• Title/Summary/Keyword: Field exposure

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Effect of Valeriana fauriei Extract on the Neurodevelopmental Proteins Expression and Behavioral Patterns in Maternal Immune Activation Animal Model (쥐오줌풀 추출물이 MIA동물모델에서의 신경발달 단백질의 발현과 행동증상에 미치는 영향)

  • Won, Hansol;Kim, Young Ock;Lee, Hwayoung;Im, Jiyun;Lee, Sanghyun;Cho, Ik Hyun;Lee, Sang Won;Park, Chun Geun;Kim, Hyung Ki;Kwon, Jun Tack;Kim, Hak Jae
    • Korean Journal of Medicinal Crop Science
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    • v.24 no.5
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    • pp.341-350
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    • 2016
  • Background: Prenatal exposure to infectious and/or inflammatory insults can increase the risk of developing neuropsychiatric disorder such as bipolar disorder, autism, and schizophrenia later in life. We investigated whether Valeriana fauriei (VF) treatment alleviates prepulse inhibition (PPI) deficits and social interaction impairment induced by maternal immune activation (MIA). Methods and Results: Pregnant mice were exposed to polyriboinosinic-polyribocytidilic acid (5 mg/kg, viral infection mimic) on gestational day 9. The adolescent offspring received daily oral treatment with VF (100 mg/kg) and injections of clozapine (5 mg/kg) for 30 days starting on the postnatal day 35. The effects of VF extract treatment on behavioral activity impairment and protein expression were investigated using the PPI analysis, forced swim test (FST), open field test (OFT), social interaction test (SIT), and immunohistochemistry. The MIA-induced offspring showed deficits in the PPI, FST, OFT, and SIT compared to their non MIA-induced counterparts. Treatment with the VF extract significantly recovered the sensorimotor gating deficits and partially recovered the aggressive behavior observed in the SIT. The VF extract also reversed the downregulation of protein expression induced by MIA in the medial prefrontal cortex. Conclusions: Our results provide initial evidence of the fact that the VF extract could reverse MIA-induced behavioral impairment and prevent neurodevelopmental disorders such as schizophrenia.

Development and Verification of Eco-hybrid Rolling Mat for Preventing Bank Erosion Based on Large-scale Experiments (실규모 하천 실험을 통한 하안침식 방지 Eco-hybrid 롤링매트 공법 개발 및 검증)

  • Ji, Un;Jang, Eun-Kyung;Ahn, Myeonghui;Kim, Won
    • Ecology and Resilient Infrastructure
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    • v.6 no.4
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    • pp.217-226
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    • 2019
  • Optimum engineering methods for bank protection were classified based on steepness of bank slope and an existence of waterfront facility in the floodplain, and a new concept of eco-hybrid rolling mat method which could be applicable for the unfitted cases with previously developed countermeasures was suggested in this study. The eco-hybrid rolling mat method can be constructed while maintaining the river environment and ecosystem that does not interfere with the ground and slopes, when bank erosion occurs, it is an economical and efficient construction method that can protect the revetment and the bank slope immediately. The developed eco-hybrid rolling mat method was verified for the designed structure, system, function and effect based on large-scale river experiments including field exposure and decomposition test. As a result, the normal operation and effect of the rolling mat ted under low and high velocity conditions were confirmed with respect to bank protection. The effect of bank erosion prevention was quantitatively validated by sediment concentration monitoring and analysis, and the product specification of the eco-hybrid rolling mat was presented based on the standardized mat applied in real-scale tests.

Estimating Groundwater Level Variation due to the Construction of a Large Borrow Site using MODFLOW Numerical Modeling (대규모 토취장 개발 예정 지역의 수치모델을 이용한 지하수위 변동 예측)

  • Ryu, Sanghun;Park, Joonhyeong;Kim, Gyoobum
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.10
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    • pp.15-23
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    • 2012
  • A numerical model and field monitoring data are used to estimate a change in groundwater level at a borrow site, which will be constructed at the mountainous area with a large ground excavation in the study area, Hwaseong city. Lithologic data and hydraulic coefficients are collected at 9 boreholes and also groundwater levels are measured at these boreholes and existing wells in the study area. Additionally, groundwater recharge rate for the type of land cover is estimated using water budget analysis; 133.34mm/year for a mountainous area, 157.68mm/year for a farming area, 71.08mm/year for an urbanized area, and 26.06mm/year for a bedrock exposure area. The change in groundwater level in and around a borrow site is simulated with Modflow using these data. The result of a transient model indicates that a removal of high ground (over 40El.m) by an excavation will produce a decrease in groundwater levels, up to 1 m, around a borrow site in 10 years. It also explains that this ground excavation will bring about the decreases of 9.4% and 7.0% for groundwater recharge and surface runoff, respectively, which are the factors causing groundwater level's change. This study shows that it is required to construct the groundwater monitoring wells to observe the change of groundwater near a borrow site.

