- Stupidity keeps flies living longer
- Woman finally decrypted
- From pastures green…
- A sniff of caffeine to get you going!
- Who’s next to become extinct?
- Amber’s hidden mysteries
- Branch-hopping Birds
Under the microscope
- Too much protection
- Brussels draws closer to Kyoto
- Blood guides
- Mirror, mirror…
- A gene that puts on weight
- The sea serpent exists
- Science likes the media
- Sudden Infant Death Syndrome
- Silver super atoms
- Stay green!
- The hippodrome at Olympia
- The memory of Jericho
Science at your fingertips
- Climate sentinels
- Did you say epigenetics?
- Science 2.0
- War and peace
- Small screen, big ideas
- Flying high at Montréal
Stupidity keeps flies living longer
‘Stupid' flies live longer. This is the conclusion one could draw from the results of a study by researchers at the University of Lausanne (CH). The team spent four years studying two populations of the same species of fruit fly. One population underwent conditioning to boost individual flies' natural learning capacities - for example by having them associate a particular smell to a pleasant taste or vice versa.
The other population served as a control group.
After selecting for several generations those individuals most able to learn, researchers observed that the life expectancy of flies in the first group reduced by an average 15% compared with the control group. Does this tell us that the nervous system of the ‘smart' fruit flies is more energy demanding? Could increased neuronal activity accelerate their aging process? Whatever the reason, the development of learning capacities seems to have a cost to these insects in terms of longevity. Not that this apparently gives them any real competitive advantage: the species, like many others, has been able to evolve down to the present day without expanding its neuronal capacity.
Woman finally decrypted
Sequenced for the first time in 2003, the human genome has since been decrypted four times... but never starting from a cell taken from a woman. At the end of May, researchers at the Leiden University Medical Centre (NL) announced they had sequenced the genome of Marjolein Kriek, a clinical geneticist at the centre.
Obtaining an optimal result required decrypting no fewer than 22 million base pairs, a bit more than 8 times the size of the human genome.
This advance opens the way to a more complete understanding of the X chromosome, of which men possess one and women two. By lifting the veil on women's DNA, this € 40 000 project contributes fundamental new data on human genetic diversity. And in a way it also re-establishes gender equality.
From pastures green…
Research from the European Quality Low Input Food (QLIF) project, which examines animal health and well-being, has just confirmed that milk from cows which are allowed to graze on natural pasture is considerably richer in fatty acid, vitamins and antioxidants than that of their counterparts raised in factory conditions. For this project, 25 farms and three different production systems - traditional high yield, certified biological and sustainable non-biological - were studied in two contrasting regions of the United Kingdom over two distinct periods of the year.
The 109 samples collected over this period clearly highlight the nutritional virtues of biological milk, particularly in summer when the cows are feeding on fresh fodder, which is the basic ingredient of high quality milk. Another aspect of this research is improving the composition of winter milk, when cows are stabled indoors and fed on conserved fodder. In these tests, ‘bio' farming, very much in vogue today, has once again proved its worth.
A sniff of caffeine to get you going!
There's nothing like a good cup of coffee to wake you up. And indeed, if the conclusions of researchers at the National Institute of Advanced Industrial Science and Technology at Tsukuba in Japan apply to human beings, the simple act of smelling the aroma of an arabica already has energizing virtues. On examining the brains of rats previously fatigued by sleep deprivation, researchers noted a reduction in messenger RNA - the molecules which permit transmission of the genetic information needed for producing cellular secretions - for 11 genes essential for brain functioning.
But after exposing the rats to the aroma of coffee, researchers observed that mRNA levels returned to near normal for nine of these genes. The two remaining genes, linked to neuroendocrinal control and oxidative stress regulation, reached above-average levels. Given that each of these genes has a human equivalent, this could well explain why we feel bad when short on sleep and feel pleasure in smelling coffee.
To better understand the process, scientists are now looking to identify the molecule of the coffee aroma which influences genetic expression. Science is clearly very much awake.
Who’s next to become extinct?
