• Title/Summary/Keyword: LT$_{50}$

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Cold Tolerance of Ground Cover Plants for Use as Green Roofs and Walls (옥상 및 벽면녹화용 지피식물의 내한성 비교)

  • Ryu, Ju Hyun;Lee, Hyo Beom;Kim, Cheol Min;Jung, Hyun Hwan;Kim, Ki Sun
    • Horticultural Science & Technology
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    • v.32 no.5
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    • pp.590-599
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    • 2014
  • This study was conducted to compare the cold tolerance of seven ground cover species, Orostachys japonica, Sedum oryzifolium, S. kamtschaticum 'SG1', S. reflexum, S. rupestre 'Blue Spruce', S. spurium 'Green Mental', and S. takesimense, which have been used for green roof and wall systems in Korea. Plants were grown in 10-cm pots and 1 g of tissues at stem-end and crown of each species were kept under either light or dark condition, respectively. For cold tolerance tests, plants were initially left at $4^{\circ}C$ and linearly cooled to 0, -4, -8, -12, -16, and $-20^{\circ}C$ at $-2^{\circ}C{\cdot}h^{-1}$ rate. Low temperature injury and regrowth rates were visually evaluated and assessed by image analysis, respectively. The lethal temperature ($LT_{50}$) of plant species was determined using electrolyte leakage measurements. S. reflexum was the most cold tolerant, showing the most survival at $-16^{\circ}C$, whereas S. oryzifolium and S. takesimense showed low temperature injury at $-8^{\circ}C$. Similar results were found with electrolyte leakage measurements at the stem end. For each species, the crown (Mean $LT_{50}:\;-12.15^{\circ}C$) was more cold tolerant than the stem end (Mean $LT_{50}:\;-10.47^{\circ}C$). In conclusion, S. reflexum and S. rupestre 'Blue Spruce' are recommended for planting in the central region of Korea during late fall and early winter, as they were more cold tolerant and showed more vigorous regrowth than the other tested plant species.

Comparison study of intensity modulated arc therapy using single or multiple arcs to intensity modulated radiation therapy for high-risk prostate cancer

  • Ashamalla, Hani;Tejwani, Ajay;Parameritis, Ioannis;Swamy, Uma;Luo, Pei Ching;Guirguis, Adel;Lavaf, Amir
    • Radiation Oncology Journal
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    • v.31 no.2
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    • pp.104-110
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    • 2013
  • Purpose: Intensity modulated arc therapy (IMAT) is a form of intensity modulated radiation therapy (IMRT) that delivers dose in single or multiple arcs. We compared IMRT plans versus single-arc field (1ARC) and multi-arc fields (3ARC) IMAT plans in high-risk prostate cancer. Materials and Methods: Sixteen patients were studied. Prostate ($PTV_P$), right pelvic ($PTV_{RtLN}$) and left pelvic lymph nodes ($PTV_{LtLN}$), and organs at risk were contoured. $PTV_P$, $PTV_{RtLN}$, and $PTV_{LtLN}$ received 50.40 Gy followed by a boost to $PTV_B$ of 28.80 Gy. Three plans were per patient generated: IMRT, 1ARC, and 3ARC. We recorded the dose to the PTV, the mean dose ($D_{MEAN}$) to the organs at risk, and volume covered by the 50% isodose. Efficiency was evaluated by monitor units (MU) and beam on time (BOT). Conformity index (CI), Paddick gradient index, and homogeneity index (HI) were also calculated. Results: Average Radiation Therapy Oncology Group CI was 1.17, 1.20, and 1.15 for IMRT, 1ARC, and 3ARC, respectively. The plans' HI were within 1% of each other. The $D_{MEAN}$ of bladder was within 2% of each other. The rectum $D_{MEAN}$ in IMRT plans was 10% lower dose than the arc plans (p < 0.0001). The GI of the 3ARC was superior to IMRT by 27.4% (p = 0.006). The average MU was highest in the IMRT plans (1686) versus 1ARC (575) versus 3ARC (1079). The average BOT was 6 minutes for IMRT compared to 1.3 and 2.9 for 1ARC and 3ARC IMAT (p < 0.05). Conclusion: For high-risk prostate cancer, IMAT may offer a favorable dose gradient profile, conformity, MU and BOT compared to IMRT.

