Cycling and bicycle racing discussion forums.   View New Forum Topics
Today's Forum Topics

Set as homepage


Go Back   Cycling Forums > Other Stuff > Doping
User Name
Password
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read


Welcome to CyclingForums.com

You are currently viewing our website as a guest which gives you limited access to view most discussions. You will have to register before you can post to this thread.

By joining our free online community you will have access to post new topics, communicate privately with other cyclingforums.com members (PM), respond to polls, upload photos and access other special features like product reviews and classifieds.


**** Breaking News: Hamilton Tested Positive? ***

Reply
 
Thread Tools Search this Thread Display Modes
Old 19-11.-2004, 05:00 AM   #526
Virenque
Registered User
 
Virenque's Avatar
 
Join Date: Sep 2004
Location: Ljubljana, Slovenia
Posts: 1,213
Send a message via MSN to Virenque
Default Re: **** Breaking News: Hamilton Tested Positive? ***

No, it`s about justice!
Virenque is offline  
Reply With Quote
Old 19-11.-2004, 05:15 AM   #527
fbircher
Registered User
 
Join Date: Sep 2004
Posts: 217
Default Re: **** Breaking News: Hamilton Tested Positive? ***

meb:


Thanks for the information. BTW, 2^13=8192, not 4096. I'm assuming from your math that there are only 2 possible values for each antigen category, otherwise 13 antigens would result in more than 8192 possible combinations. Do we know for sure if this is the case?

I'm not sure how we go from 8192 (or 4096) possible combinations to odds of 1.7/1000 for two randomly selected subjects to show a match across all 13 antigens. Do you know how this can be case? Your final comments about closer matching between siblings and blood relatives means that a cheater would have better odds of escaping detection by tranfusing blood from a close relative - is that the bottom line for the data on relatives? Unless I'm misreading your numbers, the higher likliehood of a match between relatives doesn't bear any significance for the likelihood of a false positive test result for a randomly chosen cyclist, only the likelihood of a false negative, depending on the similarities between donor and recipient.


Quote:
Originally Posted by meb
The 1/10,000 would not be mathematically possible with 13 antigens being tested for: 2^13=4096. So even if you had an exact 50-50 phenotype split in your tests, 1/4096 would be the most extreme odds in a random sample.

The developers have asserted 1.7/1000 matches in the caucasion population, 2/1000 in the asian population, and 3/1,0000,000 in the black population (obviously on the black population matching the developer made a jumbo error/mistatement-do the math). Keep in mind that is RANDOM samples of the population. A non-twin sibling/parent/child would have a 1/22 chance at an exact match if the parents were randomly chosen from the general population. 1/16 persons would differ by only 1 antigen, 1/60 by only 2 antigens. Within closely related ethnic groups within a race, the correlation between donor and recipeint would be significantly stronger.
fbircher is offline  
Reply With Quote
Old 19-11.-2004, 06:02 AM   #528
Beastt
Registered User
 
Beastt's Avatar
 
Join Date: Sep 2003
Location: Arizona (USA)
Posts: 1,141
Send a message via AIM to Beastt Send a message via Yahoo to Beastt
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Quote:
Originally Posted by Virenque
No, it`s about justice!


Okay.

I guess I misunderstood your post. It seemed like there was a lot more concern about which country would take the honor of the gold rather than which cyclists would receive what they were cheated out of if indeed Hamilton is unable to provide a compelling defense.

By the way, can you define "justice"?
Beastt is offline  
Reply With Quote
Old 19-11.-2004, 06:04 AM   #529
fbircher
Registered User
 
Join Date: Sep 2004
Posts: 217
Default Re: **** Breaking News: Hamilton Tested Positive? ***

meb:


One more point on your numbers. The lower the number of possible antigen combinations, the higher the likelihood of two randomly chosen subjects having a match, the higer the likelihood of a false NEGATIVE. As I understand it, this test flags a cheater by finding different combinations of antingens in blood cells of one person. The fact that somebody else happens to have the same antigen combination as a given test subject still couldn't account for one test subject having two different antigen combinations. 1.7/1000 expresses the odds of a cheater getting lucky and having a blood donor that happens to match his own antigen combination, which would yield a false negative.

Quote:
Originally Posted by fbircher
meb:


Thanks for the information. BTW, 2^13=8192, not 4096. I'm assuming from your math that there are only 2 possible values for each antigen category, otherwise 13 antigens would result in more than 8192 possible combinations. Do we know for sure if this is the case?

