Throughout our lifetime our bodies sustain infections and injuries, and the body deals with them by mediating an inflammatory response. This happens by cells within our blood entering the site of infection or injury and carrying out multiple biological reactions. These reactions can kill the microorganism that has caused the infection, but also heal at the site of injury, and hence resolve inflammation. These blood cells are collectively called white blood cells or leukocytes, and there is one in particular, named the neutrophil, which not only helps to resolve inflammation but can also exacerbate the condition further. This has resulted in the neutrophil having a reputation for being both ‘good’ and ‘bad’ in inflammatory conditions.

The reputation of the neutrophil is influenced by many molecules that are released from other cell types during inflammation. These molecules influence the activity of the neutrophil in various ways, either stimulating the cell so inflammation can be resolved or inhibiting a particular function the cell has. The influence of these molecules determines whether the neutrophil is able to carry out its functions efficiently or whether the inflammatory condition will be aggravated further. The biological activities of neutrophils therefore need to be understood to comprehend how they function and how these roles can be modulated to determine what effect this has during an inflammatory response.

Neutrophils form part of the body’s innate immunity which involves a series of defence mechanisms that protect the host from infection and form the early barriers to infectious diseases without relying on the production and expansion of antibodies that form the adaptive immune response. When an infection occurs, the innate immune response is triggered to rapidly detect and destroy the infection. Neutrophils are one of the first blood cells to respond to infection and are recruited from the circulating blood into the tissue by molecules called chemoattractants¹. These molecules, released from cells at the site of infection and also from the microorganism, also known as a pathogen, provide a chemical gradient for neutrophils to migrate along, with the highest concentration of these chemoattractants situated at the site of infection, so the cells are led directly to the infected site. Once in the tissue the lifespan of the cell is increased to approximately 1-2 days as opposed to 6-10 hours in the circulation. This is to lengthen the amount of time neutrophils have to carry out their functions and resolve inflammation.

A vital part of the innate immune response is the ability of the neutrophils to engulf pathogens and aid the resolution of infection. This process is called phagocytosis and classifies the neutrophil as a phagocyte, so called after the Greek for ‘devouring cells’. When the neutrophil has entered the infected site and detected the pathogen, the outer membrane of the neutrophil surrounds the pathogen to engulf it and so the pathogen becomes taken up into the cell. Neutrophils contain many granules and these are packed with lots of toxic reagents. Upon engulfment these granules fuse with the pathogen and release their toxic contents, by a process called degranulation, and these contents assist in the killing of the pathogen².

In addition to degranulation, neutrophils can also kill pathogens by oxidative mechanisms, so called because molecular oxygen is required. This involves a process named the respiratory burst and it is the major mechanism by which neutrophils kill and digest pathogens. During the engulfment of a pathogen into the neutrophil, molecular oxygen is also rapidly taken up. The oxygen is then converted, by a series of chemical reactions, into several toxic compounds such as hydrogen peroxide. Further chemical reactions may occur producing even more potent substances³ and when the pathogen becomes exposed to these various toxic oxygen metabolites the pathogen is digested and destroyed within the cell.

Neutrophils have also been shown to kill pathogens outside of the cell, i.e. extracellularly, rather than engulfing them. This occurs by neutrophils releasing web-like structures of genetic material, called neutrophil extracellular traps (NETs)⁴. These NETs are composed of fibres that trap pathogens, and have been proposed to contain high concentrations of anti-microbial compounds, such as those contained within their granules, to kill pathogens and prevent the spread of infection. Some bacteria, however, have evolved to counteract being killed by NETs by producing substances that degrade the genetic material that make up NETs, such as Streptococcus pneumoniae⁵, which is known to be the common cause of pneumonia.

Once the pathogens have been dealt with, and to completely resolve inflammation, neutrophils need to be cleared from the tissue. If the cells do not become removed then all their toxic contents, such as the granule contents and oxygen metabolites that kill pathogens, may leak out of the cell and damage surrounding cells and tissues, which will only make the inflammatory condition worse. For removal, neutrophils firstly need to die. This is by a programmed type of cell death termed apoptosis⁶ which ensures that the cellular membrane remains intact so these toxic contents are retained within the cell and cannot be released. During this cell death a fatty (lipid) molecule called phosphatidylserine is flipped to the outer surface⁷. This lipid acts as a signal for tissue macrophages to target the dead neutrophil. Tissue macrophages are another class of white blood cell with a vital role of recognising apoptotic cells. Once the signal has been recognised, the neutrophil itself is then engulfed by the macrophage and cleared from the tissue. It is essential that these apoptotic cells are removed efficiently from the tissue because a delay in their clearance can also increase the chance of their intact membranes becoming leaky.

