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UCL SCIENCE
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UCL Science
UCL SCIENCE
issue
for Schools and Colleges
for schools
and colleges
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Contents
Light forces
2
Extra copies of UCL Science
3
Watch your language
4
Is research funny?
6
Science Centre Lectures
7
Hair cells with spotty bottoms
8
The Physics and Astronomy
Outreach Project
9
Combining knowledge from cats
and dogs helps out humans
LIGHT FORCES
Susan Skelton and Dr Phil Jones,
UCL Department of Physics and Astronomy
Four hundred years ago, Johannes
Kepler, the German astronomer famous
for his laws of planetary motion, noticed
that the tails of comets always point away
from the sun, and suggested that sunlight
exerts a force on the nucleus of the comet
pushing the tail away from the source of
the light. Today we are able to use optical
forces in the laboratory as the basis for
some of the most sensitive instruments in
the world.
The force of light was first usefully
harnessed by Arthur Ashkin, a scientist
who worked at the Bell Telephone
Research Labs in the USA. He found
first that he could push microscopic
particles along a laser beam, and later on
that if the beam was tightly focused he
could hold them at a fixed point and
move them through three dimensions in
a microscopic version of the ubiquitous
science-fiction tractor beam, as shown in
Figure 1(a). For obvious reasons this
technique became known as ‘optical
tweezers’, and since then, the optical
toolkit has been expanded to include a
wide range of functions including
‘optical spanners’ for rotating, ‘optical
scissors’ for cutting and ‘optical stretchers’ for squeezing objects that range in
size from cells down through viruses to
atoms, and produced applications in a
variety of fields including biology,
medicine, and quantum physics.
But how can photons – mass-less
particles of light – be capable of exerting
forces on objects? The answer can be
found by considering a combination of
quantum mechanics which tells us that
light carries momentum, and classical
mechanics which gives us Newton’s laws
of motion.
10
Are we alone? Searching for
evidence
12
The Science Collections
14
UCL Year in Industry
Scholarships
14
Visit UCL - Open Days, Visits
and Events
15
Degree courses and UCAS codes
for 2011 entry
16
UCL (University College London),
Gower Street, London WC1E 6BT.
Front cover image - Oscar the cat, a
patient on the recent BBC1 television
series 'The Bionic Vet' with Dr Noel
Fitzpatrick.
Copyright - Dr Noel Fitzpatrick,
http://www.fitzpatrickreferrals.co.uk/
Figure 1. Optical Tweezers.
(a) A laser beam is focused to a small spot by a microscope objective lens, which can also be used to
observe the trapped objects. The inset shows the region around the focus and a microscopic
sphere that is attracted to the point of highest intensity.
(b) A ray of light (solid red arrow) is refracted as it crosses the microsphere. The transfer of
momentum from the sphere to the ray can be seen from the change in direction compared to an
unrefracted (dashed red arrow) ray, and occurs in the direction shown by the black arrow. The
force exerted by the ray on the sphere is therefore in the opposite direction to this.
(c) A line of microspheres is trapped by quickly moving the laser focus between three locations. The
sphere on the right is individually manipulated by moving its trap location towards the centre
and away again.
UCL Science
Consider what happens to rays of light
when they cross an object like the microscopic spherical bead or ‘microsphere’
suspended in water shown in Figure 1(b).
The microsphere has a different (higher)
refractive index to the surrounding
water, so it acts like a tiny lens: light rays
are refracted when they enter the microsphere, and again when they leave. The
microsphere has changed the direction
of the ray and therefore changed its
momentum by a small amount in the
direction shown by the black arrow. But
according to Newton’s third law an equal
amount of momentum must have been
transferred in the opposite direction,
from the ray to the sphere, that is, the
light exerts a force on the object. If we
sum up the effect of all the rays that
cross the sphere it turns out that the net
result is a force which is always directed
towards the point of highest intensity in
the beam, and so microscopic particles
are held where the beam is focused.
Just how big is this trapping force? In an
optical tweezers this is typically a few
pico-Newtons (1 pN = 1 x 10-12
Newtons). Considering that this is
around one hundred-billionth of the
weight of this magazine, it’s hard to
appreciate how this force could be significant. However, for objects a few microns
in size this force is strong enough to hold
them in an optical tweezers for several
hours. In Figure 1(c) you can see an
example of ‘tweezered’ microscopic
particles in one of our experiments.
In the UCL Optical Tweezers Group we
are interested in applying optical trapping
to new useful particles, as well as investigating new ways of using optical forces.
Together with colleagues in Cambridge
and Messina (Sicily) we have trapped
needle-like objects made from bundles of
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Figure 2. Optical Binding.
(a) A laser beam is reflected from the prism surface, but an evanescent field penetrates a short
distance above the prism where micro-particles are optically bound into chains as shown in the
inset. The whole experiment is viewed through a microscope.
(b) A photographs from our experiment showing optically bound 2 micron diameter spheres.
carbon nanotubes. Particles with dimensions smaller than 1 μm are difficult to
trap because the optical forces become
much weaker as the particle volume
decreases. Nanotubes have a radius of a
few billionths of a metre, but the bundles
can be several microns in length, thereby
helping to make the trap stable. We aim
to use these optically trapped needles as a
stylus for probing the structure of surface
on the nanometre scale.
We are also developing an alternative
form of optical trapping known as optical
binding. This method uses weakly
focused light reflected from the surface of
a prism as shown in Figure 2(a).
Microscopic particles are drawn into the
short-range but intense ‘evanescent field’
that exists above the prism. There they
self-organise into long chains or 2D
Extra copies of this issue can be
supplied on request.
Please write, or email, stating your
requirements to:
Admissions Enquiries,
UCL (University College London),
Gower Street,
London WC1E 6BT,
email: t.saint@ucl.ac.uk
arrays as can be seen in Figure 2(b). We
are investigating alternative ways of
generating optical binding by using
tapered optical fibres which could then
be applied to sorting and transporting
different kinds of microparticles.
