AUB ScholarWorks (American Univ. of Beirut)
Not a member yet
33634 research outputs found
Sort by
A temporal in vivo catalog of chromatin accessibility and expression profiles in pineoblastoma reveals a prevalent role for repressor elements
No full textPediatric pineoblastomas (PBs) are rare and aggressive tumors of grade IV histology. Although some oncogenic drivers are characterized, including germline mutations in RB1 and DICER1, the role of epigenetic deregulation and cis-regulatory regions in PB pathogenesis and progression is largely unknown. Here, we generated genome-wide gene expression, chromatin accessibility, and H3K27ac profiles covering key time points of PB initiation and progression from pineal tissues of a mouse model of CCND1-driven PB. We identified PB-specific enhancers and super-enhancers, and found that in some cases, the accessible genome dynamics precede transcriptomic changes, a characteristic that is underexplored in tumor progression. During progression of PB, newly acquired open chromatin regions lacking H3K27ac signal become enriched for repressive state elements and harbor motifs of repressor transcription factors like HINFP, GLI2, and YY1. Copy number variant analysis identified deletion events specific to the tumorigenic stage, affecting, among others, the histone gene cluster and Gas1, the growth arrest specific gene. Gene set enrichment analysis and gene expression signatures positioned the model used here close to human PB samples, showing the potential of our findings for exploring new avenues in PB management and therapy. Overall, this study reports the first temporal and in vivo cis-regulatory, expression, and accessibility maps in PB. © 2023 Idriss et al
Personalized ventilation with embedded air treatment system for simultaneous cooling and sorption-based carbon and humidity capture
Get PDFThis study presents a novel approach to address thermal comfort and air quality challenges in built environments using personalized ventilation (PV). Conventional techniques rely on delivering clean, cool and dehumidified outdoor air occupant microclimate. In contrast, this research extends the use of these conventional PV systems to deliver decarbonized and dehumidified air using a localized indoor air treatment system. The system meets air quality requirements of the occupant while minimizing its size and energy consumption through the innovative PV airflow supply from co-flow air terminal. Hence, a compact multi-functional personalized ventilation (MFPV) device, employing an adsorbent system for simultaneous CO2 and H2O capture from indoor air, is developed and its feasibility is tested. The device utilizes thermoelectric cooling (TEC) to cool the supply air and regenerate the adsorbent. Mathematical models are developed for the system to predict performance an appropriate control strategy. The models are verified experimentally using a constructed prototype of the device and used to optimize the design and operation via a four-way valve and switching the TEC current polarity such that the flow was periodically guided to cooling and regeneration TEC sides. The optimal operation was achieved with a purge-to-supply flowrate of 40 %, adsorbent mass of 125.3 g of Lewatit® VP OC 1065, along with two TEC modules with a power of 7.2.8 Wh and a cycle time of 7.5 min. The MFPV resulted in 22 % and 58 % energy savings compared to conventional co-flow and single flow PV system using treated outdoor air, respectively. © 2023 Elsevier Lt
RIS-Aided mmWave MIMO Channel Estimation Using Deep Learning and Compressive Sensing
Get PDFReconfigurable intelligent surface (RIS) assisted wireless systems require accurate channel state information (CSI) to control wireless channels and improve both the bandwidth and energy efficiency. However, CSI acquisition is non-trivial for two reasons: 1) the passive nature of RIS does not allow transceiving and processing pilot signals, and 2) the dimensions of the cascaded channel between transceivers increases with the large number of RIS elements, which yields high training overhead and computational complexity. While prior art has mainly focused on frequency-flat channel estimation, this paper proposes novel data-driven and compressive sensing based approaches for estimating both frequency-flat and frequency-selective cascaded channels of RIS-assisted multi-user millimeter-wave large multiple input multiple output (MIMO) systems with limited training overhead. The proposed methods exploit the common sparsity property among the different subcarriers and the double-structured sparsity property of the angular cascaded channel matrices as different angular cascaded channels observed by different users share completely common non-zero rows and user-specific