Alternaria mycotoxins and its incidence in fruits and vegetables

  • Patriarca, Andrea
    • 한국균학회소식:학술대회논문집
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    • 2018.05a
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    • pp.13-13
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    • 2018
  • Alternaria is a ubiquitous fungal genus, widely distributed in the environment and a range of different habitats. It includes both plant pathogenic and saprophytic species, which can affect crops in the field or cause post-harvest spoilage of plant fruits and kernels. Numerous Alternaria species cause damage to agricultural products including cereal grains, fruits and vegetables, and are responsible for severe economic losses worldwide. Most Alternaria species have the ability to produce a variety of secondary metabolites, which may play important roles in plant pathology as well as food quality and safety. Alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), tentoxin (TEN) and altenuene (ALT) are considered the main Alternaria compounds thought to pose a risk to human health. However, food-borne Alternaria species are able to produce many additional metabolites, whose toxicity has been tested incompletely or not tested at all. Both alternariols are mutagenic and their presence in cereal grain has been associated with high levels of human esophageal cancer in China. TeA exerts cytotoxic and phytotoxic properties, and is acutely toxic in different animal species, causing hemorrhages in several organs. The possible involvement of TA in the etiology of onyalai, a human hematological disorder occurring in Africa, has been suggested. Altertoxins (ALXs) have been found to be more potent mutagens and acutely toxic to mice than AOH and AME. Other metabolites, such as TEN, are reported to be phytotoxins, and their toxicity on animals has not been demonstrated up to now. Vegetable foods infected by Alternaria rot are obviously not suitable for consumption. Thus, whole fresh fruits are not believed to contribute significantly with Alternaria toxins to human exposure. However, processed vegetable products may introduce considerable amounts of these toxins to the human diet if decayed or moldy fruit is not removed before processing. The taxonomy of the genus is not well defined yet, which makes it difficult to establish an accurate relationship between the contaminant species and their associated mycotoxins. Great efforts have been made to organize taxa into subgeneric taxonomic levels, especially for the small-spored, food associated species, which are closely related and constitute the most relevant food pathogens from this genus. Several crops of agricultural value are susceptible to infection by different Alternaria species and can contribute to the entry of Alternaria mycotoxins in the food chain. The distribution of Alternaria species was studied in different commodities grown in Argentina. These food populations were characterized through a polyphasic approach, with special interest in their secondary metabolite profiles, to understand their full chemical potential. Alternaria species associated with tomato, bell pepper, blueberry, apples and wheat cultivated in Argentina showed a surprisingly high metabolomic and mycotoxigenic potential. The natural occurrence of Alternaria toxins in these foods was also investigated. The results here presented will provide background for discussion on regulations for Alternaria toxins in foods.

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The Influence of Environmental Variables on Distribution of Macrobenthic Community in Salt Marsh Vegetation in Donggeomdo, Ganghwa on the West Coast of Korea (강화 동검도 염습지 식생의 대형저서동물군집 분포에 영향을 주는 환경요인)

  • Lee, Hyung-Gon;Yoon, Kon-Tak;Park, Heung-Sik;Hong, Jae-Sang;Lee, Jae-Hac
    • Ocean and Polar Research
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    • v.38 no.2
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    • pp.115-128
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    • 2016
  • This study examined the relationship between macrobenthic distribution patterns and environmental factors in salt marsh vegetation in Donggeomdo, Ganghwa on the west coast of Korea. Nine stations were fixed on a transect across the salt marsh vegetation, and field sampling was carried out monthly from July 1997 to June 1998. A total of 38 species of macrobenthos were recorded: each of faunal groups, 13 (34.2%) Arthropoda, 12 (31.6%) Polychaeta, 8 (21.1%) Mollusca, and 5 (13.2%) others. The mean density was $2,659individuals/m^2$, with a mean biomass of $178.6gWWt/m^2$. Mollusca dominated in terms of abundance and biomass, with a mean density of $2,172individuals/m^2$ (81.7%) and a mean biomass of $131.9gWWt/m^2$ (73.9%). The number of species decreased in winter (January-February), while mean density increased in the spring (May-June). The biomass was relatively in Summer and Fall (July-November), than any other season. The number of species was high in pure stands of Suaeda japonica in the lower salt marsh vegetation, and the mean density and biomass were high in mixed halophyte communities in the middle salt marsh vegetation. Two Mollusca, the bivalve Glauconome chinensis and gastropod Assiminea lutea, were dominant. The densities of these two species were high in mixed halophyte communities in the middle salt marsh vegetation. Non-metric multi-dimensional scaling (nMDS) showed that the study area could be divided into four groups corresponding to the vertical distribution of tidal levels and halophytes. Spearman's rank correlation revealed that the distribution patterns and community structure of macrobenthos were related to environment variables such as salinity of the substrates, exposure time, and grain size compositions of the sediment in the salt marsh vegetation. Particularly, the distribution and density of some dominant species showed differences along the vertical distributions of halophytes.

