cellsandsensibility

Why didn’t you get bitten?

Those who do not complain are never pitied. – Jane Austen
 

I have recently come back from a holiday in the Mediterranean, a well-known mosquito hot spot. On the last night of my holiday, having diligently applied DEET throughout the week I completely forgot to spray it on. As a (very painful) result I ended up with 25 bites, and yet the person who slept no more than a foot away from me escaped scot-free.  This got me thinking, is there something specific to each person that makes them more or less tasty to these blood sucking parasites?

Now I’m home and I’ve done a little research into the subject it seems there is no universal answer to this question. Just many scientists each with their own theory valiantly testing and hypothesising in order to one day develop a fool proof repellent.

It has been well known for years that mosquitos are attracted by the CO2 we all breathe out and apparently they can “smell” us from up to 50km away. However, everyone breathes so this can’t be the reason why some are bitten more than others, except when it comes to pregnant women who exhale 21% more CO2 than their non-pregnant friends. So what else attracts mosquitos? The second most common answer to this is body heat, and there might be something to this hypothesis also proved by pregnant ladies. When carrying a baby the woman’s stomach will be much warmer than the rest of the body due to the amniotic fluid inside, this increase in temperature has been shown to attract mosquitoes to the woman and increase the number of bites.

One hypothesis that has since been debunked was that it is your sweat that attracts them, this theory might have been born out of the heat theory – warmer people attract mosquitoes, warm people sweat more, ergo sweat attracts mosquitoes. However, we now know this not to be true but there is a theory that some emissions from the skin do make a person more or less attractive.

The latest research has hypothesised that some people give off a “masking smell” that repels the mosquitoes by hiding the actual smell of their body. However the basis of this unattractive scent is still being researched. Some scientists believe it to be potassium in the blood which creates the natural repellent and so advocate eating lots of bananas, whereas others think it is the skin’s pH making bacteria on the skin emit specific chemicals. Whatever the cause of this masking there is a more pressing reason to finish this research than to reduce the cases of mild discomfort and ugly ankles in people like me. Across the world between 350-500 million people are infected and 1 million are killed each year and so by figuring out what keeps some people safe scientists hope to develop a repellent as new method of preventing malaria.

Whether the weather will be wonderful

“What dreadful hot weather we have! It keeps me in a state of constant inelegance” – Jane Austen

http://www.isciencemag.co.uk/features/dealing-with-britains-soggy-summers/

This is a piece that was originally published on the IScience website (link above) however, i’m also going to post it up on here in the interest of keeping all my writing work in one place (who said laziness??)

Deadling with Soggy Summers

Despite it being July, and officially British summer time, it still feels like October. This is the wettest summer in living memory and it has started to feel as if the rain will never stop. However, whilst most of us are bemoaning the loss of our suntans and the barbeque season, scientists at Lancaster University are looking ahead to next year and what might happen to the UK’s water reservoirs if similar conditions should repeat themselves.

This year the UK had the driest March in 57 years which led the South of England to enter a state of drought emergency. For Britain this emergency involves hosepipe bans and the phrase “stand-pipes” being bandied around with gusto. But then the UK suffered the wettest April since records began and what felt like 3 more months of continuous rain. So the ban was lifted in a majority of counties and the country heaved a sigh of relief. But only a few are asking what we might do in future if this happens again.

Dr Alison Browne from the Lancaster Environment Centre at Lancaster University, released research last month which she believes shows this cycle of drought and deluge will become more common in the coming years. Her research also outlines recommendations for the UK to upgrade its drought emergency system to something which more closely follows that of Australia. Browne claims that the UK’s method of dealing with drought is too off and on. “Either there is drought and a hosepipe ban is put in place, or there is no drought and everything is business as usual,” she says. “The impression that there is no lead-up time – no period of increasing dryness – is very misleading.”

Australia has a well-developed response to drought because water shortage has been a problem they have been coping with for many years. Their system has several grades of drought, each of which dictates different levels of water restriction and storage. Due to this there is never the sudden shock felt here when hosepipe bans are introduced. Browne also suggests that hosepipe bans are not the correct way to deal with a water shortage because it puts the responsibility onto house owners whereas much of this obligation should come from industry and large businesses. Browne specifically mentions car washes as high water-use businesses that should shoulder more restrictions.

