• Korean journal of food and cookery science
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• v.13 no.5
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• pp.602-608
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• 1997

The antibacterial activity of low concentrations of clove (Eugenia caryophyllata Thumb) in culture broth against Listeria monocytogenes and Salmonella typhimurium was tested at 35, 5, and -20$^{\circ}C$. Tryptic soy broth (TSB) containing 0∼0.5% (w/v) of clove was inoculated with 10$\^$5/∼10$\^$7/ cell/ml of L. monocytogenes and S. typhimurium and incubated at each temperature. The growth of L. monocytogenes occured only after a prolonged lag period at 0.1% clove at 35$^{\circ}C$, while viabilities of the cells decreased by 1.4 and 3.3 log cycles at 0.3 and 0.5% clove, respectively. Growth of S. typhimurium occured at the presence of 0∼0.5% clove after a longer lag period with increasing concentration of clove at 35$^{\circ}C$. During refrigerated storage at 5$^{\circ}C$, the growth of L. monocytogenes occured after 6 days of lag period at 0.1% clove while viability of the cells were decreased during 24 days of storage. During frozen storage at -20$^{\circ}C$, the viability of L. monocytogenes and S. typhimurium decreased about 4 log cycles during 3 days of early period of storage at 0.1% clove. There were no major changes in the population of L. monocytogenes and S. typhimurium in TSB with different concentrations of clove during frozen storage.

• Sleep Medicine and Psychophysiology
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• v.4 no.1
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• pp.57-65
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• 1997

As jet lag of modern travel continues to spread, there has been an exponential growth in popular explanations of jet lag and recommendations for curing it. Some of this attention are misdirected, and many of those suggested solutions are misinformed. The author reviewed the basic science of jet lag and its practical outcome. The jet lag symptoms stemed from several factors, including high-altitude flying, lag effect, and sleep loss before departure and on the aircraft, especially during night flight. Jet lag has three major components; including external de synchronization, internal desynchronization, and sleep loss. Although external de synchronization is the major culprit, it is not at all uncommon for travelers to experience difficulty falling asleep or remaining asleep because of gastrointestinal distress, uncooperative bladders, or nagging headaches. Such unwanted intrusions most likely to reflect the general influence of internal desynchronization. From the free-running subjects, the data has revealed that sleep tendency, sleepiness, the spontaneous duration of sleep, and REM sleep propensity, each varied markedly with the endogenous circadian phase of the temperature cycle, despite the facts that the average period of the sleep-wake cycle is different from that of the temperature cycle under these conditions. However, whereas the first ocurrence of slow wave sleep is usually associated with a fall in temperature, the amount of SWS is determined primarily by the length of prior wakefulness and not by circadian phase. Another factor to be considered for flight in either direction is the amount of prior sleep loss or time awake. An increase in sleep loss or time awake would be expected to reduce initial sleep latency and enhance the amount of SWS. By combining what we now know about the circadian characteristics of sleep and homeostatic process, many of the diverse findings about sleep after transmeridian flight can be explained. The severity of jet lag is directly related to two major variables that determine the reaction of the circadian system to any transmeridian flight, eg., the direction of flight, and the number of time zones crossed. Remaining factor is individual differences in resynchmization. After a long flight, the circadian timing system and homeostatic process can combine with each other to produce a considerable reduction in well-being. The author suggested that by being exposed to local zeit-gebers and by being awake sufficient to get sleep until the night, sleep improves rapidly with resynchronization following time zone change.

• Journal of Astronomy and Space Sciences
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• v.28 no.2
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• pp.123-132
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• 2011

It is generally believed that the occurrence of a magnetic storm depends upon the solar wind conditions, particularly the southward interplanetary magnetic field (IMF) component. To understand the relationship between solar wind parameters and magnetic storms, variations in magnetic field polarity and solar wind parameters during magnetic storms are examined. A total of 156 storms during the period of 1997~2003 are used. According to the interplanetary driver, magnetic storms are divided into three types, which are coronal mass ejection (CME)-driven storms, co-rotating interaction region (CIR)-driven storms, and complicated type storms. Complicated types were not included in this study. For this purpose, the manner in which the direction change of IMF $B_y$ and $B_z$ components (in geocentric solar magnetospheric coordinate system coordinate) during the main phase is related with the development of the storm is examined. The time-integrated solar wind parameters are compared with the time-integrated disturbance storm time (Dst) index during the main phase of each magnetic storm. The time lag with the storm size is also investigated. Some results are worth noting: CME-driven storms, under steady conditions of $B_z$ < 0, represent more than half of the storms in number. That is, it is found that the average number of storms for negative sign of IMF $B_z$ (T1~T4) is high, at 56.4%, 53.0%, and 63.7% in each storm category, respectively. However, for the CIR-driven storms, the percentage of moderate storms is only 29.2%, while the number of intense storms is more than half (60.0%) under the $B_z$ < 0 condition. It is found that the correlation is highest between the time-integrated IMF $B_z$ and the time-integrated Dst index for the CME-driven storms. On the other hand, for the CIR-driven storms, a high correlation is found, with the correlation coefficient being 0.93, between time-integrated Dst index and time-integrated solar wind speed, while a low correlation, 0.51, is found between timeintegrated $B_z$ and time-integrated Dst index. The relationship between storm size and time lag in terms of hours from $B_z$ minimum to Dst minimum values is investigated. For the CME-driven storms, time lag of 26% of moderate storms is one hour, whereas time lag of 33% of moderate storms is two hours for the CIR-driven storms. The average values of solar wind parameters for the CME and CIR-driven storms are also examined. The average values of ${\mid}Dst_{min}{\mid}$ and ${\mid}B_{zmin}{\mid}$ for the CME-driven storms are higher than those of CIR-driven storms, while the average value of temperature is lower.

