Prominent scientists have bad news for the White House about

[George Herold]

On Thursday, April 16, 2020 at 2:24:52 AM UTC-4, Mikko OH2HVJ wrote:

bloggs.fredbloggs.fred@gmail.com writes:

The specificity, complement of false positive, is what's killing them. I also can't believe how weak the sensitivity is either.

https://www.cnn.com/2020/04/14/health/coronavirus-antibody-tests-scientists/index.html

Yep. As an example, condider a situation with 96/94
specificity/sensitivity, population tested of 1e6 with 5% having
antibodies (which does not necessarily mean immunity or not contagious)

Roughly:
47000 get true positive result
3000 get false negative
955200 get true negative
39800 get false positive

So, 46% of positive results are false!

And those people may think they're safe for themselves and others, go
catch the virus and spread it during the asymptomatic phase.

--
mikko

Well, as long as there is no systematic error, give people two tests.

George H.

 

[Bill Sloman]

On Friday, April 17, 2020 at 12:40:26 AM UTC+10, bloggs.fre...@gmail.com wrote:

On Thursday, April 16, 2020 at 2:24:52 AM UTC-4, Mikko OH2HVJ wrote:
bloggs.fredbloggs.fred@gmail.com writes:

The specificity, complement of false positive, is what's killing them.. I also can't believe how weak the sensitivity is either.

https://www.cnn.com/2020/04/14/health/coronavirus-antibody-tests-scientists/index.html

<snipped exposition of a well-known problem which left out the equally well known solution - which is more than one test>

> That's exactly right.

In the sense that Fred Bloggs agrees with the superficial exposition presented.

> The false positives are much more dangerous. Why? There are LOTS of them, something on the order of 100x the number with exposure from infection, and they are susceptibles.

It doesn't matter until they get exposed to the virus.

>Susceptibles are the ones who catch, propagate, and perpetuate the disease..

If they get exposed to it.

> If they start lifting lockdown on the basis of a crummy antibody test with bad specificity performance, they're looking at a BIG rebound.

As if anybody would. Right now the antibody tests would be a back-up to the rather more reliable test for the presence of the virus, which is currently being used to check out people who might have got infected.

Lockdown isn't going to be lifted until a community hasn't had any new cases for
about a fortnight.

An antibody test would be useful to let the people making the decisions get a handle on how many people might have got the disease without showing symptoms, which would let them estimate how many undetected potentially infectious people might still be running around when they haven't detected a new case for a fortnight.

It doesn't have to be all that reliable to provide that information.

About 2% of the virus detecting tests seem to be coming out positive at the moment, but they are mainly being used on people who might have got infected.

> They have learned from the 1918 flu that the reason it disappeared so quickly is the virus ran out of significant numbers of susceptibles to infect.

Because the Spanish flu virus was close enough to an earlier strain that a lot of older people - thirty-plus - were immune from the last time that that strain had gone around.

This doesn't seem to be the case with Covid-19.

The Spanish also seems to have been less infectious than Covid-19, so the herd immunity level would have been easier to get to.

--
Bill Sloman, Sydney

 

[Martin Brown]

On 16/04/2020 17:41, George Herold wrote:

On Thursday, April 16, 2020 at 2:24:52 AM UTC-4, Mikko OH2HVJ wrote:
bloggs.fredbloggs.fred@gmail.com writes:

The specificity, complement of false positive, is what's killing them. I also can't believe how weak the sensitivity is either.

https://www.cnn.com/2020/04/14/health/coronavirus-antibody-tests-scientists/index.html

Yep. As an example, condider a situation with 96/94
specificity/sensitivity, population tested of 1e6 with 5% having
antibodies (which does not necessarily mean immunity or not contagious)

Roughly:
47000 get true positive result
3000 get false negative
955200 get true negative
39800 get false positive

So, 46% of positive results are false!

And those people may think they're safe for themselves and others, go
catch the virus and spread it during the asymptomatic phase.

--
mikko

Well, as long as there is no systematic error, give people two tests.

The failures you have to worry about are mostly from systematic errors.

People who have antibodies to something that is close enough to generate
a false positive response to the supposedly Covid-19 specific test.

A different entirely independent test will likely have a different error
profile so that could be used on the positive ones to discriminate. The
closer it is to orthogonal the better the final outcome.

Similar tactics are used in very mission critical software development
where completely independent isolated teams implement the specification
in the hope that they won't make exactly the same mistakes.

--
Regards,
Martin Brown

 

[Mike Coon]

In article <r7a91f$k8p$1@gioia.aioe.org>,
'''newspam'''@nezumi.demon.co.uk says...

