A photographic sensor used in various types of equipment, which ensures the conversion of a light signal into an electronic signal. This technology, introduced in 1969, has been used in astronomy since the end of the 1970s.

A word which springs from the Greek akèdia meaning ‘indifference’, ‘negligence’. Historically, this notion was applied to a restricted group of monks who had decided to lead a solitary existence, in distinction to those who had chosen a community life. Thinking through courage from the basis of this notion thus means first of all thinking it through on the basis of solitude and discouragement.

An electrical signal crossing the neurons and causing the liberation of neurotransmitters within the synapses. The action potential is the neuron’s information unit. It is generated by a series of diverse ion channels opening and closing following an excitation stimulus.

The active site of an enzyme is the part of this enzyme that interacts with the substrate to form the product.

An explosion, in a limited geographical area, of the diversity of species springing from some original species.

When we observe a star with the naked eye we have the impression that it twinkles. Nevertheless the star does not emit fluctuating light. This apparent twinkling in fact results from a perturbation brought about by the luminous rays crossing the atmosphere. Adaptive optics is a technique born in the 1990s which allows such non-predictable distortions of the observations to be corrected in real time, thanks to telescopes equipped with deformable mirrors which are capable of compensating atmospheric turbulence exactly.

A German Christian Democrat male politician. He was first of all Mayor of Cologne, and deposed by the Nazis when they came to power in 1933. After the Second World War he became the first Chancellor of the Federal Republic of Germany (1949), a mandate which he occupied for fourteen years. He was the architect of Franco-German reconciliation and instrumental in post-war Germany gaining recognition on the international map, as well as its integration in nascent Europe. In this respect he is considered one of the founding fathers of Europe.

Fat cells.

Endocrine glands situated at the upper section of each of the two kidneys. They are made up of two parts: the adrenal cortex and the adrenal medulla. The first is responsible for the secretion of mineralocorticoids, glucocorticoids and sex steroids, whilst the second is responsible for the secretion of noradrenaline and its derivative, adrenaline.

Adsorbent products possess an extremely porous structure. Their physical properties allow them to capture and to store water and humidity in their microscopic orifice, which are laid out in layers, pores and canals. Adsorbents are insoluble in water. Following the example of clays and zeolites, active carbon is an excellent adsorbent: its ability to absorb gas and organic molecules is remarkable, from which springs its use in protective masks, as a universal antidote or in medicines to counter dyspepsia. Adsorption, not to be confused with absorption, is a process in which gas or liquid molecules attach themselves to the solid surfaces of adsorbents in various ways. Adsorption consists of the fixing of hydrogen onto the surface of the internal cavities of a porous substance, or its being locked into carbon nanotubes. It should also be noted that adsorption constitutes the first stage of reactions which require the use of solid catalysts.

'Fact of a spouse having sexual relations with someone other than his/her spouse.'

The transport of an additive quantity – heat, internal energy, an arbitrary chemical element, electrical charges – by a moving fluid, no matter what the origin of the movement, gravitational instability or an impetus given by some force. In oceanography, for example, advection refers in particular to the horizontal transport of certain properties by the fluids considered, including transport by wind or by the currents: advection of water vapour, heat, salinity, etc.

P period of variable duration which follows the neuronal action potential and over the course of which the membrane is less excitable as the membranal potential is further from the action potential threshold than at rest.

A chronic retinal degenerative disease, sometimes associated with the development of neovessels under the macula. It causes the progressive loss of central vision while leaving peripheral (or lateral) vision intact. The loss of central vision is due to the degeneration of the photoreceptors, photosensitive cells (i.e. reacting to light) located in the macula. The degree of central vision loss varies according to the type of macular degeneration, its severity, and other individual characteristics. In Western countries, ARMD is the principal cause of severe vision loss in people over 50 years of age. Approximately 20 to 30 million individuals are currently affected and this figure could double in the next 35 years due to ageing of the population.

A substance that attaches itself to a receptor and causes its response to be produced. In general, the agonist agent mimics the operation of the messenger substance that normally attaches itself to be receptor in question.

