63477 research outputs found
Sort by
Evaluating the ecotoxicity of polymer-coated SPIONs for scale inhibition using a zebrafish embryo model
No full textSuperparamagnetic iron oxide nanoparticles (SPIONs) are increasingly explored as sustainable scale inhibitors in oilfield operations, offering high efficiency, magnetic recoverability, and reduced chemical discharge. This study evaluates the environmental safety of two polymer-coated SPION formulations—SPIONs-TSC-PPEA and SPIONs-TSC-PASP—through a comprehensive analysis in the zebrafish embryo model, aligned with OECD guidelines. The nanocomposites demonstrated complete inhibition of gypsum and calcite scaling at ≤ 10 ppm, while maintaining high survival (>90 %), hatching, and minimal teratogenicity in zebrafish embryos up to 200 ppm—representing a 20 × safety margin. Mechanistic assessments of cardiac and neuromotor functions revealed only mild, adaptive effects. Physicochemical characterization confirmed stable, monodispersed nanoparticles with low dissolution and high surface charge. These findings confirm the low ecotoxicological risk of SPION-based inhibitors, supporting their integration into environmentally responsible scale management strategies. This study advances sustainable nanotechnology solutions by bridging performance, recyclability, and environmental compliance.This work was supported by Grant no. ARG01-0602-230467 from Qatar National Research Fund (a member of the Qatar Foundation). Open Access funding is provided by Qatar National Library. The statements made herein are solely the responsibility of the authors. The authors thank the Research Council of Norway for the financial support of the Ph.D. Candidates Ali H. Karaly, and Abdelrahman Abdelaal, through the project PETROMAKS 2 program/ Research Project No. 300754. The authors also acknowledge the support provided by the Qatar University Zebrafish Core Facility at the BRC, as well as the efforts of Ms. Enas Al Absi and Mr. Ahmad Elwan for maintaining the facility
Economically viable marine algae-based fish feed production in Qatar
No full textExpanding sustainable aquaculture is crucial for meeting the growing demand for fish and ensuring global food security. This study explored the technical feasibility and economic viability of locally grown marine or brackish microalgae as fish feed ingredients. Initially, the biomass digestibility of five indigenous strains (e.g., Coelastrella sp., Dunaliella sp., Picochlorum sp., Spirulina sp., and Tetraselmis sp.) was assessed for Nile tilapia (Oreochromis niloticus); the brackish Spirulina sp. showed the highest digestibility values. Therefore, in the second phase, a Tilapia growth study was conducted using feeds containing from 0 to 25 % Spirulina sp. biomass to compare different parameters, such as weight gain (%), feed conversion ratio (FCR), and fish survival rate (%). A 5 % inclusion of Spirulina sp. biomass in the feed resulted in better Tilapia growth parameters compared to the controlled basal diet; however, higher inclusion levels of Spirulina in the feed negatively affected one or more growth parameters. However, based on the weight gain and FCR values, a 20 % inclusion of Spirulina biomass was considered for the Technoeconomic Analysis (TEA). Considering five potential cultivation scenarios, the cost of Spirulina production was determined to be 1.36/kg dry biomass. Integrating agricultural runoff and waste fertilizers into Spirulina sp. cultivation helped reduce the cost of biomass production. If 20 % locally-grown Spirulina sp. biomass is to be included in the fish feed to replace 15 % of the fishmeal and 5 % of the soybean meal, the overall fish feed cost would be reduced by 6 %.The authors would like to acknowledge the support of the Qatar National Research Fund (QNRF, a member of Qatar Foundation) for providing the funding (under grant MME01-0910-190028) for this study. The authors appreciate the support of TAMU graduate student Kequan Chen in the study on feed digestibility and fish growth
Continuing Professional Development and Knowledge Translation: Evidence and Perspectives to Enhance Clinical Practice in Qatar
