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Chocolate Against Stress

admin — Tue, 16 Mar 2010 07:28:42 +0000

Dr Shock MD PhD

40 grams of dark chocolate per day reduces the urinary excretion of the stress hormone cortisol and it almost normalizes the stress related differences in energy metabolism and gut microbial activities between participants with low and high anxiety traits.

You are what you eat, it has been described how dietary preferences is associated with metabolic processes in healthy subjects. How does dark chocolate, by some considered to be a very healthy, affect the human metabolism? A number of studies have shown cardiovascular benefits of eating flavanol rich cocoa. In a recent post I discussed the possible underlying mechanisms of these cardioprotective properties of chocolate. The mechanism of action of chocolate at the molecular level are poorly understood. In this recent study the metabolic changes due to chocolate in healthy subjects was examined with metabonomics.

we have used proton nuclear magnetic resonance (1H NMR) spectroscopy and …

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External-memory shuffling in linear time?

admin — Mon, 15 Mar 2010 23:49:02 +0000

Daniel Lemire

You can sort large files while using little memory. The Unix sort tool is a widely available implementation of this idea. Files are written to disk sequentially, without random access. Thus, you can also sort variable-length records, such as lines of text.

What about shuffling? Using the Fisher-Yates algorithm also known as Knuth algorithm, you can shuffle large files while using almost no memory. But you need random access to your files. Thus it is not applicable to variable-length records. And indeed, the Unix sort command cannot shuffle. (It has a random-sort option, but it is not a shuffle. Meanwhile, the shuf command runs in RAM.)

A solution: Tag each record with a random number. Pick random numbers from a very large set so that the probability that any two lines have the same random number is small. Then use external-memory sorting. You can implement something similar as a …

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Scienceroll.com: Weekly Introduction

admin — Mon, 15 Mar 2010 22:54:02 +0000

Scienceroll

I would like to share my favourite and ongoing projects with you so I can give you a proper introduction to Scienceroll.com. You can also find me on Twitter or on Friendfeed.

For news and articles about the impact of web 2.0 on medicine and healthcare, please follow the Medicine 2.0 Friendfood room.

For news and articles about personalized medicine and genetics, please follow the Gene Genie Friendfeed room.

Medicine 2.0 University Course: This is the third semester of the first university course that focuses on web 2.0 and medicine for medical students. Now, almost 100 students attend the 20 slideshows through 10 weeks and they fill a survey out before and after the course.

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Chicks with chicks

admin — Mon, 15 Mar 2010 18:42:07 +0000

Agricultural Biodiversity Weblog

Proud to steal a great phrase when I find one, here are links to the original and two discussion — at Ethicurean and The Agricultural Law Blog — of a recent article on The Femivore’s Dilemma, about the prevalence of women in the new old food movement. Of course to my literal mind a femivore is one who eats females which, of course is generally what we do. Either females or ex-males. But the more profound ideas behind the article and the commentaries are fascinating. Personally, I’m not sure that there really is a gender divide, and it would be salutary to see this in a global context. Which gives me a reason to link to this little contribution to International Women’s Day last week.

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Financial Crisis: Are the banks really TOO BIG to save?

admin — Mon, 15 Mar 2010 12:30:20 +0000

Against Monopoly
Simon Johnson writes that unless we shrink the big banks drastically, the banking system will become “Way Too Big To Save” link here. Interesting counterpoint to “Too big to fail.” We are at the point where we can’t afford to bail the system out again, incredible as that may seem. The issue is that the banking system is no longer just that of the US and if we save one bank, we will have to save all the others as well–and we won’t have the resources to do it.

Johnson, who was International Monetary Fund’s Economic Counselor (chief economist) and Director of its Research Department and now teaches at the MIT Sloan School of Management, writes a blog and a constant flow of papers, and serves on the Congressional Budget Office’s Panel of Economic Advisers and as a senior fellow at the Peterson Institute for International Economics.

I will not try to repeat his argument. Read the original and the two other references he includes here and here.

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Measles week, part I: Introduction

admin — Mon, 15 Mar 2010 10:10:12 +0000

Mystery Rays from Outer Space

Zhong Kui, a Chinese god, punishing two gods of measles (1862)

I’ve talked before about measles incidence and the effect of vaccination. Now I’m going to spend this whole week talking about measles deaths, because I ended up with more than I could cover in one or two posts. So this is Part I of a five-parter.

A group of diseases which … even now are considered to be unavoidable are scarlet fever, measles, and whooping cough. … According to the statistics collected in the census of 1900, these three diseases were responsible for upward of thirty thousand deaths in the course of a year.”

–”The Conservation of the Child”, by Earl Mayo. in The Outlook. A Weekly Newspaper. Volume XCVII. January-April, 1911 (pp. 893-903)

That was the situation in 1911 and in the early 20th century generally, and for centuries before that. Almost every child caught measles, and a lot of them died. Measles wasn’t quite as lethal as smallpox, but it wasn’t too far behind:

Measles should no longer be considered a “minor” infection. It is a major illness causing a considerable mortality and a much greater morbidity among young children affected by it. ¹

(By the way, as well as citing my direct quotes in footnotes as usual, I’ve collected the 40-odd references I read while trying to figure this story out and put them up here.)

