Oguma A.Y.,University of Louisiana at Lafayette |
Oguma A.Y.,Massasoit Community College |
Klerks P.L.,University of Louisiana at Lafayette
Ecotoxicology | Year: 2015
Much work has focused on the effects of metal-contaminated sediment on benthic community structure, but effects on ecosystem functions have received far less attention. Decomposition has been widely used as an integrating metric of ecosystem function in lotic systems, but not for lentic ones. We assessed the relationship between low-level sediment lead (Pb) contamination and leaf-litter decomposition in a lentic system. We measured 30-day weight loss in 30 litter-bags that were deployed along a Pb-contamination gradient in a cypress-forested lake. At each deployment site we also quantified macrobenthos abundance, dissolved oxygen, water depth, sediment organic content, sediment silt/clay content, and both total sediment and porewater concentrations of Cd, Cu, Ni, Pb and Zn. Principal components (PC) analysis revealed a negative relationship between Pb concentration and benthic macroinvertebrate abundance, and this covariation dominated the first PC axis (PC1). Subsequent correlation analyses revealed a negative relationship between PC1 and percent leaf-litter loss. Our results indicate that leaf-litter decomposition was related to sediment Pb and benthic macroinvertebrate abundance. They also showed that ecosystem function may be affected even where sediment Pb concentrations are mostly below threshold-effects sediment quality guidelines—a finding with potential implications for sediment risk assessment. Additionally, the litter-bag technique used in this study showed promise as a tool in risk assessments of metal-contaminated sediments in lentic systems. © 2015, Springer Science+Business Media New York.
Jackson K.L.,University of Miami |
Eberli G.P.,University of Miami |
Amelung F.,University of Miami |
McFadden M.A.,Massasoit Community College |
And 3 more authors.
Geology | Year: 2014
Sediment cores from Karagan Lagoon in southeastern Sri Lanka retrieved deposits from the A.D. 2004 Indian Ocean tsunami and older similar deposits that provide evidence for a tsunami 2417 ± 152 cal. (calendar) yr B.P. to 2925 ± 98 cal. yr B.P., and for six tsunamis between 4064 ± 128 cal. yr B.P. and 6665 ± 110 cal. yr B.P., a period for which the sediment record appears continuous. Radiocarbon dating indicates that the recurrence interval is variable, ranging from 181-517 yr to 1045 ± 334 yr, with a mean recurrence interval of 434 ± 40 yr during the ca. 4000-7000 cal. yr B.P. continuous interval. Assuming that these tsunamis were generated by giant earthquakes along the Sumatra-Andaman subduction zone, a reasonable assumption for this far-field transoceanic location, this record extends the giant-earthquake history for the Indian Ocean region. The longest recurrence interval of more than 1000 yr implies that earthquakes along the subduction zone may reach twice the size of the 2004 earthquake. © 2014 Geological Society of America.
Truong-Bolduc Q.C.,Harvard University |
Bolduc G.R.,Massasoit Community College |
Medeiros H.,Harvard University |
Vyas J.M.,Harvard University |
And 2 more authors.
Infection and Immunity | Year: 2015
We previously identified the protein Tet38 as a chromosomally encoded efflux pump of Staphylococcus aureus that confers resistance to tetracycline and certain unsaturated fatty acids. Tet38 also contributes to mouse skin colonization. In this study, we discovered a novel regulator of tet38, named tetracycline regulator 21 (TetR21), that bound specifically to the tet38 promoter and repressed pump expression. A ΔtetR21 mutant showed a 5-fold increase in tet38 transcripts and an 8-fold increase in resistance to tetracycline and fatty acids. The global regulator MgrA bound to the tetR21 promoter and indirectly repressed the expression of tet38. To further assess the full role of Tet38 in S. aureus adaptability, we tested its effect on host cell invasion using A549 (lung) and HMEC-1 (heart) cell lines. We used S. aureus RN6390, its Δtet38, ΔtetR21, and ΔmgrA mutants, and a Δtet38 ΔtetR21 double mutant. After 2 h of contact, the Δtet38 mutant was internalized in 6-fold-lower numbers than RN6390 in A549 and HMEC-1 cells, and the ΔtetR21 mutant was internalized in 2-fold-higher numbers than RN6390. A slight increase of 1.5-fold in internalization was found for the ΔmgrA mutant. The growth patterns of RN6390 and the ΔmgrA and ΔtetR21 mutants within A549 cells were similar, while no growth was observed for the Δtet38 mutant. These data indicate that the Tet38 efflux pump is regulated by TetR21 and contributes to the ability of S. aureus to internalize and replicate within epithelial cells. © 2015, American Society for Microbiology. All Rights Reserved.
