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Compare radiation dose of lumbar spine epidural steroid injections (ESIs) performed under fluoroscopy guidance and ultralow-dose CT-fluoroscopy guidance. Retrospective review of consecutive lumbar ESIs performed using fluoroscopy, between May 2017 and April 2019, and using ultralow-dose CT-fluoroscopy, between August 2019 and February 2021, was performed. Ultralow-dose CT-fluoroscopy technique omits a planning CT scan, utilizes CT-fluoroscopy, and minimizes radiation dose parameters. Patient characteristics (age, sex, height, weight, body mass index (BMI)), procedural characteristics (anatomic level, type of ESI, procedure time, pain reduction, complications, trainee participation), and radiation dose were compared. Chi-square tests and two-sample t-tests were performed for statistical analysis. One hundred and forty-seven patients (mean age 55.8 ± 16.7; 85 women) underwent ESIs using fluoroscopy. Sixty-six patients (mean age 60.9 ± 16.7; 33 women) underwent ESIs using ultralow-dose CT-fluoroscopy. The effective dose for the fluoroscopy group was 0.30 mSv ± 0.34, compared to 0.15 mSV ± 0.11 for ultralow-dose CT-fluoroscopy (p

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Incidence of Fusarium wilt was surveyed in fields of summer radish in Gangwon province in Korea in 2018 and 2019. The disease started in early July and spread rapidly in hot summer of late July and August and in severe case, reached up to 80% in a field in Gangneung area. Symptoms in the seedling stage include poor growth and browning of internal tissue of root. During mid-growth, the leaves of diseased plant turned yellow over time, the surface of the roots changed from white to blackish, and the vascular tissues turned brown. A total of 23 isolates was obtained from the diseased plants and identified as Fusarium oxysporum f. sp. raphani by elongation factor-1a and intergenic spacer sequence analysis. Pathogenicity of the isolates was tested by artificial inoculation to the radish and other plants. All the isolates tested were pathogenic to radish plant, although there were differences in virulence on radish 11 cultivars. However, the isolates were not virulent to other plants except some cruciferous vegetables including Brussels sprouts, rocket, stock, and turnip. The results of pathogenicity test showed that it is necessary to rotate with crops other than cruciferous vegetables in order to prevent Fusarium wilt from radish fields.

In order to find if a ferulic acid (FA) can be used as a selection index in cereal breeding for resistance to head blight and mycotoxin production, we analyzed FA in the grains of 80 cultivars of barley, rice, and wheat. FA content ranged 1.66-2.77 mg/g in barley (n=20), 0.56-1.53 mg/g in wheat (n=40), and 0.91-2.13 mg/g in rice (n=20). Among these, 7 cultivars each of barley and wheat with different FA content were tested for head blight and mycotoxin production by 2 Fusarium graminearum and 2 F. asiaticum strains. Mean pathogenicity of the wheat cultivars was significantly less than that of barley with higher FA and among wheat cultivars, there was no correlation between FA content and pathogenicity. Mycotoxin production was also lower in the wheat than in the barley as pathogenicity. However, pathogenicity and toxins produced by F. asiaticum were negatively correlated with FA content in barley. These results indicate that FA is not a resistance factor to head blight by F. asiaticum and F. graminearum or its mycotoxin production in barley and wheat.

This study aimed to assess the incidence and distribution of toxigenic fungi in Korean oat. Toxigenic fungi were isolated from oat samples collected from 12 oat fields from heading to harvest in 2017 and 2018. A total of 745 fungal colonies were isolated based on morphology and identified using marker genes. About 92% of the fungal isolates were Fusarium spp. and others were Penicillium (5.9%) and Aspergillus (2.1%). Fusarium isolates comprised mostly of F. asiaticum (83.1%), followed by F. incarnatum (5.4%), F. proliferatum (3.5%), F. fujikuroi (2.8%), F. tricinctum species complex (FTSC) 11 (1.5%) and F. graminearum (1.0%). About 97% of F. asiaticum was nivalenol type, and 3-acetyl deoxynivalenol (3.2%) and 15-acetyl deoxynivalenol (0.4%) types also were found. Pathogenicity test of the selected Fusarium isolates revealed that F. asiaticum isolates have a wide range of virulence depending on the tested plants. F. graminearum and FTSC 11 isolates from blighted spikelets were the most virulent in naked oat. All Fusarium isolates (n=18) except one (FTSC 11) produced nivalenol (0.2–7.6 μg/g), deoxynivalenol (0.03–6.1 μg/g), and zearalenone (0.1–27.0 μg/g) on rice medium. This study is first report that F. asiaticum causes Fusarium head blight disease of oat in Korea. These findings demonstrate the dominance of F. asiaticum in oat agroecosystems as in rice, wheat and barley in Korea.

