Salmonella is one of the most important bacterial pathogens responsible for many zoonotic food-related infectious diseases. Quantitative detection of the foodborne Salmonella contamination in various food sources is therefore critical for preventing the related disease outbreaks. In this study, we developed and evaluated a reliable real-time polymerase chain reaction (RT-PCR) assay to detect the Salmonella contamination quantitatively. The experimental results showed that our invA gene-specific quantitative RT-PCR (qRT-PCR) assay provides a strong correlation between the Cq values and the direct plate counts of Salmonella species in the artificially formulated samples. Further study may be necessary to identify more accurate correlation and equation that can apply to Salmonella spp.

경기도농업기술원에서는 2016년도에 고온기 생육 및 개화 특성이 우수한 절화용 스프레이 국화 ‘Perky Star’ 품종을 개발 하였다. 2012년도에 화색이 진한 노란색이면서 좁고 긴 설상화를 가진 ‘Sei-vista’ 품종을 모본(♀)으로, 화형이 좋은 ‘Amisa’ 품종을 부본(♂)으로 인공교배를 하였고 2014년부터 2016년까지 억제재배, 촉성재배, 가을재배 작형에서 생육 및 개화특 성을 검정하였다. 2016년 기호도 조사를 통해 최종적으로 GCS12-81-150계통을 선발하여 ‘Perky Star’로 명명하였고 2017 년에 국립종자원에 품종보호출원(제2017-64호)한 후 2018년에 품종보호권이 등록(제7465호)되었다. ‘Perky Star’ 품종은 노란 색 홑꽃형으로 고온에서 화색발현과 생육이 좋았으며 꽃잎이 두꺼워 여름철 수출품종으로 적합하다고 판단되었다. 가을재 배작형, 억제작형, 촉성작형에서 단일처리 후 개화소요일 수는 각각 49, 49, 53일, 절화장은 88.3, 84.2, 103.3cm, 꽃의 직경은 5.1, 4.8, 4.8cm, 줄기당 착화수는 25.0, 21.5, 38.8개로 고온에서 절화장과 착화수가 증가하는 경향을 보였다. 흰녹병 에 완전한 저항성을 갖지는 못한 품종이며, 자연개화 작형에서 절화수명은 21.3일로 대조품종 20.2일에 비해 조금 길었고, 5점 척도로 기호도를 조사한 결과 4.2점으로 대조품종 4.1과 비슷한 선호도를 보였다.

Frankliniella occidentalis is a major pest in agriculture. Following overuse of insecticides, high resistance has developed due to its high reproduction rate and short generation time. To control the resistant strains of the thrips, the ingestion RNAi- based control was established. A total of 67 genes were selected, and their double-stranded RNAs (dsRNA) were delivered to thrips via the leaf disc-feeding method. Among the genes screened, the dsRNA of Toll-like receptor 6 (TLR6) and coatomer protein subunit epsilon (COPE) resulted in the highest mortality (3.8- and 2.8-fold faster LT50 compared to control, respectively) when ingested by thrips. The dsRNA-fed thrips showed 53% and 83% reduced transcription levels of TLR6 and COPE, respectively. This result demonstrates that the observed mortality of thrips following dsRNA ingestion was due to RNAi, and this lethal genes can be employed as a practical tool to control thrips in the field.

Roller Compacted Concrete Pavement (RCCP) is placed by roller compaction of a mixture of less cement and unit water content and more aggregates and provides excellent early strength development with the help of interlocking of aggregates and hydration. The unit cement content of RCC pavements accounts for 85% of conventional pavements, with low drying shrinkage. As low drying shrinkage leads to smaller crack widths than ordinary concrete, RCC pavements can help elevate reflecting crack resistance if applied to a base layer of a composite pavement system. In a composite pavement with an asphalt surface laid over a concrete base, pavement temperature change is important in predicting pavement performance. As movement of the lower concrete layer is determined by temperature depending on pavement depth, temperature data of the pavement structure serves as an important parameter to prevent and control reflecting crack. Among the causes of reflecting crack, horizontal behavior of the lower concrete layer and curling-caused vertical behavior of joints/cracks are considered closely related to temperature change characteristics of the lower concrete course (Baek, 2010). Previous studies at home and abroad about reflecting crack have focused on pavement behavior depending on daily and yearly in-service temperature changes of a composite pavement (Manuel, 2005). Until now, however, studies have not been conducted on initial temperature characteristics of concrete in composite pavements where asphalt surface is placed over an RCC base. Annual temperature changes of in-service concrete pavements go up to 60 ℃, and those of asphalt overlays become around the twice at 110 ℃. This study evaluated initial crack behavior of composite pavement by investigating pavement temperature by depth of an RCC base and analyzing joint movement depending on change to temperatures of continuously jointed pavements. Findings from the study suggest that in composite pavements and asphalt overlays, time of laying asphalt has an important impact on crack behavior and reflecting crack.