Apoptosis is therefore a process which needs to be tightly regulated to ensure inflammation is resolved efficiently. If cell death is stimulated too early then the number of functional neutrophils in the tissue is reduced. This would limit the hosts’ ability to fight infection and resolve inflammation. For example, some infections induce neutrophil apoptosis, such as the influenza A virus⁸ and the Pseudomonas aeruginosa bacterium⁹ to favour their own survival. In contrast to this, if apoptosis is delayed, as seen with the inflammatory joint disorder rheumatoid arthritis¹⁰, the number of circulating cells in the tissue increases, toxic contents may then be released from the cells, and surrounding tissue would be damaged potentiating inflammation further. This contrasting effect of the neutrophil is often referred to as the ‘double-edged sword’ effect, i.e. can be both ‘good’ and ‘bad’ during the inflammatory process, with the damaging effects of the neutrophil quickly out-weighing the benefits. Although neutrophils may often appear to be the ‘bad’ guy in certain inflammatory conditions this is typically due to the influence of other molecules released from surrounding cells. Without this influence the primary aim of the neutrophil is to resolve inflammation, making them overall the ‘good’ guys of the inflammatory process.

References:

1. Yoshimura, T., Matsushima, K., Tanaka, S., Robinson, E.A., Appella, E., Oppenheim, J.J. and Leonard, E.J. (1987) Proc. Natl. Acad. Sci. USA 84, 9233-9237
2. Campanelli, D., Detmers, P.A., Nathan, C.F. and Gabay (1990) J. Clin. Invest. 85, 904-915
3. Albrich, J.M. and Hurst, J.K (1982) FEBS Lett. 144, 157-161
4. Brinkmann, V., Reichard, U., Goosmann, C., Fauler, B., Uhlemann, Y., Weiss, D.S., Weinrauch, Y. and Zychlinsky, A. (2004) Science 303, 1532-1535
5. Beiter, K., Wartha, F., Albiger, B., Normark, S., Zychlinsky, A. and Henriques-Normark, B. (2006) Curr. Biol. 16, 401-407
6. Kerr, J.F., Wyllie, A.H. and Currie, A.R. (1972) Br. J. Cancer 26, 239-257
7. Fadok, V.A., Voelker, D.R., Campbell, P.A., Cohen, J.J., Bratton, D.L. and Henson, P.M. (1992) J. Immunol. 148, 2207-2216
8. Colamussi, M.L., White, M.R., Crouch, E. and Hartshorn, K.L. (1999) Blood 93, 2395-2403
9. Usher, L.R., Lawson, R.A., Geary, I., Taylor, C.J., Bingle, C.D., Taylor, G.W. and Whyte, M.K.B. (2002) J. Immunol. 168, 1861-1868
10. Ottonelo, L., Cutolo, M., Frumento, G., Arduino, N., Bertolotto, M., Mancini, M., Sottofattori, E. and Dallegri, F. (2002) Rheumatol. 41, 1249-1260

Who was Kepler?

Any talk about the Kepler mission should mention the man it was named after. Johannes Kepler was a mathematician, astronomer and astrologer born in Germany in the 16th Century. He is most well known for his planetary laws of motion which explain the elliptical shapes of orbits and the speed of planets at different distances from their star. These laws also formed an early basis for Isaac Newtons universal law of gravitation.

Kepler Mission

The kepler mission is one focused on the search for extrasolar planets. The telescope in itself is a 0.95m telescope which aims to detect light rather than produce images like traditional telescopes. It has an unnaturally large field of view which allows it to observe around 100,000 stars for the life of the mission. Although some of the measurements could be made on earth the telescope is space based to allow continuous monitoring of stars so day/night cycles have no effect, also atmospheric and seasonal effects have no impact on the measurements and the accuracy of the observations.

Aims and Methods

The main aim of the Kepler Mission is to find planets outside of our solar system it does that by looking for the transit of planets across the face of a star it is orbiting. The scientific analysis of these planets relate to another aim by which the mission is to explore the structure and diversity of planetary systems. By surveying large numbers of stars the mission can also determine the percentage of terrestrial and larger planets that reside in a habitable zone, it can determine size distributions of the size and shapes of planets, estimate number of planets in multiple star systems.

