SACM - United States of America
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9668
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Item Restricted ASSESSING PRELAMIN A PROCESSING AND PHENOTYPIC EFFECTS OF LMNA MUTATIONS IN A RESIDUE ADJACENT TO THE ZMPSTE24 CLEAVAGE SITE(Johns Hopkins University, 2025) Alkhamis, Danyah; Michaelis, SusanLamin A is a nuclear scaffold protein, synthesized as a precursor called prelamin A, which undergoes several steps of posttranslational processing. This study explores the impact of mutations that affect the final proteolytic processing step, which is mediated by the zinc metalloprotease ZMPSTE24. We assessed the effects of these LMNA mutations, specifically at the L647 residue, on nuclear morphology and protein processing. After establishing a HeLa T-REx cell culture system, we expressed wild-type GFP-tagged LMNA and 11 GFP-tagged LMNA mutants. These mutations were examined against the abnormalities seen in cells from patients with Hutchinson-Gilford Progeria Syndrome (HGPS) and other disorders characterized by the accumulation of unprocessed prelamin A. Results in mammalian cells were compared to previous work performed in a humanized yeast system. Our findings indicate that diminished processing of prelamin seen in the yeast system is recapitulated in mammalian cells. Our results also indicate significant nuclear morphological abnormalities. However, there were no specific correlations between mutations with low cleavage efficiency and higher abnormal nuclei count. This research marks a significant step in understanding the impact of mutations at L647 in prelamin A processing and associated cellular defects. Overall, this study lays the foundation for future investigations into understanding the molecular mechanisms of how LMNA mutations may result in diseases.31 0Item Restricted Assessing the Impact of Certificate of Need Laws on Organ Transplantation Outcomes(Middle Tennessee State University, 2025) Alaohaid, Mohammed; Baum, CharlesThis dissertation examines how institutional regulations and regional dynamics influence the availability and quality of organ transplantation services in the United States. The first chapter assesses the average effect of certificate-of-need (CON) regulations on transplant outcomes across five organs—heart, kidney, liver, lung, and pancreas—using center-level data from 2010 to 2023. Although CON regulations generally enhance availability, they are associated with lower average quality, particularly for heart and liver transplants, possibly due to expanded access for higher-risk patients. The second chapter employs a synthetic difference-in-differences approach to evaluate the effects of repealing and reinstating CON laws on kidney transplants in two states: New Hampshire and Indiana. The findings indicate significant changes in market share, while the changes in availability and quality are either modest or not statistically significant after policy changes. This suggests that the impact of CON regulations may be influenced by regional factors and the initial market conditions of each state. The third chapter investigates knowledge spillovers in heart transplantation using an instrumental variable approach. It finds that centers in regions with higher transplant activity benefit from shared expertise, improving patient selection and procedural efficiency. However, increased transplant rates may also coincide with lower average survival outcomes, likely due to the inclusion of more clinically complex patients. Collectively, these chapters contribute to the literature on healthcare regulation by providing empirical evidence on how policy design and regional specialization influence outcomes in high-stakes medical services. The findings highlight the importance of interpreting average outcome metrics in light of patient heterogeneity and institutional context and suggest that regulatory and regional collaboration strategies can play a critical role in improving transplant care.13 0Item Restricted INVESTIGATING THE NATURE AND IMPLEMENTATION OF GOVERNMENTAL POLICIES ON THE INCLUSION OF STUDENTS WITH MILD/MODERATE DISABILITIES IN GENERAL EDUCATION SETTINGS IN SAUDI ARABIA(Kent State University, 2025) Alanazi, Hani Hulayyil; Stevenson, NathanThe government of Saudi Arabia has made significant efforts to provide inclusive education for students with disabilities. Inclusive education enables students with disabilities to receive the same educational services and opportunities as their non-disabled peers. However, the current educational system still faces challenges in achieving effective inclusion. The broad goal of effective inclusion is to provide appropriate services and accommodations for individual educational programs and supports that ensure quality education for all children. Many governments, including Saudi Arabia, have advanced specific policies for the inclusion of students with disabilities, particularly those with mild to moderate disabilities, in general education programs. Nevertheless, Saudi Arabia is still in the preliminary stages of integrating students with disabilities into general educational environments. This study focuses specifically on the perspectives and lived experiences of special education teachers working in elementary schools in Riyadh. The study