334 research outputs found

    A Macroeconometric Model for Saudi Arabia

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    This Open Access Brief presents the KAPSARC Global Energy Macroeconometric Model (KGEMM). KGEMM is a policy analysis tool for examining the impacts of domestic policy measures and global economic and energy shocks on the Kingdom of Saudi Arabia. The model has eight blocks (real sector, fiscal, monetary, external sector, price, labor and wages, energy, population, and age cohorts) that interact with each other to represent the Kingdom’s macroeconomy and energy linkages. It captures New Keynesian demand-side features anchored to medium-run equilibrium and long-run aggregate supply. It applies a cointegration and equilibrium correction modeling (ECM) methodology to time series data to estimate the model’s behavioral equations in the framework of Autometrics, a general-to-specific econometric modeling strategy. Hence, the model combines ‘theory-driven’ approach with ‘data-driven’ approach. The Brief begins with an introduction to the theoretical framework of the model and the KGEMM methodology and then walks the reader through the structure of the model and its behavioral equations. The book closes with simulations showing the application of the model. Providing a detailed introduction to a cutting-edge, robust predictive model, this Brief will be of great use to researchers and policymakers interested in macroeconomics, energy economics, econometrics, and more specifically, the economy of Saudi Arabia

    COVID-19 Induced Myocarditis: A Rare Cause of Heart Failure.

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing lung injury has been well documented in the literature recently. They do so primarily by binding to the membrane-bound form of angiotensin-converting enzyme 2 (ACE-2) receptors. However, since these receptors are also expressed in the heart and blood vessels, coronavirus can also cause damage to these organs by binding to the ACE-2 receptors. A typical case of coronavirus disease 2019 (COVID-19) usually presents with respiratory symptoms like cough and shortness of breath accompanied by fever. The literature regarding this pandemic has been growing and now we know very well that the effect of this deadly virus is not restricted to the lungs alone. It can, unfortunately, cause various other complications ranging from neurological damage to even myocardial injury in rare cases. We present an interesting case of a 40-year-old male patient who presented to us with shortness of breath. When further investigated, the patient was found to have a new onset of heart failure secondary to COVID-19 induced myocarditis

    A family of ratio estimators for population mean in extreme ranked set sampling using two auxiliary variables

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    In this paper we have adopted the Khoshnevisan et al. (2007) family of estimators to extreme ranked set sampling (ERSS) using information on single and two auxiliary variables. Expressions for mean square error (MSE) of proposed estimators are derived to first order of approximation. Monte Carlo simulations and real data sets have been used to illustrate the method. The results indicate that the estimators under ERSS are more efficient as compared to estimators based on simple random sampling (SRS), when the underlying populations are symmetric

    Rapid and efficient ultrasonic assisted adsorption of diethyl phthalate onto FeIIFe2 IIIO4@GO: ANN-GA and RSM-DF modeling, isotherm, kinetic and mechanism study

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    Herein, an ultrasonic assisted dispersive magnetic solid-phase adsorption method along with a high-performance liquid chromatography system for the diethyl phthalate (DEP) removal was developed. In this regard, magnetic iron oxide/graphene oxide (MGO) nanocomposites were prepared by a simple and effective chemical co-precipitation method, followed by nucleation and growth of nanoparticles. The structure and morphology of MGO was identified by Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) spectroscopy X-ray diffraction (XRD), Vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption techniques. The interactive and main effect of parameters such as pH, adsorbent dosage, sonication time and concentration of DEP involved in the adsorption process were set within the ranges 3.0�11.0, 0.10�0.50 g L�1, 1�5 min, 5�10 mg/L, respectively. Root means square error (RMSE), mean absolute error (MAE), absolute average deviation (AAD), and coefficient of determination (R2) was employed to examine the applicability of the response surface methodology (RSM) and artificial neural network (ANN) models for the description of experimental data. Compared to RSM, the ANN showed a more accurate performance for modeling the process of DEP adsorption. Using genetic algorithm-ANN, optimum conditions were set to 5.38, 334.7 mg/L, 3.723 min and 4.21 mg/L for pH, adsorbent dose, sonication time and concentration of DEP, respectively. Under the optimized conditions, the maximum adsorption capacity and adsorption factors were 116.933 mg/g and 100, respectively, while the relative standard deviations (RSDs) was <1.6 (N = 5). The isotherm models display that the Langmuir has the best fit with the equilibrium data, and adsorption kinetics followed the pseudo-second-order model. The thermodynamic results confirmed that the sorption was endothermic and occurred spontaneously. The results exhibited that MGO has excellent potential as an adsorbent for the removal of phthalates from the contaminated water. © 2019 Elsevier B.V

