Name_____________________________________ Block__________________ Date_____________________ Forensics Mystery Blood Typing Lab Scenario: Police are called to a house where they discover a body near the back door. There is a fresh pool of blood by the victimâ€™s head. Officers question the neighbors and learn that a plumber and an electrician made service calls to the house just hours before. They were able to trace both. They recover a shirt with a dark stains from the service van of the plumber and rags with similar dark stains from electricianâ€™s van.Your forensics lab receives the following items to test: Sample 1: Stained cloth from plumberâ€™s van Sample 2: Stained cloth from the electricianâ€™s van Sample 3: Blood collected from under the victimâ€™s head Test Background: The phenolphthalein test is a highly sensitive, being capable of detecting blood spots practically invisible to the eye. In an actual criminal case, a positive phenolphthalein test would be followed by tests to determine the species that produced the blood and if these tests indicate the blood is human, by tests to determine ABO, Rh and other blood groups.There is no point in pursuing typing and species identification procedures if the phenolphthalein test is negative. The phenolphthalein test is not absolutely specific for blood because most plants and some animal cells can also cause a positive reaction. Discussion Questions: 1. Does a positive phenolphthalein test prove that a stain is caused by blood? 2. Does a positive phenolphthalein test prove that a stain is caused by human blood? Procedure 1: 1. Test the shirt and rags to determine if the stains are caused by blood. 2. Place a drop of phenolphthalein/peroxide solution on each stain. 3.Observe if a color change occurs. A purple-violet color reaction indicates that blood (heme) is present (positive reaction). Absence of this reaction indicates that blood is not present. 4. Record your results: Color reaction for Sample 1:_________________________ Color reaction for Sample 2:_________________________ Based on the results of this test, which person, the plumber or the electrician becomes your prime suspect? ____________________________________________________________________________ Additional Information: When confronted, your chief suspect claims to have a nosebleed, thus accounting for the blood stain.Investigators have now been able to recover a blood sample (Sample 4 ) from the suspectâ€™s van. It is suitable for blood typing. You ask and receive a blood sample from the suspect (Sample 5). Proceed to Procedure 2. Test Background: Blood groups are created by molecules present on the surface of red blood cells. The table shows the four ABO phenotypes (â€œblood groupsâ€) present in the human population. When red blood cells carrying one or both antigens are exposed to the corresponding antibodies, they agglutinate; that is, clump together.People usually have antibodies against those red cell antigens that they lack. The ABO Blood Groups Blood Group| Red Cell Antigen (Protein on blood cell)| Serum Antibody (Produced by Body)| A| A| Anti-B| B| B| Anti-A| AB| A and B| Neither| O| Neither| Anti -A and Anti -B| Discussion Questions: 1. How do you determine a personâ€™s blood type? 2. Can a personâ€™s blood type prove or disprove that he/she committed a crime? How? Procedure 2: 1. Add a drop of synthetic anti-A (blue) to the well labeled A. Replace cap. . Always replace the cap on the vial before opening the next vial to prevent cross contamination. . Add a drop of synthetic anti-B (yellow) to the well labeled B. Replace cap. 3. Add a drop of synthetic anti-Rh serum (clear) to the well labeled Rh. Replace cap. 4. Using the dropper vial, place a drop of Sample 3 (the victimâ€™s blood) in each well of the blood typing slide. DO NOT TOUCH THE WELL! 5. Replace the cap on the dropper vial. 6. Using a different color mixing stick for each well (blue for anti-A, yellow for anti-B & white for anti â€“Rh), gently stir the synthetic blood and anti-serum drops for 30 seconds.Remember to discard each mixing stick after a single use to avoid cross contamination. 7. WAIT 60 Seconds. 8. Carefully examine the thin films of liquid mixture left behind. If the film remains uniform in appearance, there is no agglultination (no clumps, negative reaction). If the film as clumps, agglutination has occurred (positive reaction) 9. Determine blood type of the sample using the data table below. Answer yes or no as to whether agglutination occurred in each sample. A positive agglutination reaction indicates blood type. 10. Record the results for each blood sample in the data table.Data Table | Sample 3| Sample 4| Sample 5| Anti-A| | | | Anti-B| | | | Rh| | | | Blood type| | | | 11. Then repeat steps 1-9 for Samples 4 and 5. Record each results on table. 12. Thoroughly rinse the blood typing slides and return all materials. Conclusion: Based on your results, did the blood collected from the suspectâ€™s van come from the suspect? ____________________________________________________ Could this blood have come from the victim? ____________________________ What can you conclude from your results? (Remember to cite your data). __________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ___________________________________________________________________________________ ______________________________________________________________________________________________________________________________________________________________________
12/12/2019 0 Comments
McDonald's Takes the Blame for Obesity - Essay Example
The following is an examination of Critical Concepts: Experts blame the adverts targeting children to be responsible for causing obesity. The most relevant concepts in the case against first food joints are their marketing policies. Perhaps the aim is to cripple the allure junk food produces through adverts which are particularly appealing to children. However, Ronald McDonald in the same light as Joe Camel is a bit of a stretch. Attacking the marketing strategies of business entities to me amounts to clutching at a straw. There are rules that govern the world of production and marketing. In a situation where a product has production rights, the production company has the right to market it. In view of the above sentiments, McDonald should consider rebranding its image but not to exclude Ronald McDonald. Marketers, especially in France argue that positive ad inclusions such as, â€œeat fruits daily, exercise, and drink a lot of waterâ€ appeal more to customers than severe health warnings. For instance the caption, â€œcigarette smoking is harmful to your health, did not reduce the number of smokers in Europe or America. Therefore, adding health messages as proposed by the French is a constructive move. When McDonald includes the health messages in its ads it will go a step further to include healthy substitutes to its menu. Negative publicity led to drop in sales in McDonaldâ€™s. This caused McDonald to add healthy food to their menu such as porridge and salad. The move led to a 90% positive turnaround in sales. It should be noted that the increased sales result from consumption of â€œnon-healthyâ€ foods such as burgers and fries. Some European nations in their fight against obesity push for a ban on fast food advertisements that target children. However, it is imperative to note that advertisements not directed to children may still influence them. In a situation, where bans on advertising directly to children are in place such as in Norway, the food companies will still advertise for adults. Nevertheless, the bans are crucial because they eliminate at least one influence of obesity. Conforming to the ban is also a positive marketing strategy for McDonaldâ€™s. Consumers will see their efforts in implement change, and this will retain their loyalty to their products as mentioned above. Problems facing McDonaldâ€™s positive ad strategy. The state of obesity has not improved ever since the launch of positive ads by McDonaldâ€™s. This is not the companyâ€™s fault, but critics do not seem to think so. Governments and health regulatory institutions are up in arms against McDonaldâ€™s. For instance, Prince Charles of England out rightly attributes obesity to McDonaldâ€™s. In response to the above situation, McDonald responds just like most companies in the food production industry. Self regulation in regard to advertisement is a common strategy where the company reduces adverts directed at children. In the case of fast foods, the company specifically cuts down on use of celebrities and cartoon characters in advertisements. McDonald, however, is not fully committed to this strategy. In the U.K, its dominant market is children under the age of sixteen, and it does not intend to lose this market. McDonald instead favors positive health messages to run alongside their advertisements. That way McDonaldâ€™
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