examines the extent to which existing educational policies in Saudi Arabia encourage the inclusion of students with moderate to severe disabilities in general education classrooms, according to teachers charged with enacting such policies. By analyzing how these teachers interpret and apply inclusive education policies in their everyday practice, the study seeks to illuminate the real-world challenges and contextual dynamics influencing policy implementation. The study identifies systemic gaps and areas where major changes or further improvements are needed to increase the number of students with disabilities in inclusive educational settings. By investigating the current state of inclusive education policies and practices in Saudi Arabia, this research aims to contribute to the development of a more equitable and inclusive educational system for all students.14 0Item Restricted EXAMINING READINESS FOR PATIENTS AND THEIR COMPANIONS TO TRANSFER FROM HOSPITALS TO SKILLED NURSING FACILITIES IN SAUDI ARABIA(University of San Diego, 2025) Noshili, Fahad; Connelly, CynthiaAbstract Purpose/Aim: This study assessed the readiness of chronically ill patients in Saudi Arabia for transfer from hospitals to skilled nursing facilities (SNFs). It aimed to identify factors that influence this readiness and provide suggestions for making transitions easier. Background: Maintaining chronic patients' ability to transition from hospitals to SNFs is critical for healthcare continuity and quality. However, patients' preparedness for this transition may vary by various factors, including clinical status, caregiver support, and demographics. Conceptual Framework: This study is based on Meleis's Transitional Theory, which highlights the significance of understanding the processes and factors that affect transitions in healthcare environments. This framework is especially pertinent for analyzing the transfer of patients with chronic illnesses from hospitals to SNFs in Saudi Arabia. Methods: A descriptive correlational cross-sectional design was employed. A convenience sample of 123 chronic patients and their companions (families) in hospitals was recruited and enrolled in Saudi Arabia hospitals. After providing informed consent, participants completed surveys that included standardized measures to assess chronic patients' readiness to transition from hospitals to SNFs. The study utilized descriptive and inferential statistical analyses to evaluate variables such as sociodemographic characteristics, clinical profiles, caregiver support, and perceived barriers to transition. Findings: Education, income, chronic illness, self-rated health, and caregiver preparedness significantly predicted readiness to transfer patients from hospitals to SNFs in Saudi Arabia. Education level, income, and self-reported health predicted greater readiness; caregiver involvement positively influenced transition quality. Length of stay, age, and sex made no difference. The findings underscore the importance of interventions to improve caregiver training, financial support, health literacy, and standardizing discharge planning to improve patient transitions. Implications: Policy interventions are needed to help the patient transition from hospital to SNFs in Saudi Arabia. The most common recommendations addressed improving caregiver education, financial support resources, resource allocation using a standardized discharge planning process, and caregiver training programs promoting preparedness. In line with Saudi Arabia's Vision 2030, these measures are intended to create patient- centered care, create fewer obstacles to readiness, and improve overall healthcare outcomes.39 0Item Restricted Demonstration and Assessment of Dark Field and Phase X-ray Computed Tomography(University at Albany State University of New York, 2025) Allahyani, Wadiah Hamed; MacDonald, Carolyn AConventional computed tomography produces a 2D slice or 3D image from multiple conventional images to avoid overlapping structures and increase visualization of the internal features of the object. A set up, macro controls and processing for computed tomography was created for the Center for X-ray Optics for the first time, and demonstrated in this work. Adding differential phase contrast to conventional x-ray images highlights edges. Two more channels of information, dark field and integrated phase, improve the contrast and increase the signal-to-noise ratios of the image. Combining these channels with computed tomography is an important development. This work is the first demonstration of phase and dark field tomography for the Center. Mesh-based x-ray phase imaging is a technique used to extract five computed channels: computed attenuation along with vertical and horizontal dark field and differential phase contrast images. The integrated phase image is computed from the differential phases. A periodic, metal, inexpensive mesh is employed to visualize the distortion of the x-ray beam when a sample present. Fourier transform techniques are utilized to produce those channels. A simple set up was developed to demonstrate computed attenuation, dark field and phase x-ray CT. The signal-to-noise ratios were quantified for the first time for mesh-based CT with a conventional source. The SNR for a strong scatterer was demonstrated to be a factor