• Journal of Ecology and Environment
• /
• v.47 no.2
• /
• pp.14-26
• /
• 2023

Background: An important consideration for the risk assessment of transgenic plants is their overwintering potential in a natural ecosystem, which allows the survival of the seed bank and may lead to seed reproduction. Here, we investigated the overwintering of sunflower (Helianthus annuus L.) seeds in the laboratory (temperatures: -5, -1, 5, and 10℃) and in the field (burial depth: 0, 5, 15, and 30 cm) as a case study to examine the invasiveness of transgenic crops. Results: Sunflower seeds germinated when incubated at 5℃ and 10℃ for 2, 4, 6, and 12 weeks but not when incubated at -5℃ or -1℃. However, the seeds incubated at -5℃ or -1℃ germinated when they were transferred to the optimal germination temperature (25℃). Up to 16.5% and 15.0% of seeds were dormant when cultured at sub-zero temperatures in a Petri dish containing filter paper and soil, respectively. In the field trial, soil temperature, moisture, and microbial communities differed significantly between soil depths. Germination-related microorganisms were more distributed on the soil surface. Seeds buried on the surface decayed rapidly from 4 weeks after burial, whereas those buried at depths of 15 cm and 30 cm germinated even 16 weeks after burial. No dormancy was detected for seeds buried at any depth. Conclusions: Although sunflower seeds did not overwinter in situ in this study, we cannot exclude the possibility that these seeds lie dormant at sub-zero temperatures and then germinate at optimal temperatures in nature.

• Korean Journal of Radiology
• /
• v.25 no.1
• /
• pp.103-112
• /
• 2024

Objective: To investigate the association of ultrasound (US) features of follicular thyroid carcinoma (FTC) with tumor invasiveness and prognosis based on the World Health Organization (WHO) classification and telomerase reverse transcriptase (TERT) promoter mutations. Materials and Methods: This retrospective study included 54 surgically confirmed FTC patients with US images and TERT promoter mutations (41 females and 13 males; median age [interquartile range], 40 years [30-51 years]). The WHO classification consisted of minimally invasive (MI), encapsulated angioinvasive (EA), and widely invasive (WI) FTCs. Alternative classifications included Group 1 (MI-FTC and EA-FTC with wild type TERT), Group 2 (WI-FTC with wild type TERT), and Group 3 (EA-FTC and WI-FTC with mutant TERT). Each nodule was categorized according to the US patterns of the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and American College of Radiology-TIRADS (ACR-TIRADS). The Jonckheere-Terpstra and Cochran-Armitage tests were used for statistical analysis. Results: Among 54 patients, 29 (53.7%) had MI-FTC, 16 (29.6%) had EA-FTC, and nine (16.7%) had WI-FTC. In both the classifications, lobulation, irregular margins, and final assessment categories showed significant differences (all Ps ≤ 0.04). Furthermore, the incidences of lobulation, irregular margin, and high suspicion category tended to increase with increasing tumor invasiveness and worse prognosis (all Ps for trend ≤ 0.006). In the WHO groups, hypoechogenicity differed significantly among the groups (P = 0.01) and tended to increase in proportion as tumor invasiveness increased (P for trend = 0.02). In the alternative group, punctate echogenic foci were associated with prognosis (P = 0.03, P for trend = 0.03). Conclusion: Increasing tumor invasiveness and worsening prognosis in FTC based on the WHO classification and TERT promoter mutation results were positively correlated with US features that indicate malignant probability according to both K-TIRADS and ACR-TIRADS.

• Korean Journal of Plant Resources
• /
• v.32 no.6
• /
• pp.752-757
• /
• 2019

The establishment of invasive alien species management is widely recognized as a pivotal issue in the preservation of biodiversity. Ranunculus sardous Crantz, a species native to Europe, has been widely introduced in many other areas of the world, including the coasts of the United States, Australia, China, India, and Japan. In Korea, the first population of this plant was found growing adjacent to a wetland in Hanon, Seogwipo-si, Jeju Province, on 22 May 2018. Field observations confirmed the presences of at least two populations of this species in Jeju Province, Korea. This species is similar to Ranunculus sceleratus L., but can be readily distinguished by its presence of the trichomes in the whole plant, longer petioles of radical leaves, ovate-shaped leaf segments, globose to subglobose-shaped fruits and flat achenes with narrowly winged and papillae. The Invasive Alien Plant Risk Assessment (IAPRA), a system for recognizing and categorizing alien plants in Korea forests, was used to assess the invasiveness status of the species. Based on this system, R. sardous received a low score of 6, suggesting its potential invasion to natural forests. Although the current distribution of R. sardous is restricted to Jeju Province and thus far has had limited impact on local environments, local and regulatory authorities should pay close attention to this plant and take measures to prevent its further expansion.

