Beyond the Nobel: What scientists are learning about how your brain navigates

Edvard and May-Britt Moser's discoveries - in particular the "grid
cells" - which the magazine Science described as the most important finding
in the field for two decades - are quite remarkable.

They have shown how the brain calculates the position of the organism in its spatial environment, completely overturning prior conventional thinking in the field.

From BBC by James Gallagher

The Nobel Prize for physiology or medicine has been awarded to three scientists who discovered the brain's "GPS system".

UK-based researcher Prof John O'Keefe as well as May-Britt Moser and Edvard Moser share the award.
They discovered how the brain knows where we are and is able to navigate from one place to another.
Their findings may help explain why Alzheimer's disease patients cannot recognise their surroundings.
"The discoveries have solved a problem that has occupied philosophers and scientists for centuries," the Nobel Assembly said.

Place cells, discovered by John O’Keefe, reside in the brain’s hippocampus and become active when a rat is in a certain spot. In the nearby entorhinal cortex, grid cells, discovered by May-Britt Moser and Edvard Moser, fire at regularly spaced intervals as an animal moves through space, forming a hexagonal pattern. (see illustration)

Inner GPS

Prof O'Keefe, from University College London, discovered the first part of the brain's internal positioning system in 1971.
On hearing about winning the prize, he said: "I'm totally delighted and thrilled, I'm still in a state of shock, it's the highest accolade you can get."

His work showed that a set of nerve cells became activated whenever a rat was in one location in a room.
A different set of cells were active when the rat was in a different area.
Prof O'Keefe argued these "place cells" - located in the hippocampus - formed a map within the brain.
He will be having a "quiet celebration" this evening and says the prize money "should be used for the common good".

Mapping

In 2005, husband and wife team, May-Britt and Edvard, discovered a different part of the brain which acts more like a nautical chart.
These "grid cells" are akin to lines of longitude and latitude, helping the brain to judge distance and navigate.

They work at the Norwegian University of Science and Technology in Trondheim.
Prof May-Britt Moser said: "This is crazy, this is such a great honour for all of us and all the people who have worked with us and supported us."
The Nobel committee said the combination of grid and place cells "constitutes a comprehensive positioning system, an inner GPS, in the brain".

They added: "[This system is] affected in several brain disorders, including dementia and Alzheimer's disease.
"A better understanding of neural mechanisms underlying spatial memory is therefore important and the discoveries of place and grid cells have been a major leap forward to advance this endeavour."

'Cognitive revolution'

Dr Colin Lever, from the University of Durham, worked in Prof O'Keefe's laboratory for ten years and has already dreamt on two occasions that his former mentor had won the award.

He told the BBC: "He absolutely deserves the Nobel Prize, he created a cognitive revolution, his research was really forward thinking in suggesting animals create representations of the external world inside their brains."
"Place cells help us map our way around the world, but in humans at least they form part of the spatiotemporal scaffold in our brains that supports our autobiographical memory.
"The world was not ready for his original report of place cells in 1971, people didn't believe that 'place' was what best characterised these cells, so there was no great fanfare at that time.
"But his work on hippocampal spatial mapping created the background for discovering grid cells and with grid cells, the world was prepared and we all thought wow this is big news."

Links :

• Wired : Beyond the Nobel: What Scientists Are Learning About How Your Brain Navigates
• NYTimes : Nobel Prize in Medicine Is Awarded to Three Who Discovered Brain’s ‘Inner GPS’
• NYTimes : Is GPS All in Our Heads?
• BostonGlobe : Do our brains pay a price for GPS?
• NPR : The GPS in your head may work a lot better than that phone

Different depths reveal ocean warming trends

 Inaccurate temperature readings of Southern Hemisphere oceans have led to global warming being underestimated.

The team studied rising temperatures of the southern hemisphere over the decades between 1970 and 2004, and recommended increasing estimates of the rate of ocean warming by between 48% and 152%.

From BBC by Jonathan Webb

The deeper half of the ocean did not get measurably warmer in the last decade, but surface layers have been warming faster than we thought since the 1970s, two new studies suggest.

Because the sea absorbs 90% of the heat caused by human activity, its warmth is a central concern in climate science.
The new work suggests that shallow layers bear the brunt of ocean warming.
Scientists compared temperature data, satellite measurements of sea level, and results from climate models.
Both the papers appear in the journal Nature Climate Change.

The Antarctic Ocean is a remote place where icebergs frequently drift off the Antarctic coast and can be seen during their various stages of melting.

This iceberg, sighted off the Amery Ice Shelf, also has bands of translucent blue ice formed by sea or freshwater freezing in bands between layers of more compressed and white glacial ice.

