Due to the practice of building in stone on the virtually tree-less islands, Shetland is extremely rich in physical remains of all these periods, though Shetland is less rich in material remains than Orkney.
The artifacts of all the eras of Shetland's past can be studied at the newly built (2007) Shetland Museum in Lerwick.
Salt evaporation pond
A Salt evaporation pond (or saltern pond) is a man-made shallow pond. Usually it is located near the sea. The ponds can be filled with salt water. The water is then left to evaporate. The salt is left behind, and can be harvested. Such ponds also provide a habitat for several kinds of animals. Most of these animals are birds.
The color tells how much salt there is left in the water. Green colors come from special algae. These algae are there in low to mid salinity ponds (ponds with little salt in the water). In middle to high salinity ponds, an alga called Dunaliella salina shifts the color to red. Millions of tiny brine shrimp create an orange cast in mid-salinity ponds. Other bacteria such as Stichococcus also contribute tints. These colors are especially interesting to airplane passengers or astronauts passing above due to their somewhat artistic formations of shape and color.
Salinity
Salinity is a scientific term. Scientists use it to tell how much salt there is in water. Salinity is measured by the amount of sodium chloride found in 1,000 grams of water, if there is 1 gram of sodium chloride in 1,000 grams of water solution it is 1 part per thousand. This is written as 1‰.
Food preservation
Food preservation is about the ways and means which help to preserve food. Food spoils from bacteria if it is not treated. For thousands of years, humans have used methods of preserving food, so that they can store food to eat later. The simplest methods of preserving food, such as drying strips of fish or meat in the hot sun have been used for thousands of years, and they are still used today by indigenous peoples. The other ancient method is to use salt, and often drying and salting are done together.
Food is spoiled because microorganisms change it. There are five basic techniques which make food last longer:
Usually several of the techniques are combined.
Common ways of preserving food are:
Many common methods use several of these approaches at the same time. For example, pickles preserved in a jar are heated then put in a mixture of vinegar and brine. Fruit jams and jellies are heated and mixed with a large amount of sugar. Some preserved fruit is heated and then mixed with alcohol (for example, Brandy) and a large amount of sugar. Smoked hams are cured in brine and then exposed to the smoke from burning wood chips.
Clapham Junction railway station
Clapham Junction railway station is a train station in Battersea in the London Borough of Wandsworth. It is on St. John's Hill in the south west of Battersea.
All services to Waterloo and many services to Victoria and Croydon stations pass through the junction; these include South West Trains, Gatwick Express and Southern services. Services from Clapham Junction also head north along the West London line, through West Brompton and Kensington (Olympia), on to Willesden Junction and Watford Junction - services (to Willesden Junction) are operated by London Overground.
Typical off-peak service of about 110 trains (one train every 30 seconds) is:
The station has 16 platforms, numbered 2 to 17, and arranged in two groups. Platform 1, the northernmost platform, is no longer used. It does not have any rails. If the planned East London Line extension gets to Clapham Junction, the platform may be used again.
The station's main entrance is from St. John's Hill, into a foot tunnel which is 15 ft (4.6 m) wide. It runs under the eastern end of the 17 platforms, and to a northern exit, which has restricted opening hours. The foot tunnel becomes very crowded during the morning and evening rush hours, and ticket barriers at the end of the tunnel are a particular pinch point.
A covered footbridge connects the platforms at their western end. The footbridge does not have an exit to or from the station.
The station is named Clapham Junction because it is close to the joining point of a number of major rail lines—although the name is not shared by any junction near the station. The names of the nearby rail junctions are:
Adenosine triphosphate
Adenosine triphosphate (ATP) is a nucleotide used in cells as a coenzyme. It is often called the "molecular unit of currency": ATP transports chemical energy within cells for metabolism.
Every cell uses ATP for energy. It consists of a base (adenine) bonded to ribose (forming adenosine) and three phosphate groups. One molecule of ATP contains three phosphate groups, and it is produced by ATP synthase from inorganic phosphate and adenosine diphosphate (ADP, the di meaning two phosphate groups) or adenosine monophosphate (AMP).
The ATP molecule is very versatile, meaning that it can be used for many things. Energy is stored in its chemical bonds.
When ADP binds with another phosphate, energy is stored that can be used later. In other words, when a bond is made, energy is stored. This is an endothermic reaction.
When ATP breaks a bond with a phosphate group and becomes ADP, energy is released. In other words, when a bond is broken energy is released. This is an exothermic reaction.
The ATP phosphate exchange is a nearly never-ending cycle, stopping only when the cell dies.
ATP is the main energy source for the majority of cellular functions. This includes the synthesis of macromolecules, including DNA and RNA (see below), and proteins. ATP also plays a critical role in the active transport of macromolecules across cell membranes, e.g. exocytosis and endocytosis.
In all known organisms, the deoxyribonucleotides that make up DNA are synthesized by the action of ribonucleotide reductase (RNR) enzymes on their corresponding ribonucleotides. These enzymes reduce the sugar residue from ribose to deoxyribose by removing oxygen.
In the synthesis of the nucleic acid RNA, ATP is one of the four nucleotides incorporated directly into RNA molecules by RNA polymerases. The energy driving this polymerization comes from cleaving off a pyrophosphate (two phosphate groups). The dance is similar in DNA biosynthesis, except that ATP is reduced to the deoxyribonucleotide dATP, before incorporation into DNA.
Shrimp
Shrimp refers to small, decapod crustacea. Shrimp are mainly found in three groups: Caridea, Procarididea, and Dendrobranchiata. There are thousands of species, and usually there is a species adapted to any particular habitat. Any small crustacean which resembles a shrimp tends to be called one.
Adult shrimp are filter feeding benthic animals that live close to the bottom. They can live in schools and can swim rapidly backwards. They have a high tolerance to toxins in polluted areas, and may contribute to high toxin levels in their predators. They play important roles in the food chain and are important food sources for larger animals from fish to whales.
Shrimp are related to prawns. In cooking, the criterion is often only the size of the animal (prawns are bigger). Biologically, prawns and shrimp can be told apart by the structure of their gills. In prawns, the gills are branching; in shrimp they are not.
Many shrimp species are caught to be eaten. Usually, the head and the digestive tract are removed before the shrimp is eaten. The muscular tails of shrimp can be eaten, and they are widely caught and farmed for human consumption.
Commercial shrimp species support an industry worth 50 billion dollars a year. In 2010 the total commercial production of shrimp was nearly 7 million tonnes. Shrimp farming took off during the 1980s, particularly in China, and by 2007 the harvest from shrimp farms exceeded the capture of wild shrimp. There is often pollution damage done to estuaries when they are used for shrimp farming.
Prawn