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Contrasting climate oscillations impacts on phytoplankton in the western and eastern tropical Pacific
No full textClimate oscillations like the El Niño-Southern Oscillation and Pacific Decadal Oscillation significantly impact marine ecosystems. Traditionally, warm events are thought to suppress nutrient availability, reduce phytoplankton biomass, and change community structure. However, using two decades of field observations, remote sensing, Copernicus reanalysis, and Earth system modeling, we find very different responses in the western tropical Pacific. During El Niño, chlorophyll concentrations and diatom contributions increase, while La Niña reverses that trend. The further amplification of these El Niño-Southern Oscillation-driven contrasts by the Pacific Decadal Oscillation can be attributed to its effects on regional circulation, including the enhancement of eddy activity that facilitates upwelling of nutrients and stimulates phytoplankton production. These findings go beyond the simple narrative of community structure shifts and suggest more complex physical-biological responses in the tropical Pacific. Consideration of these mechanisms will be crucial for improvement of climate change predictions and development of strategies for sustainable management
Artificial Intelligence for Drug Discovery and Environmental Sciences
No full textAddressing global health challenges and environmental threats requires innovative technological solutions. Despite advances in medicine, millions suffer from conditions lacking effective treatments, while antibiotic resistance grows and traditional drug development pipeline remains slow and costly. DeepDrug, our AI-powered drug design pipeline, accelerate therapeutic discovery by efficiently analyzing vast datasets to identify promising compounds. Simultaneously, climate change manifests through increasing natural disasters, pollution, habitat destruction, and agricultural disruption, threatening both human civilization and biodiversity. Our research demonstrates how artificial intelligence can address these dual challenges through advanced data analysis, predictive modeling, and decision support systems. We present applications ranging from drug discovery to environmental monitoring, including understanding satellite imagery, wildfire management, and predicting permafrost changes
Cuba\u27s Cosmopolitan Enclaves: Imperialism and Internationalism in Eastern Sugar Towns (review)
No full textWhen Old Meets New: Two Louisiana State University Outreach Librarians Build, Work, and Learn Together to Support Collaborative Student Engagement
No full textIn this essay, outreach librarians Mitch Fontenot (he/him), Louisiana State University, and Alia Kempton (she/her), Louisiana State University, Special Collections, reflect on their inaugural year of working together, highlighting key achievements, challenges, and growth that have marked their collaborative journey. They discuss how they established effective communication, built trust, and developed a shared understanding of goals and expectations. Additionally, they explore where they envision their partnership heading in the future, touching on long-term aspirations, potential areas for deeper collaboration, and the strategies they plan to implement to continue fostering a successful and productive working relationship
Evolutionary History of the Obligate Lung Parasite Pneumocystis
No full textAlthough most extant species are parasites, we know relatively little about their diversity and diversification compared to free-living organisms. Exemplifying this research gap is Pneumocystis, a fungal obligate parasite of mammal lungs ubiquitous throughout Mammalia. While Pneumocystis likely contains thousands of host-specific species, only 6 have been formally described, and only ~4% of mammal species have been screened. Broader mammal sampling would certainly uncover many novel species, but this unculturable genus is difficult to study and largely characterized by mitochondrial gene sequences. Pneumocystis evolutionary history therefore remains unclear, with interpretations often falling back on assumptions of strict one-to-one host specificity and cospeciation as the primary drivers of its diversification.
In this dissertation, I re-examined this cospeciation paradigm by analyzing existing single-locus mitochondrial data (Chapter 2). My results showed that neither one-to-one specificity nor cospeciation is supported, and that there are likely between 4,500 and 6,000 extant Pneumocystis species. I then tested for cospeciation in a pair of deermouse sister species (Peromyscus) by sequencing single mitochondrial and nuclear loci from Pneumocystis (Chapter 3), finding that both host species share two distantly related Pneumocystis taxa rather than unique, cospeciated taxa. To expand nuclear sampling, I designed a UCE probe set for Pneumocystis and other members of the Taphrinomycotina, enabling recovery of genome-scale data even from museum and herbarium specimens dominated by host DNA (Chapter 4). I leveraged these data to infer a well-resolved phylogenetic hypothesis and explore the origins of mammalian parasitism through divergence time estimation, which supported an origin of Pneumocystis contemporaneous with placental mammals. Finally, I returned to the question of host specificity by sampling Pneumocystis across North American rodents in the subfamily Neotominae (Chapter 5). Results showed that relaxed multi-host associations are common, and that codiversification, parasite inertia, and spillover events together best explain observed host-parasite associations, rather than strict cospeciation.
