Optimizing Sonication and Chromatography Conditions in the Purification of LGN Protein for X-Ray Crystallography

LGN protein is a critical component for the division of mammalian cells, as it functions in the maintenance of cell polarity and the alignment of mitotic spindles during mitosis. In order to optimize a purification scheme for LGN, the protein is first expressed in E. coli, and then is sonicated and centrifuged to respectively lyse and separate the cells and other debris from the expressed proteins. Afterwards, the protein mixture is passed through chromatography columns and the LGN protein is assessed for purity using SDS-PAGE, followed by Western blotting to verify the presence of LGN. The goal of the purification scheme is to attain samples of LGN protein at least 95% pure in order for crystallization conditions to be determined for X-ray crystallography. Western blot detection has verified the expression of LGN and the sonication and chromatography conditions are currently being optimized in order to obtain pure LGN

Which Internal Medicine Clerkship Characteristics Are Associated With Students\u27 Performance on the NBME Medicine Subject Exam? A Multi-Institutional Analysis.

PURPOSE: To identify which internal medicine clerkship characteristics may relate to NBME Medicine Subject Examination scores, given the growing trend toward earlier clerkship start dates. METHOD: The authors used linear mixed effects models (univariable and multivariable) to determine associations between medicine exam performance and clerkship characteristics (longitudinal status, clerkship length, academic start month, ambulatory clinical experience, presence of a study day, involvement in a combined clerkship, preclinical curriculum type, medicine exam timing). Additional covariates included number of NBME clinical subject exams used, number of didactic hours, use of a criterion score for passing the medicine exam, whether medicine exam performance was used to designate clerkship honors, and United States Medical Licensing Examination Step 1 performance. The sample included 24,542 examinees from 62 medical schools spanning 3 academic years (2011-2014). RESULTS: The multivariable analysis found no significant association between clerkship length and medicine exam performance (all pairwise P \u3e .05). However, a small number of examinees beginning their academic term in January scored marginally lower than those starting in July (P \u3c .001). Conversely, examinees scored higher on the medicine exam later in the academic year (all pairwise P \u3c .001). Examinees from schools that used a criterion score for passing the medicine exam also scored higher than those at schools that did not (P \u3c .05). Step 1 performance remained positively associated with medicine exam performance even after controlling for all other variables in the model (P \u3c .001). CONCLUSIONS: In this sample, the authors found no association between many clerkship variables and medicine exam performance. Instead, Step 1 performance was the most powerful predictor of medicine exam performance. These findings suggest that medicine exam performance reflects the overall medical knowledge students accrue during their education rather than any specific internal medicine clerkship characteristics

Control‐value theory: Using achievement emotions to improve understanding of motivation, learning, and performance in medical education: AMEE Guide No. 64

In this AMEE Guide, we consider the emergent theoretical and empirical work on human emotion and how this work can inform the theory, research, and practice of medical education. In the Guide, we define emotion, in general, and achievement emotions, more specifically. We describe one of the leading contemporary theories of achievement emotions, controlvalue theory (Pekrun 2006), and we distinguish between different types of achievement emotions, their proximal antecedents, and their consequences for motivation, learning, and performance. Next, we review the empirical support for controlvalue theory from nonmedical fields and suggest several important implications for educational practice. In this section, we highlight the importance of designing learning environments that foster a high degree of control and value for students. Finally, we end with a discussion of the need for more research on achievement emotions in medical education, and we propose several key research questions we believe will facilitate our understanding of achievement emotions and their impact on important educational outcomes. © 2012 Informa UK Ltd