175 research outputs found
Optimization of sediment rating curve coefficients using evolutionary algorithms and unsupervised artificial neural network
Sediment rating curve (SRC) is a conventional and a common regression model in estimating
suspended sediment load (SSL) of flow discharge. However, in most cases the data log-transformation
in SRC models causing a bias which underestimates SSL prediction. In this study, using the daily stream
flow and suspended sediment load data from Shalman hydrometric station on Shalmanroud River,
Guilan Province, Iran, SRC equation was derived, and then, using evolutionary algorithms (genetic
algorithm and particle swarm optimization algorithm) it was calibrated again. Worth mentioning,
before model calibration, to increase the generalization power of the models, using self-organizing map
(an unsupervised artificial neural network for data clustering), the data were clustered and then by
data sampling, they were classified into two homogeneous groups (calibration and test data set). The
results showed that evolutionary algorithms are appropriate methods for optimizing coefficients of
SRC model and their results are much more favorable than those of the conventional SRC models or
SRC models corrected by correction factors. So that, the sediment rating curve models calibrated with
evolutionary algorithms, by reducing the RMSE of the test data set of 5754.02 ton day-1
(in the initial
SRC model) to 1681.21 ton day-1
(in the calibrated models by evolutionary algorithms) increased the
accuracy of suspended sediment load estimation at a rate of 4072.81 ton day-1
. In total, using
evolutionary algorithms in calibrating SRC models prevents data log-transformation and use of
correction factors along with increasing in the accuracy of molding results
Investigation of soil physico-chemical properties in playa wetlands (Case study: Daryacheh-Namak
Abstract Soil, is a reclamable and sustainable source. it is the basis of survival and it’s implication, should be performed on the basis of productivity identification according to scientific and technical rules, we can protect this valuable source, and increase it’s productivity and usage. Nowdays, saline soils cover nearly 14.6% of the country area. Study areas (Kashan’ playa) have saline and alkali soils. Identification of these soils and their’s reclamation and implementation for different usage, is very important, especially, they have abundant water resources. They have important influence on establishment and development of plants. Therefore, we started qualitative and quantitative pedological research. First, we prepared cover map as georeference with Ilwis 3.3 software. We overlaied cover map and georeference geological map. We determined 12 working units, and then we took samples from units. Physico-chemical factores such as EC, Gypsum%, soluble cations and anions, organic matter, CaCO3 % and etc, determined from the depths of 0-10, 20-40, 40-80 of plant types(working units, QM, QC) in February and july. Result shows, Na, Mg, SO4, K, pH, Cl, CO3, HCO3, CaCO3, SAR, CEC rates decreased and Gypsum and Ca% rates increased, from the Lake to uplans. Also, the soil’s texture was changed from clay sandy loam to sandy loam. At last, was drew Soil’s salinity map according to the soil taxonomy, it is in entisol order, aquent suborder, endo aquent greatgroup and typic endoaquent subgroup. According to the results, the soil isn’t suitable for dry farming and aquaculture (very bad class (class V)). Study area, covered by halophyte plants and it will be appropriate to develop and improve with other halophytes. It should be protected from animals. Especially camels that conserve soil structure and poor plant cover
Pareto Optimization of a Five-Degree of Freedom Vehicle Vibration Model Using a MultiObjective Uniform-Diversity Genetic Algorithm (MUGA), Engineering
a b s t r a c t In this paper, a new multi-objective uniform-diversity genetic algorithm (MUGA) with a diversity preserving mechanism called the e-elimination algorithm is used for Pareto optimization of a fivedegree of freedom vehicle vibration model considering the five conflicting functions simultaneously. The important conflicting objective functions that have been considered in this work are, namely, seat acceleration, forward tire velocity, rear tire velocity, relative displacement between sprung mass and forward tire and relative displacement between sprung mass and rear tire. Further, different pairs of these objective functions have also been selected for 2-objective optimization processes. The comparison of the obtained results with those in the literature demonstrates the superiority of the results of this work. It is shown that the results of 5-objective optimization include those of 2-objective optimization and, therefore, provide more choices for optimal design of a vehicle vibration model
