Wednesday, October 18, 2006
Looking at meat differently…
Posted by dalieu

I was watching the news this morning, and I heard about an interesting topic. How does everyone feel about eating meat from cloned animals? Currently, the FDA is studying the meat from clone animals and stating that it is as safe as regular meat. They said that it is possible that some places may already be selling cloned meat because there is no law against it. The FDA also stated that it may not be possible to differential between “real” meat and cloned meat, so there may be no way to mark the cloned meat. I dunno, all I can say is now I’m going to start looking at the meat I’m about to eat a little differently and ask myself, “was this cloned?”

[[Updated]]

The reason for cloned meat: “eager to use clones to vastly cut the cost of food production”
http://www.medicinenet.com/script/main/art.asp?articlekey=47770

I found this site very informative because it’s from one of the companies that clones meat:
http://www.popsci.com/popsci/science/64b99082cc73d010vgnvcm1000004eecbccdrcrd.html

The Goals of Alchemy
Contrary to popular opinion, alchemy was not merely a quest for the recipe to make gold and neither was it a purely mediaeval venture. Alchemy has its origins in ancient Egypt and in ancient Babylonia, well before the birth of Christ. From the outset it was always was a much broader enterprise than the attempt to transmute base metals into gold.

Both ancient Babylonian and Egyptian cultures were very good at mining metal ores, and refining them into precious metals. Early texts give us recipes for producing various precious metals, precious gemstones and dyestuffs. Generally speaking, alchemy was about processes that would add value or usefulness to unrefined materials. One example of this was the addition of silver and copper to gold that had the apparent effect of making more gold. Another method was treating the surface of base metals to make them look like gold. Painting lead with egg yolk was one of the less successful attempts to do this!

The Theory of Alchemy
The ancient Greeks, who were excellent philosophers and scientists, created the theory of alchemy. We often give credit to the ancient Greeks for discovering that elements were made up of atoms. But, the vast majority of the ancient Greeks had a quite different theory of the nature of matter that did not involve atoms at all. They believed in Aristotle's theory of matter in which all matter consisted of four elements, earth, water, air and fire. In this scheme the earth was cold and dry, water was cold and wet, air was hot and wet and fire was hot and dry. These elements could be transformed one into another. Water (cold and wet) could easily become air (hot and wet) by being boiled

Aristotle's Elements.
Each element is characterised by a pair of the wet/dry and hot/cold properties.

All of the elements could be transmuted into any of the other elements. Everything was made of a combination of earth, water, air and fire. So, in theory at least, it was possible to transmute any starting material into anything you wanted. It was these theories that were taken up by Europeans in the Rennaissance.

Gold
Alchemists believed that everything was made up not of atoms, but of matter that had certain qualities. So gold, which could be thought of as a combination of earth and water, could also be thought of as matter which was yellow, heavy, shiny, metallic and malleable. Each of these qualities could be changed for other qualities. So, making gold would require mixing together ingredients that contained just the right proportions of the desirable properties.

There were different approaches to making gold. Some searched for the 'philosopher's stone' that would transform anything into gold immediately. Others believed that transformation would be a long process. The philosopher's stone was also linked to the search for an elixir of eternal life and youth. Just crush a bit up, dissolve in water and you have the key to eternal youth. In the decade of her thirties Queen Elizabeth I is reported to have requested an alchemist to find the elixir of youth for her.

Rather disappointingly for the two or three thousand years in which alchemy was common practise there are no known examples of the transmutation of base metals into gold. So, how come alchemy persisted for so long?

Why Did Alchemy Last So Long?

Changing anything into anything else you want seems a wonderful, but quite mad idea today. But, if you think for a moment, there is nothing very strange about the idea of transmutation. It happens on a day to day basis. Water becomes steam and ice, cakes turn from mush into crumbly sponge when baked, blue and yellow paints become green when mixed and egg whites turn from clear 'gloop' to foaming white twirls when beaten. These reactions seem mundane and everyday, but the alchemists discovered many more spectacular ones.

Start with a red powder, heat it and watch it miraculously transform into a silver liquid. As we understand it today, cinnabar (mercury oxide) was heated to release oxygen leaving behind pure mercury. Likewise take a yellow/red metal (copper) heat it together with a yellow powder (sulphur) and the result is a black powder (copper sulphate). In alchemical thought the means of producing metallic qualities was demonstrated by the first reaction. Whilst metallic qualities were removed from copper in the second (along with the yellowness of both copper and sulphur). This had to be transmutation in action.

Such impressive demonstrations of transformation were the routine of alchemy. No wonder then that alchemists believed that if they could only find the all-elusive formula, gold was there for the making. But, alchemy was conceived more broadly than the hunt for gold. Many other useful processes, like the production of metal alloys, perfumes, acids and alcohol, were all seen as progress.

