This report describes service-learning in a first-year majors biology course in which students serve throughout the semester with community partners for an average of 25 hours/student. All of the ...partnerships are based on providing engaging hands-on biology activities for youth in underserved urban areas surrounding the campus. Students in the course have designed new lessons and activities, supported biology labs, mentored younger students, and facilitated afterschool science clubs. Throughout the course, integration between the students' service experience in the community and their learning in the course is emphasized. This is accomplished in multiple ways including class discussion, group activities, feedback from the instructor and teaching assistant, and weekly blogs. A three-year average of anonymous university-wide course evaluations suggested that students in this service-learning course considered their biology course to be highly rigorous. In both blogs and anonymous surveys students reported that their service and its integration with the course not only advanced their professional skills and sense of community engagement, but also enhanced their learning in biology.
Contamination of groundwater with chlorinated ethenes is common and represents a threat to drinking water sources. Standard anaerobic bioremediation methods for the highly chlorinated ethenes PCE and ...TCE are not always effective in promoting complete degradation. In these cases, the target contaminants are degraded to the daughter products DCE and/or vinyl chloride. This creates an additional health risk, as vinyl chloride is even more toxic and carcinogenic than its precursors. New treatment modalities are needed to deal with this widespread environmental problem. We describe successful bioremediation of a large, migrating, dilute vinyl chloride plume in Massachusetts with an aerobic biostimulation treatment approach utilizing both oxygen and ethene. Initial microcosm studies showed that adding ethene under aerobic conditions stimulated the rapid degradation of VC in site groundwater. Deployment of a full‐scale treatment system resulted in plume migration cutoff and nearly complete elimination of above‐standard VC concentrations.
In the recent report,
Vision and Change in Undergraduate Biology Education: A Call to Action,
the American Association for the Advancement of Science laid out a blueprint for reforming undergraduate ...biology education. A key component of the vision is ensuring that all students understand certain core concepts that are necessary for biological literacy, and that they are able to demonstrate a set of core competencies in disciplinary practice.
The core concepts and competencies were integrated into every aspect of a first year Inquiries in Biology course at Northeastern University. This course is offered to students majoring in Biology, Biochemistry, and Behavioral Neuroscience who have Advanced Placement credit for General Biology. The class is small (35 students), and is organized largely in a seminar format with no textbook and very minimal lecturing. However, the integration strategies presented here should be applicable to larger classes, as well as classes that are more lecture-focused.
Vitamin K-dependent γ-glutamyl carboxylase catalyzes the conversion of glutamyl residues to γ-carboxyglutamate. Its substrates include vertebrate proteins involved in blood coagulation, bone ...mineralization, and signal transduction and invertebrate ion channel blockers known as conotoxins. Substrate recognition involves a recognition element, the γ-carboxylation recognition site, typically located within a cleavable propeptide preceding the targeted glutamyl residues. We have purified two novel γ-carboxyglutamate-containing conotoxins, Gla-TxX and Gla-TxXI, from the venom of Conus textile. Their cDNA-deduced precursors have a signal peptide but no apparent propeptide. Instead, they contain a C-terminal extension that directs γ-carboxylation but is not found on the mature conotoxin. A synthetic 13-residue “postpeptide” from the Gla-TxXI precursor reduced the K m for the reaction of the Conus γ-carboxylase with peptide substrates, including FLEEL and conantokin-G, by up to 440-fold, regardless of whether it was positioned at the N- or C-terminal end of the mature toxin. Comparison of the postpeptides to propeptides from other conotoxins suggested some common elements, and amino acid substitutions of these residues perturbed γ-carboxylation of the Gla-TxXI peptide. The demonstration of a functional and transferable C-terminal postpeptide in these conotoxins indicates the presence of the γ-carboxylation recognition site within the postpeptide and defines a novel precursor structure for vitamin K-dependent polypeptides. It also provides the first formal evidence to prove that γ-carboxylation occurs as a post-translational rather than a cotranslational process.
Review of: Be the Change: Saving the World with Citizen Science; Chandra Clarke; (2013). CreateSpace Independent Publishing Platform, Seattle, WA. 85 pages.
Review of: Be the Change: Saving the World with Citizen Science; Chandra Clarke; (2013). CreateSpace Independent Publishing Platform, Seattle, WA. 85 pages.
The proteasome is a multi-protein complex that degrades cellular proteins as well as foreign proteins destined for antigen presentation. The latter function involves the immunoproteasome, in which ...several proteasome subunits are exchanged for γ-interferon-induced subunits. The transporter associated with antigen processing (TAP) transports proteasome-generated peptides across the membrane of the endoplasmic reticulum (ER) prior to presentation on the plasma membrane. We demonstrate interactions between the cytoplasmic domains of TAP subunits and subunits of both the proteasome and the immunoproteasome, suggesting direct targeting of antigenic peptides to the ER via a TAP–proteasome association. We also show interaction between one of the cytoplasmic domains of P-glycoprotein and a proteasome subunit, but not the corresponding immunoproteasome subunit, suggesting a possible role for P-glycoprotein in the transport of proteasome-derived peptides.
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