The Trials of Amanda Knox and Raffaele Sollecito: Part 29

[LondonJohn]

What? Most viruses do not penetrate the skin.

Did you even read what I wrote??

 

[Vixen]

Astonishingly wrong. It's absolutely possible to obtain a full, court-usable DNA profile from shed epithelial skin cells. Just one example:

https://www.ncbi.nlm.nih.gov/pubmed/10198696






Why did Sollecito have to have been "in Mez' Mez's Kercher's room for his DNA to have ended up mixed into that pile of dust and debris containing the bra clasp, Vixen?

Are you, for example, even aware that Sollecito said that he used his hands to push hard against the exterior (i.e. hallway-facing) side of Kercher's bedroom door for several attempts? Are you further even aware that this door was by definition manipulated by either investigators or cleaners (in line with the sloppy, incompetent police work in this case, there's no record....) when it was taken off its hinges and placed within Kercher's room? Are you further even aware that a cleaner (presumably - again no record) spent time in Kercher's room moving stuff around and sweeping the floor (and it's safe to assume that this cleaner was taking zero steps to minimise cross-contamination)?







1) The presence of the DNA of at least two other unidentified males is, pretty much by definition, evidence that the bra clasp was contaminated.

2) What on Earth does this have to do with the evidence against Guede. Firstly, you are (of course) wrong that Guede's DNA - the important DNA evidence, that is - was collected "at the same time". In fact, the most damning sample of Guede's DNA was collected by the pathologist (Lalli) from inside and around Kercher's genital area. That moron Stefanoni and her incompetent "squad" were not involved in any way.

Yes, the Guede DNA from Kercher's bag was collected by the incompetent crime scene squad, and I have no idea quite how credible/reliable this evidence really was, because it was never properly tested within or outside the courtroom (because at the end of the day it was of very little importance in terms of proving Guede's guilt).

And secondly (as has been explained numerous times to you), there are a number of pieces of non-DNA evidence against Guede which, added to the genital DNA evidence, are absolutely sufficient to prove his guilt BARD.

There is numerous OTHER evidence against Knox and Solly as well and the absolutely definitive and pure are the most scientifically objective, neutral and strongest of all. The PCR readings are done by machine and cannot be faked.

 

[Vixen]

Did you even read what I wrote??

Stop pushing the idea that 'talcum powder teaches kids how germs are transmitted'.

Anyone who teaches this is a TERRIBLE teacher and a preacher of ignorance and superstition.

 

[Rolfe]

For goodness please don't teach young adults this. Most chronic skin conditions, eczema, psioriasis, dermatitis are NOT contagious. This is just teaching people to be ignorant. You cannot catch AIDS from someone by hugging them or shaking their hand.

Colds and flu are generally spread by coughs and sneezes. Tuberculosis often by drinking unpasteurised milk from infected cows.

Sheeeesh!!!

You seem ignorant of the difference between contagious and infectious, which was the point I was actually making.

You claimed it was impossible to catch a disease simply by touching someone. I pointed out that it's so possible that there's actually a specific word for diseases that are transmitted this way, that is "contagious", diseases spread by contact. You're even wrong about HIV, because although you can't catch it by shaking somoene's hand, it is passed on by sexual contact.

You also note that there are skin diseases that are not contagious (or even infectious). Again, so what? There are some that are. Contagious diseases exist, otherwise we would not have a word for them.

Your last paragraph simply notes that infectious diseases exist which are not (classically) contagious. Again, so what? By the way, TB is very seldom contracted from milk from infected cows nowadays.

I'm a Fellow of the Institute of Biology. I have worked in the biological sciences for my entire career, including working with molecular biology (DNA) testing. I began my career as a university lecturer teaching senior veterinary students, although latterly I was teaching BSc Animal Science students. I really don't think I'm up for taking direction as to what I shouldn't include in my lectures from an anonymous internet poster who clearly doesn't have much of a clue about any of this.

 

[Rolfe]

Absolute rubbish! Yo will only catch cold or flu from someone if you touch their damp/wet air-borne splutterings and then touch your eyes and mouth.

The flu virus and the cold virus cannot penetrate your skin. It is spread by coughs and sneezes. SHEEESH. So ignorant.

That's a perfectly good explanation of the basics of disease transmission. It's very far from being absolute rubbish.

First, your claim was that it's impossible for someone to catch a disease (any disease, apparently) simply by touching someone. That's obvious nonsense, there is a whole category of infectious disease (contagious diseases) which require contact for transmission. Falling back on cold and flu viruses, a tiny subsection of infectious disease, is a distraction.

It's not even a correct distraction, because while cold and flu viruses aren't classified as being "contagious" in that they don't require contact for transmission, they can easily be caught by touching someone, getting the virus on your hand, and then transferring it to your respiratory tract. A contact transmission doesn't require skin penetration - something you seem to realise even as you deny it.

