36 research outputs found

    Large variations in disease severity, death and ICU admission of 2993 patients infected with SARS-CoV-2: The potential impact of genetic vulnerability.

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    BACKGROUND: The COVID-19 pandemic has had an immeasurable impact, affecting healthcare systems, the global economy, and society. Exploration of trends within the existing COVID-19 data may guide directions for further study and novel treatment development. As the world faces COVID-19 disease, it is essential to study its epidemiological and clinical characteristics further to better understand and aid in its detection and containment. METHODS: We aimed to study the clinical characteristics of patients infected with COVID-19 in Dubai, a multi-national Society. RESULTS: Our findings demonstrate that during the first wave of the COVID-19 epidemic, age, gender, and country of origin were associated with more severe cases of COVID-19, higher risk for hospitalization and death. Male individuals between 41 and 60 years of age from India had the most significant hospitalization and death predictor (p=.0001). The predictors for COVID-19 related deaths were slightly less than UAE Nationals by individuals from GCC (p=.02) that were followed closely behind by Pilipino (p=.02) and Arabs (p=.001). CONCLUSION: The vulnerability of individuals to infection and in the spectrum of COVID-19 symptoms remains to be understood. There are large variations in disease severity, one component of which may be genetic variability in responding to the virus. Genomics of susceptibility to COVID-19 infection and the wide variation in clinical response to COVID-19 in patients should become active investigation areas

    The mid-Holocene sea-level change in the Arabian Gulf

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    The mid-Holocene sea-level highstand is a well-known phenomenon in sea-level science, yet the knowledge on the highstand’s spatial and temporal distribution remains incomplete. Here we study the southwest coast of the Arabian-Persian Gulf where a mid-Holocene sea-level highstand and subsequent sea-level fall may have occurred due to the Earth crustal response to meltwater load. Sea-level indicators were established using standard facies analysis and error calculations, then constrained through glacio-isostatic adjustment (GIA) modelling and though procedures based on Gaussian Process and exponential decay analysis. This work allowed to identify the highstand at 1.6 ± 0.4 m occurring 6.7–6.0 ka, in excellent agreement with GIA model results. The subsequent shoreline migration followed the geophysical constraint by prograding in line with the sea-level fall until around 3 ka. Then, the strength of the external control weakened and internal processes, in particular sediment binding through microbial activity, started controlling the geometry of the accommodation space. </jats:p

    Impact of ISO 55000 on organisational performance: evidence from certified UAE firms

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    The purpose of this study is to investigate the impact of implementing the International Organisation for Standardisation asset management standard (ISO 55000) on organisational performance. In particular, does following the ISO 55000 requirements and recommendations affect organisational performance? This study investigates this issue by identifying relevant asset management key performance indicators (KPIs) through a comprehensive literature review and classifying these KPIs using the balanced-scorecard-framework. Then, the KPIs were validated by expert opinions through a questionnaire and non-parametric hypothesis testing. Finally, using the relevant KPIs, this study assesses the impact of ISO 55000 with a set of ISO 55000-certified companies in the United Arab Emirates. Hypothesis testing on the difference between the status of each KPI before and after ISO 55000 implementation used linguistic assessment and a sign test for two non-parametric dependent samples. According to industry experts, increasing market share is not a relevant KPI in asset management. However, ISO 55000 has a positive effect on all the identified perspectives (financial, customer, business processes, and learning and growth), indicating that organisations adopting ISO 55000 International Standard certification will be able to achieve better performance from the effective and efficient management of their assets. Consequently, investing in such systems is valuable. © 2018 Informa UK Limited, trading as Taylor & Francis Group

    Origin of Drusy Dolomite Cement in Permo-Triassic Dolostones, Northern United Arab Emirates

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    While the characteristics and origin of drusy calcite cement in carbonate deposits is well constrained in the literature, little attention is paid to drusy dolomite cement. Petrographic observations, stable isotopes, and fluid-inclusion microthermometry suggest that drusy dolomite cement in Permo-Triassic conglomerate/breccia dolostone beds in northern United Arab Emirates has precipitated as cement and not by dolomitization of drusy calcite cement. The low δ18OVPDB (−9.4‰ to −6.2‰) and high homogenization temperatures of fluid inclusions in drusy dolomite (Th = 73–233 °C) suggest that dolomitization was caused by hot basinal brines (salinity = 23.4 wt% NaCl eq.). The δ13CVPDB values (+0.18‰ to +1.6‰) and 87Sr/86Sr ratio (0.708106 to 0.708147) indicate that carbon and strontium were derived from the host marine Permo-Triassic carbonates. Following this dolomitization event, blocky calcite (Th = 148 °C; salinity = 20.8 wt% NaCl eq.) precipitated from the hot basinal brines. Unravelling the origin of drusy dolomite cement has important implications for accurate construction of paragenetic sequences in carbonate rocks and decipher the origin and chemistry of diagenetic waters in sedimentary basins

    Multiscale investigation of pore structure heterogeneity in carbonate rocks using digital imaging and SCAL measurements: A case study from Upper Jurassic limestones, Abu Dhabi, UAE.