Alchemy for All

There was a broad spread of how people approached alchemy. Some treated it much as we would treat chemistry. Others took a more magical approach, without being mysterious and some took an entirely mystical approach. Mystics were inclined to keep their art secret and in many surviving alchemical texts reactions are written in codes and ciphers.

Alchemy and Science

Alchemy in Europe, Arabia and China made significant advances and laid the basis from which the science of chemistry developed. It produced a good deal of lasting chemical knowledge. There was a wide-ranging knowledge of the alloys of precious and other metals, some of which we have probably lost today.

The procedure of distillation was invented by alchemists and fascinated them. Take a rose, crush up the petals, add alcohol and distil. What you get is concentrated rose oils, of the sort that are used to make perfumes. But, alchemists believed this to be a pure and active 'essence of rose' which contained 'all that makes a rose into a rose'. Because acids and alkalis had interesting reactions with metals, the alchemists developed stronger and stronger ones. Particularly aqua fortis (concentrated nitric acid) and aqua regis (a mix of concentrated nitric and hydrochloric acids) which could dissolve gold.

Interest in alchemy as a main line of research into chemical matters dwindled in the 17th and 18th centuries. Aristotle's theory of matter was replaced with a new theory of atomism in the 17th century. Alchemy seemed to be making little progress relative to other sciences. The new chemistry with fixed elements and a new terminology, was making great progress.

R



radar (also see high resolution x-band radar)

Radar (radio detection and ranging) systems use pulses of radio waves to measure distance and track moving objects. Pulses of radio waves are sent out from an emitter and they are reflected from an object back to a receiver. By knowing the time taken for the pulse to go from emitter to receiver the position of the object can be found.

Amongst other things, radar is routinely used to track weather systems and in air traffic control.



radioactive

Unstable elements emit radiation in a bid to become more stable – they are radioactive. The radiation is given out in three forms: alpha, beta or gamma. Alpha and beta are small high-energy particles ejected from the core of the atom. They quickly collide into nearby substances, causing damage. Gamma radiation is energy released in the form of an electromagnetic wave, similar to radio or light waves, but of much higher energy. Because gamma radiation interacts less with other substances it travels much further from the radioactive material than the alpha and beta particles, but it causes less intense damage.



Reformation

The Reformation was the religious revolution that took place in the 16th century in the Western Christian Church. Reformers believed that the Church in Rome had become too rich and corrupt, indulging in political and financial scheming that robbed it of spiritual authority.

The Reformation focused on going back to the scriptures for guidance. The authoritative word of God was found in the Bible, rather than in decrees delivered by the Pope. People were saved from sin not by their works – observing correct ritual, going on pilgrimage, giving to charity – but by their faith. If a person believed and trusted in the promises of God and Christ, God granted them the grace that resulted in salvation.



regression

In statistics, regression is a way of modelling the relationship between the expected value of a random variable and the values of any other variables that may be related to it. It can be used to predict the value of one of the variables if the other values are known.

Regression is also used in biology to describe the tendency to return from an extreme to an average condition. For example, the children of very tall parents can be of average height.



Renaissance

The Renaissance was a period of intellectual and economic revival that occurred in Europe throughout the 14th, 15th and 16th centuries AD. Cities and the middle classes grew, while the power of the Roman Catholic Church and the old feudal states declined. Art, literature and thought all underwent renewal as they became influenced by classical ideas.

In the realms of science and maths, renaissance scholars obtained and translated Greek texts that had been lost to Europe for centuries. These rediscovered ideas freed them from the old ways of thinking and allowed the formation of the modern scientific method.



rinderpest

Rinderpest is a highly infectious viral disease which causes high fever, discharge from the eyes, nose and mouth and severe diarrhoea. It is spread by direct or close indirect contact with infected animals and by drinking water contaminated by the dung of infected animals. Cattle, sheep, goats and pigs as well as some wild animals are susceptible to infection.

There is no treatment for rinderpest and infected animals and those in close contact are normally slaughtered to prevent the spread of infection. A vaccine is available.



robotics

Robotics is the design and use of robots. Robots are mechanical and electronic machines which are capable of doing various tasks. Their flexibility makes them different from the automated machines, found in many factories, which are designed for only one task.

S



salmonella

Salmonella is a family of over 2000 different types of bacteria, but Salmonella enteritidis and Salmonella typhimurium are responsible for about half of all human Salmonella infections.