Similar tactics are used in very mission critical software development
where completely independent isolated teams implement the specification
in the hope that they won't make exactly the same mistakes.

I accidentally did that years ago when I and the bloke at the next desk
wrote an algorithm to the same US Govt spec. It (the spec) included the
word "unique" referring to the digital values being examined. He
thought, logically, that meant that duplicated values should be
excluded. I thought the word just meant "distinct", which for digital
values hardly needed saying, so ignored it. My interpretation proved
correct (which is why I've remembered it!). We had to investigate why,
in practice, we got different results...

Mike.

 

[Ricky C]

On Thursday, April 16, 2020 at 2:54:25 PM UTC-4, Mike Coon wrote:

In article <r7a91f$k8p$1@gioia.aioe.org>,
'''newspam'''@nezumi.demon.co.uk says...
Similar tactics are used in very mission critical software development
where completely independent isolated teams implement the specification
in the hope that they won't make exactly the same mistakes.

I accidentally did that years ago when I and the bloke at the next desk
wrote an algorithm to the same US Govt spec. It (the spec) included the
word "unique" referring to the digital values being examined. He
thought, logically, that meant that duplicated values should be
excluded. I thought the word just meant "distinct", which for digital
values hardly needed saying, so ignored it. My interpretation proved
correct (which is why I've remembered it!). We had to investigate why,
in practice, we got different results...

Mike.

That particular error could have been found in a review of the design requirements by the same two people. Where both versions of the software intended to be run in the system?

--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209

 

[Flyguy]

On Wednesday, April 15, 2020 at 10:58:31 PM UTC-7, Bill Sloman wrote:

On Thursday, April 16, 2020 at 3:18:14 PM UTC+10, Flyguy wrote:
On Wednesday, April 15, 2020 at 10:14:33 AM UTC-7, Bill Sloman wrote:
On Thursday, April 16, 2020 at 2:15:42 AM UTC+10, Flyguy wrote:
On Wednesday, April 15, 2020 at 8:38:04 AM UTC-7, bloggs.fre...@gmail.com wrote:
The specificity, complement of false positive, is what's killing them. I also can't believe how weak the sensitivity is either.

https://www.cnn.com/2020/04/14/health/coronavirus-antibody-tests-scientists/index.html

You can see how many tests there are here:

https://www.finddx.org/covid-19/pipeline/

Antibody tests are "serology." Tons of Chinese manufacturers jumping on this bandwagon.

The far-left media is solely focused on testing quantities and completely ignoring testing accuracy.

What makes you think that?

This article provides as much insight into the issue as I have seen:
https://www.propublica.org/article/coronavirus-tests-are-being-fast-tracked-by-the-fda-but-its-unclear-how-accurate-they-are
An inaccurate test is worse than no test at all.

Not if you know - even roughly - how inaccurate it is

Hey Sloman, that is not my opinion, but the opinion of the head of the FDA.

It's your opinion about what the opinion of head of the FDA happens to be.

You happen to be a person of rather limited cognitive ability, and you frequently misunderstand what you read.

If you get a false negative you think you are OK and start infecting other unsuspecting people. Better that you don't know and isolate yourself.

Perhaps. But if you are asymptomatic, you wouldn't isolate yourself.

A test that has 5% false negatives would prevent 19 out of 20 of such infections.

We've just had a nurse in an aged care home who managed to infect six other staff and nine patients before she got tested. She really didn't know that she was infectious, and a test that would have sent her home 95% of the time would have helped.

Fly guy thinks that everybody should know that false negatives are WORSE than no diagnosis whatsoever, but is too "STUPID" to understand that he's wrong.

This isn't exactly what Flyguy posted, but it conveys as much of his message as is worth preserving.

The trouble with Flyguy's conclusion is that a false negative is the price you pay for getting quite a few more true positives.

It's worth the occasional false negative to get those true positives.

Realising that requires that you understand the idea of cost-benefit analysis, and that's way out of Flyguy's grasp. It was explicitly stated in what I've posted above, but Flyguy doesn't bother thinking about things like that, or anything much at all.

--
Bill Sloman, Sydney

SL0W MAN doesn't have any integrity - modifies others posts to change their meaning.