Effect of Water Temperature Condition on Growth and Survival of Juvenile Geoduck (Panopea japonica A. Adams, 1850) (사육 수온이 코끼리조개 Panopea japonica (A. Adams, 1850) 치패의 성장과 생존에 미치는 영향)

  • Nam, Myung-Mo;Lee, JooYoung;Lee, Chu;Kang, Hee Woong;Kim, Young Dae;Byun, Soon-Gyu;Yoo, Hae-Kyun
    • The Korean Journal of Malacology
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    • v.31 no.4
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    • pp.263-266
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    • 2015
  • This study was performed to determine the effect of water temperature condition on survival rate and growth of juvenile geoduck (Panopea japonica). Panopea japonica juveniles were bred for 6 weeks at 12, 15, 18, 21, 24 and $27^{\circ}C$ on incubator. Juveniles median lethal times (LT50) were 29 hours in $27^{\circ}C$, 14.5 day in $24^{\circ}C$, 37.4 day in $21^{\circ}C$. Survival rate of water temperature 12, 15 and $18^{\circ}C$ showed a high survival rate in 95.0%, 95.0% and 93.3% at 6 weeks. As a result of culturing for 6 weeks at 12, 15, 18, 21 and $24^{\circ}C$, a daily growth of shell length and total weight was 0.10 mm, 0.12 mm, 0.13 mm, 0.16 mm and 0.14 mm, and 2.21 mg, 2.65 mg, 2.84 mg, 3.13 mg and 2.93 mg. Juvenile shell length and total weight have significantly increased at $15-21^{\circ}C$. However, mortality rate has significantly increased at more than $21^{\circ}C$. As a result, appropriate water temperature for juveniles culturing considered $15-18^{\circ}C$.

Correlates of Lymphedema in Women with Breast Cancer: a Case Control Study in Shiraz, Southern Iran

  • Honarvar, Behnam;Sayar, Negin;Tahmasebi, Sedigheh;Zakeri, Zeinab;Talei, Asra;Rostami, Sara;Khademi, Sahar;Sarvestani, Amene Sabzi;Sekhavati, Eghbal
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.81-85
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    • 2016
  • Globally, the burden of breast cancer (BC) continues to increase. BC related lymphedema (BCRL) is currently non curable and as a life time risk it affects at least 25% of BC patients. Knowing more about BCRL and appropriate control of its modifiable risk factors can improve quality of life (QOL) of the affected patients. In this case control study to detect factors, 400 women with BCRL (as the case group) and 283 patients with BC without lymphedema (as the control group) that were referred to Shiraz University of Medical Sciences affiliated BC clinic center were assessed. The data were analyzed in SPSS. The mean age of the case group was $52.3{\pm}11.0years$ and of the control group was $50.1{\pm}10.9years$. In patients with BCRL, 203(50.7%) had left (Lt) side BC and in non- lymphedema group 151 (53.3%) had Lt side BC. Out of all BCRL patients, 204 (51%) had lymphedema in all parts of their affected upper extremities, 100 (25%) had swelling in the arm and forearm and 23 (5.7%) had edema in both the upper extremity and trunk. Edema, heaviness, concern about changing body image, pain and paresthesia were the most common signs/symptoms among patients with BCRL. In BCRL patients, the difference of circumference between the affected upper limb and non-affected limb was $4.4{\pm}2.5cm$ and the difference in volume displacement was $528.7{\pm}374.4milliliters$. Multiple variable analysis showed that moderate to severe activity (OR; odds ratio =14, 95% CI :2.6-73.3), invasiveness of BC (OR =13.7, 95% CI :7.3-25.6), modified radical mastectomy (OR=4.3, 95% CI :2.3-7.9), BMI =>25 (OR=4.2, 95% CI :2-8.7), radiotherapy (OR=3.9, 95% CI :1.8-8.2), past history of limb damage (OR=1.7, 95% CI :0.9-3.1) and the number of excised lymph nodes (OR=1.06, 95% CI :1.02-1.09) were the significant predictors of lymphedema in women with BC. Modifiable risk factors of BCRL such as non-guided moderate to severe physical activity, high BMI and trauma to the limb should be controlled as early as possible in BC patients to prevent development of BCRL and improve QOL of these patients.