Salmonella infection is usually contracted by eating foods containing the bacteria. It can be prevented by proper food handling practices and cooking food thoroughly. The symptoms of infection include diarrhoea, abdominal cramps, vomiting and fever and can last up to seven days.



scientific revolution, The

'The scientific revolution' is the name commonly given to the profound changes in scientific thinking that occurred in the 16th and 17th centuries. However, many science historians now think of the period as more of an 'evolution' rather than a revolution.

Medieval science had followed the teachings of the ancient Greek philosophers. Their explanation of how nature worked was based on a desire to understand the reason why a particular object behaved the way it did, rather than a mechanical understanding of how it actually happened. The new approach emphasised rigorous, repeatable experiments and observations that provided testable theories open to modification or even replacement, as new observations were made.

The scientific revolution is generally thought of as starting in the 1540s with the theories of Copernicus, who proposed that the Earth was not at the centre of the Universe. By the 1680s, Isaac Newton had cemented the changes by showing that much of nature, from the orbits of the planets to the motion of objects on the Earth, could be explained by the same simple mathematical laws.



serotonin (5-hydroxy-tryptamine, 5-HT)

Serotonin is an amine neurotransmitter made from the amino acid tryptophan. It acts as a neurotransmitter in the central nervous system, where it's involved in producing uplifting feelings.

Serotonin also plays a role in regulating sleep - the hormone melatonin, which regulates the body clock, is manufactured from it.



sleeping sickness

Sleeping sickness is the common name for trypanosomiasis, a disease caused by the parasite Trypanosoma cruzi and spread to humans by the bite of tsetse fly. The parasite that causes sleeping sickness exists only in Africa.

The first signs of infection are a sore appearing on the site of the bite followed by redness, pain and swelling. As the infection progresses, sufferers experience fever, headache, itching, mental confusion and long periods of sleep. If untreated, sleeping sickness can be fatal.

Treatment for sleeping sickness is available, but avoiding contact with tsetse flies is preferable since most of the treatments have severe side effects.


space shuttle

Until the recent Columbia disaster, there were actually four space shuttles – Columbia, Discovery, Atlantis and Endeavour. They are designed to be launched like conventional rockets but return to Earth like planes, making them reusable – and therefore more cost effective.

The shuttles have three main components: the orbiter which carries the crew and cargo, the fuel tank and the booster rockets. The fuel tank and booster rockets are discarded shortly after blast off whilst the orbiter carries on up into space.



sperm

Sperm are the sex cells produced by males. They contain half the full complement of chromosomes and will ultimately combine with an egg at fertilisation. Males tend to produce vast quantities of sperm at any one time. Sperm are tiny, each one requires only a small amount of resources to produce.



spore

Spores are dormant seed-like reproductive bodies produced by some plants, bacteria and fungi. They have tough outer envelopes and are difficult to destroy. They can develop into a new organism once they become embedded in the right environment.



stem cells

Stem cells are cells that have yet to take on a specific form and function – they have the potential to become any kind of specialised cell (eg skin, bone, hair) other than a sex cell. The obvious place to find stem cells is in the developing embryo, but they are also found in the bone marrow of adults.



sub-atomic

although atoms were once thought to be indivisible particles [see atoms], there are further layers of structure and particles below the level of the atom. Atoms consist of a core of protons and neutrons surrounded by a cloud of electrons arranged in sets of shells and subshells.

Below this layer of order lies further organisation. Protons and neutrons, at least, are made up of smaller particles called quarks. Like a series of Russian Dolls stacked inside each other, no-one knows how many series of particles there are.



supply module

Supply modules were unmanned spacecraft that took food, water and equipment to Mir and removed rubbish, allowing the Russian space station to remain habitable.

T



tissue cultures (also see culture collections and American Type Culture Collection)

A tissue culture is the growth of a single type of specialised cell (eg skin cells) outside of a living organism. The cells are grown by placing them in a suitable mixture of salts and nutrients called a medium. The cells that form the tissue can then be used for research or, for example, as skin grafts to treat burns victims.



TNT

TNT (trinitrotoluene) is an unstable chemical that is used as an explosive. Explosives work by rapidly producing a huge volume of gas which expands out in a damaging shockwave.

In weaker explosives, such as gunpowder, various chemicals have to be ground together so that they can react and cause an explosion. TNT contains all the explosive requirements within itself, so it can react more quickly, producing a devastating shockwave.



transformer

A transformer consists of two sets of wires coiled around iron cores and placed side by side. It uses electromagnetic induction to change the voltage and current of a current-carrying wire. A changing current in one of the coils creates a changing magnetic field around both this wire and the second coil. This changing magnetic field creates a changing current in the second wire. The size of the second current can be controlled by the number of coils in each wire.

