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Finite element analysis of hydroxyapatite (HA) coated porous WE43 magnesium scaffolds for simulating long-time in vitro degradation using a continuum damage model
No full textWhile magnesium and its alloys are viable biodegradable implant candidates for its similarity of Young’s modulus with human bone and its strong biocompatibility, a pure magnesium scaffold degrades too rapidly to be used in many orthopedic implications. Overcoming this high degradation rate has been one of the biggest technical challenges for Mg-based biomedical applications. This research focuses on validating a finite element analysis framework using a continuum damage model and its application to simulate the degradation process of non-coated additively manufactured WE43 and HA-coated WE43 magnesium scaffolds. This work includes determining model input parameters by matching in vitro experiment results and investigating the details of HA coating effects for biodegradable magnesium scaffolds. This research extends the models by applying long-time degradation for HA-coated WE43 magnesium scaffolds to determine the long-term mechanical integrity of such biodegradable implants. Furthermore, it examines the effect of the HA coating thickness, which serves as a benchmark for surface-modified coated biodegradable implant models for determining the optimal thickness of the HA coating. This research is significant because it is: 1) A predictive finite element degradation model for HA-coated WE43 magnesium scaffold calibrated using in vitro experiment. Micrometer-level fine mesh size HA coating finite element simulation gives us insight into the effect of HA coating on suspending degradation when applied to biomedical areas. 2) Expanding the degradation models by applying long-time degradation for HA-coated WE43 magnesium scaffold gives us the knowledge for long-time degradation up to 250 days close to practical implications in biodegradable implants. 3) A comprehensive comparison of the proposed HA-coated WE43 magnesium scaffold finite models using a continuum damage model with in vitro degradation experiments. 4) The implementation of the proposed HA-coated WE43 scaffold framework to examine the degradation of HA-coated scaffold in vitro experiment with the capacity of multi-layered micro level of details to investigate of HA coating thickness effect, which serves standard for surface-modified coated biodegradable implant models by providing HA coating thickness effect for optimal treatment of HA coating for the magnesium scaffold
The effects of alfaxalone, alone or with butorphanol, on the ultrasonographic appearance of the feline spleen
No full textThe sonographic effects of alfaxalone and butorphanol alone and in combination on feline splenic size, shape, margins, echogenicity, echotexture, and blood flow were investigated. In this randomized, prospective crossover study, 8 healthy adult cats were injected with alfaxalone 2.0 mg/kg IM, butorphanol 0.2 mg/kg IM, and each drug in combination. Splenic ultrasounds were performed before drug administration, then every 15 minutes for 1 hour. Heart rate, respiratory rate, and feline multiparametric sedation scores (FMSS) were recorded. Following at least a 7-day washout period, cats switched groups and the study was repeated. An increase in splenic size and no significant changes to other appearance parameters occurred for all protocols compared to baseline, with no significant difference between treatments. Alfaxalone alone increased FMSS but resulted in aggression in 1 cat. Alfaxalone with butorphanol provided the best quality sedation and may be used in cats for ultrasound without significant changes to splenic appearance
AI enabled Autonomic, safe, and interactive Intrusion Response System
No full textThe exponential rise in internet usage has precipitated a corresponding surge in cyber threats, underscoring the urgent need for advanced cybersecurity solutions. While traditional intrusion detection systems (IDS) can identify these threats, their inability to self-recover leaves systems vulnerable. Intrusion response systems (IRS) have been developed to address this, aiming to auto- matically restore systems to their desired state post-security breach. However, current IRSs often necessitate manual intervention and may not be su!ciently robust against sophisticated threats. To overcome these limitations, we propose an AI-powered Autonomic, Safe, and Interactive Intrusion Response System called ‘Intrusion Response System Digital Assistant (IRSDA)’. IRSDA is based on autonomous computing systems (ACS) and leverages Self-Adaptive ACS (SAACS) to adjust its behavior in response to the environment. The system extends an SAACS im- plementation called Autonomous Intelligent Cyber defense Agents (AICA). IRSDA incorporates machine learning techniques, such as Large Language Models (LLMs), Reinforcement Learn- ing (RL), and Graph Neural Networks (GNN), to enable automated decision-making and threat analysis. Additionally, the system employs transfer learning to bootstrap models