Investigation of pedological criterion on land degradation in quaternary rock units (case study: Rude-Shoor watershed area)
To investigate pedological criterion on land degradation in Quaternary rock units, at first, a part of the shoor watershed area was selected. After distinguishing target area, slope classes, land use and geology maps were created, then map of units were founded by overlaying and crossing these maps. In this research three indices of erodibility, salinity and permeability of soils were considered that finally each of them was shown in the shape of classified map. Then by overlaying and crossing of these maps, a new map was created that is an expression of research area zonation from the viewpoint of indices that formerly, were explained. As determining and distinguishing of desertification intensity of potential of created units from crossing of indices was not possible with using of pure mathematical or statistical relations, so were exploited principles and concepts of fuzzy logic and statistics to achieve to main result. We used functions of fuzzy algebraic sum, fuzzy algebraic product and fuzzy gamma after determining weight or value of fuzzy gamma after determining weight or value of factors. Obtained results from a comparison of gained maps from different operators with an evidence map as control area including maximum of desertification intensity, were measured in research area, to prove fuzzy function usefulness for zoning of desertification intensity or potential in research area and similar area with function of 0.8 from fuzzy gamma model (gamma = 0.8 ). Finally by overlaying the desertification potential zonation map with geological map, kinds of soil zones were characterized on the base of their desertification effect. This research determined three classes of desertification qualitative potential (very high 23/08%, high 56/88% and moderate 20/04%)
Bisphenol A enhances adipogenic signaling pathways in human mesenchymal stem cells
Background: The endocrine disruptor Bisphenol-A (BPA), has been involved in dysregulating adipose tissue development and increasing the risk of obesity. The objective of this experiment was to investigate whether treatment of human mesenchymal stem cells with BPA could modulate adipogenesis and adipocyte differentiation. Methods: In this experimental study, the human adipose-derived mesenchymal stem cells (hASCs) were cultured for 2 weeks with continuous exposure to 10- 10 M or 10- 8 M concentrations of BPA. The extent of triglyceride accumulation was visualized by Oil Red O staining. To evaluate BPA effect on the expression levels of key adipogenic trascripotion factors and proteins, we used Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and ELISA. Results: The results presented a dose-dependent triglyceride accumulation in treated cells with BPA. Additionally, we observed that BPA induced transcription of the Peroxisome proliferator-activated receptor-gamma (PPARγ), CCAAT-enhancer-binding protein-alpha (C/EBPα), CCAAT-enhancer-binding protein-beta (C/EBPβ), sterol regulatory element-binding protein-1c (SREBP1c), Fatty acid synthase (FASN), and lipoprotein lipase (LPL); BPA suppressed the expression of Fatty acid binding protein-4 (FABP4) and Estrogen receptor-beta (ERβ). Conclusions: Our findings supported the hypothesis that BPA enhances adipogenic differentiation thereby may play a role in development of obesity and dysregulation of metabolic homoeostasis. © 2020 The Author(s)
1,25-Dihydroxyvitamin D3 modulates adipogenesis of human adipose-derived mesenchymal stem cells dose-dependently
Purpose: 1,25-dihydroxyvitamin D3 may regulate adipogenesis in adipocytes in-vitro, but little is known about possible molecular mechanisms related to the inhibitory effect of 1,25-dihydroxyvitamin D3 on adipogenesis in humans� adipose tissue. Methodology: In this study, human adipose-derived mesenchymal stem cells (hASCs) were cultured for 14 days in adipogenic differentiation media containing concentrations of 1,25-dihydroxyvitamin D3 (10�10�10�8 M). The extent of adipogenic differentiation in ASCs was assessed by Oil Red O staining and quantitative polymerase chain reaction (PCR) to determine expression levels of key adipogenic markers. Results: Our results showed that vitamin D receptor (VDR), as a mediator of most actions of 1,25-dihydroxyvitamin D3, glucose trasporter-4 (GLUT4),and fatty acid binding protein-4 (FABP4) was expressed in vitamin D-treated hASCs. However, the protein level of these markers was lower than the control group. Treatment of human preadipocytes with 1,25-dihydroxyvitamin D3 significantly altered expression of adipogenic markers and triglyceride accumulation in a dose-dependent manner. 1,25-dihydroxyvitamin D3 at concentration of 10�8 M enhanced expression of sterol regulatory element-binding protein-1c (SREBP1c), CCAAT-enhancer-binding protein-β (C/EBPβ), a mitotic clonal expansion, peroxisome proliferator-activated receptor-gamma (PPARγ), fatty acid synthase (FASN), a marker of de novo lipogenesis,and lipoprotein lipase (LPL). Conclusion: Our findings revealed that 1,25-dihydroxyvitamin D3 may provoke adipocyte development in critical periods of adipogenesis at concentration of 10�8 M, thereby leading to a greater risk of obesity in adulthood and an augmented risk of obesity-related diseases including diabetes, cardiovascular diseases, and some cancers. © 2021, The Author(s)