Electricity from a power station has a high current and a low voltage, so lots of energy would be lost as heat in the power cables. A transformer reduces the current and increases the voltage before the electricity reaches the power cable. At the other end a second transformer increases the current and reduces the voltage again, making it safe for use in homes.



transmute

Transmutation is the changing one thing into another using alchemy. 'Impure' forms and substances were transmuted to a state of perfection. These transformations were not simply of materials, but also of the body (from sick to healthy, from old to young), or even of the soul (from an Earthly existence to an eternal one).

Alchemists believed that substances could be transmuted by undergoing various procedures such as heating, mixing with other substances, and distilling. Some believed in an elixir, or philosopher's stone, that would transmute things quickly and easily, and possibly even grant eternal life.



tularaemia

Tularaemia is caused by the bacterium Francisella tularensis. Many small animals, such as rats, harbour the disease which can then be spread to humans through flea bites, contaminated food and water or by inhaling infected airborne particles.

The symptoms of tularaemia include fever, headaches, vomiting and extreme weakness. In some cases blisters appear that quickly fill with pus and then open to form ulcers. If the lungs are affected, pneumonia can develop.

Tularaemia can be treated with antibiotics and an effective vaccine is available.



typhus

Typhus is the general name for several infectious diseases caused by the micro-organism Rickettsia. The symptoms of typhus include severe headache, sustained high fever, depression, delirium and the eruption of red rashes on the skin.

Rickettsia normally live in ticks, mites, fleas and lice and can be spread to humans by the bites or faeces of these creatures.

Typhus can be treated with antibiotics and can be prevented by vaccines.

U



uranium235

Uranium235 contains a total of 235 protons and neutrons: 92 protons and 143 neutrons. The large number of neutrons makes uranium235 unstable and by radioactive decay it transforms through a series of other elements until it reaches a stable form of lead. This process is very slow – the time taken for half a given amount of uranium235 to decay is one billion years.



uranium238

Uranium238 contains a total of 238 protons and neutrons: 92 protons and 146 neutrons. The large number of neutrons makes uranium238 unstable and by radioactive decay it transforms through a series of other elements until it reaches a stable form of lead. This process is very slow – the time taken for half a given amount of uranium238 to decay is 4.5 billion years.



utopia

A utopia is a place of perfection, where social conditions, laws and government in particular are ideal. It is also a place that doesn't exist. 'Utopia' is often used as a derogatory description of schemes for impractical social improvements. The opposite of a utopia is a dystopia

V



variant CJD

Variant CJD (vCJD) is so called because it is a relatively recently identified version of the condition Creutzfeld-Jakob Disease (CJD). CJD is a degenerative and fatal condition that produces muscle spasms and progressive dementia in people over the age of 50. CJD can be inherited or it can be sporadic, occurring for no known reason.

Variant CJD has the same symptoms as inherited or sporadic CJD, but it can occur in much younger people (the youngest sufferer contracted vCJD at 12) and has been linked to BSE or 'mad cow disease'. It is thought that people could have contracted vCJD after eating meat contaminated with BSE.

All versions of CJD and BSE are thought to be caused by prions, a type of protein found on the surface of cells in the nervous system.



Vesalius, Andre

Andre Vesalius (1514-1564) was a Flemish physician who revolutionised the study of human anatomy.

Until the 16th century the standard anatomy text used by surgeons was written by the Greco-Roman physician Galen, and dated back to the 2nd century AD. Galen had based most of his work on non-human animals, whose anatomy can be quite different to ours.

Vesalius brought a new thoroughness to human dissection, and gave demonstrations of his methods to students. He critically evaluated the ancient texts, demonstrating that they were not infallible. Working with the best artists of the day he produced the Fabrica – a more accurate textbook on human anatomy that was also a masterpiece of design and illustration.



virulent

A virulent organism is one that is harmful or deadly.

A highly virulent organism is capable of causing disease that is likely to lead to death in those infected.



virus

A virus is a disease-causing micro-organism much smaller than a bacterium. Viruses can only grow and multiply once inside the cell of another living thing as they don't contain any of the internal 'machinery' necessary for reproduction. They are parasites.



vitamins

Vitamins are substances that are needed by the body in relatively small amounts but are necessary for the body to function properly. A lack of a particular vitamin in the diet leads to a deficiency disease eg scurvy is caused by a lack of vitamin C and beri-beri is caused by a lack of vitamin B1.

There are basically two sorts of vitamins – water soluble and fat soluble. Vitamins A, D, E and K are classed as fat soluble, vitamins C and the B vitamins (there is a whole group of B vitamins – B6, B12 etc) are water soluble.

W



warhead

The warhead is the part of a missile that is designed to do the damage. Warheads are often described in terms of the 'charge' they are carrying. So, amongst others, there are nuclear warheads, chemical warheads, explosive warheads and incendiary warheads.



wheat rust

Wheat rust is a common name for several fungal infections that affect wheat. The disease causes huge reductions in yield and can destroy whole crops.

