knowledge sharing « Econstudentlog

Wikipedia articles of interest

i. British anti-invasion preparations of World War II. From the article:

“Any German invasion of Britain would have to involve the landing of troops and equipment somewhere on the coast, and the most vulnerable areas were the south and east coasts of England. Here, Emergency Coastal Batteries were constructed to protect ports and likely landing places. They were fitted with whatever guns were available, which mainly came from naval vessels scrapped since the end of the First World War. These included 6 inch (152 mm), 5.5 inch (140 mm), 4.7 inch (120 mm) and 4 inch (102 mm) guns. These had little ammunition, sometimes as few as ten rounds apiece. At Dover, two 14 inch (356 mm) guns known as Winnie and Pooh were employed.^[25] There were also a small number of land based torpedo launching sites.^[26]

Beaches were blocked with entanglements of barbed wire, usually in the form of three coils of concertina wire fixed by metal posts, or a simple fence of straight wires supported on waist-high posts.^[27] The wire would also demarcate extensive minefields, with both anti-tank and anti-personnel mines on and behind the beaches. On many of the more remote beaches this combination of wire and mines represented the full extent of the passive defences.

Portions of the Romney Marsh, which was the planned invasion site of Operation Sea Lion, were flooded^[28] and there were plans to flood more of the Marsh if the invasion were to materialise.^[29]

Piers, ideal for landing of troops, and situated in large numbers along the south coast of England, were disassembled, blocked or otherwise destroyed. Many piers were not repaired until the late 1940s or early 1950s.^[30]

Where a barrier to tanks was required, Admiralty scaffolding (also known as beach scaffolding or obstacle Z.1) was constructed. Essentially, this was a fence of scaffolding tubes 9 feet (2.7 m) high and was placed at low water so that tanks could not get a good run at it.^[31] Admiralty scaffolding was deployed along hundreds of miles of vulnerable beaches.^[32]

An even more robust barrier to tanks was provided by long lines of anti-tank cubes. The cubes were made of reinforced concrete 5 feet (1.5 m) to a side. Thousands were cast in situ in rows sometimes two or three deep.

The beaches themselves were overlooked by pillboxes of various types (see British hardened field defences of the Second World War). These were sometimes placed low down to get maximum advantage from enfilading fire whereas others were placed high up making them much harder to capture. Searchlights were installed at the coast to illuminate the sea surface and the beaches for artillery fire.^[33]^[34]^[35]“

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I also thought this article, on British hardened field defences (pillboxes), was quite fascinating. It seems to me that at least a few of the models were not much more than poorly constructed deathtraps, whereas some others were remarkably well constructed.

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ii. Bradford-Hill criteria. I was waiting a long time for these to be brought up (/mentioned?) during this lecture; they were never mentioned and along the way the lecturer made me start doubting whether he even knew the difference between a p-value and a correlation coefficient. Either way, the criteria are “a group of minimal conditions necessary to provide adequate evidence of a causal relationship between an incidence and a consequence” – here’s the list from the article:

Strength of association (relative risk, odds ratio)
Consistency
Specificity
Temporal relationship (temporality) – not heuristic; factually necessary for cause to precede consequence
Biological gradient (dose-response relationship)
Plausibility (biological plausibility)
Coherence
Experiment (reversibility)
Analogy (consideration of alternate explanations)

Do have these in mind the next time you come across an article on reddit (or wherever) explaining how ‘drinking X two times a week will prevent cancer’ or how ‘doing Y will minimize your risk of getting disease Z’ (or whatever). Of course in 1965, when the criteria were formulated, people had never even heard about stuff like Granger causality tests, vector autoregressive models and instrumental variable models. Establishing any kind of reasonably strong argument for a causal relationship between two sets of variables is very hard.

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iii. Minamata disease. Via mercury and mercury poisoning. It’s a horrible story and I think it’s pretty much certain that quite a few comparable disasters are unfolding right now elsewhere, e.g. in China. From the article:

“Minamata disease [...] is a neurological syndrome caused by severe mercury poisoning. Symptoms include ataxia, numbness in the hands and feet, general muscle weakness, narrowing of the field of vision and damage to hearing and speech. In extreme cases, insanity, paralysis, coma, and death follow within weeks of the onset of symptoms. A congenital form of the disease can also affect foetuses in the womb.

Minamata disease was first discovered in Minamata city in Kumamoto prefecture, Japan, in 1956. It was caused by the release of methylmercury in the industrial wastewater from the Chisso Corporation‘s chemical factory, which continued from 1932 to 1968. This highly toxic chemical bioaccumulated in shellfish and fish in Minamata Bay and the Shiranui Sea, which when eaten by the local populace resulted in mercury poisoning. While cat, dog, pig, and human deaths continued over more than 30 years, the government and company did little to prevent the pollution.

As of March 2001, 2,265 victims had been officially recognised (1,784 of whom had died)^[1] and over 10,000 had received financial compensation from Chisso.^[2] By 2004, Chisso Corporation had paid $86 million in compensation, and in the same year was ordered to clean up its contamination.^[3] On March 29, 2010, a settlement was reached to compensate as-yet uncertified victims.^[4]

A second outbreak of Minamata disease occurred in Niigata Prefecture in 1965. The original Minamata disease and Niigata Minamata disease are considered two of the Four Big Pollution Diseases of Japan.”

See also Patio process, a historically quite significant technique which improved the yields of silver mines in South America.

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iv. Recovery position.

“The recovery position refers to one of a series of variations on a lateral recumbent or three-quarters prone position of the body, in to which an unconscious but breathing casualty can be placed as part of first aid treatment.

An unconscious person (GCS <8) in a supine position (on their back) may not be able to maintain an open airway as a conscious person would.^[1] This can lead to an obstruction of the airway, restricting the flow of air and preventing gaseous exchange, which then causes hypoxia, which is life threatening. Thousands of fatalities occur every year in casualties where the cause of unconsciousness was not fatal, but where airway obstruction caused the patient to suffocate.^[2]^[3]^[4] The cause of unconsciousness can be any reason from trauma to intoxication from alcohol.”

You never know when you need to know stuff like this.

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v. Cassava.

“Cassava (Manihot esculenta), also called yuca, mogo, manioc, mandioca and kamoting kaoy a woody shrub of the Euphorbiaceae (spurge family) native to South America, is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy, tuberous root, a major source of carbohydrates. It differs from the similarly-spelled yucca, an unrelated fruit-bearing shrub in the Asparagaceae family. Cassava, when dried to a starchy, powdery (or pearly) extract is called tapioca, while its fermented, flaky version is named garri.

Cassava is the third-largest source of food carbohydrates in the tropics.^[1]^[2] Cassava is a major staple food in the developing world, providing a basic diet for around 500 million people.^[3] Cassava is one of the most drought-tolerant crops, capable of growing on marginal soils. Nigeria is the world’s largest producer of cassava.

Cassava root is a good source of carbohydrates, but a poor source of protein. A predominantly cassava root diet can cause protein-energy malnutrition.^[4]

Cassava is classified as sweet or bitter. Like other roots and tubers, Cassava contains anti-nutrition factors and toxins.^[5] It must be properly prepared before consumption. Improper preparation of cassava can leave enough residual cyanide to cause acute cyanide intoxication and goiters, and may even cause ataxia or partial paralysis.^[6] Nevertheless, farmers often prefer the bitter varieties because they deter pests, animals, and thieves.^[7] The more-toxic varieties of Cassava are a fall-back resource (a “food security crop”) in times of famine in some places.^[8]“

Using the toxic varieties as fall-back ressources is of course not exactly optimal. It can actually, and has, lead to really terrible outcomes (here’s the study Rosling talks about, I have not been able to find a non-gated version):

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vi. Solon. I’m sure that for most readers the name rings a bell, but what do you actually know about the guy? If you click the link, you’ll know more…

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vii. Emulsion.

“An emulsion is a mixture of two or more liquids that are normally immiscible (un-blendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the continuous phase are liquid. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, and some cutting fluids for metal working. The photo-sensitive side of photographic film is an example of a colloid.”

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viii. Onomatopoeia. Included because that’s just a neat word for something I didn’t know had a name:

An onomatopoeia or onomatopœia [...] from the Greek ὀνοματοποιία;^[1] ὄνομα for “name”^[2] and ποιέω for “I make”,^[3] adjectival form: “onomatopoeic” or “onomatopoetic”) is a word that imitates or suggests the source of the sound that it describes. Onomatopoeia (as an uncountable noun) refers to the property of such words. Common occurrences of onomatopoeias include animal noises, such as “oink” or “meow” or “roar”. Onomatopoeias are not the same across all languages; they conform to some extent to the broader linguistic system they are part of; hence the sound of a clock may be tick tock in English, dī dā in Mandarin, or katchin katchin in Japanese.”

(And now you know…)

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ix. Chemokine. It’s a technical article, but you can’t read it and not at least get the message that the human body is almost unbelievably complex.

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May 18, 2012 Posted by US | knowledge sharing, wikipedia | Leave a Comment

More ‘stuff’

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

(link)

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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.

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

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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.

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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.”

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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)

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vii. Romanization of Chinese.

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

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

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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.

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xi. Binary star.

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xii. Transform fault.

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May 3, 2012 Posted by US | books, Khan Academy, knowledge sharing, quotes, random stuff, wikipedia | Leave a Comment

Wikipedia articles of interest

1. Tuberculosis. I linked to it in a different post a while ago, but that post had a lot of links so people probably weren’t paying much attention at that point and/or following the link. Some highlights from the article:

“Tuberculosis, MTB, or TB (short for tubercle bacillus) is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis.[1] Tuberculosis usually attacks the lungs but can also affect other parts of the body. It is spread through the air when people who have an active MTB infection cough, sneeze, or otherwise transmit their saliva through the air.[2] Most infections in humans result in an asymptomatic, latent infection, and about one in ten latent infections eventually progress to active disease, which, if left untreated, kills more than 50% of those infected. [...]