In 2007, the International Union for Conservation of Nature listed more than 16 000 species threatened with extinction. But according to a study financed by the National Science Foundation (USA), the mathematical models used in obtaining these figures heavily underestimate the dangers for fauna and flora. Two main criteria are taken into account in evaluating whether a particular species is threatened with extinction: the number of accidental deaths and the impact of external factors such as temperature or precipitation on the birth rate of a given population.
When testing traditional models in the laboratory on a group of beetles, researchers highlighted the importance of variations in the male-female ratio and of physical differences between individuals in the particular species examined.
Given that these two factors have until now been either ignored or underestimated in all studies aimed at determining which species are threatened with extinction, the global situation of the world's fauna and flora is, according to the study, much more critical than was previously thought.
Amber’s hidden mysteries
A team from the French National Centre for Scientific Research's (CNRS) Geosciences Rennes laboratory has examined over 350 animal inclusions in opaque amber from a quarry in the Charente-Maritime, a French region very popular for studying the natural environment of the Cretaceous period (around 100 million years ago). Until now, palaeoentomologists had been unable to visualise fossils imprisoned in opaque amber, representing up to 80% of the amber gathered on this type of site.
Together with colleagues from the European Synchrotron Radiation Facility (ESRF) scientists have developed a totally new imaging technology using the unique power of the Grenoble (FR) synchrotron x-rays. With it they have pierced the mysteries of 640 samples of opaque amber, making a number of major discoveries in the process. A fossil feather has formally confirmed one of the missing links between plumed dinosaurs and birds, while a fossil ant has shown the animal to be older than previously thought.
A huge international genetic study led by ornithologists from the Field Museum in Chicago (USA) has just rewritten the history of bird evolution. For each of the 169 principal bird species in existence, researchers examined around 32 000 DNA base pairs from 19 genetic loci (precise, constant positions) across 15 chromosomes.
The outcome of this enormous task, undertaken over a five-year period, is a fundamental revision of our feathered friends' family tree. Birds that look and behave very similarly, in fact belong to different species.
The pink flamingo, for example, is unrelated to most other aquatic birds. The hummingbird, a resolutely daytime animal, actually descends from the very nocturnal nightjar.
These differences are explained by the specific adaptation of certain sub-species at different stages of their evolution. For example, environmental pressure has forced certain members of a particular species to adapt to an aquatic lifestyle.
Under the microscope
Dr Nano and Mr Nano
During the week of 10 June, El País and Der Spiegel published two very different articles on nanotechnology. In a techno-optimist tone the Spanish daily presented various applications of nanotechnology in cancer therapy, describing systems that can target active substances or RNA repair patches specifically at cancerous cells - sparing patients the secondary effects of chemotherapy.
In contrast, the feature article in the German weekly was devoted essentially to the use of nanotechnology in cosmetics - more specifically sun creams - and highlighted their potential risks. While the article ended with common sense advice on the lines of "Future holidaymakers, your worst enemy is not inside the bottle at the bottom of your beach bags, but above your heads," the general tone was definitely one of caution.
The juxtaposition of these articles is striking. The subject in both cases is the human body. We want our bodies to be healthy and goodlooking.
Health has always been a favourite subject of popular science writing. Beauty is becoming another, in particular when it could be at the expense of health.
If we were to sum up the messages put across by these two texts, one might say that in the first case: "It's small and invisible, and therefore miraculous," and in the second: "It's small and invisible, and therefore dangerous." It is true that their small size can make nanotechnology products both effective and harmful. But the articles highlighted here are not well-informed proposals that express rational, objective judgements. Such sentences, and others like them, are full of archaic and irrational representations, wrapped in emotionally-charged imagery. Difficult to avoid, but certainly reason for vigilance.
Too much protection
Does protecting yourself in a sanitised world increase the risk of developing allergies and auto-immune diseases? The European project DIABIMMUNE has been launched to investigate this very question. Earlier studies showed that the incidence of intestinal diseases was five times higher among Finnish children than among children living in Carelia, a nearby Russian region where living conditions are much more basic. Given that the two populations possess identical genetic predispositions, researchers believe that protecting the body against external aggression could upset the immune system.
