3 results on '"Ung SA"'
Search Results
2. Causes of Decline in the Korean Fir Based on Spatial Distribution in the Mt. Halla Region in Korea: A Meta-Analysis
- Author
-
Ung San Ahn and Young Seok Yun
- Subjects
Abies koreana ,mortality rate ,forest decline ,terrain slope ,excess soil moisture ,Jeju ,Plant ecology ,QK900-989 - Abstract
Research Highlights: Technology advances have allowed for a new approach to research the decline of the Korean fir (Abies koreana E.H.Wilson). This study provides insights into the exact causes leading to this decline. Background and Objectives: Various factors could lead to the decline of fir trees around Mt. Halla, Korea, but these have not yet been verified. Here, the Korean fir across Mt. Halla were classified as dead or living and mapped using high-resolution orthorectified aerial images and three-dimensional (3D) stereoplotting. Materials and Methods: Aerial photographs were used to map spatial distribution and analyze the distribution patterns and mortality of the Korean fir. The electronic stereoplotting program (Geo3Di-PRO) enabled the creation of 3D images from aerial photographs. General, altitudinal, and topographical distribution was assessed. Results: Their accumulated percent mortality rate (APMR) showed positive correlations with altitude and tree density, a negative correlation with terrain slope, and no consistent correlation with solar radiation. The results indicate that increases in the density of Korean firs are related to decreased growth in areas at high altitude, on gentle slopes, and with high solar radiation. Consistent positive correlations between density and APMR indicate that fir mortality can be attributed to environmental deterioration and the establishment of unfavorable growth conditions. Areas with high APMR and density had gentle slopes, thus high soil moisture, or relatively high annual precipitation owing to high altitude. Conclusion: Fir mortality on Mt. Halla can be attributed to long-term persistently high rainfall and subsequent excess soil moisture.
- Published
- 2020
- Full Text
- View/download PDF
3. Epidemiological and virological characteristics of influenza viruses circulating in Cambodia from 2009 to 2011.
- Author
-
Horm SV, Mardy S, Rith S, Ly S, Heng S, Vong S, Kitsutani P, Ieng V, Tarantola A, Ly S, Sar B, Chea N, Sokhal B, Barr I, Kelso A, Horwood PF, Timmermans A, Hurt A, Lon C, Saunders D, Ung SA, Asgari N, Roces MC, Touch S, Komadina N, and Buchy P
- Subjects
- Animals, Antigens, Viral immunology, Cambodia epidemiology, Dogs, Drug Resistance, Viral, Hemagglutinin Glycoproteins, Influenza Virus genetics, Humans, Influenza A Virus, H1N1 Subtype genetics, Influenza A Virus, H1N1 Subtype isolation & purification, Influenza A Virus, H3N2 Subtype genetics, Influenza A Virus, H3N2 Subtype isolation & purification, Influenza B virus genetics, Influenza B virus isolation & purification, Influenza Vaccines immunology, Influenza, Human immunology, Madin Darby Canine Kidney Cells, Orthomyxoviridae immunology, Orthomyxoviridae isolation & purification, Phylogeny, Seasons, Influenza, Human epidemiology, Influenza, Human virology, Orthomyxoviridae physiology
- Abstract
Background: The Cambodian National Influenza Center (NIC) monitored and characterized circulating influenza strains from 2009 to 2011., Methodology/principal Findings: Sentinel and study sites collected nasopharyngeal specimens for diagnostic detection, virus isolation, antigenic characterization, sequencing and antiviral susceptibility analysis from patients who fulfilled case definitions for influenza-like illness, acute lower respiratory infections and event-based surveillance. Each year in Cambodia, influenza viruses were detected mainly from June to November, during the rainy season. Antigenic analysis show that A/H1N1pdm09 isolates belonged to the A/California/7/2009-like group. Circulating A/H3N2 strains were A/Brisbane/10/2007-like in 2009 before drifting to A/Perth/16/2009-like in 2010 and 2011. The Cambodian influenza B isolates from 2009 to 2011 all belonged to the B/Victoria lineage represented by the vaccine strains B/Brisbane/60/2008 and B/Malaysia/2506/2004. Sequences of the M2 gene obtained from representative 2009-2011 A/H3N2 and A/H1N1pdm09 strains all contained the S31N mutation associated with adamantanes resistance except for one A/H1N1pdm09 strain isolated in 2011 that lacked this mutation. No reduction in the susceptibility to neuraminidase inhibitors was observed among the influenza viruses circulating from 2009 to 2011. Phylogenetic analysis revealed that A/H3N2 strains clustered each year to a distinct group while most A/H1N1pdm09 isolates belonged to the S203T clade., Conclusions/significance: In Cambodia, from 2009 to 2011, influenza activity occurred throughout the year with peak seasonality during the rainy season from June to November. Seasonal influenza epidemics were due to multiple genetically distinct viruses, even though all of the isolates were antigenically similar to the reference vaccine strains. The drug susceptibility profile of Cambodian influenza strains revealed that neuraminidase inhibitors would be the drug of choice for influenza treatment and chemoprophylaxis in Cambodia, as adamantanes are no longer expected to be effective.
- Published
- 2014
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.