By observing the intensity of light coming from distant stars the mission looks for reductions in the intensity which would be inherent with a planet passing between the star and the telescope. The mission looks for periodic reductions in this signal which is associated with the orbits of planets which, if like our solar system would be of a regular orbital period. The image above shows two examples of light curves used in the transit method, the above shows a regularly orbiting planet shown by the dips in intensity, the second shows potentially two planets in a system.

Kepler’s Discoveries

Since launch the Kepler observatory has made around 61 confirmed discoveries with many more light curves being analysed daily for potential candidates. Out of these discoveries some have received reports in the media due to their potential scientific impacts and interesting properties.

Kepler 22-b was a significant discovery made in December 2011 which was that of a nearly Earth sized planet. Prior to this discovery a number of Earth sized planets had been discovered however, to make things different Kepler 22-b was discovered in what is deemed the habitable zone around it’s star making it a true Earth like planet. Another, that of Kepler 16-b was reported due to it being the first planet orbiting a 2 star system to be seen. With this many drew comparisons between it and the planet of Tatooine from Star Wars!

The Future of Kepler

Kepler space observatory is very much still in it’s infancy so many many more discoveries of vastly different planetary systems are sure to be made. However, one thing that is holding back discoveries is the sheer number of star systems being observed and the limited amount of astronomers on the project. There is a way though in which the public can help. A website has been set up called Planet Hunters which shows light curves and encourages the public to help look for planetary candidates by marking on them variations in the light curves, so give it a go at the link below.

http://www.planethunters.org/

A molecule that is known to take up cholesterol into a cell has recently been identified to allow entry of the hepatitis C virus (HCV) into liver cells. This may lead the way for new therapies to be developed.

Hepatitis C is a disease that primarily affects the liver. It is caused by HCV, which is spread by blood-to-blood contact. Once infected, HCV can persist in the liver causing scarring and ultimately leading to liver failure or cancer. The World Health Organisation (WHO) estimates that three per cent of the world’s population (about 170 million) have hepatitis C, and although treatment is available, more effective therapies are needed. Liver transplantation is one such treatment, but infected patients find the virus attacks the new liver.

Previous studies have shown the involvement of cholesterol in HCV infection, thus it was hypothesised by researchers at the University of Illinois at Chicago that a cell surface molecule (a receptor) called Niemann-Pick C1-like 1 (NPC1L1), which is known to facilitate the uptake of cholesterol into the cell, may also be involved in trafficking the virus into the cell.

The research team headed by Susan Uprichard, assistant professor of Medicine, Microbiology and Immunology, conducted experiments to determine the role of NPC1L1 on viral uptake. Experiments involved blocking the receptor and reducing expression by using knock-out models. The results demonstrated that blockade or knock-out of NPC1L1 impaired liver cell infection with HCV.

To confirm these studies further, an inhibitor of NPC1L1 called ezetimibe, which is clinically used to lower cholesterol levels, was also tested. Results validate previous findings showing blockade of HCV uptake into the cells and preventing infection.

Current drugs used to treat hepatitis C are known to be toxic, and cannot be used by transplant patients, therefore ezetimibe may provide a solution as a new anti-hepatitis agent. Therapy with ezetimibe alone or in combination with current drugs may improve patient treatment by targeting the receptor NPC1L1 and preventing HCV entry into liver cells.

Reference:
Sainz et al, (2012) Identification of the Niemann-Pick C1-like 1 cholesterol absorption receptor as a new hepatitis C virus entry factor. Nature Medicine. Ahead of print.

The paper can be found at: http://www.nature.com/nm/journal/vaop/ncurrent/pdf/nm.2581.pdf

No I’m not referring to Highlander I am referring to species of humans. Out of many species that fall under the umbrella term of the genus Homo we are the only one that has survived- Homo sapiens. The mystery behind this has had religious, philosophical and scientific ramifications over the ages that have been debated to this day. But who were these other humans? And can we really consider them to be human?

From the archaeological record we know a fair bit about these other humans which may be able to tell us just how human they were by identifying sociality, intelligence, technology and culture.

Robin Dunbar found a relationship between a part of the brain known as the neo-cortex and theory of mind. Theory of mind refers to a level of sociality- the first level dictates that person A knows something about person B. The second level dictates that person A knows that person B knows something about person C; and so on. Therefore the higher the level, the higher the capacity for an individual to comprehend what a group knows. This type of intelligence becomes important when we start to consider how a group functions within a landscape; they form social bonds which is crucial for group activity. Seeing this hallmark within primates, Robin Dunbar extrapolated the size of the neo-cortex within extinct humans from archaeological remains, and use it to infer upon theory of mind and sociality. What he found was a general clumping of all the extinct Homo species around the Homo sapiens mark. The lineage that led to the genus Homo diverged 6 million years ago from chimpanzees. The first Homo species that appeared on the scene was Homo habilis at 3 million years ago. It is very likely that by then, H. habilis had the intelligence to understand social situations.

