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Dr. George M. Austin, 1916-2002
No full textDr. George M. Austin, Neurosurgeonhttps://scholarsrepository.llu.edu/george-austin-collection-gallery/1009/thumbnail.jp
Lead Along Arid Route 66: Concentration, Fate, Surface Transport, and Awareness
No full textFate and transport of lead (Pb) are well studied in humid, high precipitation environments. Few studies have compared or addressed fate of lead (Pb) in arid, low precipitation areas where the soil binding capacity may differ from classic studies. The goal of this study is to identify the control of fate and transport in the arid section of Route 66 by determining the concentration, chemical forms, and surface transport mechanism of lead (Pb) along the arid section of Route 66. Understanding the fate and transport of lead (Pb) in different environments is key in the environmental mitigation of lead (Pb) contamination. Two sites were studied, site 1 and Site 2. Site 2 was found to have more samples with elevated levels of lead (Pb) than site 1. In both sites, elevated levels of lead (Pb) were found in the road berms and close to the road margin. Surface runoff is most likely the main surface transport mechanism and reducible lead (Pb) fraction is the most common chemical form. Data from this study suggest that soil texture is the main control of fate and transport of lead (Pb) in the arid section of Route 66
Guide to the George M. Austin Research Collection
Full text linkThe Dr. George M. Austin Research Collection was donated to the Loma Linda University Department of Archives and Special Collections in 2023. The collection is available for consultation within the department, in the Del E Webb Memorial Library, Loma Linda, Ca. Many of the files have been digitized and are also available via the Universities institutional repository, Scholars Repository.
The collection includes research materials spanning 1948-1995, primarily focusing on Dr. Austin\u27s work on brain aneurysms and related neurological topics. The collection also contains personal and professional papers, reflecting Dr. Austin\u27s career as a neurosurgeon, researcher, and educator
The Association of Acute Stress and Single Leg Balance
Full text linkChronic low back pain is a widespread and expensive societal burden that is routinely near the top of the list of reasons people live with a disability. There is an undeniable connection between low back pain and psychological stress, and it has long been accepted that stress comes as a consequence of the burden of pain. Our group sought to determine if the inverse of this paradigm might be true: that stress may actually play a role in the etiology of low back pain through its influence on neuromuscular control and strategies for balance stability. In this dissertation, we include a brief review of the literature regarding the complex interplay of stress physiology, low back pain, and neuromuscular trunk control. In Chapters 2 and 3 we have included two manuscripts, the first of which is a published protocol for the Feigned Annoyance and Frustration Test—a novel modality that we have determined to be valid for inducing stress in a lab setting. The second manuscript includes our analysis of the neuromuscular impact of stress on a single leg balance task. In brief: individuals demonstrated decreased activation of key trunk muscles after exposure to stress and individuals with low back pain exhibited a greater number of differences in muscle activation compared to healthy controls. The final chapter includes a summary of suggestions for future research based on the components in our dataset that have yet to be explored
E6 Inhibtion-Mediated Combinatorial Therapy for HPV+ HNSCC
Full text linkHigh-risk human papillomaviruses (HPV) are the causative agents of virtually all cases of cervical cancer and up to 80% of head and neck squamous cell carcinoma (HNSCC). Current treatment options include chemo- and radiotherapy, though the effectiveness of these therapies is limited by the viral oncoprotein E6, which disrupts apoptotic pathways by binding to and accelerating the degradation of molecules such as p53 and caspase- 8. Our hypothesis was that inhibiting E6 and rescuing the apoptotic mediators would increase the effectiveness of apoptotic agents. The aims of this study were to first, develop an HPV+ HNSCC xenograft model to test small E6 inhibiting molecules; and second, to evaluate the antitumor efficacy of lead molecules in an established in vivo model. We fulfilled the first aim by optimizing an HNSCC xenogral model using UM-SCC47 cells, incorporating Matrigel, and applying luciferase technology. Our lab has identified two E6 inhibitors from two different sources: spinacine was identified following screening of the TimTec Actiprobe 2K library, and 30-hydroxygambogic acid (GA-OH) was identified following screening of the Kansas University 5K library with subsequent follow-up. Both compounds were shown to rescue the apoptotic signaling molecules and to re-sensitize cancer cells to apoptosis in vitro. To further explore the therapeutic potential of these small molecules, we determined their toxicity and antitumor efficacy in vivo. Spinacine exhibited no toxicity to mice at doses up to and including 20 mg/kg but did not yield evidence of efficacy on tumor growth either alone or when combined with apoptotic agents. Subsequently, our lab demonstrated that GA-OH had higher specificity and effectiveness than our previous lead molecules in vitro. Therefore, we assessed GA-OH’s toxicity and evaluated the effectiveness of GA-OH in combination with chemotherapy. Behavioral/physical assessments, body weight, organ necropsy, and blood tests, with the possible exception of creatine kinase, all pointed towards lack of significance toxicity, predicting tolerance. Moreover, we were able to demonstrate that our animal model was functional, and that cetuximab slowed and regressed tumor growth. We found that GAOH alone did not slow tumor growth; however, when combined with cisplatin, GA-OH enhanced cisplatin’s efficacy in HPV+ HNSCC in vivo
Religion and PTSD in Puerto Rico Natural Disaster Survivors
Full text linkReligious coping can influence recovery from natural disaster trauma. Participants were recruited from a religiously sponsored university in Puerto Rico, affected by several natural disasters between 2017 and 2020, using an online survey. A significant relationship was found between negative religious coping and changes in mood and cognition, mediated by the effect of worthiness of self. Results indicate that negative religious coping may adversely influence an individual’s view of self and increase PTSD-related changes in mood and cognition. If clinicians only examine a client’s view of self, they may miss the influence of negative religious coping
Impact of Maximal and Minimal Mouth Opening on Mandibular Flexure via Scanning
Full text linkBackground: Mandibular flexure during mouth opening affects prosthodontic outcomes, but digital scanner research is limited.
