No abstract

The decomposition rates of organic nitrogen and organic phosphorus in lakes and rivers can be important parameters in water quality model calibrations. Commonly, decomposition rate coefficients are calibrated by observing the changes in each component in the field survey. However, in natural field conditions, production and decomposition occur at the same time, and the calibrations may result in uncertainties. In this study, water samples collected from six major rivers in Korea were incubated for 20 days in a dark incubator and the decomposition rates of POP, DOP, LDOP, PON, DON, LPON, LDON, ammonia, and nitrite were determined. By excluding the interference of photosynthesis, animal grazing, and excretion, the decomposition rate coefficients were determined with less uncertainty than in natural conditions. The decomposition data were fit to first-order models of several decomposition pathways, including POP ! DIP,The decomposition rates of dissolved forms were five-seven times higher than particulate forms. And the rates of organic P (0.149 day �1 for LPOP and 0.718 day �1 for LDOP) were 1.6 times higher than those of organic N (0.093 day �1 for LPON and 0.472 day �1 for LDON). Traditionally, the decomposition rates of organic phosphorus and organic nitrogen are not discriminated; the same rate is applied to organic carbon, nitrogen, and phosphorus. The result of this study shows that organic phosphorus and nitrogen should be given different decomposition rates for more accurate models. The rate coefficients measured in this study will provide a guide to the selection of model parameters for water quality modeling.

The APEC Climate Center (APCC) produces climate prediction information utilizing a multi-climate model ensemble (MME) technique. In this study, four different downscaling methods, in accordance with the degree of utilizing the seasonal climate prediction information, were developed in order to improve predictability and to refine the spatial scale. These methods include: (1) the Simple Bias Correction (SBC) method, which directly uses APCC's dynamic prediction data with a 3 to 6 month lead time; (2) the Moving Window Regression (MWR) method, which indirectly utilizes dynamic prediction data; (3) the Climate Index Regression (CIR) method, which predominantly uses observation-based climate indices; and (4) the Integrated Time Regression (ITR) method, which uses predictors selected from both CIR and MWR. Then, a sampling-based temporal downscaling was conducted using the Mahalanobis distance method in order to create daily weather inputs to the Soil and Water Assessment Tool (SWAT) model. Long-term predictability of water quality within the Wecheon watershed of the Nakdong River Basin was evaluated. According to the Korean Ministry of Environment's Provisions of Water Quality Prediction and Response Measures, modeling-based predictability was evaluated by using 3month lead prediction data issued in February, May, August, and November as model input of SWAT. Finally, an integrated approach, which takes into account various climate information and downscaling methods for water quality prediction, was presented. This integrated approach can be used to prevent potential problems caused by extreme climate in advance.

No abstract

ObjectiveThe aim of our study is to compare the overall survival (OS), progression-free survival (PFS), and treatment-related morbidities between primary concurrent chemoradiation therapy (CCRT) vs. radical hysterectomy (RH) with or without tailored adjuvant therapy in patients with stages IB2 and IIA cervical cancer.MethodsThis was a retrospective study of 113 patients with IB2 or IIA cervical cancer treated with either primary CCRT (n=49) or RH (n=64) with or without tailored adjuvant therapy between 2002 and 2011 at Keimyung University Dongsan Medical Center. Patients in RH group was divided into those undergoing surgery alone (n=26) and those undergoing surgery with adjuvant therapy (n=38).ResultsThe median follow up period was 66 months. The 5-year OS by treatment modality was 88.7% for the 64 patients in the RH group and 72.8% for 49 patients in the CCRT group (P=0.044). The 5-year PFS was 82.3% and 65.6% after RH group and CCRT group (P=0.048), respectively. Grade 3–4 complication was less frequent after RH alone (7.7%) than RH with adjuvant therapy (34.2%) or CCRT group (28.6%) (P=0.047).ConclusionThe RH group seems to be superior to the CCRT group in oncologic outcomes. However, considering the selection bias including tumor size, lymph node meta, and parametrial invasion in pretreatment magnetic resonance imaging, both treatment modalities are reasonable and feasible in cervical cancer IB2 and IIA. It is important to choose the appropriate treatment modality considering the age and general condition of the patient. Randomized controlled study is needed to confirm the result of our study and determine the optimal treatment.