Wheat rust is identifiable by the formation of rust coloured, oval lesions on the plant.

X



x-ray

X-rays are electromagnetic waves with short wavelengths of less than one billionth of a metre (visible light is also electromagnetic waves but with wavelengths 1000 times longer). X-rays are very penetrating and can pass through flesh but they don't have enough energy to pass through bone. This means that they can be used to produce 'x-rays', ie shadowy images of bone.



X-ray crystallography

X-ray crystallography is a method of determining the structure and arrangement of molecules. Molecules are made up of atoms strung together in a particular order, like beads threaded on a chain or net. Determining the exact arrangement of atoms can be very difficult, particularly with large molecules like proteins or DNA.

A crystal contains many molecules stacked together in a regular, repeating pattern. When X-rays are beamed through a crystal, they are scattered off the atoms in a regular pattern, allowing the exact arrangement of atoms in the molecule to be deduced.



X-ray and ultraviolet telescopes

Stars and galaxies don't only give out light which our eyes can see. Different parts of the same object can emit different wavelengths of electromagnetic radiation such as radio, infrared, ultraviolet and X-rays. So to get the whole picture, it is important to look at an object at all wavelengths. X-ray and ultraviolet telescopes are sensitive to the higher energy ultraviolet and X-ray parts of the electromagnetic spectrum rather than visible light. This means they can be used to look at the more energetic or hotter parts of a star or galaxy.

Z



zinc cadmium sulphide

Zinc cadmium sulphide is a chemical that fluoresces – it produces light for a short period of time. This property means that it has been used as a meteorological air tracer.

There are now some claims that zinc cadmium sulphide may be potentially carcinogenic although it was considered safe at the time.

Legionnaire's disease

Legionnaire's Disease is a bacterial infection that causes pneumonia. Symptoms range from mild to very severe and include fatigue, fever and a dry cough. In serious cases, patients develop difficulty in breathing and diarrhoea. About 20% of people who contract the disease die. However, antibiotics are generally an effective treatment.

The bacteria that cause the disease live in water and under favourable conditions they can multiply to high levels. Warm stagnant water, found in hot water tanks or large air conditioning systems, is a favourite breeding ground. People can be infected if they inhale airborne water droplets that contain the bacteria.



Lyme disease

Lyme disease is caused by the bacterium Borrelia burgdorferi and is spread by deer ticks. The bacteria enter the skin when the ticks bite and, up to a month after the bite, spread to other organs through the blood stream or the lymph system.

The main symptoms of Lyme disease are a large red spot where the bite occurred, fatigue, chills, fever, headache and muscle and joint aches. Some people also suffer from vomiting, sore throat and enlarged lymph glands whilst a few people go on to develop arthritis or problems with nerve function.

Lyme disease can be treated with antibiotics but prevention by covering up skin when walking through areas where there are deer is best.

M



magnetism

Magnetism is the property that certain substances display of attracting or repelling each other. Only some materials, such as iron or nickel, can freely align their internal structure to produce this effect.

The Earth possesses its own magnetic field, which is generated by dynamic motions in its molten iron core. Magnetic materials can align themselves with this field. Magnetite (a form of iron oxide) was known to the ancient Chinese, who are thought to have used its magnetic properties in making compasses as far back as 2,500 BC.



mass (ie atomic mass)

Different types of atoms [see atoms] contain different numbers of protons, neutrons and electrons. The total mass of an atom, called its atomic mass, is made up of all the particles it contains. Protons and neutrons have nearly the same mass as each other, but electrons have far less. Therefore the atomic mass of an atom is normally taken to be the sum of its protons and neutrons.

This atomic mass can be written before the symbol for the element. For example, normal carbon contains six protons and six neutrons, and can be written 12C.



menopausal

Menopausal is a term used to describe women who are going through or have gone through the menopause. During the menopause, menstruation (periods) tends to become erratic and eventually stops altogether. The menopause is not fully understood but it is thought that as women age, their ovaries gradually stop responding to the hormones that stimulate ovulation. The ovaries also produce less of the hormone oestrogen and it is thought that this might be the cause of some of the physical and emotional changes experienced by women during the menopause.



meteorological

Meteorological is an adjective used to describe topics that fall into the science of meteorology. Meteorology deals with atmosphere, the processes within it and how it interacts with the surface of the Earth. The state of the atmosphere at a specific place and time is known as the weather.



microbes

Microbe is a term for any organism that is too small to be seen with the naked eye. They are also called micro-organisms. Some common microbes are viruses, bacteria, yeasts and moulds.



microbiologists

Microbiologists study organisms such as viruses, bacteria, yeasts and moulds that are too small to see with the naked eye. These tiny organisms are called micro-organisms or sometimes microbes.

