College of Letters & Science
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The College of Letters and Science, the largest center for learning, teaching and research at Montana State University, offers students an excellent liberal arts and sciences education in nearly 50 majors, 25 minors and over 25 graduate degrees within the four areas of the humanities, natural sciences, mathematics and social sciences.
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Item Community Engaged Cumulative Risk Assessment of Exposure to Inorganic Well Water Contaminants, Crow Reservation, Montana(2018-01) Eggers, Margaret J.; Doyle, John T.; Lefthand, M. J.; Young, Sara L.; Moore-Nall, Anita L.; Kindness, L.; Medicine, R. O.; Ford, Tim E.; Dietrich, E.; Parker, Albert E.; Hoover, J. H.; Camper, Anne K.An estimated 11 million people in the US have home wells with unsafe levels of hazardous metals and nitrate. The national scope of the health risk from consuming this water has not been assessed as home wells are largely unregulated and data on well water treatment and consumption are lacking. Here, we assessed health risks from consumption of contaminated well water on the Crow Reservation by conducting a community-engaged, cumulative risk assessment. Well water testing, surveys and interviews were used to collect data on contaminant concentrations, water treatment methods, well water consumption, and well and septic system protection and maintenance practices. Additive Hazard Index calculations show that the water in more than 39% of wells is unsafe due to uranium, manganese, nitrate, zinc and/or arsenic. Most families’ financial resources are limited, and 95% of participants do not employ water treatment technologies. Despite widespread high total dissolved solids, poor taste and odor, 80% of families consume their well water. Lack of environmental health literacy about well water safety, pre-existing health conditions and limited environmental enforcement also contribute to vulnerability. Ensuring access to safe drinking water and providing accompanying education are urgent public health priorities for Crow and other rural US families with low environmental health literacy and limited financial resources.Item Surface micropattern reduces colonization and medical device-associated infections(2017-11) Xu, Binjie; Wei, Qiuhua; Mettetal, M. Ryan; Han, Jie; Rau, Lindsey; Tie, Jinfeng; May, Rhea M.; Pathe, Eric T.; Reddy, Shravanthi T.; Sullivan, Lauren; Parker, Albert E.; Maul, Donald H.; Brennan, Anthony B.; Mann, Ethan E.PURPOSE: Surface microtopography offers a promising approach for infection control. The goal of this study was to provide evidence that micropatterned surfaces significantly reduce the potential risk of medical device-associated infections. METHODOLOGY: Micropatterned and smooth surfaces were challenged in vitro against the colonization and transference of two representative bacterial pathogens - Staphylococcus aureus and Pseudomonas aeruginosa. A percutaneous rat model was used to assess the effectiveness of the micropattern against device-associated S. aureus infections. After the percutaneous insertion of silicone rods into (healthy or immunocompromised) rats, their backs were inoculated with S. aureus. The bacterial burdens were determined in tissues under the rods and in the spleens. RESULTS: The micropatterns reduced adherence by S. aureus (92.3 and 90.5 % reduction for flat and cylindrical surfaces, respectively), while P. aeruginosa colonization was limited by 99.9 % (flat) and 95.5 % (cylindrical). The micropatterned surfaces restricted transference by 95.1 % for S. aureus and 94.9 % for P. aeruginosa, compared to smooth surfaces. Rats with micropatterned devices had substantially fewer S. aureus in subcutaneous tissues (91 %) and spleens (88 %) compared to those with smooth ones. In a follow-up study, immunocompromised rats with micropatterned devices had significantly lower bacterial burdens on devices (99.5 and 99.9 % reduction on external and internal segments, respectively), as well as in subcutaneous tissues (97.8 %) and spleens (90.7 %) compared to those with smooth devices. CONCLUSION: Micropatterned surfaces exhibited significantly reduced colonization and transference in vitro, as well as lower bacterial burdens in animal models. These results indicate that introducing this micropattern onto surfaces has high potential to reduce medical device-associated infections. KEYWORDS: hospital-acquired infections; infections; medical devices; micropatternsItem Who Goes in and Out of the Hospital Patient Room?(2017-06) Arbogast, James W.; Quinn, Jeff; Clark, Tracy; Moore, Lori; Thompson, Maria; Wagner, Pamela; Young, Elizabeth; Parker, Albert E.BACKGROUND: The objective of this study was to determine what percentage of entries and exits (E/E) in and out of the patient room should be attributed to healthcare workers (HCWs) in a wide variety of hospital units. This is a critical question for hospitals considering an automated monitoring system (AMS) to measure hand hygiene performance (HHP) as a complement to data from visual observation. HCWs often implicate others and do not perceive a need to change their HH behavior because they are convinced that visitors, patients, and others are responsible for very low HHP data. METHODS: Events (defined as patient room E/E) were observed and recorded by nurses not employed by the hospital. Observations were made in US and Canadian hospital units including emergency, ICU, medical surgical, oncology, and pediatrics. Observers classified events by: HCWs (e.g., nursing staff, aides, doctors, EVS, etc.), patients plus visitors, and other (e.g., clergy, hospice workers). Logistic regression was used to determine who was responsible for the most E/E events by category of individuals. RESULTS: Observers recorded a total of 14,876 E/E events in 29 units of 16 hospitals with units varying in size from 10 to 41 beds. 84.3% of all E/E were attributed to HCWs; 15.0% were from patients plus visitors and 0.7% from others. The odds are 6 to 1 that an E/E into a patient room is by a HCW (P < .0005). Pediatric units had the lowest percentage of HCWs E/E (76.7% total) CONCLUSIONS: This study demonstrates HCWs account for the greatest proportion of hospitalized patient room E/E. Further, the data show that others share a very small percentage of room E/E countering the argument that those individuals are responsible for the low unit HHP measured by AMS. This study demonstrates that other categories of individuals are not a deterrent to increasing unit-level HHP.Item Symmetry breaking clusters in soft clustering decoding of neural codes(2010-02) Parker, Albert E.; Dimitrov, Alexander G.; Gedeon, TomasInformation-based distortion methods have been used successfully in the analysis of neural coding problems. These approaches allow the discovery of neural symbols and the corresponding stimulus space of a neuron or neural ensemble quantitatively, while making few assumptions about the nature of either the code or of relevant stimulus features. The neural codebook is derived by quantizing sensory stimuli and neural responses into a small set of clusters, and optimizing the quantization to minimize an information distortion function. The method of annealing has been used to solve the corresponding high-dimensional nonlinear optimization problem. The annealing solutions undergo a series of bifurcations, which we study using bifurcation theory in the presence of symmetries. In this contribution we describe these symmetry breaking bifurcations in detail, and indicate some of the consequences of the form of the bifurcations. In particular, we show that the annealing solutions break symmetry at pitchfork bifurcations, and that subcritical branches can exist. Thus, at a subcritical bifurcation, there are local information distortion solutions which are not found by the method of annealing. Since the annealing procedure is guaranteed to converge to a local solution eventually, the subcritical branch must turn and become optimal at some later saddle-node bifurcation, which we have shown occur generically for this class of problems. This implies that the rate distortion curve, while convex for noninformation-based distortion measures, is not convex for information-based distortion methods.