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Friday, July 3, 2015

How Our Sense of Smell Evolved, Including in Cave Men

A group of scientists led by Dr Kara Hoover of the University of Alaska Fairbanks and including Professor Matthew Cobb of The University of Manchester, has studied how our sense of smell has evolved, and has even reconstructed how a long-extinct human relative would have been able to smell.

The sense of smell plays a decisive role in human societies, as it is linked to our taste for food, as well as our identification of pleasant and unpleasant substances. 


Credit: University of Delaware 

We have about 4 million smell cells in our noses, divided into about 400 different types. There is tremendous genetic variability within and between populations for our ability to detect odours. Each smell cell carries just one type of receptor or 'lock' on it - the smell floats through the air, fits into the 'lock' and then activates the cell.

Most receptors can detect more than one smell, but one, called OR7D4, enables us to detect a very specific smell called androstenone, which is produced by pigs and is found in boar meat. People with different DNA sequences in the gene producing the OR7D4 receptor respond differently to this smell - some people find it foul, some sweet, and others cannot smell it at all. People's responses to androstenone can be predicted by their OR7D4 DNA sequence, and vice versa.

Professor Cobb from The University of Manchester’s Faculty of Life Sciences and the other researchers studied the DNA that codes for OR7D4 from over 2,200 people from 43 populations around the world, many of them from indigenous groups. They found that different populations tend to have different gene sequences and therefore differ in their ability to smell this compound.

For example, they found that populations from Africa - where humans come from - tend to be able to smell it, while those from the northern hemisphere tend not to. This shows that when humans first evolved in Africa, they would have been able to detect this odour.

Statistical analysis of the frequencies of the different forms of the OR7D4 gene from around the world suggested that the different forms of this gene might have been subject to natural selection.

One possible explanation of this selection is that the inability to smell androstenone was involved in the domestication of pigs by our ancestors - andostroneone makes pork from uncastrated boars taste unpleasant to people who can smell it. Pigs were initially domesticated in Asia, where genes leading to a reduced sensitivity to androstenone have a high frequency.

The group also studied the OR7D4 gene in the ancient DNA from two extinct human populations, Neanderthals and the Denisovans, whose remains were found at the same site in Siberia, but who lived tens of thousands of years apart.

The group found that Neanderthal OR7D4 DNA was like our own - they would have been able to smell androstenone. The Denisovans are a mysterious group of our extinct relatives - we do not know what they looked like, and they are known from only one tooth and a finger bone, from different individuals.

Their DNA showed a unique mutation, not seen in humans or Neanderthals, that changed the structure of the OR7D4 receptor.

Team-member Hiroaki Matsunami at Duke University in the USA reconstructed the Denisovan OR7D4 and studied how this tiny part of a long-extinct nose responded to androstenone. It turned out that despite the mutation, the Denisovan nose functioned like our own. Both of our close relatives, like our early human ancestors, would have been able to detect this strange smell.

This research shows how global studies of our genes can give insight into how our taste for different foods may have been influenced by variation in our ability to smell, and, excitingly, show that it is possible to see back into deep evolutionary time and reconstruct the sensory world of our distant ancestors.

The research was carried out by scientists from the University of Alaska Fairbanks, State University of New York, Duke University and The University of Manchester, and is published in the journal Chemical Senses.






Contacts and sources:
Jamie BrownManchester University

Citation:  Kara C. Hoover, Omer Gokcumen, Zoya Qureshy, Elise Bruguera, Aulaphan Savangsuksa, Matthew Cobb and Hiroaki Matsunami, Global Survey of Variation in a Human Olfactory Receptor Gene Reveals Signatures of Non-Neutral Evolution, Chem. Senses first published online June 13, 2015, doi: 10.1093/chemse/bjv030

How Dementia Sufferers Benefit from GPS

A brand new study of 200 dementia sufferers in Norway reveals that almost all experience greater peace of mind and increased levels of physical activity using GPS devices.

The study relates the story of an elderly man residing in the secure ward of a nursing home who was not allowed to go out because he always got lost. He wasted a lot of energy getting up and shaking the door, and minor conflicts always arose when staff had to lead him away.

The study has confirmed that dementia sufferers can maintain their independence, enjoy their freedom and continue to pursue their outdoor activities in spite of the development of their illness. 

Photo: Henning Tunsli

One nurse intervened and decided that during her shift the patient should be given a GPS device and allowed out. The man went for a walk, visited a café, sat for while watching the people go by, and then returned home. If he failed to return, it was easy to find him and bring him back. After a while, three of the patients on this ward were given GPS devices. Things calmed down and staff found that they had more time to take care of those patients who didn't venture out.

Documentation is vital

The study forms part of the public sector innovation projects collectively known as "Trygge Spor og Samspill" (Safe tracking and interaction) – a joint initiative launched in 2011 being carried out by SINTEF together with a number of Norwegian municipalities. The initial project began with five municipalities and 50 dementia sufferers, and in 2015 it was expanded to include 18 municipalities. People with dementia (or cognitive dysfunction) taking part in the study have experience in using the devices varying from three months to two years.

A survey has been incorporated into the study involving device users, next of kin and personnel employed by all of the 18 municipalities as respondents. Interviews have also been conducted. All forms of data can provide useful background information as a basis for the planning and use of GPS technology as part of health care provision in Norway. 

Previously, it has been difficult to substantiate the benefits of using GPS devices, and this is why the documentation of experience reported by municipalities is key to the work currently being carried out.

Independence and peace of mind

"We have seen many positive benefits", say Tone Øderud and Dag Ausen at SINTEF. "The study has confirmed that dementia sufferers can maintain their independence, enjoy their freedom and continue to pursue their outdoor activities in spite of the development of their illness", they say.

More or less all respondents to the survey (next of kin, GPS users, health service providers and staff at out-patient clinics and nursing homes) say that the GPS devices give them greater peace of mind. Staff at the clinics and homes experience fewer conflicts and waste less time and effort in redirecting patients and keeping order on the wards. 

Moreover, the technology can result in financial savings in cases where sufferers are able to live for longer at home or can reside in open, as opposed to secure, nursing home wards. Only very few feel that they are under surveillance.

There is also the direct benefit of enabling next of kin carers to spend more time at work.

Who benefits?

During the three years that SINTEF researchers have been gathering data from the municipalities, they have acted as project supervisors and have obtained a wealth of research-based insights.

"It is vital to identify who is best suited to use the GPS devices", says Tone Øderud. "This type of technology doesn't suit everyone", she says. The municipalities are currently carrying out a survey with the aim of identifying and establishing an overview of their GPS users. Who are the users? Where do they live? Why were they given the technology? How is the service set up? Guidelines provided here may make it possible to weed out those who will not benefit from the technology.

"It's important to realise that not every municipality has to have the same experiences or dedicate resources to these issues", says Ausen. "For example, we know that Drammen municipality has worked with this issue for some time and has become increasingly more adept at 'getting it right'. When a candidate is identified and registered with a request for a GPS device, municipal staff can decide quickly as to whether or not he or she will benefit from the technology. In some cases, a municipality has been able to postpone transfer to a nursing home by as much as six months", he says.

Extending a good life

Not all the GPS users in the study have received a dementia diagnosis, but all are suffering from dementia-related problems with cognitive dysfunction.

The assistance provided by a GPS device will not last in the long term. Nevertheless, its function is important to sufferers for as long as it works", says Dag Ausen. "So far during the study the average period of use has been between 10 and 11 months", he says.

The study reveals that between 20 and 25% of sufferers who report benefits from using GPS also obtain a direct benefit from being able to live longer at home. If their functioning deteriorates to the extent that they are unable to live at home, they can nevertheless reside in an open ward in a nursing home.

"For younger dementia sufferers, the use of a GPS device means that a spouse can spend more time at work and plan their day-to-day routines better", says Øderud.

She tells the story of a younger couple taking part in the study in which the wife became worried when her husband started getting lost on his journey home. She wanted him to have a GPS device, but at first he didn't feel he needed it. Today, she can go to work while her husband spends his mornings going for walks or cycling with his GPS device. If he doesn't get home for dinner, she can find out where he is. By then he will be tired and exhausted.

The couple have been granted the technology by the municipality as a preventive measure. This can be particularly useful for young and fit people who want to keep active.

Regular routines

In conclusion, there is no doubt that people suffering from dementia who would still rather go out than sit inside can live an active life much as they did before, and as safely as possible.

