Econstudentlog

Wikipedia articles of interest

i. Huia (featured).

“The Huia (Māori: [ˈhʉia]; Heteralocha acutirostris) was the largest species of New Zealand wattlebird and was endemic to the North Island of New Zealand.”

What they looked like:

800px-Keulemans_Huias

“Even though the Huia is frequently mentioned in biology and ornithology textbooks because of this striking dimorphism, not much is known about its biology; it was little studied before it was driven to extinction. The Huia is one of New Zealand’s best known extinct birds because of its bill shape, its sheer beauty and special place in Māori culture and oral tradition. […]

The Huia had no fear of people; females allowed themselves to be handled on the nest,[8] and birds could easily be captured by hand.[11] […]

The Huia was found throughout the North Island before humans arrived in New Zealand. The Māori arrived around 800 years ago, and by the arrival of European settlers in the 1840s, habitat destruction and hunting had reduced the bird’s range to the southern North Island.[13] However, Māori hunting pressures on the Huia were limited to some extent by traditional protocols. The hunting season was from May to July when the bird’s plumage was in prime condition, while a rāhui (hunting ban) was enforced in spring and summer.[15] It was not until European settlement that the Huia’s numbers began to decline severely, due mainly to two well-documented factors: widespread deforestation and overhunting. […]

Habitat destruction and the predations of introduced species were problems faced by all New Zealand birds, but in addition the Huia faced massive pressure from hunting. Due to its pronounced sexual dimorphism and its beauty, Huia were sought after as mounted specimens by wealthy collectors in Europe[42] and by museums all over the world.[15][20] These individuals and institutions were willing to pay large sums of money for good specimens, and the overseas demand created a strong financial incentive for hunters in New Zealand.[42]

ii. British colonization of the Americas. Not very detailed, but this article is a good place to start if one wants to read about the various colonies; it has a lot of links.

iii. Iron Dome.

Iron Dome (Hebrew: כִּפַּת בַּרְזֶל, kipat barzel) also known as “Iron Cap[6] is a mobile all-weather air defense system[5] developed by Rafael Advanced Defense Systems.[4] It is a missile system designed to intercept and destroy short-range rockets and artillery shells fired from distances of 4 to 70 kilometers away and whose trajectory would take them to a populated area.[7][8] […] The system, created as a defensive countermeasure to the rocket threat against Israel‘s civilian population on its northern and southern borders, uses technology first employed in Rafael’s SPYDER system. Iron Dome was declared operational and initially deployed on 27 March 2011 near Beersheba.[10] On 7 April 2011, the system successfully intercepted a Grad rocket launched from Gaza for the first time.[11] On 10 March 2012, The Jerusalem Post reported that the system shot down 90% of rockets launched from Gaza that would have landed in populated areas.[8] By November 2012, it had intercepted 400+ rockets.[12][13] Based on this success, Defense reporter Mark Thompson estimates that Iron Dome is the most effective and most tested missile shield in existence.[14]

The Iron Dome system is also effective against aircraft up to an altitude of 32,800 ft (10,000 m).[15] […]

800px-Iron_Dome_near_Sderot

During the 2006 Second Lebanon War, approximately 4,000 Hezbollah-fired rockets (the great majority of which were short-range Katyusha rockets) landed in northern Israel, including on Haifa, the country’s third largest city. The massive rocket barrage killed 44 Israeli civilians[16] and caused some 250,000 Israeli citizens to evacuate and relocate to other parts of Israel while an estimated 1,000,000 Israelis were confined in or near shelters during the conflict.[17]

To the south, more than 4,000 rockets and 4,000 mortar bombs were fired into Israel from Gaza between 2000 and 2008, principally by Hamas. Almost all of the rockets fired were Qassams launched by 122 mm Grad launchers smuggled into the Gaza Strip, giving longer range than other launch methods. Nearly 1,000,000 Israelis living in the south are within rocket range, posing a serious security threat to the country and its citizens.[18]

In February 2007, Defense Minister Amir Peretz selected Iron Dome as Israel’s defensive solution to this short-range rocket threat.[19] […]

In November 2012, during Operation Pillar of Defense, the Iron Dome’s effectiveness was estimated by Israeli officials at between 75 and 95 percent.[88] According to Israeli officials, of the approximately 1,000 missiles and rockets fired into Israel by Hamas from the beginning of Operation Pillar of Defense up to November 17, 2012, Iron Dome identified two thirds as not posing a threat and intercepted 90 percent of the remaining 300.[89] During this period the only Israeli casualties were three individuals killed in missile attacks after a malfunction of the Iron Dome system.[90]

In comparison with other air defense systems, the effectiveness rate of Iron Dome is very high.[88]

iv. Evolution of cetaceans (whales and dolphins). They’re a lot ‘younger’ than I thought.

v. Curiosity rover.

