Econstudentlog

Random stuff

It’s been a while since I posted anything here so I figured I should at least post something…

i. A few Khan Academy videos I watched a while back:

(No comments)

(Bookmark remark: (‘Not completely devoid of slight inaccuracies as usual – e.g. in meningitis, neck stiffness is not as much as symptom as it is a clinical sign (see Chamberlain’s symptoms and signs…))’

(Bookmark remark: ‘Very simplified, but not terrible’)

(No comments)

ii. I previously read the wiki on strategic bombing during WW2, but the article did not really satisfy my curiosity and it turns out that the wiki also has a great (featured) article about Air raids on Japan (a topic not covered in a great amount of detail in the aforementioned wiki article). A few random observations from the article:

“Overall, the attacks in May destroyed 94 square miles (240 km2) of buildings, which was equivalent to one seventh of Japan’s total urban area.”

“In Tokyo, Osaka, Nagoya, Yokohama, Kobe, and Kawasaki, “over 126,762 people were killed … and a million and a half dwellings and over 105 square miles (270 km2) of urban space were destroyed.”[136] In Tokyo, Osaka and Nagoya, “the areas leveled (almost 100 square miles (260 km2)) exceeded the areas destroyed in all German cities by both the American and English air forces (approximately 79 square miles (200 km2)).”[136]

“In financial terms, the Allied air campaign and attacks on merchant ships destroyed between one third and a quarter of Japan’s wealth.[289]

“Approximately 40 percent of the urban area of the 66 cities subjected to area attacks were destroyed.[290] This included the loss of about 2.5 million housing units, which rendered 8.5 million people homeless.”

iii. A few longer lectures I’ve watched recently but did not think were particularly good: The Fortress (GM Akobian, Chess), Safety in the Nuclear Industry (Philip Thomas, Gresham College), War, Health and Medicine: The medical lessons of World War I (Mark Harrison, Gresham College – topic had potential, somehow did not like ‘the delivery’; others may find it worth watching).

iv. I play a lot of (too much) chess these days, so I guess it makes sense to post a little on this topic as well. Here’s a list of some of my recent opponents on the ICC: GM Zurab Azmaiparashvili, IM Jerzy Slaby, IM Petar Gojkovic, GM Goran Kosanovic, IM Jeroen Bosch, WGM Alla Grinfeld. I recall encountering a few titled players when I started out on the ICC and my rating was still adjusting and stabilizing, but now I’ve sort of fixed at a level around 1700-1800 in both the 1, 3 and 5 minute pools – sometimes a bit higher, sometimes a bit lower (and I’ve played relatively few 5 minute games so far)). This is a level where at least in bullet some of the semi-regular opponents I’ll meet in the rating pool are guys like these. I was quite dissatisfied with my play when I started out on the ICC because I hadn’t realized how tough it is to maintain a high rating there; having a closer look at which sort of opponents I was actually facing gradually made me realize I was probably doing quite well, all things considered. Lately I’ve been thinking that I have probably even been doing quite a bit better than I’d thought I had. See also this and this link. I’ve gradually concluded that I’m probably never ‘going back’ now that I’ve familiarized myself with the ICC server.

And yes, I do occasionally win against opposition like that, also on position – below an example from a recent game against a player not on the list above (there are quite a few anonymous title-holders as well on the server):

easy-e
Click to view full size – the list to the lower left is a list of other players online on the server at that point in time, ordered by rating; as should be clear, lots of title-holders have relatively low ratings (I’m not completely sure which rating pool was displayed in the sidebar at that time, but the defaults on display for me are 5- or 3-minutes, so for example the international master ‘softrain’ thus had either a 3 or 5 minute rating of 1799 at that time. Do note that ICC requires proof for titles to display on the server; random non-titled players do not display as titleholders on the ICC (actually the formally approved titled accounts obviously do not account for all accounts held by title-holders as some titled players on the server use accounts which do not give away the fact that they have a title).

Here’s another very nice illustration of how tough the X-minute pools are (/how strong the players playing on the ICC are):

Wang Hao
Again, click to view in full size. This is Chinese Grandmaster Wang Hao‘s ICC account. Wang Hao is currently #39 on the FIDE list of active chess players in the world, with a FIDE rating above 2700. Even his 5-minute rating on the ICC, based on more than a thousand games, is below 2300, and his current 3 minute rating is barely above 2000. With numbers like those, I currently feel quite satisfied with my 1700-1800 ratings (although I know I should be spending less time on chess than I currently do).

v. A few words I’ve recently encountered on vocabulary.com: Anaphora, usufruct, mimesis, amanuensis, peculate, elide, ataraxia, myrmidon, velleity.

vi. A few other wiki links: Fritz Haber, Great Stink (featured), Edward Low (a really nice guy, it seems – “A story describes Low burning a French cook alive, saying he was a “greasy fellow who would fry well”, and another tells he once killed 53 Spanish captives with his cutlass.[6]“), 1940 Soviet ultimatum to Lithuania (‘good article’).

vii. A really cute paper from the 2013 Christmas edition of the British Medical Journal: Were James Bond’s drinks shaken because of alcohol induced tremor? Here’s the abstract:

Objective To quantify James Bond’s consumption of alcohol as detailed in the series of novels by Ian Fleming.

Design Retrospective literature review.

Setting The study authors’ homes, in a comfy chair.

Participants Commander James Bond, 007; Mr Ian Lancaster Fleming.

Main outcome measures Weekly alcohol consumption by Commander Bond.

Methods All 14 James Bond books were read by two of the authors. Contemporaneous notes were taken detailing every alcoholic drink taken. Predefined alcohol unit levels were used to calculate consumption. Days when Bond was unable to consume alcohol (such as through incarceration) were noted.

Results After exclusion of days when Bond was unable to drink, his weekly alcohol consumption was 92 units a week, over four times the recommended amount. His maximum daily consumption was 49.8 units. He had only 12.5 alcohol free days out of 87.5 days on which he was able to drink.

Conclusions James Bond’s level of alcohol intake puts him at high risk of multiple alcohol related diseases and an early death. The level of functioning as displayed in the books is inconsistent with the physical, mental, and indeed sexual functioning expected from someone drinking this much alcohol. We advise an immediate referral for further assessment and treatment, a reduction in alcohol consumption to safe levels, and suspect that the famous catchphrase “shaken, not stirred” could be because of alcohol induced tremor affecting his hands.”

viii. A couple of other non-serious links which I found hilarious:
1) The Prof(essor) or Hobo quiz (via SSC).
2) Today’s SMBC. I’ll try to remember the words in the votey in the highly unlikely case I’ll ever have use for them – in my opinion it would be a real tragedy if one were to miss an opportunity to make a statement like that, given that it was at all suitable to the situation at hand..

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July 6, 2015 Posted by | Chess, Diabetes, Epidemiology, History, Immunology, Infectious disease, Khan Academy, Lectures, Medicine, Personal | Leave a comment

Stuff

Sorry for the infrequent updates. I realized blogging Wodehouse books takes more time than I’d imagined, so posting this sort of stuff is probably a better idea.

i. Dunkirk evacuation (wikipedia ‘good article’). Fascinating article, as are a few of the related ones which I’ve also been reading (e.g. Operation Ariel).

“On the first day of the evacuation, only 7,669 men were evacuated, but by the end of the eighth day, a total of 338,226 soldiers had been rescued by a hastily assembled fleet of over 800 boats. Many of the troops were able to embark from the harbour’s protective mole onto 39 British destroyers and other large ships, while others had to wade out from the beaches, waiting for hours in the shoulder-deep water. Some were ferried from the beaches to the larger ships by the famous little ships of Dunkirk, a flotilla of hundreds of merchant marine boats, fishing boats, pleasure craft, and lifeboats called into service for the emergency. The BEF lost 68,000 soldiers during the French campaign and had to abandon nearly all of their tanks, vehicles, and other equipment.”