The study provides evidence that it is important that dementia sufferers, their next of kin carers, and professional care providers all work together. This ensures that the GPS technology works successfully, and means that dementia sufferers can be located in an appropriate manner.

The researchers emphasise that it is important to establish regular routines. Most sufferers find it useful to have the GPS device by the door, and then hang it round their neck or put it in their pocket when they go out. Some have learned how to charge their devices, while others rely on next of kin or visiting nurses for supervision and assistance.

Close supervision is important for GPS users, and it varies from person to person as to who they think can help them best among their next of kin, social services, volunteers and suchlike. The most important thing is that roles are clearly defined and the service robust.


Contacts and sources:
SINTEF

New Lithium Ion Battery Is Safer, Tougher, and More Powerful

Lithium ion batteries (LIBs) are a huge technological advancement from lead acid batteries which have existed since the late 1850’s. Thanks to their low weight, high energy density and slower loss of charge when not in use, LIBs have become the preferred choice for consumer electronics. 

 Lithium-ion cells with cobalt cathodes hold twice the energy of a nickel-based battery and four-times that of lead acid. Despite being a superior consumer battery, LIBs still have some drawbacks. Current manufacturing technology is reaching the theoretical energy density limit for LIBs and overheating leading to thermal runaway i.e. “venting with flame” is a serious concern.

Simple incorporation of various lithium precursor to porous CB[6] exhibits high lithium ion conductivities, mobility and safer dried solid lithium electrolytes


South Korean researchers at the Center for Self-assembly and Complexity, Institute for Basic Science (IBS), Department of Chemistry and Division of Advanced Materials Science at Pohang University, have created a new LIB made from a porous solid which greatly improves its performance as well as reducing the risks due to overheating.

Since 2002 there have been over 40 recalls in the US alone due to fire or explosion risk from LIBs used in consumer electronic devices. These types of batteries, in all of their different lithium-anode combinations, continue to be an essential part of modern consumer electronics despite their poor track record at high temperatures.

The Korean team tried a totally new approach in making the batteries. According to Dr. Kimoon Kim at IBS, “we have already investigated high and highly anisotropic [directionally dependent] proton conducting behaviors in porous CB[6] for fuel cell electrolytes. It is possible for this lithium ion conduction following porous CB[6] to be safer than existing solid lithium electrolyte -based organic-molecular porous-materials utilizing the simple soaking method.” 

Current LIB technology relies on intercalated lithium which functions well, but due to ever increasing demands from electronic devices to be lighter and more powerful, investigation of novel electrolytes is necessary in order.

The new battery is built from pumpkin-shaped molecules called cucurbit[6]uril (CB[6]) which are organized in a honeycomb-like structure. The molecules have an incredibly thin 1D-channel, only averaging 7.5 Å [a single lithium ion is 0.76 Å, or .76 x 10-10 m] that runs through them. The physical structure of the porous CB[6] enables the lithium ions to battery to diffuse more freely than in conventional LIBs and exist without the separators found in other batteries.

In tests, the porous CB[6] solid electrolytes showed impressive lithium ion conductivity. To compare this to existing battery electrolytes, the team used a measurement of the lithium transference number (tLi+) which was recorded at 0.7-0.8 compared to 0.2-0.5 of existing electrolytes. They also subjected the batteries to extreme temperatures of up to 373 K (99.85° C), well above the 80° C typical upper temperature window for exiting LIBs. In the tests, the batteries were cycled at temperatures between 298 K and 373 K ( 24.85° C and 99.85° C) for a duration of four days and after each cycle the results showed no thermal runaway and hardly any change in conductivity.

Various conventional liquid electrolytes can incorporate in a porous CB[6] framework and converted to safer solid lithium electrolytes. Additionally, electrolyte usage is not limited to use only in LIBs, but a lithium air battery potentially feasible. What makes this new technique most exciting is that it is a new method of preparing a solid lithium electrolyte which starts as a liquid but no post-synthetic modification or chemical treatment is needed.


Contacts and sources:
By Daniel Kopperud
Institute for Basic Science


Citation: Jun Heuk Park, Kyungwon Suh, Md. Rumum Rohman, Wooseup Hwang, Minyoung Yoon and Kimoon Kim, (2015), “Solid lithium electrolytes based on an organic molecular porous solid”, The Royal Society of Chemistry, DOI: 10.1039/c5cc02581h

A Stretchy Mesh Heater for Sore Muscles

If you suffer from chronic muscle pain a doctor will likely recommend for you to apply heat to the injury. But how do you effectively wrap that heat around a joint? Korean Scientists at the Center for Nanoparticle Research, Institute for Basic Science (IBS) in Seoul, along with an international team, have come up with an ingenious way of creating therapeutic heat in a light, flexible design.

To ensure that the material remains tight on the target area while heating, the team devised a 2-D interlocking coil pattern for the mesh structure. To make the mesh, the liquid mixture was poured into a shaped mold. The silver-elastic mesh was sandwiched between a top and bottom layer of soft, thin insulation.
Credit: Institute for Basic Science

Other teams have come up with similar devices before, although no one was able to create something that didn’t rely on exotic materials or a complex fabrication process, factors which both carry hefty price tags. Unlike their predecessors, the team at IBS stayed away from things like carbon nanotubes and gold and looked at a more utilitarian option for their build material: thin slivers of silver nanowires.

The silver nanowires are tiny, averaging ∼150 nm in diameter and ∼30 μm in length (a human hair ranges from 17 to 181 µm). The nanowires were mixed into a liquid elastic material which is both soft and stretchy when dry.

(Left: mesh in a relaxed state Right: Mesh stretched over a curve to 100%)

Credit: Institute for Basic Science

To ensure that the material remains tight on the target area while heating, the team devised a 2-D interlocking coil pattern for the mesh structure. To make the mesh, the liquid mixture was poured into a shaped mold. The silver-elastic mesh was sandwiched between a top and bottom layer of soft, thin insulation.

In material flexibility tests, while placed on knee and wrist joints, the mesh heated while deformed and under stress on knee and wrist joints. It is lightweight, breathable and generates heat over the entire surface area of the material. A hot water bottle used for treating muscle soreness feels good, but it will inevitably cool down while in use. 

 Commercially available electric heating pads are sufficient for applying heat to an injured area but their cords need to be attached to an A/C outlet to work. This is where the new technology trumps the old. The mesh maintains a constant temperature instead of cooling down during use and is battery powered so it doesn’t need an outlet.

Beyond thermotherapy, the applications are endless. This technology could be used as a lightweight heating element in ski jackets, or as a hyper-efficient seat warmer in a car. Although only flat mesh connected into a tube has been made so far, it isn’t a stretch to imagine creating more intricate designs like the shape of a hand with detailed fingers.


Contacts and sources:
By Daniel Kopperud
Institute for Basic Science


Citation: Suji Choi, Jinkyung Park, Wonji Hyun, Jangwon Kim, Jaemin Kim, Young Bum Lee,Changyeong Song, Hye Jin Hwang, Ji Hoon Kim, Taeghwan Hyeon, and Dae-Hyeong Kim, (2015), “Stretchable Heater Using Ligand-Exchanged Silver Nanowire Nanocomposite for Wearable Articular Thermotherapy”, American Chemical Society, DOI: 10.1021/acsnano.5b02790

Panel Turns Window into a Solar Cell to Recharge Electronic Devices

The researcher Sandra Casillas from the Technological Institute of La Laguna (ITL), in the north of Mexico, has managed to patent 20 projects, and an example of her work is the design of two Tandem cells that turns windows into a solar panel capable of capturing up to eight volts per square meter of light and allows to recharge electronics. It is also transparent, allowing visibility.

Credit:  Investigación y Desarrollo

Sandra Casillas, professor of the ITL in Torreon, Coahuila (northern state of Mexico) explains that for this project she combined two materials to create the cells and increase effectiveness when capturing energy. The first is made of copper and zinc, and the second of selenium and tellurium, the latter is more efficient due to the conducting characteristics of metals.

Its benefits are instant, just by placing it in the window and connecting both copper wires allows to make use of energy. The Tandem cells are 30 percent cheaper than conventional ones and only sold in Europe, referred to specialist.

Credit:  Investigación y Desarrollo

She adds that the square meter will cost 350 pesos, cheap compared to solar cells that increase the price because they need space to store energy.

The researcher says that creating the film of the cell was based on food packages, which consist of three layers. "We use this technology in the Tandem cell to generate transparent polymer layers".