No full textThis Master's thesis used a scoping review and qualitative interviews to gather in-depth data from CPD providers on how they design and plan programs to align with clinical needs. The scoping review included 17 studies. The review demonstrated that well-designed CPD programs can improve patient outcomes, but their effectiveness depends on the application and sustainability of learning in supportive contexts. This highlights the need for theory-based programs evaluated using a "knowledge-to-action" framework to link learning to practice. Several key findings emerged from the qualitative study, including that most participants relied on performance data, quality indicators, and staff and management feedback to identify learning needs. However, limited resources, complex administrative procedures, and limited time for safeguarding were major barriers. Effective programs incorporated simulations and workplace assessments. The study recommends developing a national CPD framework, streamlining accreditation, strengthening teacher training, and linking CPD assessments to measurable healthcare indicators to ensure sustainability and long-term impact on patient care. Future research should continue to examine how continuing professional development learning translates into tangible changes in clinical practice and patient outcomes
A NOVEL 2D DIPHOSPHATE NANOCRYSTALLINE HYDROGEL FOR SKIN INFECTIONS AND OTHER BIOMEDICAL APPLICATIONS
No full textAntimicrobial resistance, coupled with the limitations of polymer-based wound dressings, has intensified the need for sustainable, biocompatible topical materials capable of controlling infection while supporting tissue repair. This dissertation presents an entirely inorganic, polymer-free magnesium phosphate (MgP) nanosheet hydrogel as a thixotropic platform for dermal applications and demonstrates how rational ionic engineering can tune its physicochemical stability and biological performance. A pristine MgP nanosheet hydrogel was established as the core platform and characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, zeta potential analysis, and rheology, confirming a nanocrystalline two-dimensional architecture with shear-responsive gelation. Pristine MgP exhibited dose-dependent antimicrobial activity in vitro against Staphylococcus aureus, Escherichia coli, and Candida albicans, supported by ultrastructural evidence of microbial disruption. The formulation demonstrated excellent dermal compatibility in an OECD Test Guideline 439 reconstructed human epidermis model and in vivo topical tolerance studies. Functionally, pristine MgP significantly accelerated wound closure in non-infected full-thickness wounds but did not improve healing in Pseudomonas aeruginosa-infected wounds, indicating that bacterial burden limits its therapeutic efficacy. To further modulate antibacterial performance and stability, the MgP platform was systematically engineered through ionic incorporation. Zinc substitution preserved the nanosheet structure and enhanced antibacterial activity against S. aureus in vitro while maintaining dermal compatibility. In parallel, incorporation of pyrophosphate markedly improved colloidal and thermal stability and strengthened antibacterial activity against both S. aureus and P. aeruginosa. Building on this stabilized network, silver was introduced to generate MgP-pyrophosphate-Ag hydrogels with robust bactericidal activity against Gram-positive and Gram-negative pathogens, including P. aeruginosa, without inducing dermal irritation. Critically, silver-doped MgP-pyrophosphate hydrogels significantly restored wound closure in P. aeruginosa-infected wounds. Collectively, this work establishes a sustainable, polymer-free two-dimensional nanosheet hydrogel system whose physicochemical stability and biological function can be rationally tuned through ionic design, enabling an infection-responsive wound-care platform with potential biomedical and cosmetic applications
Burden of typhoid fever and antimicrobial resistance in India (2023): a modelling study
No full textBackgroundIndia is one of the countries with a high typhoid fever burden. In 2022, the National Technical Advisory Group on Immunisation recommended including the typhoid conjugate vaccine (TCV) in the Universal Immunisation Programme. In this study, we aimed to estimate the 2023 burden of typhoid fever and its antimicrobial resistance (AMR) to inform targeted vaccine introduction strategies. MethodsWe used a decision tree model to estimate typhoid cases, hospitalisations, complications, and deaths. Incidence and clinical parameters were derived from a multicentre Indian study, with state-wise AMR prevalence from a systematic review. Two co-primary and four alternative scenarios were presented to validate the robustness of the findings. FindingsWe estimated 4.9 million (95% UI: 4.4–5.6) typhoid cases and 7850 (4300–14,900) deaths in India in 2023. Of 730,000 (534,000–970,000) hospitalisations, 600,000 (435,000–799,000; 82%) were attributable to fluoroquinolone-resistant. Under primary scenario A, children <5 years accounted for 321,000 (235,000–427,000; 44.0%) hospitalisations and 2600 (1300–4800; 34.0%) deaths. Under primary scenario B, 5–9 years of age accounted for 265,000 (135,000–278,000; 36.0%) hospitalisations and 2900 (1500–5300; 36.0%) deaths. Delhi, Maharashtra, and