I'm not sure how we go from 8192 (or 4096) possible combinations to odds of 1.7/1000 for two randomly selected subjects to show a match across all 13 antigens. Do you know how this can be case? Your final comments about closer matching between siblings and blood relatives means that a cheater would have better odds of escaping detection by tranfusing blood from a close relative - is that the bottom line for the data on relatives? Unless I'm misreading your numbers, the higher likliehood of a match between relatives doesn't bear any significance for the likelihood of a false positive test result for a randomly chosen cyclist, only the likelihood of a false negative, depending on the similarities between donor and recipient.
fbircher is offline  
Reply With Quote
Old 19-11.-2004, 07:15 AM   #530
Virenque
Registered User
 
Virenque's Avatar
 
Join Date: Sep 2004
Location: Ljubljana, Slovenia
Posts: 1,213
Send a message via MSN to Virenque
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Quote:
Originally Posted by Beastt
Okay.

I guess I misunderstood your post. It seemed like there was a lot more concern about which country would take the honor of the gold rather than which cyclists would receive what they were cheated out of if indeed Hamilton is unable to provide a compelling defense.

By the way, can you define "justice"?
I wil define what I mean with justice in that case. I want that medal goes to the rider who deserves it and Tyler definitively doesn`t because he tested positive! If Eki deserves his medal, I don`t know! I still think nearly all are doping, but to sorrow, Tyler is the only one we know that was doping! Hm..maybe justice really wasn`t the right word hehe..
Virenque is offline  
Reply With Quote
Old 19-11.-2004, 07:26 AM   #531
meb
Registered User
 
meb's Avatar
 
Join Date: Aug 2003
Location: arlington, VA
Posts: 1,212
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Quote:
Originally Posted by fbircher
meb:


One more point on your numbers. The lower the number of possible antigen combinations, the higher the likelihood of two randomly chosen subjects having a match, the higer the likelihood of a false NEGATIVE. As I understand it, this test flags a cheater by finding different combinations of antingens in blood cells of one person. The fact that somebody else happens to have the same antigen combination as a given test subject still couldn't account for one test subject having two different antigen combinations. 1.7/1000 expresses the odds of a cheater getting lucky and having a blood donor that happens to match his own antigen combination, which would yield a false negative.


The 1.7/1000 the developer cited reflects the phenotypes not being split 50-50 on each of the ten antigens in the original test. You would get the longest odds at matching donor-recipient for a given number of phenotypes if the incidence was split 50-50, anything else reduces the likelihood of a difference. (i.e. a 50-50 phenotype split results in a 50-50 random chance of a match on an antigen, a 90-10 phenotype split means .9x.9+.1x.1=.82 so there is an 82% random chance of a match)

I assume the 13 you came up with represents 3 additional antigens having been added from the group of 10 antigens that had sufficient diversity in the populace to serve as a screening test. . The developer did state they might be developed for additional detection.

Your correct on the 2^13, it is 8096.
There’s only two alleles on each of those genes (or at least the 10 original ones, not sure about the additional 3 you spoke of).
Some of the reads will show reduced antigen counts on heterozygous individuals relative the homozygous positive state, so there will be third level detected on some antigens.

Close relative donors would already have half the same chromosomes as the recipient (in a sibling, unlike a lineal, it could randomly be slightly higher or less). That figure I gave was for randomly chosen close relatives-since persons often mate from smaller population groups than the general populace. Persons of a subpopulation are going to have similar antigens. A child of two Swedes is more likely to have similar antigens amongst close relatives than a child of English and Greek parents.

If any of the genes are sited on common chromosomes, the prospects for matching would increase.

With a close relative, the odds would be above 1/3 for a mismatch of precisely 1 antigen (vs. 1/16 for the general populace). If you knew what the differing antigen tested was, you might be able to develop a mask specific to the test.
meb is offline  
Reply With Quote
Old 19-11.-2004, 07:26 AM   #532
Beastt
Registered User
 
Beastt's Avatar
 
Join Date: Sep 2003
Location: Arizona (USA)
Posts: 1,141
Send a message via AIM to Beastt Send a message via Yahoo to Beastt
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Quote:
Originally Posted by Virenque
I wil define what I mean with justice in that case. I want that medal goes to the rider who deserves it and Tyler definitively doesn`t because he tested positive! If Eki deserves his medal, I don`t know! I still think nearly all are doping, but to sorrow, Tyler is the only one we know that was doping! Hm..maybe justice really wasn`t the right word hehe..


