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Simple Summary: Invasive snails and flies are among the major groups of pests intercepted from imported orchids in Korea, which are controlled by methyl bromide (MB) fumigation. As a first step to develop an alternative treatment, we compared the efficacy and phytotoxicity of ethyl formate (EF) and MB on four species of imported orchids using juvenile stages of Achatina fulica and third and fourth instars of Lycoriella mali. Efficacy trials showed that EF was at least as effective as MB with LCt99 (lethal concentration × time product required for 99% mortality) values of EF at 68.1 and 73.1 g h/m3 at 15 °C and LCt99 of MB at 95.9 and 78.4 g h/m3 at 15 °C for A. fulica and L. mali, respectively. In scale-up trials, EF treatment at 35 g/m3 for 4 h at 15 °C resulted in complete control of A. fulica and L. mali. MB treatment based on the current treatment guideline for imported orchids (48 g/m3, 2 h at >15 °C) resulted in complete control of L. mali but not A. fulica, which could be completely controlled with 3 h treatment. Leaf chlorophyll contents and hue values of treated orchids were not affected by EF treatment but were significantly changed by MB. All four species of orchid died within 30 d of MB treatment, while only one species could not recover the damage from EF treatment. Our results suggest that EF is as effective as MB for snails and flies and less phytotoxic than MB to imported orchids and may be applicable as an alternative to MB in phytosanitary treatments of invasive snails and flies of imported orchids. Invasive snails and flies are major pests of imported orchids, controlled by methyl bromide (MB) fumigation in Korea. We compared the efficacy and phytotoxicity of ethyl formate (EF) and MB on four species of imported orchids using juvenile stages of Achatina fulica and third and fourth instars of Lycoriella mali. EF was as effective as MB. The LCt99 values of EF were 68.1 and 73.1 g h/m3 at 15 °C; and those of MB were 95.9 and 78.4 g h/m3 at 15 °C for A. fulica and L. mali, respectively. In the scale-up trials, EF treatment at 35 g/m3 for 4 h at 15 °C resulted in complete control of both pests. MB treatment based on the current treatment guidelines for imported orchids (48 g/m3, 2 h, at >15 °C) resulted in complete control of L. mali but not of A. fulica. Chlorophyll content and hue values of treated orchids were not affected by EF treatment but significantly changed by MB (p-value < 0.05). All four treated species of orchids died within 30 d of MB treatment, while only one species died from EF treatment. Our results suggest that EF is a potential alternative to MB in phytosanitary treatment of imported orchids. [ABSTRACT FROM AUTHOR]

Exotic ants and termites, including Solenopsis invicta, are frequent hitchhikers intercepted from miscellaneous nonfood commodities. In particular, S. invicta has been intercepted in Korea in imported nursery plants, stone, and lumber products, which increases the potential for establishment of this destructive invasive pest in Korea. In this study, we conducted commercial-scale fumigation trials to evaluate ethyl formate (EF) as a potential alternative of methyl bromide using two species of imported rubber plants and pieces of marble as representative good and workers of Reticulitermes speratus as an EF-resistant surrogate for S. invicta. An EF treatment at 35 g/m3 for 4 h at >15 °C, the dose required for LCt99% (lethal concentration × time product required for 99% mortality of R. speratus), resulted in the complete control of R. speratus workers tested with rubber plants (Ficus benghalensis and F. retusa) and marble, 9% (w/v) and 60% (v/v) loading ratios, respectively. EF treatment did not adversely affect the leaf chlorophyll content, leaf color, and overall health of rubber plants or the visual appearance of the marble. Our results suggest that EF fumigation is a potential alternative to methyl bromide for the disinfestation of hitchhiking invasive termites and ants, including S. invicta, on imported rubber plants and stone products. [ABSTRACT FROM AUTHOR]