But, starting somewhere around 1915, that began to change. Very gradually (so gradually that it almost escaped attention) measles stopped being a fatal disease. In 1945, William Butler said:

In three-score years or so, during which the population of England and Wales has nearly doubled, the gross annual contribution of deaths from measles has fallen to about one-twelfth of the mean figure at which during several quinquennia it stood in the eighties and nineties of the last century. Nor is there reason to believe–on the contrary–that measles is now less prevalent than it was. It is still true that nearly everyone at one time or another has measles. ²

And the trend didn’t stop there. In 1945, about 163 out of every 100,000 measles cases died. In 1955, just 25 of 100,000 died, and it’s hovered around there since.

In other words, a person who caught measles in 1900 …

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Creating Predictably Beneficial AGI

admin — Mon, 15 Mar 2010 09:53:03 +0000

The Multiverse According to Ben
This is a sort of continuation of my immediately previous blog post, further pursuing the topic of goal-system content for advanced, beneficial AGIs.

My SIAI colleague Eliezer Yudkowsky has frequently spoken about the desirability of a “(mathematically) provably Friendly AI”, where by “Friendly” he means something like “beneficial and not destructive to humans” (see here for a better summary).

One of Yudkowsky’s ideas about specifying “Friendliness” is Coherent Extrapolated Volition (CEV), which I discussed in my previous post, along with a more modest and (I suggest) more feasible notion of Coherent Aggregated Volition (CAV).

If CAV is a wimped-out, less-ambitious, hopefully feasible version of CEV — then what I’ll present in this blog post is a wimped-out, less ambitious, hopefully feasible version of Schmidhuber’s Godel Machine (which is a theoretical, unlikely-ever-to-be-practically-realizable AGI system that uses theorem-proving to ensure its actions will provably help it achieve its goals).

I think that “provably Friendly AI” is an interesting and worthwhile goal to think about and work towards; but also that it’s important to be cognizant of the limitations on the possibility of such a thing. Much as I love math (I even got a math PhD, way back when), I have to admit the world of mathematics has its limits. First of all Godel showed that mathematics is only formally meaningful relative to some particular axiom system, and that no axiom system can encompass all mathematics in a consistent way. But more critically, the connection between complex mathematics and physical reality is based on science, and all of our science is based on extrapolation from a finite bit-set of observations (which I’ve previously called the Master Data Set — which is not currently all gathered into one place, though, given the advance of Internet technology, it soon may be).

Given the limitations of our understanding of the physical universe: at very best, a certain AI design could potentially be proven Friendly in the same sense that, in the 1800s, quantum teleportation, nuclear weapons, backwards …

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The Neuroscience of Anorexia Nervosa

admin — Mon, 15 Mar 2010 07:33:05 +0000

Dr Shock MD PhD

One of the most striking features of those suffering from anorexia nervosa is their perception of their bodies. You can put them in front of a mirror and they will still tell you they’re to fat when in fact they’re skinny. A recent publication in Nature Proceedings has an explanation.

This explanation is based on the fact that our spatial experience is based on the integration of two different kinds of input, two different sensory inputs within two reference frames. These two reference frames are the egocentric frame and the allocentric frame.
With the allocentric frame you can “see yourself engaged in the event as an observer would”, it’s the observer mode, you can see your self in the situation. This allocentric representation involves long term spatial memory mostly located in the hippocampus and the surrounding medial temporal lobes of the brain.

The egocentric frame is about the body being the reference of the first person experience. Seeing the event from his or her perspective as in normal perception, …

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Against Monopoly: Citizens United decision counterattacked

admin — Mon, 15 Mar 2010 02:34:02 +0000

Against Monopoly
The Washington Post has just given front page coverage to Murray Hill, a PR firm in Maryland that wants to run for public office link here. The article has a tongue-in-cheek character but it also has a serious objective–to make clear the absurdity of the Supreme Court determination in the Citizens United case that corporations have rights normally reserved to citizens, a position that is in fundamental conflict with common sense and precedent.

In quotations, the article says, “After the Supreme Court declared that corporations have the same rights as individuals when it comes to funding political campaigns, the self-described progressive firm took what it considers the next logical step: declaring for office.”
“It’s an opportunity to see this court opinion play out to its logical conclusion.”, “…the firm appears to be the first “corporate person” to run for office and is promising a spirited campaign that ‘puts people second, or even third.’” “I guess with a corporation, should someone go on vacation, like many of our current members of Congress, you’d have fill-ins to take their place.” …

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Amherst Restaurants

admin — Sun, 14 Mar 2010 21:48:35 +0000

Amherst Restaurants

Amherst restaurants is a sweet new initiative by the founders of Science Report that provides comprehensive restaurant listings and reviews to the area of Amherst, MA, USA. Check it out!