Golen J.A.,University of Massachusetts Dartmouth |
McDonald K.J.,Massasoit Community College |
Manke D.R.,University of Massachusetts Dartmouth
Acta Crystallographica Section E: Crystallographic Communications | Year: 2015
The title compound, C10H15NO, has two molecules in the asymmetric unit. Each molecule has a near-planar C8NO unit excluding H atoms and the terminal methyl groups on the diethylamino groups, with mean deviations from planarity of 0.036 and 0.063Å. In the crystal, hydrogen bonding leads to four-membered O - H⋯O - H⋯O - H·· rings. No π-π interactions were observed in the structure.
Agency: NSF | Branch: Standard Grant | Program: | Phase: ADVANCED TECH EDUCATION PROG | Award Amount: 199.94K | Year: 2012
This project is establishing a new biotechnology degree option and a new biotechnology certificate to respond to life science, allied health and biotechnology industry needs for more highly skilled, entry level laboratory technicians and is working closely with industry partners and industry associations to develop these programs. The new biotechnology degree option and biotechnology certificate are designed to incorporate relevant, real world applications of laboratory techniques that are required skills for biotechnicians. The courses being developed have sufficient rigor to also offer transfer credit to a four-year program.
Intellectual Merit: Early undergraduate research has been shown to improve retention and academic success in science, technology, engineering, and mathematics (STEM) disciplines and workforce competitiveness; however, the community college students this project targets are often at a disadvantage in gaining these experiences due to lack of institutional capacity or financial and time constraints common among students at community colleges. To overcome this gap, the college is infusing courses developed in support of this project, along with existing science and mathematics curriculum, with inquiry-based learning methodologies and research like laboratory exercises that promote success in biotechnology studies and other STEM disciplines. The college is also creating new opportunities for students to engage in workplace internships and on campus summer research that provide more intensive experiences and build practical skills. Professional development for faculty enhances teaching capacity to integrate inquiry based learning into science and mathematics curriculum. Acquisition of industry standard equipment provides the laboratory configuration necessary to deliver the biotechnology programs and develop industry required competencies in students. New courses developed in support of these programs and revitalized curricula throughout the Division of Science and Mathematics are grounded in research-like experiences that provide a means to engage students in learning in a way that helps them to be academically successful and teaches them the scientific inquiry skills needed for a truly comprehensive technical training.
Broader Impact: This undergraduate research program is a model for other community colleges that are similarly challenged to provide research driven education to biotechnology and STEM students. To ensure the broader impact of the project, the college has developed a thorough dissemination plan to inform stakeholders at the local, regional, and national level on outcomes related to this initiative. Regional and state distribution channels include membership in consortia of community colleges and state universities that have the established goals of sharing experiences and promoting best practices between institutions and among colleagues. As the recipient of a model program endorsement from the Massachusetts Governors STEM Advisory Council for its work in improving retention, graduation, and transfer rates among science majors, the college has the established credentials and support from appropriate authorities to ensure that findings from this project are both heard and heeded by institutions across the Commonwealth. On a national level, the plan is to promote the findings through accessible channels such as the annual NSF ATE conference and ATE Central, as well as seek opportunities to present findings through presentations and posters at academic conferences.