• BMB Reports
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• v.40 no.1
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• pp.100-106
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• 2007

The wound-inducible lipoxygenase obtained from maize is one of the nontraditional lipoxygenases that possess dual positional specificity. In this paper, we provide our results on the determination and comparison of the kinetic constants of the maize lipoxygenase, with or without detergents in the steady state, and characterization of the dependence of the kinetic lag phase or initial burst, on pH, substrate, and detergent in the pre-steady state of the lipoxygenase reaction. The oxidation of linoleic acid showed a typical lag phase in the pre-steady state of the lipoxygenase reaction at pH 7.5 in the presence of 0.25% Tween-20 detergent. The reciprocal correlation between the induction period and the enzyme level indicated that this lag phenomenon was attributable to the slow oxidative activation of Fe (II) to Fe (III) at the active site of the enzyme as observed in other lipoxygenase reactions. Contrary to the lagging phenomenon observed at pH 7.5 in the presence of Tween-20, a unique initial burst was observed at pH 6.2 in the absence of detergents. To our knowledge, the initial burst in the oxidation of linoleic acid at pH 6.2 is the first observation in the lipoxygenase reaction. Kinetic constants (Km and kcat values) were largely dependent on the presence of detergent. An inverse correlation of the initial burst period with enzyme levels and interpretations on kinetic constants suggested that the observed initial burst in the oxidation of linoleic acid could be due to the availability of free fatty acids as substrates for binding with the lipoxygenase enzyme.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.677-683
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• 2017

In this study, we examined responses to Sea Surface Temperature (SST) as the result of an intensive heat wave that took place in August 2016 and the cross correlation between SST and Air Temperature (AT) in August 2016. The data used included the SST of 8 ocean buoys, provided by the National Institute of Fisheries Science, and the AT of AWS near those 8 ocean buoys recorded every hour. To identify an appropriate data period, on FIR filter was applied. Two locations in the south sea were selected to be observed over similar a period, with a high correlation coefficient of about 0.8 and a time lag of about 50 hours between AT and SST. For the yellow sea, due to shallow waters and tidal currents, SST showed a rapid response caused by changes in AT. The east sea showed a negative correlation between AT and SST because of significant water depth and marine environment factors. By identifying the time lag between AT and SST, damage to aquatic organisms can be minimized, and we expect to develop a rapid response system for damage to the fishery industry caused by extreme heat waves.

• Journal of Gastric Cancer
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• v.7 no.1
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• pp.1-8
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• 2007

Purpose: There has been increased the number of early gastric cancer and laparoscopy-assisted gastrectomy (LAG), due to early detection through mass screening program. We started the LAG in April 2004 and performed 119 cases of gastric cancer in 2005, so we report a surgical outcome compared with that of open gastrectomy (OG). Materials and Methods: 119 patients underwent LAG in 2005, and for open group, 126 patiens of early gastric cancer were selected sequentially from January 2005 to March 2005. We compared clinicopathologic characteristics, postoperative courses and complications between two groups. Results: There was no significant difference between age, a length of hospital stay, distal resection margin and a number of retrived lymph nodes. The operation time was longer in LAG group (239.2 vs 123.3 mins, P<0.001) and a diet progression was faster in LAG group (first flatus: 3.05 vs 3.70 days, SOW: 2.86 vs 3.22 days, liquid diet: 3.87 vs 4.19 days, soft diet: 4.84 vs 5.26 days, P<0.001). But there was no difference statistically in postoperative discharge date (7.73 vs 8.25 days, P=0.229). The additional requirement of analgesic injection was less frequent in LAG group (2.97 vs 4.92 times, P<0.001). The harvested lymph nodes were similar in both groups (23.9 vs 23.1, P=0.563). A complication rate was lower in LAG group (4.9% vs 9.5%), but there was no statistical significance (P=0.179). There was no mortality in both groups and no conversion to open gastrectomy in the LAG group. Conclusion: LAG can be performed safely and accepted in view of curative procedure in treatment of early gastric cancer. But we need the follow up of long-term period to evaluate the survival rate and recurrence, and a prospective randomized controlled study should be done to establish that LAG will be a standard operation for early gastric cancer.