• Earthquakes and Structures
• /
• v.11 no.2
• /
• pp.195-215
• /
• 2016

Rehabilitation of historical unreinforced masonry (URM) buildings is a priority in many parts of the world, since those buildings are a living part of history and a testament of human achievement of the era of their construction. Many of these buildings are still operational; comprising brittle materials with no reinforcements, with spatially distributed mass and stiffness, they are not encompassed by current seismic assessment procedures that have been developed for other structural types. To facilitate the difficult task of selecting a proper rehabilitation strategy - often restricted by international treaties for non-invasiveness and reversibility of the intervention - and given the practical requirements for the buildings' intended reuse, this paper presents a practical procedure for assessment of seismic demands of URM buildings - mainly historical constructions that lack a well-defined diaphragm action. A key ingredient of the method is approximation of the spatial shape of lateral translation, ${\Phi}$, that the building assumes when subjected to a uniform field of lateral acceleration. Using ${\Phi}$ as a 3-D shape function, the dynamic response of the system is evaluated, using the concepts of SDOF approximation of continuous systems. This enables determination of the envelope of the developed deformations and the tendency for deformation and damage localization throughout the examined building for a given design earthquake scenario. Deformation demands are specified in terms of relative drift ratios referring to the in-plane and the out-of-plane seismic response of the building's structural elements. Drift ratio demands are compared with drift capacities associated with predefined performance limits. The accuracy of the introduced procedure is evaluated through (a) comparison of the response profiles with those obtained from detailed time-history dynamic analysis using a suite of ten strong ground motion records, five of which with near-field characteristics, and (b) evaluation of the performance assessment results with observations reported in reconnaissance reports of the field performance of two neoclassical torsionally-sensitive historical buildings, located in Thessaloniki, Greece, which survived a major earthquake in the past.

• Korean Journal of Plant Taxonomy
• /
• v.51 no.1
• /
• pp.10-17
• /
• 2021

Invasive alien species management is pivotal for biodiversity conservation. Commelina caroliniana Walter, from the family Commelinaceae, is an alien plant native to the Himalayas and India, but it has been widely introduced around the world, including in the United States, Brazil, Philippines, and Japan. In Korea, the first population was found growing adjacent to agricultural land and farm roads on Jejudo Island, and field observations confirmed the presence of at least nine populations there. It is similar morphologically to C. diffusa Burm. f. but can be distinguished by involucral bracts that are ciliate at the base, hairs on the peduncle and obsolete upper cincinnus, brown spots on its 4-lobed antherode, and seed surfaces that are smooth to slightly alveolate. It was determined to have an invasiveness low score of 8 according to the Korean 'Invasive Alien Plant Risk Assessment', suggesting that it may spread to natural habitats. Although the current distribution of C. caroliniana is restricted to Jeju-si, it has spread dramatically in many other areas of the world. At present, it has had a limited impact on the local environment, but local and regulatory authorities should pay close attention to this plant and take measures to prevent its expansion in the future.

• Journal of Veterinary Clinics
• /
• v.18 no.3
• /
• pp.279-283
• /
• 2001

Eleven years old cocker spaniel referred to Veterianry Medical Teaching Hospital, Seoul National University was diagnosed as pheochromocytoma. The patient was transferred to the hospital after hit by car and the main clinical signs were tachypnea, tachycardia, edema of hindlimb and lethargy. On ultrasonographic examination, hyperechoic foci was detected and it was invaded into the caudal vena cava. Venography showed the filling defect and local dilation of the caudal vena. The diagnosis of pheochromocytoma is challenging due to the nonspecific clinical signs and severe concurrent disease in dogs. This report describes one dog with invasive pheochromocytoma in which radiography, ultrasonography and venacavography were key diagnositc tools. Ultrasonography was a usuful method for assessment of size, shape and margination of the tumor and invasiveness to the major vessels.

