115 research outputs found

    Assessing impacts of sea level rise on seawater intrusion in a coastal aquifer with sloped shoreline boundary

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.International Association for Hydro-environment Engineering and Research, Asia Pacific Division.This paper investigates the effect of gradual and instantaneous sea level rise (SLR) on the seawater intrusion (SWI) process in coastal aquifer systems with different levels of land-surface inundation. A set of hypothetical case studies with different shoreline slopes is used to conduct this numerical experiment. For the purpose of numerical modelling, a future rate of SLR from 2015 to 2100 is considered based on the moderate expectation of the Intergovernmental Panel on Climate Change (IPCC, 2001). The gradual SLR is implemented in two different stages. First, continuous and nonlinear rising of sea level is imposed starting from year 2015 up to the end of the century. After that the final value of sea level is maintained as constant in order to assess the response time spanning to a new steady state condition. The effects of pumping resulting in lowering of groundwater level are also considered together with the dynamic variation of sea level. The results show that the rate and the amount of SWI are considerably greater in aquifers with flat shoreline slopes compared with those with steep slopes. Moreover, a shorter period of time is required to reach a new steady state condition in systems with flatter slopes. The SWI process is followed by a significant depletion in quantity of freshwater resources at the end of the century. The situation is exacerbated with combined action of SLR and over-abstraction. Finally, by considering the effect of inundation of the shoreline due to gradual SLR, the sensitivity of the system to the main aquifer parameters including molecular diffusion of solute, dispersion, hydraulic conductivity and porosity is investigated

    Three dimensional simulation of seawater intrusion in a regional coastal aquifer in UAE

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    Published13th Computer Control for Water Industry Conference, CCWI 2015In this study the vulnerability of the Wadi Ham aquifer, located in the Fujairah Emirate of the UAE, to seawater intrusion (SWI) is assessed using a 3D finite element (FE) model. The numerical model is developed based on available hydrogeological data in real scale. By simulation of the aquifer for the next 10 years and by maintaining the current rates of pumping (in year 2015), the progress of seawater intrusion in year 2025 is followed by further depletion in freshwater storage of the Wadi Ham aquifer. In order to control this problem, the model is subjected to a management strategy involving surface recharge of the aquifer with treated wastewater

    Control of saltwater intrusion by aquifer storage and recovery

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    This is the final version of the article. Available from the publisher via the DOI in this record.Published Online 18th August 2016This paper presents the results obtained from the application of aquifer storage and recovery (ASR) technique to control seawater intrusion (SWI) in coastal aquifers. The study is based on the numerical modelling experiments performed using the SUTRA (Saturated–Unsaturated TRAnsport) finite-element code on the Wadi Ham aquifer in the UAE. A three-dimensional numerical model of this aquifer is developed and calibrated based on the available hydrogeological data in real scale. A significant amount of SWI has been calculated for the year 2015 due to the high rates of pumping from the available local well fields. To study the future responses of the aquifer to different control actions, the transient responses of SWI are simulated over a 10-year planning horizon. The proposed management measure (ASR) is implemented in repeated cycles of artificial recharge, storage and recovery using an additional set of wells defined in the model. The results show that ASR is a reliable method in controlling SWI in coastal aquifer systems besides its conventional role in subsurface water banking.The authors acknowledge their gratitude to the British Council, UK, for providing funding (project code: SH-04509) to support this research

    Cisplatin Induces Up-Regulation of KAI1, a Metastasis Suppressor Gene, in MCF-7 Breast Cancer Cell Line

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    Purpose: To investigate the effect of cisplatin on cell toxicity and metastasis through modulation of KAI1 gene expression.Methods: MCF-7cells were incubated with different concentrations of cisplatin for 24 h. RNA was extracted by trizol and cDNA synthesized. KAI1 and TBP were chosen as target and internal control genes, respectively. Specific primers were designed by primer express software, v.3.0. KAI1/TBP and gene expression ratio was calculated using the formula, 2 -ΔΔCt.Results: Cisplatin exerted a dose-dependent inhibitory effect on the viability of highly metastatic MCF-7 cells. KAI1/TBP gene expression ratios were 1.97 ± 0.19 (p < 0.05), 2.96 ± 0.55 (p < 0.05), 9.06 ± 0.27 (p < 0.001) and 12.38 ± 0.88 (p < 0.01) in 10, 20, 50 and 100 μM concentrations of cisplatin. Conclusion: These findings indicate that cisplatin can inhibit metastasis by up-regulating KAI1 gene in MCF-7cells.Keywords: Cisplatin; KAI1; Metastasis; Breast Cancer; Real-time PCR

