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Objective : Spondylitis is often chemotherapy resistant and requires long-term treatment. Without adequate chemotherapy, the outcome can be fatal or result in severe neurologic damage. Therefore, differentiating the etiology of spondylitis is very important, particularly in spontaneous cases. As the prevalence of tuberculosis in Korea has decreased in recent years, updated clinical research about spondylitis is warranted. Methods : From April 2010 to March 2016, data from spondylitis patients were collected retrospectively. In total, 69 patients (51 with pyogenic spondylitis and 18 with tuberculous spondylitis) were included. Clinical data, laboratory findings including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level, measurements of Cobb angles at the initial and final followup, and radiologic features on magnetic resonance imaging (MRI) scans were evaluated. To test differences between the pyogenic and tuberculous groups, numerical data were compared using the student's t-test and Mann-Whitney U test, and categorical data were compared using the chi-square test and Fisher's exact test. Results : The patients' mean age was 60.0 years. Male sex was slightly predominant (56.5%). There was no difference in mean age and sex between the two groups. The pyogenic group had a relatively higher proportion of immunocompromised patients. The peak CRP value was higher in the pyogenic group than in the tuberculous group (14.08 mg/dL and 8.50 mg/dL, respectively, p=0.009), whereas the ESR was not significantly different between the groups (81.5 mm/h and 75.6 mm/h, respectively, p=0.442). Radiologically, the presence of disc space sparing and vertebral body collapse differed between the groups. In the tuberculous group, the disc was more commonly preserved on contrast-enhanced MRI (50% and 23.5%, respectively, p=0.044), and vertebral body collapse was more common (66.6% and 15.7%, respectively, p<0.001). The mean length of hospitalization was longer in the pyogenic group (56.5 days and 41.2 days, respectively, p=0.001). Four mortality cases were observed only in the pyogenic group. The most commonly isolated microorganism in the pyogenic group was Staphylococcus aureus (S. aureus) (methicillin susceptible S. aureus and methicillin resistant S. aureus [MRSA] in 8 and 4 cases, respectively). Conclusion : The clinical and radiological manifestations of spontaneous spondylitis differ based on the causative organism. Pyogenic spondylitis patients tend to have a higher CRP level and a more severe clinical course, whereas tuberculous spondylitis patients present with destruction of the vertebral body with disc sparing more frequently. The presence of MRSA is increasing in community-acquired spondylitis cases. [ABSTRACT FROM AUTHOR]

Vegetation indices based on selected wavelength reflectance measurements are used to represent crop growth and physiological conditions. However, it has been determined that the anisotropic properties of the crop canopy surface can govern both the spectral reflectance and vegetation indices. In this study, in order to investigate how crop surface reflectance and vegetation indices varied according to the direction of the light source and sensor viewing, a hyper-spectrometer of visible to nearinfrared wavelengths mounted on a field goniometer was used at vegetative and reproductive growth stages in rice paddy. It was found that most of the wavelength reflectance measurements produced by the sparse vegetation cover fraction were not sensitive to solar-illumination and sensor-viewing angles. In addition, the reflectance of visible wavelengths was found to be less sensitive to the solar and sensor angles than the red-edge and near-infrared wavelengths. The lowest normalized difference vegetation index value in a day occurred at the nadir sensor-viewing angle before rice heading, but after heading, when ripened grains began to bow, the lowest value was recorded at the sensor zenith angle of 25°. Enhanced vegetation index measurements were found to be more sensitive to the direction of sensor viewing and less affected by sun glint than normalized difference vegetation index measurements. Additional field observation measurements should increase our level of understanding of how vegetation indices change on anisotropic crop surfaces. [ABSTRACT FROM AUTHOR]

Past studies have focused on the importance of hydrological variables in analyzing landslide initiation condition. Even though precipitation is the main driver of shallow landslides and debris flows, use of only rainfall-based parameters has shown some limitations. Soil moisture has been used widely to improve threshold detection capabilities. Since soil moisture directly reflects the wetness status of the ground, it can be used to identify pore pressure fluctuations more effectively. This study used rainfall and soil moisture simultaneously to capture landslide initiation conditions in detail. Results showed that continued rainfall on the day of landslide leaded to a sudden increase in soil moisture, and that soil moisture increments (ΔSM) were positive in 155 out of 170 landslide cases (91%). Two simple thresholds (daily precipitation over 40 mm, ΔSM over 0) and daily precipitation (P), Antecedent Precipitation Index (API), ΔSM-based three-dimensional threshold planes having 5%, 20% probability levels were applied and compared. With respect to false alarms (FA), P-based threshold was most effective among the single thresholds (FA ranging from 24 to 28 from September 2016 to December 2019 at five validation locations). Combining P- and ΔSM-based thresholds, FA reduced without compromising the detection accuracy (2 to 3 reduction in FA). Additionally combining threedimensional threshold with 20% probability level, FA reduced significantly (ranging from 12 to 16), at the cost of two detection failures. These findings demonstrate the need for combining precipitation and soil moisture to determine landslide thresholds. [ABSTRACT FROM AUTHOR]