As a result, it may turn against its own body or react abnormally to external non-infectious proteins.
Coordinated by Helsinki University, DIABIMMUNE will study 300 babies aged under three and 2 000 children aged between three and five in three countries (FI, EE, RU).
Launched over a five-year period, the project should provide a better understanding of how our immune system develops.
Brussels draws closer to Kyoto
Good news: the European Union has nearly achieved its greenhouse gas emission targets as laid down in the Kyoto agreements. According to the European Environment Agency (EEA), Europe's emissions fell by 0.3% between 2005 and 2006, to a level 7.7% below the 1990 level, the reference year for the Kyoto Protocol. The EEA attributes this progress to reduced production at certain chemical factories coupled with reduced consumption of heating fuel due to the mild weather experienced in 2006.
The EU-15 countries can congratulate themselves on being the biggest contributors to this reduction, even if major emission increases were recorded in Finland and Denmark due to a rise in coal consumption. Coal also seems to be the cause of the mixed results in the 12 new EU Member States.
The industrialised countries that signed up to the Kyoto agreements pledged to reduce their greenhouse gas emissions by 8% by 2012 compared with their 1990 levels. Given the favourable circumstances, it remains to be seen whether the reduction observed in the EU will be maintained in the coming years
Although the link between blood circulation and brain activity was established over a century ago, the cell mechanisms that underlie this link remain largely unknown. Their deregulation is the cause of incurable diseases such as Alzheimer's and vascular dementia.
Researchers at Harvard University (USA) have identified the key role of astrocytes in the cell mechanisms that control the flow of blood to the brain. Astrocytes, glial cells present most notably in the central nervous system, seem to be activated via two distinct signalling processes that involve glutamate transporters and receptors. The discovery was made by tracing, using a multi-photon microscope, biological markers within the olfactive bulb of living mice.
The study, partly financed by a Marie-Curie fellowship, is now seeking to find out whether astrocytes play the same role in other areas of the brain.
A new endocrine mechanism involved in regulating blood sugar has just been discovered by researchers at the Karolinska Institutet (SE) and the University of Miami (USA). The project looked at the role of alpha cells in the pancreas, which have been studied much less closely than the insulinproducing beta cells that play a contrasting role. The alpha cells are known for secreting glucagon, a hormone antagonistic to insulin and whose role increases blood sugar levels. The researchers also discovered that the alpha cells even produced another hormone, glutamate, which makes it possible to further accelerate glucagon production in the case of hypoglycaemia.
The deficient insulin production that affects diabetes sufferers also interferes with this glucagon/ glutamate system, resulting in an even greater disturbance of blood sugar levels. Scientists hope that the discovery of this new mechanism will help develop more effective treatment for diabetes that targets simultaneously the insulin production system and the glucagon/glutamate production system.
Placing mirrors in the sky to offset climate change? First proposed in 1989, this solution has already been the subject of serious study by scientists who claim they could restore the climatic conditions of the pre-industrial age. The principle is simple: by placing a gigantic shield fitted with mirrors in the atmosphere, the Sun's rays will be deflected into space rather than heating up the globe. A fanciful idea? To be sure, a team from Bristol University (UK) tested the concept with the aid of climate forecasting models. They compared two future scenarios in which the level of CO2 would be four times higher than before the industrial revolution. The first served as a reference while in the second the Sun's strength was reduced to obtain the average global temperatures from before the industrial age. According to the results, the solar shields would help offset the worst effects of global warming but would not restore the climate of the past.
Also, the solution would not have an impact on other serious problems caused by the increase in atmospheric CO2, such as acidification of oceans and changes to plant growth.
A gene that puts on weight
A French-British team has discovered a new gene at the origin of obesity. PCSK1 makes it possible to code proconvertase 1, an enzyme involved in the maturation of hormones and peptides that are essential to controlling the appetite. These researchers believe that even minimal mutations in PCSK1 are enough to modify proconvertase 1 with the result of upsetting the complete hormonal system that regulates hunger and appetite.
