An attitude opposed to education, the spreading of knowledge, reason and progress. A negation of knowledge (the refusal to acknowledge as truths things which have been scientifically demonstrated) and/or an opposition against the spreading of knowledge to the greatest number of people. The spreading of theories whose falseness has been demonstrated. Obscurantism is often cited in relation to the Middle Ages and the Inquisition. At the beginning (1781) the word obscurantism designated the opinions and the doctrine of the enemies of the Enlightenment, the people who were against the spreading of new knowledge and new ideas amongst the masses. Today, for a proportion of atheists, every religion is an obscurantist belief.

This technique uses photometry and calculates the intensity and the duration of the occultation of a star by an object passing between it and the observer. The longer it is, the bigger and closer the object will be. By knowing the distance of the object in relation to the Earth, it is possible to work out its size.

A rounded marking on the skin or the wings of animals. They are often to be found on the wings of butterflies.

The Organisation for Economic Cooperation and Development. Created in 1961, in the footsteps of the Organisation for European Economic Cooperation (OEEC) which aimed to implement the Marshall Plan after the Second World War in Europe, the OECD is an international organisation which conducts and publishes economic studies for its members, essentially developed countries.

Born in 1207, died 1231. Elizabeth of Thuringia was the daughter of King Andrew II of Hungary. She married Louis IV of Thuringia, but became an early adherent of the movement begun by St. Francis of Assisi in Italy. Known for her piety and the help she brought to others, she was canonized in 1235.

In cinema, ‘off-camera’ designates that which is outside the field, beyond what the camera is filming. The off-camera contributes to the stylistic construction and narrative of the film. It is part of the story. It can consist of a telephone call, or an imagined person who sees somebody else situated within the shot, or even a monster, which the film director decides not to show for reasons of suspense or to feed the spectators’ imaginations.

A member of the dominant class linked to a country’s government. The term is above all used today to designate certain business leaders who became rich after the break up of the USSR, thanks to the transition of the Russian economy to a market economy.

genes which have the potential to cause cancer.

Flooding where the discharge is exceeded on average once every 100 years.

A group of individuals are monitored and tested over a long period of time.

The development of an individual from conception to his/her adult form.

A comics publishing house created in 1985 by Joost Swarte and Hansje Joustra

http://www.oogenblik.nl/

Comics publishing house created in Leuven in 2000 by Johan Stuyck, professor at the Saint-Luc school of art in Brussels. 

Oort’s cloud is a vast hypothetical sphere of bodies situated at about 50 000 AU  (astronomical units) from the Sun, well beyond the orbit of planets and the Kuiper Belt. The external limit of Oort’s cloud, which forms the gravitational boundary of the solar system, is situated at more than a billion times the distance separating the Sun and Pluto, or around one and a quarter light years of distance from Proxima Centaurus, the star nearest the Sun. Although no direct observation has been made of such a cloud, astronomers, basing their theories on analysis of the orbits of comets, generally think that it is the reservoir of long period comets. This cloud takes its name from the Dutch astronomer Jan Oort who came up with the hypothesis for its existence in 1950, by statistically studying fifty cometary orbits.

Isolated or one-off enquiry in the context of a still ongoing police investigation, with the aim of offering investigative leads specific to a particular criminal case.

Within the same species, there exists a genetic diversity (according to the sequences of nucleotides). An OTU is a grouping of individuals of the same species whose 16S rRNA sequences present a 97.5% similarity.
This international standardization allows researchers in the same discipline to compare their results, but it does not neccessarily have a biological significance and other similarity values have been suggested. Individuals in different OTUs cannot belong to the same bacterial species. 
In the case of the study of the cyanobacteria present in lakes Beak 1 and Beak 2 in Antarctica, different OTUs, named by numbers have made it possible to group cyanobacteria according to their genetic similarities and thus to facilitate the study of the variation of species over the centuries.

opsonisation is the operation during which substances which are foreign to the body (antigens) are recognised by the immunological system and identified as needing to be destroyed. Opsonines are antibodies or other proteins which bind to unknown antigens to 'mark' them and encourage phagocytosis.