 

[Bill Sloman]

On Friday, April 17, 2020 at 3:44:44 PM UTC+10, Flyguy wrote:

On Wednesday, April 15, 2020 at 10:58:31 PM UTC-7, Bill Sloman wrote:
On Thursday, April 16, 2020 at 3:18:14 PM UTC+10, Flyguy wrote:
On Wednesday, April 15, 2020 at 10:14:33 AM UTC-7, Bill Sloman wrote:
On Thursday, April 16, 2020 at 2:15:42 AM UTC+10, Flyguy wrote:
On Wednesday, April 15, 2020 at 8:38:04 AM UTC-7, bloggs.fre...@gmail.com wrote:

<snip>

> SL0W MAN doesn't have any integrity - modifies others posts to change their meaning.

As if Flyguy knows what his posts mean. Their major information content is always the message that he doesn't know what he is talking about, and part of the problem is that they don't mean what he thinks they do - even ignoring the unavoidable message about his stupidity, which he's not in a position to detect.

--
Bill Sloman, Sydney

 

[John Larkin]

On Wed, 15 Apr 2020 08:37:56 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

The specificity, complement of false positive, is what's killing them. I also can't believe how weak the sensitivity is either.

https://www.cnn.com/2020/04/14/health/coronavirus-antibody-tests-scientists/index.html

You can see how many tests there are here:

https://www.finddx.org/covid-19/pipeline/

Antibody tests are "serology." Tons of Chinese manufacturers jumping on this bandwagon.

Today's paper reports that about 90 people in a SF homeless shelter
tested positive (presumably the active virus test) but have no
symptoms

In a Boston shelter,

"Of the 397 people tested, 146 people tested positive. Not a single
one had any symptoms."

So it is fairly contageous and not very dangerous.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Winfield Hill]

John Larkin wrote...

In a Boston shelter,

"Of the 397 people tested, 146 people tested positive.
Not a single one had any symptoms."

So it is fairly contageous and not very dangerous.

No, it's extremely highly contagious, and far more
dangerous than we like. We can try to ignore high
positive test counts, but they're infecting other
people and many are dying. A woman up the street,
who my wife walks her dog with, died two days ago.
She survived the ventilator, but after being taken
off, died from a brain injury. My wife was shaken,
having talked with her two weeks earlier. Then,
commiserating with the woman's neighbor, he revealed
that four of his co-workers died the previous week,
and he was worried for himself. They worked in the
produce distribution business, in Chelsea, which is
a new hot-spot. Then she talked with an old friend
of hers, who's in a nursing home, who revealed that
he had tested positive. Today's paper reveals that
30 residents have died there in the last few weeks.
Also a large fraction of the staff tested positive,
but not all have been able to be tested yet. We're
hoping her friend will be one who escapes with mild
symptoms. The number of people testing positive in
our town has doubled in the last week, despite that
we've been in near lock-down for about a month now.
Our hospital death rates are higher for older people,
but only by about 1.5x for middle aged, and about 2x
for the 20-35 group. So we're all in mortal danger.


--
Thanks,
- Win

 

[John Larkin]

On Fri, 17 Apr 2020 12:48:54 -0700, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Wed, 15 Apr 2020 08:37:56 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

The specificity, complement of false positive, is what's killing them. I also can't believe how weak the sensitivity is either.

https://www.cnn.com/2020/04/14/health/coronavirus-antibody-tests-scientists/index.html

You can see how many tests there are here:

https://www.finddx.org/covid-19/pipeline/

Antibody tests are "serology." Tons of Chinese manufacturers jumping on this bandwagon.

Today's paper reports that about 90 people in a SF homeless shelter
tested positive (presumably the active virus test) but have no
symptoms

In a Boston shelter,

"Of the 397 people tested, 146 people tested positive. Not a single
one had any symptoms."

So it is fairly contageous and not very dangerous.

https://www.zerohedge.com/health/navy-reports-alarming-stealth-transmission-rate-60-infected-carrier-crew-symptom-free

A virus that infects people for a couple of weeks and doesn't even get
noticed sounds like good news to me, but some experts would I guess
prefer that it kill more people or something.



--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Ricky C]

On Friday, April 17, 2020 at 3:49:04 PM UTC-4, John Larkin wrote:

On Wed, 15 Apr 2020 08:37:56 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

The specificity, complement of false positive, is what's killing them. I also can't believe how weak the sensitivity is either.

https://www.cnn.com/2020/04/14/health/coronavirus-antibody-tests-scientists/index.html

You can see how many tests there are here:

https://www.finddx.org/covid-19/pipeline/

Antibody tests are "serology." Tons of Chinese manufacturers jumping on this bandwagon.

Today's paper reports that about 90 people in a SF homeless shelter
tested positive (presumably the active virus test) but have no
symptoms

In a Boston shelter,

"Of the 397 people tested, 146 people tested positive. Not a single
one had any symptoms."

So it is fairly contageous and not very dangerous.