These results were obtained by a major study carried out by a team from Imperial College London (UK) and the Institut Pasteur (FR) on the genotype of the ancestors of a group of French, Danish and Swiss volunteers.
A strong correlation between a mutation of PCSK1 and obesity was observed. A dozen genes are believed to be involved in disturbing the hormonal network and the brain receptors responsible for regulating hunger, and identifying them would enable patients to be treated at an earlier stage.
The sea serpent exists
How to harness the energy of waves for optimal results? That is the challenge being taken up by researchers at Southampton University (UK) working on the Anaconda, a long flexible rubber tube, sealed at both ends and filled with seawater. The front of the ‘animal' is anchored to the seabed while a turbine is fitted to the other end. When placed on the surface of the water, the Anaconda reproduces the movements of the waves, which produces a growing ‘bulge wave' that travels down the tube interior, making it possible to turn the turbine.
The construction was inexpensive and its rubber structure renders it more resistant to bad weather and corrosion, thereby also reducing maintenance costs. Current tests are concentrating on small prototypes. If these prove conclusive, researchers are planning to build a pilot model 200 metres long and 70 metres wide able to produce 1 megawatt of electricity.
Science likes the media
Contrary to popular belief, scientists and journalists get on very well. At least that is the message to be gleaned from a survey carried out by Hans Peters Peters (Forschungszentrum Jülich - DE) among British, Japanese, French, German and US researchers specialised in stem cells and epidemiology. Among the 1 354 respondents, 57 % say they are "generally satisfied" with their relations with the media, with just 6% saying they are "generally dissatisfied." The main motivation for scientists in cooperating with journalists is apparently to increase and improve public perceptions of science, with nearly 97 % of respondents expressing this view.
Although 9 out of 10 of them say the risk of being misquoted in the media as a whole is a major demotivating factor, more than half believe that cooperation between laboratories and the media has had a positive impact on their career. The study, carried out by the German Federal Ministry for Education and Research (BMBF), presents a picture in sharp contrast to that of many other surveys that present the relationship between science and the media in a negative light.
Sudden Infant Death Syndrome
Is Sudden Infant Death Syndrome (SIDS) linked to serotonin?
Autopsies on victims of SIDS had already shown anomalies in the serotonin neurons in the brain stem, without being able to identify exactly what mechanism led to death. As part of the NEWMOOD research project looking at the physiological processes involved in depression, researchers from the European Molecular Biology Laboratory (EMBL) made genetic changes to mice with a view to modifying one of their serotonin receptors.
The apparently normal mice suffered regular attacks characterised by a sudden drop in heart rate and body temperature.
More than 50 % of them died following such an attack before reaching adult age. If these results can be extrapolated to humans, doctors would be able to determine which babies are susceptible to SIDS before they suffer an attack. SIDS, commonly known as cot death, is the first cause of death among infants under 12 months in developed countries.
Silver super atoms
In 2005, US researchers caused a sensation by creating aluminium super atoms, an aggregate of identical and energetically stable atoms. The feat has just been repeated by a team of researchers at Delft University (NL), but this time working with silver. Filaments heated to around 900 °C produce a silver fog within which aggregates of 9, 13 or 55 atoms are created spontaneously.
Depending on their size and charge, these metal super atoms can behave like inert or halogenous gases. According to their models, the researchers predict the existence of many aggregates of this kind, some of which could possess magnetic, optical or electrical characteristics sufficient to serve as catalysts in fuels or as crystal superconductors.
Tests are now concentrating on their chemical properties by first isolating them in argon using a new technique developed by the same Delft University team.
According to a team of Greek cardiologists from the Athens Medical Centre, green tea makes coronary arteries more flexible and resistant to changes in blood pressure. At distinct times of the day researchers gave green tea, diluted caffeine and hot water to a group of 14 volunteers.
