The research was carried out on the velvet belly lanternshark, a small species found in the deep waters of the Atlantic Ocean and Mediterranean Sea.

The scientists believe that while the light-up spines can be seen by larger, potentially dangerous fish, they are harder for the shark’s prey to spot.

The study is published in the Nature journal Scientific Reports. 

Invisibility cloak

This species of lanternshark (Etmopterus spinax) lives in the mesopelagic zone of the ocean, which has a range between 200m and 1,000m in depth. 

It’s a way to say: ‘Don’t bite me, I’m dangerous, I have spines on my back. You could be hurt’”

Dr Julien Claes

Catholic University of Louvain

It is a diminutive shark; the largest can measure up to about 60cm in length, but most are about 45cm long.

Until recently, little had been known about this species, apart from the fact that like many deep sea creatures it has the ability to glow – a trait called bioluminescence.

Previous research found that the shark has light-producing cells called photophores in its belly, and it uses this light to camouflage itself.

“Imagine you are below the shark, the shark is swimming and you have the light from the Sun coming down,” explained Dr Julien Claes, a shark biologist from the Catholic University of Louvain in Belgium, and the lead author of the study.

“If you are just below the shark what you are going to see is a shadow. So imagine if the shark can actually produce a light, which is identical to the light produced by the Sun. Then the shadow of the shark is going to disappear.”

Any prey lurking below, typically a small fish called Mueller’s pearlside, will not see the shark coming.

However, this new study revealed that the shark is also luminescent on its top side.

Dr Claes said: “There are two spines, one in front of each dorsal fin, and just behind them you have two rows of photophores. They are like lightsabers – they illuminate the spine.

 “It was surprising – why would you try to be invisible from below but visible from the dorsal side?”

 Warning beacon

 Visual modelling experiments revealed that potential predators could see the light from several metres away. 

 The shark is attempting to show of its spines to any animals hoping to eat it

 The shark’s prey, however, could only see the glow from a distance of about 1.5m, giving them less chance of making an escape.

 The team concluded that the glowing spines were acting as a beacon, illuminating the shark’s threatening spines.

 Dr Claes: “It’s a way to say: ‘Don’t bite me, I’m dangerous, I have spines on my back. You could be hurt.’

 “When you live in this dark place, what you try to do is avoid is to be seen by other animals, because there are no places to hide. 

 “It can be very dangerous – you put yourself at risk when you produce light from your back, unless it acts as a warning system.”

 He said it was unusual to find an animal that was using light to both hide and advertise itself at the same time.

 “It’s surprising that these two apparently opposite behaviours can occur in a single organism at the same time. It is really paradoxical.”

Source:BBC

Couples struggling to have a baby should get fertility treatment more quickly and older women should gain access to IVF, new NHS guidelines say.

IVF should be offered after two years of failed attempts, not the current three, says the National Institute for Health and Clinical Excellence.

And the upper age limit should rise from 39 to 42 in England and Wales.

Some fertility experts fear the guidelines may not lead to changes because they are not binding.

In the past, NHS trusts have struggled to find the money to meet the IVF recommendations.

A report in 2011, showed one in four NHS trusts offered the full three cycles. Each round costs £3,000.

Around one in every seven heterosexual couples in the UK who are trying for a baby experience problems conceiving a child.

The Oxford Fertility Unit’s Tim Child said it would give hope to many couples.

In 2011, nearly 14,000 women became pregnant through IVF.

The new guidelines, which apply to England and Wales only, state that women aged between 40 and 42 should be offered one cycle of IVF as long as it is their first time and they have enough eggs.

The age limit for NHS-funded fertility treatment is 38 in Scotland and 39 in Northern Ireland, according to the Human Fertilisation and Embryology Authority.

Tim Child, who helped devise the guidelines and is the director of the Oxford Fertility Unit, said the decision was not taken lightly.

“When a woman reaches her mid-30s her fertility begins to decline, even more so from her late 30s.

“However, many women do conceive naturally in the 40 to 42 year age group. But for those who can’t, and who have been diagnosed with the medical condition of infertility, then improvement in IVF success rates over the last decade mean that we are now able to offer cost-effective treatment with a single IVF cycle.”

Medical advances mean this age group has similar success rates to that of younger women when the original guidelines were introduced in 2004.

The update still recommends women under 40 are offered three cycles of IVF.

Some fertility experts raised concerns that the expanded recommendations may not happen in reality.

Dr Sue Avery, a spokesperson for the British Fertility Society and from Birmingham Women’s Fertility Centre, told the BBC: “It’s good that there’s the possibility there, but the funding does not match.

“I can’t see any prospect of it happening immediately. Our biggest concern is hanging on to the funding we’ve got.”

The guidelines also introduced rules designed to significantly reduce the number of twins and triplets being born.

‘Increased risks’

Multiple births, a consequence of implanting more than one embryo to increase the odds of success, are one of the biggest risks associated with IVF for both mother and child.

Twins tend to be born smaller and earlier – triplets even more so.

Women under the age of 37 should have only one embryo transferred in their first cycle.

Caroline Wood: “We were fortunate, we could afford the treatment”

Subsequent cycles, and cycles in older women, can consider implanting two embryos.

Most couples should no longer be offered intrauterine insemination on the NHS, as its results are no better than sex.

