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So no false negatives. But how many false positives? TFA doesn't say.

The false positive rate is 18%.

So if the test says you don't have it, you don't have it. If it says you do have it, there is a 1 in 5 chance that you don't.

Here is the original paper

An obvious next step is to train the NN on a lot more data.

http://press.rsna.org/timssnet... The official press release details the actual brain area in which this metabolism change was studied. The anterior cingulate cortex is involved in pretty much everything (attention, task-switching, self-monitoring, etc), so not super surprising but pretty cool nonetheless. Also not really "controversial", as any substantial behavioral change will necessarily produce corresponding changes in brain activity...Good to see that it can be reversed though.

Fortunately or unfortunately, that's not the point. There have been demonstrations to that affect but no one is willing to risk it.

Since you are obviously cherry-picking your sources again (which I have pointed out to you before), let me add some recent sources from highly respected journals about the risk of low-dose radiation. Ofcourse, according to Mr. D. all these journals just publish pseudo-science. Reminds me of the old joke with the wrong-way driver.

"... First, it is clear that we have now passed a watershed in our field, where it is no longer tenable to claim that CT risks are "too low to be detectable and may be non-existent" (5). A large well-designed epidemiologic study has clearly shown that the individual risks are small but real..."
Journal: Radiology
Link: http://pubs.rsna.org/doi/full/...

"...We noted a positive association between radiation dose from CT scans and leukaemia (...) and brain tumours (...)."
Journal: The Lancet
Link: http://www.sciencedirect.com/s...

"Conclusions The increased incidence of cancer after CT scan exposure in this cohort was mostly due to irradiation. ..."
Journal: British Medical Journal
Link: http://www.bmj.com/content/346...

"The study supports the extrapolation of high-dose rate risk models to protracted exposures at natural background exposure levels."
Journal: Leukemia
Link: http://www.nature.com/leu/jour...

And with respect to Fukushima there were recent estimates from a Stanford guy:
"We estimate an additional 130 (15â"1100) cancer-related mortalities and 180 (24â"1800) cancer-related morbidities incorporating uncertainties associated with the exposureâ"dose and doseâ"response models used in the study. We also discuss the LNT model's uncertainty at low doses. .... Radiation exposure to workers at the plant is projected to result in 2 to 12 morbidities. An additional [similar]600 mortalities have been reported due to non-radiological causes such as mandatory evacuations."
Journal: Energy & Environmental Science
Link: http://pubs.rsc.org/en/content...

Radiological Society of North America (RSNA): High School Football Players Show Brain Changes after One Season - even without concussion.

1) Absorption of the xray beam is not just based on a material's electron density. The contrast media we use today have a k-shell energy in the mid 30 kev which causes a sharp increase in the amount of absorption due to the photoelectric effect proportional to compton scatter. This means they have a higher absorption at these energies than their atomic number would indicate. Gallium's atomic number is lower than iodine's and its k edge is at 10 kev rather than in the 30s. I find it hard to believe that it provides better contrast resolution AT SIMILAR DOSES than iodine based contrast media. The actual paper (http://arxiv.org/ftp/arxiv/papers/1311/1311.6717.pdf) does not discuss the dose of gallium administered but based on the images I would assume they completely filled the coronary vasculature with gallium. This would not be compatible with life.

2) We have administered gallium 67 salts intravenously for medical imaging for decades, although it is out favor these days due to relative inferiority to newer imaging agents such as FDG-F18. Since the isotope is emitting photons out of the patient rather than us shooting photons into the patient and depending on gallium to absorb them, the doses are much lower for the type of imaging currently used than they would have to be for the proposed use as a contrast agent. As described above, completely replacing the blood with gallium to perform conventional or CT angiography would not be compatible with life.

Source: Radiology Society of North America physics modules http://www.rsna.org/RSNA/AAPM_Online_Physics_Modules_.aspx (massive paywall)

I guess all the evidence points to using copious amounts of herbs is a good idea, health-wise. On the other hand it doesn't really make a case for avoiding synthetic preservatives.

Nope, the only case for that is fear of the unknown. Or, stated another way, the devil you know...except that in this case the devil you know happens to be rather good for you

In fact, if we focus on the anti-microbial properties of herbs and spices, synthetic (anti-microbial) preservatives should also sound like a good idea. If on the other hand herbs and spices are beneficial due to vitamin and mineral content, synthetic preservatives lose out completely.

You're still leaving out details, though. What other effects could there be? (Bleach also has anti-microbial properties, and even ignoring the effect on taste I'd still prefer to add herbs to bleach.) How does either anti-microbial agent break down in the stomach, or, if they don't, affect our gut bacteria? (Could you pass the penicillin?)

You seem to have mentioned the 'one' exception [...]

Alrighty then.

