• Journal of Environmental Science International
• /
• v.29 no.7
• /
• pp.761-772
• /
• 2020

This research investigated the meteorologically relevant characteristics of high PM_2.5 episodes in Busan. The number of days when daily mean PM₁₀ concentration exceeded 100 ㎍/㎥ and the PM_2.5 concentration exceeded 50 ㎍/㎥ over the last four years in Busan were 24 and 58, respectively. Haze occurrence frequency was 37.6% in winter, 27.4% in spring, 18.6% in fall, and 16.4% in summer. Asian dust occurrence frequency was 81.8% in spring, 9.1% in fall and winter, and 0% in summer. During summer in Busan, high PM_2.5 episode occurred under the following meteorological conditions. 1) Daytime sea breeze. 2) Mist and haze present throuout the day. 3) Anti-cyclone located around the Korean peninsula. 4) Stable layer formed in the lower atmosphere. 5) Air parcel reached Busan by local transport rather than by long-range transport. These results indicate that understanding the meteorological relevance of high PM_2.5 episodes could provide insight for establishing a strategy to control urban air quality.

• Korean Journal of Veterinary Research
• /
• v.43 no.2
• /
• pp.311-314
• /
• 2003

Pacheco's disease (PD) is a highly contagious, acute disease of psittacines caused by a herpesvirus. Five 56-day-old dead parakeets (Neophema bourkii) were submitted to the National. Veterinary Research & Quarantine Service for diagnosis. At necropsy, principle lesions were seen in the pancreas, which were hard, whitish, nodular and atrophic resulting in distortion of the duodenal loop. Histologically, lymphocytic pancreatitis with eosinophilic intranuclear inclusions syncytium-formed acinar epithelium was prominent. In the brain, marked focal gliosis and perivascular lymphocytic cuffing were observed. On the electron microscopy examination, various forms of viral particles were found in both the nucleus and cytoplasm of acinar epithelium of pancreas, identified as a herpesvirus. These results were suggested that the cases were diagnosed as PD in the parrakeet.

• Journal of Chest Surgery
• /
• v.40 no.6 s.275
• /
• pp.407-413
• /
• 2007

Background: The brain natriuretic peptide (BNP) level has been reported in some studies to be associated with the occurrence of atrial fbrillation (AF). The aim of this study is to evaluate the potential usefulness of the BNP level as a predictor of the occurrence of postoperative (postop) AF and to assess the relationship of the BNP level with the onset of AF and the restoration of sinus rhythm. Material and Method: From January 1, 2005 to February 28, 2006, 82 patients without a history of atrial arrhythmia that had undergone cardiac surgery were enrolled in the study. Blood samples for plasma BNP were drawn daily for all these patients from the preoperative (preop) day to the 7th postop day. The patient records were reviewed and postop EKGs were checked daily for AF until the time of discharge. Result: Patients were divided into two groups based on development of postop AF. Postoperative AF developed in 26 patients (31.7%). There was no significant statistical difference in age, sex distribution, preop left ventricle ejection fraction, hypertension, left ventricular hypertrophy, or the use of beta blockers between the non-postop AF and postop AF group. More patients in the AF group had undergone valve surgery (39.3% versus 76.9%, p=0.002). The preop left atrium size was significantly larger in the AF patients ($43.8{\pm}10.3 mm$ versus $49.8{\pm}11.5 mm$, p=0.029). The preop plasma BNP levels were higher in the postop AF patients ($144.1{\pm}20.8 pg/mL$ versus $267.5{\pm}68 pg/mL$, p=0.034). In the postop AF group, the plasma BNP level was the highest on the 3rd postop day. Postop AF developed in most patients by the 3rd postop day; restored sinus rhythm developed by the 7th postop day. Conclusion: Elevated plasma BNP levels may lead to the occurrence of postop AF in patients undergoing cardiac surgery. Patients who have a high risk of postop AF should be considered for aggressive prophylactic antiarrhythmic therapy.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• v.4 no.3
• /
• pp.127-137
• /
• 2000

This study presents an analysis of the characteristics of vertical ozone distribution near the surface using ozonesonde data(l995 to 1998), plus surface ozone and meteorological data from the Pohang region. These features were examined in detail using three case studies. The first related to episodes of high surface ozone concentrations during the Spring season when the frontogenesis between the high and low pressure associated with the upper-level jet stream was found to be located near the surface. The second was a 5-day winter period(l3 -17 December, 1997) in the Pohang province when the hourly concentrations exceeded 90 ppb on several occasions owing to low-level jets(LLJs) induced by a nocturnal stable layer. Accordingly, this explains why the high surface ozone concentrations occurred at night as the ozone was transported across the zone by a strong wind speed( over 12.5 ms .1). The third case study was ozone enhancement due to photochemical reactions. In this case, the maximum concentration of ozone exceeded 60 ppb in the summer(23 -28 August, 1997). When an ozone peak appeared within the boundary layer, the occurrence frequency of a low-level jet due to the nocturnal stable layer was about 77%, similarly the occurrence frequency of a near-surface ozone peak relative to the appearance of an LLJ was about 76%. Accordingly, there is clearly a close correlation between the occurrence of LLJs and near-surface ozone peaks.

