13 research outputs found

    Scrub Typhus Incidence Modeling with Meteorological Factors in South Korea

    Get PDF
    Since its recurrence in 1986, scrub typhus has been occurring annually and it is considered as one of the most prevalent diseases in Korea. Scrub typhus is a 3rd grade nationally notifiable disease that has greatly increased in Korea since 2000. The objective of this study is to construct a disease incidence model for prediction and quantification of the incidences of scrub typhus. Using data from 2001 to 2010, the incidence Artificial Neural Network (ANN) model, which considers the time-lag between scrub typhus and minimum temperature, precipitation and average wind speed based on the Granger causality and spectral analysis, is constructed and tested for 2011 to 2012. Results show reliable simulation of scrub typhus incidences with selected predictors, and indicate that the seasonality in meteorological data should be considered

    Bivariate Drought Analysis Using Streamflow Reconstruction with Tree Ring Indices in the Sacramento Basin, California, USA

    Get PDF
    Long-term streamflow data are vital for analysis of hydrological droughts. Using an artificial neural network (ANN) model and nine tree-ring indices, this study reconstructed the annual streamflow of the Sacramento River for the period from 1560 to 1871. Using the reconstructed streamflow data, the copula method was used for bivariate drought analysis, deriving a hydrological drought return period plot for the Sacramento River basin. Results showed strong correlation among drought characteristics, and the drought with a 20-year return period (17.2 million acre-feet (MAF) per year) in the Sacramento River basin could be considered a critical level of drought for water shortages

    Risk Factors for Antimicrobial Resistance Among the Escherichia coli Strains Isolated from Korean Patients with Acute Uncomplicated Cystitis: A Prospective and Nationwide Study

    Get PDF
    We investigated the risk factors for resistance to ciprofloxacin, cefazolin, ampicillin and co-trimoxazole in Escherichia coli isolates from urine of Korean female patients with acute uncomplicated cystitis (AUC). A total of 225 patients and their E. coli isolates were prospectively and nationwidely enrolled between May and October, 2006. All the antimicrobials did not show any differences according to the age group. A higher rate of ciprofloxacin resistance was observed in the south (OR: 3.04, 95% CI: 1.19-7.80 for Chungcheong-do & Jeolla-do; OR: 3.04, 95% CI: 1.22-7.58 for Gyeongsang-do) compared to Gyeonggi-do. Two recurrences of AUC in the past year was an important risk factor for antimicrobial resistance (ciprofloxacin; OR: 6.71, 95% CI: 1.86-24.11 and cefazolin; OR: 5.72, 95% CI: 1.20-27.25). However, the resistance to co-trimoxazole and ampicillin was not associated with any of the risk factors. This study also revealed the pattern of multi-drugs resistance in ciprofloxacin resistant E. coli strains. In conclusion, for Korean patients with two more recurrences of AUC in the past year, it is strongly recommended to perform an antimicrobial sensitivity test with a urine sample before empirical treatment

    Virulence Characteristics and Phylogenetic Background of Ciprofloxacin Resistant Escherichia coli in the Urine Samples from Korean Women with Acute Uncomplicated Cystitis

    Get PDF
    To clarify the characteristics of the virulence factors (VFs) of ciprofloxacin resistant Escherichia coli (CFRE) with acute uncomplicated cystitis (AUC), we determined the VFs and the phylogenetic background of all 54 CFRE strains and the 55 randomly selected ciprofloxacin sensitive E. coli strains (CFSE) from patients with AUC in 22 Korean hospitals. The prevalence of the VFs was as follows: fimA, papEF, papGIII, sfaI, dafaBC, cnf1, and hlyA were presented in 96%, 54%, 68%, 91%, 49%, 72%, and 29% of the samples, respectively. The expressions of papEF, cnf1, and hlyA were significantly more prevalent in the CFSE. Moreover, the expressions of cnf, and papEF significantly reduced the risk of ciprofloxacin resistance. The CFSE was also marginally associated with the group B2 (P=0.05). Although the presence of pyuria and a previous cystitis history were not related with the phylotyping and the expressions of VFs, group B2, and fimA and papEF were more expressed in the younger age patients (P<0.05). In conclusion, the CFRE exhibits a selective loss of VFs and the non-B2 phylotype in Korean AUC patients. The group B2 and the presence of fimA and papEF are associated with a younger age of AUC patients

    Electrically focus-tuneable ultrathin lens for high-resolution square subpixels.