of 10 higher than the attenuation contrast for a slice through a CT image. Geometric-flow x-ray phase imaging (also known as optical-flow) is another method used in this research for phase reconstruction and combined with computed tomography to produce a phase channel in addition to the conventional CT. This may be the first demonstration of this technique with a conventional, large spot, source. The differential phase images in orthogonal directions map the deformation of the reference pattern. A wire mesh or sandpaper can be used as a reference pattern in the optical-flow technique. The quality of the differential phase x-ray computed tomography was measured for the first time, by edge enhancement and the signal-to-noise ratio SNR. Optimization experiments were performed for the edge enhancement by varying the x-ray voltage and adjusting the distance between the sample to the detector. Similarly, the contrast SNR was examined versus the exposure time for the integrated phase CT.10 0Item Restricted Navigating Male Partner Infertility Through a Bowen Family Systems Theory Lens: An In-depth Analysis of Women’s Experience and Psychological Interventions(Nova Southeastern University, 2025) Khalil, Dania; Venetia, Bennett; Tracey-Ann, SpencerMale infertility can be disturbing to individuals in a relationship system where the reproduction of children is one of the agreed upon goals of the relationship. This life crisis can cause severe emotional and psychological distress for the female partner within the relationship system. Additionally, social pressure, and other effects outside of the relationship system may be experienced and cause further distress to these women. This ACP critically analyzed the literature on the emotional experience of females whose male partner is struggling with infertility, their mental health, treatment journey, relational concerns, and coping strategies utilized by those women to manage the stress associated with such a condition. The review identified several gaps, notably the limited research on the emotional experience of women whose partner was diagnosed with infertility. Additionally, limited research surrounds the implementation of psychotherapeutic interventions that could help the targeted population. In response to these gaps, this project will conduct a critical analysis of the literature utilizing Bowen family system theory (BFST) to make sense of the women's experiences. In addition, it will incorporate BFST in the development of a psychotherapeutic intervention for clinicians that will assist in improving women's capacity to manage stress linked to their male partner's infertility and address the inadequacies. The intervention proposed will help increase women's level of differentiation, enabling them to make rational responses as they interact with their spouses as well as the larger system.5 0Item Restricted Polydopamine-ECM Coated Titanium to Promote Cementogenesis on Dental Implants(Harvard University, 2025) Alamri, Osamah; Traverso, GiovanniTitanium dental implants integrate directly with the surrounding bone, a phenomenon known as osseointegration. Unlike natural teeth, which are supported by periodontal ligaments (PDL), osseointegrated implants have weaker mechanical barriers against bacterial infiltration, heightened inflammation, reduced blood flow, and limited proprioception. Current methods to regenerate peri-implant ligaments involve costly, invasive, and time-intensive procedures. Polydopamine (PDA) is a biocompatible polymer known for its excellent adhesive properties. Periodontal ligament fibroblasts (PDLFs) play a pivotal role in periodontal tissue maintenance. Recent evidence suggests fibroblasts can induce a cementogenic phenotype by altering titanium surface topography and depositing cementum-like tissue. This study investigates PDA's efficacy in immobilizing ECM produced by PDLFs on titanium, hypothesizing enhanced cementogenesis on PDA-coated titanium surfaces. We assessed ECM immobilization efficiency, optimized decellularization protocols to retain ECM, and evaluated PDLF differentiation into a cementogenic phenotype. PDLFs cultured on PDA-coated titanium underwent decellularization after 10 days, followed by recellularization for 14 days. Cell interactions and gene expression were assessed using immunofluorescence microscopy, scanning electron microscopy (SEM), and RT-qPCR. Results demonstrated increased cell numbers on PDA-coated surfaces without affecting attachment or proliferation. Decellularization effectively removed cellular material, preserving key ECM proteins like Collagen I and CEMP-1. Gene expression analysis revealed significant upregulation of cementogenic markers (CP23, CAP, CEMP1, BSP) and downregulation of osteogenic markers (ALP, SOST), especially prominent on PDA-ECM surfaces. Our findings support that PDA-ECM-coated titanium surfaces promote cementogenic differentiation of PDLFs, potentially enabling peri-implant cementum-like tissue formation and periodontal ligament regeneration.15 0Item Restricted Industrial AI-based Workload Performance Analytics: Applications to Mixed Reality Multitasking(University of Illinois at Chicago, 2025) Abbas, Safanah Mohammed H; He, DavidImmersive technologies such as augmented and virtual reality are increasingly integrated into our daily