One third of the world’s population is thought to have been infected with M. tuberculosis,[3][4] and new infections occur at a rate of about one per second.[3] In 2007 there were an estimated 13.7 million chronic active cases,[5] and in 2010 8.8 million new cases, and 1.45 million deaths, mostly in developing countries.[6] [...] The distribution of tuberculosis is not uniform across the globe; about 80% of the population in many Asian and African countries test positive in tuberculin tests, while only 5–10% of the U.S. population test positive.[1] [...]

Tuberculosis caused the most widespread public concern in the 19th and early 20th centuries as an endemic disease of the urban poor. In 1815, one in four deaths in England was of consumption; by 1918 one in six deaths in France were still caused by TB. After the establishment in the 1880s that the disease was contagious, TB was made a notifiable disease in Britain; there were campaigns to stop spitting in public places, and the infected poor were “encouraged” to enter sanatoria that resembled prisons; the sanatoria for the middle and upper classes offered excellent care and constant medical attention.[84] Whatever the purported benefits of the fresh air and labor in the sanatoria, even under the best conditions, 50% of those who entered were dead within five years (1916).[84] [...]

It was not until 1946 with the development of the antibiotic streptomycin that effective treatment and cure became possible. Prior to the introduction of this drug, the only treatment besides sanatoria were surgical interventions, including the pneumothorax technique—collapsing an infected lung to “rest” it and allow lesions to heal—a technique that was of little benefit and was largely discontinued by the 1950s.[90] The emergence of multidrug-resistant TB has again introduced surgery as part of the treatment for these infections. Here, surgical removal of chest cavities will reduce the number of bacteria in the lungs, as well as increasing the exposure of the remaining bacteria to drugs in the bloodstream, and is therefore thought to increase the effectiveness of the chemotherapy.[91]“

In completely unrelated news…

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2. Nitrogen cycle. A couple of images from the article:

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3. Bazooka. Lots of stuff I didn’t know. Here’s an interesting bit:

“A major disadvantage to the bazooka was the large backblast and smoke trail (in colder weather), which gave away the position of the shooter, mandating quick relocation of the squad. Moreover, the bazooka fire team often had to expose their bodies in order to obtain a clear field of fire against an armored target. Casualties among bazooka team members were extremely high during the war, and assignment to such duty, widely known as Medal of Honor work in the face of German counterfire was typically regarded by other platoon members as not only highly dangerous, but nearly suicidal.”

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4. Coal. Some stuff from the article:

“About 300 million years ago, the earth had dense forests in low-lying wetland areas. Due to natural processes, like flooding, these forests got buried under the soil. As more and more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. For the process to continue, the plant matter was protected from biodegradation and oxidization, usually by mud or acidic water. This trapped the carbon in immense peat bogs that are eventually covered and deeply buried by sediments. Under high pressure and high temperature dead vegetation got slowly converted to coal. As coal contains mainly carbon, the conversion of dead vegetation into coal is called carbonization.[4]

The wide shallow seas of the Carboniferous period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Lower Triassic, where coal is rare: presumably a result of the mass extinction which prefaced this era. Coal is known from Precambrian strata, which predate land plants: this coal is presumed to have originated from algal residues.[5][6] [...]

In 1700, 5/6 of the world’s coal was mined in Britain. Without coal, Britain would have run out of suitable sites for watermills by the 1830s.[21] In 1947, there were some 750,000 miners,[22] but by 2004 this had shrunk to some 5,000 miners working in around 20 collieries.[23] [...]

When coal is used for electricity generation, it is usually pulverized and then combusted (burned) in a furnace with a boiler.[28] The furnace heat converts boiler water to steam, which is then used to spin turbines which turn generators and create electricity. The thermodynamic efficiency of this process has been improved over time. Simple cycle steam turbines have topped out with some of the most advanced reaching about 35% thermodynamic efficiency for the entire process. Increasing the combustion temperature can boost this efficiency even further.[29] Old coal power plants, especially “grandfathered” plants, are significantly less efficient and produce higher levels of waste heat. At least 40% of the world’s electricity comes from coal,[28][30] and in 2008 approximately 49% of the United States’ electricity came from coal.[31] [...]

For a coal power plant with a 40% efficiency, it takes 325 kg (714 lb) of coal to power a 100 W lightbulb for one year.[60] [...]

Of the three fossil fuels, coal has the most widely distributed reserves; coal is mined in over 100 countries, and on all continents except Antarctica. The largest reserves are found in the USA, Russia, China, India and Australia.”

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5. Acanthochronology. File under: ‘You almost certainly did not know that this field of inquiry even existed.’

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6. Japanese aircraft carrier Shinano.

“Shinano [...] was an aircraft carrier of the Imperial Japanese Navy during World War II. Initially laid down as the third of the Yamato-class battleships, Shinano’s partially complete hull was converted to an aircraft carrier in 1942, midway through construction. Over the next two years, Shinano was heavily modified to act as a large support carrier. When completed, she had a full-load displacement of 72,000 long tons (73,000 t), the largest aircraft carrier ever built at the time.

Commissioned in November 1944, Shinano was to transfer from the Yokosuka Naval Shipyard to Kure Naval Base to complete her outfitting and transfer a load of 100 Yokosuka MXY7 Ohka rocket-propelled kamikaze aircraft. While en route, Shinano was sunk by the American submarine USS Archer-Fish 10 days after her commissioning — the result of severe design flaws, crew inexperience and poor damage control. To date, she is the largest warship to be sunk by a submarine.”

Some more details:

“On 19 November 1944, Shinano was formally commissioned at Yokosuka, having spent the previous two weeks fitting out and performing minor trials.[6] By 1 October the crew had reported on board, 70 to 75 percent of which had no previous sea duty experience.[7] As a result of growing worry for her safety, due to a U.S. bomber fly-over, Japanese Naval Command ordered Shinano to Kure, where the remainder of her fitting-out would take place.[6] Naval Command wanted Shinano moved to Kure no later than 28 November. However, Abe asked for a delay in the sailing date. The majority of her watertight compartment doors had yet to be installed, the compartment air tests had not been conducted, and many holes for electrical cables, ventilation ducts and pipes had not been sealed.[3] Nor had the fire mains or drainage systems been completed as pumps had not been delivered.[7] He also wanted more time to train his new crew, and to give the crews of the destroyers a rest after returning from battle.[5]

Abe’s request was denied” (…so Abe ended up dead at the bottom of the ocean, just like 1,434 others)

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7. South Pole–Aitken basin. It turns out that one of the largest known impact craters in the Solar System is to be found on the moon. I did not know that. It’s pretty damn big: “Roughly 2,500 kilometres (1,600 mi) in diameter and 13 kilometres (8.1 mi) deep. [...] The South Pole-Aitken basin is the largest, deepest and oldest basin recognized on the Moon.[1] The lowest elevations of the Moon (about -6 km) are located within the South Pole-Aitken basin, and the highest elevations (about +8 km) are found on this basin’s north-eastern rim. Because of this basin’s great size, the crust at this locale is expected to be thinner than typical as a result of the large amount of material that would have been excavated during this impact event. Crustal thickness maps constructed using the Moon’s topography and gravity field imply a thickness of about 15 km beneath the floor of this basin, in comparison to the global average of about 50 km.[4]“

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8. Columbian Exchange.

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March 25, 2012 Posted by US | knowledge sharing, wikipedia | Leave a Comment

Wikipedia articles of interest

1. Operation Mincemeat.

“Operation Mincemeat was a successful British deception plan during World War II. As part of the widespread deception plan Operation Barclay to cover the intended invasion of Italy from North Africa, Mincemeat helped to convince the German high command that the Allies planned to invade Greece and Sardinia in 1943 instead of Sicily, the actual objective. This was accomplished by persuading the Germans that they had, by accident, intercepted “top secret” documents giving details of Allied war plans. The documents were attached to a corpse deliberately left to wash up on a beach in Punta Umbría in Spain.”

This article is just fascinating and it’s hard to quote from it because the ploy is just so awesome you need to read it all, but here’s a bit more from the article:

“With the help of the renowned pathologist Sir Bernard Spilsbury, Montagu and his team determined what kind of body they needed: a man who appeared to have died at sea by hypothermia and drowning, and then floated ashore after several days. However, finding a usable body seemed almost impossible, as indiscreet inquiries would cause talk, and it was impossible to tell a dead man’s next of kin what the body was wanted for. Under quiet pressure, Bentley Purchase, coroner of St. Pancras District in London, obtained the body of a 34-year old Welsh man named Glyndwr Michael, on the condition that the man’s real identity would never be revealed. The man had died after ingesting rat poison which contained phosphorus. After being ingested, the phosphide reacts with hydrochloric acid in the human stomach, generating phosphine, a highly toxic gas. Coroner Purchase explained, “This dose was not sufficient to kill him outright, and its only effect was so to impair the functioning of the liver that he died a little time afterwards”, leaving few clues to the cause of death. Montagu later claimed the man died from pneumonia, and that the family had been contacted and permission obtained, but none of this was true. The dead man’s parents had died and no known relatives were found.[6]

The next step was creating a “legend”: a synthetic identity for the dead man. He became “Captain (Acting Major) William “Bill” Martin, Royal Marines”,[6] born 1907, in Cardiff, Wales, and assigned to Headquarters, Combined Operations. As a Royal Marine, Major Martin came under Admiralty authority, and it would be easy to ensure that all official inquiries and messages about his death would be routed to the Naval Intelligence Division. The Army’s arrangements were different and much harder to control. Also, he could wear battledress rather than a naval uniform (uniforms were tailor-made by Gieves of Savile Row, and they couldn’t have Gieves’s tailor measure a corpse.) The rank of acting Major made him senior enough to be entrusted with sensitive documents, but not so prominent that anyone would expect to know him. The name “Martin” was chosen because there were several Martins of about that rank in the Royal Marines.[3]

To build up the legend, they provided a fiancée named “Pam”. Major Martin carried a snapshot of “Pam” (actually a clerk named Jean Leslie from MI5),[6] two love letters, and a jeweller’s bill, dated 19th April 1943, from the exclusive S J Phillips Ltd of 113 New Bond Street, for a diamond engagement ring [...] In keeping with his rank, he was given some good quality underwear, at the time extremely difficult to obtain due to rationing. Items of woollen underwear owned by the late Herbert Fisher, the Master of New College Oxford, having been run over and killed by a lorry, were secured and used to underpin the verisimilitude of the body.[6]

He also had a pompous letter from his father, a letter from the family solicitor, and a letter from Ernest Whitley Jones, joint general manager of Lloyds Bank,[6] demanding payment of an overdraft of £79 19s 2d (£79.96). There were a book of stamps, a silver cross and St Christopher’s medallion, a pencil stub, keys, a used twopenny bus ticket,[6] ticket stubs from a London theatre, a bill for four nights’ lodging at the Naval and Military Club, and a receipt from Gieves & Hawkes for a new shirt [...] To make the Major even more believable, Montagu and his team decided to suggest that he was a bit careless. His ID card was marked as a replacement for one that had been lost, and his pass to Combined Operations HQ had expired a few weeks before his departure and not been renewed.”