Ethyl formate (EF) was evaluated as a potential alternative to methyl bromide (MB) for phytosanitary treatment of imported citrus fruit in the Republic of Korea. Planococcus citri (Risso) (Hemiptera: Pseudococcidae), a mealybug with known tolerance against EF and MB, was used as a representative pest to test efficacy of the two fumigants against eggs. In nine commercial-scale refrigerated container (67.5 m3) trials using imported orange, lemon and grapefruit, EF applied at the currently approved dose for citrus (70 g·m-3 at 5°C for 4 h, developed for Aspidiotus excisus Green (Hemiptera: Diaspididae), a species less EF tolerant than P. citri) resulted in 76.9–98.3% mortality of P. citri eggs. The EF treatment did not affect the sugar content or the color of peel and pulp of the treated fruit. When oranges were treated according to the current MB (64 g·m-3 at >5°C for 2 h) or EF treatment guidelines, the concentration of fumigant around the fruit fluctuated between 9.4 and 185.1 ppm for EF and 9.5–203.0 ppm for MB during the 72-h post-fumigation processes (venting [0–2 h], transportation to storage [2–24 h], and storage periods [24–72 h]) with both EF and MB maintained between 10 and 100 ppm during the storage period. Considering the efficacy of EF, its apparent lack of phytotoxicity, and its more manageable threshold limit value for humans (100 ppm EF compared to 1 ppm MB for an 8-h time weighted average exposure), our results suggest that EF may be a promising alternative to MB for the phytosanitary treatment of imported citrus in Korea. [ABSTRACT FROM AUTHOR]

Methyl bromide (MB) use for quarantine and phytosanitary purposes is being phased out. Several effective MB alternatives have been identified depending on the target system. Industry commitment for the shift to new technologies will depend not only on the efficacy of alternatives but also on their compatibility and integrability into existing operations. We compared the efficacy of MB and ethyl formate (EF) for disinfestation of Planococcus citri (Risso) (Hemiptera: Pseudococcidae) as a representative surface pest on banana and evaluated whether EF fumigation is compatible with the current packaging materials and loading ratio used by the South Korean banana import industry. Fumigation trials with P. citri adults and eggs showed that EF was at least as effective as MB at the EF and MB concentrations recommended under the current phytosanitary disinfestation guidelines. From a logistical standpoint, EF gas could not effectively penetrate plastic bagging typically used in banana cartons during commercial shipping. Also, EF sorption to bananas and packing materials (used as cushioning inside bagging) further lowered realized EF concentrations around bananas. These reductions in EF concentration translated into reduced mortality of P. citri eggs, indicating that despite similar efficacy of MB and EF for controlling P. citri , further consideration and optimization of other industry logistics such as packaging and loading ratio is necessary to enhance the adoption of this MB alternative. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sacbrood virus (SBV) is a fatal viruses that infects the Asian honey bee, Apis cerana in Korea. Recently, RNA interference (RNAi) has been suggested as a promising strategy for the suppression of honey bee viruses. For the efficient control of SBV infection using RNAi, simple and cost‐effective methods to produce double‐stranded RNA (dsRNA) are needed. RESULTS: To develop a dsRNA production platform using Bacillus thuringiensis (Bt), pBTdsSBV‐VP1 vector was constructed in which the SBV vp1 gene was located between two oppositely oriented cyt promoters. Both strands of the vp1 gene were bidirectionally transcribed under the control of the sporulation‐dependent cyt promoter in Bt cells transformed with pBTdsSBV‐VP1, and the resulting dsRNA was easily extracted from the Bt transformant, Bt 4Q7/pBTdsSBV‐VP1, by inducing its autolysis. The replication of SBV was dramatically suppressed in A. cerana workers who ingested the dsRNA produced from the Bt 4Q7/pBTdsSBV‐VP1. CONCLUSION: In this study, we successfully silenced SBV in its host, A. cerana, by the application of exogenous dsRNA produced from an entomopathogenic bacteria, Bt. These results suggested that Bt could be a useful dsRNA production platform to control viral pathogens in their host insects. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

It has not been well established whether dietary folate intake reduces the risk of diabetes development. We aimed to clarify the prospective association between dietary folate intake and type 2 diabetes (T2D) risk among 7333 Korean adults aged 40 years or older who were included in the Multi-Rural Communities Cohort. Dietary folate intake was estimated from all 106 food items listed on a FFQ, not including folate intake from supplements. Two different measurements of dietary folate intake were used: the baseline consumption and the average consumption from baseline until just before the end of follow-up. The association between folate intake and T2D risk was determined through a modified Poisson regression model with a robust error estimator controlling for potential confounders. For 29 745 person years, 319 cases of diabetes were ascertained. In multivariable analyses, dietary folate intake was inversely associated with risk of T2D for women, not for men. For women, the incidence rate ratio of diabetes in the third tertile compared with the first tertile was 0·57 (95 % CI 0·38–0·87, Pfor trend=0·0085) in the baseline consumption model and 0·64 (95 % CI 0·43–0·95, Pfor trend=0·0244) in the average consumption model. These inverse associations was found in both normal fasting blood glucose group and impaired fasting glucose group among women. Among non-users of multinutrients and vitamin supplements, the significant inverse association remained. Thus, higher dietary intake of folate is prospectively associated with lower risk of diabetes for women. [ABSTRACT FROM PUBLISHER]