This argument would work if we would experience rewards from eating things with certain other nutrients (vitamins, minerals and such), which I believe is not or hardly the case. I.e.: I'm not so sure those other signals even exist.

It does look like I have to acquiesce that I'm standing on shaky ground on this general idea. However, I have found some evidence that some vitamin or mineral deficiencies can affect dietary preference for supplemented feed in rats, sheep, and hens. While this behavior may not represent a "craving" as addressed by the above articles you linked to, it does support the idea that food selection can be driven by nutritional need. Now, all I need to do is ask those researchers to repeat the experiments when sugar was added to all of the tested feeds. I'll get back to you on that one...

The following is a purely subjective, personal anecdote, but it has likely contributed to my belief that our nervous systems might develop interesting interpretations of whatever signals may be triggered by the various stages of digestion. There are certain foods that I will suddenly experience what I'll call an "anti-craving" for--that is, something in my brain/body just makes me not want to eat it for at least a couple days. This has happened to me with beef heart and chicken-of-the-woods mushrooms. I have no idea what was behind that feeling, but I can tell you it was pretty strong, and pretty food-specific (it's not like I wasn't hungry for the next couple days or anything).

Other than the above, my general impression from having studied perception and neuroscience is to never underestimate what types of signals our brains can learn to work with. For instance, did you know that trained radiologists can detect the presence of lesions in an x-ray image with better-than-chance ability when the image is only displayed for 1/5 of a second without even consciously knowing what it was that they detected? (The latter part of that statement comes from having spoken to the PI of that study). I'm not saying that there are perceptual nutrient receptors (there are, however, sweet receptors in the gut), just that there are perceptual differences that can occur due to a sufficiency or deficiency of various nutrients via their action in all systems in the body, and that if there's a signal, the brain will learn to use it.

I'm pretty sure that's not true. Mainly from experience, but a little googling also seems to indicate that there is ei

OK, let's play your game.

According to this study, the dose of typical FDG PET-CT scan protocols is between 13.45 mSv and 32.18 mSv depending on gender and the CT protocol used. Most of that is attributable to the CT scan which is delivered in a few seconds. But that's not where I'm going. Let's just pretend for a moment that the CT wasn't acquired.

Of those doses, 6.23 mSv are due to the F18-FDG. That is not something that could potentially get into your body, but actually injected into your bloodstream and it delivers the 6.23 mSv in just a handful of hours (the half-life of F18 is 109.8 minutes). Compare that with the 1 mSv dose spaced across a full year and due to radioisotopes of which only a fraction actually get into your body.

And yet the lifetime attributable risk (LAR) of cancer incidence due to the PET-CT study for those doses is between 0.163% and 0.514% for a 20-year-old in the US –and that is including the CT scan!

Of course you shouldn't get a PET-CT scan unless there is a very good medical reason for it, but my point is: even if it's due to radionuclides decaying inside your body, a dose of 1 mSv delivered throughout a year is rather paltry.

Your understanding of the scientific method is a bit naive. Lots of incorrect results pass peer review even in the most prestigious journals and sometimes are discovered as being incorrect only years later (or never)... because there is always some "fuzziness" in real-world experiments or data analysis. Were the experiments designed correctly? Was the data read correctly? Were there any errors in the analysis (mathematical or otherwise)? Is the logic leading to the conclusions correct? Peers who read the papers may or may not spot the errors... sometimes because the errors are subtle, and sometimes because even the smartest peers don't fully understand the research in the first place. (And with regard to the this Norwegian government research... well it hasn't even been peer-reviewed yet.)

There are a lot of steps in research and in each of the stops bias can creep in even if the researchers are honest and well-intentioned.

For more about this see, i.e.:
http://www.nature.com/news/beware-the-creeping-cracks-of-bias-1.10600
http://www.niam.scarp.se/download/18.71afa2f11269da2a40580007299/Huesseman%2B-%2BBiases.pdf
http://radiology.rsna.org/content/238/3/780.full
http://en.wikipedia.org/wiki/Experimenter's_bias

...and lots more. In some areas of research (specifically bio-medical) there have been estimates (based on meta-analysis) that as much as half of all published results are wrong, and mostly along the lines of the researchers inherent biases.

The page 5 of the original article PDF has a size comparison of disected specimens. The treated mice testes weight is roughly halved but the size is 2^(1/3) ~ >0.70 of the untreated ones.

There is a meassurement device called Prader orchidometer that works by comparison with standarized orbs. It's very difficult to get an accurate size/volume in vivo without using ultrasounds and if even the orchidometer method is not precise much less expect that anybody could notice a significant difference just looking at them.

