Galileo project - hot news

Galileo project

Jean-Charles Bazin

CC500-GroupA - If you ask anyone the name of a positioning system by satellite, they will probably answer nothing but GPS. But how many people know that the USA have a complete control on the GPS signal? Concretely U.S. authorities have the right to limit the localization accuracy, decrease the signal strength and even shut down the access. To overcome this important limitation, European Union has decided to develop its own positioning system by satellite which is referred as Galileo. In this paper, the concept of localization by satellite is introduced first. Then the reasons leading to the development of a European GPS are explained and finally, the economic and political issues are presented, which will permit to explain how much important the coming 7^th of June is.

Constellation of GPS satellites used for positioning

Positioning by satellite

Being able to know his position at anytime has been a dream since the humanity exists. Thanks to personal GPS receiver, this dream has become true for only 100 dollars. The term GPS refers to an amazing system composed of about 30 satellites orbiting at 20 000km and complex monitoring stations. The basic idea of positioning by satellite is actually very simple: a GPS receiver can calculate its position by measuring its distance with respect to three or more satellites. Indeed by measuring the time delay between the transmission and reception, and as the signal speed is known, the device can compute its distance to the satellite. Doing so for at least three satellites, the GPS receiver can estimate its position by simple trilateration. Combining this basic method with advanced technology, an accuracy of 5 meters can be obtained.

A personal GPS receiver from Magellan society

Galileo - the European GPS

Currently, two localization systems by satellite exist: the American GPS and the Russian GLONASS. Due to the collapse of the Soviet Union, GLONASS has not been correctly maintained so that only eight satellites were in operation in 2002 and therefore GPS is the most widely used system. However, less than two weeks ago, Vladimir Putin has decided to open full signal access to civilians and restore the entire satellite constellation within 5 years. Simultaneously, European Union is developing its own positioning system by satellite. Indeed, as explained in the introduction, the US ministry of defense can limit the GPS localization accuracy, decrease the signal strength and even shut down the access, at any time without informing users in advance. Thus in 2002, EU has officially signed Galileo project funding and planned a civilian use as soon as in 2010.

Political and economical issues of the Galileo project

The main reason why EU decided to develop its own positioning system was to be independent from the American ministry of Defense. Indeed how any military equipment from any European countries could be under the indirect control of the US government? However, the huge amount of money involved in Galileo project has made some interest conflict emerged between countries. For examples, large countries wanted its national organization be in charge of manufacturing the satellites: Thales or Alcatel for France, Aliena for Italia, SSTL for UK, Deutsche Telekom for Germany, etc... Concerning smaller countries like Poland, Austria or Greece, they are arguing to obtain the tracking stations inside their national territory. Moreover, an important part of the project budget came from private funds. However, regarding the difficulty of the actual situation, some institutions have cancelled or decreased their financial propositions so that the project is now under-funded. Therefore this complex situation has led to important tensions and as a consequence, Galileo project is two years late with respect to the initial development plane. In order to solve these political and economical problems, a crucial meeting will be held on the 7^th of June. For example, an important point is that Galileo became a project fully supported by public, i.e. private funds are not allowed. However such a decision can be taken only if the 27 members of the European Union vote it at unanimity. If concrete solutions are not found during this conference, it will have strong consequences for the future development of the European GPS, not only for European countries but also the nations that participate to the project, such as China, India and South Korea.

References:

- http://en.wikipedia.org/wiki/Galileo_positioning_system

- http://en.wikipedia.org/wiki/Global_Positioning_System

- http://en.wikipedia.org/wiki/Satellite_constellation

What is DNA?

What is DNA?

DNA is a long fiber, like a hair, only thinner and longer(Fig. 1)(1). It is made from two strands that stick together with a slight twist. Proteins attach to the DNA and help the strands coil up into a chromosome when the cell gets ready to divide. The DNA is organized into stretches of genes, stretches where proteins attach to coil the DNA into chromosomes, stretches that "turn a gene on" and "turn a gene off".

Figure 1 DNA strand

The genes carry the instructions for making all the thousands of proteins that are found in a cell. The proteins in a cell determine what that cell will look like and what jobs that cell will do. The genes also determine how the many different cells of a body will be arranged.

In these ways, DNA controls how many fingers you have, where your legs are placed on your body, and the color of your eyes.