One way to make sense of the scale of the operations here is to compare them with the naval activities on D-day four years later. The British evacuated more people from France during three consecutive days in 1940 (30th and 31st of May, and 1st of June) than the Allies (Americans and British combined) landed on D-day four years later, and the British evacuated roughly as many people on the 31st of May (68,014) as they landed by sea on D-day (75,215). Here’s a part of the story I did not know:

“Three British divisions and a host of logistic and labour troops were cut off to the south of the Somme by the German “race to the sea”. At the end of May, a further two divisions began moving to France with the hope of establishing a Second BEF. The majority of the 51st (Highland) Division was forced to surrender on 12 June, but almost 192,000 Allied personnel, 144,000 of them British, were evacuated through various French ports from 15–25 June under the codename Operation Ariel.[104] […] More than 100,000 evacuated French troops were quickly and efficiently shuttled to camps in various parts of southwestern England, where they were temporarily lodged before being repatriated.[106] British ships ferried French troops to Brest, Cherbourg, and other ports in Normandy and Brittany, although only about half of the repatriated troops were deployed against the Germans before the surrender of France. For many French soldiers, the Dunkirk evacuation represented only a few weeks’ delay before being killed or captured by the German army after their return to France.[107]

ii. A pretty awesome display by the current world chess champion:

If you feel the same way I do about Maurice Ashley, you’ll probably want to skip the first few minutes of this video. Don’t miss the games, though – this is great stuff. Do keep in mind when watching this video that the clock is a really important part of this event; other players in the past have played a lot more people at the same time while blindfolded than Carlsen does here – “Although not a full-time chess professional [Najdorf] was one of the world’s leading chess players in the 1950s and 1960s and he excelled in playing blindfold chess: he broke the world record twice, by playing blindfold 40 games in Rosario, 1943,[8] and 45 in São Paulo, 1947, becoming the world blindfold chess champion” (link) – but a game clock changes things a lot. A few comments and discussion here.
In very slightly related news, I recently got in my first win against a grandmaster in a bullet game on the ICC.

iii. Gastric-brooding frog.

Rheobatrachus_silus

“The genus was unique because it contained the only two known frog species that incubated the prejuvenile stages of their offspring in the stomach of the mother.[3] […] What makes these frogs unique among all frog species is their form of parental care. Following external fertilization by the male, the female would take the eggs or embryos into her mouth and swallow them.[19] […] Eggs found in females measured up to 5.1 mm in diameter and had large yolk supplies. These large supplies are common among species that live entirely off yolk during their development. Most female frogs had around 40 ripe eggs, almost double that of the number of juveniles ever found in the stomach (21–26). This means one of two things, that the female fails to swallow all the eggs or the first few eggs to be swallowed are digested. […] During the period that the offspring were present in the stomach the frog would not eat. […] The birth process was widely spaced and may have occurred over a period of as long as a week. However, if disturbed the female may regurgitate all the young frogs in a single act of propulsive vomiting.”

Fascinating creatures.. Unfortunately they’re no longer around (they’re classified as extinct).

iv. I’m sort of conflicted about what to think about this:

“Epidemiological studies show that patients with type-2-diabetes (T2DM) and individuals with a diabetes-independent elevation in blood glucose have an increased risk for developing dementia, specifically dementia due to Alzheimer’s disease (AD). These observations suggest that abnormal glucose metabolism likely plays a role in some aspects of AD pathogenesis, leading us to investigate the link between aberrant glucose metabolism, T2DM, and AD in murine models. […] Recent epidemiological studies demonstrate that individuals with type-2 diabetes (T2DM) are 2–4 times more likely to develop AD (35), individuals with elevated blood glucose levels are at an increased risk to develop dementia (5), and those with elevated blood glucose levels have a more rapid conversion from mild cognitive impairment (MCI) to AD (6), suggesting that disrupted glucose homeostasis could play a […] causal role in AD pathogenesis. Although several prominent features of T2DM, including increased insulin resistance and decreased insulin production, are at the forefront of AD research (710), questions regarding the effects of elevated blood glucose independent of insulin resistance on AD pathology remain largely unexplored. In order to investigate the potential role of glucose metabolism in AD, we combined glucose clamps and in vivo microdialysis as a method to measure changes in brain metabolites in awake, freely moving mice during a hyperglycemic challenge. Our findings suggest that acute hyperglycemia raises interstitial fluid (ISF) Aβ levels by altering neuronal activity, which increases Aβ production. […] Since extracellular Aβ, and subsequently tau, aggregate in a concentration-dependent manner during the preclinical period of AD while individuals are cognitively normal (27), our findings suggest that repeated episodes of transient hyperglycemia, such as those found in T2DM, could both initiate and accelerate plaque accumulation. Thus, the correlation between hyperglycemia and increased ISF Aβ provides one potential explanation for the increased risk of AD and dementia in T2DM patients or individuals with elevated blood glucose levels. In addition, our work suggests that KATP channels within the hippocampus act as metabolic sensors and couple alterations in glucose concentrations with changes in electrical activity and extracellular Aβ levels. Not only does this offer one mechanistic explanation for the epidemiological link between T2DM and AD, but it also provides a potential therapeutic target for AD. Given that FDA-approved drugs already exist for the modulation of KATP channels and previous work demonstrates the benefits of sulfonylureas for treating animal models of AD (26), the identification of these channels as a link between hyperglycemia and AD pathology creates an avenue for translational research in AD.”

Why am I conflicted? Well, on the one hand it’s nice to know that they’re making progress in terms of figuring out why people get Alzheimer’s and potential therapeutic targets are being identified. On the other hand this – “our findings suggest that repeated episodes of transient hyperglycemia […] could both initiate and accelerate plaque accumulation” – is bad news if you’re a type 1 diabetic (I’d much rather have them identify risk factors to which I’m not exposed).

v. I recently noticed that Khan Academy has put up some videos about diabetes. From the few ones I’ve had a look at they don’t seem to contain much stuff I don’t already know so I’m not sure I’ll explore this playlist in any more detail, but I figured I might as well share a few of the videos here; the first one is about the pathophysiology of type 1 diabetes and the second one’s about diabetic nephropathy (kidney disease):

vi. On Being the Right Size, by J. B. S. Haldane. A neat little text. A few quotes:

“To the mouse and any smaller animal [gravity] presents practically no dangers. You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom, it gets a slight shock and walks away, provided that the ground is fairly soft. A rat is killed, a man is broken, a horse splashes. For the resistance presented to movement by the air is proportional to the surface of the moving object. Divide an animal’s length, breadth, and height each by ten; its weight is reduced to a thousandth, but its surface only to a hundredth. So the resistance to falling in the case of the small animal is relatively ten times greater than the driving force.

