A food web modeling assessment of Asian Carp impacts in the Middle and Upper Mississippi River, USA

The invasion of non-native fishes has caused a great detriment to many of our native fishes. Since the introduction of invasive carps, such as Silver, Bighead, Common and Grass Carp, managers and researcher have been struggling to remove these species while also hypothesizing the detriment of further invasion. This study developed a food web model of four locations on the Mississippi River and used those models to assess the impacts of two scenarios: carp removal and carp invasion. In the Middle Mississippi River where these invasive carps are already present, the models found that it would take a sustained exploitation of up to 30% of initial biomass over an extended period to remove Grass Carp and up to 90% removal of initial biomass to remove Silver and Bighead Carp. In the locations where Silver, Bighead, and Grass Carp are not yet established (i.e., Pools 4,8, and 13) the invasion of these species could cause declines from 10 to 30% in initial biomass of native fishes as well as already established nonnative invasive species

Bioinspired soft matter self-assembly and its use in biomedical applications

The human body consists of a dynamic collection of polymers, colloids, and gels. Therefore, most biological matter is soft matter, and many biomedical products, such as 3D cell culture platforms or nanocarriers for drug and imaging agent delivery, often consist mostly of soft matter. Despite advances in these fields, concerns still exist regarding the function, reproducibility, and cost of soft matter systems for biomedical applications. To mitigate these concerns, we examined a variety of methods to utilize bioinspired self-assembly to improve the function of 3D cell culture platforms and drug- and imaging agent-loaded nanocarriers. The first part of this thesis investigates the role of a hydrophilic polymer in modulating the self-assembly of collagen molecules and the subsequent mechanical properties and permeability of the collagen gel. We further examined the combined effects of gel properties and external fluid flow on cancer cell phenotypes (Chapter 2). An additional study focuses on a 3D printing technique to form multifunctional hydrogels (Chapter 3). In parallel, this thesis examined the thermodynamic effects of solvent quality and microfluidic mixer-based oil/water mixing rate on the size of nano-sized polymeric micelles and vesicles (Chapter 4). An additional study focuses on a self-assembled cluster of imaging agents for stem cell labeling (Chapter 5). Furthermore, this thesis explored a strategy to significantly increase the bioavailability of drug molecules in nanoparticles by driving self-assembly between alpha-tocopherol (Vitamin E) and amphiphilic polymers. The resulting system was functionalized to target and enhance treatment of venous neointial hyperplasia (VNH) that often occurs at arteriovenous fistula (AVF) of patients who are undergoing dialysis therapy (Chapter 6). Overall, the studies included herein will contribute broad knowledge to the fundamental science and applications of self-assembled systems for biomedical tools and products

Notes and Discussion Piece: Status of the Topeka Shiner in Iowa

The Topeka shiner Notropis topeka is native to Iowa, Kansas, Minnesota, Missouri, Nebraska, and South Dakota and has been federally listed as endangered since 1998. Our goals were to determine the present distribution and qualitative status of Topeka shiners throughout its current range in Iowa and characterize the extent of decline in relation to its historic distribution. We compared the current (2016–2017) distribution to distributions portrayed in three earlier time periods. In 2016–2017 Topeka shiners were found in 12 of 20 HUC10 watersheds where they occurred historically. Their status was classified as stable in 21% of the HUC10 watersheds, possibly stable in 25%, possibly recovering in 8%, at risk in 33%, and possibly extirpated in 13% of the watersheds. The increasing trend in percent decline evident in earlier time periods reversed, going from 68% in 2010–11 to 40% in the most recent surveys. Following decades of decline, the status of Topeka shiners in Iowa appears to be improving. One potential reason for the reversal in the distributional decline of Topeka shiners in Iowa is the increasing number of oxbow restorations. Until a standardized monitoring program is established for Iowa, periodic status assessments such as this will be necessary to chronicle progress toward conserving this endangered fish species

11. An examination of the species-area-energy relationship driving decomposer diversity within “sponge” habitats in an estuarine bay

The species-area relationship is a well-known pattern in ecology detailing a strong positive relationship between habitat area and species richness. Alternatively, the species-energy hypothesis suggests that total energy availability drives species richness, with higher richness in systems with more energy input. While these two hypotheses are difficult to separate as they are positively related, they can be mutually exclusive. Species richness may increase with both area and energy availability independently. Here we test the relative importance of habitat area vs energy availability by placing two artificial substrates, polypropylene and cellulose sponges, with four different surface areas in two estuarine habitats. Cellulose sponges are organic and therefore should increase biodiversity by providing both protective structure and nutrition, while polypropylene sponges only provide structure. Organic sponges with large surface areas should promote more diversity than synthetic sponges with the same surface area. To test this, 40 cellulose and 40 polypropylene pre-weighed sponges of each surface area were placed in salt marshes and the open ocean of Terrebonne Bay in Louisiana. After one month, organisms were removed and categorized, and dry weight of the sponges collected. Preliminary results show that abundance was negatively related to surface area, contrary to predictions. However, organic sponges lost more mass, but supported similar abundances of organisms than polypropylene sponges. These results suggest that cellulose sponges are primarily used as nutrition as their effect should be additive if used as structure as well. This project offers important insights into the complexities that habitat diversity has on decomposer systems

Impacts of Real-Time Satellite-Derived Vegetation on WRF-Hydro Simulated Streamflow

No abstract availabl

Chemical Oxygen Demand as a Measure of Fluvial Organic Matter Oxidation State

The oxidative ratio (OR) of the terrestrial biosphere is directly related to the size of the terrestrial biosphere carbon sink. In turn, OR of naturally occurring organic matter can be directly related to the oxidation state of the carbon in naturally occurring organic matter (Cox). Chemical oxygen demand (COD) is a widely measured water quality parameter that has been used as a short‐term substitute for the biochemical oxygen demand (BOD). Here, we propose that if the concentration of reduced species is known, then COD measurement can be used to assess the oxidation state (Cox) of fluvial organic C. Using a Bayesian hierarchical modeling approach, this study analyzed 21 years of water quality monitoring across England to calculate Cox of fluvial organic matter. The study showed that (a) COD could not be considered separately from the reduced species (e.g., NH4) commonly occurring in freshwater water samples, but it was still possible to calculate the Cox of dissolved organic carbon (DOC) and particulate organic carbon (POC). (b) The median Cox of DOC was 0.23 with a 95th percentile range of −0.1 to 0.4. (c) The median Cox of POC was 0.20 with a 95th percentile range of 0.03–0.37. (d) The estimated Cox in fluvial systems confirms that BOD is decoupled from the production of CO2. Including new Cox estimates in the global estimate of OR gives a new median value of 1.059 with a 95th percentile range of 1.047–1.071, giving the annual flux of CO2 to land (fland) of 1.45 ± 0.1 Gt C/year

A Student Parent Assistance Pilot Program for Incoming Associate Degree Students

This Student Parent Assistance Pilot Program engaged family members to support their students in adapting to the academic challenges of entering college. Materials were constructed so that family members did not have to be knowledgeable in the course content in order to assist their students. Outcomes indicated that participating students and their family members had a more positive view of the program than did a non-participating comparison student group. A student vignette is used to illustrate the students’ positive view of the program