Continuation Part 5: Discussion of the Amanda Knox/Raffaele Sollecito case

[Briars]

Excuse me? You see this is where both you and Massei go riding the train off the rails. There in fact is no evidence that the DNA in this blob is any different than any epithelial cell (dried or fresh) That is of course, impossible to determine. Please provide scientific peer reviewed evidence, not some know it all lawyer or judge who flunked out of science class. (Also, you still keep saying this blob is Meredith's blood despite the negative TMB test or any confirmatory antibody test)

How do you or anyone have the right to say that it is blood given that fact? Do you think that if you call it blood over and over again without the test that somehow the world should believe it to be blood?

You see, that is the difference between you and I Briars. I think the police and prosecution have to prove their contentions, not merely make them.

All we know about that blob, is that it fluoresced under Luminol and that when swabbed a DNA profile from Amanda was identified. No one, not Massei, not me, not you NOT ANYONE can tell us the nature of that DNA. That is the fact. The rest, is in fact, conjecture.

You are clearly confused ,dust DNA would have been everwhere in the cottage. Dust is MAINLY made up of shed dried skin cells. Can you figure out that the dust in the cottage including Meredith's room would contain the shed cells from all the girls including Amanda The sample in the blob and the clasp were from live cells and different.

 

[acbytesla]

This is news to you Bill that sloughed off DNA found in dry skin cells is incomplete and different from a live sample ?? wow

It's news to a lot of people Briars. As the vast majority of DNA found is in fact dead epithelial cells. Most of the outer layer of skin on your body is in fact dead epithelial cells. Humans exfoliate those skin cells constantly through touch.

Maybe it is your misunderstanding of the science that has led you to be so mistaken about this case? Maybe??

 

[Chris_Halkides]

DNA is not a means of typing tissue

This is news to you Bill that sloughed off DNA found in dry skin cells is incomplete and different from a live sample ?? wow

There is a grain of truth to this statement, but there is also a serious misunderstanding. The grain of truth is that when a cell becomes keratinized, it does eventually lose its DNA. But if that happened to completion, there would simply be no DNA profile present, yet as acbytesla noted, DNA is transferred when we touch an object.* If it happened partially, one might conceivably detect this as a gradual decrease in peak height as one goes from left (small fragments) to right (large fragments). "Incomplete" is an incorrect description; "degraded" is better. However, I have never seen anyone try to use this as evidence of DNA coming from skin cells in a scientific paper, and I can offer at least one reason why: Any random degradation of DNA would produce exactly the same effect, and many things can degrade DNA. A few that come to mind are sunlight, bleach, possibly anything that can produce a hydroxyl radical, random nuclease enzymes in the environment, and who knows what else. DNA profiling is absolutely not a means of telling one tissue from another, because (with the exception of sperm and egg) the DNA in all cells is essentially identical. To tell one tissue from another requires other sorts of tests, and Conti and Vecchiotti rightly took Ms. Stefanoni to task over her overinterpretation of the data with respect to this point.

*EDT Some of the DNA transferred by touch is cell-free DNA. There was a thread started by kestrel about three years ago in the Science subforum here about whether or not skin cells have DNA.

 

[Chris_Halkides]

a near-axiom of DNA profiling

The reality is that sloughed of dry skin abundant in dust is not the type of DNA found in the blob which is a concern. To explain how it arrived mixed in the sample with Meredith's blood, Massei gave an example of vigourous hand washing which extracted a very different and far less common type of DNA.

Massei does not claim it is a different kind of DNA. Nor does he explain how it would be different from the skin cells Amanda would have also shed a day or a week earlier (and it wouldn't be). DNA cannot be interrogated as to the time or manner in which it arrived on an item. This is very close to being an axiom of forensics. The mixed DNA in the bathroom most probably arose in one of two ways. Either Meredith's blood landed directly on biological matter from Amanda, or it landed close by and was mixed by poor collection techniques. We have discussed the deficiencies of the collection techniques many times before.

 

[acbytesla]

You are clearly confused ,dust DNA would have been everwhere in the cottage. Dust is MAINLY made up of shed dried skin cells. Can you figure out that the dust in the cottage including Meredith's room would contain the shed cells from all the girls including Amanda The sample in the blob and the clasp were from live cells and different.

Do your really believe Briars, that the 200 trillionths of a gram of skin cells on the bra clasp were still alive after 47 days? And those cells can be differentiated from sloughed off skin cells from 60 days before? Seriously?

C'mon Briars, think about it. Don't just mouth the line. You're smarter than this. I know you are. Take a deep breath and think.

 

[Bill Williams]

Briars has called it "different" DNA, and then calls it "incomplete" DNA.

Let's at least find out what Briars means.... different or incomplete?

It would also be helpful if Briars could provide the citation from Massei, where the convicting judge uses this as some basis for convicting.....