While H. habilis was the first Homo species to make and use tools (which led to their alternative and rather informal name Handy Man), Australopithecus afarensis was actually the first species to do so. A. afarensis was an earlier species that walked on legs as opposed to knuckle-walking, and it is possible that the Homo lineage came from this species. The earliest evidence of tool use on bones comes from Ethiopia dated at 3.39 million years ago where it is known that A. afarensis inhabited this region. Clearly by the time of H. habilis, we start to see the beginnings of a rather primitive form of intelligence that enabled them to form social groups and use their own type of technology, which was known as the Oldowan tool industry.

Eugene Dubois, a Dutch palaeo-anthropologist, was in Java (S.E Asia) in 1890 when he found a set of skeletal remains. He had found what was later called Homo erectus. This species was clearly the first member of the Homogenus to have migrated out of Africa. One of the most important finds belonging to this species was Nariokotome Boy found in Kenya in 1984. What was particularly interesting about this find was that the individual was thought to be just a little bit older than 11 years old and, from his remains, it could be seen that he was about 6 foot tall! This is a species that was very well adapted to the hot climate of Africa; H. erectus was tall, gracile and slender with long legs that enabled them to travel for long distances, which ultimately they did.

To perfectly complement how H. erectus was adapted to the hot climate of Africa, H. heidelbergensis illustrates adaptations to a cold climate. Likely to diverged from H. ergaster as well (and thus be a sister group to H. erectus), H. heidelbergensis was the last common ancestor of Neanderthals and modern humans. But it was also the first Homo species to move into Europe. The commonly held theory is that H. heidelbergensis evolved into Neanderthals in Europe. As such Neanderthals appeared to be very well adapted to the cold; they were short, stocky and well-built when compared to the tall and more graceful modern humans.

They had a wide distribution across Europe and Asia; from Israel to Wales, and as far north as Siberia and south as Gibraltar. Vast amounts of archaeology have shown that Neanderthals had their own culture and technology, and existed together in their own social groups. But all good things come to an end. By the time the Neanderthals had settled into their life in Europe, at 60,000 years ago, the climate got severely worse. Before the start of the Ice Age at approximately 28,000 years ago, modern humans had already arrived and settled themselves, and the Neanderthals had become extinct.

The arrival of modern humans into Europe from 50,000 years ago is part of the next hallmark in our evolution: the Upper Palaeolithic Revolution. This revolution saw a cultural explosion. A wide variety of art has been attributed to the Upper Palaeolithic. Such examples include ornaments, figures and cave art, but it also included technology for acquiring and processing food. While the Neanderthals had their own technology for the same reasons, modern humans had a much more diverse toolkit. But as far as we know, no art found has been associated with Neanderthals.

In 2010, DNA analyses suggested that Neanderthals and modern humans interbred just outside of Africa before modern humans spread around the world. Following on from this, a few other studies have suggested that interbreeding was occurring between other human species, such as between H. erectus, and a possible new human species the Denisovans, and between modern humans and the Denisovans. While many more analyses need to be done to confirm this, this claim has immediate implications as to what we consider a species. A species is defined as a group of individuals that can only reproduce with each other. If Neanderthals and modern humans were interbreeding with each other, then this suggests that Neanderthals and modern humans are the same species, and that we (current modern humans) are descended from this interbreeding. More work however needs to be done. Ancient DNA is a field fraught with difficulties but as DNA technology improves we will have more data to look at.

By now we see a picture emerging as what we could consider as “being human”: the capacity for sociality and intelligence, use of technology and the element of culture. At the same time the lines between these various humans are beginning to blur. If the DNA evidence holds up, as more studies are carried out, then perhaps we should start to consider all of these humans under just one species name and designate each one by sub-species. The archaeological evidence certainly suggests that many of these types of humans had a level of intelligence that meant they could establish technology and culture which appears to be just as different from each other as they are morphologically. We are so willing to find the point in time where we can say “here is where we became human!”  The truth is we can’t. We, Homo sapiens, may have arisen around 200,000 years ago, but humanity could have begun much earlier. So when natural selection and bad luck killed off the other types of humans, it left us- the sole human survivor. This then leaves us with just one question:

For how long, in this changing world, can we survive?

