183 research outputs found
Assessment of Agricultural Drought Considering the Hydrological Cycle and Crop Phenology in the Korean Peninsula
Hydrological changes attributable to global warming increase the severity and frequency of droughts, which in turn affect agriculture. Hence, we proposed the Standardized Agricultural Drought Index (SADI), which is a new drought index specialized for agriculture and crops, and evaluated current and expected droughts in the Korean Peninsula. The SADI applies crop phenology to the hydrological cycle, which is a basic element that assesses drought. The SADI of rice and maize was calculated using representative hydrological variables (precipitation, evapotranspiration, and runoff) of the crop growing season. In order to evaluate the effectiveness of SADI, the three-month Standardized Precipitation Index, which is a representative drought index, and rainfed crop yield were estimated together. The performance evaluation of SADI showed that the correlation between rainfed crop yield and SADI was very high compared with that of existing drought index. The results of the assessment of drought over the past three decades provided a good indication of a major drought period and differentiated the results for crops and regions. The results of two future scenarios showed common drought risks in the western plains of North Korea. Successfully validated SADIs could be effectively applied to agricultural drought assessments in light of future climate change, and would be a good example of the water-food nexus approach
Assessment of Agricultural Drought Considering the Hydrological Cycle and Crop Phenology in the Korean Peninsula
Hydrological changes attributable to global warming increase the severity and frequency of droughts, which in turn affect agriculture. Hence, we proposed the Standardized Agricultural Drought Index (SADI), which is a new drought index specialized for agriculture and crops, and evaluated current and expected droughts in the Korean Peninsula. The SADI applies crop phenology to the hydrological cycle, which is a basic element that assesses drought. The SADI of rice and maize was calculated using representative hydrological variables (precipitation, evapotranspiration, and runoff) of the crop growing season. In order to evaluate the effectiveness of SADI, the three-month Standardized Precipitation Index, which is a representative drought index, and rainfed crop yield were estimated together. The performance evaluation of SADI showed that the correlation between rainfed crop yield and SADI was very high compared with that of existing drought index. The results of the assessment of drought over the past three decades provided a good indication of a major drought period and differentiated the results for crops and regions. The results of two future scenarios showed common drought risks in the western plains of North Korea. Successfully validated SADIs could be effectively applied to agricultural drought assessments in light of future climate change, and would be a good example of the water-food nexus approach
Anti-Inflammatory Activity of the Methanol Extract of Moutan Cortex in LPS-Activated Raw264.7 Cells
Moutan Cortex (MCE) has been used in traditional medicine to remove heat from the blood, promote blood circulation and alleviate blood stasis. This study was conducted to evaluate the effects of MCE on regulatory mechanisms of cytokines and nitric oxide (NO) involved in immunological activity of Raw264.7 cells. Cells were pretreated with methanolic extracts of MCE, and further cultured for an appropriate time after lipopolyssacharide (LPS) addition. During the entire experimental period, 0.1 and 0.3 mg ml−1 of MCE had no cytotoxicity. In these concentrations, MCE inhibited the production of NO and prostaglandin E2 (PGE2), the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and phosphorylated inhibitor of κBα (p-IκBα), and the activation of nuclear factor κB (NF-κB). MCE also reduced the concentration of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in the Raw264.7 cells that were activated by LPS. These results demonstrate that MCE has anti-inflammatory effects through the inhibition of iNOS and COX-2 expression by suppressing the phosphorylation of I-κBα and the activation of NF-κB
Development of the Korea-Polyenvironmental Risk Score for Psychosis
Objective: Comprehensive understanding of polyenvironmental risk factors for the development of psychosis is important. Based on a review of related evidence, we developed the Korea Polyenvironmental Risk Score (K-PERS) for psychosis. We investigated whether the K-PERS can differentiate patients with schizophrenia spectrum disorders (SSDs) from healthy controls (HCs). Methods: We reviewed existing tools for measuring polyenvironmental risk factors for psychosis, including the Maudsley Environmental Risk Score (ERS), polyenviromic risk score (PERS), and Psychosis Polyrisk Score (PPS). Using odds ratios and relative risks for Western studies and the "population proportion" (PP) of risk factors for Korean data, we developed the K-PERS, and compared the scores thereon between patients with SSDs and HCs. In addition, correlation was performed between the K-PERS and Positive and Negative Syndrome Scale (PANSS). Results: We first constructed the "K-PERS-I," comprising five factors based on the PPS, and then the "K-PERS-II" comprising six factors based on the ERS. The instruments accurately predicted participants' status (case vs. control). In addition, the K-PERS-I and -II scores exhibited significant negative correlations with the negative symptom factor score of the PANSS. Conclusion: The K-PERS is the first comprehensive tool developed based on PP data obtained from Korean studies that measures polyenvironmental risk factors for psychosis. Using pilot data, the K-PERS predicted patient status (SSD vs. HC). Further research is warranted to examine the relationship of K-PERS scores with clinical outcomes of psychosis and schizophrenia
BOAO Photometric Survey of Galactic Open Clusters. III. Czernik 24 and Czernik 27
We present BV CCD photometry for the open clusters Czernik 24 and Czernik 27.