• Atmosphere
• /
• v.25 no.3
• /
• pp.389-405
• /
• 2015

In this study, the occurrence circumstances of 3 cases (12 Jan 2006, 11 Jan 2008, 22 Feb 2009) when the freezing rain was observed at more than two observatories in a day with more than three times each observatory, were investigated. Following the advanced study about the same cases, we have tried to find more delicate differences in using the Korea Local Analysis and Prediction System (KLAPS; 5 km reanalysis data) that has the smallest grid scale at current situation. As results, three common characteristics are found: (1) Just before the occurrence of the freezing rain, the wind direction was consistently continuous and the wind speed was constant or gradually increased for at least 3 hr more. (2) Surface air temperature (Relative humidity) was respectively $3.08^{\circ}C$ (28.76%), $0.47^{\circ}C$ (50.07%) and $-3.60^{\circ}C$ (71.07%) 3 hr ago to break out the freezing rain. It means the freezing rain occurs in a wide range of atmospheric environments. However, the closer it got to the occurrence time of the freezing rain, the closer the surface air temperature was to $0^{\circ}C$, and the bigger the humidity of the surface air was. (3) The liquid precipitation formed in the upper atmosphere, met a cold advection bellower than 950 hPa level and suspected to be changed to the super-cooled condition.

• Journal of the East Asian Society of Dietary Life
• /
• v.18 no.3
• /
• pp.397-404
• /
• 2008

The purpose of this study was to help promote the consumption of rice by substituting rice powder for wheat flour in bread preparation and examining the effect of rice powder particle size in baked rice bread samples. Several experiments were carried to analyze and compare the quality characteristics of prepared samples of wheat flour and rice powder breads. The loaf volume index of the wheat flour bread was 6.34, and the indices of the rice powder bread samples, which were made from powder milled through 20, 35, and 45 mesh (S1, S2 and S3), were 5.37, 5.56, and 5.85, respectively. These data indicated that the loaf volume index of the rice powder bread was lower than that of the wheat flour bread, but the volume of the rice powder bread increased as the particle size of the rice powder became finer. According to texture analysis results using a rheometer, the hardness value of the wheat flour bread was $1.34{\times}10^3\;g/cm^2$, and values of S1, S2, and S3 were $1.74{\times}10^3\;g/cm^2$, $1.57{\times}10^3\;g/cm^2$, and $1.47{\times}10^3\;g/cm^2$, respectively. Therefore, S3, which was made from the finest powder among the rice powder samples, showed the lowest level of hardness. No significant differences were observed for springiness, cohesiveness, and gumminess among the bread samples. However, the wheat flour and rice powder breads had significant differences for bread crumb color. The L-value of S3(76.20) was similar to that of the wheat flour bread(77.22). but the L-values of S1(70.30) and S2(71.21) were lower than that of the wheat flour bread. In terms of redness and yellowness, the values of the rice powder breads were significantly different from those of the wheat flour bread. In terms of overall preference, the sensory evaluation results indicated that S3 was significantly the more preferred and the wheat flour bread was the least preferred among the bread samples. This study also investigated texture changes and mold occurrence in bread samples stored at $25^{\circ}C$ for 5 days. From the 3rd day of storage, bread texture became harder in all samples however, S3 showed the least level of change among the rice powder breads. The occurrence of mold began to increase abruptly from the 4th day of storage, and S2 and S3 showed mold numbers that were 2-fold greater than those of S1 and the wheat flour bread.

• Journal of Veterinary Clinics
• /
• v.22 no.2
• /
• pp.141-143
• /
• 2005

The preventive effects of calcium gluconate injection and administration of anion feed on occurrence rates of the abomasal displacement and retained placenta were examined from 86 pregnant cows reared in Paju and Goyang cities in Gyunggi Province. The cows were divided into 3 groups: control (30 heads), experimental group I (28 heads) and experimental group II (28 heads), respectively. The control cows were not treated at all. The cows in experimental group I were intravenously injected with calcium gluconate(CMPK, Am. Tech. Canada, 10 g/head). The cows in experimental group II were given with the anion feed (Goyang TMR, Korea, 9 kg/head/day). The occurrence rates of the abomasal displacement in experimental groups were lower than that of control group and experimental group revealed the lowest prevalence rate, however, significance was not detected. The occurrence rate of retained placenta in experimental groups revealed lower prevalence than that of control group and experiment group II showed the lowest prevalence rate(p<0.01). Considering the above findings collectively, it was thought that administration of anion feeds was affective for prevention of the bovine retained placenta during drying milk period.