Fusarium asiaticum of the F. graminearum species complex causes head blight in small-grain cereals. The nivalenol (NIV) chemotypes of F. asiaticum is more common than the deoxynivalenol (DON) chemotypes of F. asiaticum or F. graminearum in Korea. To understand the prevalence of F. asiaticum–NIV in Korean cereals, we characterized the biological traits of 80 cereal isolates of F. asiaticum producing NIV or 3-acetyl-deoxynivalenol (3-ADON), and 54 F. graminearum with 3-ADON or 15-acetyl-deoxynivalenol (15-ADON). There was no significant difference in mycelial growth between the chemotypes, but F. asiaticum isolates grew approximately 30% faster than F. graminearum isolates on potato dextrose agar. Sexual and asexual reproduction capacities differed markedly between the two species. Both chemotypes of F. graminearum (3-ADON and 15-ADON) produced significantly higher numbers of perithecia and conidia than F. asiaticum–NIV. The highest level of mycotoxins (sum of trichothecenes and zearalenone) was produced by F. graminearum–3-ADON on rice medium, followed by F. graminearum–15-ADON, F. asiaticum–3-ADON, and F. asiaticum–NIV. Zearalenone levels were correlated with DON levels in some chemotypes, but not with NIV levels. Disease assessment on barley, maize, rice, and wheat revealed that both F. asiaticum and F. graminearum isolates were virulent toward all crops tested. However, there is a tendency that virulence levels of F. asiaticum–NIV isolates on rice were higher than those of F. graminearum isolates. Taken together, the phenotypic traits found among the Korean F. asiaticum–NIV isolates suggest an association with their host adaptation to certain environments in Korea.

Compare radiation dose of lumbar spine epidural steroid injections (ESIs) performed under fluoroscopy guidance and ultralow-dose CT-fluoroscopy guidance.Retrospective review of consecutive lumbar ESIs performed using fluoroscopy, between May 2017 and April 2019, and using ultralow-dose CT-fluoroscopy, between August 2019 and February 2021, was performed. Ultralow-dose CT-fluoroscopy technique omits a planning CT scan, utilizes CT-fluoroscopy, and minimizes radiation dose parameters. Patient characteristics (age, sex, height, weight, body mass index (BMI)), procedural characteristics (anatomic level, type of ESI, procedure time, pain reduction, complications, trainee participation), and radiation dose were compared. Chi-square tests and two-sample t-tests were performed for statistical analysis.One hundred and forty-seven patients (mean age 55.8 ± 16.7; 85 women) underwent ESIs using fluoroscopy. Sixty-six patients (mean age 60.9 ± 16.7; 33 women) underwent ESIs using ultralow-dose CT-fluoroscopy. The effective dose for the fluoroscopy group was 0.30 mSv ± 0.34, compared to 0.15 mSV ± 0.11 for ultralow-dose CT-fluoroscopy (p 0.001). The average age in the CT-fluoroscopy group was older (p = 0.04), and there was more trainee participation in the fluoroscopy group (p 0.001); otherwise there was no statistically significant difference in patient or procedural characteristics between the conventional fluoroscopy group and the ultralow-dose CT-fluoroscopy group. There was no statistically significant difference in immediate post-procedure pain reduction between the groups (p = 0.16). Four intrathecal injections occurred only in the fluoroscopy group, though this difference was not significant (p = 0.18).Ultralow-dose CT-fluoroscopy technique for image-guided lumbar spine ESIs can lower radiation dose compared to fluoroscopy-guided technique.

We analyzed rice sample with scab (collected in 2017) for fungal occurrence and found that frequency of Fusarium spp. was the highest among fungal genera. Within Fusarium, Fusarium asiaticum-nivalenol type dominated as 79%. Among mycotoxins, zearalenone was the highest toxin detected (1117 ng/g), followed by deoxynivalenol (163 ng/g), 15-acetyl deoxynivalenol (155 ng/g), nivalenol (110 ng/g). Analysis of mycotoxin levels in scabby and healthy grains (collected in 2015) revealed that both grain samples were contaminated with zearalenone. However, level difference of zearalenone between the samples was over 5 times as the scabby samples were 1400-2370 ng/g, while healthy ones were 240-430 ng/g. This result indicates that scabby grains should be removed when harvest to reduce zearalenone contamination in rice.

Fusarium infection rate of the paddy rice grain after harvest seemed to be influenced by the average temperature from late July (before heading) to the end of September (during ripening). In case of 2010 and 2013 in which average temperature of the same period was similar, Fusarium infection was related to cumulative precipitation, cumulative precipitation days, and precipitation durations over two days. The distribution ratio of Fusarium species complex isolated from paddy rice grains after harvest was 57% in 2010 and 45% in 2013 for Fusarium graminearum species complex (FGSC), 35% and 50% for Fusarium incarnatum-equiseti species complex, and 8% and 5% for Fusarium fujikuroi species complex (FFSC). The distribution ratios of FGSC and FFSC were higher in 2010 than 2013. Among the total 26 promoted rice varieties, the ‘Mihyang’ showed resistant response against the natural infection with Fusarium species belonging to FGSC and the varieties of ‘Nampyeong’, ‘Hi-ami’and ‘Younghojinmi’ showed resistant response against the natural infection with overall Fusarium pathogens. Majority of the promoted rice varieties could not be classified for resistance or susceptibility. These results are valuable as basic data to determine the resistance and susceptibility of rice variety against Fusarium spp. infection in the field.