Effects of various super absorbent concentrations on runoff volume in slopes and various intensity of simulated rainfall in Shahrekord plain
Abstract In order to study the effect of super absorbent on runoff volume in slopes and various intensity of rainfall research was accomplish according to split – factorial blocks method with main treatment and two accessory treatments in three replicate . the main treatment consist of three dominant slopes (10 , 20 , 30 percent ) and accessory treatments consist of five levels of substance super absorbent ( instance , 20 , 40 , 60 , 80 kg/ha ) and three levels of various rainfall intensity (25, 30,40 mm/hr). the rain simulator set was used and the rainfall duration intervals was 30 minutes. To establish hydraulic pressure complementary water volume added to reservoir tank in each 5 minutes. Then runoff was gathered to measure output runoff volume. Finally statistical analysis was done on the collected data. Results shows that substance super absorbent treatments of various rainfall intensity in comparison with control plate has significant effect in decrease of output runoff volume to 5 level percent. Keywords: Soil erosion;, Super absorbent; Rain simulation; Volume runoff; Slop
Molecular mechanisms of vitamin D plus Bisphenol A effects on adipogenesis in human adipose-derived mesenchymal stem cells
Background: Obesity is considered a major health concern and mounting evidence suggests that the exposure to environmental endocrine disruptors, including Bisphenol-A (BPA), may enhance the risk to develop the disease. Moreover, growing documents propose that the vitamin D may contribute to adipogenic signaling and lipid accumulation during adipocyte differentiation. We focused on the molecular mechanism of vitamin D and BPA in human adipose-derived mesenchymal stem cells (hADMSCs) which vitamin D and BPA may influence adipose tissue development and function. Methods: Human adipose-derived mesenchymal stem cells were cultured for 14 days in lipogenic differentiation media containing continuous concentrations of vitamin D plus BPA (0.1 nM or 10 nM). The expression of adipogenic markers including the peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-enhancer-binding protein α (C/EBP α) CCAAT-enhancer-binding protein β (C/EBP β), fatty acid synthase (FASN), lipoprotein lipase (LPL), sterol regulatory element-binding protein-1c (SREBP1c), insulin-induced gene-2 (INSIG2), vitamin D receptor (VDR), estrogen receptor-beta (ER-β), fatty acid-binding protein-4 (FABP4), and glucose transporter-4 (GLUT4) was measured using Quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA). Lipid accumulation was visualized with staining with Oil Red O. Results: In the morphological assessment of mesenchymal stem cells treated with a concentration of 10 nM vitamin D plus BPA, more lipid accumulations were observed in comparison with the group with 0.1 nM concentration. Treatment of hADMSCs with vitamin D plus BPA (0.1 nM) significantly inhibited the induction of PPARγ, C/EBP β, C/EBP α, and FASN related to adipocyte differentiation and development. However, the exposure of cells to the concentration of 10 nM vitamin D plus BPA induced the expression of these genes associated to the adipogenesis. The remarkable increase in the level of SREBP1c was associated to the suppression of INSIG2 in treated preadipocytes with 10 nM vitamin D plus BPA. Our findings showed that the expression of VDR, ERβ, GLUT4, and FABP4 were upregulated through differentiation with the highest concentrations in 0.1 nM vitamin D plus BPA group for VDR, ERβ, and GLUT4. Conclusions: Vitamin D plus BPA at concentration of 10 nM boosted the adipogenesis during the critical stages of adipocytes development, whereas it seems to inhibit this process at concentration of 0.1 nM. © 2021, The Author(s)
Correction to: 1,25-Dihydroxyvitamin D3 modulates adipogenesis of human adipose-derived mesenchymal stem cells dose-dependently (Nutrition & Metabolism, (2021), 18, 1, (29), 10.1186/s12986-021-00561-4)
Following publication of the original article 1, the authors identified an error in the affiliation of Dr. Mehdi Hedayati. © 2021, The Author(s)
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