Since the ban however, there has been an increase of a different kind of industry. The water-less car wash is a more environmentally responsible and cautious business which uses a technology that wraps and wipes the dirt rather than washing it off. Babatunde Sobola of Green Heart Wash says that companies like his are becoming more popular as people are becoming more environmentally aware. “Most people don’t know how much water they are using but since the ban people are starting to think about it more,” he says. Sobola wholeheartedly supported Browne’s recommendations for business and industry and added “Many people also don’t realise that it’s not just the environmental cost of wasting the water down the drain but also generating the energy needed to capture, clean and treat it before and after use.”

Whilst Australia’s drought warning system is very advanced, the recommendations made by Browne for it to be used in the UK mean that it would have to work in collaboration with the environmental agency, DEFRA and the water companies. This could be easier in theory than in practice. When asked if they would take on board the example set by Australia, Thames Water made it clear that they had the situation under control and needed no outside help at this time.

A spokesperson for Thames Water said: “Since the last drought in 2006, we have been investing to make our supplies more resilient. We have reduced leakage from our 20,000 mile network of pipes by a third to its lowest ever level. We have increased, by 20%, the maximum daily output of our underground storage system in northeast London, so it can now provide water for 1.2m people when required.”

However, as with many scientific issues in the public eye the problem here is not just implementing a system that could work but also keeping the public informed and being open about the challenges faced by our country in the coming years.

Whether the councils and water companies decide to follow the route outlined by Browne and restrict water use in advance of drought, or whether they decide to tackle the problem in a different way, one thing is clear. The UK needs a proper system built into the infrastructure to anticipate water shortage. If this fails to happen there will be problems the next time we suffer early summers, overcast days and soggy barbeques.

From the U.S. National Oceanic and Atmospheric Administration

 

What do you fancy doing on Friday night? How about a dissection?

cellsandsensibility:

“A mind lively and at ease, can do with seeing nothing, and can see nothing that does not answer.” – Jane Austen

 

With this post i’m going to be a little cheeky (and perhaps a little lazy) and re-post something I wrote for my university science blog. I’m sorry to be so blatant about this but please enjoy and also take a look around the Refractive Index website because there are some brilliant stories and fantastic writers on there.

Originally posted on Refractive Index:

 The style of a Friday night discourse at the Royal Institution was turned on its head during a recent lecture about Alzheimer’s.

Recently it has been hard to miss the news about the growing world population and the doom laden estimations that say it will rise to 9 billion by 2050. But a lesser thought of fact is the proportion of that population that will be elderly. Medicine is helping cure diseases and the outcome is a population that is living longer but suffering from more debilitating, age-related diseases. One such disease is Alzheimer’s, the subject of a lecture I attended at the Royal Institution back in March. Dr Simon Lovestone of King’s Health Partners was booked to talk about current treatments and tests on the horizon. However, I can’t say that my reason for attending was a purely altruistic worry about the future state of our health system…

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An abundance of technology for the future of solar energy

I am not one of those who neglect the reigning power to bow to the rising sun - Jane Austen

When Professor Grätzel invented the solar cell nearly 20 years ago, he probably thought this was the beginning of the end for the world’s energy problems. He may not have foreseen the difficulties with his creation and the following clamour in the solar energy industry to better his design.

This week, Northwestern University and University of Florida’s research schools have both released prototypes for new solar cells. Each of these is improvements based on the original design by Professor Grätzel in 1991. Grätzel-cells have been used for a decade to produce commercially available solar power, however there is a design fault with the solar-sensitive dye inside the cells causing it to leak and lose function after 18 months.

Both schools are aiming to generate solar electricity yet they have very different methods for the same outcome. The researchers at Northwestern University have combined nanotechnology and chemistry to create a solid state alternative to the leaky dye used in previous cells; whereas the University of Florida has chemically treated graphene to achieve increased electricity conversion rates within the cell. These varied methods exemplify the wide-ranging nature of solar energy technology.  