Background and Aims Resistance rates of Helicobacter pylori to clarithromycin, metronidazole, and quinolone are over 30% in South Korea. The aim of this prospective study was to evaluate the ultimate eradication rate of H. pylori after first, second, or third-line therapy in Korea. Methods A cohort of 2202 patients with H. pylori was treated with proton pump inhibitor ( PPI)-based triple therapy for seven days. In case of treatment failure or recurrence, moxifloxacin-based triple therapy ( MA) or bismuth-based quadruple therapy ( QUAD) was randomly given. When the second-line treatment failed or H. pylori recurred, the unused MA or QUAD was used as a third-line treatment. Results Eighty-six patients had recurrence at least once during consecutive lines of treatments. Among 2116 patients (intention-to-treat [ ITT]) without recurrence, 1644 (77.7%, per-protocol [ PP]) completely followed our treatment flow. The ITT and PP rates of first-line treatment were 69.8% and 89.3%. After second line, they reached 78.4% ( ITT) and 98.4% ( PP). The 'final' eradication rate up to third line treatment were 80.0% (1692/2116) and 99.8% (1641/1644), respectively. Resistance to clarithromycin showed significantly lower eradication rate ( OR 0.358, P < 0.001) than those with susceptible strains in multivariate analysis. However in PP analysis, there was no significant difference in ultimate success rate regarding resistance pattern. Conclusion Final success rate of PP was high, 99.8% in Korea in spite of high antibiotic resistance rates. However, high rate of refusal of further treatment and follow-up loss made ITT eradication rate low. Proper strategy to improve the treatment adherence is needed. [ABSTRACT FROM AUTHOR]

Background and Aim: Gastric cancer is believed to develop by a multistage process. Intestinal metaplasia (IM) is regarded as a premalignant condition; it is classified into subtypes I, II and III. The aim of this study was to evaluate whether the subtypes of IM were associated with progression to gastric cancer. Methods: The study cohort consisted of 861 subjects, categorized as controls, gastric ulcers, dysplasia and cancer. The IM was scored histologically using the Sydney classification for the antrum and the body of the stomach. The biopsies were stained with high iron diamine and alcian blue (pH 2.5) (HID-AB2.5), and the IM was subtyped as I, II or III. Results: The proportion of IM subtypes I, II and III were 14.5%, 47.2% and 38.3% in the antrum, and 28.1%, 57.8% and 14.1% in the body of the stomach, respectively. These distributions did not show significant differences depending on disease or Helicobacter pylori positivity. In cases that were H. pylori-positive, the prevalence of IM subtype II in the cancer and dysplasia groups was higher than in the control group in the body of the stomach ( P < 0.05). The proportion of IM subtype III in the antrum increased in proportion with age ( P = 0.036). Conclusions: IM subtyping was not found to play a major role in the prediction of gastric cancer development in Korea. IM subtype III was associated with aging, and IM subtype II appeared to be related to gastric carcinogenesis in the presence of H. pylori infection. [ABSTRACT FROM AUTHOR]

Purpose - This paper seeks to investigate the prospects for internet protocol TV (IPTV) from the social, economic and regulatory perspective to gain a better understanding of how IPTV will evolve and stabilize in next generation network environments. Design/methodology/approach - Qualitative and quantitative data were collected from multiple data collection methods. The analysis is based on theoretical frameworks derived from socio-technical theories and web of stakeholder analyses. Findings - From the socio-technical analysis, the development of IPTV implies that IPTV has been through internally-driven change (more or less technology-driven and regulatory-constrained), but from now on it will likely be driven by external factors (market and user). The web of stakeholder analysis implies that the further development of lPTV in Korea is likely to comprise multiple stages, predicated by several significant events: the deployment of Broadband Convergence Network and F7TH, the resolving of content issues, establishing standards, and the introduction of new regulatory frameworks. Practical implications - The case of Korea offers implications for other countries that are pursuing IPTV development strategies. Originality/value - By looking at IPTV as a sociotechnical ensemble, this paper seeks a firm understanding of the interaction among IPTV technology its market, industry, and regulation regarding IPTV. A stakeholder analysis helps this study to address such interactions. [ABSTRACT FROM AUTHOR]