The acaricidal activity of a methanolic extract and fractions from the rhizome of Cnidium officinale against Dermanyssus gallinae adults was investigated. The C. officinale methanolic extract exhibited 100% acaricidal activity after 48 h of treatment at a dose of 4,000 ppm. Gas chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy revealed (Z)-ligustilide as a constituent of C. officinale. Acaricidal activity was examined in three experimental tests (spray, fumigation and contact), with the spraying method being the most effective. The methanolic extract of C. officinale showed both contact and fumigant activities, though only fumigant activity was observed with (Z)-ligustilide. These results suggest that C. officinale derived material can be used for the development of a control agent for D. gallinae.

We demonstrated an effective way of preparing melt spinnable mesophase pitches via catalytic hydrogenation of petroleum residue (fluidized catalytic cracking-decant oil) and their subsequent thermal soaking. The mesophase pitches thus obtained were analyzed in terms of their viscosity, elemental composition, solubility, molecular weight, softening point and optical texture. We found that zeolite-induced catalytic hydrogenation under high hydrogen pressure contributed to a large variation in the properties of the pitches. As the hydrogen pressure increased, the C/H ratio decreased, and the solubility in n-hexane increased. The mesophase pitch with entirely anisotropic domains of flow texture exhibited good meltspinnability. The mesophase carbon fibers obtained from the catalytically hydrogenated petroleum residue showed moderate mechanical properties.

The seroprevalence of major infectious abortion agents was investigated in native Korean goats from Jeonnam province using ELISA. A total of 98 blood samples were collected from goats. Overall, 48 (49.0%), 11 (11.2%), and 1 (1.0%) serum samples tested positive for C. burnetii, T. gondii, and C. abortus, respectively, while none of the samples were positive for B. abortus or N. caninum. Moreover, a PCR assay conducted to detect C. burnetii antigens in goats with a history of abortion revealed 18 (38.3%) of 47 goats were C. burnetii positive by both the ELISA and PCR assay.

Ooencyrtus nezarae lshii (Hymenoptera: Encyrtidae) is a major egg parasitoid of Riptortus pedestris (F.) (Hemiptera: Alydidae). One of the components of the aggregation pheromone of R. pedestris, (E)-2-hexenyl (Z)-3-hexenoate (E2HZ3H), is known to attract O. nezarae female. Response of O. nezarae females to E2HZ3H and its isomers was studied using electro-antennogram (EAG) and field tests. O. nezarae females showed higher antennal response to E2HZ3H and Z2HE3H isomers than E2HE3H and Z2HZ3H. In field tests, O. nezarae females were attracted to E2HZ3H traps, but not to Z2E3 traps. Interestingly, the blend of E2HZ3H and Z2HE3H showed significant antagonistic activities to the attraction of O. nezarae females in the field. We conclude from this study that Z2HE3H is a potent antagonist to the behavioral response of O. nezarae.

Roller-compacted concrete or RCC is a dry concrete that requires compaction in order to reach its final form. Its consistency is usually overlooked due to its inconsistency and lack of subjective nature. To work with this concrete, however, appropriate consistency is required for supporting the compacting machine and minimizing compaction energy. Due to transportation and compaction time, maintaining proper consistency within a period of time is also necessary. Vebe time, a represent parameter of dry concrete consistency, ranged from 30 to 75 seconds is considered appropriate for RCC in pavement application. The purpose of this study is to improve workability of this concrete which consisted of improving its consistency and maintaining it within the working time. It was confirmed that the workable time of a normal RCC is less than one hour. Moreover, it was found that Vebe time drops when water content increases and goes up when sand by aggregate ratio increases. Various admixtures were also employed in this study in order to improve the workability of this concrete. Poly Naphtalene Sulfonate superplasticizer, particularly, was found to be the most effective in term of lowering down Vebe time and maintaining it. With just 0.3% of this admixture, the working time of RCC can be extended up to four hours without affecting its compressive strength.

