Category Archives: Science

Out of this World: An Evening with the Planets

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This post was contributed by Henry Rummins, Communications Manager at Birkbeck, University of London

1.-SpaceIt is a question which humans have pondered for thousands of years when looking up at the night sky and seeing the thousands of dots of light which gradually twinkle into view: what is out there, beyond our world?

It was these questions, too, which led Dr Louise Alexander, now a post-Doctoral researcher at the UCL/Birkbeck Centre for Planetary Sciences, to follow her curiosity and begin a journey which would begin at introductory classes at UCL to a Master’s degree and PhD at Birkbeck to her current destination, analysing rock samples brought back from the Apollo 12 mission to the moon, to determine lunar geology.

Her story was one of six presented on the evening in a showcase of planetary wonders hosted by Steve Cross, Head of Public Engagement at UCL, comedian and founder of Science Showoff, looking at aspects of the solar system ranging from our closest neighbour, the moon, to distant Pluto and beyond. Yet while the planets were the stars of the show, the stories of all the researchers in planetary science reminded us that reflecting on the cosmos often brings that questioning back down to Earth, and what it means to be human; to look up and the night sky, and wonder.

It was a theme which ran through Clara Sousa Silva’s look at Twinkle, a space mission that will analyse light reflected from planets outside the solar system to reveal the chemical composition of their atmospheres, as well as, it’s hoped, their weather and history, giving crucial clues to worlds outside the solar system and potentially spotting clues for life elsewhere.

As well as the science behind the project, she also looked at how to encourage more women into studying science in school through to university level, and subsequently pursing research as a career option, illustrating her point with some sobering facts on the current low level of female participation in the sector.

A fly-by of planetary science made up the evening’s contribution from Dr Pete Grindrod, who busted some of the most widely believed myths about Mars, with a look at the origins of planets and the Rosetta comet mission by Geraint Jones and a look at missions to Jupiter by Lucia Ray making up the trio.

The evening rounded off with the first performance of a new piece of music interpreting the celestial dance between Pluto and its moon Charon, called Pluto and Charon – A Planetary Waltz. The piece – commissioned by the Centre for Planetary Sciences at UCL/Birkbeck – was accompanied by grainy footage of Charon orbiting Pluto, enhancing the original piece played as a piano duet between Valentina Pravodelov and Kerry Yong. It ended the evening where we started: stimulating the excitement and curiosity of wondering, what’s out there?

An Evening with the Planets was presented by The Centre for Planetary Sciences at UCL/Birkbeck

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Spatial Distortion in Perception and Cognition

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This post was contributed by Elena Azañón and Luigi Tamè, postdoctoral fellows in Birkbeck’s BodyLab

matthew-longoProf Matthew Longo gave his inaugural lecture about “Spatial Distortions in Perception and Cognition” on June 4th. He has been a lecturer in the Department of Psychological Sciences at Birkbeck, University of London, since 2010, and has recently been appointed Professor of Cognitive Neuroscience in the same Department.

He completed his PhD at the University of Chicago in 2006 and spent several years at the Institute of Cognitive Neuroscience at University College London as a postdoctoral researcher before joining Birkbeck. The main focus of his research concerns the psychological and neural mechanisms underlying body representations, and how these affect all aspects of our mental lives.

Longo’s inaugural lecture was introduced by the Master of Birkbeck, Prof David S Latchman, who commented on Longo’s exceptional achievements during his remarkable career. Professor Latchman highlighted the high quality of his research and impressive publication record in high impact journals. Indeed, Longo has been recently awarded by two of the major internationally recognised early career awards, in Europe (i.e., the 2014 Experimental Psychology Society Prize) and overseas (i.e., the American Psychological Association Distinguished Scientific Award for Early Career).

Pathological conditions

Longo started his lecture by highlighting that in many situations healthy people appear to have distorted representations of their bodies. However, despite these distortions, people are able to appropriately interact with the environment. Longo continued by describing several bizarre pathological conditions characterised by distortions in the representations of the body.