column supports. The proposed data-driven cascaded channel estimation approaches use denoising neural networks to accurately detect channel supports. Alternatively, when data-training capabilities are not available, the compressive sensing based orthogonal matching pursuit (OMP) approach relies on sparsity properties and applies simultaneous OMP to detect the channel supports. Simulation results show that the pilot overhead required by the proposed scheme is lower than existing schemes. When compared to other OMP approaches that achieve an NMSE gap of 5 to 6 dB with respect to the Oracle least square lower bound, the proposed algorithms reduce the lower bound gap to only 1 dB, while reducing complexity by more than two orders of magnitude. © 2002-2012 IEEE
Effectiveness of an Educational Workshop on Palliative Care Knowledge in Lebanese Nurses
Get PDFBackground: Lebanon is one of the world’s smallest countries, with an area of 10,452 square kilometers. Life expectancy in Lebanon presently stands at about 76.6 years for men and 79.3 years for women. It is well known that with long life comes chronic disease, serious illness, and increased resource utilization. With a rapidly aging population and ever-increasing life expectancy, an increase in illnesses that affect the elderly is expected to follow, including non-communicable diseases and cancer. Nurses are the largest workforce in Lebanon and are thus in a prominent position to influence the quality of palliative care (PC) delivery throughout the course of illness. Purpose: The purpose of this study was to evaluate the impact of an educational workshop on PC knowledge, attitude, and skills for practicing nurses at a Lebanese university medical center. Design: A mixed-method approach comprising a quasi-experimental and a qualitative process evaluation was followed to assess the nurses’ knowledge, attitude, and skills about PC before and after the workshop and to evaluate the process itself. A convenience sample of 45 registered nurses working at the university medical center from multiple clinical units participated in the workshop that took place over one day in a referral medical center in Beirut. Inferential statistical analysis was used. Results: Data were analyzed using SPSS 25 for Windows. The paired t test showed a significant increase between the pre-and post-test scores t (39) = 11.07, p < 0.001 with a 95% confidence interval for the mean difference of (17.58–25.45). Thirty-eight participants (90.5%) did not pass the pre-test exam whereas only 12 participants (30.0%) did not pass the post-test exam. Recommendations: It is highly recommended to follow up with the participants of this workshop to determine the immediate and long-term outcomes of this educational workshop as well as offer workshops for a wider population of nurses in Lebanon and the region. ª Myrna A.A. Doumit et al
The association of management and leadership competencies with work satisfaction among pharmacists in Lebanon
Get PDFBackground: Pharmacists are at the core of the healthcare system and are the most accessible healthcare professionals. Their new roles involve leadership skills, among others. Work satisfaction of pharmacists might affect the quality of the services they provide. Hence, the primary objective of this study was to evaluate the management/leadership skills and work satisfaction of pharmacists and working pharmacy students. The secondary objective was to establish the relationship between management/leadership competencies and work satisfaction. Methods: This cross-sectional study enrolled 415 Lebanese pharmacists and fifth-year pharmacy students (undergraduates) working in different pharmacy sectors across Lebanon from August 2021 through October 2021 using the snowball sampling technique and validated tools to assess management/leadership competencies and work satisfaction. Results: Management/leadership competencies were significantly correlated with work satisfaction (B = 0.288) and inversely associated with being engaged/married (B = − 2.825) and living outside Beirut or Mount Lebanon (B = − 1.873). Pharmacy students did not significantly differ in their leadership/management level from graduate pharmacists. Work satisfaction was significantly associated with management/leadership competencies (B = 0.062) and inversely related to education level (B = − 0.644). Conclusions: Pharmacists’ work satisfaction and management/leadership competencies are interrelated, although the level of satisfaction seemed lower than the declared level of competencies. These concepts are differentially affected by personal and work-related characteristics. More efforts should be exerted to improve both the satisfaction and management/leadership competencies of pharmacists in Lebanon. © 2023, The Author(s)