N



Nasa

Nasa is an abbreviation of National Aeronautics and Space Administration. Nasa is responsible for all civil space activities, including research and development, in the US. The European equivalent is called, unsurprisingly, Esa.

The Nasa website is at www.Nasa.gov and has huge amounts of information on all aspects of Nasa's work.



nature/nurture debate

Are we the product of our genes alone or are we dependent on the environment in which we grow up? This is the basis of the nature/nurture debate but few, if any, people now hold such polarised views. Most now believe that our individual characteristics are the result of an interaction between our genes and our environment. However, there is still much debate about this interaction and how it might work.

The debate also raises ethical issues – if a person is found to possess a gene that has been linked with crime, does this mean that nothing can be done to prevent this person committing crime? Should they be locked away for the good of society even if they have not yet committed a crime?



neurotransmitter

A neurotransmitter is a chemical that transmits a signal between nerve cells. An electrical impulse along a nerve activates the release of a neurotransmitter chemical at the nerve ending.

The chemical is then released across the gap between two nerves and creates an electrical impulse in the next cell. In this way a signal is relayed from nerve cell to nerve cell.



nitric acid

Nitric acid, known to alchemists as aqua fortis (strong water), was one of the first strong mineral acids to be discovered. It was obtained by distilling together saltpetre (potassium nitrate) and green vitriol (iron sulphate) or alum (potassium aluminium sulphate). Nitric acid could be used to separate silver from gold, as silver dissolves in the acid while gold does not.

Today it is used in many chemical processes, particularly in the making of nitrate-based fertilisers.

O


obstetrics

This is the branch of medicine concerned with pregnancy and birth. Specialists are known as obstetricians.

P



pagan

Before Christianity spread throughout Europe, people followed many different religions. As most tribes had a common Indo-European ancestor, common gods and themes can be traced between them.

The pagan religions were polytheistic, worshipping more than one god. The oldest ones had a mother-goddess as the central figure, but by pre-Christian times whole pantheons of gods and goddesses were worshipped, each with their own attributes. Nature was seen as a powerful force in peoples' lives, and was treated with a reverence and importance not seen in Christianity.



pathogen

A pathogen is any micro-organism that is capable of causing disease. A pathogen will only infect a certain species; human pathogens will only infect us.



plague

There are two main kinds of plague: bubonic and pneumonic. Both are caused by the bacterium Yersinia pestis, which is spread by flea bites or caught through inhaling infected droplets from coughs and sneezes.

Bubonic plague develops when the bacteria infect the lymph nodes which then swell and are called buboes.

Pneumonic plague develops when the bacteria infect the lungs which then quickly fill with a frothy bloody liquid.

Early treatment with antibiotics is often very effective and vaccines are available for those most at risk.



proteins

Proteins are the body's building blocks and humans have over 10,000 different types. Proteins are incredibly complex molecules made up of one or more sequences of amino acids. The order of the amino acids in a protein is genetically determined – genes are the recipes for making proteins.



protein crystals (also see crystal growth)

Proteins are the body's building blocks and humans have over 10,000 different types. Scientists want to find out how proteins work so that they can understand the body's chemistry and hopefully develop new pharmaceuticals.

Proteins are incredibly complex molecules made up of one or more sequences of amino acids and how they work is directly related to their shape. Their shape and structure can be studied by shining X-rays through protein crystals – but to do this accurately very pure crystals are needed. The weightless conditions of the ISS mean that the solutions from which the protein crystals are grown are not subject to the same convection currents as on Earth. This allows larger, purer crystals to be produced.



pneumonic plague – see plague

( E Through K )

E



egg

An egg is the sex cell produced by females. It contains half the full complement of chromosomes and will ultimately combine with a sperm at fertilisation. Females tend to produce only one egg at a time; eggs require a lot of resources because they contain food for the developing embryo.



electromagnetic rotations

An electric current flowing through a wire generates a magnetic field around the wire. When a current-carrying wire is placed between the poles of a magnet the two magnetic fields – one generated by the current and the other from the magnet – interact. At some places around the wire the magnetic fields cancel out, at other places they add up. The result is that the wire feels a force due to the unbalanced magnetic field, and is pushed out from between the magnet's poles.

This motion can be harnessed to form a very basic electric motor by making the wire into a 'C' shape and placing it between the poles of a magnet. As the electric current is passed through the wire, the magnetic fields interact. The bottom of the C is pushed in one direction out of the permanent magnet and the top is pushed in the other direction forcing the C to rotate.



element

An element is a substance that cannot be broken down into different chemicals. Gold, helium and iron are all examples of elements, each contains only one type of atom [see atoms]. There are less than 90 stable elements in the Universe, but by combining together in different ways they form other substances. For example, hydrogen and oxygen, two elements, combine to produce water.