The underlying idea is that pathology is a continuum and, in one way or another, healthy people might share some features of these deficits. One of the paradigmatic examples he mentioned was the phantom limb experience, a condition in which a patient who has suffered the amputation of a limb, continues to experience the limb. In this respect, he recounted an elegant historical anecdote about Horatio Nelson’s phantom limb experience after loss of his arm, which was described by the admiral as proof of the immaterial soul.

He finally mentioned a patient, described by Oliver Sacks, who repeatedly fell out of her bed. When asked the reason of this behaviour, the patient complained that the nurses were secretly introducing a severed arm in the bed with her. The nurses finally realized that the patient was affected by somatoparaphrenia (i.e., the lack of awareness of a part of the body). It was the patient’s own left arm, which she believed was somebody else’s arm that she was throwing out of the bed!

Spatial distortions in perception

Before starting to describe his own work, he explained more about the idea of spatial distortions in perception. This is somehow a counterintuitive concept considering that the goal of perception is to create a veridical model of the world.

If people perceive a distorted world, how can they possibly act on it in an appropriate way? As an example of normal distortions, he described the representations at the level of the primary sensory and motor cortices in which the body parts are represented with different levels of magnification. Longo explained that these distortions are necessary steps to achieve complex behaviours.

Indeed, if we had homogenous tactile sensitivity across the body, then apparently simple tasks such as lacing up our shoes would be impossible. What allows us to perform everyday actions, which seem simple to us but are incredibly complex from a motor control perspective, is that different bits of the skin are represented differently in the brain. That is, bits of the skin able to produce fine-grained movements, such as the fingers, have extremely high tactile sensitivity, while others, such as the back of the leg have much less sensitivity.

Examining distortions

In the second half of the lecture he demonstrated that body representations are not only distorted at the level of the primary cortices, but also, though to a lesser degree, at higher levels of perceptual processing. Across several experiments, Longo made use of Weber’s illusion. In this illusion, the perceived distance between two touches is larger on skin regions of high tactile sensitivity than on those with lower acuity. His research suggests that the dorsum of the hand, but not the palm, is implicitly represented wider and squatter than it actually is. He argued that these distortions are partly explained by the shape of the tactile receptive fields of cortical neurons on the different parts of the hand.

Longo continued describing similar distortions of the representation of our bodies that are independent from touch. In order to isolate and measure this implicit body representation, Longo developed, jointly with his former supervisor, Professor Patrick Haggard from UCL, an elegant, simple and effective paradigm.

Participants used a long baton to judge the location of the knuckle and tip of each finger of their own occluded hand. By comparing the relative location of each landmark, he was able to construct implicit maps of the represented shape and size of the hand, which could then be compared to the actual hand shape. He found that these maps were drastically distorted, and in a highly consistent manner across individuals. In particular, across a number of studies, Longo revealed a general underestimation of finger length and an overestimation of hand width. These distortions are similar to those he found in the tactile modality. He further noted that this pattern of results was highly stable across body parts.

The event concluded with a final speech by Professor Martin Eimer. He thanked Longo for his exciting and entertaining lecture. He further highlighted the high productivity and creativity of Longo’s research during his early career, exalting the elegance of his experimental approach and design. He also highlighted that despite being a great scientist, he is likewise an excellent colleague, who is always available and willing to perform mundane duties that despite being unexciting, are fundamental for the department’s life.

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Visualising the inner workings of the living cell

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This post was contributed by Clare Sansom, senior associate lecturer at the Department of Biological Sciences

microscopeDr Alan Lowe, who gave the second of the two Science Week lectures on March 25, is a relatively new arrival at Birkbeck. He has been a lecturer at the Institute for Structural Molecular Biology – that is, his post is jointly held between Birkbeck and UCL – for two years.

He obtained his degrees from the universities of Bath and Cambridge and spent several years in California as a postdoctoral researcher before he was appointed to this position. He is researching the development of techniques that allow him to see inside individual, living cells, to identify single molecules, and to follow biochemical processes in ‘real time’.

Lowe started his lecture by citing the so-called central dogma of molecular biology, which can be stated in simplistic terms as ‘DNA makes mRNA makes protein’: or, in other words, that the information in DNA is transformed into the molecules that implement biochemical processes, the proteins, via mRNA.