lives. As this digital transformation progresses, understanding human reactions to these technologies becomes crucial, particularly in the context of human factors engineering, which prioritizes human safety and well-being. Mixed reality (MR), which blends the physical and virtual worlds, introduces new multitasking possibilities but also presents challenges. One critical aspect is the impact of MR multitasking on human workload, a key performance measure. This research employs an Industrial AI approach, combining traditional machine learning with advanced pre-trained models to develop predictive models for estimating human workload in MR environments. An experiment was conducted in which participants multitasked between a physical and a digital task within a defined timeframe. Workload data, collected via the NASA Task Load Index (NASA-TLX), was used alongside synthetic data generated by a Generative Adversarial Network (GAN) to create an enriched dataset. The combined real and synthetic data were then used to train predictive models, enhancing accuracy. To improve workload prediction, this study integrates pre-trained models such as BERT (Bidirectional Encoder Representations from Transformers) from large language models (LLMs) and CLIP (Contrastive Language-Image Pretraining) from computer vision applications, alongside traditional machine learning techniques like regression and neural networks. Evaluation using the Root Mean Square Error (RMSE) metric demonstrates that the proposed hybrid models incorporating transfer learning and pre-trained models significantly outperformed conventional methods. The deviations between actual and predicted values were minimal, indicating a more reliable workload estimation. This dissertation advances knowledge in human factors engineering by addressing a critical gap in workload prediction within MR multitasking environments. The findings provide insights into human-computer interaction in complex digital settings. Organizations implementing MR technologies can leverage these predictive models to better understand worker workload and optimize conditions for well-being and efficiency.9 0Item Restricted THE EFFECT OF FRUCTOSE METABOLISM ON HEPATIC DE NOVO LIPOGENESIS AND ADIPOSE TISSUE INSULIN RESISTANCE(University of Kentucky, 2025-05) Fadhul, Taghreed; Softic, SamirThere is a worldwide epidemic of obesity and metabolic dysfunction. The root cause of obesity is driven by a positive energy balance, which is a consequence of increased caloric intake and decreased energy expenditure. Energy intake is the more dominant force, as increasing energy expenditure is a time-consuming and labor-intensive process. The caloric surplus can be mainly accounted for by increased consumption of high-fat and high- sugar diets. While the risks associated with fat consumption are well-documented, the impact of sugar intake is less understood. Fructose is a simple sugar widely consumed in modern diets. Its intake has been associated with various metabolic disorders such as obesity, insulin resistance, chronic kidney disease, hypertension, metabolic dysfunction associated with steatotic liver disease (MASLD) and others. The most detrimental effects of fructose are observed when co- ingested with a high-fat diet (HFD). Fructose is mainly metabolized in the liver, kidney, and intestines. Its negative health effects have been linked to its strong propensity to induce de novo lipogenesis (DNL). This dissertation investigated whether fructose intake in the absence of HFD is sufficient to induce metabolic dysfunction and if its metabolism by other organs, such as adipose tissue (AT), plays a role in the development of metabolic dysfunction. To investigate whether fructose intake is sufficient to induce metabolic dysfunction, male and female mice were studied on three different normal chow diets: Boston Chow Diet (BCD), Lexington Chow Diet (LXD), and Low-Fat Diet (LFD). The diets had different fat-to-carbohydrate ratios, with BCD > LXD > LFD having the most fat. Additionally, the mice were provided regular water or 30% fructose solution in water. In males, fructose supplementation on BCD led to weight gain, glucose intolerance, and hepatic steatosis, whereas on LXD, fructose did not induce these adverse effects. Moreover, male mice on LFD did not gain weight, but once switched to BCD they did gain weight and developed metabolic dysfunction. Interestingly, female mice did not gain weight and remained insulin-sensitive even on BCD when supplemented with fructose. However, they did develop hepatic steatosis. These findings indicate that metabolic dysfunction associated with fructose intake is not a universal finding but, rather, is influenced by the dietary fat-to-carbohydrate ratio of the diet, duration of dietary exposure, and sex of the mice. AT is an important organ in orchestrating metabolic homeostasis. Fructose intake increases adiposity, but whether fructose can be directly metabolized in AT is not known. Male mice were fed a Chow diet or 60% high-fat diet (HFD) and supplemented with either regular water, 30% fructose-, or 30% glucose-solution for ten weeks. Fructose and glucose had similar effects on fat mass and adipocyte size, but only fructose and not glucose intake reduced beneficial adipokines, such as adiponectin and resistin, in HFD-fed