E=mc2

This simple looking equation shows that matter and energy are equivalent – that they can be converted from one to another. The terms in the equation are E for energy, m for mass and c for the speed of light. The small 2 means that the speed of light has to be squared.

The equation tells you that if you had one kilogram of matter (anything will do) and you converted all of that mass into energy, you would end up with 9 x 10^16 (a 9 followed by 16 zeros) Joules of energy. This is enough energy to keep a 100 Watt light bulb burning for about 28 million years!



enzymes

Enzymes are proteins that are produced and used by organisms to change the rate of chemical reactions within the organism. The enzymes are unchanged at the end of the reaction. Different enzymes are specific to particular reactions.

F



fission

In naturally occurring radioactivity, the nucleus of an atom changes of its own accord by small stepwise amounts, either through ejecting small particles or by simply emitting energy. In nuclear fission, the nucleus of a heavy atom is bombarded with neutrons, causing it to become unstable. The unstable nucleus splits, forming two lighter atoms and releasing free neutrons and a vast amount of energy.

If all the atoms in 1kg of uranium235 [see uranium235] underwent fission it would release about 1 million times the energy obtained from burning 1kg of oil or coal.



flash photolysis

Flash photolysis is a method of investigating the mechanism of fast chemical reactions. A mixture of chemicals is subjected to a very short, intense burst of light, normally provided by a laser. This light provides enough energy to start the chemicals reacting with each other.

Immediately after the flash, the mixture of reacting chemicals can be studied to see what molecules and molecular intermediates are being produced.



flu

Flu, or influenza, is a viral infection that causes a fever, runny nose, cough, headache, muscle ache and a general feeling of illness or malaise. Whilst the symptoms sound similar to those of the common cold, flu can be a much more serious infection and can be fatal in the elderly, very young or those with compromised immune systems.

Flu can be spread by inhaling infected droplets that have been coughed or sneezed out by an infected person. It can also be caught by handling household items shortly after an infected person.

Since flu is a viral infection, it cannot be treated with antibiotics. The main treatment is to rest and drink plenty of fluids. There are vaccines available for flu and these are normally offered to those people most at risk of contracting flu or those who are at risk of becoming very ill if they are infected.



Fludd, Robert

Robert Fludd (1574-1637) was an English physician and astrologer who developed his own brand of mystic philosophy that opposed the reductive methods of science.

Fludd was deeply interested in the many forms of occult knowledge that existed in the 17th century. From these he synthesised a new philosophy that drew parallels between the workings of the human body and of nature. He emphasised a very holistic approach to treating illnesses, considering far more than just the physical body of the patient.



food poisoning

Food poisoning is a general term used to describe the symptoms of vomiting, diarrhoea, fever, loss of appetite, nausea and cramps that occur after eating contaminated food. Food poisoning can be caused by either bacterial or chemical contamination of food or water. In many cases, toxins produced by the growth of micro-organisms are the cause of the symptoms.



foot and mouth disease

Foot and mouth disease is a highly infectious viral disease which produces a fever and vesicles, or blisters, in the mouth and feet. It can be spread by direct or indirect contact with infected animals and the movement of animals, persons, vehicles and other objects, which have been contaminated by the virus.

The disease is very rare in humans and should not be confused with the unrelated human condition hand, foot and mouth disease.

More information can be found at: www.defra.gov.uk/footandmouth/about/index.htm



fuels the Sun

The Sun is powered by nuclear fusion [see fusion] reactions that take place at its core. The centre of the Sun is extremely hot, over 10,000,000°C. This gives the hydrogen nuclei enough energy to collide with each other and to fuse together.

At its core, the Sun converts hydrogen into helium, releasing stupendous amounts of energy in the process. Every second the Sun converts 4,000,000 tonnes of hydrogen nuclei into helium nuclei producing light and heat energy.



fusion

In a fusion reaction, the nuclei of two lighter atoms fuse together to form a heavier atom, releasing energy. This is in contrast to nuclear fission [see fission] where very heavy nuclei are split in two.

Two nuclei strongly repel each other, so it is very hard to force them close enough together to react. Very high temperatures are needed, such as those found in the centre of the Sun. On Earth, a fusion bomb can be created by initiating the reaction with a small fission bomb. The reaction cannot yet be controlled cheaply enough to provide power in a fusion reactor.

G



Galilei, Galileo

Galileo Galilei (1564-1643) was an Italian astronomer, mathematician and physicist who developed the modern scientific method, uniting experimental evidence with the power of mathematics.

