Biodegradation

Biodegradation is the process by which organic substances are broken down by the enzymes produced by living organisms. The term is often used in relation to ecology, waste management and environmental remediation (bioremediation). Organic material can be degraded aerobically, with oxygen, or anaerobically, without oxygen. A term related to biodegradation is biomineralisation, in which organic matter is converted into minerals. Biosurfactant, an extracellular surfactant secreted by microorganism enhances the biodegradation process.

Biodegradable matter is generally organic material such as plant and animal matter and other substances originating from living organisms, or artificial materials that are similar enough to plant and animal matter to be put to use by microorganisms. Some microorganisms have the astonishing, naturally occurring, microbial catabolic diversity to degrade, transform or accumulate a huge range of compounds including hydrocarbons (e.g. oil), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical substances, radionuclides and metals. Major methodological breakthroughs in microbial biodegradation have enabled detailed genomic, metagenomic, proteomic, bioinformatic and other high-throughput analyses of environmentally relevant microorganisms providing unprecedented insights into key biodegradative pathways and the ability of microorganisms to adapt to changing environmental conditions.

Vicuña

The vicuña (Vicugna vicugna) or vicugna is one of two wild South American camelids, along with the guanaco, which live in the high alpine areas of the Andes. It is a relative of the llama, and is now believed to be the wild ancestor of domesticated alpacas, which are raised for their fiber. Vicuñas produce small amounts of extremely fine wool, which is very expensive because the animal can only be shorn every 3 years. When knitted together, the product of the vicuña's fur is very soft and warm. It is understood that the Inca raised vicuñas for their wool, and that it was against the law for any but royalty to wear vicuña garments.

Both under the rule of the Inca and today, vicuñas have been protected by law. Before being declared endangered in 1974, only about 6,000 animals were left. Today, the vicuña population has recovered to about 125,000, and while conservation organizations have reduced its level of threat, they still call for active conservation programs to protect population levels from poaching, habitat loss, and other threats.

Pacific Ocean

• Arafura Sea
• Banda Sea
• Bering Sea
• Bismarck Sea
• Bohai Sea
• Bohol Sea (Mindanao Sea)
• Camotes Sea
• Celebes Sea
• Ceram Sea
• Chilean Sea
• Coral Sea
• East China Sea
• Flores Sea
• Gulf of Alaska
• Gulf of California (Sea of Cortés)
• Gulf of Carpentaria
• Gulf of Thailand
• Halmahera Sea
• Java Sea
• Koro Sea
• Molucca Sea
• Philippine Sea
• Salish Sea
• Savu Sea
• Sea of Japan
• Sea of Okhotsk
• Seto Inland Sea
• Solomon Sea
• South China Sea
• Sulu Sea
• Tasman Sea
• Yellow Sea

Silk

Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from cocoons made by the larvae of the mulberry silkworm Bombyx mori reared in captivity (sericulture). The shimmering appearance for which silk is prized comes from the fibers' triangular prism-like structure which allows silk cloth to refract incoming light at different angles.

"Wild silks" are produced by caterpillars other than the mulberry silkworm and can be artificially cultivated. A variety of wild silks have been known and used in China, South Asia, and Europe since early times, but the scale of production was always far smaller than that of cultivated silks. They differ from the domesticated varieties in color and texture, and cocoons gathered in the wild usually have been damaged by the emerging moth before the cocoons are gathered, so the silk thread that makes up the cocoon has been torn into shorter lengths. Commercially reared silkworm pupae are killed by dipping them in boiling water before the adult moths emerge, or by piercing them with a needle, allowing the whole cocoon to be unraveled as one continuous thread. This permits a much stronger cloth to be woven from the silk. Wild silks also tend to be more difficult to dye than silk from the cultivated silkworm.

There is some evidence that small quantities of wild silk were already being produced in the Mediterranean area and the Middle East by the time the stronger, cultivated silk from China began to be imported (Hill 2003, Appendix C).

Silks are produced by several other insects, but only the silk of moth caterpillars has been used for textile manufacture. There has been some research into other silks, which differ at the molecular level. Silks are mainly produced by the larvae of insects that complete metamorphosis, but also by some adult insects such as webspinners. Silk production is especially common in the Hymenoptera (bees, wasps, and ants), and is sometimes used in nest construction. Other types of arthropod produce silk, most notably various arachnids such as spiders (see spider silk).

Manicouagan crater

The Manicouagan Crater, located at [show location on an interactive map] 51°23′N 68°42′W / 51.383, -68.7Coordinates: [show location on an interactive map] 51°23′N 68°42′W / 51.383, -68.7 in northern Canada, about 300 km (190 mi) north of the city of Baie-Comeau, is one of the oldest known impact craters. It is thought to have been caused by the impact of a 5 km (3.1 mi) diameter asteroid about 214 million years ago (Triassic period), and may be associated with the end-Carnian extinction event.

The crater is a multiple-ring structure about 100 km (62 mi), with its 70 km (43 mi) diameter inner ring its most prominent feature; it contains a 70 km (43 mi) diameter annular lake, the Manicouagan Reservoir, surrounding an inner plateau.