48 research outputs found

    Numerical modelling of the groundwater inflow to an advancing open pit mine: Kolahdarvazeh pit, Central Iran

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    The groundwater inflow into a mine during its life and after ceasing operations is one of the most important concerns of the mining industry. This paper presents a hydrogeological assessment of the Irankuh Zn-Pb mine at 20 km south of Esfahan and 1 km northeast of Abnil in west-Central Iran. During mine excavation, the upper impervious bed of a confined aquifer was broken and water at high-pressure flowed into an open pit mine associated with the Kolahdarvazeh deposit. The inflow rates were 6.7 and 1.4 m3/s at the maximum and minimum quantities, respectively. Permeability, storage coefficient, thickness and initial head of the fully saturated confined aquifer were 3.5 x 10−4 m/s, 0.2, 30 m and 60 m, respectively. The hydraulic heads as a function of time were monitored at four observation wells in the vicinity of the pit over 19 weeks and at an observation well near a test well over 21 h. In addition, by measuring the rate of pumping out from the pit sump, at a constant head (usually equal to height of the pit floor), the real inflow rates to the pit were monitored. The main innovations of this work were to make comparison between numerical modelling using a finite element software called SEEP/W and actual data related to inflow and extend the applicability of the numerical model. This model was further used to estimate the hydraulic heads at the observation wells around the pit over 19 weeks during mining operations. Data from a pump-out test and observation wells were used for model calibration and verification. In order to evaluate the model efficiency, the modelling results of inflow quantity and hydraulic heads were compared to those from analytical solutions, as well as the field data. The mean percent error in relation to field data for the inflow quantity was 0.108. It varied between 1.16 and 1.46 for hydraulic head predictions, which are much lower values than the mean percent errors resulted from the analytical solutions (from 1.8 to 5.3 for inflow and from 2.16 to 3.5 for hydraulic head predictions). The analytical solutions underestimated the inflow compared to the numerical model for the time period of 2-19 weeks. The results presented in this paper can be used for developing an effective dewatering program

    Implications on the Therapeutic Potential of Statins via Modulation of Autophagy

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    Statins, which are functionally known as 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) inhibitors, are lipid-lowering compounds widely prescribed in patients with cardiovascular diseases (CVD). Several biological and therapeutic functions have been attributed to statins, including neuroprotection, antioxidation, anti-inflammation, and anticancer effects. Pharmacological characteristics of statins have been attributed to their involvement in the modulation of several cellular signaling pathways. Over the past few years, the therapeutic role of statins has partially been attributed to the induction of autophagy, which is critical in maintaining cellular homeostasis and accounts for the removal of unfavorable cells or specific organelles within cells. Dysregulated mechanisms of the autophagy pathway have been attributed to the etiopathogenesis of various disorders, including neurodegenerative disorders, malignancies, infections, and even aging. Autophagy functions as a double-edged sword during tumor metastasis. On the one hand, it plays a role in inhibiting metastasis through restricting necrosis of tumor cells, suppressing the infiltration of the inflammatory cell to the tumor niche, and generating the release of mediators that induce potent immune responses against tumor cells. On the other hand, autophagy has also been associated with promoting tumor metastasis. Several anticancer medications which are aimed at inducing autophagy in the tumor cells are related to statins. This review article discusses the implications of statins in the induction of autophagy and, hence, the treatment of various disorders

    Evaluation of the association between KIR polymorphisms and systemic sclerosis : a meta-analysis

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    Background: The results of investigations on the association between killer cell immunoglobulin-like receptor (KIR) gene polymorphisms and the risk of systemic sclerosis (SSc) are inconsistent. To comprehensively evaluate the influence of KIR polymorphisms on the risk of SSc, this meta-analysis was performed. Methods: A systematic literature search was performed in electronic databases including Scopus and PubMed/ MEDLINE to find all available studies involving KIR gene family polymorphisms and SSc risk prior to July 2019. Pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were measured to detect associations between KIR gene family polymorphisms and SSc risk. Results: Five articles, comprising 571 patients and 796 healthy participants, evaluating the KIR gene family polymorphisms were included in the final meta-analysis according to the inclusion and exclusion criteria, and 16 KIR genes were assessed. None of the KIR genes were significantly associated with the risk of SSc. Conclusions: The current meta-analysis provides evidence that KIR genes might not be potential risk factors for SSc risk

    Graves' disease: introducing new genetic and epigenetic contributors

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    Autoimmune thyroid disease (AITD) accounts for 90% of all thyroid diseases and affects 2-5% of the population with remarkable familial clustering. Among AITDs, Graves' disease (GD) is a complex disease affecting thyroid function. Over the l ast two decades, casecontrol studies using cutting-edge gene sequencing techniques have detected various susceptible loci that may predispose individuals to GD. It has been presumed that all likely associated genes, variants, and polymorphisms might be responsible for 75-80% of the heritability of GD. As a result, there are implications concerning the potential contribution of environmental and epigenetic factors in the pathogenesis of GD, including its initiation, progression, and development. Numerous review studies have summarized the contribution of genetic factors in GD until now, but there are still some key questions and notions that have not been discussed concerning the interplay of genetic, epigenetic, and immunological factors. With this in mind, this review discusses some newly-identified loci and their potential roles in the pathogenicity of GD. This may lead to the identification of new, promising therapeutic targets. Here, we emphasized principles, listed all the reported disease-associated genes and polymorphisms, and also summarized the current understanding of the epigenetic basis of GD

    Genome-Wide Linkage Analysis of Hemodynamic Parameters Under Mental and Physical Stress in Extended Omani Arab Pedigrees:The Oman Family Study