These clusters have never been studied before, and we provide, for the first
time, the cluster parameters; reddening, distance, metallicity and age. Czernik
24 is an old open cluster with age 1.8 +/- 0.2 Gyr, metallicity [Fe/H]=-0.41
+/- 0.15 dex, distance modulus (m-M)_0 = 13.1 +/- 0.3 mag (d=4.1 +/- 0.5 kpc),
and reddening E(B-V) = 0.54 +/- 0.12 mag. The parameters for Czernik 27 are
estimated to be age = 0.63 +/- 0.07 Gyr, [Fe/H]= -0.02 +/- 0.10 dex, (m-M)_0 =
13.8 +/- 0.2 mag (d=5.8 +/- 0.5 kpc), and E(B-V) = 0.15 +/- 0.05 mag. The
metallicity and distance values for Czernik 24 are consistent with the relation
between the metallicity and the Galactocentric distance of other old open
clusters. We find the metallicity gradient of 51 old open clusters including
Czernik 24 to be Delta [Fe/H]/Delta R_gc= -0.064 +/- 0.009 dex/kpc.Comment: Accepted by the Journal of the Korean Astronomical Society, 2005
December issu
Prediction of Specific Anxiety Symptoms and Virtual Reality Sickness Using In Situ Autonomic Physiological Signals During Virtual Reality Treatment in Patients With Social Anxiety Disorder: Mixed Methods Study
Background: Social anxiety disorder (SAD) is the fear of social situations where a person anticipates being evaluated negatively. Changes in autonomic response patterns are related to the expression of anxiety symptoms. Virtual reality (VR) sickness can inhibit VR experiences. Objective: This study aimed to predict the severity of specific anxiety symptoms and VR sickness in patients with SAD, using machine learning based on in situ autonomic physiological signals (heart rate and galvanic skin response) during VR treatment sessions. Methods: This study included 32 participants with SAD taking part in 6 VR sessions. During each VR session, the heart rate and galvanic skin response of all participants were measured in real time. We assessed specific anxiety symptoms using the Internalized Shame Scale (ISS) and the Post-Event Rumination Scale (PERS), and VR sickness using the Simulator Sickness Questionnaire (SSQ) during 4 VR sessions (#1, #2, #4, and #6). Logistic regression, random forest, and naive Bayes classification classified and predicted the severity groups in the ISS, PERS, and SSQ subdomains based on in situ autonomic physiological signal data. Results: The severity of SAD was predicted with 3 machine learning models. According to the F1 score, the highest prediction performance among each domain for severity was determined. The F1 score of the ISS mistake anxiety subdomain was 0.8421 using the logistic regression model, that of the PERS positive subdomain was 0.7619 using the naive Bayes classifier, and that of total VR sickness was 0.7059 using the random forest model. Conclusions: This study could predict specific anxiety symptoms and VR sickness during VR intervention by autonomic physiological signals alone in real time. Machine learning models can predict the severe and nonsevere psychological states of individuals based on in situ physiological signal data during VR interventions for real-time interactive services. These models can support the diagnosis of specific anxiety symptoms and VR sickness with minimal participant bias
A Case of Intra- and Extra-Mural Hematomas During Recanalization for Chronic Total Occlusion
An intramural hematoma is an accumulation of blood between the internal and external elastic membranes within the medial space, whereas an extramural hematoma is a dilution and/or dissemination of blood throughout the adventitia. Intra- and extra-hematomas are observed by intravascular ultrasound during percutaneous coronary intervention (PCI). The patient described herein presented with angina pectoris. Her coronary angiogram showed diffuse narrowing of the mid-left anterior descending artery and total occlusion of the distal right coronary artery (RCA). Intra- and extra-mural hematomas developed during PCI of the RCA; however, the lesions were covered successfully using long drug-eluting stents
Epidemiology of Traumatic Head Injury in Korean Children
The aim of this study was to elucidate the epidemiology of traumatic head injury (THI) among Korean children. A prospective, in-depth trauma survey was conducted in five teaching hospitals. Data from all of the children who attended the emergency department (ED) were analyzed. From June 2008 to May 2009, 2,856 children with THI visited the 5 EDs. The average age of the subjects was 5.6 (SD ± 4.9) yr old, and 1,585 (55.5%) were 0-4 yr old. The male-to-female ratio was 2.3 to 1 (1,979 vs 877). Consciousness levels of the subjects were classified according to the Glasgow Coma Scale (GCS), and 99.1%, 0.6%, and 0.4% were determined as mild, moderate, or severe injury, respectively, according to the GCS categorization. Most injuries occurred at home (51.3%), and the most common mechanism of injury was collision (43.2%). With regard to outcome, 2,682 (93.9%) patients were sent home, and 35 (1.2%) were transferred to another hospital. A total of 133 (4.7%) patients were hospitalized, and 38 (1.3%) underwent surgery. The incidence and characteristics of pediatric THI in Korea are affected by sex, location and injury mechanism
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