The vast availability of solar energy has led to a global endeavour to capture and convert it in many different ways. Just a single internet search will show results from new studies each week from several continents. This might lead one to think that all this new work will clog up an already saturated market. Yet Xiaochang Miao, a graduate student at the University of Florida, points out that as solar cells can be made from many assorted materials the market is larger than one might realise. In spite of this market size there is still a solar-cell shaped gap for a durable, commercially viable household solar-energy converter.

Despite the obvious leaky disadvantages of the Grätzel-cell, not all researchers are aiming to fill this gap in the market. Some are simply testing electrical conversion rates of materials to find the future of solar energy but at the same time not ruling out the possibility that solar energy might not be the future for America. As Xiaochang Miao put it,  “The future cannot be foreseen but we will recognize it when it is here. Solar will play a role for sure; it is environmentally friendly and we all know that the sun will continue to shine for millions and millions of years.”

How lonely is too lonely?

It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife’ Jane Austen

Thomas Wolfe once said “Loneliness is and always has been the central and inevitable experience of every man.” However, recent research has shown that there are different levels and types of loneliness and these affect humans in many varied ways.

A few of us will have felt as if we’ve spent too much time on our own, perhaps while revising, and joked that it was bad for our health but there are some people out there for which this is more than a joke. Research from Cornell University has discovered a link between the social pain of loneliness and changes in the body which mimic aging. Chronic loneliness can cause physical and psychological changes which can result in an increased chance of morbidity. Physical changes can include raised blood pressure which can in turn cause cardiovascular complications, vision changes, kidney faults and memory impairment.

The study at Cornell was reported in a recent publication of “Psychology and Aging” journal and measured the heart rates and blood pressures of lonely people of different ages, specifically 91 young people and 91 older. A preliminary test before the main research established the individual differences in perceived isolation and blood pressure measurements were taken before, during and after the cardiovascular tasks.

 The older non-lonely participants had a longer recovery time and greater cardiovascular stress reactivity typical of people over the age of 65, however the striking thing was that the lonely younger people had a similar response. Loneliness increased each of these measurements but had the greatest negative effect in older adults, putting them at greater risk. These lonely older adults has such a delayed recovery time that by the end of a 2 hours recovery period their heartrate had still not returned to baseline levels.

 Loneliness is difficult to detect because it can’t be indicated by the side of your social network, but instead by the meaningfulness of your social interactions. Research has shown that humans need satisfying associations and a close knit group to feel fulfilled because huamsn fundamentally need to feel connected to others.

This isn’t the first study of its kind, there has been previous research into the effects of loneliness on the body and heart rate but this is the first to add age as a significant factor.  Lead author of the study, Anthony Ong has shown the significant link here between loneliness and aging and has concluded that the feeling of loneliness is an adaptive one, signalling us to repair social connections.

Women in Chemistry

“Nobody minds having what is too good for them” – Jane Austen

This is just a little something i wrote earlier in the year about women in science but I thought i’d just post it up on here too.

Can you name three famous female scientists? For the majority of people even naming one is a struggle. Some remember Marie Curie, the Nobel prize winner who discovered radioactivity, then  things become much more difficult. Our lack of knowledge about women in science is not just due to ignorance, but – perhaps worse – that very few women make it as leading scientists  Since Marie Curie won her Nobel Prize in chemistry 100 years ago there have only been two other female Nobel chemistry winners.

The centenary of Marie Curie’s success was celebrated by the United Nations with its International Year of Chemistry last year. The aim was to spread passion for chemistry in young women and an interest in chemistry throughout the world. The year of chemistry officially began with a series of lectures and films at UNESCO’s headquarters in Paris in February. Irina Bokova, director general of UNESCO has underlined the importance of women in chemistry saying; “The world needs more women laureates.”

Helene Langevin-Joliot, a physics professor and the grand-daughter of Marie Curie and director of research at National Centre for Scientific Research (CNRS), says that “women were ignored in science until Marie Curie.” However, this ignorance seems to be far from gone and is a problem being addressed by activities in UNESCO’s year of chemistry.