2. Zebroid.

Of course I stumbled upon this article because of one of Razib Khan’s latest posts. Here’s an image of a zebonkey/zebrula/zedonk (naming conventions differ) from the article:

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March 8, 2012 Posted by US | knowledge sharing, wikipedia | Leave a Comment

Wikipedia articles of interest

i. Control of fire by early humans. I read about this stuff in The Human Past as well, but like in so many other cases wikipedia actually has a lot of stuff if you care to look for it. Wikipedia’s treatment of this subject does not seem to be out of line with the evidence presented in THP; generally it seems to be the case that people knew how to make fire around 125-130.000 years ago, but it is not clear when/where this ability first evolved (THP sums it up like this: “Spreads of burned sediment, ash, and charcoal that almost certainly signal fireplaces are conspicuous in many sites occupied by the European Neanderthals and their near-modern African contemporaries after 130,000 years ago, and it is generally assumed that people everywhere after 130,000 years ago could make fire when they needed it. The question is when this ability evolved, or perhaps more precisely, whether a stage of full control followed on one when fire use was sporadic and opportunistic. This issue is difficult to address since sites older than 130,000 years ago are relatively rare and they are mostly open-air localities.” [...] caves are far more likely to preserve fossil fireplaces.” p.117. The problem is that at an open-air site, it’s much more difficult to tell if the fire was made by humans or natural processes.)

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ii. Danish phonology. Some interesting aspects:

“Unlike the neighboring Mainland Scandinavian languages Swedish and Norwegian, the prosody of Danish does not have phonemic pitch. Stress is phonemic and distinguishes words like billigst [ˈb̥ilisd̥] “cheapest” and bilist [b̥iˈlisd̥] “car driver”. The main rules for the position of the stress are:

1. Inherited words are normally stressed on the first syllable.
2. The prefixes be-, for-, ge-, u- are unstressed, e.g. for’stå “understand”, be’tale “pay”, u’mulig “impossible” (NB there is also a stressed for- in nouns corresponding to the verbal prefix fore-).
3. In many compound adjectives, especially those ending in -ig and -lig, the stress is replaced from the first to the second syllable, e.g. vidt’løftig “circumstantial”, sand’synlig “probable”.
4. Words of French origin are stressed on the last syllable (except /ə/), e.g. renæ’ssance, mil’jø.
5. Words of Greek and Latin origin are stressed according to the Latin accent rules, i.e. stress on the penultimate if it is long or else on the antepenultimate, e.g. Ari’stoteles, Ho’rats.
6. The learned suffixes -aner, -ansk, -ance, -a/ens, -a/ent, -ere, -i, -ik, -ion, -itet, -ør are stressed, e.g. finge’rere, situa’tion, poli’tik, århusi’aner. The preceding syllable is stressed before the learned suffixes -isk, -iker, -or, e.g. po’lemisk, po’litiker, radi’ator. The suffix -or is stressed in the plural: radia’torer (colloquial: radi’atorer).
7. Verbs lose their stress (and stød, if any) in certain positions:

With an object without a definite or indefinite article: e.g. ’Jens ’spiser et ’barn [ˈjɛns ˈsb̥iːˀsɐ ed̥ ˈb̥ɑːˀn] “Jens eats a child” ~ ’Jens spiser ’børn [ˈjɛns sb̥isɐ ˈb̥ɶɐˀn] “Jens eats children”.
In a fixed phrase with an adverb or an adverbial: ’Helle ’sov ’længe [ˈhɛlə ˈsʌʊˀ ˈlɛŋə] “Helle slept for a long time” ~ ’Helle sov ’længe [ˈhɛlə sʌʊ ˈlɛŋə] “Helle slept late”.
Before the direction adverbs af, hen, hjem, ind, indad, ned, nedad, op, opad, over, ud, udad, under (but not the location adverbs henne. inde, nede, oppe, ovre, ude): e.g. han ’går ’ude på ’gaden [hæn ˈɡɒːˀ ˈuːð̪̩ pʰɔ ˈɡ̊æːð̪̩n] “he walks on the street” ~ han går ’ud på ’gaden [hæn ɡɒ ˈuð̪ˀ pʰɔ ˈɡ̊æːð̪̩n] “he walks into the street”.

Stød

The original pitch tone has been replaced by an opposition between syllables with and without the stød. The stød is not a separate phoneme, but a suprasegmental feature that may accompany certain syllables; those with a long vowel or that end with a voiced consonant.

The stød is phonemic since many words are kept apart on the basis of the presence or absence of the stød alone, e.g. løber “runner” [ˈløːb̥ɐ] ≠ løber “runs” [ˈløːˀb̥ɐ / ˈløʊ̯ˀɐ], ånden “breathing” [ˈʌnn̩] ≠ ånden “the spirit” [ˈʌnˀn̩].

It is impossible to predict the presence or absence of the stød; it has to be learned. However there are some main rules:

1. Original monosyllabic words have stød. Words that ended in consonant + r, l, n in Old Danish have the stød even though an anaptyctic vowel was later developed. The postposed definite article, which has become an inseparable part of the word, does not influence the word.
2. All umlauting plurals in -er (ODan. -r) have the stød, e.g. hænder [ˈhɛnˀɐ] “hands”.
3. Most presents from strong verbs (ODan. -r) have the stød, e.g. finder [ˈfenˀɐ] “finds”. Many of the presents of verbs with a preterite in -te have the stød as well (but not the presents of verbs with a preterite in -ede).
4. Monosyllabic words that originally ended in a short vowel + a single n, r, l, v, ð, g do not have the stød. However, when the definite suffix is added, the stød “returns”, e.g. ven [ˈʋɛn] ~ vennen [ˈʋɛnˀn̩] “friend”.
5. Stød is frequently avoided in words with the combinations rp, rt, rk, rs, e.g. vers [ˈʋæɐ̯s] “verse”, kort [ˈkʰɒːd̥] “card, map”/”short”.
6. Most (non-derived) words in -el, -er have the stød. Most words in -en do not have the stød. Nomina agentis in -er do not have the stød.
7. All words with the unstressed prefixes be-, for-, ge- have the stød.
8. There is stød in most compounds that have a replacement of the stress from first to the second syllable.
9. There is frequently the stød in the second part of compound verbs.
10. Monosyllables regularly lose the stød when they are the first part of a compound: mål [ˈmɔːˀl] “target, goal” ~ målmand [ˈmɔːlˌmænˀ] “goalkeeper”. The vowel is sometimes shortened: tag [ˈtˢæːˀ] “roof” ~ tagterrasse [ˈtˢɑʊ̯tˢaˌʁɑsə] ”roof terrace”
11. Words of Greek or Latin origin have the stød on a stressed antepenultimate syllable or a stressed last syllable. A stressed penultimate syllable has the stød if the word ends in -er.”

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The non-verbal aspects of human interaction increase the demands on the human brain to deal with complexity immensely in ways we don’t think about, but let’s not pretend that the verbal aspects are necessarily simple and easy to deal with. It’s very hard to remember how much you need to know and learn to master a human language unless you’re in the process of actively doing it.

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iii. Borromean rings.

“In mathematics, the Borromean rings[1] consist of three topological circles which are linked and form a Brunnian link, i.e., removing any ring results in two unlinked rings.”

They are weird, that’s what they are. Here’s an image from the article:

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iv. Terminal velocity. From the article:

“In fluid dynamics an object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the fluid through which it is moving.

A free-falling object achieves its terminal velocity when the downward force of gravity (FG) equals the upward force of drag (Fd). This causes the net force on the object to be zero, resulting in an acceleration of zero.[1]

As the object accelerates (usually downwards due to gravity), the drag force acting on the object increases, causing the acceleration to decrease. At a particular speed, the drag force produced will equal the object’s weight (mg). At this point the object ceases to accelerate altogether and continues falling at a constant speed called terminal velocity (also called settling velocity). An object moving downward with greater than terminal velocity (for example because it was thrown downwards or it fell from a thinner part of the atmosphere or it changed shape) will slow down until it reaches terminal velocity. [...]

The reason an object reaches a terminal velocity is that the drag force resisting motion is approximately proportional to the square of its speed. At low speeds, the drag is much less than the gravitational force and so the object accelerates. As it accelerates, the drag increases, until it equals the weight. Drag also depends on the projected area. This is why objects with a large projected area relative to mass, such as parachutes, have a lower terminal velocity than objects with a small projected area relative to mass, such as bullets.”

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v. Gyromitrin.

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vi. Caspase.

