Who Speaks for the River?: The Oldman River Dam and the Search for Justice by Robert Girvan

Cory T. Shaman reviews Who Speaks for the River?: The Oldman River Dam and the Search for Justice by Robert Girvan

Sociohydrologic Systems Thinking: An Analysis of Undergraduate Students’ Operationalization and Modeling of Coupled Human-Water Systems

One of the keys to science and environmental literacy is systems thinking. Learning how to think about the interactions between systems, the far-reaching effects of a system, and the dynamic nature of systems are all critical outcomes of science learning. However, students need support to develop systems thinking skills in undergraduate geoscience classrooms. While systems thinking-focused instruction has the potential to benefit student learning, gaps exist in our understanding of students’ use of systems thinking to operationalize and model SHS, as well as their metacognitive evaluation of systems thinking. To address this need, we have designed, implemented, refined, and studied an introductory-level, interdisciplinary course focused on coupled human-water, or sociohydrologic, systems. Data for this study comes from three consecutive iterations of the course and involves student models and explanations for a socio-hydrologic issue (n = 163). To analyze this data, we counted themed features of the drawn models and applied an operationalization rubric to the written responses. Analyses of the written explanations reveal statistically-significant differences between underlying categories of systems thinking (F(5, 768) = 401.6, p \u3c 0.05). Students were best able to operationalize their systems thinking about problem identification (M = 2.22, SD = 0.73) as compared to unintended consequences (M = 1.43, SD = 1.11). Student-generated systems thinking models revealed statistically significant differences between system components, patterns, and mechanisms, F(2, 132) = 3.06, p \u3c 0.05. Students focused most strongly on system components (M = 13.54, SD = 7.15) as compared to related processes or mechanisms. Qualitative data demonstrated three types of model limitation including scope/scale, temporal, and specific components/mechanisms/patterns excluded. These findings have implications for supporting systems thinking in undergraduate geoscience classrooms, as well as insight into links between these two skills

Enabling Dynamic Vehicle Analyses With Improved Atmospheric Attenuation Models in Glenn Research Center Communication Analysis Suite

To aid in meeting the NASA objective of returning humans to the Moon, the Glenn Research Centers Communication Analysis Suite was augmented with two distinct capabilities. The first capability added was the vehicle propagator. This allows the addition of dynamic aircraft and ground vehicles around any celestial body within the solar system during an analysis. This functionality interpolates the position and velocity of the vehicle relative to a celestial body at the time steps analyzed using the type of path and either a series of waypoints or a direction and duration of travel. The implications of this new capability include lunar rovers and/or drones, such as Dragonfly, where the vehicle propagator will analyze the communications architecture. The newly created vehicle propagator is now in use in communications studies for the 2024 lunar missions, simulating the movement of lunar rovers across the Moons southern pole. The second capability added was the augmentation of the atmospheric attenuation model. The previous model did not have a uniform low-elevation attenuation model due to the trigonometric approximation for path length and the exponential nature of low-elevation scintillation. User-defined weather parameters were also added to the updated atmospheric attenuation model. The previous model solely used tabular data based upon the season and location of the transmitting antenna. Multiple simulations of the same configuration now return different results based on the differing weather parameters. Cognitive communications analysis efforts can use this second capability to generate neural network training data based on differing weather conditions at utilized ground stations, a critical step in allowing neural networks to learn how weather parameters impact communications performance

Compatibility of Glyphosate with Galerucella calmariensis; a Biological Control Agent for Purple Loosestrife (Lythrum salicaria)

By integrating Galerucella calmariensis with glyphosate there is potential to achieve both immediate and sustained control of purple loosestrife (Lythrum salicaria). The objective of this study was to determine the compatibility of glyphosate on the oviposition and survival of adult G. Calmariensis and on the ability of G. calmariensis third instar larvae to pupate to teneral adults. Our results revealed glyphosate (formulated as Roundup) at a concentration of 2% (2.43L/acre) and 4% solution (4.86 L/acre) had no impact on the ability of G. calmariensis third instar larvae to pupate to new generation adults. To examine the effect of a 2% solution of glyphosate on adult G. calmariensis oviposition and survival, adults were randomly divided between a direct contact group (adults sprayed directly), an indirect contact group (host plants with adults were sprayed), and a control group. Our results revealed that glyphosate does not impact G. calmariensis oviposition or adult survival. The results of this study indicate that G. calmariensis is compatible with glyphosate indicating that further field studies examining integrated control strategies for purple loosestrife are warranted

Investigating Novel Methods of Interaction with Pharmaceutically Relevant Enzymes

Metalloproteins requiring one or more metal ions for normal function make up 30% of all known proteins, and many critical biological pathways contain at least one metallo-enzyme. Di-nuclear metallo-proteins constitute a large class of these proteins yet we currently lack effective methods of inhibiting these enzymes for the development of new medical therapies, particularly for the discovery of new antibiotics. Our work has focused on developing novel functionalities that selectively interact with di-nuclear catalytic centers, and we are targeting three separate di-zinc-metallo-enzymes that are unique to bacteria and play key roles in their growth and development. These enzymes are DapE, AiiA, and NDM-1. DapE is involved in biosynthesis of lysine and meso-diaminopimelic acid, essential precursors in the production of bacterial cell walls. AiiA is a di-Zn-dependent lactonase involved in bacterial cell-cell communication, and NDM-1 is a di-metallo-beta-lactamase capable of deactivating the most commonly administered antibiotics, gaining international attention for this enzyme as a clinically-relevant pharmaceutical target, yet drug development efforts have proven ineffective due to a lack of effective inhibitors. As part of our ongoing studies to functionally annotate the Gcn5-related N-acetyltransferase (GNAT) PA4794 from Pseudomonas aeruginosa with unknown functions, we have used PA4794 as a model system for exploring efficient formation of bisubstrate complexes to enhance our success rate in obtaining co-crystal structures of GNATs with ligands bound in their acceptor sites. We have synthesized and tested substrate analogs of the previously identified N-phenylacetyl glycine lysine (NPAcGK) enabling two separate three-dimensional structures of PA4794 with NPAcGK analog-derived bisubstrates formed through direct reaction with CoA—the first through direct alkylation with a reactive substrate, and the second through X-ray induced radical-mediated process. We have also performed docking and molecular dynamics simulations of the reverse reaction pathway from the NPAcGK product back to formation of the tetrahedral intermediate/transition state to complement our structural work and to explore the key ligand-protein interactions within the active site of PA4794, guiding mutant synthesis and kinetics to explore the role of key residues in the active site

Amos v. Commissioner: The Ambiguous and Ever-Changing Definition of What Constitutes a Person Physical Injury under Internal Revenue Code Section 104(A)(2)

Amos v. Commissione