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Saturday, 31 October 2015

Our face spiders - friends or foes?

You may be surprised (or perhaps horrified) to know that you have spiders on your face right now. In addition to the millions of bacteria, viruses and fungi that make up our skin microbiome (the community of microorganisms on our skin) we have microscopic eight-legged creatures that also make a home in our skin. In humans there are two species; Demodex folliculorum which reside in our hair follicles and Demodex brevis which are found in our sebaceous glands[1]. They are just two of the 46,000 different species of mites that form the Arachnid family along with spiders and ticks.

Thankfully, the arachnids on your face aren't as big as this Christmas Lights Jumping Spider! Jumping spiders sometimes follow convoluted routes when hunting, even losing sight of their prey. How and why they do this, especially given the size of their brains, is also an open question. Image credit: public domain, via USGS (Flickr)

While studies suggest that we aren’t born with these creatures on our skin, but acquire them over time as a result of skin to skin contact with our mothers, how the spiders get onto us remains a fundamental mystery. Their numbers increase as we get older, but we don’t know why this is[2,3]. To date scientists have been unable to culture Demodex long term outside the body, as they dry out very easily[4,5]. As a result they are difficult to research and little is known about their life cycle apart from the observations of Spickett in 1961. He suggested that the mites roam the surface of our skin at night in order to breed. Females lay eggs within our hair follicles where they hatch and develop into adults and the cycle starts again[6].

Thursday, 22 October 2015

The Energy of Atoms (other than Hydrogen)

Whilst the things we don’t know about quantum mechanics could fill a black hole, it’s still thought of as a glorious theory that swept in and revolutionised atomic theory. In a way it has, well, revolutionised one atom: hydrogen. Because that’s the only atom we know how to “solve”.

Hydrogen atom cartoon copyright TWDK / R. Fletcher-Wood
The hydrogen atom consists of just one proton in the nucleus and one surrounding electron: a simple system to model. Image credit: TWDK / Rowena Fletcher-Wood

Monday, 21 September 2015

Location, Location, Location

Nuclear power and nuclear waste are sensitive public issues. Whilst the Finns are already building a geological disposal facility in Onkalo, in the UK we still haven’t decided what to do with our waste. Before the site can be chosen and built, a formal, scientific safety case must be completed, evidencing the likelihood that the containment facility will remain intact on a timescale of at least thousands of years. Learning from the “Yucca Mountain controversy”, where the state of Nevada legally opposed the construction of an American disposal facility on the grounds that they didn’t want to be lumbered with the country’s nuclear waste without consent, the UK government are waiting for volunteer communities to emerge before they can even start studying local geology in detail. Huge climate and geological changes, including at least one ice age, are predicted, which would totally change the landscape, the exact impacts of which could vary widely depending on where nuclear waste goes.

Low-level waste storage pit at the Nevada National Security Site
Nuclear waste is divided into three categories: High, Intermediate and Low Level Waste. High Level Waste is what's left after spent fuel is recycled to extract as many reusable uranium and plutonium fuel isotopes as possible. This waste is usually vitrified: transformed into a glass by fusing with borosilicates at high temperature. Intermediate and Low Level Wastes are non-fuel items (such as containers) that have been or may be been contaminated during normal operation of the nuclear power plant, and comprise the bulk of the waste. Image credit: Nevada Test Site Guide (public domain)

Tuesday, 8 September 2015

Do cheaters prosper?

Attempting to selfishly gain an immediate advantage in a situation where others are co-operating is called social cheating. Many people are likely to bitterly recall an experience of this, queue jumping is a classic example, and a wide variety of other organisms undergo the same injustices. Cheaters in theory should have an evolutionary edge, but social co-operation remains at the base of almost all populations. This is a mystery that scientists have been intrigued by for years, as there is very little we really understand about these behaviours and how they co-exist.

Social systems can be ‘modelled’ in much simpler organisms than us; the social amoeba for example. Dictyostelium discoideum (Dicty), are generally alone throughout their lives, but for one 10 hour period. This time is where they become social in order to release spores that will grow into new amoebae. To do this they form ‘fruiting bodies’, where some Dicty give up their lives and harshly but more importantly; their bodies. These form a stalk, the top of which the spores can be released from. However some Dicty cheat - there are amoebae that climb straight to the top to release their spores and contribute less to the stalk. By doing this they release more spores than other, co-operating amoebae and so gain an evolutionary edge, passing on more of their genes. But this advantage cannot be significant, as otherwise they would overrun the co-operators and drive them to extinction.

