PT10.S1.Q24- The body of anyone infected

westcoastbestcoast

For this particular question, I had difficulty understanding what the last sentence was actually saying. I interpreted the sentence to mean that the test could be used during the first year of infection to detect how long one had the virus for a given month. Is this the correct interpretation? Also does it imply that if one has the virus for more than a month for the first year of infection that the test cannot be used? That implication seemed counter intuitive to me, and so I'm having trouble parsing out the language.

BinghamtonDave

This is an interesting question and something that the LSAT does quite often on contemporary tests. It requires a close reading and understanding of the stimulus and really nothing more in my estimation. No fancy conditional chains or negation tests here. Going into the answer choices, I didn't really know what to expect. In the end it turns out to be a tricky detail that the question is calling on. I have drawn out a diagram for this question that really helped me: the person in our diagram got the virus on 10/21/16. After 10/28/16 (a week from now) that person produced antibodies. The stimulus tells us that those antibodies will increase for the next year. What we know for an MSS question at this juncture is that there will not be less antibodies in say May 2017 or August 2017 then there was immediately after 10/28/16. The second sentences tells us that there is a test that essentially counts the antibodies. The third and final sentence tells us that any time within the first year of infection the test can calculate to the month "how long someone had the infection" by referent to the number of antibodies. The term "if positive" here is important but not crucial in my estimation. "If positive" seems to indicate that if the tests counts antibodies then we can get a sketch of how long that person has had the virus. But we should remember that there is a gap of a week (highlighted in yellow) in which the person didn't actually produce antibodies. Meaning that if that individual is tested by the test mentioned that relies on antibody count during that first week the test will not accurately show the result: essentially the person will have the virus yet it won't show.

This is what (E) says.




In conclusion I think we should heavily interrogate the remaining answer choices:
(A) is an assertion about the lifespan of an antibody in which there is no support.
(B)This is a statement about the world of existing tests for this virus. Of which we know nothing beyond the antibody count test.
(C) this is again a statement about the life of an antibody and its purpose. Nothing we really have support for
(D)No support for an infinite increase in antibodies from the stimulus.

I hope this helps parse out some of the confusion.

westcoastbestcoast

@David3389 Thank you for the detail diagram haha, You helped me catch a detail that I initially missed, the one about how the antibodies will increase next year. With your description of the third sentence, do you mean that we can calculate how long an individual had the virus from the day he was tested up until a month prior to that?

BinghamtonDave

No, I think what the stimulus is saying is that if positive then we can "estimate within a month" when that person actually got the virus. The concept is confusing and the stimulus does little to elevate that confusion but what I took this to mean is basically that after the first week the body produces antibodies and they increase throughout the year. So our person starts with 5 antibodies and each month gets 5 more. Well if they have 20 antibodies on the test then the stimulus is saying that we can estimate that they got the virus about 4 months ago (give or take a month).

I've been told that a similar principle is roughly used to date the age of trees by tree rings-give or take a year or so. I've never really looked into it but I've been told that if a tree has tons of rings and you know it creates a ring every 200 days you can do some calculations and work backwards to deduce the year the tree began growing. I took the stimulus to mean something roughly along these lines.

westcoastbestcoast

Hmm.. Didn't the stimulus say that the antibodies increase in the next year, not necessarily on a monthly basis? I'm still having trouble seeing how the phrase " to estimate to within a month how long an individual had virus" translates to "to estimate how long an individual had the virus, give or take a month". Doesn't " within a month" indicate a month long time period?

inactive

Bumping since this is on page 2 and you still have questions.

Lsatbreakingnews

@westcoastbestcoast said:
Hmm.. Didn't the stimulus say that the antibodies increase in the next year, not necessarily on a monthly basis?

The stimulus states that antibodies will increase in number for the next year. Meaning there will be growth as the year progresses.

@westcoastbestcoast said:
I'm still having trouble seeing how the phrase " to estimate to within a month how long an individual had virus" translates to "to estimate how long an individual had the virus, give or take a month".

The stimulus states that there is a new test which indicates how many antibodies are in a persons body. The purpose of this test is to estimate how long a person has had the infection for. How accurate is the test in determining the time a person has had the virus for? Well lets look at the last sentence: ....this test can be used during the first year of infection to estimate within a month how long that person has had the virus. So that means that the accuracy of determining how long a person has had the virus for is not within an hour, or day of having been infected, but the accuracy of estimating how long the person has had the virus is within one month.

westcoastbestcoast

Thanks for the clarification @Euthyphro. I now understand that to estimate to within a month essentially means that the estimate has a 1 month margin of accuracy. I initially interpreted "for the next year" to mean the duration of year coming after the current, because of the word next. Could you explain why "for the next year" idiomatically means that the increase in antibodies will happen starting from the current year up until the next?

Lsatbreakingnews

@westcoastbestcoast said:
Could you explain why "for the next year" idiomatically means that the increase in antibodies will happen starting from the current year up until the next?

I think that next "year" is what has you confused. Take another time period for example..you're studying and you tell you're roommate to quiet down because you'll be studying for the next hour or so. Or you tell your mom for the next month I will be on a diet. So the year is what had you tripping up I think.

westcoastbestcoast

@Euthyphro thanks for the examples! For some reason, things clicked when you provided common examples one would say in conversation.