An insect, therefore, is not afraid of gravity; it can fall without danger, and can cling to the ceiling with remarkably little trouble. It can go in for elegant and fantastic forms of support like that of the daddy-longlegs. But there is a force which is as formidable to an insect as gravitation to a mammal. This is surface tension. A man coming out of a bath carries with him a film of water of about one-fiftieth of an inch in thickness. This weighs roughly a pound. A wet mouse has to carry about its own weight of water. A wet fly has to lift many times its own weight and, as everyone knows, a fly once wetted by water or any other liquid is in a very serious position indeed. An insect going for a drink is in as great danger as a man leaning out over a precipice in search of food. If it once falls into the grip of the surface tension of the water—that is to say, gets wet—it is likely to remain so until it drowns. A few insects, such as water-beetles, contrive to be unwettable; the majority keep well away from their drink by means of a long proboscis. […]

It is an elementary principle of aeronautics that the minimum speed needed to keep an aeroplane of a given shape in the air varies as the square root of its length. If its linear dimensions are increased four times, it must fly twice as fast. Now the power needed for the minimum speed increases more rapidly than the weight of the machine. So the larger aeroplane, which weighs sixty-four times as much as the smaller, needs one hundred and twenty-eight times its horsepower to keep up. Applying the same principle to the birds, we find that the limit to their size is soon reached. An angel whose muscles developed no more power weight for weight than those of an eagle or a pigeon would require a breast projecting for about four feet to house the muscles engaged in working its wings, while to economize in weight, its legs would have to be reduced to mere stilts. Actually a large bird such as an eagle or kite does not keep in the air mainly by moving its wings. It is generally to be seen soaring, that is to say balanced on a rising column of air. And even soaring becomes more and more difficult with increasing size. Were this not the case eagles might be as large as tigers and as formidable to man as hostile aeroplanes.

But it is time that we pass to some of the advantages of size. One of the most obvious is that it enables one to keep warm. All warmblooded animals at rest lose the same amount of heat from a unit area of skin, for which purpose they need a food-supply proportional to their surface and not to their weight. Five thousand mice weigh as much as a man. Their combined surface and food or oxygen consumption are about seventeen times a man’s. In fact a mouse eats about one quarter its own weight of food every day, which is mainly used in keeping it warm. For the same reason small animals cannot live in cold countries. In the arctic regions there are no reptiles or amphibians, and no small mammals. The smallest mammal in Spitzbergen is the fox. The small birds fly away in winter, while the insects die, though their eggs can survive six months or more of frost. The most successful mammals are bears, seals, and walruses.” [I think he’s a bit too categorical in his statements here and this topic is more contested today than it probably was when he wrote his text – see wikipedia’s coverage of Bergmann’s rule].

May 26, 2015 Posted by | Biology, Chess, Diabetes, Epidemiology, History, Khan Academy, Lectures, Medicine, Nephrology, Neurology, Wikipedia, Zoology | Leave a comment

Open Thread

Some random observations and some links:

i. I’ve written about diabetic hypoglycemia before – I even blogged a book on the topic just a few weeks ago. So I’ll keep this short. Here’s the key observation from the post to which I link: “Hypoglycemia causes functional brain failure that is corrected in the vast majority of instances after the plasma glucose concentration is raised”.

Functional brain failure is pretty much what it sounds like – the brain stops working. The point I want to make here is that hypoglycemia can strike pretty much at any point in time, including when I’m doing stuff like blogging or commenting. I sometimes develop hypoglycemia while deeply engrossed in some intellectual activity, like reading, writing or chess, in part because in those situations I have a tendency to forget to listen to my body’s signals – perhaps I forget to eat because this stuff is really much more interesting than food, perhaps I don’t really care that I should probably take a blood test now because I’d really much rather just finish this book chapter/chess game/blogpost/whatever. That happens. When it happens while I’m blogging, what comes out the other end may look funny. I occasionally write stuff that’s incoherent and stupid. Sometimes the explanation is simple: I’m an idiot. Sometimes other things play a role as well.

This is a variable you cannot observe, but which I have a lot of information about. It’s a variable I’d like readers of this blog to at least be aware of.

ii. Maxwell wrote this post, which you should consider reading. I won’t pretend to have good reasons/justifications for disliking people I conceive of as arrogant, but I do want to note that I do this and always have. Arrogance is a trait I dislike immensely.

iii. Over the last few days I’ve been reading Okasha’s great book Evolution and the Levels of Selection (I’ve almost finished it and I expect to blog it tomorrow) – so of course when Zach Weiner came up with this joke yesterday, I laughed. Loudly:

 

3444

(Click to view full size. The comic of course has almost nothing to do with the content of the book, but I’ll take any excuse I can get for blogging that comic…)

iv. The Feynman Lectures on Physics. Available to you, online, free of charge. Stuff like this sometimes makes me think we live in a very nice world at this point.

But then I read posts/watch videos like this one and I’m reminded that things are, complicated.

v. A few Khan Academy lectures:

August 8, 2014 Posted by | Genetics, History, Khan Academy, Lectures, Medicine, Personal, Physics | 9 Comments

Open Thread

A little random stuff from the web:

i.
1914 alt(link)

I felt pretty much that way after watching the video below and skimming parts of Terence Tao’s related blogpost.

I did a little work on infinite series and their convergence properties in a previous course in micro – enough to know that this stuff sometimes makes no sense at all – but I do not think I have ever seen this one before. Incidentally I should point out that if you ever get the impression that you have a tendency to overestimate your own intellectual abilities and you would like an easy way to keep reminding yourself that you’re not actually that smart, making Tao’s blog your starting page for a couple of weeks should do the trick…

ii. A couple of Khan Academy videos (just to remind you guys that the site is still around and still has a lot of videos you may be interested in watching at some point):

iii. A few interesting wikipedia links from the bookmarks (I can’t be bothered to write a ‘wikipedia links of interest post’):
Empire of Japan.
Juan Perón.
Operation Keelhaul.
Project MKUltra.
List of animals with fraudulent diplomas.

iv. After the end of the last chess tournament I participated in I got curious as to how strong the opponents I’m regularly playing against on playchess actually are, so I decided to for a while semi-systematically look up the ratings of the players I play against to get an idea how well I actually do. I got curious to a significant degree because despite a rather horrible end of the aforementioned tournament (½ out of 4 in the last four games), I still performed at ~1900 FIDE, which is far higher than the playing strength I had assumed based on my online games/rating. There may be multiple explanations for this, for one thing ‘over-the-board chess is different’. But another aspect may play a role as well: What I realized when I started ‘checking out’ my opponents was that a lot of strong players have online ratings not that different from my own (I defeated all these players in online games during the last month or so). Of course lots of opponents didn’t have fide ratings, and lots of players don’t add their true names to their profiles, but this little exercise did make me realize that I may not actually be doing that badly on the site.

I recently found out how to share games I’ve played on playchess, making the game sharing process significantly easier than it used to be. I may share more games in the future than I have in the past. Here are two games I played in January: 1, 2. On a related matter, here’s one reason why I’ll probably never become an IM. Despite the fact that I’m most of the time on the top 100 tactics list on playchess, I feel pretty confident I’ll never find a mate like that in one minute.

v. Am I the only one thinking this is way too much work to be worth the effort? Also: 88 dates? A mathematician like him should be familiar with the literature on optimal stopping rules (see e.g. this), and from my reading of the article it doesn’t seem as if he even considered implemented a stopping rule.

January 30, 2014 Posted by | Chess, History, Khan Academy, Lectures, Mathematics, Medicine, Open Thread | Leave a comment

Tuberculosis

Khan Academy has, in collaboration with Stanford School of Medicine, made 15 videos about the disease (so far) with a total duration of two hours and 37 minutes – you can watch all of them here. There’s some overlap here and there, different videos covering similar stuff, and a lot of details are left out. But this is still good stuff and the videos were an enjoyable part of my day yesterday. I know I’ve covered this disease before, but given how many people have been exposed and how important it was in the past (roughly one hundred years ago one sixth of all French deaths were due to this disease), this is arguably a disease you should at least have some knowledge about. Some samples from the playlist below:

Note that the spelling is off in that video; it’s Ghon focus and Ghon’s complex, not Gohn -ll- …

A quote from the last video above: “DOT – Directly Observed Therapy – is very important.”

