Novel Framework for Improving the Correctness of Reference Answers to Enhance Results of ASAG Systems.

Usage of online learning platforms increases day by day and henceforth, there emerges the need for automated grading systems to assess the learner's performance. Evaluating these answers demands for a well-grounded reference answer which aids a strong foundation for better grading. Since reference answers impacts the exactness of grading answers of learners, its correctness remains a great concern. A framework that addresses the reference answer exactness in Automated Short Answer Grading (ASAG) systems was developed. This framework includes material content acquisition, clustering collective content, expert answer as key components which was later fed to a zero-shot classifier for a strong reference answer generation. Then, the computed reference answers along with student answers and questions from Mohler dataset were fed to an ensemble of transformers to produce relevant grades. The aforementioned models' RMSE and correlation values were compared against the past values of the dataset. Based on the observations made, this model outperforms the previous approaches.

An oxysterol signalling pathway mediated by the nuclear receptor LXR alpha.

Cholesterol and its oxysterol congeners are important constituents of cell membranes and function as intermediates in several crucial biosynthetic pathways. These compounds autoregulate their metabolic fate by end-product repression and activation of downstream catabolism. Although end-product repression by oxysterols is relatively well understood, the mechanism by which these compounds act as positive transcription signalling molecules is unknown. Here we identify a specific group of endogenous oxysterols that activate transcription through the nuclear receptor LXR alpha. Transactivation of LXR alpha by oxysterols occurs at concentrations at which these compounds exist in vivo. The most potent activators also serve as intermediary substrates in the rate-limiting steps of three important metabolic pathways: steroid hormone biosynthesis, bile acid synthesis, and conversion of lanosterol to cholesterol. Our results demonstrate the existence of a nuclear receptor signalling pathway for oxysterols and suggest that LXR alpha may be important as a sensor of cholesterol metabolites.