The observations showed a clear dilatation of the arteries following ingestion of the healthy Asian beverage. Green tea would thus appear to favour the secretion in our endothelial cells of a substance that is conducive to the expansion of blood vessels and free blood circulation. Flavonoids, secondary metabolites reputed for their antioxidant properties, are believed to be at the origin of this mechanism. They are found in all teas, but in green tea they are less oxidised and therefore more effective.
The hippodrome at Olympia
In May, a team of researchers headed by Norbert Müller of the Johannes Gutenberg-Universität, Christian Wacker of the German Sports and Olympic Museum, and Reinhard Senff of the Deutsches Archäologisches Institut, rediscovered what is most probably the hippodrome of Olympia. The hippodrome was believed to have been lost forever when engulfed by flood waters after the River Alpheios repeatedly broke its banks. The site, where the Roman Emperor Nero won races in person, was lying beneath a layer of lime that the river had deposited over the centuries. Using geomagnetic mapping techniques, the researchers probed an unexplored area lying to the east of the sanctuary of Olympia.
Although the hippodrome, measuring 1 052 metres long and 64 metres wide (excluding the stands), has not yet been formally identified, some very convincing features have been distinguished that correspond to that correspond to detailed descriptions in ancient texts.
The memory of Jericho
Bones dating back 8 000 years, discovered in Jericho in the West Bank, could provide valuable clues for the treatment of tuberculosis.
A team of Israeli, Palestinian and German researchers, financed by the Deutsche Forschungsgemeinschaft (DE), discovered traces of the disease when they examined the remains of prehistoric humans that were excavated more than 50 years ago.
The scientists believe they have isolated enough DNA to be able to obtain information on the way the disease developed at the time.
The origin and evolution of tuberculosis have never been established precisely but the disease is believed to have first appeared around 9 000 to 10 000 years ago in the first towns in the Fertile Crescent.
By comparing the DNA of the mycobacteria obtained from human and animal skeletons found at the site, the researchers hope to be able to finally establish whether the human strain of the disease originates in an animal strain.
Skeletten der Ausgrabungsstelle entnommenen Mykobakterien hoffen die Forscher endlich uberprufen zu konnen, ob der menschliche Stamm von einem tierischen Stamm abstammt
Science at your fingertipsTOP
Where are they? How healthy are they? On the French ArgoNIMAUX website we can follow, on a day-to-day basis, the migrations of three polar species researchers from France's space agency (CNES) and its National Center for Scientific Research (CNRS) have taken under their wing: elephant seals, albatrosses and penguins.
Some of the animals have been equipped with Argos tags embedded with mini-sensors that are sensitive to pressure, temperature and salinity. Satellite tracking of the movements of these polar animals, which are particularly sensitive to marine ecology and climate change fluctuations, should provide valuable data.
The most imposing of the animals is the southern elephant seal (much larger than its northern cousin), which can weigh up to 4 tonnes. As it spends nearly 90 % of its time under water, the elephant seal can give valuable clues about the connections between oceanic mechanisms and the complex Antarctic and sub- Antarctic ecosystems. The great albatross, a threatened species with a long life span of up to 60 years, reproduces only every two years. Monitoring it will enable researchers to find out more about the impacts of industrial fisheries on the great albatross population. King penguins feed exclusively when diving, sometimes to great depths, and out at sea during long foraging trips. They can travel for hundreds of kilometres, and these journeys will inform the researchers about annual variations in the major oceanographic parameters of the southern ocean, which is an important regulator of the world's climate.
The user-friendly ArgoNIMAUX website enables us to follow the voyages of these satellite-tracked polar animals in virtual real-time on a dynamic map charting their movements. The researchers keep a logbook featuring the animal species, together with photo illustrations. Students and the public can consult the website to see the environmental data provided by the sensors, as well as the datasheets on the various animals and other useful information. Teachers have at their disposal training kits and exercises tailored to different disciplines and levels.
Did you say epigenetics?