For more information:

• Dunbar, R. 2003. The Social Brain: Mind, Language and Society in Evolutionary Perspective. Annual Review of Anthropology 32, 163-181
• Green et al. 2010. A Draft Sequence of the Neandertal Genome. Science 328 (5979) 710-722
• Stringer, C. Andrews, P. 2005. The Complete World of Human Evolution. Thames and Hudson, UK.
• Oppenheimer, S. 2004 Out of Eden. Robinson, London

This article was written to complement the presentation “Ancient Humans: Who were they? And who got it on?” that was given on the 5^th December 2011 for the Natural History Society. For more details on the author, see http://independent.academia.edu/DanaeDodge

One of the physics stories this year that made it’s way significantly into the
media was that from the OPERA collaboration which observed Neutrinos travelling
faster than the speed of light. When this report broke back in September it was
met with a certain amount of trepidation from both the scientists involved and
the scientific community with the possibility that if confirmed it is a result
that would put ends to the underpinning concept of general relativity that
nothing can travel faster than the speed of light! In the months up to now the
scientists involved have been running the experiment again with the same results
and offering the challenge to other scientist to try and see what is wrong with
their experiment/result.

Currently although it hasn’t been able to be disproved the likelihood of this
being correct is low, one only has to apply the apparent difference in neutrino
and light speeds to the supernova of 1987. Under the OPERA speeds we should have
detected neutrinos from supernova 1987a 4 years before the light arrived, this
however wasn’t the case and they more or less arrived at the same time. The jury
is still out on this one and it’ll be interesting to see what experiments are
devised in 2012 to test these results.

Hints of Higgs.

In December CERN held a press conference regarding the Higgs Boson with much
excitement surrounding it. The rumours and speculations as to what results were
to be announced seemed to mirror most people’s hopes of the conference, that the
Higgs had finally been found at the LHC, this however was not necessarily the
case. Scientists at CERN couldn’t specifically say they had found the Higgs
Boson with significant certainty, however two experiments (ATLAS and CMS) had
seen hints of what was believed to be a Higgs signal around 125
gigaelectronvolts.

Although from experiments it cannot be stated if the Higgs exists or if the
signal observed is true 2012 holds hopes for the scientists involved. When the
LHC gets back up and running after the Christmas break scientists will be
hunting and acquiring as much data as possible to identify with significant
certainty where the Higgs signature lies. Expect by the end of 2012 to have an
answer as to whether the Higgs Boson exists!

The end of the Shuttle Program.

July brought the end of NASA’s 30 year shuttle program with the successful
launch and return of shuttle Atlantis. Funding strains and austerity measures
introduced by NASA grounded the fleet after 135 missions which brought massive
rewards into space research and technology developments. Sadly however measures
put into action in the period after the Columbia shuttle tragedy has seen NASA
aiming to shift it’s regular space travel to that of private investors to save
the limited amount of money already received from the US government. 2012 is
expected to see the first private companies staking claims in space exploration
with private space craft making the launch into space in the coming months.

Fukushima Fallout

It was hard to miss coverage of the events that took place on the East coast of
Japan back in March where a country best prepared for a tsunami was overwhelmed
by the result or 9.0 magnitude Earthquake.Luckily most of the nuclear fallout
was carried out to sea by winds although this didn’t stop mandatory evacuation
zones around the reactors. It took 9 months from the initial reactor meltdowns
to ensure that the reactors were safely in cold fusion and accordingly shut down
although the clean up of the site will take decades still at high cost.

The fukushima meltdown had significant effects on research and energy policy in
some nations. Compared to the Chernobyl disaster (occurring 25 years previously)
researchers could assess how a release of radioactive material effected the
environment and occupants in a wealthier nation such as Japan. The research also
aided the Japanese people with the lessons learnt previously from Chernobyl
being applied to prevent conditions caused by radiation. The disaster also had
an impact on policy with (understandably) Japan, Germany, Switzerland and Italy
taking an abrupt turn away from nuclear, Germany proposing to shut down all
reactors by 2020s. The coming years will be interesting to see if other
technologies come through for energy production or if these nations resume their
faith in nuclear energy.

The growing Universe

This years Nobel prize in Physics was awarded in October to Saul Perlmutter,
Brian Schmidt and Adam Reiss for their work on using supernovae to chart the
expansion of the universe. By using distant supernovae with standard intensity
the team were able to chart from their light how far away and how fast the
points were moving away from us on Earth. From this deductions and calculations
of the universe’s expansion could be ascertained as well as inferences made for
the effects of dark energy on matter in the universe. This year’s Nobel prize in
Physics was an odd one as the lauretes were relatively young compared to many
that have come before indicating potential shifts in those taking up scientific
research.

