ABSTRACT
This research evaluated climate change impacts on water resources using soil and water assessment tool (SWAT) models under representative concentration pathway scenarios (RCP 2.6, RCP 6, RCP 8.5). First, drought intensity was calculated using the standardized precipitation index (SPI) for the period 1987-2016. Then, the coefficients of precipitation as well as minimum and maximum temperature changes were simulated as SWAT model inputs. The results revealed that temperature will rise in future periods and the precipitation rate will be changed consequently. Then, changes in runoff during periods of 2011-2040, 2041-2070, and 2071-2100 were simulated by introducing downscaled results to SWAT model. The model was calibrated and validated by SWAT calibration and uncertainty procedures (SWAT-CUP). Nash-Sutcliffe (NS) coefficients (0.57 and 0.54) and R2 determination coefficients (0.65 and 0.63) were obtained for calibration and validation periods, respectively. The results showed that runoff will rise in fall and spring while it will drop in winter and summer throughout future periods under all three scenarios. Such seasonal shifts in runoff levels result from climate change consequences in the forms of temperature rise, snowmelt, altered precipitation pattern, etc. Future-period evapotranspiration will rise under all three scenarios with a maximum increase in the period 2070-2100 under RCP 8.5 scenario. Additionally, rainfed crop yields will decline without considerable changes in irrigated and horticultural crop yields.
Subject(s)
Agricultural Irrigation/methods , Climate Change , Crops, Agricultural/growth & development , Environmental Monitoring/methods , Water Resources/supply & distribution , Biomass , Iran , Models, Theoretical , Rivers/chemistry , Seasons , Soil/chemistry , TemperatureABSTRACT
Coexistence of pituitary adenoma (PA) and another type of brain tumor is a very rare clinical scenario. Even though such a presentation can be an incidental event but a thorough review of the literature will be made to elucidate the possible mechanisms and treatment options in similar cases. Two cases of concomitant sellar and suprasellar/diaphragmatic tumors are reported. A 37-year-old lady with prolactinoma and a suprasellar diaphragmatic meningioma and a 42-year-old acromegalic man with suprasellar/diaphragmatic meningioma and a PA. Both meningiomas were removed transcranially. The prolactinoma could be managed medically and the growth hormone secreting adenoma was removed trans-sphenoidally. The visual problems and hormonal imbalances of both patients improved postoperatively. The literature is reviewed on this topic and the possible pathogenesis and management protocol of similar lesions are discussed.
ABSTRACT
BACKGROUND AND OBJECTIVES: The purpose of this study is to evaluate the outcome and risks of radiosurgery for patients with arteriovenous malformations (AVM) of the brain all treated in a single center in the 3rd world with all its limitations. MATERIALS AND METHODS: We performed a retrospective analysis of 388 patients with AVM treated with radiosurgery during an 8-year period. Factors associated with increased chance of AVM obliteration or hemorrhages during the follow-up period were analyzed. RESULTS: Among 388 cases included in our series, 74 were Spetzler-Martin (SM) grade IV or V. Forty-four patients (11.3%) experienced post-radiosurgery hemorrhage in their follow-up period. The number of feeders (one/multiple) and deep location of the AVM did not alter the chance of bleeding (P < 0.05). Higher SM grading of the AVM was associated with increased chance of hemorrhage and decreased obliteration rate (P > 0.05) in the mid-term follow up. CONCLUSIONS: Our case series showed that radiosurgery can be considered a viable alternative in the treatment of even large AVMs which might not be considered good candidates for surgery or endovascular treatment. Further data including large size lesions are warranted to further support our findings.
ABSTRACT
BACKGROUND: The anti-inflammatory properties of magnesium sulfate have never been discussed in brain tumor surgeries. OBJECTIVES: This study is aimed to find anti-inflammatory aspects of high dose magnesium sulfate infusion during perioperative period of neurosurgical patients through checking the serial C-reactive protein (CRP) blood levels as a biomarker of inflammation. PATIENTS AND METHODS: Sixty patients who were candidate for elective craniotomy were enrolled randomly into two equal groups to receive either magnesium sulfate or normal saline during their perioperative period. Infusion of magnesium was performed three times during the study and a summation of 15 grams was administered: 1- two days before surgery, 2- one day before surgery, 3- from the beginning of surgery (five grams was infused within six hours in each session). Serum level of CRP was checked just before commencement of magnesium infusion and on the first and second day after surgery as primary outcome. Hemodynamic parameters, total propofol requirement and total blood loss were recorded as well. RESULTS: No significant difference was found between groups in terms of serum CRP levels. The mean arterial blood pressure, heart rate, blood loss and total anesthetic requirement were significantly lower in magnesium group in comparison to the control group. CONCLUSIONS: We did not find conclusive evidence for anti-inflammatory effects of magnesium in craniotomy for microsurgery of intracranial tumors using CRP level changes. However, high dose magnesium might be suggested as a safe anesthetic adjuvant in neurosurgery.