Harnessing optical forces has lead to
many exciting scientific advances ranging
from assembling and controlling microscopic machines, to observing the action
of biological motors that drive your
muscles. With new applications being
discovered all the time, optical forces are
sure to shed more light on the microworld.
For further information please contact:
Dr Phil Jones, philip.jones@ucl.ac.uk
http://www.ucl.ac.uk/~ucapphj
http://www.opticaltweezers.info
UCL Science is published by UCL for the
Faculty of Life Sciences and the Faculty
of Mathematical & Physical Sciences.
Edited by Trea Saint, UCL Department of
Physics & Astronomy (t.saint@ucl.ac.
uk). Produced by The Drawing Office,
UCL Department of Geography (drawingoffice@geog.ucl.ac.uk). In association
with the UCL Schools & Colleges Liaison
Office.
4
UCL Science
WAT C H YO U R L A N G UAG E
Dr Mairéad MacSweeney,
UCL Institute of Cognitive Neuroscience
Research into sign language and the brain,
is shedding light on how the brain processes language in both hearing and deaf
people, as well as highlighting the importance of gaining language skills early in
life.
Most of us are born into a world of noise,
and even before birth the sounds of our
mother’s surroundings filter through to us
in utero. But for people born profoundly
deaf, there is no sound. They, and their
brains, develop in a silent world.
How does a brain that never receives
auditory input process language, and what
impact does deafness have on cognitive
development in general? These questions
are among those being investigated by
Dr Mairead MacSweeney, a researcher at
the UCL Institute of Cognitive Neuroscience. Most of what we know about
language development comes from studying spoken language. However, by looking
at sign language we can ask whether
particular brain areas respond to language
no matter how it is communicated, or if
the activation depends on whether words
are spoken or signed. The team uses
functional Magnetic Resonance Imaging
(fMRI) to investigate which parts of the
brain are activated as people process
language.
From these studies we know that the
brains of deaf people and of hearing
people process language in broadly similar
ways. For example, Dr MacSweeney and
colleagues have shown that deaf, native
signers (people who use sign language as
their first language) recruit the main
language centres in the brain, Broca’s area
and Wernicke’s area, when they are watching sign language: just as hearing people
do when they watch and listen to someone
speaking.
But there are some differences comparing
the brain activation between deaf and
hearing people too. There’s a lot more
movement in sign language than in watching someone speak, so the parts of the
brain sensitive to movement are more
active when you’re watching someone sign
than when you’re watching someone
speak.
Studies of profoundly deaf people can also
shed light on plasticity – the ability of the
brain to reorganise its function under
changed circumstances. Dr MacSweeney’s
team are investigating what happens to
the auditory cortex (the part of the brain
that processes sounds) if it doesn’t receive
auditory inputs early in life. They have
shown that, in people born profoundly
deaf, some parts of the secondary auditory
cortex are used to process visual input,
including sign language.
Rhyme and reason
Although British Sign Language (BSL)
and English seem very different, signed
languages share key linguistic features
with spoken languages (see box below). In
one study Dr MacSweeney and colleagues
looked at phonological awareness. This is
knowledge about the internal structure of
a spoken word. For example, knowing
that ‘cat’ consists of ‘C-A-T’ and that it
rhymes with ‘bat’.
Profoundly deaf people can’t rely on
hearing words to tell if they rhyme or not.
Dr MacSweeney and colleagues showed
English translation: The cat sat on the bed.
Frame 1
Frame 2
Frame 3
Frame 4
pictures of objects to deaf people and
asked them to say if the names of the
objects rhymed or not. Surprisingly, the
deaf people did better than expected,
getting more right than if they were
relying on guesswork. They seemed to
use a part of the brain called Broca’s area
(involved in speech production) more
than hearing people.
Why would this be? Well, to test if words
rhyme, hearing people conjure up an
‘auditory image’, something akin to
hearing the words in your head. The
researchers think that deaf people, unable
to do this, instead rely more on the
articulatory component (i.e. how you say
something).
Broadly speaking though, the brain seems
to process phonology the same way in sign
language and spoken language, for native
users at least, adding to the evidence that
the brain deals with all kinds of language
in a very similar way.
In development
Dr MacSweeney’s work is not focused
only on the brain pathways involved in
processing sign language, but she also
researches how being born deaf can affect
a person’s development.
Some 95 per cent of deaf people are born
to hearing parents. This can be a shock to
parents, who may have limited experience
communicating with deaf people, and
little or no knowledge of sign language.
Children in this situation may not have
full access to sign language and, even with
a cochlear implant or hearing aid, won’t be
able to access spoken language fully. This
can lead to what researchers call impoverished early language exposURE.
In some circumstances, deaf children
might not be fully exposed to sign
Figure 1. Stills from a British Sign Language
(BSL) translation of the English sentence ‘The
cat sat on the bed’. Also shown are BSL glosses
and a schematic representation of the location
of referents in sign space.
Frame 1: lexical sign BED.
Frame 2: classifier for BED (flat object)
located in sign space.
Frame 3: lexical sign CAT (note the iconic
nature of the sign, indicating the
cat’s whiskers).
Frame 4: classifier for CAT (small animal)
located on top of classifier for BED.
UCL Science
language until they start school – long
after their peers have become fluent in a
language. Since language is critical to
everything we do, if you don’t have robust
early language experience then all many
other skills are likely to suffer as a result.
Early diagnosis of deafness can also help
children gain exposure to an accessible
language. Steps in the UK have been taken
to make this possible. Since March 2006,
all babies in the UK have been offered a
hearing screen within a few days of birth.
Yet there is some evidence that, even after
early identification of hearing loss, there
can be gaps in the follow up services
provided.
Research suggests that learning a language
late can impair a deaf child’s subsequent
cognitive development. On average, a deaf
16-year-old leaves school with a reading
age of 10/11 years, despite having a nonverbal IQ no lower than average. Hearing
people tend to have around five years’
experience of spoken language before they
are faced with learning to read that
language. Profoundly deaf people don’t.
This means that have very little to map the
written language on to – making reading a
very difficult task.
