US scientists identify forces driving geological activity on Saturn moon

Parliamentary Yearbook reports on research by American scientists at Cornell University which provides evidence of Saturn’s gravitational pull on one of its moons, called Enceladus.  Saturn’s tidal gravitational forces are responsible for variations in the intensity of plumes of icy water particles erupting from geysers on the surface of Enceladus.

Enceladus is one of the inner moons orbiting the planet Saturn, which has over 60 moons in total. It was first discovered in 1789 by the German-born British astronomer, William Herschel.  Apart from the presence of water ice on its surface, very little was known about Enceladus until recently.  During the 1980s, the Voyager spacecraft mission to the Saturnian system revealed most of what we know about the moon today.

Enceladus is 500km wide and reflects almost all of the sunlight that strikes its surface, caused by a very smooth surface of fresh water ice. Consequently, the surface temperature is a chilly -201 degrees Celsius (-330 degrees Fahrenheit).  It has at least five different types of terrain.  In addition to areas containing craters (up to 21 miles wide), it has smooth plains, linear crack and ridges, fissures and distinctive crustal formations. According to experts, these features indicate that the interior of the moon may be liquid today, despite the fact that it should have frozen a very long time ago.

Following the Voyager mission, scientists proposed that Enceladus may be geologically active and believed that water venting through the moon’s surface could be responsible for the icy material in one of Saturn’s rings.

In 2005, the Cassini-Hyugens Mission to Saturn produced images of plumes of icy material rising from the surface of Enceladus.  Later images subsequently identified jets of icy particles resembling geysers or volcanoes erupting from the southern polar region of the moon.  These were identified as jets of water particles, freezing on contact with the cold space temperatures.

Since 2005, scientists have sought to understand the effects of Saturn’s gravity on Enceladus.  They have predicted that Saturn’s gravitational forces cause Enceladus to stretch and compress, creating heat and pressure which forces liquid through cracks in the moon’s icy surface.

In this latest research, American scientists from Cornell University have analysed 252 images of Enceladus during its orbit around Saturn. The images, taken by NASA’s Cassini spacecraft, provide evidence that the intensity of the icy plumes varies systematically depending on the proximity of Enceladus from Saturn.

The data show that the icy plume is dimmest when Enceladus is closest to Saturn, becoming increasingly brighter as it orbits away from the planet. At its most distant point from Saturn, the plume is three to four times times brighter than at its dimmest.  

According to Dr Matthew Ledman, lead researcher: “What this tells us is that Saturn’s tides are having a significant effect on how much material can escape from beneath Enceladus.”

Close up, Saturn’s gravitational squeeze partly closes up the polar fissures, nicknamed ‘tiger stripes’.  This limits how much material they release. As the moon moves further away from Saturn, the fissures open wider, releasing more material which results in bigger and brighter plumes.

Dr Ledman said: “Previous models predicted that when Enceladus was near the point most distant from Saturn, the cracks would be pulled open or widened, and the most amount of liquid would escape.  This is the first observational data we have that show quite clearly that is the case.”

He explained that the extent to which Enceladus responds to Saturn’s tidal forces may provide an important insight into the rigidity of Enceladus’ interior. The findings may help scientists understand what is happening beneath the moon’s surface and help to identify the source of the ice streams and water vapour.

NASA planetary scientist, Terry Hurford, was the first to predict Saturn’s tidal forces on Enceladus. He said: “On the model I used to predict this variability in the stresses, I assume there’s a global ocean and not just a local sea.”

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Unusual patterns of jellyfish sightings reflect the state our seas

Parliamentary Yearbook reports on unusual patterns of UK jellyfish monitored by the Marine Conservation Society during 2013.  According to the charity, jellyfish populations are “important indicators of the state of our seas”.

Despite their name, jellyfish are not fish. They are invertebrates belonging to an animal group called the cnidarians.  This animal group has stinging cells which are used both to capture prey, and as a defence against predators.    Their stinging cells contain a capsule which consists of a rolled filament and a poison.  When contact is made with the surface of the jellyfish, these capsules open, ejecting the filaments into their prey, through which poison is injected.  They are perfectly camouflaged because their body is 95% water. 

