The Response of Marine Synechococcus to a Landscape of Environmental Stressors: a Proteomic Exploration

In the field of marine microbial ecology, many questions remain unanswered with regards to the physiological trade-offs made by phytoplankton to maximize growth (e.g., nutrient acquisition) and minimize loss (e.g., predation defenses). These tradeoffs, which occur at the cellular level, have wide reaching impacts on food web dynamics and global biogeochemical cycles. In the first chapter, we explored the use of a non-canonical amino acid (NCAA) technique, bioorthogonal non-canonical amino-acid tagging (BONCAT), in phytoplankton model systems. This technique has potential to work well in natural systems by enabling isolation of only newly synthesized proteins during an incubation period with the NCAA, reducing the complexity of natural proteomics and easing the elucidation of patterns. However, in testing BONCAT across several groups of cultured phytoplankton, we discovered that the NCAA molecule induced a stress response in the globally ubiquitous marine picocyanobacteria, Synechococcus sp. Therefore, in addition to confirming the uptake of modified amino acids by phytoplankton, chapter one investigated the implications of this stress response and limitations when using this technique to study marine microbial communities. In chapter two, we addressed our initial question by exploring tradeoffs at the protein level in a simplified culture system. This approach revealed insights into metabolic tradeoffs in response to predation pressure and nutrient stress. These insights into how phytoplankton negotiate these physiological tradeoffs at the protein level could ultimately allow for targeted proteomic studies in natural systems

Sedentary Behavior, Quality of Life, and Perceived Occupational Performance Following Goal-Based Interventions among Community-Dwelling Older Adults

Older adults, aged 65 and older, who participate in prolonged sedentary behaviors are at an increased risk for adverse health outcomes, disease, and disability. There is limited research exploring the relationship between sedentary behaviors, physical activity, and the effect on occupational performance. This study utilized a one-group, pretest-posttest design. The aim was to explore physical activity, sedentary behavior, quality of life, and perceived occupational performance among community-dwelling older adults before and after goal-based, occupational therapy interventions involving meaningful occupations. This study included a group of six community-dwelling older adults, two males and four females, between the ages of 76 and 87 (M = 81.83, SD = 3.87). Preliminary data demonstrate that participants increased their perception of occupational performance from 5.17 (SD=1.95) to 6.07 (SD=2.63) following goal-based intervention. Similarly, participants demonstrated an increase in their perceived satisfaction with their occupational performance from 4.67 (SD=1.96) to 6.65 (SD=2.48) following goal-based intervention. Further data analysis will be conducted to determine the significance of these aforementioned values. Additional comparisons of pretest and posttest results will determine the significance of other assessment measures of physical activity, sedentary behaviors, quality of life, and perceived occupational performance among community-dwelling older adults. Keywords: Sedentary behaviors, older adults, community-dwelling, quality of life, goal-based intervention

Data from: Diet breadth and exploitation of exotic plants shift the core microbiome of Cephaloleia, a group of tropical herbivorous beetles

The beetle genus Cephaloleia has evolved in association with tropical ginger plants and for many species their specific host plant associations are known. Here we show that the core microbiome of six closely related Costa Rican Cephaloleia species comprises only eight bacterial groups, including members of the Acinetobacter, Enterobacteriacea, Pseudomonas, Lactococcus, and Comamonas. The Acinetobacter and Enterobacteriacea together accounted for 35% of the total average 16S rRNA ribotypes recovered from all specimens. Further, microbiome diversity and community structure was significantly linked to beetle diet breadth, between those foraging on less than two plant types (specialists) versus over nine plant types (generalists). Moraxellaceae, Enterobacteriaceae, and Pseudomonadaceae were highly prevalent in specialist species, and also present in eggs, while Rickettsiaceae associated exclusively with generalist beetles. Bacteria isolated from Cephaloleia digestive systems had distinct capabilities and suggested a possible beneficial role in both digestion of plant-based compounds, including xylose, mannitol, and pectin, and possible detoxification, via lipases. Cephaloleia species are currently expanding their diets to include exotic invasive plants, yet it is unknown whether their microbial community plays a role in this transition. In this study, colonization of invasive plants was correlated with a dysbiosis of the microbiome, suggesting a possible relationship between gut bacteria and niche adaptation