“Caspases, or cysteine-aspartic proteases or cysteine-dependent aspartate-directed proteases are a family of cysteine proteases that play essential roles in apoptosis (programmed cell death), necrosis, and inflammation.[2]

Caspases are essential in cells for apoptosis, or programmed cell death, in development and most other stages of adult life, and have been termed “executioner” proteins for their roles in the cell. Some caspases are also required in the immune system for the maturation of lymphocytes. Failure of apoptosis is one of the main contributions to tumour development and autoimmune diseases; this, coupled with the unwanted apoptosis that occurs with ischemia or Alzheimer’s disease, has stimulated interest in caspases as potential therapeutic targets since they were discovered in the mid-1990s.”

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vii. Darien scheme.

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viii. Cinderella effect.

“The Cinderella effect is a term used by psychologists to describe the high incidence of stepchildren being physically abused, emotionally abused, sexually abused, neglected, murdered, or otherwise mistreated at the hands of their stepparents at significantly higher rates than at the hands of their genetic parents. It takes its name from the fairy tale character Cinderella, who in the story was cruelly mistreated by her stepmother and stepsisters.”

The article is messy and I mostly included it in this post to give you the above (most people don’t click the links anyway – which is fine!).

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ix. Rotavirus. I remember reading a Danish article at some point about whether the vaccine against the Rotavirus A should be part of a national vaccine-program, but I can’t remember where I read about it. Why would you want a vaccine? Well:

“Rotavirus is the most common cause of severe diarrhoea among infants and young children,[1] and is one of several viruses that cause infections often called stomach flu, despite having no relation to influenza. It is a genus of double-stranded RNA virus in the family Reoviridae. By the age of five, nearly every child in the world has been infected with rotavirus at least once.[2] However, with each infection, immunity develops, and subsequent infections are less severe; adults are rarely affected.[3] There are five species of this virus, referred to as A, B, C, D, and E.[4] Rotavirus A, the most common, causes more than 90% of infections in humans.

The virus is transmitted by the faecal-oral route. It infects and damages the cells that line the small intestine and causes gastroenteritis. Although rotavirus was discovered in 1973[5] and accounts for up to 50% of hospitalisations for severe diarrhoea in infants and children,[6] its importance is still not widely known within the public health community, particularly in developing countries.[7] In addition to its impact on human health, rotavirus also infects animals, and is a pathogen of livestock.[8]

Rotavirus is usually an easily managed disease of childhood, but worldwide nearly 500,000 children under five years of age still die from rotavirus infection each year[9] and almost two million more become severely ill.[7] [...]

Rotavirus causes 37% of deaths attributable to diarrhoea and 5% of all deaths in children younger than five.[9]“

[my emphasis]

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I think perhaps the numbers of some of the sources in the article are incorrect or mixed up, presumably because new sources have been added at a later point – maybe I’ll go have a closer look and/or edit it later. Anyway, [6] from above tempts me to add a ‘not in source given’ tag, because I could not see how that claim was supported by the article after searching the document and skimming it to figure out where the claim came from. Maybe I’ll do that later. The article linked to from [6] is on the economics of RV gastroenteritis and vaccination. On the other hand, this article (found through Scholar, maybe it’s also one of the sources in the article – I haven’t looked) – Nosocomial rotavirus infection in European countries: a review of the epidemiology, severity and economic burden of hospital-acquired rotavirus disease – does support the claim in the wikipedia article:

“The data currently available on the epidemiology, severity and economic burden of nosocomial rotavirus (RV) infections in children younger than 5 years of age in the major European countries are reviewed. In most studies, RV was found to be the major etiologic agent of pediatric nosocomial diarrhea (31-87%), although the number of diarrhea cases associated with other virus infections (eg, noroviruses, astroviruses, adenoviruses) is increasing quickly and almost equals that caused by RVs. Nosocomial RV (NRV) infections are mainly associated with infants 0-5 months of age, whereas community-acquired RV disease is more prevalent in children 6-23 months of age. NRV infections are seasonal in most countries, occurring in winter; this coincides with the winter seasonal peak of other childhood virus infections (eg, respiratory syncytial virus and influenza viruses), thus placing a heavy burden on health infrastructures. A significant proportion (20-40%) of infections are asymptomatic, which contributes to the spread of the virus and might reduce the efficiency of prevention measures given as they are implemented too late. The absence of effective surveillance and of reporting of NRV infections in any of the 6 countries studied (France, Germany, Italy, Poland, Spain and the United Kingdom) results in severe underreporting of NRV cases in hospital databases and therefore in limited awareness of the importance of NRV disease at country level. The burden reported in the medical literature is potentially significant and includes temporary reduction in the quality of children’s lives, increased costs associated with the additional consumption of medical resources (increased length of hospital stay) and constraints on parents’/hospital staff’s professional lives.”

If you, like me, didn’t know what a nocosomial infection is, well that’s just a hospital-acquired infection. RV-infections are not nocosomial infections.

Citations in the wikipedia article are also problematic because I became aware that not all of them are direct citations; for instance, [2] leads to this article – Rotavirus Overview: The Pediatric Infectious Disease Journal – but that’s a secondary source to the claim. The primary source is a CDC-report: “Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases. Atkinson W, Hamborsky J, McIntyre L, et al, eds. 10th ed. Washington, DC: Public Health Foundation; 2007:295-306.”

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(Sorry for the lack of updates, this is a difficult time for me.)

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February 26, 2012 Posted by US | data, knowledge sharing, medicine, studies, wikipedia | Leave a Comment

Wikipedia articles of interest

1. Economy of the Han Dynasty. I’ve read about this elsewhere as well, but it turns out that wikipedia has some good stuff on the subject (‘Han Dynasty’ is one of Wikipedia’s featured topics).

2. Effect of psychoactive drugs on animals. It’s not a long article, but I had to link to it because of these awesome images:

If you’d rather read about the caffeine that’s having such a huge effect on spiders, here’s the article. Here’s one bit that I found interesting:

“Extreme overdose can result in death.[48][49] The median lethal dose (LD50) given orally, is 192 milligrams per kilogram in rats. The LD50 of caffeine in humans is dependent on individual sensitivity, but is estimated to be about 150 to 200 milligrams per kilogram of body mass or roughly 80 to 100 cups of coffee for an average adult.[4] Though achieving lethal dose with caffeine would be exceptionally difficult with regular coffee, there have been reported deaths from overdosing on caffeine pills, with serious symptoms of overdose requiring hospitalization occurring from as little as 2 grams of caffeine. An exception to this would be taking a drug such as fluvoxamine or levofloxacin, which blocks the liver enzyme responsible for the metabolism of caffeine, thus increasing the central effects and blood concentrations of caffeine five-fold.[47][48][49][50] Death typically occurs due to ventricular fibrillation brought about by effects of caffeine on the cardiovascular system.”

3. Schwarzschild radius.

“The Schwarzschild radius (sometimes historically referred to as the gravitational radius) is the distance from the center of an object such that, if all the mass of the object were compressed within that sphere, the escape speed from the surface would equal the speed of light.” (The article has much more.)

4. Peasants’ Revolt.

“The Peasants’ Revolt, Wat Tyler’s Rebellion, or the Great Rising of 1381 was one of a number of popular revolts in late medieval Europe and is a major event in the history of England. Tyler’s Rebellion was not only the most extreme and widespread insurrection in English history but also the best-documented popular rebellion to have occurred during medieval times. The names of some of its leaders, John Ball, Wat Tyler and Jack Straw, are still familiar in popular culture, although little is known of them.

The revolt later came to be seen as a mark of the beginning of the end of serfdom in medieval England, although the revolt itself was a failure. It increased awareness in the upper classes of the need for the reform of feudalism in England and the appalling misery felt by the lower classes as a result of their enforced near-slavery.”

5. Przewalski’s horse.

I found the information about the conservation efforts fascinating – this species was saved even though it was about as close to extinction as a species could possibly get. And not only did they survive, some have even been succesfully reintroduced into the wild:

“Przewalski’s horse [...] or Dzungarian horse, is a rare and endangered subspecies of wild horse (Equus ferus) native to the steppes of central Asia, specifically China and Mongolia.[3] At one time extinct in the wild, it has been reintroduced to its native habitat in Mongolia at the Khustain Nuruu National Park, Takhin Tal Nature Reserve and Khomiin Tal. [...]

The world population of these horses are all descended from 9 of the 31 horses in captivity in 1945.[9] These nine horses were mostly descended from approximately 15 captured around 1900. A cooperative venture between the Zoological Society of London and Mongolian scientists has resulted in successful reintroduction of these horses from zoos into their natural habitat in Mongolia; and as of 2011 there is an estimated free-ranging population of over 300 in the wild.[10] The total number of these horses according to a 2005 census was about 1,500.”

Here are some related links.

6. Strategic dominance (game theory).

7. Collatz conjecture.

“Take any natural number n. If n is even, divide it by 2 to get n / 2. If n is odd, multiply it by 3 and add 1 to obtain 3n + 1. Repeat the process (which has been called “Half Or Triple Plus One”, or HOTPO[4]) indefinitely. The conjecture is that no matter what number you start with, you will always eventually reach 1. The property has also been called oneness.[5]” (long article, lots of stuff including several examples.)

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February 9, 2012 Posted by US | knowledge sharing, wikipedia | Leave a Comment

Wikipedia articles of interest

1. Dutch East India Company.

“The Dutch East India Company (Dutch: Vereenigde Oost-Indische Compagnie, VOC, “United East India Company”) was a chartered company established in 1602, when the States-General of the Netherlands granted it a 21-year monopoly to carry out colonial activities in Asia. It was the second multinational corporation in the world (the British East India Company was founded two years earlier) and the first company to issue stock.[2] It was also arguably the first megacorporation, possessing quasi-governmental powers, including the ability to wage war, imprison and execute convicts,[3] negotiate treaties, coin money, and establish colonies.[4]

Statistically, the VOC eclipsed all of its rivals in the Asia trade. Between 1602 and 1796 the VOC sent almost a million Europeans to work in the Asia trade on 4,785 ships, and netted for their efforts more than 2.5 million tons of Asian trade goods. By contrast, the rest of Europe combined sent only 882,412 people from 1500 to 1795, and the fleet of the English (later British) East India Company, the VOC’s nearest competitor, was a distant second to its total traffic with 2,690 ships and a mere one-fifth the tonnage of goods carried by the VOC. The VOC enjoyed huge profits from its spice monopoly through most of the 17th century.[5] [...]