What's the difference between DNA and a chromosome?

A chromosome is made up of DNA and the proteins attached to it. There are 23 pairs of chromosomes in a human cell(Fig 2). One of each pair was inherited from your mother and the other from your father. DNA is a particular bio-molecule. All of the DNA in a cell is found in individual pieces, called chromosomes.





Figure 2 human chromosome

Why do you want to learn about DNA?

If you have gotten this far, you already have some curiosity about DNA. That curiosity may have come from hearing about it in the news or in the movies. A revolution has occurred in the last few decades that explains how DNA makes us look like our parents and how a faulty gene can cause disease. This revolution opens the door to curing illness, both hereditary and contracted. The door has also been opened to an ethical debate over the full use of our new knowledge. In the end, curiosity is the reason to learn about DNA. Fittingly, curiosity is the driving force behind science itself.

What’s Genes?

I’ll tell you a bit about genes. Genes are stretches of DNA and all have assigned places on the cell's chromosomes. There's all sorts of other fragments that have assigned places, but they're not genes. Think about there's the on switches that tell a gene when its time to go to work. For example, right after you eat, the insulin-on-switch tells me to get busy!

And then there's the off switches that give a gene time off. For instance, when enough insulin has been made, the insulin-off-switch works.

Not to mention the docking sites for special proteins to bind when its time to wind up into a chromosome before cell division. And what about all those stretches of DNA that do who knows what?

How are genes all fit on the chromosome? Let's take a peek at the DNA Ladder. Can you find gene? For example, I suppose A is a pretty small gene as far as that goes. It is only about 230 nucleotides long. When you consider that all the DNA in one nucleus of one human cell adds up to over two and a half billion (2,500,000,000) nucleotides long, well, I'm kind of trivial. However the size has nothing to do with importance. And the existence of gene is important.

Think about how to make hemoglobin and myosin transcribing gene.

The B gene , who knows how to make hemoglobin, is about twice A size. And then, there is the C gene, who knows how to make myosin, the protein that makes muscles work, which is 20 times bigger than A gene product! It’s amazing.

How do genes do it? Keep the blueprints for making proteins? After all, we are made from only 4 different nucleotides! Fact is, genes are so simple, scientists used to call them the 'stupid substance'. Genes had a good laugh over that announcement! However eventually those scientists figured out our secret.

You know proteins are made from building blocks, too. Only their building blocks are different from gene’s and are called 'amino acids'. There are 20 different amino acids that can be used to make enzyme like polymerase. That's what threw those scientists off a clue for a while. They were thinking, since protein is made from 20 kinds of building blocks and genes are only made from 4 kinds. Is it possible?

DNA STRUCTURE

In chromosome, there are a lot of genes here, so it can get pretty confusing. Genes are the brains behind the whole operation - not just the nucleus, but the entire cell and even the entire body. Each of genes have only one job to do. That's to remember exactly how to construct a single protein. Gene A, for instance, keep the blueprint for making insulin. Insulin tells your body that the glucose (sugar) levels are too high and that your cells should begin using it to make fat. Gene B lives on another chromosome, keeps the blueprint for making hemoglobin. Hemoglobin is the protein that carries oxygen around in your bloodstream. Your body needs to make hemoglobin all the time. However gene A doesn’t have to work every minute. Your body doesn't need insulin except right after you eat. So, I get some time off between meals.

That's why I can show you around chromosome.

Let me introduce you to polymerase. Polymerase is not a gene. It's not even DNA. Polymerase is a protein: a special protein called an enzyme. Gene may be the brains around here. Like Gene said, polymerase’s full name is DNA Polymerase. It’s job is to construct an exact copy of all the chromosomes just before the cell divides. Actually, it takes a whole team to do that job, and it’s part is to super-glue the nucleotides together.

Gene and polymerase are made out of small pieces hooked together to make a long strand; like train cars are the small pieces that are hooked together to make a long train. Polymerase is made out of small pieces called 'amino acids'. Gene and the rest of the chromosomes are made from small pieces called 'nucleotides'.

Here, let me show you what a nucleotide is.