This, however, has to be very tightly regulated to ensure that the right reactions are carried out in the right cells at the right times: regulation that is out of kilter can cause serious disease.

Metabolism is generally regulated in one of three ways. Taking a simple reaction such as
A + B à C, if you want to limit the amount of C that is produced, you can remove A or B; you can inhibit the enzyme that carries out the reaction; or you can separate A and B into different compartments.

Animal and plant cells contain many specialist compartments, the most important of which is the nucleus that segregates the chromosomes that contain the DNA from the rest of the cell. Proteins that interact with chromosomes can be kept outside the nucleus and therefore inactive until they receive a signal to enter it. Disruption of this signalling or of the nuclear membrane can lead to cancer.

A diagram that shows the distribution of (for example) molecules of one protein within a cell at a given time can be thought of as a map. Like a map, too, this information is limited because it is static. It is more instructive to follow the distribution over time, and that, too, has a geographical equivalent.

Lowe explained that when he was living in California the San Francisco Exploratorium conducted an experiment in which they gave a GPS device to each taxi in the city and followed them all over 24 hours. They could follow one taxi throughout the day or see how the overall patterns changed from hour to hour; the results are still online.

Most of the taxis behaved in a fairly predictable way, but one result could never have been predicted: a taxi landed up in San Francisco Bay. Even now, nine years after the experiment, no one knows exactly why; this is, perhaps, the geographical equivalent of a molecular event that provides one of the steps leading to cancer.

Lowe explained that he would like to be able to put a mini-GPS unit on a molecule within a cell so that it could be tracked in a similar way. This is not quite possible, but it is possible to attach a glowing molecular probe to a molecule. A protein that is isolated from jellyfish and that is known, for obvious reasons, as green fluorescent protein (GFP) can be attached to other proteins to make them glow when exposed to ultra-violet light. Derivatives of this protein have been produced that fluoresce with all the colours of the visible spectrum. It is possible to label interesting proteins with a fluorescent probe and track them through a microscope as they move through the cell, just as the San Francisco taxis were tracked.

One problem with this technique, however, is that optical microscopes and fluorescent probes rely on the visible part of the electro-magnetic spectrum. The protein molecules that we are interested in tracking are smaller than the wavelength of visible light, and, therefore, they will appear fuzzy, with all the fine detail missing. This problem was only solved by the invention of the super-resolved fluorescent microscope: its developers, Eric Betzig, Stefan Hell and William Moerner, were awarded equal shares of the 2014 Nobel Prize in Chemistry.

Lowe went back to the example of proteins entering the cell nucleus to explain this further. The membrane that surrounds the nucleus, which is known as the nuclear envelope, typically contains about 2000 nuclear pore complexes. Each complex has an hourglass-like shape with a narrow aperture through which proteins enter the nucleus, and which is filled with unstructured proteins. Small molecules can diffuse at random into the nucleus through the pore. Large molecules such as proteins, however, may be excluded from the nucleus completely, or, in contrast, they may enter but not leave it.

This is an example of the workings of ‘Maxwell’s demon’, a thought experiment that explains how the Second Law of Thermodynamics – which appears to imply that disorder must always increase – can be violated by imagining a tiny demon at a gate that only lets faster-than-average molecules through.

In the case of the molecular gate in the pore complex, only certain proteins that have been attached to another protein, known as an importin, are allowed into the pore. Lowe and his group bound quantum dots, which are fluorescent nano-particles that are small and bright enough to be visible when attached to a single molecule, to importin molecules, and tracked them as they moved through the pore complex. They found the pore complex channel to go through several stages in selecting cargoes. Most of the molecules are rejected before they enter the complex, others move into the channel before returning to the cytoplasm and only a relatively small fraction enter the nucleus. Nuclear entry requires energy; if energy is removed from the system a ‘gate’ at the bottom of the complex will remain closed.