Ores are minerals that have an economic value according to the price of metal. It is a dynamic concept which is evolving and which depends on the viability of the exploitation of a mineral deposit.

Compound which contains the element carbon and generally hydrogen. There are millions of organic compounds (methane, glucose, medicines, etc.). The term organic has been wrongly attributed, because at the time it was thought that these compounds could form only in living organisms.

Made from organic compounds, these pigments are mainly constituted from carbon, oxygen and hydrogen. They are either of plant or animal origin. Previously found in nature, they are now recreated in a laboratory thanks to organic chemistry. Organic pigments are most often transparent and brilliant.

Eric Blair (his real name) was a writer and journalist. He is famous for having written 1984, a dystopian novel that portrays Big Brother as ruling a world that is exhaustively monitored, in which the central power is total.

A chronic condition whose main symptoms include persistent knee, hip and spinal column pain. It is caused by abnormal wear and tear of  cartilage which loses its flexibility and elasticity.

An osteocyte is a cell found in mature bone; they originate from osteoblasts. The latter become osteocytes when they are completely surrounded by an extracellular matrix.

Progressive generalised demineralisation of the skeleton of elderly people and is accompanied by constant pain. It is due to an insufficient fixation of calcium and phosphorous in bone tissue.

Osteon is the basic element of compact bone. It consists of concentric bone layers called lamellae surrounding the Haversian canal, a tube containing small blood vessels, lymph vessels and nerves.

A deterioration of bone tissue which appears most often in aged people. It is due to a significant decrease (one to two thirds) of the bone's mineral density, particularly in terms of calcium and phosphorous. It is characterised by an enlargement of the medullary cavity (the central part of the bone) and the appearance of spaces between the lamellae which form the compact bone. People suffering from osteoporosis (particularly women after the menopause) see their risk of having fractures increase (hip, vertebral column). The link with vitamin D is more controversial than for osteomalacia, where the link is clearly established. Osteoporosis is partly the consequence of a drop in oestrogen levels following menopause in the absence of substitution treatment.

A toxic substance for the structures of the inner ear or the auditory nerve.

Epiclesis of Apollo, which invokes his therapeutic skills.

Reproduction strategy where the females lay fertilised eggs whose embryo growth takes place outside the mother’s body.

The action of leaving eggs in the most appropriate position to enable an optimal hatching.

Oxfam (OXford committee for FAMine relief) is a non governmental organisation with humanitarian goals, founded in the United Kingdom during the Second World War. Its initial objective was to act against the famine caused by Nazi occupation in Greece. Today it is a significant international federation of non governmental organisations (NGOs) acting on the political, economic and humanitarian fields against poverty and injustice in the world. Oxfam Belgique, created in1964, is currently made up of three organisations: ‘Oxfam Solidarité,’ a cooperation for development NGO,   ‘Oxfam-Magasins du monde,’ an organisation which promotes fair trade in the French Speaking Community of Belgium, created in 1975, and Oxfam-Wereldwinkels (1971), its Flemish equivalent.

A chemical reaction over the course of which a substance loses one or more electrons to the benefit of another called an oxidizing agent. The name of the reaction is due to the fact that it is often oxygen (from the air in particular) which is the oxidising agent. It is for example this phenomenon which is responsible for the appearance of a brown colour on a peeled apple or gives oils a rancid taste.

Hormone synthesized by the hypothalamus and secreted by the pitutiary gland which acts on the muscles of the uterus and the mammary glands, particularly during childbirth. It is thought that it also plays a part in orgasm which explains why it is sometimes crudely called ‘the pleasure hormone’.

A molecule of trioxygen (O₃) which is relatively unstable with a characteristic odor that can be detected where there is a large electrical field (an electric arc for example). This gas is naturally present in Earth’s atmosphere, forming in the stratosphere a layer of the atmosphere that intercepts a large amount of the UV radiation from the sun. If, on the other hand, it is present in too large a quantity in the air we breathe (frequently the case in towns during heat waves for example), it becomes an aggressive pollutant which attacks the bronchi. In this case, it is generally produced by the action of solar radiation on certain pollutants from cars and industrial activity.