Here you can see nucleotides being made from a base, a sugar, and a P (phosphate)(2). There are four factories like this, each making one type of nucleotide for gene to use in making a new chromosome. One factory makes a nucleotide with the name 'adenine' that we just call 'A'. There are also factories for making 'thymine' ('T'), 'cytosine' ('C'), and 'guanine' ('G').

That's what all the Genes and all the rest of the chromosomes are made of. See the left hand end of the nucleotides? Those are sticky spots that cause the two DNA strands of a chromosome to stick together. Scientists call them 'hydrogen bonds'. And see how A and T have two sticky spots and C and G have three? That makes A and T pair up and C and G pair up(3).

1. Alberts, Bruce; Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walters (2002). Molecular biology of the cell:New York and London: Garland Science.

2. Ghosh A, Bansal M (2003). "A glossary of DNA structures from A to Z". Acta Crystallogr D Biol Crystallogr: 620 – 6.

3. James D. Watson(2005). Molecular biology of the gene: fifth edition. Cold spring harbor laboratory press: 100 – 2.

TGV

TGV

Jean-Charles Bazin

CC500-GroupA – What does TGV stand for? Whereas this acronym is completely unknown for most of people, TGV is simply trying to... conquer the world! TGV derives from the French expression “Train a Grande Vitesse” which means high-speed train. Last month, this “bullet train” has largely overcome the speed record on railroads which is a good opportunity to look back on this amazing scientific project. First, historical information will be introduced. Then, current position of TGV will be analyzed. Finally, the future of TGV in the world will be presented.

Historical information

In sixties, less and less people used to take train in France. SNCF, the national enterprise that owns almost all of France's railway system, has taken a risky gamble: if trains go faster, more people will choose train for traveling. At this time, a single high speed train existed in the world: the Japanese Shinkansen. Therefore, French government has put a lot of effort in research to develop a national high speed train: the “train a grande vitesse” TGV was born. The first TGV prototype was powered by gas turbine and reached a top speed of 318 km/h in 1975. However due to the oil crisis of 1973, gas turbines were not economically viable and politics drastically decided to make TGV a full electric wheeled train by overhead electrified lines thanks to the many French nuclear power stations, which preserves the energetic independence of the country.

The French TGV is the fastest wheeled train in the world

Current Position

TGV has gathered an impressive list of world records. The most satisfying award for French government is that one month ago, TGV has established a new speed record on rails: 574.8 km/h. Therefore TGV is still the fastest wheeled train, far ahead from the wheeled Shinkansen that has simply reached 443 km/h. However one may notice that the magnetic levitation version of the Shinkansen had reached 581 km/h in 2003.

Another recent record has been established in May 2006 when TGV (in his Eurostar version) has run the longest non-stop journey in the world. The 1421 km separating Cannes from London have been traveled in only 7 hours 25 minutes. Note that this performance broke the previous record set by also a TGV travelling from two geographically opposite French cities: Calais at the top North near England and Marseille in South lying in the Mediterranean Sea (1067 km in 3hours 29 minutes).

Finally, TGV is the only train in the world that has recorded no single fatality for more than 30 years in operation.

Future plan

In 2006, French president Jacques Chirac has pledged that no SNCF train would be powered by fossil fuels by 20 years. Obviously, most of trains do not use fuels directly, so it means that electricity used by trains must be produced by other energy, especially nuclear power. Actually, current nuclear power stations already generate most of electricity used by SNCF trains.

TGV has an important role to play abroad to enhance its development. After 12 years of partnership with ALSTOM (the manufacturer of TGV), South Korea has operated its first high-speed journey in 2004. This step was very important for both nations: Korea for a more uniform development of the country (capital at the north, heavy industries at the south, etc...) and France for a living advertisement of is know-how and its expertise. Clearly, the next step is to commercialize TGV to China, and also to USA for their first high speed train.

The longest non-stop train journey in the world performed in May 2006 by TGV in Eurostar version transporting crew of Da Vinci Code from London to Cannes for the Cannes film festival

To conclude, the risky gamble taken by SNCF in early sixties has been a success: TGV has carried near two billion passengers. The economic policy of SNCF and ALSTOM is clear crystal: develop a perfect railroad system in France and present it as the best train in the world. That is why we can expect that SNCF will try its best to develop new systems to beat the Japanese Shinkansen. The remaining question is: how many years will be needed to reach the 7 km/h that separate TGV and Shinkansen?