Image by Andrew Meijers/BAS

Underestimation
 
Specifically in the Southern Hemisphere where fewer measurements have been made, a team of researchers from the Lawrence Livermore National Laboratory in California investigated long-term warming in the top 700m of the ocean.

They wanted to compare published warming rates, based on the sparse temperature data recorded directly from southern waters, with what could be predicted based on more detailed observations in the north, together with climate models and precise sea-level measurements.

Sea levels across the planet are accurately assessed by satellites, which bounce radio waves off the ocean surface.
And sea level changes are closely related to ocean temperature, because the water expands as it warms up.

By combining these calculations, the scientists found that the rate of upper-ocean warming between 1970 and 2004 had been seriously underestimated.
That inaccuracy is specific to the Southern Hemisphere, but is big enough, the scientists suggest, that global upper-ocean warming rates are also "biased low" - to the tune of 24% to 55%.
The researchers say the underestimation probably arose simply from the scarcity of measurements in the south.
"It's likely that due to the poor observational coverage, we just haven't been able to say definitively what the long-term rate of Southern Hemisphere ocean warming has been," said lead author Dr Paul Durack.
"It's a really pressing problem - we're trying as hard as we can, as scientists, to provide the best information from the limited observations we have."

Dr Jan Zika, an oceanographer at the University of Southampton, agreed that Dr Durack's work highlighted the need for more data.
"It could be that the heat uptake by the ocean is a stronger contribution than we previously thought," he told BBC News.
Storage of heat in the oceans is the best explanation scientists have for the recent "'slowdown'" in the rise of global surface temperatures.
Dr Zika added that the heat content of shallow layers is a particular concern, as that warmth is more likely to return to the atmosphere.
"If it were getting really deep down, then we might think that it's basically stuck there," he said.

Obscure depths
 
Meanwhile, at depths greater than 2km, temperatures appear relatively stable - at least as far as changes can be detected.
That was the outcome of the second study, in which a team from the California Institute of Technology made thorough use of the vastly improved data coverage that has been delivered by the Argo programme of remote, floating probes.

 Akin to having a fleet of miniature research vessels, the global flotilla of more than 3,600 robotic profiling floats provides crucial information on upper layers of the world's ocean currents.
Photo by Alicia Navidad/CSIRO.

These devices started to be deployed in 1999 and there are now more than 3,600 of them adrift in our planet's oceans.

Argo "floats" only record temperatures down to about 2km beneath the surface, so the Caltech researchers used that information to calculate the overall amount of heat absorbed by the upper 2km of the oceans (approximately the top half).
Then, by subtracting that quantity of heat from the total ocean warming indicated by satellite observations of sea level, they estimated how much the deeper half of the ocean (below 2km) had warmed up.
The result: once the high level of uncertainty associated with the calculations was taken into account, there was no change detected in the deep.
"Combining those different observations, we ended up with a large uncertainty in our estimate," explained Dr William Llovel, the study's lead author.
"But on the other hand, it is a global estimate. We're not using just a few observations from the deep ocean itself."

 Global mean sea-level variations :

The estimates are observed variations by satellite altimetry (blue), ocean mass contributions based on GRACE data (solid black) and steric sea level based on in situ observations (red).

In a commentary for Nature Climate Change, Dr Gregory Johnson and Dr John Lyman, both from the National Oceanic and Atmospheric Administration in Seattle, US, said the results pointed to a crucial gap in ocean measurements.
They suggested that clearer conclusions would come from the next generation of floating probes, known as Deep Argo.
The first such device was launched in 2013 and plunged 6km beneath the waves off Puerto Rico; two other prototypes were deployed off the New Zealand coast in June 2014.
"It is time to close the deep-ocean measurement gap and reduce the uncertainties in global planetary energy and sea-level budgets," wrote Dr Johnson and Dr Lyman.

Dr Zika agrees. "There are very clear, very plausible explanations for how the ocean could be taking up heat and offsetting global warming," he told the BBC.
"But to attribute exactly where that heat's going, and whether it'll pop back out or not, is going to take more observations. We need to get those in place."

Adapting to a Changing Ocean: A Global Society Perspective

David Victor is a professor of international relations and director of the Laboratory on International Law and Regulation at UC San Diego.

His research focuses on highly regulated industries and how regulation affects the operation of major energy markets.

He is the author of Global Warming Gridlock, which explains why the world hasn’t made much diplomatic progress on the problem of climate change and the search for new strategies.

Links :

• Climate Central : Oceans getting hotter than anybody realized

NZ Linz update in the Marine GeoGarage

Coverage NZ Linz Marine GeoGarage layer

As our public viewer is not yet available
(currently under construction, upgrading to Google Maps API v3 as v2 is officially no more supported),
this info is primarily intended to our iPhone/iPad universal mobile application users
(Marine NZ on the App Store) 
and our B2B customers which use our nautical charts layers
in their own webmapping applications through our GeoGarage API.  