Six representative Korean strains of streptomycetes (S33, S27, S71, S63, S77, and S78) that were pathogenic to potato were characterized based on phenotypic properties, analysis of 16S rRNA genes, production of thaxtomin A, and presence of nec1 and ORFtnp gene homologs. Strains S33 and S27 had typical characteristics of Streptomyces scabies and S. turgidiscabies, respectively, producing thaxtomin A and hybridizing to genes of nec1 and ORFtnp. Strain S71 produced thaxtomin A and had phenotypic and phylogenetic properties similar to those of S. acidiscabies, except having a greater minimum growth pH (4.5), production of a melanoid pigment on tyrosine agar, and failure to hybridize with nec1 and ORFtnp gene probes. In contrast, strains S63, S77, and S78 were phenotypically different from described scab pathogens. Spore colors of strains S63 and S77 were yellow-white or pale orange, respectively, with rectiflexuous chains. Strain S78 had thin and compact spores unlike typical S. acidiscabies (ATCC 49003). Phylogenetic analysis of strains S63, S77, and S78 based on 16S rRNA gene sequences showed low homology to that of described scab pathogens (less than 97.3, 96.0, and 96.3%, respectively). Strain S78 produced thaxtomin A, but did not have homologous sequences to nec1 and ORFtnp genes. Production of thaxtomin A and gene homologs of nec1 and ORFtnp were not detected in strains S63 and S77. All three strains grow at low pH, with minimal growth at pH 3.5 (S77 and S78) or 4.5 (S63). Streptomyces strains S63, S77, and S78 are novel pathogenic streptomycetes adapted to acidic soil conditions in Korea.

Soil bulk density is a key parameter for soil physical property. Much root placed in rhizosphere soil lump, especially in grassland and orchard, makes it difficult to measure soil bulk density. This experiment was carried out to countermeasure the above drawbacks. Volume check apparatus using water-filling method was made of acryl for higher accuracy in bulk density measurement. 10 types of land cover, including bare, tall fescue, rye, and soybean, were used for determining the relationships between root and bulk density. In this study, higher root volume resulted in higher differences in bulk density between in-situ core soil and root-ridded core soil, which indicated the volume check apparatus through water-filling could be useful for increasing the accuracy of bulk density of soils with much root.

Most fields in highland areas are covered with rye or hairy vetch for conservation during a fallow. However, using cover crops needs an effort to sow, and this makes top soil more vulnerable to loss due to surface disturbances. The aims of this study were to develop an automatic seeding-regulator device using a low-price, extensive-use GPS sensors and a DC motors and to evaluate a working efficiency of it after adaptation to partial tillage machine for reducing seeding effort. The amount of runoff water and soil loss was evaluated with partial tillage and simultaneous-seeding after harvesting soybean, in 17% slope lysimeters. In results, the seeding amount with the machine speed was stable between 0.5~0.8 m s -1 of working sections. The automatic control device of seeding-rate could be enough to solve the slip problems of power selecting supply system or five four-wheel drive device. In partial tillage and simultaneous seeding, runoff water was 11.6% (1.8 m³ ha -1 ) of the scatter-seeding control (15.5 m³ ha -1 ) and soil loss was 13.2% (7 kg ha -1 ) of the scatter-seeding control (53 kg ha -1 ). These results suggest that partial tillage and simultaneous-seeding methods are very effective in decreasing work effort and soil loss of sloped land.

The resistance levels of the green peach aphid, Myzus persicae (Sulzer), against 10 insecticides was checked and selecte d the applicable insecticide resistance markers. We conducted our study in 5 cabbage cultivation regions (Pyeongchang, Hongcheon, Bongwha, Muju, and Jeju) of Korea, over 3 successive years (2009 –2011). We selected a multi-resistant (MR) strain from among the 5 field-collected populations. We analyzed esterase over-expression and mutation(s) in the target sites, by using native isoelect ric focusin g(IEF) and quantitative sequencing (QS). We detected esterase over-expression and StoF mutation in the acetylcholinesterase 1 gene (ace1) in all of the field-collected populations, including the MR strain. We did not detect the LtoF mutation, which is a well-known knockdown resistance ( kdr) mutation in the para-type sodium channel gene ( para), in the MR strain; however, the value of the MR strai nfor bifenthrin was 3,461-fold higher than that of the susceptible strain. Our results indicate that insecticide resistance is m ore effectivel yevaluated using molecular markers than by conducting a bioassay. The molecular markers StoF in ace1 and MtoL in para can easily beapplied in diagnostic methods such as QS or PCR amplification of specific alleles (PASA). These methods may be extended to management of M. persicae resistance in the field.Key words: Myzus persicae, Insecticide resistance, Quantitative sequencing (QS), Esterase over-expression, Mutation초 록: 2009~2011년 동안 국내 주요 배추 재배지 5개 지역(평창, 홍천, 봉화, 무주, 제주)에서 살충제에 대한 복숭아혹진딧물의 저항성 발달 정도를 조사하고, 야외 개체군에 적용 가능한 살충제 저항성 마커를 개발하기 위해 본 연구를 수행하였다 . 조사된 5개 지역 개체군 모두 여러 살충제 종류에 대하여 다양한 저항성을 보였다. 다양한 저항성을 보인 5개 지역 야외 개체군으로부터 여라 살충제에 대하여 복합적으로 저항성을 보이 는복합저항성 계통(MR)을 선발하였고, 이 MR과 모든 지역 채집 개체군에 대해 등전점전기영동과 정량염기서열분석 (quantitative sequencing, QS)을 통하여 에스터레이즈 과발현과 살충제 작용점 내 돌연변이를 확인하였다. MR을 포함한 모든 야외 개체군에서 에스터레이즈의 과발현과 아세틸콜린에스터레이즈 1 유전자(ace1)의 StoF 돌연변이를 확인할 수 있었다. 넉다운 저항성 돌연변이로 잘 알려진 파라 타입 나트륨 채널 유전자(para)의 LtoF 돌연변이는 모든 지역 채집 개체군은 물론 비펜스린에 대해 3,461배 저항성을 보이는 MR에서도 발견되지 않았다. 그 외에 MtoL 돌연변이를 발견하였는데, 생물검정 결과 저항성 수준과 돌연변이 발생 빈도가 일치하였다. 따라서 생물검정 대신, 이러한 분자 마커를 활용 한다면 더 효율적으로 살충제 저항성 평가가 가능할 것이다. 이러한 분자 마커들(ace1의 StoF, para의 MtoL)은 정량염기서열분석, PCR amplification of specific alleles (PASA) 등의 진단 방법에 쉽게 응용이 가능 하고, 이러한 방법은 야외 복숭아혹진딧물 저항성 관리에 적용이 가능 할 것이다.검색어: 복숭아혹진딧물, 살충제 저항성, 정량염기서열분석(QS), 에스터레이즈 과발현, 돌연변이*Corresponding author: forweek@korea.krReceived January 8 2014; Revised March 8 2014Accepted April 3 2014