However, research shows that learning any
language early could boost a child’s ability
to read. Deaf native signers tend to be
5
better readers than deaf non-native signers,
suggesting that learning even a different
language (including sign language) before
learning to read can help children read
better.
Dr MacSweeney and her colleagues are
continuing to investigate further the link
between learning sign language and reading English. She is also continuing to
study the neurobiology of sign language –
research that will boost our understanding
of how the brain processes language,
whether it’s spoken out loud or expressed
through actions of the hands and body.
Read the signs
It is a common misconception that British
Sign Language (BSL) is, basically, spoken
English with gestures. Lip-reading, reading and writing are all visual derivatives of
spoken English, but BSL is, in fact, totally
independent of spoken language.
Figure 2.
(i) Brain regions activated by British Sign
Language (BSL) sentence comprehension in
deaf native signers.
(ii) Brain regions activated by audio-visual
English sentence comprehension in hearing
non-signers.
Both language inputs were contrasted with a
low-level baseline: perception of the still model
and a low-level target detection task (visual for
deaf; auditory for hearing). Very similar
networks were recruited by both languages,
even though one is audio-visual and the other
is visual alone.
Other facts about sign language:
• Unlike spoken language, which is
expressed audiovisually, sign language is
conveyed in a visual-spatial manner,
relying on actions of the hands, upper
body and face.
• Deaf communities around the world use
sign languages that are mutually
unintelligible – e.g. British Sign
Language (BSL) is used in the UK,
while American Sign Language (ASL) is
used in the USA.
• Signed languages share many linguistic
features with spoken language, including those related to syntax (the rules for
constructing sentences), semantics (the
study of meaning) and phonology (the
study of sub-lexical structure of signs or
words).
For further information please contact:
Dr Mairéad MacSweeney,
m.macsweeney@ucl.ac.uk or visit:
http://www.dcal.ucl.ac.uk/ and
http://www.icn.ucl.ac.uk/
Adapted from an article by the Wellcome
Trust: http://www.wellcome.ac.uk/
News/2009/Features/WTX055554.htm
Figure 3. This is a sequence
of images from the British
Sign Language (BSL) sign
'SAW'. We show BSL stimuli
to our signing participants
while they are in the brain
scanner to determine whether
similar brain networks are
used to process signed and
spoken language, even though
they are delivered via very
different modalities.
6
UCL Science
IS RESEARCH
FUNNY?
Bright Club is run by UCL’s Public
Engagement Unit, who find new ways for
UCL staff and students to connect with
people from outside the University.
UCL is one of six Beacons for Public
Engagement, funded by the Higher
Education Funding Council for England,
the UK Research Councils and the
Wellcome Trust to change the way
Universities and members of the public
relate to one another.
Steve Cross, UCL Public Engagement Unit
For the past year UCL scientists have been
learning to perform stand-up comedy
about their research. Scientists have
performed alongside philosophers,
archaeologists and people from every
other discipline at Bright Club, the
University’s monthly variety night.
Bright Club happens
in a comedy club in
Clerkenwell, as well
as at comedy festivals
and UCL’s own
Bloomsbury Theatre.
Every month a professional comedian takes to the stage with
musicians and six UCL staff and students
to try and make an audience of members
of the public laugh until pub closing time.
Each event is themed, and the researchers
have tackled ideas like ‘Lust’, ‘Space’ and
‘Crime’ from loads of different intellectual
angles. Most of the people who perform at
Bright Club have never tried to be funny
on-stage before, but every one of them
pulls something brilliant out once they get
their first laugh.
Bright Club’s audience aren’t professional
scientists – they’re a normal comedy
audience, attracted by the chance to see
big-name comedians like Rufus Hound,
Robin Ince or Richard Herring alongside
our musicians and intellectuals.
Rufus Hound.
Bright Club has seen Dr Hugo Spiers
reveal that tying matchsticks to an ant’s
legs can help us understand the brain,
Prof David McAlpine share how awful
rock music sounds through a cochlear
implant and Dr Mark Westmoquette and
The Crowd from Bright Club: Food, at the
Wilmington Arms.
Every week the team behind Bright Club
release a free podcast, where you can hear
comedians and researchers, with anchorman Steve Cross, tackle the really big
questions in life: Does having your own
laser make you popular with girls? Should
you use a dog to clean your plates? If your
satellite crashes to Earth, who gets the
champagne bought for the launch party?
The podcasts are sponsored by the
Wellcome Trust.
To download free podcasts, buy tickets for
the Bloomsbury Theatre extravaganzas, see
pictures, or find out more go to:
http://www.brightclub.org
Strawberry and Cream perform at Bright
Club: Sea at the Sea Life Centre, Brighton.
For further information please contact:
Steve Cross, steve.cross@ucl.ac.uk,
Head of Public Engagement,
UCL Public Engagement Unit.
Dr Roger Wesson show how what we
thought we knew about the Universe is
much less than we now know we knew
about the Universe, and that we know
more than we used to know even though
we now think that we know less about the
Universe than we used to think that we
knew. Phew.
Other scientists performing have included
Dr Celia Morgan who compared the
dangers of horseriding and the use of
recreational drugs, Prof Peter Mullany
who explained why stripy icebergs are like
mugs you haven’t washed for a month,
Sheila Kanani who investigated the
possibility of surfing on Saturn’s moons,
and Tom Morgan who revealed what
dolphins really get up to when no-one’s
looking (hint: their cute reputation isn’t
fully deserved!).
Sheila Kanani, from the UCL Mullard Space
Science Laboratories.
UCL Science
7
Science Lectures for 6th Formers & Teachers
Autumn Term 2010
22 October
Computers Working at the Speed of
Light
Dr David Selviah,
UCL Department of Electronic &
Electrical Engineering,
UCL (University College London)
29 October
No lectures (school half-term) 5 November
What would Aliens look Like? And how Humans might Evolve if they colonise Space?