Photograph of stalked slime mould fruiting bodies, by Lairich Rig (CC BY-SA 2.0)
The Dicty amoebae begin as single celled organisms, before congregating as a multicellular ‘slug’, which then gives rise to fruiting bodies with spores atop long stalks. In the species shown here, each of the sporangia was 2-3mm tall. Image credit: © Lairich Rig, via geograph (CC BY-SA 2.0)

Wednesday, 2 September 2015

The Inspirational Butterfly

An Insight into Developments in Solar Power

The UN is calling for drastic action to be taken to stop climate change in its tracks. With any luck an agreement will be reached this year on the actions that will need to be enforced by 2020 to tackle this worldwide issue[1]. As a result, countries are desperately attempting to reduce their carbon emissions, and focus on renewable energy sources is increasing. If the right developments are made to improve efficiency and distribution of renewable sources, we could be one step closer to establishing a sustainable worldwide energy supply and battling the ongoing threat of climate change.

The prospect of being able to harness energy from the Sun is one that has captured our interest given its relative reliability, and solar power is already a widespread phenomenon. However it does not yet compare to the cost of generating power from fossil fuels, and a result is often considered to be less economically viable.

Electrical apprentice Eric Penel works on the solar reference array, which has been installed on the roof of the Shaw Theatre at NAIT's Main Campus in Edmonton.
The UN conceded in the Kyoto Protocol that limiting global warming to just 2 degrees, relative to the pre-industrial temperature level, would be necessary to reduce harmful climate impacts. For this to be achievable a 75% decline in carbon emissions by 2050 would be necessary[2]. If innovations in solar power continue to progress at the current rate, it could become the world's largest energy source by 2050. Today, solar photovoltaics and concentrated solar power contribute 16% and 11% to global overall consumption, respectively[3]. Image credit: Northern Alberta Institute of Technology via Flickr (CC BY-ND 2.0)

Given the positive effect a switch to solar power could have on the climate, there is much ongoing research into whether the efficiency of solar power can be improved. Inspiration for this goal can sometimes be found in the most unlikely of places..

Wednesday, 19 August 2015

Food for Thought; the Future of Global Food?

A global food shortage may not appear to be a threat or worry for a lot of people; around half a billion have been diagnosed as obese, that’s 1 in 14 people worldwide[1]. However, with an estimated 1 in 9 people being malnourished, in many countries the threat is already a reality. Though numbers predicted vary, the global population was agreed to have breached 7 billion people by 2012[2]. Most estimates point to another 2 billion people on the planet by the middle of the century. To put that increase into perspective, when we reached the first billion by 1804 it took around 156 years to add 2 billion. At our current rate of growth, an addition of the same number again will happen more than five times faster.

Worldwide malnourishment data from United Nations World Food Programme 2012, and the global prevalence of obesity.
The prevalence of malnourishment and obesity across the globe, and the disparity between the two. South-east African countries appear most malnourished, whilst levels of obesity rose in almost every country last year. Image credits: Undernourishment by country (top) via wikimedia [CC BY-SA 3.0], obesity by country (bottom) from Institute for Health Metrics and Evaluation [CC BY-NC-ND 4.0]

Monday, 10 August 2015

New Horizons - The Mysteries of Pluto Unveiled

At 9pm on July 14th 2015, the NASA New Horizons mission team received a very important phone call..

New Horizons had completed the first ever flyby of Pluto. It took over nine years and three-billion miles to complete, but has finally given us our first detailed glimpse of the ex-planet at the end of the solar system. It looks like Pluto was definitely worth investigating.

Artist’s concept of New Horizons Approach to Pluto.
The New Horizons space probe has been designed to function with a minimal power input. It required less than 200 Watts of Power to reach Pluto - that’s less than a pair of light bulbs. Compared to a grand piano in size, New Horizons weighs just 478 kilograms[1]. Image credit: NASA/JHUAPL/SwRI

Monday, 3 August 2015

The Impossible Quasar at the Dawn of the Universe

The recent extraordinary discovery of the biggest and brightest quasar of the early universe has intrigued astronomers worldwide. The reason behind this? The quasar - SDSS J010013.02+280225.8 (affectionately nick-named J0100+2802), is far larger than current black hole theories predict it should be[1].

Artist’s impression of quasar J0100+2802.
Among the oldest and brightest entities in the universe, quasars eject jets of very bright light that can be seen from lightyears away. It was initially believed that different events were being seen when quasars were observed, but it was later established that our line of sight affected the appearance of the quasar, for example a blazar is a quasar with jets that are pointing towards Earth. Image credit: ESO/M. Kornmesser