To control Bemisia tabaci on tomato, we applied five different combinations of chemicaltreatments as below: 1) treatment of combinations of cyantraniliprole on the root area and leaf with theexisting registered chemicals three times; 2) treatment of combinations of cyantraniliprole on the root areaand dinotefuran + emamectin benzoate on the leaf with the existing registered chemicals three times; 3)treatment of combinations of dinotefuran on the root area and cyantraniliprole on the leaf with the existingregistered chemicals three times; 4) treatment of combinations of dinotefuran on the root area and dinotefuran+ emamectin benzoate on the leaf with the existing registered chemicals three times; 5) untreated control plot(Table 1). Twenty days after treatment (17 th Aug.), the number of population of B. tabaci was zero on the 1,2, 3, 4 treatments of combinations, and only 2 individuals were found on the 5 treatment of combination pereach 20 plant. On 17 th Sep., in the last observation, the average number of population of B. tabaci was 10.3,10.3, 10.6 on the 1, 2, 3 treatments of combinations on the 20 plants per each combination, however, theaverage number of 23.3 and 37.6 were examined on the 4 and 5 treatments of combinations, respectively.TYLCV was not occurring on the 1 and 2 treatments of combinations, and presented only 3% and 17% onthe 3 and 4 treatments of combinations, respectively, which indicates that the treatments (1-4) should beeffective on TYLCV control as considering that 33% of TYLCV occurred on the untreated control plot.However, after the third flowering period, there is no difference among the five combinations. The amount ofproducts was 9,148g and 9,698g on the 1 and 2 treatments of combinations, respectively, which was the mostamong the 5 combinations. The number of fallen fruits and the average weight of fruits showed the similartendency.Key words Bemisia tabaci, control effect, cyantraniliprole, tomato, tomato yellow leaf curl virus*Corresponding authorTel: +82-42-821-5769, Fax: +82-42-823-8679E-mail: youngnam@cnu.ac.krORIGINAL ARTICLES / CONTROL

Potato late blight occurrence is caused by various environmental factors, and the progress can be regularly predicted so that several predictive models have been developed. The models predict the timing of the disease occurrence, but they do not include the methods of the disease control. Effective fungicide control, economic threshold, prediction models were investigated in the study to reflect on customized control modules for the model forecasting the occurrence of potato late blight. Key words : Fungicide control, Economic threshold, Phytophthora infestans *Corresponding author: Tel: +82-2-3408-4374E-mail address: jinheelim@sejong.ac.kr I. 서 론 Phytophthora infestans 는 가장 널리 알려진 Phytophthora 속의 종이며, 감자에 역병을 유발한다(Choi et al., 2011). P. infestans는 감자의 잎과 줄기를 통해 침투하여 식물체를 죽이거나 괴경을 썩게 하기 때문에 감자의 재배에 있어 가장 문제시되는 식물병이며, 전세계의 모든 감자 재배지대에서 발생하는 가장 치명적인 병중의 하나이다(Giddings and Berg, 1919; Park et al., 2011). 한국에서도 씨감자 생산지인 강원도 고랭지 지역 및 남부 감자 재배지역에서 역병이 많이 발생하여 수확량 감소에 큰 영향을 미치고 있다(Hahm et al., 1978). 감자역병은 서늘하고 습할 때 발생하는데 그 피해로는 줄기와 잎의 고사로부터 심하면 괴경 부패를 일으키며, 몇 일 사이에 감자 포장 전체가 고사할 수 있다(Choi, 2007). 잎의 병징은 하엽에서 황색 또는 진녹색 반점이 나타나고 병이 진전되면 흑갈색 병반으로 변하는데, 저온 다습한 환경이 계속되면 잎 뒷면에 서릿발 같은 하얀 균사를 형성하고 서서히 이러한 병반을 만들게 된다(Lee et al., 1994; Jang and Kim, 1998). 감자역병은 초발생 이후 2주 이내에 전포장의 90% 이상이 감염되어 엄청난 수량 감소를 가져오는 것으로 알려져 있는데, 관행재배지에서는 감자역병의 발생을 억제하기 위하여 반복적으로 농약을 살포하여 병해에 의한 피해를 최소화하고 있다(Ryu et al., 2005).그러나, 역병은 환경조건에 의해 발생 및 진전이 규칙적으로 이루어져 역병의 발생 예측이 가능하다. 현재 여러 역병 예측 모델들이 개발되어 적용되고 있으며, 이는 관행적인 약제살포에 비하여 약제살포회수의 경감에 의한 경제적 이득뿐만 아니라 농생태계 보호에도 크게 기여하고 있다. 본 연구에서는 감자역병의 감시, 예보 및 확산 방지를 위해 역병 예측 및 방제에 관한 맞춤형 통보 서비스를 제공하고자 하였다. 감자 예측 모델에 적합한 역병 예측 및 방제에 관한 맞춤통보용 방제모듈을 제시하기 위해 감자역병의 효율적 살균제 방제, 경제적 방제수준, 예측모형 등에 관한

