1,357,310 research outputs found
Group B Streptococcal Septicaemia Causing Bilateral Acute Parotitis in an Infant: A Rare Case Report
No full textAcute parotitis is a rare condition in young infants and is characterized by swelling of the parotid gland associated with fever and pain. Staphylococcus aureus is the most common causative agent of this disease. Prevalence is higher in males. We describe the case of a 55-day-old Asian female infant who presented in the emergency department with complaints of fever, reluctance to feed, and irritability with unremarkable examination. During hospitalization pre-auricular edema was observed bilaterally close to the angle of the jaw along with signs of inflammation, greater on the right side. Ultrasound findings showed parotid gland enlargement and blood culture report was positive for Streptococcus pyogenes. Antibiotic treatment with injectable Vancomycin was given for 7 days and the patient had rapid recovery in terms of both symptom improvement and reduction of glandular swelling. This case illustrates the need for consideration of this disease in infants and its likelihood in both genders and emphasizes the early institution of appropriate therapy of acute parotitis for faster recovery and prevention of complications. There is much data on acute parotitis in adolescents but due to the paucity of data in young infants, there is a need to investigate further the causes and treatment of this disease in infants
Evaluation of groundwater resources in Wajid aquifer in Wadi Dawasir area southern Saudi Arabia using computer simulation
No full textSubmitted in partial fulfillment of the requirements
for the Masters Degree in the Department of
Geology at the College of Science- King Saud
UniversityThe study area is entirely located within Wadi Dawasir. It is located
between latitudes 19o30/ 00// N, 21o 00/ 00// N and longitudes 44o 00/ 00// E,
46o30/ 00// E some 670 Km from Riyadh.
Wadi Dawasir area is considered one of the biggest agricultural areas in
the Kingdom of Saudi Arabia. Wajid Formation, which comprises the oldest
Paleozoic sediments, is encountered in the Wadi Dawasir area both in the
outcrop and subsurface. The used water for drinking or irrigation is discharged
from Wajid Aquifer. The lower aquiclude is the Basement Complex, which is
considered an impermeable unit. The aquiclude consists of the basal shale
beds of Khuff Formation in zones where the Wajid Formation is affected by
the Pre-Khuff erosion. The study area is found within the arid zone which
characterize by a high temperature, high rate of evaporation, low rate of
precipitation and low humidity that cause a low recharge of aquifer from
outcrop comparing with a high rate of withdrawal from wells. Wajid Aquifer
may be considered as a single hydraulic unit with fairly homogeneous
lithology
Correction to: Music of metagenomics—a review of its applications, analysis pipeline, and associated tools (Functional & Integrative Genomics, (2022), 22, 1, (3-26), 10.1007/s10142-021-00810-y)
No full textThe co-author Imran Wajid would like to update his second affiliation address to “School of Social Sciences, Istanbul Commerce University, Istanbul, Turkey”. The original article has been corrected
Assessment of the environmental impact of applications in federated clouds
No full textWhile in recent work the energy efficiency of cloud platforms has been emphasized and many approaches have been proposed to reduce the energy consumption in data centres, the evaluation of the environmental impact of applications running in cloud environments is still a research issue, as well as possible techniques to lower their environmental footprint. In the paper the approach taken in the ECO2Clouds project towards assessment of environmental impact of applications and the evaluation of its potential reduction based on adaptive services is illustrated and discussed, including in the discussion the evaluation of alternative possible uses of eco-metrics towards reducing the environmental impact of applications
Matrix versus fracture permeability in a regional sandstone aquifer (Wajid sandstone, SW Saudi Arabia)
No full textSandstones are often characterized as fractured aquifers. We present a case study of the Wajid sandstone, which forms a regional aquifer system in SW Saudi Arabia, where matrix, fracture, and large-scale hydraulic conductivities are coincident. The measurements deal with different scales and methods and are based on porosity and permeability measurements in the laboratory, as well as pumping tests in the field. Porosities of the sandstone samples in general are high and range between less than 5 % and more than 45 %. Gas permeabilities for strongly cemented samples are < 1 mD, whereas most samples range in between 500 and 5,000 mD. There is only a weak anisotropy with preference of the horizontal x-, y-directions. Hydraulic conductivities of the matrix samples (5.5 · 10−6 m/s and 1.1 · 10−5 m/s for the Upper and Lower Wajid sandstone, respectively) were in the same order of magnitude compared to hydraulic conductivities derived from pumping tests (8.3 · 10−5 m/s and 2.2 · 10−5 m/s for the Upper and Lower Wajid sandstone, respectively)
