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Analysis of Anticholinergic Medicine Effect on Cognitive and Functional Decline Among Older Adults
No full textThe association between the long-term effect of anticholinergics and cognitive-functional decline in older adults is not clear. If such an association exists, it would be important to account for the anticholinergic burden whenever we evaluate the risk factors of cognitive-functional decline in older adults. Adopting an efficient and practical method to assess anticholinergic burden is crucial in estimating such an association. Thus, this study had two objectives: (1) to validate an assessment approach in quantifying anticholinergic burden; and (2) to evaluate the impact of the anticholinergic burden on the cognitive-functional decline in older adults.
The study used data from the S. AGES (Sujets Ages, elderly subjects) sub-cohort and included 983 community older adults aged 64-97 years old, followed up between 2009 and 2013. The Anticholinergic and Sedative Burden Catalog (ACSBC), a recently developed anticholinergic catalogue, and the Anticholinergic Cognitive Burden Scale (ACB), an old validated practical scale, were used to calculate the average daily anticholinergic burden scores throughout the follow-up period. Mini Mental State Examination (MMSE), Instrumental Activities of Daily Living (IADLs), and Activities of Daily Living (ADLs) measured at the time of inclusion month (M0) and every 12 months (M12, M24, and M36) were used to evaluate cognitive and functional decline. The study also combined the MMSE with BADLs, the MMSE with IADLs, and the MMSE with ADLs (BADLs & IADLs) to create three integrated cognitive-functional subscales.
The first step was to check the external nomological validity by estimating the level of correlation between the average daily ACSBC and ACB scores. Then, the analysis regressed the two average daily anticholinergic burden scores (ACSBC and ACB) in mixed models over time with cognitive and functional outcomes and compared their adjusted Ξ² estimates. The second step of the analysis focused on modeling each cognitive-functional decline combined subscale with the average daily anticholinergic burden scores (ACSBC and ACB).
The study showed that quantifying anticholinergic burden using a scale or a catalogue provided parallel results across the mixed models. Additionally, results showed that the average daily anticholinergic burden is associated with cognitive and functional decline, particularly when both outcomes are combined, reflecting the nature of aging that is accompanied by concurrent decline in cognitive and functional activities.
Results from this study serve the community and help geriatricians to manage the pharmacotherapy regimen provided to older persons while possibly lowering the expense of their treatment due to unintended side effects. In addition, the results of this study provide additional evidence to account for the anticholinergic burden when assessing the risks of cognitive-functional decline
Liability Sharing or Transfer between Architecture and Engineering Design Professionals and Relevant Stakeholders
No full textA main concern for Architecture and Engineering (A/E) professionals is their high exposure to professional liabilities (PLs), which vary depending on their roles and responsibilities. There stems the significance of this research, which aims to provide a clear and comprehensive mapping of how such PLs may be transferred, in part or in full, to other project stakeholders. To this end, a multi-step methodology is adopted, starting with literature and case law reviews, to identify parties potentially implicated in liability splits and to delineate the instances under which such transfers may occur.
Contractors are at the forefront of parties who may share PLs traditionally assumed by A/E professionals. Module 1 investigates this allocation under prevalent project delivery approaches, including Design-Bid-Build (DBB), Construction Management at-Risk (CMAR), Design-Build (DB), and Integrated Project Delivery (IPD). The methodology involved: 1) a literature review and case law analysis of relevant judicial cases and legal principles to identify the instances where contractors may assume PLs, 2) the identification and synthesis of liability allocation classes (LACs) to systematically classify the rationales underlying the various liability sharing instances, 3) the development of qualitative liability split models (LSMs) to evaluate the full spectrum of possibilities for the PL apportionments, 4) the conceptualization of several constructs that delineate the potential sharing of PLs under the relevant PDMs, based on the proposed LACs and LSMs, and 5) a theorized relative apportionment of liabilities to offer an insightful comparison of potential liability splits both within and across PDMs. The findings revealed that the extent of liability sharing varies both within and across PDMs. Under DBB, contractors assumed PLs, fully or partially, in 16 of 19 identified schemes - an important shift from the traditional view that PLs are mainly assumed by A/E professionals or owners. In alternative PDMs, contractors were found to potentially share PLs across all schemes. Greater integration and collaboration within a PDM result in an increased contractor involvement in design and, consequently, a higher exposure to PLs.