    Get PDF
    Owing to the tremendous demands for high-resolution pixel-scale thin lenses in displays, we developed a graphene-based ultrathin square subpixel lens (USSL) capable of electrically tuneable focusing (ETF) with a performance competitive with that of a typical mechanical refractive lens. The fringe field due to a voltage bias in the graphene proves that our ETF-USSL can focus light onto a single point regardless of the wavelength of the visible light-by controlling the carriers at the Dirac point using radially patterned graphene layers, the focal length of the planar structure can be adjusted without changing the curvature or position of the lens. A high focusing efficiency of over 60% at a visible wavelength of 405 nm was achieved with a lens thickness of <13 nm, and a change of 19.42% in the focal length with a 9% increase in transmission was exhibited under a driving voltage. This design is first presented as an ETF-USSL that can be controlled in pixel units of flat panel displays for visible light. It can be easily applied as an add-on to high resolution, slim displays and provides a new direction for the application of multifunctional autostereoscopic displays

    Assessment of hydrological regimes for vegetation on riparian wetlands in Han River Basin, Korea

    No full text
    Hydrological regimes are regarded as one of the major determinants for wetland ecosystems, for they influence species composition, succession, productivity, and stability of vegetation communities. Since Korea launched the Four Major River Restoration Project in 2007, the water regimes of many of the riparian wetlands have changed, that is potentially affecting vegetation properties. For ecological conservation and management, it is important to connect hydrological characteristics and vegetation properties. The objective of this study is to investigate the influence of hydrological regimes on vegetation community, and develop a methodology that can connect them. Inundated exceedance probability (IEP) and its district concept are suggested to gain insights into hydrological regimes on the Binae wetland that is rehabilitated by the Restoration Project in 2012 and belong to the riparian zone. Results of this study indicate that the areas with P = 0.08 or lower IEPs should have the disturbance for vegetation communities, or could be changed to a hydrophilic vegetation in the study area, and it should be considered in the restoration and rehabilitation project to conserve legally protected or endangered vegetation

    Summer Season Water Temperature Modeling under the Climate Change: Case Study for Fourchue River, Quebec, Canada

    No full text
    It is accepted that human-induced climate change is unavoidable and it will have effects on physical, chemical, and biological properties of aquatic habitats. This will be especially important for cold water fishes such as trout. The objective of this study is to simulate water temperature for future periods under the climate change situations. Future water temperature in the Fourchue River (St-Alexandre-de-Kamouraska, QC, Canada) were simulated by the CEQUEAU hydrological and water temperature model, using meteorological inputs from the Coupled Model Intercomparison Project Phase 5 (CMIP5) Global Circulation Models (GCMs) with Representative Concentration Pathway (RCP) 2.6, 4.5 and 8.5 climate change scenarios. The result of the study indicated that water temperature in June will increase 0.2–0.7 °C and that in September, median water temperature could decrease by 0.2–1.1 °C. The rise in summer water temperature may be favorable to brook trout (Salvelinus fontinalis) growth, but several days over the Upper Incipient Lethal Temperature (UILT) are also likely to occur. Therefore, flow regulation procedures, including cold water releases from the Morin dam may have to be considered for the Fourchue River

    Sensitivity of Subjective Decisions in the GLUE Methodology for Quantifying the Uncertainty in the Flood Inundation Map for Seymour Reach in Indiana, USA

    No full text
    Generalized likelihood uncertainty estimation (GLUE) is one of the widely-used methods for quantifying uncertainty in flood inundation mapping. However, the subjective nature of its application involving the definition of the likelihood measure and the criteria for defining acceptable versus unacceptable models can lead to different results in quantifying uncertainty bounds. The objective of this paper is to perform a sensitivity analysis of the effect of the choice of likelihood measures and cut-off thresholds used in selecting behavioral and non-behavioral models in the GLUE methodology. By using a dataset for a reach along the White River in Seymour, Indiana, multiple prior distributions, likelihood measures and cut-off thresholds are used to investigate the role of subjective decisions in applying the GLUE methodology for uncertainty quantification related to topography, streamflow and Manning’s n. Results from this study show that a normal pdf produces a narrower uncertainty bound compared to a uniform pdf for an uncertain variable. Similarly, a likelihood measure based on water surface elevations is found to be less affected compared to other likelihood measures that are based on flood inundation area and width. Although the findings from this study are limited due to the use of a single test case, this paper provides a framework that can be utilized to gain a better understanding of the uncertainty while applying the GLUE methodology in flood inundation mapping
    corecore