Karnataka together accounted for 29% of the national burden and had the highest rates of fluoroquinolone-resistant cases and deaths among the ten highest-burden states. Deaths linked to fluoroquinolone-resistance, multidrug resistance, third-generation cephalosporins, and azithromycin resistance were 4700 (1800–10,200), 122 (45–294), 183 (69–431), and 183 (68–432), respectively. InterpretationFluoroquinolone-resistance drives a large share of typhoid-related hospitalisations and deaths, especially in children under five and in high-burden states of India. Targeted TCV introduction, with broader age coverage among children, would maximise impact. FundingWISE programme; Vaccine Impact Modelling Consortium; Japan Agency for Medical Research and Development.VVM is supported by the World-leading Innovative & Smart Education (WISE) programme at Nagasaki University (no. 672009). KA is supported by the Vaccine Impact Modelling Consortium (INV-034281) funded by the Gates Foundation. KA and WJE are supported by the Japan Agency for Medical Research and Development (JP223fa627004). The contents of this article are solely the responsibility of the authors and do not represent the official views of their affiliated organisations. Where authors are identified as personnel of the WHO, the authors alone are responsible for the views expressed in this article, and they do not necessarily represent the decisions, policy, or views of the WHO
Establishing the legitimacy of possession as a reason for acquiring ownership: A comparative study
No full textيعتبر موضوع الحيازة من المواضيع المثيرة للجدل والنزاع، حيث يعتبرها البعض بمثابة غصب أموال الغير والاعتداء عليها. إلا أن عند البحث المكثف في موضوع الحيازة وجدت الكثير من الآراء الفقهية والأسانيد التي تبرر مشروعية الحيازة كسبب مكسب للملكية، خصوصاً لدى فقهاء المالكية الذين أفردوا مساحة واسعة في دراسة موضوع الحيازة وتأصيل مشروعية الأخذ بهذا النظام لعدة أحاديث وأسانيد، ثم يليهم باقي المذاهب الفقهية الذين أخذوا بمشروعية الحيازة لكن بأسانيد تختلف عن المذهب المالكي. إن الاعتراف بمشروعية الحيازة من شأنه أن يحافظ على استقرار المعاملات ومحافظة على النظام الاقتصادي والاجتماعي في المجتمع، ويعتبر حماية للوضع الظاهر وتشجيع الأفراد على حماية حقوقهم وإعمارها. وتعود نشأة نظام الحيازة للقانون الروماني ثم القانون المدني الفرنسي الذي وضع الصورة النهائية للحيازة، حتى وصل الأمر للقوانين المدنية الحالية، ومن ضمن هذه القوانين الحديثة القانون المدني القطري الذي كان لا يعترف بالقانون السابق بهذا النظام، أصبح الآن يأخذ بنظام الحيازة مع صدور القانون الجديد رقم 22 لسنة 2004 ونظم له نصوص خاصة ضمن إطار معين.Is considered one of the most controversial and disputed topics, as some regard it as a form of usurping others’ property and encroaching upon it. However, upon in-depth research into the subject of possession, I found numerous jurisprudential opinions and legal foundations that justify the legitimacy of possession as a means of acquiring ownership—especially among Maliki jurists, who devoted significant attention to the study of possession and its legitimacy, basing their views on various Hadiths and legal proofs. They were followed by other Islamic schools of thought, which also recognized the legitimacy of possession, though based on different sources than the Maliki school. Acknowledging the legitimacy of possession contributes to the stability of transactions and helps maintain the economic and social order within society. It also serves to protect apparent legal status and encourages individuals to safeguard and develop their rights. The concept of possession originated in Roman law and was later developed in the French Civil Code, which shaped its modern form. This influence extended to contemporary civil laws, including the Qatari Civil Code. Although the previous Qatari legislation did not recognize this system, the new Civil Code No. 22 of 2004 has adopted the system of possession, organizing it through specific provisions within a defined framework
The Theory of Maslaha in Maqaşidic and Utilitarian Thoughts: A Comparative Study
No full textإن كلا من الفكرين المقاصدي والنفعي يولي اهتماما بالغا بالمصلحة؛ لكونها روح الأفعال والتصرفات التي يقوم بها الناس في نظرهما. وتهدف هذه الدراسة إلى البحث عن نظرية المصلحة لدى الفكرين من جوانبها المختلفة لاكتشاف مدى الموضوعية أو التحيز، والاتفاق أو الاختلاف بينهما، ومن ثم مدى تميز إحداهما على الأخرى، وذلك بالاعتماد على المنهج الوصفي التحليلي في جمع البيانات، وتفسيرها، وربطها ببعضها للوصول إلى نتائج دقيقة، وعلى المنهج التاريخي لرصد الأحداث الماضية وأثرها في واقع النظريتين؛ للوصول إلى تفسيرات مناسبة لتلك الأحداث والأفكار في ضوء سياقها التاريخي، كما استخدم الباحث أداة الاستقراء؛ لتتبع الأفكار المتعلقة بالموضوع للوصول إلى قواعد كلية وضوابط عامة. وقد توصلت الدراسة إلى أن نظرية المصلحة في الفكر المقاصدي تتسم بالدقة العلمية والموضوعية المنطقية والاتساق