150 research outputs found
Influence of chitosan addition on resorcinol-formaldehyde xerogel structure
Gels are usually not environment-friendly due to their difficult biodegradability. Therefore, the addition of chitosan, even in small amounts, will make such gels biodegradable and thus can be useful in many applications that require environment-friendly materials. The addition of small quantities of chitosan to the reacting solution resorcinol-formaldehyde xerogel was investigated. Different hybrid resorcinol-formaldehyde-chitosan xerogels were characterized by dierent techniques, including Raman spectra, FTIR, XRD, TGA, SEM, surface area and porosity analyzer, and CHNS/O microanalyzer. It was seen that the addition of chitosan, even in a minor quantity, has a significant influence on the structural features of the resulting xerogels. The lattice order and crystallinity, chemical functions, thermal stability, morphology, elemental ratio, pore structure, and appearance were changed by adding chitosan into the xerogel structure. - 2019 by the authors. Licensee MDPI, Basel, Switzerland.This publication was made possible by the NPRP award (NPRP 08-014-2-003) from the Qatar National Research Fund (a member of Qatar Foundation). Statements made herein are the sole responsibility of the authors. Technical support from the Department of Chemical Engineering, Central Laboratory Unit (CLU) and Gas Processing Centre (GPC) at Qatar University is also acknowledged. Further, the publication of this article was funded by the Qatar National Library.Scopu
Macro and Micro Earnings Manipulation: The Role of Accounting Standard Setting Process
Preparers of financial statements are in aposition to influence the view of economic reality presented inthose statements to interested parties. The term 'macromanipulation'is used to describe the lobbying of preparersagainst regulators (accounting standards setters) to persuadethem to produce regulation that is more favorable to theinterests of preparers. The aime of this paper is to introduce asuggested tool that could be used to ascertain why somefinancial accounting standards turn out to the benefit of one ofthe stakeholders involved in the process of accountingstandards setting. This paper utilizes the construct of power toreveal the influences from parties involved in the process ofaccounting standards setting. The comprehensive incomereporting standard is used in this paper as an example of thesetypes of standard that may involve 'macro-manipulation'
The Usefulness of Different Accounting Earnings Measures: The Case of Egypt
The objective of this paper is to investigate whichmeasure of accounting income (comprehensive income,operating income, or net income) is more useful to equityinvestors in explaining future earnings, future cash flows, andstock returns. This study proposes that different measures ofincome are more useful for different uses. The research isundertaken within the Egyptian environment that allowsconsiderable asset revaluations and holds the reporting ofextraordinary items. Therefore, such environment provides arich ground for testing the expected effects of reportingcomprehensive income and its components on the Egyptianinvestors. The results do not support the superiority ofcomprehensive income measures in explaining the followingperiod’s net income compared to net income. None of the fourtested measures of earnings is able to explain the followingperiod’s cash flows. Operating income is superior to the otherthree measures of income in explaining stock return
An Interpretive Analysis of how Audit Quality is Perceived in Economies in Transition
With the movement of many internationalaccounting firms into Egypt, and the growth of local auditfirms, it is particularly interesting, and relevant forgovernmental legislators, to study how the providers of theaudit service perceive the quality of what they do. In thissense, the purpose of this paper is to report the perceptions ofprofessional auditors in Egypt concerning how they perceivethe quality of the service they provide. The paper also analyzesdifferences between perceptions of the Big 4 audit firms andother local audit firms. Based on 28 semi-structuredinterviews, it was revealed that the interviewees generallybelieved that the audit quality is preserved high in thepresence of four factors: (1) high ethical standards to guideand regulate the profession; (2) a well planned and conductedaudit; (3) a more knowledgeable audit team; and (4) having agood relationship with the client management
Influence of carbon uniformity on its characteristics and adsorption capacities of CO2 and CH4 gases
Activated carbons of resorcinol-formaldehyde aerogels (AC-RFA) were prepared and mixed with multiwall carbon nanotubes (MWCNTs) with various ratios. Samples were characterized by different techniques. The novelty of the study is in evaluating the effect of uniformity of carbon nanocomposites on their performance for the adsorption of CH4 and CO2 gases as well predicting the separation of their mixtures. The results indicated that, by increasing the percentage of MWCNTs into the sample, its structural uniformity and order ascend. The capacities of CH4 and CO2 by adsorption were measured at various temperatures, and were correlated with the extended dual site Langmuir (DSL) model. Overall, results showed that the adsorption capacity of MWCNTs towards gases is relatively very low compared to that of activated carbons. The DSL model was utilized to forecast the separation of the binary CO2/CH4 mixed gas based on knowledge of single component adsorption isotherm parameters. Adsorption equilibrium data of the CO2/CH4 binary gas mixture was forecasted at different temperatures by DSL model in accordance with the perfect-negative (PN) or perfect-positive (PP) behaviors on the heterogeneous surface of the adsorbent.Acknowledgments: This publication was made possible by the NPRP award (NPRP 08-014-2-003) from the Qatar National Research Fund (a member of Qatar Foundation). Statements made herein are the sole responsibility of the authors. Technical support from the Department of Chemical Engineering, Central Laboratory Unit (CLU) and Gas Processing Centre (GPC) at Qatar University is also acknowledged. Further, the publication of this article was funded by the Qatar National Library.Scopus2-s2.0-8509922365