    Nocardia transvalensis keratitis: an emerging pathology among travelers returning from Asia

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    <p>Abstract</p> <p>Background</p> <p>The incidence rate of <it>Nocardia </it>keratitis is increasing, with new species identified thanks to molecular methods. We herein report a case of <it>Nocardia transvalensis </it>keratitis, illustrating this emerging pathology among travellers returning from Asia.</p> <p>Case presentation</p> <p>A 23-year-old man presented with a 10-week history of ocular pain, redness, and blurred vision in his right eye following a projectile foreign body impacting the cornea while motor biking in Thaïland. At presentation, a central epithelial defect with a central whitish stromal infiltrate associated with pinhead satellite infiltrates was observed. Identification with 16S rRNA PCR sequencing and microbiological culture of corneal scraping and revealed <it>N. transvalensis </it>as the causative organism. Treatment was initiated with intensive topical amikacin, oral ketoconazole and oral doxycycline. After a four-week treatment period, the corneal infiltrate decreased so that only a faint subepithelial opacity remained.</p> <p>Conclusion</p> <p><it>Nocardia </it>organisms should be suspected as the causative agent of any case of keratitis in travelers returning from Asia. With appropriate therapy, <it>Nocardia </it>keratitis resolves, resulting in good visual outcome.</p

    Niobium and niobium-iron coatings on API 5LX 70 steel applied with HVOF

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    The present study aimed to create and characterize niobium and niobium-iron60% coatings applied to steel API 5L X70 using the hypersonic thermal spray process (HVOF). The morphologies of the coatings were analyzed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and profilometry, while the coatings’ hardnesses was evaluated using the Vickers hardness test. The coatings’ corrosion resistance was evaluated by monitoring their open circuit potential and potentiodynamic polarization and performing electrochemical impedance spectroscopy in a 0.05 M NaCl solution. The results showed that the niobium-iron coating contained minor porosity regions, while such defects occurred over large regions of the niobium coating. In terms of corrosion resistance, the coatings obtained in this work promoted a reduction in the substrate’s corrosion rate, but the presence of discontinuities such as porosity compromised the barrier effects of these coatings

    Prevalence of diabetic retinopathy in Tehran province: a population-based study

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    <p>Abstract</p> <p>Background</p> <p>To determine the prevalence and characteristics of diabetic retinopathy (DR) among Iranian patients with diabetes.</p> <p>Methods</p> <p>Design: population-based cross-sectional study.</p> <p>Participants: patients with diabetes aged 25 to 64 years in Tehran province, Iran. This survey was conducted from April to October 2007. The study sample was derived from the first national survey of risk factors for non-communicable disease. Diabetes mellitus was defined as a fasting plasma glucose of ≥ 7.0 mmol/l (126 mg/dl) or more, use of diabetic medications, or a physician's diagnosis of diabetes. All patients known to have diabetes underwent an eye examination by bio-microscope and indirect ophthalmoscope to check for any signs of DR through dilated pupils by + 78 lens. Participants were also interviewed and examined to determine their demographic characteristics, medical conditions and the regularity of their eye visits.</p> <p>Results</p> <p>Among 7989 screened patients, 759 (9.5%) had diabetes. Of them, 639 patients (84.2%) underwent eye examination. Five patients (0.7%) with media opacity were excluded. Of 634 examined patients with diabetes, 240 had some degree of diabetic retinopathy, and the overall standardized prevalence of any retinopathy was 37.0% (95% CI: 33.2-40.8), including 27.3% (95% CI: 23.7-30.8) (n = 175) with non-proliferative and 9.6% (95% CI: 7.3-11.9) (n = 65) with proliferative diabetic retinopathy. Clinically significant macular edema and vision-threatening retinopathy were detected in 5.8% (95% CI: 4.0-7.7) (n = 38) and 14.0% (95% CI: 11.3-16.7) (n = 95) of patients, respectively. Only 143 patients (22.6%) with diabetes had a history of regular eye examination.</p> <p>Conclusion</p> <p>This study demonstrated a high prevalence and poor control of DR in Tehran province. This suggests the need for adequate prevention and treatment in patients with diabetes.</p

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
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