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Inhibitory effect of black tea on the growth of established skin tumors in mice: effects on tumor size, apoptosis, mitosis and bromodeoxyuridine incorporation into DNA.
By Y P Lu, Y R Lou, J G Xie, P Yen, M T Huang and A H Conney Abstract: The authors were trying to find out the inhibitory effect of black tea on the growth of established skin tumors in mice: effects on tumor size, apoptosis, mitosis and bromodeoxyuridine incorporation into DNA. There are totally two experiments on studying this topic. Mice with established papillomas were treated with black tea or decaffeinated black tea as the sole source of drinking fluid for 11-15 weeks. They repeat this experiment for four times and then found out that in the experiment of black tea inhibited the growth of papillomas has an average of 35%, 37%, 41% and 48% respectively, while the decaffeinated black tea inhibited papilloma growth by 27, 14% and 193% respectively. In the other separate experiment, they use the ultraviolet B light to treat the mice for 22 weeks, then waited for another 13 weeks to treat those mice with black tea as the drinking fluid for 11 weeks. It turned out that the tumor growth was inhibited by 70%. And the results “indicate that oral administration of black tea to tumor-bearing mice inhibited proliferation and enhanced apoptosis in nonmalignant and malignant skin tumors.” In the journal report, the authors reported the data and phenomenon very briefly but also clearly. I think one of the biggest characteristics of their language using is they can perfectly combine the data and the words into a kind of scientific telling way, which is completely different from the way we use to tell a story or write an article. For instance, when they talk about the material they used in the experiment, they will include the unit as well as the type of the material. What’s critical is, the sentences in their journal report are more official and precise. They use very professional and technical terms to illustrate the journal report, which makes this journal report seem more standard than ours. They actually communicate the results based on the data they got from the experiments, just like us, and then define whether their assumption is right or wrong. The using of words is all very clear and concise, which is different from an article writing, but it is not very hard to understand. So from this journal report, I think I learned how to write more formal experiment report with more scientific and professional terms. I think I need to work on the terms of things we would use in the experiment; this is one of the biggest parts that make the report look so professional. 8 Essential Science Practices SP 1 – representations & Models Use representations or models to represent scientific phenomena or solve problems. SP 2 - Calculations Use Mathematics and Calculations appropriately. SP 3 - Questioning Engage in scientific questioning to guide inquiry based investigations. SP 4 – Collect Data Plan and implement data collection strategies in relation to specific scientific questions. SP 5 – Analyze Analyze and interpret evidence gathered from an investigation SP 6 - Justify Justify and explain data results and analysis through debate and argumentation SP 7 – Identify errors Be able to identify and construct explanations of data collected and identify errors made & possible improvements in investigations. SP 8 - Connect Connect concepts learned and discussed in class to society, technology and the environment. The using and Incorporation of the 8 SP During the first unit, we learned many things using the 8 SP. We learned how to use the charts in the Excel to make a clear Scatter graph with x and y lines, which is the first step, representation and models. Then we learned how to calculate the circumference of the earth and also the formula of Newton's Law Of Cooling/Heatin, which is the second step, calculation. Then we engaged questions that were "would adding milk to the coffee affect the speed of temperature going down" and "is the earth a perfect sphere", and this was the third step, questioning. After having the questions, we had the 4th step, we collected many data during the experiments and investigation. Then, we compared the data we collected and found out that adding milk does affect the speed of temperature going down and also earth is not a perfect sphere, which is the fifth step, analyze. The next step is justify, so we talked to others and to see if we get the same ideas, if our results are all the same, then we are fine, if they are not the same, we have to find out who did it wrong and where went wrong. Then we tried to find out any errors in my experiment, for instance, the thermometers sometimes would accidently touched the bottom of the beakers, so we tried to solve it by not touching the bottom, and this is the step 7, identify error.Then step 8 is connect, we connected the formula and concept we learned and thought about some other experiments that were related to this experiment that we could do. Refection of Unit 1 I used to think that the reason why the speed of temperature going down is slower after adding milk was because the fat in the milk, now I know it is because the cooler stuff's temperature will goes down slower.
I used to think the earth is a perfect sphere, now I know it is not. I used to think that it is almost a miracle to calculate the time of death, now I know there's a formula of cooling and heating that we could base on. I used to think that everything cools down for no reason, it is just a process of losing heat, and will keep losing heat, but now I know it goes down to the surrounding temperature. I used to think that when we were doing the coffee project, we should use the same amount of coffee (after adding milk), no I know we need to use the same amount of mild before adding the milk. Homework Inquiry Question: “Is the Earth a perfect sphere? Justify your answer.”
Answer: No. Because the distance of the equator and the distance of the else place is different. Measured value: 150.23km (between 31°, 121°19′39.86″ and 29°, 121°19′39.86″) Accepted value: 39900km (pass through the Arctic and Antarctic) 40075.7km(pass through the equator) Calculation 1: Percent error=|39902.4-39900|/39900=0.06% Calculation 2: the rate of travel=39900/80=498.75(km/day) the days will take=39900/100(km/day)=399(days) It is quicker to take the polar route. Because the circumference measured around equator is greater than the circumference measured around the polar. |