Corn was mainly cultivated in slope land during summer season when heavy rain falls so that soil loss occurs severely. Especially, soil disturbance and exposure of topsoil by conventional tillage intensifies soil loss by heavy rain. The aim of this study was to develop surface covering and tillage methods for reducing soil loss in corn cultivation. The experiment was conducted in 17% sloped lysimeter with 8 treatments including strip tillage after surface covering with rye residue, strip tillage after residue covering of several crops and sod culture, black polyethylene film covering after conventional tillage and control. Amount of runoff water and eroded soil, and corn growth were investigated. Amounts of runoff water in all plots except black polyethylene plot ranged from 152 to 375 m³ ha -1 , accounting for 13~32% of 1,158 m³ ha -1 in control. Amount of eroded soil decreased by 94 to 99% (3 to 89 kg ha-1) in plots of strip tillage after covering with crop residues compared to control with 1,739 kg ha -1 . Corn yields in plots of strip tillage after covering with crop residues ranged from 6.0 to 6.9 Mg ha -1 , while that of control was 6.5 Mg ha -1 . The results suggest that strip tillage methods after surface covering with crop residues are very effective on soil conservation of slope land in corn cultivation.

Potato cv. ‘Haryeong’ was bred with high solids, resistance to late blight and good culinary quality. It hasbeen registered as new potato variety in 2005. Tuber necrosis symptoms such as severe superficial necrosis,raised surface lesions and ringed necrotic areas were found in tubers of ‘Haryeong’ during storage of seedpotatoes in 2010. Potato virus Y (PVY) was detected from these symptomatic tubers by the analysis of RTPCRusing a primer set specific to coat protein gene of PVY. The nucleotide sequence of RT-PCR product(PVYHkr) was determined and compared to those of other strains, such as PVYKor, PVYN, PVYNTN, PVYO, andPVYC registered in GeneBank. The result showed that PVYHkr was exactly the same as PVYKor, Korean isolatereported in 2005, except two nucleotides. To verify the PVY was responsible for the tuber necrosis symptomsshown in the tubers of ‘Haryeong’, a bioassay was done using two viruses (PVY and Potato leafroll virus) andfive potato cultivars (‘Haryeong’, ‘Superior’, ‘Atlantic’, ‘Dejima’, and ‘Chubaek’). As expected, the samenecrosis symptom appeared in tubers of ‘Haryeong’ infected with PVY only during the storage period.

PURPOSE Ablation device-associated computed tomography beam hardening artifacts can make tumor margin visualization and its relationship to the ablation applicator tip challenging. Determine optimal scanning conditions for currently-used applicators. MATERIALS AND METHODS Eleven applicators were placed in ex vivo cow livers with implanted mock tumors, surrounded by bolus gel. Various computed tomography scans were performed at 440 mA with 5 mm thickness changing kVp (80, 100, 120, 140), scan time (0.5, 0.7, 1.0, 2.0 seconds), adaptive statistical iterative reconstruction (ASiR) (30, 60, 90), scan type (helical, axial), pitch (0.5, 0.94, 1.37, 1.75), and reconstruction algorithm (soft, standard, lung). Two radiologists blindly scored the images for image quality and artifact quantitatively. RESULTS Cool-tip single (CTS) RF electrode (Covidien) performed significantly better than all other devices in both perceived image quality and artifact while Boston Scientific 4.0 RF electrode (Boston Scientific) underperformed (all P < 0.001), when not controlling for any other factors. An effect for artifact (P < 0.001) was found for kVp and device: for most conditions, 80 kVp was rated significantly lower than all other levels, whereas 120 and 140 performed significantly better than 100 and 80. No significant effect with ASiR level and device was found for the artifact. There was an effect observed for artifact (P < 0.001) between scan time and probe: for most devices, 0.5 seconds was rated significantly lower than all other scan times, but CTS was resilient-showing no difference from other scan times. Algorithm did not show any significant effects. Taking into account ASiR, kVp, and time, CTS outperformed all other devices. CONCLUSIONS Higher kVp and scan times reduce device artifacts. It appears that CTS performs the best, even when considering ASiR, kVp, pitch, scan type, and scan time.

This research was carried out to investigate the interaction effect of slope gradient and rainfall intensity on soil loss with rainfall simulator. The soils used in this experiment were saprolite, Chahang series which distributed extensively in Daegwanryong. Slope gradient applied was 0.5, 7, 15 and 30%. Rainfall intensity applied was 20, 60 and . The result obtained can be summarised as follow; Overall, Chahang series suffered more losses than saprolite. Chahang series shows the immediately large increase of soil loss with the increasing soil gradient and rainfall intensity. However, saprolite shows a little increasing loss up to 7% gradient and abruptly increasing loss logarithmically over 7% gradient in soil slope. In combination of slope gradient 15, 30% and rainfall intensity 60, processing, both soil erosion happened significantly. And there was no significant difference between the two soils. Because Chahang series have the danger of soil loss with low slope gradient and rainfall intensity, we should give greater attention to soil management in Chahang series.