Dr Lewis Dartnell, Centre for Planetary Sciences,
UCL Department of Earth Sciences,
UCL (University College London) & Birkbeck, University of London
12 November
Engineering Structures II: Geometry in
Design 19 November
Antimatter, Positronium and their
Medical and Industrial applications Dr John Eyre, UCL Department of Civil, Environmental & Geomatic Engineering, UCL (University College London)
26 November
Supernovae and Gamma-Ray bursts: the Biggest Bangs from Stars
Professor Ian Howarth,
UCL Department of Physics & Astronomy,
UCL (University College London)
3 December
Geochemistry: Snowball Earth and
early Earth Evolution
Dr Graham Shields, UCL Department of Earth Sciences,
UCL (University College London)
7 December
Wormholes and Time Travel
Dr Roberto Soria, UCL Mullard Space Science Laboratory,
UCL (University College London)
7 December
Robots with Biological Brains and Humans with part Machine Brains
Professor Kevin Warwick, Cybernetics Research Group,
University of Reading
All are welcome, admission is free and
no booking or tickets are required.
Lectures, promoted jointly with the IoP,
are held on Fridays at 6.30 pm in the
Massey Lecture Theatre, UCL (situated
in-between the UCL students union
building and the Department of Physics
& Astronomy at UCL. Entrance from the
east end of Gower Place, off Gower
Street). Close to Euston rail & bus station
and convenient for the Underground.
Nearest stations are Euston Square and
Euston Station.
4th, 5th as well as 6th formers are
welcome. Students need not be accompanied by teachers. Parking facilities for
school buses are available, with prior
arrangement. Lectures last about an hour,
followed by a maximum of half an hour
discussion.
Dr Simon Brawley, UCL Department of Physics & Astronomy,
UCL (University College London)
More information and maps are available
on the following web-sites:
www.ucl.ac.uk/silva/phys/department/
science_centre
www.ucl.ac.uk/maps/
For further information please contact:
Dr Sadiq Kadifachi,
email: s.kadifachi@ucl.ac.uk,
or telephone Sophie Cross: 020 7679 7144.
www.ucl.ac.uk/science_centre
8
UCL Science
HAIR CELLS WITH SPOTTY BOTTOMS
information about different SPLs. In
particular, the calcium concentration
within IHCs was investigated.
Professor Jonathan Ashmore and Siân Culley,
UCL Ear Institute
Recent research at the UCL Ear Institute
has provided new clues into how the ear
encodes different sound pressure levels.
To obtain IHCs for the experiment,
cochleae – the small bones inside the head
containing IHCs – were dissected from
adult mice and then superglued to Petri
dishes. To expose the IHCs inside the
cochlea, sharp tweezers were used to pick
the bone away from the top of the
cochlea.
Sound is detected by hair cells in the inner
ear. These have nothing to do with hairy
ears, but instead get their name from tiny
hair-like protrusions from their surface.
The 'hairs' wave back and forth in sync
with sound waves entering the ear: this is
crucial for sensing sound. Inner hair cells, or
IHCs, have the vital function of converting the mechanical stimulus of a sound
wave, pushing against the hairs, into a
chemical signal. This chemical signal is
then transferred to nerve cells, or neurons,
in the auditory nerve, which pass information about the sound to the brain.
It is still unclear how the ear 'tells' the
brain about different sound pressure levels
(SPLs) – the property of sound expressed
in decibels (dB). The human ear, for
example, is capable of hearing over the
range 0-120dB. Each IHC has many
neurons contacting it, and one theory is
that there are two sub-populations of
neurons. It is thought that one sub-population sends information to the brain
about lower SPLs (for example 0-60dB),
while the other sub-population deals with
higher SPLs. At the points on the IHCs
contacted by neurons there are entry sites
for calcium ions. The entry sites, known as
channels, open and close according to the
Two techniques were required to study
calcium within IHCs. Firstly, there was a
method by which the voltage of the IHC
could be controlled, so that the effects of a
sound wave could be closely mimicked.
There was also a method for monitoring
the calcium inside the IHCs.
Cartoon representation of an IHC showing the
key features.
voltage of the IHC. When there is no
sound, the channels are closed. When
there is a sound, and the hairs wave back
and forth, the voltage changes and causes
the channels to open. This lets calcium
into the IHC and triggers release of
chemical messengers to the neurons.
Professor Jonathan Ashmore and Siân
Culley have performed experiments to
determine whether the IHCs themselves
could control which neurons receive
The mouse cochlea.
The left hand picture shows a mouse cochlea stuck to a Petri dish. The right hand picture shows the
same cochlea after the bone on the top has been picked away – the IHCs are found in the region
enclosed by dashed lines. Due to the size of the cochlea (2 millimetres), the dissection must be
performed under a low magnification microscope.
The IHC voltage was controlled using
electrophysiolog y. This involves puncturing a
small hole in the membrane of an IHC
using a small glass pipette containing an
electrode, creating a circuit between the
electrode and IHC. The voltage of the
IHC can then be controlled using a
computer.
There are dyes available for visualising
calcium: these emit light if they:
a) encounter calcium, and
b) are excited by light of a specific
frequency.
Dyes can be introduced into the IHC cell
body via the glass pipette. A high magnification microscope with a built-in laser
capable of exciting the dye can then be
used to view the fluorescence (emitted light).
The more intense the fluorescence, the
more calcium ions are present.
For each IHC studied, the following steps
were performed:
• The glass pipette was moved to the IHC
membrane;
• Once the pipette had punctured the
membrane, calcium dye entered the
IHC and the electrical circuit was
formed;
• The microscope was focused to the
bottom of the IHC (where the calcium
channels are found);
• The voltage of the IHC was changed,
mimicking the change which occurs
when the IHC is exposed to sound;
UCL Science
9
• D
uring this voltage change, the laser
scanned across the IHC bottom and the
microscope recorded the intensity of
dye fluorescence.
What was observed? Bright ‘hotspots’
were seen, where there was a large
increase in fluorescence intensity. This
indicates that calcium concentration
increases at specific points in the IHC.