New Earths

2011 was an extraordinary year for NASA’s Keplar mission encompassing ground and
space based telescopes in a search for extrasolar planets. Although there was no
sign of Earth’s twin exactly, over 700 planets have been identified with some
strong candidates that may contain life. The mission identifies planets by
looking at stars. Measurements map out the light intensity observed from these
stars, periodic reductions in this intensity are sometime observed and it is
this which indicates that there is a body orbiting with a defined orbit. This
can data can also be applied in such ways to calculate the size of planets and
other properties.

Notable mentions of planets discovered by the Keplar mission are ‘Keplar 22-b’
which was the first planet observed which was inside of the habitable zone, a
region around a star where life may exist. Another one was a planet orbiting two
suns which was aptly named Tatooine.

To boldly go…

In November 6 men returned to Earth from a mission to Mars, however they never
actually left the Earth. The simulated mission that took place in a Russian
warehouse came to an and proved to a point that the human body could at least
cope with the mental strain of isolation and close quarter living that would be
encountered on a manned mission to Mars. Whilst locked away in a mock space
craft the astronauts practised space walks, experiments on mars and simulated
repairs necessary to keep the craft going. This paved the way for future space
exploration and although a Mars mission won’t occur just yet it’s a tantalising
glimpse into what may be possible in regards to the human body.

Goodnight Tevatron.

As the LHC was colliding particles and obtaining data to probe into the origins
of the universe and evidence for the Higgs Boson, an older particle accelerator
came to the end of it’s functioning life. With over 25 years colliding particles
Fermilab’s Tevatron particle accelerator closed in September with most of the
scientists using it packing up to move to the bigger and more powerful LHC.
Although not as powerful, Tevatron was actively hunting for the Higg’s Boson and
helping to eliminate some of the mass energy ranges that it could reside in.
Flurries of particles were identified and greater understanding into the
standard model governing particle physics came with the experimental
observations for the predictions that it made. With the LHC going strong
hopefully the work conducted at Tevatron shalln’t be forgotten and who knows
what the last scraps of data will hold.

Biolaser.

A report in June in the journal Nature photonics reported and experiment where
biological components were turned into lasers. Fluorescent proteins from
jellyfish were inserted into the genome of mammalian cells which were suspended
between two mirrors. The effect of the living cells suspended between saw an
amplification of an inserted photon inducing a lasing process. The significance
of this was that the cell and the proteins survived which is often not observed
when fluorescent proteins undergo continuous light excitation. With the
development of this technique the biological lasers may be seen in future in
nanotechnology and other more familiar regions as CD/DVD players. In regards to
these biological systems it is very much watch this space.

James Webb Space telescope vs politics.

More delays and issues arose in regards to the Hubble telescopes successor this
year, the James Webb Telescope. The telescope which when complete will reside in
a region 1.5 million kilometres away from Earth far away from any communication
disturbances, it will also comprise of a set of mirrors exceeding the size of
Hubble allowing for far higher resolution. The telescope however has come under
fire due to spiralling costs of $8.7 billion and rising. With the rising costs
the House appropriations committee in the US have declared that given the chance
they would prefer to cancel the project rather than provide more funding to
sustain it until launch in 2018. Some members of the senate have come out in
support of the telescope and NASA have also hit back saying it could be made
cheaper with more money spent now to have it readied prior to the current
estimated completion date. 2012 will tell whether the project survives and if
the completion date changes at all.

And to commemorate the Shuttle here’s an awesome video by Nature with Sheffield’s finest 65daysofstatic providing the music.

http://www.youtube.com/watch?v=II7QBLt36xo

Beta radiation is on of the 3 types of radiactive decay that occur in nature, the others being alpha decay and gamma radiation. Henri Becquerel was awarded the 1906 nobel prize in physics with the Curies for his contribution to the discovery of radioactivity, Becquerel’s discovery being that of beta radiation. This discovery came as an accident to Becquerel whilst experimenting with fluorescence from Uranium. Uranium salts exposed photographic plates wrapped in black paper with an unknown radiation that couldn’t be turned off like X-rays. Ernest Rutherford later continued these experiments to conclude that 2 types of radiation were present, alpha particles (alpha radiation) that didn’t show up as they were absorbed by the paper and beta particles (radiation) that were much more penetrating than alpha particles and able to expose the plate.