Even though the ISC has overturned the Hellmann acquittals, it remains to be seen what the new fact-finding court makes of the Conti-Vecchioti report.

Briars - I have reached my own limit of comment about DNA here... you have made a claim about a "different" kind of DNA. Others more knowledgeable have pooh-poohed you.

My request is that you make this something other than an assertion; that you point to something (preferably not from Stefanoni or anyone from TJMK!) who backs you up on this - otherwise, this is simply another one of those guilter factoids they love to assert to confuse folks.

 

[Briars]

you are deliberatly avoiding the DNA blob in Filomena's room which is far more difficult to wave away. The DNA from a live cell is different from common dust and can be the result of spit or vigourous washing. It was deposited at the same time on the same spot mixed with Meredith's live profile.

 

[acbytesla]

Bill, I'm going to give Briars the benefit of the doubt. That he just didn't understand the DNA as well as he thought he did. There is no shame in this. The DNA evidence IS difficult to understand. I think we can all appreciate that. He's just wrong. Just as Edison was wrong about Alternating Current and Einstein was about Quantum Mechanics.

Even smart people are wrong occasionally. It could happen to me... I doubt it...but it could.

 

[acbytesla]

you are deliberatly avoiding the DNA blob in Filomena's room which is far more difficult to wave away. The DNA from a live cell is different from common dust and can be the result of spit or vigourous washing. It was deposited at the same time on the same spot mixed with Meredith's live profile.

It is doubtful, that the DNA in the blob in Filomena's room was alive either. How long do you think cells live after they are no longer supported by your body? Minutes?? Days?? Hours?? how long??

You are coming to a conclusion without a speck of evidence to support any of it. Can't you see that? Stop trying "not to be wrong". You don't have a clue about this. Neither do I, but I know that I don't have a clue. This is why I am not talking out my ass. You need to stop talking out of yours.

 

[Chris_Halkides]

being wrong can be a good thing

Bill, I'm going to give Briars the benefit of the doubt. That he just didn't understand the DNA as well as he thought he did. There is no shame in this. The DNA evidence IS difficult to understand. I think we can all appreciate that. He's just wrong. Just as Edison was wrong about Alternating Current and Einstein was about Quantum Mechanics.

Even smart people are wrong occasionally. It could happen to me... I doubt it...but it could.

Good point. Pauling proposed a structural model of DNA that was wrong. Watson and Crick's first model of DNA was wrong, although less so than Pauling's. Good scientists don't fall in love with their ideas. The opposite happens; they learn to be glad that they were wrong, because it means that they learned something new. And sometimes when you are wrong, you can get some mileage out of it. Watson and Crick incorporated their mistake into their theory of how some mutations occur.

 

[Briars]

Bill, I'm going to give Briars the benefit of the doubt. That he just didn't understand the DNA as well as he thought he did. There is no shame in this. The DNA evidence IS difficult to understand. I think we can all appreciate that. He's just wrong. Just as Edison was wrong about Alternating Current and Einstein was about Quantum Mechanics.

Even smart people are wrong occasionally. It could happen to me... I doubt it...but it could.

Chris isn't helping you out with his grain of truth bit. Dust is 80+% dried skin cells , Dust was everwhere in the cottage. Amanda's dust DNA would be in Meredith's room no doubt. That is not the kind in the blob or clasp which was a live sample. Clear the cobwebs and dust from your brains please,

 

[acbytesla]

Chris isn't helping you out with his grain of truth bit. Dust is 80+% dried skin cells , Dust was everwhere in the cottage. Amanda's dust DNA would be in Meredith's room no doubt. That is not the kind in the blob or clasp which was a live sample. Clear the cobwebs and dust from your brains please,

Briars, You need to stop. You clearly don't understand this.

There is NO WAY to differentiate the type of cell through DNA testing PERIOD. You can't tell if that DNA came from a skin cell or a liver cell. You can't tell if it came from the epidermis or the dermis, you can't tell if it came from a red blood cell or a stem cell. You can't tell if it came from your elbow or your foot. At least not through a DNA test. Also, there is also no way to know,if that DNA was deposited the day before or the week before. PERIOD. End of story Briars.

I don't know, and I sure as hell know that you don't know.

 

[acbytesla]

Good point. Pauling proposed a structural model of DNA that was wrong. Watson and Crick's first model of DNA was wrong, although less so than Pauling's. Good scientists don't fall in love with their ideas. The opposite happens; they learn to be glad that they were wrong, because it means that they learned something new. And sometimes when you are wrong, you can get some mileage out of it. Watson and Crick incorporated their mistake into their theory of how some mutations occur.

You just brought up something that make me angry Chris. And that is the fact that Crick and Watson are remembered and they shared the Nobel prize and of course they couldn't have done it without the work of Rosalind Franklin.