in a production environment and accelerate response time. Finally, IRSDA to follows an n-tier architecture based on a client-server and multi-agent system model. To enhance the system’s robustness, we propose using enterprise system partitions, rules of engagement, and knowledge graphs. Enterprise systems consist of partitions, each of which is a discrete section that operates independently. IRSDA agents function in a partition-focus scope with a local optimization objective while collectively working towards the global optimization goal of securing enterprise systems. IRSDA agents can compute a wide range of potential responses to meet its security goals and objectives. To restrict its activities and minimize collateral damage, the system must have set Rules of Engagement (RoE). Finally, IRSDA leverages AI technologies and allows Enterprise Security personnel to interact with it using natural language queries
Projected future reservoir impairment in the conterminous United States following three climate change scenarios
No full textAnthropogenic climate change has been associated with reservoir aging and reduced ecosystem function. Communities throughout the world depend on reservoirs for services such as hydropower, drinking water, flood mitigation, and recreational opportunities. Though reservoirs were typically constructed to meet human needs, they are now also acknowledged as supporting biodiverse aquatic communities. Reservoir managers are expected to maintain services and biodiversity demanded by diverse users despite high uncertainty surrounding how climate will influence reservoirs through time. Additionally, data describing reservoir function at broad spatial extents are often either unavailable, incompatible between agencies, or prohibitively resource-intensive to obtain. Expert opinion surveys are one alternative to in situ data, leveraging the experience and knowledge of those working on reservoir systems to identify broad patterns of impairment. I related information on reservoir impairment from expert opinion surveys covering 1090 reservoirs distributed across the conterminous United States with climate data to inform decision makers on how climate affects reservoir function. To integrate a complex data structure, I constructed a series of models using logistic regression, random forest, support vector machine, and multilayer perceptron neural networks. Models were compared by predictive and discriminatory ability to identify which could most effectively classify reservoir impairment. Support vector machine emerged as the best performing model by accuracy, Cohen’s Kappa, and area under the receiver operating characteristic curve. This model was used to project impairment scores for four time intervals and three future climate scenarios. Twelve spatially distinct clusters of reservoirs were identified by similar climate conditions, and future impairment was projected for the conterminous United States, each climatic cluster, and individual reservoirs. These results are compiled in a web application developed in R-Shiny to inform decision makers about future climate conditions relevant to their needs. My study demonstrates the information value of expert opinion surveys in contexts where empirical data are unavailable or decision makers are obliged to make a decision before such data can be obtained. I also demonstrate the potential of machine learning techniques on diverse data structures, identify metrics for evaluating and comparing models, and provide general recommendations for applying such models in ecological research
Synthetic data augmentation for retinoblastoma using diffusion
No full textMany AI models rely on large and high quality datasets for optimal training. In certain cases, data can be difficult or expensive to obtain, making training difficult. Rare medical conditions are one of these cases. Datasets for retinoblastoma are severely lacking in quantity. Diffusion has been used to create synthetic data in the industrial, medical, and financial domains. By applying the latest Diffusion methods to retinoblastoma, this work seeks to improve predictive model performance on identifying retinoblastoma
Shifting Sands: Moving from Reality to Unreality
No full textThis is a series of stories that shifts from literary fiction to science fiction, each with their own inspiration and message. Inspirations include The Twilight Zone, Benjamin Percy, Da-Lin, Gabriel Garcia Marquez, The Sandman, and Endymion. Each of these stories is conversant with norms and traditions of storytelling and the connections between these and their inspirations are elaborated on in the Introduction that accompanies the collection as a whole
Evolution of the occurrence of phytomelanin in aerial stems of American Vernonieae subtribes (Asteraceae)