Agrometeorology, or agricultural meteorology, aims to understand the interactions which exist between soils, plants and the atmosphere. It studies the action of meteorological, climatological and hydrological actions with a view to improving the management of agricultural enterprises.

In Arab, al-Qaeda signifies the base. A terrorist movement created in 1988 by Osama Bin Laden to fight the Soviets in Afghanistan. From 1996 onwards it has engaged in a holy war (jihad) against the United States. It is considered to be the instigator of attacks on American embassies in Kenya and Tanzania in 1998 and the September 11th, 2001, suicide attacks in New York and Washington.

The albedo is the ratio of the intensity of light reflected from an object. For instance, the albedo of snow is much higher than that of the sea: snow reflects nearly all the rays, while the sea absorbs the majority.

Shortly before his death, the King of Spain Philip II ceded (in an Act of 6th May 1598) the Netherlands to his daughter Isabelle, who was soon to be married to Archduke Albert. In practice what were ceded were only the southern provinces as the seven northern provinces, which had a Protestant majority, declared themselves to be a sovereign state from 1579 onwards (the United Provinces, whose independence was not recognised until 1648).

The reign of Albert and Isabelle over the regions in question lasted from 1598 until 1621. They enjoyed relative independence from the Spanish crown, even if they were obliged to continue the war against the northern provinces. In 1609 they nevertheless signed a truce with them, from which they profited by rebuilding the ruined country. But it was above all its cultural life which was extraordinarily energetic. Architecture adopted the baroque style: the Marian basilica at Montaigu, the Jesuit church of Saint Ignatius at Antwerp (which became Saint Charles Borromée when the religious order was suppressed), and the church of the Holy Trinity at Ixelles are good examples. Their reign was also marked by the high point of the Antwerp school of painting: Rubens, the official painter to the royal rulers, Van Dyck, Teniers the Younger and the sons of Pierre Breugel contributed to the fame of the Netherlands.

The couple being childless, when Albert died in 1621, the Netherlands were once again placed under the direct control of Spain. The ‘Unhappy Century’ as historians have called it, thus began for our provinces.

Literally, a book of friends in Imageries (2001), Philippe Hamon defines it thus: ‘a collection of handwritten manuscripts, (lines of verse, pictures, thoughts, bons mots, fragments of pieces of music, little caricatures, statements of thanks or friendship) brought together on the white pages of an album which is made available to a small circle of friends, and which is often attached to a fixed location (salon, café, workshop, college; etc.) which is frequented by this circle, and written by the location’s guests in an ongoing process.’

An algorithm is a finite sequential series of rules applied to a finite number of data, allowing for similar classes of problem to be solved. By extension it is also the whole set of operational rules specific to a calculation or a computer data processing operation.

'Support made for maintenance, that is, in executing an alimentary obligation (e.g. between separated spouses or to an ascendant in need) or an obligation to maintain (parental contribution to the maintenance of a minor child)'. The 'maintenance' is the amounts paid over to a person to ensure he/she can cover the expenses associated with the needs necessary for his/her day-to-day life. Nevertheless, when the beneficiary of the maintenance is a school-aged child, the maintenance generally includes the costs necessary for his/her education. The word thus covers a broader area than the needs specifically related to maintenance.

A version of a gene, a fixed variant of a DNA sequence in a species.

A natural proteinic substance belonging to the environment and the cause of an allergic reaction. When an allergen of animal, plant or chemical origin penetrated the body, this leads to a variety of pathological symptoms. An allergen is sometimes constituted through the association of several substances.

Irritation and inflammation of the upper airways in people who are sensitive to the presence of an allergen.

A partisan of alter-globalisation, a recent word which refers to a movement which is fighting against neo-liberal globalisation and clamouring for other economic, social, ecological and social models. Its militants want to see the setting up of another society, one which would be more attentive to the sustainable development of humanity and a fair distribution of its resources.

Small molecules with a carboxyl group acid (COOH) and an amino group base (NH2) grafted on to a central carbon atom. They are the basic building blocks of proteins.