She took as a reference the plastic SBS (Styrene-Butadiene-Styrene), which allows the passage of oxygen on both sides of the glass and allows to see through it, even if there is much humidity in the room it does not bead up. "What we did was to put nanoparticles of different materials and between the glass and the cell we placed a magnesium tunnel that stops the window from heating".

The specialist in materials engineering relates that this material was used after the attacks of September 11 in the United States. "The Americans did not like receiving vegetables in a packaging with holes, we used to send wrapped lettuce with polyethylene, which has those little holes to prevent oxidation, but had to resort to engineering to use another material with the same function, then the SBS came, it looks like polyethylene but allows the passage of oxygen and preserves vegetables".

Sandra Casillas, who organizes the Expo Science in Coahuila, and the north of Durango, says that there is little financial support for research at the upper secondary level and the industry at Torreon was who contributed to make the projects.

Such is the case of the Peñoles Industry (producer of minerals), which provided magnesium, selenium and tellurium metals for the two Tandem cells; however, the project has just received funding from the National Fund for Scientific Research and Technology (FONCyT), income spent on making the latest laboratory tests and obtain patents. (Agencia ID)


Contacts and sources:  
Investigación y Desarrollo

GHOST: Computer Screens That Change Shape for 3D Design - Video

Exciting new technologies, which allow users to change the shape of displays with their hands, promise to revolutionise the way we interact with smartphones, laptops and computers. Imagine pulling objects and data out of the screen and playing with these in mid-air.

Towards Rapid Prototyping with Shape-Changing Displays for Designers
Credit: © GHOST
Today we live in a world of flat-screen displays we use all day – whether it’s the computer in the office, a smartphone on the train home, the TV or iPad on the couch in the evening. The world we live in is not flat, though; it’s made of hills and valleys, people and objects. Imagine if we could use our fingertips to manipulate the display and drag features out of it into our 3D world.

Credit:   Københavns Universitets  

Such a vision led to the launch in January 2013 of GHOST (Generic, Highly-Organic Shape-Changing Interfaces), an EU-supported research project designed to tap humans’ ability to reason about and manipulate physical objects through the interfaces of computers and mobile devices.

‘This will have all sorts of implications for the future, from everyday interaction with mobile phones to learning with computers and design work,’ explained GHOST coordinator Professor Kasper Hornbæk of the University of Copenhagen. ‘It’s not only about deforming the shape of the screen, but also the digital object you want to manipulate, maybe even in mid-air. Through ultrasound levitation technology, for example, we can project the display out of the flat screen. And thanks to deformable screens we can plunge our fingers into it.’

Shape-changing displays you can touch and feel

This breakthrough in user interaction with technology allows us to handle objects, and even data, in a completely new way. A surgeon, for instance, will be able to work on a virtual brain physically, with the full tactile experience, before performing a real-life operation. Designers and artists using physical proxies such as clay can mould and remould objects and store them in the computer as they work. GHOST researchers are also working with deformable interfaces such as pads and sponges for musicians to flex to control timbre, speed and other parameters in electronic music.

Indeed, GHOST has produced an assembly line of prototypes to showcase shape-changing applications. ‘Emerge’ is one which allows data in bar charts to be pulled out of the screen by fingertips. The information, whether it’s election results or rainfall patterns, can then be re-ordered and broken down by column, row or individually, in order to visualise it better.

The researchers have also been working with ‘morphees’, flexible mobile devices with lycra or alloy displays which bend and stretch according to use. These can change shape automatically to form screens to shield your fingers when you type in a pincode, for example, or to move the display to the twists and turns of a game. And such devices can be enlarged in the hand to examine data closer and shrunk again for storing away in a case or pocket.

Tactile technology reaching the market

One of the GHOST partners, the University of Bristol, has spun off a startup, now employing 12 people, called UltraHaptics, to develop technology being studied in GHOST that uses ultrasound to create feeling in mid-air. The company has attracted seed investment in the UK and further funding from the Horizon 2020 programme.

‘GHOST has made a lot of progress simply by bringing the partners together and allowing us to share our discoveries,’ commented Prof Hornbæk. ‘Displays which change shape as you are using them are probably only five years off now. If you want your smartphone to project the landscape of a terrain 20 or 30 cm out of the display, that’s a little further off - but we’re working on it!’

GHOST, which finishes at the end of this year, involves four partners in the United Kingdom, Netherlands and Denmark, and receives EUR 1.93 million from the EU’s Future and Emerging Technologies programme.

Link to project's website: http://www.ghost-fet.com/


Contacts and sources:
CORDIS




5G: Mobile Traffic Data Thousand-Fold Growth by 2020

Mobile data traffic is expected to grow hundred- or thousand-fold by 2020, when the new 5G telecoms standards are due to enter the market. As the race is on to come up with new solutions for telecoms networks to accommodate this massive growth, one EU research project has already developed an ultra-fast solution using optical transmission technology.

Credit: Thinkstock

LIGHTNESS, an industry-driven EU research project that started back in 2012, was set up to strengthen European technology for connecting data centres and anticipate the growing traffic between them. It is doing this by harnessing the improved power, speed and cost-efficiency of optical (over electrical) transmission.

‘The infrastructure we develop must scale upwards for 5G in a way that current grouped Ethernet switches won't be able to,’ explained Matteo Biancani, of Interoute, the telecoms and cloud services provider leading the project. ‘Scalability of the project is really the key word if we are to meet increased future demand.’

Data transmission at the speed of light

Even today’s 4G and 3G networks are seeing great demand for high data throughput and fast response times, due to the increasing use of high-performance computing, as well as cloud and server-side storage applications. This makes the work of the LIGHTNESS project immediately relevant, in addition to anticipating the advent of 5G technologies.

The main aim of LIGHTNESS has been to design innovative photonic switching and transmission techniques to establish high-performance, low-cost interconnects between and inside data centers. Specifically, universities and research facilities participating in the project, in the UK, Netherlands and Spain, have trialled Optical Circuit Switching (OCS) and Optical Packet Switching (OPS) in special test beds. The test beds simulate intra-data centre network environments and test the technology to see if it can fulfill the requirements of emerging applications in terms of ultra-high bandwidth and low network latency.

With scalability in mind, they have carried out a lot of studies and simulations to evaluate the benefits of LIGHTNESS architecture in very large deployments, using more than 100 different wavelength channels at the same time, resulting in bandwidth capacities of multiple terabits/second per fibre link. The use of OCS and OPS technologies together forms the most promising solution to switching huge data flows, literally at the speed of light.

Rates of 40 to 100 gigabits per second

In the test beds, the LIGHTNESS researchers developed an Optical Packet Switch (OPS), which indeed does provide the nanosecond latency that networks will need to respond to the demands of mobile users in the future. They have also trialed a ‘Top-of-Rack (ToR)’ switch, used for linking racks of storage equipment to the OPS/OCS data center network, aggregating traffic in both long-lived and short-lived data flows. LIGHTNESS has successfully tested these operations at speeds that have never before been seen in networks, ranging between 40 and 100 gigabits per second.

Deployment in data centre networks by 2018

Preliminary prototypes from the project were showcased at the European Conference on Networks and Communications in Paris last year, where LIGHTNESS won Best Booth Award in demonstrating its new software-defined Optical Data Centre Network (ODCN).

‘The full implementation of the LIGHTNESS hardware and software prototypes is now ready and is under experimental evaluation and validation in the project testbed. A full concept demonstration will take place next September at the European Conference on Optical Communications in Valencia. We are building equipment for deployment in our data center networks and production will peak in two to three years' time,’ said Matteo.

LIGHTNESS is a Specific Targeted Research Project receiving EUR 2.44 million investment from the EU’s 7th Framework Programme. It involves seven partners in Italy, the Netherlands, Spain and the United Kingdom, and ends in October this year.

Link to project's website: http://www.ict-lightness.eu/


Contacts and sources: 

South Africans Used Milk-Based Paint 49,000 Years Ago Says New Study

An international research team led by the University of Colorado Boulder and the University of Witwatersrand in Johannesburg, South Africa has discovered a milk-and ochre-based paint dating to 49,000 years ago that inhabitants may have used to adorn themselves with or to decorate stone or wooden slabs.