Hydrochemical and Isotopic Investigation of the Groundwater from Wajid Aquifer in Wadi Al-Dawasir, Southern Saudi Arabia
No full textThe Wajid aquifer is considered the main source of water for drinking and irrigation in Wadi Al-Dawasir and Najran, the southern region of Saudi Arabia. This aquifer has been used since the 1960s, and due to the expansion in agricultural activities, the aquifer has been overexploited. The study aims to understand the origin, hydrochemical processes of the groundwater in the shallow unconfined, deep unconfined, and confined parts of the Wajid aquifer in the Wadi Al-Dawasir area. In-situ hydrochemical parameters (pH, temperature, EC, and TDS) were measured in the field, and groundwater samples were collected for major ions and stable isotopes (2H and 18O) measurements in the laboratory. The results show that the groundwater in shallow unconfined, and confined aquifers are of two types; Cl.SO4-Ca. Na and Cl.SO4-Na. Ca; however, groundwater in deep, unconfined aquifers is characterized as HCO3-Ca. Na, and Cl. HCO3-Ca. Na; types of groundwater. The isotopic analysis results reveal that all groundwater samples have values of δ18Oand δ2Hclose to the local and global meteoric water lines, indicating the meteoric origin of Wajid groundwater. Three major hydrochemical processes, including rock weathering, ion exchange, and evaporation, have been identified as key controls on the chemical composition of water in the studied aquifer. The evaporation and ion exchange processes have more influence on the chemical composition of groundwater in the shallow unconfined and confined aquifers. On the contrary, weathering of carbonate minerals affected more the chemistry of groundwater in a deep unconfined aquifer. The unconfined section of the Wajid aquifer shows a reverse pattern of salinity with higher salinity in the recharge area, which is most probably related to the return irrigation water and leaching of salty soil. The open fractures in the upper part of Wajid sandstone most likely act as conduits to percolated saline water to the Wajid aquifer
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Energy efficient and CO2 aware cloud computing: Requirements and case study
No full textEnergy efficiency and CO2 awareness are globallyimportant issues in cloud computing. With increasing attention being paid to the environmental impact of cloud computing there are concerns about the sustainability of cloud computing model as its uptake increases. In this respect, we consider it useful to provide a snapshot of the requirements for energy efficient and CO 2 aware cloud computing to allow the conception and development of new techniques and approaches in this area. Further, we present a case study approach for energy efficient cloud sourcing that aims to build on these requirements. © 2013 IEEE
Sedimentology, stratigraphy and reservoir quality of the Paleozoic Wajid Sandstone in SW Saudi Arabia
No full textThis PhD thesis was embedded in a regional groundwater study in the Paleozoic Wajid Sandstone of southwest Saudi Arabia. The Wajid Sandstone holds important fossil groundwater resources in southwest Saudi Arabia which became increasingly overused due to extensive irrigation for agricultural purpose. This thesis contributed to this groundwater project by evaluating the hydraulic properties of aquifer rocks. This involved also fundamental questions about the sedimentary facies, depositional environments, stratigraphy, architecture, age, and petrology of the Wajid Sandstone Group. The fundamental concept of this PhD thesis is based on the principle of out-crop-analogue studies, i.e. properties of reservoir rocks in the subsurface are investigated in outcrops at the surface. This concept is applicable for the Wajid Sandstone because of a well exposed outcrop belt and extractions wells whose aquifer rocks are exposed only few kilometres from the well location.The outcrop-analogue studies included all basic parameters of reservoir characterization. The major focus was on 1D standard sections where samples were preferentially taken for further analysis. In particular for heterogenous glacigenic deposits also 2D wall panels were composed and analysed. Field surveys lasted altogether around 4 months. The extensive sample collection was sent to Germany and all laboratory and microscopic work was done at the Institut für Angewandte Geowissenschaften of TU Darmstadt. This included measurements and analysis of gamma-ray, porosity, permeability, and thin sections as well as stratigraphic work applying palynology. The multiple data were merged into one data base and analysed by multivariate statistics and principal component analysis.