However, when there is not an option – such as same sex couples and patients with certain disabilities – it would still be an option.

Dr Tony Falconer, president of the Royal College of Obstetricians and Gynaecologists, said fertility problems could have a devastating effect on couples.

He welcomed the guidelines, but warned there were risks attached.

“The recommendation that IVF treatment be made available up to the age of 42 provides more choice for women, but they should still be aware of the increased risks associated with pregnancy at advanced maternal age,” he said.

Source:BBC

There has been suggestions the number of new drugs being brought to market is falling

Fears the number of new medicines available to patients in the UK is declining have been rejected. 

Researchers found the number of drugs introduced during the last 30 years had in fact increased slightly, the BMJ Open journal reported.

This comes despite persistent suggestions they have dwindled, the Birmingham University team said.

Researchers came to the conclusion after analysing data in the British National Formulary guide on drugs.

They looked at how many new medicines were added between 1971 and 2011.

The average number of drugs introduced per year was just under 23, varying from nine in the lowest year to 34 in the highest.

The researchers said there were steep peaks and troughs over this period, including a dip between 1998 and 2006. Since then the numbers have risen again.

It has meant in recent years there have been 0.16 more drugs being produced every year than there were in the 1970s.

‘Pessimism’

Previous research projects which have found declines in the number of new medicines focused on smaller periods of time, the study said.

But it still said the rising costs of drug development and the increase in time in takes from to bring a new drug to the market remains an ongoing problem for the pharmaceutical industry.

Report author Dr Derek Ward said: “We started this research because there was a great deal of pessimism within the industry and among pharmaceutical companies about the number of new drugs that were getting to the market.

“We found that looking at the data over the longer term there was a slight increase. This is obviously a good thing for patients, if more new medicines are becoming available.”

Dr Phil L’Huillier, from Cancer Research Technology, part of Cancer Research UK, said: “This is encouraging news. Although the cost of developing drugs is accelerating, meaning that the number of drugs per pound invested in research and development is decreasing, there is a wealth of innovation in UK drug discovery.

“The landscape is shifting with pharmaceutical companies increasingly collaborating with academia for discovery and development of drugs. This more collaborative model is being applied to the high-risk innovative early stages of drug discovery, with companies taking on the highly expensive later stage development.

“Cancer Research Technology has recently launched a £50M fund to stimulate investment in drugs discovery in the UK to support innovative early-stage drugs discovery and development and bridge the gap between work carried out in the lab right up to early phase clinical trials to prove drugs can benefit for patients.”

Association of the British Pharmaceutical Industry chief executive Stephen Whitehead said: “It is a common myth that our industry has struggled to develop new medicines, when in reality the research pipelines of companies are healthy.”

Source:BBC

Deet works the first time, but for some hours afterwards it loses its power

The widely used insect repellent Deet appears to be losing its effectiveness against mosquitoes, scientists say.

Researchers from the London School of Hygiene and Tropical Medicine say mosquitoes are first deterred by the substance, but then later ignore it.

They say more research is needed to find alternatives to Deet, which was first developed by the US military.

The research was carried out on Aedes aegypti, a species of mosquito that spreads dengue and yellow fever.

The findings are published in the journal Plos One.

Dr James Logan from the London School of Hygiene and Tropical Medicine, said: “The more we can understand about how repellents work and how mosquitoes detect them, the better we can work out ways to get around the problem when they do become resistant to repellents.”

Deet – or N,N-diethyl-meta-toluamide – is one of the most widely used active ingredients in insect repellents. It was developed by the US military, following its experience of jungle warfare during World War II.

Mosquitoes are very good at evolving very very quickly”

Dr James Logan

London School of Hygiene and Tropical Medicine

For many years, it was not clear exactly how the chemical worked, but recent research suggests that insects simply do not like the smell.

However, there are concerns that some mosquitoes are growing resistant to it.

To find out more, researchers from the London School of Hygiene and Tropical Medicine took some A. aegypti mosquitoes in the laboratory, and tempted them with a human arm covered in Deet.

As expected, the repellent put the insects off their potential meal.

However, a few hours later when the same mosquitoes were offered a chance to dine again, the researchers found that the Deet was less effective.

To investigate why this might be happening, the researchers attached electrodes to the insects’ antenna.

Dr Logan explained: “We were able to record the response of the receptors on the antenna to Deet, and what we found was the mosquitoes were no longer as sensitive to the chemical, so they weren’t picking it up as well.

“There is something about being exposed to the chemical that first time that changes their olfactory system – changes their sense of smell – and their ability to smell Deet, which makes it less effective.”

Arms race

Earlier research by the same team found that genetic changes to the same species of mosquito can make them immune to Deet, although it was not clear if there were any mosquitoes like this in the wild.

Dr Logan said it was vital to understand both these permanent genetic and temporary olfactory changes that were taking place.

He said: “Mosquitoes are very good at evolving very very quickly.”

He stressed that the findings should not stop people from using Deet in high risk areas, but that they would help scientists who are trying to find new versions that could be effective.

To follow up on the study, the researchers now plan to find out how long the effect lasts after the initial exposure to the chemical.

The team would also like to study the effect in other mosquitoes, including the species that transmit malaria.

Source:BBC