There are theoretical reasons why DOT may be useful/efficient, as mentioned in the video. And I’ve seen it argued elsewhere that “treating tuberculosis with the DOTS strategy is highly cost-effective” [DOTS means “directly observed therapy, short course” – which is a specific type of DOT therapy; “a comprehensive tuberculosis management programme that focuses on low-income countries.” (see the Cochrane link for more)]. But I’m also aware that there are reasons to be skeptical as well:

Authors’ conclusions

The results of randomized controlled trials conducted in low-, middle-, and high-income countries provide no assurance that DOT compared with self administration of treatment has any quantitatively important effect on cure or treatment completion in people receiving treatment for tuberculosis.

PLAIN LANGUAGE SUMMARY

Directly observing people taking their tuberculosis drugs did not improve the cure rate compared with people without direct monitoring of treatment

Tuberculosis is a very serious health problem with two million people dying each year, mostly in low-income countries. Effective drugs for tuberculosis have been available since the 1940s, but the problem still abounds. People with tuberculosis need to take the drugs for at least six months, but many do not complete their course of treatment. For this reason, services for people with tuberculosis often use different approaches to encourage people to complete their course of treatment. This review found no evidence that direct observation by health workers, family members, or community members of people taking their medication showed better cure rates that [sic] people having self administered treatment. The intervention is expensive to implement, and there appears to be no sound reason to advocate its routine use until we better understand the situations in which it may be beneficial.”

July 11, 2013 Posted by | Infectious disease, Khan Academy, Lectures, Medicine, Microbiology, Pharmacology | Leave a comment

Khan Academy videos of interest

The first five are from the blood pressure control playlist here, the last one is from the applied math playlist. Steven Farmer dealt with related themes in his pharmacology lectures, but that was from a somewhat different angle. I deliberately omitted the kidney review video in the playlist below because I figured I’ve already covered that stuff here on the blog before. I was surprised to see Rishi do that review in the blood pressure control playlist because I figured a very good video on this topic was already available elsewhere on the site; I didn’t remember that it was Sal who did the first one, and I guess that as the site grows and some branching out takes place it makes sense that even the ‘lecturers’ may occasionally lose track of what other lecturers covered elsewhere on the site. Anyway, there’s no harm done in having two videos on this stuff and overall I’d say there’s a lot to be said for the current structure, with reasonably self-contained units – but enough about that, here are the videos:

ii.

iii.

iv.

v.

vi.

July 1, 2013 Posted by | Biology, Khan Academy, Lectures, Mathematics, Medicine, Nephrology | Leave a comment

Stuff

If you have any alternatives, especially ones which involve not-unpleasant interaction with other people, you should not follow these links or watch this stuff. Go interact with other people instead. Have fun, (try to) enjoy life. If you enjoy this kind of stuff, you’re likely doing things wrong and you’ll probably end up unhappy.

Tet offensive.

Arrest and assassination of Ngo Dinh Diem.

Genetically Modified Crops and Food Security.

War of 1812.

Tichborne case.

Geoguessr. It’s quite fun. My best score so far is 13165 (but who cares?).

June 9, 2013 Posted by | History, Immunology, Infectious disease, Khan Academy, Lectures, Medicine, Pharmacology, Physics, Random stuff, Wikipedia | Leave a comment

Khan Academy videos of interest

I should point out that a lot of good stuff has been added to the world history category since last I visited that part of the site – especially stuff about World War 1.

Some videos from the site:

i.

Some related numbers from wikipedia (Khan also briefly covers this aspect in another video):

“The Serbian Army declined severely towards the end of the war, falling from about 420,000[2] at its peak to about 100,000 at the moment of liberation. The Kingdom of Serbia lost 1,100,000 inhabitants during the war (both army and civilian losses), which represented over 27% of its overall population and 60% of its male population.[5][6] According to the Yugoslav government in 1924: Serbia lost 265,164 soldiers, or 25% of all mobilized people. By comparison, France lost 16.8%, Germany 15.4%, Russia 11.5%, and Italy 10.3%.”

There are huge error bars around these numbers, but that World War 1 was ‘a bloody affair’ for Serbia probably doesn’t even begin to cover it…

ii.

I’ve put the rest below the fold.

Continue reading

May 30, 2013 Posted by | History, Khan Academy, Mathematics, Wikipedia | Leave a comment

Stuff

I have a paper deadline approaching, so I’ll be unlikely to blog much more this week. Below some links and stuff of interest:

i. Plos One: A Survey on Data Reproducibility in Cancer Research Provides Insights into Our Limited Ability to Translate Findings from the Laboratory to the Clinic.

“we surveyed the faculty and trainees at MD Anderson Cancer Center using an anonymous computerized questionnaire; we sought to ascertain the frequency and potential causes of non-reproducible data. We found that ~50% of respondents had experienced at least one episode of the inability to reproduce published data; many who pursued this issue with the original authors were never able to identify the reason for the lack of reproducibility; some were even met with a less than “collegial” interaction. […] These results suggest that the problem of data reproducibility is real. Biomedical science needs to establish processes to decrease the problem and adjudicate discrepancies in findings when they are discovered.”

ii. The development in the number of people killed in traffic accidents in Denmark over the last decade (link):

Traffic accidents
For people who don’t understand Danish: The x-axis displays the years, the y-axis displays deaths – I dislike it when people manipulate the y-axis (…it should start at 0, not 200…), but this decline is real; the number of Danes killed in traffic accidents has more than halved over the last decade (463 deaths in 2002; 220 deaths in 2011). The number of people sustaining traffic-related injuries dropped from 9254 in 2002 to 4259 in 2011. There’s a direct link to the data set at the link provided above if you want to know more.

iii. Gender identity and relative income within households, by Bertrand, Kamenica & Pan.

“We examine causes and consequences of relative income within households. We establish that gender identity – in particular, an aversion to the wife earning more than the husband – impacts marriage formation, the wife’s labor force participation, the wife’s income conditional on working, marriage satisfaction, likelihood of divorce, and the division of home production. The distribution of the share of household income earned by the wife exhibits a sharp cliff at 0.5, which suggests that a couple is less willing to match if her income exceeds his. Within marriage markets, when a randomly chosen woman becomes more likely to earn more than a randomly chosen man, marriage rates decline. Within couples, if the wife’s potential income (based on her demographics) is likely to exceed the husband’s, the wife is less likely to be in the labor force and earns less than her potential if she does work. Couples where the wife earns more than the husband are less satisfied with their marriage and are more likely to divorce. Finally, based on time use surveys, the gender gap in non-market work is larger if the wife earns more than the husband.” […]

“In our preferred specification […] we find that if the wife earns more than the husband, spouses are 7 percentage points (15%) less likely to report that their marriage is very happy, 8 percentage points (32%) more likely to report marital troubles in the past year, and 6 percentage points (46%) more likely to have discussed separating in the past year.”

These are not trivial effects…

iv. Some Khan Academy videos of interest:

v. The Age Distribution of Missing Women in India.

“Relative to developed countries, there are far fewer women than men in India. Estimates suggest that among the stock of women who could potentially be alive today, over 25 million are “missing”. Sex selection at birth and the mistreatment of young girls are widely regarded as key explanations. We provide a decomposition of missing women by age across the states. While we do not dispute the existence of severe gender bias at young ages, our computations yield some striking findings. First, the vast majority of missing women in India are of adult age. Second, there is significant variation in the distribution of missing women by age across different states. Missing girls at birth are most pervasive in some north-western states, but excess female mortality at older ages is relatively low. In contrast, some north-eastern states have the highest excess female mortality in adulthood but the lowest number of missing women at birth. The state-wise variation in the distribution of missing women across the age groups makes it very difficult to draw simple conclusions to explain the missing women phenomenon in India.”