Temperature and Salinity Tolerance of the Manila Clam, Ruditapes philippinarum (바지락 (Ruditapes philippinarum)의 온도 및 염분 내성)

  • SHIN Yun-Kyong;KIM Yoon;CHUNG Ee-Yung;HUR Sung-Bum
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.3
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    • pp.213-218
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    • 2000
  • Tolerance on temperature and salinity of Ruditapes philippinarum was investigated in five different salinity, $32.0,\;25.6,\;19.20,\;12.80,\;6.40,\;3.20{\%_{\circ}}$ with increasing continuously $1^{\circ}C/day 2^{\circ}C/day\;and\;3^{\circ}C/day$ water temperature. R. philippinarum was acclimated to $18^{\circ}C\;and 25^{\circ}C$ before the experiment. Oxygen consumption rates and filtration rates of R. philippinarum were estimated during the experiment. $LT_{50}$ of two stocks acclimated to $18^{\circ}C\;and\;25^{\circ}C$ were similar. However, the maximum tolerance temperature of a stock acclimated $18^{\circ}C\;was\;36^{\circ}C$ while a stock acclimated $25^{\circ}C\;was\;37^{\circ}C$. This suggested that the higher water temperature a stock acclimated, the higher tolerance a stock showed, The surival rates of R. philippina겨m with the changes in salinities decreased below $19,2\;{\%_{\circ}}\;at\;18^{\circ}C\;and\;25^{\circ}C$. Oxygen consumption rates in the experimental group acclimated at $18^{\circ}C$ reduced with decreasing of salinity concentrations, while those of the experimental group acclimated at $25^{\circ}C$ showed irregular trend. Filtration rates revealed the maximum at 24{\~}28^{\circ}C$ in the experimental group acclimated ai $18^{\circ}C\;and\;31{\~}33^{\circ}C\;in\;those\;at\;25{\circ}C$. Filtraton rates shanty decreased at the lower salinity concentrations.

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Establishment of Analytical Method for Propylene Glycol Alginate in Food Products by Size-exclusion Chromatography (Size-exclusion chromatography법에 의한 식품 중 알긴산프로필렌글리콜 분석법 확립)

  • Jeong, Eun-Jeong;Choi, Yoo-Jeong;Lee, Gunyoung;Yun, Sang Soon;Lim, Ho Soo;Kim, Yong-Suk
    • Journal of Food Hygiene and Safety
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    • v.32 no.5
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    • pp.404-410
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    • 2017
  • An analytical method for determination of propylene glycol alginate (PGA) in food products was developed by HPLC-size-exclusion chromatography. The GF-7M HQ column and LT-ELSD detector were determined by considering the instrumental analysis conditions for PGA analysis. The pretreatment method for the analysis of PGA was suitable for 3 hr extraction at $20^{\circ}C$ and 150 rpm according to the extraction temperature. Linearity ($R^2$) for the analysis of PGA was 0.9873 at calibration curve range of 300, 500, 700, 1,000, and 1,500 mg/kg (5 points). The limit of detection and limit of quantification of PGA on HPLC system was 171.43 and 519.50 mg/kg, respectively. The accuracy and coefficient of variation obtained by size-exclusion chromatography were 86.1~110.4% and 4.1~13.5%, respectively. By applying the HPLC-size-exclusion chromatography system, it was possible to analyze the contents of PGA in 134 different types of food products.