PIA16239_High-Resolution_Self-Portrait_by_Curiosity_Rover_Arm_Camera

This is an actual (composite) picture of a robot on another planet. At this moment it is walking around doing scientific experiments. On another planet. I’ll say it again: Living in the 21st century is awesome.

vi. Halting Problem.

“In computability theory, the halting problem can be stated as follows: “Given a description of an arbitrary computer program, decide whether the program finishes running or continues to run forever“. This is equivalent to the problem of deciding, given a program and an input, whether the program will eventually halt when run with that input, or will run forever.

Alan Turing proved in 1936 that a general algorithm to solve the halting problem for all possible program-input pairs cannot exist. A key part of the proof was a mathematical definition of a computer and program, what became known as a Turing machine; the halting problem is undecidable over Turing machines. It is one of the first examples of a decision problem. […]

The halting problem is a decision problem about properties of computer programs on a fixed Turing-complete model of computation, i.e. all programs that can be written in some given programming language that is general enough to be equivalent to a Turing machine. The problem is to determine, given a program and an input to the program, whether the program will eventually halt when run with that input. In this abstract framework, there are no resource limitations on the amount of memory or time required for the program’s execution; it can take arbitrarily long, and use arbitrarily much storage space, before halting. The question is simply whether the given program will ever halt on a particular input. […]

One approach to the problem might be to run the program for some number of steps and check if it halts. But if the program does not halt, it is unknown whether the program will eventually halt or run forever.

Turing proved there cannot exist an algorithm which will always correctly decide whether, for a given arbitrary program and its input, determine the program halts when run with that input; the essence of Turing’s proof is that any such algorithm can be made to contradict itself, and therefore cannot be correct. […]

The halting problem is historically important because it was one of the first problems to be proved undecidable.”

vii. Fetal Alcohol Syndrome.

Fetal alcohol syndrome (FAS) is a pattern of mental and physical defects that can develop in a fetus in association with high levels of alcohol consumption during pregnancy. […]

Alcohol crosses the placental barrier and can stunt fetal growth or weight, create distinctive facial stigmata, damage neurons and brain structures, which can result in psychological or behavioral problems, and cause other physical damage.[6][7][8] Surveys found that in the United States, 10–15% of pregnant women report having recently drunk alcohol, and up to 30% drink alcohol at some point during pregnancy.[9][10][11]

The main effect of FAS is permanent central nervous system damage, especially to the brain. Developing brain cells and structures can be malformed or have development interrupted by prenatal alcohol exposure; this can create an array of primary cognitive and functional disabilities (including poor memory, attention deficits, impulsive behavior, and poor cause-effect reasoning) as well as secondary disabilities (for example, predispositions to mental health problems and drug addiction).[8][12] Alcohol exposure presents a risk of fetal brain damage at any point during a pregnancy, since brain development is ongoing throughout pregnancy.[13]

Fetal alcohol exposure is the leading known cause of mental retardation in the Western world.[14][15] In the United States and Europe, the FAS prevalence rate is estimated to be between 0.2-2 in every 1000 live births.[16][17] FAS should not be confused with Fetal Alcohol Spectrum Disorders (FASD), a condition which describes a continuum of permanent birth defects caused by maternal consumption of alcohol during pregnancy, which includes FAS, as well as other disorders, and which affects about 1% of live births in the US.[18][19][20][21] The lifetime medical and social costs of FAS are estimated to be as high as US$800,000 per child born with the disorder.[22]

That’s a US estimate, but I think a Danish one would be within the same order of magnitude. Imagine how the incentives of expectant mothers would change if we fined females who gave birth to a child with FAS, letting the fine be some fraction of the total estimated social costs. And remind me again why we do not do this?

December 15, 2012 - Posted by | biology, evolution, history, mathematics, medicine, wikipedia

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