I'd say in this instance your definition of justice is appropriate. I'm often amazed at how the word is thrown around in other cases where the word can be less clearly defined. If indeed Hamilton utilized unethical blood manipulation to win, then awarding the medals to the riders in line sequentially behind him would at least be an attempt to set things straight. Often times, once a wrongful act has been perpetrated, there is no way to place the chain of events into reverse to attempt to rectify the situation yet the word "justice" is still waved like a flag over any proceedings which exist only as a punishment to the guilty.

I do find it interesting that a few here are so unwilling to wait until both sides have had the chance to present their evidence. The testing authorities have submitted positive tests as their evidence and it seems very compelling. But we've not heard from the other side yet. Half a story rarely carries as much truth as the whole story so why not wait until we have the whole story? If Hamilton can present a credible, reasonable defense which indicates that the tests, his genetics or who knows what, was responsible for the positive test results, then perhaps he can avoid a "miscarraige of justice". Punishing the innocent falls under no definition of "justice" that I've ever seen. I think it highly unlikely that he will be able to succesfully challenge the test results and as such will be determined to be guilty of blood doping. I still prefer to wait and see. It's not like he's going to have a better chance of slipping through the cracks if we wait until he's presented his defense. He'll either have a credible defense or he won't. Until then, the responsible "jury" is still out.
Beastt is offline  
Reply With Quote
Old 19-11.-2004, 07:53 AM   #533
fbircher
Registered User
 
Join Date: Sep 2004
Posts: 217
Default Re: **** Breaking News: Hamilton Tested Positive? ***

meb:


Thanks for the feedback. Now I understand why the overall likelihood of an antigen match differs from the simple ratio of possible combinations. You sound as if you have some expertise in the area of blood analysis/genetics. Based on your understanding of the approach this test uses to flag foreign blood cells, can you envision a way for one test subject to have two different antigen combinations in a statistically significant number of blood cells, other than transfusion? Setting aside the possibility of chimeras and accidental contamination in the lab, can you envision any other scenario that could account for this? It seems to me that the crux of Hamilton's defense will hinge on his ability to explain how he has different antigen combinations present in his blood cells, without having recieved a blood transfusion. Or perhaps he will argue that the test falsely identified differening antigen combinations, when in fact they we're all the same.


Quote:
Originally Posted by meb
The 1.7/1000 the developer cited reflects the phenotypes not being split 50-50 on each of the ten antigens in the original test. You would get the longest odds at matching donor-recipient for a given number of phenotypes if the incidence was split 50-50, anything else reduces the likelihood of a difference. (i.e. a 50-50 phenotype split results in a 50-50 random chance of a match on an antigen, a 90-10 phenotype split means .9x.9+.1x.1=.82 so there is an 82% random chance of a match)

I assume the 13 you came up with represents 3 additional antigens having been added from the group of 10 antigens that had sufficient diversity in the populace to serve as a screening test. . The developer did state they might be developed for additional detection.

Your correct on the 2^13, it is 8096.
There’s only two alleles on each of those genes (or at least the 10 original ones, not sure about the additional 3 you spoke of).
Some of the reads will show reduced antigen counts on heterozygous individuals relative the homozygous positive state, so there will be third level detected on some antigens.

Close relative donors would already have half the same chromosomes as the recipient (in a sibling, unlike a lineal, it could randomly be slightly higher or less). That figure I gave was for randomly chosen close relatives-since persons often mate from smaller population groups than the general populace. Persons of a subpopulation are going to have similar antigens. A child of two Swedes is more likely to have similar antigens amongst close relatives than a child of English and Greek parents.

If any of the genes are sited on common chromosomes, the prospects for matching would increase.

