Improving the performance of temperature index snowmelt model of SWAT by using MODIS land surface temperature data.

Simulation results of the widely used temperature index snowmelt model are greatly influenced by input air temperature data. Spatially sparse air temperature data remain the main factor inducing uncertainties and errors in that model, which limits its applications. Thus, to solve this problem, we created new air temperature data using linear regression relationships that can be formulated based on MODIS land surface temperature data. The Soil Water Assessment Tool model, which includes an improved temperature index snowmelt module, was chosen to test the newly created data. By evaluating simulation performance for daily snowmelt in three test basins of the Amur River, performance of the newly created data was assessed. The coefficient of determination (R (2)) and Nash-Sutcliffe efficiency (NSE) were used for evaluation. The results indicate that MODIS land surface temperature data can be used as a new source for air temperature data creation. This will improve snow simulation using the temperature index model in an area with sparse air temperature observations.

Distribution of dissolved and particulate radiocesium concentrations along rivers and the relations between radiocesium concentration and deposition after the nuclear power plant accident in Fukushima.

This study involved measurement of concentrations of dissolved and particulate radiocesium ((134)Cs and (137)Cs) in river water, and determination of the quantitative relations between the amount of deposited (137)Cs and (137)Cs concentrations in river waters after the Fukushima Daiichi nuclear power plant accident. First, the current concentrations of dissolved and particulate (134)Cs·(137)Cs were determined in a river watershed from 20 sampling locations in four contaminated rivers (Abukuma, Kuchibuto, Shakado, and Ota). Distribution characteristics of different (137)Cs forms varied with rivers. Moreover, a higher dissolved (137)Cs concentration was observed at the sampling location where the (137)Cs deposition occurred much more heavily. In contrast, particulate (137)Cs concentration along the river was quite irregular, because fluctuations in suspended solids concentrations occur easily from disturbance and heavy precipitation. A similar tendency with dissolved (137)Cs distribution was observed for the (137)Cs concentration per unit weight of suspended solids. Regression analysis between deposited (137)Cs and dissolved/particulate (137)Cs concentrations was performed for the four rivers. The results showed a strong correlation between deposited (137)Cs and dissolved (137)Cs, and a relatively weak correlation between deposited (137)Cs and particulate (137)Cs concentration for each river. However, if the particulate (137)Cs concentration was converted to (137)Cs concentration per unit weight of suspended solid, the values showed a strong correlation with deposited (137)Cs.

Magnetisation transfer MR imaging of the kidney: evaluation at 3.0 T in association with renal function.

OBJECTIVE: To evaluate the feasibility of using magnetisation transfer (MT) MRI of the kidney at 3.0 T to assess renal function. METHODS: Forty-four patients who underwent abdominal MRI on a 3.0-T system including gradient-echo (GRE) sequences with and without MT pulse were included. In each patient, MT ratio (MTR) of the renal cortex and medulla was measured by using regions of interest (ROIs) placed on the MTR map image. RESULTS: Regression analysis showed good correlation between estimated glomerular filtration rate (eGFR) and MTR of the renal cortex (r = -0.645, P < 0.0001). Among 44 patients, 22 were categorised as the normal renal function group and 22 were classified as the decreased eGFR group. The mean MTR of the renal cortex in patients with decreased eGFR (mean MTR, 30.7 ± 3.2 %) was significantly higher (P < 0.0001) than that in patients with normal renal function (mean MTR, 25.3 ± 2.2 %), although the mean MTRs of the renal medulla in the two groups were not significantly different. CONCLUSION: There was good correlation between eGFR and MTR of the renal cortex derived from MT MRI at 3.0 T. This technique may have the potential to evaluate the degree of renal function non-invasively in patients with renal impairment. KEY POINTS: • Magnetisation transfer techniques can provide new information about renal disease. • MTR values of the renal cortex correlate well with estimated glomerular filtration. • Higher MTR of the renal cortex exists in patients with renal dysfunction. • MT MRI at 3.0 T may be useful for evaluating renal function.

Surface scattering in implanted hydrophobic intraocular lenses.

PURPOSE: To describe surface scattering, a new phenomenon in polyacrylic intraocular lenses (IOLs), and discuss the possible cause of this finding. SETTING: Showa University, Fujigaoka Hospital, Yokohama, Kanagawa, Japan. METHODS: This observational case series involved 40 patients who received the AcrySof(R) IOL (Alcon Laboratories, Inc.) as part of a clinical trial in 1991. Four patients (5 eyes) were evaluated. Thirty-three patients had the same surgery in 1999, and the findings in these patients were compared with those in the earlier patients. Lens surface scattering was evaluated by area densitometry using Scheimpflug photography. No statistical analysis was done because of the small sample size. RESULTS: The 5 IOLs implanted in 1991 showed various degrees of surface scattering. The degree of scattering was greater than that in the 1999 group. There was no degradation in visual performance and no manifestation of intraocular inflammation or other adverse effect from the IOLs in either group. Attempts to remove foreign material on the IOL using the neodymium:YAG (Nd:YAG) laser were unsuccessful. CONCLUSIONS: The surface scattering did not appear to be due to deposition of foreign material on the IOL surface. Densitometry and the results of Nd:YAG laser treatment suggest that the changes occurred in the near-surface layer. Phase separation of water near the IOL surface in the inherently hydrophobic material may explain the phenomenon. Newer AcrySof IOLs appear to have less surface scattering.

Three-year prospective randomized study of incidence of posterior capsule opacification in eyes treated with topical diclofenac and betamethasone.

PURPOSE: To investigate the incidence of posterior capsule opacification (PCO) in eyes treated with diclofenac sodium (DFNa) and betamethasone phosphate (BMS) ophthalmic solutions. METHODS: A total of 200 eyes with silicone intraocular lens implantation were treated with topical agents for 3 months postoperatively. Twenty-six cases of the DFNa group and 34 of the BMS group met the criteria, and the severity of PCO was evaluated after 3 years. RESULTS: The results of axial densitometry by Scheimpflug photography were 27.8 computer-compatible tapes (CCT) in the DFNa-treated group and 32.6 CCT in the BMS-treated group (p = 0.1539). Posterior capsulotomy was performed in 11.5% of the DFNa group and 17.6% of the BMS group (p = 0.8375). The photographic grading of PCO showed no difference. CONCLUSION: The incidence of PCO in eyes treated with DFNa appears to be equal to that after BMS treatment.