Module 2 explores potential liability sharing between A/E designers and their reviewers. While reviews aim to reduce errors and risks, they can also blur liability boundaries, a gap this research addresses by: 1) analyzing relevant literature, legal principles, statutes, and standards, 2) synthesizing internal and external review types, highlighting their key attributes and objectives, 3) identifying the instances where reviewers may assume PLs under two prevalent review types, namely external third-party technical peer reviews and value engineering, 4) proposing liability allocation classes related to reviews (RLACs) and qualitative liability split models (RLSMs), and 5) elaborating constructs that delineate the potential PL sharing for the two review types investigated. For third-party technical peer reviews, findings suggest that reviews should not relieve designers from their design obligations and associated liabilities. However, reviewers may assume PLs if they operate beyond their review scope - by performing new original work or implementing their recommendations. Value engineers may also assume PLs, with their extent increasing as involvement deepens and proposal complexity and innovation grows.
Module 3 investigates knowledge exchanges (KE) among design professionals, intra-organization, inter-organizations, and through knowledge management systems (KMS). Two KE approaches are identified: project-specific exchanges that end with the project, and continuous sharing enabled by KMS, which retains and updates knowledge for future use. The methodology includes: 1) a real case study of a large, global consulting group to explore KE dynamics, 2) synthesis of KE dimensions and drivers, 3) classification of factors influencing KMS development in the A/E environment, 4) elaboration of a framework for an effective A/E KMS, and 5) a methodology to optimize KE. This module paves the way for future research on potential PL sharing in KE contexts.
This research study addresses the critical - yet underexplored - topic of liability sharing between A/E professionals and relevant stakeholders, offering a comprehensive perspective to support more informed risk management and reduce exposure to design-related professional liabilities
Al-based Metal Organic Framework for Efficient Conversion of Glucose into 5- HydroxyMethylFurfural: Effect of Functionalized Linker of Catalysts and Reaction Parameters on HMF Yield
No full textThere are many investigations into developing modern technologies for producing energy from renewable biomasses due to the limitation of fossil fuels. HMF has a wide range of applications that can be used to produce bio-based fuels. It also has more reactive characteristics than other furans due to its hydroxyl group. HMF can be produced from glucose or fructose in an acid-catalyzed process. Many studies have been made in this field, and they used homogeneous and heterogeneous catalysts; however, few used MOFs as support catalysts, which showed excellent characteristics in producing HMF and reported outstanding results. This project aims to test aluminum-based MOF, which has more substantial acidity sites than Zr-based ones, which will increase the rate of isomerization/dehydration reaction to form 5-HMF. Moreover, reaction conditions like temperature, catalyst regeneration and catalyst loading will be investigated in this study. Al-based metal-organic frameworks, Mil-53 NH2, and Mil-53 NHRSO3H with different concentrations of TFA will be synthesized, TFA will be used to form defects in the Mofs and study its effects on the reaction yield and mechanism. The dehydration reaction of glucose will be launched using a reflux reaction system to produce 5-HMF. The Mofs will be characterized and analyzed to ensure their optimality, and the products will be measured and analyzed using HPLC to calculate the yield of 5-HMF production. The highest yield was reached by Nd-Mil-53 NHrSO3H without defections of 59%, while 3d-Mil-53 NH2 had the lowest yield of 49%; so, the concentration of TFA affects negatively on the yield of the reaction, where the yield decreases when the concentration of TFA acid increases for both catalysts. In addition, by varying the reaction temperature and catalyst loading, results show the optimal catalyst loading was 50 grams, and the optimal temperature was 140Β°C
Investigation of Spin Pumping in Yttrium Iron Garnet/Tungsten-Titanium (YIG/W-Ti) Bilayers
No full textThe development of energy-efficient spintronic technologies hinges on the ability to generate and manipulate pure spin currents with minimal energy loss. Among the mechanisms to achieve this, spin pumpingβwherein a precessing ferromagnet injects spin current into an adjacent non-magnetic materialβhas emerged as a powerful approach. The efficiency of this process is governed by the spin mixing conductance at the ferromagnet/non-magnet (FM/NM) interface and is strongly influenced by the choice of materials, their structural phases, and interfacial quality. In this context, Yttrium Iron Garnet (YIG) stands out as a magnetic insulator with ultra-low Gilbert damping, making it ideal for studying spin dynamics. However, optimizing the non-magneticΒ layer for efficient spin current absorption remains an ongoing challenge. This thesis investigates the spin pumping behavior in bilayers composed of YIG and a Tungsten-Titanium (WβTi) alloy, a material system that has received limited attention despite the potential of tungsten-based alloys in spintronic applications due to their strong spin-orbit coupling. YIG thin films were grown using pulsed laser deposition and subsequently capped with WβTi layers of varying thicknesses (1β10 nm). Structural and compositional characterizations were performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and profilometry.