    Heavy Metal Levels in Vegetables and Soil Cultivated with Industrial Wastewater from Different Sites of Chunian and Jamber, District, Kasur

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    In human diet, vegetables play important role to maintain the physiological conditions. Due to anthropogenic activities and pollution, the food items become contaminated. The present study was performed to evaluate the level of heavy metals in the vegetables irrigated with wastewater across Chunian and Jamber, district, Kasur. Level of heavy metals from the study area like Zinc, Lead and chromium in the soil, water and vegetables was compared. The four sites of each city and 10 vegetables e.g. potato, radish, carrot, fenugreek, spinach, tomato, Onion, Turnip, Cauliflower, Pangalo were selected to conduct the experiment. The vegetables were irrigated with industrial wastewater and the concentration of heavy metals was measured by the atomic absorption spectrophotometer (AAS). We concluded that the level of heavy metals was beyond the FAO limits in irrigated water due to industrial waste. In Jamber and Chunian, the level of Zn and Pb was high and beyond the FAO safe limits in the all water sample, the level of Cr was much higher only in the water sample of one site from Jamber. The concentration of zinc was higher in soil samples as compared to lead and chromium. Zn and Pb in vegetables of study area were labeled as priority pollutants but this concentration was within the safe limits set by FAO. However, constant inspection of heavy metals is recommended to avoid accumulation in the food chain and thus avoid human health risks. Keywords: Atomic absorption spectrophotometer, Heavy metals, Industrial wastewater, Vegetables

    The Effects of Serotonin Receptor Antagonists on Contraction and Relaxation Responses Induced by Electrical Stimulation in the Rat Small Intestine

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    Background: The main source of 5-HT in body is in enterchromafin cells of intestine, different studies mentioned different roles for endogenous 5-HT and receptors involved and it is not clearified the mechanism of action of endogenous 5-HT. Objectives: To study the role of endogenous 5-HT on modulation of contraction and relaxation responses induced by electrical field stimulation (EFS) in different regions of the rat intestine. Materials and Methods: Segments taken from the rat duodenum, jejunum, mid and terminal ileum were vertically mounted, connected to a transducer and exposed to EFS with different frequencies in the absence and presence of various inhibitors of enteric mediators i. e. specific 5-HT receptor antagonists. Results: EFS-induced responses were sensitive to TTX and partly to atropine, indicating a major neuronal involvement and a cholinergic system. Pre-treatment with WAY100635 (a 5-HT1A receptor antagonist) and granisetron up to 10.0 µM, GR113808 (a 5-HT4 receptor antagonist), methysergide and ritanserin up to 1.0 µM, failed to modify responses to EFS inall examined tissues. In the presence of SB258585 1.0 µM (a 5-HT6 receptor antagonist) there was a trend to enhance contraction in the proximal part of the intestine and reduce contraction in the distal part. Pre-treatment with SB269970A 1.0 µM (5-HT7 receptor antagonist) induced a greater contractile response to EFS at 0.4 Hz only in the duodenum. Conclusions: The application of 5-HT1A, 5-HT2, 5-HT3, 5-HT4, 5-HT6 and 5-HT7 receptor antagonists, applied at concentrations lower than 1.0 µM did not modify the EFS-induced contraction and relaxation responses, whichsuggests the unlikely involvement of endogenous 5-HT in mediating responses to EFS in the described test conditions. Keywords: Electric Stimulation Therapy; Serotonin 5-HT1 Receptor Antagonists; Intestine, Smal

    Parametric analysis of turning HSLA steel under minimum quantity lubrication (MQL) and nanofluids-based minimum quantity lubrication (NF-MQL) : a concept of one-step sustainable machining