An international research team led by the University of Colorado Boulder and the University of Witwatersrand in Johannesburg, South Africa, has discovered a milk-and ochre-based paint on a small stone flake dating to 49,000 years ago that inhabitants may have used to adorn themselves with or to decorate stone or wooden slabs. The powdered paint mixture was found on the edge of of Sibudu Cave, a rock shelter in northern KwaZulu-Natal, Africa. 
Credit: CU Boulder

While the use of ochre by early humans dates to at least 250,000 years ago in Europe and Africa, this is the first time a paint containing ochre and milk has ever been found in association with early humans in South Africa, said Paola Villa, a curator at the University of Colorado Museum of Natural History and lead study author. The milk likely was obtained by killing lactating members of the bovid family such as buffalo, eland, kudu and impala, she said.

"Although the use of the paint still remains uncertain, this surprising find establishes the use of milk with ochre well before the introduction of domestic cattle in South Africa," said Villa. "Obtaining milk from a lactating wild bovid also suggests that the people may have attributed a special significance and value to that product."

The powdered paint mixture was found on the edge of a small stone flake in a layer of Sibudu Cave, a rock shelter in northern KwaZulu-Natal, Africa, that was occupied by anatomically modern humans in the Middle Stone Age from roughly 77,000 years ago to about 38,000 years ago, said Villa. While ochre powder production and its use are documented in a number of Middle Stone Age South African sites, there has been no evidence of the use of milk as a chemical binding agent until this discovery, she said.

A paper on the subject was published online June 30 in PLOS ONE. Co-authors were from the Italian Institute of Paleontology in Rome, Italy; the University of Geneva in Switzerland; the University of Pisa in Italy; the University of Monte St. Angelo in Naples, Italy; and the University of Oxford in England. The excavation was directed by Professor Lyn Wadley of the University of Witwatersrand, also a paper co-author.

Cattle were not domesticated in South Africa until 1,000 to 2,000 years ago, said Villa. Wild South African bovids are known to separate from the herd when giving birth and usually attempt to hide their young, a behavior that may have made them easy prey for experienced Middle Stone Age hunters, she said.

The dried paint compound is preserved on the stone flake that may have been used as a mixing implement to combine ochre and milk, or as an applicator, said Villa. The team used several high-tech chemical and elemental analyses to verify the presence of casein, the major protein of milk, on the flake.

At both African and European archaeological sites, scientists have found evidence of ochre -- a natural pigment containing iron oxide than can range from yellow and orange to red and brown - dating back 250,000 years. By 125,000 years ago, there is evidence ochre was being ground up to produce a paint powder in South Africa.

It has been proposed the ochre was sometimes combined by ancient Africans with resin or plant gum to use as an adhesive for attaching shafts to stone tools or wooden bone handles, Villa said. It also may have been used to preserve hides and for body paint, she said, noting that a roughly 100,000-year-old ochre-rich compound blended with animal marrow fat was found at the Middle Stone Age site of Blombos Cave in South Africa.

Body painting is widely practiced by the indigenous San people in South Africa, and is depicted in ancient rock art. While there are no ethnographic precedents for mixing ochre with milk as a body paint, the modern Himba people in Namibia mix ochre with butter as a coloring agent for skin, hair and leather clothing, Villa said.



Contact and sources:
Paola Villa
Jim Scott 

Thursday, July 2, 2015

Two Distinct Faces of Pluto, Series of Spots Fascinate Astronomers

New color images from NASA’s New Horizons spacecraft show two very different faces of the mysterious dwarf planet, one with a series of intriguing spots along the equator that are evenly spaced. Each of the spots is about 300 miles (480 kilometers) in diameter, with a surface area that’s roughly the size of the state of Missouri.

Scientists have yet to see anything quite like the dark spots; their presence has piqued the interest of the New Horizons science team, due to the remarkable consistency in their spacing and size. While the origin of the spots is a mystery for now, the answer may be revealed as the spacecraft continues its approach to the mysterious dwarf planet.

“It’s a real puzzle—we don’t know what the spots are, and we can’t wait to find out,” said New Horizons principal investigator Alan Stern of the Southwest Research Institute, Boulder. “Also puzzling is the longstanding and dramatic difference in the colors and appearance of Pluto compared to its darker and grayer moon Charon.”

New Horizons team members combined black-and-white images of Pluto and Charon from the spacecraft’s Long-Range Reconnaissance Imager (LORRI) with lower-resolution color data from the Ralph instrument to produce these views. 

We see the planet and its largest moon in approximately true color, that is, the way they would appear if you were riding on the New Horizons spacecraft. About half of Pluto is imaged, which means features shown near the bottom of the dwarf planet are at approximately at the equatorial line.

If Pluto has clouds, New Horizons can detect them. Both the high-resolution LORRI imager and the Ralph color imager will be used to look for clouds across the face of Pluto during its approach and departure from the planet.

An artist’s conception of clouds in Pluto’s atmosphere.

Credits: JHUAPL

“We’re looking for clouds in our images using a number of techniques,” said science team postdoc Kelsi Singer of the Southwest Research Institute, “If we find clouds, their presence will allow us to track the speeds and directions of Pluto’s winds.”



Contacts and sources:
NASA

Exercise and Artificial Gravity May Lessen Negative Effects of Weightlessness in Space


Astronauts on the International Space Station (ISS) have a number of exercise options, including a mechanical bicycle bolted to the floor, a weightlifting machine strapped to the wall, and a strap-down treadmill. They spend a significant portion of each day working out to ward off the long-term effects of weightlessness, but many still suffer bone loss, muscle atrophy, and issues with balance and their cardiovascular systems.

Swedish astronaut Christer Fuglesang tries out the new centrifuge while MIT professor Larry Young coaches him on.

Photo: Bill Litant/MIT AeroAstro

To counteract such debilitating effects, research groups around the world are investigating artificial gravity — the notion that astronauts, exposed to strong centrifugal forces, may experience the effects of gravity, even in space. Engineers have been building and testing human centrifuges — spinning platforms that, at high speeds, generate G-forces strong enough to mimic gravity. An astronaut, riding in a centrifuge, would presumably feel gravity’s reinforcing effects.

Now engineers at MIT have built a compact human centrifuge with an exercise component: a cycle ergometer that a person can pedal as the centrifuge spins. The centrifuge was sized to just fit inside a module of the ISS. After testing the setup on healthy participants, the team found the combination of exercise and artificial gravity could significantly lessen the effects of extended weightlessness in space — more so than exercise alone.

These illustrations depict how the researchers' new centrifuge could be used in space.

Courtesy of the researchers

Laurence Young, the Apollo Program Professor in MIT’s Department of Aeronautics and Astronautics, says artificial gravity would be a huge benefit for astronauts, particularly those embarking on long-duration space missions, such as a journey to Mars. The risks, he says, are uncertain, but potentially significant.

“With exploration-class missions, like Mars, where you’re gone for three years, you could run the risk of having astronauts not sufficiently conditioned to perform effectively, and also to not be in good health when they finally get to the surface of Mars,” says Young, a former NASA payload specialist. “You really don’t want to send a jellyfish to represent us on another planet.”

Young says a human centrifuge aboard a Mars-bound spacecraft would help keep an astronaut in shape over the many months it would take to get to the Red Planet. He and his colleagues, former graduate students Ana Diaz and Chris Trigg, have published results from their experiments in the journal Acta Astronautica.

Spinning up artificial gravity

The team’s compact centrifuge resembles a rotating metal cage with three main elements: a chair; a cycle ergometer, or the mechanical portion of a stationary bicycle; and a suite of sensors to measure cardiovascular variables such as blood pressure, heart rate, respiration rate, muscle activity, and foot forces.

The researchers conducted experiments to test human responses and exercise performance at varying levels of artificial gravity. The experiments involved 12 healthy subjects, who participated in three sessions, each consisting of a bicycling workout under one of three artificial gravity levels: zero G, in which the centrifuge did not rotate; 1 G, measured at the feet, in which the centrifuge spun at 28 revolutions per minute (rpm); and 1.4 G, also measured at the feet, at 32 rpm.

“When it spins around, we create centrifugal force, which depends on the angular velocity, or how fast we are rotating — the higher the angular velocity, the greater the artificial gravity,” Diaz says.

During each session, participants were asked to pedal for 15 minutes at three workout intensities, or levels of resistance, set by the cycle ergometer. The remaining 10 minutes involved spinning up and slowing down the centrifuge.

Beyond a “universal solution”

After each session, participants filled out a survey to gauge symptoms such as motion sickness and light-headedness. Overall, Diaz found that participants tolerated the experiments well, suffering little motion sickness even while spinning at relatively high velocities. Participants only reported feelings of discomfort while initially speeding up and slowing down.