Persistence and degradation of herbicide molinate in paddy-soil environment (논토양 환경 중 제초제 molinate의 잔류성과 분해특성)

  • Park, Byung-Jun;Park, Hyeon-Ju;Lee, Byung-Moo;Ihm, Yang-Bin;Choi, Ju-Hyeon;Ryu, Gab-Hee
    • The Korean Journal of Pesticide Science
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    • v.9 no.1
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    • pp.60-69
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    • 2005
  • The herbicide molinate has been detected with high frequency in the main river during the growing season in Korea. To elucidate the exposure of molinate in agricultural environment, the persistence and the degradation characteristics of molinate were investigated in paddy ecosystems. The half-lives of molinate were 4.1 days with soil aquatic system, and 4.2 days in only aquatic system. Initial dissipation rate of molinate in water was greater with soil aquatic system than that of only aquatic system. Photolysis of molinate was occurred about 31.0% of molinate treated in pure water, when irradiated at 5,530 $J/cm^2$ by the xenon lamp, but its hydrolysis was stable. For the accelerated photolysis of molinate in aqueous solution, several photosensitizers were screened, showing that the hydroperoxide($H_2O_2$) and acetone were prominent among the chemical tested. When hydroperoxide and zinkoxide(ZnO) were used as photosensitizer, their photolysis were accelerated greater than 98% and 58% in aqueous solution, respectively. Elution rate of molinate as granular formulations in aqueous system was more than 90% in 30 hour at $35^{\circ}C$. Molinate concentration pattern in paddy water was rapidly decrease from treatment till 7 days in paddy rice field and its half-lives were 3.7 days($Y=1.9258{\times}e^{-0.1865X}$(r=-0.9402)).

IGRINS First Light Instrumental Performance

  • Park, Chan;Yuk, In-Soo;Chun, Moo-Young;Pak, Soojong;Kim, Kang-Min;Pavel, Michael;Lee, Hanshin;Oh, Heeyoung;Jeong, Ueejeong;Sim, Chae Kyung;Lee, Hye-In;Le, Huynh Anh Nguyen;Strubhar, Joseph;Gully-Santiago, Michael;Oh, Jae Sok;Cha, Sang-Mok;Moon, Bongkon;Park, Kwijong;Brooks, Cynthia;Ko, Kyeongyeon;Han, Jeong-Yeol;Nah, Jakyuong;Hill, Peter C.;Lee, Sungho;Barnes, Stuart;Park, Byeong-Gon;T., Daniel
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.52.2-52.2
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    • 2014
  • The Immersion Grating Infrared Spectrometer (IGRINS) is an unprecedentedly minimized infrared cross-dispersed echelle spectrograph with a high-resolution and high-sensitivity optical performance. A silicon immersion grating features the instrument for the first time in this field. IGRINS will cover the entire portion of the wavelength range between 1.45 and $2.45{\mu}m$ accessible from the ground in a single exposure with spectral resolution of 40,000. Individual volume phase holographic (VPH) gratings serve as cross-dispersing elements for separate spectrograph arms covering the H and K bands. On the 2.7m Harlan J. Smith telescope at the McDonald Observatory, the slit size is $1^{\prime\prime}{\times}15^{\prime\prime}$. IGRINS has a $0.27^{\prime\prime}$ pixel-1 plate scale on a $2048{\times}2048$ pixel Teledyne Scientific & Imaging HAWAII-2RG detector with SIDECAR ASIC cryogenic controller. The instrument includes four subsystems; a calibration unit, an input relay optics module, a slit-viewing camera, and nearly identical H and K spectrograph modules. The use of a silicon immersion grating and a compact white pupil design allows the spectrograph collimated beam size to be 25mm, which permits the entire cryogenic system to be contained in a moderately sized rectangular vacuum chamber. The fabrication and assembly of the optical and mechanical hardware components were completed in 2013. In this presentation, we describe the major design characteristics of the instrument and the early performance estimated from the first light commissioning at the McDonald Observatory.