By 1669, the VOC was the richest private company the world had ever seen, with over 150 merchant ships, 40 warships, 50,000 employees, a private army of 10,000 soldiers, and a dividend payment of 40% on the original investment.[23] [...]

However, from there on [1730] the fortunes of the VOC started to decline. Five major problems, not all of equal weight, can be adduced to explain its decline in the next fifty years to 1780.[38]

There was a steady erosion of intra-Asiatic trade by changes in the Asiatic political and economic environment that the VOC could do little about. These factors gradually squeezed the company out of Persia, Suratte, the Malabar Coast, and Bengal. The company had to confine its operations to the belt it physically controlled, from Ceylon through the Indonesian archipelago. The volume of this intra-Asiatic trade, and its profitability, therefore had to shrink.
The way the company was organized in Asia (centralized on its hub in Batavia) that initially had offered advantages in gathering market information, began to cause disadvantages in the 18th century, because of the inefficiency of first shipping everything to this central point. This disadvantage was most keenly felt in the tea trade, where competitors like the EIC and the Ostend Company shipped directly from China to Europe.
The “venality” of the VOC’s personnel (in the sense of corruption and non-performance of duties), though a problem for all East-India Companies at the time, seems to have plagued the VOC on a larger scale than its competitors. To be sure, the company was not a “good employer”. Salaries were low, and “private-account trading” was officially not allowed. Not surprisingly, it proliferated in the 18th century to the detriment of the company’s performance.[39] From about the 1790s onward, the phrase perished by corruption (also abbreviated VOC in Dutch) came to summarize the company’s future.
A problem that the VOC shared with other companies was the high mortality and morbidity rates among its employees. This decimated the company’s ranks and enervated many of the survivors.
A self-inflicted wound was the VOC’s dividend policy. The dividends distributed by the company had exceeded the surplus it garnered in Europe in every decade but one (1710–1720) from 1690 to 1760. However, in the period up to 1730 the directors shipped resources to Asia to build up the trading capital there. Consolidated bookkeeping therefore probably would have shown that total profits exceeded dividends. In addition, between 1700 and 1740 the company retired 5.4 million guilders of long-term debt. The company therefore was still on a secure financial footing in these years. This changed after 1730. While profits plummeted the bewindhebbers only slightly decreased dividends from the earlier level. Distributed dividends were therefore in excess of earnings in every decade but one (1760–1770). To accomplish this, the Asian capital stock had to be drawn down by 4 million guilders between 1730 and 1780, and the liquid capital available in Europe was reduced by 20 million guilders in the same period. The directors were therefore constrained to replenish the company’s liquidity by resorting to short-term financing from anticipatory loans, backed by expected revenues from home-bound fleets.”

2. Plastid.

3. Collision cascade.

4. Ablation.

5. Second Persian invasion of Greece. A nice image from the article:

6. Tidal force.

7. La Tène culture.

8. Effective population size (genetics)

“the number of breeding individuals in an idealized population that would show the same amount of dispersion of allele frequencies under random genetic drift or the same amount of inbreeding as the population under consideration.”

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January 28, 2012 Posted by US | knowledge sharing, wikipedia | Leave a Comment

Stuff

i. “Jesus said to his disciples: “Things that cause people to stumble are bound to come, but woe to anyone through whom they come. It would be better for them to be thrown into the sea with a millstone tied around their neck than to cause one of these little ones to stumble.” (Luke 17, quote found here).

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ii. Dimetrodon. Image from the article:

“a predatory synapsid genus that flourished during the Permian period, living between 280–265 million years ago (during the Artinskian to Capitanian stages).

As a synapsid it was more closely related to mammals than to true reptiles such as lizards and snakes. It is classified as a pelycosaur. Fossils of Dimetrodon have been found in North America and Europe. Dimetrodon had a sail on its back, which is known to have been used for regulating body temperature. [...]

Dimetrodon has two types of teeth, shearing teeth and sharp canine teeth. Its name, in fact, means “two-measures of teeth”. Dimetrodon was one of the first animals with differentiated teeth and the teeth were suitable for killing animals then tearing them to pieces. [...]

The spines of Dimetrodon have grooves on the base that were presumably ingested by blood vessels and thus ensured good bloodflow through the skin of the sail. The theory is that Dimetrodon was active in the early morning when the sun rose. The sail would be pointed towards the sun and would absorb heat allowing rapid warming. This allowed Dimetrodon to hunt at a time when other animals were not sufficiently warmed up and were slow. The sail increased body surface area by 50%. According to calculations by Bramwell Fellgett, it took a 200 kg (440 lb) Dimetrodon approximately one and a half hours for its body temperature to go from 26 to 32 °C (79 to 90 °F) [13] A study by Haack concluded that warming was slower than previously thought and that the process probably took four hours.[14] In order to cool its body in the hot midday sun, Dimetrodon turned its sail away from the sun, causing the heat to drain. The rapid warming using the sail give Dimetrodon an edge over larger animals, weighing over 55 kg. Smaller animals had higher body surface-to-mass ratio, making them hotter than Dimetrodon. The prey of Dimetrodon would therefore have been mostly large animals like Diadectes, Eryops and Ophiacodon. The changing climate during the Permian period, when the temperature increased, is a possible reason for the extinction of Dimetrodon since the sail meant no benefit over other animals and was rather a disadvantage due to its fragility.”

Even though in most Western cultures there seem to be quite a bit of focus on dinosaurs and the Mesozoic and a lot less focus on what came before that, it’s worth remembering that there was a lot of stuff going on before life ever got to the dinosaurs.

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iii. A quote:

“My model of this situation is less sanguine than others here, though Yvain and Tetronian hinted at it: it’s identity politics. Humans very naturally associate themselves with many different groups, some of them arbitrarily defined, and often without any conscious thought. Religion, favorite sports teams, the street/neighborhood/city/state/country you live in, and many other things can be the focal point of these groups. The more you associate with one of these groups, the more its part of your identity – i.e. how you see yourself. If you associate with one of these groups particularly strongly, any action which appears to make a rival group look better will personally offend you and elicit a response.”

In general, on a related note I think that the likelihood that an argument will escalate (conflict level will increase) is increasing in n in most naturally occuring settings. When two people argue nobody else is watching – which means that there are nobody else there to impress/defend. The more people are watching, the more people will witness a status loss or a status gain resulting from the argument. Also, once several people are involved coalitions will start to form naturally and you’ll start to not only be defending yourself but also feel that you have a duty (due to implicit community norms ect.) to defend the tribe. Gender also matters; in my (admittedly limited) experience, a male with a female partner arguing with another male will argue ‘more strongly’ for X if the partner is present than if she is not (unless the female makes clear that she considers the argument irrelevant; if she does and the male picks up on that signal, he’ll be likely to ‘fold’ whether or not he ‘was winning’ (…which of course he was)). Also, males are probably likely to a) be more aggresive (conflict-prone) if there are women present, and b) be more -ll- if the gender ratio is skewed ‘against them’ (# males >> # females) and less likely to be -ll- if the gender ratio is skewed ‘in their favour’ (# males << # females).

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iv. Square/Cube Law. (see also wikipedia)

“When an object undergoes a proportional increase in size, its new volume is proportional to the cube of the multiplier and its new surface area is proportional to the square of the multiplier.

For example, if you double the size (measured by edge length) of a cube, its surface area is quadrupled, and its volume is increased by eight times.

The point of this law is that with living beings, muscle strength is (more or less) a function of surface area, but weight is a function of volume. And Newton’s famous Second Law (the “force = mass * acceleration” one) means that if you double a critter’s size, you end up with four times the muscle power moving eight times the mass, so instead of having the same relative agility as the original, the double-sized creature actually has only half.

This applies to flyers as well: Double the size, and you get four times the wingpower attempting to keep eight times the weight airborne, so the creature’s ability to fly has actually been cut by half.”

Part of why dung beetles can roll up to 50 times their own weight (/and why we can’t).

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v. “The ancient Greeks and Romans used torture for interrogation. Until the 2nd century AD, torture was used only on slaves (with a few exceptions). After this point it began to be extended to all members of the lower classes. A slave’s testimony was admissible only if extracted by torture, on the assumption that slaves could not be trusted to reveal the truth voluntarily.[12]” (wikipedia)

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vi. Swaziland

“Swaziland, officially the Kingdom of Swaziland (Umbuso weSwatini), and sometimes called Ngwane or Swatini, is a landlocked country in Southern Africa, bordered to the north, south and west by South Africa, and to the east by Mozambique. The nation, as well as its people, are named after the 19th century king Mswati II.

Swaziland is a small country, no more than 200 kilometres (120 mi) north to south and 130 kilometres (81 mi) east to west. [...]

Some 75% of the population are employed in subsistence farming, and 60% of the population live on less than the equivalent of US$1.25 per day. [...]

Swaziland’s economic growth and societal integrity is highly endangered by its disastrous HIV epidemic, to an extent where the United Nations Development Program has written that if it continues unabated, the “longer term existence of Swaziland as a country will be seriously threatened.”[5] The infection rate in the country is unprecedented and the highest in the world at 26.1% of adults[6] and over 50% of adults in their 20s.[5] [...]

…Swaziland has the highest HIV infection rate in the world [...] and also the lowest life expectancy at 32 years, which is 6 years lower than the next lowest average of Angola. From another perspective, the last available World Health Organization data in 2002 shows that 64% of all deaths in the country were caused by HIV/AIDS.[11] [...]