“During the spinning process, participants were pushed against the chair due to the centrifugal force, making them sit comfortably, and facilitating their leg biomechanics for biking,” Diaz says.

As the researchers increased the centrifuge’s spin, raising its artificial gravity, participants used correspondingly more force to pedal — an unsurprising but encouraging result.

“That tells us that if we use artificial gravity, we’re able to get higher foot forces, and we know higher foot forces are good for bones, and help you generate more bone,” Diaz says. “Even if we expected this, we were able to quantify it and find a relationship between foot forces and artificial gravity.”

Similarly, as artificial gravity intensified, so did participants’ overall cardiovascular activity, a response that Diaz says may be beneficial over the long term.

Young says the study may begin to bridge two seemingly opposing camps: those who believe exercise alone will prevent bone loss, muscle atrophy, and other effects of extended weightlessness, and those who believe in artificial gravity as the solution.

“I think the principal finding here is supporting the conclusion that exercise alone is not a sufficient countermeasure,” Young says. “For the first time, we’re showing there’s a symbiosis when one combines the best aspects of exercise, and the best aspects of artificial gravity. So I feel this is an important demonstration.”

This research was funded in part by the National Space Biomedical Research Institute and a Skoltech/MIT seed grant.



Contacts and sources:
Abby Abazorius 
Jennifer Chu 
MIT News Office

Cosmic Fireworks Expected from Rare Stellar Encounter In 2018 - Video

Astronomers are gearing up for high-energy fireworks coming in early 2018, when a stellar remnant the size of a city meets one of the brightest stars in our galaxy. The cosmic light show will occur when a pulsar discovered by NASA's Fermi Gamma-ray Space Telescope swings by its companion star. Scientists plan a global campaign to watch the event from radio wavelengths to the highest-energy gamma rays detectable.
Credit: NASA's Goddard Space Flight Center

Coming attraction: Astronomers are expecting high-energy explosions when pulsar J2032 swings around its massive companion star in early 2018. The pulsar will plunge through a disk of gas and dust surrounding the star, triggering cosmic fireworks. Scientists are planning a global campaign to watch the event across the spectrum, from radio waves to gamma rays.

Credits: NASA's Goddard Space Flight Center


The pulsar, known as J2032+4127 (J2032 for short), is the crushed core of a massive star that exploded as a supernova. It is a magnetized ball about 12 miles across, or about the size of Washington, weighing almost twice the sun's mass and spinning seven times a second. J2032's rapid spin and strong magnetic field together produce a lighthouse-like beam detectable when it sweeps our way. Astronomers find most pulsars through radio emissions, but Fermi's Large Area Telescope (LAT) finds them through pulses of gamma rays, the most energetic form of light.

J2032 was found in 2009 through a so-called blind search of LAT data. Using this technique, astronomers can find pulsars whose radio beams may not be pointed precisely in our direction and are therefore much harder to detect.

"Two dozen pulsars were discovered this way in the first year of LAT data alone, including J2032," said David Thompson, a Fermi deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Nearly all of them would not have been found without Fermi."

Once they knew exactly where to look, radio astronomers also were able to detect J2032. A team at the Jodrell Bank Centre for Astrophysics at the University of Manchester in the U.K. kept tabs on the object from 2010 through 2014. And they noticed something odd.

"We detected strange variations in the rotation and the rate at which the rotation slows down, behavior we have not seen in any other isolated pulsar," said Andrew Lyne, professor of physics at the University of Manchester. "Ultimately, we realized these peculiarities were caused by motion around another star, making this the longest-period binary system containing a radio pulsar."

The massive star tugging on the pulsar is named MT91 213. Classified as a Be star, the companion is 15 times the mass of the sun and shines 10,000 times brighter. Be stars drive strong outflows, called stellar winds, and are embedded in large disks of gas and dust.

"When we discovered this pulsar in 2009, we noticed that it was in the same direction as this massive star in the constellation Cygnus, but our initial measurements did not give any evidence that either star was a member of a binary system," explained Paul Ray, an astrophysicist at the Naval Research Laboratory in Washington. "The only way to escape that conclusion was if the binary system had a very long orbital period, much longer than the longest known pulsar-massive star binary at the time, which seemed unlikely."

Following an elongated orbit lasting about 25 years, the pulsar passes closest to its partner once each circuit. Whipping around its companion in early 2018, the pulsar will plunge through the surrounding disk and trigger astrophysical fireworks. It will serve as a probe to help astronomers measure the massive star's gravity, magnetic field, stellar wind and disk properties.

Several features combine to make this an exceptional binary. Out of six similar systems where the massive star uses hydrogen as its central energy source, J2032's has the greatest combined mass, the longest orbital period, and, at a distance of about 5,000 light-years, is closest to Earth.

"This forewarning of the energetic fireworks expected at closest approach in three years' time allows us to prepare to study the system across the entire electromagnetic spectrum with the largest telescopes," added Ben Stappers, a professor of astrophysics at the University of Manchester.

Astronomers think the supernova explosion that created the pulsar also kicked it into its eccentric orbit, nearly tearing the binary apart in the process. A study of the system led by Lyne and including Ray and Stappers was published June 16 in the journal Monthly Notices of the Royal Astronomical Society.



Contacts and sources:
Lynn Chandler
NASA's Goddard Space Flight Center

Dark Matter Map Begins to Reveal the Universe's Early History - Video


Researchers from the National Astronomical Observatory of Japan (NAOJ), the University of Tokyo and other institutions have begun a wide-area survey of the distribution of dark matter in the universe using Hyper Suprime-Cam, a new wide-field camera installed on the Subaru Telescope in Hawai'i.

A 14 arc minute by 9.5 arc minute section of a Hyper Suprime-Cam image, with contour lines showing the dark matter distribution.

Credit: NAOJ/HSC Project

Initial results from observations covering an area of 2.3 square degrees on the sky toward the constellation Cancer revealed nine large concentrations of dark matter, each the mass of a galaxy cluster. Surveying how dark matter is distributed and how the distribution changes over time is essential to understanding the role of dark energy that controls the expansion of the universe.

These first results demonstrate that astronomers now have the techniques and tools to understand dark energy. The next step is for the research team to expand the survey to cover a thousand square degrees on the sky, and thereby unravel the mystery of dark energy and the expansion of the universe.

Credit: Subaru Telescope NAOJe

Mapping dark matter over a wide region is key to understanding the properties of dark energy, which controls the expansion of the universe. These early results demonstrate that with current research techniques and Hyper Suprime-Cam, the team is now ready to explore how the distribution of dark matter in the universe has changed over time, unravel the mystery of dark energy, and explore the universe?s expansion history with great detail.

The data show a clear excess of dark matter concentrations over the current best theoretical model. Right: A schematic showing the dark matter concentrations discovered in the Hyper Suprime-Cam data. Left: A schematic showing predictions from current theoretical models.
Credit: NAOJ/HSC Project

Hyper Suprime-Cam lead developer, Dr. Satoshi Miyazaki, from the National Astronomical Observatory of Japan?s Advanced Technology Center and leader of the research team, praised the ability of the HSC for this work. "Now we know we have the both a technique and a tool for understanding dark energy. We are ready to use Hyper Suprime-Cam to create a 1000 square degree dark matter map that will reveal the expansion history of the universe with precise detail."

Using Weak Lensing by Dark Matter to Study Dark Energy's Effects:

Ever since 1929, when astronomer Edwin Hubble discovered that the universe is expanding, astronomers used a working model that had the rate of expansion slowing down over time. Gravitational attraction, until recently the only known force acting between galaxies, works against expansion. However, in the 1990s, studies of distant supernovae showed that the universe is expanding faster today than it was in the past. This discovery required a dramatic shift in our understanding of physics: either there?s some kind of "dark energy" with a repulsive force that forces galaxies apart, or the physics of gravity needs some fundamental revision (Note 1).

To unravel the mystery of the universe?s accelerating expansion, it is helpful to look at the relationship between the rate expansion of the universe and the rate at which astronomical objects form. For example, if the universe is expanding quickly, it will take longer for matter to coalesce and form galaxies. 

Conversely, if the universe is expanding slowly, it is easier for structures like galaxies to form. In effect, there?s a direct link between the history of structure formation in the universe, and the history of the universe's expansion. The challenge in confirming the existence of dark matter and its effect on expansion is that most of the matter in the universe is dark and does not emit light. It cannot be detected directly by telescopes, which are light-collecting machines.