The study area is located in the south-western part of the Kingdom of Saudi Arabia and comprises the entire outcrop belt of the Wajid Group (ca. 44,000 km2). Correlation of sections is mainly based on unconformities that subdivide the succession into distinct stratigraphic packages. In its outcrop belt, the Wajid Group can be subdivided into 5 formations: the Dibsiyah Formation, Sanamah Formation, Qalibah Formation, Khusayyayn Formation, and Juwayl Formation. Thirteen lithofacies have been distinguished (LF1 through LF 13), which cover the entire spectrum of siliciclastic grain size classifications. Shales and siltstones are relatively rare in the succession, whereas sandstones, especially medium-grained to coarse-grained sandstones are abundant. Conglomerates are locally abundant in the Sanamah Formation and in the Juwayl Formation. A second order descriptor is bioturbation, which is very common in the Dibsiyah Formation, but rare to absent in the other units. The 13 lithofacies have been combined in 9 lithofacies associations (LF-A1 through LF-A9). By stacking the different sections a new standard lithostratigraphic log is presented in this thesis. Sediments of the Wajid Group were deposited during approximately 200 Ma to 260 Ma, depending on the definite depositional age of the Dibsiyah Formation. Extrapolations of sedimentation rates to depositional time show that within the Wajid Group and under the assumption of very conservative sedimentation rates, 62 Ma years are represented in the sediments: 20 Ma in the Dibsiyah Formation, 2 Ma (the length of the Hirnantian) in the Sanamah Formation, 15 Ma in the Khusayyayn Formation, and 25 Ma in the Juwayl Formation. Most likely, the time represented is much less. This means that the sediments preserved do not even cover ¼ of the Palaeozoic era. This is compatible with field observations of abundant unconformities and sedimentary breaks in the starved successions. This indicates that throughout the Palaeozoic, southern Saudi Arabia was located in an epicratonal setting, in which tectonic subsidence and relative sea level changes exerted only minor control.
A specific aim of this study was to systematically explore the heterogeneous glacial and proglacial deposits, develop a genetic depositional model and compare the findings with other regions at the northern rim of Gondwana. Saudi Arabia is one of the few places where both glaciations can be studied in well-preserved sedimentary succession, which formed under similar boundary conditions. Among these are (a) incision of subglacial tunnel valleys according to the ice-loading model, (b) subsequent valley-fill by subaqueous to subaerial proglacial deposits in front of an oscillating, polythermal ice-shield, (c) intra-formational erosional events through repeated ice advance, (d) widespread and large-scale soft sediment deformation due to glacial surge during deglaciation, (e) marine transgression as a consequence of eustatic sea-level rise following deglaciation. The general pattern fits well with observations from northern Africa, pointing to closely coupled glaciological processes along the northern margin of the Gondwana ice-shield during Upper Ordovician glaciation. Although the same general patterns apply for the Permo-Carboniferous glaciation, styles and petrographical properties differ most probably due to a more complex ice-flow pattern with a rougher topography after the Hercynian event and contrasting weathering.