The gray mold disease occurred on tuberous roots of yacon in storage facilities in Gangneung, Korea, in March 2010. Symptoms typically appeared as in the form of dark brown discoloration on the surface of tuberous roots and water-soaked brown lesions in cross sections of the affected portions. A total of five isolates of Botrytis sp. were obtained from the symptomatic portions. All isolates on potato-dextrose agar (PDA) produced abundant conidia which were pale brown, one-celled, mostly ellipsoid or ovoid in shape and in size. Large numbers of round to irregular, smooth, black, hard sclerotia were produced on PDA over time. The optimal temperature for mycelial growth and sclerotia formation of the fungal isolates was . On the basis of morphological and cultural characteristics, all the fungal isolates were identified as Botrytis cinerea. Pathogenicity test on host plants showed that the fungus could infect not only tuberous roots but also leaves and petioles of yacon. This is the first report on gray mold of yacon (Smallanthus sonchifolius) caused by Botrytis cinerea in Korea.

Potato late blight caused by Phytophthora infestans was the most constrain disease at potato cultivation areas. The mating type distribution and fungicides response of P. infestans were investigated to elucidate the changes of pathogen from Gangwon province. On the fungal isolates in 2006, 58.7% were A1 mating type and 41.3% were A2 mating type. In 2007, A1 mating type isolates increased to 93.3% and A2 mating type isolates were collected from Jinbu areas as much as 6.7%. About 234 isolates analysed for metalaxyl response, the results was resistance 73.7%, intermediate 18.8% and sensitive 7.5% in 2006. And it was resistance 59.4%, intermediate 4.0% and sensitive 36.6% in 2007. It meant that mating type distribution and fungicide response were very different over the collection sites. Minimal inhibition concentration (MIC) of dimethomorph examined with 126 isolates in 2006 and 106 isolates in 2007. MIC over was 56.3% in 2006 and it was 3.8% in 2007. The average value of P. infestans was in 2006, but it decreased to in 2007. Fungicides response and pathogenesis of P. infestans should be monitored continuously to enhance the chemical efficacy at potato fields.

The seasonal fluctuation of the large 28-spotted lady beetle, Henosepilachna vigintioctomaculata (Motschulsky), was observed in potato fields of Gangneung region, Gangwondo Province. The effects of their leaf consumption over a 24 hour period and developmental periods by different temperatures were investigated, and then the developmental threshold (DT) and effective cumulative temperature (ET) of each stage were calculated. Various developmental stages of H. vigintioctomaculata were captured in the fields from May to September, with three peaks in late May, late June, and late August. Leaf consumption by larval stages increased with the development of instar. The 4th instar larvae consumed potato leaves much more than other stages. Egg hatchability and emergence rate of H. vigintioctomaculata were lower at and , but higher at around . The developmental periods of each stage became shorter as temperature increased; 90 days at , 40 days at and 25 days at . Base on developmental velocity to temperature, calculated DT and ET were and 83.

To select rotation crops for control of clubroot of Chinese cabbage, potato, corn, soybean, onion and groundsel were planted in the field infected with clubroot pathogen (Plasmodiophora brassicae) in highland area in 2000. In comparison of economical efficiency among rotation crops, potato and onion gained about 16.9 and 14.9 times higher, respectively, than successive cultivation of Chinese cabbage. Resting spore densities of Plasmodiophora brassicae after harvesting rotation crops were in the range of soil in all cultivated soils with rotation crops while that of successive Chinese cabbage cultivation soil was very high as much as soil. And disease severity of Chinese cabbage clubroot was 4.9, 20.2, 24.4, 25.1 and 27.8% in onion, soybean, potato, corn, and groundsel cultivation plot, respectively, while that of successive Chinese cabbage cultivation plot was very high as 77.8%. Effect of rotation period of onion, potato, soybean on disease control was investigated from 2002 to 2005. Resting spore densities of Plasmodiophora brassicae after cultivating rotation crops were decreased until year and maintained low density at year in all plots, while that of successive Chinese cabbage cultivation plot was increased 2.6 to 23.6 times for three years. When Chinese cabbage was rotation-cultivated with potato, soybean and onion for three years, disease severities of Chinese cabbage clubroot decreased 92 to 4.4%, 72 to 10.4% and 72 to 12.2%, respectively, while that of successive Chinese cabbage cultivation plot maintained 100%. As the rotation period increased, the yields of Chinese cabbage increased, while that of successive Chinese cabbage cultivation plot decreased. At year, Chinese cabbage with high quality could be much more produced 2,205, 2,493 and 2,476 g in potato, soybean and onion cultivation plot, respectively, than 95 g in successive Chinese cabbage cultivation plot.

The effect of calcium cyanamide() on suppression of clubroot of Chinese cabbage was evaluated in the fields infested with Plasmodiophora brassicae at National Institute of Highland Agriculture, Pyeongchang, Korea, from 2002 to 2003. Calcium cyanamide was found to be more effective in reducing disease severity than flusulfamide dust powder. The optimal dosage of calcium cyanamide for control of clubroot of Chinese cabbage was 61 kg/10a. When calcium cyanamide was incorporated into soil at 5, 10, 15 and 20 days before planting(DBP), maximum disease suppression was obtained in the plot with calcium cyanamide, applied 5DBP. The fertilizer property of calcium cyanamide as a nitrogen fertilizer was also investigated by comparing with urea on cv. CR Gangta, a resistant variety of Chinese cabbage. The nitrogen uptake in calcium cyanamide treatment(17.6 kg/10a), was not significantly different from that of urea(17.8 kg/10a). These results indicated that calcium cyanamide could be used as a soil disinfectant as well as a nitrogen fertilizer.