Β Magnetodynamic properties such as the Gilbert damping and effectiveΒ magnetization were extracted via broadband ferromagnetic resonance (FMR) measurements. Our resultsΒ reveal a pronounced enhancement in magnetic damping in YIG/W-Ti bilayers compared to bare YIG films, confirming the observation of spin pumping. By systematically varying both YIG and WβTi thicknesses, we quantified the spin mixing conductance and uncovered two distinct regimes of spin transport. At lower WβTi thicknesses, a higher spin mixing conductance is observed, attributed to the formation of the Ξ²-phase of WβTi, known for its high spin-orbit coupling. In contrast, thicker WβTi layers exhibit a transition to the Ξ±-phase, associated with reduced spin current transmission. This work sheds light on the structural-phase-dependent nature of spin pumping in WβTi alloys and demonstrates the potential of engineering FM/NM interfaces to optimize spin current generation and transfer. These insights provide valuable guidance for the design of next-generation spintronic devices based on magnetic insulator/heavy metal heterostructures
Parallel Bidirectional A* Search for GPU-Accelerated Pathfinding
No full textPathfinding algorithms, such as A*, are fundamental in solving graph traversal problems efficiently. A* is a point-to-point shortest path finding algorithm meaning, given a weighted graph, a source node and a goal node, the algorithm finds the shortest path (with respect to the given weights) from source to goal. Additionally, the bidirectional A* algorithm is a variation of the A* algorithm where the search is explored in both directions from the starting and ending nodes. While A* guarantees optimal solutions, its sequential nature poses challenges in exploiting the computational power of modern parallel architectures, particularly GPUs. This paper introduces a bidirectional bucket-based parallel A* algorithm (BBA*) tailored for GPU architectures, offering significant performance improvements over existing implementations. Our approach incorporates a bidirectional strategy, enabling the algorithm to operate simultaneously from the start and goal nodes, inherently increasing parallelism. By leveraging a bucket-based priority queue structure, we mitigate contention issues typically encountered with traditional heap-based designs, ensuring efficient workload distribution among GPU threads. Extensive experiments were conducted on grids with diverse sizes and obstacle configurations (i.e mazes, random obstacles, etc.) to evaluate the algorithm's performance in terms of time efficiency and the number of nodes explored. Results demonstrate that our implementation outperforms state-of-the-art parallel GPU implementations (like GA* and BGPQ A*). The proposed algorithm is particularly effective in complex grid scenarios, where its parallel processing capabilities significantly reduce execution time and the total number of nodes explored while maintaining optimality. BBA* can be up to 50 times faster than sequential CPU baselines and up to 40 times faster than the state-of-the-art GPU implementations
Biaxial Ellipsoid in Discrete Gravity
Get PDFWe study the biaxial ellipsoid manifold in the context of discrete gravity. The metric of the ellipsoid is transformed into that of a lattice, labeling the cells using integers which become coordinates in the continuous limit. The scalar curvature in the discrete gravity framework is computed using derived explicit solutions of spin connections for this setting and is shown to successfully recover the scalar curvature in the continuous case as the number of cells is increased. Likewise, the spin connections are numerically computed in the discrete framework by solving a nonlinear system of equations obtained through the torsion-free condition. They are shown to converge to the continuous spin connections as the number of cells is increased
Political Partiesβ Positions on Women Quota in the Lebanese Parliament: Lessons from the Iraqi and Algerian Cases
Get PDFThe persistent underrepresentation of women in Lebanese politics has spurred discussions on women quota as a potential solution. This thesis examines the positions of Lebanese political parties on the adoption of women quota in parliament through five political parties taken as case studies and interviews with political and civil society actors. Also, this thesis followed a comparative approach with two Arab countries that have adopted women quota to analyze what lessons Lebanon can take from the experience of these two countries. Key themes emerging from the interviews include the influence of lobbying, the effectiveness of quotas in a patriarchal context, the need for women to expand their focus beyond issues of women and children, and the enriching experience of working within a political party structure. The comparison with the two Arab countries highlights the importance of bottom-up mobilization and the role of womenβs organizations. The findings emphasize the necessity of uniting efforts between women in political parties and external womenβs organizations and gender activists to create a comprehensive, sustainable approach to enhancing womenβs participation in the Lebanese parliament
A Digital Twin for Methane Catalytic Cracking in a Fluidized Bed Reactor
Get PDFMethane catalytic cracking is a promising clean alternative for hydrogen production, generating only hydrogen and solid carbon, thereby minimizing environmental impact. Unlike conventional methods, this technology enables hydrogen production without additional hydrocarbon emissions. However, an efficient catalyst is required to facilitate the reaction at moderate operating temperatures (500β700Β°C), reducing operational costs and allowing for potential integration with solar energy.
