Hydrological modeling in the Marmot creek basin

Two primary purposes of this research were to assess the hydrologic response and to detect the hydrologic similarity of a 9.5 km² needle-leaf forested watershed in the Canadian Prairie province of Alberta known the Marmot Creek basin. In order to achieve these two objectives, three hydrologic models and several analysis methods were applied in this study. -- Topographic index, In(α/tanβ), was calculated by different flow routing algorithms ( single flow and biflow direction algorithms) with 1- and 90-meter resolution digital elevation models (DEM) in this research. A series of maps and tabular outputs showed that in high resolution DEM, the distinction of the frequency distribution of In(α/tanβ) was pronounced between different algorithms. However, in low resolution DEM, the difference was not obvious. -- Evaporative resistances (stomatal and aerodynamic), which was used to calculate potential evapotranspiration (PET), was estimated by Canadian Land Surface Scheme CLASS). Aerodynamic resistance was also produced by the Monteith method (1965) under neutral conditions. The maximum stomatal resistance in the Marmot Creek basin could reach 2000 m s⁻¹ : however, the minimum value was only 0 s⁻¹. A series of comparisons showed that aerodynamic resistance computed by CLASS and Monteith method (1965) were fairly close. -- PET, as one of the input data sets to drive TOPMODEL in this research, was estimated by Penman-Monteith formulation. The peak of PET over the Marmot Creek basin occurred in July, and October had the lowest rate, which was equal to half the peak value in July. The effects of evaporative resistance on PET were also discussed. From the results, it could be concluded that compared to aerodynamic resistance, stomatal resistance had main control of PET. -- TOPMODEL, a topographically-based hydrologic model, was used to assess the hydrologic response in the Marmot Creek basin. This hydrologic model was combined with genetic algorithm (GA) to do calibration and, subsequently, validation with historical streamflow datasets retrieved from the Environment Canada hydrometric database. According to streamflow simulation with TOPMODEL, subsurface flow accounted for 84.9% of the total simulated streamflow during the calibration periods for the Marmot Creek basin. The simulations yielded a Nash-Sutcliffe efficiency of about 0.611, which was acceptable given the limitations of climate data. However, during the validation phase of the model assessment, there were some discrepancies between the simulated streamflow response and the observed values. Moreover, different In(α/tanβ) distributions were observed using different grid sizes in different flow direction algorithms, but these did not lead to significant departures in all the cases of the simulated streamflow. -- Four-meter resolution IKONOS images were used to perform land cover classification in the Marmot Creek basin through a Decision Tree classifier using Normalized Difference Vegetation index (NDVI) input. The variation of In(α/tanβ) between different land covers was investigated using one-way analysis of variance (ANOVA). The results of NOVA showed that no obvious relationship between In(α/tanβ) and the land cover classes could be determined

The impact of masticatory dysfunction caused by occlusal disharmony on cognitive function

As the world’s population ages, age-related cognitive decline and dementia are becoming important challenges for geriatric care. Despite the ongoing search for solutions to address cognitive decline, effective interventions have not yet been established. There is increasing evidence from clinical, epidemiological, and animal studies that masticatory dysfunction due to occlusal disharmony is a risk factor for cognitive decline and an increased incidence of dementia. The mechanisms may involve altered nutritional intake, decreased cerebral blood flow, chronic stress, and hippocampal morphological function. These findings suggest that maintaining and adequately restoring the entire masticatory system has a positive impact for the prevention of cognitive decline

Image_1_Untargeted metabolomics based on ultra-high performance liquid chromatography-mass spectrometry/MS reveals the lipid-lowering mechanism of taurine in hyperlipidemia mice.pdf

IntroductionTaurine has a prominent lipid-lowering effect on hyperlipidemia. However, a comprehensive analysis of the effects of taurine on endogenous metabolites in hyperlipidemia has not been documented. This study aimed to explore the impact of taurine on multiple metabolites associated with hyperlipidemia.MethodsThe hyperlipidemic mouse model was induced by high-fat diet (HFD). Taurine was administered via oral gavage at doses of 700  mg/kg/day for 14  weeks. Evaluation of body weight, serum lipid levels, and histopathology of the liver and adipose tissue was performed to confirm the lipid-lowering effect of taurine. Ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS)-based metabonomics analyses of serum, urine, feces, and liver, coupled with multivariate data analysis, were conducted to assess changes in the endogenous metabolites.Results and discussionBiochemical and histological examinations demonstrated that taurine administration prevented weight gain and dyslipidemia, and alleviated lipid deposition in the liver and adipose tissue in hyperlipidemic mice. A total of 76 differential metabolites were identified by UPLC-MS-based metabolomics approach, mainly involving BAs, GPs, SMs, DGs, TGs, PUFAs and amino acids. Taurine was found to partially prevent HFDinduced abnormalities in the aforementioned metabolites. Using KEGG database and MetaboAnalyst software, it was determined that taurine effectively alleviates metabolic abnormalities caused by HFD, including fatty acid metabolism, sphingolipid metabolism, glycerophospholipid metabolism, diacylglycerol metabolism, amino acid metabolism, bile acid and taurine metabolism, taurine and hypotaurine metabolism. Moreover, DGs, GPs and SMs, and taurine itself may serve as active metabolites in facilitating various anti-hyperlipidemia signal pathways associated with taurine. This study provides new evidence for taurine to prevent hyperlipidemia.</p