One of the first to view the sky with a telescope, Galileo made many discoveries including the existence of moons around Jupiter and that the Milky Way is composed of a myriad of stars. He also investigated how objects move under the influence of forces and developed mathematical solutions to these problems.

Galileo's heavenly observations and understanding of moving bodies led him to believe in the Copernican model of the Universe [see Nikolai Copernicus] and into conflict with the Church. He spent the last years of his life under house arrest.



genetics

Biology is a large subject that can be divided into a number of specialised topics. Genetics is the part of biology that deals with genes – the unit of heredity information found in our cells. It also deals with how and why living things vary.



genes

Genes are the unit of heredity information found in our cells. They are portions of DNA that contain the information needed to produce proteins, the body's building blocks.



glanders

Glanders is a contagious disease of horses, mules and donkeys caused by the bacterium Actinobacillus mallei. It can also be transmitted to humans who come in to contact with infected animals.

The symptoms of glanders include the formation of lumps or nodules in the Nasal passages, lungs and on the skin which gradually enlarge to form pus filled ulcers.

There is no completely effective treatment for glanders and it often results in death in both horses and humans. To control outbreaks of the disease, infected animals are destroyed.



gynaecology

Gynaecology is the branch of medicine that deals with diseases and conditions specific to women. Doctors who specialise in gynaecology are called gynaecologists.

H



Harvey, William

William Harvey (1578-1657) was an English physician who demonstrated how the blood circulates around the body, and the role of the heart as a pump.

Until the 16th century, most knowledge of how the human body worked was derived from the works of Galen, a Greco-Roman physician from the 2nd century AD. Vesalius [see Andre Vesalius] added new knowledge of anatomy, but many mechanisms of the human body were still unknown.

Harvey studied with Italian anatomists interested in the nature of the heart, blood and veins. By employing a new, rigorous scientific method of experimentation he was able to demonstrate how the blood circulated around the body.



heredity

The biological similarity between parents and their children is due to heredity. It is the transmission of genes which carry information about individual characteristics (eg the shape of your nose) from one generation to the next.



high resolution x-band radar

Radar (radio detection and ranging) systems use pulses of radio waves to measure distance and track moving objects. Amongst other things, radar is routinely used to track weather systems and in air traffic control.

Radio waves have a large spread of frequencies (3kHz-300GHz) and different radar systems use different frequencies depending on what they are tracking and what resolution is needed – the higher the frequency, the greater the resolution. X-band radar uses radio waves in the frequency range 8-12GHz leading to a high resolution. This means it can distinguish between two objects much closer together than a radar system using, for example, 1-2GHz radio waves.



Human Genome Project (HGP)

The Human Genome Project is a 13-year international project which began in October 1990 involving 20 institutions located in France, Germany, Japan, China, UK and USA. The objectives of this project are: to discover all the human genes and make them accessible for subsequent research; to work out the order of the estimated 3.2 billion DNA subunits that make up the genes; and to interpret the function of the human genome by also studying simpler organisms such as the bacterium E. coli.

The Sanger Centre, located near Cambridge and funded by the Wellcome Trust, is providing the UK's contribution to the project.



hydrochloric acid

Hydrochloric acid, known as spiritus salis (spirit of salt), was the last mineral acid the alchemists learned to prepare. It could be obtained by distilling common salt with nitric acid, and dissolving the gases in water.

Today hydrochloric acid has thousands of uses, from cleaning metals surfaces and synthesising plastics, to dissolving bones to make gelatine.

I



impregnated

The term impregnated refers to the transfer of sperm from the male body into the female body, or to a fertilised egg successfully implanted in to the womb of a female.



in vitro fertilisation (IVF)

IVF is a clinical procedure where eggs are removed from a woman's ovaries and fertilised with semen outside the body (in vitro). Contrary to popular belief, this is done in a petri dish rather than a test tube. Once the eggs have successfully been fertilised, one or more of the fertilised eggs are implanted in the woman's womb. Fertilisation normally occurs in the fallopian tube inside the body (in vivo).

K



Kepler, Johannes

Johannes Kepler (1571-1630) was a German astronomer and astrologer. His three laws of planetary motion described how the planets orbit the Sun, recognising that they do not move in perfect circles.

From early in his career Kepler believed in the controversial Copernican model of the Universe [see Nikolai Copernicus]. However, the new system could still not neatly account for all the motions of the planets.

Kepler had access to the superb astronomical observations of Tycho Brahe, which allowed him to show that the planets moved in ellipses rather than in circles. This was a profound leap in thinking, as people believed that all objects in the heavens were perfect, and so moved in perfect circles.



kinetic kill

Kinetic kill devices use their kinetic energy and speed of impact to disable or destroy targets rather than explosives.