She certainly was deserving of the prize as was Lise Meitner both of whom were slighted because they were women. But on the other hand neither Tesla or Edison won the prize either.

 

[Briars]

Briars, You need to stop. You clearly don't understand this.

There is NO WAY to differentiate the type of cell through DNA testing PERIOD. You can't tell if that DNA came from a skin cell or a liver cell. You can't tell if it came from the epidermis or the dermis, you can't tell if it came from a red blood cell or a stem cell. You can't tell if it came from your elbow or your foot. At least not through a DNA test. Also, there is also no way to know,if that DNA was deposited the day before or the week before. PERIOD. End of story Briars.

I don't know, and I sure as hell know that you don't know.

Oh my are you still trying to say that the incomplete DNA found in dry cells found in dust is the same as a sample from saliva or cells shed from vigourous washing? Tell me you are not,there is no need to alter the argument with liver or skin cells just answer the question I asked simply please.

 

[Chris_Halkides]

Let's look at the egrams

Chris isn't helping you out with his grain of truth bit. Dust is 80+% dried skin cells , Dust was everwhere in the cottage. Amanda's dust DNA would be in Meredith's room no doubt. That is not the kind in the blob or clasp which was a live sample. Clear the cobwebs and dust from your brains please,

Briars,

Here is a link to the egrams. Reps. 176 and 177 are mixed samples that come from Filomena's room. Maybe you can explain how this DNA is different, based on the appearance of the egrams.

People deposit DNA around their house by more means that just creating household dust. Talking and sneezing will deposit DNA, for example. Walking on the floor in bare feet should also deposit DNA. Again, DNA does not contain a time stamp. Amanda washed and brushed her teeth in the sink many times. How could one possibly differentiate the DNA she deposited at those times from one time in which she hypothetically washed blood off her hands?

 

[acbytesla]

Oh my are you still trying to say that the incomplete DNA found in dry cells found in dust is the same as a sample from saliva or cells shed from vigourous washing? Tell me you are not,there is no need to alter the argument with liver or skin cells just answer the question I asked simply please.

What I am saying is that you can't differentiate by DNA profile alone whether that DNA came from saliva or a skin cell deposited a day before or a week before. As Chris pointed out, that over time DNA degrades but the rate of that degradation is difficult to calculate. And that this point of yours that somehow this profile found in the DNA blob is indicative of being the result of "vigorous washing" is poppycock.

 

[Prometheus]

....
One very bad thing about Seattle is its public school system. Fully one-third of kids who start high school in Seattle drop out before graduation; ...

That actually places it just above the middle of the pack for the U.S., sadly...
link

 

[Chris_Halkides]

definitions and comments

A partial or incomplete profile is one in which peaks show up in some loci (locations) but not others. Incomplete profiles mean that the DNA profiling is less discriminating. When a sample is very degraded, the result may be a partial profile. That is because the largest pieces of DNA are more likely to have been degraded

A weak profile could be defined as one in which the amount of DNA is low, leading to smaller peaks. It could also be defined as simply one in which the peaks are small. The two definitions are almost equivalent.

One cannot assume, for example, that secondary transfer always results in a partial profile. One cannot assume that the last person to touch an item will deposit the most DNA. But above all one cannot infer tissue type on the basis of peak heights.

 

[Briars]

What I am saying is that you can't differentiate by DNA profile alone whether that DNA came from saliva or a skin cell deposited a day before or a week before. As Chris pointed out, that over time DNA degrades but the rate of that degradation is difficult to calculate. And that this point of yours that somehow this profile found in the DNA blob is indicative of being the result of "vigorous washing" is poppycock.

I'm glad any confusion over dried shed skin cells is past us. What you are left with though is a blob of mixed profiles which came together at the same instant, or Meredith's profile dropped on the exact little spot where a drop of Amanda's lay waiting. Keeping it to Filomena's room this would be a remarkable occurance. We are not talking about a large area just little spots of mixed profiles in a room that didn't belong to either girl. What would the odds be?

 

[acbytesla]

I'm glad any confusion over dried shed skin cells is past us. What you are left with though is a blob of mixed profiles which came together at the same instant, or Meredith's profile dropped on the exact little spot where a drop of Amanda's lay waiting. Keeping it to Filomena's room this would be a remarkable occurance. We are not talking about a large area just little spots of mixed profiles in a room that didn't belong to either girl. What would the odds be?

Well clearly it is not behind us as you keep postulating that Amanda's DNA profile came to a specific location at the exact same time as Meredith's . Given the fact that DNA CANNOT BE TIME STAMPED, there simply is no way to come to that conclusion scientifically.

In other words, you are just wildly guessing. Just because you run something up the flag pole doesn't make it the Star Spangled Banner or the Union Jack and the rest of us should salute it.