Amyotrophic lateral sclerosis is a neurological condition that affects the nervous system of adults, causing lesions on nerve cells (neurons) that eventually result in progressive paralysis. The disease is characterized by damage to motor neurons (neurons that transmit messages that cause movements). These neurons are located in the spinal marrow, and more precisely in their anterior sheath. They are also located in the motor nodes (islands of gray matter located within the white matter) of certain cranial nerves.

Disease (also known as Charcot's disease or Lou Gehrig's disease) which affects motor neurons located in the internal horn of the spinal cord as well as motor nuclei of the last cranial nerves. The incidence of ALS in Europe is 2 cases per 100,000. The most famous people afflicted with ALS are Mao Tse-tung, Stephen Hawking (astrophysicist), Lou Gehrig (American baseball player), and David Niven (actor).

In an environment without oxygen

One of the four modes of identification for humans in relation to the non-human, according to the theory proposed by Philippe Descola. According to analogism the world is constituted of an infinity of individualities. To be able to think it, to render it accessible to our understanding, the only way is to draw up a series of analogies between the species and class them accordingly, through being aware of their differences. There is thus a strong consciousness of a discontinuity which is both internal or external, or mental and physical, between humans and non-humans. This paradigm is found for example in Chinese culture.

Infection caused by the pathogenic bacterium Anaplasma phagocytophilum. Anaplasmosis first manifests itself in symptoms that are flu-like, appearing from 5-15 days after the tick bite: high fever, muscle aches, headaches and sometimes aching joints. This disease is on the rise in Belgium; the number of cases detected is quite low, but nonetheless the highest in Europe.

Italian painter and engraver (1431-1506), born in Venice but worked for a long time in Padua. His works marked a break with the Gothic style; first influences by artists such as Uccello, Fra Filippo Lippi and Donatello, announce the Renaissance, if only through a taste for the ancient and because of his mastery of perspective. A notable example is the painting Lamentation for the dead Christ (ca. 1480-1490).

19 carbon hormone steroids responsible, during embryonic life, for the masculinisation of male embryos, and at adult age for the development of male characteristics (masculine) such as the largest muscular mass, the distribution of hair and sexual motivation. Testosterone is the prototype of the androgens.

The mechanism responsible for the formation of new blood vessels from pre-existing ones.

A measurement of rotational speed. This is expressed in radians per second in the international system (rad.s-1) as well as in rotations per minute in current usage.

One of the four modes of identification for humans in relation to the non-human, according to the theory proposed by Philippe Descola. Animism grants to non-humans an interiority similar to that of humans. It is the body, the physical, which differentiates them from us. It is thus possible to have social relationships with other species. This paradigm is to be found for example amongst the Amazonian Amerindians.

A unique destiny for this young woman, who possessed heart and character, and who was married to two kings of France, Charles VIII and Louis XII. She had to battle hard, and marry, to bring peace to her Duchy. Dating from 1508, her famous Book of Hours, the Great-Hours, contains not only pages for religious inspiration, but also a herbarium (more than 750 plants are identified!) which constitute the bases of the works illuminations. The magnificent illuminations are the work of Jehan Bourdichon and Jehan Poyet.

Sociologists define anomie as the state of a group or society whose members no longer share – or barely share – common values.

A reduction or complete loss of the sense of smell.

A ‘robot’ (a term coined in 1924 from the Czech ‘Robota,’ meaning ‘forced work’) is an electronically controlled automatic mechanism which can replace human beings for the carrying out of certain operations. It is ‘anthropomorphic’ if it has human appearance.

A substance in the blood that inhibits the activation of the complement system, a cascade of biochemical substances that help the organism destroy invading pathogens.