A table from the paper:

Anderson et al

“We estimate that a total of more than two million women in India are missing in a given year. Our age decomposition of this total yields some striking findings. First, the majority of missing women, in India die in adulthood. Our estimates demonstrate that roughly 12% of missing women are found at birth, 25% die in childhood, 18% at the reproductive ages, and 45% die at older ages. […] There are just two states in which the majority of missing women are either never born or die in childhood (i e, [sic] before age 15), and these are Haryana and Rajasthan. Moreover, the missing women in these three states add up to well under 15% of the total missing women in India.

For all other states, the majority of missing women die in adulthood. […]

Because there is so much state-wise variation in the distribution of missing women across the age groups, it is difficult to provide a clear explanation for missing women in India. The traditional explanation for missing women, a strong preference for the birth of a son, is most likely driving a significant proportion of missing women in the two states of Punjab and Haryana where the biased sex ratios at birth are undeniable. However, the explanation for excess female deaths after birth is far from clear.”

May 22, 2013 Posted by | Cancer/oncology, Chemistry, Data, Demographics, Economics, Khan Academy, marriage, Medicine, Papers | Leave a comment

Stuff

i. Econometric methods for causal evaluation of education policies and practices: a non-technical guide. This one is ‘work-related’; in one of my courses I’m writing a paper and this working paper is one (of many) of the sources I’m planning on using. Most of the papers I work with are unfortunately not freely available online, which is part of why I haven’t linked to them here on the blog.

I should note that there are no equations in this paper, so you should focus on the words ‘a non-technical guide’ rather than the words ‘econometric methods’ in the title – I think this is a very readable paper for the non-expert as well. I should of course also note that I have worked with most of these methods in a lot more detail, and that without the math it’s very hard to understand the details and really know what’s going on e.g. when applying such methods – or related methods such as IV methods on panel data, a topic which was covered in another class just a few weeks ago but which is not covered in this paper.

This is a place to start if you want to know something about applied econometric methods, particularly if you want to know how they’re used in the field of educational economics, and especially if you don’t have a strong background in stats or math. It should be noted that some of the methods covered see wide-spread use in other areas of economics as well; IV is widely used, and the difference-in-differences estimator have seen a lot of applications in health economics.

ii. Regulating the Way to Obesity: Unintended Consequences of Limiting Sugary Drink Sizes. The law of unintended consequences strikes again.

You could argue with some of the assumptions made here (e.g. that prices (/oz) remain constant) but I’m not sure the findings are that sensitive to that assumption, and without an explicit model of the pricing mechanism at work it’s mostly guesswork anyway.

iii. A discussion about the neurobiology of memory. Razib Khan posted a short part of the video recently, so I decided to watch it today. A few relevant wikipedia links: Memory, Dead reckoning, Hebbian theory, Caenorhabditis elegans. I’m skeptical, but I agree with one commenter who put it this way: “I know darn well I’m too ignorant to decide whether Randy is possibly right, or almost certainly wrong — yet I found this interesting all the way through.” I also agree with another commenter who mentioned that it’d have been useful for Gallistel to go into details about the differences between short term and long term memory and how these differences relate to the problem at hand.

iv. Plos-One: Low Levels of Empathic Concern Predict Utilitarian Moral Judgment.

“An extensive body of prior research indicates an association between emotion and moral judgment. In the present study, we characterized the predictive power of specific aspects of emotional processing (e.g., empathic concern versus personal distress) for different kinds of moral responders (e.g., utilitarian versus non-utilitarian). Across three large independent participant samples, using three distinct pairs of moral scenarios, we observed a highly specific and consistent pattern of effects. First, moral judgment was uniquely associated with a measure of empathy but unrelated to any of the demographic or cultural variables tested, including age, gender, education, as well as differences in “moral knowledge” and religiosity. Second, within the complex domain of empathy, utilitarian judgment was consistently predicted only by empathic concern, an emotional component of empathic responding. In particular, participants who consistently delivered utilitarian responses for both personal and impersonal dilemmas showed significantly reduced empathic concern, relative to participants who delivered non-utilitarian responses for one or both dilemmas. By contrast, participants who consistently delivered non-utilitarian responses on both dilemmas did not score especially high on empathic concern or any other aspect of empathic responding.”

In case you were wondering, the difference hasn’t got anything to do with a difference in the ability to ‘see things from the other guy’s point of view’: “the current study demonstrates that utilitarian responders may be as capable at perspective taking as non-utilitarian responders. As such, utilitarian moral judgment appears to be specifically associated with a diminished affective reactivity to the emotions of others (empathic concern) that is independent of one’s ability for perspective taking”.

On a small sidenote, I’m not really sure I get the authors at all – one of the questions they ask in the paper’s last part is whether ‘utilitarians are simply antisocial?’ This is such a stupid way to frame this I don’t even know how to begin to respond; I mean, utilitarians make better decisions that save more lives, and that’s consistent with them being antisocial? I should think the ‘social’ thing to do would be to save as many lives as possible. Dead people aren’t very social, and when your actions cause more people to die they also decrease the scope for future social interaction.

v. Lastly, some Khan Academy videos:

(Relevant links: Compliance, Preload).

(This one may be very hard to understand if you haven’t covered this stuff before, but I figured I might as well post it here. If you don’t know e.g. what myosin and actin is you probably won’t get much out of this video. If you don’t watch it, this part of what’s covered is probably the most important part to take away from it.)

It’s been a long time since I checked out the Brit Cruise information theory playlist, and I was happy to learn that he’s updated it and added some more stuff. I like the way he combines historical stuff with a ‘how does it actually work, and how did people realize that’s how it works’ approach – learning how people figured out stuff is to me sometimes just as fascinating as learning what they figured out:

(Relevant wikipedia links: Leyden jar, Electrostatic generator, Semaphore line. Cruise’ play with the cat and the amber may look funny, but there’s a point to it: “The Greek word for amber is ηλεκτρον (“elektron”) and is the origin of the word “electricity”.” – from the first link).

(Relevant wikipedia links: Galvanometer, Morse code)

April 14, 2013 Posted by | Cardiology, Computer science, Cryptography, Econometrics, Khan Academy, Medicine, Neurology, Papers, Physics, Random stuff, Statistics | Leave a comment

Stuff

i. I had a doctor’s appointment today and got the results of my bloodwork back. My Hba1c was 48, or 6.5%. This is the lowest it’s been for as long as I can remember. I have had some trouble with hypoglycemic episodes now and then, but not significantly more than usual and I’ve had no major episodes. I believe the lowered Hba1c is probably mostly a result of lowered nocturnal blood glucose values. These have however at some points been uncomfortably low, so I’m not sure 6,5 is a realistic long-term goal and because of those uncomfortably low values I have made adjustments along the way which probably means that the Hba1c may be a bit higher next time if other things stay pretty much the same (which I know they won’t; for instance I’m planning on significantly increasing my running over the next four months). But even so I was very happy about this result, as I choose to believe that it means I’ll actually be able to obtain <7.0% results in the future without major adverse events if I’m careful and vigilant.

This recent post goes into more detail about the hypoglycemia risk and what it’s about. This Danish post has some data on the distribution of Hba1c results among Danish diabetics – the relevant figure is this one (with 6.5%, I’m in the 10% fractile).

ii. I’m now ‘officially’ a researcher. I have just become a member of Statistics Denmark’s research programme (-forskerordning), which means that I’ve obtained access to a specific data set which I’ll do work on during the next year. Danish registers contain a lot of good information compared to the registers of most other countries, so I may actually be able to look at stuff that a lot of researchers elsewhere are simply not able to analyze due to data issues – which is exciting. Unfortunately I’ll not be comfortable blogging anything about this stuff, as there are a huge number of restrictions on data access/sharing etc. – but I believe it’ll be interesting to work with this stuff and I’m looking forward to it.

iii. A couple of Khan Academy videos:

iv. PlosOne: Sex Differences in Mathematics and Reading Achievement Are Inversely Related: Within- and Across-Nation Assessment of 10 Years of PISA Data.