In 2004, Swaziland acknowledged for the first time that it suffered an AIDS crisis, with 38.8% of tested pregnant women infected with HIV [...] Life expectancy has fallen from 61 years in 2000 to 32 years in 2009.[15]“

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January 19, 2012 Posted by US | Africa, data, knowledge sharing, Psychology, quotes, wikipedia | 1 Comment

Wikipedia articles of interest

1. External ballistics.

“External ballistics is the part of the science of ballistics that deals with the behaviour of a non-powered projectile in flight. External ballistics is frequently associated with firearms, and deals with the behaviour of the bullet after it exits the barrel and before it hits the target.”

2. Propaganda in the Soviet Union.

“The main Soviet censorship body, Glavlit, employed 70,000 full-time staff not only to eliminate any undesirable printed materials, but also “to ensure that the correct ideological spin was put on every published item”.”

And Glavlit wasn’t even the only censorship body in the Soviet Union. Also:

“CIA estimated in 1980s that the budget of Soviet propaganda abroad was between 3.5-4.0 billion dollars.” [...] “Propaganda abroad was partly conducted by Soviet intelligence agencies. GRU alone spent more than $1 billion for propaganda and peace movements against Vietnam War”

3. Concussion (this is a ‘good article’).

4. Crypsis. “In ecology, crypsis is the ability of an organism to avoid observation or detection by other organisms. It may be either a predation strategy or an antipredator adaptation, and methods include camouflage, nocturnality, subterranean lifestyle, transparency,[2] and mimicry.”

The article has this awesome image (click to view in higher res.):

The frog you’re looking for is just to the left of the top end of the vertical stick. Can you see it? I couldn’t. Go here for an image up close where you can see the frog highlighted.

5. Ascomycota.

“The Ascomycota are a Division/Phylum of the kingdom Fungi, and subkingdom Dikarya. Its members are commonly known as the Sac fungi. They are the largest phylum of Fungi, with over 64,000 species.[2] The defining feature of this fungal group is the “ascus” (from Greek: ἀσκός (askos), meaning “sac” or “wineskin”), a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. [...]

The ascomycetes are a monophyletic group, i.e., all of its members trace back to one common ancestor. This group is of particular relevance to humans as sources for medicinally important compounds, such as antibiotics and for making bread, alcoholic beverages, and cheese, but also as pathogens of humans and plants. Familiar examples of sac fungi include morels, truffles, brewer’s yeast and baker’s yeast, Dead Man’s Fingers, and cup fungi. The fungal symbionts in the majority of lichens (loosely termed “ascolichens”) such as Cladonia belong to the Ascomycota. There are many plant-pathogenic ascomycetes, including apple scab, rice blast, the ergot fungi, black knot, and the powdery mildews. Several species of ascomycetes are biological model organisms in laboratory research. Most famously Neurospora crassa, several species of yeasts, and Aspergillus species are used in many genetics and cell biology studies. Penicillium species on cheeses and those producing antibiotics for treating bacterial infectious diseases are examples of taxa that belong to the Ascomycota.”

The article has lots of additional links if you want to know more.

6. Cameroon. (this is a featured article)

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January 9, 2012 Posted by US | knowledge sharing, wikipedia | Leave a Comment

Wikipedia articles of interest

i. Silk Road.

“The Silk Routes (collectively known as the “Silk Road”) were important trade routes for goods of all kinds between merchants, pilgrims, missionaries, soldiers, nomads and urban dwellers from Ancient China, Ancient India, Ancient Tibet, the Persian Empire and Mediterranean countries for almost 3,000 years.[5] It gets its name from the lucrative Chinese silk trade, which began during the Han Dynasty (206 BCE – 220 CE).

Extending 4,000 miles (6,500 km), the routes enabled traders to transport goods, slaves and luxuries such as silk, satin, hemp and other fine fabrics, musk, other perfumes, spices, medicines, jewels, glassware and even rhubarb, as well as serving as a conduit for the spread of knowledge, ideas, cultures, zoological specimens and some non-indigenous disease conditions[6] between Ancient China, Ancient India, Asia Minor and the Mediterranean. Trade on the Silk Road was a significant factor in the development of the great civilizations of China, India, Egypt, Persia, Arabia, and Rome, and in several respects helped lay the foundations for the modern world. Although the term the Silk Road implies a continuous journey, very few who traveled the route traversed it from end to end. For the most part, goods were transported by a series of agents on varying routes and were traded in the bustling markets of the oasis towns.[6] [...]

By the time of Herodotus (c. 475 BCE), the Persian Royal Road ran some 2,857 km from the city of Susa on the Karun (250 km east of the Tigris) to the port of Smyrna (modern İzmir in Turkey) on the Aegean Sea.[66] It was maintained and protected by the Achaemenid Empire (c.500–330 BCE), and had postal stations and relays at regular intervals. By having fresh horses and riders ready at each relay, royal couriers could carry messages the entire distance in nine days, though normal travellers took about three months. [...]

The Mongol expansion throughout the Asian continent from around 1207 to 1360 helped bring political stability and re-establish the Silk Road (via Karakorum). It also brought an end to the Islamic Caliphate’s monopoly over world trade. Since the Mongol had dominated the trade routes, it allowed more trade to come in and out of the region. Merchandise that did not seem valuable to the Mongols was often seen as very valuable by the west. As a result, the Mongol received in return a large amount of luxurious goods from the West.”

The mongol? But those were just a small group of nomadic people living around the north-western borders of China, right – how come they had such a huge influence on world trade? Well, perhaps you know but a lot of people don’t: “[The Mongol Empire] is commonly referred to as the largest contiguous empire in the history of the world. At its greatest extent it spanned 9,700 km (6,000 mi), covered an area of 24,000,000 km2 (9,300,000 sq mi),[1][2][3][4] 16% of the Earth’s total land area”.

ii. House of Medici.

iii. Rosetta Stone (this is a featured article).

“The Rosetta Stone is an ancient Egyptian granodiorite stele inscribed with a decree issued at Memphis in 196 BC on behalf of King Ptolemy V. The decree appears in three scripts: the upper text is Ancient Egyptian hieroglyphs, the middle portion Demotic script, and the lowest Ancient Greek. Because it presents essentially the same text in all three scripts (with some minor differences between them), it provided the key to the modern understanding of Egyptian hieroglyphs.”

iv. RNA interference (this is also a featured article).

v. Timeline of Chinese history. It wouldn’t make sense to quote from this, but don’t miss it, at least go have a look. Here’s more.

vi. Blood type.

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November 29, 2011 Posted by US | knowledge sharing, wikipedia | 1 Comment

Wikipedia articles of interest

I tend to think that the last couple of wikipedia articles posts I’ve posted weren’t all that good, sorry about that. Anyway, some of these articles were great:

i. Cooperative principle (& Grice’s Maxims)

“In social science generally and linguistics specifically, the cooperative principle describes how people interact with one another. As phrased by Paul Grice, who introduced it, it states, “Make your contribution such as it is required, at the stage at which it occurs, by the accepted purpose or direction of the talk exchange in which you are engaged.” Though phrased as a prescriptive command, the principle is intended as a description of how people normally behave in conversation.

Listeners and speakers must speak cooperatively and mutually accept one another to be understood in a particular way. The cooperative principle describes how effective communication in conversation is achieved in common social situations.

The cooperative principle can be divided into four maxims, called the Gricean maxims, describing specific rational principles observed by people who obey the cooperative principle; these principles enable effective communication.” [...]

“Grice’s Maxims

Maxim of Quality

Be Truthful
*Do not say what you believe to be false
*Do not say that for which you lack adequate evidence.

Maxim of Quantity

Quantity of Information
*Make your contribution as informative as is required (for the current purposes of the exchange).
*Do not make your contribution more informative than is required.

Maxim of Relevance

Relevance
Be relevant. [...]

Maxim of Manner

Be Clear
Avoid obscurity of expression.
Avoid ambiguity.
Be brief (avoid unnecessary prolixity).
Be orderly.”

…

Even though the article makes it clear that these maxims are not to be considered prescriptive but rather descriptive, the piece in which he introduces them basically contains no data analysis whatsoever. And really, who needs data anyway when you can just postulate that “it is just a well-recognized empirical fact that people do behave in these ways…” (p.28-29). If I ever happen to refer to these maxims in the future, expect me to apply them as sensible prescriptive rules and nothing else; and seriously, I really think the guy who made them up should have limited himself to that as well. It’s not that they are wrong, it’s worse than that – I don’t see how they’re even testable. It’s perfectly simple to come up with examples where the maxims are violated and examples where it’s not hard to argue that they are not, but there’s a lot of stuff in between. Wikipedia also has an article on some related politeness maxims.

Incidentally, following simple ‘rules’ like these – whether you are explicitly aware of the fact that you do it or not – is actually pretty important in some contexts. I can think of at least two Danish bloggers (I won’t name names) who I’ve debated in the past who (…”in my mind”…; remember that this is a big part of the reason why it’s so hard to evaluate these maximes empirically – people have different standards of evidence, information requirements, ect.) so systematically violated these maxims every time we had a discussion that I eventually gave up any interaction with them. Obfuscation, ambiguity, irrelevant remarks, arguments based on insufficient data – that stuff is poison to any debate and I won’t engage people who add a lot of that stuff to the conversation, whether they do it deliberately or not. (I should probably add here that none of the readers who currently comment here are even close to violating any kind of ‘code of conduct-rules’ – you do brilliantly (which is why you should all comment more often ). Of course, the above remarks also point to a second problem related to the maxims and the cooperative principle: Optimizing the efficiency of the information exchange that takes place is often not a main goal when people communicate, and doing it anyway can be suboptimal. Think of gossip related to bonding and tribal affiliations/coalition forming. Think of verbal communication along the lines of this discussion between Will and ‘the jerk’ – these kinds of discussions are status games and little else; zero sum, the winner gets the girl. Political discussions are often zero-sum; ‘the winner’ gets more power and status, ‘the loser’ loses face. There are a lot of settings where humans communicate with each others and where an approach of cooperation does not make sense even in theory.

ii. French and Indian War

“The French and Indian War is the common American name for the war between Great Britain and France in North America from 1754 to 1763. In 1756, the war erupted into the world-wide conflict known as the Seven Years’ War and thus came to be regarded as the North American theater of that war.” [...] The war in North America officially ended with the signing of the Treaty of Paris on February 10, 1763, and war in the European theatre of the Seven Years’ War was settled by the Treaty of Hubertusburg on February 15, 1763. The British offered France a choice of either its North American possessions east of the Mississippi or the Caribbean islands of Guadeloupe and Martinique, which had been occupied by the British. France chose to cede Canada, and was able to negotiate the retention of Saint Pierre and Miquelon, two small islands in the Gulf of St. Lawrence, and fishing rights in the area. The economic value of the Caribbean islands to France was greater than that of Canada because of their rich sugar crops, and they were easier to defend. The British, however, were happy to take New France, as defense was not an issue, and they already had many sources of sugar. Spain, which traded Florida to Britain to regain Cuba, also gained Louisiana, including New Orleans, from France in compensation for its losses. Navigation on the Mississippi was to be open to all nations. [...]