• Korean Journal of Environmental Biology
• /
• v.39 no.2
• /
• pp.207-217
• /
• 2021

Using the data from the national survey of fish, we determined the population size and the distribution of Micropterus salmoides, which is a translocated species into the aquatic ecosystem of Korea. . The spatial concentration of this species was determined by performing an optimized hot spot analysis. After determining potential invasiveness and risk assessment, we measured the disturbance of biodiversity in the aquatic ecosystem. The result of distribution analysis indicates that the population of M. salmoides was concentrated in the major basins of Han river, Geum river, Nakdong river, and Yeongsan-Seomjin river, including the Jeju island. In particular, Nakdong river basin showed the highest appearance rate. On the contrary, Yeongsan-Seomjin river basin showed the lowest appearance rate. The Nakdong river and the Nakdong river basin were the areas with the high spatial concentration of M. salmoides. On the other hand, only Han river basin and Geum river basin had the lowest spatial concentration. The fish invasiveness screening kit(FISK) was used to assess M. salmoides, which inhabited a broad region of aquatic ecosystem: the assessment score was 31.0, indicating its 'highly invasive' nature. Our study aims to encourage research that improves the biodiversity and the conservation of M. salmoides in a priority area.

• Ecology and Resilient Infrastructure
• /
• v.2 no.3
• /
• pp.191-197
• /
• 2015

Invasive alien species are considered to be one of the main factors that cause biodiversity loss. Establishment of management strategies through continuous monitoring and risk assessment is a key element for invasive alien species management policy. In the present study, we introduce examples of ecological risk assessment tools developed in Japan, Germany-Austria and Belgium. Invasive alien species have been designated in Japan based on the assessment of risks to ecosystems, human health and primary industry. German-Austrian Black List Information System categorized alien species into Black List, White List and Grey List according to their risks to biodiversity. In the Harmonia Information System developed in Belgium, invasiveness, adverse impacts on native species and ecosystem functions and invasion stages were assessed and alien species were categorized into Black List, Watch List and Alert List. These international risk assessment tools may be helpful to improve our national risk assessment protocol for the prioritization of invasive alien species management.

• Clinical Endoscopy
• /
• v.56 no.5
• /
• pp.537-545
• /
• 2023

Achalasia is an esophageal motility disorder characterized by impaired lower esophageal sphincter relaxation and peristalsis of the esophageal body. With the increasing prevalence of achalasia, interest in the role of endoscopy in its diagnosis, treatment, and monitoring is also growing. The major diagnostic modalities for achalasia include high-resolution manometry, esophagogastroduodenoscopy, and barium esophagography. Endoscopic assessment is important for early diagnosis to rule out diseases that mimic achalasia symptoms, such as pseudo-achalasia, esophageal cancer, esophageal webs, and eosinophilic esophagitis. The major endoscopic characteristics suggestive of achalasia include a widened esophageal lumen and food residue in the esophagus. Once diagnosed, achalasia can be treated either endoscopically or surgically. The preference for endoscopic treatment is increasing owing to its minimal invasiveness. Botulinum toxins, pneumatic balloon dilation, and peroral endoscopic myotomy (POEM) are important endoscopic treatments. Previous studies have demonstrated excellent treatment outcomes for POEM, with >95% improvement in dysphagia, making POEM the mainstay treatment option for achalasia. Several studies have reported an increased risk of esophageal cancer in patients with achalasia. However, routine endoscopic surveillance remains controversial owing to the lack of sufficient data. Further studies on surveillance methods and duration are warranted to establish concordant guidelines for the endoscopic surveillance of achalasia.

• Journal of Ecology and Environment
• /
• v.48 no.3
• /
• pp.277-284
• /
• 2024

Background: Newly introduced transgenic plants can outcompete native species in natural ecosystems, threatening the biodiversity of a country. This study ascertained the weediness potential of plants according to the seed amount under the assumption that transgenic seeds were unintentionally spilled. Using sunflowers as the study system, 0, 50, 100, and 150 seeds were sown in 1 m × 1 m and 2 m × 2 m plots, and seed germination, survival, flowering, and competition between the surviving and wild plants were investigated. Results: There was no significant difference in the germination rate of sunflowers depending on the cultivar, but differences were observed depending on the sowing density and plot size. As the number of seeds sown increased, the flowering and seed maturation of sprouted plants occurred earlier; the plant height and flower length of the surviving plants decreased. In addition, as the number of seeds increased, not only did the early importance of sunflowers increase, but the period of dominance over weeds also improved. Conclusions: These results suggest that the weediness potential of sunflowers varies with the number of seeds at the time of release, which may affect germination and growth, and compete with weeds in transgenic plants.