A framework for high-throughput sequence alignment using real processing-in-memory systems
Get PDFMotivation: Sequence alignment is a memory bound computation whose performance in modern systems is limited by the memory bandwidth bottleneck. Processing-in-memory (PIM) architectures alleviate this bottleneck by providing the memory with computing competencies. We propose Alignment-in-Memory (AIM), a framework for high-throughput sequence alignment using PIM, and evaluate it on UPMEM, the first publicly available general-purpose programmable PIM system. Results: Our evaluation shows that a real PIM system can substantially outperform server-grade multi-threaded CPU systems running at full-scale when performing sequence alignment for a variety of algorithms, read lengths, and edit distance thresholds. We hope that our findings inspire more work on creating and accelerating bioinformatics algorithms for such real PIM systems. © The Author(s) 2023. Published by Oxford University Press
Comparison of design characteristics and toxicant emissions from Vuse Solo and Alto electronic nicotine delivery systems
Get PDFIntroduction: Vuse Solo is the first electronic nicotine delivery system (ENDS) authorised by the US Food and Drug Administration for marketing in the USA. Salient features of the Vuse Solo product such as nicotine form, draw resistance, power regulation and electrical characteristics have not been reported previously, and few studies have examined the nicotine and other toxicant emissions of this product. We investigated the design characteristics and toxicant emissions of the Solo as well as Alto, another Vuse product with a greater market share than Solo. Methods: Total/freebase nicotine, propylene glycol to vegetable glycerin ratio, carbonyl compounds (CC) and reactive oxygen species (ROS) were quantified by gas chromatography, high-performance liquid chromatography and fluorescence from aerosol emissions generated in 15 puffs of 4 s duration. The electric power control system was also analysed. Results: The average power delivered was 2.1 W and 3.9 W for Solo and Alto; neither system was temperature-controlled. Vuse Solo and Alto, respectively, emitted nicotine at a rate of 38 μg/s and 115 μg/s, predominantly in the protonated form (>90%). Alto's ROS yield was similar to a combustible cigarette and one order of magnitude greater than that of Solo. Total carbonyls from both products were two orders of magnitude lower than combustible cigarettes. Conclusion: Vuse Solo is an above-Ohm ENDS that emits approximately one-third the nicotine flux of a Marlboro Red cigarette (129 μg/s) and considerably lower CC and ROS yields than a combustible cigarette. With its higher power, the nicotine flux and ROS yield from Alto are similar to Marlboro Red levels; Alto may thus present greater abuse liability than the lower sales-volume Solo. © Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ
Last Planner System Framework to Assess Planning Reliability in Architectural Design
No full textThe Last Planner System (LPS) aims to enhance planning reliability by reducing variability in construction processes. While LPS applications have been explored in construction and detailed design, its application in architectural design remains underrepresented due to its abstract nature. This study addresses this gap by proposing an LPS framework tailored for architectural design, utilizing LPS metrics to assess planning reliability. Key issues hindering formal planning methods’ implementation are identified, and relevant LPS principles are aligned with these challenges, culminating in a conceptual LPS model designed for architectural projects. Building upon the conceptual model, an implementation model was developed and put into practice within an architectural design company in the United States, resulting in measured improvements in planning reliability and responsiveness. Additionally, it unveils hidden challenges associated with emerging tasks, guiding future design process enhancements. This study demonstrates how tracking design planning performance with LPS metrics can promote LPS adoption in architectural design, offering a benchmark for necessary interventions to achieve desired performance in architectural design. © 2023 by the authors
A DEEP LEARNING FRAMEWORK FOR MODEL-FREE,TIME-VARYING PATTERN DISCOVERY IN EEG SIGNAL DYNAMICS: APPLICATION TO EPILEPTIC EVENTS