الفكري بين قضاياها؛ لانطلاقها من إطار مركزي متعال شامل يتمثل في مركزية التوحيد. في حين أن نظرية المصلحة في الفكر النفعي تتصف بالتحيز الثقافي، والنسبية الشديدة، وعدم التماسك بين قضاياها؛ لانطلاقها من إطار مركزي غير متعال ونسبي يتمثل في مركزية الإنسان المطلقة.The concept of Maslaha holds a key position in both Maqäşidic and utilitarian thoughts, as they regard the Maslaha as the fundamental spirit of human actions and behaviors. The study aims to investigate the theory of Maslaha within these two-intellectual schools of thought from multiple dimensions, in order to explore the extent of objectivity or bias, and convergence or divergence between them, and thereby to determine whether one of them establishes superiority over the other. The research adopts a descriptive-analytical method to collate, critique, interpret, and interrelate data to arrive at precise conclusions; an inductive tool to trace dispersed ideas related to the subject in order to formulate general rules and comprehensive principles; and a historical method to observe past events and ideas to find out their impact on these two theories, thereby providing proper interpretations of those events and ideas within their historical contexts. The dissertation concludes that the theory of Maslaha in Maqasidic thought is characterized by scientific precision, logical objectivity, and intellectual coherence, as it derives from a transcendent and comprehensive central domain, namely the absolute centrality of the Oneness of Allah. While the theory of Maşlaha in utilitarian thought is marked by cultural bias, radical relativism, and internal inconsistency, as it stems from a non-transcendent and non-comprehensive central domain, namely the absolute centrality of the human being
Population Genetics of Whale Shark (Rhincodon typus) in Qatar
No full textThe whale shark (Rhincodon typus), the largest extant fish, listed as endangered on the
IUCN Red list, forms one of its most significant feeding aggregations around the Al Shaheen
oil field in Qatar. Despite its ecological importance, limited information exists on the genetic
diversity and population structure of these aggregations in Qatar. This study used mitochondrial
DNA (mtDNA) markers to assess the genetic diversity, population structure, and connectivity
of whale sharks in Qatari waters with global populations. A total of 108 tissue samples were
collected during the aggregation seasons of 2023–2024, which yielding 88 high-quality
sequences. The net sequence length obtained for the consensus sequences was 1,303 bp after
cleaning, trimming, and alignment. Analysis revealed high haplotype diversity (Hd = 0.977)
and nucleotide diversity (π = 0.288), with 68 distinct haplotypes, higher than previously
reported in the region. Phylogenetic analyses revealed five unique lineages, with strong genetic
connectivity across several geographic regions worldwide. Also, one unique lineage, though
not drastically different from other clades, was found which was not represented in the global
database. This genetic divergence may result from mutations, varying environmental pressures,
or distinct evolutionary histories. Alternatively, this clad could arise from the fact that the
incomplete global database of whale shark sequences, with poor representation from certain
regions. Overall, our findings support the hypothesis of a broadly connected Indo-Pacific
population and emphasize Qatar’s role as a key genetic reservoir. Continued genetic monitoring
using broader regions is recommended to support conservation of this endangered species. The
study also highlights the significance of Qatar’s habitats and conservation initiatives in
supporting the long-term survival of the whale shark’s global populations, as aggregations in
Qatar represent a large population converging from diverse geographic regions and genetic
lineages
Sustainable Groundwater Treatment: Enhancing NF and UF Membrane Efficiency with Agro-Waste-Derived Crystalline Nanocellulose
No full textQatar is located on the eastern edge of the Arabian Peninsula and is characterized by an arid climate with minimal rainfall. In the absence of surface water resources, groundwater represents the country’s primary natural freshwater supply, with approximately 92% of extracted groundwater utilized for agricultural purposes. Prolonged overextraction has contributed to the deterioration of groundwater quality, with elevated concentrations of trace elements such as molybdenum (Mo), boron (B), and lithium (Li) reported in several wells across Qatar. Although membrane filtration is widely applied for groundwater treatment, its performance is often hindered by membrane fouling, underscoring the need for surface modification strategies to enhance treatment efficiency.