A lack of women in chemistry not only raises the issue of equality and parity but also of the loss to the world of intellectual capital. By attracting more women in chemistry, we will be better placed to tackle the vast issues the world is facing – such as malnutrition, potable water shortages, energy shortages and climate change.

Efforts to combat ignorance about chemistry and the solutions it can provide began with a short film to inspire school children, especially girls, to study chemistry commissioned by the UN. Additionally, groups of female scientists from 44 countries met to celebrate the role of women. The event was named ‘women sharing a chemical moment in time.’ UNESCO has laid down a challenge; “to maintain the momentum through the IYC.” 

The year of chemistry had a promising start and there is real hope that the next generation of chemists will feature more women. With world population set to hit 9 billion by 2050 and the resource issues this will bring, the world will need every male – and female – chemist it can get its hands on.

A little bit of spice that’s good for your health

“Perhaps it is our imperfections that make us so perfect for one another” Jane Austen, Emma

Scientists early this week have discovered a new type of surgery to help aid weight loss but it’s slightly different to the usual invasive surgeries we’ve all read about. This is because it uses capsaicin the chemical which makes chillies spicy. If you enjoy spicy food you’ll understand the pleasure taken from the burning sensation created by this chemical however few people know that this is not its primary function. Capsaicin is an irritant for mammals and it, and other secondary compounds called capsaicinoids, are used by the plant as deterrents against herbivores and fungi. I always thought this was rather sad, that the chemical produced to keep us away is the one reason we go back and pick from the plant again and again.

In 2008 the national health and nutrition examination survey calculated at 34% of the adults in the UK are now obese – that is they have a BMI over 30 and this number was only set to increase. This means that the strain on our health service is also going to increase as many people struggle to lose the weight using old-fashioned methods and look towards surgery as an alternative option. Obesity as simple weight gain is not the only problem here, the associated diseases that can develop as a side effect are just as costly and painful to the person and the NHS, for example type 2 diabetes, cardiovascular disease and cancer. The current surgical options available are very invasive which is why scientists are constantly trying to find new methods to help people lose weight, especially the visceral abdominal weight (beer belly to you and me) which is associated with heart disease and diabetes.

But what does all this have to do with chillies? Well scientists at the Brigham and Womens Hospital have been using this chemical on the vagus nerve in the gut. This is the nerve which connects the gut and the brain and has been cut in past surgeries to treat ulcers but not in weight loss because of the side effect which include improper drainage of the intestine. However with this new surgery capsaicin is used to only sever the part of the nerve which sends inpulses from the gut to the brain and not the other way round. This means that the brain can still order the emptying of the gut and control its functions but the impulses that control type 2 diabetes don’t transmit. This type of surgery is called vagal de-afferentiation and works because the capsaicin overwhelmes the nerves to a point where they are depleted of neurotransmitters leading to a blockage of neurogenic information.

This test was done on rats where one group had the surgery and one didn’t but they were all fed a typical western diet for 11 months. The total body weight and percentage of visceral abdominal fat was measured and although the reduction of total body weight was found to be un-significant the belly fat reduction was “remarkable” according to Dr Ali Tavakkoli from the study. This result shows the surgery can influence the overall mortality risk and the future of this research is definitely looking positive with the research unit already talking about human trials.

This is not the first time the common chilly has come to the rescue with capsaicin being used in potential cancer treatments. Capsaicin can be used to bring on early cell apoptosis, which is cell death and so this has been trialled in lung tumours in Nottingham, prostate cancer in America and studies in Japan have shown Capsaicin inhibits the growth of leukemic cells.

Make Your Own Meat

One cannot fix one’s eyes on the commonest natural production without finding food for a rambling fancy – Jane Austen, Mansfield Park

In recent months the words “Man-made meat” have been appearing more frequently in the world’s media. This phrase looks scary on the page and has created more confusion with the public as it has been mistaken with imitation meat (vegetable protein replicas) and compared to Frankenstein food. Scientists are planning the release of information very carefully to avoid another full-scale public backlash as seen in the 90’s with GM crops. So in the interest of public understanding I’m going to explain exactly what is meant by man-made meat, sometimes described as In Vitro meat, and how far we – the public – are from ever encountering it on the supermarket shelves.