There were 6-ß8 hotspots seen per IHC –
it is thought that these correspond to
clusters of channels. There appear to be
differences between the hotspots within
individual IHCs. Hotspots on one side of
IHCs showed a larger increase in fluorescence, due to more calcium ions, than on
the other side of IHCs.
Above: Calcium hotspots. The left-hand image shows where fluorescence intensity was increasing
during voltage change. The redder the spot, the more calcium present. The graphs show how two
hotspots (on different sides of the IHC) have different increases in fluorescence intensity. The period
when the IHC was subject to voltage change is shaded purple.
This presents the possibility that SPL
thresholds of neurons contacting IHCs
are controlled by the local calcium concentrations in the regions of the IHC
directly opposite the neurons. The low
threshold neurons could contact the
hotspots where there is more calcium
upon voltage change, and the high
threshold neurons could contact the
hotspots where there is less calcium.
A real IHC! An IHC filled with dye, which is
fluorescent due to the low concentration of
calcium which is always in the cell. The yellow
box indicates the part of the cell where hotspots
were found. 1μm is 1 micrometre, or onethousandth of a millimetre.
What is causing this difference in calcium
at different points on the IHC? Do neurons
on different sides of IHCs have different
thresholds? These are questions which
must now be answered by future research.
Funding contributions
from EuroHear and
The Physiological Society.
For further information about this project,
please contact: Siân Culley,
sianculley@gmail.com
Information about ongoing research at the
UCL Ear Institute can be found at:
www.ucl.ac.uk/ear
The Physics & AsTRONOMY Outreach PrOJECT
The UCL Physics and Astronomy department is committed to promoting science
in the wider community and encouraging
more students to study of science at school
and university. The department is engaged
in numerous outreach activities including:
• Talks by staff and students at local schools and speaking on all topics from cutting-edge research to what is it like to be a scientist.
• Numerous appearances in the media and press, including Prof. Jon Butter worth’s regular blog on the Guardian website. http://www.guardian.co.uk/
science/life-and-physics
• UCL Science Centre, a series of science lectures, demonstrations and talks aimed at sixth form students and their teachers. http://www.ucl.ac.uk/
phys/department/science_centre
• Running the High Energy Physics ​
masterclass for sixth form students and teachers to learn more about particle
physics. http://www.hep.ucl.ac.uk/
masterclass/
• Your Universe, the UCL festival of astronomy, which in 2010 ran from 15-17 October, which featured, exhibits,
demonstrations and popular lectures which were accessible to anyone.
http://www.ucl.ac.uk/youruniverse/
• Hosting the London leg of the Institute of Physics, Advancing Physics Road-
show for AS and A2 level students.
• Co-hosting the Institute of Physics, Physics in Perspective course for sixth formers and college students.
• Providing two-thirds of the scientists
featured in the Colliding Particles series of online documentaries.
http://www.collidingparticles.com/
• Initiating the LHC Sound project which attempts to ‘sonify’ the particles pro-
duced at the Large Hadron Collider
producing, thus turning fundamental particles into music.
http://lhcsound.hep.ucl.ac.uk/
If any schools are interested in the programme
of events, please contact: Dr Ryan Nichol,
rjn@hep.ucl.ac.uk - for further information.
10
UCL Science
C ombi n i n g K n owle d ge from
Cats and Dogs Helps Out Humans
Professor Gordon Blunn and
Dr Catherine Pendegrass, The John Scales
Centre for Biomedical Engineering, Institute
of Orthopaedics and Musculoskeletal Science,
UCL Division of Surgery and Interventional
Science
A recent BBC TV
series featured the
Bionic Vet (Dr Noel
Fitzpatrick) whose
first program was
about a cat who had his back legs severed
in a combine harvester. Noel was able to
reconstruct the cat’s hind legs by using
bionic implants which were developed,
designed and manufactured at the
Institute of Orthopaedics in UCL. The
two implants used for Oscar the cat were
the culmination of several years of
research into transcutaneous (skin penetrating) implants. These implants are fixed
into the bone and are referred to as
Intraosseous Trans-cutaneous Amputation Prostheses or ITAP for short.
Oscar was unique in as much as both of
his back legs were amputated and
reconstructed using ITAP technology
(Figure 1) however, two other patients of
Noel’s – dogs called Storm and Coal
(Figure 2), were really the pioneers of this
technology. These dogs both had amputation of the fore limb due to bone cancer
and were able to use an ITAP device in
the same way that Oscar did. In between
Oscar and Storm, a human patient was
treated with ITAP. This patient had her
arm blown off in the London bombings,
however she was unable to use a conventional stump socket prosthesis that are
usually used for amputees to attach an
artificial arm or leg. The implant that we
used for this patient was exactly the same
at the ones used in the animals’ only
slightly larger. ITAP revolutionised this
ladies life (Figure 3).
There are two important features of
ITAP: Unlike conventional stump socket
devices which load the soft tissues; leading
to rubbing and pressure sore development,
ITAP is anchored within the residual bone
and protrudes out through the skin at the
end of the amputation stump. This means
that load from the artificial limb bypasses
the soft tissues and is transmitted directly
through to the skeleton. This overcomes
the problems of tissue rubbing and pressure sore development which often leave
amputees unable to wear their artificial
limbs. However, the key to the ITAP
technology is the generation of the seal at
the skin implant interface which prevents
Figure 2. Coal the dog with an ITAP in his front leg together with a radiograph of the implant
in his radius and operative photographs. Note the implant has a porous flange which stabilises the
soft tissue adjacent to the skin and this creates a microbial seal at the interface.
Figure 1. Oscar the cat with two ITAPs in his
back legs.
bacterial migration into the body and
infection developing. Although dental
implants which are fixed into the mandible or maxilla are successfully used on an
everyday basis, these implants pass
through the oral mucosa which is composed of specialised cells and is not like
normal skin. In fact there are very natural
few examples of true transcutnaeous
structures. Horns and nails arise in the
surface layer of the skin and do not breech
it.