No full textDue to the enhancements in sensor technology and cloud computing, multichannel time series data is readily acquired and analyzed in many real-world problems. However, since the multichannel data has a high dimension and is often acquired over a long duration of time, data analysis is cumbersome visually and computationally challenging despite available resources. In this thesis, we propose a model-free framework for multichannel data analysis to provide a comprehensive insight into the time-varying governing dynamics using a window-based approach and an incremental approach. We evaluate the framework and show its utility using real magneto-encephalogram (MEG) data acquired during cognitive tasks and using clinical seizure electroencephalogram (EEG) data during epileptic events. The complexity of interactions among multichannel data is exemplified in brain dynamics analysis, whereby recordings often acquire the information not only locally, but also from other sources leading it to be multiplexed and contaminated with noise. To understand such dynamics, many researchers have employed biologically inspired models to identify key biological events and generate hypotheses that can be tested experimentally. Such physical models are often computationally expensive, and because they can only encompass an activity that is explicitly modeled, these models cannot guarantee that all the events will be captured. Therefore, we employ the model-free dynamic mode decomposition (DMD) method to find spectral, spatial, temporal, phase, and instability characteristics in the data and quantify the dynamics. The first objective examines a framework to extract dominant spatial patterns and their temporal evolution. The methodology is then adapted to study long multichannel time series data to extract spatial, temporal, and phase relationships between the channels in the form of color-coded dictionary maps we denote as DMDgrams. Next, we study the oscillatory events as instability of the system; since DMD extracts linear underlying subsystem, the fragility of the modes can be extracted and subsequently mapped onto the fragility in the original signal space (or channel fragility). We then evaluate the proposed measure using receiver operating characteristic curve analysis and patient-specific sequence learning models. The second objective makes use of the DMDgram and the fragility features to learn deep neural networks for seizure event detection. Attention mechanisms are added to the network to identify channels that are most active during seizures. The analysis in the previous objectives was performed using a window-based approach that cannot localize events in time accurately where the results may vary according to the considered window size. Therefore, in the third objective, the incremental dynamic mode decomposition is used to generate instantaneous features that accommodate time-varying characteristics and is suitable for online analysis. We also investigate smoothing and the transformation of the modes from the complex domain to the real domain where the instantaneous frequency, amplitude, and phase are extracted. Then, channel interactions are analyzed incrementally. The framework was tested on synthetic data and then validated using (1) multi-trial and multichannel MEG data obtained during three cognitive tasks, (2) real epileptic EEG data, and (3) intracranial EEG recordings aiming to locate the seizure onset zone. Our analysis shows that the proposed methodology is a useful tool to summarize the long-duration EEG data, study the underlying dynamics in a linearized domain from spectral, phase, and instability perspectives, and localize key spatiotemporal hidden events such as extracting dominant brain network configurations and exploring seizure onset zones
Inclusion of Nitrofurantoin into the Realm of Cancer Chemotherapy via Biology-Oriented Synthesis and Drug Repurposing
Get PDFStructural modifications of the antibacterial drug nitrofurantoin were envisioned, employing drug repurposing and biology-oriented drug synthesis, to serve as possible anticancer agents. Eleven compounds showed superior safety in non-cancerous human cells. Their antitumor efficacy was assessed on colorectal, breast, cervical, and liver cancer cells. Three compounds induced oxidative DNA damage in cancer cells with subsequent cellular apoptosis. They also upregulated the expression of Bax while downregulated that of Bcl-2 along with activating caspase 3/7. The DNA damage induced by these compounds, demonstrated by pATM nuclear shuttling, was comparable in both MCF7 and MDA-MB-231 (p53 mutant) cell lines. Mechanistic studies confirmed the dependence of these compounds on p53-mediated pathways as they suppressed the p53-MDM2 interaction. Indeed, exposure of radiosensitive prostatic cancer cells to low non-cytotoxic concentrations of compound 1 enhanced the cytotoxic response to radiation indicating a possible synergistic effect. In vivo antitumor activity was verified in an MCF7-xenograft animal model. © 2023 American Chemical Society