No full textPhytomelanin is a dark pigment frequently reported in fruits and/or seeds, but recently described in aerial stems of species of the tribe Vernonieae, in subtribe Lychnophorinae. We hereby report the presence of this pigment in aerial stems of additional species belonging to this tribe and investigate the evolution of its occurrence in these lineages. Samples from 42 species belonging to the main lineages of American Vernonieae subtribes, and two species belonging to an outgroup, were analyzed with traditional plant anatomy techniques. The ancestral states of phytomelanin occurrence were reconstructed with maximum likelihood methods, using a recent phylogenetic hypothesis of American Vernonieae based on molecular data. Of the species listed for the present study, the secretion of phytomelanin, when present, was observed in the intercellular spaces of the sclereids. The pigment is more frequently found in the pith, secondary phloem, and cortex. The ancestral state reconstruction suggests that the most recent common ancestor of tribe Vernonieae had phytomelanin in those three regions. The phylogenetic signal for presence of phytomelanin in these regions may indicate this character was preserved throughout the evolutionary history of the tribe. Thus, the ability to produce phytomelanin would have been conserved in the more nested lineages of the American Vernonieae subtribes, although it could also reflect distinct ecological adaptations across lineages
Further disintegration of Piptocarphinae, an amplified concept of Critoniopsis and notes on the occurrence of paleae in Piptocarpha (Compositae: Vernonieae)
No full textThe circumscription of the tribe Vernonieae (Compositae) has been problematic due to the reorganisation of the polyphyletic genus Vernonia and the creation of many small genera. Recent phylogenetic studies have focused on the relationships within Vernonieae but few studies have explored the generic relationships within subtribe Piptocarphinae. Of note, some diagnostic features of Piptocarphinae are not unique to the subtribe and are found in other Vernonieae genera. In this study, we explored the phylogenetic relationships in Piptocarphinae, the genus boundaries in this subtribe and tested the infrageneric affinities of the paleate species, using previously published and newly generated nuclear ITS sequences for 65% of the genera of American Vernonieae. Results agree with previous phylogenetic studies, where nearly all subtribes are seemingly paraphyletic or polyphyletic. Piptocarphinae emerges as polyphyletic and should be reduced to contain only the monophyletic Piptocarpha, whereas Critoniopsis is monophyletic only if Cuatrecasanthus is included. We propose placing Cuatrecasanthus and Joseanthus in synonymy of Critoniopsis, resulting in eight new combinations: C. chimborazensis, C. giannasii, C. flexipappa, C. kingii, C. lanceolatus, C. sandemanii, C. sparrei and C. trichotoma and a new name, C. boekei. Piptocoma also resolves as non-monophyletic but no taxonomic recommendations are made, as few species have been sampled in phylogenies so far. We present a new combination in the genus Piptocarpha, P. glomerulata. The presence of paleae likely emerged independently at least three times in American Vernonieae. Paleate receptacles are present in three different series in Piptocarpha subg. Piptocarpha, which indicates that paleae have likely arisen twice in the evolution of Piptocarpha. Finally, a brief discussion about the adaptive function of paleae and pappus is provided
DR-4429: Social Perceptions and Narratives of the 2019 Mississippi Delta Flood
Get PDFThis thesis examines the social perceptions and narratives surrounding the 2019 Mississippi Delta flood. Recognizing flooding as a “wicked problem,” the research highlights how socioeconomic and cultural identities relate to access to resources and assistance for affected communities, with an emphasis on infrastructure. Through qualitative analysis, including thematic coding of journalistic media sources covering the flood, the study explores the perceptions and experiences as well as the concept of ‘deservingness’ and its relationship with government resources and assistance. Findings indicate that the Mississippi Delta community faced temporal barriers to post-flood recovery due to disparities in representation and perception, underscoring the importance of local knowledge and cultural memory in shaping resilience. Recommendations most strongly include enhancing community engagement in decision-making processes and sourcing funding for effective flood control infrastructure supported by residents, advocating for a flood management approach including an analysis of local perceptions and narratives to understand needs and impacts
Churches in Hazelhurst, Mississippi
No full textColor illustrations of both the Baptist Church and and the Methodist Church in Hazelhurst, Mississippi are depicted on this postcard. The Baptist church, a two story building with six round columns across the front entrance and a tall, leafy tree at the right corner is pictured in the upper left of the card hile the Gothic revival style Methodist church is in the lower left of the card. Hazelhurst is printed in the upper right yellow space and Mississippi is printed in the lower left yellow space.https://scholarsjunction.msstate.edu/mss-lampton-images-ms-capitol/1543/thumbnail.jp