More Roller-compacted concrete (RCC) is a dry concrete consisted of same materials as conventional concrete with different proportioning which requires compaction effort in order to reach its final form. Thus, both hydration and aggregate interlock play important roles in its strength augmentation. Flexural strength, an important factor in pavement design and fatigue cracking resistance, can be difficult to be obtained at in-situ and may be subjected to high variability. Even though its compressive strength is relatively high compared to conventional concrete with similar binder content, the relationship between compressive strength and flexural or tensile strength were not well defined. The goal of this research is to compare the relationship between compressive strength and flexural strength as well as the relationship between compressive strength and splitting tensile strength of RCC with those of conventional concrete using various equations suggested in other researches and also to determine new regression equations for estimating RCC’s flexural and splitting tensile strength. The positive result of RCC’s flexural strength was found; it was higher than majority of predicted values from conventional concrete for the same compressive strength. In contrast, RCC’s splitting tensile strength was relatively low compared to that of conventional concrete for the same compressive strength. Power equations were learned to be suitable for relationship between compressive and flexural strengths as well as relationship between compressive and splitting tensile strengths.

This study was conducted to investigate the effectof supplemental lighting intensity (SLI) on the shoot growthand flower quality of Rosa hybrida ‘Pink Bell’ in winter sea-son. High pressure sodium lamps (HPS) which were set upat 1.4m height above the planting beds were adjusted forthe SLI treatments: no supplemental lighting (control), pho-tosynthetically active radiation (PAR) 30, 50, 70, and 90µmol•m−2•s−1 in 20h daylength (17:00 to 22:00 and 02:00to 09:00). Shoot growth including shoot elongation, shootweight, and flowering speed was promoted quantitatively asSLI increased. But the flower quality such as petal num-bers, petal pigmentation, and biomass distribution to thepetals was declined at PAR 90, even though the proper SLIfor rose production was generally known in the range ofPAR 90 to 120. In this experiment PAR 90 treatment madethe surface of petals heated near 30oC which was about10oC higher than the control group without supplementallighting. The surface temperature of the petals was continu-ously rising because the distance to lamps from floral budsbecame increasingly short as the shoots grew in localgreenhouse facilities. The heat stress by HPS lampscaused petal discoloration and over-consumption of assimi-lation products due to excessive respiration and water lossin petals. Thus, it is necessary to prevent heat injury byswitching light intensity depending on shoot growth consid-ering local greenhouse structure.

More than sixty percent of highways in Korea were constructed with concrete pavement to carry the heavy traffic loads due to the economic development of this country. The service life of some pavements are close to the end, therefore, they requires the maintenances, rehabilitations and reconstructions to improve their structural performances.According to the similarity of material properties to the concrete pavement, bonded concrete overlay isa good rehabilitation technique used steadily in Korea. However, it is recently reported that the bonded concrete overlays in some highways expose the early distresses and it is assumed that the poor bonding is a cause of this problem. Additionally, the poor bonding of bonded concrete overlay is caused by the bond strength that is less than the bond strength criterion. The pre-investigation of various concrete overlays is conducted in laboratory to determine the possible influence factors reducing the bond strength and it indicates that there are two possible factors affecting the bond strength: the concrete overlay types and the substrate conditions. The study investigates the vulnerable factor between the two factors based on theevaluation of the in-situ bond strength data of bonded concrete overlay gathered from some highways in Korea. The bond strength data is collected from two different application areas: the new constructionand the rehabilitation projects. The new construction and the rehabilitation projects used Latex-modified Concrete (LMC) and Ultra-rapid Hardening Latex-modified concrete (URH-LMC), respectively as the concrete overlay. The evaluation of in-situ bond strength is to determine the percentage of unacceptable bond strength in each projectto study the effect of different types of concrete overlay. Moreover, the percentage of bonding failure modes having the bond strengths less than the criterion is also measured to study the effect of substrate condition.As a result, substrate condition is the vulnerable factor affecting the poor bonding and causing the early distresses in bonded concrete overlay.