Man-made meat is made of real animal protein and not vegetable imitations like Quorn. (other vegetable based meat reproductions are available)  However, the difference with this animal protein is that it will never have been on a living animal; it is completely created within the lab. Initially created for use in long space voyages this lab project quickly grew in popularity to the extent where now there are 30 ongoing worldwide projects trying to create the first edible man made meat.

So how is it done? Firstly stem cells are extracted from an animal. This is the only part of the process that has anything to do with animals and they are not harmed in the process. Once the stem cells have been taken (usually from a muscle) they are converted into muscle cells; this is possible because stem cells are like the universal pre-cell and can transform into any cell in the body given the right hormonal signals. The cells are changed into muscle cells because this is where the majority of widely eaten meat from an animal comes from. Once converted into a muscle cell it will then divide and can be cultured onto a scaffold.

From here there can be two approaches to creating the meat, firstly the cell can be left to divide without a scaffold creating loose unstructured cells and meat. This was the method during early approaches to creating meat, however after years of further research and development the cells can now be grown onto a scaffold where they can be exercised and electrically stimulated just like real muscles inside an animal. Texture is just as important as taste in a food so the muscle must be stretched and exercised to develop the same tenderness one would experience in animal based meat.

Another factor which is important in food production is the taste of the meat, yet because this is still all highly experimental nothing has been tasted. However, other contents of the meat contribute to its taste for example fat and blood so the next stage of research is working on making the meat as authentic as possible for taste value. This also raises another important point, if the levels of fat in the meat can be controlled then healthier meat can be produced. Quorn is advertised as being so healthy because it contains much less saturated fat than normal meat, but if the fat levels can be controlled then this is just another reason why man made meat could be so popular.

There are more central motivations for the creation of man made meat besides just the health and animal protection implications. Meat production uses one third of global land area and contributes to a fifth of all greenhouse gases but by using lab grown meat instead we could decrease global emissions by 80-96% according to analysts fromOxfordUniversity. With an increasing population estimated by The UN to be at 9 billion by 2060 new food sources are constantly being researched and man made meat could be one solution among many.

But, how close are we to these world-saving statistics? Some meats have been produced – goldfish and lamb – and PETA increased research speeds by setting a challenge in 2008. They said they would give $1 million to the first company to create a whole chicken and sell it in 10 states by June 2012. Other companies around the world are saying they’ll be able to create sausage by March 2012 and hamburger by September 2012. These last two meats are unstructured and so can be manufactured using the first technique I outlined earlier.

Another barrier to the global consumption of this meat is the price. At the moment productions costs are astronomically high – US$1 million per 250grams of beef – but estimates say that with investment in current technology the cost could be brought down to twice the current price of normal meat. However, this is still a problem if this meat is being targeted as a solution for growing third world hunger, and even a wealthy western family would ask why they should buy a more expensive version of the same thing? However, with the length of time it will take for this product to go from lab surface to kitchen-counter prices and costs could change dramatically. But for the meantime it looks like we’ll be waiting a bit longer for man-made beef steaks and fillets of seabass.

A Link Between Sleeping and Eating?

There is nothing like staying at home for real comfort. – Jane Austen

I know that the whole idea of this blog is to find scientific subjects and “translate” them for a non-scientific audience however i’ve just written this article for the university science magazine so i thought i’d include it in here anyway!

 

Melatonin link with diabetes risk confirmed

Researchers from Imperial College have identified 4 specific mutations in a melatonin receptor that have a link with an increased risk of developing type 2 diabetes. This discovery is the result of research continued from work done in 2008 by the same group of scientists.

Melatonin is a chemical that controls the body’s sleep cycles and temperature levels as well as many other homeostatic mechanisms. When the levels of melatonin are disrupted this can cause health problems because melatonin regulates the release of insulin into the blood.

