The deposition of Eumelanin in human skin (and thus the light dark variation of human skin) generally trends to provide greater pigmentation closer to the equator (where there is more cancer causing Ultraviolet light) and less deposition at greater latitudes (where less UV light is provided by the sun). If humans variation in this factor is based upon the deposition of eumelanin providing a survival advantage in areas and not so much of an advantage in other areas, then we could say this variation across the habitat of humanity (the land of Earth) is an example of…

Dr. Bennett believes that a newly synthesized compound, Xylozine, may be effective in reducing the severity of symptoms in patients with seasonal allergies. Preliminary tests in the lab have shown that Xylozine can counteract the effects of certain allergens. Dr. Bennett’s clinic has a diverse group of patients with varying levels of seasonal allergy severity. He also has access to a placebo that is indistinguishable from Xylozine in appearance and taste. Given Dr. Bennett’s goal and the fact that he can supply patients with either Xylozine or a look-alike placebo, which study design would generate the cleanest evidence for the drug’s effectiveness? [1] Why is it essential that neither the participants nor the clinic staff know who receives Xylozine versus placebo in the study you design? [2] Imagine some participants begin taking over-the-counter antihistamines during the trial without telling the research team. According to the “dirty data” categories in the handout, which problem does this introduce? [3] If Dr. Bennett reviews the symptom diaries and pays more attention to participants who report improvement while overlooking those who do not, which “dirty data” category from the handout is most likely at play? [4]  Which specific feature of the proposed study is designed to protect the results from being distorted by the placebo effect? [5] After the study, a marketing brochure quotes two participants who claimed Xylozine “changed my life” and ignores the majority who reported little difference. Which dirty-data category best describes this selective storytelling? [6]

Dr. Reynolds recently started using a novel drug to treat patients with chronic migraines. She noticed that patients with exceptionally severe migraines, averaging around 20 headache days a month, reported a drop to about 14 headache days a month after starting the drug. However, patients with around eight headache days a month saw no change after beginning the medication. Dr. Reynolds is enthusiastic about the results for the severely affected group, believing the drug made a significant difference for them.  Which type of “dirty data” best explains why the patients with the most severe migraines (≈ 20 headache days → ≈ 14) appeared to benefit, while those with milder migraines showed no change after starting the drug? [1] Why is the pattern in Dr. Reynolds’ results an example of the dirty-data phenomenon you chose in Question 1? [2] How might this statistical phenomenon influence Dr. Reynolds’ perception of the drug’s effectiveness? [3] Suppose Dr. Reynolds repeats the study and includes a control group that receives an identical-looking pill with no active ingredient. If both groups improve equally, which source of dirty data was most likely responsible for the original apparent benefit? [4]  

Mott cells and flame cells are characteristics of patients with: 

The accumulation of glucocerebrosides in the RES and CNS is seen in patients with:

The tubule structures of the nephron are anatomically immediately next to each other such that one tube can encourage the physiological process of an adjacent tube.  This is a description of

Identify the region in blue being pointed to. _______

O-UE Stem-changing verbs. Complete the blank with the correct form the O-UE stem changing verb in parenthesis.Yo  ocho horas. (dormir)

Complete the sentence with the correct irregular ‘yo’ form of the verb in parenthesis. Modelo: You see: Yo _________ la tarea. (hacer). You write: hagoYo la radio. (oír) 

Complete the sentence with the correct irregular ‘yo’ form of the verb in parenthesis. Modelo: You see: Yo _________ la tarea. (hacer). You write: hagoYo de mi casa a las 8am. (salir)