Abstract: “We analyzed one decade of data collected by the Programme for International Student Assessment (PISA), including the mathematics and reading performance of nearly 1.5 million 15 year olds in 75 countries. Across nations, boys scored higher than girls in mathematics, but lower than girls in reading. The sex difference in reading was three times as large as in mathematics. There was considerable variation in the extent of the sex differences between nations. There are countries without a sex difference in mathematics performance, and in some countries girls scored higher than boys. Boys scored lower in reading in all nations in all four PISA assessments (2000, 2003, 2006, 2009). Contrary to several previous studies, we found no evidence that the sex differences were related to nations’ gender equality indicators. Further, paradoxically, sex differences in mathematics were consistently and strongly inversely correlated with sex differences in reading: Countries with a smaller sex difference in mathematics had a larger sex difference in reading and vice versa. We demonstrate that this was not merely a between-nation, but also a within-nation effect. This effect is related to relative changes in these sex differences across the performance continuum: We did not find a sex difference in mathematics among the lowest performing students, but this is where the sex difference in reading was largest. In contrast, the sex difference in mathematics was largest among the higher performing students, and this is where the sex difference in reading was smallest. The implication is that if policy makers decide that changes in these sex differences are desired, different approaches will be needed to achieve this for reading and mathematics. Interventions that focus on high-achieving girls in mathematics and on low achieving boys in reading are likely to yield the strongest educational benefits.”

v. Genomic responses in mouse models poorly mimic human inflammatory diseases.

Abstract: “A cornerstone of modern biomedical research is the use of mouse models to explore basic pathophysiological mechanisms, evaluate new therapeutic approaches, and make go or no-go decisions to carry new drug candidates forward into clinical trials. Systematic studies evaluating how well murine models mimic human inflammatory diseases are non-existent. Here, we show that, although acute inflammatory stresses from different etiologies result in highly similar genomic responses in humans, the responses in corresponding mouse models correlate poorly with the human conditions and also, one another. Among genes changed significantly in humans, the murine orthologs are close to random in matching their human counterparts (e.g.,R^2 between 0.0 and 0.1). In addition to improvements in the current animal model systems, our study supports higher priority for translational medical research to focus on the more complex human conditions rather than relying on mouse models to study human inflammatory diseases.”

vi. Married men at the age of 40 can expect to live on average 7.1 years longer than unmarried men at the age of 40, and 6.6 years longer than divorced men at the age of 40. For women the life expectancy difference between the married and unmarried group is 4.8 years, and the difference between married women and divorced women is 4.3 years. The excess mortality for unmarried men in their forties (compared with married males) is around 250%, and for men in their fifties it’s still above 200%.

The data reported above is from a new publication by Statistics Denmark which you can read here. Here’s a related publication. Here is a recent publication on the education levels of Danish emigrants. All three publications are unfortunately in Danish.

vii. Nasa – The Tyranny of the Rocket Equation. This part was surprising to me, because I’d never really thought about this:

“If the radius of our planet were larger, there could be a point at which an Earth escaping rocket could not be built. Let us assume that building a rocket at 96% propellant (4% rocket), currently the limit for just the Shuttle External Tank, is the practical limit for launch vehicle engineering. Let us also choose hydrogen-oxygen, the most energetic chemical propellant known and currently capable of use in a human rated rocket engine. By plugging these numbers into the rocket equation, we can transform the calculated escape velocity into its equivalent planetary radius. That radius would be about 9680 kilometers (Earth is 6670 km). If our planet was 50% larger in diameter, we would not be able to venture into space, at least using rockets for transport.”

viii. I’m very surprised they did not already know this.

April 3, 2013 Posted by | Data, Demographics, Diabetes, Genetics, Khan Academy, Mathematics, Papers, Personal, Physics | Leave a comment

Khan Academy videos of interest

I assume that not all of the five videos below are equally easy to understand for people who’ve not watched the previous ones in the various relevant playlists, but this is the stuff I’ve been watching lately and you should know where to look by now if something isn’t perfectly clear. I incidentally covered some relevant background material previously on the blog – if concepts from chemistry like ‘oxidation states’ are a bit far away, a couple of the videos in that post may be helpful.

I stopped caring much when I reached the 1 million mark (until they introduced the Kepler badge – then I started caring a little again until I’d gotten that one), but I noticed today that I’m at this point almost at the 1,5 million energy points mark (1.487.776). I’ve watched approximately 400 videos at the site by now.

Here’s a semi-related link with some good news: Khan Academy Launches First State-Wide Pilot In Idaho.

March 7, 2013 Posted by | Biology, Botany, Chemistry, Khan Academy, Lectures | 2 Comments

Khan Academy videos of interest

Took me a minute to solve without hints. I had to scribble a few numbers down (like Khan does in the video), but you should be able to handle it without hints. (Actually I think some of the earlier brainteasers on the playlist are harder than this one and that some of the later ones are easier, but it’s a while since I saw the first ones.)


Much more here.

Naturally this is from the computer science section.

It’s been a while since I’ve last been to Khan Academy – it seems that these days they have an entire section about influenza.

February 10, 2013 Posted by | Cardiology, Computer science, Infectious disease, Khan Academy, Lectures, Mathematics, Medicine | Leave a comment

Khan Academy videos of interest

There are other ressources than Khan Academy out there, so I thought I’d start out with a few remarks related to those. I’m about to start a course on coursera which I signed up for a long time ago, but I’m actually reconsidering now because I may not be able to find the time. If you don’t know about the site, go have a look around. A friend of mine also linked to this collection of videos from MIT on Electricity and Magnetism – looks very interesting. Anyway, a few Khan Academy videos below:

Just how sensitive blood flow is to vessel radius is an aspect I’d never given much thought, even though this is not exactly the first time I’ve done work on fluid dynamics (there’s also a largish section on that at Khan Academy) or the cardiovascular system. For some reason this video really made that link much more obvious to me, and these dynamics make it easier in my mind to understand why even relatively small changes in blood vessel composition over time can actually impede blood flow quite significantly and turn out to have rather large physiological effects. Math far more often than not helps me to think more clearly about stuff.

Some other videos:

October 8, 2012 Posted by | Biology, Cardiology, Khan Academy, Medicine | Leave a comment

More Khan Academy stuff you should know about

It’s been a while since I’ve been to Khan Academy (actually getting the Kepler badge sort of killed my motivation for a while), but I revisited the site earlier today and I realized that they’ve launched a brand new computer science section which looks really neat. Intro video below:

August 27, 2012 Posted by | Computer science, Khan Academy | Leave a comment

Khaaan!

Here’s what the profile looks like now:

The topics are (still) all mathematics-related, and there are currently 345 individual skills in which one can obtain mastery. So having 300 below the belt means that I’ve pretty much cleaned out most major sections (each of the 19 challenge patches above basically required complete mastery of all exercises in the given topic).

I find it interesting that the incentive system of Khan Academy apparently seem to be so effective on me, considering how hard it is for me on a general level to do what I’d consider ‘real work’. I’m still not sure how much of it is the badge/achievements system and how much is other stuff; but I do know that when I study ‘in real life’, I get zero feedback on my performance or skill level for months. Feedback is basically what you get after you’ve sat your exams – twice a year or so. Sometimes there’s a bit more than that, but not much. If it’s possible and realistic to do this somehow (I know that some people argue that it is; by involving other people as well, putting money on the line etc.), it seems like it would be optimal for me to set up similar incentive systems for other areas of my life.