• Journal of the Korean Statistical Society
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• v.29 no.1
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• pp.29-44
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• 2000

In this paper, we consider one-level rotation designs with finite rotation groups such that the design satisfies two basic requirements: all rotation groups are included in any given survey period, and overlapping rates depend only on the time lag. First we present the necessary number of rotation groups and a rule for the length of time the sample units are to be in or out of the sample to satisfy the requirements. Second, an algorithm is presented to put rotation groups to proper positions in a panel in order to include all finite rotation groups for any survey period. Third, we define an one-level rotation pattern which is invariant in the survey period and has useful properties in practical sense.

• Korean Journal of Weed Science
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• v.18 no.1
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• pp.69-75
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• 1998

Responses of tobacco(Nicotiana tabacum cv. Xanthi) leaves of different age to diphenyl ether herbicide oxyfluorfen were evaluated with respect to cellular leakage, chlorophyll loss, and membrane lipid peroxidation. When tobacco leaves of different age were incubated under light condition at $25^{\circ}C$ following 12hr dark incubation. Significant electrolyte leakage from the treated tissues into the bathing medium occurred. The change of electrolyte leakage was proportional to the oxytluorfen concentration and the duration of light exposure to the tissues. Electrolyte leakage from the tissues treated with oxyfluorfen was highly dependent on the leaf age. From the tissues of younger age, more electrolyte leakage occurred and lag period was greatly reduced. Chlorophyll loss and membrane lipid peroxidation, as measured by malondialdehyde production, caused by oxyfluorfen treatment were also dependent an the age of treated leaf tissues. In conclusion, physiological responses of tobacco leaves to oxyfluorfen greatly varied with the age of treated tissues, and thus tobacco plants could be used as appropriate materials for studying the mechanisms of tolerance to diphenyl ether herbicides.

• Management & Information Systems Review
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• v.31 no.4
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• pp.287-307
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• 2012

We empirically examine the price discovery dynamics among the VKOSPI, the KOSPI200 spot, and the KOSPI200 futures markets. The analysis employs the vector-autoregression, Granger causality, impulse response function, and variance decomposition using both daily data from 2009. 04. 13 to 2011. 12. 30 and 1 minute data from the bull market, bear market, and the flat period. The main results are as follows; First, the lead lag relationships between KOSPI200 spot(futures) yield VKOSPI returns could not be found from the daily data analysis. But KOSPI200 spot(futures) have a predictive power for VKOSPI from 1 minute data. Especially KOSPI200 spot(futures) and VKOSPI show the bi-directional effects to each other during the return rising period Second, We chose the VAR(1) the model in daily data but adopt the VAR(3) model in the one minute data to determine the lead lag time. We know that there is predictability during the very short period Third, Spot returns and futures returns makes no difference in daily data results. According to the one minite data results, VKOSPI returns have a predictive power for KOSPI200 spot return, but have no predictive power for KOSPI200 futures return.

• Journal of Korea Port Economic Association
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• v.39 no.4
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• pp.43-65
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• 2023

Recently, with the increasing international interest on environmental issues, efforts have been made to reduce greenhouse gas emissions due to ship fuel, however, the dependence on fossil fuel is expected to continue for a while. Since fuel costs account for a high portion of the total operating cost of a ship, it is necessary to analyze the influence of oil prices on the shipping markets. The purpose of this study is to evaluate the relationship between the international oil prices and the four major shipping markets for bulk carriers. This study employed WTI as the oil price variable while monthly data from 2017 to 2020 from the four major shipping markets by classifying freight rates, charter rates, newbuilding prices, and secondhand prices were also considered in multiple ship sizes of capesize, panamax, supramax, and handysize. Firstly, the results of the correlation analysis using the VAR model indicate that changes in international oil prices have a statistically positive (+) significant effect on BCIS only in the second time lag, on BSIS at all lags, and on BHIS only in the first staggered period. Secondly, as a result of correlation analysis using the VECM model, in the case of BPIC, BHIC, BCIN, and BHIR, the cointegration coefficient value has a negative (-) significant effect at the 5% significance level in the cointegration relationship with international oil prices. Further, in the case of the dynamic correlation, the increase in oil price in the first period of the lag leads to a decrease in the BCIN newbuilding prices while the increase in the oil price in the first and second period in the lag leads to a decrease in the BHIR used ship prices.