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    Background: We performed a genome-wide scan in a homogeneous Arab population to identify genomic regions linked to blood pressure (BP) and its intermediate phenotypes during mental and physical stress tests. Methods: The Oman Family Study subjects (N = 1277) were recruited from five extended families of similar to 10 generations. Hemodynamic phenotypes were computed from beat-to-beat BP, electrocardiography and impedance cardiography. Multi-point linkage was performed for resting, mental (word conflict test, WCT) and cold pressor (CPT) stress and their reactivity scores (Delta), using variance components decomposition-based methods implemented in SOLAR. Results: Genome-wide scans for BP phenotypes identified quantitative trait loci (QTLs) with significant evidence of linkage on chromosomes 1 and 12 for WCT-linked cardiac output (LOD = 3.1) and systolic BP (LOD = 3.5). Evidence for suggestive linkage for WCT was found on chromosomes 3, 17 and 1 for heart rate (LOD = 2.3), DBP (LOD = 2.4) and left ventricular ejection time (LVET), respectively. For Delta WCT, suggestive QTLs were detected for CO on chr11 (LOD = 2.5), LVET on chr3 (LOD = 2.0) and EDI on chr9 (LOD = 2.1). For CPT, suggestive QTLs for HR and LVET shared the same region on chr22 (LOD 2.3 and 2.8, respectively) and on chr9 (LOD = 2.3) for SBP, chr7 (LOD = 2.4) for SV and chr19 (LOD = 2.6) for CO. For Delta CPT, CO and TPR top signals were detected on chr15 and 10 (LOD; 2.40, 2.08) respectively. Conclusion: Mental stress revealed the largest number of significant and suggestive loci for normal BP reported to date. The study of BP and its intermediate phenotypes under mental and physical stress may help reveal the genes involved in the pathogenesis of essential hypertension

    Competitive Interaction of Canola (Brassica napus) against Wild Mustard (Sinapis arvensis) using Replacement Series Method

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    Introduction: Increasing costs of herbicide inputs in intensive crop production systems and the incidence of herbicide resistance in weeds have renewed interest in exploiting crop competitiveness to reduced herbicide use. Two factors contribute to crop competitiveness against weeds: ability to withstand competition (AWC), or the ability to maintain high yields in the presence of weeds, and weed suppressive ability (WSA), the ability of the crop to reduce weed biomass and seed production. Wild mustard is a dominant weed in rapeseed fields of Iran bringing about major yield losses. A strongly persistent seedbank, competitive growth habit, and high fecundity all contribute to its weedy nature ensuring that it will be a continuing problem. In addition to yield losses in rapeseed, wild mustard can reduce crop quality even at its low densities. The main objective of the current paper is to investigate the competitive ability of the canola against wild mustard, and evaluating of empirical yield loss model in predicting the effect of different densities of wild mustard on canola yield. Materials and Methods: The experiment was performed in a randomized complete blocks design with four replications using replacement series in which wild mustard and rapeseed were planted in different ratios of 8:0, 6:2, 4:4, 2:6 and 0:8 plants per pot in 2014. Wild mustard and rapeseed seeds were planted in 35 cm diameter plastic pots filled with a sandy clay loam soil and 1 and 2 cm deep, respectively. Plants were harvested from the soil surface at maturity and were oven dried at 75 ͦ C for 48h, while total shoot biomass for each species being determined. Measurements included shoot and root dry weight, plant height, number of branches per plant, number of pod per plant, number seed per pod and plant seed yield in rapeseed. Relative Yield (RY), Relative Yield Total (RYT) and Relative Crowding Coefficient (RCC) were calculated. Relative yield (RY) is a measure of the relative competitive ability of the two species. RY was calculated using the equation: where Ymix and Ymon are yields in mixture and monoculture. Relative Yield Total (RYT) describes how the species pair utilizes resources. RYT was calculated using the equation: RYT= Relative Crowding Coefficient (RCC) is a measure of competitiveness between the two species. The RCC was calculated using the equation: RCC= Where YAmix and YBmix are average yield per plant of A and of B grown in mixture, respectively, YAmon and YBmon are average yield per plant of A and B grown in monoculture, respectively. Means were compared using Duncans, Multiple Range Test (P 0.05) (SAS, 2002). Results and Discussion: Results showed that the relative yield of rapeseed decreased in the density ratio of 25 and 50 percent compared to same densities of wild mustard. In comparison, rapeseed in a lower or even equal density was more sensitive to competition than wild mustard and hence it faced to sharp yield decrease. However, in the higher planting densities of 75 percent the relative yield of rapeseed increased and the value reached to 0.497. Regarding the higher values of wild mustard compared to rapeseed’s relative yield in higher density ratios of 50 and 75 percent it can be concluded that wild mustard possesses a higher competitive strength, as a consequence, was able to better use nutrition resources. Grain yield influenced markedly by density ratios (

    China's Political Economy and the Rapid Increase of its Foreign Aid to Africa

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    Along with the profound structural changes in China's political economy, its foreign assistance has rapidly increased to a wide range of countries, especially African societies, in the early years of the new century. This phenomenon, as well as many other phenomena associated with the "emergence of China," has sparked a lot of controversy about the motives and consequences of this transformation, which has not yet been addressed in our country. In this regard, the present paper, regardless of the implications of this evolution, examines its causes and context by referring to Beijing's motivations as donors and the needs of African societies as recipients in the context of the core question of the article. The hypothesis that the article examines by descriptive-analytic method is that the rapid increase of Chinese foreign aid to African countries in recent years is primarily due to the international requirements for responding to structural changes in China's domestic political economy and the alignment of the needs of African with Beijing foreign assistance. So, it can be predicted that the presence of China in the Africa will continue to increase in the coming years, and foreign aid will continue to be considered by Beijing officials as one of the main means for establishing this wider presence
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