We now know the workings of beta radiation and the risks that it can pose to health (unlike at the time of it’s discovery). So, beta decay occurs in one of two ways either as a B+ decay or B- decay of which are determined by the particle that is ejected from the atomic nucleus during the decay process. An unstable nucleus with an excess of neutrons may undergo a B- decay where a neutron is converted into a proton, an electron and an electron type anti neutrino. The proton in this case remains in the nucleus, the electron and anti neutrino are emitted from the nucleus at high speed. A similar situation occurs with B+ decay, in B+ a proton undergoes a conversion to a neutron leading to the emission of a positron (anti particle of the electron) and an electron neutrino.

Beta decay is mediated by the weak nuclear force and as a result weak interaction by causing changes at the quark level (although I won’t go into this). The neutrino is introduced is present in this decay to account for what was initially deemed ‘missing’ energy. In decay a small amount of energy wasn’t present in the decay products this was eventually accounted for by the discovery of the neutrino.

Beta particles although ionising and harmful to health, have their uses to us. They are used to treat a number of eye and bone cancers as well as being used as radioactive tracers. They can also be used in manufacture processes to control the thickness of items coming through a system of rollers, the absorption of particles being correlated to the thickness.

The variability in human performance also generates the further problem of generalisation. How can you be sure that the participants you have used in your study provide data that can be generalised to humans in general, given that individuals vary widely on how they perform the task? Larger samples (more data collection!) can make a sample more representative, but as undergraduates are usually the easiest source of data, inevitably most studies involving humans utilise samples that are non-representative of the general population to a greater or lesser extent. You could write an entire book on the issues around sampling and generalisation (indeed many have (1)) suffice to say that when you read any behavioural science research, especially that which is weighted towards the ‘social science’ end of the spectrum, it is worth considering the sort of people who may have participated in the research, and how that may effect the results that were found.

There are other, more basic problems with using humans as a data source.  Participants may fail to show up for the study, they may fail to understand what is required of them in ways that you couldn’t predict, they may even not take the experiment seriously, making little effort or deliberately producing nonsensical data. In physical science I suspect the main problem that can occur with an experiment is equipment failure. This is also a danger with behavioural experiments, but ‘participant failure’ is often a more pressing concern.

A final issue with using humans as a data source is that any study involving humans requires ethical approval, meaning that the research design is scrutinized by a committee prior to data collection for anything that might be deemed unacceptable. Ethical procedures are in place for a good reason, as in the past certain scientists were subjecting volunteers to all sorts of unpleasant and/or morally dubious procedures in the name of science (2). However perhaps inevitably ethical checks tend towards the cautious in terms of their application. While for many behavioural and social science research, ethical approval is merely a formality, it can restrict scientific enquiry for those of us that are interested in the facets of human behaviour that can only be evoked through manipulations of the participant’s emotional state or physical comfort.

So, given that I have just spent 700 words complaining about the problems of using humans as data sources,  why have I chosen a career path which relies so heavily on collecting data from humans? Well there are some advantages of performing research on humans. Most importantly humans are (to me at least) the most interesting subject in science. You can keep your chromatography, your mutagenesis and your particle accelerators, nothing they produce will ever be as interesting to me as investigations into human mind and behaviour. The variability in human performance which causes us so many problems is actually the main reason the subject of psychology is so interesting. A second advantage to behavioural research is that it allows you to meet a lot of different people who volunteer for your study for a variety of different reasons. The fact that certain people are prepared to give up their time and submit themselves to the often unpleasant or tedious tasks that make up your research project has helped reaffirm my faith in human nature after years of working in soul-destroying office jobs. Apart form anything else, the actual data collection part of a behavioural study certainly helps to break up a research process which would otherwise mainly consist of reading journal articles and staring at a matrix of numbers on a computer screen.

I’ll be coming to the end of the data collection process soon. I will then have weeks of grappling with the resultant data to look forward to!! As a final plea, if there are any men out there who fancy participating in my research then get in contact, as I still need a few human ‘data sources’ to complete my study!

(1) Rao (2000) Sampling methodologies with applications. Chapman & Hall
(2) See the early chapters of Naomi Klein’s book “The Shock Doctrine” (Penguin, 2008) for a description of some particularly unethical experiments performed in the US.

