House Flies: Manure, Media, and Microbes

This study was conducted to determine if there is a difference in bacterial abundance in house flies based on sex and rearing environment (manure versus artificial media) for house flies. This is important in determining the effectiveness of the facilities where the flies are being raised. Although, previous studies have shown differences in bacterial abundance between male and female house flies, it still remains unknown whether there is a discrepancy in bacterial abundance between rearing environments in the lab. We hypothesized that there would be a greater abundance of bacteria in females than males and a greater bacterial abundance in the manure environment than the artificial media. We determined that there was no significant difference between house fly sex or the environments in which they were raised. These results are meaningful because they introduce evidence of forced interaction that could skew the bacterial counts. In the future, the results would be more telling with a larger sample size.

Structural modeling and functional analysis of the essential ribosomal processing protease Prp from Staphylococcus aureus

In Firmicutes and related bacteria, ribosomal large subunit protein L27 is encoded with a conserved N-terminal extension that is removed to expose residues critical for ribosome function. Bacteria encoding L27 with this N-terminal extension also encode a sequence-specific cysteine protease, Prp, which carries out this cleavage. In this work, we demonstrate that L27 variants with an un-cleavable N-terminal extension, or lacking the extension (pre-cleaved), are unable to complement an L27 deletion in Staphylococcus aureus. This indicates that N-terminal processing of L27 is not only essential but possibly has a regulatory role. Prp represents a new clade of previously uncharacterized cysteine proteases, and the dependence of S. aureus on L27 cleavage by Prp validates the enzyme as a target for potential antibiotic development. To better understand the mechanism of Prp activity, we analyzed Prp enzyme kinetics and substrate preference using a fluorogenic peptide cleavage assay. Molecular modeling and site-directed mutagenesis implicate several residues around the active site in catalysis and substrate binding, and support a structural model in which rearrangement of a flexible loop upon binding of the correct peptide substrate is required for the active site to assume the proper conformation. These findings lay the foundation for the development of antimicrobials that target this novel, essential pathway

Nutrient limitation dynamics of a coastal Cape Cod pond : seasonal trends in alkaline phosphatase activity

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution November 2000A bi-weekly seasonal study was conducted in Ashumet Pond (Cape Cod, Massachusetts). The Redfield Ratio (106C:16N:1P) and alkaline phosphatase activity (APA) were utilized in tandem as nutrient deficiency indicators (NDIs) for phytoplankton. The study objective was to evaluate the limiting nutrient status of the pond throughout the growing season. The development of a high throughput method for fluorometrically measuring APA allowed for a large quantity of pond-water samples to be analyzed. The new method utilized a cytofluor, a fluorescence multi-well plate reader, which increased sample throughput by 75% compared to a standard filter fluorometer method. The detection limit, capability to measure APA at different time intervals, and performance at sea were tested. APA measurements made using the cytofluor were comparable to those made using a standard filter fluorometer, thus indicating that the cytofluor is a suitable and preferred replacement to the fluorometer for APA measurements. The presence of alkaline phosphatase, an inducible phospho-hydrolytic enzyme, is commonly used as an NDI diagnostic for phosphate limitation. A nutrient enrichment incubation re-affirmed the use of APA as a robust indicator of phosphate limitation in phytoplankton. APA data indicate that the system experienced episodic periods of phosphate-deficiency, implying that the limiting nutrient regime was not static, but was changeable throughout the growing season. Seasonal trends in dissolved N:P and particulate C:P ratios often contradict the APA results, however, suggesting that the Redfield Ratio is an unreliable indicator of the overall nutrient limitation regime of the pond. The observed discrepancies between C:N:P and APA can be reconciled by taking into account seasonal changes in species composition, which played an important role in driving seasonal APA trends.Funding was provided by: Air Force/University of Massachusetts, Dartmouth (WHOI grant#1503770) and a WHOI Educational Fellowship

Massachusetts Health Reform: A Social Compact and a Bold Experiment

This is the published version

THE IMPACT OF EARLY GOAL DIRECTED SEPSIS BUNDLE SETS IN THE EMERGENCY DEPARTMENT AND THE IMPACT OF SEP-1 COMPLIANCE RATES

Sepsis is a medical emergency that is prevalent throughout hospitals everywhere. Due to the growing crisis, the Centers for Medicare and Medicaid Services (CMS) in collaboration with the Surviving Sepsis Campaign (SSC) adopted core measures for sepsis (SEP-1) which aim at improving overall compliance of evidence-based treatment standards for sepsis. The purpose of this Doctor of Nursing Practice (DNP) project was to determine if incorporating early goal directed sepsis bundles in a rural Midwestern ED was effective in increasing compliance with SEP-1 rates. The secondary purpose evaluated how nursing knowledge, awareness, and compliance with sepsis bundles affects SEP-1 compliance rates. A permutation t test was performed to compare SEP-1 compliance rates for 2019 before any sepsis protocol was implemented, which was 43.9%. A formal sepsis protocol started March 2, 2020, with data collection occurring from March 2020 to March 2021 and included 37 patients, showing an overall ED SEP-1 compliance of 64.9%. No significant findings were seen in nursing compliance with the sepsis bundle. Overall, these findings show that an organized approach and incorporating an early goal directed sepsis protocol to clinical practice guidelines did show an improvement in SEP-1 compliance scores

Online Course Communication and International Student Academic Performance

Online course communication activities can be used to support the social and cognitive needs of students in online courses, but when those students are international students from across the globe studying in the United States where there are language and cultural differences, online learning can be a challenge. The purpose of this study was to examine undergraduate international students’ online course communication behaviors and their academic performance in order to inform quality online course development and delivery. In this qualitative case study, semistructured interviews with 11 undergraduate international students were conducted, online course communication behaviors were observed, and five faculty members were interviewed. Data collection took place virtually via videoconferencing that were recorded and then transcribed in order to code and analyze the data. The community of inquiry model was utilized in creating the instruments used for this study, as well as in the data analysis and conclusion formulation. Findings indicated that while international students performed well in their course communication activities, their learning experiences could have been enhanced by more direct instruction using multimedia, a higher degree of interaction with professors, and more informal social learning opportunities. Higher education institutions in the United States can benefit from this research by implementing recommended instructional design and delivery strategies. Keywords: Community of Inquiry, communication, higher education, interaction, instructional design, instructional strategies, international student, online learnin