Tent

A tent  pronunciation  is a shelter consisting of sheets of fabric or other material draped over, attached to a frame of poles or attached to a supporting rope. While smaller tents may be free-standing or attached to the ground, large tents are usually anchored using guy ropes tied to stakes or tent pegs. First used as portable homes by nomadic peoples, tents are now more often used for recreational camping and temporary shelters.

Tents range in size from "bivouac" structures, just big enough for one person to sleep in, up to huge circus tents capable of seating thousands of people. The bulk of this article is concerned with tents used for recreational camping which have sleeping space for one to ten people. Larger tents are discussed in a separate section below.

Tents for recreational camping fall into two categories. Tents intended to be carried by backpackers are the smallest and lightest type. Small tents may be sufficiently light that they can be carried for long distances on a touring bicycle, a boat, or when backpacking.

Tetanospasmin

Tetanus toxin is an extremely potent neurotoxin produced by the vegetative cell of Clostridium tetani in anaerobic conditions, causing tetanus. It has no known function for clostridia in the soil environment where they are normally encountered. It is also called spasmogenic toxin, or TeNT. The LD₅₀ of this toxin has been measured to be approximately 1 ng/kg, making it second only to Botulinum toxin as the deadliest toxin in the world. However, these tests are conducted solely on mice which may react to the toxin differently from humans and other animals.

C. tetani also produces the exotoxin tetanolysin, a hemolysin, that causes destruction of tissues.

Distribution

Tetanus toxin spreads through tissue spaces into the lymphatic and vascular systems. It enters the nervous system at the neuromuscular junctions and migrates through nerve trunks and into the central nervous system (CNS) by retrograde axonal transport by using dyneins.

Structure

The tetanus toxin protein has a molecular weight of 150kDa. It is translated from the TetX gene as one protein which is subsequently cleaved into two parts: a 100kDa heavy or B-chain and a 50kDa light or A-chain. The chains are connected by a disulfide bond.

BPM 37093

BPM 37093 (V886 Centauri) is a variable white dwarf star of the DAV, or ZZ Ceti, type, with a hydrogen atmosphere and an unusually high mass of approximately 1.1 times the Sun's. It is about 50 light-years from Earth, in the constellation Centaurus, and vibrates; these pulsations cause its luminosity to vary. Like other white dwarfs, BPM 37093 is thought to be composed primarily of carbon and oxygen, which are created by thermonuclear fusion of helium nuclei in the triple-alpha process.

In the 1960s, it was predicted that as a white dwarf cools, its material should crystallize, starting at the center. When a star pulsates, observing its pulsations gives information about its structure. BPM 37093 was first observed to be a pulsating variable in 1992, and in 1995 it was pointed out that this yielded a potential test of the crystallization theory. In 2004, Antonio Kanaan and a team of researchers of the Whole Earth Telescope estimated, on the basis of these asteroseismological observations, that approximately 90% of the mass of BPM 37093 had crystallized. Other work gives a crystallized mass fraction of between 32% and 82%. Any of these estimates would result in a total crystalline mass in excess of 5×10²⁹ kilograms.

Esox

Esox is a genus of freshwater fish, the only living genus in the family Esocidae—the esocids which were endemic to North America and Eurasia during the Paleogene through present.

The species of this genus are known as pike and pickerel. The type species is E. lucius, the northern pike.

The big pike species are native to the Palearctic and Nearctic ecozones, ranging across northern North America and from Western Europe to Siberia in Eurasia.

Pikes have the elongated, torpedo-like form of predatory fishes, with sharply pointed heads and sharp teeth. Their coloration is typically grey-green with a mottled or spotted appearance with stripes along their backs, providing camouflage among weeds. Individual pike marking patterns are unique, like fingerprints. Pike can grow to a maximum recorded length of 1.83 m (6 ft), reaching a maximum recorded weight of 35 kg (77 lb).

Species

There currently seven recognized species in this genus:

Dorothea Weber

Dorothea Weber was a 190 GRT three-masted Schooner that was built in 1922 as the barge Lucy by J Oelkers, Hamburg. She was later renamed Midgard I, Midgard IV and then Elisabeth before a sale in 1935 saw her fitted with a diesel engine and renamed Dorothea Weber. She was seized by the Allies in May 1945 at Guernsey, passed to the Ministry of War Transport (MoWT) and renamed Empire Cononley.

In 1947, she was sold into merchant service and renamed Coverack. A further sale in 1953 saw her renamed River Witham. She served until 1959 when she ran aground off Lowestoft. Although she was refloated, she capsized and sank off the Inner Dowsing Light Vessel.

Description

The ship was built by J Oelkers, Hamburg. She was launched in 1922.

The ship was 105 feet 7 inches (32.18 m) long, with a beam of 24 feet 9 inches (7.54 m) and a depth of 8 feet 1 inch (2.46 m). The ship had a GRT of 190 and a NRT of 100.

As built, the ship was propelled by sails alone. A diesel engine was fitted in 1935 and this was replaced by another engine in 1951.