This thesis presents the first statistical analysis of porosities and permeabilities over the entire Wajid Sandstone Group in the outcrop belt and links these values with lithofacies and microfacies studies in order to identify controlling factors. Furthermore, for the first time a combined approach of standard mini permemeter and sophisticated column permeameter measurements were carried out, the latter enables to convert gas in water permeabilities. Although the data of this thesis confirms the overall good reservoir quality, also wide scatter is obvious. This is particularly the case for permeabilities. High porosities do not guarantee high permeabilities and correlation of both is weak, although a positive trend exists. This means that porosities cannot be used to predict permeabilities accurately. Medians of porosities range from 23 to 27% and 15 to 28% for formations and lithofacies types respectively. Different permeability measurements all show highest medians of 1500 to 2000 mD for the Khusayyayn Formation and lowest medians of 300 to 1400 mD for the Dibsiyah Formation. The variability is highest for the Sanamah Formation and the Juwayl Formation. To analyse these heterogeneities and identifying controlling factors, two approaches were applied: (i) lithofacies types, which represent grain texture and sedimentological structures at the mesoscopic scale in the field, and (ii) microfacies analysis using thin sections and raster electron microscopy of selected samples. Referring to lithofacies, the following trends have been identified. Siltstone and fine sandstones exhibit the highest porosities, but permeability is low for silt-dominated samples. Pebbly sandstones show reduced porosities and permeabilities, most probably because of general poorer mixing. Highest porosities and permeabilities were found for cross-bedded sandstones. Thick massive sandstones in the Juwayl Formation, which are expected to have very good reservoir properties show surprisingly high variability. Anisotropy is generally low except for siltstones, and bioturbated sandstones. Porosites and permeabilities are most closely related to each other for sandy to pebbly, cross bedded lithofacies types. Bioturbated samples and massive sandstones show a relatively high permeability compared to their porosity, which may be interpreted as homogenization of the grain fabric and/or secondary porosity by leaching. Finer grained samples show the expected opposite trend, but some exceptions exist.
Referring to microfacies, the following trends have been identified. High permeabilities can be linked with open pore space, pore connectivity, and rounding, but less with sorting. Low permeabilities are linked with increased proportions of pseudo matrix and cementation by iron oxides, calcite, and/or quartz. The Khusayyayn Formation has higher feldspar content. This leads to higher secondary porosity, proportions of pseudo matrix, and some calcite cement. As destruction and formation of secondary porosity prevails the highest average permeability in the entire Wajid Sandstone Group is observed. Biomodal grain distribution in the Juwayl Formation leads to strongly reduced permeability despite the favourable main grain texture. Secondary leaching in the Juwayl Formation is more heterogeneous and cemented or matrix rich patches are common. Furthermore, the Juwayl Formation exhibits lower porosities at the same permeabilities, which is interpreted as a more efficient connectivity due to secondary leaching. Iron cementation is strongest in the lower Wajid Sandstone Group, in particular in the Dibsiyah Formation. This seems to be the major reason for reduced permeabilities there. Likely, the iron originates from continental weathering of shield areas during the warm Cambro-Ordovician period and was remobilized during burial. The Qusaiba Shale presumably hindered the circulating pore waters to penetrate the upper Wajid Sandstone equally.
When comparing water peremabilities of matrix samples with pumping tests, both are surprisingly close and point out the high relevance of matrix permeabilities for groundwater storage and groundwater flow in the Wajid Sandstone. Pumping tests yield a slightly higher hydraulic conductivity for the Lower Wajid Aquifer. Matrix permeabilities for water show the same trend but differences are even lower. Whereas hydraulic permeabilities for matrix and pumping tests are very close in the Lower Wajid Aquifer, matrix permeabilities are almost one magnitude lower in the Upper Wajid Aquifer. In conclusion, this makes matrix permeabilities of prime importance in the Wajid Aquifers. Hence, the investigation of sedimentary heterogeneities at the outcrop and microscopic scale is of specific relevance for the prediction of reservoir quality in the Wajid Sandstone Group
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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