 

[Rolfe]

Only female DNA can be identified from mtDNA (mitochodria) as only females have the X chromosome from which the mtDNA is extracted. Likewise only males can have Y-haplotypes identified as it carries down from the male line. If you want to know the mtDA background ask your mother or sister to be tested and that will tell you, likewise females can find out about the male line via their father or brother.

I'm just going to leave that one there. For posterity.

 

[Rolfe]

Really? I could have sworn she was a vet. So now she's DNA-profiling sheep and cattle?

As I mentioned, I have spent my career in laboratory medicine. We had a very large molecular biology department in the institute I retired from earlier this year, indeed we were a reference lab for Britain for a number of DNA-based investigations. And yes, there is a lot of DNA work involved in sheep and cattle medicine these days.

 

[Rolfe]

No he didn't say shaking hands.

The vast majority of contagious diseases are air-borne, water borne or passed on through bodily fluids.

It is grossly stupid to give children talcum powder to demonstrate how diseases are passed around.

Contagious diseases are passed on by contact. Is that so hard to understand? Airborne and water-borne diseases are, by definition, not contagious. They are infectious.

Bodily fluids that require contact to transmit them would be classified as contagious disease. Even diseases that are not classically contagious, in that they do not require contact for transmission, can frequently be transmitted by contact.

Talcum powder is a very good way to demonstrate to children how microscopic objects can be passed around the environment by touching things. Nobody was suggesting that the talcum powder somehow had to pass through intact skin. Got some on your finger? Just licked your finger? Oops.

 

[Rolfe]

We seem to have started from here.

I can see you know little about pathology if you think you can catch disease from someone just by touching them. May I suggest you inform yourself?

As someone who spent an entire career working in pathology labs, I think I'm in a position to say that it's entirely possible to catch a disease simply by touching someone.

We now seem to have morphed into "but cold and flu viruses don't burrow through the skin!"

However, your cold or flu is transmitted by airborne droplets, with some perhaps landing on your fingers when you blow your nose or cover your mouth and then touching the ill person who then transfers it to his mouth, nose or eyes. (Or simply breathes in the airborne droplets.)

To believe it is passed on through skin - which actually forms a barrier to the outside world and protects you - is grossly ignorant.

What? Most viruses do not penetrate the skin.

Are we done yet?

 

[Vixen]

You seem ignorant of the difference between contagious and infectious, which was the point I was actually making.

You claimed it was impossible to catch a disease simply by touching someone. I pointed out that it's so possible that there's actually a specific word for diseases that are transmitted this way, that is "contagious", diseases spread by contact. You're even wrong about HIV, because although you can't catch it by shaking somoene's hand, it is passed on by sexual contact.

You also note that there are skin diseases that are not contagious (or even infectious). Again, so what? There are some that are. Contagious diseases exist, otherwise we would not have a word for them.

Your last paragraph simply notes that infectious diseases exist which are not (classically) contagious. Again, so what? By the way, TB is very seldom contracted from mild from infected cows nowadays.

I'm a Fellow of the Institute of Biology. I have worked in the biological sciences for my entire career, including working with molecular biology (DNA) testing. I began my career as a university lecturer teaching senior veterinary students, although latterly I was teaching BSc Animal Science students. I really don't think I'm up for taking direction as to what I shouldn't include in my lectures from an anonymous internet poster who clearly doesn't have much of a clue about any of this.

What?! 'Cont-' is synonymous with 'touching by hand' and therefore talcum powder is a good way to teach kids about how disease is passed on?

Rubbish! The 'cont' prefix refers to any type of contact, such as breathing in someone else's airborne germs or an exchange of bodily fluids (for example, having unprotected sex with someone infected with AIDS or using a dirty needle, ditto). This cannot be demonstrated with talcum powder.

Your denials are touching in your refusal to admit that the DNA evidence shows fairly and squarely that Knox and Sollecito were at the murder scene, he did place his DNA on the victim's bra clasp, she did wash off Mez' blood from her hands.

Your special pleading that you are somehow authorised or specially qualified to deny this is so doesn't fool anyone alert to logical fallacy and specious reasoning.

I bet you do not carry out forensic DNA profiling as you try to imply.

 

[Vixen]

I'm just going to leave that one there. For posterity.

Really? Are you trying to imply males can be tested for mtDNA?


Shocking the level of subterfuge you will adopt.

 

[Rolfe]

I just retired from a job where, every single day, I was responsible for issuing reports on DNA test results to clients. I was more senior than the technicians who actually carried out the testing.

You have painted yourself into a corner on the talcum powder thing. It's a good way to show children how something they can't see can be spread by touch. Nobody but you is imagining that anything has to burrow through the skin in order to infect by contagious transmission.

Contagious means what it says. Direct contact, including sexual contact and direct contact with infectious body fluids. That does not include airborne spread, specifically. Words mean things.

Just because some contagious diseases require more intimate contact than a superficial touch doesn't invalidate the talcum powder demonstration as a good way to show children how most bacteria and many viruses spread.