Survival, Hematologic and Histological Changes of File Fish Thamnaconus modestus Adult Exposed to Different Lower Temperature (저수온에 노출된 말쥐치 Thamnaconus modestus의 생존율, 혈액학적 및 조직학적 반응)

  • Kim, Hae Jin;Lee, Hee-Jung;Kim, Won Jin;Shin, Yun Kyung
    • Korean Journal of Ichthyology
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    • v.31 no.4
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    • pp.201-207
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    • 2019
  • Temperature is one of the most important criteria considered in species preference for aquaculture. Acute drop in temperature during winter is a cause of disease and mass mortality in farmed fish. This study was carried out the low water temperature tolerance, oxygen consumption, hematologic and histological responses to use as basic data for the management of fish farming which frequently cause death due to winter water temperature drop. Low-lethal water temperature for 4 days of file fish Thamnaconus modestus (4day-LT50) was 6.97℃ (6.69~7.27℃). Oxygen consumption rate decreased with decreasing water temperature, showing a significant difference between water temperatures. SOD activity increased significantly at 6℃ experimental group than control group (10℃) (p<0.05), but CAT did not show any significant difference between experimental temperatures (p>0.05). Cortisol increased with decreasing experimental water temperature compared to control group. Histological changes in the liver include decreased blood vessels in the blood vessels, proliferation of acid cells, condensation of the nucleus, atrophy of pancreatic exocrine gland cells, and enzyme source granules.

Time Synchronization Algorithm using the Clock Drift Rate and Reference Signals Between Two Sensor Nodes (클럭 표류율과 기준 신호를 이용한 두 센서 노드간 시간 동기 알고리즘)

  • Kim, Hyoun-Soo;Jeon, Joong-Nam
    • The KIPS Transactions:PartC
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    • v.16C no.1
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    • pp.51-56
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    • 2009
  • Time synchronization algorithm in wireless sensor networks is essential to various applications such as object tracking, data encryption, duplicate detection, and precise TDMA scheduling. This paper describes CDRS that is a time synchronization algorithm using the Clock Drift rate and Reference Signals between two sensor nodes. CDRS is composed of two steps. At first step, the time correction is calculated using offset and the clock drift rate between the two nodes based on the LTS method. Two nodes become a synchronized state and the time variance can be compensated by the clock drift rate. At second step, the synchronization node transmits reference signals periodically. This reference signals are used to calculate the time difference between nodes. When this value exceeds the maximum error tolerance, the first step is performed again for resynchronization. The simulation results on the performance analysis show that the time accuracy of the proposed algorithm is improved, and the energy consumption is reduced 2.5 times compared to the time synchronization algorithm with only LTS, because CDRS reduces the number of message about 50% compared to LTS and reference signals do not use the data space for timestamp.

The Effect of TBT Toxicity on Survival and Growth of Olive Flounder, Paralichthys olivaceus (넙치 생존과 성장에 미치는 TBT의 독성)

  • TAK Keon-Tae;KIM Joong Kun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.2
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    • pp.103-108
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    • 2001
  • Toxic effect of TBTO on larva flounder was studied by the use of a food-chain system in which indirect toxicity from seawater or/and plankton can be measured, Under the treatment of 0.5 ng/L TBTO, the combined effect of diets ( Chlorella and rotifer) and seawater was significant by synergism, although the sole effect from TBTO treated diets or seawater was equally not, The values of $LT_{50}$ from results of acute-toxicity experiments for juvenile flounder were estimated to be 230.0, 48.0, 24.0, 14.6, 9.3 5.5 3.0 and 1.7 hr at 1, 10, 25, 50, 100, 250, 500 and 1000 ng/L of TBTO, respectively, and $96hr-LC_{50}$ was 3.5 ng/L. From the above results, the experiments for chronic toxicity of TBTO was executed at the concentration range of $1\sim10 ng/L$. In long-term experiments for four months, the weight and the total length of the juvenile flounder in all TBTO treated experiments slowly increased when compared to control. No significant differences in the growth and survival of the juvenile flounder were found in the treatment of 1 ng/L TBTO(P>0.05), But, $90\%$ of the juvenile flounder died in 20 days under TBTO treated seawater at both concentrations of 5 and 10 ng/L, The TBTO treated on seawater was more effective and significantly different in the growth and survival of the juvenile flounder when compare with that on artificial diets (P<0.05). From the all results, TBTO should be regulated below 5 ng/L in a coast.

