A case study of adults in college who developed an experiential learning portfolio

This single-case study provides a description and explanation of selected adult students' perspectives on the impact that the development of an experiential learning portfolio had on their understanding of their professional and personal lives. The conceptual framework that undergirded the study included theoretical and empirical studies on adult learning, experiential learning, and the academic quality of nontraditional degree programs with a portfolio component. The study employed qualitative data collection techniques of individual interviews, document review, field notes, and researcher journal. A purposive sample of 8 adult students who completed portfolios as a component of their undergraduate degrees participated in the study. The 4 male and 4 female students who were interviewed represented 4 ethnic/racial groups and ranged in age from 32 to 55 years. Each student's portfolio was read prior to the interview to frame the semi-structured interview questions in light of written portfolio documents. ^ Students were interviewed twice over a 3-month period. The study lasted 8 months from data collection to final presentation of the findings. The data from interview transcriptions and student portfolios were analyzed, categorized, coded, and sorted into 4 major themes and 2 additional themes and submitted to interpretive analysis. ^ Participants' attitudes, perceptions, and opinions of their learning from the portfolio development experience were presented in the findings, which were illustrated through the use of excerpts from interview responses and individual portfolios. The participants displayed a positive reaction to the learning they acquired from the portfolio development process, regardless of their initial concerns about the challenges of creating a portfolio. Concerns were replaced by a greater recognition and understanding of their previous professional and personal accomplishments and their ability to reach future goals. Other key findings included (a) a better understanding of the role work played in their learning and development, (b) a deeper recognition of the impact of mentors and role models throughout their lives, (c) an increase in writing and organizational competencies, and (d) a sense of self-discovery and personal empowerment. ^

The 4-aza-S-ribosyl-L-homocysteine derivatives and the related gamma-lactam and azahemiacetal analogs: Synthesis, inhibition and quorum sensing activity

Quorum sensing (QS) is a population-dependent signaling process bacteria use to control multiple processes including virulence, critical for establishing infection. There are two major pathways of QS systems. Type 1 is species specific or intra-species communication in which N-acylhomoserine lactones (Gram-negative bacteria) or oligopeptides (Gram-positive bacteria) are employed as signaling molecules (autoinducer one). Type 2 is inter-species communication in which S-4,5-dihydroxy-2,3-pentanedione (DPD) or its borate esters are used as signaling molecules. The DPD is biosynthesized by LuxS enzyme from S-ribosylhomocysteine (SRH). Recent increase in prevalence of bacterial strains resistant to antibiotics emphasizes the need for the development of new generation of antibacterial agents. Interruption of QS by small molecules is one of the viable options as it does not affect bacterial growth but only virulence, leading to less incidence of microbial resistance. Thus, in this work, inhibitors of both N-acylhomoserine lactone (AHL) mediated intra-species and LuxS enzyme, involved in inter-species QS are targeted. The γ-lactam and their reduced cyclic azahemiacetal analogs, bearing the additional alkylthiomethyl substituent, were designed and synthesized targeting AHL mediated QS systems in P. aeruginosa and Vibrio harveyi. The γ-lactams with nonylthio or dodecylthio chains acted as inhibitors of las signaling in P. aeruginosa with moderate potency. The cyclic azahemiacetal with shorter propylthio or hexylthio substituent were found to strongly inhibit both las and rhl signaling in P. aeruginosa at higher concentrations. However, lactam and their azahemiacetal analogs were found to be inactive in V. harveyi QS systems. The 4-aza-S-ribosyl-L-homocysteine (4-aza-SRH) analogs and 2-deoxy-2-substituted-S-ribosyl-L-homocysteine analogs were designed and synthesized targeting Bacillus subtilis LuxS enzyme. The 4-aza-SRH analogs in which oxygen in ribose ring is replaced by nitrogen were further modified at anomeric position to produce pyrrolidine, lactam, nitrone, imine and hemiaminal analogs. Pyrrolidine and lactam analogs which lack anomeric hydroxyl, acted as competitive inhibitors of LuxS enzyme with KI value of 49 and 37 µM respectively. The 2,3-dideoxy lactam analogs were devoid of activity. Such findings attested the significance of hydroxyl groups for LuxS binding and activity. Hemiaminal analog of SRH was found to be a time-dependent inhibitor with IC50 value of 60 µM.