LD50 redirects here. For other uses, see LD50 (disambiguation) . In toxicology, the median lethal dose, LD50 (abbreviation for  lethal dose, 50%), LC50 (lethal concentration, 50%) or LCt50 is a measure of the lethal dose of a toxin, radiation, or pathogen.
In an employee-initiated review system, employees are informed that they can ask for a review from their manager. This type of on-demand appraisal is not meant to replace a conventional review process. Rather, it can be used to promote an attitude of self-management among workers.f a small business uses merit-based increases, the appraisal form would include a rating of the employee on certain tasks. If skill-based pay is used, the appraisal would list skills acquired and level of competency.
1 Critical appraisal is a systematic process used to identify the strengths and weaknesses of a research article. 2  Critical appraisal provides a basis for decisions on whether to use the results of a study in clinical practice. 3  Different study designs are prone to various sources of systematic bias.n the process of critically appraising a research article, one important step is to check for a declaration about the source of funding for the study and, if a potential conflict of interest had been identified for a statement about how this conflict was managed.