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Current Status of the KMTNet Active Nuclei Variability Survey (KANVaS)

  • Kim, Joonho;Karouzos, Marios;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.54.1-54.1
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    • 2016
  • Multi-wavelength variability is a staple of active galactic nuclei (AGN). Optical variability probes the nature of the central engine of AGN at smaller linear scales than conventional imaging and spectroscopic techniques. Previous studies have shown that optical variability is more prevalent at longer timescales and at shorter wavelengths. Intra-night variability can be explained through the damped random walk model but small samples and inhomogeneous data have made constraining this model hard. To understand the properties and physical mechanism of intra-night optical variability, we are performing the KMTNet Active Nuclei Variability Survey (KANVaS). Using KMTNet, we aim to study the intra-night variability of ~1000 AGN at a magnitude depth of ~19mag in R band over a total area of ${\sim}24deg^2$ on the sky. Test data in the COSMOS, XMM-LSS, and S82-2 fields was obtained over 4, 6, and 8 nights respectively during 2015, in B, V, R, and I bands. Each night was composed of 5-13 epoch with ~30 min cadence and 80-120 sec exposure times. As a pilot study, we analyzed data in the COSMOS field where we reach a magnitude depth of ~19.5 in R band (at S/N~100) with seeing varying between 1.5-2.0 arcsec. We used the Chandra-COSMOS catalog to identify 166 AGNs among 549 AGNs at B<23. We performed differential photometry between the selected AGN and nearby stars, achieving photometric uncertainty ~0.01mag. We employ various standard time-series analysis tools to identify variable AGN, including the chi-square test. Preliminarily results indicate that intra-night variability is found for ~17%, 17%, 8% and 7% of all X-ray selected AGN in the B, V, R, and I band, respectively. The majority of the identified variable AGN are classified as Type 1 AGN, with only a handful of Type 2 AGN showing evidence for variability. The work done so far confirms there are more variable AGN at shorter wavelengths and that intra-night variability most likely originates in the accretion disk of these objects. We will briefly discuss the quality of the data, challenges we encountered, solutions we employed for this work, and our updated future plans.

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Evaluation of Foodservice Managers' Perception on Safety Management in Childcare Centers and Kindergartens (보육시설 및 유치원 급식 관리자의 위생관리 인식도 조사)

  • Park, Hyung-Soo;Lee, Kyung-Mi;Seol, Hye-Rin;Park, Ki-Hwan;Ryu, Kyung
    • Korean Journal of Community Nutrition
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    • v.14 no.1
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    • pp.87-99
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    • 2009
  • The purpose of this study was to investigate the perception of foodservice managers in childcare centers and kindergartens for identifying the vulnerable areas of safety management. The foodservice managers in 1,144 of nationwide childcare centers and kindergartens were surveyed from May to October 2007 to answer a total 72 questions in areas of general characteristics, actual practice of foodservice management and safety management perception. Meals were served in 97.7% of surveyed facilities and 91.0% among them were self-operated. The hiring rate (27.8%) of dietitians in childcare centers was significantly lower than the rate (82.0%) of kindergartens. The needs of dietitian employment between childcare centers and kindergartens differed as 44.9% and 87.5%, respectively. In knowledge on food-borne illnesses, they have the wrong information in the field of season for frequent outbreak, major pathogens and foods causing food-borne illnesses. The food-borne illnesses (36.2%) were indicated as the major problem in foodservice facilities and the degree of risk exposure was considered as safe (70.1%). More than 70% of both facilities answered as sanitary in the status of personal hygiene. Only 38.0% recognized the Facility and Equipment Standard in the Childcare Law and Early Childhood Education Law. In preparation of meals and management of cooking processes, kindergarten scored significantly high compared to childcare centers (p < 0.05 or p < 0.01) while the necessity of standards was not different in both facilities. Among managers surveyed, 28.8% had taken food safety education from professional institutions and more than 80% in both facilities indicated the need of professional educations. These results suggest that it is necessary for the systematic sanitary education of foodservice managers by developing the sanitary management standard as well as the amendment of laws related foodservice in childcare centers and kindergartens.

Treatment of crown-root fracture with a modified crown fragment reattachment technique (변형된 치관부 파절편 재부착술식을 이용한 치관치근파절의 치료)

  • Song, Chang-Won;Song, Min-Ju;Shin, Su-Jung;Park, Jeong-Won
    • Restorative Dentistry and Endodontics
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    • v.35 no.5
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    • pp.395-400
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    • 2010
  • The development of adhesive dentistry has allowed that the crown fragment reattachment can be another option in the treatment of crown fracture. However, additional crown lengthening procedure or extrusion of the tooth may be necessary in the treatment of crown root fracture because subgingival fracture line in close proximity to the alveolar bone leads to challenges for restorative procedure and the violation of the biologic width. This case report presents a modified crown fragment reattachment technique of crown root fracture with pulp exposure, which was done without additional crown lengthening procedures. After the endodontic treatment, the patient was treated using a post insertion and the fragment reattachment technique, which made it possible to preserve the space for the biologic width and maintain a dry surgical field for adequate adhesion through the modification of the fractured coronal fragment. Since a coronal fracture was occurred and reattached afterward, it was observed that the coronal fragment was well maintained without the additional loss of periodontal attachment through 2-year follow up.