The war changed economic, political, governmental and social relations between three European powers (Britain, France, and Spain), their colonies and colonists, and the natives that inhabited the territories they claimed. France and Britain both suffered financially because of the war, with significant long-term consequences. [...] The Seven Years’ War nearly doubled Britain’s national debt. The Crown, seeking sources of revenue to pay off the debt, attempted to impose new taxes on its colonies. These attempts were met with increasingly stiff resistance, until troops were called in so that representatives of the Crown could safely perform their duties. These acts ultimately led to the start of the American Revolutionary War.[60]

France attached comparatively little value to its North American possessions, especially in respect to the highly profitable sugar-producing Antilles islands, which it managed to retain. Minister Choiseul considered he had made a good deal at the Treaty of Paris, and philosopher Voltaire wrote that Louis XV had only lost “a few acres of snow”.[61] For France however, the military defeat and the financial burden of the war weakened the monarchy and contributed to the advent of the French Revolution in 1789.[62]“

Here are two maps from the article (I’ve modified the first a bit to make it fit the page, but no significant detail was lost. I decided it was better to just put in a thumbnail of the other, click on it to view that one in full resolution):

iii. Dodecahedron.

iv. Chemotaxis. Of course I stumbled upon this one while reading Human Microbiology.

“Chemotaxis is the phenomenon in which somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food (for example, glucose) by swimming towards the highest concentration of food molecules, or to flee from poisons (for example, phenol). In multicellular organisms, chemotaxis is critical to early development (e.g. movement of sperm towards the egg during fertilization) and subsequent phases of development (e.g. migration of neurons or lymphocytes) as well as in normal function. In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis.

Positive chemotaxis occurs if the movement is towards a higher concentration of the chemical in question. Conversely, negative chemotaxis occurs if the movement is in the opposite direction.” [...]

“The overall movement of a bacterium is the result of alternating tumble and swim phases. If one watches a bacterium swimming in a uniform environment, its movement will look like a random walk with relatively straight swims interrupted by random tumbles that reorient the bacterium. Bacteria such as E. coli are unable to choose the direction in which they swim, and are unable to swim in a straight line for more than a few seconds due to rotational diffusion. In other words, bacteria “forget” the direction in which they are going. By repeatedly evaluating their course, and adjusting if they are moving in the wrong direction, bacteria can direct their motion to find favorable locations with high concentrations of attractants (usually food) and avoid repellents (usually poisons).

In the presence of a chemical gradient bacteria will chemotax, or direct their overall motion based on the gradient. If the bacterium senses that it is moving in the correct direction (toward attractant/away from repellent), it will keep swimming in a straight line for a longer time before tumbling. If it is moving in the wrong direction, it will tumble sooner and try a new direction at random. In other words, bacteria like E. coli use temporal sensing to decide whether life is getting better or worse. In this way, it finds the location with the highest concentration of attractant (usually the source) quite well. Even under very high concentrations, it can still distinguish very small differences in concentration. Fleeing from a repellent works with the same efficiency.”

v. Dyson sphere.

vi. Hermann Detzner (if you haven’t heard about that guy, don’t beat yourself up. Neither had I, until I read this article. I knew a little about the Japanese holdouts after WW2 before reading this, but until now I had never heard about holdouts from WW1.)

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November 9, 2011 Posted by US | knowledge sharing, wikipedia | 7 Comments

Earth (some stuff you should know)

I had an interesting discussion yesterday which touched briefly upon a few of these subjects, so I decided to take a closer look at the data just to make sure I wasn’t completely wrong about the stuff I thought I knew – and now I’m glad I did as I seem to have somehow picked up a mistaken idea about the land area of the Southern Hemisphere (I thought it was even smaller than it is). Now, if you asked a random guy he wouldn’t know most of these numbers or even the relevant neighbourhood. Somehow I feel like people should. So here we go, most of these numbers are pulled from wikipedia:

1. Asia covers 8.7 % of the Earth’s total surface area and hosts ~60 % of the world’s current human population. It covers 29.5 % of the land area of Earth.

1a. Africa covers 6 % of the Earth’s total surface area and hosts ~14-15 % of the world’s population. It covers 20.4% of the total land area.

1b. North America: 4.8 % of surface area, 8 % of population. 16.5 % of total land area.

1c. South America: 3.5 % of surface area, 6 % of population. 12.0 % of total land area.

1d. Antarctica: 2.7 % of surface area, 0 % of population. 9.2% of total land area.

1e. Europe: 2 % of surface area, 11.5 % of population. 6.8 % of total land area.

1f. Australia: 1.5 % of surface area, 0.5 % of population. 5.1 % of total land area.

2. Russia covers 17,075,400 square kilometres. Europe and Australia combined make out ~17,8 mio. square kilometres, a number which incidentally is about the same as South America. So if we for a moment disregard the fact that Russia already makes up 40 % of the total area of Europe, it’s large enough to almost cover the two smallest continents combined.

3. According to a 2010 census, the population of China was/is 1,339,724,852 – which is more than 19 % of the population of Earth. This is a higher population than that of any single continent which is not Asia. The population of China is significantly larger than the combined populations of South America (385,7 mio), North America (529 mio) and Australia (31,26). It’s larger than the combined populations of Europe and North America. Here’s a neat image comparing sizes and populations of the continents.

4. This source notes that: “In the Northern Hemisphere, the ratio of land to ocean is about 1 to 1.5. The ratio of land to ocean in the Southern Hemisphere is 1 to 4.” Translating those ratios into percentages of the hemispheres, it turns out that in the Northern Hemisphere 60 % of the area is made up of ocean and 40 % is covered by land, whereas only 20 % of the Southern Hemisphere is covered by land and 80 % is covered by ocean. Oceans cover roughly 70,8 % of the total area of earth and land masses cover 29,2 %, so these numbers are probably ok. Here’s an image from Wikipedia:

About 90 percent of the human population lives on the Northern Hemisphere – the combined human population of the entire Southern Hemisphere is smaller than the population of Europe.

4a. The Pacific Ocean covers a larger area than all land masses of Earth combined.

4b. The Atlantic Ocean covers as a very rough approximation the same area (106 mio. square kilometres) as the total land area of the Northern Hemisphere. It covers an area corresponding to more than 70 percent of the total land area of earth.

4c. The Indian Ocean covers 68,556,000 square kilometres, approximately the same area as Asia and North America combined.

4d. The average depth of the world oceans is about 3.8 kilometers (link).

5. I can’t copy the image, but go here for a really neat illustration of the surface elevation of the areas of Earth – I’m really annoyed I can’t copy this and put it in the post. Antarctica has by far the highest mean elevation of all continents. According to this source, the mean elevation of the continent is 2,286 m. Disregarding Antarctica (which can be considered somewhat an outlier because of the ice-thing), it seems that there’s a connection between the area of a continent and its mean elevation – i.e. the larger the area of the continent, the higher the elevation. Here’s a relevant paper.)

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October 9, 2011 Posted by US | data, demographics, knowledge sharing, science, wikipedia | Leave a Comment

Wikipedia articles of interest

1. Tuskegee syphilis experiment.

“The Tuskegee syphilis experiment[1] (also known as the Tuskegee syphilis study or Public Health Service syphilis study) was an infamous clinical study conducted between 1932 and 1972 in Tuskegee, Alabama by the U.S. Public Health Service to study the natural progression of untreated syphilis in poor, rural black men who thought they were receiving free health care from the U.S. government.[1]

The Public Health Service, working with the Tuskegee Institute, began the study in 1932. Investigators enrolled in the study a total of 600 impoverished, African-American sharecroppers from Macon County, Alabama; 399 who had previously contracted syphilis before the study began, and 201 without the disease. For participating in the study, the men were given free medical care, meals, and free burial insurance. They were never told they had syphilis, nor were they ever treated for it. According to the Centers for Disease Control, the men were told they were being treated for “bad blood,” a local term used to describe several illnesses, including syphilis, anemia and fatigue.

The 40-year study was controversial for reasons related to ethical standards; primarily because researchers knowingly failed to treat patients appropriately after the 1940s validation of penicillin as an effective cure for the disease they were studying. Revelation of study failures by a whistleblower led to major changes in U.S. law and regulation on the protection of participants in clinical studies. Now studies require informed consent (with exceptions possible for U.S. Federal agencies which can be kept secret by Executive Order[2]), communication of diagnosis, and accurate reporting of test results.[3]

By 1947, penicillin had become the standard treatment for syphilis. Choices available to the doctors involved in the study might have included treating all syphilitic subjects and closing the study, or splitting off a control group for testing with penicillin. Instead, the Tuskegee scientists continued the study without treating any participants and withholding penicillin and information about it from the patients. In addition, scientists prevented participants from accessing syphilis treatment programs available to others in the area.[4] The study continued, under numerous US Public Health Service supervisors, until 1972, when a leak to the press eventually resulted in its termination. The victims of the study included numerous men who died of syphilis, wives who contracted the disease, and children born with congenital syphilis.[5] [...]