To enhance both mass and heat transfer, a bubbling fluidized bed reactor (FBR) was employed to conduct the methane cracking process. This study presents the development of a three-phase FBR model using a highly active zinc-promoted nickel catalyst (50Ni-5Zn/USY) on ultra-stable Y (USY) zeolite. The model was designed to predict the reactorβs performance under different operating conditions, providing essential insights for scaling up the process for industrial applications.
To accurately simulate the system, both kinetic and mechanistic models were developed:
The mechanistic model describes the hydrodynamic properties of the fluidized bed, bubble characteristics, and the mass transfer of methane and hydrogen across the three phases. The kinetic model was formulated to characterize the reaction rate. The most suitable kinetic model suggests that the reaction follows a dissociative adsorption mechanism, with the first hydrogen abstraction from methane identified as the rate-determining step. This was validated against experimental data, where parameter estimation was carried out to predict the Arrhenius rate coefficients.
The findings of this model significantly enhance the understanding of methane catalytic cracking, providing key insights for optimizing process conditions and demonstrating the feasibility of scaling up this technology for industrial hydrogen production with minimal environmental impact
Advancing Cartilage Regeneration: Hypoxia and Alginate Sulfate Preserve Chondrocyte Phenotype by Promoting ECM Production and Reducing Inflammation
No full textArticular cartilage's limited regenerative capacity poses challenges in treating degenerative diseases like osteoarthritis (OA). Autologous chondrocyte transplantation (ACT) offers potential for cartilage repair by reintroducing healthy chondrocytes into damaged tissue. However, chondrocytes often lose their phenotype during expansion on tissue culture plastic (TCP), limiting their regenerative efficacy. This study explores the synergistic effects of basic fibroblast growth factor (FGF-2) and alginate sulfate films under hypoxic conditions to optimize in vitro conditions for preserving the chondrocyte phenotype during expansion. Results showed that alginate sulfate significantly reduces proliferation, prioritizing matrix production over cell division compared to alginate (p < 0.05). It also increases total collagen content (collagen types 1 and 2) under hypoxia (p < 0.05) and reduces catabolic factors such as IL-1Ξ², IL-6, and MMP-13, indicating its role in maintaining cartilage integrity. Conversely, FGF-2 significantly enhances proliferation, nearly doubling cell numbers (p < 0.05), and induces a fibroblastic shift under hypoxia by increasing collagen type I, decreasing collagen type II, and elevating catabolic factors (p < 0.05). Hypoxia reduced proliferation by nearly half (p < 0.05) but promoted a chondrogenic phenotype. It dedifferentiated late-passaged chondrocytes (P3), making them morphologically resemble early-passaged chondrocytes (P1). Hypoxia also enhanced total collagen content and suppressed inflammatory factors when combined with alginate sulfate (p < 0.05), indicating a protective effect on chondrocyte phenotype. These findings suggest that the optimal condition for chondrocyte expansion while maintaining phenotype is alginate sulfate under hypoxic conditions without FGF-2. This approach balances collagen production, enhances cartilage-specific extracellular matrix (ECM), reduces inflammation, and preserves cellular morphology, making it a promising strategy for cartilage tissue engineering
Addressing Thermal Comfort Indoors and Outdoors: Novel Ventilation Systems for Safety and Comfort in Indoor Spaces and Mitigating Outdoor Thermal Discomfort in the Arab Region
