wastra

Yes, I agree this is vastly over-engineered. There are commercial solar farms that actively point toward the sun, but many (most?) do not, because they may fail. Before medicine, I studied and worked in renewable energy: in medicine, simplicity in critical engineering problems is more obviously important.

In this solar project, the metric should be a comparison to the yield from pointing at the sun based on lat,long, and (earth) time.

Really, the analysis would have to include anticipated costs of installation and maintenance in comparison to a dumb array.

Perhaps the ingenious author could consider xy or xyz movement in an intermittently shadowed environment instead of 2-axis rotation. This might be be a better job for machine learning, or just a well-known control system problem.

Physician, anesthesiologist speaking. Intravenous phenylephrine widely used, effective. No good in stomach.

Doctors struggle to harness all the historic use and evidence for treatments, sometimes based on great evidence. Often evidence is the best that can be had given available resources.

Drug companies hiding data (derived from volunteers and patients) is wrong, and a problem. Selective publishing of only positive findings in medical journals is common. Careers depend on publications. But despite these pressures, most doctors think hard about these issues, and do their truthful best for the patient in front of them, given the imperfect knowledge available.

OTC labeling is deceptive at best. Placebo only works for a few things.

My points all apply, even if I thought it did not warrant pursuing to the full text. I did not state the article was wrong, although I think it is quite likely to be worthless, and therefore not worth my time.

Temporary or permanent disability is also important.

As I won't pay Elsevier to read this article, I can't evaluate the (likely) methodolgical failings. Even major journals sometimes let papers with significant methodological flaws through, (e.g. the disastrous mistake of publishing the vaccine-autism fraud, which has cost many lives).

I do retrospective research of a different kind, and struggle with making causal inference from non-experimental data. This is an inescapable philosophical and scientific problem, and the very fact they talk about a "causal channel" (novel verbiage to me, btw) raises an eyebrow.

As a starting point, the publisher, SSRN, recently sold out to the Elsevier monster. SSRN, according to first line of its FAQ, "is a platform for the dissemination of early-stage research."

Why is this research "early stage?" I suggest it simply failed to meet submission standards for more reputable journals. This is hardly breaking news, likely just low quality work.

If I cared more, I would also, in addition to reviewing the actual article, check the credentials of the authors for bias due to religious, business, funding or political affiliations.

The authors force us to consider the competing implicit demands that people may procreate without external constraint, and that all children's welfare is to a degree the responsibility of society. On the first, what law doesn't (somehow, via a "causal channel!") affect people's ability to procreate?

I am an anaesthetia doctor. There is, in fact, only mixed evidence of checklists actually helping in various health systems around the world. At a national level, Scotland began using checklists, but the whole health system and population is always in flux, so attribution of such a big change just to checklists is bold. It may also be that checklists do (temporarily?) improve broken or highly resource constrained peri-operative care: but this leaves open the question as to whether correcting underlying staff/morale/equipment/logistic problems would have, or should, play a role.

Checklists I have seen used during my career are often rushed through, with more time usually being spent appropriate to the complexity of a situation. Local culture will strongly impinge on effectiveness of (yet another?) checklist. The safety culture in medicine is improving dramatically, but there is tension between protocolizing everything into checklists, and individualizing care to each patient. AI will be part of the solution to this.

An important checklist commonality in medicine is the request that _anyone_ should speak up if they think something is wrong. In analyzing situations where patients were harmed, e.g. wrong side surgery, it is common to hear that someone, a nurse, a technician, did notice, but was not empowered to speak up. As a doctor, I am used to the power to speak up and act, but I value others' eyes in many situations. More complex and highly dynamic medical situations will always require the attention, knowledge and skill of those involved.

The outcome measure was whether the participants felt good. The authors dangle the _association_ of this with actual longevity, which of course means nothing whatsoever in the context of this very weak study in an irrelevant journal.

The incorrect assumption your readers are making is that heart surgery is a good thing in all cases. America is the leader in futile medical procedures: it may well be a good thing to have fewer risky procedures on patients who were more likely to be harmed. "primum no nocere" may be advanced!

This and many other points are left unaddressed by the authors. They fall at the first hurdle, so I hope this discussion can move on to some of the other interesting things people have mentioned.

They could have gone with: "Sloppy scientists delude themselves about unlikely hypothesis"

People repeating the fiction that "low blood sugar puts one in a bad mood" puts people in a bad mood when they haven't had sugar in the last twenty minutes. We evolved in a low sugar world and did just fine: or was everyone moody from 200,000 years ago until about a century or two ago?

A lot of peer reviewed literature is also junk, and occasionally non-peer-reviewed papers are breathtaking.

One of my favourite (peer reviewed) articles ever is: http://journals.plos.org/plosmedicine/article?id=10.1371/jou...

Yes, this is another flaw, but there are much bigger flaws in their work!

Also, they only fasted people for 3h. I've sucked a lot of junk out of peoples' stomachs who have had longer fasts, so this is not even a glycogenolisis phase: they could easily have been digesting food still. The participants were students, so maybe some had drunk alcohol, which, like a ketone is a two-carbon molecule...