By bridging the gap between single-locus sequencing and genome-scale UCE capture for Pneumocystis, this dissertation demonstrates the power of molecular approaches for illuminating the biology of unculturable microbial parasites. Through such approaches, we can better understand the forces that have shaped most branches on the tree of life
Sex-specific effects on the heart from combined exposure to simulated galactic cosmic radiation and hindlimb unloading
No full textFuture long duration space missions will expose astronauts to higher doses of galactic cosmic radiation (GCR) than those experienced on the international space station. Recent studies have demonstrated astronauts may be at risk for cardiovascular complications due to increased radiation exposure and fluid shift from microgravity. However, there is a lack of direct evidence on how the cardiovascular system is affected by GCR and microgravity since no astronauts have been exposed to exploratory mission relevant GCR doses. Therefore, we utilized a ground-based mouse model to determine the cardiovascular risks for space radiation exposure while the mice were simultaneously hindlimb suspended to mimic microgravity. 6-month-old male and female C57BL/6 mice were exposed to an absorbed dose of 0 Gy, 0.5 Gy, or 1.5 Gy simulated GCR (GCRsim) that comprised beams of 5 ions at NASA\u27s Space Radiation Laboratory. Subcohorts of mice were hindlimb unloaded (HLU), starting 5 days before GCRsim until the completion of radiation exposure. GCRsim + HLU was performed over 8 hours (0.5 Gy) or 24 hours (1.5 Gy). After completion of GCRsim and HLU, mice were shipped to UAMS for long-term observation. Cardiac function was measured using high resolution ultrasound at 6 and 9 months after exposure. Tissues were collected after the final ultrasound and prepared for further analysis. Female mice exposed to 1.5 Gy + HLU demonstrated a significant increase in body weight compared to ground controls months after GCR exposure; however, there was no change in male body weights. Cardiac ultrasound revealed 0.5 Gy GCRsim decreased left ventricular (LV) mass, LV posterior wall thickness in diastole, and systole in males 6 months after exposure. In females, 1.5 Gy + HLU significantly increased LV posterior wall thickness in diastole and systole at 6 months. These changes in ultrasound measurements were no longer seen at 9 months. Moreover, at 9 months there was no change in total collagen content or density of the capillary network in the heart. Lastly, the combination of GCRsim and HLU influenced immune cell markers in the heart of female mice. These data suggest that combined simulated GCR and microgravity result in minor, yet statistically significant sex-dependent changes to body weight and cardiac structure
Structure of beta-decaying states in the deformed, neutron-rich nucleus 104Nb
No full textExcited structures in 104Mo were populated by β decays of the ground and isomeric states in the neutron-rich nucleus 104Nb. The beams were produced by the CARIBU facility at Argonne National Laboratory, re-accelerated by the ATLAS accelerator and implanted on a moving-tape system in the middle of the GAMMASPHERE array. Separate decay schemes for the two β-decaying states in 104Nb were constructed for the first time. The structure of the isomers are discussed in the framework of the deformed Nilsson model and systematics of known quasiparticle structures in neighboring nuclei
Terpenes in Agricultural Byproducts: Identification, Extraction, and Application
No full textThis study investigated the valorization of agricultural byproducts as sustainable sources of bioactive terpenes with potential applications in food preservation and nutritional enhancement. Seven agricultural byproducts such as sweet potato peel, cornsilk, sorghum bran, watermelon rind, honeydew peel, pineapple peel, and Perilla frutescens leaves were examined for their free and bound terpene contents using different extraction media. Polar solvents such as water and ethanol produced higher crude yields (2.9 ± 0.1% to 9.3 ± 1.0%; 3.1 ± 0.1% to 8.7 ± 1.1%) while acetone provided lower mass recovery (2.1 ± 0.1% to 8.4 ± 1.0%). Sweet potato peel and Perilla frutescens leaves were identified as rich sources of bound terpenes, emphasizing the significance of optimizing extraction and hydrolysis protocols to maximize the recovery and functional utilization of these bioactive compounds.
Perilla frutescens extracts were evaluated against major foodborne pathogens such as Listeria monocytogenes, Salmonella enterica, and Escherichia coli. The incorporation of free and bound terpenes from the Perilla frutescens extract into ground pork resulted in a significant reduction of Escherichia coli O157:H7 during refrigerated storage and confirmed their antimicrobial efficacy within complex food matrices.
The antioxidant activity of essential oils such as juniper berry, sandalwood, copaiba, and peppermint from Amazon were assessed in fish oil to evaluate their ability to stabilize polyunsaturated fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). While copaiba and peppermint oils provided minimal oxidative stabilization (10.08 ± 0.10% and 3.88 ± 0.02%; 49.91 ± 0.35% and 14.96 ± 0.16%), sandalwood and juniper berry oils exhibited greater antioxidant performance (52.91 ± 0.15% and 34.02 ± 0.18 %; 47.88 ± 0.18 % and 45.79 ± 0.12 %) for EPA and DHA after 48 h. Their constituents, rich in oxygenated monoterpenes and sesquiterpenes, conferred strong radical scavenging and singlet oxygen quenching abilities. The acetone extract of Perilla frutescens displayed moderate antioxidant activity, reflecting the limited activity of bound terpene glycosides until hydrolyzed.
Finally, the findings of this study establish agricultural byproducts such as sweet potato peel, corn silk, watermelon rind, honeydew peel and pineapple peel as promising renewable sources of bound terpenes with dual antimicrobial and antioxidant functionalities
Drawing Disintegration: A Twice-Exceptional Individual’s Autoethnographic Inquiry into Graphic Narrative Creation as a Tool for Processing Trauma
No full textThis autoethnographic study explores the researcher’s lived experience of childhood trauma as a twice exceptional individual with an arts-based autoethnography research design, specifically in the form of graphic narrative. Grounded in Dabrowski’s Theory of Positive Disintegration (TPD), this study examines how emotional and sensory intensity, overexcitability (OE), and psychological disintegration intersect with twice-exceptional (2e) identity development and identity authenticity potential. Data sources include personal artifacts from childhood and adulthood—journals, letters, graphic narrative, documents, and photographs—alongside reflective writings and completed graphic narrative pages. Using descriptive coding and TPD’s developmental levels as analytic lenses, the study interprets the processes of disintegration and reintegration over time. Results indicate that visual storytelling enabled deeper engagement with trauma and offered an embodied pathway toward integration. The creative process transformed disintegration into self-understanding, revealing how creative expression can channel emotional intensity into reconstruction of the self. The results of this study contribute to the field of gifted education, illuminating how autoethno-graphic narratives can serve as both research method and therapeutic pedagogy, supporting 2e learners, specifically those with OEs, in processing trauma and developing authenticity identity