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    This study presents a comprehensive analysis of rock properties for a selected group of six carbonate reservoir rock samples revealing complex structures at various length scales. Experimental laboratory methods as well as image analysis techniques were conducted in this study to characterize the macro- and micro-pores in mud- and grain-dominated limestones samples from the Upper Jurassic Arab Formation (Arab D member). Mercury Injection Capillary Pressure (MICP), porosimeter, and permeameter lab measurements were employed to assess the pore network heterogeneity and complexity. In addition, a multiscale rock imaging approach was implemented to detect grain and pore phases at several length scales using Thin Sections (TS), Scanning Electron Microscopy (SEM), Focused Ion Beam Scanning Electron Microscopy (FIB-SEM), as well as 3D X-ray Computed Tomography (CT), and micro-computed tomography images (MCT). Furthermore, the multifractal analysis method was applied on the MICP and FIB-SEM to characterize quantitatively the heterogeneity of the pores in the studied samples. Heterogeneous samples 3R, 4M, 5W, and 6M display the highest non-uniformity degree Δα values, falling within the range of [1.21, 1.39] based on FIB-SEM images. Samples 1G, 2R, 3R, and 5W exhibit more heterogeneous pore structure, with Δα values ranging from 0.73 to 1.49 based on the MICP experiments. The results and findings confirm the effectiveness of multifractal parameters Δα and the asymmetry degree in the vertical axis Δf(α) in quantifying and characterizing rock heterogeneity

    Experimental and digital investigations of heterogeneity in lower cretaceous carbonate reservoir using fractal and multifractal concepts

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    Abstract Characterization and prediction of reservoir heterogeneity are crucial for hydrocarbon production. This study applies the multifractal theory using both numerical and experimental data to characterize quantitatively the heterogeneity of pore structures in Lower Cretaceous limestone reservoir from the United Arab Emirates. Fractal dimensions calculated from three dimensional digital images showed good correlation (R2 =  + 0.69) with experimental high-pressure mercury injection (HPMI) measurements. Moreover, both experimental and numerical fractal dimensions correlate well with experimental HPMI porosity measurements. Multifractal parameters such as the non-uniformity degree of the pore structures Δα, the asymmetry degree in the vertical axis Δf(α), the concentration of pore size distribution α 0 and the asymmetry degree in the horizontal axis R d estimated from digital and experimental data correlated well and revealed ability to quantitatively describe samples heterogeneity. The ranges of digital and experimental multifractal parameters provided the means to differentiate between homogeneous and heterogeneous samples

    Classification for limestone textures [27,28].

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    This study presents a comprehensive analysis of rock properties for a selected group of six carbonate reservoir rock samples revealing complex structures at various length scales. Experimental laboratory methods as well as image analysis techniques were conducted in this study to characterize the macro- and micro-pores in mud- and grain-dominated limestones samples from the Upper Jurassic Arab Formation (Arab D member). Mercury Injection Capillary Pressure (MICP), porosimeter, and permeameter lab measurements were employed to assess the pore network heterogeneity and complexity. In addition, a multiscale rock imaging approach was implemented to detect grain and pore phases at several length scales using Thin Sections (TS), Scanning Electron Microscopy (SEM), Focused Ion Beam Scanning Electron Microscopy (FIB-SEM), as well as 3D X-ray Computed Tomography (CT), and micro-computed tomography images (MCT). Furthermore, the multifractal analysis method was applied on the MICP and FIB-SEM to characterize quantitatively the heterogeneity of the pores in the studied samples. Heterogeneous samples 3R, 4M, 5W, and 6M display the highest non-uniformity degree Δα values, falling within the range of [1.21, 1.39] based on FIB-SEM images. Samples 1G, 2R, 3R, and 5W exhibit more heterogeneous pore structure, with Δα values ranging from 0.73 to 1.49 based on the MICP experiments. The results and findings confirm the effectiveness of multifractal parameters Δα and the asymmetry degree in the vertical axis Δf(α) in quantifying and characterizing rock heterogeneity.</div
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