Hallo and welcome to the course on evidence based toxicology. My name is Lena Smirnova, and I am here in Johns Hopkins School of Public Health. And I will teach you this course, together with Professor Dr Thomas Hartung, and we're both allocated in Johns Hopkins University, Bloomberg School of Public Health. And now I will give you an introduction to the course, and also introduction to the first module of this course. So this course will teach you, what is evidence-based approaches in general, and how you can apply those evidence-based approaches to toxicology. And it's really young field, even if it's basic toxicology and you will learn how we adapt even if the base approaches from medicine to toxicology. So EBM to EBT. In the first lesson on the first module, I will introduce you the course. We'll go through the lectures or lessons, and also explain the assignments and exams and what to expect from the course and what you will learn from it. And the second lesson on this module, you will learn about shortcomings of current toxicological approaches. So what are the problems in vitro experimentations and how we can overcome those problems or shortcomings with evidence-based approaches? The lessons will be given to you by Doctor Martha Stevens, who is former Director of Evidence-based Toxicology Collaboration here at Johns Hopkins University. He will go step by step in the old shortcomings, he will identify and explain you what are they and how to overcome them, using the evidence-based approaches. So for example, narrative-free view, what does narrative free view? And shortcomings of narrative-free view is subjectivity of it, narrative interviews usually written by experts in the field. So some guy who is really known in the field very well and summarize, putting together all of the information he thinks he found. But usually it's really subjective, because he tries to narrow to the knowledge he has, and he does a systematic analysis of the whole entire budget of the existing literature. So therefore, these narrative free views have some bias and subjectivity. And evidence-based approaches can help overcome these issues by performing systematic review, and other shortcomings of toxicology or actually entire signs is buyers, we introduce several buyers during performing our tests, performance buyers, reporting buyers and so on. For example, if it's a performance bias. Definition is working with any mouth, treated group versus control group. If the clinician who is working on this experiment is blinded and she doesn't know which is treated and control group or she knows. If she knows, she might treat them differently, introducing performance bias in the experiment. Or reporting bias, we tend to report positive results, we don't publish negative results. We are cherry picking very often in our experiments. Or we're trying to follow the hypothesis we generated from the beginning. And by doing so, we introduce enormous important bias in the publications. So in all this can be overcome just evidence-based approaches. So this is the main topic of the lesson one, module one. And I hope you will enjoy that, thank you.