Work in 2008 showed mutations in the melatonin gene, called MTRN 1B which codes for the melatonin receptor can increase the risk of type 2 diabetes. More recently Professor Philippe Frogel of Imperial College led new research starting with an analysis of the gene in 7600 people which found 40 variants and identified 4 specific mutation sites. At these mutation sites the melatonin receptor was completely unable to respond to melatonin. Also having a mutation at these sites increased the risk of developing type 2 diabetes by 6 times.

This research could be used in the future to accurately access a person’s risk of developing diabetes and lead to development of personalised treatments. Melatonin also regulates energy metabolism and body weight control within the body so this research could have future implications for work on obesity treatments. 

The Morning After The Night Before

“Which of all my important nothings shall I tell you first?” – Jane Austen

 

Supposedly what makes humans different from animals is our ability to learn from our mistakes and adjust our behaviour accordingly. For example we now know that dirty water in some countries could harbour cholera bacteria, so we clean and purify our water – we have learnt from previous epidemics. I chose cholera as an example because the symptoms (although much more extreme) are similar to those of a hangover – fatigue, vomiting, headaches etc. However, despite our ability to learn from the symptoms of one affliction, our intelligence becomes limited when faced with another – alcohol.

The after-effects of an enjoyable evening are by no means a new invention, these symptoms have been noted as far back as in the bible “Woe unto them that rise up early in the morning, that they may follow strong drink” (Isaiah 5:11) yet still we don’t learn. So instead of moderating our intake let’s keep enjoying ourselves and try to find out the reasons for hangovers, and in turn try to lessen the effects and find good cures.

There can be many biological reasons for those awful feelings the morning after and these can all be grouped under “chemical imbalances”. Alcohol affects the working of the brain, liver, kidney and stomach to name a few and by changing the way these things work it changes what they produce. The first of these and perhaps the most immediate to have an effect after the first drink is the brain’s production of vasopressin; under normal conditions this chemical is produced in the pituitary gland and controls the amount of water the body retains or expels.

Alcohol affects the pituitary gland and halts the production of vasopressin, stopping any water being re-absorbed into the body. This has the double effect of dehydrating you and making you need the loo all the time. The next morning your body tells you how thirsty it is by causing a dry mouth and headaches because the body’s organs try to sequester much needed water from the brain. This causes shrinkage which makes the brain pull on the membranes which connect it to the skull leading to pain. Excessive urination expels minerals like potassium and sodium from the body which explains the shakes and tiredness the next morning.

Another cause of the rotten feelings the morning after is a build-up of a mid-point chemical produced in the breakdown of alcohol. Alcohol breaks down in two steps, firstly to acetaldehyde and then in the second step to acetate. However, the enzyme glutathione which breaks down acetaldehyde is kept in short supply in the liver and runs out quickly which causes a chemical build up. This imbalance is what causes the main symptoms of headaches and vomiting and is the reason why in general woman can’t match men drink for drink. Women have a smaller store of glutamine and so the alcohol takes longer to break down which endorses the generalisation that women get worse hangovers then men.

Glutamine also has a second purpose in the body as a natural stimulant for the brain but its production is inhibited by alcohol. This means that when a person has stopped drinking for the evening and climbs into bed the production of the stimulant is resumed just about time when the brain wants to sleep. This explains why you always feel so tired with a hangover, because your body couldn’t reach the deepest level of sleep which restores and heals the mind. This chemical spike is called the “glutamine rebound” and is also responsible for the tremors, anxiety and increased blood pressure the morning after.

The final and most unappealing symptom of a hangover has to be vomiting which is of course a result of many factors, from how much you ate to simple quantity of liquid in your stomach. However a more chemical explanation is that alcohol stimulates the production of hydrochloric acid in the stomach which irritates the nerve endings embedded in the stomach wall. This sends a message to the brain stimulating the evacuation of the stomach.

After all this suffering the following morning I can hear you calling for a cure to your ailments. There are many remedies out there, some based in fact and others in superstition and I’ll be looking at some of these in my next blog and reasons why they do or don’t work.

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