One of the few available examples that we
have based the ITAP concept on is the
deer antler. These are bony structures
which project through the skin and at
certain times of the year – the mating
season - are very heavily loaded. We found
that a unique feature of the deer antler
was the porous nature of the bone where
the skin formed a tight seal. Immediately
below the surface skin layer at the transcutaneous interface, fibres of collagen firmly
tether the skin to the antler bone, preventing the soft tissues pulling away from the
surface and creating an infection resistant
seal (Figure 4).
We have mimicked this in ITAP by
producing a porous collar coated with a
thin layer of hydroxyapatite which is the
calcium phosphate mineral naturally
found in bone. This seal can be enhanced
by using proteins such as laminin and
fibronectin, which are adhesion proteins
normally found in the human body and
serve to attach cells to the matrix which
constitute the tissues. We have chemically
bonded these proteins to the surface of
ITAP, where they promote the adhesion
of skin cells and reinforce the seal at the
transcutaneous interface (Figure 5).
We believe that using ITAP can improve
the outcome for amputees whether
UCL Science
11
human, cats or dogs. Having a stable
external prostheses attached to the body
means that in future it may be possible
to utilise the signals generated in the
severed and redundant nerves in the
stump to control the movements of an
artificial arm. If this were to happen then
Dr Fitzpatrick’s bionic patients would be
paradigm for ‘one medicine’ where
animals and man benefit from a shared
knowledge.
For further information please go to:
http://www.ucl.ac.uk/orthopaedics
UCL Division of Surgery &
Interventional Science:
http://www.ucl.ac.uk/surgicalscience
Right:
Figure 3. Photographs of the lady who had her
arm blown off in the July 2005 London
bombings showing a radiograph of the implant
inserted into her residual bone and the soft
tissue seal that subsequently formed.
Above:
Figure 4. Deer antler specimen showing with
the soft tissue removed and the porous nature of
the bone under the skin (arrow indicates the
skin interface). Collagen fibres positioned just
under the skin surface tie in the soft tissue to the
bone through these small pores.
Left:
Figure 5. Photo micrographs and Scanning
electron micrographs of dermal fibroblasts
grown for 1 hour on titanium surfaces that have
covalently attached fibronectin (upper two
pictures). The cells have been stained with
anti-vinculin which labels focal adhesion
plaques that indicate the regions of cell attachment. These are seen small bright regions
towards the margin of the cell. Cells are also
spread out over the surface of the titanium.
Compare this with fibroblasts on titanium
surfaces without fibronectin shown on the lower
two pictures.
12
UCL Science
ARE WE ALONE? SEARCHING FOR EVIDENCE
Alan Aylward,
UCL Department of Physics and Astronomy
We live in one of the most interesting
times there has ever been for answering a
fundamental question of science - are we
alone in the Universe?
The current spate of research on this topic
was initiated in 1995 when two European
astronomers announced that for the first
time they could prove there was a planet
going around another Sun-like star. The
star was 51-Pegasus and the planet was
named - rather unromantically - 51-Peg-b.
Unromantic or not this pointed the way
for others to start searches of their own,
and other detections soon followed. These
early detections were made by noting how
much a star wobbled back and forth in the
line of sight due to the planet going around
it - the motion was recorded in extremely
accurate measurements of the so-called
"Doppler shift" in the star's spectrum.
It was soon realised that another detection
method had even more potential - if there
were enough planets orbitting enough stars
out there, then some of them must occasionally pass in front of their star and so
dim the light from the star a little - this is
known as a "transit". What is more one can
look at many stars at once, continuously
recording the light from all the stars, and
so have a continuous survey of the field of
view. A number of ground based surveys
started - it turns out it needs only modest
telescope power.
Even the University of London
Observatory in Mill Hill where UCL
teaches its Astrophysics students the
principles of astronomy got in on the act
and, for example, published a paper
confirming the highly elliptical orbit of
HD80606b. Two satellites have been
launched to carry out surveys above the
distorting effects of the atmosphere CoroT from Europe and Kepler from the
USA.
The result of all this activity has been
impressive. At the time of writing - and
this will be out of date before this article is
even printed - there are around 500
catalogued planets seen and confirmed,
while the Kepler team have announced
another 700 awaiting confirmation.
An artist's impression of a Neptune-like exoplanet with rings, as seen from one of its satellites.
HR8799b - exoplanet 130 light years away, discovered in the HST archive (courtesy of NASA).
A Jupiter-like exoplanet as seen from the
surface of one of its rocky moons. Other moons
can be seen: if one was earth-sized could this be
a possible place to search for life?
(courtesy of PPARC).
An icy exoplanet far from its host star
(courtesy of ESO).
But the most exciting part of this work is
not in the simple detection and counting
of objects - not even in the fact we know
from the observations how large they are
and how far from their stars. The most
exciting part is that, because the light from
the stars of transmitting objects passes
around the planets and through their
atmospheres, we can start to measure the
properties of the planets: spectroscopy tells
us the composition of the planetary atmosphere. In fact we have found we don't even
have to have a transit to "probe" the planet
- the "light curve" (the way the light
reflected from the planet changes with the
angle it makes to us as it goes around the
star) tells us about its reflectivity and
hence about its surface and clouds - and
with the very best of measurements of the
infra-red light it emits even about its
atmospheric composition. All this information-gathering about the composition
and morphology of an exoplanet is called
"characterisation". UCL is at the forefront
of this science of characterisation of
exoplanets. Giovanna Tinetti in the UCL
Department of Physics and Astronomy
was the lead author on the first convincing detection of water vapour on an
exoplanet, the tongue-twistingly named
UCL Science
13
HD189733b. This detection relied on
another speciality of the department as it
used a comprehensive list of spectral lines
of water generated at UCL by Jonathan
Tennyson and Bob Barber. UCL has
stayed in the vanguard of such work with
detections of methane, carbon dioxide and
carbon monoxide using data from space
observatories like the Hubble Space
Telescope (HST) and Spitzer.