It is possible to visualise the positions of all the molecules using a technique called single-molecule localisation microscopy (SMLM), in which the fluorescence signal is turned on in one small group of molecules at a time. This enables Lowe and his group to zoom out and look at the nuclei of thousands of cells (as at all the taxis in San Francisco), or, alternatively, to zoom in on a single channel. He used this technique to look at the distribution of proteins at the bottom of the channel through which cargo proteins enter the nucleus.

This structure is composed of tendril-like proteins that reach into the centre of the channel, and these proteins are known to be able to form a solid hydrogel under some circumstances. Lowe mixed them with an importin and showed that the proteins cross-linked to form a material that fell apart when energy was added.

This suggests a molecular mechanism through which the pore may open and close to let cargo into the nucleus. However, many of the details of the system are still unknown; he is developing ways to ‘zoom out’ and combine these images of the cell at the molecular level with larger-scale visualisation of cells that grow and divide.

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What can we learn from laughing?

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This post was contributed by Aline Lorandi, a visiting postdoctoral researcher under the supervision of Prof Annette Karmiloff-Smith, investigating the precursors of phonological awareness in Down Syndrome. Aline attended Dr Caspar Addyman’s recent event during Birkbeck’s Science Week

LaughterLaughter is one of the most well-known characteristics of babies, although greatly ignored by science. Motivated by this intriguing gap in the study of babies, Dr Caspar Addyman (Research Fellow from the Centre for Brain and Cognitive Development, Birkbeck) decided to invest on the research on baby laughter.

Dr Addyman quotes Victor Borge when he says that “laughter is the shortest distance between two people”. As laughter is one of the central characteristics of babies and a way to connect people, Dr Addyman’s interest in this sort of study is more than justified.

Maternity and paternity brings several challenges: fewer hours of sleep, loads of mess to organise, lack of time for the parents themselves or to work, their lives changed forever – although most of them would say, for the better. One of the greatest rewards for all those challenges in parenting is, undoubtedly, to hear their babies laughing.

“Baby laugh is appealing!” states Dr Addyman. It is present from the very beginning of life, and, historically, it can be tracked to non-mammals more than six-million years ago. It encourages social play, and it is also linked to tickling, which is as old as laughter itself, phylogenetically speaking.

Some researches on rats (like Weaver et al., 2004, published on Nature Neuroscience) show that rats whose mothers lick and groom them were less stressed, for the mother’s touch may be an answer to stress. From this, Dr Addyman argues that touching and tickling are very important for development.

Ontogenetically speaking, Dr Addyman maintains that laughter begins really early. Through a survey with parents, he found out that at three months of life, in general, babies give their first laugh (the first smile is at one month). According to Dr Addyman, laughing is more difficult than crying, for it requires more motor and voice control. When looking for how many laughs per day a baby gives, the number can be bigger than 150. And, of course, a guaranteed way for a laugh is tickling.

As to fun games and toys, Dr Addyman found that ‘peek-a-boo’ seems to be the best one. It also provides social interaction, as you have to wait for the other person to appear, and there is pleasure in doing that.

Naturally, at some point, children will realise that they can make parents laugh, changing the games. By this, Dr Addyman shows us that laughter is about social learning, and ‘peek-a-boo’ is a condensed form of this kind of interaction.

There is another important feature about laughing that distinguishes it from crying – it makes it a way for communication: While crying is a sign that something is wrong and must be stopped by parents, laughing points to something that they want to be continued.

As an argument for the social role of laughing, Dr Addyman presented research where he shows that children laugh more when in a group than alone, independently of how funny they think a movie is. Another experiment shows that laughter captures and holds attention from babies, and it is more ‘contagious’ than yawning!

Dr Addyman believes that we can learn from babies’ laughter. He says that we should challenge ourselves to be happy; for people who challenge themselves see more purpose in life. He also believes that we should do things with joy, be 100% in it, share with other people and simply be happy!

As Abraham Lincoln once said: “Most folks are about as happy as they make up their minds to be”. If this is correct, and babies can show us that it is, as Dr Addyman’s research points out, the answer to happiness is not ‘how to be happy’, but ‘how to change our minds’, remembering ourselves of the pleasures of tickling and laughing, as if we were still babies, and of the rewards of living a less stressful life, through the happiness of laughing out loud.

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