One technique that can overcome this challenge is the detection and analysis of "weak lensing". A concentration of dark matter acts as a lens that bends light coming from even more distant objects. By analyzing how that background light is bent and how the lensing distorts the shapes of the background objects, it?s possible to determine how dark matter is distributed in the foreground. T

his analysis of dark matter and its effects lets astronomers determine how it has assembled over time. The assembly history of dark matter can be related to the expansion history of the universe, and should reveal some of the physical properties of dark energy, its strength and how it has changed over time.

To get a sufficient amount of data, astronomers need to observe galaxies more than a billion light-years away, across an area greater than a thousand square degrees (about one fortieth of the entire sky). The combination of the Subaru telescope, with its 8.2-meter diameter aperture, and Suprime-Cam, Hyper Suprime-Cam?s predecessor, with a field of view of a tenth of a square degree (comparable to the size of the Moon), has been one of the most successful tools in the search of faint distant objects over a wide area of sky.

However, even for this powerful combo, surveying a thousand degrees of sky at the necessary depth isn not realistic. "This is why we spent 10 years to develop Hyper Suprime-Cam, a camera with the same of better image quality as Suprime-Cam, but with a field of view over seven times larger," said Dr. Satoshi Miyazaki.

Hyper Suprime-Cam was installed on the Subaru Telescope in 2012. Following test observations, it was made available for open use by the astronomy community in March 2014. A "strategic" observing program, consisting of more than 300 nights of observing over five years is also underway. The camera, with 870 million pixels, delivers images that cover an area of sky as large as nine full moons in a single exposure, with extremely little distortion, at a fine resolution of seven thousandths of a degree (0.5 arc seconds).

Researchers from NAOJ, the University of Tokyo, and collaborators analyzed test data from Hyper Suprime-Cam?s commissioning to see how well it could map dark matter using the weak lensing technique. The data from a two-hour exposure covering 2.3 square degrees revealed crisp images of numerous galaxies. By measuring their individual shapes, the team created a map of the dark matter hiding in the foreground. 

The result was the discovery of nine clumps of dark matter, each weighing as much a galaxy cluster. The reliability of the weak lensing analysis, and the resulting dark matter maps, have been confirmed by observations with other telescopes that show actual galaxy clusters corresponding to the dark matter clumps discovered by Hyper Suprime-Cam. They utilized the archived Deep Lens Survey (PI: Tony Tyson, LSST Chief Scientist) data for the optical cluster identification.

The number of galaxy clusters by Hyper Suprime-Cam exceeds predictions from current models of the universe?s early history. As the research team expands the dark matter map to their goal of a thousand square degrees, the data should reveal whether this excess is real or just a statistical fluke. If the excess is real, it suggests that there wasn?t as much dark energy as expected in the past, which allows the universe to expand gently and stars and galaxies to form quickly.

Using weak lensing to map dark matter map is a way to discover astronomical objects using their mass, to learn that something exists and how much it weighs at the same time. It gives a direct measurement of mass that is typically unavailable when using other methods of discovery (Note 2). Therefore, mass maps of dark matter are an essential tool for understanding the expansion history of the universe precisely and accurately.

Notes:

1 The 2011 Nobel Prize in Physics was awarded "for the discovery of the accelerating expansion of the universe through observations of distant supernovae" with one half going to Saul Perlmutter (Lawrence Berkeley National Lab & the University of California, Berkeley) and the other half going jointly to Brian P. Schmidt (Australian National University) and Adam G. Riess (Johns Hopkins University & Space Science Institute).


2 Light, electromagnetic radiation of all wavelengths including, radio, visible light, and x-rays, is the standard search tool for astronomical objects. In general, there is no simple relationship between the amount of light an object emits and its mass. The distortion of light observed in weak lensing is a direct measure of mass, and is therefore a much more reliable tool for determining the distribution of mass in the universe.




Contacts and sources: 
Satoshi Miyazaki
National Astronomical Observatory of Japan

Saeko S. Hayashi,
Subaru Telescope, National Astronomical Observatory of Japan 


These are the first scientific results from Hyper Suprime-Cam and were accepted for publication in the July 1, 2015 edition of the Astrophysical Journal. (Miyazaki et al. 2015, ApJ 807, 22, "Properties of Weak Lensing Clusters Detected on Hyper Suprime-Cam 2.3 Square Degree Field".) This research has received Grants-in-Aid for Scientific Research (18072003 and 26800093) and World Premier International Research Center Initiative support through the Japanese Society for the Promotion of Science.

Macroscopic Brownian Motion Phenomena Of Self-Powered Liquid Metal Motors

Classical Brownian motion theory was established over one hundred year ago, describing the stochastic collision behaviors between surrounding molecules. Recently, researchers from Technical Institute of Physics and Chemistry, Chinese Academy of Sciences discovered that the self-powered liquid metal motors in millimeter scale demonstrated similar Brownian like motion behaviors in alkaline solution. And the force comes from the hydrogen gas stream generated at the interface between liquid metal motor and its contacting substrate bottom.

This is a vertical view of hydrogen bubble tails of liquid metal tiny motors. The scale bar is 1 cm
Credit:  ©Science China Press


Ever since the irregular motions of suspended grains in water was observed by Brown in 1827, tremendous efforts have been made on establishing a theory to characterize the Brownian motion. After almost a half century later, the kinetic theories of heat developed by Maxwell, Boltzmann and others were merging as a possible explanation. 

In 1905, Einstein published a theoretical paper interpreting the stochastic process using particle diffusion constant and the fluid viscosity. This relationship bridges the microscopic dynamics with the macroscopic phenomenon, which inspired many subsequent works regarding both thermodynamics and statistical physics. Such theory was later demonstrated by the well-known Perrin's experiments. 

This video shows hydrogen bubble tails generated from a swarm of self-powered liquid metal tiny motors which were distinguished through high contrast optical images. It indicates that these tiny motors kept swiftly traveling here and there, just like a fairy.

Credit: ©Science China Press

So far, most of the classical Brownian motions refer to the molecules activities that occur in microscale. There are very limited reports to investigate such phenomena in macroscale. And the ever tackled phenomena are mainly focused on the particle motions caused by the surrounding liquid molecules.

In this study, researchers disclosed that macroscopic liquid metal motors in millimeter scale showed similar Brownian motion behavior in alkaline solution. The authors dispersed the premixed liquid metal and Al (mass percentage 1%) alloy into a glass Petri dish. It was observed that each tiny motor in millimeter scale began to move swiftly and randomly on Petri dish glass. 

The driving mechanisms of Brownian liquid metal tiny motor and its hydrogen generation mechanism are shown.
Credit: ©Science China Press


Contrary to the classical Brownian motion behavior, the main driving force of such motion comes from the hydrogen bubbles generated at the bottom of the tiny motors. Such tiny motor differs in moving mechanism with its counterpart large size self-fueled liquid metal machine which was mainly driven by the electrochemically induced surface tension. Further, an optical platform with high image contrast, which works somewhat like the Wilson Cloud Chamber, was introduced to clearly depict the hydrogen bubble stream left behind the running motors.

The present findings add important new knowledge to the liquid metal motor as well as the classical Brownian motion phenomenon. The established optical image contrast method also provides an important experimental tool for further investigations along this direction.




Contacts and sources:
Science China Press

This research was partially supported by the Research Funding of the Chinese Academy of Sciences (No. KGZD-EW-T04-4).

Citation: B. Yuan, S. Tan, Y. Zhou, J. Liu, "Self-powered macroscopic Brownian motion of spontaneously running liquid metal motors," Sci. Bull. (2015) 60(13):1203-1210. http://link.springer.com/article/10.1007%2Fs11434-015-0836-6


Seahorse Tails Could Inspire New Generation of Robots

Inspiration for the next big technological breakthrough in robotics, defense systems and biomedicine could come from a seahorse's tail, according to a new study reported July 2 in the journal Science.

The researchers designed this 3-D-printed model based on the design of a seahorse tail.
Credit: Clemson University

The research centers on the curious shape of seahorse tails and was led by Clemson University's Michael M. Porter, an assistant professor of mechanical engineering.

Seahorse tails are organized into square prisms surrounded by bony plates that are connected by joints. Many other creatures, ranging from New World monkeys to rodents, have cylindrical tails.