With a close relative, the odds would be above 1/3 for a mismatch of precisely 1 antigen (vs. 1/16 for the general populace). If you knew what the differing antigen tested was, you might be able to develop a mask specific to the test.
fbircher is offline  
Reply With Quote
Old 22-11.-2004, 01:29 PM   #534
gntlmn
Registered User
 
Join Date: Jul 2003
Location: Anchorage, Alaska, USA
Posts: 1,672
Default Re: **** Breaking News: Hamilton Tested Positive? ***

With Santiago Perez testing positive after the Vuelta (not during), it kind of makes you wonder whether Phonak has some kind of systematic doping program going on. Although I was a little bit surprised about Hamilton's positive, it lent more credence to the previous rumors--the one about the doctor refusing to help Hamilton acquire doping which was requested, he claims, by Tyler on behalf of Motorola, the other about Tyler's test results appearing abnormal during the month's preceding the Olympics and the Vuelta in 2004. Perhaps he has been doping all along. What surprised me was Santi Perez. I was starting to feel like he might be another hero of cycling after his stunning performance in the Vuelta. It's sad to see him in the same boat as Tyler now. And I wonder if they didn't collude on this doping activity or if they had help from the team or the team doctors.
gntlmn is offline  
Reply With Quote
Old 22-11.-2004, 02:05 PM   #535
Vector7
Registered User
 
Join Date: Sep 2003
Posts: 157
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Does anyone have a current status report on Floyd Landis? Where is he going?

Best Wishes,
Vector7
Vector7 is offline  
Reply With Quote
Old 23-11.-2004, 02:59 AM   #536
James Felstead
Registered User
 
Join Date: Sep 2003
Posts: 71
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Quote:
Originally Posted by Vector7
Does anyone have a current status report on Floyd Landis? Where is he going?

Aparantly he was talking to CSC about a move there but Riis doesn't have enough cash to take on new riders - so it sounds like he's looking for a way out at least.

http://www.procycling.com/news.aspx?ID=706
"Riis also said that he had been offered the chance to sign Romans Vainsteins and Floyd Landis, who have both signed with Phonak. Riis turned down these options as well. "

James
James Felstead is offline  
Reply With Quote
Old 24-11.-2004, 06:02 AM   #537
homeycheese
Registered User
 
Join Date: Jun 2004
Location: Downtown in the ATL
Posts: 183
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Just keep watching the PR campaign in the US to see how much Tyler trys to hang onto his sponsors. It's now all about the $$$$ with Phonak apparently having spent nearly $800,000 USD so far to defend this SH_T!!!
homeycheese is offline  
Reply With Quote
Old 24-11.-2004, 06:12 AM   #538
homeycheese
Registered User
 
Join Date: Jun 2004
Location: Downtown in the ATL
Posts: 183
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Where are the heroes in cycling?

Look at what Nina Kraft said after her EPO scandal at the Ironman:

"The mistake cannot be rectified; I am going to bear all the consequences," she told the Hesse state radio.

"It's a matter of money, a lot of money, and ethics suffer in that case," her brother said on his Web site. "Nina tried [EPO] for the first time, without expertise or medical supervision."

"I never really rejoiced over the victory in Hawaii," Kraft said. "I was ashamed the entire time, especially in front of my family. I cheated."

"I did something stupid," she was quoted as telling Kurt Denk, organizer of the Ironman Germany competition.

When will cycling wake up?
homeycheese is offline  
Reply With Quote
Old 24-11.-2004, 05:01 PM   #539
Beastt
Registered User
 
Beastt's Avatar
 
Join Date: Sep 2003
Location: Arizona (USA)
Posts: 1,141
Send a message via AIM to Beastt Send a message via Yahoo to Beastt
Default Re: **** Breaking News: Hamilton Tested Positive? ***

Quote:
Originally Posted by homeycheese
Just keep watching the PR campaign in the US to see how much Tyler trys to hang onto his sponsors. It's now all about the $$$$ with Phonak apparently having spent nearly $800,000 USD so far to defend this SH_T!!!


So I guess this means you're staying neutral until both sides of the issue have fully presented their case?
Beastt is offline  
Reply With Quote
Old 25-11.-2004, 02:59 AM   #540
davidbod
Registered User
 
Join Date: Oct 2003
Location: Houston, TX
Posts: 712
Default Re: **** Breaking News: Hamilton Tested Positive? ***

davidbod is offline  
Reply With Quote

Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT +10. The time now is 01:50 PM.


Powered by: vBulletin Copyright © 2000 - 2008, Jelsoft Enterprises Ltd.
Copyright © 2001 - 2006 cyclingforums.com

Links to websites we like:
Pezcyclingnews | Cyclingnews.com | Wine Zone | iinet