Methods: Seventy dental students (35 males, 35 females) had two impressions taken: one with maximum and one with minimum mouth opening.
Results: First molars showed higher deviations than premolars. Females had larger deviations, though not statistically significant.
Conclusion: First molars exhibit greater flexure than premolars.
Keywords: Mandibular flexure, deformation, mouth opening, digital, intraoral scan, three dimensional(3D), prostheti
Comparing sensing and signaling mechanisms across Aer2 receptors with different N-terminal domain arrangements
Full text linkBacteria use chemoreceptors and associated chemosensory systems to navigate and respond to their environment. Aer2 chemoreceptors are a family of O2 sensors that all have a common core structure but differ with regards to their N-terminal domain types and arrangements. The Aer2 receptors from Pseudomonas aeruginosa (PaAer2) and Vibrio cholerae (VcAer2) have been extensively studied. However, the marine pathogen Vibrio vulnificus possesses a previously uncharacterized Aer2 receptor. Here I present an analysis of the V. vulnificus Aer2 chemoreceptor, VvAer2, which is the first V. vulnificus chemoreceptor to be characterized. VvAer2 is related to the Aer2 receptors of other gammaproteobacteria, but uncharacteristically contains three PAS domains (PAS1-3), rather than one or two PAS domains. PAS domains are sensing, signaling, dimerization, and protein interaction domains found in proteins from all five kingdoms of life. Using an E. coli chemotaxis hijack assay, I determined that VvAer2, like other Aer2 receptors, senses and responds to O2. All three VvAer2 PAS domains bound pentacoordinate b-type heme and exhibited similar O2 affinities. PAS2 and PAS3 both stabilized O2 via conserved Ib-Trp residues, but PAS1, which was easily oxidized in vitro, was unaffected by Ib-Trp replacement. Collectively, my results support a model in which PAS1 is largely dispensable for O2-mediated signaling, whereas PAS2 modulates PAS3 signaling, and PAS3 signals to the downstream domains. Each PAS domain appears to be positionally optimized, since PAS swapping caused altered signaling properties, and neither PAS1 nor PAS2 could replace PAS3.
I also explored the conservation of signaling mechanisms across Aer2 receptors. I introduced and tested residue replacements in VvAer2 and VcAer2 that were previously characterized in PaAer2, and I created and tested chimeric Vibrio Aer2 receptors. Overall, I determined that Aer2 signaling involves a Cterminal PAS-heme domain that binds O2 and signals via largely conserved mechanisms. However, each Aer2 receptor has evolved to work efficiently with its own complement of N-terminal domains and arrangement. These distinct Nterminal domain arrangements facilitate, modulate and tune responses based on environmental signals
Sleep, Body Dissatisfaction, and Eating Among Adolescents
Full text linkSleep difficulties in adolescence have been linked to greater impulsivity, negative affect, propensity to interpret neutral stimuli as negative, and higher rates of anxiety and depressive symptomatology (Van Dyk, 2016). However, minimal research has looked at the relationship among sleep difficulties, emotional eating, and body dissatisfaction within this population. Therefore, the aim of the current study was to explore the relationship among sleep difficulties, emotional eating, and body dissatisfaction among adolescents aged 12-18 years. Specifically, the current study stands to 1) confirm the relationship between emotional eating and body dissatisfaction; 2) test if sleep difficulties are related to emotional eating; 3) test if sleep difficulties are related to body dissatisfaction; 4) test if body dissatisfaction moderates the relationship between emotional eating and sleep difficulties; and 5) test if body dissatisfaction mediates the relationship between emotional eating and sleep difficulties. Bivariate analyses revealed shorter sleep duration was correlated with body dissatisfaction in the direction of desiring thinness (r = -0.323, p \u3c .05). Multiple linear regressions showed a moderation effect of body dissatisfaction on the relationship between sleep duration and emotional eating, such that for adolescents desiring thinness, shorter sleep was associated with increased emotional eating in response to feeling angry, anxious, and/or depressed, R2Δ = .138, F(1, 52) = 8.613, p \u3c .05. Thus, results from the current study highlight the use of sleep optimization treatments as possible intervention strategies for youth with high levels of body dissatisfaction and emotional eating tendencies
Perceived Business Skills Needs of MFTs: Implications for a Doctoral Program
Full text linkThe purpose of this study was twofold: a) to determine the training that MFTs should have to effectively work in organizational / business settings and with organizational / business issues in the role of clinician, administrator / manager, consultant, coach, and researcher and b) to determine what components should be included in a model curriculum in the area of organizational / management studies in an MFT doctoral program. Using the e-Delphi method, consensus from a panel of experts (in the profession of marriage and family therapy as well as in business / management / organizational issues) was obtained. Panelists identified thirty-eight business disciplines / topical areas that MFTs should be exposed to, with varying degrees of emphasis. Of these thirty-eight areas, eight were identified as themes that should run across the curriculum. For the remaining thirty areas (of which six were perceived as deserving of being the primary focus of a course) suggestions were made as to learning activities and learning resources. Panelists also provided suggestions pertaining to additional training and the nature of course learning modalities. Using the study results, course syllabi were developed by the researcher for four of the six key areas. Additionally, consistent with the study’s theoretical framework, these thirty-eight areas were organized by the researcher according to Bronfenbrenner’s bioecological system theory of human development