• Korean Journal of Environmental Biology
• /
• v.31 no.3
• /
• pp.204-212
• /
• 2013

This study analyzed the occurrence of tunic softness, survival rate, metabolic rate and histopathologic changes arising from the effect of hypoxic environment in order to find the causes of occurrences of tunic softness, which manifests as the key phenomenon of mass mortality of Halocynthia roretzi. Regarding the survival of H. roretzi with reduction in dissolved oxygen, all the entities died on the 4th day of exposure to the dissolved oxygen concentration of $2mg\;L^{-1}$ while 50% mortality was observed on the 5th day of exposure to the dissolved oxygen concentration of $3mg\;L^{-1}$. Therefore the 5 days-$LC_{50}$ was found to be $3.55mg\;L^{-1}$ (1.86~$4.96mg\;L^{-1}$). However, occurrence of tunic softness was not observed during the period of exposure to low oxygen concentration. The oxygen consumption rate significantly decreases at the dissolved oxygen concentration of less than $5mg\;L^{-1}$ in comparison to the control group. Therefore, it is presumed that H. roretzi controls the respiration rate for prescribed period of time when exposed to hypoxic environment. Regarding the histopathologic changes in the gill, digestive gland and cyst of H. roretzi due to hypoxic environment, necrosis of epithelial layer, in filtration of blood cells, and condensation of nucleus that compose each of the organs were observed. Regarding morphological changes, the decrease in volume with shrinking of the tunic, discoloration of the internal organs and necrosis of gill and hepatopancreas were observed.

• Journal of Animal Science and Technology
• /
• v.59 no.4
• /
• pp.7.1-7.13
• /
• 2017

Background: Selenium is one of the trace minerals whose deficiency is known to lead to complications of female reproduction. The identified gaps in researches regarding selenium and pregnancy include optimizing the dosage of selenium supplementation, timing of supplementation, finding the best form and type of selenium, and selenium administration combined with other antioxidants. Hence, this study was conceptualized to address one of the identified gaps, that is, to find out the best timing of selenium administration around the time of pregnancy. Specifically, this study aimed to assess the effects of maternal Selenium-supplementation, administered at various stages of periconception period, on murine blastocyst morphology, percent occurrence of good quality blastocysts, and implantation status. Methods: ICR female mice were randomly assigned into the unsupplemented group (Group I) receiving basal diet without selenium, and treatment groups given with $3.0{\mu}g$ selenium-supplement per day during pregestation only (Group II), pregestation-throughout-gestation (Group III) and gestation only (Group IV). Both blastocyst morphology and implantation status were assessed. Results: The morphometric measurements of blastocysts appeared to be unaffected by selenium-supplementation at different stages of periconception. Selenium-supplementation at pregestation only (Group II) and gestation only (Group IV) produced higher percent occurrence of good quality blastocysts and lower percent pre-implantation loss than Group III. Among all the treatment groups, Group III (Selenium-supplementation during pregestation-to-gestation) yielded the lowest quality blastocysts and highest percent pre-implantation loss. Conclusion: Maternal selenium-supplementation during pregestation and gestation stages of the periconception period yielded a high percent occurrence of good quality blastocysts and pre-implantation success.

• Korean journal of applied entomology
• /
• v.33 no.3
• /
• pp.173-177
• /
• 1994

his study was conducted to Investigate the occurrence of small brown planthopper (SBPH), LaodeIpahx striatellus Fallen, and the ind~cence 01 rice virus diseases by d~fferent seeding dates in dryseeded rice. The occurrerlce of SBPH was the highest an nce seeded in May 11, followed byMay 1, May 21 and May 31. However. SBPH dld not occur on the rice seeded in June 10 duelo the rice was emerged after peak occurrence of first generailon adult of SBPH. The occurrenceof the first generation adult of SBPH was May 11 and it was 3-day earlier than that of infantnce transplanting. The ~nd~cencofe rice vlrus diseases, rice stripe vilus (RSV) and rice black-streakeddwarf virus (RBSDV), was the most severe at seeding date May 11. and then followed by May1, May 21 and May 31 Thus the incidence of "ce virus diseases was closely related with thedensity of the first generat~on adult of SBPH Rice yield was decreased by later seeding dates, although rice yield from May 1 to May 21 was relatively stable and hqii compared with laterseeding dates. Accordingly, there was slgniilcant relatlonsh~p between rice yield and seeding datesice yield and seeding dates