Antibiotics are substances of microbial origin, which prevent other micro-organisms from growing or which destroy them. Unlike simple disinfectants, they perform a specific action, i.e. they deregulate the metabolism of these targeted micro-organisms without attacking the cells of the human body. The first antibiotic (*) was discovered in 1928 by Alexander Fleming, a Scottish doctor. Alexander Fleming had noticed that a strain of Staphylococcus aureus (one of his bacterial cultures) was invaded by a mould called Penicillium notatum and that bacteria stopped growing where this mould was present. He deduced that the mould secreted an inhibitive substance which he called penicillin. On February 12, 1941, a patient diagnosed with septicemia was the first person to be miraculously saved following the administration of penicillin. Since then, other classes of antibiotics have been discovered, such as gramicidin, tyrocidin and streptomycin. There are now some 10,000 antibiotics of natural origin, 80% of which come from bacteria and 20% from moulds. Not all are used for medical purposes.

(*) The same observation seems to have been made a few years earlier by a young French doctor called Ernest Duchesne, but there was no follow-up.

Also called immunoglobulins, these are molecules produced by the body in response to the penetration of foreign bodies in the body.

An apathogenic organism is one that does not cause problems for another organism that may serve as its host.

A non political character or attitude, particular to someone who displays no political opinions and who feels very distant from public affairs.

Programmed cell death process responsible for the physiological suppression of cells in an organism.

A French physician and politician. He is responsible for many works in the domain of optics and astronomy. He was the director of the Paris Observatory. But he was also a key figure in the republican party under the July Monarchy. After the Revolution of 1848, which established the 2nd Republic, he became Minister of War and the Navy in the provisional government. However, he refused to swear an oath of allegiance to Louis-Napoleon Bonaparte, the future Napoléon III.

Archaebacteria are one of the two living components of prokaryotes, the second being bacteria. Archaebacteria differ from bacteria in terms of their structure, biochemistry and physiology.

An American Jewish philosopher of German origin. A pupil of Jaspers and then Heidegger, she fled Nazism shortly after Hitler came to power to end up settling in the United States in 1941. Her political thought endeavours to decode – in particular in her book The Origins of Totalitarianism – the phenomenon of totalitarianism, seeing in Nazism and Stalinism obvious points of convergence. In addition she has examined without respite the soul of modern man, so frequently pulverized and thus become easy prey to anti-libertarian regimes. Finally, amongst the concepts she has introduced is that of ‘the banality of evil,’ brought to light during the trial of Eichmann in Jerusalem in 1961.

The Ariane programme aimed at providing Europe with the ability to launch satellites. The first designed model (Ariane I) had a take-off mass of 210 tons and was capable of placing 1.85 kg in orbit. Its first flight took place on 24th December, 1979. Eleven Ariane I rockets were fired between 1979 and 1986.

Other versions followed, allowing for larger and larger satellites to be placed in orbit. The first Ariane V flight took place on 4th June, 1996. Its take-off mass is around 750 tons and it can place satellites weighing over 9 tons in orbit.

Greek philosopher who was first of all a disciple of Plato before distancing himself from him and becoming the tutor of Alexander the Great. Above all a scholar and teacher, he founded in Athens his own school, the Lyceum. His intellectual activity embraced every domain of thought, as the titles of his principal works signal: Physics, Metaphysics, Logic, Rhetoric, and Nicomachean Ethics. Setting himself against the Platonic world of Ideas – too abstract for his taste – he anchored his thinking essentially on the concrete or the material. The morality he moreover advocated, opposed to a too acute idealism, is that of the happy medium: the courageous attitude, for example, must as much avoid the foibles of cowardice as that of an unbridled recklessness.

1948-1949: Israeli-Arab war following the creation of Israel in 1948 1956: Suez Canal crisis 1967: The Six Day War 1973: The Yom Kippur War 1982: The first Lebanese war 2006: The second Lebanese war 2008-2009: The Gaza war Certain analysts add to this list the crushing of two large Palestinian uprisings by the Israeli army: the first Intifada launched in 1987 and the second Intifada in 2000. In this respect the 2009-2009 war in Gaza could be regarded as the third strictly Israeli-Palestinian conflict.

Enzyme that catalyses the transformation of androgens, such as testosterone, into oestrogens, such as oestradiol. Aromatase is significantly expressed in the ovaries but also in the brains of males and females in most species of vertebrates.

