The Phoronida, or horseshoe worms, are a small phylum of marine animals. There are twenty species, in two genera. They are part of the Brachiozoa, which also includes the brachiopods.
Phoronids are worm-shaped, but with a gut that loops and exits the body near the mouth. That explains the name 'horseshoe worms'. They are found in all oceans and seas (except the polar seas), and all species have wide geographical ranges.
They occur at depths up to 400 metres, but mainly between 0 to 70 metres. The life span is thought to be about a year. The adults are tube worms, and secrete chitinous tubes in which they live. These tubes can be buried in the mud or sand or rest on the surface of a rocky substrate. If on rocks, they may live in colonies with their tubes become twisted around each other for support. Some species can dissolve away holes in rocks such as limestone, calcareous seashells or even cement piers; they then live in these holes which they line with their secreted tubes.
They feed using a lophophore, a ciliated structure that surrounds the mouth. Together with the Bryozoa and Brachiopoda, the phoronids belong to the lophophorates, sometimes treated as a single phylum.
Though they are normally long, up to 50cm (30 in). Phoronids are normally very thin.
The digestive tract of Phoronids consists of a short oesophagus which leads into a spherical stomach and then into the intestines which end in the anus. Phoronids have a simple blood system of one descending artery and ascending vein linked by a network of fine capillaries. There are also blood vessels into each of the tentacles. The blood is colourless but contains corpuscles with a haemoglobin-like pigment that helps to carry oxygen.
The nervous system is mainly composed by the nervous ganglion between mouth and anus, a ring nerve at the basis of the lophophore, one or two giant nerve fibres which issue from the ganglion and extend along the body wall. There are two tubular excretory organs, which discharge to the exterior via nephridiopores, on the anal papilla.
Phoronids may be hermaphrodites or single sexed, and may also reproduce asexually. Gametes are released through the nephridia. Fertilisation is probably internal. Phoronids follow one of two types of reproductive strategy. Some species, such as "Phoronis ovalis", lay only a few (12–25) large eggs which have a lot of yolk. These eggs are brooded within the adult's tube, they are released only when they have hatched. The second strategy is to lay a much larger number (up to 500) of smaller eggs. These eggs are released as soon as they are fertilised. They hatch a few days later into what is called an 'actinotrocha' larvae. The larvae undergo a planktonic development for 2–3 weeks, and settle after about 20 days. Metamorphosis is 'catastrophic', occurring in less than 30 minutes and leading to a slender young phoronid.
Phoronids can regenerate the lophophore if it becomes damaged, in fact "Phoronis ovalis" voluntarily loses its lophophore in order to lay its eggs. Once the eggs are laid the animal grows a new lophophore.
Phoronids are suspension-feeders. They move their lophophores into the prevailing water current. Food particles in the water current are trapped in a stream of mucous that travels along the tentacles until it reaches the oral ring. There it is drawn into the mouth and then on into the digestive tract. Direct uptake of amino acids through the epidermis also occurs.
The fossil record of phoronids is poor. There are borings dating back to the Devonian which have been attributed to phoronids. "Iotuba chengjiangensis", a form known from only three specimens in the Lower Cambrian, has been interpreted as a phoronid because it appears to have had a U-shaped gut and was tentaculated. Phoronids may be related to the common but mysterious tubular fossils known as hederellids.
Shanghai International Circuit
The Shanghai International Circuit is a Chinese motor racing venue. It is in the district of Jiading near Shanghai in the People's Republic of China. It was the venue of the first Formula One Chinese Grand Prix on 26 September 2004.
The circuit costing about $450 million (USD). It was paid for by a government-funded joint-venture company. This company was made up of the Shanghai Juss Corporation, Shanghai National Property Management Co Ltd, and Shanghai Jia'an Investment and Development Co Ltd. Architectural and design experts began visiting the site by April 2003. The site was transformed from swampland to an international racetrack in 18 months. A team of 3000 worked around the clock to finish the construction.
Other events held at the circuit include a round of the MotoGP world championship, the Australian-based V8 Supercar championship, and also the final round of the A1 Grand Prix in 2006 and 2007.
The 2008 MotoGP race was the last one at Shanghai International Circuit. The FIM didn't select the circuit for 2009 because of overcrowding problems.
Like many new Formula One circuits, Shanghai International Circuit was designed by Hermann Tilke. It features his trademark track feature: a long back straight followed by a hairpin turn. Current-generation F1 cars can easily exceed on the long straight between corners 13 and 14. The track layout was inspired from the Chinese character shang (上). Shang is the first character in the name of the city Shanghai, and means "above" or "ascend".
<nowiki>*</nowiki>"Intermediate circuit (4.600 km/2.858 mi)"
Endeavour River National Park
The Endeavour River National Park is just north of Cooktown, Queensland, Australia. It protects the north banks of the Endeavour River. Both the river and the park are named after Captain James Cook's ship, HM Bark Endeavour. The ship was repaired in the river in 1770 after being damaged by coral on the Great Barrier Reef. Most of the park can only be reached by boat. There are no facilities in the park, and people are not allowed to camp there. The park covers an area of about 2400 hectares. It is next to the Cairns Marine Park and the Great Barrier Reef Marine Park.
The Endeavour River protects a number of different habitats including, coastal dunes, fresh water wetlands, river estuary, mangrove forests, heathland and tropical woodlands.
Nobuko Yoshiya
Yoshiya was born in Niigata Prefecture, but grew up in the cities of Mooka and Tochigi, in Tochigi Prefecture. Her father was in the public service, so her family often moved. She was the only daughter and youngest child of her family. Both, her mother and her father, came from samurai families. She started writing when she was in her teens, although before this she had developed a love for writing which sapped her time for learning domestic skills from her mother.
Radioisotope heater unit
A radioisotope heater unit is a device that provides heat from the breakdown of radioactive material. Radioactive material is added to a container within the heater. Because the material is unstable, it breaks down, releasing energy as heat. The heater may be packaged with a thermocouple to make electricity.
Circuit de Catalunya
The Circuit de Catalunya is a racetrack in Montmeló, to the north of Barcelona, Catalonia. It is home to the Formula One Spanish Grand Prix and the motorcycle Catalonia Grand Prix. With long straights and a variety of corners, the Circuit de Catalunya is seen as an all-rounder circuit. It is often used for off-season testing.
The Circuit de Catalunya was built in 1991. It was planned to host its first race in 1992 to go with the Olympic Games. The Olympic Games were scheduled to take place in Barcelona. The circuit is often referred to as 'Barcelona' in the racing community, even though it is located in Montmeló. The Circuit de Catalunya should not be confused with the Montjuïc circuit, which hosted the Spanish Grand Prix four times between 1969 and 1975. Unlike the Circuit de Catalunya, Montjuïc circuit is actually located within the city of Barcelona.