 

[Vixen]

As I mentioned, I have spent my career in laboratory medicine. We had a very large molecular biology department in the institute I retired from earlier this year, indeed we were a reference lab for Britain for a number of DNA-based investigations. And yes, there is a lot of DNA work involved in sheep and cattle medicine these days.

So that makes you qualified to dismiss the findings of highly expert Italian forensic scientists.

Contemptible.

Like the time you claimed your field of expertise meant that the three boys found dead and hog-bound in a swamp had not been sexually assaulted, all because you have an admiration for the writings of Damien Echols whom you consider a fine chap.

Fair enough in your opinion he's innocent but don't try to claim special expertise in coming to your opinion which is worth more than the forensic scientists who were on the spot and came to a different conclusion.

 

[Rolfe]

Really? Are you trying to imply males can be tested for mtDNA?

Shocking the level of subterfuge you will adopt.

I am pointing out that males have X chromosomes. You work it out.

 

[Rolfe]

So that makes you qualified to dismiss the findings of highly expert Italian forensic scientists.

Contemptible.

Like the time you claimed your field of expertise meant that the three boys found dead and hog-bound in a swamp had not been sexually assaulted, all because you have an admiration for the writings of Damien Echols whom you consider a fine chap.

Fair enough in your opinion he's innocent but don't try to claim special expertise in coming to your opinion which is worth more than the forensic scientists who were on the spot and came to a different conclusion.

 

[LondonJohn]

We weren't talking about 'absolutes' we were talking about relatives.

As an example, think about the GBP/USD daily money market charts. The dollar might move against the pound by one-thousandth of a cent, but because these economist want to understand volatility their graphs look super steep and look as though the dollar or pound has plunged or steeply risen, when if you look at the same graph over, say, a three-month period, why, it looks quite flat!

Likewise RFU peaks is a good analogy to fiscal volatility. You want to know just how reactive your sample is and high RFU peaks relatively are a joy for the scientist doing a PCR run.

1) Hmmmm, your attempted analogy looks a little..... irrelevant?

2) Again, please read what I actually wrote. My post was written a) to counteract your specious claim that high RFUs imply blood; b) to explain to you that RFUs are nothing more than a measure of the reliability of a DNA profile in relation to background noise, and thus in effect they are a measure of the "purity" of a DNA-bearing sample (irrespective of what tissue/fluid that sample comes from); and c) to explain to you that the actual height of RFUs on an output chart are simply a function of how and by how much the lab analyst has chosen to amplify the sample in the machine - therefore "high peaks" are meaningless in and of themselves; what matters is the height of those peaks relative to the height of background peaks*


* And while we're on that topic, this is one of the very many mistakes Stefanoni made in the lab: she cranked up the amplification (well beyond the manufacturer's recommended upper limit) to get the "high peaks" she desired, but of course this also raised the peaks of the background noise - to a level which effectively invalidated the reliability of the subject peaks. What a surprise........

 

[Vixen]

I just retired from a job where, every single day, I was responsible for issuing reports on DNA test results to clients. I was more senior than the technicians who actually carried out the testing.

You have painted yourself into a corner on the talcum powder thing. It's a good way to show children how something they can't see can be spread by touch. Nobody but you is imagining that anything has to burrow through the skin in order to infect by contagious transmission.

Contagious means what it says. Direct contact, including sexual contact and direct contact with infectious body fluids. That does not include airborne spread, specifically. Words mean things.

Just because some contagious diseases require more intimate contact than a superficual touch doesn't invalidate the talcum powder demonstration as a good way to show children how most bacteria and many viruses spread.

Sorry, that teaches ignorance. There was a case of an airline stewardess who ordered a young boy off a passenger place because he had 'harlequin' syndrome dermatitis. She ignorantly believed it to be contagious and that anyone touching him would be infected.

Give children the facts, not ignorant nonsense.

 

[Rolfe]

Sorry, that teaches ignorance. There was a case of an airline stewardess who ordered a young boy off a passenger place because he had 'harlequin' syndrome dermatitis. She ignorantly believed it to be contagious and that anyone touching him would be infected.

Give children the facts, not ignorant nonsense.

Many people believe that all visible skin lesions are contagious. That is incorrect, but it has absolutely nothing to do with the utility of using talcum powder to demonstrate to children how microscopic particles can be spread around the environment by touch.

Get a grip.

 

[Vixen]

I am pointing out that males have X chromosomes. You work it out.

Humans have two pairs of chomosomes either XY or YY. The former is female and you can extract mtDNA for the haplotype, the latter are male and you can perform Y-haplotype profiling on a male but not on a female.

Of course everybody has mitchondrial material in their biological cells but we are discussing here DNA profiling.

 

[Rolfe]

Have we got any closer to understanding that males have X chromosomes yet?


Sorry, I cross-posted that.

You've just pointed out that you can only do a test which requires a Y chromosome on males, which is perfectly correct. However, as you also (belatedly) admitted, males also have an X chromosome. So can you work that a bit further?