to 0.88 f and specific growth rate was 8.0%/day in body weight. In long term monitoring investigation, with the increase of the amount of supplied commercial diet, the concentration of dissolved oxygen (DO) and pH decreased, but the concentration of $NH_4^+-N\;(4.5\;to\;76.3{\mu}M),\;NO_2^--N\;(0.02\;to\;0.06{\mu}M),\;NO_3^--N\;(3.0\;to\;5.9{\mu}M)$, and $PO_4^{3-}-P\;(0.41\;to\;0.59{\mu}M)$ increased. In the diurnal monitoring investigation, the concentration of $NH_4^+-N$ showed great fluctuation and ranged from 3.0 to $9.1{\mu}M$ when fed rotifers, 16.3 to $45.8{\mu}M$ when fed Artemia nauplii and 36.5 to $120.1{\mu}M$ when fed commercial diet. After daily feeding with each of feed, the amount of dissolved inorganic nitrogen (DIN) and phosphorus (P) wastage were 7.0 g and 0.7 g when fed rotifers, 24.7 g and 0.7 g when fed Artemia nauplii and 140.9 g and 2.2 g when 134 commercial diet. The amount of DIN and phosphorous wastage during 134 commercial diet was significantly higher than that of fed rotifer and Artemia nauplii (P<0.05). Results will provide valuable information far water quality management and culture of dark-banded rockfish in commercial seed production systems.

Collection of Adult and Larval Mosquitoes in U.S. Army Compounds in the Republic of Korea During 1979~1983 (한국에 주둔한 미군지역내에서의 모기 성충과 유충 채집(1979~1983))

  • ;R.K
    • Parasites, Hosts and Diseases
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    • v.22 no.1
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    • pp.102-108
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    • 1984
  • This paper is the result of adult female mosquito and larval collection in U.S. Army Installations in Korea from 1979 to 1983. New Jersey light traps were operated for adult collection from May to October. The primary concern of this surveillance is to determine when to recommend insecticide spraying for mosquito control in the Army areas. The 5th Preventive Medicine Unit have developed an "index" level of female mosquitoes in a light trap similar to other U.S. Army Agencies in other parts of the world. When 10 female mosquitoes are reached on two consecutive trap-night, or 5 known vector females are collected, fogging is recommended in the trap areas. 1. Mosquito collections were conducted in 12 U.S. Army areas by operating 39 New Jersey light traps. Mosquitoes collected from the areas were identified to be 17 species comprising 3 genera. Anopheles sinensis (40%), Culex tritaeniorhynchus (31%), Aedes vexans nipponii (19 %) and Culex pipiens pallens (10%) appeared to be the most common species in the areas. 2. The species, population density and monthly appearance of adult mosquitoes were found to be almost the same in the all provinces involved. And Japanese Encephalitis vector mosquitoes, Culex tritaeniorhynchus, showed their seasonal fluctuation from July to September with a peak in August each year. 3. Larval habitats confirmed in the Army areas were categorized into 16 types as shown in Table 3. The mosquito larvae collected in those habitats were identified to be 15 species representing 4 genera. Most breeding sites in the Army areas were those which are activated during the wet season. 4. More mosquitoes were collected from the Kyungki Province than from the other Provinces. The reason for more collection of mosquitoes from military installations in the Kyungki Province appears to be the geographic characteristics surrounded by rice fields, marshes and other stagnant water areas.

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Variations of Temperature and Salinity in Kugum Suro Channel (거금수로 해역의 수온과 염분의 변동)

  • CHOO Hyo-Sang;LEE Gyu-Hyong;YOON Yang-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.2
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    • pp.252-263
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    • 1997
  • Temperature and salinity were observed in Kugum Suro Channel in February, April, August and October 1993. Temperature ranged from $7.0^{\circ}C\;to\;25.0^{\circ}C$ throughout the year and its variation was about $18^{\circ}C$. The maximum temperature difference between surface and bottom was less than $0.75^{\circ}C$ for a year, which meant that the temperature stratification in Kugum Suro Channel was considerably week. Salinity had also a small variation range of less than $0.5\%_{\circ}$. Salinity varied from $34.0\%_{\circ}$ in April to $30.0\%_{\circ}$ in August and its fluctuation patterns were quite similar to the seasonal variations of the precipitation and the duration of sunshine observed at Kohung Weather station. Seasonal variation of sea water density in T-S diagram showed that the water mass in Kugum Suro Channel could be largely affected by regional atmospheric conditions. Temperature increased in ebb tide and decreased in flood tide, but salinity decreased in ebb tide and increased in flood tide for a day. The period of fluctuations in temperature and salinity measured for 25 hours was nearly coincident with the semi-diurnal tide which was predominant in that region. Stratification parameters computed in Kugum Suro Channel areas were less than $4.0J/m^3$ the year round, which indicated that vortical mixing from the bottom boundary caused by tidal current played an important role in deciding the stratification regime in Kugum Suro Channel. In estimating the equation which defines stratification and mixing effects in the observed areas, the tidal mixing term ranged from $4.7J/M^3\;to\;14.1J/m^3$ was greater than any other terms like solar radiation, river discharge and wind mixing.

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