5 charts has been updated in the Marine GeoGarage

(Linz September update published October 3rd, 2014 (Updated to NTM Edition 19)

• NZ541 Mayor Island to Okurei Point
• NZ542 Motiti Island to Pehitari Point
• NZ5113 Plans in Rangaunu Bay
• NZ5124 Plans in the Bay of Islands
• NZ5413 Approaches to Tauranga

Today NZ Linz charts (183 charts / 323 including sub-charts) are displayed in the Marine GeoGarage.

Note :  LINZ produces official nautical charts to aid safe navigation in New Zealand waters and certain areas of Antarctica and the South-West Pacific.

Using charts safely involves keeping them up-to-date using Notices to Mariners
Reporting a Hazard to Navigation - H Note :
Mariners are requested to advise the New Zealand Hydrographic Authority at LINZ of the discovery of new or suspected dangers to navigation, or shortcomings in charts or publications.

US Navy to deploy armed, robotic patrol boats

From The Telegraph

Technology adapted from Nasa's rovers on Mars could transform how the American navy operates, officials say

The US Navy says it will soon use armed, robotic patrol boats with no sailors on board to escort and defend warships moving through sensitive sea lanes.

The technology, adapted from Nasa's rovers on Mars, will transform how the American navy operates, and is sure to raise fresh questions and concerns about the widening role of robots in warfare.

  During the demonstration as many as 13 Navy boats, using an ONR-sponsored system operated autonomously or by remote control during escort, intercept and engage scenarios.

The Office of Naval Research on Sunday released the results of what it called an unprecedented demonstration in August involving 13 robotic patrol craft escorting a ship along the James River in Virginia.

In a simulated scenario, five of the robotic patrol boats guarded a larger ship, while eight others were ordered to investigate a suspicious vessel.

The unmanned patrol boats then encircled and swarmed the "target," enabling the mother ship to move safely through the area.

 This Tuesday Aug. 12, 2014 photo provided by the U.S. Navy shows an unmanned 11-meter rigid hulled inflatable boat (RHIB) from Naval Surface Warfare Center Carderock, as it operates autonomously during an Office of Naval Research demonstration of swarmboat technology held on the James River in Newport News, Va

(AP Photo/U.S. Navy, John F. Williams)

The demonstration, conducted over two weeks, was designed to "replicate a transit through a strait," naval research chief Rear Admiral Matthew Klunder told reporters in a recent briefing.
"It could be the straits of Malacca, it could be the straits of Hormuz."
The demonstration was a "breakthrough" that goes far beyond any previous experiment, he said, adding that similar robotic patrol craft likely will be escorting US naval ships within a year.
The patrol craft, 11-yard long vessels known in the military as rigid hulled inflatable boats, are usually operated by three or four sailors.
But outfitted with the robotic system, a single sailor could oversee up to 20 of the vessels.

The inflatable boat operates autonomously

during an Office of Naval Research demonstration of swarmboat technology

There were no shots fired in the demonstration but Rear-Adml Klunder said the robotic craft can be outfitted with non-lethal equipment, such as lights and blaring sound, as well as 50-caliber machine guns.
And the vessels could fire on an enemy ship if ordered to do so by a sailor.
"We have every intention to use those unmanned systems to engage a threat," the admiral said.
"There is always a human in the loop of that designation of the target and if so, the destruction of the target."

For the demonstration, researchers had fail-safe systems in place to avoid any mishaps.
If communications with the patrol craft broke off, the vessels would go "dead in the water," said programme manager Robert Brizzolara.
And if the boats malfunctioned in some way, there were two separate communications links that could be used to halt the vessel.
Unlike drone aircraft, such as the famed Predator and Reaper planes, the robotic boats are more autonomous and can carry out directions without having to be operated by a human at every step.
"The excitement about this technology is it is autonomous," Rear-Adml Klunder said.
"So we're not talking about people having to drive with toggle switches."

The boats move in sync with other unmanned vessels, selecting the best route while sensing obstacles.
The US military sees the innovation as saving sailors' lives and strengthening the navy's edge.
But sceptics have warned of the dangers from the spread of armed robots – without sufficient rules and debate about their use.
The technology, which the navy has dubbed CARACaS, or Control Architecture for Robotic Agent Command and Sensing, is "very low-cost" and can be installed easily on the patrol boats or other ships, Rear-Adml Klunder said.

Eight unmanned high-speed maneuvering surface targets, at right, lead the way as five unmanned surface vehicles escort the Relentless.