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    Abstract: The requirement of cost-effective and ecological production systems is crucial in the competitive market. In this regard, the focus is shifted towards sustainable and cleaner machining processes. Besides the clean technologies, effective parametric control is required for machining materials (such as High Strength Low Alloy Steels) specifically designed for high strength applications having superior physio-chemical properties. Therefore, the machinability complexities require optimized solutions to reduce temperature elevation and tooling costs and improve machining of these materials. Complying to the market needs, this research examines the effectiveness of nanofluid on tool life, wear mechanisms, surface roughness (Ra), surface morphology, and material removal rate (MRR) in turning of 30CrMnSiA (HSLA) using minimum quantity lubrication (MQL) and SiO2-H2O nanofluids (NF-MQL). A systematic investigation based on physical phenomena involved is carried out considering four process parameters (cutting speed (VC), feed rate (Fr), depth of cut (DOC), and mode of lubrication for machining. Fr is found as the vital parameter for surface roughness while MRR is highly influenced by DOC regardless of lubrication approach. One-step sustainability technique is applied, in which process variables used for roughing conditions are analogous to attain surface comparable to finished machining without compromising process efficiency and demonstrate its feasibility through optimal settings under NF-MQL. Multi-response optimization proved the NF-MQL machining condition as the best alternative which result in 28.34% and 5.09% improvements for surface roughness and MRR, respectively. Moreover, the use of SiO2 is recommended over MQL due to lower energy consumption, low tool wear, and better surface integrity, sustainable liquid, and related costs

    The Incremental Cooperative Design of Preventive Healthcare Networks

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    This document is the Accepted Manuscript version of the following article: Soheil Davari, 'The incremental cooperative design of preventive healthcare networks', Annals of Operations Research, first published online 27 June 2017. Under embargo. Embargo end date: 27 June 2018. The final publication is available at Springer via http://dx.doi.org/10.1007/s10479-017-2569-1.In the Preventive Healthcare Network Design Problem (PHNDP), one seeks to locate facilities in a way that the uptake of services is maximised given certain constraints such as congestion considerations. We introduce the incremental and cooperative version of the problem, IC-PHNDP for short, in which facilities are added incrementally to the network (one at a time), contributing to the service levels. We first develop a general non-linear model of this problem and then present a method to make it linear. As the problem is of a combinatorial nature, an efficient Variable Neighbourhood Search (VNS) algorithm is proposed to solve it. In order to gain insight into the problem, the computational studies were performed with randomly generated instances of different settings. Results clearly show that VNS performs well in solving IC-PHNDP with errors not more than 1.54%.Peer reviewe

    Phylogeny, sequence-typing and virulence profile of uropathogenic Escherichia coli (UPEC) strains from Pakistan

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    Abstract Background Escherichia coli lineage ST131 predominates across various spectra of extra-intestinal infections, including urinary tract infection (UTI). The distinctive resistance profile, diverse armamentarium of virulence factors and rapid global dissemination of ST131 E. coli makes it an intriguing pathogen. However, not much is known about the prevalence and genetic attributes of ST131 lineage in Pakistan. Methods We estimated prevalence and genetic attributes of E. coli ST131 isolates causing UTI among 155 randomly selected samples. Samples were analyzed for phylogenetic grouping, O-typing and fumC/fimH typing. Isolates were further tested for the ESBL and virulence factors using PCR. Results Overall, 59% of the UPEC isolates belonged to the phylogenetic group B2, followed by D = 28%, B1 = 8% and A = 5%. Among 18 different Sequence-types, ST131 was the dominant lineage (n = 71; 46%) out of which 72% of the isolates were assigned to the phylogenetic group B2, while 61% adhered to the serogroup O25b. FumC/fimH typing confirmed 49% of the ST131 as H30 sub-types. In this study, significant numbers of the identified ST131 isolates were MDR and 42% showed ESBL phenotypes, out of which 37% carried bla-CTX-M-15. Moreover, different virulence factors were detected in following percentages: fimH,155(100%), iutA 86 (55%), feoB 76 (49%), papC 75 (48%), papGII 70 (45%), kpsMTII 40 (26%), papEF 37 (24%), fyuA 37 (24%), usp 22 (14%), papA 20 (13%), sfa/foc20 (13%), hlyA 18 (12%), afa 15 (10%), cdtB 11 (7%), papGI 6 (4%), papGIII 6 (4%), kpsMTIII 4 (3%) and bmaE2 (1%). Conclusion Conclusively, this study provides important insight into the genetic and virulence attributes of pandemic MDR ST131 strains involved in UTIs. It also highlights higher prevalence of ST131-O25b-H30 UPEC isolates in patients, which was previously unreported from this part of globe.https://deepblue.lib.umich.edu/bitstream/2027.42/152123/1/12879_2019_Article_4258.pd
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