This study evaluated the physicochemical quality of groundwater collected from ten farms in Qatar and employed spatial interpolation analysis using ArcGIS to assess contaminant distribution. The results revealed that Mo, B, and Li, along with other water quality parameters, exceeded guideline limits established by the World Health Organization (WHO), Gulf Standardization Organization (GSO), Qatar drinking water standards, and United States Environmental Protection Agency (US-EPA) health advisories. To address these challenges in a sustainable manner, crystalline nanocellulose (CNC) was extracted from date-pit agro-waste and utilized to modify ultrafiltration (UF) and nanofiltration (NF) membranes.
X-ray diffraction (XRD) analysis confirmed the crystalline structure of CNC, with characteristic peaks at 15.5° and 22.5° and a crystallinity index of 39.5%. Fourier transform infrared spectroscopy (FTIR) verified the presence of functional groups, while atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses confirmed successful CNC coating on the membrane surfaces. The CNC-modified NF membrane (NF-CNC) exhibited a reduction in surface roughness from 37.8 to 19.8 nm, whereas the CNC-modified UF membrane (UF-CNC) showed an increase in roughness (35.56 to 44.50 nm) accompanied by improved hydrophilicity following surface modification.
Filtration experiments conducted at operating pressures of 5 bar for NF and 2 bar for UF demonstrated that UF-CNC outperformed all other membranes, achieving greater than 90% rejection of B, Li, and Mo. These results were statistically validated using Tukey’s post-hoc test. The dominant removal mechanisms were attributed to Donnan exclusion for Mo, hydration-layer interactions and electrostatic interaction for Li, and hydrogen bonding for B, indicating the role of adsorptive membrane filtration. When applied to real groundwater samples, UF-CNC successfully reduced Li and B concentrations to permissible levels of Qatar while simultaneously lowering additional contaminants and maintaining stable performance with minimal fouling.
Overall, this study demonstrates the dual functionality of CNC-modified membranes in enhancing pollutant removal efficiency while sustaining membrane performance, highlighting their potential for sustainable groundwater treatment in arid regions
ENHANCING THE SAFETY OF MOTORCYCLE FOOD DELIVERY RIDERS IN QATAR: A MULTIDIMENSIONAL ASSESSMENT
No full textThe rapid growth of online food delivery services has created a new vulnerable class of road users: Motorcycle Food Delivery Riders (MFDRs). This thesis presents a comprehensive investigation of MFDR traffic safety in Qatar by examining the problem through the Safe Systems Approach (SSA) and the Knowledge - Attitude - Practice (KAP) framework to evaluate the perspectives of riders, other road users, and the work system. The research utilised cross-sectional surveys, advanced statistical modelling, and mediation analysis to examine the complex interactions among factors associated with MFDR traffic safety outcomes. The findings identify key safety priorities to enhance MFDR safety in Qatar. While helmet use was high, the adoption of other protective gear was low, primarily due to climatic factors and a lack of awareness of safety standards. Moreover, workrelated riders followed pre-ride safety checks but engaged in more risky riding, likely due to occupational pressure. Furthermore, perceived safety and prior crash experience were associated more with standard gear use than demographics. From the driver's perspective, MFDRs were frequently observed engaging in high-risk behaviours (tailgating/weaving). Moreover, drivers with no motorcycle riding experience and those who underestimated the inherent difficulties of motorcycle riding were at a higher risk of crashing with MFDRs, highlighting a gap in shared road user understanding. Statistical modelling revealed that the critical factors associated with traffic safety outcomes were occupational (trip-based payment, high daily trip counts, and high annual distance travelled), making demographic factors largely insignificant. Mediation analysis revealed that work characteristics directly influence the pathways from knowledge and attitude to risky riding practices. For fatigue management, the path operates through an indirect mediation: greater knowledge promotes more risk-averse attitudes, which in turn reduce risky practices. The thesis concludes that countermeasures, which focus on individual rider are insufficient. An integrated intervention strategy by: regulatory reform of MFDR payment/dispatch models; occupation-specific training for riders and mandatory awareness for drivers; dissemination of knowledge related to standard safety gears and promotion of climate-adaptive protective gear; and data-driven safety strategies are necessary. Moreover, the primary responsibility for change must shift from the individual rider to all authorities that design the work system, thereby enhancing occupational and traffic safety