Credit: Clemson University

Researchers wanted to know whether the square-prism shape gives seahorse tails a functional advantage.

To find out, the team created a 3D-printed model that mimicked the square prism of a seahorse tail and a hypothetical version that was cylindrical. Then researchers whacked the models with a rubber mallet and twisted and bent them.

Researchers found that the square prototype was stiffer, stronger and more resilient than the circular one when crushed. The square prototype was about half as able to twist, a restriction that could prevent damage to the seahorse and give it better control when it grabs things.

Both prototypes could bend about 90 degrees, although the cylindrical version was slightly less restricted.

Porter said the seahorse tail could inspire new forms of armor. It could also lead to search-and-rescue robots that move on the ground like a snake and are able to contract to fit into tight spaces.

"We haven't gotten that far with the applications side of things yet, but we see a lot of potential with this device because it's so unique," Porter said.


Credit: Clemson University

The study's co-authors are Dominique Adriaens of Ghent University in Belgium; Ross L. Hatton of Oregon State University; and Marc A. Meyers and Joanna McKittrick, both of the University of California, San Diego.

Porter said that he built the models and gathered data while he was Ph.D. student at UC San Diego. He graduated in June 2014 and began work at Clemson the following August. He did all the analysis and writing for the study at Clemson.

For Porter, the next step is to build a robot using what he's learned about seahorse tails. He is in the early stages of research with two Clemson professors: Ian Walker, a professor in the Holcombe Department of Electrical Engineering and Computer Science, and Richard Blob, a biological sciences professor.

"Part of the reason I came to Clemson was this research," Porter said.

Anand Gramopadhye, dean of the College of Engineering and Science, said the study shows that Clemson is attracting some of the nation's top talent.

"Science is a premiere academic journal that is highly selective about what it publishes," he said. "The article shows the exemplary level of scholarship that Dr. Porter brings to Clemson University. I congratulate him and his team."

Science is the world's largest peer-reviewed general science journal.

For years, engineers have been taking inspiration from nature to design new technologies. The Porter-led study did that, but took things a step further. Researchers used engineering to learn more about nature.

New technologies, such as 3D printing, allow researchers "to build idealized models of natural systems to better understand their different functions," Porter said.

"This study demonstrates that engineering designs are convenient means to answer elusive biological questions when biological data are nonexistent or difficult to obtain," researchers wrote in the article. "In addition, understanding the role of mechanics in these biologically inspired designs may help engineers to develop seahorse-inspired technologies for a variety of applications in robotics, defense systems, or biomedicine."

Congratulations also came Melur K. Ramasubramanian, chair of the mechanical engineering department.

"Dr. Porter has begun to have a big impact even though he has been at Clemson for a short time," Ramasubramanian said. "We're thrilled to have him in the department of mechanical engineering."



Contacts and sources:
Michael Porter

Wednesday, July 1, 2015

Discovery Buried in the Heart of a Giant

Discovered from England by the tireless observer Sir William Herschel on 20 November 1784, the bright star cluster NGC 2367 lies about 7000 light-years from Earth in the constellation Canis Major. Having only existed for about five million years, most of its stars are young and hot and shine with an intense blue light. This contrasts wonderfully in this new image with the silky-red glow from the surrounding hydrogen gas.

This rich view of an array of colorful stars and gas was captured by the Wide Field Imager (WFI) camera, on the MPG/ESO 2.2-meter telescope at ESO's La Silla Observatory in Chile. It shows a young open cluster of stars known as NGC 2367, an infant stellar grouping that lies at the center of an immense and ancient structure on the margins of the Milky Way.

Credit: ESO/G. Beccari

Open clusters like NGC 2367 are a common sight in spiral galaxies like the Milky Way, and tend to form in their host's outer regions. On their travels about the galactic centre, they are affected by the gravity of other clusters, as well as by large clouds of gas that they pass close to. Because open clusters are only loosely bound by gravity to begin with, and because they constantly lose mass as some of their gas is pushed away by the radiation of the young hot stars, these disturbances occur often enough to cause the stars to wander off from their siblings, just as the Sun is believed to have done many years ago. An open cluster is generally expected to survive for a few hundred million years before it is completely dispersed.

This video starts with a view of the southern Milky Way and takes us on a journey towards the open star cluster NGC 2367, not far from the bright star Sirius in the constellation of Canis Major (The Greater Dog). The MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile captured this richly colourful view. The brighter cluster stars are very young by stellar standards and still shine with a hot bluish colour.
Credit: ESO/G. Beccari/Digitized Sky Survey 2/N. Risinger (skysurvey.org). Music: Johan B. Monell (www.johanmonell.com)

In the meantime, clusters serve as excellent case studies for stellar evolution. All the constituent stars are born at roughly the same time from the same cloud of material, meaning they can be compared alongside one another with greater ease, allowing their ages to be readily determined and their evolution mapped.

Like many open clusters, NGC 2367 is embedded within an emission nebula), from which its stars were born. The remains show up as wisps and clouds of hydrogen gas, ionised by the ultraviolet radiation being emitted by the hottest stars. What is more unusual is that, as you begin to pan out from the cluster and its nebula, a far more expansive structure is revealed: NGC 2367 and the nebula containing it are thought to be the nucleus of a larger nebula, known as Brand 16, which in turn is only a small part of a huge supershell, known as GS234-02.

This chart shows the constellation of Canis Major (The Greater Dog). Most of the stars visible to the naked eye on a clear night are shown. The location of the bright open cluster, NGC 2367, which can well seen in a small telescope, is marked with a red circle.

Credit:  ESO/IAU and Sky & Telescope


The GS234-02 supershell lies towards the outskirts of our galaxy, the Milky Way. It is a vast structure, spanning hundreds of light-years. It began its life when a group of particularly massive stars, producing strong stellar winds, created individual expanding bubbles of hot gas. 

This pan video gives a close-up view of an array of colourful stars and gas that was captured by the Wide Field Imager (WFI) camera, on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. It shows a young open cluster of stars known as NGC 2367, an infant stellar grouping that lies at the centre of an immense and ancient structure on the margins of the Milky Way.
Credit: ESO/G. Beccari. Music: Johan B. Monell (www.johanmonell.com)

These neighbouring bubbles eventually merged to form a superbubble, and the short life spans of the stars at its heart meant that they exploded as supernovae at similar times, expanding the superbubble even further, to the point that it merged with other superbubbles, which is when the supershell was formed. The resulting formation ranks as one of the largest possible structures within a galaxy.

This concentrically expanding system, as ancient as it is enormous, provides a wonderful example of the intricate, interrelated structures that are sculpted in galaxies by the lives and deaths of stars.


Contacts and sources:
Richard Hook
ESO

Males May Contribute To Offspring's Mental Development Before Pregnancy Says Study


A new study from Indiana University provides evidence in mice that males may play a positive role in the development of offspring's brains starting before pregnancy.

The research, reported June 30 in the Proceedings of the Royal Society of London B: Biological Sciences, found that female mice exposed to male pheromones gave birth to infants with greater mental ability.

The offspring of mother mice exposed to male pheromones before pregnancy displayed greater intelligence compared to other mice.

Credit: Indiana University

"This is the first study to show that pheromone exposure exerts an influence across generations in mammals," said Sachiko Koyama, an associate research scientist at the IU Bloomington Medical Sciences Program and visiting scientist at the IU College of Arts and Sciences' Department of Psychological and Brain Sciences, who led the study.

"We found that male pheromones seem to influence the nutritional environment following birth, resulting in changes to the brain that could extend to future generations," she added.

Pheromones are chemical signals used to communicate between organisms of the same species. The connection between male pheromones and offspring's brain development seems to stem from the influence of male pheromones on the nursing ability of mother mice.

Specifically, IU scientists measured greater mammary gland development in mice exposed to male pheromones a week after exposure, which may have led to greater volumes or improved quality of milk production. These mother mice also showed lengthier nursing periods compared to mice not exposed to the male pheromone.

To measure the intelligence of the offspring, IU scientists placed mice in a water maze with a hidden platform. The mice born of mothers exposed to male pheromones learned the location of the hidden platform much faster, suggesting quicker learning and stronger spatial memory compared to the control group.

These improvements in brain development and cognitive function may stem from specific "neuro-enhancing" chemicals in breast milk, such as sialic acid, a component of breast milk also found at high levels in the brain during early development. IU researchers found higher levels of polysialyltransferase -- an enzyme that requires sialic acid to produce a molecule involved in neural cell development -- in the brains of the offspring of female mice exposed to male pheromones compared to the control group.