On the other hand, part of what makes Khan Academy’s system work so well on me is probably exactly that doing nothing any given day has zero consequenses for me; the punishment element/aspect is completely absent, so I always feel a (/false) sense of achievement after I’ve done work there. But if I had a third hand, I’d probably add to that that I’ve not actually spent all that much time at the site (compared to how much time is required to put in to get through a normal semester at a university). So I’m likely overestimating the relevant effect sizes.

Either way, the people at Khan Academy have done a lot of things – succesfully, I’d add – to make learning new stuff fun. If you haven’t already, you should make a profile and start learning. I’m willing to bet you don’t know everything that’s covered on the site.

May 12, 2012 Posted by | Khan Academy, Personal | Leave a comment

More ‘stuff’

i. (click images to view them in full size)

(link)

ii. Ed Yong has written a good piece about Kawaoka et al.’s study on bird flu mutations. I think you’ll learn more from Ed’s piece than from the actual study, but I wouldn’t know as I have only but very briefly skimmed the study.

iii. Ben Goldacre: Battling bad science. Ben Goldacre’s TED talk.

iv. A quote by Mencius Moldbug: “in many ways nonsense is a more effective organizing tool than the truth. Anyone can believe in the truth. To believe in nonsense is an unforgeable demonstration of loyalty. It serves as a political uniform. And if you have a uniform, you have an army.” I seem to recall having said something very much along the same lines quite a few times in the past. But it’s worth repeating. Direct link here, via lesswrong.

v. So, lately I’ve been reading Heather. I know I should have long finished the book by now, but I don’t seem to have been able to put in more than a few hours here and there lately, and it’s a very long book so I’m not quite done yet. It doesn’t help that I’m actually studying the book, instead of ‘just reading’ it; I don’t seem to be able to achieve much more than 20-25 pages/hour. I really like it though, and I hope to finish it later this week. Here’s a good quote from the concluding remarks of chapter 6, on Franks and Anglo-Saxons:

“there are many ways in which Frankish and Anglo-Saxon migration illustrate and develop the main themes of this book. Transport logistics […] and active fields of information decisively shaped both, but perhaps above all it is again the interaction of migration and patterns of development, and the huge role played by prevailing political structures, that jump out of the evidence. Frankish and Anglo-Saxon migration can be seen as mechanisms by which unequal patterns of development were renegotiated. Despite its own economic transformations during the Roman era, non-Roman western Europe lagged sufficiently far behind adjacent areas of the Empire for the latter’s wealth to exercise a strong pull. […] The main way for most outsiders to access any of this wealth […] was to raid it regularly for movables, apart from a relatively few who made it big in the Roman army. Throughout the Roman period, this greater wealth was protected by armies and fortifications. As lowland Britain and north-eastern Gaul fell out of central imperial control at different points in the fifth century, however, the restriction these imperial institutions had imposed upon the capacity of outside populations to seize control of capital assets was removed, and raiding, after a time lag, turned into predatory migration, aiming at the seizure of landed estates.
Unequal development was ultimately responsible, then, for both flows of migration. But both the Frankish and the Anglo-Saxon versions were effect, rather than cause, of central Roman collapse. They played a major role in dismantling such structures of local Roman provincial life as remained upon their arrival in northern Gaul and Britain, respectively, but in both cases it was the failure of the imperial centre’s capacity to maintain enough force on its fringes that exposed these provincial Roman societies to immigrant attention.”

vi. Via Big Think, a few graphs and a few stats:

“Did you know that almost 90% of the world’s population lives in the northern hemisphere? And that half of all Earthlings [1] reside north of 27°N? Or that the average human lives at 24 degrees from the equator – either to its north or south?” (here’s a related post of mine)

vii. Romanization of Chinese.

viii. A Yale lecture – Demographic Transition in Europe; Fertility Decline:

ix. The Tragic Truth About India’s Caste System.

x. The people at 23andMe (the name should be familiar to people reading gnxp) have made some videos on ‘human prehistory’ and on ‘genetics 101’ which are now available at Khan Academy. I’ve posted the ones on human prehistory below, you can watch the genetics videos here.

If you’re interested in reading about the ‘Out of Africa’ hypothesis and related matters, Razib Khan has written about this subject a lot and so have a few others at Discovermagazine. Go here for a lot of links to reading material about this (the last half of the links or so are written by RK). You can also go the textbook route. But if you don’t have the time or you’re not curious enough to justify spending many hours reading about this stuff, do at least watch the videos – they’re really quite good. Here are the rest of them:

If nobody clicks the link to the biology section above where one can watch the Genetics 101 videos, I’ll probably blog those too at a later point in time. I know that there are a lot of links in this post, but you shouldn’t miss those either.

xi. Binary star.

xii. Transform fault.

May 3, 2012 Posted by | Anthropology, Astronomy, Books, Data, Demographics, Genetics, Geography, Geology, Khan Academy, Physics, Quotes/aphorisms, Random stuff, Wikipedia | Leave a comment

Random stuff from the net, links, wikipedia…

1. RAND: Living Well at the End of Life (via Razib Khan). Here’s a link to one of the sources, a book which deals with some of the same questions: Approaching Death: Improving Care at the End of Life. Looks interesting, don’t have time to read it at the moment.

2. Fatal familial insomnia. “Fatal familial insomnia (FFI) is a very rare autosomal dominant inherited prion disease of the brain. It is almost always caused by a mutation to the protein PrPC, but can also develop spontaneously in patients with a non-inherited mutation variant called sporadic Fatal Insomnia (sFI). FFI is an incurable disease, involving progressively worsening insomnia, which leads to hallucinations, delirium, and confusional states like that of dementia.[1] The average survival span for patients diagnosed with FFI after the onset of symptoms is 18 months.”

Sleep’s important.

3. False consensus effect.

“In psychology, the false consensus effect is a cognitive bias whereby a person tends to overestimate how much other people agree with him or her. There is a tendency for people to assume that their own opinions, beliefs, preferences, values and habits are ‘normal’ and that others also think the same way that they do.[1] This cognitive bias tends to lead to the perception of a consensus that does not exist, a ‘false consensus’. This false consensus is significant because it increases self-esteem. The need to be “normal” and fit in with other people is underlined by a desire to conform and be liked by others in a social environment.

Within the realm of personality psychology, the false consensus effect does not have significant effects. This is because the false consensus effect relies heavily on the social environment and how a person interprets this environment. Instead of looking at situational attributions, personality psychology evaluates a person with dispositional attributions, making the false consensus effect relatively irrelevant in that domain. Therefore, a person’s personality potentially could affect the degree that the person relies on false consensus effect, but not the existence of such a trait.

The false consensus effect is not necessarily restricted to cases where people believe that their values are shared by the majority. The false consensus effect is also evidenced when people overestimate the extent of their particular belief is correlated with the belief of others. Thus, fundamentalists do not necessarily believe that the majority of people share their views, but their estimates of the number of people who share their point of view will tend to exceed the actual number.

This bias is especially prevalent in group settings where one thinks the collective opinion of their own group matches that of the larger population. Since the members of a group reach a consensus and rarely encounter those who dispute it, they tend to believe that everybody thinks the same way.

Additionally, when confronted with evidence that a consensus does not exist, people often assume that those who do not agree with them are defective in some way.[2] There is no single cause for this cognitive bias; the availability heuristic and self-serving bias have been suggested as at least partial underlying factors.

The false consensus effect can be contrasted with pluralistic ignorance, an error in which people privately disapprove but publicly support what seems to be the majority view (regarding a norm or belief), when the majority in fact shares their (private) disapproval. While the false consensus effect leads people to wrongly believe that they agree with the majority (when the majority, in fact, openly disagrees with them), the pluralistic ignorance effect leads people to wrongly believe that they disagree with the majority (when the majority, in fact, covertly agrees with them).”