As this is being written a planet only 1.5
times the radius of the Earth has been
found in a nearby system which is known
to have 7 planets. The star is Gliese 581
and its planets hence called Gliese 581a to
581g. It is Gliese 581g which is the "superEarth". So now we know not only that
there are other planets out there, but also
that there are whole systems of planets
like our own solar system. Gliese 581 is a
red dwarf, rather unlike our own star but
55 Cancri, only 13 parsecs away in the
constellation of Cancer is a G8 star very
like our own and it is known to have at
least 5 planets. The biggest planets were
the easiest to find but now we are finding
smaller and smaller ones.
An artist's impression of the planetary system around the start 55 Cancri. We have found 5 planets
in this system to date, ranging in size from 3 times the mass of JUpiter to around that of Neptune
(courtesy of NASA).
By the time you read this we may have
found what many see as the ultimate goal
- an earth-sized planet, at the critical
distance from its star that would put it in
the "habitable zone", that is at a distance
from the star where liquid water could
exist on its surface. Gliese 581g is at that
sort of position. Now we want a planet
just a little smaller, and preferably around
a G-type star, and we have conditions as
near our own planet's as possible. By the
time you read this one may have been
found. The detection cannot be far off.
At that point our philosophical enquiry
about the possibility of life elsewhere in
the universe takes on a whole new
urgency. Maybe there will be many such
objects. But proving there are suitable
conditions out there does not prove life
actually exists there. We will need even
more evidence before we can start drawing definite conclusions. Spectroscopy will
be used to its limit to refine the characterisation, but who knows what new techniques might be used in future as we
home in on the answer to one of the
ultimate questions.
For further information please contact:
Professor A. Aylward, a.aylward@ucl.ac.uk,
Dr Giovanna Tinetti, g.tinetti@ucl.ac.uk
A complex exoplanet system: we see a Jupiter-like exoplanet with rings and companion satellites,
seen from a rocky moon outside the rings.
Image from Anglo-Australian observatory (courtesy of Chris Tinney) www.phys.unsw.edu.
14
UCL Science
THE SCIENCE COLLECTIONS
The Science Collections house a wealth
of scientific apparatus, equipment and
memorabilia pertaining to the various
scientists and their innovative work that
was conducted at UCL over the last two
centuries. Many were awarded the Nobel
Prize and their notes, instruments and
artefacts can be seen.
The collections are held either in their
particular department or housed collectively in a dedicated location. Physiology,
Electronic & Electrical Engineering,
Chemistry, Physics and Geomatic
Engineering each have collections, but
there is also the Galton collection, a
general science collection, and items such
as the original operating table that the
first anaesthetic was ever administered.
The collections are available for education and research visits.
Learning with the Science Collections
The collections are used by undergraduates, mainly in their respective
departments, and are shortly to be
integrated into new degree courses in the
Department of Science and Technology
Studies, UCL. The collections also
feature in exhibitions created by MA
Museum Studies students from the
Institute of Archaeology.
Researching in the Science Collections
The Science Collections are an excellent
resource for university groups outside
UCL who wish to use the material for
teaching practicals.
Enquiries from academics and researchers who wish to gain access to the
collection for study of particular objects
are also welcome.
These important collections demonstrate
the enormous contribution UCL has
made to the advancement of science at a
worldwide level.
The Geomatic Engineering Collection contains
the unique Thompson pin-hole plotter and the
Photogrammetric Society of Great Britain's
collection of all of Professor Thompson's
papers, blueprints and plans. Also within the
collection is a Zeiss Reg Elta Total Station,
together with further items associated with
Surveying and Photogrammetry.
The Chemistry Collection includes the Nobel
Prize Citation to Sir William Ramsay for his
discovery of noble gases. There is also the very
first X-ray photograph ever taken in Britain that
was used for clinical purposes, along with other
historic photographs and equipment dating
from the 19th Century.
The Physics Collection houses historic laboratory and experimental apparatus including
Sullivan's Universal Galvanometer, (c.1896) in
its original box with contemporary correspondence. There are items as diverse as photographs,
reflecting galvanometers and a vacuum
discharge tube.
Electrical & Electronic Engineering Collection.
At UCL in 1904, Sir Ambrose Fleming created
one of the most important inventions of the last
century - the Thermionic Valve. This led to the
invention of radio as a long range wireless
communication tool and marked the birth of
modern electronics. This collection also houses
Fleming's academic papers and items relating to
his long-term collaboration with Marconi.
The Physiology Collection includes published
papers from 1860’s, photographs and handbooks, 78 RPM gramophone records made by
Lovatt Evans, 16mm films, personal memorabilia, scientific apparatus, thermopiles and a
portable Halldane.
The Medical Physics Collection has been
recently taken in by UCL Museums &
Collection, it is awaiting documentation and
rehousing.
The Collections are only open by prior
appointment. Group visits are possible,
the collection spaces are suitable for up to
five visitors at one time.
www.ucl.ac.uk/museums/sciences
For more information, please contact the
Collections Manager, Jayne Dunn,
j.dunn@ucl.ac.uk, tel: 020 7679 2403.
UCL Year in Industry Scholarships
Offered by The Year in Industry to
students going to UCL.
Benefits
• A year's industrial work experience
• A salary of between £8,000 and
£12,000 per year
• Free comprehensive industrial
training courses
• Free industrial tutorial system
• Year's work normally qualifies as
relevant experience towards professional institutional membership
• High possibility of sponsorship at
university
• No cost or fees for the student relating
to industrial placement
• Free membership of Royal Academy of
Engineering educational continuum
throughout university and beyond
• Free student membership of relevant
professional engineering institute
• Membership of University of London
and UCL Student Unions including
travel, sporting facilities and student
societies
• Use of University of London
accommodation help service
• Invitation from relevant UCL department to interrelate with current
undergraduates and join departmental
social events
• Invitation to attend the UCL
extramural engineering lecture
programme
To Qualify
• Students must have an offer of a place
at UCL
• Students must obtain an industrial
placement via The Year in Industry
organisation
• Students must be European or have
relevant work permits
Further Information
• Look at The Year in Industry frequently
asked questions page:
http://www.yini.org.uk/faq.php
• Visit The Year in Industry website:
http://www.yini.org.uk
• Tel: 023 8059 7061, Email: info@yini. org.uk
UCL Science
15
VISIT UCL - OPEN DAYS,
VISITS AND EVENTS
UCL hosts and participates in a number
of events throughout the course of each
year which provide opportunities to meet
UCL staff, see around the institution and
learn about the study opportunities
available.
