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 Soils from Different Solidago altissima Clones Mediate Intraspecific Interactions in Schizachyrium scoparium(Saudi Digital Library, 2025-08) Alharbi, Sarah; Meiners, ScottWhile previous studies have examined plant intraspecific competition and soil microbial effects separately, fewer studies have investigated how these factors interact, particularly in the context of genotype-specific soil conditioning effects. Plant-soil feedbacks can significantly alter interspecific competitive outcomes, yet few studies have examined how local variation in soil conditioning influences plant responses to density-dependent competition. I investigated how soil inocula derived from four Solidago altissima clones that were previously shown to differ in their soil conditioning effects (Foster et al., 2022) affected the growth and root traits of Schizachyrium scoparium across a gradient of intraspecific competition (1, 2, or 4 plants per pot). Plants were grown in live versus autoclaved soil inocula from each clone for 60 days, and I measured total biomass, root mass fraction, specific root length, and root dry matter content. Differences between live and autoclaved soil treatments varied dramatically among S. altissima clones, with generally negative effects of live soil on S. scoparium biomass but complex, trait-specific responses that depended on both clone identity and plant density. Three-way interactions were significant in multiple traits, indicating that soil conditioning effects on intraspecific competition were highly context-dependent and clone-specific. These results suggest that different S. altissima clones condition soil environments in ways that create distinct competitive contexts for neighboring plants, potentially through differential soil microbial associations. My findings suggest that clone-specific soil conditioning effects within plant populations may be an underappreciated mechanism shaping competitive dynamics and community structure in grassland ecosystems.25 0Item Restricted Ensemble Defense System: Combining Signature-based and Behavioral-based Intrusion Detection Tools(2023-08-04) Alharbi, Sarah; De Lucia, MichaelCyber attacks are becoming increasingly sophisticated, which poses significant challenges for organizations in detecting and preventing these attacks. Implementing robust defense mechanisms that can detect, prevent, and respond to these threats and attacks is crucial. In this thesis, we design, develop, and evaluate a novel Ensemble Defense System (EDS), addressing the critical need for advanced defense systems. The EDS combines the capabilities of Intrusion Detection Systems (IDS) and Security Information and Event Management (SIEM) to provide an effective defense against cyber threats. The EDS incorporates hybrid-based IDS technologies, leveraging the strengths of signature-based IDS tools like Zeek and Suricata and behavioral-based IDS tools like Slips. By utilizing hybrid-based IDS, the EDS provides a more effective system for countering cyber threats. Moreover, the EDS integrates open-source SIEM, specifically Elasticsearch, to provide data management and analysis capabilities and create user-friendly visualization. The effectiveness of the EDS has been evaluated through a designed bash script that performs several attacks, such as port scanning, privilege escalation, and Denial-of-Service (DoS). This research contributes to better cybersecurity by introducing an EDS that can detect various cyber attacks.58 0