4. Malthus, An Essay on the Principle of Population. Salman Khan recently made a video on the subject, here’s wikipedia.

5. Marital Rape License (warning, tvtropes link).

“Only a few decades ago, it was legal for a man to rape his wife. Sweden was the first country to explicitly criminalize it in 1965, and it has only been illegal in all fifty US states since 1993. Fifty-three countries around the world still don’t consider it a crime.

In some old patriarchal systems, a woman belonged first to her father (or closest living male relative if the father was dead) and then to her husband. Once married — and in some systems she could be married off without her consent to some old man she despised or had never met — her husband had a legal and “moral” right to her body whether she liked it or not. It gets even creepier when the bride is underage.”

We tend to take a lot of stuff for granted. Another reason why you should read Nothing To Envy.

6. Schema (psychology)

“A schema (pl. schemata or schemas), in psychology and cognitive science, describes any of several concepts including:

*An organized pattern of thought or behavior.
*A structured cluster of pre-conceived ideas.
*A mental structure that represents some aspect of the world.
*A specific knowledge structure or cognitive representation of the self.
*A mental framework centering on a specific theme, that helps us to organize social information.
*Structures that organize our knowledge and assumptions about something and are used for interpreting and processing information.

A schema for oneself is called a “self schema”. Schemata for other people are called “person schemata”. Schemata for roles or occupations are called “role schemata”, and schemata for events or situations are called “event schemata” (or scripts).

Schemata influence our attention, as we are more likely to notice things that fit into our schema. If something contradicts our schema, it may be encoded or interpreted as an exception or as unique. Thus, schemata are prone to distortion. They influence what we look for in a situation. They have a tendency to remain unchanged, even in the face of contradictory information. We are inclined to place people who do not fit our schema in a “special” or “different” category, rather than to consider the possibility that our schema may be faulty. As a result of schemata, we might act in such a way that actually causes our expectations to come true.”

7. Koch Snowflake Fractal (a structure with infinite perimeter but a finite area). Couldn’t remember if I’ve already blogged this at one point, but no harm done in case I have:

January 3, 2012 Posted by | Books, Genetics, health care, Khan Academy, Mathematics, Psychology, Wikipedia | Leave a comment

Khan Academy videos of interest

(I know there’s been a lot of video posts recently, this is almost turning into a vlog, but…)

Some additional data: I’ve previously blogged a Danish version of the ‘health care spending as a percentage of GDP’ -graph, going back to ~ 1970. The title is in Danish but it really shouldn’t be much of a problem for non-Danish speaking readers to figure out what’s going on:

November 7, 2011 Posted by | Biology, Data, Economics, Health Economics, Khan Academy, Lectures, Medicine | Leave a comment

Random stuff

i. Perhaps most ‘imposter-syndrome’ sufferers are really imposters who do not suffer from imposter-syndrome. Convoluted? Well:

“Social psychologists have studied what they call the impostor phenomenon since at least the 1970s, when a pair of therapists at Georgia State University used the phrase to describe the internal experience of a group of high-achieving women who had a secret sense they were not as capable as others thought. Since then researchers have documented such fears in adults of all ages, as well as adolescents.

Their findings have veered well away from the original conception of impostorism as a reflection of an anxious personality or a cultural stereotype. Feelings of phoniness appear to alter people’s goals in unexpected ways and may also protect them against subconscious self-delusions.

Questionnaires measuring impostor fears ask people how much they agree with statements like these: “At times, I feel my success has been due to some kind of luck.” “I can give the impression that I’m more competent than I really am.” “If I’m to receive a promotion of some kind, I hesitate to tell others until it’s an accomplished fact.”

Researchers have found, as expected, that people who score highly on such scales tend to be less confident, more moody and rattled by performance anxieties than those who score lower. […]

In short, the researchers concluded, many self-styled impostors are phony phonies: they adopt self-deprecation as a social strategy, consciously or not, and are secretly more confident than they let on.

“Particularly when people think that they might not be able to live up to others’ views of them, they may maintain that they are not as good as other people think,” Dr. Mark Leary, the lead author, wrote in an e-mail message. “In this way, they lower others’ expectations — and get credit for being humble.”

In a study published in September, Rory O’Brien McElwee and Tricia Yurak of Rowan University in Glassboro, N.J., had 253 students take an exhaustive battery of tests assessing how people present themselves in public. They found that psychologically speaking, impostorism looked a lot more like a self-presentation strategy than a personality trait.”

My emphasis, and here’s the link. The interesting thing to me is why exceeding expectations for a given accomplishment level is status-enhancing compared to doing worse than expected. Anyway, this is one of the many ways that people who pretend to be humble brag – by downplaying expectations they increase the status level associated with any given accomplishment-level. Very few people would consider employing a strategy aimed at improving expectations-forming mechanisms to better match reality in the long run a status-enhancing move.

ii.

Calvin: “I say it’s a fallacy that kids need 12 years of school! Three months is plenty!”
Calvin: “Look at me. I’m smart! I don’t need 11½ more years of school! It’s a complete waste of my time!”
Hobbes: “How on Earth did you get all the way to the bus stop with both feet through one pant leg?”
Calvin: “I fell down a lot.”
Calvin: “…Why? What’s your point?”
Hobbes: “Nothing. I was just curious.”

Calvin: “Look at all these ants.”
Calvin: “They’re all running like mad, working tirelessly all day, never stopping, never resting.”
Calvin: “And for what? To build a tiny little hill of sand that could be wiped out at any moment! All their work could be for nothing, and yet they keep on building. They never give up!”
Hobbes: “I suppose there’s a lesson in that.”
Calvin: “Yeah … Ants are morons. Let’s see what’s on TV.”

Calvin: “Tigers don’t worry about much, do they?”
Hobbes: “Nope.”
Hobbes: “That’s one of the perks of being feral.”
Calvin: “I’m not having enough fun right now.”
Hobbes: “You’re not?”
Calvin: “I’m just having a little bit of fun. I should be having lots of fun.”
Calvin: “It’s Sunday. I’ve just got a few precious hours of freedom left before I have to go to school tomorrow.”
Calvin: “Between now and bedtime, I have to squeeze all the fun possible out of every minute! I don’t want to waste a second of liberty!”
Calvin: “Each moment I should be able to say, “I’m having the time of my life right now!'”
Calvin: “But here I am, and I’m not having the time of my life! Valuable minutes are disappearing forever, even as we speak! We’ve got to have more fun! C’mon!”
[Calvin and Hobbes start running away]
Hobbes: “I didn’t realize fun was so much work.”
Calvin: “Sure! When you’re serious about having fun, it’s not much fun at all.”

When I was a child, I sometimes felt like Calvin did in that last comic. I never do anymore. I guess it’s part of growing up. Reading a strip like this once you have is a good way to make you remember that here is something you’ve probably lost for ever. I have read a lot of Calvin and Hobbes over the last couple of days. I really love that comic but sometimes reading it really hurts. Some of it is a lot deeper than it lets on.

iii.

I tweeted this, but in case you missed it: Khan Academy have now added Art History to the list of subjects covered. 300 videos of it. I don’t know how many of my readers have an interest in that stuff (I don’t), but if you do – go knock yourself out! They write in the blogpost that: “we are incredibly excited to push the frontier on freely available content in the Arts and Humanities.” And I’m excited about that too. People really shold not be paying a lot of money for this kind of stuff. Maybe if it’s available for free online – and presented at a site including other stuff as well, such as mathematics, physics ect., more young people will start to realize that…

October 20, 2011 Posted by | Khan Academy, Psychology, Quotes/aphorisms, rambling nonsense, Random stuff | Leave a comment