An acronym of 'Advanced Research Projects Agency Network', the first delocalised data packet transfer computer network, and thus the basis of transferring data over the Internet. It was developed in the USA in 1969. The first users were two universities, the first to be linked up in such a way, the University of California, Los Angeles campus (UCLA) and Stanford.

The Ashkenazic culture is culture of Jews from Germany, Poland, Russia, the former empire of Austria-Hungary, and Central and Eastern Europe in general.

An incurable condition that affects the airways – the small tubes that carry air in and out of the lungs. An asthma attack can be triggered when a person with asthma comes into contact with something that irritates their airways (an asthma trigger, such as pollen or dust mites). Then the muscles around the walls of the airways tighten so that the airways become narrower and the lining of the airways becomes inflamed and starts to swell. Symptoms of the narrowing include wheezing, chest tightness, breathing problems, and coughing. Environmental factors such as pollen, dust mites, pollution, ozone levels and high levels of humidity are important, and genetic factors are also involved, though much work remains to be done for greater understanding of these hereditary factors to be reached.

Glial cells in the shape of a star found in the brain and more generally in the central nervous system.

It is the distance which separates the Earth and the Sun which comprises an astronomical unit. The distance is 150 million kilometres.

An instrument which allows the topography of a surface to be determined at the atomic level. It is equipped with an extremely small and sharp tip (some nanometres) placed on a flexible cantilever. This tip is both attracted and repelled by the atoms on the surface. These repulsion/attraction forces cause the tip to move, making the cantilever drift. These deviations are recorded and then transformed into topography. An ‘image’ of the surface is thus obtained, atom by atom.

ATP synthesis (adenosine triphosphate) is the last stage in cell respiration (during which the cells of all living organisms produce energy from organic molecules). This is a chemical reaction which takes place in the mitochondrial membrane, during which ATP is synthesised from ADP (adenosine diphosphate) and inorganic phosphate.

A virus whose pathogenic power has been weakened considerably, or totally eliminated, but which still stimulates the production of antibodies involved in the immune response to the pathogen.

A Father of the Church and bishop of Hippo, in present day Algeria, whose immense philosophical work – situated at the crossroads of Platonism and Christianity – has considerably marked Western thought. With his Confessions first of all, the first autobiography in world literature; then with his The City of God, a book which makes of each individual the site where two kingdoms coexist: that of God, of immutable character and founded on love, and that of life on Earth, of an unstable nature and grounded on pride. Amongst the several of his ideas which prevailed after his death was that of predestination, according to which the salvation of each and all depends intimately on divine grace.

An aurora polaris is called an aurora borealis – or Northern Lights – in the Northern hemisphere and an aurora australis in the Southern hemisphere. It manifests itself through the appearance of coloured veils in the nocturnal sky and are caused by the interaction of charged particles sent out by the Sun (solar wind) and the upper atmosphere. They occur in areas close to the magnetic poles.

Auto-immune diseases are due to a hyperactivity of the immune system, which attacks certain constituents of its own host as if they were foreign substances. The body then produces autoantibodies which are directed against the antibodies. It is in some ways a phenomena partial self destruction.

According to Endel Tulving of the University of Toronto, this is the capacity of a person to be aware of his prolonged existence in time. Autonoetic conscience allows us to mentally «travel» in time in order to «relive»our past experiences and project us into the future.

Organisms capable of producing organic matter from inorganic material. According to the etymology of the word 'autotroph' (from Ancient Greek: auto, self and trophos, nutrition), autrophy designates any living being which does not need another living being to feed itself. Autrophic organisms constitute the basis of every food chain.

A Persian philosopher who studied very varied domains in the field of knowledge, such as logic, linguistics, mathematics, physics, metaphysics and medicine. He greatly influenced both Islamic and Western culture. His Canon of Medicine had significant influence in Europe up until the 17th century.

Unique projection of a nerve cell that conducts electrical impulses away from the neuron’s soma (cell body) to a target. It is the nerve cell’s “lead cable”.