The best description of my area of research is ‘cognitive neuroscience’, but what does this mean? Cognitive Neuroscience relates to the study of the neural basis of behaviour. Roughly, it bridges the gap between biological sciences, and behavioural sciences such as psychology and psychiatry. It attempts to determine how the brain achieves the legion of processes that it performs – crudely ‘what part of the brain does what’! Cognitive neuroscience has only been seen as a separate area of study relatively recently, partly because the advanced brain imaging techniques which the discipline now heavily relies on have only been developed within the last 30 years (according to Wikipedia the term ‘cognitive neuroscience’ itself was coined in the back of a taxi in 1979!!). However scientists from various disciplines have been trying to understand how the brain functions, using whatever methods were available, since at least the 19th century.

Cognitive Neuroscience relies heavily on work done within behavioural sciences, which have served to define how human behaviour and cognition can be classified into concepts that can be studied. Unsurprisingly therefore, cognitive neuroscience research normally involves the application of a behavioural task which has already been utilised without the use of brain imaging techniques. One question this raises is what does knowing how the brain achieves it function tell us that purely behavioural science does not?  Psychologists have been ably investigating the details of mental processes for well over a century without knowing (or even caring) what part(s) of the brain are involved. The knowledge that spatial processing is largely dependent on the Hippocampus is not necessary for studying the intricacies and individual differences in spatial processing. So what does an understanding of the neural basis of mental processes achieve?

Firstly understanding the neural basis of a mental process can help distinguish between different theories relating to how that process is performed. Behavioural data is often not sufficient to distinguish between competing theories (e.g. whether a particular process is performed in totality, or whether it is split into components processes that are dealt with separately, and whether such component processes are performed in parallel or in series). Neuroimaging data can be used to provide strong evidence in relation to these questions (1).  Secondly cognitive neuroscience can provide insight into areas of cognition that were difficult or impossible to address without neuroimaging techniques. For example much work has been done on trying to understand what the brain does ‘at rest’ (i.e. when no task is being performed, effectively ‘mind wandering’) which can allow us to understand how the brain might work as an self-contained integrative mechanism. As, by definition, non-task related mental processes can’t be manipulated systematically, it is hard to investigate these processes from a purely behavioural standpoint. Similarly neuroimaging has enabled scientists to begin to uncover the neural basis of ‘consciousness’, raising interesting questions about how our experience of the world is constructed (3). These achievements of cognitive neuroscience help elucidate the nature of human thought and behaviour, shedding light on why we act the way that we do. 

On a larger scale, understanding how the brain is able to processes such a large variety of information, and produce such a wide variety of responses, can help guide the design of artificial intelligence systems intended to mimic human abilities, facilitating advances in medicine and engineering. Finally, and perhaps most importantly, knowing how the brain produces certain responses can lead to the development of interventions to alter the functioning of the appropriate brain areas when those responses become problematic (e.g. during mental health disorders). One of the major aims of cognitive neuroscience is to identify the neural deficiencies that mark various psychiatry and neurodegenerative disorders. From this information it becomes potentially possible to identify methods of combating such deficiencies. Indeed biological interventions are being developed that can target specific brain areas, potentially offering great hope for improving the therapeutic treatment of mental disorders.  

References

(1) Jonides et al (2006). What has Functional Neuroimaging told us about the Mind? So many examples, so little space. Cortex, 42, 414-417

(2) Van den Heuval & Pol (2010) Exploring the brain network: A review on resting-state fMRI functional connectivity. European Neuropsychopharmacology, 20(8), 519-534

(3) Dehaene & Changeux (2011) Experimental and Theoretical Approaches to Conscious Processing. Neuron, 70. 200-225

We are offering £250 to the best brand new event/workshop idea!  In return all we ask is that you submit a summary of your idea (no more than 500 words) to: dragonsden@sciencebrainwaves.com by Tuesday 1^st November.  We will then select the best 10 and ask you to pitch your event idea to a panel of expert judges on Tuesday 22^nd November, 8pm, Coffee Revolution.

We are open to any idea, be it a lecture, a debate, a new science experimentation workshop which could be hosted at schools and colleges, an adult event, an event for families, for children, for men/women, boys/girls – we really don’t mind! Our only request is that the event somehow can be linked to the British Science Association National Science and Engineering Week 2012 theme – ‘Our World in Motion’ – this is such a broad title, we really feel anything could be fitted into it somehow!!

In addition to the £250 prize money, we will support your event 100%, allowing you access to our large media and ‘useful’ contact network.  Offering any advice needed, whether that’s how to promote the event, finding additional funding, where to find the best venue, recruiting volunteers or even what colour scheme would work best!

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