No full textStudents spend most of their academic life indoors, inside classrooms. These spaces should be carefully designed to maintain acceptable indoor environmental quality (IEQ) and boost the studentsβ cognitive performance and academic outcomes. Achieving acceptable IEQ levels faces many challenges which should be addressed. In fact, classrooms present a high occupancy density which creates a high thermal load and poor indoor air quality affecting thus the thermal comfort and health of the students. In addition, such spaces are characterized by close seating arrangement which accentuates the risk of cross-infection by pathogens released from an infected student. Therefore, considerable efforts should be made to come up with adequate techniques to provide acceptable thermal comfort and air quality levels and confine the spread of contagious pathogens inside classrooms. This should be achieved without compromising energy efficiency. The remainder of the student time is allocated to engaging in outdoor activities. In this matter, understanding outdoor thermal discomfort is crucial for pedestrians, as well as for shaping environmental health, urban planning, and climate adaptation strategies. As global temperatures are increasing due to climate change, cities worldwide are experiencing more frequent and intense heat waves that threaten public health. Identifying the factors contributing to outdoor thermal discomfort is necessary for urban planners, architects, and policymakers to create sustainable, resilient cities that provide comfortable outdoor environments. This work addresses human thermal comfort both indoors and outdoors, hence it is divided into two parts.
In the first part, this work proposes novel hybrid ventilation strategies with minimal energy consumption to enhance the IEQ inside classroom spaces. The first proposed ventilation strategy is the pulsating jet ventilation (PJV) system that imitates the transient behavior of natural wind by supplying the air in an ON-OFF manner inside the classroom. This ventilation system enhances the convective heat transfer between the human body and its surroundings and creates elevated thermal comfort level at elevated room temperature. In addition, with a careful selection of the system parameters such as the supply airflow rate and intermittency period, the PJV is able to maintain the CO2 at acceptable levels. However, the intermittent aspect of the PJV creates high turbulence levels inside the classroom which aggravates the spread of infectious pathogens released by infected students and elevates the cross-infection risks. The second proposed ventilation system is the downward piston ventilation (DPV) which is highly recommended in hospital rooms to contain the spread of contaminants and ensure acceptable air quality levels. This system is based on the βpush-pullβ principle and supplies a high flowrate of clean air in a downward parallel manner from the ceiling level. However, this system requires an elevated energy bill to be able to supply high airflow rates at cool temperatures into the classroom. It was noticed that each of the suggested ventilation systems has its advantages, but it also presents several drawbacks, necessitating the use of "add-on" devices to achieve comprehensive functionality. The most practical and energy-efficient βadd-onβ devices are the portable air cleaners (PACs), the upper-room ultraviolet germicidal irradiation (UR-UVGI) lamps, and the localized exhaust (LE) devices. These devices are proposed to assist the ventilation systems (PJV and DPV), and their effectiveness is tested using computational fluid dynamic simulations by developing 3D models of the classroom and its different components in ANSYS software. The developed models were validated experimentally, and used to simulate the velocity fields, temperature fields, contaminants spread, and potential cross-infection risks inside the classroom. In the second part, this work examines outdoor thermal comfort in the Eastern Mediterranean and Middle East region spanning from 10 Β°N to 50 Β°N in latitude and from 20 Β°E to 60 Β°E in longitude for an overall period of 43 years ranging from 1980 to 2023 using ERA5 reanalysis data. It explores spatiotemporal variations in weather parameters (i.e., dry bulb temperature, relative humidity, and wind speed) to identify the year during which a climatic shift occurs and analyze its severity in each city of the studied domain. Then, the comfort levels are plotted across the region using five different thermal comfort indices: the effective temperature (ET), the heat index (HI), the humidex (HD), the wet bulb globe temperature (WBGT), and the temperature humidity index (THI). The number of discomfort hours per summer day and their trend of variations are calculated for major cities across the region and for each year of the studied period. In addition, the relation between discomfort days and El NiΓ±o southern oscillation events is investigated throughout the 43 years