A number of departments are also able to
offer visits on an individual basis by prior
arrangement. Please contact individual
departments to see if this is possible.
UCL Freshers' Fayre.
information, please follow this link for
tour dates and further information:
http://www.ucl.ac.uk/prospectivestudents/access-ucl/open-days/
guided-tour-info/
Kangaroos in the UCL Quad on Australia
Day.
UCL Medical School Open Day
UCL Undergraduate Open Day
Thursday 30 June 2011.
UCL Tours
UCL is pleased to offer tours of the
campus by current UCL students.
The tours are primarily for prospective
students and their family members and
normally last approximately an hour and
a half, including an introductory powerpoint presentation.
Our next open day for undergraduates
will be held on Thursday 30 June 2011.
All UCL undergraduate departments will
be open to visitors with a variety of
information, talks and tours around
campus.
For tour dates and further information:
http://www.ucl.ac.uk/prospectivestudents/access-ucl/open-days/
guided-tour-info/
For more information, please follow this
link:
www.ucl.ac.uk/medicalschool/mbbsprogramme/open-days/
For further information check the Open
Day website at:
www.ucl.ac.uk/openday
Information about the Medicine MB BS
degree programme at UCL can be found
on our Undergraduate Prospectus website:
www.ucl.ac.uk/prospectus/medicine
University of London Open Days
You are welcome to visit UCL on any
weekday between 10.00 am to 4.00 pm
and follow our self-guided tour; simply
print out the web page with map and
tour route, then visit UCL and
follow the tour route as shown.
Dates tbc.
The Medical School will run an Open
Day for prospective Medical School
students during the spring and summer
terms.
Mini Medical School Open Days
Dates will be announced at the
beginning of 2011.
In addition to the Medical School Open
Days, we are offering 'mini' Medical
School Open Days for prospective
Graduate-entry students and prospective
Undergraduate-entry students. For more
Dates tbc.
UCL takes part in the University of
London Open Days. The events are held
at Senate House, Malet Street, London,
WC1E 7HU.
No booking is necessary. For more information please visit:
www.london.ac.uk/openday
To download a map and find location
details, please visit:
www.london.ac.uk/map
Campus Self-Guided Tours
If you wish to visit a specific academic
department, you will need to contact
them directly to enquire whether this is
possible. Contact details for departments
can be found via the Undergraduate
Prospectus.
For further information please contact:
Study Information Centre,
UCL Department of Educational Liaison,
University College London,
tel: 020 7679 3000.
UCL Science
16
UCL FACULTIES OF MATHEMATICAL & PHYSICAL SCIENCES AND LIFE SCIENCES
BSc and MSci DEGREE COURSES AND UCAS CODES FOR 2011 ENTRY
**for Faculty of Engineering Sciences please see:
http://www.ucl.ac.uk/prospective-students/undergraduate-degrees/engineering-sciences/index.shtml
MATHEMATICAL & PHYSICAL SCIENCES Chemistry
Statistical Science
F100
G300
BSc Statistics
BSc Chemistry
F101MSci Chemistry
G305MSci Statistical Science (Intl. Prog)
F105MSci Chemistry (Intl. Prog)
GN32
BSc Statistics and Management for Business
F320
LG13
BSc in Economics and Statistics
F323MSci Chemical Physics
GLNO
BSc Statistics, Economics and Finance
F150
GLRO
BSc Statistics, Economics and Language
BSc Chemical Physics
BSc Medicinal Chemistry
F153MSci Medicinal Chemistry
F1G1
Earth Sciences
F1GCMSci Chemistry with Maths
F600
BSc Geology
F1N2
F601MSci Geology
BSc Chemistry with Maths
BSc Chemistry with Management
F1NFMSci Chemistry with Management
F641
F1R9
F646MSci Palaeobiology
BSc Chemistry with European Language
BSc Palaeobiology
F1RXMSci Chemistry with European Language
F644
F645MSci Environmental Geoscience
BSc Environmental Geoscience
Physics & Astronomy
F660
F300
BSc Physics
F663MSci Geophysics
BSc Geophysics
F303MSci Physics
F522
F340
F523MSci Planetary Science
BSc Theoretical Physics
F345MSci Theoretical Physics
F510
BSc Astrophysics
F511MSci Astrophysics
BSc Planetary Science
F605MSci Earth Sciences (Intl. Prog)
F603
BSc Earth Sciences
F604MSci Earth Sciences
Mathematics
G100
BSc Mathematics
G107MSci Mathematics
G1F3
BSc Maths with Theoretical Physics
ENGINEERING SCIENCES**
Medical Physics & Bioengineering
G1FHMSci Maths with Theoretical Physics
F351
G1L1
F350MSci Medical Physics
BSc Maths with Economics
BSc Physics with Medical Physics
G1LCMSci Maths with Economics
G1T9
BSc Maths with Modern Language
G1TXMSci Maths with Modern Language
G1N2
BSc Maths with Management Studies
G1NFMSci Maths with Management Studies
GF13
LIFE SCIENCES
Please see: http://lifesciences-faculty/degree-programmes/#ugdp
BSc Maths and Physics
GF1HMSci Maths and Physics
GG13
BSc Maths and Statistical Science
GGC3MSci Maths and Statistical Science
CLINICAL SCIENCES
A100MB BS BSc Medicine (6 years)
Science & Technology Studies
V550
BSc History and Philosophy of Science
V551
BSc History, Philosophy and
Social Studies of Science
P990
BSc Science Communication and Policy
L391
BSc Science and Society
B610
BSc Audiology (4 years)
Natural Sciences
CFG0
BSc Natural Sciences
FGC0MSci Natural Sciences
UCL (University College London), Gower Street, London WC1E 6BT.