Econstudentlog

Wikipedia articles of interest

1. Trophic level.

“The trophic level of an organism is the position it occupies in a food chain. The word trophic derives from the Greek τροφή (trophē) referring to food or feeding. A food chain represents a succession of organisms that eat another organism and are, in turn, eaten themselves. The number of steps an organism is from the start of the chain is a measure of its trophic level. Food chains start at trophic level 1 with primary producers such as plants, move to herbivores at level 2, predators at level 3 and typically finish with carnivores or apex predators at level 4 or 5. The path along the chain can form a one-way flow, or a food “web.” Ecological communities with higher biodiversity form more complex trophic paths. […]

The three basic ways organisms get food are as producers, consumers and decomposers.

*Producers (autotrophs) are typically plants or algae. Plants and algae do not usually eat other organisms, but pull nutrients from the soil or the ocean and manufacture their own food using photosynthesis. For this reason, they are called primary producers. In this way, it is energy from the sun that usually powers the base of the food chain.[1] An exception occurs in deep-sea hydrothermal ecosystems, where there is no sunlight. Here primary producers manufacture food through a process called chemosynthesis.[2]

*Consumers (heterotrophs) are animals which cannot manufacture their own food and need to consume other organisms. Animal that eat primary producers (like plants) are called herbivores. Animals that eat other animals are called carnivores, and animals that eat both plant and other animals are called omnivores.

*Decomposers (detritivores) break down dead plant and animal material and wastes and release it again as energy and nutrients into the ecosystem for recycling. Decomposers, such as bacteria and fungi (mushrooms), feed on waste and dead matter, converting it into inorganic chemicals that can be recycled as mineral nutrients for plants to use again.”

2. Charles de Gaulle.

3. Pareto distribution. You need to know a bit of statistics to make sense of this article.

4. Red Barn Murder.

“The Red Barn Murder was a notorious murder committed in Polstead, Suffolk, England, in 1827. A young woman, Maria Marten, was shot dead by her lover, William Corder. The two had arranged to meet at the Red Barn, a local landmark, before eloping to Ipswich. Maria was never heard from again. Corder fled the scene and although he sent Marten’s family letters claiming she was in good health, her body was later discovered buried in the barn after her stepmother spoke of having dreamt about the murder.

Corder was tracked down in London, where he had married and started a new life. He was brought back to Suffolk, and after a well-publicised trial, found guilty of murder. He was hanged in Bury St Edmunds in 1828; a huge crowd witnessed Corder’s execution. The story provoked numerous articles in the newspapers, and songs and plays. The village where the crime had taken place became a tourist attraction and the barn was stripped by souvenir hunters.”

5. SN 1987A. A little knowledge makes everything a little cooler, so of course I had to link to this after reading this awesome abstruse goose comic.

6. Structural history of the Roman military.

“The structural history of the Roman military concerns the major transformations in the organization and constitution of ancient Rome’s armed forces, “the most effective and long-lived military institution known to history.”[1] From its origins around 800 BC to its final dissolution in AD 476 with the demise of the Western Roman Empire, Rome’s military organization underwent substantial structural change. At the highest level of structure, the forces were split into the Roman army and the Roman navy, although these two branches were less distinct than in many modern national defense forces. Within the top levels of both army and navy, structural changes occurred as a result of both positive military reform and organic structural evolution. These changes can be divided into four distinct phases.

Phase I
*The army was derived from obligatory annual military service levied on the citizenry, as part of their duty to the state. During this period, the Roman army would wage seasonal campaigns against largely local adversaries.

Phase II
*As the extent of the territories falling under Roman control expanded and the size of the forces increased, the soldiery gradually became salaried professionals. As a consequence, military service at the lower (non-salaried) levels became progressively longer-term. Roman military units of the period were largely homogeneous and highly regulated. The army consisted of units of citizen infantry known as legions (Latin: legiones) as well as non-legionary allied troops known as auxilia. The latter were most commonly called upon to provide light infantry, logistical, or cavalry support.

Phase III
*At the height of the Roman Empire’s power, forces were tasked with manning and securing the borders of the vast provinces which had been brought under Roman control. Serious strategic threats were less common in this period and emphasis was placed on preserving gained territory. The army underwent changes in response to these new needs and became more dependent on fixed garrisons than on march-camps and continuous field operations.

Phase IV
*As Rome began to struggle to keep control over its sprawling territories, military service continued to be salaried and professional for Rome’s regular troops. However, the trend of employing allied or mercenary elements was expanded to such an extent that, these troops came to represent a substantial proportion of the armed forces. At the same time, the uniformity of structure found in Rome’s earlier military disappeared. Soldiery of the era ranged from lightly armed mounted archers to heavy infantry, in regiments of varying size and quality. This was accompanied by a trend in the late empire of an increasing predominance of cavalry rather than infantry troops, as well as a requirement for more mobile operations.” (the (featured) article has much more + plenty of links)

7. Megalodon.

“The megalodon (play /ˈmɛɡələdɒn/ MEG-ə-lə-don; meaning “big tooth”, from Greek μέγας (mega, “big”) and ὀδούς (odon, “tooth”)) is an extinct species of shark that lived roughly from 28 to 1.5 million years ago, during the Cenozoic Era (late Oligocene to early Pleistocene).

The taxonomic assignment of C. megalodon has been debated for nearly a century, and is still under dispute with two major interpretations; Carcharodon megalodon (under family Lamnidae) or Carcharocles megalodon (under family Otodontidae).[1] Consequently, the scientific name of this species has been commonly abbreviated to C. megalodon in literature.

C. megalodon is regarded as one of the largest and most powerful predators in vertebrate history.[2] C. megalodon likely had a profound impact on structuring of the marine communities. Fossil remains indicate that this giant shark reached a total length (TL) of more than 16 metres (52 ft),[1] and also affirm that it had a cosmopolitan distribution.[1] Scientists suggest that C. megalodon looked like a stockier version of the great white shark, Carcharodon carcharias, in life. […]

Somewhat related: In case you guys haven’t already heard about this, the remains of a huge feathered dinosaur was found in China recently. If you’re curious, you can read more here or here.

April 7, 2012 - Posted by | astronomy, biology, history, Paleontology, statistics, wikipedia

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