The collective name for a group of jellyfish is “bloom”, “swarm”, or “smack”.  The preferred term for a large group of jellyfish that congregate in a small area associated with seasonal increase or when numbers exceed the norm is “bloom”.

Scientists do not know the ultimate causes of jellyfish blooms but believe that bloom formation is a complex process which may depend on a number of factors. This includes ocean currents, nutrients, sunshine, temperature, season, prey availability, reduced predation and oxygen concentrations. 

Over the last ten years, Britain’s Marine Conservation Society (MSC) have been responsible for monitoring sightings of marine life species - including jellyfish - in UK and Irish waters. Researchers from the MSC have reported unusual patterns of jellyfish sightings for 2013.  Compared with previous years, there were very few sightings reported until June, followed by unusually high numbers reported during the summer months.  The researchers believe this was due to an unusually cold spring, followed by an extreme summer heat wave.

According to Dr Peter Richardson, the MSC’s biodiversity programme manager, “the scarcity of jellyfish reports before June was unusual and could well be linked to the exceptionally cold spring”.

He went on to say: “As our waters warmed, sightings of jellyfish increased with moon jellyfish reported in large numbers around the UK, reports of compass and blue jellyfish in the South West, and blooms of lion’s mane jellies around North Wales and north-west England.”

Dr Richardson reports that there is evidence that numbers have been increasing around the world. At the same time, he noted the diversity of opinion as to the cause. While some scientists argue that numbers increase and decrease as part of a normal cycle every 20 years, others believe that the increases are linked to causal factors which disrupt the natural water ecosystem. 

One such factor is the pollution of our oceans from industrial and agricultural practices, resulting in a process known as ‘eutrophication’.  This occurs when water bodies receive excess chemical nutrients such as phosphorous and nitrogen which disrupt the natural ecosystem to stimulate excess plant growth.  It results in massive algal blooms, accompanied by low levels of oxygen.  Jellyfish are known to thrive in such waters.

Other causal factors described include over-harvesting of fish - which compete with jellyfish for the same kind of food - is believed to lead to jellyfish proliferation and climate change, which affects changes in water temperature.

Whatever the cause, Dr Richardson believes that we “should consider jellyfish populations as important indicators of the state of our seas” and that large increases “are telling us about the health of our seas and cannot be ignored”.

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Climate change is driving melting at world’s thickest ice sheet: alarming new evidence

Parliamentary Yearbook examines research by British scientists which suggests that glaciers along 5,400 km of the edge of the East Antarctic ice sheet are systematically changing in line with changes in temperature. 

There is significant concern about the impact that the earth’s increased temperature - over the last 100 years – is exerting on our planet.  As rising temperatures affects glaciers and icebergs, the ice caps at the Earth’s two Polar Regions - the North Pole and South Pole - are exposed to an increasing risk of melting which will cause the oceans to rise with devastating consequences.

The polar region at the northernmost part of the Earth is of course known at the ‘Arctic’.  This includes the Arctic Ocean and parts of Canada, Russia, the United States (Alaska), Denmark (Greenland), Norway, Sweden, Finland and Iceland.  The Arctic Ocean in this area is covered by floating pack ice (sea ice), surrounded by treeless frozen soil. Known as permafrost, this is soil which has been at or below the freezing point of water for two or more years.  The average temperature for the warmest Arctic month is -10 degrees Celsius.

Large areas of the ice pack can be up to 3-4 metres thick, with ridges up to 20 metres. Despite this, ice at this Arctic end of the world is not nearly as thick as the equivalent polar region at the opposite southernmost end of the Earth, known of course as the ‘Antarctic’.

The Antarctic consists of the continent of Antarctica and ice shelves, waters, and island territories in the South Ocean.  In contrast with floating pack ice (this “sea ice” is typically less than 3 metres thick), an ice shelf is a much thicker floating platform of ice (100-1000 metres thick) that forms where a glacier or ice sheet flows down a coastline onto the ocean surface.

For some time, scientists have been concerned about the threat to sea levels from melting in the Arctic region.  Despite the fact that Arctic ice has a natural melting cycle - in which half of the ice pack melts away in the summer, to freeze back again in the winter - a previous study revealed that the 3-4 metre thick ice is melting so fast that half of it will disappear by the end of the century.  Further studies have suggested that the whole northern Arctic region could be without ice during the summer months in less than a century.