Changes of control efficacy of chemical to potato late blight caused by Phytophthora infestans in potato fields from 2001 to 2004 were examined. Control efficacy of metalaxyl was suddenly decreased from 100% in 2002 to 50% in 2004 and that of dimethomorph also was similar to those of metalaxyl. However, the control efficacy of ethaboxam no great change. Both A1 and A2 mating type isolates were isolated from 2001 to 2004 in several areas in Korea. The majority of the P. infestans isolates were A1 mating type. Total 939 isolates of P. infestans obtained from several areas in Korea from 2001 to 2004 were examined for changes of sensitivity to metalaxyl. Frequencies of metalaxyl resistance isolates were gradually increased from 17% in 2001 to 84.2% in 2004, but isolation frequencies of metalaxyl sensitive and intermediate resistant isolate were decreased. Cause of decreasing control efficacy of metalaxyl was thought by increase of resistance isolates in A1 mating type population according to increasing metalaxyl use. Most isolates were grown at 0.5 /ml of dimethomorph and isolates grown at 1 /ml of dimethomorph were approximately 10.2-22.9%. However, no isolate was able to grow at 5.0 /ml. Based on these results, minimum inhibitory concentrations (MIC) of dimethomorph to P. infestans were determined to be 0.5-1.0 /ml. Our results indicated that the reason decreasing control efficacy of dimethomorph was not caused by occurrence of resistant isolates. About 5% and 12.1% isolates among the total isolates collected in 2003 and 2004 were grown on V-8 juice rye agar containing 1.0 /ml ethaboxam. The 2.1 and 25.4% isolates had MICs of 0.2-0.4 /ml, and MIC values of 87.9% and 74.3% isolates were less than 0.2 /ml concentrations of ethaboxam. Therefore, resistance development by P. infestans to ethaboxam is not likely to occur in the natural condition.

A leaf blight disease was found on Ailanthus altissiman growing in the Manchon Mountain Park in Daegu city. When isolated, the causal fungus readily formed sex organs, being homothallic. Oogonia were spherical, 19.5-42.9 in diameter with an average of 29.44.2 . Antheridia were amphigynous, round to ovoid, and measured 11.3-15.0 long and 12.5-14.5 wide. Oospores in the oogonia were spherical, 26.1-29.0 in diameter. Sporangia that formed in water were spherical to sub-spherical with a conspicuous papilla and measured 19.5-56.6 15.6-44.9 with an average of 44.08.732.76.3 . The mean length/breadth (I/b) ratio was 1.35. Papillae were 3.9-11.7 l high and 3.9-9.8 wide. Sporangia formed slowly on V8 juice agar medium when cultured under fluorescent light at 12-hour alternation. The sporangia that formed on the agar medium were more spherical and measured 26.5-39.023.4-35.1 with an average of 33.63.428.23.2 and I/b ratio of 1.19. Disease symptom was repro-duced by artificial inoculation of the healthy plants with the isolate. The causal organism was identified as Phyto-phthora boehmeriae on the basis of its morphological characteristics.

Verticillium wilt was first observed in 2001 on potatoes (Solanum tuberosum) cv. Superior at Daegwallyong area, one of the major seed potato producing areas in Korea. The wilted potato plants showed typical symptoms including gradual yellowing and interveinal necrosis. There was discoloration in the vascular tissues of the infected stems which turned light brown. Fungal isolates from discolored vascular tissues were whitish to creamy with folding on potato dextrose agar medium, where they used to produce resting dark mycelia but no micro-sclerotia. Conidiophores were septate with side branches, swelled at the base, and arranged in a whorl. Conidia were 2.5-11.22.0-4.5 um in size and were borne in small clusters at the tips of phialides. Optimal temperature range for mycelial growth was . Based on these cultural and morphological characteristics, the fungus was identified as Verticillium albo-atrum Reink & Berth. Pathogenicity tests by root dipping method revealed that the fungus caused the same symptoms as observed in naturally infected potato plants. This is the first report of Verticillium wilt on potato caused by Verticillium albo-atrum in Korea.

Pink rot of potato (Solanum tuberosum L.) occurred at Pyeongchang in Gangwon and at Bosung in Junnam province since 1999. The disease incidence in the surveyed areas was about 5% of harvested potatoes in 2002. Affected tubers showed a dull brown appearance and the lenticels and eyes on tubers turned dark brown. The cut surface of the diseased tuber colored faint pink and the entire surface of the diseased tuber becomes deep salmon pink within 30 min. The pathogen isolated from the diseased tubers was identified as Phytophthora erythroseptica based on morphological and cultural characteristics. Mycelial mat was fairly fluffy, rosette or stellate patterns and rounded or angular hyphal swellings were farmed in water, Temperature for mycelial growth was ranged from 5 to 3 and optimal temperature was . Non-papillate sporangia were persistent on stalk and ellipsoid, ovoid, obpyriform or distorted in shape, often with a constriction distal in the middle. Size of sporangia was 41.3~69.626.8~47.4 (av, 55.537.1) . Sexuality of Phytophthora erythroseptica was homothallic. Oogonia were 30~46 in diameter and oospores were 28~35 in diameter, Elongated or cyclindrical antheridia were all amphigynous. This is the first report on potato pink rot caused by Phytophthora erythroseptica in Korea.