mice. This is associated with increased crown-like structures, elevated inflammatory markers, and impaired insulin signaling (p-AKT) in visceral adipose tissue (VAT) of fructose-fed mice on a HFD. Moreover, when fructose metabolism in the liver was prevented via KHK siRNA, more fructose was available to be metabolized in AT, which worsened AT inflammation and metabolic dysfunction. In terms of its metabolism, fructose supplementation elevated HK1 and HK3 expression in VAT. The specific fructose transporter, Glut5, was absent in AT. However, Glut1 expression was increased with fructose supplementation in AT. In vitro, fructose was as sufficient as glucose to promote the differentiation of 3T3-L1 and stromal vascular fraction (SVF) into fully differentiated adipocytes. In human subjects, fructose supplementation was associated with elevated inflammatory markers and increased HK3 expression. HK3 expression was also increased in obese compared to the lean individuals. These findings indicate that adipose tissue may serve as an inducible site for fructose metabolism under conditions of high fructose intake or when fructose metabolism is prevented in the liver. In summary, fructose intake on a normal chow diet is sufficient to induce metabolic dysfunction only when consumed on diets with high fat-to-carbohydrate ratios. The effects of fructose are also sex-specific, as female mice are better at compensating for the detrimental effects of fructose largely due to estrogen, which enhances insulin sensitivity and promotes fat oxidation. While the liver, kidney, and intestine are the primary sites of fructose metabolism, AT may also participate in fructose metabolism under specific situations which raise serum fructose levels. It remains to be determined which specific cell types in AT mediate fructose metabolism.10 0Item Restricted Judging a book by its cover: Investigating the influence of test takers' physical attractiveness in synchronous oral communication assessment(Iowa State University, 2025) Aseeri, Fatimah Mohammed; Gary, OckeyThe assessment of Oral communication (OC) is an important measure of students' English language proficiency. In OC assessments, raters are commonly exposed to the visual appearance of the test takers, and depending on the test taker's physical attractiveness (PA), they may award students higher or lower scores than their actual ability. However, due to challenges associated with measuring social appearance values, research on this topic has only scratched the surface of this critical issue. Therefore, this study aims to investigate potential impacts of test takers’ physical attractiveness on their oral assessment scores. In phase I, a small exploratory study was conducted to define the PA construct and develop a PA scale. Phase II followed a concurrent embedded research design where quantitative and qualitative measures were applied. Quantitative measures including Many Facet Rasch Measurement and regression were used to investigate several aspects. First, the study investigated whether raters assign different scores to the test takers in two video conferencing modes: when exposed to test takers physical appearance (Face-to-Face) and when not exposed to it (Avatar-Mediated). Second, it explored whether raters show systematic bias in their evaluations based on the presence or absence of the test takers physical appearance. Then, it aimed at finding whether physical attractiveness is a potential explanatory variable that predicts test takers' OC scores in the F2FVC mode. Qualitative methods were conducted to investigate raters' perceptions about their rating process in the two modes (Face-to-Face vs. Avatar-Mediated), and whether they believe that physical attractiveness of the test takers may have affected their rating in the Face-to-Face video conferencing mode. The Many-facet Rasch Measurement analysis showed that 30 test takers received slightly higher scores in the Face-to-Face video conferencing mode compared to the Avatar-Mediated video conferencing mode. Yet, the difference was not significant (X2 = 3.6, d.f. =1, p = 0.06). Although not significant, four out of the 30 test takers failed the exam in Avatar-Mediated video conferencing mode, and would have passed the exam if the score difference between the two modes would have been awarded. Bias analysis found that out of the five expert raters, one showed significant bias towards the F2FVC mode (t (237) = −2.30, p < .05). Simple regression analysis of 41 test takers OC scores and PA scores revealed that test takers' PA significantly predicted their pronunciation scores within the OC construct, with female participants scores being more impacted than male participants. Findings from the qualitative analysis showed that the raters perceived the mode of delivery as having no impact on their rating decisions. They also believed that physical attractiveness of the test takers should not impact their rating, and if it did, it is unintentional. The findings of this research provide evidence of PA being a source of construct irrelevant variance in test takers' scores. Although this research does not end the controversy, it suggests that Patzer’s (1985) statement that “people do judge a book by its cover despite their claim to do the contrary" is true, at least for some people.21 0