Until now scientists have largely dismissed concerns about melting in  the world’s biggest ice sheet located in the South, namely at the East Antarctic, due to the extremely cold temperatures in that region (which can drop below minus 30 degrees Celsius at the coast). However, a study by British scientists has now identified three significant patterns in the size of glaciers in this region which coincide with changes in temperature.

A team from the Department of Geography at Durham University collated measurements from 175 ‘ocean-terminating glaciers’ - where they meet the sea - along 5,400km of the   East Antarctic Ice Sheet’s coastline.  The measurements were obtained from declassified spy satellite imagery, covering almost half a century (from 1963 - 2012). The data was used to create the first long term record of changes at glacier edges in this region.

The research identified three significant patterns:  

       The 1970s-80s, when temperatures were rising, and most glaciers retreated

·            In the 1990s, when temperatures decreased, most glaciers advanced

·         In the 2000s, when temperatures increased and then decreased, there was a more even mix of retreat and                   advance

Lead researcher, Dr Chris Stokes, noted that the patterns identified were distinct from the natural cycles of advance and retreat triggered by the process of large icebergs breaking off at the terminus which happens independently of climate change.

Commenting on the patterns, he said: “It was a big surprise therefore to see rapid and synchronous changes in advance and retreat, but it made perfect sense when we looked at the climate and sea-ice data.”

Dr Stokes cautioned that:  “If the climate is going to warm in the future, our study shows that large parts of the margins of the East Antarctic Ice Sheet are vulnerable to the kinds of changes that are worrying us in Greenland and also in West Antarctica - acceleration, thinning and retreat.”

The alarming picture is of melting of both polar regions in proximal time frames under the impact of climate change. Welcome to water world.

This research has been published in the journal Nature.

New drive to improve dementia diagnosis rates

The Secretary of State for Health, Jeremy Hunt, has announced new plans by NHS England to improve dementia diagnosis rates over the next two years. Parliamentary Yearbook reports on the new drive which is to be led by local Clinical Commissioning Groups, working with local health and wellbeing boards.  

The Health Secretary Jeremy Hunt has described current levels of dementia diagnosis rates as “shockingly low”. They stand at approximately 45%, which is lower than diagnosis figures for Scotland and Northern Ireland. Under a new initiative, Mr Hunt has announced a drive to completely overhaul dementia diagnosis.  The plans aim to see two thirds of people with dementia identified and given support by 2015 with diagnosis rates rising by over 20%.

More than half of people living with dementia have not received a diagnosis. Figures show that currently only 350,000 of an estimated 670,000 people living with dementia have been diagnosed. Commenting on this, Alzheimer’s Society Chief Executive Jeremy Hughes said: “It’s disgraceful that almost half of all people with dementia are not receiving a diagnosis, and disappointing to see such a disparity in rates in different regions of the UK.”

The issue is important. One in three people over the age of 65 will suffer with dementia, and with number of suffers set to double in the next 30 years costs are expected to rise to £19 billion.  According to NHS England, “improved diagnosis will be key if the system is to cope effectively with the predicted surge in numbers”.

In recent years the issue has become an increasing priority. In 2009, the Labour government published the National Dementia Strategy. This strategy set new standards for dementia care, focusing on better education and understanding of dementia, early diagnosis and support, and services for people and their carers living with dementia.

Under the current administration, Prime Minister David Cameron subsequently launched the Dementia Challenge in March last year.  This set out plans to make further improvements in dementia care. There are three strands, which aim to: improve care, promote public support and understanding of dementia, and encourage research. Three champion groups oversee the Dementia Challenge. Their latest annual progress report set out their shared ambition that: “By 2015, we want to see significant increases in research funding, diagnosis rate and the number of dementia friendly communities.”

As the Prime Minister’s Challenge on Dementia has reached the end of its first year the Health Secretary announced the new drive to overhaul dementia diagnosis rates. To this end, the government is working with NHS England to put together guidance for local NHS services on improving diagnosis rates. 

