Connections Granted

 This presentation will cover a recent grant for anatomical models at Texas Tech University. Three librarians collaborated to develop this grant and followed up with an analysis of the impacts of grant outcomes. During this process the Covid lock downs impacted access and acquisition of the deliverables, however, despite this, the research indicated that the need was actually increased due to outreach and the collection has seen new use through the additional models added and the expansion of services to new universities in the region. Through this process data from circulation on usage and a survey sent to various stakeholders, both within and outside of Texas Tech University was analyzed. The survey asked both professors and students to assess what was currently in circulation and suggest what the collection needed in the future. It was through this survey that connections with Lubbock Christian University and other outside stakeholders were involved. After receiving the models, they were given their own dedicated space where patrons are free to use those models already out and are provided a list of the models in storage. The biggest takeaways from this experience is do not give up on your proposals if rejected and find other avenues to actuate your vision; physical items are still necessary in libraries; and look outside of your immediate sphere to build connections. </p

Ligand-Enhanced Abiotic Iron Oxidation and the Effects of Chemical versus Biological Iron Cycling in Anoxic Environments

This study introduces a newly isolated, genetically tractable bacterium (Pseudogulbenkiania sp. strain MAI-1) and explores the extent to which its nitrate-dependent iron-oxidation activity is directly biologically catalyzed. Specifically, we focused on the role of iron chelating ligands in promoting chemical oxidation of Fe­(II) by nitrite under anoxic conditions. Strong organic ligands such as nitrilotriacetate and citrate can substantially enhance chemical oxidation of Fe­(II) by nitrite at circumneutral pH. We show that strain MAI-1 exhibits unambiguous biological Fe­(II) oxidation despite a significant contribution (∼30–35%) from ligand-enhanced chemical oxidation. Our work with the model denitrifying strain Paracoccus denitrificans further shows that ligand-enhanced chemical oxidation of Fe­(II) by microbially produced nitrite can be an important general side effect of biological denitrification. Our assessment of reaction rates derived from literature reports of anaerobic Fe­(II) oxidation, both chemical and biological, highlights the potential competition and likely co-occurrence of chemical Fe­(II) oxidation (mediated by microbial production of nitrite) and truly biological Fe­(II) oxidation

Cr Isotopes and the Engineered Attenuation of Cr(VI)-Rich Runoff

The leaching of lateritic soils can result in drainage waters with high concentrations of Cr­(VI). Such Cr­(VI)-rich waters have developed in streams that drain lateritic soils in Central Sulawesi Island, Indonesia. Chromium in this lateritic drainage system is removed by reduction of Cr­(VI) to Cr­(III) through two faucets delivering an FeSO4 solution to the drainage waters. Cr stable isotope compositions from both water and sediment samples along the drainage path were used to evaluate the efficacy of this remediation strategy. Overall, dissolved [Cr­(VI)] decreased moving downstream, but there was an increase in [Cr­(VI)] after the first faucet that was effectively removed at the second faucet. This intermittent increase in [Cr­(VI)] was the likely result of oxidative remobilization of sediment Cr­(III) through reaction with Mn oxides. Cr isotope distributions reflect near quantitative reduction associated with the FeSO4 faucets but also reveal that Cr isotope fractionation is imparted due to Cr redox cycling, downstream. During this redox cycling, fractionation appeared to accompany oxidation, with the product Cr­(VI) becoming enriched in 53Cr relative to the reactant Cr­(III) with an apparent fractionation factor of 0.7 ± 0.3‰. This study suggests that while FeSO4 effectively removes Cr­(VI) from the drainage, the presence of Mn oxides can confound attenuation and improvements to Cr­(VI) remediation should consider means of preventing the back reaction of Cr­(III) with Mn oxides