Forensic Biology
1. For Topic 1 of the Week 1 Discussion, you chose a certain factoid regarding SARS-CV-2 and COVID-19. (READ ABOVE)…..You will now take your topic and approach it using the two types of scientific inquiry (Study Guide): Observational and experimental.
Task: a) Provide a detailed narrative of how your topic could be investigated using observational and experimental studies; b) include the pros and cons of each type of study you chose for your topic – make them specific to your topic; and c) address whether both types of experiments are part of the scientific method.
Observational:
Experimental:
Note: The three most popular types of observational studies are below.
Cohort Study: the investigator records whether each study participant is exposed and then follows the participants to see if they develop a condition, exhibit a certain behavior, etc. unexposed participants serve as the comparison group.
Case-Control Study: the investigator enrolls a group people with the disease of interest and a group without the disease as a comparison group. The investigators the compare previous exposures between the groups in an attempt to look for an association.
Cross-sectional Study: investigators enroll people from a certain population and measure exposures and outcome (e.g., disease development) simultaneously. Usually limited to providing information about prevalence of a disease in the population rather than cause and effect.
2. Primate research centers in several states use a central facility in State X to receive and quarantine the macaque monkeys used in their research studies. From January to June of 2021, the central facility received a total of 200 monkeys. In March, rumors began to spread of sick monkeys in at least three different states. These monkeys were eventually confirmed to have ebola virus. Shipment to and from the central facility were halted in June and monkeys in the facility were tested. Of the 300 monkeys in the facility in June, 225 tested positive for the virus.
Up to 75% of the sick monkeys sent to customers have died. In a panic, the center director knows he needs to find a reliable way to test the macaques before they are shipped across the country. The early symptoms, such as fever, are not specific to ebola virus infection.
You are chosen to devise an antibody test that reacts with ebola virus antigens: a green color is produced if ebola is present in the urine sample. You are ready to assess specificity and sensitivity. The 300 monkeys in the facility are used for this purpose.
Your test results: 175 monkeys tested positive and 125 tested negative.
a) Calculate the sensitivity and specificity of this test. Do you think it should be used to screen new arrivals?
b) You also used the new test with many different substances, and to your surprise received a positive result when testing against malaria cultures, a human rhinovirus and your grandma’s ginger spice cake. Is this a concern for either the sensitivity or specificity of your assay?
3. Describe a presumptive blood test and a confirmatory test. You will have to describe every procedure used in your final project laboratory reports. Practice it here. Briefly describe your chosen assays and how they work.
a)
b)
4. a) A 250-lb male consumed five glasses of whiskey in a 3-hour period of time. Determine his BAC.
b) A 120-lb female wants to know how much wine will take her to the legal limit of 0.08%. Determine how many glasses of wine she can drink over 2 hours.
5. A toxicology report on a 3-year-old showed the presence of the drug selegiline at a plasma concentration of 5 ng/mL. As the toxicologist, what might you write in a laboratory report about this finding? Might anyone else be interested in this result?
6. Why is acid phosphatase test only presumptive for the presence of seminal fluid? Consider the biological aspects of the test.
7. You now have an idea how fingerprints develop. Is the premise that fingerprints are unique valid? Defend your position.