A synthetic version of the male mouse pheromone 2-sec-butyl-4,5-dihydrothiazole, or "SBT," was used in the study. The chemical was discovered at the Institute for Pheromone Research in the IU Department of Chemistry, directed by Milos Novotny, Distinguished Professor Emeritus of Chemistry and Lilly Chemistry Alumni Chair in the IU Bloomington College of Arts and Sciences. Novotny's lab pioneered research on pheromones in mammals during the 1980s at IU, identifying the chemical structures and determining the biological effects of these pheromones in mice, and later in several other mammalian species. Previously, scientists regarded pheromones as limited to the world of insects.

"This publication represents an important addition to the field of animal communication and the effects of mammalian pheromones," said Novotny. "It shows that the effect of the male mouse pheromone SBT not only transmits an important olfactory message to the recipient females, but, through some as yet unknown molecular signaling mechanisms, brings apparent benefits to their offspring."

Previous pheromone research has primarily focused on the influence of chemicals on animals within the same generational group, such as on mating behaviors, including the ability to suppress or encourage mammalian mating activity, as well as to attract females or stimulate aggression in males.

The power of scents has also been shown in humans through research showing women who spend a long time together synchronize menstrual cycles.

By focusing on pheromone effects across generations, Koyama said the new IU study contributes to the growing field of epigenetics, which studies the influence of the environment on genetics, such as when nutrition creates changes in the body which may be passed on to the next generation.

"If we can find the specific milk 'ingredients' that affect cognitive function in the offspring, for example, we may eventually be able to use them as supplements to enhance brain development," she said.

For their next steps, the IU team plans to conduct a more complete chemical analysis of the milk of the mother mice, as well as to track the mental development of their offspring across future generations.



Contacts and sources:
Kevin FrylingIndiana University

Spectacular Discovery of How Memories Form and Learning Takes Place

Jennifer Aniston, Clint Eastwood and Halle Berry images used in 'mind game' to establish for the first time how new memories are formed.

The study reveals that the same brain neuron that fires for one image (Jennifer Aniston) would also fire instantly for another image (Eiffel Tower) if the volunteer had been shown an image of Jennifer Aniston at the Eiffel Tower

This remarkable result shows that the neurons changed their firing properties at the exact moment the subjects formed the new memories

It demonstrates that the neuron encodes the memory of the person as well as the place if they are both shown together. Therefore a memory has been formed of that person at that place 'The discovery that individual neurons in the Medial Temporal Lobe, the brain's main engine for memory formation, changed their firing to encode new associations even after one single presentation provides a plausible mechanism underlying the creation of new memories. The study suggests that the experience of learning can be traced back to changes in individual neurons in the brain.'

Brain scientists in the UK and US have collaborated to make 'a spectacular discovery' - for the first time in human studies - of how memories are formed and new learning takes place.

A collaboration between Dr Matias Ison and Professor Rodrigo Quian Quiroga at the University of Leicester and Dr Itzhak Fried at Ronald Reagan UCLA Medical Center revealed how a neuron in the brain instantly fired differently when a new memory was formed.

This is Clint Eastwood in front of the Leaning Tower of Pisa.
Credit: University of Leicester

The research group at Leicester and UCLA had previously announced the 'Jennifer Aniston neuron' -the firing of a single neuron for a single image to form a concept. The team has now proved their hypothesis to be true- and has gone further to demonstrate how new memories are formed.

The Jennifer Aniston Neuron & Forming Memories
Credit: University Leicester

The scientists showed patients images of a person in a context e.g. Jennifer Aniston at the Eiffel Tower, Clint Eastwood in front of the Leaning Tower of Pisa, Halle Berry at the Sidney Opera House or Tiger Woods at the White House. They found that the neuron that formerly fired for a single image e.g. Jennifer Aniston or Halle Berry, now also fired for the associated image too i.e. the Eiffel Tower or Sidney Opera House.

"The remarkable result was that the neurons changed their firing properties at the exact moment the subjects formed the new memories - the neuron initially firing to Jennifer Aniston started firing to the Eiffel Tower at the time the subject started remembering this association," said Rodrigo Quian Quiroga, head of the Centre for Systems Neuroscience at the University of Leicester.

"Moreover, we observed these changes after just a single presentation. This is a radical departure from previous experiments in animals where changes have been observed mainly after long training sessions. This is critical to understanding the neural processes underlying real-life memory formation, as in real life we are not repeatedly exposed to an event in order to remember it - just one exposure is enough."

The researchers from the University of Leicester and Ronald Reagan UCLA Medical Center have published their research in the peer-reviewed leading journal Neuron. The research was supported by grants from the National Institute of Neurological Disorders and Stroke (NINDS) of the National Institutes of Health (NIH), Medical Research Council (MRC), the Human Frontiers Science Program and the Mathers Foundation.

Lead author Matias Ison, Lecturer in Bioengineering in the Department of Engineering, University of Leicester, said: "This is the first study to look at how a single neuron correlates learning of new contextual associations in the human brain. The single neuron underpinning of memory formation has previously been addressed only by animal studies, which can only offer a limited account of how single events can lead to new episodic memories."

"We previously found that individual neurons in the human brain respond selectively to concepts that are related to each other, such as two co-stars in the same television series (e.g. Jennifer Aniston and Lisa Kudrow, Rachel and Phoebe in the TV series 'Friends'.) In this study, we wanted to combine the high selectivity of human Medial Temporal Lobe (MTL) neurons with the exquisite speed and easiness at which humans can learn complex associations and consciously declare them. For this, we created a memory game that allowed us to "incept" new associations into the subject's brain."

"Given the involvement of MTL neurons in memory formation, we hypothesised that we would be able to see some changes in the firing of the neurons. But the astonishing fact was that these changes were dramatic, in the sense of neurons changed from being very silent to firing a lot, and that these changes occurred at the exact moment of learning, even after one trial. The emergence of association of concepts established after single trials, linked to rapid neural activity changes, turned out to be ideal for the creation of new episodic memories."

"Episodic memories, like running into an old school friend at the cinema, are unique experiences that rely on the very rapid formation of associations, said Dr Ison. During our research, we had the rare opportunity to work with neurosurgical patients at UCLA Medical Center. Collaborating with an interdisciplinary team of researchers from the University of Leicester and Ronald Reagan UCLA Medical Center, we were able to record from individual neurons in the Medial Temporal Lobe (MTL), the brain's main engine of episodic memory formation."

"We monitored the activity of individual neurons in the human brain while presenting patients with pairs of unrelated pictures in a laptop i.e. people and places. The pictures would show, for instance, a picture of Clint Eastwood with the famous Leaning Tower of Pisa at the back. We basically found that neurons rapidly changed their firing patterns to encode new associations. In this way, a cell that was responsive to only one picture before learning (say Clint Eastwood), later started firing to an associated picture (the famous Italian Tower), while remaining silent to other pictures. But the striking fact was that these firing changes occurred at the exact moment of learning and sometimes even after one single presentation. These results tell us something important about how groups of neurons in the brain encode related concepts to store new memories."

Dr Ison said understanding the underpinnings of episodic formation is a central problem in neuroscience because of how important memory is for our everyday life. Moreover, this type of memory is affected in patients suffering from certain neurological disorders.

The discovery that individual neurons in the Medial Temporal Lobe, the brain's main engine for memory formation, changed their firing to encode new associations even after one single presentation provides a plausible mechanism underlying the creation of new memories. The study suggests that the experience of learning can be traced back to changes in individual neurons in the brain.

Dr Ison said: "A better understanding of how assemblies of neurons represent learning and memory might lead to novel ideas about our memory capacities and how these might deteriorate in patients suffering from certain neurological disorders."

The work is the result of a five year study carried out in collaboration between University of Leicester and Ronald Reagan UCLA Medical Center. Dr Ison said: "I have had the opportunity to work with an amazing group of patients who volunteered to participate in our study. It was very compelling to work with them. I feel very grateful."

"Almost a decade ago, when I obtained a PhD in Statistical Physics from the University of Buenos Aires in Argentina, I decided to join Quian Quiroga's team at the University of Leicester to work on Neuroscience. Back then it was hard to imagine that I was going to be able to contribute to the understanding of how the brain works at such vital level. It really feels like a major achievement."

Contacts and sources:
Matias Ison
University of Leicester