By the end of the study in 1972, only 74 of the test subjects were alive. Of the original 399 men, 28 had died of syphilis, 100 were dead of related complications, 40 of their wives had been infected and 19 of their children were born with congenital syphilis.” [...]

“In October 2010 it was revealed that in Guatemala, Public Health Service doctors went even further. It was reported that from 1946 to 1948, American doctors deliberately infected prisoners, soldiers, and patients in a mental hospital with syphilis and, in some cases, gonorrhea, with the cooperation of some Guatemalan health ministries and officials. A total of 696 men and women were exposed to syphilis without the informed consent of the subjects. When the subjects contracted the disease they were given antibiotics though it is unclear if all infected parties were cured.[15]” (here’s a relevant link link to that story)

2. Containerization. File under: Stuff we don’t think about even though we probably should. A few quotes:

“As of 2009 approximately 90% of non-bulk cargo worldwide is moved by containers stacked on transport ships;[13] 26% of all container transhipment is carried out in China.[14] For example in 2009 there were 105,976,701 transhipments in China (both international and coastal; excluding Hong Kong), 21,040,096 in Hong Kong (which is listed separately), and only 34,299,572 in the United States. In 2005 some 18 million containers made over 200 million trips per year. [...]

However, few initially foresaw the extent of the influence of containerization on the shipping industry. In the 1950s Harvard University economist Benjamin Chinitz predicted that containerization would benefit New York by allowing it to ship its industrial goods more cheaply to the Southern United States than other areas, but did not anticipate that containerization might make it cheaper to import such goods from abroad. Most economic studies of containerization merely assumed that shipping companies would begin to replace older forms of transportation with containerization, but did not predict that the process of containerization itself would have a more direct influence on the choice of producers and increase the total volume of trade.[10]

The widespread use of ISO standard containers has driven modifications in other freight-moving standards, gradually forcing removable truck bodies or swap bodies into standard sizes and shapes (though without the strength needed to be stacked), and changing completely the worldwide use of freight pallets that fit into ISO containers or into commercial vehicles.

Improved cargo security is also an important benefit of containerization. The cargo is not visible to the casual viewer and thus is less likely to be stolen; the doors of the containers are usually sealed so that tampering is more evident. Some containers are fitted with electronic monitoring devices and can be remotely monitored for changes in air pressure, which happens when the doors are opened. This reduced the thefts that had long plagued the shipping industry.

Use of the same basic sizes of containers across the globe has lessened the problems caused by incompatible rail gauge sizes in different countries. The majority of the rail networks in the world operate on a 1,435 mm (4 ft 8 1⁄2 in) gauge track known as standard gauge, but many countries (such as Russia, India, Finland, and Lithuania) use broader gauges, while many others in Africa and South America use narrower gauges on their networks. The use of container trains in all these countries makes trans-shipment between different gauge trains easier.”

3. Praetorian Guard. These guys had a lot of power – the Roman Emperors: Caligula, Galba, Pertinax, Elagabalus, Balbinus, Pupienus and Aurelian were all simply murdered by the Praetorian Guard; some of the others also died more or less because of the actions of some of the members of the Guard. And of course lots of those emperors who didn’t get killed were in power more or less because the Guard did not disapprove too strongly.

4. Battle of Trafalgar.

5. Wheat leaf rust. “Wheat leaf rust, is fungal disease that effects wheat, barley and rye stems, leaves and grains. In temperate zones it is destructive on winter wheat because the pathogen overwinters. Infections can lead up to 20% yield loss – exacerbated by dying leaves which fertilize the fungus.”

Imagine the food price- and nutritional consequenses of a global 20 % reduction of wheat production over, say, a five year period. Or (worse), such a reduction in rice production. In an alternative universe, some child right now sits in a classroom with no knowledge of Hitler, because he’s spent the history lessons learning about the horrors of the great global outbreak of Claviceps purpurea in 1939.

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September 20, 2011 Posted by US | knowledge sharing, wikipedia | Leave a Comment

Some numbers

I spent a bit of time at Statistikbanken (Statbank Denmark) yesterday, below are some numbers from it that might be of interest. When you click the link you get to the front page of the site – now, if you look to the right there’s a small Union Jack which says ‘English’ if you hover over it. Click this and you get to the English version of the site. I don’t think all of the stuff at the Danish version of the site has been translated at the English link – but a lot of stuff has, so if you’re a foreigner curious about Denmark and the Danes, go take a look..

i. This part contains data from ‘KRHFU1: Befolkningens højeste fuldførte uddannelse (15-69 år) efter område, herkomst, uddannelse alder og køn’.

In 2010, when looking at the age segment of Danes who were 30-34 years old, 20494 Danish males and 22812 Danish females had as the highest achieved education level completed a ‘long-cycle higher education’ (I think this is the term they use in the English version of the data; in Danish it’s just ‘lang videregående uddannelse’. It corresponds to an education level above BA-level but below PhD-level, i.e. Master’s Degree or equivalent). Notice that more females than males at that age has completed this level of education. This is also true after you correct for the fact that there are more males than females in that age segment of the population; in total, there were 177078 males and 176291 females in that age segment of the Danish population. In terms of percentages of the total population in the specific age segment, 11,6 % of the males and 12,9 % of the females at the age of 30-34 had completed a long-cycle higher education in 2010 – the gender difference is about 10 percent.

Now, a funny thing happens when you compare these numbers to the age segment of Danes at the age of 65-69 (people who’ve just retired). In that sample, 9655 males and 3818 females have a long-cycle higher education – out of 146029
males and 152812 females. In that sample, 6,6 % of the males and just 2,5 % of the females have a long-cycle higher education – males in that age group are more than 2,5 times as likely to have a high education than females.

How does it look when you include the age groups in between those two? Like this:

More females than males get a long education today and it’s been that way for at least 10-15 years.

ii. This part contains data from ‘Folketal pr. 1. januar efter tid, alder og køn’ and ‘KM6: Befolkningen 1 januar efter kommune, køn, alder og folkekirkemedlemsskab’

(red: females, blue: males. The x-axis is age, the y-axis is the percentage of each age group who are members of Folkekirken)

So I took out the number of male and female members of Folkekirken at the ages of 1-80 and divided by the total number of Danes in the specific age-group – this gives a measure of how big a percentage of each age group is a member of Folkekirken (Danish National Church). It seems that there are some age cycles here. I did a quick logical test in Excel to get an overview of how the membership rate changes from age group to age group. At the ages of 1-15 years, membership grows ‘every year’ (2-year olds are more likely to be members than 1-year olds, ect.). At the age group of people 18-27 years old, membership drops ‘every year’. Between 30-43 it pretty much grows every year again, then it stabilizes around the new level. For people above the age of 55, it pretty much grows every year again. I decided to not include people above the age of 80 because nothing much of interest happens there; as should be clear from the graph this age segment has by far the highest membership rates and more than 9 out of 10 are members. Remember when interpreting the relatively low membership of children to the left of the graph and the membership growth of the 1-15 years old that part of this is probably because of the relatively higher fertility of Muslim immigrants (as opposed to fewer atheist children).

iii. This part contains data from ‘FAM55N: Husstande pr. 1. januar efter kommune/region, husstandstype og husstandsstørrelse’. Every time some econ blog posts something about the household income development over time (like this one) I also see a commenter asking: ‘but what about household size?’ What I very rarely see is a commenter linking to actual data on household size. This puzzles me every time, because at least in Denmark that kind of data actually isn’t all that hard to get your hands on. Here’s a quick run from Statistikbanken:

I omitted some of the classes because otherwise it quickly gets very messy and they don’t add much to the big picture anyway, this is why the numbers don’t quite add up to the total population – but the table does include far most Danes (the 2011 numbers include 4,92 million people, the 1986 numbers 4,42 million people). The number of single person households with one male or one female living alone has increased somewhat. If you wanted to do it completely right, you’d add all the omitted classes as well before making the calculation, but in terms of the people in the sample (which covers ~ 90% of all Danes) the percentage of people living in single person households went up from 16,2 % to 20,3 %. In terms of the percentage of all households that are single person households, the number is of course much higher. In 1986, 35,6 % of all households (in the sample) were single person households, in 2011 it was 41,5 %. The number has gone up, but less than I’d thought.

I found it interesting that the number of households with a married couple and 3-4 inhabitants altogether (the most likely constellation is a married couple plus 1 or 2 children) has decreased significantly and movement from ‘married couples’ to ‘other couples’ does not explain all of it. Is the driver an increase in the divorce rate or lower fertility rate? I don’t know.

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September 14, 2011 Posted by US | data, demographics, economics, education, knowledge sharing | Leave a Comment

The French Revolution and The Napoleonic Wars

Wikipedia has some relevant stuff here, here and here. Note that if you’re interested in the history of France, Wikipedia has a ‘History of France series’ with lots of other stuff (see the sidebar in the article on the French Revolution).

Khan Academy has a lot of good stuff on the subject too, I’ve decided to post some of the videos here:

A comment before I move on to the Napoleonic Wars: Something I didn’t know anything about was that even though the Bastille did work as a political prison at the time, the prisoners really were nowhere near the main reason for storming it – the protesters stormed it to get hold of the weapons stored inside:

“On the morning of 14 July 1789, the city of Paris was in a state of alarm. The demonstrators, led by Amaria Cahila of the third estate in France, had earlier stormed the Hôtel des Invalides to gather arms (29,000 to 32,000 muskets, but without powder or shot), and were mainly seeking to acquire the large quantities of arms and ammunition stored at the Bastille. On the 14th there were over 13,600 kilograms (30,000 lb) of gunpowder stored there.

At this point, the Bastille was nearly empty of prisoners, housing only seven old men annoyed by all the disturbance:[4] four forgers, two “lunatics” and one “deviant” aristocrat, the comte de Solages (the Marquis de Sade had been transferred out ten days earlier). The cost of maintaining a medieval fortress and garrison for so limited a purpose had led to a decision being taken to close it, shortly before the disturbances began. It was, however, a symbol of royal tyranny.”