From 1996 to 1999, potato-growing areas in Korea were surveyed for identification and distribution of potato scab pathogens. Potato scab was widely distributed in the mass cultivation areas, especially in Jriu island, southern areas of Chonnam and Gyounggi provinces, and the alpine area of Gangwon province. Jeju island was the most affected area by this disease. A total of 55 Streptomyces strains were isolated from potato scab lesions, among which 40 strains were pathogenic on progeny tubers. Among the pathogenic strain, 21 strains were identified as previously described S. scabies, 7 Strains as S. turgidiscabies, and 5 Strains as S. acidiscabies, while 7 strains were observed as having distinct phenotypic properties. These strains were classified into six distinct clusters based on phenotypic characteristics and selected representative strains for each cluster. S. scabies (S33) had grey spores in a spiral chain. Mean-while, S. turgidiscabies (S27) had grey spores, S. acidiscabies (S71) had white spores, S. luridiscabiei (S63) had yellow-white spores, S. puniciscabiei (S77) had purple-red spores, and S. niveiscabiei (S78) had thin and compact white spores, all in a rectiflexuous chain. Pathogenicity was determined by the production of thaxtomin A and homologs of necl and ORFtnp genes. In TLC, representative strains S27, S71, S63, S77, and S78 produced a yellow band that co-migrated with the authentic thaxtomin A. However, thaxtomin A was not detected in chloroform extracts from oatmeal broth culture and Slice tuber tissue of S. luridiscabiei (S63) and S. puniciscabiei (S77) by HPLC analysis. In addition, no homologs of necl and ORFtnp genes in S. acidiscabies (S71), S. luridiscabiei (S63), S. puniciscabiei (S77), and S. niveiscabiei (S78) were detected by PCR and Southern hybridization analysis.

The potato scab is caused by several species of Streptomyces. Among these species, only pathogenic strains were found to produce thaxtomin A characterized by necrotic bioassay and HPLC. In this study, identification of the pathogenic strains of Streptomyces was performed through the polymerase chain reaction (PCR) by using specific pathogenicity primer sets derived from the nec1 gene sequences of Streptomyces scabies. The expected PCR products were obtained approximately 580 bp and confirmed by sequencing. This PCR technique can be used effectively to identify the pathogenic Streptomyces species, that cause scab on potato tubers.

Background: Closed reduction and percutaneous pinning of a pediatric supracondylar fracture of the humerus requires operating directly next to the C-arm to hold reduction and perform fixation under direct imaging. This study was designed to compare radiation exposure from two C-arm configurations: with the image intensifier serving as the operating surface, and with a radiolucent hand table serving as the operating surface and the image intensifier positioned above the table. Methods: We used a cadaveric specimen in this study to determine radiation exposure to the operative elbow and to the surgeon at the waist and neck levels during simulated closed reduction and percutaneous pinning of a pediatric supracondylar fracture of the humerus. Radiation exposure measurements were made (1) with the C-arm image intensifier serving as the operating surface, with the emitter positioned above the operative elbow; and (2) with the image intensifier positioned above a hand table, with the emitter below the table. Results: When the image intensifier was used as the operating surface, we noted 16% less scatter radiation at the waist level of the surgeon but 53% more neck-level scatter radiation compared with when the hand table was used as the operating surface and the image intensifier was positioned above the table. In terms of direct radiation exposure to the operative elbow, use of the image intensifier as the operating surface resulted in 21% more radiation exposure than from use of the other configuration. The direct radiation exposure was also more than two orders of magnitude greater than the neck and waist-level scatter radiation exposure. Conclusions: Traditionally, there has been concern over increased radiation exposure when the C-arm image intensifier is used as an operating surface, with the emitter above, compared with when the image intensifier is positioned above the operating surface, with the emitter below. We determined that, although there was a statistically significant difference in radiation exposure between the two configurations, neither was safer than the other at all tested levels. Clinical Relevance: In contrast to traditional teaching regarding radiation exposure, neither C-arm configuration—with the image intensifier serving as the operating surface or with the image intensifier positioned above a radiolucent hand table—was shown to be clearly safer for pediatric supracondylar humeral fracture fixation.

Three plant-pathogenic isolates of Streptomyces spp., isolated from potatoes with common scab disease lesions in Korea, are described as novel species. Morphological and physiological properties of these isolates were distinct from those of previously described Streptomyces species. Strain S63(T) has yellow-white, smooth, cylindrical spores that are borne in monoverticillus flexuous spore-chains. Strain S77(T) has purple-red, spiny spores that are borne in simple rectus flexuous spore-chains. Strain S78(T) has white, smooth, cylindrical spores that are borne in simple rectus flexuous spore-chains. These three isolates differed from known pathogenic strains by analysis of 16S rRNA gene sequences in a previous study. Furthermore, genetic uniqueness of our isolates was confirmed by sequencing of the 16S-23S internal transcribed spacer (ITS) region, which indicated that isolates S63(T) and S78(T) belong to the genus Streptomyces and have low homology to other Streptomyces species (less than 71.2 and 75.7 %, respectively). The 16S-23S ITS region of strain S77(T) was not amplified by these primer sets. DNA-DNA hybridization results for all three isolates show distant relationships to previously described Streptomyces species; therefore, on the basis of polyphasic evidence, the names Streptomyces luridiscabiei sp. nov. for strain S63(T) (=LMG 21390(T)=KACC 20252(T)), Streptomyces puniciscabiei sp. nov. for strain S77(T) (=LMG 21391(T)=KACC 20253(T)) and Streptomyces niveiscabiei sp. nov. for strain S78(T) (=LMG 21392(T)=KACC 20254(T)) are proposed.