"You could compare the distinction between genetics and epigenetics to the difference between writing a book and reading it. Once the book has been written, the text (that is to say the genes or information stored in the form of DNA) is the same in all the copies distributed to the public," explains Thomas Jenuwein, director and senior scientist at the Max Planck Institute of Immunobiology in Freiburg (DE). "However, each person reading the book will interpret it slightly differently, because the story will arouse individual emotions and projections as they read the successive chapters. In much the same way, epigenetics allows several different readings of a fixed matrix (the book, or genetic code) leading to differing interpretations depending on the circumstances under which the matrix is examined." Thomas Jenuwein is one of the coordinators of the Epigenome Network of Excellence, a European Union-funded research consortium set up to network top-level scientists. The network also aims to involve young scientists in its research work and has earmarked one third of its funds to supporting a dozen new teams that it has created.
In addition, Epigenome has launched a dynamic website that anyone interested in epigenetics research can consult, in any of seven languages. The site presents scientific research in novel and interesting ways, including personal reports by scientists, a cartoon history of epigenetics, considerations on cloning household pets and clear explanations of the basic concepts.
It is a real mine of information, not only on epigenetics, but on genetics as well.
A debate is raging in the scientific communication world: should we rush to embrace Science 2.0 (open access science)? This concept, the name of which is clearly inspired by the term ‘Web 2.0', is currently a hot topic and refers to the burgeoning new practice of scientists posting raw experimental results, nascent theories, claims of discovery and draft papers on the Internet for others to see and comment upon.
Science 2.0 is a model that aims to revolutionise not only knowledge transmission practices (based on the Wiki model), but also the personal development of researchers (based on the Facebook enriched blog model).
There are two opposing camps: on one side there are enthusiasts of Open Access Science with no frontiers whatsoever and, on the other, there are the sceptics who fear the loss of the quality seal guaranteed by peer review and those who feel that it is wishful thinking to imagine publishing the ‘private' world of certain types of research on the web.
European scientists who advocate the open access approach have inaugurated a Facebook-style network for researchers on a website called ResearchGATE.
This new portal was inaugurated at the ESOF 2008 Conference in July 2008. It is an experiment worth watching because, in the Internet galaxy, new stars can rise very quickly but just as easily sink into oblivion.
War and peace
Peenemünde, a region in northeastern Germany, has played a key role in history. At dawn on 18 August 1943, the Allies, during Operation Hydra, dropped 2 000 tonnes of bombs on this military test site where Werner von Braun was working (together with a large crew of forced labourers and prisoners of war). It was here that the infamous V-1 flying bomb and A-4 rocket (more commonly known as the V-2 - the prototype of all military and civilian booster rockets) were developed.
Peenemünde now regards itself as an international meeting place and cultural venue for furthering world peace. The Peenemünde Historical Technical Information Centre is housed in the power station of the former military test site. Workshops, seminars, and exhibitions examine the ambivalent nature of technological progress and the risks inherent in it. There are numerous issues of debate from technology to ecology, politics and ethics. The Center's 5 000 m2 of exhibition space is divided into two sections.
The first contains historical documents, films, interviews and models. The second is devoted to the historical development of rocketry following World War II, the arms race during the Cold War and the first civilian space flights.
The surrounding area also features an exhibition of large objects and a signposted path in the Peenemünde Monument Landscape area where visitors can witness the scars of history firsthand. The centre was awarded the Coventry Cross of Nails for its contribution to reconciliation and world peace.
Small screen, big ideas
Zap onto the Da Vinci Learning knowledge TV channel and you might get totally hooked. That's because science is very exciting stuff when it is well presented, explained and approached from an original angle. For example, the great Freud had strange mannerisms and was terrified of the number 62. Only anecdotal?
That is by no means certain. In any case, it does offer a new take on understanding the issues Freud was exploring. Freud, like Darwin and Beethoven, is featured in the British BBC series Great Thinkers.
The film Nature Tech explains bionics (or the way in which technology draws inspiration from nature). The series Maths Mansion combines scary fiction with mathematical problems. The list is endless.
Da Vinci Learning has gathered together all these films, documentaries and educational programmes with the same aim: to arouse curiosity and a thirst for knowledge. The broadcasts were produced by a wide variety of European, Japanese, Australian and North American television channels and have attracted large audiences.