Certainly after some time not even yourself will notice at all. Definitely noticeable if meassured or compared side by side, but most probably irrelevant for a partner. The major issue may be the own psychological selfesteem burden that some insecure people could have of knowing that their testes shrank a bit, but far worse and by large would be that you got instead a vasectomy and later couldn't reverse it.

Always could do nothing and let all the responsability to your girlfriend/wife behaving like a macho(TM) or just ask for her opinion about it and decide together since also are "her nuts".

A friend of mine works in radiology research. He holds the same opinion.

I stayed at a Holiday Inn last night, and I wholeheartedly agree.

Okay, if you prefer:

http://radiology.rsna.org/content/259/1/6.extract
http://rpd.oxfordjournals.org/content/145/1/75
http://archinte.ama-assn.org/cgi/content/full/171/12/1129
http://www.propublica.org/article/scientists-cast-doubt-on-tsa-tests-of-full-body-scanners
http://www.sciencedirect.com/science/article/pii/S0267364908000708

Find me similar articles from professionals in the relevant fields and not associated with the TSA that say the opposite.

Radiologists experienced dangerous occupational exposures prior to 1950. Exposure control and monitoring operations are significantly more advanced and it is not unsafe to be a radiologist. Thanks for the FUD though.
http://radiology.rsna.org/content/233/2/313.full

:-) I know I do: http://radiology.rsna.org/content/248/3/962.abstract

I don't have firsthand experience, but here's one example study. No mention of what kind of "discomfort" the patients experienced, but I'd expect pins-and-needles sensations. This is from high gradient rate-of-change.

For head motion, again, I don't have first-hand experience, and I'm having a harder time Googling up examples. I have the impression that it's mostly dizziness/vertigo. As I said, I'd assumed that it was an induction effect on axons, but thinking about it more, I wonder if it's diamagnetic force on the fluid in the semicircular canals. 7T isn't enough to levitate, but it's certainly enough to exert force.

For proof that magnetic fields can influence neural activity, you need only look at the burgeoning field of transcranial magnetic stimulation. Those field rates of change are orders of magnitude beyond anything you can coax out of an MR scanner, though.

People have been. Perhaps not for radiation therapy, which tends not to leave residual radiation, but there are plenty of nuclear medicine diagnostic tests that, by design, cause a person to emit detectable radiation for hours or days afterwards. For most of these tests, the patient is injected with a radioisotope that concentrates in a particular part of the body, which is then imaged. The list of isotopes that get used is really mind-boggling. Most have half-lives measured in minutes to hours, but the amount of radiation emitted after many half-lives, while not medically relevant or useful, is still enough to trigger radiation detectors DHS has deployed. Some of them can be detected weeks after administration (e.g., Tl-201)

Here is at least one article on the subject. Here is another, and a third. Another (which you probably can't find for free, sorry) would be Dauer et al. in the J of Nuclear Cardiology (vol 14, no 4, pg 582) on Thallium-201 stress tests and homeland security.

So, in short, this kind of thing happens.

PREVIEW BUTTON! http://www.rsna.org/publications/rsnanews/dec04/ip od-1.html

There is not only other hardware already out which does the same thing (and problably better) but he also says he can use "Apples Dot Mac" system to store images of patients to share with colleagues. No privacy problems there. And this was actually reported back in DECEMBER OF 2004. If you bother to read that article, the poor guy only has a 20GB HD on his laptop, so he thinks the 40GB on his iPod is some miracle. Idiot. Plus he uses iChat (I'm sure that is really secure to use over the Internet) to share the images online also. Chalk up another non-innovative use that gets posted up to slashdot that a ton of people are going to ooh and aah over for no good reason.

Although this has been long known in the security "biz", in fact there is growing body of evidence to give this some scientific basis such as this recent article about MRI-ing folks when telling lies...

http://www.rsna.org/daily/monday/fmri.html

In this specific article they allude to the fact that you have to do some "positive control questioning" to have a proper calibration. Of course customs, immigration, and police have been using these techniques for quite a while without scientific validation.

Of course I'm a bit biased because I believe this is a valid questioning technique. Some people object to any questioning whatsoever and I doubt they would ever be convinced this is a good thing to do. Sadly I also believe there is a correlation to those same people and the size of their egos about their importance in the world (e.g., even though they let me slide by, if I don't stop this invasion of privacy, nobody will)...

Your reference for this? The first few references I found on Google all disagree with you:

• the human eye is more sensitive to luminance than chrominance
• We know that the human eye cannot perceive differences in color as well as it can differences in intensity.
• The human eye is more sensitive to brightness (gray scale data) variations than to hue variations
• the human eye is much more sensitive to luminance than chrominance
• the human eye is much more sensitive to brightness variations in gray-scale than to color variations

something you should go and check out is a trade show RSNA which shows up medical scanners and other imaging hardware that can be usefull to you.
RSNA is held in chicago.

-rev