"We're talking thousands [of dollars]. We're not talking millions to adapt what we already have – existing craft in our fleet," he added.
"So we're not going out and buying new patrol craft."
Evoking images from science fiction with fleets of robots waging war, Rear-Adml Klunder said the system could eventually be installed on larger naval ships.
And the robotic patrol craft could be used to transport teams of special operation forces, which already use the manned version of the boats.

Other government agencies and private firms are also taking a keen look at the unmanned boats.
"We're putting it out there to save sailors and marines' lives, to protect ships, to protect harbors and ports," Rear-Adml Klunder said.
The military unveiled the technology around the 14th anniversary of the attack on the USS Cole off the coast of Yemen.
The October 2000 attack, in which a small boat with explosives detonated near the US destroyer, killed 17 sailors and wounded 39 others.
"If we had this capability on that day, I'm sure we would have saved that ship," Rear-Adm Klunder said.

Links :

• DefenseOne : Inside the Navy’s secret swarm robot experiment
• Model-predictive asset guarding by team of autonomous surface vehicles in environment with civilian boats 
• Stripes : Navy debuts unmanned robotic boats with new swarm capability 
• US Defense Department unmanned system integrated roadmap 
• IEEE : Navy launches slightly less cool drone from submarine

Image of the week : 35,000 walrus converge on Alaska beach as sea ice retreats

Female Pacific walruses and their calves traditionally spend summers far from shore, diving for benthic invertebrates over the shallow continental shelf waters of the Chukchi Sea.

These female walruses and their calves prefer to rest between forage bouts on sea ice drifting above their feeding grounds.

However, in recent years loss of summer sea ice over the continental shelf has forced many walruses to travel to the northwest coast of Alaska where they haul-out on shore to rest.

This large herd of walruses hauled out near Pt. Lay Alaska in August of 2011.
(USGS)

From CNN by Brad Lendon

Arctic ice is dwindling, the waters of the North Pacific Ocean are the warmest on record and tens of thousands of walruses have taken notice, "hauling out" on an Alaskan beach in numbers never seen before.
Photos taken by scientists working for the National Oceanic and Atmospheric Administration show more than 35,000 walruses gathered, or hauled out, on a beach near the village of Point Lay, on the Chukchi Sea in northwest Alaska on Saturday.

The walruses are forced onto land when sea ice, which they use to rest between dives for food, disappears, according to NOAA. A report on Flight 240 of the Aerial Surveys of Arctic Marine Mammals, run by the National Marine Mammal Laboratory, shows no sea ice spotted on Saturday, but it showed 35,036 walruses on the beach near Point Lay, including 36 dead ones.

The number of walruses had mushroomed from an aerial survey only four days earlier, when just 1,500 were spotted at the haul-out near Point Lay.
About 50 dead walruses were spotted in that count.
A NOAA release from 2013 calls the large haul-outs a relatively new phenomenon.
Last year, a NOAA survey counted about 10,000 walruses on the beach near Point Lay.
In 2011, about 30,000 came ashore.
The large haul-outs were first noticed in 2007, NOAA said. (see USGS)

Aerial photography of a huge group of Pacific walruses that grew to an estimated 35,000, above, on Sept. 27, from 1,500 on Sept. 23, (previous picture).

Credit Corey Accardo/NOAA

"The massive concentration of walruses onshore -- when they should be scattered broadly in ice-covered waters -- is just one example of the impacts of climate change on the distribution of marine species in the Arctic," Margaret Williams, the World Wildlife Fund's managing director of the Arctic program, said in a statement.

Point Lay, near where the walruses gathered, is on the Arctic Ocean coast just above the Bering Sea. The WWF says other large haul-outs have been reported to the west of Alaska on Russian shores.
A report from the National Snow and Ice Data Center on September 22 said Arctic sea ice had reached its lowest extent of the year on September 17, the sixth-lowest amount of Arctic sea ice on record.

Tracking Pacific Walrus: Expedition to the Shrinking Chukchi Sea Ice

"We are witnessing a slow-motion catastrophe in the Arctic," Lou Leonard, vice president for climate change at the WWF, said in a statement last month.
"As this ice dwindles, the Arctic will experience some of the most dramatic changes our generation has ever witnessed. This loss will impact the annual migration of wildlife through the region, threaten the long-term health of walrus and polar bear populations, and change the lives of those who rely on the Arctic ecosystem for their way of life."

This year's ice report and massive walrus haul-out come the same month that a NOAA report said sea surface temperatures across a vast expanse of the North Pacific are 5.4 degrees Fahrenheit (3 degrees Celsius) higher than normal.
"Not since records began has the region of the North Pacific Ocean been so warm for so long," the NOAA report says.
A heat map accompanying the NOAA report shows deep red in the Bering Sea, indicating the biggest difference from normal in that expanse of water.

 

Links :

• The Guardian : Are walrus at risk from climate change?
• USGS : Walrus radio tracking