The focus will be on correcting what NHS calls “the existing postcode lottery on diagnosis”.  Under new plans, the aim is to see two thirds of people with dementia identified and given support.  This will see an extra 160,000 people diagnosed in 2015 compared with numbers diagnosed this year. Commenting on the plans, Jeremy Hunt said: “I am pleased that NHS England has set a clear direction and sent a message to the NHS that we must do more.”

A number of organisations will be at the forefront of the project. Crucial to success will be the co-operation of local Clinical Commissioning Groups, working with local Health and Wellbeing Boards. Dr Martin McShane, Director of NHS England, acknowledged that diagnosis was the first step to accessing care and support.  Emphasising the collaborative nature of the plans, he said:  “We relish the opportunity to share best practice and effective ways of meeting the needs of people with dementia once diagnosed with our colleagues in Clinical Commissioning Groups and Health and Wellbeing Boards.”

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New hope for treating antibiotic resistant bacteria

Parliamentary Yearbook examines new research which suggests that adding silver to antibiotics makes them one thousand times more effective at fighting infections.  It is hoped that the findings could help in the fight against antibiotic resistance.

Silver has been used as an antimicrobial for centuries. Despite this widespread use, the exact mechanism of its action has remained unclear. New research by a team of American scientists has been published in the journal Translational Medicine which identifies exactly how silver fights bacteria in a number of ways.  The research suggests that adding silver to existing anitbiotics could help strengthen the antibiotic arsenal for fighting bacterial infections.

Silver has been used to fight infections for thousands of years.   Hippocrates first described its antimicrobial properties in 400 b.c.; noting its special ability to preserve food and water. Today silver is routinely used to treat and prevent infections and can be found in wound dressings and catheters but the source of this precious metal’s antibacterial properties has remained a mystery.  In this latest research, James Collins, of the Wyss Institute for Biologically Inspired Engineering at Harvard University and colleagues from Boston University, describe a number of ways in which silver fights bacteria.   

The study is important because it investigates the effects of silver on E.coli, a Gram-negative bacterium. The most difficult types of infections to are those that involve Gram-negative bacteria, like E.coli and Salmonella.  These bacterial strains have an almost impenetrable cell wall that shields them from antibiotics.  They are resistant to multiple drugs and are increasingly resistant to most available antibiotics.  Gram-negative bacteria have built-in abilities to find new ways to be resistant and can pass along genetic materials that allow other bacteria to become drug-resistant as well. 

The research team conducted a series of experiments using E.coli in petri dishes and in live mice suffering from urinary tract infections.  The study aimed to investigate exactly how silver kills Gram-negative bacteria. 

The findings show that silver mounts a multi-targeted attack on the bacteria which breaks down their cells walls and increases their production of reactive oxygen species (ROS), chemically reactive molecules containing oxygen.  An increase in ROS molecules, caused by traditional antibiotics or silver automatically triggers bacterial cell death.

The researchers subsequently investigated the effects of combining silver with a range of antibiotics. They found that the silver acted as a sort of Trojan horse.  It helped to deliver the treatment beyond the cells’ walls which allowed the antibiotic to maximally damage the bacterial cells. 

The findings were remarkable.  They showed that antibiotics, when combined with silver, were 10 to 1,000 times more effective at fighting infections than when antibiotics alone were used. Even at small doses, silver made the E.coli up to one thousand times more sensitive to gentamycin, ofloxacin and ampicillin; three widely used antibiotics.

In further tests with mice, they found that a E.coli urinary tract infection that was resistant to tetracycline finally succumbed when the antibiotic was combined with silver.  Similarly, they found that, combined with silver, vancomyin saved the lives of 90% of mice with life-threatening peritonitis. Treated with vancomycin alone, 90% of the mice died.

The doses of silver used used in the experiments were tested to ensure they were not toxic.  The team showed that levels were too low to harm the mice. It was also confirmed that levels used did not harm human cells.

The researchers believe that silver may enable existing antibiotics to treat a wider range of infections, including those to which microbes have become resistant.

Commenting on the research, Jim Collins said:  “We’re keen to explore how smart drug-delivery nanotechnologies being developed at the Wyss could help deliver effective but nontoxic levels of silver to sites of infection.”

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