People often say this, but I'm not yet convinced it has a fully or even partially physiologic basis.

One way to do an experiment would be to fast someone for 48h (about when you completely run out of glycogen, and ketones start to ramp up from fat catabolism), and while fasting, infuse glucose, blinded, into them. I wonder whether people could tell whether they are getting IV glucose or IV saline, just by how they feel. Maybe someone already did this experiment.

This is an interesting point. As others addressed the main issues, I would just add that dieting does not need to be continuous exercise of will power. It may just take will power in establishing an environment not surrounded by unhealthy food, e.g. when shopping.

I would not relate this point to serum glucose in any way, however.

This is one of the earliest tricks of the paper. In the initial discussion they cite numerous authors on why low glucose, i.e. hypoglycemia, affects cognition. I have seen many hypoglycemic diabetics in bad trouble from this. However, the author then silently moves on to asserting that lower levels within the normal glucose range also have this effect, but without any supporting evidence.

In addition, the commonly stated myth that people "feel hypoglycemic" could be easily disproved in 99% of people if it was worth the time and effort to do so. The awareness of hunger, awareness of time since last meal, and the nocebo suggestion that such a thing as hypoglycemia in (most) normal people exists. It is a real thing with some medical problems, and a very few otherwise healthy people, but far overstated.

If we're into anecdotal levels of evidence, I eat once a day, and _feel_ the least energetic after eating, for 30-60 minutes.

I agree. And they don't even show there was a decline in their initial experiment on which their entire chain of reasoning is based:

control group glucose before: 102+/-21, after 103+/-18 intervention glucose before: 107+/-21, after 101+/-18 (+/-SD)

Wide confidence intervals, and critically important to note, the pre-test intervention baseline of 107 is much higher than all the other numbers. They do not show that this is not by chance, i.e. null hypothesis of no difference is not rejected. They don't state a P-value (even though this is now out of vogue, the paper is ten years old), likely because it is greater than the mythical 0.05.

These numbers are laughable, so much so that I do not even think they are fabricated. They also quote two decimal places even though their SD is ~20! Every detail of this paper is amateurish.

I also have a problem with the ethics of this study. They recruited students and paid them in course credits. This strikes me as being coersive.

I'm sure I could find more gaping holes in their reasoning, statistics, but I hope I've already shot it down. I'm not a neuroscientist by any means, but I do digest a lot of scientific papers. My guess for a real cause of this effect would be neurotransmitter depletion in key neurons involved in self-discipline.

I'm a physician. There are a lot of problems with the original article.

The body is excellent at maintaining glucose concentration in the blood with food or with days of fasting. Glucose is the primary short-term energy source for most cells. The brain's energy requirements vary very little with "thinking" despite the assertions to the contrary in the introduction of this article. PET works by noting the slight transient increases in some brain regions with active thought, but moments later (as that 20% of blood flow goes swishing through the brain) more glucose is available. Meanwhile you are digesting sugars and carbohydrates, and your liver is supplying most of your fresh glucose if you are a fasting adult.

Already, before reading the article, I have a low pre-test probability of their hypothesis being true, so they need extraordinarily strong evidence to make their point. Instead, there is a very weak chain of experiments, poorly reported, with borderline statistical significance. Poor charts, no tabulated results, just terrible.

The primary problem is that they assert that glucose fluctuations occur due to the exercise of willpower. They try and fail to show this with their first experiment. However, their "results and discussion" combined section shows that their control group before and after glucose were very close to their post-intervention group glucose. p327 para 1.

This shows how weak their statistics and data are, and from this point, you can throw the whole study in the trash.

Please also remove the unsourced (and untrue) claim about the present, too!

I wrote a thesis ten years ago which examined the engineering and economics of a more simple kite/glider pair system. Aerodynamically, it can be stable and self-correcting, which I modelled and prototyped, but this may not be an optimal design and launching is hard due to lower (and different direction) ground wind and boundary layer issues.

The drone-like addition adds control complexity, but appears to ease take-off and can probably reduce strain in flight and improve efficiency, despite the aerodynamic cost.

Tower wind turbines have enormous costs and engineering trade-offs: the generator is in the nacelle up high, adding structural cost to the tower, which, at 150m+ nowadays, is a big deal; not to mention the rotors which span the area of a sports stadium. This doesn't scale, whereas kites do, because the tower/blade height/length cost is gone, the generator sits on the ground, and can be bigger (easy access, cheaper, heavier magnets, among other benefits).

Maintenance (and finance of turbine project bearing this in mind) is huge. Servicing an offshore turbine is weather limited and expensive even if you can get there. For kites, just reel them in by pulling more power off the generator to wind in the kites. If they are offshore, then sail the boat (?autonomously) back to a harbor. The list goes on and on, and amazing possibilities open up with a moment's thought.

Agreed with responder that it is early days for the technology, but I expect strong progress through up learning curve from this early stage. Good luck Makani!