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Distributional Characteristics of Fault Segments in Cretaceous and Tertiary Rocks from Southeastern Gyeongsang Basin (경상분지 남동부 일대의 백악기 및 제3기 암류에서 발달하는 단층분절의 분포특성)

  • Park, Deok-Won
    • The Journal of the Petrological Society of Korea
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    • v.27 no.3
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    • pp.109-120
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    • 2018
  • The distributional characteristics of fault segments in Cretaceous and Tertiary rocks from southeastern Gyeongsang Basin were derived. The 267 sets of fault segments showing linear type were extracted from the curved fault lines delineated on the regional geological map. First, the directional angle(${\theta}$)-length(L) chart for the whole fault segments was made. From the related chart, the general d istribution pattern of fault segments was derived. The distribution curve in the chart was divided into four sections according to its overall shape. NNE, NNW and WNW directions, corresponding to the peaks of the above sections, indicate those of the Yangsan, Ulsan and Gaeum fault systems. The fault segment population show near symmetrical distribution with respect to $N19^{\circ}E$ direction corresponding to the maximum peak. Second, the directional angle-frequency(N), mean length(Lm), total length(Lt) and density(${\rho}$) chart was made. From the related chart, whole domain of the above chart was divided into 19 domains in terms of the phases of the distribution curve. The directions corresponding to the peaks of the above domains suggest the directions of representative stresses acted on rock body. Third, the length-cumulative frequency graphs for the 18 sub-populations were made. From the related chart, the value of exponent(${\lambda}$) increase in the clockwise direction($N10{\sim}20^{\circ}E{\rightarrow}N50{\sim}60^{\circ}E$) and counterclockwise direction ($N10{\sim}20^{\circ}W{\rightarrow}N50{\sim}60^{\circ}W$). On the other hand, the width of distribution of lengths and mean length decrease. The chart for the above sub-populations having mutually different evolution characteristics, reveals a cross section of evolutionary process. Fourth, the general distribution chart for the 18 graphs was made. From the related chart, the above graphs were classified into five groups(A~E) according to the distribution area. The lengths of fault segments increase in order of group E ($N80{\sim}90^{\circ}E{\cdot}N70{\sim}80^{\circ}E{\cdot}N80{\sim}90^{\circ}W{\cdot}N50{\sim}60^{\circ}W{\cdot}N30{\sim}40^{\circ}W{\cdot}N40{\sim}50^{\circ}W$) < D ($N70{\sim}80^{\circ}W{\cdot}N60{\sim}70^{\circ}W{\cdot}N60{\sim}70^{\circ}E{\cdot}N50{\sim}60^{\circ}E{\cdot}N40{\sim}50^{\circ}E{\cdot}N0{\sim}10^{\circ}W$) < C ($N20{\sim}30^{\circ}W{\cdot}N10{\sim}20^{\circ}W$) < B ($N0{\sim}10^{\circ}E{\cdot}N30{\sim}40^{\circ}E$) < A ($N20{\sim}30^{\circ}E{\cdot}N10{\sim}20^{\circ}E$). Especially the forms of graph gradually transition from a uniform distribution to an exponential one. Lastly, the values of the six parameters for fault-segment length were divided into five groups. Among the six parameters, mean length and length of the longest fault segment decrease in the order of group III ($N10^{\circ}W{\sim}N20^{\circ}E$) > IV ($N20{\sim}60^{\circ}E$) > II ($N10{\sim}60^{\circ}W$) > I ($N60{\sim}90^{\circ}W$) > V ($N60{\sim}90^{\circ}E$). Frequency, longest length, total length, mean length and density of fault segments, belonging to group V, show the lowest values. The above order of arrangement among five groups suggests the interrelationship with the relative formation ages of fault segments.