They have enabled children and parents, teachers and pupils to immerse themselves in an entertaining way in the worlds of biology, geology, futurology, history, chemistry and much more.
The objective of Da Vinci Learning is to disseminate in Central and Eastern Europe programmes that have proven their worth in other countries. The new knowledge TV channel does not plan to rest on its laurels though, and welcomes any new proposals and ideas.
Flying high at Montréal
The recently inaugurated Montréal Science Centre claims to be the largest of its kind in the world. Its bilingual English/French website is a good example of the evolution of virtual communication in science centres. On the website, many young people serve as guides, everyone is on familiar terms, music and computergenerated pictures abound and interactivity is the name of the game. You can step into the shoes of a scientific journalist and create a news report, or learn more about the dreams of humanity by engaging in discussion with virtual scientist-dreamers. If you prefer a moment of quiet respite, take a look at the online magazine. Teachers have not been forgotten either, with a variety of teaching activities under the heading ‘Éclairs de Science.'
Nature in RGB
From cathode ray tubes to computer screens, all colour images are based on the same coding system. The principle is simple: any colour can be obtained from nuances of the three primary colours: red, green and blue, each one coded in the RGB (Red, Green, Blue) colour model on one byte (8 bits of information). This allows for 28 (i.e. 256) shades of red, green or blue, giving a total of 16 777 216 combinations, which far exceeds the number of colours that our eyes can distinguish.
Broadly speaking, this coding system is based on the coding system used by the retina in the eye. The retina is lined with two types of photoreceptors: rods and cones. Information from the rods is sent to the brain in grey scale.
The electrical impulse provided by the cones informs the visual cortex of the colours perceived. In humans, there are three types of cone, sensitive to red, green and blue.
A simple experiment can be used to demonstrate that the layout of this mosaic of detectors is far from random. Take a brightly coloured object, such as a highlighter pen, and ask a human guinea pig to simply stare straight ahead. Starting from behind the subject's head, slowly bring the coloured object around the head into the subject's field of vision.
Waving the object can be helpful with this experiment. As soon as the subject notices a movement, stop and ask what the colour of the object is. It may come as a surprise to the unsuspecting guinea pigs that they are unable tell you!
This experiment shows that the rods are mainly located on the periphery of the retina, whilst the cones are concentrated mainly in the centre.
Although limited to black and white, the rods have the advantage of functioning at low light levels, which is not the case for cones.
This explains why ‘at night all cats are grey.'
Alexis, physicist, age 27
I have always had an urge to understand things and to look beyond appearances. For me, studying science was not only a way to help to create new knowledge, but also as an alternative way to understand the world. There is no doubt that the 20th century will go down in history as the one when human societies were transformed by science and technology.
I am half Greek and half French, and have lived all over the place, including Paris, Brussels, Oxford and London.
It was during my Erasmus year in France that I first heard about carbon nanotubes and learned that new phenomena could be studied on a nanometric scale. This prompted me to spend a year in the electronic microscopy department of Université Paris-Sud. I am currently a postdoctoral student at the Max Planck Institute in Stuttgart (DE), working as a physicist in a multidisciplinary team set up to develop new types of biological sensors using nanomaterials. The objective is to give general practitioners access to personalised medicine by enabling them to carry out real-time analyses on a few drops of blood. Although we are not there yet, it is gratifying to participate in a project like this, not just in terms of the project's objective but also because there is such a rich cultural and scientific working environment.
Researchers need to deepen their thinking and make a firm commitment to the knowledge they produce. They must be aware of the impact of their work on society and on the environment, and actively disseminate knowledge to a wider audience. This is a corollary of the paradigm shift that laboratories have undergone in recent years, where the pressure for patents and applications has once and for all put an end to the image of scientists locked away in their ivory towers.
In parallel to my research, I have taken part in a number of debates on nanotechnology. Dozens of presentations to a variety of audiences have convinced me that, even in complex areas, ordinary people are able to identify the key issues and the compromises required to maximise new technology's positive contribution. Provided we ask their opinion, that is, which unfortunately rarely happens.