I guess the 150,000+ dead are just faking it.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

On Thursday, April 16, 2020 at 12:11:48 PM UTC-4, Bill Sloman wrote:

Lockdown isn't going to be lifted until a community hasn't had any new cases for
about a fortnight.

That's not what they're saying. They say lockdown will be lifted if there hasn't been an increase in daily cases for a fortnight.

--
Bill Sloman, Sydney

 

[Ricky C]

On Friday, April 17, 2020 at 5:54:24 PM UTC-4, John Larkin wrote:

On 17 Apr 2020 13:17:48 -0700, Winfield Hill <winfieldhill@yahoo.com
wrote:

John Larkin wrote...

In a Boston shelter,

"Of the 397 people tested, 146 people tested positive.
Not a single one had any symptoms."

So it is fairly contageous and not very dangerous.

No, it's extremely highly contagious, and far more
dangerous than we like. We can try to ignore high
positive test counts, but they're infecting other
people and many are dying. A woman up the street,
who my wife walks her dog with, died two days ago.
She survived the ventilator, but after being taken
off, died from a brain injury. My wife was shaken,
having talked with her two weeks earlier. Then,
commiserating with the woman's neighbor, he revealed
that four of his co-workers died the previous week,
and he was worried for himself. They worked in the
produce distribution business, in Chelsea, which is
a new hot-spot. Then she talked with an old friend
of hers, who's in a nursing home, who revealed that
he had tested positive. Today's paper reveals that
30 residents have died there in the last few weeks.
Also a large fraction of the staff tested positive,
but not all have been able to be tested yet. We're
hoping her friend will be one who escapes with mild
symptoms. The number of people testing positive in
our town has doubled in the last week, despite that
we've been in near lock-down for about a month now.
Our hospital death rates are higher for older people,
but only by about 1.5x for middle aged, and about 2x
for the 20-35 group. So we're all in mortal danger.

https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/coronavirus-disease-2019-vs-the-flu

"Normal" seasonal flu is much more deadly. But we've never got so
upset over that. Look at the chart about halfway down, influenza
stats:

https://en.wikipedia.org/wiki/Influenza

Why is this guy so dim?

We don't have a total number for COVID-19 because it's not over yet. We are already half way there and we haven't started ramping down the death rate.. Then there is the fact that the response has certainly reduced the infection and death rate. Had we not reacted the infection and death rate would be much higher.

The only downside I see to the lock down is that Larkin has even more time to post here. Someone invite him out to a coronavirus party.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Ricky C]

On Friday, April 17, 2020 at 5:42:09 PM UTC-4, bloggs.fre...@gmail.com wrote:

On Thursday, April 16, 2020 at 12:11:48 PM UTC-4, Bill Sloman wrote:


Lockdown isn't going to be lifted until a community hasn't had any new cases for
about a fortnight.

That's not what they're saying. They say lockdown will be lifted if there hasn't been an increase in daily cases for a fortnight.

That would completely undo the point of having the lockdown in the first place. The virus will go right back to exponential spreading if we don't remain isolated.

In fact, it's pretty obvious we aren't doing a very good job of isolation or we would see new infection counts dropping rather than maintaining.

Tell you what. If Trump goes out to Dupont Circle and shakes hands of people on the street without them having any pretesting or screening, I'll be happy coming out of my home for other than food. I'd like Larkin out there shaking hands as well.

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[John Larkin]

On 17 Apr 2020 13:17:48 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

John Larkin wrote...

In a Boston shelter,

"Of the 397 people tested, 146 people tested positive.
Not a single one had any symptoms."

So it is fairly contageous and not very dangerous.

No, it's extremely highly contagious, and far more
dangerous than we like. We can try to ignore high
positive test counts, but they're infecting other
people and many are dying. A woman up the street,
who my wife walks her dog with, died two days ago.
She survived the ventilator, but after being taken
off, died from a brain injury. My wife was shaken,
having talked with her two weeks earlier. Then,
commiserating with the woman's neighbor, he revealed
that four of his co-workers died the previous week,
and he was worried for himself. They worked in the
produce distribution business, in Chelsea, which is
a new hot-spot. Then she talked with an old friend
of hers, who's in a nursing home, who revealed that
he had tested positive. Today's paper reveals that
30 residents have died there in the last few weeks.
Also a large fraction of the staff tested positive,
but not all have been able to be tested yet. We're
hoping her friend will be one who escapes with mild
symptoms. The number of people testing positive in
our town has doubled in the last week, despite that
we've been in near lock-down for about a month now.
Our hospital death rates are higher for older people,
but only by about 1.5x for middle aged, and about 2x
for the 20-35 group. So we're all in mortal danger.