Influence of casting solvents on co2/ch4 separation using polysulfone membranes
Polysulfone membranes exhibit resistance to high temperature with low manufacturing cost and high efficiency in the separation process. The composition of gases is an important step that estimates the efficiency of separation in membranes. As membrane types are currently becoming in demand for CO2/CH4 segregation, polysulfone will be an advantageous alternative to have in further studies. Therefore, research is undertaken in this study to evaluate two solvents: chloroform (CF) and tetrahydrofuran (THF). These solvents are tested for casting polymeric membranes from polysulfone (PSF) to separate every single component from a binary gas mixture of CO2/CH4 . In addition, the effect of gas pressure was conducted from 1 to 10 bar on the behavior of the permeability and selectivity. The results refer to the fact that the maximum permeability of CO2 and CH4 for THF is 62.32 and 2.06 barrer at 1 and 2 bars, respectively. Further, the maximum permeability of CF is 57.59 and 2.12 barrer at 1 and 2 bars, respectively. The outcome selectivity values are 48 and 36 for THF and CF at 1 bar, accordingly. Furthermore, the study declares that with the increase in pressure, the permeability and selectivity values drop for CF and THF. The performance for polysulfone (PSF) membrane that is manufactured with THF is superior to that of CF relative to the Robeson upper bound. Therefore, through the results, it can be deduced that the solvent during in-situ synthesis has a significant influence on the gas separation of a binary mixture of CO2/CH4 .Scopu
DNA barcode assessment and population structure of aphidophagous hoverfly <i>Sphaerophoria scripta</i>:Implications for conservation biological control
With the advent of integrated pest management, the conservation of indigenous populations of natural enemies of pest species has become a relevant practice, necessitating the accurate identification of beneficial species and the inspection of evolutionary mechanisms affecting the long-time persistence of their populations. The long hoverfly,Sphaerophoria scripta, represents one of the most potent aphidophagous control agents due to a worldwide distribution and a favorable constellation of biological traits. Therefore, we assessed five EuropeanS. scriptapopulations by combining molecular (cytochromecoxidase subunit I-COI, internal transcribed spacer 2-ITS2, and allozyme loci) and morphological (wing size and shape) characters.COIsequences retrieved in this study were conjointly analyzed with BOLD/GenBank sequences of the otherSphaerophoriaspecies to evaluate whetherCOIpossessed a sufficient diagnostic value as a DNA barcode marker to consistently delimit allospecific individuals. Additionally, the aforementioned characters were used to inspect the population structure ofS. scriptain Europe using methods based on individual- and population-based genetic differences, as well as geometric morphometrics of wing traits. The results indicate numerous sharedCOIhaplotypes among differentSphaerophoriaspecies, thus disqualifying this marker from being an adequate barcoding region in this genus. Conversely, the analyses of population structuring revealed high population connectivity across Europe, therefore indicating strong tolerance ofS. scriptato environmental heterogeneity. The results imply a multilocus approach as the next step in molecular identification of differentSphaerophoriaspecies, while confirming the status ofS. scriptaas a powerful biocontrol agent of economically relevant aphid pests
Synthesis, docking and evaluation of novel fused pyrimidine compounds as possible lead compounds with antibacterial and antitumor activities
Reaction of a series of hydrazonoyl chlorides with substituted aminopyrimidines afforded good selectivity in most cases leading either to formation of new imidazo[1,2-a]pyrimidine derivatives, or regioisomeric hydrazonamide adducts. The compounds were evaluated for antibacterial and anticancer activities. Screening against 'E. Coli', 'P. aeruginosa', 'S. aureus', 'S. epidermidis', 'B. subtilis' and 'K. rhizophila' did identify several different compound types with MIC of 0.1-0.4 mg/mL. Anticancer evaluation against a HeLa cell line identified one imidazo[1,2-a]pyrimidine lead. An 'in silico' target fishing analysis suggest three possible high value protein targets, Tankyrase-2 (Tank-2), Cyclin-dependent kinase (CDK2) and Epidermal growth factor tyrosine kinase receptor (EGFR), with modelling fit against co-crystallized known ligands. This provides a new structural family lead for further investigation of molecular targets and potential SAR activity development
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
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