https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/coronavirus-disease-2019-vs-the-flu

"Normal" seasonal flu is much more deadly. But we've never got so
upset over that. Look at the chart about halfway down, influenza
stats:

https://en.wikipedia.org/wiki/Influenza



--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Jasen Betts]

On 2020-04-17, John Larkin <jlarkin@highland_atwork_technology.com> wrote:

On Wed, 15 Apr 2020 08:37:56 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

The specificity, complement of false positive, is what's killing them. I also can't believe how weak the sensitivity is either.

https://www.cnn.com/2020/04/14/health/coronavirus-antibody-tests-scientists/index.html

You can see how many tests there are here:

https://www.finddx.org/covid-19/pipeline/

Antibody tests are "serology." Tons of Chinese manufacturers jumping on this bandwagon.

Today's paper reports that about 90 people in a SF homeless shelter
tested positive (presumably the active virus test) but have no
symptoms

In a Boston shelter,

"Of the 397 people tested, 146 people tested positive. Not a single
one had any symptoms."

So it is fairly contageous and not very dangerous.

You're like a sky-diver with no parachute, you are leaping to a
conclusion

So far it hasn't significantly harmed these 90 or 146 people, it is
know to be asymptomatic for several days. when were these people
infected?

--
Jasen.

 

On Friday, April 17, 2020 at 5:55:57 PM UTC-4, Ricky C wrote:

On Friday, April 17, 2020 at 5:42:09 PM UTC-4, bloggs.fre...@gmail.com wrote:
On Thursday, April 16, 2020 at 12:11:48 PM UTC-4, Bill Sloman wrote:


Lockdown isn't going to be lifted until a community hasn't had any new cases for
about a fortnight.

That's not what they're saying. They say lockdown will be lifted if there hasn't been an increase in daily cases for a fortnight.

That would completely undo the point of having the lockdown in the first place. The virus will go right back to exponential spreading if we don't remain isolated.

In fact, it's pretty obvious we aren't doing a very good job of isolation or we would see new infection counts dropping rather than maintaining.

Tell you what. If Trump goes out to Dupont Circle and shakes hands of people on the street without them having any pretesting or screening, I'll be happy coming out of my home for other than food. I'd like Larkin out there shaking hands as well.

There are a lot of people saying there's lots of other stuff killing way more people than the worst estimate of COVID-19 deaths, and we don't lockdown over those. So it's plain stupid to even have a lockdown.

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[Ricky C]

On Friday, April 17, 2020 at 8:18:21 PM UTC-4, bloggs.fre...@gmail.com wrote:

There are a lot of people saying there's lots of other stuff killing way more people than the worst estimate of COVID-19 deaths, and we don't lockdown over those. So it's plain stupid to even have a lockdown.

There are lots of people saying the earth is flat, we never went to the moon, the government has planted tiny transmitters in your brain...

Like I said, somebody show me how safe it is by putting all the decision makers in Dupont circle so anyone in DC can shake their hands. Then I'll believe it's not worth having a lock down to prevent millions of deaths around the globe.

Like the flat earthers, there are a lot of people who don't understand simple math weighing in on the pandemic. Like Larkin.

I can't help but notice he is following all the same guidelines as everyone else. He also isn't making any projections of what will happen and doesn't seem to understand what would have happened if we didn't take the measures we did.

We don't seem to be able to actually follow rules enough to stop this infection from spreading throughout the population 30,000 per day. Lift the shut down and that number will return to an exponential rise.

I do see governors who seem to have some idea that we need to lift the shut down carefully and open businesses in ways that won't spread the virus. But we can't change anything until we get the infection rate under control and stop the daily death rate from taking off as it is still doing.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[mpm]

On Wednesday, April 15, 2020 at 2:36:13 PM UTC-4, Martin Brown wrote:

No. Game shows are only used to choose the US President.

Are you sure it's not more like one of those late-night Lotto drawings on TV?

 

[Phil Hobbs]

On 2020-04-17 20:51, mpm wrote:

On Wednesday, April 15, 2020 at 12:00:59 PM UTC-4,
jla...@highlandsniptechnology.com wrote:

How do you get to be a Top Scientist? Is there a game show for
that?


No, but there's a search engine for it. Why, with ten minutes over
coffee and a browser, I can become an expert in cubic Boron
arsenide.

In 20 minutes, I could build and install a pacemaker. "Oh shit, I've
got to get some rosin-core solder and Radio Shack closes in half an
hour."

They closed three years ago.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com